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  • 1
    Digitale Medien
    Digitale Medien
    Buchbesprechungen (1988)
    Springer
    OR spectrum 10 (1988), S. 28-28 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720031
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Maximum-Likelihood-Schätzung aus gruppierten Daten — eine Übersicht (1988)
    Springer
    OR spectrum 10 (1988), S. 1-12 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Summary Often statistical data are available only in grouped form. In this paper we give a survey on estimation of parameters from grouped data using the Maximum-Likelihood-Method. First some notation is introduced and it is shown how the loss of information due to grouping may be quantified. The stochastic properties of Maximum-Likelihood-Estimates and various methods for their computation are discussed. Finally some empirical examples are given.
    Notizen: Zusammenfassung Statistische Daten sind oft nur in gruppierter Form verfügbar. In dieser Arbeit wird ein Überblick über die Maximum-Likelihood-Methode zur Parameterschätzung aus gruppierten Daten gegeben. Nach Einführung der Notation wird gezeigt, wie der Informationsverlust, der durch die Gruppierung entsteht, quantifiziert werden kann. Die stochastischen Eigenschaften der Maximum-Likelihood-Schätzer werden behandelt. Ausführlich wird auf verschiedene Methoden zur Berechnung der Maximum-Likelihood-Schätzwerte eingegangen. Einige empirische Beispiele schließen die Arbeit ab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720028
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  • 3
    Digitale Medien
    Digitale Medien
    Discount-isotone policies for Markov decision processes (1988)
    Springer
    OR spectrum 10 (1988), S. 13-22 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Für unendlich-stufige diskontierte Markovsche Entscheidungsprozesse werden Bedingungen angegeben, unter denen sogenannte “diskont-isotone” optimale Politiken existieren. Eine diskont-isotone Familie von optimalen Politiken liegt vor, wenn die Zustands- und Aktionenräume halbgeordnet sind und für eine Menge von Diskontierungsfaktoren je eine optimale Politik existiert, so daß in jedem Zustand die optimalen Aktionen isoton vom Diskontierungsfaktor abhängen. Es kann günstiger sein, zunächst Probleme mit kleinem Diskontierungsfaktor zu lösen und dann die Isotonie-Eigenschaften zur Lösung für größere Diskontierungsfaktoren heranzuziehen.
    Notizen: Summary This paper considers infinite horizon discounted Markov decision processes and conditions under which discount-isotone optimal policies exist. Given partial orders over the state and action spaces, a set of discount-isotone optimal policies is a set of optimal policies, one for each discount factor in a given set, such that, for each state, the optimal actions are partially ordered in such a manner as to match the ordering of the discount factors. It is easier to solve problems with small discount factors and the induced partial ordering facilitates the solutions for higher discount factor levels.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720029
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Buchbesprechungen (1988)
    Springer
    OR spectrum 10 (1988), S. 36-36 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720033
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Probabilistic analysis of a continuous review perishable inventory system with Markovian demand, Erlangian life and non-instantaneous lead time (1988)
    Springer
    OR spectrum 10 (1988), S. 23-27 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Der vorliegende Artikel behandelt einen expliziten Kostenausdruck für eine stetige Überprüfung der (S, s) Bestellpolitik eines Lagerhaltungssystems verderblicher Güter im stationären Fall. Der Kostenausdruck ist eng verbunden mit der stationären Verteilung des stochastischen ProzessesL(t), der den Lagerbestand zu jeder beliebigen Zeitt darstellt. Das stochastische Verhalten des Prozesses {L(t),t≳-0} wird characterisiert durch die Identifikation eines eingebetteten MRP. Die Nachfragewerte des Systems werden durch einen Poisson-Prozeß bestimmt. Die gelagerten Güter haben eine nutzbare Lebensdauer, die durch eine Erlang-Verteilung beschrieben wird. Die Durchlaufzeit ist eine Zufallsvariable mit spezifierter Wahrscheinlichkeitsverteilung. Es wird zudem unterstellt, daß nicht befriedigte Nachfrage bei leerem Lager verloren geht.
    Notizen: Summary This article obtains an explicit cost expression for a continuous review (S, s) ordering policy inventory system of perishable items, in the stationary case. The cost expression is closely related to the stationary distribution of the stochastic processL(t), representing the inventory at any timet. The stochastic behaviour of the process {L(t),t≳-0} is characterised by identifying an imbedded MRP. The demands of the system are governed by a Poisson process. The items in the inventory have a useful life time characterised by an Erlangian distribution. The lead time is a random variable with specified probability distribution. It is assumed that the demands that arrive when the inventory is zero are lost.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720030
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Enumerative techniques for solving some nonconvex global optimization problems (1988)
    Springer
    OR spectrum 10 (1988), S. 29-35 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Wir geben einen Überblick über verschiedene Methoden für nicht konvexe Minimisierungsaufgaben. Insbesondere diskutieren wir Aufzählungsmethoden für Extrempunkte. Wir betrachten konkave, quadratisch indefinite Probleme ebenso wie Probleme spezieller Struktur: konkave Netzwerk-Fluß-Probleme und lineare Komplementaritäts-Probleme. Wir schlagen neue Methoden vor, um lineare untere Schranken für Aufzählungstechnicken zu erhalten.
    Notizen: Summary We give an overview on different methods for solving nonconvex minimization problems using techniques of enumeration of extreme points. The problems considered include concave, indefinite quadratic, and special structured problems such as the concave cost network flow problem and linear complementarity. For methods that enumerate the extreme points according to the ascending order of the value of a linear underestimating function we propose new techniques for obtaining such underestimators.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720032
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  • 7
    Digitale Medien
    Digitale Medien
    Zur Besprechung eingegangene Bücher (1988)
    Springer
    OR spectrum 10 (1988), S. 54-54 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720036
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    Buchbesprechungen (1988)
    Springer
    OR spectrum 10 (1988), S. 54-54 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720037
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    Digitale Medien
    Digitale Medien
    Optimization of unloading strategy for bulk carriers (1988)
    Springer
    OR spectrum 10 (1988), S. 45-53 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Ein mathematisches Modell zur Berechnung der Entladezeit und Optimierung der Entlade-Strategie für mit Schüttgut beladene Schiffe ist zu entwickeln. Als erster Schritt wird in diesem Artikel der Entladevorgang einer einzigen Luke (Schiffs-Ladekammer) analysiert und durch ein mathematisches Modell beschrieben. Das Modell ermöglicht es dem Anwender, die Entladezeit einer Luke für beliebige Entlade-Dispositionen rechnerisch zu bestimmen und somit verschiedene Dispoitionen miteinander zu vergleichen.
    Notizen: Summary A mathematical model for computation of unloading time and optimization of unloading strategy for ships transporting bulk goods is searched for. As the first step the unloading process of a single hatch (ship's freight room) is analysed and described by a mathematical model in this paper. The model essentially enables one to compute the unloading time of a hatch for any given unloading procedure and thus to compare and value different competing procedures.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720035
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    How long will fast food customers wait? (1988)
    Springer
    OR spectrum 10 (1988), S. 37-44 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Der Zusammenhang zwischen den grundlegenden Bedienungscharakteristiken eines Schnellimbißkiosks und dem Verhalten seiner Kunden wird anhand eines Modells untersucht, welches den Lernprozeß der wartenden Kunden in bezug auf die Bedienungszeit in Rechnung stellt. Das Modell ist auf zwei Fälle ausgelegt. Im ersten Fall wird ein Kiosk in einem Einkaufskomplex betrachtet, dessen Kunden unsicher über die Bedienrate sind. Der zweite Fall behandelt einen Kiosk in einem Bürokomplex, wobei die Kunden Vorinformationen über die Bedienrate besitzen. Simulationsexperimente mit dem Modell offenbaren, wie die Unterschiede zwischen der erwarteten (oder versprochenen) und der beobachteten (oder geleisteten) Bediengeschwindigkeit und -qualität den Verlust von Kundschaft verursachen, bei zwei hypothetischen sowie zwei realen Schnellimbissen.
    Notizen: Summary The relationship between a fast-food kiosk's basic operating characteristics and its customers' behavior is examined using a model which takes into account the learning process of the waiting customers with respect to the service time. The model is adapted to two cases. In the first case, a kiosk in a shopping complex is considered, whose customers are uncertain about the service rate. The second case deals with a kiosk in an office complex and its customers have prior information about the service rate. Simulation experiments with the model reveal how the discrepancies between the expected (or promised) and perceived (or delivered) service speed and quality cause lost patronage at two hypothetical and two real world fast-food operations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720034
    Standort Signatur Erwartet Verfügbarkeit
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  • 11
    Digitale Medien
    Digitale Medien
    DGOR-Jahrestagung 1988 (1988)
    Springer
    OR spectrum 10 (1988), S. 64-64 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720039
    Standort Signatur Erwartet Verfügbarkeit
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  • 12
    Digitale Medien
    Digitale Medien
    Zur Besprechung eingegangene Bücher (1988)
    Springer
    OR spectrum 10 (1988), S. 185-185 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01740514
    Standort Signatur Erwartet Verfügbarkeit
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  • 13
    Digitale Medien
    Digitale Medien
    Optimale Innovationspolitik bei unvollständiger Information (1988)
    Springer
    OR spectrum 10 (1988), S. 173-183 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Summary The innovation problem of a single firm is described as a sequential decision problem under uncertainty. In each period the firm can improve its technology by R&D activities. It is shown that a “reservation technology” exists — the firm stops its efforts in R&D before reaching the technological limit. The reservation technology can be influenced by competition or basic research. Moreover, new insights into the innovation advantages of big corporations are given.
    Notizen: Zusammenfassung Das Innovationsproblem einer Firma wird im Rahmen eines sequentiellen Entscheidungsproblems bei Unsicherheit behandelt. Dabei kann die Firma unter Aufwendung von F&E-Ausgaben in jeder Periode ihr bisheriges Technologieniveau/ihre bisherige Produktqualität verbessern. Unter plausiblen Annahmen kann gezeigt werden, daß ein „Reservationstechnologieniveau“ existiert, ab dem es für eine Firma nicht mehr lohnend ist, F&E zu betreiben. Innovationskonkurrenz bzw. Grundlagenforschung können diese kritische Grenze positiv beeinflussen. Ein neues, interessantes Ergebnis über den Zusammenhang zwischen Firmengröße und Innovationsaktivität wird demonstriert.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01740512
    Standort Signatur Erwartet Verfügbarkeit
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  • 14
    Digitale Medien
    Digitale Medien
    Buchbesprechungen (1988)
    Springer
    OR spectrum 10 (1988), S. 186-194 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01740515
    Standort Signatur Erwartet Verfügbarkeit
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  • 15
    Digitale Medien
    Digitale Medien
    Solution of placement and routing problems in telephone exchange unit designs (1988)
    Springer
    OR spectrum 10 (1988), S. 213-220 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Eines der Probleme, die beim Gestaltungsprozeß elektromechanischer Vermittlungseinheiten auftreten, besteht darin, viele untereinander verbundene Objekte auf Positionen anzuordnen, die eine gegebene Struktur bilden. In diesem Papier wird beschrieben, wie dieses Problem mit Plazierungs- und Reihenfolgeheuristiken gelöst werden kann. Das reale Problem wird kurz angesprochen und die Optimierungs-probleme werden formal dargestellt. Zwei verschiedene Ansätze für ihre Lösung werden vorgestellt und unter Berücksichtigung ihres Rechenaufwands diskutiert. Zusätzlich werden einige erläuternde Beispiele von verbesserten Gestaltungen gegeben.
    Notizen: Summary One problem in the design of electromechanical exchange units consists in arranging a large number of interconnected objects in positions forming a given structure. We describe in the present paper how this problem can be solved with placement and routing heuristics. The real-life problem is briefly reported and the optimization problems are stated formally. Two different approaches to their solution are presented and discussed with reference to the computational effort required for each. Some illustrative examples of improved designs are also given.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720248
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  • 16
    Digitale Medien
    Digitale Medien
    Strategische Planung horizontal und vertikal differenzierter Gesundheitsprogramme (1988)
    Springer
    OR spectrum 10 (1988), S. 221-235 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Summary We consider a health programme from a policy perspective. This programme is specified for certain subgroups of a population, which can be treated in varying intensities. Its effectiveness depends on resources spent. We take into account that several resource categories may exist. The group-specific subproblems are modelled as stochastic decision chains with continuous action space, piecewise linear, monotone, convex cost functions and finite horizon. This paper develops a LP-model for efficient, simultaneous resource allocation.
    Notizen: Zusammenfassung Im Rahmen strategischer Überlegungen kann ein Gesundheitsprogramm für verschiedene Untergruppen einer Population jeweils spezifisch ausgelegt und unterschiedlich intensiv betrieben werden. Programmintensität und -Wirksamkeit hängen vom Ressourceneinsatz ab. Hier werden mehrere Ressourcenkategorien zugelassen, und die untergruppenspezifischen Teilprogramme werden als stochastische Entscheidungsketten mit stetigem Aktionsraum, stückweise linearen, monotonen, konvexen Kostenfunktionen und endlichem Horizont modelliert. Wir entwickeln ein LP-Modell, das die effiziente Simultanallokation der Ressourcen zum Ziel hat.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720249
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  • 17
    Digitale Medien
    Digitale Medien
    Buchbesprechungen (1988)
    Springer
    OR spectrum 10 (1988), S. 236-236 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720250
    Standort Signatur Erwartet Verfügbarkeit
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  • 18
    Digitale Medien
    Digitale Medien
    Regent developments in time series forecasting (1988)
    Springer
    OR spectrum 10 (1988), S. 195-212 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung „Extrapolative“ Zeitreihenprognoseverfahren sind in der betriebswirtschaftlichen Praxis weit verbreitet. Ihre große praktische Bedeutung hat nicht nur zur Entwicklung neuer Prognoseverfahren geführt, sondern auch zu vergleichenden Untersuchungen und Beurteilungen etablierter Methoden. Dieser Beitrag stellt eine Übersicht der wichtigsten „extrapolativen“ Prognoseverfahren dar. Darüberhinaus befaßt er sich mit neueren Untersuchungen zur relativen Genauigkeit dieser Verfahren und unterstreicht die teilweise unerwarteten Schlußfolgerungen dieser neuen Untersuchungen. Unternehmen sind daran interessiert, daß für sie am besten geeignete Prognoseverfahren zu wählen. Der Beitrag erörtert die Art des Wahlprozesses und bespricht die Frage, inwieweit Zeitreihenmethoden betriebswirtschaftliche Urteile ergänzen können. Zum Schluß befaßt sich der Beitrag kurz mit Prognoseverfahren Software und äußert eine persönliche Meinung über Zeitreihenprognoseverfahren.
    Notizen: Summary Time series (extrapolative) forecasting procedures are widely used in business. Their importance has led to the development of new methods of forecasting and research into the evaluation of well-established methods. This paper presents an overview of the major methods of extrapolative forecasting. Secondly it considers the evidence on the relative accuracy of these methods, highlighting the unexpected conclusions arrived at by this new research. Organizations need to identify the forecasting method most appropriate to their particular circumstances. The paper discusses how such a selection should take place, commenting on how time series methods can complement managerial judgement. The paper concludes with some brief remarks on forecasting software, and a personal view of the future of time series forecasting.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720247
    Standort Signatur Erwartet Verfügbarkeit
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  • 19
    Digitale Medien
    Digitale Medien
    Buchbesprechungen (1988)
    Springer
    OR spectrum 10 (1988), S. 248-248 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720252
    Standort Signatur Erwartet Verfügbarkeit
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  • 20
    Digitale Medien
    Digitale Medien
    Call for papers (1988)
    Springer
    OR spectrum 10 (1988), S. 249-249 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720253
    Standort Signatur Erwartet Verfügbarkeit
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  • 21
    Digitale Medien
    Digitale Medien
    Dank den referenten (1988)
    Springer
    OR spectrum 10 (1988), S. 250-250 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720254
    Standort Signatur Erwartet Verfügbarkeit
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  • 22
    Digitale Medien
    Digitale Medien
    Empirische Erhebung über Verschnittsoftware (1988)
    Springer
    OR spectrum 10 (1988), S. 237-247 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Summary In order to make the German market for software on cutting stock problems more transparent suppliers of computer programs are assembled and asked on the basis of a detailed catalogue of criteria developed before. The paper documents this empirical investigation and presents the results for 28 programs of 14 different firms.
    Notizen: Zusammenfassung Um auf dem unübersichtlichen Softwaremarkt das Angebot an Standardsoftware zur DV-mäßigen Unterstützung und Optimierung industrieller Zuschneideprozesse transparenter zu gestalten, wurden Anbieter entsprechender Programme erhoben und auf der Basis eines zuvor entwickelten Kriterienkatalogs befragt. Der Beitrag dokumentiert diese empirische Untersuchung und stellt als Ergebnis 28 Programme von 14 verschiedenen Anbietern vergleichend gegenüber.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720251
    Standort Signatur Erwartet Verfügbarkeit
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  • 23
    Digitale Medien
    Digitale Medien
    Tagungen (1988)
    Springer
    OR spectrum 10 (1988), S. 251-252 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720255
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  • 24
    Digitale Medien
    Digitale Medien
    Zur Besprechung eingegangene Bücher (1988)
    Springer
    OR spectrum 10 (1988), S. 252-252 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720256
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  • 25
    Digitale Medien
    Digitale Medien
    Buchbesprechungen (1988)
    Springer
    OR spectrum 10 (1988), S. 253-254 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720257
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  • 26
    Digitale Medien
    Digitale Medien
    Tagungen (1988)
    Springer
    OR spectrum 10 (1988), S. 65-66 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720040
    Standort Signatur Erwartet Verfügbarkeit
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  • 27
    Digitale Medien
    Digitale Medien
    LPL: A structured language for linear programming modeling (1988)
    Springer
    OR spectrum 10 (1988), S. 55-63 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Dieser Artikel beschreibt eine spezialisierte Programmiersprache LPL (Linear Programming Language), die sich dazu eignet, LP-Modelle aufzubauen, zu modifizieren und dokumentieren. Die LPL-Sprache wurde zum Erstellen von MPSX-Input-Dateien größerer Modelle erfolgreich eingesetzt. Der LPL-Compiler übersetzt ein LPL-Programm, das ein vollständiges LP-Model repräsentiert, in zwei interne Dateien. Diese beiden Dateien können ihrerseits wieder übersetzt werden in eine Gleichungsliste, eine Matrix-Darstellung oder in eine MPSX-Datei. LPL beinhaltet ebenfalls eine Schnittstelle zur populären Datenbank dBASEIII, welche erlaubt, Daten, die vom LP-Model gebraucht werden, direkt ab der Datenbank einzulesen.
    Notizen: Summary This paper describes a specialized programming language, named LPL (Linear Programming Language), which may be used to build, modify and document LP models. The LPL language has been successfully applied by the authors to generate automatically MPSX input files of large LP models. The LPL Compiler translates LPL programs, which represent concise and readable LP models, into two internal files. These files may be translated into an explicit equation listing, a picture (matrix layout) or the MPSX input file. LPL includes also a link to the popular relational database management system dBASEIII, which allows the LPL Compiler to read data, used in the LP model, directly from databases.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720038
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  • 28
    Digitale Medien
    Digitale Medien
    Eine Charakterisierung der Unterhalbstetigkeit von Restriktionsmengen (1988)
    Springer
    OR spectrum 10 (1988), S. 67-76 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Summary This paper tries to characterize lower semicontinuous dependence of constraint sets on the constraint functions in convex and quasiconvex optimization. For this purpose the lower semicontinuity of the set theoretic intersection for convex sets is investigated, and we will see, that it is equivalent with the “Non-Separability” of the given convex sets. This “abstract” result contains obviously the solution for the lower semicontinuity of the constraint sets.
    Notizen: Zusammenfassung Die vorliegende Arbeit will charakterisieren, wann sich Restriktionsmengen bei konvexen bzw. quasikonvexen Optimierungsproblemen in Abhängigkeit von den Restriktionsfunktionen unterhalbstetig ändern. Zu diesem Zweck wird die Unterhalbstetigkeit des mengentheoretischen Durchschnitts für konvexe Mengen untersucht, und sie erweist sich als gleichwertig mit der „Nicht-Trennbarkeit“ der gegebenen konvexen Mengen. Dieses „abstrakte“ Ergebnis liefert sofort die Lösung für die Unterhalbstetigkeit der Restriktionsmengen.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720206
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  • 29
    Digitale Medien
    Digitale Medien
    Buchbesprechungen (1988)
    Springer
    OR spectrum 10 (1988), S. 112-112 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720209
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  • 30
    Digitale Medien
    Digitale Medien
    Produktionstheoretische Fundierung industrieller Zuschneideprozesse (1988)
    Springer
    OR spectrum 10 (1988), S. 77-96 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Summary Using an activity analytic approach the fundamentals of a production theory of cutting stock and related processes are developed. Such relations exist to packing and loading processes. The systematic analysis of a few basic assumptions allows production models to be deduced which normally form the starting point in the application oriented literature. Thus the underlying premises of these models become apparent. Therefore prerequisites are created which make the relations between different model approaches easier to recognize, as well as the requirements for the utilization in practice. Some of the statements are also of importance for more general processes of elastic joint production.
    Notizen: Zusammenfassung Auf der Basis eines Ansatzes der Aktivitätsanalyse werden die Grundzüge einer Produktionstheorie der Zuschneideprozesse entwickelt. Die systematische Analyse einiger an den Anfang gestellter Annahmen erlaubt die Ableitung von Produktionsmodellen, welche in der bisherigen, praxisorientierten Literatur der Verschnittoptimierung üblicherweise den Ausgangspunkt bilden. Dadurch werden Voraussetzungen geschaffen, welche es erleichtern, den Zusammenhang zwischen verschiedenen Modellansätzen sowie die Anwendungsvoraussetzungen abgeleiteter Handlungsempfehlungen besser zu erkennen. Eine Reihe abgeleiteter Aussagen besitzt auch Bedeutung für Pack- und Beladeprozesse sowie für allgemeinere Prozesse der elastischen Kuppel- bzw. Resteproduktion.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720207
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  • 31
    Digitale Medien
    Digitale Medien
    A comparison of two optimization procedures for 1- and 1 1/2-dimensional cutting stock problems (1988)
    Springer
    OR spectrum 10 (1988), S. 97-111 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Zur Bestimmung der optimalen Lösung von 1- und 1 1/2-dimensionalen Verschnittproblemen werden zwei verschiedene LP-Modellformulierungen vorgeschlagen. Dies sind zum einen das vollständige Schnittmustermodell, das mit dem bekannten spaltenerzeugenden Verfahren von Gilmore und Gomory [9, 10] gelöst werden kann und zum anderen das Einzelschnittmodell von Rao [17] und Dyckhoff [2, 4], zu dessen Lösung Standardsoftware der Linearen Programmierung einsetzbar ist. Für die beiden Modelle und Lösungsverfahren werden bisher nicht beachtete Gemeinsamkeiten und Unterschiede herausgearbeitet, die Aufschluß über mögliche Anwendungsgebiete und die Vorzüge des jeweiligen Ansatzes erlauben. Es werden sowohl das Standardproblem der Verschnittoptimierung als auch praxisnahe Erweiterungen — wie verschiedene, beschränkt verfügbare Standardlängen und die Bewertung von Restlängen — untersucht. Zur Reduktion des Lösungsaufwandes werden drei auf beide Lösungsansätze anwendbare Reduktionsregeln angegeben. Testrechnungen mit drei aus der Literatur bekannten Verschnittproblemen zeigen die Vor- und Nachteile der beiden Ansätze.
    Notizen: Summary There are two different LP-model formulations to obtain the optimal solution of 1- and 1 1/2-dimensional cutting stock problems. On the one hand there is the complete-cut LP-model which may be solved by the well-known column generation approach of Gilmore and Gomory [9, 10], while on the other hand Rao [17] and Dyckhoff [2, 4] propose an LP-model based on one-cuts to describe the cutting process, to be solved by standard LP software. For both models and solution approaches their commonalities and differences are elaborated, providing insights into possible application areas and the advantages of each approach. We will consider the standard cutting stock problem as well as real world extensions — like the limited availability of standard lengths and the evaluation of residual lengths. Furthermore, three reduction-rules are indicated which can reduce the solution effort. Test runs based on three cutting stock problems mentioned in the literature demonstrate the pros and cons of the two approaches.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720208
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  • 32
    Digitale Medien
    Digitale Medien
    Tagungen (1988)
    Springer
    OR spectrum 10 (1988), S. 124-126 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720211
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  • 33
    Digitale Medien
    Digitale Medien
    Zur Besprechung eingegangene Bücher (1988)
    Springer
    OR spectrum 10 (1988), S. 126-126 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720212
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  • 34
    Digitale Medien
    Digitale Medien
    Practical adaptations of the Gilmore-Gomory approach to cutting stock problems (1988)
    Springer
    OR spectrum 10 (1988), S. 113-123 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die Methode der verzögerten Schnittmuster-Generierung zur Lösung von Verschnittproblemen wurde von Gilmore und Gomory in den frühen 60er Jahren entwickelt. Die wesentlichste Barriere gegen einen verbreiteten Gebrauch der Methode ist ihre Beschränkung auf die Minimierung des Verschnitts. Die in diesem Beitrag beschriebenen Änderungen des Gilmore/Gomory Ansatzes erweitern den Anwendungsbereich. Die Modifikationen beziehen sich auf die Schnittmuster-Generierung der 1. Phase, mehrfache Lösungen pro Rucksackproblem, eine explizite Wertbestimmung von Unter- und Überdeckung der Nachfrage sowie auf einen wertbehafteten Verschnitt. Während einige Änderungen Verbesserungen des klassischen Ansatzes darstellen, erlauben alle Modifikationen zusammen komplexere Zielfunktionspezifikationen.
    Notizen: Summary The delayed pattern generation approach to the solution of cutting stock problems was first proposed by Gilmore and Gomory in the early 1960's. The most significant barrier to its widespread acceptance in commercial applications is its inflexibility in dealing with objectives other than waste minimization. The adaptations of the basic Gilmore-Gomory approach presented in this article increase its flexibility. The adaptations relate to initial pattern generation, multiple solutions per knapsack problem, explicit valuation of undersupply and oversupply, and waste having a value. While some adaptations improve the basic approach, all adaptations lead to the ability to handle objectives more complex than solely waste minimization.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720210
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  • 35
    Digitale Medien
    Digitale Medien
    Buchbesprechungen (1988)
    Springer
    OR spectrum 10 (1988), S. 127-127 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720213
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  • 36
    Digitale Medien
    Digitale Medien
    Buchbesprechungen (1988)
    Springer
    OR spectrum 10 (1988), S. 128-128 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01720214
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  • 37
    Digitale Medien
    Digitale Medien
    Buchbesprechungen (1988)
    Springer
    OR spectrum 10 (1988), S. 144-144 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01740507
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  • 38
    Digitale Medien
    Digitale Medien
    Kostenkontrolle bei mehrstufigen Produktionsprozessen (1988)
    Springer
    OR spectrum 10 (1988), S. 129-143 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Summary Cost control approaches as known in literature are basically restricted to single-stage production processes. In multi-stage production processes the so calledinduced cost variances pose the problem, i.e. applying the two basic cost control approaches which show either the total or the terminal costs of a cost centre it frequently occurs that cost variances are shown in a cost centre, although they were caused and hence induced by preceeding or succeeding cost centres. A new cost control approach is developed which allows identification and assignment of induced cost variances to the responsible cost centres; this general cost control approach can be applied independent of the specific approach chosen, showing either the total costs or the terminal costs. It is built up by analogy to the cost control approach for a single-stage production process, but it also applies to any kind of multi-stage production process.
    Notizen: Zusammenfassung Die aus der Literatur bekannten Kostenkontrollansätze beschränken sich grundsätzlich auf einstufige Produktionsprozesse. In mehrstufigen Produktionsprozessen tritt das Problem der induzierten Kostenabweichungen auf. Bei Anwendung des Gesamtkosten- oder Endkostenansatzes zur Kostenerfassung einer Stelle werden bei mehrstufigen Prozessen Kostenabweichungen ausgewiesen, die von vorgelagerten oder nachgelagerten Stellen verursacht worden sind und damit induzierte Abweichungen darstellen. Zur stellenspezifischen Zuordnung dieser Kostenabweichungen wird daher ein neuer Kontrollansatz konzipiert, der unabhängig vom gewählten Gesamtkosten- oder Endkostenansatz eingesetzt werden kann. Dieser Kostenkontrollansatz ist analog zum Kontrollansatz einstufiger Produktionsprozesse aufgebaut und allgemein für jeden beliebigen Typ mehrstufiger Prozesse einsatzfähig.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01740506
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  • 39
    Digitale Medien
    Digitale Medien
    Geometric fundamentals of the simplex method in semi-infinite programming (1988)
    Springer
    OR spectrum 10 (1988), S. 145-152 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die natürliche Verallgemeinerung des Simplexverfahrens zur Behandlung linearer Optimierungsaufgaben mit unendlich vielen Nebenbedingungen gilt für das Duale Problem. Obwohl der zulässige Bereich zwar konvex im Raume der verallgemeinerten endlichen Folgen ist, behält er viele Eigenschaften vom endlichen Fall, die grundlegend um eine geometrische Deutung des Austausch-schritts zu erzeugen sind. Das Problem der Bestimmung von neuen Basismengen wird ebenfalls behandelt.
    Notizen: Summary The natural extension of the simplex method to linear optimization problems with infinitely many constraints applies to their dual problems. Although the feasible sets are convex sets in spaces of generalized finite sequences, they preserve many of the properties of polyhedral convex sets in finite dimensional spaces. These properties are fundamental in obtaining a geometrical interpretation of the pivot operation. The problem of finding a basic set is also analyzed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01740508
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  • 40
    Digitale Medien
    Digitale Medien
    On efficiency of linear programming applied to discounted Markovian decision problems (1988)
    Springer
    OR spectrum 10 (1988), S. 153-160 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die lineare Programmierung ist zwar bekannt als Lösungsverfahren für diskontierte Markovsche Entscheidungsprobleme, es gibt aber nur wenige numerische Erfahrungen. Bei Verwendung der Simplexmethode können die Einträge des Tableaus auch im Sinne der stochastischen dynamischen Optimierung interpretiert werden. Für lineare Programme, die diskontierte Markovsche Entscheidungsprobleme repräsentieren, stellt eine Simplexmethode, die die spezielle Struktur der Restriktionsmatrix ausnutzt, ein effizientes Verfahren dar, falls (i) der Diskontierungsfaktor nahe bei 1 liegt und die geforderte Genauigkeit groß ist und (ii) entweder die Zustandsräume nicht zu groß oder die Übergangsmatrizen periodisch strukturiert sind.
    Notizen: Summary Linear programming is known as a tool for discounted Markovian decision problems, but there are only a few numerical experiences. If the simplex method is used, the entries of the tableau can be described in terms of stochastic dynamic optimization, too. A simplex method which exploits the special structure of linear programs corresponding to discounted Markovian decision problems turns out to be efficient for problems with (i) discounting factors close to unity and high accuracy, and (ii) either not too large state spaces or periodically structured transition probability matrices.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01740509
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  • 41
    Digitale Medien
    Digitale Medien
    A unified approach to adaptive control of average reward Markov decision processes (1988)
    Springer
    OR spectrum 10 (1988), S. 161-166 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Das klassische Verfahren für die adaptive Steuerung von Markovschen Entscheidungsprozessen mit einem unbekannten Parameter und Durchschnittsgewinn-Kriterium wählt auf jeder Stufe eine Entscheidung, die durchschnittsoptimal ist für das Problem mit dem gerade geschätzten Parameter. Aber in vielen Fällen ist es nicht effektiv oder unmöglich, jeweils die optimale Politik für unendlichen Planungshorizont zu berechnen. Deshalb wurden Verfahren der sukzessiven Approximation vorgeschlagen und untersucht. Hier wird nun ein allgemeiner Ansatz vorgestellt, der die beiden genannten Methoden enthält und darüber hinaus den Rahmen für eine Reihe weiterer Verfahren bietet.
    Notizen: Summary The classical procedure for the adaptive control of average reward Markov decision processes with an unknown parameter chooses at each stage a decision which is optimal for the average reward problem with the presently estimated parameter. But in many cases it is inefficient or impossible to compute each time the long run optimal policy. So successive approximation methods were proposed and investigated. We present a unifying and generalizing approach including both types of methods mentioned above and generating a lot of new procedures, too.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01740510
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  • 42
    Digitale Medien
    Digitale Medien
    Tagungen (1988)
    Springer
    OR spectrum 10 (1988), S. 184-185 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01740513
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  • 43
    Digitale Medien
    Digitale Medien
    A criterion for selecting log-linear models for contingency tables (1988)
    Springer
    OR spectrum 10 (1988), S. 167-172 
    Details
    ISSN: 1436-6304
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Für die Auswahl log-linearer Modelle für Kontingenztafeln wird eine neue Diskrepanz eingeführt, die Gauss Diskrepanz zwischen den Logarithmen der Häufigkeiten. Unter der Annahme, daß die beobachteten Häufigkeiten Poisson-verteilt sind, wird das loglineare Modell für diese Diskrepanz orthogonal: das Modellauswahlkriterium ist die Summe der Beiträge (zum Kriterium) der Effekte im Modell. Zur Auswahl eines Modells genügt es also, die Beiträge der einzelnen Effekte des gesättigten Modells getrennt zu berechnen. Das ausgewählte Modell enthält dann alle Effekte mit negativen Beiträgen. Es ist nicht notwendig, den Wert des Kriteriums für jedes mögliche Modell neu zu berechnen. Zwei Beispiele werden durchgerechnet.
    Notizen: Summary A new discrepancy, the Gauss discrepancy of the logarithms of frequencies, is introduced for the selection of log-linear models for contingency tables. Under the assumption of Poisson sampling the loglinear model becomes orthogonal for this discrepancy: the model selection criterion is the sum of the contributions (to the criterion) of the effects in the model. It is, therefore, sufficient for model selection to compute the contributions of the effects in the saturated model. The selected model contains then all effects with negative contributions. It is not necessary to recompute the value of the criterion for all possible models. Two examples are given.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01740511
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  • 44
    Digitale Medien
    Digitale Medien
    Computer environments for the design of mechanical assemblies: A research review (1988)
    Springer
    Engineering with computers 3 (1988), S. 121-136 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract This paper reviews the most relevant literature dealing with the development of computer environments for the conceptual design of mechanical systems and assemblies. Selected literature is reviewed and discussed in relation to meeting the following requirements of such an environment: (1) representing and supporting top-down design, (2) representing and supporting multiple functional viewpoints, (3) representing functional knowledge, (4) representing spatial relationships and geometry, (5) maintaining consistency, and (6) providing analysis and other support. An appendix listing related readings is included.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01349624
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  • 45
    Digitale Medien
    Digitale Medien
    Development of an expert system for preliminary risk assessment of existing concrete dams (1988)
    Springer
    Engineering with computers 3 (1988), S. 137-148 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract The paper presents an expert system to assist in the field inspection of existing concrete dams within the context of a preliminary risk assessment. The paper describes the engineering knowledge and reasoning required to conduct a deterministic field evaluation of the structural stability of the dam. The symptoms and failure modes identified by the expert system along with the required knowledge and procedures are organized in a structured knowledge tree. The instantiation of the frames and firing of the rules for each consultation traces part of the inference tree contained in the structured knowledge tree. Interaction between nearly decomposable problems are executed with metaknowledge procedures, shared rule groups, and active values. Examples are provided.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01349625
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  • 46
    Digitale Medien
    Digitale Medien
    Computer graphics aided geometric modeling and mesh generation schemes for preprocessing and finite element analysis (1988)
    Springer
    Engineering with computers 3 (1988), S. 157-165 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract The paper describes automated generation and editing schemes together with the development of computer-aided geometric models for general applications. For the construction of general finite element models of complex shapes, conventional approaches typical of wireframe, surface, or solid modeling cannot be effectively utilized for generating continuum solid models as well as discrete models simultaneously. In view of these facts, features to generate and model two-dimensional as well as threedimensional continuum and discrete models by isoparametric mapping/solid geometrical modeling techniques via a common interactive processor are described. The proposed scheme is demonstrated for modeling structural, thermal, or flow networks that are commonly encountered in engineering applications. In a research environment, the techniques addressed in this paper should prove to be very useful in providing flexibility and thereby significantly reducing the work load of frequent CAD users.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01349627
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  • 47
    Digitale Medien
    Digitale Medien
    An intelligent modeling environment for a large engineering analysis code: Design issues and development experience (1988)
    Springer
    Engineering with computers 3 (1988), S. 167-179 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract This paper describes basic research issues and our experience in the development of an intelligent modeling environment for use with a large engineering analysis code. The intelligent environment, the Athena Aide, is a working prototype system that assists analysts in the preparation of models for the ATHENA thermal-hydraulics code. The paper includes the background and basis for our research and descriptions of the analysis code and the intelligent environment, and discusses research topics addressed during the development including design goals, general and specific design issues, information management and representation issues, and user acceptance issues related to the model construction task. Our research has shown that data management is a fundamental consideration during the model construction task and an intelligent environment is a valuable assistant to the analyst in that regard. Providing modeling advice commensurate with the general nature of the analysis code was found to be extremely difficult. For modeling tasks where specific heuristic knowledge has accumulated, useful modeling advice can be provided.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01349628
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  • 48
    Digitale Medien
    Digitale Medien
    Providing data base management for the CAD environment: The AREDAS approach (1988)
    Springer
    Engineering with computers 3 (1988), S. 207-223 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract In recent years there has been an increasing interest in the integration of data base management systems (DBMSs) into the CAD environment. The motivation for this interest is discussed and several problems are identified that have to be solved in order to yield a genuine coupling of DBMSs and CAD systems. A solution to these problems is proposed in the form of a new architecture for a CAD-DBMS. Based on this, a preliminary implementation is outlined that follows a rapid prototype approach, and in wh ich an access as well as a transaction manager were realized for a software-based fileserver/workstation topology. Some directions for future work are described.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01202142
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  • 49
    Digitale Medien
    Digitale Medien
    An evaluation of programming languages and language features for engineering software development (1988)
    Springer
    Engineering with computers 3 (1988), S. 183-199 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract This article addresses the need for engineers to have a working knowledge of the fundamental structures of computer programming languages. In pursuit of this, it briefly looks at the history behind four of the more well-known programming languages. It then attempts to identify, and to look critically at, the attributes of programming languages that significantly affect the production of engineering software. The four “traditional” procedural programming languages chosen for review are those intended for scientific and general purpose programmin—FORTRAN-77, C, Pascal, and Modula-2. These languages are compared and some general observations are made. The emphasis of this article is on the attributes, characteristics, and components of programming languages that are important to software development and maintenance. Consequently, the comparison itself is of secondary importance, with the actual methodology of comparison given prominence in order that professional engineers who need to develop engineering software are able to make rational decisions about the choice of a programming language. Choosing an appropriate language can be a complex task and many factors must be considered. Therefore, in this article the fundamental structures, constructs, and attributes of programming languages are discussed, with very little attention given to the specific syntax of any particular language.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01202140
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  • 50
    Digitale Medien
    Digitale Medien
    Information technology development: A management perspective (1988)
    Springer
    Engineering with computers 4 (1988), S. 3-10 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract The opportunities of the information age present a real challenge to business management today. To meet this challenge, and to realize the true benefits of information technology, management must get involved and provide leadership in defining the business direction for an enterprise. It is through this involvement that the enterprise can apply technology to make the maximum impact on how business is conducted. Major information system development projects at General Dynamics Fort Worth will impact the way product definition data is managed and provide an example of how information technology can change the way we do business.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01201467
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  • 51
    Digitale Medien
    Digitale Medien
    Data base system considerations in engineering design (1988)
    Springer
    Engineering with computers 4 (1988), S. 19-26 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract A general structural design procedure, including general development and maintenance steps, is outlined from a data requirements perspective. Within each phase of the design process, certain data is required for the undertaking and completion of each design step. As the various steps in the design process such as component and prototype testing and in-service experience generate new or additional data, that information should be incorporated into the data banks for use in current and future designs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01201469
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  • 52
    Digitale Medien
    Digitale Medien
    The integrated analysis capability (IAC level 2.0) (1988)
    Springer
    Engineering with computers 4 (1988), S. 53-63 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract The integrated analysis capability (IAC) provides a computational environment that supports the unique needs of engineering analysis groups concerned with interdisciplinary problems. An essential part of IAS is the data management system, which is designed both to maximize computational efficiency and to support a full range of data query and manipulation. This paper described data management issues that we have found to be of critical importance in the IAC development. Because the computational environment of a system such as IAC has a strong influence on the software design trades and decisions, the paper also summarizes the overall system architecture and some of the developments relative to technical modules and data flow requirements. The information presented here is intended to aid potential users in evaluating and selecting an integrated capability, as well as software developers faced with the task of creating or expanding such a capability.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01201472
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  • 53
    Digitale Medien
    Digitale Medien
    Strain measurement of structures with curved surface by means of personal computer-based picture processing (1988)
    Springer
    Engineering with computers 3 (1988), S. 149-156 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract An optical strain measurement system was developed that includes computer processing of stereoscopic picture data of marks painted on the specimen. This system allows us to measure large strains in specimens with curved surfaces as well as plane surfaces even at elevated temperatures. The results of a verification test performed on a bellows specimen at room temperature have shown that the strain error of this measurement system is allowable considering the limitation of the apparatus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01349626
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  • 54
    Digitale Medien
    Digitale Medien
    Announcement (1988)
    Springer
    Engineering with computers 3 (1988), S. 181-181 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01349629
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  • 55
    Digitale Medien
    Digitale Medien
    The introduction of constraints into a graphics system (1988)
    Springer
    Engineering with computers 3 (1988), S. 201-205 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract Often a computer-aided design system acts merely as a storehouse for a collection of graphical entities. It has no knowledge of how these interrelate or what the purpose is of the design that they represent. The work described is an initial attempt to enable the user of a system interactively to provide information of this type. This is done in terms of constraints upon the geometric entities that are defined, along with these entities themselves, in a user interface language.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01202141
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  • 56
    Digitale Medien
    Digitale Medien
    Parallel processsing in finite flement structural analysis (1988)
    Springer
    Engineering with computers 3 (1988), S. 225-241 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract A brief review is made of the fundamental concepts and basic issues of parallel processing. Discussion focuses on mechanisms for parallel processing, construction and implementation of parallel numerical algorithms, performance evaluation of parallel processing machines and numerical algorithms, and parallelism in finite element computations. A novel partitioning strategy is outlined for maximizing the degree of parallelism on computers with a small number of powerful processors.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01202143
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  • 57
    Digitale Medien
    Digitale Medien
    Preface (1988)
    Springer
    Engineering with computers 4 (1988), S. 1-1 
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    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01201466
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  • 58
    Digitale Medien
    Digitale Medien
    Coping with legacy factors (1988)
    Springer
    Engineering with computers 4 (1988), S. 11-17 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract Implementers of engineering data base management systems inherit a legacy of existing software and data that must be integrated into the new system with minimum disruption of ongoing activities. Some critical issues addressed here include changes in software engineering practices, impact on user training and procedures, and problems connected with traditional or parochial interests. The material covered describes some experiences in coping with these “legacy factors” during the recent McDonnell Aircraft Company (MCAIR) integrated data base implementation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01201468
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  • 59
    Digitale Medien
    Digitale Medien
    Integrated design support system (1988)
    Springer
    Engineering with computers 4 (1988), S. 27-37 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract The integrated design support system (IDS) is a concept for capturing the “critical” technical engineering information necessary to perform the functions of maintenance, modification, repair, and reprocurement of Air Force weapon systems. The program will first construct an architecture to define the required information. Next, IDS will construct prototype software to acquire, store, distribute, and perform configuration management on the data. The program will conclude with software simulation of the full-scale IDS system operating in a production environment to determine performance characteristics together with development and operatonal costs for the system.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01201470
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  • 60
    Digitale Medien
    Digitale Medien
    An aide for instruction on integrated engineering design and support (1988)
    Springer
    Engineering with computers 4 (1988), S. 39-52 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract Effective management of engineering information is critically needed for the design of future complex engineering systems. Yet engineers are not trained in engineering data base management concepts. To help address this issue, a prototype integrated design system has been developed for the Air Force to aide research and instruction on key integration concepts, including (1) the use of a shared data base to eliminate redundancies and inconsistencies; (2) the use of a relational data base management system to store, locate, and retrieve data from the shared data base; (3) the development of interfacing programs to act as interpreters between the application programs and the common data base; and (4) the role of executive software to manage the integrated system. Key software used includes a computer-aided design system, a structural analysis program, various graphics packages, and a relational data base management system. To assess system flexibility, additional programs were added to the system. The design of the data base proved to be an important step in this implementation. Several methodologies useful in the design of the data base were investigated and subsequently used to organize the data base for the integrated design system. Results discussed include system development, and applications, as well as the effectiveness of the integrated system's configuration.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01201471
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  • 61
    Digitale Medien
    Digitale Medien
    Sources and standards for computerized materials property data and intelligent knowledge systems (1988)
    Springer
    Engineering with computers 4 (1988), S. 75-85 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract The explosion of interest in computerized material property data bases and intelligent knowledge systems for flexible manufacturing processes has resulted in two significant developments in the last couple of years: the incorporation of the National Materials Property Data Network, Inc. (MPD Network), and the formation of ASTM Committee E-49 on Computerization of Material Property Data. The MPD Network has the mission of providing engineers and scientists with easy on-line access to worldwide sources of reliable, well-documented material property data. The status of its pilot network and plans for the future are outlined herein. ASTM Committee E-49 has the mission of developing and providing guidelines and standards to aid the builders, maintainers, and suppliers of data bases in meeting the needs of industry and in establishing compatible and consistent sources capable of sharing data. Also reported in this paper is the early progress of the Technical Committee of the MPD Network in establishing guidelines for the evaluation of data, recognizing that there are a number of aspects of data source building and management requiring audit as well as the data itself. It is important that sources of material performance data are well characterized, and that the nature and reliability of the information is conveyed to the user. The further development of guidelines and standard practices in this area will also be dealt with by ASTM Committee E-49. A brief overview of other major material property data base building activities in the United States is also provided.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01201474
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  • 62
    Digitale Medien
    Digitale Medien
    Analyzing technological change: An engineering data base for input-output models of the economy (1988)
    Springer
    Engineering with computers 4 (1988), S. 99-105 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract This paper describes the content and logical structure of an engineering data base, to be constructed from direct technical information, for use with input-output (IO) models of the national economy. These models, which until now have relied almost exclusively on accounting information describing past economic transactions, can now be extended to analyze the future prospects for the U.S. economy and its individual sectors in terms of detailed technical decisions taken at the sites of production. The basic IO data base describes each sector's input in terms of its use of given amounts of goods and services produced in all sectors, per unit of its output. The new data base will distinguish the individual activities carried out within a sector, specify the important technical alternatives for each activity, and describe each alternative in terms of inputs of the required goods and services. The structure of the new data base accommodates the quantification of both production and “overhead” activities and their integration, and its implementation in stages is facilitated by the fact that it is a generalization of the structure of existing IO data bases.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01201476
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  • 63
    Digitale Medien
    Digitale Medien
    A LISP-based object-oriented approach to structural analysis (1988)
    Springer
    Engineering with computers 4 (1988), S. 197-203 
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    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract An approach to structural analysis is presented in which object-oriented data structures make it possible to arrange computational tasks in a unique fashion. A general matrix-free solution algorithm for use with arbitrary assemblages of linearly connected objects is presented, followed by an overview of a prototype structural analysis program built entirely on such an object-oriented data structure. The principal result is due to the flexibility inherent in this type of data structure, which makes it possible to analyze structural models incrementally as they are developed. Although certainly useful in traditional contexts, the parallel nature of the scheme could be particularly powerful in a multiprocessor environment.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01213981
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  • 64
    Digitale Medien
    Digitale Medien
    User interfaces for structural engineering relational data base (1988)
    Springer
    Engineering with computers 4 (1988), S. 239-249 
    Details
    ISSN: 1435-5663
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik , Maschinenbau , Technik allgemein
    Notizen: Abstract The needs of engineers in their interaction with engineering data bases are very different from those of their counter-parts in the business world. Business data base management system interfaces typically provide only a single mode of textual communication, usually a structured query language. However, in an idealengineering data base interface, an engineer would be able to define constraints, give examples, point at parts of pictures, and (sometimes) use several modes of communication simultaneously. The paper presents an example from an engineering design application to show how a traditional query language can be enhanced to accommodate the engineering needs. The paper further describes a conceptual approach for multimodal engineering data base interface combining multipurpose graphics, an engineering query language, and other interface methodologies in an engineering workstation environment.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01213985
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  • 65
    Digitale Medien
    Digitale Medien
    Tracing the composition changes of Japan's consumer budget, 1920–1980 (1988)
    Springer
    Empirical economics 13 (1988), S. 59-64 
    Details
    ISSN: 1435-8921
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Wirtschaftswissenschaften
    Notizen: Abstract Data over a wide time span are used to verify the superiority of a demand system over simple alternatives.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01971886
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  • 66
    Digitale Medien
    Digitale Medien
    Innovative behaviour, agglomeration economies and R&D infrastructure (1988)
    Springer
    Empirical economics 13 (1988), S. 35-57 
    Details
    ISSN: 1435-8921
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Wirtschaftswissenschaften
    Notizen: Summary The present paper aims at analyzing two important conditions that — according to conventional wisdom — are assumed to act as driving forces for innovative behaviour of firms. The first condition is reflected in the so-called urban size hypothesis, which presupposes a close relationship between agglomeration size and innovative behaviour. The second condition incorporates the R&D infrastructure hypothesis, which assumes a positive impact of the presence of a research and knowledge infrastructure on innovative behaviour. Both hypotheses are tested on the basis of Dutch micro data on entrepreneurial innovations. In this framework, this paper also designs and employs a new and detailed measure for spatial agglomeration economies. It is concluded that the first hypothesis is in general difficult to validate, because in the Netherlands central cities are not in general more innovative. In this context, a third factor has been introduced, viz. the industrial composition effect. It is asserted (and demonstrated by means of loglinear modelling) that this factor — in combination with agglomeration economies — is a major determinant of the geographical distribution of innovations. As far as the second hypothesis is concerned, the results — based on Kendall's concordance coefficient — do not indicate the existence of a close correlation between R&D infrastructure and the spatial dispersion of innovations either.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01971885
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  • 67
    Digitale Medien
    Digitale Medien
    Semiparametric and nonparametric econometrics (1988)
    Springer
    Empirical economics 13 (1988), S. 121-122 
    Details
    ISSN: 1435-8921
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Wirtschaftswissenschaften
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01972443
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  • 68
    Digitale Medien
    Digitale Medien
    Testing for short-run money neutrality in a small open economy: The case of Canada (1988)
    Springer
    Empirical economics 13 (1988), S. 103-120 
    Details
    ISSN: 1435-8921
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Wirtschaftswissenschaften
    Notizen: Abstract This paper adopts an econometric methodology which is based on standard nested-hypotheses testing in order to test the policy ineffectiveness proposition in the context of the Canadian economy. It thus avoids some problems associated with the non-nested hypotheses framework used by Barro and numerous other writers. The substantial openness of the Canadian economy is taken into account through the use of a Mundell-Flemming aggregate demand side. The supply response of the economy is carefully modelled, in the same context, and the familiar Sargent-Wallace aggregate supply function is derived as a special case of a more general Keynesian function — by assuming instantaneous adjustment of prices to costs. Empirical tests based on a data sample spanning the period of Canada's recent experience with flexible exchange rates are unfavorable to the policy ineffectiveness proposition.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01973317
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  • 69
    Digitale Medien
    Digitale Medien
    Nonparametric kernel estimation applied to forecasting: An evaluation based on the bootstrap (1988)
    Springer
    Empirical economics 13 (1988), S. 141-154 
    Details
    ISSN: 1435-8921
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Wirtschaftswissenschaften
    Notizen: Abstract The results reported in this paper lend support to the nonparametric approach to estimating regression functions. This conclusion is based on a comparison of two sets of eight quarterly forecasts of U.S. hog supply generated by a well specified parametric dynamic model and by nonparametric kernel estimation. Despite the relatively small sample size, the nonparametric point forecasts are found to be as accurate as the parametric forecasts according to the mean square error and mean absolute error criteria. Bootstrap resampling is used to estimate the distributions of the forecast errors. The results of this exercise favour the nonparametric forecasts, which are found to have a tighter distribution.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01972445
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  • 70
    Digitale Medien
    Digitale Medien
    Bayes prediction density and regression estimation — A semiparametric approach (1988)
    Springer
    Empirical economics 13 (1988), S. 209-222 
    Details
    ISSN: 1435-8921
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Wirtschaftswissenschaften
    Notizen: Abstract This paper is concerned with the Bayes estimation of an arbitrary multivariate density,f(x), x ∃ R k. Such anf(x) may be represented as a mixture of a given parametric family of densities {h (x¦θ)} with support inR k, whereθ (inR d) is chosen according to a mixing distributionG. We consider the semiparametric Bayes approach in whichG, in turn, is chosen according to a Dirichlet process prior with given parameterα. We then specialize these results whenf is expressed as a mixture of multivariate normal densitiesΦ (x¦Μ, λ) whereΜ is the mean vector and λ is the precision matrix. The results are finally applied to estimating a regression parameter.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01972449
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  • 71
    Digitale Medien
    Digitale Medien
    The role of fiscal policy in the St. Louis model: Nonparametric estimates for a small open economy (1988)
    Springer
    Empirical economics 13 (1988), S. 169-186 
    Details
    ISSN: 1435-8921
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Wirtschaftswissenschaften
    Notizen: Abstract This paper reevaluates the efficacy of monetary and fiscal policies and bidirectional causality between income and each of the policy instruments used in the St. Louis model for aggregate demand using nonparametric (or infinite parametric) spectral methods. We proceed by estimating the strength of the correlations (or partial coherences) between income and each of the policy instruments over various frequencies. Then we obtain the corresponding band regression and Hannan's efficient estimates of both the lead and lag coefficients in the St. Louis model. The analysis is carried out with seasonally adjusted quarterly data and is divided into the flexible, fixed, and managed flexible exchange rate regimes. We find that while estimates from parametric regressions yield the standard conclusions for the St. Louis model, results from the nonparametric analysis are quite different. Specifically, the results of our analysis reveal that (i) both monetary and fiscal instruments are strongly correlated with income over cycles of 10 quarters or longer for the most recent period of the managed flexible exchange rate regime, and (ii) bidirectional causality exists between income and the fiscal policy instrument. These results suggest that both monetary and fiscal policy have a long-lasting effect on aggregate demand and that bidirectional causality exists between income and policy instruments. An explanation for the existence of bidirectional causality might be that the Canadian government generally pursued a purposeful discretionary fiscal policy during the post-World War II period. Furthermore, it appears that discretionary policy action may have been anticipated by rational, farsighted, and forward-looking economic agents. Finally, our results for the flexible exchange rate and fixed rate regimes are in agreement with the Mundell-Fleming view of the role of monetary fiscal policy in an open economy.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01972447
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  • 72
    Digitale Medien
    Digitale Medien
    Some simulation studies of nonparametric estimators (1988)
    Springer
    Empirical economics 13 (1988), S. 251-266 
    Details
    ISSN: 1435-8921
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Wirtschaftswissenschaften
    Notizen: Abstract This paper constructs a number of Monte Carlo studies to assess the quality of various nonparametric estimators that have been proposed recently for the estimation of nonlinear econometric models. We consider both kernel and Fourier series based methods of estimation, and also examine techniques that have been suggested to improve the bias properties of the kernel estimator. The two models examined are a production function and a model emphasising the effects of risk. The Fourier estimator does very well in estimating the first of these, but not the second, while the kernel estimator shows substantial bias for the first, which is only partially alleviated by the procedures advocated for bias correction, and good results for the second.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01972451
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  • 73
    Digitale Medien
    Digitale Medien
    Estimating a hedonic earnings function with a nonparametric method (1988)
    Springer
    Empirical economics 13 (1988), S. 267-294 
    Details
    ISSN: 1435-8921
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Wirtschaftswissenschaften
    Notizen: Abstract In this paper we apply the nonparametric approach of Bierens and Hartog (1988) to estimating and testing an earnings function which emphasizes the simultaneous impact of supply characteristics (like education) and demand characteristics (like job level). The data support this emphasis and point to significant non-linearities. In particular, job level comes out as an important variable.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01972452
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  • 74
    Digitale Medien
    Digitale Medien
    Structure property behavior of polydimethylsiloxane and poly(tetramethylene oxide) modified TEOS based sol-gel materials (1988)
    Springer
    Polymer bulletin 19 (1988), S. 51-57 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary Titanium has been successfully incorporated into polydimethylsiloxane and poly(tetramethylene oxide) modified TEOS based materials using sol-gel chemistry. Incorporation of titanium into the oligomer modified TEOS based materials altered the physical properties, however, the gross structural features remained the same.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00255023
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  • 75
    Digitale Medien
    Digitale Medien
    The combined use of two-dimensional NMR and lanthanide shift reagents for the characterization of ethylene — vinyl acetate copolymers (1988)
    Springer
    Polymer bulletin 19 (1988), S. 89-96 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary Two-dimensional NMR and lanthanide shift reagents have been combined for the first time for NMR spectral assignments. The combined approach permitted very detailed interpretation to be made of the one-dimensional 1H and 13C spectra of ethylene-vinyl acetate copolymers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00255028
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  • 76
    Digitale Medien
    Digitale Medien
    Polyisobutylene-based urethane foams (1988)
    Springer
    Polymer bulletin 19 (1988), S. 137-143 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary The rates of urethane formation between linear and three-arm star hydroxyl-terminated polyisobutylenes (PIB-diols and -triols) and 4,4′-diphenylmethane diisocyanate (MDI) have been studied in the presence of triethylene diamine and stannous octoate catalysts in chlorebenzene at 25°C. The second order rate constants were determined and compared with those obtained with various polyether triols, hydroxyl-terminated polybutadiene and hydroxyl-terminated polyolefin. The rates of the normalized PIB-diol/MDI and PIB-triol/MDI reactions are essentially identical. In the presence of triethylene diamine, the rates of the PIB-diol and PIB-triol/MDI reactions are the same or much higher than that of the polyether-triol/MDI reaction. In contrast, in the presence of stannous octoate, the rates of the PIB-diol and PIB-triol/MDI reactions are much slower than that of the polyether-triol/MDI reaction. Differences in catalytic pathways are invoked to explain these observations. The reactivities of hydroxyl-terminated PIBs are similar to those of other hydroxyl-terminated polyhydrocarbons and sufficient for the synthesis of foams.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00257006
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  • 77
    Digitale Medien
    Digitale Medien
    Chemical transformation of PVC by phase transfer catalysis (1988)
    Springer
    Polymer bulletin 19 (1988), S. 59-63 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary Suspension type PVC was reacted with sodium phenoxide in presence of different quaternary ammonium halides in THF or THF/water mixtures. The competition elimination vs. substitution of chlorine atoms depends on the homogeneity of the system, i.e. the more homogeneous the reaction mixture the less substituted the polymer.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00255024
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  • 78
    Digitale Medien
    Digitale Medien
    Preparations of 4-(2-chloroethyl)styrene, 4-(2-chloroethyl) α-acetoxystyrene and 4-(3-bromopropyl)α-acetoxystyrene (1988)
    Springer
    Polymer bulletin 19 (1988), S. 111-117 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary Functionalized styrenes such as 4-(2-chloroethyl)styrene, 4-(2-chloroethyl)α-acetoxystyrene and 4-(3-bromopropyl)α-acetoxystyrene have been synthesized in two steps from commercial products and a preliminary study of their polymerization and copolymerization has been carried out.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00257002
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  • 79
    Digitale Medien
    Digitale Medien
    Copolymerization via zwitterion (1988)
    Springer
    Polymer bulletin 19 (1988), S. 123-128 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary Copolymers of 2-ethyl-2-oxazoline (ETOX) and N-phenylmaleimide(PhMI) without initiator were prepared at different feed mole ratios, solvents, temperatures and times. The copolymers are almost statistical and rich in N-phenylmaleimide. The copolymer composition was determined by 1H NMR.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00257004
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  • 80
    Digitale Medien
    Digitale Medien
    The linear master dependence for polymer melts in the non-Newtonian range (1988)
    Springer
    Polymer bulletin 19 (1988), S. 165-169 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary The multivariable power function Δ ϕ · ηo = B( $$\dot \gamma $$ η o)b 1· qb 2· Gb 3 (symbols are explained in the text) is proposed as the general linear master dependence for the behaviour of linear and branched polymer melts in the non-Newtonian range. It can be applied for generation of any flow curve for a given polymer sample provided that constants B, b1, b2 and b3 are known. It has been found, using the experimental data on polycarbonate, that B is approximately equal to 3×10−5 being the universal constant, and b1=0.77 for linear polymers. Lower values of b1 indicate the existence of branched macromolecules, and the relationship of b1 vs G can be used for determination of branching degrees from the rheological data.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00257011
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  • 81
    Digitale Medien
    Digitale Medien
    Interpolymer complexation between poly(ethylene oxide) and poly(acrylic acid) (1988)
    Springer
    Polymer bulletin 19 (1988), S. 171-177 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary Solution and solid state properties of the interaction between poly(acrylic acid) and poly(ethylene oxide) have been studied in the presence and absence of CaSO4 in water or in methanol systems. The association in solution has been investigated by viscosity measurements and NMR spectroscopy. The solid state of the systems has been studied using DSC, IR, X-RAY and 13-C-CPMAS-NMS. Complex formation is also clearly indicated.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00257012
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  • 82
    Digitale Medien
    Digitale Medien
    Preparation of PMMA macromers by o-vinylbenzylmagnesium chloride and their polymerization (1988)
    Springer
    Polymer bulletin 19 (1988), S. 231-237 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary Polymerization of MMA with o-vinylbenzylmagnesium chloride was examined in toluene and in tetrahydrofuran (THF) at various temperatures. The polymer formed in toluene at −78°C was highly isotactic (mm=94%) and containing one vinylbenzyl group at the α-end of the chain, although the methanol-soluble fraction concomitantly formed in an appreciable amount was less isotactic. The PMMAs formed in THF at −78 and −98°C were mostly methanol-soluble and highly syndiotactic (rr=88% at −78°C and 96% at −98°C), and also contained one vinylbenzyl group. The methanol-soluble, isotactic and syndiotactic PMMA macromers were polymerized or copolymerized with styrene by AIBN in toluene at 60°C. The isotactic macromer exhibited slightly higher reactivity than the syndiotactic one.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00255377
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  • 83
    Digitale Medien
    Digitale Medien
    Melting point depression in poly(ɛ-caprolactone) / poly(styrene-co-acrylonitrile) blends (1988)
    Springer
    Polymer bulletin 19 (1988), S. 283-288 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary The melting point depression of poly(ɛ-caprolactone)/poly(styrene-co-acrylonitrile) (PCL/SAN) blends with changes in acrylonitrile content of SAN and in blend ratio was investigated by differential scanning calorimetry. For the melting points at a constant blend ratio occur a minimum in dependence on the copolymer composition for blends containing about 20 wt% acrylonitrile in SAN. From melting point depression data a negative, binary interaction parameter was obtained for PCL/SAN blends containing a SAN with 19.2 wt% AN. By optical microscopy it can be shown that the shape of the spherulites changes with copolymer composition of SAN and blend ratio.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00255385
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  • 84
    Digitale Medien
    Digitale Medien
    Tacticity dependence of excimer formation in polystyrene solutions (1988)
    Springer
    Polymer bulletin 19 (1988), S. 311-317 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary This work deals with the excimer formation in dilute solution for a series of polystyrenes of various tacticity prepared by epimerization of an initial isotactic sample. The main result is that the relative excimer yield remains equal to that obtained for iPS if the percentage of isotactic dyads is higher than 65%.The range of energy migration could be roughly approximated to 6 chromophores.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00255389
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  • 85
    Digitale Medien
    Digitale Medien
    Synthesis and biodegradation of copolyesters from citric acid and glycerol (1988)
    Springer
    Polymer bulletin 19 (1988), S. 365-370 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary Seven samples of cross-linked co-polyesters of citric acid and glycerol from seven different mole ratios of the reactants have been synthesised as initially insoluble amorphous solids which become soluble in water within 8–10 days due to partial hydrolysis of the cross-links. They have been characterised by their IR spectra, glass transition temperature and swelling behaviour. The acid to glycerol mole ratios 0.83 and 0.88 produce maximum cross-link density. Microbial degradation of the polymer samples in aqueous suspension has been studied using the fungus Aspergillus niger and the bacterium E. coli. All the polymer samples are degraded by Aspergillus niger and E. coli and the more cross-linked products have been found to be more degradable. The possible use of these cross-linked co-polyesters as matrices for controlled release of drugs has been illustrated.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00263938
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  • 86
    Digitale Medien
    Digitale Medien
    Synthesis and thermoelastic characterization of PDMSM networks (1988)
    Springer
    Polymer bulletin 19 (1988), S. 377-384 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary The synthesis of poly(dimethyl silmethylenes) with two hydroxyl endgroups is described. Networks produced by endlinking with tetraethoxysilane were characterized, and thermoelastic data were estimated. fe/f and dln〈L2〉o/dT of these networks are much smaller than those of poly(dimethyl siloxanes).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00263940
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  • 87
    Digitale Medien
    Digitale Medien
    Calculation of orientation factors for crystalline polymers from X-ray pole figure intensities (1988)
    Springer
    Polymer bulletin 19 (1988), S. 389-395 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary The characterization of polymer orientation is discussed by expanding the orientation distribution function (ODF) for the crystalline phase into a series of generalized spherical harmonics (GSH) or into a series of symmetric generalized spherical harmonics (SGSH). A transformation relation is derived between the two expansions. By means of this transformation the orientation factors (moments of the ODF) can be calculated from the SGSH series expansion coefficients. As an example, this transformation is demonstrated for crystals of hexagonal symmetry and fiber texture.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00263942
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  • 88
    Digitale Medien
    Digitale Medien
    Simple synthesis of polymeric primary aromatic amines (1988)
    Springer
    Polymer bulletin 19 (1988), S. 423-426 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary A new simple and versatile method of obtaining polymers bearing aromatic primary amino groups was developed. The method consists in the reaction of an alkylating polymer with sodium 4-acetylaminobenzenesulfinate and subsequent deacetylation of the intermediate polymer by acid hydrolysis. Alkylating polymers such as chloromethylated polystyrene resin, tosylated macroporous poly (2-hydroxyethyl methacrylate), macroporous poly(glycidyl methacrylate) and PVC were used in the alkylation performed either in an organic swelling solvent or in an aqueous suspension under phase transfer catalysis conditions. Yields in the alkylation step depend largely on the type of the alkylating group, hydrolysis yields are essentially quantitative.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00263909
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  • 89
    Digitale Medien
    Digitale Medien
    Processes occurring during the induction period of inhibited oxidation of polyethylene (1988)
    Springer
    Polymer bulletin 19 (1988), S. 449-455 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary The kinetics of oxygen consumption during the induction period of oxidation of high density polyethylene was studied in the presence of inhibitor 2,2'-methylene-bis(4-methyl-6-tert.butylphenol) within the range 180–220° C. The oxygen consumption curves are complicated, the initial and maximum rates of oxygen consumption pass through minimum with increasing inhibitor concentration. The molecular weight distribution narrows in the course of inhibited oxidation. Analysis of the regularities found enabled us to distinguish the rates of oxygen consumption by the polymer and by the inhibitor.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00263913
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  • 90
    Digitale Medien
    Digitale Medien
    Synthesis and polymerization of 2-(β-N-3′-halogencarbazolylethyl)-2-oxazolines (1988)
    Springer
    Polymer bulletin 20 (1988), S. 11-14 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary The synthesis of three novel oxazoline monomers,all of which contain 3-halogen substituted carbazolyl groups [i.e., 2-(β-N-3′ chlorocarbazolylethyl)-2-oxazoline, 2-(β-N-3′ bromocarbazolylethyl)-2-oxazoline and 2-(β-N-3′ iodocarbazolylethyl)-2-oxazoline]and their polymerization is described.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00262242
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  • 91
    Digitale Medien
    Digitale Medien
    Group transfer polymerisation of acrylonitrile (1988)
    Springer
    Polymer bulletin 20 (1988), S. 243-246 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary The polymerization of acrylonitrile, initiated by titanium amides, is interpreted in terms of a group-transfer mechanism.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00261975
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  • 92
    Digitale Medien
    Digitale Medien
    Hydrophilic/hydrophobic IPN membranes for the pervaporation of ethanol-water mixture (1988)
    Springer
    Polymer bulletin 20 (1988), S. 261-267 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary Pervaporation of ethanol-water mixture was examined on IPN membranes composed of hydrophilic polyurethane(PU) and hydrophobia polystyrene(PS). The IPN membranes showed preferential pervaporation of water over ethanol and revealed high permeation rate. As the content of hydrophobic PS was increased, the permeation rate decreased while the separation factor increased, indicating that the PS domains suppressed the swelling of the PU phase and reduced the plasticizing effect. The average diffusion coefficient, computed from the permeation rate and solubility, was highly dependent on the viscosity and concentration of the permeant in the membrane.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00261979
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  • 93
    Digitale Medien
    Digitale Medien
    Synthesis of poly[1-(trimethylsilyl)-1-propyne] with a narrow molecular weight distribution by using NbCl5 catalyst in cyclohexane (1988)
    Springer
    Polymer bulletin 20 (1988), S. 1-6 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary The polymerization of 1-(trimethylsilyl)-1-propyne [CH3C≡CSi(CH3)3] catalyzed by NbCl5 in cyclohexane solution produced a polymer having a narrow molecular weight distribution (MWD). In this polymerization, the number-average molecular weight (Mn) of the polymer increased in direct proportion to conversion, while the MWD of the polymer remained narrow (Mw/Mn∼ 1.2) irrespective of the conversion. Poly[1-(trimethylsilyl)-1-propynels having narrow MWD and Mn in the range 1×104 –20×104 could be obtained by changing the ratio of monomer to catalyst. Thus, the present polymerization involves a long-lived propagating species, and provides a useful method for synthesizing poly[1-(trimethylsilyl)-1-propyne] with a narrow MWD.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00262240
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  • 94
    Digitale Medien
    Digitale Medien
    Asymmetric polymerization of diphenyl-2-pyridylmethyl methacrylate leading to optically active polymer with high one-handed helicity (1988)
    Springer
    Polymer bulletin 20 (1988), S. 25-30 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary Diphenyl-2-pyridylmethyl methacrylate (D2PyMA) was polymerized with organolithium complexes of four novel chiral ligands (1–4) which were prepared from (+)-tartaric acid. The complexes of 3 and 4 gave the optically active poly (D2PyMA) with a highly one-handed helical structure. The fractionation of the polymer afforded the poly (D2PyMA) with almost pure one-handed helicity ([α] 365 25 ∿-1400°) in good yield. These chiral lithium complexes were not effective for the asymmetric polymerization of triphenylmethyl methacrylate.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00262245
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  • 95
    Digitale Medien
    Digitale Medien
    Functional polymers. LIV. Photochemical behavior of 2(2-hydroxyphenyl)2H-benzotriazole derivatives (1988)
    Springer
    Polymer bulletin 20 (1988), S. 67-74 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary The absorption spectra of 2(2-hydroxyphenyl)2H-benzotriazoles derivatives substituted with electron-donating and withdrawing groups in various positions on the phenyl ring allowed to estimate the relative stability of the hydrogen-bonded structures as evidenced by the ɛ 340 nm/ɛ300 nm ratio. Photodegradation studies of poly-cis-1,4-butadiene-1,3 with and without 2(2-hydroxyphenyl) benzotriazole absorbers with various substituents show that compounds with R=H are better photostabilizers than those with R≠H.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00262251
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  • 96
    Digitale Medien
    Digitale Medien
    Degradation of HDPE and LLDPE in closed mixing chamber: a comparison (1988)
    Springer
    Polymer bulletin 20 (1988), S. 89-96 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary HDPE and LLDPE (containing n-butyl branches) were degraded in a closed mixing chamber. After degradation some physical and mechanical properties were investigated as a function of the chemical structure of the polymers. The effect of degradation was found different for the two materials. Physical and mechanical properties of HDPE depend strongly on crystallization conditions and chemical irregularities of the polymer chain. The most pronounced change in physical properties was found as an effect of oxygen incorporation into the polymer at the beginning of the process. Tensile properties of the samples have shown rapid destruction after the yield point. Physical and mechanical properties of LLDPE reveal much less dependence on crystallization conditions and changes of the chemical structure. Chemical changes caused by degradation of the polymer do not essentially change the degree of crystallinity under the conditions investigated. Chain breaking of the polymer results in a slight decrease in the tensile properties, which can be attributed to the decrease in the number of tie-chains.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00262254
    Standort Signatur Erwartet Verfügbarkeit
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  • 97
    Digitale Medien
    Digitale Medien
    Synthesis of oxidation stabilized cyclopentadiene polymers via cationic copolymerization with 4-isopropenylphenol (1988)
    Springer
    Polymer bulletin 20 (1988), S. 109-115 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary A method is described to improve the oxidation stability of cyclopentadiene co- and terpolymers via cationic polymerization using 4-isopropenylphenols as polymerizable comonomers. The efficiency of these phenols depends on their part in the copolymer and on the number and size of their alkyl groups.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00256102
    Standort Signatur Erwartet Verfügbarkeit
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  • 98
    Digitale Medien
    Digitale Medien
    Polymeric reagents (1988)
    Springer
    Polymer bulletin 20 (1988), S. 143-148 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary Poly (styrene-co-divinylbenzene) readily undergoes mercurization with mercuric trifluoroacetate in dichloromethane. The process and extent of mercurization only insignificantly depend on the degree of crosslinking of the polymer containing 1–4 mol.% of the crosslinking agent. By employing this procedure, polymers can be obtained with the mercury content approaching theoretical values. When heated in toluene, mercurized polymers are stable up to 50°C; at higher temperatures they undergo decomposition with splitting of the C-Hg bond. Poly (trifluoroacetoxymercurio)styrene, when reacted with tert-alkyl halides and with alkanes monotopically substituted with the aryl group and bromine, gives the corresponding trifluoroacetates under mild reaction conditions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00256107
    Standort Signatur Erwartet Verfügbarkeit
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  • 99
    Digitale Medien
    Digitale Medien
    Functional polymers. LVI. Photochemical behavior of 2(2-hydroxyphenyl)2H-benzotriazole derivatives (1988)
    Springer
    Polymer bulletin 20 (1988), S. 169-176 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary Introduction of a second benzotriazole unit into 2(2-hydroxyphenyl)2H-benzotriazole structures causes a significant hyperchromic effect on the absorption spectra, the addition of a second hydrogen bonding hydroxyl group causes a small bathochromic shift, but a significant effect on the fluorescence spectrum.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00256111
    Standort Signatur Erwartet Verfügbarkeit
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  • 100
    Digitale Medien
    Digitale Medien
    Properties of urethane elastomers (1988)
    Springer
    Polymer bulletin 20 (1988), S. 195-200 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary The thermally stimulated depolarization currents(TSDC) from polyurethanes based on 4,4′-dibenzyle diisocyanate(DBDI) and both saturated and unsaturated polyesters were studied over the temperature range 240–410 °K. Pour relaxation peaks were observed. The structure of the TSDC thermograms, location and intensity of the constituent peaks depend both on the urethane content and thermal history of the polymerr The morphological structure of the samples was evidenced using electron microscopy method.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00256115
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