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  • 1
    Publication Date: 2019
    Description: Within a research project investigating the applicability and performance of modified harvesting heads used during the debarking of coniferous tree species, the actual debarking percentage of processed logs needed to be evaluated. Therefore, a computer-based photo-optical measurement system (Stemsurf) designed to assess the debarking percentage recorded in the field was developed, tested under laboratory conditions, and applied in live field operations. In total, 1720 processed logs of coniferous species from modified harvesting heads were recorded and analyzed within Stemsurf. With a single log image as the input, the overall debarking percentage was calculated by further estimating the un-displayed part of the log surface by defining polygons representing the differently debarked areas of the log surface. To assess the precision and bias of the developed measurement system, 480 images were captured under laboratory conditions on an artificial log with defined surface polygons. Within the laboratory test, the standard deviation of average debarking percentages remained within a 4% variation. A positive bias of 6.7% was caused by distortion and perspective effects. This resulted in an average underestimation of 1.1% for the summer debarking percentages gathered from field operations. The software generally performed as anticipated through field and lab testing and offered a suitable alternative of assessing stem debarking percentage, a task that should increase in importance as more operations are targeting debarked products.
    Electronic ISSN: 2072-4292
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Published by MDPI
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Earth, moon and planets 40 (1988), S. 45-70 
    ISSN: 1573-0794
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Crystal/liquid partition coefficients for Cr, V, Mn, and Fe have been determined experimentally between olivine, orthopyroxene, clinopyroxene and silicate melt possesing the composition of a primitive lunar green glass, at oxygen fugacities appropriate to the lunar interior. These species all behave essentially as compatible elements and possess crystal/liquid partition coefficients mostly between 0.3 and 0.9. Partition coefficients for Cr, V, and Mn are generally similar to those of Fe. This implies that crystal/liquid fractionation processes in the lunar interior which do not involve the participation of spinels would not have been effective in fractionating MnO, CrO, and VO from FeO. The well-known constancy of FeO/MnO ratios in nearly all lunar rocks is a reflection of this behaviour. It is shown that comparably strong correlations between CrO-;FeO and VO-;FeO exist for lunar highland breccias and soils from all sites and that these correlations extend to primitive lunar volcanic glasses associated with mare volcanism, strongly suggesting that the CrO/FeO and VO/FeO ratios so derived are of global importance. The observed ratios characterizing ‘differentiated’ regions of the Moon can be combined with the corresponding ratios for residual refractory portions of the Moon, using measured partition coefficients for Fe, Mg, Cr, V, and Mn between olivine, orthopyroxene and liquid. Bulk Moon abundances for Cr and V have been calculated for a range of reasonable assumptions concerning the petrogenetic relationships between differentiated portions of the Moon and complementary refractory residua consisting of olivine and orthopyroxene mineralogies. Because of the small differences in crystal liquid partition coefficients between FeO, CrO, and VO, these estimates are insensitive to large variations in the models. The bulk Moon is accordingly estimated to contain 2190–2463 ppm Cr and 79–95 ppm V. These values are very similar to the Cr and V contents of the Earth's mantle, estimated as 3010 ppm Cr and 81 ppm V by Sun (1982). The geochemical implications of these similarities are discussed.
    Type of Medium: Electronic Resource
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  • 3
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    Berlin: Deutsches Institut für Wirtschaftsforschung (DIW)
    Publication Date: 2016-05-27
    Description: The increase in municipal economic activity in the utilities sector frequently comes under scrutiny. It is presumed that public utilities have less incentive to provide efficient service than private companies. This could result in excessive costs and prices for end users. New microdata on German energy supply companies allow to conduct an empirical analysis for the whole of Germany for the first time. The findings indicate that there is no difference in efficiency between public and private utilities. This applies to both the competitively structured electricity retail sector and regulated electricity distribution sector. General restructuring in the energy sector such as the increased competitive pressure or the introduction of a more stringent regulatory regime have led to changes in the efficiency of all energy supply companies. The dichotomy between public and private utilities that has been suggested in the (re)municipalization debate therefore appears to be exaggerated.
    Keywords: L94 ; L51 ; L98 ; ddc:330 ; public utilities ; local government ; energy ; efficiency analysis
    Repository Name: EconStor: OA server of the German National Library of Economics - Leibniz Information Centre for Economics
    Language: English
    Type: doc-type:article
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  • 4
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    Berlin: Deutsches Institut für Wirtschaftsforschung (DIW)
    Publication Date: 2016-05-27
    Description: In the 1990s, a number of municipalities started privatizing their energy utilities; in recent years, there has been an intensive debate about whether a paradigm shift has taken place since then. Cities and municipalities have considered putting the energy, water, gas and heat supply back into the hands of public companies; Berlin and Hamburg are two prominent examples. But is there really an overarching trend toward (re)municipalization? According to the present study, which evaluates newly available microdata from official statistics, there is no evidence of a comprehensive (re)municipalization. The increase in public enterprises appears to have more to do with general restructuring in the energy sector, and has in fact been less pronounced than has growth in the private sector.
    Keywords: L32 ; L22 ; L98 ; ddc:330 ; public utilities ; local government ; energy
    Repository Name: EconStor: OA server of the German National Library of Economics - Leibniz Information Centre for Economics
    Language: English
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  • 5
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    Berlin: Deutsches Institut für Wirtschaftsforschung (DIW)
    Publication Date: 2016-02-08
    Description: Mehr als 1600 Verteilnetzbetreiber versorgen deutsche Haushalte mit Strom und Gas. Dabei handelt es sich um »natürliche Monopole«, d.h. es gibt keinen direkten Wettbewerb zwischen den Unternehmen, sondern werden sie durch die Bundesnetzagentur im Anreizregulierungsverfahren reguliert. Herzstück dieses Regulierungsverfahren ist ein Benchmarking beruhend auf der Data Envelopment (DEA) Analysis und der Stochastic Frontier Analysis (SFA). In der wissenschaftlichen Literatur werden Stärken und Schwächen dieser Schätzverfahren diskutiert. Insbesondere jüngere methodische Fortschritte könnten das Benchmarking im Anreizregulierungsverfahren in Zukunft beeinflussen.
    Keywords: ddc:330
    Repository Name: EconStor: OA server of the German National Library of Economics - Leibniz Information Centre for Economics
    Language: German
    Type: doc-type:report
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  • 6
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    ZBW - Deutsche Zentralbibliothek für Wirtschaftswissenschaften, Leibniz-Informationszentrum Wirtschaft
    Publication Date: 2016-01-29
    Description: Energy supply in Germany has undergone considerable changes during the last decade, of which especially the nuclear phase-out and enormous installations of renewable energy sources pose new challenges for conventional combustion technologies. To analyze potential adaption processes due to this changing market conditions, this paper analyzes productivity change and its components in the German electricity and heat generation sector. A unique panel data set of 1555 power plants in Germany between 2003 and 2010 allows to estimate production frontiers for coal, lignite, gas and biomass fired power plants. Production functions are estimated using stochastic non-smooth envelopment of data (StoNED) in a meta-frontier framework. Productivity developments and its components are assessed at quantiles of the input value distributions of the different technologies using a metafrontier Malmquist decomposition. Results indicate (1) a dominant position of gas-fired plants in the metafrontier, (2) productivity changes for all technologies and reductions in production potentials (3) a catch-up for biomass plants to the other technologies.
    Keywords: L94 ; D24 ; C14 ; ddc:330
    Repository Name: EconStor: OA server of the German National Library of Economics - Leibniz Information Centre for Economics
    Language: English
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  • 7
    Publication Date: 2016-06-22
    Description: In this paper, we analyze the technical efficiency of CO2 reduction potentials of German power and heat plants, using a non-parametric sequential Data Envelopment Analysis. We apply a metafrontier framework to evaluate plant-level efficiencies in the transformation of inputs into desirable (energy) and undesirable (CO2 emissions) outputs, taking into account different fossil fuel generation technologies. We dispose of a unique data set for coal-, lignite-, gas- and biomass-fired power plants from 2003 through 2010 that provides an unbalanced panel of 1459 observations. We find intra-group differences within energy generation technology, but natural gas fired power plants clearly have the highest efficiency. Furthermore, the analysis points to significant savings potentials for CO2 and fuel-input.
    Keywords: L94 ; Q50 ; C14 ; ddc:330 ; Electricity Generation ; Non-parametric Efficiency Analysis ; Germany ; Panel 2003-1010
    Repository Name: EconStor: OA server of the German National Library of Economics - Leibniz Information Centre for Economics
    Language: English
    Type: doc-type:workingPaper
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  • 8
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    Berlin: Deutsches Institut für Wirtschaftsforschung (DIW)
    Publication Date: 2016-06-22
    Description: Benchmarking methods are widely used in the regulation of firms in network industries working under heterogeneous exogenous environments. In this paper we compare three recently developed estimators, namely conditional DEA (Daraio and Simar, 2005, 2007b), latent class SFA (Orea and Kumbhakar, 2004; Greene, 2005), and the StoNEZD approach (Johnson and Kuosmanen, 2011) by means of Monte Carlo simulation focusing on their ability to identify production frontiers in the presence of environmental factors. Data generation replicates regulatory data from the energy sector in terms of sample size, sample dispersion and distribution, and correlations of variables. Although results show strengths of each of the three estimators in particular settings, latent class SFA perform best in nearly all simulations. Further, results indicate that the accuracy of the estimators is less sensitive against different distributions of environmental factors, their correlations with inputs, and their impact on the production process, but performance of all approaches deteriorates with increasing noise. For regulators this study provides orientation to adopt new benchmarking methods given industry characteristics.
    Keywords: L50 ; Q50 ; C63 ; ddc:330 ; Monte Carlo Simulation ; Environmental Factors ; StoNEZD ; Latent Class SFA ; Conditional DEA ; Regulatory Benchmarking
    Repository Name: EconStor: OA server of the German National Library of Economics - Leibniz Information Centre for Economics
    Language: English
    Type: doc-type:workingPaper
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  • 9
    Publication Date: 2016-05-27
    Description: Die Ausweitung der kommunalen Wirtschaftstätigkeit in der Energieversorgung wird oftmals kritisch betrachtet. Es wird vermutet, dass öffentliche Unternehmen im Vergleich zu privaten Unternehmen geringeren Anreizen zu effizienter Leistungserstellung unterliegen. Das könnte überhöhte Kosten und Endkundenpreise zur Folge haben. Neue Mikrodaten deutscher Energieversorgungsunternehmen erlauben erstmals eine deutschlandweite empirische Untersuchung. Die Ergebnisse deuten darauf hin, dass es keine Effizienzunterschiede zwischen öffentlichen und privaten Unternehmen gibt. Das gilt sowohl für den wettbewerblich organisierten Stromvertrieb als auch für den regulierten Verteilnetzbetrieb. Allgemeine Umstrukturierungen im Energiesektor wie der erhöhte Wettbewerbsdruck oder verstärkte Regulierungsvorschriften haben zu Effizienzänderungen aller Energieversorgungsunternehmen geführt. Die Dichotomie zwischen öffentlichen und privaten Unternehmen, die in der (Re-)Kommunalisierungsdebatte suggeriert wird, scheint daher übertrieben.
    Description: The increase in municipal economic activity in the utilities sector frequently comes under scrutiny. It is presumed that public utilities have less incentive to provide efficient service than private companies. This could result in excessive costs and prices for end users. New microdata on German energy supply companies allow to conduct an empirical analysis for the whole of Germany for the first time. The findings indicate that there is no difference in efficiency between public and private utilities. This applies to both the competitively structured electricity retail sector and regulated electricity distribution sector. General restructuring in the energy sector such as the increased competitive pressure or the introduction of a more stringent regulatory regime have led to changes in the efficiency of all energy supply companies. The dichotomy between public and private utilities that has been suggested in the (re)municipalization debate therefore appears to be exaggerated.
    Keywords: L94 ; L51 ; L98 ; ddc:330 ; public utilities ; local government ; energy ; efficiency analysis
    Repository Name: EconStor: OA server of the German National Library of Economics - Leibniz Information Centre for Economics
    Language: German
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  • 10
    Publication Date: 2016-05-27
    Description: Nachdem in den 90er Jahren viele Kommunen ihre Energieversorgungsunternehmen privatisiert hatten, ist mittlerweile oft von einem Paradigmenwechsel die Rede. Städte und Gemeinden ziehen demnach in Betracht, die Versorgung mit Strom, Wasser, Gas und Wärme wieder in die Hände öffentlicher Unternehmen zu legen. Die Städte Berlin und Hamburg sind zwei prominente Beispiele dafür. Doch gibt es einen allgemeinen (Re-)Kommunalisierungstrend? Die vorliegende Studie wertet erstmalig verfügbare Mikrodaten der amtlichen Statistik aus und kommt zu dem Schluss: Anhaltspunkte für einen umfassenden (Re-)Kommunalisierungstrend gibt es nicht. Die Zunahme öffentlicher Unternehmen scheint vielmehr auf generelle Umstrukturierungen im Energiesektor zurückzugehen und fällt relativ zum Zuwachs der Privaten geringer aus.
    Description: In the 1990s, a number of municipalities started privatizing their energy utilities; in recent years, there has been an intensive debate about whether a paradigm shift has taken place since then. Cities and municipalities have considered putting the energy, water, gas and heat supply networks back into the hands of public companies; Berlin and Hamburg are two prominent examples. But is there really an overarching trend toward (re)municipalization? According to the present study, which evaluates newly available microdata from official statistics, there is no evidence of a comprehensive (re)municipalization. The increase in public enterprises appears to have more to do with general restructuring in the energy sector, and has in fact been less pronounced than has growth in the private sector.
    Keywords: L32 ; L22 ; L98 ; ddc:330 ; public utilities ; local government ; energy
    Repository Name: EconStor: OA server of the German National Library of Economics - Leibniz Information Centre for Economics
    Language: German
    Type: doc-type:article
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