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  • Science  (16)
  • thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TB Technology: general issues  (5)
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  • Logos Verlag Berlin  (18)
  • English  (18)
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  • 1
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    Logos Verlag Berlin | Logos Verlag Berlin
    Publication Date: 2024-04-11
    Description: While binaural technology applications gained in popularity in recent years, the majority of applications still use non-individual Head-Related Transfer Functions (HRTFs) from artificial heads. However, certain applications, for example research of spatial hearing or hearing attention, require an physically exact and realistic binaural signal. The limiting factor that prohibits the widespread use of individual HRTFs is the acquisition time of such data. This time requirement has recently been reduced by the use of parallelization in the measurement signal which lead to the development of fast measurement systems capable of acquiring individual and spatially dense HRTF. This thesis provides a objective and subjective evaluation of such a system that is designed with the goal of little disturbance of the measurements in mind. The construction is detailed, followed by both an objective and subjective evaluation. A detailed investigation into additional distortion of the sound field introduced by the system itself is presented and it is shown that the system performs comparably to a conventional system in terms of sound source localization. Furthermore, a method is introduced and evaluated to further reduce the measurement time by using continuous rotation during the measurement. This method is used to reduced the measurement duration from eight minutes to three minutes without audible differences.
    Keywords: Technology & Engineering ; Electronics ; Science ; Physics ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TJ Electronics and communications engineering::TJF Electronics engineering ; thema EDItEUR::P Mathematics and Science::PH Physics
    Language: English
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  • 2
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    Logos Verlag Berlin | Logos Verlag Berlin
    Publication Date: 2024-04-04
    Description: Listeners with hearing impairments have difficulties understanding speech in the presence of background noise. Although prosthetic devices such as hearing aids and cochlear implants may improve the hearing capability, listeners with hearing impairments still complain about their speech perception in the presence of noise. The basic tonal audiometry only gives a cursory idea of the degree of difficulty in spoken communication caused by hearing loss because it does not assess the ability to understand speech. Therefore, the use of speech-in-noise tests to measure hearing loss in complex scenes is an integral part of a patient's audiological study. Most research has concentrated on studying only stationary sound sources, but in natural acoustic scenes, conversations may become very difficult to understand in the presence of moving sound sources such as a moving talker or a passing vehicle. Therefore, this thesis deals with quantifying speech perception in the presence of moving maskers through virtual sound sources presented binaurally via headphones. Significant differences in several conditions were found, revealing that the auditory system assesses differently the moving maskers than the stationary maskers. Therefore, the inclusion of moving conditions in clinical listening tests is recommended, in order to assess speech-in-noise perception in a more realistic environment.
    Keywords: Science ; thema EDItEUR::P Mathematics and Science::PD Science: general issues
    Language: English
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  • 3
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    Logos Verlag Berlin | Logos Verlag Berlin
    Publication Date: 2024-04-04
    Description: Die Teilchenphysik als Teilgebiet der modernen Physik gewinnt zunehmend an Bedeutung im schulischen Physikunterricht. In dieser Arbeit wird erstmalig das von Lehrkräften benötigte Fachwissen zur Teilchenphysik modelliert, wobei Fachwissen als ein Teil des Professionswissens verstanden wird. Als Fachwissensdimensionen werden die Inhaltsbereiche und die Wissensarten in den Fokus genommen, für welche jeweils Subfacetten identifiziert und präzise beschrieben werden. Nach einem überblick über die wesentlichen Ideen der Teilchenphysik wird in der Arbeit die sukzessive Modellierung des Fachwissens im Rahmen einer qualitativ und quantitativ angelegten Delphi-Studie vorgestellt. In drei Befragungsrunden wurden zwischen 35 und 65 internationale Expertinnen und Experten aus der teilchenphysikbezogenen Forschung (Fachwissenschaft und Fachdidaktik) und öffentlichkeitsarbeit (u.a. Wissenschaftsjournalismus) sowie erfahrene Lehrkräfte zu den für das Fachwissen relevanten Themen der Teilchenphysik befragt. Empirische Analysen der Befragungsrunden ergaben, dass sich die Dimension Inhaltsbereiche im deklarativen Wissen aus zehn teilchenphysikalischen Themen (z.B. Teilchen in der Hochenergiephysik, die vier fundamentalen Wechselwirkungen) zusammensetzt, von welchen sechs als besonders relevant eingeschätzt wurden. Im Anschluss an die letzte Befragungsrunde wurde theoriegeleitet eine erste Modellierung der Inhaltsbereiche für die Wissensarten des prozeduralen und konditionalen Wissens vorgenommen.
    Keywords: Science ; Education ; Science ; Physics ; thema EDItEUR::P Mathematics and Science::PD Science: general issues ; thema EDItEUR::J Society and Social Sciences::JN Education ; thema EDItEUR::P Mathematics and Science::PH Physics
    Language: English
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  • 4
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    Logos Verlag Berlin | Logos Verlag Berlin
    Publication Date: 2024-04-11
    Description: Our world today is becoming increasingly complex, and technical devices are getting ever smaller and more powerful. The high density of electronic components together with high clock frequencies leads to unwanted side-effects like crosstalk, delayed signals and substrate noise, which are no longer negligible in chip design and can only insufficiently be represented by simple lumped circuit models. As a result, different physical phenomena have to be taken into consideration since they have an increasing influence on the signal propagation in integrated circuits. Computer-based simulation methods play thereby a key role. The modelling and analysis of complex multi-physics problems typically leads to coupled systems of partial differential equations and differential-algebraic equations (DAEs). Dynamic iteration and model order reduction are two numerical tools for efficient and fast simulation of coupled systems. Formodelling of low frequency electromagnetic field, we use magneto-quasistatic (MQS) systems which can be considered as an approximation to Maxwells equations. A spatial discretization by using the finite element method leads to a DAE system. We analyze the structural and physical properties of this system and develop passivity-preserving model reduction methods. A special block structure of the MQS model is exploited to to improve the performance of the model reduction algorithms.
    Keywords: Technology & Engineering ; Electronics ; Mathematics ; Science ; Physics ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TJ Electronics and communications engineering::TJF Electronics engineering ; thema EDItEUR::P Mathematics and Science::PB Mathematics ; thema EDItEUR::P Mathematics and Science::PH Physics
    Language: English
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  • 5
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    Logos Verlag Berlin | Logos Verlag Berlin
    Publication Date: 2024-04-11
    Description: The aim of the present thesis is to examine the cognitive control mechanisms underlying auditory selective attention by considering the influence of variables that increase the complexity of an auditory scene. Therefore, technical aspects such as dynamic binaural hearing, room acoustics and head movements as well as those that influence the efficiency of cognitive processing are taken into account. Step-by-step the well-established dichotic-listening paradigm is extended into a realistic spatial listening paradigm. Conducted empirical surveys are based on a paradigm examining the intentional switching of auditory selective attention. Performance measure differences between the repetition of the target's spatial position and the related switch describe the loss of efficiency associated with redirecting attention from one target's location to another. To examine whether the irrelevant auditory information is decoded, interference in the processing of task-relevant and task-irrelevant information is created in the paradigm. Using the binaural-listening paradigm, the ability to intentionally switch auditory selective attention is tested when applying different methods of spatial reproduction. Essential differences between real sources, an individual and a non-individual binaural synthesis are found. As a step towards multi-talker scenarios in realistic environments participants are tested in differently reverberating environments, resulting in highly affected switch costs. Age-related effects are found when applying the binaural-listening paradigm, indicating difficulties for elderly to suppress processing the distractor's speech.
    Keywords: Technology & Engineering ; Electronics ; Technology & Engineering ; Psychology ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TJ Electronics and communications engineering::TJF Electronics engineering ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TB Technology: general issues ; thema EDItEUR::J Society and Social Sciences::JM Psychology
    Language: English
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  • 6
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    Logos Verlag Berlin | Logos Verlag Berlin
    Publication Date: 2024-04-05
    Description: In 2005, the hybrid model was published by Prof. H.-D. Alber and Prof. P. Zhu as an alternative to the Allen-Cahn model for the description of phase field transformations. With low interfacial energy, it is more efficient, since the resolution of the diffuse interface is numerically broader for the same solution accuracy and allows coarser meshing. The solutions of both models are associated with energy minimisation and in this work the error terms introduced in the earlier publications are discussed and documented using one and two dimensional numerical simulations. In the last part of this book, phase field problems, initially not coupled with material equations, are combined with linear elasticity and, after simple introductory examples, a growing martensitic inclusion is simulated and compared with literature data. In addition to the confirmed numerical advantage, another phenomenon not previously described in the literature is found: with the hybrid model, in contrast to the examples calculated with the Allen-Cahn model, an inclusion driven mainly by curvature energy does not disappear completely. The opposite problem prevents inclusions from growing from very small initial configurations, but this fact can be remedied by a very finely chosen diffuse interface width and by analysing and adjusting the terms that generate the modelling errors. The last example shows that the hybrid model can be used with numerical advantages despite the above mentioned peculiarities.
    Keywords: Science ; Chemistry ; Mathematics ; Science ; Physics ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::P Mathematics and Science::PB Mathematics ; thema EDItEUR::P Mathematics and Science::PH Physics
    Language: English
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  • 7
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    Logos Verlag Berlin | Logos Verlag Berlin
    Publication Date: 2024-04-04
    Description: To better understand the ancient Nabataean capital of Petra, it is important to consider its rural surroundings as well. The city's unfavorable geostrategic location makes this already clear: Situated in a deep valley and flanked by high mountain ranges, Petra's urban development was only possible through a well-structured organization of its surrounding landscape. This study presents a first comprehensive archaeological and culture-historical characterization of the Petraean hinterland and researches overall strategies of the spatial organization of the city's rural environs. Based on an extensive set of archaeological survey data from the Petra region, this study explores a variety of archaeological site types and features diachronically. While the main chronological focus is clearly set on the Nabataean and Roman periods, it also considers the preceding Iron Age and Hellenistic periods, as well as the subsequent Byzantine period. The aim is to examine rural settlement patterns and subsistence strategies, aspects of rural water management, the extensive infrastructural network, the funerary and religious landscape, the military disposition, as well as the industrial potential of rural Petra. Following a unique landscape archaeological approach, this study provides a differentiated analysis of the various archaeological sites and features for a broad, regional understanding of the Petraean hinterland and offers new insights into the socio-political and administrative, military, economic and infrastructural development of Terra Petraea through time. Um die antike Nabatäerhauptstadt, Petra, besser verstehen zu können, muss man auch das Umland der Stadt in Betracht ziehen. Allein die geostrategisch ungünstige Lage Petras macht dies schon deutlich: In einem tiefen Tal gelegen und umgeben von steilen Gebirgsketten, war die Entwicklung der Stadt nur durch eine gut funktionierende Organisation der umliegenden Landschaft möglich. Diese Arbeit untersucht diesen Aspekt näher und legt eine erste, umfassende archäologische und kulturhistorische Charakterisierung des Umlandes von Petra vor und erforscht allgemeine Strategien zur räumlichen Organisation des peträischen Hinterlandes. Sie stützt sich dabei auf extensive archäologische Surveydaten aus der Petra-Region und untersucht eine Vielzahl von archäologischen Fundstellen und Gattungen diachron. Der chronologische Schwerpunkt liegt eindeutig auf der nabatäischen und römischen Periode. Es werden aber auch die vorangehende eisenzeitliche und hellenistische Periode sowie die nachfolgende byzantinische Zeit berücksichtigt. Ziel ist es, ländliche Siedlungsmuster und Subsistenzstrategien, Aspekte des ländlichen Wassermanagements, das infrastrukturelle Netzwerk, die funeräre und religiöse Landschaft, die militärische Disposition sowie das industrielle Potential des peträischen Umlandes zu untersuchen. Mit einem bisher einzigartigen landschaftsarchäologischen Ansatz, bietet diese Arbeit eine differenzierte Analyse der archäologischen Daten, um ein breites Verständnis der räumlichen Organisation des peträischen Hinterlandes zu ermäglichen. Es sollen dabei neue Erkenntnisse in die sozio-politische und administrative, militärische, wirtschaftliche und infrastrukturelle Entwicklung der Terra Petraea im Laufe der Zeit geboten werden.
    Keywords: Social Science ; Archaeology ; Science ; Earth Sciences ; Geography ; Science ; Earth Sciences ; thema EDItEUR::N History and Archaeology::NK Archaeology ; thema EDItEUR::R Earth Sciences, Geography, Environment, Planning::RG Geography ; thema EDItEUR::R Earth Sciences, Geography, Environment, Planning::RB Earth sciences
    Language: English
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  • 8
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    Logos Verlag Berlin | Logos Verlag Berlin
    Publication Date: 2024-04-04
    Description: In August 2022, researchers and developers from Armenia, Chile, Germany, and Japan met at the American University of Armenia for the third edition of the CODASSCA Workshop on Collaborative Technologies and Data Science in Smart City Applications, co-organized with a Summer School on Artificial Neural Networks and Deep Learning. This book presents their contributions on intelligent technologies in data science and human-centered computing.
    Keywords: Mathematics ; Computers ; Computer Science ; Technology & Engineering ; thema EDItEUR::P Mathematics and Science::PB Mathematics ; thema EDItEUR::U Computing and Information Technology::UY Computer science ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TB Technology: general issues
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  • 9
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    Logos Verlag Berlin | Logos Verlag Berlin
    Publication Date: 2024-04-04
    Description: The main focus of this thesis is the discussion of stability of an objective (atomic) structure consisting of single atoms which interact via a potential. We define atomistic stability using a second derivative test. More precisely, atomistic stability is equivalent to a vanishing first derivative of the configurational energy (at the corresponding point) and the coerciveness of the second derivative of the configurational energy with respect to an appropriate semi-norm. Atomistic stability of a lattice is well understood, see, e.,g., [40]. The aim of this thesis is to generalize the theory to objective structures. In particular, we first investigate discrete subgroups of the Euclidean group, then define an appropriate seminorm and the atomistic stability for a given objective structure, and finally provide an efficient algorithm to check its atomistic stability. The algorithm particularly checks the validity of the Cauchy-Born rule for objective structures. To illustrate our results, we prove numerically the stability of a carbon nanotube by applying the algorithm.
    Keywords: Mathematics ; Science ; Physics ; thema EDItEUR::P Mathematics and Science::PB Mathematics ; thema EDItEUR::P Mathematics and Science::PH Physics
    Language: English
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  • 10
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    Logos Verlag Berlin | Logos Verlag Berlin
    Publication Date: 2024-04-04
    Description: Digitalisation, digital networks, and artificial intelligence are fundamentally changing our lives! We must understand the various developments and assess how they interact and how they affect our regular, analogue lives. What are the consequences of such changes for me personally and for our society? Digital networks and artificial intelligence are seminal innovations that are going to permeate all areas of society and trigger a comprehensive, disruptive structural change that will evoke numerous new advances in research and development in the coming years. Even though there are numerous books on this subject matter, most of them cover only specific aspects of the profound and multifaceted effects of the digital transformation. An overarching assessment is missing. In 2016, the Federation of German Scientists (VDW) has founded a study group to assess the technological impacts of digitalisation holistically. Now we present this compendium to you. We address the interrelations and feedbacks of digital innovation on policy, law, economics, science, and society from various scientific perspectives. Please consider this book as an invitation to contemplate with other people and with us, what kind of world we want to live in!
    Keywords: Science ; Computers ; Computer Science ; Philosophy ; thema EDItEUR::P Mathematics and Science::PD Science: general issues ; thema EDItEUR::U Computing and Information Technology::UY Computer science ; thema EDItEUR::Q Philosophy and Religion::QD Philosophy
    Language: English
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  • 11
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    Logos Verlag Berlin | Logos Verlag Berlin
    Publication Date: 2024-04-04
    Description: Die Teilchenphysik als Teilgebiet der modernen Physik gewinnt zunehmend an Bedeutung im schulischen Physikunterricht. In dieser Arbeit wird erstmalig das von Lehrkräften benötigte Fachwissen zur Teilchenphysik modelliert, wobei Fachwissen als ein Teil des Professionswissens verstanden wird. Als Fachwissensdimensionen werden die Inhaltsbereiche und die Wissensarten in den Fokus genommen, für welche jeweils Subfacetten identifiziert und präzise beschrieben werden. Nach einem überblick über die wesentlichen Ideen der Teilchenphysik wird in der Arbeit die sukzessive Modellierung des Fachwissens im Rahmen einer qualitativ und quantitativ angelegten Delphi-Studie vorgestellt. In drei Befragungsrunden wurden zwischen 35 und 65 internationale Expertinnen und Experten aus der teilchenphysikbezogenen Forschung (Fachwissenschaft und Fachdidaktik) und öffentlichkeitsarbeit (u.a. Wissenschaftsjournalismus) sowie erfahrene Lehrkräfte zu den für das Fachwissen relevanten Themen der Teilchenphysik befragt. Empirische Analysen der Befragungsrunden ergaben, dass sich die Dimension Inhaltsbereiche im deklarativen Wissen aus zehn teilchenphysikalischen Themen (z.B. Teilchen in der Hochenergiephysik, die vier fundamentalen Wechselwirkungen) zusammensetzt, von welchen sechs als besonders relevant eingeschätzt wurden. Im Anschluss an die letzte Befragungsrunde wurde theoriegeleitet eine erste Modellierung der Inhaltsbereiche für die Wissensarten des prozeduralen und konditionalen Wissens vorgenommen.
    Keywords: Science ; Education ; Science ; Physics ; thema EDItEUR::P Mathematics and Science::PD Science: general issues ; thema EDItEUR::J Society and Social Sciences::JN Education ; thema EDItEUR::P Mathematics and Science::PH Physics
    Language: English
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  • 12
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    Logos Verlag Berlin | Logos Verlag Berlin
    Publication Date: 2024-04-04
    Description: Sound power describes the emission of sound from sound sources. Despite today's state-of-the art measurement techniques, the current sound power determination methods are restricted due to various limitations. To overcome these limitations, a new sound power determination method is proposed, aiming at the establishment of traceability in airborne sound. This will enable the characterization of a sound source by its free field sound power. The dissertation describes a study on the dissemination process, which will allow the sound power of a device under test located at a real surrounding environment, to be referred to its free field sound power. Apart from the sound power, the corresponding uncertainty may be estimated in a transparent way, where each uncertainty component is provided. The basic tool for the dissemination process is the substitution method using aerodynamic reference sound sources, applied to both sound pressure and sound intensity measurements. Initially, a theoretical investigation deals with the factors that influence the substitution method. Experimental results are then presented based on measurements using a specially designed scanning apparatus. The transition from calibration to in situ conditions and the required correction, due to changes in environmental and operational conditions, is then discussed. In the last section, the sound power level of devices under test is determined along with its related uncertainty, which is further compared to the up-to-date uncertainty values.
    Keywords: Science ; Physics ; bic Book Industry Communication::P Mathematics & science::PH Physics ; thema EDItEUR::P Mathematics and Science::PH Physics
    Language: English
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  • 13
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    Logos Verlag Berlin | Logos Verlag Berlin
    Publication Date: 2024-04-04
    Description: To better understand the ancient Nabataean capital of Petra, it is important to consider its rural surroundings as well. The city's unfavorable geostrategic location makes this already clear: Situated in a deep valley and flanked by high mountain ranges, Petra's urban development was only possible through a well-structured organization of its surrounding landscape. This study presents a first comprehensive archaeological and culture-historical characterization of the Petraean hinterland and researches overall strategies of the spatial organization of the city's rural environs. Based on an extensive set of archaeological survey data from the Petra region, this study explores a variety of archaeological site types and features diachronically. While the main chronological focus is clearly set on the Nabataean and Roman periods, it also considers the preceding Iron Age and Hellenistic periods, as well as the subsequent Byzantine period. The aim is to examine rural settlement patterns and subsistence strategies, aspects of rural water management, the extensive infrastructural network, the funerary and religious landscape, the military disposition, as well as the industrial potential of rural Petra. Following a unique landscape archaeological approach, this study provides a differentiated analysis of the various archaeological sites and features for a broad, regional understanding of the Petraean hinterland and offers new insights into the socio-political and administrative, military, economic and infrastructural development of Terra Petraea through time. Um die antike Nabatäerhauptstadt, Petra, besser verstehen zu können, muss man auch das Umland der Stadt in Betracht ziehen. Allein die geostrategisch ungünstige Lage Petras macht dies schon deutlich: In einem tiefen Tal gelegen und umgeben von steilen Gebirgsketten, war die Entwicklung der Stadt nur durch eine gut funktionierende Organisation der umliegenden Landschaft möglich. Diese Arbeit untersucht diesen Aspekt näher und legt eine erste, umfassende archäologische und kulturhistorische Charakterisierung des Umlandes von Petra vor und erforscht allgemeine Strategien zur räumlichen Organisation des peträischen Hinterlandes. Sie stützt sich dabei auf extensive archäologische Surveydaten aus der Petra-Region und untersucht eine Vielzahl von archäologischen Fundstellen und Gattungen diachron. Der chronologische Schwerpunkt liegt eindeutig auf der nabatäischen und römischen Periode. Es werden aber auch die vorangehende eisenzeitliche und hellenistische Periode sowie die nachfolgende byzantinische Zeit berücksichtigt. Ziel ist es, ländliche Siedlungsmuster und Subsistenzstrategien, Aspekte des ländlichen Wassermanagements, das infrastrukturelle Netzwerk, die funeräre und religiöse Landschaft, die militärische Disposition sowie das industrielle Potential des peträischen Umlandes zu untersuchen. Mit einem bisher einzigartigen landschaftsarchäologischen Ansatz, bietet diese Arbeit eine differenzierte Analyse der archäologischen Daten, um ein breites Verständnis der räumlichen Organisation des peträischen Hinterlandes zu ermäglichen. Es sollen dabei neue Erkenntnisse in die sozio-politische und administrative, militärische, wirtschaftliche und infrastrukturelle Entwicklung der Terra Petraea im Laufe der Zeit geboten werden.
    Keywords: Social Science ; Archaeology ; Science ; Earth Sciences ; Geography ; Science ; Earth Sciences ; thema EDItEUR::N History and Archaeology::NK Archaeology ; thema EDItEUR::R Earth Sciences, Geography, Environment, Planning::RG Geography ; thema EDItEUR::R Earth Sciences, Geography, Environment, Planning::RB Earth sciences
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  • 14
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    Logos Verlag Berlin | Logos Verlag Berlin
    Publication Date: 2024-04-11
    Description: Human sound localization helps to pay attention to spatially separated speakers using interaural level and time differences as well as angle-dependent monaural spectral cues. In a monophonic teleconference, for instance, it is much more difficult to distinguish between different speakers due to missing binaural cues. Spatial positioning of the speakers by means of binaural reproduction methods using head-related transfer functions (HRTFs) enhances speech comprehension. These HRTFs are influenced by the torso, head and ear geometry as they describe the propagation path of the sound from a source to the ear canal entrance. Through this geometry-dependency, the HRTF is directional and subject-dependent. To enable a sufficient reproduction, individual HRTFs should be used. However, it is tremendously difficult to measure these HRTFs. For this reason this thesis proposes approaches to adapt the HRTFs applying individual anthropometric dimensions of a user. Since localization at low frequencies is mainly influenced by the interaural time difference, two models to adapt this difference are developed and compared with existing models. Furthermore, two approaches to adapt the spectral cues at higher frequencies are studied, improved and compared. Although the localization performance with individualized HRTFs is slightly worse than with individual HRTFs, it is nevertheless still better than with non-individual HRTFs, taking into account the measurement effort.
    Keywords: Technology & Engineering ; Electronics ; Science ; Physics ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TJ Electronics and communications engineering::TJF Electronics engineering ; thema EDItEUR::P Mathematics and Science::PH Physics
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  • 15
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    Logos Verlag Berlin | Logos Verlag Berlin
    Publication Date: 2024-04-14
    Description: The exchange of orbit information is becoming more important in view of the increasing population of objects in space as well as the increase in parties involved in space operations. The aim of this thesis was to investigate how orbit information maintained by a space surveillance system can be provided to its users. Services like collision avoidance require very accurate information, while other services might be less stringent. An approach was studied, which allows to derive orbit and covariance information of predetermined accuracy from a reference orbit. Using Chebyshev polynomials, continuous state vector and covariance matrix information can be provided. The major advantage is that no inter- or extrapolation on the user's side is required. A method to reduce the data amount by interpolating the variance envelope functions was also studied. The proposed method in this thesis gives access to highly accurate information from the catalogue, where this information is required. On the other hand it can also provide less accurate information, where requirements are less restrictive, thereby allowing for a significantly reduced amount of data to be transferred and stored.
    Keywords: Computers ; Computer Science ; Technology & Engineering ; Science ; Physics ; thema EDItEUR::U Computing and Information Technology::UY Computer science ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TB Technology: general issues ; thema EDItEUR::P Mathematics and Science::PH Physics
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  • 16
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    Logos Verlag Berlin | Logos Verlag Berlin
    Publication Date: 2024-04-14
    Description: Orbital debris is becoming an increasing problem for space flight missions. New satellite launches, explosions, collisions and other events cause a steady rise in the number of objects orbiting the Earth. It is therefore important to determine the future development of the object population, as well as the effectiveness of debris mitigation measures, in long-term simulations. Orbital propagation, the calculation of an object's movement in its orbit, poses a challenge for this research due to the high computation times of the complex perturbation models involved. With populations consisting of hundreds of thousands of objects as well as simulation time frames of up to 200 years, these calculations can take up hours of computation time. To speed up this process, the analytical propagator Ikebana is introduced in this work of applied computer science in engineering. The program runs on graphics processing units, hardware designed for massively parallel execution of up to thousands of concurrent threads. This reduces the overall run time for large object populations from hours to minutes. Porting software from a conventional CPU is not a trivial task and involves a number of potential pitfalls and optimization opportunities which are detailed in this work. The propagator is integrated into other applications via a generic, multi-platform interface specifically designed for this task. It allows to develop the propagator separately and integrate it into other tools as a plugin at run time. The interface's architecture serves as a design template for analytical propagation software.
    Keywords: Computers ; Computer Science ; Technology & Engineering ; Science ; Physics ; thema EDItEUR::U Computing and Information Technology::UY Computer science ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TB Technology: general issues ; thema EDItEUR::P Mathematics and Science::PH Physics
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  • 17
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    Logos Verlag Berlin | Logos Verlag Berlin
    Publication Date: 2024-04-05
    Description: The field of psychiatry changed dramatically in the latter half of the nineteenth century, largely by embracing science. The transformation was most evident in Germany, where many psychiatrists began to work concurrently in the clinic and the laboratory. Some researchers sought to discover brain correlates of mental illness, while others looked to experimental psychology for insights into mental dynamics. Featured here, are the lives and works of Emil Kraepelin - often considered the founder of modern scientific psychiatry, his teacher Bernhard Gudden, and his anatomist colleague Franz Nissl. The book describes scientific findings together with the methods used; it explains why diagnoses were then (and are still now) so difficult to make; it also explores mind-brain controversies. The Making of Modern Psychiatry will inform and delight mental health professionals as well as all persons curious about the origins of modern psychiatry.
    Keywords: Science ; Life Sciences ; Biology ; Psychology ; Technology & Engineering ; Agriculture ; thema EDItEUR::P Mathematics and Science::PS Biology, life sciences ; thema EDItEUR::J Society and Social Sciences::JM Psychology ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TV Agriculture and farming
    Language: English
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    Logos Verlag Berlin | Logos Verlag Berlin
    Publication Date: 2024-04-05
    Description: When auralizing moving sound sources in Virtual Reality (VR) environments, the two main input parameters are the location and radiated signal of the source. An array measurement-based model is developed to characterize moving sound sources regarding the two parameters in this thesis. This model utilizes beamforming, i.e. delay and sum beamforming (DSB) and compressive beamforming (CB) to obtain the locations and signals of moving sound sources. A spiral and a pseudorandom microphone array are designed for DSB and CB, respectively, to yield good localization ability and meet the requirement of CB. The de-Dopplerization technique is incorporated in the time-domain DSB to address moving source problems. Time-domain transfer functions (TDTFs) are calculated in terms of the spatial locations within the steering window of the moving source. TDTFs then form the sensing matrix of CB, thus allowing CB to solve moving source problem. DSB and CB are further extended to localize moving sound sources, and the reconstructed signals from the beamforming outputs are investigated to obtain the source signals. Moreover, localization and signal reconstruction are evaluated through varying parameters in the beamforming procedures, i.e. steering position, steering window length and source speed for a moving periodic signal using DSB, and regularization parameter, signal to noise ratio (SNR), steering window length, source speed, array to source motion trajectory and mismatch for a moving engine signal using CB. The parameter studies show guidelines of parameter selection based on the given situations in this thesis for modeling moving source using beamforming. Both algorithms are able to reconstruct the moving signals in the given scenarios. Although CB outperforms DSB in terms of signal reconstruction under particular conditions, the localization abilities of the two algorithms are quite similar. The practicability of the model has been applied on pass-by measurements of a moving loudspeaker using the designed arrays, and the results can match the conclusions drawn above from simulations. Finally, a framework on how to apply the model for moving source auralization is proposed.
    Keywords: Science ; Chemistry ; Technology & Engineering ; Construction ; Technology & Engineering ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TN Civil engineering, surveying and building::TNK Building construction and materials ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TB Technology: general issues
    Language: English
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