An (*e-Approximation Scheme for Minimum Variance Resource Allocation Problems

The minimum variance resource allocation problem asks to allocate a given amount of discrete resource to a given set of activities so that the variance of the profits among activities is minimized. The author presents a fully polynomial time approximation scheme for this problem

Winter road maintenance resource allocation models

"June 2010.""A Master's Thesis presented to the Faculty of the Graduate School University of Missouri In Partial Fulfillment of the Requirements for the Degree Master of Science."Thesis supervisor: Dr. Wooseung Jang.Winter snow storms could cause serious disruptions to traffic and transportation. Because resources for winter road maintenance, such as snow removal trucks, are limited, using them properly would improve the efficiency and effectiveness of the winter maintenance work. However, a fixed resource allocation plan among service regions may not work well in several situations because of different types and intensity of winter storms. Therefore, reallocation of resources among service regions is often needed. The objective of this research is to develop a resource reallocation model that minimizes the total cost of reallocation operations and provides equitable resources to service regions. Road and weather condition factors, such as road classes, weather forecasts, and service levels, are taken into account in the model.Includes bibliographical references (pages 64-67)

Fluid Flow Simulation and Optimisation with Lattice Boltzmann Methods on High Performance Computers - Application to the Human Respiratory System

An overall strategy for numerical simulations of the full human respiratory system is introduced. The integrative approach takes advantage of numerical simulation, high performance computing and newly developed mathematical optimisation techniques, all based on a mesoscopic model description and on lattice Boltzmann methods as discretisation strategies. Validated numerical results are presented for the simulation of respirations in a real human lung and nose geometry captured by CT

Essays in structural heuristics

This dissertation introduces and develops a new method of rational reconstruction called structural heuristics. Structural heuristics takes assignment of structure to any given object of investigation as the starting point for its rational reconstruction. This means to look at any given object as a system of relations and of transformation laws for those relations. The operational content of this heuristics can be summarized as follows: when facing any given system the best way to approach it is to explicitly look for a possible structure of it. The utilization of structural heuristics allows structural awareness, which is considered a fundamental epistemic disposition, as well as a fundamental condition for the rational reconstruction of systems of knowledge. In this dissertation, structural heuristics is applied to reconstructing the domain of economic knowledge. This is done by exploring four distinct areas of economic research: (i) economic axiomatics; (ii) realism in economics; (iii) production theory; (iv) economic psychology. The application of structural heuristics to these fields of economic inquiry shows the flexibility and potential of structural heuristics as epistemic tool for theoretical exploration and reconstruction

Techno-Economic and Environmentally Conscious Deconstruction Project Planning and Decision Support (TEE-D-Plan)

Um Bauherren, Planungsingenieure, Rückbauunternehmer und/oder Behörden bei der Identifikation und Definition eines adäquaten Rückbauplans mit Techniken für die einzelnen Vorgänge für ein bestimmtes Rückbauprojekt zu unterstützen, können sogenannte „multi-mode resource-constrained project scheduling problems“ (MRCPSP) für die operative Rückbauplanung eingesetzt werden. Alternative Rückbautechniken der einzelnen Projektvorgänge werden dabei als Modi abgebildet. Die Entscheidungsfindung erfolgt hinsichtlich quantitativer ökonomischer Ziele, wie der Minimierung der direkten Kosten oder der Dauer des Gesamtprojekts. Projektbeschränkungen betreffs ökonomischer Größen, wie maximales Budget und maximale Dauer, und technischer Größen, wie verfügbare Ressourcen, werden als erneuerbare und nicht-erneuerbare Ressourcen modelliert. Lokale Immissionen im Allgemein und deren Minderung im Speziellen sowie Charakteristika des Umfeldes/der Nachbarschaft und deren Veränderungen bleiben in diesen Modellen und bei der Entscheidungsfindung bislang allerdings unberücksichtigt. In der Dissertation wird ein Modell zur technischen, ökonomischen und ökologischen Rückbauplanung und –entscheidungsunterstützung (TEE-D-Plan) entwickelt und angewandt. Durch dieses modulare Modell für die operative Rückbauplanung werden zum ersten Mal lokale Immissionen in Form von Lärm, Staub und Erschütterungen als Zielkriterien in die Entscheidungsfindung integriert. Die Bewertung der technischen Durchführbarkeit von Rückbautechniken wird um Parameter wie die Abbruchhöhe, die am Ende auch die resultierenden Immissionen beeinflusst, ergänzt. Die ökonomische Bewertung einzelner Techniken wird auf Basis von Daten aus der Literatur und Expertenbefragungen aktualisiert und verbessert und durch zwei Testprojekte validiert. Mittels eines Ansatzes der Umweltwirkungsabschätzung und neu erhobenen Primärdaten aus Experimenten und Expertenbefragungen können Lärm-, Staub-, und Erschütterungsimmissionen von Rückbauarbeiten in Form von prozentualen Auslastungen basierend auf der menschlichen Wahrnehmung erstmals quantitativ abgeschätzt werden. Mit Hilfe von TEE-D-Plan werden Projektpläne mit Techniken für einzelne Vorgänge für ein bestimmtes Rückbauprojekt hinsichtlich der Präferenzen des Entscheiders zur Minderung von Immissionen und unter Berücksichtigung der Gesamtprojektdauer und -kosten vorgeschlagen

The exploration of a multi-dimensional safe behaviour model for construction workers in Hong Kong : a structural equation modelling approach

Safety and Health in the workplace has long been the priority work of the Hong Kong administration but the accidentstatistics in Hong Kong tell another story. No matter how sophisticated a safe system is designed, its ultimate success depends very much on the person who carries out the job. Safe behaviour has therefore become the contemporary study of safety and health at work.Since human behaviour is a multidimensional construct, its understanding requires a multiple theory approach. Inspired by this concept, this study explores a Multi-Dimensional Safe Behaviour Model in explaining Construction Workers' Safe Behaviour. The study examines its implication for management when safe behaviours are to be instilled. Nine psychological theories and models, identified under the perspective of the Intrapersonal, Interpersonal and Community Level are examined. A short list of 9 variables of "Social Norm", "Management Commitment", "Safety Knowledge", "Perceived Risk", "Safety Experience", "Self Efficacy"; "Perceived Consequence", "Chance" and Intention to Behave" was constructed. Three hypothetical constructs of "Social Support", "Attitude" and "Expectance" composed of observable indicators from the nine identified variables are also formed. The variables are then put together into a hypothesised Multi-Dimensional Safe Behaviour Model with the casual relationships between variables identified. A Structural Equation Modelling procedure shows that the hypothesised Multi-Dimensional Safe Behaviour Model fits the data reflecting the necessity of adopting a holistic approach in addressing behavioural issues. "Safety Attitude" is found to impose a positive effect on the worker's "Intention to Behave Safely" indirectly via a mediating factor of "Chance Locus". The study conveys practical implications to safety management and researchers. Research limitations and areas for further study are also discussed. Safety behavioural initiatives based on the model testing results in promotion workers' safety behaviours are also addressed

Using a conceptual change approach to improve learners' understanding of ions in aqueous solutions in Physical Sciences.

Magister Educationis - MEd (Mathematics and Science Education)The purpose of this study was to investigate how the use of a conceptual change approach could contribute to enhancing the teaching and learning of ions in aqueous solutions in Grade 10 Physical Science. More specifically, the study attempted to answer the main research question, namely, How can the conceptual change approach be used to teach ions in aqueous solutions in Physical Sciences? This study was underpinned by the theories of constructivism and conceptual change. The concept of effective teaching practice is based on approaches that promote conceptual change and provides learners with skills on learning how to learn and making meaning out of their learning - which is part of the constructivist view of learning. The sample of this research consisted of a single class in a school where the researcher is teaching. The class has 26 learners of mixed gender. The study adopted a single case study approach and was designed to allow for the use of multiple data collection methods. Data was collected through a pre- and post-tests, intervention lessons, classroom observation as well as semi-structured focused group interviews. The use of qualitative and quantitative methods of data collection proved useful and provided in-depth data and allowed for triangulation. The data was analysed both quantitatively and qualitatively. The results of the research showed that learners performed better in the post-test than in the pre-test. The learners mentioned the fact that the intervention lesson played an important role in making them understand the concept better. The results also showed that, while the majority of the learners seemed to have made some progress in their conceptual development as a result of their exposure to the conceptual change method of teaching, others struggled with the approach

Persönliche Wege der Interaktion mit multimedialen Inhalten

Today the world of multimedia is almost completely device- and content-centered. It focuses it’s energy nearly exclusively on technical issues such as computing power, network specifics or content and device characteristics and capabilities. In most multimedia systems, the presentation of multimedia content and the basic controls for playback are main issues. Because of this, a very passive user experience, comparable to that of traditional TV, is most often provided. In the face of recent developments and changes in the realm of multimedia and mass media, this ”traditional” focus seems outdated. The increasing use of multimedia content on mobile devices, along with the continuous growth in the amount and variety of content available, make necessary an urgent re-orientation of this domain. In order to highlight the depth of the increasingly difficult situation faced by users of such systems, it is only logical that these individuals be brought to the center of attention. In this thesis we consider these trends and developments by applying concepts and mechanisms to multimedia systems that were first introduced in the domain of usercentrism. Central to the concept of user-centrism is that devices should provide users with an easy way to access services and applications. Thus, the current challenge is to combine mobility, additional services and easy access in a single and user-centric approach. This thesis presents a framework for introducing and supporting several of the key concepts of user-centrism in multimedia systems. Additionally, a new definition of a user-centric multimedia framework has been developed and implemented. To satisfy the user’s need for mobility and flexibility, our framework makes possible seamless media and service consumption. The main aim of session mobility is to help people cope with the increasing number of different devices in use. Using a mobile agent system, multimedia sessions can be transferred between different devices in a context-sensitive way. The use of the international standard MPEG-21 guarantees extensibility and the integration of content adaptation mechanisms. Furthermore, a concept is presented that will allow for individualized and personalized selection and face the need for finding appropriate content. All of which can be done, using this approach, in an easy and intuitive way. Especially in the realm of television, the demand that such systems cater to the need of the audience is constantly growing. Our approach combines content-filtering methods, state-of-the-art classification techniques and mechanisms well known from the area of information retrieval and text mining. These are all utilized for the generation of recommendations in a promising new way. Additionally, concepts from the area of collaborative tagging systems are also used. An extensive experimental evaluation resulted in several interesting findings and proves the applicability of our approach. In contrast to the ”lean-back” experience of traditional media consumption, interactive media services offer a solution to make possible the active participation of the audience. Thus, we present a concept which enables the use of interactive media services on mobile devices in a personalized way. Finally, a use case for enriching TV with additional content and services demonstrates the feasibility of this concept.Die heutige Welt der Medien und der multimedialen Inhalte ist nahezu ausschließlich inhalts- und geräteorientiert. Im Fokus verschiedener Systeme und Entwicklungen stehen oft primär die Art und Weise der Inhaltspräsentation und technische Spezifika, die meist geräteabhängig sind. Die zunehmende Menge und Vielfalt an multimedialen Inhalten und der verstärkte Einsatz von mobilen Geräten machen ein Umdenken bei der Konzeption von Multimedia Systemen und Frameworks dringend notwendig. Statt an eher starren und passiven Konzepten, wie sie aus dem TV Umfeld bekannt sind, festzuhalten, sollte der Nutzer in den Fokus der multimedialen Konzepte rücken. Um dem Nutzer im Umgang mit dieser immer komplexeren und schwierigen Situation zu helfen, ist ein Umdenken im grundlegenden Paradigma des Medienkonsums notwendig. Durch eine Fokussierung auf den Nutzer kann der beschriebenen Situation entgegengewirkt werden. In der folgenden Arbeit wird auf Konzepte aus dem Bereich Nutzerzentrierung zurückgegriffen, um diese auf den Medienbereich zu übertragen und sie im Sinne einer stärker nutzerspezifischen und nutzerorientierten Ausrichtung einzusetzen. Im Fokus steht hierbei der TV-Bereich, wobei die meisten Konzepte auch auf die allgemeine Mediennutzung übertragbar sind. Im Folgenden wird ein Framework für die Unterstützung der wichtigsten Konzepte der Nutzerzentrierung im Multimedia Bereich vorgestellt. Um dem Trend zur mobilen Mediennutzung Sorge zu tragen, ermöglicht das vorgestellte Framework die Nutzung von multimedialen Diensten und Inhalten auf und über die Grenzen verschiedener Geräte und Netzwerke hinweg (Session mobility). Durch die Nutzung einer mobilen Agentenplattform in Kombination mit dem MPEG-21 Standard konnte ein neuer und flexibel erweiterbarer Ansatz zur Mobilität von Benutzungssitzungen realisiert werden. Im Zusammenhang mit der stetig wachsenden Menge an Inhalten und Diensten stellt diese Arbeit ein Konzept zur einfachen und individualisierten Selektion und dem Auffinden von interessanten Inhalten und Diensten in einer kontextspezifischen Weise vor. Hierbei werden Konzepte und Methoden des inhaltsbasierten Filterns, aktuelle Klassifikationsmechanismen und Methoden aus dem Bereich des ”Textminings” in neuer Art und Weise in einem Multimedia Empfehlungssystem eingesetzt. Zusätzlich sind Methoden des Web 2.0 in eine als Tag-basierte kollaborative Komponente integriert. In einer umfassenden Evaluation wurde sowohl die Umsetzbarkeit als auch der Mehrwert dieser Komponente demonstriert. Eine aktivere Beteiligung im Medienkonsum ermöglicht unsere iTV Komponente. Sie unterstützt das Anbieten und die Nutzung von interaktiven Diensten, begleitend zum Medienkonsum, auf mobilen Geräten. Basierend auf einem Szenario zur Anreicherung von TV Sendungen um interaktive Dienste konnte die Umsetzbarkeit dieses Konzepts demonstriert werden