An Introduction to Mechanized Reasoning

Mechanized reasoning uses computers to verify proofs and to help discover new theorems. Computer scientists have applied mechanized reasoning to economic problems but -- to date -- this work has not yet been properly presented in economics journals. We introduce mechanized reasoning to economists in three ways. First, we introduce mechanized reasoning in general, describing both the techniques and their successful applications. Second, we explain how mechanized reasoning has been applied to economic problems, concentrating on the two domains that have attracted the most attention: social choice theory and auction theory. Finally, we present a detailed example of mechanized reasoning in practice by means of a proof of Vickrey's familiar theorem on second-price auctions

Twenty years of rewriting logic

AbstractRewriting logic is a simple computational logic that can naturally express both concurrent computation and logical deduction with great generality. This paper provides a gentle, intuitive introduction to its main ideas, as well as a survey of the work that many researchers have carried out over the last twenty years in advancing: (i) its foundations; (ii) its semantic framework and logical framework uses; (iii) its language implementations and its formal tools; and (iv) its many applications to automated deduction, software and hardware specification and verification, security, real-time and cyber-physical systems, probabilistic systems, bioinformatics and chemical systems

Planning the market introduction of new products

In einem zunehmend dynamischen Wettbewerbsumfeld bildet die Fähigkeit zur erfolgreichen Vermarktung von neuen Produkten eine entscheidende Grundlage für den langfristigen Erfolg von Unternehmen. Quantitative Modelle der Verbreitung (Diffusion) von Innovationen in einem sozialen System sind daher sowohl für Wirtschaftswissenschaftler als auch für Manager, die Unterstützung bei der Entwicklung von Markteinführungsstrategien benötigen, von besonderem Interesse. Erste Modelle zur mathematischen Beschreibung von Diffusionsverläufen wurden bereits in den 1960er-Jahren entwickelt. Ziel dieser Modelle ist die empirische Generalisierung von typischen Diffusionsmustern auf aggregierter (d.h. Markt-) Ebene, um den wahrscheinlichen Verlauf der Adoption durch Konsumenten mittels Extrapolation aus frühen Verkaufszahlen abzuschätzen. Für zuverlässige Schätzungen benötigen diese Modelle allerdings Daten über den Großteil des Produktlebenszykluses. Überdies berücksichtigen aggregierte Modelle weder die Heterogenität von Konsumenten noch die Struktur ihrer sozialen Interaktionen. Schließlich eignen sich diese Modelle nur bedingt zur Erprobung des Einflusses von Marketing-Entscheidungsvariablen auf den Diffusionsverlauf. Das Hauptziel dieser Dissertation ist die Entwicklung eines Diffusionsmodells das Entscheidungsträger bei der Planung einer Markteinführungsstrategie für neue Produkte unterstützen kann. Zu diesem Zweck wird agentenbasierte Modellierung und Simulation, eine Methode die in den letzten Jahren in den Sozialwissenschaften zunehmende Verbreitung gefunden hat, eingesetzt. Diese Methode begreift die Diffusion von Innovationen als komplexes emergentes Phänomen, das durch soziale Interaktionen und individuelle Adoptionsentscheidungen von heterogenen Individuen zustande kommt. Ein solcher Bottom-Up-Ansatz ermöglicht es, die prinzipbedingten Einschränkungen von aggregierten Ansätzen zu überwinden und eröffnet damit neue Forschungsmöglichkeiten. Insbesondere können Aspekte wie Adoptionsentscheidungsfaktoren auf Mikroebene, beschränkte Rationalität, unvollständige Information sowie die Heterogenität von Konsumenten hinsichtlich ihrer Präferenzen, ihres Verhaltens und ihrer Verbindungen im sozialen Netzwerk berücksichtigt werden. Die Dissertation zeigt eine Forschungslücke zwischen abstrakten theoretischen Modellen einerseits und angewandten Modellen für bestimmte, sehr spezifische Einsatzbereiche andererseits auf und zielt darauf ab zur Schließung dieser Lücke beizutragen. Der agentenbasierte Ansatz bietet ausgezeichnete Möglichkeiten zur Entwicklung eines generischen und vielseitig einsetzbaren Modells das es erlaubt, aktuelle Forschungsinteressen wie etwa die Diffusion von Innovationen in einem kompetitivem Wettbewerbsumfeld, die räumliche Diffusion von Innovationen oder die Analyse auf Produktebene anstatt auf Branchenebene zu verfolgen. Insbesondere trägt die Dissertation durch (i) die Modellierung aller Stufen des Adoptionsentscheidungsprozesses, (ii) die Erfassung des gesamten Marktes anstatt der Beschränkung auf Erstadoptoren, (iii) die Modellierung der Diffusion einer Innovation in einem Markt mit mehreren Mitbewerbern, (iv) die Erweiterung der zeitlichen Betrachtung von Diffusionsprozessen durch eine räumliche Dimension, (v) die Modellierung eines räumlich definierten sozialen Netzwerkes und (vi) die Einbeziehung von Konsumentenpräferenzen hinsichtlich mehrerer Produktattribute zur Diffusionsforschung bei. Die Eignung des Modells zur Entscheidungsunterstützung in realen Problemstellungen wird anhand eines Anwendungsfalls zur Diffusion eines Biokraftstoffs der zweiten Generation auf dem österreichischen Markt illustriert. Anhand von Simulationsszenarien wird demonstriert, wie das Modell die Planung der Markteinführung einer solchen Innovation unterstützen kann. Ergebnisse zeigen, dass ein wettbewerbsfähiger Preis, wie erwartet, ein wichtiger Adoptionstreiber ist. Zudem weisen die Ergebnisse aber auch darauf hin, dass ein gewisses Marktpotential auch bei einem Preis oberhalb des Niveaus von konventionellen Kraftstoffen besteht. Die Simulation erlaubt potentiellen Investoren die Erprobung unterschiedlicher Strategien zur Auswahl von Vertriebsstellen unter Berücksichtigung von beschränkter Produktionskapazität, lokaler Verfügbarkeit von Rohstoffen und der geographischen Verteilung von Konsumenten. Außerdem ermöglicht es die Simulation, Preisstrategien unter unterschiedlichen Annahmen hinsichtlich zukünftiger Entwicklungen auf dem Rohölmarkt zu testen. Der Anwendungsfall zeigt damit, dass das entwickelte agentenbasierte Diffusionsmodell Entscheidungsträgern wertvolle Unterstützung bei der Entwicklung von Markteinführungsstrategien in einem kompetitiven Marktumfeld bietet.In today’s competitive business environment, firms’ ability to create and maintain competitive advantage and secure long-term survival are critically dependent upon their ability to successful market innovations. Quantitative models of innovation diffusion have therefore attracted strong interest both from management scholars and from practitioners responsible for new product marketing decisions. Pioneering efforts to describe the diffusion of innovations mathematically were made during the 1960s. The aim of these models is to provide empirical generalizations of prototypical diffusion patterns at the aggregate (i.e., market) level in order to estimate the likely diffusion of a new product through extrapolation from early sales; to this end, they typically require considerable amounts of data covering most of the product’s lifespan. Aggregate models cannot account for heterogeneity and social structure and are limited in their potential to evaluate likely effects of decision variables on the diffusion process. The main objective of this thesis is to introduce a diffusion model that can support decision-makers in the process of planning the market introduction of new products. To this end, agent-based modeling and simulation, a methodological innovation that has increasingly been adopted in the social sciences in recent years, is applied to overcome inherent limitations of phenomenological aggregate-level approaches. This bottom-up approach conceives the diffusion of innovations as a complex social phenomenon that emerges from the aggregated individual behavior and the interactions between individuals. It opens up new research opportunities because it can easily incorporate micro-level drivers of adoption, bounded rationality, and imperfect information as well as individuals’ heterogeneity in terms of attributes, preferences, behavior, and linkages in the social network. This thesis identifies and aims at a research gap between purely abstract models of innovation diffusion aimed at general theoretical insights on the one hand, and highly specialized models tailored to a particular practical application on the other hand. The agent-based approach offers excellent opportunities to develop a generic and versatile model that can be applied to a wide range of specific problems. Furthermore, it allows us to pursue cutting-edge research interests including spatial diffusion, diffusion in a competitive context, product-level rather than industry- level analysis, and managerial diagnostics. In particular, the thesis contributes by (i) modeling all stages of the innovation-decision process, (ii) modeling sales rather than exclusively focusing on initial adoption, (iii) modeling the competitive diffusion of multiple products, (iv) complementing the temporal focus with the spatial dimension, (v) incorporating a spatially explicit social network model, and (vi) incorporating multi-attribute consumer decision-making. The capability of the model to tackle real world problems is illustrated by means of a particularly interesting, empirically grounded application study on the diffusion of a second generation biofuel at the Austrian market. Various simulation scenarios demonstrate how the model can be used to plan the market introduction of this innovation. Findings suggest that while a competitive price is unsurprisingly an important driver for adoption, there is a limited market potential for a high quality second generation biofuel at a higher price level than that of conventional fuels. The simulation enables potential investors to assess the effectiveness of various approaches towards selecting gas stations for distribution while accounting for limited production capacity, availability of rich sources of biomass, and the geographic concentration of consumers. It also allows a decision-maker to evaluate the effectiveness of pricing strategies under varying assumptions about future energy market developments. The sample application illustrates how the agent-based model introduced in this thesis can provide managers with valuable decision support in the process of developing product launch strategies in a competitive setting

Library buildings around the world

"Library Buildings around the World" is a survey based on researches of several years. The objective was to gather library buildings on an international level starting with 1990

Hymenoptera Research in the Carpathian Basin (Hymenoptera: Aculeata)

History of the Aculeata research in the Carpathian Basin is discussed. List of species described from the Carpathian Basin and bibliography of the research is provided from 1563 till our present days. Chrysis leachii Schuckard, 1836 is syn. n. of Chrysis hungarica Scopoli, 1770. Pompilus lateritius Mocsáry, 1879 is revocated. Vespa heeriana nom. nov. is proposed as replacement name for Vespa crabroniformis Heer, 1867

Contribution à la gestion de l'évolution des processus métiers

La gestion de l'évolution des processus métier exige une compréhension approfondie des cause des changements, de leurs niveaux d'application ainsi que de leurs impacts sur le reste du système. Dans cette thèse, nous proposons une approche de gestion et de contrôle de l'éolution des processus métier permettant d'analyser ces changements et de comprendre leurs impacts. Cela assistera les concepteurs et les chargés de l'évolution des processus métier à établir une évaluation a priori de l'impact pour réduire les risques et les coûts liés à ces changements et d'améliorer le service et la qualité des processus métier. Ce travail consiste à proposer un ensemble de contributions permettant une vérification de la cohérence et de la conformité des modèles de processus métier après chaque changement, mais aussi d'établir une éaluation a priori de l'impact structurel et qualificatif des modifications. Les différentes approches proposées sont en cours d'expérimentation et de validation à travers le développement d'une plate-forme basée sur l'environnement EclipseThe evolution management of the business processes requires an exhaustive understanding of the change. An evolution engineer needs to understand reasons of a change, its application levels, and subsequently its impact on the whole system. In this thesis, we propose an approach for an a priori change impact analysis, to better control the business process evolution. This may help the business experts and the process designers to evaluate change impact in order to reduce the associated risks and estimate the related costs. It may also help to improve the service and quality of the business processes. This work contributes an eventual improvement, in regard, to verify the coherence and the compliance of the business process models, after each change. It leads to evaluate an a priori change impact analysis in structural and qualitatie aspects. The multiple-perspectives of the proposed approach have been reviewed experimentally. The validation of the approach is evaluated by exteding the Eclipse Development Environment, with the help of a set of plug-ins, as a prototype plate-form.DUNKERQUE-SCD-Bib.electronique (591839901) / SudocSudocFranceF

Simulation Models in eGovernment Using System Dynamics

Doktorgradsavhandling ved Universitetet i Agder, Institutt for infomasjons- og kommunikasjonsteknologi, 2017System Dynamics (SD) is a method to build simulation models using computers, to study the behaviour of systems, and apply what-if scenarios aiming at achieving optimal policy design. In this thesis, we are introducing an SD approach in modelling the eGovernment. The thesis is based on two topics or essays: eParticipation and eAccessibility as examples of eGovernment areas that SD models have not been used in before, to show how SD can be used in modelling and supporting decisions in the field of eGovernment, especially in new areas. Although this research is part of the eGovMon project1 where the use of SD method is indicated, via a literature review we shed light on the mathematical modelling methods commonly used in the eGovernment field, and a comparison between the suitable methods and SD is sketched showing the benefits of and our rationale behind choosing SD. eParticipation aims at linking ordinary people with politics and politicians by making the policymaking process understandable and easy to follow via Information and Communication Technologies. To apply this concept, we were interested in finding a topic of public interest that needs to be highlighted and promoted. Employment policies for Persons with Disabilities (PWD)2 including factors that prevent or promote them to move from welfare recipients to join the labour force in Norway, is such a topic. The employment rate for PWD in Norway is unchanged since 2000, and is not as high as the neighbouring countries, despite the repeated governmental promises. Under this topic, we have administered two questionnaires, one of them towards PWD and another towards potential employers. The PWD questionnaire covered PWD attitudes towards employment in Norway, including information about the factors enabling them to work, encouraging them to take available work opportunities, and preventing them from active job application. Corre-spondingly, the second questionnaire covered the attitudes of employers towards recruiting PWD in Norway, including factors encouraging employers to, and preventing them from recruiting PWD, as well as information related to employers’ awareness of facts about PWD employment. The results were incorporated in an SD model which focuses on enabling PWD to move from welfare to work. The model is intended to be used by policymakers, disability organisations, and individual citizens, and support more targeted discussions among them. Additionally, this model was encapsulated in an Interactive Learning Environment (ILE). To explore how the model could change how its users think and take decisions, the ILE was assessed by an expert opinion poll, and tested with users in two different experiments. 67% of the sample of our expert opinion poll thinks that the ILE achieves its intended goals. Furthermore, 71% of the candidates of both experiments have redefined certain knowledge as a result of using the ILE. eAccessibility of a website refers to the ability of all people to use this website irrespective of their disabilities or the client devices they use to access the Internet. It is an important aspect of websites in general and of public websites in particular. Access to public websites is crucial to assure equal opportunities for all citizens to participate in the society. The government exerts efforts to enhance accessibility, yet there is still room for improvement. Many ways could be proposed to enhance accessibility. However, the impact of selected actions is hard to predict due to diversification and contra-diction, in addition to the continuous change of the system over time. Under this topic, we have analysed questionnaires collected via a couple of surveys on eGovernment measurement methods, in addition to administering another questionnaire and a sample of webpages to classify the Norwegian municipal website accessi-bility failures according to their original causes. Moreover, we have conducted a set of personal interviews with representatives from municipalities. The findings including factors affecting the accessibility of the municipal websites were compiled into an SD model, which is intended to support policymakers’ and website managers’ decisions, and to enhance their mental models. This SD model was also encapsulated in an ILE, which was used in an experiment with users. Results show that 80% of the experiment candidates have redefined certain knowledge as a result of using this ILE

Music and Levels of Narration in Film

This is the first book-length study of the narratology of film music, and an indispensable resource for anyone researching or studying film music or film narratology. It surveys the so far piecemeal discussion of narratological concepts in film music studies, and tries to (cautiously) systematize them, and to expand and refine them with reference to ideas from general narratology and film narratology (including contributions from German-language literature less widely known in Anglophone scholarship). The book goes beyond the current focus of film music studies on the distinction between diegetic and nondiegetic music (music understood to be or not to be part of the storyworld of a film), and takes into account different levels of narration: from the extrafictional to ‘focalizations’ of subjectivity, and music’s many and complex movements between them

Un esquema de programación lógico-funcional con restricciones: marco teórico y aplicación a la depuración declarativa

En este trabajo consideramos dos tipos de errores susceptibles de ser tratados mediante nuestro método de depuración declarativa. En primer lugar, se consideran aquellas respuestas que han sido obtenidas de manera inesperada para un objetivo determinado (respuestas incorrectas). Para este primer caso, proponemos un cálculo de prueba positivo desarrollado a partir de CRWL(D), mediante el que es posible definir los árboles de cómputo como árboles de derivación lógica. En segundo lugar, se considera como un posible error aquel en el que en el conjunto de todas las respuestas obtenidas para un mismo objetivo falte alguna respuesta esperada (respuestas perdidas). En este segundo caso, proponemos otro cálculo denominado cálculo de prueba negativo, en el cual las derivaciones lógicas formalizan la recolección de respuestas computadas y sirven para definir árboles de cómputo aplicables a la diagnosis de respuestas perdidas. Demostramos la corrección lógica de los métodos de diagnosis propuestos, tanto para respuestas incorrectas como para respuestas perdidas, en relación a los sistemas de resolución de objetivos presentados. Finalmente, proponemos la implementación en el sistema TOY de dos posibles herramientas basadas en los métodos de depuración descritos