1,720,970 research outputs found
Learning and clustering of fuzzy cognitive maps for travel behaviour analysis
No full textIn modern society, more and more attention is given to the increase in public transportation or bike use. In this regard, one of the most important issues is to find and analyse the factors influencing car dependency and the attitudes of people in terms of preferred transport mode. Although the individuals’ transport behavioural modelling is a complex task, it has a notable social and economic impact. Thus, in this paper, fuzzy cognitive maps are explored to represent the behaviour and operation of such complex systems. This soft-computing technique allows modelling how the travellers make decisions based on their knowledge of different transport modes properties at different levels of abstraction. These levels correspond to the hierarchy perception including different scenarios of travelling, different benefits of choosing a specific travel mode, and different situations and attributes related to those benefits. We use learning and clustering of fuzzy cognitive maps to describe travellers’ behaviour and change trends in different abstraction levels. Cluster estimations are done before and after the learning of the maps, in order to compare people’s way of thinking if only considering an initial view of a transport mode decision for a daily activity, and when they really have a deeper reasoning process in view of benefits and consequences. The results of this study will help transportation policy decision makers in better understanding of people’s needs and consequently will help them actualizing different policy formulations and implementations
Tackling Travel Behaviour: An approach based on Fuzzy Cognitive Maps
No full textAbstract Although the individuals' transport behavioural modelling is a complex task, it can produce a notable social and economic impact. In this paper, Fuzzy Cognitive Maps are explored to represent the behaviour and operation of such complex systems. An automatic approach to extract mental representations from individuals and convert them into computational structures is defined. For the creation of knowledge bases the use of Knowledge Engineering is accounted and later on the data is transferred into structures based on Fuzzy Cognitive Maps. Once the maps are created, their performances get improved through the use of a Particle Swarm Optimisation algorithm as a learning method, readjusting its predicting capacity from stored scenarios, where individuals left their preferences in front of random situations. Another important result is clustering the maps for knowledge discovery. This permits to find useful groups of individuals that policymakers can use for simulating new rules and policies. After rel..
Alternative solutions to traditional approaches to risk analysis and decision making using fuzzy logic
Get PDFFuzzy set theory (FST) and Fuzzy logic (FL) are one of the main components of soft computing which is a collection of techniques to handle hard problems in which the application of traditional approaches fails. The father of FST and FL stated that the dominant aim of SC is to exploit the tolerance for imprecision and uncertainty to achieve tractability, robustness, and low solution cost. Since its establishment the theory of fuzzy sets and fuzzy logic became very popular and received much attention especially
during the last decade being applied in many different fields. The wide use of fuzzy controllers in many massproduced products resulted in the increase of research in fuzzy set theory and fuzzy logic. In this thesis we use the techniques that are based on FL and FST for risk analysis and risk-based decision making. There are several reasons for using FL and FST. Fuzzy logic is a true extension of conventional logic: thus anything that was built using conventional design techniques can be built with
fuzzy logic. Another advantage is that it is close to human
reasoning, and it is easy to understand for the users who do
not have strong mathematical knowledge. A fuzzy system allows the user to use and to reason with words instead of crisp numbers. In addition, FL also offers a wide range of operators to perform efficient combinations of fuzzy predicates. In this thesis we propose alternative solutions to the existing approaches that use FL and FST for risk analysis and risk-based decision making. We investigated the current approaches, and we actually found that there exists only a small amount of researches that focus on risk analysis by using fuzzy logic. As far as we found, there are very few approaches that are generic and representative enough to be applied generally and to be used for complex problems. The existing approaches are very specific, targeting a particular area concentrating on specific types of risks. In this thesis we propose several different frameworks and algorithms based on FST and FL. First, we introduce two algorithms to rank the generalized fuzzy
numbers. The main reason for developing a new ranking algorithm is that the existing ranking algorithms have some disadvantages that make them not suitable for risk assessment and decision making. We used our algorithms in risk-aware decision making related to the choice of alternatives. Second, we introduce a pessimistic approach to assess the impact of risk factors on the overall risk. The methods that use the fuzzy weighted average often give a lower result than the real risk especially in the case of a large amount of input variables. Furthermore, the traditional approaches of using fuzzy inference systems may give the same result for different cases depending on the choice of the defuzzification method. For the pessimistic approach we used our developed algorithms of ranking generalized fuzzy numbers. Next we propose the use of Fuzzy Bayesian Networks (FBNs) for risk assessment. While there is a considerable number of studies for Bayesian networks (BNs) for risk analysis and decision making, as far as we found there is not a study to make use of FBNs even though FBNs seem more appropriate and straightforward to use for risk analysis and risk assessment. In general, there is only a small amount of studies about FBNs, and not in many application fields. The last approach discussed in this thesis is the use of Fuzzy Cognitive Maps (FCMs) for risk analysis and decision making. We propose a new framework for group decision making in risk analysis using Extended FCMs. In addition we developed a new type of FCMs, Belief Degree Distributed FCMs, and we show its use for decision making
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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