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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Lärarna och Studi.se : En studie av lärares uppfattningar om användande av det digitala läromedlet Studi.se / The Teachers and Studi.se

Bodemyr, Sanna, Nilsson, Ulrika January 2014 (has links)
This study is a thesis project for the program Civilingenjör och Lärare at KTH. The study was conducted in spring 2014 in collaboration with Komplementskolan AB which has developed the educational material Studi.se, the focal point of this study. The overall aim of the study is to increase the knowledge of the participant teachers’ conception and use of the educational material Studi.se. The second purpose is to increase knowledge about the forms of use some of these teachers apply or claim to apply when using Studi.se. Theoretical framework used is constructivism and the notions of Piaget: adaptation, assimilation and accommodation. Roger’s Innovation-Decision process and Puentedura’s SAMR-model have been the analysis tools used. The method used is that of triangulation where action research has been supplemented by questionnaire, interviews and observations, as well as the analysis of logged data over schools' test periods. The results show that one of the main reasons for using Studi.se is that the educational material has a good basic level which to a great extent fit the needs of students with special needs. Additional reasons for using Studi.se are that the educational material is simple, time saving and suitable for reviewing and repetition. Reasons for not using Studi.se is an initial lack of time, the cost, lack of transparency at first glance and the perceived challenge given through the material. Studi.se is primarily used as a supplement to the regular curriculum where the material is mainly used individually in the form of repetition, variation and to cover things that the students have missed. / Denna studie utgör ett examensarbete på programmet Civilingenjör och Lärare, inom teknik och lärande på KTH. Studien har utförts under våren 2014 i samarbete med Komplementskolan AB som tagit fram läromedlet Studi.se kring vilket arbetet kretsat. Studiens övergripande syfte är att öka kunskapen om de skäl lärarna i studien ger uttryck för, för att använda eller inte använda läromedlet Studi.se. Det andra syftet är att öka kunskapen om de användningsformer några av lärarna tillämpar eller säger sig tillämpa vid användande av Studi.se. Studien utgår från ett konstruktivistiskt perspektiv med stöd i Piagets begrepp adaptation, assimilation och ackommodation. Rogers Innovation-Decision process och Puenteduras SAMR-modell utgör arbetets analysverktyg. Insamlingen av data har skett genom en metodtriangulering där aktionsforskning har kompletterats av enkätundersökning, intervjuer och observationer samt av analys av loggad data över skolors testperioder. Studiens resultat visar att ett av de främsta skälen för att använda Studi.se är att ämnesmaterialet håller en bra grundläggande nivå som i stor utsträckning passar elever med särskilda behov. Ytterligare skäl för användande är att läromedlet är enkelt, tidsbesparande och lämpar sig för repetition. Skäl till att inte använda Studi.se är en initial tidsbrist, kostnaden, brist på tydlighet i första mötet och upplevd avsaknad av utmaning i materialet. Studi.se används i huvudsak som ett komplement till den ordinarie undervisningen där materialet framförallt används individuellt i form av repetition, variation och för att täcka upp sådant som eleverna missat.
42

Autonomous UAV Path Planning using RSS signals in Search and Rescue Operations

Anhammer, Axel, Lundeberg, Hugo January 2022 (has links)
Unmanned aerial vehicles (UAVs) have emerged as a promising technology in search and rescue operations (SAR). UAVs have the ability to provide more timely localization, thus decreasing the crucial duration of SAR operations. Previous work have demonstrated proof-of-concept in regard to localizing missing people by utilizing received signal strength (RSS) and UAVs. The localization system is based on the assumption that the missing person wears an enabled smartphone whose Wi-Fi signal can be intercepted. This thesis proposes a two-staged path planner for UAVs, utilizing RSS-signals and an initial belief regarding the missing person's location. The objective of the first stage is to locate an RSS-signal. By dividing the search area into grids, a hierarchical solution based on several Markov decision processes (MDPs) can be formulated which takes different areas probabilities into consideration. The objective of the second stage is to isolate the RSS-signal and provide a location estimate. The environment is deemed to be partially observable, and the problem is formulated as a partially observable Markov decision process (POMDP). Two different filters, a point mass filter (PMF) and a particle filter (PF), are evaluated in regard to their ability to correctly estimate the state of the environment. The state of the environment then acts as input to a deep Q-network (DQN) which selects appropriate actions for the UAV. Thus, the DQN becomes a path planner for the UAV and the trajectory it generates is compared to trajectories generated by, among others, a greedy-policy.  Results for Stage 1 demonstrate that the path generated by the MDPs prioritizes areas with higher probability, and intuitively seems very reasonable. The results also illustrate potential drawbacks with a hierarchical solution, which potentially can be addressed by considering more factors into the problem. Simulation results for Stage 2 show that both a PMF and a PF can successfully be used to estimate the state of the environment and provide an accurate localization estimate. The PMF generated slightly more accurate estimations compared to the PF. The DQN is successful in isolating the missing person's probable location, by relatively few actions. However, it only performs marginally better than the greedy policy, indicating that it may be a complicated solution to a simpler problem.
43

Data-Driven Policies for Manufacturing Systems and Cyber Vulnerability Maintenance

Roychowdhury, Sayak 12 October 2017 (has links)
No description available.
44

An examination of the factors influencing the decision to adopt alternative fuel vehicles

Campbell, Amy R. January 2014 (has links)
Concerns over the environmental impacts of the transport sector have led to the United Kingdom (UK) Government establishing a legally binding commitment of an 80% reduction in greenhouse gas emissions by 2050 (relative to the 1990 baseline) through the Climate Change Act 2008. The decarbonisation of the transport sector by 2050 will substantially contribute towards achieving this target. Technological innovations, therefore, have an important role in supporting policy objectives. One innovation that is being developed for this purpose in the transport sector is an alternative fuel vehicle. While there are several alternative fuel vehicle technologies, the only two with zero tailpipe (exhaust) emissions are battery electric vehicles and hydrogen fuel cell vehicles. Both of these technologies are not yet at a stage in their development where they can successfully compete with conventional fuel vehicles (internal combustion engine vehicles). They face a variety of technological hurdles that include range, performance, cost, and infrastructure. Hydrogen fuel cell vehicles are not commercially available, although battery electric vehicles have been on the commercial market for several years. Uptake of alternative fuel vehicles is occurring at a slower pace than hoped by policy makers and manufacturers. The aim of this thesis is to examine the factors influencing the decision to adopt an alternative fuel vehicle, and is underpinned by Rogers (2003) Diffusion of Innovations theory. The Innovation-Decision Process from this theory posits that an individual must first know about an innovation before forming an attitude about it. Innovativeness is instrumental in determining the knowledge an individual has of an innovation and how early in the diffusion process they are likely to become an adopter. Perceptions of the innovation are influential in forming an attitude towards it. The focus of the research is on Birmingham, the UK s second largest city. The first stage of the research involves establishing the locations of individuals across the city that possess socio-demographic characteristics associated with early adopters of alternative fuel vehicles. This is achieved by applying cluster analysis to Birmingham census data, which enabled the identification of a strong spatial cluster of potential early adopters in the suburb of Sutton Coldfield. In the second stage of the research, a household questionnaire was undertaken with 413 respondents in Sutton Coldfield. The analysis of the questionnaire data firstly involves the verification of the early adopter characteristics from stage one by examining the relationship of these characteristics with innovativeness. Analysis is then undertaken of the level of knowledge and the perceptions that the respondents have of alternative fuel vehicles. The final step in the analysis is an evaluation of the characteristics of current models of electric vehicles and how well aligned they are with the driving needs and vehicle expectations of respondents. The results confirm that the knowledge of alternative fuel vehicles is limited and individual perceptions have led to the development of negative attitudes towards them. Socio-demographic characteristics were significant in influencing these factors. There were 5% (21) of respondents who have previously considered the adoption of an electric vehicle but have not yet done so. There is evidence from the survey of active rejection among a small number of respondents. The reasons largely relate to three problems: purchase price, limited range, and poor infrastructure availability. However, the majority of respondents have passively rejected alternative fuel vehicles, such that they have never given consideration to the adoption of one. This confirms that a concerted effort is required to inform the general public about alternative fuel vehicles. Opportunities for increasing adoption have been identified for policy and marketing, including education and awareness-raising campaigns.
45

A leader-follower partially observed Markov game

Chang, Yanling 07 January 2016 (has links)
The intent of this dissertation is to generate a set of non-dominated finite-memory policies from which one of two agents (the leader) can select a most preferred policy to control a dynamic system that is also affected by the control decisions of the other agent (the follower). The problem is described by an infinite horizon total discounted reward, partially observed Markov game (POMG). Each agent’s policy assumes that the agent knows its current and recent state values, its recent actions, and the current and recent possibly inaccurate observations of the other agent’s state. For each candidate finite-memory leader policy, we assume the follower, fully aware of the leader policy, determines a policy that optimizes the follower’s criterion. The leader-follower assumption allows the POMG to be transformed into a specially structured, partially observed Markov decision process that we use to determine the follower’s best response policy for a given leader policy. We then present a value determination procedure to evaluate the performance of the leader for a given leader policy, based on which non-dominated set of leader polices can be selected by existing heuristic approaches. We then analyze how the value of the leader’s criterion changes due to changes in the leader’s quality of observation of the follower. We give conditions that insure improved observation quality will improve the leader’s value function, assuming that changes in the observation quality do not cause the follower to change its policy. We show that discontinuities in the value of the leader’ criterion, as a function of observation quality, can occur when the change of observation quality is significant enough for the follower to change its policy. We present conditions that determine when a discontinuity may occur and conditions that guarantee a discontinuity will not degrade the leader’s performance. This framework has been used to develop a dynamic risk analysis approach for U.S. food supply chains and to compare and create supply chain designs and sequential control strategies for risk mitigation.
46

Buyer Decision Process on the Market of Electric Shavers / Buyer Decision Process on the Market of Electric Shavers

Frič, Peter January 2009 (has links)
Buyer decision process is an important mechanism in the heads of consumers which leads them through purchase decisions. To understand behaviour of consumers, this process has to be analyzed and explained. Aim of this thesis is to analyze market of electric shavers in the Czech Republic and to determine key factors influencing purchase behaviour. Secondary and primary research are undertaken to reach the goal of the paper. In addition, five hypotheses are evaluated to verify author's expectations about the market of electric shavers for men in the Czech Republic. Analysis shows that consumers base their decisions about shavers mostly on performance and price. Though, majority of consumers do not buy shavers themselves, but receive it as a present from close family or relatives.
47

Algoritmos eficientes para o problema do orçamento mínimo em processos de decisão Markovianos sensíveis ao risco / Efficient algorithms for the minimum budget problem in risk-sensitive Markov decision processes

Moreira, Daniel Augusto de Melo 06 November 2018 (has links)
O principal critério de otimização utilizado em Processos de Decisão Markovianos (mdps) é minimizar o custo acumulado esperado. Embora esse critério de otimização seja útil, em algumas aplicações, o custo gerado por algumas execuções pode exceder um limite aceitável. Para lidar com esse problema foram propostos os Processos de Decisão Markovianos Sensíveis ao Risco (rs-mdps) cujo critério de otimização é maximizar a probabilidade do custo acumulado não ser maior que um orçamento limite definido pelo usuário, portanto garantindo que execuções custosas de um mdp ocorram com menos probabilidade. Algoritmos para rs-mdps possuem problemas de escalabilidade quando lidam com intervalos de custo amplos, uma vez que operam no espaço aumentado que enumera todos os possíveis orçamentos restantes. Neste trabalho é proposto um novo problema que é encontrar o orçamento mínimo para o qual a probabilidade de que o custo acumulado não exceda esse orçamento converge para um máximo. Para resolver esse problema são propostas duas abordagens: (i) uma melhoria no algoritmo tvi-dp (uma solução previamente proposta para rsmdps) e (ii) o primeiro algoritmo de programação dinâmica simbólica para rs-mdps que explora as independências condicionais da função de transição no espaço de estados aumentado. Os algoritmos propostos eliminam estados inválidos e adicionam uma nova condição de parada. Resultados empíricos mostram que o algoritmo rs-spudd é capaz de resolver problemas até 103 vezes maior que o algoritmo tvi-dp e é até 26.2 vezes mais rápido que tvi-dp (nas instâncias que o algoritmo tvi-dp conseguiu resolver). De fato, é mostrado que o algoritmo rs-spudd é o único que consegue resolver instâncias grandes dos domínios analisados. Outro grande desafio em rs-mdps é lidar com custos contínuos. Para resolver esse problema são definidos os rs-mdps híbridos que incluem variáveis contínuas e discretas, além do orçamento limite definido pelo usuário. É mostrado que o algoritmo de programação dinâmica simbólica (sdp), existente na literatura, pode ser usado para resolver esse tipo de mdps. Esse algoritmo foi empiricamente testado de duas maneiras diferentes: (i) comparado com os demais algoritmos propostos em um domínio em que todos são capazes de resolver e (ii) testado em um domínio que somente ele é capaz de resolver. Os resultados mostram que o algoritmo sdp para rs-mdp híbridos é capaz de resolver domínios com custos contínuos sem a necessidade de enumeração de estados, porém em troca do aumento do custo computacional. / The main optimization criterion used in Markovian Decision Processes (mdps) is to minimize the expected cumulative cost. Although this optimization criterion is useful, in some applications the cost generated by some executions may exceed an acceptable threshold. In order to deal with this problem, the Risk-Sensitive Markov Decision Processes (rs-mdps) were proposed whose optimization criterion is to maximize the probability of the cumulative cost not to be greater than an user-defined budget, thus guaranteeing that costly executions of an mdp occur with least probability. Algorithms for rs-mdps face scalability issues when handling large cost intervals, since they operate in an augmented state space which enumerates the possible remaining budgets. In this work, we propose a new challenging problem of finding the minimum budget for which the probability that the cumulative cost does not exceed this budget converges to a maximum. To solve this problem, we propose: (i) an improved version of tvi-dp (a previous solution for rs-mdps) and (ii) the first symbolic dynamic programming algorithm for rs-mdps that explores conditional independence of the transition function in the augmented state space. The proposed algorithms prune invalid states and perform early termination. Empirical results show that rs-spudd is able to solve problems up to 103 times larger than tvi-dp and is up to 26.2 times faster than tvi-dp (in the instances tvi-dp was able to solve). In fact, we show that rs-spudd is the only one that can solve large instances of the analyzed domains. Another challenging problem for rs-mdps is handle continous costs. To solve this problem, we define Hybrid rs-mdps which include continous and discrete variables, and the user-defined budget. In this work, we show that Symbolic Dynamic Programming (sdp) algorithm can be used to solve this kind of mdps. We empirically evaluated the sdp algorithm: (i) in a domain that can be solved with the previously proposed algorithms and (ii) in a domain that only sdp can solve. Results shown that sdp algorithm for Hybrid rs-mdps is capable of solving domains with continous costs, but with a higher computational cost.
48

Paving the Path to Purchase : a study on the integration of a branded retail application in physical stores

Gabrielsson Dukstenieks, Vendela, Strinnhed, Maya January 2019 (has links)
The purpose of this study was to explore the integration of a branded retail application in physical stores. Doing so, this study was conducted with a qualitative and abductive approach in the form of a case study focusing on H&M. The empirical material was collected through think-aloud observations and semi-structured interviews with 22 participants in total. The theoretical framework consisted of 6 aspects related to smart customer experience, including convenience and time convenience, personalisation, interactivity, control, usefulness, and involvement. Furthermore, the concept of the purchase decision process was also included in the theoretical framework. Five themes regarding the usage of the branded retail application in physical stores was found, including prior store visit usage and in-store usage, in-store information, selective information, visualisation of items in-store, and in-store communication. From this, it was concluded that using the app in-store provide several benefits depending on how the app is used. This leads to the conclusion that the app influences in different phases of the purchase decision process.
49

A heurística da ancoragem e seus efeitos no julgamento: decisões de consumo / The anchoring heuristic and its effects in judgment: consume decisions

Luppe, Marcos Roberto 28 August 2006 (has links)
Este trabalho destina-se a realizar um estudo dos efeitos da heurística da ancoragem em estimativas numéricas, e esta fundamentado em pressupostos teóricos apresentados por Amos Tversky e Daniel Kahneman em um estudo seminal de 1974. Sendo assim, este trabalho tem por objetivo examinar quais os efeitos da heurística da ancoragem nas estimativas numéricas sob a perspectiva da avaliação de bens de consumo. Os objetivos específicos foram testar o método proposto por Jacowitz e Kahneman (1995) para a mensuração dos efeitos da ancoragem em estimativas de quantidades incertas e comparar os resultados deste estudo, com os resultados dos trabalhos realizados anteriormente nesta área em outros países. O método utilizado segue as etapas propostas por Jacowitz e Kahneman (1995). Os resultados indicaram que, embora, novos experimentos sejam necessários para um avanço no entendimento de como a ancoragem pode influenciar o processo decisório de consumo, a confirmação da manifestação dos efeitos da ancoragem na estimação de quantidades incertas no experimento 1, e dos preços de diferentes produtos e serviços no experimento 2, numa avaliação do grupo total de participantes da pesquisa, foi a principal contribuição deste trabalho, além de seus resultados corroborarem com os resultados encontrados em estudos similares realizados em outros países, revelando que, no contexto brasileiro, também se observam os efeitos da ancoragem. Além disso, os resultados estendem a pesquisa dos efeitos da ancoragem na estimação do preço de produtos e serviços, e contribui para um melhor entendimento do comportamento do consumidor. Especificamente, o experimento 2 fornece novas percepções relativas aos estudos da ancoragem e indica como um número arbitrário apresentado a um indivíduo pode alterar o seu julgamento, quanto ao preço de um produto ou serviço. Deste modo, esses resultados sugerem que, em vez de dependerem de um enfoque mais passivo na estimação do valor de um produto para os compradores em potencial, e fixarem um preço de acordo com os métodos tradicionais de precificação, os varejistas podem adotar um papel mais ativo na determinação dos preços de determinados produtos, baseados na análise de fatores subjetivos que afetam os julgamentos de preços dos consumidores. / This research paper aims to study the effects of anchoring heuristic in numerical estimates, based on the theoretical presuppositions presented in the seminal work of Amos Tversky and Daniel Kahneman in 1974. The purpose of this work is hence to examine what effects of anchoring heuristic has in numerical estimates for an assessment of consumer goods. The specific objectives were to test the method suggested by Jacowitz and Kahneman (1995) to measure the anchoring effects in estimates of uncertain quantities and compare the results of this study with those of surveys previously conducted in this field in other countries. The method used follows the steps suggested by Jacowitz and Kahneman (1995). The results indicated that, although new experiments are necessary to further understand how the anchoring is likely to influence the consumer decision process, the confirmed appearance of the anchoring effects on the estimate of uncertain quantities in experiment 1, and the prices of different products and services in experiment 2, in an overall group assessment of those who participated in the research, was the main contribution to this work, besides the fact that its results corroborated the results found in similar studies conducted in other countries, thereby revealing that the anchoring effects are also observed in the Brazilian context. Moreover, the results broaden the research on the anchoring effects when estimating product and service prices, and contribute to a better grasp of consumer behaviour. Experiment 2, more specifically, supplies new perceptions as to surveys on anchoring and reveals how an arbitrary number presented to an individual can change their judgement as to the price of a product or service. Hence, the results suggest that instead of having to concentrate more passively on a value estimate of a product for potential buyers and fixing a price according to traditional pricing methods, retailers may adopt a more active role when fixing the price of specific products, based on the analysis of subjective factors that affect the consumer’s judgement on prices.
50

Dynamic modeling in sustainable operations and supply chain management

Liu, Baolong 06 September 2018 (has links)
Cette thèse articule plusieurs questions importantes dans les opérations durables et la gestion de la chaîne d'approvisionnement, non seulement afin de fournir des idées pour améliorer la performance des entreprises, mais aussi pour inciter ces dernières à adopter les moyens appropriés pour un meilleur environnement de notre société. Le lien entre le niveau de l'entreprise et le niveau de la société est que l'amélioration de la performance écologique par une meilleure gestion des opérations dans les entreprises et les chaînes d'approvisionnement est un élément indispensable pour améliorer l'environnement dans notre société. Prenons la Chine comme exemple. Depuis quelques années, le gouvernement a commencé à favoriser toutes les initiatives pour résoudre les problèmes de pollution de l'air. Un moyen important et utile est de mettre en place une réglementation stricte et de surveiller les efforts des entreprises qui seront passibles d'amendes sérieuses si certaines normes ne sont pas respectées par des inspections aléatoires. Par conséquent, les entreprises doivent coopérer pour améliorer leur rentabilité et, plus important encore, leurs impacts environnementaux. Grâce à cet effort prolongé, malgré le fait que la situation future est incertaine, la qualité de l'air s'est progressivement améliorée en Chine. Cette thèse, dans un cadre plus général, vise à fournir aux entreprises des informations importantes afin qu'elles soient non seulement en mesure de respecter la réglementation, mais aussi en mesure d'apporter véritablement leur contribution à la construction d'un environnement meilleur pour les générations futures. Notre objectif fondamental est d'obtenir une compréhension approfondie des compromis auxquels les entreprises sont confrontées, de modéliser les problèmes de recherche de solutions possibles et d'aider les entreprises/chaînes d'approvisionnement à améliorer leur performance d'un point de vue théorique. Ensuite, la thèse aidera indirectement les entreprises à réaliser l'importance du développement de moyens de gestion durable des opérations et de la chaîne d'approvisionnement sur notre société. La thèse est organisée comme la structure suivante. Le chapitre 3 est le premier essai, Environmental Collaboration and Process Innovation in Supply Chain Management with Coordination. Le chapitre 4 comprend le contenu du deuxième essai, Remanufacturing of Multi-Component Systems with Product Substitution, et le troisième essai, Joint Dynamic Pricing and Return Quality Strategies Under Demand Cannibalization , est présenté au chapitre 5. Le chapitre 6 donne les remarques finales générales des trois essais, suivies de la liste de référence, et les annexes. / This thesis articulates several important issues in sustainable operations and supply chain management not only to provide insights for enhancing the performance of firms but also to appeal to the enterprises to adopt appropriate means for a better environment of our society. The link from firm level to society level is that, to improve the green performance through better operations management efficiency in firms and supply chains, is an indispensable element to ameliorate the environment in our society. Taking China as an example. Since a few years ago (The Straitstimes, 2017; Stanway & Perry, 2018), the government started to spare no effort in resolving the air pollution problems. An important and useful means is to put strict regulations and monitoring the efforts of firms which will face serious fine if certain standards are not met by random inspection. Therefore, firms have to cooperate for the betterment of its profitability and, more importantly, the environmental impacts. Throughout the endeavor, despite the uncertain future situation, the air quality has gradually improved in China (Zheng, 2018). This thesis, in a more general setting, aims to provide important insights to firms so that they are not only able to meet the regulations but genuinely to make contributions to building a better environment for our future generations. Basically, our goal is to obtain deep understanding of the trade-offs with which companies are faced, and to model the problems for seeking possible solutions and helping firms/supply chains to enhance their performance from a theoretical point of view. Then, indirectly, the work will help firms to realize the importance of developing sustainable operations and supply chain management means on our society. The structure of the thesis is organized as follows. Chapter 2 introduces the thesis in French. Chapter 3 is the first essay, Environmental Collaboration and Process Innovation in Supply Chain Management with Coordination. Chapter 4 includes the contents of the second essay, Remanufacturing of Multi-Component Systems with Product Substitution , and the third essay, Joint Dynamic Pricing and Return Quality Strategies Under Demand Cannibalization, is introduced in Chapter 5. Chapter 6 gives the general concluding remarks of the three essays which is followed by the reference list and the appendices.

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