Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Um método numérico espectronodal (END) livre de erros de truncamento espacial é desenvolvido para problemas unidimensionais de difusão de nêutrons monoenergéticos em duas versões. Na versão de problemas de autovalor, o método gera soluções numéricas para o perfil do fluxo escalar e para o fator de multiplicação efetivo (k), que coincidem com a solução analítica dominante, afora os erros da aritmética finita computacional. Na versão de fonte fxa, o método também gera soluções numéricas analíticas para o problema de fonte fixa correspondente, onde a fonte de fissão, com dependência espacial, é obtida analiticamente, a partir da reconstrução espacial do fluxo escalar gerado pelo método END para problemas de autovalor. Alguns experimentos numéricos são apresentados para dois problemas modelos a fim de ilustrar a precisão do método.

Depuis les années 80 la cartographie optique est devenu un outil important pour l'étude et la compréhension des arythmies cardiaques. Cette expérience permet la visualisation de flux de fluorescence à la surface du tissu ; fluorescence qui est directement liée au potentiel transmembranaire. Dans les observations en surface se cachent des informations sur la distribution en trois dimensions de ce potentiel. Nous souhaitons exploiter ces informations surfaciques afin de reconstruire le front de dépolarisation dans l'épaisseur. Pour cela nous avons développé une méthode basée sur la résolution d'un problème inverse. Le modèle direct est composée de deux équations de diffusion et d'une paramétrisation du front de dépolarisation. La résolution du problème inverse permet l'identification des caractéristiques du front. La méthode a été testée sur des données in silico avec différentes manières de caractériser le front (sphère qui croît au cours du temps, équation eikonale). Les résultats obtenus sont très satisfaisants et comparés à une méthode développée par Khait et al. [1]. Le passage à l'étude sur données expérimentales a mis en évidence un problème au niveau du modèle. Nous détaillons ici les pistes explorées pour améliorer le modèle : illumination constante, paramètres optiques, précision de l'approximation de diffusion. Plusieurs problèmes inverses sont considérés dans ce manuscrit, ce qui implique plusieurs fonctionnelles à minimiser et plusieurs gradients associés. Pour chaque cas, le calcul du gradient est explicité, le plus souvent par la méthode de l'adjoint. La méthode développée a aussi été appliquée à des données autres que la cartographie optique cardiaque. / Since the 80's optical mapping has become an important tool for the study and the understanding of cardiac arythmias. This experiment allows the visualization of fluorescence fluxes through tissue surface. The fluorescence is directly related to the transmembrane potential. Information about its three-dimension distribution is hidden in the data on the surfaces. Our aim is to exploit this surface measurements to reconstruct the depolarization front in the thickness. For that purpose we developed a method based on the resolution of an inverse problem. The forward problem is made of two diffusion equations and the parametrization of the wavefront. The inverse problem resolution enables the identification of the front characteristics. The method has been tested on in silico data with different ways to parameter the front (expanding sphere, eikonal equation). The obtained results are very satisfying, and compared to a method derived by Khait et al. [1]. Moving to experimental data put in light an incoherence in the model. We detail the possible causes we explored to improve the model : constant illumination, optical parameters, accuracy of the diffusion approximation. Several inverse problems are considered in this manuscript, that involves several cost functions and associated gradients. For each case, the calculation of the gradient is explicit, often with the gradient method. The presented method was also applied on data other than cardiac optical mapping.

Disaster victims and vulnerable populations are audiences that communications professionals and scholars have ignored. Public relation practices dominate current disaster communication policy. This study examines the disaster communication network, including policy and practice, of the Thai Red Cross, before, during, and after the Asian tsunami. Disaster communication(s) is defined as the sharing and exchange of information with the victims immediately affected by a disaster. This definition focuses specifically on the vulnerable audience and allows response efforts to emerge from multiple disciplines. Focusing response efforts on victims' assessed needs and abilities allows for a multi-disciplinary approach to mitigate further suffering. The disciplines of health, development, and communications converge for efficient disaster management. This case study gives great insight into the cultural chasm between policy making and practical application and also reveals the value of personal initiative. A proposed model of disaster communication is offered. Significantly more research is needed in the area of disaster communications.

Under de senaste åren har kryptovalutor som Bitcoin blivit alltmer populära och genererat stor uppmärksamhet inom finansiella och tekniska kretsar. Trots den ökande populariteten och intresset för kryptovalutor som investeringsobjekt och spekulativt instrument, är deras användning som betalningsmedel fortfarande begränsad. Det finns flera faktorer som kan påverka användares acceptans av kryptovalutor för transaktioner, inklusive osäkerhet kring säkerhet och integritet, brist på reglering och stabilitet, och begränsad acceptans hos handlare och serviceleverantörer. Studiens syfte avser att undersöka varför kryptovaluta som betalningsmedel inte fått genomslag på den svenska marknaden, och de attityder som ligger till grund för detta. Till val av metod har triangulering använts för att samla in data genom vetenskapliga artiklar, enkäter och intervjuer. Fokus har legat på att få en förståelse för användare av kryptovalutor. Genom att engagera användarna direkt har vi haft möjlighet att lyssna på deras åsikter, erfarenheter och attityder på en djupare nivå. Genom att undersöka användares uppfattningar om att använda kryptovalutor som betalningsmedel, kan vi belysa viktiga insikter som kan forma framtida utveckling och acceptans av kryptovalutor. Samtliga data analyseras med hjälp av innehållsanalys. Resultatet som framställdes var att informationen kring kryptovalutor framstår i sin helhet som bristfällig. Genom att nå ökad förståelse kan man öka intresset och användningen av teknologin. Genom att undersöka och analysera olika aspekter av kryptovalutors acceptans och användning som betalningsmedel har vi identifierat flera viktiga faktorer som påverkar människors beslut att använda denna teknologi. Bland de främsta faktorerna är kunskap om kryptovalutor, uppfattningar om säkerhet och integritet, acceptans hos företag och serviceleverantörer, samt fördelarna med snabba och enkla transaktioner. Samtidigt har vi noterat att bristande kunskap och osäkerhet kring kryptovalutor kan vara en bromsande faktor för deras acceptans. För att öka användningen av kryptovalutor som betalningsmedel bör det finnas en kombination av utbildning, reglering, acceptans och incitament för användare. Detta kommer att underlätta för människor att fatta informerade beslut om sina ekonomiska transaktioner och främja en hållbar och säker användning av kryptovalutor. / In recent years, cryptocurrencies such as Bitcoin have become increasingly popular and generated a lot of attention in financial and technology circles. Despite the increasing popularity and interest in cryptocurrencies as an investment and speculative instrument, their use as a means of payment is still limited. There are several factors that can affect user acceptance of cryptocurrencies for transactions, including uncertainty about security and privacy, lack of regulation and stability, and limited acceptance by merchants and service providers. The purpose of the study is to investigate why cryptocurrencies haven’t break through as a payment method on the Swedish market, and what attitudes that contributes to this. We have used triangulation as a method to collect data through scientific articles, surveys, and interviews. The focus has been on gaining an understanding of cryptocurrency users. By engaging the users directly, we have had the opportunity to listen to their opinions, experiences, and attitudes on a deeper level. By examining users' perceptions of using cryptocurrencies as a means of payment, we can emphasize important insights that can shape the future development and acceptance of cryptocurrencies. All data is analyzed using content analysis. The information about cryptocurrencies appears to be deficient. By achieving increased understanding, interest and use of the technology can be increased. By researching and analyzing various aspects of cryptocurrency acceptance and use as a means of payment, we have identified several important factors that influence people's decisions to use this technology. Among the main factors are knowledge of cryptocurrencies, perceptions of security and privacy, acceptance by businesses and service providers, and the benefits of fast and easy transactions. At the same time, we have noted that lack of knowledge and uncertainty surrounding cryptocurrencies can be a slowing factor for their acceptance. To increase the use of cryptocurrencies as a means of payment, there should be a combination of education, regulation, acceptance, and incentives for users. This will facilitate people to make informed decisions about their financial transactions and promote the sustainable and safe use of cryptocurrencies.

本研究探討建構發展桌遊社群平台之營運模式及其關鍵成功因素，以形成執行策略與行動計畫。 本研究採文獻探討、深度參與、資料分析、探索性個案式研究，先以「SWOT矩陣分析」，來分析探討個案現況；再以「商業模式九宮格」以及「新創事業之精實商業模式十一格」兩者，來探討個案分析；之後，再以SWOT之分析結果，針對兩種宮格分析結果每一宮格之內容項目，再進行探討分析；也就是在兩種宮格分析後，每一格，再用SWOT去探討分析，由此呈現出更深入具體之執行策略與行動計畫。最後再輔以創新擴散模型來推論計算，各階段社群平台推廣之臨界數量與營運目標。終能更完整建構桌遊社群平台之營運模式，形成關鍵策略、競爭策略、行動策略等流程圖，並表列出各種行動方案之執行建議。 當手談趣在台灣成為會員數或開店數排名第一的桌遊社群平台之後，或可研究進入中國或全球之桌遊市場，探討中國或全球市場之桌遊社群平台營運模式；亦可考慮進入台灣、或中國、或全球之其他產業市場，進一步研究探討，台灣、中國、或全球市場其他產業之社群平台營運模式。 / This research tried to develop and complete the business model of table game online community platform also find out the key success factors of it, thus, we can form the executive strategy and action plans. This research used SWOT matrix to analyze the case situation, then used Business Model Canvas and Lean Canvas to examine the case analysis. Afterwards, we used the SWOT matrix to examine and analyze the Business Model Canvas and Lean Canvas by each canvas element again. Then, we used Innovation Diffusion Theory to calculate the critical mass and determine the quantitative objective of every stage. We can study on China or global market of table game online community platform or other industries via this research process after Sotanfun platform reaches success of the first or second stage of its quantitative objectives.