Dissertations / Theses on the topic 'E-wallet'

As the use of mobile payment applications (apps) and electronic wallets (e-wallets)increases, so does the demand for a improved user experience when interactingwith these apps. The field of Human-Computer interaction (HCI) focuses onthe design, evaluation, and implementation of interactive computing systems forhuman use. One aspect of HCI is usability, i.e., the quality of the interactions witha product or system. This thesis investigates how an e-wallet can be designed to provide a high level ofusability by conforming to best HCI practices and by formative evaluation using aset of usability evaluation methods.The research process consisted of an initial literature study and developmentof a prototype, which was evaluated iteratively through Thinking-aloud-protocol(TAP) and a combination of performance measurements and questionnaire by achosen test group. By each iteration, the results of the performance measurements, as well as theverbal data improved. The most complex or difficult task, for the test subjectsto perform, was, according to the results, Pay via manual input. All goals wereachieved for all tasks except for the performance goal of a percentage of errorsbelow 5%. To conclude, it was clear that the test subjects had more trouble understandingthe concept of the e-wallet rather than navigating and completing tasks. Thedifficulties lay in understanding how currencies were stored and how transactionshappened. When developing this e-wallet we noticed that the most importantissue was to make new functions and concepts familiar to the user through relatingit to recognizable ideas.
I och med att användning av mobila betalningslösningar (appar) och elektroniskaplånböcker (e-plånböcker) ökar, ökar även efterfrågan på en förbättradanvändarupplevelse vid interaktion med dessa appar. Området människadatorinteraktion(MDI) fokuserar på design, utvärdering och implementeringav interaktiva datorsystem för mänsklig användning. En aspekt av MDI äranvändbarhet, dvs kvaliteten på interaktionerna med en produkt eller ett system.Detta kandidatexamensarbete undersöker hur en e-plånbok kan utformas föratt ge en hög användbarhet genom att anpassas till MDI praxis och formativutvärdering av designen med hjälp av en uppsättning utvärderingsmetoder föranvändbarhet. Forskningsprocessen bestod av en litteraturstudie och utveckling av en prototoyp,som utvärderades iterativt genom Thinking-aloud Protocol (TAP) samt enkombination av prestationsmätningar och frågeformulär av en vald testgrupp.Efter varje iteration förbättrades resultaten av prestationsmätningarna, såvälsom för den verbala datan. Den mest komplexa eller svåra uppgiften,för testpersonerna att utföra, var, enligt resultaten, Betalning via manuelinmatning. Alla mål uppnåddes för alla uppgifter förutom prestationsmålet fören procentandel av fel under 5%. Avslutningsvis var det tydligt att testpersonerna fann det svårare att förståkonceptet av e-plånboken än att navigera och slutföra uppgifterna. Svårigheternalåg i att förstå hur valutor lagrades och hur transaktioner gick till. När viutvecklade den här e-plånboken märkte vi att den viktigaste uppgiften var att göranya funktioner och koncept förståerliga för användaren genom att koppla dem tilligenkännliga idéer.

With the rise of blockchain technology and cryptocurrency, secure e-wallets also become more important. But what makes an e-wallet secure? In this report, we compare different aspects of ewallets to see which alternatives are secure and convenient enough to be used.This report contains comparative analyses of different implementation for e-wallets. The problem area is divided into three smaller areas: Key storage, authentication, and recovery. These problem areas have defined criteria for what is considered good qualities in each respective area.The results show that for key storage, the best options are, Android’s keystore/IOS’ secure enclave, offline storage or a hybrid hot/cold storage. For authentication, the best alternatives proved to be BankID and local authentication through the phone’s OS. Good Recovery alternatives include recovery seeds that recover the whole e-wallet or using multiple keys for both signing and recovery.The proof of concept made for this project uses three different storage methods with the authentication methods for each one and with the possibility of recovery in case a key should be lost. The storage methods used are offline storage thought QR-codes, online storage with firebase and local storage with Android keystore or Secure enclave. Authentication is done with Facebook/Google sign in or local authentication.
Med blockkedja och kryptovalutornas ökande popularitet blir säkra e-plånböcker allt mer viktiga. Men vad gör en e-plånbok säker? I detta arbete ska olika implementationer för e-plånböcker undersökas för att se vilka alternativ som är tillräckligt säkra samt användarvänliga.Problemområdena delas upp i följande delar: nyckellagring, autentisering och återhämtning av stulen/förlorade nycklar. Arbetet innefattar jämförelser mellan olika lösningar till dessa områden med definierade jämförelsekriterier.Resultatet visar att för nyckellagring är de bästa alternativen Androids keystore system/IOS secure enclave som båda är en form av säker lagringsplats på telefonen, offline lagring och hybridlagring som enkelt förklarat är en tjänst som bevarar data offline och gör den online när användaren väl vill ha tillgång till datan. För autentisering är de bästa alternativen BankID och lokal autentisering genom telefonens operativsystem. För återhämtning av nycklar är de bästa alternativen recovery seed eller att använda multipla nycklar för både signering och återhämtning.En proof of concept gjordes där lagringsmetoderna papper (exempelvis QR-kod), online-lagring med Firebase och lokal lagring med Android keystore eller Secure enclave implementerats. Autentiseringen sker med hjälp av Facebook/Google login och lokal autentisering. Återhämtning görs med två utav tre nycklarna som används för både signering och återhämtning.

Magister Legum - LLM
This paper analyses how the Zimbabwean economic history has led to the perception and attitude of the population towards the financial industry. It has been blighted by extremes to the extent that in 2008 the Zimbabwe economy had one of the highest hyperinflation rate in the world. Pettinger sums up the hyperinflation journey of Zimbabwe as having begun in the 1990s shortly after the disastrous land reform. This is where private farms were grabbed from landowners and re-allocated to mostly peasant farmers who had no technical know-how in farming. It was also a time when the country was involved in an unbudgeted and unsolicited second Congo civil war necessitating that the Government increase salaries to cater for soldiers and other officials assigned to the Congo. Earlier on the government had buckled under pressure from former war liberators (war veterans) and paid out unbudgeted bonuses.

Questo elaborato si propone di analizzare il tema delle criptovalute, argomento a cui si è interessato un numero sempre maggiore di persone negli ultimi anni, di modo da offrire uno strumento informativo che consenta una più ampia comprensione della materia in esame. Le criptovalute sono oggetti informatico-digitali che stanno determinando cambiamenti sempre più radicali nella nostra quotidianità: dalla concezione del denaro a quella della realtà virtuale, con l’avvento del “Metaverso”, dal sistema sanitario alla votazione elettronica (e-voting), dall’ambito giuridico al settore finanziario, tanto da determinare la nascita di un nuovo settore, il FinTech o TecnoFinanza. Colossi dell’economia mondiale -come Apple, Wordpress, Satispay e tanti altri- hanno deciso di accettare pagamenti in criptovalute aprendo così la strada dello shopping online, e non solo, anche alle monete virtuali. L’obiettivo della tesi è, quindi, quello di formare il lettore fornendo un testo consultabile che partendo dalle origini storico-economiche e dalle tecnologie alla base di queste valute, arriva ad analizzarle individualmente, soffermandosi sul loro impatto sociale, ambientale, politico ed economico.

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Nenhuma
O uso de dispositivos móveis como meio de pagamento vem crescendo ao longo dos últimos anos. Embora algumas implantações de carteiras digitais tenham sido bem sucedidas, ainda não existe um padrão a ser utilizado pelo mercado. Este trabalho tem como objetivo apresentar uma solução para pagamento móvel através da utilização de uma carteira digital. Esta solução deve ser heterogênea, sendo disponibilizada para o maior número possível de dispositivos móveis, como telefones celulares e tablets, e deve permitir o pagamento entre dois usuários sem a necessidade de conexão à internet. O trabalho também leva em consideração as informações de contexto do usuário, e busca oferecer uma solução diferenciada ao usuário final, através da interface da aplicação com um servidor de pedidos, a ser instalado no estabelecimento comercial. A segurança também é um item importante, e o modelo deve prever a utilização de um elemento seguro, garantindo a segurança das informações gravadas no dispositivo. Foi desenvolvido um protótipo da arquitetura proposta, denominado Unipag. O protótipo foi desenvolvido através da avaliação de quatro diferentes soluções de carteira digital, sendo duas soluções acadêmicas e duas soluções comerciais. O protótipo foi desenvolvido inicialmente para o sistema Android, e foram realizadas duas avaliações. A avaliação por cenários demonstrou a utilização com sucesso da aplicação em cenários de pagamento cotidianos. A avaliação de usabilidade demonstrou que o aplicativo é de fácil utilização, e 96% dos usuários utilizariam a aplicação se disponível. Os resultados encorajam o estudo e demonstram a viabilidade da solução.
The use of mobile devices as a payment device has been growing over the last few years. Although some deployments of digital wallets have been successful, there is still no standard to be used by market. This work aims to present a solution for mobile payment through the use of a digital wallet. This solution must be heterogeneous, being made available to the largest possible number of mobile devices such as mobile phones and tablets, and should allow payment between two users without internet connection. The solution also considers the context information of the user, and seeks to offer a different solution to the end user through the application interface with a server application to be installed on the premises. Safety is also an important item, and the model should provide for the use of a secure element, ensuring the security of information stored on the device. We developed a prototype of the proposed architecture, called Unipag. The prototype was developed by evaluating four different solutions digital wallet, two academic solutions and two commercial solutions. The prototype was initially developed for the Android system, and were assessed twice. The evaluation scenarios demonstrated the successful use of the application for daily payment scenarios. The usability evaluation demonstrated that the application is easy to use, and 96% of users would use the application if available. The results encourage the study and demonstrate the feasibility of the solution.

A mobile wallet is a mobile application that is intended to replace leather wallets. With high mobile and Internet penetration and increased life expectancy in developed economies, adoption of mobile wallets by the older population is becoming more important due to new trends. Therefore, this thesis aims to understand and increase adoption of mobile wallets in developed economies by the citizens between the ages of 50 to 75. Based on the mobile payment technology acceptance model (MPTAM) and an extensive literature review, a simplified model is suggested. Three sub-questions (on 1 - social influence, 2 - perceived security, trust and risks, and 3 – perceived ease of use) are proposed for further study, which has been suggested in the literature to have more importance for the targeted demography. An exploratory qualitative study based on in-depth semi-structured interviews was conducted. The findings show that social influence can have direct or indirect effects. Moreover, several factors were identified that seems to have impacts on the degree to which a content can influence people. In addition, perceived trust, security, and risks seem to be the most important impediment for the adoption of mobile wallets, especially for risk-averse people. Furthermore, perceived ease of use can improve the values that mobile wallets may provide. Perceived ease of use is more important for the targeted age group since some of the potential users in this age group has reduced learning and physical abilities. Finally, many implications of the findings and methods to improve the adoption of mobile wallets for the selected demography, i.e. restriction and customization, use of familiar design, use of strong brands, etc. are suggested.

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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Este trabalho tem por objetivo apresentar um modelo de arquitetura e usabilidade para um sistema de pagamento móvel (Mobile Payment System), considerando as premissas de independência de dispositivo, de localização, de operadora de telefonia móvel e de administradora financeira para suprir as necessidades de efetivar pagamentos e recebimentos de qualquer natureza em ambientes de comércio ubíquo (Ubiquitous Commerce). O trabalho inicialmente descreve a motivação, os objetivos e os conceitos fundamentais sobre os quais se baseia a proposta do modelo. A seguir são elencados os principais trabalhos relacionados e uma análise comparativa detalhada é realizada, derivando as características mais importantes a serem consideradas no modelo proposto. Em seguida, é proposto um modelo de pagamento móvel, denominado 4iPay, onde são detalhados os objetivos, arquitetura, recursos e a proposta técnico-científica de comércio eletrônico em ambientes ubíquos. Na proposição do modelo foi considerada a convergência dos trabalhos relacionados analisados no que tange à ubiquidade, unicidade, universalidade e unissonância. Assim, o modelo 4iPay pretende reunir as melhores características, inovando e melhorando em alguns aspectos relevantes ao comércio ubíquo de fato. O modelo proposto visa propor uma solução diferenciada em termos de arquitetura, modelo de negócio, usabilidade, baixo consumo de banda e alto desempenho nas transações de pagamento e recebimento, em relação às propostas atuais, levando em consideração, nas transações comerciais eletrônicas móveis, questões como independência de dispositivo, localização física, segurança e confiabilidade, além de outras características expostas ao longo do trabalho, como otimização no uso de protocolos de comunicação e flexibilidade na utilização de conexões locais ou remotas. Também são descritos cenários efetivos de uso de onde e como o modelo 4iPay pode ser aplicado. Para tanto é apresentado o protótipo desenvolvido para avaliar o modelo. Por fim, são apresentados os resultados obtidos na avaliação dos cenários, nas avaliações de desempenho da aplicação e na pesquisa de campo de aceitação do modelo proposto.
This work aims at presenting a usability and architectural model for a mobile payment system. In our model, we assume independence of devices, of location, of mobile operator, and of administrator, to allow all kinds of payment in ubiquitous environments (Ubiquitous Commerce). In this work, we begin describing motivation, goals, and fundamental concepts, in which the proposed model is based. Next, we present related works and a detailed comparative analysis of those projects, deriving the most important features. Later, we propose a model of mobile payment, called 4iPay, based on those features. We detail the 4iPay model, architecture, features, and the technical-scientific proposal of an electronic commerce system in ubiquitous environments. We consider, in the proposed model, the convergence of various related works in terms of ubiquity, unity, universality, and unison. Thus, 4iPay aims at bringing together the best features, innovating and improving in some aspects. In the model, we propose a distinguished solution in terms of architecture, business model, usability, low bandwidth consumption and high performance in payment and receipt transactions. We also consider issues such as device independence, physical location, security and reliability, and other features related to mobile electronic commerce transactions, such as optimizing communications protocols usage and flexibility in local or remote connections. We also present the effective use in scenarios of where and how 4iPay can be applied. For this purpose we present the prototype developed to evaluate the model. Finally, we present the scenarios assessment results, the application performance evaluation and the proposed model acceptance survey.

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Este trabalho tem por objetivo analisar o caso da Paggo, a iniciativa de maior destaque em Mobile Payment no Brasil. A escolha pelo tema de Mobile Payment se deu devido ao seu caráter de inovação e disruptura num mercado consolidado como o de meios de pagamento. Através de uma análise qualitativa, o autor se propõe a identificar e elucidar alguns dos atributos básicos fundamentais necessários a uma iniciativa de Mobile Payment. Um modelo teórico foi então desenvolvido com o intuito de aplica-lo à iniciativa da Paggo de forma a verificar a presença destes atributos e seu alinhamento com o direcionamento das ações estratégicas da companhia. Por tratar de um caso específico, limitamos nossa análise ao modelo de Mobile Payment adotado pela Paggo (B2C). Para tal, foram analisados diferentes estudos de autores acadêmicos especializados no tema de inovações tecnológicas e governança. Teorias relativas a inovações em meios de pagamento (CHAKRAVORTI e KOBOR, 2003), economia da informação (SHAPIRO e VARIAN, 1999), adequação das ferramentas organizacionais para a tarefa (CHRISTENSEN e OVERDORF, 2000) e evolução da plataforma de Serviços (TIWANA, KONSYNSKI e BUSH, 2010) compõe a base dos atributos selecionados para o modelo proposto pelo autor. Do ponto de vista prático, foram entrevistados presencialmente o antigo e o atual presidente da Paggo com a finalidade de se coletar dados relativos a aspectos de inovação tecnológica, estrutura organizacional e governança ao longo da história da companhia. Estas entrevistas, transcritas ao final do estudo, por si só já se revelaram como uma grande contribuição a estudiosos do tema, que muitas vezes carecem de perspectivas tão amplas como as apresentadas nestas entrevistas. O tema é ainda mais relevante não apenas pelos impactos diretos e indiretos que sua implementação poderá trazer, não apenas sobre toda a cadeia de valor atual de meios de pagamentos mas, principalmente, para toda a sociedade brasileira visto que o governo brasileiro anunciou recentemente que o Ministério das Comunicações em conjunto com o Banco Central e a Agência Nacional de Telecomunicações (ANATEL) trabalham para apresentar uma proposta de marco regulatório para serviços de pagamento por meio de telefonia móvel ainda em 2012 . Este estudo é portanto de interesse de todos os agentes envolvidos no ecossistema de meios de pagamento: bancos, adquirentes, bandeiras de aceitação, fabricantes de dispositivos, governo e agencias reguladoras, além das operadoras de telefonia celular e outros agentes indiretos. Também é relevante para a sociedade em geral, representada pelos varejistas, comerciantes e prestadores de serviço que poderão se utilizar de novos meios de pagamento móveis e dos usuários finais (compradores) os quais poderão contar com novos serviços e uma dinâmica alternativa de pagamento para efetuar suas transações.

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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Lentinus citrinus (Walleyn e Rammeloo) DPUA 1535 from Culture Collections DPUA 1535/UFAM was analyzed as the production of proteases by submerged culture. A full factorial design 25 with three central points was established to evaluate the influence of nutrient sources, pH of the culture medium, temperature and incubation time, in the production of biomass and proteases. The extraction of proteases from culture broth with higher activity was prepared by aqueous two-phase systems, PEG/phosphate by using a full factorial design 23 with three central points. The results showed that the best condition for growth and proteases production was determinated in medium formulated with soluble starch, gelatin, pH 7,0, 25 oC in 5 days. It was found, in culture conditions, that only nitrogen source and temperature were significant in growth of L. citrinus, while for proteases production all variables were statistically significant. In PEG-phosphate systems, in all runs, the proteases moved to top phase, as well as the best conditions for extraction of enzymes were with obtained with PEG 6000, 17,5% (w/w) and phosphate 25% (w/w).
Lentinus citrinus (Walleyn e Rammeloo) DPUA 1535 da Coleção de Culturas DPUA/UFAM foi submetido a fermentação submersa para a produção de proteases. Um planejamento fatorial completo 25 com 3 pontos centrais foi elaborado para avaliar a influência de fontes nutricionais, pH do meio de cultivo, temperatura e tempo de incubação na produção de biomassa e de proteases em cultivo submerso. A extração das proteases do extrato bruto de maior atividade foi realizada pelo Sistema de Duas Fases Aquosas - SDFA - PEG-fosfato, utilizando-se um planejamento fatorial 23 com 3 pontos centrais. Os resultados mostraram que a melhor condição para o crescimento e produção das proteases secretadas por L. citrinus foi determinada no meio formulado com amido solúvel 0,5% (p/v) e gelatina 0,2% (p/v), pH 7,0, a 25 ºC, em 5 dias. Verificou-se que, nas condições de fermentação somente fonte de nitrogênio e temperatura influenciaram no crescimento de L. citrinus, enquanto na atividade proteolítica todas as variáveis foram estatisticamente significativas. No processo de extração, em todos os ensaios do sistema PEG-Fostato, as proteases particionaram para a fase superior e as melhores condições de extração dessas enzimas foram obtidas com PEG 6000 17,5% (m/m) e Fosfato 25% (m/m).

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
The present work describes the synthesis of a new catalyst of palladium nanoparticles supported on multi-walled carbon nanotubes containing nitrogen (Pd@CNxNCPM) 1 and its use in carbon-carbon coupling reactions (Suzuki and Heck) as well as reactions catalytic hydrogenation (reduction of double C-C bonds and nitro compounds reduction). The synthetic strategy employed afforded the simple way to obtain the catalyst with reaction in a short time and efficiently. To this was employed as the palladium precursor, the salt potassium hexacloropalladate IV and hydrazine monohydrate as the reducing agent, without the need for stabilizing agents for the control of nucleation and size of nanoparticle. The catalyst system was characterized as its morphology: dispersion, size and shape of nanoparticles by scanning electron microscopy. Also the catalyst was performed Raman spectroscopy and determination of amount of palladium. After characterization the catalyst, it was tested for coupling reactions of carbon-carbon: Suzuki and Heck leading to the formation of their products with 70-> 95% for Suzuki coupling and 75-> 95% for Heck. For the synthesis in question were used 0.5 mol% of catalyst (based amount of palladium) for Suzuki and 10 mol% for Heck. It should be noted that the catalyst shown stable in the reaction conditions tested, and observed the possibility of reuse of this system for additional reaction cycles without loss of efficiency for the Suzuki coupling. Also, the catalyst was efficient and chemoselectiv for catalytic hydrogenations of unsaturated carbon-carbon bonds and nitro compounds leading to their products in good yields. Thus, the synthesized catalyst proved versatile and can be used in reactions of carbon-carbon coupling well as in catalytic reduction may also be recovered and reused, which provides an environmentally friendly at the same characteristic.
O presente trabalho apresenta a síntese de um novo catalisador de nanopartículas de paládio suportadas em nanotubos de carbono de paredes múltiplas contendo nitrogênio (Pd@CNxNCPM) 1 e sua utilização em reações de acoplamento carbono-carbono (Suzuki e Heck) bem como em reações de Hidrogenações catalíticas (reduções de duplas ligações C-C e redução de nitrocompostos). A estratégia sintética utilizada permitiu a obtenção do catalisador de maneira simples, em curto tempo reacional e de maneira eficiente e sem a presença de agentes estabilizantes externos. Para isso foi empregado como precursor de paládio o sal hexacloropaladato IV de potássio e como agente redutor, hidrazina monohidratada sem a necessidade de agentes estabilizantes para o controle da nucleação e tamanho de nanopartículas. O sistema catalítico foi caracterizado quanto sua morfologia: dispersão, tamanho e forma de nanopartículas através de microscopia eletrônica de varredura. Também foi realizada espectroscopia Raman do catalisador bem como determinação do teor de paládio. Após devidamente analisado o catalisador, o mesmo foi testado para reações de acoplamento carbono-carbono de Suzuki e Heck levando a formação dos respectivos produtos com rendimentos de 70-> 95% para os acoplamentos de Suzuki e 75-> 95% para Heck. Para as sínteses em questão foram usados 0,5 mol% de catalisador (baseados na massa de paládio) para Suzuki e 10 mol% para Heck. Cabe salientar que o catalisador se mostra estável nas condições reacionais testadas, sendo observada a possibilidade de reuso deste sistema por ciclos reacionais adicionais, sem perdas de eficiência para o acoplamento de Suzuki. Ainda, o catalisador se mostrou eficiente para hidrogenações catalíticas quimiosseletivas de ligações de carbono-carbono insaturadas e nitrocompostos levando aos respectivos produtos em bons rendimentos. Dessa forma o catalisador sintetizado se mostrou versátil, sendo possível ser utilizado em reações de acoplamento carbono-carbono bem como em reduções catalíticas, também pode ser recuperado e reutilizado, o que confere ao mesmo uma característica ambientalmente correta.

碩士
國立臺灣大學
資訊工程學研究所
92
The progresses of computer and communication techniques have made themobile phones become more and more common and brought more related applications as well. The purpose of this thesis is to develop a small shopping system with mobile phones or personal digital assistant (PDA). The framework,functions, design manners, test environment and actual application environment of this system will be introduced in this paper. The test results have demonstrated that this system does work and we can go to any store that provides wireless electric wallet services to do our shopping conveniently and safely with this device.

碩士
高雄餐旅學院
餐旅管理研究所在職專班
98
Starbucksisthe most earliest coffee shop to import from seven-eleven to use electronic purse and that overall pre-paid price already over 1 billion dollars and to sell 52 million cards from Starbucks websites. The huge economic benefits already attraction more famous chain stores to establish the policies about electronic purse. Formally, Easycard corporation had to followed out Easycard icash and it can be used over ten thousand stores. So many places can be representative the economic benefits of electronic purse will looking forward be used in this market. Above, this research will discussion the key factors of consumer behavior with electronic purse and it can be draft difference marketing strategy in this market. This study used accidental sampling, 305 were valid samples which appropriate for further analysis. Demographic analysis, factor analysis, conduct reliability analysis, validity analysis, one-way anova, correlation analysis and regression analysis were used to examine the data. After integrating the results of the empirical analysis, the findings of the study are as follows: Perceived usefulness, Perceived ease of use, Attitude, Subjective norm, Perceived Risk are significant influence on the use of Electronic Purse intention. Especially the Perceived usefulness is highest. The demographic factors on the use of Electronic Purse intention are significant differences.

碩士
朝陽科技大學
資訊工程系碩士班
99
With Internet technology rapidly flourishing, e-commerce services have progressively emerged in daily life and brought convenience to the people. Electronic cash systems (or electronic wallet systems) play an important role in e-commerce, which enables users to not have to carry large amounts of cash while making transactions, or enables them to even complete transactions on the Internet. Additionally, each entry of electronic cash is recorded thoroughly, allowing users to check transaction records at any time. On-line electronic wallet systems require a prompt validation from banks while transactions take place. Compared to on-line electronic wallet systems, an off-line electronic wallet system is more practical and efficient, and payment does not require going through banks. However, an off-line wallet system tends to cause double-spending, and thus a more complex calculation design is essential to prevent the problem. This study employed related cryptographic techniques to design a fair and safe electronic cash system, ensuring the safety and anonymity of consumers to purchase by using electronic cash. The designed system employed agent techniques to achieve anonymity and prevent double-spending. When banks or anyone receives an electronic cash entry, an untraceable record enables the link between the entry and the consumer to remain anonymous. When consumers pay bills, they request the agent to issue electronic cash. Because purchase information, such as store name and time of purchase, are provided on the electronic cash entry, the consumer would not make double-spending. In terms of executive efficiency, our system used a minimal amount of modular exponentiations, modular multiplications, and the one-way hash function as algorithms to prove that our system can be effectively and practically applied to intelligent mobile devices via empirical statistics.

碩士
朝陽科技大學
資訊工程系碩士班
100
The fast growing of Internet and popularity of personal computers in recent years have gradually enable people to use kinds of E-commerce services, E-cash plays a rather significant role in e-commerce. It is not necessary to carry a large amount of money for transactions, instead the transaction can be completed via Internet and each transaction will be kept for the consumers’ reference. In this thesis, we design a multi-bank E-wallet system, based on certificateless signature technology, built in the smart mobile device. We adopt the structure simulating the smart mobile device as the bank card or checkbook to withdraw cash in different banks so the consumers are allowed to withdraw E-cash with the smart mobile device in the E-cash-issuance banks authorized by the central bank and save the e-cash in the smart mobile device to enhance consumers’ willingness and the convenience to use the service.

碩士
國立雲林科技大學
電子與資訊工程研究所
93
Owning to the technique of internet communication develops fast and the popularity of the net surfing in recent years, it makes the mankind living into a whole new digital world. The internet brings a limitless business but no most people are still waiting and see about the electronic trades. Now, how to establish a safe and an efficient electronic payment system is full of challenge to study for the academic and business associations. Most electronic payment systems are design for a single bank. This thesis is just design a secure mobile e-wallet with biometrics authentication on multiple-bank environment. And the design needs working by input the personal fingerprints to avoid stealing. The mobile e-wallet considers that the system is easy to carry, so it lacks of a long term electricity and limited ability to calculate. The system uses Elliptic Curve Cryptosystem to accomplish.

碩士
銘傳大學
管理研究所碩士在職專班
95
In the developed countries, IC card now widely applies in the traffic, communication etc. The application grows up fast and it developed in the retailing little by little. Now the trades of the retailing still pay in cash. Especially the trades of the convenience stores are the type of the little-money-many-times. In the type, it is unfit for credit card. If we use IC saving card for paying in the retailing, it is very fine for the retailing and consumers. Because the paying method has the advantages of low-cost, safety, convenience and so on. The study begins with the retailing operation, changes, future of our country, then understands the business application of the IC card. And the study bases on the need of consumers, stores and banks to explore, then finds the application and operating model of IC card in the convenience stores. In the end, the study summaries the integrated paying usefulness of IC card in our country. In recent years, the development and commercial application of IC card have shown promising growth in the industries of transportation, telecommunication, etc. As for in the retail industry, paying by cash is still the dominant method; especially in the convenience stores, huge quantity of transactions with small amount makes payment via credit card or ATM card inconvenient. The application of paying via low-cost IC card with the aims of security and convenience will bring great benefit to the retail industry and the customers alike. The purpose of this study was to investigate the demand of application of e-wallet in domestic retail industry by examining the needs of adoption of small amount paying method and the reasons for customers’ using of IC stored value card in this industry and aimed at providing suggestions on the e-development of small amount paying methods for domestic retail and banking industries. The report starts with the introduction to easy card with credit option and the commercial applications of IC card, and then goes on to the research of demands of customers, retail industry and baking sector. Finally the report leads to the results of the questionnaire investigating the effects of variables of population poll and life style on the adoption of easy card/e-money. The results showed that among the population poll variables, except for the “educational level”, there were no obvious differences. In the study of credit card usage behavior, “Have you already applied for an easy card with credit option or do you already possess one”, “Are you accustomed to paying via credit cards”, “Are you considering applying for an easy card with credit option” and “How much amount of e-wallet will you purchase” were closely related. Customers’ degree of acceptance to easy card with credit option/e-wallet was highly affected by each individual’s acknowledgement of “easy-to-use and compatibility” and “consequences and risk estimation”; the higher the “easy-to use and compatibility”, the higher the willingness to apply for it; the higher “consequences and risk estimation”, the lower the willingness to apply for one. As for the study of the life style variables, it could be divided into “diligent and studious” and “trendy and creative” categories. For the “trendy and creative” category, the “easy-to-use and compatibility” was the prior concern for considering the usage of e-wallet, which was a match to the characteristics of trend pursuing and innovation driven; on the contrary, the “diligent and studious” category was comparatively more conservative in that the people in this category took greater concern over the matter of missing of the card and the re-application procedure which were accounted to the “consequences and risk estimation”.

碩士
國立雲林科技大學
資訊管理系
108
With the advance of technology, the global economic and payment method has been changed dramatically. On 18 October 2013, Taobao Website, a leading online shop in China has been launched a brand new payment method called Alipay, in which plays an important role in the advance of payment method in China in following years. Following with the success in China, Taiwan launches its remote payment method in recent years after solving of law issue.But compare with the success in China, Taiwan seems to face the difficulty in promoting this brand-new payment method mainly for the following two reasons. First, the traditional purchasing habit in Taiwan is mainly using NFC Contact payment method (Easy-Card). Second, unlike Chinese government, Taiwan lacks of support in promoting the remote payment method thus leading the public refuse to use the new technology.This research focuses on using status quo bias theory in investigating the reason behind of slowly developing remote buying method in Taiwan.

碩士
朝陽科技大學
企業管理系
107
In recent years, global non-cash transaction volumes continued to proliferate. Third-party payment, mobile payment, and e-wallet have become conventional payment methods for online shopping customers in e-commerce platforms. Since the change of external environment, Vietnam also began to promote non-cash transaction plan through e-payment systems. Especially, e-wallet has many service items to help users trade easier, suitable to help Vietnamese in the first step to accept non-cash transactions. Therefore, this present study investigates the service quality of e-wallet in Vietnam by applying the Kano and Refined Kano model to classify e-wallet’s service quality. Moreover, this study uses Importance-Satisfaction Model (IS Model) to organize the service quality factors, and measure the improvement factors, sort the service items that should be prioritized for improvement. Through the research, “E-Wallet always shows the use of personal data registered by customers” and “Service items for e-wallet with living expenses and leisure activities to purchase tickets”, such services are classify into the one-dimension quality and indifferent quality in Kano model; classify into the high value-added quality and the potential quality with high degree of importance in Refined Kano model. After calculation of Improvement Index, these two services are in line of the top 5 services improvement needed list. Based on empirical results, this study offers some suggestions for organizers to improve service quality, save costs and achieve the optimized goal of service quality.

CEMS
This Business Project, conducted in coorporation with MasterCard during my CEMS semester at Corvinus University Budapest, tackles the question of “what are the main obstacles for the (mass) adoption of mobile wallets?” The object of this project was to define and analyse all arguments against a successful mass adoption – regardless of the technology behind it. As a final output, we defined three major threats to the mobile wallet – concerns about Big Data, apprehension to adopt as well as consumer connectivity – and developed a scoring model enabling the company to quickly assess the level of severity of a certain counterargument.

碩士
國立中興大學
科技管理研究所
107
Nowadays, the purchase behavior is different from previously because of technology has become the part of current’s people live in every day, along with, the internet users have been increasing today worldwide. In recent years, the payments have been developing in various way to satisfying modern lifestyle. Likewise, in current, the payments have a new way to spend money is electronic payment it can make it easy for payment. Electronic payment is one of fin-tech that make it more convenient to spend money, and they have many ways to use, such as website and application on a smartphone, computer, laptop. These days, electronic payment is becoming more critical in money transactions such as online transfer money, shopping, pay a bill. Furthermore, Electronic payment in Thailand is rapidly growing in recently. From a survey of VISA found that many Thai people change their behavior to use e-Payment more and carry less money in the wallet for security. So that the objective of this research explores and understand factors influencing consumer’s intention to use the E-payment system and based on The unified theory of acceptance and use of technology (UTAUT) model. There collect data by the online survey through Google form. The survey was conducted on January 1, 2019 to April 19, 2019 and propagate to social network website Facebook. The sample size, there are 284 of total respondents, only 282 respondents were useable while the other 2 respondents were unable. Then we use SPSS to analysis the result by multiple linear regression methods. The result of this research to provide the relationships and test the hypotheses between Determinants and Moderators in the research model. So that all of the hypotheses have positive significant because all variable in this study affects the intention to use electronic payment.

CEMS
Having been approached by Millennium bcp with the challenge of defining what should the role of the bank in the future of the Portuguese Mobile Payments arena, this document proceeds to reflect on the work done during the project, as well as summarizing key insights from it.

The innovation of mobile Internet technology and the expansion of IT infrastructure boosted the rapid development of the Internet-based financial management industry, which is gradually raising importance in the Chinese financial system. Growing up with economic prosperity and advance in IT technology and exhibiting specific personality characteristics, the Chinese post-90s generation is expected to significantly shift the consumption landscape. Understanding their digital consuming behaviours can help the decision-making process in the Internet financial management industry. Therefore, this study intends to explore the factors influencing the purchasing behaviour of the Chinese post-90s generation in the context of the Internet financial management industry. Based on the relevant literature, this study developed a new conceptual model that includes the latent variables perceived usefulness, perceived ease of use, subjective norm, perceived risk (functional and emotional), trust and behavioural intention. This study targeted the WeChat Wallet as research context. Survey data was collected from a sample of 324 Chinese post-90s consumers in Beijing and the model was tested using Partial Least Squares Path Modelling. The results of this study revealed that all hypotheses are verified, and gender and enterprise scale and reputation are relevant model moderators. This study provides an in-depth understanding of the main determinants of the intention to use internet-based financial products. Moreover, the results of this study also offer managerial implications for the industry, the Government and the post-90 consumers.
A inovação da tecnologia da Internet móvel e a expansão da infraestrutura de TI impulsionaram o rápido desenvolvimento da indústria de financeira digital, que tem ganho importância crescente no sistema financeiro chinês. Crescendo num cenário de prosperidade económica e avanços na tecnologia de TI e possuindo características específicas de personalidade, a geração chinesa que nasceu no pós-90 irá mudar significativamente o cenário de consumo. Este estudo pretende identificar os fatores que influenciam o comportamento de compra da geração chinesa nascida no pós-90 na indústria financeira digital. Com base na literatura académica relevante, este trabalho desenvolveu um modelo conceptual inovador, que inclui as variáveis latentes utilidade percecionada, facilidade de uso percecionada, norma subjetiva, risco percecionado (funcional e emocional), confiança e intenção comportamental. Este estudo considerou como contexto de estudo os serviços oferecidos pelo WeChat Wallet. Os dados da pesquisa foram recolhidos através de um questionário, respondido por uma amostra de 324 consumidores chineses nascidos pós-90, em Pequim, e o modelo foi estimado usando o método Partial Least Squares Path Modeling. Os resultados deste estudo revelaram que todas as hipóteses são verificadas e o género, a dimensão e a reputação empresarial são variáveis moderadores relevantes no modelo proposto. Este estudo fornece uma compreensão aprofundada dos principais determinantes da intenção de utilização de produtos financeiros digitais. Além disso, os resultados deste estudo também oferecem implicações práticas para a indústria, o Governo e os consumidores pós-90.

Purpose. The objective is to understand how the digital transformation in the banking sector can foster financial inclusion. Besides, the study addresses the main concepts of the digital economy, digital transformation, FinTech, and we will focus on financial inclusion and their issues. Besides, it is interesting to understand through real business cases how advances in technology can also benefit disadvantaged target groups. This study will concentrate on Peru because it is considered one of the leading emerging markets in South America. However, it has one of the lowest rates of financial inclusion in the region. Therefore, we will analyse the specific case of BIM mobile wallet, which aims to reach the unbanked people. Method. The method used was the qualitative analysis of content with the intention of understanding and identified the main drivers of the digital transformation, its opportunities and impact on financial inclusion. Moreover, the case study methodology was chosen to develop insights and to make a depth description of BIM. In addition, a questionary and interview were also designed to complement the study. Findings. The technological revolution in the financial sector has led to the emergence of FinTech, whose products can be used to reach and serve the unbanked and thus promote financial inclusion. Research limitations. There is still not enough academic information about the use of new technologies to promote financial inclusion in Latin America, because the topic is still new in the region, especially in Peru. Originality/value. This study contributes to the academic literature, first, by offering an overview of the available knowledge about digital transformation in the financial sector and financial inclusion; secondly, by analysing the situation of financial inclusion in Peru and the specific case of BIM.
Objetivo. O objetivo é entender como a transformação digital no setor bancário pode promover a inclusão financeira. Além disso, o estudo aborda os principais conceitos de economia digital, transformação digital, FinTech, e focaremos na inclusão financeira e seus problemas. Além disso, é interessante entender através de casos reais de negócios como os avanços na tecnologia também podem beneficiar grupos-alvo desfavorecidos. Este estudo se concentrará no Peru, pois é considerado um dos principais mercados emergentes da América do Sul. No entanto, possui uma das taxas mais baixas de inclusão financeira na região. Portanto, analisaremos o caso específico da carteira móvel BIM, que visa atingir as pessoas não-bancárias. Método. O método utilizado foi a análise qualitativa do conteúdo, com o intuito de compreender e identificar os principais direcionadores da transformação digital, suas oportunidades e impacto na inclusão financeira. Além disso, a metodologia do estudo de caso foi escolhida para desenvolver insights e fazer uma descrição detalhada do BIM. Além disso, também foram elaborados um questionário e uma entrevista para complementar o estudo. Constatações. A revolução tecnológica no setor financeiro levou ao surgimento da FinTech, cujos produtos podem ser usados para alcançar e servir os não bancários e, assim, promover a inclusão financeira. Limitações de pesquisa. Ainda não há informações acadêmicas suficientes sobre o uso de novas tecnologias para promover a inclusão financeira na América Latina, porque o tema ainda é novo na região, especialmente no Peru. Originalidade / valor. Este estudo contribui para a literatura acadêmica, primeiramente, oferecendo uma visão geral do conhecimento disponível sobre transformação digital no setor financeiro e inclusão financeira; segundo, analisando a situação da inclusão financeira no Peru e o caso específico do BIM.

碩士
真理大學
財經研究所
96
This paper’s purpose is to identify how a built-in payment function, like Easy-Card, which gives the cardholders of one e-wallet system, called Easy-Pay, a more convenient way for paying public transport fees affects the competition structure in a duopoly e-wallet industry. We consider in turn the case of both systems incompatible, the case of both systems partially compatible, and the case of both systems fully compatible. There are several results as follows. First, when both systems are incompatible with each other, the equilibrium utility of Easy-Pay’s cardholders is less than the equilibrium utility of cardholders of the e-wallet system having no such built-in payment function. Second, among the three cases, the total social welfare is the largest when both systems are compatible, whereas the total surplus of cardholders of both systems is the largest when both systems are partially compatible.

Dissertação de mestrado em Estudos Interculturais Português/Chinês: Tradução, Formação e Comunicação Empresarial
As carteiras digitais estão cada vez mais presentes no nosso dia a dia, podendo ser utilizadas em cada vez mais ocasiões. Na China, as carteiras digitais têm, desde há uns anos, uma forte presença na vida quotidiana da população, englobando inúmeras funções e podendo ser usadas em diversas ocasiões durante o dia a dia. Por outro lado, em Portugal, o uso de carteiras digitais está ainda em crescimento, sendo que o número de funções destas é ainda limitado. Esta dissertação analisa e compara as carteiras digitais usadas na China e em Portugal, o seu crescimento, as suas funções e os consequentes os impactos na sociedade e ambiente. Para além disso, através do modelo das dimensões culturais de Hofstede, tenta-se perceber o porquê das diferenças na velocidade de adoção desta tecnologia na China e em Portugal.
Digital wallets are increasingly present in our everyday lives, in which people are able to use them in more and more situations. In China, digital wallets have had a heavy presence for a few years now, offering a wide range of functions, where people can use them in different occasions throughout their day. On the other hand, in Portugal, the use of digital wallets is still developing and the number of functions they offer is still limited. This dissertation analyses and compares digital wallets used in China and Portugal, as well as their functions and the consequent impacts on society and the environment. Moreover, through Hofstede’s model of cultural dimensions, there is a search to understand the reasons behind the difference in the pace of adoption of this new technology in China and in Portugal.
当今社会，随着第 方支付越发普及，在大部分情况 ，人们都可以使用第 方支付的方式 在中国，近几年来，电子钱包几乎成 了人们生活的必备品 多 能的电子钱包可以在餐厅，商场，交通系统，电子商 等多处进行消费 但 反观葡萄牙，电子钱包的使用 然处在发展状态中，其 能 十分有限. 本论文将对中国和葡萄牙的第 方支付方式进行对比，内容 要体 在两国 第 方支付的发展， 它的 能 生活影响和 境影响 几个方面 以分析 除 此之外，基于霍夫斯泰德的文化维度模式，尝试探讨中葡两国在对电子钱包的使 用普及度 有明显区别的原因

With the growth of the e-commerce industry in Brazil, companies have started to invest in new technologies in order to create more user-friendly interfaces. The COVID-19 pandemic has boosted the digital payment industry, and more and more, new consumers are attracted by the e-wallet conveniences every day. This study tests the concept of e-wallets applications contributing to the adoption of e-commerce among Brazilians. In this sense, the barriers and motivations of the present business were studied. Data was collected and 275 valid responses obtained. The Spearman's Correlation and Logit Regression was performed. The first one to measure correlations between variables and the second one to study the causality effects between the dependent and independent variables. Thus, being able to validate hypothesis. Findings suggest that the intention to transact has a significant correlation with perceived usefulness, perceived ease of use and trust, meanwhile, trust has significant correlation with perceived risk of e-wallets. However, regression tests reveal perceived ease of use and usefulness as the only significant motivations that influence the effects on users´ future intentions. Moreover the study support the potential contribution of e wallet to the adoption of e-commerce among Brazilians pointing out usefulness and easiness as the key elements to be worked out by managers.
Com o crescimento da indústria de e-commerce no Brasil, empresas começaram a investir em novas tecnologias com o objetivo de criar interfaces mais simples de serem usadas. A pandemia do COVID-19 impulsionou a indústria do pagamento digital e mais consumidores foram atraídos pela conveniência das carteiras digitais. Este estudo testa o conceito de carteiras digitais contribuírem para adoção do e-commerce entre brasileiros. Assim, percebe-se que há barreiras e motivações presentes nesse negócio que está sendo estudado. A base de dados foi coletada e 275 respostas válidas foram obtidas. Os resultados foram analisados usando o teste de Correlação de Spearman para identificar a relação entre duas variáveis, seguido do teste de Regressão Logística para validar as hipóteses. Os resultados sugerem que a intenção de transacionar tem correlação significativa como percepção de utilidade, percepção de facilidade de uso, e confiança. E a percepção de risco das carteiras digitais tem uma correlação positiva com a confiança. Entretanto, a regressão mostra que percepção de utilidade e percepção de facilidade de uso são os únicos motores motivacionais que influenciam o uso futuro do aplicativo. Além disso, esse estudo acredita que as carteiras digitais apresentam uma potencial contribuição para a adoção do e-commerce dentre os brasileiros, devido a percepção de facilidade e utilidade do aplicativo.

In this work, cellulose-based electro and ionic conductive composites were developed for application in cellulose based printed electronics. Electroconductive inks were successfully formulated for screen-printing using carbon fibers (CFs) and multi-walled carbon nanotubes (MWCNTs) as conductive functional material and cellulose derivatives working as binder. The formulated inks were used to fabricate conductive flexible and disposable electrodes on paper-based substrates. Interesting results were obtained after 10 printing passes and drying at RT of the ink with 10 % wt. of pristine CFs and 3% wt. of carboxymethyl cellulose (CMC), exhibiting a resistivity of 1.03 Ωcm and a resolution of 400 μm. Also, a resistivity of 0.57 Ωcm was obtained for only one printing pass using an ink based on 0.5 % wt. MWCNTs and 3 % wt. CMC. It was also demonstrated that ionic conductive cellulose matrix hydrogel can be used in electrolyte-gated transistors (EGTs). The electrolytes revealed a double layer capacitance of 12.10 μFcm-2 and ionic conductivity of 3.56x10-7 Scm-1. EGTs with a planar configuration, using sputtered GIZO as semiconducting layer, reached an ON/OFF ratio of 3.47x105, a VON of 0.2 V and a charge carrier mobility of 2.32 cm2V-1s-1.

Using perfluoropolyether as the solvent, cutting of pristine SWNT has been achieved by extensive ozonolysis with 80% carbon yield at room temperature. The intense disorder mode in the Raman spectra of ozonated SWNT indicates that extensive reaction with the sidewalls of SWNT occurs during ozonolysis. AFM provided a measure of the extent of the cutting effects. Monitoring of the evolved gases indicates CO2 was produced during the ozonolysis process with a dependence on both system pressure and temperature. During heating, FTIR analysis of gases released indicates carbon oxygen groups on the sidewalls of SWNT are released as CO2. Room temperature ozonolysis of fluorinated SWNT and phenol-sulfonated SWNT have also been studied in PFPE. For fluorinated SWNT, etching at the end caps has been demonstrated to be the dominating effect during this process. The improved suspension in 96% sulfuric acid after ozonolysis enables the cutting by ammonia peroxydisulfate without defluorination with a hydrazine treatment. PS-SWNT was found to be effectively cut by ozonolysis in a water suspension with preserved water solubility. Controlled by the electron dosage, a high energy electron beam (3MeV) has been demonstrated to cut ozonated SWNT. Besides ozonolysis, 700°C has been shown an optimal temperature to cut F-SWNT by pyrolysis in an argon atmosphere.

Dissertação de Mestrado Integrado em Engenharia Civil apresentada à Faculdade de Ciências e Tecnologia
The bending rigidities in the main plane of lesser inertia and torsion of the thin-walled open section profiles are reduced, which causes them to exhibit low vibration frequencies in the lateral bending and torsion modes. The influence of the internal stresses (initial tensions) on the natural frequencies and modes of vibration of these structures are a relevant issue in the design and verification of their safety. In order to obtain results of practical interest, a one-dimensional mathematical model is presented for the influence of the initial stresses (generalized tensions) on the vibration by lateral flexion and twisting of thin-walled I-beams, of equal flanges (double symmetrical section) or unequal (monosymmetric section).The model was based on the classical hypotheses of Vlasov (1961) for the non-uniform twist, which allow to realize the required dimensional reduction, neglecting the distortions by shear strenght and considering the effects of the inertia associated with the rotation of the cross sections around its weak axis and inertia associated with twist warpage. The equations of motion (partial differential equations) and boundary conditions are established through Hamilton's variational principle. The technique of separating variables allows us to define a problem of values and proper functions (with ordinary differential equations), which provides the own frequencies and modes of vibration.As you would expect, the vibration frequency itself decreases as the initial stress increase.
As rigidezes de flexão no plano principal de menor inércia e de torção dos perfis de secção aberta de parede fina são reduzidas, o que faz com que apresentem baixas frequências próprias de vibração nos modos de flexão lateral e torção. A influência dos esforços internos (tensões iniciais) nas frequências próprias e modos de vibração destas estruturas, são uma questão relevante na conceção, dimensionamento e verificação da segurança das mesmas. Por forma a tirar resultados de interesse prático, apresenta-se um modelo matemático unidimensional para a influência dos esforços iniciais (tensões generalizadas) na vibração por flexão lateral e torção de vigas com secção em I de parede fina, de banzos iguais (secção duplamente simétrica) ou desiguais (secção monossimétrica).O modelo teve por base as hipóteses clássicas de Vlasov (1961) para a torção não uniforme, as quais permitem efetuar a redução dimensional requerida, desprezando as distorções por esforço transverso e considerando os efeitos da inércia associada à rotação das secções transversais em torno do seu eixo fraco e da inércia associada ao empenamento por torção. As equações do movimento (equações diferenciais parciais) e as condições de fronteira são estabelecidas através do princípio variacional de Hamilton. A técnica da separação de variáveis permite definir um problema de valores e funções próprios (com equações diferenciais ordinárias), que fornece as frequências próprias e os modos de vibração.Tal como seria de esperar, a frequência própria de vibração diminui à medida que as tensões iniciais aumentam.

Der elektrochemische Nachweis von polycyclischen aromatischen Kohlenwasserstoffen (PAK), zu denen Anthracen und Pyren gehören, bietet eine kostengünstigere, einfachere und schnellere alternative Analysemethode als herkömmliche Methoden wie GC und HPLC. Im Vergleich zu diesen Methoden weist er jedoch nach wie vor eine geringere Empfindlichkeit auf. Einige neuere Bemühungen haben an einem Mangel an Selektivität gelitten, entweder aufgrund der elektrodenmodifizierende Schicht mit hohem Hintergrundstrom oder der Wahl eines Leitelektrolyten, der die Detektion stört. Bei dem vorliegenden Versuch wurden Pt-Pd-Nanopartikel (NPs) und MWCNTs verwendet, um eine Glaskohlenstoffelektrode (GCE) zum empfindlichen Nachweis von Anthracen und Pyren zu modifizieren. Die verwendeten NPs wurden unter Verwendung eines wässrigen Extrakts aus Blättern von E. grandis synthetisiert, einem nachhaltigen und umweltfreundlichen Syntheseweg. Durch einer Optimierung der Mengen an Pt- und Pd-Ionen im Vorläufer wurden NPs mit einer durchschnittlichen Größe von 10 nm erhalten, wobei ein Verhältnis von 1 Pt-Ion zu 3 Pd-Ionen die kleinste Größe ergab. Durch XPS wurde festgestellt, dass die Zusammensetzung der NPs von Pt2+ und Pd0 dominiert wird. Die XRD-Analyse ergab eine kristalline Natur mit einer flächenzentriert-kubischen Struktur. Die Pt-Pd-NPs bewirkten eine Erhöhung des Spitzenstroms um 94 % für Pyren, führten jedoch zu niedrigeren Spitzenströmen für Anthracen. Wenn die NPs weiter mit MWCNTs zum Nachweis von Pyren verwendet wurden, wurde eine Spitzenstromsteigerung von etwa 200 % mit einem Dynamikbereich von 66–130 μM und einer LOD von 23 μM beobachtet. Es wurde auch festgestellt, dass der elektrochemische Prozess gemischt diffusions- und adsorptionskontrolliert ist. Aufgrund des Einflusses der Adsorption musste die Akkumulationszeit im Analyseverfahren berücksichtigt werden. MWCNTs wurden beim Nachweis von Anthracen angewendet, wobei eine Erhöhung des Spitzenstroms um 74 % und eine Verringerung des Überpotentials um 53 mV beobachtet wurde. Ein dynamischer Bereich von 50–146 µM und eine LOD von 42 µM wurden bestimmt. Niedrigere Konzentrationen wurden mit einer Leitungswasserprobe gemessen, die mit Anthracen versetzt war, hauptsächlich wegen der geringen Löslichkeit von PAK in Wasser. Der Einfluss der Säurebehandlung von MWCNTs auf den Nachweis von Anthracen und Pyren wurde ebenfalls untersucht. Die Säurebehandlung ermöglichte das Laden von mehr Material ohne Ablösen der modifizierten Schicht, was zu höheren Spitzenstromverbesserungen für Anthracen (533 %) und Pyren (448 %) führte. Für Anthracen und Pyren wurden LODs von 40 µM bzw. 14 µM bestimmt, die nur geringfügig niedriger sind als die bei MWCNTs/GCE und Pt-PdNPs/MWCNTs/GCE beobachteten Werte. Der Nachweis von Anthracen wurde durch die Anwesenheit von Pyren und gewöhnlichen Ionen gestört, während die LOD für Pyren in Gegenwart von Anthracen 18 µM betrug. Es wurde festgestellt, dass die auf MWCNTs basierende elektrochemische Nachweisplattform eine bessere Reaktion auf Pyren aufweist.:Bibliographische Beschreibung i Referat i Abstract iii Zeitraum, Ort der Durchführung v Acknowledgements vi Dedication vii Table of Contents viii List of Abbreviations and Symbols xii Chapter 1 1 Introduction 1 1.1 Overview 1 1.2 Polycyclic Aromatic Hydrocarbons 2 1.3 Electrochemical Sensors 7 1.3.1 General Response Curve for Chemical Sensors 10 1.4 Carbon Nanotubes 13 1.5 Use of Nanoparticles in Electrochemical Detection 18 1.6 Green Synthesis of Nanoparticles and The Rationale Behind It 21 1.7 Previous Efforts in the Electrochemical Detection of Polycyclic Aromatic Hydrocarbons 24 1.8 Objectives of the Study 26 Chapter 2 28 Experimental 28 2.1 Chemicals 28 2.1.1 Preparation of Anthracene and Pyrene Solutions 28 2.2 Collection and Preparation of Plant Material 29 2.3 Synthesis and Preparation of Materials 29 2.3.1 Synthesis of Metallic Nanoparticles 29 2.3.2 Acid Treatment of Multi-walled Carbon Nanotubes 30 2.4 Characterization of the Nanomaterials 30 2.4.1 UV-Vis Spectrophotometry 30 2.4.2 SEM/EDX and TEM Analysis 30 2.4.3 Powder X-ray Diffractometry 31 2.4.4 XPS Analysis 31 2.5 Electrochemical Measurements 31 2.5.1 Preparation of the Bare and Modified Glassy Carbon Electrode 32 2.5.2 Characterization of the Bare and the Modified Glassy Carbon Electrode 33 2.5.3 Electrocatalytic Oxidation of Anthracene on the Bare and Modified GCEs 33 2.5.4 Electrocatalytic Oxidation of Pyrene on the Bare and Modified GCEs 34 Chapter 3 35 Synthesis, Characterization, and Application of Pt-Pd Nanoparticles in the Electrochemical Detection of Anthracene and Pyrene 35 3.1 Test for Flavonoids and Polyphenols in the E. grandis Leaves’ Extract 35 3.2 Synthesis of Nanoparticles 35 3.3 Characterization of Nanoparticles 37 3.3.1 TEM Analysis 37 3.3.2 SEM Analysis 40 3.3.3 EDX Analysis 41 3.3.4 Powder X-Ray Diffraction Analysis 45 3.3.5 XPS Analysis of Pt-Pd Particles 46 3.4 Impedance Measurements of the Bare and Nanoparticle-modified Glassy Carbon Electrode 49 3.5 Electrochemical Oxidation of Anthracene and Pyrene at the Bare and Nanoparticles-modified Glassy Carbon Electrode 51 3.6 Conclusions 53 Chapter 4 55 Pt-PdNPs/MWCNTs-Modified GCE for the Detection of Pyrene 55 4.1 Impedance Measurement with Pt-PdNPs/MWCNTs/GCE 55 4.2 Electrochemical Oxidation of Pyrene on Pt-PdNPs/MWCNTs/GCE 56 4.3 Analysis of Varying Concentrations of Pyrene on Pt-PdNPs/MWCNTs/GCE 59 4.4 Selectivity 61 4.5 Conclusions 62 Chapter 5 64 Exploring Multi-walled Carbon Nanotubes for the Detection of Anthracene 64 5.1 Impedance Measurement of MWCNT-Modified Glassy Carbon Electrode 64 5.2 Electrochemical Oxidation of Anthracene on MWCNT/GCE 65 5.3 Analysis of Varying Concentrations of Anthracene Using MWCNTs/GCE 68 5.4 Detection of Anthracene in Tap Water 71 5.5 Conclusions 72 Chapter 6 73 Effect of Acid Treatment of Multi-walled Carbon Nanotubes on the Detection of Anthracene and Pyrene 73 6.1 Characterization of fMWCNTs 74 6.2 Electrochemical Oxidation of Anthracene on fMWCNTs/GCE 75 6.2.1 Effect of Change in Scan Rate 76 6.2.2 Effect of Accumulation Time 77 6.2.3 Application of fMWCNTs/GCE in the Analysis of Varying Concentrations of Anthracene 77 6.3 Electrochemical Oxidation of Pyrene on fMWCNTs/GCE 79 6.4 Selectivity 82 6.4.1 Co-detection of Anthracene and Pyrene at fMWCNTs/GCE 83 6.4.2 Interference of Some Common Ions 85 6.5 Detection of Pyrene in Tapwater using fMWCNTs/GCE 86 6.6 Conclusions 87 Chapter 7 88 Summary and Outlook 88 7.1 Summary 88 7.2 Outlook 90 References 92 Selbständigkeitserklärung 101 Curriculum Vitae 102
Electrochemical detection of polycyclic aromatic hydrocarbons (PAHs), which include anthracene and pyrene, offers a cheaper, simpler, and faster alternative method of analysis than conventional methods like GC and HPLC. However, it still is not as sensitive as these methods. Some recent efforts have suffered from lack of selectivity, either from the electrode modifying layer having high background current or from the choice of supporting electrolyte interfering with the detection. In this work, Pt-Pd nanoparticles (NPs) and MWCNTs were used to modify a glassy carbon electrode (GCE) for sensitive detection of anthracene and pyrene. The NPs used were synthesized using an aqueous extract from E. grandis leaves, a sustainable and environmentally friendly synthetic route. NPs with an average size of 10 nm were obtained by optimizing the amounts of Pt- and Pd-ions in the precursor, with a ratio of 1:3 Pt to Pd-ions producing the smallest size. Through XPS, the composition of the NPs was established to be dominated by Pt2+ and Pd0. XRD analysis revealed a crystalline nature with a face-centered cubic structure. The Pt-Pd NPs produced 94 % enhancement in the peak current for pyrene but resulted in lower peak currents for anthracene. When the NPs were further used with MWCNTs for the detection of pyrene, about 200% peak current enhancement was observed with a dynamic range of 66–130 µM and LOD of 23 µM. The electrochemical process was also established to be mixed diffusion- and adsorption-controlled. The influence of adsorption necessitated the employment of accumulation time in the analysis procedure. MWCNTs were applied in the detection of anthracene and a 74 % peak current enhancement and a reduction in the overpotential by 53 mV were observed. A dynamic range of 50–146 µM and LOD of 42 µM were determined. Lower concentrations were recovered from a tap water sample that was spiked with anthracene, mainly because of the low solubility of PAHs in water. Effect of acid treatment of MWCNTs on the detection of anthracene and pyrene was also investigated. Acid treatment allowed for loading of more material without peeling off of the modified layer which resulted in higher peak current enhancements for anthracene (533%) and pyrene (448%). LODs of 40 µM and 14 µM were determined for anthracene and pyrene respectively, which are only slightly lower than what was observed at MWCNTs/GCE and Pt-PdNPs/MWCNTs/GCE. Detection of anthracene was interfered by the presence of pyrene and common ions, while the LOD for pyrene in the presence of anthracene was 18 µM. The MWCNTs based electrochemical detection platform was found to have a better response towards pyrene.:Bibliographische Beschreibung i Referat i Abstract iii Zeitraum, Ort der Durchführung v Acknowledgements vi Dedication vii Table of Contents viii List of Abbreviations and Symbols xii Chapter 1 1 Introduction 1 1.1 Overview 1 1.2 Polycyclic Aromatic Hydrocarbons 2 1.3 Electrochemical Sensors 7 1.3.1 General Response Curve for Chemical Sensors 10 1.4 Carbon Nanotubes 13 1.5 Use of Nanoparticles in Electrochemical Detection 18 1.6 Green Synthesis of Nanoparticles and The Rationale Behind It 21 1.7 Previous Efforts in the Electrochemical Detection of Polycyclic Aromatic Hydrocarbons 24 1.8 Objectives of the Study 26 Chapter 2 28 Experimental 28 2.1 Chemicals 28 2.1.1 Preparation of Anthracene and Pyrene Solutions 28 2.2 Collection and Preparation of Plant Material 29 2.3 Synthesis and Preparation of Materials 29 2.3.1 Synthesis of Metallic Nanoparticles 29 2.3.2 Acid Treatment of Multi-walled Carbon Nanotubes 30 2.4 Characterization of the Nanomaterials 30 2.4.1 UV-Vis Spectrophotometry 30 2.4.2 SEM/EDX and TEM Analysis 30 2.4.3 Powder X-ray Diffractometry 31 2.4.4 XPS Analysis 31 2.5 Electrochemical Measurements 31 2.5.1 Preparation of the Bare and Modified Glassy Carbon Electrode 32 2.5.2 Characterization of the Bare and the Modified Glassy Carbon Electrode 33 2.5.3 Electrocatalytic Oxidation of Anthracene on the Bare and Modified GCEs 33 2.5.4 Electrocatalytic Oxidation of Pyrene on the Bare and Modified GCEs 34 Chapter 3 35 Synthesis, Characterization, and Application of Pt-Pd Nanoparticles in the Electrochemical Detection of Anthracene and Pyrene 35 3.1 Test for Flavonoids and Polyphenols in the E. grandis Leaves’ Extract 35 3.2 Synthesis of Nanoparticles 35 3.3 Characterization of Nanoparticles 37 3.3.1 TEM Analysis 37 3.3.2 SEM Analysis 40 3.3.3 EDX Analysis 41 3.3.4 Powder X-Ray Diffraction Analysis 45 3.3.5 XPS Analysis of Pt-Pd Particles 46 3.4 Impedance Measurements of the Bare and Nanoparticle-modified Glassy Carbon Electrode 49 3.5 Electrochemical Oxidation of Anthracene and Pyrene at the Bare and Nanoparticles-modified Glassy Carbon Electrode 51 3.6 Conclusions 53 Chapter 4 55 Pt-PdNPs/MWCNTs-Modified GCE for the Detection of Pyrene 55 4.1 Impedance Measurement with Pt-PdNPs/MWCNTs/GCE 55 4.2 Electrochemical Oxidation of Pyrene on Pt-PdNPs/MWCNTs/GCE 56 4.3 Analysis of Varying Concentrations of Pyrene on Pt-PdNPs/MWCNTs/GCE 59 4.4 Selectivity 61 4.5 Conclusions 62 Chapter 5 64 Exploring Multi-walled Carbon Nanotubes for the Detection of Anthracene 64 5.1 Impedance Measurement of MWCNT-Modified Glassy Carbon Electrode 64 5.2 Electrochemical Oxidation of Anthracene on MWCNT/GCE 65 5.3 Analysis of Varying Concentrations of Anthracene Using MWCNTs/GCE 68 5.4 Detection of Anthracene in Tap Water 71 5.5 Conclusions 72 Chapter 6 73 Effect of Acid Treatment of Multi-walled Carbon Nanotubes on the Detection of Anthracene and Pyrene 73 6.1 Characterization of fMWCNTs 74 6.2 Electrochemical Oxidation of Anthracene on fMWCNTs/GCE 75 6.2.1 Effect of Change in Scan Rate 76 6.2.2 Effect of Accumulation Time 77 6.2.3 Application of fMWCNTs/GCE in the Analysis of Varying Concentrations of Anthracene 77 6.3 Electrochemical Oxidation of Pyrene on fMWCNTs/GCE 79 6.4 Selectivity 82 6.4.1 Co-detection of Anthracene and Pyrene at fMWCNTs/GCE 83 6.4.2 Interference of Some Common Ions 85 6.5 Detection of Pyrene in Tapwater using fMWCNTs/GCE 86 6.6 Conclusions 87 Chapter 7 88 Summary and Outlook 88 7.1 Summary 88 7.2 Outlook 90 References 92 Selbständigkeitserklärung 101 Curriculum Vitae 102

The thesis deals with the emergence of bank and non-bank entities that provide a range of unique transaction-based payment services broadly called Mobile Financial Services (MFS) to unbanked, underserved and underbanked persons via mobile phones. Models of MFS from Mobile Network Operators (MNOs), banks, combinations of MNOs and banks, and independent Mobile Financial Services Providers are covered. Provision by non-banks of ‘bank-type’ services via mobile phones has been termed ‘transformational banking’ versus the ‘additive banking’ services from banks. All involve the concept of ‘branchless banking’ whereby ‘cash-in/cash out’ services are provided through ‘agents.’ Funds for MFS payments may available through a Stored Value Product (SVP), particularly through a Stored Value Account SVP variant offered by MNOs where value is stored as a redeemable fiat- or mobile ‘airtime’-based Store of Value. The competitive, legal, technical and regulatory nature of non-bank versus bank MFS models is discussed, in particular the impact of banking, payments, money laundering, telecommunications, e-commerce and consumer protection laws. Whether funding mechanisms for SVPs may amount to deposit-taking such that entities could be engaged in the ‘business of banking’ is discussed. The continued use of ‘deposit’ as the traditional trigger for the ‘business of banking’ is investigated, alongside whether transaction and paymentcentric MFS rises to the ‘business of banking.’ An extensive evaluation of ‘money’ based on the Orthodox and Claim School economic theories is undertaken in relation to SVPs used in MFS, their legal associations and import, and whether they may be deemed ‘money’ in law. Consumer protection for MFS and payments generally through current statute, contract, and payment law and common law condictiones are found to be wanting. Possible regulatory arbitrage in relation to MFS in South African law is discussed. The legal and regulatory regimes in the European Union, Kenya and the United States of America are compared with South Africa. The need for a coordinated payments-specific law that has consumer protections, enables proportional risk-based licensing of new non-bank providers of MFS, and allows for a regulator for retail payments is recommended. The use of trust companies and trust accounts is recommended for protection of user funds. | vi
Public, Constitutional and International Law
LLD

Tese no âmbito do Doutoramento em Engenharia Civil na Especialidade de Estruturas apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra
The main body of the thesis is divided into two largely self-contained parts. The first one is devoted to the development of a continuous one-dimensional linear model for the stretching, bending and twisting of tapered thin-walled bars with open cross-sections under general quasi-static loading conditions. These bars are treated as two-dimensional Kirchhoff-Love shells, exhibiting both membrane and flexural behaviours. To achieve the necessary dimensional reduction, the classical assumptions of Vlasov and Kirchhoff-Love are regarded systematically as internal constraints, that is, a priori restrictions, of a constitutive nature, on the possible deformations of the bars (alternatively, they may also be viewed as holonomic-scleronomic constraints). Moreover, the internal forces are decomposed additively into active and reactive parts and this is shown to lead to a dual one-dimensional description of kinematics and statics. Two examples illustrate the application of the developed one-dimensional model, shed light on its physical aspects and demonstrate the shortcomings of piecewise prismatic models, regardless of the number of prismatic segments used (indeed, even in the limit when the length of these segments tends to zero). The main original contributions in this first part of the thesis may be summarized as follows: (i) The second fundamental form of the middle surface of a bar and the change of curvature tensor are established in general form. (ii) The displacement field of a whole bar (not just of its middle surface) is completely characterized, thus including the so-called through-the-thickness (or secondary) warping deformation. (iii) In the characterization of the internal forces in the bar, the shell bending and twisting moments and the transverse shear forces are taken into account, in addition to the membrane forces. (iv) The Saint-Venant contribution to the strain energy and the corresponding component of the total torque are derived consistently. (v) A set of fundamental inequalities concerning the cross-sectional properties is established. The second part of the thesis is restricted to the important special case of depth-tapered singly symmetric I-section bars and deals with one-dimensional models of the Hencky bar-chain type, whose nature is intrinsically discrete. Indeed, a Hencky bar-chain model consists of a finite number of rigid units linked by elastic springs (or, more generally, by rheological elements) – it can be thought of not only as an idealization of a (continuous) member, but also as an actual mechanical structure in its own right, the inherent simplicity and transparency of which make its qualitative behaviour more easily grasped. Two types of problem are addressed in successive chapters: (i) the linear mechanical behaviour in three-dimensional space under general quasi-static loading conditions and (ii) the linearized flexural-torsional buckling behaviour under bending (in the plane of symmetry, which is also the plane of greatest flexural rigidity) and compression, including the so-called Wagner effect associated with the asymmetry of the flanges. Particular attention is paid to the calibration of the spring stiffnesses and to the appropriate definition of boundary conditions. It is shown that the bar-chain models are consistent with (but not subordinate to or in any away dependent on) previously developed Vlasov-type continuum models, in the sense that the local truncation errors tend to zero as the length of the rigid units approaches zero. Several illustrative examples, including prismatic and flangeless members (i.e., members with narrow rectangular cross-sections), are solved in order to verify the discrete Hencky bar-chain models and to assess their convergence rates.
Contributos para a Modelação Unidimensional do Comportamento Tridimensional de Barras Não Prismáticas com Secção de Parede Fina Aberta A tese encontra-se dividida em duas partes em larga medida independentes. A primeira é dedicada ao desenvolvimento de um modelo linear unidimensional contínuo para a flexão e torção de barras com secção aberta de paredes finas, continuamente variável, submetidas a carregamentos quase-estáticos genéricos. Estas barras são tratadas como cascas de Kirchhoff-Love (bidimensionais), considerando tanto o comportamento de membrana como o de flexão. Para levar a cabo a necessário redução dimensional, as hipóteses clássicas de Vlasov e Kirchhoff-Love são tratadas sistematicamente como constrangimentos internos, isto é, restrições de natureza constitutiva às possíveis deformações de uma barra (alternativamente, aquelas hipóteses podem também ser vistas como constrangimentos holonómicos-escleronómicos). Assim, as forças internas são decompostas em parcelas activa e reactiva, o que conduz a uma descrição dual (unidimensional) da cinemática e da estática. São apresentados dois exemplos que ilustram a aplicação do modelo unidimensional desenvolvido, esclarecem os seus aspectos físicos e atestam as limitações dos modelos seccionalmente prismáticos (ou “em escada”), independentemente do número de segmentos prismáticos utilizados (de facto, estas limitações mantêm-se mesmo no processo de passagem ao limite quando o comprimento dos segmentos tende a para zero). Os principais contributos originais nesta primeira parte da tese podem ser resumidos da seguinte forma: (i) Obtêm-se expressões gerais para a segunda forma fundamental da superfície média de uma barra e para o tensor de mudança de curvatura (ii) Generaliza-se a definição do campo de deslocamentos da superfície média para todo a barra, incluindo assim a caracterização do empenamento na espessura das paredes (também designado por empenamento secundário). (iii) Na caracterização dos esforços internos, são tidos em consideração não apenas os esforços de membrana, mas também os momentos flectores e de torção e as forças de corte transversais “de casca”. (iv) A contribuição de Saint-Venant para a energia de deformação e a componente correspondente do momento torsor total são obtidas de forma consistente. (v) Estabelece-se um conjunto de desigualdades fundamentais relativas às propriedades mecânicas das secções transversais. A segunda parte da tese, cujo âmbito se restringe ao importante caso particular de barras com secção em I monossimétricas e altura variável, trata de modelos unidimensionais do tipo Hencky, cuja natureza é intrinsecamente discreta. De facto, um modelo de Hencky consiste num número finito de unidades rígidas ligadas por molas elásticas (ou, mais geralmente, por elementos reológicos) e pode ser encarado não apenas como uma idealização de um elemento estrutural contínuo, mas também como uma estrutura real por direito próprio. A sua simplicidade e transparência faz com que o seu comportamento, de um ponto de vista qualitativo, seja mais facilmente apreendido. São abordados dois tipos de problema em capítulos sucessivos: (i) o comportamento linear no espaço tridimensional, sob acções quase-estáticas genéricas e (ii) a encurvadura por flexão-torção (linearizada) de vigas e colunas-viga solicitadas à flexão no seu plano de simetria (que é também o plano de maior rigidez à flexão), incluindo o chamado efeito Wagner associado à assimetria dos banzos. É dada uma especial atenção à calibração das rigidezes da mola e à definição apropriada das condições de fronteira. Mostra-se que os modelos de Hencky, se bem que desenvolvidos de forma totalmente independente, são consistentes com modelos contínuos do tipo Vlasov previamente desenvolvidos, na medida em que os erros de truncatura locais tendem para zero à medida que o comprimento das unidades rígidas também se aproxima de zero. Apresentam-se vários exemplos ilustrativos, que incluem elementos prismáticos e elementos de secção rectangular fina, de forma a verificar os modelos discretos de Hencky e avaliar as suas taxas de convergência.