Location-dependent services for mobile users

Abstract—One of the main issues in mobile services ’ research (M-service) is supporting M-service availability, regardless of the user’s context (physical location, device employed, etc.). However, most scenarios also require the enforcement of context-awareness, to dynamically adapt M-services depending on the context in which they are requested. In this paper, we focus on the problem of adapting M-services depending on the users ’ location, whether physical (in space) or logical (within a specific distributed group/application). To this end, we propose a framework to model users ’ location via a multiplicity of local and active service contexts. First, service contexts represent the mean to access to M-services available within a physical locality. This leads to an intrinsic dependency of M-service on the users’ physical location. Second, the execution of service contexts can be tuned depending on who is requesting what M-service. This enables adapting M-services to the logical location of users (e.g., a request can lead to different executions for users belonging to different groups/applications). The paper firstly describes the framework in general terms, showing how it can facilitate the design of distributed applications involving mobile users as well as mobile agents. Then, it shows how the MARS coordination middleware, implementing service contexts in terms of programmable tuple spaces, can be used to develop and deploy applications and M-services coherently with the above framework. A case study is introduced and discussed through the paper to clarify our approach and to show its effectiveness. Index Terms—Context-awareness, coordination infrastructures, M-services, mobility, multiagent systems. I

Towards User-Aware Service Composition

Our everyday life is more and more supported by the information technology in general and specific services provided by means of our electronic devices. The AMBIT project (Algorithms and Models for Building context-dependent Information delivery Tools) aims at providing a support to develop services that are automatically tailored based on the user profile. However, while the adaptation of the single services is the first step, the next step is to achieve adaptation in the composition of different services. In this paper, we explore how services can be composed in a user-aware way, in order to decide the composition that better meets users’ requirements. That is, we exploit the user profile not only to provide her customized services, but also to compose them in a suitable way

AMBIT: Semantic Engine Foundations for Knowledge Management in Context-dependent Applications

Context-aware application and services proposing potentially useful information to users are more and more widespread; however, their actual usefulness is often limited by the “syntactical” notion of context they adopt. The recently started AMBIT project aims to provide a general software architecture for developing semantic-based context-aware tools in a number of vertical case study applications. In this paper, we focus on the knowledge management foundations we are laying for the Semantic Engine of the AMBIT architecture. The proposed semantic analysis and similarity techniques: (a) exploit the textual information deeply characterizing both users and the information to be retrieved; (b) overcome the limits of syntactic methods by leveraging on the strengths of both classic information retrieval and knowledge-based analysis and classification, ultimately proposing information relevant to the user interests. The experimental evaluation of a preliminary implementation in an actual “cultural territorial enhancement” scenario already shows promising results

Toward Collinearity-Avoidable Localization for Wireless Sensor Network

In accordance with the collinearity problem during computation caused by the beacon nodes used for location estimation which are close to be in the same line or same plane, two solutions are proposed in this paper: the geometric analytical localization algorithm based on positioning units and the localization algorithm based on the multivariate analysis method. The geometric analytical localization algorithm based on positioning units analyzes the topology quality of positioning units used to estimate location and provides quantitative criteria based on that; the localization algorithm based on the multivariate analysis method uses the multivariate analysis method to filter and integrate the beacon nodes coordinate matrixes during the process of location estimation. Both methods can avoid low estimation accuracy and instability caused by multicollinearity

Modelos computacionales y metodologías utilizadas en la detección del fraude de las tarjetas de crédito

De la mano de la evolución del comercio electrónico ha devenido el incremento en el uso de las tarjetas de crédito (TC) para realizar compras habituales en internet, y como consecuencia, se ha dado a lugar al incremento del fraude sobre las mismas, llamado fraude online. La implementación de sistemas de detección de fraude en la administración de TC, tanto para el banco como para el usuario, tomó un lugar de privilegio, en pos de minimizar sus pérdidas. Muchas técnicas modernas basadas en inteligencia artificial, minería de datos, lógica difusa, seguridad criptográfica, identificación por datos biométricos, por GPS, por reconocimiento de rostro, por interfaces gestuales, etc., han evolucionado en esta temática, a través de la identificación del usuario, que ha ganado acceso a la sesión de aplicación del usuario titular. Este trabajo presenta las líneas de investigación que se fueron abriendo espacio en la resolución del problema, los modelos computacionales más sobresalientes que avalan estos lineamientos, y las metodologías aplicadas a la fecha que han demostrado, serán las candidatas a resolver el problema del FTC.Facultad de Informátic

Modelos computacionales y metodologías utilizadas en la detección del fraude de las tarjetas de crédito

De la mano de la evolución del comercio electrónico ha devenido el incremento en el uso de las tarjetas de crédito (TC) para realizar compras habituales en internet, y como consecuencia, se ha dado a lugar al incremento del fraude sobre las mismas, llamado fraude online. La implementación de sistemas de detección de fraude en la administración de TC, tanto para el banco como para el usuario, tomó un lugar de privilegio, en pos de minimizar sus pérdidas. Muchas técnicas modernas basadas en inteligencia artificial, minería de datos, lógica difusa, seguridad criptográfica, identificación por datos biométricos, por GPS, por reconocimiento de rostro, por interfaces gestuales, etc., han evolucionado en esta temática, a través de la identificación del usuario, que ha ganado acceso a la sesión de aplicación del usuario titular. Este trabajo presenta las líneas de investigación que se fueron abriendo espacio en la resolución del problema, los modelos computacionales más sobresalientes que avalan estos lineamientos, y las metodologías aplicadas a la fecha que han demostrado, serán las candidatas a resolver el problema del FTC.Facultad de Informátic

Modelos computacionales y metodologías utilizadas en la detección del fraude de las tarjetas de crédito

De la mano de la evolución del comercio electrónico ha devenido el incremento en el uso de las tarjetas de crédito (TC) para realizar compras habituales en internet, y como consecuencia, se ha dado a lugar al incremento del fraude sobre las mismas, llamado fraude online. La implementación de sistemas de detección de fraude en la administración de TC, tanto para el banco como para el usuario, tomó un lugar de privilegio, en pos de minimizar sus pérdidas. Muchas técnicas modernas basadas en inteligencia artificial, minería de datos, lógica difusa, seguridad criptográfica, identificación por datos biométricos, por GPS, por reconocimiento de rostro, por interfaces gestuales, etc., han evolucionado en esta temática, a través de la identificación del usuario, que ha ganado acceso a la sesión de aplicación del usuario titular. Este trabajo presenta las líneas de investigación que se fueron abriendo espacio en la resolución del problema, los modelos computacionales más sobresalientes que avalan estos lineamientos, y las metodologías aplicadas a la fecha que han demostrado, serán las candidatas a resolver el problema del FTC.Facultad de Informátic

Servidores móveis em redes AD HOC

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência da Computação.A arquitetura web services permite que aplicações desenvolvidas em diferentes plataformas interajam com o intuito de trocar dados e realizar tarefas sobre a rede mesmo em ambientes heterogêneos. A arquitetura utiliza uma pilha de padrões entre os quais destacam-se três: WSDL, linguagem utilizada para descrever o serviço, SOAP, protocolo que encapsula as mensagens XML trocadas pela rede e UDDI, mecanismo que age como um repositório de web services, todos com base na linguagem XML. As redes Ad hoc possuem como principal característica uma formação rápida e temporária. Por não necessitar de infra-estrutura fixa, essas redes são estabelecidas rapidamente em locais onde as redes fixas teriam dificuldade ou até mesmo a impossibilidade de serem instaladas. Nessas redes, os nodos comunicam-se diretamente sem a necessidade de infra-estrutura fixa, sendo eles próprios responsáveis pelo roteamento dos pacotes. Este trabalho de pesquisa apresenta um modelo que visa possibilitar a execução de web services em redes Ad hoc. Tendo em vista a usual carência de serviços que os usuários dessas redes possuem, nossa contribuição permite a tais usuários dispor do acesso a alguns serviços, que geralmente estão disponíveis apenas na rede fixa, restringindo o acesso aos serviços móveis à área de cobertura alcançada por essas redes. Nos últimos anos, os dispositivos móveis a capacidade de processamento e armazenamento aumentaram significantemente, o que torna possível, atualmente, a execução de um conjunto relativamente grande de serviços. Por esta razão, assumimos como objetivo principal deste trabalho possibilitar a qualquer dispositivo móvel, conectado a uma rede Ad hoc, o oferecimento de serviços a quaisquer outros dispositivos na mesma rede, tornando-o um servidor móvel. O funcionamento do modelo tem como principal característica o fato de disponibilizar serviços sem que o usuário dependa do auxílio de qualquer infra-estrutura fixa no momento da execução desses serviços. Uma vez concluída essa etapa, o usuário móvel tem autonomia suficiente para coordenar sua função de fornecer os serviços em momentos e locais apropriados. Nossos resultados experimentais indicam que o modelo possui claras vantagens ao ser utilizado em redes Ad hoc. Dentre elas, destacamos o fato de explorar as características desses ambientes com a execução do serviço de modo Ad hoc, levando de fato, serviços a qualquer lugar

Digital transformation: an analysis of opportunities for retailers

In this study, the opportunities and challenges for retailers in the course of the digital transformation were examined from three perspectives: the retailer perspective, the customer perspective, and the platform perspective. The first chapter provides a historical overview of the development of retail, followed by a definition of key terms and a characterisation of the study's subject. Furthermore, the first chapter also derives the guiding research questions for the subsequent chapters. Chapter two presents a survey of 243 LOORO owners from 26 cities in Germany, aimed at understanding why the LOOROs are hesitant about their digital transformation. For the analysis, the study applied a structural equation modelling approach and used the Stimulus-Organism-Response model as a theoretical framework. In the third chapter, the perspective shifts from the retailer to the customer. For this purpose, 1,139 customers were surveyed in four studies on various technologies (e.g. mobile payment, live stream shopping) and their willingness to use or continue using them. The two studies on mobile payment, in particular, expand the existing research to include comparative analyses with existing payment alternatives. From a theoretical perspective, the Technology Threat Avoidance Theory is also used to shift the theoretical perspective from almost exclusively negative feedback loops to positive ones. The third study in Chapter 3, Self-Service Technology, is the first to examine trust in self-service technologies and the different perceptions based on the level of experience. The fourth study in Chapter 3 on live-stream shopping is the first study in Europe on this new service and provides the first theoretical and practical implications for existing research from a European or German perspective. All studies in Chapter 3 were analysed using a structural equation model and other statistical methods for group comparisons (e.g. age, gender, experience). In the fourth chapter, there is another change of perspective. In this case, platforms are analysed as intermediaries or service hubs between the connected retailers and customers. The focus here is particularly on so-called local shopping platforms. These were examined by means of content analysis and telephone interviews. Regarding the content analysis, 149 websites were analysed. In addition, 26 local shopping platform operators were interviewed during the outbreak of the coronavirus pandemic to understand the impact of this pandemic on the platforms. The final study in the fourth chapter compares the results of German LSPs with Chinese LSPs. The results were analysed using Hofstede's cultural dimensions. This study also extends the existing findings in the area of the platform economy with regard to the influence of culture on the service offering. The empirical results were used to derive strategic recommendations for retailers in Chapter 5

Flexible autonomy and context in human-agent collectives

Human-agent collectives (HACs) are collaborative relationships between humans and software agents that are formed to meet the individual and collective goals of their members. In general, different members of a HAC should have differing degrees of autonomy in determining how a goal is to be achieved, and the degree of autonomy that should be enjoyed by each member of the collective varies with context. This thesis explores how norms can be used to achieve context sensitive flexible autonomy in HACs. Norms can be viewed as defining standards of ideal behaviour. In the form of rules and codes, they are widely used to coordinate and regulate activity in human organisations, and more recently they have also been proposed as a coordination mechanism for multi-agent systems (MAS). Norms therefore have the potential to form a common framework for coordination and control in HACs. The thesis develops a novel framework in which group and individual norms are used to specify both the goal to be achieved by a HAC and the degree of autonomy of the HAC and/or of its members in achieving a goal. The framework allows members of a collective to create norms specifying how a goal should (or should not) be achieved, together with sanctions for non-compliance. These norms form part of the decision making context of both the humans and agents in the collective. A prototype implementation of the framework was evaluated using the Colored Trails test-bed in a scenario involving mixed human-agent teams. The experiments confirmed that norms can be used for coordination of HACs and to facilitate context related flexible autonomy