180 research outputs found

    Design and Implementation of an Intranet Security and Access Control System in Ubi-Com

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    Currently, most enterprise intranet systems process user information for security and access authentication purposes. However, this information is often captured by unauthorized users who may edit, modify, delete or otherwise corrupt this data. In addition, corruption can result from inaccurate communication protocols in the web browser. Therefore, a method is needed to prevent unauthorized or erroneous access and modification of data through the intranet. This paper proposes an efficient security procedure that incorporates a new model that allows flexible web security access control in securing information over the intranet in UC. The proposed web security access control system improves the intranet data and access security by using encryption and decryption techniques. It further improves the security access control by providing authentication corresponding to different security page levels relevant to public ownership and information sensitivity between different enterprise departments. This approach reduces processing time and prevents information leakage and corruption caused by mistakes that occur as a result of communication protocol errors between client PC's or mail security methods

    Exploring key antecedents through a technology acceptance perspective

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    The main aim of this Ph.D. thesis in Management is to provide better understanding of the role of Information Systems (ISs) in the decision-making process and successful performance of Higher Education Institutions (HEIs), exploring the antecedents of technology acceptance. To achieve the objectives defined, four articles were elaborated: a Systematic Literature Review (SLR) and three articles of an empirical nature. Therefore, the first article aimed to identify, explore and systematize the main topics regarding the role of web portals as tools to support information management in HEIs. Based on 126 articles published up to 5 November 2016 on the Web of Science and SCOPUS databases, four major topics were identified, namely, the software used in web portals, internal and external benefits of using web portals, technology acceptance and information storage and management. The main contribution of this research lies in identifying the main topics and trends in scientific production for each topic identified, and in identifying gaps and future lines of research in this field of study. The second article aimed to study the influence of web portals in supporting HEI management and performance, considering personality traits, perceived usefulness and perceived ease of use, through an empirical study. To achieve the aim proposed, Structural Equation Modelling (SEM) was used together with a structured questionnaire administered to teaching and non-teaching staff in Portuguese HEIs. The results obtained, through 338 valid responses, indicate a positive influence of personality traits on the use of web portals and that their use also has a positive influence on HEIs’ performance. The third chapter sought to identify the factors influencing the use of e-learning platforms in the Portuguese academic context through an empirical study. A structured questionnaire was used to collect information. Based on 631 valid responses, SEM was applied, leading to the conclusion that, in accordance with Innovation Diffusion Theory (IDT), the characteristics of e-learning platforms and Personal Innovativeness in Information Technology (PIIT) have a positive influence on the use of this tool. The fourth and final article aimed to identify and explain the factors of successful operation, implementation and use of e-libraries in the academic context of Portuguese higher education. To achieve this goal, a qualitative approach was adopted, through a case study of the e-library at the University of Beira Interior (UBI). Primary data were obtained from interviews with staff of the library, computer services and administration of this teaching institution holding leadership positions and directly involved in the implementation, maintenance or use of the e-library. The empirical evidence highlights the importance of minimizing costs, particularly by forming cooperation protocols, the use of open-source software and training of UBI library staff. Acceptance and use of the e-library depends on the platform’s characteristics, the ease of access to information, actions to publicise and make the whole academic community aware of the e-library and its functions, and implementation of appealing, intuitive User Interfaces (UIs). In addition, the training of students and library staff was revealed as a relevant factor for acceptance of this tool. For the future, the creation of a functional search aggregator is suggested, to allow a simultaneous search in all the databases and creating the least noise possible. This function could be implemented based on multi-disciplinary teams with skills acquired through specific training. This study was based on Resource-Based View (RBV) and Social Learning Theory (SLT). In this thesis, considering the four studies developed, it was possible to support the influence of IS acceptance on HEIs’ performance and determine the role of ISs in supporting these institutions’ management, in the Portuguese academic context. This research also presents contributions to theory and implications for practice, as well as future lines of study on the topic.O principal objetivo desta tese de doutoramento em Gestão consistiu em proporcionar uma melhor compreensão acerca do papel dos Sistemas de Informação (SIs) no processo de tomada de decisão e no sucesso da performance das Higher Education Institutions (HEIs), explorando os antecedentes da aceitação das tecnologias. Para conseguir alcançar os propósitos definidos, foram elaborados quatro artigos: uma Systematic Literature Review (SLR) e três artigos de natureza empírica. Neste sentido, o primeiro artigo teve por objetivo a identificação, exploração e sistematização dos principais temas sobre o papel dos portais web como ferramentas para apoiar a gestão da informação nas HEI. Tendo por base 126 artigos publicados até ao dia 5 de novembro de 2016, nas bases de dados Web of Science e SCOPUS foi possível identificar quatro grandes temáticas, nomeadamente, software utilizado em Portais Web, benefícios internos e externos da utilização de Portais Web, aceitação das tecnologias e o armazenamento e gestão da informação. O principal contributo desta investigação prende-se com a identificação das principais temáticas e tendências da produção científica em cada temática identificada, bem como, a identificação de lacunas e futuras linhas de investigação dentro deste campo de investigação. O segundo artigo teve por objetivo estudar a influência dos portais web no apoio à gestão e no desempenho das HEIs, tendo em consideração os traços de personalidade, a perceção acerca da utilidade e da facilidade de utilização, através de um estudo empírico. Para conseguir alcançar o objetivo proposto, recorreu-se ao Strucutral Equation Modeling (SEM) e a um questionário estruturado, dirigido a pessoal docente e não docente de HEIs portuguesas. Os resultados obtidos, através de 338 respostas válidas, indicam que existe uma influência positiva entre os traços de personalidade e a utilização dos portais web e que a sua utilização também influencia positivamente o desempenho das HEIs. No terceiro artigo procurou-se identificar os fatores que influenciam a utilização de plataformas de e-learning no contexto académico português, através de um estudo empírico. Recorreu-se a um questionário estruturado como objeto de recolha de informação. Tendo por base 631 respostas válidas, aplicou-se o SEM e podemos concluir que, em concordância com a Teoria da Difusão da inovação (TDI), as caraterísticas das plataformas de e-learning e o Personal Innovativeness in Information Technology (PIIT) influenciam de forma positiva a utilização desta ferramenta. O quarto e último artigo teve por objetivo a identificação e explicação de fatores para o bom funcionamento, implementação e utilização de e-librarys no contexto académico do ensino superior português. Para alcançar o objetivo proposto adotou-se uma abordagem qualitativa, através de um estudo de caso da e-library da Universidade da Beira Interior (UBI). Os dados primários obtiveram-se com recurso a entrevistas ao Staff da Biblioteca, dos Serviços de informática e da Administração desta instituição de ensino, com posições de chefia e envolvidos de forma direta na implementação, manutenção ou utilização da e-library. As evidências empíricas ressaltam a importância para a minimização de custos, nomeadamente, a celebração de protocolos de cooperação, a utilização de software open source e a formação do staff da biblioteca da UBI. A aceitação e utilização da e-library, depende das caraterísticas da plataforma, da facilidade do acesso à informação, de ações de divulgação que deem a conhecer a toda a academia a e-library e as suas funcionalidades e da implementação de User Interfaces (UIs) apelativas e intuitivas. Adicionalmente, a formação de alunos e do staff da biblioteca revelou ser um fator relevante para a aceitação desta ferramenta. De futuro sugere-se a criação de um agregador de pesquisa funcional, que pesquise em simultâneo em todas as bases de dados e crie o menor ruido possível. Esta funcionalidade será possível ser implementada com base em equipas multidisciplinares com as skills adquiridas através de formação especifica. Este estudo teve por base a Resource-Based View (RBV) e a Social Learning Theory (SLT). Neste trabalho de tese, tendo em consideração os quatro estudos desenvolvidos, foi possível sustentar a influência da aceitação de SIs no desempenho das HEIs e averiguar o papel dos SIs no apoio dado à gestão destas instituições, no contexto académico português. Esta investigação apresenta também contributos para a teoria e implicações para a prática, bem como, futuras linhas de investigação acerca da temática em estudo

    The IPTS Report No. 57, September 2001

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    Towards a Tool-based Development Methodology for Pervasive Computing Applications

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    Despite much progress, developing a pervasive computing application remains a challenge because of a lack of conceptual frameworks and supporting tools. This challenge involves coping with heterogeneous devices, overcoming the intricacies of distributed systems technologies, working out an architecture for the application, encoding it in a program, writing specific code to test the application, and finally deploying it. This paper presents a design language and a tool suite covering the development life-cycle of a pervasive computing application. The design language allows to define a taxonomy of area-specific building-blocks, abstracting over their heterogeneity. This language also includes a layer to define the architecture of an application, following an architectural pattern commonly used in the pervasive computing domain. Our underlying methodology assigns roles to the stakeholders, providing separation of concerns. Our tool suite includes a compiler that takes design artifacts written in our language as input and generates a programming framework that supports the subsequent development stages, namely implementation, testing, and deployment. Our methodology has been applied on a wide spectrum of areas. Based on these experiments, we assess our approach through three criteria: expressiveness, usability, and productivity

    The IPTS Report No. 57, September 2001

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    Reliable online social network data collection

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    Large quantities of information are shared through online social networks, making them attractive sources of data for social network research. When studying the usage of online social networks, these data may not describe properly users’ behaviours. For instance, the data collected often include content shared by the users only, or content accessible to the researchers, hence obfuscating a large amount of data that would help understanding users’ behaviours and privacy concerns. Moreover, the data collection methods employed in experiments may also have an effect on data reliability when participants self-report inacurrate information or are observed while using a simulated application. Understanding the effects of these collection methods on data reliability is paramount for the study of social networks; for understanding user behaviour; for designing socially-aware applications and services; and for mining data collected from such social networks and applications. This chapter reviews previous research which has looked at social network data collection and user behaviour in these networks. We highlight shortcomings in the methods used in these studies, and introduce our own methodology and user study based on the Experience Sampling Method; we claim our methodology leads to the collection of more reliable data by capturing both those data which are shared and not shared. We conclude with suggestions for collecting and mining data from online social networks.Postprin

    Cassava and its harvesting | La yuca y su cosecha

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    Cassava (Manihot esculenta Crant) is one of the most important economic crops in tropical and subtropical areas. The average yield, compared to its potential, is often low. Harvesting is done with several procedures in global areas; the operation is difficult, costly and of low productivity in most regions. The primary objectives of  this study were: to assess the techniques of cassava harvest under different methods, land preparation and planting, damage or break of tubers, manual and mechanized harvesting, adaptation of varieties, the effect of agronomic parameters, soil moisture during harvest, new hand tools and mechanical harvesting. The evaluation methods consisted of literature reviewing, explorations, examination of existing tools, modifications and mathematical analysis with design and calculation. As a result, an assessment is made of manual and mechanized techniques for harvesting, and recommendations are provided about mechanical properties, devices for tuber collection, genetics, seed and importance of soil moisture during harvest. Key words: Soil moisture, tillage, varieties, planting, harvesting hand tools, mechanized harvesters.  RESUMEN La yuca (Manihot esculenta Crant) es uno de los cultivos económicos más importantes en las zonas tropicales y subtropicales. El rendimiento promedio, comparado con su potencial, suele ser bajo. La cosecha se realiza con varios procedimientos en áreas globales conocidas; la operación es difícil, costosa y de baja productividad en la mayoría de las regiones. Los objetivos principales de este estudio fueron: evaluar las técnicas de cosecha de yuca bajo diferentes métodos, la plantación, el daño o rotura de los tubérculos, la cosecha manual y mecanizada, la adaptación de las variedades, el efecto de los parámetros agronómicos, la humedad del suelo durante la cosecha, nuevas herramientas manuales y la recolección mecánica. Los métodos consistieron en revisión de la literatura, examen de las herramientas existentes, modificaciones y análisis matemático con diseño y cálculo. Como resultado, se hace una evaluación de la técnica manual y mecanizada para la cosecha, y se formulan recomendaciones de características mecánicas, dispositivos de recolección, genética, semilla e importancia de la humedad del suelo durante la cosecha. Palabras clave: Humedad del suelo, labranza, variedades, siembra, herramientas manuales para la cosecha, cosecha mecanizada
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