Browsing by Issue Date, starting with "2016-10-11"
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- Software testing environmentPublication . Sirbu, Denis; Daniel, HelderIn this thesis it is proposed a distributed software testing environment, that is able to test a wide variety of applications, such as a user space processes, kernel space processes, web applications and others. The testing environment is supported by an API of probes, where each probe has a specific test task according to its purpose. The base API can be extended to fulfil new testing requirements. This environment can be applied to general software testing, programming contests and as a support for programming classes as the Mooshak automatic judging environment. The essential differences between both these environments is where the software testing is performed. Unlike Mooshak, the proposed test environment can use client computers to do the actual test. This reduces the overhead on the server dramatically, which is especially useful when there are many test submissions simultaneously. These are the cases of classroom environments, lab environments or programming contests. Another option is to have a set of testing computers, or slaves, ready to test user code. However this way more hardware is required. The only requirements for a computer to be a slave, part of the testing environment, is that is has installed a java client application that communicates with the master computer also addressed here as the main server. On the main server a portal allows users to access this testing environment. This master computer is also responsible to distribute the testing workload, according to the choosen strategy, sending to each slave the executable and testing probes, which includes the matching pairs of inputs and expected outputs. After the slaves had performed the tests, they generate a report with information on the tests, and send it back to the master, being available to the users on the portal. To support simultaneous clients the portal is thread based, being launched a new thread to serve each new client connection. Communication between all computers in the test environment, is done using the BSD sockets API.
- A qualidade de serviço prestada ao cliente na ótica das operações - estudo de caso sobre um operador de telecomunicaçõesPublication . Castanho, Cristina do Carmo Martins; Ferreira, Eugénia Maria Dores Maia; Cardoso, Fernando Manuel FélixSaber o que o cliente deseja, espera, gosta, pretende é essencial para a sobrevivência e o sucesso das empresas. Cada dia mais a estratégia das empresas tem como foco o cliente e a sua satisfação, a fim de superar as expectativas dos clientes e desta forma prolongar os seus contratos tornando-os cliente leais. Todavia, esta tarefa não é fácil nem imediata: exige um esforço conjunto de toda a organização. Assim, estudar e ter um profundo conhecimento sobre os clientes revela-se indispensável. Quanto melhor caracterizados estiverem os clientes, mais fácil também será satisfazer as suas necessidades, superar as suas expectativas e criar valor, gerando assim uma relação de confiança e proximidade mútua. A presente dissertação tem como estudo de caso os operadores de telecomunicações e a sua relação com os clientes na ótica das operações. Este estudo pretende caracterizar o cliente com enfoque nas operações, de forma a melhorar a satisfação do mesmo. Com recurso a técnicas de estatística multivariadas, caracterizou-se os clientes, encontrando a melhor interação entre as variáveis que os caracterizam, com as variáveis sobre como os clientes caracterizam o serviço de assistência e manutenção técnica dos operadores. Com base nessa caracterização criou-se um modelo de gestão de avarias, baseado nas variáveis que mais diferenciam e segmentam os clientes. Deste modo, esta investigação permitiu criar um modelo que poderá ser uma mais-valia para a satisfação do cliente e para o melhor desempenho por parte dos operadores, funcionando também como uma ferramenta que poderá levar os operadores a atingirem uma vantagem competitiva num mercado, como o das telecomunicações, que é extremamente agressivo e competitivo.
- Interaction between isothiocyanates and cytochromes P450: a computational docking studyPublication . Nunes, André Filipe da Conceição Marçal Alves; Martel, PauloCancer is the second leading cause of death worldwide. Environmental and lifestyle factors play a crucial role in its development. Certain components of the diet, namely Isothiocyanates (ITCs), which are present in cruciferous vegetables, can act as cancer chemoprevention agents, which may reduce cancer development risk up to 50%. ITCs are thought to act through inhibition of Phase I biotransformation enzymes, cytochromes P450 (CYPs), which are responsible for the bioactivation of many pre-carcinogenic compounds in the body. In this study we used computational (in silico) docking methods to investigate the interaction between ITCs and several important members of the CYP family who are known to be inhibited by this group of chemopreventive agents. Experimental inhibition constants (Ki) were compared with the estimates produce with the in silico docking algorithms. In silico docking was performed using several ITCs (BITC, PEITC, PHITC, PPITC) as ligands and all the CYP files available in the PDB website for the following receptor molecules: CYP2A6, 2A13, 2B6, and 2C9. In order to investigate how different docking algorithms and scoring functions would affect the docking results, the softwares Autodock Vina (Vina) and AutoDock4 (AD4) were both used and compared to other results found in the literature. The relative performance of AD4 and Vina was assessed by in silico redocking the crystallographic ligands of the studied CYPs and comparing the results with the experimentally observed conformations The best docked ligand structure found by both programs is, for most cases, very similar in position and conformation to the crystallographic structure, with Vina producing Ki values in closest agreement with experimental data. In terms of both rigid and flexible docking, Vina produced better results with more accurate Ki values when compared with AD4. Vina is better at flexible while AD4 is better at rigid docking. The docking of a ligand to its crystallographic partner as compared with docking to a different structure of the same CYP generally yields the second best Ki values. ITCs were found to be good inhibitors of CYP2A6 and PHITC is a very good inhibitor of CYP2A13. High Ki values corresponding to weak inhibition were observed for CYP2B6, whereas very poor inhibition was observed for CYP2C9.