Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-10-18T19:35:37Z No. of bitstreams: 1 DemostenesSantosDeSena_TESE.pdf: 4593790 bytes, checksum: 3e0845d816f16e3a8f7659744e28f8ad (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-10-19T19:11:29Z (GMT) No. of bitstreams: 1 DemostenesSantosDeSena_TESE.pdf: 4593790 bytes, checksum: 3e0845d816f16e3a8f7659744e28f8ad (MD5) / Made available in DSpace on 2017-10-19T19:11:30Z (GMT). No. of bitstreams: 1 DemostenesSantosDeSena_TESE.pdf: 4593790 bytes, checksum: 3e0845d816f16e3a8f7659744e28f8ad (MD5) Previous issue date: 2017-02-13 / Os mecanismos de tratamento de exce??es s?o recursos fornecidos pelas principais linguagens de programa??o para auxiliar no desenvolvimento de sistemas robustos. A pol?tica de tratamento de exce??es corresponde ao conjunto de regras de design do tratamento excepcional e definem os elementos de c?digo (m?todos, classes ou pacotes) respons?veis pela sinaliza??o, propaga??o, captura das exce??es e as respectivas a??es de tratamento. Alguns estudos emp?ricos demonstraram que o tratamento inadequado de exce??es, consequ?ncia da falta da pol?tica documentada, ? uma poss?vel fonte de defeitos. Por outro lado, devido ? natureza impl?cita dos fluxos de exce??es, a identifica??o e corre??o dos tratamentos de exce??es tornam-se tarefas complexas. Para amenizar os problemas decorrentes do tratamento inadequado devido ? falta de documenta??o do tratamento de exce??es, algumas abordagens definiram linguagens de especifica??o das regras de tratamento com suporte ferramental para auxiliar na defini??o e checagem das regras. Entretanto, historicamente, as pol?ticas de tratamento de exce??es dos sistemas s?o postergadas ou ignoradas no processo de desenvolvimento. Adicionalmente, nenhuma das abordagens propostas oferece suporte ? defini??o das regras, de forma a auxiliar o arquiteto a extrair as regras a partir da an?lise de c?digo fonte pr?-existente, e este ? o objetivo da abordagem apresentada neste trabalho. Para apoiar a execu??o da abordagem proposta, foi desenvolvida uma ferramenta de an?lise est?tica que permite: (i) a coleta dos fluxos excepcionas e das respectivas a??es de tratamentos; (ii) a identifica??o e defini??o dos agrupamentos, que s?o os elementos de c?digo que possuem os mesmos comportamentos em rela??o ao tratamento de exce??es; (iii) a extra??o das regras; e, (iv) a checagem das regras e identifica??o das causas das viola??es ? pol?tica. A abordagem ? demonstrada em dois estudos emp?ricos. No primeiro estudo emp?rico foram analisadas 656 bibliotecas (libs) Java do reposit?rio central Maven com objetivo de extrair e caracterizar a pol?tica de tratamento de exce??es destas libs. Este estudo revelou que 80,9% das bibliotecas possuem fluxos excepcionais que implementam pelo menos um anti-pattern do tratamento excepcional. O segundo estudo emp?rico teve como objetivo investigar os benef?cios da extra??o das regras excepcionais a partir do c?digo pr?-existente no processo de defini??o e checagem da pol?tica de tratamento de exce??es. Dois sistemas de informa??o Web (i.e., IProject e SIGAA) foram utilizados neste segundo estudo. Neste estudo pudemos observar que todas as regras reportadas pelos arquitetos foram extra?das pelo suporte ferramental, e que os resultados do processo de extra??o permitiram que novas regras fossem adicionadas pelos arquitetos. Essas regras adicionadas foram as regras n?o definidas pelos arquitetos e corresponderam ? 57,1% (IProject) e 52,8% (SIGAA/Gradua??o) das regras da pol?tica dos sistemas analisados. O processo de checagem das regras definidas com o apoio da abordagem mostrou que 35,6% e 45,7% dos fluxos excepcionais do IProject e SIGAA/Gradua??o, respectivamente, violavam alguma das regras de tratamento de exce??es. / The Exception handling (EH) mechanism is a technique embedded in most of the mainstream programming languages to support the development of robust systems. The exception handling policy is composed by the set of exception handling design rules and which specify the elements (methods, classes and packages) or that contains the elements responsible for raising, propagating and catching of exceptions as well as the handling actions. Empirical studies have demonstrated that an inappropriate exception handling as consequence of undocumented exception handling policy is a source of bug hazards. On the other hand, due to the implicit nature of exception flows, the identification of exception handling code is a complex task. To address the problems resulting from the not-understood or inadequate exception handling, some approaches have been proposed languages to specify exception handling rules as well as a set of support tool to verify the constraints and checking the rules. However, historically, the exception handling policies are postponed or ignored in the software process development. Additionally, none of the proposed approaches provide support to the phase of exception policy definition. This work proposes an approach that helps the architect to extract the EH rules by performing an analysis on the existing code. Doing so, this approach fills the previous gap the EH policy definition. To support the proposed approach, a static tool suite was developed, which performs: (i) the discovery of exception flows and its handling actions; (ii) the definition of compartments; (iii) the semi-automatic rule extraction process; and (iv) the rule checking and identification of rule violation causes. This approach was assessed in two empirical studies. In the first study, 656 libraries from Maven central repository were analyzed. The main goal of this study was to reveal and to characterize the exception handling policy of the analyzed libraries. This study revealed that 80.9% of the analyzed libraries have exception flows that implement at least one exception handling anti-pattern. In the second study, we investigated the benefits of rule extraction process in the definition and checking of exception handling rules. Two web information systems (i.e., IProject and SIGAA) were analyzed in this second study. We found that all set of rules reported by the architects were extracted by our tool and the result of extraction process allowed that new rules were added to the policy. These added rules were not defined by architects and they corresponded to 57.1% (IProject) and 52.8% (SIGAA/Gradua??o) of the rules of analyzed systems. The checking process of defined rules supported by our approach verified that 35.6% (IProject) and 45.7% (SIGAA/Gradua??o) of exception flows violated some defined rule.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-06-02T22:25:24Z No. of bitstreams: 1 AndrieleNascimentoDeSouza_DISSERT.pdf: 14510659 bytes, checksum: b589d39cc71e5725449a5974847ba202 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-06-08T21:37:57Z (GMT) No. of bitstreams: 1 AndrieleNascimentoDeSouza_DISSERT.pdf: 14510659 bytes, checksum: b589d39cc71e5725449a5974847ba202 (MD5) / Made available in DSpace on 2017-06-08T21:37:57Z (GMT). No. of bitstreams: 1 AndrieleNascimentoDeSouza_DISSERT.pdf: 14510659 bytes, checksum: b589d39cc71e5725449a5974847ba202 (MD5) Previous issue date: 2017-03-30 / A Barragem Eng. Armando Ribeiro Gon?alves, mais conhecida como Barragem de A?u, ? uma obra geot?cnica de expressiva notoriedade e import?ncia no Rio Grande do Norte e no Nordeste. Al?m do seu porte ? ? a maior barragem do RN ? e import?ncia, ganhou destaque na literatura nacional e internacional pelo rompimento do talude de montante no final do per?odo construtivo. A partir da an?lise dos dados de instrumenta??o dispon?veis no meio acad?mico, o presente trabalho teve como objetivo analisar o comportamento da obra nas etapas de constru??o do maci?o, primeiro enchimento e opera??o do reservat?rio. Em cada etapa, foi analisado: o comportamento tens?o-deforma??o; a varia??o de poro-press?es; e a estabilidade de taludes. As an?lises foram feitas com os softwares Sigma/W, Seep/W e Slope/W, pertencentes ao pacote Geo-Studio, da empresa Geo-Slope. Os resultados das modelagens foram comparados aos dados da instrumenta??o, dispon?veis em Rocha (2003). Na an?lise comparativa dos deslocamentos verticais, a maior diferen?a entre os resultados da modelagem e os dados da instrumenta??o foi de 8,9 cm, no extens?metro T7, no final do primeiro enchimento. Na an?lise da estabilidade, o fator de seguran?a mais baixo foi de 1,3, fornecido pelo m?todo dos elementos finitos, para o talude de montante, na fase de opera??o do reservat?rio. Entretanto, a m?dia dos fatores de seguran?a obtidos pelos m?todos baseados no equil?brio-limite nesta etapa foi de 2,4. Para o talude de jusante, esse fator foi de 1,6 em todas as etapas. Esses resultados comprovam a condi??o est?vel da barragem de A?u. Na an?lise de poropress?es, os piez?metros pneum?ticos apresentaram maiores diverg?ncias, entre modelagem e instrumenta??o, do que os de tubo aberto. A diferen?a mais expressiva foi de 46% (23 kPa), no piez?metro PZP1, no primeiro enchimento do reservat?rio. Entretanto, considerando as diferen?as obtidas por outros autores que tamb?m estudaram o fluxo nesta barragem, conclui-se que os resultados da an?lise s?o satisfat?rios e que os par?metros adotados s?o adequados para caracterizar os solos modelados. / The A?u Dam is an important geotechnical built in Rio Grande do Norte and in Northeast Brazilian, especially because of its size and complexity. In addition to its size and importance, it has gained prominence in the national and international literature because of the collapse in upstream slope in the end of construction period. This paper aimed to analyze its behavior in stages of dam construction, first filling and operation of the reservoir. In each step, were analyzed: the stress-strain behavior, the flow and the pore-pressure variation, and the slope stability. These analyses were performed with the software Sigma/W, Seep/W and Slope/W, which are components in a suite of geotechnical products called GeoStudio, produced by Geo-Slope International Ltd. The results were compared with the instrumentation dates available in Rocha (2003). In the comparative analysis of vertical displacements, the largest difference between modeling results and instrumentation data was 8.9 cm, in the T7 extensometer, at the end of the first filling. In the stability analysis, the lowest safety factor was 1.3 for the upstream slope in the reservoir operation phase, but the media of the safety factors obtained by the methods based on limit equilibrium was 2.4. For a downstream slope, this factor was equal to 1.6 in all stages. These results confirm the dam stable condition. In pore-pressure analysis, the pneumatic piezometers presented greater divergences between modeling and instrumentation than those of the Casagrande type. The most significant difference was 46% (23 kPa), in the PZP1 piezometer, at the first filling of the reservoir. However, considering the differences obtained by other authors who also studied the water flow in this dam, we conclude that the results of the present analysis are satisfactory and that the adopted parameters are adequate to characterize the soils modeled.