Papers by Jesus Martins Oliveira Junior
KRC-CE: High performance distributed shared memory clusters for gLite-based Grids
ABSTRACT
Lecture Notes in Computer Science, 2007
In this paper we describe the execution model supported by suma/g, a middleware built on top of G... more In this paper we describe the execution model supported by suma/g, a middleware built on top of Globus for execution of Java applications on the grid. This execution model allows a user to launch Java applications that will run on a grid from her machine without requiring this machine to be part of the grid (e.g. a gLite User Interface). Additionally, it allows grid users to regard local file systems, i.e. file systems accessible from their local workstations, as part of the set of file systems accessible within the grid. This eliminates the necessity of performing previous uploads of classes and data files, which helps to meet the grid goal of achieving seamless access to distributed resources. We describe how to implement the services offered by this execution model on Globus-based grids. We compare the use of this execution model with the standard mechanisms for submission of Java jobs in lcg/gLite, a flavor of Globus Toolkit 2. We present experiments showing that this execution model can improve performance for running Java applications on Globus-based grids.
Lecture Notes in Computer Science, 2006
This paper describes JaDiMa (Java Distributed Machine), a collaborative framework to construct hi... more This paper describes JaDiMa (Java Distributed Machine), a collaborative framework to construct high performance distributed Java applications on grid platforms. JaDiMa is a system that automatically manages remote libraries used in a Java application. It leverages on the advantages of portability, modularity, object oriented model and flexibility of Java, while incorporating well known techniques of communication and security. JaDiMa allows users to compile and execute Java applications which use distributed libraries, without the need of keeping them in the developer and user hosts. The result is a simple and efficient distributed environment upon which applications and data are easily shared and highly portable amongst heterogeneous platforms and multiple users. We describe an implementation of JaDiMa as part of suma/g, a Globus-based grid environment. We also show experiences of executing an application, which uses libraries for managing graph and network data, on several scenarios with suma/g and JaDiMa.
CLEI Electronic Journal, 2006
This paper describes JADIMA (Java Distributed Machine), a collabora- tive platform to construct h... more This paper describes JADIMA (Java Distributed Machine), a collabora- tive platform to construct high performance distributed JAVA applications. JADIMA is a system that automatically manages the remote libraries used in a JAVA application. JADIMA takes the advantages of portability, modular- ity, flexibility and object oriented model of JAVA, while incorporating well known techniques of communication and security. The result is a simple and efficient distributed environment upon which applications and data are eas- ily shared and highly portable amongst heterogeneous platforms and multi- ple users. JADIMA allows compilation and execution of JAVA applications which use distributed libraries, without the need of keeping them either in the developer or the user hosts. To illustrate the functionality and characteristics of JADIMA, we show examples of constructing real applications with several levels of library package dependencies in distributed environments.
Efficient Distributed Shared Memory on a Single System Image Operating System
In this paper we describe KRC, a kernel-level implementation of DSM paradigm using the Release Co... more In this paper we describe KRC, a kernel-level implementation of DSM paradigm using the Release Consistency (RC) Memory Model on the Kerrighed Single System Image operating system. KRC offers a write-update coherence policy and a Multiple Reader/Multiple Writer (MR/MW) data access algorithm. The main contribution of this work is an adaptive update mechanism which efficiently implements the write-update protocol and the MR/MW data access policy. It consists on the local replication of shared pages (twin copies) and encoding dynamically the changes made on the original versions, hence, only the differences (diffs) are sent to processes sharing data instead of the full modified pages. We present an experimental evaluation of KRC compared with Kerrighed in terms of total execution time, which shows that the execution of parallel applications on KRC, in particular those with false sharing, has a significant performance improvement over the original Kerrighed platform. We also show that KR...
Lecture Notes in Computer Science, 2006
In this paper we introduce and evaluate two prefetching techniques to improve the performance of ... more In this paper we introduce and evaluate two prefetching techniques to improve the performance of Java applications executed on the grid. These techniques are experimentally evaluated on two grid environments, by running test applications on two different grid deployment configurations. Our testbed is suma/g, a grid platform specifically targeted at executing Java bytecode on Globus grids. The experimental results show that these techniques can be effective on improving the performance of applications run on the grid, especially for compute intensive scientific applications.
Trends and Innovations
In distributed environments (e.g. grid platform) it is common to find pieces of reusable code dis... more In distributed environments (e.g. grid platform) it is common to find pieces of reusable code distributed among multiple sites. The possibilities of compilation and execution with remote libraries have a great potential to facilitate the integration of pieces of software developed among different organizations. This chapter describes JaDiMa (Java Distributed Machine), a collaborative framework to construct Java applications on grid platforms. JaDiMa automatically manages library repositories to allow users to compile and execute applications which use distributed libraries, without keeping these libraries locally. JaDiMa services are implemented as Web Services following the SOA approach; library repositories are modeled as a JXTA P2P network; and semantic annotations of libraries assist developers on the tasks of discovering libraries. We describe an implementation of JaDiMa as part of SUMA/G, a Globus-based grid environment. We show experiences and an empirical evaluation of JaDiMa execution and compilation processes for an application which uses remote libraries for managing graph and network data.
Dynamic and Secure Data Access Extensions of Grid Boundaries
Lecture Notes in Computer Science, 2009
Abstract. Grid technology provides a suitable platform for resource sharing, offering users the p... more Abstract. Grid technology provides a suitable platform for resource sharing, offering users the possibility of accessing large-scale controlled environments across different organizational boundaries through a virtu-alized single environment. In order to control accesses to those ...
Foguete de garrafa PET como atividade complementar as aulas de física
Anais Do Salao Internacional De Ensino Pesquisa E Extensao, 2012
Foguete de garrafa PET como atividade complementar as aulas de fisicaGuilherme Brasil, Sheila Cor... more Foguete de garrafa PET como atividade complementar as aulas de fisicaGuilherme Brasil, Sheila Correa, Camila Collares, Jesus de Oliveira, Michely Prestes, Edson M. Kakuno O presente trabalho trata-se de uma experiencia do PIBID Fisica na Escola Estadual de Ensino Medio Dr. Carlos A. Kluwe, onde cinco bolsistas atuam. Este projeto, que foi implementado em 2011 com uma turma de 1a serie da mesma escola, foi considerado tanto pelos alunos do ensino medio quanto pelos bolsistas de iniciacao a docencia (ID) e professores do PIBID como uma atividade ludica que trouxe bons resultados na aprendizagem dos alunos, dessa forma o projeto foi retomado no ano letivo de 2012. No dia 26/09/2012, nas dependencias da Universidade Federal do Pampa (UNIPAMPA), no campus Bage, foi realizado o lancamento de foguetes pelos alunos das turmas: 1101, 1102 e 1110 da escola, com participacao de aproximadamente 65 alunos, os quais tem as aulas de Fisica ministradas pela professora supervisora do PIBID. A atividade foi planejada para ser implementada no 2o semestre de 2012, de forma aprimorada em relacao ao ano anterior. Os bolsistas ID juntamente com a professora, planejaram a atividade definindo objetivos, para que os alunos relacionassem com o conteudo aprendido, sendo eles: (i) compreensao da variacao da velocidade nas componentes horizontal e vertical; (ii) identificacao da influencia da gravidade na velocidade na componente vertical; (iii) relacao do alcance horizontal com os ângulos de lancamento. Os alunos foram divididos em 13 grupos, cada grupo teve que pesquisar e produzir um foguete de garrafa pet, com adornos necessarios para caracterizar um prototipo e uma base regulavel para fazer tres lancamentos, um para cada ângulo (30°, 45° e 60°). Com isso, os alunos alcancaram o objetivo (iii). Uma das evidencias, relatadas por grande parte dos alunos, que prejudicou o lancamento do foguete, foi o fato de no momento da atividade estar ventando no local, principalmente os grupos que nao ficaram entre os predios, enquanto os grupos que ficaram entre os predios foram menos prejudicados por este fato, outros tambem relataram sobre a pouca massa dos foguetes e com isso sofreram mais influencia da resistencia do ar. A atividade proporcionou aos alunos a comparacao de aspectos teoricos e praticos, como por exemplo, o tempo de subida e descida do projetil, que na teoria sao iguais e na pratica isso nao acontece, visto que os modelos teoricos trabalhados em aulas nao levam em consideracao fatores como: o vento, a quantidade de agua colocada no interior do foguete, a pressao adequada. Todos os lancamentos foram filmados para que os bolsistas pudessem fazer a Video analise, com a analise feita pode-se ter os valores da altura maxima, velocidade nos eixos vertical e horizontal, tempo de subida e de descida atraves de um grafico, posteriormente os alunos poderao analisar e discutir seus graficos fazendo a comparacao entre os dados teoricos com os experimentais. Com estas analises os estudantes poderao ter uma melhor visualizacao do que foi feito e isso despertara interesse nos estudantes fazendo que o aprendizado tenha maior significado.
Overcoming Hard Rock Drilling Challenges
Proceedings of IADC/SPE Drilling Conference, 2000
Drilling through hard rock has been a limiting factor to economically develop significant hydroca... more Drilling through hard rock has been a limiting factor to economically develop significant hydrocarbon reserves in several areas. The high cost to explore and develop an oil/gas accumulation is the key factor to be overcome. This paper describes a Joint Industry Project (JIP) that has been started to select and field test the most promising technologies under development that will allow a significant reduction on well cost. Problems faced while drilling hard rocks are not only restricted to slow penetration rate, but also the non-productive time associated to drill string failure, wellbores out of gauge, stuck pipe associated to block instability that falls into the well, and fluid losses due to fractures. Introduction Drilling through hard rocks is most often very costly due to low penetration rates and several related aspects such as, wellbore instabilities, drill string failures, excessive trips required, among others. A JIP was created to select several technologies with potential to improve hard rock drilling performance and the associated problems. The main goal of this JIP is to provide the industry with technological solutions that ultimately can reduce the well costs. The focus when drilling through hard rocks has been to increase the rate of penetration. However, experience has showed that by eliminating the non-productive time associated with high vibration levels, for example, can contribute significantly in turning the development of an oil field in such environments a profitable endeavor. Not only technologies to improve the rate of penetration, but also ways of reducing the vibration levels have been mapped in this project, and will be field tested. The paper initially describes the JIP, the steps and main goals of the project. Then, it presents the most promising technologies selected to be field tested: fluid hammer, jet-assisted drilling, vibration reducers, and a new bit design. The field tests have been planned taking into consideration the risk associated to each technology, as well as the risk involved in the well itself. Minimization of the risk is considered the key issue to successfully field test any technology still under development. Finally, the paper presents the most important results obtained so far. Available Technologies Several technologies1 can be used to improve hard rock drilling performance and solve associated problems. This paper briefly presents them. However, not all of them can be considered ready for field use yet. a) Percussion Hammer Percussion means impact, collision or vibratory shock. Since the early 1900s tools with this concept has been used. In the 1960s happened a increase in the use of these tools, but as long as the drilling industry were not convinced about its effectiveness, utilization decreased during the 1970s. Nowadays, due to the increasing difficulties in some applications, like hard rock or horizontal drilling, the oil industry is reconsidering its use. The poor performance of conventional hammers in mud system with high proportion of solids and abrasives has led to the development of some hydraulic hammer drilling systems. In some instances, wellbore instability and water influx require a hydraulic hammer. In these two cases air hammer is not technically feasible. b) Thrusters The thrusters are hydraulic shock absorbers used to minimize downhole vibrations, reducing bit and drill string failures, improving wellbore stability and increasing the rate of penetration.
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Papers by Jesus Martins Oliveira Junior