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Comparison of three decontamination methods for Mycobacterium bovis isolation; Comparação de três métodos de descontaminação para isolamento de Mycobacterium bovis

AMBROSIO, Simone Rodrigues; OLIVEIRA, Eugenia Márcia de Deus; RODRIGUEZ, Cesar Alejandro Rosales; FERREIRA NETO, José Soares; AMAKU, Marcos
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
27.51%
Sixty samples of tissue fragments with lesions suggestive of tuberculosis from bovine abattoirs, kept in saturated solution of sodium borate, were subjected to four treatments: 4% NaOH (Petroff Method), 12 % H2SO4 and 1.5% HPC (1-Hexadecylpyridinium Chloride) decontamination, and physiological saline solution (control). The HPC method showed the lowest contamination rate (3%) when compared to control (88%, p<0.001), NaOH (33%, p<0.001) and H2SO4 (21.7%, p<0.002). Regarding the isolation success, the HPC method was better (40%) than the control (3%, p<0.001), NaOH (13%, p=0.001) and H2SO4 (1.7%, p<0.001) methods. These results indicate that HPC is an alternative to the Petroff method.; Sessenta amostras de fragmentos de tecidos com lesões sugestivas de tuberculose provenientes de abatedouros bovinos, conservadas em solução saturada de borato de sódio, foram submetidas a quatro tratamentos: descontaminação através dos métodos NaOH 4% (Método Petroff), H2SO4 12% e HPC (Cloreto de hexadecilpiridínio) 1,5%, e solução salina (controle). O método HPC apresentou a menor proporção de contaminação (3%), em relação ao controle (88%, p<0,001), NaOH (33%, p<0,001) e H2SO4 (21,7%, p=0,002). Em relação ao sucesso no isolamento...

Métodos bacteriológicos aplicados à tuberculose bovina: comparação de três métodos de descontaminação e de três protocolos para criopreservação de isolados ; Bacteriologic methods applied to bovine tuberculosis: comparison of three decontamination methods and three protocols for cryopreservation of isolates

Ambrosio, Simone Rodrigues
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 09/12/2005 PT
Relevância na Pesquisa
27.37%
Dada a importância do Programa Nacional de Controle e Erradicação da Brucelose e Tuberculose (PNCEBT), a necessidade de uma eficiente caracterização bacteriológica dos focos como ponto fundamental do sistema de vigilância e as dificuldades encontradas pelos laboratórios quanto aos métodos de isolamento de Mycobacterium bovis fizeram crescer o interesse do meio científico por estudos, sobretudo moleculares, de isolados M. bovis. Para a realização dessas técnicas moleculares, é necessária abundância de massa bacilar, obtida através da manutenção dos isolados em laboratório e repiques em meios de cultura. Entretanto o crescimento fastidioso do M. bovis em meios de cultura traz grandes dificuldades para essas operações. Assim sendo, o presente estudo teve por objetivos: 1º) Comparar três métodos de descontaminação para homogeneizados de órgãos, etapa que precede a semeadura em meios de cultura, onde 60 amostras de tecidos com lesões granulomatosas, provenientes de abatedouros bovinos do Estado de São Paulo, foram colhidas e imersas em solução saturada de Borato de Sódio e transportadas para o Laboratório de Zoonoses Bacterianas do VPS-FMVZ-USP, onde foram processadas até 60 dias após a colheita. Essas amostras foram submetidas a três métodos de descontaminação: Básico (NaOH 4%)...

Preparação e caracterização de eletrólitos sólidos poliméricos a partir dos derivados de celulose - hidroxietilcelulose e hidroxipropilcelulose; Preparation and characterization of solid polymeric electrolytes based on hydroxypropylcellulose and hydroxyethlcellulose

Machado, Gilmara de Oliveira
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 19/04/2004 PT
Relevância na Pesquisa
27.47%
Esta tese apresenta os resultados da obtenção de eletrólitos sólidos poliméricos a partir dos derivados de celulose - hidroxipropilcelulose (HPC) e hidroxietilcelulose (HEC), ambas comerciais. Para atingir os objetivos do projeto, os dois derivados passaram por diferentes processos sendo que a HEC foi modificada fisicamente por meio de plastificação com glicerol e HPC foi alterada quimicamente. A transformação química consistiu nas reações de oxidação de grupos hidroxila da HPC em grupos cetona que, em seguida, foram submetidos as reações de enxertia com diamina de poli(óxido de propileno) [Jeffamina] resultando em redes por meio de ligações imina. A adição do sal perclorato de lítio, em diferentes concentrações, na matriz plastificada ou entrecruzada, resultou na obtenção de eletrólitos sólidos poliméricos, todos na forma de filmes. A caracterização destes eletrólitos foi realizada com técnicas básicas de caracterização de materiais como: análises térmicas (DSC, TGA), análise térmica dinâmico-mecânica (DMTA), análises estruturais (raios-X), medidas espectroscópicas (IR, UVNIS), análise elementar, microscopia eletrônica de varredura (SEM), e, como a mais importante, medidas de condutividade iônica utilizando a técnica de espectroscopia de impedância eletroquímica (EIS).; The present thesis reports the preparation and characterization of new types of solid polymeric electrolytes (SPE) based on cellulose derivatives such as hydroxypropylcellulose (HPC) and hydroxyethylcellulose (HEC)...

Are geopolymers more suitable than Portland cement to produce high volume recycled aggregates HPC?

Torgal, Fernando Pacheco; Ding, Yining; Miraldo, Sérgio; Abdollahnejad, Zahra; Labrincha, J. A.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em 02/08/2012 ENG
Relevância na Pesquisa
37.19%
The 70% minimum construction and demolition wastes-C&DW recycling rate set by the Revised Waste framework Directive No. 2008/98/EC to be enforced beyond 2020, will increase the need of effective recycling methods in a dramatic manner. So far, recycled aggregates (which constitute the majority of C&DW) are reused in low volume percentages for average compressive strength concretes and mostly as road sub-base and back-fill material which, in turn, constitutes a down-cycling option. Most investigations related to concrete made with recycled aggregates use aggregates produced in laboratory context which are not contaminated at all. It is then no surprise to find out that some investigations shows the potential to reuse as much as 100%, however, industrially produced recycled aggregates contain a certain level of impurities that can be deleterious for Portland cement concrete, thus making very difficult for the concrete industry to use such investigations unless uncontaminated recycled aggregates are used. This paper reviews current knowledge on concrete made with recycled aggregates, with a special focus on the crucial importance of impurities presence and how those aggregates are not suitable for the production of HPC. Also, the potential of geopolymers to produce HPC based on high volume recycled aggregates is discussed.

Targeting HPC with the help of nanoparticles : an overview

Torgal, Fernando Pacheco; Miraldo, Sérgio; Ding, Yning; Labrincha, J. A.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2013 ENG
Relevância na Pesquisa
37.29%
According to the 2011 ERMCO statistics only a mere 11% of the ready-mixed concrete class production relates to the HPC target, furthermore, this percentage remains unchanged at least since the year 2001. This represents a strange option from the construction industry since HPC offers several advantages over normal-strength concrete, namely, high strength and high durability. Therefore, HPC allows for concrete structures with less steel reinforcement and a longer service life, both of which are crucial issues in the eco-efficiency of construction materials. Although nanotechnology is a very hot issue the fact is that investigations on the field of concrete with nanoparticles are rare (100 in 10,000 Scopus concrete related articles published in the last decade). Actually, it remains to be seen how this research area will contribute to concrete eco-efficiency. This paper summarizes current knowledge on the field of concrete containing nanoparticles. It includes the influence of nanoparticles on the mechanical properties of concrete and on its durability. It also includes calcium leaching control. Moreover, the problem of efficient dispersion of nanoparticles is analyzed.

Nanoparticles for high performance concrete (HPC)

Torgal, Fernando Pacheco; Miraldo, Sérgio; Ding, Yining; Labrincha, J. A.
Fonte: WoodHead Publishing Ltd Publicador: WoodHead Publishing Ltd
Tipo: Parte de Livro
Publicado em //2013 ENG
Relevância na Pesquisa
37.19%
According to the 2011 ERMCO statistics, only 11% of the production of ready-mixed concrete relates to the high performance concrete (HPC) target. This percentage has remained unchanged since at least 2001 and appears a strange choice on the part of the construction industry, as HPC offers several advantages over normal-strength concrete, specifically those of high strength and durability. It allows for concrete structures requiring less steel reinforcement and offers a longer serviceable life, both of which are crucial issues in the eco-efficiency of construction materials. Despite the growing importance of nanotechnology, investigations into the incorporation of nanoparticles into concrete are rare (100 out of 10,000 Scopus concrete-related articles published in the last decade). It therefore remains to be seen how research in this area will contribute to concrete eco-efficiency. This chapter summarizes the state of current knowledge in the field and considers the influence of nanoparticles on the mechanical properties of concrete and its durability. It also includes the control of calcium leaching. The problem of efficient dispersion of nanoparticles is analyzed.

The suitability of concrete using recycled aggregates (RAs) for high-performance concrete (HPC)

Torgal, Fernando Pacheco; Ding, Y.; Miraldo, Sérgio; Abdollahnejad, Zahra; Labrincha, J. A.
Fonte: WoodHead Publishing Ltd Publicador: WoodHead Publishing Ltd
Tipo: Parte de Livro
Publicado em //2013 ENG
Relevância na Pesquisa
37.29%
Most studies related to concrete made with recycled aggregates (RA) use uncontaminated aggregates produced in the laboratory, revealing the potential to re-use as much as 100%. However, industrially produced RA contain a certain level of impurities that can be deleterious for Portland cement concrete, thus making it difficult for the concrete industry to use such investigations unless uncontaminated RA are used. This chapter reviews current knowledge on concrete made with RA, with a focus on the crucial importance of the presence of impurities, and how those aggregates are not suitable for the production of high-performance concrete (HPC). The potential of geopolymers to produce HPC based on high volume RA is also discussed.

Botulinum neurotoxin C1 blocks neurotransmitter release by means of cleaving HPC-1/syntaxin.

Blasi, J; Chapman, E R; Yamasaki, S; Binz, T; Niemann, H; Jahn, R
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /12/1993 EN
Relevância na Pesquisa
27.47%
The anaerobic bacterium Clostridium botulinum produces several related neurotoxins that block exocytosis of synaptic vesicles in nerve terminals and that are responsible for the clinical manifestations of botulism. Recently, it was reported that botulinum neurotoxin type B as well as tetanus toxin act as zinc-dependent proteases that specifically cleave synaptobrevin, a membrane protein of synaptic vesicles (Link et al., Biochem. Biophys. Res. Commun., 189, 1017-1023; Schiavo et al., Nature, 359, 832-835). Here we report that inhibition of neurotransmitter release by botulinum neurotoxin type C1 was associated with the proteolysis of HPC-1 (= syntaxin), a membrane protein present in axonal and synaptic membranes. Breakdown of HPC-1/syntaxin was selective since no other protein degradation was detectable. In vitro studies showed that the breakdown was due to a direct interaction between HPC-1/syntaxin and the toxin light chain which acts as a metallo-endoprotease. Toxin-induced cleavage resulted in the generation of a soluble fragment of HPC-1/syntaxin that is 2-4 kDa smaller than the native protein. When HPC-1/syntaxin was translated in vitro, cleavage occurred only when translation was performed in the presence of microsomes, although a full-length product was obtained in the absence of membranes. However...

Low-Viscosity Hydroxypropylcellulose (HPC) Grades SL and SSL: Versatile Pharmaceutical Polymers for Dissolution Enhancement, Controlled Release, and Pharmaceutical Processing

Sarode, Ashish; Wang, Peng; Cote, Catherine; Worthen, David R.
Fonte: Springer US Publicador: Springer US
Tipo: Artigo de Revista Científica
Publicado em 19/12/2012 EN
Relevância na Pesquisa
27.54%
Hydroxypropylcellulose (HPC)-SL and -SSL, low-viscosity hydroxypropylcellulose polymers, are versatile pharmaceutical excipients. The utility of HPC polymers was assessed for both dissolution enhancement and sustained release of pharmaceutical drugs using various processing techniques. The BCS class II drugs carbamazepine (CBZ), hydrochlorthiazide, and phenytoin (PHT) were hot melt mixed (HMM) with various polymers. PHT formulations produced by solvent evaporation (SE) and ball milling (BM) were prepared using HPC-SSL. HMM formulations of BCS class I chlorpheniramine maleate (CPM) were prepared using HPC-SL and -SSL. These solid dispersions (SDs) manufactured using different processes were evaluated for amorphous transformation and dissolution characteristics. Drug degradation because of HMM processing was also assessed. Amorphous conversion using HMM could be achieved only for relatively low-melting CBZ and CPM. SE and BM did not produce amorphous SDs of PHT using HPC-SSL. Chemical stability of all the drugs was maintained using HPC during the HMM process. Dissolution enhancement was observed in HPC-based HMMs and compared well to other polymers. The dissolution enhancement of PHT was in the order of SE > BM > HMM > physical mixtures...

Influência do tipo e do tempo de duração de cura nas propriedades mecânicas de concretos de alto desempenho (CAD) produzidos em períodos quente (t>25°C) e de baixa umidade relativa do ar (h<50%); Influence of the type and time duration of curing in mechanical properties of the high performance concrete (hpc) produced in hot period (t>25ºc) and of low relative humidity the air (h<50%).

BESERRA, Simone Ataíde
Fonte: Universidade Federal de Goiás; BR; UFG; Mestrado em Engenharia Civil; Engenharias Publicador: Universidade Federal de Goiás; BR; UFG; Mestrado em Engenharia Civil; Engenharias
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
37.37%
In the case of conventional concrete, small constructive defects, variations of mix proportion or even inadequate curings can not compromise significantly the material. No longer HPC demands a severity in the control since its dosage until the execution, therefore any imperfection can bring serious damages to the material or the structure. Amongst the relative aspects most important to the total quality of any concrete it is the curing, that becomes basic when is about HPC. The curing of the high performance concrete constitutes in a controversial subject in the technician area as well as the type and duration of it, therefore the necessity of a deeper refined study on this subject. This research verifies the influence of the type and time of duration of curing in the mechanical properties of the HPC (compressive strength, flexion tensile strength and module of deformation), produced in Goiânia in hot period (t>25ºC) and of low relative humidity of air (h<50%) situation this considered critical for NBR 14931/2003 and predominant in the months of May the September in this region. In the experimental study were produced HPC of target compressive strength 60, 80 and 100MPa, from the Furnas Mix Proportion Method, using cement CP II-F-32...

Coordinated Checkpoint/Restart Process Fault Tolerance for MPI Applications on HPC Systems

Hursey, Joshua James
Fonte: [Bloomington, Ind.] : Indiana University Publicador: [Bloomington, Ind.] : Indiana University
Tipo: Doctoral Dissertation
EN
Relevância na Pesquisa
27.43%
Thesis (Ph.D.) - Indiana University, Computer Sciences, 2010; Scientists use advanced computing techniques to assist in answering the complex questions at the forefront of discovery. The High Performance Computing (HPC) scientific applications created by these scientists are running longer and scaling to larger systems. These applications must be able to tolerate the inevitable failure of a subset of processes (process failures) that occur as a result of pushing the reliability boundaries of HPC systems. HPC system reliability is emerging as a problem in future exascale systems where the time to failure is measured in minutes or hours instead of days or months. Resilient applications (i.e., applications that can continue to run despite process failures) depend on resilient communication and runtime environments to sustain the application across process failures. Unfortunately, these environments are uncommon and not typically present on HPC systems. In order to preserve performance, scalability, and scientific accuracy, a resilient application may choose the invasiveness of the recovery solution, from completely transparent to completely application-directed. Therefore, resilient communication and runtime environments must provide customizable fault recovery mechanisms. Resilient applications often use rollback recovery techniques for fault tolerance: particularly popular are checkpoint/restart (C/R) techniques. HPC applications commonly use the Message Passing Interface (MPI) standard for communication. This thesis identifies a complete set of capabilities that compose to form a coordinated C/R infrastructure for MPI applications running on HPC systems. These capabilities...

University Finds Windows HPC Server Matches Linux in Validated SPEC Benchmarks

Microsoft Corp.
Fonte: Microsoft Corp. Publicador: Microsoft Corp.
Tipo: Relatório
EN_US
Relevância na Pesquisa
37.47%
Case study: Indiana University (IU) ran the first published, validated high-performance computing (HPC) benchmarks on Windows HPC Server and Linux, and found the two perform about the same across applications and cluster sizes. But Windows HPC Server opens new possibilities when it comes to market options and use beyond the traditional science uses of HPC. IU is planning to implement Windows HPC Server in its overall HPC strategy.

Diseño e implementación de un sistema de almacenamiento masivo "LOW COST" de alto rendimiento y escalabilidad para entornos HPC; Design and implementation of a high performance, scalability and massive storage system "LOW COST" for HPC enviroments

Varela Haya, Alejandro
Fonte: Universidade de Cantabria Publicador: Universidade de Cantabria
Tipo: Trabalho de Conclusão de Curso
SPA
Relevância na Pesquisa
37.54%
RESUMEN: Una de las principales finalidades de este proyecto es aportar una solución al actual sistema de almacenamiento del clúster HPC calderón, el cual se encuentra ubicado en la Facultad de Ciencias (CPD 3 Mares) y esta administrado por el grupo de Arquitectura y Tecnología de Computadores(ATC) del departamento de Electrónica y Computadores de la Universidad de Cantabria. Este clúster de cálculo de alto rendimiento consiste fundamentalmente en un conjunto de unos 100 computadores trabajando de forma coordinada en la resolución de problemas científicos. Para ello, el sistema dispone de mas de 800 procesadores, 1.5 TB de memoria RAM y redes de altas prestaciones myrinet e infiniband. Su sistema de almacenamiento global actualmente en producción consiste en un sistema distribuido usando como tecnología de distribución de ficheros AFS, la cual tiene importantes problemas de escalabilidad en cuanto a rendimiento. Este sistema tiene centralizado en 3 servidores y dos bandejas de discos toda la gestión y el almacenamiento físico (discos hardware). Estos 3 servidores gestionan todo el sistema distribuido. Uno de ellos se encarga de almacenar los metadatos del sistema de ficheros y lo otros dos restantes se encargar de almacenar y gestionar los datos de usuarios y aplicaciones. El sistema de ficheros distribuido AFS...

Plataforma web para la extracción de trazas en sistemas HPC; Web platform for trace extraction in HPC systems

Pérez Gallardo, Iván
Fonte: Universidade de Cantabria Publicador: Universidade de Cantabria
Tipo: Trabalho de Conclusão de Curso
SPA
Relevância na Pesquisa
37.64%
RESUMEN: Los sistemas de High Performance Computing (HPC) ejecutan programas paralelos que aprovechan la capacidad de múltiples nodos de cómputo del sistema. Para ello, los diferentes procesos de cada nodo se comunican entre sí mediante algún tipo de mecanismo de comunicación, típicamente mensajes MPI. La optimización de las aplicaciones para estos sistemas precisa de mecanismos que informen de los eventos que ocurren en el sistema, permitiendo analizar las diferentes fases de ejecución, las comunicaciones entre nodos, impacto en la escalabilidad, etc. La obtención de trazas de la ejecución de las aplicaciones permite visualizar estos parámetros. Además, las trazas de aplicaciones paralelas son muy útiles en la investigación en el entorno de HPC, típicamente empleándose en herramientas de simulación. La extracción de trazas resulta en muchas ocasiones una tarea compleja, por la dificultad de acceso a sistemas de HPC lo suficientemente grandes, por la complejidad de uso de las herramientas de extracción o por lo tedioso del proceso. Por estos motivos, las trazas de aplicaciones se consideran muy valiosas en el entorno académico, y en ocasiones no se comparten, impidiendo la repetibilidad de los experimentos. El objetivo de este proyecto ha sido desarrollar una plataforma web capaz de extraer trazas de programas paralelos MPI en sistemas HPC y compartirlas abiertamente a modo de repositorio. La funcionalidad de la plataforma desarrollada permitirá a los usuarios extraer trazas de sus propios programas MPI así como de programas que hayan sido publicados por otros usuarios...

Design and Evaluation of Low-Latency Communication Middleware on High Performance Computing Systems

Rey Expósito, Roberto
Fonte: Universidade da Corunha Publicador: Universidade da Corunha
Tipo: Tese de Doutorado
ENG
Relevância na Pesquisa
27.6%
[Resumen]El interés en Java para computación paralela está motivado por sus interesantes características, tales como su soporte multithread, portabilidad, facilidad de aprendizaje,alta productividad y el aumento significativo en su rendimiento omputacional. No obstante, las aplicaciones paralelas en Java carecen generalmente de mecanismos de comunicación eficientes, los cuales utilizan a menudo protocolos basados en sockets incapaces de obtener el máximo provecho de las redes de baja latencia, obstaculizando la adopción de Java en computación de altas prestaciones (High Per- formance Computing, HPC). Esta Tesis Doctoral presenta el diseño, implementación y evaluación de soluciones de comunicación en Java que superan esta limitación. En consecuencia, se desarrollaron múltiples dispositivos de comunicación a bajo nivel para paso de mensajes en Java (Message-Passing in Java, MPJ) que aprovechan al máximo el hardware de red subyacente mediante operaciones de acceso directo a memoria remota que proporcionan comunicaciones de baja latencia. También se incluye una biblioteca de paso de mensajes en Java totalmente funcional, FastMPJ, en la cual se integraron los dispositivos de comunicación. La evaluación experimental ha mostrado que las primitivas de comunicación de FastMPJ son competitivas en comparación con bibliotecas nativas...

On Autonomic HPC Clouds

Petcu, Dana
Fonte: Universidade Carlos III de Madrid Publicador: Universidade Carlos III de Madrid
Tipo: info:eu-repo/semantics/publishedVersion; info:eu-repo/semantics/bookPart; info:eu-repo/semantics/conferenceObject
Publicado em /10/2015 ENG
Relevância na Pesquisa
37.54%
The long tail of science using HPC facilities is looking nowadays to instant available HPC Clouds as a viable alternative to the long waiting queues of supercomputing centers. While the name of HPC Cloud is suggesting a Cloud service, the current HPC-as-a-Service is mainly an offer of bar metal, better named cluster-on-demand. The elasticity and virtualization benefits of the Clouds are not exploited by HPC-as-a-Service. In this paper we discuss how the HPC Cloud offer can be improved from a particular point of view, of automation. After a reminder of the characteristics of the Autonomic Cloud, we project the requirements and expectations to what we name Autonomic HPC Clouds. Finally, we point towards the expected results of the latest research and development activities related to the topics that were identified.; The work related to Autonomic HPC Clouds is supported by the European Commission under grant agreement H2020-6643946 (CloudLightning). The CLoudLightning project proposal was prepared by eight partner institutions, three of them as earlier partners in the COST Action IC1305 NESUS, benefiting from its inputs for the proposal. The section related to Autonomic Clouds is supported by the Romanian UEFISCDI under grant agreement PN-II-ID-PCE-2011- 3-0260 (AMICAS).; Proceedings of: Second International Workshop on Sustainable Ultrascale Computing Systems (NESUS 2015). Krakow (Poland)...

New contributions for modeling and simulating high performance computing applications on parallel and distributed architectures

Núñez Covarrubias, Alberto
Fonte: Universidade Carlos III de Madrid Publicador: Universidade Carlos III de Madrid
Tipo: Tese de Doutorado Formato: application/pdf
ENG
Relevância na Pesquisa
27.51%
In this thesis we propose a new simulation platform specifically designed for modeling parallel and distributed architectures, which consists on integrating the model of the four basic systems into a single simulation platform. Those systems consist of storage system, memory system, processing system and network system. The main characteristics of this platform are flexibility, to embrace the widest range of possible designs; scalability, to check the limits of extending the architecture designs; and the necessary trade-offs between the execution time and the accuracy obtained. This simulation platform is aimed to model both existent and new designs of HPC architectures and applications. Then, depending on the user's requirements, the model can be focused on a set of the basic systems, or by the contrary on the complete system. Therefore, a complete distributed system can be modeled by integrating those basic systems in the model, each one with the corresponding level of detail, which provides a high level of flexibility. Moreover, it provides a good compromise between accuracy and performance, and flexibility provided for building a wide range of architectures with different configurations. A validation process of the proposed simulation platform has been fulfilled by comparing the results obtained in real architectures with those obtained in the analogous simulated environments. Furthermore...

Monitoring HPC Clusters

Turner, George W.
Fonte: Universidade de Indiana Publicador: Universidade de Indiana
Tipo: Conferência ou Objeto de Conferência
EN_US
Relevância na Pesquisa
37.37%
The session on monitoring HPC clusters was presented at the 2014 Linux Cluster Institute's Workshop - a hands-on workshop that covered the fundamentals of setting up and administering a high-performance computing (HPC) cluster. Offered by the Linux Clusters Institute (LCI), this workshop was led by some of the world's leading HPC experts and was held Aug. 4-8, 2014 at the National Center for Supercomputing Applications (NCSA) in Urbana, Illinois. LCI is the premier international forum for sharing information on management, administration, and scientific computing techniques for high-performance computing. Topics included intro to HPC, resource performance, availability, utilization, security, Build-A-Cluster, Condo Model, and Remote Visualization.

Analyzing Power Consumption of I/O Operations in HPC Applications

Llopis Sanmillan, Pablo; Dolz Zaragoza, Manuel Francisco; García Blas, Javier; Isaila, Florín Daniel; Carretero Pérez, Jesús; Heidari, Mohammad Reza; Kuhn, Michael
Fonte: Universidade Carlos III de Madrid Publicador: Universidade Carlos III de Madrid
Tipo: info:eu-repo/semantics/publishedVersion; info:eu-repo/semantics/bookPart; info:eu-repo/semantics/conferenceObject
Publicado em /10/2015 ENG
Relevância na Pesquisa
37.03%
Data movement is becoming a key issue in terms of performance and energy consumption in high performance computing (HPC) systems, in general, and Exascale systems, in particular. A preliminary step to perform I/O optimization and face the Exascale challenges is to deepen our understanding of energy consumption across the I/O stacks. In this paper, we analyze the power draw of different I/O operations using a new fine-grained internal wattmeter while simultaneously collecting system metrics. Based on correlations between the recorded metrics and the instantaneous internal power consumption, our methodology identifies the significant metrics with respect to power consumption and decides which ones should contribute directly or in a derivative manner. This approach has the advantage of building I/O power models based on a previous set of identified utilization metrics. This technique will be validated using write operations on an Intel Xeon Nehalem server system, as writes exhibit interesting patterns and distinct power regimes.; The work presented in this paper has been partially supported by the EU Project FP7 318793 “EXA2GREEN” and partially supported by the EU under the COST Programme Action IC1305, “Network for Sustainable Ultrascale Computing (NESUS)” and by the grant TIN2013-41350-P...

NVision-PA: A Tool for Visual Analysis of Command Behavior Based on Process Accounting Logs (with a Case Study in HPC Cluster Security)

Ermopoulos, Charis; Yurcik, William
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 20/06/2006
Relevância na Pesquisa
27.47%
In the UNIX/Linux environment the kernel can log every command process created by every user with process accounting. Thus process accounting logs have many potential uses, particularly the monitoring and forensic investigation of security events. Previous work successfully leveraged the use of process accounting logs to identify a difficult to detect and damaging intrusion against high performance computing (HPC) clusters, masquerade attacks, where intruders masquerade as legitimate users with purloined authentication credentials. While masqueraders on HPC clusters were found to be identifiable with a high accuracy (greater than 90%), this accuracy is still not high enough for HPC production environments where greater than 99% accuracy is needed. This paper incrementally advances the goal of more accurately identifying masqueraders on HPC clusters by seeking to identify features within command sets that distinguish masqueraders. To accomplish this goal, we created NVision-PA, a software tool that produces text and graphic statistical summaries describing input processing accounting logs. We report NVision-PA results describing two different process accounting logs; one from Internet usage and one from HPC cluster usage. These results identify the distinguishing features of Internet users (as proxies for masqueraders) posing as clusters users. This research is both a promising next step toward creating a real-time masquerade detection sensor for production HPC clusters as well as providing another tool for system administrators to use for statistically monitoring and managing legitimate workloads (as indicated by command usage) in HPC environments.; Comment: 25 pages...