WebFlow - A Visual Programming Paradigm for Web/Java Based Coarse Grain Distributed Computing

We present here the recent work at NPAC aimed at developing WebFlow---a general purpose Web based visual interactive programming environment for coarse grain distributed computing. We follow the 3-tier architecture with the central control and integration WebVM layer in tier-2, interacting with the visual graph editor applets in tier-1 (front-end) and the legacy systems in tier-3. WebVM is given by a mesh of Java Web servers such as Jeeves from JavaSoft or Jigsaw from MIT/W3C. All system control structures are implemented as URL-addressable servlets which enable Web browser-based authoring, monitoring, publication, documentation and software distribution tools for distributed computing. We view WebFlow/WEbVM as a promising programming paradigm and coordination model for the exploding volume of Web/Java software, and we illustrate it in a set of ongoing application development activities

JWORB - Java Web Object Request Broker for Commodity Software based Visual Data ow Metacomputing Programming Environment

Programming environments and tools that are simultaneously sustainable, highly functional, robust and easy to use have been hard to come by in the HPDC area. This is partially due to the difficulty in developing sophisticated customized systems for what is relatively small part of the worldwide computing enterprise. As the commodity software becomes naturally distributed with the onset of Web and Intranets, we observe now a new trend in HPDC community [1, 8, 12] to base high performance computing on the modern enterprise computing technologies. .. JWORB is a multi-protocol Java server under development at NPAC, currently capable of handling HTTP and IIOP protocols. Hence, JWORB can be viewed as a Java-based Web Server which can also act as a BORBA broker. We present here JWORB rationale, architecture implementation status, results of early performance measurements and we illustrate its role in the new WebFlow system under development

Java for parallel computing and as a general language for scientific and engineering simulation and modeling

We discuss the role of Java and Web technologies for general simulation. We classify the classes of concurrency typical in problems and analyze separately the role of Java in user interfaces, coarse grain software integration, and detailed computational kernels. We conclude that Java could become a major language for computational science, as it potentially offers good performance, excellent user interfaces, and the advantages of object-oriented structure

Building Distributed Systems for the Pragmatic Object Web

We review the growing power and capability of commodity computing and communication technologies largely driven by commercial distributed information systems. These systems are built from CORBA, Microsoft\u27s COM, JavaBeans, and rapidly advancing Web approaches. One can abstract these to a three-tier model with largely independent clients connected to a distributed network of servers. The latter host various services including object and relational databases and of course parallel and sequential computing. High performance can be obtained by combining concurrency at the middle server tier with optimized parallel back end services. The resultant system combines the needed performance for large-scale HPCC applications with the rich functionality of commodity systems. Further the architecture with distinct interface, server and specialized service implementation layers, naturally allows advances in each area to be easily incorporated. We illustrate how performance can be obtained within a commodity architecture and we propose a middleware integration approach based on JWORB (Java Web Object Broker) multi-protocol server technology. We illustrate our approach on a set of prototype applications in areas such as collaborative systems, support of multidisciplinary interactions, WebFlow based visual metacomputing, WebFlow over Globus, Quantum Monte Carlo and distributed interactive simulations

WebFlow - A Visual Programming Paradigm for Web/Java Based Coarse Grain Distributed Computing

We present here the recent work at NPAC aimed at developing WebFlow---a general purpose Web based visual interactive programming environment for coarse grain distributed computing. We follow the 3-tier architecture with the central control and integration WebVM layer in tier-2, interacting with the visual graph editor applets in tier-1 (front-end) and the legacy systems in tier-3. WebVM is given by a mesh of Java Web servers such as Jeeves from JavaSoft or Jigsaw from MIT/W3C. All system control structures are implemented as URL-addressable servlets which enable Web browser-based authoring, monitoring, publication, documentation and software distribution tools for distributed computing. We view WebFlow/WEbVM as a promising programming paradigm and coordination model for the exploding volume of Web/Java software, and we illustrate it in a set of ongoing application development activities. 1 Introduction As anticipated in our WebWindows ansatz [WebHPCC96], current Web systems, fueled by..

安全で高性能なボランティアコンピューティング基盤に関する研究

Tohoku University小林 広明課

Analysis Of Aircraft Arrival Delay And Airport On-time Performance

While existing grid environments cater to specific needs of a particular user community, we need to go beyond them and consider general-purpose large-scale distributed systems consisting of large collections of heterogeneous computers and communication systems shared by a large user population with very diverse requirements. Coordination, matchmaking, and resource allocation are among the essential functions of large-scale distributed systems. Although deterministic approaches for coordination, matchmaking, and resource allocation have been well studied, they are not suitable for large-scale distributed systems due to the large-scale, the autonomy, and the dynamics of the systems. We have to seek for nondeterministic solutions for large-scale distributed systems. In this dissertation we describe our work on a coordination service, a matchmaking service, and a macro-economic resource allocation model for large-scale distributed systems. The coordination service coordinates the execution of complex tasks in a dynamic environment, the matchmaking service supports finding the appropriate resources for users, and the macro-economic resource allocation model allows a broker to mediate resource providers who want to maximize their revenues and resource consumers who want to get the best resources at the lowest possible price, with some global objectives, e.g., to maximize the resource utilization of the system

Agente de coligação com definição gráfica de processos habilitados por executor de regras: execução e composição dinâmica de skills num sistema de manufactura multiagente

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia Electrotécnica e de ComputadoresA globalização dos mercados e o nível de exigência imposto pelos clientes, em termos de qualidade de produtos e personalização, estão a mudar a forma como a manufactura tem de ser encarada. Como resultado surge, por parte das empresas, a necessidade de implementar processos produtivos mais ágeis, versáteis, robustos e com performance superior. Os requisitos referidos são normalmente obtidos através do uso de componentes autónomos, inteligentes e distribuídos. Uma das aproximações mais promissora ao desenvolvimento deste tipo de sistemas surge sob a forma de multiagentes. Uma das limitações nos sistemas multi-agentes mais utilizados hoje em dia é o facto de as entidades coordenadores não serem genéricas nem intuitivas. A definição da sequência de actividades para o grupo de agentes constituintes dessa coligação implica a necessidade de combinar conhecimentos de domínio e de programação. Sistemas de fluxogramas e regras não possuem estes requisitos pois separam a lógica do código. Porém, em ambas as tecnologias não existe suporte à noção de comunicação, interacção, autonomia e proactividade características inerentes aos agentes. O Objectivo de criar um agente gestor onde o operador comum possa proceder à definição, modificação e execução de processos de forma simples foi o factor que levou à elaboração desta tese. Um agente de coligação com mecanismo de modelação e execução de tarefas complexas foi implementado. O agente de coligação contém um sistema de regras, destinado à dedução de tarefas complexas e um sistema de fluxogramas, requerido para a definição do processo que permite atingir a tarefa computada. Como prova de conceito foi desenvolvido um “Agente Coligador”. Posteriormente o mesmo foi testado numa célula de manufactura laboratorial onde cada entidade se encontra “agentificada” e as suas capacidades se encontram disponíveis para ser descobertas e executadas

Diversity signal sets: implications for organizations and individuals

Organizations send multiple signals to communicate their support for diversity. Questions of how organizations communicate diversity and how such communication relates to organizational and individual outcomes have been of emerging interest to scholars and practitioners. Research on diversity signaling tends to focus on isolated expression-based signals, (i.e., statements made about diversity); however, less is known about evidence-based signals (i.e., diversity performance facts and statistics). I set out to examine different forms of expression-based signals and evidence-based signals and how such diversity signals are related to corresponding organizational performance outcomes and individual job-seeker outcomes of racial/ethnic minority group members. I argue that when organizations communicate diversity signal sets incorporating both expression-based and evidence-based signals positive organizational and individual outcomes will result. Drawing on Spence's (1971) signaling theory, I conduct three studies following the exploratory sequential mixed methods design. I find that organizations communicate multiple diversity signal sets, and such communication has positive implications for organizations and racioethnic minorities. I contribute to organizational research on diversity signaling by introducing the concept of diversity signal sets and by identifying the affective mechanisms behind the influence of multiple diversity signal sets on racioethnic minorities job-related outcomes. Study One shows that US Fortune 500 firms signal four types of expression-based signals: equal opportunity (EO), business case (BC), value-and-integration (VI) and mixed, and three types of evidence-based signals: third-party bestowed diversity awards or recognition, employee demographics; and leadership demographics. These findings inform the selection of variables in the subsequent studies – Studies Two and Three. Study Two examines the association between different types of expression-based signals and their association with evidence-based signals and organizational outcomes. Findings demonstrate that companies with no diversity signals on their corporate websites have negative financial (ROA and ROIC) and diversity-related performance (measured by external recognition/awards of diversity). I find the relationship between companies communicating VI type of expression-based signals and their diversity-related performance significantly positive. Study Three explores organizational diversity signal sets and their influence on racioethnic minorities' job-related outcomes. I determine that diversity signal sets comprising of both expression-based and evidence-based signals significantly influence racioethnic minorities’ organizational attraction and leadership aspirations through different affective mechanisms (i.e., perceptions of inclusion and perceptions of affective trust). My research contributes to signaling theory by introducing diversity signal sets and by testing their organizational and individual implications. It opens future research avenues for investigation of diversity signal sets in global companies and their organizational and individual implications for multiple diversity groups in the workplace