4 resultados para Web services. Service Composition. PEWS. Runtime systems
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo
Resumo:
The web services (WS) technology provides a comprehensive solution for representing, discovering, and invoking services in a wide variety of environments, including Service Oriented Architectures (SOA) and grid computing systems. At the core of WS technology lie a number of XML-based standards, such as the Simple Object Access Protocol (SOAP), that have successfully ensured WS extensibility, transparency, and interoperability. Nonetheless, there is an increasing demand to enhance WS performance, which is severely impaired by XML's verbosity. SOAP communications produce considerable network traffic, making them unfit for distributed, loosely coupled, and heterogeneous computing environments such as the open Internet. Also, they introduce higher latency and processing delays than other technologies, like Java RMI and CORBA. WS research has recently focused on SOAP performance enhancement. Many approaches build on the observation that SOAP message exchange usually involves highly similar messages (those created by the same implementation usually have the same structure, and those sent from a server to multiple clients tend to show similarities in structure and content). Similarity evaluation and differential encoding have thus emerged as SOAP performance enhancement techniques. The main idea is to identify the common parts of SOAP messages, to be processed only once, avoiding a large amount of overhead. Other approaches investigate nontraditional processor architectures, including micro-and macrolevel parallel processing solutions, so as to further increase the processing rates of SOAP/XML software toolkits. This survey paper provides a concise, yet comprehensive review of the research efforts aimed at SOAP performance enhancement. A unified view of the problem is provided, covering almost every phase of SOAP processing, ranging over message parsing, serialization, deserialization, compression, multicasting, security evaluation, and data/instruction-level processing.
Resumo:
The behavior of composed Web services depends on the results of the invoked services; unexpected behavior of one of the invoked services can threat the correct execution of an entire composition. This paper proposes an event-based approach to black-box testing of Web service compositions based on event sequence graphs, which are extended by facilities to deal not only with service behavior under regular circumstances (i.e., where cooperating services are working as expected) but also with their behavior in undesirable situations (i.e., where cooperating services are not working as expected). Furthermore, the approach can be used independently of artifacts (e.g., Business Process Execution Language) or type of composition (orchestration/choreography). A large case study, based on a commercial Web application, demonstrates the feasibility of the approach and analyzes its characteristics. Test generation and execution are supported by dedicated tools. Especially, the use of an enterprise service bus for test execution is noteworthy and differs from other approaches. The results of the case study encourage to suggest that the new approach has the power to detect faults systematically, performing properly even with complex and large compositions. Copyright © 2012 John Wiley & Sons, Ltd.
Resumo:
The service sector has acquired a growing importance in every country economy, which has stimulated research in the field of service innovation, a new field in management studies. This text aimed to state a research agenda upon service innovation, based on an articulated discussion of the results of several articles that compose the state of the art of this concept. 73 empirical articles were analyzed, 33% of them exploring the innovation strategies and technology; 18% of the articles describe research on economic performance and enterprise productivity; 16% are related to antecedents and determinants of innovation; another 16% about network capacity development, alliances and collaboration among organizations; 9% of the articles explore service quality, innovation taxonomy, flexible systems and regional systems of innovation; and another 8% are related to themes such as intensive knowledge, research and development. The researches were concentrated in the Engineering & Technology and Hospitality Industries, which accounted for 31% and 24% of the texts, respectively. The remaining 45% of the articles referred to sectors such as Telecommunications, Health, Retail, Financial & Insurance and Public Services. The main gaps identified in these texts refer to the difficulties on measuring service innovation, besides the small number of researches on the public sector. At the end, a research agenda in the subject is presented, including the development of a scale for orientating the innovation and identifying the determining factors of the innovation in the public environment.
Resumo:
This descriptive and quantitative study aimed to characterize the production of nursing care in primary health care services in a region of the city of Ribeirao Preto, state of Sao Paulo, Brazil. The study sample comprised care actions delivered by nurses and registered in the HygiaWeb Information System, from 2006 to 2009. Statistical analysis was performed. Results showed that nursing care delivered by nurses accounted for 9.5 to 14.6% of total professional care provided by professionals. Eventual care actions were the most frequent. The concentration of programmatic care was higher for children, women, pregnant and postpartum women. In conclusion, the predominance of eventual care demonstrated that the health system has been focused on acute conditions. Little of nursing work has been directed at the achievement of comprehensiveness, considering the inexpressive share of longitudinal follow up in total care delivery. The expansion of nursing staff represents potential for care delivery to the population, but further qualification of nursing actions is needed.