Agents for invocation of web services

Web services are becoming popular and widely accepted on the Internet. UDDI is the standard for publishing and discovery of web services. In this paper, we investigate semantics description of web services based on domain ontology; based on this language, we propose an architecture for invoking agents to consume services within the UDDI registry. The semantics service description language together with agent creation
architecture provides a new way to discover and utilise published web services. This method is flexible and extendable to accomplish complex web service requests.

Service migration in autonomic service oriented grids

The introduction of Web services into grids helped to address their two main obstacles to be embraced by business and industry, heterogeneity and useability. However, many problems are still open, e.g., grid reconfiguration, reliability and computing optimization. We argue here that a mechanism that could help solving these problems is Web Service migration, a part of automatic and transparent brokerage. Web service migration presents a number of new requirements not addressed in traditional process migration, being the outcome of Web services specific configuration of hosts and application servers, and availability of Web services / resources state. In this paper we report on our study into the development of a Web service migration facility focused on providing migration of services in a Service Oriented Grid environment. We present a novel approach to Web service migration, embodied in a System Management Broker, which is transparent, interoperable and flexible. We take the requirements of Web services into consideration when discovering suitable destination hosts and match services to suitable grid resources which are able to fulfil the needs of the service. We discuss a number of experiments conducted with different types of grid and Web service applications to highlight the feasibility and effectiveness of our migration facility and demonstrate how our facility significantly improves Service Oriented Grids.

Defending grid web services from XDoS attacks by SOTA

Grid Web Services are still relevantly a new to business systems, and as more systems are being attached to it, any threat to it could bring collapse and huge harm. Some of these potential threats to Grid Web services come in a new form of a new denial of service attack (DoS), called XML Denial of Service or XDOS attacks. Though, as yet, there have not been any reported attacks from the media, we have observed these attacks are actually far less complex to implement than any previous Denial of Service (DoS), but still just as affective. Current security applications for grid web services (WS-Security for example), based on our observations, and are not up to job of handling the problem. In this paper, we build on our previous work called Service Oriented Traceback Architecture (SOTA), and apply our model to Grid Networks that employ web services. We further introduce a filter defence system, called XDetector, to work in combination with SOTA. Our results show that SOTA in conjunction with XDetector makes for an effective defence against XDoS attacks and upcoming DXDoS.

Delivering categorized news items using RSS feeds and web services

In the past decade the massive growth of the Internet brought huge changes in the way humans live their daily life; however, the biggest concern with rapid growth of digital information is how to efficiently manage and filter unwanted data. In this paper, we propose a method for managing RSS feeds from various news websites. A Web service was developed to provide filtered news items extracted from RSS feeds and these were categorized based on classical text categorization algorithms. A client application consuming this Web service retrieves and displays such filtered information. A prototype was implemented using Rapidminer 4.3 as a data mining tool and SVM as a classification algorithm. Experimental results suggest that the proposed method is effective and saves a significant amount of user processing time.

Gestão de alarmes para a web e dispositivos móveis, utilizando o software Connexall

A adoção de software de gestão de alarmes revela-se essencial nas organizações, sobretudo no contexto hospitalar e de segurança, devido à celeridade com que os alarmes têm de ser processados nos ambientes críticos em que são gerados. Nos últimos anos, tem-se verificado uma enorme promoção de diretivas que recomendam a utilização de software de gestão de alarmes, de forma a que as organizações estejam preparadas para lidar com situações problemáticas e para prestar um serviço de qualidade. O fenómeno da ubiquidade computacional promovido pela utilização massiva da Web e de dispositivos móveis revolucionou de forma significativa o modo como as pessoas comunicam e partilham informação entre si. Deste modo, tem havido uma consciencialização por parte das organizações que desenvolvem sistemas de gestão de alarmes em investir recursos na migração das suas aplicações de desktop para a Web e para dispositivos móveis. O Connexall é uma das soluções de gestão de alarmes com maior adoção no mercado, no entanto, carece de aplicações de software focalizadas na Web e nos dispositivos móveis. Neste sentido, o objetivo deste projeto de mestrado consiste em desenvolver duas aplicações de gestão de alarmes, o Active Alarm Client Plus para Android e o Device Assignment Client para a Web, integradas com o Connexall, através da utilização de um Web service para o efeito. Com o desenvolvimento deste projeto, pretende-se expandir os horizontes de aplicação do Connexall no que diz respeito à diversidade de equipamentos computacionais presentes no mercado, de modo a promover a ubiquidade cada vez mais assente no acesso e partilha de informação no contexto de gestão de alarmes.

Especificação e implementação de um protótipo de serviço web para buscas baseadas em contextos compartilhados definidos a partir de sintagmas e relacionamentos

The popularization of the Internet has stimulated the appearance of Search Engines that have as their objective aid the users in the Web information research process. However, it s common for users to make queries and receive results which do not satisfy their initial needs. The Information Retrieval in Context (IRiX) technique allows for the information related to a specific theme to be related to the initial user query, enabling, in this way, better results. This study presents a prototype of a search engine based on contexts built from linguistic gatherings and on relationships defined by the user. The context information can be shared with softwares and other tool users with the objective of promoting a socialization of contexts

Um ambiente para especificação e execução AD-HOC de processos de negócio baseados em serviços Web

Recently the focus given to Web Services and Semantic Web technologies has provided the development of several research projects in different ways to addressing the Web services composition issue. Meanwhile, the challenge of creating an environment that provides the specification of an abstract business process and that it is automatically implemented by a composite service in a dynamic way is considered a currently open problem. WSDL and BPEL provided by industry support only manual service composition because they lack needed semantics so that Web services are discovered, selected and combined by software agents. Services ontology provided by Semantic Web enriches the syntactic descriptions of Web services to facilitate the automation of tasks, such as discovery and composition. This work presents an environment for specifying and ad-hoc executing Web services-based business processes, named WebFlowAH. The WebFlowAH employs common domain ontology to describe both Web services and business processes. It allows processes specification in terms of users goals or desires that are expressed based on the concepts of such common domain ontology. This approach allows processes to be specified in an abstract high level way, unburdening the user from the underline details needed to effectively run the process workflow

PEWS-RT, um sistema de tempo de execução para a linguagem PEWS

Web services are loosely coupled applications that use XML documents as a way of integrating distinct systems on the internet. Such documents are used by in standards such as SOAP, WSDL and UDDI which establish, respectively, integrated patterns for the representation of messages, description, and publication of services, thus facilitating the interoperability between heterogeneous systems. Often one single service does not meet the users needs, therefore new systems can be designed from the composition of two or more services. This which is the design goal behind the of the Service Oriented Architecture. Parallel to this scenario, we have the PEWS (Predicate Path-Expressions for Web Services) language, which speci es behavioural speci cations of composite web service interfaces.. The development of the PEWS language is divided into two parts: front-end and back-end. From a PEWS program, the front-end performs the lexical analysis, syntactic and semantic compositions and nally generate XML code. The function of the back-end is to execute the composition PEWS. This master's dissertation work aims to: (i) reformulate the proposed architecture for the runtime system of the language, (ii) Implement the back-end for PEWS by using .NET Framework tools to execute PEWS programs using the Windows Work ow Foundation

Web Services Aplicados à Visualização

With the rapid growth of the use of Web applications in various fields of knowledge, the term Web service enter into evidence in the current scenario, which refers to services from different origins and purpose, offered through local networks and also available in some cases, on the Internet. The architecture of this type of application offers data processing on server side thereby, running applications and complex and slow processes is very interesting, which is the case with most algorithms involving visualization. The VTK is a library intended for visualization, and features a large variety of methods and algorithms for this purpose, but with a graphics engine that requires processing capacity. The union of these two resources can bring interesting results and contribute for performance improvements in the VTK library. This study is discussed in this project, through testing and communication overhead analysis

ITScan: a web-based analysis tool for Internal Transcribed Spacer (ITS) sequences

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

DiffServer: Application Level Differentiated Services for Web Servers

Web content hosting, in which a Web server stores and provides Web access to documents for different customers, is becoming increasingly common. For example, a web server can host webpages for several different companies and individuals. Traditionally, Web Service Providers (WSPs) provide all customers with the same level of performance (best-effort service). Most service differentiation has been in the pricing structure (individual vs. business rates) or the connectivity type (dial-up access vs. leased line, etc.). This report presents DiffServer, a program that implements two simple, server-side, application-level mechanisms (server-centric and client-centric) to provide different levels of web service. The results of the experiments show that there is not much overhead due to the addition of this additional layer of abstraction between the client and the Apache web server under light load conditions. Also, the average waiting time for high priority requests decreases significantly after they are assigned priorities as compared to a FIFO approach.

MWRegEx : monitor web de expresiones regulares

[ES] El Trabajo de Fin de Grado, Monitor Web de Expresiones Regulares (MWRegEx), es una herramienta basada en tecnologías web, desarrollada usando el entorno Visual Studio. El objetivo principal de la aplicación es dar apoyo a la docencia de expresiones regulares, en el marco de la enseñanza del manejo de ristras de caracteres en las asignaturas de programación del Grado en Ingeniería Informática.  La aplicación permite obtener el dibujo de un autómata de una expresión regular, facilitando su comprensión; además, permite aplicar la expresión a diferentes ristras de caracteres, mostrando las coincidencias encontradas, y ofrece una versión de la expresión adaptada a su uso en literales string de lenguajes como Java y otros. La herramienta se ha implementado en dos partes: un servicio web, escrito en C#, donde se realizan todos los análisis de las expresiones regulares y las ristras a contrastar; y un cliente web, implementado usando tecnología asp.net, con JavaScript y JQuery, que gestiona la interfaz de usuario y muestra los resultados. Esta separación permite que el servicio web pueda ser reutilizado con otras aplicaciones cliente. El autómata que representa una expresión regular esta dibujado usando la librería Raphaël JavaScript que permite manejar los elementos SVG. Cada elemento de la expresión regular tiene un dibujo diferente y único para así diferenciarlo. Toda la interfaz gráfica de usuario está internacionalizada de manera tal que pueda adaptarse a diferentes idiomas y regiones sin la necesidad de realizar cambios de ingeniería ni en el código. Tanto el servicio web como la parte cliente están estructurados para que se puedan agregar nuevas modificaciones sin que esto genere una onda expansiva a lo largo de las diversas clases existentes.

Data and behavioral contracts for web services

The recent trend in Web services is fostering a computing scenario where loosely coupled parties interact in a distributed and dynamic environment. Such interactions are sequences of xml messages and in order to assemble parties – either statically or dynamically – it is important to verify that the “contracts” of the parties are “compatible”. The Web Service Description Language (wsdl) is a standard used for describing one-way (asynchronous) and request/response (synchronous) interactions. Web Service Conversation Language extends wscl contracts by allowing the description of arbitrary, possibly cyclic sequences of exchanged messages between communicating parties. Unfortunately, neither wsdl nor wscl can effectively define a notion of compatibility, for the very simple reason that they do not provide any formal characterization of their contract languages. We define two contract languages for Web services. The first one is a data contract language and allow us to describe a Web service in terms of messages (xml documents) that can be sent or received. The second one is a behavioral contract language and allow us to give an abstract definition of the Web service conversation protocol. Both these languages are equipped with a sort of “sub-typing” relation and, therefore, they are suitable to be used for querying Web services repositories. In particular a query for a service compatible with a given contract may safely return services with “greater” contract.