Putting meaning into NETMAR – the open service network for marine environmental data

The open service network for marine environmental data (NETMAR) project uses semantic web technologies in its pilot system which aims to allow users to search, download and integrate satellite, in situ and model data from open ocean and coastal areas. The semantic web is an extension of the fundamental ideas of the World Wide Web, building a web of data through annotation of metadata and data with hyperlinked resources. Within the framework of the NETMAR project, an interconnected semantic web resource was developed to aid in data and web service discovery and to validate Open Geospatial Consortium Web Processing Service orchestration. A second semantic resource was developed to support interoperability of coastal web atlases across jurisdictional boundaries. This paper outlines the approach taken to producing the resource registry used within the NETMAR project and demonstrates the use of these semantic resources to support user interactions with systems. Such interconnected semantic resources allow the increased ability to share and disseminate data through the facilitation of interoperability between data providers. The formal representation of geospatial knowledge to advance geospatial interoperability is a growing research area. Tools and methods such as those outlined in this paper have the potential to support these efforts.

Reasoning about orchestrations of web services using partial correctness

A service is a remote computational facility which is made available for general use by means of a wide-area network. Several types of service arise in practice: stateless services, shared state services and services with states which are customised for individual users. A service-based orchestration is a multi-threaded computation which invokes remote services in order to deliver results back to a user (publication). In this paper a means of specifying services and reasoning about the correctness of orchestrations over stateless services is presented. As web services are potentially unreliable the termination of even finite orchestrations cannot be guaranteed. For this reason a partial-correctness powerdomain approach is proposed to capture the semantics of recursive orchestrations.

Web Services and Incerta Spiriti: A Game Theoretic Approach to Uncertainty

A web-service is a remote computational facility which is made available for general use by means of the internet. An orchestration is a multi-threaded computation which invokes remote services. In this paper game theory is used to analyse the behaviour of orchestration evaluations when underlying web-services are unreliable. Uncertainty profiles are proposed as a means of defining bounds on the number of service failures that can be expected during an orchestration evaluation. An uncertainty profile describes a strategic situation that can be analyzed using a zero-sum angel-daemon game with two competing players: an angel a whose objective is to minimize damage to an orchestration and a daemon d who acts in a destructive fashion. An uncertainty profile is assessed using the value of its angel daemon game. It is shown that uncertainty profiles form a partial order which is monotonic with respect to assessment.

Analysing Web-Orchestrations Under Stress Using Uncertainty Profiles

An orchestration is a multi-threaded computation that invokes a number of remote services. In practice, the responsiveness of a web-service fluctuates with demand; during surges in activity service responsiveness may be degraded, perhaps even to the point of failure. An uncertainty profile formalizes a user's perception of the effects of stress on an orchestration of web-services; it describes a strategic situation, modelled by a zero-sum angel–daemon game. Stressed web-service scenarios are analysed, using game theory, in a realistic way, lying between over-optimism (services are entirely reliable) and over-pessimism (all services are broken). The ‘resilience’ of an uncertainty profile can be assessed using the valuation of its associated zero-sum game. In order to demonstrate the validity of the approach, we consider two measures of resilience and a number of different stress models. It is shown how (i) uncertainty profiles can be ordered by risk (as measured by game valuations) and (ii) the structural properties of risk partial orders can be analysed.

Benchmarking de uma aproximação de ticketing as a service (Taas)

Dissertação de natureza científica realizada para obtenção do grau de Mestre em Engenharia de Redes de Computadores e Multimédia

TOWARD SEMANTIC WEB SERVICES AS MVC APPLICATIONS: FROM OWL-S VIA UML

OWL-S is an application of OWL, the Web Ontology Language, that describes the semantics of Web Services so that their discovery, selection, invocation and composition can be automated. The research literature reports the use of UML diagrams for the automatic generation of Semantic Web Service descriptions in OWL-S. This paper demonstrates a higher level of automation by generating complete complete Web applications from OWL-S descriptions that have themselves been generated from UML. Previously, we proposed an approach for processing OWL-S descriptions in order to produce MVC-based skeletons for Web applications. The OWL-S ontology undergoes a series of transformations in order to generate a Model-View-Controller application implemented by a combination of Java Beans, JSP, and Servlets code, respectively. In this paper, we show in detail the documents produced at each processing step. We highlight the connections between OWL-S specifications and executable code in the various Java dialects and show the Web interfaces that result from this process.

Towards extended machine translation model for next generation world wide web

In this paper, we proposed a Data Translation model which potentially is a major promising web service of the next generation world wide web. This technique is somehow analogy to the technique of traditional machine translation but it is far beyond what we understand about machine translation in the past and nowadays in terms of the scope and the contents. To illustrate the new concept of web services based data translation, a multilingual machine translation electronic dictionary system and its web services based model including generic services, multilingual translation services are presented. This proposed data translation model aims at achieving better web services in easiness, convenience, efficiency, and higher accuracy, scalability, self-learning, self-adapting.

End-user control in web-based electronic services : a case study

This paper reports a case study of end-user control in delivery of Web-based electronic services. The case study concentrates the adoption of a Web-based electronic system being implemented in processing student’s admission applications on a Web site. The end-user’s control interface provides information on the detail existing in the Web-based electronic service. This insight into end-user synthesis in developing effective control in Web service environment relates to ease of use in doing the task. To assume the leverage of end-user control strictly on the basis of the Web service usage would limit the purpose of understanding. Rather it is suggested that it would be better to develop an approach to study the end-user ease of use interface in doing the task with the user’s perception towards Web-based interactivity.

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.