A SOA-Based Platform-Specific Framework for Context-Aware Mobile Applications

Context-aware mobile applications are intelligent applications that can monitor the user’s context and, in case of changes in this context, consequently adapt their behaviour in order to satisfy the user’s current needs or anticipate the user’s intentions. The design of such applications relies on dynamic middleware platforms that consist of a variety of components. These components are distributed in the environment and interoperate by making use of each other’s services. In the A-MUSE project, we defined a design methodology based on MDA principles that relies on a SOA reference architecture for context-aware mobile applications. This paper shows how abstract concepts in the design of such applications can be applied to realize concrete components that guarantee architectural interoperability. We also present a platform-specific framework that uses BPEL, UDDI registry and web services as target technologies to implement our reference architecture

Security in a Distributed Processing Environment

Distribution plays a key role in telecommunication and computing systems today. It has become a necessity as a result of deregulation and anti-trust legislation, which has forced businesses to move from centralised, monolithic systems to distributed systems with the separation of applications and provisioning technologies, such as the service and transportation layers in the Internet. The need for reliability and recovery requires systems to use replication and secondary backup systems such as those used in ecommerce. There are consequences to distribution. It results in systems being implemented in heterogeneous environment; it requires systems to be scalable; it results in some loss of control and so this contributes to the increased security issues that result from distribution. Each of these issues has to be dealt with. A distributed processing environment (DPE) is middleware that allows heterogeneous environments to operate in a homogeneous manner. Scalability can be addressed by using object-oriented technology to distribute functionality. Security is more difficult to address because it requires the creation of a distributed trusted environment. The problem with security in a DPE currently is that it is treated as an adjunct service, i.e. and after-thought that is the last thing added to the system. As a result, it is not pervasive and therefore is unable to fully support the other DPE services. DPE security needs to provide the five basic security services, authentication, access control, integrity, confidentiality and non-repudiation, in a distributed environment, while ensuring simple and usable administration. The research, detailed in this thesis, starts by highlighting the inadequacies of the existing DPE and its services. It argues that a new management structure was introduced that provides greater flexibility and configurability, while promoting mechanism and service independence. A new secure interoperability framework was introduced which provides the ability to negotiate common mechanism and service level configurations. New facilities were added to the non-repudiation and audit services. The research has shown that all services should be security-aware, and therefore would able to interact with the Enhanced Security Service in order to provide a more secure environment within a DPE. As a proof of concept, the Trader service was selected. Its security limitations were examined, new security behaviour policies proposed and it was then implemented as a Security-aware Trader, which could counteract the existing security limitations.IONA TECHNOLOGIES PLC & ORANG

Modeling Big Data based Systems through Ontological Trading

One of the great challenges the information society faces is dealing with the huge amount of information generated and handled daily on the Internet. Today, progress in Big Data proposals attempt to solve this problem, but there are certain limitations to information search and retrieval due basically to the large volumes handled, the heterogeneity of the information and its dispersion among a multitude of sources. In this article, a formal framework is defined to facilitate the design and development of an Environmental Management Information System which works with an heterogeneous and large amount of data. Nevertheless, this framework can be applied to other information systems that work with Big Data, since it does not depend on the type of data and can be utilized in other domains. The framework is based on an Ontological Web-Trading Model (OntoTrader) which follows Model-Driven Engineering and Ontology-Driven Engineering guidelines to separate the system architecture from its implementation. The proposal is accompanied by a case study, SOLERES-KRS, an Environmental Knowledge Representation System designed and developed using Software Agents and Multi-Agent Systems

OntoTrader

Modern Web-based Information Systems (WIS) are becoming increasingly necessary to provide support for users who are in different places with different types of information, by facilitating their access to the information, decision making, workgroups, and so forth. Design of these systems requires the use of standardized methods and techniques that enable a common vocabulary to be defined to represent the underlying knowledge. Thus, mediation elements such as traders enrich the interoperability of web components in open distributed systems. These traders must operate with other third-party traders and/or agents in the system, which must also use a common vocabulary for communication between them. This paper presents the OntoTrader architecture, an Ontological Web Trading agent based on the OMG ODP trading standard. It also presents the ontology needed by some system agents to communicate with the trading agent and the behavioral framework for the SOLERES OntoTrader agent, an Environmental Management Information System (EMIS). This framework implements a “Query-Searching/Recovering-Response” information retrieval model using a trading service, SPARQL notation, and the JADE platform. The paper also presents reflection, delegation and, federation mediation models and describes formalization, an experimental testing environment in three scenarios, and a tool which allows our proposal to be evaluated and validated

SOPA - a self organizing processing and streaming architecture

This paper describes SOPA, a component framework that is an essential part of the lecture recording system E-Chalk. It envisiones a general processing and streaming architecture featuring autonomous assembly of stream processing components. The goal is to provide an easy to use framework where dynamically organized processing graphs are build out of components from various distributed sources. Based on state-of-the-art solutions for component based software development the system simplifies the implementation and the configuration of multimedia streaming applications and associated tools. It supports stream synchronization transparently while extending components are installed on the fly according to the existing requirements that may change at any time

Adaptive object management for distributed systems

This thesis describes an architecture supporting the management of pluggable software components and evaluates it against the requirement for an enterprise integration platform for the manufacturing and petrochemical industries. In a distributed environment, we need mechanisms to manage objects and their interactions. At the least, we must be able to create objects in different processes on different nodes; we must be able to link them together so that they can pass messages to each other across the network; and we must deliver their messages in a timely and reliable manner. Object based environments which support these services already exist, for example ANSAware(ANSA, 1989), DEC's Objectbroker(ACA,1992), Iona's Orbix(Orbix,1994)Yet such environments provide limited support for composing applications from pluggable components. Pluggability is the ability to install and configure a component into an environment dynamically when the component is used, without specifying static dependencies between components when they are produced. Pluggability is supported to a degree by dynamic binding. Components may be programmed to import references to other components and to explore their interfaces at runtime, without using static type dependencies. Yet thus overloads the component with the responsibility to explore bindings. What is still generally missing is an efficient general-purpose binding model for managing bindings between independently produced components. In addition, existing environments provide no clear strategy for dealing with fine grained objects. The overhead of runtime binding and remote messaging will severely reduce performance where there are a lot of objects with complex patterns of interaction. We need an adaptive approach to managing configurations of pluggable components according to the needs and constraints of the environment. Management is made difficult by embedding bindings in component implementations and by relying on strong typing as the only means of verifying and validating bindings. To solve these problems we have built a set of configuration tools on top of an existing distributed support environment. Specification tools facilitate the construction of independent pluggable components. Visual composition tools facilitate the configuration of components into applications and the verification of composite behaviours. A configuration model is constructed which maintains the environmental state. Adaptive management is made possible by changing the management policy according to this state. Such policy changes affect the location of objects, their bindings, and the choice of messaging system

CORBA: a middleware for an heterogeneous cooperative system

Two kinds of heterogeneities interfere with the integration of different information sources, those in systems and those in semantics. They generate different problems and require different solutions. This paper tries to separate them by proposing the usage of a distinct tool for each one (i.e. CORBA and BLOOM respectively), and analizing how they could collaborate. CORBA offers lots of ways to deal with distributed objects and their potential needs, while BLOOM takes care of the semantic heterogeneities. Therefore, it seems promising to handle the system heterogeneities by wrapping the components of the BLOOM execution architecture into CORBA objects.Postprint (published version