The NZDIS project: an agent-based distributed information systems architecture

The Foundation for Intelligent Physical Agents (FIPA) is a non-profit organization aimed at producing standards for the interoperation of heterogeneous software agents. The FIPA Semantic Language (SL) is a communication language that uses the redefined 'content' parameter of the FIPA Agent Communication Language (ACL). The FIPA SL is also a most widely used standard language between the FIPA-based agent platforms. JADE, the famous agent platform in agent paradigms, also applies the FIPA SL. The agent platforms should follow the FIPA specifications such as FIPA ACL and FIPA SL. However there are no communication methods between the heterogeneous platforms that employ the different languages at present. For communication between the heterogeneous platforms that employ the different languages we should fix the source codes directly. Thus, we propose the FIPA SL-to-XML converting module. The converting module makes the FIPA SL-based agent platforms communicate with the XML-based web applications and platforms. We have the employed converting module in XML-based the Component -based Autonomic Layered Middleware (CALM). We also propose the starting point of the integration module that can combine the heterogeneous language-based platforms.

It has been difficult to objectively assess the real value or maturity of the Object Management Group's Object Management Architecture (OMA). While experience reports have appeared in the literature, these have focused more on the functionality of the end-system than on systematically exploring the strengths and weaknesses of the OMA, and providing practical guidelines on the effective use of the OMA for specific software-engineering problems. In this paper we describe a case study in the use of the OMA to integrate legacy software components into a distributed object system. We assess the OMA in this problem context, and indicate strengths and weaknesses of the specification and current implementations. We extrapolate our experience to a broader class of component-based software systems, and recommend an architectural strategy for the effective use of the OMA to this class of systems.

In the past, research on agent-oriented software engineering had been widely lacking touch with the world of industrial software development. Recently, a cooperation has been established between the Foundation of Intelligent Physical Agents (FIPA) and the Object Management Group (OMG) aiming to increase acceptance of agent technology in industry by relating to de facto standards (object-oriented software development) and supporting the development environment throughout the full system lifecycle. As a first result of this cooperation, we proposed AGENT UML [1; 20], an extension of the Unified Modeling language (UML), a de facto standard for object-oriented analysis and design. In this paper, we describe the heart of AGENT UML, i.e., mechanisms to model protocols for multiagent interaction. Particular UML extensions described in this paper include protocol diagrams, agent roles, multithreaded lifelines, extended UML message semantics, nested and interleaved protocols, and protocol templates.

This article presents an approach for inter-agent communication and inter-platform agent migration based on IEEE FIPA (Foundation for Intelligent Physical Agents) Agent Communication Language (ACL) messages. The promising features of IEEE FIPA standards that support open, flexible, and interoperable agent communication and migration are discussed in the paper. Messages for agent communication and migration, platform architecture that deliver and manage these messages, and the main procedure of processing a mobile agent message are also introduced. An application example, in which a mobile agent visits multiple hosts and travels via mobile agent messages, simulates a mobile agent for remote data processing. This example shows the feasibility, simplicity, and openness of the presented approach for mobile agent migration. Using FIPA ACL messages for agent migration in FIPA compliant agent systems simplifies agent platform, reduces development effort, and easily achieves inter-platform migration through well-designed communication mechanisms provided in the agent platform.

Traditionally, most definitions seeking to characterize middleware suggest that it is the software that facilitates remote database access and systems transactions. More recently, the term has come to be associated-somewhat limitingly-with distributed platforms such as the Open Software Foundation's Distributed Computing Environment (DCE) and the Object Management Group's Common Object Request Broker Architecture (CORBA). And some have loosely applied it to systems as diverse as workflow support environments and even to the Web itself. We believe the essential role of middleware is to manage the complexity and heterogeneity of distributed infrastructures and thereby provide a simpler programming environment for distributed-application developers. It is therefore most useful to define middleware as any software layer that is placed above the distributed system's infrastructure-the network OS and APIs-and below the application layer.

DIMMA - A Distributed Interactive Multi-Media Architecture - is an open distributed processing (ODP) platform that facilitates the production of distributed applications. It has particular support for those applications that have soft real-time constraints, and those that make use of multi-media. DIMMA consists of a portable layer of distribution engineering (middleware), together with tools to interface applications to this engineering. The most popular commercial ODP platform is the Common Object Request Broker Architecture (CORBA) whose definition is managed by the Object Management Group (OMG). In recognition of this popularity, DIMMA supports a CORBA compliant API so that CORBA applications may be easily ported to or from the DIMMA platform. This paper describes the example implementation of DIMMA. It gives an overview of the motivations behind the design of DIMMA and then highlights some key features of the DIMMA implementation. It concludes with a brief analysis of DIMMA's performance

There is a growing international interest in using coupled, multidisciplinary computer simulations for a variety of purposes, including nuclear reactor safety analysis. Reactor behaviour can be modeled using a suite of computer programs simulating phenomena or predicting parameters that can be categorized into disciplines such as Thermalhydraulics, Neutronics, Fuel, Fuel Channels, Fission Product Release and Transport, Containment and Atmospheric Dispersion, and Severe Accident Analysis. Traditionally, simulations used for safety analysis individually addressed only the behaviour within a single discipline, based upon static input data from other simulation programs. The limitation of using a suite of stand-alone simulations is that phenomenological interdependencies or temporal feedback between the parameters calculated within individual simulations cannot be adequately captured. To remove this shortcoming, multiple computer simulations for different disciplines must exchange data during runtime to address these interdependencies. This article describes the concept of a new framework, which we refer to as the “Backbone,” to provide the necessary runtime exchange of data. The Backbone, currently under development at AECL for a preliminary feasibility study, is a hybrid design using features taken from the Common Object Request Broker Architecture (CORBA), a standard defined by the Object Management Group, and the Message Passing Interface (MPI), a standard developed by a group of researchers from academia and industry. Both have well-tested and efficient implementations, including some that are freely available under the GNU public licenses. The CORBA component enables individual programs written in different languages and running on different platforms within a network to exchange data with each other, thus behaving like a single application. MPI provides the process-to-process intercommunication between these programs. This paper outlines the different CORBA and MPI configurations examined to date, as well as the preliminary configuration selected for coupling 2 existing safety analysis programs used for modeling thermal–mechanical fuel behavior and fission product behavior respectively. In addition, preliminary work in hosting both the Backbone and the associated safety analysis programs in a cluster environment are discussed.

Today, more and more distributed computer applications are being modeled and constructed using real‐time principles and concepts. In 1989, the Object Management Group (OMG) formed a Real‐Time Special Interest Group (RT SIG) with the goal of extending the Common Object Request Broker Architecture (CORBA) standard to include real‐time specifications. This group's most recent efforts have focused on the requirements of dynamic distributed real‐time systems.One open problem in this area is resource access synchronization for tasks employing dynamic priority scheduling. This paper presents two resource synchronization protocols that the authors have developed which meet the requirements of dynamic distributed real‐time systems as specified by Dynamic Scheduling Real‐Time CORBA (DSRT CORBA). The proposed protocols can be applied to both Earliest Deadline First (EDF) and Least Laxity First (LLF) dynamic scheduling algorithms, allow distributed nested critical sections, and avoid unnecessary runtime overhead. In order to evaluate the performance of the proposed protocols, we analyzed each protocol's schedulability. Since the schedulability of the system is affected by numerous system configuration parameters, we have designed simulation experiments to isolate and illustrate the impact of each individual system parameter. Simulation experiments show the proposed protocols have better performance than one would realize by applying a schema that utilizes dynamic priority ceiling update. Copyright © 2004 John Wiley & Sons, Ltd.

새로운 패러다임의 시스템 개발 접근 방법은 OMG(Object Management Group)에서 MDA(Model Driven Architecture)로 표준화하고 있다. MDA의 핵심 기술은 모델 중심의 시스템 구현을 위한 기술 구조를 정의하는 것으로 시스템의 설계 및 명세에 대한 구현 기술을 플랫폼 독립적 모델(PIM : Platform Independent Model)로 설계한 후, 구현 환경에 적합한 플랫폼 종속적 모델(PSM : Platform Specific Model)로 설계하여 구현환경에 맞는 언어로 변환하는 기술이다. MDA의 핵심인 MOF(Meta-Object Facility), UML, XMI(XML Metadata Interchange), CWM(Common Warehouse Metamodel) 표준 등이 포함된다. MDA 지원 자동화 툴들은 위의 정보들을 갖고 변환 작업을 수행한 후 실행 가능한 시스템으로 생산해 내는 것이다.[1] 본 논문에서는 MDA기반 접근 방법을 적용하여 학사관리 시스템을 설계 및 구현하고, MDA기반 접근 방법에 대한 모델링의 중요성을 강조하였다. 또한 소프트웨어를 효율적으로 개발하는 방법을 제시하여 플랫폼 독립적 모델(PIM)로 작성하고, 플랫폼 종속적 모델(PSM)을 J2EE 플랫폼 기반의 EJB(Enterprise Java Beans)로 변환하는 과정 등을 제시하였다. MDA를 지원하는 자동화 툴 및 편집기(Together Architect 2006 for Eclipse, Edit plus 2)와 데이터베이스 모델링 툴(ER/WIN 4.1)을 사용하여 시스템 설계 및 구현을 하였으며, 전통적 개발 프로세스와 MDA 기반 개발 프로세스에 대한 유효성 분석 결과를 제시하였다. The system development approach method of the new paradigm, as being standardizing MDA(Model Driven Architecture) in OMG(Object Management Group), the core technique of MDA definite technique structure for system materialization focusing on Model, is to build the design and the statement for system in PIM(Platform Independent Model), Materialization technique, and to build PSM(Platform Specific Model) adapt to materialization environment, and then to be the technique transforming into language Platform suitable to materialization environment. It includes MOF(Meta-Object Facility), UML, XMI(XML Metadata Interchange), CWM(Common Warehouse Metamodel), the core of MDA. Though these operations MDA support automatic tools product the practicable system after carrying out transform operation with the above information. In this thesis, it will be approached how to design and materialize the Bachelor management system based on MDA and the importance of modeling should be emphasized by applying to the approach method based on MDA. It should be suggested how to develop software efficiently, written it out in PIM, and suggested the process transforming PSM into EJB by J2EE Platform. The system is designed and implemented using automatic tool, edit machine(Together Architect 2006 for Eclipse, Edit plus2) supporting MDA and Database Modeling tool(ER/WIN 4.1). In conclusion, it should be suggested the efficiency analysis result for development process of traditional and based on MDA.

A multi-agent system for the integration of distributed environmental information

The Agent Communication Language (ACL) proposed by the Foundation for Intelligent Physical Agents (FIPA) is the most complete attempt to create a universally accepted standard so far. Nevertheless, this standard shows some shortcomings which are probably hindering an even greater impact upon the scientific research dealing with multiagent systems. Although agreeing with the mainstream view that analyzes agent communication in terms of communicative acts, we part from FIPA’s assumptions about the semantics, as we shift the focus from affecting communicating agents’ mental states to modifying the commitments binding them to each other. We show that our commitment-based framework is powerful enough to allow for the main FIPA communicative acts and provides a semantics which overcomes some of the problems that are currently affecting the standard.KeywordsTemporal LogicMultiagent SystemAgent CommunicationMessage ExchangeIllocutionary ForceThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

The distributed object standards Component Object Model (COM) and Common Object Request Broker Architecture (CORBA) apply object technology to design and use software components. While COM forms a good front end for the Microsoft Systems, CORBA is well suited for middle tier and back end Unix servers. By integrating them, the user can get a combination of the best attributes of both the systems. Bridging software is needed to transparently couple components from both the systems. This paper discusses a static method of achieving COM/CORBA interworking using a generic IDL compiler. It maps the COM and CORBA IDLs onto an intermediate representation from which stubs and skeletons are generated. Further, threading is used to allow multiple COM clients to contact a single CORBA server using Internet Interoperable Protocol / Transmission Control Protocol (IIOP/TCP) as a communication medium. To improve the networking speed and to bring about multicasting, IIOP/UDP has also been tried as a communication medium. The Object Reference (OR) from the implementation repository (IMR) and the Object Identifier (OID) from the registry have also been cached to improve the speed of the name lookup mechanism.

The Telecommunications Management Network (TMN) has been developed as the framework to support administrations in managing telecommunications networks. It suggests the use of OSI Systems Management (OSI-SM) as the technology for management information exchanges. Distributed object technologies, such as the Common Object Request Broker architecture (CORBA), address the use of software application program interfaces (APIs) in addition to interoperable protocols. Their use in TMN has been the subject of intensive research in previous years, with most approaches focusing on interoperability aspects with OSI-SM. We examine the issues behind using distributed object technologies in TMN via a native fashion, with network elements supporting distributed objects directly, e.g., a CORBA to the switch approach. The proposed solution tries to maintain the full OSI-SM expressive power in a way that other solutions have not attempted before. Performance and scalability issues are considered, while the approach has been validated through implementation.

In this paper, we present the management of mobile switching center (MSC) trunks and trunk groups in cellular and personal communications systems (PCS) networks. We discuss platform-centered network management approaches based on simple network management protocol (SNMP) and common management information protocol (CMIP). We also describe the Common Object Request Broker Architecture (CORBA <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∗</sup> ) solution for distributed computing and implementation of distributed objects based on Object Management Group (OMG) Interface Definition Language. <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∗</sup> CORBA appears to provide a better backbone for manager and agent applications than CMIP. In higher-level designs, the manager and agent applications can be adapted to a CMIP-style interface.

A growing class of real-time systems require end-to-end support for various quality-of-service (QoS) aspects, including bandwidth, latency, jitter and dependability. Applications include command and control, manufacturing process control, videoconferencing, large-scale distributed interactive simulation, and testbeam data acquisition. These systems require support for stringent QoS requirements. To meet this challenge, developers are turning to distributed object computing middleware, such as the Common Object Request Broker Architecture, an Object Management Group (OMG) industry standard. In complex real-time systems, DOC middleware resides between applications and the underlying operating systems, protocol stacks and hardware. CORBA helps decrease the cycle time and effort required to develop high-quality systems by composing applications using reusable software component services rather than building them entirely from scratch. The Real-Time CORBA specification includes features to manage CPU, network and memory resources. The authors describe the key Real-Time CORBA features that they feel are the most relevant to researchers and developers of distributed real-time and embedded systems.