Applications that cross the boundaries of different computing machines, operating systems, and programming languages are increasingly the norm. As a result, the need for what might be called bridging technologies to d...
详细信息
Applications that cross the boundaries of different computing machines, operating systems, and programming languages are increasingly the norm. As a result, the need for what might be called bridging technologies to develop software that works across heterogeneous environments has become more compelling. The Common Object Request Broker Architecture is one such technology that is both robust and commercially available. CORBA essentially describes how client applications can invoke operations on server objects using the services of an intermediary known as an Object Request Broker, or ORB. This article introduces CORBA by describing its key components. It then reviews the boundaries it helps to bridge. It concludes by comparing CORBA with a number of other bridging technologies available today.
This paper presents a mobile agent approach that aims at satisfying the following requirements of open Internet-based electronic service markets: the mobile agent system should be usable by any Internet user without a...
详细信息
ISBN:
(纸本)3540628037
This paper presents a mobile agent approach that aims at satisfying the following requirements of open Internet-based electronic service markets: the mobile agent system should be usable by any Internet user without a need for specifically configurated non-standard software tools. It should reduce costs in mobile computing environments and therefore enhance overall efficiency. It should suit well to an electronic service market where local services are commercially offered and business transactions predominate the interaction between customers and suppliers. As a part of the project OSM (Open Service Model), mobile agents are built on top of two well-established technologies: CORBA and Java. The first is used as a conceptual framework for interoperability, the latter as the programming environment. Since Java does not provide the necessary persistency of execution state, the concept of OSM service profiles is used to embed Java classes and to transfer a coarse-grained execution context in a secure and efficient manner.
In mobile collaborative applications, collaborating agents can move across heterogeneous networks. The collaborating agents also keep changing their roles depending on the work to be performed at that time. I n such s...
详细信息
Advances in directory services, caching and replication, and multicasting technologies promise to improve the speed and robustness of the Web's infrastructure. This article examines the technical issues of two imp...
详细信息
Advances in directory services, caching and replication, and multicasting technologies promise to improve the speed and robustness of the Web's infrastructure. This article examines the technical issues of two important approaches - Caching and replication.
By integrating the many different technologies and approaches involved in electronic education and commerce, we can effectively support advanced applications in these areas. This paper describes an architecture which ...
详细信息
By integrating the many different technologies and approaches involved in electronic education and commerce, we can effectively support advanced applications in these areas. This paper describes an architecture which can be used to facilitate the specification, execution, and distribution of incremental trade documents among heterogeneous interchanges. We argue that the conventional, top-down, centralized approach to workflow, in its current state, is not suitable to support the undetermined nature of an advanced trade application. What this approach lacks is a unified object-oriented model which can be used to design interoperable trading systems with a single set of well-defined abstractions. This paper, in an attempt to overcome the limitations imposed by the conventional approach, presents an overview of principles relating to object interoperability, semantic heterogeneity, and the document-centric paradigm associated with trade documents. A view object model and its relevant components are also discussed.
Parallel programming on loosely coupled distributedsystems is becoming a viable approach with the rapid increase in network speeds and availability of large amounts of unused CPU capacity on individual workstations. ...
详细信息
Parallel programming on loosely coupled distributedsystems is becoming a viable approach with the rapid increase in network speeds and availability of large amounts of unused CPU capacity on individual workstations. Parallel programs are often written for a specific configuration of the distributed system such as the number of nodes, their relative speeds and their network connections. These programs perform poorly when there is a change in the configuration or when they are taken to a system other than what they are intended for. We propose a new paradigm which can express the scale of a program as a part of the program itself. The scale of the program is specified in an abstract manner for an arbitrary number of nodes, their relative speeds and their network connections. The runtime system uses this information to decide the actual scale of program on a given distributed system.
In this paper we investigate the efficiency of two solution approaches to infinite stochastic Petri nets: the matrix-geometric method and the spectral expansion method. We first informally present infinite stochastic ...
详细信息
In this paper we investigate the efficiency of two solution approaches to infinite stochastic Petri nets: the matrix-geometric method and the spectral expansion method. We first informally present infinite stochastic Petri nets, after which we describe, using uniform notation, the matrix-geometric and the spectral expansion method. We put special emphasis on the numerical aspect of the solution procedures. Then, we investigate the suitability of these approaches to account for batch-movements of tokens. We then compare the two solution approaches when applied to a larger modelling study of a fault-tolerant computer system. It turns out that the spectral expansion method is favorable in all cases, especially when more heavily loaded systems are studied and when batch arrivals are incorporated in the model. To the best of our knowledge, this paper is the first to compare the spectral expansion method, as advocated by Mitrani and Chakka, with the Latouche-Ramaswami algorithm for the matrix-geometric case. Furthermore, our comparisons go well beyond the usual textbook cases, since we are able to generate, with our tool SPN2MGM, models that are much larger than those that have been assessed in the past.
作者：
Chris McDonaldKamran KazemiProgramming
Languages and Systems Group Department of Computer Science The University of Western Australia Crawley Western Australia 6907
The parallel programming community has long recognized the need for a simple programming environment offering interprocess communication between heterogeneous systems. As the Parallel Virtual Machine environment, PVM,...
ISBN:
(纸本)9780897918893
The parallel programming community has long recognized the need for a simple programming environment offering interprocess communication between heterogeneous systems. As the Parallel Virtual Machine environment, PVM, has emerged to meet this goal, an increasing number of educational institutions are choosing PVM to support their teaching of parallel and distributed computing using networks of workstations. However, it is often the nature of PVM's design and implementation that can severely limit its success in a teaching environment. This paper first motivates and then describes improvements to the PVM environment which increase both robustness and efficiency in an educational setting.
In mobile collaborative applications, collaborating agents can move across heterogeneous networks. The collaborating agents also keep changing their roles depending on the work to be performed at that time. In such si...
详细信息
In mobile collaborative applications, collaborating agents can move across heterogeneous networks. The collaborating agents also keep changing their roles depending on the work to be performed at that time. In such situations, a simple and flexible handling of the transition between heterogeneous environments and roles is required. This paper proposes PolyConstraints, a design pattern to handle the generic problem of transitions across multiple network environments and roles.
暂无评论