2457108
An object-oriented real-time distributed simulation of cellular phone switching system
The cellular phone network is a distributed system which is composed of three kinds of subsystems, a mobile phone unit, a base site station and a MSC (mobile switching center). A class of cellular phone switching systems, was chosen as the system to be studied. SUN workstations and the UNIX operating system with X windows have been employed as the core of the development environment. The object-oriented (OO) paradigm and C++ were chosen to develop the simulation. UICCELL was developed as an object-oriented system for cellular phone switching real-time multitasking simulation. UICCELL has been fully implemented and is currently running on an Ethernet LAN. A central monitor is created on the screen to manipulate and monitor the simulator. The graphical user interface displays the configuration of UICCELL and the status of processors, channels, etc. The current implementation contains 60 classes and about 20,000 lines of C++ code.<<ETX>>
45899286
Computer Supported Cooperative Work Oriented Architecture
44831800
Formal Collaborative Production Environment
18643244
An Empirical Performance Study on PSIM
It is well known that errors caught in the early stages of system development life cycle greatly helped reduce the expense for later error fixing and mitigate risks and complications. Performance analysis is one of the methods to ensure satisfactory system performance that can avoid redesign and patch in the later stage of system development when performance problems emerge. Much work has been done to address such concerns collectively known as the 'performance engineering' problem. However, a comprehensive method is still needed to provide an end-to-end support for performance evaluation on software architecture design. Automated tools to support the method must be developed, and its validation must be carefully planned and conducted. In response to this need, we propose our approach, PSIM (performance simulation and modeling). PSIM is a performance simulation and modeling tool that integrated performance properties into software architecture specifications expressed in several major UML diagrams. PSIM models can be transformed into Colored GSPN (colored generalized stochastic Petri nets) via an automated tool. As a result, the Colored GSPN models can be simulated to perform model-based performance evaluation. In this paper PSIM is first briefly reviewed and illustrated through modeling a web-based electronic conferencing system, called M-Net, to derive performance metrics. We then conduct runtime performance testing to the implementation of M-Net and compare the simulation results against the runtime testing data. PSIM is shown to be effective in predicting system performance and in identifying system performance bottlenecks through this experimentation.
36323277
Event-Based Traceability for Managing Evolutionary Change
Although the benefits of requirements traceability are widely recognized, the actual practice of maintaining a traceability scheme is not always entirely successful. The traceability infrastructure underlying a software system tends to erode over its lifetime, as time-pressured practitioners fail to consistently maintain links and update impacted artifacts each time a change occurs, even with the support of automated systems. This paper proposes a new method of traceability based upon event-notification and is applicable even in a heterogeneous and globally distributed development environment. Traceable artifacts are no longer tightly coupled but are linked through an event service, which creates an environment in which change is handled more efficiently, and artifacts and their related links are maintained in a restorable state. The method also supports enhanced project management for the process of updating and maintaining the system artifacts.
10801320
Rule-mitigated collaboration technology
The design of an appropriate paradigm for collaboration ultimately stands or falls on the question of whether human users are able to cooperate effectively with it. In this work, we begin with a paradigm of interaction in which human collaborators have shown themselves facile. This paradigm is based on the formal meeting protocol commonly known as parliamentary procedure or Robert's Rules of Order (RRO). These rules are at the same time descriptive and prescriptive of effective meeting behavior. Electronic meeting systems, likewise, have to manage time and communicative resources, maintain logs, and produce artifacts that constitute the fruit of the collaboration. The technology disclosed here facilitates the generation of coauthored artifacts (documents, designs, project plans, etc.) as the direct outcome of the collaborative process. The efficacy of rule-mitigated collaboration technology is based on four major components: an extended parliamentary procedure rule set, a scoping policy and set of application programming interfaces, an object-based client-server architecture, and an M-Net synchronous meeting environment.
10317156
A research on Collaboration Net
We present research on computer-supported cooperative work by introducing an approach to the multimedia based net-centric conference environment-Collaboration Net. Some basic definitions of the distributed Web-based meeting are provided, and the properties of this kind of collaboration are given. We explain problems associated with the well-known yet old-fashioned parliamentary procedure, Robert's Rules of Order, which must be formally modeled and adapted to the modern net-centric virtual conference where time synchronism is hard to enforce. A prototype of our Web-browser based approach to developing the Collaboration Net is also briefly presented. Finally, research challenges in this area are highlighted.
10778870
An empirical performance study for validating a performance analysis approach: PSIM
Performance analysis gains more attention in recent years by researchers who focus their study on the early software development stages to mitigate the risk of redesign as problems emerge later. Previously we proposed PSIM (a performance simulation and modeling tool) that integrated performance properties into software architecture specifications expressed in several major UML diagrams. PSIM models can be transformed into colored GSPN and the colored GSPN models can then be simulated to perform model-based performance evaluation. In this paper we briefly review the PSIM approach and apply it to model a Web-based conferencing system, called M-Net, to derive performance metrics. We then conduct runtime performance testing to the implementation of M-Net and compare the simulation data to runtime testing data. The comparison results show the effectiveness of the PSIM method in predicting system performance and identifying system performance bottlenecks.