1871945
Specifications in software prototyping
Abstract We explore the use of software specifications for software prototyping. This paper describes a process model for software prototyping, and shows how specifications can be used to support such a process via a cellular mobile phone switch example.
17140893
An Aspect-Oriented Approach to Resource Composition in Petri net-based Software Architectural Models
Petri net has been widely used for modeling software systems due to its mathematical soundness and support of various tools. In many cases, performance-related analyses of Petri net for a software system need to consider the resource limitations caused by a specific platform. In terms of aspect-oriented approach, the interference of various resources scattered across a software system can be regarded as a specific concern that is only necessary during its performance-related analysis process. To capture the interactions of resources within the Petri net-based software architectural model, we propose an aspect-oriented resource composition model and the XML-based representation language called the resource extension markup language (ReML) for its description. In our approach, one or more resource composition models can be developed and described in ReML separately from the development of base software architectural models. Through the weaving process, a resource composition model can be applied to extend several Petri net-based software architectural models. The resource weaver generates an augmented Petri net used for analyzing performance characteristics of the extended software architectural model with resource interactions. Our aspect-oriented approach facilitates selecting an optimal or superior resource composition model for a software architectural model, and vice versa, which is illustrated using two exemplary server models
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.
11560314
Distributed systems design using function-class decomposition with aspects
Object-oriented methods are known for their capabilities to encapsulate and manage core concerns of complex software systems. However, they are inadequate in discerning and separating a variety of other cross-cutting concerns. In particular, for distributed systems, a number of important concerns such as synchronization, logging, and security, should be sufficiently treated in the design phase of the software lifecycle in order to ensure high system quality. Often these concerns tend to be overlooked at the design level and consequently scattered across multiple system modules during implementation. Consequently it becomes difficult to connect the set of requirements with the system structure, thus system traceability is reduced. This paper proposes an extension to the function-class decomposition (FCD) method, that is a hybrid method of structured analysis and OO approach, by integrating the concepts of "aspect". "Aspect" is an abstraction mechanism that emerged in recent years from the aspect-oriented programming (AOP) community. This extended method supports separation of functional and non-functional concerns by maintaining two primary views (function-class view and aspect view) at the design stage, and demonstrates the iterative process by applying it to the development of an example system called M-Net that is an Internet-based real-time distributed conferencing system.
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.
8941164
Supporting agent-based distributed software development through modeling and simulation
In today's software engineering environment, it is becoming increasingly commonplace for team members and stakeholders to be distributed in multiple locations and time zones. Under these circumstances, the coordination of software development activities becomes increasingly more complex. One solution uses mobile agent-based tools to support collaborative software engineering tasks, such as requirements management. Despite the fact that development and validation of such tools would be facilitated by the use of modeling and simulation, very little work relating formal methods to agent-based system development has been performed. This paper therefore presents a hierarchical colored Petri Net (CPN) model as a formal framework for agent-based distributed software development, and demonstrates its usefulness by applying the framework to the development of a requirements management system.
553852
Creating a distributed environment using object oriented technology
The paper gives a detailed description of the development of a distributed environment. A brief description of an object oriented technology used in the development of the environment is also presented. The environment described is suitable for rapid prototyping of distributed applications and complete development of distributed software systems. This environment was used in the development of client/server applications and the simulation of a cellular system. The cellular system featured Call-Handoff Cell-spitting and the dynamic allocation of cellular phones in the system.
7769541
A Net Practice for Software Project Management
Technical and managerial complexity increasingly overwhelm project managers. To rein in that complexity, the authors propose PM-Net, a model that captures the concurrent, iterative, and evolutionary nature of software development. It adopts the basic concepts of Petri nets, graphical models of information flow, with extensions to represent both decisions and artifacts.
17968637
Robust localization of multiple events in sensor networks
Localization of events is a canonical problem for sensor networks, especially for applications such as intrusion detection or neighborhood monitoring. We employ a general sensor model which models various types of sensor nodes. However, traditional triangulation method will be unsolvable when the sensor nodes are positioned on a line. To overcome such ill-conditioned cases, we can use MAP or MMSE methods to estimate event locations. Moreover, to locate multiple simultaneous events and overcome the ill-conditioned case when the sensor nodes are collinear, we need to solve a system of nonlinear equations. We propose a novel method which solves this system of nonlinear equations and multiple-event locations can be found. Experiments and error analysis of the method demonstrate the performance of our methods
21116848
Optimal 1-edge fault-tolerant designs for ladders
A graph G* is 1-edge fault-tolerant with respect to a graph G, denoted by 1-EFT(G), if every graph obtained by removing any edge from G* contains G. A 1-EFT(G) graph is optimal if it contains the minimum number of edges among all 1-EFT(G) graphs. The kth ladder graph, Lk, is defined to be the cartesian product of the Pk and P2 where Pn is the n-vertex path graph. In this paper, we present several 1-edge fault-tolerant graphs with respect to ladders. Some of these graphs are proven to be optimal.
9167410
Computing curricula 2001 how will it work for you?
In the fall of 1998, the ACM Education Board and the Educational Activities Board of the IEEE Computer Society appointed representatives to a joint task force to prepare Computing Curricula 2001 (CC2001), the next installment in a series of reports on the undergraduate computer science curriculum that began in 1968 and was then updated in 1978 and 1991. Interim reports on the initial planning of the curriculum were presented at the SIGCSE symposium and the IEEE Frontiers in Education Conference in both 1999 and 2000. The CC2001 Task Force released its first draft report at the 2000 SIGCSE conference and plans to release its penultimate draft at SIGCSE 2001. The purpose of this session is to describe how we expect the recommendations of the report to apply in practice. The panelists represent a range of institutions and can therefore speak to the questions that audience members from similar institutions might have.