Architecture for a Web-accessible simulation environment

Despite the dynamic and interactive nature of the language underlying applets, the typical applet still performs a fixed set of operations. Users cannot easily reconfigure such a system to perform “what if” experiments or gather statistical or timing information for an experiment. Thus, while Java and the Web support dynamic interactions and enable exciting capabilities in educational software, few applications built on them exploit these capabilities. The article describes CSLab, a proof-of-concept prototype of a simulation environment that is easy to use, dynamic, and Web-accessible. It is designed from the ground up to exploit the inherent dynamic behavior of Java and the Web and to let end users capitalize on this behavior. The authors' goal was to build a framework within which to create, configure, and execute experiments, but instead of the physical sciences they focused on experimental algorithmics. The CSLab executable is a framework for creating various simulation experiments using available modules     

Defining business requirements quickly and accurately

A critical task in an enterprise IT architecture project is to identify and understand key business requirements to ensure that the planned IT systems will fully support and evolve with the business. This article illustrates a more effective approach: leveraging the combined power of value chain, which captures the static business view, and use cases, which animate the business model. In this way, enterprise architects can rapidly define the business's main elements and understand how key systems interact to support business activities.     

An integrated environment for requirements engineering

An integrated environment for requirements engineering that supports participatory development activities is described. The environment helps ensure quality by supporting and encouraging group participation and interaction. The computer-supported cooperative-work environment supports the development and analysis of system-and-software-level requirements for large, complex applications. It encompasses and coordinates all aspects of requirements development, from conceptual inspiration, through planning, to specific project details. Case studies of groups using this environment show it can support requirements engineering for groups of users determining system-level requirements for large, complex systems     

Standards-a standard environment for software production

The author reviews what has been accomplished in recent years to develop a standard environment. He examines the current state of affairs to determine why problems in meeting cost, schedule, and technical performance goals persist. He makes some suggestions for dealing with these problems and concludes that a standard for maintainable code and more skilled personnel are needed to deal with them effectively     

Developing a high-level fault simulation standard

Recent developments in deep-submicron technology challenge current integrated circuit testing methods. The increasing complexity of designed systems makes test development more time-consuming. Moreover, nanometer technology introduces new defects or higher data rate errors. To reduce manufacturing costs and time to market, we must develop efficient fault detection and location methods. Using high-level fault simulation stimulates the development of new, fast test-generation algorithms that take into consideration functional features of the system under test or its components. Moreover, all synthesis tools migrate to higher levels, and we believe that this will improve ATPG tools as well     

Reducing object storage requirements in a multi-user environment

Many Smalltalk implementations store objects in a large file called a virtual image. Each user must have a copy of the virtual image to execute. Since the image can exceed a megabyte in size, considerable disk space is required to support such a system in a multi-user environment. In this paper, a method is described which can reduce storage requirements for systems which use generation scavenging as a memory reclamation technique. This method also improves the performance of the checkpoint operation and offline garbage-collection.     

Escort: an environment for specifying communication requirements

A prototype specification support system, Escort, is described that incorporates novel validation, verification, and simplification methods for telecommunications software specifications. Unix was adapted as the operating system for Escort, and many of Escort's tools were designed and implemented by making full use of the Unix facilities. Escort identifies three kinds of specification errors: errors in the grammar of the specification language, called syntax errors; those that degrade consistency and completeness, called logical errors; and those that degrade correctness, called semantic errors. It detects these errors using syntax analysis, validation, and verification, respectively     

A simulation environment for multimodeling

Large-scale systems are typically quite difficult to model. Hierarchical decomposition has proven to be one successful method in managing model complexity, by refining model components into models of the same type as the lumped model. Many systems, however, cannot be modeled using this approach since each abstraction level is best defined using a different modeling technique. We present amultimodel approach which overcomes this limitation, and we illustrate the technique using a fairly simple scenario: boiling water. State and phase trajectories are presented along with an implementation using theSimPack simulation toolkit. Multimodeling has provided us with a mechanism for building models that are capable of producing answers over a wide range of fidelity. The author is grateful for partial funding of this research through a grant from the Florida High Technology Council.     

Parsec: a parallel simulation environment for complex systems

Design and development costs for extremely large systems could be significantly reduced if only there were efficient techniques for evaluating design alternatives and predicting their impact on overall system performance metrics. Due to the systems' analytical intractability, simulation is the most common performance evaluation technique for such systems. However, the long execution times needed for sequential simulation models often hampers evaluation. The slow speeds of sequential model execution have led to growing interest in the use of parallel execution for simulating large-scale systems. Widespread use of parallel simulation, however; has been significantly hindered by a lack of tools for integrating parallel model execution into the overall framework of system simulation. Another drawback to widespread use of simulations is the cost of model design and maintenance. The simulation environment the authors developed at UCLA attempts to address some of these issues. It consists of three primary components: a parallel simulation language called Parsec (parallel simulation environment for complex systems), its GUI, called Pave, and the portable runtime system that implements the simulation algorithms     

Building a virtual environment for endoscopic sinus surgery simulation

Advanced display technologies have made the virtual exploration of relatively complex models feasible in many applications. Unfortunately, only a few human interfaces allow natural interaction with the environment. Moreover, in surgical applications, such realistic interaction requires real-time rendering of volumetric data—placing an overwhelming performance burden on the system. We report on our advances towards developing a virtual reality system that provides intuitive interaction with complex volume data by employing real-time realistic volume rendering and convincing forece feedback (haptic) sensations. We describe our methods for real-time volume rendering, model deformation, interaction, and the haptic devices, and demonstrate the utilization of this system in the real-world application of Endoscopic Sinus Surgery (ESS) simulation.     

A requirements engineering environment within a tightly integrated SDE

This paper describes the outside functionality of an RE environment within an integrated software development environment. Furthermore, an integrator tool for the transition to software system architecture modelling is presented. The tools discussed are editors, analysers, executors, monitors, and integration tools of different characteristics for horizontal integration (within RE) and vertical integration (to architecture modelling). All tools are tightly integrated and work incrementally, therefore allowing different forms of construction and modification processes and giving substantial support.     

Towards an environment interface standard for agent platforms

We introduce an interface for connecting agent platforms to environments. This interface provides generic functionality for executing actions and for perceiving changes in an agent’s environment. It also provides support for managing an environment, e.g., for starting, pausing and terminating it. Among the benefits of such an interface are (1) standard functionality is provided by the interface implementation itself, and (2) agent platforms that support the interface can connect to any environment that implements the interface. This significantly reduces effort required from agent and environment programmers as the environment code needed to implement the interface needs to be written only once. We propose that the interface presented may be used as a standard that enables agents to control entities in environments. Our starting point for designing such a generic interface is based on a careful study of the various interfaces used by different agent programming languages to connect agent programs to environments. We discuss several case studies that use our interface (an elevator simulator, the well-known agent contest, and an implementation of the interface to connect agents to bots in Unreal Tournament 2004).     

Virtual reality for ambulance simulation environment

Multimedia Tools and Applications - Simulations are beneficial in evaluating clinicians’ empirical competencies through practical skills, prioritizing, and decision-making as part of patient...     

Using simulation‐based experiments for software requirements engineering

We describe the use of simulation‐based experiments to assess the computer support needs of automation supervisors in the United States Postal Service (USPS). Because of the high cost of the proposed system, the inability of supervisors to articulate their computer support needs, and the infeasibility of direct experimentation in the actual work environment, we used a simulation to study end‐user decision making, and to experiment with alternative computer support capabilities. In Phase One we investigated differences between expert and novice information search and decision strategies in the existing work environment. In Phase Two, we tested the impact of computer support features on performance. The empirical results of the two experiments showed how to differentially support experts and novices, and the effectiveness of proposed information systems before they were built. The paper concludes by examining the implications of the project for the software requirements engineering community.     

User requirements for geo-collaborative work with spatio-temporal data in a web-based virtual globe environment

Web-based tools developed in the last couple of years offer unique opportunities to effectively support scientists in their effort to collaborate. Communication among environmental researchers often involves not only work with geographical (spatial), but also with temporal data and information. Literature still provides limited documentation when it comes to user requirements for effective geo-collaborative work with spatio-temporal data. To start filling this gap, our study adopted a User-Centered Design approach and first explored the user requirements of environmental researchers working on distributed research projects for collaborative dissemination, exchange and work with spatio-temporal data. Our results show that system design will be mainly influenced by the nature and type of data users work with. From the end-users' perspective, optimal conversion of huge files of spatio-temporal data for further dissemination, accuracy of conversion, organization of content and security have a key role for effective geo-collaboration.     

Design of a simulation environment for laboratory management by robot organizations

This paper describes the basic concepts needed for a simulation environment capable of supporting the design of robot organizations for managing chemical, or similar, laboratories on the planned U.S. Space Station. The environment should facilitate a thorough study of the problems to be encountered in assigning the responsibility of managing a nonlife-critical, but mission valuable, process to an organized group of robots. In the first phase of the work, we seek to employ the simulation environment to develop robot cognitive systems and strategies for effective multi-robot management of chemical experiments. Later phases will explore human-robot interaction and development of robot autonomy.Supported by NASA-Ames Cooperative Agreement No. NCC 2-525, A Simulation Environment for Laboratory Management by Robot Organizations.