Feynman-diagram evaluation in the electroweak theory with computer algebra

The evaluation of quantum corrections in the theory of the electroweak and strong interactions via higher-order Feynman diagrams requires complicated and laborious calculations, which however can be structured in a strictly algorithmic way. These calculations are ideally suited for the application of computer algebra systems, and computer algebra has proven to be a very valuable tool in this field already over several decades. It is sketched how computer algebra is presently applied in evaluating the predictions of the electroweak theory with high precision, and some recent results obtained in this way are summarized.Comment: 7 pages, updated version of proceedings contribution to ACAT 2000, Fermilab, October 200

Usability Evaluation in Virtual Environments: Classification and Comparison of Methods

Virtual environments (VEs) are a relatively new type of human-computer interface in which users perceive and act in a three-dimensional world. The designers of such systems cannot rely solely on design guidelines for traditional two-dimensional interfaces, so usability evaluation is crucial for VEs. We present an overview of VE usability evaluation. First, we discuss some of the issues that differentiate VE usability evaluation from evaluation of traditional user interfaces such as GUIs. We also present a review of VE evaluation methods currently in use, and discuss a simple classification space for VE usability evaluation methods. This classification space provides a structured means for comparing evaluation methods according to three key characteristics: involvement of representative users, context of evaluation, and types of results produced. To illustrate these concepts, we compare two existing evaluation approaches: testbed evaluation [Bowman, Johnson, & Hodges, 1999], and sequential evaluation [Gabbard, Hix, & Swan, 1999]. We conclude by presenting novel ways to effectively link these two approaches to VE usability evaluation

Structured computer-based training in the interpretation of neuroradiological images

Computer-based systems may be able to address a recognised need throughout the medical profession for a more structured approach to training. We describe a combined training system for neuroradiology, the MR Tutor that differs from previous approaches to computer-assisted training in radiology in that it provides case-based tuition whereby the system and user communicate in terms of a well-founded Image Description Language. The system implements a novel method of visualisation and interaction with a library of fully described cases utilising statistical models of similarity, typicality and disease categorisation of cases. We describe the rationale, knowledge representation and design of the system, and provide a formative evaluation of its usability and effectiveness

Operating manual for coaxial injection combustion model

An operating manual for the coaxial injection combustion model (CICM) is presented as the final report for an eleven month effort designed to provide improvement, to verify, and to document the comprehensive computer program for analyzing the performance of thrust chamber operation with gas/liquid coaxial jet injection. The effort culminated in delivery of an operation FORTRAN IV computer program and associated documentation pertaining to the combustion conditions in the space shuttle main engine. The computer program is structured for compatibility with the standardized Joint Army-Navy-NASA-Air Force (JANNAF) performance evaluation procedure. Use of the CICM in conjunction with the JANNAF procedure allows the analysis of engine systems using coaxial gas/liquid injection

A case study in multiple criteria decision support systems

Evaluation of strategic alternatives is an important task for strategic managers. This is a difficult task due to inherent complexities of the evaluation process and lack of structured information. The evaluation process must consider external opportunities and threats, and internal strengths and weaknesses. This paper presents a case study in multiple criteria decision support systems. The decision support system presented in this paper utilizes the model presented in the appendix along with several computer systems including EXPERT CHOICE and Spreadsheets to enhance and aid the decision maker\u27s- intuition in evaluating potential alternatives

Structured analysis and modeling of complex systems

The Aircrew Evaluation Sustained Operations Performance (AESOP) facility at Brooks AFB, Texas, combines the realism of an operational environment with the control of a research laboratory. In recent studies we collected extensive data from the Airborne Warning and Control Systems (AWACS) Weapons Directors subjected to high and low workload Defensive Counter Air Scenarios. A critical and complex task in this environment involves committing a friendly fighter against a hostile fighter. Structured Analysis and Design techniques and computer modeling systems were applied to this task as tools for analyzing subject performance and workload. This technology is being transferred to the Man-Systems Division of NASA Johnson Space Center for application to complex mission related tasks, such as manipulating the Shuttle grappler arm

An interactive learning environment in geographical information systems

The Unigis Learning Station is a computer‐based learning management tool for the Postgraduate Diploma in Geographical Information Systems by distance learning (correspondence). Unigis is an international network of universities co‐operating in the delivery of such courses. The students on Unigis courses are mature mid‐career professionals who study in addition to undertaking full time jobs. The Learning Station offers these students information about the course, resources for independent study, a structured set of exercises, assessments and feedback opportunities, and an integrated and easy way to interact with other course software. Following a brief introduction to the Unigis curriculum, this paper discusses the design of the Learning Station. The roles the Learning Station adopts are outlined, and the range of multimedia and communications tools used discussed. Evaluation of the Learning Station is presented and the issued raised by this provide useful lessons for other computer‐based learning management tools, and the adaptation of the Learning Station to other teaching and learning situations

An integrated approach to system design, reliability, and diagnosis

The requirement for ultradependability of computer systems in future avionics and space applications necessitates a top-down, integrated systems engineering approach for design, implementation, testing, and operation. The functional analyses of hardware and software systems must be combined by models that are flexible enough to represent their interactions and behavior. The information contained in these models must be accessible throughout all phases of the system life cycle in order to maintain consistency and accuracy in design and operational decisions. One approach being taken by researchers at Ames Research Center is the creation of an object-oriented environment that integrates information about system components required in the reliability evaluation with behavioral information useful for diagnostic algorithms. Procedures have been developed at Ames that perform reliability evaluations during design and failure diagnoses during system operation. These procedures utilize information from a central source, structured as object-oriented fault trees. Fault trees were selected because they are a flexible model widely used in aerospace applications and because they give a concise, structured representation of system behavior. The utility of this integrated environment for aerospace applications in light of our experiences during its development and use is described. The techniques for reliability evaluation and failure diagnosis are discussed, and current extensions of the environment and areas requiring further development are summarized

Methods of Evaluating 3D Perception Systems for Unstructured Autonomous Logistics

This study introduces methods of evaluating 3D perception systems, such as Time of Flight (ToF) systems, for automated logistics applications in unstructured environments. Here perception is defined as a system’s understanding of its environment and the Objects Of Interest (OOI) within that environment, through hardware consisting of cameras or depth sensors. Current computer guided machinery that rely on perception systems, such as an Autonomous Guided Vehicle (AGV), require structured environments that are specifically designed for such a machine. Unstructured environments include warehouses or manufacturing facilities that have not been tailor designed or structured specifically for the purpose of using a computer guided machine. In this study, two methods are proposed to assess 3D systems proposed for autonomous logistics in unstructured environments. The results of this study indicate that the methods presented here are suitable for future and comparative 3D perception and evaluation in this space