Advanced Workstation Research Articles

Visualization of Three-Dimensional Density Maps Reconstructed from Cryoelectron Micrographs of Viral Capsids

Full evaluation of three-dimensional density maps calculated from cryoelectron micrographs of complex supramolecular structures requires that the maps be sifted by a variety of complementary visualization techniques. We present here a primer for a number of such techniques in current widespread use, including surface rendering; serial sections; simulated motion; and real-time manipulation of tiled surfaces displayed on an advanced workstation. The principles on which these techniques operate are briefly reviewed, as are their advantages and limitations, with emphasis on the requirements for visual representation of viral capsid structures. These methods are illustrated in application to a density map of herpes simplex virus type 1 (HSV-1) capsid at 24 Å resolution, which reveals more detailed information than heretofore concerning the inner surface of the icosahedral capsid shell and the 150-Å-long channels that pass through each of the 162 capsomers.

A building block approach to the design and simulation of complex current-memory circuits

A building block approach to the design and simulation of complex current-memory circuits is described. Sampled-data techniques are used to simulate the operation of networks containing a great number of cells. The main building block is the current-memory cell itself, which has been carefully modeled including charge injection and noise. The proposed model has been compared to SPICE simulations on several small examples, and excellent agreement is obtained. Simulation of complex circuits is orders of magnitude faster than a full time-domain simulation with SPICE. The usefulness of the approach is demonstrated through the design and simulation of a current-memory based second order Σ — Δ modulator. The complete characterization of the signal-to-noise and distortion ratio can be achieved in about 4 hours of CPU time on an advanced workstation.

Beyond the Bounds of the Human Factors Tool Kit: Computer-Human Interface Design in a Complex System

To achieve the potential of human factors involvement in computer-human interface design, human factors engineers must transition from being isolated specialists to integrated components of the mainstream life-cycle development process. A fundamental obstacle to this transition has been the limitations associated with traditional human factors methods. The search for better methods has resulted in a recent evolution in the human factors tool kit. While this evolution has increased tool kit utility, it is not yet as robust as needed for the development of complex systems. For the past several years the human factor team at Loral Federal Systems Company has been the central focus of system design and development activities for the Tower Control Computer Complex (TCCC). The TCCC will replace most Federal Aviation Administration airport tower cab equipment with advanced workstations and software. At least five limitations have been encountered with the traditional human factors tool kit due to the complexity of the TCCC and the environment in which it will be used. This paper describes these limitations, and the alternatives that have been successfully employed to produce an operationally suitable computer-human interface as part of an integrated life-cycle effort. At the heart of these remedies were the use of a dedicated team of representative end-users and a variety of non-traditional design evaluation techniques, throughout the project life-cycle. Among these techniques was the evaluation of laboratory prototypes using a “hands-off” intellectual review process and electronically supported group-based evaluations.

Mission operations technology

In the last decade, the operation of a spacecraft after launch has emerged as a major component of the total cost of the mission. This trend is sustained by the increasing complexity, flexibility, and data gathering capability of the space assets and by their greater reliability and consequent longevity. The trend can, however, be moderated by the progressive transfer of selected functions from the ground to the spacecraft and by application, on the ground, of new technology. Advances in ground operations derive from the introduction in the mission operations environment of advanced microprocessor-based workstations in the class of a few million instructions per second and from the selective application of artificial intelligence technology. In the last few years a number of these applications have been developed, tested in operational settings and successfully demonstrated to users. Some are now being integrated in mission operations facilities. An analysis of mission operations indicates that the key areas are: concurrent control of multiple missions; automated/interactive production of command sequences of high integrity at low cost; automated monitoring of spacecraft health and automated aides for fault diagnosis; automated allocation of resources; automated processing of science data; and high-fidelity, high-speed spacecraft simulation. Examples of major advances in selected areas are described.

Compression of digitized map images

An efficient way to store and retrieve digitized chart images using a lossy vector quantization (VQ) compression technique is presented. A VQ codebook is located using the fast pairwise nearest neighbor (PNN) clustering algorithm. A k-d tree data structure is used for efficient image compression. Some unique features of this approach are that compressed files use a predictable amount of storage, and can be decompressed quickly for display on equipment ranging from portable personal computers to advanced graphics workstations. The method also applies to panchromatic and multispectral satellite imagery. In this application, digitized chart images with compression ratios of 24:1 exhibited good quality. In certain applications, even higher compression ratios are feasible.

Current Techniques for Real-Time Evaluation of Conditional Symmetric Instability

Abstract Banded cloudiness and precipitation are sometimes observed in convectively stable environments. These observations are often attributed to conditional symmetric instability (CSI). High-resolution operational instruments in the wind-profiler network and the WSR-88D radar network are beginning to provide real-time data that can enhance the evaluation of CSI conditions. These systems, combined with operational mesoscale models and the advanced meteorological computer workstation, are providing the opportunity to efficiently assess CSI on the meso-β scale (20–200 km) in real time. CSI theory is reviewed and techniques to apply CSI theory utilizing the new operational instrumentation are discussed. A case study is presented to illustrate current CSI evaluation techniques.

FUSING IMAGE SYNTHESIS AND COMPUTER VISION

Researchers at the Swiss Federal Institute of Technology in Lausanne have combined computer graphics and vision techniques in a new tool used to interpret scenes. The Model‐based Vision System (MBVS) proposes a vision system that uses CAD packages to take full advantage of advanced synthetic images and graphic workstation systems.

Formalization of teaching materials for a network‐based laboratory support system

AbstractAs the information in society becomes more complex, the importance of advanced education and lifelong learning in universities and corporations is increasing. Since the current situation in general education at universities, for example, is group instruction of a large number of students, instruction that responds to the differences in ability of each student is becoming difficult.To improve this situation, the trend of the falling price of computers in recent years has been accompanied by energetic research on laboratory support systems. Although when considering the presentation of a superior user interface, the development support and management of the vast amount of teaching materials that accompanies the diversification of the learning objectives, and the implementation of ample teaching support functions, earlier computer‐based systems seem to have functional limits.Therefore, the transition to network‐based laboratory support systems that use advanced workstations is demanded. However, in building this type of laboratory support system, the formalization of the teaching materials suited for use in a distributed environment is required, but this kind of research has not been performed in the past.This paper introduces a new framework for formalizing the structure of teaching materials to be used in distributed environments. In addition, its efficiency is discussed as the model used for teaching materials in the implementation of a network‐based laboratory support system, which is being designed and developed.

B-ISDN multimedia communication and collaboration platform using advanced video workstations to support cooperative work

A distributed real-time computer-supported cooperative work (CSCW) platform called the B-ISDN group teleworking system is described. The system combines the high-speed multimedia communication capability with advanced video integrated workstations. The aim of this system is to support ad hoc meetings and real-time collaborative work between small groups of people who are geographically distributed. The main features of the system are face-to-face communication and the capability for sharing and comanipulating shared multimedia information including video. The concept and architecture of the system are described. A prototype group teleworking system that uses B-ISDN multimedia workstations is also described. A mock remote medical consultation application for the system is presented. >

Surface Weather Analysis at the National Meteorological Center: Current Procedures and Future Plans

The preparation of surface weather analyses at the National Meteorological Center (NMC) is currently under review. The availability of advanced graphics workstations and consideration of revisions to conceptual models of cyclogenesis and frontal analysis present challenges and opportunities for improving surface analysis at NMC. In this paper, current procedures and surface analysis products are reviewed. The adaptation of workstation technology to one surface weather analysis product, the Daily Weather Maps, Weekly Series, is described and presented as a preliminary experiment for assessing the utility of performing surface analyses on interactive workstations. Finally, issues that will impact the future of surface analysis at NMC, such as workstation development, utilization of gridded datasets and their manipulation for improving objective analyses, possible revisions to frontal symbology, incorporation of mesoscale symbology, and changes to sea-level pressure computations, are discussed.

Anatomy of a new medium: Literary and pedagogic uses of advanced linguistic computer structures

The availability of advanced function workstations makes possible a new medium for the manipulation of language which changes in kind as well as in degree the pedagogic and literary potential of the computer. This article presents a structural/functional analysis of the kind of system that, though still unrealized, is becominig increasingly possible to build: an Advanced Language System that includes natural language processing, knowledge representation, discourse structure, and narrative structure. Communicative language learning and the creation of computer-based fiction are both served by the emergence of this medium. Advanced language systems may include: “ako” links, semantic networks, query, “script,” “analogy,” and character/belief structures. For language learning advanced language systems offer greater error correction and research opportunities and more flexibility in presenting communicative and cultural exercises. For the creation of art, they offer the possibility of creating “round” instead of “flat” characters and “dynamic” rather than static plots. Programs which “learn” offer the possibility of creating literary formulae and even interpretive “traditions” on the computer. Literary invention will always be the key to making such systems effective as art or as aids to communicative learning.

Integrating knowledge-based technology into computer aided ventilation systems

A knowledge-based decision support system for respirator treatment, the KUSIVAR system, has been designed in cooperation between hospital, university and industry. Changes in patient data from respirator and monitoring equipment trigger a computer program that generates advice to the staff concerning e.g. therapy modes and respirator settings using expert systems and process control technology. A prototype has been built on an advanced development workstation, the Unisys Explorer, using the software Knowledge Engineering Environment (KEE). The clinical version is implemented on an Intel 80396-based microcomputer connected on-line via a data-acquisition processor to the respirator. The decision support software is implemented as a module under the Microsoft Windows multitasking environment and communicates with modules for data acquisition, database handling and data presentation by means of message passing using the Windows Dynamic Data Exchange protocol. The modules present coherent user interfaces by conforming to Microsoft Windows standards. The knowledge base is being extensively validated by an expert group in the ICU and the system will be evaluated through animal experiments and clinical studies.

Strategies for scientific prototyping in Smalltalk

This paper describes the design of a scientific prototyping environment in Smalltalk and discusses implementation strategies to achieve high performance interactive modeling of computationally intensive physical problems. Classes for scientific visualization, including contour plotting and 3D surface representations which incorporate the model-view-controller paradigm are presented. Techniques for inclusion of user primitives written in C to support computationally intense methods are described in detail in their current implementation on advanced Smalltalk workstations (SUN4, Ardent Titan, Tektronix 4317).

Does the Medium Make a Difference? Two Studies of Writing with Pen and Paper and with Computers (Abstract Only)

This article reports two studies examining how the use of computer technology affects writers' processes and resulting written products. A partial replication of Gould's 1981 study, the first experiment compared the efficiency and quality of 15 experienced writers' persuasive letters written in three counter-balanced conditions: pen and paper, standard personal computer, and advanced workstation. Analyses of time to compose and length of the resulting letters showed that when composing with the advanced workstation, writers wrote for longer periods of time and composed longer letters than when composing with pen and paper. Rate of composition (words per minute) was similar in all three conditions. Scores for content quality, mechanics quality, and total quality were also collected and analyzed. Letters composed with the personal computer were poorer in content quality and total quality. There were no differences in mechanics quality. In the second experiment, 8 of the original 15 writers revised two of their letters in the medium with which they were composed. Think-aloud protocols collected while the writers revised were analyzed. When revising with pen and paper, writers planned more than when revising on-line, and they planned more before beginning their revisions. However, when revising in the computer conditions, writers reread their texts more and paid more attention to the medium than when revising on paper.

Does the Medium Make a Difference? Two Studies of Writing With Pen and Paper and With Computers

This article reports two studies examining how the use of computer technology affects writers' processes and resulting written products. The first experiment, a partial replication of Gould's (1981) study, compared the efficiency and quality of 15 experienced writers' persuasive letters written in three counterbalanced conditions: pen and paper, standard personal computer, and advanced workstation. Analyses of time to compose and length of the resulting letters showed that when composing with the advanced work-stations, writers wrote for longer periods of time and composed longer letters than when composing with pen and paper. Rate of composition (words per min) was similar in all three conditions. Scores for content quality, mechanics quality, and total quality were also collected and analyzed. Letters composed with the personal computer were poorer in content quality and total quality. There were no differences in mechanics quality. In the second experiment, 8 of the original 15 writers revised two of their letters in the medium with which they were composed. Think-aloud protocols collected while the writers revised their letters were collected and analyzed. When revising with pen and paper, writers planned more than when revising on-line; they also planned more before beginning their revisions. However, when revising in the computer conditions, writers reread their texts more and paid more attention to the medium than when revising on paper.

Designing a Workstation for Information Seekers

The goal of our research project is to explore the use of new technologies in providing more sophisticated delivery systems for information services in situations where the services of skilled reference librarians are not available. We are working on developing an advanced function workstation equipped with a CD-ROM jukebox of reference books and vocabulary control tools on laser dlsks with keyword access. The user interface will include an expert system to guide users in selecting the types of material best suited to their needs. It will also provide guidance in developing the best search strategy by mapping the terms selected by the users to the more controlled vocabularies of the data bases. Searches that are too broad and yield too much material will be narrowed. Conversely, searches that are too specific will be broadened. The system will also be designed to connect to a full service integrated library network also enabling the user to access the on-line card catalog, check circulation and do interli...

Advanced Workstation for the Design and Supervision of Industrial Control Systems

CAD software for control system is presented. For the practical use, the data processing of actual processes takes the important role. Parameter tuning and adaptation scheme for nonlinearity and historical change is mainly discussed. Simulation case study is useful for the analysis and design of actual process, because multivariable interaction and nonlinear behavior exist very commonly and those characteristics cannot be theoretically analysed.

Modelling the cityscape with geometry engines

This paper records an experiment in using an advanced colour graphics workstation, in conjunction with existing visualization software, to model the city centre of Glasgow. The ‘geometry engines’ of the workstation allow the user of the system to change the viewing parameters dynamically and thus to simulate a ‘walk-round’ or ‘fly-through’ quite large data sets. The workstation had video output and it is difficult to communicate the potential of this system in any other medium; hard copy is reproduced in the paper mainly to give the reader some impression of the scale at which it is now possible to work.

Advanced Technology in Foreign Language Instruction and Translation

The hardware available for computer-assisted language learning is rapidly improving. Software development continues to lag, and the empirical foundation for second language acquisition research is inadequate. A strategy for remedying these deficiencies is outlined. Networked microcomputers whose software for computer-assisted language learning generates logs of user activity for analysis of second language acquisition offer interesting possibilities both for practical applications and in research. With access to a national network of data, testing, and teaching materials, such local networks will support advanced workstations and software allowing more complex interactions with the learning environment.

Integration of satellite data with other data for nowcasting

The Program for Regional Observing and Forecasting Services (PROFS) operates its own Geostationary Operational Environmental Satellite (GOES) mode AA and mode A groundstations and generates both VISSR (Visible and Infrared Spin-Scan Radiometer) and VAS (VISSR Atmospheric Sounder) image products for its advanced meteorological workstation in real time. Derived VAS temperature soundings are received daily from the University of Wisconsin-Madison. PROFS has been improving its real-time workstation since 1981 and has used it to study mesoscale nowcasting. The workstation provides efficient access, display, and loop control of satellite products and other conventional and advanced meteorological data. Data are integrated by displaying products on standard map projections so that imagery and graphics can be combined at the workstation, by using data from a variety of sources to compute image products, and through machine analysis and modeling. The workstation's capabilities have been assessed during PROFS real-time nowcasting experiments. Nowcasts are made with the workstation, and chase teams track and observe severe weather to evaluate these nowcasts. Five-minute rapid scan visible imagery was found to be quite useful in conjunction with Doppler radar data for nowcasting. In contrast, 30-minute infrared (IR) and VAS data were beneficial for short-range forecasts. Loops of VAS water vapor imagery along with conventional IR imagery at national and regional scales showed the greatest overall utility of the satellite imagery studied. Processed sounding data showed some success depicting unstable regions prior to convection.