Edwin H. Rogers

The trials of wafer-scale integration: Although major technical problems have been overcome since WSI was first tried in the 1960s, commercial companies can't yet make it fly

The advantages and problems of wafer-scale integration (WSI) are described. The advantages of semiconductor integrated circuits are high reliability, minimized interconnections, and decreased signal delay. The problems concern heat removal, signal quality, and the need for discretionary wiring. Finally, some recent approaches to WSI fabrication are discussed.

A numerical study of the formation and propagation of traveling bands of chemotactic bacteria

Abstract A model for chemotaxis in a bacteria-substrate mixture, previously given by Keller & Segel (1971), is studied. Initial conditions representing experiments of Adler are chosen. These correspond to an initial inoculum of bacteria at one end of the tube which is initially filled with a uniformly distributed chemical attractant. The partial differential equations of the model and the initial conditions are analyzed numerically by a Crank-Nicolson method. Non-uniform traveling band solutions are found for various values of the parameters. The effect of these parameters on the solution is discussed. The separation process is analyzed wherein some of the initial inoculum is left near the origin and the rest breaks away to form the traveling band. Comparison is made to the analytic results of Keller & Segel and to the experimental results of Adler. The effects of initial conditions and of the form of the coefficient functions are studied and compared to experimental data.

Going Public: Collaborative Systems Design for Multidisciplinary Conversations

The driving idea behind our work has been the concept of going public with the goal of supporting the emerging work practices of multidisciplinary teams. In this chapter, we outline the theoretical basis for going public, describe the underlying architecture of a public collaborative system and introduce two embodiments, the Design Conference RoomTM and the Collaborative ClassroomTM. The underlying architecture of a public collaborative system, overlaid with lines of view, sight, and control, provides system-sharing functionality via the Reconfigurable Collaboration NetworkTM, supporting fully collaborative conversations, with their trajectory of work processes from private, to public, and back again. Innovations are described in the disciplinary domains of architecture, computer science, and communication.

Disciplining Discourse Discourse Practice in the Affiliated Professions of Software Engineering Design

The authors report an investigation of the discourse practices of the “affiliated professions” of software engineering design. Lists of design issues generated by students in computer science and technical communication were compared to lists produced by experts affiliated with software engineering and by students entering an unaffiliated profession. The results suggest that (a) the affiliated experts addressed a more balanced set of issues, (b) the students in computer science looked more like the affiliated experts in their attention to technical issues and more like the unaffiliated students in their attention to human issues, and (c) the students in technical communication looked more like the affiliated experts in their attention to the human issues and more like the unaffiliated students in their attention to the technical issues. The results are discussed in terms of a landscape of highly clustered, fractured, and stratified affiliated professions over which students travel during their educational and professional careers.

An Isma Lee Router Accelerator

By concentrating on application-specific behavior, extremely simple and fast state machines can be designed and replicated into arrays that fit in one or two chips. Called an iterative state machine array, this architecture can increase speed by a factor of 1000 over the speed possible with traditional software design automation tools. Because the basic ISMA cells are so simple, designers can use special-purpose hardware economically, instead of relying on software for larger, slower general-purpose systems. When applied to two-layer Lee routing, we estimate that the ISMA can route 1000 two-point nets of length 2500¿ over a (2048¿)2 surface in under half a minute. A generalpurpose purpose von Neumann system could take hours, in comparison.

Petri nets in the evaluation of collaborative systems

Petri nets were conceived by Carl Petri as a mathematical means of describing activities, resources, and states of a system. They have been used to model, analyze and evaluate control system behavior. They have also been used in software engineering. More recently, Petri nets have been used to describe the behavior of computer supported workflows and extended to apply to protocols appearing in collaborative systems comprised of human participants and multiple resources including oral communication and electronic interaction. In every case, the Petri nets are modeling protocols. These interaction management rules include interfaces among real machines, virtual machines and humans. The paper describes Petri net modeling in the context of a study of team interactions in a mixed media lab setting. Analysis of extensive records of team speech and use of computer tools available to each member, led to empirically derived Petri nets which capture actual behavior, including the evolution of team preferred protocols. Among these were synergies between member communications via distinct media. Specifically, throughout the study, the participants, unbeknownst to them, were learning to use oral communication to change the protocols which were assigned for the electronic medium. The change in behavior was so subtle that only through evaluating the transcripts and creating Petri net models to capture observed behavior was this made clear.

Architectural yield analysis of random defects in wafer scale integration

Wafer-scale integration yield concepts are examined. New models of yield are defined and their utility is shown by analyzing the architectural and topological yield of some regular structures. Yield concepts are reviewed, the idea of architectural yield is defined, a mathematical framework for studying such yield is established, and assumptions are discussed. These are applied to architectural goals involving binary tree structures.<<ETX>>

A collaborative learning environment for intellectual teamwork across the curriculum

While the solitary genius inventor remains a romantic icon, the modern workplace is dominated by collaborative activity. As products and services grow in complexity, collaborative design is becoming increasingly multidisciplinary and conducted by large teams of specialists (often including clients or client surrogates). Consequently, universities must prepare students for collaborative work. This paper describes an experimental facility in which new pedagogical opportunities have been created for teaching teamwork in each discipline and across disciplines.

CAMELOT: technology focused testing of CSCW applications

In this paper we describe CAMELOT, a technology-focused methodology for testing computer supported cooperative work (CSCW) software. Unlike previous CSCW evaluation techniques examining social issues, CAMELOT is intended for use by application developers, user interface specialists, performance engineers, and quality assurance personnel. The method divides an evaluation into two stages: single user and multi-user. The single user stage is subdivided into general computing and human-computer interaction testing. The multi-user stage is decomposed into distributed computing and human-human interaction testing. The methodology provides a detailed, codified, checklist of testing techniques for each stage. CAMELOT was applied to a conventionally tested, mature CSCW application and uncovered over two dozen problems.

NoteMaker: a hyper-design notebook to support informal communication in the engineering design process

The author describes NoteMaker, a prototype environment that supports interactive design conceptualization, planning, recording, and communication among collaborators. Written in HyperCard 2.0, NoteMaker prototype environments consist of a folder containing note stacks shepherded by a manager stack. NoteMaker is notable among hyper-text applications because it creates an environment in which users read and write their own texts rather than simply reading texts created and prestructured by others. By providing a mix of automatic and user-constructed facilities and multiple means of navigation, NoteMaker has been designed to ameliorate the danger of hyper-text environments to lose the user in a morass of information and unmanageable pathways. NoteMaker will enable users to access and amend notes and sketches related to their work and studies at any time-in the office, in meetings, on site visits, while travelling, and working alone almost anywhere.<<ETX>>