Victor L. Wallace

The art of natural graphic man—Machine conversation

The design of interactive graphic systems whose aim is good symbiosis between man and machine involves numerous factors. Many of those factors can be judged from the perspective of natural spoken conversation between two people. Guiding rules and principles for design of such systems are presented as a framework for a survey of design techniques for man-machine conversation. Attention is especially focused on ideas of action syntax structuring, logical equivalences among action devices, and avoidance of psychological blocks to communication.

The art of natural graphic man-machine conversation

The design of interactive graphic systems whose aim is good symbiosis between man and machine involves numerous factors. Many of those factors can be judged from the perspective of natural spoken conversation between two people.Guiding rules and principles for design of such systems are presented as a framework for a survey of design techniques for man-machine conversation. Attention is especially focused on ideas of action syntax structuring, logical equivalences among action devices, and avoidance of psychological blocks to communication.

A performance model of space-division ATM switches with input and output queueing

An analytic model for the performance evaluation of space-division asynchronous transfer mode (ATM) switches is presented. This model assumes that the switch has a fixed capacity of m, where 1/spl les/m/spl les/N (N is the number of trunks). Other important parameters include arrival rate and buffer sizes. Numerical solutions for the maximum throughput, cell delay, and cell loss probability are given with simulation being utilized in order to validate the analytic model. For independent and identical Bernoulli arrivals, the study shows that the contention processes can be modeled as discrete M/D/m (FIFO or Random) queues, while input queues can be modeled by Geom/G/1 queues, and the output queues are G/sup [X]//D/1 queues. A closed-form approximation for cell delay when m>2 is given. The result shows that the performance of switches with a small capacity can approach that of output queueing. The model and result can be used for switch design analysis and higher layer performance models.

Network traffic model using GIPP and GIBP

In telecommunication networks, the correlated nature of teletraffic patterns can have significant impact on queuing measures such as queue length, blocking and delay. There is, however, not yet a good general analytical description which can easily incorporate the correlation effect of the traffic, while at the same time maintaining the ease of modeling. The authors have shown elsewhere, that the covariance structures of the generalized Interrupted Poisson Process (GIPP) and the generalized Interrupted Bernoulli Process (GIBP) have an invariance property which makes them reasonably general, yet algebraically manageable, models for representing correlated network traffic. The GIPP and GIBP have a surprisingly rich sets of parameters, yet these invariance properties enable us to easily incorporate the covariance function as well as the interarrival time distribution into the model to better matchobservations. In this paper, we show an application of GIPP and GIBP for matching an analytical model to observed or experimental data.

Multiple feedback queue as a model of general purpose multiprocessor systems

In this paper an approach toward modeling a multi-programmed general purpose multiprocessor system which links concurrent job structure with processor system structure is proposed. This new approach preserves the property of task precedence relations associated with a family of concurrent processes and yet provides a simple way to evaluate performance of a job and the system.

Investigations into a command and response language interface

Access to the variety of resources offered by computer networks is often complicated by the diversity of interfaces and protocols encountered. To overcome this diversity, a command-and-response language interface to a network of heterogeneous systems is proposed. A brief account of previous work in command languages and system interfaces motivates the study of a prototype of the proposed interface. The design, implementation, and lessons learned through the successful realization of the prototype are presented.<<ETX>>

Cost trade-offs in hardware support (Panel Discussion)

A serious problem facing Computer Science educators is deciding what type of computer resource(s) needs to exist in order to serve Computer Science students. Should these resources include Time-Sharing, micro-processors, one large dedicated computer, and so forth? What are colleges and universities doing to attack this question? A panel of faculty from several colleges and universities of Computer Science education will present views and insights. There will be time for questions and answers from the audience.