March 1983 - Vol. 26 No. 3
Features
From Washington: The robot revolution: an interview with James Albus
There is growing awareness among U.S. manufacturers that time is running short to reorganize production processes and begin investment programs for new technology. Sales of accessories—robots, computer controls, and materials-handling systems—are expected to climb to $30 billion world-wide by 1996, compared with the 1982 total of $4 billion.* There is also much discussion about the feasibility of Japan's plans for a fifth generation of computers the danger of their outstripping us, and, in general, what the advent of robotics will do to the quality of life. Do you see the pervasive use of robots as a practical reality?
Remote office work: changing work patterns in space and time
Remote work refers to organizational work that is performed outside of the normal organizational confines of space and time. The term telecommuting refers to the substitution of communications capabilities for travel to a central work location. Office automation technology permits many office workers to be potential telecommuters in that their work can be performed remotely with computer and communications support. This paper examines some behavioral, organizational, and social issues surrounding remote work, particularly work at home.
An exploratory study was conducted of 32 organizational employees who were working at home. Important characteristics of jobs that can be performed at home were: minimum physical requirements, individual control over work pace, defined deliverables, a need for concentration, and a relatively low need for communication. The individuals who worked at home successfully were found to be highly self-motivated and self-disciplined and to have skills which provided them with bargaining power. They also made the arrangement either because of family requirements or because they preferred few social contacts beyond family.
Comparing two microcomputer operating systems: CP/M amd HDOS
Two moderate operating systems are compared, with the intent to demonstrate how each may satisfy the needs of a different set of users. The clear superiority of either systems does not emerge, but rather a difference in “design philosophy.” A method for comparing other similar systems is demonstrated.
On the modeling of parallel access to shared data
A model is constructed of a database that can be accessed and modified concurrently by a number of users, and an approximate solution is presented. The resource allocation policies considered involve dynamic acquisition of entities and locking; deadlock is avoided by limiting the number of consecutive attempts to acquire a particular entity. The accuracy of the approximation is evaluated by simulations. Several generalizations aimed at improving the practicality of the model are described.
A tree convolution algorithm for the solution of queueing networks
A new algorithm called the tree convolution algorithm, for the computation of normalization constants and performance measures of product-form queueing networks, is presented. Compared to existing algorithms, the algorithm is very efficient in the solution of networks with many service centers and many sparse routing chains. (A network is said to have sparse routing chains if the chains visit, on the average, only a small fraction of all centers in the network.) In such a network, substantial time and space savings can be achieved by exploiting the network's routing information. The time and space reductions are made possible by two features of the algorithm: (1) the sequence of array convolutions to compute a normalization constant is determined according to the traversal of a tree; (2) the convolutions are performed between arrays that are smaller than arrays used by existing algorithms. The routing information of a given network is used to configure the tree to reduce the algorithm's time and space requirements; some effective heuristics for optimization are described. An exact solution of a communication network model with 64 queues and 32 routing chains is illustrated.
Speeding up an overrelaxation method of division in Radix-2n machine
For normalized floating point division, digital computers can take advantage of a division process that uses an iterative multiplying operation instead of repeated subtractions. An improvement of this division process by using accelerating constants in the overrelaxation has previously been proposed. Multiplication by a chosen accelerating constant accelerates the process of generating accurate digits of a quotient in division. We propose a further improvement by generalizing the accelerating constants in the overrelaxation method. Two benefits resulting from this improvement promise to yield faster division in digital computers.
