A multiarchitecture parallel-processing development environment

A description is given of the hardware and software of a multiprocessor test bed - the second generation Hypercluster system. The Hypercluster architecture consists of a standard hypercube distributed-memory topology, with multiprocessor shared-memory nodes. By using standard, off-the-shelf hardware, the system can be upgraded to use rapidly improving computer technology. The Hypercluster's multiarchitecture nature makes it suitable for researching parallel algorithms in computational field simulation applications (e.g., computational fluid dynamics). The dedicated test-bed environment of the Hypercluster and its custom-built software allows experiments with various parallel-processing concepts such as message passing algorithms, debugging tools, and computational 'steering'. Such research would be difficult, if not impossible, to achieve on shared, commercial systems

Telecommunications productivity, catch-up and innovation

This study examines telecommunications productivity, technological catch-up and innovation in 74 countries for the period 1991-1995. A summary of partial productivity indicators is presented, and total factor productivity (TFP) growth is calculated using the Malmquist productivity change index. Decomposition of the Malmquist index provides preliminary evidence that developing countries can enhance productivity through catch-up. An econometric model is estimated that relates innovation to market size and two measures of market structure, viz., market concentration and private ownership. Model estimates support the Schumpeterian hypothesis that market size is conducive to innovation. However, the hypothesis that concentration (the dominant carrier's share of international message telephone service (IMTS) traffic) is positively related to innovation is rejected. Finally, the model suggests that increased private ownership of the dominant local-exchange carrier can enhance innovation.Catch-up; innovation; market structure; productivity; telecommunications

Market structure, competition, and pricing in United States international telephone service markets

Abstract—Several national governments argue international telephone prices are high because of asymmetric competition and inefficiencies in the accounting arrangements that govern the telecommunications services trade. This paper develops a model of U.S. international telephone pricing that allows for the accounting rate system and contains market-structure variables for both the U.S. and foreign ends of bilateral markets. Model estimation is on 39 bilateral telephone markets from 1991 through 1994. Parameter estimates reveal that settlement rates, market concentration, competition at either end of the bilateral market, and ownership are significant determinants of prices. These findings support initiatives promoting accounting-rate reductions and increased competition.United States international telephone service markets

Distributed earth model/orbiter simulation

Distributed Earth Model/Orbiter Simulation (DEMOS) is a network based application developed for the UNIX environment that visually monitors or simulates the Earth and any number of orbiting vehicles. Its purpose is to provide Mission Control Center (MCC) flight controllers with a visually accurate three dimensional (3D) model of the Earth, Sun, Moon and orbiters, driven by real time or simulated data. The project incorporates a graphical user interface, 3D modelling employing state-of-the art hardware, and simulation of orbital mechanics in a networked/distributed environment. The user interface is based on the X Window System and the X Ray toolbox. The 3D modelling utilizes the Programmer's Hierarchical Interactive Graphics System (PHIGS) standard and Raster Technologies hardware for rendering/display performance. The simulation of orbiting vehicles uses two methods of vector propagation implemented with standard UNIX/C for portability. Each part is a distinct process that can run on separate nodes of a network, exploiting each node's unique hardware capabilities. The client/server communication architecture of the application can be reused for a variety of distributed applications

Some economic and social aspects of residential internet use in Australia

This study constructs a profile of the representative Australian residential Internet user from data obtained from a web-based survey. Survey data indicate the representative user is male, 20 to 40 years of age, highly educated, uses the Internet 8 hrs per week for e-mail and FTP, and has a monthly bill of AUD32. Anordered-logit model relates Internet use to price, sociodemographic and connection capacity variables. Model estimates show the probability of higher Internet use is greater for middle-income households, but declines with age of the user. Policy may be required to enhance access to lower-income groups, and to inform the elderly of the potential capabilities of the new technology. Further, model estimates suggest that Australian Internet subscribers prefer flat-rate pricing (or a combination of flat-rate and usagesensitive pricing) over usage-sensitive pricing schemes. This result is consistent with Australian consumer attitudes toward local telephone and mobile cellular pricing.Residential internet use in Australia, economic and social aspects

CEE telecommunications investment and economic growth

The antiquated state of the telecommunications network in the transitional economies of Central and Eastern Europe has been identified by the OECD (1993) and the ITU (1994) as a significant impediment to regional productivity, international competitiveness and trade performance. This situation suggests that the upgrading and extension of the telecommunications network should be a priority objective for policy-makers in order to facilitate growth. This paper empirically examines the relationship between gross fixed investment, telecommunications infrastructure investment and economic growth for a sample of transitional economies in Central and Eastern Europe. In particular, the paper focuses on empirically determining the direction of influence, and timing, between investment and growth.Economies in transition; Investment and growth; Telecommunications infrastructure

A Variational Assimilation Method for Satellite and Conventional Data: a Revised Basic Model 2B

A variational objective analysis technique that modifies observations of temperature, height, and wind on the cyclone scale to satisfy the five 'primitive' model forecast equations is presented. This analysis method overcomes all of the problems that hindered previous versions, such as over-determination, time consistency, solution method, and constraint decoupling. A preliminary evaluation of the method shows that it converges rapidly, the divergent part of the wind is strongly coupled in the solution, fields of height and temperature are well-preserved, and derivative quantities such as vorticity and divergence are improved. Problem areas are systematic increases in the horizontal velocity components, and large magnitudes of the local tendencies of the horizontal velocity components. The preliminary evaluation makes note of these problems but detailed evaluations required to determine the origin of these problems await future research

Broadband delivered entertainment services: forecasting Australian subscription intentions

This study estimates a nested multinomial logit (NMNL) model of broadband delivered entertainment service subscription that allows for the impact of an installation fee and rental price, service attributes and household demographic variables on subscription. The model is estimated on stated-preference data obtained from an Australia-wide survey of capital cities and provincial centres. Nested multinomial logit model estimates are used to provide forecasts that suggest 65 per cent of separate residences passed are likely to subscribe at 2000. This percentage translates into 1237 744 subscriber.Broadband entertainment services; forecasting Australian subscription demand