Orthorhombic Materials and Perfect Lenses

The potential of orthorhombic materials for perfect lenses is theoretically examined.     

Efficiency improvements in US office equipment: Expected policy impacts and uncertainties

We create a business as usual scenario for office equipment electricity use from industry forecasts of equipment sales, surveys of equipment densities by building type, measured data on wattage and usage by equipment type and projected lifetimes for equipment. We then calculate electricity used by building type and equipment type for Energy Star and advanced scenarios and explore the sensitivity of these results to variations in key input parameters. According to our analysis, the Energy Star programme will save the US almost US$1 billion annually starting in the year 2000, with minimal expenditure of public funds.     

APPLICATIONS MAINTENANCE OUTSOURCING An Alternative to Total Outsourcing

Appropriately structured arrangements for systems maintenance outsourcing can yield significant benefits to many organizations. This article reviews methods for assessing potential maintenance outsourcing suppliers, for defining service criteria, and for evaluating contract terms.     

Cynicism and Social Trust in the New Media Environment

This article, with minor modifications, was the author's presidential speech to the International Communication Association conference, May 2001. It summarizes trends in social trust, trust in government, media, and other social institutions and evaluates the news and entertainment media's roles in these trends. Alternatives to causal accounts are proposed, including variations on genetic or "memetic" forms of explanation for media influences on macrosocial trends.     

Opposed jet flames of lean or rich premixed propane-air reactants versus hot products

Several opposed jet flames, produced by a lean H₂-air jet opposing a rich or lean C₃H₈-air jet, are investigated. Spontaneous Raman spectroscopy is used for major species concentration and temperature measurements along the opposed jet centerline. The hot products of the H₂-air flame simulate the burnt gases of strong-burning near-stoichiometric reactants as they impinge upon a weak-burning lean or rich hydrocarbon-fueled reactant mix, a situation encountered in stratified charge operation of direct injection spark ignition engines. In addition the H₂-air flame hot products facilitate experimental data interpretation through the absence of carbon-bearing species. Good agreement between numerical and experimental data are obtained for a rich (equivalence ratio, φ = 1.25) C₃H₈-air jet versus a lean (φ = 0.4) H₂-air jet. Two lean C₃H₈-air jets (φ = 0.64 or 0.60), versus the φ = 0.4 H₂-air jet, are also investigated. For both of these flames, the amount of CO₂ production strongly depends upon φ, with the φ = 0.64 flame having a peak CO₂ mole fraction an order of magnitude higher than for the φ = 0.60 flame, and the C₃H₈ flames burning either as a normal flame (high CO₂) or as a “negative flame speed” flame producing little CO₂ and then only through diffusion of C₃H₈ into the hot products jet. The numerically predicted and experimental CO₂ profiles agree well for the positive flame speed flame, but the large discrepancy between predicted and measured peak CO₂ in the negative flame speed flame suggests modeling improvements are needed for this type of flame.     

Evaluation of ProKappa

ProKappa is an expert system tool kit developed by IntelliCorp in C using X-Windows for graphical interface. The SUN 3 or 4 version costs $9995/£7000 and $2595/£1800 for the interactive C environment.
This review covers ProKappa version 1.1, installed on a colour SUN SPARC Station 1 with the minimum recommended values of 12 Mb of memory and 30 Mb of swap space.
IntelliCorp can be contacted in the USA at 1975 El Camino Real West, Mountain View, CA 94040-2216 (+1 (415) 965-5500) and in the UK at 10 Jewry Street, Winchester, Hampshire SO23 8RZ (+44 (0)962 735348).     

Optimal algorithms for adjacent side routing

We consider the switchbox routing problem of two-terminal nets in the case when all thek nets lie on two adjacent sides of the rectangle. Our routing model is the standard two-layer model. We develop an optimal algorithm that routes all the nets whenever a routing exists. The routing obtained uses the fewest possible number of vias. A more general version of this problem (adjacent staircase) is also optimally solved.This research was supported in part by NSA Contract No. MDA-904-85H-0015, NSF Grant No. DCR-86-00378, and by NSF Engineering Research Centers Program NSFD CDR 88003012.     

Atmospheric corrosion of reference metals in Antarctic sites

This paper presents the results obtained at three Antarctic test sites participating in the “Ibero-American Map of Atmospheric Corrosiveness” (MICAT), a project on atmospheric corrosion carried out during the period 1988–1994 at some 70 sites distributed across 12 countries of the Latin-American region, Spain and Portugal. The three Antarctic sites are located near the coastline.The singular climatic characteristics of Antarctic regions are related with the purity of the air, the absence of rainfall and the formation of ice on the metallic surface during an important part of the exposure time. However, electrochemical activity is possible below ice layers. This situation affects the structure and morphology of corrosion product films and the resulting corrosion rates of metallic surfaces.     

Parallel path consistency

Filtering algorithms are well accepted as a means of speeding up the solution of the consistent labeling problem (CLP). Despite the fact that path consistency does a better job of filtering than arc consistency, AC is still the preferred technique because it has a much lower time complexity. We are implementing parallel path consistency algorithms on multiprocessors and comparing their performance to the best sequential and parallel arc consistency algorithms.^(1,2) (See also work by Kerethoet al. ⁽³⁾ and Kasif⁽⁴⁾) Preliminary work has shown linear performance increases for parallelized path consistency and also shown that in many cases performance is significantly better than the theoretical worst case. These two results lead us to believe that parallel path consistency may be a superior filtering technique. Finally, we have implemented path consistency as an outer product computation and have obtained good results (e.g., linear speedup on a 64K-node Connection Machine 2).