A Microprocessor-Based Synchronization Scheme for Digitally Controlled Three-Phase Thyristor Power Converters

This paper presents a microprocessor-based scheme that generates the necessary synchronization logical signals for three-phase static power converter control systems. The problem of detecting the phase-to-phase voltage zero-crossing in presence of noise generated by thyristor commutations in constant and in variable frequency supplies is discussed, and a microcomputer software solution is proposed.     

Dental accidents in relation to general anesthesia. Experience of mutual medical insurance group

This article reviewed retrospectively 511 cases of dental damage reported to the French group for medical insurances from 1990 to 1995, and representing 40% of all accidents related to anaesthesia. The mean incidence rate was 9.5 accidents/100 anaesthetists/year and tended to decrease over time. The part of cases qualified as being linked to a fault was high and mainly due to the lack of dental examination and of informed consent during the preanaesthetic assessment. Although the mean cost of a dental accident is low compared with other anaesthetic accidents, the global cost is substantial considering their high incidence.     

Management of waste from uranium mining and milling in Australia

Australia has a long history of uranium mining. Most of the early production came from Rum Jungle in the Northern Territory and Mary Kathleen in Queensland. The second generation of uranium mines (Ranger, Nabarlek and Olympic Dam) came on line in the 1970s and 1980s at a time of increased environmental awareness and public scrutiny. The waste management practices at these mines are in accordance with best practicable technology for the uranium mining industry. This paper describes Australia's experience in managing the front end of the fuel cycle; uranium mining and ore processing.     

Editorial

Higher-Order and Symbolic Computation -     

Specialized Knowledge,Professionalism and the Discipline of Architecture

In preparation of the JAE Jubilee issue many invitations were made to respond to the paragraph printed below. Because of a highly condensed schedule in the production of this special issue, the cut-off date for receipt of articles had to be moved up and several individuals, whose invited responses were in the final stages of preparation or even in transit to JAE, could not be included in that issue. This is regrettable; however, during the upcoming year we will be printing those articles and again invite our readership to respond and discuss those issues put forward in the Jubilee statement. —Ed.     

NAVAL SECURITY GROUP COMMAND DISPLAY

Presented here is information concerning the move of the U. S. Navy's Wenger Cryptologic Museum from 3801 Nebraska Avenue NW, Washington DC, to Corry Station, Pensacola FL. The move was required when the Naval Security Group moved to Fort Meade, Maryland several years ago. The move has been completed and the new facility is now open to the public. It has a new name; it is now called the Naval Security Group Command Display.     

Remote Estimation of Nutrients for a Drinking Water Source Through Adaptive Modeling

Morse Reservoir, a major water supply for the Indianapolis metropolitan area, IN, USA, experiences nuisance cyanobacterial blooms due to agricultural and point source nutrient loadings. Hyperspectral remote sensing data from both in situ and airborne AISA measurements were applied to an adaptive model based on Genetic Algorithms-Partial Least Squares (GA-PLS) by relating the spectral signal with total nitrogen (TN) and phosphorus (TP) concentrations. Results indicate that GA-PLS relating in situ spectral reflectance to the nutrients yielded high coefficients of determination (TN: R ²?=?0.88; TP: R ²?=?0.91) between measured and estimated TN (RMSE?=?0.07 mg/L; Range: 0.6–1.88 mg/L), and TP (RMSE?=?0.017; Range: 0.023–0.314 mg/L). The GA-PLS model also yielded high performance with AISA imaging data, showing close correlation between measured and estimated values (TN: RMSE?=?0.11 mg/L; TP: RMSE?=?0.02 mg/L). An analysis of in situ data indicated that TN and TP were highly correlated with chlorophyll-a and suspended matter in the water column, setting a basis for remotely sensed estimates of TN and TP. Spatial correlation of TN, TP with chlorophyll-a and suspended matters further confirmed that remote quantification of nutrients for inland waters is based on the strong association of optically active constituents with nutrients. Based on these results, in situ and airborne hyperspectral remote sensors can provide both quantitative and qualitative information on the distribution and concentration of nutrients in Morse Reservoir. Our modeling approach combined with hyperspectral remote sensing is applicable to other productive waters, where algal blooms are triggered by nutrients.