Detection Probability Estimation of Directional Antennas and Omni-Directional Antennas

This paper studies the problem of detection of directional antennas and omni-directional antennas by hostile detection systems. We present a model for calculating the probability of detecting a transmitter at arbitrary location around the transmitter. Our study shows that, if a directional antenna employs the same transmit power as an omni-directional antenna, the directional antenna can not decrease the probability of being detected. In some scenarios, a directional antenna is more likely to be detected than an omni-directional antenna. However, if a directional antenna provides the same Effective Isotropic Radiated Power in the direction of the receiver as an omni-directional antenna, the transmit power needed by a directional antenna to send data is much less than that of an omni-directional antenna. In this scenario, the probability of detecting a directional antenna is reduced by over 90%. This reveals that directional antennas can be used to build a secure path to send data at low probability of being detected by adversaries.     

The cost of a package plant membrane bioreactor

The capital and operating costs associated with a small package plant MBR for small-scale domestic duty has been appraised based on a medium-strength municipal wastewater. The three main membrane configurations were considered, these being multi-tube, hollow fibre and flat sheet, with the most appropriate plant design chosen for each configuration. The analysis proceeded via a consideration of the estimated amortised capital costs of the plant individual components and their installation, coupled with operating costs based largely on energy demand and residuals management. Energy demand was calculated from aeration and pumping costs, with aeration based on a combination of empirical relationships for membrane aeration and mass balance, and the modified Activated Sludge Model version 2 used for estimating tank size and sludge generation. Results indicate that it is possible to produce a single household MBR at a capital cost similar to the current market cost for package treatment plants. Desludging and maintenance of these plants is similar but power requirements for an MBR are around 4 times that associated with more conventional package plants. Economies of scale exist from 6-20 p.e. plants but above 20 p.e. there is little cost difference per head, due to the design assumptions made. CAPEX and OPEX are to some extent interchangeable; reductions in CAPEX are associated with an increase in OPEX and vice versa. Whilst costs are high, the market for package MBRs is significantly influenced by the recycling potential of the effluent produced.     

Rapid and accurate reverse engineering of geometry based on a multi-sensor system

The reduction of the lead time in measurement and reverse engineering, and the increased requirements in terms of accuracy and flexibility, have resulted in a great deal of research effort aimed at developing and implementing multi-sensor systems. This paper describes an effective competitive approach for using a tactile probe to compensate the data from a laser line scanner to perform accurate reverse engineering of geometric features. With the data acquired using laser scanning, intelligent feature recognition and segmentation algorithms can be exploited to extract the global surface information of the object. The tactile probe is used to re-measure the geometric features with a small number of sampling points and the obtained information can be subsequently used to compensate the point data patches which are measured by laser scanning system. Then, the compensated point data can be exploited for accurate reverse engineering of a CAD model. The limitations of each measurement system are compensated by the other. Experimental results on three parts validate the rapidity and accuracy of this multi-sensor data fusion approach.     

Strokes in the elderly - higher acute and 3-month mortality - an explanation

Bardet-Biedl syndrome (BBS) is a rare, autosomal recessive disease characterized by retinal dystrophy, renal structural abnormalities, obesity, dysmorphic extremities, and hypogenitalism in males. BBS is genetically heterogeneous with four known loci: BBS1 (11q), BBS2 (16q), BBS3 (3p), and BBS4 (15q). The prevalence of BBS in Newfoundland is approximately 10-fold greater than in Switzerland (1:160,000) and similar to the prevalence among the Bedouin of Kuwait (1:13,500). A population-based genetic survey was performed on 17 BBS families from the island portion of the province of Newfoundland, a comparatively isolated region of Canada. The families in the study had a total of 36 well-documented, affected individuals with 12 families having 2 or more affected individuals. Linkage at each of the four known loci was tested with two-point linkage and haplotype analysis. Three of the 17 kindreds showed linkage to 11q, 1 to 16q, and 1 to 3p. The latter is the first BBS3 family identified in a population of northern European descent. Six families remain undetermined because of poor pedigree structure or inconclusive haplotype analyses. Six families were excluded from all four known BBS loci, indicating that there is at least a fifth BBS locus (BBS5).     

Source Apportionment of Individual Carbonaceous Particles Using 14C and Laser Microprobe Mass Spectrometry

An exploratory study of laser microprobe mass spectra of individual atmospheric soot particles has been made in search of a potential combustion source tracer index. A tentative “cluster ratio index” (CRI = C₄ ^?/C₂ ^?) has been found and compared with bulk measurements of ¹⁴C in a set of ambient samples exhibiting varying impacts from woodburning and motor vehicle exhaust. A CRI-¹⁴C calibration curve resulted, and it led to the conclusion that, at the present level of precision, three particles (or agglomerates) of micrometer size or about 3 pg of carbon would be required for discrimination between the two pure sources. Mixture samples, such as those reported here, would require about 40 times as much. Classification of small set of individual particles from the mixed source ambient samples, suggests preservation of carbonaceous source identity at the single particle level.     

Single Soybean Seed NMR Calibration for Oil Measurement Using Commercial Cooking Oils

Development of high oil soybeans would reduce the cost of soybean oil production for biodiesel or edible oil applications. An accurate determination of soybean seed oil concentration is essential especially when developing superior cultivars with increased seed oil content. The objective of this study was to develop an oil measurement method for single seeds using NMR spectrometry. An NMR spectrometer was calibrated using commercial cooking oil. Fifteen cultivars of known mean oil content were used to evaluate the calibration curves. The calibration curves developed had a correlation coefficient of 0.99. It was found that soybean and corn oil gave identical results over the calibrated interval.     

Bidirectional starting of a symmetrical two-phase switchedreluctance machine

The mechanical and electrical properties of the two-phase 4/2 switched reluctance machine make it suitable for high-speed operation. Its adoption in such applications has been hindered by a perceived starting problem especially if starting in both directions is required. A starting technique is proposed which exploits the natural magnetic asymmetry in the symmetrical machine geometry and provides for bidirectional torque production at start-up. The approach utilizes mutual coupling in the machine, an effect not previously identified for starting. The technique requires no modifications to either stator or rotor poles, and is suitable for fan applications which require only low starting torques. The starting technique is described and tested with nonoriented silicon steel and GOSS rotors, and starting torque from machine experimentally determined     

Automatic tension adjustment for interpolatory splines

The authors deal with anomalous oscillations often exhibited by cubic spline interpolating curves. These oscillations, which are not suggested by the data, can be treated with a shaping parameter called tension, which is introduced by generalizing the cubic spline formation in some fashion. The authors consider the associated problem of estimating the magnitude of the tensions necessary to achieve a desired shape. The analysis is based on a theory they reported earlier, called convexity interval analysis, and it leads to an algorithm that produces suitable tension values for given data automatically, without experimentation or interactive user direction. Three examples are given to illustrate the concepts