The role of data networking in the management of BT's SDH network

This paper outlines the history behind the current realisation of the management data communications network for synchronous digital hierarchy (SDH), explaining the various international standards inputs, supplier implementations and illustrating the architecture employed. Message addressing methods are discussed together with the protocols over which they are used. The dimensioning of this network is a key issue of ongoing discussion and impacts the provisioning rates and response times for SDH.     

Parallel fiber-optic SCI links

Parallel fiber-optic links promise to be a key enabling technology for distributed computing, substantially increasing transmission distance and bandwidth. The drive to include more and more processors and I/O devices in parallel-processor complexes has created a need for box-to-box interconnection links capable of delivering bandwidth comparable to system backplanes. Point-to-point links overcome the speed and cost constraints of shared buses. However, copper-based point-to-point links can reliably carry high-speed data only a limited distance. Parallel fiber-optic links substantially increase transmission distance and surpass copper's bandwidth capability. Our research addresses the integration of parallel fiber-optic data links into system designs that require a high-bandwidth link over moderate distances. To demonstrate the feasibility of using parallel fiber-optic technology as a fundamental building block in large-scale commercial and parallel machines, we constructed a link testbed     

Evaluation of three enzymic methods as predictors of in-vivo response to enzyme supplementation of barley-based diets when fed to young chicks

The β-glucan degrading ability of several commercial crude enzyme preparations was determined using three different assay procedures. The assays were based on the ability of the enzymes to reduce the viscosity of a β-glucan solution, to produce reducing sugars from β-glucan or to produce a blue-coloured solution upon hydrolysis of azo-barley-glucan. Regression analysis showed that the relationship between the relative improvements in weight gain of chicks fed a barley-based diet that was supplemented with different concentrations of different enzyme and in-vitro enzyme activity when the azo-barley-glucan and reducing sugar assays were used was quadratic. A linear relationship was observed for the viscosity method. The R² values for both weight gain and feed to gain ratio were highest for the azo-barley-glucan method but the other methods yielded similar values under appropriate assay conditions (ie concentration of enzyme). The azo-barley-glucan method, nevertheless, is the assay recommended as it is by far the simplest of the three assays and it yields a low coefficient of variation.     

The singularity expansion method applied to perpendicular crossed wires over a perfectly conducting ground plane

The singularity expansion method (SEM) has been applied to determine natural resonances of a set of perpendicular crossed wires over a perfectly conducting ground plane. The variation of the natural resonances and the mode and coupling vectors have been studied as parameters of the system varied.     

An IC Control Unit for Generating Random and Nonrandom Events

A system has been designed that wil generate user-controlled temporal events and two independent sequences of random events over selectable time periods. The duration and frequency of the events is set by front panel controls over a temporal range determined by the user. This system is suitable for automating experiments in biological and behavioral research.     

The effect of training upon accuracy and variability in interpersonal perception.

The relationship between accuracy and variability in estimations and the effects of a training program in interpersonal relations upon interpersonal perception were investigated in 72 senior medical students divided into experimental and control groups. The experimental group received training in physician-patient relationships and the control did not receive such training. "Contrary to expectation, the experimental group tended to become less accurate than the control group… . These results, which agree with a hypothesis advanced by Cronbach, suggest that training programs devoted to increasing accuracy of interpersonal perception run the risk of decreasing accuracy when they increase the trainee's responsiveness to individual differences." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The generality of accuracy and response sets in interpersonal perception.

In experiment I, 15 measures of Ss' perception of other people were obtained. Only 8 of the intercorrelations were significant. In experiment II, Ss' judgments of other people were obtained in 3 sessions distributed over a school year. Comparison of the 3 sets of judgments indicated low relationship among accuracy scores, high relationship among response-set scores. Assumption of general ability of interpersonal perceptiveness is untenable; reliability of interpersonal perception may be due to consistency in response set rather than in ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The theory of neutral and weakly selected genes

The controversy over whether a major fraction of evolutionary allele substitutions and protein polymorphisms in natural populations is due to random drift of neutral mutations remains unresolved; but the discussion has led to extensions of population genetic theory, particularly in stochastic models. The work of Maruyama in seeking quantities that are not strongly dependent on assumptions about population structure is particularly discussed. Under some circumstances, and perhaps quite generally, the probability of eventual fixation of a mutant gene, the total number of heterozygotes in which the gene is involved before its fixation or less, and the total number of heterozygotes during the time the gene has a specified frequency in the entire population have this desirable property. Whether there are many mutants that are so nearly neutral as to be unaffected by selective forces or not, it is clear that there are many loci at which selection is very weak and some of the evolutionary consequences of this are discussed briefly.     

A Comparison of Diode-Clamped and Cascaded Multilevel Converters for a STATCOM With Energy Storage

The progression of distributed generation within a bulk power system will lead to the need for greater control of transmission-line power flows. Static synchronous compensators (STATCOMs) provide a power-electronics-based means of embedded control of transmission-line voltage and power flows. The integration of energy storage with a STATCOM can extend traditional STATCOM capabilities to four-quadrant power flow control and transient stability improvement. This paper discusses energy storage systems (ESSs) integrated with conventional and multilevel bidirectional power converters for a hybrid STATCOM/ESS. Conventional, diode-clamped, and cascaded multilevel converter-based STATCOM/ESSs are developed, and their performances for a variety of power system applications are compared using battery energy storage. The advantages and disadvantages of each topology are presented. Both simulation and experimental results are provided to validate the conclusions