Finite Element Analysis of the Field Patterns of Higher-Order TE and TM Modes in Rectangular-Groove Guide

The field patterns of the different TE and TM modes in a rectangular-groove guide are analysed by finite element method. The electric field, magnetic field and energy distributions in the groove guide for the dominant TE mode, the lowest TM mode and the 1st, 2nd, and 3rd higher-order TE,TM modes are presented. The results show that the low-loss characteristic of rectangular-groove guide seems unreliable. The results in this paper will be of benefit for us to understand the transmission characteristics of rectangular-groove guide, and will be of practical significance in designing groove guide components.     

Refining the In-Parameter-Order Strategy for Constructing Covering Arrays

Covering arrays are structures for well-representing extremely large input spaces and are used to efficiently implement blackbox testing for software and hardware. This paper proposes refinements over the In-Parameter-Order strategy (for arbitrary t). When constructing homogeneous-alphabet covering arrays, these refinements reduce runtime in nearly all cases by a factor of more than 5 and in some cases by factors as large as 280. This trend is increasing with the number of columns in the covering array. Moreover, the resulting covering arrays are about 5 % smaller. Consequently, this new algorithm has constructed many covering arrays that are the smallest in the literature. A heuristic variant of the algorithm sometimes produces comparably sized covering arrays while running significantly faster.     

River wildlife databases and their value for sensitive environmental management

A survey over a 3-year period, which commenced in 1987, of the plant and bird communities along 1200 km of river in Lincolnshire and South Humberside, Eastern England, is described. Analysis of data from 247 km of river recorded a great diversity of wildlife, comprising 570 species of plant and 80 species of breeding birds. The management value of such surveys is discussed and these include the preparation of detailed maps of each 500m section of river, which illustrate the habitat structure, and plant and bird communities. A maintenance procedure for each 500 m section of river is then agreed between conservation and operations personnel, preventing areas of wildlife importance from being accidentally destroyed. An index which combines both the diversity and rarity of the plant and bird communities is proposed as a measure of conservation importance. This index allows sections of river to be graded according to their conservation value into one of five groups. The surveys also enable predictions to be made of the effects of management actions on the wildlife and provide information by which fundamental reviews of operational activities can be carried out.     

Long-term effects of family-based treatment of childhood obesity.

This study was a 5-year follow-up of obese children who participated in a family-based behavioral weight-control program targeting and reinforcing children and parents for weight loss (Epstein, Wing, Koeske, Andrasik, & Ossip, 1981). Children in the parent-plus-child group showed significantly greater weight reductions after 5 years (–22.7% overweight) than did children in a child-alone target group or in a no-target control group (4.3% and 8.2% overweight, respectively). One third of children in the parent-plus-child group were within 20% of normal weight in comparison with 5% of the children in the no-target control group. Height percentile decreased from the 72nd to the 60th percentile; these changes were negatively related to weight change. These children remained taller than the average child after weight loss, and children of short and medium-height parents were still relatively taller than their parents after 5 years. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of parent weight on weight loss in obese children.

Assessed the effect of parent weight (obese/nonobese parent) and parent control vs child self-control on the weight loss of 41 obese 8–12 yr olds over a 3-yr period. Children of nonobese parents had significantly greater decrease in relative weight after 1 yr, but not after 3 yrs, than children of obese parents. Locus of control was not related to treatment outcome over the 3 yrs. Results suggest that parent weight was related to weight loss, but not weight maintenance, in obese children. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gender dysphoria, gender reorientation, and the clinical management of transsexualism.

Conducted 2 studies of gender dysphoria and postoperative adjustment by transsexuals. Study 1 examined the relation of gender reorientation (approximation of the status of the opposite biological sex) to psychological adjustment in gender dysphorics. Three S groups (75 heterosexual males, mean age 36.7 yrs; 85 homosexual males, mean age 29.8 yrs; and 103 biological females, mean age 27.4 yrs) were studied in multiple regression analyses, with psychological symptoms as criteria and measures of 3 roughly sequential components of gender reorientation (role changes, document changes, and physical changes), age, and education as predictors. Psychological complaints correlated negatively with the earliest phase of reorientation for females and with the later phases for males. Age and education bore little relation to current symptoms. Results suggest that psychological improvement accompanies gender reorientation in both male and female gender dysphorics; the greatest degree of improvement is seen earlier in the process for females. Ss in Study 2 were postoperative transsexuals (32 homosexual males, mean age 33.2 yrs; 9 heterosexual males, mean age 47.7 yrs; and 38 biological females, mean age 32.6 yrs) at least 1 yr after surgery. Follow-up rate was 77.5% for all Ss meeting the 1-yr criterion. Satisfaction with surgery was high, and psychosocial adjustment was acceptable for the majority. Results of both studies support the rationale for clinical intervention in aid of gender reorientation in selected cases. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

New results in the theory of Fowler-Nordheim plots and the modelling of hemi-ellipsoidal emitters.

This paper reports further progress in understanding the theory of emission-area extraction from Fowler-Nordheim plots, and reports some useful interim results derived by modelling field electron emission from hemi-ellipsoidal emitters. The mathematical nature of the relationship between a new approach to emission-area extraction, recently proposed, and older approaches is demonstrated. The new approach is extended to cover field dependence in emission area. Preliminary results are reported from an investigation into the effects of making erroneous assumptions about the tunnelling barrier seen by the electron and the absence of field dependence in emission area. If wrong theoretical assumptions are made, then emission area can be overpredicted by a factor of as much as 10 or 20. On the other hand, if correct theoretical assumptions are made, then the extracted emission area is close to an emission area derived directly from the model calculations. The problematical nature of the concept of emission area, when emission area is a function of field, is pointed out.     

An algorithm for generating color scales for both categorical and ordinal coding

Previous research has shown multihue scales to be well‐suited to code categorical features and shown lightness scales to be well‐suited to code ordinal quantities. We introduce an algorithm, Motley, that produces color scales varying in both hue and lightness, intended to be effective for both categorical and ordinal coding, allowing users to determine both absolute and relative quantities efficiently and accurately. The algorithm first determines the lightnesses of scale colors to maximize perceived lightness differences and establish the lightness ordering, generating separate search spaces for each scale position. It then selects hues by heuristic search to maximize the discriminability of the scale. It produces scales that are ordered with respect to lightness but unordered with respect to hue and thus more discriminable than typical multihue lightness scales. In an experimental evaluation on human subjects, Motley's scales enabled accurate judgments of relative quantity, with response times superior to unordered multihue scales and comparable to ordered lightness scales, and enabled accuracy and speed of judgments of absolute quantity superior to lightness scales and comparable to multihue scales. Published 2009 Wiley Periodicals, Inc., Col Res Appl, 2010.     

A model for the channel noise of MESFETs including hot electron effects

Noise is an important consideration in the reliability of microelectronic circuits determining the sensitivity of the circuits and placing a lower limit on the regions of operation. Proper modeling of noise in integrated circuits is essential for reliable operation. A derivation is given for the channel noise coefficient of FET’s operating in the saturation region. Some simple approximations are made for hot electron effects which can be incorporated into the derivation and accounted for by a numerical integration technique. Experimental results of measured and calculated noise coefficients are compared for depletion mode MESFETs of different gate lengths. This model gives a much more realistic representation of the channel noise coefficients for short gate length devices rather than the simple 2/3 value currently used in circuit simulations.