Moment-method calculations on apertures using basis singularfunctions

The transmission properties of perforated perfectly conducting screens are of practical interest. The treatment of nonperiodical structures by numerical techniques, such as the method of moments, is very computer intensive. In this paper it is shown that using basis functions that incorporate the edge as well as the corner singularities, the number of unknowns can be drastically reduced. The advantages and limitations of the method are discussed. Numerical results are presented illustrating the transmission properties of arrays of square and rectangular apertures     

Meal patterns in obese and normal weight men: the ''Gustaf'' study

OBJECTIVE: To compare the reported meal patterns between obese and normal weight men. DESIGN: A dietary survey, by means of 12 repeated telephone-administered 24-hour dietary recalls, was conducted in obese and normal weight men. The study period was three months with all seven days of the week included. The contribution of intake types to the reported daily energy intake (EI) was studied as well as the circadian distribution of EI and the reported number of intakes. SUBJECTS: 86 obese men (BMI 37.7 +/- 4.4 kg/m2, mean +/- SD) from the waiting list of the outpatient clinic completed the study altogether with 61 normal weight men (BMI 23.0 +/- 1.9 kg/m2), randomly selected from the Stockholm County Census Bureau. All men were 20-60 years old. RESULTS: Results were analyzed for Group A = all men who completed the study and for Group B = the men who exceeded the CUT-OFF 1 limit for energy intake (reasonably true report as defined by Goldberg). The obvious under-reporters amounted to 73% of the obese and to 28% of the normal weight men. The meal patterns were similar for the obese and the normal weight men. The greatest contributors to EI in both groups were cooked meals, sandwich meals, snacks and breakfast-like meals. The circadian eating pattern was mainly the same in both obese and normal weight men. The reported number of intakes was 5.3 (median) per day in all obese men vs 5.6 in all the controls (P = 0.02), and in Group B 5.3 s 5.9 (P = 0.16) intakes. No specific "obese eating style' could be detected in this study.     

Workshop on late effects of irradiation to the head and neck in infancy and childhood

A summary statement for the Workshop on Late Effects of Irradiation to the Head and Neck in Infancy and Childhood is presented. The Workshop, conducted by the National Cancer Institute with the cooperation of several other organizations, was convened to determine the present status of knowledge about thyroid disease related to irradiation of the head and neck and to develop guidelines with respect to detection, diagnosis, treatment, and followup. It was decided that surgical exploration should be considered for all palpable thyroid nodules, particularly those that are firm and clearly demarcated and appear as a "cold" area on the scan. Persons at risk because of prior irradiation to the head or neck should have regular reexaminations every one to two years.     

Electron tunneling between two-dimensional electronic systems in a heterostructure with a single doped barrier

Electron tunneling in a heterostructure with a single doped barrier was investigated. Analysis of the experimental data showed that all features in the tunneling conductance are due to electron tunneling between two-dimensional electron sheets which appear on different sides of the barrier as a result of ionization of impurities in the barrier. Electron transport between the two-dimensional electron sheets and three-dimensional contact regions does not introduce significant distortions in the measured tunneling characteristics. In such structures there is no current flow along the two-dimensional electron gas; such a current ordinarily makes it difficult to investigate tunneling between two-dimensional electronic systems in magnetic fields. Fiz. Tekh. Poluprovodn. 32, 602–606 (May 1998)     

A MOMENT MATCHING APPROACH FOR MODELLING ATM CELL ARRIVAL PROCESSES

This paper presents a moment matching approach for constructing an equivalent model of an ATM cell arrival process based on inter-cell arrival time measurement. As compared to a renowned parameter-matching technique proposed by Heffes and Lucatoni, the advantage of this approach is that the matching parameters are more easily obtained in real traffic situation. This approach has been tested on an MMBP^[Poisson] process, and results show that only the first four moments are required to capture the key characteristics in this process.     

A 640 by 480 Pixels Readout Circuit for IR Imaging

A readout circuit for a 640 × 480 pixels FPA (focal plane array) has been successfully designed, fabricated and tested. The circuit solution is based on a per pixel source-follower direct injection (SFDI) pre-amplifier. Signal multiplexing is performed in both X and Y direction. The pixel size is 25 m × 25m. The chip is optimized for a QWIP (quantum well infrared photodetector) operating at a temperature of 70 K. The circuit has been realized in a standard 0.8 m CMOS process.