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131.
The logical input device model, as is adopted in the standardized graphics package GKS, has been an accepted basis for producing device-independent graphics systems. However, when used in highly interactive graphical applications, the logical input device model does not provide sufficient support for a number of fundamental issues inherent to interaction. This paper reopens a discussion which questions the functionality provided by the logical input device model when brought in conjunction with interaction. In particular, the logical input device model does not support the notion of input/output symmetry. CR Categories: 1.3.4 [Computer graphics]: Graphics utilities- graphics packages; 1.3.6 [Computer graphics]: Methodology and techniques- device independence, interaction techniques 相似文献
132.
133.
Hagen Kenneth M.; Gutkin Terry B.; Wilson Caryll Palmer; Oats Robert G. 《Canadian Metallurgical Quarterly》1998,13(2):169
This experimental study investigated whether self-efficacy perceptions pertaining to working with difficult-to-teach children could be increased for pre-service teachers using vicarious experience and verbal persuasion. 89 pre-service teachers were randomly assigned to groups. The experimental group was shown a 33-minute videotape describing and demonstrating effective behavior-management procedures, including supportive teacher testimonials and published research. A control group watched a placebo videotape of similar length detailing society's treatment of handicapped people. Data analyses indicated that the experimental group exceeded the control group on two of four self-efficacy measures. Results are discussed in terms of how enhancing teachers' self-efficacy perceptions might be used to "prime the pump" for consultation services. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
134.
Eine Grundvoraussetzung für die Einführung der thermomechanischen Behandlung beim Profilwalzen ist die Beherrschung der örtlichen Vorgänge im Walzspalt. Hierzu bietet sich die Finite-Elemente-Methode (FEM) als Hilfsmittel zur Ermittlung der örtlichen Prozeßparameter Vergleichsformänderung, Vergleichsformänderungsgeschwindigkeit und Temperatur an. Werkstoffmodelle können zur Beschreibung der örtlichen physikalisch-metallurgischen Vorgänge in einem Material und zur weiteren Entwicklung der FEM verwendet werden. Über die möglichen Wege für die Simulation des Profilwalzens mit FEM und Werkstoffmodellen sowie durch Verwendung von Warmumformsimulationen am IBF und am IEHK wird in dieser Arbeit berichtet. Walzungen im Labormaßstab von 4 Stichen der Kaliberreihe Oval-Quadrat werden Rechenergebnissen für die Stahlsorten C 35 und 50 CrV 4 gegenübergestellt. Ergebnisse aus Versuchswalzungen und Warmzugsimulationen für die Stahlsorte 50 CrV 4 werden verglichen und diskutiert. Erläuterungen über die allgemeine Anwendung der hier verwendeten Arbeitsroutine werden am Ende dieser Arbeit gemacht. Die Ergebnisse zeigen die Bedeutung dieser Arbeitsroutine für die Simulation des Profilwalzens. 相似文献
135.
In nanofabrication the generation of phonons and secondary electrons by an incoming ion in a specimen gets important in limiting the resolution of the fabricated structures. A model is presented for calculating the effect of ion beam parameters (mass and energy) on the resolution and the production yield. In this model the phonon and secondary electron effect are calculated based on results for the scattering of the ions obtained with the Monte Carlo simulation program TRIM. The fabrication resolution is simulated for implantation, sputtering and beam induced etching and beam induced deposition.
Some preliminary results are given which show that the best resolution can be obtained for ions with high mass at low energy for all discussed fabrication techniques, while even the production yield is relatively high at these parameters. 相似文献
136.
A ramped dielectric stress measurement, suitable for fast wafer level reliability (fWLR) monitoring, is assessed for thin gate oxide thicknesses down to 2.2 nm. Severe difficulties usually occur for the reliable detection of soft/hard breakdown in a short time interval and due to high direct tunneling currents. These are discussed and an exponentially ramped current stress is introduced tackling the problems. Early oxide fails were covered by a fast voltage ramp carried out before the current ramp. The advantages of the method are highlighted which has already been implemented for fWLR monitoring in high volume production on scribe line structures. 相似文献
137.
DS Ernst P Brasher N Hagen AH Paterson RN MacDonald E Bruera 《Canadian Metallurgical Quarterly》1997,13(6):319-326
The present study analyses cell loss and proliferation which account for the decrease in the number of germ cell populations in the senile male Octodon degus. This is a good model to study ageing in wild animals, since it has recently been incorporated as a laboratory animal but still has a high degree of genetic heterogeneity, thus representing a situation found in natural systems. The cell loss from pachytene spermatocytes to round spermatids is estimated by cell counts in the cross section of seminiferous tubules. DNA testicular synthesis is measured by scintillation counting and the index of labelling of spermatogonia by radioautography of testes comparing sexually mature young animals and senile animals. Other determinations in both groups are testis weight, thickness of the albuginea and tubular wall, daily sperm production, percentage of depleted seminiferous tubules and nuclear cell diameters of germ cells. The results suggest a decrease in the number of cell population in the senile animals resulting from an increase in physiological cell loss coupled with a decreased proliferative spermatogonial activity. There is also a decreased yield of meiosis in terms of round spermatid production. Lowered testosterone levels both in plasma and testicular parenchymal fluid are found in senile animals. All these senescent changes reflect an altered remodelling activity of the seminiferous epithelium and presumably also of Leydig cells. 相似文献
138.
SC Mitra VS Venkataseshan S von Hagen PT Barton G Delshad J Gil 《Canadian Metallurgical Quarterly》1997,89(2):238-241
OBJECTIVE: To determine the changes in the vessel-wall thickness and the radius of the lumen in tertiary-stem villi of the placenta with advancing gestational duration and their relationship to umbilical artery Doppler flow studies. METHODS: Placentas from 63 miscarriages and preterm and term deliveries (between 19 and 40 weeks) were used for morphometric study of the tertiary-stem villi vessels. Each woman had undergone Doppler flow study of the umbilical artery. The resistance index (RI) was determined from the Doppler flow velocity waveform. Placental paraffin sections of 4-micron thickness were stained with hematoxylin and eosin and with periodic acid-Schiff reagents. The tertiary-stem villi and their vessels were examined microscopically and assessed morphometrically using a personal computer with math co-processor and a touch-sensitive screen overlying a video monitor. The monitor received microscopic images from a video camera that was mounted on a microscope. We determined vessel-wall thickness by tracing the outer and inner circumferences of digitized vessel-wall images. RESULTS: Wall thickness, but not lumen size, of the tertiary-stem villi vessels decreased significantly overall at a rate of 0.63micron/week (P < .001). The rate of decrease was 0.64micron/week (P < .001) during the second trimester and 0.50micron/week (P < .001) during the third trimester. There was a significant correlation between the decrease in thickness and in RI (r = 0.83 [P < .001], r = 0.78 [P < .001] in the second and third trimesters, respectively). Resistance indices were all within normal limits. CONCLUSIONS: Placental tertiary-stem villi vessel-wall thickness decreases with advancing gestational age. There is a correlation between the changes in RI of the umbilical artery Doppler flow and the changes in mean wall thickness of the placental vessels. 相似文献
139.
140.
In this article, the authors determine the extent to which several decision heuristics are present in pedestrians' spatial shopping behavior in downtown retail environments. Two factors, length of the observed route and observed sequence in which destinations are visited, were used to define temporal heuristics. Further, two spatial heuristics were investigated: the tendency of some pedestrians to choose first the destination farthest away from the point they entered the city center and the tendency of others to choose first the destination closest to their entry point. Empirical analysis demonstrated that only a small proportion of the pedestrians reveals optimal choice behavior.An earlier version of this paper was presented at the 11th Pacific Conference, Singapore, July 1989. 相似文献