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51.
52.
Two newly developed solutions components are described as additional resources for users of the PLATO computer-based Dilemma Counseling System (PLATO DCS). The specific and structural dilemma solutions components contain 69 representative life-choice problems and over 400 specific and general solutions that assist users in solving their psychological dilemmas. Computer-based dilemma counseling was examined empirically by assessing self-reported problem improvement in 2 groups of undergraduate students treated on PLATO DCS (n?=?48) or in a no-contact control group (n?=?62). Ss who used PLATO DCS showed significantly greater improvement in their problems than the control group 1 wk after treatment. This difference tended to persist 1 mo after treatment. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
53.
Although it seems that gecko adhesion research is a relatively young branch of science, this recently rediscovered work presents some very old studies with quite remarkable findings. The publication of Dr. F. Weitlaner from 1902 is very impressive, as it covers many recently published topics and – even more impressively – often comes to the same conclusions and provides similar results compared with current publications. Weitlaner published his paper in German which was – at that time – very common in science. This makes it almost impossible for today's international community of bioinspired adhesion researchers to enjoy and appreciate this early gem of scientific work. Thus, we have decided to translate his paper in the hope that it finds the attention it deserves and that it inspires us to stay curious and pursue answers to the questions which have been asked for over a century. 相似文献
54.
Strain steps are applied to elastomers in a pneumatic relaxometer and monitored by small‐angle X‐ray scattering (SAXS). The relaxometer provides a rise time of 13 ms for strain pulses of step height Δε = ±1 in strain. The basic character of the 2D SAXS frames is examined and corresponding invariants Q(t) are analyzed. Three thermoplastic polyurethanes (TPU) of hardness 85 Shore A with different soft segments are studied both unannealed and annealed. The first response of all materials is a fast morphology conversion which finishes within tmc =250 ms. Because it has been untraceable, it is characterized by a settling stroke Q(tmc) ? Q(0). The second response is a slow morphology adjustment process which complies with logarithmic relaxation. It is characterized by a relaxation rate DQ = Q(10 t)/Q(t) ? 1. Comparison indicates that the nanoscopic morphology relaxation processes appear to have little direct relation to the macroscopic stress relaxation curves. The materials differ with respect to hard‐domain morphology stability and morphology recovery. Most unstable is the morphology of the annealed polyether‐based material. It forms nanofibrillary entities when strained. 相似文献
55.
Graham Thiele Dominique Dufour Philippe Vernier Robert O. M. Mwanga Monica L. Parker Elmar Schulte Geldermann Béla Teeken Tesfamicheal Wossen Elisabetta Gotor Enoch Kikulwe Hale Tufan Sophie Sinelle Amani Michel Kouakou Michael Friedmann Vivian Polar Clair Hershey 《International Journal of Food Science & Technology》2021,56(3):1076-1092
This review of the literature on varietal change in sub-Saharan Africa looks in detail at adoption of new varieties of bananas in Uganda, cassava in Nigeria, potato in Kenya, sweetpotato in Uganda and yams in Côte d’Ivoire. The review explored three hypotheses about drivers of varietal change. There was a strong confirmation for the hypothesis that insufficient priority given to consumer-preferred traits by breeding programmes contributes to the limited uptake of modern varieties (MVs) and low varietal turnover. Lack of evidence meant the second hypothesis of insufficient attention to understanding and responding to gender differences in consumer preferences for quality and post-harvest traits was unresolved. The evidence on the third hypothesis about the informal seed system contributing to slow uptake of MVs was mixed. In some cases, the informal system has contributed to rapid uptake of MVs, but often it appears to be a barrier with inconsistent varietal naming a major challenge. 相似文献
56.
Control concepts for an active vibration isolation system 总被引:1,自引:0,他引:1
F. Kerber S. Hurlebaus B.M. Beadle U. Stbener 《Mechanical Systems and Signal Processing》2007,21(8):3042-3059
In the fields of high-resolution metrology and manufacturing, effective anti-vibration measures are required to obtain precise and repeatable results. This is particularly true when the amplitudes of ambient vibration and the dimensions of the investigated or manufactured structure are comparable, e.g. in sub-micron semiconductor chip production, holographic interferometry, confocal optical imaging, and scanning probe microscopy. In the active anti-vibration system examined, signals are acquired by extremely sensitive vibration detectors, and the vibration is reduced using a feedback controller to drive electrodynamic actuators. This paper deals with the modeling and control of this anti-vibration system. First, a six-degree-of-freedom rigid body model of the system is developed. The unknown parameters of the unloaded system, including actuator transduction constants, spring stiffness, damping, moments of inertia, and the vertical position of the center of mass, are determined by comparing measured transfer functions to those calculated using the updated model. Finally, different strategies for actively controlling the vibration isolation system are considered. 相似文献
57.
We present a scalable solution to render complex scenes from a large amount of viewpoints. While previous approaches rely either on a scene or a view hierarchy to process multiple elements together, we make full use of both, enabling sublinear performance in terms of views and scene complexity. By concurrently traversing the hierarchies, we efficiently find shared information among views to amortize rendering costs. One example application is many‐light global illumination. Our solution accelerates shadow map generation for virtual point lights, whose number can now be raised to over a million while maintaining interactive rates. 相似文献
58.
Gavin P. Horn Richard M. Kesler Steve Kerber Kenneth W. Fent Tad J. Schroeder William S. Scott 《Ergonomics》2018,61(3):404-419
Firefighters’ thermal burden is generally attributed to high heat loads from the fire and metabolic heat generation, which may vary between job assignments and suppression tactic employed. Utilising a full-sized residential structure, firefighters were deployed in six job assignments utilising two attack tactics (1. Water applied from the interior, or 2. Exterior water application before transitioning to the interior). Environmental temperatures decreased after water application, but more rapidly with transitional attack. Local ambient temperatures for inside operation firefighters were higher than other positions (average ~10–30 °C). Rapid elevations in skin temperature were found for all job assignments other than outside command. Neck skin temperatures for inside attack firefighters were ~0.5 °C lower when the transitional tactic was employed. Significantly higher core temperatures were measured for the outside ventilation and overhaul positions than the inside positions (~0.6–0.9 °C). Firefighters working at all fireground positions must be monitored and relieved based on intensity and duration.
Practitioner Summary: Testing was done to characterise the thermal burden experienced by firefighters in different job assignments who responded to controlled residential fires (with typical furnishings) using two tactics. Ambient, skin and core temperatures varied based on job assignment and tactic employed, with rapid elevations in core temperature in many roles. 相似文献
59.
60.
Monte-Carlo rendering requires determining the visibility between scene points as the most common and compute intense operation to establish paths between camera and light source. Unfortunately, many tests reveal occlusions and the corresponding paths do not contribute to the final image. In this work, we present next event estimation++ (NEE++): a visibility mapping technique to perform visibility tests in a more informed way by caching voxel to voxel visibility probabilities. We show two scenarios: Russian roulette style rejection of visibility tests and direct importance sampling of the visibility. We show applications to next event estimation and light sampling in a uni-directional path tracer, and light-subpath sampling in Bi-Directional Path Tracing. The technique is simple to implement, easy to add to existing rendering systems, and comes at almost no cost, as the required information can be directly extracted from the rendering process itself. It discards up to 80% of visibility tests on average, while reducing variance by ∼20% compared to other state-of-the-art light sampling techniques with the same number of samples. It gracefully handles complex scenes with efficiency similar to Metropolis light transport techniques but with a more uniform convergence. 相似文献