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111.
H. Courteney 《Cognition, Technology & Work》2000,2(3):142-153
Cognitive engineering has developed enormously over the last fifteen years. Yet, despite many excellent research projects
and publications, its full potential has not been embraced into mainstream system design. This paper will examine the reasons
for this failure and argue that the problem is not simply inertia or lack of education. There are strong organisational influences
that cause resistance to this particular approach. The discipline itself has characteristics that make it fragile in the modern
corporate structure. In addition, the cognitive engineers themselves are not blameless in the equation. They appear to have
done exactly what they criticise the engineering community for doing: they have packaged their product in a manner that is
not ‘user friendly’ to its target population, not structured to suit its application, and not output in the format required.
Suggestions will be made to rectify the situation: a list of actions is proposed for practising cognitive engineers to make
their product more likely to enjoy widespread uptake. 相似文献
112.
113.
本文对三峡水库库尾河段河道特性、入库砂石资源特性、采砂现状及存在的问题等方面进行了研究分析,在此基础上,对三峡水库库尾采砂发展规划提出了建议。 相似文献
114.
三峡水电站调峰运用探析 总被引:1,自引:0,他引:1
对2003年三峡水电站投产以来的调峰运行情况进行分析总结,并结合三峡水库调度原则、梯级枢纽特性、电站机组运行特点、电网系统要求等相关因素对三峡水电站在进入正常运行期后的调峰运用进行了探讨和分析。 相似文献
115.
This study examined whether evaluations (agreements, disagreements), knowledge content (new ideas, justifications), or social cues (SCs) in recent messages affected a current message’s positive or negative SC during asynchronous, online discussions. Using statistical discourse analysis, we modeled 894 messages by 183 participants on 60 high school mathematics topics (typically eight people posted per topic) on a mathematics problem solving website not connected to any class or school. Results showed that recent agreements increased the likelihood of positive SC, whereas justifications reduced it. Disagreements increased the likelihood of negative SC, whereas new ideas reduced it. Meanwhile, recent positive or negative SCs did not affect the likelihood of a subsequent SC. Together, these results suggest that judicious use of positive SCs rather than negative SCs during disagreements can help students both construct knowledge and maintain social relationships. 相似文献
116.
Attila T. Áfra 《Computer Graphics Forum》2012,31(1):75-88
We propose an efficient approach for interactive visualization of massive models with CPU ray tracing. A voxel‐based hierarchical level‐of‐detail (LOD) framework is employed to minimize rendering time and required system memory. In a pre‐processing phase, a compressed out‐of‐core data structure is constructed, which contains the original primitives of the model and the LOD voxels, organized into a kd‐tree. During rendering, data is loaded asynchronously to ensure a smooth inspection of the model regardless of the available I/O bandwidth. With our technique, we are able to explore data sets consisting of hundreds of millions of triangles in real‐time on a desktop PC with a quad‐core CPU. 相似文献
117.
Curvilinear features extracted from a 2D user‐sketched feature map have been used successfully to constraint a patch‐based texture synthesis of real landscapes. This map‐based user interface does not give fine control over the height profile of the generated terrain. We propose a new texture‐based terrain synthesis framework controllable by a terrain sketching interface. We enhance the realism of the generated landscapes by using a novel patch merging method that reduces boundary artefacts caused by overlapping terrain patches. A more constrained synthesis process is used to produce landscapes that better match user requirements. The high computational cost of texture synthesis is reduced with a parallel implementation on graphics hardware. Our GPU‐accelerated solution provides a significant speedup depending on the size of the example terrain. We show experimentally that our framework is more successful in generating realistic landscapes than current example‐based terrain synthesis methods. We conclude that texture‐based terrain synthesis combined with sketching provides an excellent solution to the user control and realism challenges of virtual landscape generation. 相似文献
118.
Daniel Scherzer Chuong H. Nguyen Tobias Ritschel Hans‐Peter Seidel 《Computer Graphics Forum》2012,31(4):1391-1397
The incident indirect light over a range of image pixels is often coherent. Two common approaches to exploit this inter‐pixel coherence to improve rendering performance are Irradiance Caching and Radiance Caching. Both compute incident indirect light only for a small subset of pixels (the cache), and later interpolate between pixels. Irradiance Caching uses scalar values that can be interpolated efficiently, but cannot account for shading variations caused by normal and reflectance variation between cache items. Radiance Caching maintains directional information, e.g., to allow highlights between cache items, but at the cost of storing and evaluating a Spherical Harmonics (SH) function per pixel. The arithmetic and bandwidth cost for this evaluation is linear in the number of coefficients and can be substantial. In this paper, we propose a method to replace it by an efficient per‐cache item pre‐filtering based on MIP maps — such as previously done for environment maps — leading to a single constant‐time lookup per pixel. Additionally, per‐cache item geometry statistics stored in distance‐MIP maps are used to improve the quality of each pixel's lookup. Our approximate interactive global illumination approach is an order of magnitude faster than Radiance Caching with Phong BRDFs and can be combined with Monte Carlo‐raytracing, Point‐based Global Illumination or Instant Radiosity. 相似文献
119.
Jean‐Eudes Marvie Cyprien Buron Pascal Gautron Patrice Hirtzlin Gaël Sourimant 《Computer Graphics Forum》2012,31(7):2087-2095
GPU Shape Grammars provide a solution for interactive procedural generation, tuning and visualization of massive environment elements for both video games and production rendering. Our technique generates detailed models without explicit geometry storage. To this end we reformulate the grammar expansion for generation of detailed models at the tesselation control and geometry shader stages. Using the geometry generation capabilities of modern graphics hardware, our technique generated massive, highly detailed models. GPU Shape Grammars integrate within a scalable framework by introducing automatic generation of levels of detail at reduced cost. We apply our solution for interactive generation and rendering of scenes containing thousands of buildings and trees. 相似文献
120.
Jiawei Ou Feng Xie Parashar Krishnamachari Fabio Pellacini 《Computer Graphics Forum》2012,31(4):1537-1545
We present an importance sampling method for the bidirectional scattering distribution function (bsdf) of hair. Our method is based on the multi‐lobe hair scattering model presented by Sadeghi et al. [ [SPJT10] ]. We reduce noise by drawing samples from a distribution that approximates the bsdf well. Our algorithm is efficient and easy to implement, since the sampling process requires only the evaluation of a few analytic functions, with no significant memory overhead or need for precomputation. We tested our method in a research raytracer and a production renderer based on micropolygon rasterization. We show significant improvements for rendering direct illumination using multiple importance sampling and for rendering indirect illumination using path tracing. 相似文献