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61.
62.
Plasma-chemical etching of silicon and silicon compounds is reviewed. It is shown that present data indicates that fluorine atoms and molecules are the main particles responsible for etching of silicon and that atomic fluorine is the main active particle for etching of silicon dioxide. Insufficient data exists to establish the contribution of charged and excited states to the etching of silicon and its compounds but oxygen atoms and molecules are seen to have a strong influence and fluorocarbon radicals can passivate the surface by forming polymer films. 相似文献
63.
64.
Investigated the relationship of the work challenge experienced by 85 engineers at the beginning of their career to their subsequent job performance, professional contributions, and competence. Engineers whose initial job experience involved challenging technical work tended to contribute to knowledge relatively early and to maintain professional competence and good job performance during their careers. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
65.
The goal of this study was to determine if traffic signals that are synchronized along a route are associated with fewer red-light violations than traffic signals that are not synchronized. A total 3600 cycles of traffic signals at 12 intersections along 2 major urban arteries were observed. Synchronized intersections were effective in reducing the likelihood of red-light running (RLR) by (a) providing fewer opportunities than nonsynchronized intersections for RLR and (b) having a lower rate of RLR relative to the number of opportunities. After adjustment for the number of opportunities, the odds of entering the intersections in red in synchronized intersections were nearly 1/7 the odds of RLR in nonsynchronized intersections. Congestion reduced the effectiveness of synchronized intersections relative to nonsynchronized intersections. Male drivers were slightly more likely to run red lights than female drivers, and the effects of synchronization were fairly constant across age, gender, and the presence or absence of passengers. Actual or potential applications of this research involve signal synchronization to reduce aggressive driving in general and RLR in particular. 相似文献
66.
Lattice-based flow field modeling 总被引:2,自引:0,他引:2
Wei X Zhao Y Fan Z Li W Qiu F Yoakum-Stover S Kaufman AE 《IEEE transactions on visualization and computer graphics》2004,10(6):719-729
We present an approach for simulating the natural dynamics that emerge from the interaction between a flow field and immersed objects. We model the flow field using the lattice Boltzmann model (LBM) with boundary conditions appropriate for moving objects and accelerate the computation on commodity graphics hardware (GPU) to achieve real-time performance. The boundary conditions mediate the exchange of momentum between the flow field and the moving objects resulting in forces exerted by the flow on the objects as well as the back-coupling on the flow. We demonstrate our approach using soap bubbles and a feather. The soap bubbles illustrate Fresnel reflection, reveal the dynamics of the unseen flow field in which they travel, and display spherical harmonics in their undulations. Our simulation allows the user to directly interact with the flow field to influence the dynamics in real time. The free feather flutters and gyrates in response to lift and drag forces created by its motion relative to the flow. Vortices are created as the free feather falls in an otherwise quiescent flow. 相似文献
67.
Footprint area sampled texturing 总被引:2,自引:0,他引:2
Chen B Dachille F Kaufman AE 《IEEE transactions on visualization and computer graphics》2004,10(2):230-240
We study texture projection based on a four region subdivision: magnification, minification, and two mixed regions. We propose improved versions of existing techniques by providing exact filtering methods which reduce both aliasing and overblurring, especially in the mixed regions. We further present a novel texture mapping algorithm called FAST (footprint area sampled texturing), which not only delivers high quality, but also is efficient. By utilizing coherence between neighboring pixels, performing prefiltering, and applying an area sampling scheme, we guarantee a minimum number of samples sufficient for effective antialiasing. Unlike existing methods (e.g., MlP-map, Feline), our method adapts the sampling rate in each chosen MlP-map level separately to avoid undersampling in the lower level l for effective antialiasing and to avoid oversampling in the higher level l+1 for efficiency. Our method has been shown to deliver superior image quality to Feline and other methods while retaining the same efficiency. We also provide implementation trade offs to apply a variable degree of accuracy versus speed. 相似文献
68.
69.
Interactive wireless virtual colonoscopy 总被引:1,自引:0,他引:1
We present an interactive virtual colon navigation system on a PDA that is a client-server system over a wireless network.
For improving the quality of the rendering results on the PDA, the overall rendering speed, and the user interactivity, we
propose three novel methods and adapt a GPU-based direct volume rendering technique. Using these proposed methods, our system
can support approximately a two times faster navigation speed and 17 percent better PSNR than previous remote visualization
methods with a 512×512×361 volumetric colon CT data using a PDA device over 802.11b wireless network. 相似文献
70.
Ogras U.Y. Marcillescu R. Hyung Gyu Lee Choudhary P. Marculescu D. Kaufman M. Nelson P. 《Micro, IEEE》2007,27(5):86-95
Although a significant amount of theoretical work supports the potential of NoC architectures, such results need to be demonstrated by actual implementations before the NoC paradigm becomes a reality. Besides demonstrating the feasibility of the overall approach, prototyping enables accurate evaluation of power, performance, area, and various design trade-offs. This article presents four NoC prototypes, discusses the challenges associated with their design, and assesses the potential of the NoC approach. 相似文献