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排序方式: 共有471条查询结果,搜索用时 15 毫秒
31.
Yosef S Sherif 《Microelectronics Reliability》1982,22(1):9-13
There are a number of instances where the problems of non-stationarity, Poisson compounding and double stochasticity arise. In the theory of space-charge limited shot-noise, the number of beats that occur in a given interval of time obey a doubly stochastic process since the Poisson's parameter λ changes randomly due to individual beats. This paper puts forward a doubly stochastic non-stationary compound Poisson process as a model describing damage sustained by military equipment, solar collectors, … etc., due to hailstones. The expected repair cost due to such damage is formulated. 相似文献
32.
Removal of frost from an jupward facing horizontal cooling plate at a subfreezing temperature using a hot water spray is studied experimentally. The variation of the frost layer with time is approximately linear. A simple analytical model predicts the trend of the frost thickness-time change. 相似文献
33.
A prioritization methodology was developed to identify key "hot spot" sectors that are vulnerable to adverse environmental
impacts from trade liberalization. The methodology relies on internationally approved analytical techniques and indicators
relevant to the trade and environment issue. Key outputs of this research include the identification of appropriate economic
and environmental indicators, an information compilation strategy, and a step-wise procedure to perform the prioritization
process. The methodology presented may reduce time and expenses previously incurred in identifying environmental hot spots.
It also may assist in prioritizing actions to mitigate negative consequences of trade liberalization in specific sectors.
Electronic Publication 相似文献
34.
Sherif Saif Hazem M. Abbas Salwa M. Nassar Abdelmonem A. Wahdan 《Microprocessors and Microsystems》2007,31(8):477-486
This paper presents a Field Programmable Gate Array (FPGA) implementation for image/video compression using an improved block truncation coding (BTC) image compression technique. The improvement is achieved by employing a Hopfield neural network (HNN) to calculate a cost function upon which a block is classified as either a high- or a low-detail block. Accordingly, different blocks are coded with different bit rates and thus resulting in better compression ratios. The paper formulates the utilization of HNN within the BTC algorithm in such a way that a viable FPGA implementation is produced. The implementation exploits the inherent parallelism of the BTC/HNN algorithm to provide efficient algorithm-to-architecture mapping. The Xilinx VirtexE BTC implementation has shown to provide a processing speed of about 1.113 × 106 of pixels per second with a compression ratio which varies between 1.25 and 2 bits/pixel, according to the image nature. 相似文献
35.
Reuse of software assets in application development has held promise but faced challenges. In addressing these challenges, research has focused on organizational- and project-level factors while neglecting grass-root level adoption of reusable assets. Our research investigated factors associated with individual software developers’ intention to reuse software assets and integrated them in TAM. Towards that end, 13 project managers were interviewed and 207 software developers were surveyed in India. Results revealed that the technological-level (infrastructure), and individual-level factors (reuse-related experience and self-efficacy) were major determinants. Implications are discussed. 相似文献
36.
Evaluation of Augmented Reality for Rapid Assessment of Earthquake-Induced Building Damage 总被引:1,自引:0,他引:1
This paper discusses the feasibility of using augmented reality (AR) to evaluate earthquake-induced building damage. In the proposed approach, previously stored building information is superimposed onto a real structure in AR. Structural damage can then be quantified by measuring and interpreting key differences between the real and augmented views of the facility. Proof-of-concept experiments were performed in conjunction with large-scale cyclic shear wall tests. In these, CAD images of the walls were superimposed onto the wall specimens. Then, as the wall specimens were deformed under applied loading, the horizontal drifts between the walls and the augmented images were computed using two different techniques and compared with actual wall drifts. The obtained results highlight the potential of using AR for rapid damage detection and indicate that the accuracy of structural displacements measured using AR is a direct function of the accuracy with which augmented images can be registered with the real world. The limitations of the technology, considerations for field implementation, and the potential for other related applications of AR are also discussed. 相似文献
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El-Sayed M. Sherif J. H. Potgieter J. D. Comins L. Cornish P. A. Olubambi C. N. Machio 《Journal of Applied Electrochemistry》2009,39(8):1385-1392
The effects of minor additions of ruthenium (0.14%, 0.22%, and 0.28%) on the passivation of duplex stainless-steel (DSS, Fe–22%Cr–9%Ni–3%Mo)
corrosion in 2 M HCl solutions have been studied using open-circuit potential (OCP), potentiodynamic cyclic polarization,
potentiostatic current–time, electrochemical impedance spectroscopy (EIS), and weight loss measurements. OCP measurements
showed an increased shift in the corrosion potential to more positive values with increasing Ru content. Polarization and
EIS experiments indicated that the presence of Ru and the increase of its content decrease the corrosion rate, critical and
passive current density, and polarization resistance. Moreover, it shifts the corrosion and pitting potentials to more positive
values. Current–time measurements at −100, −50, and 50 mV versus Ag/AgCl also confirmed that the severity of pitting corrosion
decreases with an increasing Ru content. Weight-loss time data showed good agreement with the electrochemical measurements. 相似文献