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排序方式: 共有247条查询结果,搜索用时 15 毫秒
1.
System Test Planning of Software: An Optimization Approach 总被引:1,自引:0,他引:1
Chari K. Hevner A. 《IEEE transactions on pattern analysis and machine intelligence》2006,32(7):503-5099
This paper extends an exponential reliability growth model to determine the optimal number of test cases to be executed for various use case scenarios during the system testing of software. An example demonstrates a practical application of the optimization model for system test planning. 相似文献
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In this study the interaction of applied N with different irrigation schedules on grain yields and N use efficiency of wheat was investigated in two Inceptisols of the Nigerian savanna during 1978–80. Irrigation intervals ranged from 7 to 28 days at Kadawa and 5 to 10 days at Bakura while the N rates varied from 0 to 200 kg per ha. Both grain yield and N uptake increased significantly with increasing N rates at both the locations. The magnitude of increase in yield and N uptake decreased substantially when the irrigation interval became longer. This interaction was very pronounced at Bakura where the soil is highly porous, excessively drained and extremely poor in moisture retention capacity. Longer irrigation intervals produced grains with slightly higher N content but the difference was not significant. Higher N rates and fewer irrigations gave lower fertilizer N recovery. 相似文献
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Consider the robust network design problem of finding a minimum cost network with enough capacity to route all traffic demand
matrices in a given polytope. We investigate the impact of different routing models in this robust setting: in particular,
we compare oblivious routing, where the routing between each terminal pair must be fixed in advance, to dynamic routing, where routings may depend arbitrarily on the current demand. Our main result is a construction that shows that the
optimal cost of such a network based on oblivious routing (fractional or integral) may be a factor of Ω(log n) more than the cost required when using dynamic routing. This is true even in the important special case of the asymmetric
hose model. This answers a question in (Chekuri, SIGACT News 38(3):106–128, 2007), and is tight up to constant factors. Our proof technique builds on a connection between expander graphs and robust design
for single-sink traffic patterns (Chekuri et al., Networks 50(1):50–54, 2007). 相似文献
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Rastogi NK 《Critical reviews in food science and nutrition》2011,51(8):705-722
The demand for convenience foods of the highest quality in terms of natural flavor and taste, and which are free from additives and preservatives, has spurred the need for the development of a number of non-thermal approaches to food processing, of which ultrasound technology has proven to be very valuable. Increasing number of recent publications have demonstrated the potential of this technology in food processing. A combination of ultrasound with pressure and/or heat is a promising alternative for the rapid inactivation of microorganisms and enzymes. Therefore, novel techniques like thermosonication, manosonication, and manothermosonication may be a more relevant energy-efficient processing alternative for the food industry in times to come. This review aims at identifying the opportunities and challenges associated with this technology. In addition to discussing the effects of ultrasound on foods, this review covers various areas that have been identified as having great potential for future development. It has been realized that ultrasound has much to offer to the food industry such as inactivation of microorganisms and enzymes, crystallization, drying, degassing, extraction, filtration, homogenization, meat tenderization, oxidation, sterilization, etc., including efficiency enhancement of various operations and online detection of contaminants in foods. Selected practical examples in the food industry have been presented and discussed. A brief account of the challenges in adopting this technology for industrial development has also been included. 相似文献
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Ecofriendly materials are becoming a need of the day. We have severe setback when there is lot of use of agro wastes in plastics. To reduce pure plastic use in agriculture, this study has been made to find some remedial measure. In the process, we sought the effect of addition of rice husk (RH) in polyvinylchloride (PVC) on the dielectric properties at different frequency and temperature has been studied. Measurements have been performed in the frequency range from 1 to 10 kHz and temperature range of 32–80°C. The experimental results show that dielectric constant (ε′) increases with the addition of RH in PVC. Dielectric constant (ε′) decreases with increasing frequency, which indicates that the major contribution to the polarization comes from orientation polarization. Dielectric constant (ε′) increases with increasing temperature due to greater freedom of movement of dipoles within PVC at higher temperatures. A theoretical model for dielectric constant with temperature and frequency dependent is proposed. Experimental results are in good agreement with the proposed theoretical model. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
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Preliminary analysis was performed to assess contamination levels in roadside soils, distribution behavior and human exposure with Polycyclic Aromatic Hydrocarbons (PAHs) during summer, winter, rainy, and autumn during 2013 in one of the developing cities of northern India. The concentration of PAHs was measured at ten different locations (at 1, 2, and 3 m) from roadside soil. Recovery range was 30% and 80% with lower value corresponding to the lower molecular weight PAHs compound. Identification and quantification of PAHs was done by GC-FID. Average PAHs concentration (city average) was found to be 16.53, 4.04, 17.49, and 7.82 μg g?1, during summer, winter, autumn, and the rainy seasons, respectively. Average concentration of low and high carcinogenic PAHs during summer, winter, autumn, and rainy was 5.1 and 31.29, 2.1 and 6.4, 4.74 and 35.08, 3.97 and 12.77μg g?1, respectively. The average ratio of low and high carcinogenic PAHs was found to be 1:6, 1:3, 1:7.6, and 1:3.21 during summer, winter, autumn, and the rainy seasons at most intercepts. Dib(ah)A and B(a)P were the two individual PAHs found in highest concentration during summer, winter, and the rainy seasons, whereas B(a)P and IP were individual PAHs found in highest concentration during autumn. It was also analyzed that high carcinogenic PAHs concentration was quite higher (around 85%) in comparison to low carcinogenic PAHs (around 15%) at most intercepts. This article also deals with the behavior of PAHs at places of average/high population and traffic density intercepts. Five-ringed PAHs were in highest concentration at all intercepts and seasons. Two-tailed T test was applied for authenticity of the data and results. Toxic equivalency factor of B(a)P and Dib(ah)A was maximum as compared to other PAHs. 相似文献
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