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891.
A powerful method for the phase retardation measurement of a reflective liquid crystal cell is presented. The proposed method is based on the heterodyne interferometer theory for probing cell parameters. Due to common-path optical arrangement, a fast measurement with high accuracy and sensitivity was possible. Both theoretical analysis and experimental procedures are presented. The experimental results agree well with that obtained theoretically. 相似文献
892.
Mark Bebbington Chin-Diew Lai Ričardas Zitikis 《Methodology and Computing in Applied Probability》2007,9(1):1-20
An important problem in reliability is to define and estimate the optimal burn-in time. For bathtub shaped failure-rate lifetime
distributions, the optimal burn-in time is frequently defined as the point where the corresponding mean residual life function
achieves its maximum. For this point, we construct an empirical estimator and develop the corresponding statistical inferential
theory. Theoretical results are accompanied with simulation studies and applications to real data. Furthermore, we develop
a statistical inferential theory for the difference between the minimum point of the corresponding failure rate function and
the aforementioned maximum point of the mean residual life function. The difference measures the length of the time interval
after the optimal burn-in time during which the failure rate function continues to decrease and thus the burn-in process can
be stopped.
相似文献
893.
A temperature distribution sensing system based on the reflection spectrum of a 70 mm apodized chirped fiber Bragg grating has been demonstrated. Reflection variations created by the Fabry-Perot effect due to the intra-grating wavelength shift are presented. By fitting a parametric transfer matrix model of the grating response to measured spectra, the temperature change, position and width of a localized temperature change are obtained. This system is particularly attractive of its simplicity, high spatial resolution and ability in measuring a non-monotonic distribution. Experiments to measure two localized heating regions along the grating indicate that the technique is promising for measuring more complex temperature profiles. 相似文献
894.
在这篇论文中,作者用Langevin随机微分方程来描写不规则星系中任何一个作准布朗型运动的星体的随机运动.并用相空间中的表示点(X.X)来描写其每一随机态.用Fokker-Planck方程计算出了这些随机态的稳态几率密度fs(X.X);同时,用此fs(X.X)计算出了随机运动星体的速度和位置的方差与涨落.进而作者发现:随机运动的星体满足一种天体的不确定关系. 相似文献
895.
896.
A major shipping company in Hong Kong is faced with several logistical and allocation problems. It needs to find a better way to allocate empty containers that are transported from the Middle East to ports in the Far East, subject to vessel schedules and capacities. It needs to know what to do when the supply of empty containers is less than the demand, and it needs to determine the mix of container types that the company should maintain in the long run. To deal with these challenges, a simulation model of the shipping company's operational activities was developed. Heuristic search was employed to identify the policies that yield the lowest operating cost in terms of leasing, storage, pick-up, drop-off and other charges. What makes the problem difficult is that the forecasts of future export movement as well as the demand for empty containers change continually and the company is faced with the possibility of lost sales if containers are not available when requested by customers. This study provided insights that resulted in substantial savings to the shipping company while increasing customers' satisfaction. 相似文献
897.
Economic manufacturing quantity, process mean, and specification limits setting are three important methods for the inventory and quality control problems. In the imperfect production system, we usually consider the manufacturing quantity for reducing the inventory cost, determine the process level for reducing the production cost, and select the specification limits for screening the products. In this paper, we propose the above integrated model based on the application of rectifying inspection plan for obtaining maximum expected total profit of product. The asymmetric quadratic quality loss function is adopted for measuring the product quality. The sensitivity analyses of parameters are provided for illustration. 相似文献
898.
899.
After the announcement in the Vol.23, No.4 issue of JMRE, some progress has been made. Profs Giorgio Letta (Pisa) and Luca Pratelli gave a proof without any use of ch.f. of half of the result, as follows: 相似文献
900.