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91.
92.
Modeling and simulation of pollutants transport in rivers 总被引:1,自引:0,他引:1
This paper is devoted to mathematical modeling and computer simulation of diffusion and transport of chemicals in rivers. We present one-, two-, and three-dimensional models in terms of time-dependent convection–diffusion–reaction differential equations, further we give the finite difference approximation and appropriate numerical algorithms for these models, and finally we discuss briefly the computer implementation of this methodology in a user friendly software package. To verify the model and the computer code we have used it to study the diffusion and transport of chemicals, in this case NO3 and PO4, in two rivers in Western Georgia flowing into the Black Sea. Namely, we considered the river Khobistskali subject to pollution sources Ochkhomuri and Chanistskali river Choga polluted with NO3. 相似文献
93.
L. Huber 《Accreditation and quality assurance》1996,1(1):24-34
The quality process for commercial analytical equipment starts with the selection of the vendor. It is recommended that vendors
be selected who are recognized as having quality processes in place for instrument design, development, manufacturing, testing,
service, and support, for example, ISO 9001 registration. When the instrument arrives in the laboratory, the installation
process should follow well-documented procedures. This includes a visual inspection that the instrument is not damaged and
checking that the instrument, documentation and accessories such as cables and tubings are complete. Before the instrument
is used it should be verified that it meets functional and performance specification. During operation the instruments should
be periodically inspected and tested, verified to meet performance, and calibrated. The instrument should be labeled with
the calibration status, indicating the dates of the last successful and the next performance verification and calibration.
Defective instruments should be removed from the testing area or should at least be labeled as being "out of order."
Received 23 August 1995 Accepted 6 September 1995 相似文献
94.
95.
In this paper, we investigate the existence of learning curves in software development. Under the assumption of independent and identical distribution (iid) of programmer’s experience and identical effort-experience learning curve relationship for different programmers, we illustrate the existence of an exponentially decreasing learning curve relationship between a programmer’s effort and his/her ICASE tool experience, and show that the effort-experience relationship is inelastic when a programmer’s ICASE tool experience is low. We analyze the impact of our assumptions on actual software development effort, and propose a tight probability upper bound and a central-limit theorem based probability estimator for estimating the approximate probability that the software development effort will be less than or equal to a certain number. Examples to illustrate the use of the probability estimator are also provided. 相似文献
96.
本文将LLLZ软件应用于粉末状地质化探样品的分析中,应用结果表明,LLLZ软件对原有数据的应用直接、快速,分析方法的选择快速,具有易于开发,使用方便的特点。 相似文献
97.
98.
Zhisheng Lin Rongyo Chang Haitau Lin Chuhua Pan Yuliang Long 《International Journal of Infrared and Millimeter Waves》1998,19(3):569-584
An automatic slotted line system controlled with the micro-computer IBM 80486 which we have developed had been reported. In this paper, the measuring principles and the software designs of impedance, attenuation, phase shift and detection law of diode measurement to make use of this system will be described, some typical measurement results will be given. This method is adaptable for MM-Wave band and other Micro-wave band. 相似文献
99.
Different methods for the calculation of the sound reduction index using modal analysis are described. The calculations use two steps: a vibratory study to determine the transverse displacement of the plate and a study of radiation. Orthotropic plates are studied in particular and the resulting calculation algorithm has been programmed. Initial hypotheses are indicated, as well as results obtained for various plates or partitions. Modal analysis calculation results are then compared to results of the Cremer-Sewell approach. 相似文献
100.
P. Zeephongsekul 《Journal of Optimization Theory and Applications》1996,91(1):215-233
We present a software release policy which is based on the Stackelberg strategy solution concept. The model formulated assumes the existence of two type of producers in the market, the leader and follower. The resulting release policy combines both cost factors and a loss of opportunity factor which is the result of competition between the rival producers. We define a Stackelberg strategy pair in the context of our model and, through a series of preliminary results, show that an optimal strategy pair exists. We also present a numerical example which utilizes a software reliability growth model based on the nonhomogeneous Poisson process. Finally, we explore the relative leadership property of the optimal strategies.This work was supported in part by a FOAS Research Grant provided by RMIT. The author would like to thank the referees for constructive suggestions which helped to improve a previous version of this paper. 相似文献