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681.
依据监测参数对系统进行健康评估,可以了解系统在工作过程中的健康状态,并通过预防维修避免系统故障带来的安全隐患。电子设备的健康状态容易受到随机干扰的影响产生虚警从而导致不必要的维修,为此提出一种通过多参数距离度量来构建健康指数从而进 行系统综合健康评估的方法。利用马氏距离对监测的多个系统性能参数时间序列进行降维,基于核函数最优分段间隔估计对数据的直方图分布进行统计,利用加权分数贡献率来构建健康指数。通过电脑的实验与仿真数据进行了验证,给出了单参数异常和多参数同时异常情况下的评估结果。研究表明,该方法不仅能对系统的健康状态进行有效的评估,而且能够降低随机突发干扰产生的虚警。 相似文献
682.
为保证结构的安全性和耐久性,宜对结构早期的损伤情况进行健康监测.采用电阻抗方法和人工神经网络技术对钢制薄梁进行了损伤识别的实验研究,但将测得的电阻抗信号都作为神经网络的输入参数则显得不切实际,所以采用主成分分析的降维方法进行实验数据的预处理,降维后包含着最重要主成分的电阻抗信号代替原始数据将作为神经网络的输入参数.研究表明:采用该技术得到的仿真结果与实验观察非常吻合. 相似文献
683.
张文渊 《广东微量元素科学》2002,9(11):61-63
随着人类社会的进步,经济的发展,生活水平的提高,环境的优劣逐步成为人们越来越关心的问题。自然环境的优劣,会直接影响人体的健康。自然环境的物质中所含常量元素和微量元素对维持人类生命,保护人体健康起到了一定的基础作用。 相似文献
684.
M.P. Sammartino F. Bellanti M. Castrucci D. Ruiu G. Visco T. Zoccarato 《Microchemical Journal》2008,88(2):201-209
The increasing human and animal use and abuse of drugs as well as of personal health care and gross domestic products, involve disposal and waste problems and, as a consequence, affect the environmental condition. Actually most of the active principles are complex synthesised organic molecules that react, inside human or animal body, by specific biochemical reactions that in no case can reach a 100% yield and produce residues that could be more noxious of the starting compounds. Just reading the indication sheet accompanying any drugs, it is easy to state that no drug can be considered healthy, so, their use constitutes a serious pollution source. The full awareness of this relatively new environmental problem let many researchers to face it from different point of view. Current studies are considering the sources of these substances in the environment, the effects on human health as well as on the flora and fauna species, the recalcitrance and possible degradation methods, analytical techniques able to determine them and their metabolites even at low concentrations and in complex matrices.Literature on the subject continuously increases and a comparison of all data became more and more difficult both for a single drug and for different ones based on the same or different active principles. This is a typical case in which chemometrics can extract a full information in the easier way, so the design of a European database coupled to suitable expert system software should be strongly suggested. 相似文献
685.
686.
Two supply delivery systems in a hospital are compared. In order to evaluate the number of carriers required by the new system, an operational research model has been developed and solved by the tabu search method. The results indicate that the new system is better except on weekend days.This work has been achieved while the second author was visiting the Université de Montréal. 相似文献
687.
This paper is focused on the problem of locating preventive health care facilities. The aim is to maximize participation to prevention programs. We assume that distance is a major determinant of participation and people would go to the closest facility for preventive health care. Each facility is required to have more than a predetermined number of clients because of the direct relationship between volume and quality of preventive services. We provide a mathematical formulation and present alternative solution approaches for this new location problem. We report on computational performance of the proposed methods in locating public health centers in Fulton County, Georgia and mammography screening centers in Montreal, Quebec. 相似文献
688.
W. G> Shin D. Y. H. Pui H. Fissan S. Neumann A. Trampe 《Journal of nanoparticle research》2007,9(1):61-69
TSI Nanoparticle Surface Area Monitor (NSAM) Model 3550 has been developed to measure the nanoparticle surface area deposited
in different regions of the human lung. It makes use of an adjustable ion trap voltage to match the total surface area of
particles, which are below 100 nm, deposited in tracheobronchial (TB) or alveolar (A) regions of the human lung. In this paper,
calibration factors of NSAM were experimentally determined for particles of different materials. Tests were performed using
monodisperse (Ag agglomerates and NaCl, 7–100 nm) and polydisperse particles (Ag agglomerates, number count mean diameter
below 50 nm). Experimental data show that the currents in NSAM have a linear relation with a function of the total deposited
nanoparticle surface area for the different compartments of the lung. No significant dependency of the calibration factors
on particle materials and morphology was observed. Monodisperse nanoparticles in the size range where the response function
is in the desirable range can be used for calibration. Calibration factors of monodisperse and polydisperse Ag particle agglomerates
are in good agreement with each other, which indicates that polydisperse nanoparticles can be used to determine calibration
factors. Using a CFD computer code (Fluent) numerical simulations of fluid flow and particle trajectories inside NSAM were
performed to estimate response function of NSAM for different ion trap voltages. The numerical simulation results agreed well
with experimental results. 相似文献
689.
John T. Blake Ken McTaggart Donna Killeen 《European Journal of Operational Research》2018,264(3):884-893
For patients suffering from a blood related disease, a stem cell transplant represents the best, and sometimes the only, possible treatment. Registries have been created throughout the world to match patients with stem cell donors. Canada's adult registry, OneMatch, was formed to meet the needs of Canadian patients. However, only 20–30 percent of unrelated adult stem cell transplants in Canada are sourced from Canadian donors. Self-sufficiency has proven difficult for OneMatch, in part, because the Canadian registry is dwarfed by other international registries with similar donor populations.In this paper, we present a study to evaluate changes the Canadian registry designed to promote ethnic diversity while meeting the needs of the Canadian patient population. We formulate the composition problem as a linear optimization model and solve it using a combination of exact and heuristic methods for a registry of 1 M donors.We conclude that when registry size is constrained, there are advantages to increasing ethnic diversity over self-sufficiency. However, results show that some communities cannot be easily accommodated within an adult registry of a fixed size. Thus, our results highlight the need for stem cells derived from cord blood for hard to match populations. 相似文献
690.
探讨了养老保险基金收支监测预警系统的关键技术问题,提出系统的设计框架和功能模块设计方法。系统的实施有利于开展养老保险基金的非现场监督,有利于提高监督工作质量和水平,对完善社会保险基金监管体系具有重要意义。 相似文献