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41.
42.
W D Tiner 《International Journal of Project Management》1985,3(1):13-18
In order to control a project, construction management requires project information. This is obtained through accounting, estimating, cost management and scheduling functions which produce project reports. These reports are best obtained by subdividing the project into small parts. The ways in which each of these functions subdivides a project in order to produce its reports is discussed, together with a means of interrelating this information with a technique known as the work breakdown structure. 相似文献
43.
We propose in this paper a self-organized monitoring architecture for mobile ad-hoc networks based on a selective scheme where
subsets of nodes are managed. These nodes are determined based on their network behavior in order to favor subsets of well-connected
nodes. The key idea is to relax the requirements of the management plane, and to use these manageable subsets to monitor the
performance of the overall network. We therefore propose a new performance metric to be monitored, in order to estimate the
capability of ad-hoc nodes to communicate end-to-end in the network. Extensive simulations show how different parameters affect
this metric. 相似文献
44.
The paper considers a generalized discrete‐time order‐replacement model for a single unit system, which is subject to random failure when in operation. Two types of discrete randomized lead times are considered for a spare unit; one is for regular (preventive) order and another is for expedited (emergency) order. The model is formulated based on the discounted cost criterion. The underlying two‐dimensional optimization problem is reduced to a simple one‐dimensional one and then the optimal ordering policy for the spare unit is characterized under two extreme conditions: (i) unlimited inventory time and (ii) zero inventory time for the spare unit. A numerical example is used to determine the optimal spare‐ordering policy numerically and to examine the sensitivity of the model parameters. 相似文献
45.
46.
47.
杨怀义 《数字社区&智能家居》2006,(14)
网格袋布局管理器是java布局中最有用、最灵活、最复杂、最难掌握的一种布局管理器,实际上,如果我们明白了在布局时它利用了单元格相对坐标定位这一点,以及各个约束条件在布局中的作用,网格袋布局也会变得很轻松。 相似文献
48.
电源对介质阻挡放电(DBD)激发准分子(XeCl*)辐射的影响 总被引:3,自引:2,他引:1
本文对电源参数如电压幅值、频率及正负电压对介质阻挡放电激发准分子XeCl 紫外 (30 8nm)辐射的影响进行了实验研究。结果表明 ,UV辐射随电压幅度的增加而增强 ,但效率下降 ;提高频率 ,增加了放电次数 ,导致UV辐射的增强 ;此外 ,在较高的频率下 ,电压上升沿变陡 ,使得电子获得的能量主要用于原子的激发和电离。正、负电压放电的不对称源于电极结构的不对称而引起的放电过程的差异 ,负电压内电极可向放电管中馈入更多的能量 ;比较发光光谱可判断生成准分子的等离子体化学过程没有明显的差别 相似文献
49.
讨论了现代企业的过程观经及企业过程的构成,提出了企业生产经营全过程的作业管理思想,并对全过程作业管理的基本内容进行了探讨,分析了企业过程重组和优化的驱动因素、目标和实现途径,最后概述了全过程作业管理的支撑技术。 相似文献
50.
Waters in the Great Lakes basin contain more than 400 contaminant chemicals that potentially affect fishery resources, commerce, and human inhabitants. We determined in the laboratory the effects of selected contaminants on the toxicity of the widely used lampricides TFM (3-trifluoromethyl-4-nitrophenol) and Bayer 73 (2′,5-dichloro-4′-nitrosalicylanilide) to three species of fish—rainbow trout (Salmo gairdneri), white sucker (Catostomus commersoni), and fathead minnow (Pimephales promelas). The fish were exposed to paired mixtures of lampricides and selected contaminants in standardized, acute static toxicity tests to determine the resulting type of response—less than additive, additive, or greater than additive (synergistic). As expected, the toxicities of combinations of lampricides with organic pesticides, metal, industrial or municipal pollutants, and tannic acid were mostly additive. However, the toxicity of a combination of TFM, Delnav, and malathion was synergistic, and extremely small quantities of each chemical became lethal when mixed. The concentration that produced 50% mortality was 1.64 mg/L for TFM alone but only 0.041 mg/L for TFM with the pesticides. Toxicities of the pesticides in the combination also increased commensurately. The triple combination of chemicals produced extraordinary synergism and effectively demonstrated the hazards that may result if certain chemical combinations occur in the aquatic environment. However, synergism is not the only kind of toxic action that produces hazards to aquatic organisms. All three types of toxic action are of concern because toxic units produced by contaminant chemicals add to the toxic units of applied management chemicals. Since the toxicity of the majority of chemical combinations is simply additive, this cumulative toxic action contributes more total units to aquatic environments than the extreme actions of less than additive and synergism. The toxicity of the lampricide TFM, as well as other management chemicals, is reinforced by the presence of any contaminant that contributes additional units of toxicity. Therefore, all types of cumulative toxic action should be of concern to people and agencies involved with protecting the environment. 相似文献