基于综合活动敏感性的动态缓冲分配及监控方法

经典缓冲管理方法只考虑了活动对工期的敏感性,而成本对项目的影响也至关重要,而且两者对不同项目的影响也各不相同。考虑活动对成本的敏感性,确定出活动对时间和成本的综合敏感性系数,在此基础上,根据活动对成本和时间的综合敏感性和活动持续时间,将项目缓冲进行分配,使得缓冲的分配更加合理。根据综合活动敏感性将活动分为高、一般以及低敏感性活动,从而能够更加有效地确定项目的监控重点。分别设置监控触发点,对缓冲消耗实行动态监控。最后,结合案例,采用Matlab仿真模拟验证优化结果。实验结果表明,该方法使缓冲利用更加高效,突出监控重点,能够实现成本降低和工期缩短的双重目标。

基于活动敏感性的动态缓冲监控方法研究

缓冲监控问题对于企业成功应用关键性项目管理,提高项目进度管理绩效和确保项目按时完工,都至关重要。本文针对现有缓冲监控方法在项目进度监控中所存在的忽视内部情况的问题,引入项目进度风险分析方法中的活动敏感性信息。研究了动态环境下活动敏感性指标的计算和监控阀值的设定,在缓冲的黄区监控中集成了考虑活动敏感信息的动态监控过程。在综合考虑缓冲指标和活动关联度指标的监控指标体系,综合设置各指标的监控阀值的基础上,提出了基于活动敏感性信息的关键链动态缓冲监控方法。最后通过一个算例将所提方法与现有方法进行比较,实验结果表明,合理设置活动关联度的监控阀值后,所提方法在总赶工时间、总赶工活动数、超计划完工次数以及监控负荷这四个绩效方面的结果更优。

基于Monte Carlo方法的PERT网络关键路线和最关键活动分析

在定义计划评审技术(program evaluation and review technique,PERT)网络局部关键活动、关键活动、关键路线和活动关键度的基础上,提出了关键活动、关键路线的分析方法;根据活动不确定性对项目计划工期影响的大小,即活动敏感性指标的大小,确定活动在项目进度控制中的重要程度;在定义活动相对敏感性、活动敏感性的基础上,利用全概率公式,得到活动敏感性指标计算公式,进而提出了最关键活动分析方法。算例表明,利用本研究提出的方法可便捷地找出PERT网络的关键路线和最关键活动。

Effects of Abnormal Early Rearing Environments on Fear Memory in Adult Rats

In the present experiment, Pavlovian fear conditioning was adopted to study the effects of different early rearing environments on fear conditioning in adult rats. Weaned rats were reared in three manipulable environments （enriched, social and isolated conditions）. After 8 weeks, fear conditioning （characterized by percentage of freezing） was observed and analyzed, and rats＇ weight, locomoter activity and foot-shock sensitivity were operated too. The results showed that： （1） Compared with control group, the level of conditioned fear was significantly increased in enriched group, but significantly decreased in isolated group; （2） Enriched and isolated conditions influenced rat＇s weight significantly; （3） Different rearing conditions have no effect on locomoter activity and foot-shock sensitivity. These results indicated that early enriched condition could improve the tone-evoked fear conditioning response, while isolated condition impaired the response.

Financial Valuation of Segment-Specific Marketing Activities and Market Segment Development

By applying methods of investment appraisal, this paper offers a financial approach for determining the optimal level of segment-specific marketing activities and market development under the conditions of imperfect markets and uncertainty. Within the scope of marketing planning and controlling, the model is suited to optimizing an enterprise＇s market activities and taking interdependencies between market segments, production, and investments into account. Applying duality theory of linear programming allows for identifying the income determinants and deriving formulas for a correct valuation by using （corrected） net present values （NPVs）. Under certain conditions, they can also be used to easily evaluate and financially interpret the effects of parameter changes. The author uses sensitivity analysis to support these findings and to obtain more information on the effects of these determinants.

Preparation and characterization of pH-sensitive calcium carbonate-chlorin e6 nanoparticles for photodynamic therapy

In the present study,we combined CaCO_(3)NPs and Ce6 to construct CaCO_(3)-Ce6 nanoparticles (NPs).CaCO_(3)-Ce6 NPs were characterized in terms of particle size,zeta potential,UV-Vis absorption spectrum,fluorescence spectrum,FTIR spectrum,and pH-responsive behavior.The reactive oxygen species (ROS) generation in vitro was measured in 4T1 cells.The results showed that CaCO_(3)-Ce6 NPs were uniform-sized NPs with excellent fluorescence properties and pH-responsive behavior.The ability of ROS generation by CaCO_(3)-Ce6 NPs was stronger compared with Ce6 in 4T1 cells because Ca;could enhance the ROS generation,which could contribute to a stronger anti-tumor effect.

Delimitation of Urban Growth Boundary Based on the Coordination of Ecology and Residential Activity Spaces: A Case Study of Jinan, China

Delimitation of an urban growth boundary(UGB)can effectively curb disorderly urban expansion,optimize urban development space and protect the ecological environment.Eco-environmental sensitivity was evaluated and areas prohibiting construction expansion were extracted by establishing an index system.Point of interest(POI)and microblog data were utilized to analyze the expansion of residential activity space.Urban space expansion potential was calculated using a comprehensive evaluation model,and an urban growth boundary for Jinan in 2020 was delimited combining the predicted urban expansion scale.The results showed that:(1)An evaluation of eco-environmental sensitivity can effectively protect ecological land and provide an ecological basis for urban expansion.Regions with high eco-environmental sensitivities in Jinan are located along the banks of the Yellow River and Xiaoqing River and in southeast mountainous areas,but eco-environmental sensitivities in the central,north and southeast areas are relatively low;(2)The model to evaluate urban residential activity expansion can quantify the spatial distribution of urban residents’activities.Regions with high potential for residential activity space expansion in Jinan are mainly concentrated in the middle of Jinan and most are part of existing built-up areas and surrounding areas;(3)The method that delimits urban growth boundaries based on the coordination of ecology and residential activity space is reasonable.Spatial expansion in Jinan mainly extends towards the east and west wings,and the boundary conforms to the spatial strategy guiding Jinan’s development and is consistent with the overall layout in related plans.Considering both ecological protection and the internal forces driving urban expansion,the method of urban growth boundary delimitation used in this study can provide a reference and practical help for studies and management of urban development in the new era.