如何提高招标阶段工程造价咨询的工作质量

随着《建设工程工程量清单计价规范》(GB 50500—2008)的实施,项目招标阶段工程造价咨询工作质量的高低直接影响招标投标的成败及工程造价的合理控制。文章从实践的角度对如何提高招标阶段工程造价咨询工作质量作简要分析,借此总结经验,供同业参考。     

物流线性规划问题的MATLAB求解

对线性规划问题的图解法、单纯形解法,以及MATLAB的函数linprog求解方法进行了对比分析,并结合实例,采用linprog函数对产销平衡和产销不平衡的两类物流运输问题进行了求解。     

基于PROTEUS的单片机对步进电机运动控制仿真

针对步进电机在各领域上越来越广泛的应用,提出了用单片机AT89C51控制运行四相步进电机方法。由于实验室里进行设计,受到场地、仪器和元件等的限制,提出了用Proteus进行仿真的方法。该软件不仅具有其它EDA工具软件的仿真功能,还能仿真单片机及外围器件。它是目前最好的仿真单片机及外围器件的工具,使设计时间大为缩短,学校的资源得以非常好的利用。     

How effective are heuristic solutions for electricity planning in developing countries

Heuristic algorithms have been widely used to provide computationally feasible means of exploring the cost effective balance between grid versus off grid sources for universal electrification in developing countries. By definition in such algorithms however, global optimality is not guaranteed. We present a computationally intensive but globally optimal mixed integer non-linear programming (MINLP) model for electricity planning and use it in a Monte Carlo simulation procedure to test the relative performance of a widely used heuristic algorithm due to [28]. We show that the overall difference in cost is typically small suggesting that the heuristic algorithm is generally cost effective in many situations. However we find that the relative performance of the heuristic algorithm deteriorates with increasing degree of spatial dispersion of unelectrified settlements, as well as increasing spatial remoteness of the settlements from the grid network, suggesting that the effectiveness of the heuristic algorithm is context specific. Further, we find that allocation of off grid sources in the heuristic algorithm solution is often significantly greater than in the MINLP model suggesting that heuristic methods can overstate the role of off-grid solutions in certain situations.     

行为导向教学法在空气调节技术课程教学中的运用

文章初步探讨了在中等职业学校制冷与空调专业空气调节技术课程中运用行为导向教学法的必要性、可行性,并结合实例阐述了行为导向教学法实施过程及在教学中应注意的问题.     

电机生产计划计算机优化系统

本文介绍了电机生产计划计算机优化系统.该系统主要由模型优化和数据处理两大部分组成,采用结构化方法进行系统分析与设计.该系统解决了合理、充分地利用有限原材料的问题,为工厂制订更合理、更科学的生产计划提供了必要的信息。     

关于非线性规划的灵敏度分析

本文简要介绍非线性规划灵敏度分析的发展概况和最主要结果。     

Probabilistic Bounds on the Virtual Multipliers in Data Envelopment Analysis: Polyhedral Cone Constraints

The paper is concerned with the incorporation of polyhedral cone constraints on the virtual multipliers in DEA. The incorporation of probabilistic bounds on the virtual multipliers based upon a stochastic benchmark vector is demonstrated. The suggested approach involves a stochastic (chance constrained) programming model with multipliers constrained to the cone spanned by confidence intervals for the components of the stochastic benchmark vector at varying probability levels. Consider a polyhedral assurance region based upon bounded pairwise ratios between multipliers. It is shown that in general it is never possible to identify a center-vector defined as a vector in the interior of the cone with identical angles to all extreme rays spanning the cone. Smooth cones are suggested if an asymmetric variation in the set of feasible relative prices is to be avoided.