教育媒体与技术在机械制图课程教学中的优化运用

为了获得良好的教学效果,提高教育教学质量,关键是如何实现教育媒体与技术在课程教学中的优化运用。文章在调查研究和理论分析的基础上,建立了基于教育媒体与技术的优化教学模型,重点介绍了教育媒体与技术在机械制图课程教学中优化运用的一些做法和经验。     

Older Drivers Retiring From the Road: An Application of the Selection,Optimization, and Compensation Model

Purpose: This study uses the selection, optimization, and compensation (SOC) model to compare older adults who have given up driving, those who still drive, and those who drive less to identify differences in the three groups. Design and Methods: This cross-sectional study of 281 older adults is part of the Naturally Occurring Retirement Community Demonstration Project. Study participants completed interviews that included questions on demographics, health and functioning, mental health, social support, and current levels of engagement in activities including current driving status. Results: Data suggest that driving retirement is a process and that a substantial number of people are in the transitional stage, where they are less functional than those who still drive and more similar to those who have retired from the road. Implications: Given the similarity of those who drive less to those who have given up driving, front-line professionals and policy makers must work together to ease the transition to driving retirement for those without adequate ability to effectively compensate for their inability to continue to drive safely.     

计算气井储量新方法

提出了采用弹性二相法结合物质平衡方程作为计算全井储量的新方法。弹性二相法主要用于气藏开发进入拟稳态以后，要求压力和产量的测量精确，气藏的工作制度对弹性二相法储量也有很大影响，其计算可靠程度已被矿场实际证实；物质平衡方程在开发初期计算精度不高。将弹性二相法与物质平衡法结合建立多目标优化函数，该方法既能很好地应用弹性二相法，又能体现物质平衡，使得该方法适用范围更广，计算结果更可靠，对致密气藏具有更好的推广应用价值。通过实例气井动态储量进行的验证对比表明，该方法在理论上是合理的，实际验证是可行的。     

利用专门用途英语理论（ESP）进行高职英语课程改革

大学生是祖国的未来，为国家培养宝贵人才是每个教师的重任。在我国教育改革的洪流下。一线教师应充分掌握和利用先进的教学方法和教学资源。作者盼望通过本文能够与广大教育教学工作者们进行学术交流．为国家培养更多、更优秀的人才。     

多心理账户下的群体投资决策规则优化研究

从决策者有限理性角度,引入行为金融于群体投资决策系统,研究了多心理账户下群体投资决策规则优化问题。研究给出了群体投资决策系统诸多非标准金融实证异象行为的金融解释,并指出了决策者金字塔式心理账户结构;研究提出了各个心理账户下离散随机变量的信息度量方法,以行为证券组合理论为内核进行集成建模,揭示了多心理账户下群体投资决策规则的优化机理。     

An environmental life cycle optimization model for the European pulp and paper industry

Will paper recycling reduce the environmental impact of the European pulp and paper sector? If so, is maximal paper recycling the best policy to optimize the life cycle of the pulp and paper sector? We explore these questions using an approach that combines materials accounting methods and optimization techniques. Environmental impact data are inputs for a linear programming network flow model to find optimal configurations for the sector. These configurations consist of a mix of different pulping technologies, a geographical distribution of pulp and paper production, and a level of recycling consistent with the lowest environmental impacts. We use the model to analyse scenarios with different recycling strategies. Recycling offers a reduction in environmental impact in regions with a high population and a large production of paper and board products. Regions with a large production of graphic products should focus on cleaner virgin pulp production with energy recovery. We conclude that relocation of paper production also offers a reduction in environmental impact. However, the severe effects on the economy make this policy less attractive than a combination of recycling, cleaner pulp production and energy recovery.     

论政府生态规制的制度优化

生态市场由于产权不安全或不存在、外部性与公共性等原因失灵,需要政府生态规制的介入,以求提高生态市场的运行效率。但现实情况是,作为一个公共产权机构,政府的生态规制运行机制也常常出现失灵。因此,应针对政府生态规制失灵的主要原因,探讨其优化的制度安排,包括强化对生态规制者的规制、建立公共租金消散机制、放松生态规制和优化生态规制。     

On Approximability of Boolean Formula Minimization

For a Boolean function given by a Boolean formula (or a binary circuit) S we discuss the problem of building a Boolean formula (binary circuit) of minimal size, which computes the function g equivalent to , or -equivalent to , i.e., . In this paper we prove that if P NP then this problem can not be approximated with a good approximation ratio by a polynomial time algorithm.     

On Combinatorial Approximation of Covering 0-1 Integer Programs and Partial Set Cover

The problems dealt with in this paper are generalizations of the set cover problem, min{cx | Ax b, x {0,1}ⁿ}, where c Q₊ⁿ, A {0,1}^{m × n}, b 1. The covering 0-1 integer program is the one, in this formulation, with arbitrary nonnegative entries of A and b, while the partial set cover problem requires only m–K constrains (or more) in Ax b to be satisfied when integer K is additionall specified. While many approximation algorithms have been recently developed for these problems and their special cases, using computationally rather expensive (albeit polynomial) LP-rounding (or SDP-rounding), we present a more efficient purely combinatorial algorithm and investigate its approximation capability for them. It will be shown that, when compared with the best performance known today and obtained by rounding methods, although its performance comes short in some special cases, it is at least equally good in general, extends for partial vertex cover, and improves for weighted multicover, partial set cover, and further generalizations.     

Batch-Processing Scheduling with Setup Times

The problem is to minimize the total weighted completion time on a single batch-processing machine with setup times. The machine can process a batch of at most B jobs at one time, and the processing time of a batch is given by the longest processing time among the jobs in the batch. The setup time of a batch is given by the largest setup time among the jobs in the batch. This batch-processing problem reduces to the ordinary uni-processor scheduling problem when B = 1. In this paper we focus on the extreme case of B = +, i.e. a batch can contain any number of jobs. We present in this paper a polynomial-time approximation algorithm for the problem with a performance guarantee of 2. We further show that a special case of the problem can be solved in polynomial time.