简单多数票法和Borda法的防策略性分析

利用数学模型对简单多数票法和Borda法的策略投票问题进行了探讨.首先针对简单多数票法,研究了两个候选人分别在三种得票关系情况下的操纵性问题,得到并证明了简单多数票法投票的防操纵条件,计算并证明了简单多数票法出现策略性投票的概率;然后分析了Borda法的防策略性,得到并证明了Borda法投票的防策略性条件定理,然后根据该定理以三个候选人为例分析Borda法的操纵性问题,并得到了两个推论.指出使用Borda法投票时可能出现操纵性的两种情况,并对这两种情况下Borda法的可操纵性予以证明.

多值性社会选择函数防策略性分析

研究了多值社会选择函数的防策略性,介绍了多值社会选择函数的防策略性定义,对其在严格偏好情况下的性质进行了研究分析.证明了在严格偏好情况下,多值社会选择函数满足防策略性时,一定满足一致性,且选择结果是一个常量.

路上的半厌恶型设施选址博弈的机制设计

研究了路上的半厌恶型设施选址博弈问题.所谓的半厌恶是指参与者对设施的偏好不完全相同,一些参与者喜欢设施,而另一些参与者厌恶设施.针对参与者出于自身利益可能谎报位置和偏好的情形,设计了一种相对于最优社会福利的具有小性能比的团防策略性机制.分别给出了性能比为3的确定型团防策略性机制和性能比为2的随机型团防策略性机制.

Optimal quasi-periodic maintenance policies for two-unit series system

To investigate the effects of various random factors on the preventive maintenance （PM） decision-making of one type of two-unit series system, an optimal quasi-periodic PM policy is introduced. Assume that PM is perfect for unit 1 and only mechanical service for unit 2 in the model. PM activity is randomly performed according to a dynamic PM plan distributed in each implementation period. A replacement is determined based on the competing results of unplanned and planned replacements. The unplanned replacement is trigged by a catastrophic failure of unit 2, and the planned replacement is executed when the PM number reaches the threshold N. Through modeling and analysis, a solution algorithm for an optimal implementation period and the PM number is given, and optimal process and parametric sensitivity are provided by a numerical example. Results show that the implementation period should be decreased as soon as possible under the condition of meeting the needs of practice, which can increase mean operating time and decrease the long-run cost rate.

设施选址博弈问题的无支付机制设计研究

选址博弈是目前国际相关学术领域的重要前沿课题之一.在选址博弈问题中,存在n个相互影响的"理性"居民,他们的住址等信息是其私有信息;设计者需要设计选址机制,以居民汇报的住址信息为输入,输出设施位置.在进行机制设计的过程中,如何在没有金钱的刺激下,保证所有居民"说真话",设计出防策略性无支付机制是其中的重要研究内容.设施选址博弈问题的无支付机制设计是组合优化和理论计算机科学的交叉学科课题,在管理科学、信息科学以及社会经济学等领域有着重要的应用,具有重要的理论意义和实际的应用价值.现根据不同设施类型及个数、不同个人偏好、不同度量空间以及不同社会总体目标等条件,介绍各种类型的设施选址博弈模型,罗列相关的研究成果,并总结其中尚待解决的问题.

Exploring the Recent Anti-China Backlash in Australia and Its Impact

The year 2017 marked not only the 45th anniversary of the establishment of China-Australia diplomatic relations,but also significant turbulence in the relationship.While bilateral economic and trade relations,as well as people-to-people communication and cooperation continue to grow,a series of dramatic and negative events unfolded in Australia,advocating the so-called"China threat",and instigated by anti-China sentiments.The recent anti-China backlash in Australia was caused by a combination of deep structural change in the current international system,and instability in Australia’s domestic politics.It is also the outcome of Australia’s dependence on the US-Australia alliance,while balancing between its own economic and security interests.It is worth noting that in comparison to the past,the current anti-China movement in Australia has been more profound and more focused,demonstrating new characteristics.This includes Australia collaborating with certain Western nations against China’s influence,as well as strategic warnings with more political and policy implications.Although Australia’s anti-China backlash will not have a fundamental impact on China-Australia relations,Australia’s anti-China stance and behavior is characteristic of an increasingly prevalent trend among the Western nations of concern about China’s rising influence,and new defense strategies against this.China must proceed with caution when dealing with the negative repercussions of this.

Research on Preventive Maintenance Strategy of Simulator Based on Reliability Theory

Based on the theory of reliability, this paper studies the preventive maintenance strategy of the simulator with incomplete maintenance, and establishes the preventive maintenance model with the aim of simulating the maintenance cost and simulating machine availability. The main contents of this paper are as follows： Firstly, this paper introduces the background and significance of this paper, expatiates the relevant concepts and mathematical foundation of simulator maintenance related theory and reliability maintenance thought, simulator performance degradation law, Weibull parameter estimation method, As the center of the maintenance （RCM） theory of system maintenance decision analysis.

Contrast induced nephropathy after percutaneous coronary intervention： risk factors and preventive strategy

Objective To analyze the risk factors and clinical outcome of contrast induced nephropathy （CIN） in patients with coronary artery disease （CAD） after percutaneous coronary intervention （PCI） and discuss its prevention. Methods Fifty-four patients with C1N among 729 patients who received PCI were retrospectively studied and the related risk factors, cardiovascular events and preventive strategy were analyzed. Results C1N was strongly associated with pre-procedure chronic renal failure, diabetes mellitus and large-dose contrast. The incidence of cardiac mortality and major adverse cardiac events 1 year after PCI in CIN group was higher than that in group without CIN. Conclusion Chronic renal failure, diabetes mellitus and dosage of contrast agent were three independent risk factors of CIN. CIN could affect the patients＇ prognosis. A well overall perioperative management of CAD patients following PCI, especially hydration therapy, is the most important strategy for prevention of CIN.

Tallow tree allocates contrasting secondary chemicals in response to varying environments along elevational gradients

Aims Understanding how tree species regulate multiple types of secondary chemicals along elevational gradients is critical for elucidating the physiological and ecological strategies of plants in response to varying biotic and/or abiotic environments.This study aims to examine how Chinese tallow tree(Triadica sebifera)allocates resources to the production of different secondary chemicals in response to varying environments across elevational gradients.Methods We conducted field surveys of different herbivore feeding guilds and their damage rates on Chinese tallow trees along an elevational gradient in China and measured secondary chemicals(tannins and flavonoids)in damaged and undamaged leaves.Important Findings The odds of a leaf being damaged(chewing or scarring)decreased with elevation.Flavonoid concentrations increased with elevation in undamaged leaves but decreased with elevation in damaged leaves,with quercitrin contributing most strongly to this pattern,likely as results of plant responding to changing biotic or abiotic stresses along elevational gradients.Tannin concentrations did not vary with elevation,so undamaged leaves had relatively lower tannin to flavonoid ratios at high elevation than at low elevation.Our study reveals variation in herbivory and contrasting trends in plant secondary metabolism along an elevation gradient and highlights the importance of simultaneously considering multiple types of secondary chemicals in plant physiological and ecological strategies.