Minimum power assignment in wireless ad hoc networks with spanner property

Power assignment for wireless ad hoc networks is to assign a power for each wireless node such that the induced communication graph has some required properties. Recently research efforts have focused on finding the minimum power assignment to guarantee the connectivity or fault-tolerance of the network. In this paper, we study a new problem of finding the power assignment such that the induced communication graph is a spanner for the original communication graph when all nodes have the maximum power. Here, a spanner means that the length of the shortest path in the induced communication graph is at most a constant times of the length of the shortest path in the original communication graph. Polynomial time algorithm is given to minimize the maximum assigned power with spanner property. The algorithm also works for any other property that can be tested in polynomial time and is monotone. We then give a polynomial time approximation method to minimize the total transmission radius of all nodes. Finally, we propose two heuristics and conduct extensive simulations to study their performance when we aim to minimize the total assigned power of all nodes. The author is partially supported by NSF CCR-0311174.     

TOT项目融资中国有资产转让定价的博弈分析

本文以TOT项目融资方式为对象,运用博弈的方法,从合理分配国有资产经营期内增值收入的角度出发,得出这样的结论,在国有资产转让过程中,政府与私营资本之间的谈判是一系列复杂的博弈过程,在博弈中政府的最优行为是对国有资产转让进行招标,同时给予某一招标企业一定的中标优先权,这样政府能够较现行的国有资产转让方式获得更多的收益.     

GM Foods and the Misperception of Risk Perception

Public opposition to genetically modified (GM) food and crops is widely interpreted as the result of the public's misperception of the risks. With scientific assessment pointing to no unique risks from GM crops and foods, a strategy of accurate risk communication from trusted sources has been advocated. This is based on the assumption that the benefits of GM crops and foods are self-evident. Informed by the interpretation of some qualitative interviews with lay people, we use data from the Eurobarometer survey on biotechnology to explore the hypothesis that it is not so much the perception of risks as the absence of benefits that is the basis of the widespread rejection of GM foods and crops by the European public. Some respondents perceive both risks and benefits, and may be trading off these attributes along the lines of a rational choice model. However, for others, one attribute-benefit-appears to dominate their judgments: the lexicographic heuristic. For these respondents, their perception of risk is of limited importance in the formation of attitudes toward GM food and crops. The implication is that the absence of perceived benefits from GM foods and crops calls into question the relevance of risk communication strategies for bringing about change in public opinion.     

基于iCARE理论的《大学英语》课程定位研究与教改实践

《大学英语》是高校一门重要的公共基础课,厘清课程性质是推进教学改革的基础。在梳理不同时期《大学英语》教学大纲有关规定,借鉴国外高校现代语言课程定位基础上,提出《大学英语》课程定位是EGP,提高"交互密度"是保证学习效率和效果的关键。河北科技大学在多年教改实践基础上,创建了iCARE教学理论,并从六个方面推进《大学英语》课程改革,形成具有校本特色的《大学英语》教学模式,取得良好教改成效。     

齐《诗》“五际”说新探

在西汉今文三家《诗》中,齐《诗》最能反映汉代诗学的特征。这种特征主要表现在阴阳五行思想对诗学的影响,其代表性思想就是齐《诗》的“五际”说。“五际”说与律历、性情等思想有着密切关系,其具体内容应该指仁、义、礼、智、信“五性”,这与《诗纬》中的“四始五际”说是不同的。二者虽然都运用了阴阳五行学说,但侧重不同:齐《诗》“五际”说的根据主要是阴阳说,《诗纬》“五际”说的基础则主要是五行说。     

共生理论视域下我国融合教育发展的困境与反思

作为一种全新的教育理念,融合教育自提出以后很快成为国际特殊教育的发展趋势。当前,我国融合教育在取得巨大进步的同时,在融合主体的接纳态度与行动支持、教师专业能力与合作意识、融合课程与教学、融合资源投入与共享等方面仍然面临困境。基于共生理论视角对融合教育困境进行理论反思,提出构建融合共生的社会文化环境、建立教师专业学习社群、调整课程与教学、完善资源配置等建议,以期为推进融合教育、提升融合教育质量提供借鉴。     

唐代诗学对唐代南岳佛教诗歌创作的影响

南岳佛教诗歌创作从南朝时期开始,创作尚处于发韧期,到了唐代,终于迎来了异彩纷呈的时刻。同时唐代也是中国古代诗歌创作的高峰,诗歌创作的高峰往往会带来诗歌品评和理论总结的高峰,唐代诗学有着风骨和情韵并重的审美取向,诗学发展可以分为“载道”一路和“取境”一路。此外,近体诗对声韵的营造也承接了魏晋南北朝以来对格律的探究。文章结合这些诗论,采用演绎法,从一般到特殊,从普遍到个别地将唐代南岳佛教诗词的艺术特点做出较为准确的分析。     

荀子礼乐美学中的交往论思想探析

荀子从建构“群居和一”的交往共同体出发阐释其礼乐美学思想,礼、乐、诗作为共同体整合的文化资源而被其赋予“先王之道”的价值权威。情性的约束规范是荀子礼乐美学交往论内涵的中心话题,他倡导“情文具尽”的交往,追求礼义与情性的平衡美和礼义所建构的秩序美。荀子深入阐释乐的交往和合审美内涵,强化“乐”对君子品格美的培养。《诗》承载着礼的价值观念和信仰体系,具有深刻的交往意义。荀子礼乐美学中的交往论思想具有明显的经世致用性。     

具身认知理论下的幼儿德育工作

传统幼儿德育认知是“离身”的,表现为忽视身体的重要性。基于具身认知理论重建幼儿德育理论使幼儿德育认知具有具身性,幼儿德育知识具有情境性,幼儿德育行为具有生成性。由家长、教师、幼儿园与社区构成的合作性支持系统通过个性化问题的制定与指导,跨园协作与全方位合力设计学习空间等路径使幼儿德育工作优化并高效。     

基于累积前景理论的多资产投资组合优化与实证研究

基于CPT视角的多风险资产投资组合模型,探讨投资者面对不同投资风险时的心理变化以及心理变化对其投资策略的影响。通过选取不同超额收益率及波动率水平的股票,测试投资策略对于风险态度指标的敏感度。研究表明,投资者面对不同风险具有明显地心理变化,并且其心理变化对投资策略具有显著的影响。具体表现在几个方面：投资者面对不确定收益时,表现出风险厌恶,面对不确定损失时,表现出风险偏好;投资者将无风险资产的投资收益作为心理参考点,所做的投资决策与相对于此参考点的相对财富水平的变化有关,而不是与传统理论中的绝对财富变化量相关。