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首先讨论了易的对称原理和物理学的发展。其次探索易与现代科学的关系,并提出有不同层的三维空间太极图。第三研究易学的某些可能应用。第四探讨易与分形、混沌等的关系,由九宫八卦五行图可得分维D=1.8927…,最后讨论易理和社会可持续发展的数理模型,并得到价值(J)-动力(L)-模式(M)-代价(D)-调控(K)五行生克模型。 相似文献
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前分布式数据库查询优化器基于代价模型,总代价=CPU代价＋I／O代价＋通信代价,在远程通信网或数据传输率较低的系统中,通信代价应作为首要的优化目标来考虑。文章提出了一种基于Multi—Agent技术的查询模型（QMAS）,同时为了保证系统组内、组间Agent之间的高效通信,采用了树型拓扑结构（TrMAS）的通信模型,系统内各Agent使用通信原语高效通信、协作,且满足Agent间的通信路由最优,从而保证了QMAS的查询效率。 相似文献
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彭文灵 《赣南师范学院学报》2004,25(3):40-43
SITAR(ScalableIntrusion-TolerantArchitecture)容侵系统模型是由美国DARPA支持的一项研究计划,它的目标是保护COTS(Commercial-Of-The-Shelf)服务器,但该模型投票监视器在投票/裁决之前需要进行结果的复杂转换,才能决定结果的发布者,造成系统的代价较高.文章将分组码的特性应用到SITAR容侵模型的投票机制中去,讨论有效避免在SITAR模型中投票监视器在投票/裁决之前需进行结果的复杂转换的方法. 相似文献
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代价问题是个古老的话题,但代价观,在代价与创价(收益)之间如何作决策,却是现代话题。20世纪70年代后,一个重要的思想──可持续发展观发展起来,那是因为人们认识到,可持续发展需要有效地抑制代价。所以,我们可以把可持续发展观与代价观看成是人类关注自身健康发展的同一问题的两个方面。代价与代价观什么是代价代价是日常生活中常用的字眼《。汉语大辞典》(1986)这样解释代价的含义:其一为“购物的钱款”;其二“泛指为达到某种目的所消耗的物质、精力,或所做出的牺牲。”代价一词最先使用于人们的经济生活中。经济学的一个经典性的原理是:… 相似文献
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加速寿命试验(ALT)是用加大试验应力来缩短试验周期的一种基本寿命试验方法,其目的在于:以较低的试验代价(例如试验样本、试验周期等)获取具有足够精度的寿命信息.序降应力加速寿命试验是一种更高效的加速寿命试验方法.该文利用积累失效模型,得出了序降应力加速寿命试验在对数正态分布场合的时间折算公式和分布函数. 相似文献
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以母语为维吾尔语,第二语言为汉语的熟练和非熟练维一汉双语者为被试,采用词汇判断研究任务,通过探讨维一汉双语者维吾尔语和汉语两种语言之间的语码切换代价和代价对称与否来揭示其切换机制。结果发现：（1）熟练双语者和非熟练双语者,维吾尔语和汉语均出现了切换代价;（2）两种语言的切换代价是否存在显著性差异,取决于汉语的熟练程度,对于熟练双语者而言,切换至两种熟练语言的代价相当;对于非熟练双语者而言,切换至非熟练语言汉语的代价显著大于切换至熟练语言维吾尔语的代价,表现了切换代价的不对称性现象;（3）维-汉双语者的语码切换代价及代价的不对称性源于两种语言的激活与竞争,支持了抑制说．可以用双语交互激活模型来解释。 相似文献
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应用层多播(ALM)作为IP多播的替代在互联网中得到广泛的应用。提出一个新的基于优先级的动态分层应用层多播模型CDMP(The Classified Dynamic Model Based on the Priority in Application-Level Multicast),模型通过对不同性质的结点的分层来搭建整个架构,通过分域将性质接近的结点放在一起以保证数据传输的效率和数据共享的公正性,并且减少了结点寻找路由的代价,加快了当结点失败时的路由修复速度。通过分析和仿真实验证明,CDMP协议具有良好的上述性质。 相似文献
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分析了信息安全存在的相互依存性,在着重研究主体间成本代价及安全损失的期望得益基础上,将主体的策略选择分为“投入安全成本”和“不投入安全成本”,根据得益矩阵建立起两个及多个主体选择安全成本代价的博弈模型,该模型使用纳什均衡分析为主体成本代价投入提供决策支持。针对这种情形,在确定如何运用信息安全成本投入来完善自身安全的同时,研究网络环境中主体间成本代价的联系,提出运用博弈论中的均衡来将选择投入信息安全成本的主体间的各个要素进行量化,转换为一个相对的多人博弈形式,从而得到信息安全成本投入问题的理论方法,有效的实现有限成本代价下的风险最小化。 相似文献
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杨枫 《福建工程学院学报》2011,9(1)
在研究代建制取费构成的基础上,建立代建管理费取费模型,并与其他不同代建管理取费模型进行对比分析,认为代建费包括调整的建设单位管理费、税金、利润、履约保函费用、预备费、可行性研究报告编制费、招标代理费,其中后两项按实际发生情况计算.最后,将新构建的代建费标准与其他标准进行了计算对比分析,表明本模型更适合福建本地实际情况. 相似文献
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Child maltreatment incurs a high lifetime cost per victim and creates a substantial US population economic burden. This study aimed to use the most recent data and recommended methods to update previous (2008) estimates of 1) the per-victim lifetime cost, and 2) the annual US population economic burden of child maltreatment. Three ways to update the previous estimates were identified: 1) apply value per statistical life methodology to value child maltreatment mortality, 2) apply monetized quality-adjusted life years methodology to value child maltreatment morbidity, and 3) apply updated estimates of the exposed population. As with the previous estimates, the updated estimates used the societal cost perspective and lifetime horizon, but also accounted for victim and community intangible costs. Updated methods increased the estimated nonfatal child maltreatment per-victim lifetime cost from $210,012 (2010 USD) to $830,928 (2015 USD) and increased the fatal per-victim cost from $1.3 to $16.6 million. The estimated US population economic burden of child maltreatment based on 2015 substantiated incident cases (482,000 nonfatal and 1670 fatal victims) was $428 billion, representing lifetime costs incurred annually. Using estimated incidence of investigated annual incident cases (2,368,000 nonfatal and 1670 fatal victims), the estimated economic burden was $2 trillion. Accounting for victim and community intangible costs increased the estimated cost of child maltreatment considerably compared to previous estimates. The economic burden of child maltreatment is substantial and might off-set the cost of evidence-based interventions that reduce child maltreatment incidence. 相似文献
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The effects of geographic variations in cost of living and family income on children’s academic achievement and social competence in first grade (mean age = 86.9 months) were examined, mediated through material hardship, parental investments, family stress, and school resources. Using data from the Early Childhood Longitudinal Study–Kindergarten Cohort (N = 17,565), higher cost of living was associated with lower academic achievement. For poor children only, higher cost of living was also detrimental to parental investments and school resources. Parental investments and school resources were more strongly associated with achievement for lower income than higher income children. Results suggest that cost of living intersects with income in meaningful ways for family and child well‐being and should be accounted for in the poverty measure. 相似文献
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Concerns about the influence of students’ perceived negative consequences of engagement in a task (i.e., cost) on their emotions, motivation, and cognition have increased in the last decade. The use of longitudinal models is needed to provide new insights into the role of perceived cost in mathematics learning. Grounded in the control-value theory, this study examined cross-lagged relations of mathematics anxiety, perceived cost, and mathematics achievement. The participants (N = 335) reported their mathematics anxiety and perceived cost four times during Grades 7 and 8, and their mathematics grades were attained from their school records. Cross-lagged panel model analysis revealed evidence of a long-term positive reciprocal relationship between mathematics anxiety and effort/emotional cost, a gradually diminished relationship between effort/emotional cost and mathematics performance, and a positive achievement to anxiety link during the transition between grade levels. Moreover, mathematics performance is a distal predictor of mathematics anxiety through effort/emotional cost rather than a proximal predictor or an outcome of anxiety. This study also clarified the distinction in the central role of effort/emotional versus opportunity cost in the interrelatedness of mathematics anxiety and performance, where the latter failed to demonstrate significant paths. Specific timing for interventions was discerned. Early cost prevention interventions along with considerations of academic achievement to alleviate both anxiety and perceived effort/emotional are highlighted as crucial for a positive high school mathematics experience. 相似文献
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It has been shown that the anterior cingulate cortex (ACC) and its dopamine system are crucial for decision making that requires physical/emotional effort, but not for all forms of cost–benefit decision making. Previous studies had mostly employed behavioral tasks with two competing cost–reward options that were preset by the experimenters. However, few studies have been conducted using scenarios in which the subjects have full control over the energy/time expenditure required to obtain a proportional reward. Here, we assessed the roles of the ACC and its dopamine system in cost–benefit decision making by utilizing a “do more get more” (DMGM) task and a time–reward trade-off (TRTO) task, wherein the animals were able to self-determine how much effort or time to expend at a nosepoke operandum for a proportional reward. Our results showed that (1) ACC inactivation severely impaired DMGM task performance, with a reduction in the rate of correct responses and a decrease in the effort expended, but did not affect the TRTO task; and (2) blocking ACC D2 receptors had no impact on DMGM task performance in the baseline cost–benefit scenario, but it significantly reduced the attempts to invest increased effort for a large reward when the benefit–cost ratio was reduced by half. In contrast, blocking ACC D1 receptors had no effect on DMGM task performance. These findings suggest that the ACC is required for self-paced effort-based but not for time–reward trade-off decision making. Furthermore, ACC dopamine D2 but not D1 receptors are involved in DMGM decision making. 相似文献
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研究生人均培养成本实证研究--以复旦大学为例 总被引：5，自引：1，他引：5
林荣日 《清华大学教育研究》2004,25(5):60-67
定量测算研究生人均培养成本和高校固定资产总值，是教育经济学研究的两大难点。本文运用《教育经济学》的最新研究成果及其相关理论和方法，在大量实地调查的基础上，较为科学地测算出了2003年复旦大学研究生人均年度培养成本、人均教学成本、人均科研成本和固定资产总值。其结果如下：(1)博士研究生的人均年度培养成本、人均年度教学成本和人均年度科研成本分别为41413．18元、6269．62元和35143．56元；(2)硕士研究生的人均年度培养成本、人均年度教学成本和人均年度科研成本分别为35630．79元、10150．80元和25479．99元；(3)复旦大学固定资产总值为9510829029元；(4)复旦大学固定资产折旧成本和固定资产潜在租金总值为760866322．3元。 相似文献
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彭朝林 《深圳职业技术学院学报》2004,3(1):54-57
本介绍了深圳高新技术企业实施成本领先战略的必要性和四大优势——优惠税收、资金支持、研发投入、人力和土地资源优势，并深入分析了深圳高新技术企业如何通过供应链管理和生产技术与流程创新两大关键环节实现持久的成本领先优势。 相似文献
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研究生个人教育成本的实证研究 总被引：1，自引：0，他引：1
自上世纪80年代初以来，国内已有不少学定量测算了大学生个人直接教育成本和间接教育成本，但对研究生个人直接教育成本和间接教育成本的定量研究，似乎较为少见。本运用教育经济学的有关理论和方法，定量测算了2003年复旦大学研究生个人直接成本和间接成本。其结果为：(1)对于统招和定向培养的研究生而言，其个人年度直接教育成本为2114．92元，其个人年度间接教育成本为35857．48元，个人年度直接教育成本和间接教育成本之和为37972．4元；(2)对于自费和委培研究生而言，其个人年度直接教育成本为10768．49元，个人年度间接教育成本为35857．48元，个人年度直接教育成本和间接教育成本之和为46625．97元。 相似文献
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将FAHP方法结合工程实例,在风险识别的基础上,运用层次分析法构造工程项目施工阶段成本风险系统层次模型,确定权重系数。应用模糊数学方法进行该阶段成本风险模糊综合评价,明确系统总风险度,并对风险因素予以重要性排序,找出影响工程项目施工阶段的主要成本风险因素。 相似文献