Least squares Hermitian solution of the complex matrix equation AXB+CXD=E with the least norm

In this paper, a new method is presented to solve the least squares Hermitian problem of the complex matrix equation AXB+CXD=E. The explicit expression of least squares Hermitian solution with the least norm is given. The least squares Hermitian solution with the least norm of complex matrix equation AXB=E is also derived. Numerical algorithms and numerical examples show the feasibility of our method.     

Some properties of submatrices in a solution to the matrix equation AXB=C with applications

Suppose that AXB=C is a consistent matrix equation and partition its solution X into a 2×2 block form. In this article we give some formulas for the maximal and minimal ranks of the submatrices in a solution X to AXB=C. From these formulas, we derive necessary and sufficient conditions for the submatrices to be zero and nonsingular, respectively. As applications, we give a group of formulas for the maximal and minimal ranks of submatrices in generalized inverses of matrices and their properties.     

可持续发展与区域生态环境建设

<正> 一、关于可持续发展问题 可持续发展问题提出已经有很长时间,但全世界到现在也还没有很好地解决。10年前虽提出了可持续发展,但没有什么时候比现在更需要宣传和实施可持续发展,因为脆弱的生态环境现在还没有明显改变。中国的环境和生态问题也非常严峻。最近中科院分析小组做了一些分析后,感觉在今后25年到半个世纪,这种形势不容乐观,主要问题是我们的人均资源     

Some Properties of Matrices with 1, -1 and 0 Entries

A class of matrices with 1, -1 and 0 entries, called the H-matrices, is introduced and properties of such matrices are investigated. It is shown that for an H-matrix K the matrix G = KDK^T, where D is a diagonal matrix with nonnegative diagonal entries, has certain properties applicable to topological synthesis of networks. A technique for decomposing a particular symmetrical matrix G, called the Q-matrix, into KDK^T, where K is an H-matrix and D is a diagonal matrix with positive diagonal entries, is also developed.     

阿拉善盟肉苁蓉产品供给服务评估

为协调阿拉善盟梭梭林资源保护和人工接种肉苁蓉产业开发的矛盾,兼顾当地野生肉苁蓉产品的＂产出能力＂和百姓的＂获取难易＂两个因素,构建了基于GIS的野生肉苁蓉产品供给服务及价值的空间表达评估技术框架。研究结果表明：2008年,阿盟野生肉苁蓉供给服务总量为503.05t/a,仅为理论总产出量的3.66%;供给服务总价值达0.25亿元;赛汉陶来苏木、东风镇、乌力吉苏木和吉兰泰镇能够最为方便的获得最多的野生肉苁蓉产品,建议有条件的开展人工接种肉苁蓉的开发利用;而阿拉腾敖包和达来呼布镇大部分梭梭林受当地百姓采挖肉苁蓉的影响较弱,开发与保护的矛盾不明显,建议有条件的进行梭梭林围栏封育。     

基于经济-环境-社会协调发展的绿色创新绩效评价——以环渤海经济带为例

面对资源环境问题给经济社会的可持续发展所带来的瓶颈与短板,绿色创新成为衡量一个国家和地区持续竞争优势的重要标志。基于经济-环境-社会(EES)协调发展的理念,在明确绿色创新内涵和价值维度的基础上,将绿色创新绩效分解为经济绩效、环境绩效和社会绩效,并运用投影寻踪模型和协调发展度模型,以环渤海经济带为例进行绩效评价,进而分析绿色创新水平的区域差异及各维度的协调发展程度。为进一步提高绿色创新绩效提供理论与实践参考。     

Application of the G/G-expansion method for nonlinear diffusion equations with nonlinear source

The generalized diffusion equations, with nonlinear source terms which encompasses the Fisher, Newell-Whitehead, FitzHugh-Nagumo and Allen-Cahn equations as particular forms are solved by the G^′/G-expansion method. The exact solutions are in terms of hyperbolic, trigonometric and rational functions with external parameters. This paper concludes with the stationary topological soliton solution of the FitzHugh-Nagumo equation that is obtained by the Ansatz method.     

建立环境安全是实现可持续发展的基础——中国环境科学学会2002年学术年会会议总结暨专家建议

<正> 一、会议概况与主题 中国环境科学学会2002年学术年会于12月10-11日在北京召开。清华紫光环保股份有限公司、福建丰泉环保集团有限公司、北京科技大学、北京蟹岛绿色生态度假村有限公司等单位协办了本届年会。全国人大、全国政协、国家环境保护总局和国务院有关部门的领导和专家,环境界的两院院士,各有关高等院校和科研单位的学者,省、市环保部门和环境学会的负责人,全国优秀环境科技企业家代表,港、台环保企业及社会团体代表等,四百多人出席了大会。     

提高国土资源对可持续发展保障能力(摘要)

适应加入WTO后我国国土资源管理面临的新形势、新任务、新要求,核心是要提高国土资源对经济社会可持续发展的保障.为此,要努力满足经济社会发展对土地、矿产和海洋资源的需求,为实现第三步战略目标做好必要的资源准备;要努力推进国土资源要素市体系的培育和规范,优化国土资源配置,依法维护国土资源利用秩序和资源所有者、使用者的合法权益;要努力深化改革,建立完善国土资源管理体制、机制、法制,全面提高国土资源调查、规划、管理、保护与合理利用水平.     

Effective top-k computation with term-proximity support

Modern web search engines are expected to return the top-k results efficiently. Although many dynamic index pruning strategies have been proposed for efficient top-k computation, most of them are prone to ignoring some especially important factors in ranking functions, such as term-proximity (the distance relationship between query terms in a document). In our recent work [Zhu, M., Shi, S., Li, M., & Wen, J. (2007). Effective top-k computation in retrieving structured documents with term-proximity support. In Proceedings of 16th CIKM conference (pp. 771–780)], we demonstrated that, when term-proximity is incorporated into ranking functions, most existing index structures and top-k strategies become quite inefficient. To solve this problem, we built the inverted index based on web page structure and proposed the query processing strategies accordingly. The experimental results indicate that the proposed index structures and query processing strategies significantly improve the top-k efficiency. In this paper, we study the possibility of adopting additional techniques to further improve top-k computation efficiency. We propose a Proximity-Probe Heuristic to make our top-k algorithms more efficient. We also test the efficiency of our approaches on various settings (linear or non-linear ranking functions, exact or approximate top-k processing, etc.).     

科技期刊编辑继续教育现状中存在的问题及解决措施

【目的】 全面梳理科技期刊编辑继续教育工作的现状,解决继续教育中存在的问题,提高科技期刊编辑的素质。【方法】 分析科技期刊编辑继续教育的现状,阐述科技期刊编辑继续教育的内涵、目标与必要性、原则和形式,从受教者和施教者两方面分析了科技期刊编辑参加继续教育遇到的问题。【结果】 受教者要从思想认识、时间安排、资金来源等方面提高认识,克服困难参加继续教育;施教者应当建立合理的继续教育培训制度,健全继续教育评价体系,开展灵活多样的教育模式,营造浓厚的继续教育气氛。【结论】 科技期刊编辑的继续教育工作对编辑整体素质的提高有极大的促进作用。     

技术系统演化与相应的知识演化理论综述 /FONT /P

本文以技术创新演化进程为切入点,沿技术系统的线性与非线性演化过程对知识管理的内在要求、知识管理领域的研究对促进技术演化的支持这一路径,按各研究内在的机理一致性对技术系统演化与相应的知识演化理论进行了梳理。结合各个子领域自身的文献综述,可以使技术创新和知识管理领域研究者和管理者对整个技术创新管理及相应知识管理的研究脉络有清明地认识,从而就具体的研究对理论体系及企业R&D实践的支持作用等达成全局性的了解。     

Patrick Geddes and the politics of evolution

Ever since they began to be widely discussed during the early nineteenth century, evolutionary ideas have played a controversial role in debates about politics and social reform. Understanding the political commitments of those who have sought to integrate politics and evolution is a complex challenge, though; not least because memories of mid-twentieth-century eugenic policies have frequently shaped how we talk about biosocial science. However, as the case of the Scottish biologist-turned-town-planner Patrick Geddes highlights, while we need to be aware of the broad appeal that biosocial science has historically held, we also need to recognise that current political categories can be misleading when thinking about those of who have put evolution and politics together.     

青年编辑继续教育培训创新探索与实践

【目的】 探索有效的科技期刊青年编辑继续教育培训措施和形式,更好地服务于青年编辑职业发展。【方法】 调研青年编辑培训需求,分析总结国内外继续教育培训形式,在此基础上探索适合青年编辑的继续教育培训,遴选跨科技期刊界、跨编辑界的教员队伍,融合青年编辑发展、科技期刊办刊实践、新媒体操作等内容。【结果】 通过问卷调查进行评估,跨界融合的继续教育培训形式得到参训学员认可,达到预期效果。【结论】 科技期刊编辑继续教育培训应系列化、持续化,可在此次培训基础上延续开展,帮助青年编辑构建知识体系。     

The eyes and skin of Octopus: compensating for sensory deficiencies

Octopuses are the chameleons of the sea and can change their appearance to an extraordinary degree. Yet recent experiments, described here, show that they are almost certainly colour-blind. They blend in with their background primarily because of their neurally-controlled chromatophores, which, regulated by information from an eye sensitive to brightness, constitute a system for matching luminance. Deeper in the skin, however, there is a system of broad-band reflectors (the leucophores and iridophores). When the overlying chromatophores retract, these will automatically reflect incident light, whatever its wavelength.     

Dimensions as Virtual Items: Improving the predictive ability of top-N recommender systems

Traditionally, recommender systems for the web deal with applications that have two dimensions, users and items. Based on access data that relate these dimensions, a recommendation model can be built and used to identify a set of N items that will be of interest to a certain user. In this paper we propose a multidimensional approach, called DaVI (Dimensions as Virtual Items), that consists in inserting contextual and background information as new user–item pairs. The main advantage of this approach is that it can be applied in combination with several existing two-dimensional recommendation algorithms. To evaluate its effectiveness, we used the DaVI approach with two different top-N recommender algorithms, Item-based Collaborative Filtering and Association Rules based, and ran an extensive set of experiments in three different real world data sets. In addition, we have also compared our approach to the previously introduced combined reduction and weight post-filtering approaches. The empirical results strongly indicate that our approach enables the application of existing two-dimensional recommendation algorithms in multidimensional data, exploiting the useful information of these data to improve the predictive ability of top-N recommender systems.     

媒介融合背景下学术期刊编辑双元性继续教育机制研究

【目的】 探究媒介融合背景下提升学术期刊编辑双元性继续教育效果的方式。【方法】 以理论分析为主,审视学术期刊编辑继续教育的现存问题,分析双元性学习理论对编辑继续教育的适用性,并构建媒介融合背景下学术期刊编辑的双元性继续教育机制。【结果】 结合媒介融合时代特征,学术期刊编辑的双元性继续教育机制能系统地规划和配置资源,在兼顾期刊部门及编辑个体2个层面的基础上开展探索式学习和利用式学习。双元性继续教育机制的影响体系包括外部拉动力、外部推动力、内部支撑力及内部制约力4个维度,且从学术期刊、领导团队、编辑群体3 个角度提出了该机制的运行保障措施。【结论】 媒介融合背景下学术期刊编辑的双元性继续教育机制具有辩证性和动态性,在系统规划和有效配置资源的基础上,实现从学习视角提升编辑的继续教育效果。