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1.
产业升级的路径由其比较优势演化路径所决定,而产品空间结构能够反映并影响一个国家或地区比较优势、核心竞争力等经济元素的变化。为了明确产业升级的方向路径,文章基于Hausmann等学者提出的产品空间与比较优势演化理论,结合江苏省装备制造业的发展,构建了显示性比较优势、产品邻近度、产品空间密度等指标,深入研究了产品空间结构对比较优势的影响。研究发现,产品邻近度、产品空间密度等指标都能够对显示性比较优势产生影响,即产品空间结构的变化会促使比较优势发生改变,这为确定产业升级方向路径提供了新的视角。最后,文章根据江苏省装备制造业的产品空间结构的状况,提出了如何改变产品空间结构以促进比较优势演化进而实现产业升级的对策建议。 相似文献
2.
城市空间结构是城市可持续发展治理及规划的重要抓手。如何科学认识新时期城市空间结构是深化城市认知并进行人与自然和谐调控的基础。文章简要回顾传统城市空间结构理论的时代背景,通过对新时期技术革命、政策和社会经济环境的分析,指出城市空间结构在组织原则、组织方式、优化目标及要素成分方面的变革性转向,阐明传统理论用于解释新时代城市治理的局限性。提出从人地地域系统理论出发重构城市空间结构研究范式、重新认识城市空间结构载体空间、强化城市空间结构关系解析,以及革新城市空间结构测度体系等新时代认识路径。未来应对城市空间结构认知方面挑战的关键举措,即重构城市空间结构理论、集成城市空间结构解析关键技术、融合应用多源数据、建设城市空间结构优化调控的数字孪生平台。 相似文献
3.
城市管理方法的变革与发展趋势 总被引：1，自引：0，他引：1
城市空间结构的变化和要素的重新组合,对传统的城市管理方法提出变革要求。现代城市管理中,系统性倾向、运控重心变化、管理流程的改变、主体多元化、城市管理手段和方法的变革,越来越多的影响着城市管理者的思维理念和行为方式。重新审视传统城市管理方法缺陷,吸收和适应新方法、新理念和新手段,对提升我国城市管理的成效至关重要。 相似文献
4.
高校众创空间作为高校创新创业人才培养的新兴重要载体,对高校创新创业教育具有重大作用。在创新驱动发展战略背景下,各高校结合自身优势对众创空间建设模式进行了各具特色的实践探索,但在理论研究方面仍缺乏科学梳理和系统思维,在空间布局和功能定位上,缺乏从生态系统的视角打造高校创新创业生态系统。本文通过阐释众创空间的内涵,分析高校众创空间的存在问题,在高校创新创业教育的实践经验基础上,探索以生态位理论视角剖析众创空间的系统结构模型以及要素互动关系,提出高校众创空间生态系统构建的建设策略,全面提升高校众创空间的科学发展。 相似文献
5.
国家旅游示范基地是新阶段促进旅游业转型升级,推动国家精品旅游目的地体系建立,推进全域旅游示范区建设的一项基础性工作。本文结合新阶段旅游目的地转型升级的发展定位、发展要素、市场依托、空间布局、产业构成和管理运营六方面的趋势,系统分析了国家旅游示范基地的基本概念、内涵特征、要素构成,探讨了国家旅游示范基地选建涉及到的空间导向与科学基础、基地 “依托区”与“核心区”的关系处理、基地的准入标准与监测评估体系联动、基地的推广建设与国家全域旅游区推进协同、基地创建中利益主体政府与市场关系定位等基础理论问题,研究对指导国家旅游示范基地的规划建设和具体创建,推进国家旅游目的地转型升级具有重要的理论价值和现实意义。 相似文献
6.
R. Saeks 《Journal of The Franklin Institute》1976,302(4):331-355
In some recent work Kailath and Duttweiler used reproducing Kernel Hilbert space techniques, together with a highly non-standard time structure, to formulate a representation theory for stochastic processes. Although non-standard their structure satisfied the axioms for a resolution space; a Hilbert space to which a time structure is axiomatically adjoined which has received considerable interest in the mathematical system theory literature.In the present paper the work of Kailath and Duttweiler is extended via the concept of a reproducing kernel resolution space which is defined for the covariance of an arbitrary resolution space valued random variable. Applications to the representation and approximation of stochastic processes are considered, a new formula for the optimal stochastic predictor is derived, and a canonical form for the causal factors of an arbitrary covariance is obtained. 相似文献
7.
通过对褐铁矿化（铁帽）中Cu、Pb、Zn等元素活动相态（即水溶相、吸附相、碳酸盐相、铁锰氧化物相）的测定,比较主要成矿元素相态空间变化规律,元素各相态变化时与成矿元素总量的关系,从而研究相态变化时对成矿与否的指示意义,以及相态变化对成矿中心的预测.本文通过顺序提取法对成矿元素各个相态逐一研究,结合前人成果从而寻求一种寻找成矿矿床的新的思路.此外与以往不同,本论文采用的样品为初碎样品,主要测试样品表面成矿元素在各个相态中的含量,而非测试全岩含量,意在寻找一种通过表面残余相态成矿元素含量及规律来判断成矿与否以及成矿中心的新思路. 相似文献
8.
牵引空间战略与中国的产业空间结构重组 总被引：7，自引：0，他引：7
在全球经济一体化背景下，全球产业正以全球价值链的新形式重新进行空间组织。在新的空间体系中，牵引空间具有战略意义。因此，增强牵引空间竞争力并构建空间体系成为指导新经济条件下产业布局优化的一种新思路。依据牵引空间理论，中国的宏观经济空间应当规划为五大空间结构体系，未来的产业布局应当以此战略为指导进行优化。 相似文献
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10.
近年来,以微博为代表的新媒体发展非常迅速,传播速度非常快,社会影响力巨大。本文运用系统研究方法将微博看成一个传播系统,从传播学的角度分析微博系统的基本结构要素,揭示各传播要素的结构及特点,以期更好的认识和利用微博,为建设社会主义文化强国和实现中国梦的伟大理想服务。 相似文献
11.
建立较为完整的航天项目进度风险评价体系,该体系由5个方面,21个元素,89个指标构成,涉及航天项目的设计、生产、测试等诸多过程;利用基于模糊一致矩阵的模糊层次分析法(FAHP)建立算法模型,将结果的一致性检验与修正过程整合为非线性规划问题,并通过粒子群算法(PSO)进行优化求解,得到满足一致性要求的权重结果,并根据结果排序识别出航天项目进度管理中的重要工序,提高事前管理的效率,以便更好地进行工程项目进度管理。最后以载人航天工程X项目为例,证明该方法的合理性与可行性。 相似文献
12.
《Information processing & management》2005,41(2):275-288
Many information retrieval systems use the inverted file as indexing structure. The inverted file, however, requires inefficient reorganization when new documents are to be added to an existing collection. Most studies suggest dealing with this problem by sparing free space in an inverted file for incremental updates. In this paper, we propose a run-time statistics-based approach to allocate the spare space. This approach estimates the space requirements in an inverted file using only a little most recent statistical data on space usage and document update request rate. For best indexing speed and space efficiency, the amount of the spare space to be allocated is determined by adaptively balancing the trade-offs between reorganization reduction and space utilization. Experiment results show that the proposed space-sparing approach significantly avoids reorganization in updating an inverted file, and in the meantime, unused free space can be well controlled such that the file access speed is not affected. 相似文献
13.
《Information processing & management》2022,59(4):102949
This paper proposes a new method for semi-supervised clustering of data that only contains pairwise relational information. Specifically, our method simultaneously learns two similarity matrices in feature space and label space, in which similarity matrix in feature space learned by adopting adaptive neighbor strategy while another one obtained through tactful label propagation approach. Moreover, the above two learned matrices explore the local structure (i.e., learned from feature space) and global structure (i.e., learned from label space) of data respectively. Furthermore, most of the existing clustering methods do not fully consider the graph structure, they can not achieve the optimal clustering performance. Therefore, our method forcibly divides the data into c clusters by adding a low rank restriction on the graphical Laplacian matrix. Finally, a restriction of alignment between two similarity matrices is imposed and all items are combined into a unified framework, and an iterative optimization strategy is leveraged to solve the proposed model. Experiments in practical data show that our method has achieved brilliant performance compared with some other state-of-the-art methods. 相似文献
14.
《Information processing & management》2005,41(2):243-264
Existing ranking schemes assume all term occurrences in a given document are of equal influence. Intuitively, terms occurring in some places should have a greater influence than those elsewhere. An occurrence in an abstract may be more important than an occurrence in the body text. Although this observation is not new, there remains the issue of finding good weights for each structure.Vector space, probability, and Okapi BM25 ranking are extended to include structure weighting. Weights are then selected for the TREC WSJ collection using a genetic algorithm. The learned weights are then tested on an evaluation set of queries. Structure weighted vector space inner product and structure weighted probabilistic retrieval show an about 5% improvement in mean average precision over their unstructured counterparts. Structure weighted BM25 shows nearly no improvement. Analysis suggests BM25 cannot be improved using structure weighting. 相似文献
15.
众创空间作为开放式创新生态系统,具有多主体、多要素、多功能的特点,需要依托行之有效的评价指标体系推动技术创新培育、监督规范管理行为、优化众创空间效率,为产学研深度融合提供有力支撑。目前,以战略生态位管理理论为核心的众创空间管理评价体系仍有待完善,特别是在众创空间的具体功能定位差异、成员准入规则设计、创业要素互构作用、评价指标建模细节等均缺乏实证探析。结合技术创新发展的自身特点,立足调研数据,通过对众创空间主体、客体及环境等要素的梳理,着重挑选与分析和众创空间功能发挥息息相关的预期、网络、学习、市场培育与市场保护因素,运用德尔菲法确定各项指标权重,应用多层次模糊综合评定法阶梯式递进评价,构建完善"投入-产出"三形态两阶段模型,并以广东省众创空间为实例检验评价效果。结论证明,通过加强创业前景规划、规范空间运行、优化革新技术服务、优化市场孵化服务、增强创业市场产出,可有效提升众创空间的实际运行效能。 相似文献
16.
技术集成能力是衡量企业资源配置水平,影响企业集成创新效果的内生动力,其形成方式与成长过程一直是理论界的研究热点。本文借鉴企业基因理论,从仿生学视角剖析技术集成能力基因本质,运用实证方法探究技术集成能力基因碱基的具体表达方式,在此基础上构建技术集成能力基因结构模型,揭示其成长“黑箱”。研究表明,技术集成能力基因是由技术链和管理链构成的双螺旋结构,信息监测、组织柔性、系统整合和技术学习是技术集成能力基因碱基要素的具体表现形式,也是技术集成能力成长的驱动要素。技术集成能力基因通过复制、变异和重组的一系列进化过程,实现要素匹配和功能优化,完成能力的适应性演化,提高企业资源配置效率。本文旨在为基因结构模型研究由概念性构建向实证识别提供全新思路和研究框架。 相似文献
17.
Francoeur E 《Endeavour》2002,26(4):127-131
In the mid-1960s, a group of scientists at Massachusetts Institute of Technology, led by Cyrus Levinthal, took hold of one of the early interactive graphics terminals and used it to visualize, study and model the structure of proteins and nucleic acids. From this encounter between cutting-edge computer technology and molecular biology emerged the crucial elements for the development of a research-technology field known today as interactive molecular graphics. The following account is not only about how computer graphics technology has literally changed the way scientists view the molecular realm, but also a look at how an epistemic and institutional space was created to integrate this technology into scientific research. 相似文献
18.
分布式创新已经成为企业应对经济全球化及知识经济挑战的新型创新模式,中国企业整合全球创新资源的技术创新国际化面临的"分布式创新黑箱"问题亟待解决。本文通过分析国内外分布式创新理论研究现状及其不足,解构了企业分布式创新三个要素维度:分布式结构、分布式认知及分布式协同,并构建了其与知识共享和创新绩效关系的理论模型及相应的假设;通过大样本的问卷调查对所提出的理论假设进行了统计验证分析,证明上述三要素通过三种知识共享机制对企业创新绩效有显著影响;最后,针对实证结果探讨了我国企业实施分布式创新知识共享的相应管理措施。 相似文献
19.
科研活动需要图书馆学科馆员团队知识整合能力的支持.结合学科馆员团队知识整合的特征,搭建了基于科研活动的图书馆学科馆员团队知识整合平台结构模型,并详细说明了诸要素相互作用机理,揭示了图书馆学科馆员团队知识整合运作的中介过程,指出图书馆学科馆员团队为科研活动服务绩效提供一个新方法、新思维. 相似文献
20.
《Information processing & management》2023,60(3):103248
In a dynamic retrieval system, documents must be ingested as they arrive, and be immediately findable by queries. Our purpose in this paper is to describe an index structure and processing regime that accommodates that requirement for immediate access, seeking to make the ingestion process as streamlined as possible, while at the same time seeking to make the growing index as small as possible, and seeking to make term-based querying via the index as efficient as possible. We describe a new compression operation and a novel approach to extensible lists which together facilitate that triple goal. In particular, the structure we describe provides incremental document-level indexing using as little as two bytes per posting and only a small amount more for word-level indexing; provides fast document insertion; supports immediate and continuous queryability; provides support for fast conjunctive queries and similarity score-based ranked queries; and facilitates fast conversion of the dynamic index to a “normal” static compressed inverted index structure. Measurement of our new mechanism confirms that in-memory dynamic document-level indexes for collections into the gigabyte range can be constructed at a rate of two gigabytes/minute using a typical server architecture, that multi-term conjunctive Boolean queries can be resolved in just a few milliseconds each on average even while new documents are being concurrently ingested, and that the net memory space required for all of the required data structures amounts to an average of as little as two bytes per stored posting, less than half the space required by the best previous mechanism. 相似文献