共查询到20条相似文献，搜索用时 15 毫秒
1.
我校的科研管理工作已经在科研经费、科研成果、知识产权等方面取得了较大成绩，在此基础上进一步提出了科研管理工作必须实行创新管理的新思路。介绍了我校科研工作创新管理在政策观念、制度措施、完善内部管理措施和建立科研信息管理系统等方面的新举措。 相似文献
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Adrian-Gabriel Chifu Florentina Hristea Josiane Mothe Marius Popescu 《Information processing & management》2015
Word sense ambiguity has been identified as a cause of poor precision in information retrieval (IR) systems. Word sense disambiguation and discrimination methods have been defined to help systems choose which documents should be retrieved in relation to an ambiguous query. However, the only approaches that show a genuine benefit for word sense discrimination or disambiguation in IR are generally supervised ones. In this paper we propose a new unsupervised method that uses word sense discrimination in IR. The method we develop is based on spectral clustering and reorders an initially retrieved document list by boosting documents that are semantically similar to the target query. For several TREC ad hoc collections we show that our method is useful in the case of queries which contain ambiguous terms. We are interested in improving the level of precision after 5, 10 and 30 retrieved documents (P@5, P@10, P@30) respectively. We show that precision can be improved by 8% above current state-of-the-art baselines. We also focus on poor performing queries. 相似文献
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《Journal of The Franklin Institute》2022,359(16):9296-9312
A novel space shift keying (SSK) multiple–input multiple–output (MIMO) technique based on Steiner triple system is proposed and analyzed in this article. SSK attracted considerable research interest in the past few years driven by the several promised inherent advantages including low error probability, low computational complexity and a very simple hardware implementation with very low cost and power consumption. Yet, the spectral efficiency of SSK increases with a base two logarithm of the number of transmit antennas and high data rates are only viable with a massive and impractical number of transmit antennas. Alternatively, generalized SSK (GSSK) scheme is considered, where a combination of antennas is activated at each time instant. GSSK promises the use of arbitrary number of transmit antennas not necessarily a power of two integer. Also, GSSK can attain high data rate with low number of transmit antennas at the cost of substantial degradation in the error performance. In this study, a Steiner triple system is utilized to propose a tailored SSK scheme with substantial reduction in the required number of transmit antennas, without compromising the error probability. It is shown that the proposed Steiner–SSK (S–SSK) MIMO system achieves almost identical error performance to a conventional SSK system but with nearly 90% reduction in the number of transmit antennas. As well, the average bit error rate (ABER) of S–SSK is shown to outperform GSSK by at least 3dB. It is also reported that a S–SSK system accomplishes significant reduction in hardware cost, power consumption, and computational complexity as compared to conventional SSK scheme. Yet, GSSK is shown to marginally outperforms S–SSK in these metrics as it requires smaller number of transmit antennas per a target spectral efficiency. 相似文献
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Broadband power line communication (BPLC) is a promising solution to satisfy the growing data rate demands for broadband indoor communication networks. However, the BPLC transmission power spectral density (PSD) is restricted in the very high frequency (VHF) band to avoid harmful interference to the existing wireless services. In this paper, a new hybrid system is proposed utilizing BPLC and cognitive radio over TV white space (TVWS) to enhance the system capacity over BPLC in VHF, forming a VHF TVWS BPLC multiple-input multiple-output (MIMO) system. An iterative precoding algorithm is proposed to satisfy the interference limit at the TV primary user (PU) receiver (Rx) and enhance the ergodic capacity. Moreover, a power allocation algorithm is developed for the MIMO system to achieve the maximum ergodic capacity subject to the average total power constraint and limit of interference to TV PU. Simulation results demonstrate the significant enhancement in the achieved capacity by our proposed system in the VHF band compared to both previous cognitive and hybrid BPLC systems. 相似文献
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农业科技服务体系建设经历了党的十八大之前和之后两个阶段。在党的十八大之前,农业科技服务体系建设呈现出发展主义逻辑,强调发展农业生产,提升农业产业效率,实现农业产业现代化,这种效率驱动农业科技服务体系建设的效能提升,忽略了人的主体性和能动性。问卷调查的研究结果表明,党的十八大之后,农业科技服务体系建设呈现出共同富裕逻辑,在乡村振兴战略驱动下,通过植入思政元素进行价值引导,可以有效提升政府工作人员、农业科技工作者和农业生产者的个体使命感和主体能动性,从而有效提升农业科技服务效能。 相似文献
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Ricardo Sánchez-de-Madariaga José R. Fernández-del-Castillo 《Information processing & management》2009
The Yarowsky bootstrapping algorithm resolves the homograph-level word sense disambiguation (WSD) problem, which is the sense granularity level required for real natural language processing (NLP) applications. At the same time it resolves the knowledge acquisition bottleneck problem affecting most WSD algorithms and can be easily applied to foreign language corpora. However, this paper shows that the Yarowsky algorithm is significantly less accurate when applied to domain fluctuating, real corpora. This paper also introduces a new bootstrapping methodology that performs much better when applied to these corpora. The accuracy achieved in non-domain fluctuating corpora is not reached due to inherent domain fluctuation ambiguities. 相似文献
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Novel closed-form expressions for the probability density function and the average output signal-to-noise ratio at the output of a selection combiner in Weibull fading are derived. Using these expressions, the spectral efficiency of a direct sequence code division multiple access system is analytically obtained and performance evaluation results are presented. 相似文献
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松嫩平原主要土壤光谱特征分析 总被引：4，自引：0，他引：4
为了揭示松嫩平原主要土壤反射光谱特性、探讨该区土壤参数光谱速测方法，利用地物高光谱仪室内测定松嫩平原农安县主要类型土壤的光谱反射率，运用统计分析方法分析土壤参数与土壤光谱反射率及其数学变换形式的关系，并得到土壤有机质高光谱预测模型。结果表明：⑴ 有机质是松嫩平原主要土壤反射光谱特性的主要影响因素，由于区域（母质、气候等）的差异，即使同类土壤的反射光谱特性差异也很显著；⑵ 铁对松嫩平原农安县主要土壤的反射率光谱特性的影响较小；⑶ 基于反射光谱特性的有机质含量模型可以用于该区有机质含量的速测；⑷ 松嫩平原主要土壤有机质含量与总氮含量有显著的相关性，利用有机质含量高光谱预测模型可以部分揭示土壤总氮含量状况。 相似文献
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Word sense disambiguation (WSD) is meant to assign the most appropriate sense to a polysemous word according to its context. We present a method for automatic WSD using only two resources: a raw text corpus and a machine-readable dictionary (MRD). The system learns the similarity matrix between word pairs from the unlabeled corpus, and it uses the vector representations of sense definitions from MRD, which are derived based on the similarity matrix. In order to disambiguate all occurrences of polysemous words in a sentence, the system separately constructs the acyclic weighted digraph (AWD) for every occurrence of polysemous words in a sentence. The AWD is structured based on consideration of the senses of context words which occur with a target word in a sentence. After building the AWD per each polysemous word, we can search the optimal path of the AWD using the Viterbi algorithm. We assign the most appropriate sense to the target word in sentences with the sense on the optimal path in the AWD. By experiments, our system shows 76.4% accuracy for the semantically ambiguous Korean words. 相似文献
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Word sense disambiguation (WSD) is meant to assign the most appropriate sense to a polysemous word according to its context. We present a method for automatic WSD using only two resources: a raw text corpus and a machine-readable dictionary (MRD). The system learns the similarity matrix between word pairs from the unlabeled corpus, and it uses the vector representations of sense definitions from MRD, which are derived based on the similarity matrix. In order to disambiguate all occurrences of polysemous words in a sentence, the system separately constructs the acyclic weighted digraph (AWD) for every occurrence of polysemous words in a sentence. The AWD is structured based on consideration of the senses of context words which occur with a target word in a sentence. After building the AWD per each polysemous word, we can search the optimal path of the AWD using the Viterbi algorithm. We assign the most appropriate sense to the target word in sentences with the sense on the optimal path in the AWD. By experiments, our system shows 76.4% accuracy for the semantically ambiguous Korean words. 相似文献
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以系统理论、激励理论为基础,运用静态结构化技术ISM构建了政府效能解释结构模型。该模型可让效能管理者、监督者在目标制定和效能实现的过程中,沿员工、组织两大主线,掌握效能的形成和提升机理,为效能激励路径的选择提供参考。通过模型诊断指出政府部门在基本公共服务供给中可能存在五个方面的问题,据此提出基本公共服务效能激励的三条路径。 相似文献
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农林高等院校科技资源配置效率的高低在一定程度上会影响整个农业科技资源系统的运行效率。基于1993-2009年农林高等院校的面板数据,运用Malmquist-DEA指数方法对农林高等院校的科技资源配置效率进行测度的结果表明:农林高等院校技术效率平均提高了1.1个百分点,说明科技资源配置效率呈现上升的趋势,但院校之间存在一定的差异;技术进步率的降低导致农林高等院校全要素生产率平均下降了1.4个百分点;农林高等院校的规模效率值较高,反映规模更加适度。中国农业大学和南京农业大学等拥有丰富的科技资源而且配置效率也较高。 相似文献
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This paper discusses a new algebraic model of electrical networks by which a deeper understanding is achieved of the interrelation existing between a system of independent cut sets and the corresponding system of independent “contours”, in the sense of orthogonal network theory (1).The new model allows, by a redefinition of f-cut sets, to give an interpretation in terms of linear graph theory to the inverse connection matrix A.sb, i.e. to the transformation matrix between voltages in the orthogonal and the primitive reference frames, for a general choice of independent contours.Furthermore, a directly algebraic derivation of the voltage transformation is presented, recalling the properties of dual vector spaces and without invoking the principle of invariance of the instantaneous power. 相似文献
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通过分析科技金融政策的作用机理,并借鉴不同层面的创新效率评价范式,构建针对科技型中小企业创新效率评价的投入-产出指标体系。以天津地区的科技型中小企业为研究对象,通过问卷进行数据挖掘,实现政策投入的具体量化,并利用DEA-BCC模型对企业创新效率进行评价。研究发现,科技型中小企业对创新资源的利用效率较高,但迫于规模约束,投入冗余情况较为严重,尚未实现资源优化配置,导致企业整体创新效率水平低下;随生命周期发展阶段的推进,企业创新效率总体呈现上升趋势;相比传统行业而言,处于新兴行业的企业资源利用水平更优;国有控股背景的企业在整体创新效率和资源配置方面更具优势。 相似文献
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选用DEA方法将科技企业孵化器提供的各项服务作为投入变量,将孵化、经济、社会三种效益作为产出变量构建绩效评价指标体系,并采用2014年湖北省60家科技企业孵化器的相关数据对湖北省科技企业孵化器的综合效率、纯技术效率与规模效率进行综合评价。研究发现湖北省大部分科技企业孵化器DEA无效,且通过投入与产出的调整可使孵化器达到有效状态,但不同类型的科技企业孵化器在进行改革时应根据其自身特点向不同的方向侧重。此外,针对湖北省科技企业孵化器发展中存在的整体效率较低、区域发展不平衡、孵化器结构趋同等问题,给出政策建议。 相似文献
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高校作为国家创新体系的重要组成部分,如何提升其创新效率是我国建设创新型国家过程中不可回避的问题。采用三阶段超效率EBM-Windows模型对我国2007-2018年29个省(市、自治区)高校的知识创新与知识转化效率进行实证研究,研究发现：高校的知识创新效率均值为0.675,知识转化效率均值为0.543,均未实现DEA有效；东部地区高校知识转化效率显著高于中西部及东北地区；社会经济环境、政府支持、资源禀赋与市场化水平等环境因素对东部地区高校知识创新与转化阶段投入冗余程度的影响显著高于中西部及东北地区。综合分析各地区高校知识创新与转化效率值及年均增长率,设计了四种高校创新效率提升路径。最后,提出了改善高校知识创新与转化效率的对策建议。 相似文献
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Narjes Allahrabbi Yi Shi Michelle Chia Mohammad S. M. Saifullah Kian-Meng Lim Lin Yue Lanry Yung 《Biomicrofluidics》2015,9(3)
Assessment of the microbial safety of water resources is among the most critical issues in global water safety. As the current detection methods have limitations such as high cost and long process time, new detection techniques have transpired among which microfluidics is the most attractive alternative. Here, we show a novel hybrid dielectrophoretic (DEP) system to separate and detect two common waterborne pathogens, Escherichia coli (E. coli), a bacterium, and Cryptosporidium parvum (C. parvum), a protozoan parasite, from water. The hybrid DEP system integrates a chemical surface coating with a microfluidic device containing inter-digitated microelectrodes to impart positive dielectrophoresis for enhanced trapping of the cells. Trimethoxy(3,3,3-trifluoropropyl) silane, (3-aminopropyl)triethoxysilane, and polydiallyl dimethyl ammonium chloride (p-DADMAC) were used as surface coatings. Static cell adhesion tests showed that among these coatings, the p-DADMAC-coated glass surface provided the most effective cell adhesion for both the pathogens. This was attributed to the positively charged p-DADMAC-coated surface interacting electrostatically with the negatively charged cells suspended in water leading to increased cell trapping efficiency. The trapping efficiency of E. coli and C. parvum increased from 29.0% and 61.3% in an uncoated DEP system to 51.9% and 82.2% in the hybrid DEP system, respectively. The hybrid system improved the cell trapping by encouraging the formation of cell pearl-chaining. The increment in trapping efficiency in the hybrid DEP system was achieved at an optimal frequency of 1 MHz and voltage of 2.5 Vpp for C. parvum and 2 Vpp for E. coli, the latter is lower than 2.5 Vpp and 7 Vpp, respectively, utilized for obtaining similar efficiency in an uncoated DEP system. 相似文献
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The problem of event-triggered leader-following consensus control for semi-Markov multi-agent systems is investigated in this paper. A semi-Markov process is used to describe the sudden parameter changes between every agent. An adaptive event-triggered control strategy is proposed to make a balance between reducing unnecessary communication and meeting the required performance. A control protocol which can resist actuator faults is used to ensure the reliable leader-following consensus. By employing the Lyapunov–Krasovskii functional method, some sufficient conditions are provided to guarantee that the leader-following consensus can be achieved in mean-square sense. The consensus controller and the event-triggered parameter can be co-designed. Finally, the effectiveness of the proposed method is verified by a F-404 aircraft engine system. 相似文献