共查询到20条相似文献，搜索用时 127 毫秒
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结合定性和定量分析方法构建珠三角自主创新能力衡量指标体系,利用目前比较流行的主成分分析方法进行综合指标合成,测算珠三角九市2009—2013年的自主创新能力得分并对其进行排名。自主创新效率问题往往为众多学者和决策者忽略,强调自主创新能力不仅要有绝对指标,而且要有相对指标,也就是自主创新的效率指标,利用数据包络分析法测算珠三角九市的创新效率得分并对其进行比较。 相似文献
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辛督强 《中国科技期刊研究》2012,23(2):224-227
以2009版中国期刊引证报告（扩展版）15个计量指标数据为依托,采用主成分分析法对13种力学类中文期刊进行分析和排名,以期为力学期刊评价指标的选取和综合质量的提高提供定量参考。结果表明：主成分分析法不仅可以解决期刊综合评价中指标的相关性和权重选取问题,还可以有效消除自引过高导致的影响力评价失真问题;基于主成分分析的期刊综合排名是期刊文献质和量相统一的结果,其与绝对量指标的关联度要高于与相对量指标的关联度。 相似文献
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本文首先借助生产法构建了符合我国国情的港口生产效率评价指标体系,弥补了类似研究中的指标选择及统计、量化方法不完善。第二,建立了基于DEA港口生产效率评价模型,借助主成分分析法解决了指标过多的问题,并定量探讨了影响港口生产效率的主要因素,客观地评价港口生产效率。第三,对大连港等8个国内主要港口生产效率进行了实证研究,分析了影响港口生产效率的主要因素,并得出港口的生产效率值与相对排序。第四,本研究为我国港口生产效率的提高提出了有针对性的政策建议。 相似文献
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本文以陕西省26家上市公司为研究样本,通过主成分分析法构建了陕西上市公司的财务预警模型。首先用主成分分析法对样本公司指标进行处理,提取主成分以实现对指标的简化,最终得出陕西上市公司的财务预警指标综合评价得分。在文章的结论部分,对陕西上市公司的财务状况以及地区差异进行了综合评价分析。 相似文献
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区域科技资源的配置效率是在一定的区域内,结合科技投入和科技产出的相关数据,来反映区域科技配置水平和配置成果的一种指标。文章根据陕西省各市的科技统计数据,建立了数据分析的指标体系,并采用主成分分析的方法对其进行处理分析,对改进陕西资源配置提出了建议。 相似文献
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基本科研业务费的投入使得学院的科研经费规模提高,如何合理有效地使用科研经费,对于高校的科研发展具有重要的意义。本文从资源利用效率的角度出发,根据学科的差异性,选取某高校9个学院中的7个理工科学院为研究对象,利用主成分分析法和数据包络分析的方法建立指标体系,对已有校基金2003年-2008年的科研成果进行评价,为基本科研业务费的使用提供部分建议。 相似文献
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为了解决现有主成分法存在的无法赋权及合理筛选指标的问题,提出了基于信息敏感性的指标筛选与赋权模型。本文的主要创新与特色:一是通过主成分占原始指标集信息的比例与每个被保留的主成分对指标的偏导数乘积的和,反映该指标对原始指标集信息的影响程度。依据信息敏感性指标筛选标准确定累积信息含量,通过累积信息含量的大小遴选指标。二是通过指标的信息敏感性占全部指标信息敏感性的比例进行指标的赋权,以使指标的权重反映不同指标相对信息含量的大小。最后,通过一个实例将提出的指标筛选方法与现有主成分指标筛选方法进行了对比分析,以此说明所提出的指标筛选方法的可行性及有效性。 相似文献
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针对知识产权风险投资项目风险评估过程中的复杂模糊关系,提出一种直觉模糊多属性群决策问题求解的方法。首先,借助直觉模糊数,改进语言变量法和定量指标值转换公式,将专家关于指标的原始评价值全部标准化。而后,应用熵度量的新方法确定指标权重,并以专家对项目的了解程度衡量决策权力。进一步地,将TOPSIS引入群体评价。最后,经算例证明这种方法兼具可操作性和实用性,能得到可靠的评估结果,有利于风险投资者正确筛选项目。 相似文献
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In text categorization, it is quite often that the numbers of documents in different categories are different, i.e., the class distribution is imbalanced. We propose a unique approach to improve text categorization under class imbalance by exploiting the semantic context in text documents. Specifically, we generate new samples of rare classes (categories with relatively small amount of training data) by using global semantic information of classes represented by probabilistic topic models. In this way, the numbers of samples in different categories can become more balanced and the performance of text categorization can be improved using this transformed data set. Indeed, the proposed method is different from traditional re-sampling methods, which try to balance the number of documents in different classes by re-sampling the documents in rare classes. Such re-sampling methods can cause overfitting. Another benefit of our approach is the effective handling of noisy samples. Since all the new samples are generated by topic models, the impact of noisy samples is dramatically reduced. Finally, as demonstrated by the experimental results, the proposed methods can achieve better performance under class imbalance and is more tolerant to noisy samples. 相似文献
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针对企业是否适合采纳应用云计算的问题提出一种新的基于差值和改进TOPSIS的多属性群决策方法。首先结合成本和技术-组织-环境(TOE)框架提出企业云计算采纳应用的评价标准,然后利用平均差和标准差最大化方法确定未知属性权重向量,再利用一种改进的逼近理想解(TOPSIS)方法获取决策者之间的权重,最后利用语言加权算术平均(LWAA)算子对各决策专家给出的偏好信息集结算出综合评价值以及上限和下限值,通过比较评价值和上限、下限值决定企业是否适合采纳应用云计算技术。算例分析证明了研究提出的方法的有效性。 相似文献
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Takagi-Sugeno (T-S) fuzzy models can provide an effective representation of complex nonlinear systems with a series of linear input/output submodels in terms of fuzzy sets and fuzzy reasoning. In this paper, the T-S fuzzy model approach is extended to the stability analysis and controller design for nonlinear systems with time delays. An improved stability condition is proposed by introducing adjustable parameters into the Lyapunov-Krasovskii functional. Stabilization approach for fuzzy state feedback is also presented. Sufficient conditions for the existence of fuzzy feedback gain are derived through the numerical solution of a set of obtained linear matrix inequalities (LMIs). Compared with the existing methods in the literature, the proposed approach has less conservatism and both the sizes of delay and its derivative are involved in the criterion. The dynamical performance of the system can be adjusted by changing the adjustable parameters. Finally, two examples are given to show the effectiveness of the proposed approach. 相似文献
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[目的/意义]基于科技文献构建问题—方法矩阵,探索科技文献研究内容新颖性评估方法,辅助科技查新应用。[方法/过程]对科技文献内容进行信息抽取,提取研究问题和方法内容文本并构建问题—方法矩阵。利用LDA模型对科技文献采用的问题与方法进行分类,将科技文献在问题—方法矩阵中定位并可视化。通过设定阈值划分区域,确定待评估科技文献研究问题和方法所在区域,进行新颖性评估分析,并通过实验验证该方法的有效性。[结果/结论]提出的基于问题—方法矩阵的文献新颖性评估方法通过可视化方式不仅有利于辅助科技查新判断,还可服务于创新选题。[局限]基于科技文献的研究问题与方法信息抽取和新颖性评估计算的自动化方法有待进一步研究。 相似文献
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《Journal of The Franklin Institute》2022,359(18):11068-11088
The formation control problem with time-varying characteristics is investigated for the time-delayed nonlinear multi-agent systems against actuator attacks. A neural-network-based adaptive control method is constructed to achieve the desired control objective, which is outputs of the followers can complete the desired transformation of formation configuration. To eliminate the influence of malicious attacks on the actuators, an actuator attacks defense strategy is proposed to resist false data injection attacks occurred in the actuator. The uncertainty of the dynamics caused by nonlinear functions is resolved by the neural-network approximate method. The problem of the time delay is handled by an improved Lyapunov-Krasovskii functional approach, which can also avoid the singularity problem that may occur during the construction of the control method. Based on the Lyapunov stability theory, it is proved that all signals of closed-loop systems are semi-globally stable and the formation error can converge to a small neighborhood of the origin. Finally, the results of simulations are provided to verify the feasibility of the theoretical analysis and the effectiveness of the proposed control method. 相似文献
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《Journal of The Franklin Institute》2022,359(15):8188-8200
This work investigates the improved stability conditions for linear systems with time-varying delays via various augmented approaches. Some augmented approaches are augmented Lyapunov-Krasovskii functionals, augmented zero equalities, and the augmented zero equality approach. At first, by constructing augmented Lyapunov-Krasovskii functionals including the state vectors which were not considered in the previous works and augmented zero equalities, a stability criterion is proposed in the forms of linear matrix inequalities. Through the proposed Lyapunov-Krasovskii functionals and an additional functional derived from the integral inequality, a slightly improved result is derived. The proposed results do not consider the increase in the computational complexity to achieve a larger delay bound. So, by applying the augmented zero equality approach, which is a method of grafting the proposed augmented zero equality proposed in Finsler Lemma, to the proposed result, an enhanced stability result was derived. Also, the computational complexity is reduced by appropriately adjusting any vector of the integral inequality utilized in the proposed criteria. By applying some numerical examples to the proposed conditions, the effectiveness and superiority of the results are confirmed. 相似文献
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Hong-Guang Ma Xiao-Fei Zhu Jian-Feng Xu Ming-Shun Ai 《Journal of The Franklin Institute》2008,345(1):75-86
A new testing method for analog circuit is proposed in this paper. A low-pass Butterworth filter is taken as the typical system under test (SUT) since the analog circuits in different types of electronic systems can be regarded as the low-, band- or high-pass active (passive) filters. The chaotic signal, which is generated by an improved Chua's circuit, is employed as the excitation signal of SUT. The SUT is a “narrowband” system compared with the bandwidth of input signal, whose state is analyzed with an error-tracking approach. The experimental result depicts that this testing method can efficiently detect the change of the circuit parameter. Besides, another eight features are extracted from the output signal of SUT for analyzing the SUT states. A discussion is made for comparing the effectiveness of each feature according to the testing results. 相似文献
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基于Malmquist指数的我国电信业动态效率研究 总被引：7，自引：0，他引：7
在运用数据包络模型分析我国电信业技术效率和规模收益状况的基础上,使用衡量产业效益水平的Malmquist指数研究了我国电信业的生产率增长水平及其变迁。实证结果表明:技术效率的改善而非技术进步是我国电信业生产率增长的源泉,竞争是改进运营商技术效率、促进生产率增长的有效手段。 相似文献
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《Journal of The Franklin Institute》2022,359(16):9006-9021
This paper pays attention to the finite-time stability problem for the singular system with time delay. Some improved inequalities are presented and by employing these inequalities along with the Lyapunov-Krasovskii functional method, an improved sufficient condition which ensures that the investigated system is regular, impulse-free and finite-time stable is derived. Finally, a numerical example is provided to demonstrate the effectiveness and superiority of the proposed approach. 相似文献