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EPQ信度概化的跨文化比较及其启示 被引量:7
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作者 焦璨 张敏强 +2 位作者 张洁婷 吴利 张文怡 《心理科学》 CSSCI CSCD 北大核心 2011年第6期1488-1495,共8页
对中国7种主要的心理学杂志,于1998-2008年间发表的与EPQ有关的研究报告或论文做信度概化分析,并与Caruso等人对其他国家的EPQ信度概化分析结果作比较。分析结果表明:中外心理量表使用者都存在严重的"信度引入"的状况;分量表... 对中国7种主要的心理学杂志,于1998-2008年间发表的与EPQ有关的研究报告或论文做信度概化分析,并与Caruso等人对其他国家的EPQ信度概化分析结果作比较。分析结果表明:中外心理量表使用者都存在严重的"信度引入"的状况;分量表的分数的标准差是信度系数最重要的预测变量;但其他预测变量有所不同。提供的启示是:使用心理量表时一定要报告当前样本的信度系数;不符合心理量表特性要求而增加项目,不一定能提高测验结果的信度。 展开更多
关键词 EPQ 信度 层次多元回归分析
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信度概化研究的新进展评析 被引量:6
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作者 焦璨 吴利 +1 位作者 张敏强 张文怡 《学术研究》 CSSCI 北大核心 2009年第2期54-59,共6页
信度是测验编制中不可缺的重要指标。使用已有测验开展心理问题研究或临床应用是心理研究中常用的方法和手段。测验手册的信度系数能否引入当前的研究?显然是一个有意义的问题。信度概化是以概化理论的思想及方法指导信度研究的元分析技... 信度是测验编制中不可缺的重要指标。使用已有测验开展心理问题研究或临床应用是心理研究中常用的方法和手段。测验手册的信度系数能否引入当前的研究?显然是一个有意义的问题。信度概化是以概化理论的思想及方法指导信度研究的元分析技术,这种分析技术的基本思想是:在承认测验手册信度系数基础上,重点分析测验使用时的信度系数及其变异性,以统计分析方法找出变异性产生的预测源,进而说明测验更适合的样本群体的属性和特征。它有助于研究者更为准确、有效地使用测验,以获得可靠、有效的测验分数,提升测验使用的科学性,避免"信度引入"的错误。 展开更多
关键词 信度 信度 样本属性
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大五人格测验在中国应用的信度概化分析 被引量:5
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作者 罗杰 周瑗 +2 位作者 陈维 潘运 赵守盈 《心理发展与教育》 CSSCI 北大核心 2016年第1期121-128,共8页
对过去20年(1994~2013年)间国内有关大五人格测验的研究文献进行信度概化分析。结果表明:(1)检索到的文献中约68.15%存在"信度引入"现象;(2)未加权估计中,A和O的均值最低,N和C的均值最高,国内所得结果均略低于国外(O除外),... 对过去20年(1994~2013年)间国内有关大五人格测验的研究文献进行信度概化分析。结果表明:(1)检索到的文献中约68.15%存在"信度引入"现象;(2)未加权估计中,A和O的均值最低,N和C的均值最高,国内所得结果均略低于国外(O除外),而后者的变异性略大(E除外);采用α系数效果量方法,在随机效应模型中,N的估计值最高,O和A的估计值最低;(3)回归分析显示,分数均值、量表来源和南北地域差异是N维度信度的预测变量;量表来源、文章专业类型、测验版本和测验记分对E维度信度具有预测作用;样本量、文章专业类型和量表来源是O维度信度的预测变量;量表来源、文章专业类型、项目数和样本类型对A维度信度具有预测作用;量表来源、项目数、文章专业类型和测验记分是C维度信度的预测变量。 展开更多
关键词 大五人格测验 信度 α系数 元分析
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大五人格问卷(BFI-44)信度元分析--基于信度概化方法 被引量:15
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作者 黎红艳 徐建平 +1 位作者 陈基越 范业鑫 《心理科学进展》 CSSCI CSCD 北大核心 2015年第5期755-765,共11页
查询了1991-2014近24年发表的782篇BFI-44中、英文文献,最终筛选出85篇英文文献,采用信度概化方法对其进行了元分析。分析考察了BFI-44各维度的α系数值的分布与变化范围,并以样本量、国籍、测验语言版本、平均年龄、男女比例作为预测变... 查询了1991-2014近24年发表的782篇BFI-44中、英文文献,最终筛选出85篇英文文献,采用信度概化方法对其进行了元分析。分析考察了BFI-44各维度的α系数值的分布与变化范围,并以样本量、国籍、测验语言版本、平均年龄、男女比例作为预测变量,通过回归分析探究了影响BFI-44信度水平的因素。结果显示BFI-44各维度α系数均接近0.8;样本量、国籍、男女比例对各维度的信度水平有不同程度的影响。建议在应用BFI-44测验时,要报告BFI-44当前测试样本的α系数,忌犯“信度引入”错误,同时应注意样本量、文化差异、被试比例对α系数的影响。 展开更多
关键词 大五人格问卷(BFI-44) 人格测验 信度 元分析
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信度的再认识与信度概括化研究 被引量:17
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作者 关丹丹 张厚粲 《心理科学》 CSSCI CSCD 北大核心 2004年第2期445-448,共4页
本文首先对信度概念进行了明确,指出信度是评价测验结果可靠与否的一个指标,而不是测验工具的不变属性。针对测验结果的信度估计的可变性,介绍了上世纪末Vacha-Haase提出的信度概括化研究方法,即一种用来探索得分信度估计的可变性、并... 本文首先对信度概念进行了明确,指出信度是评价测验结果可靠与否的一个指标,而不是测验工具的不变属性。针对测验结果的信度估计的可变性,介绍了上世纪末Vacha-Haase提出的信度概括化研究方法,即一种用来探索得分信度估计的可变性、并对引起变异的预测源进行探讨的一种元分析方法。最后通过对信度概括化研究手段的分析,指出信度概念的再认识与信度概括化研究将会给心理测验工作者带来新的启示。 展开更多
关键词 心理测验 再认识 信度概括 信度系数
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MMPI在中国应用的信度概化研究 被引量:7
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作者 焦璨 张洁婷 +1 位作者 吴利 张敏强 《华南师范大学学报(社会科学版)》 CSSCI 北大核心 2010年第4期48-52,共5页
对1989-2008年国内发表的有关明尼苏达多相人格测验(MMPI)的文章进行信度概化研究。对MMPI的10个临床量表和3个效度量表信度系数的报告情况、信度水平和变异性进行描述性分析;以样本类型、样本量等作为预测变量,探讨影响MMPI量表信度水... 对1989-2008年国内发表的有关明尼苏达多相人格测验(MMPI)的文章进行信度概化研究。对MMPI的10个临床量表和3个效度量表信度系数的报告情况、信度水平和变异性进行描述性分析;以样本类型、样本量等作为预测变量,探讨影响MMPI量表信度水平的因素。在此基础上,与国外关于MMPI的信度概化研究结果进行比较,结果表明二者在信度水平、信度系数的变异性及其预测源方面都存在异同。 展开更多
关键词 信度 明尼苏达多相人格测验(MMPI) 信度
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青少年时间管理倾向量表的信度概化分析 被引量:9
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作者 罗杰 赵守盈 +1 位作者 潘运 戴晓阳 《中国心理卫生杂志》 CSSCI CSCD 北大核心 2013年第4期305-309,共5页
目的:对2001~2012年国内发表的有关青少年时间管理倾向量表(ATMD)的研究文献进行信度概化分析,为ATMD使用者提供代表性的信度水平及变异性方面的参考。方法:在《中国期刊网》检索到以ATMD为测量工具公开发表的文献208篇,对最终符合筛... 目的:对2001~2012年国内发表的有关青少年时间管理倾向量表(ATMD)的研究文献进行信度概化分析,为ATMD使用者提供代表性的信度水平及变异性方面的参考。方法:在《中国期刊网》检索到以ATMD为测量工具公开发表的文献208篇,对最终符合筛选标准的18篇文献进行信度概化分析,对ATMD的3个分量表(时间价值感、时间监控观、时间效能感)信度系数的报告情况、信度水平及其变异性进行描述性分析;以样本量、量表分数均值作为预测变量建立回归方程,探讨ATMD信度系数的相关因素。结果:91.4%的文献在使用ATMD时忽视或不报告当前研究中信度系数,仅8.6%的文献报告了当前研究中的信度系数或范围;时间价值感分量表信度系数的均值最低(=0.73),时间监控观分量表信度系数的均值最高(=0.83),时间效能感分量表信度系数的变异程度(s=0.07)较前两者略大。多元逐步回归分析表明,样本量与ATMD各分量表的信度系数均相关(β=0.60,0.59,0.68,P<0.01);年龄标准差与时间监控观分量表的信度系数相关(β=-0.45,P<0.01)。结论:国内研究者使用ATMD时存在比较严重的"信度引入"现象。信度系数是测验结果的属性,其大小受到样本量等被试特征的影响。提示,研究者们在使用心理测验时,应当报告其当前研究中的信度结果。 展开更多
关键词 时间管理倾向 青少年时间管理倾向量表 信度 信度 多元回归分析 元分析
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制造业与现代化
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作者 曹来发 殷瑞芝 《科技情报开发与经济》 2003年第6期192-193,共2页
简述了世界制造业的历史及我国的现状,在肯定我国制造业取得一定成绩的基础上,分析了我国与世界发达国际制造业存在的差距与原因,最后论述了制造业与现代化的辨证关系,指出要摆脱落后挨打的局面,就要建立强大的现代化的制造业。
关键词 制造业 现代 信度化 工业 高科技
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自杀预防研究中人际需求问卷的信度概化分析 被引量:1
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作者 李诚 董燕 +2 位作者 汪萌 王进 郭久亮 《实用预防医学》 CAS 2017年第9期1044-1047,共4页
目的对2005年至今发表的有关人际需求问卷(INQ)的文献进行信度概化分析,为INQ在自杀预防研究中的应用提供描述性信度水平及影响因素的参考。方法在Embase等数据库检索到以INQ为测量工具发表的文献173篇,对最终符合筛选标准的137篇文献... 目的对2005年至今发表的有关人际需求问卷(INQ)的文献进行信度概化分析,为INQ在自杀预防研究中的应用提供描述性信度水平及影响因素的参考。方法在Embase等数据库检索到以INQ为测量工具发表的文献173篇,对最终符合筛选标准的137篇文献进行分析。采用α系数效果量法检测INQ两个维度的信度水平,并以被试数量等8个因素作为预测变量,通过加权回归分析探究影响因素。结果 INQ两个维度的描述性信度水平均在0.86以上;题目数量、被试国籍、被试数量和性别比例能显著预测TB维度的α系数(β=-0.301、0.524、-0.426,P<0.01;β=-0.151,P<0.05),被试数量能显著预测PB维度的α系数(β=-0.310,P<0.01)。结论 INQ能满足自杀预防研究对测量稳定性的要求;建议在使用时具体报告两个维度的α系数,慎选题目过少的简化版本,选取足量被试(女性比例不能过低),同时考虑不同国籍对信度的影响。 展开更多
关键词 自杀预防 人际需求问卷 加权回归分析 信度
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IMPROVED ACO SCHEDULING ALGORITHM BASED ON FLEXIBLE PROCESS 被引量:3
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作者 冷晟 魏孝斌 张文艺 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2006年第2期154-160,共7页
An improved ant colony optimization (ACO) algorithm is utilized in cell scheduling of the flexible manufaturing process for considering the instrument constraint, manufacturing cost and time. Firstly, the initial we... An improved ant colony optimization (ACO) algorithm is utilized in cell scheduling of the flexible manufaturing process for considering the instrument constraint, manufacturing cost and time. Firstly, the initial weighted directional diagram is set up. Secondly, the algorithm based on the dynamic pheromone updating ensures the quick convergence and the optimal solution, thus improving the feasibility and the stability of the schedule system. Aiming at reducing collaboration with external partners, decreasing the total cost and balancing the production process, the algorithm is efficient in supporting the management process of the manufacturing cell and in strengthening the information arrangement capabitity of the scheduling system. Finally, experimental results of the improved algorithm are compared with those of other algorithms. 展开更多
关键词 manufacturing cell cell scheduling ACO PHEROMONE
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Signal-purity-spectrum-based colored deconvolution 被引量:3
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作者 李国发 彭更新 +2 位作者 岳英 王万里 崔永福 《Applied Geophysics》 SCIE CSCD 2012年第3期333-340,362,共9页
Signal to noise ratio (SNR) and resolution are two important but contradictory characteristics used to evaluate the quality of seismic data. For relatively preserving SNR while enhancing resolution, the signal purit... Signal to noise ratio (SNR) and resolution are two important but contradictory characteristics used to evaluate the quality of seismic data. For relatively preserving SNR while enhancing resolution, the signal purity spectrum is introduced, estimated, and used to define the desired output amplitude spectrum after deconvolution. Since a real reflectivity series is blue rather than white, the effects of white reflectivity hypothesis on wavelets are experimentally analyzed and color compensation is applied after spectrum whitening. Experiments on real seismic data indicate that the cascade of the two processing stages can improve the ability of seismic data to delineate the geological details. 展开更多
关键词 signal purity spectrum SNR spectrum resolution spectrum whitening colorcompensation
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长处和困难问卷中文版的信度概化分析 被引量:24
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作者 许文兵 王孟成 +3 位作者 邓嘉欣 刘惠华 曾红 杨文登 《中国临床心理学杂志》 CSSCI CSCD 北大核心 2019年第1期67-72,共6页
目的:检验中文版长处与困难问卷信度系数(α系数、重测信度系数和分半信度)的稳定性,以及探讨α系数的影响因素。方法:根据预先设定的文献纳入标准,本研究共纳入46篇论文的60个样本(N=114576),采用信度概化元分析技术对中文版长处与困... 目的:检验中文版长处与困难问卷信度系数(α系数、重测信度系数和分半信度)的稳定性,以及探讨α系数的影响因素。方法:根据预先设定的文献纳入标准,本研究共纳入46篇论文的60个样本(N=114576),采用信度概化元分析技术对中文版长处与困难问卷的信度系数进行分析。结果:(1)三种信度的异质性显著,随机效应模型估计的α均值分别为:困难分量表0.749、情绪症状分量表0.686、品行问题分量表0.593、多动与注意不能分量表0.741、同伴关系分量表0.397和亲社会行为分量表0.743。(2)通过混合效应模型的调节分析发现:出版年份、使用版本、文献来源、出版物类型这4类研究特征对各分量表分数的α系数有不同程度的调节作用。在样本特征方面,东部沿海地区和儿童群体α系数都较低。结论:品行问题和同伴关系分量表可靠性低,题项异质程度大,建议修订题项。同时应注意样本特征和研究特征对α系数的影响,特别是用于东部沿海地区及儿童样本时需要谨慎。 展开更多
关键词 长处和困难问卷 信度 信度 元分析
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Multiple vehicle routing problem integrated reverse logistics with fuzzy reverse demands
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作者 李建 达庆利 《Journal of Southeast University(English Edition)》 EI CAS 2008年第2期222-227,共6页
A new type of vehicle routing problem (VRP), multiple vehicle routing problem integrated reverse logistics (MVRPRL), is studied. In this problem, there is delivery or pickup (or both) and uncertain features in t... A new type of vehicle routing problem (VRP), multiple vehicle routing problem integrated reverse logistics (MVRPRL), is studied. In this problem, there is delivery or pickup (or both) and uncertain features in the demands of the clients. The deliveries of every client as uncertain parameters are expressed as triangular fuzzy numbers. In order to describe MVRPRL, a multi-objective fuzzy programming model with credibility measure theory is constructed. Then the simulationbased tabu search algorithm combining inter-route and intra-route neighborhoods and embedded restarts are designed to solve it. Computational results show that the tabu search algorithm developed is superior to sweep algorithms and that compared with handling each on separate routes, the transportation costs can be reduced by 43% through combining pickups with deliveries. 展开更多
关键词 reverse logistics pickup and delivery credibility measure theory tabu search algorithm fuzzy simulation
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Feasibility investigation on deep ocean compact autonomous Raman spectrometer developed for in-situ detection of acid radical ions 被引量:10
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作者 杜增丰 李颖 +2 位作者 陈靓 郭金家 郑荣儿 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第2期545-550,共6页
A newly developed Deep Ocean Compact Autonomous Raman Spectrometer (DOCARS) system is introduced and used for in-situ detection of acid radical ions in this paper. To evaluate the feasibility and capability of DOCAR... A newly developed Deep Ocean Compact Autonomous Raman Spectrometer (DOCARS) system is introduced and used for in-situ detection of acid radical ions in this paper. To evaluate the feasibility and capability of DOCARS for quantitative analysis of the acid radical ions in the deep ocean, extensive investigations have been carried out both in laboratory and sea trials during the development phase. In the laboratory investigations, Raman spectra of the prepared samples (acid radical ions solutions) were obtained, and analyzed using the method of internal standard normalization in data processing. The Raman signal of acid radical ions was normalized by that of water molecules. The calibration curve showed that the normalized Raman signal intensity of SO4^2-, NO3^-, and HCO^-3 increases linearly as the concentration rises with correlation coefficient R^2 of 0.99, 0.99, and 0.98 respectively. The linear function obtained from the calibration curve was then used for the analysis of the spectra ,data acquired in the sea trial under a simulating chemical field in the deep-sea environment. It was found that the detected concentration of NO3 according to the linear function can reflect the concentration changes of NO~ after the sample was released, and the detection accuracy of the DOCARS system for SO^2-_4 is 8%. All the results showed that the DOCARS system has great potential in quantitative detection of acid radical ions under the deep-sea environment, while the sensitivity of the DOCARS system is expected to be improved. 展开更多
关键词 laser Raman spectroscopy Deep Ocean Compact Autonomous Raman Spectrometer (DOCARS) acid radical ions
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A Heterogeneous Information Fusion Deep Reinforcement Learning for Intelligent Frequency Selection of HF Communication 被引量:6
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作者 Xin Liu Yuhua Xu +3 位作者 Yunpeng Cheng Yangyang Li Lei Zhao Xiaobo Zhang 《China Communications》 SCIE CSCD 2018年第9期73-84,共12页
The high-frequency(HF) communication is one of essential communication methods for military and emergency application. However, the selection of communication frequency channel is always a difficult problem as the cro... The high-frequency(HF) communication is one of essential communication methods for military and emergency application. However, the selection of communication frequency channel is always a difficult problem as the crowded spectrum, the time-varying channels, and the malicious intelligent jamming. The existing frequency hopping, automatic link establishment and some new anti-jamming technologies can not completely solve the above problems. In this article, we adopt deep reinforcement learning to solve this intractable challenge. First, the combination of the spectrum state and the channel gain state is defined as the complex environmental state, and the Markov characteristic of defined state is analyzed and proved. Then, considering that the spectrum state and channel gain state are heterogeneous information, a new deep Q network(DQN) framework is designed, which contains multiple sub-networks to process different kinds of information. Finally, aiming to improve the learning speed and efficiency, the optimization targets of corresponding sub-networks are reasonably designed, and a heterogeneous information fusion deep reinforcement learning(HIF-DRL) algorithm is designed for the specific frequency selection. Simulation results show that the proposed algorithm performs well in channel prediction, jamming avoidance and frequency channel selection. 展开更多
关键词 HF communication ANTI-JAMMING intelligent frequency selection markov decision process deep reinforcement learning
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Analysis of the Effect and Solution of Geomagnetic Room Humidity on Geomagnetic Observation 被引量:1
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作者 Zhi Hongkui Cheng Nan +4 位作者 Geng Shufen Guo Hui Ma Zhiyong Chi Yuan Song Jianshuo 《Earthquake Research in China》 CSCD 2016年第2期264-270,共7页
It is not easy to control humidity in a geomagnetic room. If humidity is too high or the change is too fast it will lead to an abnormal change on data. The intelligent real-time humidity analysis and monitoring system... It is not easy to control humidity in a geomagnetic room. If humidity is too high or the change is too fast it will lead to an abnormal change on data. The intelligent real-time humidity analysis and monitoring system of a geomagnetic room and probe can not only monitor and display the change of humidity in the geomagnetic room and send an alarm signal when it exceeds the pre-set range, but also dehumidify intelligently. One can arbitrarily control the sensor to monitor the ambient humidity of the probe in order to ensure that the data is stable and true. The design idea and main functions of the system are introduced in the paper. 展开更多
关键词 Geomagnetic room humidity Fluxgate magnetometer Humidity sensorExact humidity control Intelligent real-time monitoring
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E-Government in Social and Economic Development: The Asymmetric Roles of Information, Institutionalization and Diffusion
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作者 Bongani Ngwenya 《Computer Technology and Application》 2012年第10期657-667,共11页
There are documented differences between the success and failure factors in the developed and developing countries with regard to the adoption and embracement of Openness in e-Government practice models. This paper po... There are documented differences between the success and failure factors in the developed and developing countries with regard to the adoption and embracement of Openness in e-Government practice models. This paper posits that e-Government constitutes a critical context for social and economic development in both developed and developing countries. The paper also suggests that e-Government encompasses more than just technology, that is, attempts to highlight the social and economic implications of changes that have occurred in recent years as a result of the transparency and accountability of government and how software usage can influence digital inclusion, trust and privacy and possible strategies to eliminate the digital divide by encouraging greater public and commercial use and re-use of government information through putting govermnent data on the Web. In addition to leveraging economic development, e-Government also helps to stream line govemment services to more social based values of inclusion and citizens' participation, accessibility and power relationship ratios. Although e-Government is not a new phenomenon in most developed countries such as the US, UK, Japan, most of the European countries and some developing countries in Asia and Africa which have already announced their Open Government Initiatives and data portals it also leads to greater information asymmetry among citizens and government and also, institutionalization and diffusion asymmetry of the practice of the current Openness in e-Government models within developed and developing countries. Drawing on organizational decision-making research and following the explorative and grounded based research approach the findings of this research are that the information asymmetry between citizens and government and asymmetry in institutionalization and diffusion within developed and developing countries are widely attributed to socio-economic and political variations in developed and developing countries. Unless these differences are skill fully identified and accommodated as such into the development and use models, Openness in e-Government efforts would not help achieve the social and economic development goals by both developed and developing countries. 展开更多
关键词 E-GOVERNMENT INSTITUTIONALIZATION DIFFUSION asymmetric roles social and economic development.
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Signal timing optimization model based on dual-ring phase scheme for roundabout 被引量:4
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作者 马万经 谢涵洲 +2 位作者 白玉 赵靖 杨晓光 《Journal of Central South University》 SCIE EI CAS 2013年第2期563-571,共9页
A signal optimization model for roundabout was control concept were used to eliminate the conflict points proposed based on dual-ring scheme and two stop lines for left turns and weaving sections at a roundabout. A cy... A signal optimization model for roundabout was control concept were used to eliminate the conflict points proposed based on dual-ring scheme and two stop lines for left turns and weaving sections at a roundabout. A cycle length minimization problem was considered to generate optimal signal timings for roundabout, and a set of constraints to ensure feasibility and safety of the resulting optimal signal settings were proposed. Extensive experimental analyses in comparison with signalized intersection reveal that the proposed model is quite promising for application in design of roundabout signals, and the minimum cycle length can decrease from 186 s to 79 s while the capacity increases from 8 682 pcu/h to 9 011 pcu/h under high demand scenario. Sensitivity analysis with respect to the system performance show that the lane assignment plan, number of circulatory lanes and left turn ratio are three critical factors which have dominate impacts on performance of signalized roundabout 展开更多
关键词 signalized roundabout dual-ring phase single timing optimization left-turn movement
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Spatial Agglomeration of Exhibition Enterprises on a Regional Scale in China 被引量:1
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作者 FANG Zhongquan ZHANG Ying +1 位作者 WANG Zhangjun ZHANG Lifeng 《Chinese Geographical Science》 SCIE CSCD 2017年第3期497-506,共10页
During the past two decades, the exhibition industry in China has been developing rapidly and has become an important part of the modern service industry, particularly the agglomeration characteristics of exhibition e... During the past two decades, the exhibition industry in China has been developing rapidly and has become an important part of the modern service industry, particularly the agglomeration characteristics of exhibition enterprises highlighted on the regional scale. Although the development of theoretical research on the western exhibition industry has taken place over time, the spatial perspective has not been at the centre of attention so far. This paper aims to fill this gap and report on the agglomeration characteristics of exhibition enterprises and their influential factors. Based on data about exhibition enterprises in the Pearl River Delta(PRD) during 1991–2013, using the Ripley K function analysis and kernel density estimation, this research identifies that: 1) the exhibition enterprise on the regional scale is significantly characterized by spatial agglomeration, and the agglomeration density and scale are continuously increasing; 2) the spatial pattern of agglomeration has developed from a single-center to multi-center form. Meanwhile, this paper profiles the factors influencing the spatial agglomeration of exhibition enterprises by selecting the panel data of nine cities in the PRD in 1999, 2002, 2006 and 2013. The results show that market capacity, urban informatization level and exhibition venues significantly influence the location choice of exhibition enterprises. Among them, the market capacity is a variable that exerts a far greater impact than other factors do. 展开更多
关键词 exhibition enterprises spatial agglomeration Ripley K function analysis regional scale Pearl River Delta
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A Modified Doppler Frequency Trajectory Undergoing Varying Velocities in HSR Communications
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作者 LIU Liu TAO Cheng +1 位作者 SUN Rongchen CHEN Houjin 《China Communications》 SCIE CSCD 2016年第1期17-21,共5页
The varying trajectory of Doppler frequency under changing speed motion conditionsare investigated in Highspeed Railway(HSR) scenarios.Based on the geometrical physical parameters,instantaneous Doppler trajectories an... The varying trajectory of Doppler frequency under changing speed motion conditionsare investigated in Highspeed Railway(HSR) scenarios.Based on the geometrical physical parameters,instantaneous Doppler trajectories and expression forms of the change rate arededuced,including acceleration and deceleration cases.These modified models provide more accurate and realisticapproximations in modeling rapidly fading channels. 展开更多
关键词 Doppler shift varying veloci-ty high speed railway.
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