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101.
Javier Alcaraz Nuria RamónJosé L. Ruiz Inmaculada Sirvent 《European Journal of Operational Research》2013
The existence of alternate optima for the DEA weights may reduce the usefulness of the cross-efficiency evaluation, since the ranking provided depends on the choice of weights that the different DMUs make. In this paper, we develop a procedure to carry out the cross-efficiency evaluation without the need to make any specific choice of DEA weights. The proposed procedure takes into consideration all the possible choices of weights that all the DMUs can make, and yields for each unit a range for its possible rankings instead of a single ranking. This range is determined by the best and the worst rankings that would result in the best and the worst scenarios of each unit across all the DEA weights of all the DMUs. This approach might identify good/bad performers, as those that rank at the top/bottom irrespective of the weights that are chosen, or units that outperform others in all the scenarios. In addition, it may be used to analyze the stability of the ranking provided by the standard cross-efficiency evaluation. 相似文献
102.
103.
M. Casale P. Oliveri C. Casolino N. Sinelli P. Zunin C. Armanino M. Forina S. Lanteri 《Analytica chimica acta》2012
An authentication study of the Italian PDO (protected designation of origin) extra virgin olive oil Chianti Classico was performed; UV–visible (UV–vis), Near-Infrared (NIR) and Mid-Infrared (MIR) spectroscopies were applied to a set of samples representative of the whole Chianti Classico production area. 相似文献
104.
以2006-2012年我国所发表的关于关联数据的论文为分析数据,采用文献定量分析的方法进行统计分析,从时间分布、作者分布、期刊分布、研究资助基金分布和主题分布几个方面来分析我国关联数据研究的现状。同时,总结研究中尚存在的不足,探讨研究发展的趋势。 相似文献
105.
This paper proposes an opportunistic data aggregation algorithm to support the data collection in low-duty-cycle Wireless sensor networks (WSNs) with unreliable links. In this algorithm, each sensor selectively waits for some certain time to maximize the number of packets that it can aggregate from its downstream nodes, then transmits the aggregated result to an adaptively selected upstream node following an optimal forwarding sequence. Simulation results show that the algorithm can significantly increase the data aggregation efficiency, and reduce energy consumption and message overhead. 相似文献
106.
本文仅以DGPS所采用的RTCM SC-104数据格式为例,对它的数据格式类型、电文内容和电文解码实现进行了论述,作为读者全面了解DGNSS数据流的向导。 相似文献
107.
This study contributes to international news flow literature methodologically, by significantly expanding its scope, and theoretically, by incorporating intermedia agenda-setting theory, through which we reveal how news media in different countries influence each other in covering international news. With a big data analysis of 4,708 online news sources from 67 countries in 2015, the study shows that wealthier countries not only continue to attract most of the world news attention, they are also more likely to decide how other countries perceive the world. However, international news flow is not as hierarchical and U.S.-centric as found earlier. Online-only, emerging media in core countries are not necessarily more impactful in setting the world news agenda than those in (semi)peripheral countries. 相似文献
108.
Dongho Park Nak‐Kyoung Choi Sang‐Gu Lee Jungho Hwang 《Particle & Particle Systems Characterization》2009,26(4):179-186
For this study, a 4 stage electrical low pressure impactor was designed to measure the real‐time size distribution of diesel particulate matter (DPM). For the performance evaluation, sodium chloride (NaCl) particles and dioctyl sebacate (DOS) particles were used. After evaluating the collection efficiency of each stage of the impactor, the size distributions of test particles were estimated using electrical current data and their inversion algorithm, and this was found to agree with the results obtained by a scanning mobility particle sizer (SMPS). For measurement of DPM, a common‐rail direct injection (CRDI) diesel engine, for engine speeds of 1,200 rpm and 1,500 rpm at 2.7 kgf·m, was used. Therefore, it was found that the size distribution of the DPM could be easily obtained, with the currents measured by the impactor and the data inversion algorithm, in less than 5 seconds. Furthermore, the effective density of the DPM could be obtained using the calculated results and the SMPS data. 相似文献
109.
在基于移动sink传感器网络中,传感器节点能量受限,数据收集的能耗问题一直是研究的热点.通过建立最大化最小能耗概率模型,提出一种最大化最小能耗概率(Maximizing Minimum Probability of Energy Consumption,MMPEC)数据收集方法.MMPEC对网络中子节点与汇聚节点之间的路径长度进行分布式优化,使得整个网络的能耗达到最低的概率最大化.仿真结果表明,MMPEC在能耗方面优于同类基于移动sink的WSN分层数据收集方法. 相似文献
110.