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用改进的SPEA求解轨道转移的时间-能量极小化问题 被引量:3
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作者 王石 戴金海 《天文学报》 CSCD 北大核心 2003年第2期197-203,共7页
提出了改进的SPEA,这是一种多目标进化算法。适于求解大尺度空间的多目标优化的Pareto最优解。并应用于求解轨道转移的时间—能量极小化问题,计算结果表明算法的有效性。
关键词 轨道转移 时间-能量优化 火箭飞行力学 改进SPEA
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Sensing Time Optimization in Energy-Harvesting Cognitive Radio with Interference Rate Control 被引量:3
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作者 DENG Zhian LIU Xin +1 位作者 JIA Min LU Weidang 《China Communications》 SCIE CSCD 2016年第1期47-56,共10页
In this paper,an energy-harvesting cognitive radio(CR) is considered,which allows the transmitter of the secondary user(SU) to harvest the primary signal energy from the transmitter of the primary user(PU) when the pr... In this paper,an energy-harvesting cognitive radio(CR) is considered,which allows the transmitter of the secondary user(SU) to harvest the primary signal energy from the transmitter of the primary user(PU) when the presence of the PU is detected.Then the harvested energy is converted into the electrical power to supply the transmission of the SU at the detected absence of the PU.By adopting the periodic spectrum sensing,the average total transmission rate of the SU is maximized through optimizing the sensing time,subject to the constraints of the probabilities of false alarm and detection,the harvested energy and the interference rate control.The simulation results show that there deed exists an optimal sensing time that maximizes the transmission rate,and the maximum transmission rate of the energy-harvesting CR can better approach to that of the traditional CR with the increasing of the detection probability. 展开更多
关键词 cognitive radio spectrum sensing energy detection energy harvest transmission rate
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Modeling and Optimization of Relocation of Some Heavy Metals and Micro-nutrients in the Argan Trees
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作者 Faez Abdullah Esmail Mohammed Rahma Bchitou +2 位作者 Jean Michel Roger Ahmed Bouhaouss Bernard Palagos 《Journal of Chemistry and Chemical Engineering》 2011年第7期663-669,共7页
This work constitutes a contribution to the study of the physical-chemical performance of some heavy metals and micro-nutrients in the Argan trees. The samples are harvested from small Argan trees, three samples (soi... This work constitutes a contribution to the study of the physical-chemical performance of some heavy metals and micro-nutrients in the Argan trees. The samples are harvested from small Argan trees, three samples (soil, wood, leaves) per tree. The content of various heavy metals and micro-nutrient in aerial parts (leaves, wood and soil) were analyzed in the Argan tree by the method of ICP-ES. The results of analysis of data for the chemical variables were measured for several trees at different measurement times, do not affect the dispersion of the data. The use of chemometrics has allowed us to interpret the results obtained especially those related to the characterization of heavy metals and micro-nutrient after calibration by variable regression of these results in order to get an overall estimate of the optimal content, and to follow changes in the methods of treatment. The results of the characteristics of Argan trees have been treated using the statistical method of Principal Component Analysis (MFA), The MFA was used to analyze the three groups simultaneously. These groups are fairly similar. 展开更多
关键词 Heavy metals micro-nutrients argan trees principal component analysis MFA ICP-AES.
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Optimization of Bacterial Doses and Incubation Time on Bio-Ehanol Fermentation of Nipah (Nypa fruticans) for Biofuel Energy
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作者 Wiludjeng Trisasiwi Ari Asnani Retna Setyawati 《Journal of Life Sciences》 2011年第12期1022-1029,共8页
Nipah (Nypafruticans) is a species of palm trees that grows in mangroves environment near the sea shore. Nipah is potential to produce biofuel energy. The purposes of this research were 1) to determine the optimum ... Nipah (Nypafruticans) is a species of palm trees that grows in mangroves environment near the sea shore. Nipah is potential to produce biofuel energy. The purposes of this research were 1) to determine the optimum bacterial concentration for fermentation to produce high concentration of bio-ethanol, and 2) to determine the optimum incubation time for fermentation to produce high concentration of bio-ethanol. The research had been conducted from June until November 2009 using nipah sap as the substrate and Saceharomyces cerevisiae as a fermentation starter. The experimental design used was a randomized block design (RBD). Factors tested were starter concentration (5%, 7.5%, 10%) and incubation time (2, 4, 6 days). The variables observed were concentration of reducing sugar, total microorganism (CFU/mL), and bio-ethanol production. The results showed that the highest yield of bio-ethanol (8.98%) was produced with 7.5% of starter concentration and 6 days of incubation time. 展开更多
关键词 BIO-ETHANOL bacterial concentration incubation time Nypafruticans Saccharomyces cerevisiae
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