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针对未知支持集贝叶斯匹配追踪算法中支持集搜索过于复杂的问题,提出一种改进的贝叶斯稀疏信道估计算法。该算法利用信道的稀疏特性来提高信道估计精度,通过计算信道期望来估计高维稀疏信道。为了提高支持集的搜索准确度,改进算法在支配支持集的搜索过程中引入了维特比路径译码的思想,保留所有发生概率差异低于门限的路径,并对支持集上的信道估计值进行计算,最后计算出信道期望并作为最后的信道估计值。理论分析和仿真结果都表明,改进算法在降低算法复杂度的同时还保持了较高的估计精度。

针对无线传感器网络体系在随机部署过程中出现覆盖空洞的现象,借助于概率模型提出了一种CHCAEDS（基于事件驱动策略的覆盖空洞补偿算法）。该算法首先对随机部署的特性进行验证,给出随机部署表示形式;然后利用概率相关知识对监测区域内覆盖期望和节点数量进行求解,以达到使用最少数量的节点覆盖最大的面积。仿真实验表明,与其他算法相比,CHCAEDS在网络生存周期和算法运行时间上分别提高了12.59%和10.82%。

为了更好地解决无线传感器网络在覆盖过程中出现大量冗余信息及节点能量消耗不均衡等现象,提出了一种节点能量均衡的最优覆盖算法。该算法利用监测区域内传感器节点与目标节点的从属关系建立网络模型,给出传感器节点与目标节点之间的从属关系;通过从属关系和概率理论,求解传感器节点对目标节点的覆盖期望值,然后计算出覆盖监测区域所需最少传感器节点数量。实验结果表明,该算法不仅可以使用最少传感器节点完成对监测区域的有效覆盖,而且抵制了冗余信息数据的产生,提高了网络生存周期。

对监测区域进行有效地覆盖以及最大限度延长网络生存周期是无线传感器网络研究的重点课题之一。为此,提出了一种基于节点调度策略的能量有效覆盖算法,该算法通过泊松分布模型构造节点概率密度公式,依照节点密度公式对所关注的目标进行有效覆盖;另一方面,通过节点自身状态调度机制更新以及对邻居节点进行匹配调度的动态转换,使得传感器节点剩余能量与节点消耗能量趋于平衡,从而达到延长网络生存周期。仿真实验结果表明,该算法可实现对监测区域的有效覆盖,同时优化了网络资源的配置,延长了网络生存周期。

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Gold (1001-1277) is the property of Gold Magazine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Science Technology & Engineering is the property of Chinese Society of Technology Economics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Stability of body inclination, work quality and safety can be required during agricultural machinery operation in hilly and mountainous areas. In this study, an omnidirectional leveling system was designed for the crawler work machine. A structural scheme was also proposed with an articulated omnidirectional leveling system using a “three-layer frame”. The leveling hydraulic circuit was provided for the working principle of the omnidirectional leveling system. Secondly, a sensitivity analysis was conducted on the omnidirectional leveling performance, including the key structural parameters LAE, LBC, LCD, LHO, LIJ, and LIJ. The results showed that the displacement of the lateral leveling cylinder increased with the increase of LAE and LCD, whereas, decreased with the increase of LBC. The displacement of the longitudinal leveling cylinder increased with the increase of LJK and LIJ, while decreasing with the increase of LHO. The average thrust of the lateral leveling hydraulic cylinder decreased with the increase of LAE and LCD, but the leveling time increased. By contrast, the average thrust of the longitudinal leveling hydraulic cylinder increased with the increase of LJK, but the leveling time decreased. A multi-objective genetic algorithm (GA) was designed to optimize the key structural parameters, taking the key structural parameters of the omnidirectional leveling system as the optimization variables, and the average thrust of the hydraulic cylinder and leveling time as the optimization objectives. Then, the overturning model was established for the omnidirectional leveling crawler work machine. The overturning stability of the whole machine was verified to analyze the static lateral limit overturning angle, static longitudinal limit overturning angle, and dynamic limit driving speed of the crawler work machine. The lateral and longitudinal limit overturning angles of the unleveled crawler work machine were 43.6˚, and 60.7˚, respectively, whereas, they were 46.7˚, and 68.9˚, respectively, after leveling. The lateral/longitudinal limit overturning angles after leveling increased by 7.1% and 13.5%, respectively. There was an increase in the maximum driving slope of the crawler work machine, compared with the non-leveling one. The limit driving speed of the crawler work machine to do circular motion on a flat road surface was 4.3m/s, when the radius of circular motion was 2m. Once the slope was 20˚, the dynamic limit driving speeds were 2.9 and 3m/s for the unleveled and omnidirectional leveling crawler work machine, respectively, which increased by 3.4%. Finally, an omnidirectional leveling performance test was conducted to verify the system effectiveness. The test results indicated that the lateral and longitudinal leveling times were 3.4 and 3.6s, respectively, under static testing. By contrast, the maximum body inclination angle of the omnidirectional leveling crawler work machine decreased outstandingly and then quickly leveled under dynamic testing. The body inclination angle can be maintained within ±1.5˚ on the flat road and after leveling, which fully met the performance requirements of hilly and mountainous areas. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Jiangsu University (Natural Science Edition) / Jiangsu Daxue Xuebao (Ziran Kexue Ban) is the property of Editorial Department of Journal of Jiangsu University (Natural Science Edition) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Jiangsu University (Natural Science Edition) / Jiangsu Daxue Xuebao (Ziran Kexue Ban) is the property of Editorial Department of Journal of Jiangsu University (Natural Science Edition) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Jiangsu University (Natural Science Edition) / Jiangsu Daxue Xuebao (Ziran Kexue Ban) is the property of Editorial Department of Journal of Jiangsu University (Natural Science Edition) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Modern Laboratory Medicine is the property of Journal of Modern Laboratory Medicine Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Computer Engineering & Applications is the property of Beijing Journal of Computer Engineering & Applications Journal Co Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Computer Engineering & Applications is the property of Beijing Journal of Computer Engineering & Applications Journal Co Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To coordinate the contradiction between improving the dynamic performance and reducing the energy consumption of the system, the hybrid electromagnetic active suspension (HEMAS) was used as a potential solution. Based on the improved skyhook control strategy, the general energy-saving mechanism of HEMAS was realized compared with linear electromagnetic active suspension (LEMAS). Taking the passive suspension and the LEMAS as comparison objects, a comparison bench test was carried out. The test results show that compared with passive suspension, the RMS of vehicle acceleration and suspension dynamic deflection of the HEMAS are respectively reduced by 23.35% and 14.97% with good tire grounding ability. Compared with LEMAS, the electric power consumption of the HEMAS is reduced by 70.60% for the same dynamic performance, which verifies the superiority of HEMAS with consideration of the system dynamic performance and energy consumption. [ABSTRACT FROM AUTHOR]

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Jiangsu University (Natural Science Edition) / Jiangsu Daxue Xuebao (Ziran Kexue Ban) is the property of Editorial Department of Journal of Jiangsu University (Natural Science Edition) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)