An optimal equivalent subchannel algorithm for low voltage power line communication system

According to the low voltage power line channel features,combined with adaptive bit loading and power allocation algorithm,an optimal equivalent subchannel algorithm is proposed.Under the condition of fixed amount of transmitted bits and the minimum transmitted power model,impact of optimal equivalent subchannel on the system performance is studied.The optimization algorithm sorts subchannels with similar transmission features into groups,thus the signaling load can be reduced,and the spectrum can be better used.The simulation results show that system can get lower bit error rate(BER) by adopting optimal equivalent subchannel algorithm.     

Dynamic simulation of and experimentation with tracked vehicle hydrostatic steering characteristics of zero differential systems of a power shift steering transmission

This research investigated problems influencing tracked vehicles steering dynamic characteristics, such as rolling resistance during straight driving, steering centrifugal resistance, acceleration resistance during straight driving, scratching soil resistance of steering. Based on research about the relationship between the hydraulic steering regulation speed system and its maximum stable work pressure when vehicles have central steering on good roads (such as cement and rural roads), a zero differential hydraulic steering system of power shift steering transmission can ensure that vehicles maintain straight ahead stability through reasonably matching a steering drive system. The test indicates that vehicles have good dynamic characteristics when the work pressure accounted for 60% to 80% of the security work pressure.     

A Integrate-Reset-Controlled Single Phase Power Factor Correction with High Efficiency

A novel single phase boost type power factor correction circuit is introduced .The converter's efficiency is greatly improved by improving on the traditional boost type power factor correction circuit. Integrate Reset Control circuit is adopted to realize unity power factor. The Integrate Reset Control high efficiency single phase boost type power factor corrector has these characteristics as follows: It's constant frequency operation, which is of advantage of the design of filter. The control circuit is very simple and no need for multiplier. The result is quiet perfect, the input current follows the input voltage very well. The efficiency is very high. The result of simulation and experiment proves the correction of theory analysis.     

Application of Evolutionary Programming in Optimal Reactive Power Dispatch

This paper describes an application of evolutionary programming(EP) to reactive power optimization and voltage control of power systems.Some technical problems which conclude mutation sacle,fitness value and population size have been solved to make EP practical for solving the optimal power flow problems.The computational results with EP have been compared with those obtained from a conventional gradient based optimization method.The comparision shows that EP are better than conventional methods in dealing with the optimization of noncontinuous and nonsmooth funcnons.The EP show the ability to search for the global optimum in reactive optimization that has multiple optima.     

管道补口热收缩带粘接质量的超声检测方法

为解决管道补口热收缩带剥离强度人工抽检效率低、人为因素影响大的问题,通过超声波理论分析以及对不同粘接强度管道补口试件的试验分析,以及采用超声检测技术对管道补口热收缩带的粘接质量进行无损检测,实现剥离强度的定性及半定量评价,确定了能够明显反映管道补口热收缩带剥离强度的超声波特征参数。研究表明：超声波信号平均功率和低频能量两个参量与热收缩带剥离强度呈反比,可用于剥离强度的全面、快速检测。基于这两个参数指标,采用超声波反射法对补口样品的测试结果与补口样品手动机械拉伸测试结果一致,验证了参数选择的有效性。超声波特征参数可为建立补口热收缩带粘接质量的超声无损检测方法提供参考依据。     

履带车辆静液压双流驱动转向操纵机构的设计

依据液压双流驱动履带车辆的工作原理,设计了一套与传动变速箱匹配的、能够采用方向盘控制的操纵控制机构,然后在CATIA平台上对机构进行三维实体建模,并在三维模型上对该机构进行运动模拟仿真.运动模拟仿真结果表明,控制机构达到了设计的要求.     

电量系统的数据拟合与计量方法

在电量信息采集、传输、存储的过程中,常出现丢失数据或数据突变的情况。介绍一种离散数据曲线拟合和计量方法,鉴别数据采集过程中丢失的少量数据信息,并根据采集数据值判断、自动拟合丢失的数据,进而根据这些基本量计算电量信息。     

论公权力在环境公益诉讼中的实现

我国环境公益诉讼制度得到了较快的发展,但仍然围绕着裁判机关主导的职权主义诉讼模式,这种模式在一定程度上忽视了公权力能够推动环境公益诉讼程序发展的作用。针对这一问题,以“原告”为视角分析公权力在环境公益诉讼中实现的必要性以及可行性,提出诉讼外以及诉讼内两个方面公权力的实现路径,以期保障公权力在环境公益诉讼制度建设中的促进作用。     

农电企业配电网GIS系统空间数据库设计

农电企业配电网络数据类型复杂、数据量大,如何合理组织配电系统的数据,为配电GIS系统的高级分析功能或企业层决策提供支持,进而配电网GIS系统设计的关键问题。文章介绍了配电网GIS系统数据组织、数据采集方法及空间数据库构建方法,满足系统需求。     

排污权交易中存在的若干问题

归纳总结了排污权交易理论中存在的问题,对解决这些问题的理论进行综述,以期为政府制定决策提供有价值的依据。