In this paper,an efficient unequal error protection(UEP)scheme for online fountain codes is proposed.In the buildup phase,the traversing-selection strategy is proposed to select the most important symbols(MIS).Then,in...In this paper,an efficient unequal error protection(UEP)scheme for online fountain codes is proposed.In the buildup phase,the traversing-selection strategy is proposed to select the most important symbols(MIS).Then,in the completion phase,the weighted-selection strategy is applied to provide low overhead.The performance of the proposed scheme is analyzed and compared with the existing UEP online fountain scheme.Simulation results show that in terms of MIS and the least important symbols(LIS),when the bit error ratio is 10-4,the proposed scheme can achieve 85%and 31.58%overhead reduction,respectively.展开更多
With the development of wireless sensor network(WSN)applications in intelligent monitoring,additional support for the low power consumption wireless nodes can be provided by piezoceramics that harvest vibrational ener...With the development of wireless sensor network(WSN)applications in intelligent monitoring,additional support for the low power consumption wireless nodes can be provided by piezoceramics that harvest vibrational energy.First,we describe the effects of stimulation variations on piezoceramics and the energy harvesting circuit set-up.Two types of piezoceramics were stimulated at different frequencies and amplitudes to obtain the power output characteristics.Then,the energy harvesting circuit was studied and coupled with the piezoceramics.A double peak phenomenon was found in energy harvesting using a hard piezoceramic which gave a direct proof that the nonlinearity of the piezo constant should be considered in application.Finally,energy storage and output were studied and analyzed.Electronic components for the WSN were recommended according to the output power and the application.The results will give an instruction for piezoceramic energy harvesting under various stress amplitudes on its implementation.展开更多
电能替代潜力的有效分析对于制定电能替代发展策略和促进地方节能减排具有重要意义,分析不同情景下的电能替代发展趋势,可为地区电能替代发展规划提供科学依据。提出一种多情景下基于改进粒子群-支持向量机的电能替代潜力预测模型。分...电能替代潜力的有效分析对于制定电能替代发展策略和促进地方节能减排具有重要意义,分析不同情景下的电能替代发展趋势,可为地区电能替代发展规划提供科学依据。提出一种多情景下基于改进粒子群-支持向量机的电能替代潜力预测模型。分析了电力消费占比、单位GDP能耗、城市居民可支配收入和单位GDPCO_(2)排放量等电能替代潜力影响因素指标,并进行量化处理,采用皮尔逊相关系数法筛选关键指标并引入预测模型。考虑基准发展、技术进步、经济发展和低碳环保4种发展情景,预测多情景下的电能替代潜力。对我国南方某省实际数据进行分析,将灰狼优化算法支持向量机(grey wolf optimizer-support vectormachine,GWO-SVM)和SVM模型作为对比模型,验证了所提方法具有较好的预测效果,并着重分析了2030年、2035年不同情景下的电能替代潜力,为地区未来的电能替代规划提供理论依据。展开更多
智能电网环境下,可控负荷参与低频减载（under frequency load shedding,UFLS）协助电力系统辅助调频,成为了新型低频减载研究的重点。新型低频减载策略对于负荷调节的时效性以及准确性要求较高,但负荷的通信状态和用户被控意愿等问题...智能电网环境下,可控负荷参与低频减载（under frequency load shedding,UFLS）协助电力系统辅助调频,成为了新型低频减载研究的重点。新型低频减载策略对于负荷调节的时效性以及准确性要求较高,但负荷的通信状态和用户被控意愿等问题会对调频减载结果造成影响。该文综合考虑上述问题,对负荷通信延迟、丢包进行建模,同时考虑用户被控次数,提出了一种新型集群控制策略。该文首先分析了简化的发电机–负荷模型下的通信状态对调频减载结果的影响,而后基于此提出了考虑通信状态与控制均衡的负荷群参与低频减载的优化控制方案。最后以IEEE3机9节点系统模型为例,对优化控制策略的效果进行验证。仿真结果说明了控制策略对负荷群的控制具有低延时、高准确性的特点,能够保证控制动作的及时性,从而抑制系统频率下降深度,减少频率调节误差,大大降低了系统失稳的风险。展开更多
为降低电力通信网多优先级业务传输的失效概率,提高系统可靠性,提出一种基于业务优先级和共享风险链路组(shared risk link groups,SRLG)的电力需求响应调度优化算法。根据电力通信网业务的分类,将需求响应业务进行业务优先级的分区定位...为降低电力通信网多优先级业务传输的失效概率,提高系统可靠性,提出一种基于业务优先级和共享风险链路组(shared risk link groups,SRLG)的电力需求响应调度优化算法。根据电力通信网业务的分类,将需求响应业务进行业务优先级的分区定位,提出电力需求响应业务传输的信用值整形机制(credit-basedshaper,CBS),对不同优先级业务的传输调度机制进行描述。考虑电力通信网的共享风险链路组,对不同优先级业务调度路径的选择进行优化,实现所选路径的高可靠性。仿真结果表明,所提算法可以有效降低需求响应业务调度路径的SRLG综合失效概率和风险,平均节点处理时延较小,很好地保证了需求响应业务传输的可靠性和安全性。展开更多
基金supported by the National Natural Science Foundation of China(61601147)the Beijing Natural Science Foundation(L182032)。
文摘In this paper,an efficient unequal error protection(UEP)scheme for online fountain codes is proposed.In the buildup phase,the traversing-selection strategy is proposed to select the most important symbols(MIS).Then,in the completion phase,the weighted-selection strategy is applied to provide low overhead.The performance of the proposed scheme is analyzed and compared with the existing UEP online fountain scheme.Simulation results show that in terms of MIS and the least important symbols(LIS),when the bit error ratio is 10-4,the proposed scheme can achieve 85%and 31.58%overhead reduction,respectively.
基金the financial support from the China Postdoctoral Science Foundation (No.2015M580587)
文摘With the development of wireless sensor network(WSN)applications in intelligent monitoring,additional support for the low power consumption wireless nodes can be provided by piezoceramics that harvest vibrational energy.First,we describe the effects of stimulation variations on piezoceramics and the energy harvesting circuit set-up.Two types of piezoceramics were stimulated at different frequencies and amplitudes to obtain the power output characteristics.Then,the energy harvesting circuit was studied and coupled with the piezoceramics.A double peak phenomenon was found in energy harvesting using a hard piezoceramic which gave a direct proof that the nonlinearity of the piezo constant should be considered in application.Finally,energy storage and output were studied and analyzed.Electronic components for the WSN were recommended according to the output power and the application.The results will give an instruction for piezoceramic energy harvesting under various stress amplitudes on its implementation.
文摘电能替代潜力的有效分析对于制定电能替代发展策略和促进地方节能减排具有重要意义,分析不同情景下的电能替代发展趋势,可为地区电能替代发展规划提供科学依据。提出一种多情景下基于改进粒子群-支持向量机的电能替代潜力预测模型。分析了电力消费占比、单位GDP能耗、城市居民可支配收入和单位GDPCO_(2)排放量等电能替代潜力影响因素指标,并进行量化处理,采用皮尔逊相关系数法筛选关键指标并引入预测模型。考虑基准发展、技术进步、经济发展和低碳环保4种发展情景,预测多情景下的电能替代潜力。对我国南方某省实际数据进行分析,将灰狼优化算法支持向量机(grey wolf optimizer-support vectormachine,GWO-SVM)和SVM模型作为对比模型,验证了所提方法具有较好的预测效果,并着重分析了2030年、2035年不同情景下的电能替代潜力,为地区未来的电能替代规划提供理论依据。
文摘智能电网环境下,可控负荷参与低频减载（under frequency load shedding,UFLS）协助电力系统辅助调频,成为了新型低频减载研究的重点。新型低频减载策略对于负荷调节的时效性以及准确性要求较高,但负荷的通信状态和用户被控意愿等问题会对调频减载结果造成影响。该文综合考虑上述问题,对负荷通信延迟、丢包进行建模,同时考虑用户被控次数,提出了一种新型集群控制策略。该文首先分析了简化的发电机–负荷模型下的通信状态对调频减载结果的影响,而后基于此提出了考虑通信状态与控制均衡的负荷群参与低频减载的优化控制方案。最后以IEEE3机9节点系统模型为例,对优化控制策略的效果进行验证。仿真结果说明了控制策略对负荷群的控制具有低延时、高准确性的特点,能够保证控制动作的及时性,从而抑制系统频率下降深度,减少频率调节误差,大大降低了系统失稳的风险。
文摘为降低电力通信网多优先级业务传输的失效概率,提高系统可靠性,提出一种基于业务优先级和共享风险链路组(shared risk link groups,SRLG)的电力需求响应调度优化算法。根据电力通信网业务的分类,将需求响应业务进行业务优先级的分区定位,提出电力需求响应业务传输的信用值整形机制(credit-basedshaper,CBS),对不同优先级业务的传输调度机制进行描述。考虑电力通信网的共享风险链路组,对不同优先级业务调度路径的选择进行优化,实现所选路径的高可靠性。仿真结果表明,所提算法可以有效降低需求响应业务调度路径的SRLG综合失效概率和风险,平均节点处理时延较小,很好地保证了需求响应业务传输的可靠性和安全性。
