为了解决电能质量在线监测和波动数据不易被获取的问题,提出一种电能在线监测系统设计方法。提出的方法中,电能在线监测系统由HLW8012芯片、RS-485通信协议和视窗控制中心(Windows Control Center,WinCC)组态的可编程逻辑控制器(Program...为了解决电能质量在线监测和波动数据不易被获取的问题,提出一种电能在线监测系统设计方法。提出的方法中,电能在线监测系统由HLW8012芯片、RS-485通信协议和视窗控制中心(Windows Control Center,WinCC)组态的可编程逻辑控制器(Programmable Logic Controller,PLC)构成,除了可以实时获取电源的输出电压、电流、功率和波动变化数据,还可以对工作温度进行监测。在实验室中对该监测系统进行验证,分析所采集的数据,验证了该系统具有一定的稳定性,能够满足使用需求。展开更多
Spectral remote sensing technique is usually used to monitor flood and waterlogging disaster.Although spectral remote sensing data have many advantages for ground information observation,such as real time and high spa...Spectral remote sensing technique is usually used to monitor flood and waterlogging disaster.Although spectral remote sensing data have many advantages for ground information observation,such as real time and high spatial resolution,they are often interfered by clouds,haze and rain.As a result,it is very difficult to retrieve ground information from spectral remote sensing data under those conditions.Compared with spectral remote sensing tech-nique,passive microwave remote sensing technique has obvious superiority in most weather conditions.However,the main drawback of passive microwave remote sensing is the extreme low spatial resolution.Considering the wide ap-plication of the Advanced Microwave Scanning Radiometer-Earth Observing System(AMSR-E) data,an AMSR-E data unmixing method was proposed in this paper based on Bellerby's algorithm.By utilizing the surface type classifi-cation results with high spatial resolution,the proposed unmixing method can obtain the component brightness tem-perature and corresponding spatial position distribution,which effectively improve the spatial resolution of passive microwave remote sensing data.Through researching the AMSR-E unmixed data of Yongji County,Jilin Provinc,Northeast China after the worst flood and waterlogging disaster occurred on July 28,2010,the experimental results demonstrated that the AMSR-E unmixed data could effectively evaluate the flood and waterlogging disaster.展开更多
It has been demonstrated by both domestic and international theories and empirical studies that inventory fluctuations are cyclical in nature, which makes it useful in monitoring how the economy is currently operating...It has been demonstrated by both domestic and international theories and empirical studies that inventory fluctuations are cyclical in nature, which makes it useful in monitoring how the economy is currently operating. Based on a survey o foyer 5,000 enterprises conducted by the People＇s Bank of China, we have attempted to compile a finished goods inventory index of the 5,000 enterprises. Through our analysis, we are able to determine that the 5,000 enterprises inventory index displays the basic features of pro-cyclicality and fits the business cycle with a lag of one quarter. Currently, the inventory index shows signs of declining after five consecutive months of increases, indicating that the expansion of enterprises＇production is temporarily slowing down.展开更多
Measures of ionizing radiation were observed in a tower which is 20 meters above the ground relative height. They show a distinct period of 24 hours oscillation during this Februaryl 1 to April 11, 2015. It is suggest...Measures of ionizing radiation were observed in a tower which is 20 meters above the ground relative height. They show a distinct period of 24 hours oscillation during this Februaryl 1 to April 11, 2015. It is suggested that these oscillations originate from radon gas （222Rn） vented from the ground floor. One Russian specific Geiger tube with associated electronics developed at ITA was used, Monitoring of ionizing radiation from 30 keV to l0 MeV shows that the X and gamma rays up to 3.0 MeV is prevalent in the region comes from the Radon gas 222Rn that decay in 214Bi and 214pb in the energies of the gamma rays 0.269, 0.609 and 1.05 MeV respectively. Then, with this simple, portable instrument was possible to monitoring the dynamics of radon gas in the region every interval minutes.展开更多
This study investigates the relationship between trading volume and returns in SET50 index Futures market in the period from April 2006 to December 2008 using 653 observations. From previous studies, we include three ...This study investigates the relationship between trading volume and returns in SET50 index Futures market in the period from April 2006 to December 2008 using 653 observations. From previous studies, we include three methodologies namely the GARCH model, the Generalized Method of Moments （GMM） to estimate systems of equations and the Granger causality test to investigate the relationship more thoroughly. In addition, we introduce the lagged volume as a new explanatory variable in the GARCH model. Overall, the results show the significant contemporaneous and dynamic relationships between trading volume and returns volatility which support the sequential information arrival hypothesis and imply some degree of market inefficiency. The results from this study also show that past information of trading volume can be used to improve the prediction of price volatility. Therefore, regulators and traders could include past information of trading volume of SET50 index futures in tracking and monitoring the market volatility level and the investment risk in order to make a timely decision.展开更多
Research on on-line diagnosis method of crack behavior abnormality in concrete dams can provide support for timely grasping abnormality state of the crack itself and achieving real-time monitoring of the dam safety.Co...Research on on-line diagnosis method of crack behavior abnormality in concrete dams can provide support for timely grasping abnormality state of the crack itself and achieving real-time monitoring of the dam safety.Considering that samples of crack effects in concrete dams increase actually over monitoring time,a superiority criterion for the on-line diagnosis is determined so as to detect the abnormality moments timely and reliably.By integrating the safety monitoring statistical model of crack effect variable with change point theory,a fluctuation method of regression coefficients is established for the on-line diagnosis.In addition,each abnormality moment is detected by the cumulative sum of regression model residuals.Results indicate that abnormality of crack behavior in concrete dams can be characterized by structural instability of crack monitoring model.And causes of crack behavior abnormality can be analyzed by the established method,which will play an important role in dam safety monitoring.Further,taking the crack in a concrete gravity-arch dam as an example,the scientific rationality and validity of the established on-line diagnosis method are confirmed.展开更多
Structural health monitoring (SHM) is a relevant topic for civil systems and involves the monitoring, data processing and interpretation to evaluate the condition of a structure, in order to detect damage. In real str...Structural health monitoring (SHM) is a relevant topic for civil systems and involves the monitoring, data processing and interpretation to evaluate the condition of a structure, in order to detect damage. In real structures, two or more sites or types of damage can be present at the same time. It has been shown that one kind of damaged condition can interfere with the detection of another kind of damage, leading to an incorrect assessment about the structure condition. Identifying combined damage on structures still represents a challenge for condition monitoring, because the reliable identification of a combined damaged condition is a difficult task. Thus, this work presents a fusion of methodologies, where a single wavelet-packet and the empirical mode decomposition (EMD) method are combined with artificial neural networks (ANNs) for the automated and online identification-location of single or multiple-combined damage in a scaled model of a five-bay truss-type structure. Results showed that the proposed methodology is very efficient and reliable for identifying and locating the three kinds of damage, as well as their combinations. Therefore, this methodology could be applied to detection-location of damage in real truss-type structures, which would help to improve the characteristics and life span of real structures.展开更多
文摘为了解决电能质量在线监测和波动数据不易被获取的问题,提出一种电能在线监测系统设计方法。提出的方法中,电能在线监测系统由HLW8012芯片、RS-485通信协议和视窗控制中心(Windows Control Center,WinCC)组态的可编程逻辑控制器(Programmable Logic Controller,PLC)构成,除了可以实时获取电源的输出电压、电流、功率和波动变化数据,还可以对工作温度进行监测。在实验室中对该监测系统进行验证,分析所采集的数据,验证了该系统具有一定的稳定性,能够满足使用需求。
基金Under the auspices of National Natural Science Foundation of China (No. 40971189)Knowledge Innovation Programs of Chinese Academy of Sciences (No. KZCX2-YW-340)China Postdoctoral Science Foundation (No. 20100471276)
文摘Spectral remote sensing technique is usually used to monitor flood and waterlogging disaster.Although spectral remote sensing data have many advantages for ground information observation,such as real time and high spatial resolution,they are often interfered by clouds,haze and rain.As a result,it is very difficult to retrieve ground information from spectral remote sensing data under those conditions.Compared with spectral remote sensing tech-nique,passive microwave remote sensing technique has obvious superiority in most weather conditions.However,the main drawback of passive microwave remote sensing is the extreme low spatial resolution.Considering the wide ap-plication of the Advanced Microwave Scanning Radiometer-Earth Observing System(AMSR-E) data,an AMSR-E data unmixing method was proposed in this paper based on Bellerby's algorithm.By utilizing the surface type classifi-cation results with high spatial resolution,the proposed unmixing method can obtain the component brightness tem-perature and corresponding spatial position distribution,which effectively improve the spatial resolution of passive microwave remote sensing data.Through researching the AMSR-E unmixed data of Yongji County,Jilin Provinc,Northeast China after the worst flood and waterlogging disaster occurred on July 28,2010,the experimental results demonstrated that the AMSR-E unmixed data could effectively evaluate the flood and waterlogging disaster.
文摘It has been demonstrated by both domestic and international theories and empirical studies that inventory fluctuations are cyclical in nature, which makes it useful in monitoring how the economy is currently operating. Based on a survey o foyer 5,000 enterprises conducted by the People＇s Bank of China, we have attempted to compile a finished goods inventory index of the 5,000 enterprises. Through our analysis, we are able to determine that the 5,000 enterprises inventory index displays the basic features of pro-cyclicality and fits the business cycle with a lag of one quarter. Currently, the inventory index shows signs of declining after five consecutive months of increases, indicating that the expansion of enterprises＇production is temporarily slowing down.
文摘Measures of ionizing radiation were observed in a tower which is 20 meters above the ground relative height. They show a distinct period of 24 hours oscillation during this Februaryl 1 to April 11, 2015. It is suggested that these oscillations originate from radon gas （222Rn） vented from the ground floor. One Russian specific Geiger tube with associated electronics developed at ITA was used, Monitoring of ionizing radiation from 30 keV to l0 MeV shows that the X and gamma rays up to 3.0 MeV is prevalent in the region comes from the Radon gas 222Rn that decay in 214Bi and 214pb in the energies of the gamma rays 0.269, 0.609 and 1.05 MeV respectively. Then, with this simple, portable instrument was possible to monitoring the dynamics of radon gas in the region every interval minutes.
文摘This study investigates the relationship between trading volume and returns in SET50 index Futures market in the period from April 2006 to December 2008 using 653 observations. From previous studies, we include three methodologies namely the GARCH model, the Generalized Method of Moments （GMM） to estimate systems of equations and the Granger causality test to investigate the relationship more thoroughly. In addition, we introduce the lagged volume as a new explanatory variable in the GARCH model. Overall, the results show the significant contemporaneous and dynamic relationships between trading volume and returns volatility which support the sequential information arrival hypothesis and imply some degree of market inefficiency. The results from this study also show that past information of trading volume can be used to improve the prediction of price volatility. Therefore, regulators and traders could include past information of trading volume of SET50 index futures in tracking and monitoring the market volatility level and the investment risk in order to make a timely decision.
基金supported by the National Natural Science Foundation of China(Grant Nos.51309195 and 51139001)the Open Foundation of State Key Laboratory of Hydrology-Water Resources(Grant No.2012490211)+1 种基金Doctoral Scientific Research Fund of Northwest A&F University in 2012(Grant No.2012BSJJ007)the Fundamental Research Funds for the Central Universities(Grant No.QN2013046)
文摘Research on on-line diagnosis method of crack behavior abnormality in concrete dams can provide support for timely grasping abnormality state of the crack itself and achieving real-time monitoring of the dam safety.Considering that samples of crack effects in concrete dams increase actually over monitoring time,a superiority criterion for the on-line diagnosis is determined so as to detect the abnormality moments timely and reliably.By integrating the safety monitoring statistical model of crack effect variable with change point theory,a fluctuation method of regression coefficients is established for the on-line diagnosis.In addition,each abnormality moment is detected by the cumulative sum of regression model residuals.Results indicate that abnormality of crack behavior in concrete dams can be characterized by structural instability of crack monitoring model.And causes of crack behavior abnormality can be analyzed by the established method,which will play an important role in dam safety monitoring.Further,taking the crack in a concrete gravity-arch dam as an example,the scientific rationality and validity of the established on-line diagnosis method are confirmed.
基金Project (No. PIFI-2012 U. de Gto.) supported by the Secretariat of Public Education (SEP), Mexico
文摘Structural health monitoring (SHM) is a relevant topic for civil systems and involves the monitoring, data processing and interpretation to evaluate the condition of a structure, in order to detect damage. In real structures, two or more sites or types of damage can be present at the same time. It has been shown that one kind of damaged condition can interfere with the detection of another kind of damage, leading to an incorrect assessment about the structure condition. Identifying combined damage on structures still represents a challenge for condition monitoring, because the reliable identification of a combined damaged condition is a difficult task. Thus, this work presents a fusion of methodologies, where a single wavelet-packet and the empirical mode decomposition (EMD) method are combined with artificial neural networks (ANNs) for the automated and online identification-location of single or multiple-combined damage in a scaled model of a five-bay truss-type structure. Results showed that the proposed methodology is very efficient and reliable for identifying and locating the three kinds of damage, as well as their combinations. Therefore, this methodology could be applied to detection-location of damage in real truss-type structures, which would help to improve the characteristics and life span of real structures.
