Various technologies have recently been developed for high-speed railways, in order to boost commercial speeds from 300 km.h: to 400 km.h-1. Among these technologies, this paper introduces the 400 km-h-1 class curren...Various technologies have recently been developed for high-speed railways, in order to boost commercial speeds from 300 km.h: to 400 km.h-1. Among these technologies, this paper introduces the 400 km-h-1 class current collection performance evaluation methods that have been developed and demonstrated by Korea. Specifically, this paper reports details of the video-based monitoring techniques that have been adopted to inspect the stability of overhead contact line (OCL) components at 400 km.h-1 without direct contact with any components of the power supply system. Unlike conventional OCL monitoring systems, which detect contact wire positions using either laser sensors or line cameras, the developed system measures parameters in the active state by video data. According to experimental results that were obtained at a field-test site established at a commercial line, it is claimed that the proposed mea- surement system is capable of effectively measuring OCL parameters.展开更多
To protect mining areas from electrical fire, it is very important to install electrical nre momtormg system to ensure safety in development of mineral resources and for buildings. In this paper, design for electrical...To protect mining areas from electrical fire, it is very important to install electrical nre momtormg system to ensure safety in development of mineral resources and for buildings. In this paper, design for electrical fire monitoring and detection system with optional sensor modules has been proposed. In addition, necessity and suitability of electrical fire monitoring and detection system with optional sensor modules in mining areas have been reviewed. The designed electrical fire monitoring and detection system suit- able for work environment of mining industry is composed by host-computer monitoring software and slave-computer detectors. Monitoring detectors are manufactured by using embedded technology. Exter- nal shells deployed have superior enclosure performances and explosion-proof properties. It is easy to install and maintain the system. In general, the system has reached, or even exceeded standards specified in national standards for performances and appearances of such devices. Test results show application of electrical fire monitoring and detection system can effectively enhance monitoring intensity over the mining areas and provide reliable guarantee to ensure orderly development of mineral resources and to protect physical and property safety of citizens in these areas.展开更多
In order to solve the distributed detection fusion problem of underwater target detection, when the signal to noise ratio (SNR) of the acoustic channel is low, a new strategy for united detection fusion and communicat...In order to solve the distributed detection fusion problem of underwater target detection, when the signal to noise ratio (SNR) of the acoustic channel is low, a new strategy for united detection fusion and communication using multiple sensors was proposed. The performance of detection fusion was studied and compared based on the Neyman-Pearson principle when the binary phase shift keying (BPSK) and on-off keying (OOK) modes were used by the local sensors. The comparative simulation and analysis between the optimal likelihood ratio test and the proposed strategy was completed, and both the theoretical analysis and simulation indicate that using the proposed new strategy could improve the detection performance effectively. In theory, the proposed strategy of united detection fusion and communication is of great significance to the establishment of an underwater target detection system.展开更多
An optically powered sensor for measuring pressure which is linked by optical fiber is developed in new scheme. Its pulse position modulation (PPM) optical signal and optical supply power for electronics in probe are...An optically powered sensor for measuring pressure which is linked by optical fiber is developed in new scheme. Its pulse position modulation (PPM) optical signal and optical supply power for electronics in probe are transmitted via a single optical fiber. The optical power is carried by a 1 300 nm laser diode (LD) and the sensing data are carried by a 850 nm LED. The remote probe uses all CMOS chips and particular modulations (PPM and PWM). Its electrical consumption including signal manipulation and LED driven current from optically converted is less than 100 μW. The laser diode supplies 5 mW optical power into the fiber. A photodetector converts sufficiently this power into electrical power to drive the whole probe operation. The optically powered distance gets up to 500 m. The novel sensor combines optical fiber and electronics technology into a system. Because of using the principle of ratio measurement between measured and reference signals, as well as light feedback,the system is available with high reliable, outstanding accuracy and repeatability.展开更多
Collaboration in wireless sensor systems must be fault-tolerant due to the harsh environmental conditions at which such systems can be deployed. This paper focuses on finding the signal processing algorithms for colla...Collaboration in wireless sensor systems must be fault-tolerant due to the harsh environmental conditions at which such systems can be deployed. This paper focuses on finding the signal processing algorithms for collaborative target detection based on the generalized approach to signal processing (GASP) in the presence of noise. The signal processing algorithms are efficient in terms of communication cost, precision, accuracy, and number of faulty sensors tolerable in the wireless sensor systems. Two types of generalized signal processing algorithms, namely, value fusion and decision fusion constructed according to GASP in the presence of noise, are identified first. When comparing their performance and communication overhead, the decision fusion algorithm is found to become superior to the value fusion algorithm as the ratio of faulty sensors to fault free sensors increases. The use of GASP under designing the value and decision fusion algorithms in wireless sensor systems allows us to obtain the same performance, but at low values of signal energy, as well as under employment of the universally adopted signal processing algorithms widely used in practice.展开更多
A cable circuit of a substation in the United Kingdom showed high level of PD activities during a survey using hand hold PD testing equipment. The authors were invited to carry out on-site PD testing experiment to fur...A cable circuit of a substation in the United Kingdom showed high level of PD activities during a survey using hand hold PD testing equipment. The authors were invited to carry out on-site PD testing experiment to further diagnose and locate the potential problem of the cable system. This paper presents the experience of the present authors carrying out the cable test. Following a brief introduction to the experiment equipments and physical connections, the paper analyses the data collected from the testing, including PD pulse shape analysis, frequency spectrum analysis and phase resolved PD pattern analysis. Associated with PD propagation direction identification, PD source diagnosis and localisation was made. Four different types of sensors, which were adapted during the testing, are shown to have different frequency bandwidths and performed differently. Aider comparing the parameters of the sensor and the PD signals detected by individual sensor, optimal PD monitoring bandwidth for cable system is suggested.展开更多
A novel distributed optical fiber vibration sensing system based on polarization detection is proposed and demonstrated. A Faraday rotator mirror is employed at the end of the system, which eliminates the slow polariz...A novel distributed optical fiber vibration sensing system based on polarization detection is proposed and demonstrated. A Faraday rotator mirror is employed at the end of the system, which eliminates the slow polarization variation of signal light and only responses to rapid polarization change caused by external vibration interference. Based on the sensing signal characteristics, the location of polarization disturbance point can be detected accurately. Experiments on polarization controller simulation and actual vibration detection show that a higher localization accuracy better than 1% is successfully obtained in 13.8 kin, 21.2 km and 35.8 km sensing fibers systems.展开更多
Optical fiber sensors have attracted considerable attention in health monitoring of aerospace composite structures. This paper briefly reviews our recent advancement mainly in Brillouin-based distributed sensing. Dama...Optical fiber sensors have attracted considerable attention in health monitoring of aerospace composite structures. This paper briefly reviews our recent advancement mainly in Brillouin-based distributed sensing. Damage detection, life cycle monitoring and shape reconstruction systems applicable to large-scale composite structures are presented, and new technical concepts, "smart crack arrester" and "hierarchical sensing system", are described as well, highlighting the great potential of optical fiber sensors for the structural health monitoring (SHM) field.展开更多
The fiber Bragg grating (FBG) strain sensors were used for on-line monitoring of the stress variation of the lined wall in the gateway retained along the goaf of No. 3203 coal mining face in Dongtan Mine. The result...The fiber Bragg grating (FBG) strain sensors were used for on-line monitoring of the stress variation of the lined wall in the gateway retained along the goaf of No. 3203 coal mining face in Dongtan Mine. The results showed that the FBG strain sensor with the wide measuring range could measure the stress variation accurately during the support process of the gateway retained along the goaf and could provide the basis to further optimize the support structure and to determine the support plan of the gateway retained along the goaf. The FBG micro-seismic sensors were used in Xinglong Mine to detect the micro-seismic signal. The signals were well received and analyzed to determine the location and energy level of the source of the micro-seismic event warning. The FBG sensors and detecting system show a significant potential for micro-seismic detection and geological disasters detection.展开更多
Chemiluminescence detection was developed as an alternative to amperometric detection for glucose analysis in a portable, microfluidicsbased continuous glucose monitoring system. Amperometric detection allows easy det...Chemiluminescence detection was developed as an alternative to amperometric detection for glucose analysis in a portable, microfluidicsbased continuous glucose monitoring system. Amperometric detection allows easy determination of hydrogen peroxide, a product of the glucose oxidasecatalyzed reaction of glucose with oxygen, by oxidation at a microelectrode. However, (micro)electrodes in direct contact with physiological sample are subject to electrode fouling, which leads to signal drift, decreased reproducibility and shortened detector lifetimes. Moreover, there are a few species present in the body (e.g. ascorbic acid, uric acid) which can undergo oxidation at the same applied potential as hydrogen peroxide. These species can thus inter- fere with the glucose measurement, reducing detection specificity. The rationale for exploring chemiluminescence as opposed to amperometric detection is thus to attempt to improve the lifetime and reproducibility of glucose analysis for monitoring purposes, while reducing interference caused by other chemicals in the body. The study reported here represents a first step in this direction, namely the realization of a microfluidic device with integrated silicon photodiode for chemiluminescence detection of glucose. This microflow device uses a chaotic mixing approach to perform enzymatic conversion of glucose, followed by reaction of the hydrogen peroxide produced with luminol to produce light at 425 nm. The chemil reaction is catalyzed by horseradish peroxidase in the presence of iodophenol. The performance of the fabricated chip was characterized to establish optimal reaction conditions with respect to sample and reagent flow rates, pH, and concentrations. A linear calibra- tion curve was obtained for current response as a function of glucose concentration in the clinically relevant range between 2 and 10 mM, with a sensitivity of 39 pA/mM (R = 0.9963, one device, n = 3) and a limit of detection of 230 ktM (S/N - 3).展开更多
A novel, cheap, disposable and single-use nanoparticles-based nanochannel platform assembled on a flexible substrate for label-free immunosensing is pre- sented. This sensing platform is formed by the dip-coating of a...A novel, cheap, disposable and single-use nanoparticles-based nanochannel platform assembled on a flexible substrate for label-free immunosensing is pre- sented. This sensing platform is formed by the dip-coating of a homogeneous and assembled monolayer of carboxylated polystyrene nanospheres (PS, 200 and 500 nm-sized) onto the working area of flexible screen-printed indium tin oxide/polyethylene terephthalate (ITO/PET) electrodes. The spaces between the self-assembled nanospheres generate well-ordered nanochannels, with inter-PS particles distances of around 65 and 24 nm respectively. The formed nanochannels are used for the effective immobilization of antibodies and subsequent protein detection based on the monitoring of [Fe(CN)6]^4- flow through diffusion and the decrease in the differential pulse voltammetric signal upon immunocomplex formation. The obtained sensing system is nanochannel-size dependent and allows human immunoglobulin G (IgG) (chosen as a model analyte) to be detected at levels of 580 ng/mL. The system also exhibits an excellent specificity against other proteins present in real samples and shows good performance with a human urine sample. The developed device represents an integrated and simple biodetection system which overcomes many of the limitations of previously reported nanochannels-based approaches and can be extended in the future to several other immuno and DNA detection systems.展开更多
文摘Various technologies have recently been developed for high-speed railways, in order to boost commercial speeds from 300 km.h: to 400 km.h-1. Among these technologies, this paper introduces the 400 km-h-1 class current collection performance evaluation methods that have been developed and demonstrated by Korea. Specifically, this paper reports details of the video-based monitoring techniques that have been adopted to inspect the stability of overhead contact line (OCL) components at 400 km.h-1 without direct contact with any components of the power supply system. Unlike conventional OCL monitoring systems, which detect contact wire positions using either laser sensors or line cameras, the developed system measures parameters in the active state by video data. According to experimental results that were obtained at a field-test site established at a commercial line, it is claimed that the proposed mea- surement system is capable of effectively measuring OCL parameters.
基金the Science & Technology Research and Development Project of Langfang Municipal City for the Year 2013 (No.2013011048)Baoding GEEHO Electric Technology Development Co.,Ltd.for financial support and help in data acquisition and statistics during preparation of this paper
文摘To protect mining areas from electrical fire, it is very important to install electrical nre momtormg system to ensure safety in development of mineral resources and for buildings. In this paper, design for electrical fire monitoring and detection system with optional sensor modules has been proposed. In addition, necessity and suitability of electrical fire monitoring and detection system with optional sensor modules in mining areas have been reviewed. The designed electrical fire monitoring and detection system suit- able for work environment of mining industry is composed by host-computer monitoring software and slave-computer detectors. Monitoring detectors are manufactured by using embedded technology. Exter- nal shells deployed have superior enclosure performances and explosion-proof properties. It is easy to install and maintain the system. In general, the system has reached, or even exceeded standards specified in national standards for performances and appearances of such devices. Test results show application of electrical fire monitoring and detection system can effectively enhance monitoring intensity over the mining areas and provide reliable guarantee to ensure orderly development of mineral resources and to protect physical and property safety of citizens in these areas.
基金Supported by the National Natural Science Foundation of China under Grant No.60972152
文摘In order to solve the distributed detection fusion problem of underwater target detection, when the signal to noise ratio (SNR) of the acoustic channel is low, a new strategy for united detection fusion and communication using multiple sensors was proposed. The performance of detection fusion was studied and compared based on the Neyman-Pearson principle when the binary phase shift keying (BPSK) and on-off keying (OOK) modes were used by the local sensors. The comparative simulation and analysis between the optimal likelihood ratio test and the proposed strategy was completed, and both the theoretical analysis and simulation indicate that using the proposed new strategy could improve the detection performance effectively. In theory, the proposed strategy of united detection fusion and communication is of great significance to the establishment of an underwater target detection system.
文摘An optically powered sensor for measuring pressure which is linked by optical fiber is developed in new scheme. Its pulse position modulation (PPM) optical signal and optical supply power for electronics in probe are transmitted via a single optical fiber. The optical power is carried by a 1 300 nm laser diode (LD) and the sensing data are carried by a 850 nm LED. The remote probe uses all CMOS chips and particular modulations (PPM and PWM). Its electrical consumption including signal manipulation and LED driven current from optically converted is less than 100 μW. The laser diode supplies 5 mW optical power into the fiber. A photodetector converts sufficiently this power into electrical power to drive the whole probe operation. The optically powered distance gets up to 500 m. The novel sensor combines optical fiber and electronics technology into a system. Because of using the principle of ratio measurement between measured and reference signals, as well as light feedback,the system is available with high reliable, outstanding accuracy and repeatability.
文摘Collaboration in wireless sensor systems must be fault-tolerant due to the harsh environmental conditions at which such systems can be deployed. This paper focuses on finding the signal processing algorithms for collaborative target detection based on the generalized approach to signal processing (GASP) in the presence of noise. The signal processing algorithms are efficient in terms of communication cost, precision, accuracy, and number of faulty sensors tolerable in the wireless sensor systems. Two types of generalized signal processing algorithms, namely, value fusion and decision fusion constructed according to GASP in the presence of noise, are identified first. When comparing their performance and communication overhead, the decision fusion algorithm is found to become superior to the value fusion algorithm as the ratio of faulty sensors to fault free sensors increases. The use of GASP under designing the value and decision fusion algorithms in wireless sensor systems allows us to obtain the same performance, but at low values of signal energy, as well as under employment of the universally adopted signal processing algorithms widely used in practice.
文摘A cable circuit of a substation in the United Kingdom showed high level of PD activities during a survey using hand hold PD testing equipment. The authors were invited to carry out on-site PD testing experiment to further diagnose and locate the potential problem of the cable system. This paper presents the experience of the present authors carrying out the cable test. Following a brief introduction to the experiment equipments and physical connections, the paper analyses the data collected from the testing, including PD pulse shape analysis, frequency spectrum analysis and phase resolved PD pattern analysis. Associated with PD propagation direction identification, PD source diagnosis and localisation was made. Four different types of sensors, which were adapted during the testing, are shown to have different frequency bandwidths and performed differently. Aider comparing the parameters of the sensor and the PD signals detected by individual sensor, optimal PD monitoring bandwidth for cable system is suggested.
基金supported by the Natioral Natural Suience Foundation of China (No.60736035)the National Basic Research Program of China (No.2010CB327603)
文摘A novel distributed optical fiber vibration sensing system based on polarization detection is proposed and demonstrated. A Faraday rotator mirror is employed at the end of the system, which eliminates the slow polarization variation of signal light and only responses to rapid polarization change caused by external vibration interference. Based on the sensing signal characteristics, the location of polarization disturbance point can be detected accurately. Experiments on polarization controller simulation and actual vibration detection show that a higher localization accuracy better than 1% is successfully obtained in 13.8 kin, 21.2 km and 35.8 km sensing fibers systems.
文摘Optical fiber sensors have attracted considerable attention in health monitoring of aerospace composite structures. This paper briefly reviews our recent advancement mainly in Brillouin-based distributed sensing. Damage detection, life cycle monitoring and shape reconstruction systems applicable to large-scale composite structures are presented, and new technical concepts, "smart crack arrester" and "hierarchical sensing system", are described as well, highlighting the great potential of optical fiber sensors for the structural health monitoring (SHM) field.
文摘The fiber Bragg grating (FBG) strain sensors were used for on-line monitoring of the stress variation of the lined wall in the gateway retained along the goaf of No. 3203 coal mining face in Dongtan Mine. The results showed that the FBG strain sensor with the wide measuring range could measure the stress variation accurately during the support process of the gateway retained along the goaf and could provide the basis to further optimize the support structure and to determine the support plan of the gateway retained along the goaf. The FBG micro-seismic sensors were used in Xinglong Mine to detect the micro-seismic signal. The signals were well received and analyzed to determine the location and energy level of the source of the micro-seismic event warning. The FBG sensors and detecting system show a significant potential for micro-seismic detection and geological disasters detection.
文摘Chemiluminescence detection was developed as an alternative to amperometric detection for glucose analysis in a portable, microfluidicsbased continuous glucose monitoring system. Amperometric detection allows easy determination of hydrogen peroxide, a product of the glucose oxidasecatalyzed reaction of glucose with oxygen, by oxidation at a microelectrode. However, (micro)electrodes in direct contact with physiological sample are subject to electrode fouling, which leads to signal drift, decreased reproducibility and shortened detector lifetimes. Moreover, there are a few species present in the body (e.g. ascorbic acid, uric acid) which can undergo oxidation at the same applied potential as hydrogen peroxide. These species can thus inter- fere with the glucose measurement, reducing detection specificity. The rationale for exploring chemiluminescence as opposed to amperometric detection is thus to attempt to improve the lifetime and reproducibility of glucose analysis for monitoring purposes, while reducing interference caused by other chemicals in the body. The study reported here represents a first step in this direction, namely the realization of a microfluidic device with integrated silicon photodiode for chemiluminescence detection of glucose. This microflow device uses a chaotic mixing approach to perform enzymatic conversion of glucose, followed by reaction of the hydrogen peroxide produced with luminol to produce light at 425 nm. The chemil reaction is catalyzed by horseradish peroxidase in the presence of iodophenol. The performance of the fabricated chip was characterized to establish optimal reaction conditions with respect to sample and reagent flow rates, pH, and concentrations. A linear calibra- tion curve was obtained for current response as a function of glucose concentration in the clinically relevant range between 2 and 10 mM, with a sensitivity of 39 pA/mM (R = 0.9963, one device, n = 3) and a limit of detection of 230 ktM (S/N - 3).
文摘A novel, cheap, disposable and single-use nanoparticles-based nanochannel platform assembled on a flexible substrate for label-free immunosensing is pre- sented. This sensing platform is formed by the dip-coating of a homogeneous and assembled monolayer of carboxylated polystyrene nanospheres (PS, 200 and 500 nm-sized) onto the working area of flexible screen-printed indium tin oxide/polyethylene terephthalate (ITO/PET) electrodes. The spaces between the self-assembled nanospheres generate well-ordered nanochannels, with inter-PS particles distances of around 65 and 24 nm respectively. The formed nanochannels are used for the effective immobilization of antibodies and subsequent protein detection based on the monitoring of [Fe(CN)6]^4- flow through diffusion and the decrease in the differential pulse voltammetric signal upon immunocomplex formation. The obtained sensing system is nanochannel-size dependent and allows human immunoglobulin G (IgG) (chosen as a model analyte) to be detected at levels of 580 ng/mL. The system also exhibits an excellent specificity against other proteins present in real samples and shows good performance with a human urine sample. The developed device represents an integrated and simple biodetection system which overcomes many of the limitations of previously reported nanochannels-based approaches and can be extended in the future to several other immuno and DNA detection systems.