As an important parameter in the single airborne passive locating system, the rate of phase difference change contains range information of the radio emitter. Taking single carrier sine pulse signals as an example, th...As an important parameter in the single airborne passive locating system, the rate of phase difference change contains range information of the radio emitter. Taking single carrier sine pulse signals as an example, this article illustrates the principle of passive location through measurement of rates of phase difference change and analyzes the structure of measurement errors. On the basis of the Cramér-Rao lower bound (CRLB), an algorithm associated with time-chips is proposed to determine the rates of pha...展开更多
Short baseline system (SBL), which is a kind of underwater acoustic locating technology, has widely applicable value. In order to examine the capability of ship model design, the ship model experimentation should have...Short baseline system (SBL), which is a kind of underwater acoustic locating technology, has widely applicable value. In order to examine the capability of ship model design, the ship model experimentation should have high accuracy. This paper focuses on the key techniques of high accuracy locating system, including high accuracy sub-array position emendation, divisional locating, anti multi-path interference measure, etc. Experiments show that the SBL locating systems has received the satisfying effect owing to these key techniques proposed in this paper.展开更多
Complex event processing (CEP) can extract meaningful events for real-time locating system (RTLS) applications. To identify complex event accurately in RTLS, we propose a new RFID complex event processing method GEEP,...Complex event processing (CEP) can extract meaningful events for real-time locating system (RTLS) applications. To identify complex event accurately in RTLS, we propose a new RFID complex event processing method GEEP, which is based on the timed automata (TA) theory. By devising RFID locating application into complex events, we model the timing diagram of RFID data streams based on the TA. We optimize the constraint of the event streams and propose a novel method to derive the constraint between objects, as well as the constraint between object and location. Experiments prove the proposed method reduces the cost of RFID complex event processing, and improves the efficiency of the RTLS.展开更多
This paper studies on the Partial Discharge (PD) Locating System based on a mobile array of ultra-high frequency (UHF) antennas and a vehicle-mounted PD locating system is established. The system consists of omni-dire...This paper studies on the Partial Discharge (PD) Locating System based on a mobile array of ultra-high frequency (UHF) antennas and a vehicle-mounted PD locating system is established. The system consists of omni-directional antenna array for receiving UHF PD signals, a pre-processing circuit for signal amplification and filtering and the high- speed acquisition and control unit of PD pulse signals. The developed locating system is able to simultaneously record the PD pulse signals received by the antenna array. By assessing the time difference of arrival (TDOA), the two-dimensional hyperbolic locating model quickly locates the PD source. Based on the software developed by LabVIEW, it is also possible to display, store and further analyze the acquired signals. Through the simulation of PD signals and the locating experiments with the system, it is proved that the PD locating system possesses the features of rapidity and precision in determining the bearing of PD source.展开更多
Using the acoustic emission locating technology to monitor the health of the structure is important for ensuring the continuous and healthy operation of the complex engineering structures and large mechanical equipmen...Using the acoustic emission locating technology to monitor the health of the structure is important for ensuring the continuous and healthy operation of the complex engineering structures and large mechanical equipment. In this paper, four fiber Bragg grating(FBG) sensors are used to establish the sensor array to locate the acoustic emission source. Firstly, the nonlinear locating equations are established based on the principle of acoustic emission, and the solution of these equations is transformed into an optimization problem. Secondly, time difference extraction algorithm based on the phase transform(PHAT) weighted generalized cross correlation provides the necessary conditions for the accurate localization. Finally, the genetic algorithm(GA) is used to solve the optimization model. In this paper, twenty points are tested in the marble plate surface, and the results show that the absolute locating error is within the range of 10 mm, which proves the accuracy of this locating method.展开更多
Gauss radial basis functions(GRBF)are frequently employed in data fitting and machine learning.Their linear independence property can theoretically guarantee the avoidance of data redundancy.In this paper,one of the m...Gauss radial basis functions(GRBF)are frequently employed in data fitting and machine learning.Their linear independence property can theoretically guarantee the avoidance of data redundancy.In this paper,one of the main contributions is proving this property using linear algebra instead of profound knowledge.This makes it easy to read and understand this fundamental fact.The proof of linear independence of a set of Gauss functions relies on the constructing method for one-dimensional space and on the deducing method for higher dimensions.Additionally,under the condition of preserving the same moments between the original function and interpolating function,both the interpolating existence and uniqueness are proven for GRBF in one-dimensional space.The final work demonstrates the application of the GRBF method to locate lunar olivine.By combining preprocessed data using GRBF with the removing envelope curve method,a program is created to find the position of lunar olivine based on spectrum data,and the numerical experiment shows that it is an effective scheme.展开更多
A conventional non-computerized numerical control （CNC） machine is updated by mounting a six degree-of-free （DOF） parallel mechanism on it, thus obtaining a new CNC one. The structure of this CNC milling machine i...A conventional non-computerized numerical control （CNC） machine is updated by mounting a six degree-of-free （DOF） parallel mechanism on it, thus obtaining a new CNC one. The structure of this CNC milling machine is introduced, and the workpiece locating system and the post processing system of the cutter location （CL） data file are analyzed. The new machine has advantages of low costs, simple structure, good rigidity, and high precision. It is easy to be transformed and used to process the workpiece with a complex surface.展开更多
Fire rescue challenges and solutions have evolved from straightfor-ward plane rescue to encompass 3D space due to the rise of high-rise city buildings.Hence,this study facilitates a system with quick and simplified on...Fire rescue challenges and solutions have evolved from straightfor-ward plane rescue to encompass 3D space due to the rise of high-rise city buildings.Hence,this study facilitates a system with quick and simplified on-site launching and generates real-time location data,enabling fire rescuers to arrive at the intended spot faster and correctly for effective and precise rescue.Auto-positioning with step-by-step instructions is proposed when launching the locating system,while no extra measuring instrument like Total Station(TS)is needed.Real-time location tracking is provided via a 3D space real-time locating system(RTLS)constructed using Ultra-wide Bandwidth technology(UWB),which requires electromagnetic waves to pass through concrete walls.A hybrid weighted least squares with a time difference of arrival(WLS/TDOA)positioning method is proposed to address real path-tracking issues in 3D space and to meet RTLS requirements for quick computing in real-world applications.The 3D WLS/TDOA algorithm is theoretically constructed with the Cramer-Rao lower bound(CRLB).The computing complexity is reduced to the lower bound for embedded hardware to directly compute the time differential of the arriving signals using the time-to-digital converter(TDC).The results of the experiments show that the errors are controlled when the positioning algorithm is applied in various complicated situations to fulfill the requirements of engineering applications.The statistical analysis of the data reveals that the proposed UWB RTLS auto-positioning system can track target tags with an accuracy of 0.20 m.展开更多
Here is reported an iteration method, which corrects the coordinates of an underwater moving target obtained by a hyperbolic locating system with a short-baseline plane array when the sound velocity varies with depth....Here is reported an iteration method, which corrects the coordinates of an underwater moving target obtained by a hyperbolic locating system with a short-baseline plane array when the sound velocity varies with depth. A series of differential difference equations are used for determining the iterative values. The calculated results show that under the same conditions, the location error is about several meters or tens of meters without correction and less than 0.5 m with correction. The method can be applied to various types of arrays.展开更多
A time-of-arrival(TOA) system based on GPS technology for locating VHF radiation sources from lightning has been developed and used in observation sites in the northern Shandong Province,China.The 3D images of the lig...A time-of-arrival(TOA) system based on GPS technology for locating VHF radiation sources from lightning has been developed and used in observation sites in the northern Shandong Province,China.The 3D images of the lightning progression have been obtained successfully for the first time in China.The 3D-channel evolutions of typical negative CG,positive CG and IC lightning flashes have been discussed together with the data of fast electric field change.It was found that significant differences existed between the negative and positive CG lightning flashes in terms of the initiation and propagation of the radiation sources.The preliminary breakdown of a negative CG lightning flash propagated at a speed about 5.2×104 m/s.The stepped leader of negative CG lightning flashes was trigged by negative initial breakdown.Thereafter,it propagated downward at a speed of 1.3×105 m/s.The initial process of the positive CG lightning flashes was also a propagation process of negative streamer.These streamers propagated dominantly horizontally in the positive charge region and accumulated positive charges at the origin of the lightning,and as a consequence,initiated downward positive streamers.A new type of lightning discharge that was triggered by a narrow bipolar pulse(NBP) is discussed in this study.The NBP was originated at altitude of about 10.5 km in the upper positive charge region.As a distinct difference from normal IC flash,its channels extended horizontally all around and produced a lot of radiation sources.The source power of the NBP could approach 16.7 kW,which is much greater than that of normal lightning discharge ranging between 100 mW and 500 W.The 3D propagation of this new type of lightning discharge was observed and obtained for the first time in China.The possible initiation mechanism of this new type of light-ning is discussed here.展开更多
Based on the VHF lightning locating system,a three-dimensional-space cell-gridded approach is used to extract the lighting channel and calculate the length of the channel.Through clustering of the located radiation so...Based on the VHF lightning locating system,a three-dimensional-space cell-gridded approach is used to extract the lighting channel and calculate the length of the channel.Through clustering of the located radiation sources and then extracting the lightning channel,it can accurately obtain the length of the channel.To validate the feasibility of the approach,a simulation experiment is designed,and it shows the length error is no more than 10%.The relationship between the NO production of per unit arc length and atmospheric pressure obtained in laboratory is applied to the NOX production of per unit flash length at different altitudes in this paper.The channel length and the NOX production of 11 negative cloud-to-ground flashes and 59 intracloud flashes in an isolated thunderstorm in the northeastern Qinghai-Tibet Plateau are calculated.The results show that the average channel lengths of per cloud-to-ground and intracloud flash are 28.9 and 22.3 km respectively;the average NOX productions of per cloud-to-ground and intracloud flash are 1.89×1025 and 0.42×1025 molecules,respectively.展开更多
An integrated method for identifying the propagation of multi-loop process oscillations and their source location is proposed in this paper. Oscillatory process loop variables are automatically selected based on the c...An integrated method for identifying the propagation of multi-loop process oscillations and their source location is proposed in this paper. Oscillatory process loop variables are automatically selected based on the component-related ratio index and a mixing matrix, both of which are obtained in data preprocessing by spectral independent component analysis. The complex causality among oscillatory process variables is then revealed by Granger causality test and is visualized in the form of causality diagram. The simplification of causal connectivity in the diagram is performed according to the understanding of process knowledge and the final simplest causality diagram, which represents the main oscillation propagation paths, is achieved by the automated cutting-off thresh-old search, with which less significant causality pathways are filtered out. The source of the oscillation disturbance can be identified intuitively through the final causality diagram. Both simulated and real plant data tests are presented to demonstrate the effectiveness and feasibility of the proposed method.展开更多
It is currently prevalent to locate faults for a satellite power system based on an expert system, not utilizing all the available information provided by tests. The casual network model for a satellite power system i...It is currently prevalent to locate faults for a satellite power system based on an expert system, not utilizing all the available information provided by tests. The casual network model for a satellite power system is presented. Considerations for failure probability of each component of the power system, the cost of applying each test, the influence of a precedent test result on the next test selection, and an optimal sequential testing algorithm for fault location is presented. This program is applied to locate the failure component of the power system of a satellite. The results show this program is very effective and it is very fast to generate an optimal diagnosis tree.展开更多
A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengineering (LIBB), Chinese Academy of Sciences (CAS). At the CAS-LIBB microbeam facility, we have developed protocols to ...A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengineering (LIBB), Chinese Academy of Sciences (CAS). At the CAS-LIBB microbeam facility, we have developed protocols to place exact numbers of charged particles through nuclear centroids of cells, at defined positions in the cytoplasm relative to the nucleus, and through defined fractions of cells in a population. In this paper, we address the methods for nucleus, cytoplasm and bystander (either a single or an exact number of ions is delivered to a certain percentage of cells in a population to study the bystander effects of radiation) irradiation in detail from the precision of target finding and cell locating in the image analysis system. Moreover, for cells touching slightly in an image, a watershed method is used to separate these touching objects; after that, the number of objects in an image is counted accurately and the irradiation points are located precisely.展开更多
OBJECTIVE:To propose an automatic acupuncture robot system for performing acupuncture operations.METHODS:The acupuncture robot system consists of three components:automatic acupoint localization,acupuncture manipulati...OBJECTIVE:To propose an automatic acupuncture robot system for performing acupuncture operations.METHODS:The acupuncture robot system consists of three components:automatic acupoint localization,acupuncture manipulations,and De Qi sensation detection.The OptiTrack motion capture system is used to locate acupoints,which are then translated into coordinates in the robot control system.A flexible collaborative robot with an intelligent gripper is then used to perform acupuncture manipulations with high precision.In addition,a De Qi sensation detection system is proposed to evaluate the effect of acupuncture.To verify the stability of the designed acupuncture robot,acupoints'coordinates localized by the acupuncture robot are compared with the Gold Standard labeled by a professional acupuncturist using significant level tests.RESULTS:Through repeated experiments for eight acupoints,the acupuncture robot achieved a positioning error within 3.3 mm,which is within the allowable range of needle extraction and acupoint insertion.During needle insertion,the robot arm followed the prescribed trajectory with a mean deviation distance of 0.02 mm and a deviation angle of less than 0.15°.The results of the lifting thrusting operation in the Xingzhen process show that the mean acupuncture depth error of the designed acupuncture robot is approximately 2 mm,which is within the recommended depth range for the Xingzhen operation.In addition,the average detection accuracy of the De Qi keywords is 94.52%,which meets the requirements of acupuncture effect testing for different dialects.CONCLUSION:The proposed acupuncture robot system streamlines the acupuncture process,increases efficiency,and reduces practitioner fatigue,while also allowing for the quantification of acupuncture manipulations and evaluation of therapeutic effects.The development of an acupuncture robot system has the potential to revolutionize low back pain treatment and improve patient outcomes.展开更多
Transmission tower-line systems(TTLSs)play a crucial role in the long-distance transmission of electrical energy,often necessitating their crossing through active fault areas.However,previous studies have given limite...Transmission tower-line systems(TTLSs)play a crucial role in the long-distance transmission of electrical energy,often necessitating their crossing through active fault areas.However,previous studies have given limited attention to the seismic performance of fault-crossing transmission TTLSs,particularly in terms of considering the impact of permanent ground motion displacements(PGMDs).This study attempts to address this concern by evaluating the seismic performance of TTLSs exposed to fault earthquakes.Three strike-slip ground motions are carefully selected,and the corresponding PGMDs are accurately replicated through baseline adjustment.A meticulously designed and fabricated reduced-scale experimental model of a TTLS is then employed to investigate the influence of the fault crossing location(FCL)on its seismic performance.The shake table tests conducted unequivocally demonstrate that PGMDs significantly amplify the seismic responses of the TTLS and identify the most unfavorable FCL.Furthermore,a finite element model(FEM)is developed and its accuracy is validated by comparing it with the experimental results.Parametric analyses are conducted to explore the effects of fault crossing angles(FCAs)and PGMD amplitudes on the seismic performances of TTLSs.This study is expected to contribute valuable insights for the seismic design and performance analysis of TTLSs crossing fault areas.展开更多
The carbon emissions and cost during the construction phase are significant contributors to the oilfield lifecycle.As oilfields enter the late stage,the adaptability of facilities decreases.To achieve sustainable deve...The carbon emissions and cost during the construction phase are significant contributors to the oilfield lifecycle.As oilfields enter the late stage,the adaptability of facilities decreases.To achieve sustainable development,oilfield reconstruction was usually conducted in discrete rather than continuous space.Motivated by economic and sustainability goals,a 3-phase heuristic model for oilfield reconstruction was developed to mine potential locations in continuous space.In phase 1,considering the process characteristics of the oil and gas gathering system,potential locations were mined in continuous space.In phase 2,incorporating comprehensive reconstruction measures,a reconstruction model was established in discrete space.In phase 3,the topology was further adjusted in continuous space.Subsequently,the model was transformed into a single-objective mixed integer linear programming model using the augmented ε-constraint method.Numerical experiments revealed that the small number of potential locations could effectively reduce the reconstruction cost,and the quality of potential locations mined in phase 1 surpassed those generated in random or grid form.Case studies showed that cost and carbon emissions for a new block were reduced by up to 10.45% and 7.21 %,respectively.These reductions were because the potential locations mined in 1P reduced the number of metering stations,and 3P adjusted the locations of metering stations in continuous space to shorten the pipeline length.For an old oilfield,the load and connection ratios of the old metering station increased to 89.7% and 94.9%,respectively,enhancing operation efficiency.Meanwhile,recycling facilitated the diversification of reconstruction measures and yielded a profit of 582,573 ¥,constituting 5.56% of the total cost.This study adopted comprehensive reconstruction measures and tapped into potential reductions in cost and carbon emissions for oilfield reconstruction,offering valuable insights for future oilfield design and construction.展开更多
In this paper,we propose STPLF,which stands for the short-term forecasting of locational marginal price components,including the forecasting of non-conforming hourly net loads.The volatility of transmission-level hour...In this paper,we propose STPLF,which stands for the short-term forecasting of locational marginal price components,including the forecasting of non-conforming hourly net loads.The volatility of transmission-level hourly locational marginal prices(LMPs)is caused by several factors,including weather data,hourly gas prices,historical hourly loads,and market prices.In addition,variations of non-conforming net loads,which are affected by behind-the-meter distributed energy resources(DERs)and retail customer loads,could have a major impact on the volatility of hourly LMPs,as bulk grid operators have limited visibility of such retail-level resources.We propose a fusion forecasting model for the STPLF,which uses machine learning and deep learning methods to forecast non-conforming loads and respective hourly prices.Additionally,data preprocessing and feature extraction are used to increase the accuracy of the STPLF.The proposed STPLF model also includes a post-processing stage for calculating the probability of hourly LMP spikes.We use a practical set of data to analyze the STPLF results and validate the proposed probabilistic method for calculating the LMP spikes.展开更多
The literature on multi-attribute optimization for renewable energy source(RES)placement in deregulated power markets is extensive and diverse in methodology.This study focuses on the most relevant publications direct...The literature on multi-attribute optimization for renewable energy source(RES)placement in deregulated power markets is extensive and diverse in methodology.This study focuses on the most relevant publications directly addressing the research problem at hand.Similarly,while the body of work on optimal location and sizing of renewable energy generators(REGs)in balanced distribution systems is substantial,only the most pertinent sources are cited,aligning closely with the study’s objective function.A comprehensive literature review reveals several key research areas:RES integration,RES-related optimization techniques,strategic placement of wind and solar generation,and RES promotion in deregulated powermarkets,particularly within transmission systems.Furthermore,the optimal location and sizing of REGs in both balanced and unbalanced distribution systems have been extensively studied.RESs demonstrate significant potential for standalone applications in remote areas lacking conventional transmission and distribution infrastructure.Also presents a thorough review of current modeling and optimization approaches for RES-based distribution system location and sizing.Additionally,it examines the optimal positioning,sizing,and performance of hybrid and standalone renewable energy systems.This paper provides a comprehensive review of current modeling and optimization approaches for the location and sizing of Renewable Energy Sources(RESs)in distribution systems,focusing on both balanced and unbalanced networks.展开更多
With a pair of antennas spaced apart, an airborne passive location system measures phase differences of emitting signals. Regarded as cyclic ambiguities, the moduli of the measurements traditionally are resolved by ad...With a pair of antennas spaced apart, an airborne passive location system measures phase differences of emitting signals. Regarded as cyclic ambiguities, the moduli of the measurements traditionally are resolved by adding more antenna elements. This paper models the cyclic ambiguity as a component of the system state, of which the observability is analyzed and compared to that of the bear- ings-only passive location system. It is shown that the necessary and sufficient observability condition for the bearings-only passive location system is only the necessary observability condition for the passive location system with phase difference measurements, and that when the system state is observable, the cyclic ambiguities can be estimated by accumulating the phase difference measurements, thereby making the observer able to locate the emitter with high-precision.展开更多
基金Aeronautical Science Foundation of China (2007ZC53030)
文摘As an important parameter in the single airborne passive locating system, the rate of phase difference change contains range information of the radio emitter. Taking single carrier sine pulse signals as an example, this article illustrates the principle of passive location through measurement of rates of phase difference change and analyzes the structure of measurement errors. On the basis of the Cramér-Rao lower bound (CRLB), an algorithm associated with time-chips is proposed to determine the rates of pha...
文摘Short baseline system (SBL), which is a kind of underwater acoustic locating technology, has widely applicable value. In order to examine the capability of ship model design, the ship model experimentation should have high accuracy. This paper focuses on the key techniques of high accuracy locating system, including high accuracy sub-array position emendation, divisional locating, anti multi-path interference measure, etc. Experiments show that the SBL locating systems has received the satisfying effect owing to these key techniques proposed in this paper.
文摘Complex event processing (CEP) can extract meaningful events for real-time locating system (RTLS) applications. To identify complex event accurately in RTLS, we propose a new RFID complex event processing method GEEP, which is based on the timed automata (TA) theory. By devising RFID locating application into complex events, we model the timing diagram of RFID data streams based on the TA. We optimize the constraint of the event streams and propose a novel method to derive the constraint between objects, as well as the constraint between object and location. Experiments prove the proposed method reduces the cost of RFID complex event processing, and improves the efficiency of the RTLS.
文摘This paper studies on the Partial Discharge (PD) Locating System based on a mobile array of ultra-high frequency (UHF) antennas and a vehicle-mounted PD locating system is established. The system consists of omni-directional antenna array for receiving UHF PD signals, a pre-processing circuit for signal amplification and filtering and the high- speed acquisition and control unit of PD pulse signals. The developed locating system is able to simultaneously record the PD pulse signals received by the antenna array. By assessing the time difference of arrival (TDOA), the two-dimensional hyperbolic locating model quickly locates the PD source. Based on the software developed by LabVIEW, it is also possible to display, store and further analyze the acquired signals. Through the simulation of PD signals and the locating experiments with the system, it is proved that the PD locating system possesses the features of rapidity and precision in determining the bearing of PD source.
基金supported by the National Natural Science Foundation of China(No.41472260)the Fundamental Research Funds of Shandong University(No.2016JC012)the Young Scholars Program of Shandong University(No.2016WLJH30)
文摘Using the acoustic emission locating technology to monitor the health of the structure is important for ensuring the continuous and healthy operation of the complex engineering structures and large mechanical equipment. In this paper, four fiber Bragg grating(FBG) sensors are used to establish the sensor array to locate the acoustic emission source. Firstly, the nonlinear locating equations are established based on the principle of acoustic emission, and the solution of these equations is transformed into an optimization problem. Secondly, time difference extraction algorithm based on the phase transform(PHAT) weighted generalized cross correlation provides the necessary conditions for the accurate localization. Finally, the genetic algorithm(GA) is used to solve the optimization model. In this paper, twenty points are tested in the marble plate surface, and the results show that the absolute locating error is within the range of 10 mm, which proves the accuracy of this locating method.
基金Supported by the National Basic Research Program of China(2012CB025904)Zhengzhou Shengda University of Economics,Business and Management(SD-YB2025085)。
文摘Gauss radial basis functions(GRBF)are frequently employed in data fitting and machine learning.Their linear independence property can theoretically guarantee the avoidance of data redundancy.In this paper,one of the main contributions is proving this property using linear algebra instead of profound knowledge.This makes it easy to read and understand this fundamental fact.The proof of linear independence of a set of Gauss functions relies on the constructing method for one-dimensional space and on the deducing method for higher dimensions.Additionally,under the condition of preserving the same moments between the original function and interpolating function,both the interpolating existence and uniqueness are proven for GRBF in one-dimensional space.The final work demonstrates the application of the GRBF method to locate lunar olivine.By combining preprocessed data using GRBF with the removing envelope curve method,a program is created to find the position of lunar olivine based on spectrum data,and the numerical experiment shows that it is an effective scheme.
文摘A conventional non-computerized numerical control （CNC） machine is updated by mounting a six degree-of-free （DOF） parallel mechanism on it, thus obtaining a new CNC one. The structure of this CNC milling machine is introduced, and the workpiece locating system and the post processing system of the cutter location （CL） data file are analyzed. The new machine has advantages of low costs, simple structure, good rigidity, and high precision. It is easy to be transformed and used to process the workpiece with a complex surface.
文摘Fire rescue challenges and solutions have evolved from straightfor-ward plane rescue to encompass 3D space due to the rise of high-rise city buildings.Hence,this study facilitates a system with quick and simplified on-site launching and generates real-time location data,enabling fire rescuers to arrive at the intended spot faster and correctly for effective and precise rescue.Auto-positioning with step-by-step instructions is proposed when launching the locating system,while no extra measuring instrument like Total Station(TS)is needed.Real-time location tracking is provided via a 3D space real-time locating system(RTLS)constructed using Ultra-wide Bandwidth technology(UWB),which requires electromagnetic waves to pass through concrete walls.A hybrid weighted least squares with a time difference of arrival(WLS/TDOA)positioning method is proposed to address real path-tracking issues in 3D space and to meet RTLS requirements for quick computing in real-world applications.The 3D WLS/TDOA algorithm is theoretically constructed with the Cramer-Rao lower bound(CRLB).The computing complexity is reduced to the lower bound for embedded hardware to directly compute the time differential of the arriving signals using the time-to-digital converter(TDC).The results of the experiments show that the errors are controlled when the positioning algorithm is applied in various complicated situations to fulfill the requirements of engineering applications.The statistical analysis of the data reveals that the proposed UWB RTLS auto-positioning system can track target tags with an accuracy of 0.20 m.
文摘Here is reported an iteration method, which corrects the coordinates of an underwater moving target obtained by a hyperbolic locating system with a short-baseline plane array when the sound velocity varies with depth. A series of differential difference equations are used for determining the iterative values. The calculated results show that under the same conditions, the location error is about several meters or tens of meters without correction and less than 0.5 m with correction. The method can be applied to various types of arrays.
基金supported by National Natural Science Foundation of China (Grant No.40775004)Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No.KZCX2-YW-206-2)the R & D Special Fund for Public Welfare Industry (meteorology) (Grant No.GYHY2007622)
文摘A time-of-arrival(TOA) system based on GPS technology for locating VHF radiation sources from lightning has been developed and used in observation sites in the northern Shandong Province,China.The 3D images of the lightning progression have been obtained successfully for the first time in China.The 3D-channel evolutions of typical negative CG,positive CG and IC lightning flashes have been discussed together with the data of fast electric field change.It was found that significant differences existed between the negative and positive CG lightning flashes in terms of the initiation and propagation of the radiation sources.The preliminary breakdown of a negative CG lightning flash propagated at a speed about 5.2×104 m/s.The stepped leader of negative CG lightning flashes was trigged by negative initial breakdown.Thereafter,it propagated downward at a speed of 1.3×105 m/s.The initial process of the positive CG lightning flashes was also a propagation process of negative streamer.These streamers propagated dominantly horizontally in the positive charge region and accumulated positive charges at the origin of the lightning,and as a consequence,initiated downward positive streamers.A new type of lightning discharge that was triggered by a narrow bipolar pulse(NBP) is discussed in this study.The NBP was originated at altitude of about 10.5 km in the upper positive charge region.As a distinct difference from normal IC flash,its channels extended horizontally all around and produced a lot of radiation sources.The source power of the NBP could approach 16.7 kW,which is much greater than that of normal lightning discharge ranging between 100 mW and 500 W.The 3D propagation of this new type of lightning discharge was observed and obtained for the first time in China.The possible initiation mechanism of this new type of light-ning is discussed here.
基金supported by the National Natural Science Foundation of Chi-na(Grant Nos.41075002,40775004,41030960)R&D Special Fund for Public Welfare Industry(Meteorology)(Grant No.GYHY201006005-03)
文摘Based on the VHF lightning locating system,a three-dimensional-space cell-gridded approach is used to extract the lighting channel and calculate the length of the channel.Through clustering of the located radiation sources and then extracting the lightning channel,it can accurately obtain the length of the channel.To validate the feasibility of the approach,a simulation experiment is designed,and it shows the length error is no more than 10%.The relationship between the NO production of per unit arc length and atmospheric pressure obtained in laboratory is applied to the NOX production of per unit flash length at different altitudes in this paper.The channel length and the NOX production of 11 negative cloud-to-ground flashes and 59 intracloud flashes in an isolated thunderstorm in the northeastern Qinghai-Tibet Plateau are calculated.The results show that the average channel lengths of per cloud-to-ground and intracloud flash are 28.9 and 22.3 km respectively;the average NOX productions of per cloud-to-ground and intracloud flash are 1.89×1025 and 0.42×1025 molecules,respectively.
基金Supported by the National Natural Science Foundation of China （60974061）.
文摘An integrated method for identifying the propagation of multi-loop process oscillations and their source location is proposed in this paper. Oscillatory process loop variables are automatically selected based on the component-related ratio index and a mixing matrix, both of which are obtained in data preprocessing by spectral independent component analysis. The complex causality among oscillatory process variables is then revealed by Granger causality test and is visualized in the form of causality diagram. The simplification of causal connectivity in the diagram is performed according to the understanding of process knowledge and the final simplest causality diagram, which represents the main oscillation propagation paths, is achieved by the automated cutting-off thresh-old search, with which less significant causality pathways are filtered out. The source of the oscillation disturbance can be identified intuitively through the final causality diagram. Both simulated and real plant data tests are presented to demonstrate the effectiveness and feasibility of the proposed method.
基金Sponsored by the National High Technology Research and Development Program of China(Grant No.2002AA721063).
文摘It is currently prevalent to locate faults for a satellite power system based on an expert system, not utilizing all the available information provided by tests. The casual network model for a satellite power system is presented. Considerations for failure probability of each component of the power system, the cost of applying each test, the influence of a precedent test result on the next test selection, and an optimal sequential testing algorithm for fault location is presented. This program is applied to locate the failure component of the power system of a satellite. The results show this program is very effective and it is very fast to generate an optimal diagnosis tree.
基金The project supported by the National Major Technologies R&D Program of China for the 10th Five-Year Plan Period (No.2001BA302B)the magnitude instrument development project of the Chinese Academy of Sciences, the National Natural Science Foundation of China (No. 19875054)the National Science Fund for Distinguished Young Scholars (No. 10225526)
文摘A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengineering (LIBB), Chinese Academy of Sciences (CAS). At the CAS-LIBB microbeam facility, we have developed protocols to place exact numbers of charged particles through nuclear centroids of cells, at defined positions in the cytoplasm relative to the nucleus, and through defined fractions of cells in a population. In this paper, we address the methods for nucleus, cytoplasm and bystander (either a single or an exact number of ions is delivered to a certain percentage of cells in a population to study the bystander effects of radiation) irradiation in detail from the precision of target finding and cell locating in the image analysis system. Moreover, for cells touching slightly in an image, a watershed method is used to separate these touching objects; after that, the number of objects in an image is counted accurately and the irradiation points are located precisely.
基金Modernization of Traditional Chinese Medicine Project of National Key R&D Program of China:The construction of the theoretical system of Traditional Chinese Medicine nonpharmacological therapy based on body surface stimulation(2023YFC3502704)Sichuan Provincial Science and Technology Program Project:Research and Development of Chinese Medicine Intelligent Tongue Diagnosis Equipment for Digestive System Chinese Medicine Advantageous Diseases(2023YFS0327)+2 种基金Research and Development of Chinese Medicine Intelligent Detection System for Intestinal Functions(2024YFFK0044)Research and Application of Chinese Medicine Diagnosis and Treatment Program for Herpes Zoster Treated by Shu Pai Fire Acupuncture(2024YFFK0089)Major Research and Development Project of The China Academy of Chinese Medical Sciences Innovation:Construction and application of the theoretical research mode of Traditional Chinese Medicine diagnosis and treatment of modern diseases(CI2021A00104)。
文摘OBJECTIVE:To propose an automatic acupuncture robot system for performing acupuncture operations.METHODS:The acupuncture robot system consists of three components:automatic acupoint localization,acupuncture manipulations,and De Qi sensation detection.The OptiTrack motion capture system is used to locate acupoints,which are then translated into coordinates in the robot control system.A flexible collaborative robot with an intelligent gripper is then used to perform acupuncture manipulations with high precision.In addition,a De Qi sensation detection system is proposed to evaluate the effect of acupuncture.To verify the stability of the designed acupuncture robot,acupoints'coordinates localized by the acupuncture robot are compared with the Gold Standard labeled by a professional acupuncturist using significant level tests.RESULTS:Through repeated experiments for eight acupoints,the acupuncture robot achieved a positioning error within 3.3 mm,which is within the allowable range of needle extraction and acupoint insertion.During needle insertion,the robot arm followed the prescribed trajectory with a mean deviation distance of 0.02 mm and a deviation angle of less than 0.15°.The results of the lifting thrusting operation in the Xingzhen process show that the mean acupuncture depth error of the designed acupuncture robot is approximately 2 mm,which is within the recommended depth range for the Xingzhen operation.In addition,the average detection accuracy of the De Qi keywords is 94.52%,which meets the requirements of acupuncture effect testing for different dialects.CONCLUSION:The proposed acupuncture robot system streamlines the acupuncture process,increases efficiency,and reduces practitioner fatigue,while also allowing for the quantification of acupuncture manipulations and evaluation of therapeutic effects.The development of an acupuncture robot system has the potential to revolutionize low back pain treatment and improve patient outcomes.
基金Shandong Provincial Natural Science Foundation for Distinguished Young Scholars under Grant No.ZR2022JQ27the Taishan Scholars Program
文摘Transmission tower-line systems(TTLSs)play a crucial role in the long-distance transmission of electrical energy,often necessitating their crossing through active fault areas.However,previous studies have given limited attention to the seismic performance of fault-crossing transmission TTLSs,particularly in terms of considering the impact of permanent ground motion displacements(PGMDs).This study attempts to address this concern by evaluating the seismic performance of TTLSs exposed to fault earthquakes.Three strike-slip ground motions are carefully selected,and the corresponding PGMDs are accurately replicated through baseline adjustment.A meticulously designed and fabricated reduced-scale experimental model of a TTLS is then employed to investigate the influence of the fault crossing location(FCL)on its seismic performance.The shake table tests conducted unequivocally demonstrate that PGMDs significantly amplify the seismic responses of the TTLS and identify the most unfavorable FCL.Furthermore,a finite element model(FEM)is developed and its accuracy is validated by comparing it with the experimental results.Parametric analyses are conducted to explore the effects of fault crossing angles(FCAs)and PGMD amplitudes on the seismic performances of TTLSs.This study is expected to contribute valuable insights for the seismic design and performance analysis of TTLSs crossing fault areas.
基金supported by the National Natural Science Foundation of China (Grant No.52174065)the National Natural Science Foundation of China (Grant No.52304071)+1 种基金China University of Petroleum,Beijing (Grant No.ZX20220040)MOE Key Laboratory of Petroleum Engineering (China University of Petroleum,No.2462024PTJS002)。
文摘The carbon emissions and cost during the construction phase are significant contributors to the oilfield lifecycle.As oilfields enter the late stage,the adaptability of facilities decreases.To achieve sustainable development,oilfield reconstruction was usually conducted in discrete rather than continuous space.Motivated by economic and sustainability goals,a 3-phase heuristic model for oilfield reconstruction was developed to mine potential locations in continuous space.In phase 1,considering the process characteristics of the oil and gas gathering system,potential locations were mined in continuous space.In phase 2,incorporating comprehensive reconstruction measures,a reconstruction model was established in discrete space.In phase 3,the topology was further adjusted in continuous space.Subsequently,the model was transformed into a single-objective mixed integer linear programming model using the augmented ε-constraint method.Numerical experiments revealed that the small number of potential locations could effectively reduce the reconstruction cost,and the quality of potential locations mined in phase 1 surpassed those generated in random or grid form.Case studies showed that cost and carbon emissions for a new block were reduced by up to 10.45% and 7.21 %,respectively.These reductions were because the potential locations mined in 1P reduced the number of metering stations,and 3P adjusted the locations of metering stations in continuous space to shorten the pipeline length.For an old oilfield,the load and connection ratios of the old metering station increased to 89.7% and 94.9%,respectively,enhancing operation efficiency.Meanwhile,recycling facilitated the diversification of reconstruction measures and yielded a profit of 582,573 ¥,constituting 5.56% of the total cost.This study adopted comprehensive reconstruction measures and tapped into potential reductions in cost and carbon emissions for oilfield reconstruction,offering valuable insights for future oilfield design and construction.
基金funded in part by Grant No.DF-091-135-1441 from the Deanship of Scientific Research(DSR)at King Abdulaziz University in Saudi Arabia.
文摘In this paper,we propose STPLF,which stands for the short-term forecasting of locational marginal price components,including the forecasting of non-conforming hourly net loads.The volatility of transmission-level hourly locational marginal prices(LMPs)is caused by several factors,including weather data,hourly gas prices,historical hourly loads,and market prices.In addition,variations of non-conforming net loads,which are affected by behind-the-meter distributed energy resources(DERs)and retail customer loads,could have a major impact on the volatility of hourly LMPs,as bulk grid operators have limited visibility of such retail-level resources.We propose a fusion forecasting model for the STPLF,which uses machine learning and deep learning methods to forecast non-conforming loads and respective hourly prices.Additionally,data preprocessing and feature extraction are used to increase the accuracy of the STPLF.The proposed STPLF model also includes a post-processing stage for calculating the probability of hourly LMP spikes.We use a practical set of data to analyze the STPLF results and validate the proposed probabilistic method for calculating the LMP spikes.
文摘The literature on multi-attribute optimization for renewable energy source(RES)placement in deregulated power markets is extensive and diverse in methodology.This study focuses on the most relevant publications directly addressing the research problem at hand.Similarly,while the body of work on optimal location and sizing of renewable energy generators(REGs)in balanced distribution systems is substantial,only the most pertinent sources are cited,aligning closely with the study’s objective function.A comprehensive literature review reveals several key research areas:RES integration,RES-related optimization techniques,strategic placement of wind and solar generation,and RES promotion in deregulated powermarkets,particularly within transmission systems.Furthermore,the optimal location and sizing of REGs in both balanced and unbalanced distribution systems have been extensively studied.RESs demonstrate significant potential for standalone applications in remote areas lacking conventional transmission and distribution infrastructure.Also presents a thorough review of current modeling and optimization approaches for RES-based distribution system location and sizing.Additionally,it examines the optimal positioning,sizing,and performance of hybrid and standalone renewable energy systems.This paper provides a comprehensive review of current modeling and optimization approaches for the location and sizing of Renewable Energy Sources(RESs)in distribution systems,focusing on both balanced and unbalanced networks.
文摘With a pair of antennas spaced apart, an airborne passive location system measures phase differences of emitting signals. Regarded as cyclic ambiguities, the moduli of the measurements traditionally are resolved by adding more antenna elements. This paper models the cyclic ambiguity as a component of the system state, of which the observability is analyzed and compared to that of the bear- ings-only passive location system. It is shown that the necessary and sufficient observability condition for the bearings-only passive location system is only the necessary observability condition for the passive location system with phase difference measurements, and that when the system state is observable, the cyclic ambiguities can be estimated by accumulating the phase difference measurements, thereby making the observer able to locate the emitter with high-precision.
