The spread of tuberculosis(TB),especially multidrug-resistant TB and extensively drug-resistant TB,has strongly motivated the research and development of new anti-TB drugs.New strategies to facilitate drug combination...The spread of tuberculosis(TB),especially multidrug-resistant TB and extensively drug-resistant TB,has strongly motivated the research and development of new anti-TB drugs.New strategies to facilitate drug combinations,including pharmacokinetics-guided dose optimization and toxicology studies of first-and second-line anti-TB drugs have also been introduced and recommended.Liquid chromatography-mass spectrometry(LC-MS)has arguably become the gold standard in the analysis of both endo-and exo-genous compounds.This technique has been applied successfully not only for therapeutic drug monitoring(TDM)but also for pharmacometabolomics analysis.TDM improves the effectiveness of treatment,reduces adverse drug reactions,and the likelihood of drug resistance development in TB patients by determining dosage regimens that produce concentrations within the therapeutic target window.Based on TDM,the dose would be optimized individually to achieve favorable outcomes.Pharmacometabolomics is essential in generating and validating hypotheses regarding the metabolism of anti-TB drugs,aiding in the discovery of potential biomarkers for TB diagnostics,treatment monitoring,and outcome evaluation.This article highlighted the current progresses in TDM of anti-TB drugs based on LC-MS bioassay in the last two decades.Besides,we discussed the advantages and disadvantages of this technique in practical use.The pressing need for non-invasive sampling approaches and stability studies of anti-TB drugs was highlighted.Lastly,we provided perspectives on the prospects of combining LC-MS-based TDM and pharmacometabolomics with other advanced strategies(pharmacometrics,drug and vaccine developments,machine learning/artificial intelligence,among others)to encapsulate in an all-inclusive approach to improve treatment outcomes of TB patients.展开更多
Precise point positioning (PPP)-based deformation monitoring scheme is presented for the use in mining deformation monitoring. Within the solutions of daily observation, outliers are detected and removed to avoid any ...Precise point positioning (PPP)-based deformation monitoring scheme is presented for the use in mining deformation monitoring. Within the solutions of daily observation, outliers are detected and removed to avoid any potential misinterpretation of the results and then the deformation can be extracted by the coordinate differences between the two consecutive solutions. Meanwhile, because of the special location of a rover station in mining areas, the satellite geometry may be insufficient for a reasonable PPP solution, and the multipath impact an also be significant. Therefore, it is necessary to predict the satellite geometry before any daily observation. To evaluate the ability of extracting the deformation using the PPP-based method, various quality measures were introduced. The results of three datasets of the same station show that the precision of deformation monitored by PPP can reach up to cm level and even mm level.展开更多
To improve the reliability of the light emitting diode(LED)signal lamp filament current monitoring alarm instrument for metro systems,a new type of hot standby online monitoring apparatus was developed which is based ...To improve the reliability of the light emitting diode(LED)signal lamp filament current monitoring alarm instrument for metro systems,a new type of hot standby online monitoring apparatus was developed which is based on synchronous transmission data(STD)bus technology.In this system,a double hot standby mode can be achieved by adopting bus arbitration.In addition,to detect the effective value of alternating current which is from 0 to 200 mA in the signal lamp lighting circuit,a precision rectifier signal conditioning circuit and an isolated acquisition circuit were designed.This new type of alarm instrument has high detection accuracy and could meet the functional requirements for metro signal systems after comparing it with some industry products that were applied on the spot.展开更多
Solar resource monitoring and evaluation is the foundation of informatization of photovoltaic power station. In 2016, China began to bring in high-precision solar resource monitoring technology which provides reliable...Solar resource monitoring and evaluation is the foundation of informatization of photovoltaic power station. In 2016, China began to bring in high-precision solar resource monitoring technology which provides reliable basic data for the photovoltaic informatization development. This paper systematically sorts out design basis, monitoring elements and system architecture of high-precision monitoring station, and analyzes operation effect of high-precision solar resource monitoring station from performance of solar radiation meter and prediction results of luminous power, which provide important data support for analysis of power generation efficiency of photovoltaic module, prediction of power generation of power station, evaluation of operation effect of power station, etc.展开更多
Monitoring the performance of any structure requires real-time measurements of the change of position of critical points. Different techniques can be used for this purpose, each one offering advantages and disadvantag...Monitoring the performance of any structure requires real-time measurements of the change of position of critical points. Different techniques can be used for this purpose, each one offering advantages and disadvantages. The technique based on satellite positioning systems (GPS, GLONASS and the future GALILEO) seems to be very promising at least for long period structures. The GPS in particular provides sampling rates that are able to track dynamic displacements with high accuracy. Its service ability is independent of atmospheric conditions, temperature variations and visibility of the monitored object. This paper investigates the reliability and accuracy of the measurements of dual frequency GPS receivers. A linear electromagnetic motor moves an object along a given direction. The changes of position are compared witb their estimates as recorded by a GPS receiver, whose antenna is located on the reference object. The comparison is based on sufficiently long records.展开更多
Pest insect monitoring and control is crucial to ensure a safe and profitable crop growth in all plantation types,as well as guarantee food quality and limited use of pesticides.We aim at extending traditional monitor...Pest insect monitoring and control is crucial to ensure a safe and profitable crop growth in all plantation types,as well as guarantee food quality and limited use of pesticides.We aim at extending traditional monitoring by means of traps,by involving the general public in reporting the presence of insects by using smartphones.This includes the largely unexplored problem of detecting insects in images that are taken in noncontrolled conditions.Furthermore,pest insects are,in many cases,extremely similar to other species that are harmless.Therefore,computer vision algorithms must not be fooled by these similar insects,not to raise unmotivated alarms.In this work,we study the capabilities of state-of-the-art(SoA)object detection models based on convolutional neural networks(CNN)for the task of detecting beetle-like pest insects on nonhomogeneous images taken outdoors by different sources.Moreover,we focus on disambiguating a pest insect from similar harmless species.We consider not only detection performance of different models,but also required computational resources.This study aims at providing a baseline model for this kind of tasks.Our results show the suitability of current SoA models for this application,highlighting how FasterRCNN with a MobileNetV3 backbone is a particularly good starting point for accuracy and inference execution latency.This combination provided a mean average precision score of 92.66%that can be considered qualitatively at least as good as the score obtained by other authors that adopted more specific models.展开更多
The mining area deformation monitoring theory and method using precise point positioning (PPP) ambi- guity resolution (AR) were studied, and an ambiguity fixing model with satellite and receiver combina- tion phas...The mining area deformation monitoring theory and method using precise point positioning (PPP) ambi- guity resolution (AR) were studied, and an ambiguity fixing model with satellite and receiver combina- tion phase delay (CPD) was proposed for zero-differenced PPP ambiguity fixing and its corresponding formula derivation was given. The data processing results for I h at six IGS stations in China show that 93% of ambiguities can be fixed within 10 min and all ambiguities can be fixed within 15 min. After ambi- guity fixing, the positioning accuracy is improved by more than 85% in the E and N directions, with abso- lute positioning accuracy reaching millimeter level, and it was improved by 70% in the U direction, reaching centimeter level; the proposed zero-differenced ambiguity fixing model can effectively improve the convergence rate and positioning accuracy in PPP. Data monitoring continuously conducted for half a year at four COPS stations of Shanxi China Coal Pingshuo Group validated the feasibility of using PPP in mining area deformation monitoring.展开更多
The accurate monitoring of optical thin-film thickness is a key technique for depositing optical thin-film. For existing coating equipments, which are low precision and automation level on monitoring thin-film thickne...The accurate monitoring of optical thin-film thickness is a key technique for depositing optical thin-film. For existing coating equipments, which are low precision and automation level on monitoring thin-film thickness, a new photoelectric control and analysis system has been developed. In the new system, main techniques include a photoelectric system with dual-light path, a dual-lock-phase circuit system and a comprehensive digital processing-control-analysis system.The test results of new system show that the static and dynamic stabilities and the control precision of thin-film thickness are extremely increased. The standard deviation of thin-film thickness, which indicates the duplication of thin-film thickness monitoring, is equal to or less than 0.72%. The display resolution limit on reflectivity is 0.02 %. In the system, the linearity of drift is very high, and the static drift ratio approaches zero.展开更多
Predictive Emission Monitoring Systems (PEMS) offer a cost-effective and environmentally friendly alternative to Continuous Emission Monitoring Systems (CEMS) for monitoring pollution from industrial sources. Multiple...Predictive Emission Monitoring Systems (PEMS) offer a cost-effective and environmentally friendly alternative to Continuous Emission Monitoring Systems (CEMS) for monitoring pollution from industrial sources. Multiple regression is one of the fundamental statistical techniques to describe the relationship between dependent and independent variables. This model can be effectively used to develop a PEMS, to estimate the amount of pollution emitted by industrial sources, where the fuel composition and other process-related parameters are available. It often makes them sufficient to predict the emission discharge with acceptable accuracy. In cases where PEMS are accepted as an alternative method to CEMS, which use gas analyzers, they can provide cost savings and substantial benefits for ongoing system support and maintenance. The described mathematical concept is based on the matrix algebra representation in multiple regression involving multiple precision arithmetic techniques. Challenging numerical examples for statistical big data analysis, are investigated. Numerical examples illustrate computational accuracy and efficiency of statistical analysis due to increasing the precision level. The programming language C++ is used for mathematical model implementation. The data for research and development, including the dependent fuel and independent NOx emissions data, were obtained from CEMS software installed on a petrochemical plant.展开更多
In order to monitor the deformations of modern constructions a local 3D network was usually being established at the surrounding area. The centering error, of both the instrument and targets, causes significant uncert...In order to monitor the deformations of modern constructions a local 3D network was usually being established at the surrounding area. The centering error, of both the instrument and targets, causes significant uncertainties in the determination of the x, y, z coordinates of the network's points. In order to assure precise centering for both the instrument and targets, not only for the accessible but also for the inaccessible network's points, a prototype way of marking is being implied. A special semi-permanent portable metallic stand (Photo 1) was manufactured for marking the accessible points. The stand provides forced instrument centering of the order of_+0, lmm. It is light enough to carry, it accelerates and facilitates the centering and leveling of the instrument as well as it eliminates the time needed for the measurements. The applied laboratory checks in order to certify the suitability of its use and the provided accuracy are being described. For the inaccessible points special targets were used. The targets were put in permanent attachments (Photos 7-8), which were also manufactured. Useful conclusions were drawn when these special accessories were used in to a 3D network, which was established for the monitoring of a new football stadium. Two measurement phases were carried out. The first one is with the stadium empty and the second one is when it was crowded (about 32000 people) during a significant football match.展开更多
Global efforts for environmental cleanliness through the control of gaseous emissions from vehicles are gaining momentum and attracting increasing attention. Calibration plays a crucial role in these efforts by ensuri...Global efforts for environmental cleanliness through the control of gaseous emissions from vehicles are gaining momentum and attracting increasing attention. Calibration plays a crucial role in these efforts by ensuring the quantitative assessment of emissions for informed decisions on environmental treatments. This paper describes a method for the calibration of CO/CO<sub>2</sub> monitors used for periodic inspections of vehicles in cites. The calibration was performed in the selected ranges: 900 - 12,000 µmol/mol for CO and 2000 - 20,000 µmol/mol for CO<sub>2</sub>. The traceability of the measurement results to the SI units was ensured by using certified reference materials from CO/N<sub>2</sub> and CO<sub>2</sub>/N<sub>2</sub> primary gas mixtures. The method performance was evaluated by assessing its linearity, accuracy, precision, bias, and uncertainty of the calibration results. The calibration data exhibited a strong linear trend with R² values close to 1, indicating an excellent fit between the measured values and the calibration lines. Precision, expressed as relative standard deviation (%RSD), ranged from 0.48 to 4.56% for CO and from 0.97 to 3.53% for CO<sub>2</sub>, staying well below the 5% threshold for reporting results at a 95% confidence level. Accuracy measured as percent recovery, was consistently high (≥ 99.1%) for CO and ranged from 84.90% to 101.54% across the calibration range for CO<sub>2</sub>. In addition, the method exhibited minimal bias for both CO and CO<sub>2</sub> calibrations and thus provided a reliable and accurate approach for calibrating CO/CO<sub>2</sub> monitors used in vehicle inspections. Thus, it ensures the effectiveness of exhaust emission control for better environment.展开更多
Rock bursts have become one of the most severe risks in underground coal mining and its early warning is an important component in the safety management. Microseismic(MS) monitoring is considered potentially as a powe...Rock bursts have become one of the most severe risks in underground coal mining and its early warning is an important component in the safety management. Microseismic(MS) monitoring is considered potentially as a powerful tool for the early warning of rock burst. In this study, an MS multi-parameter index system was established and the critical values of each index were estimated based on the normalized multi-information warning model of coal-rock dynamic failure. This index system includes bursting strain energy(BSE) index, time-space-magnitude independent information(TSMII) indices and timespace-magnitude compound information(TSMCI) indices. On the basis of this multi-parameter index system, a comprehensive analysis was conducted via introducing the R-value scoring method to calculate the weights of each index. To calibrate the multi-parameter index system and the associated comprehensive analysis, the weights of each index were first confirmed using historical MS data occurred in LW402102 of Hujiahe Coal Mine(China) over a period of four months. This calibrated comprehensive analysis of MS multi-parameter index system was then applied to pre-warn the occurrence of a subsequent rock burst incident in LW 402103. The results demonstrate that this multi-parameter index system combined with the comprehensive analysis are capable of quantitatively pre-warning rock burst risk.展开更多
The Real-Time Global Navigation Satellite System(GNSS)Precise Positioning Service(RTPPS)is recognized as the most promising system by providing precise satellite orbit and clock correc-tions for users to achieve centi...The Real-Time Global Navigation Satellite System(GNSS)Precise Positioning Service(RTPPS)is recognized as the most promising system by providing precise satellite orbit and clock correc-tions for users to achieve centimeter-level positioning with a stand-alone receiver in real-time.Although the products are available with high accuracy almost all the time,they may occasionally suffer from unexpected significant biases,which consequently degrades the positioning perfor-mance.Therefore,quality monitoring at the system-level has become more and more crucial for providing a reliable GNSS service.In this paper,we propose a method for the monitoring of realtime satellite orbit and clock products using a monitoring station network based on the Quality Control(QC)theory.The satellites with possible biases are first detected based on the outliers identified by Precise Point Positioning(PPP)in the monitoring station network.Then,the corresponding orbit and clock parameters with temporal constraints are introduced and esti-mated through the sequential Least Square(LS)estimator and the corresponding Instantaneous User Range Errors(IUREs)can be determined.A quality indicator is calculated based on the IUREs in the monitoring network and compared with a pre-defined threshold.The quality monitoring method is experimentally evaluated by monitoring the real-time orbit and clock products generated by GeoForschungsZentrum(GFZ),Potsdam.The results confirm that the problematic satellites can be detected accurately and effectively with missed detection rate 4×10^(-6) and false alarm rate 1:2×10^(-5).Considering the quality alarms,the PPP results in terms of RMS of positioning differences with respect to the International GNSS Service(IGS)weekly solution in the north,east and up directions can be improved by 12%,10%and 27%,respectively.展开更多
The wide area precise positioning system(WAPPS)is a high-precision positioning system based on a global navigation satellite system.Using a GEO satellite or a communication network,it provides users,in its service are...The wide area precise positioning system(WAPPS)is a high-precision positioning system based on a global navigation satellite system.Using a GEO satellite or a communication network,it provides users,in its service area,with real-time satellite orbit,clock,and other corrections.Users can achieve centimeter-level static positioning or decimeter-level kinematic positioning by precise point positioning.With the demands for applications of both high-precision and safety of life in real time,WAPPS is facing urgent needs to improve its service integrity.This study presents a real-time integrity monitoring approach for WAPPS.Using dual-frequency ionosphere-free corrections of GPS and BDS,along with monitor station data,related error models are established and the integrity monitoring is achieved,based on the analysis of satellite corrected residuals.In addition,satellite faults are simulated for performance verification.The results show that the algorithm can monitor both step and drift faults effectively and alert users in time.展开更多
基金sponsored by the National Research Foundation of Korea(NRF)Grant funded by the Korean government(MSIT)(Grant No.:2018R1A5A2021242).
文摘The spread of tuberculosis(TB),especially multidrug-resistant TB and extensively drug-resistant TB,has strongly motivated the research and development of new anti-TB drugs.New strategies to facilitate drug combinations,including pharmacokinetics-guided dose optimization and toxicology studies of first-and second-line anti-TB drugs have also been introduced and recommended.Liquid chromatography-mass spectrometry(LC-MS)has arguably become the gold standard in the analysis of both endo-and exo-genous compounds.This technique has been applied successfully not only for therapeutic drug monitoring(TDM)but also for pharmacometabolomics analysis.TDM improves the effectiveness of treatment,reduces adverse drug reactions,and the likelihood of drug resistance development in TB patients by determining dosage regimens that produce concentrations within the therapeutic target window.Based on TDM,the dose would be optimized individually to achieve favorable outcomes.Pharmacometabolomics is essential in generating and validating hypotheses regarding the metabolism of anti-TB drugs,aiding in the discovery of potential biomarkers for TB diagnostics,treatment monitoring,and outcome evaluation.This article highlighted the current progresses in TDM of anti-TB drugs based on LC-MS bioassay in the last two decades.Besides,we discussed the advantages and disadvantages of this technique in practical use.The pressing need for non-invasive sampling approaches and stability studies of anti-TB drugs was highlighted.Lastly,we provided perspectives on the prospects of combining LC-MS-based TDM and pharmacometabolomics with other advanced strategies(pharmacometrics,drug and vaccine developments,machine learning/artificial intelligence,among others)to encapsulate in an all-inclusive approach to improve treatment outcomes of TB patients.
基金Projects(40904004,41074010)supported by the National Natural Science Foundation of ChinaProject(BK2009099)supported by the Natural Science Fund of Jiangsu Province,China+2 种基金Project supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,ChinaProjects(200802901516,200802900501)supported by the Ph.D.Programs Foundation of Ministry of Education of ChinaProject supported by the Qing Lan Project of Jiangsu Province,China
文摘Precise point positioning (PPP)-based deformation monitoring scheme is presented for the use in mining deformation monitoring. Within the solutions of daily observation, outliers are detected and removed to avoid any potential misinterpretation of the results and then the deformation can be extracted by the coordinate differences between the two consecutive solutions. Meanwhile, because of the special location of a rover station in mining areas, the satellite geometry may be insufficient for a reasonable PPP solution, and the multipath impact an also be significant. Therefore, it is necessary to predict the satellite geometry before any daily observation. To evaluate the ability of extracting the deformation using the PPP-based method, various quality measures were introduced. The results of three datasets of the same station show that the precision of deformation monitored by PPP can reach up to cm level and even mm level.
文摘To improve the reliability of the light emitting diode(LED)signal lamp filament current monitoring alarm instrument for metro systems,a new type of hot standby online monitoring apparatus was developed which is based on synchronous transmission data(STD)bus technology.In this system,a double hot standby mode can be achieved by adopting bus arbitration.In addition,to detect the effective value of alternating current which is from 0 to 200 mA in the signal lamp lighting circuit,a precision rectifier signal conditioning circuit and an isolated acquisition circuit were designed.This new type of alarm instrument has high detection accuracy and could meet the functional requirements for metro signal systems after comparing it with some industry products that were applied on the spot.
文摘Solar resource monitoring and evaluation is the foundation of informatization of photovoltaic power station. In 2016, China began to bring in high-precision solar resource monitoring technology which provides reliable basic data for the photovoltaic informatization development. This paper systematically sorts out design basis, monitoring elements and system architecture of high-precision monitoring station, and analyzes operation effect of high-precision solar resource monitoring station from performance of solar radiation meter and prediction results of luminous power, which provide important data support for analysis of power generation efficiency of photovoltaic module, prediction of power generation of power station, evaluation of operation effect of power station, etc.
文摘Monitoring the performance of any structure requires real-time measurements of the change of position of critical points. Different techniques can be used for this purpose, each one offering advantages and disadvantages. The technique based on satellite positioning systems (GPS, GLONASS and the future GALILEO) seems to be very promising at least for long period structures. The GPS in particular provides sampling rates that are able to track dynamic displacements with high accuracy. Its service ability is independent of atmospheric conditions, temperature variations and visibility of the monitored object. This paper investigates the reliability and accuracy of the measurements of dual frequency GPS receivers. A linear electromagnetic motor moves an object along a given direction. The changes of position are compared witb their estimates as recorded by a GPS receiver, whose antenna is located on the reference object. The comparison is based on sufficiently long records.
基金partly supported and funded by the Hasler Foundation under the Project“ARPI:Automated Recognition of Pest Insect Images”(20028)。
文摘Pest insect monitoring and control is crucial to ensure a safe and profitable crop growth in all plantation types,as well as guarantee food quality and limited use of pesticides.We aim at extending traditional monitoring by means of traps,by involving the general public in reporting the presence of insects by using smartphones.This includes the largely unexplored problem of detecting insects in images that are taken in noncontrolled conditions.Furthermore,pest insects are,in many cases,extremely similar to other species that are harmless.Therefore,computer vision algorithms must not be fooled by these similar insects,not to raise unmotivated alarms.In this work,we study the capabilities of state-of-the-art(SoA)object detection models based on convolutional neural networks(CNN)for the task of detecting beetle-like pest insects on nonhomogeneous images taken outdoors by different sources.Moreover,we focus on disambiguating a pest insect from similar harmless species.We consider not only detection performance of different models,but also required computational resources.This study aims at providing a baseline model for this kind of tasks.Our results show the suitability of current SoA models for this application,highlighting how FasterRCNN with a MobileNetV3 backbone is a particularly good starting point for accuracy and inference execution latency.This combination provided a mean average precision score of 92.66%that can be considered qualitatively at least as good as the score obtained by other authors that adopted more specific models.
基金Financial support from the National Natural Science Foundation of China (No. 41074010)the Jiangsu Innovation Works Fund of Postgraduate (No. CXZZ11-0299)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘The mining area deformation monitoring theory and method using precise point positioning (PPP) ambi- guity resolution (AR) were studied, and an ambiguity fixing model with satellite and receiver combina- tion phase delay (CPD) was proposed for zero-differenced PPP ambiguity fixing and its corresponding formula derivation was given. The data processing results for I h at six IGS stations in China show that 93% of ambiguities can be fixed within 10 min and all ambiguities can be fixed within 15 min. After ambi- guity fixing, the positioning accuracy is improved by more than 85% in the E and N directions, with abso- lute positioning accuracy reaching millimeter level, and it was improved by 70% in the U direction, reaching centimeter level; the proposed zero-differenced ambiguity fixing model can effectively improve the convergence rate and positioning accuracy in PPP. Data monitoring continuously conducted for half a year at four COPS stations of Shanxi China Coal Pingshuo Group validated the feasibility of using PPP in mining area deformation monitoring.
基金Sponsored by the Ordnance Industry Scientific Research Fund(ZZ9682-3).
文摘The accurate monitoring of optical thin-film thickness is a key technique for depositing optical thin-film. For existing coating equipments, which are low precision and automation level on monitoring thin-film thickness, a new photoelectric control and analysis system has been developed. In the new system, main techniques include a photoelectric system with dual-light path, a dual-lock-phase circuit system and a comprehensive digital processing-control-analysis system.The test results of new system show that the static and dynamic stabilities and the control precision of thin-film thickness are extremely increased. The standard deviation of thin-film thickness, which indicates the duplication of thin-film thickness monitoring, is equal to or less than 0.72%. The display resolution limit on reflectivity is 0.02 %. In the system, the linearity of drift is very high, and the static drift ratio approaches zero.
文摘Predictive Emission Monitoring Systems (PEMS) offer a cost-effective and environmentally friendly alternative to Continuous Emission Monitoring Systems (CEMS) for monitoring pollution from industrial sources. Multiple regression is one of the fundamental statistical techniques to describe the relationship between dependent and independent variables. This model can be effectively used to develop a PEMS, to estimate the amount of pollution emitted by industrial sources, where the fuel composition and other process-related parameters are available. It often makes them sufficient to predict the emission discharge with acceptable accuracy. In cases where PEMS are accepted as an alternative method to CEMS, which use gas analyzers, they can provide cost savings and substantial benefits for ongoing system support and maintenance. The described mathematical concept is based on the matrix algebra representation in multiple regression involving multiple precision arithmetic techniques. Challenging numerical examples for statistical big data analysis, are investigated. Numerical examples illustrate computational accuracy and efficiency of statistical analysis due to increasing the precision level. The programming language C++ is used for mathematical model implementation. The data for research and development, including the dependent fuel and independent NOx emissions data, were obtained from CEMS software installed on a petrochemical plant.
文摘In order to monitor the deformations of modern constructions a local 3D network was usually being established at the surrounding area. The centering error, of both the instrument and targets, causes significant uncertainties in the determination of the x, y, z coordinates of the network's points. In order to assure precise centering for both the instrument and targets, not only for the accessible but also for the inaccessible network's points, a prototype way of marking is being implied. A special semi-permanent portable metallic stand (Photo 1) was manufactured for marking the accessible points. The stand provides forced instrument centering of the order of_+0, lmm. It is light enough to carry, it accelerates and facilitates the centering and leveling of the instrument as well as it eliminates the time needed for the measurements. The applied laboratory checks in order to certify the suitability of its use and the provided accuracy are being described. For the inaccessible points special targets were used. The targets were put in permanent attachments (Photos 7-8), which were also manufactured. Useful conclusions were drawn when these special accessories were used in to a 3D network, which was established for the monitoring of a new football stadium. Two measurement phases were carried out. The first one is with the stadium empty and the second one is when it was crowded (about 32000 people) during a significant football match.
文摘Global efforts for environmental cleanliness through the control of gaseous emissions from vehicles are gaining momentum and attracting increasing attention. Calibration plays a crucial role in these efforts by ensuring the quantitative assessment of emissions for informed decisions on environmental treatments. This paper describes a method for the calibration of CO/CO<sub>2</sub> monitors used for periodic inspections of vehicles in cites. The calibration was performed in the selected ranges: 900 - 12,000 µmol/mol for CO and 2000 - 20,000 µmol/mol for CO<sub>2</sub>. The traceability of the measurement results to the SI units was ensured by using certified reference materials from CO/N<sub>2</sub> and CO<sub>2</sub>/N<sub>2</sub> primary gas mixtures. The method performance was evaluated by assessing its linearity, accuracy, precision, bias, and uncertainty of the calibration results. The calibration data exhibited a strong linear trend with R² values close to 1, indicating an excellent fit between the measured values and the calibration lines. Precision, expressed as relative standard deviation (%RSD), ranged from 0.48 to 4.56% for CO and from 0.97 to 3.53% for CO<sub>2</sub>, staying well below the 5% threshold for reporting results at a 95% confidence level. Accuracy measured as percent recovery, was consistently high (≥ 99.1%) for CO and ranged from 84.90% to 101.54% across the calibration range for CO<sub>2</sub>. In addition, the method exhibited minimal bias for both CO and CO<sub>2</sub> calibrations and thus provided a reliable and accurate approach for calibrating CO/CO<sub>2</sub> monitors used in vehicle inspections. Thus, it ensures the effectiveness of exhaust emission control for better environment.
基金provided by the State Key Research Development Program of China (No.2016YFC0801403)Key Research Development Program of Jiangsu Provence (No.BE2015040)+1 种基金National Natural Science Foundation of China (Nos.51674253,51734009 and 51604270)Natural Science Foundation of Jiangsu Province (No.BK20171191)
文摘Rock bursts have become one of the most severe risks in underground coal mining and its early warning is an important component in the safety management. Microseismic(MS) monitoring is considered potentially as a powerful tool for the early warning of rock burst. In this study, an MS multi-parameter index system was established and the critical values of each index were estimated based on the normalized multi-information warning model of coal-rock dynamic failure. This index system includes bursting strain energy(BSE) index, time-space-magnitude independent information(TSMII) indices and timespace-magnitude compound information(TSMCI) indices. On the basis of this multi-parameter index system, a comprehensive analysis was conducted via introducing the R-value scoring method to calculate the weights of each index. To calibrate the multi-parameter index system and the associated comprehensive analysis, the weights of each index were first confirmed using historical MS data occurred in LW402102 of Hujiahe Coal Mine(China) over a period of four months. This calibrated comprehensive analysis of MS multi-parameter index system was then applied to pre-warn the occurrence of a subsequent rock burst incident in LW 402103. The results demonstrate that this multi-parameter index system combined with the comprehensive analysis are capable of quantitatively pre-warning rock burst risk.
基金funded by the National Natural Science Foundation of China(42030109).
文摘The Real-Time Global Navigation Satellite System(GNSS)Precise Positioning Service(RTPPS)is recognized as the most promising system by providing precise satellite orbit and clock correc-tions for users to achieve centimeter-level positioning with a stand-alone receiver in real-time.Although the products are available with high accuracy almost all the time,they may occasionally suffer from unexpected significant biases,which consequently degrades the positioning perfor-mance.Therefore,quality monitoring at the system-level has become more and more crucial for providing a reliable GNSS service.In this paper,we propose a method for the monitoring of realtime satellite orbit and clock products using a monitoring station network based on the Quality Control(QC)theory.The satellites with possible biases are first detected based on the outliers identified by Precise Point Positioning(PPP)in the monitoring station network.Then,the corresponding orbit and clock parameters with temporal constraints are introduced and esti-mated through the sequential Least Square(LS)estimator and the corresponding Instantaneous User Range Errors(IUREs)can be determined.A quality indicator is calculated based on the IUREs in the monitoring network and compared with a pre-defined threshold.The quality monitoring method is experimentally evaluated by monitoring the real-time orbit and clock products generated by GeoForschungsZentrum(GFZ),Potsdam.The results confirm that the problematic satellites can be detected accurately and effectively with missed detection rate 4×10^(-6) and false alarm rate 1:2×10^(-5).Considering the quality alarms,the PPP results in terms of RMS of positioning differences with respect to the International GNSS Service(IGS)weekly solution in the north,east and up directions can be improved by 12%,10%and 27%,respectively.
文摘The wide area precise positioning system(WAPPS)is a high-precision positioning system based on a global navigation satellite system.Using a GEO satellite or a communication network,it provides users,in its service area,with real-time satellite orbit,clock,and other corrections.Users can achieve centimeter-level static positioning or decimeter-level kinematic positioning by precise point positioning.With the demands for applications of both high-precision and safety of life in real time,WAPPS is facing urgent needs to improve its service integrity.This study presents a real-time integrity monitoring approach for WAPPS.Using dual-frequency ionosphere-free corrections of GPS and BDS,along with monitor station data,related error models are established and the integrity monitoring is achieved,based on the analysis of satellite corrected residuals.In addition,satellite faults are simulated for performance verification.The results show that the algorithm can monitor both step and drift faults effectively and alert users in time.