The purpose of this study is to develop a Web-based on-machine mould identification and measurement system. The Web-based mould identification system matches obtained vision information with CAD database. Developed We...The purpose of this study is to develop a Web-based on-machine mould identification and measurement system. The Web-based mould identification system matches obtained vision information with CAD database. Developed Web-based system is to exchange messages between a server and a client by making of ActiveX control, and the result of mould identification is shown on Web-browser at remote site. For effective feature classification and extraction, the signature method is used to make meaningful information from obtained image data. For on-machine measurement of the matched mould, inspection database is constructed from CAD database using developed inspection planning methods. The results are simulated and analyzed using developed system to verify the effectiveness of the proposed methods.展开更多
Reservoir porosity is a critical parameter for the process of unconventional oil and gas resources assessment. It is difficult to determine the porosity of a gas shale reservoir, and any large deviation will directly ...Reservoir porosity is a critical parameter for the process of unconventional oil and gas resources assessment. It is difficult to determine the porosity of a gas shale reservoir, and any large deviation will directly reduce the credibility of any shale gas resources evaluation. However, there is no quantitative explanation for the accuracy of porosity measurement. In this paper, measurement uncertainty, an internationally recognized index, was used to evaluate the results of porosity measurement of gas shale plugs, and its impact on the credibility of shale gas resources assessment was determined. The following conclusions are drawn:(1) the measurement uncertainty of porosity of a shale plug is 1.76%–3.12% using current measurement methods, the upper end of which is too large to be acceptable. It is suggested that the measurement uncertainty should be factored into the standard helium gas injection porosity determination experiment, and the uncertainty should be less than 2.00% when using a high-precision pressure gauge;(2) in order to reduce the risk for exploration and decision-making, attention should be paid to the large uncertainty(30% at least) of shale gas resource assessment results, sometimes with corrections being made based on the practical considerations;(3) a pressure gauge with an accuracy of 0.25% of the full scal cannot meet the requirements of porosity measurement, and a high-precision plug cutting method or high-precision bulk volume measurement method such as one using 3 D scanning, is recommended to effectively reduce porosity uncertainty;(4) the method and process for evaluating the measurement uncertainty of gas shale porosity could also be referred for assessment of experimental quality by other laboratories.展开更多
Benefiting from the improvements of Internet infrastructure and video coding technology, online video services are becoming a new favorite form of video entertainment.However, most of the existing video quality assess...Benefiting from the improvements of Internet infrastructure and video coding technology, online video services are becoming a new favorite form of video entertainment.However, most of the existing video quality assessment methods are designed for broadcasting/cable televisions and it is still an open issue how to assess and measure the quality of online video services. In this paper, we survey the state-of-the-art video streaming technologies, and present a framework of quality assessment and measurement for Internet video streaming. This paper introduces several metrics for user's quality of experience(QoE).These QoE metrics are classified into two categories: objective metrics and subjective metrics. It is different for service participators to measure objective and subjective metrics.The QoE measurement methodologies consist of client-side, server-side, and in-network measurement.展开更多
A fuzzy integral based way of measurement assessment has been established by using linguistic varia-bles and combining fuzzy integral with hierarchy analysis for measurement of medium and small enterprises'product...A fuzzy integral based way of measurement assessment has been established by using linguistic varia-bles and combining fuzzy integral with hierarchy analysis for measurement of medium and small enterprises'product innovation. The conclusions drawn from analyses made with 20 medium and small enterprises providebases for governments to formulate applicable policies and for medium and small enterprises to enhance theirproduct innovation.展开更多
Rail transit plays a key role in mitigating transportation system carbon emissions.Accurate measurement of urban rail transit carbon emission can help quantify the contribution of urban rail transit towards urban tran...Rail transit plays a key role in mitigating transportation system carbon emissions.Accurate measurement of urban rail transit carbon emission can help quantify the contribution of urban rail transit towards urban transportation carbon emission reduction.Since the whole life cycle of urban rail transit carbon emission measurement involves a wide range of aspects,a systematic framework model is required for analysis.This research reviews the existing studies on carbon emission of urban rail transit.First,the characteristics of urban rail transit carbon emission were determined and the complexity of carbon emission measurement was analyzed.Then,the urban rail transit carbon emission measurement models were compared and analyzed in terms of the selection of research boundaries,the types of greenhouse gas(GHG)emissions calculation,and the accuracy of the measurement.Following that,an intelligent station was introduced to analyze the practical application of digital collaboration technology and energy-saving and carbon-reducing system platforms for rail transit.Finally,the urgent problems and future research directions at this stage were discussed.This research presents the necessity of establishing a dynamic carbon emission factor library and the important development trend of system integration of carbon emission measurement and digital system technology.展开更多
A new constrained eigenvalue method for scattering parameter measurements oftwo-port lossless reciprocal network is developed.The non-linear S-curve problem is easily trans-formed into a simple linear one by this meth...A new constrained eigenvalue method for scattering parameter measurements oftwo-port lossless reciprocal network is developed.The non-linear S-curve problem is easily trans-formed into a simple linear one by this method.All formulas are programmed on the IBM-PCdigital computer.Some examples are given.展开更多
[目的]对乳腺癌认知问卷(Breast Module of the Cancer Awareness Measure,Breast-CAM)进行汉化,并对中文版问卷的效度和信度进行初步评价。[方法]经过翻译、回译和文化调试,确定中文版Breast-CAM问卷的条目。应用中文版Breast-CAM问卷...[目的]对乳腺癌认知问卷(Breast Module of the Cancer Awareness Measure,Breast-CAM)进行汉化,并对中文版问卷的效度和信度进行初步评价。[方法]经过翻译、回译和文化调试,确定中文版Breast-CAM问卷的条目。应用中文版Breast-CAM问卷对216名住院病人的女性照顾者进行调查,通过探索性因子分析提取因子,通过计算Cronbach'sα系数和重测相关系数,检验问卷的内在一致性信度和重测信度。[结果]中文版Breast-CAM问卷的Cronbach'sα系数为0.912,问卷的折半系数为0.836,重测信度为0.721;问卷共提取疾病症状的相关知识,与乳腺改变相关的信心、技能和行为,寻求医疗帮助的障碍,乳房筛查知识和危险因素5个公因子,36个条目。[结论]修订后的中文版Breast-CAM问卷具有良好的信效度,可作为评估和测量女性人群对乳腺癌认知的测评工具。展开更多
Background Task-based measurement （TBM） is a method to assess the eight-hour A-weighted equivalent noise exposure level （LAeq. 8h） besides dosimeter. TBM can be better used in factories by non-professional workers...Background Task-based measurement （TBM） is a method to assess the eight-hour A-weighted equivalent noise exposure level （LAeq. 8h） besides dosimeter. TBM can be better used in factories by non-professional workers and staffs.However, it is still not clear if TBM is equal or similar with dosimeter for LAeq.8h measurement in general. This study considered the measurement with dosimeter as real personal noise exposure level （PNEL） and assessed the accuracy of TBM by comparing the consistencies of TBM and dosimeter in LAeq.8h measurement.Methods The study was conducted in one automobile firm among 387 workers who are exposed to unstable noise.Dosimeters and TBM were used to compare the two strategies and assess the degree of agreement and causes of disagreement. Worker＇s PNEL was measured via TBM for noise; the real PNEL was also recorded. The TBM for noise was computed with task/position noise levels measured via sound level meter and workers＇ exposure information collected via working diary forms （WDF） filled by participants themselves. Full-shift noise exposure measurement via personal noise dosimeters were taken as the real PNEL. General linear model （GLM） was built to analyze the accuracy of TBM for noise and the source of difference between TBM for noise and real PNEL.Results The LAeq.8h with TBM were slightly higher than the real PNELs, except the electricians. Differences of the two values had statistical significance in stamping workers （P ＜0.001）, assembly workers （P=0.015） and welding workers （P=0.001）. The correlation coefficient of LAeq.8h with TBM and real PNELs was 0.841. Differences of the two results were mainly affected by real PNEL （F=11.27, P=0.001）; and work groups （F=3.11, P ＜0.001） divided by jobs and workshops were also independent factors. PNEL of workers with fixed task/position （（86.53±8.82） dB（A）） was higher than those without （（75.76±9.92） dB（A）） （t=8.84, P ＜0.01）. Whether workers had fixed task/position was another factor on the accuracy of TBM for noise （F=4.36,P=0.038）.Conclusion TBM for noise has acceptable accuracy on workers＇ PNEL measurement. The accuracy is affected by job categories, workshops and variability of task/position. TBM for noise can yield a relatively conservative result of worker＇s PNEL in most cases, so it can be used to measure and assess workers＇ real PNEL.展开更多
A comparison study on the ultrasonic blood flow estimation methods is carried out in this paper. The methods are divided into two classes-narrowband and wideband techniques.The pulsed Doppler systems and the autocorre...A comparison study on the ultrasonic blood flow estimation methods is carried out in this paper. The methods are divided into two classes-narrowband and wideband techniques.The pulsed Doppler systems and the autocorrelation methods are essentially the narrowband estAnators. They give the results with low velocity resolution and probably the aliased spectrum.The wider the frequency band of the signals, the worse the results. Time domain crosscorrelation technique, wideband makimum likelihood estimation and 2D Fourier transform method are three wideband techniques. The high velocity resolution and the ability of anti-aliasing are shown by these wideband estimation strategies.展开更多
基金Project (No. KRF-2005-202-D00046) supported by the Korea Re-search Foundation
文摘The purpose of this study is to develop a Web-based on-machine mould identification and measurement system. The Web-based mould identification system matches obtained vision information with CAD database. Developed Web-based system is to exchange messages between a server and a client by making of ActiveX control, and the result of mould identification is shown on Web-browser at remote site. For effective feature classification and extraction, the signature method is used to make meaningful information from obtained image data. For on-machine measurement of the matched mould, inspection database is constructed from CAD database using developed inspection planning methods. The results are simulated and analyzed using developed system to verify the effectiveness of the proposed methods.
基金the National Key R&D Program of China(Grant No.2017YFC0603101)the National Science and Technology Major Project of China(Grant No.2016ZX05003-002)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA1401010I,XDA14010403)the Science and Technology Programe of RIPED.PetroChina(Grant No.YGJ2019-05).
文摘Reservoir porosity is a critical parameter for the process of unconventional oil and gas resources assessment. It is difficult to determine the porosity of a gas shale reservoir, and any large deviation will directly reduce the credibility of any shale gas resources evaluation. However, there is no quantitative explanation for the accuracy of porosity measurement. In this paper, measurement uncertainty, an internationally recognized index, was used to evaluate the results of porosity measurement of gas shale plugs, and its impact on the credibility of shale gas resources assessment was determined. The following conclusions are drawn:(1) the measurement uncertainty of porosity of a shale plug is 1.76%–3.12% using current measurement methods, the upper end of which is too large to be acceptable. It is suggested that the measurement uncertainty should be factored into the standard helium gas injection porosity determination experiment, and the uncertainty should be less than 2.00% when using a high-precision pressure gauge;(2) in order to reduce the risk for exploration and decision-making, attention should be paid to the large uncertainty(30% at least) of shale gas resource assessment results, sometimes with corrections being made based on the practical considerations;(3) a pressure gauge with an accuracy of 0.25% of the full scal cannot meet the requirements of porosity measurement, and a high-precision plug cutting method or high-precision bulk volume measurement method such as one using 3 D scanning, is recommended to effectively reduce porosity uncertainty;(4) the method and process for evaluating the measurement uncertainty of gas shale porosity could also be referred for assessment of experimental quality by other laboratories.
基金supported by National Key R&D Program of China No.2018YFB0803702Beijing Culture Development Funding under Grant No.2016-288Toutiao Funding No.ZN20171224003
文摘Benefiting from the improvements of Internet infrastructure and video coding technology, online video services are becoming a new favorite form of video entertainment.However, most of the existing video quality assessment methods are designed for broadcasting/cable televisions and it is still an open issue how to assess and measure the quality of online video services. In this paper, we survey the state-of-the-art video streaming technologies, and present a framework of quality assessment and measurement for Internet video streaming. This paper introduces several metrics for user's quality of experience(QoE).These QoE metrics are classified into two categories: objective metrics and subjective metrics. It is different for service participators to measure objective and subjective metrics.The QoE measurement methodologies consist of client-side, server-side, and in-network measurement.
基金Sponsored by the National Natural Science Foundation of China (Grant No. 70171039)Major Project of the National Natural Science Foundation of China (Grant No. 70131010 )Natural Science Foundation of Heilongjiang Province (Grant No. G01-09)
文摘A fuzzy integral based way of measurement assessment has been established by using linguistic varia-bles and combining fuzzy integral with hierarchy analysis for measurement of medium and small enterprises'product innovation. The conclusions drawn from analyses made with 20 medium and small enterprises providebases for governments to formulate applicable policies and for medium and small enterprises to enhance theirproduct innovation.
基金supported by Beijing Natural Science Foundation(J210001)Natural Science Foundation of Hebei Province(E2021210142)Tianjin Natural Science Foundation(21JCZXJC00160).
文摘Rail transit plays a key role in mitigating transportation system carbon emissions.Accurate measurement of urban rail transit carbon emission can help quantify the contribution of urban rail transit towards urban transportation carbon emission reduction.Since the whole life cycle of urban rail transit carbon emission measurement involves a wide range of aspects,a systematic framework model is required for analysis.This research reviews the existing studies on carbon emission of urban rail transit.First,the characteristics of urban rail transit carbon emission were determined and the complexity of carbon emission measurement was analyzed.Then,the urban rail transit carbon emission measurement models were compared and analyzed in terms of the selection of research boundaries,the types of greenhouse gas(GHG)emissions calculation,and the accuracy of the measurement.Following that,an intelligent station was introduced to analyze the practical application of digital collaboration technology and energy-saving and carbon-reducing system platforms for rail transit.Finally,the urgent problems and future research directions at this stage were discussed.This research presents the necessity of establishing a dynamic carbon emission factor library and the important development trend of system integration of carbon emission measurement and digital system technology.
文摘A new constrained eigenvalue method for scattering parameter measurements oftwo-port lossless reciprocal network is developed.The non-linear S-curve problem is easily trans-formed into a simple linear one by this method.All formulas are programmed on the IBM-PCdigital computer.Some examples are given.
文摘[目的]对乳腺癌认知问卷(Breast Module of the Cancer Awareness Measure,Breast-CAM)进行汉化,并对中文版问卷的效度和信度进行初步评价。[方法]经过翻译、回译和文化调试,确定中文版Breast-CAM问卷的条目。应用中文版Breast-CAM问卷对216名住院病人的女性照顾者进行调查,通过探索性因子分析提取因子,通过计算Cronbach'sα系数和重测相关系数,检验问卷的内在一致性信度和重测信度。[结果]中文版Breast-CAM问卷的Cronbach'sα系数为0.912,问卷的折半系数为0.836,重测信度为0.721;问卷共提取疾病症状的相关知识,与乳腺改变相关的信心、技能和行为,寻求医疗帮助的障碍,乳房筛查知识和危险因素5个公因子,36个条目。[结论]修订后的中文版Breast-CAM问卷具有良好的信效度,可作为评估和测量女性人群对乳腺癌认知的测评工具。
基金The study was supported by the grants from the National Natural Science Foundation of China （No. 30640085） and the National Institution of Health （USA） （No. 1 R010H008967-01A2）.
文摘Background Task-based measurement （TBM） is a method to assess the eight-hour A-weighted equivalent noise exposure level （LAeq. 8h） besides dosimeter. TBM can be better used in factories by non-professional workers and staffs.However, it is still not clear if TBM is equal or similar with dosimeter for LAeq.8h measurement in general. This study considered the measurement with dosimeter as real personal noise exposure level （PNEL） and assessed the accuracy of TBM by comparing the consistencies of TBM and dosimeter in LAeq.8h measurement.Methods The study was conducted in one automobile firm among 387 workers who are exposed to unstable noise.Dosimeters and TBM were used to compare the two strategies and assess the degree of agreement and causes of disagreement. Worker＇s PNEL was measured via TBM for noise; the real PNEL was also recorded. The TBM for noise was computed with task/position noise levels measured via sound level meter and workers＇ exposure information collected via working diary forms （WDF） filled by participants themselves. Full-shift noise exposure measurement via personal noise dosimeters were taken as the real PNEL. General linear model （GLM） was built to analyze the accuracy of TBM for noise and the source of difference between TBM for noise and real PNEL.Results The LAeq.8h with TBM were slightly higher than the real PNELs, except the electricians. Differences of the two values had statistical significance in stamping workers （P ＜0.001）, assembly workers （P=0.015） and welding workers （P=0.001）. The correlation coefficient of LAeq.8h with TBM and real PNELs was 0.841. Differences of the two results were mainly affected by real PNEL （F=11.27, P=0.001）; and work groups （F=3.11, P ＜0.001） divided by jobs and workshops were also independent factors. PNEL of workers with fixed task/position （（86.53±8.82） dB（A）） was higher than those without （（75.76±9.92） dB（A）） （t=8.84, P ＜0.01）. Whether workers had fixed task/position was another factor on the accuracy of TBM for noise （F=4.36,P=0.038）.Conclusion TBM for noise has acceptable accuracy on workers＇ PNEL measurement. The accuracy is affected by job categories, workshops and variability of task/position. TBM for noise can yield a relatively conservative result of worker＇s PNEL in most cases, so it can be used to measure and assess workers＇ real PNEL.
文摘A comparison study on the ultrasonic blood flow estimation methods is carried out in this paper. The methods are divided into two classes-narrowband and wideband techniques.The pulsed Doppler systems and the autocorrelation methods are essentially the narrowband estAnators. They give the results with low velocity resolution and probably the aliased spectrum.The wider the frequency band of the signals, the worse the results. Time domain crosscorrelation technique, wideband makimum likelihood estimation and 2D Fourier transform method are three wideband techniques. The high velocity resolution and the ability of anti-aliasing are shown by these wideband estimation strategies.
