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A Nationwide Evaluation of the State of Practice of Performance Measurements for Intelligent Transportation Systems
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作者 Kwabena A. Abedi Julius Codjoe Raju Thapa 《Journal of Transportation Technologies》 2023年第2期222-242,共21页
State departments of transportation’s (DOTs) decisions to invest resources to expand or implement intelligent transportation systems (ITS) programs or even retire existing infrastructure need to be based on performan... State departments of transportation’s (DOTs) decisions to invest resources to expand or implement intelligent transportation systems (ITS) programs or even retire existing infrastructure need to be based on performance evaluations. Nonetheless, an apparent gap exists between the need for ITS performance measurements and the actual implementation. The evidence available points to challenges in the ITS performance measurement processes. This paper evaluated the state of practice of performance measurement for ITS across the US and provided insights. A comprehensive literature review assessed the use of performance measures by DOTs for monitoring implemented ITS programs. Based on the gaps identified through the literature review, a nationwide qualitative survey was used to gather insights from key stakeholders on the subject matter and presented in this paper. From the data gathered, performance measurement of ITS is fairly integrated into ITS programs by DOTs, with most agencies considering the process beneficial. There, however, exist reasons that prevent agencies from measuring ITS performance to greater detail and quality. These include lack of data, fragmented or incomparable data formats, the complexity of the endeavor, lack of data scientists, and difficulty assigning responsibilities when inter-agency collaboration is required. Additionally, DOTs do not benchmark or compare their ITS performance with others for reasons that include lack of data, lack of guidance or best practices, and incomparable data formats. This paper is relevant as it provides insights expected to guide DOTs and other agencies in developing or reevaluating their ITS performance measurement processes. 展开更多
关键词 Intelligent Transportation Systems ITS Performance measures ITS Architecture ARC-IT Qualitative Survey evaluation NATIONWIDE
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Socio-scientific quantification of the comprehensive benefits of debris flow mitigation measures for villages in western Sichuan, China
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作者 DENG Ting XU Pei +4 位作者 LI Ming LU Yafeng WANG Yukuan LI Zhengyang SHRAVAN Kumar Ghimire 《Journal of Mountain Science》 SCIE CSCD 2024年第5期1598-1612,共15页
Debris flow hazards seriously threaten thesafety and sustainable development of mountainousareas. Numerous debris flow mitigation measures havebeen implemented worldwide;however, acomprehensive assessment of the speci... Debris flow hazards seriously threaten thesafety and sustainable development of mountainousareas. Numerous debris flow mitigation measures havebeen implemented worldwide;however, acomprehensive assessment of the specific disasterreduction effects of these measures and their economic,social and ecological benefits is yet to be performed.The western region of Sichuan Province frequentlysuffers from geohazards such as debris flow, and thegovernment has adopted many mitigation measures.This study assessed the benefits of debris flowmitigation measures and identified the key influencingfactors via a field-based study conducted in 81 villagesin western Sichuan province, China. A framework forthe evaluation of the benefits of rural debris flowmitigation measures was constructed andquantitatively evaluated using a survey. Snowballsampling was performed to recruit 81 village leadersand 468 farmers. The results showed that managementand engineering measures were the main methodsused to mitigate debris flow;ecological measures wereauxiliary. The average satisfaction scores of farmers forthese three types of measures were 4.07, 3.90, and 3.56,respectively (as measured on a five-point Likert scale).In contrast, in terms of the benefits of these mitigationmeasures, only a small proportion of villages (11.11%)obtained a high level of comprehensive benefits fromthe debris flow mitigation measures, while the majority(88.89%) received medium to low-level benefits. Toimprove this situation, we further studied and foundthat the main factors that restricted villages fromachieving high-level comprehensive benefits were theunpredictable nature of debris flows, labour forceoutflow and remoteness. Effective control measures, agood economic environment and strong governmentassistance were reported as crucial factors forimproving these comprehensive benefits. This studyprovides socio-scientific references for decisionmakingon rural debris flow mitigation measures while keeping villages at the centre of economic development. 展开更多
关键词 Mitigation measures Comprehensive benefit evaluation Debris flow Mountain development Rural areas
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Efficacy evaluation and survival analysis of the combination of oxaliplatin plus Teysuno (SOX) with immune checkpoint inhibitors in the conversion therapy of locally advanced gastric cancer
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作者 Shuai Liu Kai Zhang +1 位作者 Xiaoqing Zhang Wei Luan 《Oncology and Translational Medicine》 CAS 2024年第4期190-197,共8页
Background:The efficacy of combining immune checkpoint inhibitors(ICIs)with chemotherapy in neoadjuvant therapy for locally advanced gastric cancer has been explored.However,limited research exists on its effectivenes... Background:The efficacy of combining immune checkpoint inhibitors(ICIs)with chemotherapy in neoadjuvant therapy for locally advanced gastric cancer has been explored.However,limited research exists on its effectiveness in conversion therapy,and its superiority over standalone chemotherapy remains to be elucidated.This study aims to investigate the efficacy and survival outcomes of patients treated with ICIs in combination with conversion therapy for locally advanced gastric cancer.Methods:Retrospective data from patients with locally advanced gastric cancer treated with either oxaliplatin+S-1(SOX)alone or in combination with ICIs in conversion therapywere collected.Clinical andpathological characteristics,disease-free survival,andefficacy assessments in nonoperable patients were compared between the 2 treatment groups.Efficacy was further evaluated through dynamic changes in serum markers,and patients’quality of life was assessed using the QLQ-STO22(Gastric Cancer–Specific Quality of Life Questionnaire)quality-of-life measurement scale.Results:A total of 140 patients underwent conversion therapy:80 in the SOX alone group and 60 in the SOX combined with the ICIs group.There were no significant differences in baseline characteristics between the 2 groups.Compared with the SOX alone group,the SOX combined with ICIs group exhibited a higher conversion rate(83.3%vs 75%,P=0.23),R0 resection rate(90.0%vs 83.3%,P=0.31),pathological complete response(pCR)rate(18%vs 5%,P=0.02),median disease-free survival(21.4 vs 16.9 months,P=0.007),the objective response rate in nonoperable patients(60%vs 40%,P=0.301),and median progression-free survival time(7.9 vs 5.7 months,P=0.009).The QLQ-STO22 quality-of-life assessment revealed statistically significant improvements in pain,swallowing difficulties,and dietary restrictions in the combination therapy group compared with those in the monotherapy group.The enhanced efficacy of immune combination with SOX is evident,as demonstrated by the significantly prolonged surgical duration in operated patients(206.6±26.6 min vs 197.8±19.8 min,P=0.35)and intraoperative blood loss(158.9±21.2 mL vs 148.9±25.1 mL,P=0.59).No significant differences were observed in postoperative complications.Conclusions:Compared with the SOX conversion therapy regimen,SOX combined with ICIs demonstrated higher conversion rates,R0 resection rates,pathological response rates,and disease-free survival without increasing surgical difficulty or complications.Nonoperable patients also experienced longer progression-free survival and objective response rates. 展开更多
关键词 Conversion therapy Locally advanced gastric cancer Immune checkpoint inhibitors GASTRECTOMY Efficacy evaluation Survival analysis Quality-of-life measurement
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Comprehensive applicability evaluation of four precipitation products at multiple spatiotemporal scales in Northwest China
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作者 WANG Xiangyu XU Min +3 位作者 KANG Shichang LI Xuemei HAN Haidong LI Xingdong 《Journal of Arid Land》 SCIE CSCD 2024年第9期1232-1254,共23页
Precipitation plays a crucial role in the water cycle of Northwest China.Obtaining accurate precipitation data is crucial for regional water resource management,hydrological forecasting,flood control and drought relie... Precipitation plays a crucial role in the water cycle of Northwest China.Obtaining accurate precipitation data is crucial for regional water resource management,hydrological forecasting,flood control and drought relief.Currently,the applicability of multi-source precipitation products for long time series in Northwest China has not been thoroughly evaluated.In this study,precipitation data from 183 meteorological stations in Northwest China from 1979 to 2020 were selected to assess the regional applicability of four precipitation products(the fifth generation of European Centre for Medium-Range Weather Forecasts(ECMWF)atmospheric reanalysis of the global climate(ERA5),Global Precipitation Climatology Centre(GPCC),Climatic Research Unit gridded Time Series Version 4.07(CRU TS v4.07,hereafter CRU),and Tropical Rainfall Measuring Mission(TRMM))based on the following statistical indicators:correlation coefficient,root mean square error(RMSE),relative bias(RB),mean absolute error(MAE),probability of detection(POD),false alarm ratio(FAR),and equitable threat score(ETS).The results showed that precipitation in Northwest China was generally high in the east and low in the west,and exhibited an increasing trend from 1979 to 2020.Compared with the station observations,ERA5 showed a larger spatial distribution difference than the other products.The overall overestimation of multi-year average precipitation was approximately 200.00 mm and the degree of overestimation increased with increasing precipitation intensity.The multi-year average precipitation of GPCC and CRU was relatively close to that of station observations.The trend of annual precipitation of TRMM was overestimated in high-altitude regions and the eastern part of Lanzhou with more precipitation.At the monthly scale,GPCC performed well but underestimated precipitation in the Tarim Basin(RB=-4.11%),while ERA5 and TRMM exhibited poor accuracy in high-altitude regions.ERA5 had a large bias(RB≥120.00%)in winter months and a strong dispersion(RMSE≥35.00 mm)in summer months.TRMM showed a relatively low correlation with station observations in winter months(correlation coefficients≤0.70).The capture performance analysis showed that ERA5,GPCC,and TRMM had lower POD and ETS values and higher FAR values in Northwest China as the precipitation intensity increased.ERA5 showed a high capture performance for small precipitation events and a slower decreasing trend of POD as the precipitation intensity increased.GPCC had the lowest FAR values.TRMM was statistically ineffective for predicting the occurrence of daily precipitation events.The findings provide a reference for data users to select appropriate datasets in Northwest China and for data developers to develop new precipitation products in the future. 展开更多
关键词 precipitation products the fifth generation of European Centre for Medium-Range Weather Forecasts(ECMWF)atmospheric reanalysis of the global climate(ERA5) Global Precipitation Climatology Centre(GPCC) Climatic Research Unit gridded Time Series(CRU TS) Tropical Rainfall measuring Mission(TRMM) applicability evaluation Northwest China
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First Evaluation and Frequency Measurement of the Strontium Optical Lattice Clock at NIM 被引量:13
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作者 林弋戈 王强 +7 位作者 李烨 孟飞 林百科 臧二军 孙震 房芳 李天初 方占军 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第9期17-20,共4页
An optical lattice clock based on 87Sr is built at National Institute of Metrology (NIM) of China. The systematic frequency shifts of the clock are evaluated with a total uncertainty of 2.3×10-16. To measure it... An optical lattice clock based on 87Sr is built at National Institute of Metrology (NIM) of China. The systematic frequency shifts of the clock are evaluated with a total uncertainty of 2.3×10-16. To measure its absolute frequency with respect to NIM's cesium fountain clock NIM5, the frequency of a flywheel H-maser of NIM5 is transferred to the Sr laboratory through a 50-kin-long fiber. reference frequency of this H-maser, is used for the optical this Sr clock is measured to be 429228004229873.7(1.4)Hz. A fiber optical frequency comb, phase-locked to the frequency measurement. The absolute frequency of 展开更多
关键词 AOM First evaluation and Frequency measurement of the Strontium Optical Lattice Clock at NIM
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Pre-evaluation on stability of proposed expressway embankment with existing geothermal regulation measures in permafrost regions 被引量:2
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作者 LUO Xiao-xiao MA Qin-guo JIANG Hai-qiang 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第1期264-283,共20页
Embankment stability is the primary problem for the expressway construction in permafrost regions.The proposed Qinghai-Tibet Expressway(QTE)is planned to construct along the Qinghai-Tibet Project Corridor.Confronted w... Embankment stability is the primary problem for the expressway construction in permafrost regions.The proposed Qinghai-Tibet Expressway(QTE)is planned to construct along the Qinghai-Tibet Project Corridor.Confronted with harsh environmental condition and intense heat exchange between earth and atmosphere,it is necessary to predict and evaluate the stability of the proposed QTE.In this study,the factors affecting the embankment stability are analyzed firstly.And then,a scheme for the stability evaluation of the embankment is established.Finally,the evaluation scheme is used for the pre-evaluation of the stability for the proposed QTE with different geothermal regulation measures(GRMs).The results indicate that the influencing factors include climatic environment,permafrost property,engineering condition and geological condition,and among them,engineering condition and permafrost property are the main influence factors for embankment stability.The stability of the proposed QTE varies greatly in the different geomorphological regions.The application effect and contribution to embankment stability of the existing GRMs are different,and using GRMs cannot completely overcome the influence of various factors on expressway stability.In the construction process,different GRMs should be adopted depending on the geomorphological environment where the embankment is located to ensure the embankment stability. 展开更多
关键词 PERMAFROST expressway embankment influencing factor stability evaluation geothermal regulation measures
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Fire risk evaluation research on fully mechanized coalface based on the uncertainty measure theory 被引量:1
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作者 JIA Hai-lin YU Ming-gao Chang Xu-hua 《Journal of Coal Science & Engineering(China)》 2010年第2期157-162,共6页
A relatively perfect coalmine fire risk-evaluating and order-arranging model that includes sixteen influential factors was established according to the statistical information of the fully mechanized coalface ground o... A relatively perfect coalmine fire risk-evaluating and order-arranging model that includes sixteen influential factors was established according to the statistical information of the fully mechanized coalface ground on the uncertainty measure theory. Then the single-index measure function of sixteen influential factors and the calculation method of computing the index weight ground on entropy theory were respectively established. The value assignment of sixteen influential factors was carried out by the qualitative analysis and observational data, respectively, in succession. The sequence of fire danger class of four experimental coalfaces could be obtained by the computational aids of Matlab according to the confidence level criterion. Some conclusions that the fire danger class of the No.l, No.2 and No.3 coalface belongs to high criticality can be obtained. But the fire danger class of the No.4 coalface belongs to higher criticality. The fire danger class of the No.4 coalface is more than that of the No.2 coalface. The fire danger class of the No.2 coalface is more than that of the No.1 coalface. Finally, the fire danger class of the No.1 coalface is more than that of the No.3 coalface. 展开更多
关键词 fully mechanized coalface fire risk evaluation uncertainty measure single-index measure function sequence of fire danger class
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Multilevel Tests and Measurement Evaluation Methods for the Application of Composite Materials in Spacecraft Structures 被引量:1
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作者 WANG Yuhang GUO Liangshuai +2 位作者 ZHOU Peng ZHANG Tao WANG Fuhui 《上海航天(中英文)》 CSCD 2022年第1期111-121,共11页
With the implementation of new-generation launch vehicles,space stations,lunar and deep space exploration,etc.,the development of spacecraft structures will face new challenges. In order to reduce the spacecraft weigh... With the implementation of new-generation launch vehicles,space stations,lunar and deep space exploration,etc.,the development of spacecraft structures will face new challenges. In order to reduce the spacecraft weight and increase the payload,composite material structures will be widely used. It is difficult to evaluate the strength and life of composite materials due to their complex mechanism and various phenomena in damage and failure.Meanwhile,the structures of composite materials used in spacecrafts will bear complex loads,including the coupling loads of tension,pressure,bending,shear,and torsion. Static loads,thermal loads,and vibration loads may occur at the same time,which asks for verification requirements to ensure the structure safety. Therefore,it is necessary to carry out a systematic multi-level experimental study. In this paper,the building block approach (BBA) is used to investigate the multilevel composite material structures for spacecrafts. The advanced measurement technology is adopted based on digital image correlation (DIC) and piezoelectric and optical fiber sensors to measure the composite material structure deformation. The virtual experiment technology is applied to provide sufficient and reliable data for the evaluation of the composite material structures of spacecrafts. 展开更多
关键词 composite material structure SPACECRAFT multilevel test measurement evaluation
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Classification and Protective Measures of Geological Relics Based on Tourist Perception and Evaluation Perspective
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作者 Yonggang An,Heping Zhang,Tongde Li,Yunting Lu Life Science and Technology College,Central South University of Forestry and Technology,Changsha 410004,China. 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期297-297,共1页
The existing studies of geological relics have formed a classification system,which is based on geological relic cause factors.According to the geological relics of the tourist conception and perspective of tourism ev... The existing studies of geological relics have formed a classification system,which is based on geological relic cause factors.According to the geological relics of the tourist conception and perspective of tourism evaluation examples from Hunan Province,the author proposed the 展开更多
关键词 TOURIST CONCEPTION evaluation GEOLOGICAL RELICS protective measures
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OBJECTIVE IMAGE QUALITY MEASURES AND THEIR APPLICATIONS IN SEGMENTATION EVALUATION
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作者 Zhang Yujin (Department pf Electronic Engineering, Tsinghua University, 100084 Beijing) 《Journal of Electronics(China)》 1997年第2期97-103,共7页
Image segmentation is a critical step of image analysis. Segmentation evaluation is an effective procedure for studying the performance of segmentation techniques, in which quality measure plays an important role. Thi... Image segmentation is a critical step of image analysis. Segmentation evaluation is an effective procedure for studying the performance of segmentation techniques, in which quality measure plays an important role. This paper presents a group of new objective quality measures for segmentation evaluation and compares their performances. In addition, to verify the effectiveness of these new measures, an appropriate classification of segmentation is proposed. According to this classification, several representative algorithms from different categories are selected for comparison testing. Some valuable results are obtained and presented. 展开更多
关键词 IMAGE SEGMENTATION SEGMENTATION evaluation IMAGE QUALITY measures ALGORITHM CLASSIFICATION
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Supplier Evaluation Model Based on Fuzzy Measures and Choquet Integral
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作者 武建章 张强 桑圣举 《Journal of Beijing Institute of Technology》 EI CAS 2010年第1期109-114,共6页
To identify interactions among evaluation criteria and describe their importance,a new identification method making use of a fuzzy measure is presented.The relative weight and interaction degree of every evaluation cr... To identify interactions among evaluation criteria and describe their importance,a new identification method making use of a fuzzy measure is presented.The relative weight and interaction degree of every evaluation criteria pair are obtained by using the diamond pairwise comparison method.Based on comparison results,the maximum eigenvector method of analytic hierarchy process (AHP),the hierarchical clustering method,and the phi(s) transformation are utilized to generate values of the fuzzy measure for each subset of the evaluation criterion set.Overall evaluation on each supplier is aggregated by Choquet integral with respect to the fuzzy measure.Finally,an illustrative example demonstrates the practical feasibility and validity of the proposed method. 展开更多
关键词 fuzzy measure Choquet integral diamond pairwise comparison phi(s) transformation supplier evaluation
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INTERPOLATION METHODS FOR THE EVALUATION OF 2π-PERIODIC FINITE BAIRE MEASURE
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作者 Nicholas J. Daras (Hellenic Air Force Academy, Greece) 《Analysis in Theory and Applications》 2001年第2期1-27,共27页
We discuss the definition and effectiveness of a Padé-type approximation to 2π-periodic finite Baire measures on [-π,π]. In the first two sections we recall the definitions and basic properties of the Padr... We discuss the definition and effectiveness of a Padé-type approximation to 2π-periodic finite Baire measures on [-π,π]. In the first two sections we recall the definitions and basic properties of the Padré-type approximants to harmonic functions in the unit disk and to L p -functions on the unit circle. Section 3 deals with the extension of these definitions and properties to a finite 2π-periodic Baire measure. Finally, section 4 is devoted to a study of the convergence of a sequence of such approximants, in the weak star topology of measures. 展开更多
关键词 REAL PERIODIC FINITE BAIRE measure INTERPOLATION METHODS FOR THE evaluation OF 2 Re
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Context-Based Recommendation Approach for Measurement and Evaluation Projects
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作者 Hernan Molina Luis Olsina Gustavo Rossi 《Journal of Software Engineering and Applications》 2010年第12期1089-1106,共18页
Data, information and knowledge are recognized as useful assets for analysis, recommendation and decision making at any business level of an organization. Providing the right information for decision making considerin... Data, information and knowledge are recognized as useful assets for analysis, recommendation and decision making at any business level of an organization. Providing the right information for decision making considering different user-requirements, projects and situations is, however, a difficult issue. A frequently-neglected challenge is to cope with the influence of contextual issues affecting the success of outcomes and decisions. Particularly, when conducting quality evaluations in software organizations, it is of paramount importance to identify beforehand the contextual issues affecting outcomes and interpretations for measurement and evaluation projects. Therefore, the relevant context information should be clearly identified, specified and recorded for performing more robust analysis and recommendations. In this work, a domain-independent context model and a mechanism to integrate it to any application domain is presented. The context model is built upon a measurement and evaluation framework enabling quantification and semantic capabilities. The context model is then integrated in the mentioned framework itself to enable recommendations in meas- urement and evaluation projects. 展开更多
关键词 CONTEXT-AWARE CONTEXT Model RECOMMENDER System measureMENT evaluation C-INCAMI Framework
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Evaluation Strategies for Coupled GC-IMS Measurement including the Systematic Use of Parametrized ANN
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作者 Artur Scheinemann Stefanie Sielemann +1 位作者 Jorg Walter Theodor Doll 《Open Journal of Applied Sciences》 2012年第4期257-266,共10页
Data evaluation strategies for the novel coupled MCC-IMS sensory system are developed. Mayor attention to the plausibility of applied procedures and the feasibility of automation was paid. Three stages of extraction l... Data evaluation strategies for the novel coupled MCC-IMS sensory system are developed. Mayor attention to the plausibility of applied procedures and the feasibility of automation was paid. Three stages of extraction levels with increasing data reduction are presented for several fields of application. According to suitable extraction levels, real data were tested on various structures of artificial neural networks (ANN) with the result, that the computational levels must still be chosen by expertise, but subsequent processing and training can be fully automated. For the training of larger net- works a method of automated generation of secondary training data is presented which exceeds the quality of previous noise models by far. It is concluded that the combination of MCC-IMS as measuring instrument and ANNs as evalua- tion technique have high potential for industrial use in process monitoring. 展开更多
关键词 Gas CHROMATOGRAPHY Ion Mobility SPECTROMETRY GC-IMS MCC-IMS Artificial Neural Network measureMENT evaluation
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Evaluation of myocardial viability during cold storage by measurement of myocardual dielectric properties tanδm in radio frequency
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作者 段贵新 《外科研究与新技术》 2011年第4期289-289,共1页
Objective To study the mechanism of myocardial dielectric property changes in radio frequency during hypothermic preservation and explore myocardial viability evaluative method. Methods Hybrid young pigs ( 20 - 30 kg)... Objective To study the mechanism of myocardial dielectric property changes in radio frequency during hypothermic preservation and explore myocardial viability evaluative method. Methods Hybrid young pigs ( 20 - 30 kg) were used in the experiment. Heart arrest was in- 展开更多
关键词 evaluation of myocardial viability during cold storage by measurement of myocardual dielectric properties tan m in radio frequency
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Laboratory demonstration of geopotential measurement using transportable optical clocks 被引量:1
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作者 刘道信 曹健 +6 位作者 袁金波 崔凯枫 袁易 张平 晁思嘉 舒华林 黄学人 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第1期272-277,共6页
We report an experimental demonstration of geopotential difference measurement using a pair of transportable ^(40)Ca^(+) optical clocks(TOC-729-1 and TOC-729-3)in the laboratory,each of them has an uncertainty of 1.3&... We report an experimental demonstration of geopotential difference measurement using a pair of transportable ^(40)Ca^(+) optical clocks(TOC-729-1 and TOC-729-3)in the laboratory,each of them has an uncertainty of 1.3×10^(−17) and an instability of 4.8×10^(−15)/√τ.Referenced to a stationary clock of TOC-729-1,the geopotential difference measurements are realized by moving TOC-729-3 to three different locations and the relevant altitude differences are measured with uncertainties at the level of 20 cm.After correcting the systematic shifts(including gravitational red shift),the two-clock frequency difference is measured to be–0.7(2.2)×10^(−17),considering both the statistic(1.0×10^(−17))and the systematic(1.9×10^(−17))uncertainties.The frequency difference between these two clocks is within their respective uncertainties,verifying the reliability of transportable ^(40)Ca^(+) optical clocks at the low level of 10^(−17). 展开更多
关键词 geopotential difference measurement transportable optical clock repeatability evaluation of clocks
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Traffic Incident Management Performance Measures: Ranking Agencies on Roadway Clearance Time 被引量:1
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作者 Maroa Mumtarin Skylar Knickerbocker +1 位作者 Theresa Litteral Jonathan S. Wood 《Journal of Transportation Technologies》 2023年第3期353-368,共16页
This study develops a procedure to rank agencies based on their incident responses using roadway clearance times for crashes. This analysis is not intended to grade agencies but to assist in identifying agencies requi... This study develops a procedure to rank agencies based on their incident responses using roadway clearance times for crashes. This analysis is not intended to grade agencies but to assist in identifying agencies requiring more training or resources for incident management. Previous NCHRP reports discussed usage of different factors including incident severity, roadway characteristics, number of lanes involved and time of incident separately for estimating the performance. However, it does not tell us how to incorporate all the factors at the same time. Thus, this study aims to account for multiple factors to ensure fair comparisons. This study used 149,174 crashes from Iowa that occurred from 2018 to 2021. A Tobit regression model was used to find the effect of different variables on roadway clearance time. Variables that cannot be controlled directly by agencies such as crash severity, roadway type, weather conditions, lighting conditions, etc., were included in the analysis as it helps to reduce bias in the ranking procedure. Then clearance time of each crash is normalized into a base condition using the regression coefficients. The normalization makes the process more efficient as the effect of uncontrollable factors has already been mitigated. Finally, the agencies were ranked by their average normalized roadway clearance time. This ranking process allows agencies to track their performance of previous crashes, can be used in identifying low performing agencies that could use additional resources and training, and can be used to identify high performing agencies to recognize for their efforts and performance. 展开更多
关键词 Traffic Incident Management Roadway Clearance Time Performance measures and Ranking Agency Performance evaluation Tobit Regression Model
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Methods to Evaluate and Measure Power of Pneumatic System and Their Applications 被引量:5
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作者 Yan Shi Maolin Cai +1 位作者 Weiqing Xu Yixuan Wang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2019年第3期98-108,共11页
Pneumatic system has been widely used throughout industry, and it consumes more than billions kW h of electricity one year all over the world. So as to improve the efficiency of pneumatic system, its power evaluation ... Pneumatic system has been widely used throughout industry, and it consumes more than billions kW h of electricity one year all over the world. So as to improve the efficiency of pneumatic system, its power evaluation as well as measurement methods should be proposed, and their applicability should be validated. In this paper, firstly, power evaluation and measurement methods of pneumatic system were introduced for the first time. Secondly, based on the proposed methods, power distributions in pneumatic system was analyzed. Thirdly, through the analysis on pneumatic efficiencies of typical compressors and pneumatic components, the applicability of the proposed methods were validated. It can be concluded that, first of all, the proposed methods to evaluation and measurement the power of pneumatic system were efficient. Furthermore, the pneumatic power efficiencies of pneumatic system in the air production and cleaning procedure are respectively about 35%–75% and 85%–90%. Moreover, the pneumatic power efficiencies of pneumatic system in the transmission and consumption procedures are about 70%–85% and 10%–35%. And the total pneumatic power efficiency of pneumatic system is about 2%–20%, which varies largely with the system configuration. This paper provides a method to analyze and measure the power of pneumatic system, lay a foundation for the optimization and energy-saving design of pneumatic system. 展开更多
关键词 PNEUMATIC system Compressed AIR ENERGY ASSESSMENT measurement POWER evaluation
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Applying the AHP-FUZZY method to evaluate the measure effect of rubble roadbed engineering in permafrost regions of Qinghai-Tibet Plateau: a case study of Chaidaer-Muli Railway 被引量:1
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作者 Wei Cao Yu Sheng +1 位作者 Ji Chen JiChun Wu 《Research in Cold and Arid Regions》 CSCD 2018年第6期447-457,共11页
This article attempts to investigate the measure effect of rubble roadbed engineering in permafrost regions of Qinghai-Tibet Plateau. As a case study, Chaidaer-Muli Railway is used to evaluate the measure effect of ru... This article attempts to investigate the measure effect of rubble roadbed engineering in permafrost regions of Qinghai-Tibet Plateau. As a case study, Chaidaer-Muli Railway is used to evaluate the measure effect of rubble roadbed engineering in permafrost regions. The AHP(Analytic Hierarchy Process) method is thus employed to establish the evaluation indicator system. The evaluation factor is selected by analyzing the mutual relation between the permafrost environment and roadbed engineering. Thus, a hierarchical structure model is established based on the selected evaluation indices. Each factor is weighted to determine the status in the evaluation system, and grading standards are built for providing a basis for the evaluation. Then, the fuzzy mathematical method is introduced to evaluate the measure effect of rubble roadbed engineering in permafrost regions along the Chadaer-Muli Railway. Results show that most of the permafrost roadbed is in a preferable condition(b) along the Chaidaer-Muli Railway due to rubble engineering measures. This proportion reaches to 86.1%. The proportion in good(a), general(c) and poor states(d) are 0.0%, 7.5% and 6.4%, respectively, in all the evaluation sections along the Chaidaer-Muli Railway. Ground-temperature monitoring results are generally consistent with AHP-FUZZY evaluation results. This means that the AHP-FUZZY method can be applied to evaluate the effect of rubble roadbed engineering measures in permafrost regions. The effect evaluation of engineering measures will provide timely and effective feedback information for further engineering design. The series of engineering measures will more effectively protect permafrost stability. 展开更多
关键词 measure effect evaluation rubble roadbed engineering permafrost regions of Qinghai-Tibet Plateau AHP-FUZZY method Chaidaer-Muli Railway
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Comparison of GUF and Monte Carlo methods to evaluate task-specific uncertainty in laser tracker measurement 被引量:1
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作者 杨景照 李国喜 +2 位作者 吴宝中 龚京忠 王杰 《Journal of Central South University》 SCIE EI CAS 2014年第10期3793-3804,共12页
Measurement uncertainty plays an important role in laser tracking measurement analyses. In the present work, the guides to the expression of uncertainty in measurement(GUM) uncertainty framework(GUF) and its supplemen... Measurement uncertainty plays an important role in laser tracking measurement analyses. In the present work, the guides to the expression of uncertainty in measurement(GUM) uncertainty framework(GUF) and its supplement, the Monte Carlo method, were used to estimate the uncertainty of task-specific laser tracker measurements. First, the sources of error in laser tracker measurement were analyzed in detail, including instruments, measuring network fusion, measurement strategies, measurement process factors(such as the operator), measurement environment, and task-specific data processing. Second, the GUM and Monte Carlo methods and their application to laser tracker measurement were presented. Finally, a case study involving the uncertainty estimation of a cylindricity measurement process using the GUF and Monte Carlo methods was illustrated. The expanded uncertainty results(at 95% confidence levels) obtained with the Monte Carlo method are 0.069 mm(least-squares criterion) and 0.062 mm(minimum zone criterion), respectively, while with the GUM uncertainty framework, none but the result of least-squares criterion can be got, which is 0.071 mm. Thus, the GUM uncertainty framework slightly underestimates the overall uncertainty by 10%. The results demonstrate that the two methods have different characteristics in task-specific uncertainty evaluations of laser tracker measurements. The results indicate that the Monte Carlo method is a practical tool for applying the principle of propagation of distributions and does not depend on the assumptions and limitations required by the law of propagation of uncertainties(GUF). These features of the Monte Carlo method reduce the risk of an unreliable measurement of uncertainty estimation, particularly in cases of complicated measurement models, without the need to evaluate partial derivatives. In addition, the impact of sampling strategy and evaluation method on the uncertainty of the measurement results can also be taken into account with Monte Carlo method, which plays a guiding role in measurement planning. 展开更多
关键词 task-specific uncertainty laser tracker measurement uncertainty evaluation Monte Carlo method uncertainy framework(GUF)
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