It is well recognized that Structural Health Monitoring(SHM)reliability evaluation is a key aspect that needs to be urgently addressed to promote the wide application of SHM methods.However,the existing studies typica...It is well recognized that Structural Health Monitoring(SHM)reliability evaluation is a key aspect that needs to be urgently addressed to promote the wide application of SHM methods.However,the existing studies typically transfer the Non-Destructive Testing/Evaluation(NDT/E)reliability metrics to SHM without a systematic analysis of where these metrics originated.Seldom attentions are paid to the evaluation conditions which are very important to apply these metrics.Aimed at this issue,a new condition control-based Dual-Reliability Evaluation(Dual-RE)method for SHM is proposed.This new method is proposed based on a systematic analysis of the whole framework of reliability evaluation from instrument to NDT,and emphasis is paid to the evaluation condition control.Based on these analyses,considering the special online application scenario of SHM,the proposed Dual-RE method contains two key components:Integrated Sensor-based SHM-RE(IS-SHM-RE)and Critical Service Condition-based SHM-RE(CSC-SHM-RE).ISSHM-RE evaluates the reliability of integrated SHM sensor and system themselves under approximate repeatability conditions,while CSC-SHM-RE assesses SHM reliability under the dominant uncertainties during service,namely intermediate conditions.To demonstrate the Dual-RE,crack monitoring by using the Guided Wave-based-SHM(GW-SHM)on aircraft lug structures is taken as a case study.Both the crack detection and sizing performance are evaluated from accuracy and uncertainty.展开更多
Lifetime isone of the important indicators of automotive proton exchange membrane fuel cells. People used to evaluate the lifetime of vehicular fuel cells by laboratory tests or road tests that usually take thousands ...Lifetime isone of the important indicators of automotive proton exchange membrane fuel cells. People used to evaluate the lifetime of vehicular fuel cells by laboratory tests or road tests that usually take thousands hours even years. In order to achieve a rapid evaluation technique and to seek lifetime extension methods, a lifetime calculation formation was drawn out in consideration of the vehicle driving cycle and the working condition factors. Bench experiments were individually carried out on two fuel-cell stacks same as ones applied on vehicle, and the performance decay rates of the two stacks were obtained under four operation conditions of changing load cycle, start-stop cycle, idling and heavy load. As a result, the predicted lifetimes rather conform to the actual running status in road test. And the research on the fuel cell performance decay rates under different load conditions was also done. Consequently, an unexpected finding was discovered that operating under micro-current has an effect on recovering fuel cell performance. The vehicle fuel cell rapid assessment method only requires four laboratory tests of driving cycle, load cycle, idle operating conditions and heavy load conditions, and the whole process merely lasts less than 250 h. These experimental results can be used to predict the vehicular fuel cell lifetimes on various utility models or driving cycles, therefore to optimize the application model to prolong the fuel cell lifetime. Actually in the experiment, it has already been proved successfully that the fuel cell lifetime could be extended from 1 100 h to 2 600 h by optimizing operating mode. The quick evaluation method is helpful to develop extended life fuel cell and to deplete fuel cell for a longer time.展开更多
Land surface hydrothermal conditions(LSHCs) reflect land surface moisture and heat conditions, and play an important role in energy and water cycles in soil-plant-atmosphere continuum. Based on comparison of four eval...Land surface hydrothermal conditions(LSHCs) reflect land surface moisture and heat conditions, and play an important role in energy and water cycles in soil-plant-atmosphere continuum. Based on comparison of four evaluation methods(namely, the classic statistical method, geostatistical method, information theory method, and fractal method), this study proposed a new scheme for evaluating the spatial heterogeneity of LSHCs. This scheme incorporates diverse remotely sensed surface parameters, e.g., leaf area index-LAI, the normalized difference vegetation index-NDVI, net radiation-Rn, and land surface temperature-LST. The LSHCs can be classified into three categories, namely homogeneous, moderately heterogeneous and highly heterogeneous based on the remotely sensed LAI data with a 30 m spatial resolution and the combination of normalized information entropy(S’) and coefficient of variation(CV). Based on the evaluation scheme, the spatial heterogeneity of land surface hydrothermal conditions at six typical flux observation stations in the Heihe River Basin during the vegetation growing season were evaluated. The evaluation results were consistent with the land surface type characteristics exhibited by Google Earth imagery and spatial heterogeneity assessed by high resolution remote sensing evapotranspiration data. Impact factors such as precipitation and irrigation events, spatial resolutions of remote sensing data, heterogeneity in the vertical direction, topography and sparse vegetation could also affect the evaluation results. For instance, short-term changes(precipitation and irrigation events) in the spatial heterogeneity of LSHCs can be diagnosed by energy factors, while long-term changes can be indicated by vegetation factors. The spatial heterogeneity of LSHCs decreases when decreasing the spatial resolution of remote sensing data. The proposed evaluation scheme would be useful for the quantification of spatial heterogeneity of LSHCs over flux observation stations toward the global scale, and also contribute to the improvement of the accuracy of estimation and validation for remotely sensed(or model simulated) evapotranspiration.展开更多
This article investigates the comparative analysis of the facility present condition (FPC) of selected health and educational buildings in Rivers State. State funded hospitals and schools (14 functional out of 23 gene...This article investigates the comparative analysis of the facility present condition (FPC) of selected health and educational buildings in Rivers State. State funded hospitals and schools (14 functional out of 23 general hospitals and 2 out of 3 tertiary schools) were selected for the study. The general hospital is a secondary health facility designed to bring health care services close to citizens especially those in rural communities. These facilities were inherited from the colonial masters in 1960. An assessment visit in2016 found the 23 general hospitals completely dilapidated and abandoned. However, rehabilitation intervention was carried out by the government in 2020. This scenario was quite different with the schools. Thus, this study is to increase the awareness of facility operators on building maintenance. A purposive sampling technique was used in selecting the hospitals and schools, while simple random sampling was adopted for questionnaire distribution to 300 respondents. The instrument reliability and validity were ascertained using Cronbach Alpha and face validity. The instrument obtained information about the status of the facility present condition. SPSS and Microsoft Xlstat were used to obtain the mean and frequency distribution of the responses. Comparative analysis was conducted to understand the FPC of the schools and hospitals. Z-test was deployed to ascertain if there was a significant difference in the FPC between the two institutions. Checklist was adopted to confirm the findings. The result from the survey showed that schools have better FPC than hospitals.展开更多
Epoxy asphalt concrete has been one of the mainstream technology of steel deck pavement in China. But little specification about evaluation system for its distress condition has been researched and maintenance was sti...Epoxy asphalt concrete has been one of the mainstream technology of steel deck pavement in China. But little specification about evaluation system for its distress condition has been researched and maintenance was still unsystematic. The section weight coefficient of different distress is proposed by analyzing the applicability of the “Highway Performance Assessment Standards”. Indexes mainly including SDPCI PDR and PCR are presented to evaluate its distress condition. The evaluation system and maintenance plan decision tree were recommended which can assist scientific maintenance of epoxy asphalt steel deck pavement.展开更多
Establishing a reasonable evaluation index system is the basis and premise for the scientific evaluation of geographic national conditions. By analyzing the DPSIR model and its correlation and relation with the evalua...Establishing a reasonable evaluation index system is the basis and premise for the scientific evaluation of geographic national conditions. By analyzing the DPSIR model and its correlation and relation with the evaluation index system, the indexes for geographic national conditions were selected from the aspects of resources, ecology, environment, economy, society, etc to build an evaluation index system for geographic national conditions that consists of three hierarchies： index, criterion, and target levels. Furthermore, the index system was analyzed in terms of index integrity, low overlapping of elements, non-existence of isolated indexes, hierarchy of index system, etc., for the purpose of demonstrating that the DPSIR model-based evaluation index system for geographic national conditions meets the principles of index system establishment.展开更多
The condition of weightes non-dictatorship is extended and a comprehensive evaluae method emboding self-determinate which is combined with competitive view optimization principles is built. The basic process includes ...The condition of weightes non-dictatorship is extended and a comprehensive evaluae method emboding self-determinate which is combined with competitive view optimization principles is built. The basic process includes simulating the model of economic man＇s self-benefit bahaviors, taking the place of experts to evaluate, bringing in the model of minimizing the sum of included angles to integrate the information of multiple objects and put the objects in order finally. The method has the advangtages of less dependendence on the subjective information, plenty of information, fair process and simple caculating. Finally, an application example is given to illustrate the effectiveness of the proposed method.展开更多
Based on the monitoring results of environmental quality in the sea area near the Aojiang estuary in Wenzou during 2010-2012,the present situation of environmental quality in the sea area was analyzed and evaluated. T...Based on the monitoring results of environmental quality in the sea area near the Aojiang estuary in Wenzou during 2010-2012,the present situation of environmental quality in the sea area was analyzed and evaluated. The results show that p H,DO,CODMn,petroleum,and heavy metals( Cu,Pb,Zn,Cd,Hg,As and Cr) in the sea area near the Aojiang estuary did not exceed the second-class standard of Seawater Quality Standard( GB 3097-1997),but both inorganic nitrogen and reactive phosphate in the sea area exceeded the second-class standard seriously,and the water quality of the sea area was in an eutrophic state; domestic sewage and fertilizer loss were the main sources of nitrogen and phosphorus. The standard index of most evaluation factors of sediment quality except for Zn was smaller than 1,meeting the demands of sediment quality for environmental protection.展开更多
This study evaluated the simulation performance of mesoscale convective system(MCS)-induced precipitation,focusing on three selected cases that originated from the Yellow Sea and propagated toward the Korean Peninsula...This study evaluated the simulation performance of mesoscale convective system(MCS)-induced precipitation,focusing on three selected cases that originated from the Yellow Sea and propagated toward the Korean Peninsula.The evaluation was conducted for the European Centre for Medium-Range Weather Forecasts(ECMWF)and National Centers for Environmental Prediction(NCEP)analysis data,as well as the simulation result using them as initial and lateral boundary conditions for the Weather Research and Forecasting model.Particularly,temperature and humidity profiles from 3D dropsonde observations from the National Center for Meteorological Science of the Korea Meteorological Administration served as validation data.Results showed that the ECMWF analysis consistently had smaller errors compared to the NCEP analysis,which exhibited a cold and dry bias in the lower levels below 850 hPa.The model,in terms of the precipitation simulations,particularly for high-intensity precipitation over the Yellow Sea,demonstrated higher accuracy when applying ECMWF analysis data as the initial condition.This advantage also positively influenced the simulation of rainfall events on the Korean Peninsula by reasonably inducing convective-favorable thermodynamic features(i.e.,warm and humid lower-level atmosphere)over the Yellow Sea.In conclusion,this study provides specific information about two global analysis datasets and their impacts on MCS-induced heavy rainfall simulation by employing dropsonde observation data.Furthermore,it suggests the need to enhance the initial field for MCS-induced heavy rainfall simulation and the applicability of assimilating dropsonde data for this purpose in the future.展开更多
Automated pavement condition survey is of critical importance to road network management.There are three primary tasks involved in pavement condition surveys,namely data collection,data processing and condition evalua...Automated pavement condition survey is of critical importance to road network management.There are three primary tasks involved in pavement condition surveys,namely data collection,data processing and condition evaluation.Artificial intelligence(AI)has achieved many breakthroughs in almost every aspect of modern technology over the past decade,and undoubtedly offers a more robust approach to automated pavement condition survey.This article aims to provide a comprehensive review on data collection systems,data processing algorithms and condition evaluation methods proposed between 2010 and 2023 for intelligent pavement condition survey.In particular,the data collection system includes AI-driven hardware devices and automated pavement data collection vehicles.The AI-driven hardware devices including right-of-way(ROW)cameras,ground penetrating radar(GPR)devices,light detection and ranging(LiDAR)devices,and advanced laser imaging systems,etc.These different hardware components can be selectively mounted on a vehicle to simultaneously collect multimedia information about the pavement.In addition,this article pays close attention to the application of artificial intelligence methods in detecting pavement distresses,measuring pavement roughness,identifying pavement rutting,analyzing skid resistance and evaluating structural strength of pavements.Based upon the analysis of a variety of the state-of-the-art artificial intelligence methodologies,remaining challenges and future needs with respect to intelligent pavement condition survey are discussed eventually.展开更多
The present study aimed to design,develop,operate and evaluate a sightseeing spot recommendation system as a smart tourism tool that gathers and accumulates sightseeing spot information and considers personal preferen...The present study aimed to design,develop,operate and evaluate a sightseeing spot recommendation system as a smart tourism tool that gathers and accumulates sightseeing spot information and considers personal preferences as well as priority conditions to support tourism activities,especially in urban tourist areas.The system was developed by integrating web-geographic information systems(Web-GIS),the recommendation system and the evaluation system.Additionally,the system was operated for 4 weeks in the central part of Yokohama City in Kanagawa Prefecture,Japan,and the total number of users was 62.Based on the results of the web questionnaire survey,the system was highly useful for sightseeing activities,and further utilization of each function can be expected by continuing the operation.From the results of access analysis of users’log data,it is evident that the system has been used by different types of information terminals just as it was designed for,and that the system has been used according to the purpose of the present study,which is to support the sightseeing activities of users.However,the number of visits to pages related to the evaluation function of sightseeing spots and submitting function of new sightseeing spot information was low.This may improve if the system operation is conducted on a long-term basis.展开更多
The new Austrian tunneling method （NATM） is widely applied in design and construction of underground engineering projects. When the type and distribution of unfavorable geological bodies （UGBs） associated with the...The new Austrian tunneling method （NATM） is widely applied in design and construction of underground engineering projects. When the type and distribution of unfavorable geological bodies （UGBs） associated with their influences on geoengineering are complicated or unfortunately are overlooked, we should pay more attentions to internal features of rocks grades IV and V （even in local but mostly controlling zones）. With increasing attentions to the characteristics, mechanism and influences of engineering construction-triggered geohazards, it is crucial to fully understand the disturbance of these geohazards on project construction. A reasonable determination method in construction procedure, i.e. the shape of working face, the type of engineering support and the choice of feasible procedure, should be considered in order to mitigate the construction-triggered geohazards. Due to their high sensitivity to groundwater and in-situ stress, various UGBs exhibit hysteretic nature and failure modes. To give a complete understanding on the internal causes, the emphasis on advanced comprehensive geological forecasting and overall reinforcement treatment is therefore of more practical significance. Compre- hensive evaluation of influential factors, identification of UGB, and measures of discontinuity dynamic controlling comprises the geoengineering condition evaluation and dynamic controlling method. In a case of a cut slope, the variations of UGBs and the impacts of key environmental factors are presented, where more severe construction-triggered geohazards emerged in construction stage than those predicted in design and field investigation stages. As a result, the weight ratios of different influential factors with respect to field investigation, design and construction are obtained.展开更多
Presentations are activities in which people show,describe,or explain something to a group of people.They are often used in American school classrooms.On the base of the author’s referring to literature,observing cla...Presentations are activities in which people show,describe,or explain something to a group of people.They are often used in American school classrooms.On the base of the author’s referring to literature,observing classes and co-teaching practice,presentations are suggested to be applied to EFL classrooms to help students improve their speaking levels and integrate their language skills efficiently.In point of ways of organizing,presentations can be divided into three types:controlled,guided and free ones.While in point of ways of applying,they can be divided into five types:interactive,role-plays,interview,note-taking,and discourse analysis ones.Thus different types of presentations should be adopted according to EFL students’different levels and different communication purposes.Topics relating to EFL students’study,life and interest are practical for presentations.Important aspects of presentations include:posture and presence,eye contact with the audience,volume and voice projection,rate of speech,use of audiovisual aids,vitality,adherence to the topic,keeping track of time,natural delivery,fluency and accuracy,the quantity of information presented,the way the topic was handled and how the questions are handled in the post-presentation session and so on.Presentation evaluations can be done by the teacher or together with student peers.展开更多
The purpose of this study is focused on development of an online monitoring system for measuring and evaluating the cutting condition as the ID-blade saw is cutting a silicon ingot. First,the cutting experiments are c...The purpose of this study is focused on development of an online monitoring system for measuring and evaluating the cutting condition as the ID-blade saw is cutting a silicon ingot. First,the cutting experiments are carried out and the cutting signals during the blade slicing a six-inch ingot are measured by a 3-axes load sensor which is mounted on the top of the ingot. To evaluate the blade condition in slicing,a novel data processing method,combining the discrete Fourier transform(DFT) with the discrete Wavelet transform(DWT),is proposed in this paper for extracting the components due to the rotation of the blade and the cutting impedance. To validate the effect of the method,four ID-blades with three different types of the blade edge are used and discussed. The obtained results show that the component induced from the rotation and the component due to the blade slicing can be extracted efficiently by introduction of the proposed method. Furthermore,a simple online monitoring system,which consists of a 3-axes load sensor or acceleration sensor,DC cuts high-pass filter,and AD converter embedded microcomputer,is designed. The estimated cutting condition information obtained from the proposed monitoring system can be used as a feedback signal to the slicing machine for production of high quality wafer.展开更多
This paper presents the ageing mechanism of fuse in nuclear power plant in detail. Metal Electromigration is identified as the dominant ageing mechanism. On this basis, the dominant status indicators, temperature and ...This paper presents the ageing mechanism of fuse in nuclear power plant in detail. Metal Electromigration is identified as the dominant ageing mechanism. On this basis, the dominant status indicators, temperature and resistance of fuse were ensured, and current-temperature curve was proposed. The infrared thermal imaging technology was used to inspect the ageing condition and prove the current-temperature curve. Finally, the accelerated ageing testing was conducted abiding by the dominant ageing mechanism, and the lifetime was evaluated.展开更多
The present development situation of transgenic crops and their effect on ecological environment are introduced in the paper.Some relevant strategies for their future and how to control the risks of ecological environ...The present development situation of transgenic crops and their effect on ecological environment are introduced in the paper.Some relevant strategies for their future and how to control the risks of ecological environment are presented.展开更多
Based on the geochemical characteristics of oil-cracking gas and kerogen-cracking gas revealed by simu-lation experiments and the chemical composition of natural gases in actual gas reservoirs,two kinds of natural gas...Based on the geochemical characteristics of oil-cracking gas and kerogen-cracking gas revealed by simu-lation experiments and the chemical composition of natural gases in actual gas reservoirs,two kinds of natural gases with different relationships between C_(2)/C_(3)and C_(1)/C_(2),C_(2)/C_(3)and C_(1)/C_(3),C_(2)/C_(3)and 100×C_(1)/(C_(1)-C5)were identified in the Tarim Basin,and proposed further by the authors.The relationship charts of C_(2)/C_(3)and C_(1)/C_(2),C_(2)/C_(3)and C_(1)/C_(3),C_(2)/C_(3)and 100×C_(1)/(C_(1)-C_(5))can be used to effectively distinguish oil-cracking gas from kerogen-cracking gas.Petro-leum geological analysis of the oil-cracking gas reservoirs showed that the distribution of oil-cracking gas is mostly related with deep-seated faults or faults with a large fault throw,and the burial depth of paleo-oil reservoir is rela-tively high;crude oil-cracking gas resources have been evaluated by using both forward and inversion methods.The plots of C_(2)/C_(3)vs.C_(1)/C_(2),C_(2)/C_(3)vs.C_(1)/C_(3),and C_(2)/C_(3)vs.100×C_(1)/(C_(1)-C_(5))were used to distinguish between oil-crack-ing gas and kerogen-cracking gas,and estimate the mixed ratios of the two kinds of natural gases in the main gas reservoirs of the platform area.展开更多
Increasing renewable energy targets globally has raised the requirement for the efficient and profitable operation of solar photovoltaic(PV)systems.In light of this requirement,this paper provides a path for evaluatin...Increasing renewable energy targets globally has raised the requirement for the efficient and profitable operation of solar photovoltaic(PV)systems.In light of this requirement,this paper provides a path for evaluating the operating condition and improving the power output of the PV system in a grid integrated environment.To achieve this,different types of faults in grid-connected PV systems(GCPVs)and their impact on the energy loss associated with the electrical network are analyzed.A data-driven approach using neural networks(NNs)is proposed to achieve root cause analysis and localize the fault to the component level in the system.The localized fault condition is combined with a parallel operation of adaptive neurofuzzy inference units(ANFIUs)to develop a power mismatch-based control unit(PMCU)for improving the power output of the GCPV.To develop the proposed framework,a 10-kW single-phase GCPV is simulated for training the NN-based anomaly detection approach with 14 deviation signals.Further,the developed algorithm is combined with the PMCU implemented with the experimental setup of GCPV.The results identified 98.2%training accuracy and 43000 observations/sec prediction speed for the trained classifier,and improved power output with reduced voltage and current harmonics for the grid-connected PV operation.展开更多
基金the support from National Natural Science Foundation of China(No.52275153)the Frontier Technologies R&D Program of Jiangsu,China(No.BF2024068)+1 种基金The Fund of Prospective Layout of Scientific Research for Nanjing University of Aeronautics and Astronautics,ChinaResearch Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures(Nanjing University of Aeronautics and Astronautics),China(Nos.MCAS-I-0425K01,MCAS-I-0423G01)。
文摘It is well recognized that Structural Health Monitoring(SHM)reliability evaluation is a key aspect that needs to be urgently addressed to promote the wide application of SHM methods.However,the existing studies typically transfer the Non-Destructive Testing/Evaluation(NDT/E)reliability metrics to SHM without a systematic analysis of where these metrics originated.Seldom attentions are paid to the evaluation conditions which are very important to apply these metrics.Aimed at this issue,a new condition control-based Dual-Reliability Evaluation(Dual-RE)method for SHM is proposed.This new method is proposed based on a systematic analysis of the whole framework of reliability evaluation from instrument to NDT,and emphasis is paid to the evaluation condition control.Based on these analyses,considering the special online application scenario of SHM,the proposed Dual-RE method contains two key components:Integrated Sensor-based SHM-RE(IS-SHM-RE)and Critical Service Condition-based SHM-RE(CSC-SHM-RE).ISSHM-RE evaluates the reliability of integrated SHM sensor and system themselves under approximate repeatability conditions,while CSC-SHM-RE assesses SHM reliability under the dominant uncertainties during service,namely intermediate conditions.To demonstrate the Dual-RE,crack monitoring by using the Guided Wave-based-SHM(GW-SHM)on aircraft lug structures is taken as a case study.Both the crack detection and sizing performance are evaluated from accuracy and uncertainty.
基金supported by National Hi-tech Research and Development Program of China (863 Program, Grant No. 2007AA05Z125)
文摘Lifetime isone of the important indicators of automotive proton exchange membrane fuel cells. People used to evaluate the lifetime of vehicular fuel cells by laboratory tests or road tests that usually take thousands hours even years. In order to achieve a rapid evaluation technique and to seek lifetime extension methods, a lifetime calculation formation was drawn out in consideration of the vehicle driving cycle and the working condition factors. Bench experiments were individually carried out on two fuel-cell stacks same as ones applied on vehicle, and the performance decay rates of the two stacks were obtained under four operation conditions of changing load cycle, start-stop cycle, idling and heavy load. As a result, the predicted lifetimes rather conform to the actual running status in road test. And the research on the fuel cell performance decay rates under different load conditions was also done. Consequently, an unexpected finding was discovered that operating under micro-current has an effect on recovering fuel cell performance. The vehicle fuel cell rapid assessment method only requires four laboratory tests of driving cycle, load cycle, idle operating conditions and heavy load conditions, and the whole process merely lasts less than 250 h. These experimental results can be used to predict the vehicular fuel cell lifetimes on various utility models or driving cycles, therefore to optimize the application model to prolong the fuel cell lifetime. Actually in the experiment, it has already been proved successfully that the fuel cell lifetime could be extended from 1 100 h to 2 600 h by optimizing operating mode. The quick evaluation method is helpful to develop extended life fuel cell and to deplete fuel cell for a longer time.
基金the auspices of National Natural Science Foundation of China(No.41531174)National Basic Research Program of China(No.2015CB953702)。
文摘Land surface hydrothermal conditions(LSHCs) reflect land surface moisture and heat conditions, and play an important role in energy and water cycles in soil-plant-atmosphere continuum. Based on comparison of four evaluation methods(namely, the classic statistical method, geostatistical method, information theory method, and fractal method), this study proposed a new scheme for evaluating the spatial heterogeneity of LSHCs. This scheme incorporates diverse remotely sensed surface parameters, e.g., leaf area index-LAI, the normalized difference vegetation index-NDVI, net radiation-Rn, and land surface temperature-LST. The LSHCs can be classified into three categories, namely homogeneous, moderately heterogeneous and highly heterogeneous based on the remotely sensed LAI data with a 30 m spatial resolution and the combination of normalized information entropy(S’) and coefficient of variation(CV). Based on the evaluation scheme, the spatial heterogeneity of land surface hydrothermal conditions at six typical flux observation stations in the Heihe River Basin during the vegetation growing season were evaluated. The evaluation results were consistent with the land surface type characteristics exhibited by Google Earth imagery and spatial heterogeneity assessed by high resolution remote sensing evapotranspiration data. Impact factors such as precipitation and irrigation events, spatial resolutions of remote sensing data, heterogeneity in the vertical direction, topography and sparse vegetation could also affect the evaluation results. For instance, short-term changes(precipitation and irrigation events) in the spatial heterogeneity of LSHCs can be diagnosed by energy factors, while long-term changes can be indicated by vegetation factors. The spatial heterogeneity of LSHCs decreases when decreasing the spatial resolution of remote sensing data. The proposed evaluation scheme would be useful for the quantification of spatial heterogeneity of LSHCs over flux observation stations toward the global scale, and also contribute to the improvement of the accuracy of estimation and validation for remotely sensed(or model simulated) evapotranspiration.
文摘This article investigates the comparative analysis of the facility present condition (FPC) of selected health and educational buildings in Rivers State. State funded hospitals and schools (14 functional out of 23 general hospitals and 2 out of 3 tertiary schools) were selected for the study. The general hospital is a secondary health facility designed to bring health care services close to citizens especially those in rural communities. These facilities were inherited from the colonial masters in 1960. An assessment visit in2016 found the 23 general hospitals completely dilapidated and abandoned. However, rehabilitation intervention was carried out by the government in 2020. This scenario was quite different with the schools. Thus, this study is to increase the awareness of facility operators on building maintenance. A purposive sampling technique was used in selecting the hospitals and schools, while simple random sampling was adopted for questionnaire distribution to 300 respondents. The instrument reliability and validity were ascertained using Cronbach Alpha and face validity. The instrument obtained information about the status of the facility present condition. SPSS and Microsoft Xlstat were used to obtain the mean and frequency distribution of the responses. Comparative analysis was conducted to understand the FPC of the schools and hospitals. Z-test was deployed to ascertain if there was a significant difference in the FPC between the two institutions. Checklist was adopted to confirm the findings. The result from the survey showed that schools have better FPC than hospitals.
基金Sponsored by the Major Science and Technology Special Traffic and Transportation in Jiangsu Province(Grant No.2014Y02)the Jiangsu Natural Science Foundation(Grant Nos.BK20180113 and BK20181112)
文摘Epoxy asphalt concrete has been one of the mainstream technology of steel deck pavement in China. But little specification about evaluation system for its distress condition has been researched and maintenance was still unsystematic. The section weight coefficient of different distress is proposed by analyzing the applicability of the “Highway Performance Assessment Standards”. Indexes mainly including SDPCI PDR and PCR are presented to evaluate its distress condition. The evaluation system and maintenance plan decision tree were recommended which can assist scientific maintenance of epoxy asphalt steel deck pavement.
基金Supported by the National Natural Science Foundation of China(41401462)the Independent Innovation Project of the Changjiang Institute of Survey,Planning,Design and Research(CX2015Z08)
文摘Establishing a reasonable evaluation index system is the basis and premise for the scientific evaluation of geographic national conditions. By analyzing the DPSIR model and its correlation and relation with the evaluation index system, the indexes for geographic national conditions were selected from the aspects of resources, ecology, environment, economy, society, etc to build an evaluation index system for geographic national conditions that consists of three hierarchies： index, criterion, and target levels. Furthermore, the index system was analyzed in terms of index integrity, low overlapping of elements, non-existence of isolated indexes, hierarchy of index system, etc., for the purpose of demonstrating that the DPSIR model-based evaluation index system for geographic national conditions meets the principles of index system establishment.
基金supported by the National Natural Science Foundation of China(70801013)LNSTF for doc-tor(20081020).
文摘The condition of weightes non-dictatorship is extended and a comprehensive evaluae method emboding self-determinate which is combined with competitive view optimization principles is built. The basic process includes simulating the model of economic man＇s self-benefit bahaviors, taking the place of experts to evaluate, bringing in the model of minimizing the sum of included angles to integrate the information of multiple objects and put the objects in order finally. The method has the advangtages of less dependendence on the subjective information, plenty of information, fair process and simple caculating. Finally, an application example is given to illustrate the effectiveness of the proposed method.
文摘Based on the monitoring results of environmental quality in the sea area near the Aojiang estuary in Wenzou during 2010-2012,the present situation of environmental quality in the sea area was analyzed and evaluated. The results show that p H,DO,CODMn,petroleum,and heavy metals( Cu,Pb,Zn,Cd,Hg,As and Cr) in the sea area near the Aojiang estuary did not exceed the second-class standard of Seawater Quality Standard( GB 3097-1997),but both inorganic nitrogen and reactive phosphate in the sea area exceeded the second-class standard seriously,and the water quality of the sea area was in an eutrophic state; domestic sewage and fertilizer loss were the main sources of nitrogen and phosphorus. The standard index of most evaluation factors of sediment quality except for Zn was smaller than 1,meeting the demands of sediment quality for environmental protection.
基金supported by the Korea Meteorological Administration Research and Development Program “Developing Application Technology for Atmospheric Research Aircraft” (Grant No. KMA2018-00222)
文摘This study evaluated the simulation performance of mesoscale convective system(MCS)-induced precipitation,focusing on three selected cases that originated from the Yellow Sea and propagated toward the Korean Peninsula.The evaluation was conducted for the European Centre for Medium-Range Weather Forecasts(ECMWF)and National Centers for Environmental Prediction(NCEP)analysis data,as well as the simulation result using them as initial and lateral boundary conditions for the Weather Research and Forecasting model.Particularly,temperature and humidity profiles from 3D dropsonde observations from the National Center for Meteorological Science of the Korea Meteorological Administration served as validation data.Results showed that the ECMWF analysis consistently had smaller errors compared to the NCEP analysis,which exhibited a cold and dry bias in the lower levels below 850 hPa.The model,in terms of the precipitation simulations,particularly for high-intensity precipitation over the Yellow Sea,demonstrated higher accuracy when applying ECMWF analysis data as the initial condition.This advantage also positively influenced the simulation of rainfall events on the Korean Peninsula by reasonably inducing convective-favorable thermodynamic features(i.e.,warm and humid lower-level atmosphere)over the Yellow Sea.In conclusion,this study provides specific information about two global analysis datasets and their impacts on MCS-induced heavy rainfall simulation by employing dropsonde observation data.Furthermore,it suggests the need to enhance the initial field for MCS-induced heavy rainfall simulation and the applicability of assimilating dropsonde data for this purpose in the future.
基金the National Natural Science Foundation of China(grant no.51208419).
文摘Automated pavement condition survey is of critical importance to road network management.There are three primary tasks involved in pavement condition surveys,namely data collection,data processing and condition evaluation.Artificial intelligence(AI)has achieved many breakthroughs in almost every aspect of modern technology over the past decade,and undoubtedly offers a more robust approach to automated pavement condition survey.This article aims to provide a comprehensive review on data collection systems,data processing algorithms and condition evaluation methods proposed between 2010 and 2023 for intelligent pavement condition survey.In particular,the data collection system includes AI-driven hardware devices and automated pavement data collection vehicles.The AI-driven hardware devices including right-of-way(ROW)cameras,ground penetrating radar(GPR)devices,light detection and ranging(LiDAR)devices,and advanced laser imaging systems,etc.These different hardware components can be selectively mounted on a vehicle to simultaneously collect multimedia information about the pavement.In addition,this article pays close attention to the application of artificial intelligence methods in detecting pavement distresses,measuring pavement roughness,identifying pavement rutting,analyzing skid resistance and evaluating structural strength of pavements.Based upon the analysis of a variety of the state-of-the-art artificial intelligence methodologies,remaining challenges and future needs with respect to intelligent pavement condition survey are discussed eventually.
文摘The present study aimed to design,develop,operate and evaluate a sightseeing spot recommendation system as a smart tourism tool that gathers and accumulates sightseeing spot information and considers personal preferences as well as priority conditions to support tourism activities,especially in urban tourist areas.The system was developed by integrating web-geographic information systems(Web-GIS),the recommendation system and the evaluation system.Additionally,the system was operated for 4 weeks in the central part of Yokohama City in Kanagawa Prefecture,Japan,and the total number of users was 62.Based on the results of the web questionnaire survey,the system was highly useful for sightseeing activities,and further utilization of each function can be expected by continuing the operation.From the results of access analysis of users’log data,it is evident that the system has been used by different types of information terminals just as it was designed for,and that the system has been used according to the purpose of the present study,which is to support the sightseeing activities of users.However,the number of visits to pages related to the evaluation function of sightseeing spots and submitting function of new sightseeing spot information was low.This may improve if the system operation is conducted on a long-term basis.
基金support by the National Natural Science Foundation of China (No. 41372324)support from the Chinese Special Funds for Major State Basic Research Project under Grant No. 2010CB732001
文摘The new Austrian tunneling method （NATM） is widely applied in design and construction of underground engineering projects. When the type and distribution of unfavorable geological bodies （UGBs） associated with their influences on geoengineering are complicated or unfortunately are overlooked, we should pay more attentions to internal features of rocks grades IV and V （even in local but mostly controlling zones）. With increasing attentions to the characteristics, mechanism and influences of engineering construction-triggered geohazards, it is crucial to fully understand the disturbance of these geohazards on project construction. A reasonable determination method in construction procedure, i.e. the shape of working face, the type of engineering support and the choice of feasible procedure, should be considered in order to mitigate the construction-triggered geohazards. Due to their high sensitivity to groundwater and in-situ stress, various UGBs exhibit hysteretic nature and failure modes. To give a complete understanding on the internal causes, the emphasis on advanced comprehensive geological forecasting and overall reinforcement treatment is therefore of more practical significance. Compre- hensive evaluation of influential factors, identification of UGB, and measures of discontinuity dynamic controlling comprises the geoengineering condition evaluation and dynamic controlling method. In a case of a cut slope, the variations of UGBs and the impacts of key environmental factors are presented, where more severe construction-triggered geohazards emerged in construction stage than those predicted in design and field investigation stages. As a result, the weight ratios of different influential factors with respect to field investigation, design and construction are obtained.
基金funded by Jiangsu Overseas Research&Training Program for University Prominent Young and Middle-aged Teachers and Presidents
文摘Presentations are activities in which people show,describe,or explain something to a group of people.They are often used in American school classrooms.On the base of the author’s referring to literature,observing classes and co-teaching practice,presentations are suggested to be applied to EFL classrooms to help students improve their speaking levels and integrate their language skills efficiently.In point of ways of organizing,presentations can be divided into three types:controlled,guided and free ones.While in point of ways of applying,they can be divided into five types:interactive,role-plays,interview,note-taking,and discourse analysis ones.Thus different types of presentations should be adopted according to EFL students’different levels and different communication purposes.Topics relating to EFL students’study,life and interest are practical for presentations.Important aspects of presentations include:posture and presence,eye contact with the audience,volume and voice projection,rate of speech,use of audiovisual aids,vitality,adherence to the topic,keeping track of time,natural delivery,fluency and accuracy,the quantity of information presented,the way the topic was handled and how the questions are handled in the post-presentation session and so on.Presentation evaluations can be done by the teacher or together with student peers.
文摘The purpose of this study is focused on development of an online monitoring system for measuring and evaluating the cutting condition as the ID-blade saw is cutting a silicon ingot. First,the cutting experiments are carried out and the cutting signals during the blade slicing a six-inch ingot are measured by a 3-axes load sensor which is mounted on the top of the ingot. To evaluate the blade condition in slicing,a novel data processing method,combining the discrete Fourier transform(DFT) with the discrete Wavelet transform(DWT),is proposed in this paper for extracting the components due to the rotation of the blade and the cutting impedance. To validate the effect of the method,four ID-blades with three different types of the blade edge are used and discussed. The obtained results show that the component induced from the rotation and the component due to the blade slicing can be extracted efficiently by introduction of the proposed method. Furthermore,a simple online monitoring system,which consists of a 3-axes load sensor or acceleration sensor,DC cuts high-pass filter,and AD converter embedded microcomputer,is designed. The estimated cutting condition information obtained from the proposed monitoring system can be used as a feedback signal to the slicing machine for production of high quality wafer.
文摘This paper presents the ageing mechanism of fuse in nuclear power plant in detail. Metal Electromigration is identified as the dominant ageing mechanism. On this basis, the dominant status indicators, temperature and resistance of fuse were ensured, and current-temperature curve was proposed. The infrared thermal imaging technology was used to inspect the ageing condition and prove the current-temperature curve. Finally, the accelerated ageing testing was conducted abiding by the dominant ageing mechanism, and the lifetime was evaluated.
文摘The present development situation of transgenic crops and their effect on ecological environment are introduced in the paper.Some relevant strategies for their future and how to control the risks of ecological environment are presented.
基金the National Natural Science Foundation of China(Grant No.40973041)
文摘Based on the geochemical characteristics of oil-cracking gas and kerogen-cracking gas revealed by simu-lation experiments and the chemical composition of natural gases in actual gas reservoirs,two kinds of natural gases with different relationships between C_(2)/C_(3)and C_(1)/C_(2),C_(2)/C_(3)and C_(1)/C_(3),C_(2)/C_(3)and 100×C_(1)/(C_(1)-C5)were identified in the Tarim Basin,and proposed further by the authors.The relationship charts of C_(2)/C_(3)and C_(1)/C_(2),C_(2)/C_(3)and C_(1)/C_(3),C_(2)/C_(3)and 100×C_(1)/(C_(1)-C_(5))can be used to effectively distinguish oil-cracking gas from kerogen-cracking gas.Petro-leum geological analysis of the oil-cracking gas reservoirs showed that the distribution of oil-cracking gas is mostly related with deep-seated faults or faults with a large fault throw,and the burial depth of paleo-oil reservoir is rela-tively high;crude oil-cracking gas resources have been evaluated by using both forward and inversion methods.The plots of C_(2)/C_(3)vs.C_(1)/C_(2),C_(2)/C_(3)vs.C_(1)/C_(3),and C_(2)/C_(3)vs.100×C_(1)/(C_(1)-C_(5))were used to distinguish between oil-crack-ing gas and kerogen-cracking gas,and estimate the mixed ratios of the two kinds of natural gases in the main gas reservoirs of the platform area.
基金Funding for this study was received from the Deputyship for Research&Innovation,Ministry of Education in Saudi Arabia through the project number“IFPHI-021–135–2020”and King Abdulaziz University,DSR,Jeddah,Saudi Arabia.
文摘Increasing renewable energy targets globally has raised the requirement for the efficient and profitable operation of solar photovoltaic(PV)systems.In light of this requirement,this paper provides a path for evaluating the operating condition and improving the power output of the PV system in a grid integrated environment.To achieve this,different types of faults in grid-connected PV systems(GCPVs)and their impact on the energy loss associated with the electrical network are analyzed.A data-driven approach using neural networks(NNs)is proposed to achieve root cause analysis and localize the fault to the component level in the system.The localized fault condition is combined with a parallel operation of adaptive neurofuzzy inference units(ANFIUs)to develop a power mismatch-based control unit(PMCU)for improving the power output of the GCPV.To develop the proposed framework,a 10-kW single-phase GCPV is simulated for training the NN-based anomaly detection approach with 14 deviation signals.Further,the developed algorithm is combined with the PMCU implemented with the experimental setup of GCPV.The results identified 98.2%training accuracy and 43000 observations/sec prediction speed for the trained classifier,and improved power output with reduced voltage and current harmonics for the grid-connected PV operation.
