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Performance evaluation of quality monitor models in spot welding
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作者 张忠典 李冬青 王凯 《China Welding》 EI CAS 2005年第1期58-62,共5页
Performance of quality monitor models in spot welding determines the monitor precision directly, so it’s crucial to evaluate it. Previously, mean square error (MSE) is often used to evaluate performances of models, b... Performance of quality monitor models in spot welding determines the monitor precision directly, so it’s crucial to evaluate it. Previously, mean square error (MSE) is often used to evaluate performances of models, but it can only show the total errors of finite specimens of models, and cannot show whether the quality information inferred from models are accurate and reliable enough or not. For this reason, by means of measure error theory, a new way to evaluate the performances of models according to the error distributions is developed as follows: Only if correct and precise enough the error distribution of model is, the quality information inferred from model is accurate and reliable. 展开更多
关键词 spot welding quality monitor model performance evaluation
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On Krashen’s Monitor Model Theory
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作者 颜薇薇 《语言与文化研究》 2019年第1期86-90,共5页
Krashen’s Monitor Model Theory is held to be the most ambitious theory of SLA(second language acquisition). Through a detailed analysis, the focus of discussion is laid on the impact that the theory has made in L2(se... Krashen’s Monitor Model Theory is held to be the most ambitious theory of SLA(second language acquisition). Through a detailed analysis, the focus of discussion is laid on the impact that the theory has made in L2(second language) research and its innate restrictions that give rise to many disputes and controversy. 展开更多
关键词 KRASHEN monitor model SLA
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Contribution of the MERISE-Type Conceptual Data Model to the Construction of Monitoring and Evaluation Indicators of the Effectiveness of Training in Relation to the Needs of the Labor Market in the Republic of Congo
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作者 Roch Corneille Ngoubou Basile Guy Richard Bossoto Régis Babindamana 《Open Journal of Applied Sciences》 2024年第8期2187-2200,共14页
This study proposes the use of the MERISE conceptual data model to create indicators for monitoring and evaluating the effectiveness of vocational training in the Republic of Congo. The importance of MERISE for struct... This study proposes the use of the MERISE conceptual data model to create indicators for monitoring and evaluating the effectiveness of vocational training in the Republic of Congo. The importance of MERISE for structuring and analyzing data is underlined, as it enables the measurement of the adequacy between training and the needs of the labor market. The innovation of the study lies in the adaptation of the MERISE model to the local context, the development of innovative indicators, and the integration of a participatory approach including all relevant stakeholders. Contextual adaptation and local innovation: The study suggests adapting MERISE to the specific context of the Republic of Congo, considering the local particularities of the labor market. Development of innovative indicators and new measurement tools: It proposes creating indicators to assess skills matching and employer satisfaction, which are crucial for evaluating the effectiveness of vocational training. Participatory approach and inclusion of stakeholders: The study emphasizes actively involving training centers, employers, and recruitment agencies in the evaluation process. This participatory approach ensures that the perspectives of all stakeholders are considered, leading to more relevant and practical outcomes. Using the MERISE model allows for: • Rigorous data structuring, organization, and standardization: Clearly defining entities and relationships facilitates data organization and standardization, crucial for effective data analysis. • Facilitation of monitoring, analysis, and relevant indicators: Developing both quantitative and qualitative indicators helps measure the effectiveness of training in relation to the labor market, allowing for a comprehensive evaluation. • Improved communication and common language: By providing a common language for different stakeholders, MERISE enhances communication and collaboration, ensuring that all parties have a shared understanding. The study’s approach and contribution to existing research lie in: • Structured theoretical and practical framework and holistic approach: The study offers a structured framework for data collection and analysis, covering both quantitative and qualitative aspects, thus providing a comprehensive view of the training system. • Reproducible methodology and international comparison: The proposed methodology can be replicated in other contexts, facilitating international comparison and the adoption of best practices. • Extension of knowledge and new perspective: By integrating a participatory approach and developing indicators adapted to local needs, the study extends existing research and offers new perspectives on vocational training evaluation. 展开更多
关键词 MERISE Conceptual Data model (MCD) monitoring Indicators Evaluation of Training Effectiveness Training-Employment Adequacy Labor Market Information Systems Analysis Adjustment of Training Programs EMPLOYABILITY Professional Skills
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Monitoring models for base flow effect and daily variation of dam seepage elements considering time lag effect 被引量:14
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作者 Shao-wei Wang Ying-li Xu +1 位作者 Chong-shi Gu Teng-fei Bao 《Water Science and Engineering》 EI CAS CSCD 2018年第4期344-354,共11页
Affected by external environmental factors and evolution of dam performance, dam seepage behavior shows nonlinear time-varying characteristics. In this study, to predict and evaluate the long-term development trend an... Affected by external environmental factors and evolution of dam performance, dam seepage behavior shows nonlinear time-varying characteristics. In this study, to predict and evaluate the long-term development trend and short-term fluctuation of the dam seepage behavior, two monitoring models were developed, one for the base flow effect and one for daily variation of dam seepage elements. In the first model, to avoid the influence of the time lag effect on the evaluation of seepage variation with the time effect component of seepage elements, the base values of the seepage element and the reservoir water level were extracted using the wavelet multi-resolution analysis method, and the time effect component was separated by the established base flow effect monitoring model. For the development of the daily variation monitoring model for dam seepage elements, all the previous factors, of which the measured time series prior to the dam seepage element monitoring time may have certain influence on the monitored results, were considered. Those factors that were positively correlated with the analyzed seepage element were initially considered to be the support vector machine(SVM) model input factors, and then the SVM kernel function-based sensitivity analysis was performed to optimize the input factor set and establish the optimized daily variation SVM model. The efficiency and rationality of the two models were verified by case studies of the water level of two piezometric tubes buried under the slope of a concrete gravity dam.Sensitivity analysis of the optimized SVM model shows that the influences of the daily variation of the upstream reservoir water level and rainfall on the daily variation of piezometric tube water level are processes subject to normal distribution. 展开更多
关键词 Dam seepage monitoring model Time lag effect Support vector machine(SVM) Sensitivity analysis Base flow Daily variation Piezometric tube water level
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Seepage safety monitoring model for an earth rock dam under influence of high-impact typhoons based on particle swarm optimization algorithm 被引量:8
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作者 Yan Xiang Shu-yan Fu +2 位作者 Kai Zhu Hui Yuan Zhi-yuan Fang 《Water Science and Engineering》 EI CAS CSCD 2017年第1期70-77,共8页
Extreme hydrological events induced by typhoons in reservoir areas have presented severe challenges to the safe operation of hydraulic structures. Based on analysis of the seepage characteristics of an earth rock dam,... Extreme hydrological events induced by typhoons in reservoir areas have presented severe challenges to the safe operation of hydraulic structures. Based on analysis of the seepage characteristics of an earth rock dam, a novel seepage safety monitoring model was constructed in this study. The nonlinear influence processes of the antecedent reservoir water level and rainfall were assumed to follow normal distributions. The particle swarm optimization (PSO) algorithm was used to optimize the model parameters so as to raise the fitting accuracy. In addition, a mutation factor was introduced to simulate the sudden increase in the piezometric level induced by short-duration heavy rainfall and the possible historical extreme reservoir water level during a typhoon. In order to verify the efficacy of this model, the earth rock dam of the Siminghu Reservoir was used as an example. The piezometric level at the SW1-2 measuring point during Typhoon Fitow in 2013 was fitted with the present model, and a corresponding theoretical expression was established. Comparison of fitting results of the piezometric level obtained from the present statistical model and traditional statistical model with monitored values during the typhoon shows that the present model has a higher fitting accuracy and can simulate the uprush feature of the seepage pressure during the typhoon perfectly. 展开更多
关键词 monitoring model Particle swarm optimization algorithm Earth rock dam Lagging effect TYPHOON Seepage pressure Mutation factor Piezometric level
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Effects of modeling means on properties of monitoring models of spot welding quality 被引量:2
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作者 张忠典 李冬青 +1 位作者 赵洪运 于燕 《China Welding》 EI CAS 2002年第2期119-123,共5页
Analyzing and modeling the relation between monitoring information during welding and quality information of the joints is the foundation of monitoring resistance spot welding quality. According to the means of modeli... Analyzing and modeling the relation between monitoring information during welding and quality information of the joints is the foundation of monitoring resistance spot welding quality. According to the means of modeling, the known models can be divided into three large categories: single linear regression models, multiple linear regression models and multiple non linear models. By modeling the relations between dynamic resistance information and welding quality parameters with different means, this paper analyzes effects of modeling means on performances of monitoring models of resistance spot welding quality. From the test results, the following conclusions can be drawn: By comparison with two other kinds of models, artificial neural network (ANN) model can describe non linear and high coupling relationship between monitoring information and quality information more reasonably, improve performance of monitoring model remarkably, and make the estimated values of welding quality parameters more accurate and reliable. 展开更多
关键词 spot welding quality monitoring model regression analysis artificial neural networks
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Evaluation of health benefit using Ben MAP-CE with an integrated scheme of model and monitor data during Guangzhou Asian Games 被引量:15
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作者 Dian Ding Yun Zhu +7 位作者 Carey Jang Che-Jen Lin Shuxiao Wang Joshua Fu Jian Gao Shuang Deng Junping Xie Xuezhen Qiu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2016年第4期9-18,共10页
Guangzhou is the capital and largest city(land area:7287 km2)of Guangdong province in South China.The air quality in Guangzhou typically worsens in November due to unfavorable meteorological conditions for pollutan... Guangzhou is the capital and largest city(land area:7287 km2)of Guangdong province in South China.The air quality in Guangzhou typically worsens in November due to unfavorable meteorological conditions for pollutant dispersion.During the Guangzhou Asian Games in November 2010,the Guangzhou government carried out a number of emission control measures that significantly improved the air quality.In this paper,we estimated the acute health outcome changes related to the air quality improvement during the 2010 Guangzhou Asian Games using a next-generation,fully-integrated assessment system for air quality and health benefits.This advanced system generates air quality data by fusing model and monitoring data instead of using monitoring data alone,which provides more reliable results.The air quality estimates retain the spatial distribution of model results while calibrating the value with observations.The results show that the mean PM2.5concentration in November 2010 decreased by 3.5μg/m^3 compared to that in 2009 due to the emission control measures.From the analysis,we estimate that the air quality improvement avoided 106 premature deaths,1869 cases of hospital admission,and 20,026 cases of outpatient visits.The overall cost benefit of the improved air quality is estimated to be 165 million CNY,with the avoided premature death contributing 90%of this figure.The research demonstrates that Ben MAP-CE is capable of assessing the health and cost benefits of air pollution control for sound policy making. 展开更多
关键词 Air quality Health benefit PM2.5 Ben MAP-CE Data fusion model and monitor data
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Study and application of monitoring plane displacement of a similarity model based on time-series images 被引量:5
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作者 Xu Jiankun Wang Enyuan +1 位作者 Li Zhonghui Wang Chao 《Mining Science and Technology》 EI CAS 2011年第4期501-505,共5页
In order to compensate for the deficiency of present methods of monitoring plane displacement in similarity model tests,such as inadequate real-time monitoring and more manual intervention,an effective monitoring meth... In order to compensate for the deficiency of present methods of monitoring plane displacement in similarity model tests,such as inadequate real-time monitoring and more manual intervention,an effective monitoring method was proposed in this study,and the major steps of the monitoring method include:firstly,time-series images of the similarity model in the test were obtained by a camera,and secondly,measuring points marked as artificial targets were automatically tracked and recognized from time-series images.Finally,the real-time plane displacement field was calculated by the fixed magnification between objects and images under the specific conditions.And then the application device of the method was designed and tested.At the same time,a sub-pixel location method and a distortion error model were used to improve the measuring accuracy.The results indicate that this method may record the entire test,especially the detailed non-uniform deformation and sudden deformation.Compared with traditional methods this method has a number of advantages,such as greater measurement accuracy and reliability,less manual intervention,higher automation,strong practical properties,much more measurement information and so on. 展开更多
关键词 Plane displacement monitoring Similarity model test Time-series images Displacement measurement
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Underground ground control monitoring and interpretation,and numerical modeling, and shield capacity design 被引量:7
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作者 Syd S.Peng Jingyi Cheng +1 位作者 Feng Du Yuting Xue 《International Journal of Mining Science and Technology》 EI CSCD 2019年第1期79-85,共7页
Mine or longwall panel layout is a 3D structure with highly non-uniform stress distribution. Recognition of such fact will facilitate underground problem identification/investigation and solving by numerical modeling ... Mine or longwall panel layout is a 3D structure with highly non-uniform stress distribution. Recognition of such fact will facilitate underground problem identification/investigation and solving by numerical modeling through proper model construction. Due to its versatility, numerical modeling is the most popular method for ground control design and problem solving. However numerical modeling results require highly experienced professionals to interpret its validity/applicability to actual mining operations due to complicated mining and geological conditions. Underground ground control monitoring is routinely performed to predict roof behavior such as weighting and weighting interval without matching observation of face mining condition while the mining pressures are being monitored, resulting in unrealistic interpretation of the obtained data on mining pressure. The importance of ground control pressure monitoring and simultaneous observation of mining and geological conditions is illustrated by an example of shield leg pressure monitoring and interpretation in an U.S. longwall coal mine: it was found that the roof strata act like a plate, not an individual block of the size of a shield dimension, as commonly assumed by all researchers and shield capacity is not a fixed property for a longwall panel or a mine or a coal seam. A new mechanism on the interaction between shield's hydraulic leg pressure and roof strata for shield loading is proposed. 展开更多
关键词 MINE structure Ground control monitorING Numerical modeling SHIELD LEG pressure Periodic weighting
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Damage-Monitoring Forward Equivalent-model Construction of Rosette Eddy Current Sensors 被引量:2
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作者 DING Hua HE Yuting JIAO Shenbo DU Jingqiang 《中国电机工程学报》 EI CSCD 北大核心 2013年第9期I0022-I0022,共1页
结构损伤监测对于保证结构安全是极其重要的。针对金属螺栓连接结构中螺栓孔位置处的裂纹损伤定量监测需求,在Goldfine等人的基础之上,该文提出一种花萼状涡流传感器,构建了传感器损伤监测正向等效模型并通过搭建实验装置验证损伤监测... 结构损伤监测对于保证结构安全是极其重要的。针对金属螺栓连接结构中螺栓孔位置处的裂纹损伤定量监测需求,在Goldfine等人的基础之上,该文提出一种花萼状涡流传感器,构建了传感器损伤监测正向等效模型并通过搭建实验装置验证损伤监测正向等效模型准确性并进行误差分析。相对于传统的多层导电结构谐波涡流场的积分/级数解析模型,构建的损伤监测正向等效模型考虑了在高频激励下导线电流密度分布的集肤效应,并可用于互感式涡流传感器建模。实验结果表明:对测量结果经空气标定后,传感器贴于2A12-T4标准试件表面时的模型计算结果和实验结果较为吻合,第1、2和3感应通道的幅值比量模型计算结果误差随频率变化均在10%以内,第4感应通道的幅值比量模型计算结果误差随频率变化在15%以内。 展开更多
关键词 电涡流传感器 模型建设 损伤监测 等效 结构健康监测 使能技术 平面线圈 电导率测量
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Parsimonious Model for Blood Glucose Level Monitoring in Type 2 Diabetes patients 被引量:2
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作者 ZHAO Fang MA Yan Fen +3 位作者 WEN Jing Xiao DU Yan Fang LI Chun Lin LI Guang Wei 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2014年第7期559-563,共5页
To establish the parsimonious model for blood glucose monitoring in patients with type 2 diabetes receiving oral hypoglycemic agent treatment. One hundred and fifty-nine adult Chinese type 2 diabetes patients were ran... To establish the parsimonious model for blood glucose monitoring in patients with type 2 diabetes receiving oral hypoglycemic agent treatment. One hundred and fifty-nine adult Chinese type 2 diabetes patients were randomized to receive rapid-acting or sustained-release gliclazide therapy for 12 weeks. 展开更多
关键词 SMBG HBALC Parsimonious model for Blood Glucose Level monitoring in Type 2 Diabetes patients
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Analog-experiment analysis of ash-deposition monitoring model of boiler economizers in power plants
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作者 程伟良 夏国栋 徐寿臣 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2005年第6期680-683,共4页
Ash deposition is a form of particulate fouling, and appears usually in boiler economizers. The ash deposition increases capital expenditure, energy input and maintenance costs. An analog experiment for monitoring ash... Ash deposition is a form of particulate fouling, and appears usually in boiler economizers. The ash deposition increases capital expenditure, energy input and maintenance costs. An analog experiment for monitoring ash deposition was performed from the analogous objective of a 410 t/h boiler economizer to verify the rationality and reliability of the ash-deposition-monitoring model presented in order to increase the security and economy in economizer running. The analog experiment platform is a tube-shell exchanger that conforms well to the conditions of a self-modeling area. The analog flue gas in the shell side is the heated air mixed with ash, and in the tube side the fluid is water heated by the flue gas. The fluid state in the water side and the flue gas side follows the second self-modeling area. A 4-factor-3-level orthogonal table was used to schedule 9 operation conditions of orthogonal experiment, with the 4 factors being heat power, flue gas velocity, ashes grain diameter and adding ashes quantity while the three levels are different values due to different position classes in every factor. The ash deposition thermal resistances is calculated by the model with the measure parameters of temperature and pressure drop. It shows that the values of the ash deposition thermal resistances gradually increase up to a stable state. And the experimental results are reliable by F testing method at α= 0.001. Therefore, the model can be applied in online monitoring of ash deposition in a boiler economizers in power plants and provides scientific decision on ash deposition prediction and sootblowing. 展开更多
关键词 thermal power engineering monitoring model ash deposition orthogonal experiment boiler economizer tube-shell exchanger
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IGCP 641 Project:Mechanisms,Monitoring and Modeling Earth Fissure Generation and Fault Activation due to Subsurface Fluid Exploitation
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作者 YE Shujun Dora CARREoN-FREYRE +1 位作者 Pietro TEATINI Devin GALLOWAY 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第S01期165-168,共4页
Ground ruptures(fractures,earth fissures and reactivation of pre-existing surface faults)caused by extraction of fluids from the subsurface have been observed in hundreds of sedimentary basins worldwide,mainly in semi... Ground ruptures(fractures,earth fissures and reactivation of pre-existing surface faults)caused by extraction of fluids from the subsurface have been observed in hundreds of sedimentary basins worldwide,mainly in semiarid to arid areas of the USA,Mexico,China,India,Libya,Iran,and Saudi Arabia. 展开更多
关键词 MECHANISMS monitoring modeling EARTH FISSURE SUBSURFACE FLUID EXPLOITATION
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Assessing citizen science opportunities in forest monitoring using probabilistic topic modelling 被引量:1
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作者 Stefan Daume Matthias Albert Klaus von Gadow 《Forestry Studies in China》 CAS 2014年第2期93-104,共12页
Background: With mounting global environmental, social and economic pressures the resilience and stability of forests and thus the provisioning of vital ecosystem services is increasingly threatened. Intensified moni... Background: With mounting global environmental, social and economic pressures the resilience and stability of forests and thus the provisioning of vital ecosystem services is increasingly threatened. Intensified monitoring can help to detect ecological threats and changes earlier, but monitoring resources are limited. Participatory forest monitoring with the help of "citizen scientists" can provide additional resources for forest monitoring and at the same time help to communicate with stakeholders and the general public. Examples for citizen science projects in the forestry domain can be found but a solid, applicable larger framework to utilise public participation in the area of forest monitoring seems to be lacking. We propose that a better understanding of shared and related topics in citizen science and forest monitoring might be a first step towards such a framework. Methods: We conduct a systematic meta-analysis of 1015 publication abstracts addressing "forest monitoring" and "citizen science" in order to explore the combined topical landscape of these subjects. We employ 'topic modelling an unsupervised probabilistic machine learning method, to identify latent shared topics in the analysed publications. Results: We find that large shared topics exist, but that these are primarily topics that would be expected in scientific publications in general. Common domain-specific topics are under-represented and indicate a topical separation of the two document sets on "forest monitoring" and "citizen science" and thus the represented domains. While topic modelling as a method proves to be a scalable and useful analytical tool, we propose that our approach could deliver even more useful data if a larger document set and full-text publications would be available for analysis. Conclusions: We propose that these results, together with the observation of non-shared but related topics, point at under-utilised opportunities for public participation in forest monitoring. Citizen science could be applied as a versatile tool in forest ecosystems monitoring, complementing traditional forest monitoring programmes, assisting early threat recognition and helping to connect forest management with the general public. We conclude that our presented approach should be pursued further as it may aid the understanding and setup of citizen science efforts in the forest monitoring domain. 展开更多
关键词 Forest monitoring Citizen science Participatory forest monitoring Probabilistic topic modelling Text analysis
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Design and Application of Integrated Monitoring Model for Provincial Meteorological Observation Data Transmission
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作者 Yonghua Zhang Xiaoyu Chen +3 位作者 Shuoben Bi Ping Shen Zhenlang Ao Zhongying Hu 《Journal of Geoscience and Environment Protection》 2019年第5期94-104,共11页
With the development of meteorological services, there are more and more types of real-time observation data, and the timeliness requirements are getting higher and higher. The monitoring methods of existing meteorolo... With the development of meteorological services, there are more and more types of real-time observation data, and the timeliness requirements are getting higher and higher. The monitoring methods of existing meteorological observation data transmission can no longer meet the needs. This paper proposes a new monitoring model, namely the “integrated monitoring model” for provincial meteorological observation data transmission. The model can complete the whole network monitoring of meteorological observation data transmission process. Based on this model, the integrated monitoring system for meteorological observation data transmission in Guangdong Province is developed. The system uses Java as the programming language, and integrates J2EE, Hibernate, Quartz, Snmp4j and Slf4j frameworks, and uses Oracle database as the data storage carrier, following the MVC specification and agile development concept. The system development uses four key technologies, including simple network management protocol, network connectivity detection technology, remote host management technology and thread pool technology. The integrated monitoring system has been put into business application. As a highlight of Guangdong’s meteorological modernization, it has played an active role in many major meteorological services. 展开更多
关键词 PROVINCIAL Level METEOROLOGICAL OBSERVATION Data Transmission INTEGRATED monitoring model DESIGN SNMP
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The Application of Remote Sensing Monitoring Method and Groundwater Model for Water Rights Management in Haihe River basin
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作者 Lijuan Xue~1,Xinjun Zhu~(1,2),Songqiu Bo~3,Jianxin Li~3,Wei Li~3,Wei Yang~1 1.Tianjin Lonwin Network Science & Technology Development Co.Ltd,Tianjin 300181,China. 2.Key Laboratory of Water Cycle and Related land Surface Processes,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Science,Beijing 100101,China 3.Haihe River Water Conservancy Commission of Ministry of Water Resources,Tianjin 300170,China 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期26-26,共1页
Groundwater is an important water resource in Haihe River basin,North China.The number of aquifers that appear to be declining under conditions of groundwater overdraft is increasing.To effectively manage the water re... Groundwater is an important water resource in Haihe River basin,North China.The number of aquifers that appear to be declining under conditions of groundwater overdraft is increasing.To effectively manage the water resources,there is a strong scientific need to analyze the net use of this important water resource and to quantify the water rights allocation for improved understanding of the future water 展开更多
关键词 REMOTE sensing monitoring GROUNDWATER model water RIGHTS net GROUNDWATER use Haihe RIVER BASIN
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Qualitative Models for the Landscape Development Monitoring
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作者 Jiri Bila Ivo Bukovsky 《通讯和计算机(中英文版)》 2012年第6期721-728,共8页
关键词 定性模型 园林发展 监测 生态系统模型 深港西部通道 体系结构 数据模型 序列模型
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A Data-Driven Simulation Model for China Haze Monitor and Governance
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作者 Xiaoyan Lu Hong Chen +1 位作者 Miao Wang Zhengying Cai 《World Journal of Engineering and Technology》 2016年第2期374-381,共8页
Recently, the China haze becomes more and more serious, but it is very difficult to model and control it. Here, a data-driven model is introduced for the simulation and monitoring of China haze. First, a multi-dimensi... Recently, the China haze becomes more and more serious, but it is very difficult to model and control it. Here, a data-driven model is introduced for the simulation and monitoring of China haze. First, a multi-dimensional evaluation system is built to evaluate the government performance of China haze. Second, a data-driven model is employed to reveal the operation mechanism of China’s haze and is described as a multi input and multi output system. Third, a prototype system is set up to verify the proposed scheme, and the result provides us with a graphical tool to monitor different haze control strategies. 展开更多
关键词 DATA-DRIVEN Haze monitor MIMO Simulation model
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基于应变传递模型的形状记忆合金混凝土结构裂缝损伤监测与修复研究 被引量:2
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作者 韩旭 邢晓涛 +2 位作者 刘兵飞 梅波 李鹏飞 《工程力学》 北大核心 2025年第S1期251-259,267,共10页
由于形状记忆合金(Shape Memory Alloy, SMA)材料具有形状记忆效应、伪弹性、高强度比、耐腐蚀、耐磨损等工程优势,SMA复合结构引起了智能结构领域的广泛关注。利用SMA材料的优良力学特性,其与混凝土材料结合将会对混凝土裂缝的萌生产... 由于形状记忆合金(Shape Memory Alloy, SMA)材料具有形状记忆效应、伪弹性、高强度比、耐腐蚀、耐磨损等工程优势,SMA复合结构引起了智能结构领域的广泛关注。利用SMA材料的优良力学特性,其与混凝土材料结合将会对混凝土裂缝的萌生产生抑制效果,并通过形状记忆效应对混凝土内部裂缝进行修复。该文将SMA内置于混凝土材料中,制成复合式SMA混凝土结构,开展了复合式SMA混凝土结构的裂缝损伤监测与修复行为研究。基于应变传递理论与SMA本构模型,建立了SMA混凝土结构裂缝损伤监测与修复解析模型,并和试验进行了对比。结果表明:马氏体含量以及埋入长度越大,应变传递系数越大;混凝土裂缝损伤应变与SMA电阻相对变化总体呈单调递增关系;初始状态下为马氏体的SMA,对混凝土裂缝损伤的修复行为发生于SMA奥氏体开始相变临界温度之后,且随着温度升高,裂缝修复效果逐渐增强。 展开更多
关键词 形状记忆合金 应变传递 裂缝损伤监测 修复模型 参数分析
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Current Model Analysis of South China Sea Based on Empirical Orthogonal Function(EOF) Decomposition and Prototype Monitoring Data 被引量:4
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作者 WU Wenhua LIU Ming +1 位作者 YU Siyuan WANG Yanlin 《Journal of Ocean University of China》 SCIE CAS CSCD 2019年第2期305-316,共12页
Environmental load is the primary factor in the design of offshore engineering structures and ocean current is the principal environmental load that causes underwater structural failure. In computational analysis, the... Environmental load is the primary factor in the design of offshore engineering structures and ocean current is the principal environmental load that causes underwater structural failure. In computational analysis, the calculation of current load is mainly based on the current profile. The current profile model, which is based on a structural failure criterion, is conducive to decreasing the uncertainty of the current load. In this study, we used prototype monitoring data and the empirical orthogonal function(EOF) method to investigate the current profile in the South China Sea and its correlation with the design of underwater structural strength and the dynamic design of fatigue. The underwater structural strength design takes into account the size of the structure and the service water depth. We propose profiles for the overall and local designs using the inverse first-order reliability method(IFORM). We extracted the characteristic profile current(CPC) of the monitored sea area to solve dynamic design problems such as vortex-induced vibration(VIV). We used random sampling to verify the feasibility of using the EOF method to calculate the CPC from the current data and identified the main problems associated with using the CPC, which deserve close attention in VIV design. Our research conclusions provide direct references for determining current load in this sea area. This analysis method can also be used in the analysis of other sea areas or field variables. 展开更多
关键词 CURRENT PROFILE model failure criteria PROTOTYPE monitoring inverse FIRST-ORDER reliability method(IFORM) Characteristic PROFILE current(CPC)
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