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Life cycle assessment as a prospective tool for sustainable agriculture and food planning at a local level
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作者 Andrea Lulovicova Stephane Bouissou 《Geography and Sustainability》 CSCD 2024年第2期251-264,共14页
Owing to the far-reaching environmental consequences of agriculture and food systems,such as their contribution to climate change,there is an urgent need to reduce their impact.International and national governments s... Owing to the far-reaching environmental consequences of agriculture and food systems,such as their contribution to climate change,there is an urgent need to reduce their impact.International and national governments set sustainability targets and implement corresponding measures.Nevertheless,critics of the globalized system claim that a territorial administrative scale is better suited to address sustainability issues.Yet,at the subnational level,local authorities rarely apply a systemic environmental assessment to enhance their action plans.This paper employs a territorial life cycle assessment methodology to improve local environmental agri-food planning.The objective is to identify significant direct and indirect environmental hotspots,their origins,and formulate effective mitigation strategies.The methodology is applied to the administrative department of Finistere,a strategic agricultural region in North-Western France.Multiple environmental criteria including climate change,fossil resource scarcity,toxicity,and land use are modeled.The findings reveal that the primary environmental hotspots of the studied local food system arise from indirect sources,such as livestock feed or diesel consumption.Livestock reduction and organic farming conversion emerge as the most environmentally efficient strategies,resulting in a 25%decrease in the climate change indicator.However,the overall modeled impact reduction is insufficient following national objectives and remains limited for the land use indicator.These results highlight the innovative application of life cycle assessment led at a local level,offering insights for the further advancement of systematic and prospective local agri-food assessment.Additionally,they provide guidance for local authorities to enhance the sustainability of planning strategies. 展开更多
关键词 Environmental analysis Territorial life cycle assessment Prospective scenario Agri-food planning Local food system
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Clinical validation of the early embryo viability assessment system: Analysis for the blastocyst morphology and pregnancy outcomes
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作者 Vu D Hop An M Cuong +3 位作者 Phi T T Anh Nguyen T L Huong Le Hoang Nguyen V Hanh 《Asian pacific Journal of Reproduction》 CAS 2024年第5期219-227,共9页
Objective:To determine the relationship between the early embryo viability assessment(EEVA)and blastocyst morphological parameters and pregnancy outcomes.Methods:This retrospective cohort study was conducted on 291 in... Objective:To determine the relationship between the early embryo viability assessment(EEVA)and blastocyst morphological parameters and pregnancy outcomes.Methods:This retrospective cohort study was conducted on 291 intracytoplasmic sperm injection cycles including 2522 embryos with indications of prolonging embryo culture to the blastocyst stage in the Genea embryo review incubator,and 511 single vitrified-warmed blastocyst transfer cycles from January 2020 to June 2023.The EEVA system produced an EEVA score from E1(best)to E5(worse)for the potential of blastocyst formation.Blastocyst morphology was evaluated.The association between the EEVA score and each type of blastocyst morphology,implantation rate,clinical pregnancy,and ongoing pregnancy were assessed using generalized estimating equations.Results:The inner cell mass A(ICM A),trophectoderm A(TE A),blastocoele expansion degree of 3,4,5,6,7 rates were higher with lower the EEVA score.The adjusted odd ratio(aOR)(E5 vs E1)was 0.3 for ICM A,0.174 for TE A and 0.210 for BL3,4,5,6,7(all P<0.001),suggesting a significant association between lower EEVA scores and improved embryo quality.The implantation,clinical pregnancy,and ongoing pregnancy rate were also higher with lower the EEVA score.The aOR of E5 vs E1 was 0.245 for implantation,0.185 for clinical pregnancy and 0.200 for ongoing pregnancy rate(P<0.001).Conclusions:There were associations between blastocyst morphology,pregnancy outcome and EEVA scores.The good blastocyst morphology and pregnancy outcomes are higher with lower the EEVA score. 展开更多
关键词 Automated embryo assessment BLASTOCYST Early embryo viability assessment Genea embryo review incubator MORPHOLOGY Pregnancy outcomes Timelapse
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Research on the Reform of the Process-Tracking Ideological and Political Assessment System in Applied Universities:Taking the Personal Finance Course as an Example 被引量:1
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作者 Jing Chen 《Journal of Contemporary Educational Research》 2024年第1期179-185,共7页
Using the Xi’an Mingde Institute of Technology students as the teaching object and the Personal Finance course as an example,we explore the reform of the ideological and political assessment system of process-trackin... Using the Xi’an Mingde Institute of Technology students as the teaching object and the Personal Finance course as an example,we explore the reform of the ideological and political assessment system of process-tracking courses in applied universities.The article analyzes the feasibility of applying the curriculum ideological and political assessment system in college courses and compares the traditional assessment system.It also proposes that applying curriculum ideological and political assessment to the college curriculum assessment system will help improve students’understanding of the“value guidance”in curriculum ideological and political education and enhance the teaching effect. 展开更多
关键词 Curriculum ideological and political education Teaching reform Curriculum assessment
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Stochastic programming based coordinated expansion planning of generation,transmission,demand side resources,and energy storage considering the DC transmission system
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作者 Liang Lu Mingkui Wei +4 位作者 Yuxuan Tao Qing Wang Yuxiao Yang Chuan He Haonan Zhang 《Global Energy Interconnection》 EI CSCD 2024年第1期25-37,共13页
With the increasing penetration of wind and solar energies,the accompanying uncertainty that propagates in the system places higher requirements on the expansion planning of power systems.A source-grid-load-storage co... With the increasing penetration of wind and solar energies,the accompanying uncertainty that propagates in the system places higher requirements on the expansion planning of power systems.A source-grid-load-storage coordinated expansion planning model based on stochastic programming was proposed to suppress the impact of wind and solar energy fluctuations.Multiple types of system components,including demand response service entities,converter stations,DC transmission systems,cascade hydropower stations,and other traditional components,have been extensively modeled.Moreover,energy storage systems are considered to improve the accommodation level of renewable energy and alleviate the influence of intermittence.Demand-response service entities from the load side are used to reduce and move the demand during peak load periods.The uncertainties in wind,solar energy,and loads were simulated using stochastic programming.Finally,the effectiveness of the proposed model is verified through numerical simulations. 展开更多
关键词 Hydro-wind-solar complementary Expansion planning Demand response Energy storage system Source-network-demand-storage coordination
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Opportunities to Improve the Quality of Environmental Reports and the Effectiveness of Environmental Impact Assessment: A Case of Electric Power Transmission Systems in Brazil
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作者 Vinícius Arthico Demori Marcelo Montaño 《Journal of Environmental Protection》 2024年第2期124-140,共17页
A good quality Environmental Impact Statement (EIS) is key for the effectiveness of Environmental Impact Assessment (EIA) processes and consequently to the acceptability of projects subject to EIA. The international l... A good quality Environmental Impact Statement (EIS) is key for the effectiveness of Environmental Impact Assessment (EIA) processes and consequently to the acceptability of projects subject to EIA. The international literature has contributed to the understanding of the essential aspects to be verified regarding the quality of EIS, offering a wide spectrum of good practice examples related to the content of the studies. Even so, there is a need for empirical studies that allow the identification of specific aspects related to the context of application of the EIS, which could lead to the identification of opportunities to improve both the quality of the reports and also the effectiveness of EIA. Therefore, the present paper is focused on the quality review of a number of EIS submitted to the Brazilian Federal Environmental Agency (Ibama) to instruct the assessment of electric power transmission systems. Based on the application of the EIS quality review package as proposed by Lee and Colley (1992), the outcomes reveal opportunities for improving the scope of EIA, analysis of alternatives, prediction of magnitude and the assessment of impact significance. Finally, the development and/or adaptation of a similar tool for the systematic review of the quality of EIA reports is recommended. 展开更多
关键词 Environmental Impact assessment EFFECTIVENESS Electric Energy Transmission systems
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A digital twins enabled underwater intelligent internet vehicle path planning system via reinforcement learning and edge computing
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作者 Jiachen Yang Meng Xi +2 位作者 Jiabao Wen Yang Li Houbing Herbert Song 《Digital Communications and Networks》 SCIE CSCD 2024年第2期282-291,共10页
The Autonomous Underwater Glider(AUG)is a kind of prevailing underwater intelligent internet vehicle and occupies a dominant position in industrial applications,in which path planning is an essential problem.Due to th... The Autonomous Underwater Glider(AUG)is a kind of prevailing underwater intelligent internet vehicle and occupies a dominant position in industrial applications,in which path planning is an essential problem.Due to the complexity and variability of the ocean,accurate environment modeling and flexible path planning algorithms are pivotal challenges.The traditional models mainly utilize mathematical functions,which are not complete and reliable.Most existing path planning algorithms depend on the environment and lack flexibility.To overcome these challenges,we propose a path planning system for underwater intelligent internet vehicles.It applies digital twins and sensor data to map the real ocean environment to a virtual digital space,which provides a comprehensive and reliable environment for path simulation.We design a value-based reinforcement learning path planning algorithm and explore the optimal network structure parameters.The path simulation is controlled by a closed-loop model integrated into the terminal vehicle through edge computing.The integration of state input enriches the learning of neural networks and helps to improve generalization and flexibility.The task-related reward function promotes the rapid convergence of the training.The experimental results prove that our reinforcement learning based path planning algorithm has great flexibility and can effectively adapt to a variety of different ocean conditions. 展开更多
关键词 Digital twins Reinforcement learning Edge computing Underwater intelligent internet vehicle Path planning
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A novel refined dynamic model of high-speed maglev train-bridge coupled system for random vibration and running safety assessment
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作者 MAO Jian-feng LI Dao-hang +3 位作者 YU Zhi-wu CAI Wen-feng GUO Wei ZHANG Guang-wen 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2532-2544,共13页
Running safety assessment and tracking irregularity parametric sensitivity analysis of high-speed maglev train-bridge system are of great concern,especially need perfect refinement models in which all properties can b... Running safety assessment and tracking irregularity parametric sensitivity analysis of high-speed maglev train-bridge system are of great concern,especially need perfect refinement models in which all properties can be well characterized based on various stochastic excitations.A three-dimensional refined spatial random vibration analysis model of high-speed maglev train-bridge coupled system is established in this paper,in which multi-source uncertainty excitation can be considered simultaneously,and the probability density evolution method(PDEM)is adopted to reveal the system-specific uncertainty dynamic characteristic.The motion equation of the maglev vehicle model is composed of multi-rigid bodies with a total 210-degrees of freedom for each vehicle,and a refined electromagnetic force-air gap model is used to account for the interaction and coupling effect between the moving train and track beam bridges,which are directly established by using finite element method.The model is proven to be applicable by comparing with Monte Carlo simulation.By applying the proposed stochastic framework to the high maglev line,the random dynamic responses of maglev vehicles running on the bridges are studied for running safety and stability assessment.Moreover,the effects of track irregularity wavelength range under different amplitude and running speeds on the coupled system are investigated.The results show that the augmentation of train speed will move backward the sensitive wavelength interval,and track irregularity amplitude influences the response remarkably in the sensitive interval. 展开更多
关键词 maglev train-bridge interaction electromagnetic force-air gap model stochastic dynamic analysis running safety assessment probability density evolution method
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Review: update on performance assessment and monitoring systems for ophthalmologists
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作者 Heather G.Mack 《Annals of Eye Science》 2024年第1期24-33,共10页
Performance assessment and monitoring systems are the process by which ophthalmologists demonstrate they are fit to continue practicing.Revalidation is the process by which licensed doctors are legally required to dem... Performance assessment and monitoring systems are the process by which ophthalmologists demonstrate they are fit to continue practicing.Revalidation is the process by which licensed doctors are legally required to demonstrate to medical regulators that they are up to date and fit to practice in order to maintain their medical license,and began in the United Kingdom(UK)in 2012 following well-publicized events.Recertification is a different process which began in North America and demonstrates doctors have maintained competence,without involvement of external stakeholders.Arguments for and against the concept of performance assessment are reviewed.Stakeholders in performance assessment,whether part of the process or not,are doctors themselves,peers and other health care providers,patients,hospitals and health systems,medical regulators,and health policy makers.Early models of performance assessment included portfolios,credit accumulation,and closed-book examinations.Models are in evolution with the value of formative rather than summative assessments,and the need for methods of assessing procedural competency increasingly recognized.Emerging methods of performance assessment of practicing ophthalmologists include use of performance indicators,simulation,and workplace-based assessments.Alternate methods of assuring the public by improved detection of outliers are discussed.Despite weak evidence supporting performance assessments in demonstrating continuing competency to practice,the process is gradually being accepted worldwide.Further research into optimum methods of performance assessment and monitoring processes is required,along with cost-benefit analysis. 展开更多
关键词 Performance assessment REVALIDATION RECERTIFICATION maintenance of competency relicensure
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Dilemmas and Optimization of Third-Party Assessment System in Chinese Fair Competition Review
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作者 Cui Xu Mingyu Hu 《Open Journal of Applied Sciences》 2024年第8期2039-2049,共11页
The current predominant self-review mechanism by policy-making bodies suffers from deficiencies such as insufficient motivations, limited review capabilities, and weak external supervision. Third-party assessment, cha... The current predominant self-review mechanism by policy-making bodies suffers from deficiencies such as insufficient motivations, limited review capabilities, and weak external supervision. Third-party assessment, characterized by independence and specialization, is designed to mitigate these shortcomings. However, the implementation of third-party assessment faces challenges too. This paper intends to improve the third-party assessment system and to realize the legislative purpose of the system. Based on social research, discussions and exchanges with relevant parties, and the existing research results, this paper analyzes the challenges and possible optimization measures for the third-party assessment. The challenges include repulsion from policy-making bodies, insufficient independence of assessment bodies, disparity of assessment quality, and limited application of assessment outcomes. Possible optimization measures include promoting fair competition culture, increasing the acceptance of third-party assessment from policy-making bodies, enhancing the quality of third-party assessment, clarifying the relationship between policy-making bodies and assessment bodies, ensuring the independence of third-party assessments, and promoting the application of assessment results. 展开更多
关键词 Fair Competition Review Self-Review Third-Party assessment DILEMMA Optimization
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Risk assessment of high-speed railway CTC system based on improved game theory and cloud model
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作者 Yanhao Sun Tao Zhang +2 位作者 Shuxin Ding Zhiming Yuan Shengliang Yang 《Railway Sciences》 2024年第3期388-410,共23页
Purpose-In order to solve the problem of inaccurate calculation of index weights,subjectivity and uncertainty of index assessment in the risk assessment process,this study aims to propose a scientific and reasonable c... Purpose-In order to solve the problem of inaccurate calculation of index weights,subjectivity and uncertainty of index assessment in the risk assessment process,this study aims to propose a scientific and reasonable centralized traffic control(CTC)system risk assessment method.Design/methodologylapproach-First,system-theoretic process analysis(STPA)is used to conduct risk analysis on the CTC system and constructs risk assessment indexes based on this analysis.Then,to enhance the accuracy of weight calculation,the fuzzy analytical hierarchy process(FAHP),fuzzy decision-making trial and evaluation laboratory(FDEMATEL)and entropy weight method are employed to calculate the subjective weight,relative weight and objective weight of each index.These three types of weights are combined using game theory to obtain the combined weight for each index.To reduce subjectivity and uncertainty in the assessment process,the backward cloud generator method is utilized to obtain the numerical character(NC)of the cloud model for each index.The NCs of the indexes are then weighted to derive the comprehensive cloud for risk assessment of the CTC system.This cloud model is used to obtain the CTC system's comprehensive risk assessment.The model's similarity measurement method gauges the likeness between the comprehensive risk assessment cloud and the risk standard cloud.Finally,this process yields the risk assessment results for the CTC system.Findings-The cloud model can handle the subjectivity and fuzziness in the risk assessment process well.The cloud model-based risk assessment method was applied to the CTC system risk assessment of a railway group and achieved good results.Originality/value-This study provides a cloud model-based method for risk assessment of CTC systems,which accurately calculates the weight of risk indexes and uses cloud models to reduce uncertainty and subjectivity in the assessment,achieving effective risk assessment of CTC systems.It can provide a reference and theoretical basis for risk management of the CTC system. 展开更多
关键词 High-speed railway Centralized traffic control Risk assessment Game theory Cloud model Paper type Research paper
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Seismic safety assessment with non-Gaussian random processes for train-bridge coupled systems
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作者 Zhao Han Gao Lei +4 位作者 Wei Biao Tan Jincheng Guo Peidong Jiang Lizhong Xiang Ping 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第1期241-260,共20页
Extensive high-speed railway(HSR)network resembled the intricate vascular system of the human body,crisscrossing mainlands.Seismic events,known for their unpredictability,pose a significant threat to both trains and b... Extensive high-speed railway(HSR)network resembled the intricate vascular system of the human body,crisscrossing mainlands.Seismic events,known for their unpredictability,pose a significant threat to both trains and bridges,given the HSR’s extended operational duration.Therefore,ensuring the running safety of train-bridge coupled(TBC)system,primarily composed of simply supported beam bridges,is paramount.Traditional methods like the Monte Carlo method fall short in analyzing this intricate system efficiently.Instead,efficient algorithm like the new point estimate method combined with moment expansion approximation(NPEM-MEA)is applied to study random responses of numerical simulation TBC systems.Validation of the NPEM-MEA’s feasibility is conducted using the Monte Carlo method.Comparative analysis confirms the accuracy and efficiency of the method,with a recommended truncation order of four to six for the NPEM-MEA.Additionally,the influences of seismic magnitude and epicentral distance are discussed based on the random dynamic responses in the TBC system.This methodology not only facilitates seismic safety assessments for TBC systems but also contributes to standard-setting for these systems under earthquake conditions. 展开更多
关键词 train-bridge coupled(TBC)system random vibration new point estimate method(NPEM) seismic safety assessment moment expansion approximation(MEA) non-Gaussian distributions
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Research on the Evaluation System of Community Daycare Center Planning and Implementation from the Perspective of Subject-Object Relationships
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作者 Tijin Gui 《Journal of Architectural Research and Development》 2024年第3期117-127,共11页
Through literature review,we found that evaluations of urban planning implementation often focus narrowly on either the subject(stakeholders)or the object(projects),while micro-level aspects such as site selection and... Through literature review,we found that evaluations of urban planning implementation often focus narrowly on either the subject(stakeholders)or the object(projects),while micro-level aspects such as site selection and construction are primarily considered within the context of planning implementation.There is insufficient research on the evaluation of implementation.Community daycare centers play a crucial role in the community home care model,yet there is relatively little research on their usage efficiency,satisfaction levels,and spatial evaluation of planning implementation.Based on the theoretical understanding of the human environment,including the subject,object,and their interactions,an evaluation system for the planning and implementation of community day care centers was constructed,incorporating subjective evaluation,objective evaluation,and comparative analysis. 展开更多
关键词 Subject-object relationship Daycare center planning implementation Evaluation system
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Surrogacy of bird species in systematic conservation planning and conservation assessments in Yunnan Province,China
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作者 ZHOU Jian YANG Fei-ling +4 位作者 ZHONG Zi-jie ZHANG Ji LENG Xian YE Jin WU Rui-dong 《Journal of Mountain Science》 SCIE CSCD 2022年第10期2861-2873,共13页
Bird diversity is often used as surrogates for other species diversity,but there is a limited understanding of the extent of this surrogate in identifying representative priority conservation areas(PCAs).We used Yunna... Bird diversity is often used as surrogates for other species diversity,but there is a limited understanding of the extent of this surrogate in identifying representative priority conservation areas(PCAs).We used Yunnan Province in China as a case to measure the surrogacy of birds in systematic conservation planning.Here,we collected distribution records of mammals,amphibians,reptiles,and birds from public databases and literature,and applied systematic conservation planning methods to identify PCAs.We targeted four taxonomic groups at conservation targets of 17%,31%,and 50%of the total study area,and used the Jaccard similarity index to evaluate the surrogate extent of bird PCAs for the other three groups.Then,we overlapped different portfolios of PCAs with six categories of protected areas(PAs)in Yunnan,calculated the protection rates,and evaluated the effect of sustainable-use PAs on improving the protection rate of strict Nature Reserves.The results showed that bird PCAs generally had the highest surrogacy for representing PCAs of the other three taxa.At the 50%conservation target,the Jaccard indices between birds and the other taxa reached about 0.50.Moreover,amphibian PCAs had a good surrogacy for conserving reptiles,with a Jaccard index of 0.30,0.44 and 0.51 at the 17%,31%and 50%conservation targets,respectively.The existing PA system had quite low coverages for PCAs of these four taxa,and the average protection rates were 22.97%,19.78%and 16.52%at the three levels of conservation targets,respectively.The sustainable-use PAs can greatly complement the strict Nature Reserves by achieving average increased PA coverages of 10.00%,9.20%and 7.90%at the three conservation targets.Our findings provide a basis for surrogate-based conservation planning for areas with insufficient biodiversity information. 展开更多
关键词 Biodiversity surrogates Priority conservation areas Protected areas systematic conservation planning Threatened species YUNNAN
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Vehicle Assessment Management,Monitoring and Planning System for Regional Road Authorities
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作者 David Freer 《Journal of Traffic and Transportation Engineering》 2023年第3期138-144,共7页
Resource energy projects present a number of challenges to road authorities who need to formulate a response that allows for the appropriate infrastructure upgrades to be planned,constructed and paid for.Too often the... Resource energy projects present a number of challenges to road authorities who need to formulate a response that allows for the appropriate infrastructure upgrades to be planned,constructed and paid for.Too often the road authority is overwhelmed by individual traffic reports from the proponents without having any reference to a system or process such as a network traffic model on which to test options and cumulative impacts.Yet to set up a functional traffic model will take time,is costly and will need some in-house capability to maintain.At the other end of the scale spread sheet style options are cumbersome to use and often out of date.This paper describes a system that allows the authority to effectively manage the transport task.The latest proposed vehicle movements can be displayed on an active GIS screen and referenced against agreed operational parameters.Various report outputs are also available upon demand.Such a system would assist state and local government authorities to manage the new development generated traffic in Qld. 展开更多
关键词 Vehicle assessment TRANSPORT traffic network GIS
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Monitoring and Assessment System of Agricultural Drought Based on GIS Technology 被引量:4
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作者 李卫宁 匡昭敏 +4 位作者 卢远 李莉 何立 罗永明 曾行吉 《Agricultural Science & Technology》 CAS 2011年第9期1350-1354,共5页
[Objective] The research aimed to simplify the operating process of agricultural drought monitoring and assessment product,and improve fine level of monitoring and assessment map.[Method] By comprehensively using GIS ... [Objective] The research aimed to simplify the operating process of agricultural drought monitoring and assessment product,and improve fine level of monitoring and assessment map.[Method] By comprehensively using GIS and mathematics,meteorology,management science,computer science,the monitoring and assessment of drought were as the core,the monitoring and assessment system of agricultural drought based on GIS technology was studied.[Result] The drought in Guangxi on November 4,2006 was monitored by using the system,and the actual situation was used to test.The result proved that the good monitoring effect was obtained.[Conclusion] The monitoring and assessment system of agricultural drought based on GIS realized the organic combination of GIS and professional monitoring,assessment model.The flexible HCI interface and visualization expression were provided.The monitoring and assessment function of agricultural drought was realized.It had the good practicality and advancement. 展开更多
关键词 Agricultural drought Monitoring and assessment system GIS Professional model
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Discussion and Application of Planning EIA Index System in the Industrial Development Region Based on Low Carbon Economy 被引量:1
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作者 熊鸿斌 王萍 +1 位作者 金潇 项芳 《Meteorological and Environmental Research》 CAS 2010年第12期86-90,共5页
Aimed at the low carbon economy and the characteristics of planning EIA in the industrial development region,the planning EIA index system which merged with the low carbon economy concept in the industrial development... Aimed at the low carbon economy and the characteristics of planning EIA in the industrial development region,the planning EIA index system which merged with the low carbon economy concept in the industrial development region was established.The construction planning of national eco-industrial park in Hefei High-tech Industrial Development Zone was comprehensively evaluated by using the gray correlation method.The evaluation results of considering and without considering the low carbon index were contrasted and were verified by using the improved entropy method.The results showed that the regional sustainable development index constantly rose,and the planning was reasonable.Moreover,the suggestions were also put forward to tackle the problems. 展开更多
关键词 planning EIA in the industrial development region Low carbon economy Evaluation index system China
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System reliability assessment based on Wiener process and competing failure analysis 被引量:3
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作者 苏春 张烨 《Journal of Southeast University(English Edition)》 EI CAS 2010年第4期554-557,共4页
Considering the dependence and competitive relation-ship between traumatic failure and degradation,the reliability assessment of products based on competing failure analysis is studied.The hazard rate of traumatic fai... Considering the dependence and competitive relation-ship between traumatic failure and degradation,the reliability assessment of products based on competing failure analysis is studied.The hazard rate of traumatic failure is regarded as a Weibull distribution of the degradation performance,and the Wiener process is used to describe the degradation process.The parameters are estimated with the maximum likelihood estimation(MLE)method.A reliability model based on competing failure analysis is proposed.A case study of the GaAs lasers is given to validate the effectiveness of the model and its solving method.The results indicate that if only the degradation failure is considered,the estimated result will be comparably optimistic.Meanwhile,the correlation between the degradation and traumatic failure has a great influence on the accuracy of reliability assessment. 展开更多
关键词 degradation data Wiener process competing failure reliability assessment
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Tactical planning and optimization of a milk run system of parts pickup for an engine manufacturer 被引量:1
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作者 伊俊敏 周晶 +1 位作者 高晓亮 施挺 《Journal of Southeast University(English Edition)》 EI CAS 2007年第S1期99-104,共6页
A real-life milk run system designing problem of an engine manufacturer adopted JIT(just-in-time)production is studied.In the process of milk run system planning and design,the supply base is identified and a supplier... A real-life milk run system designing problem of an engine manufacturer adopted JIT(just-in-time)production is studied.In the process of milk run system planning and design,the supply base is identified and a supplier site map is plotted for an arrangement of routes on which parts are periodically collected in a JIT manner from many scattered suppliers.With unit load designing,vehicle choosing and fleet sizing,pickup routing,vehicle assigning and scheduling problems are studied.Among these problems,a CVRP problem is identified and formulated as the key optimization in designing this milk run system,and it is solved through an optimization process.This tactical planning and optimization process gives a good solution to the real problem,and may shed light on the planning of similar systems. 展开更多
关键词 milk run vehicle routing problem JUST-IN-TIME system planning
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Ecological Planning for Urban Green Space System——A Case Study of Chongqing Economic and Technological Development Zone 被引量:1
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作者 阴磊 李国庆 《Agricultural Science & Technology》 CAS 2015年第12期2876-2880,共5页
Based on overview of development history and research advances of do- mestic and foreign urban green space system planning, this paper made clear rele- vant concepts of the urban green space system. Urban green space ... Based on overview of development history and research advances of do- mestic and foreign urban green space system planning, this paper made clear rele- vant concepts of the urban green space system. Urban green space system is a key region for protecting ecological resources. Taking Chongqing Economic and Technological Development Zone as an example, on the basis of in-depth survey, it made a systematic study on green space system planning combining current situa- tions of green space and regional spatial characteristics of Chongqing Economic and Technological Development Zone. It discussed how to restore and build urban green space system, protect ecological environment, and promote regional economic de- velopment and harmony between human and nature through design of ecological technologies and landscape in the ecological planning of urban green space system. 展开更多
关键词 Urban areas Green space system Ecological planning
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Assessment of landscape ecology of agricultural protection forest system at Beizang Town, Daxing County, Beijing
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作者 李春平 关文彬 +3 位作者 范秀珍 赵廷宁 陈建刚 孙保平 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第2期135-140,共6页
Based on theories of protective forests and landscape ecology, the reasonableness of structures and patterns of shelterbelt system at Beizang Town, Daxing County, Beijing were analyzed and assessed from the two scales... Based on theories of protective forests and landscape ecology, the reasonableness of structures and patterns of shelterbelt system at Beizang Town, Daxing County, Beijing were analyzed and assessed from the two scales of forest belts and networks, by integrating uses of field investigation, GIS and RS techniques. Results showed that the existent main belt (3-12 m in width) was too narrow, while the assistant belt (3-27.1 m in width) was too wide; the species composition of the existent shelterbelts was single, and the structures and patterns of the shelterbelt system were unreasonable. It is suggested that the structure of the main and the assistant belts should be changed, such as increasing the width of main belts, decreasing the width of assistant belt, and planting more mixed species, and the pattern with arbores in the middle and shrubs in the sides of belts could be taken into account. For the landscape structure of forest network after regenerating or reconstruction, the grid number of closed network should be 13 per km2 and the minimum number of belts should be 34 per km2. This study also testified that integrating GIS and remote technique with landscape ecology could provide an effective method for reasonable reconstruction of the structures and patterns of shelterbelts system. 展开更多
关键词 BEIJING SHELTERBELTS Shelterbelt structure Ecology landscape assessment
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