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Virtual electromagnetic environment modeling based data augmentation for drone signal identification 被引量:1
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作者 Hanshuo Zhang Tao Li +1 位作者 Yongzhao Li Zhijin Wen 《Journal of Information and Intelligence》 2023年第4期308-320,共13页
Radio frequency(RF)-based drone identification technologies have the advantages of long effective distances and low environmental dependence,which has become indispensable for drone surveillance systems.However,since ... Radio frequency(RF)-based drone identification technologies have the advantages of long effective distances and low environmental dependence,which has become indispensable for drone surveillance systems.However,since drones operate in unlicensed frequency bands,a large number of co-frequency devices exist in these bands,which brings a great challenge to traditional signal identification methods.Deep learning techniques provide a new approach to complete endto-end signal identification by directly learning the distribution of RF data.In such scenarios,due to the complexity and high dynamics of the electromagnetic environments,a massive amount of data that can reflect the various propagation conditions of drone signals is necessary for a robust neural network(NN)for identifying drones.In reality,signal acquisition and labeling that meet the above requirements are too costly to implement.Therefore,we propose a virtual electromagnetic environment modeling based data augmentation(DA)method to improve the diversity of drone signal data.The DA method focuses on simulating the spectrograms of drone signals transmitted in real-world environments and randomly generates extra training data in each training epoch.Furthermore,considering the limited processing capability of RF receivers,we modify the original YOLOv5s model to a more lightweight version.Without losing the identification performance,more hardware-friendly designs are applied and the number of parameters decreases about 10-fold.For performance evaluation,we utilized a universal software radio peripheral(USRP)X310 platform to collect RF signals of four drones in an anechoic chamber and a practical wireless scenario.Experiment results reveal that the NN trained with augmented data performs as well as that trained with practical data in the complex electromagnetic environment. 展开更多
关键词 Drone signal identification Data augmentation Virtual electromagnetic environment modeling You Only Look Once SPECTROGRAM
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Ranking environmental projects model based on multicriteria decision-making and the weight sensitivity analysis 被引量:5
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作者 Jiang Yan Tian Dagang Pan Yue 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2007年第3期534-539,共6页
With the fast growth of Chinese economic, more and more capital will be invested in environmental projects. How to select the environmental investment projects (alternatives) for obtaining the best environmental qua... With the fast growth of Chinese economic, more and more capital will be invested in environmental projects. How to select the environmental investment projects (alternatives) for obtaining the best environmental quality and economic benefits is an important problem for the decision makers. The purpose of this paper is to develop a decision-making model to rank a finite number of alternatives with several and sometimes conflicting criteria. A model for ranking the projects of municipal sewage treatment plants is proposed by using exports' information and the data of the real projects. And, the ranking result is given based on the PROMETHEE method. Furthermore, by means of the concept of the weight stability intervals (WSI), the sensitivity of the ranking results to the size of criteria values and the change of weights value of criteria are discussed. The result shows that some criteria, such as “proportion of benefit to project cost”, will influence the ranking result of alternatives very strong while others not. The influence are not only from the value of criterion but also from the changing the weight of criterion. So, some criteria such as “proportion of benefit to project cost” are key critera for ranking the projects. Decision makers must be cautious to them. 展开更多
关键词 multicriteria decision-making ranking environmental projects model PROMETHEE method sensitivity analysis weight stability intervals.
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Profiles and Source Apportionment of Nonmethane Volatile Organic Compounds in Winter and Summer in Xi’an, China, based on the Hybrid Environmental Receptor Model 被引量:4
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作者 Jian SUN Zhenxing SHEN +8 位作者 Yue ZHANG Wenting DAI Kun HE Hongmei XU Zhou ZHANG Long CUI Xuxiang LI Yu HUANG Junji CAO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2021年第1期116-131,共16页
Summer and winter campaigns for the chemical compositions and sources of nonmethane hydrocarbons(NMHCs)and oxygenated volatile organic compounds(OVOCs)were conducted in Xi’an.Data from 57 photochemical assessment mon... Summer and winter campaigns for the chemical compositions and sources of nonmethane hydrocarbons(NMHCs)and oxygenated volatile organic compounds(OVOCs)were conducted in Xi’an.Data from 57 photochemical assessment monitoring stations for NMHCs and 20 OVOC species were analyzed.Significant seasonal differences were noted for total VOC(TVOC,NMHCs and OVOCs)concentrations and compositions.The campaign-average TVOC concentrations in winter(85.3±60.6 ppbv)were almost twice those in summer(47.2±31.6 ppbv).Alkanes and OVOCs were the most abundant category in winter and summer,respectively.NMHCs,but not OVOCs,had significantly higher levels on weekends than on weekdays.Total ozone formation potential was higher in summer than in winter(by 50%)because of the high concentrations of alkenes(particularly isoprene),high temperature,and high solar radiation levels in summer.The Hybrid Environmental Receptor Model(HERM)was used to conduct source apportionment for atmospheric TVOCs in winter and summer,with excellent accuracy.HERM demonstrated its suitability in a situation where only partial source profile data were available.The HERM results indicated significantly different seasonal source contributions to TVOCs in Xi’an.In particular,coal and biomass burning had contributions greater than half in winter(53.4%),whereas traffic sources were prevalent in summer(53.1%).This study’s results highlight the need for targeted and adjustable VOC control measures that account for seasonal differences in Xi’an;such measures should target not only the severe problem with VOC pollution but also the problem of consequent secondary pollution(e.g.,from ozone and secondary organic aerosols). 展开更多
关键词 NMHCS OVOCs source apportionment Hybrid environmental Receptor model
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A Framework of Environmental Modelling and Information Sharing for Urban Air Pollution Control and Management 被引量:4
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作者 LIU Gang-jun FU Er-jiang +3 位作者 WANG Yun-jia ZHANG Ke-fei HAN Bao-ping ARROWSMITH Colin 《Journal of China University of Mining and Technology》 EI 2007年第2期172-178,共7页
More effective environmental pollution control and management are needed due to the increasing environ-mental impacts from a range of human activities and the growing public demands for a better living environment. Ur... More effective environmental pollution control and management are needed due to the increasing environ-mental impacts from a range of human activities and the growing public demands for a better living environment. Urban air pollution is a serious environmental issue that poses adverse impacts on the health of people and the environment in most metropolitan areas. In this paper,we propose a geoinformatics augmented framework of environmental modelling and information sharing for supporting effective urban air pollution control and management. This framework is out-lined in terms of its key components and processes including: 1) an integrated,adaptive network of sensors for envi-ronmental monitoring; 2) a set of distributed,interoperable databases for data management; 3) a set of intelligent,robust algorithms and models for environmental modelling; 4) a set of flexible,efficient user interfaces for data access and in-formation sharing; and 5) a reliable,high capacity,high performance computing and communication infrastructure for integrating and supporting other framework components and processes. 展开更多
关键词 environmental modelling information sharing urban air pollution GEOINFORMATICS
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RESEARCH AND PRACTICE FOR MANUFACTURING ENVIRONMENT MODELLING TECHNOLOGY OF CIMS
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作者 Ma Dengzhe Jin Ye +1 位作者 Ming Xinguo Yan Junqi(Shanghai Jiaotong University) 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 1994年第3期211-218,224,共17页
An abstract model and representation method for manufacturing environment is presented based on analysis of process planning tasks and factory configuration capable of handling the process plans. This model has been p... An abstract model and representation method for manufacturing environment is presented based on analysis of process planning tasks and factory configuration capable of handling the process plans. This model has been proved to be applicable to the generative process planning and to shopflow control information integration. A general manufacturing environment modelling tool has been developed under the X-window support to verity the mentioned model and modelling technology. 展开更多
关键词 Process planning Manufacturing environment modelling technology Work-element Manufacturing entity
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A stock assessment for Illex argentinus in Southwest Atlantic using an environmentally dependent surplus production model 被引量:4
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作者 WANG Jintao CHEN Xinjun +1 位作者 Kevin W.Staples CHEN Yong 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2018年第2期94-101,共8页
The southern Patagonian stock(SPS) of Argentinian shortfin squid, Illex argentinus, is an economically important squid fishery in the Southwest Atlantic. Environmental conditions in the region play an important role... The southern Patagonian stock(SPS) of Argentinian shortfin squid, Illex argentinus, is an economically important squid fishery in the Southwest Atlantic. Environmental conditions in the region play an important role in regulating the population dynamics of the I. argentinus population. This study develops an environmentally dependent surplus production(EDSP) model to evaluate the stock abundance of I. argentines during the period of 2000 to 2010. The environmental factors(favorable spawning habitat areas with sea surface temperature of 16–18°C) were assumed to be closely associated with carrying capacity(K) in the EDSP model. Deviance Information Criterion(DIC) values suggest that the estimated EDSP model with environmental factors fits the data better than a Schaefer surplus model without environmental factors under uniform and normal scenarios.The EDSP model estimated a maximum sustainable yield(MSY) from 351 600 t to 685 100 t and a biomass from 1 322 400 t to1 803 000 t. The fishing mortality coefficient of I. argentinus from 2000 to 2010 was smaller than the values of F(0.1) and F(MSY). Furthermore, the time series biomass plot of I. argentinus from 2000 to 2010 shows that the biomass of I.argentinus and this fishery were in a good state and not presently experiencing overfishing. This study suggests that the environmental conditions of the habitat should be considered within squid stock assessment and management. 展开更多
关键词 Illex argentinus stock assessment Schaefer surplus production model environmental factors Southwest Atlantic
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The Impact of Strengthening Environmental Regulatory Policy on China's Economy——Evaluation Based on CGE Model 被引量:3
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作者 李钢 董敏杰 沈可挺 《China Economist》 2014年第4期30-41,共12页
This paper has established a computable general equilibrium(CGE) model taking into account the costs of environmental regulation to evaluate the overall impact of enhanced environmental regulation on China's econo... This paper has established a computable general equilibrium(CGE) model taking into account the costs of environmental regulation to evaluate the overall impact of enhanced environmental regulation on China's economy.The results demonstrate that if environmental regulation is strengthened to the point at which industrial waste discharge meets the current legal standard,economic growth rate will decrease by approximately1%,employment in the manufacturing sector will decrease by approximately 1.8%,and the total value of exports will decrease by approximately 1.7%.The report also shows that enhanced environmental regulation has impacted each region of China differently.This paper argues that during the implementation of environmental regulation,policymakers will need to have a complete understanding of potential regional and structural impacts.China's environmental regulation policy should be implemented gradually,beginning with key polluting industries and those with low correlation to economic growth.Additionally,this paper proposes that environmental regulation should be carried out during periods of economic growth. 展开更多
关键词 environmental regulation CGE model environmental tax
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Application of the AERMOD modeling system for environmental impact assessment of NO_2 emissions from a cement complex 被引量:19
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作者 Kanyanee Seangkiatiyuth Vanisa Surapipith +1 位作者 Kraichat Tantrakarnapa Anchaleeporn W.Lothongkum 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2011年第6期931-940,共10页
We applied the model of American Meteorological Society-Environmental Protection Agency Regulatory Model(AERMOD) as a tool for the analysis of nitrogen dioxide(NO2) emissions from a cement complex as a part of the... We applied the model of American Meteorological Society-Environmental Protection Agency Regulatory Model(AERMOD) as a tool for the analysis of nitrogen dioxide(NO2) emissions from a cement complex as a part of the environmental impact assessment.The dispersion of NO2 from four cement plants within the selected cement complex were investigated both by measurement and AERMOD simulation in dry and wet seasons.Simulated values of NO2 emissions were compared with those obtained during a 7-day continuous measurement campaign at 12 receptors.It was predicted that NO2 concentration peaks were found more within 1 to 5 km,where the measurement and simulation were in good agreement,than at the receptors 5 km further away from the reference point.The QuantileQuantile plots of NO2 concentrations in dry season were mostly fitted to the middle line compared to those in wet season.This can be attributed to high NO2 wet deposition.The results show that for both the measurement and the simulation using the AERMOD,NO2 concentrations do not exceed the NO2 concentration limit set by the National Ambient Air Quality Standards(NAAQS) of Thailand.This indicates that NO2 emissions from the cement complex have no significant impact on nearby communities.It can be concluded that the AERMOD can provide useful information to identify high pollution impact areas for the EIA guidelines. 展开更多
关键词 AERMOD environmental impact assessment Gaussian model air pollutants NO2 cement plant
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SCALE AND TIME EFFECTS ON MATHEMATICAL MODELS FOR TRANSPORT IN THE ENVIRONMENT
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作者 Su Ninghu School of Mathematics and Computational Science,Xiangtan University,Hunan 411105,China School of Earth and Environmental Sciences,James Cook University,Cairns, Queensland 4870,Australia Department of Natural Resources and Water,Mareeba,Queensland 4880,Australia. 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2007年第3期267-276,共10页
The purpose of this paper is to analyse mathematical models used in environmental modelling. Following a brief survey of the development in modelling scale- and time-dependent dispersion processes in the environment, ... The purpose of this paper is to analyse mathematical models used in environmental modelling. Following a brief survey of the development in modelling scale- and time-dependent dispersion processes in the environment, this paper compares three similarity solutions, one of which is a solution of the generalized Feller equation (GF) with fractal parameters, and the other two for the newly-developed generalized Fokker-Planck equation (GFP). The three solutions are derived with parameters having physical significance. Data from field experiments are used to verify the solutions. The analyses indicate that the solutions of both GF and GFP represent the physically meaningful natural processes, and simulate the realistic shapes of tracer breakthrough curves. 展开更多
关键词 mathematical model environmental modelling generalized Feller equation generalized Fokker-Planck equation.
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Environmental input-output model and its analysis with a focus on the solid waste management sectors
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作者 Zeng, Guang-Ming Yuan, Xing-Zhong +3 位作者 Zhang, Pan-Yue Guo, Huai-Cheng Huang, Gordon Guo-He Hemelaar, L. 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2000年第2期53-58,共6页
An environmental input output model (EIOM) was introduced to the regional solid waste management sectors, which can reflect the direct and indirect relations between the environment and the regional economy developme... An environmental input output model (EIOM) was introduced to the regional solid waste management sectors, which can reflect the direct and indirect relations between the environment and the regional economy development. Some details about how to use the EIOM was discussed. The EIOM was applied to the Changsha City in China. The example results indicate that much useful information related to the environment and the regional economy development can be gained from the solution of the EIOM. Thus, the EIOM can be used as a useful tool for the sustainable development planning including the solid waste management sectors. 展开更多
关键词 environmental input\|output model analysis of economy and environment solid waste management
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Fractional Order Environmental and Economic Model Investigations Using Artificial Neural Network
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作者 Wajaree Weera Chantapish Zamart +5 位作者 Zulqurnain Sabir Muhammad Asif Zahoor Raja Afaf S.Alwabli S.R.Mahmoud Supreecha Wongaree Thongchai Botmart 《Computers, Materials & Continua》 SCIE EI 2023年第1期1735-1748,共14页
The motive of these investigations is to provide the importance and significance of the fractional order(FO)derivatives in the nonlinear environmental and economic(NEE)model,i.e.,FO-NEE model.The dynamics of the NEE m... The motive of these investigations is to provide the importance and significance of the fractional order(FO)derivatives in the nonlinear environmental and economic(NEE)model,i.e.,FO-NEE model.The dynamics of the NEE model achieves more precise by using the form of the FO derivative.The investigations through the non-integer and nonlinear mathematical form to define the FO-NEE model are also provided in this study.The composition of the FO-NEEmodel is classified into three classes,execution cost of control,system competence of industrial elements and a new diagnostics technical exclusion cost.The mathematical FO-NEE system is numerically studied by using the artificial neural networks(ANNs)along with the Levenberg-Marquardt backpropagation method(ANNs-LMBM).Three different cases using the FO derivative have been examined to present the numerical performances of the FO-NEE model.The data is selected to solve the mathematical FO-NEE system is executed as 70%for training and 15%for both testing and certification.The exactness of the proposed ANNs-LMBM is observed through the comparison of the obtained and the Adams-Bashforth-Moulton database results.To ratify the aptitude,validity,constancy,exactness,and competence of the ANNs-LMBM,the numerical replications using the state transitions,regression,correlation,error histograms and mean square error are also described. 展开更多
关键词 environmental and economic model artificial neural networks fractional order NONLINEAR Levenberg-Marquardt backpropagation
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Countermeasures for Solving the Environmental Problems and Accelerating the Model City Construction of Xi'an
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作者 Liu Zhenxiang Song Ting Ma Longbao 《Meteorological and Environmental Research》 CAS 2014年第2期55-58,62,共5页
Through careful study, it found that the key and difficult points of affecting and restricting Xi'an to reach the model city construction standards in provincial and national levels were "urban air environment quali... Through careful study, it found that the key and difficult points of affecting and restricting Xi'an to reach the model city construction standards in provincial and national levels were "urban air environment quality standards" and "water qualification rate of urban water environment function area". In order to tackle with the weak links, highlight the important points and focus on the difficult points to strengthen scientific and technological innovation, we actively explored new ideas and ways to resolve the dilemma in meeting the two standards of model city construction, and we managed to put forward the countermeasures to resolve the dilemma through innovating system and mechanism. "Place master system" should be carded out quickly to meet the "urban air environment quality standards", while "river master system" should be implemented as soon as possible to reach the "water qualification rate of urban water environment function area". The aim of this study was to enhance the qualification rates of the indicators for model city construction to make Xi'an successfully pass the provincial and national assessment of model city construction through dealing with the weak links to accelerate the realization of becoming model environmental protection city. 展开更多
关键词 model environmental protection city construction COUNTERMEASURES environmental problems China
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Modelling Environmental Attitudes of the Users of Kilombero Valley Wetlands, Tanzania
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作者 Felister Mombo Zuzanna Pieniak Valerie Vandermeulen 《Journal of Water Resource and Protection》 2016年第12期1078-1089,共12页
Development policies have for a long time made it more profitable for people to degrade than to conserve environment. The adoption of these economic wide policies by Africa especially during colonial time and after in... Development policies have for a long time made it more profitable for people to degrade than to conserve environment. The adoption of these economic wide policies by Africa especially during colonial time and after independence has resulted into erosion of its communities’ conservation behaviour and attitude. Although many studies assess environmental attitudes, those focussing on African regions or countries using New Environmental Paradigm (NEP) scale are very limited. Such studies in the African context using NEP scale are very important, simply because many people depend on the environment for their livelihood, and in the process they destroy the world’s valued ecosystems including wetlands. This study is meant to fill in the gap using Kilombero valley wetlands in Tanzania as a case. The study used Structural Equation Modelling (SEM) to predict the behaviour of the users based on attitudes, environmental knowledge and awareness. The findings indicate that users of the Kilombero wetlands have a generally positive attitude towards the environment, despite a great degree of variability among the study participants. The study shows also that a certain level of environmental awareness is needed in order to increase people’s knowledge about environmental issues and change their environmental attitudes. The NEP scale does not fully fit into the Tanzanian context, thus suggesting that further research into the adaptation of the scale is needed. 展开更多
关键词 modelling environmental Attitudes AWARENESS Knowledge NEP-Scale
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An Environmental Risk Evaluation Method Employing Atmospheric Dispersion Models and GIS 被引量:1
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作者 Masakazu Ishii Kayoko Yamamoto 《Journal of Environmental Protection》 2013年第12期1392-1408,共17页
This study aims to develop a method for evaluating the environmental risk of harmful chemical substances released from specific sources, using two atmospheric dispersion models and GIS (Geographic Information Systems)... This study aims to develop a method for evaluating the environmental risk of harmful chemical substances released from specific sources, using two atmospheric dispersion models and GIS (Geographic Information Systems). In the first stage of evaluation, ADMER was used to conduct a wide-area evaluation which covered the entire area of the evaluation target region. In the second stage, METI-LIS was used to conduct a detailed limited-area evaluation which targeted the vicinity of sources. In this study, incinerators were selected as sources and dioxins were selected as harmful chemical substances. The area selected for evaluation was the Tokyo Metropolis in Japan, and the evaluation method proposed in this study was used to evaluate environmental risk. Through the use of atmospheric dispersion models and GIS, the behavior of dioxins emitted into the atmosphere from incinerators was estimated. By superimposing atmospheric levels and population data, the amounts of dioxins that humans exposed to were found. Additionally, by superimposing deposition amounts and land use data, the amounts of dioxins accumulated in each land environment were found. Conducting these steps enabled the impact of dioxins on humans and the environment to be grasped quantitatively and visually, and the risk that dioxins emitted from incinerators pose to the environment to be evaluated. 展开更多
关键词 environmentAL Risk ATMOSPHERIC DISPERSION models GIS DIOXINS INCINERATOR
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Study on Index System of the Environmental Change and Ecological Security for a River Basin Based on DPSIR Model 被引量:1
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作者 YAO Yuan 《Meteorological and Environmental Research》 2012年第6期50-54,共5页
[ Objective] The research aimed to study index system of the environmental change and ecological security for a river basin based on DPSIR model. [Method] Based on considering each influence factor of the environmenta... [ Objective] The research aimed to study index system of the environmental change and ecological security for a river basin based on DPSIR model. [Method] Based on considering each influence factor of the environmental change and ecological security for a river basin, DPSIR model as framework, the basic framework, principle and related method of index system of the environmental change and ecological security for a river basin under influence of the multi-level development were put forward. [ ]Result] Index system of the environmental change and ecological se- curity for a river basin based on DPSIR model included driving force indicator, pressure indicator, state indicator, influence indicator and response indicator. Each indicator type also had many sub-indicators. [ Conclusion] The research provided theoretical support and method reference for as- sessment of the ecological security and execution of the ecological environment management for a river basin in China. 展开更多
关键词 DPSIR model environmental change Ecological security Index system China
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Study of monthly variations in primary production and their relationships with environmental factors in the Daya Bay based on a general additive model 被引量:1
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作者 KANG Jianhua HUANG Hao +2 位作者 LI Weiwen LIN Yili CHEN Xingqun 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2018年第12期107-117,共11页
In this study, the horizontal and vertical distribution of primary production(PP) and its monthly variations were described based on field data collected from the Daya Bay in January–December of 2016. The relationshi... In this study, the horizontal and vertical distribution of primary production(PP) and its monthly variations were described based on field data collected from the Daya Bay in January–December of 2016. The relationships between PP and environmental factors were analyzed using a general additive model(GAM). Significant seasonal differences were observed in the horizontal distribution of PP, while vertical distribution showed a relatively consistent unimodal pattern. The monthly average PP(calculated by carbon) ranged from 48.03 to 390.56 mg/(m~2·h),with an annual average of 182.77 mg/(m~2·h). The highest PP was observed in May and the lowest in November.Additionally, the overall trend in PP was spring>summer>winter>autumn, and spring PP was approximately three times that of autumn PP. GAM analysis revealed that temperature, bottom salinity, phytoplankton, and photosynthetically active radiation(PAR) had no significant relationships with PP, while longitude, depth, surface salinity, chlorophyll a(Chl a) and transparency were significantly correlated with PP. Overall, the results presented herein indicate that monsoonal changes and terrestrial and offshore water systems have crucial effects on environmental factors that are associated with PP changes. 展开更多
关键词 primary production environmental factors general additive model monthly variations Daya Bay
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Spatial Analysis for Flood Control by Using Environmental Modeling
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作者 Alireza Gharagozlou Hassan Nazari Mohammadjavad Seddighi 《Journal of Geographic Information System》 2011年第4期367-372,共6页
To create the final spatial information and analysis, flood hazard maps and land development priority maps and information, data for the flood events to 2009 in north of Iran were incorporated with using Geo-spatial I... To create the final spatial information and analysis, flood hazard maps and land development priority maps and information, data for the flood events to 2009 in north of Iran were incorporated with using Geo-spatial Information System data of physiographic divisions, geologic divisions, land cover classification, elevation, drainage network, administrative districts and population density and environmental parameters modeling. Special analysis also attention was paid to population density for the construction of the land development priority map and using satellite image analysis to determine land use changes and analysis of geo-spatial information, because highly dense populated areas represent the highly important urban and industrial areas. While geo-information technology offers an opportunity to support flood management adequate geo-spatial information is a prerequisite for sustainable development, but many parts of the world lack adequate information on environmental resources. Such information providing, which serves as an important tool for decision-making in land use planning, can help provide effective information to natural disaster management. This paper develops a framework for flood control and begins with some general comments on the importance of land use planning and outlines some current environmental issues and then presenting environmental models to use in disaster management plan by using GIS and remote sensing results. Flood control is a complex problem that requires cooperation of many scientists in different fields. The article also discusses the role that geo-information and environmental planning and GIS and remote sensing technology play in disaster management control to reduce negative impacts of flood and present proper alternatives for developing of Gorganrood in the north of Iran. Advanced high-resolution sensor technology has provided immense scope to the decision makers for analysis of flood and damages details using GIS and remote sensing. 展开更多
关键词 environmentAL modeling LAND Use PLANNING Geo-Spatial Information GIS
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Environmental stress model for evaluation of vessel traffic in ports and waterways
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作者 HU Zhiwu CHEN Weijiong INOUE K 《上海海事大学学报》 北大核心 2005年第3期35-39,共5页
Environmental stress model is proposed as an effective tool to the analysis and evaluation of navigational safety in ports and waterways. Marine traffic simulations are carried out in a virtual port area with various ... Environmental stress model is proposed as an effective tool to the analysis and evaluation of navigational safety in ports and waterways. Marine traffic simulations are carried out in a virtual port area with various arrangements and conditions. Calculations of stress values and traffic volume criteria are illustrated. The simulation results provide a valuable hint for safety management of vessel traffic. The model provides quantitative information and helps administrators in decision making to achieve desired safety level and improve the efficiency of vessel traffic in ports and waterways. 展开更多
关键词 船舶 港口 水路 环境压力模型 交通管理
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Stability of a delayed predator prey model in a random environment 被引量:1
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作者 靳艳飞 谢文贤 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第11期140-145,共6页
The stability of the first-order and second-order solution moments for a Harrison-type predator-prey model with parametric Gaussian white noise is analyzed in this paper. The moment equations of the system solution ar... The stability of the first-order and second-order solution moments for a Harrison-type predator-prey model with parametric Gaussian white noise is analyzed in this paper. The moment equations of the system solution are obtained under Ito interpretations. The delay-independent stable condition of the first-order moment is identical to that of the deterministic delayed system, and the delay-independent stable condition of the second-order moment depends on the noise intensities. The corresponding critical time delays are determined once the stabilities of moments lose. Further, when the time delays are greater than the critical time delays, the system solution becomes unstable with the increase of noise intensities. Finally, some numerical simulations are given to verify the theoretical results. 展开更多
关键词 delay-independent stability predator-prey model moment equations environmental noise
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