Security constrained multi area multi objective dynamic economic dispatch (SCMAMODED) with renewable energy (RE) and all the possible MTDC stability constraints is formulated for the first time. The stability merits o...Security constrained multi area multi objective dynamic economic dispatch (SCMAMODED) with renewable energy (RE) and all the possible MTDC stability constraints is formulated for the first time. The stability merits of multi terminal DC (MTDC) tie lines as compared to the traditional HVAC forms the main objective of this paper. Probabilistic load flow (PLF) is applied to determine the system parameters while the uncertainties are modelled using Scenario Based Method (SBM). The simulation results reveal that with the use of MTDC tie lines, the frequency and voltage stability in the MAMODED with renewable energy sources (RES) are enhanced while keeping the MTDC power exchange interface nodes at secure levels.展开更多
The paper proposes a novel H∞ load frequency control(LFC) design method for multi-area power systems based on an integral-based non-fragile distributed fixed-order dynamic output feedback(DOF) tracking-regulator cont...The paper proposes a novel H∞ load frequency control(LFC) design method for multi-area power systems based on an integral-based non-fragile distributed fixed-order dynamic output feedback(DOF) tracking-regulator control scheme. To this end, we consider a nonlinear interconnected model for multiarea power systems which also include uncertainties and timevarying communication delays. The design procedure is formulated using semi-definite programming and linear matrix inequality(LMI) method. The solution of the proposed LMIs returns necessary parameters for the tracking controllers such that the impact of model uncertainty and load disturbances are minimized. The proposed controllers are capable of receiving all or part of subsystems information, whereas the outputs of each controller are local. These controllers are designed such that the resilient stability of the overall closed-loop system is guaranteed. Simulation results are provided to verify the effectiveness of the proposed scheme. Simulation results quantify that the distributed(and decentralized) controlled system behaves well in presence of large parameter perturbations and random disturbances on the power system.展开更多
This paper is devoted to investigate the robust H∞sliding mode load frequency control(SMLFC) of multi-area power system with time delay. By taking into account stochastic disturbances induced by the integration of re...This paper is devoted to investigate the robust H∞sliding mode load frequency control(SMLFC) of multi-area power system with time delay. By taking into account stochastic disturbances induced by the integration of renewable energies,a new sliding surface function is constructed to guarantee the fast response and robust performance, then the sliding mode control law is designed to guarantee the reach ability of the sliding surface in a finite-time interval. The sufficient robust frequency stabilization result for multi-area power system with time delay is presented in terms of linear matrix inequalities(LMIs). Finally,a two-area power system is provided to illustrate the usefulness and effectiveness of the obtained results.展开更多
This paper presents a novel approach to solve the Multi-Area unit commitment problem using particle swarm optimization technique. The objective of the multi-area unit commitment problem is to determine the optimal or ...This paper presents a novel approach to solve the Multi-Area unit commitment problem using particle swarm optimization technique. The objective of the multi-area unit commitment problem is to determine the optimal or a near optimal commitment strategy for generating the units. And it is located in multiple areas that are interconnected via tie lines and joint operation of generation resources can result in significant operational cost savings. The dynamic programming method is applied to solve Multi-Area Unit Commitment problem and particle swarm optimization technique is embedded for computing the generation assigned to each area and the power allocated to all committed unit. Particle Swarm Optimization technique is developed to derive its Pareto-optimal solutions. The tie-line transfer limits are considered as a set of constraints during the optimization process to ensure the system security and reliability. Case study of four areas each containing 26 units connected via tie lines has been taken for analysis. Numerical results are shown comparing the cost solutions and computation time obtained by using the Particle Swarm Optimization method is efficient than the conventional Dynamic Programming and Evolutionary Programming Method.展开更多
Leaves are the main organs of photosynthesis in green plants. Leaf area plays a vital role in dry matter accumulation and grain yield in maize （Zea mays L.）. Thus, investigating the genetic basis of leaf area will a...Leaves are the main organs of photosynthesis in green plants. Leaf area plays a vital role in dry matter accumulation and grain yield in maize （Zea mays L.）. Thus, investigating the genetic basis of leaf area will aid efforts to breed maize with high yield. In this study, a total of 150 F7 recombinant inbred lines （RILs） derived from a cross between the maize lines Xu 178 and K12 were used to evaluate three ear-leaves area （TELA） under multi-environments. Inclusive composite interval map- ping （ICIM） was used to identify quantitative trait loci （QTLs） for TELA under a single environment and estimated breeding value （EBV）. A total of eight QTLs were detected under a single environmental condition, and four QTLs were identified for EBV which also can be detected in single environment. This indicated that the EBV-detected QTLs have high genetic stability. A major QTL （qTELA_2-9） located in chromosome bin 2.04/2.05 could be detected in four environments and has a high phenotypic contribution rate （ranging from 10.79 to 16.51%） that making it a good target for molecular breeding. In addition, joint analysis was used to reveal the genetic basis of leaf area in six environments. In total, six QTLxenvironment interactions and nine epistatic interactions were identified. Our results reveal that the genetic basis of the leaf area is not only mainly determined by additive effects, but also affected by epistatic effects environmental interaction effects.展开更多
Surface gas discharge(SGD)plasmas have potential applications in the fields of active flow control,gas purification,heat transfer enhancement,etc.In order to obtain a uniform,stable and large-area SGD at atmosphere,a ...Surface gas discharge(SGD)plasmas have potential applications in the fields of active flow control,gas purification,heat transfer enhancement,etc.In order to obtain a uniform,stable and large-area SGD at atmosphere,a multi-electrode SGD plasma generator is designed in this paper.The major features of this newly-designed SGD plasma generator is as follows:the air-exposed upper grounded electrodes are made of nine tungsten wires and flush mounted on the dielectric PTFE barrier layer,while the lower powered electrode is made of a copper foil and encapsulated inside the PTFE material to avoid the ignition of the gas discharges below the dielectric barrier layer.The measurements on the electrical characteristics,fast imaging of discharges and the preliminary numerical analysis on the electric field distributions suggest that the multi-electrode configuration of the plasma generator plays a crucial role in enhancing the local electrical field,and subsequently,leads to the stable,quasi-uniform and large-area surface discharges.展开更多
This study discussed the contradiction and reform experience of multi-plan integration in Sihui from the perspective of spatial governance.The research found:in terms of contradictions,the right and responsibility of ...This study discussed the contradiction and reform experience of multi-plan integration in Sihui from the perspective of spatial governance.The research found:in terms of contradictions,the right and responsibility of management departments in the county area of Sihui were crosscutting,the township governance responsibilities needed urgent improvement,the urban-rural governance problems were different,the spatial governance elements were not unified,and the contradiction in the implementation mechanism was the implementation of projects.Through the multi-plan integration reform,Sihui reconstructed the right and responsibility relationship of the spatial governance departments,unified the elements of spatial governance,and refactored the implementation mechanism by reconstructing the transmission mechanism of the spatial planning system and the project approval mechanism and establishing the dynamic evaluation and adjustment mechanism.展开更多
In recent years, with the rapid development of urbanization in China, land acquisition work is particularly important. The division of expropriated area is the primary factor to be considered when evaluating the compr...In recent years, with the rapid development of urbanization in China, land acquisition work is particularly important. The division of expropriated area is the primary factor to be considered when evaluating the comprehensive land price of expropriated area. Reasonable division can help to improve the scientific and applicability of the comprehensive land price of the region. How to maximize the protection of farmers’ rights and interests by the division of land requisition is an urgent problem to be solved. Taking Gongcheng Yao Autonomous County as an example, this study adopted the multi-factor comprehensive evaluation method to evaluate the division of land requisition in this area, and carried out the corresponding spatial analysis and data processing based on GIS technology. Gongcheng Yao Autonomous County was divided into levy areas, and the Delphi method was used to screen the impact factors and determine the weight of the levy areas. Reasonable division of land requisition area can provide references for land requisition area, make it more scientific and reasonable, and protect the rights and interests of farmers.展开更多
In this paper, through a multi-scale separation of the aeromagnetic anomaly by wavelet transform technique, we reprocessed the aeromagnetic data collected 20 years ago in Beijing area and analyzed the aeromagnetic ano...In this paper, through a multi-scale separation of the aeromagnetic anomaly by wavelet transform technique, we reprocessed the aeromagnetic data collected 20 years ago in Beijing area and analyzed the aeromagnetic anomaly qualitatively, integrating geological structure features in the area. In particular, we studied the spatial distributions of the two main faults called Shunyi-Liangxiang fault and Banqiao-Babaoshan-Tongxian fault, which have cut and gone through the central Beijing area striking in NE and EW directions, respectively. The influences of these two faults on the earthquakes have also been discussed briefly.展开更多
This work proposes a novel nature-inspired algorithm called Ant Lion Optimizer (ALO). The ALO algorithm mimics the search mechanism of antlions in nature. A time domain based objective function is established to tune ...This work proposes a novel nature-inspired algorithm called Ant Lion Optimizer (ALO). The ALO algorithm mimics the search mechanism of antlions in nature. A time domain based objective function is established to tune the parameters of the PI controller based LFC, which is solved by the proposed ALO algorithm to reach the most convenient solutions. A three-area interconnected power system is investigated as a test system under various loading conditions to confirm the effectiveness of the suggested algorithm. Simulation results are given to show the enhanced performance of the developed ALO algorithm based controllers in comparison with Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Bat Algorithm (BAT) and conventional PI controller. These results represent that the proposed BAT algorithm tuned PI controller offers better performance over other soft computing algorithms in conditions of settling times and several performance indices.展开更多
This paper proposed a robust method based on the definition of Mahalanobis distance to track ground moving target. The feature and the geometry of airborne ground moving target tracking systems are studied at first. B...This paper proposed a robust method based on the definition of Mahalanobis distance to track ground moving target. The feature and the geometry of airborne ground moving target tracking systems are studied at first. Based on this feature, the assignment relation of time-nearby target is calculated via Mahalanobis distance, and then the corresponding transformation formula is deduced. The simulation results show the correctness and effectiveness of the proposed method.展开更多
Planning of waste management system in urban area should take into consideration many legal, technological, financial, economic, technical, ecological, social and spatial aspects. The aim of the paper is to propose th...Planning of waste management system in urban area should take into consideration many legal, technological, financial, economic, technical, ecological, social and spatial aspects. The aim of the paper is to propose the method, which can be helpful in planning procedure of waste management system in European cities or regions, which comprise with following steps: identification of produced volume and municipal solid waste characteristics in the region for providing grounds to design a technological system, identification of other financial, economic, legal, social aspects for creation of waste management scenarios, definition of the criteria allowing evaluate designed waste management scenarios based on plan requirements, make an the multi-criteria analysis for choosing the best scenario in the region. Such analyses were conducted to evaluate the proposed different waste management systems in city of Cracow in 2000, 2004 and 2007. This comparison of theses systems shows that evaluating criteria were tightened as a result of toughening regulations of both Polish and the EU laws.展开更多
This paper introduces a multi-model approach to design a robust supplementary damping controller. The designed fixed-order supplementary damping controller adjusts the voltage reference set point of SVC. There are two...This paper introduces a multi-model approach to design a robust supplementary damping controller. The designed fixed-order supplementary damping controller adjusts the voltage reference set point of SVC. There are two main objectives of the controller design, damping low frequencies oscillations and enhancing power system stability. This method relies on shaping the closed-loop sensitivity functions in the Nyquist plot under the constraints of these functions. These constraints can be linearized by choosing a desired open-loop transfer function. The robust controller is designed to minimize the error between the open-loop of the original plant model and the desired transfer functions. These outcomes can be achieved by using convex optimization methods. Convexity of the problem formulation ensures global optimality. One of the advantages of the proposed approach is that the approach accounts for multi-model uncertainty. In contrast to the methods available in the literature, the proposed approach deals with full-order model (i.e., model reduction is not required) with lower controller order. The issue of time delay of feedback signals has been addressed in this paper for different values of time delay by applying a multi-model optimization technique. The proposed approach is compared to other existing techniques to design a robust controller which is based on H2 under pole placement. Both techniques are applied to the 68-bus system to evaluate and validate the robust controller performance under different load scenarios and different wind generations.展开更多
Studies of offshore wave climate based on satellite altimeter significant wave height（SWH） have widespread application value. This study used a calibrated multi-altimeter SWH dataset to investigate the wave climate ...Studies of offshore wave climate based on satellite altimeter significant wave height（SWH） have widespread application value. This study used a calibrated multi-altimeter SWH dataset to investigate the wave climate characteristics in the offshore areas of China. First, the SWH measurements from 28 buoys located in China＇s coastal seas were compared with an Ifremer calibrated altimeter SWH dataset. Although the altimeter dataset tended to slightly overestimate SWH, it was in good agreement with the in situ data in general. The correlation coefficient was 0.97 and the root-mean-square（RMS） of differences was 0.30 m. The validation results showed a slight difference in different areas. The correlation coefficient was the maximum（0.97） and the RMS difference was the minimum（0.28 m） in the area from the East China Sea to the north of the South China Sea.The correlation coefficient of approximately 0.95 was relatively low in the seas off the Changjiang（Yangtze River） Estuary. The RMS difference was the maximum（0.32 m） in the seas off the Changjiang Estuary and was0.30 m in the Bohai Sea and the Yellow Sea. Based on the above evidence, it is confirmed that the multialtimeter wave data are reliable in China＇s offshore areas. Then, the characteristics of the wave field, including the frequency of huge waves and the multi-year return SWH in China＇s offshore seas were analyzed using the23-year altimeter wave dataset. The 23-year mean SWH generally ranged from 0.6-2.2 m. The greatest SWH appeared in the southeast of the China East Sea, the Taiwan Strait and the northeast of the South China Sea.Obvious seasonal variation of SWH was found in most areas; SWH was greater in winter and autumn than in summer and spring. Extreme waves greater than 4 m in height mainly occurred in the following areas： the southeast of the East China Sea, the south of the Ryukyu Islands, the east of Taiwan-Luzon Island, and the Dongsha Islands extending to the Zhongsha Islands, and the frequency of extreme waves was 3%-6%. Extreme waves occurred most frequently in autumn and rarely in spring. The 100-year return wave height was greatest from the northwest Pacific seas extending to southeast of the Ryukyu Islands（9-12 m）, and the northeast of the South China Sea and the East China Sea had the second largest wave heights（7-11 m）. For inshore areas, the100-year return wave height was the greatest in the waters off the east coast of Guangdong Province and the south coast of Zhejiang Province（7-8 m）, whereas it was at a minimum in the area from the Changjiang Estuary to the Bohai Sea（4-6 m）. An investigation of sampling effects indicates that when using the 1°×1°grid dataset, although the combination of nine altimeters obviously enhanced the time and space coverage of sampling, the accuracy of statistical results, particularly extreme values obtained from the dataset, still suffered from undersampling problems because the time sampling percent in each 1°×1°grid cell was always less than33%.展开更多
A 24-acre land at Aboso serves as the site where municipal solid waste from Tarkwa and its environs are openly dumped. Evaluation of the suitability of this existing landfill site for the construction of an engineered...A 24-acre land at Aboso serves as the site where municipal solid waste from Tarkwa and its environs are openly dumped. Evaluation of the suitability of this existing landfill site for the construction of an engineered landfill was determined. Reconnaissance survey, structural mapping, determination of depth to groundwater, geotechnical site investigation as well as socio-economic indicators showed that the existing landfill site is not suitable for an engineered landfill construction. A multi-criteria GIS model was used to select an alternative suitable area for the construction of an engineered landfill. The multicriteria GIS modelling identified fourteen (14) suitable areas for the siting of landfill in the Tarkwa area. A site located in Domeabra was chosen due to its proximity to the neighbouring communities of Tarkwa, Nsuta and Aboso. The suitability of the proposed site in Domeabra was assessed using geotechnical and geophysical methods. The geotechnical methods included the testing of soil properties such as moisture content, particle size distribution, Atterberg limit, bulk density, specific gravity, and compactibility. The soils at Domeabra site are predominantly gravel and sand, well graded with gradual increase in clay content with depth and good moisture content (less than 30%). The gravel and sandy soils have good to excellent shear strength and work ability. The soils in Domeabra have suitable dry density (1.3 - 2.1 Mg/m3), bulk density (1.7 - 2.5 Mg/m3) and specific gravity (2.2 - 2.9) for landfill construction. The geophysical method involved the use of seismic refraction tomography. The geophysical survey showed that the site is made up of four layers namely the top soil (0.5 - 2 m), weathered material (5 - 15 m), saturated material (10 - 15 m) and fresh rock. The water table occurs at a depth of 12 to 15 m. The proposed area in Domeabra based on the geophysical and geotechnical investigations is suitable for the construction of engineered landfill.展开更多
Songpan County is a poverty-stricken county in Tibetan areas of Sichuan Province,it belongs to a concentrated poverty-stricken area in China.Through summarizing the specific conditions of multi-level cooperation and c...Songpan County is a poverty-stricken county in Tibetan areas of Sichuan Province,it belongs to a concentrated poverty-stricken area in China.Through summarizing the specific conditions of multi-level cooperation and complementary advantage poverty alleviation model in Songpan County,this paper analyzed the effect of this model.Through the analysis on the cooperative poverty alleviation model(eastern-western cooperation,provincial targeted assistance,county-wide"four-leading and four-assistance"inner-party assistance,social force"10000 enterprises helping 10000 villages",and"visiting every household and keeping every person busy"),it summarized the implementation and actual results of each level.In addition,it summarized the problems encountered in the implementation process of multi-level cooperation and complementary advantage poverty alleviation model and came up with recommendations.With the aid of this successful multi-level cooperation and complementary advantage poverty alleviation model,Songpan County has achieved a decisive victory in the fight against poverty.At the end of April 2019,the poverty rate in the whole region fell to 0.45%,and it successfully took off the poverty hat.This paper analyzed and refined the specific practice,main achievements,successful experience,implications and reference significance of multi-level cooperation and complementary advantage poverty alleviation model,to provide necessary references for innovation of poverty alleviation model in poverty-stricken Tibetan areas,or even other similar provinces and regions.展开更多
文摘Security constrained multi area multi objective dynamic economic dispatch (SCMAMODED) with renewable energy (RE) and all the possible MTDC stability constraints is formulated for the first time. The stability merits of multi terminal DC (MTDC) tie lines as compared to the traditional HVAC forms the main objective of this paper. Probabilistic load flow (PLF) is applied to determine the system parameters while the uncertainties are modelled using Scenario Based Method (SBM). The simulation results reveal that with the use of MTDC tie lines, the frequency and voltage stability in the MAMODED with renewable energy sources (RES) are enhanced while keeping the MTDC power exchange interface nodes at secure levels.
文摘The paper proposes a novel H∞ load frequency control(LFC) design method for multi-area power systems based on an integral-based non-fragile distributed fixed-order dynamic output feedback(DOF) tracking-regulator control scheme. To this end, we consider a nonlinear interconnected model for multiarea power systems which also include uncertainties and timevarying communication delays. The design procedure is formulated using semi-definite programming and linear matrix inequality(LMI) method. The solution of the proposed LMIs returns necessary parameters for the tracking controllers such that the impact of model uncertainty and load disturbances are minimized. The proposed controllers are capable of receiving all or part of subsystems information, whereas the outputs of each controller are local. These controllers are designed such that the resilient stability of the overall closed-loop system is guaranteed. Simulation results are provided to verify the effectiveness of the proposed scheme. Simulation results quantify that the distributed(and decentralized) controlled system behaves well in presence of large parameter perturbations and random disturbances on the power system.
基金supported in part by the National Natural Science Foundation of China(61673161)the Natural Science Foundation of Jiangsu Province of China(BK20161510)+2 种基金the Fundamental Research Funds for the Central Universities of China(2017B13914)the 111 Project(B14022)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘This paper is devoted to investigate the robust H∞sliding mode load frequency control(SMLFC) of multi-area power system with time delay. By taking into account stochastic disturbances induced by the integration of renewable energies,a new sliding surface function is constructed to guarantee the fast response and robust performance, then the sliding mode control law is designed to guarantee the reach ability of the sliding surface in a finite-time interval. The sufficient robust frequency stabilization result for multi-area power system with time delay is presented in terms of linear matrix inequalities(LMIs). Finally,a two-area power system is provided to illustrate the usefulness and effectiveness of the obtained results.
文摘This paper presents a novel approach to solve the Multi-Area unit commitment problem using particle swarm optimization technique. The objective of the multi-area unit commitment problem is to determine the optimal or a near optimal commitment strategy for generating the units. And it is located in multiple areas that are interconnected via tie lines and joint operation of generation resources can result in significant operational cost savings. The dynamic programming method is applied to solve Multi-Area Unit Commitment problem and particle swarm optimization technique is embedded for computing the generation assigned to each area and the power allocated to all committed unit. Particle Swarm Optimization technique is developed to derive its Pareto-optimal solutions. The tie-line transfer limits are considered as a set of constraints during the optimization process to ensure the system security and reliability. Case study of four areas each containing 26 units connected via tie lines has been taken for analysis. Numerical results are shown comparing the cost solutions and computation time obtained by using the Particle Swarm Optimization method is efficient than the conventional Dynamic Programming and Evolutionary Programming Method.
基金supported financially by the National Natu ral Science Foundation of China(31301830)the Natural Science Basic Research Plan in Shaanxi Province of China(2014JQ3108)+1 种基金the Special Fund for Basic Research in Northwest A&F University,China(QN2012001)the Chinese Scholarship Council(CSC)
文摘Leaves are the main organs of photosynthesis in green plants. Leaf area plays a vital role in dry matter accumulation and grain yield in maize （Zea mays L.）. Thus, investigating the genetic basis of leaf area will aid efforts to breed maize with high yield. In this study, a total of 150 F7 recombinant inbred lines （RILs） derived from a cross between the maize lines Xu 178 and K12 were used to evaluate three ear-leaves area （TELA） under multi-environments. Inclusive composite interval map- ping （ICIM） was used to identify quantitative trait loci （QTLs） for TELA under a single environment and estimated breeding value （EBV）. A total of eight QTLs were detected under a single environmental condition, and four QTLs were identified for EBV which also can be detected in single environment. This indicated that the EBV-detected QTLs have high genetic stability. A major QTL （qTELA_2-9） located in chromosome bin 2.04/2.05 could be detected in four environments and has a high phenotypic contribution rate （ranging from 10.79 to 16.51%） that making it a good target for molecular breeding. In addition, joint analysis was used to reveal the genetic basis of leaf area in six environments. In total, six QTLxenvironment interactions and nine epistatic interactions were identified. Our results reveal that the genetic basis of the leaf area is not only mainly determined by additive effects, but also affected by epistatic effects environmental interaction effects.
基金Project supported by National Natural Science Foundation of China （10972119 61104204）.
文摘Surface gas discharge(SGD)plasmas have potential applications in the fields of active flow control,gas purification,heat transfer enhancement,etc.In order to obtain a uniform,stable and large-area SGD at atmosphere,a multi-electrode SGD plasma generator is designed in this paper.The major features of this newly-designed SGD plasma generator is as follows:the air-exposed upper grounded electrodes are made of nine tungsten wires and flush mounted on the dielectric PTFE barrier layer,while the lower powered electrode is made of a copper foil and encapsulated inside the PTFE material to avoid the ignition of the gas discharges below the dielectric barrier layer.The measurements on the electrical characteristics,fast imaging of discharges and the preliminary numerical analysis on the electric field distributions suggest that the multi-electrode configuration of the plasma generator plays a crucial role in enhancing the local electrical field,and subsequently,leads to the stable,quasi-uniform and large-area surface discharges.
基金Sponsored by Natural Science Fund of Guangdong Province(2015A030310521)
文摘This study discussed the contradiction and reform experience of multi-plan integration in Sihui from the perspective of spatial governance.The research found:in terms of contradictions,the right and responsibility of management departments in the county area of Sihui were crosscutting,the township governance responsibilities needed urgent improvement,the urban-rural governance problems were different,the spatial governance elements were not unified,and the contradiction in the implementation mechanism was the implementation of projects.Through the multi-plan integration reform,Sihui reconstructed the right and responsibility relationship of the spatial governance departments,unified the elements of spatial governance,and refactored the implementation mechanism by reconstructing the transmission mechanism of the spatial planning system and the project approval mechanism and establishing the dynamic evaluation and adjustment mechanism.
文摘In recent years, with the rapid development of urbanization in China, land acquisition work is particularly important. The division of expropriated area is the primary factor to be considered when evaluating the comprehensive land price of expropriated area. Reasonable division can help to improve the scientific and applicability of the comprehensive land price of the region. How to maximize the protection of farmers’ rights and interests by the division of land requisition is an urgent problem to be solved. Taking Gongcheng Yao Autonomous County as an example, this study adopted the multi-factor comprehensive evaluation method to evaluate the division of land requisition in this area, and carried out the corresponding spatial analysis and data processing based on GIS technology. Gongcheng Yao Autonomous County was divided into levy areas, and the Delphi method was used to screen the impact factors and determine the weight of the levy areas. Reasonable division of land requisition area can provide references for land requisition area, make it more scientific and reasonable, and protect the rights and interests of farmers.
基金National Development and Reform Commission Project ″Experimental Detection of Urban Active Faults″ (2004-1138).
文摘In this paper, through a multi-scale separation of the aeromagnetic anomaly by wavelet transform technique, we reprocessed the aeromagnetic data collected 20 years ago in Beijing area and analyzed the aeromagnetic anomaly qualitatively, integrating geological structure features in the area. In particular, we studied the spatial distributions of the two main faults called Shunyi-Liangxiang fault and Banqiao-Babaoshan-Tongxian fault, which have cut and gone through the central Beijing area striking in NE and EW directions, respectively. The influences of these two faults on the earthquakes have also been discussed briefly.
文摘This work proposes a novel nature-inspired algorithm called Ant Lion Optimizer (ALO). The ALO algorithm mimics the search mechanism of antlions in nature. A time domain based objective function is established to tune the parameters of the PI controller based LFC, which is solved by the proposed ALO algorithm to reach the most convenient solutions. A three-area interconnected power system is investigated as a test system under various loading conditions to confirm the effectiveness of the suggested algorithm. Simulation results are given to show the enhanced performance of the developed ALO algorithm based controllers in comparison with Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Bat Algorithm (BAT) and conventional PI controller. These results represent that the proposed BAT algorithm tuned PI controller offers better performance over other soft computing algorithms in conditions of settling times and several performance indices.
基金Supported by the National Natural Science Foundation of China Youth Science Fund Project(Nos.62101405,61372185)
文摘This paper proposed a robust method based on the definition of Mahalanobis distance to track ground moving target. The feature and the geometry of airborne ground moving target tracking systems are studied at first. Based on this feature, the assignment relation of time-nearby target is calculated via Mahalanobis distance, and then the corresponding transformation formula is deduced. The simulation results show the correctness and effectiveness of the proposed method.
文摘Planning of waste management system in urban area should take into consideration many legal, technological, financial, economic, technical, ecological, social and spatial aspects. The aim of the paper is to propose the method, which can be helpful in planning procedure of waste management system in European cities or regions, which comprise with following steps: identification of produced volume and municipal solid waste characteristics in the region for providing grounds to design a technological system, identification of other financial, economic, legal, social aspects for creation of waste management scenarios, definition of the criteria allowing evaluate designed waste management scenarios based on plan requirements, make an the multi-criteria analysis for choosing the best scenario in the region. Such analyses were conducted to evaluate the proposed different waste management systems in city of Cracow in 2000, 2004 and 2007. This comparison of theses systems shows that evaluating criteria were tightened as a result of toughening regulations of both Polish and the EU laws.
文摘This paper introduces a multi-model approach to design a robust supplementary damping controller. The designed fixed-order supplementary damping controller adjusts the voltage reference set point of SVC. There are two main objectives of the controller design, damping low frequencies oscillations and enhancing power system stability. This method relies on shaping the closed-loop sensitivity functions in the Nyquist plot under the constraints of these functions. These constraints can be linearized by choosing a desired open-loop transfer function. The robust controller is designed to minimize the error between the open-loop of the original plant model and the desired transfer functions. These outcomes can be achieved by using convex optimization methods. Convexity of the problem formulation ensures global optimality. One of the advantages of the proposed approach is that the approach accounts for multi-model uncertainty. In contrast to the methods available in the literature, the proposed approach deals with full-order model (i.e., model reduction is not required) with lower controller order. The issue of time delay of feedback signals has been addressed in this paper for different values of time delay by applying a multi-model optimization technique. The proposed approach is compared to other existing techniques to design a robust controller which is based on H2 under pole placement. Both techniques are applied to the 68-bus system to evaluate and validate the robust controller performance under different load scenarios and different wind generations.
基金The National Natural Science Foundation of China under contract No.41276009
文摘Studies of offshore wave climate based on satellite altimeter significant wave height（SWH） have widespread application value. This study used a calibrated multi-altimeter SWH dataset to investigate the wave climate characteristics in the offshore areas of China. First, the SWH measurements from 28 buoys located in China＇s coastal seas were compared with an Ifremer calibrated altimeter SWH dataset. Although the altimeter dataset tended to slightly overestimate SWH, it was in good agreement with the in situ data in general. The correlation coefficient was 0.97 and the root-mean-square（RMS） of differences was 0.30 m. The validation results showed a slight difference in different areas. The correlation coefficient was the maximum（0.97） and the RMS difference was the minimum（0.28 m） in the area from the East China Sea to the north of the South China Sea.The correlation coefficient of approximately 0.95 was relatively low in the seas off the Changjiang（Yangtze River） Estuary. The RMS difference was the maximum（0.32 m） in the seas off the Changjiang Estuary and was0.30 m in the Bohai Sea and the Yellow Sea. Based on the above evidence, it is confirmed that the multialtimeter wave data are reliable in China＇s offshore areas. Then, the characteristics of the wave field, including the frequency of huge waves and the multi-year return SWH in China＇s offshore seas were analyzed using the23-year altimeter wave dataset. The 23-year mean SWH generally ranged from 0.6-2.2 m. The greatest SWH appeared in the southeast of the China East Sea, the Taiwan Strait and the northeast of the South China Sea.Obvious seasonal variation of SWH was found in most areas; SWH was greater in winter and autumn than in summer and spring. Extreme waves greater than 4 m in height mainly occurred in the following areas： the southeast of the East China Sea, the south of the Ryukyu Islands, the east of Taiwan-Luzon Island, and the Dongsha Islands extending to the Zhongsha Islands, and the frequency of extreme waves was 3%-6%. Extreme waves occurred most frequently in autumn and rarely in spring. The 100-year return wave height was greatest from the northwest Pacific seas extending to southeast of the Ryukyu Islands（9-12 m）, and the northeast of the South China Sea and the East China Sea had the second largest wave heights（7-11 m）. For inshore areas, the100-year return wave height was the greatest in the waters off the east coast of Guangdong Province and the south coast of Zhejiang Province（7-8 m）, whereas it was at a minimum in the area from the Changjiang Estuary to the Bohai Sea（4-6 m）. An investigation of sampling effects indicates that when using the 1°×1°grid dataset, although the combination of nine altimeters obviously enhanced the time and space coverage of sampling, the accuracy of statistical results, particularly extreme values obtained from the dataset, still suffered from undersampling problems because the time sampling percent in each 1°×1°grid cell was always less than33%.
文摘A 24-acre land at Aboso serves as the site where municipal solid waste from Tarkwa and its environs are openly dumped. Evaluation of the suitability of this existing landfill site for the construction of an engineered landfill was determined. Reconnaissance survey, structural mapping, determination of depth to groundwater, geotechnical site investigation as well as socio-economic indicators showed that the existing landfill site is not suitable for an engineered landfill construction. A multi-criteria GIS model was used to select an alternative suitable area for the construction of an engineered landfill. The multicriteria GIS modelling identified fourteen (14) suitable areas for the siting of landfill in the Tarkwa area. A site located in Domeabra was chosen due to its proximity to the neighbouring communities of Tarkwa, Nsuta and Aboso. The suitability of the proposed site in Domeabra was assessed using geotechnical and geophysical methods. The geotechnical methods included the testing of soil properties such as moisture content, particle size distribution, Atterberg limit, bulk density, specific gravity, and compactibility. The soils at Domeabra site are predominantly gravel and sand, well graded with gradual increase in clay content with depth and good moisture content (less than 30%). The gravel and sandy soils have good to excellent shear strength and work ability. The soils in Domeabra have suitable dry density (1.3 - 2.1 Mg/m3), bulk density (1.7 - 2.5 Mg/m3) and specific gravity (2.2 - 2.9) for landfill construction. The geophysical method involved the use of seismic refraction tomography. The geophysical survey showed that the site is made up of four layers namely the top soil (0.5 - 2 m), weathered material (5 - 15 m), saturated material (10 - 15 m) and fresh rock. The water table occurs at a depth of 12 to 15 m. The proposed area in Domeabra based on the geophysical and geotechnical investigations is suitable for the construction of engineered landfill.
文摘Songpan County is a poverty-stricken county in Tibetan areas of Sichuan Province,it belongs to a concentrated poverty-stricken area in China.Through summarizing the specific conditions of multi-level cooperation and complementary advantage poverty alleviation model in Songpan County,this paper analyzed the effect of this model.Through the analysis on the cooperative poverty alleviation model(eastern-western cooperation,provincial targeted assistance,county-wide"four-leading and four-assistance"inner-party assistance,social force"10000 enterprises helping 10000 villages",and"visiting every household and keeping every person busy"),it summarized the implementation and actual results of each level.In addition,it summarized the problems encountered in the implementation process of multi-level cooperation and complementary advantage poverty alleviation model and came up with recommendations.With the aid of this successful multi-level cooperation and complementary advantage poverty alleviation model,Songpan County has achieved a decisive victory in the fight against poverty.At the end of April 2019,the poverty rate in the whole region fell to 0.45%,and it successfully took off the poverty hat.This paper analyzed and refined the specific practice,main achievements,successful experience,implications and reference significance of multi-level cooperation and complementary advantage poverty alleviation model,to provide necessary references for innovation of poverty alleviation model in poverty-stricken Tibetan areas,or even other similar provinces and regions.
