Central Asia(CA)faces escalating threats from increasing temperature,glacier retreat,biodiversity loss,unsustainable water use,terminal lake shrinkage,and soil salinization,all of which challenge the balance between e...Central Asia(CA)faces escalating threats from increasing temperature,glacier retreat,biodiversity loss,unsustainable water use,terminal lake shrinkage,and soil salinization,all of which challenge the balance between ecological integrity and socio-economic development essential for achieving Sustainable Development Goals.However,a comprehensive understanding of priority areas from a multi-dimensional perspective is lacking,hindering effective conservation and development strategies.To address this,we developed a comprehensive assessment framework with a tailored indicator system,enabling a spatial evaluation of CA’s priority areas by integrating biodiversity,ecosystem services(ESs),and human activities.Combining zonation and geographical detectors,this approach facilitates spatial prioritization and examines ecological and socio-economic heterogeneity.Our findings reveal a heterogeneous distribution of priority areas across CA,with significant concentrations in eastern mountainous regions,river valleys,and oasis agricultural lands.We identified 184 key districts crucial for ecological and societal sustainability.Attribution analysis shows that natural factors like soil types,precipitation,and evapotranspiration significantly shape these areas,influencing human activities and the distribution of biodiversity and ESs.Multi-dimensional analysis indicates existing protected areas cover only 15%of the top 30%priority areas,revealing substantial conservation gaps.Additionally,a 38%overlap between ESs and human activities,along with 63.25%congruence in integrated areas,underscores significant human impacts on ecological systems and their dependency on ESs.Given CA’s limited resources,it is crucial to implement measures that strengthen conservation efforts,align ecological preservation with socio-economic demands,and enhance resource efficiency through sustainable integrated land and water resource management.展开更多
Vegetation restoration is a critical strategy for mitigating debris flow hazards by stabilizing slopes and modifying hydrological processes.Effective planning of priority restoration areas is particularly essential in...Vegetation restoration is a critical strategy for mitigating debris flow hazards by stabilizing slopes and modifying hydrological processes.Effective planning of priority restoration areas is particularly essential in dry-hot valley regions,where extreme hydrothermal conditions pose significant challenges.This study presents a novel framework that integrates microclimatic variables,such as temperature lapse rates,to enhance the spatial precision of revegetation efforts.The Reshuihe watershed in Southwest China,a representative dry-hot valley,was chosen as the study area.By analyzing hourly temperature and rainfall across an elevation gradient,a quadratic relationship between temperature lapse rates and weak rainfall events was identified,underscoring the role of microclimatic processes in influencing rainfall distribution and plant-available water.Rainfall peaks were observed when the temperature lapse rate was approximately 4.5°C/km.This relationship was incorporated into a cost-based restoration framework using the Marxan model,optimizing the spatial allocation of priority areas for revegetation.Results demonstrated that integrating microclimatic variables significantly improved the effectiveness of revegetation strategies,particularly for reducing debris flow risks.The lowest restoration costs were observed between elevations of 3200 m and 3300 m,where strong correlations between temperature lapse rates and rainfall were recorded.Priority restoration areas covered 41 km^(2),targeting zones with high debris flow risks.These findings highlight the value of incorporating microclimatic data into revegetation planning,enabling cost-effective and ecologically sustainable hazard mitigation in regions vulnerable to hydrological hazards.展开更多
We investigate the decision-making problem with a finite set of alternatives,in which the decision information takes the form of a fuzzy preference relation. We develop asimple and practical approach to obtaining the ...We investigate the decision-making problem with a finite set of alternatives,in which the decision information takes the form of a fuzzy preference relation. We develop asimple and practical approach to obtaining the priority vector of a fuzzy preference relation. Theprominent characteristic of the developed approach is that the priority vector can generally beobtained by a simple formula, which is derived from a quadratic programming model. We utilize theconsistency ratio to check the consistency of fuzzy preference relation. If the fuzzy preferencerelation is of unacceptable consistency, then we can return it to the decision maker to reconsiderstructuring a new fuzzy preference relation until the fuzzy preference relation with acceptableconsistency is obtained. We finally illustrate the priority approach by two numerical examples. Thenumerical results show that the developed approach is straightforward, effective, and can easily beperformed on a computer.展开更多
To satisfy the multiple priority requests from buses that arrive at different phases within a small time window, a multi-phase bus signal priority （MPBSP） strategy is developed. The proximity principle is brought fo...To satisfy the multiple priority requests from buses that arrive at different phases within a small time window, a multi-phase bus signal priority （MPBSP） strategy is developed. The proximity principle is brought forward to settle the conflicts among multiple priority requests and arrange the optimal priority sequence. To avoid over saturation of the intersection, a conditional MPBSP algorithm that adopts early green and green extension strategies is developed to give priority to the bus with the highest priority level when green time that each phase runs makes its saturation degree not larger than 0. 95. Finally, the algorithm is tested in the VISSIM environment and compared with the normal signal timing algorithm. Sensitive analysis of the number of priority phases, bus demand, and volume to capacity ratios are conducted to quantify their impacts on the benefits of the MPBSP. Results show that the MPBSP strategy can effectively reduce bus delays, and with the increase in the number of priority phases, the reduction range of bus delays also increases.展开更多
Abstract Satellite range scheduling with the priority constraint is one of the most important prob lems in the field of satellite operation. This paper proposes a station coding based genetic algorithm to solve this p...Abstract Satellite range scheduling with the priority constraint is one of the most important prob lems in the field of satellite operation. This paper proposes a station coding based genetic algorithm to solve this problem, which adopts a new chromosome encoding method that arranges tasks according to the ground station ID. The new encoding method contributes to reducing the complex ity in conflict checking and resolving, and helps to improve the ability to find optimal resolutions. Three different selection operators are designed to match the new encoding strategy, namely ran dom selection, greedy selection, and roulette selection. To demonstrate the benefits of the improved genetic algorithm, a basic genetic algorithm is designed in which two cross operators are presented, a singlepoint crossover and a multipoint crossover. For the purpose of algorithm test and analysis, a problemgenerating program is designed, which can simulate problems by modeling features encountered in realworld problems. Based on the problem generator, computational results and analysis are made and illustrated for the scheduling of multiple ground stations.展开更多
The cathode materials of spent lithium-ion batteries(LIBs)were recovered via reductive roasting,Na_(2)CO_(3) leaching,and ammonia leaching.The effects of roasting parameters,Na_(2)CO_(3) leaching parameters,and ammoni...The cathode materials of spent lithium-ion batteries(LIBs)were recovered via reductive roasting,Na_(2)CO_(3) leaching,and ammonia leaching.The effects of roasting parameters,Na_(2)CO_(3) leaching parameters,and ammonia leaching parameters on the leaching efficiencies of metals were explored.The results show that the mineral phase of spent LIBs is reconstructed during reductive roasting,and more than 99%of Li can be preferentially leached via Na_(2)CO_(3) leaching.Ni(99.7%)and Co(99.9%)can be leached via one-step ammonia leaching,and Mn cannot be leached.Thus,good leaching selectivity is achieved.The kinetic study shows that the leaching of Ni and Co conforms to chemical reaction control.展开更多
The priority of the filled patch play a key role in the exemplar-based image inpainting, and it should be determined firstly to optimize the process of image inpainting. A modified image inpainting algorithm is propos...The priority of the filled patch play a key role in the exemplar-based image inpainting, and it should be determined firstly to optimize the process of image inpainting. A modified image inpainting algorithm is proposed by weighted-priority based on the Criminisi algorithm. The improved algorithm demonstrates better relationship between the data term and the confidence term for the optimization of the priority than the classical Criminisi algorithm. By comparing the effect of the inpainted images with different structure, conclusion can be drawn that the optimal priority should be chosen properly for different images with different structures.展开更多
In the imaging observation system, imaging task scheduling is an important topic. Most scholars study the imaging task scheduling from the perspective of static priority, and only a few from the perspective of dynamic...In the imaging observation system, imaging task scheduling is an important topic. Most scholars study the imaging task scheduling from the perspective of static priority, and only a few from the perspective of dynamic priority. However,the priority of the imaging task is dynamic in actual engineering. To supplement the research on imaging observation, this paper proposes the task priority model, dynamic scheduling strategy and Heuristic algorithm. At first, this paper analyzes the relevant theoretical basis of imaging observation, decomposes the task priority into four parts, including target priority, imaging task priority, track, telemetry & control(TT&C)requirement priority and data transmission requirement priority, summarizes the attribute factors that affect the above four types of priority in detail, and designs the corresponding priority model. Then, this paper takes the emergency tasks scheduling problem as the background, proposes the dynamic scheduling strategy and heuristic algorithm. Finally, the task priority model,dynamic scheduling strategy and heuristic algorithm are verified by experiments.展开更多
In Southwest China,five Nature Reserves(NRs)(Mangkang,Baimaxueshan,Yunling,Habaxueshan,and Yunlongtianchi)play a key role in protecting the endemic and endangered Yunnan snub-nosed monkey(YSM)(Rhinopithecus bieti).How...In Southwest China,five Nature Reserves(NRs)(Mangkang,Baimaxueshan,Yunling,Habaxueshan,and Yunlongtianchi)play a key role in protecting the endemic and endangered Yunnan snub-nosed monkey(YSM)(Rhinopithecus bieti).However,increasing human activities threaten its habitats and corridors.We used a GIS-based Niche Model to delineate potential core habitats(PCHs)of the YSMs and a Linkage Mapper corridor simulation tool to restore potential connectivity corridors(PCCs),and defined five scenarios.A normalized importance value index(NIVI)was established to identify the protection priority areas(PPAs)for the YSMs for five scenarios.The results indicated that locations of the habitats and corridors were different in the five scenarios,thereby influencing the distribution of the PPAs and protection network of the YSMs.The NIVI value of Baimaxueshan nature reserve was 1 in the five scenarios,which implied the maximum importance.There were only 7 PCHs and 16 PCCs(with the longest average length of 223.13 km)which were mainly located around 5 NRs in scenario III.The protection network of the YSMs was composed of 16 PCHs,18 PCCs,and 5 NRs.Under each scenario,most of the PCHs and the PCCs were located in the south of the study area.The five NRs only covered 2 PPAs of the YSMs.We suggest that the southern part of the study area needs to be strictly protected and human activities should be limited.The area of the five NRs should be expanded to maximize protection of the YSMs in the future.展开更多
In 1957, the launch of the first artificial satellite ushered in a new era for modern space science. The past 50 years' developments in China's space science have witnessed many major missions, and substantial...In 1957, the launch of the first artificial satellite ushered in a new era for modern space science. The past 50 years' developments in China's space science have witnessed many major missions, and substantial progress has been achieved in space science study, exploration technology as well as experiment technology. Strategic Priority Program on Space Science was officially started in 2011. Through both self-developed space science missions and those with international cooperation,it is expected that the innovative breakthroughs will be realized, leapfrog development of related high-tech will be achieved to establish the important strategic status of space science in national development. To sum up, the implementation of the Strategic Priority Program on Space Science will definitely promote the rapid development of China's space science endeavor, making contributions to China's development and the progress of human civilization.展开更多
Some depression cells with heights lower than their surrounding cells may often be found in Grid-based digital elevation models (DEM) dataset due to sampling errors.The depression-filling algorithm presented by Planch...Some depression cells with heights lower than their surrounding cells may often be found in Grid-based digital elevation models (DEM) dataset due to sampling errors.The depression-filling algorithm presented by Planchon and Darboux works very quickly compared to other published methods.Despite its simplicity and deli-cacy,this algorithm remains difficult to understand due to its three complex subroutines and its recursive execution.Another fast algorithm is presented in this article.The main idea of this new algorithm is as follows:first,the DEM dataset is viewed as an island and the outer space as an ocean;when the ocean level increases,the DEM cells on the island's boundary will be inundated;when a cell is inundated for the first time,its elevation is increased to the ocean level at that moment;after the ocean has inun-dated the entire DEM,all of the depressions are filled.The depression-removing processing is performed using a priority queue.Theoretically,this new algorithm is a fast algorithm despite the fact that it runs more slowly than Planchon and Darboux's method.Its time-complexity in both the worst case and in an average case is O(8nlog 2 (m)),which is close to O(n).The running speed of this algorithm depends mainly on the insertion operation of the priority queue.As shown by the tests,the depres-sion-filling effects of this algorithm are correct and valid,and the overall time consumption of this algorithm is less than twice the time consumed by Planchon & Darboux's method for handling a DEM smaller than 2500×2500 cells.More importantly,this new algorithm is simpler and easier to understand than Planchon and Darboux's method This advantage allows the correct program code to be written quickly.展开更多
With the emerging diverse applications in data centers,the demands on quality of service in data centers also become diverse,such as high throughput of elephant flows and low latency of deadline-sensitive flows.Howeve...With the emerging diverse applications in data centers,the demands on quality of service in data centers also become diverse,such as high throughput of elephant flows and low latency of deadline-sensitive flows.However,traditional TCPs are ill-suited to such situations and always result in the inefficiency(e.g.missing the flow deadline,inevitable throughput collapse)of data transfers.This further degrades the user-perceived quality of service(QoS)in data centers.To reduce the flow completion time of mice and deadline-sensitive flows along with promoting the throughput of elephant flows,an efficient and deadline-aware priority-driven congestion control(PCC)protocol,which grants mice and deadline-sensitive flows the highest priority,is proposed in this paper.Specifically,PCC computes the priority of different flows according to the size of transmitted data,the remaining data volume,and the flows’deadline.Then PCC adjusts the congestion window according to the flow priority and the degree of network congestion.Furthermore,switches in data centers control the input/output of packets based on the flow priority and the queue length.Different from existing TCPs,to speed up the data transfers of mice and deadline-sensitive flows,PCC provides an effective method to compute and encode the flow priority explicitly.According to the flow priority,switches can manage packets efficiently and ensure the data transfers of high priority flows through a weighted priority scheduling with minor modification.The experimental results prove that PCC can improve the data transfer performance of mice and deadline-sensitive flows while guaranting the throughput of elephant flows.展开更多
Understanding yield potential, yield gap and the priority of management factors for reducing the yield gap in current intensive maize production is essential for meeting future food demand with the limited resources. ...Understanding yield potential, yield gap and the priority of management factors for reducing the yield gap in current intensive maize production is essential for meeting future food demand with the limited resources. In this study, we conducted field experiments using different planting modes, which were basic productivity(CK), farmer practice(FP), high yield and high efficiency(HH), and super high yield(SH), to estimate the yield gap. Different factorial experiments(fertilizer, planting density, hybrids, and irrigation) were also conducted to evaluate the priority of individual management factors for reducing the yield gap between the different planting modes. We found significant differences between the maize yields of different planting modes. The treatments of CK, FP, HH, and SH achieved 54.26, 58.76, 65.77, and 71.99% of the yield potential, respectively. The yield gaps between three pairs: CK and FP, FP and HH, and HH and SH, were 0.76, 1.23 and 0.85 t ha^(–1), respectively. By further analyzing the priority of management factors for reducing the yield gap between FP and HH, as well as HH and SH, we found that the priorities of the management factors(contribution rates) were plant density(13.29%)>fertilizer(11.95%)>hybrids(8.19%)>irrigation(4%) for FP to HH, and hybrids(8.94%)>plant density(4.84%)>fertilizer(1.91%) for HH to SH. Therefore, increasing the planting density of FP was the key factor for decreasing the yield gap between FP and HH, while choosing hybrids with density and lodging tolerance was the key factor for decreasing the yield gap between HH and SH.展开更多
The Strategic Priority Program(SPP)on Space Science,which is under the leadership of the Chinese Academy of Sciences(CAS),has established China’s space science satellite series from scratch.A number of major scientif...The Strategic Priority Program(SPP)on Space Science,which is under the leadership of the Chinese Academy of Sciences(CAS),has established China’s space science satellite series from scratch.A number of major scientific achievements have been made by the first phase of the Program(SPPⅠ),while SPPⅡhas been currently being implemented.The future development of space science needs urgent top-level planning and advanced layout to clarify the overall goal and investment portfolio from 2025 to 2030.We will briefly introduce the initiative and possible space science missions of SPPⅢ,including the preparatory work which already started in July 2021.Following the effective administrative tradition since SPPⅠ,National Space Science Center(NSSC,CAS)is responsible for the whole procedure,including soliciting,assessment,and implementation of SPPⅢ.Brief information on the 13 candidate missions will be described,including missions in the fields of astronomy&astrophysics,exoplanets,heliophysics and planetary&Earth science,respectively.展开更多
This paper considers an efficient priority service model with two-level-polling scheme which the message packets conform to the discrete-time Geom/G/1 queue with multiple vacations and bulk arrival. By the embedded Ma...This paper considers an efficient priority service model with two-level-polling scheme which the message packets conform to the discrete-time Geom/G/1 queue with multiple vacations and bulk arrival. By the embedded Markov chain theory and the probability generating function method, we set up the mathematics functions and give closed form expressions for obtaining the mean cyclic period （MCP）, the mean queue length （MQL） and the mean waiting time （MWT） characteristics, the analytical results are also verified through extensive computer simulations. The performance analysis reveals that this priority polling scheme can gives better efficiency as well as impartiality in terms of system characteristics, and it can be used for differentiating priority service to guarantee better QoS and system stability in design and improvement of MAC protocol.展开更多
The paper aims at the problem of multi-targets threat degree being hard to be evaluated accurately in complex air defense battlefield environments. Combined with multi-sensors information fusion and interval-valued in...The paper aims at the problem of multi-targets threat degree being hard to be evaluated accurately in complex air defense battlefield environments. Combined with multi-sensors information fusion and interval-valued intuitionistic fuzzy sets(IVIFS) theories, the target priority determination is studied. The score and accuracy functions of IVIFS are improved with thinking about the hesitating information in order to increase the rationality.Then, the influence factors of target priority and the nonlinear relationship between the influence factors and target priority are analyzed. Next, the algorithms for calculating the factor weights and sensor weights are given. Based on the theory of IVIFS and technique for order preference by similarity to an ideal solution(TOPSIS), two methods of target priority determination based on the IVIFS and TOPSIS are proposed. At last, an application example verifies the effectiveness and flexibility of the proposed algorithms.展开更多
In May 2018,the second phase of the Strategic Priority Program on Space Science(SPP II)was officially approved by the Chinese Academy of Sciences,in view of the significant scientific achievements of the first phase o...In May 2018,the second phase of the Strategic Priority Program on Space Science(SPP II)was officially approved by the Chinese Academy of Sciences,in view of the significant scientific achievements of the first phase of the Strategic Priority Program on Space Science(SPP I)which includes 4 space science missions:the Dark Matter Particle Explorer(DAMPE),ShiJian-10(SJ-10),Quantum Experiments at Space Scale(QUESS)and Hard X-ray Modulation Telescope(HXMT).Aiming to address fundamental scientific questions,SPP II focuses on two major themes:How the universe and life originate and evolve and What is the relationship between the solar system and human beings.In areas that Chinese scientists have advantages,new space science missions including Graviational wave high-energy Electromagnetic Counterpart All-sky Monitor(GECAM),the Advanced space-based Solar Observatory(ASO-S),the Einstein Probe(EP),and Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)have been approved in the framework of SPP II.This paper presents the research highlights of the SPP I,introduces the recent progress of SPP II,and puts forward the prospects for future development.展开更多
Food security,food safety and environmental protection are major livelihood issues in front of the Chinese people.The priorities of the three are different,and there is mutually dependent and contradictory relationshi...Food security,food safety and environmental protection are major livelihood issues in front of the Chinese people.The priorities of the three are different,and there is mutually dependent and contradictory relationship among them.Facing the triple pressures of food security,food safety,and environmental protection,this paper analyzes the priority of the three from the historical development,then further analyzes the interaction between food security,food safety and environmental protection and finally puts forward the healthy development of food security,food safety and environmental protection,and the proper settlement of the three problems.展开更多
Ecosystem services can be enhanced through ecological restoration,industrial structure adjustment,land-use optimization,and agricultural and forestry ecosystem transformation.The ecosystem services in hilly and mounta...Ecosystem services can be enhanced through ecological restoration,industrial structure adjustment,land-use optimization,and agricultural and forestry ecosystem transformation.The ecosystem services in hilly and mountainous areas of southern China are crucially needed to be enhanced since these regions are important ecological functional zones in China.However,due to its large area,it is not possible to simultaneously upgrade the ecosystem services for all areas,and therefore,priority areas need to be selected to individually upgrade the ecosystem service function.In this study,via an approach of combining remote sensing,geographic information system,and spatial statistics,we identify the priority areas that need to be upgraded based on the analysis of ecological sensitivity,importance of ecosystem service function,and decreased degree in ecosystem services.For five counties in hilly and mountainous areas of southern China,only less than 2% of the total area was identified as the first priority area;its land-use compositions were analyzed and recommendations on how to enhance ecosystem service were suggested.This approach overcomes the conflict and contradiction issues associated with identifying priority areas in previous studies and solves the problems of high cost or difficult implementation of priority areas.展开更多
基金funded by the Joint CAS-MPG Research Project(HZXM20225001MI)this research was also supported partly by the key program of National Natural Science Foundation of China(42230708)the Tianshan Talent Project of Xinjiang Uygur Autonomous Region,China(2022TSYCLJ0056).
文摘Central Asia(CA)faces escalating threats from increasing temperature,glacier retreat,biodiversity loss,unsustainable water use,terminal lake shrinkage,and soil salinization,all of which challenge the balance between ecological integrity and socio-economic development essential for achieving Sustainable Development Goals.However,a comprehensive understanding of priority areas from a multi-dimensional perspective is lacking,hindering effective conservation and development strategies.To address this,we developed a comprehensive assessment framework with a tailored indicator system,enabling a spatial evaluation of CA’s priority areas by integrating biodiversity,ecosystem services(ESs),and human activities.Combining zonation and geographical detectors,this approach facilitates spatial prioritization and examines ecological and socio-economic heterogeneity.Our findings reveal a heterogeneous distribution of priority areas across CA,with significant concentrations in eastern mountainous regions,river valleys,and oasis agricultural lands.We identified 184 key districts crucial for ecological and societal sustainability.Attribution analysis shows that natural factors like soil types,precipitation,and evapotranspiration significantly shape these areas,influencing human activities and the distribution of biodiversity and ESs.Multi-dimensional analysis indicates existing protected areas cover only 15%of the top 30%priority areas,revealing substantial conservation gaps.Additionally,a 38%overlap between ESs and human activities,along with 63.25%congruence in integrated areas,underscores significant human impacts on ecological systems and their dependency on ESs.Given CA’s limited resources,it is crucial to implement measures that strengthen conservation efforts,align ecological preservation with socio-economic demands,and enhance resource efficiency through sustainable integrated land and water resource management.
基金supported by the National Natural Science Foundation of China for General Program(42171118)the National Natural Science Foundation of China for Distinguished Young Scholars(41925030)the Special Funding Projects of Talents of Yunnan Province(YNWR-QNBJ-2020-099).
文摘Vegetation restoration is a critical strategy for mitigating debris flow hazards by stabilizing slopes and modifying hydrological processes.Effective planning of priority restoration areas is particularly essential in dry-hot valley regions,where extreme hydrothermal conditions pose significant challenges.This study presents a novel framework that integrates microclimatic variables,such as temperature lapse rates,to enhance the spatial precision of revegetation efforts.The Reshuihe watershed in Southwest China,a representative dry-hot valley,was chosen as the study area.By analyzing hourly temperature and rainfall across an elevation gradient,a quadratic relationship between temperature lapse rates and weak rainfall events was identified,underscoring the role of microclimatic processes in influencing rainfall distribution and plant-available water.Rainfall peaks were observed when the temperature lapse rate was approximately 4.5°C/km.This relationship was incorporated into a cost-based restoration framework using the Marxan model,optimizing the spatial allocation of priority areas for revegetation.Results demonstrated that integrating microclimatic variables significantly improved the effectiveness of revegetation strategies,particularly for reducing debris flow risks.The lowest restoration costs were observed between elevations of 3200 m and 3300 m,where strong correlations between temperature lapse rates and rainfall were recorded.Priority restoration areas covered 41 km^(2),targeting zones with high debris flow risks.These findings highlight the value of incorporating microclimatic data into revegetation planning,enabling cost-effective and ecologically sustainable hazard mitigation in regions vulnerable to hydrological hazards.
文摘We investigate the decision-making problem with a finite set of alternatives,in which the decision information takes the form of a fuzzy preference relation. We develop asimple and practical approach to obtaining the priority vector of a fuzzy preference relation. Theprominent characteristic of the developed approach is that the priority vector can generally beobtained by a simple formula, which is derived from a quadratic programming model. We utilize theconsistency ratio to check the consistency of fuzzy preference relation. If the fuzzy preferencerelation is of unacceptable consistency, then we can return it to the decision maker to reconsiderstructuring a new fuzzy preference relation until the fuzzy preference relation with acceptableconsistency is obtained. We finally illustrate the priority approach by two numerical examples. Thenumerical results show that the developed approach is straightforward, effective, and can easily beperformed on a computer.
基金The National High Technology Research and Development Program of China(863 Program)(No.2011AA110304)the National Natural Science Foundation of China(No.50908100)Graduate Innovation Fund of Jilin University(No.20111044)
文摘To satisfy the multiple priority requests from buses that arrive at different phases within a small time window, a multi-phase bus signal priority （MPBSP） strategy is developed. The proximity principle is brought forward to settle the conflicts among multiple priority requests and arrange the optimal priority sequence. To avoid over saturation of the intersection, a conditional MPBSP algorithm that adopts early green and green extension strategies is developed to give priority to the bus with the highest priority level when green time that each phase runs makes its saturation degree not larger than 0. 95. Finally, the algorithm is tested in the VISSIM environment and compared with the normal signal timing algorithm. Sensitive analysis of the number of priority phases, bus demand, and volume to capacity ratios are conducted to quantify their impacts on the benefits of the MPBSP. Results show that the MPBSP strategy can effectively reduce bus delays, and with the increase in the number of priority phases, the reduction range of bus delays also increases.
文摘Abstract Satellite range scheduling with the priority constraint is one of the most important prob lems in the field of satellite operation. This paper proposes a station coding based genetic algorithm to solve this problem, which adopts a new chromosome encoding method that arranges tasks according to the ground station ID. The new encoding method contributes to reducing the complex ity in conflict checking and resolving, and helps to improve the ability to find optimal resolutions. Three different selection operators are designed to match the new encoding strategy, namely ran dom selection, greedy selection, and roulette selection. To demonstrate the benefits of the improved genetic algorithm, a basic genetic algorithm is designed in which two cross operators are presented, a singlepoint crossover and a multipoint crossover. For the purpose of algorithm test and analysis, a problemgenerating program is designed, which can simulate problems by modeling features encountered in realworld problems. Based on the problem generator, computational results and analysis are made and illustrated for the scheduling of multiple ground stations.
基金the financial support from the Focus on Research and Development Plan in Shandong Province,China(No.2017GSF16102)。
文摘The cathode materials of spent lithium-ion batteries(LIBs)were recovered via reductive roasting,Na_(2)CO_(3) leaching,and ammonia leaching.The effects of roasting parameters,Na_(2)CO_(3) leaching parameters,and ammonia leaching parameters on the leaching efficiencies of metals were explored.The results show that the mineral phase of spent LIBs is reconstructed during reductive roasting,and more than 99%of Li can be preferentially leached via Na_(2)CO_(3) leaching.Ni(99.7%)and Co(99.9%)can be leached via one-step ammonia leaching,and Mn cannot be leached.Thus,good leaching selectivity is achieved.The kinetic study shows that the leaching of Ni and Co conforms to chemical reaction control.
基金Supported by the National Natural Science Foundation of China (No. 60972106)Postdoctoral Science Foundation (No. 20090450750)the Science Foundation of Tianjin(No. 11JCYBJC00900)
文摘The priority of the filled patch play a key role in the exemplar-based image inpainting, and it should be determined firstly to optimize the process of image inpainting. A modified image inpainting algorithm is proposed by weighted-priority based on the Criminisi algorithm. The improved algorithm demonstrates better relationship between the data term and the confidence term for the optimization of the priority than the classical Criminisi algorithm. By comparing the effect of the inpainted images with different structure, conclusion can be drawn that the optimal priority should be chosen properly for different images with different structures.
基金supported by the National Natural Science Foundation of China(61773120,61473301,71501180,71501179,61603400)。
文摘In the imaging observation system, imaging task scheduling is an important topic. Most scholars study the imaging task scheduling from the perspective of static priority, and only a few from the perspective of dynamic priority. However,the priority of the imaging task is dynamic in actual engineering. To supplement the research on imaging observation, this paper proposes the task priority model, dynamic scheduling strategy and Heuristic algorithm. At first, this paper analyzes the relevant theoretical basis of imaging observation, decomposes the task priority into four parts, including target priority, imaging task priority, track, telemetry & control(TT&C)requirement priority and data transmission requirement priority, summarizes the attribute factors that affect the above four types of priority in detail, and designs the corresponding priority model. Then, this paper takes the emergency tasks scheduling problem as the background, proposes the dynamic scheduling strategy and heuristic algorithm. Finally, the task priority model,dynamic scheduling strategy and heuristic algorithm are verified by experiments.
基金National Key Research and Development Program of China,No.2016YFC0502102
文摘In Southwest China,five Nature Reserves(NRs)(Mangkang,Baimaxueshan,Yunling,Habaxueshan,and Yunlongtianchi)play a key role in protecting the endemic and endangered Yunnan snub-nosed monkey(YSM)(Rhinopithecus bieti).However,increasing human activities threaten its habitats and corridors.We used a GIS-based Niche Model to delineate potential core habitats(PCHs)of the YSMs and a Linkage Mapper corridor simulation tool to restore potential connectivity corridors(PCCs),and defined five scenarios.A normalized importance value index(NIVI)was established to identify the protection priority areas(PPAs)for the YSMs for five scenarios.The results indicated that locations of the habitats and corridors were different in the five scenarios,thereby influencing the distribution of the PPAs and protection network of the YSMs.The NIVI value of Baimaxueshan nature reserve was 1 in the five scenarios,which implied the maximum importance.There were only 7 PCHs and 16 PCCs(with the longest average length of 223.13 km)which were mainly located around 5 NRs in scenario III.The protection network of the YSMs was composed of 16 PCHs,18 PCCs,and 5 NRs.Under each scenario,most of the PCHs and the PCCs were located in the south of the study area.The five NRs only covered 2 PPAs of the YSMs.We suggest that the southern part of the study area needs to be strictly protected and human activities should be limited.The area of the five NRs should be expanded to maximize protection of the YSMs in the future.
文摘In 1957, the launch of the first artificial satellite ushered in a new era for modern space science. The past 50 years' developments in China's space science have witnessed many major missions, and substantial progress has been achieved in space science study, exploration technology as well as experiment technology. Strategic Priority Program on Space Science was officially started in 2011. Through both self-developed space science missions and those with international cooperation,it is expected that the innovative breakthroughs will be realized, leapfrog development of related high-tech will be achieved to establish the important strategic status of space science in national development. To sum up, the implementation of the Strategic Priority Program on Space Science will definitely promote the rapid development of China's space science endeavor, making contributions to China's development and the progress of human civilization.
基金financially supported by the National Basic Research Program of China (Grant No.2006CB400502)the Promotion of 100 Young Talent Scientist Project of the Chinese Acad-emy of Sciences (8-057493)the Special Meteorology Project(GYHY(QX)2007-6-1)
文摘Some depression cells with heights lower than their surrounding cells may often be found in Grid-based digital elevation models (DEM) dataset due to sampling errors.The depression-filling algorithm presented by Planchon and Darboux works very quickly compared to other published methods.Despite its simplicity and deli-cacy,this algorithm remains difficult to understand due to its three complex subroutines and its recursive execution.Another fast algorithm is presented in this article.The main idea of this new algorithm is as follows:first,the DEM dataset is viewed as an island and the outer space as an ocean;when the ocean level increases,the DEM cells on the island's boundary will be inundated;when a cell is inundated for the first time,its elevation is increased to the ocean level at that moment;after the ocean has inun-dated the entire DEM,all of the depressions are filled.The depression-removing processing is performed using a priority queue.Theoretically,this new algorithm is a fast algorithm despite the fact that it runs more slowly than Planchon and Darboux's method.Its time-complexity in both the worst case and in an average case is O(8nlog 2 (m)),which is close to O(n).The running speed of this algorithm depends mainly on the insertion operation of the priority queue.As shown by the tests,the depres-sion-filling effects of this algorithm are correct and valid,and the overall time consumption of this algorithm is less than twice the time consumed by Planchon & Darboux's method for handling a DEM smaller than 2500×2500 cells.More importantly,this new algorithm is simpler and easier to understand than Planchon and Darboux's method This advantage allows the correct program code to be written quickly.
基金supported part by the National Natural Science Foundation of China(61601252,61801254)Public Technology Projects of Zhejiang Province(LG-G18F020007)+1 种基金Zhejiang Provincial Natural Science Foundation of China(LY20F020008,LY18F020011,LY20F010004)K.C.Wong Magna Fund in Ningbo University。
文摘With the emerging diverse applications in data centers,the demands on quality of service in data centers also become diverse,such as high throughput of elephant flows and low latency of deadline-sensitive flows.However,traditional TCPs are ill-suited to such situations and always result in the inefficiency(e.g.missing the flow deadline,inevitable throughput collapse)of data transfers.This further degrades the user-perceived quality of service(QoS)in data centers.To reduce the flow completion time of mice and deadline-sensitive flows along with promoting the throughput of elephant flows,an efficient and deadline-aware priority-driven congestion control(PCC)protocol,which grants mice and deadline-sensitive flows the highest priority,is proposed in this paper.Specifically,PCC computes the priority of different flows according to the size of transmitted data,the remaining data volume,and the flows’deadline.Then PCC adjusts the congestion window according to the flow priority and the degree of network congestion.Furthermore,switches in data centers control the input/output of packets based on the flow priority and the queue length.Different from existing TCPs,to speed up the data transfers of mice and deadline-sensitive flows,PCC provides an effective method to compute and encode the flow priority explicitly.According to the flow priority,switches can manage packets efficiently and ensure the data transfers of high priority flows through a weighted priority scheduling with minor modification.The experimental results prove that PCC can improve the data transfer performance of mice and deadline-sensitive flows while guaranting the throughput of elephant flows.
基金the National Key Research and Development Program of China(2016YFD0300106)the National Natural Science Foundation of China(31601247)for their financial support。
文摘Understanding yield potential, yield gap and the priority of management factors for reducing the yield gap in current intensive maize production is essential for meeting future food demand with the limited resources. In this study, we conducted field experiments using different planting modes, which were basic productivity(CK), farmer practice(FP), high yield and high efficiency(HH), and super high yield(SH), to estimate the yield gap. Different factorial experiments(fertilizer, planting density, hybrids, and irrigation) were also conducted to evaluate the priority of individual management factors for reducing the yield gap between the different planting modes. We found significant differences between the maize yields of different planting modes. The treatments of CK, FP, HH, and SH achieved 54.26, 58.76, 65.77, and 71.99% of the yield potential, respectively. The yield gaps between three pairs: CK and FP, FP and HH, and HH and SH, were 0.76, 1.23 and 0.85 t ha^(–1), respectively. By further analyzing the priority of management factors for reducing the yield gap between FP and HH, as well as HH and SH, we found that the priorities of the management factors(contribution rates) were plant density(13.29%)>fertilizer(11.95%)>hybrids(8.19%)>irrigation(4%) for FP to HH, and hybrids(8.94%)>plant density(4.84%)>fertilizer(1.91%) for HH to SH. Therefore, increasing the planting density of FP was the key factor for decreasing the yield gap between FP and HH, while choosing hybrids with density and lodging tolerance was the key factor for decreasing the yield gap between HH and SH.
基金Supported by Strategic Priority Research Program of the Chinese Academy of Sciences(XDA15060102)。
文摘The Strategic Priority Program(SPP)on Space Science,which is under the leadership of the Chinese Academy of Sciences(CAS),has established China’s space science satellite series from scratch.A number of major scientific achievements have been made by the first phase of the Program(SPPⅠ),while SPPⅡhas been currently being implemented.The future development of space science needs urgent top-level planning and advanced layout to clarify the overall goal and investment portfolio from 2025 to 2030.We will briefly introduce the initiative and possible space science missions of SPPⅢ,including the preparatory work which already started in July 2021.Following the effective administrative tradition since SPPⅠ,National Space Science Center(NSSC,CAS)is responsible for the whole procedure,including soliciting,assessment,and implementation of SPPⅢ.Brief information on the 13 candidate missions will be described,including missions in the fields of astronomy&astrophysics,exoplanets,heliophysics and planetary&Earth science,respectively.
基金Supported by the National Natural Science Foundation of China （No. 69862001, F0424104, 60362001 and 61072079）.
文摘This paper considers an efficient priority service model with two-level-polling scheme which the message packets conform to the discrete-time Geom/G/1 queue with multiple vacations and bulk arrival. By the embedded Markov chain theory and the probability generating function method, we set up the mathematics functions and give closed form expressions for obtaining the mean cyclic period （MCP）, the mean queue length （MQL） and the mean waiting time （MWT） characteristics, the analytical results are also verified through extensive computer simulations. The performance analysis reveals that this priority polling scheme can gives better efficiency as well as impartiality in terms of system characteristics, and it can be used for differentiating priority service to guarantee better QoS and system stability in design and improvement of MAC protocol.
基金the National Defense Pre-Research Foundation of China(No.9140A27020211JB34)
文摘The paper aims at the problem of multi-targets threat degree being hard to be evaluated accurately in complex air defense battlefield environments. Combined with multi-sensors information fusion and interval-valued intuitionistic fuzzy sets(IVIFS) theories, the target priority determination is studied. The score and accuracy functions of IVIFS are improved with thinking about the hesitating information in order to increase the rationality.Then, the influence factors of target priority and the nonlinear relationship between the influence factors and target priority are analyzed. Next, the algorithms for calculating the factor weights and sensor weights are given. Based on the theory of IVIFS and technique for order preference by similarity to an ideal solution(TOPSIS), two methods of target priority determination based on the IVIFS and TOPSIS are proposed. At last, an application example verifies the effectiveness and flexibility of the proposed algorithms.
基金Supported by the Strategic Priority Program on Space Science of the Chinese Academy of Sciences(XDA15000000)。
文摘In May 2018,the second phase of the Strategic Priority Program on Space Science(SPP II)was officially approved by the Chinese Academy of Sciences,in view of the significant scientific achievements of the first phase of the Strategic Priority Program on Space Science(SPP I)which includes 4 space science missions:the Dark Matter Particle Explorer(DAMPE),ShiJian-10(SJ-10),Quantum Experiments at Space Scale(QUESS)and Hard X-ray Modulation Telescope(HXMT).Aiming to address fundamental scientific questions,SPP II focuses on two major themes:How the universe and life originate and evolve and What is the relationship between the solar system and human beings.In areas that Chinese scientists have advantages,new space science missions including Graviational wave high-energy Electromagnetic Counterpart All-sky Monitor(GECAM),the Advanced space-based Solar Observatory(ASO-S),the Einstein Probe(EP),and Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)have been approved in the framework of SPP II.This paper presents the research highlights of the SPP I,introduces the recent progress of SPP II,and puts forward the prospects for future development.
基金the research fruits of"A Study of the Public Interest Litigation and Security Mechanism for the Quality and Safety of Agricultural Products"(15BGL135),a general project granted by the National Social Sciences Planning Office.
文摘Food security,food safety and environmental protection are major livelihood issues in front of the Chinese people.The priorities of the three are different,and there is mutually dependent and contradictory relationship among them.Facing the triple pressures of food security,food safety,and environmental protection,this paper analyzes the priority of the three from the historical development,then further analyzes the interaction between food security,food safety and environmental protection and finally puts forward the healthy development of food security,food safety and environmental protection,and the proper settlement of the three problems.
基金financially supported by the National Key Research and Development Program of China(2017YFC0505606)the Top Discipline and First-class University Construction Project(ydzxxk201618)of Minzu University of China。
文摘Ecosystem services can be enhanced through ecological restoration,industrial structure adjustment,land-use optimization,and agricultural and forestry ecosystem transformation.The ecosystem services in hilly and mountainous areas of southern China are crucially needed to be enhanced since these regions are important ecological functional zones in China.However,due to its large area,it is not possible to simultaneously upgrade the ecosystem services for all areas,and therefore,priority areas need to be selected to individually upgrade the ecosystem service function.In this study,via an approach of combining remote sensing,geographic information system,and spatial statistics,we identify the priority areas that need to be upgraded based on the analysis of ecological sensitivity,importance of ecosystem service function,and decreased degree in ecosystem services.For five counties in hilly and mountainous areas of southern China,only less than 2% of the total area was identified as the first priority area;its land-use compositions were analyzed and recommendations on how to enhance ecosystem service were suggested.This approach overcomes the conflict and contradiction issues associated with identifying priority areas in previous studies and solves the problems of high cost or difficult implementation of priority areas.
