期刊文献+
共找到139篇文章
< 1 2 7 >
每页显示 20 50 100
汉魏“浮华交会”释义
1
作者 夏毅辉 《许昌学院学报》 CAS 2007年第1期31-36,共6页
“浮华”之初义,源自中国古代“重本抑末”的经济思维,后来扩大到社会认识的各个领域,演绎成为一种社会政治语言。“交会”一词,本源于先秦士人的“游宦”、“游仕”;西汉时儒学兴起,士人求师问学、周游四方,此后演绎为结党权门,交援求... “浮华”之初义,源自中国古代“重本抑末”的经济思维,后来扩大到社会认识的各个领域,演绎成为一种社会政治语言。“交会”一词,本源于先秦士人的“游宦”、“游仕”;西汉时儒学兴起,士人求师问学、周游四方,此后演绎为结党权门,交援求名之义。两者皆因有悖于经学传统与名教政治,而为绝对皇权所深恶,最后成为汉魏时期士风变化与思想演进之标识。 展开更多
关键词 汉魏之际 “浮华” “交会” 原始义
下载PDF
The influence of different types of satisfaction on loyalty on C2C online shopping platform:From the perspective of sellers and the platform
2
作者 Yanan Lu Qian Huang Yuting Wang 《中国科学技术大学学报》 CAS CSCD 北大核心 2024年第5期36-48,I0007,共14页
With the rise and development of major types of platforms,the competition for resources has become extremely fierce,and the market share of C2C platforms has been seriously threatened by the loss of resources.Therefor... With the rise and development of major types of platforms,the competition for resources has become extremely fierce,and the market share of C2C platforms has been seriously threatened by the loss of resources.Therefore,building and maintaining buyers’satisfaction and loyalty to C2C platforms is critical to the survival and sustainability of C2C platforms in China.However,the current knowledge on how platform satisfaction and loyalty are constructed in the C2C e-commerce environment is incomplete.In this study,seller-based satisfaction and platform-based satisfaction are constructed separately.We further distinguish seller-based transaction satisfaction into economic and social satisfaction and explore their antecedents and consequences.To test our research hypotheses,we conduct a survey and collect data from a real online market(Taobao website).The results show that seller-based transaction satisfaction positively affects platform-based overall satisfaction and loyalty,and that perceived product quality,perceived assurance,and perceived price fairness all have a significant effect on economic satisfaction,whereas perceived relationship quality and perceived empathy significantly influence social satisfaction.These findings help us understand the literature related to customer satisfaction in the context of C2C in China and provide inspiration for online sellers and platforms. 展开更多
关键词 transaction-specific satisfaction social and economic satisfaction various antecedents of satisfaction overall satisfaction C2C online shopping platform
下载PDF
Fluid sensitivity study of elastic parameters in lowmedium porosity and permeability reservoir rocks 被引量:2
3
作者 裴发根 邹长春 +3 位作者 何涛 史謌 仇根根 任科英 《Applied Geophysics》 SCIE CSCD 2010年第1期1-9,98,共10页
In this article,based on the acoustic measurements of core samples obtained from the low to medium porosity and permeability reservoirs in the WXS Depression,the densities and P and S wave velocities of these core sam... In this article,based on the acoustic measurements of core samples obtained from the low to medium porosity and permeability reservoirs in the WXS Depression,the densities and P and S wave velocities of these core samples were obtained.Then based on these data,a series of elastic parameters were computed.From the basic theory and previous pore fluid research results,we derived a new fluid identification factor(F).Using the relative variations,Ag/w and Ao/w,of the elastic parameters between gas and water saturated samples and between oil and water saturated samples,λρ,σHSFIF,Kρ,λρ-2μρ,and F as quantitative indicators,we evaluate the sensitivity of the different fluid identification factors to identify reservoir fluids and validate the effects by crossplots.These confirm that the new fluid identification factor(F) is more sensitive for distinguishing oil and water than the traditional method and is more favorable for fliud identification in low to medium porosity and permeability reservoirs. 展开更多
关键词 elastic parameters pore fluid fluid identification factor wave impedance crossplot validation
下载PDF
Modeling customer satisfaction for bus rapid transit in Changzhou, China 被引量:4
4
作者 霍月英 李文权 陈茜 《Journal of Southeast University(English Edition)》 EI CAS 2016年第2期233-239,共7页
This paper aims to develop a customer satisfaction model for bus rapid transit (BRT). Both the socio-economic and travel characteristics of passengers were considered to be independent variables. Changzhou BRT was t... This paper aims to develop a customer satisfaction model for bus rapid transit (BRT). Both the socio-economic and travel characteristics of passengers were considered to be independent variables. Changzhou BRT was taken as an example and on which on-board surveys were conducted to collect data. Ordinal logistic regression (OLR) was used as the modeling approach. The general OLR-based procedure for modeling customer satisfaction is proposed and based on which the customer satisfaction model of Changzhou BRT is developed. Some important findings are concluded: Waiting sub-journey affects customer satisfaction the most, riding sub- journey comes second and arriving station sub-journey has relatively fewer effects. The availability of shelter and benches at stations imposes heavy influence on customer satisfaction. Passengers' socio-economic characteristics have heavy impact on customer satisfaction. 展开更多
关键词 customer satisfaction bus rapid transit MODELING socio-economic characteristics trip characteristics
下载PDF
APPLICATION OF VELOCITY GAIN GUIDANCE TO FAR-DISTANCE RENDEZVOUS
5
作者 刘鲁华 汤国建 +1 位作者 郑伟 余梦伦 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2006年第3期168-172,共5页
Using impulse hypothesis to solve far-distance rendezvous is difficult to be realized in a real project and the guidance accuracy cannot be controlled. A two-maneuver guidance law is designed for the two-impulse rende... Using impulse hypothesis to solve far-distance rendezvous is difficult to be realized in a real project and the guidance accuracy cannot be controlled. A two-maneuver guidance law is designed for the two-impulse rendezvous problem. The velocity gain guidance is applied to the first maneuver and the time-cut-off law is applied to the second one. Theoretical and simulation results show that the plan is credible. Accuracy requirements in fardistance rendezvous and in transform to close-in rendezous can be met. 展开更多
关键词 velocity gain guidance RENDEZVOUS guidance accuracy C-W equation
下载PDF
Effects of temperature and strain rate on critical damage value of AZ80 magnesium alloy 被引量:4
6
作者 夏玉峰 权国政 周杰 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第B07期580-583,共4页
A series of AZ80 billets were compressed with 60%height reduction on hot process simulator at 250,300,350,400℃ under strain rates of 0.01,0.1,1 and 10 s- 1.In order to predict the occurrence of surface fracture,the v... A series of AZ80 billets were compressed with 60%height reduction on hot process simulator at 250,300,350,400℃ under strain rates of 0.01,0.1,1 and 10 s- 1.In order to predict the occurrence of surface fracture,the values of the Cockcroft-Latham equation were calculated by the corresponding finite element numerical algorithm developed.A concept about damage incremental ratio in plastic deformation was defined as the ratio of damage increment at one step to the accumulated value.A method of finding the intersection of incremental ratio varying curve and simulation step axis was brought forward to make the fracture step certain. Then,the effects of temperature and strain rate on critical damage value were achieved.The results show that the critical damage value is not a constant but changes in a range of 0.021 8-0.378 0.It decreases significantly with the increase of strain rate at a certain temperature.While under a certain strain rate,the critical damage value has little change with the increase of temperature. 展开更多
关键词 AZ80 magnesium alloy critical damage value COMPACTION finite element analysis
下载PDF
Coalbody structure classification method based on dual-lateral and RXO crossplot analysis 被引量:6
7
作者 Qiang CHEN Hui-Fang YAO +1 位作者 Suo-Liang CHANG Jun LIU 《Journal of Coal Science & Engineering(China)》 2013年第4期522-529,共8页
According to the positive correlation of coal ash content and natural gamma, using a new coal core reposition method, which is ordered by global and local extreme, coal samples from medium-thickness seam are reasonabl... According to the positive correlation of coal ash content and natural gamma, using a new coal core reposition method, which is ordered by global and local extreme, coal samples from medium-thickness seam are reasonably located. Inte- grated the data of coal macrostructure characteristics, coal petrography analysis and coal gas production test, it studies the rela- tionship between coalbody structure and amplitude variation of different well logging data, and the tectonic coal recognition method with well logging data in fresh-water mud invasion. The results show that: the anomalous response of natural gamma ray, neutron, density and apparent resistivity does not reflect the coalbody structure type. In fresh-water drilling mud invasion, using the crossplot technique of dual-lateral, RXO resistivity response and the coalbody structure can classify granulated coal accurately; the proposed method is of good practicability and high reliability. 展开更多
关键词 coalbody structure mud filtrate invasion coal core depth-correction dual-lateral and RXO resistivity permeability
下载PDF
Non-linear Dynamics Method to Angles-Only Navigation for Non-cooperative Rendezvous of Spacecraft 被引量:2
8
作者 DU Ronghua LIAO Wenhe ZHANG Xiang 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2022年第4期400-414,共15页
Aiming at the problem of relative navigation for non-cooperative rendezvous of spacecraft,this paper proposes a new angles-only navigation architecture using non-linear dynamics method. This method does not solve the ... Aiming at the problem of relative navigation for non-cooperative rendezvous of spacecraft,this paper proposes a new angles-only navigation architecture using non-linear dynamics method. This method does not solve the problem of poor observability of angles-only navigation through orbital or attitude maneuvering,but improves the observability of angles-only navigation through capturing the non-linearity of the system in the evolution of relative motion. First,three relative dynamics models and their corresponding line-of-sight(LoS)measurement equations are introduced,including the rectilinear state relative dynamics model,the curvilinear state relative dynamics model,and the relative orbital elements(ROE)state relative dynamics model. Then,an observability analysis theory based on the Gramian matrix is introduced to determine which relative dynamics model could maximize the observability of angles-only navigation. Next,an adaptive extended Kalman filtering scheme is proposed to solve the problem that the angles-only navigation filter using the non-linear dynamics method is sensitive to measurement noises. Finally,the performances of the proposed angles-only navigation architecture are tested by means of numerical simulations,which demonstrates that the angles-only navigation filtering scheme without orbital or attitude maneuvering is completely feasible through improving the modeling of the relative dynamics and LoS measurement equations. 展开更多
关键词 angles-only navigation non-linear dynamics observability analysis non-cooperative rendezvous adaptive Kalman filter
下载PDF
Effects of sudden change in wind loads on running performance of trains on a highway-railway one-story bridge in crosswinds 被引量:1
9
作者 HAN Yan LIU Ye +2 位作者 CAI Chun-sheng HU Peng HE Xu-hui 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第8期2621-2638,共18页
To investigate the effects of sudden change in wind loads on the running performance of trains on the bridge in crosswinds,a highway-railway one-story bridge was taken as the research object.Aerodynamic coefficients o... To investigate the effects of sudden change in wind loads on the running performance of trains on the bridge in crosswinds,a highway-railway one-story bridge was taken as the research object.Aerodynamic coefficients of the train and the bridge were measured in a series of train-bridge system segment models through wind tunnel tests when two trains passed each other on the bridge and when a train entered and left the wind barrier section of the bridge.Based on the improved SIMPACK and ANSYS rigid-flexible coupling simulation method,a wind-double train-track-bridge system coupled vibration model was established.The dynamic responses of the train were analyzed under the effects of sudden change in wind loads caused by two trains passing each other and a train entering and leaving the wind barrier section of the bridge.The results show that the effects of sudden wind load change caused by the trains passing each other had less effects on the running safety of the leeward-side train than the wind shielding effect caused by the windward-side train in the wind speed range of 10−25 m/s.With the decrease in the porosity of wind barriers,the effects of the sudden wind load change played an increasingly important role in the running safety and comfort of the train.With the increase in wind speed,the lateral response of the train increased obviously because of the effects of sudden wind load change,which affects both the lateral running stability and the comfort of the train. 展开更多
关键词 wind-train-track-bridge system two trains passing each other wind barrier sudden change in wind load dynamic response
下载PDF
Individual Variation in Growth in Sea Cucumber Apostichopus japonicus(Selenck) Housed Individually 被引量:5
10
作者 LIANG Miao DONG Shuanglin GAO Qinfeng WANG Fang TIAN Xiangli 《Journal of Ocean University of China》 SCIE CAS 2010年第3期291-296,共6页
The exceptionally large individual growth variation has been previously recognized in several sea cucumber cohorts. However, there is a lack of information regarding the mechanism of such individual differences. In th... The exceptionally large individual growth variation has been previously recognized in several sea cucumber cohorts. However, there is a lack of information regarding the mechanism of such individual differences. In this study, the sea cucumber Apostichopusjaponicus (Selenka) was reared individually in order to eliminate possible effects of social interaction, stocking density, etc. The results showed that there were substantial differences in growth among the sea cucumber individuals during the 100-day experiment. The special growth rate of the sea cucumber individuals differed by up to three folds (from 0.40% to 1.01%), and the coefficient of variation in body weight increased from 12.04% to 40.51%. The final wet body weight, food intake and food conversion efficiency for each sea cucumber were generally positively correlated with their initial wet body weight (P〈0.05). Energy budget of the animals showed that the food energy spent on respiration was much greater (about four folds) but energy deposited for growth was much less for (initially) smaller than for larger A. japonicus. The present result implies that there are obvious genetic differences among the sea cucumber individuals, largely accounting for the individual growth variation of the cohort sea cucumber. These results will provide some basic data for promoting selective breeding and fanning of the sea cucumber. 展开更多
关键词 sea cucumber Apostichopusjaponicus GROWTH coefficient of variation INDIVIDUAL
下载PDF
ReTweeting Analysis and Prediction in Microblogs: An Epidemic Inspired Approach 被引量:11
11
作者 王昊 李义萍 +1 位作者 冯卓楠 冯铃 《China Communications》 SCIE CSCD 2013年第3期13-24,共12页
Microblogs currently play an important role in social communication. Hot topics currently being tweeted can quickly become popular within a very short time as a result of retweeting. Gaining an understanding of the re... Microblogs currently play an important role in social communication. Hot topics currently being tweeted can quickly become popular within a very short time as a result of retweeting. Gaining an understanding of the retweeting behavior is desirable for a number of tasks such as topic detection, personalized message recommendation, and fake information monitoring and prevention. Interestingly, the propagation of tweets bears some similarity to the spread of infectious diseases. We present a method to model the tweets' spread behavior in microblogs based on the classic Susceptible-Infectious-Susceptible (SIS) epidemic model that was developed in the medical field for the spread of infectious diseases. On the basis of this model, future retweeting trends can be predicted. Our experiments on data obtained from the Chinese micro-blogging website Sina Weibo show that the proposed model has lower predictive error compared to the four commonly used prediction methods. 展开更多
关键词 tweets retweeting PREDICTION SIS epidemic model
下载PDF
A New Multi-Resource Allocation Mechanism: A Tradeoff between Fairness and Efficiency in Cloud Computing 被引量:2
12
作者 Lihua Zhao Minghui Du Lin Chen 《China Communications》 SCIE CSCD 2018年第3期57-77,共21页
This paper addresses multi-resource fair allocation: a fundamental research topic in cloud computing. To improve resource utilization under well-studied fairness constraints, we propose a new allocation mechanism call... This paper addresses multi-resource fair allocation: a fundamental research topic in cloud computing. To improve resource utilization under well-studied fairness constraints, we propose a new allocation mechanism called Dominant Resource with Bottlenecked Fairness(DRBF), which generalizes Bottleneck-aware Allocation(BAA) to the settings of Dominant Resource Fairness(DRF). We classify users into different queues by their dominant resources. The goals are to ensure that users in the same queue receive allocations in proportion to their fair shares while users in different queues receive allocations that maximize resource utilization subject to well-studied fairness properties such as those in DRF. Under DRBF, no user 1) is worse off sharing resources than dividing resources equally among all users; 2) prefers the allocation of another user; 3) can improve their own allocation without reducing other users' allocations; and(4) can benefit by misreporting their resource demands. Experiments demonstrate that the proposed allocation policy performs better in terms of high resource utilization than does DRF. 展开更多
关键词 multi-resource fairness allocation cloud computing resource utilization
下载PDF
Vigilance behavior of Pyrenean chamois Rupicapra pyrenaica pyrenaica:Effect of sex and position in the herd 被引量:2
13
作者 Antoni DALMAU Alfred FERRET Xavier MANTECA 《Current Zoology》 SCIE CAS CSCD 北大核心 2010年第2期232-237,共6页
The Pyrenean chamois Rupicapra pyrenaica pyrenaica is a mountain-dwelling ungulate with an extensive presence in open areas. Optimal group size results from the trade off between advantages (a reduction in the risk o... The Pyrenean chamois Rupicapra pyrenaica pyrenaica is a mountain-dwelling ungulate with an extensive presence in open areas. Optimal group size results from the trade off between advantages (a reduction in the risk of predation) and disadvantages (competition between members of the herd) of group living. In addition, advantages and disadvantages of group living may vary depending on the position of each individual within the herd. Our objective was to study the effect of central vs. peripheral position in the herd on feeding and vigilance behavior in male and female Pyrenean chamois and to ascertain if a group size effect existed. We used focal animal sampling and recorded social interactions when a focal animal was involved. With males, vigilance rate was higher in the central part of the group than at the periphery, probably due to a higher density of animals in the central part of the herd and a higher probability of being disturbed by conspecifics. With females, vigilance rate did not differ according to position in the herd. Females spent more time feeding than males, and males showed a higher frequency of the vigilance behavior than females. We did not observe a clear relationship between group size and vigilance behavior. The differences in vigilance behavior might be due to social interactions 展开更多
关键词 Antagonistic interactions Group size POSITION Pyrenean chamois SEX VIGILANCE
下载PDF
Mineral Composition of the Donkey (Equus asinus) Muscle Meat 被引量:1
14
作者 Fernando Salazar-Pressler Virginia Melo-Ruiz +2 位作者 Karina Sanchez-Herrera Francisco Lopez-Naranjo Cesar Gazga-Urioste 《Journal of Life Sciences》 2018年第2期100-104,共5页
Donkey (Equus asinus) domesticated animal, is neglected as an object of scientific study. In countries where donkeys are used for work, they are slaughtered at the end of their useful working life and meat is destin... Donkey (Equus asinus) domesticated animal, is neglected as an object of scientific study. In countries where donkeys are used for work, they are slaughtered at the end of their useful working life and meat is destined for human consumption. This study was carried out to evaluate the mineral composition of donkey carcass meat. Meat was obtained in Donkey Fair 2016 at Mexico State, minerals were analyzed by Atomic Absorption Spectxophotometry, Ca, Na, K, Fe, Zn and Cu, and P content by colorimetry. Data obtained in mg/100g were: Ca, 7.95; Na, 48.75; K, 353; Fe, 3,95; Zn, 3.17; Cu, 0.19 and P, 227. Analysis revealed that donkey meat has a low content of Ca, but it is good in P as well as K. In conclusion donkey meat is a good source of minerals requested for human health. 展开更多
关键词 Donkey meat MINERALS NUTRITION health.
下载PDF
Social network search based on semantic analysis and learning 被引量:12
15
作者 Feifei Kou Junping Du +1 位作者 Yijiang He Lingfei Ye 《CAAI Transactions on Intelligence Technology》 2016年第4期293-302,共10页
Because of everyone's involvement in social networks, social networks are full of massive multimedia data, and events are got released and disseminated through social networks in the form of multi-modal and multi-att... Because of everyone's involvement in social networks, social networks are full of massive multimedia data, and events are got released and disseminated through social networks in the form of multi-modal and multi-attribute heterogeneous data. There have been numerous researches on social network search. Considering the spatio-temporal feature of messages and social relationships among users, we summarized an overall social network search framework from the perspective of semantics based on existing researches. For social network search, the acquisition and representation of spatio-temporal data is the basis, the semantic analysis and modeling of social network cross-media big data is an important component, deep semantic learning of social networks is the key research field, and the indexing and ranking mechanism is the indispensable part. This paper reviews the current studies in these fields, and then main challenges of social network search are given. Finally, we give an outlook to the prospect and further work of social network search. 展开更多
关键词 Semantic analysis Semantic learning CROSS-MODAL Social network search
下载PDF
New Media, Public Sphere, and Arab Spring: Demystifying the Power of Social Networks 被引量:1
16
《Journalism and Mass Communication》 2013年第4期226-239,共14页
This paper looks at the new media, communication, and political environment in both Tunisia and Egypt during and after the revolution. The new environment provided activists, politicians, civil society, and youth amon... This paper looks at the new media, communication, and political environment in both Tunisia and Egypt during and after the revolution. The new environment provided activists, politicians, civil society, and youth among others, who want to express their opinions and share their views, with various channels and means of corranunication to be part of the political action and to participate in the decision-making process. Social media played an important role in mobilizing youth to rally and protest. This is to say that a new model of communication has emerged with this new environment. The receiver has become the sender and the producer of the message. The process of communication, therefore, has been changed from one to many to from many to many, and everybody became sender and receiver at the same time. The main research question this paper aims to answer is: Are social networks enough to change the political and economic scene in the Arab World? And is there a relationship between the new communication environment and Arab spring? The year 2011 has been in the Arab world the year of social networks and radical changes in the political scene where a score of dictators were ousted. New political communication networks and mechanisms took place, and for the first time in Arab political communication, public opinion was a major political player. Social networks helped tremendously the formation of new public sphere where the public finds its way in the media and communication processes. At their best, new media can mobilize crowds and masses to rally and protest. They can give a social perspective to movements. However, they can't make change and implement democracy. After the collapse of the regimes in Tunisia and Egypt, things are not getting any better. There is no democratic transition, and both countries are experiencing complex economic, social, and political problems. 展开更多
关键词 social networks new media Arab Spring public sphere socioeconomic and political change
下载PDF
Aerodynamic characteristics of moving vehicles of two trains passing each other on bridge under crosswinds
17
作者 HU Hao XIANG Huo-yue +2 位作者 LIU Ke-hong ZHU Jin LI Yong-le 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第8期2558-2573,共16页
Two trains passing each other is controlling factor for the wind-vehicle-bridge systems.To test the aerodynamic characteristics of moving vehicles under crosswinds when two trains are passing each other,a wind tunnel ... Two trains passing each other is controlling factor for the wind-vehicle-bridge systems.To test the aerodynamic characteristics of moving vehicles under crosswinds when two trains are passing each other,a wind tunnel test device,which has two moving tracks,was developed.The rationality of the test result was discussed,the effects of intersection mode,yaw angle and lane spacing on the aerodynamic coefficients of the leeward train were analyzed,and the difference of aerodynamic coefficients between the head vehicle and the tail vehicle was discussed.The results show that the proposed test device has good repeatability.The intersection modes have a certain effect on the aerodynamic force of the leeward train when two trains are passing each other,and the results should be more reasonable during the two trains dynamic passing each other.With the decrease of yaw angle,the sudden change of train aerodynamic coefficients is more obvious.The decrease of lane spacing will increase the sudden change of leeward vehicles.In the process of two trains passing each other,the aerodynamic coefficients of the head vehicle and tail vehicle are significantly different,so the coupling vibration analysis of wind-vehicle-bridge system should be considered separately. 展开更多
关键词 two trains passing each other moving vehicle wind tunnel test aerodynamic characteristics crosswinds
下载PDF
Being Chinese in Lived Intercultural Experiences:A Discourse Analysis of Chinese Undergraduates’Perceptions of Chinese Culture 被引量:1
18
作者 Yuanyuan HE Lin XIAO 《Chinese Journal of Applied Linguistics》 2021年第2期219-240,264,共23页
The current study investigates a group of Chinese undergraduates’perceptions of Chinese culture.It examines the discourses that the students drew on to assign meaning to Chinese culture and how the students used thes... The current study investigates a group of Chinese undergraduates’perceptions of Chinese culture.It examines the discourses that the students drew on to assign meaning to Chinese culture and how the students used these discourses in constructing their Chinese cultural identity.A qualitative study was conducted collecting written self-reflective reports on critical intercultural incidents from 39 Chinese undergraduates at a university in Beijing.Questions designed to evoke reports from the students had them describe incidents in their past intercultural experiences that made them acutely aware of themselves“being Chinese”and specify aspects of Chinese culture that they felt such awareness could be attributed to.A discourse analysis reveals the multiplicity and contextuality of the students’notions of Chinese culture.The findings raise important considerations for contemporary Chinese undergraduates’cultural identity and their much debated“identity crisis.” 展开更多
关键词 Chinese cultural identity Chinese undergraduates intercultural communication social constructionism discourse
下载PDF
Reconfiguration of Spacecraft Cluster Based on Distributed Local Information
19
作者 YU Binggu WANG Shuquan 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2021年第4期704-712,共9页
The reconstruction of spacecraft cluster based on local information and distributed strategy is investigated.Each spacecraft is an intelligent individual that can detect information within a limited range and can dete... The reconstruction of spacecraft cluster based on local information and distributed strategy is investigated.Each spacecraft is an intelligent individual that can detect information within a limited range and can determine its behavior based on surrounding information.The objective of the cluster is to achieve the formation reconstruction with minimum fuel consumption.Based on the principle of dual pulse rendezvous maneuver,three target selection strategies are designed for collision avoidance.Strategy-1 determines the target point’s attribution according to the target’s distance when the target point conflicts and uses a unit pulse to avoid a collision.Strategy-2 changes the collision avoidance behavior.When two spacecraft meet more than once,the strategy switches the target points of the two spacecraft.In Strategy-3,the spacecraft closer to the target has higher priority in target allocation.Strategy-3 also switches the target points when two spacecraft encounter more than once.The three strategies for a given position,different completion times,and random position are compared.Numerical simulations show that all three strategies can accomplish the spacecraft cluster's reconfiguration under the specified requirements.Strategy-3 is better than Strategy-1 in all simulation cases in the sense of less fuel consumption with different completion times and given location,and it is more effective than Strategy-2 in most of the completion time.With a random initial position and given time,Strategy-3 is better than Strategy-1 in about 70%of the cases and more stable. 展开更多
关键词 spacecraft cluster formation reconstruction relative Lambert problem two-impulse rendezvous distributed maneuver
下载PDF
ACP-based social computing and parallel intelligence: Societies 5.0 and beyond 被引量:21
20
作者 XiaoWang Lingxi Li +2 位作者 Yong Yuan Peijun Ye Fei-Yue Wang 《CAAI Transactions on Intelligence Technology》 2016年第4期377-393,共17页
Social computing, as the technical foundation of future computational smart societies, has the potential to improve the effectiveness of opensource big data usage, systematically integrate a variety of elements includ... Social computing, as the technical foundation of future computational smart societies, has the potential to improve the effectiveness of opensource big data usage, systematically integrate a variety of elements including time, human, resources, scenarios, and organizations in the current cyber-physical-social world, and establish a novel social structure with fair information, equal rights, and a flat configuration. Meanwhile, considering the big modeling gap between the model world and the physical world, the concept of parallel intelligence is introduced. With the help of software-defined everything, parallel intelligence bridges the big modeling gap by means of constructing artificial systems where computational experiments can be implemented to verify social policies, economic strategies, and even military operations. Artificial systems play the role of "social laboratories" in which decisions are computed before they are executed in our physical society. Afterwards, decisions with the expected outputs are executed in parallel in both the artificial and physical systems to interactively sense, compute, evaluate and adjust system behaviors in real-time, leading system behaviors in the physical system converging to those proven to be optimal in the artificial ones. Thus, the smart guidance and management for our society can be achieved. 展开更多
关键词 Social computing Societies 5.0 Parallel intelligence Knowledge automation Cyber-physical-social system Artificial societies Computational ex-periments Parallel execution
下载PDF
上一页 1 2 7 下一页 到第
使用帮助 返回顶部