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Application of the probability-based covering algorithm model in text classification
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作者 ZHOU Ying 《Chinese Journal of Library and Information Science》 2009年第4期1-17,共17页
The probability-based covering algorithm(PBCA) is a new algorithm based on probability distribution. It decides, by voting, the class of the tested samples on the border of the coverage area, based on the probability ... The probability-based covering algorithm(PBCA) is a new algorithm based on probability distribution. It decides, by voting, the class of the tested samples on the border of the coverage area, based on the probability of training samples. When using the original covering algorithm(CA), many tested samples that are located on the border of the coverage cannot be classified by the spherical neighborhood gained. The network structure of PBCA is a mixed structure composed of both a feed-forward network and a feedback network. By using this method of adding some heterogeneous samples and enlarging the coverage radius,it is possible to decrease the number of rejected samples and improve the rate of recognition accuracy. Relevant computer experiments indicate that the algorithm improves the study precision and achieves reasonably good results in text classification. 展开更多
关键词 probability-based covering algorithm Structural training algorithm PROBABILITY Text classification
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Sequence optimization for multiple asteroids rendezvous via cluster analysis and probability-based beam search 被引量:5
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作者 LI HaiYang BAOYIN HeXi 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2021年第1期122-130,共9页
It is of great significance to visit multiple asteroids in a space mission.In this paper,the multiple asteroids mission optimization is implemented using cluster analysis and probability-based beam search.Clustering i... It is of great significance to visit multiple asteroids in a space mission.In this paper,the multiple asteroids mission optimization is implemented using cluster analysis and probability-based beam search.Clustering is performed to select the first asteroid to visit.Four cluster algorithms are investigated and affinity propagation is selected.Then four beam search algorithms that are deterministic beam search and three probability-based beam search variants,probabilistic beam search,ant-colony beam search,and evolving beam search,are applied to search for the rendezvous sequence.Deterministic beam search as a heuristic tree search algorithm is widely applied in multitarget sequence optimization,but it has an obvious drawback of the conflict between the number of pruned nodes and the possibility of finding optimal solutions,which can be improved by probability-based beam search.Among three probability-based beam search,the ant-colony beam search has a learning mechanism,and evolving beam search is constructed based on ant-colony beam search and has an evolutionary mechanism.Results show that the introduction of randomness can improve beam search,and beam search variants with the learning and evolutionary mechanism have an excellent performance. 展开更多
关键词 interplanetary trajectory optimization multi-target mission cluster analysis probability-based beam search
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Probability-based Clustering and Its Application to WLAN Location Estimation 被引量:3
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作者 张明华 张申生 曹健 《Journal of Shanghai Jiaotong university(Science)》 EI 2008年第5期547-552,共6页
Wireless local area networks (WLAN) localization based on received signal strength is becoming an important enabler of location based services. Limited efficiency and accuracy are disadvantages to the deterministic lo... Wireless local area networks (WLAN) localization based on received signal strength is becoming an important enabler of location based services. Limited efficiency and accuracy are disadvantages to the deterministic location estimation techniques. The probabilistic techniques show their good accuracy but cost more computation overhead. A Gaussian mixture model based on clustering technique was presented to improve location determination efficiency. The proposed clustering algorithm reduces the number of candidate locations from the whole area to a cluster. Within a cluster, an improved nearest neighbor algorithm was used to estimate user location using signal strength from more access points. Experiments show that the location estimation time is greatly decreased while high accuracy can still be achieved. 展开更多
关键词 probability-based clustering Gaussian mixture model wireless local area networks (WLAN) location estimation received signal strength
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Probability-Based Analyses of the Snap-Through in Cage-Shaped Mesostructures Under Out-of-Plane Compressions 被引量:1
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作者 Qing Liu Zhangming Shen +5 位作者 Zhi Liu Yumeng Shuai Zengyao Lv Tianqi Jin Xu Cheng Yihui Zhang 《Acta Mechanica Solida Sinica》 SCIE EI CSCD 2023年第4期569-581,共13页
Three-dimensional(3D)mesostructures with distinct compressive deformation behaviors and tunable mechanical responses have gained increasing interest in recent years.3D cage-shaped mesostructures are representative fra... Three-dimensional(3D)mesostructures with distinct compressive deformation behaviors and tunable mechanical responses have gained increasing interest in recent years.3D cage-shaped mesostructures are representative framework structures widely exploited in 3D flexible electronics,owing to their unique cellular geometry and unusual mechanical responses.The snap-through behavior of cage-shaped mesostructures could potentially result in the performance degradation of electronics,while it could also be harnessed to design reconfigurable electronics.Due to the complicated deformation modes and random characteristics in experiments,the snap-through behavior of cage-shaped mesostructures remains largely unexplored,espe-cially in terms of probability-based analyses.In this work,we present a systematic study on the configuration evolution and snap-through of 3D cage-shaped mesostructures under out-of-plane compressions.Experimental and computational studies show the existence of two distinct deformation modes associated with the snap-through,which is controlled by the energy barrier based on the energetic analyses.Phase diagrams of the deformation modes decode how key geometric parameters and assembly strain affect the snap-through.Compressive experiments based on periodic arrays(10 × 10)of mesostructures provided a large amount of deformation data,allowing for statistical analyses of the snap-through behavior.These results provide new insights and useful guidelines for the design of 3D reconfigurable devices and multistable metamaterials based on 3D cage-shaped mesostructures. 展开更多
关键词 3D cage-shaped mesostructures SNAP-THROUGH probability-based analyses 3D assembly Out-of-plane compression
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Towards multiple hazard resilient bridges:a methodology for modeling frequent and infrequent time-varying loads Part I,Comprehensive reliability and partial failure probabilities 被引量:9
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作者 Zach Liang George C.Lee 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2012年第3期293-301,共9页
The current AASHTO load and resistance factor design (LRFD) guidelines are formulated based on bridge reliability, which interprets traditional design safety factors into more rigorously deduced factors based on the... The current AASHTO load and resistance factor design (LRFD) guidelines are formulated based on bridge reliability, which interprets traditional design safety factors into more rigorously deduced factors based on the theory of probability. This is a major advancement in bridge design specifications. However, LRFD is only calibrated for dead and live loads. In cases when extreme loads are significant, they need to be individually assessed. Combining regular loads with extreme loads has been a major challenge, mainly because the extreme loads are time variables and cannot be directly combined with time invariant loads to formulate the probability of structural failure. To overcome these difficulties, this paper suggests a methodology of comprehensive reliability, by introducing the concept of partial failure probability to separate the loads so that each individual load combination under a certain condition can be approximated as time invariant. Based on these conditions, the extreme loads (also referred to as multiple hazard or MH loads) can be broken down into single effects. In Part II of this paper, a further breakdown of these conditional occurrence probabilities into pure conditions is discussed by using a live truck and earthquake loads on a bridge as an example. There are three major steps in establishing load factors from MH load distributions: (1) formulate the failure probabilities; (2) normalize various load distributions; and (3) establish design limit state equations. This paper describes the formulation of the failure probabilities of single and combined loads. 展开更多
关键词 multiple hazards bridge probability-based design comprehensive reliability partial failure probability
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Towards multiple hazard resilient bridges:a methodology for modeling frequent and infrequent time-varying loads Part Ⅱ,Examples for live and earthquake load effects 被引量:7
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作者 Zach Liang George C. Lee 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2012年第3期303-311,共9页
The current AASHTO load and resistance factor design (LRFD) guidelines are formulated based on bridge reliability, which interprets traditional design safety factors into more rigorously deduced factors based on the... The current AASHTO load and resistance factor design (LRFD) guidelines are formulated based on bridge reliability, which interprets traditional design safety factors into more rigorously deduced factors based on the theory of probability. This is a major advancement in bridge design specifications. However, LRFD is only calibrated for dead and live loads. In cases when extreme loads are significant, they need to be individually assessed. Combining regular loads with extreme loads has been a major challenge, mainly because the extreme loads are time variable and cannot be directly combined with time invariant loads to formulate the probability of structural failure.To overcome these difficulties, this paper suggests a methodology of comprehensive reliability, by introducing the concept of partial failure probability to separate the loads so that each individual load combination under a certain condition can be approximated a,; time invariant. Based on these conditions, the extreme loads (also referred to as multiple hazard or MH loads) can be broken down into single effects. In this paper, a further breakdown of these conditional occurrence probabilities into pure conditions is discussed by using a live truck and earthquake loads on a bridge as an example. 展开更多
关键词 multiple hazards bridge probability-based design comprehensive reliability partJ[al failure probability
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Multi-Mode Guided Waves Based Reference-Free Damage Diagnostic Imaging in Plates 被引量:1
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作者 Jiaqi Zhang Kehai Liu +3 位作者 Chang Gao Zhanjun Wu Yuebin Zheng Dongyue Gao 《Structural Durability & Health Monitoring》 EI 2019年第1期41-59,共19页
Probability-based diagnostic imaging(PDI)is one of the most well-known damage identification methods using guided waves.It is usually applied to diagnose damage in plates.The previous studies were dependent on the cer... Probability-based diagnostic imaging(PDI)is one of the most well-known damage identification methods using guided waves.It is usually applied to diagnose damage in plates.The previous studies were dependent on the certain damage index(DI)which is always calculated from the guided wave signals.In conventional methods,DI is simply defined by comparing the real-time data with the baseline data as reference.However,the baseline signal is easily affected by varying environmental conditions of structures.In this paper,a reference-free diagnostic imaging method is developed to avoid the influence of environmental factors,such as temperature and load conditions.The DI is defined based on the mode conversion of multi-mode guided waves with realtime signals without baseline signals.To improve the accuracy of diagnosis,two terms are included in the reference-free DI.One is called energy DI,which is defined based on the feature of signal energy.The other is called correlation DI and is defined based on the correlation coefficient.Then the PDI algorithm can be carried out instantaneously according to the reference-free DI.The real-time signals which are used to calculate DI are collected by the piezoelectric lead zirconate titanate(PZT)transducers placed on both sides of a plate.The numerical simulations by the finite element(FE)method on aluminum plates with PZT arrays are performed to validate the effectiveness of the reference-free damage diagnostic imaging.The approach is validated by two different arrays:a circle network and a square network.The results of diagnostic imaging are demonstrated and discussed in this paper.Furthermore,the advantage of reference-free DI is investigated by comparing the accuracy of defined reference-free DI and energy DI. 展开更多
关键词 Multi-mode guided waves probability-based diagnostic imaging referencefree mode conversion
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Transfer-based Approximate Dynamic Programmingfor Rolling Security-constrained Unit Commitment with Uncertainties
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作者 Jianquan Zhu Kai Zeng +3 位作者 Jiajun Chen Wenmeng Zhao Wenhao Liu Wenkai Zhu 《Protection and Control of Modern Power Systems》 SCIE EI 2024年第5期42-53,共12页
This paper studies the rolling security-constrained unit commitment(RSCUC)problem with AC power flow and uncertainties.For this NP-hard problem,it is modeled as a Markov decision process,which is then solved by a tran... This paper studies the rolling security-constrained unit commitment(RSCUC)problem with AC power flow and uncertainties.For this NP-hard problem,it is modeled as a Markov decision process,which is then solved by a transfer-based approximate dynamic programming(TADP)algorithm proposed in this paper.Different from traditional approximate dynamic programming(ADP)algorithms,TADP can obtain the commitment states of most units in advance through a decision transfer technique,thus reducing the action space of TADP significantly.Moreover,compared with traditional ADP algorithms,which require to determine the commitment state of each unit,TADP only needs determine the unit with the smallest on-state probability among all on-state units,thus further reducing the action space.The proposed algorithm can also prevent the iter-ative update of value functions and the reliance on rolling forecast information,which makes more sense in the rolling decision-making process of RSCUC.Finally,nu-merical simulations are carried out on a modified IEEE 39-bus system and a real 2778-bus system to demonstrate the effectiveness of the proposed algorithm. 展开更多
关键词 Rolling security-constrained unit com-mitment approximate dynamic programming decision transfer probability-based decision priority criterion uncertainty
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Near-ground trajectory planning for UAVs via multi-resolution hybrid voxel-surfel map 被引量:2
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作者 GAO TianYu WENG Rui +4 位作者 WU Tong ZHANG RuiXian HAN ChengZhe JI XiaoYu LIU Ming 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2023年第5期1245-1254,共10页
This paper is concerned with trajectory planning problems for UAVs operating near ground.Most existing studies focus on solving the problem of collision-free trajectory planning between pre-defined path points,but ign... This paper is concerned with trajectory planning problems for UAVs operating near ground.Most existing studies focus on solving the problem of collision-free trajectory planning between pre-defined path points,but ignore the need of navigation method for UAVs working on specific operating surfaces in near-ground space.In this paper,a novel near-ground trajectory planning framework is proposed,where the hybrid voxel-surfel map is developed to model the environment with special attention to the uneven operating surface.To improve the frequency of updates,a probability-based surfel fusion method and a resolution adaptive adjustment method based on the fusion result are proposed in this paper.By using possibility information in the map,a path search method is established to generate the initial trajectory.The trajectory is then further optimized based on map gradient information to generate a final trajectory that tracks the specified operating surface according to the task requirements.Compared with existing methods,the multi-resolution hybrid voxel-surfel map proposed in this paper has advantages in terms of operating efficiency.A series of experiments in simulated and real scenarios validate the effectiveness of the proposed trajectory planning framework. 展开更多
关键词 near-ground trajectory planning hybrid voxel-surfel map probability-based surfel fusion operating surface tracking
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