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Hybrid Chinese Information Retrieval Model Based on the Combination of Keyword and Concept 被引量:2
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作者 樊孝忠 李宏乔 李良富 《Journal of Beijing Institute of Technology》 EI CAS 2003年第S1期120-123,共4页
A hybrid model that is based on the Combination of keywords and concept was put forward. The hybrid model is built on vector space model and probabilistic reasoning network. It not only can exert the advantages of key... A hybrid model that is based on the Combination of keywords and concept was put forward. The hybrid model is built on vector space model and probabilistic reasoning network. It not only can exert the advantages of keywords retrieval and concept retrieval but also can compensate for their shortcomings. Their parameters can be adjusted according to different usage in order to accept the best information retrieval result, and it has been proved by our experiments. 展开更多
关键词 hybrid information retrieval model concept retrieval vector space model probabilistic reasoning network
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A novel dependency language model for information retrieval 被引量:1
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作者 CAI Ke-ke BU Jia-jun +1 位作者 CHEN Chun QIU Guang 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第6期871-882,共12页
This paper explores the application of term dependency in information retrieval (IR) and proposes a novel dependency retrieval model. This retrieval model suggests an extension to the existing language modeling (LM) a... This paper explores the application of term dependency in information retrieval (IR) and proposes a novel dependency retrieval model. This retrieval model suggests an extension to the existing language modeling (LM) approach to IR by introducing dependency models for both query and document. Relevance between document and query is then evaluated by reference to the Kullback-Leibler divergence between their dependency models. This paper introduces a novel hybrid dependency structure, which allows integration of various forms of dependency within a single framework. A pseudo relevance feedback based method is also introduced for constructing query dependency model. The basic idea is to use query-relevant top-ranking sentences extracted from the top documents at retrieval time as the augmented representation of query, from which the relationships between query terms are identified. A Markov Random Field (MRF) based approach is presented to ensure the relevance of the extracted sentences, which utilizes the association features between query terms within a sentence to evaluate the relevance of each sentence. This dependency retrieval model was compared with other traditional retrieval models. Experiments indicated that it produces significant improvements in retrieval effectiveness. 展开更多
关键词 Term dependency Language modeling (LM) retrieval model Sentence retrieval
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Understanding the role of human-inspired heuristics for retrieval models
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作者 Xiangsheng LI Yiqun LIU Jiaxin MAO 《Frontiers of Computer Science》 SCIE EI CSCD 2022年第1期11-21,共11页
Relevance estimation is one of the core concerns of information retrieval(IR)studies.Although existing retrieval models gained much success in both deepening our understanding of information seeking behavior and build... Relevance estimation is one of the core concerns of information retrieval(IR)studies.Although existing retrieval models gained much success in both deepening our understanding of information seeking behavior and building effective retrieval systems,we have to admit that the models work in a rather different manner from how humans make relevance judgments.Users’information seeking behaviors involve complex cognitive processes,however,the majority of these behavior patterns are not considered in existing retrieval models.To bridge the gap between practical user behavior and retrieval model,it is essential to systematically investigate user cognitive behavior during relevance judgement and incorporate these heuristics into retrieval models.In this paper,we aim to formally define a set of basic user reading heuristics during relevance judgement and investigate their corresponding modeling strategies in retrieval models.Further experiments are conducted to evaluate the effectiveness of different reading heuristics for improving ranking performance.Based on a large-scale Web search dataset,we find that most reading heuristics can improve the performance of retrieval model and establish guidelines for improving the design of retrieval models with human-inspired heuristics.Our study sheds light on building retrieval model from the perspective of cognitive behavior. 展开更多
关键词 reading heuristics retrieval model cognitive behavior
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Support Vector Machine active learning for 3D model retrieval 被引量:6
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作者 LENG Biao QIN Zheng LI Li-qun 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第12期1953-1961,共9页
In this paper, we present a novel Support Vector Machine active learning algorithm for effective 3D model retrieval using the concept of relevance feedback. The proposed method learns from the most informative objects... In this paper, we present a novel Support Vector Machine active learning algorithm for effective 3D model retrieval using the concept of relevance feedback. The proposed method learns from the most informative objects which are marked by the user, and then creates a boundary separating the relevant models from irrelevant ones. What it needs is only a small number of 3D models labelled by the user. It can grasp the user's semantic knowledge rapidly and accurately. Experimental results showed that the proposed algorithm significantly improves the retrieval effectiveness. Compared with four state-of-the-art query refinement schemes for 3D model retrieval, it provides superior retrieval performance after no more than two rounds of relevance feedback. 展开更多
关键词 3D model retrieval Shape descriptor Relevance feedback Support Vector Machine (SVM) Active learning
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High Efficient Methods of Content-based 3D Model Retrieval 被引量:5
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作者 WU Yuanhao TIAN Ling LI Chenggang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第2期248-256,共9页
Content-based 3D model retrieval is of great help to facilitate the reuse of existing designs and to inspire designers during conceptual design. However, there is still a gap to apply it in industry due to the low tim... Content-based 3D model retrieval is of great help to facilitate the reuse of existing designs and to inspire designers during conceptual design. However, there is still a gap to apply it in industry due to the low time efficiency. This paper presents two new methods with high efficiency to build a Content-based 3D model retrieval system. First, an improvement is made on the "Shape Distribution (D2)" algorithm, and a new algorithm named "Quick D2" is proposed. Four sample 3D mechanical models are used in an experiment to compare the time cost of the two algorithms. The result indicates that the time cost of Quick D2 is much lower than that of D2, while the descriptors extracted by the two algorithms are almost the same. Second, an expandable 3D model repository index method with high performance, namely, RBK index, is presented. On the basis of RBK index, the search space is pruned effectively during the search process, leading to a speed up of the whole system. The factors that influence the values of the key parameters of RBK index are discussed and an experimental method to find the optimal values of the key parameters is given. Finally, "3D Searcher", a content-based 3D model retrieval system is developed. By using the methods proposed, the time cost for the system to respond one query online is reduced by 75% on average. The system has been implemented in a manufacturing enterprise, and practical query examples during a case of the automobile rear axle design are also shown. The research method presented shows a new research perspective and can effectively improve the content-based 3D model retrieval efficiency. 展开更多
关键词 3D model retrieval high efficient methods shape descriptor extraction model repository index
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3D Model Retrieval Method Based on Affinity Propagation Clustering 被引量:2
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作者 Lin Lin Xiao-Long Xie Fang-Yu Chen 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2013年第3期12-21,共10页
In order to improve the accuracy and efficiency of 3D model retrieval,the method based on affinity propagation clustering algorithm is proposed. Firstly,projection ray-based method is proposed to improve the feature e... In order to improve the accuracy and efficiency of 3D model retrieval,the method based on affinity propagation clustering algorithm is proposed. Firstly,projection ray-based method is proposed to improve the feature extraction efficiency of 3D models. Based on the relationship between model and its projection,the intersection in 3D space is transformed into intersection in 2D space,which reduces the number of intersection and improves the efficiency of the extraction algorithm. In feature extraction,multi-layer spheres method is analyzed. The two-layer spheres method makes the feature vector more accurate and improves retrieval precision. Secondly,Semi-supervised Affinity Propagation ( S-AP) clustering is utilized because it can be applied to different cluster structures. The S-AP algorithm is adopted to find the center models and then the center model collection is built. During retrieval process,the collection is utilized to classify the query model into corresponding model base and then the most similar model is retrieved in the model base. Finally,75 sample models from Princeton library are selected to do the experiment and then 36 models are used for retrieval test. The results validate that the proposed method outperforms the original method and the retrieval precision and recall ratios are improved effectively. 展开更多
关键词 feature extraction project ray-based method affinity propagation clustering 3D model retrieval
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Multi-level spherical moments based 3D model retrieval
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作者 LIU Wei HE Yuan-jun 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第9期1500-1507,共8页
In this paper a novel 3D model retrieval method that employs multi-level spherical moment analysis and relies on voxelization and spherical mapping of the 3D models is proposed. For a given polygon-soup 3D model, firs... In this paper a novel 3D model retrieval method that employs multi-level spherical moment analysis and relies on voxelization and spherical mapping of the 3D models is proposed. For a given polygon-soup 3D model, first a pose normalization step is done to align the model into a canonical coordinate frame so as to define the shape representation with respect to this orientation. Afterward we rasterize its exterior surface into cubical voxel grids, then a series of homocentric spheres with their center superposing the center of the voxel grids cut the voxel grids into several spherical images. Finally moments belonging to each sphere are computed and the moments of all spheres constitute the descriptor of the model. Experiments showed that Euclidean distance based on this kind of feature vector can distinguish different 3D models well and that the 3D model retrieval system based on this arithmetic yields satisfactory performance. 展开更多
关键词 3D model retrieval Spherical moments Feature extraction Pose normalization
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NON-LINEAR DYNAMIC MODEL RETRIEVAL OF SUBTROPICAL HIGH BASED ON EMPIRICAL ORTHOGONAL FUNCTION AND GENETIC ALGORITHM
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作者 张韧 洪梅 +4 位作者 孙照渤 牛生杰 朱伟军 闵锦忠 万齐林 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2006年第12期1645-1653,共9页
Aiming at the difficulty of accurately constructing the dynamic model of subtropical high, based on the potential height field time series over 500 hPa layer of T106 numerical forecast products, by using EOF(empirica... Aiming at the difficulty of accurately constructing the dynamic model of subtropical high, based on the potential height field time series over 500 hPa layer of T106 numerical forecast products, by using EOF(empirical orthogonal function) temporal-spatial separation technique, the disassembled EOF time coefficients series were regarded as dynamical model variables, and dynamic system retrieval idea as well as genetic algorithm were introduced to make dynamical model parameters optimization search, then, a reasonable non-linear dynamic model of EOF time-coefficients was established. By dynamic model integral and EOF temporal-spatial components assembly, a mid-/long-term forecast of subtropical high was carried out. The experimental results show that the forecast results of dynamic model are superior to that of general numerical model forecast results. A new modeling idea and forecast technique is presented for diagnosing and forecasting such complicated weathers as subtropical high. 展开更多
关键词 genetic algorithm empirical orthogonal function non-linear model retrieval subtropical high
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Three-Dimensional Model Retrieval Using Dynamic Multi-Descriptor Fusion
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作者 Jau-Ling Shih Chang-Hsing Lee +1 位作者 Yao-Wen Hou Po-Ting Yen 《Journal of Electronic Science and Technology》 CAS CSCD 2017年第2期169-177,共9页
In this paper, we propose a dynamic multi-descriptor fusion (DMDF) approach to improving the retrieval accuracy of 3-dimensional (3D) model retrieval systems. First, an independent retrieval list is generated by u... In this paper, we propose a dynamic multi-descriptor fusion (DMDF) approach to improving the retrieval accuracy of 3-dimensional (3D) model retrieval systems. First, an independent retrieval list is generated by using each individual descriptor. Second, we propose an automatic relevant/irrelevant models selection (ARMS) approach to selecting the relevant and irrelevant 3D models automatically without any user interaction. A weighted distance, in which the weight associated with each individual descriptor is learnt by using the selected relevant and irrelevant models, is used to measure the similarity between two 3D models. Furthermore, a descriptor-dependent adaptive query point movement (AQPM) approach is employed to update every feature vector. This set of new feature vectors is used to index 3D models in the next search process. Four 3D model databases are used to compare the retrieval accuracy of our proposed DMDF approach with several descriptors as well as some well-known information fusion methods. Experimental results have shown that our proposed DMDF approach provides a promising retrieval result and always yields the best retrieval accuracy. 展开更多
关键词 Index Terms--Three-dimensional (3D) model retrieval automatic relevant/irrelevant models selection (ARMS) feature re-weighting (FRW) query point movement (QPM).
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Ontology Framework for Content-Based 3D Model Retrieval
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作者 黄世国 周明全 +2 位作者 耿国华 宁正元 王克刚 《Journal of Donghua University(English Edition)》 EI CAS 2010年第2期242-245,共4页
The goal of the research on ontology framework for content-based 3D model retrieval is to develop a rich set of 3D model semantic representation so that both humans and machines can generate and understand model descr... The goal of the research on ontology framework for content-based 3D model retrieval is to develop a rich set of 3D model semantic representation so that both humans and machines can generate and understand model descriptions and processing for fast efficient retrieval from model collections. The purpose of ontology development for content-based 3D model retrieval is intended to describe model information regardless of storage, feature extraction and creation. The ontology includes the information on media features, low level visual descriptors, non media features of 3D model and their relationships. It is implemented in protege 3.1. 展开更多
关键词 content-based retrieval 3D model ontology
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Solid model edit distance: a multi-application and multi-level schema for CAD model retrieval
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作者 Wang Bin Hu Kaimo +1 位作者 Li Dong Zhang Hui 《Computer Aided Drafting,Design and Manufacturing》 2017年第1期22-38,共17页
We present the solid model edit distance(SMED),a powerful and flexible paradigm for exploiting shape similarities amongst CAD models.It is designed to measure the magnitude of distortions between two CAD models in bou... We present the solid model edit distance(SMED),a powerful and flexible paradigm for exploiting shape similarities amongst CAD models.It is designed to measure the magnitude of distortions between two CAD models in boundary representation(B-rep).We give the formal definition by analogy with graph edit distance,one of the most popular graph matching methods.To avoid the expensive computational cost potentially caused by exact computation,an approximate procedure based on the alignment of local structure sets is provided in addition.In order to verify the flexibility,we make intensive investigations on three typical applications in manufacturing industry,and describe how our method can be adapted to meet the various requirements.Furthermore,a multilevel method is proposed to make further improvements of the presented algorithm on both effectiveness and efficiency,in which the models are hierarchically segmented into the configurations of features.Experiment results show that SMED serves as a reasonable measurement of shape similarity for CAD models,and the proposed approach provides remarkable performance on a real-world CAD model database. 展开更多
关键词 CAD model retrieval solid model edit distance graph edit distance boundary representation
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Leaf area index retrieval based on canopy reflectance and vegetation index in eastern China 被引量:5
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作者 JIANGJianjun CHENSuozhong +3 位作者 CAOShunxian WUHongan ZHANGLi ZHANGHailong 《Journal of Geographical Sciences》 SCIE CSCD 2005年第2期247-254,共8页
The aim of this paper is to investigate the feasibility of using Landsat TM data to retrieve leaf area index (LAI). To get a LAI retrieval model based ground reflectance and vegetation index, detailed field data were ... The aim of this paper is to investigate the feasibility of using Landsat TM data to retrieve leaf area index (LAI). To get a LAI retrieval model based ground reflectance and vegetation index, detailed field data were collected in the study area of eastern China, dominated by bamboo, tea plant and greengage. Plant canopy reflectance of Landsat TM wavelength bands has been inversed using software of 6S. LAI is an important ecological parameter. In this paper, atmospheric corrected Landsat TM imagery was utilized to calculate different vegetation indices (VI), such as simple ratio vegetation index (SR), shortwave infrared modified simple ratio (MSR), and normalized difference vegetation index (NDVI). Data of 53 samples of LAI were measured by LAI-2000 (LI-COR) in the study area. LAI was modeled based on different reflectances of bands and different vegetation indices from Landsat TM and LAI samples data. There are certainly correlations between LAI and the reflectance of TM3, TM4, TM5 and TM7. The best model through analyzing the results is LAI = 1.2097*MSR + 0.4741 using the method of regression analysis. The result shows that the correlation coefficient R2 is 0.5157, and average accuracy is 85.75%. However, whether the model of this paper is suitable for application in subtropics needs to be verified in the future. 展开更多
关键词 Landsat TM Leaf Area Index (LAI) vegetation indices retrieval model Taihu Lake
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Semi-supervised Support Vector Regression Model for Remote Sensing Water Quality Retrieving 被引量:3
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作者 WANG Xili FU Li MA Lei 《Chinese Geographical Science》 SCIE CSCD 2011年第1期57-64,共8页
This paper proposed a semi-supervised regression model with co-training algorithm based on support vector machine, which was used for retrieving water quality variables from SPOT 5 remote sensing data. The model consi... This paper proposed a semi-supervised regression model with co-training algorithm based on support vector machine, which was used for retrieving water quality variables from SPOT 5 remote sensing data. The model consisted of two support vector regressors (SVRs). Nonlinear relationship between water quality variables and SPOT 5 spectrum was described by the two SVRs, and semi-supervised co-training algorithm for the SVRs was es-tablished. The model was used for retrieving concentrations of four representative pollution indicators―permangan- ate index (CODmn), ammonia nitrogen (NH3-N), chemical oxygen demand (COD) and dissolved oxygen (DO) of the Weihe River in Shaanxi Province, China. The spatial distribution map for those variables over a part of the Weihe River was also produced. SVR can be used to implement any nonlinear mapping readily, and semi-supervis- ed learning can make use of both labeled and unlabeled samples. By integrating the two SVRs and using semi-supervised learning, we provide an operational method when paired samples are limited. The results show that it is much better than the multiple statistical regression method, and can provide the whole water pollution condi-tions for management fast and can be extended to hyperspectral remote sensing applications. 展开更多
关键词 semi-supervised learning support vector regression CO-TRAINING water quality retrieving model SPOT 5
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Study on Remote Sensing of Water Depths Based on BP Artificial Neural Network 被引量:4
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作者 王艳姣 张培群 +1 位作者 董文杰 张鹰 《Marine Science Bulletin》 CAS 2007年第1期26-35,共10页
A momentum BP neural network model (MBPNNM) was constructed to retrieve the water depth information for the South Channel of the Yangtze River Estuary using the relationship between the reflectance derived from Land... A momentum BP neural network model (MBPNNM) was constructed to retrieve the water depth information for the South Channel of the Yangtze River Estuary using the relationship between the reflectance derived from Landsat 7 satellite data and the water depth information. Results showed that MBPNNM, which exhibited a strong capability of nonlinear mapping, allowed the water depth information in the study area to be retrieved at a relatively high level of accuracy. Affected by the sediment concentration of water in the estuary, MBPNNM enabled the retrieval of water depth of less than 5 meters accurately. However, the accuracy was not ideal for the water depths of more than 10 meters. 展开更多
关键词 Yangtze River Estuary BP neural network water-depth remote sensing retrieval model
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Leakage-Resilient Signature Scheme Based on BLS Signature
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作者 王志伟 《China Communications》 SCIE CSCD 2011年第3期212-215,共4页
Digital signature,one of the most important cryptographic primitives,has been commonly used in information systems,and thus enhancing the security of a signature scheme can benefit such an application.Currently,leakag... Digital signature,one of the most important cryptographic primitives,has been commonly used in information systems,and thus enhancing the security of a signature scheme can benefit such an application.Currently,leakage-resilient cryptography is a very hot topic in cryptographic research.A leakage-resilient cryptographic primitive is said to be secure if arbitrary but bounded information about the signer's secret key(involving other states) is leaked to an adversary.Obviously,the leakage-resilient signature is more secure than the common signature.We construct an efficient leakage-resilient signature scheme based on BLS signature in the bounded retrieval model.We also prove that our scheme is provably secure under BLS signature. 展开更多
关键词 leakage-resilient signature bounded retrieval model BLS signature system key leakage attacks information systems
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Joint shape and color descriptors for 3D urban model retrieval
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作者 Liang Zhang Liqiang Zhang +2 位作者 Xiaojing Yao P.Takis Mathiopoulos Chunming Han 《International Journal of Digital Earth》 SCIE EI CSCD 2016年第11期1117-1134,共18页
With the rapid development of photogrammetry,computer vision and three-dimensional(3D)modeling technologies,it is possible to efficiently construct detailed 3D urban models.Accordingly,large corpora of 3D models,such ... With the rapid development of photogrammetry,computer vision and three-dimensional(3D)modeling technologies,it is possible to efficiently construct detailed 3D urban models.Accordingly,large corpora of 3D models,such as the Google 3D Warehouse,are now becoming freely available on the web.How to find the proper 3D urban models is a challenging research issue.In this paper,we join shape descriptors and color descriptors for 3D urban model retrieval.The query objects are localized and segmented automatically from the input images by using a new selective search voting algorithm.Through combining the normalization with the light field descriptor,the Horizontal Light Descriptor is introduced to measure the shape similarity among the normalized urban models.The color descriptors are used to represent the color information of the urban models.The two types of descriptors are joined to search 3D urban models similar to the query objects.Experimental results have shown the effectiveness of our approach. 展开更多
关键词 3D urban models shape descriptor color descriptor model retrieval
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THE STUDY OF RETRIEVAL THEORY AND METHODS FROM SATELLITE REMOTE SENSING FOR METEOROLOGICAL PARAMETERS OVER EASTERN ASIA-PARTI:ISPRM AND SRRM 被引量:2
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作者 黎光清 张文建 +5 位作者 董超华 张凤英 张丽霞 冉茂农 罗东风 王保华 《Acta meteorologica Sinica》 SCIE 2000年第3期257-267,共11页
A review of ten-year's practice in developing the improved simultaneous physical retrieval method(ISPRM)is given in the hope that some creative ideas can be drawn from it.The improvement upon the SPRM is associate... A review of ten-year's practice in developing the improved simultaneous physical retrieval method(ISPRM)is given in the hope that some creative ideas can be drawn from it.The improvement upon the SPRM is associated with the under-determinedness of this ill-posed inverse problem.In our experiment,the precondition is observed that prior information must be independent of the satellite measurements.The well-posed retrieval theory has told us that the forward process is fundamental for the retrieval,and it is the bridge between the input of satellite radiance and the output of retrievals.In order to obtain a better result from the forward process. the full advantage of every prior information available must be taken.It is necessary to turn the ill- posed inverse problem into the well-posed one.Then by using the Ridge regression or Bayes algorithm to find the optimal combination among the first guess,the theoretical analogue information and the satellite observations,the impact of the under-determinedness of this inverse problem on the numerical solution is minimized. 展开更多
关键词 simultaneous physical retrieval model(SPRM) statistical regression retrieval model(SRRM).under-determlnedness of ill-posed inverse problem prior information well-posed inverse theory verification
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THE STUDY OF RETRIEVAL THEORY AND METHODS FROM SATELLITE REMOTE SENSING FOR METEOROLOGICAL PARAMETERS OVER EASTERN ASIA—PART Ⅱ:ISPRM AND VSPRM2
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作者 黎光清 董超华 +6 位作者 张文建 张凤英 王保华 冉茂农 吴雪宝 王维和 潘宁 《Acta meteorologica Sinica》 SCIE 2000年第4期475-489,共15页
Based on the practice of improved simultaneous physical retrieval model(ISPRM),in the light of the functional analysis approach,the variational simultaneous physical retrieval model (VSPRM)has been developed.Its appro... Based on the practice of improved simultaneous physical retrieval model(ISPRM),in the light of the functional analysis approach,the variational simultaneous physical retrieval model (VSPRM)has been developed.Its approximation of 1st degree is VSPRM1,which is identical with the ISPRM.Its approximation of 2nd degree is VSPRM2,more advanced than the VSPRM1. This paper has analyzed the function of VSPRM2,pointing out the potentiality of synergy retrieval of this model.Also,it has dealt with the problem of parameterization of water vapor's kernel functions and retrieval of water vapor remote sensing. Because of the characteristics of this strong ill posed inverse problem,prior information must be used wisely in order to get the accurate calculation of radiance R.In the previous paper,we discussed how to build the best first guess field,the way to determine the P_s and to correct the calculation of radiance.In this paper,we continue discussing in depth about the calculation of transmittance,the determination of surface parameters and the selection for an optimum combination of channels for the low-level sounding. The long-term experiment and comparison work under operational environment have shown that the ISPRM is useful for retrieval of temperature and water vapor parameters over China including the Tibetan Plateau,and it further proves the scientific nature of well-posed inverse theory. 展开更多
关键词 improved simultaneous physical retrieval model(ISPRM) variational simultaneous physical retrieval model(VSPRM) synergy remote sensing retrieval parameterization for kernel functions of water vapor
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Information retrieval:a view from the Chinese IR community
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作者 Zhumin CHEN Xueqi CHENG +16 位作者 Shoubin DONG Zhicheng DOU Jiafeng GUO Xuanjing HUANG Yanyan LAN Chenliang LI Ru LI Tie-Yan LIU Yiqun LIU Jun MA Bing QIN Mingwen WANG Jirong WEN Jun XU Min ZHANG Peng ZHANG Qi ZHANG 《Frontiers of Computer Science》 SCIE EI CSCD 2021年第1期197-211,共15页
During a two day strategic workshop in February 2018,22 information retrieval researchers met to discuss the future challenges and opportunities within the field.The outcome is a list of potential research directions,... During a two day strategic workshop in February 2018,22 information retrieval researchers met to discuss the future challenges and opportunities within the field.The outcome is a list of potential research directions,project ideas,and challenges.This report describes the major conclusions we have obtained during the workshop.A key result is that we need to open our mind to embrace a broader IR field by rethink the definition of information,retrieval,user,system,and evaluation of IR.By providing detailed discussions on these topics,this report is expected to inspire our IR researchers in both academia and industry,and help the future growth of the IR research community. 展开更多
关键词 information retrieval REDEFINITION information scope of retrieval retrieval models USERS system architecture evaluation
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3D object retrieval based on histogram of local orientation using one-shot score support vector machine 被引量:2
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作者 Vahid MEHRDAD Hossein EBRAHIMNEZHAD 《Frontiers of Computer Science》 SCIE EI CSCD 2015年第6期990-1005,共16页
In this paper, a content based descriptor is pro- posed to retrieve 3D models, which employs histogram of local orientation (HLO) as a geometric property of the shape. The proposed 3D model descriptor scheme consist... In this paper, a content based descriptor is pro- posed to retrieve 3D models, which employs histogram of local orientation (HLO) as a geometric property of the shape. The proposed 3D model descriptor scheme consists of three steps. In the first step, Poisson equation is utilized to define a 3D model signature. Next, the local orientation is calculated for each voxel of the model using Hessian matrix. As the final step, a histogram-based 3D model descriptor is extracted by accumulating the values of the local orientation in bins. Due to efficiency of Poisson equation in describing the models with various structures, the proposed descriptor is capable of discriminating these models accurately. Since, the inner vox- els have a dominant contribution in the formation of the de- scriptor, sufficient robustness against noise can be achieved. This is because the noise mostly influences the boundary vox- els. Furthermore, we improve the retrieval performance us- ing support vector machine based one-shot score (SVM-OSS) similarity measure, which is more efficient than the conven- tional methods to compute the distance of feature vectors. The rotation normalization is performed employing the prin- cipal component analysis. To demonstrate the applicability of HLO, we implement experimental evaluations of precision- recall curve on ESB, PSB and WM-SHREC databases of 3D models. Experimental results validate the effectiveness of the proposed descriptor compared to some current methods. 展开更多
关键词 3D model retrieval histogram of local orientation visual based shape descriptor poisson equation
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