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Assessment of C-band compact polarimetry SAR for sea ice classification 被引量:3
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作者 ZHANG Xi ZHANG Jie +1 位作者 LIU Meijie MENG Junmin 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第5期79-88,共10页
The C-band synthetic aperture radar(SAR) data from the Bohai Sea of China, the Labrador Sea in the Arctic and the Weddell Sea in the Antarctic are used to analyze and discuss the sea ice full polarimetric informatio... The C-band synthetic aperture radar(SAR) data from the Bohai Sea of China, the Labrador Sea in the Arctic and the Weddell Sea in the Antarctic are used to analyze and discuss the sea ice full polarimetric information reconstruction ability under compact polarimetric modes. The type of compact polarimetric mode which has the highest reconstructed accuracy is analyzed, along with the performance impact of the reconstructed pseudo quad-pol SAR data on the sea ice detection and sea ice classification. According to the assessment and analysis, it is recommended to adopt the CTLR mode for reconstructing the polarimetric parameters σ_(HH)~0,σ_(VV)~0, H and α,while for reconstructing the polarimetric parameters σ_(HV)~0, ρ_(H-V), λ_1 and λ_2, it is recommended to use the π/4 mode.Moreover, it is recommended to use the π/4 mode in studying the action effects between the electromagnetic waves and sea ice, but it is recommended to use the CTLR mode for studying the sea ice classification. 展开更多
关键词 sea ice SAR compact polarimetry sea ice classification assessment and analysis
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Applicable conditions for a classification system of aquifer-protective mining in hallow coal seams 被引量:4
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作者 Liu Yude Zhang Dongsheng +1 位作者 Fan Gangwei Yah Shoufeng 《Mining Science and Technology》 EI CAS 2011年第3期381-387,共7页
Based on the conclusions of domestic and foreign research, we have analyzed the collapse-fall characteristics of overlying strata and the mechanism of aquifer-protective mining in shallow coal seam working faces at th... Based on the conclusions of domestic and foreign research, we have analyzed the collapse-fall characteristics of overlying strata and the mechanism of aquifer-protective mining in shallow coal seam working faces at the Shendong Mine. We have selected the height of the water-conducting fracture zone in overlying strata as a composite index and established the applicable conditions of aquifer-protective mining in shallow coal seams with a multi-factor synthetic-index classification method. From our calculations and analyses of variance, we used factors such as the overlying strata strength, mining disturbing factors and rock integrity as related factors of the composite index. We have classified the applicable conditions of aquifer-protective mining in shallow coal seams into seven types by comparing the result of the height of water-conducting fractured zones of long-wall and short-wall working faces with the thickness of the bedrock, the thickness of the weathered zone and the size of safety coal-rock pillars. As a result, we propose the preliminary classification system of aquifer-protective mining in shallow coal seams. It can provide a theoretical guidance for safe applications of aquifer-protective mining technology in shallow coal seams under similar conditions. 展开更多
关键词 Depth limits of shallow coal seamsAquifer-protective mining Comprehensive classification index analysisWater-conducting cranny zone analysis of variance
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DISCRETIZATION APPROACH USING RAY-TESTING MODEL IN PARTING LINE AND PARTING SURFACE GENERATION 被引量:3
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作者 HAN Jianwen JIAN Bin YAN Guangrong LEI Yi 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2007年第1期47-54,共8页
Surface classification, 3D parting line, parting surface generation and demoldability analysis which is helpful to select optimal parting direction and optimal parting line are involved in auto-matic cavity design bas... Surface classification, 3D parting line, parting surface generation and demoldability analysis which is helpful to select optimal parting direction and optimal parting line are involved in auto-matic cavity design based on the my-testing model. A new ray-testing approach is presented to classify the part surfaces to core/cavity surfaces and undercut surfaces by automatic identifying the visibility of surfaces. A simple, direct and efficient algorithm to identify surface visibility is developed. The algorithm is robust and adapted to rather complicated geometry, so it is valuable in computer-aided mold design systems. To validate the efficiency of the approach, an experimental program is implemented. Case studies show that the approach is practical and valuable in automatic parting line and parting surface generation. 展开更多
关键词 Visibility Ray-testing Surface classification Parting line Demoldability analysis
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Construction of unsupervised sentiment classifier on idioms resources 被引量:2
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作者 谢松县 王挺 《Journal of Central South University》 SCIE EI CAS 2014年第4期1376-1384,共9页
Sentiment analysis is the computational study of how opinions, attitudes, emotions, and perspectives are expressed in language, and has been the important task of natural language processing. Sentiment analysis is hig... Sentiment analysis is the computational study of how opinions, attitudes, emotions, and perspectives are expressed in language, and has been the important task of natural language processing. Sentiment analysis is highly valuable for both research and practical applications. The focuses were put on the difficulties in the construction of sentiment classifiers which normally need tremendous labeled domain training data, and a novel unsupervised framework was proposed to make use of the Chinese idiom resources to develop a general sentiment classifier. Furthermore, the domain adaption of general sentiment classifier was improved by taking the general classifier as the base of a self-training procedure to get a domain self-training sentiment classifier. To validate the effect of the unsupervised framework, several experiments were carried out on publicly available Chinese online reviews dataset. The experiments show that the proposed framework is effective and achieves encouraging results. Specifically, the general classifier outperforms two baselines(a Na?ve 50% baseline and a cross-domain classifier), and the bootstrapping self-training classifier approximates the upper bound domain-specific classifier with the lowest accuracy of 81.5%, but the performance is more stable and the framework needs no labeled training dataset. 展开更多
关键词 sentiment analysis sentiment classification bootstrapping idioms general classifier domain-specific classifier
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Particle shape characterisation and classification using automated microscopy and shape descriptors in batch manufacture of particulate solids 被引量:3
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作者 Yang Zhang Jing J. Liu +2 位作者 Lei Zhang Jorge Calderon De Anda Xue Z. Wang 《Particuology》 SCIE EI CAS CSCD 2016年第1期61-68,共8页
It is known that size alone, which is often defined as the volume-equivalent diameter, is not sufficient to characterize many particulate products. The shape of crystalline products can be as important as size in many... It is known that size alone, which is often defined as the volume-equivalent diameter, is not sufficient to characterize many particulate products. The shape of crystalline products can be as important as size in many applications, Traditionally, particulate shape is often defined by several simple descriptors such as the maximum length and the aspect ratio. Although these descriptors are intuitive, they result in a loss of information about the original shape. This paper presents a method to use principal component analysis to derive simple latent shape descriptors from microscope images of particulate products made in batch processes, and the use of these descriptors to identify batch-to-batch variations. Data from batch runs of both a laboratory crystalliser and an industrial crystallisation reactor are analysed using the described approach. Qualitative and quantitative comparisons with the use of traditional shape descriptors that have nhwical meanings and Fourier shape descriptors are also made. 展开更多
关键词 Batch-to-batch variation classification Principal components analysis Shape descriptors
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Genetic climatic regionalization of the Balkan Peninsula using cluster analysis 被引量:2
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作者 Peter NOJAROV 《Journal of Geographical Sciences》 SCIE CSCD 2017年第1期43-61,共19页
Sea Level Pressure(SLP) data for the period 1950–2012 at 61 stations located in or around the Balkan Peninsula was used. The main concept is that intra-annual course of SLP represents the best different air masses ... Sea Level Pressure(SLP) data for the period 1950–2012 at 61 stations located in or around the Balkan Peninsula was used. The main concept is that intra-annual course of SLP represents the best different air masses that are situated over the Balkan Peninsula during the year. The method for differentiation of climatic zones is cluster analysis. A hierarchical clustering technique–average linkage between groups with Pearson correlation for measurement of intervals was employed in the research. The climate of the Balkan Peninsula is transitional between oceanic and continental and also between subtropical and temperate climates. Several major changes in atmospheric circulation over the Balkan Peninsula have happened over the period 1950–2012. There is a serious increase of the influence of the Azores High in the period January–Marchwhich leads to an increase of SLP and enhances oceanic influence. There is an increase of the influence of the north-west extension of the monsoonal low in the period June–September. This leads to more continental climatebut also to more tropical air masses over the Balkan Peninsula. Accordinglythe extent of subtropical climate widens in northern direction. There is an increase of the influence of the Siberian High in the period October–December. This influence covers central and eastern part of the peninsula in October and Novemberand it reaches western parts in December. Thusthe climate becomes more continental. 展开更多
关键词 genetic classification regionalization Balkan Peninsula cluster analysis Sea Level Pressure circulation indices
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A dynamic two-zone model of continuous fluidized bed layering granulation with internal product classification 被引量:1
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作者 C. Neugebauer S. Palis +3 位作者 A. Buck E. Tsotsas S. Heinrich A. Kienle 《Particuology》 SCIE EI CAS CSCD 2017年第2期8-14,共7页
A dynamic two-zone model is proposed to address the formation of granulation and drying zones in fluidized bed layering granulation processes with internal product classification. The model assumes a constant volume f... A dynamic two-zone model is proposed to address the formation of granulation and drying zones in fluidized bed layering granulation processes with internal product classification. The model assumes a constant volume for the granulation zone, but a variable overall volume for the fluidized bed to account for classified product removal. The model is used to study the effect of various process parameters on dynamics and process stability. Stability is shown to depend on the separation diameter of product removal and the flow rate of the injected liquid. A lower and upper range of separation diameters with stable process behavior are found. In an intermediate range instability in the form of self-sustained oscillations is observed. The lower stability boundary is in qualitative agreement with recent experimental observations (Schmidt, Bück, & Tsotsas, 2015); the upper boundary was reported in a theoretical paper by Vreman, Van Lare, and Hounslow (2009) based on a single zone model. 展开更多
关键词 Layering granulation Zone formation Internal product classification Population balance modeling Stability analysis
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Concentrations and classification of HCHs and DDTs in soil from the lower reaches of the Jiulong River, China
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作者 Jiaquan ZHANG Shihua QI +5 位作者 Xinli XING Lingzhi TAN Wei CHEN Ying HU Dan YANG Chenxi WU 《Frontiers of Environmental Science & Engineering》 SCIE EI CAS CSCD 2012年第2期177-183,共7页
Soil is an important source to other environ- mental media and organisms for organochlorine pesticides (OCPs) bioaccumulation. Twenty-four representative sur- face soil samples were collected from the lower reaches ... Soil is an important source to other environ- mental media and organisms for organochlorine pesticides (OCPs) bioaccumulation. Twenty-four representative sur- face soil samples were collected from the lower reaches of the Jiulong River, China, in 2009. The concentrations of hexachlorocyclohexane isomers (HCHs) ranged from 0.38 to 39.52 ng.g~, with a mean value of 9.51 ng.g-~. The concentrations of dichlorodiphenyltrichloroethanes (DDTs) and their metabolites were within the ranges of 0.94-700.99 ng. gl, with a mean value of 71.17 ng. g-1. The concentrations of HCHs and DDTs in the soil were lower than the first grade level (50 ng. g-a) of the Chinese Environmental Quality Standard (GB 15618-1995). Hier- archical Cluster Analysis (HCA) and Pearson's bivariate Correlations Analysis (PCA) were used to analyse the distribution and contamination levels of OCPs in this region. The results showed that DDTs were the major contaminants and there were no significant correlations between various OCPs concentrations and the total organic carbon (TOC) contents. A significant positive correlation was observed between HCHs and DDTs (p 〈 0.01), which indicates that HCHs and DDTs may have similar sources and fate in the study area. 展开更多
关键词 Jiulong River hexachlorocyclohexane (HCH)and dichlorodiphenyltrichloroethan (DDT) classification Hierarchical Cluster analysis (HCA) Pearson's bivariateCorrelations analysis (PCA)
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Resilience assessment framework toward interdependent bus-rail transit network:Structure,critical components,and coupling mechanism
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作者 Bing Liu Xiaoyue Liu +2 位作者 Yang Yang Xi Chen Xiaolei Ma 《Communications in Transportation Research》 2023年第1期118-129,共12页
Understanding the interdependent nature of multimodal public transit networks(PTNs)is vital for ensuring the resilience and robustness of transportation systems.However,previous studies have predominantly focused on a... Understanding the interdependent nature of multimodal public transit networks(PTNs)is vital for ensuring the resilience and robustness of transportation systems.However,previous studies have predominantly focused on assessing the vulnerability and characteristics of single-mode PTNs,neglecting the impacts of heterogeneous disturbances and shifts in travel behavior within multimodal PTNs.Therefore,this study introduces a novel resilience assessment framework that comprehensively analyzes the coupling mechanism,structural and functional characteristics of bus-rail transit networks(BRTNs).In this framework,a network performance metric is proposed by considering the passengers’travel behaviors under various disturbances.Additionally,stations and subnetworks are classified using the k-means algorithm and resilience metric by simulating various disturbances occurring at each station or subnetwork.The proposed framework is validated via a case study of a BRTN in Beijing,China.Results indicate that the rail transit network(RTN)plays a crucial role in maintaining network function and resisting external disturbances in the interdependent BRTN.Furthermore,the coupling interactions between the RTN and bus transit network(BTN)exhibit distinct characteristics under infrastructure component disruption and functional disruption.These findings provide valuable insights into emergency management for PTNs and understanding the coupling relationship between BTN and RTN. 展开更多
关键词 Complex network Bus-rail transit network Resilience analysis Interdependent coupling relationship classification analysis
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Pathological demography of native patients in a nephrology center in China 被引量:24
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作者 陈惠萍 唐政 +10 位作者 曾彩虹 胡伟新 王庆文 俞雨生 姚小丹 王建平 朱茂艳 周虹 刘红 刘志红 黎磊石 《Chinese Medical Journal》 SCIE CAS CSCD 2003年第9期1377-1381,共5页
Objective To analysis the pathological demography in Chinese patients undergoing renal biopsy from our niphrology center.Methods Between January 1979 and October 2000 in Jinling Hospital, Nanjing, China, 10 002 attemp... Objective To analysis the pathological demography in Chinese patients undergoing renal biopsy from our niphrology center.Methods Between January 1979 and October 2000 in Jinling Hospital, Nanjing, China, 10 002 attempts of percutaneous renal were performed in patients with renal disease from 33 provinces of China. The pathological classifications were made according to the WHO criteria of 1982 for renal pathology or the modified WHO criteria of 1995 by a panel of pathologists and nephrologists during routine clinical-pathological rounds. The pathological demography between those specimens collected from 1979 -1989 and those from 1990 -1999 was compared.Results The mean age of the 10002 subjects undergoing renal biopsy was 31.4 ?3.0 years (ranging from 1 to 78 years), with a male to female ratio of 1. 3: 1; for the 592 renal transplant recipients, the mean age was 37. 5 ±9. 1 years (ranging from 16 to 66 years), with a male to female ratio of 2.36: 1. Primary glomerular diseases (PGD) accounted for 71% of the total patients undergoing renal biopsies, secondary glomerular nephritis (SGN) 23%, tubular-interstitial diseases 3. 2% , unclassified renal diseases 1. 3% , hereditary and congenital renal diseases 1. 0% , end stage renal diseases 0. 96% , and recently realized or rare renal diseases 0. 15%. IgA nephropathy (IgAN) was the most frequent pathological pattern (40%) of PGD, followed by mesangial proliferative lesion (MsPL) (30%), membranous nephropathy (MN) (10%), and focal segmental glomerulosclerosis ( FSGS) (6%). Lupus nephritis (LN) was the most pathology common seen (74%) in SGN. During the 22 years of the study period, there was a steady increase in patients with SGN discovered during pathological evaluation of renal disorders. A rise in prevalence was found in IgA nephropathy, MN (both P<0.001), crescentic glomerulonephritis (P<0. 0001), anti-GBM disease, and hemolytic-uremic syndrome/thrombotic thrombocytopenic purpura related renal damages ( both P < 0. 001 ). There was a decrease in endocapillary proliferative glomerulonephritis ( P < 0. 001 ) and IgM nephropathy (IgMN) ( P < 0. 01) from 1990 - 1999 as compared to 1979 - 1989. Infrequent renal pathological entities were also diagnosed in this group, including Niemann Pick disease, Fabry' s disease, POEMS syndrome, and lipoprotein glomerulonephropathy.Conclusions This is the largest series of renal biopsy data in China, and therefore may reflect the demographic picture of renal diseases in this country. Changes in prevalence of renal pathological entities were reflected in this group of patients over the last 22 years. In primary glomerular diseases, IgA nephropathy is still the most frequently observed pathological pattern. In SGN, LN appeared the most often. Increased prevalence was found in anti-GBM nephritis and HUS/TTP. 展开更多
关键词 retrospective analysis·renal biopsy·classification of renal pathology·China
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