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ON THE LEAST SQUARES PROBLEM OF A MATRIXEQUATION

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Journal of Computational Mathematics 1999年第6期17卷 589-594页

作者： An-ping Liao(college of science, Hunan normal university, Changsha 410081, china) 湖南师范大学理学院湖南长沙 410081

Least squares solution of F=PG with respect to positive semidefinite symmetric P is considered,a new necessary and sufficient condition for solvablity is given,and the expression of solution is derived in the some special cases. Based on the expression, the least spuares solution of an inverse eigenvalue problem for positive semidefinite symmetric matrices is also given.

关键词： least squares solution matrix equation inverse eigenvalue problem positive semidefinite symmetric matrix

Key technology of mine underground mobile positioning based on LiDAR and coded sequence pattern

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中国有色金属学会会刊：英文版 2011年第S3期21卷 570-576页

作者： WANG Zhi1, 2, WU Li-xin1, 2, LI Hui-ying3 1. college of resources and Civil Engineering, Northeastern university, Shenyang 110004, china 2. Academy of Disaster Reduction and Emergency Management, Ministry of Civil Affairs and Ministry of Education, Beijing normal university, Beijing 100875, china 3. college of Computer science and technology, Jilin university, Changchun 130012, china college of resources and Civil Engineering Northeastern University Shenyang 110004 China Academy of Disaster Reduction and Emergency Management Ministry of Civil Affairs and Ministry of Education Beijing Normal University Beijing 100875 China college of Computer science and technology Jilin University Changchun 130012 China

Technologies of underground mobile positioning were proposed based on LiDAR data and coded sequence pattern landmarks for mine shafts and tunnels environment to meet the needs of fast and accurate positioning and navigation of equipments in the mine underground without satellite navigation signals. A coded sequence pattern was employed for automatic matching of 3D scans. The methods of SIFT feature, Otsu segmentation and fast hough transformation were described for the identification, positioning and interpretation of the coded sequence patterns, respectively. The POSIT model was presented for speeding up computation of the translation and rotation parameters of LiDAR point data, so as to achieve automatic 3D mapping of mine shafts and tunnels. The moving positioning experiment was applied to evaluating the accuracy of proposed pose estimation method from LiDAR scans and coded sequence pattern landmarks acquired in an indoor environment. The performance was evaluated using ground truth data of the indoor setting so as to measure derivations with six degrees of freedom.

关键词： LiDAR coded sequence pattern mobile positioning SLAM algorithm POSIT algorithm

ENERGY FLOWS IN COMPLEX ECOLOGICAL SYSTEMS:A REVIEW

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Journal of Systems science & Complexity 2009年第3期22卷 345-359页

作者： Jiang ZHANG Department of Systems science,School of Management,Beijing normal university,Beijing 100875,china. Department of Systems science School of Management Beijing Normal University Beijing China

Energy flow drives the complex systems to *** allometric scaling as the universalenergy flow pattern has been found in different scales of ecological *** reflects the generalpower law relationship between flow and *** underlying mechanisms of energy flow patterns areexplained as the branching transportation networks which can be regarded as the result of systematicoptimization of a biological target under *** flows in the ecological system may bemodelled by the food web model and population dynamics on the *** paper reviews thelatest progress on the energy flow patterns,explanatory models for the allometric scaling and modellingapproach of flow and network evolution dynamics in ***,the possibility of generalizingthese flow patterns,modelling approaches to other complex systems is discussed.

关键词： Allometric scaling energy flow flows in complex systems food web.

A secure multi-party computation solution to intersection problems of sets and rectangles

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Progress in Natural science:Materials International 2006年第5期16卷 538-545页

作者： LI Shundong, DAI Yiqi, WANG Daoshun and LUO Ping (Department of Computer science and technology, Beijing normal university, Beijing 100875, china Department of Computer science and technology, Tsinghua university, Beijing 100084, china) Department of Computer science and technology Beijing Normal University Beijing 100875 China Department of Computer science and technology Tsinghua University Beijing 100084 China

Secure multi-party computation (SMC) is a research focus in international cryptographic community. At present, there is no SMC solution to the intersection problem of sets. In this paper, we first propose a SMC solution to this problem. Applying Cantor encoding method to computational geometry problems, and based on the solution to set-intersection problem, we further propose solutions to points inclusion problem and intersection problem of rectangles and further prove their privacy-preserving property with widely accepted simulation paradigm. Compared with the known solutions, these new solutions are of less computational complexity and less communication complexity, and have obvious superiority in computational and communication complexity.

关键词： Cantor encoding secure multi-party computation set-intersection rectangle-intersection computational complexity.

Spatio-temporal pattern analysis of single-trial EEG signals recorded during visual object recognition

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science china(Information sciences) 2011年第12期54卷 2519-2527页

作者： WANG ChangMing 1 , HU XiaoPing 3 , YAO Li 1,2 , XIONG Shi 2 & ZHANG JiaCai 2 1 National Key Laboratory of Cognitive Neuroscience and Learning, Beijing normal university, Beijing 100875, china 2 college of Information science and technology, Beijing normal university, Beijing 100875, china 3 Biomedical Imaging technology Center, Emory university/Georgia Institute of technology, Atlanta 30322, USA National Key Laboratory of Cognitive Neuroscience and Learning Beijing Normal University Beijing China Biomedical Imaging technology Center Emory University/Georgia Institute of Technology Atlanta USA college of Information science and technology Beijing Normal University Beijing China

Object discrimination is a fundamental cognitive function for human brains. In this study, we utilized an analysis approach for single-trial electroencephalography (EEG) to analyze the spatio-temporal activation patterns of visual objects processing in human brains, and attempted to apply it to discriminate different visual objects. The spatial patterns were respectively extracted from scalp EEG and the reconstructed cortical sources, while the experiment participants were perceiving 4 different categories of visual objects (faces, buildings, cats and cars). By classifying the patterns extracted from single-trial EEG, the presented visual objects could be discriminated by a computer, and the classification accuracies may provide a quantitative index to evaluate the spatial differences of the brain activations related to different visual objects. Our results demonstrated that the spatial patterns on both the scalp and the sources levels resulted in higher classification accuracies than chance rate. We also examined the classification results using temporally non-overlapping time intervals of different event-related potential (ERP) components. The temporal changes of classification accuracies may reflect the temporal distribution of the discriminative information in the EEG responses. The present pattern extraction and classification methods may compose a computational model for single-trial EEG data analysis in investigations of the spatio-temporal activation patterns for object recognition. These spatio-temporal patterns in EEG may be useful to identifying the discriminative spatial areas and time stages to improve the accuracies and efficiencies of object discrimination. In addition, investigating and utilizing humans'cognitive mechanisms of object recognition may improve computers' processing efficiency of visual information.

关键词： EEG spatio-temporal pattern object recognition single-trial analysis visual information processing

Sedimentary facies of the Silurian tide-dominated paleo-estuary of the Tazhong area in the Tarim Basin

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Petroleum science 2008年第2期5卷 95-104页

作者： Zhang Jinliang Zhang Zhongjie college of Resource science and technology Beijing Normal University Beijing 100875 China School of Marine Geo-science Ocean University of China Qingdao Shandong 266100 China

As the relative sea-level rose, a paleo-estuary was formed by the marine inundation of the braided river incised valley during the period of the lower sub-member of the upper member of the Kalpingtage. formation of the Silurian in the Tarim Basin, west china. Sandstone-mudstone rhythmite, tidal structures and bimodal cross-bedding are common in these deposits, indicating that tides played a significant role in generating the sedimentary structures and the estuary type was tide-dominated. Five depositional facies were grouped： tidal river, sandy and muddy subtidal flat, tidal flat, tidal bar, tidal channel on the basis of lithology, electric properties, rhythmicity, sedimentary structure, fossil and the contact relationship. The sediment distribution showing first fining seaward and subsequent coarsening seaward from head to mouth, implies the two sediment sources in the paleo-estuary. The paleo-estuary of the Tarim Basin is very different from other representative estuaries. The most important distinction is that there are two adjacent estuaries joined by tidal flat onshore and by sandy and muddy subtidal flat in the sea at the same time, while the others only architecture model for the tide-dominated estuary. have one, So the Tazhong paleo-estuary shows a good

关键词： Tarim basin Silurian tide-dominated estuary tidal river tidal bar

Landscape Change and its effect on the environment of Daqing City

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Progress in Natural science:Materials International 2005年第7期15卷 641-649页

作者： ZANG Shuying, ZHANG Jing and JIA Li ( college of Life and Environment science, Harbin normal university, Harbin 150080, china college of resources Environment & Tourism, Capital normal university, Beijing 100037, china college of Economics and Management, Northeast Agricultural university, Harbin 150030, china) college of Life and Environment science Harbin Normal University Harbin 150080 China college of resources Environment and Tourism Capital Normal University Beijing 100037 China college of Economics and Management Northeast Agricultural University Harbin 150030 China

In this paper, we will study the temporal-spatial landscape change from 1978 to 2001 in Daqing City, based on the mul- ti spectral scanner (MSS) and thematic mapper (TM) images of remote sensing (RS) of 1978, 1988, 1992, 1996 and 2001. In order to explain the effects of the component change on the whole landscape, we make a statistic analysis about the transfer probability matrix of the component types of the landscape by using the ARCGIS platform through the overlay analysis of different landscape components. Based on the transfer probability matrix, we calculate the in-transfer ratio, the out-transfer ratio and the contributor ratio of the special transfer process of the main landscape components. The results illustrate that the cultivated-land, grassland, swamp, and alkaline land are the main contributors resulting in the landscape change: the out-transfer ratios of grassland and swamp are much higher than the in-transfer ones; the in-transfer ratio of alkaline land is much higher than the out-transfer one; the in-transfer ratio of the land-lot is always higher than its out-transfer with the highest rate per year, although there is a small difference among the in-transfers and the out-transfers per year. The main landscape changing processes are the salination of cultivated-land, salination or desertification of grassland, salination and degeneration of swamp. Results in this paper can provide scientific basis for investigating the landscape change mechanism of resources-based city.

关键词： landscape change environmental effect transfer probability resources-based city.

Effect of rainfall interannual variability on the biomass and soil water distribution in a semiarid shrub community

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science china(Life sciences) 2010年第6期53卷 729-737页

作者： LIU JunShanXU XiaZHANG Yong,TIAN YuQiang & GAO Qiong State Key Laboratory of Earth Surface Processes and Resource Ecology,college of resources science & technology,Beijing normal university,Beijing 100875,china State Key Laboratory of Earth Surface Processes and Resource Ecology College of Resources Science & Technology Beijing Normal University Beijing China

The dynamics of biomass and soil moisture in semiarid land is driven by both the current rainfall and the ecosystem *** on a meta-analysis of existing experiments,an ecosystem model was used to calculate the effect of the rainfall interannual variability on the pattern of biomass and soil moisture in a shrub *** was found that rainfall interannual variability enabled shrubs to be more competitive than grasses,and to maintain the dominant role over a longer *** rainfall interannual variability resulted in complex soil moisture *** soil water recharge in wet years alternated with discharge in drought years.

关键词： rainfall shrub community Artemisia ordosica ecosystem model ecohydrology

Development and validation of a novel criterion of histologic healing in ulcerative colitis defined by inflammatory cell enumeration in lamina propria mucosa:A multicenter retrospective cohort in china

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Chinese Medical Journal 2024年第11期137卷 1316-1323页

作者： Han Gao Kangsheng Peng Yadi Shi Shenshen Zhu Ruicong Sun Chunjin Xu Ping Liu Zhi Pang Lanxiang Zhu Weichang Chen Baisui Feng Huili Wu Guangxi Zhou Mingsong Li Junxiang Li baijing Ding Zhanju Liu Center for IBD Research and Department of Gastroenterology Shanghai Tenth People’s HospitalTongji University School of MedicineShanghai 200085China Clinical Medicine Sanquan College of Xinxiang Medical UniversityXinxiangHenan 453003China Department of Gastroenterology The First People’s Hospital of Shangqiu City Affiliated to Xinxiang Medical UniversityShangqiuHenan 476100China Department of Gastroenterology Wuhu First People’s HospitalWuhuAnhui 241000China Department of Gastroenterology Suzhou Municipal Hospital Affiliated to Nanjing Medical UniversitySuzhouJiangsu 215008China Department of Gastroenterology The First Affiliated Hospital of Soochow UniversitySuzhouJiangsu 251006China Department of Gastroenterology The Second Affiliated Hospital of Zhengzhou UniversityZhengzhouHenan 450014China Department of Gastroenterology Zhengzhou Central Hospital Affiliated to Zhengzhou UniversityZhengzhouHenan 450000China Department of Gastroenterology The Affiliated Hospital of Jining Medical CollegeJiningShandong 272004China Department of Gastroenterology The Third Affiliated Hospital of Guangzhou Medical UniversityGuangzhouGuangdong 510140China Department of Gastroenterology Dongfang Hospital of Beijing University of Chinese MedicineBeijing 100078China

Background:Histological healing is closely associated with improved long-term clinical outcomes and lowered relapses in patients with ulcerative colitis(UC).Here,we developed a novel diagnostic criterion for assessing histological healing in UC ***:We conducted a retrospective cohort study in UC patients,whose treatment was iteratively optimized to achieve mucosal healing at Shanghai Tenth People’s Hospital of Tongji university from January 2017 to May *** identified an inflammatory cell enumeration index(ICEI)for assessing histological healing based on the proportions of eosinophils,CD177^(+)neutrophils,and CD40L^(+)T cells in the colonic lamina propria under high power field(HPF),and the outcomes(risks of symptomatic relapses)of achieving histological remission *** histological inflammation using Kaplan-Meier *** reliability and inter-reader reliability were evaluated by each *** relationships to the changes in the Nancy index and the Geboes score were also assessed for *** ICEI was further validated in a new cohort of UC patients from other nine university ***:We developed an ICEI for clinical diagnosis of histological healing,i.e.,Y=1.701X_(1)+0.758X_(2)+1.347X_(3)-7.745(X_(1),X_(2),and X_(3)represent the proportions of CD177^(+)neutrophils,eosinophils,and CD40L^(+)T cells,respectively,in the colonic lamina propria under HPF).The receiver operating characteristics curve(ROC)analysis revealed that Y2(95%confidence interval[CI]:0.905-0.979)with a sensitivity of 92.5%and a specificity of 83.6%(P2(95%CI:0.748-0.894).During an 18-month follow-up,patients with histological healing had a substantially better outcome com

关键词： Ulcerative colitis Histological healing Inflammatory cell enumeration index Prognosis