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Approximation of dense-n/2-subgraph and table compression problems

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Science China Mathematics 2005年第9期48卷 1223-1233页

作者： XU Dachuan~1.HAN Jiye~2 & du Dongle~3 1. College of Applied Sciences,Beijing University of Technology,Beijing 1.0022,China 2. Institute of Applied Mathematics,Academy of Mathematics and Systems Science,Chinese Academy of Sciences,Beijing 1.0080,China 3. Faculty of Administration,University of New Brunswick,P.O.Box 4400,Fredericton,NB E3B 5A3,Canada College of Applied Sciences Beijing University of Technology Beijing 100022 China Institute of Applied Mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China Faculty of Administration University of New Brunswick P.O. Box 4400 Fredericton NB E3B 5A3 Canada

We develop improved approximation algorithms for two NP-hard problems: the dense-n/2-subgraph and table *** on SDP relaxation and advanced rounding techniques,we first propose 0. 5982 and 0. 5970-approximation algorithms respec- tively for the dense-n/2-subgraph problem (DSP) and the table compression problem (TCP). Then we improve these bounds to 0. 6243 and 0. 6708 respectively for DSP and TCP by adding triangle inequalities to strengthen the SDP *** results for TCP beat the 0. 5 bound of a simple greedy algorithm on this problem,and hence answer an open question of Anderson in an affirmative way.

关键词： dense-n/2-subgraph problem(DSP) table compression problem(TCP) SDP approximation ratio

The Method of Intelligent Inspection of Product Quality Based on Computer Vision

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The Method of Intelligent Inspection of Product Quality Base...

Research on the Control Model of Coordinated Development with Large Scale System for Producer Service Industry

The 7th International Conference on Computer-Aided Industrial Design and Conceptual Design (CAID&CD’2006)

作者： YAN Tai-shan 1.2 CUI du-wu 1.(1. Institute of Automation Science Xi’an University of Technology Xi’an Shaanxi 71.048) (2.Department of Computer Science Hunan Institute of Technology Yueyang Hunan 41.000)

The technique of automated visual inspection is a new development in computer inspection. It has many advantages such as no touching with inspected objects, high speed, high efficiency and good flexibility, etc.. So it has extensive applied foreground in the modern automatic inspection of product quality. This paper introduces the general structure of the computer vision inspection system, expounds the realization method of an on-line crack inspection system of glass bottles, which combines with neural network principle. The system’s ability to learn itself and adapt itself is very powerful, it has realized a quick and exact inspection of the on-line glass bottles’ crack successfully.

关键词： Product Quality Technique of Automated Visual Inspection Neural Network Image Collecting Image Processing

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Research on the Control Model of Coordinated Development wit...

Land use and landscape pattern change: a linkage to the construction of the Qinghai-Xizang Highway

工程和商业管理国际学术会议

作者： Zhang Xu 1. 2 , Wei Jian 2, 1., Zhao Ming 2 , Zhao Jiani 2 , du Lijuan 2 1. Donghua University, Shanghai, 201.20, China 2. Shanghai University of Engineering Science, Shanghai, 201.20, China

Taking producer service industry as research object, the approach to control of large scale system for coordinated development of producer service industry is presented and its corresponding mathematical model is established by applying theory and method of large scale systems through intentional analysis. The theoretical basis and evaluation method is provided for coordinated management of producer service industry, which is an important technique to promote the coordinated development of producer service industry.

关键词： service industry producer service industry large scale system control model coordinated development

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Journal of Geographical Sciences 2002年第3期12卷 253-265页

作者： YAN Jianzhong, ZHANG Yili, LIU Linshan, LIU Yanhua2, ZHENG du (1. Inst. of Geographic Sciences and Natural Resources Research, CAS, Beijing 1.01.1. China 2. The Ministry of Science and Technology, Beijing 1.01.1. China 3. College of Resources and Enviro Inst. of Geographic Sciences and Natural Resources Research CAS Beijing China College of Resources andEnvironment Southwest Agricultural University Chongqing China The Ministry of Science and Technology Beijing China

Based on digital land use data from 1.95 to 2000 and road data, the land use and landscape changes of Golmud, Qumaleb and Zhidoi are studied on a macro-scale. Land use and landscape changes in highway buffer zones and city expansion are special subjects. A new formula is used to define the exact degree of dynamic land use. To adequately define land use and landscape pattern changes, the buffer zones, illustrating the changes at different distances from the road, are recognized with ArcGIS 8.1.software. Prominent changes took place in land use and landscape patterns from 1.95 to 2000, and the area of built-up land increased by 323.8%. The comprehensive degree of dynamic land use is 2.25, and the degree of dynamic land use of built-up land is the highest, followed by cultivated land. Woodland has the lowest value. The used degree index of land resources declined by 38.8 from 1.95 to 2000. Landscape changed dramatically which influenced ecological processes immensely. Different from the corridor effect of other traffic routes, the corridor effect of this section of road is not obvious and its “point” radiation effect can be easily seen. The expanding range of Golmud City is confined to a 3 km buffer, while for Wudaoliang, it is 1.km. No land use change happened in the Nanshankou buffer.

关键词： land use change comprehensive index of the degree of land use diagnostic index of landscape degree of dynamic land use Qinghai-Xizang Highway

GUARANTEED COST CONTROL OF CONTINUOUS-TIME UNCERTAIN SINGULAR SYSTEM WITH BOTH STATE AND INPUT DELAYS

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Annals of Differential Equations 2009年第4期25卷 483-489页

作者： Hai Zhang 1.2 , Wei Jiang 1., Jun du 1.3 (1. School of Mathematical Sciences, Anhui University, Hefei 230039, 2. School of Math. and Computation Science, Anqing Teachers College, Anqing 24601., Anhui 3. Dept. of Math., Huainan Normal University, Huainan 232001. Anhui)

The guaranteed cost control problem for a continuous-time uncertain singular system with state and control delays, and a given quadratic cost function is studied in this paper. Sufficient conditions for the existence of the guaranteed cost controller are derived based on the linear inequality (LMI) approach. A parameterized characterization of the guaranteed cost laws is given in terms of the feasible solutions to a certain LMI, and the cost function of guaranteed cost controller exists an upper bound.

关键词： guaranteed cost control uncertain singular systems delays continuoustime systems LMI

Land cover changes based on plant successions: Deforestation, rehabilitation and degeneration of forest in the upper Dadu River watershed

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Science China Earth Sciences 2005年第12期48卷 2214-2230页

作者： YAN Jianzhong1.2,3, ZHANG Yili1. BAI Wanqi1. LIU Yanhua4, BAO Weikai5, LIU Linshan1. 2 & ZHENG du1.1. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 1.01.1. China 2. Graduate School of the Chinese Academy of Sciences, Beijing 1.0039, China 3. College of Resources and Environment, Southwest Agricultural University, Chongqing 40071., China 4. The Ministry of Science and Technology, P. C. China, Beijing 1.0862, China 5. Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 61.041. China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China Graduate School of the Chinese Academy of Sciences Beijing China College of Resources and Environment Southwest Agricultural University Chongqing China The Ministry of Science and Technology P. C. China Beijing China Chengdu Institute of Biology Chinese Academy of Sciences Chengdu China

To link regional land use/cover changes with environmental effects, land cover changes are required to reflect vegetation successions, whereas the land cover classification systems commonly used nowadays cannot serve this purpose. In this paper, a new land cover classification system is established in which land covers are classified by the vegetation succes-sions, taking Zamtang County, Barkam County and Jinchuan County in the upper Dadu River watershed as a study area. Using multi-temporal remote sensing images, the land cover data of 1.67, 1.86 and 2000 are obtained by means of integration of unsupervised classification and visual interpretation methods. The database facilitates the study of land use/cover changes, en-vironmental effects and ecological construction. Land cover changes reflect the main ecological processes in the upper Dadu River watershed. The landscape composed mainly of grasslands, wildwoods and alpine scrubs in 1.67 was changed to that of grasslands, secondary forests, al-pine scrubs, fragmentary wildwoods, artificial forests, secondary scrubs in 2000, meanwhile, the landscape got more fragmentized. The total area of the forests decreased by 9.43%. Study results have shown the process of restoration of logged areas in forest centers. From 1.67 to 2000, only 6.86 percents of logged areas were converted to shrubs, meadows or crop-lands, and the rest were converted into artificial forests or secondary forests. So the ecological shelter functions will be restored, stage by stage. Firewood collection, charcoal production and overgrazing are the three major triggers for the extensive degradation of alpine oak forests, Sa-bina tibetica forests and meadows. The arid valley grasslands expanded too. The degradation of vegetation in the southern slopes impairs ecological shelter functions and affects livelihood of local residents, so it is essential to find effective measures for ecological restoration and recon-struction. Field investigations have found

关键词： land use/cover classification, upper Dadu River watershed, vegetation successions, GIS, RS.

A Practical Regular LDPC Coded Scheme for Physical-Layer Information Security

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China Communications 2024年第5期21卷 190-201页

作者： du Junyi CETC Key Laboratory of Avionic Information System Southwest China Institute of Electronic TechnologyChengdu 610036China

In this paper,we aim to design a practical low complexity low-density parity-check(LDPC)coded scheme to build a secure open channel and protect information from *** this end,we first propose a punctured LDPC coded scheme,where the information bits in a codeword are punctured and only the parity check bits are transmitted to the *** further propose a notion of check node type distribution and derive multi-edge type extrinsic information transfer functions to estimate the security performance,instead of the well-known weak metric bit error *** optimize the check node type distribution in terms of the signal-to-noise ratio(SNR)gap and modify the progressive edge growth algorithm to design finite-length *** results show that our proposed scheme can achieve a lower computational complexity and a smaller security gap,compared to the existing scrambling and puncturing schemes.

关键词： extrinsic information transfer function physical layer scheme secure open channel security gap

Shared Control Teleoperation for Targets Acquisition

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Shared Control Teleoperation for Targets Acquisition

Transformer and GAN-Based Super-Resolution Reconstruction Network for Medical Images

第24届中国控制与决策会议

作者： WANG Dongli 1., LIU Huaping 2 , SUN Fuchun 2 , du Yonggui 1.1. Automation college of information engineering, Taiyuan university of technology, Taiyuan 030024, china2. Tsinghua national laboratory for information science and technology,state key laboratory of intelligent technology and systems,department of computer science and technology,tsinghua university,Beijing 1.0084,china

It is very difficult to capture the target in the microgravity environment, simply by relying on ground operators. Based on shared control theory, this paper effectively combines the decision-making ability of ground operators and the independent ability of space robot, through making full use of independent control ability of the space robot, and reducing operators’ workload and working time, to achieve more valid capture for targets. Shared control is more accurate capture of the target compared with teleoperation in experimental.

关键词： Space robots Shared control Target acquisition Independent grab

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Tsinghua Science and Technology 2024年第1期29卷 197-206页

作者： Weizhi du Shihao Tian Arts&Sciences College Washington University in St.LouisSt.LouisMO 63130USA Department of Electric and Computing Engineering Cornell UniversityIthacaNY 14850USA

Super-resolution reconstruction in medical imaging has become more demanding due to the necessity of obtaining high-quality images with minimal radiation dose,such as in low-field magnetic resonance imaging(MRI).However,image super-resolution reconstruction remains a difficult task because of the complexity and high textual requirements for diagnosis *** this paper,we offer a deep learning based strategy for reconstructing medical images from low resolutions utilizing Transformer and generative adversarial networks(T-GANs).The integrated system can extract more precise texture information and focus more on important locations through global image matching after successfully inserting Transformer into the generative adversarial network for picture ***,we weighted the combination of content loss,adversarial loss,and adversarial feature loss as the final multi-task loss function during the training of our proposed model *** comparison to established measures like peak signal-to-noise ratio(PSNR)and structural similarity index measure(SSIM),our suggested T-GAN achieves optimal performance and recovers more texture features in super-resolution reconstruction of MRI scanned images of the knees and belly.

关键词： super-resolution image reconstruction Transformer generative adversarial network(GAN)