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Optimal and suboptimal structured algorithms of binary linear block codes

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Journal of Systems Engineering and Electronics 2011年第6期22卷 1010-1014页

作者： yijun Luo Jin li School of Electronic Information Wuhan University Wuhan 430079 R R. China

The optimal and suboptimal structured algorithms of linear block codes from the geometrical perspective are *** minimum distance and weight property lemmas and the theorem are proved for the generator *** upon the property of generator matrix,the structured algorithms of linear block codes are *** the complexity of optimal structured algorithm is very high,the binary linear block codes is searched by using the suboptimal structured *** comparison with Bose-Chaudhuri-Hocquenqhem（BCH） codes shows that the searched linear block codes are equivalent on minimum distance and can be designed for more block *** the linear block codes are used widely in communication systems and digital applications,the optimal and suboptimal structured algorithms must have great future being widely used in many applications and perspectives.

关键词： channel coding linear block codes generator matrix minimum distance.

Improved algorithms to plan missions for agile earth observation satellites

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Journal of Systems Engineering and Electronics 2014年第5期25卷 811-821页

作者： Huicheng Hao Wei Jiang yijun li Research Center of Information Management and Information Systems Harbin Institute of Technology School of Engineering Northeast Agricultural University

This study concentrates of the new generation of the agile （AEOS）. AEOS is a key study object on management problems earth observation satellite in many countries because of its many advantages over non-agile satellites. Hence, the mission planning and scheduling of AEOS is a popular research problem. This research investigates AEOS characteristics and establishes a mission planning model based on the working principle and constraints of AEOS as per analysis. To solve the scheduling issue of AEOS, several improved algorithms are developed. Simulation results suggest that these algorithms are effective.

关键词： mission planning immune clone algorithm hybrid genetic algorithm (EA) improved ant colony algorithm general particle swarm optimization (PSO) agile earth observation satellite (AEOS).

Robust control of hand wheel torque for active front steering system

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Science China(Technological Sciences) 2015年第1期58卷 107-116页

作者： ZHAO WanZhong li yijun WANG ChunYan College of Energy & Power Engineering Nanjing University of Aeronautics and Astronautics

Active front steering(AFS)system has been used as a promising technology which improves the steering portability and handing stability of *** employs a steering motor to realize the functions of variable steering ratio and vehicle stability ***,it has a serious problem of unexpected reaction hand wheel torque caused by the additional steering *** this paper,the optimum hand wheel torque is designed based on the linear tire *** the uncertainty and disturbance of the steering system and vehicle,an H∞controller is developed to make sure the hand wheel torque follows the reference torque accurately and *** simulation shows that the proposed controller can compensate the unnatural reaction torque and provide a good steering feel for the driver.

关键词： active front steering variable steering ratio hand wheel torque H∞ control steering feel

Integrated optimization of multiproduct multiperiod transportation and inventory under a carbon cap constraint for online retailers

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Transportation Safety and Environment 2021年第3期3卷 291-303页

作者： Yaorong Cheng yijun li School of Traffic&Transportation Engineering Central South UniversityChangsha 410075China

This study aims to solve the problem of multiproduct multiperiod integrated transportation and inventory optimization for online retailers.A carbon cap constraint and multitype of capacitated trucks are simultaneously incorporated into the proposed mixed-integer program.A simulated annealing(SA)algorithm is *** 12.9.0 is used to solve the submodel obtained from the neighbourhood search and is also used to get the optimal solutions for *** results show that the simulated annealing algorithm can find satisfactory solutions within a reasonable *** the problem size increases,the growth of the computational time of the SA algorithm is significantly smaller than that of the CPLEX.A sensitivity analysis for the carbon cap is also *** results indicate that if the carbon cap is gradually tightened,the total cost increases first with a gentle slope,and then with a remarkable slope,same as for the total number of trucks used;the total carbon emissions first decrease with a gentle slope,and then decline with a significant *** the carbon cap is strict,only a few different types of trucks will be *** percentage changes of the total cost increase and the total carbon emission reduction are also *** the allowed carbon emissions are gradually reduced,situation of a higher amount of carbon emission reduction and a lower amount of cost increase can be ***,using multiple types of trucks in the integrated optimization of transportation and inventory decisions can achieve greater cost savings with lower increments of carbon emission.

关键词： integrated optimization multiperiod multiproduct carbon emission simulated annealing

Semantic-Oriented Sentiment Classification for Chinese Product Reviews: An Experimental Study of Book and Cell Phone Reviews

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Tsinghua Science and Technology 2005年第z1期10卷 797-802页

作者： YE Qiang li yijun ZHANG Yiwen School of Management Harbin Institute of Technology Harbin 150001 China School of Management Harbin Institute of Technology Harbin 150001 China Department of Management Information Systems University of Arizona Tucson 85705 U.S.A.

Sentiment classification is an automatic opinion classification method to classify the product reviews on web into positive or negative opinions to help consumers or sellers to understand the opinions and evaluations from existing customers. Semantic-oriented approach is one of the recent developments in sentiment classification. Up to now, most research of sentiment classification is on English reviews,and little work has been done on Chinese reviews using sentiment classification. The detailed techniques used in English review cannot be applied directly to Chinese reviews due to the different characteristics between these two languages. This study modified and improved the semantic-oriented approach to a 6-step process for Chinese review, focusing on the modification and improvement on the text segmentation and reference words pairs (RWPs) identification. Two experiments were conducted on book reviews and cell phone reviews. The results show that the performances of the proposed approach are comparable to those of the existing English reviews classification studies.

关键词： sentiment classification Chinese customer reviews books cell phones semantic orientation

Solid-state mechanochemistry advancing two dimensional materials for lithium-ion storage applications:A mini review

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维普期刊数据库

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Nano Materials Science 2023年第2期5卷 210-227页

作者： Xingang liu Wenbin Kang Xi li li Zeng yijun li Qi Wang Chuhong Zhang State Key Laboratory of Polymer Materials Engineering Polymer Research InstituteSichuan UniversityChengdu610065China

The vigorous development of two-dimensional(2D)materials brings about numerous opportunities for lithiumion batteries(liBs)due to their unique 2D layered structure,large specific surface area,outstanding mechanical and flexibility properties,*** technologies for production of 2D materials include but are not limited to mechanochemical(solid-state/liquid-phase)exfoliation,the solvothermal method and chemical vapor *** this review,strategies leading to the production of 2D materials via solid-state mechanochemistry featuring traditional high energy ball-milling and Sichuan University patented pan-milling are *** mechanism involving exfoliation,edge selective carbon radical generation of the 2D materials is delineated and this is followed by detailed discussion on representative mechanochemical techniques for tailored and improved lithium-ion storage *** the light of the advantages of the solid-state mechanochemical method,there is great promise for the commercialization of 2D materials for the next-generation high performance liBs.

关键词： Two-dimensional materials Solid-state mechanochemistry Ball-milling Pan-milling lithium-ion batteries

Computational Methods for Single-cell Multi-omics Integration and Alignment

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Genomics, Proteomics & Bioinformatics 2022年第5期20卷 836-849页

作者： Stefan Stanojevic yijun li Aleksandar Ristivojevic Lana X.Garmire Department of Computational Medicine and Bioinformatics University of MichiganAnn ArborMI 48109USA Department of Biostatistics University of MichiganAnn ArborMI 48109USA Amherst College AmherstMA 01002USA

Recently developed technologies to generate single-cell genomic data have made a revolutionary impact in the field of ***-omics assays offer even greater opportunities to understand cellular states and biological *** problem of integrating different omics data with very different dimensionality and statistical properties remains,however,quite challenging.A growing body of computational tools is being developed for this task,leveraging ideas ranging from machine translation to the theory of networks,and represents another frontier on the interface of biology and data *** goal in this review is to provide a comprehensive,up-to-date survey of computational techniques for the integration of single-cell multi-omics data,while making the concepts behind each algorithm approachable to a non-expert audience.

关键词： Single-cell Multi-omics Machine learning Unsupervised learning Integration

A Volumetric Model for Evaluating Tight Sandstone Gas Reserves in the Permian Sulige Gas Field,Ordos Basin,Central China

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Acta Geologica Sinica(English Edition) 2019年第2期93卷 386-399页

作者： CUI Mingming FAN Aiping WANG Zongxiu GAO Wanli li Jinbu li yijun Key Laboratory of Shale oil and Gas Geological Survey Institute of Geomechanics Chinese Academy of Geological Sciences College of Geological Science & Engineering Shandong University of Science and Technology Institute of Exploration and Development Changqing Oilfield Company Petrochina

To accurately measure and evaluate reserves is critical for ensuring successful production of unconventional oil and gas. This work proposes a volumetric model to evaluate the tight sandstone gas reserves of the Permian Sulige gas field in the Ordos Basin. The reserves can be determined by four major parameters of reservoir cutoffs, net pay, gas-bearing area and compression factor Z, which are controlled by reservoir characteristics and sedimentation. Well logging, seismic analysis, core analysis and gas testing, as well as thin section identification and SEM analysis were used to analyze the pore evolution and pore-throat structure. The porosity and permeability cutoffs are determined by distribution function curve,empirical statistics and intersection plot. Net pay and gas-bearing area are determined based on the cutoffs, gas testing and sand body distribution, and the compression factor Z is obtained by gas component. The results demonstrate that the reservoir in the Sulige gas field is characterized by ultralow porosity and permeability, and the cutoffs of porosity and permeability are 5% and 0.15×10^(–3) μm^2, respectively. The net pay and gas-bearing area are mainly affected by the sedimentary facies, sand body types and distribution. The gas component is dominated by methane which accounts for more than 90%, and the compression factor Z of H_8(P_2h_8) and S_1(P_1s_1) are 0.98 and 0.985, respectively. The distributary channels stacked and overlapped, forming a wide and thick sand body with good developed intergranular pores and intercrystalline pores. The upper part of channel sand with good porosity and permeability can be sweet spot for gas exploration. The complete set of calculation systems proposed for tight gas reserve calculation has proved to be effective based on application and feedback. This model provides a new concept and consideration for reserve prediction and calculation in other areas.

关键词： tight sandstone reservoir volumetric gas reserve Permian Sulige gas field Ordos Basin

Detailed sedimentary facies of a sandstone reservoir in the eastern zone of the Sulige gas field, Ordos Basin

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Mining Science and Technology 2010年第6期20卷 891-897,903页

作者： li yijun ZHAO Yong YANG Renchao FAN Aiping li Fuping Sulige Gas Field Research Center Changqing Oilfield Company Xi "an 710018 China College of Geological Science and Engineering Shandong University of Science and Technology Qingdao 266510 China

Given sustaining exploration, the eastern zone of the Sulige gas field may soon become a key area of exploitation. In order to explore its genesis, types and distribution of the reservoir sandstones in the eastern zone of this gas field, we focused in our study on the provenance and detailed sedimentary facies of sandstone of the He8 （the eighth part of the Shihezi formation, Permian system） and Shanxil （the first part of the Shanxi formation, Permian system） members, based on core observations, analyses in petrography, granularity and logging. The results show that： 1） the sandstone provenance of Shanxil and He8 in the eastern zone of the Sulige gas field is from the north of the Ordos Basin, characterized by dual directions from the north and northeast. 2） The He8 and Shanxil members were deposited in a fluvial-delta sedimentary system. The He8 was mainly deposited in braided rivers, in- cluding braided channels, channel bars, levee and floodplain sub-environments, whereas the Shanxil Member was deposited in braided rivers and deltas, including braided channels, channel bars, floodplains, tributaries and inter-tributary sub-environments. 3） Sedimentary facies bands migrated in drastic fashion towards the basin from the Shanxil to the He8 Member. Base levels of sedi- mentation generally present a trend of small increases in-amplitude, large decreasing amplitudes and slow and gradual Increases. 4） The continuity of the reservoir sandbodies along the source direction is better than that perpendicular to the direction. Compared with Shanxil, both dimensions and continuity of the sandbodies in He8 are better from which we conclude that it is the most fa- vorable part of the reservoir.

关键词： Ordos Basin Sulige gas field Permian sandstone reservoir detailed sedimentary facies