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Multilevel analysis of the central-peripheral-target organ pathway:contributing to recovery after peripheral nerve injury
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作者 Xizi Song Ruixin Li +6 位作者 Xiaolei Chu Qi Li Ruihua Li Qingwen Li Kai-Yu Tong Xiaosong Gu Dong Ming 《Neural Regeneration Research》 SCIE CAS 2025年第10期2807-2822,共16页
Peripheral nerve injury is a common neurological condition that often leads to severe functional limitations and disabilities.Research on the pathogenesis of peripheral nerve injury has focused on pathological changes... Peripheral nerve injury is a common neurological condition that often leads to severe functional limitations and disabilities.Research on the pathogenesis of peripheral nerve injury has focused on pathological changes at individual injury sites,neglecting multilevel pathological analysis of the overall nervous system and target organs.This has led to restrictions on current therapeutic approaches.In this paper,we first summarize the potential mechanisms of peripheral nerve injury from a holistic perspective,covering the central nervous system,peripheral nervous system,and target organs.After peripheral nerve injury,the cortical plasticity of the brain is altered due to damage to and regeneration of peripheral nerves;changes such as neuronal apoptosis and axonal demyelination occur in the spinal cord.The nerve will undergo axonal regeneration,activation of Schwann cells,inflammatory response,and vascular system regeneration at the injury site.Corresponding damage to target organs can occur,including skeletal muscle atrophy and sensory receptor disruption.We then provide a brief review of the research advances in therapeutic approaches to peripheral nerve injury.The main current treatments are conducted passively and include physical factor rehabilitation,pharmacological treatments,cell-based therapies,and physical exercise.However,most treatments only partially address the problem and cannot complete the systematic recovery of the entire central nervous system-peripheral nervous system-target organ pathway.Therefore,we should further explore multilevel treatment options that produce effective,long-lasting results,perhaps requiring a combination of passive(traditional)and active(novel)treatment methods to stimulate rehabilitation at the central-peripheral-target organ levels to achieve better functional recovery. 展开更多
关键词 central nervous system central peripheral target organ multilevel pathological analysis nerve regeneration peripheral nerve injury peripheral nervous system target organs therapeutic approach
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Design of Serially Concatenated Two-Level Polar Coded Modulation System with Low-Complexity
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作者 Zhou Lin Liao Guojun +3 位作者 Xu Lei An Ran Xie Xianzhong Wang Xi 《China Communications》 2025年第1期102-110,共9页
Multilevel coding(MLC)is a commonly used polar coded modulation scheme,but challenging to implement in engineering due to its high complexity and long decoding delay for high-order modulations.To address these limitat... Multilevel coding(MLC)is a commonly used polar coded modulation scheme,but challenging to implement in engineering due to its high complexity and long decoding delay for high-order modulations.To address these limitations,a novel two-level serially concatenated MLC scheme,in which the bitlevels with similar reliability are bundled and transmitted together,is proposed.The proposed scheme hierarchically protects the two bit-level sets:the bitlevel sets at the higher level are sufficiently reliable and do not require excessive resources for protection,whereas only the bit-level sets at the lower level are encoded by polar codes.The proposed scheme has the advantages of low power consumption,low delay and high reliability.Moreover,an optimized constellation signal labeling rule that can enhance the performance is proposed.Finally,the superiority of the proposed scheme is validated through the theoretical analysis and simulation results.Compared with the bit interleaving coding modulation(BICM)scheme,under 256-quadrature amplitude modulation(QAM),the proposed scheme attains a performance gain of 1.0 dB while reducing the decoding complexity by 54.55%. 展开更多
关键词 bit-interleaved coded modulation high-order modulation multilevel coding polar codes
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Multilevel carbon architecture of subnanoscopic silicon for fast‐charging high‐energy‐density lithium‐ion batteries 被引量:1
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作者 Meisheng Han Yongbiao Mu +2 位作者 Lei Wei Lin Zeng Tianshou Zhao 《Carbon Energy》 SCIE EI CAS CSCD 2024年第4期256-268,共13页
Silicon(Si)is widely used as a lithium‐ion‐battery anode owing to its high capacity and abundant crustal reserves.However,large volume change upon cycling and poor conductivity of Si cause rapid capacity decay and p... Silicon(Si)is widely used as a lithium‐ion‐battery anode owing to its high capacity and abundant crustal reserves.However,large volume change upon cycling and poor conductivity of Si cause rapid capacity decay and poor fast‐charging capability limiting its commercial applications.Here,we propose a multilevel carbon architecture with vertical graphene sheets(VGSs)grown on surfaces of subnanoscopically and homogeneously dispersed Si–C composite nanospheres,which are subsequently embedded into a carbon matrix(C/VGSs@Si–C).Subnanoscopic C in the Si–C nanospheres,VGSs,and carbon matrix form a three‐dimensional conductive and robust network,which significantly improves the conductivity and suppresses the volume expansion of Si,thereby boosting charge transport and improving electrode stability.The VGSs with vast exposed edges considerably increase the contact area with the carbon matrix and supply directional transport channels through the entire material,which boosts charge transport.The carbon matrix encapsulates VGSs@Si–C to decrease the specific surface area and increase tap density,thus yielding high first Coulombic efficiency and electrode compaction density.Consequently,C/VGSs@Si–C delivers excellent Li‐ion storage performances under industrial electrode conditions.In particular,the full cells show high energy densities of 603.5 Wh kg^(−1)and 1685.5 Wh L^(−1)at 0.1 C and maintain 80.7%of the energy density at 3 C. 展开更多
关键词 fast charging high energy densities lithium‐ion batteries multilevel carbon architecture subnanoscopic silicon anode
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Aerodynamic/stealth design of S-duct inlet based on discrete adjoint method 被引量:1
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作者 Jun DENG Ke ZHAO +4 位作者 Lin ZHOU Wei ZHANG Bowen SHU Jiangtao HUANG Zhenghong GAO 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第4期725-746,共22页
It is a major challenge for the airframe-inlet design of modern combat aircrafts,as the flow and electromagnetic wave propagation in the inlet of stealth aircraft are very complex.In this study,an aerodynamic/stealth ... It is a major challenge for the airframe-inlet design of modern combat aircrafts,as the flow and electromagnetic wave propagation in the inlet of stealth aircraft are very complex.In this study,an aerodynamic/stealth optimization design method for an S-duct inlet is proposed.The upwind scheme is introduced to the aerodynamic adjoint equation to resolve the shock wave and flow separation.The multilevel fast multipole algorithm(MLFMA)is utilized for the stealth adjoint equation.A dorsal S-duct inlet of flying wing layout is optimized to improve the aerodynamic and stealth characteristics.Both the aerodynamic and stealth characteristics of the inlet are effectively improved.Finally,the optimization results are analyzed,and it shows that the main contradiction between aerodynamic characteristics and stealth characteristics is the centerline and crosssectional area.The S-duct is smoothed,and the cross-sectional area is increased to improve the aerodynamic characteristics,while it is completely opposite for the stealth design.The radar cross section(RCS)is reduced by phase cancelation for low frequency conditions.The method is suitable for the aerodynamic/stealth design of the aircraft airframe-inlet system. 展开更多
关键词 S-duct inlet aerodynamic/stealth optimization design discrete adjoint upwind scheme multilevel fast multipole algorithm(MLFMA)
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Harmonic Impedance Modeling and Oscillation Analysis of Modular Multilevel Converter
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作者 Wang Yuhong Chen Wensheng +2 位作者 Gao Shilin Liao Jianquan Cheng Yangfan 《系统仿真学报》 CAS CSCD 北大核心 2024年第12期2755-2770,共16页
To facilitate rapid analysis of the oscillation stability mechanism in modular multilevel converter-based high voltage direct current(MMC-HVDC)systems and streamline the simulation process for determining MMC impedanc... To facilitate rapid analysis of the oscillation stability mechanism in modular multilevel converter-based high voltage direct current(MMC-HVDC)systems and streamline the simulation process for determining MMC impedance characteristics,a simplified mathematical simulation model for MMC closed-loop impedance is developed using the harmonic state space method.This model considers various control strategies and includes both AC-side and DC-side impedance models.By applying a Nyquist criterion-based impedance analysis method,the stability mechanisms on the AC and DC sides of the MMC are examined.In addition,a data-driven oscillation stability analysis method is also proposed,leveraging a global sensitivity algorithm based on fast model results to identify key parameters influencing MMC oscillation stability.Based on sensitivity analysis results,a parameter adjustment strategy for oscillation suppression is proposed.The simulation results from the MATLAB/Simulinkbased MMC model validate the effectiveness of the proposed method. 展开更多
关键词 modular multilevel converter impedance modeling harmonic state space global sensitivity impedance analysis
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The advantages of multi-level omics research on stem cell-based therapies for ischemic stroke
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作者 Yiqing Wang Chuheng Chang +2 位作者 Renzhi Wang Xiaoguang Li Xinjie Bao 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第9期1998-2003,共6页
Stem cell transplantation is a potential therapeutic strategy for ischemic stroke. However, despite many years of preclinical research, the application of stem cells is still limited to the clinical trial stage. Altho... Stem cell transplantation is a potential therapeutic strategy for ischemic stroke. However, despite many years of preclinical research, the application of stem cells is still limited to the clinical trial stage. Although stem cell therapy can be highly beneficial in promoting functional recovery, the precise mechanisms of action that are responsible for this effect have yet to be fully elucidated. Omics analysis provides us with a new perspective to investigate the physiological mechanisms and multiple functions of stem cells in ischemic stroke. Transcriptomic, proteomic, and metabolomic analyses have become important tools for discovering biomarkers and analyzing molecular changes under pathological conditions. Omics analysis could help us to identify new pathways mediated by stem cells for the treatment of ischemic stroke via stem cell therapy, thereby facilitating the translation of stem cell therapies into clinical use. In this review, we summarize the pathophysiology of ischemic stroke and discuss recent progress in the development of stem cell therapies for the treatment of ischemic stroke by applying multi-level omics. We also discuss changes in RNAs, proteins, and metabolites in the cerebral tissues and body fluids under stroke conditions and following stem cell treatment, and summarize the regulatory factors that play a key role in stem cell therapy. The exploration of stem cell therapy at the molecular level will facilitate the clinical application of stem cells and provide new treatment possibilities for the complete recovery of neurological function in patients with ischemic stroke. 展开更多
关键词 ischemic stroke mesenchymal stem cells metabolomics multilevel omics neural stem/progenitor cells NEUROINFLAMMATION PATHOPHYSIOLOGY proteomics stem cell therapy TRANSCRIPTOMES
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On the Use of Monotonicity-Preserving Interpolatory Techniques in Multilevel Schemes for Balance Laws
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作者 Antonio Baeza Rosa Donat Anna Martinez-Gavara 《Communications on Applied Mathematics and Computation》 EI 2024年第2期1319-1341,共23页
Cost-effective multilevel techniques for homogeneous hyperbolic conservation laws are very successful in reducing the computational cost associated to high resolution shock capturing numerical schemes.Because they do ... Cost-effective multilevel techniques for homogeneous hyperbolic conservation laws are very successful in reducing the computational cost associated to high resolution shock capturing numerical schemes.Because they do not involve any special data structure,and do not induce savings in memory requirements,they are easily implemented on existing codes and are recommended for 1D and 2D simulations when intensive testing is required.The multilevel technique can also be applied to balance laws,but in this case,numerical errors may be induced by the technique.We present a series of numerical tests that point out that the use of monotonicity-preserving interpolatory techniques eliminates the numerical errors observed when using the usual 4-point centered Lagrange interpolation,and leads to a more robust multilevel code for balance laws,while maintaining the efficiency rates observed forhyperbolic conservation laws. 展开更多
关键词 Hyperbolic balance laws Well-balanced schemes Multilevel schemes Harten's multiresolution
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Multistage seismic damage constitutive model and parameter calibration of reinforced concrete columns
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作者 Xing Chenxi Shu Yiwei +1 位作者 Zhu Xiaojie Zhong Jian 《Journal of Southeast University(English Edition)》 EI CAS 2024年第4期386-395,共10页
The road traffic network contains a large number of bridges,and calculating bridge damage using refined models demands significant time and resources.Therefore,developing a rapid evaluation method for the seismic capa... The road traffic network contains a large number of bridges,and calculating bridge damage using refined models demands significant time and resources.Therefore,developing a rapid evaluation method for the seismic capacity of regular bridges has become a crucial scientific challenge.This study presents an approach in which the ductile column is represented by a single degree-of-freedom model with elastic-plastic constitutive characteristics.Utilizing an uncoupled multivariate power function model and a plastic hinge model,a multidimensional power function model for section hierarchical curvature is constructed.Subsequently,the seismic multistage damage constitutive model(SMSD-CM)of member hierarchy is deduced and calibrated through theoretical methods.This model efficiently derives the trilinear constitutive model of components by inputting several crucial parameters.The SMSD-CM accurately simulates the hysteretic curve and displacement time-history under actual seismic conditions and aligns well with pushover analysis results from tests.The efficiency,ease of operation,and accuracy make the model suitable for rapid evaluation of the seismic capacity of regular bridges within the road traffic network. 展开更多
关键词 moment-curvature analysis fragility analysis curvature ductility seismic multilevel damage trilinear model
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Stock trend prediction method coupled with multilevel indicators
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作者 Liu Yu Pan Yuting Liu Xiaoxing 《Journal of Southeast University(English Edition)》 EI CAS 2024年第4期425-431,共7页
To systematically incorporate multiple influencing factors,the coupled-state frequency memory(Co-SFM)network is proposed.This model integrates Copula estimation with neural networks,fusing multilevel data information,... To systematically incorporate multiple influencing factors,the coupled-state frequency memory(Co-SFM)network is proposed.This model integrates Copula estimation with neural networks,fusing multilevel data information,which is then fed into downstream learning modules.Co-SFM employs an upstream fusion module to incorporate multilevel data,thereby constructing a macro-plate-micro data structure.This configuration helps identify and integrate characteristics from different data levels,facilitating a deeper understanding of the internal links within the financial system.In the downstream model,Co-SFM uses a state-frequency memory network to mine hidden frequency information within stock prices,and the multifrequency patterns of sequential data are modeled.Empirical results show that Co-SFM s prediction accuracy for stock price trends is significantly better than that of other models.This is especially evident in multistep medium and long-term trend predictions,where integrating multilevel data results in notably improved accuracy. 展开更多
关键词 stock trend prediction multilevel indicators COPULA state-frequency memory network
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Application of Power Electronics Converters in Renewable Energy
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作者 Tao Cheng 《Journal of Electronic Research and Application》 2024年第4期101-107,共7页
Against the backdrop of global energy shortages and increasingly severe environmental pollution,renewable energy is gradually becoming a significant direction for future energy development.Power electronics converters... Against the backdrop of global energy shortages and increasingly severe environmental pollution,renewable energy is gradually becoming a significant direction for future energy development.Power electronics converters,as the core technology for energy conversion and control,play a crucial role in enhancing the efficiency and stability of renewable energy systems.This paper explores the basic principles and functions of power electronics converters and their specific applications in photovoltaic power generation,wind power generation,and energy storage systems.Additionally,it analyzes the current innovations in high-efficiency energy conversion,multilevel conversion technology,and the application of new materials and devices.By studying these technologies,the aim is to promote the widespread application of power electronics converters in renewable energy systems and provide theoretical and technical support for achieving sustainable energy development. 展开更多
关键词 Power electronics converters Renewable energy Photovoltaic power generation Wind power generation Energy storage systems High-efficiency energy conversion Multilevel conversion New materials New devices
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A Mode Research of Straw Recycling Based on Circular Agriculture Theory 被引量:11
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作者 冯伟 张利群 +2 位作者 何龙娟 庞中伟 郭淑珍 《Agricultural Science & Technology》 CAS 2011年第12期1921-1924,共4页
Recycling of crop residues resources has become an urgent problem to be addressed in agriculture and rural areas of China.Compared to single use patterns of crop residues resources,crop residues circular agriculture c... Recycling of crop residues resources has become an urgent problem to be addressed in agriculture and rural areas of China.Compared to single use patterns of crop residues resources,crop residues circular agriculture characterized by multi-grade utilization and recycling is more important to improve the added value of crop residues,to enhance product market competitiveness,and to promote scale development and industrialization of crop residues recycling.This paper discussed the basic principles of the development of crop residues circular agriculture mode,and summarized five main crop residues circular agriculture mode. 展开更多
关键词 Crop straw Circular agriculture Multilevel utilization Circular utilization MODE
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Defect image segmentation using multilevel thresholding based on firefly algorithm with opposition-learning 被引量:3
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作者 陈恺 戴敏 +2 位作者 张志胜 陈平 史金飞 《Journal of Southeast University(English Edition)》 EI CAS 2014年第4期434-438,共5页
To segment defects from the quad flat non-lead QFN package surface a multilevel Otsu thresholding method based on the firefly algorithm with opposition-learning is proposed. First the Otsu thresholding algorithm is ex... To segment defects from the quad flat non-lead QFN package surface a multilevel Otsu thresholding method based on the firefly algorithm with opposition-learning is proposed. First the Otsu thresholding algorithm is expanded to a multilevel Otsu thresholding algorithm. Secondly a firefly algorithm with opposition-learning OFA is proposed.In the OFA opposite fireflies are generated to increase the diversity of the fireflies and improve the global search ability. Thirdly the OFA is applied to searching multilevel thresholds for image segmentation. Finally the proposed method is implemented to segment the QFN images with defects and the results are compared with three methods i.e. the exhaustive search method the multilevel Otsu thresholding method based on particle swarm optimization and the multilevel Otsu thresholding method based on the firefly algorithm. Experimental results show that the proposed method can segment QFN surface defects images more efficiently and at a greater speed than that of the other three methods. 展开更多
关键词 quad flat non-lead QFN surface defects opposition-learning firefly algorithm multilevel Otsu thresholding algorithm
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RCS测试中的低散射载体设计及仿真分析 被引量:7
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作者 梁爽 刘庆杰 +2 位作者 聂暾 郭文 张斌 《计算机测量与控制》 2017年第8期104-107,111,共5页
在雷达散射截面(RCS)测试中,低散射载体的设计结果取决于被测目标的RCS量级;为进行细节性隐身设计,获得台阶与缝隙排除载体干扰后的RCS水平,提出一种在台阶与缝隙RCS测试中的低散射载体设计方法;采用多层快速多极子算法,对低散射载体相... 在雷达散射截面(RCS)测试中,低散射载体的设计结果取决于被测目标的RCS量级;为进行细节性隐身设计,获得台阶与缝隙排除载体干扰后的RCS水平,提出一种在台阶与缝隙RCS测试中的低散射载体设计方法;采用多层快速多极子算法,对低散射载体相邻曲面连接方式、台阶与缝隙在载体上的位置、前缘尖削度、倒圆半径对散射特性的影响进行仿真分析;仿真计算结果表明,控制载体表面曲率的变化、加大前缘尖削度、减小拼接曲面倒圆半径能有效降低载体前向散射水平,由于载体曲面一侧的散射水平低于平面一侧散射水平,台阶与缝隙特征应位于曲面上;对RCS测试中低散射载体设计具有指导意义。 展开更多
关键词 雷达散射截面 多层快速多极子算法 低散射载体 电磁散射 隐身设计 radar cross section (RCS) MULTILEVEL fast MULTIPOLE algorithm (MLFMA)
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基于Multilevel CodingTree模型的公路数字化档案标识编码研究 被引量:8
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作者 罗竟 唐修益 +4 位作者 黄汝维 陈宁江 闫承鑫 刘晓东 高爱乐 《档案与建设》 北大核心 2015年第8期13-19,31,共8页
针对高速公路信息化建设中的编码问题,文章提出了基于Multilevel Coding Tree模型的"项目代号+属性+类别+流水号"四段位编码方案。根据该编码的结构,采用概率分析、实验测试和命题证明等手段,验证了编码的唯一性。该编码方案... 针对高速公路信息化建设中的编码问题,文章提出了基于Multilevel Coding Tree模型的"项目代号+属性+类别+流水号"四段位编码方案。根据该编码的结构,采用概率分析、实验测试和命题证明等手段,验证了编码的唯一性。该编码方案为公路信息化建设中各类文件提供了唯一的编码,达到一页(件)一码,是一种行之有效的编码方案。 展开更多
关键词 高速公路 工程档案 标识编码 MULTILEVEL CodingTree
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AUTOMATIC MULTILEVEL THRESHOLDING METHOD BASED ON MAXIMUM ENTROPY 被引量:2
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作者 曹力 史忠科 郑家伟 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2005年第4期335-338,共4页
In the multilevel thresholding segmentation of the image, the classification number is always given by the supervisor. To solve this problem, a fast multilevel thresholding algorithm considering both the threshold val... In the multilevel thresholding segmentation of the image, the classification number is always given by the supervisor. To solve this problem, a fast multilevel thresholding algorithm considering both the threshold value and the classification number is proposed based on the maximum entropy, and the self-adaptive criterion of the classification number is given. The algorithm can obtain thresholds and automatically decide the classification number. Experimental results show that the algorithm is effective. 展开更多
关键词 multilevel thresholding maximum entropy classification number nonparametric method
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STUDY AND IMPROVEMENT OF MLS RELATIONAL DATA MODEL
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作者 王立松 丁秋林 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2003年第2期236-242,共7页
The conception of multilevel security (MLS) is commonly used in the study of data model for secure database. But there are some limitations in the basic MLS model, such as inference channels. The availability and data... The conception of multilevel security (MLS) is commonly used in the study of data model for secure database. But there are some limitations in the basic MLS model, such as inference channels. The availability and data integrity of the system are seriously constrained by it′s 'No Read Up, No Write Down' property in the basic MLS model. In order to eliminate the covert channels, the polyinstantiation and the cover story are used in the new data model. The read and write rules have been redefined for improving the agility and usability of the system based on the MLS model. All the methods in the improved data model make the system more secure, agile and usable. 展开更多
关键词 data model multilevel secure database covert channels POLYINSTANTIATION cover story
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A Fuzzy Satisfactory Method for Decentralized Bi Level Linear Programming
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作者 刘新旺 达庆利 《Journal of Southeast University(English Edition)》 EI CAS 1998年第1期102-107,共6页
Based on the theory of fuzzy decision making, a two phrase approach is proposed for the decentralized bi level linear programming problem(DBLPP). The approach considers the conflicts between the upper and lower leve... Based on the theory of fuzzy decision making, a two phrase approach is proposed for the decentralized bi level linear programming problem(DBLPP). The approach considers the conflicts between the upper and lower levels decision makers (DMs), and among the lower level DMs themselves, a satisfactory solution is got with the non conflict matrix and decision power distribution. Compared with the other methods that have ever been proposed, the solution process is more fit to a kind of real decision making processes. 展开更多
关键词 multilevel programming fuzzy optimization satisfactory solution Pareto optimum
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Risk Assessment of Diary Cattle Brucellosis Based on Systematic Multilevel Grey Relation Entropy Method
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作者 孙向东 江慎铭 刘拥军 《Agricultural Science & Technology》 CAS 2012年第10期2169-2174,2225,共7页
[Objective] The study was to explore the major factors affecting diary cattle brucellosis risk assessment,as well as their strong-to-weak sequence,so as to provide theoretical basis for assessing diary cattle brucello... [Objective] The study was to explore the major factors affecting diary cattle brucellosis risk assessment,as well as their strong-to-weak sequence,so as to provide theoretical basis for assessing diary cattle brucellosis risk level in different regions.[Method] From 4 dimensions of feeding and importing,breeding,housing and polyculture situation,an evaluation index system was set up,and diary cattle brucellosis risk survey was conducted in 3 typical regions.Finally,systematic multilevel grey relation entropy method was applied to perform data analysis.[Result] The strong-to-weak sequence of Level 1 impact factor of diary cattle brucellosis was as follows:feeding and importinghousingpolyculture situationbreeding;the sequence of Level 2 impact factor was U32〉U12〉U11〉U31〉U21〉U42〉U43〉U23〉U22〉U41;the risk level sequence of 3 typical regions was Province A(County A1,A2,A3)Province B(County B1,B2,B3)Province C(County C1,C2,C3).[Conclusion] According to the weight of Level 1 index strata,administrative departments at all levels and dairy cattle farmers should lay emphasis on the aspects of feeding,importing and housing;viewed from the perspective of Level 2 index strata,dairy cattle farmers should value the siting of cattle field,the brucellosis surveillance before importing and milking modes most.According to the diary cattle brucellosis risk level of 3 typical regions,if administrative departments at all levels strengthen peoples' awareness of their personal health and increase investment in this area,with new healthy cultured atmosphere built,the risk level of diary cattle brucellosis will surly decline. 展开更多
关键词 Systematic multilevel grey relation entropy method Diary cattle brucellosis Risk assessment
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二元随机效应模型的相关性问题研究
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作者 杨文国 吴令云 +1 位作者 乔兆颖 张洁 《统计与决策》 CSSCI 北大核心 2020年第18期36-39,共4页
文章讨论二元随机效应模型的相关性问题。对于已给数据,拟合二元随机效应模型中两个随机效应相关系数的估计值ρ,能产生对第i次观测随机效应的估计值ui1、ui2,并计算样本相关系数r。结果显示,r和ρ有时差距较大,甚至ρ不显著,而r却是显... 文章讨论二元随机效应模型的相关性问题。对于已给数据,拟合二元随机效应模型中两个随机效应相关系数的估计值ρ,能产生对第i次观测随机效应的估计值ui1、ui2,并计算样本相关系数r。结果显示,r和ρ有时差距较大,甚至ρ不显著,而r却是显著的,出现"不一致"现象,特别是"独立随机效应模型"(ρ恒为0)的r可能显著。有时优化过程中ρ非常接近-1,从而使优化过程非正常终止,此时可以采用RE(τ)模型。 展开更多
关键词 多层数据(multilevel) 随机效应(random effects) MMLE RE(τ)模型
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Hierarchically designed MoWSe_(2)/WO_(3)/C anode for fast and efficient Na+storage
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作者 Jian Wang Yachuan Shao +6 位作者 Fei Yuan Huilan Sun Di Zhang Zhaojin Li S.Ramesh H.J.Woo Bo Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第5期291-301,I0008,共12页
Exploring anode materials with high energy and power density is one of the critical milestones in developing sodium-ion batteries/capacitors(SIBs/SICs).Here,the Mo and W-based bimetallic organic framework(Mo-W-MOF)wit... Exploring anode materials with high energy and power density is one of the critical milestones in developing sodium-ion batteries/capacitors(SIBs/SICs).Here,the Mo and W-based bimetallic organic framework(Mo-W-MOF)with core-shell structure is first formed by a facile strategy,followed by a selenization and carbonization strategy to finally prepare multileveled Mo WSe_(2)/WO_(3)/C anode materials with core-shell petal like curled nanosheet structure.Between the petal(MoSe_(2))-core(WO_(3))structure,the formation of WSe_(2)flakes by partial selenization on the surface of WO_(3)serves as a heterogeneous connection between MoSe_(2)and WO_(3).The enlarged layer distance(0.677 nm)between MoSe_(2)and WSe_(2)can facilitate the rapid transfer of Na+and electrons.The density functional theory(DFT)calculations verify that the Mo WSe_(2)/WO_(3)/C heterostructure performs excellent metallic properties.Ex-situ X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),and transmission electron microscopy(TEM)confirm the activation process from the initial insertion reaction to the later conversion reaction.Resultantly,when employed as the anode of SIBs,a remarkable capacity of 384.3 mA h g-1after 950 cycles at 10 A g^(-1)is performed.Furthermore,the SICs assembled with commercial activated carbon(AC)as the cathode exhibits a remarkable energy density of 81.86 W h kg^(-1)(at 190 W kg^(-1))and 72.83 W h kg^(-1)(at 3800 W kg^(-1)).The unique structural design and the reaction investigation of the electrode process can provide a reference for the development of transition metal chalcogenides anodes. 展开更多
关键词 multileveled MoWSe2/WO_(3)/C Structure change HETEROSTRUCTURE Metallic properties Enlarged lattice distance The activation process
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