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A New Equalization Method for Lithium-Ion Battery Packs Based on CUK
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作者 Yu Zhang Sheng Tian Yongkang Zhang 《Energy Engineering》 EI 2024年第6期1459-1472,共14页
Aiming at the traditional CUK equalizer can only perform energy equalization between adjacent batteries,if the two single batteries that need to be equalized are far away from each other,there will be the problem of l... Aiming at the traditional CUK equalizer can only perform energy equalization between adjacent batteries,if the two single batteries that need to be equalized are far away from each other,there will be the problem of longer energy transmission path and lower equalization efficiency,this paper optimizes the CUK equalizer and optimizes its peripheral selection circuit,which can support the equalization of single batteries at any two positions.The control strategy adopts the open-circuit voltage(OVC)of the battery and the state of charge(SOC)of the battery as the equalization variables,and selects the corresponding equalization variables according to the energy conditions of the two batteries that need to be equalized,and generates the adaptive equalization current with an adaptive PID controller in order to improve the equalization efficiency.Simulation modeling is performed in Matlab/Simulink 2021b,and the experimental results show that the optimized CUK equalizer in this paper improves the equalization time by 25.58%compared with the traditional CUK equalizer.In addition,compared with the mean value difference(MVD)method,the adaptive PID method reduces the equalization time by about 30%in the static and charging and discharging experimental environments,which verifies the superiority of this equalization scheme. 展开更多
关键词 battery balancing CUK equalizer adaptive PID SOC
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Equalization Reconstruction Algorithm Based on Reference Signal Frequency Domain Block Joint for DTMB-Based Passive Radar
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作者 Shuai Ma Zeqi Yang +2 位作者 Hua Zhang Yiheng Liu Xiaode Lyu 《Journal of Beijing Institute of Technology》 EI CAS 2024年第1期41-53,共13页
Channel equalization plays a pivotal role within the reconstruction phase of passive radar reference signals.In the context of reconstructing digital terrestrial multimedia broadcasting(DTMB)signals for low-slow-small... Channel equalization plays a pivotal role within the reconstruction phase of passive radar reference signals.In the context of reconstructing digital terrestrial multimedia broadcasting(DTMB)signals for low-slow-small(LSS)target detection,a novel frequency domain block joint equalization algorithm is presented in this article.From the DTMB signal frame structure and channel multipath transmission characteristics,this article adopts a unconventional approach where the delay and frame structure of each DTMB signal frame are reconfigured to create a circular convolution block,facilitating concurrent fast Fourier transform(FFT)calculations.Following equalization,an inverse fast Fourier transform(IFFT)-based joint output and subsequent data reordering are executed to finalize the equalization process for the DTMB signal.Simulation and measured data confirm that this algorithm outperforms conventional techniques by reducing signal errors rate and enhancing real-time processing.In passive radar LSS detection,it effectively suppresses multipath and noise through frequency domain equalization,reducing false alarms and improving the capabilities of weak target detection. 展开更多
关键词 passive radar frequency domain equalization reference signal reconstruction digital terrestrial multimedia broadcasting(DTMB)
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Automatic SOC Equalization Strategy of Energy Storage Units with DC Microgrid Bus Voltage Support
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作者 Jingjing Tian Shenglin Mo +1 位作者 Feng Zhao Xiaoqiang Chen 《Energy Engineering》 EI 2024年第2期439-459,共21页
In this paper,an improved sag control strategy based on automatic SOC equalization is proposed to solve the problems of slow SOC equalization and excessive bus voltage fluctuation amplitude and offset caused by load a... In this paper,an improved sag control strategy based on automatic SOC equalization is proposed to solve the problems of slow SOC equalization and excessive bus voltage fluctuation amplitude and offset caused by load and PV power variations in a stand-alone DC microgrid.The strategy includes primary and secondary control.Among them,the primary control suppresses the DC microgrid voltage fluctuation through the I and II section control,and the secondary control aims to correct the P-U curve of the energy storage system and the PV system,thus reducing the steady-state bus voltage excursion.The simulation results demonstrate that the proposed control strategy effectively achieves SOC balancing and enhances the immunity of bus voltage.The proposed strategy improves the voltage fluctuation suppression ability by approximately 39.4%and 43.1%under the PV power and load power fluctuation conditions,respectively.Furthermore,the steady-state deviation of the bus voltage,△U_(dc) is only 0.01–0.1 V,ensuring stable operation of the DC microgrid in fluctuating power environments. 展开更多
关键词 Automatic equalization independent DC microgrid improve droop control secondary control state of charge
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GENDER EQUALITY IN THE CHINESE WORKPLACE
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作者 Huang Jiangqin 《China Report ASEAN》 2024年第2期50-53,共4页
Gender equality is a significant issue in the economic and social sectors.A McKinsey study found that promoting gender equality in the workplace could contribute US$13 trillion to global GDP growth.And if China reache... Gender equality is a significant issue in the economic and social sectors.A McKinsey study found that promoting gender equality in the workplace could contribute US$13 trillion to global GDP growth.And if China reaches the forefront of gender equality in the workplace in the Asia-Pacific region,it would generate about US$3 trillion in GDP. 展开更多
关键词 equalITY s. GLOBAL
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On the Equality of Weighted BajratarevićMeans to Quasi-Arithmetic Means
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作者 Yaxun Yang 《Journal of Applied Mathematics and Physics》 2024年第4期1126-1133,共8页
In this paper, we considered the equality problem of weighted Bajraktarević means with weighted quasi-arithmetic means. Using the method of substituting for functions, we first transform the equality problem into solv... In this paper, we considered the equality problem of weighted Bajraktarević means with weighted quasi-arithmetic means. Using the method of substituting for functions, we first transform the equality problem into solving an equivalent functional equation. We obtain the necessary and sufficient conditions for the equality equation. 展开更多
关键词 Bajraktarević Means Quasi-Arithmetic Means equality Problem Functional Equation
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Simple shear extrusion versus equal channel angular pressing:A comparative study on the microstructure and mechanical properties of an Mg alloy 被引量:1
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作者 A.Rezaei R.Mahmudi +1 位作者 C.Cayron R.E.Logé 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第5期1769-1790,共22页
Two severe plastic deformation(SPD)techniques of simple shear extrusion(SSE)and equal channel angular pressing(ECAP)were employed to process an extruded Mg-6Gd-3Y-1.5Ag(wt%)alloy at 553 K for 1,2,4 and 6 passes.The mi... Two severe plastic deformation(SPD)techniques of simple shear extrusion(SSE)and equal channel angular pressing(ECAP)were employed to process an extruded Mg-6Gd-3Y-1.5Ag(wt%)alloy at 553 K for 1,2,4 and 6 passes.The microstructural evolutions were studied by electron back scattered diffraction(EBSD)analysis and transmission electron microscopy(TEM).The initial grain size of 7.5μm in the extruded alloy was reduced to about 1.3μm after 6 SPD passes.Discontinuous dynamic recrystallization was suggested to be operative in both SSE and ECAP,with also a potential contribution of continuous dynamic recrystallization at the early stages of deformation.The difference in the shear strain paths of the two SPD techniques caused different progression rate of dynamic recrystallization(DRX),so that the alloys processed by ECAP exhibited higher fractions of recrystallization and high angle grain boundaries(HAGBs).It was revealed that crystallographic texture was also significantly influenced by the difference in the strain paths of the two SPD methods,where dissimilar basal plane texture components were obtained.The compression tests,performed along extrusion direction(ED),indicated that the compressive yield stress(CYS)and ultimate compressive strength(UCS)of the alloys after both SEE and ECAP augmented continuously by increasing the number of passes.ECAP-processed alloys had lower values of CYS and UCS compared to their counterparts processed by SSE.This difference in the mechanical responses was attributed to the different configurations of basal planes with respect to the loading direction(ED)of each SPD technique. 展开更多
关键词 Mg-Gd-Y alloys Severe plastic deformation Simple shear extrusion equal channel angular pressing Dynamic recrystallization Mechanical properties
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Heterogeneous Fault-Tolerant Aggregate Signcryption with Equality Test for Vehicular Sensor Networks
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作者 Yang Zhao Jingmin An +1 位作者 Hao Li Saru Kumari 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第10期555-575,共21页
The vehicular sensor network (VSN) is an important part of intelligent transportation, which is used for real-timedetection and operation control of vehicles and real-time transmission of data and information. In the ... The vehicular sensor network (VSN) is an important part of intelligent transportation, which is used for real-timedetection and operation control of vehicles and real-time transmission of data and information. In the environmentofVSN, massive private data generated by vehicles are transmitted in open channels and used by other vehicle users,so it is crucial to maintain high transmission efficiency and high confidentiality of data. To deal with this problem, inthis paper, we propose a heterogeneous fault-tolerant aggregate signcryption scheme with an equality test (HFTASET).The scheme combines fault-tolerant and aggregate signcryption,whichnot onlymakes up for the deficiency oflow security of aggregate signature, but alsomakes up for the deficiency that aggregate signcryption cannot tolerateinvalid signature. The scheme supports one verification pass when all signcryptions are valid, and it supportsunbounded aggregation when the total number of signcryptions grows dynamically. In addition, this schemesupports heterogeneous equality test, and realizes the access control of private data in different cryptographicenvironments, so as to achieve flexibility in the application of our scheme and realize the function of quick searchof plaintext or ciphertext. Then, the security of HFTAS-ET is demonstrated by strict theoretical analysis. Finally, weconduct strict and standardized experimental operation and performance evaluation, which shows that the schemehas better performance. 展开更多
关键词 Aggregate signcryption FAULT-TOLERANT HETEROGENEOUS equality test vehicular sensor network
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A Cooperative Cognitive Radio Spectrum Sensing Based on Correlation Sum Method with Linear Equalization
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作者 Entesar Gemeay Ahmed Lebda 《Communications and Network》 2023年第1期1-14,共14页
For moving forward toward the next generations of information technology and wireless communication, it is becoming necessary to find new resources of spectrum to fulfill the requirements of next generations from high... For moving forward toward the next generations of information technology and wireless communication, it is becoming necessary to find new resources of spectrum to fulfill the requirements of next generations from higher data rates and more capacity. Increasing efficiency of the spectrum usage is an urgent need as an intrinsic result of the rapidly increasing number of wireless users and the conversion of voice-oriented applications to multimedia applications. Spectrum sensing techniques in cognitive radio technology work upon an optimal usage of the available spectrum determined by the Federal Communication Commission (FCC). In this paper, the performance of a cooperative cognitive radio spectrum sensing detection based on the correlation sum method by utilizing the multiuser multiple input multiple output (MU_MIMO) technique over fading and Additive White Gaussian Noise (AWGN) channel is analyzed. Equalization is used at the receiver to compensate the effect of fading channels and improve the reliability of spectrum sensing. The performance is compared with the performance of Energy detection technique. The simulation results show that the detection performance of cooperative correlation sum method is more efficient than that obtained for the cooperative Energy detection technique. 展开更多
关键词 Spectrum Sensing Cognitive Radio MIMO equalIZATION
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Superplastic behavior of a fine-grained Mg-Gd-Y-Ag alloy processed by equal channel angular pressing
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作者 A.Rezaei R.Mahmudi R.E.Logé 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第10期3815-3828,共14页
An extruded Mg-6Gd-3Y-1.5Ag(wt%) alloy was processed by 6 passes of equal channel angular pressing(ECAP) at 553 K using route Bc to refine the microstructure. Electron back-scattered diffraction(EBSD) analysis showed ... An extruded Mg-6Gd-3Y-1.5Ag(wt%) alloy was processed by 6 passes of equal channel angular pressing(ECAP) at 553 K using route Bc to refine the microstructure. Electron back-scattered diffraction(EBSD) analysis showed a fully recrystallized microstructure for the extruded alloy with a mean grain size of 8.6 μm. The microstructure of the ECAP-processed alloy was uniformly refined through dynamic recrystallization(DRX). This microstructure contained fine grains with an average size of 1.3 μm, a high fraction of high angle grain boundaries(HAGBs), and nano-sized Mg_(5)Gd-type particles at the boundaries of the DRXed grains, detected by transmission electron microscopy(TEM). High-temperature shear punch testing(SPT) was used to evaluate the superplastic behavior of both the extruded and ECAP-processed alloys by measuring the strain rate sensitivity(SRS) index(m-value). While the highest m-value for the extruded alloy was measured to be 0.24 at 673 K, the ECAP-processed alloy exhibited much higher m-values of 0.41 and 0.52 at 598 and 623 K, respectively,delineating the occurrence of superplastic flow. Based on the calculated average activation energy of 118 kJ mol^(-1) and m-values close to 0.5, the deformation mechanism for superplastic flow at the temperatures of 598 and 623 K for the ECAP-processed alloys was recognized to be grain boundary sliding(GBS) assisted by grain boundary diffusion. 展开更多
关键词 Mg-Gd-Y alloys equal channel angular pressing SUPERPLASTICITY Strain rate sensitivity Grain boundary sliding
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Low-complexity iterative equalization for OTFS based on alternating minimization
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作者 HE Xin JIA Haoxiang +2 位作者 SUN Yutong ZHOU Zijian ZHAO Danfeng 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第4期851-860,共10页
To achieve robust communication in high mobility scenarios,an iterative equalization algorithm based on alternating minimization(AM)is proposed for the orthogonal time frequency space(OTFS)system.The algorithm approxi... To achieve robust communication in high mobility scenarios,an iterative equalization algorithm based on alternating minimization(AM)is proposed for the orthogonal time frequency space(OTFS)system.The algorithm approximates the equalization problem to a convex function optimization problem in the real-valued domain and solves the problem iteratively using the AM algorithm.In the iterative process,the complexity of the proposed algorithm is reduced further based on the study of the cyclic structure and sparse property of the OTFS channel matrix in the delay-Doppler(DD)domain.The new method for OTFS is simulated and verified in a high-speed mobile scenario and the results show that the proposed equalization algorithm has excellent bit error rate performance with low complexity. 展开更多
关键词 orthogonal time frequency space(OTFS) alternating minimization(AM) high-speed mobile scenario iterative equalization
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A Coherent Interpretation of Economic Compensation for Divorce:Taking Gender Equality as the Basis
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作者 高礼杰 CHEN Feng(译) 《The Journal of Human Rights》 2023年第5期1097-1114,共18页
Article 1088 of China's Civil Code grants the right to seek economic compensation in divorce cases.However,significant confusion persists regarding the values,interpretations of doctrine,and legal techniques relat... Article 1088 of China's Civil Code grants the right to seek economic compensation in divorce cases.However,significant confusion persists regarding the values,interpretations of doctrine,and legal techniques related to this compensation.Various viewpoints have emerged on the nature of compensation,including notions of household wages,human capital investment,moral obligation,and damages recovery.Concerning compensation standards,there are proposals such as the“humanitarian assistance”theory,“household wages”theory,“expected interest”theory,or“loss of interest”theory.By examining the evolution,legal principles,and practical applications of economic compensation for divorce from a human rights perspective,we aim to establish the legal foundation for this compensation,grounded in principles of gender equality.It clarifies that the compensation essentially confirms and restores individual development opportunities and the right to development in the context of gender inequality.This approach aims to provide a more coherent interpretation of clauses of economic compensation for divorce in terms of legal purposes,legal doctrines,and legal techniques,thus offering a more reasonable perspective to reconcile theoretical and practical discrepancies in economic compensation for divorce. 展开更多
关键词 Civil Code economic compensation human rights gender equality
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The Protection of the Right to Equality of the Elderly in the Digital Society
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作者 胡敏洁 汪敬涛 ZHANG Lianying(译) 《The Journal of Human Rights》 2023年第5期994-1015,共22页
The inequality faced by the elderly in a digital society is the digital inequality caused by both public and private actions,as well as the societal inequality exacerbated by the digital inequality.The essence of this... The inequality faced by the elderly in a digital society is the digital inequality caused by both public and private actions,as well as the societal inequality exacerbated by the digital inequality.The essence of this issue lies in the unequal social participation due to the expansion of digital space under digital inequality.The characteristics of the elderly,combined with their inherent human dignity,determine that the ultimate goal of protecting their right to equality in a digital society is not limited to equal digital rights alone.Instead,it aims to ensure that the elderly have equal opportunities for social participation in both digital and non-digital spaces by eliminating digital inequality and curbing the expansion of digital space.This ensures the autonomy of the elderly in the digital society.Accordingly,the State should implement two policies based on both prohibitive obligations that prevent direct infringements and protective obligations that safeguard the equal rights of the elderly against encroachments from private entities.The first policy,“Digital Integration”,empowers the elderly with digital skills and helps them actively integrate into the digital society.The second policy,“Digital Coexistence,”ensures that the elderly can equally participate in society even when they choose to abstain from digital technology. 展开更多
关键词 digital society right to equality digital coexistence digital integration
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Dilemma and Solution for Relief in the Right to Equal Employment-From the Perspective of Rectifying Private Law with Social Law
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作者 周圆 CHEN Feng 《The Journal of Human Rights》 2023年第2期395-421,共27页
At present,the legal remedies in terms of the right to equal employment in China are mainly related to private law,that is,laborers seek direct legal remedies for personality rights liability and infringement liabilit... At present,the legal remedies in terms of the right to equal employment in China are mainly related to private law,that is,laborers seek direct legal remedies for personality rights liability and infringement liability according to typical private law,supplemented by indirect remedies for labor contract liability under special private law.However,there are many challenges in private law remedies for the right to equal employment,which are manifested in the misunderstanding of the general tort identification of employment discrimination,the loopholes in the regulations on discriminatory employment,the imbalance in the burden of proof,and the limitation and alienation of the functions of civil liability and private law autonomy.The root of those problems lies in the fact that the nature of anti-employment discrimination law is not private law but social law.Equal employment involves both public and private interests,and it should be based on the public interest of society and adhere to the value orientation of prioritizing fairness while taking into account efficiency.Improving the legal relief mechanism for protecting the right to equal employment,with a focus on correcting private law with social law,is the solution to the dilemma.Specific measures include establishing the special tort liability system for equal employment,the legal mechanism against discriminatory labor contracts,the public-private integrated legal responsibility system,and an essentially fair system for the responsibility of adducing evidence. 展开更多
关键词 right to equal employment private law social law right infringement of discrimination in employment discriminatory employment behaviors
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The Rise of China’s Women’s Basketball Team:An Exploration of Gender Equality in Professional Basketball
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作者 Naiyuan Fan 《Journal of Contemporary Educational Research》 2023年第11期11-16,共6页
This article explores the rise of the Chinese women’s basketball team in professional basketball and its relationship to gender equality issues.In view of the gender differences in salary,market value,social status,a... This article explores the rise of the Chinese women’s basketball team in professional basketball and its relationship to gender equality issues.In view of the gender differences in salary,market value,social status,and other aspects,the article proposes a series of strategies to promote the realization of gender equality for female basketball players in professional basketball.This article points out that the rise of the Chinese women’s basketball team will lead the process of gender equality and lay the foundation for a more equitable and inclusive future.To achieve this goal,this article highlights the importance of improving the competitive level of female athletes,improving basic education,promoting basketball culture,and promoting gender equality. 展开更多
关键词 Chinese women’s basketball Professional basketball Gender equality SALARY Market value Social status Competitive level Female athletes
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基于双层极值法的储能系统锂离子电池均衡实验设计
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作者 颜宁 张骞 +1 位作者 朱冬梅 任自艳 《实验技术与管理》 CAS 北大核心 2024年第3期108-115,共8页
储能系统初始参数和运行环境的差异性,会导致电池单体荷电状态(state of charge,SOC)的不一致性,降低储能系统能量利用率。为解决上述问题,设计了基于双层极值法的锂离子电池均衡实验。采用耦合电感与Flyback变换器搭建均衡系统双层架构... 储能系统初始参数和运行环境的差异性,会导致电池单体荷电状态(state of charge,SOC)的不一致性,降低储能系统能量利用率。为解决上述问题,设计了基于双层极值法的锂离子电池均衡实验。采用耦合电感与Flyback变换器搭建均衡系统双层架构,建立电池组端电压、均衡电流及占空比间的关联特性;以储能电池端电压作为均衡目标,提出基于双层极值法的锂离子电池快速均衡方法;搭建电池均衡实验教学平台,设计充放电及静置均衡实验,通过仿真分析和实验数据验证所提方法的有效性。该教学实验将理论知识、实验操作及数据分析相结合,有助于提升电气工程专业相关课程实验的质量和效果。 展开更多
关键词 锂离子电池 双层极值法 均衡实验 充放电均衡 静置均衡
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共同富裕的具体目标和制度选择——基于分配公正原则的研究 被引量:1
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作者 李石 《山东大学学报(哲学社会科学版)》 北大核心 2024年第1期84-92,共9页
党的二十大报告指出,中国式现代化是全体人民共同富裕的现代化。学术界、政策界应该对什么是共同富裕、共同富裕的制度基础和具体目标是什么,展开充分讨论并达成共识。促进共同富裕的关键在于提升低收入人群的生活前景。为此,应当采用... 党的二十大报告指出,中国式现代化是全体人民共同富裕的现代化。学术界、政策界应该对什么是共同富裕、共同富裕的制度基础和具体目标是什么,展开充分讨论并达成共识。促进共同富裕的关键在于提升低收入人群的生活前景。为此,应当采用当代分配公正研究中提出的三种原则——按需分配、机会平等、差别原则——对公共资源进行分配。具体的分配方案:一是基本需要按需分配,二是稀缺资源保证机会平等,三是保证低收入人群的福利水平持续提升。在此制度设计的基础上,可以提出促进共同富裕的三个具体目标或规范性指标:第一,覆盖全民的、均质的社会保障体系;第二,跨区域的、优质的公立教育;第三,贫富差距被控制在一定范围内。 展开更多
关键词 分配公正 共同富裕 按需分配 机会平等 贫富差距
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一种宽带非线性信道校正方法
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作者 刘景元 王威 《现代电子技术》 北大核心 2024年第7期33-36,共4页
针对高速数传解调器接收宽带高阶调制信号时因信道非线性导致的性能恶化问题,提出一种基于两层自适应均衡网络的非线性信道校正方法。该方法先利用递归最小二乘法获得Volterra非线性前置校正系数,再利用自适应基带均衡器消除信道的剩余... 针对高速数传解调器接收宽带高阶调制信号时因信道非线性导致的性能恶化问题,提出一种基于两层自适应均衡网络的非线性信道校正方法。该方法先利用递归最小二乘法获得Volterra非线性前置校正系数,再利用自适应基带均衡器消除信道的剩余影响,以提升解调器的捕获跟踪能力,并在高速数传解调器工程应用中实现2.4 Gb/s 16QAM信号的稳定接收。 展开更多
关键词 高速数传 信道校正 自适应均衡网络 Volterra非线性均衡 递归最小二乘法 自适应基带均衡器
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基础教育空间资本化效应与空间优化策略
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作者 林雄斌 牛步青 +3 位作者 窦茜茜 钟晶晶 林伊婷 杨家文 《中国软科学》 CSCD 北大核心 2024年第3期89-97,共9页
受限于优质教育资源的有限性及其分配机制,基础教育的数量、质量与获取机制会显著影响土地和住房价格,形成具有时空间异质性的资本化效应,从而影响教育均等化与可及性。如何理解这种资本化效应的理论基础、测度方法与影响机制,采取有效... 受限于优质教育资源的有限性及其分配机制,基础教育的数量、质量与获取机制会显著影响土地和住房价格,形成具有时空间异质性的资本化效应,从而影响教育均等化与可及性。如何理解这种资本化效应的理论基础、测度方法与影响机制,采取有效策略降低教育资本化效应,推动基础教育均等化与可及性,成为新型城镇化亟需解决的重要问题。基于此,系统研究基础教育资本化效应的理论基础、研究过程、实证方法与结果,以及差异化结果的影响因素,并从学区分配制度渐进改革、溢价捕获工具使用、保障住房多层优化配置等提出促进教育起点公平的政策建议。这对推动基础教育资源优化分配,实现基础教育资源获取的均等化与可及性,具有一定的理论和实践价值。 展开更多
关键词 基础教育 教育公平 住房资本化 均等化与可及性
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基于记忆多项式的Volterra混合均衡器设计与研究
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作者 贾科军 雷蕾 +1 位作者 蔺莹 余彩虹 《光通信研究》 北大核心 2024年第3期36-44,共9页
【目的】发光二极管(LED)的非线性特性导致可见光通信(VLC)系统的误码率(BER)性能恶化,特别是在具有较高峰均功率比(PAPR)的光正交频分复用(O⁃OFDM)系统中。基于Volterra级数的单级均衡器可以处理LED非线性高阶失真,且延时较小。但是求... 【目的】发光二极管(LED)的非线性特性导致可见光通信(VLC)系统的误码率(BER)性能恶化,特别是在具有较高峰均功率比(PAPR)的光正交频分复用(O⁃OFDM)系统中。基于Volterra级数的单级均衡器可以处理LED非线性高阶失真,且延时较小。但是求解传统Volterra级数需要多重积分运算,基于Volterra级数的均衡器实现复杂度高,且单级均衡器存在误差累积,因此均衡抑制效果有限。【方法】首先,针对传统Volterra级数计算复杂度高的问题,只保留Volterra级数中各阶非线性项和内核系数的高阶幂级数项,提出了基于记忆多项式的Volterra级数(MPVS)。相比于传统Volterra级数降低了计算复杂度,同时考虑了当前时刻的所有输入信号,提高了非线性系统建模的精度。然后,设计基于记忆多项式的Volterra(MPV)均衡器和基于记忆多项式的Volterra判决反馈均衡器(MPV⁃DFE),对于单级MPV⁃DFE,若判决部分一个码元判断错误,那么这种错误会连续成串出现,导致整个码元序列受到影响。文章提出将MPV和MPV⁃DFE两个非线性均衡器级联构成混合后均衡器(MPV+MPV⁃DFE)。MPV均衡器对LED非线性失真信号一级均衡,可以抑制一部分非线性失真,从而减少MPV⁃DFE码元判断错误。再经过MPV⁃DFE二次均衡,可以更好地抑制残留的非线性失真。【结果】最后,采用蒙特卡洛BER仿真方法验证系统设计的有效性。结果表明:与单级MPV均衡器、线性级联非线性混合均衡器(LMS+MPV-DFE)相比,在4阶正交幅度调制(QAM)非对称限幅光OFDM(ACO⁃OFDM)系统BER为10^(-4)时,所提混合均衡器分别可以获得大约7和2 dB的信噪比增益。【结论】MPV均衡器实现简单,且将两级非线性均衡器级联设计混合均衡器可以更好地抑制LED非线性失真。 展开更多
关键词 可见光通信 发光二极管非线性 沃尔泰拉级数 混合后均衡器
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车用锂离子电池快速均衡方法研究
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作者 张宇 王军 常春 《车用发动机》 北大核心 2024年第3期74-79,共6页
为解决电动车电池在工作时出现的能量不一致的问题,设计了一种基于三绕组变压器的双层均衡拓扑结构,该拓扑可实现任意单体与单体、单体与部分单体、部分单体与单体、单体与整体之间的能量传输,并通过比较电池之间的荷电状态(SOC)、工作... 为解决电动车电池在工作时出现的能量不一致的问题,设计了一种基于三绕组变压器的双层均衡拓扑结构,该拓扑可实现任意单体与单体、单体与部分单体、部分单体与单体、单体与整体之间的能量传输,并通过比较电池之间的荷电状态(SOC)、工作时的产热情况,确定分状态的均衡控制策略。使用MATLAB/Simulink软件进行模型搭建并仿真,试验表明:该均衡方法能够有效缩短均衡时长,缓解电池间的不一致性问题,对比传统变压器均衡方法,静置、充电、放电所需均衡时间分别缩短67.7%,66.12%,30.05%。 展开更多
关键词 锂离子电池 电池均衡 拓扑结构
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