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考虑车网互动的园区电网动态双层能量管理策略

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上海交通大学学报 2024年第6期58卷 916-925页

作者：邱革非冯泽华沈赋何超何虹辉刘铠铭昆明理工大学电力工程学院昆明650500

为解决大量接入的清洁能源出力波动和充电场内汽车数量的随机变化给电网能量管理带来的困难,提出一种园区电网双层优化控制策略.上层基于模型预测控制技术建立风光储集成动态优化模型,综合应用园区电池储能系统和电动汽车(EV)电池储能... 详细信息

为解决大量接入的清洁能源出力波动和充电场内汽车数量的随机变化给电网能量管理带来的困难,提出一种园区电网双层优化控制策略.上层基于模型预测控制技术建立风光储集成动态优化模型,综合应用园区电池储能系统和电动汽车(EV)电池储能系统参与电网能量平衡.下层则考虑同时满足EV车主对EV的充电需求和上层能量调度的车网互动管理需求,制定园区电网内停车场的EV有序充放电策略.仿真算例验证表明:所提策略能将分散园区各处的EV储能集成为统一虚拟储能,扩展园区电网储能系统,增加可再生分布式电源的消纳与园区电网的经济效益.

关键词：园区电网电动汽车入网电动汽车虚拟储能模型预测控制混合储能系统

A New Nonlinear Companding Algorithm Based on Tangent Linearization Processing for PAPR Reduction in OFDM Systems

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China Communications 2020年第8期17卷 133-146页

作者： kaiming liu Li Wang Yuan'an liu School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China Beijing Key Laboratory of Work Safety Intelligent Monitoring Beijing University of Posts and TelecommunicationsBeijing 100876China

In this paper, a novel nonlinear companding transform(NCT) is proposed to reduce the Peak-to-Average Power Ratio(PAPR) of orthogonal frequency division multiplexing(OFDM) signals. The companding function is designed based on continuously differentiable reshaping of the probability density function(PDF) of signal amplitudes. The original PDF is cut off for PAPR reduction, and lower and medium segments of original PDF are scaled and linearized respectively, for maintaining power and cumulative distribution constraints. The linearized segment is set to be the tangent of the scaled version at the inflexion point, so as to reduce the out-ofband(OOB) radiation as much as possible. Parameters of the proposed scheme are solved under joint constraints of constant power and unity cumulative distribution. A new receiving method is also proposed to improve the bit error rate(BER) performance of OFDM systems. Simulation results indicate the proposed scheme can achieve better OOB radiation and BER performance at same PAPR levels, compared with existing similar companding algorithms.

关键词： OFDM PAPR nonlinear companding transform tangent linearization

Closed-Form and Analytical BER Expression for OFDM System with μ-Law Companding Operation

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China Communications 2019年第7期16卷 61-69页

作者： Zhitong Xing kaiming liu Yuan’an liu Institute of Smart Wireless Information Technology Beijing University of Posts and Telecommunications

The μ-law companding function has been applied widely in orthogonal frequency division multiplexing (OFDM) to reduce the peak-to-average power ratio (PAPR). However, nonlinear distortion caused by the μ-law companding function is considered a key impairment in OFDM communication systems. Few studies have addressed theoretical nonlinear distortion caused by μ-law companding function for OFDM systems. In this paper, we derive a closed-form expression of signal distortion as well as the closed-form bit error rate (BER) of OFDM system caused by the μ-law companding function. Based on the theoretical signal distortion and BER expression, the theoretical BER value and signal distortion value can also be calculated, which can guide us to choose appropriate μ value for different BER condition and bit-to-noise (Eb/N0) condition efficiently. Then the PAPR performance can also be predicted. The results show good agreement on the Monte-Carlo simulation results and the obtained theoretical BER results. Furthermore, based on theoretical signal distortion and theoretical BER expression, the figure of the relationship among BER value, Eb/N0 and μ is also given. Based on this figure, we can find the appropriate μ law for different BER and Eb/N0 condition. And then the PAPR performance can also be predicted.

关键词： OFDM PAPR nonlinear companding function μ law companding scheme

PAPR reduction for FBMC-OQAM systems using P-PTS scheme

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The Journal of China Universities of Posts and Telecommunications 2015年第6期22卷 78-85页

作者： liu kaiming Hou Jundan Zhang Peng liu Yuan'an School of Telecommunication Engineering Beijing University of Posts and Telecommunications

Filter bank multi-carrier （FBMC） with offset quadrature amplitude modulation （OQAM） has been regarded as one of the candidates for next generation broadband wireless communication systems. Being a multi-carrier technique, FBMC suffers from the inherent drawback of high peak-to-average power ratio （PAPR）. And it has been turned out that conventional PAPR reduction schemes for orthogonal frequency division multiplexing （OFDM） systems are ineffective for FBMC-OQAM systems, due to the overlapping structure of FBMC-OQAM signals. In this paper, we propose an efficient PAPR reduction scheme based on a two-step optimization structure, named pretreated partial transmit sequence （P-PTS）. The first step uses a multiple overlapping symbols joint optimization scheme that the phase rotation sequences for current symbol is determined and optimized according to previous overlapped symbols. And in the second step, it employs a novel segment PAPR reduction scheme based on PTS technique. Simulation results indicate that the proposed P-PTS scheme can achieve better PAPR reduction performance than conventional methods with lower computational complexity and the complexity can be traded off more flexibly with PAPR reduction performance.

关键词： FBMC-OQAM PAPR P-PTS

Novel PAPR Reduction Scheme Based on Continuous Nonlinear Piecewise Companding Transform for OFDM Systems

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China Communications 2020年第9期17卷 177-192页

作者： Zhitong Xing kaiming liu Kaiyuan Huang Bihua Tang Yuanan liu Beijing Key Laboratory of Work Safety Intelligent Monitoring(Beijing University of Posts and Telecommunications) School of Electronic EngineeringBeijing University of Posts and TelecommunicationsBeijing 10086China

In this paper,a novel efficient continuous piecewise nonlinear companding scheme is proposed for reducing the peak-to-average power ratio(PAPR)of orthogonal frequency division multiplexing(OFDM)*** the proposed companding transform,signal samples with large amplitudes is clipped for peak power reduction,and the signal samples with medium amplitudes is nonlinear transformed with power *** the signal samples with small amplitudes remain *** whole companding function is continuous and smooth in the range of positive numbers,which is beneficial for guaranteeing the bit error rate(BER)and power spectral density(PSD)*** scheme can achieve a significant reduction in *** at the same time,it cause little increment in BER and PSD *** results indicate the superiority of the proposed scheme over existing companding schemes.

关键词： Orthogonal frequency-division multiplexing(OFDM) peak-to-average power ratio(PAPR) companding scheme companding distortion

Ergodic interference alignment for MIMO interference system with variable channel

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The Journal of China Universities of Posts and Telecommunications 2015年第1期22卷 11-16页

作者： Ren Haiying liu Yuan'an liu Fang Gao Jinchun liu kaiming Xie Gang School of Electronic Engineering Beijing University of Posts and Telecommunications

The authors pay focus on the K user multiple-input multiple-output（MIMO） Gaussian interference channel（IC） with M transmitting antennas and N receiving antennas, in which min（M, N）/max（M, N）≧（K-1）/[K（K-2）] and K 〉3. The channel coefficients are variable, time varying or frequency selectively drawn from a continuous distribution. Based on ergodic interference alignment（IA）, an achievable scheme was proposed to achieve a total of KMN/（M ＋N） degrees of freedom（DoF）. The ergodic IA scheme can reach the optimal Do F value with simply linear beamforming and finite symbols. Furthermore, the achievable rate of the ergodic IA scheme was derived at any signal-to-noise ratio（SNR）. With numerical simulation, the performance of the proposed scheme is evaluated.

关键词： degrees of freedom ergodic interference alignment interference channel multiple-input multiple-output

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热休克蛋白70抑制剂的研究进展

中国药物化学杂志 2024年第4期34卷 329-338页

作者：张晓焜刘磊刘凯明李灵君袁静药物成药性评价与系统转化全国重点实验室天津300301 朴创医药科技(天津)有限公司天津300301 天津市新药设计与发现重点实验室天津300301

热休克蛋白70(HSP70)广泛分布于细胞中,在应激状态下促进蛋白质的折叠和成熟。近年来,研究发现HSP70在多种恶性肿瘤细胞中高表达,并具有抑制细胞凋亡和干扰肿瘤免疫等功能,其可能成为肿瘤治疗的潜在靶点。本文作者对HSP70结构、作用机... 详细信息

热休克蛋白70(HSP70)广泛分布于细胞中,在应激状态下促进蛋白质的折叠和成熟。近年来,研究发现HSP70在多种恶性肿瘤细胞中高表达,并具有抑制细胞凋亡和干扰肿瘤免疫等功能,其可能成为肿瘤治疗的潜在靶点。本文作者对HSP70结构、作用机制以及当前抗肿瘤的HSP70小分子抑制剂研究进展进行综述,并讨论目前研究面临的问题与挑战,以期为后续HSP70抑制剂的开发提供参考。

关键词：热休克蛋白70 小分子抑制剂抗肿瘤药物共晶结构

Management and instant query of distributed oil and gas production dynamic data

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Petroleum Exploration and Development 2019年第5期46卷 1014-1021页

作者： WANG Hongliang MU Longxin SHI Fugeng liu kaiming QIAN Yurong PetroChina Research Institute of Petroleum Exploration&Development Beijing 100083China Xinjiang University Urumqi 830008China

The multidimensional analysis engine data management platform is constructed using big data distributed storage and parallel computing,data warehouse modeling technology,realizing the optimal management and instant query of distributed oil and gas production dynamic big *** centralized management and quick response of the production data of more than 36×10^4 oil,gas and water wells is *** analysis subject model of oil,gas and water well production is built to pretreat the relevant *** the level of China National Petroleum Corporation(CNPC),the rapid analysis and applications such as oil and gas production tracking,early production warning of key oilfields,analysis of low production wells and long shutdown wells,classification of reservoir development laws have been realized,and the processing time has been shortened from 1 d to 5 *** basic unit of oil and gas production analysis is refined from oilfield to single well,making the production management more *** process can be traced step by step according to CNPC,oil field company,field,block and single well,and the oil and gas production performance of each unit can be mastered in real time.

关键词： production performance big data parallel computation multidimensional analysis optimal management instant query early production warning

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双路电源的主动均流电路系统研究

电子器件 2024年第1期47卷 74-78页

作者：付宗见李福胜刘开茗梁明亮郑州铁路职业技术学院人工智能学院河南郑州451460

广泛使用的低成本电源管理芯片或直流电源模块通常并未集成输出均流控制功能,因此不能直接并联输出使用。而使用特殊的电源管理芯片或是额外的均流控制电路会提高电源电路的复杂程度,造成电路成本的提高。针对此应用场景,提出了一种具... 详细信息

广泛使用的低成本电源管理芯片或直流电源模块通常并未集成输出均流控制功能,因此不能直接并联输出使用。而使用特殊的电源管理芯片或是额外的均流控制电路会提高电源电路的复杂程度,造成电路成本的提高。针对此应用场景,提出了一种具有主动均流功能的双路电源开关,作为负载开关或电源多路复用器应用于电路之中,利用开关电流的方法均分输出电流,在几乎不增加电路成本的同时对两路电源进行均流。阐述了所提双路电源开关的工作原理与参数设计方法,并通过仿真与实验证明了所提方法的正确性与可行性。

关键词：主动均流电源开关负载开关电源多路复用器