Distributed robust power control in two-tier vehicle networks under uncertain channel environments

This paper proposes a novel optimization scheme to support stable and reliable vehicle-to-everything connections in two-tier networks,where the uplink channel of the cellular user is reused by underlay vehicle-to-vehicle communications.However,considering complex channel fading and high-speed vehicle movement,the cer-tainty assumption is impractical and fails to maintain power control strategy in reality in the traditional statical vehicular networks.Rather than the perfect channel state information assumption,the first-order Gauss-Markov process which is a probabilistic model affected by vehicle speed and fading is introduced to describe imperfect channel gains.Moreover,interference management is a major challenge in reusing communications,especially in uncertain channel environments.Power control is an effective way to realize interference management,and optimal power allocation can ensure that interference of the user meets the communication requirements.In this study,the sum-rate-oriented power control scheme and minimum-rate-oriented power control scheme were implemented to manage interference and satisfy different design objectives.Since both of these schemes are non-convex and intractable,the Bernstein approximation and successive convex approximation methods were adopted to transform the original problems into convex ones.Furthermore,a novel distributed robust power control al-gorithm was developed to determine the optimal solutions.The performance of the algorithm was evaluated through numerical simulations,and the results indicate that the proposed algorithm is effective in vehicular communication networks with uncertain channel environments.

A two-tier location management mechanism for IMS

This paper proposed a two-tier location management mechanism （TTLM） by improving the current registration mechanism （CR） in IP Multimedia Subsystem （IMS）. The TTLM includes the visited network registration and the home network registration, in which the visited network registration is responsible for re-registration in IMS. When subscriber roams, the location information of home network will be updated by the visited network based on the change of user equipment （UE）＇ s IP address. Thereibre the TTLM can reduce the times of IMS registration signaling. Using the proposed analytical model, the performance of the CR and the proposed TTLM were investigated. After the performance analysis of CR and TTLM by using proposed analytical model, the cost of CR in IMS could significantly be reduced theoretically and also was proven by simulation experiments.

INTERFERENCE COORDINATION METHOD BASED ON GRAPH THEORY IN TWO-TIER CELLULAR NETWORKS

This paper studies an interference coordination method by means of spectrum allocation in Long-Term Evolution (LTE) multi-cell scenario that comprises of macrocells and femtocells. The purpose is to maximize the total throughput of femtocells while ensuring the Signal-to-Interference plus Noise Ratio (SINR) of the edge macro mobile stations (mMSs) and the edge femtocell Mobile Stations (fMSs). A new spectrum allocation algorithm based on graph theory is proposed to reduce the interference. Firstly, the ratio of Resource Blocks (RBs) that mMSs occupy is obtained by genetic algorithm. Then, after considering the impact of the macro Base Stations (mBSs) and small scale fading to the fMS on different RBs, multi-interference graphs are established and the spectrum is allocated dynamically. The simulation results show that the proposed algorithm can meet the Quality of Service (QoS) requirements of the mMSs. It can strike a balance between the edge fMSs' throughput and the whole fMSs' throughput.

Two-tier control structure design methodology applied to heat exchanger networks

Because of its paramount importance in the successful industrial control strategy of a given heat exchanger network(HEN),the control structure designs for providing appropriate manipulated variable(MV)and controlled variable pairings have received considerable attention.However,quite frequently HENs with such control structures face the problem of hard constraints,typically holding the HENs at less controlled operating space.So both the MV pairings and the above control pairings should be considered to design a control structure.This paper investigates the systematic incorporation of the two pairings,and presents a methodology for designing such two-tier control structure.This is developed based on the sequential strategy,coupling an indirect-tier with direct-tier control structure design,wherein the intention is realized in the former stage and the latter is implemented for further optimization.The MV identification and pairing are achieved through variations in heat load of heat exchangers to design the indirect-tier control structure.Then the direct-tier control structure is followed the relative gain array pairing rules.With the proposed methodology,on the one hand,it generates an explicit connection between the MV pairings and the HEN configuration,and the quantitative interaction measure is improved to avoid the multiple solutions to break the relationship among all the control pairings into individuals;on the other hand,a two-tier control structure reveals control potentials and control system design requirements,this may avoid complex and economically unfavourable control and HEN structures.The application of proposed framework is illustrated with two cases involving the dynamic simulation analysis,the quantitative assessment and the random test.

A New Handover Management Model for Two-Tier 5G Mobile Networks

There has been an exponential rise in mobile data traffic in recent times due to the increasing popularity of portable devices like tablets,smartphones,and laptops.The rapid rise in the use of these portable devices has put extreme stress on the network service providers while forcing telecommunication engineers to look for innovative solutions to meet the increased demand.One solution to the problem is the emergence of fifth-generation(5G)wireless communication,which can address the challenges by offering very broad wireless area capacity and potential cut-power consumption.The application of small cells is the fundamental mechanism for the 5Gtechnology.The use of small cells can enhance the facility for higher capacity and reuse.However,it must be noted that small cells deployment will lead to frequent handovers of mobile nodes.Considering the importance of small cells in 5G,this paper aims to examine a new resource management scheme that can work to minimize the rate of handovers formobile phones through careful resources allocation in a two-tier network.Therefore,the resource management problem has been formulated as an optimization issue thatwe aim to overcome through an optimal solution.To find a solution to the existing problem of frequent handovers,a heuristic approach has been used.This solution is then evaluated and validated through simulation and testing,during which the performance was noted to improve by 12%in the context of handover costs.Therefore,this model has been observed to be more efficient as compared to the existing model.

我国上市公司投资非效率的动态识别与预警——基于Two-tier Stochastic frontier的视角

本文运用双边随机前沿模型取代Richardson(2006)模型,运用MLE估计优化OLS估计,提出了双边随机前沿模型更有利于解决人们应对非效率投资问题的设想,构建了对公司非效率投资展开高效分析和合理建议的新型工具。结果表明:双边随机前沿模型的MLE估计能胜任对非效率投资的快捷识别及预警工作,同时发现现行我国上市公司投资整体状况为投资不足,极端非效率投资现象并不多见,轻度非效率投资的企业需要关注拉升投资行为的不良后果,重度非效率投资的企业需要谨防压低投资的负面效应,自由现金流有加大过度投资的倾向,负债率有诱发投资不足的风险。

计及不确定性的风光抽蓄发电系统容量优化

风光等新能源的大规模利用是实现双碳目标的重要途径,其不确定性影响电力系统稳定运行和对新能源的消纳能力。对此,本文提出了一种计及不确定性的风光抽蓄联合发电系统容量优化配置方法。首先,采用不同的随机分布函数来描述风电、光伏发电的出力特性和负荷分布情况,建立了互补发电系统数学模型;其次,构建了基于信息间隙决策理论与熵权法的双层容量优化配置模型;最后,采用多元宇宙优化算法求解容量优化配置方案。算例结果表明,投资者可以根据投资意愿,对源荷不确定性采取不同的配置策略,所得的运行结果均能很好地满足不同运行模式和多种运行场景的要求;能有效地降低综合成本、提高新能源消纳能力,并且能保持抽蓄电站的长久运行。

自然资源监管视域下的国土空间规划管理探析:基于空间开发权配置的探讨

基于两级空间开发权理论,分析面向统一国土空间用途管制的自然资源监管流程,探讨国土空间规划管理在自然资源监管中发挥的具体作用,并从空间开发权视角出发,辨析国土空间规划管理背后隐含的两级空间开发权“批发—零售”基本逻辑。在此基础上,提出完善自然资源监管视域下国土空间规划管理的建议,即强化“区域—要素”统筹,发挥主体功能区战略和制度作用,在规划实施中完善各级“区域”的一级空间开发权 “批发”配置机制;进一步探索完善分级分类的空间开发权交易制度,促进规划安排的自然资源开发保护责任落实和国土空间格局优化。

双层法益视角下高空抛物罪的教义学分析与规范适用

高空抛物罪保护双层法益:公共秩序是“阻挡层法益”,人的生命、健康、财产等个人法益是“背后层法益”,在功能上,两者之间是手段与目的关系。高空抛物罪司法判断的关键在于以双层法益为指引对该罪构成要件进行合理解释,厘定处罚范围,为高空抛物罪与其他罪名和民事侵权之间的界分提供依据。一方面,基于双层法益指引,对行为要件、高空、情节严重、主观故意等构成要件予以实质性解释。另一方面,将高空抛物罪第2款视为想象竞合,结合已有的立法与司法解释,理清本罪与其他犯罪的竞合关系与适用规则。

水平地震作用下双级加筋土挡墙损伤识别研究

因对台阶式加筋土挡墙损伤识别的研究不足,开展了双级加筋土挡墙的大型振动台试验。采用时域识别方法分析了水平地震作用下模型的动力响应特征,阐述了上、下级挡墙自振频率、阻尼比的分布规律,探究了结构损伤程度与自振频率、阻尼比间的对应关系。研究结果表明:加载前上、下级挡墙的自振频率基本一致,阻尼比随墙高的增加而减小;随着加载工况的累积,自振频率逐渐减小,阻尼比逐渐增大。采用数学方法对自振频率和阻尼比分布曲线进行多项式拟合,对比分析可得:当自振频率减小0~15.41%、阻尼比增大0~299.35%时,结构处于基本完好阶段;当自振频率减小15.41%~18.92%、阻尼比增大299.35%~360.07%时,结构处于轻微破坏阶段;当自振频率减小18.92%~21.29%、阻尼比增大360.07%~398.21%时,结构处于中等破坏阶段;当自振频率减小21.29%~29.60%、阻尼比增大398.21%~532.99%时,结构处于毁坏状态。

阶梯成本下考虑混合租建模式的云储能优化配置

为解决盲目投建云储能造成资源浪费、成本增加的问题,提出阶梯成本下“自建+租赁”混合模式的园区云储能优化配置方法。首先,分析云储能的特点,构建园区内有大量光伏用户参与的云储能服务模式。其次,建立不同时间尺度、双主体的双层优化模型,上层求解长时间尺度下云储能的规划问题,下层求解短时间尺度下用户群的运行问题。然后,通过KarushKuhn-Tucker(KKT)条件将双层模型转化为单层模型,再利用Big-M法对所得单层模型进行线性化处理。最后,在3个不同场景下进行算例分析,结果验证了所提云储能配置模型的有效性,在降低储能投资成本、提高储能资源利用率的同时可节省用户用电成本。

分时电价下含电动汽车的微电网群双层多目标优化调度

为解决大规模电动汽车无序充电导致电网出现“峰上加峰”现象,依据电动汽车充电地点的不同将配电网划分为居民区、办公区、商业区微电网,提出基于峰谷差、分时电价、用户充电满意度多目标下的电动汽车充电模式,建立了微电网内运营商峰谷差最小—用户充电费用最少和充电满意度最大的双盈多目标优化调度模型,采用上海市实际居民办公商业混合体,基于MATLAB/NSGA⁃Ⅱ算法求解负荷整形度;采取粒子群优化算法求解电动汽车车主达到充电最优满意度;实现对电动汽车充电时刻和充电功率的引导。实际算例仿真结果表明,该方法能有效降低配电网负荷峰谷差,提高电动汽车充电效率,满足用户充电需求。

能源转型下基于碳排放与新能源阶梯惩罚的抽水蓄能双层优化研究

伴随“双碳”目标推进,高比例新能源并网,火电有序退役,抽蓄作为灵活性调节资源加快建设,合理规划是确保电力系统多能源稳定、可持续转型的重中之重。首先,本文针对高比例新能源场景,开展抽水蓄能容量规划及调度优化方法研究,以系统各电源全寿命周期成本、碳排放和弃电惩罚成本最小化为上层优化目标,以系统各电源碳排放量和风光出力波动最小化作为下层优化目标,构建抽水蓄能双层优化模型。然后,本文研究了星鸦算法与遗传算法、灰狼算法各自的优劣性,通过对星鸦算法参数自适应优化,得到具备更佳寻优能力与速度的算法,结合CPLEX对双层优化模型求解。最后,通过引入碳排放与新能源弃电阶梯惩罚机制,对模型上下层优化目标起到促进作用。算例结果表明,该区域电网中抽水蓄能需加快建设约74.21%,火电需合理退役约40.79%,同时构建模型能够有效降低系统综合成本约5.80%,减少弃风弃光约20.43%,降低系统碳排放量约25.96%,平抑风光出力波动约1.18%,验证了模型的有效性与合理规划的重要性,为电力系统中长期规划提供参考。

双层存款乘数框架下的货币乘数

主流文献关于存款乘数和货币乘数的认识在理论逻辑上存在着易被忽视的缺陷,与实践逻辑也不完全一致。一是忽视了对中央银行-商业银行层面存款派生机制的考察,仅从商业银行-客户的层面分析存款乘数;二是将货币乘数中的“货币”界定为包含商业银行准备金存款在内的基础货币,夸大了货币乘数的分母,降低了货币乘数的倍数;三是将法定存款准备金率从中央银行对单家或若干家商业银行的调控效应扩展到整个商业银行系统,过度高估法定存款准备金率在货币政策操作中的功效。本文提出基于双层存款派生乘数的货币乘数理论,指出法定存款准备金率的误区,将货币乘数中的“货币”界定为中央银行发行的“流通中货币”,重新梳理中国和美国货币政策实践中的货币乘数变化趋势。

An efficient and DoS-resistant user authentication scheme for two-tiered wireless sensor networks

Wireless sensor networks (WSNs) are vulnerable to security attacks due to their deployment and resource constraints.Considering that most large-scale WSNs follow a two-tiered architecture,we propose an efficient and denial-of-service (DoS)-resistant user authentication scheme for two-tiered WSNs.The proposed approach reduces the computational load,since it performs only simple operations,such as exclusive-OR and a one-way hash function.This feature is more suitable for the resource-limited sensor nodes and mobile devices.And it is unnecessary for master nodes to forward login request messages to the base station,or maintain a long user list.In addition,pseudonym identity is introduced to preserve user anonymity.Through clever design,our proposed scheme can prevent smart card breaches.Finally,security and performance analysis demonstrates the effectiveness and robustness of the proposed scheme.

考虑共享储能参与不同能量调频联合市场的优化策略

随着新型电力系统的构建,对储能运营商的运营策略提出了更高的要求。本文在共享理念背景下,构建了一种共享储能参与不同能量-调频联合市场的双层博奔模型。首先,上层模型为共享储能运营商报价优化模型,旨在动态生成共享储能各市场报价信息,下层模型为市场各主体联合出清模型,旨在降低系统运营总成本。其次,采用非线性互补方法将双层优化问题转化为单层优化问题,并通过算例验证。然后,对比了储能在不同调频辅助服务市场运营模式下的收益情况,结果表明共享储能在调频辅助服务市场的参与度远高于电能量市场,其承担的调频里程任务占比高达96.7%;同时,相较于仅形成调频容量价格,在完善的价格体系下共享储能的回收成本周期会缩短2~3年,可进一步激励储能电站的发展。

风险社会条件下行政追偿模式的解析与完善

在国家赔偿与追偿制度的发展过程中,追偿制度的功能发挥不够充分,其规范化程度不足,实践成效未达至理想状态。问题的根源在于对行政追偿性质定位不明,制度功能层面存在认识误区。根据我国行政法的规定,国家赔偿与追偿共同构成双阶层责任分配体系,在制度功能意义上应当实现分阶段运行的国家、公务员和受害人三方主体的利益平衡机制,因而需在整体视域下对两个阶段、三方主体予以系统性观察。目前在国家赔偿的“自己责任说”与“代位责任说”视角下的两种追偿主张均存在某种不足之处,而风险归责视角下的“组织责任说”能克服责任归属平面化、单一化的弊端,依“组织责任说”建构的国家赔偿与追偿的双阶层责任分配体系,通过统合自己责任、代位责任与混合责任,增强了该体系的适应性。从风险分配的视角重新审视过错界定,体现了行政追偿从外部责任向内部责任的转向,但行政追偿权仍然是法律明文授予的单方决定权,并非单纯的内部惩戒权。该项制度的功能在于以矫正正义为宗旨,对前一阶段国家赔偿责任的再分配。

劳动关系的平衡与分化:基于工资议价的谈判地位测算

伴随生产力和生产方式的变化,劳动关系发生变革,对劳动保护制度提出了新的挑战。在工资议价的理论框架下,运用2003—2021年中国综合社会调查数据和双边随机前沿模型,测算雇佣双方谈判地位并比较其结构差异,发现总体上我国雇佣双方谈判地位的差距有所缩小,劳动关系呈现平衡发展的趋势,但谈判地位随雇佣双方特征及雇佣组合呈现出明显的异质性,男性、已婚、少数民族和城镇户籍的劳动者更具谈判优势,“农村户籍—国有企业”“低人力资本—大规模企业”雇佣组合劳动者谈判地位较低。因此,完善现行劳动保护制度有必要以谈判地位为依据,针对不同雇员、雇主和特定雇佣关系进行分类调整,真正实现劳动关系的实质平等。

虚拟世界“涌现”下数字财产交易的双层法律关系解构

数字财产属于物权客体、债权客体、知识产权客体、新型权利客体的争论均局限于数字财产“去中心化”的特征,忽略了数字财产“去人化”的本质。虚拟世界系一独立的世界,而并非现实世界的附属空间,数字财产为虚拟世界的“物”;数字财产的财产所有人并非账号持有人,而是账号系统本身。数字财产交易是跨越“虚拟世界”和“现实世界”的交易,这一交易存在四方交易主体。在数字财产交易过程中,如果不可替代的标的属于现实的财产或服务,则其本质属于现实世界的交易,应当根据现实标的计算交易价值;如果不可替代的标的属于数字财产,则其本质属于虚拟世界的交易,应根据数字财产计算交易价值。

金融强国视角下地方金融“央—地”双层监管体制的路径完善

为有效防范地方金融风险的产生和蔓延,我国逐渐构建起地方金融“央—地”双层监管体制,但实践效果不够理想,存在“央—地”价值取向不同、法律依据缺失、“央—地”监管范围不明、权责失衡、信息不对称以及地方政府的能力不足等现实问题。国家需要结合现实需求加强高位阶的立法、变革金融监管理念、明晰“央—地”金融监管范围和权责界限、建立信息共享平台以及设置相应的外部监督问责制度,促进“央—地”之间形成金融监管合力,依法共治。