高层建筑燃气供气系统及用户调压器的设计与应用

高层建筑燃气供气系统有其特殊性,只有了解高层建筑燃气供气方式,剖析高层建筑燃气供气存在的缺陷和不足,才能进行针对性的应对和补偿。同时,要进行用户调压器的合理应用,必须分析用户调压器的特性机理,进行附加压头处理方法的比选,才能有效解决高层建筑燃气供气系统中附加压头的问题。

用户调压器最佳结构参数匹配关系的研究

本文将用户调压器的结构参数与燃气管网的特点联系起来，应用概率统计方法，使设计出的用户调压器流量特性与管网的压力一流量特性相适应，从而保证了燃气用具处压力的稳定性，并得出了某一典型调压器结构参数之间的最佳匹配关系。

兼顾用户体验和光伏消纳的低压配电网电压协调控制方法

随着新型电力系统建设的推进,分布式光伏大规模接入低压配电网成为明显的趋势,由分布式光伏的随机性和波动性带来的用户侧电压大幅度波动问题成为低压配电网电压治理的挑战;此外,用户对用电体验的要求也在逐渐提高。针对此问题,以调压器和光伏作为调节资源,提出了一种兼顾用户体验和光伏消纳的低压配电网电压协调控制方法。首先,分别分析了调压器和光伏的控制原理,通过隶属度函数建立了用户调压感知度指标;其次,以用户调压感知度和弃光量作为目标函数,建立了双目标协同调压优化模型,并采用遗传算法对模型进行求解;最后,建立仿真模型,并设置多种对比场景对所提方法进行分析论证。结果表明,所提的低压配电网电压协调控制方法可以充分兼顾用户体验和光伏消纳,有效解决用户电压质量问题。

用户端调峰的有力举措——蓄冷空调技术

近年来,我国电网的装机容量虽然不断增长,但还不能够完全满足经济发展的要求,缺电情况时有发生。特别是不少地区电网内水电装机容量比重较低,抽水蓄能电站投运少,陆续建成的燃气轮机容量又较小,电网调度缺乏有效的调峰手段,调峰显得困难。因此,在夏季持续高温等情况下,用电高峰时遇有电力缺口只能采用成片限电或拉电的办法消极解决,对用户的生产、生活造成很大影响。

促进新能源消纳的用户侧调峰机制研究

针对促进提升新能源消纳的问题,考虑实际调度中电网运行、大工业用户及发电机组需求,对用户侧调峰机制进行研究。首先,考虑以电价作为激励,建立基于消费者心理学的用户响应模型,得到用户负荷转移率;其次,综合考虑不同时段负荷和新能源出力对"鸭子曲线"峰谷隶属度的贡献程度,改进隶属度函数,并通过确定阈值得到峰谷平时段划分;然后,在保证用户响应前后总用电费用变化在-1%~0的前提下,构建以新能源消纳最大化为目标的优化函数,并通过粒子群算法对于峰谷平时段的电价进行优化求解。最后,通过仿真实例结果可知,通过用户对于激励的响应,能有效促进新能源消纳。

源荷联动调峰辅助服务市场两阶段模型

新能源大规模并网给电力系统调峰带来巨大挑战,在电源侧深调空间逐步用尽的背景下,亟需高效的市场化机制引导用户侧可控负荷主动参与新能源辅助消纳。文中提出一种负荷聚合商参与的源荷联动调峰辅助服务市场框架,通过构建两阶段决策模型以实现考虑源侧深度调峰的用户侧调峰资源的市场化供给。其中,负荷聚合商测算其签约用户的需求侧响应容量及成本,基于边际效用进行竞价投标;火电机组测算其机组深度可调节能力,基于边际成本进行竞价投标,系统运营商建立采用随机机会约束规划方法的出清模型,实现源荷联动调峰市场出清。此外,进一步对市场的交易流程、出清规则及调控手段等关键问题进行了分析及探讨,算例结果验证了所提市场框架的有效性。

面向高比例新能源消纳的西北调峰辅助服务市场机制及实践

“源网荷”灵活互动是智能电网发展、电力市场化改革背景下能源系统转型升级的必然发展趋势,也是解决西北地区新能源调峰资源短缺、消纳空间不足的关键。梳理了国内外面向高比例新能源的“源”“荷”“网”及“源荷”联动下的辅助服务市场的市场机制、交易品种等关键技术及建设经验,立足西北电网的调峰瓶颈及障碍,基于现行西北区域省间调峰辅助服务市场平台,提出了适宜西北地区负荷特性及新能源消纳需求的“源网荷”联动调度模式及交易机制,以期利用市场杠杆与调度策略并行的调控手段,激发源网荷各主体调峰意愿,联动多主体协同参与调峰,共同促进西北地区新能源的全面消纳。

TZY-03型调压器多台并联装置

一、概况重钢生产、民用天然气为Ф48～426mm主干管网,运行压力为0.294 MPa。输送生产使用,设有八个不同等级调压站。TZy-03型调压器单台供民用住宅约40户,已装7500台供民用气将近三万户,均为重庆市仪表厂生产制造的,介质天然气,左进气右出气或右进气左出气,调压为4903P_a。

利于新能源消纳的大工业用户电价策略研究

随着可再生能源的不断发展和应用,新能源在减少能源消耗和环境保护方面具有巨大潜力,但在应用中发现新能源的波动性和间歇性对其消纳带来了一定的挑战,尤其对于大工业用户来说,如何合理利用新能源,提高消纳能力成为亟须解决的问题。旨在通过分析大工业用户的电力需求特点,构建调峰负荷模型,设计峰谷平时段划分策略,以及研究电价策略和优化模型,探索利于新能源消纳的大工业用户电价策略。通过合理引导大工业用户的用电行为,提高新能源的消纳能力,实现能源的可持续发展和环境的改善。

Joint jammer and user scheduling scheme for wireless physical-layer security

In order to improve the performance of the security-reliability tradeoff （SRT）, a joint jammer and user scheduling （JJUS） scheme is proposed. First, a user with the maximal instantaneous channel capacity is selected to transmit its signal to the base station （ BS） in the transmission time slot. Then, when the user transmits its signal to BS, the jammer is invoked for transmitting artificial noise in order to perturb the eavesdropper’s reception. Simulation results show that increasing the number of users can enhance the SRT performance of the proposed JJUS scheme. In addition, the SRT performance of the proposed JJUS scheme is better than that of the traditional round-robin scheduling and pure user scheduling schemes. The proposed JJUS scheme can guarantee the secure transmission even in low main-to-eavesdropper ratio（ MER） regions.

关于大中城市中压一级管网系统布置初探

对大中城市中压一级管网布置进行介绍 ,着重就这种一级管网布置的原因、布置方式及优点进行了阐述 ,以便在今后管网布置有一定借鉴。

天然气的中压到户供气及目前的实施原则

天然气输配管网一般为三级系统,即高、中、低压三级制供气。天然气以高压形式通过长输管线进入市区后,经过高中压调器,然后再以中压到户的形式供应中、小用户。天然气一般经过开采、净化处理,通过长输管线进入市区后,其压力仍高达几十个大气。

液化石油气小区供气方式初探

液化气小区管道供应,有很大优点值得推广。根据供应小区的情况来确定供应方式,以及根据不同用户数来计算管径进行小区设计。

Joint User Scheduling and Antenna Selection in Distributed Massive MIMO Systems with Limited Backhaul Capacity

Massive MIMO systems offer a high spatial resolution that can drastically increase the spectral and/or energy efficiency by employing a large number of antennas at the base station(BS).In a distributed massive MIMO system,the capacity of fiber backhaul that links base station and remote radio heads is usually limited,which becomes a bottleneck for realizing the potential performance gain of both downlink and uplink.To solve this problem,we propose a joint antenna selection and user scheduling which is able to achieve a large portion of the potential gain provided by the massive MIMO array with only limited backhaul capacity.Three sub-optimal iterative algorithms with the objective of sumrate maximization are proposed for the joint optimization of antenna selection and user scheduling,either based on greedy fashion or Frobenius-norm criteria.Convergence and complexity analysis are presented for the algorithms.The provided Monte Carlo simulations show that,one of our algorithms achieves a good tradeoff between complexity and performance and thus is especially fit for massive MIMO systems.

Adaptive resource allocation for multi-user multi-server power-line communication OFDM systems

The bits and power allocation model of adaptive power-rate mixture for multi-user multi-server power-line communication systems was analyzed with the restrictions of maximal total power,fixed rate for each real time (RT) user,minimal rate for each non-real time (NRT) user,maximal bits and power for each subcarrier in each orthogonal frequency division multiplexing (OFDM) symbol. An algorithm of resource dynamic allocation in the first OFDM symbol of each frame and resource optimal adjustment in the latter OFDM symbol of each frame was proposed. In the first OFDM symbol of every frame,resource is firstly assigned for RT users so as to minimize their total used power until satisfying their fixed rates; secondly the remainder resource of power and subcarriers are assigned for NRT users so as to minimize their total used power until satisfying their minimal rates also; lastly the remainder resource is again assigned for NRT users according to the proportional fairness strategy so as to maximize their total assigning rate. In the latter OFDM symbol of each frame,bits are swapped and power is adjusted for every user based on the resource allocation results of anterior OFDM symbol. The algorithm is tested in the typical power-line channel scenarios and the simulation results indicate that the proposed algorithm has better performances than the classical multi-user resource allocation algorithms and it realizes the multiple aims of multi-user multi-server resource allocation for power-line communication systems.

QoE-Aware Proportional Fair Scheduling for Multiuser Multiservice Wireless Networks

The effective radio resource allocation al-gorithms, which satisfy diversiform requirements of mobile naltimedia services in wireless cellular net-works, have recently attracted more and more at-tention. This paper proposes a service-aware scheduling algorithm, in which the Mean Opinion Score （MOS） is chosen as the unified metric of the Quality of Experience （QoE）. As the network needs to provide satisfactory services to all the users, the fairness of QoE should be considered. The Propor- tional Fair （PF） principle is adopted to achieve the trade-off between the network perfonmnce and us- er fairness. Then, an integer progranming problem is formed and the QoE-aware PF scheduling princi-ple is derived by solving the relaxed problem. Simu-lation results show that the proposed scheduling principle can perform better in terms of user fair-ness than the previous principle maximizing the sum of MOS. It also outperfoms the max-rain scheduling principle in terms of average MOS.

A self-regulating pairwise swapping algorithm to search reliability-based user equilibrium

The violation of monotonicity on reliability measures(RMs)usually makes the mathematical programming algorithms less efficient in solving the reliability-based user equilibrium(RUE)problem.The swapping algorithms provide a simple and convenient alternative to search traffic equilibrium since they are derivative-free and require weaker monotonicity.However,the existing swapping algorithms are usually based on linear swapping processes which cannot naturally avoid overswapping,and the step-size parameter update methods do not take the swapping feature into account.In this paper,we suggest a self-regulating pairwise swapping algorithm(SRPSA)to search RUE.SRPSA comprises an RM-based pairwise swapping process(RMPSP),a parameter self-diminishing operator and a termination criterion.SRPSA does not need to check the feasibility of either solutions or step-size parameter.It is suggested from the numerical analyses that SRPSA is effective and can swap to the quasi-RUE very fast.Therefore,SRPSA offers a good approach to generate initial points for those superior local search algorithms.

Exploration of Influential People for Viral Marketing

Exploration of influential people is really a hot issue for effective viral marketing these days. Prior studies overlooked to consider the influence of interaction between users and the authority of users during information dissemination. In this article, we proposed an innovative concept by employing communication strength and authority in order to explore the influential people. First, we calculated communication strength by three kinds of actions including retweets, comments and mentions. Second, we deliberated authority metric by employing total times getting re-tweeted, number of tweets and followers of a user. Then, we propose a novel algorithm called Influential People Label Propagation Algorithm(IPLPA) that considers the proposed metric to explore the influential people in micro-blog networks. We performed extensive experiments to measure the influence and rank of each person within micro-blog network. The comparative study presents that IPLPA depicted effective people while baseline algorithms retrieved low influenced people at top rank. Additionally, influence dissemination also measured for obtained influential people in order to validate proposed concept. The findings of this study would be useful for viral marketing and advertisement campaigns.

Interference Alignment and Cancellation Based Concurrent Transmission and Scheduling Scheme for Multiuser CR-MIMO System

In this paper,an Interference Alignment and Cancellation(IAC)based transmission and scheduling scheme is proposed for an infrastructured Cognitive Radio(CR)Multiple-Input Multiple-Output(MIMO)system with multiple secondary users.With the cooperation of Primary Base Station(PBS)and Secondary Base Station(SBS),a signal processing procedure is designed to guarantee the priority of the primary transmission.As a reward for offering help to the PBS,the SBS is granted communication opportunity.The transmission difference of various spatial channels is exploited in Secondary User(SU)scheduling.With the proposed scheme,interferencefree concurrent transmission of both PBS and SBS is implemented.Spatial channel resources can be effectively utilised compared with a traditional Interference Alignment(IA)based strategy.Simulation results show that the achievable data for primary transmission is enhanced by cooperative signal processing at the SBS.With respect to the SBS,its data rate grows with an increasing number of SUs by exploiting the multiuser diversity gain.

Bar in SILL Questionnaire for Multiple Results Processing： Users＇ Frequency and Confidence

One hundred and fifteen first-year students of Greek took the SILL （Strategy Inventory for Language Learning） questionnaire in an attempt to reveal and activate potential a successful and widely used questionnaire like SILL might have but not identified and investigated so far. The first original point to be investigated, tackled in a previous experiment （Kambakis-Vougiouklis, 2012）, concerns users＇ confidence whether their choice of a specific strategy is effective while the second point concerns the use of the bar as an alternative statistical tool. More specifically, in this particular experiment the bar is not divided only into five equal length spaces as in the first experiment but also into five equal area spaces according to Gauss distribution, giving the researcher the chance to investigate possible differences between two ways of data processing--an advantage only the use of the bar could provide in the analysis stage. Additionally, there are advantages concerning results collection, as subjects and researcher will have a completely free choice among infinite points on a line rather than a limited 3, 4, 5, and 6 of a Likert scale, avoiding at the same time fine verbal differences between different subdivisions. Although the two different methods of processing performed homogeneous behaviour with not statistically considerable differences, it needs further applications in order to reach safe conclusions