An Incremental LOD Method Based on Grid and Its Application in Distributed Terrain Visualization

Incremental LOD can be transmitted on the network as a stream, then users on the clients can easily catch the skeleton of terrain without downloading all the data from the server. Detailed information in a local part can be added gradually when users zoom it in without redundant data transmission in this procedure. To do this, an incremental LOD method is put forward according to the regular arrangement of grid. This method applies arbitrary sized grid terrains and is not restricted to square ones with a side measuring 2 k + 1 samples. Maximum height errors are recorded when the LOD is preprocessed and it can be visualized with the geometrical Mipmaps to reduce the screen error.

Symbol Error Probability of Incremental Relaying with Distributed/Centralized Relay Selection

In this paper,we derive the Symbol Error Probability(SEP)of cooperative systems with incremental relaying and Distributed Relay Selection(DRS).The relays remain idle when the Signal to Noise Ratio(SNR)between the source and destination is larger than T.Otherwise,we activate a relay using DRS.Relay nodes transmit only if their SNR is larger than thresholdβ.If the SNRs of more than two relays is larger thanβ,there is a collision and the destination uses only the received signal from the source.If all relays have SNR less thanβ,no relay is chosen.Thresholdβis optimized to yield the lowest SEP at the destination.Our results are compared to centralized relay selection using opportunistic Amplify and Forward(OAF),Partial and Reactive Relay Selection(PRS and RRS).We compare our results to computer simulations for Rayleigh fading channels.

iHDFS: A Distributed File System Supporting Incremental Computing

Big data are always processed repeatedly with small changes, which is a major form of big data processing. The feature of incremental change of big data shows that incremental computing mode can improve the performance greatly. HDFS is a distributed file system on Hadoop which is the most popular platform for big data analytics. And HDFS adopts fixed-size chunking policy, which is inefficient facing incremental computing. Therefore, in this paper, we proposed iHDFS (incremental HDFS), a distributed file system, which can provide basic guarantee for big data parallel processing. The iHDFS is implemented as an extension to HDFS. In iHDFS, Rabin fingerprint algorithm is applied to achieve content defined chunking. This policy make data chunking has much higher stability, and the intermediate processing results can be reused efficiently, so the performance of incremental data processing can be improved significantly. The effectiveness and efficiency of iHDFS have been demonstrated by the experimental results.

Thickness distribution of multi-stage incremental forming with different forming stages and angle intervals

Although multi-stage incremental sheet forming has always been adopted instead of single-stage forming to form parts with a steep wall angle or to achieve a high forming performance, it is largely dependent on empirical designs. In order to research multi-stage forming further, the effect of forming stages(n) and angle interval between the two adjacent stages(Δα) on thickness distribution was investigated. Firstly, a finite element method(FEM) model of multi-stage incremental forming was established and experimentally verified. Then, based on the proposed simulation model, different strategies were adopted to form a frustum of cone with wall angle of 30° to research the thickness distribution of multi-pass forming. It is proved that the minimum thickness increases largely and the variance of sheet thickness decreases significantly as the value of n grows. Further, with the increase of Δα, the minimum thickness increases initially and then decreases, and the optimal thickness distribution is achieved with Δα of 10°.Additionally, a formula is deduced to estimate the sheet thickness after multi-stage forming and proved to be effective. And the simulation results fit well with the experimental results.

ON THE INCREMENTS DISTRIBUTION OF STOCK PRICES

In this paper,the models of increment distributions of stock price are constructed with two approaches. The first approach is based on limit theorems of random summation. The second approach is based on the statistical analysis of the increment distribution of the logarithms of stock prices.

Incremental Static Analysis of 2D Flow by Inter-Colliding Point-Particles and Use of Incompressible Rhombic Element

A simple method is proposed, for incremental static analysis of a set of inter-colliding particles, simulating 2D flow. Within each step of proposed algorithm, the particles perform small displacements, proportional to the out-of-balance forces, acting on them. Numerical experiments show that if the liquid is confined within boundaries of a set of inter-communicating vessels, then the proposed method converges to a final equilibrium state. This incremental static analysis approximates dynamic behavior with strong damping and can provide information, as a first approximation to 2D movement of a liquid. In the initial arrangement of particles, a rhombic element is proposed, which assures satisfactory incompressibility of the fluid. Based on the proposed algorithm, a simple and short computer program (a “pocket” program) has been developed, with only about 120 Fortran instructions. This program is first applied to an amount of liquid, contained in a single vessel. A coarse and refined discretization is tried. In final equilibrium state of liquid, the distribution on hydro-static pressure on vessel boundaries, obtained by proposed computational model, is found in satisfactory approximation with corresponding theoretical data. Then, an opening is formed, at the bottom of a vertical boundary of initial vessel, and the liquid is allowed to flow gradually to an adjacent vessel. Almost whole amount of liquid is transferred, from first to second vessel, except of few drops-particles, which remain, in equilibrium, at the bottom of initial vessel. In the final equilibrium state of liquid, in the second vessel, the free surface level of the liquid confirms that the proposed rhombing element assures a satisfactory incompressibility of the fluid.

Distributed Adaptive Learning Framework for Wide Area Monitoring of Power Systems Integrated with Distributed Generations

This paper presents a preliminary study of developing a novel distributed adaptive real-time learning framework for wide area monitoring of power systems integrated with distributed generations using synchrophasor technology. The framework comprises distributed agents (synchrophasors) for autonomous local condition monitoring and fault detection, and a central unit for generating global view for situation awareness and decision making. Key technologies that can be integrated into this hierarchical distributed learning scheme are discussed to enable real-time information extraction and knowledge discovery for decision making, without explicitly accumulating and storing all raw data by the central unit. Based on this, the configuration of a wide area monitoring system of power systems using synchrophasor technology, and the functionalities for locally installed open-phasor-measurement-units (OpenPMUs) and a central unit are presented. Initial results on anti-islanding protection using the proposed approach are given to illustrate the effectiveness.

Distribution of Land Increment Income from Marketing Rural Collective Land for Development Purposes : A Case Study of Changyuan City

In order to protect the property rights and interests of farmers,promote the revitalization and development of rural areas,and provide a reference basis for the reform of marketing rural collective land for development purposes,this study explores the reasonable distribution proportion of land increment income from marketing rural collective land for development purposes through analytic hierarchy process and Delphi expert scoring method.The results show that there is a positive correlation between land increment income and land grade,that is,the higher the land grade,the higher the increment income,the larger the proportion of increment income to the transaction price.According to the calculation,when marketing rural collective land for development purposes,the reasonable distribution proportion of the land increment income of the government and the village collective is 28.6%and 71.4%,respectively,and the land increment income actually obtained by farmers has been greatly improved compared with the current situation.In practice,this distribution model has universal applicability and long-term mechanism.The reform of marketing also needs to improve the standard of marketing,explore diversified channels to protect interests,and strengthen the construction of rural collective management system.In short,the distribution of land increment income from marketing rural collective land for development purposes should proceed from the perspective of land property rights and the factors affecting the price of collective land for development purposes,in order to build a reasonable income distribution model.

Incremental Pressing Technique in Explosive Charge

A pressing technique has become available that might be useful for compressing granular explosives. If the height diameter ratio of the charge is unfavorable,the high quality charge can not be obtained with the common single action pressing. This paper presents incremental pressing technique, which can obtain the charge with higher overall density and more uniform density.

基于分布式潮流控制器的海上风电系统谐波治理方法和控制策略

由于电力电缆的电容效应,海上风电经电缆汇集系统极易出现谐波谐振放大的现象,造成电能质量的下降。分布式潮流控制器属于基于电压源换流器的装置,在进行潮流调节的同时也能进行谐波治理。文中首先构建了海上风电系统的频域相关模型,基于该模型分析了谐波谐振放大的原因;随后,采用了将分布式潮流控制器串入海上风电系统的谐波治理方式,推导并得到了含分布式潮流控制器的海上风电系统的谐波特性。基于该谐波特性,设计了一种控制策略。该策略通过控制分布式潮流控制器实时跟踪使并网点谐波电压幅值为零的谐波补偿电压,从而降低并网点的谐波电压含量。仿真结果表明,所提出的基于分布式潮流控制器的海上风电系统谐波治理方法和控制策略能够有效地降低并网点的谐波电压,改善电能质量。

协同性三次分配:贫困治理视域下农民农村共同富裕的实现机制

在“后2020时代”,相对贫困治理与共同富裕场域交叠、逻辑同构、成效相承,二者具有一体推进的关系,共同服务于中国式现代化的伟大实践。贫困治理视域下,要推进农民农村共同富裕,关键是要破解城乡空间资源配置失衡之“困”所致的农村之“贫”。协同性三次分配机制作为一种关系创新,通过资源要素回流、地方市场建构、农民无差受惠的“三重奏”,为城乡资源要素连接与激活、动能输入与转化提供制度性通道,改变了农村低水平的要素自循环与贫困再生产。它是渐进平衡贫困治理模式下联动、协同、演化三大功能整合互动的可操作化机制,通过三种分配形式的制度合力保障了相对贫困治理以发展为内容导向、以共享为价值导向、以均衡为目标导向,可有力有效推进农民农村共同富裕。

采用电流增量关联度的柔直配电线路双端量保护

针对有效提升多端柔性直流配电线路双端量保护动作速度以及抗干扰能力的问题,提出一种基于故障电流增量关联度比较的直流线路双端量快速保护方法。该方法利用直流线路两侧故障电流增量的变化特性,利用灰色T型关联度算法对故障电流增量的变化态势实测数据求解关联度,分别对正负极线路首末端电流增量序列的灰色T型关联度进行比较,实现线路故障的快速切除。通过在PSCAD/EMTDC平台搭建±10 kV多端柔性直流配电系统进行算例仿真分析,结果表明该保护方法可以准确判别区内外故障,保护实现流程原理简单,动作快速可靠,具有良好的适用性。

液压支撑单点渐进成形临界角研究

单点渐进成形复杂形状的薄壁制件时,不均匀厚度分布是影响产品性能和成形质量的主要原因。将液压支撑引入单点渐进成形过程中,提出一种液压支撑单点渐进成形工艺,该工艺通过对悬空板材增加柔性支撑来促进厚度的均匀分布。在静压和变压的辅助支撑下,采用Al1060板材单点渐进成形不同壁角的圆锥台制件,通过数值模拟和实验研究定量分析静压参数与变压方案对厚度分布及厚度均匀临界角的影响规律。结果表明,对厚度均匀分布临界角的有利静压压力范围为0~0.18 MPa,最有利的静压压力值为0.17 MPa。与无支撑单点渐进成形相比,液压支撑单点渐进成形工艺可以使厚度均匀临界角增大7°,有效提升板材的厚度分布均匀性和成形性能。

免疫性血小板输注无效患者HLA/HPA抗体特性分析及其对血小板输注效果的影响

目的 探讨免疫性血小板输注无效(PTR)患者HLA/HPA抗体特异性分布特征及其对血小板输注效果的影响。方法 本研究以86例免疫性PTR患者为研究对象,收集其性别、年龄、身高、体重、配血次数、疾病类型、输注前后血小板计数等临床资料,通过微珠法进行HLA特异性抗体的检测,并分析抗体特性对血小板输注效果的影响。结果 86例PTR患者中,单独HLA抗体、单独HPA抗体、HLA+HPA抗体阳性的患者分别为72例(83.72%)、8例(9.30%)、6例(6.98%)。HLA抗体在各位点中检出频率最高的抗体对应等位基因分别为A*25:01、B*15:12、C*02:02(和C*17:01),检出率分别为81.48%、87.04%、48.15%;而对应抗原表位出现频率最高的前三位为163LG、97V、71ATD,检出率分别为87.04%、77.78%、74.07%。仅存在HLA抗体的患者,输注交叉配型相合血小板的24 h血小板计数纠正增加指数(CCI)及输注有效情况均明显优于随机血小板(P<0.01)。在血小板交叉配型阴性结果的患者中,HLA抗体强度与交叉配型相合血小板的24 h CCI值及输注有效情况呈负相关关系,强度越高,输注效果越差(P<0.01)。HLA抗体强度为中、低等水平的患者,输注交叉配型相合血小板的24 h CCI值及输注有效情况均优于输注随机血小板(P<0.05)。结论 本研究所得到的PTR患者HLA/HPA抗体特性及其对血小板输注效果影响的结果,可为血小板库建立时供者的选择提供指导,同时对临床PTR患者的治疗方式选择有一定的参考价值。

基于增量交换的主动配电网分布式多目标最优潮流

接入高比例可再生能源的主动配电系统,配电网络运营商和能源运营商之间存在竞争与合作的复杂利益关系。为了提高分布式能源利用率,提出了一种基于增量交换的分布式多目标最优潮流(MO-OPF)算法。在MO-OPF模型中,网络运营商和能源运营商分布追求自己的运营目标,同时确保整个网络的电压和支路功率安全限制得到满足。该算法能够以分散的方式求解MO-OPF问题,而不会向网络运营商暴露任何能源运营商的私有信息。其核心思想是利用耦合变量增量的二次函数来描述能源运营商对网络运营商的影响,网络运营商通过求解累积二次规划问题来计算耦合变量的增量。以IEEE 33节点配电系统为例,验证所提方法不仅可以提供与使用集中式优化相同的帕累托最优解,而且具有电压调节能力。

基于增量成本的交直流混合微电网分级分布式控制策略

由于交直流混合微电网中分布式电源的成本各异,按照容量比例分配功率的下垂控制易造成系统成本较高,文中提出基于增量成本的下垂控制。为进一步解决线路阻抗不匹配对功率分配精度的影响,充分考虑微电网的经济运行,提出基于一致性算法的分级分布式控制策略。该控制策略分为子网级控制与系统级经济控制。子网级控制在基于增量成本的下垂控制中引入频率/电压二次控制项和成本二次控制项,恢复交流频率与直流电压,同时实现子网之间的分布式电源的经济功率分配。在系统级经济控制中引入“相对频率指数”与“相对电压指数”,构造双向互联变流器的本地控制策略,并进一步引入基于一致性算法的功率二次控制项,实现各分布式电源增量成本一致,从而达到系统全局最优的经济运行。最后,对交直流混合微电网模型进行仿真,验证了所提控制策略的有效性。

基于功率增量成本一致的源荷智能互动分布式协调控制

为了进一步促进配电网内分布式电源和用电负荷的交互作用,在分布式算法的基础上提出了一种基于功率增量成本一致的源荷智能互动分布式协调优化控制方法。首先,构建了包含分布式控制的配电网分层通信架构,并以区域发电成本最优为目标提出了领导者节点和邻居节点控制策略;然后,建立各发电节点的功率增量成本模型,运用一致性算法实现了配电网内部功率的优化分配;最后,通过负荷突增和负荷投切两种不同场景的仿真分析,验证了所提协调控制方法能满足配网内源荷智能互动平衡,使整体经济利益最优。结果表明与对比方法相比,该文方法具有更快的迭代更新速度和更好的经济以及动态控制性能。

一种支持增量更新的配电网单线图自动生成方法

针对配电网中鲜有对存量单线图进行增量更新和布局,提出一种支持增量更新的配电网单线图自动生成方法。首先,根据设备拓扑连接关系构建设备连接关系映射树,树根为电源;然后,对每个设备依据存量单线图坐标进行布局方向赋值,得到有布局方向的设备连接关系映射树;最后,根据设备布局方向逆向拼接,完成设备初始布局和局部收缩。根据设备连接关系完成布线,可得到一张继承了原有布局的配电网单线图。所提支持增量更新的配电网单线图自动生成方法已应用于配电网专题图自动生成系统开发,并通过工程实例进行验证。

“三权分置”下宅基地流转增值收益分配的制度构造

研究目的:针对“三权分置”下宅基地流转及经营性利用产生的土地增值收益,分析收益分配的理论依据及制度构造。研究方法:实证分析法和规范分析法。研究结果:在宅基地入市环节,农户依据宅基地使用权收益权能取得流转增值收益,农民集体依据集体所有权之收益权能参与收益分配;集体为成员提供共享利益构成其分配收益的合理边界。基于基础设施投入、产权交易服务以及再分配公平,政府应当通过税收方式参与二次分配。研究结论:为了保障集体和成员对宅基地流转增值收益的公平分配,立法应对集体分配收益的最低比例、用途、资金监管做出规定,同时赋予农村集体经济组织自治决议空间。宅基地入市环节应由农户缴纳所得税,再流转环节应当由转出方缴纳土地增值税,入市和再流转环节宅基地流入方均应缴纳契税。

基于二层邻居牵制一致性的并网微电网经济优化控制方法

为提高并网微电网系统经济优化响应速度,降低整体发电运行成本,提出二层邻居牵制一致性算法。该算法将成本微增率(incremental cost rate,ICR)定义为状态变量,引入功率偏差消除项快速消除总功率偏差,利用二层邻居项和牵制项实现快速收敛于最优ICR,计算得到各分布式电源(distributed generation,DG)的最优有功出力参考值。随后提出基于二层邻居牵制一致性的并网微电网经济优化控制方法。该方法基于构建的三层分布式分层架构,第一控制层为双闭环反馈的下垂控制,第二控制层采用电压频率优化控制,稳定系统的频率和电压,第三控制层将各DG最优有功出力参考值输出到P/f下垂控制层,从而实现系统经济优化以及负荷功率供需平衡的目标。最后搭建8个DG并联运行系统仿真模型进行仿真实验。仿真结果表明,所提方法能完成有功出力的经济分配,且系统响应性能优,在负荷突增、功率越限、分时电价、拓扑切换、计及线路损耗、即插即用等因素影响系统运行时,所提方法能使微电网快速达到经济优化状态。