Energy Cost Minimization Using String Matching Algorithm in Geo-Distributed Data Centers

Data centers are being distributed worldwide by cloud service providers(CSPs)to save energy costs through efficient workload alloca-tion strategies.Many CSPs are challenged by the significant rise in user demands due to their extensive energy consumption during workload pro-cessing.Numerous research studies have examined distinct operating cost mitigation techniques for geo-distributed data centers(DCs).However,oper-ating cost savings during workload processing,which also considers string-matching techniques in geo-distributed DCs,remains unexplored.In this research,we propose a novel string matching-based geographical load balanc-ing(SMGLB)technique to mitigate the operating cost of the geo-distributed DC.The primary goal of this study is to use a string-matching algorithm(i.e.,Boyer Moore)to compare the contents of incoming workloads to those of documents that have already been processed in a data center.A successful match prevents the global load balancer from sending the user’s request to a data center for processing and displaying the results of the previously processed workload to the user to save energy.On the contrary,if no match can be discovered,the global load balancer will allocate the incoming workload to a specific DC for processing considering variable energy prices,the number of active servers,on-site green energy,and traces of incoming workload.The results of numerical evaluations show that the SMGLB can minimize the operating expenses of the geo-distributed data centers more than the existing workload distribution techniques.

Sustainable Lignin-Derived Carbon as Capacity-Kinetics Matched Cathode and Anode towards 4.5 V High-Performance Lithium-Ion Capacitors

The Li-ion capacitors(LICs)develop rapidly due to their double-high features of high-energy density and high-power density.However,the relative low capacity of cathode and sluggish kinetics of anode seriously impede the development of LICs.Herein,the precisely pore-engineered and heteroatomtailored defective hierarchical porous carbons(DHPCs)as large-capacity cathode and high-rate anode to construct high-performance dual-carbon LICs have been developed.The DHPCs are prepared based on triple-activation mechanisms by direct pyrolysis of sustainable lignin with urea to generate the interconnected hierarchical porous structure and plentiful heteroatominduced defects.Benefiting from these advanced merits,DHPCs show the well-matched high capacity and fast kinetics of both cathode and anode,exhibiting large capacities,superior rate capability and long-term lifespan.Both experimental and computational results demonstrate the strong synergistic effect of pore and dopants for Li storage.Consequently,the assembled dual-carbon LIC exhibits high voltage of 4.5 V,high-energy density of 208 Wh kg^(−1),ultrahigh power density of 53.4 kW kg^(−1)and almost zerodecrement cycling lifetime.Impressively,the full device with high mass loading of 9.4 mg cm^(−2)on cathode still outputs high-energy density of 187 Wh kg^(−1),demonstrative of their potential as electrode materials for high-performance electrochemical devices.

Study on Matching a 300 MVA Motor Generator with an Ohmic Heating Power Supply in HL-2M

A new 300 MVA/1350 MJ motor generator （MG） will be built to feed all of the poloidal field power supplies （PFPS） and auxiliary heating power supplies of the HL-2M tokamak. The MG has a vertical-shaft salient pole 6-phase synchronous generator and a coaxial 8500 kW induction motor. The Ohmic heating power supply （OHPS） consisting of 4-quadrant DC pulsed convertor is the one with the highest parameters among the PFPS. Therefore, the match between the generator and the OHPS is very important. The matching study with Matlab/Simulink is described in this paper. The simulation results show that the subtransient reactance of the generator is closely related to the inversion operation of the OHPS. By setting various subtransient reactance in the simulation generator model and considering the cost reduction, the optimized parameters are obtained as xd＂ = 0.405 p.u. at 100 Hz for the generator. The models built in the simulation can be used as an important tool for studying the dynamic characteristics and the control strategy of other HL-2M PFPSes.

Shape design of the reinforcement for bending load-carrying capacity of under-matched butt joint under four-point bending load

To improve the bending load-carrying capacity （ BLCC） of under-matched butt joint under four-point bending load in the elastic stage, the shape design of the reinforcement is studied based on the theoretics of mechanics of materials. The concept, criterion, realization condition and design proposal of equal bending load-carrying capacity （EBLCC） are put forward. The theoretical analysis results have been verified by the finite element method. The simulation results are coincident basically with the ones of theoretical analysis. The research results show that the shape design of the reinforcement of EBLCC can improve BLCC of under-matched butt joint and the unilateral-side type reinforcement can replace double-side symmetry

电力物联网用户侧负荷数据动态R-树匹配方法

电力物联网用户侧负荷数据维度较大,导致数据匹配延时时间过长,为了解决上述问题,基于动态R-树实现电力物联网用户侧负荷数据动态匹配。建立负荷计算模型,分析负荷历史运行信息,实现数据检测。通过归一化函数完成归一化处理,提取动态特征,构建动态R-树,确定匹配机制,根据矩阵计算函数完成压缩处理,利用动态匹配算法更新集对R-树内部结构进一步加以修改,在清除矩形之前,利用叶结点的Hash索引得到R-树匹配矩阵,使用Hash搜索准确地找到目标矩形,增强分布与交互仿真中的实时性,实现用户侧负荷数据动态匹配。实验结果表明,研究的动态R-树匹配方法在数据插入、数据匹配、数据维护过程中的延时时间低于48ms,实时性较好。

The Symbolic OBDD Algorithm for Finding Optimal Semi-matching in Bipartite Graphs

The optimal semi-matching problem is one relaxing form of the maximum cardinality matching problems in bipartite graphs, and finds its applications in load balancing. Ordered binary decision diagram (OBDD) is a canonical form to represent and manipulate Boolean functions efficiently. OBDD-based symbolic algorithms appear to give improved results for large-scale combinatorial optimization problems by searching nodes and edges implicitly. We present novel symbolic OBDD formulation and algorithm for the optimal semi-matching problem in bipartite graphs. The symbolic algorithm is initialized by heuristic searching initial matching and then iterates through generating residual network, building layered network, backward traversing node-disjoint augmenting paths, and updating semi-matching. It does not require explicit enumeration of the nodes and edges, and therefore can handle many complex executions in each step. Our simulations show that symbolic algorithm has better performance, especially on dense and large graphs.

基于风电-负荷匹配度的风电消纳能力自动评估方法

风力发电是一种绿色清洁发电技术,风能分布不均,存在着弃风问题,基于此,研究基于风电-负荷匹配度的风电消纳能力自动评估方法。创建风电-负荷场景,获取真实风电-负荷数据,计算风电-负荷匹配度,选取风电消纳能力自动评估指标,构建风电消纳能力自动评估模型,明确构建模型的约束条件,基于粒子群优化算法获取评估数值,根据评估规则确定风电消纳能力,实现风电消纳能力的自动评估。实验数据显示:应用提出方法获得的风电消纳能力自动评估时延最小值为11.4 s,评估结果误差最小值为2%,风电消纳能力评估效果更佳。

早老素-1基因启动子区-48C/T位点多态性与LOAD的遗传相关性

目的 研究早老素 - 1基因启动子区 - 4 8C/T位点的多态性与迟发性AD(LOAD)的相关性。方法 用常规方法从人外周血白细胞中抽提基因组DNA ,PCR扩增出包含 - 4 8C/T多态性位点的基因片段 ,利用PCR -RFLP技术对 -4 8C/T多态性位点进行基因分型 ,χ2 检验分析 - 4 8C/T多态性位点基因型分布和等位基因频率。结果 以 33例AD病例和32例对照样品的外周血白细胞基因组DNA为模板 ,PCR扩增出了长度为 344bp的包含 - 4 8C/T多态性位点的基因片段。基因分型结果表明 ,33例散发型AD的C和T等位基因频率分别为 4 7%和 5 3% ,C/T和T/T基因型频率分别为 94 %和 6 %。而 32例正常对照的C和T等位基因频率分别为 4 8%和 5 2 % ,C/T和T/T基因型频率分别为 97%和 3%。χ2 检验结果显示 ,病例 -对照样品间C和T等位基因频率及C/C、C/T和T/T基因型的分布均无显著性差异 (χ2 值分别为 0 4 4 3和 0 318,P>0 .0 5 )。结论 在我们研究的群体中 ,早老素 - 1基因启动子区 - 4 8C/T位点的多态性与LOAD无显著的遗传相关性。

基于Load-Pull系统的射频功率放大器的设计

射频功率放大器的设计一直是无线通信研究的热点,而关于它的设计方法也非常多样。基于实际搭建的Load-pull系统测试得到的数据设计实现了2.4GHz的GaAs场效应管的功率放大器。在没有大信号模型的情况下设计出的实际电路的输出功率为22dBm,功率增益为12dB,很好地实现了此GaAs场效应管的性能。相比其它传统的设计方法,Load-pull设计法简单、实用,能准确测试到场效应管的各项参数,简化了功率放大器的设计过程。

Topology optimization of 3D structures with design-dependent loads

Topology optimization of continuum structures with design-dependent loads has long been a challenge. In this paper, the topology optimization of 3D structures subjected to design-dependent loads is investigated. A boundary search scheme is proposed for 3D problems, by means of which the load surface can be identified effectively and efficiently, and the difficulties arising in other approaches can be overcome. The load surfaces are made up of the boundaries of finite elements and the loads can be directly applied to corresponding element nodes, which leads to great convenience in the application of this method. Finally, the effectiveness and efficiency of the proposed method is validated by several numerical examples.

Numerical study on wave loads and motions of two ships advancing in waves by using three-dimensional translating-pulsating source

A frequency domain analysis method based on the three-dimensional translating-pulsating （3DTP） source Green function is developed to investigate wave loads and free motions of two ships advancing on parallel course in waves. Two experiments are carried out respectively to mea- sure the wave loads and the free motions for a pair of side-by- side arranged ship models advancing with an identical speed in head regular waves. For comparison, each model is also tested alone. Predictions obtained by the present solution are found in favorable agreement with the model tests and are more accurate than the traditional method based on the three dimensional pulsating （3DP） source Green function. Numer- ical resonances and peak shift can be found in the 3DP pre- dictions, which result from the wave energy trapped in the gap between two ships and the extremely inhomogeneous wave load distribution on each hull. However, they can be eliminated by 3DTP, in which the speed affects the free sur- face and most of the wave energy can be escaped from the gap. Both the experiment and the present prediction show that hydrodynamic interaction effects on wave loads and free motions are significant. The present solver may serve as a validated tool to predict wave loads and motions of two ves- sels under replenishment at sea, and may help to evaluate the hydrodynamic interaction effects on the ships safety in replenishment operation.

Large deflections of non-prismatic nonlinearly elastic cantilever beams subjected to non-uniform continuous load and a concentrated load at the free end

This work studies large deflections of slen- der, non-prismatic cantilever beams subjected to a combined loading which consists of a non-uniformly distributed con- tinuous load and a concentrated load at the free end of the beam. The material of the cantilever is assumed to be non- linearly elastic. Different nonlinear relations between stress and strain in tensile and compressive domain are considered. The accuracy of numerical solutions is evaluated by com- paring them with results from previous studies and with a laboratory experiment.

Effect of Mild-calcined Coal Gangue Additionon Hot Strength and Refractoriness Under Loadof Ultra Low Cement Castablesin Al_2O_3-SiO_2 System

This work explored the way to improve hot modulus q/＇ rupture （HMOR） and refractoriness under load （RUL） by adding mild-calcined coal gangue （MCG） in Al2O3 -SiO2 ultra low cement （ULC） castables, making use of the in-situ effect of the MCG during heating-up. The influence of respective additions of 5%, 10% and 1.5% of the MCG powders calcined at 700℃ was investigated on HMOR at 1400 ℃ and RUL of the castables. With increased addition of the MCG, HMOR and RUL become significantly enhanced. At 10% of the MCG addition, HMOR reaches 3 MPa, as compared to 0. 3 MPa in the case of no MCG addition. RUL of the specimens dried at 110 ℃for 24 h can be increased by some 270 ℃ with 10% of the MCG addition. RUL 0.11 the specimens preheated at 1 500℃ for 3 h maintains the growth trend with the MCG addition increasing. The microstructure of the heated castable samples was investigated by means of SEM. The in-situ formed needle-like and interlaced mullite in the matrix is contributive to the tmprovement.

An Approach to the Maximum Independent Set for Surface Matching

In order to resolve the problem of surface match in the process of surface detection for aircraft thin-walled and composite parts, an efficient approach of 3D surface matching was proposed which is based on the Maximum Independent Set （MIS） algorithm of free surface matching. First, to introduce the MIS, this paper described the approach in detail. The MIS of matching points was finally solved by converting the surface matching into a sur- face matching of discrete points, establishing the distance matrix of discrete points, and constructing a 0-1 matrix using the error radius. Second, a validation case was used to show that the algorithm demonstrates good overall local and global surface matching efficiency.

基于改进K-means算法的源荷匹配电网优化分区

针对电网分区问题中基于经验的启发式方法的局限性,考虑分区问题中的新能源和负荷之间的匹配特性,建立电网优化分区的衡量指标;基于源荷匹配度,通过求解各区域的源荷匹配度系数,实现对电网进行优化分区;在传统K-means算法中引入误差平方和,筛选最佳聚类数值,规避聚类模型对分析结果的不利影响。算例采用某地区6座500 kV变电站运行数据,分析并计算了各主变压器下的源荷匹配度系数,并根据系数对该区域电网进行分区。结果表明,所提算法能有效均衡分区之间的短路能力,明显提升在整体聚类上的效果。

黄河流域河南段水资源空间均衡研究

基于水资源负载指数、水土资源匹配系数和用水效益系数等测算模型,研究了黄河流域河南段2011—2020年水资源空间均衡性.结果表明,黄河流域河南段8市水资源负载指数大致呈波动增长趋势且远大于10,水资源利用程度很高,基尼系数为0.31;水土资源匹配系数大致呈波动下降趋势且平均值为0.33,水土匹配程度较低,基尼系数为0.28;用水效益系数呈稳步上升趋势,单方水GDP产值为208元,用水效益与经济发展水平相对合理,基尼系数为0.32;水资源空间均衡系数平均值为0.55,空间均衡等级为Ⅲ级,属于一般失衡.基于此,合理配置水资源、提高用水效率、提前规划引水调水等有利于促进黄河流域河南段社会经济和水资源利用空间均衡发展.

基于磁耦合谐振的多自由度电机无线电能传输

针对多自由度电机无线电能传输中传输效率较低的问题,提出基于磁耦合谐振的多自由度电机无线电能传输方法。该方法根据共振原理构建磁耦合谐振式无线电能传输模型,通过反射系数描述阻抗匹配状态,获取最佳负载阻抗;采用混沌优化算法优化电机线圈损耗率,实现多自由度电机无线电能传输优化。实验结果表明,应用该方法后,多自由度电机的电能输出功率达到了893 W,传输效率提升了0.10以上,提高了电能输出功率和传输效率,方法有效,具备可行性。

发动机-变量泵功率匹配极限负荷控制

根据负荷多变工况条件下发动机—变量泵系统的节能要求,分析了发动机功率极限负荷的控制机理;运用转速传感控制原理,提出了变量泵随发动机功率变化进行功率匹配的动态调节方法;给出了发动机—电比例控制变量泵功率匹配控制方框图,推导出系统控制调节传递函数。实验证明:外负荷变化时变量泵吸收功率与发动机输出功率基本匹配,发动机无须功率储备就可以保持正常工作,节能效果明显。

发动机-变量泵极限负荷控制系统的设计与仿真

分析传统发动机-液压泵系统产生能量损失的原因,阐述发动机极限负荷控制的原理。根据极限负荷控制原理调节泵的排量,使泵吸收发动机最大扭矩,保证最大限度地利用发动机功率;跟随负载的变化,运用转速感应控制策略调节变量泵的吸收功率与发动机输出功率匹配,使发动机工作速度保持在节能效果突出的转速范围。运用AMES im软件对A8VO变量泵调节系统进行物理建模和仿真,验证系统转速感应控制策略的有效性,得出系统参数与其动态结果之间的相互关系。

考虑新能源爬坡的风光火耦合系统源荷匹配性分析及容量优化配置

风力发电、光伏发电与火力发电经同一点并网形成耦合系统,是我国北方地区发电侧灵活性调节电源与新能源间高效、低碳协同的一种形式.考虑区域新能源爬坡特性,结合源荷匹配分析,发掘和利用其规律,研究风光火耦合系统的容量优化配置方法,为耦合系统规划提供参考.首先,简述耦合系统运行模式和不确定性处理方法;其次,考虑耦合系统风光互补、爬坡事件和关键负荷特性,选取并提出相关指标用于源荷匹配评价;再次,考虑源荷特性、匹配、成本和收益等约束,建立耦合系统容量优化配置模型;最后,基于辽宁地区实际数据进行算例仿真,得到该地区耦合系统风、光的最优安装容量,并分析上述源荷相关因素与容量优化配置结果之间的相互影响,为新能源最优容量配置提供了参考与建议.