THE DESIGN AND ANALYSIS OF ALGORITHM OF MINIMUM COST SPANNING TREE

This paper provides a method of producing a minimum cost spanning tree (MCST) using set operations. It studies the data structure for implementation of set operations and the algorithm to be applied to this structure and proves the correctness and the complexity of the algorithm. This algorithm uses the FDG (formula to divide elements into groups) to sort (the FDG sorts a sequence of n elements in expected tir O(n)) and uses the method of path compression to find and to unite. Therefore. n produces an MCST of an undirected network having n vertices and e edges in expected time O(eG(n)).

A Parametric Approach to the Bi-criteria Minimum Cost Dynamic Flow Problem

This paper presents an algorithm for solving Bi-criteria Minimum Cost Dynamic Flow (BiCMCDF) problem with continuous flow variables. The approach is to transform a bi-criteria problem into a parametric one by building a single parametric linear cost out of the two initial cost functions. The algorithm consecutively finds efficient extreme points in the decision space by solving a series of minimum parametric cost flow problems with different objective functions. On each of the iterations, the flow is augmented along a cheapest path from the source node to the sink node in the time-space network avoiding the explicit time expansion of the network.

Bottleneck Analysis of the Minimum Cost Problem for the Generalized Network Based on Augmented Forest Structure

The bottleneck analysis of the minimum cost problem for the generalized network (MCPGN) is discussed. The analysis is based on the network simplex algorithm, which gains negative cost graphs by constructing augmented forest structure, then augments flows on the negative cost graphs until the optimal revolution is gained. Bottleneck structure is presented after analyzing the augmented forest structure. The negative cost augmented graphs are constructed with the bottleneck structure. The arcs that block the negative cost augmented graph are the elements of the bottleneck. The bottleneck analysis for the generalized circulation problem, the minimum circulation problem and the circulation problem are discussed respectively as the basal problems, then that for MCPGN is achieved. An example is presented at the end.

Minimum Cost of Capacity Expansion for Time-Limited Transportation Problem On-Demand

The minimum cost of capacity expansion for time-limited transportation problem on-demand (MCCETLTPD) is to find such a practicable capacity expansion transportation scheme satisfying the time-limited T along with all origins’ supply and all destinations’ demands as well as the expanding cost is minimum. Actually, MCCETLTPD is a balance transportation problem and a variant problem of minimum cost maximum flow problem. In this paper, by creating a mathematical model and constructing a network with lower and upper arc capacities, MCCETLTPD is transformed into searching feasible flow in the constructed network, and consequently, an algorithm MCCETLTPD-A is developed as MCCETLTPD’s solution method basing minimum cost maximum flow algorithm. Computational study validates that the MCCETLTPD-A algorithm is an efficient approach to solving the MCCETLTPD.

Minimum Living Cost Program in Zhejiang

The promulgation of the Rules represents a crucial step toward institutionalization and standardization of the minimum cost of living program, which marks the end of the arbitrariness in the traditional relief behavior. In a country, to what degree the citizens enjoy human rights, it depends on the law. The minimum cost of living system has to be ensured by law in its progress toward institutionalization and standardization. This has been testified by the history of the development of the social security systems, either in Germany, which is regarded as a pioneer in modern social security systems or the United States.

最低工资上调如何影响会计稳健性?

最低工资制度是政府管制劳动力市场、保护劳动者权益的重要手段,会对经济活动产生广泛而深远的影响。利用2008—2020年沪深A股上市公司和各城市最低工资数据,从会计稳健性视角考察最低工资上调对企业会计信息披露的影响。研究发现:最低工资上调显著提高了企业的会计稳健性,且该结论在经过一系列稳健性测试后仍然成立。作用机制检验结果表明,最低工资上调主要通过优化人力资源质量和降低企业风险承担水平促进了会计稳健性的提升。异质性分析显示,当企业劳动密集特征较强、平均工资较低、所处地区劳动力市场竞争激烈以及财务状况不佳时,最低工资上调对会计稳健性的提升作用更加显著。经济后果检验表明,在最低工资上调的环境下,企业可通过提高会计稳健性获得更多的银行贷款。

计及电-气双向耦合的综合能源配电网优化重构

综合能源系统是实现电网、气网以及热网等多种能源系统深度融合,利用能量耦合互补等优势提升整个系统能源利用效率的有效形式。为提升综合能源系统优化运行能力,文章首先基于电转气技术与天然气发电技术,构建了的电-气双向耦合综合能源系统总体模型。进而考虑配电网重构技术(Distribution Network Reconfiguration Technology,DNR)中拓扑结构灵活可控这一特性,在配电子系统中引入开关变量、系统运行总费用最低这一目标函数及网络辐射状拓扑结构等约束,建立了配电子系统重构模型。从降低模型求解复杂性的角度,应用二阶锥松弛、乘积变量线性化及分段线性化等方法,将原始综合能源配电网重构非凸非线性模型转化为混合整数二阶锥规划(Mixed Integer Second-Order Cone Programming,MISOCP)问题求解。仿真结果表明,在电-气双向耦合的综合能源系统中应用配电网重构技术,能够降低综合能源系统运行费用,同时有效支撑了配电子系统电压与配气子系统气压。

基于最小路由代价的巨型星座网络接入策略

针对低轨巨型星座网络星间路由复杂、网关卫星负载不均衡等问题,在星地接入策略中考虑星间路由代价,提出一种基于最小路由代价的接入策略。该策略分为3个阶段:在最短跳数估计阶段,根据用户终端和信关站位置估算用户终端至网关卫星的星间路由跳数;在网关卫星分配阶段,基于估计跳数建立二分图模型,采用带权最小代价匹配算法确定网关卫星和接入卫星类型;在接入卫星选择阶段,以星间路由跳数和星地仰角加权构造接入准则,在确定类型的可视卫星中选择最优接入卫星。仿真结果表明,所提方法能够显著降低系统整体星间路由跳数,提高网关卫星负载均衡性和用户接入成功率。

考虑电池老化的电动汽车中长期充电负荷预测方法

随着电动汽车市场份额逐年上升,受限于区域内动力电池容量大小的电动汽车充电负荷占总用电负荷的比例不断提高。为此,提出一种考虑电池老化的电动汽车中长期充电负荷预测方法。首先,构建考虑电池老化的区域电动汽车电池总容量预测模型,预测电池老化带来的总容量衰减以及更换新电池和车辆数目增长带来的总容量上升。其次,构建考虑温度变化的动力电池老化特性估计模型,预估每次充电后电池最大容量、可充电量和续航电量,当电池最大容量不足以保证车辆安全运行时,对车辆更换新电池。最后,构建考虑充电成本的车辆行为仿真模型,模拟车辆出行和充电过程;借助模糊C均值法对不同种类电动汽车充电负荷进行划分,通过蒙特卡洛模拟与线性加权确定区域内电动汽车中长期负荷。仿真结果表明,随着车辆使用时间的增加,年负荷曲线波动程度不断变大;相较于新车,电池老化后单位车辆周均用电负荷峰值出现的时间会提前,且负荷峰谷差也会增大。

光学立体测绘卫星影像高效密集匹配方法研究

针对半全局匹配(Semi-Global Matching,SGM)中代价聚合存在大量计算冗余的问题,文章提出了基于最小代价路径的快速代价聚合与视差确定方法。在代价聚合阶段,将SGM更新代价空间转变为最小代价路径确定,获取候选视差值集合,使得代价聚合计算量不再与视差范围相关,显著提升处理效率;在视差确定阶段,采用单个视差候选值与其它视差候选值差值的绝对值之和的倒数作为该视差候选值的支持度,统计所有视差候选值的支持度,从而可应用“赢者通吃”策略快速确定最终视差值。采用“资源三号”和“高分七号”卫星立体像对密集匹配对比实验验证该方法的有效性,结果表明该方法可在与SGM匹配结果保持一致的同时,将代价聚合处理效率提升90%。

Techno-economic and Environmental Assessments of SAF from Bioamss:An Review

This review presents a comprehensive techno-economic and life-cycle assessment of sustainable aviation fuel(SAF)production from biomass.The critical need for transitioning towards environmentally sustainable alternatives for liquid fuel and aviation industry is first discussed.Key insights encompass the evolutionary progression of biofuel production from first-generation to second-generation biofuels,with a focus on utilizing non-food sources like woody biomass for enhanced sustainability.Available data from the literature on techno-economic assessments of various SAF production pathways are analyzed including production costs,conversion efficiency,and scalability.Moreover,results of lifecycle assessments associated with different SAF production pathways are presented,providing essential insights for decision-making processes.The challenges of scaling up woody biomass-based SAF production are discussed based on the assessment results,and recommendations are proposed to steer stakeholders towards a greener and more sustainable trajectory for aviation operations.

基于低频采集数据的城市道路车辆轨迹重构

在进行城市道路交通流量调查及部分重要路网节点、交叉口交通数据采集时,采用低频数据收集方式会使车辆轨迹匹配精度低、交通流量数据误差大。通过研究隐式马尔可夫理论及最小费用最大流模型,提出一种车辆轨迹重构方法。该方法利用多源数据融合技术以及地理信息定位匹配技术,对无检测器路段缺失的各项交通基础数据进行合理的演进推算,为车辆轨迹重构研究提供重要的数据支撑。利用成都市某区域出租车的高频轨迹点位数据集进行验证。结果表明,利用车辆低频轨迹点位进行轨迹重构的完全覆盖率达到了89.4%,验证了所提出的车辆轨迹重构方法的有效性及可行性。

风电-光伏-抽蓄-电制氢多主体能源系统增益的合作博弈分配策略

根据清洁能源示范基地的建设需求,提出基于合作博弈论的风电-光伏-抽蓄-电制氢多主体能源系统联合优化运行的增益分配策略.为兼顾系统运行安全性,构建上网出力互补性评价指标.风电、光伏、抽蓄、电制氢利益主体通过内部电量交易进行合作,以系统运行收益最大为优化目标构建联合优化调度模型.根据调度结果,应用合作博弈论中的最大最小成本法分配系统合作增量收益.利用风电-光伏-抽蓄-电制氢清洁能源示范基地12利益主体系统算例进行仿真验证,结果表明联合优化运行可实现各利益主体自身收益正增长,抽蓄库容、上网电价以及运行安全性需求会影响系统的合作增量收益.

概率语言移情网络下的机会约束鲁棒大规模群体共识决策

本文旨在面向概率语言移情网络建立大规模群体共识决策方法,利用机会约束鲁棒优化方法处理单位调整成本的不确定性。首先,建立概率语言移情网络评估决策者间的移情关系。其次,利用模糊C-均值聚类对决策者分类,并基于聚类的规模、内聚度和总体移情度确定聚类权重。在反馈调整过程中,利用置信水平控制不确定参数的波动范围,建立机会约束鲁棒成本共识模型为决策者调整意见提供参考。最后,通过疫情防控方案选择的应用和对比分析,证明考虑移情关系能促进共识达成,且机会约束鲁棒共识模型能更好的平衡经济性和保守性。

自适应分块的改进最小费用网络流解缠算法

相位解缠是进行精确差分干涉测绘的关键步骤,在相位解缠算法中,最小费用网络流(MCF)是当前常用的算法,该算法具有精度高、限制残差点误差扩散、优先将误差限制在低相干区域的优点,但随着残差点数量的增多,其计算效率也随之降低。改进的MCF算法通过对其做分块,有效提升了算法效率,但块尺寸的选取影响最后的准确度与效率。本文提出一种自适应分块的改进MCF解缠算法,通过自适应寻优的方式选取合适的分割块,将相干性较高的点集中在同一块内,使得在准确度不受过多影响的情况下有效地提升算法效率。

基于遗传的海上风电集电系统拓扑优化

针对海上风电工程集电线路拓扑的自动优化布置,文章以集电线路的全寿命周期成本作为目标函数,海缆选型和海缆交叉规避作为主要约束条件,建立数学模型,同时基于动态边权最小生成树算法改进遗传算法的种群生成方式以扩大算法的搜索解空间,以期凭借较好的寻优能力求解集电系统拓扑优化问题,提升海上风电场的综合效益。海上风电场项目算例结果验证了方法的有效性和快速性,可为海上风电集电系统规划设计提供具有实用价值的参考。

基于非值乘时间成本的乘务排班计划优化编制方法研究

乘务排班计划是城市轨道交通运输计划的重要组成部分,其编制方案优劣直接影响企业运营安全与乘务支出。在班制规定工作时间内,非值乘时间占比越高,工作所需人力资源越多,运营支出效益越低。文章通过缩减乘务人员非值乘时间中的非必要整备时间,从时间成本角度出发,构建最小费用模型。同时设计以爬山算法作为局部搜索策略的文化基因算法,用于优化传统遗传算法对于解的早熟或不收敛导致局部最优的潜在可能。最后以上海市轨道交通某条线路作为案例研究,结果表明模型能够在满足运营需求的前提下,优化乘务人员数量,从而降低乘务支出。其研究结果可为城市轨道交通精细化管理提供理论依据和参考。

Optimization of Evidence Analysis Cost Using Arbitrary Re-Sampling Techniques for Sample Influx into Forensic Science Laboratory

This study analyzes the sample influx (samples per case file) into forensic science laboratory (FSL) and the corresponding analysis costs and uses arbitrary re-sampling plans to establish the minimum cost function. The demand for forensic analysis increased for all disciplines, especially biology/DNA between 2014 and 2015. While the average distribution of case files was about 42.5%, 40.6% and 17% for the three disciplines, the distribution of samples was rather different being 12%, 82.5% and 5.5% for samples requiring forensic biology, chemistry and toxicology analysis, respectively. Results show that most of the analysis workload was on forensic chemistry analysis. The cost of analysis for case files and the corresponding sample influx varied in the ratio of 35:6:1 and 28:12:1 for forensic chemistry, biology/DNA and toxicology for year 2014 for 2015, respectively. In the two consecutive years, the cost for forensic chemistry analysis was comparatively very high, necessitating re-sampling. The time series of sample influx in all disciplines are strongly stochastic, with higher magnitude for chemistry, biology/DNA and toxicology, in this order. The PDFs of sample influx data are highly skewed to the right, especially forensic toxicology and biology/DNA with peaks at 1 and 3 samples per case file. The arbitrary re-sampling plans were best suited to forensic chemistry case files (where re-sampling conditions apply). The locus of arbitrary number of samples to take from the submitted forensic samples was used to establish the minimum and scientifically acceptable samples by applying minimization function developed in this paper. The cost minimization function was also developed based on the average cost per sample and choice of re-sampling plans depending on the range of sample influx, from which the savings were determined and maximized. Thus, the study gives a forensic scientist a business model and scientific decision making tool on minimum number of samples to analyze focusing on savings on analysis cost.

Cost Edge-Coloring of a Cactus

Let C be a set of colors, and let ?be an integer cost assigned to a color c in C. An edge-coloring of a graph ?is assigning a color in C to each edge ?so that any two edges having end-vertex in common have different colors. The cost ?of an edge-coloring f of G is the sum of costs ?of colors ?assigned to all edges e in G. An edge-coloring f of G is optimal if ?is minimum among all edge-colorings of G. A cactus is a connected graph in which every block is either an edge or a cycle. In this paper, we give an algorithm to find an optimal edge- ??coloring of a cactus in polynomial time. In our best knowledge, this is the first polynomial-time algorithm to find an optimal edge-coloring of a cactus.

计及暂态频率稳定约束的同步惯量经济价值评估

高渗透率新能源接入系统后,保障系统具有充足的在线惯量是维持系统频率安全稳定的关键,同时建立惯性辅助服务市场是解决该问题的有效手段。因此,将同步惯性响应纳入有偿服务,搭建考虑系统最低同步惯量需求约束的定价出清模型,并提出离散变量松弛化的方法,将出清模型转化为凸优化问题。然后,基于边际成本定价法和拉格朗日对偶原理,以最低同步惯量需求约束对应的影子价格来评估其经济价值,为惯性服务定价。最后,以改进的IEEE 39节点系统和IEEE 118节点系统为例,对同步惯量影子价格的存在机理、数值影响因素以及同步机组收益进行分析讨论。结果表明,含高比例新能源系统具有建设惯性辅助服务市场的必要性和迫切性。所提方法和仿真结论为惯性服务市场化提供了参考性意见。