Theories and Methods of Non-optimum Analysis on Systems

The theory of non optimum analysis on systems were discussed in detail. It was pointed out that the main problem of exploring an indefinite systems’ optimum lies in the lack of non optimum analysis on the system. The syndrome and empirical analysis based on the non optimum category of the system were established. At the same time, the non optimum measurement of the system along with non optimum tracing and self organization of the systems was also put forward.

OPTIMUM DESIGN BASED ON RELIABILITY IN STOCHASTIC STRUCTURE SYSTEMS

The optimum design method based on the reliability is presented to the stochastic structure systems （i. e., the sectional area, length, elastic module and strength of the structural member are random variables ） under the random loads. The sensitivity expression of system reliability index and the safety margins were presented in the stochastic structure systems. The optimum vector method was given. First, the expressions of the reliability index of the safety margins with the improved first-order second-moment and the stochastic finite element method were deduced, and then the expressions of the systemic failure probability by probabilistic network evaluation technique（PNET） method were obtained. After derivation calculus ,the expressions of the sensitivity analysis for the system reliability were obtained. Moreover, the optimum design with the optimum vector algorithm was undertaken. In the optimum iterative procedure, the gradient step and the optimum vector step were adopted to calculate. At the last, a numerical example was provided to illustrate that the method is efficient in the calculation, stably converges and fits the application in engineering.

Optimum Selecting Method of CNC System′s Accessories

The object of this dissertation is to select the best-quality product in CNC system′s accessories.It applies the relative theories of Fuzzy Mathematics to solve the issue,and it sets up the effective optimum selecting theory model.Moreover,it presents a kind of applicable way,which selects the best-quality product,and proves its availability by the living case.

ATIS与收费策略下多用户随机均衡的效率损失

考虑ATIS作用的交通网络,用户具有交通信息接受程度的异质性;进一步,考虑实施道路收费策略情形下,用户具有时间价值的异质性;基于这两类异质性,研究了ATIS下异质性交通网络的效率损失问题。用户对ATIS系统的响应程度,亦即ATIS信息遵从率,是影响ATIS系统运行效率的关键因素。因此,通过ATIS信息遵从率参数的引入,将用户分为不同类型。假设用户均按照随机方式进行择路,建立了基于时间准则与基于费用准则的多用户Logit-随机均衡变分不等式。当系统总出行成本包含收费时,建立了多用户双准则系统最优模型,界定了多用户Logit-随机均衡相对于多用户系统最优的效率损失,推导出效率损失上界;进一步分析了当路段阻抗函数为多项式情形时,引入了自由流出行时间参数,给出了双准则下效率损失上界的解析式,分析了效率损失上界与各参数之间的关系。研究结论表明,双准则下效率损失上界为ATIS信息遵从率的减函数;此外,效率损失上界与路段阻抗函数、用户时间价值及其对路网的熟悉程度、路网本身复杂程度等因素有关。最后,通过算例验证了结论的有效性。

双城系统的聚集外部性、拥堵外部性和最优收费

聚集外部性有利于提高双城系统的经济发展,但同时也会产生城际通勤拥堵外部性,为缓解城际通勤交通拥堵,可以利用最优收费调节交通供需关系。本文研究了城际通勤最优收费水平随交通拥堵外部性和聚集外部性的变化规律,建立双城系统的空间均衡模型和社会最优模型,分析居民的职住分布,得到城际通勤最优收费水平。结果表明,因为聚集外部性的存在,城际通勤最优收费水平可能大大低于交通拥堵外部性成本;当聚集外部性固定时,城际通勤最优收费水平随交通拥堵外部性的增大而增大;当交通拥堵外部性固定时,随着聚集外部性的增大,城际通勤最优收费水平先增大后减少;当聚集外部性和交通拥堵外部性同时变化时,随着聚集外部性的增大,交通拥堵外部性的减少,城际通勤最优收费小于零,此时,城际通勤时可以得到补贴。

铁路沿线光伏供电系统优化设计方法研究

离网式太阳能光伏系统是解决铁路沿线设施电气化运维用电需求的必要途径。《光伏发电站设计规范》(GB 50797―2012)等相关规范的规定或建议一般以年最大发电量为目标,主要面向均衡性负载和并网发电,直接用于铁路沿线时存在盲目性。针对铁路沿线特殊的用电场景与负载需求,提出了铁路沿线离网式光储系统的组件匹配原则及设计流程,构建了面向任意时间跨度的光伏供电系统优化设计模型,并基于Python语言编制了计算程序。模型包括太阳辐照量模型、光伏阵列倾角及间距模型、发电量模型、光伏组件数量及串并联方案模型、蓄电池模型、控制器模型及逆变器模型等。计算程序实现了光伏阵列最优倾角的自动搜索,可以针对不同地理位置、用电量和用电时间跨度(月、季节、年等)的负载需求,并考虑气象条件、组件性能衰减等因素的影响,完成光储系统的设计选型和安装方案优化。在准池铁路的实际应用表明,一年中光伏阵列在各月对应的最优倾角存在明显差异,6月达到最小值16°,12月达到峰值69°。以全年、夏半年、冬半年的最大总辐照量为目标时,最优倾角分别为46°、25°、61°。对于案例中冬季型负载,采用基于本文模型的设计方案相比规范建议方案节省投资8.8%。研究成果可为铁路沿线光伏供电系统应用提供一种便捷的设计方案。

贫困地区分布式光伏电站并网发电系统应用研究

为充分利用贫困地区空置屋顶及土地资源优势,发展光伏发电产业,降低碳排放,保护环境并改善居民经济状况,本文以某贫困地区安装总容量约为650kWp的分布式光伏电站设计为案例,根据当地太阳能资源和气候条件等情况,选取合适的光伏电池组件和逆变器型号,通过PVsyst软件模拟仿真计算得出光伏阵列最佳安装倾角,由此计算确定光伏阵列的布置间距,最后推算出本案例25年内的发电量,并对环境效益进行评估,为光伏扶贫工作提供借鉴和经验。

并联水泵控制策略优化分析

以上海某汽车工厂冷站的二级泵系统为研究对象,探讨优化水泵系统运行以提高效率的方法。从能源管理系统导出历史运行数据,建立水泵实际性能模型;利用Matlab软件创建数学模型遍历工况求解,进行最优运行台数分区;根据现场实际情况制定优化运行策略并部署运行。结果表明,水泵节能率达到7%,对提升水泵效率具有指导意义,可以在不进行硬件改造的前提下,降低运行成本。

基于RLoMAG+EAS的同构集群装备体系作战效能评估方法

装备体系是作战体系在装备视角的反映,研究装备体系作战效能评估问题,对装备体系优化、建设发展具有重要现实意义。集群装备作战体系对抗,具有大规模、高动态、强对抗特点,传统方法难以对其作战效能直接进行评估,针对单一任务同构集群装备体系(如无人机侦察蜂群、地面无人平台火力突击集群等),从多智能体博弈理论的视角,将装备体系对抗过程看作为多智能体系统马尔可夫博弈过程,提出一种基于多智能体博弈强化学习(reinforcement learning of multiagent game,RLoMAG)的装备体系作战效能评估方法。分析了评估方法原理,建立了装备体系对抗模型。给出了装备体系作战效能评估方法框架,包括智能体建模、博弈算法设计、装备体系作战效能指标设计,开展探索性体系对抗仿真,求解装备体系博弈最优策略,分析最优策略下的装备体系作战效能指标等步骤。以基地防御作战场景为背景,给出了无人机蜂群装备体系作战效能评估方法应用示例,验证了方法的有效性。

Application of Bis(2-Ethylhexyl) Sulfosuccinate(AOT) /Isooctane Reverse Micellar System in Extraction of Sesame Residue Proteins

[ Objective] To investigate the factors affecting sesame residue protein extraction and find the optimum extraction conditions, [Method ] Sesame residue proteins were extracted with bis（2-ethylhexyl）sulfosuocinate （AOT）/isooctane reverse micellar system. Orthogonal test was used to screen the optimum combination of four factors including sesame residue concentration, pre-extraction pH value, potassium chloride concentration and reverse extraction time. The yield of extracted sesame residue proteins was the indicator to evaluate the efficiency of process. E Result1 The optimum extraction conditions are as follows： sesame residue concentration： 0.06 g/ml; pre-extraction pH value, 3.0; potassium chloride concentration, 1.5 mol/L; and reverse extraction time, 20 min. In the optimum extraction conditions, the extraction rate was up to 86%. [ Coaclusion] Extraction of sesame residue proteins can be well performed with AOT/isooctane reverse micellar system.

基于LabVIEW的最佳传输系统设计

数字传输分为基带传输和带通传输两大类。最佳传输系统定义为消除了码间干扰且抗噪性能最理想的系统,是数字通信原理教学中的重点、难点。基于LabVIEW软件仿真设计最佳基带传输系统和最佳带通传输系统,最佳基带传输系统中的脉冲成形滤波器和匹配滤波器通过公式节点编写实现;最佳带通传输系统中的脉冲成形滤波器和匹配滤波器调用LabVIEW自带的模块实现。实验结果表明,设计并实现的最佳基带传输系统和最佳带通传输系统性能良好,抗噪声能力强。基于LabVIEW的最佳传输系统设计不仅可以提高学生的学习兴趣,还有助于培养学生的工程实践能力和创新能力。

A PRIMARY APPROACH TO CHINESE STRATEGIC INDUSTRIAL SYSTEM

Generally speaking, strategic industry sectors of a country or an areahave such characteristics as relatively higher growth rate, higher la[)'>ur productivity,higher rate of employment, higher technological level, higher rate of technologicalimprovement, more obvious competitive advantages, stronger power and biggerscale, higher demand flexibility and better economic benefit compared with that ofother industrial sectors. Theoretically, each industry can become a strategic industrydepending on strategic task, goal of a given economic development stage and nationalor regional conditions. So, establishing strategic industrial system, as output of thedevelopment of social labour division, is of great significance in both constructing national or regional industrial structure and making out national regional industrial policy. In this paper, the authors made a detailed study on China's strategic industrialsystem by using Weaver--Thomas Model.

人工和自动混合驾驶环境下的最优道路拥堵收费模型

为了得到自动驾驶汽车(CAV)与人工驾驶汽车(HDV)并存条件下最优道路收费方案,针对CAV在道路上的通行能力,特别是对道路容量产生的影响进行量化分析,获得道路容量与HDV流量和CAV流量之间的非线性关系。然后,对传统的美国公路局路阻函数进行改进,并基于改进后的路阻函数,建立系统最优(systemoptimal,SO)流量分配模型,对不同CAV占比条件下和不同HDV与CAV安全车距比值条件下的交通流进行系统最优分配。采用Frank-Wolfe算法,对SO模型进行求解,并考虑因HDV而产生的额外道路出行成本对不同条件下系统最优分配结果的差异性进行比较。基于最优收费理论,针对不同规模道路网制定相应的收费方案。最后,将模型与算法应用到Nguyen-Dupuis交通网络中。结果表明,在HDV与CAV并存条件下,以系统最优分配结果下的边际成本进行收费是道路交通系统最优拥堵收费方案,可作为HDV与CAV并存条件下道路收费方案设计的依据。

数控机床在机测量系统最佳测量区确定方法

为研究面向不同测量对象且具有普适性的数控机床在机测量系统最佳测量区确定方法,选择球作为测量对象,分析了在机测量系统的工作原理及误差来源,利用BAS-BP神经网络建立了单项几何误差白化模型,同时建立了测量系统综合误差模型和球测量误差模型。研究了用于确定最佳测量区搜索寻优的差分优化布谷鸟(DE-CS)算法,进行了不同算法搜索性能对比,确定了算法最优性能参数。搭建了确定球最佳测量区的实验装置,进行了相应实验,对比了利用算法确定和实际测量得到的最佳测量位置的一致性。实验结果表明,利用上述方法搜索计算确定的面向球最佳测量区位置与实验测量确定的最佳测量区位置一致,最佳测量区为:430.783mm≤X≤439.783mm,-145.133mm≤Y≤-136.133mm和-268mm≤Z≤-258mm,实测最大误差最小值为3.1μm,算法求解的误差也为整个测量空间的最小值0.7107μm,且可用于面向点、面等其他测量对象的最佳测量区确定,具有普适性,可用于确定在机测量系统的最佳测量区。

Theoretical Comparative Energy Efficiency Analysis of Dual Axis Solar Tracking Systems

This paper developed a theoretical model substantially based on the principle that only the normal component of solar radiation is actually converted into electrical energy. This theoretical model helped to predict minimum and maximum daily energy gain (compared to static PV system tilted with certain angle) when using dual axis PV solar tracking systems, at any given location on earth without prior experimental data. Based on equations derived from model, minimum and maximum energy gain is computed and summarized in tables of minimum and maximum. Furthermore, the model equations could be used to set up future experimental studies related to the matter.

基于视觉修正的改进最大最小蚂蚁系统求解TSP

蚁群算法的研究与发展为解决优化问题提供了良好的方案,但是依然存在收敛速度慢和容易陷入局部最优的问题。为此,提出一种基于视觉修正的VC-MMAS算法。该算法以启发式信息为依据初始化信息素浓度,从而加速初期的算法收敛速度;引入“天文蚁”对历史最优路径进行检查和修正,同时使用“双优”策略更新信息素,帮助算法跳出局部最优。在旅行商问题(TSP)上的实验对比表明,该算法与其他算法相比具有更好的全局寻优能力和稳定性。

Optimum Designing of Gas Distribution Networks of Ilam Province by Using GIS Network and Spatial Analysis

Undoubtedly, pipeline transport is considered as significant economical artery of country and national valuable resources, so it is necessary to use latest technologies, major standards and instructions and the best human resources in designing, operation and supervision in construction and also protection of it. Also, all authorities and involved of construction and operation of gas industries installation should observe safety criteria, health and environment and aware of them ever. In fact, in designing of these programs, in addition to technical and economical points, environmental characteristics should be considered in order to their construction has minimum damage to environment. On the other hand, common and traditional approaches of pipeline routing are based on using costly and time-consuming methods. In these methods, it is not easily to use all effective parameters in determining optimum way. According to capability of analysis of network spatial information systems in incorporation of spatial data, for using all effective parameters in routing, this environment is used, therefore weighted overlay analysis (Boleyn, index and fuzzy) and shortest path are modeled for finding optimum path of pipeline in GIS environment.

双馈风力发电机功率控制方式的改进方案及验证

为了解决双馈风力发电机变桨电机容易故障失效的工程实践问题,提出了一种双馈风力发电机功率控制方式的改进方案。基于双馈风力发电机的数学模型,分析最大功率追踪系统的搭建方法。采用低转速时使用最佳叶尖速比法,高转速时使用最佳功率控制方案代替常用的最佳叶尖速比法转恒速控制。对两种方案创建MATLAB仿真,分析了最佳叶尖速比法和最佳功率控制方案的优缺点。仿真表明该方案较传统方案更有优势,可以减少变桨次数,明显提高变桨电机的工作寿命,与实际的解决方案相符。

基于串级离散极值搜索框架的光伏MPPT控制研究

光伏系统具有非线性、时变特征,且局部遮阴条件下功率输出存在多峰现象。为保持光伏系统始终输出最大功率,同时优化控制过程的瞬态响应,提出了一种串级离散极值搜索框架,其中包括T周期采样器、零阶保持器、收敛判别器、前级区间搜索算法、中级当前最优搜索算法和后级全局最优搜索算法。进一步改进了松鼠搜索算法,并实现了中级当前最优搜索。对光伏发电系统开展了数值仿真实验。与国内外最新文献中提出的方法相比,所提出的方法收敛速度最快,振荡次数最少,这表明所提出的方法极大提升了最大功率点跟踪控制过程的瞬态性能。

兼顾产量和氮肥利用效率的间作体系小麦最适施氮量分析

探究小麦蚕豆间作体系下的小麦最适氮肥施用量,建立作物产量和氮肥利用效率协同提高的间作体系氮肥管理策略。通过2年的田间定位试验,在N 0、90、180、270 kg/hm24个小麦施氮水平下,研究了小麦蚕豆间作体系的产量效应、氮肥利用效率、兼顾产量与氮肥利用效率的小麦最适施氮量和推荐阈值,探讨了间作提高小麦产量和氮肥利用效率的关键土壤因子效应。结果表明,在4个施氮水平下,与单作小麦相比,间作小麦产量平均增加22.12%,产量可持续性指数平均增加3.68%,土地当量比平均为1.13,氮肥表观利用率平均增加18.44%,氮肥农学利用率平均增加9.64%,氮肥偏生产力平均增加21.14%。回归分析结果表明,小麦间作最高产量施氮量较单作平均减少3.28%,增产18.76%。以小麦相对产量的85%~90%作为氮肥施用量的推荐范围,小麦单作氮肥推荐阈值为101~128 kg/hm2,间作小麦氮肥推荐阈值为90~117 kg/hm2,小麦间作较单作施氮量减少9.40%~12.22%,小麦产量增加18.20%。综合小麦产量和氮肥利用效率的关系,单作小麦最适施氮量为133 kg/hm2,间作小麦最适施氮量为106 kg/hm2时可兼顾提高小麦产量和氮肥利用效率,保证小麦增产及氮肥减施增效。结构方程分析表明小麦间作中硝态氮是提高氮肥利用效率的关键土壤因子。