Investigations of Distribution System Planning of Loop Configurations Using a Genetic Algorithm

The distribution system planning is performed with a loop configuration constraint from scratch.With Evolutionary Algorithm,a sample distribution network is designed with a loop configuration,in which the system is operated as radial configuration.It firstly introduces the mathematical model for distribution network planning,then the application of Evolutionary Algorithm for the planning of distribution network.By using the theory mentioned above, Visual C++ is applied to develop the distribution network optimization software.Finally with the optimization process of 17 nodes system being showed,the presented algorithm's utility and validity is verified.     

Site tools distribution method for machining job shop and its implementation

Aiming at site management problems of machining job shop, a site tools management method based on dynamic distribution for machining job shop is proposed. According to the method, the site dynamic distribution plan of machining tools is generated. A site tools distribution management information system is developed. The function and information models of the system are presented. With the system, dynamic distribution and recycling of machining tools and materials is realized. As a result, the inventory of machining tools is reduced, and the productivity is improved. The system has been applied in a machining job shop with satisfied result.     

混凝土灌注桩中混含硫酸盐的时变分布规律

硫酸盐环境下,为模拟混凝土灌注桩施工时混入的硫酸盐在桩中的时变分布行为,基于Fick第二定律并结合初始条件与边界条件,应用分离变量法,建立硫酸盐在桩中的时变分布模型。通过算例将本文解与传统解进行比较,并进一步探讨了硫酸盐扩散分布的影响因素和影响规律。结果表明,传统解用于分析混凝土灌注桩桩中硫酸盐扩散有局限性,而本文解相对于传统解具有一定的优势。混凝土灌注桩半径越小,应用传统解分析灌注桩中硫酸盐时变分布误差较大,同时,误差随时间增大。硫酸盐在混凝土灌注桩中的时变分布呈沙漏形,沿半径方向x=0处和桩表面处扩散行为明显,在x=0处附近区域,初始第一年扩散速率较快,在后续的50 a内扩散速率显著减小,但每10 a的平均速率基本相同。扩散系数和初始浓度梯度对硫酸盐在混凝土灌注桩中的时变分布影响较大。     

蓟马对紫花苜蓿危害的空间分布特征

昆虫空间分布格局是其种群的一种客观属性,对于同一种群,其格局类型是固有的.蓟马为一种体型较小的昆虫,取食时移动性强,易逃逸,所以用危害特征的空间分布来代替其本身的空间分布更具有稳定性和实用性.采用不同尺度研究探讨蓟马对紫花苜蓿危害的空间分布特征.研究表明在现蕾期危害空间分布为聚集分布,危害斑块尺度是40 cm×30 cm～50 cm×30 cm的椭圆型,长轴方向是东西向.因此在这一物候期选择抗蓟马材料时,取样应该按南北方向,尺度距离大于40～50 cm,更具有代表性,在开花期危害空间分布为均匀分布,但是取样尺度也应大于40～50 cm,更具有代表性,而且在开花期取样要比现蕾期取样更好一些,会减少取样误差.     

The effect of skewness on selection in a plant breeding program

Summary The distribution of many plant characters is skewed. The standard formula for the expected gain from selection is based on the assumption that the character value is the sum of two independent normal variables, one genetic and the other environmental. If the genetic variable is normal, but the environmental variable has a positively skewed distribution, then upwards selection will give a lower gain than that expected if both distributions are normal. If the distribution of the environmental variable is negatively skewed, then upwards selection will give a larger than expected gain. Of course, with downwards selection, the results will be reversed. This leads to asymmetry of response if both upwards and downwards selection are used. In cases where unexpected responses to selection are obtained and normality of the character distribution has been assumed, skewness of the data should be checked as possible cause.     

Simplified Method for Calculation of Current Distribution on Grounding Electrodes

A new method is presented to calculate the non-uniform of current distribution on grounding electrode. Based on the equivalence of low frequency current field and static electric field, the electrode is simplified to he a line charge model with limited length. The charge distribution on the model is calculated by solving equilibrant equations, and the current distribution along the axis of electrode was got. The current density at the end of electrode can he several times of that in the middle, the non-uniformity get worse with the increasing of electrode length and numbers. This is what lead to several problems on grounding systems such as inefficiency, the partial overheat and the severe corrosion of electrode.     

延河流域耕层土壤养分空间变异及与地形因子的相关性研究

了解耕层土壤养分空间变异规律及其与地形因子的相关关系,以期为土壤养分有效利用和农业管理提供理论依据。以延河流域为研究对象,利用地统计学与GIS相关方法,研究土壤空间分布及变异规律,并基于DEM数据提取相关地形因子,分析流域尺度下地形因子对土壤养分空间分布的影响。研究区耕层全氮和有机质处于较低水平,速效钾和有效磷处于中等水平,pH呈弱碱性,空间变异大小依次为速效钾>有效磷>全氮>有机质>pH。构建的土壤养分指标半方差函数决定系数均大于0.6;土壤pH空间分布最为破碎;土壤速效钾和pH块金系数小于25%,主要为结构性因素影响;土壤全氮、有效磷、有机质具有中等水平的块金效应,受结构性因素和随机因素共同作用;其中有效磷块金系数最大,人类活动对其空间变异影响更大。全氮与有机质分布规律由西北向东南先递增后递减,速效钾呈现由西北向东南波浪形递减的分布格局,有效磷整体分布趋势表现为由中游向上下游降低,土壤pH沿某一方向变化的趋势不强。土壤养分空间变异情况与地形因子的相关关系相一致。在地势较低且平坦的区域内,更有利于农业生产,土壤养分较为充足;在高海拔、地形起伏较大区域养分含量相对较低。     

基于Weibull模型的细粒尾矿粒径分布

尾矿细粒化是矿业发展趋势,细粒尾矿的粒径分布对尾矿宏观力学特性及坝体稳定性具有重要影响。采用筛分法和沉降法,对82个尾矿试样进行了颗分试验,建立了细粒尾矿粒径分布的Weibull函数模型。试验结果表明:细粒尾矿粒径呈"细多粗少"的分布规律,这种规律服从Weibull分布,可以用Weibull分布对粒径分布进行描述和外推预测;传统分形模型中假设每级粒度的破碎率为常数与实际情况不符,Weibull分布可以看作对分形模型误差的一种修正;在破碎过程中,粒径的概率密度分布会出现峰值,这个峰值不断向粒径小的方向偏移,最终形成"细多粗少"的分布特点。研究结果有助于磨矿工艺的改进,并可以为土工试验做出科学的级配方案提供参考。     

Fast Algorithm of Loads Equalization for Distribution Networks Based on Partition-hierarchical Model

Along with enlargement of scope of distribution, algorithms of reconfiguration for distribution networks become difficult to satisfy real-time require of engineering applications. This paper provides a new algorithm a fast algorithm based on partition-hierarchical model. It is found that partition of loads is relation of the smallest load of vertex that is bigger than average and the biggest load of vertex that is smaller than average. The method reduces the numbers of switches combination by searching smallest load of vertex that is bigger than average and the biggest load of vertex that is smaller than average and realize a fast algorithm of the loads global optimal equalization for distribution networks by transferring the loads. Results of test show that the method presented is applicable and efficient.     

Application of Spatial Interpolation in GIS

Spatial interpolation includes point interpolation and areal interpolation. The point interpolation is mainly used to deal with natural geography data and the areal interpolation is usually used to solve the interpolation problem of social economic statistic data. However, social economic statistic data are often collected by areas, which cannot represent their real spatial distribution. A spatial distribution model of social economic statistic data is to be established to conform to their real spatial distribution. Using the areal weighting interpolation and inverse distance weighted averaging, a spatial distribution model of GDP is established in this paper.     

Effect of Filter on Exit-age Distribution Function

Exit-age experiments have been carried out on the same reactor with and without filter. The effects of filter on exit-age distribution function have been studied. The specific formula of exit-age distribution function for the reactor with filter is: E(t)=f_1E_1(t)+(1-f_1)E_2(t)+E_3(t). In this formula,E_3(t) is a factor considering the filter effect on reactor.     

Finite Element Simulate Analysis of Small Span-to Depth Ratio Coupling Beams with Special Reiforcement

Test investigations show that the reinforcement scheme with adding diagonal and rhombic bars to traditional reinforcement in the foundation is an ideal way, for the seismic performance of small span-to depth ratio coupling beams with this scheme is better than that of traditional reinforcement. Because the regions in the small aspect ratio coupling beam belong to D-regions, in which the Bernoulli hypothesis of plane strain distribution is invalid, the traditional bending theory can not be used. This paper simulates the coupling beam through non-linear finite element analysis program, and contrasts the analysis result of the bar's stress distribution with test result. The contrast results confirm that it is a valid way to analyse the bar's stress distribution in this coupling beam through non-linear finite element analysis program.     

Sky luminance distribution model by ant colony systems

The sky luminance distribution model is developed by information analysis methods with ant colony system. A new arithmetic is given to solve complex optimization heuristic algorithm. The coefficient values of sky luminance distribution function are obtained by optimization analysis with ant colony system and on which a set of practical software is developed. It can provide an intuitive and easy calculation. The model has higher precision, which can provide valuable results on high precision and standard daylighting design.     

Recognition and prediction of fracture by using antcolony algorithm analysis in carbonate reservoir

A fracture-developed carbonate oil field in the east has a complicate oil and gas distribution in facture network at late development stage, which leads to multiplicity of favorable reservoir estimation. In view of problems above, ant colony algorithm is adapted to recognition and predict facture in this field. The ant parameters are optimized on the basis of core and image log data, and the spatial distribution feature of fracture is described, as a reticulate structure with three dominant clusters of fracture (NW, NNE & NE). Drilling leakage, production data and image log are then used for reliability analysis of fracture predict, which presents that ant colony algorithm is a practicable methodology to recognition fracture and provides a support for remaining oil distribution analysis. As a booming bionic algorithm, ant colony algorithm has great potential for quantitative fracture predict with seismic materials.     

水稻籽粒蛋白质含量的空间分布特征

为解析2种穗型水稻籽粒蛋白质含量的空间分布特征。以弯曲穗型‘两优培九’和直立穗型‘武香粳14号’为材料,研究了在2个施氮水平下,籽粒蛋白质含量在穗上不同部位和不同粒位间的差异及其分布特征。结果表明:穗内各籽粒在不同蛋白质含量区间的频数变化趋势呈正态分布;在稻穗的同一部位,2个供试品种一次枝梗上的籽粒蛋白质含量高于二次枝梗;一次枝梗上的籽粒蛋白质含量以第2粒位籽粒较低,第1粒位的籽粒较高;二次枝梗上第1粒位籽粒的蛋白质含量较高。蛋白质含量在穗上不同部位及一、二次枝梗上的分布因品种和施氮量的不同而异,施氮量在110~220 kg/hm2范围内,增施氮肥可以减少穗内粒间的籽粒蛋白质含量差异。     

棉花冠层不同尺度光能空间分布特征研究

【目的】棉花冠层光能空间分布是光能利用率高低的直接影响因素之一。为科学量化光能在棉花冠层的空间分布,本研究旨在分析冠层内光合有效辐射(Photosynthetically active radiation,PAR)各分量的空间变化特征。【方法】用空间统计学方法分析了冠层不同空间点、线、面位置PAR的分布特征。【结果】盛花期棉花行间冠层PAR截获率整体变化呈"V"形,即棉行间PAR截获率低于棉行附近位置;高密度的群体冠层中下部PAR截获率纵向变化速率较缓,同时在距地面60 cm处PAR截获率横向变化幅度也较小;不同冠层区域的PAR截获率与密度呈正相关关系,且随播种后时间均呈现先增后减的变化趋势。【结论】适当增大种植密度可以提高群体PAR截获率。运用空间统计学原理精确定位定量分析冠层内PAR的分布,对合理配置棉花种植模式、研究群体株型结构、培育高光效品种具有指导意义。     

遗传算法在盐分胁迫下冬小麦根系分布预报中的应用

盐分存在条件下根系在土壤剖面中的分布会随众多的因素产生变化,由常规的拟合方法得到的根系分布与实际值会存在较大的误差。在此,基于遗传算法建立了一种获得盐分胁迫下冬小麦根系分布参数的模型,经过检验,模型整体预报效果较好,可以通过间接的、相对容易的途径获得相对准确的根系参数,可以满足实际应用的需求。     

Dynamic Arrangement of Corporate Property Rights and the Equilibrium Analysis of Corporate Surplus Allocation

According to Coase and Alchian's definition ,the corporation is a contract consisting of variety essential factors.The essential factors of the firm can be separated into human capital and non-human capical. The owner of the factors will be confronted with rearrangement of the property rights when forming a contract. At the same time, the firm is a special contract which different from other short-term contract. Therefore, its property rights arrangement is dynamic and its surplus distribution is dynamic ,too. By analyzing the arrangement process of the property rights and surplus, the paper draws a conclusion about distribution equilibrium.     

中国自然科学论文作者的简要统计分析

按国际文献计量学研究的通行做法,论文的归属按第一作者所在的地区和单位确定。通过对作者群的学科分布,机构分布,地区分布,高产、高影响作者群分布等统计,分析我国科研队伍发表论文现状。目前,我国作者群的学科分布不均匀,高产作者群,特别是国际论文的高产作者群主要分布在化学、物理、生物和数学等学科。作者群的地区分布不均匀,特别是地域广大、跨13个省（市）的大西北论文作者数,无论是国际或国内论文的比例都不足16%。高产作者群的4/5分布在我国高等学校。     

崇阳杉木无性系种子园花粉散发与空间分布特性研究

本文以湖北崇阳杉木无性系种子实地调查和定点观测资料为依据，对杉木花粉的散发和花粉空间分布进行了研究。结果表明，杉木花粉的散发出现季节及昼夜节律。杉木花粉的垂直空间分布为集群分布，种子园内花粉呈均匀分布型，园外则随距离种子园的远近呈扩散分布型，种子园的隔离距离为600－1000米。并据此制订了杉木种子园人工授粉操作规范。