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1.
Based on the algorithms proposed before,a model and new heuristic algorithmfor solving the load balance in a parallel processing system (cell) is put forward by authors in thispeper. The optimal goal of the propsed model benefits the minimum of the load of equipment withlargest load and the difference between and two equipments in the system. The complexity ofalogrithm is not higher than O(n2). The computational experiments show that it is a practical algorithmof engineering.  相似文献   

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3.
In the period of the city space expanding with the high speed, the theories system used to explain the city space is not perfect in our country. It is lack to expand this mechanism, among them research ecosystem' s main factors to particularly should be enhanced, especially the ecological factor. With rational analysis, the paper puts forward the viewpoint that the urban space is in ecological changing period, and considers that the power affecting the urban space expand involves motivity and resistance. Building the corresponding ecological model helps to cognize the city development roundly with ecological model constructed. A few possible ways is put forward which can be used in planning innovation, and have vivid leading function to the frondose city planning method.  相似文献   

4.
This paper analyses the cause of very slow learning rate during the time of ap-proaching the minim um poi nt in con vertional BP algorithm, by introducing weight factor into themodification of the connection weight,an improved leavning algorithm for BP model is presented,itcan sign ificantly in crease the learning rate and improve con vergent behaviour.As an illustrative ap-plication example,the n umeriCal resu It of the medium-term load forecasting is given.  相似文献   

5.
The characteristic and shortcoming of the common algorithm of constrained two-dimensional Non-Guillotine Optimal cutting stock problem are analysed. Base of designing a model of cutting stock problem, a new heuristic algorithm applying column generation algorithm and simulated annealing algorithm is shown. The presentation of the processing steps and the data structure prove that the algorithm has fast computing speed and excellent result. An examples by the algorithm are given, which indicates the algorithm is new and effective.  相似文献   

6.
《保鲜与加工》1998,(2):47-51
Parallel machining system is a kind of typical production environment.Its scheduling algorithm has Np_Completeness if E/T is optimal criterion.In this paper,an advanced heuristic algorithm is developed.The new algorithm's property lies in simplified computation,low complexity and easy programming.It has been shown that the heuristicalgorithm can be used in engineering.  相似文献   

7.
层次聚类分析法在烟草平衡施肥中的应用   总被引:1,自引:1,他引:1  
平衡施肥要求根据不同土壤中养分含量的差异和不同作物的生理需要,合理地供应和调节作物生长发育所必需的各种营养元素。由于不同的土壤中养分含量差异很多,根据平衡施肥原理所产生的施肥方案也会很多,而过多的施肥方案在生产中不仅难以制定,而且也无法实施。因此在平衡施肥的生产应用中急需有一种科学而又简便的方法来指导施肥方案的制定。打破传统中按行政区划制定施肥方案的做法,对南阳烟区171个土样的养分含量进行层次聚类分析,结果表明,171个土样可以分为有显著差异的15类,根据每类土样养分含量的平均数和标准差,把其与烟叶生长土壤养分临界值进行比较,制定了相应的施肥方案,并对其中5个大的类别进行了验证试验,获得了显著的增产增值效果,证明运用层次聚类分析结果结合平衡施肥原理制定的施肥方案切实可行。  相似文献   

8.
According to the theory of truss-arch model, the shear mechanism of reinforced concrete beam was analyzed, and formula of shear bearing capacity was proposed. In this formula, softening effect of concrete and the arch function were taken into account, and the coefficients in the formula were amended with experimental data. When the performance difference between the structural material and the original material is huge, the code formula of shear bearing capacity calculation is inapplicable. After the computation, the ratio of the results calculated by truss-arch model theory formula and the results calculated by the current code formula was close to 1, and the standard deviation coefficient and coefficient of variation were smaller than those of standard formula results, and the results calculated by truss-arch model formula were in good agreement with the experimental results. The collected experimental data was calculated with the shear capacity formula in ACI318-08, and the calculation results showed that United States building code was more conservative than the standard of China. The results indicate that the shear bearing capacity formula based on truss-arch model can be used for computation of shear bearing capacity of reinforced concrete beams.  相似文献   

9.
湖北省水资源供需平衡及其承载力   总被引:3,自引:2,他引:1  
以湖北省为研究区域,运用水资源负载指数和水资源供需平衡模型,采用数理统计方法,定量计算和分析了湖北省近年来的水资源供需平衡态势以及湖北省市域尺度的水资源开发潜力;在水土平衡分析、水资源供需状况评价与水资源开发潜力评价的基础上,从资源平衡关系入手,采用水资源承载指数等指标,对2000—2012年省域与市域2个层面的水资源平衡状况进行了定量研究。结果表明:湖北省人均水资源量居全国平均水平。湖北省属于水资源利用程度较高、开发利用条件较好、水资源开发潜力较大的省区。湖北省水资源承载力有限,随着未来人口的增加以及工农业的快速发展,在现有的水资源量基础上,水资源短缺将会成为湖北省中东部城市的发展瓶颈。  相似文献   

10.
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.  相似文献   

11.
A approximate algorithm is presented by which satisfactory results of two dimensional optimal layout belonged to NP complete problems can be obtained efficiently and rapidly. The algorithm integrated with widespread of computer network has been applied to the distributed cutting stock system Adopting Heuristic search and Knapsack algorithm, the algorithm makes each layout optimal locally and obtained the approximate optimal solution. It is compared with other two approximate algorithms and pointed out their shortcomings. In the end of the article a layout example was presented.  相似文献   

12.
土壤有效含水量的经验估算模型——以黑土为例   总被引:1,自引:0,他引:1  
土壤有效含水量(AWC)是评价土壤生产力的重要指标,在农业生产实践中具有重要意义,但不同土壤类型的AWC值在当前的土壤数据库中不可获得。笔者以高生产力土壤黑土为例,通过测定不同地形部位黑土的有效含水量,分析了有效含水量的空间分布特征,建立利用土壤理化性质估算黑土有效含水量的经验模型。结果表明:(1)研究区黑土AWC(体积)变化在10.62%~30.98%间,平均20.06%,坡中位置土壤剖面的AWC值显著低于其余剖面;(2)黑土AWC与土壤砂粒含量有负相关性,与土壤容重、土壤粉(砂)粒含量、黏粒含量以及土壤有机质含量间有正相关性,其中与土壤容重的相关性最为显著;(3)基于统计方法建立了利用常规土壤理化性质计算AWC的线性回归式和非线性回归式,对这2个回归式的检验结果表明,利用土壤理化性质估算的AWC与实测结果无显著差异。经验证,本研究构建的经验模型可用于黑土AWC值的估算,从而为其他土壤类型AWC值的研究提供了方法参考。  相似文献   

13.
In the process of oil drilling, drilling string and rock bit are main drilling tools. The fact of their failure would cause serious accidents. To solve this problem, the vibration law of string should be found. The longitudinal vibration model, torsional model and lateral vibration model are founded simultaneity. Many methods are used to build up this model, including finite element technique, numerical technique and computer simulation. The dynamic model reveals the dynamic action of string, it is instructive to design new rock bit and study drilling mechanics.  相似文献   

14.
Based on some theories,and to analyze transformers and many different models to compare, a new kind of transient mathematical model on transformers is presented. In the model, the saturation of magnetic circuit and core losses are considered and the effects of nonlinearity of main magnetic circuit for voltage and current of transformers are analyzed. Then the applications range and the direction to improve of the model are referred to through comparing the model with other models. And the feasibility and accuracy of the model are verified through comparing the results of simulation with the results of experiments.  相似文献   

15.
闽东南耕地土壤硫素平衡及有效硫丰缺状况研究   总被引:2,自引:1,他引:2  
通过田间试验、土样和雨水、灌溉水采集测定,以及大气硫沉降和土壤硫淋溶流失有关数据收集,研究了闽东南耕地土壤硫素平衡与土壤有效硫丰缺状况。结果表明,早稻-晚稻轮作制和花生-甘薯轮作制每年分别需要91.86,128.67 kg/hm2硫素来满足生长需求,考虑到土壤硫的淋溶和流失以及扣除施肥带入的硫素、大气沉降和灌溉水硫的给源外,早稻-晚稻轮作制需补充22.35 kgS/hm2硫素,花生-甘薯轮作制需补充64.89 kg/hm2硫素,才能维持土壤硫素输入与输出的平衡。178个土壤样品有效硫含量测定结果表明,当前闽东南耕地土壤有效硫平均为26.2mg/kg,其中水田为22.35 mg/kg,旱地则为28.31 mg/kg,低于有效硫临界指标的土样数占总数的69.0%,有效硫含量属于中等级别的只占16.3%,说明硫已成为闽东南耕作土壤的养分限制因子之一。  相似文献   

16.
The structure and energy conservation characteristics of hybrid desiccant cooling system with condensation heat recovery are introduced briefly. Based on the first and second law of thermodynamics, a system thermodynamic model is established and the solution process given in a diagram. The dehumidification capacity is calculated under different exergy efficiency and indoor sensible heat conditions. The calculation results show that the desiccant wheel barely can compensate for the humidity load of outdoor air under with a ventilation rate of providing fresh air once per hour; when the fresh air rate of ventilation is limited to 0.5 times per hour, however, the desiccant wheel possess sufficient capacity under relatively large wheel exergy efficiency and high sensible heat load.  相似文献   

17.
生态环境承载力是区域可持续发展研究的重要内容。本文结合海南省社会、经济、环境现状,构建压力-状态-响应(P-S-R)模型,选取27个指标构建海南省生态环境承载力评价指标体系,采用GIS空间分析法和模糊综合评价法,对海南省18个市县生态环境承载力的时空差异进行研究。研究结果表明:海南省生态环境状况较好,生态环境承载力的整体水平较高。随着社会经济的发展,绝大部分市县的I级隶属度值不断增大,生态环境承载力整体呈现不断上升的趋势。从各市县的对比分析来看,海南省各市县的生态环境承载力呈现东部-中西部-北部递减的态势。  相似文献   

18.
In this paper, the mathematical model for gear planing of precise and hardened gear is established. The computational charts and results for the tooth edge height,cutter edge contact length and cutter area are given out to improve the present planing technique.  相似文献   

19.
基于标记控制分水岭算法的树冠高程模型分割   总被引:1,自引:1,他引:0  
树冠高程模型是树冠表面模型和数字高层模型的差值,是森林资源调查的重要数据源。笔者提出利用标记控制分水岭算法进行树冠高程模型分割的方法,首先用高斯滤波平滑树冠高程模型,对树冠边缘做初步检测,然后利用形态学重构方法进行树冠形状确认,在此基础上进行二值图像的距离变换和h-minima变换,并标记树冠顶部,最后对实验数据进行分水岭分割,实现单株木树冠边缘勾勒。误差分析表明,该方法能有效提高分割正确率,当结构元素和h-minima变换中的参数分别等于3、1.5时,树冠分割正确率为78.5%。  相似文献   

20.
稻飞虱成虫有虫丛率与虫口密度关系的研究   总被引:1,自引:1,他引:0  
探索利用稻飞虱成虫有虫丛率估测成虫虫口密度的方法和途径。本文基于稻飞虱成虫种群发生的田间调查数据,用种群密度(y)和有虫丛率(x)分别拟合指数函数、幂函数、一元二次函数、一元三次函数、直线函数和对数函数6种不同模型。结果表明,以一元三次函数方法估计精度最高,误差小,应用效果最好,并根据最优数学模型建立平均虫口密度(y)与有虫丛率(x)的关系速查表。生产中可以应用拟合的最优数学模型对田间稻飞虱成虫的发生进行监测。  相似文献   

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