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1.
The problem of old urban district regeneration has to be solved in process of ur-ban development.According to the practice of urban construction and the current situation of urbandevelopment in our country,solving this problem is very urgent. At present.there is fewer discussionon old urban district regeneration from its economic and social effect; In this paper.by means of an-alyzing old urban district regeneration and its investment effect, a set of criteria evaluating the in-vestment effect of old urban district regeneration is eastablished. For the first tirne, a new method. Set Statistics-AHP (The Analytic Hierarchy Process)-Entropy method is adopted to evaluate the in-vestment effect,and successfully solve two critical problems,individual criterion evaluation and crit-era' s weight.  相似文献   

2.
The large deflection problem of cantilever beams is studied by means of pseudolinear approach and the result is compared with that by algorithm of nonlinear governing equation. It indicates that large deflection problem solved by pseudolinear analysis can lead to simple and precise results.  相似文献   

3.
网络农业信息标准化问题思考   总被引:2,自引:1,他引:1  
针对指数级增长、庞杂无序的网络农业信息,部分学者提出了自动采集、智能搜索等技术性解决方案,而对问题关键之所在--网络农业信息标准化的系统研究和报道并不多见。文章概述了网络农业信息资源的建设现状与存在的问题,对国内外标准化研究现状进行综述,并深入探讨了网络农业信息资源标准化中最为基础也较为关键的分类、编码、描述元数据、内容标准化及质量控制五方面问题,以期为相关研究提供建设性观点和参考。  相似文献   

4.
《保鲜与加工》1998,(2):69-72
First of all, this paper simplifies the basic equation, then the solution of the problem can be obtained by means of the method of weiqhted residue on the boundaries.  相似文献   

5.
This paper gives a new approach to solve the problem of features recognition of parts drawing form by means of multi - layers BP neural network. The concept and arithmetic of expanding property matrix of parts drawing are brought forward. A feature recognition and extraction system of 2D revolving parts drawing is developed by means of secondary development of AutoCAD R2000. These works have high theoretical and practical value.  相似文献   

6.
Newtonian n-body problem is an old, complicated problem. It is very significant to study it. Even about three problem, the completed solutions have not obtained so far. It is one hottest point studied in n-body problem. Based on some hypothesis of symmetric conditions, some necessary and sufficient conditions have been obtained with the purely algebra method. The classification of planar 5 - body central configurations is discussed , in which three class planar 5 -body central configurations are obtained.  相似文献   

7.
采用不同工艺条件测定蘑菇与黄豆芽混合汁中营养成分的含量。经测定得知,蘑菇:黄豆芽:水:1:2:3,利用内源酶水解24h,混合汁中水溶性含氮物、VC含量较高,利用内源酶或盐酸水解可显著提高还原糖浓度。  相似文献   

8.
In this paper,a numerical model of a three dimensional human torso has been presented.In this model,the torso part including anisotropic muscle layers has been discretized by means of the finite element method(FEM).The rest of torso have been divided into the surface elements by the boundary element method(BEM).This discretized model can be used in the field such as the forward problem and the inverse problem of the electrocardiogram(ECG).  相似文献   

9.
The calculating burden of the decoupling judgement of multi-area power system load frequeney centrel is very large by tranditional methods. This paper changcs the decoupling judgement problem into a minimum cost network flow problem. The solution algorithm is out-of-kilter . algorithm which is characterized by simple manipaultion, fast and reliable convergence. In the paper, we discuss and calculate the decoupling problem of two arca power system load frequency control. The results show that the proposed approach is feasible and effective.  相似文献   

10.
粮食调运优化问题过去已有研究,但是当问题较为复杂时,传统算法就要花费大量时间而且准确性也难以保证.针对这一缺陷,本文对已有的粮食调运模型进行改进,并基于该改进模型提出了一个解决粮食调运优化问题的两阶段求解方法,在第一阶段,由图搜索算法产生所有可行的运输路线,并根据约束条件对搜索树进行剪枝;在第二阶段,采用蚁群算法从第一阶段产生的可行路线集合中选取最佳路线,使总的运输成本最低.经过实例测试,该算法在粮食调运过程中具有较好的效果.  相似文献   

11.
应用水稻稻瘟病抗性基因Pi-1紧密连锁的3个微卫星标记RM144、RM224和MRG4766对黑龙江省49主栽水稻品种(系)进行抗瘟基因Pi-1检测分析。结果表明,用3个与抗瘟基因Pi-1紧密连锁的SSR标记同时对抗瘟基因Pi-1有检测是非常有效的途径,检测到富士光等14个水稻品种(系)含有Pi-1抗瘟基因,明确了该基因在黑龙江省水稻品种(系)中的分布情况,为分子育种、合理搭配种植品种等提供了理论依据。  相似文献   

12.
克服蔬菜作物连作障碍问题之研究进展   总被引:5,自引:1,他引:4  
蔬菜作物连作障碍是蔬菜生产持续发展所面临的一个重要问题,通过查阅有关克服蔬菜连作障碍的研究报告,结合作者从事相关研究的结论和进展,就蔬菜作物连作障碍产生的原因和克服的途径进行综述,以便为相关研究和类似技术的实际应用提供借鉴。大量的研究表明,引起蔬菜作物连作障碍的主要原因有土壤中有害微生物的积累、土壤的次生盐渍化、蔬菜作物的自毒作用等。通过轮作、间作套种、生物防治、选育抗重茬品种、嫁接栽培、增施有机肥等措施可以部分或全部解决蔬菜作物的连作障碍问题。  相似文献   

13.
D. G. Pederson 《Euphytica》1986,35(1):169-174
Summary Two transformations commonly used in the analysis of multilocation variety trials are the logarithmic transformation and the site mean transformation, in which each observation at a site is divided by the site mean yield prior to analysis. Expressions are derived for differences between the yields of varieties after each of these transformations, in terms of the original yields. Similar expressions are also determined for the regression mean method of estimation, which is based on linear regressions of variety means on site means. It is shown that the two transformations produce almost identical analyses of variance, and that relative yields are very similar on the three scales of measurement provided that the harmonic mean of site means is used as the predictor value in the regression method.  相似文献   

14.
According to the analysis of one-dimensional radial unsteady heat conduction in an infinite medium,a transient line-source method to measure thermal conductivity of blood is provided, which is effective,accurate and easy to be carried out. By means of this method,it takes only a few seconds to accomplish the measurement. This would be a particular advantage for blood since it coagulates very quickly. With a simple apparatus,experiment has been performed and the results match the existing data of blood' s thermal conductivity very well.  相似文献   

15.
The problem of fuzzy evaluation of environmental pollution is importantboth in environment science and in environmental protection.Usual evaluationmethods have their own characteristics.This paper puts forward a mathematicalmodel of fuzzy evaluation method in grades by means of systematic analysisfor environmental pollution.At the same time,it assigns weighted values byordering based on paired comparison.  相似文献   

16.
This paper uses motorcycle as the research object and uses ADAMS/View as tools to deal with the inconvenience of constructing Motorcycle simulation model in ADAMS/View.The parameterized design system of Motorcycle is developed according to the requirements of simulation model by using ADAMS/View secondary development technology.The system has solved very complicated problem of motorcycle modeling in ADAMS/View,whose spatial structure is very complicated,and solved the problem of model imported by other CAD software which has information lose,model scale tends to heavy,follow-up simulation difficult and so on.The system is used to make the simulation model in ADAMS/View easier for follow-up simulation according to the basic dimension of Motorcycle and user's needs,and shorten the development period of the motorcycle,reduce the development cost,and carry on the series design.  相似文献   

17.
The Postal Transportation Problem(PTP)is a very complex transportation problem. It has not any very effective solving method at present. This paper systemically analyze and define the problem according to its range, capability and time limit restrictions, random factors, dynamic factors, preferential factors, optimization objectives, cost composing, and so on. The multiobjective optimization mathematical modelof PTP is established and its relational problems are also analyzed. And the model is made up of 12 kinds of restraint conditions and three optimization objectives which are the whole transportation cost, average transportation time of mail and average use ratio of cars. This will be in favor of further study of PTP. The successful development of a logistics scheduling and dispatching optimization software based on the model and its corresponding algorithm proves the correctness of the model.[WT5HZ]  相似文献   

18.
首先论述了现行乡镇公务员绩效考核中存在的主要问题及其原因,接着,在职位分析的基础上深入研究了乡镇公务员绩效考核的指标体系,最后,以此为依据,完善了绩效考核的改革思路,确立绩效评价标准,选择了绩效评价方法,改进了绩效评价手段。  相似文献   

19.
In this paper,based on reference a method to solve the problem with equality constraints is given.A new approach for solving these problems is obtained,the number of dimensions of corresponding system or equations is less than that of the classic Lagrangian multiplier approximation.Using nonlinear equality constraints,the approximate algorithm is obtained.Moreover,the numerical difficulty is reduced by means of the new algorithm.  相似文献   

20.
Based on a non-linear system model, an adaptive control methodology is presented for a parallel AC/DC power system by means of on-line recursive parameter identifications. Taking the advantage of rapid power regulatiing ability of the DC power system and combining with the generalized minimum variance self-tuning control principles, the dynamic qualities of the controlled system has been greatly improved. Using SISO form makes the control system very simple to implement. Through the design, simulation and analysis of the self-tuning control system for a practical example, it shows that the self-tuning control strategy is very promising for AC/DC power systems.  相似文献   

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