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1.
针对多出救点、多物资、物资连续消耗的应急调度模型,提出了一种新的考虑连续消耗的多出救点、多物资应急调度算法,该算法在依次选择出救点的过程中,综合考虑了每一个出救点满足灾区需求的能力大小和该出救点的选择对选择下一个出救点的影响,从而得到了一系列非劣候选出救点,然后让每一个候选出救点尝试参与出救,来寻找出救点最少的出救方案.并通过一个实例验证了该算法的优越性和有效性.  相似文献   

2.
面向脉冲需求的应急资源调度问题研究   总被引:1,自引:0,他引:1  
在应急资源需求点和可行的出救点已经明确的情况下,提出了一种具有脉冲需求特性的应急资源调度方法.首先,将脉冲消耗应急问题的研究范围限定为各出救点可用资源完全能够满足应急资源脉冲需求的调度问题,从理论上证明了已有的应急资源满足调度需求的充要条件,并进一步给出了应急时间最早的资源调度方案.在此基础上,分别给出了脉冲需求条件下应急时间最早和应急出救点数最少的算法步骤,并应用数学归纳法进行了证明.算例结果表明,该研究方法能够有效地获得多种最优应急决策方案,为面向脉冲需求的应急资源调度问题提供决策参考.  相似文献   

3.
当突发事件发生时,迅速地制定一个合理的调度方案对及时救援是非常关键的。本文针对应急系统多点出救的特点,首先研究了单资源应急调度模型中应急时间最早、出救点数目最少的两阶段模型。其次研究了消耗速率为函数的连续型多资源应急调度模型,该模型通过求取每种资源的最早应急时间得到了多资源调度的最早应急时间,进一步探讨了应急时间最早、出救点数目最少的多资源调度方法。数值算例表明了算法的有效性和实用性。  相似文献   

4.
针对多资源应急问题的特点,本文建立了在多资源多出救点的应急系统中基于"应急开始时间最早"和"出救点数目最少"的多目标调度模型,并给出一简便算法,实现该问题的求解,算例及实际应用取得了令人满意的效果。  相似文献   

5.
拟订了带传动多目标优化设计的数学模型。采用正态模糊分布,将理想解和非劣解转化为目标函数值空间上的模糊子集,藉助于贴近度方法,从非劣解中找出了最贴近理想的最优解。  相似文献   

6.
多资源非恒定消耗应急调度优化模型研究   总被引:1,自引:0,他引:1  
针对应急系统中多种应急物资的非恒定消耗情况,建立了以应急出救点数最少为上层优化目标,应急开始时间最早为下层优化目标,以应急物资连续消耗为约束条件的二层优化数学模型.同时,通过引入调整条件调整可行解,使参与应急的出救点数最少.给出了模型的解法,用算例验证了所建立模型的合理性与算法的有效性.结果表明,在应急系统中多种应急物资的非恒定消耗条件下,应用该模型可求得出救点数最少.  相似文献   

7.
多资源消耗应急系统调度模型及算法   总被引:2,自引:0,他引:2  
结合应急系统多点出救的特征,研究了在资源消耗速率为非负可积函数的情况下,构建基于应急时间最早的连续型应急资源调度模型,并给出相应算法.对模型及所提出的求解算法进行实证研究,结果表明:模型与算法有效,并能对突发事件应急资源调度起到积极的作用.  相似文献   

8.
针对多独立搜索引擎组合调度时查询精度、查询完全度和响应时间不理想等问题,结合元搜索引擎调度特点对多独立搜索引擎组合调度进行动态优化。文中借鉴小生境思想,将小生境技术与遗传算法相结合,提出了一种多目标组合优化调度的改进小生境遗传算法。该算法使每个个体在其小生境内进行局部寻优操作,保证了群体的多样性,增强了局部搜索能力,抑制了种群的早熟现象。在多个子目标不能同时达到最优时,采用个体综合适应度对各个目标函数的适应度进行加权,来协调优化各搜索引擎的组合,找到搜索引擎组合调度序列的非劣解。仿真实验结果表明该算法提高了元搜索引擎的调度效率,在查询精度和计算速度上均优于常用的查询优化技术。  相似文献   

9.
改进小生境遗传算法在元搜索引擎调度优化中的研究   总被引:1,自引:1,他引:0  
针对多独立搜索引擎组合调度时查询精度、查询完全度和响应时间不理想等问题,结合元搜索引擎调度特点对多独立搜索引擎组合调度进行动态优化。文中借鉴小生境思想,将小生境技术与遗传算法、相结合,提出了一种多目标组合优化调度的改进小生境遗传算法。该算法使每个个体在其小生境内进行局部寻优操作,保证了群体的多样性,增强了局部搜索能力,抑制了种群的早熟现象。在多个子目标不能同时达到最优时,采用个体综合适应度对各个目标函数的适应度进行加权,来协调优化各搜索引擎的组合,找到搜索引擎组合调度序列的非劣解。仿真实验结果表明该算法提高了元搜索引擎的调度效率,在查询精度和计算速度上均优于常用的查询优化技术。  相似文献   

10.
重大自然灾害频发对国家安定和人民生命安全带来威胁的同时也会造成严重的经济损失。如何在灾后将受灾点所需应急物资快速、精准运送到位受到了广泛关注。该文针对重大自然灾害事件救援特点,考虑在不确定性条件下,兼顾应急调度成本最低和调度时间最短两目标,构建面向多灾害点的应急物资智能调度模型。研究选取2021年中国河南特大暴雨灾害为典型案例,基于三角模糊数方法对不确定变量进行表示,从而将所构建的模型转变为确定性多目标应急物资智能调度模型,同时引入二维Euclid距离赋权进行模拟运算,对模型求解。进一步,利用LINGO软件计算得到各出救点至各受灾点分阶段应急物资调度方案。研究结果表明,利用该模型得到的模拟结果与现实要求接近,能够满足重大自然灾害下多灾害点应急物资调度需求,可为决策者制定有效救灾策略提供参考。  相似文献   

11.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

12.
Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to  相似文献   

13.
Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications (up to 574.8 km/ h test speeds or 380 km/h commercial speeds) in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.  相似文献   

14.
15.
Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.  相似文献   

16.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

17.
为了有助于提高英文爱好者的个人情操、文化素养和学习兴趣,以及专业人员对英语学习和研究进行多途径的探索,本文通过一些精选诗歌的引证和分析,着重论述了喻类修辞法在英文诗歌中的运用其及效果。  相似文献   

18.
Tennessee Williams is considered as one of the most important American playwrights since World War II.The Glass Menagerie is his first successful drama,which describes a tragic situation of family and means to say that Man is unable to change the miserable life,no matter whatever means he try,This essay focuses on the analysis of the arrangement of the four main characters:Laura.Amanda,Jim and Tom to reveal the theme.Laura is fragile.Amanda is brave.Jim is vital.Tom is sensible.And all of them develop and try the different means to struggle against life,but fail tragically.With the evidence,the paper comes to conclusion naturally that Man is unable to change the miserable life,and he dooms to fail.  相似文献   

19.
The aim of this study is to investigate the diversity of Retama raetam root-nodule bacteria isolated from arid regions of Tunisia. Twelve isolates, chosen as representative for different 16S rRNA gene patterns, were characterized by 16S rRNA gene sequencing and phenotypic analysis. Isolates were assigned to Sinorhizobium, Rhizobium and Agrobacterium. Symbiotic properties of Sinorhizobium and Rhizobium isolates showed a large diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Strain RK 22 identified as Rhizobium was the most effective isolate.  相似文献   

20.
正Recently,docking has been widely used to predict the binding-modes of protein-inhibitors,when the crystal complexes structure was absent.Most docking algorithms are able to generate a large number of probable conformations,it,however,is difficult to effectively evaluate these docking poses and identify the most reasonable bindingmode.In the present study,on the basis of the crystallographic data of human 3-hydroxy-3-methylglutaryl coenzyme  相似文献   

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