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1.
Considering Object oriented design, abstract mechanism of object and technology of procedure design in ObjectARX are introduced.By analyzing characteristics of power network, the puper it elaborates process of definition special object by using of open structure of AutoCAD inner database , base class provided by ARX and mechanism of calss inheritance and derivative. The class definition of elemens is also given in power system as well. Technology of data exchange is also elaborated. On this base ,object models of power CAD are constructed.Date exchange between PWCAD and the external database is also realized.  相似文献   

2.
植物已知品种数据库构建方法研究   总被引:1,自引:1,他引:0  
植物已知品种(以下简称“已知品种”)数据库是以品种性状描述、图像和DNA指纹图谱信息为核心,有效整合品种命名、审(鉴)定、保护、推广、转让、培育、栽培、繁殖、保藏等管理和技术信息,模仿人为判定过程,实现自动命名审查和近似品种筛选的高级专家系统。已知品种数据库基于网络环境设计,具有高度的共享性,可以大大提高品种保护、审(鉴)定、种子检测等管理部门的信息交流效率,是农业行政主管部门监控种子质量、维护市场秩序的重要技术支撑。已知品种数据库还可以为种子企业或育种者挑选品种、制定育种目标提供重要参考,节省社会成本。为此,通过对国内外植物品种管理信息系统进行研究,指出植物品种信息管理所应包括的基本内容和功能,得出中国已知品种数据库构建方法。  相似文献   

3.
The nodes of BOM may appear repeatedly in the different layers. While the structure of traditional tree model can not express the relation between these nodes expediently. By analyzing the localization of tree model BOM, this paper studies the essential structure of BOM and puts forward the drected-gragh with weightings of BOM. Then it provides corresponding realization of relation database and studies the method of maintenance. It also discusses the expansion of attribute based on enterprise' s requirement. Finally it provides the thinking of searching, relevant algorithm and the method of programming language realization. This kind of BOM offers foundation for the integration of information and data in PDM/CAPP/CIMS/ERP.  相似文献   

4.
One can get the digital solutions and the symbolic solutions of linear circuits in the same time by using coates graph. However, the practicability of the method depends on the effeciency of generation of 1-factors and 1-factorial connections. Based on the way of depth first searching,an algorithm was presented here for solving all 1-factors and 1-factorial connections. And a proctical programm has been compiled.  相似文献   

5.
农业对外经济合作专家数据库构建与专家评价研究   总被引:1,自引:1,他引:0  
为了提高中国农业对外经济合作专家的使用效率及效果,提出了建立农业对外经济合作专家数据库和建立专家评价模型的解决思路。对于专家数据库的建立,从入库专家的选择条件、入库专家信息的来源方式、原始信息的整理与分类、专家数据库信息的添加、专家数据库的完善与动态管理等方面详细阐述了专家数据库的数据内容搭建和完善的过程和方法;对于专家的评价方法,构建了2级评价指标体系,并综合运用德尔菲法、层次分析法科学地确定了各指标的权重系数;此外,还给出了专家评价的综合评价量表和具体算法。研究成果可以在农业对外经济合作主持部门开展具体工作时,发挥基础性的作用。  相似文献   

6.
为了验证AutoCAD在测量苹果砧木枝条解剖结构中的应用,以2年生Y-1苹果矮化砧木植株为试材,实例介绍了用AutoCAD软件测量解剖结构组织长度及面积的方法,通过分别用IPE法和AutoCAD法测量了精确1mm和1mm2台尺的长度,苹果砧木Y-1 1年生枝各组织厚度、不同部位导管及筛管面积,比较了2种方法的精确度及对苹果砧木枝条解剖结构各组织测量值的差异显著性。结果表明,和IPE法相比,AutoCAD法测量精确度较高,且用2种方法测量苹果砧木Y-1 1年生枝横断面各组织厚度及面积的测量值差异不显著。得出,用AutoCAD软件对苹果砧木1年生枝横断面各组织厚度和面积进行测量比用IPE软件更精确、便捷,功能强大,提出用AutoCAD软件测量苹果砧木枝条解剖结构各组织长度与面积是一种值得推荐的方法,可在其他植物组织解剖结构的显微测量中推广应用。  相似文献   

7.
ABSTRACT Local and regional employment growth is generally studied either by searching for local qualitative explanatory factors such as governance, synergy between firms, and milieu effects, or by searching for general growth factors using statistical techniques. The body of work that relies on this approach has tended, in keeping with economics’ nomothetic tradition, to assume that local and regional growth factors are constant over space. The focus of this paper is on exploring the spatial stationarity of employment growth factors in Canada, but it also seeks to clarify some of the broad principles behind spatial regression techniques in order to provide a point of entry and a conceptual framework for empirical researchers. To do so, we apply a recently developed technique, Geographically Weighted Regression (GWR), and we explore the method's advantages and limits for answering our research question. We find evidence that growth factors differ across Canada, but we also conclude that the GWR technique, given the number and shape of regions available for our analysis and given certain limitations that are currently inherent to the method, can only provide tentative and exploratory results.  相似文献   

8.
Based upon the conception of the least loop,the most loop and direction factor presented by the author firstly,the algorithm of searching out the least and most loops has been designed.By building the adjoining matrix, confirming the start-point of searching,vectorizing the searching sides,calculating the direction factor of adjoining sides,we can search out the next side of the least loop or the most loop rapidly.With a valid searching side being confirmed at every searching and the searching scope being reduced by forming degenerate graph,the time compexity of the algorithm is much less. In the research of the automatic calculating system of construction quantities, the problem of houses partition and out-wall partition had been solved succesfully by utilizing this searching algorithm.  相似文献   

9.
10.
北京农作物种质资源信息服务平台的设计与构建   总被引:3,自引:1,他引:2  
围绕北京籽种产业发展,为促进北京农作物种质资源的高效利用,采用.NET和SqlServer2005数据库技术进行开发,搭建开放融合的北京农作物种质资源信息服务共享平台。实现种质资源自动建库、统一管理和异构种质资源统一检索的功能,将分散在各个单位及部门的种质资源集中管理,实现种质资源网络共享。本文主要阐述了系统平台框架结构、功能设计、自动建库系统结构的设计方法和原理,初步建成了北京农作物种质资源共享服务平台。  相似文献   

11.
在储藏过程中,粮堆可能出现发热。霉变,虫害孳生等情况。当储粮水分含量高,生虫霉变时,会引起粮堆温度升高,因此,粮堆温度是储粮状态的重要标志,必须准确地检测并适时显示,本文将计算机图形技术引入粮情检测,利用图形消隐向用户提供直观生动的三维温度分布图,用户可用鼠标选取某一点以观察,显示该点的空间位置及温度值,同时显示纵横剖面图,便于发现异常温度点,用Visual Basic6.0编制绘图程序,为研制,开发具有自主产权的储粮信息管理系统奠定了基础。  相似文献   

12.
为解决关注的研究领域中检索关键文献效率低的问题,本研究利用R语言bibliometrix包,以土壤氨(NH3)挥发为例,进行文献计量分析(包括关键词共现分析、共词分析及高被引论文分析),探索文献计量分析在Web of Science核心数据库中精确快速检索文献的方法。研究发现,第一次文献检索时,输入少量简单关键词(土壤氨挥发),检索出来的文献数量达到3573篇,且其中的高被引论文多数与主题词关系不大。对第一次检索结果进行文献计量分析,根据关键词聚类、共词分析结果,增加了关键词进一步检索文献,进行上述过程2次后,检索的文献数目已降至160篇,其中的Top 10高被引论文与检索主题(土壤NH3挥发)紧密相关。此时,假设需进一步精确查找关于土壤NH3挥发与水分、温度、管理方面研究文献,再次分别增加关键词进一步检索,分别检索出26、20和28篇相关文献,且关键词及高被引论文分析结果也再次验证了方法的准确性。本研究中利用文献计量分析快速检索权威、关键文献的方法切实可行。在大数据背景下,文献计量结合R-bibliometrix工具,有助于快速、精确地检索关键文献、获取科研思路及解决方法。  相似文献   

13.
A developing method is given which based on object-oriented modeling techniques for management information systems.The modeling techniques,especially,from CDM to PDM conversion,make it possible that the method can be used for developing such management information systems which based on relational database.The result shows that it can raise the efficency of the system developing,improve the system tability,enhance the system maintenability.  相似文献   

14.
曲线和曲面拟合的改进缩张算法   总被引:1,自引:0,他引:1  
本文对缩张算法进行了多处改进,其中最主要的是与基于数值微分的改良高斯-牛顿法相结合,形成了曲线与曲面拟合的改进缩张算法。新算法不需提供非线性方程的偏导数,但可利用近似偏导数指导搜索方向,提高搜索效率。改进缩张算法减少了复杂非线性方程拟合的运算负荷,提高了利用度点反馈调节搜索步长和区域的敏感度,增强了跳出局部最优陷阱的能力。新算法可在较大初值范围内实现全局最优拟合。本文以3个不同类型的实例验证了新算法的拟合功效。编制了可动态显示拟合过程的Matlab程序,可供曲线和曲面拟合应用者使用。  相似文献   

15.
本研究运用农业信息技术原理与方法,以姜堰市为例,初步开发出了功能全面、内容丰富、现势性强、图形生产力高的基于VB 6.0和MapObjects 2.3的县域水稻精确栽培决策支持系统软件。该系统涵盖了基本苗精确定量、精确施氮、精确灌溉、精确测产及气象数据库、智能学习等内容。该系统还具有电子地图浏览导航与地理信息系统空间数据查询功能。经初步试用,系统的功能可用性、功能可靠性、易用性较强,用户满意度较高。  相似文献   

16.
This paper proposes an improvement for the traditional Optical Algorithm, and presents a new way to image segmentation in a complex background. In addition, combined with the neural network, the system can locate the possible human faces successfully by means of two-step location model. In our system, the searching and locating of the human face is the most important stage. According to this, the authors adopt the two-step way to run, firstly they take up the segmentation of the candidate human face areas and then the accurate face locating based on the neural network is used. This algorithm is fast and robust. Experimental results with real scene images are given out there, and all these prove that two-step method gains many advantages in the course of human face location with motion information, such as real-time, robustness and practicality. In addition, the proposed system is also the fundamental and important part of the perfect human face recognition system.  相似文献   

17.
Steady-state probability, frequency and duration are the three main indices in reliability evaluation of the HVDC systems. Generally, they are solved by numerical methods. Their topolgical formulaes are derived by using the basic theory of ccates graph and considering conditions for some particularity of state-space in this paper. A set of generalised formulaes can be applied to obtain these indices expression about reliability parameters of components. Finally,an example is given to illustrate and verify this method.  相似文献   

18.
为梳理改善农村人居环境的研究状况及未来发展趋势,以中国学术期刊网络出版总库为研究平台,收集了2010—2021年围绕“改善农村人居环境”为中心点的中文样本文献1617篇,借助Citespace软件,运用科学知识图谱相关理论和科学计量学的方法,对文献进行了聚类分析、关键词突现分析以及研究热点趋势分析,结果表明:(1)在改善农村人居环境过程中,国内的学者聚焦于农村养老、农村公路、厕所改造、农村垃圾处理及农村污水处理等5个方面的研究,目前各方面都已取得阶段性的进展,结合关键词突现分析和研究热点趋势分析,在未来一段时间,5个方面依然是研究的热门主题。(2)现有关于改善农村人居环境的研究多以定性为主,剖析较为浅显,定量分析的文章较少,未来的研究宜将2种方法结合。  相似文献   

19.
应用3种保鲜剂配方处理荷花鲜切花,结果表明,3种保鲜剂均能延长荷花的瓶插寿命,尤其是配方Ⅱ处理:保鲜剂A 蔗糖2% 保鲜剂B,且在8~10℃中保鲜的效果最佳,保鲜期可达到9天以上。另外,环境气温越高其保鲜寿命越短。  相似文献   

20.
大豆尿黑酸叶绿基转移酶基因的克隆与进化分析   总被引:1,自引:0,他引:1  
采用基于EST的电子克隆方法,以拟南芥(Arabidopsis thaliana)的尿黑酸叶绿基转移酶基因(Homogentisate phytyltransferase,HPT)cDNA序列为信息探针,对大豆的EST数据库进行同源检索筛选,获得了1 777 bp长大豆HPT基因的cDNA序列(GenBank登录号为:AY956421),经RT-PCR扩增、分子克隆和序列分析验证,表明与电子克隆序列一致;该基因具有完整的开放阅读框架(ORF,173~1 408 bp),推测编码411个氨基酸的蛋白。该蛋白与拟南芥(Ara-bidopsis thaliana)、苜蓿(Medicago sativa)、水稻(Oryza sativa)、玉米(Zea mays)、光合集胞蓝细菌(Synechocystis)的序列进行了比较,发现该基因具有保守性。  相似文献   

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