19 resultados para MODEL-DRIVEN ENGINEERING
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
TRISO-Model(tridimensional integrated software development model)是为处理软件开发的复杂性和动态性而提出的三维集成软件开发方法学,其中,多维模型之间的语义一致性维护以及对模型应用中公共操作部分的重用,提出了基于一致语义进行模型管理的需求.给出了基于MDA(model driven architecture)进行模型管理的方法MDA-MMMethod(MDA based model management method),应用MDA的4层模型管理结构,基于MDA核心标准MOF(meta object facility)所提供的公共语义基础管理模型和元模型,MDA-MMMethod支持各种MDA模型操作标准实现在TRSIO-model应用中的重用.开发了相应的支持系统MDA-MMSystem(MDA based model management system),应用于SoftPM的项目实践中.与传统方法相比,模型应用的开发效率得到了显著提高,同时降低了开发成本.最后,给出了模型融合的应用实例介绍.
Resumo:
The Berry phase of a bipartite system described by a Heisenberg XXZ model driven by a one-site magnetic field is investigated. The effect of the Dzyaloshinski-Moriya (DM) anisotropic interaction on the Berry phase is discussed. It is found that the DM interaction affects the Berry phase monotonously. and can also cause sudden change of the Berry phase for some weak magnetic field cases. (c) 2008 Elsevier B.V. All rights reserved.
Resumo:
设计与实现面向领域应用的交互式信息可视化软件十分困难.缺乏统一的开发方法与支撑工具箱,为非专家用户提供对层次、网络、多维等数据类型的统一支持,对各种可视化技术与交互技术的统一支持,以及对信息可视化任务的统一支持.针对此问题,提出了一种模型驱动的交互式信息可视化开发方法Daisy.首先,提出了交互式信息可视化界面模型IIVM(interactive information visualization interface model);然后,提出了基于IIVM的交互式信息可视化开发方法Daisy,讨论了该方法的两个核心技术:IIVM建模与描述文件生成方法、系统自动生成方法.同时,给出了Daisy工具箱,包括Daisy建模工具、Daisy系统自动生成工具以及运行时框架与组件库.最后,给出了该开发方法与工具箱的应用实例.实例表明,该方法能够为交互式信息可视化开发的统一支撑方法问题提供一种有效的解决方案.
Resumo:
首先分析了企业对数据集成的需求,并指出数据集成所面临的主要问题.针对这些问题,提出了以企业核心数据模型为驱动的数据集成方法,而且给出了该集成方法的一种实现,称之为企业数据集成平台,并以炼化企业的具体应用为例,论述了该方法对于解决企业数据集成问题的有效性.
Resumo:
模型驱动体系是OMG提出的一种IT系统描述方法,是互操作性标准进一步的发展。文章介绍了模型驱动体系的基本概念、核心基础构造及其模型体系,并介绍了当前的应用现状。
Resumo:
流程企业生产过程反映了企业的工艺路线、资源配置及其制造能力,生产过程的稳定运行影响着产品生命周期的各个阶段,因此进行生产过程的实时监控非常必要。生产过程中的大量装置所包含的静态数据和实时的动态数据构成了生产过程监控的数据基础,因此实现生产过程的实时监控依赖于基于装置对象的生产过程的快速配置。 本文以国家高技术研究发展计划(863计划)课题“面向全流程多尺度的综合自动化集成应用平台”为背景,针对流程企业生产过程监控的具体需求,研究并开发了基于模型驱动的实时数据发布系统,实现了基于装置对象的生产过程的快速配置。论文主要工作如下: 1.给出了基于数据驱动机制的装置对象描述模型,建立了面向流程企业生产过程的装置资源库。在此基础上给出了一种基于装置对象描述模型的生产过程快速配置方法。 2.针对流程企业生产过程监控的具体需求,引入XML-QL与复合事件的时序逻辑模型,提出了一个基于XML和复合事件的发布/订阅模型,给出了基于订阅树的复合事件匹配算法。最后在生产过程模型的基础上设计了一个实时数据发布框架。 3.基于.NET平台,设计开发了基于装置对象模型驱动的实时数据发布系统,并基于某石化企业的核心数据进行了应用验证,取得了良好的效果。 关键词:生产过程监控;模型驱动;发布/订阅;复合事件
Resumo:
China's cultivated land has been undergoing dramatic changes along with its rapidly growing economy and population. The impacts of land use transformation on food production at the national scale, however, have been poorly understood due to the lack of detailed spatially explicit agricultural productivity information on cropland change and crop productivity. This study evaluates the effect of the cropland transformation on agricultural productivity by combining the land use data of China for the period of 1990-2000 from TM images and a satellite-based NPP (net primary production) model driven with NOAH/AVHRR data. The cropland area of China has a net increase of 2.79 Mha in the study period, which causes a slightly increased agricultural productivity (6.96 Mt C) at the national level. Although the newly cultivated lands compensated for the loss from urban expansion, but the contribution to production is insignificant because of the low productivity. The decrease in crop production resulting from urban expansion is about twice of that from abandonment of arable lands to forests and grasslands. The productivity of arable lands occupied by urban expansion was 80% higher than that of the newly cultivated lands in the regions with unfavorable natural conditions. Significance of cropland transformation impacts is spatially diverse with the differences in land use change intensity and land productivity across China. The increase in arable land area and yet decline in land quality may reduce the production potential and sustainability of China's agro-ecosystems. (C) 2008 Elsevier B.V. All rights reserved.
Resumo:
Five diagnostic experiments with a 3D baroclinic hydrodynamic and sediment transport model ECOMSED in couple with the third generation wave model SWAN and the Grant-Madsen bottom boundary layer model driven by the monthly sediment load of the Yellow River, were conducted to separately diagnose effects of different hydrodynamic factors on transport of suspended sediment discharged from the Yellow River in the Bohai Sea. Both transport and spatio-temporal distribution of suspended sediment concentration in the Bohai Sea were numerially simulated. It could be concluded that suspended sediment discharged from the Yellow River cannot be delivered in long distance under the condition of tidal current. Almost all of sediments from the Yellow River are deposited outside the delta under the condition of wind-driven current, and only very small of them are transported faraway. On the basis of wind forcing, sediments from the Yellow River are mainly transported north-northwestward, and others which are first delivered to the Laizhou Bay are continuously moved northward. An obvious 3D structure characteristic of sediment transport is produced in the wind-driven and tide-induced residual circulation condition. Transport patterns at all layers are generally consistent with circulation structure, but there is apparent deviation between the depth-averaged sediment flux and the circulation structure. The phase of temporal variation of sediment concentration is consistent with that of the bottom shear stress, both of which are proved to have a ten-day cycle in wave and current condition.
Resumo:
We detected the responses of summertime extreme wave heights (H-top10, average of the highest 10% of significant wave heights in June, July and August) to local climate variations in the East China Sea by applying an empirical orthogonal function analysis to Htop10 derived from the WAVEWATCH- III wave model driven by 6 hourly sea surface wind fields from ERA-40 reanalysis over the period 1958-2002. Decreases in H-top10 in the northern East China Sea ( Yellow Sea) correspond to attenuation of the East Asian Summer Monsoon, while increases in the south are primarily due to enhancement of tropical cyclone activities in the western North Pacific.
Resumo:
Global positioning system (GPS) can not only provide precise service for navigation and timing, but also be used to investigate the ionospheric variation. From the GPS observations, we can obtain total electron content (TEC), so-called GPS TEC, which is used to characterize the ionospheric structure. This thesis mainly concerns about GPS TEC data processing and ionospheric climatological analysis as follows. Firstly, develop an algorithm for high-resolution global ionospheric TEC mapping. According to current algorithms in global TEC mapping, we propose a practical way to calibrate the original GPS TEC with the existing GIM results. We also finish global/local TEC mapping by model fitting with the processed GPS TEC data; in practice, we apply it into the local TEC mapping in Southeast of China and obtain some initial results. Next, suggest a new method to calculate equivalent ionospheric global electron content (GEC). We calculate such an equivalent GEC with the TEC data along the geographic longitude 120°E. With the climatological analysis, we can see that GEC climatological variation is mainly composed of three factors: solar cycle, annual and semiannual variations. Solar cycle variation is dominant among them, which indicates the most prominent influence; both annual and semiannual variations play a secondary role and are modulated by solar activity. We construct an empirical GEC model driven by solar activity and seasonal factors on the basis of partial correlation analysis. Generally speaking, our researches not only show that GPS is advantageous in now-casting ionospheric TEC as an important observation, but also show that GEC may become a new index to describe the solar influence on the global ionosphere since the great correlation between GEC and solar activity factor indicates the close relationship between the ionosphere and solar activity.
Resumo:
Nansha Islands as sacred territory of China, containing abundant natural resources is the important area of sustaining development of Chinese people. Safeguarding and developing Nansha Islands has become one important part to develop ocean resource of China in 21 century. Engineering geological problems will be faced inevitably in the processes of engineering construction. Coral reef is a new kind of soil and rock and has special engineering characteristics. This doctoral dissertation researches deeply and systematically the regional engineering geology environmental properties and quality, engineering geological characteristics of coral reefs sand on the basis of synthetic analysis of hydrology, climate, geology, geomorphology and engineering field exploration information and combining the experimental data. 1. Put forward the division program of engineering geological environment of Nansha Islands according to the data of hydrology, geology and sediments, and also deeply study the properties of each division. Evaluate the quality of engineering geological environment by fuzzy mathematics and draw the evaluation map of quality of engineering geological environment. The research work provides background support of engineering geological environment to program of resource development in Nansha Islands. 2. Structures of coral reefs have been analyzed. The model of engineering geological zone has been proposed on the basis of geomorphologic zone and combining the strata and ocean dynamic environment. The engineering construction appropriation of each zone is praised. 3. The physical and mechanical properties of coral sands are researched. The results show that coral sands have high void ratio, non-regular shape, easy grain crushing and large compressibility. Shear-expansion takes place only at very low confining pressure and shear-contraction of volumetric strain occurs at higher confining pressure. Internal friction angle decreases with the increasing of confining pressure. The grain crushing property is the main factor influencing the mechanical characteristics. 4. A revised E-ν constitutive model is proposed which considers the change of internal friction angle with confining pressure, and parameter values are also determined. 5. The stability of Yongshu Reef by is analysed for the purpose of serving engineering struction. The process and mechanism of deformation and failure of foundation and slope is analyzed by finite-element method.
Resumo:
The microstructural heterogeneity and stress fluctuation play important roles in the failure process of brittle materials. In this paper, a generalized driven nonlinear threshold model with stress fluctuation is presented to study the effects of microstructural heterogeneity on continuum damage evolution. As an illustration, the failure process of cement material under explosive loading is analyzed using the model. The result agrees well with the experimental one, which proves the efficiency of the model.