异地协同设计PDM系统数据模型的建立

主要阐述了在异地协同设计时,对PDM系统大容量文件存储的设计,在分析了各种存储方式的优势与不足之后,提出了符合项目需求的存储方案。在设计过程中,坚持采用模型驱动的设计方法构建系统数据模型,以PDM系统中的项目管理子功能为例,从精确建立领域模型过渡到数据模型,使数据模型与企业现状很好地结合。

城市复杂道路网络T-GIS数据模型

针对现代城市复杂交通网络现状,提出以交通地理信息系统(transportation-geographic information system,T-GIS)数据模型来描述、城市复杂道路网络的复杂特性.首先以复杂网络理论验证城市道路网络的复杂特性,其次从道路网络综合描述属性表达和网络数据逻辑关系3个方面构建城市复杂道路网络T-GIS数据模型.实践证明,本T-GIS模型具有很好的应用效果,很好表达道路网络空间信息及复杂逻辑关系,为道路拥堵和路径诱导及城市道路网络演化研究提供所需数据,且具有较好的推广价值.

基于ARM的单一数据模型OS中断技术的研究

介绍了基于Arm单一数据模型操作系统的特点,重点分析了ARM中断技术的特点,提出了基于ARM的单一数据模型操作系统异常中断处理的设计方案,结合ARM异常中断处理的特点提出了一种基于ARM的单一数据模型操作系统中断设计方法。

基于ARM的单一数据模型OS内核的启动技术研究

介绍了基于ARM的单一数据模型操作系统的概念和PC机与ARM处理器启动引导的特点与差别,重点分析了ARM启动引导技术的特点,最后提出了一种有效的基于ARM单一数据模型操作系统内核的启动引导方案。

桥梁工程设计数据库管理系统的研究

基于关系数据库理论的观点，结合工程的实际需要，研究开发了“桥梁工程设计数据库管理系统”。本文讨论了系统分析、数据模型选择、系统的总体设计、一般应用模块。

图书微机网络管理系统的分析和设计

本文介绍了微机局域网络技术在图书馆自动化管理中的应用，对图书微机网络管理系统的分析和设计进行了论述。

区域军事地理信息系统(MGIS)的设计与实现

区域军事地理信息系统是ＧＩＳ理论和技术在军事领域应用的一个事例，本文介绍了该系统的设计目标，设计原则，系统组成，技术途径及系统建设的体会。

DSS Scheme for Operation Optimization Problem on Power Plants

Based on the target analysis of the operation optimization for power plants, a novel system scheme called operation optimization decision support system (OODSS) is brought forward. According to the structure and design thinking of decision support system (DSS), the overall structure of the OODSS is studied, and the scheme of the sub systems in the OODSS such as the user interface system, the problem processing system, the database system, the model base system, the expert system (ES) and the data mining sy...

金融发展对城乡收入差距的地区异质性研究

改革开放以来,金融业对我国经济的持续快速发展起到较大的促进作用,但与此同时城乡收入差距逐渐扩大,引起人们广泛关注。运用系统GMM估计的动态面板数据模型,实证考察我国金融发展与城乡收入差距之间存在的内在关系及其地区异质性。实证结果表明:金融效率对城乡收入差距具有显著的负向作用,其影响程度按东、西、中部地区的顺序依次递增;金融规模对中部地区的城乡收入差距具有显著的正向作用,但对东部和西部地区的影响不显著。根据研究结论,有针对性地为缩小城乡收入差距提出相关政策建议。

The Technology of Data Conversion Among Different DBMSs

In the application development of database,sharing information a- mong different DBMSs is an important and meaningful technical subject. This paper analyzes the schema definition and physical organization of popu- lar relational DBMSs and suggests the use of an intermediary schema.This technology provides many advantages such as powerful extensibility and ease in the integration of data conversions among different DBMSs etc.This pa- per introduces the data conversion system under DOS and XENIX operating systems.

Analysis and Design of Soils and Terrain Digital Database (SOTER) Management System Based on Object-Oriented Method

A SOTER management system was developed by analyzing, designing, programming, testing, repeated proceeding and progressing based on the object-oriented method. The function of the attribute database management is inherited and expanded in the new system. The integrity and security of the SOTER database are enhanced. The attribute database management, the spatial database management and the model base are integrated into SOTER based on the component object model (COM), and the graphical user interface (GUI) for Windows is used to interact with clients, thus being easy to create and maintain the SOTER, and convenient to promote the quantification and automation of soil information application.

Semiparametric Regression and Model Refining

This paper presents a semiparametric adjustment method suitable for general cases.Assuming that the regularizer matrix is positive definite,the calculation method is discussed and the corresponding formulae are presented.Finally,a simulated adjustment problem is constructed to explain the method given in this paper.The results from the semiparametric model and G_M model are compared.The results demonstrate that the model errors or the systematic errors of the observations can be detected correctly with the semiparametric estimate method.

A Trajectory-Oriented, Carriageway-Based Road Network Data Model,Part 2:Methodology

This is the second of a three-part series of papers which presents the principle and architecture of the CRNM, a trajectory-oriented, carriageway-based road network data model. The first part of the series has introduced a general background of building trajectory-oriented road network data models, including motivation, related works, and basic concepts. Based on it, this paper describs the CRNM in detail. At first, the notion of basic roadway entity is proposed and discussed. Secondly, carriageway is selected as the basic roadway entity after compared with other kinds of roadway, and approaches to representing other roadways with carriageways are introduced. At last, an overall architecture of the CRNM is proposed.

A Spatio-temporal Data Model for Road Network in Data Center Based on Incremental Updating in Vehicle Navigation System

The technique of incremental updating,which can better guarantee the real-time situation of navigational map,is the developing orientation of navigational road network updating.The data center of vehicle navigation system is in charge of storing incremental data,and the spatio-temporal data model for storing incremental data does affect the efficiency of the response of the data center to the requirements of incremental data from the vehicle terminal.According to the analysis on the shortcomings of several typical spatio-temporal data models used in the data center and based on the base map with overlay model,the reverse map with overlay model (RMOM) was put forward for the data center to make rapid response to incremental data request.RMOM supports the data center to store not only the current complete road network data,but also the overlays of incremental data from the time when each road network changed to the current moment.Moreover,the storage mechanism and index structure of the incremental data were designed,and the implementation algorithm of RMOM was developed.Taking navigational road network in Guangzhou City as an example,the simulation test was conducted to validate the efficiency of RMOM.Results show that the navigation database in the data center can response to the requirements of incremental data by only one query with RMOM,and costs less time.Compared with the base map with overlay model,the data center does not need to temporarily overlay incremental data with RMOM,so time-consuming of response is significantly reduced.RMOM greatly improves the efficiency of response and provides strong support for the real-time situation of navigational road network.

A Survey of MapReduce Based Parallel Processing Technologies

Along with the increasing Big Data challenges, the MapReduce based systems are extensively welcomed, because of their remarkable simplicity and scalability. However, from the first day MapReduce is proposed, its argument with parallel Dt3MSs never stops, as it over-focuses on the scalability but overlooks the efficiency. Accordingly, extended systems are proposed in order to improve the peDbrmance on the limited scale clusters. In the meantime, traditional RDBMS technologies like structured data model, transaction, SQL, etc. are also getting more attention. This paper reviews such systems, from Google and also the third parties, trying to indicate the directions for the future research.

Quality Assessment of Attribute Data in GIS Based on Simple Random Sampling

On the basis of the principles of simple random sampling, the statistical model of rate of disfigurement (RD) is put forward and described in detail. According to the definition of simple random sampling for the attribute data in GIS, the mean and variance of the RD are deduced as the characteristic value of the statistical model in order to explain the feasibility of the accuracy measurement of the attribute data in GIS by using the RD. Moreover, on the basis of the mean and variance of the RD, the quality assessment method for attribute data of vector maps during the data collecting is discussed. The RD spread graph is also drawn to see whether the quality of the attribute data is under control. The RD model can synthetically judge the quality of attribute data, which is different from other measurement coefficients that only discuss accuracy of classification.

Modeling and Analysis of Data Dependencies in Business Process for Data-Intensive Services

With the growing popularity of data-intensive services on the Internet, the traditional process-centric model for business process meets challenges due to the lack of abilities to describe data semantics and dependencies, resulting in the inflexibility of the design and implement for the processes. This paper proposes a novel data-aware business process model which is able to describe both explicit control flow and implicit data flow. Data model with dependencies which are formulated by Linear-time Temporal Logic(LTL) is presented, and their satisfiability is validated by an automaton-based model checking algorithm. Data dependencies are fully considered in modeling phase, which helps to improve the efficiency and reliability of programming during developing phase. Finally, a prototype system based on j BPM for data-aware workflow is designed using such model, and has been deployed to Beijing Kingfore heating management system to validate the flexibility, efficacy and convenience of our approach for massive coding and large-scale system management in reality.

Human Settlement Evaluation in Mountain Areas Based on Remote Sensing,GIS and Ecological Niche Modeling

The Qinghai-Tibet Plateau is the word＇s highest and largest plateau. Due to increasing demands for environment exploration and tourism, a large transitional area is required for altitude adaptation. Hehuang valley, which locates in the transition zone between the Loess Plateau and the Qinghai-Tibet Plateau, has convenient transportation and relatively low elevation. Our question is whether the geographic conditions here are appropriate for adapted stay before going into the Qinghai-Tibet Plateau. Therefore, in this study, we examined the potential use of ecological niche modeling （ENM） for mapping current and potential distribution patterns of human settlements. We chose the Maximum Entropy Method （Maxent）, an ENM which integrates climate, remote sensing and geographical data, to model distributions and assess land suitability for transition areas. After preprocessing and selection, the correlation between variables and spatial auto- correlation input data were removed and 106 occurrence points and 9 environmental layers were determined as the model inputs. The threshold- independent model performance was reasonable according to lO times model running, with the area under the curve （AUC） values being 0.917± 0.01, and 0.923±0.002 for test data. Cohen＇s kappa coefficient of model performance was 0.848. Results showed that 82.22% of the study extent was not suitable for human settlement. Of the remaining areas, highly suitable areas aceounted for 1.19%, moderately for 5.3% and marginally for 11.28%. These suitable areas totaled 418.79 km2, and 86.25% of the sample data was identified in the different gradient of suitable area.The decisive environmental factors were slope and two climate variables： mean diurnal temperature range and temperature seasonality. Our model showed a good performance in mapping and assessing human settlements. This study provides the first predicted potential habitat distribution map for human settlement in Ledu County, which could also help in land use management.

Mobile Internet Applications：Impact on Future Wireless Communications System

Based on the analysis of application status in real network,the trace model of some typical mobile Internet applications data is given and their impact on 2G/3G network is discussed in this paper.Furthermore,in order to support the mobile Internet application efficiently in future,the issues including the impact on the Long Term Evolution (LTE-A) system and some potential solutions for performance optimization are studied.Based on the trace data model of IM traffic,the performacne evaluaiton of LTE-A system shows that some specific configuration machanisms can play an important role in improving network system efficiency in the case of IM traffic.

Salt-Containing Extractive Distillation of 1-Propanol/Water System 1.Prediction of Salt Effect on Vapor Liquid Equilibrium

This paper has studied the vapor-liquid equilibrium （VLE） for the salt-containing extractive distillation of the 1-propanol/water system. Binary VLE data were measured for the systems of 1-propanol （1）/KAc （4）, ethanediol （3）/KAc （4）, and 1-propanol （1）/ethanediol （3）, with the VLE data correlated with the NRTL model in order to obtain the model parameters of these binary systems. The binary VLE data cited in technical literature were correlated to obtain the model parameters for other binary systems. VLE data of ternary and quaternary systems predicted by the NRTI.： model agreed well with the literature data. The influence of KAc, ethanediol, and the KAc/ethanediol mixture on volatility between 1-propanol and water was investigated respectively. Test results showed that the above-mentioned materials （KAc, ethanediol） and their mixture （KAc and ethanediol） have different influence on the volatility. When x3=0.5, and x4=0.05, the azeotropic point can be elimi- nated. The NRTL model method of salt-containing VLE is simple and effective for the prediction of the system＇s VLE data.