编者的话

“逝者如斯夫，不舍昼夜”。岁月的脚步匆匆而过，从1998年1月创刊至今,《自动化信息》已经走过了整整10个春秋。

本刊2005年上半年参展计划

3月1～4日 西安 第七届中国(西安）国际工业控制、仪器仪表、计量测试展览会。

Effect of information delay on string stability of platoon of automated vehicles under typical information frameworks

The effect of the information delay, which was caused by thc naturc of the distance sensors and wireless communication systems, on the string stability of platoon of automated vehicles was studied. The longitudinal vehicle dynamics model was built by taking the information delay into consideration, and three typical information frameworks, i.e., leader-predecessor framework （LPF）, multiple-predecessors framework （MPF） and predecessor-successor framework （PSF）, were defined and their related spacing error dynamics models in frequency domain were proposed. The string stability of platoon of automated vehicles was analyzed for the LPF, MPF and PSF, respectively. Meanwhile, the related sufficient string stable conditions were also obtained. The results demonstrate that the string stability can be guaranteed tbr the LPF and PSF with considering the information delay, but the ranges of the control gains of the control laws are smaller than those without considering the information delay. For the MPF, the ＂weak＂ string stability, which can be guaranteed without considering the information delay, cannot be obtained with considering the information delay. The comparative simulations further demonstrate that the LPF shows better string stability, but the PSF shows better string scalable performance.

Using Sobel Operator for Automatic Edge Detection in Medical Images

The problems of installation and integration of complex suite of software for processing medical images. Based analysis of the situation is realized in an easier integration of an automated system using the latest information technologies using the web - environment for analysis and segmentation of DICOM - images.

Automatic Change Detection of Geo-spatial Data from Imagery

The problems and difficulty of current change detection techniques are presented. Then, according to whether image registration is done before change detection algorithms, the authors classify the change detection into two categories:the change detection after image registration and the change detection simultaneous with image registration. For the former, four topics including the change detection between new image and old image, the change detection between new image and old map, the change detection between new image/old image and old map, and the change detection between new multi-source images and old map/image are introduced. For the latter, three categories, i.e. the change detection between old DEM, DOM and new non-rectification image, the change detection between old DLG, DRG and new non-rectification image, and the 3D change detection between old 4D products and new multi-overlapped photos, are discussed.

Constructing a taxonomy to support multi-document summarization of dissertation abstracts

This paper reports part of a study to develop a method for automatic multi-document summarization. The current focus is on dissertation abstracts in the field of sociology. The summarization method uses macro-level and micro-level discourse structure to identify important information that can be extracted from dissertation abstracts, and then uses a variable-based framework to integrate and organize extracted information across dissertation abstracts. This framework focuses more on research concepts and their research relationships found in sociology dissertation abstracts and has a hierarchical structure. A taxonomy is constructed to support the summarization process in two ways： （1） helping to identify important concepts and relations expressed in the text, and （2） providing a structure for linking similar concepts in different abstracts. This paper describes the variable-based framework and the summarization process, and then reports the construction of the taxonomy for supporting the summarization process. An example is provided to show how to use the constructed taxonomy to identify important concepts and integrate the concepts extracted from different abstracts.

Discussion on the Design of E-commerce Automatic Operation Module

E-commerce refers to a kind of business and trade activities, which are conducted under the situation that buyers and sellers do not meet each other by using a fast, easy and low-cost way. Along with the promotion and application of computer office automation, it is necessary for e-commerce module to develop towards automation, in which the core lies in making a good design for operation module. In this paper, the promotion of e-commerce in the information age is reviewed by the authors, the unique characteristics of e-commerce functional modules are analyzed, and also the most important point of the design of e-commerce automatic operation module is discussed. Hopefully, helps can be provided for relevant follow-up studies in the future.

Discussion on the Design of E-commerce Automatic Operation Module

E-commerce refers to a kind of business and trade activities, which are conducted under the situation that buyers and sellers do not meet each other by using a fast, easy and low-cost way. Along with the promotion and application of computer office automation, it is necessary for e-commerce module to develop towards automation, in which the core lies in making a good design for operation module. In this paper, the promotion of e-commerce in the information age is reviewed by the authors, the unique characteristics of e-commerce functional modules are analyzed, and also the most important point of the design of e-commerce automatic operation module is discussed. Hopefully, helps can be provided for relevant follow-up studies in the future.

A Spatialization-based Method for Checking and Updating Metadata

In this paper the application of spatialization technology on metadata quality check and updating was dis-cussed. A new method based on spatialization was proposed for checking and updating metadata to overcome the defi-ciency of text based methods with the powerful functions of spatial query and analysis provided by GIS software. Thismethod employs the technology of spatialization to transform metadata into a coordinate space and the functions ofspatial analysis in GIS to check and update spatial metadata in a visual environment. The basic principle and technicalflow of this method were explained in detail, and an example of implementation using ArcMap of GIS software wasillustrated with a metadata set of digital raster maps. The result shows the new method with the support of interactionof graph and text is much more intuitive and convenient than the ordinary text based method, and can fully utilize thefunctions of GIS spatial query and analysis with more accuracy and efficiency.

CIM Model Extension for Intelligent DAS of Smart Power Grid in Korea

The CIM （common information model） is an abstract information model that can be used to model an electrical network and various equipments used on the network. By using a common model, utilities and vendors can reduce their integration costs, which should allow more resources to be applied toward increased functionality for managing and optimizing the electrical system. As a part of smart grid, the SPG （smart power grid） was built on Jeju Island. The SPG consists of IDAS （intelligent distribution automation system）, substation automation system, intelligent transmission system, and active telemetrics system. To integrate these systems which have different operating systems and platforms CIM standard was used. But IDAS has many functions and advanced algorithms not defined in CIM. In this paper, the authors introduce how to develop and extend the CIM model for managing the IDAS.

Dynamic Crop Information System Design and Implementation Based on 3 s Technology in Shaanxi Province

By using 3s technology, the dynamic crop information system can be developed to meet the needs of sharing the agriculture information in Shaanxi Province. The dynamic crop information system can realize the query of crop information attribute and space, and the automatic acquirement, dynamic distribution and classification analysis of crop information. In this way, the whole process of real-time management of agricultural product with information and visualization can be carried out, which is to improve the level of agriculture information management automation in Shaanxi Province.

Design of PLC Centralized Meter Reading System

With the increasing development of urban housing construction and the rapid expansion of the number of inhabitants and independent electric energy meter, a variety of tariff systems are launched, meter reading metering becomes increasingly complex, and the traditional manual meter reading is already hard to adapt to new changes. This thesis studies the design of a centralized meter reading system. This program applies PLC technology for information transfer, which guarantees the stability of system carrier communication. This system is composed of electric energy meter, collector, concentrator and other hardware, as well as communication and management software of collection copies system. It is characterized by functions of power data collection, centralization, remote transmission, distance control, electricity analysis, line loss calculation, integrated query, and time-sharing billing. Its promotion and application will necessarily provide important technical means for power supply, property and urban utilities to improve their modernized and automatic management level.