공간 데이터베이스를 지원하기 위한 무결성 시스템의 설계

서윤석 김천과학대학 1999 김천과학대학 논문집 Vol.25 No.-

This paper describes the design of an extended spatial query processing system which provides integrity maintenance in the spatial database system that manages the correlation between spatial data and aspatial data. Geographic information system that models geographic and spatial information in the real world is implemented based on spatial database system. Spatial database system should handle data not as simple object but as abstracted complex object and maintain integrity for various derived data in the database system efficiently and represent the conceptual characteristic of spatial data as the format of the constraint. In this paper, we propose the spatial constraint language that can represent integrity information for spatial data as the format of the predicate logic in order to extend spatial query processor. The proposed spatial constraint language is stored as the format of reduced query trec in the meta database and is used as the information to guarantee the consistency of spatial database for user's query.

그리드 데이터베이스에서 질의 처리 최적화 기법

서윤석 김천과학대학 2008 김천과학대학 논문집 Vol.34 No.-

In this pager, a method of query processing optimization in the grid database is proposed. To decrease network transmission cost, frequently used data is cached from meta database. Existing cache management method has a unbalanced resource problem, because it doesn't manage replicated data in each node. Also, it increases network cost by cache misses. In the case of data modification, if cache is not updated, queries can be transferred to wrong nodes and it can be occurred others nodes which have same cache. Therefore, it is necessary to solve the problems of existing method that are using unbalanced resource of replica and increasing network cost by cache misses. In this paper, cache management method for query forwarding optimization is proposed. The proposed method manages caches through cache manager. To optimize query forwarding, the cache manager makes caching data from lower loaded replicated node.

공간 데이터베이스에서 확장된 R-Tree를 이용한 효율적인 공간 질의 처리

서윤석 김천과학대학 2004 김천과학대학 논문집 Vol.30 No.-

R-Tree provides indirect access path to spatial object by using MBR(Minimum Boundary Rectangle). Various kind of object approximation method has been proposed, but most of them has low filtering performance. MBR decomposition methods has been proposed to upgrade filtering performance but it has disadvantage when object is very complex because it require large size of additional space to store decomposed MBR. Another solution to solve low performance of filter step in R-Tree is object decomposition method. It has good filtering performance but when information on original object is needed, object has to be reconstructed. In this thesis, we proposed extended R-Tree which has grid for secondary filter. Girds consist of cells which store information on original object. Each cells represents whether any part of original object is existed in cell boundary or not. Proposed method requires relatively small amount of space, and it provides easy way of inspection.

경남 고성군 덕명리 상족암지역의 야외지질학습자료 개발 및 활용에 관한 연구

서석근,윤성효 부산대학교 사범대학 과학교육연구소 2001 科學敎育硏究報 Vol.28 No.-

In the recent years, the importance of experience learning has been emphasized in the science education. Because of this situation, the science education that was mainly taught in the class has been changed into the field work. Therefore, the related teachers have recognized the systematic necessities of teaching materials that will be focused on the teaching places and activities. This study seeks to develop the study materials for the field geologic practice in the Snagjok-am, Deokmyeong-ri, Goseong-gun, Gyeonsangname-do, and to find the teaching methods for the geologic units of the earth science at the middle school. There are wide outcrop of sedimentary rocks which eroded by the sea waves in this place. And we have easily access to that place, so the field observation can be carried out successfully. Also there are various rocks, geologic structures, and fossils which are the importance materials for the science curriculum at the middle school. The practice course is divided into from A to E courses, and the related materials are made for the purpose of investigating those whole sites within one or two days. Each course can be explained as the followings. (1) Course A: participants can study from three stops the joint system of igneous rocks, the bedding layer of the sedimentary rocks, and the various characteristics of the shore sediments. (2) Course B: participants can investigate from three stops the structure of the sedimentary rocks, that is cross bedding, sun cracks and fossils. (3) Course C: participants can survey from two stops the various rock facies and geologic structure caused from the intrusion of igneous rocks. (4) Course D: in this course, students can observe the various aspects spontaneously because the previously stated geologic structures are repeatedly appeared. (5) Course E: participants can study the wave0cut bench, cliffs, and caves caused by the erosion of sea waves. This thesis seeks to develop the geologic informations, learning content, instructive and teaching methods, background knowledge, and the materials of field studies which students can effectively used. The content of field studies have focus on the geologic unit at the middle school science textbook, but this can be varied flexibly according to the related levels. Additionally, this study has been proven practically through the real experiments conducted by the first class student of the middle school. The conclusion is that the field programs have had the affirmative result in improving the scientific attitudes, and the cognition about field works has been appraised positively.

완전 직장탈 환자에서 변실금에 영향을 미치는 인자

윤서구,이광렬,김건욱,송석규,김칠석,이종균,김광연 대한대장항문학회 2001 Annals of Coloproctolgy Vol.17 No.1

u-GIS 환경에서 지오센서 데이터 스트림의 효과적인 처리를 위한 GS-DSMS의 설계

서윤석 김천과학대학 2011 김천과학대학 논문집 Vol.37 No.-

In u-GIS environments, GeoSensor generates sensor data streams including spatial information as well as various conventional sensor data from RFID, WSN, Web CAM, Digital Camera, CCTV, and Telematics units. This GeoSensor enables the revitalization of various ubiquitous USN technologies and services on geographic information. In order to service the u-GIS applications based on GeoSensors, it is indispensable to efficiently process sensor data streams from GeoSensors of a wide area. In this paper, we propose a GeoSensor data stream processing system for u-GIS computing over real-time stream data from GeoSensors with geographic information. The proposed system provides efficient gathering, storing, and continuous query processing of GeoSensor data stream, and also makes it possible to develop diverse u-GIS applications meet each user requirements effectively.

실시간 공간 데이터베이스 시스템을 위한 질의 최적화 기법

서윤석 김천과학대학 2003 김천과학대학 논문집 Vol.29 No.-

Real-time spatial database application systems require that spatial data have to be updated within valid time and user queries should be processed in real-time. In these systems, it needs to be considered a processing about real-time spatial data and real-time spatial query they are not considered in a conventional spatial database application systems. Real-time spatial queries in real-time spatial database application systems are hard to be processed successfully, because spatial operation takes major time in total processing and its real-time spatial data are easy to miss their validity. Therefore, it is required a query processing technique that makes queries meet time constraints of real-time spatial query with keeping validity of real-time spatial data. real-time operation post-placing technique is proposed in order to meet time constraints of real-time data and queries in real-time spatial query processing with managing real-tome spatial data and considering that manages real-time spatial data used in real-time spatial query.

그리드 데이터베이스에서 동적 계층 구조를 이용한 부하 분산 기법

서윤석 김천과학대학 2009 김천과학대학 논문집 Vol.35 No.-

This paper suggests a reallocation method based on dynamic hierarchical structure to solve the problems with reallocation in the proximity The method suggested in this study dynamically creates reallocation manager that collects information of each database at the time of reallocation in a logical way. In addition, by forming reallocation manager on the basis of hierarchical structure, it supports stepwise dispatch of information and reallocation algorithm, which, in turn, enables support of local reallocation algorithm and efficient balance adjustment. In this method, quicker processing is possible by distributing the burden of the uppermost reallocation manager to collect and analyze all the information to lower level reallocation manager using summarized information at the time of performing reallocation algorithm. This method is found to contribute to the increase in total processing volume after reallocation via performance evaluation.

상접한 공간 객체의 무결성 지원을 위한 공간 데이터베이스 트리거

서윤석 김천과학대학 2001 김천과학대학 논문집 Vol.27 No.-

공간데이터베이스 시스템에서 데이터베이스의, 일관성 유지를 위해 의미적 무결성을 지원해야 한다. 실세계의 경계 레이어에서 경계는 주위의 공간 객체들과 항상 접해 있어야만 하는 상접한 성질과 두개 이상의 다른 공간 객체가 동일한 이름을 가질 수 없는 성질을 가진다. 이 성질은 실세계에서 묵시적으로 인지되는 개념이다. 따라서 공간객체의 갱신으로 인해 레이어에 대한 묵시적인 개념이 위배될 경우 무결성 유지가 필요하다. 본 논문에서는 이 레이어에 대한 공간 객체의 무결성을 유지하기 위한 공간 데이터베이스 트리거를 제안한다. In spatial database system, semantic integrity should be supported for maintaining the data consistency. In the real world, spatial objects in boundary layer should always meet with neighbor objects, and they cannot hold the same name. This characteristic is an implied concept in real world. So, when this characteristic is disobeyed due to the update operations of spatial objects, it is necessary to maintain the integrity for a layer. In this thesis, we propose a spatial database trigger for supporting the integrity of spatial objects.

공간 객체의 효율적 중복영역 제거기법

서윤석 김천과학대학 2002 김천과학대학 논문집 Vol.28 No.-

클라이언트-서버 환경의 공간 데이터베이스 시스템은 방대한 양의 공간 데이터 전송에 따르는 네트워크 부하가 발생한다. 이러한 환경에서 화면 이동, 확대 및 축소 등의 유사한 영역의 데이터를 요구하는 질의는 매우 빈번하게 발생하며, 이미 전송된 영역과 중복되는 영역의 데이터를 재전송하여 네트워크부하를 가중시킨다. 이러한 문제는 생성된 질의 결과 중 클라이언트에 이미 전송된 데이터들을 제거함으로써 해결이 가능하다. 본 논문에서는 클라이언트-서버 공간데이터베이스 시스템에서 영역 요구 질의의 효율적인 처리 방법을 제안하고, 이를 기반으로 동일한 데이터의 중복 전송을 제거하기 위한 공간객체관리자를 설계하고 구현한다. Spatial Database systems in client-server environment have network overhead caused by transmission of a large amount of spatial data. In this environment, queries such as screen movement, enlargement, or shrinkage which request data in similar region are frequently occurred, and they increase network overhead by re-transmission the same data in duplicate region with earlier transmitted region. Removing transmitted data from query results can solve this problem. In this paper, we propose an efficient method for region request query in client-server spatial database systems, and design and implement a spatial object manager for removing re-transmission of the same data.