• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.3
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• pp.298-305
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• 2016

Various NoSQL databases are more excellent to process a large amount of big data than existing relational databases such as MySQL, PostgreSQL and Oracle. Among widely used NoSQL databases, performance of HBase, Cassandra, MongoDB and Redis was comparatively assessed. For distributed processing of a large amount of data, 12 servers were connected through switching hub and Ubuntu was installed as operating system. As for benchmark tool, YCSB was applied. Read and update ratios changed from 50% and 50%, 95% and 5% and finally, 100% and 0% and each of them was assessed as 200,000 commands developed into 1,200,000 commands for each case. Cassandra was most excellent with transaction processing per second while MongoDB was most excellent with the number of processes carried out per unit time.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.01a
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• pp.175-178
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• 2015

최근 모바일 장비 및 시스템의 발달로 위치정보와 이동 객체에 관련된 많은 서비스들이 연구되고 있다. 궤적은 이동 객체가 시간에 따라 변하는 위치정보들의 모음이다. 기존의 데이터베이스 시스템에서는 이동 객체 데이터 타입을 지원하지 않는다. 이 논문에서는 공간 데이터베이스로 많이 활용되고 있는 PostgreSQL/PostGIS 상에서 궤적 데이터의 연산 및 질의 처리가 가능한 확장형 모듈로써 PostTrajectory를 제안하고 있다. 또한, 궤적 데이터에 대한 다양한 질의 요구 조건들을 충족시킬 수 있는 함수들을 구현하여 궤적 데이터의 효율적인 질의 처리를 가능하게 하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.6
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• pp.645-651
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• 2019

At a time when large amounts of data are being poured out, there are many changes in software architecture or data storage patterns because of the nature of the data being written, rather more read-intensive than writing. Accordingly, in this paper, the query model of Command Query Responsibility Segmentation (CQRS) pattern separating the responsibilities of commands and queries is used to implement an efficient high-capacity data lookup system in users' requirements. This paper uses the 2018 temperature, humidity and precipitation data of the Korea Meteorological Administration Open API to store about 2.3 billion data suitable for RDBMS (PostgreSQL) and NoSQL (MongoDB). It also compares and analyzes the performance of systems with CQRS pattern applied from the perspective of the web server (Web Server) implemented and systems without CQRS pattern, the storage structure performance of each database, and the performance corresponding to the data processing characteristics.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04b
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• pp.160-162
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• 2002

SNP는 개인과 개인간의 DNA에 존재하는 한 염기 쌍의 차이(single base-pair variation)이다. SNP를 이용하면 사람마다 다른 유전병의 형태 등을 규명할 수 있다. 본 논문에서는 한국생명공학연구원의 유전체 사업단에서 개발해 오고 있는 웹기반 SNP데이터 검색 시스템의 설계와 구현에 대해서 설명한다. 본 시스템은 일반 속성(attribute)을 저장하고 검색하기 위해 PostgreSQL DBMS를 사용하고, DNA 시퀸스 검색을 위해 BLAST검색엔진을 사용한 약결합 아키텍쳐(loosely-coupled architecture)를 채택하고 있다. 즉, 일반 속성으로 저장될 수 있는 데이터들은 데이터베이스의 테이블들의 컬럼 값으로 저장하고 SQL 언어를 통해 검색할 수 있도록 하였으며, DNA 시퀸스 검색을 위해서는 BLAST에서 제공하는 인덱스를 구축하고 BLAST 명령어를 사용하여 검색할 수 있도록 하였다. 또한, 결과 분석 모듈을 구현하여 검색 결과들이 다른 웹 사이트의 데이터를 가리키도록 하였다.

• The KIPS Transactions:PartC
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• v.11C no.4
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• pp.545-554
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• 2004

WebDAV is a protocol to support collaboration among the workers in geographically distant locations through the Internet. WebDAV extends the web communication protocol HTTP/1.1 to provide a standard infrastructure for supporting asynchronous collaboration for various contents across the Internet. To provide the WebDAV functionality in legacy applications such as web-based collaborative systems or document management systems, those systems need to be implemented additionally to handle the WebDAV methods and headers information. In this paper, we developed an Apache-based WebDAV server, named DAVinci(WebDAV Is New Collaborative web-authoring Innovation)which supports the WebDAV specification. DAVinci was implemented as a form of service provider on a mod_dav Apache module. Mod_day, which is an Apache module, is an open source module to provide WebDAV capabilities in an Apache web server. We used a file system for storing resources and the PostgreSQL database for their properties. In addition, the system provides a consistency manager to guarantee that both resources and properties are maintained without inconsistency between resources and their properties.

• Spatial Information Research
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• v.19 no.1
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• pp.117-126
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• 2011

Recently, AR applications provide location-based spatial information by GPS. Also, the spatial information is displayed by the angle of the camera. So far, traditional spatial indexes in spatial database field retrieve and filter spatial information by the minimum bounding rectangle (MBR) algorithm.(ex. R-tree) MBR strategy is a useful technique in the geographic information systems and location based services. But MBR technique doesn't reflect the characteristics of spatial queries in AR. Spatial queries of AR applications have high possibility of the dead space area between MBRs of non-leaf node and query area. We propose triangle node filtering algorithm that improved efficiency of spatial retrieval used the triangle node filtering techniques by exclusion the dead space. In this paper, the proposed algorithm has been implemented on PostgreSQL/PostGIS. Experimental results show the spatial retrieval that using the proposed algorithm better performance than the spatial retrieval that of the minimum bounding rectangle algorithm.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.12
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• pp.429-436
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• 2022

Temporary files are generated when the Hash Join is performed on tables larger than the memory. During the join process, each temporary file is deleted sequentially after it completes the I/O operations. This paper reveals for that the fallocate system call and file deletion-related trim options significantly impact the hash join performance when temporary files are managed on SSDs rather than hard disks. The experiment was conducted on various commercial and research SSDs using PostgreSQL, a representative open-source database. We find that it is possible to improve the join performance up to 3 to 5 times compared to the default combination depending on whether fallocate and trim options are used for temporary files. In addition, we investigate the write amplification and trim command overhead in the SSD according to the combination of the two options for temporary files.

• Journal of the Korea Society of Computer and Information
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• v.29 no.6
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• pp.39-51
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• 2024

This paper proposes a novel approach to enhance the security of container-based systems by analyzing system calls to dynamically detect race conditions without modifying the kernel. Container escape attacks allow attackers to break out of a container's isolation and access other systems, utilizing vulnerabilities such as race conditions that can occur in parallel computing environments. To effectively detect and defend against such attacks, this study utilizes eBPF to observe system call patterns during attack attempts and employs a AdaBoost model to detect them. For this purpose, system calls invoked during the attacks such as Dirty COW and Dirty Cred from popular applications such as MongoDB, PostgreSQL, and Redis, were used as training data. The experimental results show that this method achieved a precision of 99.55%, a recall of 99.68%, and an F1-score of 99.62%, with the system overhead of 8%.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.808-810
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• 2005

본 논문은 공개소스 기반의 WAS 구성의 핵심인 Tomcat, JBoss, PostgreSQL, Apache 등을 한국형 공개SW 표준 플랫폼 BOOYO 상에 효과적으로 탑재하고 SPECjAppServer2004 벤치마크를 실시하여 외산 제품과 성능을 비교 한다. 벤치마크 결과 부하가 증가할수록 성능 측정단위인 JOPS가 기존의 공개SW플랫폼에 비하여 현저히 덜 하락하는 결과를 보이며 비교적 우수한 결과를 나타내었다. 본 논문에서는 이러한 벤치마크를 실시하기 위하여 구축한 시험용 WAS의 구성 내용과 아울러 그 결과를 보다 상세히 기술한다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.1
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• pp.63-71
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• 2017

Recently, there has been growing interest in public participation GIS (Geographic Information System) technology that enables spontaneous public response to increasingly frequent flood and drought events. Accordingly, social and economic demands are increasing on portal services that are designed to help cope with natural hazards such as earthquakes. By focusing on a specific hazard, urban flood, this study designed a prototype of a disaster response portal and its service system. The community map developed in this study is focused on prevention and mitigation of the urban flood damage by analyzing the vulnerable areas, and providing effective means to inspect the roads and sewer systems. By considering the compatibility with VGI (Volunteered Geographic Information) portals, the study created a system environment by employing universally used open-source software programs such as Apache Tomcat, GeoServer, GeoNetwork, and PostgreSQL/PostGIS.