• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.37
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• pp.241-249
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• 1996

In this paper, a 0-1 integer programming model for solving vertical partitioning problem minimizing the number of disk accesses is formulated and a branch-and-bound method is used to solve the binary vertical partitioning problem. In relational databases, the number of disk accesses depends on the amount of data transferred from disk to main memory for processing the transactions. Vertical partitioning of the relation can often result in a decrease in the number of disk accesses, since not all attributes in a tuple are required by each transactions. The algorithm is illustrated with numerical examples and is shown to be computationally efficient. Numerical experiments reveal that the proposed method is more effective in reducing access costs than the existing algorithms.

• Proceedings of the Korea Database Society Conference
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• 2001.06a
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• pp.311-322
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• 2001

대부분의 일반 정보 검색 시스템은 색인어를 통해 이루어지는데 이런 경우 사용자는 원하는 정보를 얻기 위해 데이터베이스에 저장된 색인어를 정확하게 입력해야 한다. 그러나 일반 사용자가 필요한 색인어를 정확하게 입력하기는 어렵고 특히 원하는 정보가 전문분야의 것일 때는 더욱 그러하다. 따라서 특정 분야의 용어들을 중심으로 전문용어를 관리할 수 있는 시스템의 개발이 요구되고 있다. 정보기술 분야도 빠르게 성장하고 있는 전문분야의 하나로 사용되는 대부분의 단어가 영어이고 한글 표기 또한 다양하여 많은 사용자들이 원하는 정보를 정확하게 찾지 못하고 있다. 이렇듯 단어간의 형태적인 불일치로 인해 생기는 정보 검색의 문제를 해결하고 검색어의 범위를 확장하기 위해 만든 것이 전문용어 검색 시스템이다. 정보 검색시 사용자가 입력한 검색어뿐만 아니라 동의어나 상위어, 하위어까지 검색하여 질의를 확장함으로써 검색 효율을 높일 수 있다. 또한 객체-관계형 데이터베이스로 설계하여 검색이 용이하고, 새로운 단어의 확장이 용이하도록 그 구조를 설계하였다. 제안한 시스템은 메인 메모리 DBMS 를 이용하여 전자상거래와 같이 많은 사용자들이 동시에 접근하는 환경에서도 빠른 검색 성능을 유지할 수 있도록 하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04b
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• pp.40-42
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• 2001

트랜잭션 로그 정보를 안전한 저장장치에 저장하는 것은 트랜잭션의 완료를 위한 필수 불가결한 요소이지만 시스템 성능에 커다란 저해 요인이 되고 있다. 이에 대한 개선책으로 선-완료(pre-commit), 그룹 완료(group commit)와 같은 방식들의 제안이 있었으나, 이 방식들을 시스템에 적용했을 경우, 특히 로깅이 평상시 트랜잭션 수행시간의 거의 대부분을 차지하는 메인 메모리 데이터베이스(MMDB) 시스템과 같은 환경에서의 구체적이고 다양한 논의가 아직 이루어지지 안고 있다. 본 논문에서는 MMDB시스템에 그를 완료를 적용할 때 발생할 수 있는 교착 상태에 대한 설명과 해결책을 제시하였고, 다각적인 모의실험을 실시하여 이전 논문들의 우려와는 달리 그룹 완료 방식이 전체 시 9853;메 성능뿐만 아니라 트랜잭션 수행시간 단축을 위해서도 매우 우수한 해결 방식이며, 선-완료 방식은 예상과 달리 그룹 완료 방식의 보조수단으로 병행될 때에만 시스템 성능에 추가적인 도움을 준다는 것을 보였다.다.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10b
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• pp.208-210
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• 1998

시간제약조건을 가지는 실시간 데이터베이스 시스템은 실시간 고성능을 위하여 빠른 데이터 접근과 균일한 성능 분포를 요하는 특성을 가진다. 이를 위해 데이터베이스 전체를 주기억장치에 상주시키는 주기억장치 상주형 실시간 데이터베이스 시스템에 대한 연구가 혹 넓게 진행되고 있다. 본 논문에서는 국내에서 개발중인 주기억장치 상주형 실시간 데이터베이스 시스템 Mr.RT 2.5의 클라이언트-서버간의 통신 부하를 줄일 수 있는 Mr.RT 3.0의 클라이언트-서버 구조를 제시한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.10
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• pp.2701-2717
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• 2023

In this paper, a hybrid fuzzy-based method is suggested for determining India's best system for power generation. This suggested approach was created using a fuzzy-based combination of the Giza Pyramids Construction (GPC) and Recalling-Enhanced Recurrent Neural Network (RERNN). GPC is a meta-heuristic algorithm that deals with solutions for many groups of problems, whereas RERNN has selective memory properties. The evaluation of the current load requirements and production profile information system is the main objective of the suggested method. The Central Electricity Authority database, the Indian National Load Dispatch Centre, regional load dispatching centers, and annual reports of India were some of the sources used to compile the data regarding profiles of electricity loads, capacity factors, power plant generation, and transmission limits. The RERNN approach makes advantage of the ability to analyze the ideal power generation from energy data, however the optimization of RERNN factor necessitates the employment of a GPC technique. The proposed method was tested using MATLAB, and the findings indicate that it is effective in terms of accuracy, feasibility, and computing efficiency. The suggested hybrid system outperformed conventional models, achieving the top result of 93% accuracy with a shorter computation time of 6814 seconds.

• The KIPS Transactions:PartA
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• v.17A no.4
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• pp.181-188
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• 2010

In this study, we suggest the system to analyze network users' action patterns by using Data-Mining Technique. We installed Network Tap to implement the analysis system of network action and copied the network packet. The copied packet is stored at the database through MainMemoryDB(MMDB) of the high-speed. The stored data analyze the users' action patterns by using Data-Mining Technique and then report the results to the network manager on real-time. Also, we applied the standard XML document exchange method to share the data between different systems. We propose this action pattern analysis system operated embedded type of SetToBox to install easily and support low price.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.8
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• pp.807-815
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• 2008

In this paper, design, development and evaluation of DIP(Database Interface Program) are presented. The main purpose of this study is to improve the simulation quality to get more realistic response of target system. The designed and developed major function is composed of flexible memory structure, efficient arithmetic database language and high speed interpolation/extrapolation algorithm. To evaluate the operation speed and accuracy of returned data, trim simulation is performed based on in-house software and, DIP is applied to existing real-time simulator such as engineering HQS(Handling Quality Simulator) to evaluate reliability and performance. The result of evlaution reveals that calculation speed and data accuracy are satisfied, and flight performance is satisfied in the real-time simulator environments.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.11
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• pp.2080-2085
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• 2008

KEPCO's AMR (Automatic Meter Reading) is a system that performs the real-time inspection and management of the 15-minute load profile of electric power consumption through a wired and/or wireless network such as CDMA. It has been utilized widely for real-time collection and data analysis. So far, KEPCO has focused on establishing wireless networks using CDMA and collecting data in real time but failed to consider sufficiently performances that can improve the quality of the original data required in terms of data utilization as well as establish the summary information. In this paper, we are going to show the functions that improve data quality by recording the final renewal time of any erroneous data and maintaining such data lists to use them in the rebuilding of summary information. The goals are to reduce any load applied mainly on the DBMS (Database Management System) of AMR, to enable the real-time performance of establishment in the summary information, and to obtain high-quality inspection data. The performance evaluation result has revealed a 10-fold improvement compared to the traditional disk-based DBMS system when the summary information is established.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.2
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• pp.365-375
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• 2019

A PLC (Programmable Logic Controller) is a highly-reliable industrial digital computer which supports real-time embedded control applications for safety-critical control systems. Real-time operating systems such as uC/OS have been used for PLCs and must meet real-time constraints. As PLCs have been widely used for industrial control systems and connected to the Internet, they have been becoming a main target of cyberattacks. In this paper, we propose an execution code sanitizer to enhance the security of PLC systems. The proposed sanitizer analyzes PLC programs developed by an IDE before downloading the program to a target PLC, and mitigates security vulnerabilities of the program. Our sanitizer can detect vulnerable function calls and illegal memory accesses in development of PLC programs using a database of vulnerable functions as well as the other database of code patterns related to pointer misuses. Based on these DBs, it detects and removes abnormal use patterns of pointer variables and existence of vulnerable functions shown in the call graph of the target executable code. We have implemented the proposed technique and verified its effectiveness through experiments.

• Journal of Biomedical Engineering Research
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• v.15 no.3
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• pp.333-340
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• 1994

Laboratory information system (LIS) is a key tool to manage laboratory data in clinical pathology. Our department has developed an information system for routine hematology using down-sized computer system. We have used an IBM 486 compatible PC with 16 MB main memory, 210 MB hard disk drive, 9 RS-232C port and 24 pin dot printer The operating system and database management system were SCO UNIX and SCO foxbase, respectively. For program development, we used Xbase language provided by SCO foxbase. The C language was used for interface purpose. To make the system use friendly, pull-down menu was used. The system connected to our hospital information system via application program interface (API), so the information related to patient and request details is automatically transmitted to our computer. Our system interfaced with two complete blood count analyzers (Sysmex WE-8000 and Coulter STKS) for unidirectional data transmission from analyzer to computer. The authors suggests that this system based on down-sized computer could provide a progressive approach to total LIS based on local area network, and the implemented system could serve as a model for other hospital's LIS for routine hematology.