• Proceedings of the Korea Contents Association Conference
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• 2018.05a
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• pp.401-402
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• 2018

콘텐츠 큐레이션 서비스를 위해서 대용량 데이터를 학습하는 과정에서 발생하는 메모리부족 문제, 학습소요시간 문제 등을 해결하기 위한 "대용량 문서학습을 위한 동적학습 파이프라인 생성기술 중 빅데이터 마이닝을 위한 점진적 학습 모델" 기술이 필요하며, 본 논문에서 제안한 콘텐츠 큐레이션 서비스는 온라인상의 수많은 콘텐츠들 중 개인의 주관이나 관점에 따라 관련 콘텐츠들을 수집, 정리하고 편집하여 이용자와 관련이 있거나 좋아할 만한 콘텐츠를 제공하는 서비스이다. 본 논문에서 설계된 모아 큐레이션 서비스는 대용량의 문서를 학습함에 있어서 메모리 부족 문제, 학습 소요시간 문제 등을 해결하기 위해 학습데이터의 용량 제한이 없는 문서를 자유롭게 학습하고 부분적인 자질추가/변경 시에 변경요소만을 추가 반영할 수 있는 범용적이고 일반적인 분류기의 구조설계 방법 등을 제시하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04b
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• pp.112-114
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• 2004

무선 통신 기술의 발달로 인하여 LBS(Location Based System)와 같은 새로운 이동체 관련 서비스가 생겨나고 있다. 위치 기반 서비스에서 클라이언트인 이동체들이 주기적으로 보고하는 위치 데이터를 실시간으로 처리하기 위해 서버에서는 메인 메모리 DBMS를 유지하는 것이 필요한데, 데이터의 양이 계속적으로 증가하는 특성으로 인해 메인 메모리의 공간이 부족할 때 데이터를 디스크로 옮기는 시스템 설계가 필요하다. 그러나 기존의 연구는 대용량 이동체 환경에서의 색인 이주를 위한 노드 선택 정책과 이주를 위해 선택된 노드들의 디스크 배치 정책을 통합하여 나타내지 못하였다. 그러므로 대용량 이동체 데이터베이스 시스템 환경에 적합한 이주 정책들에 대한 연구가 필요하다. 이 논문에서는 대용량 이동체 데이터베이스 환경을 고려한 노드 선택 정책과 디스크 배치 정책을 분류하고 새로운 이주 정 책을 제시한다. 노드 선택 정책으로는 질의 성능을 위해서 캐쉬의 LRU(Least Recently Used) 정책을 이용한 변형된 LRU정책을 제시하고, 삽입 우선 정책으로는 이동체 색인인 R-tree의 삽입 알고리즘을 역이용한 정책을 제시한다. 또한 이주되는 노드들에 대한 디스크 페이지 배치가 시스템의 질의 성능에 영향을 미치므로 이를 고려한 디스크 배치 정책을 제시한다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.1
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• pp.87-93
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• 2010

RS(10,8) Code by 4-bit symbol was developed to protect the mass memory of STSAT-3 from SEU in orbit. Therefore, one symbol can be corrected for 32-bit data with 8-bit parity configuration. Moreover, scrubbing period and SEU occurrence rate was calculated based on the KITSAT-3 result. A prediction of SEU rates was performed based on the ground experiment results with a proton accelerator in the KIRAMS(Korea Institute of Radiological Medical Sciences).

• Proceedings of the Korea Information Processing Society Conference
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• 2005.11a
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• pp.1395-1398
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• 2005

볼륨 렌더링은 3차원이나 그 이상의 차원의 볼륨 데이터에서 의미있는 정보를 추출해 내어 직관적으로 표출하는 가시화 기법을 말하며 의료영상, 기상학, 유체역학 등 다양한 분야에서 널리 사용되고 있다. 한편, 최근 PC 하드웨어의 급격한 발전으로 과거에는 슈퍼컴퓨터에서나 가능했던 대용량 볼륨 데이터의 가시화가 일반 PC 환경에서도 가능하게 되었다. GPU의 꼭지점 및 픽셀 쉐이더의 수치 계산에 최적화된 벡터 연산으로 빠른 볼륨 가시화를 가능하게 한 것이다. 그러나 GPU의 메모리 용량의 한계로 대용량의 볼륨 데이터를 빠르게 가시화하는 것은 지금까지 어려운 문제로 남아있다. 본 논문에서는 GPU의 텍스쳐 메모리 크기보다 큰 볼륨 데이터를 여러 개의 GPU 메모리에 분산시키고 이를 꼭지점 및 픽셀 쉐이더를 이용하여 빠르게 렌더링하여 타일형 디스플레이에서 고해상도로 가시화하는 시스템을 디자인하고 구현하고자 하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.1
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• pp.41-48
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• 2013

The aim of the present study is to design a memory-efficient octree for querying large 3D point cloud. The aim has been fulfilled by omitting variables for minimum bounding hexahedral (MBH) of each octree node expressed in C++ language and by passing the re-estimated MBH from parent nodes to child nodes. More efficiency has been reported by two-fold processes of generating pseudo and regular trees to declare an array for all anticipated nodes, instead of using new operator to declare each child node. Experiments were conducted by constructing tree structures and querying neighbor points out of real point cloud composed of more than 18 million points. Compared with conventional methods using MBH information defined in each node, the suggested methods have proved themselves, in spite of existing trade-off between speed and memory efficiency, to be more memory-efficient than the comparative ones and to be practical alternatives applicable to large 3D point cloud.

• Journal of Convergence for Information Technology
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• v.11 no.11
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• pp.44-50
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• 2021

Recently, enterprise storage systems that require large-capacity storage devices to accommodate big data have used large-capacity flash memory-based storage devices with high density compared to cost and size. This paper proposes a high-efficiency life prediction method with slope descent to maximize the life of flash memory media that directly affects the reliability and usability of large enterprise storage devices. To this end, this paper proposes the structure of a matrix for storing metadata for learning the frequency of defects and proposes a cost model using metadata. It also proposes a life expectancy prediction policy in exceptional situations when defects outside the learned range occur. Lastly, it was verified through simulation that a method proposed by this paper can maximize its life compared to a life prediction method based on the fixed number of times and the life prediction method based on the remaining ratio of spare blocks, which has been used to predict the life of flash memory.

• Journal of the Korea Society of Computer and Information
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• v.27 no.7
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• pp.1-7
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• 2022

Recently, as the use of applications such as big data programs and machine learning programs that are driven while generating large amounts of data in the program itself becomes common, the existing main memory alone lacks memory, making it difficult to execute the program quickly. In particular, the need to derive results more quickly has emerged in a situation where it is necessary to analyze whether the entire sequence is genetically altered due to the outbreak of the coronavirus. As a result of measuring performance by applying large-capacity data to a computing system equipped with a self-developed memory pool MOCA host adapter instead of processing large-capacity data from an existing SSD, performance improved by 16% compared to the existing SSD system. In addition, in various other benchmark tests, IO performance was 92.8%, 80.6%, and 32.8% faster than SSD in computing systems equipped with memory pool MOCA host adapters such as SortSampleBam, ApplyBQSR, and GatherBamFiles by task of workflow. When analyzing large amounts of data, such as electrical dielectric pipeline analysis, it is judged that the measurement delay occurring at runtime can be reduced in the computing system equipped with the memory pool MOCA host adapter developed in this research.

• Journal of Korea Spatial Information System Society
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• v.10 no.2
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• pp.1-12
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• 2008

Automatic semiconductor manufacture system generating transaction from 50,000 to 500,000 per a second needs storage management system processing very large data at once. A lot of storage management systems are researched for storing very large data. Existing storage management system is typical DBMS on a disk. It is difficult that the DBMS on a disk processes the 500,000 number of insert transaction per a second. So, the DBMS on main memory appeared to use memory. But it is difficultthat very large data stores into the DBMS on a memory because of limited amount of memory. In this paper we propose storage management system using insert transaction of a block unit that can process insert transaction over 50,000 and store data on low storage cost. A transaction of a block unit can decrease cost for a log and index per each tuple as transforming a transaction of a tuple unit to a block unit. Besides, the proposed system come cost to decompress all block of data because the information of each field be loss. To solve the problems, the proposed system generates the index of each compressed block to prevent reducing speed for searching. The proposed system can store very large data generated in semiconductor system and reduce storage cost.

• The Journal of the Korea Contents Association
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• v.22 no.8
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• pp.81-93
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• 2022

Recently, research on processing a large-capacity graph using GPUs has been conducting. In order to process a large-capacity graph in a GPU with limited memory, the graph must be divided into subgraphs and then processed by scheduling subgraphs. In this paper, we propose an efficient graph algorithm processing scheme in GPU environments with limited memory and performance evaluation. The proposed scheme consists of a graph differential subgraph scheduling method and a graph segmentation method. The bulk graph segmentation method determines how a large-capacity graph can be segmented into subgraphs so that it can be processed efficiently by the GPU. The differential subgraph scheduling method schedule subgraphs processed by GPUs to reduce redundant transmission of the repeatedly used data between HOST-GPUs. It shows the superiority of the proposed scheme by performing various performance evaluations.

• The Magazine of the IEIE
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• v.22 no.12
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• pp.46-56
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• 1995