• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.4997-5006
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• 2010

A flash-memory-based SSDs(Solid State Disks) are one of the best media to support portable and desktop computers' storage devices. Their features include non-volatility, low power consumption, and fast access time for read operations, which are sufficient to present flash memories as major database storage components for desktop and server computers. However, we need to improve traditional storage management schemes based on HDD(Hard Disk Drive) and RAID(Redundant array of independent disks) due to the relatively slow or freezing characteristics of write operations of SSDs, as compared to fast read operations. In order to achieve this goal, we propose a new storage management scheme called Hetero-Mirroring based on traditional HDD mirroring scheme. Hetero-Mirroring-based scheme improves RAID-1 operation performance by balancing write-workloads and delaying write operations to avoid SSD freezing. Our test results show that our scheme significantly reduces the write operation overheads and freezing overheads, and improves the performance of traditional SSD-RAID-1 scheme by 18 percent, and the response time of the scheme by 38 percent.

• Journal of Convergence Society for SMB
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• v.6 no.3
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• pp.7-12
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• 2016

This paper aims to examine the adoption of several management tools & techniques(MT&T) by the Strong Small Business Enterprises (SSBE) in Korea, In addition, the paper examines the impact of the adopted MT&T techniques on a company's overall performance. The paper used a questionnaires survey method to gather the required data. The paper used descriptive statistics, correlation and regression techniques to analyze the data. The paper found that benchmarking, BSC, IMS and TQM are among the MT&T techniques widely adopted by SSBE. In addition, the paper found that the adoption of MT&T techniques significantly influenced the companies' overall performance. More specifically, the paper found that the adoption of BSC significantly influenced that the companies' profitability, customer satisfaction, market position and sales growth for exisiting services and products. The findings this paper provide could be considered important and useful for advancement of companies adopting MT&T techniques to improve their performance.

• Journal of KIISE:Computer Systems and Theory
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• v.37 no.5
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• pp.285-291
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• 2010

Flash memory has many good features such as small size, shock-resistance, and low power consumption, but the cost of flash memory is still high to substitute for hard disk entirely. Recently, some mobile devices, such as laptops, attempt to use both flash memory and hard disk together for taking advantages of merits of them. However, existing OSs (Operating Systems) are not optimized to use the heterogeneous storage media. This paper presents a new buffer cache management scheme. First, we allocate buffer cache space according to access patterns of block references and the characteristics of storage media. Second, we prefetch data blocks selectively according to the location of them and access patterns of them. Third, we moves destaged data from buffer cache to hard disk or flash memory considering the access patterns of block references. Trace-driven simulation shows that the proposed schemes enhance the buffer cache hit ratio by up to 29.9% and reduce the total I/O elapsed time by up to 49.5%.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.411-411
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• 2015

유량예측의 가장 주된 목적은 가뭄과 홍수와 같은 수해방지를 위해 통합수자원관리를 수행하는데 있다. 이런 유량예측을 위해 다양한 기법들로 예측이 수행되고 있으며, 예측기간과 필요 정확도에 따라 초단기, 단기, 중 장기 예측 등으로 구분할 수 있다. 유량예측에 사용되는 기법들은 기후변화 시나리오와 같이 예측된 강우자료를 이용하여 유출량을 예측하는 방법이 있으며, 통계적인 방법으로 과거자료들을 활용하여 미래의 유량을 예측하는 방법이 있다. 본 연구에서는 ESP 기법을 이용하여 금호강 유역의 월 단위(30일) 유량을 예측하고자 한다. 앙상블 유량예측기법(ESP; Ensemble Streamflow Prediction)이란 현재의 유역상태를 초기조건으로 사용하고 과거의 온도나 강수 등의 시계열 앙상블을 강우-유출모형에 입력하여 유출량을 앙상블로 예측하는 기법이다. ESP는 결국 현재의 유역상태와 유역에서의 과거 강우 관측기록, 미래 강우예측에 대한 정보를 조합하여 그에 따른 유출 앙상블을 생산해내게 된다. 월 유량을 예측하기 위해서 금호강 유역의 1988년에서 2014년까지 27년간 대구, 영천, 포항 관측소의 기상자료를 수집하였으며, 금호강 표준유역에 해당하는 19개 유역으로 분할하여 모의에 이용하였다. 금호강 유역에 티센망을 적용하여 각 표준유역별로 강우량을 조합하여 2013년까지 모의에 적용하였으며, 이는 과거자료로 사용하였다. 유량예측에 사용되는 강우자료를 생성하기 위해서 26년간 일강우를 이용하였다. 예를 들어 2014년 12월을 예측한다면 11월까지 관측된 유역초기 조건을 가지는 수문모형의 12월 기상입력자료로써 현재 유역에서 발생 가능성이 있는 동일 유역의 과거 1988년부터 2013년까지의 12월 기상자료들을 사용하는 방법이다. 1988년부터 2013년까지 26개 12월 기상자료를 사용하므로 유량예측결과 또한 26개가 주워진다. 계산된 26개의 유량앙상블이 적용된 유역에서 12월에 발생 가능한 유출량의 모음이 된다. 시나리오결과를 수자원관리에 활용하기 위해서 초과확률로 분석하였으며, 이런 분석의 결과는 향후 가뭄과 홍수 같은 수해방지를 위해 수공구조물의 운영에도 활용할 수 있을 것으로 판단된다.

• Korean Journal of Construction Engineering and Management
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• v.17 no.6
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• pp.13-23
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• 2016

Construction automation based on information and communication technology(ICT) has been studied for improving productivity in the construction industry. This study investigates domestic research trends in ICT-based construction automation using text mining techniques. The results show that 'Technology to collect and analyze project progress(26%)' and 'Technology to analyze and apply the automation element of construction machinery(28%)' are the major research area. The word of 'construction information' is showed as important keywords in the area of 'Technology to collect and analyze project progress', and researches focusing on resource management, site management, information management, and real-time information monitoring have been mainly conducted. The word of 'ubiquitous' is shown as important keywords in the area of 'Technology to analyze and apply the automation element of construction machinery', and researches focusing on ubiquitous information management, ubiquitous site management, and measurement system have been mainly conducted.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.18-19
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• 2016

At Present, Korea government run the 38 points manned lighthouse, the change of Manned lighthouse that manager live is inevitable in orger to enhanced features as aids to navigation and provide a fore efficient management system. There are "Enhancing management system for Manned Lighthouses" four standards(Function of AtoN, Functionality of wide area management, National policy, Marine culture) for evaluation of Unmanned Lighthouses. After collecting these datas, analyzing it, applying AHP and Likert Scale, we choose base manned lighthouses for shorten restoration time that can manage AtoN far from regional office of Oceans & Fisheries. This paper will support efficient management system for AtoN that were scattered in sea of korea and improvement living environment for lighthouse keepers.

• Journal of the Korean Data and Information Science Society
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• v.26 no.3
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• pp.639-652
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• 2015

In today's manufacturing environment, the process data can be easily measured and transferred to a computer for analysis in a real-time mode. As a result, it is possible to monitor several correlated quality variables simultaneously. Various multivariate statistical process control (MSPC) procedures have been presented to detect an out-of-control event. Although the classical MSPC procedures give the out-of-control signal, it is difficult to determine which variable has caused the signal. In order to solve this problem, data mining and machine learning techniques can be considered. In this paper, we applied the technique of decision tree learning to the MSPC, and we did simulation for MSPC procedures to monitor the bivariate normal process means. The results of simulation show that the overall performance of the MSPC procedure using decision tree learning technique is similar for several values of correlation coefficient, and the accurate classification rates for out-of-control are different depending on the values of correlation coefficient and the shift magnitude. The introduced procedure has the advantage that it provides the information about assignable causes, which can be required by practitioners.

• The Journal of Society for e-Business Studies
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• v.12 no.3
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• pp.33-47
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• 2007

The requirements have been changed during development progresses, since it is impossible to define all of software requirements. These requirements change leads to mistakes because the developers cannot completely understand the software's structure and behavior, or they cannot discover all parts affected by a change. Requirement changes have to be managed and assessed to ensure that they are feasible, make economic sense and contribute to the business needs of the customer organization. We propose a feature-oriented requirements change management method to manage requirements change with value analysis and feature-oriented traceability links including intermediate catalysis using features. Our approach offers two contributions to the study of requirements change: (1) We define requirements change tree to make user requirements change request generalize by feature level. (2) We provide overall process such as change request normalization, change impact analysis, solution dealing with change request, change request implementation, change request evaluation. In addition, we especially present the results of a case study which is carried out in asset management portal system in details.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.189-193
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• 2011

유역관리 및 수질 향상을 위해 다양한 환경정책이 시행되고 있으며, 최근 수질오염총량관리제의 시행으로 인해 보다 집중적인 유역관리와 수질 향상을 위한 노력이 배가되고 있다. 이러한 노력의 일환으로 현재 환경부 국립환경과학원에서는 수질오염총량관리를 위하여 단위유역의 말단지점에서 수질 및 유량자료에 대한 정기적인 측정을 8일 간격으로 시행하고 있으며, 데이터 베이스 및 웹시스템을 통하여 자료를 공개하고 있다(이호열, 2009). 이와 같은 자료의 측정과 축적은 그 분석을 통해 수질 개선을 위한 우선 관리 대상지점의 파악 등과 같이 수질오염총량관리제의 시행과 평가를 위해 사용될 수 있을 뿐만 아니라 새로운 환경정책의 수립에도 활용될 수 있을 것으로 기대된다. 그러나 현재 소수의 연구들에서만 상기의 자료를 단순히 활용한 결과를 찾을 수 있으며, 특히 측정된 수질 및 유량자료를 분석하여 발표한 연구결과 역시 소수에 지나지 않는다(김철겸 등, 2009). 측정 자료에 대한 분석 및 이에 따른 자료의 활용성 제고를 위해서 다양한 자료 분석 기법의 개발과 적용이 절실하다. 이러한 자료 분석 기법의 개발 및 적용에 관한 연구의 일환으로 최근 패턴분류를 위해 다양한 분야에서 활용되고 있는 자기조직화 특성 지도(Self Organizing Feature Map: SOFM)를 상기의 측정 자료에 적용한 연구 결과가 보고된 바 있다(진영훈 등, 2009; 2010). 본 연구에서는 수질오염총량관리제를 위해 측정되고 있는 수질 및 유량자료를 수집하여 자료에 내재되어 있는 시 공간적 특성을 분석하고자 하였다. 영산강 유역을 대상으로 하여, 본 유역 내의 단위유역들 중 황룡_A, 지석_A, 영본_A, 영본_B, 영본_C, 영본_D의 말단지점에서 측정되고 있는 BOD (Biochemical Oxygen Demand), TOC (Total Organic Carbon), T-N (Total Nitrogen), T-P (Total Phosphorus), SS (Suspended Solids) 수질농도 및 유량자료를 대상으로 연구를 진행하였다.

• The Journal of the Korea Contents Association
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• v.19 no.1
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• pp.278-292
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• 2019

The purpose of this study is to provide a suggestion to improve speciality and job performance of social work case management using importance-performance-analysis(IPA). A quantitative research design was used and data were collected from 209 social workers who are in charge of case manager job at Ulsan metropolitan area. Study participants were asked the recognition of importance-job competence and need for supervision-experience of social work case management job description on the NCS(9 competency units, 33 competency units). Descriptive analysis and IPA were performed. This study found the need for intensified job competence of 'building external operating systems' and 'development of resource linkage systems'. Also, it is necessary to provide intensive supervision for 'building an external and internal operating system.' Based on the results, future direction of intensified job performance for socla work case management was discussed.