• 정보보호학회논문지
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• 제21권1호
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• pp.125-133
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• 2011

최근 들어, 모바일 단말의 폭발적인 보급 더불어 단말 내의 중요정보가 외부 저장 매체로 불법적으로 유출되는 보안 위협이 증가되고 있다. 따라서, 본 논문에서는 단말 내 중요정보의 외부 저장 매체로의 유출 방지 기법을 설계 및 구현한다. 이 기법은 파일의 임의위치에서 시그니처를 샘플링하고 이를 이용하여 유출 탐지, 차단 기능을 수행한다. 시그니처 샘플링 과정은 대상 파일을 일정 크기의 추출 윈도우로 구분한 후 이 영역 내에서 임의의 위치에서 1개 이상의 시그니처를 추출한다. 그리고, 가장 효과적인 샘플링을 수행하기 위하여 전체 샘플링, 이항분포 샘플링, 동적 샘플링의 다양한 추출 방식을 구현 및 시뮬레이션을 수행 한다. 제안된 기법은 파일의 임의 위치에서 시그니처를 샘플링하여 공격자의 시그니처 예측성을 낮출 수 있고 원본 데이터에 대한 변형 없이 유출 방지기능을 효과적으로 구현할 수 있다는 장점을 가진다. 따라서, 사용자 편의성이 중시되고 비교적 저 사양의 시스템인 모바일 단말에서 효과적으로 유출방지 기능을 구현할 수 있는 기법이다.

• Journal of Korean Vacuum Science & Technology
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• 제3권2호
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• pp.107-111
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• 1999

We developed the experimental function (ERF) which can be used for the numerical curve fitting analysis in photoelectron spectroscopy (PES). We selected the core-levels of Ag 3d5/2 and Au 4f7/2 to obtain the ERF from the measured core-level spectra. For the numerical fourier transformation we applied the fast transform (FFT) algorithm. we considered optical (Wiener) filtering with the FFT due to noise and used Hann window function to remedy the information leakage in frequency domain due to discrete and finite sampling of measurement. The comparison of the curve fitting results using the ERF obtained in this work and the mathematical response function with a gaussian in the conventional approach shows clearly the improvement of the curve fitting analysis.

• Journal of Power Electronics
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• 제12권3호
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• pp.509-517
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• 2012

This paper presents control strategies for cascaded H-bridge multilevel active power filters (APFs). A current loop controller is implemented using a proportional-resonant (PR) regulator, which achieves zero steady-state error at target frequencies. The power balancing mechanism for the dc-link capacitor voltages is analyzed and a voltage balancing controller is presented. To mitigate the picket-fence effect of the conventional FFT algorithm under asynchronous sampling conditions, the Hanning Windowed-FFT algorithm is proposed for reference current generation (RCG). This calculates the frequency, amplitude and phase of individual harmonic components accurately and as a result, selective harmonic compensation (SHC) is achieved. Simulation and experimental results are presented, which verify the validity and effectiveness of the devised control algorithms.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2002년도 춘계공동학술대회
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• pp.877-884
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• 2002

This paper deals with a multi-stage TSK fuzzy modeling method by using Genetic Programming (GP). Based on the time sequence of sampling data the best structural change points of complex systems are detemined by using GP, and also the moving window is simultaneously introduced to overcome the excessive amount of calculation during the generating procedure of GP tree. Therefore, a multi-stage TSK fuzzy model that attempts to represent a complex problem by decomposing it into multi-stage sub-problems is addressed and its learning algorithm is proposed based on the Radial Basis Function (RBF) network. This approach allows us to determine the model structure and parameters by stages so that the problems ran be simplified.

• 수산해양교육연구
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• 제28권2호
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• pp.356-365
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• 2016

The purpose of this study was to verify the influences of sport enjoyment factors on recreation specialization of water sports participants. The study conducted a research survey through purposive sampling method after selecting 4 water sports center in Busan. 260 questionnaires distributed and 246 were selected as final valid sample by removing 14 questionnaires that have insufficient answers. Then data were analyzed through exploratory factor analysis, reliability analysis, correlation analysis, and multiple regression analysis using SPSS Window ver. 20.0. The results were as followings. First, the enjoyment factors have a positive effect on recreation specialization. Second, escaping from daily routine and improving technical skill dimensions of enjoyment factors have an influence on centrality of life. Third, improving technical skill dimension of enjoyment factors have a positive effect on past experience. Lastly, flow and improving technical skill dimensions of enjoyment factors have an influence on economic investment.

• 수산해양교육연구
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• 제29권2호
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• pp.492-502
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• 2017

The purpose of this study was to verify the influences of surfing participants' participation motivation on flow experience and continuous participation intention. The study conducted a research survey through purposive sampling method after selecting 2 surfing center in Ganwon-do. 280 questionnaires distributed and 269 were selected as final valid sample by removing 11 questionnaires that have insufficient answers. Then data were analyzed through exploratory factor analysis, reliability analysis, correlation analysis, and multiple regression analysis using SPSS Window ver. 20.0. The results were as followings. First, participation motivation factors have positive effect on flow experience. Second, participation motivation factors have an influence on continuous participation intention. Third, flow experience have an influence on continuous participation intention. Fourth, leisure flow have an influence on continuous participation intention.

• 융합보안논문지
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• 제13권3호
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• pp.9-15
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• 2013

스테레오 매칭 과정에 있어서 매칭 비용을 구하는 것은 매우 중요한 과정이다. 이러한 스테레오 매칭 과정의 성능을 살펴보기 위하여 본 논문에서는 기존에 제안된 매칭 비용 함수들에 대한 기본 개념들을 소개하고 각각의 성능 및 장점을 분석하고자 한다. 가장 간단한 매칭 비용 함수는 매칭 되는 영상의 일관된 밝기를 이용하여 좌, 우 영상 간 서로 대응하는 대응점을 추정하는 과정으로, 본 논문에서 다루는 매칭 비용함수는 화소 기반과 윈도우 기반의 매칭 비용 방법으로 크게 두 가지로 나눌 수 있다. 화소 기반의 방법으로는 절대 밝기차(the absolute intensity differences: AD)와 sampling-intensitive absolute differences of Birchfield and Tomasi (BT) 방법이 있고, 윈도우 기반의 방법으로는 차이 절대 값의 합(sum of the absolute differences: SAD), 차이 제곱 값의 합(sum of squred differences: SSD), 표준화 상호상관성(normalized cross-correlation: NCC), 제로 평균 표준화 상호 상관성(zero-mean normalized cross-correlation: ZNCC), census transform, the absolute differences census transform (AD-Census) 이 있다. 본 논문에서는 앞서 언급한 기존에 제안된 매칭 비용 함수들을 정확도와 시간 복잡도를 측정했다. 정확도 측면에서 AD-Census 방법이 평균적으로 가장 낮은 매칭 율을 보여줬고, 제로 평균 표준화 상호 상관성 방법은 non-occlusion과 all 평가 항목에서 가장 낮은 매칭 오차율을 보여 주지만, discontinuities 평가 항목에서는 블러 효과 때문에 높은 매칭 오차율을 보여 주었다. 시간 복잡도 측면에서는 화소 기반인 절대 밝기차 방법이 낮은 복잡도를 보여 주였다.

• 한국융합학회논문지
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• 제10권12호
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• pp.109-115
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• 2019

본 연구는 요양시설 치매노인들의 인지기능과 구강건강상태 및 구강 내 병원성 미생물의 관계를 파악하기 위해 시도되었다. 대구소재 요양기관에 거주하는 70세 이상 치매노인이라는 특수성으로 비확률적 표본방식을 통해 30명을 대상으로 2019년 2월 한 달간 자료를 수집하였다. SPSS window ver. 21.0 프로그램을 이용하여 기술통계, ANOVA, Pearson's 상관계수로 분석하였다. 연구결과 요양판정등급이 낮을수록 고위험 병원성 세균이 많았고, 현존 치아수가 많을수록 구강 내 미생물의 수가 높게 나타났다. 하지만 인지기능과는 무의미한 차이를 보였다. 따라서, 요양시설의 치매노인 구강건강 관리를 위해서는 구강 내 환경에 따라 관리 방법을 달리하여야 하고 실제적인 건강관리를 위해서는 전문적인 관리자가 구강건강관리를 할 수 있어야 한다고 제언한다.

• 대한치과보철학회지
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• 제44권4호
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• pp.374-382
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• 2006

Purpose: This study was designed to investigate the present conditions of illumination techniques in dental clinics in order to contribute improvement of operating environment. This study also aimed exploring qualitative and quantitative luminous intensity required for color temperature in dental clinic illumination, which was a critical part of esthetic dentistry. Materials and methods: A total of forty-eight local dental clinics were selected for sampling a) luminous intensity, and b) color temperature. The author measured the luminous intensity and the color temperature with lux meter and color meter respectively between 12pm and 2pm. The dental unit chair placed in the general operation positions were kept the distance 60 cm then all dental units were measured three times and averaged. The author measured the luminous intensity and color temperature with both common dental operating light and then without operating light in different office environments. The study was conducted under three conditions: 1 artificial illumination in clear day light 2. artificial illumination in cloudy day light, and 3. artificial illumination alone. Results : The results obtained were as follows. 1. The average luminous intensity in dental clinic lighting was 425 lux which was not sufficient to produce the optimal shade of the patient's teeth. Furthermore, the average luminous intensity even in full operating lighting was 9532 lux which fell short of the required level of 10,000 lux. 2. The average color temperature of all dental clinics surveyed was 5169 K which met the optimal range. However, only 33.3% fell in the correct region between 5,000-5,500 K as 25% were over 5,500 K and 41.6% were below 5,000 K. As a result, 66.7% were under insufficient color temperature conditions. 3. The dental unit chair placed next to a window, hence exposure to natural lighting, had significantly higher luminous intensity and color temperature compared to the dental unit chair which didn't have a window or natural lighting. 4. The data analysis revealed that only 6.3% of the dental clinic were met the standard of the average luminous intensity and color temperature.

• 시스템엔지니어링학술지
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• 제16권2호
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• pp.27-37
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• 2020

The Fukushima Daiichi accident in 2011 revealed some vulnerabilities of existing Nuclear Power Plants (NPPs) under extended Station Blackout (SBO) accident conditions. One of the key Severe Accident Management (SAM) strategies developed post Fukushima accident is the In-Vessel Retention (IVR) Strategy which aims to retain the structural integrity of the Reactor Pressure Vessel (RPV). RELAP/SCDAPSIM/MOD3.4 is selected to predict the thermal-hydraulic response of APR1400 undergoing an extended SBO. To assess the effectiveness of the IVR strategy, it is essential to quantify the underlying uncertainties. In this work, both the epistemic and aleatory uncertainties are considered to identify the success window of the IVR strategy. A set of in-vessel relevant phenomena were identified based on Phenomena Identification and Ranking Tables (PIRT) developed for severe accidents and propagated through the thermal-hydraulic model using Wilk's sampling method. For this work, a Systems Engineering (SE) approach is applied to facilitate the development process of assessing the reliability and robustness of the APR1400 IVR strategy. Specifically, the Kossiakoff SE method is used to identify the requirements, functions and physical architecture, and to develop a design verification and validation plan. Using the SE approach provides a systematic tool to successfully achieve the research goal by linking each requirement to a verification or validation test with predefined success criteria at each stage of the model development. The developed model identified the conditions necessary for successful implementation of the IVR strategy which maintains the vessel integrity and prevents a melt-through.