• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2013년도 춘계학술발표대회
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• pp.659-662
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• 2013

과거에는 보안디바이스의 안전성을 탑재된 암호알고리즘의 안전성에 의존하였다. 하지만 부채널 분석을 통해 암호알고리즘의 안전성과는 별개로 부채널 정보에 의한 보안디바이스의 물리적 취약성이 존재함이 밝혀졌다. 이러한 보안디바이스의 물리적 취약성을 보완하기 위해서는 최소 2차 상관전력분석에 대한 대응법이 간구되어야 한다. 최근 2차 상관전력분석에 대한 실용적인 대응법으로 1차 마스킹과 셔플링을 혼합한 방법을 많이 활용하고 있다. 하지만 1차 마스킹과 셔플링이 혼합된 부채널 대응법을 1차 상관전력분석으로 분석하였을 경우, 특이한 피크가 발생한다. 본 논문에서는 마스킹과 셔플링이 혼합된 부채널 대응법을 1차 상관전력분석으로 분석하였을 때, 특이한 피트가 발생함을 실험적으로 확인하였고, 그 피크 발생 원인을 소개한다. 뿐만 아니라, 피크 발생 정보를 추가적인 부채널 분석 정보로 활용할 수 있는 방법을 소개한다.

• 정보보호학회논문지
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• 제25권4호
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• pp.727-738
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• 2015

현재 전력 분석은 여러 가지 부채널 분석 중 가장 활발하게 연구되고 있다. 1999년 Kocher 등에 의해 차분 전력 분석이 제안된 이후로 소프트웨어/하드웨어 기반 암호 디바이스를 대상으로 하는 다양하고 현실적인 전력 분석 공격이 제안되었다. 본 논문은 공개키 암호 알고리즘에 대하여 단 하나의 파형을 이용하는 전력분석에 안전한 대응기법의 취약성을 분석한다. 2010년 ICICS에서 Clavier 등은 단 하나의 지수승 파형으로 비밀 정보를 찾아낼 수 있는 수평적 상관관계 분석과 그에 대한 대응기법을 제안하였다. 그 중 하나인 "Blind operands in LIM" 대응기법은 큰 정수 곱셈의 두 입력에 대한 덧셈 블라인딩을 이용하여 비밀정보와 관련된 중간 값 노출을 막는다. 그럼에도 불구하고 이 대응기법은 공격자가 알고 있는 평문에 대한 전력 누설을 일으킬 수 있는 취약점을 가지고 있다. 본 논문에서는 세 가지 공격시나리오를 통해 취약점을 분석했고 실제적인 실험을 통해 이를 증명하였다.

• 융합보안논문지
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• 제18권5_1호
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• pp.59-66
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• 2018

기계학습을 이용하는 침입 탐지 시스템의 성능은 특징 집합의 구성과 크기에 크게 좌우된다. 탐지율과 같은 시스템의 탐지 정확도는 특징 집합의 구성에, 학습 및 탐지 시간은 특징 집합의 크기에 의존한다. 따라서 즉각적인 대응이 필수인 침입 탐지 시스템의 실시간 탐지가 가능하도록 하려면, 특징 집합은 크기가 작으면서도 적절한 특징들로 구성하여야 한다. 본 논문은 실시간 탐지를 위한 특징 집합 선택 문제를 해결하기 위해 사용했던 기존의 다목적 유전자 알고리즘에 특징 간의 Pearson 상관계수를 함께 사용하면 탐지율을 거의 낮추지 않으면서도 특징 집합의 크기를 줄일 수 있음을 보인다. 제안한 방법의 성능평가를 위해 NSL_KDD 데이터를 사용하여 10가지 공격 유형과 정상적인 트래픽을 구별하도록 인공신경망을 설계, 구현하여 실험한다.

• Bulletin of the Korean Chemical Society
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• 제32권11호
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• pp.3947-3951
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• 2011

The nucleophilic substitution reactions of Y-aryl ethyl chlorothiophosphates with X-pyridines are studied kinetically in acetonitrile at $55.0^{\circ}C$. The Hammett and Bronsted plots for substituent X variations in the nucleophiles exhibit biphasic concave upwards with a break point at X = 3-Me. The substituents of X = 4-CN and 4-Ac show great positive deviations from both the Hammett and Bronsted plots. The Hammett plots for substituent Y variations in the substrates exhibit biphasic concave upwards with a minimum point at Y = H. The obtained values of the cross-interaction constants (${\rho}_{XY}$) are all in spite of the biphasic free energy correlations for both substituent X and Y variations, since the ${\rho}_X$values with both the strongly and weakly basic pyridines are almost constant. A stepwise mechanism with a rate-limiting leaving group departure from the intermediate is proposed where the distance between X and Y does not vary from the intermediate to the second transition state. A frontside attack is proposed with the strongly basic pyridines based on the considerably great magnitudes of ${\rho}_X$ and ${\beta}_X$ values and a backside attack is proposed with the weakly basic pyridines based on the relatively small magnitudes of ${\rho}_X$ and ${\beta}_X$. The positive deviations of the two strong ${\pi}$-acceptor parasubstituents, X = 4-Ac and 4-CN, from both the Hammett and Bronsted plots are rationalized by the great extents of bond formation and breaking.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2010년도 춘계학술대회
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• pp.383-384
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• 2010

선박의 제어판은 전진 또는 후진시 조종성능을 결정하는 중요한 요소이다. 본 연구에서는 단동타의 성능평가를 위하여 $Re=2.0\times10^4$ 에서 2-프레임 그레이레벨 상호상관 PIV기법을 이용하여 모텔 주위의 속도장을 계측하였다. 특히 전진시 영각 10도와 20도 사이에서 발생하는 박리영역을 후진시에 나타나는 영향을 평가하였다. 단동타의 형상은 NACA0018을 사용하여 자유유동이 역 방향으로 위치하여 후진시의 효과를 알아본 결과 박리 영역은 전방과 비슷한 영각에서 발생함을 알 수 있었다.

• The Plant Pathology Journal
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• 제18권2호
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• pp.68-73
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• 2002

The influence of fungicidal spray was assessed on powdery mildew epidemics caused by Erysiphe polygoni D.C. and on yield-attributing characters of mungbean [Vigna radiata (L.) Wilczek]. Mildew attack adversely affected the yield-attributing characters of mungbean and exhibited negative significant correlation with pod length (-0.57), pods/plant (-0.74), pod weight (-0.68), 100 seeds weight (-0.69), 100 seeds swell weight (-0.59), and seed germination (-0.71). These characters had direct or indirect effects on grain yield, which was also adversely affected due to mildew attack (-0.89). Powdery mildew was significantly retarded due to the single spray of carbendazim (0.05%) at 30-day-old crop, where the apparent rate of infection (r) was minimum at 0.0095/ unit/day and with low (11.44%) powdery mildew intensity. Other fungicides like tridemorph (0.075%) and penconazole (0.05%) were equally effective against the mildew disease where the disease intensity was less than 20% and the values of r were 0.0134 and 0.039/unit/day respectively, as compared with the control at 0.267/unit/day. Fungicide spray influenced the yield-attributing characters besides controlling the disease. Such effects were more pronounced in carbendazim (0.05%)-treated plots due to its phytotonic nature where pod length (7.59cm), pods/plant (29.75), pod weight (8.16 g), 100 grain weight (3.94 g), and swell weight of 100 seed (9.49 g) were maximum resulting to the highest yield (480 kg/ha) as compared with that of control (224 kg/ha). Spray of carbendazim also improved seed germination (74.5%). Spray of other fungicides like carbendazim with copper oxychloride in 1:1 ratio, tridemorph (0.075%), and penconazole (0.05%) was equally effective against powdery mildew of mungbean. These fungicides also exhibited positive effects on yield-attributing characters of the crop and finally increased yield. These systemic fungicides were more effective in controlling powdery mildew disease of V. radiata in the rainy season compared with wettable sulphur.

• 가정∙방문간호학회지
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• 제9권2호
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• pp.78-89
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• 2002

The purpose of this study was to identity degree on self-care agency & self efficacy of hemodialisis patients. The subjects for the study consisted of 260 hemodialisis patients and the data were collected from April 1st. 2002 to April 30. 2002. The instruments used for this study were the Self-carer As Inventory Scale(Genden & Taylor. 1998) and Concrete Self Efficacy Scale(Joo-Hyen Kim. 1995). The Self-carer As Inventory translated by So Hyang-Sook and was modified by auther of this study. The data were analysed by using SPSS/WIN program and included number. percentange. t-test, ANOV A and Pearson Correlation Coefficient. The results of the study are summarized as follows. 1. As the average score Self-care agency indicated $132.21\pm19.11$ points and Self efficacy showed $597.33\pm130.95$points. it can be said that Self-care agency and Self efficacy were high. 2. In the relationship between general and hemodialisis cure characteristics and Self care agency were significant difference in age(F=3.065. p=0.018). married(F=3.160. p= 0.029). religion(F=4.128. p=0.003). hemodialisis cure duration(F=2.615. p=0.049). 3. In the relationship between general and hemodialisis cure characteristics and Self efficacy were significant difference in age (F=2.992. p=0.019). married(F=4.427. p=0.013), job(before attack-F=1.926. p=0.044. after attack-F=1.784. p=0.048). incomes (F=2.235. p=0.041), hemodialisis cure frequency (F=1.718. p=0.042). diet practice (F=2.248. p=0.025). 4. Self efficacy was significantly related to Self-care agency(r=0.474. p<(0.001). That is the higher the self efficacy. the higher the level of Self-care agency. The result in the above showed that more concern and endeavors need to improve hope. medical support. self efficacy, self-care agency of hemodialisis patients.

• 융합보안논문지
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• 제6권4호
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• pp.67-73
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• 2006

실시간 사이버위협에서 정형화 방법은 각 보안장비의 이벤트를 실시간 분석하여 인터넷 웜, 바이러스, 해킹 등의 사이버공격에 대한 네트워크 이상 징후를 임계치와 상관관계를 틀 통하여 탐지하고, 동 평가결과의 통계분석을 통해 정형화 방안 기능을 부여하고 실효성 있는 사이버공격대응시스템을 구축하는데 있다. 본 논문은 우선 위협지표 산출과 동 지표의 합산을 통한 위협평가 및 조기 경보 과정의 패키지화로 만들고, 사이버 위협 지표 계산의 기준을 설정한다. 특히 보안사고 발생 시 각 보안장비의 이벤트와 트래픽 양에 대한 정의 및 데이터베이스 입력 방법을 구체화하여 실시간 대응 및 조기예경보체계의 초석이 가능한 정형화 방안을 제시한다. 분석을 위해 축적한 90일간의 데이터 임계치 설정작업을 통해 보다 정확한 적용 값을 계산한다. 산출한 값을 토대로 정형화가 가능한 보안이벤트 정보를 표준데이터로 적용, 각 보안장비 및 HoneyNet 시스템, 기타 취약정보 등과의 상관관계를 분석하여 보안이벤트 표준지수를 산출한다.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4185-4190
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• 2011

The nucleophilic substitution reactions of ethylene phosphorochloridate (1c) with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are investigated kinetically in acetonitrile at $5.0^{\circ}C$. The anilinolysis rate of 1c involving a cyclic five-membered ring is four thousand times faster than its acyclic counterpart (1a: diethyl chlorophosphate) because of great positive value of the entropy of activation of 1c (${\Delta}S^{\neq}=+30\;cal\;mol^{-1}K^{-1}$ compared to negative value of 1a (${\Delta}S^{\neq}=-45\;cal\;mol^{-1}K^{-1}$) over considerably unfavorable enthalpy of activation of 1c (${\Delta}H^{\neq}=27.7\;kcal\;mol^{-1}$) compared to 1a (${\Delta}H^{\neq}=8.3\;kcal\;mol^{-1}$). Great enthalpy and positive entropy of activation are ascribed to sterically congested transition state (TS) and solvent structure breaking in the TS. The free energy correlations exhibit biphasic concave upwards for substituent X variations in the X-anilines with a break point at X = 3-Me. The deuterium kinetic isotope effects are secondary inverse ($k_H/k_D$ < 1) with the strongly basic anilines and primary normal ($k_H/k_D$ > 1) with the weakly basic anilines and rationalized by the TS variation from a dominant backside attack to a dominant frontside attack, respectively. A concerted $S_N2$ mechanism is proposed and the primary normal deuterium kinetic isotope effects are substantiated by a hydrogen bonded, four-center-type TS.

• Wind and Structures
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• 제30권2호
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• pp.181-198
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• 2020

In the traditional buffeting response analysis method, the spanwise incomplete correlation of buffeting forces is always assumed to be same as that of the incident wind turbulence and the action of the signature turbulence is ignored. In this paper, three typical bridge decks usually adopted in the real bridge engineering, a single flat box deck, a central slotted box deck and a two-separated paralleled box deck, were employed as the investigated objects. The wind induced pressure on these bridge decks were measured via a series of wind tunnel pressure tests of the sectional models. The influences of the wind speed in the tests, the angle of attack, the turbulence intensity and the characteristic distance were taken into account and discussed. The spanwise root coherence of buffeting forces was also compared with that of the incidence turbulence. The signature turbulence effect on the spanwise root coherence function was decomposed and explained by a new empirical method with a double-variable model. Finally, the formula of a sum of rational fractions that accounted for the signature turbulence effect was proposed in order to fit the results of the spanwise root coherence function. The results show that, the spanwise root coherence of the drag force agrees with that of incidence turbulence in some range of the reduced frequency but disagree in the mostly reduced frequency. The spanwise root coherence of the lift force and the torsional moment is much larger than that of the incidence turbulence. The influences of the wind speed and the angle of attack are slight, and they can be ignored in the wind tunnel test. The spanwise coherence function often involves several narrow peaks due to the signature turbulence effect in the high reduced frequency zone. The spanwise coherence function is related to the spanwise separation distance and the spanwise integral length scales, and the signature turbulence effect is related to the deck-width-related reduced frequency.