• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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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.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.4
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• pp.727-738
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• 2015

Until recently, power analysis is one of the most popular research issues among various side channel analyses. Since Differential Power Analysis had been first proposed by Kocher et al., various practical power analyses correspond with software/hardware cryptographic devices have been proposed. In this paper, we analyze vulnerability of countermeasure against power analysis exploiting single power trace of public cryptographic algorithm. In ICICS 2010, Clavier et al. proposed Horizontal Correlation Analysis which can recover secret information from a single exponentiation trace and corresponding countermeasures. "Blind operands in LIM", one of their countermeasures, exploits additive blinding in order to prevent leakage of intermediate value related to secret information. However, this countermeasure has vulnerability of having power leakage that is dependant with the message known by an adversary. In this paper, we analyzed vulnerabilities by three attack scenarios and proved them by practical correlation power analysis experiments.

• Convergence Security Journal
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• v.18 no.5_1
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• pp.59-66
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• 2018

The performance of a network intrusion detection system using the machine learning method depends heavily on the composition and the size of the feature set. The detection accuracy, such as the detection rate or the false positive rate, of the system relies on the feature composition. And the time it takes to train and detect depends on the size of the feature set. Therefore, in order to enable the system to detect intrusions in real-time, the feature set to beused should have a small size as well as an appropriate composition. In this paper, we show that the size of the feature set can be further reduced without decreasing the detection rate through using Pearson correlation coefficient between features along with the multi-objective genetic algorithm which was used to shorten the size of the feature set in previous work. For the evaluation of the proposed method, the experiments to classify 10 kinds of attacks and benign traffic are performed against NSL_KDD data set.

• Bulletin of the Korean Chemical Society
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• v.32 no.11
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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.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.04a
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• pp.383-384
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• 2010

The control surface on a ship is to control the motion of it in forward and backward states. In this paper, the measured results has been compared with each other to predict the backward flow characteristics of the single rudder's 2-dimensional section at $Re=2.0\times10^4$ using 2-frame grey level cross correlation PIV method especially, The separation region appears at 10 to 20 degrees angle of attack in a forward state. The separation point and boundary layer demonstrate in the same angle of attack compared it with the forward states.

• The Plant Pathology Journal
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• v.18 no.2
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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.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.9 no.2
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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.

• Convergence Security Journal
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• v.6 no.4
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• pp.67-73
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• 2006

The method which research a standardization from real time cyber threat is finding the suspicious indication above the attack against cyber space include internet worm, virus and hacking using analysis the event of each security system through correlation with the critical point, and draft a general standardization plan through statistical analysis of this evaluation result. It means that becomes the basis which constructs the effective cyber attack response system. Especially at the time of security accident occurrence, It overcomes the problem of existing security system through a definition of the event of security system and traffic volume and a concretize of database input method, and propose the standardization plan which is the cornerstone real time response and early warning system. a general standardization plan of this paper summarizes that put out of threat index, threat rating through adding this index and the package of early warning process, output a basis of cyber threat index calculation.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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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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• v.30 no.2
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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.