• Journal of the Korean Chemical Society
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• v.18 no.6
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• pp.423-429
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• 1974

The rate constant of the addition of hydrogen cyanide to $ ${\alpha}$-cyano-\beta-piperonylacrylic$ acid (CPA) were determined by UV spectrophotometry at various pH and a rate equation which can be applied over wide pH range was obtained. From this equation, one may conclude that below pH 3 the reaction is started by the addition of hydrogen cyanide molecule to CPA, however, at pH 6~8, hydrogen cyanide is added to $ {\alpha}$-cyano-$ {\beta}$-piperonyl acrylate anion. From pH 3 to 6, these two reaction are competitive. Above pH 9, the reaction is proceeded by the addition of cyanide ion to $ {\alpha}$-cyano-$ {\beta}$-piperonyl acrylate ion. From pH 3 to 9, the complex reaction mechanism can also be fully explained by the rate equation obtained.

• Journal of the Korean Chemical Society
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• v.34 no.3
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• pp.232-238
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• 1990

To study the biological roles of Zn, we investigated simple model systems of $Zn^{++}, coordinated with OH_2 or NH_3,$ or with O=C- in peptide. The geometrical structures and net atomic charges were calculated by the ab initio HF-SCF theory using double zeta basis sets. The ligands of O-H, N-H, and O=C- are very polar due to $Zn^{++}$. Therefore, the carbon atom in peptide becomes so electrophilic that it can be easily attacked by other nucleophiles. In addition, to understand how $Zn^{++}$ is coordinated with ligands in enzyme, a molecular mechanics method is applied to the system of the enzyme of carboxypeptidase A (CPA) with the substrate of glycyltyrosine. From our results, it appears that the Zn ion is coordinated not only by four ligands in enzyme and substrate but also by one water molecule.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.6
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• pp.1059-1068
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• 2022

A Post-Quantum Cryptographic algorithm NTRU, which is designed by considering the computational power of quantum computers, satisfies the mathematically security level. However, it should consider the characteristics of side-channel attacks such as power analysis attacks in hardware implementation. In this paper, we verify that the private key can be recovered by analyzing the power signal generated during the decryption process of NTRU. To recover the private keys, the Simple Power Analysis (SPA), Correlation Power Analysis (CPA) and Differential Deep Learning Analysis (DDLA) were all applicable. There is a shuffling technique as a basic countermeasure to counter such a power side-channel attack. Neverthe less, we propose a more effective method. The proposed method can prevent CPA and DDLA attacks by preventing leakage of power information for multiplication operations by only performing addition after accumulating each coefficient, rather than performing accumulation after multiplication for each index.

• Nutrition Research and Practice
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• v.17 no.2
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• pp.206-217
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• 2023

BACKGROUND/OBJECTIVES: The immunomodulatory effect of Platycodon grandiflorum (PG) has been reported, but studies on its mechanism are still lacking. This study was undertaken to confirm whether the hydrolyzed and fermented PG extract (HFPGE) obtained by adding hydrolysis and fermentation to the extraction process has an immune-enhancing effect in the in vivo system. MATERIALS/METHODS: Five-week-old BALB/c mice were divided into 4 groups: normal control group (NOR), control group (CON), 150 mg/kg body weight (BW)/day HFPGE-treated group (T150), and 300 mg/kg BW/day HFPGE-treated group (T300). The mice were administered HFPGE for 4 weeks and intraperitoneally injected with cyclophosphamide (CPA, 80 mg/kg BW/day) on day 6, 7, and 8, respectively, to induce immunosuppression. The levels of immunoglobulins (Igs) and cytokines were measured in the serum. In splenocytes, proliferation and cytokine levels were measured. RESULTS: Serum IgA, IgG, and IgM levels were observed to decrease after CPA treatment, which was recovered by HFPGE administration. The levels of serum interleukin (IL)-12, tumor necrosis factor (TNF)-α, IL-8, and transforming growth factor (TGF)-β were also decreased after exposure to CPA but increased after HFPGE administration. Decreased splenocyte proliferation was seen in CPA-treated mice, but was observed to increase in the T150 and T300 groups as compared to the NOR group. Compared to the CON group, splenocyte proliferation stimulated with concanavalin A (ConA) or lipopolysaccharide (LPS) in the HFPGE-treated groups was significantly increased. The cytokines secreted by ConA-stimulated splenocytes (IL-2, IL-12, interferon-γ, TNF-α) were increased in the T150 and T300 groups, and cytokines secreted by LPS-stimulated splenocytes (IL-4, IL-8, TGF-β) were also increased by HFPGE administration. CONCLUSION: These results suggest that HFPGE stimulates the immunity in immunosuppressed conditions, thereby enhancing the immune response. Therefore, it is expected that HFPGE has the potential to be used as functional food and medicine for immune recovery in various immunocompromised situations.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.1
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• pp.33-43
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• 2023

The National Institute of Standards and Technology (NIST), which is working on the Post-Quantum Cryptography (PQC) standardization project, announced four algorithms that have been finalized for standardization. In this paper, we demonstrate through experiments that private keys can be exposed by Correlation Power Analysis (CPA) and Differential Deep Learning Analysis (DDLA) attacks on polynomial coefficient-wise multiplication algorithms that operate in the process of generating signatures using CRYSTALS-Dilithium algorithm. As a result of the experiment on ARM-Cortex-M4, we succeeded in recovering the private key coefficient using CPA or DDLA attacks. In particular, when StandardScaler preprocessing and continuous wavelet transform applied power traces were used in the DDLA attack, the minimum number of power traces required for attacks is reduced and the Normalized Maximum Margines (NMM) value increased by about 3 times. Conseqently, the proposed methods significantly improves the attack performance.

• Journal of Advanced Navigation Technology
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• v.25 no.6
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• pp.485-492
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• 2021

Vision-based autonomous precision landing technology for UAVs requires precise position estimation and landing guidance technology. Also, for safe landing, it must be designed to determine the safety of the landing point against ground obstacles and to guide the landing only when the safety is ensured. In this paper, we proposes vision-based navigation, and algorithms for determining the safety of landing point to perform autonomous precision landings. To perform vision-based navigation, CNN technology is used to detect landing pad and the detection information is used to derive an integrated navigation solution. In addition, design and apply Kalman filters to improve position estimation performance. In order to determine the safety of the landing point, we perform the obstacle detection and position estimation in the same manner, and estimate the speed of the obstacle using LSM. The collision or not with the obstacle is determined based on the CPA calculated by using the estimated state of the obstacle. Finally, we perform flight test to verify the proposed algorithm.

• Clinical and Experimental Reproductive Medicine
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• v.37 no.4
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• pp.307-319
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• 2010

Objective: Vitrification requires a high concentration of cyroprotectant (CPA) and an elevated cooling speed to avoid ice crystal formation. We have evaluated the effect of different combinations of cooling rate and CPA on embryonic integrity (developmental competence) in order to increase the efficiency of vitrification without impairing embryo viabilit. We hypothesized that the combination of CPA or the increase of cooling rates can reduce the concentration of toxic CPA for vitrification. As consequently, we performed experiments to evaluate the effect of various composition of CPA or slush nitrogen ($SN_2$) on the mouse embryonic development following vitrification using low CPA concentration. Methods: Vitrification of mouse embryos was performed with EM grid using liquid nitrogen ($LN_2$) or $SN_2$ and different composition of CPAs, ethylene glycol (EG) and dimethylsulfoxide (DMSO). After vitrification-warming process, their survival and blastocyst formation rates were examined. For analyzing long-term effect, these blastocysts were transferred into the uterus of foster mothers. Results: Survival and blastocyst formation rates of vitrified embryos were higher in EG+DMSO group than those in EG only. Furthermor, the group using $SN_2$ with a lower CPA concentration showed a higher survival of embryos and developmental rates than group using $LN_2$. Conclusion: The combination of EG and DMSO as CPAs may enhance the survival of mouse embryos and further embryonic development after vitrification. $SN_2$ can generate high survival and developmental rate of vitrified/warmed mouse embryos when a lower concentration of CPA was applied. Therefore, these systems may contribute in the improvement of cryopreservation for fertility preservation.

• Child Studies in Asia-Pacific Contexts
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• v.7 no.1
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• pp.15-26
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• 2017

The aim of this study was to retrospectively estimate the prevalence of childhood emotional abuse (CEA), childhood physical abuse (CPA), and childhood contact sexual abuse (CCSA) in relation to adult poor mental health, addictive behavior, and other health-risk behaviors among university students in five ASEAN countries (Indonesia, Malaysia, Myanmar, Thailand, and Vietnam). In a cross-sectional survey, 3,240 undergraduate university students were randomly selected (M age = 20.5 years, SD = 1.6 years) to respond to a questionnaire including the Abuse section of the World Health Organization (WHO) Version 1 "Adverse Childhood Experiences International Questionnaire" (ACE-IQ) and other measures. The students reported 17.9% CEA, 28.2% CPA, and 22.4% CCSA, with the highest prevalence of CEA in Myanmar (30.9%) and CPA and CCSA in Vietnam (55.8% and 41.6%, respectively). In logistic regression models, adjusting for sociodemographic and social variables, the separate and cumulative effects of three types of child abuse (emotional, physical, and sexual) were found to increase the risks for poor adult mental health, addictive, and other health-risk behaviors.

• Proceedings of the Korea Contents Association Conference
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• 2017.05a
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• pp.423-424
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• 2017

상황버섯은 오랜 역사와 전통이 있는 소재로서 폴리페놀류가 함유되어 있어 항암, 혈중콜레스테롤 저하, 혈압강하 등의 약리효과가 있는 것으로 알려져 있다. 본 연구에서는 in vivo 실험을 통해 CPA (Cyclophosphamide)로 유도된 면역저하 마우스 모델에서 상황버섯 투여 농도에 따른 cytokine 활성 효과를 확인하여 상황버섯의 면역 증진 효과를 평가하고, 유효한 농도를 선정하여 시제품을 제작하고자 하였다. 연구결과, 림프기관 장기 무게(흉선, 비장, 악하림프절)와 혈청과 비장의 cytokine이 CPA군(CPA control)에 비해 상황버섯 추출물 투여군에서 유의적으로 증가하였다. 또한 실험을 퉁해 선정한 유효한 농도인 50 mg/kg의 농도로 시제품을 제작하였으며, 상황버섯 특유의 떫은 맛을 감쇄하기 위해 아스코르빈산과 NaHCO3을 첨가하여 최적 배합 비율을 선정하여 음료 200 mL당 상황버섯 추출물 55.6 mg (0.0278%), 아스코르빈산 200 mg (0.1%), NaHCO3 60 mg (0.03%)이 함유 되도록 제작하였다. 본 연구 결과 상황버섯추출물은 CPA로 인해 감소된 사이토카인 분비를 상향 조절함으로써 면역저하 상태를 개선시켜 면역 증진 효과가 있는 것으로 판단된다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.7
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• pp.55-62
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• 2006

This thesis describes collision avoidance using fuzzy logic based on "Right of way" rules of ICAO and FAA and pilot's experiences for Unmanned Aerial Vehicle(UAV). To apply the rules, we designed fuzzy logic based collision avoidance system. And we also designed decision logic for enable condition of collision avoidance system. Decision logic have three kinds of core key, i.e. Relative Range, Time of CPA(Closest Point of Approach) and Distance at CPA. Application of decision logic made a possible to avoid NMAC(Near Mid-Air Collision) and it has been verified through several simulations. To conclude, we proposed the method to carry out "See and Avoid" ability on UAVs, which is capability to mingle with manned aircraft in civil airspace.