• 제목/요약/키워드: CPA

검색결과 285건 처리시간 0.023초

웨이블릿 잡음 제거 방법을 이용한 전력 분석 공격 성능 개선 (Performance Improvement of Power Analysis Attacks based on Wavelet De-noising)

  • 김완진;송경원;이유리;김호원;김형남
    • 한국통신학회논문지
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    • 제35권9B호
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    • pp.1330-1341
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    • 2010
  • 전력 분석 (Power Analysis, PA) 공격은 정보보안 영역에서 매우 효과적인 물리적 공격방법으로 알려져 있다. 이 공격방법은 보안 장치로부터 누설된 전력 소비 신호의 통계적인 특성을 분석하여 비밀 키 (secret keys)를 찾아낸다. 그러나 누설된 전력 신호의 값이 크지 않기 때문에, 잡음에 의해 PA 공격 성능이 저하될 수 있다. 이런 PA 공격의 잡음 민감성을 극복하기 위해, 본 논문에서는 웨이블릿 잡음 제거 (wavelet de-noising)에 기반한 공격 성능 향상 방법을 제안한다. 모의실험을 통해, 제안된 잡음 제거 방법이 공격 성공에 필요한 신호의 개수와 공격 결과의 신뢰도 측면에서 공격 효율을 향상시킴을 보인다.

HMC05의 경구투여 소핵시험 및 복귀돌연변이 시험 (Micronucleus Test in Bone Marrow Cells and Bacterial Reverse Mutation Assay of HMC05)

  • 신흥묵
    • 대한본초학회지
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    • 제25권2호
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    • pp.137-144
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    • 2010
  • Objectives : We investigated genetic toxicity of HMCO5 using the Micronucleus Test in bone marrow cells of mice and Bacterial Reverse Mutation Assay in plate incorporation method according to OECD Guidelines and KFDA Guidelines. Methods : 1. Micronucleus test: The male rats were divided into 5 groups, respectively; G(1), treated with distilled water: G(2), treated with 1250mg/kg HMC05: G(3), treated with 2500mg/kg HMC05, G(4), treated with 5,000mg/kg HMC05; G(5), treated with Cyclophosphamide $H_2O$. Sterilized distilled water and HMC05 were administered for two consecutive days. Cyclophosphamide $H_2O$ was administered once on the day of 2nd administration. 2. Bacterial Reverse Mutation Aassay: Experimental groups were divided into two groups: with S-9mix(+S) or without S-9mix(-S). Each group treated with sterilized distilled water only, HMCO5(62, 185, 556, 1,667, $5,000{\mu}g$/plate) and, positive vehicles(Sodium azide, 2-Aminoanthracene, 4-Nitroquinoline N-oxide, ICR 191), respectively. Results : HMC05 did not show any changes in the number of micronucleated polychromatic erythrocytes(MNPCE) among 200 polychromatic erythrocytes compare to negative control. However, there were significant (p<0.01) increase with CPA in MNPCE. In Bacterial Reverse Mutation Aassay, no significant increases in the number of revertant colonies compared to (삭제) negative control were detected in all concentrations of HMC05. Conclusions : These results indicate that HMC05 did not show any genotoxicity against in Micronucleus test and Bacterial Reverse Mutation Aassay.

선박충돌사고의 원인조사 및 분석방법에 관한 연구 (A Study on the Investigation and Analysis of Collisions at Sea)

  • 김상수;정재용;하원재;송두현;박진수
    • 한국항해학회지
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    • 제24권1호
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    • pp.13-22
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    • 2000
  • The collisions at sea among marine casualties are not reduced as the tonnage and speed of ship's increase as well as the traffic quantity increase at sea, in spite of the improvement of nautical equipment, enforcement of crew's education and training as well as improvement of quality standard according to the implementation of ISM code. The measures to prevent the collisions at sea are simple, and are composed of six stage.: The first stage is that the officer on duty detect the target from his eye or radar information. The second stage is determining the type and kind of target-ship. The third stage is target tracking; calculation of target speed, course, CPA and TCPA from radar information or visual check. The fourth stage is determination of vessel in danger after calculation of third stage. The fifth stage is the judgement of situation if own ship is stand-on or give way vessel according to the 1972 COLREG. The last stage is to carry out proper action according to 1972 COLREG, under the circumstances. But by the case, the situations are so different under the different external conditions; for example, natural/navigational conditions, crew's human factors, ship's particular, rule or regulation, management system on board, the condition of watch keeping. Therefore the reasons and casualties are so complicated. This study aims to investigate the collision casualty at sea which needs to clarity all these causal factors of afore-mentioned, and to analyze the causes of problems so as to utilize them to establish the measures of preventing marine accidents. This study, described the concepts of causal factors into three groups; environmental factor, and company/on board management system and navigator's act. Also described how to investigate and analyzes the casual factors. Even though it was described in this paper how to detect the causal factors and reasons of collisions, and how to analyze the inter-relation of each causal factors, it is necessary to do further study how to analyze between the liability of concerned parties and the casual factors involved.

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뺄셈연산의 이벤트 정보를 활용한 향상된 RSA-CRT 부채널분석공격 방법 (An Improved Side Channel Attack Using Event Information of Subtraction)

  • 박종연;한동국;이옥연;김정녀
    • 정보처리학회논문지:컴퓨터 및 통신 시스템
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    • 제2권2호
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    • pp.83-92
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    • 2013
  • RSA-CRT는 RSA전자서명 알고리즘의 고속화 구현을 위해 가장 많이 사용되고 있는 알고리즘으로, 스마트디바이스에 사용되는 RSA-CRT 알고리즘의 물리적 취약성 검증을 위해 CRT의 각 단계 연산에서 다양한 부채널 분석 이론이 발표되어 왔다. 본 논문에서는 RSA-CRT 구현에 사용되는 뺄셈연산의 이벤트 정보를 활용하여 RSA-CRT의 reduction알고리즘을 분석하는 새로운 SAED(Subtraction algorithm Analysis on Equidistant Data)분석 방법을 제안한다. SAED분석 방법은 알고리즘에 의존한 전력 변화를 이용한 분석 방법이며, 뺄셈 연산을 차분전력분석 방법으로 분석하여 키를 찾아낸다. 본 논문은 SAED분석 방법의 이론적인 합리성을 증명하고, 실험적으로 기존의 분석 방법보다 향상된 결과를 가짐을 보인다. 실험 결과 256개의 파형만으로 하나의 바이트를 분석해 낼 수 있어, 기존 논문보다 효율적인 분석 방법임을 확인 할 수 있었다.

국제해상충돌예방규칙에 따른 충돌회피 알고리즘에 관한 연구 (A Study on Ship Collision Avoidance Algorithm by COLREG)

  • 김동균;정중식;박계각
    • 한국지능시스템학회논문지
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    • 제21권3호
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    • pp.290-295
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    • 2011
  • 최근접점과 최근접시간에 기초를 둔 종래 선박충돌회피 알고리즘은 국제해상충돌예방규칙(COLREG, International Regulations for Preventing Collisions at Sea, 1972)에 의한 선박간의 항법규정을 고려하지 않는다는 문제점이 있다. 본 논문에서 제안하는 알고리즘은 조우선박의 상대방위를 측정함으로써 자선이 피항선인가 유지선이 될 것인가를 판단한다. 피항시점을 결정하기 위하여 타원형의 선박안전영역 모델을 이용하여 타선과 위험한 위치에 도달하는 지점과 시간을 계산함으로써 피항을 수행한다. 두 선박의 위치, 속도 및 방위를 임의로 생성하여 타원모델에 의한 충돌회피 과정을 시뮬레이션 한다. 또한 실제적인 해양사고 발생 자료를 이용하여 충돌위험 분석 및 선박간 충돌회피를 위한 방안을 제시한다. 제안한 알고리즘은 안개 및 기상악화의 경우 시계가 제한되거나 야간항해 중 항해등의 식별이 어려워 피항선과 유지선의 판단이 불확실한 경우에도 국제해상충돌예방규칙에 의한 충돌회피 동작에 효과적으로 적용할 수 있다.

Inhibitory Mechanism of Bromocriptine on Catecholamine Release Evoked by Cholinergic Stimulation and Membrane Depolarization from the Rat Adrenal Medulla

  • Lim, Dong-Yoon;Lee, Yong-Gyoon;Kim, Il-Hwan
    • Archives of Pharmacal Research
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    • 제25권4호
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    • pp.511-521
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    • 2002
  • The purpose of this study was to determine whether bromocriptine affects the catecholamines (CA) secretion evoked in isolated perfused rat adrenal glands, by cholinergic stimulation, membrane depolarization and calcium mobilization, and to establish the mechanism of its action. The perfusion of bromocriptine ($1~10{\;}{\mu}M$) into an adrenal vein, for 60 min, produced relatively dose-dependent inhibition in the secretion of catecholamines (CA) evoked by acetylcholine (ACh, 5.32 mM), DMPP ($100{\;}{\mu}M$ for 2 min), McN-A-343 ($100{\;}{\mu}M$ for 2 min), cyclopiazonic acid (CPA, $10{\;}{\mu}M$ for 4 min) and Bay-K-8644 ($10{\;}{\mu}M$ for 4 min). High $K^+$ (56 mM)-evoked CA release was also inhibited, although not in a dose-dependent fashion. Also, in the presence of apomorphine ($100{\;}{\mu}M$), which is also known to be a selective $D_2$-agonist, the CA secretory responses evoked by ACh, high potassium, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid were also significantly depressed. However, in adrenal glands preloaded with bromocriptine ($3{\;}{\mu}M$) in the presence of metoclopramide ($15{\;}{\mu}M$), a selective $D_2$-antagonist, the CA secretory responses evoked by ACh, high potassium, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid considerably recovered as compared to that of bromocriptine only. Taken together, these results suggest that bromocriptine can inhibit the CA secretion evoked by stimulation of cholinergic receptors, as well as by membrane depolarization, in the perfused rat adrenal medulla. It is thought this inhibitory effect of bromocriptine may be mediated by inhibiting the influx of extracellular calcium and the release from intracellular calcium stores, through the activation of dopaminergic $D_2$-receptors located in the rat adrenomedullary chromaffin cells. Furthermore, these findings also suggest that the dopaminergic $D_2$-receptors may play an important role in regulating adrenomedullary CA secretion.

한국·일본의 대 아시아지역 직접투자 특성의 비교분석 (A Comparative Analysis on the Characteristics of ODI by Korean and Japanese Firms into Asian Continent)

  • 김성기;채두병;강한균
    • 국제지역연구
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    • 제14권3호
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    • pp.267-289
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    • 2010
  • 본 연구는 아시아지역에서의 한국과 일본의 대 아시아지역 직접투자의 특성을 거시적 측면과 미시적 측면으로 구분하여 분석하였다. 거시적 측면에서는 시장지향적 특성과 생산효율지향적 특성이 강한지를 다중회귀분석으로, 미시적 특성으로는 투자유형(합작 단독)과 투자규모, 노동집약도, 임금, 본사 파견 노동자 비율 등의 관계를 로지스틱회귀분석으로 분석하였다. 대체로 한국은 시장지향적 및 생산효율지향적 특성에서 2000년 이후 대체로 시장지향적 특성으로 전환되었고 일본은 생산효율지향적 특성에서 2000년 이후 대체로 시장지향적 및 생산효율지향적 특성으로 전환되었다. 한편 투자유형면에서는 한국과 일본 모두 GDP가 증가할수록, 파견노동자의 비율이 높을수록 단독투자를 선호하는 경향이 높은 것으로 나타났다. 한국은 투자규모가 클수록 현지임금이 높을수록 합작투자를, 일본은 자본집약도가 높을수록 단독투자를 선호하는 것으로 나타났다.

Cyclophosphamide에 의해 유도된 면역 저하 마우스에서 흑미 (Oryza sativa L.) 호분층의 면역 활성 효과 (Effects of Black rice (Oryza sativa L.) Aleurone layer on Cyclophosphamide-induced Immunosuppression in Mice)

  • 이은별;최지혜;김시현;장환희;이성현
    • 생약학회지
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    • 제52권3호
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    • pp.170-176
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    • 2021
  • Anthocyanins are considered as one of the major functional components including cyanidin-3-glucoside and peonidin-3-glucoside anthocyanins of black rice (Oryza sativa L., BR) aleurone layer (OAL) extract. The immunomodulatory biological effects of OAL has rarely been evaluated. This study has extensively studied the immunomodulatory effects of BR in immunosuppressed mice by CPA. The immunostimulatory effects of BR extract in in vivo at 150 (OAL-1) and 300 mg/kg body weight (OAL-2) for OAL groups were measured and compared to the normal group (CON) ingested with distilled water only or other groups. After the 14 days of oral administration, immune related organ weights, serum immunoglobulin (Ig) A and IgG, and cytokines (IL-12, TNF-α) levels, splenocytes proliferation rate, and NK cell activity were evaluated as immune related biomarkers. The serum IgA and IgG values in the OAL-treated groups increased to the level of the CON. OAL significantly and effectively controlled the IL-12 and TNF-α levels and NK activity compared to the negative control (NC) group. The results suggest that BR aleurone layer with immunomodulatory activities has a great potential as a functional food by itself or as a supplement.

AHP를 이용한 외식프랜차이즈 가맹본부의 지원서비스의 중요도 및 경쟁력 분석 (Analysis on the Importance and Competitiveness of Support Services of the Food Service Franchise Headquarters AHP Technique)

  • 최채봉;이상석
    • 한국프랜차이즈경영연구
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    • 제10권4호
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    • pp.7-18
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    • 2019
  • Purpose: This study identifies the relative importance of the sub - factors of initial services and continuous services using AHP (Analytic Hierarchy Process) method, and calculates the competitive index for the detailed factors. The purpose of this paper is to propose the establishment of long - term and short - term management strategy for expansion of business of food service franchise, franchisors, long - term and win - win relationship with franchisees, and rationalization of operating system. Research design, data, and methodology: The population for the survey is 92 franchisees in 46 foreign brands and 46 domestic brands in the Seoul metropolitan area (Seoul / Gyeonggi / Incheon). The survey was conducted from July 1 to August 31, 2018 through the survey agency with a telephone interview and a surveyor's direct visit. A total of 100 questionnaires were collected, but a total of 92 parts were used for analysis except 8 parts that were considered to contain false information. Using the AHP method, relative importance and competitiveness index were calculated for the details of initial services and continuous services. Results: The results shows continuous services were significantly higher for both foreign brand franchises, domestic brand franchises, and overall than initial services, This suggests that the continuous services of the affiliated franchisors has a higher relative importance than the initial services. Among the continuous services, brand reinforcement and promotion were significantly higher for both foreign brand merchants and domestic brand franchises. This can be regarded as the most important factor in brand reinforcement and promotion when selecting a food service franchisors. Conclusions: In the Standard Terms and Conditions governed by the Fair Trade Commission, the franchisors should increase the fairness by creating manuals for supporting services, especially after opening, and regularly checking whether the supporting services have been carried out like manuals since the establishment of franchisees. In addition, the Brand Strengthening and Public Relations Committee (tentative name) jointly participated by the franchisors and franchisees for the purpose of strengthening and promoting the brand, suggesting a system for transparent and efficient execution of the brand reinforcement and promotion budget and monitoring afterwards.

CPA 시스템 구성을 위한 고효율 투과형 유전체 회절격자 설계 (Design of High Efficiency Transmission Dielectric Grating for Chirped Pulse Amplification)

  • 조현주;정재우;이상현;김수종;이정섭;진대현;정지호;손승현
    • 한국광학회지
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    • 제33권6호
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    • pp.260-266
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    • 2022
  • 2개의 결합층과 2개의 격자 층으로 구성된 회절격자 구조를 형성하고, 최적화 기법을 통하여 -1차에서 높은 투과 회절 효율을 가지는 회절격자를 설계하였다. 설계된 회절격자는 설계 중심파장에서 99.997%의 transverse electric wave 회절 효율을 가지고 있었으며, 95% 이상의 회절 효율을 유지하는 파장 폭이 80 nm이고 입사각 폭이 20.0°이었다. 회절격자 공차 분석을 수행하여 95% 이상의 회절 효율을 가지기 위한 두께 공차가 최소 60 nm 이상 확보되어 있고, 내부각도 10° 이내의 사다리꼴 모양에서도 회절 효율을 유지할 수 있음을 확인하였다.