간단한 인증키 동의 프로토콜인 Kim-Kim-Hwang 방법의 안전성 고찰

김윤정;김영신;황준 서울여자대학교 컴퓨터과학연구소 2004 정보기술논문지 Vol.2 No.-

The Diffie-Hellman Key Exchange scheme can produce a common session key between the two communicators, but its problem is that it makes a man-in-the middle attack possible. To solve problems like these, several protocols have been put forward, and the Simple Authenticated Key Agreement (SAKA) Protocol is among them. Seo-Sweeney suggested a SAKA protocol initially and the protocol has weakness that a malicious 3rd party can masquerade a valid user. Tseng suggested another protocol that advances this problem but this protocol can still be attacked when the messages in key verification phase are identical. Ku-Wang suggested a new protocol that advances this problem. Kim-Kim-Hwang also suggested a new SAKA protocol and confirmed that their protocol has same safeness and better performance compared to the other SAKA protocols. In this paper, we reanalyze the safeness of SAKA protocols and find out that Kim-Kim-Hwang protocol has not only better performance but also better safeness. Diffie-Hellman의 키 인증 기법에 대한 제 3자 공격 (man-in-the middle attack)에 강한 간단한 인증키 동의 프로토콜인 SAKA (Simple Authenticated Key Agreement Protocol)가 제안된 바 있다. SAKA는 초기에 Seo-Sweeney에 의해 제안되었으며 이 방법은 침입자가 중간에 메시지를 가로채서 정당한 사용자임을 가장할 수 있는 단점이 있다. Tseng은 이 단점을 개선한 방안을 제안하였는데 이것도 키 확인 메시지 두 개의 값이 같을 경우 공격을 받을 수 있음이 밝혀졌다. Ku-Wang은 Tseng 방법의 문제점을 개선한 알고리즘을 제안하였다 그리고 Kim-Kim-Hwang은 새로운 SAKA 알고리즘을 제안하고 이것이 기존 SAKA 프로토콜들과 안전성은 동일하면서도 성능이 개선된 것임을 밝힌바 있다. 본 논문에서는 안전성 분석의 재고찰을 통하여, Kim-Kim-Hwang의 방법이 기존 SAKA 프로토콜들보다 성능면에서뿐만 아니라, 안전성 면에서도 우수함을 밝힌다.

Age-dependent differences of treadmill exercise on spatial learning ability between young- and adult-age rats

Jun-Jang Jin,Il-Gyu Ko,Sung-Eun Kim,Lakkyong Hwang,Man-Gyoon Lee,Dae-Young Kim,Sun-Young Jung 한국운동재활학회 2017 JER Vol.13 No.4

Trigger point를 利用한 口眼괘斜 患者 10例에 대한 臨床的 考察

鄭榮敦,李浚龜,金永一,朴泰均,辛泳一,黃載然,李賢,李秉烈 대전대학교 한의학연구소 2002 한의학연구소 논문집 Vol.10 No.2

From July 1th 2001 to October 31th 2001, the Clinical investigation studies were carried out 10 cases of patient with Bell's palsy using Trigger point treatment group, who had been treated in Han-seung Oriental Medical Clinic. The results were like below : 1. The distribution of sex : Male were 4cases, female were 6case and the female to male ratio was 1.5 : 1. 2. The distribution of contributing factor : Unknown reason was most predominant 4 cases, and then were revealed to labor too hard, menttal stress(3 cases), trauma·common cold(1 case) in turn. 3. The distribution of perid to fall ill : Under a week was the most number 6cases, and then were revealed a week under two weeks(3 cases), over two weeks(1 case) in turn. 4. About period of treatment : The Trigger point treatment group is shorter than the Acupuncture treatment group. 5. The distribution of grade on admission in descending order : GrⅠ was the most number and then GrⅡ, GrⅢ in turn. 6. The distribution of clinical symptoms on adimission : Mastoid pain was the most number 9 cases and then lacrimal gland disorder 8 cases, dysgeusia 4 cases, hyperacusis 2 cases, the others 2 cases in turn. 7. About effect of treatment : The Trigger point treatment group is more excellent than the Acupuncture treatment group. 8. The more patient age is young, the more effect of treatment was excellent, had nothing to do with both groups. 9. The more perid to fall ill is short, the more effect of treatment was excellent, had nothing to do with both groups. 10. About period of improved frontal belly : The Trigger point treatment group is more excellent than the Acupuncture treatment group.

Increased 11β-hydroxysteroid dehydrogenase type 1 contributes to barrier dysfunction in aged skin

( Beom Jun Kim ),( Noo Ri Lee ),( Chung Hyeok Lee ),( Young Bin Lee ),( Solam Lee ),( Hyun Jee Hwang ),( Eunjung Kim ),( Eung Ho Choi ) 대한피부과학회 2019 대한피부과학회 학술발표대회집 Vol.71 No.2

Background: 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) converts inactive cortisone into cortisol, an active form, and is expressed by several tissues including the skin. Excessive active glucocorticoid (GC) deteriorates skin barrier function. Objectives: To find out if 11β-HSD1 affects on the barrier function in aged skin. Methods: We have performed human and in vivo studies. We measured cortisol in stratum corneum (SC) and oral epithelium of the elderly and young. Hairless mice were used for 11β-HSD1 immunohistochemistry staining of skin and measuring skin barrier function and serum cytokines. 11β-HSD1 knock-out (KO) mice and its wild-type were used for measuring lipid synthesis related enzyme. Results: Cortisol levels were elevated in SC and oral epithelium of the elderly rather than young. The 11β -HSD1 expression was increased in immunohistochemistry stain of aged mice skin. Aged mice showed decreased transepidermal water loss (TEWL) and SC hydration, and increased SC integrity than young. Serum inflammatory cytokines including interleukin-1α, -4, -10, -31 and tumor necrosis factor-α were increased in aged mice than young. The expressions of lipid synthesis related enzymes in epidermis were elevated in KO mice and topical 11β -HSD1 inhibitor applied mice. Conclusion: 11β-HSD1 expression is elevated in aged skin. It increases active GC and then deteriorates skin barrier function.

대동맥 협착증과 동반된 출혈성 위장관 동정맥 기형에서 Estrogen-Progesterone 치료 1예

김도연,김화정,김효정,남준식,박수영,박영미,신정은,주미순,황민규,정혜경,손혜영,이선영,이한주 大韓消化器內視鏡學會 1999 Clinical Endoscopy Vol.19 No.부록2

[논문]회분식 화학공정의 공정감시를 위한 자동화 시스템 개발

안영준,안대명,황규석 釜山大學校生産技術硏究所 2003 生産技術硏究所論文集 Vol.62 No.-

현재 대부분의 국내 화학 공장 에서는 반응기의 자동 제어를 위해서 PLC(Prograrnmable Logic Controller)를 사용하고 있지만 성능에 비해 고가라는 단점이 있다. 이에 반해,16bit Micro- controller 인 80C196KC는 CPU, 입 · 출력장치 둥이 One Chip에 내장되어 있으므로 소형이며, 가격 대 성능비가 뛰어나 중 · 소형 화학반응 공정의 자동 제어에 적합하다고 할 수 있다. 본 연구에서는 다양한 산업분야의 자동화에 사용되고 있는 INTEL사의 16bit Microcontroller인 80C196KC를 사용하여 회분식 화학반응기의 자동화 시스템을 개발하고, 또 인터넷을 이용하여 원격감시와 제어가 가능하게 하였다.

용사코팅용 나노 WC-12Co 피드스톡의 제조

전형우,김주선,박준영,박종구,황순영,이해원 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.4

This study investigates the fabrication of WC-12Co feedstock powders with weakly locculated slurries by spray drying under various conditions. The morphological defects and flocculation states according to the amount of additives are evaluated to prepare spherical WC-Co feedstock powders with little morphological defects and homogeneous microstructures. The characteristics of feedstock powders, heat treated between 850-1200℃, are analyzed via SEM, EPMA, and mercury porosimetry. The results showed that with the increase in heat treatment temperature the portion of larger pores around 10 μm increased while, that of smaller pores of 1 μm lessened due to the coalescence of WC particles, forming dense feedstock powders with little defects such as hollow or craters. The feedstock heat treated at 1200℃ showed a porosity of 42.2% and a density of 8.28 g/cm^(3) as well as uniform distribution of pores and Co. (Received January 19, 2004)

FDM에서 경사면의 표면과 면적오차법의 관계에 대한 연구

전재억,정진서,황영모,김수광,김준안,계중읍,하만경 한국공작기계학회 2002 한국공작기계학회 추계학술대회논문집 Vol.2002 No.-

In any rapid prototyping process, the layer by layer building process introduces an area error between the staircase and the surface line specified by the computer-aided design model. This affects the dimensional accuracy as well as the surface finish for different part build orientations. This paper describes a methodology for computing the area error for any orientation of the part built by the fused deposition modelling system. This technique can be applied to determine the best build orientation of the part, based on the minimum area error. This technique is verified by comparing the results with the experimental measurements of the area error of the parts built at different orientations.

두가지 혈류 유발방법에 의한 새로운 심폐소생술(이중 혈류 유발 심폐소생술)장치의 개발

황성오,김현,조준휘,오범진,임종천,최경훈,윤정한,이승환,김영식,이강현,이윤선 大韓應急醫學會 1999 대한응급의학회지 Vol.10 No.2

Background: There have been many efforts to augment blood flow during cardiopulmonary resuscitation. These efforts have focused on maximizing the effect of cardiac pump or thoracic pump alone. However, considering that the heart is the biggest blood reservoir and increase of intrathoracic pressure can generate blood flow, simultaneous exploitation of both mechanisms may have synergistic effect. We hypothesized that simultaneous chest constriction in addition to sternal compression by standard CPR may have additive hemodynamic effects by preventing deformation of the chest and increase of intrathoracic pressure. Methods and results: we built a new mechanical device to perform compression and thoracic constriction simultaneously. The device consists of two main elements. Piston in the center is to depress the sternum. Strap is to constrict the thorax circumferentially. Strap is attached to both sides of the piston. When the piston is pushed down, it depresses the sternum and pulls on the thoracic strap. To determine strap width to produce optimal hemodynamic effect, we measured hemodynamic parameters with variable widths of strap in two dogs after induction of ventricular fibrillation. Result of the experiment showed that 10cm wide strap was determined to be most effective. We also determined optimal depth of compression to produce maximal hemodynamic effect with animal experiments using two dogs. Animal experiments showed that the highest aortic pressure could be generated when the stemum was depressed to 5 cm. Cardiopulmonary resusciation using a new device could generate higher systolic aortic pressure, coronary perfusion pressure and end-tidal carbon dioxide tension in comparison with standard cardiopulmonary resuscitation in a pilot animal study using two dogs. Conclusion: New cardiopulmonary resuscitation method using a mechanical device designed by us could perform sternal compression and simultaneous thoracic constriction, and generate better hemodynamic effects than standard cardiopulmonary resuscitation in pilot animal experiments.

등줄쥐의 대뇌겉질에 분포하는 NADPH-diaphorase와 Neuropeptide Y 양성반응신경세포에 관한 연구

허영범,황승준,조정식 대한해부학회 1997 Anatomy & Cell Biology Vol.30 No.1