흰쥐의 DMBA 와 tobacco tar도포및 악하선절제시 설암의 유인성에 관한 실험적 연구

김동열,조한국 慶熙大學校 齒科大學 1995 慶熙齒大論文集 Vol.17 No.1

The purpose of this study was to evaluate the effects of excisional wounding, tobacco tar, and removal of submandibular gland on the carcinogenesis induced by DMBA application of the tongue in Sprague-Dawley rats. Seventy-seven rats were divided into experimental group and control group(group 6), and experimental group is subdivided into five group. In group 1, the lateral border of middle third of the tongue was painted 3 times weekly with DMBA. In group 2, the same portion as above was painted with DMBA and proceeded one time weekly by excised with scissor. In group 3, the same portion as above was painted with DMBA and tar. In group 4, the same portion as above was painted with DMBA and tar, and proceeded excisional wounding in the lateral border of tongue. In group 5, the same portion as above was painted with DMBA and tar, and proceeded excisional wounding in the lateral border of tongue after removal of submandibular gland. In group 6, none was treated. At each 5,10,13,16 and 20 weeks after experiment, 2 animals in the each group 1,2,3,4, and 5, and 2 animals in the group 6 were sacrificed with ether, and then formalin-fixed paraffin-embedded sections were stained as H-E staining rountinely, Masson's trichrome staining for collagen fibers, and PAS staining for glycogen. The obtained results were as follows ; 1. In group 1,hyperkeratosis and hyperplasia at 5-10 weeks, and epithelial dysplasia at 16-weeks, carcinoma in situ at 20 weeks were observed, and in group 2 carcinogenesis was progressed more repidly than that of group 1 or group 3. 2. In group 4, carcinogenesis was progressed more repidly than that of group 2. In group 5, carcinoma in situ at 10-13 weeks, highly differentiated squarnous cell carcinoma at 16 weeks, and well differentiated squamous cell carcinoma at 20 weeks were onserved. 3. The chronic inflammatory response in the underlying connective tissue were observed and minor salivary glands were changed into pleomorphic or cystic degeneration, and in some portion, neuromatous proliferation was observed. 4. In group 4, carcinogenesis was observed predominantly in the lateral border of the tongue and faintly in entire mucosa of the tongue in some animals. In experimental chemical carcinogenesis of tongue in rats, we could find that excisional wounding accelerated the process of carinogenesis, and more rapidly progressed under the condition of xerostomia by proceeding application of DMBA and tar after sialadenectomy.

석탄폐석 및 광재의 유해물질 침출특성 연구

우영국,강성환,임재명,한동준,김병욱 강원대학교 석재복합신소재제품연구센터 1996 석재연 논문집 Vol.1 No.-

광산에서 배출되는 광재폐기물은 산과 계곡에 투기 또는 매립되어 강우등에 의하여 주변 소하천을 오염시키고 있다. 따라서 본 연구는 광재의 물리적특성과 이화학적 특성을 조사하고 회분식과 칼럼식실험을 수행하여 오염물질의 침출특성을 고찰하고자 하였다. 실험결과, 다음과 같은 결론을 얻을 수 있었다. 1) 광재는 점토질 및 실트질의 크기를 지니고 있으나 점착력과 소성적 성질이 없는 사질토의 특성을 지니고 있다. 2) 광재의 투수계수는 대부분 10(???)³-10(???)cm/sec의 범위이며, 일반 사질토의 투수계수보다 낮음을 알 수 있었다. 3) 회분식과 칼럼식 용출시험의 결과, 대상 광산의 광재폐기물 일부에서 기준치 이상의 중금속농도가 침출되었으며, 이에대한 방지대책의 심각성을 알 수 있었다. 4) 광재 폐기물의 칼럼식 용출시험 결과 kg폐기물 당 인공강우 투여량 비가 증가할수록 침출수의 중금속 및 유해물질 농도는 크게 감소되어 어느정도 진행된 이후부터는 대부분 일정한 농도가 유지되나, 산성강우시 침출정도 및 침출시간은 지속되는 것을 알 수 있었다. 5) 광재는 많은 중금속과 유해물질을 함유하고 있으나 양적인면에서 자원화의 가치가 높을 것으로 판단된다. 따라서 광재내의 자원회수, 건설 재료등의 재활용및 자원화 연구가 필요하다. Tailing wastes producedat metal mines have been disposed of by dumping or landfiling in depression. Mine drainage developed at pile of the tailing wastes has high concentrations of various kinds of heavy metals and harzardous materials, and these contaminants are leached out from the tailing wastes by water infiltration or when they collapse. In this study, both batch test and column test were performed in order to investigate the physical and leaching characteristics of tailing wastes. The batch test results were compared with those by EPT and DLT, and column test was carried out at acidic and neutral pH ranges. The results showed that high concentrations of heavy metals and sulfate were contained in the leachate of the some tailing wastes. In column test, levels of heavy metals in the leachate produced during the initial rainfall period were found higher.

만성신부전증 환자에서 Recombinant Human Erythropoietin 치료에 따른 혈액지표와 Hemoglobin A1c에 대한 연구

이세영,배성한,변동원,서교일,유명희,김극배 순천향의학연구소 1996 Journal of Soonchunhyang Medical Science Vol.2 No.2

Hemoglobin A1c is produced by a progressive, non-enzymatic reaction between glucose and hemoglobin within the erythrocytes. The HbA1c concentration is dependent on the plasma glucose level and the stage of development of the erythrocytes. Immature erythrocytes contain lower levels of glycosylated hemoglobin than mature erythrocytes. HbA1c level was decreased in short RBC life span. Therefore, HbA1c level is not only measure for assessment of moderate to long term glycemic status in diabetics, but also as a possible diagnostic parameter of anemia. The aim of this study was to evaluate the HbA1c level in patients with chronic renal failure with anemia. HbA1c concentration, iron, ferritin, TIBC and hematologic parameters were measured before treatment and 1, 2 months after administration of recombinant human erythropoietin. The HbA1c concentration was measured by high performance liquid chromatography with cation exchange column (Pharmacia). The results were as follows; 1. The mean of hemoglobin was 8.66 g/dL in the controls and 7.84 g/dL in the patients with chronic renal failure. The mean of hematocrit was 25.19 % in the controls and 23.14 % in the patients with chronic renal failure. The mean of MCV was 93.23 fL in the controls and 92.73 fL in the patients with chronic renal failure. The mean of MCH was 32.56 pg in the controls and 31.76 pg in the patients with chronic renal failure. The mean of HbA1c was 3.15 % in the controls and 2.95 % in the patients with chronic renal failure. 2. Hematologic parameters in the patients with chronic renal failure 1) The results of hemoglobins were 7.84 g/dL, 8.11 g/dL, 8.92 g/dL, the MCH were 31.76 pg, 32.87 pg, 33.20 pg, the results of MCV were 92.73 fL, 97.37 fL, 92.85 fL at before treatment and 1, 2 months after administration of r-HuEpo. 2) The results of hematocrits were 23.14 %, 23.73 %, 26.73 % at before treatment and 1, 2 months after administration of r-HuEpo. 3. Iron metabolism parameters in the patients with chronic renal failure 1) The results of iron test were 180.92 ㎍/dL, 137.79 ㎍/dL, 126.83 ㎍/dL at before treatment and 1, 2 months after administration of r-HuEpo. 2) The results of ferritin test were 1500.2 ng/ml, 1311.6 ng/ml, 1151.0 ng/ml at before treatment and 1, 2 months after administration of r-HuEpo. 3) The results of TIBC test were 282.17 ㎍/dL, 282.45 ㎍/dL, 278.83 ㎍/dL at before treatment and 1, 2 months after administration of r-HuEpo. 4. The results of HbA1c test were 2.95 %, 3.08 %, 3.18 % at before treatment and 1, 2 months after administration of r-HuEpo. It is suggested that, in patients with chronic renal failure, evaluation of HbA1c in diabetics who have anemia with chronic renal failure should be consider possible hematologic parameters, and HbA1c level would be one of the marker of anemia status, but further studies are needed.

Improved Computation of Square Roots in Specific Finite Fields

Dong-Guk Han,Dooho Choi,Howon Kim IEEE 2009 IEEE TRANSACTIONS ON COMPUTERS - Vol.58 No.2

<P>In this paper, we study exponentiation in the specific finite fields F, with very special exponents such as those that occur in algorithms for computing square roots. Here, q is a prime power, q = p<SUP>k</SUP>, where k > 1, and k is odd. Our algorithmic approach improves the corresponding exponentiation resulted from the better rewritten exponent. To the best of our knowledge, it is the first major improvement to the Tonelli-Shanks algorithm, for example, the number of multiplications can be reduced to at least 60 percent on the average when p= 1 (mod 16). Several numerical examples are given that show the speedup of the proposed methods.</P>

Some Explicit Formulae of NAF and its Left-to-Right Analogue Based on Booth Encoding

Dong-Guk Han,Okyeon Yi,Tsuyoshi Takagi 보안공학연구지원센터 2013 International Journal of Security and Its Applicat Vol.7 No.6

단순전력분석에 안전한 Signed Left-to-Right 리코딩 방법

한동국(Dong-Guk Han),김성경(Sung-kyoung Kim),김태현(Tae Hyun Kim),김호원(Ho Won Kim),임종인(Jongin Lim) 한국정보보호학회 2007 정보보호학회논문지 Vol.17 No.1

본 논문에서는 주어진 기수 r 표현법을 SPA에 안전하게 리코딩 하는 방법을 제안한다. 제안된 알고리즘들은 기존의 것들과는 달리, Left-to-Right 리코딩이 가능하도록 구성되어져 있기 때문에 최상위 비트부터 스캔하면서 스칼라 곱셈을 계산하는 알고리즘과 연동이 되어 질 경우, 추가 메모리 없이 쉽게 구현된다는 장점이 있다. 따라서 Left-to-Right 리코딩기법들은 메모리의 제약을 받는 장비인 스마트 카드, 센서 노드에 적합하다. This paper proposed recoding methods for a radix- r representation of the secret scalar which are resistant to SPA. Unlike existing recoding method, these recoding methods are left-to-right so they can be interleaved with a left-to-right scalar multiplication, removing the need to store both the scalar and its recoding. Hence, these left-to-right methods are suitable for implementing on memory limited devices such as smart cards and sensor nodes

랜덤한 덧셈-뺄셈 체인에 대한 부채널 공격

한동국(Dong-Guk Han),장남수(Nam-Su Chang),장상운(Sang-Woon Jang),임종인(Jongin Lim) 한국정보보호학회 2004 정보보호학회논문지 Vol.14 No.5

Okeya-Sakurai는 타원곡선 암호시스템에 대한 부채널 공격의 대응방법으로 소개된 Oswald-Aigner의 랜덤한 덧셈-뺼셈 체인(Randomized Automaton 1, 2) 대응방법 [18]이 SPA 공격에 취약함을 보였다. 그러나 본 논문에서는 Okeya-Sakurai의 공격 알고리즘 [15,16]에 두 가지 잠재된 문제가 있음을 보인다. 그리고 두 가지 문제점에 대한 해결책을 제시하고 [15,16,19]와는 다른 새로운 효율적인 공격 알고리즘을 제안한다. 표준에 제안되어 있는 163비트 비밀키를 사용하는 알고리즘에 본 논문의 분석방법을 적용해 구현한 결과, 단순한 형태의 랜덤한 덧셈-뺄셈 체인(Randomized Automaton 1)에서는 20개의 AD수열로 대략 94%의 확률로 공격이 성공하며 30개의 AD수열로는 대략 99%의 확률로 공격이 성공한다. 또한, 복잡한 형태(Randomized Automaton 2)에서는 40개의 AD수열로 94%의 확률로 70개의 AD수열로는 99%로의 확률로 공격이 성공한다. In [15,16], Okeya and Sakurai showed that the randomized addition-subtraction chains countermeasures [18] are vulnerable to SPA attack. In this paper, we show that Okeya and Sakurai’s attack algorithm [15,16] has two latent problems which need to be considered. We further propose new powerful concrete attack algorithms which are different from [15,16,19]. From our implementation results for standard 163-bit keys, the success probability for the simple version with 20 AD sequences is about 94% and with 30 AD sequences is about 99%. Also, the success probability for the complex version with 40 AD sequences is about 94% and with 70 AD sequences is about 99%.

마스킹 테이블을 사용하지 않는 AES, ARIA, SEED S-box의 전력 분석 대응 기법

한동국(Dong-Guk Han),김희석(HeeSeok Kim),송호근(Ho-geun Song),이호상(Ho-sang Lee),홍석희(Seokhie Hong) 한국정보보호학회 2011 정보보호학회논문지 Vol.21 No.2

전력 분석 공격이 소개되면서 다양한 대응법들이 제안되었고 그러한 대응법들 중 블록 암호의 경우, 암/복호화 연산도중 중간 값이 전력 측정에 의해 드러나지 않도록 하는 마스킹 기법이 잘 알려져 있다. 블록 암호의 마스킹 기법은 비선형 연산에 대한 비용이 가장 크며, 따라서 AES, ARIA, SEED의 경우 S-box에 대한 대응법을 효율적으로 설계해야만 한다. 하지만 기존의 AES, ARIA, SEED의 S-box에 대한 대응 방법은 마스킹 S-box 테이블을 사용하는 방법으로 하나의 S-box당 256 bytes의 RAM을 필수적으로 사용한다. 하지만 가용 RAM의 크기가 크지 않은 경량보안 디바이스에 이러한 기존의 대응법은 사용이 부적합하다. 본 논문에서는 이러한 단점을 보완하기 위해 마스킹 S-box 테이블을 사용하지 않는 새로운 대응법을 제안한다. 본 논문에서 제안하는 새로운 대응 기법은 비용이 적은 ROM을 활용, RAM의 사용량을 줄일 뿐 아니라 마스킹 S-box 테이블 생성 시간을 소요하지 않으므로 축소 라운드 마스킹 기법 적용 시 고속화도 가능하다. In the recent years, power analysis attacks were widely investigated, and so various countermeasures have been proposed. In the case of block ciphers, masking methods that blind the intermediate values in the en/decryption computations are well-known among these countermeasures. But the cost of non-linear part is extremely high in the masking method of block cipher, and so the countermeasure for S-box must be efficiently constructed in the case of AES, ARIA and SEED. Existing countermeasures for S-box use the masked S-box table to require 256 bytes RAM corresponding to one S-box. But, the usage of the these countermeasures is not adequate in the lightweight security devices having the small size of RAM. In this paper, we propose the new countermeasure not using the masked S-box table to make up for this weak point. Also, the new countermeasure reduces time-complexity as well as the usage of RAM because this does not consume the time for generating masked S-box table.

XTR 버전의 개인식별 프로토콜을 이용해 블랙메일링을 막는 실질적인 방법

한동국(Dong-Guk Han),박혜영(Hye-Young Park),박영호(Young-Ho Park),김창한(Chang-Han Kim),임종인(Jong-In Lim) 한국정보보호학회 2002 정보보호학회논문지 Vol.12 No.1

유한체 F<SUB>p<SUP>k</SUP></SUB>에서 효율적으로 제곱근을 구하는 알고리즘들

한동국(Dong-Guk Han),최두호(Doo Ho Choi),김호원(Howon Kim),임종인(Jongin Lim) 한국정보보호학회 2008 정보보호학회논문지 Vol.18 No.a6

본 논문에서는 확장체 Fp<SUP>k</SUP>(k 홀수) 에서 효율적으로 제곱근을 구하는 방법을 제안한다. 제곱근을 구하는 알고리즘은 표수 p의 조건에 따라서 여러 가지 방법들이 제안되었다. 특히, 알고리즘을 구성하는 중심 되는 연산 중의 하나가 지수승 연산이다. 본 연구에서는 기존의 제곱근을 구하는 알고리즘에 사용되는 지수승의 지수들이 표수 p을 활용한 p-진법으로 표현할 경우, 특별한 형태의 주기성을 가지는 표현으로 나타내어짐을 증명하고, 이것을 활용해 기존의 알고리즘들을 효율적으로 계선하는 방법을 제안한다. 본 논문에서 제안한 방법은 표수 p의 조건에 의존하지 않고, 지수승 기반의 기존의 모든 제곱근 알고리즘에 적용 가능하다는 장점을 가지고 있다. 지금까지 알려진 바로는, 본 논문이 처음으로 Tonelli-Shanks 알고리즘을 효율적으로 개선하였으며, p ≡1 (mode 16)인 경우 60% 이상의 효율성 증대가 있었다. 다른 제곱근 알고리즘에 적용한 결과들도 비교표들을 이용해 언급되어 있으며, 기존의 방법들에 비해 상당히 효율적임을 나타내고 있다. In this paper we study exponentiation in finite fields Fp<SUP>k</SUP>(k is odd) with very special exponents such as they occur in algorithms for computing square roots. Our algorithmic approach improves the corresponding exponentiation independent of the characteristic of Fp<SUP>k</SUP>. To the best of our knowledge, it is the first major improvement to the Tonelli-Shanks algorithm, for example, the number of multiplications can be reduced to at least 60% on average when p≡1(mod 16). Several numerical examples are given that show the speed-up of the proposed methods.