개선된 전처리 과정을 이용한 지문 인식 시스템

이동욱,안도랑,이지원,Lee Dong-Wook,Ahn Do-Rang,Lee Jee-Won 한국융합신호처리학회 2006 융합신호처리학회 논문지 (JISPS) Vol.7 No.2

지문에 기반을 둔 인식시스템은 오래 전부터 사용되었다. 지문은 이미 잘 알려진 바와 마찬가지로 개개인이 서로 다른 특징을 가지고 있기 때문에, 가장 널리 사용되는 생체계측적인 특징의 하나이다. 그러나 지문 인식 시스템은 입력 지문 영상의 상태가 나쁜 경우 인식 성능이 크게 저하되는 치명적인 약점이 있다. 본 논문에서는 이런 문제점을 해결하기 위해 향상된 방향과 향상된 이진화 및 세선화 영상을 이용한 영상 향상 알고리즘을 전처리 과정에서 사용한다. 영상 향상의 목적은 입력 지문 이미지의 품질을 정확히 측정하고, 지문 영상의 융선과 골의 구조를 개선시키는 것이다. 또한 인식 속도를 향상시키기 위하여 색인 테이블을 사용한 융선의 방향 정보 추출 방법을 제안하였다. 제안한 지문 인식 시스템이 특징점 추출과 인식 성능에서 향상되었음을 실험을 통해서 확인할 수 있었다. Fingerprint-based verification system has been used for a very long time. Because of their well-known uniqueness and immutability, fingerprint is one of the most widely used biometric features. However, fingerprint identification system has such a critical weakness that the performance of verification is reduced drastically for a poor input fingerprint. In this paper, an image enhancement algorithm using enhanced direction and enhanced binary and aiming image is used to mitigate the problem in the preprocessing. The goal of image enhancement is to estimate the quality of input fingerprint image and to improve the clarity of ridge and valley structures of input fingerprint image. Also, a ridge orientation extraction method using index table is proposed to improve the speed of verification. It is shown by the experiments that proposed fingerprint verification system improves the minutiae extraction accuracy and performance of verification.

소아에서 유주비장에 대한 비장고정술

이동욱,김상윤,Lee, Dong-Wook,Kim, Sang-Youn 대한소아외과학회 1995 소아외과 Vol.1 No.1

Torsion of the wandering spleen is a rare condition especially in children. Unfortunately, splenectomy was the advocated treatment of choice for wandering spleen in many children up to 1985 in spite of the well-known possibility of overwhelming postsplenectomy sepsis. Because of the conclusive evidence of the vital function of the spleen in infection, indication of splenectomy have been revised and more attention has been paid to preserving the spleen where possible. We are presented a girl with splenic torsion, seen as a migratory abdominal mass and intermittent vague abdominal pain. Splenopexy by fixation of the spleen to the diaphragm and posterolateral peritoneum and the use of Avitene in the splenic bed was successfully performed. Complete fixation of the spleen was confirmed by ultrasound a year after this procedure was carried out. The clinical presentation, etiology, diagnostic procedures and management are discussed also.

비마토프로스트 점안 후 눈 주변 피부 색소침착이 발생한 환자에서 약물중단 후 경과

이동욱,Dong Wook Lee,M,D 대한안과학회 2007 대한안과학회지 Vol.48 No.8

Purpose: To evaluate the demographic and clinical characteristics of bimatoprost-induced periocular skin hyperpigmentation. Methods: The chart analyses of 16 patients in whom cosmetically noticeable periocular skin hyperpigmentation developed after starting bimatoprost therapy were reviewed. Data collated included age, medication history, dates of starting and stopping bimatoprost treatment, and the subjective assessment of the periocular hyperpigmentation at initial detection as well as follow-up visits. Periocular hyperpigmentation was graded using an arbitrary scale from 0 to 3. The number of days to the onset of hyperpigmentation and to pigment resolution was determined and their associations to demographic and other clinical parameters were analyzed. Results: Patients had variable grades of periocular hyperpigmentation at presentation (mean, 1.53±0.66). Bimatoprost-induced periocular hyperpigmentation appeared 1-10 (mean, 4.3±2.6) months after initiation of bimatoprost therapy. Resolution of skin hyperpigmentation was noted 2-10(mean 6.8±1.9) months after stopping bimatoprost treatment. There was a minor correlation(R=+0.19) between the number of days to resolution of hyperpigmentation and the number of days when bimatoprost was used. At 12 months after stopping bimatoprost treatment, 12 of the 13 patients had complete resolution of periocular hyperpigmentation. However, weak hyperpigmentation remained in one patient. Conclusions: Bimatoprost-induced hyperpigmentation is benign and reversible.

여과포 실패 예방 목적으로 베바시주맙 결막하 주사를 이용한 섬유주절제술 2예

이동욱,이대규,Dong Wook Lee,Dae-Gyu Lee 대한안과학회 2008 대한안과학회지 Vol.49 No.8

다각도의 에지 정보를 이용한 디인터레이싱

이동욱,강문봉,Lee, Dong-Wook,Kang, Mun-Bong 한국융합신호처리학회 2010 융합신호처리학회 논문지 (JISPS) Vol.11 No.2

디인터레이싱 방식은 일반적으로 화면 간 디인터레이싱과 화면 내 디인터레이싱으로 나뉜다. 화면 내 디인터레이싱에서 가장 보편적인 방식은 라인카피와 라인별 평균값을 취하는 선형적인 방식이다. 또한 ELA(Edge Based Line Average), ELA를 변형시킨 방식 등이 에지를 이용한 디인터레이싱 방식들이다. 하지만 선형적 보간법은 에지 블러링이나 계단현상을 발생시키고, ELA나 변형된 ELA를 이용한 방식은 특정방향에지 정보가 부족해서 다양한 형태의 에지 부분에서의 디인터레이싱이 좋지 못하다. 본 논문은 7방향의 에지 방향 보간법과 수평방향의 에지라인을 고려한 화면 내 디인터레이싱 방식을 소개한다. 기존 방식에서 나타나던 오브젝트의 계단현상을 최대한 줄여줌으로써 보다 낳은 화질을 보인다. Deinterlacing methods are usually divided into inter-field deinterlacing and intra-field deinterlacing. The most common method of intra-field deinterlacing is the linear method which uses line doubling or line averaging. There are also some edge-enhancement methods such as ELA(Edge Based Line Average) and modified ELA. However, the linear interpolation generates edge blurring or staircase artifacts. The methods using ELA or modified ELA show poor deinterlacing at various types of edges because of insufficient edge information in a certain direction. This paper presents an intra-field deinterlacing algorithm that considers the interpolation based on edges in 7 directions and an edge line in the horizontal direction. It demonstrates better picture quality by reducing the staircase phenomenon of object in the conventional methods.

자율이동로봇군의 협조행동을 위한 지역적 통신 방식에 있어서 정보전파 해석 및 카오스 현상 분석

이동욱,심귀보,Lee, Dong-Wook,Sim, Kwee-Bo 대한전자공학회 1999 電子工學會論文誌, S Vol.s36 No.6

자율분산로봇시스템에서 협조행동을 위한 로봇의 센싱과 통신 기능은 필수적이다. 일반적으로 대역적 통신시스템에서 로봇의 대수가 증가하면 통신자원의 제한과 정보의 범람이 발생한다. 따라서 이 경우 지역적 통신방법이 유리하다. 본 논문에서는 지역적 통신에 의한 정보의 전파를 해석하고 최적의 통신반경을 찾기 위한 3가지 방법을 제시한다. 또한 로봇이 정보를 획득하고 소실할 경우 발생하는 군의 카오스 행동을 피하기 위한 조건을 찾는다. The sensing and communication abilities of a mobile robot are essential to cooperative behavior in distributed autonomous robotic systems. In general, as the number of robot goes on increasing, the limitation of communication capacity and information overflow occur in global communication capacity and information overflow occur in global communication system. Therefore a local communication is more effective than global one. In this paper, we analyze information propagation mechanism based on local communication. To find an optimal communication radius, we propose three methods with different conditions. Also, to avoid chaotic behavior which occurs when a robot obtains and loses information, we find stable condition of information propagation.

수평원관속에 동심으로 놓여있는 얼음 봉의 융해현상에 관한 보험적 연구

이동욱,유상신,Lee, Dong-Wook,Yoo, Sang-Sin 대한설비공학회 1986 설비저널 Vol.15 No.2

The melting phenomena of horizontal cylindrical ice-bar immersed in water and air concentrically in the cylinder are experimentally investigated for the temperature range from $3.5^{\circ}C\;to\;2.5^{\circ}C$. The shapes of the melting ice-bar are recorded photographically by the shadowgraph method. The shadowgraphs of the melting ice-bar show that water adjacent to the bar flows upward for the temperature range from $3.5^{\circ}C\;to\;5.8^{\circ}C$ while above $5.8^|\circ}C$ the flow is downward direction. The local and average Nusselt numbers are obtoined with the recorded shadowgraphs and comparator. Melting shapes of the ice-bar in the air show the vortex motion in the bottom portion of the bar, whereas no vortex motion appears in the bottom portion when the bar is melted in the water.

Assay of Cytochrome P-450-dependent Testosterone Hydroxylases in Liver Microsomes of Rats

이동욱,박기현,Lee, Dong-Wook,Park, Ki-Hyun 생화학분자생물학회 1988 한국생화학회지 Vol.21 No.3

흰쥐 간 마이크로좀의 cytochrome P-450(P-450)에 의해 생성된 testosterone의 monohydroxy 대사물을 동시에 쉽게 정량할 수 있는 TLC 방법을 정립하였다. 이 방법을 이용하여 phenobarbital(PB)로 유도된 흰쥐 간 마이크로좀의 P-450에 의한 testosterone의 대사를 관찰하였다. 생성된 14종의 대사물이 확인되었고 그중 6종의 monohydroxy 대사물($2{\alpha}-$, $2{\beta}-$, $6{\alpha}-$, $6{\beta}-$, $7{\alpha}-$ 그리고 $16{\alpha}$-monohydroxytestosterone)을 정량하였다. 설정한 반응조건에서 이들 대사물의 생성은 P-450의 농도(1nmol/0.5ml 반응액 이하)에 따라 양호한 직선 관계 (r=0.9687-0.9999)와 재현성(C.V=$1.8{\pm}1.0%$)을 나타내었다. 또한 PB로 유도된 P-450에 의한 $2{\beta}$-monohydroxytestosterone의 생성은 대조군에 비해 2배로 증가된 반면$2{\alpha}-$와 $7{\alpha}$-monohydroxytestosterone의 생성은 오히려 48, 32%로 각각 감소되었다. 그러나 확인된 대사물의 총함량은 서로 비슷하였다. A rapid and one time determinable TLC method for the monohydroxytestosterones formed by microsomal cytochrome P-450(P-450) was established, and applying this method the activity of P-450-dependent testosterone hydroxylases was observed in liver microsomes of rats pretreated with phenobarbital(PB). The 14 testosterone metabolites were found on the TLC plate. The amounts of 6-monohydroxytestosterones ($2{\alpha}-$, $2{\beta}-$, $6{\alpha}-$, $6{\beta}$, $-7{\alpha}$-and $16{\alpha}$-OH-T) were determined. The formation of these metabolites showed a good linearity(r = 0.9687-0.9999) corresponding to the concentration of P-450 added up to about 1.0 nmol/min/reaction mixture, and an excellent reproducibility (C.V.=$1.8{\pm}1.0%$) when determined with 0.5 nmol P-450 in this assay system. The hydroxylation of testosterone to its $2{\beta}$-OH-T by PB-inducible P-450 was increased (2 fold), while $2{\alpha}-$ and $7{\alpha}$-OH-T was rather decreased to 48 and 32%, respectively, compared with those of uninduced one. The $6{\beta}$-OH-T was predominantly formed by uninducible and PB-inducible P-450, especially PB-inducible P-450 hydroxylated stereospecifically onto the C2-position of testosterone $(2{\alpha}/2{\beta}=1:3.8)$. However, the oxidation rates of testosterone to its $6{\alpha}-$, $6{\beta}-$ and $16{\alpha}$-OH-T, and the total amount of testosterone metabolites identified were not changed significantly by the administration of PB.

소나무 꽃가루에서 분리한 Trehalase 의 정제 및 성상에 관한 연구

이동욱,이희성,조성희 ( Dong Wook Lee,Hi Sung Lee,Sung Hee Cho ) 생화학분자생물학회 1981 BMB Reports Vol.14 No.2

Trehalose, the alpha-1, 1 linked disaccharide of glucose, occurs widely in nature. This sugar has been isolated from bacteria, yeast, fungi and a number of invertebrates, where it functions as reserve carbohydrate. Trehalase(α,α-trehalose 1-D-glucohydrolase, EC 3. 2. 1. 28. ) responsible for the hydrolysis of trehalose was isolated from pine pollen(Pinus densiflora Siebold) and purified 81 times by DEAE-cellulose column and Sephadex G-200 column chromatography. The activity of trehalase was measured by method of Lapp and Mason. The enzyme activity in pine pollen was detected 80.46% in cytosolic fraction, 4.09% in mitochondria) fraction and 10.33% in nucleic fraction. The pH optimum for enzymatic activity was found to be 5.4 and optimal temperature was 60℃ and the Km value for trehalose was estimated to be about 2. 56 × 10^(-3)M. The product of reaction was identited as D-glucose by paper chromatographic method. The trehalase activity was activated as much as 14∼17% by 1 × 10^(-4)M∼1 × 10^(-3)M concentration of Na^+, and 27∼15% by 1 × 10^(-5)∼1 × 10^(-4)M of Mg^(++), and the other cations(K+, Ca++) were tested for their abillity to replace Mg^(++), but none was effective. The molecular weight of trehalase was estimated to be approximately 70,000 by Sephadex G-200 gel filtration.

소나무 꽃가루에서 분리한 Trehalase의 정제 및 성상에 관한 연구

이동욱,이희성,조성희,Lee, Dong-Wook,Lee, Hi-Sung,Cho, Sung-Hee 생화학분자생물학회 1981 한국생화학회지 Vol.14 No.2

소나무 꽃가루를 파쇄하여 Hogeboom (1968)의 방법으로 세포의 각 분획을 분리하였다. 그리고 trehalase의 활성도를 측정하고 세포질 분획의 trehalase 를 ammonium sulfate에 의한 침전, DEAE-cellulose 및 Sephadex G-200 column chromatography를 행하여 정제하였으며 그 성상을 관찰하여 다음과 같은 결론을 얻었다. 1. 소나무 꽃가루에 있는 trehalase 는 cytosol에 약 80% 그리고 mitochondria에 약 4%, nuclei 에 약 10% 함유되어 있었다. 2. 소나무 꽃가루의 세포질 분획에서 이 효소를 81배 정제하였으며, 기질로는 trehalose에 대해서만 활성을 나타냈다. 3. 이 효소활성의 최적 pH 는 5.4였으며, 최적온도는 $60^{\circ}C$였다. 4. 이 효소의 기질에 대한 Km값은 $2.56{\times}10^{-3}M$이었다. 5. 반응 생성물이 glucose임을 paper chromatography에 의해 확인하였다. 6. 양이온이 이 효소에 미치는 영향은 $Na^+$이 $1{\times}10^{-4}{\sim}1{\times}10^{-3}M$농도에서 효소활성도를 약 14~17% 증가시켰으나, 농도의 증가에 따라 억제 현상이 증가되었다. 또 $Mg^{++}$ 경우에도 $1{\times}10^{-5}M{\sim}1{\times}10^{-4}M$ 농도에서 활성도가 27~15% 증가되었으나 농도의 증가에 따라 현저한 억제현상을 보였다. 7. $K^+$, $Ca^{++}$의 경우에는 같은 농도 범위에서 효소활성에 변화가 없었다. 8. 이 효소의 분자량은 약 70,000이었다. Trehalose, the alpha-1,1 linked disaccharide of glucose, occurs widely in nature. This sugar has been isolated from bacteria, yeast, fungi and a number of invertebrates, where it functions as reserve carbohydrate. Trehalase(${\alpha},{\alpha}$-trehalose 1-D-glucohydrolase, EC 3.2.1.28.) responsible for the hydrolysis of trehalose was isolated from pine pollen(Pinus densiflora Siebold) and purified 81 times by DEAE-cellulose column and Sephadex G-200 column chromatography. The activity of trehalase was measured by method of Lapp and Mason. The enzyme activity in pine pollen was detected 80.46% in cytosolic fraction, 4.09% in mitochondria) fraction and 10.33% in nucleic fraction. The pH optimum for enzymatic activity was found to be 5.4 and optimal temperature was $60^{\circ}C$ and the Km value for trehalose was estimated to be about $2. 56{\times}10^{-3}M$. The product of reaction was identited as D-glucose by paper chromatographic method. The trehalase activity was activated as much as 14∼17% by $1{\times}10^{-4}M{\sim}1{\times}10^{-3}M$ concentration of $Na^+$, and 27~15% by $1{\times}10^{-5}M{\sim}1{\times}10^{-4}M$ of $Mg^{++}$, and the other cations($K^+$, $Ca^{++}$) were tested for their abillity to replace $Mg^{++}$, but none was effective. The molecular weight of trehalase was estimated to be approximately 70,000 by Sephadex G-200 gel filtration.