Min-Hash를 이용한 효율적인 대용량 그래프 클러스터링 기법

이석주(Seok-Joo Lee),민준기(Jun-Ki Min) 한국정보과학회 2016 정보과학회논문지 Vol.43 No.3

그래프 클러스터링은 서로 유사한 특성을 갖는 정점들을 동일한 클러스터로 묶는 기법으로 그래프 데이터를 분석하고 그 특성을 파악하는데 폭넓게 사용된다. 최근 소셜 네트워크 서비스와 월드 와이드 웹, 텔레폰 네트워크 등의 다양한 응용분야에서 크기가 큰 대용량 그래프 데이터가 생성되고 있다. 이에 따라서 대용량 그래프 데이터를 효율적으로 처리하는 클러스터링 기법의 중요성이 증가하고 있다. 본 논문에서는 대용량 그래프 데이터의 클러스터들을 효율적으로 생성하는 클러스터링 알고리즘을 제안한다. 우리의 제안 기법은 그래프 내의 클러스터들 간의 유사도를 Min-Hash를 이용하여 효과적으로 추정하고 계산된 유사도에 따라서 클러스터들을 생성한다. 실세계 데이터를 이용한 실험에서 우리는 본 논문에서 제안하는 기법과 기존 그래프 클러스터링 기법들과 비교하여 제안기법의 효율성을 보였다. Graph clustering is widely used to analyze a graph and identify the properties of a graph by generating clusters consisting of similar vertices. Recently, large graph data is generated in diverse applications such as Social Network Services (SNS), the World Wide Web (WWW), and telephone networks. Therefore, the importance of graph clustering algorithms that process large graph data efficiently becomes increased. In this paper, we propose an effective clustering algorithm which generates clusters for large graph data efficiently. Our proposed algorithm effectively estimates similarities between clusters in graph data using Min-Hash and constructs clusters according to the computed similarities. In our experiment with real-world data sets, we demonstrate the efficiency of our proposed algorithm by comparing with existing algorithms.

청소년들의 최대 골량 향상을 위한 운동 가이드라인

민석기 ( Seok-ki Min ),오태웅 ( Taewoong Oh ),김상현 ( Sang Hyun Kim ),조진경 ( Jinkyung Cho ),정호연 ( Ho-yeon Chung ),박동호 ( Dong-ho Park ),김창선 ( Changsun Kim6 ) 한국운동생리학회(구 한국운동과학회) 2020 운동과학 Vol.29 No.1

PURPOSE: An increase in bone mineral density during adolescence increases resistance to fractures in older age. The Korean Society for Bone and Mineral Research and the Korean Society of Exercise Physiology developed exercise guidelines to increase the peak bone mass (PBM) in adolescents based on evidence through a systematic review of previous research. METHODS: Articles were selected using the systematic method, and the exercise guidelines were established by selecting key questions (KQs) and defining the effects of exercises based on evidence through a literature review for selecting the final exercise method. There were 9 KQs. An online search was conducted on articles published since 2000, and 93 articles were identified. RESULTS: An increase in PBM in adolescence was effective for preventing osteoporosis and fractures in older age. Exercise programs as part of vigorous physical activity (VPA) including resistance and impact exercise at least 5 to 6 months were effective for improving PBM in adolescents. It is recommended that resistance exercise is performed 10 to 12 rep·set^-1 1-2 set·region^-1 and 3 days·week^-1 using the large muscles. For impact exercises such as jumping, it is recommended that the exercise is performed at least 50 jumps·min^-1, 10 min·day^-1, and 2 days·week^-1. CONCLUSIONS: Exercise guidelines were successfully developed, and they recommend at least 5 to 6 months of VPA, which includes both resistance and impact exercises. With the development of exercise guidelines, the incidence of osteoporosis and fractures in the aging society can be reduced in the future, thus contributing to improved public health.

국내외 수용가 맞춤형 수력발전시스템 현대화개발 및 실증

오민환(Min-Hwan Oh),신기석(Ki-Seok Shin),임재황(Jae-Hwang Lim),윤여창(Yeo-Chang Yun),김현아(Hyun-Ah Kim),강석원(Seok-Won Kang),백종명(Jong-Myung Paik),이준용(Jun-Yong Lee) 대한전기학회 2017 대한전기학회 학술대회 논문집 Vol.2017 No.10

Cutting performance of tungsten carbide tools coated with diamond thin films after etching for various times

Kim, Jong Seok,Park, Yeong Min,Bae, Mun Ki,Kim, Chi Whan,Kim, Dae Weon,Shin, Dong Chul,Kim, Tae Gyu World Scientific Publishing Company 2018 Modern physics letters. B, Condensed matter physic Vol.32 No.20

<P>In this study, diamond thin films were deposited on tungsten carbide tools using surface-wave plasma-enhanced chemical vapor deposition (SWP-CVD). To eliminate the adverse effects of cobalt on the diamond deposition process, the cobalt was removed from the surface of the tools by etching with Murakami’s reagent for various times (30, 60, and 120 min). The cutting performance of the untreated and the diamond-coated WC tools was examined by performing cutting test on carbon fiber-reinforced plastic (CFRP). The results showed that all the diamond-coated tools exhibited great improvement on the durability and wear resistance compared to the uncoated one. In addition, the diamond-coated tool lift time is found to be proportional to the etching time. An increase more than twofold has been achieved when the etch time was increased from 30 min to 120 min.</P>

Production of Iron-Binding Peptides from Colostral Whey by Enzymatic Hydrolysis

Kim, Sang-Bum,Ku, Min-Jung,Cho, Won-Mo,Ki, Kwang-Seok,Kim, Hyeon-Shup,Nam, Myoung-Soo Korean Society for Food Science of Animal Resource 2010 한국축산식품학회지 Vol.30 No.6

Colostral whey prepared from colostrum (pooled from first six post-partum milkings) was heated for 10 min at $100^{\circ}C$ Heated colostral whey was incubated with 1% enzymes (protein equivalent basis) for 15, 30, 60, 90, and 120 min at $50^{\circ}C$. Papain, pepsin, trypsin, and alcalase produced different degrees of hydrolysis (DH), 10.66%, 12.42%, 10.83%, and 25.31%, respectively, at an incubation time of 120 min. The SDS-PAGE reveals that significant amounts of bovine serum albumin (BSA), ${\beta}$-lactoglobulin (${\beta}$-LG), and ${\alpha}$-lactalbumin (${\alpha}$-LA) survived papain digestion. In contrast, pepsin completely removed BSA but not ${\beta}$-LG present in heated colostral whey. Alcalase completely eliminated BSA, ${\beta}$-LG, and ${\alpha}$-LA. This differential hydrolysis was confirmed by reversed-phase HPLC analysis. Using ion-exchange chromatography, fraction-1 (F-1) was obtained from alcalase hydrolysate at a NaCl gradient concentration of 0.25 M. Reversed-phase HPLC chromatograms of alcalase F-1 showed numerous small peaks, which probably indicate that a variety of new peptides were produced. Iron content of alcalase F-1 was 28.94 ppm, which was the highest among all enzyme fractions, whereas iron content of colostral whey was 36.56 ppm. Main amino acids contained in alcalase F-1 were Thr (15.45%), Glu (14.12%), and Ser (10.39%). Therefore, alcalase can be used to generate good iron-binding peptides in heated colostral whey, and the resulting iron-binding peptides could be suitable as a value-added food ingredient for food supplements.

Production of Iron-Binding Peptides from Colostral Whey by Enzymatic Hydrolysis

Sang Bum Kim,Myoung Soo Nam,Kwang Seok Ki,Hyeon Shup Kim,Min Jung Ku,Won Mo Cho 한국축산식품학회 2010 한국축산식품학회지 Vol.30 No.6

Colostral whey prepared from colostrum (pooled from first six post-partum milkings) was heated for 10 min at 100oC. Heated colostral whey was incubated with 1% enzymes (protein equivalent basis) for 15, 30, 60, 90, and 120 min at 50oC. Papain, pepsin, trypsin, and alcalase produced different degrees of hydrolysis (DH), 10.66%, 12.42%, 10.83%, and 25.31%, respectively, at an incubation time of 120 min. The SDS-PAGE reveals that significant amounts of bovine serum albumin (BSA), β-lactoglobulin (β-LG), and α-lactalbumin (α-LA) survived papain digestion. In contrast, pepsin completely removed BSA but not β-LG present in heated colostral whey. Alcalase completely eliminated BSA, β-LG, and α-LA. This differential hydrolysis was confirmed by reversed-phase HPLC analysis. Using ion-exchange chromatography, fraction-1 (F-1) was obtained from alcalase hydrolysate at a NaCl gradient concentration of 0.25 M. Reversed-phase HPLC chromatograms of alcalase F-1 showed numerous small peaks, which probably indicate that a variety of new peptides were produced. Iron content of alcalase F-1 was 28.94 ppm, which was the highest among all enzyme fractions, whereas iron content of colostral whey was 36.56 ppm. Main amino acids contained in alcalase F-1 were Thr (15.45%), Glu (14.12%), and Ser (10.39%). Therefore, alcalase can be used to generate good iron-binding peptides in heated colostral whey, and the resulting iron-binding peptides could be suitable as a value-added food ingredient for food supplements.

태권도 돌려차기 시 기술 수준에 따른 몸통, 골반, 지지 다리의 운동학적 변인 비교

김재웅 ( Kim Jae-woong ),한기훈 ( Han Ki-hoon ),김제민 ( Kim Je-min ),이상우 ( Lee Sang-woo ),권문석 ( Kwon Moon-seok ),터틀노엘 ( Noelle J. Tuttle ) 국기원 2018 국기원태권도연구 Vol.9 No.1

이 연구의 목적은 태권도 돌려차기 시 기술 수준에 따른 몸통, 골반, 지지 다리의 운동학적 변인을 비교 분석하는 데 있다. 본 연구를 위해 블랙 벨트 소지자로서 기술 수준에 따라 중급자10명, 상급자 9명이 실험에 참여하였다. 3차원 동작 분석 시스템을 사용하여 골반, 몸통, 지지다리의 방향각을 산출하였다. Start, Toeoff, MKF, Max, Impact, Min에서 그룹 간의 평균 방향각을 비교하기 위하여 독립표본 t-검정을 하였다. MKF, Impact, Min에서 골반의 좌측 기울어짐 각도가 그룹 간의 유의한 차이가 나타났다. Start와 Max에서 지지 다리의 엉덩관절 굴곡 각도와 MKF에서 지지 다리의 엉덩관절 외전 각도 사이에 유의한 차이가 있었다. 이상의 결과를 볼 때, 상급자들은 푸쉬단계에서 엉덩관절의 굴곡 각도가 증가 되었고, MKF에서는 외전 각도가 감소하였다. 또한, 스트라이크 단계에서 골반의 좌측 기울어짐 각도는 감소하였다. The study purpose was to investigate skill level differences on trunk, pelvis, and supporting leg kinematics in a Taekwondo roundhouse kick. 10 intermediate and nine expert male black-belt holders executed roundhouse kicks at a target. Orientation angles of the pelvis, trunk, and supporting -thigh, -shank, and -foot were obtained through a three-dimensional video motion analysis. Orientation angles at Start, Toeoff, Maximum Knee Flexion(MKF), Impact, Maximum angle(Max), and Minimum angle(Min) were compared between groups using independent t-tests(p<.05). Significant differences between groups were found in the pelvis left lateral tilted position at MKF, Impact, and Min; significant differences were also found in the supporting hip joint flexed position at Start and Max, and abducted position at MKF. It was concluded that higher performers increased the hip joint flexion angle in the Push phase, decreased abduction angle at MKF, and decreased the pelvis left tilted angle in the Strike phase.

The relationship between aerobic capacity and the recruitment of activated sweat gland density with passive heating

( Tae Wook Kim ),( Jong Hyuck Kim ),( Nam Eun Bae ),( Hyung Seok Seo ),( Young Soo Baik ),( Jeong Beom Lee ),( Hun Mo Yang ),( Young Ki Min ) 한국운동영양학회 2012 Journal of exercise nutrition & biochemistry Vol.16 No.4

This study investigated whether the recruitment of activated sweat gland density during passive heating [immersion of the lower body into hot water, 41℃ for 30 min (PH), room temperature 23 ± 0.5℃ with 60 ± 3% relative humidity] is different in endurance-trained (Trainee), compared with that of untrained subjects (Control), as indicated by VO2max. Eight trainees and seven control female subjects (38.31 ± 4.91 ml·kg-1·min-1 and 31.8 ± 0.92 ml·kg-1·min-1, respectively, p < 0.01) were similar on all other physical characteristics. To compare the changes between the trainees and controls, serum cortisol and prolactin (PRL), tympanic temperature (TYMP), local activated sweat gland density (L-ASGD) and the mean whole body sweat loss volume (M-WBSLV) changes were measured after PH. The cortisol was significantly higher (p < 0.05) and the PRL tended to be higher in the Trainee than in the Control. The TYMP increased more in the Trainee than in the Control (p < 0.001). The L-ASGD showed a higher tendency in the Trainee than in the Control, there was a significant difference in the mean activated sweat gland density (p < 0.01) and the L-ASGD was significantly correlated with the VO2max (p < 0.001). The M-WBSLV was significantly higher in the Trainee (p < 0.001) and significantly correlated with the VO2max (p < 0.001). The results suggest that in humans, a high aerobic capacity is associated with a greater recruitment of activated sweat glands, whole body loss of volume and TYMP. Therefore, the decline in the heat loss responses, due to decrease in maximal oxygen consumption, may be masked by repeated endurance exercise training.

Interleukin-5 저해 활성 chalcone 화합물의 유효 입체 구조

이기철,김민석,P. Thanigaimalai,Vinay K. Sharma,박경래,김영수,정상헌 충남대학교 약학대학 의약품개발연구소 2010 藥學論文集 Vol.25 No.-

Interleukin(IL)-5 appears to be one of the main proinflammatory mediators among the growing number of cytokines and chemokines that induce eosinophilic inflammation. Previously, our group synthesized a number of chalcone derivatives to determine their inhibitory activity against IL-5. However, the structure-activity relationship (SAR) of these chalcones was somewhat unclear, robably due to presence of three free rotatable bonds. To further, explore the SAR of these chalcones, we synthesized eight 2-(benzylidene)-2,3-dihydroinden-1-ones and 2- benzylidene)-3,4-dihydronaphthalen-1(2H)-ones 6 and evaluated for their inhibitory activity against IL-5. These rigidified chalcones 6 exhibited very weak inhibitory activity against IL-5 compared to chalcones 2. The structures of 6 closely resemble to the stretched conformations of chalcone 2, not effective conformation for the inhibition on IL-5 function.

Tabes Dorsalis의 핵자기공명영상 및 전기생리학적 소견

권기한,김성민,권석범,이병철,조광호,주정희 대한신경과학회 1999 대한신경과학회지 Vol.17 No.3