특징점 매칭을 이용한 O2O 상점에서의 상품명 인식

김대민(Daemin Kim),시종욱(Jongwook Si),김성영(Sungyoung Kim) 한국컴퓨터정보학회 2024 한국컴퓨터정보학회 학술발표논문집 Vol.32 No.1

방사성 세슘 및 요오드의 제거를 위한 alginate 기반의 organo clay가 함침된 듀얼 흡착제 개발

김복성(Bokseong Kim),강성원(Sungwon Kang),김영석(Youngsug Kim),유성종(Sungjong Yoo),오대민(Daemin Oh) 대한환경공학회 2020 대한환경공학회 학술발표논문집 Vol.2020 No.11

불소계 플라즈마에 노출된 Al₂O₃의 미세구조 변화

김대민,이성민,김성원,김형태,오윤석,Kim, Dae-Min,Lee, Sung-Min,Kim, Seong-Won,Kim, Hyung-Tae,Oh, Yoon-Suk 한국세라믹학회 2008 한국세라믹학회지 Vol.45 No.7

Ceramics are widely used as plasma resistant materials in semiconductor industries. However, the plasma erosion resistance has not been properly evaluated in terms of microstructural changes during the exposure to plasma. In this study, microstructure developments of $Al_2O_3$ were investigated under the fluorine plasma conditions. In polycrystalline alumina, uniform erosion throughout the specimen as well as spatially distributed local erosion were observed. Local erosion was much more severe in lower purity alumina. In contrast to the polycrystalline alumina, only uniform erosion was observed in single crystalline sapphire. These specimens, however, had practically the same erosion depth, which results in the incorrectly similar plasma resistance. This implies that the plasma erosion resistance of ceramics should be evaluated in terms of the microstructural changes, as well as the conventionally accepted erosion depth.

객체 검출 기반의 상품 위치 계산과 이미지 유사도 측정을 통한 상품명 인식

김대민(Daemin Kim),시종욱(Jongwook Si),이상진(Sangjin Lee),김성영(Sungyoung Kim) 한국정보기술학회 2023 Proceedings of KIIT Conference Vol.2023 No.11

천연광물 흡착제 및 고염기도 PAC를 이용한 용존성 Cs의 처리특성

김복성(Bokseong Kim),김영석(Youngsuk Kim),정윤선(Yoonsuhn Chung),강성원(Sungwon Kang),오대민(Daemin Oh),채호준(Hojun Chae) 대한환경공학회 2017 대한환경공학회지 Vol.39 No.7

응집 침전기술인 방사능 오염물질의 처리장치의 용존성 Cs 처리특성을 평가하였다. 방사능 오염물질 처리장치는 전흡착부, 고형물침전부, 후흡착부로 구성하였다. 흡착제는 천연광물 일라이트를 입자크기에 따라 LPI (Large Particle Illite), SPI (Small Particle Illite)로 구분하여 사용하였고, 응집제는 고염기도 PAC (poly aluminum chloride)을 사용하였다. 흡착제는 판상구조형태로 주로 석영, 조장석, 백운모로 구성되었으며, LPI, SPI의 Surface area는 각각 4.201 m²/g, 4.227 m²/g으로 나타났고 입자크기는 각각 197.4-840.9 μm, 3.28-53.57 μm로 나타났다. 천연광물인 일라이트의 흡착효율은 LPI는 82.8%, SPI는 85.6%로 나타났고 흡착제 회수에 대한 간접적인 지표인 탁도의 제거율은 96.4%, 98.3%로 나타났다. This study investigated removal characteristic of soluble Cs in water by RPT (Radioactivity pollutant treatment) with coagulation and sedimentation. The RPT conducted with various chemical and natural coagulants to remove the soluble Cs which consisted pre-adsorption, Sedimentation and post-adsorption. Natural absorbent included Illite and zeolite. Especially, Illite divided LPI (Large Particle Illite) and SPI (Small Particle Illite) by grain size. Also, Chemical coagulants included high basicity PAC (poly aluminum chloride). The adsorbent had a plate structure mainly composed of quartz, albite and muscovite. The surface area were 4.201 m²/g and 4.227 m²/g and the particle sizes were 197.4-840.9 μm and 3.28-53.57 μm, respectively. The adsorption efficiency of the natural Illite was 82.8% for LPI and 85.6% for SPI. The removal efficiency of turbidity, which was an indirect indicator of adsorbent recovery, was 96.4% and 98.3%, respectively.

MFFM System을 이용한 손가락 별 파지 폭들의 변화에 따른 악력 및 개인 선호도에 대한 연구

김대민(Dae Min Kim),공용구(Yong?Ku Kong) 대한인간공학회 2008 大韓人間工學會誌 Vol.27 No.3

Individual finger/total grip forces, and subjective preferences for various individual finger grip spans (i.e., four fingers had identical grip spans or different grip spans) were evaluated by using an "Adjustable Multi-Finger Force Measurement (MFFM) System". In this study, three grip spans were defined as follows: a 'favorite grip span' which is the span with the highest subjective preference; a 'maximum grip span' which is the span with the highest total grip force; a 'maximum finger grip span' which is a set of four grip spans that had maximum finger grip forces associated with the index, middle, ring, and little fingers, respectively. Ten males were recruited from university population for this study. In experiment I, each participant tested the maximum grip force with five grip spans (45 to 65㎜) to investigate grip forces and subjective preferences for three types of grip spans. Results showed that subjective preferences for grip spans were not coincidence with the performance of total grip forces. It was noted that the 'favorite grip span' represented the lowest total grip force, whereas the 'maximum finger grip span' showed the lowest subjective preferences. The individual finger forces and the average percentage contribution to the total finger force were also investigated in this study. The findings of this study might be valuable information for designing ergonomics hand-tools to reduce finger/hand stress as well as to improve tool users' preferences and performance.

시체 손 실험연구를 이용한 손 내부 건의 힘과 외부 악력과의 관련성 연구

김대민(Dae-Min Kim),공용구(Yong-Ku Kong),최경희(Kyeong-Hee Choi) 대한인간공학회 2020 大韓人間工學會誌 Vol.39 No.5

Objective: The purpose of this study was to investigate the relationship between internal tendon exertion and external total grip strength through the cadaver hands experiment. Background: Many previous studies have been conducted to accurately measure the strength of the internal muscles of the human body, but there have been many difficulties in research, including the supply and demand of cadaver hands and the establishment of systems for data collection. Method: The donated four fresh cadaver hands were used, and the Cadaver Finger Force Measurement (CFM) system was developed to control the strength of the hand muscles. Grip span (4 levels: 45, 50, 55, 60mm), total tendon force (3 levels: 70, 105, 140N), and tendon force ratio (1:1, 1:1.5, 1:2, 1:3) were selected as independent variables, and total grip strength and internal tendon force/external force ratio (I/E ratio) were selected as dependent variables. Results: Grip span 55 and 60mm had a total grip strength of 28.8N and 27.5N, respectively, showing a relatively larger (approximately 15%) than 24.7N and 24.3N of 45mm and 50mm, respectively. The total grip strength for tendon forces showed the lowest total grip strength (19.0N) at 70N and the largest total grip strength (33.7N) when increased to 140N tendon force. The I/E ratio according to grip span was low in 55mm and 60mm grip span, and the ratio was relatively high in 45mm and 50mm grip span. The I/E ratio based on total tendon was the lowest (3.9) at tendon force of 70N and the highest at tendon force of 4.5 at 140N. Conclusion: It was confirmed that the external force of the hand grows together as the internal force (tendon exertion) increases, and that the rate of increase also depends on the magnitude of the external force. Application: The findings of this study provide useful insights and information for understanding the relationship between the external force of the hand and the force of the internal muscles that exert various grip or force.

불소계 플라즈마에 노출된 YAG 세라믹스의 식각거동 및 XPS 분석

김경범,김대민,이정기,오윤석,김형태,김형순,이성민,Kim, Kyeong-Beom,Kim, Dae-Min,Lee, Jung-Ki,Oh, Yoon-Suk,Kim, Hyung-Tae,Kim, Hyung-Sun,Lee, Sung-Min 한국세라믹학회 2009 한국세라믹학회지 Vol.46 No.5

Chemical composition and status of chemical bonding of the YAG($Y_3Al_5O_{12}$) ceramics after the exposure to fluorine plasma have been investigated using X-ray photoelectron spectroscopy, with the analysis on its erosion behavior. On the surface, F showed the maximum content, decreasing with depth, meanwhile the cation composition remained almost constant, irrespective of the position. The peaks due to Y in the reaction layer consisted of two kinds, showing the Y-O and Y-F bonds. These surface modifications under fluorine plasma seem to promote the erosion of the YAG ceramics. Excess addition of $Al_2O_3$ or $Y_2O_3$ into stoichiometric YAG produced 2nd phases of $Al_2O_3$ and $YAlO_3$, respectively, resulting in the slight difference in the local erosion rates. But, the overall average erosion rate was not sensitive to such excess additions of $Al_2O_3$ or $Y_2O_3$.

악력계 비교 분석 연구

김대민(Deamin Kim),김선옥(Sunok Kim),박진만(Jinman Park),김형만(Hyungman Kim),공용구(Yongku Kong) 대한인간공학회 2021 대한인간공학회 학술대회논문집 Vol.2021 No.11

Objective: 본 연구의 목표는 본 연구진이 개발한 악력 측정기와 연구분야에서 다양한 목적으로 널리 사용되고 있는 악력 측정기와 상업적으로 판매하여 악력을 평가하는데 사용되는 악력 측정기를 비교 분석하고자 한다. Bac㎏round: 악력과 관련된 다양한 연구들이 진행되고 있는 가운데, 악력과 건강과의 상관관계에 대해 연구한 논문들이 대다수 존재한다. 국외 연구에선 노인의 악력과 뇌기능 일부의 상관관계에 대한 연구가 진행되면서 악력이 언어능력과 의사결정, 질병적으로는 뇌졸중이나 치매의 위험정도와 관련이 있다는 결과를 도출하였다. 또한, 국내 외 선행 연구들에 따르면, 50대~60대의 악력은 일반적인 건강과 비례하며, 뇌졸중 질환 유병율의 관계가 매우 높으며, 다양한 질병들과의 상관관계가 있는 것으로 나타났다. 본 연구에서 악력과 다양한 질병들과의 상관관계를 살펴보기 위해 각 손가락의 힘 측정이 가능한 악력 측정기를 활용하기에 앞서, 장비의 신뢰성을 점검하기 위하여 다음과 같은 연구를 진행하였다. Methods: 본 연구의 목적을 달성하기 위하여, 연구에서나 상업적으로 많이 사용되고 있는 장비 4가지를 선별하여, 본 연구진의 악력 측정기(K-force)와 함께 비교 분석하였다. 장비의 비교분석을 위해, 악력측정기를 고정시키고 악력 측정기에 힘을 일정하게 제공할 수 있도록 지그를 특수 제작하였으며, 지그에 장비들을 고정시키고 10~60㎏ 까지 차례대로 10㎏ 단위로 부하를 가하였다. ANOVA를 이용하여 부하에 따른 장비별로 측정된 힘의 유의한 차이를 살펴보았다. Results: 통계적 분석결과 K-force 악력기는 별로 제공된 부하(10~60㎏, 10㎏ 간격)와 통계적 유의한 차이가 없었음을 확인하였고, 몇몇 악력기 간에 통계적으로 유의한 차이가 발생하였다. Conclusion: 본 연구를 통하여, 연구진에서 개발한 악력 측정기(K-force)가 악력 및 각 손가락의 힘을 측정하기에 적합함을 알 수 있었으며, 각 악력기 별로 측정값에 차이가 발생한 이유는 손잡이의 모양이 다르기 때문인 것으로 나타났다. 또한, 각 악력 측정기별로 서로 다른 장, 단점을 보유하고 있음을 파악하여, 상황에 맞는 악력 측정기를 사용할 수 있게 되었다. Application: 추후, 본 연구의 결과를 토대로 K-force 악력측정기를 적극 활용하여 다양한 악력과 질병들과의 상관관계에 대해 연구를 하고자 한다.

EB-PVD법으로 코팅된 Y₂O₃의 내플라즈마 특성

김대민,윤소영,김경범,김희식,오윤석,이성민,Kim, Dae-Min,Yoon, So-Young,Kim, Kyeong-Beom,Kim, Hui-Sik,Oh, Yoon-Suk,Lee, Sung-Min 한국세라믹학회 2008 한국세라믹학회지 Vol.45 No.11

Plasma resistant nanocrystalline $Y_2O_3$ films were deposited on alumina substrates through the electron-beam PVD technique. Increasing substrate temperature to $600^{\circ}C$ resulted in the textured microstructures with significantly enhanced adhesion force of the coating to the substrate. During the exposure to fluorine plasma, erosion rate of the coated specimen was higher than that of a sintered yttria specimen, but significantly lower than that of a single crystalline alumina. Considering the adhesion and erosion behaviors observed in the coated specimen prepared at $600^{\circ}C$, the deposition technique appears effective in reducing contamination particles generated from the ceramic parts in the plasma environment.