한국인 하악치아의 수평적인 위치관계에 관한 연구

최승민,최대균,최부병,Choi, Seung-Min,Choi, Dae-Gyun,Choi, Boo-Byung 대한턱관절교합학회 2003 구강회복응용과학지 Vol.18 No.2

It is very important to arrange the artificial teeth correctly in bucco-lingual (labio- lingual) relation in reconstrcting dentition. Although many anatomic landmarks and techniques have been reported over the years, they are based on westerns. So this study was performd to examine the horizontal relations of mandibular teeth in Korean dentulous adults. 200 volunteers(mean age 22.9) who had natural dentition were selected. The impressions were taken with irreversible hydrocolloid impression material and mandibular study models were fabricated using class I dental stone. Then they were measured with 3-dimensional measuring device specially designed for this study. The results were as follows ; It is better to consider the lingual cusps of the lower posterior teeth as a guide than the linguoaxial surfaces of the lower posterior teeth, arranging the lower posterior teeth buccally to the line which starts from the mesial aspect of the lower canine and continue backward to the lingual aspect of the retromolar pad. It is better to arrange the fossae of the lower posterior teeth buccally to the line which starts from the cusp tip of the lower canine and continue backward to the top of the retromolar pad. The positions of the lower posterior teeth in the denture-bearing area ; considering the fossa as a guide, the 2nd premolar was positioned in center. considering the buccal cusp as a guide, the 1st molar and the 2nd molar were positioned in center. the distance ratio(d/a) was incresed constantly from the lower canine to the 2nd molar d ; the distance between the buccal vestibule(the lowest point) and the buccal cusp tips of the lower posterior teeth. a ; the distance between the buccal vestibule(the lowest point) and the lingual vestibule(the lowest point). The lower canine was positioned lingually($0.11{\pm}0.13$) than the labial vestibule, and the central incisor and the lateral incisor were positioned almost in the imaginary perpendicular plane of the labial vestibule(the lowest point).

초음파 의료 영상에서 비집속 송신을 이용한 고속 음향 복사력 임펄스 영상법

최승민,박정만,권성재,정목근,Choi, Seung-Min,Park, Jeong-Man,Kwon, Sung-Jae,Jeong, Mok-Kun 한국음향학회 2012 韓國音響學會誌 Vol.31 No.3

초음파 의료 영상에서 탄성영상은 암과 같은 종양의 진단에 도움을 준다. 본 논문은 초음파 음향 복사력을 이용하여 관찰하고자 하는 연조직에 힘을 인가하여 탄성 영상을 구현하였다. 데이터 획득 시간을 줄이기 위하여 송신 집속을 하지 않고 버스트 (burst) 형태의 평면파를 송신하여 모든 영상 영역에 동시에 음향 복사력이 인가되도록 하였다. 균일 탄성팬텀을 이용한 실험에서 송신 집속을 하지 않고도, 송신 시간을 길게 함으로써 탄성 영상을 얻기에 충분한 음향 복사력을 얻을 수 있음을 확인하였다. 그러나 기존의 집속형 음향 복사력을 이용한 영상과는 다른 시간 대 변위 특성이 관찰되었다. 제안한 탄성 영상 기법으로 초음파 병변 탄성 팬텀과 소의 간 실험에서 병변을 구별할 수 있음을 확인하였다. In medical ultrasound imaging, elasticity imaging helps to diagnose tumors such as cancer. This paper is concerned with the application of acoustic radiation force to soft tissue of interest to implement elasticity imaging. In order to reduce the data acquisition time, instead of relying on transmit focusing, a plane wave of burst type is transmitted to apply the acoustic radiation force simultaneously to an entire imaging region to be observed. A homogeneous phantom experiment confirms that increasing the transmit excitation duration instead of employing transmit focusing generates a high enough acoustic radiation force to obtain elasticity images. It is found, however, that a different displacement versus time characteristic is observed unlike the case of using a conventional focused acoustic radiation force. Experimental results obtained through the use of an ultrasound phantom and a bovine liver show that lesions can be correctly differentiated.

로봇을 위한 운영체제 수준의 동적 전력 관리

최승민,채수익,Choi Seungmin,Chae Sooik 대한전자공학회 2005 電子工學會論文誌-SD (Semiconductor and devices) Vol.42 No.5

This paper describes a new approach for the operating system level power management to reduce the energy consumed in the IO devices in a robot platform, which provides various functions such as navigation, multimedia application, and wireless communication. The policy proposed in the paper, which was named the Energy-Aware Job Schedule (EAJS), rearranges the jobs scattered so that the idle periods of the devices are clustered into a time period and the devices are shut down during their idle period. The EAJS selects a schedule that consumes the minimum energyamong the schedules that satisfy the buffer and time constraints. Note that the burst job execution needs a larger memory buffer and causes a longer time delay from generating the job request until to finishing it. A prototype of the EAJS is implemented on the Linux kernel that manages the robot system. The experiment results show that a maximum $44\%$ power saving on a DSP and a wireless LAN card can be obtained with the EAJS. 본 논문에서는 가정용 로봇에 적용 할 수 있는 운영체제 수준의 동적 전력 관리 기법인 EAJS(Energy-Aware Job Scheduler)를 제안한다. EAJS는 workload가 일정하지 않은 IO 장치를 사용하는 job들을 스케줄하여 장치의 idle주기를 가능하면 연속적이게 만든 후, 장치를 shutdown 시켜서 에너지 소모를 줄이는 능동적인 저전력 스케줄러이다. EAJS는 기존의 저전력 스케줄러와 달리, IO 장치를 사용하는 job의 workload, job의 buffering에 사용 가능한 메모리의 크기, buffering으로 인해 발생하는 시간 지연 등을 동시에 고려하여 job을 스케줄 하기 때문에, 에너지를 절약하면서도 시스템의 성능 저하를 최소화 할 수 있다. EAJS의 prototype을 본 연구에서 개발한 가정용 로봇인 AFM(Autonomous Family Machine)에 구현하였으며, H.263 인코더를 수행시키는 실험을 통해 무선랜과 DSP의 에너지 소모가 최대 $44\%$ 가량 줄어듬을 확인 하였다.

마그네슘 티타네이트 표면의 조골세포 부착도와 분화

최승민,이재관,고성희,엄흥식,장범석,Choi, Seung-Min,Lee, Jae-Kwan,Ko, Sung-Hee,Um, Heung-Sik,Chang, Beom-Seok 대한치주과학회 2005 Journal of Periodontal & Implant Science Vol.35 No.4

The nature of the implant surface can directly influence cellular response, ultimately affecting the rate and quality of new bone tissue formation. The aim of this in vitro study was to investigate if human osteoblast-like cells, Saos-2, would respond differently when plated on disks of magnesium titanate and machined titanium. Magnesium titanate disks were prepared using Micro Arc Oxidation(MAO) methods. Control samples were machined commercially pure titanium disks. The cell adhesion, proliferation and differentiation were evaluated by measuring cell number, and alkaline phosphatase(ALPase) activity at 1 day and 6 day after plating on the titanium disks. Measurement of cell number and ALPase activity in Saos-2 cells at 1 day did not demonstrate any difference between machined titanium and magnesium titanate. When compared to machined titanium disks, the number of cells was reduced on the magnesium titanate disks at 6 day, while ALPase activity was more pronounced on the magnesium titanate. Enhanced differentiation of cells grown on magnesium titanate samples was indicated by decreased cell proliferation and increased ALPase activity.

한국인 하악치아의 수평적인 위치관계에 관한 연구

최승민(Seung-Min Choi),최대균(Dae-Gyun Choi),최부병(Boo-Byung Choi) 대한턱관절교합학회 2003 구강회복응용과학지 Vol.19 No.3

픽업 유틸리티 전기차용 듀얼 모터 EVT의 가속수명평가에 관한 연구

최승민(Seung Min Choi),이정일(Jeong Il Lee),김형준(Hyung Joon Kim),이수정(Su Jeong Lee),김경률(Kyung Ryool Kim),정훈(Hoon Jeong) 한국자동차공학회 2022 한국자동차공학회 학술대회 및 전시회 Vol.2022 No.11

In this study, an accelerated life test method based on the linear cumulative damage theory was designed to ensure the reliability of the dual motor EVT for a 500kg utility electric vehicle. In order to develop an accelerated life test method, major parameters were selected, and accelerated life calculation and test patterns were presented. As a result of calculation using the shape parameter values, a test with a fault-free time of 3,765 hours is required to ensure the service life of 150,000 km(equivalent to 7 years) based on 90% confidence level acceptance criteria. Considering the cumulative damage effect, the maximum design torque that can be output at each stage was used as a reference. When performed at 132 percent of the maximum design torque, the acceleration index is calculated as 23.4 and the acceleration life test time is shortened to 161 hours. For the accelerated life test, the pattern was set to perform a constant-speed durability test of 80.5 hours each reverse and forward. As a result of the test, no physical abnormality was found, and the efficiency was 96% before and after the test. Accordingly, it is judged that the reliability of the durability capability of EVT has been secured.

듀얼 모터 EVT 장착을 위한 픽업 유틸리티 내연기관 차량 개조에 관한 연구

최승민(Seung Min Choi),이정일(Jeong Il Lee),김형준(Hyung Joon Kim),이수정(Su Jeong Lee),김경률(Kyung Ryool Kim),정훈(Hoon Jeong) 한국기계가공학회 2022 한국기계가공학회 춘추계학술대회 논문집 Vol.2022 No.12

초소형 전기차용 3단 변속기 가속수명평가 방법에 관한 연구

최승민(Seung Min Choi),김진복(Jin Bok Kim),김형준(Hyung Joon Kim),이정일(Jeong Il Lee),김경률(Kyung Ryool Kim),정훈(Hoon Jeong) 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.11

In this study, the accelerated life test method was designed by extracting parameters from a transmission for a micro-electric vehicle with a motor of less than 15 Kw and calculating a shortened accelerated life test time based on the linear cumulative damage theory. Major parameters were selected to develop an accelerated life test method, and accelerated test time calculation and test pattern were presented. As a result of calculation using the shape parameter values, a test with a failure-free test time of 1,506 hours is required to guarantee a service life of 60,000 km (equivalent to 3 years) on a passing basis of 90% confidence level. Based on the maximum design torque that can be output at each stage, taking into account the cumulative damage effect. If the accelerated test is performed at 132%, the accelerated index is calculated as 23.4, reducing the time for the fault-free accelerated life test to 64.3 hours. The pattern was set so that the fatigue durability test of 64.3 hours for each stage of reversing and advancing the no-failure accelerated life test time was performed. However, since the forward first stage and the backward stage are composed of the same power transmission logic, the test time was divided. The test was designed to perform a total of 193 hours.

NetVLAD 기반의 wide-baseline 영상 탐색 기법에 관한 연구

최승민(Seung-Min Choi),이재영(Jae-Young Lee),이동환(Dong-Hwan Lee) 대한전기학회 2020 정보 및 제어 심포지엄 논문집 Vol.2020 No.10

조명에 강한 실시간 얼굴 검출 ASIC의 구현

최승민(Seung-Min Choi),장지호(Jiho Chang),황대환(Dae-Hwan Hwang),조재일(Jaeil Cho) 대한전자공학회 2010 대한전자공학회 학술대회 Vol.2010 No.6

We propose the architecture of real-time face detection hardware, and introduce its ASIC implementation. It uses MCT(Modified Census Transform) to obtain face characteristics robustly against illumination changes, and includes Pyramid Image to detect variable size of face. In addition, the AdaBoost algorithm is adopted to learn and generate the characteristics of the face data, and finally to detect the face using this data. This structure was implemented on FPGA(Xilinx Virtex5 LX330), of which maximum speed is 149 fps(frame per second) with QVGA input image. Futhermore, it was integrated a single ASIC(Application-specific integrated circuit) chip named ALTAIR that has the following features ; the size of 1.2cm x 1.2cm, the type of BGA, the speed of 30fps, the detecting accuracy for frontal face of 90%, and the power consumption of 226mW.