자동초점에 사용되는 두 가지 Liquid Lens제어에 관한 연구

김남우,허창우,Kim, Nam-Woo,Hur, Chang-Wu 한국정보통신학회 2015 한국정보통신학회논문지 Vol.19 No.6

자동초점이란 영상을 획득하는 시스템에서 고정된 촬상면에 자동으로 초점이 맺히도록 렌즈를 구동시키는 방식으로 컴퓨터비전과 카메라 등에서 매우 중요하게 사용된다. 소형 카메라의 경우 자동초점에서 렌즈구동부인 actuator의 기술은 대량생산이 이용이하고, 위치센서가 불필요하며, 회로구성이 용이한 VCM방식이 널리 사용되고 있으며, 구동의 안정성에 비해 크기와 소음이 큰 스테핑모터 방식, 크기는 가장 작지만 납 함유문제 및 습도 취약성을 갖는 피에조 방식이 있다. 그 외에 액체렌즈방식이 있는데, 소형 구조에 저전력의 장점이 있지만 화질 및 신뢰성 검증 그리고 고압이 필요한 특징을 가지는 구조도 있다. 본 논문에서 5Mpixel급 이미지 센서를 통해 획득한 영상의 선예도를 이용하여 VCM의 actuator처럼 액체렌지를 제어할 수 있는 제어 시스템을 두 가지를 구현하여 자동으로 초점을 맞추는 기능을 구현 검증하였다. The autofocus system is automatically to drive the focus. It is very important to computer vision system. In the case of a compact camera, the actuator technology is used for auto-focus in mass production. the position sensor is required, the circuit configuration and easy method is widely used in VCM, compared to the stability of the drive size and the noise is a big stepping motor type, size has a piezo system having a humidity problem and the small leaded vulnerability. In addition, there is a liquid lens system, the advantages of low power in a compact structure but also a structure with proven quality and reliability and features required pressure. In this paper, we implement two control systems that can control the actuator as a liquid range of VCM using a sharpness of the image acquired by the image sensor automatically initiates 5Mpixel class was the implementation verification of focusing.

MAGIC 숫돌 구성요서의 배합율이 연마면 조도에 미치는 영향

김남우,백종흔,이상태,정윤교 한국공작기계학회 2002 한국공작기계학회 추계학술대회논문집 Vol.2002 No.-

Recently, new polishing system which was made by magnetic intelligent compound (MAGIC) was invented and, the study is going on for practical use the analysis of factors, that is, the kind of polishing grain, composition ratio of wheel elements, machining frequency, polishing pressure, which the main influence for polishing efficiency are the first step. In this study, analyzed influence of wheel raw material composition ratio on surface roughness.

대기 분위기에서 열증발법에 의해 성장된 여러 가지 형상의 일차원 MgO 나노구조

김남우,김진수,이근형 한국재료학회 2023 한국재료학회지 Vol.33 No.7

One-dimensional MgO nanostructures with various morphologies were synthesized by a thermal evaporation method. The synthesis process was carried out in air at atmospheric pressure, which made the process very simple. A mixed powder of magnesium and active carbon was used as the source powder. The morphologies of the MgO nanostructures were changed by varying the growth temperature. When the growth temperature was 700 °C, untapered nanowires with smooth surfaces were grown. As the temperature increased to 850 °C, 1,000 °C and 1,100 °C, tapered nanobelts, tapered nanowires and then knotted nanowires were sequentially observed. X-ray diffraction analysis revealed that the MgO nanostructures had a cubic crystallographic structure. Energy dispersive X-ray analysis showed that the nanostructures were composed of Mg and O elements, indicating high purity MgO nanostructures. Fourier transform infrared spectra peaks showed the characteristic absorption of MgO. No catalyst particles were observed at the tips of the one-dimensional nanostructures, which suggested that the one-dimensional nanostructures were grown in a vapor-solid growth mechanism.

이타적 충돌회피 이론 기반 무인비행 장치 충돌회피 성능 요건 분석

김남우,신유열,윤윤진 대한산업공학회 2017 대한산업공학회 춘계학술대회논문집 Vol.2017 No.4

Satisficing Theory based Cooperative Conflict Resolution Strategy for Multiple Small Unmanned Aerial Vehicles

김남우,윤윤진 한국경영과학회 2017 한국경영과학회 학술대회논문집 Vol.2017 No.10

이타적 충돌회피 이론 기반 무인비행 장치 충돌회피 성능 요건 분석

김남우,신유열,윤윤진 한국경영과학회 2017 한국경영과학회 학술대회논문집 Vol.2017 No.4

뿔가위벌류의 영소행동

전승진,김진태,김남우 慶山大學校 基礎科學硏究所 2000 基礎科學 Vol.4 No.1

We got the effective method to the nesting behavior of Osmia spp., O. cornifrons, O. pedicornis, O. satoi and O. benefica, from Korea. To get a results, we were compare to input ratio of Osmia spp. by diameter of tubes and to vertical and horizontal methods. The results are as follows; the bamboo tubes is more effective than plastic tubes in input ratio both orchard and field area. The diameter of bamboo tubes is the most effective about 7-8mm in Osmia spp. except O. pedicornis, and above 8mm and 10mm tube is uneffective in Osmia spp. and O.pedicornis respectively.

A grid-line suppression technique based on the nonsubsampled contourlet transform in digital radiography

김남우,엄태영,임현태,구본택,김규석,김규범 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.2

In radiography, an antiscatter grid is a well-known device for eliminating unexpected x-ray scatter. We investigate a new stationary grid artifact suppression method based on a nonsubsampled contourlet transform (NSCT) incorporated with Gaussian band-pass filtering. The proposed method has an advantage that extracts the Moire components while minimizing the loss of image information and apply the prior information of Moire component positions in multi-decomposition sub-band images. We implemented the proposed algorithm and performed a simulation and an experiment to demonstrate its viability. We did this experiment using an x-ray tube (M-113T, Varian, focal spot size: 0.1 mm), a flatpanel detector (ROSE-M Sensor, Aspenstate, pixel dimension: 3032 3800 pixels, pixel size: 0.076 mm), and carbon graphite-interspaced grids (JPI Healthcare, 18 cm 24 cm, line density: 103 LP/ inch and 150 LP/inch, ratio: 5:1, focal distance: 65 cm). Our results indicate that the proposed method successfully suppressed grid artifacts by reducing them without either reducing the spatial resolution or causing negative side effects. Consequently, we anticipate that the proposed method can improve image acquisition in a stationary grid x-ray system as well as in extended x-ray imaging.

韓國 초파리 集團의 遺傳的 變異에 對한 分析 : 致死遺傳子, 不姙遺傳子 Lethal Gene, Sterility Gene

李澤俊,金南佑 중앙대학교 기술과학연구소 1986 기술과학연구소 논문집 Vol.16 No.-

본 실험은 자연집단에서 채집한 노랑 초파리의 제2염색체에 보유되어 있는 열성 치사유전자 및 불임유전자 빈도를 분석하여 집단의 유전적 구조를 밝히고자 수행하였다. 1. 치사유전자 빈도는 Anyang집단에서 '84년과 '85년에 11.11%, 21.77%였으며, Kimpo집단에서는 '84년에 13.11%, '85년에 21.66%였고 Deajeon과 Jeonju집단은 20.00%와 25.19%로 분석되었다. 2. 자연집단에서 검출된 치사유전자 사이의 동좌율을 조사하였으며 유해유전자와 동좌율로 인하여 자연집단에서 제거되는 제거율을 산정하였다. Anyang집단의 동좌율은 '84년과 '85년에 각각 2.86%와 2.28%였으며, 제거율은 0.0032와 0.0029였다. Kimpo집단의 '84년과 '85년의 동좌율은 2.50%와 1.96%였으며 제거율은 0.0015와 0.0025였다. Daejeon '85 집단의 동좌율은 1.54%, 제거율은 0.0011이었고, Jeonju '85집단의 동좌율은 1.78%, 제거율은 0.0023이었다. 3. Nei 공식을 이용하여 유효 생식집단 크기를 산정한 결과 '84년과 '85년의 Anyang과 Kimpo 집단의 평균 유효 생식집단 크기는 각각 2246과 3072였으며 Daejeon과 Jeonju 집단에서는 각각 4748과 4327로 나타났다. 이러한 결과로 보아 한국 노랑 초파리 자연집단은 약 2500에서 4500의 범위에 들어가는 중집단으로 추정할 수 있다. 4. 집단간 동좌율을 구한 결과 집단간 동좌율은 집단간 거리가 멀수록 감소하는 경향을 나타냈다. Anyang-Kimpo (35 km) 집단간의 평균동좌율은 1.29%였으며 Daejeon-Keonju(60 km)는 1.02%, Anyang-Daejeon (120 km)은 0.84%, Kimpo-Daejeon(169 km)는 0.90%, Anyang-Jeonju (165 km) 집단간은 0.92%였고 Kimpo-Jeonju(200 km)의 동좌율은 0.69%였다. 5. 제2염색체상의 열성 불임유전자 빈도는 집단간 큰 차이가 없었다. 수컷과 암컷의 평균불임유전자 빈도는 각각 5.50%와 3.31%였고, 양성불임은 0.48%로 매우 낮았다. Analysis of genetic structure in Korean natural populations was made in the present experiments by utilizing the recessive lethals and sterility genes on the second chromosome of Drosophila melanogaster. Fruit flies tested were collected from four different localities ; in September of 1984 and 1985 at Anyang and Kimpo, September 1985 at Daejeon and Jeonju, respectively. The results obtained were as follows. 1. The lethal gene frequencies were estimated to be 11.11% in the '84 and 21.77% in the '85 of Anyang, 13.11% in the '84 and 21.66% in the '85 of Kimpo, 20.00% in the Daejeon, and 25.19% in the Jeonju population, respectively. 2. Allelism of lethal genes and elimination rate (IQ²) of lethals in homozygous condition were obtained ; Allelic rates were estimated to be 2.86% and 2.28% in the two of Anyang, 2.50% and 1.96% in the two of Kimpo, 1.54% in the Daejeon and 1.78% in the Jeonju population, respectively ; Elimination rates were estimated to be 0.0032 and 0.0029 in the two of Anyang, 0.0015 and 0.0025 in the two of Kimpo, 0.0011 in the Daejeon and 0.0023 in the Jeonju population, respectively. 3. The effective population size was estimated by using the Nei's formula. The means of Anyang and Kimpo populations were estimated to be 2300 and 3072, respectively. The effective size of Daejeon and Jeonju were 4748 and 4327, respectively. The present data suggests that Korean populations of Drosophila melanogaster attained to relatively stable breeding units of intermediate size, ranging from about 2500 to 4500 pairs of fertile individuals. 4. The allelic rates of interpopulation showed a tendency in relation with geographical distance ; those of near populations appeared to be rather higher rate than those of far more apart ones. The allelic rates of Anyang-Kimpo (35 Km) was 1.29%, and those of Daejeon-Jeonju (60 Km), Anyang-Daejeon (120 Km), Kimpo-Daejeon (160 Km), Anyang-Jeonju (165 Km), Kimpo-Jeonju (200 Km) were 1.02%, 0.84%, 0.90%, 0.92%, and 0.69%, respectively. 5. The frequencies of sterility genes on the second chromosomes were not different significantly among populations. The mean frequencies of male and female sterility genes were 5.50% and 3.31%, respectively. On the other hand, the mean frequency of both sexes was 0.48%.

사과원에서 머리뿔가위벌의 영소활동에 관한 연구

전승진,김진태,김남우 慶山大學校 基礎科學硏究所 1999 基礎科學 Vol.3 No.2

This study on nesting behavior of Osmia cornifrons as insect pollinators utilized to improve fruit fertilization and high quality production of apples. Plug ratio of O. cornifrons showed rapid increase, 25.4%, 26.2%, 27.4% and 27.7%, by 25 days and average plug ratio is 26.9%. And plastic tube is showed more rapid increase, 47.8%, 67.2%, 46.9% and 51.4%, than bamboo about 31 days after release of O. cornifrons. Average plug ratio is 53.3% in this times. So plastic tube showed more increase than bamboo in early time after release. But bamboo tubes are more effective than plastic for artificial of O. cornifrons in orchards.