나노부품 초정밀가공기용 마이크로스테이지의 절삭력 예측모델 시뮬레이션

김재열,심재기,곽이구,안재신,한재호,노기웅 한국공작기계학회 2003 한국공작기계학회 춘계학술대회논문집 Vol.2003 No.-

Recently, according to the development of mechatronics industry that was composed of NT, ST, IT, RT and etc, the necessity of nano-parts was increased. Because of the necessity, this research was started for improving work precision of the parts as fixing UPCU (Ultra Precision Cutting Unit) on lathe. So, in this research, we executed the modeling of UPCU (Ultra Precision Cutting Unit) by the application of PZT, the relationship between the displacement of tool in UPCU and the cutting force of it has been in take a triangular position in the case of plane cutting. The modeling of system, that is containing the fine displacement, was performed. Also, we would like to find the optimal cutting condition through the simulation of relationship between the displacement and the cutting force.

손가락 끝 점을 이용한 손 형상 인식

김종민,이웅기,장근실,양환석,허진경,박승규 朝鮮大學校 統計硏究所 2007 統計硏究所論文誌 Vol.9 No.1

최근 사용자 친화형 유저 인터페이스 구현을 위해 인간의 손 형상을 실시간으로 인식하는 연구의 중요성이 부각되고 있다. 그러나 인간의 손은 자유도가 크기 때문에 손 형상을 정확히 인식하기란 매우 어렵고 또한 피부색과 유사한 색을 가지는 복잡한 배경에서는 더욱 곤란하다. 본 논문에서는 별도의 센서를 부착하지 않고 카메라를 사용하여 피부색 정보에 의한 손 형상을 분할한 후 손가락 끝 점을 찾는다. 찾은 손가락 끝 점을 이용하여 방향을 탐지하는 알고리즘에 대해 기술한다. 이 방법은 템플리트 매칭을 이용하여 손가락 끝 점을 탐색한 후 찾은 손가락 끝 점과 손목의 중심을 이용하여 전, 후, 좌, 우 방향을 탐지한다. 제안하는 방법을 이용하여 3D 가상현실 공간에서의 네비게이션(Navigation)에 응용하였으며, 실험결과 전진, 후진 및 좌측, 우측의 방향전환도 매우 좋은 결과를 보였다. 또한 본 논문에서 제안하는 방법은 마우스, 키보드, 조이스틱 등의 조작 없이 전, 후, 좌, 우 방향전환을 사용자가 직관적으로 지시함으로써 보다 자연스러운 인간과 컴퓨터의 상호작용을 제공할 수 있을 것이다.

정지영상 압축을 위한 이진적응에 관한 연구

김향태,위승정,정재영,최호진,최봉한,이웅기 조선대학교 통계연구소 1999 統計硏究所論文誌 Vol.1 No.1

대용량 저장장치의 출현, 컴퓨터 성능 및 초고속 망의 급속한 성장, 디지털 필름스캐너의 성능 향상 및 비용 감소 덕분에 디지털 형태로 영상을 다루기 위한 요구가 점차 증대되는 추세이다. 디지털 영상은 항상 고품질을 유지해야 하므로 화소 당 비트를 높게 할당하는데 이때 소요되는 방대한 비트 수를 효과적으로 감소시켜 저장용량 및 대역폭을 줄이기 위해서는 효율적인 영상 압축이 요구된다. 본 눈문은 디지털 영상의 압축을 위한 새로운 이진적응 방식을 제안한다. 먼저 변환된 예측오류를 얻기 위해 적응예측을 하고, 모델 템플리트로부터 적당한 예측오류 값 영역을 하나의 context영역이 되도록 하는 방식으로 부호화에 적절한 수의 context 영역을 결정한다. 그리고 부호화 효율을 개선하기 위해 개별적인 context 영역에서 부호화 될 예측오류가 나타날 확률을 근접하게 추정한 후, 고 빈도 예측 심볼 집합을 이진적응에 적용하여 부호화의 효율을 개선한다.

여중생들의 신체조성과 심폐기능 및 심박수 회복율에 관한 비교 연구 : 비만 여중생과 정상 여중생을 중심으로

김태운,신군수,김종인,이광무,김성헌,안병철,고기준,한재웅,이재규 釜山大學校 附設 體育科學硏究所 1996 體育科學硏究所 論文集 Vol.12 No.-

The purpose of this study was to compare and analyze the relation between body composition, cardiorespiratory functions and percent heart rate recovery in obese and normal middle school female students. We used total of 12 middle school female students(3rd grade) as subject and devided them into two groups : The measurement items of cardiorespiratory functions were HR, VE, RQ, VO₂, VCO₂, VO₂/kg, O₂pulse, VE/VO₂, VE/VCO₂, before and after treadmill exercise load. The statistical analysis were M±SD and t-test for groups(α=.05) using ?? statistical package. The conclusion of this study was as follows ; 1. In 5 items(FM, LBM, %Fat, TBW, BMI) all of body composition, obese group has been significantly higher than normal group(P<0.01). 2. In heart rate and VO₂ of resting(before exercise loads) cardiorespiratory functions, normal group has been significantly higher than obese group(P<0.05). 3. In VEmax of cardiorespiratory functions after exercise loads, obese group has been significantly higher than normal group(P<0.05), and in VO₂max, obese group has been significantly higher than normal group(P<0.01). 4. In 1, 3, 5 minute percent recovery all of percent heart rate recovery after exercise loads, normal group has been higher than obese group but there was no statistical significant difference.

규칙적인 유산소성 운동이 비만아동들의 신체구성 및 호흡순환기능에 미치는 영향

김태운,신군수,김종인,이광무,김성헌,안병철,고기준,한재웅,이재규 釜山大學校 附設 體育科學硏究所 1997 體育科學硏究所 論文集 Vol.13 No.-

The purpose of this study was to examined the effect of supervised regulary aerobic exercise program with cardiorespiratory function of obese children. The subjects were 16 obese Childrens(elementary school 4∼5 grade), and engaged in regulary aerobic exercise program for 9 weeks(5 days/week, 100 min/day, 60∼70% HRmax) with mountain climbing, basketball and football. The items of cardiorespiratory function measured VEmax, HRmax, RQmax, VCO₂max, VCO₂max, VCO₂max/kg and BFmax after treadmill exercise load. The conclusion of this study was as follows ; 1. In body composition, there were significant decrease(P<0.001) after aerobic exercise for 9 weeks in body weight, percent body mass index 2. In cardiorespiratory function, there were significant increase(P<0.001) after aerobic exercise for 9 weeks in VEmax and VCO₂max by treadmill exercise load. 3. In cardiorespiratory function, there were significant increase(P<0.001) after aerobic exercise for 9 weeks in VO₂mex and RQmax by treadmill exercise load. 4. In cardiorespiratory function, there were significant increase(P<0.001, P< 0.01) after aerobic exercise for 9 weeks in VO₂max/kg and BFmax by treadmill exercise load.

취학전 아동들의 체격 및 기초체력에 관한 비교 연구

김태운,안병철,고기준,한재웅,이재규 釜山大學校 附設 體育科學硏究所 1997 體育科學硏究所 論文集 Vol.13 No.-

The purpose of the present investigation was to compare and analyze the physique and physical fitness for children(boys:876, girls:784, age: 7 yrs), and to correlation between physique and physical fitness 5 items. The measurement items of physique and physical fitness were height, weight and sitting trunk flexion, 50M run, standing long jump, foot balance, flexed arm hang test. The statistical analysis were calculated to mean and standard deviation for all measurement values and correlation coefficients between physique and physical fitness 5 items for children using SPSS/PC+ statistical package(α=.05). The conclusion of the present investigation was as follows; 1. Physique 1) In height, boys(118.31 ±23.92cm) has been significantly higher than girls(116.11 ±4.72cm)(P<0.05). 2) In weight, boys(22.31 ±3.54kg) has been significantly higher than girls(21.17 ±3.31kg)(P<0.01). 2. Physical fitness 1) In sitting trunk flexion, girls(11.67 ±4.37cm) has been significantly higher than boys(9.97 ±4.48cm)(P<0.01). 2) In 50M run, boys(12.58 ±1.30sec) has been significantly faster than girls(13.30 ±1.59sec)(P<0.01). 3) In standing long jump, boys(112.99 ±16.36cm) has been significantly higher than girls(98.94 ±16.24cm)(P<0.01). 4) In foot balance, girls(30.90 ±19.66sec) has been significantly higher than boys(26.65 ±19.25sec)(P<0.01). 5) In flexed arm hang, boys(8.68 ±7.94sec) and girls(8.58 ±8.11sec) had no significant difference. 3. Correlation between physique and physique and physical fitness 1) In correlation between height and physical fitness, boys were no little correlation in 5 items all, and girls and total were significantly low correlation(P<0.01) between height and 50M run, standing long jump. 2) In correlation between weight and physical fitness, boys and girls all were significantly low correlation between weight and standing long jump(P<0.05), flexed arm hang(P<0.01), and total were significantly low correlation between weight and 50M run(P<0.05), standing long jump(P<0.01), flexed arm hang(P<0.01).

우리나라 湖水의 Chlorophyll-a 濃度와 無機營養鹽類 사이의 相關性 分析

金東植,方起雄 大田工業大學 1992 한밭대학교 논문집 Vol.9 No.2

ABSTRACT Summer mean data derived from various survey reports on Korean lakes since 1980 were used in order to relate chlorophyll-a concentration to inorganic nutrients and to find limiting nutrients to phytoplankton growth. From the analysis of data, POY4-P is an important limiting nutrient in Korean lakes. When the ratio of Inorganic-Nitrogen/POY4-P was greater than 17 and POY4-P concen- tration was less than 60mg/m3, the limiting nutrient was POY4-P, especially. A simple regression of chlorophyll-a concentration to inorganic nutrients showed that the models were log(Ch. -a)=0.563 log (POY4-P) -0.024 and log(Chl.-a)=1.377 log(Inorgan.-N)-3.225. Correlation coefncients of models in Korean lakes were Iower than those in foreign natural lakes. These reasons might be related to Iow transparency caused by SS from inflowing stream and short hydraulic retention time in Korean lakes. Summer mean data derived from various survey reports on Korean lakes since 1980 were used in order to relate chlorophyll-a concentration to inorganic nutrients and to find limiting nutrients to phytoplankton growth. From the analysis of data. PO_4 -P is an important limiting nutrient in Korean lakes. When the ratio of Inorganic-Nitrogen/PO_4-P was greater than 17 and PO_4-P concen-tration was less than 60mg /m^3, the limiting nutrient was PO_4- P, especially. A simple regression of chlorophyll -a concentration to inorganic nutrients showed that the models were log(Ch. -a)=0.563 lo9(PO_4-P)-0.024 and log(Chl.-a)=1.377 log(Inorgan.- N) -3.225. Correlation coefficients of models in Korean lakes were lower than those in foreign natural lakes. These reasons might be related to low transparency caused by SS from inflowing stream and short hydraulic retention time in Korean lakes.

다층 BTC에 대한 유전자 알고리즘 설계

김향태,이웅기 조선대학교 통계연구소 2000 統計硏究所論文誌 Vol.2 No.1

본 논문에서는 다층 BTC부호화의 설계에 대한 새로운 스키마를 제안한다. 최적의 양자화는 상세한 탐색으로 양자화 초기 값을 선택함으로써 얻을 수 있다. 그러나, 이것은 거대한 양의 계산결과를 요구하고, 또한 다층 BTC에 대한 상세한 탐색을 고려했을 때 비현실적이다. 원래의 이미지와 재구성된 이미지 사이의 AMSE(average mean square error)가 최소이기 위한 더 좋은 초기값을 유지하기 위해서 유전자 알고리즘을 적용한다. 상세한 탐색으로 제안된 방법의 결과치를 비교하면 전자의 방법이 대부분 후자의 경우에서 요구된 것보다 훨씬 적은 계산량으로 적절한 양자화를 달성할 수 있다.

합성피혁제조업체 근로자들에 있어서 N-methylformamide 배설속도에 관한 연구

김기웅,최병순,강성규,문영한 大韓産業醫學會 1999 대한직업환경의학회지 Vol.11 No.1

This study was conducted to examine the excretion rate of dimethylformamide(DMF) from the workers exposed to DMF. The study was done at two synthetic leather factories located in Kyeonggi-do from the period of May 2 to 30, 1996. N-methyl-formamide (NMF) concentrations in urine were measured and compared by the three exposure level of DMF in air. The mean concentration of the Low (dry and winder part), Moderate (rinsing part) and High (mixing and coating part) exposure group were 3.99±3.54, 10.19±5.69 and 32.10±7.87㎎/㎥ during workshift of 8 hours, respectively. The mean concentration of urinary N-methylformamide (NMF) were 2.13±2.58, 11.16±4.98 and 26.24±7.35㎎/g creatinine, respectively. The concentration of NMF in urine could reach to maximum in 3 hours and was reduced nearly to zero in about 18 hours after exposure to DMF.

산란 초음파의 주파수 특성을 이용한 단일 섬유 복합재료의 인터페이즈 평가법 개발

김웅기,임현준 韓國非破壞檢査學會 1999 한국비파괴검사학회지 Vol.19 No.2

본 연구에서는 산란 초음파의 주파수 특성을 이용하여 단일 섬유 복합재료내 인터페이즈의 물리적 성질을 측정하는 방법을 제안하고, 그 가능성을 이론적으로 고찰하였다. 그 결과, 주파수 영역에서 나타나는 산과 골의 위치 및 크기가 인터페이즈의 성질에 의해 상당한 영향을 받음을 보임으로써 이 방법의 타당성을 확인하였다. 산란 초음파의 주파수 거동은 산란체의 공명과 관련되어 있지만, 공명 피크가 음향파의 경우만큼 두드러지지 않아 기존의 음향 공명산란이론을 바로 적용할 수 없었다. 산란 초음파의 주파수 특성으로부터 인터페이즈의 성질을 구하는 역문제의 해법으로서 신경회로망을 구성하였으며, 이를 사용하면 대부분의 경우 인테페이즈의 성질을 상당히 정확하게 추정할 수 있었다. A method is proposed to characterize single-fiber composite interphases from the frequency-domain characteristics of scattered ultrasonic waves, and its feasibility is investigated theoretically. It has been shown that the locations and magnitudes of the peaks and valleys in the frequency domain are affected significantly by the interphase properties, which may indicate the effectiveness of the proposed method. Although the frequency-domain behavior is basically associated with the resonance of the fiber-inter phase system, it is not dominantly affected by the scatterer's resonance unlike that in the case of acoustic wave scattering. Therefore, the conventional acoustic resonant scattering theory is not directly applicable to the characterization of composite interphases. In order to solve the inverse problem of predicting the interphase properties from the frequency-domain characteristics of the ultrasonic scattered waves, an artificial neural network has been constructed. This approach has demonstrated reasonable accuracy in most cases considered in this study.