혈당 측정에 있어서 반사광 비색법과 전기 화학 전극법의 비교

황유성,이도훈,우재근 충북대학교 의과대학 충북대학교 의학연구소 1995 忠北醫大學術誌 Vol.5 No.1

당뇨병환자에서 적절한 혈당을 유지하기 위한 목적으로 시험지봉 검사 방법이 1970년대 초 처음으로 개발된 이후 많은 자가 혈당기들이 고안되어 사용되고 있으며, 대부분이 반사광 비색법을 이용한 자가 혈당 측정기로 현재 국내에는 Glucometer(Ames), Glucoscan(Eiken), One TouchTRM Ⅱ(Lifescan), Accu-check Ⅲ(BM)등이 사용되고 있다. 저자들은 본원에서 이미 사용하고 있었던 반사광 비색법을 이용한 시험지봉으로 LIFESCAN사의 One TouchTM Ⅱ와 전기 화학 전극법을 이용한 Medisense사의 CompanionTM 2에 대하여 정밀도, 직선성, 비교방법과의 상관관계 및 혈액량과 헤마토크리트에 의한 영향, 관찰자간의 변이, 항응고제가 미치는 영향 등 측정에 영향을 미치는 여러 인자들에 대하여 평가를 시행하였다. 검사일내 정밀성(within day precision)은 두 기기 모두 5% 정도이었고, 검사일간 정밀성(day-to-day precision)은 CompanionTM 2가 3.14%∼6.53%, One touchTM Ⅱ가 4.69%∼8.13%의 변이계수를 보였다. 두 기기 모두 직선성이나 비교방법과의 상관관계가 우수하였다. CompanionTM 2와 One touchTM Ⅱ사이의 상관관계는 y=1.040x+21.679, r=0.9716이었다. 두 기기 모두 혈액량, 관찰자, 항응고제에 의해서는 영향을 받지 않았으며, 헤마토크리트에 의해서는 헤마토크리트가 낮을 때는 높은 혈당치를, 헤마토크리트가 높을 때는 낮은 혈당치를 나타냈다. The purpose of this study is to assess two monitors of blood glucose : One touch?? Ⅱ(Lifescan Inc.), which is using reagent strips by reflectance photometry and CompanionTM 2(Medisense Inc.), which is using electrochemical electrode method. Glucose was determined on capillary and venous blood samples from 70 adult diabetics by three different methodologies : One touchTM Ⅱ, CompanionTM 2 portable glucose meters (capillary) and the Hitachi 7150 analyzer(venous), which is using hexokinase method. In within-run precision studies for One touchTM Ⅱ and CompanionTM 2, coefficient variations (CVs, %) were 1.92∼5.09, 2.95∼4.79 at three different levels, respectively. In between-day percision studies for One touchTM Ⅱ and CompanionTM 2, CVs(%) were 4.69∼8.13, 3.14∼6.53 at three different levels, respectively. The linearity studies revealed r=0.9996 in One touch?? Ⅱ, r=0.9977 in CompanionTM 2, which were satisfactory. Correlation equation and coefficient for results by One touchTM Ⅱ and CompanionTM 2 vs those by hexokinase method(x) were : y=0.8087x-8.9566(r=0.9824) for One touchTM Ⅱ, y=0.8885x+4.4992(r=0.9807) for CompanionTM 2, which were satisfactory. The glucose levels were falsely high at low hematocrit concentration and falsely low at high hematocrit concentration in both monitors. The volume of blood applied to the test strips is not critical. We concluded that "One touchTM Ⅱ" using reagent strip by reflectance photometry and "Companion?? 2" using electrochemical electrode method is suitable for self monitoring of blood glucose.

아바타 자동생성을 위한 칼라정보와 B-spline Snake을 이용한 얼굴 윤곽선검출

우재근(Jae-Kun Woo),권민수(Min-Su Kwon),이장희(Jang-hee Lee),강훈(Hoon Kang) 한국지능시스템학회 2004 한국지능시스템학회 학술발표 논문집 Vol.14 No.1

본 논문에서는 웹 카메라로 촬영된 받아진 입력영상에서 사람의 얼굴을 검출하고 검출된 얼굴을 기반으로 사람 얼굴 아바타를 생성하는 방법에 대하여 다루고 있다. 일반적으로 웹 카메라를 통해 얻은 영상은 해상도가 떨어질 뿐만 아니라 끊임없는 조명의 변화와 복장한 배경이 존재하여 얼굴을 검출함에 있어 어려움을 준다. 따라서 몇몇의 특징 점에 의존하는 방법으로 사람얼굴의 윤곽선을 찾는다는 것은 큰 어려움을 겪게 된다. 본 논문에서는 이런 방법들의 결점을 극복하기 위한 새로운 방법을 제안한다. 먼저 칼라정보를 이용하여 실험을 통하여 통계적으로 표준피부색을 정의하여 얼굴의 대략적인 위치와 크기를 얻은 다음으로 B-spline Snake를 이용하여 사람 얼굴의 윤곽선을 정확히 추출할 수 있다.

면적 연신과 전압 강하에 의한 휘도 변화를 보상하는 스트레처블 AMOLED 보상 화소 회로

이혁수,강서진,우재근,유은성,정찬민,김민성,이종모,배병성 대한전자공학회 2022 전자공학회논문지 Vol.59 No.3

스트레처블 디스플레이는 차세대 유연 디스플레이 기술로서 주목받고 있는 프리폼의 구현이 가능한 디스플레이다. 백라이트 유닛을 사용하지 않는 OLED (organic light emitting diode)와 저온 폴리 실리콘에 비해 공정온도가 낮은 a-IGZO (amorphous In-Ga-Zn Oxide) 박막트랜지스터는 스트레처블 디스플레이에 적용하기에 적합하다. 기판이 연신 되어 면적이 증가하면 평균 휘도가 감소하며 전원 라인은 전원입력 단자로부터 화소까지의 배선 거리에 따라 전원 전압 강하가 증가하여 휘도 불균일이 나타난다. 본 연구에서는 연신에 의한 평균 휘도 저하와 전압 강하에 의한 휘도 변화를 동시에 보상할 수 있는 화소 회로를 제안하였다. 제안된 화소 회로의 구동 트랜지스터의 전류는 면적이 10%와 20% 증가할 때 1.87 %와 3.74 % 증가하여 면적 연신에 의한 휘도 저하를 보상 할 수 있으며 전원전압의 2.3 V의 전압 강하에서, 일반적인 화소 회로의 전류는 25.34% 감소한 반면, 제안된 화소 회로의 전류는 9.31 % 감소하여 전원전압의 감소를 보상 할 수 있다.

Evaluation of Spray Characteristics of Pesticide Injection System in Agricultural Drones

유승화,김영근,전현종,최일수,우재근,김영화,윤영태,최용,Alidoost Reza,이지근 한국농업기계학회 2020 바이오시스템공학 Vol.45 No.4

Purpose This study aims to verify that the characteristics of the typical injection pumps and nozzles used in pesticide injection systems in current agricultural drones in Korea are consistent with those presented in the product specifications, and to provide experimental quantitative data for selecting the correct pump and nozzle. Methods The performances of three types of pumps and 18 types of nozzles currently in use were evaluated in terms of the pressure-flow rate curve, injection flow rate, spray angle, and droplet size. Results For pesticide injection pumps, the maximum pressure and pressure-flow rate curve should include the nozzle’s injection pressure and flow rate range. Most of the 18 nozzles used in the test showed nearly the same results as the flow rates suggested from the manufacturer, but the spray angle showed a difference of up to 10%. The droplet size was slightly smaller than the value suggested by the manufacturer, and the relative span factor ranged from 0.2 to 1.2. Conclusion The pressure-flow rate curves of the injection pumps and spray angles of the commercial nozzles used for agricultural control drones must be evaluated for official approval/assessment of such agricultural drones to ensure the performance of agricultural drone sprayers.

Sideways Overturning and Overturning Angle Test for a Three-Wheel Riding-Type Cultivator

강나래,최일수,이원재,우재근,김영근,최용,현창식,유수남 한국농업기계학회 2019 바이오시스템공학 Vol.44 No.1

to cultivation styles required for various field crops. Further, it is difficult to confirm the state of work using a rear-mounting-type farm implement. Therefore, it is necessary to develop a three-wheeled cultivator suitable for operation in various fields. Methods The side overturning angle is measured using only one rear wheel, which corresponds to the overturning baseline, and by matching the front wheel (center) and rear wheel to the overturning baseline (lateral). The overturning angles are measured five times in total while increasing the wheel width of the test apparatus (drive part) from 1320 to 1720 mm. For analyzing the difference load of the rear overturning angle in a three-wheel control unit, the height of the front wheel is increased by 0 to 30 cm. Results A difference of least 0.7° (1320 mm) up to 1.4° (1620 mm) between the left and right overturning angles was observed. For the sideways overturning angle (lateral) versus the sideways overturning angle (center), the left overturning angle increased by about 4%, and the right one increased by about 9%. The maximum angle at which the three-wheel riding-type cultivator implement can be operated was analyzed to be at about 44.39°. Conclusions It is safe to operate a vehicle with a sideways overturning angle less than 29° on the right and 31.4° on the left. The difference between the sideways overturning angle (center) and the sideways overturning angle (lateral) is attributed to the position of the fuel cell and the oil pump of the three-wheel riding-type cultivator. Since the minimum overturning angle on the right wheel is 29°, it is necessary to modify the structure of the cultivator

Evaluation of pepper seedling growth according to the growing period and tray for automatic transplanting

Nafiul Islam,Md Zafar Iqbal,ALI MOHAMMOD,이예슬,우재근,최일수,정선옥 충남대학교 농업과학연구소 2021 Korean Journal of Agricultural Science Vol.48 No.4

The effective growth of pepper seedlings relies on the growing period and tray used, which both aim to minimize seedling damage during the transplantation process. Therefore, the objective of this study was to evaluate the effect of red and green pepper seedling growth in plug and cylindrical paper pot (CPP) trays with different growth periods of the seedlings. Two different seedling growth trays were used for the two varieties of pepper seedlings in the same growing media. The pepper seedling growth rates were investigated at 15, 30, and 45 days for each of variety. Important parameters, e.g., the plant height, fresh weight for the plant and root, number of leaves, leaf length and width, and leaf chlorophyll contents, were measured. During the experiment, the CPP tray maintained uniform seedling growth as compared to the plug tray. CPP trays ensured the height of the seedling, with these results 0.84 to 1.6 times higher than those of the plug tray for all conditions, indicating the good quality of the pepper seedlings. The shoot and root weights were found to be greater with more leaves in the CPP tray seedlings for 45 days compared to the seedlings grown in the plug tray, whereas the green pepper variety showed a greater leaf ratio than the red pepper seedlings. The analysis of pepper seedling growth presented in this study will guide the selection of suitable growth trays and seedling periods for farmers when they undertake automatic pepper transplantation in the field.