• 전자공학회논문지SC
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• 제40권3호
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• pp.135-144
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• 2003

본 논문에서는 고속 혼성모드 집적회로를 위한 온-칩(on-chip) CMOS 전류 및 전압 레퍼런스 회로를 제안한다. 제안하는 전류 레퍼런스 회로는 기존의 전류 레퍼런스 회로에서 부정확한 전류 값을 조정하기 위해 주로 사용되는 아날로그 보정 기법과는 달리 디지털 영역에서의 보정 기법을 사용한다. 또한, 제안하는 전압 레퍼런스 회로는 고속으로 동작하는 혼성모드 집적회로의 출력단에서 발생할 수 있는 고주파수의 잡음 성분을 최소한으로 줄이기 위해 고주파 신호 성분에 대해 작은 출력 저항을 볼 수 있는 구조의 레퍼런스 전압 구동회로를 사용한다. 이 레퍼런스 전압 구동회로는 전력 소모 및 칩 면적을 최소화하기 위해서 저 전력의 증폭기와 크기가 작은 온-칩 캐패시터를 사용하여 구현하였다. 제안하는 레퍼런스 회로는 0.18 um n-well CMOS 공정으로 설계 및 제작되었으며, 250 um x 200 um의 면적을 차지한다. 칩 제작 및 측정결과, 제안하는 전류 및 전압 레퍼런스 회로는 공급 전압 및 온도의 변화에 대해서 각각 2.59 %/V와 48 ppm/℃의 변화율을 보인다.

• The Korean Journal of Ecology
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• 제24권2호
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• pp.111-115
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• 2001

Vegetational changes along elevational and topographical gradients were studied in Mt. Jumbong which is located at the core area of the Mt. Sorak Biosphere Reserve in Kangwon-do Province in central Korea. Two 500 m north-south transects crossing two valleys and a small ridge were laid out, and fifty-one 10 m$\times$10 m permanent quadrats were systematically set up. All trees bigger than 2.5 cm DBH were marked with numbered aluminum tags, and their DBH measured and the species identified. Coverage of plant species in the herb layer were determined in two 2 m $\times$ 2 m subquadrats in each of the permanent quadrats. Thirty-two species of woody plants occurred in the tree layer in the permanent quadrats studied. Quercus mongolica was the dominant species across the study site, and Acer pseudosieboldianum and Carpinus cordata were also important. Quercus mongolica occurred on the ridges and south-facing slopes, and Acer pseudosieboldianum occurred extensively except for valleys. In contrast, Fraxinus mandshurica, Acer mono, Acer triflorum, and Ulmus laciniata were common in valleys. At the herbaceous layer, 112 species were identified. Dominant species were Ainsliaea acerifolia and Sasa borealis on the ridges, Meehania urticifolia on north-facing slopes, and Deutzia glabrata on valleys. Soil environmental factors were compared among the quadrats. pH was lower in the quadrats located on ridges and south-facing slopes, and organic matter was lowest on south-facing slopes. Quadrats located on valleys were generally higher in pH, organic matter, N, P, K, Ca and Mg. DCA ordinations for tree layer and herb layer were carried out in order to identify the dominant environmental factors affecting the distribution of plant species along the environmental gradients. Correlation analysis between ordination axis scores and environmental factors showed that axis one was negatively correlated with elevation and positively correlated with soil organic matter, pH, Ca, Mg, and P, but that axis two was positively correlated with elevation. These results indicate that vegetation responds very sensitively to elevational and topographical gradients although the study area is relatively small with about 100 m in elevational variation.

• 상하수도학회지
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• 제19권6호
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• pp.749-757
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• 2005

The present study analyzed actual cases of designed flow estimation method and designed flow rate of sewage pipe lines. In order to examine the effects of peak-hour demand factor estimation with given daily highest peak loading, we analyzed its effects on designed flow rate with changing the peak-hour demand factor from 2.0 to 10.0. The results of this study are as follows. When reviewing the recent designs, we found that 59.4% of pipe line with 250mm and 300mm diameter, which fall under minimum allowable pipeline did not meet the minimum velocity which is specified as 0.6m/sec in design standards. The pipe line that have minimal access population or have very low slope did not satisfy the minimum velocity. In estimating the designed sewage flow, the applied daily highest peak loading and hourly highest peaking loading were the load factor for the entire population of the planned area, and for the peak loading of the initial pipes connected to a very small population, we applied the same factor as that applied to the entire area and, as a result, the hourly highest flow was underestimated. Because, in case of the initial pipes, the method of applying the same peak loading to all subject areas is highly possible to produce underestimated design flow, when estimating the designed flow of the initial pipes connected to a small population need to adopt a rational flow factor according to the size of population. For this, it is considered to investigate and analyze raw data on daily and hourly variation of sewage flow.

• 디지털융복합연구
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• 제10권7호
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• pp.193-200
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• 2012

본 연구는 2008년 환자조사 자료를 이용하여 위장질환과 충수염질환을 대상으로 지역간 입원의료이용의 변이정도와 양상을 파악하고, 변이 발생에 영향을 미치는 관련 요인을 분석한 후, 이를 기초로 변이를 최소화하여 의료 이용을 적정화 시킬 수 있는 방안을 모색하기 위해 수행하였다. Extremal Quotient(EQ)와 변이계수(CV) 지표를 사용하여 변이수준을 파악하였고, 다중회귀분석을 통해 입원의료이용의 차이에 영향을 미치는 주요 요인들을 분석하였다. 주요 연구결과는 다음과 같다. 첫째, 위장질환의 소규모 지역별 성 연령 표준화에 따른 입원율의 경우 EQ 15.1, CV 0.4의 변이를 보였으며, 특히 농어촌 지역에서 변이 10대 상위군이 높은 분포를 나타냈다. 또한, 인구만명당 병상수, 의사수, 특수의료장비수에 따라 입원의료이용량이 통계적으로 유의한 양의 관계를 보였다. 둘째, 충수염질환에서는 EQ 12.41, CV 0.4를 나타냈고, 회귀분석을 통해 입원의료이용의 차이에 영향을 미치는 요인을 분석한 결과 통계적으로 유의하지 않았다. 본 연구 결과의 정책적인 함의로는 급성질환자의 입원의료이용의 형평성을 제고할 수 있도록 지역별 병상의 적정한 공급 관리와 효율적인 자원배분 및 의료서비스의 질적 차이를 감소시킬 수 있는 다각적인 정책 방안이 추진되어야 함을 시사해 준다.

• 대한원격탐사학회지
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• 제27권4호
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• pp.403-410
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• 2011

연안 환경에 대한 효과적인 관측을 위해서는 높은 주기 및 공간 해상도의 지속적인 관측이 필요하다. 지상에 설치한 기기로부터 이루어지는 원격 관측은 소수의 현장 기기 개수로는 관측할 수 없는 넓은 범위의 해역을 통시에 관측할 수 있고 또한 높은 빈도의 지속적인 관측이 가능하다. 본 연구에서는 연안 환경에 대한 대표적인 지상 원격 관측 기기인 마린 레이다와 카메라 시스템의 활용에 대하여 고찰해본다. 마린 레이다는 시간적으로 연속된 레이다 영상으로부터 파수 스펙트럼을 계산하고 이를 통합 적분하고 조정 전달함수를 적용하여 시간에 따른 주파수 스펙트럼을 산출할 수 있다. 또한 시간에 따른 파랑 레이다 영상을 평균함으로서 쇄파대와 이안류 그리고 연안사주의 위치 등에 대한 분석도 기능하다. 카메라 시스템은 해안선의 변화뿐만 아니라 오염 등으로 인하여 해안에서 발생하는 거품 발생량의 변화에 대한 분석을 할 수 있다. 빗각 촬영된 거품 영상을 기하 보정 후 거품부분을 따로 추출함으로서 거품량에 대한 정량적인 분석이 가능하다. 위의 두 기기는 각기 그 특성이 다른 센서로서 이를 동시에 활용하면 연안환경 관측에 있어 시너지 효과를 얻을 수 있다.

• Plant Resources
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• 제6권3호
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• pp.159-164
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• 2003

This study was conducted to investigate the relationship between yearly variations of climatic elements and yearly variations of productivity in malting barley. In addition, correlation coefficients among yield and yield components were estimated. The data of yield and yield components were investigated for 10 years from 1991 to 2000. The meteorological data gathered at the Yeosu Weather Station for the same period were used to find out the relationships between climatic elements and productivity. Yearly varation of the amount of precipitation in December and January were large with coefficients of variation(c. v.) of 97.9, 51.3%, respectively, but the variation of the maximum temperature and minimum temperature in April were relative small. Yield, weight of 1,000 grains and culm length were greatly with c. v. of 37.3, 49.3 and 41.3%, respectively. spike length and number of spikes show more or less c. v. of 3.8, 24.7% respectively and number of grains per spike show still less variation with c. v. of 9.4%. Correlation coefficients between temperature of mean, maximum and minimum in February and seed yield and yield components were positively significant at level of 5.1%, respectively. Correlation coefficients between precipitation of April and seed yield were positively significant correlation at the level of 5.1 %, respectively, but the duration of sunshine in April and seed yield were negatively significant at the level of 5.1%, respectively. Correlation coefficients of those, yield components and yield, culm length, spike length, number of grains per spike, number of spikes per $m^2$, weight of 1,000 grains and seed yield were positively significant at the level of 5.1 % respectively.

• 한국어류학회지
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• 제28권4호
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• pp.249-259
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• 2016

경남 남해 앵강만 잘피밭에서 2013년 10월부터 2014년 9월까지 소형 지인망을 이용하여 월별 어류군집의 특징 및 종조성을 조사하였다. 조사 기간 동안 총 6목 22과 35종 3,174개체, 3,137 g이 채집되었다. 우점종은 살망둑이었으며, 다음으로 베도라치, 그물코쥐치, 날개망둑, 미역치 순으로 채집되었다. 앵강만 잘피밭을 이용하는 어류들은 시기를 달리하여 출현하였으며, 채집된 대부분의 어류는 크기가 작은 유어였다. 우점종의 출현 양상을 고려할 때 유어는 수심이 얕은 잘피밭을 성육장으로 이용하고 성장함에 따라 보다 깊은 수심의 잘피밭으로 서식지를 이동하는 것으로 생각된다. 앵강만 잘피밭에서는 남해안 잘피밭에서 수행된 선행연구들에서는 보고되지 않은 날 매퉁이, 쑤기미, 꼬치고기 그리고 흰점꺼끌복이 채집되었다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.218-225
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• 2008

When the heat release and acoustic pressure fluctuations are generated in the combustor by irregular combustion, these fluctuations affect the mass flow rate of the propellants injected through the injectors. Also, the variations of the mass flow rate by these fluctuations again bring about irregular combustion and furthermore that is related with combustion instability. Therefore, it is very important to identify the mass variation for the pressure fluctuation on the injector and to investigate its transfer function. So, we first have studied quantifying the variation of mass flow rate generated in simplex swirl injector by injection pressure fluctuation. To acquire the transient mass flow rate in orifice with time, we have tried to measure of the flow axial velocity and liquid film thickness in orifice. The axial velocity is acquired through theoretical approach after measuring the pressure in orifice and the flow area in the orifice is measured by electric conductance method. As results, mass flow rate calculated by axial velocity and liquid film thickness measuring in orifice accorded with mass flow rate acquired by direct measuring method in the small error range within 1 percents in steady state and within 6 percents as average mass flow rate in pulsated state. Hence this method can be used to measure the mass flow rate not only in steady state but also in unsteady state because the mass flow rate in the orifice can acquire with time and this method shows very high accuracy based on the experimental results.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.783-788
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• 2003

In this paper, we present a new approach to detect and recognize human face in the image from vision camera equipped on the mobile robot platform. Due to the mobility of camera platform, obtained facial image is small and pose-various. For this condition, new algorithm should cope with these constraints and can detect and recognize face in nearly real time. In detection step, ‘coarse to fine’ detection strategy is used. Firstly, region boundary including face is roughly located by dual ellipse templates of facial color and on this region, the locations of three main facial features- two eyes and mouth-are estimated. For this, simplified facial feature maps using characteristic chrominance are made out and candidate pixels are segmented as eye or mouth pixels group. These candidate facial features are verified whether the length and orientation of feature pairs are suitable for face geometry. In recognition step, pseudo-convex hull area of gray face image is defined which area includes feature triangle connecting two eyes and mouth. And random lattice line set are composed and laid on this convex hull area, and then 2D appearance of this area is represented. From these procedures, facial information of detected face is obtained and face DB images are similarly processed for each person class. Based on facial information of these areas, distance measure of match of lattice lines is calculated and face image is recognized using this measure as a classifier. This proposed detection and recognition algorithms overcome the constraints of previous approach [15], make real-time face detection and recognition possible, and guarantee the correct recognition irregardless of some pose variation of face. The usefulness at mobile robot application is demonstrated.

• Journal of Preventive Medicine and Public Health
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• 제11권1호
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• pp.41-48
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• 1978

To examine the result of the government Medical Aid Program which began in January, 1977 as a part of social security policy implementation, all the medical records of the clients and official statistics in the year were analysed. The specific objectives this study pursues include the magnitudes and patterns of morbidity and utilization, and the characteristics of clients. One Korean rural area, Koje county was selected as the study area and subsequently all the clinics and hospitals assigned to work out the Aid Program are the subjects for the survey. A brief summary of the sutdy results as follows: a. The clients of Koje county are 6.4% of the total population in the area, more than the average percentage of the clients in Korea. It reflects on low level of economic status of the residents of the area. b. The population structure of the clients indicates that the large proportions of young and old age group are overwhelming, while the middle age group share very small portions. c. The utilization rates for primary care are 2.0 persons, 11.6 visits and 22.6 treatment days per 100 persons per months. Annual hospitalization is rated as 13.7 cases and 164 days per 1,000 persons, The utilization rates are slightly lower than those expected rates during planning period but eventually become higher than those of general population in rural Korea. d. The factors which influence the utilization rates are identified with client group (low income vs indigent), age and sex. e. The utilization pattern for primary care demonstrates seasonal variation similar to the pattern of general rural population in the low income group, but none in the indigent group. f. The most common diseases revealed at the primary care clinics are the acute respiratory infection (26.9%), acute gastritis (10.8%), skin and subcutaneous infection (6.8%). The cases of acute conditions are outnumbered than the cases of chronic condition. 8. The clinics, hospitals and other related health institutions are well cooperated in dealing health care services in their own capacities. Considering the above results Medical Aid Program generated satisfactory results at least in the utilization aspect.