• 지구물리
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• 제9권4호
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• pp.371-376
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• 2006

고해상도의 디지털 카메라는 근거리 수치사진측량에서 널리 유용하게 사용되고 있으며 점차 활용도가 증가하고 있다. 또한 사진측량 장비의 급속한 발전으로 정밀도가 많이 향상되었고 컴퓨터를 이용한 지형공간정보체계기술의 발달로 더욱 정밀한 3차원 지형의 재현과 면적 및 토공량 산정이 가능하게 되었다. 본 연구에서는 휴대가 간편하고 수치영상의 자체저장능력을 지닌 디지털 카메라를 이용하여 촬영조건의 다양한 변화에 따른 위치오차를 분석하였으며 광속조정을 통하여 높은 정확도의 화소 좌표를 획득하여 3차원 지형의 모델링을 위한 기초 자료로 사용할 수 있도록 하였다.

• 한국측량학회지
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• 제21권2호
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• pp.147-154
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• 2003

근거리 수치사진측량은 카메라의 취급이 비교적 간단하고 카메라의 노출점을 임의로 결정하여 카메라와 대상물의 관계를 자유로이 조정할 수 있으므로 소규모지역 또는 지상의 대상물을 측정하는데 효과적으로 이용될 수 있다. 이에, 본 연구에서는 휴대가 간편하고 수치영상의 자체 저장능력을 가진 디지털 카메라를 이용하여 촬영조건의 다양한 변화에 따른 위치오차를 분석하며, 광속 조정을 통하여 높은 정확도의 부화소 좌표를 획득하여 3차원 모니터링을 위한 기초 자료와 근거리 수치 사진측량기법의 국부지역모형생성의 활용방안을 모색하였다.

• ETRI Journal
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• 제38권5호
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• pp.858-867
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• 2016

A high dynamic range (HDR) video service is an upcoming issue in the broadcasting industry. For compatibility with legacy devices receiving a non-constant luminance (NCL) signal, new tools supporting an HDR video service are required. The current pre-processing chain of HDR video can produce color noise owing to the chroma component down-sampling process for video encoding. Although a luma adjustment method has been proposed to solve this problem, some disadvantages still remain. In this paper, we present an adaptive color noise reduction method for an NCL signal of an HDR video service. The proposed method adjusts the luma component of an NCL signal adaptively according to the information of the luma component from a constant luminance signal and the level of color saturation. Experiment results show that the color noise problem is resolved by applying our proposed method. In addition, the speed of the pre-processing is increased more than two-fold compared to a previous method.

• 대한공간정보학회지
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• 제7권1호
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• pp.53-63
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• 1999

사진측량 과정은 단위연구를 중심으로 독립적으로 수행되고 있으나 종합적이고 체계적인 연계 및 이용을 위해서는 전체를 통합하는 기반환경의 조성이 필요하다. 기존의 절차형 방식의 처리과정을 통해서는 통합환경으로 구현하기가 어려우나, 객체지향기법으로 주제별로 클래스화 할 경운 통합환경의 구현 뿐만 아니라 새로운 변경요소나 연구성과의 갱신이 용이하다. 본 연구에서는 객체지향기법으로 근거리 수치사진측량 과정을 수행하기 위해 자료입력부분에서는 사진을 수치영상으로 그 개념과 특성을 확장하여 영상의 입출력에 대한 클래스를 제작하였고 자료처리부분에서는 3자원 렌즈김정모형식으로 검정을 거친 영상에 대해 자료 처리 각 부분에 대한 클래스를 제작하여 영상정합과 좌표변환을 실시하였다. 또한 대상물의 3차원 위치를 결정하기 위해 직접선형변환과 광속조정법을 클래스화하여 사진상의 대상물과 지상물체의 관계를 모형화하였다. 본 연구의 결과, 수치사진측량 과정의 각 주제에 대해 객체지향기법으로 다단계 처리를 할 수 있는 클래스를 설계하고, 클래스들의 계층도를 구축, 수치사진측량을 위한 단일 통합환경을 구현하였고, CCD 사진기에 대한 3차원 렌즈 검증 모형식의 개발을 통해 근거리 사진측량을 수행하여 단일 통합환경에서 각각의 방법으로 대상물의 3차원 좌표를 추출할 수 있었다.

• 한국의류산업학회지
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• 제22권6호
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• pp.853-861
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• 2020

Various types of clothing are being developed to boost thermal comfort during cold winters along with research on change of body temperature when heating is applied. There is a noticeable behavioral difference by gender when using heating panels in a cold environment; however, research on women has been insufficient. This study find a temperature range that provides sustainable thermal comfort in a low temperature environment by observing temperature and change of temperature when subjects are classified according to physical activities or cold sensitivities. For the study results, 8 women in their 20s were subjected to experiment in a low temperature environment for 75 minutes (sitting position: 30 min., running: 15 min., and sitting position: 30 min.). Subjects were asked to turn on/off the heating panel freely to analyze the range of comfortable temperature and clothing microclimate; in addition, skin temperature and heating panel temperature were measured and analyzed at 9 points. As a result, temperature at which subjects turn on and off the heating panel indicated a statistically meaningful difference between the cold sensitivity group depending on exercise or non-exercise. The range of comfortable abdomen temperature was wider than the lower back and was significantly reduced when the subject was running. The range of comfortable temperature was also largest for the heating panel temperature, microclimate, and skin temperature in suggesting that adequate adjustment will be required depending on the surrounding environment or movement of the wearer.

• 한국철도학회논문집
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• 제18권5호
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• pp.457-465
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• 2015

본 연구에서는 기존선 속도향상을 위한 곡선부 개량 시 승차감을 고려한 최적평면선형범위에 대한 평가방안을 제시하였다. 또한 다양한 선형설계 초기조건들이 허용개량범위와 승차감 측면에서 최적선형 범위에 미치는 영향을 파악하기 위한 매개변수 해석을 수행하였다. 이와 더불어 현재 경부고속선에 부설되어 있는 선형조건들 중 가장 작은 곡선반경을 가진 평면선형들에 대하여 최적 개량범위를 검토하였다. 해석결과, 주요 초기선형설계변수인 곡선반경과 캔트가 클수록 허용개량범위와 최적선형범위가 넓어짐을 알 수 있었으며, 경부고속선 자갈도상구간에 부설되어 있는 R7000/R8000의 경우에도 선형측면에서는 약간의 개량으로도 속도향상이 가능함을 알 수 있었다.

• Journal of Preventive Medicine and Public Health
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• 제13권1호
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• pp.27-34
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• 1980

Purpose of this study is to find out proper means of estimating the urinary mercury excretion in the normal individuals. Whole void volume was collected every 2 hours beginning from 6 o'clock in the morning until 6 o'clock next morning. Mercury excretion in each urine specimen was measured by NIOSH recommended dithizone colorimetric method (Method No.: P & CAM 145). Urinary concentration of mercury was adjusted by two means: specific gravity of 1.024 and a gram of creatinine excretion per liter of urine comparing the data with the unadjusted ones. Mercury excretion in 24-hour urine specimen was calculated by adding the amounts measured with the hourly collected specimens of each individual. Statistical analysis of the urinary mercury excretion revealed the following results: 1. Frequency distribution curve of mercury excreted in urine of hourly specimens was best fitted to power function expressed in the form of $y=ax^b$. Adjustment of the urinary mercury concentration by creatinine excretion was shown to be superior($y=1674x^{-1.52},\;r^2=0.95$) over nonadjustment($y=2702x^{-1.57},\;r^2=0.92$) and adjustment by specific gravity of 1.024($y=4535x^{-1.66},\;r^2=0.93$). 2. Both log-transformed mercury excretion in hourly voided specimens and mercury excretion itself in 24 hour specimens showed the normal distributions. 3. The frequency distribution of mercury adjusting the urinary concentration of mercury by creatinine excretion was best fitted to a theoretical normal distribution with the sample means and standard deviation than those unadjusted or adjusted with specific gravity of 1.024. 4. Average urinary mercury excretions in 24-hour urine specimen in an individual were as follows: a) Unadjusted mercury excretion mean and standard deviation : $$18.6{\pm}13.68{\mu}gHg/l$$. median : $$16.0\;{\mu}gHg/l$$. range : $$0.0-55.10\;{\mu}gHg/l$$. b) Adjusted with specific gravity mean : $$20.7{\pm}11.76\;{\mu}gHg/l{\times}\frac{0.024}{S.G-1.000}$$ median : $$20.7\;{\mu}gHg/l{\times}\frac{0.024}{S.G-1.000}$$ range : $$0.0-52.9\;{\mu}gHg/l{\times}\frac{0.024}{S.G-1.000}$$ c) Adjusted with creatinine excretion mean and standard deviation : $$10.5{\pm}6.98\;{\mu}gHg/g$$ creatinine/l median : $$9.4\;{\mu}gHg/g$$ creatinine/l range : $$0.0-26.7\;{\mu}gHg/g$$ creatinine/l 5. No statistically significant differences were found between means calculated from 24-hour urine specimens and those from hourly specimens transformed into logarithmic values. (P<0.05).

• Environmental Analysis Health and Toxicology
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• 제28권
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• pp.15.1-15.8
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• 2013

Objectives The aim of this study was to determine the association between low-level mercury exposure and neurobehavioral functions in adults living in coastal regions of Korea. Methods We selected 172 adults aged 20-65 years living in a city in the coastal region of Korea. A sociodemographic survey was conducted, mercury levels in the blood, urine, and hair were measured, and the associations according to computerized neurobehavioral tests were determined using univariate analysis. After adjustment for associated variables, a multivariate linear regression analysis was performed. Results The geometric mean mercury levels in the blood, urine, and hair were $5.41{\mu}g/L$ (range, $0.00-15.84{\mu}g/L$), $1.17{\mu}g/g$-creatinine (range, $0.00-32.86{\mu}g/g$-creatinine), and 1.37 mg/kg (range, 0.42-6.56 mg/kg), respectively. Variables that were associated with simple reaction time according to the neurobehavioral test results were age and urine mercury level. Variables associated with choice reaction time were the recent use of Korean traditional medicine and urine mercury level. Variables associated with the right-hand finger tapping speed test were age, gender, smoking behavior, education level, monthly household income, and urine mercury level. Variables associated with the left-hand finger tapping speed test were age, gender, education level, and urine mercury level. After adjustment for associated variables, there was no significant association between urine mercury level and simple reaction time (${\beta}=25.96$; p =0.47), choice reaction time (${\beta}=50.37$; p =0.32), or the number of left-hand finger taps (${\beta}=-1.54$; p =0.21). However, urine mercury level was significantly associated with the number of right-hand finger taps (${\beta}=-3.86$; p =0.01). Conclusions We found no evidence that low-level mercury exposure in adults is associated with deficits in neurobehavioral functions. A longer follow-up study is required to confirm this conclusion.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권5호
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• pp.632-639
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• 2014

Mechanical stress and the vacuum level are the two main factors dominating the quality factor of a resonator operated in the vacuum range 1 mTorr to 10 Torr. This means that if the quality factor of a resonator is very insensitive to the mechanical stress in the vacuum range, it is sensitive to mainly the ambient vacuum level. In this paper, a wafer-level packaged MEMS resonator with a highly vacuum-sensitive quality factor is presented. The proposed device is characterized by a package with out-of-plane symmetry and a suspending structure with only a single anchor. Out-of-plane symmetry helps prevent deformation of the packaged device due to thermal mismatch, and a single-clamped structure facilitates constraint-free displacement. As a result, the proposed device is very insensitive to mechanical stress and is sensitive to mainly the ambient vacuum level. The average quality factors of the devices packaged under pressures of 50, 100, and 200 mTorr were 4987, 3415, and 2127, respectively. The results demonstrated the high controllability of the quality factor by vacuum adjustment. The mechanical robustness of the quality factor was confirmed by comparing the quality factors before and after high-temperature storage. Furthermore, through more than 50 days of monitoring, the stability of the quality factor was also certified.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 추계학술대회 논문집
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• pp.337-340
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• 2007

In the dissertation, a power conversion system for fuel cell is composed of a PWM inverter with LC filter in order to convert fuel cell voltage to a single phase 220[V], In addition, new insulated DC-DC converters are proposed in order that fuel cell voltage is boosted to 380[V]. In this paper, it requires smaller components than existing converters, which makes easy control. The proposed DC-DC converter controls output power by the adjustment of phase-shift width using switch S5 and S6 in the secondary switch, which provides 93-97[%] efficiency in the wide range of output voltage. Fuel cell simulator is implemented to show similar output characteristics to actual fuel cell. Appropriate dead time td enables soft switching to the range where the peak value of excitation current in a high frequency transformer is in accordance with current in the primary circuit. Moreover, appropriate setting to serial inductance La reduces communication loss arisen at light-load generator and serge voltage arisen at a secondary switch and serial diode. Finally, TMS320C31 board and EPLD using PWM switching technique to act a single phase full-bridge inverter which is planed to make alternating current suitable for household.