• 한국수소및신에너지학회논문집
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• 제30권6호
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• pp.593-600
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• 2019

The combustion characteristics of methane/hydrogen pre-mixed flame have been investigated with swirl stabilized flame in a laboratory-scale pre-mixed combustor with constant heat load of 5.81 kW. Hydrogen/methane fuel and air were mixed in a pre-mixer and introduced to the combustor through a burner nozzle with different degrees of swirl angle. The effects of hydrogen addition and swirl intensity on the combustion characteristics of pre-mixed methane flames were examined using particle image velocimetry (PIV), micro-thermocouples, various optical interference filters and gas analyzers to provide information about flow velocity, temperature distributions, and species concentrations of the reaction field. The results show that higher swirl intensity creates more recirculation flow, which reduces the temperature of the reaction zone and, consequently, reduces the thermal NO production. The distributions of flame radicals (OH, CH, C₂) are dependent more on the swirl intensity than the percentage of hydrogen added to methane fuel. The NO concentration at the upper part of the reaction zone is increased with an increase in hydrogen content in the fuel mixture because higher combustibility of hydrogen assists to promote faster chemical reaction, enabling more expansion of the gases at the upper part of the reaction zone, which reduces the recirculation flow. The CO concentration in the reaction zone is reduced with an increase in hydrogen content because the amount of C content is relatively decreased.

• 조명전기설비학회논문지
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• 제22권8호
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• pp.82-88
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• 2008

본 논문은 전해액에 의해 양전극 사이에 형성되는 브리지가 트래킹에 미치는 영향을 기술하고 있다. IEC(International Electrotechnical Commission) 60589의 방법으로 만들어진 1, 3, 5[wt%] NaCl 용액을 이용하여 KS C IEC 60112의 전극에서 트래킹 실험을 하였다. 트래킹 진전과정 중에서 브리지가 형성되었을 때의 전압, 전류, 저항 및 열화상을 측정하여 분석하였다. 그 결과 전해액의 전도율이 커짐에 따라 브리지에서 발생되는 줄열도 커졌다. 하지만 전해액의 기화열로 인해 전해액의 끓는점을 넘지는 못했다. 다만, 전해액의 전도율이 커짐에 따라 건조대 형성에 소요되는 시간이 짧아졌다. 따라서 다음 적하까지 보다 긴 시간동안 건조대를 유지함으로써, 방전 기회가 증가하기 때문에 트래킹 진전이 빨라짐을 알 수 있었다.

• 센서학회지
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• 제15권4호
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• pp.237-244
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• 2006

Atomic force microscope (AFM) has become a common tool for the structural and physical studies of biological macromolecules, mainly because it provides the ability to perform experiments with samples in a buffer solution. In this study, structure of proteins and nucleic acids has been studied in their physiological environment that allows native intermolecular complexes to be formed. Cr and Au were deposited on p-Si (100) substrate by thermal evaporation method in sequence with the thickness of $200{\AA}$ and $500{\AA}$, respectively, since Au is adequate for immobilizing biomolecules by forming a self-assembled monolayer (SAM) with semiconductor-based biosensors. The SAM, streptavidin and biotin interacted each other with their specific binding energy and their adsorption was analyzed using the Bio-AFM both in a solution and under air environment. A silicon nitride tip was used as a contact tip of Bio-AFM measurement in a solution and an antimony doped silicon tip as a tapping tip under air environment. Actual morphology could also be obtained by 3-dimensional AFM images. The length and agglomerate size of biomolecules was measured in stages. Furthermore, $R_{a}$ (average of surface roughness) and $R_{ms}$ (mean square of surface roughness) and surface density for the adsorbed surface were also calculated from the AFM image.

• 대한의용생체공학회:의공학회지
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• 제32권2호
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• pp.127-133
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• 2011

Arteria radialis is a branch of the brachial artery extending down the forearm around the wrist where it closes to skin surface. In the oriental medicine, the skin above arteria radialis has an important role because oriental medicine practitioners put their finger tips on the area, and diagnose patient's health conditions by feeling the pulsation of the arterial contraction. The finger tip diagnostic method relies on subjective decision of the practitioner; and there is a need to develop an objective diagnostic modality. The pulsation of the arterial contraction appears not only a movement on the site but also as temperature fluctuation due to pulsatile feeding of warmer blood. The goal of this study is to demonstrate a feasibility of using an infrared camera quantitatively to detect the temperature fluctuation on the skin. Clinical important three different areas, called chon, gwan, chuk, near a wrist where the arteria radialis reaches close to skin surface are marked with small pieces of surgical tape. A high-speed and high-resolution infrared camera with a 3 cm of field of view measures these areas for 10 second at 200 frames per second with a 320*240 pixel size. The pulsatile temperature fluctuation is calculated after passing a band pass filter to remove any stationary temperature over 10 second. The temperature fluctuation of a healthy male volunteer is measured at a room temperature as a control, and is compared with another measurement performed after 20 minutes staying in a room at a 40 degree Celsius. This comparison is repeated for three times, and indicates that the fluctuation increases after staying 20 minutes in the warm room. This increase becomes smaller when the person stays in the warm room with an acupuncture treatment that decreases body temperature. So that an objective diagnostics on the site may become feasible.

• KIEAE Journal
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• 제17권5호
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• pp.95-100
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• 2017

Purpose: The purpose of this study is to investigate the prior art based on deep learning to objectively calculate the metabolic rate which is the subjective factor for the PMV optimum control and to make a plan for future research based on this study. Methods: For this purpose, the theoretical and technical review and applicability analysis were conducted through various documents and data both in domestic and foreign. Results: As a result of the prior art research, the machine learning model of artificial neural network and deep learning has been used in various fields such as speech recognition, scene recognition, and image restoration. As a representative case, OpenCV Background Subtraction is a technique to separate backgrounds from objects or people. PASCAL VOC and ILSVRC are surveyed as representative technologies that can recognize people, objects, and backgrounds. Based on the results of previous researches on deep learning based on metabolic rate for occupational metabolic rate, it was found out that basic technology applicable to occupational metabolic rate calculation technology to be developed in future researches. It is considered that the study on the development of the activity quantity calculation model with high accuracy will be done.

• 비파괴검사학회지
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• 제30권2호
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• pp.104-109
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• 2010

겹치기 마찰교반용접은 새로운 고상접합법이다. 알루미늄 합금 6061-T6는 좋은 내식성과 중량 대비 높은 기계적 강도로 인해 넓은 분야에서 경량부재로 사용되고 있다. 본 논문에서 사용한 검사 방법인 위상잠금 초음파 적외선열화상기법은 넓은 면적을 동시에 검사할 수 있으며, 결함부와 건전부 사이의 위상차로부터 결함의 유무를 판단할 수 있다. 본고의 연구로부터, 위상잠금 적외선열화상기술을 이용하여 용접부의 열영상을 검출하여 기계적 강도와 비교 평가하였다.

• 대한원격탐사학회지
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• 제15권4호
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• pp.297-305
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• 1999

Ocean Scanning Multispectral Imager (OSMI) is a payload on the KOMPSAT satellite to perform global ocean color monitoring for the study of biological oceanography. The instrument images the ocean surface using a wisk-broom motion with a swath width of 800km and a ground sample distance (GSD) of < 1km over the entire field of view (FOV). The instrument is designed to have an on-orbit operation duty cycle of 20% over the mission lifetime of 3 years with the functions of programmable gain/offset and on-board image data compression/storage. The instrument also performs sun and dark calibration for on-board instrument calibration. The OSMI instrument is a multi-spectral imager covering the spectral range from 400nm to 900nm using CCD Focal Plane Array (FPA). The ocean colors are monitored using 6 spectral channels that can be selected via ground commands. KOMPSAT satellite with OSMI was integrated and the satellite level environment tests including instrument aliveness/functional test, such as launch environment, on-orbit environment (Thermal/Vacuum) and EMI/EMC test were performed at KARl. Test results met the requirements and the OSMI data were collected and analyzed during each test phase. The instrument is launched on the KOMPSAT satellite on December 21,1999 and is scheduled to start collecting ocean color data in the early 2000 upon completion of on-orbit instrument checkout.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2019년도 학술발표회
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• pp.152-152
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• 2019

This study demonstrates a novel approach of remotely sensed estimates of stream flow at fifteen hydrological station in the Han River Basin, Korea. Multi-temporal data of the European Space Agency's Sentinel-1 SAR satellite from 19 January, 2015 to 25 August, 2018 is used to develop and validate the flow estimation model for each station. The flow estimation model is based on a power law relationship established between the remotely sensed surface area of water at a selected reach of the stream and the observed discharge. The satellite images were pre-processed for thermal noise, radiometric, speckle and terrain correction. The difference in SAR image brightness caused by the differences in SAR satellite look angle and atmospheric condition are corrected using the histogram matching technique. Selective area filtering is applied to identify the extent of the selected stream reach where the change in water surface area is highly sensitive to the change in stream discharge. Following this, an iterative procedure called the Optimum Threshold Classification Algorithm (OTC) is applied to the multi-temporal selective areas to extract a series of water surface areas. It is observed that the extracted water surface area and the stream discharge are related by the power law equation. A strong correlation coefficient ranging from 0.68 to 0.98 (mean=0.89) was observed for thirteen hydrological stations, while at two stations the relationship was highly affected by the hydraulic structures such as dam. It is further identified that the availability of remotely sensed data for a range of discharge conditions and the geometric properties of the selected stream reach such as the stream width and side slope influence the accuracy of the flow estimation model.

• 한국추진공학회지
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• 제20권4호
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• pp.40-49
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• 2016

본 연구의 목적은 저선회 모델 연소기에서 저선회 연소의 특성을 확인하는 것이다. 이를 위해 선회각도에 따른 화염의 형상 및 안정화 영역, 배기성능에 대한 평가가 실험적으로 수행되었다. 저선회 연소의 큰 특징은 화염이 부상되어 존재하게 되는데, 이러한 부상화염은 확대유동과 예혼합 화염의 전파특성이 절묘하게 결합되어 발생하게 된다. 본 연소기에서 이러한 부상화염의 특징을 속도 유동장을 통하여 확인하였으며 화염을 가시화하여 나타내었다. 가시화된 화염은 열용량과 당량비에 따라 분류하였다. 선회각도의 변화에 따른 연구를 통해 선회각도만으로도 희박 가연한계를 확장시킬 수 있음을 보였다. 또한 선회각도가 증가할수록 혼합이 향상되고 체류시간이 짧아져 NOx와 CO의 배출이 감소되는 것으로 확인되었다.

• 전기전자학회논문지
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• 제25권3호
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• pp.430-436
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• 2021

비접촉형 체온 측정 시스템은 광학 및 열화상 카메라를 활용하여 집단시설의 발열성 질병을 관리하는 핵심 요소 중 하나이다. 기존 체온 측정 시스템은 딥러닝 기반 얼굴검출 알고리즘이 사용되어 얼굴영역의 단순 체온 측정에는 활용할 수 있지만, 의사표현이 어려운 영유아의 이상 징후를 인지하는데 한계가 있다. 본 논문에서는 기존의 체온 측정 시스템에서 영유아의 이상징후 감지를 위해 표정인식 알고리즘을 개선한다. 제안된 방법은 객체탐지 모델을 사용하여 영상에서 영유아를 검출한 후 얼굴영역을 추출하고 표정인식의 핵심 요소인 눈, 코, 입의 좌표를 획득한다. 이후 획득된 좌표를 기반으로 선택적 샤프닝 필터를 적용하여 표정인식을 진행한다. 실험결과에 따르면 제안된 알고리즘은 UTK 데이터셋에서 무표정, 웃음, 슬픔 3가지 표정에 대해 각각 2.52%, 1.12%, 2.29%가 향상되었다.