Although the proportion of coal-fired power generation is decreasing, efficient operating technology is needed to continuously invest in facilities and reduce maintenance costs until it is abolished. Boilers, one of the main facilities of power plants, operate for a long time in harsh environments of high temperature and high pressure. In addition, damage due to deterioration is likely to occur depending on the fuel and tube material used. It is very important to judge soundness because damage caused by deterioration adversely affects facility operation. Previously, replication method was used to analyze the progress of deterioration. In the replication method, pre-treatment such as chemical treatment is performed on the boiler tube in the field, the area is reproduced by attaching a film, and the replicated film is determined by an expert in the laboratory with an expensive microscope. However, this method involves substantial costs and time requirements, as well as the possibility of human errors. To address these issues, we developed a mobile health assessment system in this research. Since it is detachable and takes images in real time, this system enables swift evaluations across a broad range and facilitates the assessment of preprocessing quality. In addition, it was intended to reduce existing human mistakes by developing a degradation classification algorithm using the merger cluster method.

작물 수분스트레스 지수(CWSI; Crop Water Stress Index)를 통해 관개 시기를 판단할 경우, 정확한 잎의 온도 및 대기 환경을 측정하는 것이 중요하다. 그리하여 본 연구에서는 실시간으로 작물의 생체정보(엽온) 및 대기 환경(대기온·습도, 일사량)을 측정하고 자동으로 CWSI 값이 산정되는 휴대용 수분스트레스 계측기기를 개발하였다. 또한 휴대용 수분스트레스 계측기기와 고정식 온도 측정 방법과의 비교 분석을 통해 휴대용 수분스트레스 계측기기의 성능을 평가하고자 하였다. 본 계측기기는 CWSI 산정을 위한 생체신호 및 기상 데이터를 측정하는 센싱부, 측정된 데이터를 저장하고 CWSI를 산정하는 데이터 수집부, 장치의 기능을 조작하고 측정값을 표시하는 시스템 제어부로 구성하였다. T-test를 실시하여 두 계측 방법에서 측정된 엽온, 일사량, CWSI 평균값의 유의 관계를 분석한 결과, 유의확률은 0.089, 0.318 그리고 0.028로 각각 나타났다. 엽온과 일사량은 유의수준 0.05보다 크므로 유의미한 차이가 나타나지 않았지만 CWSI는 유의확률이 유의수준보다 작으므로 두 측정 방법에 따라 유의미한 차이가 나타났다.

PURPOSES : The retroreflectivity of pavement markings for road safety was evaluated. METHODS : Field tests of pavement markings, which are characters, symbols, crosswalks, and stop lines, but do not include line markings, were conducted using a portable retroreflectometer with the purpose of evaluating the retroreflectivity according to the type of pavement markings and roads. Furthermore, changes in retroreflectivity due to wheel passing and wet conditions were evaluated. Here, 192 test points for evaluating the retroreflectivity of pavement markings, 5 test points for evaluating reductions in retroreflectivity during conditions of wetness, and 28 test points for checking variability due to type of testing device were selected on major and minor arterial roads in Seoul. RESULTS : The average retroreflectivity of pavement markings measured in this study was 115.7 (mcd/m2·lux), which is lower than the minimum retroreflectivity required six months after installation but higher than the minimum remarking retroreflectivity required by Seoul city. The retroreflectivity of pavement markings measured on minor arterial roads was 69.1% of that on major arterial roads. The average retroreflectivity of pavement markings was reduced to 43.1% by wheel passing, which is below the remarking criterion. The average retroreflectivity measured on wet pavement markings was 43.7 (mcd/m2·lux), which is a ninth of that under dry conditions. The test results showed that retroreflectivity in the rain was much lower than the required value in the case of rain, which is 175 mcd/m2·lux, as issued by Seoul city. Compared with mobile retroreflectometers, a portable retroreflectometer produced 17% higher retroreflectivity based on the results of 28 test points. CONCLUSIONS : Based on the field tests, the retroreflectivity of pavement markings, i.e., characters, symbols, crosswalks, and stop lines, was higher than the average remarking criterion. However, the retroreflectivities of pavement markings passed by the wheel or in rain were lower than the remarking criteria. Considering that the remarking criteria in Seoul city are higher than those in Europe and the test results in this study indicate much lower values than those required in Seoul, further study is necessary to be able to properly modify the criteria for retroreflectivity.

목적 : 본 연구에서는 다양한 방법들을 이용하여 토릭렌즈 마킹 회전량을 평가할때 일치도를 평가측정하고자 하였다. 방법 : 모형안과 콘택트렌즈 착용이 가능한 57안(평균 24.79±1.29세)을 대상으로 토릭소프트렌즈를 제조사의 가이드라인에 따라 피팅한 후, 사진 촬영, 각도기 어플리케이션, 휴대용 돋보기와 세극등 현미경을 사용하여 회전 평가를 진행했을 때의 서로 다른 검사자 간의 검사 결과값을 비교 분석하였고, 서로 다른 회전평가 방법 간의 일 치도는 블랜드 알트만 분석을 사용하였다. 결과 : 서로 다른 검사자 간 같은 회전평가 방법으로 토릭소프트렌즈의 회전량을 측정하였을 때, 측정값의 평 균 차이가 사진 촬영, 각도기 어플리케이션, 휴대용 돋보기, 세극등 현미경 평가 방법 각각 –0.50, -0.70, -0.30, -0.13°로 유사한 결과를 보였다. 회전평가 방법 간 비교에 대해서는 사진 촬영과 각도기 어플리케이션을 사용했을 때, 허용 오차 범위(5°) 내의 측정값이 각각 74.56%, 75.44%로 비교적 낮은 신뢰도를 보였고 휴대용 돋 보기를 사용한 방법에서는 95.61%로 높은 신뢰도를 보였다. 결론 : 토릭소프트렌즈 처방에서 세극등 현미경을 사용할 수 없어도 사진 촬영, 핸드폰 각도기 어플리케이션, 휴대용 돋보기를 통해 토릭소프트렌즈 회전평가에 대한 임상적으로 유용한 결과를 얻을 수 있다.

본 논문에서는 상용코드인 ANSYS CFX를 통한 해양레저 스포츠 및 야외 활동 시 사용 가능한 휴대용 수평축 수차의 유입유속(U) 및 주속비(TSR, Tip Speed Ratio) 변화에 따른 성능해석을 수행하였으며, 해석결과 및 유동장 분석을 통해 설계에 대한 검토 및 장치의 성능을 확인하였다. 또한, 추가적으로 블레이드의 피치각도(αpitch) 변화에 따른 성능해석을 통해 수차의 성능개선에 필요한 데이터를 획득하고자 하였다. 본 논문의 연구 결과 수치해석 케이스 중 주속비 4인 경우, 모든 유입속도 및 블레이드 피치 각도에서 가장 높은 성능을 보였으며, 설계 유속 이하의 일부 조건에서도 설계 출력인 30 W 이상의 출력을 보였다. 그리고 수치해석 케이스 중 가장 높은 출력과 출력계수는 유입유속 1.5 m/s, 블레이드 피치 각도 3°, 주속비 4에서 보였으며, 출력 약 85 W, 출력계수 약 0.30이었다.

This paper suggests a nonlinear pressure consideration scheme through an unsteady pipe network analyzer for leakage detection with a portable pressure wave generator. In order to evaluate the performance of a proposal scheme, linear input pattern has been simulated and experiments had been carried out under both no leakage and one leakage conditions in a reservoir-pipeline-valve system. This method using portable pressure wave generator showed that a leakage can be detected from a reflection where a leakage is originated through time domain analysis. Meaningful similarity in pressure response between nonlinear input pattern and experimental results were found both no leakage and a leakage conditions.

목적 : 소아의 굴절이상을 타각적 굴절검사인 탁상용 자동굴절검사기, 검영기와 휴대용 사진굴절검사기로 측정 하여 비교하였으며 휴대용 자동굴절검사기의 임상적 유용성에 대해 알아보고자 하였다. 방법 : 103명의 소아(206안)에게 탁상용 자동굴절검사기, 검영기, 휴대용 사진굴절검사기를 이용하여 굴절이상을 측정하였다. 각각의 기기에서 구면 굴절력, 난시 굴절력, 난시 축을 paired t-test로 분석하여 평균 차와 95% LoA를 구하였다. 측정된 굴절이상의 일치도를 분석하기 위해 Bland-Altman plot을 이용하였으며 기기 간의 상관관계를 조사하기 위해 Spearman 상관분석을 시행하였다. 결과 : Bland-Altman plot에서 구면 굴절력과 난시 굴절력에서는 휴대용 사진굴절검사기와 검영기에서 높은 일치도를 보였으며 난시 축은 탁상용 자동굴절검사기와 검영기에서 높은 일치도를 보였다. 탁상용 자동굴절검사기에서 근시쪽으로 측정되었으며 근시와 원시에서는 검영기보다 휴대용 사진굴절검사기가 근시 쪽으로 측정되었다. 또한 구면 굴절력, 난시 굴절력과 난시 축에서 휴대용 사진굴절검사기와 검영기가 높은 상관관계를 보였다. 구면 굴절력과 난시 굴절력은 휴대용 사진굴절검사기와 검영기가 유사한 굴절 값으로 나타났다. 난시 축은 검영기와 탁상용 자동굴절검사기가 유사한 측정치를 보이긴 했으나 측정기기에 따라 약간의 차이를 보였으며 통계적으로 유의한 차이는 없는 것으로 나타났다. 결론 : 협조가 부족한 소아에서 휴대용 사진굴절검사기는 빠르게 굴절이상을 측정할 수 있으며 정확한 자세에서 검사하게 되면 유용하게 사용될 수 있다.

Gas burner has been widely utilized to many industrial fields and personal outdoor activities and so on. Portable small-sized gas burner is, especially, useful in personal outdoor activities. The performance and safety of portable small-sized gas burner is important because it uses gas as fuel. The purpose of this study was to investigate the possibilities of performance improvement of portable small-sized gas burner through flow and structural analysis, respectively. As the results, it showed that mass fraction of butane gas in all cases(Type 1, Type 2, Type 3) was about 12~18% and further safety load of 3 stand leg was below 10 kgf.

The purpose of this study is to create a new odor analysis technology that combines the separation technology of GC and the measurement of MOS sensors. The detector of the GC system is replaced with the MOS sensor to analyze various odor compounds. Carrier gas also used air in the normal atmosphere through a micro pump. Therefore, it is possible to develop a portable odor analysis device since no additional cylinder is needed. Retention times for H2S, C7H8, and C2H4O analyzed by the combined GC/MOS system were identified as 1.28 minutes, 3.88 minutes and 1.77 minutes, respectively. Measurement reproducibility of odorous RT was very good at less than 1.2 %RSD. Also, the magnitude of the peak as a result of changes in the concentration of each odor showed a linear proportional relationship. Thus, a new method could be proposed to analyze various odorous substances with the combined GC/MOS system.

PURPOSES: The purpose of this study is to verity the applicability of a portable small-loop electromagnetic survey method to underground cavity detection. METHODS: In order to evaluate applicability of the method, a test bed comprised of four sections was constructed. The two sizes of the four cavities artificially formed at two depths were contained in the test bed. Each cavity was positioned at center of each 6 m long section. Four types of pavement materials such as unpaved ground, bricks, asphalt, and concrete were used at every section. The portable small-loop electromagnetic device measured electrical conductivity as an exploration signal that varied according to the electrical properties underground. The electrical conductivity was converted into two-dimensional electrical resistivity distribution sections using an inverse analysis program. RESULTS : The results showed that the electrical resistivity of the non-cavity area was lower than that of the cavity area. The electrical resistivity increased as the measurement device moved closer to the cavity position. It was also found that the electrical resistivity values were not significantly affected by pavement type. The small cavity with diameter of 35 cm could be detected up to 1.2 m depth. CONCLUSIONS: Therefore, it was verified that the portable small-loop electromagnetic survey method is applicable to the detection of cavities in sections where ground subsidence is expected. This method can be effectively used for small-scale roads such as sidewalks, parkways, and side streets where large exploration equipment cannot enter.

Many studies for personal mobility are increasing at the latest. One part of personal mobility study is electric scooter. Driving elements of electric scooter are battery and motor, patterns of vehicle being proposed multiply by manufacturer. The old and the infirm's population in domestic and abroad increases day by day. Thus, the personal vehicle for them that can be managed easily is needed for them. Following the trend “personal mobility”, this study propose electric-drive scooter which is portable and compact. Prototypes of proposed models are manufactured to commercialize it. As results, adopt of foldable type at electric scooter can be decreased size. Also 4-wheel scooter is more stable than 3-wheel sooter.

As a macroscopic research for the interaction of mobile game platform, I have analyzed the differentiation & characteristic of interaction for each platform. ‘Game & Watch’ was the first handheld game console released by Nintendo in 1980, the initial model was merely a combination of clock and game consoles to emphasize mobility. However, ‘Game&Watch:DonkeyKong’ which equipped with Yokoi Gunpei’s cross key provided an opportunity for the development of a full-fledged multi-screen gaming. ‘GameBoy’ was the beginning of a portable game machine in the modern sense. It has brought a lot of changes for the gameplay pattern using the contrast of color, smooth animation, as well as interchangeable cartridge system. Also, ‘NDS(Nintendo DS)’, which had several interaction system such as dual screen, voice input and touch input, had contributed to expanding the emergence of innovative game content and women game users. ‘PSP(Playstation Portable)’ by SONY in 2004 materialized 3D games using high performance and progressed to multimedia platform.