In this study, acoustic and viscosity data are collected in real time during the ball milling process and analyzed for correlation. After fast Fourier transformation (FFT) of the acoustic data, changes in the signals are observed as a function of the milling time. To analyze this quantitatively, the frequency band is divided into 1 kHz ranges to obtain an integral value. The integrated values in the 2–3 kHz range of the frequency band decrease linearly, confirming that they have a high correlation with changes in viscosity. The experiment is repeated four times to ensure the reproducibility of the data. The results of this study show that it is possible to estimate changes in slurry properties, such as viscosity and particle size, during the ball milling process using an acoustic signal.

PURPOSES : The purpose of this study is to develop a service volume for signal metering on roundabouts to increase applicability of roundabout in Korea. METHODS: To develop the service volume for signal metering on roundabouts, traffic simulation studies were conducted using VISSIM software for various scenarios based on traffic volumes as approaches and location of detectors on controlling approach lane. Typically, the Vehicle Actuated Programming module in VISSIM was applied for analyzing more realistic traffic signal control conditions. RESULTS: As the left-turning volume is increased, the delay reduction rates were increased. And the case of 40 meter distance of a detector and 20 seconds red signal phase made better results. CONCLUSIONS: The signal metering on roundabout should be applied carefully because it is possible to lose roundabout strengthen in traffic operation aspect. The service volume for signal metering on roundabouts that suggested from this study is useful to decide the application of signal metering on roundabout.

PURPOSES : This study was conducted to develop expressway safety treatments based on the analysis results of older driver behaviors through literature review, surveys, and driving simulator experiments. METHODS: In this study, three analyses were conducted: surveys of 700 older drivers to find the risk segments they recognized, driving simulator experiments with older and younger drivers to investigate driver behaviors, and expert surveys to find the priority of expressway safety treatments for older drivers. RESULTS : Through survey results it was found that merging areas and tunnels were identified as the most dangerous areas, and more dangerous older driver behaviors were observed on those expressway segments in the driving simulator experiments. In addition, the priorities of safety treatments for each segment of expressways were decided based on expert surveys. CONCLUSIONS: It was concluded that choice and concentration strategies of expressway safety treatments for older drivers should be applied as perceptions regarding dangerous spots and older driver behaviors, including geometric designs, safety facilities, regulation, and institutes to improve expressway safety.

쳇 베이커의 시대별 보컬 스타일 변화에 관한 연구는 대중음악 논문 분야에서 잘 다뤄지지 않 은 관점이다. 이 연구에는 베이커가 활동했던 시기에 따른 보컬 스타일 변화를 도출하며 분석된 보컬 스타일을 통해 시대가 지남에 따라 드러나는 그의 보컬 스타일 특징을 선율 변주 기법으로 제시하는 것이 목적이다. 이 연구를 위해 쳇 베이커의 생애 주기를 전기 후기로 나누고 한 곡이 전기 후기에 각각 다른 버전으로 녹음 되었던 두 곡을 선정한다. 선정된 곡은 리얼북을 원곡으로 선정하고 비교 분석하여 시대별로 비교 분석한다. 선정된 2곡에 나타난 시대별 특징을 서로 비교 하여 도출해낸 공통된 변화를 통해 시대에 따른 쳇 베이커의 변화된 보컬 스타일을 제시한다. 쳇 베이커의 시대별 스타일 변화 연구를 통해 후기로 가면서 음과 리듬의 변화가 더욱 확대된 것을 볼 수 있고 노래를 재해석하여 자신만의 가사를 추가해 개성을 더하였으며 그의 노래는 시 대가 지나면서 규칙성 있는 선율 변주로 발전되었음을 확인하는 결과를 도출하였다.

악기를 능숙하게 연주하기 위해 구조와 기능을 아는 것은 매우 중요하다. 사람은 목소리를 악 기로 사용하지만, 목소리를 내는 기관은 만질 수 없고 눈에 보이지 않기 때문에 접근하기 어렵 다. 그래서 해부학적으로 접근해야만 구조를 알게 된다. 우리가 몸 안의 기관을 해부학적으로 정확하게 인식하는 것이 운동기능 향상에 영향을 준다. 이것을 ‘운동 감각’을 통해 증명한다. 공명과 턱관절 및 근육의 정의와 기능을 알고 ‘턱 근육의 올바른 사용’이 발성의 ‘공명’에 미치는 영향을 알았을 때 우리는 가창에 필요한 운동기능을 훈련할 수 있게 된다. 이 훈련을 통 해 턱 근육과 발성 기관을 인지하여 가창했을 때 부정적인 주변 환경, 심리상태와 상관없이 좋은 공명의 가창을 할 수 있도록 훈련할 수 있다. 또한, 추상적인 표현의 교수법 등으로 교사의 경험 이 학생에게 제대로 전달되지 못하는 경우가 많다. 발성 기관의 해부학적 접근을 통해 교사와 학생의 거리를 좁힐 수 있는 직접적이고 효과적인 교수법을 제시한다.

The performance of organic Rankine cycle was numerically investigated to recover heat from the exhaust of a heavy-duty diesel engine. Exhaust flow rates and temperatures are obtained from the simulation of diesel cycle by using GT-Power. The net power outputs of organic Rankine cycle for 9 working fluids were calculated by cycle simulations. The results showed that as for the net power outputs and the pressure of working fluids, R21 and R245fa are suitable as working fluids for ORC in diesel engine.

PURPOSES: Nighttime driving is very different from daytime driving because drivers must obtain nighttime sight-distances based on road lights and headlights. Unfortunately, nighttime driving conditions in Korea are far from ideal due to poor lighting and an insufficient number of road lights and inadequate operation and maintenance of delineators. This study is conducted to develop new standards for nighttime road visibility based on experiments of driver perception for nighttime visibility conditions. METHODS : In the study, perception level and satisfaction of nighttime visibility were investigated. A total of 60 drivers participated, including 34 older drivers and 31 young drivers. To evaluate driver perceptions of nighttime road visibility, fuzzy set theory was used because the conventional analysis methods for driver perception are limited in effectiveness for considering the characteristics of perception which are subjective and vague, and are generally expressed in terms of linguistic terminologies rather than numerical parameters. RESULTS : This study found that levels of nighttime visibility, as perceived by drivers, are remarkably similar to their satisfactions in different nighttime driving conditions with a log-function relationship. Older drivers evaluated unambiguously degree of nighttime visibility but evaluations by young drivers regarding it were unclear. CONCLUSIONS : A minimum value of brightness on roads was established as YUX 30, based on final analyzed results. In other words, road lights should be installed and operated to obtain more than YUX 30 brightness for the safety and comfort of nighttime driving.

The objective of this study is to censure the provision of correct information to the public through investigating radon emanation by building materials that are used in domestic construction environment. Radon emanation has been identified in 10 framing materials and 16 finishing materials of 26 building materials used in the domestic construction-industry. Radon emanation was measured using the closed chamber method based on CR-39 nuclear track detectors(NTDs). On Brick-General in framing materials, the highest radon emanation rates were 0.60028 Bq/ m2·h for surface and 0.00733 Bq/kg·h for mass, while on Ceiling-Tex Cement Plaster in finishing materials. The highest radon emanation rates were 0.47708 Bq/m2·h for surface and 0.05885 Bq/kg·h for mass.