• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.593-594
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• 2011

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.3102-3107
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• 2008

This paper was focused on the particulate matter (PM) on the gasoline and bio ethanol. Bio ethanol as a clean fuel is considered one of the alternative fuels that decreased the PM emission from the vehicle. Particle formation in SI engine was depended on the fuel and engine operating condition. In this paper, Particle number concentration behaviors were analyzed by DMS500 (Differential Mobility Spectrometer) and CPC (Condensation Particle Counter) instrument which was recommended by PMP (Particle Measurement Programme). Particle emissions were measured with various engine operating variables such as air excess ratio ($\lambda$), spark timing and intake valve opening (IVO) at part load condition. In vehicle test, the number of particulate matter was analyzed with golden particle measurement system, which was consist of CVS (Constant Volume Sampler), particle number counter and particle number diluter.

• 한국전기전자재료학회논문지
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• 제23권9호
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• pp.691-695
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• 2010

A measurement method of the particle-based reflective display is proposed, estimated, and compared with reported method. The reflectivity measurement by previous studies is simply obtained by integrating sphere, but it has a limitation for the estimation of real moving particles because its data include surface reflection and incomplete attachment on electrodes. To get the number of real moving particles, the area by attached particles on the electrodes is calculated at microscopic signals. The moving particles on subthreshold voltage are observed and this fluctuational variation of surface on subthreshold voltage gives a tip to understand the driving mechanism. By this measurement we ascertained the relationship of a particle layer and real driving particles, and the feasibility of observation and estimation for moving color particles, which were measured by the reflectivity and CIE (Commission Internationale de I'Eclairage) system of color specification at previous studies.

• 대한기계학회논문집B
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• 제28권7호
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• pp.863-870
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• 2004

The temperature and soot particle measurement technique in a laminar diffusion flame has been studied to investigate the characteristics of soot particle with temperature using a co-flow burner. The temperature distribution in the flame were measured by rapid insertion of a R-type thermocouple and the soot particles by LEM/LIS techniques. In these measurement, soot volume fraction, number density and soot diameters were analyzed experimentally. As a results, the spacial distributions of particle volume fraction, soot diameter, and number density are mapped throughout the flame using the Rayleigh theory for the scattering of light by particles. A laser extinction method was used to measure the soot volume fraction and laser induced scattering method was used to measure the soot particle diameter and number density. Also, we measured temperature without the effect of soot particles attached to the thermocouple junction, which is close to the nozzle. In this result, we found that upstream zone has a unstable flowing in co-flow diffusion flame and the y-axis temperature of flame has a uniform temperature distribution in the most soot volume fraction zone.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1267-1273
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• 2004

The temperature and soot particle measurement technique in a laminar diffusion flame have been studied to investigate the characteristics of soot particle with temperature using a co-flow burner. The temperature distributions in the flame were measured by rapid insertion of a R-type thermocouple and the soot particles were detected were detected by LEM/LIS techniques. In these measurement, soot volume fraction, number density and soot diameters were analyzed experimentally. As a results, the spacial distributions of particle volume fraction, soot diameter, and number density are mapped throughout the flame using the Rayleigh theory for the scattering of light by absorbing particles. A laser extinction method was used to measure the soot volume fraction and Laser induced scattering method was used to measure the soot particle diameter and number density. Also, we measured temperature without the effect of soot particles attached to the thermocouple junction, which is close to the nozzle. In this result, we found that upstream zone has a unstable flowing in co-flow diffusion flame and the y-axis temperature of flame has a uniform temperature distribution in the most soot volume fraction zone.

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권5호
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• pp.596-608
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• 2018

The present study aims to assess test uncertainty assessment method of nominal wake field measurement by a Stereoscopic Particle Image Velocimetry (SPIV) system in a towing tank. The systematic uncertainty of the SPIV system was estimated from repeated uniform flow measurements. In the uniform flow measurement case, time interval between image frames and uniform flow speed were varied to examine the effects of particle displacement and flow around the SPIV system on the systematic standard uncertainty. The random standard uncertainty was assessed by repeating nominal wake field measurements and the estimated random standard uncertainty was compared with that of laser Doppler velocimetry. The test uncertainty assessment method was applied to nominal wake measurement tests of a very large crude oil carrier model ship. The nominal wake measurement results were compared with existing experimental database by other measurement methods, with its assessed uncertainty.

• 한국환경과학회지
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• 제23권2호
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• pp.323-330
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• 2014

Transport of bed load and suspended particle in coastal waters is main factor causing change in shoreline, and effective measurement method and appropriate equipment is required. To measure bed load and suspended particle transport an equipment was designed and manufactured, and it was applied in the field. The equipment consists of four main elements, body supporter, bed load and suspended particle sampler, sampler support and lock. Eight samplers were installed along the circumference of each supporter, and each sample is a 45-degree intervals. The field experiment was done once along Gyeongpo beach in August 2013. This note described the design and function of the equipment and results of field experiments.

• 한국입자에어로졸학회지
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• 제16권2호
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• pp.49-59
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• 2020

Various devices have been developed to the measurement of particulate matter pollutants, and Optical Particle Counter (OPC) that can be easily and quickly measured is widely used lately. The measured value by OPC is converted to weight concentration using the correction factor (CF). The calculation of CF is very important to improve the reliability and accuracy of OPC. In this study, the CF calculation study of light scattering laser photometer (model 8533, TSI) was carried out to measure in the atmospheric environment using 2 gravimetric devices and 3 light scattering laser photometer devices. Regression analysis and Tukey tests were used to significance the test of measurement devices. Measurements were carried out twice. There was a comparative analysis of measurement data between light scattering laser photometer and gravimetric devices in 1st measurement, and then the Evaluation of PM2.5 concentration corrected by CF performed in 2nd measurement. As a result of the significance analysis between light scattering laser photometer and gravimetric devices, the correlation between the same method was high, but the correlation between different methods was low. CF was calculated as 0.4258 based on the measurement results, and it is a similar level to previous studies at home and abroad. It is expected that these results can be used as basic data in the future study for air quality measurement research using light scattering laser photometer. Also, in order to improve the accuracy of the measurement techniques and the development of technology in the atmospheric environment, CF calculation research should be conducted continuously.

• 대한설비공학회지:설비저널
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• 제16권5호
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• pp.441-452
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• 1987

• 한국입자에어로졸학회지
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• 제7권1호
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• pp.21-30
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• 2011

The spatial distributions of air pollutants, in particular, ultrafine particles near traffic congestion roads at urban areas need to reduce human exposure levels for protecting public health. In this study, the number concentrations of ultrafine particles larger than 5 nm were measured every second during driving on the major roads of Nowon-gu, Seoul for 1.6 h using a mobile emission laboratory on October 5, 2010. The ultrafine particle number concentrations ranged from 7,009 to $265,600particles/cm^3$ with an average of $55,570particles/cm^3$, and these levels were comparable to concentrations of ultrafine particles larger than 3 or 7 nm on the arterial roads at urban areas in Los Angeles, USA and Zurich, Switzerland. It was frequently observed that the ultrafine particle number increased rapidly when vehicle speed was accelerated and it decreased sharply when vehicle speed was decelerated. The high peak events of ultrafine particle concentration larger than $200,000particles/cm^3$ were observed seven times during the measurement period. From the three repeated measurements during the short period of 50 min, it was concluded that the ultrafine particle number concentration on the road was significantly time-dependent. This on-road measurement approach can be utilized to manage vehicle-related air pollution in urban.