• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.273-275
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• 2005

Active thermography is being used since several years for remote non-destructive testing. It provides thermal images for remote detection and imaging of damages. Also, it is based on propagation and reflection of thermal waves which are launched from the surface into the inspected component by absorption of modulated radiation. For energy deposition, it use external heat sources (e.g., halogen lamp or convective heating) or internal heat generation (e.g., microwaves, eddy current, or elastic wave). Among the external heat sources, the ultrasound is generally used for energy deposition because of defect selective heating up. The heat source generating a thermal wave is provided by the defect itself due to the attenuation of amplitude modulated ultrasound. A defect causes locally enhanced losses and consequently selective heating up. Therefore amplitude modulation of the injected ultrasonic wave turns a defect into a thermal wave transmitter whose signal is detected at the surface by thermal infrared camera. This way ultrasound thermography(UT) allows for selective defect detection which enhances the probability of defect detection in the presence of complicated intact structures. In this paper the applicability of UT for fast defect detection is described. Examples are presented showing the detection of defects in PCB material. Measurements were performed on various kinds of typical defects in PCB materials (both Cu metal and non-metal epoxy). The obtained thermal image reveals area of defect in row of thick epoxy material and PCB.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.4
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• pp.813-818
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• 2018

In this paper, the assessment items were selected for water by drought, water quality by drought, and thermal diseases by heat wave. We described the selection background for these assessment items. and then we weighted the selected vulnerability assessment items. The vulnerability assessment procedures also describe the calculation methods applied in phases and the actual cases. The vulnerability assessment database was analyzed and a climate change vulnerability assessment system for heat waves and droughts using these vulnerability assessment procedures was designed.

• Journal of Environmental Science International
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• v.28 no.7
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• pp.617-627
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• 2019

This study investigated the relationship between heat-related illnesses obtained from healthcare big data and daily maximum temperature observed in seven metropolitan cities in summer during 2013~2015. We found a statistically significant positive correlation (r = 0.4~0.6) between daily maximum temperature and number of the heat-related patients from Pearson's correlation analyses. A time lag effect was not observed. Relative Risk (RR) analysis using the Generalized Additive Model (GAM) showed that the RR of heat-related illness increased with increasing threshold temperature (maximum RR = 1.21). A comparison of the RRs of the seven cities, showed that the values were significantly different by geographical location of the city and had different variations for different threshold temperatures. The RRs for elderly people were clearly higher than those for the all-age group. Especially, a maximum value of 1.83 was calculated at the threshold temperature of $35^{\circ}C$ in Seoul. In addition, relatively higher RRs were found for inland cities (Seoul, Gwangju, Daegu, and Daejeon), which had a high frequency of heat waves. These results demonstrate the significant risk of heat-related illness associated with increasing daily maximum temperature and the difference in adaptation ability to heat wave for each city, which could help improve the heat wave advisory and warning system.

• Journal of Industrial Convergence
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• v.18 no.6
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• pp.99-105
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• 2020

In general, heat-based treatments are preferred to form the most natural and elastic curls. Therefore, this study measured the degree of hair damage, which has an influence on hair, in relation to the heat formation of the rods used during perms using a scanning electron microscope (SEM). To examine the influence of the heat formation rods on permanent waves, this study measured the temperature transmitted from such rods. Then, a treatment was given after cutting the hair according to the round shape. According to observation with a SEM, hair breakage was found in the portion in direct contact with the heat, and the broken surface was smooth. According to the study results, it is anticipated that there should be many studies on the rods used during perms in the consideration of their structure and importance using materials that have the property of even heat transmission.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.25-26
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• 1996

In the standard theory of the large scale structure formation, matter accretes onto high density perturbations via gravitational instability. Collision less dark matter forms caustics around such structures, while collisional baryonic matter forms accretion shocks which then halt and heat the infalling gas. Here we discuss the characteristics. roles, and observational consequences of these accretion shocks.

• Proceedings of the KIEE Conference
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• 1997.07e
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• pp.1678-1680
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• 1997

The pulsed power with the high voltage and current can be used to the fields of high speed pulses of energy in different forms such as electric current and voltage, electron beam, ion beam, x-rays, gamma rays, heat, magnetics fields, sound and shock waves. This paper is directed mainly at electrical engineers working on production and practical application of high speed pulsed power with high voltage and current.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.8
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• pp.658-663
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• 1998

Ferrite plating enables were grown by ferrite by plating method in solution at low temperature(<10$0^{\circ}C$). This faciltates the fabrication of new ferrite thin film devices using non- heat-resistant materials(plastic, GaAs ect) as substrates. Combining the ferrite plating with sonochemistry, application of power ultrasonic waves to stimulate chemical reactions, the crystallinity and qualities of films were improved. Modifying the reactions cell and plating conditions further improved the film quality.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.4
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• pp.17-22
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• 2008

Including heat wave, Climate change caused 150,000 casualty in 2000 and heat waves are meteorological events that pose a serious threat to human health. A heat wave is defined as "a period of abnormally and uncomfortably hot and usually humid weather". There is a need for the prevention of health effects due to weather and climate extremes. This study intends to propose the necessity of Response System to correspond to extreme heat. And this research focused on Cooling Center manual of facility and maintenance for extreme heat disaster. It would be useful to be planned based on community and to be taken a role as an E.O.C.(Emergency Operating Center). As a conclusion elderly watching system and the requirements regional cooling center facility was proposed.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.6
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• pp.586-590
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• 2009

Poisson's ratio, one of elastic constants of elastic solids, has not attracted attention due to its narrow range and difficult measurement. Transverse wave velocity as well as longitudinal wave velocity should be measured for nondestructive measurement of Poisson's ratio. Rigid couplants for transverse wave is one of obstacle for scanning over specimen. In the present work, a novel measurement of Poisson's ratio distribution was applied. Immersion method was employed for the scanning over the specimen. Echo signals of normal beam longitudinal wave were collected, and transverse wave modes generated by mode conversion were identified. From transit time of longitudinal and transverse waves, Poisson's ratio was determined without the information of specimen thickness. Poisson's ratio distribution of the carbon steel weldment was mapped. Heat affected zone of the weldment was clearly distinguished from base and filler metals.

• Journal of Environmental Science International
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• v.16 no.12
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• pp.1439-1449
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• 2007

Heavy snowfall was occurred over the south-western part of the Korean Peninsula called as Honam Districts, on two days from 21 December 2005. The development mechanism of snowfall and its characteristics were analysed using observation and numerical data provided by Korea Meteorological Administration. In comparison with other years Arctic air mass developed and maintained during all December 2005 due to active planetary waves with three branches. And jet streams at lower and higher levels make easy development of snow convection cells. Especially thermal low induced by mesoscale heat and dynamic sources, also help the developments of convection cells in strong ascension. The understanding the relation between synoptic and mesoscale circumstance, therefore, is also important to predict the heavy snowfall and to prevent the disaster.