• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.2
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• pp.251-259
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• 1999

A computer simulation was conducted for heat and momentum transfer in a roller kiln. Time-averaged Navier-Stokes equation conjugated with energy balance equation was numerically solved to predict the temperature distribution and fluid flow field in the roller kiln. A computer simulation was performed for a roller kiln for three cases. Firstly, when there are no ceramic materials in the roller kiln, the effect of natural convection was studied on the temperature distribution and fluid flow field. From the result, it was observed that air takes the heat of wall away from the roller kiln by natural convection and the heat was not transferred effectively. Secondly, with ceramic materials temperature difference of ceramic material from the borrom to the top of a ceramic material was about 255K in 5th zone and this is because the heat is transferred from the surface of a ceramic material to flowing air with relatively low temperature. Finally, we considered effect of radiation heat transfer. Temperature difference of ceramic material in 5th zone was about 300 K, due to radiation heat transfer on the ceramic material surfaces.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.12
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• pp.1054-1061
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• 2016

Development of an accurate infrared signature (IR) measurement system is expected to contribute in the development of low observable technology and the spectroscopic analysis of electromagnetic radiation. Application of a spectroradiometer (SR) allows for the measurement of detailed infrared signature from the exhaust plume due to its own heat source. Establishment of a measurement system using a micro-turbo engine is intended to simulate the modelling of the aircraft plume. The engine was installed on a test stand to measure the engine performance. The IR signature was measured by placing the SR perpendicular to the axis line of the exhaust plume. Reference data from the blackbody were also measured to calibrate the raw data, and the infrared signature of the background was also measured for comparison with that of the plume. The calibrated spectral radiance was obtained through the data reduction process and the results were analyzed in specific bands. The experiments revealed that the measurement system established here showed sufficient performance for further comprehensive analysis.

• Journal of the Korean Geosynthetics Society
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• v.18 no.4
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• pp.53-61
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• 2019

It is well known there are a lot of undeveloped energy resource in the Arctic circle. As global warming enables the use of Arctic sea routes, the interest in Arctic resource development is increasing. Recently, polar neighbors and developed countries are actively promoting construction project in Arctic circle. However, the issue of environmental pollution caused by Arctic resource development has been raised. Today, environmental issues have a significant impact on the success of the project as well as on the costs of Arctic development projects. Therefore, it is necessary to secure a technology related to energy resource development and transportation for the Arctic resource project. In addition, the establishment of strategy for environmental impact assessment (EIA) is important. This paper shows the characteristics and procedures of EIA for developing Arctic resources, and reviews how to construct the systematically management of the necessary information. This system consists of a database required for environmental impact assessment and its application. The system is expected to be utilized for strategic development projects in the Arctic.

• Journal of Sasang Constitutional Medicine
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• v.29 no.3
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• pp.262-270
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• 2017

Objectives The purpose of this study was to investigate the difference in color perception among Sasang Constitution in "The dress" which has been arousing controversy whether its color is blue/black or white/gold. Methods 85 participants classified as Sasang Constitution were asked to answer three questions about "The dress". They were asked firstly the overall colors of the dress, secondly the colors of the specific parts of it, thirdly color ranges they perceived as gold, white, blue, black, respectively. These process were run twice. Results and Conclusions The overall colors of the dress were perceived as blue/black more than white/gold, regardless of Sasang Constitution. And also the ratio between blue/black and white/gold were not significantly different among Sasang Constitution. But when a specific part(spot ii) shown, Soyangin perceived its color as blue more than Taeeumin in the first process. In the case of color range, Soyangin perceived range of black wider than Taeeumin in the second process.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.12
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• pp.801-807
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• 2016

This paper aims to compare and study the cooling performance of a battery system in accordance with the inlet and outlet geometry of the air passage in an EV. The arrangement and the heat source of the battery module were fixed, and the inlet/outlet area and its geometry were varied with the analysis of the cooling performance. The results of this study provide suggestions for the air flow stream line inside of a battery, the velocity field, and the temperature distributions. It was confirmed that the volume flow rate of air should be over $400m^3/h$, in order to satisfy conditions under $50^{\circ}C$, which is the limit condition for stable operation. It was also revealed that the diffuser outlet geometry can improve the cooling performance of battery system.

• Anxiety and mood
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• v.12 no.2
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• pp.97-102
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• 2016

Objective : This study aimed to quantify the degrees of insomnia, depression and anxiety felt by employees, and to understand which components of insomnia affect depression and anxiety. Methods : One thousand employees who had medical checkups from January to December 2014 in the Workplace Mental Health Institute of Kangbuk Samsung Medical Center were selected randomly. Sleep quality, depression, and anxiety were rated using the Pittsburgh Sleep Quality Index (PSQI), the Center for Epidemiologic Studies Depression scale (CES-D), and the Beck Anxiety Inventory (BAI), respectively. Good and poor sleepers were divided into two groups according to their total PSQI score : ${\leq}5$ for good sleepers or >5 for poor sleepers. Results : Of 998 employees, 742 (74.35%) had PSQI total scores below 5, and 256 (25.65%) had scores over 5. Multivariate linear regression analysis using the 7 components of PSQI versus BAI, and CES-D scores revealed that subjective sleep quality, daytime dysfunction, sleep disturbance, sleep latency and sleep duration components were significantly associated with both BAI and CES-D. Conclusion : Among the components of insomnia, subjective sleep quality and daytime dysfunction were most strongly associated with depression and anxiety.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4381-4387
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• 2015

Ship hull is a compound curved shape and most of shipyards have been using gas heating method for the surface forming of steel plate. This traditional forming process have problems such as difficulties in heat input control and poor working conditions due to loud noise and air contamination. Recently, researches on automatic hull forming system have been conducted using high frequency induction heating method which have good control ability and favorable working environment. In this study, the induction heating simulation system for curved surface forming of steel plate was developed and induction heating experiments were performed. Based on the results of this study, efficient induction heating coil design and optimal heating conditions for the automatic hull forming system can be obtained.

• The Journal of the Korea Contents Association
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• v.15 no.7
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• pp.216-227
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• 2015

The purpose of this study is to investigate the moderating effect of interpersonal relationship skills in adapting military life and stress in the army. For this purpose, 453 soldiers in Chungnam and Daejeon were surveyed. First, the main result of this study is the difference in interpersonal skills and group life adjustment in accordance with the rank and class of the soldiers. Second, too much stress can cause difficulty to adapt military life and interpersonal skills. Also high interpersonal skills can help to adjust well to military life. Third, according to the survey, it was confirmed that the openness in the sub-factors of military life and military life stress was effective. This study suggests that it is important to help control the stress of military life to improve the ability of the openness of interpersonal skills in order to increase the adaptability military life.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.2
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• pp.99-112
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• 2015

In this study, laboratory test equipment was designed and installed to evaluate the thermal behavior of bentonite, which is used as a buffer in high-level waste disposal systems. The thermal analysis was conducted to verify the test results using ABAQUS, a finite element analysis code. In view of the seasonal changes seen during the test, the thermal behavior of bentonite with a temperature of outside air was evaluated. Of the cases examined, the results of the analysis model using stainless steel (Case 3) approximates to the test results, showing an error of about 1℃. The results of the thermal analysis into seasonal temperature distributions are consistent with trends seen in lab-test results. These analyses show that the effects of the thermal conductivity of the material surrounding the buffer and outside air temperature, are very important factors in the thermal behavior of bentonite. In the future, it is expected that a moisture saturation test of a bentonite buffer containing a heat source will be carried out. Therefore, the development of a numerical analysis model is required for the prediction and verification of the laboratory test results.

• Journal of the Society of Disaster Information
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• v.16 no.2
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• pp.383-391
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• 2020

Purpose: To identify internal self ignition and ignition caused by external flames in energy storage rooms, and to analyze the difference between ignition due to overheating and ignition caused by external heat sources. Method: membrane melting point measurement, battery external hydrothermal experiment, battery overcharge experiment, comparative analysis of electrode plate during combustion by overcharge and external heat, overcharge combustion characteristics, external hydrothermal fire combustion characteristics, 3.4 (electrode plate comparison) / 3.5 (overcharge) /3.6 (external sequence) analysis experiment. Result: Since the temperature difference was very different depending on the position of the sensor until the fire occurred, it is judged that two temperature sensors per module are not enough to prevent the fire through temperature control in advance. Conclusion: The short circuit acts as an ignition source and ignites the mixed gas, causing a gas explosion. The electrode breaks finely due to the explosion pressure, and the powder-like lithium oxide is sparked like a firecracker by the flame reaction.