• Journal of the Korean Society of Mechanical Technology
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• v.20 no.6
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• pp.751-756
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• 2018

A study on the weight reduction of a motor shaft in electric vehicle by using optimum design technique was carried out. The structural analysis of a motor shaft was performed by using ANSYS to investigate the structural safety. We also used HEEDS to find the optimal hollow shaft thickness. When the material of the hollow shaft is changed to SCM822H by using ANSYS 14.5 and HEEDS MDO, the weight could be reduced by about 53 % compared to the conventional solid one. From this study, the optimized dimensions of a hollow shaft were determined for light weight design.

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.178.2-178.2
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• 2001

• Journal of Chest Surgery
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• v.49 no.6
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• pp.478-480
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• 2016

Spontaneous perforation of the esophagus after forceful vomiting is known as Boerhaave syndrome, a rare and life-threatening condition associated with a high rate of mortality. The management of Boerhaave syndrome is challenging, especially when diagnosed late. Herein, we report the successful management of late-diagnosed Boerhaave syndrome with T-tube drainage in a 55-year-old man. The patient was transferred to our institution 8 days after the onset of symptoms, successfully managed by placing a T-tube, and was discharged on postoperative day 46 without complications.

• 한국연소학회:학술대회논문집
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• 2007.05a
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• pp.176-183
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• 2007

An experimental study was performed to investigate the effects of mixing quality, inlet pressure, nozzle diameter on CO emission and radiation characteristics in porous ceramic fiber radiant burners. Observations of combustion characteristics occurring inside the burner system which was insulated fiber mat, were investigated by measuring temperature, CO emission and radiation characteristics. Combustion was achieved at the firing rate of $88{\sim}99$ kcal/hr, inlet pressure of $100{\sim}250$mm$H_2O$. CO emissions were found to be strongly dependent on the operating conditions. There was a tendency that CO concentration increased as the firing rate increases. The reason for rise of CO concentration is that it becomes the relatively rich condition. The fiber burner exhibit significant both spectral intensity peaks in the bands at 2.5${\mu}m$ and 4.0${\mu}m$ relatively, There is a small difference in the variable mixing tube. However spectral intensity increased with the firing rate.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.65.2-65.2
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• 2010

We present a result of $^{13}CO$(1-0) survey toward the Outer Galactic Plane using the multi-beam receiver system recently installed on the 14 m telescope at Taeduk Radio Astronomy Observatory(TRAO). Our first target region is from $l=108^{\circ}$ to $113^{\circ}$ and $b=-1^{\circ}$ to $+1^{\circ}$, and some extended regions are included where emission is still arising. All data are on 50" grid. Velocity resolution is 0.63 km/sec, and the total velocity range is from -150 km/sec to 100 km/sec. A total of 40,000 spectra were obtained. The rms noise is about 0.2 K per channel for unsmoothed raw data. We will present a few initial results of the survey database.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.32.2-32.2
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• 2010

The Korean Solar Radio Burst Locator (KSRBL) is a single dish radio spectrograph, which is designed to record the spectra of microwave (0.5 - 18 GHz) bursts with 1 MHz spectral resolution and 1 s time cadence, and locate their positions on the solar disk within 2 arcmin. It was installed at KASI in 2009 August, and operational thereafter. The antenna pointing coefficients were initially determined during the installation and refined later using a series of antenna pointing calibrations. The filter to prevent the radio frequency interference around 2 GHz was designed and is to be installed. After the installation, the full frequency coverage will be recovered from the temporarily restricted frequency coverage (5 - 14 GHz). Also an effort to solve a couple of minor problems for the full performance of the system is in progress.

• The Journal of the Acoustical Society of Korea
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• v.24 no.2E
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• pp.46-53
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• 2005

Agency for Defense Development (ADD) developed the Submarine Acoustic Information Management System (SAIMS Version 1.0) capable of interfacing some submarine sensors in operation and predicting detection environments for sonars. The major design concepts are as follows: 1) A proper acoustic model is examined and optimized to cover wide spectra of frequency ranges for both active and passive sonars. 2) Interfacing the submarine sensors to an electric navigation chart, the system attempts to maximize the applicability of the information produced. 3) The state-of-the-art database in large area is built and managed on the system. 4) An algorithm, which is able to estimate a full sound speed profile from the limited oceanographic data, is developed and employed on the system. This paper briefly describes design concepts and algorithms embedded in the SAIMS. The applicability of the SAIMS was verified through three sea experiments in October 2003-February 2004.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.82.1-82.1
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• 2011

Korea Astronomy and Space Science Institute (KASI) operates 2 solar radio observing facilities, e-CALLISTO (Earthwide network of Compound Astronomical Low-cost Low-frequency Instrument for Transportable Observatory) station and Korean Solar Radio Burst Locator (KSRBL). Although e-CALLISTO tracking system improvement.is underway, at least 6 new events were observed in this year. Software development for KSRBL is in progress. The antenna calibration software was updated and flux calibration software was developed. Also the automatic daily overview spectrum monitoring system is now operational. We found solutions to several problems including spurious data and FPGA board communication. However, a few minor unsolved hardware problems still persist. Meanwhile, at least 6 new events were observed by KSRBL in this year, and a comparative study with HXR is currently underway.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12C
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• pp.1162-1166
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• 2005

A new low dimensional feature representation technique is presented in this paper. Linear discriminant analysis is a popular feature extraction method. However, in the case of high dimensional data, the computational difficulty and the small sample size problem are often encountered. In order to solve these problems, we propose two dimensional direct LDA algorithm, which directly extracts the image scatter matrix from 2D image and uses Direct LDA algorithm for face recognition. The ORL face database is used to evaluate the performance of the proposed method. The experimental results indicate that the performance of the proposed method is superior to DLDA.

• Macromolecular Research
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• v.12 no.3
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• pp.269-275
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• 2004

To graft N-isopropylacrylamide (NIPAAm) onto alginate, varying dosages of ${\gamma}$-rays were irradiated onto alginate films in deionized water and methanol media, which are non-solvents of alginate. We investigated the hydrogels graft ratio, mechanical strength, swelling kinetics and ratio, and behavior with respect to drug release. The graft yield of NIPAAm increased upon increasing the irradiation dose. The use of the aqueous solution increased the graft yield relative to that obtained in methanol. The mechanical strength of the grafted hydrogels increased after grafting with NIPAAm. In a study of the swelling kinetics, we found that all hydrogels reached an equilibrium swollen state within 3 h. The equilibrium swelling ratio of the hydrogels decreased upon increasing the irradiation dose. The swelling ratio of the hydrogels decreased dramatically between 30 and 35$^{\circ}C$ because phase separation of NIPAAm occurred at 32$^{\circ}C$. The swelling process, with respect to the temperature change, was repeatable. An NIPAAm-grafted alginate containing a drug sustained its release rate until 3 h after an initial high drug release caused by a burst effect.