• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2011년도 춘계학술논문발표회 논문집
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• pp.28-31
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• 2011

최근 산불과 같은 불티로 인한 2차화재의 발생 비율이 높아지고 있는 추세이다. 그러나 이를 불티로 인한 화재 성상을 CFD로 해석하기 위해서는 불티에 가해지는 유체력을 평가하여야 연소모델을 적용할 수 있다. 따라서 본 연구에서는 기존 풍속에 의한 불티 확산실험의 결과를 토대로 FDS에 적용 할 수 있는 연소모델을 구축하고 위하여 수리 모델 및 수치 해법에 대해 정리하고 이를 FDS 연소모델에 적용을 실시하였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1997년도 추계학술대회논문집
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• pp.45-48
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• 1997

The kinematically admissible velocity field is developed for the eccentric extrusion of circular shaped products. The curving of product in extrusion is caused by the difference of the linearly distributed longitudinal velocity on the cross-section of the workpiece at the dies exit. The results of the eccentric extrusion by upper bound analysis show that the curvature of product increases with the increase in eccentricity of gravity center of the cross-section of workpiece at dies entrance from that of the corss-section at the dies exit end. By the DEFORMTM-3D analysis, the curving of circular shaped product in extrusion is changed by the eccentricity, die land length and the die length. The result of the analysis by DEFORMTM-3D software shows that the curvature of circular shaped product increases with the eccentricity. The two analysis and one experiment show the curving phenomenon in eccentric extrusion process.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1997년도 추계학술대회논문집
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• pp.49-52
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• 1997

The kinematically admissible velocity field is developed for the analysis of the curving of an eccentric extrusion. The curving of product in extrusion is caused by the difference of the linearly distributed longitudinal velocity on the cross-section of the workpiece at the dies exit. The result of the analysis show that the curvature of product increases with the increase in eccentricity of gravity center of the cross-section of the workpiece at the die entrance from that of the cross-section at the die exit. It also increase with the die land dimension. By the DEFORMTM-3D analysis, the curving of T-shaped product in extrusion is changed by the eccentricity, die land length and the friction constant. The result of the analysis by DEFORMTM-3D software shows that the curvature of circular shaped product increases with the eccentricity. The two analysis and one experiment show the curving phenomenon in eccentric extrusion process.

• 소성∙가공
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• 제8권2호
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• pp.143-151
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• 1999

The twisting and extrusion process of the product with trapezoidal helical fin from the round billet is developed by the upper bound analysis. The twisting of extruded product is caused by the twisted die surface connecting the die entrance section and the die exit section linearly. In the analysis, the rotational velocity in angular direction is assumed by the multiplication of radial distance and angular velocity. The angular velocity is increased linearly by axial distance from the die entrance. The increase rate of angular velocity is determined by the minimization of plastic work. The results of the analysis show that the angular velocity of the extruded product increases with the die twisting angle, the reduction of area, and decreases with the die length, the friction condition.

• 한국금형공학회:학술대회논문집
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• 한국금형공학회 2008년도 하계 학술대회
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• pp.27-30
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• 2008

It was investigated that two rods of aluminium can be welded by hot extru-welding method with extru-welding dies, and that the extru-welding on the welding surface were analyzed by computer simulation according to the steped shapes of welding dies. It was known by computer simulation that welding pressure on the welding section of rods welded using extru-welding dies and that the welding pressure on the welding section of rods using extru-welding dies is lowerer than the welding pressure of rods using stepped welding dies. And it was known by experiments that two rods of aluminium can be welded on the end sections by hot extru-welding method using fan-shaped stepped welding dies without relative rotational movement of contacted aluminium rods needed for the purpose of friction heating and pressure.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2012년도 추계총회 및 학술대회 논문집
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• pp.196-198
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• 2012

TiN 박막을 자전거용 서스펜션 프레임의 재질로 사용되는 고비강도 경량 합금에 적용하기 위해 Arc ion plating 방식으로 코팅하고 기계적 특성을 분석하였다. TiN 박막의 코팅 특성 평가는 XRD, 박막 경도, 마찰 계수, 밀착력을 측정하였고 피로시험을 실시하였다. 박막의 경도는 약 19 GPa로 측정되었고, 마찰 계수는 약 0.4로써 박막의 코팅 전(마찰계수 0.8)보다 낮아졌다. 밀착력은 약 13.9 N로 나타났으며, 피로 시험은 약 30,000회의 수직 하중 실험에도 박막의 가시적 크랙과 파손이 관찰되지 않았다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.3133-3135
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• 2000

RFID (Radio Frequency Identification) system is applied to identify, locate and track people, cars, animals. Passive RFID system consists of reader and tag. The reader transmits a carrier signal, receives the backscattering signal, performs data processing. The tag is energized by carrier signal that is transmitted from the reader and the information stored in the tag is transmitted back to the reader. In this paper, the design and analysis of the 125kHz RFID system is presented and is confirmed through experiment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.3145-3147
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• 2000

A passive RFID system consists of reader and tag. Reader is required the filter to modulate the data from backscattering signal which is transmitted by tag. The filter in the reader consists of envelope detector, amplifier, filter, and pulse shaping circuit, In this paper, design and analysis of filter in the RFID system which is operated at l3.56MHz carrier and 70KHz backscattering signal frequency is presented and is confirmed by simulation using Pspice.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3256-3258
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• 1999

Recently contactless ID system has emerged as new ID industry. It's called RF-ID. RF-ID is divided into active RF-ID and passive RF-ID. The passive RF-ID operates without battery and so has no limitation in its operating range and life time. But it needs the RF-OC conversion circuit. It also can be applied to batteryless sensor for many application. This paper presents the study of the RF-OC conversion circuit for batteryless system in high frequency and confirms it by simulation and experiment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3259-3261
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• 1999

A passive RF transponder incorporating a non volatile memory element is powered by inductive coupling to a proximately located RF reader and communicates with reader. In this study, we designed and analyzed the passive RF transponder which is operated at 134kHz.