• Title/Summary/Keyword: single-pass

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Behaviors of the interface cracks during an Al-Fe dissimilar joining (Al-Fe 이종재료 접합 계면에서의 크랙 거동)

  • Gang Nam-Hyeon;Kim Cheol-Hui;Kim Jun-Gi;Lee Chang-U
    • Proceedings of the KWS Conference
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    • 2006.05a
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    • pp.59-61
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    • 2006
  • The $CO_2$ laser cladding was conducted on an AC2B alloy with feeding Fe-based powders. A powder feeding rate (PFR) and a travel velocity were related with the cracks adjacent to the Fe/Al interface. Preheating temperature was varied to study the interface crack. Preheating to $250^{\circ}C$ during the laser cladding suppressed the interface crack ratio (ICR). The ICR was limited for the single pass clad and the reciprocating test for the slide wear was conducted on an overlay cladding experiment. Comparing with no overlap overlay, the overlay clad with 50% overlap showed better wear resistance.

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A DEVELOPMENT OF MATHEMATICAL MODELS FOR PREDICTION OF OPTIMAL WELD BEAD GEOMETRY FOR GMA WELDING (GMA 용접에 최적의 용접비드 형상을 예측하기 위한 수학적 모델 개발)

  • 김일수
    • Journal of Welding and Joining
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    • v.15 no.3
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    • pp.118-127
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    • 1997
  • With the trend towards welding automation and robotization, mathematical models for studying the influence of various variables on the weld bead geometry in gas metal arc (GMA) welding process are required. Partial penetration, single-pass bead-on-plate welds using the GMA welding process were fabricated in 12mm mild steel plates employed four different process variables. Experimental results has been designed to investigate the analytical and empirical formulae, and develop mathematical equations for understanding the relationship between process variables and weld bead geometry. The relationships can be usefully employed not only for open loop process control, but also for adaptive control provided that dynamic sensing of process output is performed.

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LAND COVER CLASSIFICATION BY USING SAR COHERENCE IMAGES

  • Yoon, Bo-Yeol;Kim, Youn-Soo
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.76-79
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    • 2008
  • This study presents the use of multi-temporal JERS-1 SAR images to the land cover classification. So far, land cover classified by high resolution aerial photo and field survey and so on. The study site was located in Non-san area. This study developed on multi-temporal land cover status monitoring and coherence information mapping can be processing by L band SAR image. From July, 1997 to October, 1998 JERS SAR images (9 scenes) coherence values are analyzed and then classified land cover. This technique which forms the basis of what is called SAR Interferometry or InSAR for short has also been employed in spaceborne systems. In such systems the separation of the antennas, called the baseline is obtained by utilizing a single antenna in a repeat pass

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A design of high speed and low power 16bit-ELM adder using variable-sized cell (가변 크기 셀을 이용한 저전력 고속 16비트 ELM 가산기 설계)

  • 류범선;조태원
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.35C no.8
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    • pp.33-41
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    • 1998
  • We have designed a high speed and low power 16bit-ELM adder with variable-sized cells uitlizing the fact that the logic depth of lower bit position is less than that of the higher bit position int he conventional ELM architecture. As a result of HSPICE simulation with 0.8.mu.m single-poly double-metal LG CMOS process parameter, out 16bit-ELM adder with variable-sized cells shows the reduction of power-delay-product, which is less than that of the conventional 16bit-ELM adder with reference-sized cells by 19.3%. We optimized the desin with various logic styles including static CMOs, pass-transistor logic and Wang's XOR/XNOR gate. Maximum delay path of an ELM adder depends on the implementation method of S cells and their logic style.

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Fiber Raman Laser and its Application to Measurement of Optical Fiber Dispersion Characteristics (광섬유 라만 레이저와 광섬유의 분산 특성 측정에의 응용)

  • 정영철;신상영
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.21 no.1
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    • pp.38-44
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    • 1984
  • Subnanosecond optical pulses with 0.8-1.Bum wavelength are generated by experimentally realizing a single pass fiber Raman laser. This fiber Raman laser is pumped by a mode-locked and Q-switched Nd-YAG laser. Two wave sum frequency phenomenon is also obsenred in the course of the experimental work. The fiber Raman laser is then used to measure dispersion characteristics of a sin\ulcorner mode fiber in the long-wavelength lesion.

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A Study on the Charactdristics of CNC Deep Hole Maching for Marine Part Materials with the Sintered Carbide Gun Drill (초경합금 Gun Drill에 의한 박용 부품 재료의 CNC 심공가공 특성에 관한 연구)

  • 전태옥;심성보
    • Journal of Advanced Marine Engineering and Technology
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    • v.18 no.2
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    • pp.64-74
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    • 1994
  • The gundrill is capable of machining for having large length to diameter ratio in single pass. The techniques of gundrill and gun boring began developing in the late 18th century with the need for more accurate bores in rifle, cannon, machinery part and marine part etc. The main feature of the gun drilling provides a stabilizing cutting force resultant necessary for self guidance of the drill head. A study of the accuracy and surface finish of holes produced would reveal quite useful information regarding the process. The thesis deals with the experimental results obtained during gun drilling on marine part materials for different machining conditions.

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Performance Characteristics of Hydrogen Peroxide Mono Propellant PDE (Pulse Detonation Engine) (과산화수소 단일 추진제 PDE의 성능 특성에 관한 수치적 연구)

  • Cho, Heung-Sik;Jeung, In-Seuck;Choi, Jeong-Yeol
    • 한국연소학회:학술대회논문집
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    • 2003.12a
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    • pp.153-157
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    • 2003
  • Supersonic and hypersonic aircrafts must pass wide range of speed to reach high speed region. But for existing engines the most efficient operating speed ranges are decided according to their flying speed, so an engine which mixes several engines like TRJ (Turbo Ramjet) and ARJ (Air Turbo Ramjet) has been planed. This mixed type engine has inefficiency that more than two engines must be installed simultaneously, but the pulse detonation engine (PDE) that uses detonation wave has a strong point that it can operate in all speed range with single engine. This paper deals with the simulation of the pulse detonation engine which uses hydrogen peroxide $(H_2O_2)$ mono propellant. Hydrogen peroxide is low-cost propellant, and it is reacted without oxidizer. Comparison between $H_2-O_2$ mixture with $H_2O_2$ mono propellant about thrust, pressure, temperature and velocity shows that $H_2O_2$ is a very useful propellant.

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EXTRACTION OF LAND COVER INFORMATION BY USING SAR COHERENCE IMAGES

  • Yoon, Bo-Yeol;Kim, Youn-Soo
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.475-478
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    • 2007
  • This study presents the use of multi-temporal JERS-1 SAR images to extract the land cover information and possibility. So far, land cover information extracted by high resolution aerial photo and field survey. The study site was located in Non-san area. This study developed on multi-temporal land cover status monitoring and coherence information mapping can be processing by L band SAR image. From July, 1997 to October, 1998 JERS SAR images (9 scenes) coherence values are analyzed and then extracted land cover information factors, so on. This technique which forms the basis of what is called SAR Interferometry or InSAR for short has also been employed in spaceborne systems. In such systems the separation of the antennas, called the baseline is obtained by utilizing a single antenna in a repeat pass

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Tissue-specific Expressed Sequence Tags from the Olive flounder, Paralichthys olivaceus

  • Kim, Young-Ok;Lee, Jeong-Ho;Kim, Kyung-Kil;Lee, Jong-yun
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2002.10a
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    • pp.181-182
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    • 2002
  • Expressed sequence tags (ESTs) are generated by single-pass DNA sequencing of clones obtained from cDNA libraries and are powerful tool in the genetic characterization of organisms, owing in large part to the speed and affordability of generating these sequences. Comparison of sequences obtained with those available in public sequence databases allows putative identification of many genes. (omitted)

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Simulation of square-to-oval single pass rolling using a computationally effective finite and slab element method

  • 이상매;김낙수
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1991.04a
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    • pp.237-242
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    • 1991
  • Shape rolling has been studied experimentally by many researchers. As large numbers of process variables are involved and the material flow is difficult to analyze in shape rolling, the use of numerical techniques as an engineering tool becomes extremely attractive. The first numerical approach to the three-dimensional plastic deformation of rolling was to investigate side spread in flat rolling. Oh and Kobayashi conducted a pioneering study in this field by applying an extremum principle for rigid, perfectlyplastic materials combined with the numerical computation. Since then, several other researchers have used three-dimensional finite element method for analysing spread in rolling . In this investigation of shaperolling al the computer simulations of shape rolling were conducted using TASKS. To verify the predictive capabilities of TASKS the first example chosen was square-to-round shape rolling