• Title/Summary/Keyword: 상호관통

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Study of Hypervelocity Penetration Characteristics of Segmented Tungsten Penetrator (분절형 텅스텐 관통자의 초고속 관통특성에 관한 연구)

  • Jo, Jong Hyun;Lee, Young Shin;Kim, Jae Hoon;Bae, Yong Woon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.8
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    • pp.953-960
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    • 2013
  • This study aimed to investigate the penetration characteristics of a segmented penetrator with normal and inclined angles. The length to diameter ratio (L/D) of the segmented penetrator was varied as 1.0, 0.5, and 0.25. Moreover, impact velocities of 1.5, 2.0, and 2.5 km/s and inclination angles of $15^{\circ}$, $30^{\circ}$, and $45^{\circ}$ were successively applied. The AUTODYN-3D code was used to simulate the penetration performance of the segmented penetrator. The results show that the penetration performance of the segmented penetrator with steel plates was obviously higher than that of the corresponding continuous penetrator with steel plates. The outstanding penetration performance of the segmented penetrator can be observed when the impact velocity was 2.0 km/s and L/D = 1. In this case, the penetration performance of the segmented penetrator was 7% higher than that of the corresponding continuous penetrator. This trend was attributable to the interaction between the reactive plate and the projectile. The extent of the interaction relies on the relative velocities of the plate and projectiles, inclination angle, and number of segmented penetrators. It was proven that the penetration performance of the segmented penetrator can be improved by increasing the impact velocity, number of segmented penetrators between segments, and penetrator length.

해안대수층에서 지하수-지표수 상호작용

  • 김구영;이철우;김용제;김태희;우남칠
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2004.04a
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    • pp.366-369
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    • 2004
  • 조석의 효과가 대수층에 미치는 해안대수층에서 지하수-기표수 상호작용에 관한 모사를 위해 수치모델링을 이용하였다 모사에 사용한 모델은 하천경계와 해안경계가 서로 직교하며 하천은 대수층을 부분 관통하고 있다. 해안경계와 하천경계에 의한 동시영향을 함께 모사한 결과, 해안경계에 의한 효과는 일정한 범위까지만 나타났으나, 하천경계에 의한 영향은 시간의 증가에 따라 영향범위가 넓어졌다. 하천경계와 해안경계조건이 만나는 부근에서는 해안경계에 의한 지하수위의 반복적인 상승과 하강으로 인해 두 경계조건에 의한 지하수위가 상호 상승작용을 일으키기도 하고 상호 상쇄되어 지하수위의 변화가 없는 엉역이 나타나기도 한다. 따라서 이러한 하천과 해안경계조건이 상호 교차하는 주변 대수층에서의 수위를 측정하여 해안대수층에서의 수리상수를 추정하면 수리확산계수를 과대 혹은 과소평가하는 오류를 범할 수 있으므로 주의를 요한다.

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Modeling of Metal Penetration Rate by a High Power Continuous Wave Laser (고출력 연속발진 레이저에 의한 금속 관통율 모델링)

  • Shin, Wan-Soon;Koh, Hae-Seog;Park, Byung-Suh;Kang, Eung-Cheol
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.5
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    • pp.705-711
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    • 2012
  • The purpose of this study is to develop the model to estimate the penetration rate of metal under a high power continuous wave laser irradiation. To estimate it, an empirical modeling is more practical when the penetration phenomena of metal by laser irradiation is too complex to be analyzed by the numerical simulation. When several methods published earlier were applied to our results, we found out that their methods were not appropriate as the model. Therefore, we suggested the new empirical method considering effective intensity as a key variable. As a result, we confirmed that the new method was effective to model the penetration rate of SUS304 metal and expected that it could be available to other metals.

A Study on the Postmodern Identity in Madonna Costume -Focusing on the intertextuality- (마돈나 의상에 나타난 포스트모던 정체성없음)

  • 김주영;양숙희
    • Journal of the Korean Society of Costume
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    • v.51 no.8
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    • pp.123-139
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    • 2001
  • 본고는 공간, 시간, 계급, 종교 등 하위문화 텍스트의 병행인용 즉 상호텍스트성(intertextuality)을 통해, 20세기 대중 문화의 상징 마돈나 뮤직 비디오와 공연 등의 인체, 의상, 이미지 등에 나타난 포스트모던 정체성을 연구함으로써, 현대 미디어 문화를 관통하는 주체적 여성 정체성과 미적 주관성을 이해하고자한다. 첫째, 상호공간텍스트성 복식은 스패니쉬룩. 태국룩. 게이샤룩, 테크노펑크룩, 테크노 카우걸룩 등의 동서양의 지리적 소외감을 통해 비권위적 다양한 시선을 제시함으로써, 다국적 자본주의와 함께 확장된 미적 체험을 하게 한다.; 둘째, 상호시간텍스트성 복식은 중세 엠파이어 드레스, 18세기 로코코시대의 robe'a la francaise, 미래적 제 3의 종 룩 등 동시적 몽환적 이미지를 통해 유희적 유토피아를 지향하였다.; 셋째, 상호계급텍스트성 복식은 그라피티룩, 펑크룩, 키치룩, 먼로 룩, 보깅(voguing), 에비타 룩 등 상하류층, 하위문화, 빈부, 권력의 유무를 병행인용하여, 좋은/나쁜 취향, 창녀/성녀 이분법을 해체하고 반부르조아적 저항과 물질주의를 찬양하는 탈계급적, 양면적 정체성을 구축하였다. ; 넷째, 상호종교텍스트성 복식은 상징적 가부장인 카톨릭교 텍스트를 인용하여 펑키크리스찬 룩, 에로틱 크리스찬 룩 등의 선/악, 신성성/관능성, 미추, 정숙성/비정숙성의 이분법, 비장미를 해체함으로써 예술의 자율성, 무의식이 강조된 쾌락주의적, 반권위주의적 정체성을 주장한다. 섹슈얼리티에 있어, 시선, 권력, 쾌락의 주체가 됨으로써, 미적 범주에 있어 선악, 미추, 정숙성과 비정숙성의 이분법을 해체함으로써, 유동적 자아를 구성한 마돈나 의상의 포스트모던 정체성은 여성에게 확대된 가능성을 제공하며 내부로부터 해체된 열린 복식을 지향한다.

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Analysis of Fluid-Structure Interaction by High Velocity Impact for Liquid Filled Cylindrical Container (고속충돌에 의한 원통형 액체 용기의 유체-구조 연성해석)

  • Bae, Hongsu;Woo, Kyeongsik;Kim, In-Gul;Kim, Jong-Heon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.2
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    • pp.108-115
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    • 2016
  • In this paper, fluid-structure of interaction behavior of a fluid-filled cylindrical polymer container impacted by a high speed spherical projectile was studied using ALE(Arbitrary Lagrangian Eulerian) method. The hydrodynamic ram phenomenon occurred by the impact projectile penetrating through the container was investigated by examining time histories of projectile velocity and fluid pressure and density. The analysis results were agreed reasonably well compared to those by experiments.

PCB Integrated Pick-up Coil Structure with High Mutual Inductance for Current Measurement of GaN Devices (GaN 소자의 전류 검출을 위한 높은 상호 인덕턴스를 가지는 PCB 내장형 Pick-up Coil)

  • Kim, Kyeong-Mo;Cha, Hwa-Rang;Yang, Si-Seok;Kim, Rae-Young
    • Proceedings of the KIPE Conference
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    • 2019.11a
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    • pp.90-92
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    • 2019
  • 본 논문은 GaN 디바이스를 사용하는 전력변환장치에서 Pick-up coil을 PCB 패턴으로 구현하여 전류를 측정하는 기법에 관하여 제안한다. 기존에 사용되는 PCB 패턴 코일 구조의 경우 PCB 이중층만 구성하여 관통 홀이나 추가공정이 필요함에 비해 본 논문에서 제안한 PCB 패턴 코일 구조의 경우 다층기판을 사용하여 코일을 구성함으로서 기존의 패턴에 비해 높은 상호 인덕턴스 값을 가지게 되고, 코일의 출력 전압값이 높아져 더 높은 감도를 가지게 된다. 또한 PCB 외부의 추가적인 공정 작업이 없이 구성이 되었다. 전류 측정은 코일 뒷단에 적분기를 통합하여 구성하였으며, 시뮬레이션을 통해 전류 측정 성능을 검증한다.

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Effects of Heat Treatment Conditions on the Interfacial Reactions and Crack Propagation Behaviors in Electroless Ni/electroplated Cr Coatings (열처리 조건에 따른 무전해 Ni/전해 Cr 이중도금의 계면반응 및 균열성장거동 분석)

  • Son, Kirak;Choi, Myung-Hee;Lee, Kyu Hawn;Byon, Eungsun;Rhee, Byong-Ho;Park, Young-Bae
    • Journal of the Microelectronics and Packaging Society
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    • v.23 no.3
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    • pp.69-75
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    • 2016
  • This study investigated the effect of heat treatment conditions not only on the Cr surface crack propagation behaviors but also on the Ni/Cr interfacial reaction characteristics in electroless Ni/electroplated Cr double coating layers on Cu substrate. Clear band layer of Ni-Cr solid solutions were developed at Ni/Cr interface after heat treatment at $750^{\circ}C$ for 6 h. Channeling cracks formed in Cr layer after 1 step heat treatment, that is, heat treatment after Ni/Cr plating, while little channeling cracks formed after 2 step heat treatment, that is, same heat treatments after Ni and Cr plating, respectively, due to residual stress relaxation due to crystallization of Ni layer before Cr plating.

Sensitivity Analysis of Nozzle Geometry Variables for Estimating Residual Stress in RPV CRDM Penetration Nozzle (원자로 상부헤드 관통노즐의 잔류응력 예측을 위한 노즐 형상 변수 민감도 연구)

  • Bae, Hong Yeol;Oh, Chang Young;Kim, Yun Jae;Kim, Kwon Hee;Chae, Soo Won;Kim, Ju Hee
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.3
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    • pp.387-395
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    • 2013
  • Recently, several circumferential cracks were found in the control rod drive mechanism (CRDM) nozzles of U.S. nuclear power plants. According to the accident analyses, coolant leaks were caused by primary water stress corrosion cracking (PWSCC). The tensile residual stresses caused by welding, corrosion sensitive materials, and boric acid solution cause PWSCC. Therefore, an exact estimation of the residual stress is important for reliable operation. In this study, finite element simulations were conducted to investigate the effects of the tube geometry (thickness and radius) on the residual stresses in a J-groove weld for different CRDM tube locations. Two different tube locations were considered (center-hole and steepest side hill tube), and the tube radius and thickness variables ($r_o/t$=2, 3, 4) included two different reference values ($r_o$=51.6, t=16.9mm).

Numerical Calculation of the Far Field Acoustic Pressure from the Unsteady Motion of the Three-dimensional Vortex Filament (삼차원 와선의 비정상 거동에 의한 원거리 음압의 수치해석)

  • Ryu, Ki-Wahn;Lee, Duck-Joo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.6
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    • pp.942-950
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    • 1997
  • Far field acoustic pressure from the evolution and interaction of three-dimensional vortex filament is calculated numerically. A vortex ring is a typical example of the three-dimensional vortex filament. An elliptic vortex ring emits a strong sound signal due to significant distortion and stretching of the vortec filament. The far field acoustic pressure is linearly dependent on the third time derivatives of the vortex positions. A numerical scheme of high resolution is employed to describe in detail the elliptic vortex ring motions which ar highly nonlinear. Descretized vortex filaments are interpolated by using a parametric blending function to remove a possible numerical instability. The distorted vortex filament, owing to the self-induced and the induced velocity from the other vortex segments, is redistributed at each time step. The accuracy and efficiency of the scheme are validated by comparisons with the analytic solution of circular vortex ring interaction.

Seismic Performance of Built-up Concrete Filled Square Composite Column-to beam Connection with Through Diaphragm (관통형 다이아프램을 갖는 조립형 콘크리트 충전 각형 합성기둥-보 접합부의 내진성능)

  • Kim, Sun Hee;Yom, Kyong Soo;Choi, Sung Mo
    • Journal of Korean Society of Steel Construction
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    • v.26 no.5
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    • pp.431-439
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    • 2014
  • Concrete filled tubular columns are widely used because the mutual reaction between the concrete and the tube improves strength and ductility of the columns. In an attempt to secure efficient use of members, built-up square columns featuring large width-thickness ratio and the use of thin steel plates are suggested in this study. In order to evaluate the structural characteristics and seismic performance of the column-to-beam connections of the new shape columns, cyclic load test of T-shaped column-to-beam connections was conducted with variables of diaphragms and concrete-filling. Moment-rotational angle relationship, dissipated energy and failure behavior were compared to evaluate stress transfer mechanism of the new shape built-up square column-to-beam connections associated with the variables.