• Title/Summary/Keyword: Breaking Process

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Particle-based Numerical Simulation of Continuous Ice Breaking Process around Wedge-type Model Ship (쐐기형 모형선 주위 연속 쇄빙과정에 관한 입자 기반 수치 시뮬레이션)

  • Ren, Di;Sin, Woo-Jin;Kim, Dong-Hyun;Park, Jong-Chun;Jeong, Seong-Yeob
    • Journal of the Society of Naval Architects of Korea
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    • v.57 no.1
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    • pp.23-34
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    • 2020
  • This paper covers the development of prediction techniques for ice load on ice-breakers operating in continuous ice-breaking under level ice conditions using particle-based continuum mechanics. Ice is assumed to be a linear elastic material until the fracture occurs. The maximum normal stress theory is used for the criterion of fracture. The location of the crack can be expressed using a local scalar function consisting of the gradient of the first principal stress and the corresponding eigen-vector. This expression is used to determine the relative position of particle pair to the new crack. The Hertz contact model is introduced to consider the collisions between ice fragments and the collisions between hull and ice fragments. In order to verify the developed technique, the simulation results for the three-point bending problems of ice-specimen and the continuous ice-breaking problem around a wedge-type model ship with bow angle of 20° are compared with the experimental results carrying out at Korea Research Institute of Ships and Ocean Engineering (KRISO).

A Study on the Design Development Methods and the Characteristics of Zero Waste Fashion Design (최소폐기물 패션디자인의 디자인 개발방식 및 특성 연구)

  • Han, Seung Soo;Suh, Seung Hee
    • Journal of the Korean Society of Costume
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    • v.66 no.4
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    • pp.61-76
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    • 2016
  • The importance of environment has come into focus recently, and this has led to increased attention on zero waste fashion design as a method to minimize waste from the production stage of fashion goods. The purpose of this study was to analyze the development method types and the characteristics of zero waste fashion design in order to study the eco-friendly meanings of zero waste fashion design, as well as its meaning as creative design development methods. Through the case analysis of recent designs, the design types of zero waste fashion design were largely classified into cut and sew, folding, draping, and non-woven types, and they were classified again according to the characteristics of production process. According to the result of analyzing fashion design development methods of zero waste fashion designs based on the process of completing design, they were classified into pattern making, computer programming, draping, assembling of the unit, and non-woven moulding methods, and the aspect of combined use rather than utilization of one method appeared. Formative characteristics of zero waste fashion design included decorative beauty, formative beauty, and transformable beauty and its design characteristics were fortuity and unexpected properties, breaking stereotypes, structural flexibility and futuristic innovation.

Comparison of Fluid Modeling Methods Based on SPH and ISPH for a Buoy Design for a Wave Energy Converter (파력발전기 부유체설계를 위한 SPH와 ISPH 유체모델링 기법 비교)

  • Jun, Chul-Woong;Sohn, Jeong-Hyun;Yang, Min-Seok
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.3
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    • pp.94-99
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    • 2017
  • The buoy of the wave energy converter moves by direct contact with the fluid. In order to design a buoy by using the numerical method, it is necessary to analyze not only the contact with the fluid but also the exact behavior of the fluid. In this paper, differences between weakly compressible smoothed particle hydrodynamics (WCSPH) and incompressible smoothed particle hydrodynamics (ISPH) are compared and analyzed for two-dimensional dam breaking simulation. ABAQUS, which is a commercial analysis program, is used for WCSPH analysis. A laboratory code is developed for ISPH analysis. The surface shape, the velocity, and the pressure pattern of the fluid are compared. The results of the laboratory code show the similar tendencies with those of ABAQUS, and there is a little difference in the pressure result.

Measurement of Sounds Radiated of Phantom Piezoelectric Extracorporeal Shock Wave Lithotripter and Their Analysis (체외 충격파 결석 파쇄 장치에 의한 대상물 파쇄시의 발생음의 측정과 해석)

  • Jang, Yun-Seok;Park, Mu-Hun
    • The Journal of the Acoustical Society of Korea
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    • v.16 no.6
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    • pp.36-40
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    • 1997
  • The effectiveness of Extracorporeal Shock Wave Lithotripter(ESWL) for the therapy of calculus has been generally known in the field of urology. However, there are very little paper investigated about physical characteristics of sounds radiated when phantom is shotting with shock waves. Therefore, this paper, firstly, investigates the sounds radiated when impact is applied to the phantom with a single shot by an impact hammer and a clinical ESWL Next, it determines the variance of the sounds radiated during the breaking process using a piece of chalk as a phantom of a calculus. These results will be applied to the examination of the existence of the calculus at the focus and the monitoring the breaking process.

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Characteristics of Nick Knight's Works as a Fashion Visual Maker (패션 비주얼 메이커 닉 나이트(Nick Knight)의 작품특성)

  • Kim, Ji Young
    • Journal of the Korean Society of Costume
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    • v.63 no.4
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    • pp.101-117
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    • 2013
  • The purpose of this study is to consider the works of Nick Knight, the most influential fashion visual maker, to find out the characteristics of his works. For the research method, literature reviews were done by studying his book, viewing the articles on his official web site, reading journal review of his works and his interview articles. For the work analysis, fashion brands 'Christian Dior', 'Alexander McQueen', 'Martin Margiela', 'Hussein Chalayan' and 'Gareth Pugh' that have worked with Nick Knight were selected. The characteristics of his fashion works were derived from overall analysis of fashion visual works. The characteristics of Nick Knight's works are as follows. First is the 'innovation of image expression'. He used digital infra in advance and introduced digital images at the initial stage. He used fashion films as the means of communication and tried new image expressions in 3D. Second is 'breaking down the boundaries of creating process'. He worked with various field experts to make high quality works. He invited the public to participate in his creative process through the internet. Third is 'breaking down the categories of aesthetic expression'. He provided a wide variety of aesthetic standard and refused aesthetic stereotype. He broke the boundaries between fashion and art with a unique technique and high values.

The Changes of the Textured Yam Physical Properties in Polyester Interlacing Texturing Process (I) -The Effect of Nozzle Diameter and Tension Ring- (폴리에스테르 인터레이싱 텍스쳐가공 공정에서 가공사의 강신도와 인터레이싱 수의 변화 (I) -노즐의 지름과 텐션 링의 영향-)

  • Lee, Choon-Gil;Oh, Bong-Hyo
    • Fashion & Textile Research Journal
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    • v.1 no.2
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    • pp.166-172
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    • 1999
  • An experimental investigation has done for studying the changes of physical properties of the air-jet textured polyester yarn. Through the experiments of polyester 85/72 drawn yarn and 50/36 partially oriented yarn doubling' the following results are obtained. The tenacity of textured yarn decreased as the number of tension rings increased when the nozzle diameter was 1.2 mm. In the case when the tension ring was not used during the texturing process, the tenacity of textured yarn decreased as the nozzle diameter increased. But this tendency changed according to the number of tension rings used, the diameter of the nozzle, and yarn take-up speed. Breaking elongation decreased as the number of tension rings increased from one to four and the take-up speed increased at diameter 1.2 mm of the nozzle. The higher the diameter of the the nozzle the higher the breaking elongation until 1.4 mm. The number of interlacing went down as the diameter of the nozzle increased and the take-up speed of the yarn increased. The higher the number of tension rings, the lower the number of interlacing.

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Vibration Analysis During Breaking Process of Phantom Induced by Shock Wave for Medical Treatment (의료용 충격파에 의할 대상물의 파쇄진행에 따른 진동해석)

  • Park Kyu-Chil;Jang Yun-Seok
    • The Journal of the Acoustical Society of Korea
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    • v.25 no.1
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    • pp.43-48
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    • 2006
  • When the vibration of a phantom induced by Extracorporeal Shock Wave Lithotripter (ESWL) was investigated. we found the fact that the Peak frequency in the Power spectrum shifts from high frequency to low frequency as the number of shots increases[2]. The fact was confirmed experimentally by detecting the peak frequency obtained from the vibrations of bronze models[3]. This Paper investigates the experimental results. For the Purpose. we carried out the computer simulation using the finite element method. It is found that the results from the experiments are computer by computer simulation.

Experimental crack analyses of concrete-like CSCBD specimens using a higher order DDM

  • Haeri, Hadi
    • Computers and Concrete
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    • v.16 no.6
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    • pp.881-896
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    • 2015
  • A simultaneous analytical, experimental and numerical analysis of crack initiation, propagation and breaking process of the Central Straight through Crack Brazilian Disk (CSCBD) specimens under diametrical compression is carried out. Brazilian disc tests are being accomplished to evaluate the fracturing process based on stress intensity factors (SIFs). The effects of crack inclination angle and crack length on the fracturing processes have been investigated. The same experimental specimens have been numerically modeled by a higher order indirect boundary element method (HDDM). These numerical results are compared with the existing experimental results proving the accuracy and validity of the proposed numerical method.

Determination of Stress Profiles by Fractography in Single Ion-exchanged Glass (파괴분석을 이용한 단일이온교환된 유리의 응력 형성 관찰)

  • 이회관;강원호
    • Journal of the Microelectronics and Packaging Society
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    • v.10 no.4
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    • pp.61-64
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    • 2003
  • The fractography was used to observe the stress profile on a single ion-exchanged glass. In the processing, the temperature was varied during the ion exchange, and then the stress profile on the single ion-exchanged glass was shifted from glass surface to slightly below the glass surface. The hackle mark and mirror surface were varied according to process conditions, and the glass strength was increased with increasing the number of hackle markers. In case of breaking the stress profile by using indenter, the breaking property was similar to the annealed glass.

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Spectra of nonlinear shallow water waves (비선형 천해파의 스펙트라)

  • Zahibo, Narcisse;Didenkulova, Ira;Pelinovsky, Efim
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.19 no.4
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    • pp.355-360
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    • 2007
  • The process of the nonlinear shallow water wave transformation in a basin of a constant depth is studied. Characteristics of the first breaking of the wave are analyzed in details. The Fourier spectrum and steepness of the nonlinear wave are calculated. It is shown that the spectral amplitudes can be expressed using the wave front steepness, which allows the practical estimations.