• 대한기계학회논문집
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• 제17권7호
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• pp.1794-1804
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• 1993

The thermal stress intensity factors for interface cracks of Griffith and symmetric lip cusp types under vertical uniform heat flow in a finite body are calculated by boundary element method. The boundary conditions on the crack surfaces are insulated or fixed to constant temperature. The relationship between the stress intensity factors and the displacements on the nodal point of a crack tip element is derived. The numerical values of the thermal stress intensity factors for interface Griffith crack in an infinite body and for symmetric lip cusp crack in a finite and homogeneous body are compared with the previous solutions. The thermal stress intensity factors for symmetric lip cusp interface crack in a finite body are calculated with respect to various effective crack lengths, configuration parameters, material property ratios and the thermal boundary conditions on the crack surfaces. Under the same outer boundary conditions, there are no appreciable differences in the distribution of thermal stress intensity factors with respect to each material properties. But the effect of crack surface thermal boundary conditions on the thermal stress intensity factors is considerable.

• 한국융합학회논문지
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• 제10권4호
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• pp.209-217
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• 2019

본 연구의 목적은 그로테스크의 개념과 특징을 고찰하고 그로테스크의 회화적 역사를 살펴 본 후 시대별 회화 작품을 응용한 바디페인팅 융합 디자인 작품을 제시함으로써 창의적이고 독창적인 바디페인팅 디자인의 기초자료를 제시하는데 있다. 연구 방법은 관련 서적과 선행 연구 및 인터넷 자료 등을 토대로 그로테스크와 바디페인팅의 개념 및 특징, 표현기법 등을 이론적으로 고찰하고 시대별로 그로테스크 회화 작품의 이미지를 분석한 후 이를 바탕으로 융합 디자인하여 바디페인팅 작품을 제작하였다. 연구 결과, 바디페인팅 작품 제작을 통해 그로테스크를 비롯한 회화 작품들이 바디페인팅 작가들에게 무한한 상상력과 다양한 주제를 제시할 수 있다는 것을 알 수 있었다. 이러한 결과는 향 후 바디페인팅 작품을 디자인하는데 미술작품의 역할이 크게 작용할 수 있음을 시사하는 바이다. 또한 이를 좀 더 학문적이고 체계적으로 연구하고자 하는 이들에게 융합 디자인의 영감을 제시하여 예술 작품으로서의 바디페인팅이 하나의 독자적 영역을 공고히 하는데 도움이 되기를 기대한다.

• 대한기계학회논문집
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• 제14권3호
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• pp.624-635
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• 1990

본 연구에서는 마멸과정을 선형파괴역학적 관점에서 해석하여, 탄성체의 표면 에 산재되어 있는 표면균열의 전파거동을 마멸과정규명의 입장에서 살펴보고자 한다. 우선 마멸거동에 관한 파괴역학적 접근방식에 의한 마멸이론의 확립을 위해서, 표면균 열이 내부균열보다 그 전파 가능성이 높다고 한 Keer등의 주장에 착안하여 Hertz 접촉 압력하의 경사진 표면균열의 전파거동을 선형파괴역학적으로 해석하고자 한다. 이론 해석에 있어서는 표면균열을 인상전립의 연속분포로 치환하고, 전립밀도분포함수에 관 한 특이적분방정식을 유도해서 Erdogangupta의 방법을 이용하여 그 해를 구하였다.

• Journal of Radiation Protection and Research
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• 제10권2호
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• pp.155-159
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• 1985

무한균질공기(無限均質空氣)에 방사성물질(放射性物質)이 균일(均一)하게 분포(分布)된 방사성운(放射性雲)에서 피폭선량(被曝線量)은 일반적(一般的)으로 단일(單一)에너지 점등방선원(點等方線源)커넬 방법(方法)에 의하여 계산(計算)하고 있다. 이 방법(方法)의 가장 큰 제한성(制限性)은 인체표면(人體表面)에서만의 선량(線量)을 개산(槪算)한다는 사실(事實)이다. 이와같은제한성(制限性)을 제거(除去)하기 위하여, 이 보고서(報告書)는 감마선방출대형방사성운(線放出大型放射性雲) 속에서 방사선량계산(放射線量計算)에 인체표면(人體表面)에 입사(入射)되는 산난광자(散亂光子)스펙트럼을 고려(考慮)한 다른 접근방법(接近方法)을 도입(導入)하였으며, 그 결과(結果)는 다른 연구자(硏究者)들의 결과(結果)와 잘 일치(一致)하였다. 여기에서 얻은 결과(結果)는 현재(現在) 연구(硏究)가 진행중(進行中)인 무한(無限) 또는 반무한균질공기방사선운(半無限均質空氣放射線雲)에서 MIRD팬텀내 흡수선량분포결정(吸收線量分布決定)의 입력자료(入力資料로서 이용(利用)될 것이다.

• 한국기계연구소 소보
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• 통권14호
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• pp.135-144
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• 1985

A method is described to obtain the first order force and second order steady force on the fixed two dimensional submerged or semisubmerged cylinders at infinite depth of water due to regular waves. The first order diffraction wave velocity potential which describes the flow diffracted by a body is obtained numerically using source distribution method on the mean wetted surface. And a technique to remove the irregular frequency phenomena of the source distribution method is also applied. The second order steady force is calculates by means of direct integration of the pressures on the body as derived from the first order velocity potential and is also computed by means of reflection wave height derives from momentum conservation theory. The results are compared with those of published works, and show good agreement.

• 한국해양공학회지
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• 제11권2호
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• pp.91-99
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• 1997

This paper presents theoretical formulations and numerical computations for predicting first-and second-order hydrodynamic force on a ship advvancing in waves. The theoretical formulation leads to linearized radiation and diffration problems solving the three-dimensional Green function integral equations over the mean wetted body surface. Green function representing a translating and pulsating source potantial for infinite water depth is used. In order to solve integral equations for three dimentional flows using Green function efficiently, the Hoff's method is adopted for numerical calculation of the Green function. Based on the first-order solution, the mean seconder-order forces and moments are obtained by directly integrating second-order pressure over the mean wetted body surface. The calculated items are carried out for analyzing the seakeeping characteristics of Series 60. The calculated items are hydrodynamic coefficients, wave exciting forces, frequency response functions and addd resistance in waves.

• 대한기계학회논문집A
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• 제24권4호
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• pp.982-990
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• 2000

The finite element alternating method is extended further for general three dimensional cracks in an isotropic body subjected to the mode I loading. The required analytical solution for a dime dimensional crack in an infinite isotropic body is obtained by solving the integral equations. In order to remove the high singularity in integration, the technique suggested by Keat et al. was used. With the proposed method several example problems are solved in order to check the accuracy and efficiency of the method.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1998년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
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• pp.180-187
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• 1998

One of the major difficulties in the seismic analysis of a dam-reservoir system is the treatment of the energy radiation in the upstream direction of the reservoir. In this paper a new transmitting boundary is presented that can model properly the radiation of energy in the far field direction of a semi-infinite reservoir with constant depth. In the newly developed method, effects of surface wave motion are taken into account and the reservoir-foundation interaction is approximately accounted for with an absorbing boundary condition. If a dam has vertical upstream face and the infinitely long reservoir maintains constant depth, then the proposed transmitting boundary can be directly coupled with the model of dam body. In present study, the dam body is assumed to behave elastically and modeled by finite element method. Seismic responses of a dam model are investigated using the newly developed transmitting boundary.

• International Journal of Computer Science & Network Security
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• 제22권6호
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• pp.139-144
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• 2022

Technological advancements taken the health care industry by a storm by embedding sensors in human body to measure their vitals. These smart solutions provide better and flexible health care to patients, and also easy monitoring for the medical practitioners. However, these innovative solutions provide their own set of challenges. The major challenge faced by embedding sensors in body is the issue of lack of infinite energy source. This work presents a meta-heuristic based routing model using modified PSO, and adopts an energy harvesting scheme to improve the network lifetime. The routing process is governed by modifying the fitness function of PSO to include charge, temperature and other vital factors required for node selection. A reactive routing model is adopted to ensure reliable packet delivery. Experiments have been performed and comparisons indicate that the proposed Energy Harvesting and Modified PSO (EHMP) model demonstrates low overhead, higher network lifetime and better network stability.

• ETRI Journal
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• 제44권1호
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• pp.147-154
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• 2022

We demonstrate a new double-layer structure for stretchable interconnects, where the top surface of a serpentine polyimide support is coated with a thin eutectic gallium-indium liquid metal layer. Because the liquid metal layer is constantly fixed on the solid serpentine body in this liquid-on-solid structure, the overall stretching is accomplished by widening the solid frame itself, with little variation in the total length and cross-sectional area of the current path. Therefore, we can achieve both invariant resistance and infinite fatigue life by combining the stretchable configuration of the underlying body with the freely deformable nature of the top liquid conductor. Further, we fabricated various types of double-layer interconnects as narrow as 10 ㎛ using the roll-painting and lift-off patterning technique based on conventional photolithography and quantitatively validated their beneficial properties. The new interconnecting structure is expected to be widely used in applications requiring high-performance and high-density stretchable circuits owing to its superior reliability and capability to be monolithically integrated with thin-film devices.