• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2003.08a
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• pp.63-70
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• 2003

Berkhoff(1972)는 해저 경사가 완만한 지형에서의 파랑 변형을 계산하는 완경사 방정식을 제안하였다. 이 방정식은 수식이 매우 간단하면서도 비교적 정확하게 파랑을 예측할 수 있어 현재까지도 해안공학 전반에 걸쳐 많이 적용되고 있다. 그러나 Berkhoff(1972)의 완경사 방정식은 계산이 비교적 번거로워 현재는 계산하기 편리한 포물형 완경사 방정식(Radder,1979) 또는 쌍곡선형 완경사 방정식(Copeland,1985) 등의 근사 모델을 사용하고 있다. 하지만, 이러한 근사모델은 지배방정식을 유도할 때 생기는 가정들에 의해 실제현장 적용성과 해의 정확성에는 언제나 일정한 한계가 있다. (중략)

• Journal of Korean Society of Industrial and Systems Engineering
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• v.31 no.4
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• pp.29-40
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• 2008

완제품 생산을 위하여 특별한 사양의 커스텀 부품이 필요한 경우 부품 공급자의 공급능력은 완제품 생산자의 생산능력을 제한하는 요소로 작용하여 궁극적으로 완제품 고객 서비스 수준에 큰 영향을 미친다. 완제품 수요가 불확실한 경우 수요 변동에 따른 부품 공급량 증감을 허용하는 커스텀 부품 공급자의 유연성은 완제품 생산자에게 목표 고객 서비스 수준을 만족하기 위한 부품 조달 비용을 절감할 수 있도록 하는 등의 이익을 가져온다. 본 논문에서는 이러한 커스텀 부품 공급 계약의 유연성이 갖는 가치를 완제품 생산자 측면에서 분석하는 방안을 제시한다.

• Journal of Korean Orthopaedic Sports Medicine
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• v.11 no.1
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• pp.17-23
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• 2012

Wrist arthroscopy has gained popularity and it is applied to a variety of disease for diagnosis and management. In this review article, recent literature review as well as traditional indications is described.

• Cross-Cultural Studies
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• v.41
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• pp.57-84
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• 2015

During the Japanese rule, there was an abundance of Japanese writers using colonial Taiwan as the backdrop for their work. However, after Japan's surrender and Taiwan's independence, such writers became nearly invisible. With recent relations between Taiwan and Japan drawing closer, novels and films tracing the modern relationship of the two nations are continually being introduced. Tsushima Yuko's 2008 novel Too Savage and Yoshida Shuichi's 2009 work Road also sprout from the shift in the two countries' and East Asia's historic and political atmosphere. The two books are similar in the sense that they both use countries as the backdrop and recall colonial times. However, the perspectives of the two greatly differ. This paper will compare the meaning behind the narrative strategies that the two authors take in remembering colonial Taiwan and the relationship of the two countries. It will be quite meaningful for Koreans to research the recent works of Japanese writers depicting Taiwan, as Korea also shares a similar modern history. It will also be a good opportunity to ruminate on the entangled modern history of the East Asian region and review relevant literature and culture.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.6
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• pp.521-532
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• 2007

In the derivation of mild slope equation, a Galerkin method is used to rigorously form the Sturm-Liouville problem of depth dependent functions. By use of the canonical transformation to the dependent variable of the equation a reduced Helmholtz equation is obtained which exclusively consists of terms proportional to wave number, bottom slope and bottom curvature. Through numerical studies the behavior of terms is shown to play an important role in wave transformations over variable depth and it is proved that their relative magnitudes limit applicability of the mild slope equation(MSE) against the modified mild slope equation(MMSE).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5B
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• pp.493-496
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• 2009

In this study, we derive the extended mild-slope equation in terms of the velocity potential using the Euler-Lagrange equation. First, we follow Kim and Bai (2004) who derive the complementary mild-slope equation in terms of the stream function using the Euler-Lagrange equation and we compare their equation to the existing extended mild-slope equations of the velocity potential. Second, we derive the extended mild-slope equation in terms of the velocity potential using the Euler-Lagrange equation. In the developed equation, the higher-order bottom variation terms are newly developed and found to be the same as those of Massel (1993) and Chamberlain and Porter (1995). The present study makes wide the area of coastal engineering by developing the extended mild-slope equation with a way which has never been used before.

• The Journal of the Korea Contents Association
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• v.12 no.3
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• pp.434-441
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• 2012

An analytic solution to the extended mild-slope equation was derived for waves propagating over an axi-symmetric pit. The water depth inside the pit was in proportion to a power of radial distance from the center of pit. The equation was transformed into the ordinary differential equation using the method of separation of variables. The coefficients of differential terms were expressed as an explicit form composing of the phase and group velocities. The bottom curvature and the square of bottom slope terms, which were added to the extended mild-slope equation, were expressed as power series. Finally, using the Frobenius series, the analytic solution to the extended mild-slope equation was derived. The present analytic solution was validated by comparing with the numerical solution obtained from FEM.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.2
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• pp.117-126
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• 2009

In order to test the accuracy between the modified mild slope equation (MMSE) without evanescent modes and the plane-wave approximation (PA) of eigenfunction expansion method, various numerical results from both models are presented. In this study, analytical solutions of two models are employed, one based on the MMSE derived by Porter (2003) and the other on the scatterer method of PA by Seo (2008a). Judging from direct comparisons against existing results of rapidly varying topography, the PA model gives better predictions of the wave propagation than the MMSE model.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1993.07a
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• pp.29-33
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• 1993

이제까지 천해역에서의 파랑변형을 계산하는 여러가지 수치모형이 제안되어 있다. 그 가운데 Berkhoff(1972)가 유도한 완경사방정식을 수치계산이 쉽고, 쇄파감쇠 및 반사의 고려가 용이한 형태로 개량한 환산·경도(1985)의 시간의존 쌍곡선형 완경사방정식은 널리 이용되고 있다. 계산대상영역에 파가 비스듬하게 입사하는 경우, 외해측 경계뿐만 아니라, 파가 입사하는 측의 측방경계도 입사경계가 될 수 있다. (중략)

• Journal of Ocean Engineering and Technology
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• v.18 no.2
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• pp.18-24
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• 2004

In this study, the Mild slope equation is extended to both rapidly varying topography and nonlinear waves, using the Hamiltonian principle. It is shown that this equation is equivalent to the modified mild-slope equation (Kirby and Misra, 1998) for small amplitude wave, and it is the same form with the nonlinear mild-slope equation (Isobe, 1994) for slowly varying bottom topography. Comparing its numerical solutions with the results of some hydraulic experiments, there is good agreement between them.