• International Journal of Naval Architecture and Ocean Engineering
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• 제9권3호
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• pp.282-291
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• 2017

The main aim of this study is to investigate the effect of berm breakwater on wave run-up. A total of 200 numerical analysis tests have been carried out in this paper to investigate the effect of berm width, wave height, and wave period on the wave run-up, using an integrating technique of Computer-Aided Design (CAD) and Computational Fluid Dynamics (CFD). Direct application of Navier Stokes equations within the berm width has been used to provide a more reliable approach for studying the wave run-up over berm breakwaters. A well tested Reynolds-averaged Navier-Stokes (RANS) code with the Volume of Fluid (VOF) scheme was adopted for numerical computations. The computational results were compared with theoretical data to validate the model outputs. Numerical results showed that the simulation method can provide accurate estimations for wave run-up over berm breakwaters. It was found that the wave run-up may be decreased by increasing the berm width up to about 36 percent. Furthermore, the wave run-up may increase by increasing the wave height and wave period up to about 53 and 36 percent, respectively. These results may convince the engineers to use this model for design of berm breakwater in actual scale by calculating the Reynolds numbers.

• 국제지역연구
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• 제13권2호
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• pp.277-297
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• 2009

이 논문은 외환위기 이후 1998년 1월 ~ 2008년 7월 까지의 한 일 주가와 KRW/JPY 실질 환율간의 장 단기 균형관계를 분석하였다. 실증분석은 월별자료를 사용하여 계절조정에서 오는 편의(bias)를 극복하기 위하여 자료를 계절조정하지 않고 계절성을 모형에 반영하여 단위근 검정과 VEC모델을 분석하였다. 실증분석결과 한일 주가와 환율간 장기균형관계에 대한 강한 증거를 발견하였다. 이는 한 일 양국간 어느 한 국가에 대한 시장예측은 다른 국가 시장에 대한 예측이 가능하다는 것으로 효율시장가설이 위배됨을 의미한다. 한국의 주가와 KRW/JPY 실질 환율 간 장기 음(-)의 부호를 나타내 국내통화의 절하는 국내기업을 더 경쟁적으로 만들어 수출의 증가를 이끌기 때문에 주가를 상승시키며, 주가와 환율간 음(negative)의 상관관계를 의미한다는 전통적 가설을 지지하는 것으로 나타났다.

• The Journal of Asian Finance, Economics and Business
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• 제7권1호
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• pp.37-46
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• 2020

The paper examines the dynamic relationship of domestic credit and stock market liquidity on the economic growth of the Philippines from 1995 to 2018 applying the autoregressive distributed lag (ARDL) bounds testing approach to cointegration, together with Granger causality test based on vector error correction model (VECM). The ARDL model indicated a long-run relationship of domestic credit and stock market liquidity on GDP growth. When the GDP per capita is the dependent variable there is weak cointegration. Also, the Johansen cointegration test confirmed the existence of long-run relationship of domestic credit and stock market liquidity both on GDP growth and GDP per capita. The VECM concludes a long-run causality running from domestic credit and stock market liquidity to GDP growth. At levels, domestic credit has significant short-run causal relationship with GDP growth. As for stock market liquidity at first lag, has significant short-run causal relationship with GDP growth. With regards to VECM for GDP per capita, domestic credit and stock market liquidity indicates no significant dynamic adjustment to a new equilibrium if a disturbance occurs in the whole system. At levels, the results indicated the presence of short-run causality from stock market liquidity and GDP per capita. The CUSUMSQ plot complements the findings of the CUSUM plot that the estimated models for GDP growth and GDP per capita were stable.

• Asian Pacific Journal of Cancer Prevention
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• 제14권10호
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• pp.6151-6158
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• 2013

Radio frequency ablation (RFA) is an effective means of achieving local control of liver cancer. It is a particularly suitable mode of therapy for small and favorably located tumors. However, local progression rates are substantially higher for large tumors (>3.0 cm). In the current study, we report on a mathematical model based on geometric optimization to treat large liver tumors. A database of mathematical models relevant to the configuration of liver cancer was also established. The specific placement of electrodes and the frequency of ablation were also optimized. In addition, three types of liver cancer lesion were simulated by computer guidance incorporating mathematical models. This approach can be expected to provide a more effective and rationale mechanism for employing RFA in the therapy of hepatic carcinoma.

• 대한의용생체공학회:의공학회지
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• 제13권1호
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• pp.33-38
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• 1992

A new approach to texture classification for quantitative ultrasound liver diagnosis using run difference matrix was developed. The run difference matrix comprised the gray level difference along with a distances. From this run difference matrix, we defined several vectors and parameters such as DOD, DGD, DAD vector, SHP, SMO, SMG, LDE, LDEL etc. Each parameter values calculated in fatty, cirrhotic, normal and chronic hepatitic liver images were plotted in a plane and we found that RDM method was more sensitive to small structural changes than the conventional run length method and showed improved classification ability between the diseases.

• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 2004년도 품질경영모델을 통한 가치 창출
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• pp.413-418
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• 2004

The bounded adjustment is known to be more efficient than repeated adjustment when the cost is incurred for engineering process control. The procedure of the bounded adjustment is to adjust the process when the one-step predicted deviation exceeds the adjustment limit by the amount of the prediction. In this paper, two run rules are proposed and studied in order to improve the efficiency of the traditional bounded adjustment procedure. The efficiency is studied in terms of the standardized cost through Monte Carlo simulation when the procedure is operated with and without the run rules. The adjustment procedure operated with run rules turns out to be more robust for changes in the process and cost parameters. The Markov chain approach for calculating the properties of the run rules is also studied.

• Journal of the Korean Data and Information Science Society
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• 제15권3호
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• pp.633-644
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• 2004

Exponentially Weighted Moving Average(EWMA) control chart for variance-covariance matrix of several quality characteristics based on accumulate-combine approach has proposed. Numerical computations show that multivariate EWMA chart based on accumulate-combine approach is more efficient than corresponding multivariate EWMA chart based on combine-accumulate approach.

• 한국해안해양공학회지
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• 제8권1호
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• pp.44-51
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• 1996

해안선에서 장파의 처오름높이의 정확한 산정은 공학적인 측면에서 매우 중요하다. 본 논문에서는 크노이드파 이론을 이용하여 장파의 처오름높이에 관한 연구를 하였다. 크노이드파는 파형이 복잡하여 발생과 처오름높이 산정이 매우 어렵다. 본 연구에서는 경계요소법을 이용하여 급경사 지형에서 크노이드파의 처오름높이를 계산한다. 일반적으로 크노이드파의 처오름높이는 동일한 파고를 갖는 고립파의 처오름높이보다는 작지만, 동일한 파고와 파장을 갖는 정현파의 것보다는 항상 크다. 크노이드파의 처오를높이는 또한 파장이 상대적으로 짧을 경우에는 파장에 따라 단순히 증가하지 않으며, 파장이 매우 커지면 고립파의 처오름높이에 점근적으로 접근한다. 경계요소법에 의해 계산된 크노이드파의 처오름높이는 기존의 수리실험 결과와 대체로 일치한다.

• Journal of the Korean Data and Information Science Society
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• 제19권4호
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• pp.1345-1352
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• 2008

An inventory with constant demand is studied. We adopt a renewal argument to obtain the transient and stationary distribution of the level of the inventory. We show that the stationary distribution can be also derived by making use of either the level crossing technique or the renewal reward theorem. After assigning several managing costs to the inventory, we calculate the long-run average cost per unit time. A numerical example is illustrated to show how we optimize the inventory.

• 대한산업공학회지
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• 제13권2호
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• pp.97-103
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• 1987

Skip-Lot sampling plan is formulated in terms of renewal process. This approach facilitates studying the average outgoing quality in a short production run of length t, AOQ (t). By numerical studies it is found that the long-run average outgoing quality (AOQ) greatly overestimates AOQ (t) for short runs.