• Ocean Systems Engineering
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• 제4권3호
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• pp.201-213
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• 2014

Wave run-up is an important issue in offshore engineering, which is tightly related to the loads on the marine structures. In this study, a series of physical experiments have been performed to investigate the wave run-up around a vertical cylinder in transitional water depth. The wave run-ups of regular waves, irregular waves and focused waves have been presented and the characteristics in frequency domain have been investigated with the FFT and wavelet transform methods. This study focuses on the nonlinear features of the wave run-up and the interaction between the wave run-up and the cylinder. The results show that the nonlinear interaction between the waves and the structures might result wave run-up components of higher frequencies. The wave run-ups of the moderate irregular waves exhibit 2nd order nonlinear characteristics. For the focused waves, the incident waves are of strong nonlinearity and the wavelet coherence analysis reveals that the wave run-up at focal moment contains combined contributions from almost all the frequency components of the focused wave sequence and the contributions of frequency components up to 4th order harmonic levels are recommended to be included.

• 한국해양공학회지
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• 제34권4호
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• pp.245-252
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• 2020

Wave run-up is an important phenomenon that should be considered in ocean structure design. In this study, the wave run-up of a surface-piercing circular cylinder was calculated in the time domain using the three-dimensional linear and fully nonlinear numerical wave tank (NWT) techniques. The NWT was based on the boundary element method and the mixed Eulerian and Lagrangian method. Stokes second-order waves were applied to evaluate the effect of the nonlinear waves on wave run-up, and an artificial damping zone was adopted to reduce the amount of reflected and re-reflected waves from the sidewall of the NWT. Parametric studies were conducted to determine the effect of wavelength, wave steepness, and the draft of the cylinder on the wave run-up of the cylinder. The maximum wave run-up value occurred at 0°, which was in front of the cylinder, and the minimum value occurred near the circumferential angle of 135°. As the diffraction parameter increased, the wave run-up increased up to 1.7 times the wave height. Furthermore, the wave run-up was 4% higher than the linear wave when the wave steepness was 1/35. In particular, the crest height of the wave run-up increased by 8%.

• 물과 미래
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• 제19권4호
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• pp.329-338
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• 1986

the purpose of this study is to estimate the storage deficit by Run's Characteristics of (-)Run-length and (-)Run-sum. Runoff data are obtained from the guaging stations of Y대-Ju in Hanriver Basin, Wae-Gwan in Nak Dong River Basin and Gyo Am in Geum River Basin. In order to estimate the storage deficit, runhydrographs are established with each return period of 10, 30, ......, 200 years and regression equation is derived from relationship between (-) run-length and storage deficit. From the comparison of estimated reservoir storage with observed values., it was proved that this suggested method can be used for the estimation of the storage deficit.

• Asian Journal of Atmospheric Environment
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• 제12권1호
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• pp.30-36
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• 2018

This study investigates the relationship between economic growth, energy consumption, trade openness, population density, and carbon dioxide ($CO_2$) emissions in Bangladesh for the period of 1975 to 2013. It applies the Autoregressive Distributed Lag (ARDL) bounds testing approach to cointegration for establishing the existence of a long-run relationship. The bounds tests suggest that the variables of interest are bound together in the long-run when $CO_2$ emissions is the dependent variable. The results indicate that energy consumption has statistically significant positive effect on $CO_2$ emissions both in the short-run and long-run. The effect of population density is significant in long-run, but not in short-run. The estimated coefficients for economic growth and trade liberalization are negative and insignificant both in short-run and long-run. The paper suggests that the government of Bangladesh should undertake the policy actions to develop alternative energy sources which would not emit much $CO_2$.

• The Journal of Asian Finance, Economics and Business
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• 제7권6호
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• pp.185-195
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• 2020

The study investigates the impact of globalization on coal consumption in Vietnam. This study employs an autoregressed distributed lag approach on time series data for the period of 1990 to 2017. The study tests the stationary, cointegration of time series data and utilizes autoregressed distributed lag modeling technique to determine the short-run and long-run relationship among coal consumption, globalization, income, population, and CO₂ emissions. The results show that globalization increases coal consumption in Vietnam in the long run. The results also show that rapid economic growth promotes more coal consumption in the short run as well as in the long run. Moreover, higher population reduces coal consumption, and CO₂ emissions decrease coal consumption both in the short run and the long run. The findings of the study suggest that globalization increases coal consumption in Vietnam in the long run. This result suggests that the increase in globalization level in Vietnam increases coal consumption. An interesting finding is that higher population reduces coal consumption, and population is an important factor towards the lessening in coal consumption. The findings confirm that environmental pollution decreases coal consumption in the short run and the long run. This implies that coal consumption may be green consumption in Vietnam.

• 한국물환경학회지
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• 제20권5호
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• pp.457-465
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• 2004

The objective of this study is to evaluate the possibility to apply the Moving Bed Biofilm Reactor(MBBR) in the activated sludge treatment process with existing aerobic HRT. Optimal operation conditions were assumed according to the analysis of organic matter and nutrients removal efficiencies depending on loading variations. The process was operated under different conditions: RUN I(HRT=7.14hr, $I{\cdot}R=100%$), RUN II(HRT=6.22hr, $I{\cdot}R=100%$), RUN III(HRT=6.22 hr, $I{\cdot}R=150%$), RUN IV(HRT=6.22hr, $I{\cdot}R=200%$), the TBOD removal efficien cies are 88%, 88.5%, 94.6%, 97.6%, respectively. Overall TSS removal efficiency is 90%, and it is increasing in RUN IV. In the case of Nitrogen, the highest removal efficiency of 90% was observed in RUN III and RUN IV, Nitrification and Denitrification rates are 0.013-0.016kg $NH_3-N/kg$ Mv-d and 0.009-0.019kg $NO_3/kg$ Mv-d, respectively. Phosphorus removal efficiencies are 89.6% in RUN I, 91.5% in RUN II, 84.3% in RUN III, and 76.4% in RUN IV. The process under shorter SRT yields better performance in terms of phosphorus removal. It was noticed that to achieve the effluent phosphorus concentration ofless than 1mg/L and removal efficiency higher than 80%, SRT should not be longer than 10 days. Experimental result shows that HRT of 6.22 hours is suitable for this treatment process, and, as a result, the aerobic reactor including moving media and DO depletion tank have a sufficient effect to the process performance.

• Journal of Gastric Cancer
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• 제20권1호
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• pp.81-94
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• 2020

Purpose: Duodenal stump leakage (DSL) is a potentially fatal complication that can occur after gastrectomy, but its underlying risk factors are unclear. This study aimed to investigate the risk factors and management of DSL after laparoscopic radical gastrectomy for gastric cancer (GC). Materials and Methods: Relevant data were collected from several prospective databases to retrospectively analyze the data of GC patients who underwent Billroth II (B-II) or Rouxen-Y (R-Y) reconstruction after laparoscopic gastrectomy from 2 institutions (Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, and HwaMei Hospital, University of Chinese Academy of Sciences). The DSL risk factors were analyzed using univariate and multivariate analysis regression. Results: A total of 810 patients were eligible for our analysis (426 with R-Y, 384 with B-II with Braun). Eleven patients had DSL (1.36%). Body mass index (BMI), elevated preoperative C-reactive protein (CRP) level, and unreinforced duodenal stump were the independent risk factors for DSL. DSL was diagnosed in 2-12 days, with a median of 8 days. Seven patients received conservative treatment, 3 patients received puncture treatment, and only 1 patient required reoperation. All patients recovered successfully after treatment. Conclusions: The risk factors of DSL were BMI ≥24 kg/㎡, elevated preoperative CRP level, and unreinforced duodenal stump. Nonsurgical treatments for DSL are preferred.

• Ocean and Polar Research
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• 제37권1호
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• pp.1-9
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• 2015

An approach based on the combined use of a 2D shallow water model and analytical 1D long wave run-up theory is proposed which facilitates the forecasting of tsunami run-up heights in a more rapid way, compared with the statistical or empirical run-up ratio method or resorting to complicated coastal inundation models. Its application is advantageous for long-term tsunami predictions based on the modeling of many prognostic tsunami scenarios. The modeling of the Chilean tsunami on February 27, 2010 has been performed, and the estimations of run-up heights are found to be in good agreement with available observations.

• 제어로봇시스템학회논문지
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• 제6권1호
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• pp.104-111
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• 2000

A fuzzy logic Run-by-Run(RbR) controller and an in -line wafer characteristics prediction scheme for the rapid thermal processing system have been developed for the study of process repeatability. The fuzzy logic RbR controller provides a framework for controlling a process which is subject to disturbances such as shifts and drifts as a normal part of its operation. The fuzzy logic RbR controller combines the advantages of both fuzzy logic and feedback control. It has two components : fuzzy logic diagnostic system and model modification system. At first, a neural network model is constructed with the I/O data collected during the designed experiments. The wafer state after each run is assessed by the fuzzy logic diagnostic system with featuring step. The model modification system updates the existing neural network process model in case of process shift or drift, and then select a new recipe based on the updated model using genetic algorithm. After this procedure, wafer characteristics are predicted from the in-line wafer characteristics prediction model with principal component analysis. The fuzzy logic RbR controller has been applied to the control of Titanium SALICIDE process. After completing all of the above, it follows that: 1) the fuzzy logic RbR controller can compensate the process draft, and 2) the in-line wafer characteristics prediction scheme can reduce the measurement cost and time.

• 한국경영과학회지
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• 제29권1호
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• pp.31-41
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• 2004

This study analyzes the structure of the variations In the domestic bank earnings and examines their dynamic features by estimating the short-run response and the long-run adjustment Process after the changes in financial market variables. A system of the equations for the bank stock price index and KOSPI is formulated to utilize the whole information in the market and simultaneously estimated to identify the relationships between the market variables and the bank earnings. Since the bank stock price is found to be responsive to changes in none of the market variables in the short run, while being relatively responsive to dollar exchange rate and business state, It implies that a good economic conditions and a stable foreign exchange rate should be maintained to Improve the level of the stock price In the long run. In addition, the dynamic structure of the responses of the bank stock price index and KOSPI to the initial changes in the market variable are compared and anlayzed. The response of the bank stock price appears to take much longer in adjusting to the long-run eouilibrium level than that of KOSPI. As a result, the cumulative response of the bank stock price index over time is found much bigger than that of HOSPI.