• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.4
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• pp.372-382
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• 2006

Most of the conventional breakwaters impermeable breakwaters which block seawater exchange between the outside and inside of the harbors. The blocking of seawater exchange may cause pollution of water in harbors. To solve the water pollution problem, various kinds of seawater exchange breakwaters have been proposed. Their types can be classified into the current type which uses tidal current, and the overtopping type which uses the wave energy. The overtopping type breakwaters require a discharge coefficient to calculate the rate of overtopping into the harbor. The present study is to compute the rate of overtopping with introduction of a correct discharge coefficient and to evaluate the effect of the overtopping type breakwater on the water qualify inside a harbor. The rate of overtopping was computed by using Forchheimer formula with time dependent mild-slope equation for various wave conditions. The formula has been generally used to calculate the overflow discharge in steady state river flows. The discharge coefficient, which is the key parameter of the calculation, was determined by a series of hydraulic model tests. The present scheme was applied to the seawater exchange section of the western breakwater of Jeju New Harbor's and the efficiency of that section was examined. The calculated results showed that the rate of overtopping into the harbor reached about $27.5m^3/s$ in the wave condition (wave height 3.7 m, wave period 8.5s, and wave direction NNW).

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.1
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• pp.34-39
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• 2013

In this study, the quantitative analysis and pattern analysis of the error bounds with respect to recording period were carried out using the wave climate data from coastal areas. Arbitrary recording periods were randomly sampled from one month to six years using the bootstrap method. Based on the analysis, for recording periods less than one year, it was found that the error bounds decreased rapidly as the recording period increased. Meanwhile, the error bounds were found to decrease more slowly for recording periods longer than one year. Assuming the absolute estimate error to be around 10% (${\pm}0.1m$) for an one meter significant wave height condition, the minimum recording period for reaching the estimate error for Sokcho and Geoje-Hongdo stations satisfied this condition with over two years of data, while Anmado station was found to satisfy this condition when using observational data of over three years. The confidence intervals of the significant wave height clearly show an increasing pattern when the percentile value of the wave height increases. Whereas, the confidence intervals of the mean wave period are nearly constant, at around 0.5 seconds except for the tail regions, i.e., 2.5- and 97.5-percentile values. The error bounds for 97.5-percentile values of the wave height necessary for harbor tranquility analysis were found to be 0.75 m, 0.5 m, and 1.2 m in Sokcho, Geoje-Hongdo, and Anmado, respectively.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.1
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• pp.1-9
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• 2015

To satisfy stricter $NO_X$ emission regulations for light- and heavy-duty diesel vehicles, a control algorithm needs to be developed based on a selective catalytic reaction (SCR) dynamics model for chemical reactions. This paper presents the development and validation of a SCR dynamics model through test rig experiments and MATLAB simulations. A nonlinear state space model is proposed based on the mass conservation law of chemical reactions in the SCR dynamics model. Experiments were performed on a test rig to evaluate the effects of the $NO_X$ and $NH_3$ concentrations, gas temperature, and space velocity on the $NO_X$ conversion efficiency for the urea-SCR system. The parameter values of the proposed SCR model were identified using the experimental datasets. Finally, a control-oriented model for an SCR system was developed and validated from the experimental data in a MATLAB simulation. The results of this study should contribute toward developing a closed-loop control strategy for $NO_X$ and $NH_3$ slip reduction in the urea-SCR system for an actual engine test bench.

• Investigative Magnetic Resonance Imaging
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• v.3 no.2
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• pp.188-195
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• 1999

The fMRI signals are composed of many various signals. It is very difficult to find the accurate parameter for the model of fMRI signal containing only neural activity, though we may estimating the signal patterns by the modeling of several signal components. Besides the nose by the physiologic motion, the motion of object and noise of MR instruments make it more difficult to analyze signals of fMRI. Therefore, it is not easy to select an accurate reference data that can accurately reflect neural activity, and the method of an analysis of various signal patterns containing the information of neural activity is an issue of the post-processing methods for fMRI. In the present study, fMRI data was analyzed with the Independent Component Analysis(ICA) method that doesn't need a priori-knowledge or reference data. ICA can be more effective over the analytic method using cross-correlation analysis and can separate the signal patterns of the signals with delayed response or motion related components. The Principal component Analysis (PCA) threshold, wavelet spatial filtering and analysis of a part of whole images can be used for the reduction of the freedom of data before ICA analysis, and these preceding analyses may be useful for a more effective analysis. As a result, ICA method will be effective for the degree of freedom of the data.

• Korean Journal of Environmental Agriculture
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• v.15 no.2
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• pp.232-238
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• 1996

This study was conducted to find out the optimum condition for $NH_4-N$ removal from wastewater by a zeolite column. The removal efficiency of $NH_4-N$ by a glass column packed with decreased with the increase in initial concentration, percolation velocity and fraction number. The result of multiple stepwise regressions, $NH_4-N$ removal efficiency by the zeolite column showed a high correlationship with various parameters such as percolation velocity, initial concentration, adsorption amount and fraction number. Theoretical formula by parameter coefficients of multiple stepwise regression was found to be $NH_4-N$ removal $efficiency=0.620{\times}amount$ of zeolite $-0.456{\times}percolation$ velocity $-0.212{\times}initial$ concentration $-3.038{\times}fraction$ number+100.1 In the case of the $NH_4-N$ removal efficiency in cattle farming wastewater, the experimental data were nearly coincident with the theoretical formula.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.6
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• pp.361-365
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• 2000

This study was carried out to evaluate yearly variation and stability of yield and yield components of fifteen rice varieties. Yield stability and universal variety parameter of rice varieties were utilized for statistical model developed by Stroike, Grafius, and Finlay respectively. The lowest yearly variation based on coefficient of variation was found in Dasanbyeo for number of panicles/hill, in Jodongji for number of grains/panicle, in Yongmoonbyeo for ripened grain ratio, in Nagdongbyeo for 1,000 grain weight, and in Dasanbyeo for grain yield. Stability analysis by Stroike and Johnson's model revealed that Ilpumbyeo, Hwaseongbyeo, Dongjinbyeo in Japonica type, and And-abyeo and Dasanbyeo in Tongil type had the higher stability above average. Universal varieties analyzed by Grafius model were Ilpumbyeo, Dongjinbyeo, Hwaseongbyeo, Nagdongbyeo, and Jodongji in Japonica, and Dasanbyeo and Samgangbyeo in Tongil type. Damageum, Dongjinbyeo, Hwaseongbyeo and Ilpumbyeo in Japonica, and Dasanbyeo and Yongmoonbyeo in Tongil type were found to be highly stable as analyzed by Finlay ＆ Wilkinson's model. In conclusion, with reference to both grain yield and stability based on above three methods, Ilpumbyeo, Hwaseongbyeo, and Dongjinbyeo in Japonica, and Dasanbyeo in Tongil type were evaluated to be highly year-stable and high-yielding.

• Journal of Embryo Transfer
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• v.22 no.3
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• pp.143-147
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• 2007

Records on 546 Korea native pigs for average daily gain (ADG), age at 70 kg (D70 kg) and backfat thickness (BF) made between 2001 and 2006 in herds on National Institutes of Animal Science in Korea were used to estimate genetic parameters. The data was analyzed by the DF-REML (Derivative-Free Restricted Maximum Likelihood) program of Boldman using a single-trait animal model. Heritabilities were 0.26, 0.09, and 0.29 for ADG, D70 kg and BF, respectively. The phenotypic correlations of ADG with D70 kg and BF were -0.71 and 0.30. The phenotypic correlation of D70 kg with BF was -0.15. The genetic correlations of ADG with D70 kg and BF were -0.11, 0.41, respectively. The genetic correlation of D70 kg with BF was -0.16. The data of weights and measurements on body length, body height and chest width after age at 11 months (days to 330) were shown scarcely less differences compare to data of age at 11 months.

• Journal of fish pathology
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• v.24 no.3
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• pp.225-236
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• 2011

This study was aimed to determine the fish physical status according to the gross and histopathological findings of liver in cultured black rock fish, Sebastes schlegeli. All 47 fish submitted had no marked abnormalities in the external findings. 42.55% of fish showed normal liver, 25.53% yellow liver, 25.53% atrophic brown liver, 4.26% yellowish-green liver and 2.13% fatty liver in gross examination. Grossly normal liver showed no remarkable change in lobular structure but many vacuoles were found in hepatic cell. Hepatic cells took normal roundish, polygonal shapes containing spherical nuclei. In group of yellow-brown liver, many brown pigments were seen in hepatic cells, MMCs and brown-colored hyaline droplets within cytoplasm of hepatocytes. Yellowish green pigments were seen in hepatic cells and MMCs of yellow green liver and green colored hyaline droplets within hepatocytes. The dilated central veins are highlighted with atrophy of hepatic cells. Outline of atrophic hepatocyte became ambiguous and nucleus frequently become small and pyknotic. Fatty liver showed prominent vacuolar structures in cells as clear spaces or foamy cytoplasm with degenerative nuclei. From these results, it was strongly suggested that hepatic gross and histological findings could be used as important and critical health parameters of fish prior to progression to substantial manifestation as clinical disease.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.1
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• pp.31-38
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• 2012

The geo-referencing accuracy of the images acquired by a UAV based multi-sensor system is affected by the accuracy of the mounting parameters involving the relationship between a camera and a GPS/INS system as well as the performance of a GPS/INS system. Therefore, the estimation of the accurate mounting parameters of a multi-sensor system is important. Currently, we are developing a low altitude multi-sensor system based on a UAV, which can monitor target areas in real time for rapid responses for emergency situations such as natural disasters and accidents. In this study, we suggest a system calibration method for the estimation of the mounting parameters of a multi-sensor system like our system. We also generate simulation data with the sensor specifications of our system, and derive an effective flight configuration and the number of ground control points for accurate and efficient system calibration by applying the proposed method to the simulated data. The experimental results indicate that the proposed method can estimate accurate mounting parameters using over five ground control points and flight configuration composed of six strips. In the near future, we plan to estimate mounting parameters of our system using the proposed method and evaluate the geo-referencing accuracy of the acquired sensory data.

• The Korean Journal of Physiology
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• v.28 no.2
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• pp.133-141
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• 1994

The discharge patterns and peripheral nerve inputs to cardiovascular neurons were investigated in rostral ventrolateral medulla (RVLM) and raphe nucleus of cats. The data from the two were compared to determine their roles in cardiovascular regulation and the endogenous analgesic system. Animals were anesthetized with ${\alpha}-chloralose$ and single cell activities were recorded by carbon-filament microelectrode and their relationships with cardiovascular activity were analyzed. In RVLM area, a total of thirty-three cells were identified as cardiovascular neurons. During one cardiac cycle, the mean discharge rate of the neurons was $1.96{\pm}0.29$ and the peak activity was observed 45 ms after the systolic peak of arterial blood pressure. Thirteen cells could be activated antidromically by stimulation of the the $T_2$ intermediolateral nucleus. Forty-three raphe neurons were identified as cardiovascular neurons whose mean discharge rate during one cardiac cycle was $1.02{\pm}0.12$. None of these cells could be activated antidromically. Study of the interval time histogram of RVLM neurons revealed that the time to the first peak was $128{\pm}20.0\;ms$, being shorter than the period of a cardiac cycle. The same parameter found from the raphe neurons was $481{\pm}67.2\;ms$, which was much longer than the cardiac cycle length. Of seventeen RVLM neurons examined ten received only the peripheral $A{\delta}-afferent$ inputs, whereas six RVLM neurons received both $A{\delta}-$ and C-inputs; the remaining one cell received an inhibitory peripheral C-input. In contrast, nine of eleven raphe neurons were found to receive $A{\delta}-inputs$ only. We conclude that the main output of cardiovascular regulatory influences are mediated through the RVLM neurons. The cardiovascular neurons in the raphe nucleus appear to serve as interneurons transferring cardiovascular afferent information to the raphespinal neurons mediating the endogenous analgesic mechanisms.