• Journal of Industrial Technology
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• v.29 no.A
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• pp.67-75
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• 2009

In this study, the investigation of hydraulic characteristics and the pier data for the rivers in Youngseo area of Gangwon Province was carried out and the evaluation and comparison between the values from existing formulas and the values from the model tests was conducted, along with the statistical sensitivity analysis of the elements influencing the scour. As a result, the deviation between the values calculated from the existing formulas and the model tests appeared to be 1.09%~63.98% as the piers were getting larger, which indicated that the existing formulas were not appropriate to estimate the scour in the rivers in Gangwon area. And the formula which estimates the scour with the size of the pier only, among the existing ones, was far behind in estimating the sensitivity because of insufficient incorporation of the hydraulic characteristics, though it is convenient to estimate the value. The sensitivity analysis of the value from the model tests and the depth of the scour proved the significant impact on scour by the size of the pier and water depth, indicating 64% and 36%, respectively. In this study, the formula developed through the regression analysis performed based on the values from the model tests, which appeared to be appropriate for the rivers in Gangwon Province, was proposed.

• The Journal of the Acoustical Society of Korea
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• v.16 no.4
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• pp.29-34
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• 1997

The prediction of detection range of a passive sonar system is essential to estimate the performance and to optimize the operation of a developed sonar system. In this paper, a model for the prediction of detection range in a range-dependent ocean environment based on the sonar equation is developed and tested. The prediction model calculates the transmission loss using PE propagation model, signal excess, and the detection probability at each target depth and range. The detection probability is integrated to give the estimated detection range. In order to validate the developed model, two cases are considered. One is the case when target depth is known. The other is the case when the target depth is unknown. The computational results agree well with the previously published results for the range-independent environment. Also,the developed model is applied to the range-dependent ocean environment where the warm eddy exists. The computational results are shown and discussed. The developed model can be used to find the optimal frequency of detection, as well as the optimal search depth for the given range-dependent ocean environment.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.1
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• pp.57-65
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• 2007

In Korea, most landslides occurr during the rainy season and have shallow failure planes parallel to the slope. For these types of rainfall-induced failures, the most important factor triggering slope unstability is decrease in the matric suction of unsaturated soils with increasing saturation depth by rainfall infiltration. For this reason, estimation of cumulative infiltration has a significance. In this study, infiltration rate and cumulative infiltration are estimated by using both Mein & Larson model based on Green-Ampt infiltration model and using modified Mein & Larson model to which unsteady rainfall is applied. According to the results, the modified model is more reasonable than Mein & Larson method itself in estimation of infiltration rate and saturation depth because of considering real pending condition.

• Progress in Superconductivity and Cryogenics
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• v.4 no.1
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• pp.50-54
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• 2002

Penetration depth of Nb electrodes in $Nb/A1O_x/Nb$ Josephson junctions has been measured by resistive method. For a given applied field, the total flux through the junction is temperature dependent because the penetration depth of Nb electrode varies with temperature. If the total flux equals an integral multiple of the flux quantum at certain temperatures, resistive peaks appear at those temperatures. The penetration depth of Nb can be determined by applying the above condition, The temperature dependence of penetration depth was found to be well described by the two-fluid model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12C
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• pp.738-743
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• 2011

For the high quality 3-D broadcasting, depth maps are important data. Although commercially available depth cameras capture high-accuracy depth maps in real time, their resolutions are much smaller than those of the corresponding color images due to technical limitations. In this paper, we propose the depth map up-sampling method using a high-resolution color image and a low-resolution depth map. We define a random walk probability model in an operation unit which has nearest seed pixels. The proposed method is appropriate to match boundaries between the color image and the depth map. Experimental results show that our method enhances the depth map resolution successfully.

• Communications for Statistical Applications and Methods
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• v.10 no.1
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• pp.167-175
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• 2003

In this paper we develop a robust procedure to estimate regression coefficients for a linear model with censored and truncated data based on simplicial regression depth. Simplicial depth of a point is defined as the proportion of data simplices containing it. This simplicial depth can be extended to regression problem with censored and truncated data. Any line can be given a depth and the deepest regression line is the line with the maximum simplicial regression depth. We show how the proposed regression performs through analyzing AIDS incubation data.

• Journal of the Korean Society of Safety
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• v.30 no.6
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• pp.63-69
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• 2015

In this study, a 2D hydrodynamic model equipped with critical dry depth scheme was developed to reproduce the flow over staircase. The channel geometry of hydraulic experiment conducted by Ishigaki et al. was generated in the computational space, and the developed model was validated against flow properties such as discharge, velocity and momentum. In addition, the water surface profile and the velocity distribution evolved in flow over two layers staircases were analyzed. When the initial water depth at the upper floor was 0.3 m, the maximum velocity at lower floor was 4.2 m/s, and the maximum momentum was $1.2m^3/s^2$, and its conversion to force per unit width was 1.2 kN/m. This value was equivalent to the hydrostatic force with 50 cm water depth, and evacuation became difficult, as proposed by Ishigaki et al. For the flow over staircases connecting two layers, the maximum run-up height in flat part connecting two layers was approximately two times higher than the initial water depth in upper floor, and the rapid shock wave with sharp front and long tail was propagated.

• International journal of advanced smart convergence
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• v.8 no.4
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• pp.75-81
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• 2019

Though recent advancement of deep learning methods have provided satisfactory results from large data domain, somehow yield poor performance on few-shot classification tasks. In order to train a model with strong performance, i.e. deep convolutional neural network, it depends heavily on huge dataset and the labeled classes of the dataset can be extremely humongous. The cost of human annotation and scarcity of the data among the classes have drastically limited the capability of current image classification model. On the contrary, humans are excellent in terms of learning or recognizing new unseen classes with merely small set of labeled examples. Few-shot learning aims to train a classification model with limited labeled samples to recognize new classes that have neverseen during training process. In this paper, we increase the backbone depth of the embedding network in orderto learn the variation between the intra-class. By increasing the network depth of the embedding module, we are able to achieve competitive performance due to the minimized intra-class variation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.3
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• pp.219-227
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• 2017

In pelagic longline, deploying the gear such that the depth of the hook is the same as that of the target fish is important to improve the fishing performance and selectivity. In this study, the depth of the tuna longline hook was estimated using the mass-spring model, catenary curve method, and secretariat of the pacific commission Pythagorean method in order to improve the performance of the longline gear in Fiji. The former two methods were estimated to be relatively accurate, and the latter showed a large error. Further, the mass-spring model accounted for the influence of tidal current in the ocean, which was found to be appropriate for use in field trials.

• Journal of the Korean Geotechnical Society
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• v.35 no.11
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• pp.37-49
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• 2019

In order to analyze the effect of burial depth on the generation of ground cavities and cave-ins, a series of model experiments with different height of model ground were performed. Digital images of the model ground were captured to evaluate the internal deformation of the model grounds by adopting the PIV (Particle Image Velocimetry) technique. Additionally, the vertical displacement at the surface, the size of the cavity, and the weight of the discharged soil were measured in each test. The results indicate that the model ground with low burial depth, which does not satisfy the criterion, was more vulnerable to ground cavities and cave-ins than the model ground with high burial depth.