• Ocean and Polar Research
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• v.42 no.3
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• pp.211-223
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• 2020

With the increasing demand for improved marine environments and safety, greater ability to minimize damages to coastal areas from harmful organisms, ship accidents, oil spills, etc. is required. In this regard, an accurate assessment and understanding of current systems is a crucial step to improve forecasting ability. In this study, we examine spatial and temporal characteristics of current systems in the adjacent seas of Jeju Island using a high-resolution regional ocean circulation model. Our model successfully captures the features of tides and tidal currents observed around Jeju Island. The tide form number calculated from the model result ranges between 0.3 and 0.45 in the adjacent seas of Jeju Island, indicating that the dominant type of tides is a combination of diurnal and semidiurnal, but predominantly semidiurnal. The spatial pattern of tidal current ellipses show that the tidal currents oscillate in a northwest-southeast direction and the rotating direction is clockwise in the adjacent seas of Jeju Island and counterclockwise in the Jeju Strait. Compared to the mean kinetic energy, the contribution of tidal current energy prevails the most parts of the region, but largely decreases in the eastern seas of Jeju Island where the Tsushima Warm Current is dominant. In addition, a Lagrangian particle-tracking experiment conducted suggests that particle trajectories in tidal currents flowing along the coast may differ substantially from the mean current direction. Thus, improving our understanding of tidal currents is essential to forecast the transport of marine pollution and harmful organisms in the adjacent seas of Jeju Island.

• Tunnel and Underground Space
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• v.26 no.6
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• pp.493-507
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• 2016

Scaled model tests were performed to investigate the stability of a foundation located above limestone cavities. Cavity shape was assumed to be an ellipse having 1/3 for the ratio of minor to major axis lengths. 12 different test models which have various depths, locations, inclinations, sizes and numbers of cavity were experimented and they were classified into 5 different groups. Crack initiation pressure, maximum pressure, deformation behaviors, failure modes and subsidence profiles of test models were obtained, and then the influences of those parameters on the foundation stability were investigated. No cavity model showed a general shear failure, whereas the models including various cavities showed the complicated three different failure modes which were only punching failure, both punching and shear failures, and double shear failure. The stability of foundation was found to be decreased as the cavity was located at shallower depth, the size and number of cavity were increased. Differential settlements appeared when the cavity was located under the biased part of foundation. Furthermore, subsidence profiles were found to depend on the distribution of underground cavities.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.8
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• pp.1976-1995
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• 2023

The anchor-free object detector CenterNet regards the object as a center point and predicts it based on the Gaussian circle region. For each object's center point, CenterNet directly regresses the width and height of the objects and finally gets the boundary range of the objects. However, the critical range of the object's center point can not be accurately limited by using the Gaussian circle region to constrain the prediction region, resulting in many low-quality centers' predicted values. In addition, because of the large difference between the width and height of different objects, directly regressing the width and height will make the model difficult to converge and lose the intrinsic relationship between them, thereby reducing the stability and consistency of accuracy. For these problems, we proposed a center point prediction method based on the Gaussian elliptic region and a size component regression method based on the small solution space. First, we constructed a Gaussian ellipse region that can accurately predict the object's center point. Second, we recode the width and height of the objects, which significantly reduces the regression solution space and improves the convergence speed of the model. Finally, we jointly decode the predicted components, enhancing the internal relationship between the size components and improving the accuracy consistency. Experiments show that when using CenterNet as the improved baseline and Hourglass-104 as the backbone, on the MS COCO dataset, our improved model achieved 44.7%, which is 2.6% higher than the baseline.

• Food Science and Preservation
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• v.8 no.2
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• pp.146-150
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• 2001

The candy was prepared from starch syrup and sugar added with puree, extract and powder of Doraji, respectively. When three times extracted with 95% ethanol for 12 hours at $25^{\circ}C$ and 4 hours at 51$^{\circ}C$ and 78$^{\circ}C$, the extract contents were 22.6%, 25.8% and 25.3%, respectively. L-value of candy which was made of puree and extract of Doraji was lower than that of control. As the content of puree and extract of Doraji is increased, L-value was decreased. In case of added with puree, extract and powder, a and b-values were higher than those of control. Quality of the candy in sensory evaluation was the best when 20% of puree, 2% of extract and 5% of powder were added to the starch syrup and sugar, respectively. The result of preference test with various model, Bokjumony (Korea traditional purse) was the best in eye freel and ellipse was the best in mouth feel. The calories of candy were 2999.6 ㎉/100g in puree 20%, 358.3 ㎉/100g in extract 2% and 352.1 ㎉/100g in powder 5%.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.4
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• pp.309-318
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• 2001

In this paper, we describe methods that analyze a human gesture. A human interface(HI) system for analyzing gesture extracts the head and hand regions after taking image sequence of and operators continuous behavior using CCD cameras. As gestures are accomplished with operators head and hands motion, we extract the head and hand regions to analyze gestures and calculate geometrical information of extracted skin regions. The analysis of head motion is possible by obtaining the face direction. We assume that head is ellipsoid with 3D coordinates to locate the face features likes eyes, nose and mouth on its surface. If was know the center of feature points, the angle of the center in the ellipsoid is the direction of the face. The hand region obtained from preprocessing is able to include hands as well as arms. For extracting only the hand region from preprocessing, we should find the wrist line to divide the hand and arm regions. After distinguishing the hand region by the wrist line, we model the hand region as an ellipse for the analysis of hand data. Also, the finger part is represented as a long and narrow shape. We extract hand information such as size, position, and shape.

• Geomechanics and Engineering
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• v.28 no.5
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• pp.493-503
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• 2022

Cavity expansion is a classical problem in the field of solid mechanics with a wide range of applications in geotechnical and petroleum engineering. A drained solution is developed for cylindrical cavity expansion in anisotropic soils under biaxial in-situ stresses using a K0-based anisotropic modified Cam-clay model (K0-AMCC). The problem is formulated by solving differential equations using an auxiliary variable, which provides analytical expressions for the volume and four stress components of the soil around the cylindrical cavity. The solution is validated by comparisons with existing well-developed solutions. The results show that the present solution well captures the cavity expansion responses in anisotropic soils under biaxial in-situ stresses, and removes limiting assumptions that the cylindrical cavity expands under uniform in-situ stress in isotropic soils. The elastic-plastic boundary of the expanding cylindrical cavity in K0-consolidated anisotropic soils under biaxial in-situ stresses is a circle rather than an ellipse in isotropic soils, and the mathematical proof is provided in detail.

• Journal of the Korean Society for Railway
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• v.13 no.3
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• pp.339-348
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• 2010

The government continues to make efforts to improve effectiveness, integration and connectivity of public transportation systems. But there have been only a few studies about it. This paper addresses the quality evaluation of pedestrian facility service in transfer stations at urban railroad. LOS (Level Of Service) model of urban railroad by facility based on the body ellipse and density recalculated considering the recent Korean body standard and the suggested Pedestrian Moving Equivalent (PME) and Pedestrian Waiting Equivalent (PWE). For LOS model for the ticket booths and ticket vending machines, queuing theory has been applied to determine LOS of Pedestrians. And the importance weights among the pedestrian facilities is obtained by applying AHP analysis. Lastly, this paper shows and discusses the evaluation results of overall LOS of pedestrian facilities of five urban railroad transfer stations in Seoul.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.1
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• pp.37-46
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• 2004

In order to increase fishing efficiencies of the fyke net used in the coast of Jeju Island, water tank experiment was caried out entering and escaping behavior using nets that were reduced to 1/20 of the size of the full scale fyke net and were improved to have antrance structure, and mackerel Scomber japonicus as experimental fish. The results of measurement are as follows : 1. Fish school behavior in the main net was showed two different patterns : swimming in a circle in the right space of the main net and swimming back and forth in ellipse in the right and left space. 2. The swimming speed of mackerel school was 23.9. 12.6 and 32.0cm/sec in the center space, right space of main net and in the mouth 3. The entering rate of fish school was 40% in net with 35cm length of the upper and funnel net in the mouth of fyke model net and 49% in conventional type fyke model net. 4. The escaping rate of fish school was 10% in net with 35cm length of the upper and funnel net in the mouth of fyke model net and 69% in conventional type fyke model net. 5. The remain rate of fish school was 90% in net with 35cm length of the upper and funnel net in the mouth of fyke model net and 31% in conventional type fyke model net.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6B
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• pp.531-539
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• 2011

It has been widely acknowledged that climate system associated with extreme rainfall events was difficult to understand and extreme rainfall simulation in climate model was more difficult. This study developed a new model for extracting rainfall filed associated with extreme events as a way to characterize large scale climate system. Main interests are to derive location, size and direction of the rainfall field and this study developed an algorithm to extract the above characteristics from global climate data set. This study mainly utilized specific humidity and wind vectors driven by NCEP reanalysis data to define the rainfall field. Geometric first and second moments have been extensively employed in defining the rainfall field in selected zone, and an ellipsoid based model were finally introduced. The proposed geometric moments based ellipsoid model works equally well with regularly and irregularly distributed synthetic grid data. Finally, the proposed model was applied to space-time real rainfall filed. It was found that location, size and direction of the rainfall field was successfully extracted.

• Journal of the Society of Naval Architects of Korea
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• v.37 no.2
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• pp.70-76
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• 2000

A numerical study on the viscous flow around a 2-dimensional circulation control foil is carried out for application on the field of naval architecture and ocean engineering. The governing equations are the RANS and the continuity equations. The equations are discretized by finite difference method and MAC method and the pressure poisson equation is calculate by a SOR method and an O-type non-staggered boundary fitted coordinate system which is overlapped near the slot is used to improve the numerical accuracy. Turbulence is approximated by a modified Baldwin-Lomax turbulence model. In the present paper, the Coanda effect on a 2-dimensional foil of a 20% thickness ellipse with modified rounded trailing edge has been numerically studied. The change in drag and lift of the foil with various jet momentums are calculated and compared to the experimental results to show good agreements.