• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.4
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• pp.295-304
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• 2012

This study proposed a two-dimensional horizontal numerical model based on the nonlinear shallow water wave equations to simulate tsunami propagation and coastal inundation. We numerically investigated the possible impacts of tsunami caused by the triple interlocked Tokai, Tonankai and Nankai Earthquakes on the Jeju coastal areas, using the proposed model. The simultaneous Tokai, Tonankai and Nankai Earthquakes were created a virtual tsunami model of an M9.0 earthquake. In numerical analysis, a grid nesting method for the local grid refinement in shallow coastal regions was employed to sufficiently reproduce the shoaling effects. The numerical model was carefully validated through comparisons with the data collected during the tsunami events by 2011 East Japan Earthquake and 1983 central East Sea Earthquake (Nihonkai Chubu Earthquake). Tsunami propagation triggered by the combined Tokai, Tonanakai and Nankai, Earthquakes was simulated for 10 hours to sufficiently consider the effects of tsunami in the coastal areas of Jeju Island. The numerical results revealed that water level fluctuation in tsunami propagation is greatly influenced by water-depth change, refraction, diffraction and reflection. In addition, the maximum tsunami height numerically estimated in the coastal areas of Jeju Island was about 1.6 m at Sagye port.

• Science of Emotion and Sensibility
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• v.14 no.1
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• pp.27-38
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• 2011

This study was aimed to investigate the effects of restaurant in-store color and music congruency on consumer's emotional responses and behavioral intentions. The web survey was conducted among 400 customers(aged from 20~39 years old) who lived in Seoul and Kyunggi, Incheon Province. To find ensemble effect of color and music, 3D studio MAX were used to make high-stimulus(exciting) and low-stimulus(calm) and 3D virtual reality restaurant simulation stimulus were applied. The statistical data analyses were performed using SPSS/WIN 18.0 and reliability analysis, factor analysis, regression analysis were used. Based on the result of the conducting factor analysis, emotional responses were classified into 2 factors: positive emotion and negative emotion. Satisfaction was classified into 1 factor: satisfaction. Loyalty was classified into 1 factor: loyalty. Cronbach's alpha was calculated for the reliability of the survey instrument. Consequently, restaurant in-store color and music congruency were shown to affect positive emotion and negative emotion. Positive emotion and negative emotion were shown to affect satisfaction. Satisfaction were shown to affect loyalty. Music congruency had a higher effect on positive emotion than color congruency. Color congruency had a higher effect on negative emotion than music congruency. The results of this study will serve as a basis of color and music congruency with restaurant atmospherics.

• The Journal of the Korea Contents Association
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• v.8 no.8
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• pp.128-146
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• 2008

Cyworld has created a new social phenomenon that relationship between people and communities could be built by committing to digital writing. It has altered the way of people's writing attitudes from self-confessed to self-describing and self-broadcasting ways in which one regards oneself as the center of the cyber world. The purpose of this paper is to identify the shift in one's writing attitudes and how he/she develops technologies of the self in the Cyworld space. Quantitative and qualitative methods support the result; The analysis of 100 Cyworld users' mini-homepages show how the visual images in Cyworld affects their way of digital writing and the analysis of the change of writing habit due to sharing data how virtual 'family' that has been created by Cyworld. I categorize the characteristics of digital writing into three; 1)Visualization of technologies of the self 2)Networked technologies of the self 3)Sharing secretes. The aim of writing in Cyworld is not to keep the secrete but to share and, eventually, texts are circulated in the networked society where one is participated(Cyworld family). Therefore, the usage of images plays a significant role in Cyworld communities because the opened secretes are usually prepared to be presented on the basis of trustworthy toward other members.

• Journal of the Institute of Convergence Signal Processing
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• v.20 no.4
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• pp.238-244
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• 2019

In this study, we compared and analyzed the performance of each Convolution Neural Network (CNN) by implementing the CNN that reflected the characteristics of the cerebral structure, in order to analyze the CNN that was used for the prediction of cybersickness, and provided the performance varying depending on characteristics of the brain. Dizziness has many causes, but the most severe symptoms are considered attributable to vestibular dysfunction associated with the brain. Brain waves serve as indicators showing the state of brain activities, and tend to exhibit differences depending on external stimulation and cerebral activities. Changes in brain waves being caused by external stimuli and cerebral activities have been proved by many studies and experiments, including the thesis of Martijn E. Wokke, Tony Ro, published in 2019. Based on such correlation, we analyzed brain wave data collected from dizziness-inducing environments and implemented the dizziness predictive artificial neural network reflecting characteristics of the cerebral structure. The results of this study are expected to provide a basis for achieving optimal performance of the CNN used in the prediction of dizziness, and for predicting and preventing the occurrence of dizziness under various virtual reality (VR) environments.

• Molecules and Cells
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• v.38 no.4
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• pp.373-379
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• 2015

Pyruvate kinase M2 isoform (PKM2), a rate-limiting enzyme in the final step of glycolysis, is known to be associated with the metabolic rewiring of cancer cells, and considered an important cancer therapeutic target. Herein, we report a novel PKM2 activator, PA-12, which was identified via the molecular docking-based virtual screening. We demonstrate that PA-12 stimulates the pyruvate kinase activity of recombinant PKM2 in vitro, with a half-maximal activity concentration of $4.92{\mu}M$, and effectively suppresses both anchorage-dependent and -independent growth of lung cancer cells in non-essential amino acid-depleted medium. In addition, PA-12 blocked the nuclear translocalization of PKM2 in lung cancer cells, resulting in the inhibition of hypoxia response element (HRE)-mediated reporter activity as well as hypoxia-inducible factor 1 (HIF-1) target gene expression, eventually leading to the suppression of cell viability under hypoxia. We also verified that the effects of PA-12 were dependent on PKM2 expression in cancer cells, demonstrating the specificity of PA-12 for PKM2 protein. Taken together, our data suggest that PA-12 is a novel and potent PKM2 activator that has therapeutic implications for lung cancer.

• Imaging Science in Dentistry
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• v.42 no.3
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• pp.139-146
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• 2012

Purpose: An individual surgical stent fabricated from computed tomography (CT) data, called a CT-guided stent, would be useful for accurate installation of implants. The purpose of the present study was to introduce a newly developed CT-guided stent with a simple design and evaluate the accuracy of the stent placement. Materials and Methods: A resin template was fabricated from a hog mandible and a specially designed plastic plate, with 4 metal balls inserted in it for radiographic recognition, was attached to the occlusal surface of the template. With the surgical stent applied, CT images were taken, and virtual implants were placed using software. The spatial positions of the virtually positioned implants were acquired and implant guiding holes were drilled into the surgical stent using a specially designed 5-axis drilling machine. The surgical stent was placed on the mandible and CT images were taken again. The discrepancy between the central axis of the drilled holes on the second CT images and the virtually installed implants on the first CT images was evaluated. Results: The deviation of the entry point and angulation of the central axis in the reference plane were $0.47{\pm}0.27$ mm, $0.57{\pm}0.23$ mm, and $0.64{\pm}0.16^{\circ}$, $0.57{\pm}0.15^{\circ}$, respectively. However, for the two different angulations in each group, the $20^{\circ}$ angulation showed a greater error in the deviation of the entry point than did the $10^{\circ}$ angulation. Conclusion: The CT-guided template proposed in this study was highly accurate. It could replace existing implant guide systems to reduce costs and effort.

• Journal of the Korea Society of Computer and Information
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• v.18 no.2
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• pp.117-126
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• 2013

Path planning is an essential problem to make virtual characters navigate in many applications including computer games. In many cases, multiple characters move in a group and qualitative aspects of planned paths are emphasized rather than optimality unlike Robotics. In this paper, we propose a two-level path planning algorithm in which the global path is planned for a single character specified as a leader and then the local path is planned to avoid dynamic obstacles while the group following this path. The space for group movement is achieved in the form of square grid array called a grid window. Member characters are located relatively to the leader within a space and moved. The static environment is reduced to the configuration space of this grid window to generate a roadmap on which a grid window can move. In local path planning, only the leader avoids dynamic obstacles by using an artificial potential field and the rest of members are located relatively to the leader in the grid window, which reduces computational load. Efficient algorithms to implement the proposed planning methods are introduced. The simulation results show that a group can handle with dynamic obstacles effectively while moving along the planned path for a static environment.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.6
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• pp.741-747
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• 2009

For construction of 3D virtual city models, airborne digital cameras, laser scanners, multi-oblique photograph systems and other devices are currently being used. With such advanced techniques, precise 3D spatial information can be collected and high quality 3D city models can be built in a considerably large area. The 3D spatial information to be built has to provide the latest information that quickly reflects the causes of any change due to urban development. In this study, a UAV photogrammetric method using low cost UAV and digital camera was proposed to acquire and update 3D spatial information effectively on small areas where information continuously change. In the proposed UAV photogrammetric method, the elements of interior orientation were acquired through camera calibration and the vertical and oblique photographs were taken at 9 points and the 3D drawing of ground control points and buildings was performed using 20 images among the pictured images. This study also analyzed the accuracy of the proposed method comparing with ground survey data and digital map in order to examine whether the method can be used in on-demand 3D spatial information update on relatively small areas.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.3
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• pp.259-267
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• 2020

For real-time precise positioning, N-RTK (Network Real-Time Kinematic) technology is widely used these days. However, the currently operating N-RTK system has a limitation in terms of the number of users. Therefore, if reference points generate correction messages with no limit on the number of users are developed later, it is determined that an appropriate reference point installation interval is required, so that the accuracy of the N-RTK system according to the baseline distance was analyzed. This experiment utilized receivers with varying performance that estimated the rover position, and RTKLIB, an open-source software, is used for processing data. As a result, the rover position was estimated accurately with a high rate of fixed ambiguity for all the receivers. When the reference station with a baseline length of 40 km was used, the vertical RMSE (Root Mean Squared Error) was quite similar to the short baseline case, but only half of the ambiguity fixing rate was achieved. The outlier in the estimated rover position was not observed for the longer baselines in the case of a high-end receiver. It is necessary to analyze the ambiguity fixing and the accuracy of the kinematic positioning with scientific GNSS processing software.

• Applied Microscopy
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• v.36 no.1
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• pp.7-16
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• 2006

A new remote access system for a 1.3 MV high voltage electron microscope has been developed. Almost all essential functions for HVEM operation, huck as stage control, specimen tilting, TV camera selection and image recording, are successfully embedded into this prototype of the remote system. Particularly, this system permits perfect and precise operation of the goniometer and also controls the high resolution digital camera via simple Web browsers. Transmission of control signals and communication with the microscope is accomplished via the global ring network for advanced applications development (GLORIAD). This fact makes it possible to realize virtual laboratory to carry out practical national and international HVEM collaboration by using the present system