• Journal of Digital Convergence
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• v.16 no.10
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• pp.453-463
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• 2018

This study investigated the effects of an Augmented Reality(AR) implemented book on flow of reading, interest in history, and acquisition of history knowledge. Perceptions of AR infused books were investigated as well. Researchers provided a history book implementing AR and the same book without any AR content respectively to an experiment group(n=15) and a control group(n=15) composed of $3^{rd}$ and $4^{th}$ grade elementary school children. Results indicate that AR implemented reading had a positive effect on the flow of reading and interest in history, but not on acquisition of history knowledge. Also, AR-based contents were attractive to learners due to its amusing characters, sound, realistic visual motions, and vivid three-dimensional effects. Lastly, students preferred amusing interesting characters, lengthier animations and subtitles, and AR that could be seen without holding smart devices for a long while.

• Journal of Acupuncture Research
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• v.32 no.2
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• pp.105-121
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• 2015

Objectives : The purpose of this study is to observe the effects of Sa-am acupuncture with tonifications of kidney and urinary bladder on radial pulse in healthy subjects. Methods : Sixty healthy subjects participated in this study, and were divided into a kidney tonifying acupuncture group(KI group), urinary bladder tonifying acupuncture group(BL group) and control group. Radial pulse was measured by 3 dimensional pulse imaging system(DMP-3000) before, immediately after, 30 minutes after, and 60 minutes after acupuncture at Cun, Guan, and Chi in each time. Results : 1. BL group exhibited significantly reduced T1 / T, T4 / T, T4 / (T-T4), T5 / T and increased(T-T4) / T compared to KI group. 2. BL group showed increase of radial augmentation index / heart rate(RAI / HR) in left Cun, H5, Ad / Ap in left Chi, H1, As / Ap in right Chi compared to KI group. BL group showed decrease of As / Ap, Aw / Ap in left Chi, H1, pulse depth, Ad / Ap in right Chi compared to KI group. 3. KI group showed increase of Aw / Ap, H1, H2, H4, pulse area in right Guan, pulse depth in right Chi compared to BL group. KI group showed decrease of RAI in left Cun, applied pressure, pulse depth in left Guan, Aw / Ap in right Chi compared to BL group. Conclusions : The effects of Sa-am acupuncture with tonifications of kidney and urinary bladder in healthy humans have been observed on various parameters. The parameters analysed in this study can be used to differentiate the effects of Sa-am acupuncture with tonifications of kidney and urinary bladder on radial pulse.

• Journal of the Korea Computer Graphics Society
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• v.16 no.4
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• pp.1-10
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• 2010

We present a method to reproduce in-between views from captured stereo images to control depth feeling that a user can perceive on a 3D display. The stereo images captured from a pair of cameras have a fixed viewpoint and a screen parallax which depend on the physical position and the distance between the cameras. In this paper, we produce stereo images of an intermediate viewpoint between two original cameras by a view interpolation on the input stereo images. Furthermore, the camera separation of the reproduced stereo images can be controlled by a linear interpolation coefficient used by the view interpolation. By using the proposed method, stereo images can be reproduced where the depth feeling and a three dimensional effect is suitable for the individual's eye separation or the characteristic of an application.

• The KSFM Journal of Fluid Machinery
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• v.13 no.1
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• pp.42-51
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• 2010

Many different types of fan have been applying to various industrial fields. Fan design methods are much different depending on the types of fan, operating conditions, and connecting parts at the inlet or exit of the fan etc. In this study, design methods for an axial-type suction fan are studied. This fan discharges the air in the relative static pressure of -285Pa to the atmosphere with the flow rate of $960m^3/min$. For three-dimensional blade design, three different design methods were applied, such as the free vortex method, the exponential method, and the cascade method. In the cascade method, the blade loading along the radial direction was obtained from the lift coefficient which was necessary to obtain the pressure rise on a fan rotor. This method is different from the free vortex and the exponential method which control the strength of the vortex. The fan performance prediction was conducted using the CFD with three different inlet ducts. The best fan performance was obtained when the fan was designed by using the cascade method. The designed fan using the exponential method showed better performance compared to a fan designed using the free vortex method. However, the fan performance was changed depending on the installed inlet ducts. So, an efficient fan can be designed with the adjustment of design variables on the basis of the flow structures within the fan as well as the fan design procedure.

• Journal of Technologic Dentistry
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• v.42 no.3
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• pp.202-207
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• 2020

Purpose: This study is a comparative analysis of the strain according to deposition in a constant temperature water bath after manufacturing ultraviolet (UV)-cured artificial teeth. Methods: As a control group, 10 ready-made artificial teeth were selected as the first molar on the right side of the maxilla (RT group). Silicone was used as a duplicate of the artificial denture teeth. Experimental teeth were prepared in two groups using the prepared silicone mold. In the first experimental group, the UV-cured resin was injected into the negative silicone, followed by irradiation with a UV-curing machine for 5 minutes (5M group). In the second experimental group, the UV-cured resin was injected into the negative silicone, and then irradiated for 30 minutes using a UV-curing machine (30M group). The one-way ANOVA was performed, and post-test was analyzed by Tukey. Results: When immersed in a water bath for 15 days, it was found to be -0.3% in the RT group, -0.6% in the 5M group, and -0.7% in the 30M group. The results revealed -0.2% in the RT group, 0.2% in the 5M group, and -0.2% in the 30M group when they were in the bath for 30 days. Conclusion: In the water bath, the swelling was greater when deposited for 1 to 15 days, but was less when deposited for 15 to 30 days.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.10
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• pp.1175-1184
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• 2008

Delay-sum back projection(DSBP) algorithm and the time reversal algorithm based on the finite-difference time-domain method are compared. The two algorithms, which operate in the time domain, can process the ultra-wideband (UWB) radar data to generate images that are close to the original location and shape of the target. For the experiment, the UWB radar consists of a network analyzer, a resistive V dipole antenna, a scanner, and a control computer. The radar aperture is synthesized by linearly scanning the antenna. A calibration procedure is applied to the measured data to remove signal distortion and clutter. The two algorithms are applied to the same data on the same platform. It is shown that the DSBP algorithm produces better images but takes longer time to produce the images than the FDTD-TR algorithm.

• The korean journal of orthodontics
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• v.46 no.5
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• pp.269-279
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• 2016

Objective: Rapid maxillary expansion (RME) is used to expand the maxilla and increase arch perimeter; yet, there are few reports on its effects on the sphenoid bone. With cone-beam computed topography (CBCT), it is possible to visualize sphenoid bone changes. The purpose of this study was to investigate sphenoid bone changes observed in conjunction with RME treatments, using CBCT. Methods: Sixty patients (34 women and 26 men, aged 11-17 years) underwent RME as part of their orthodontic treatment. Patients were randomly assigned to one of three groups: a tooth-anchored group, a bone-anchored group, or a control group. Initial CBCT scans were performed preceding the RME treatment ($T_1$) and again directly after the completion of expansion ($T_2$). Statistical analysis included ANOVA, descriptive statistics, and the intraclass correlation coefficient (ICC). Results: The reliability of the landmark location was at least 0.783, and the largest ICC mean measurement error was 2.32 mm. With regard to distances, the largest change was 0.78 mm, which was not statistically significant (p > 0.05). Statistical significance was established in patient groups of the same sex and treatment type for the following distance measurements: right anterior lateral pterygoid plate to the right edge of the hypophyseal fossa ($d_2$), anterior distance between the medial pterygoid plates ($d_4$), and anterior distance between the left medial and lateral plates ($d_8$). Conclusions: In this study, there were no clinically significant changes in the sphenoid bone due to RME treatments regardless of sex or treatment type.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.5
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• pp.639-645
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• 2012

In this paper, we propose a method that gives motion command to a mobile robot to recognize human being's hand gesture. Former way of the robot-controlling system with the movement of hand used several kinds of pre-arranged gesture, therefore the ordering motion was unnatural. Also it forced people to study the pre-arranged gesture, making it more inconvenient. To solve this problem, there are many researches going on trying to figure out another way to make the machine to recognize the movement of the hand. In this paper, we used third-dimensional camera to obtain the color and depth data, which can be used to search the human hand and recognize its movement based on it. We used HMM method to make the proposed system to perceive the movement, then the observed data transfers to the robot making it to move at the direction where we want it to be.

• Journal of Hydrogen and New Energy
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• v.27 no.6
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• pp.764-772
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• 2016

This paper presents on the evaluation of numerical analysis model of a ball valve used for a gas pipeline. The ball valve has important role to control the gas flow of the pipeline as well as safety operation to prevent gas explosion at the emergency. For the validation of numerical simulation, the computational domains are introduced three different types: a hexahedron chamber connected to a pipeline outlet without considering the geometry of pressure tubes, a pipeline only considered the geometry of pressure tubes, and a pipeline connected both of the a hexahedron chamber and pressure tubes. The commercial code, SC/Tetra, is introduced to solve the three-dimensional steady-state Reynolds-averaged Navier-Stokes analysis in the present study. The valve flow coefficient and valve loss coefficient with respect to the valve opening rate of 30%, 50%, and 70% are compared with experimental results. Throughout the numerical analysis for the three analysis domains, pressure computed along the pipeline is affected by computational domains. It is noted pressure obtained by the computational model considering both of the a hexahedron chamber and pressure tubes has a relatively good agreement to the experimental data.

• Journal of Information Technology and Architecture
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• v.10 no.3
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• pp.347-359
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• 2013

The quality control of data is important element in data usage activations and decision makings. This paper is on how to extract the major critical data by each institution or organization selves. It proposes a social network analysis as a way to extract a table of high influence degree from a dynamic meta-data. The proposed CTQ data extraction method using SNA proved the fact that it is possible to extract highly accurate CTQ data by scientific measures of three-dimensional approach to real business situations without professional technicians. It is a new way that will change the goings on CTQ data management in IT sector and will improve the quality management level of an organization when applied to the real world.