• Journal of the Korea Society of Computer and Information
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• v.21 no.12
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• pp.11-18
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• 2016

Magnetic resonance image (MRI) is widely used in brain research field and medical image. Especially, non-invasive brain activation acquired image technique, which is functional magnetic resonance image (fMRI) is used in brain study. In this study, we investigate brain activation occurred by LED light stimulation. For investigate of brain activation in experimental small animal, we used high magnetic field 9.4T MRI. Experimental small animal is Balb/c mouse, method of fMRI is using echo planar image (EPI). EPI method spend more less time than any other MRI method. For this reason, however, EPI data has low contrast. Due to the low contrast, image pre-processing is very hard and inaccuracy. In this study, we planned the study protocol, which is called block design in fMRI research field. The block designed has 8 LED light stimulation session and 8 rest session. All block is consist of 6 EPI images and acquired 1 slice of EPI image is 16 second. During the light session, we occurred LED light stimulation for 1 minutes 36 seconds. During the rest session, we do not occurred light stimulation and remain the light off state for 1 minutes 36 seconds. This session repeat the all over the EPI scan time, so the total spend time of EPI scan has almost 26 minutes. After acquired EPI data, we performed the analysis of this image data. In this study, we analysis of EPI data using statistical parametric map (SPM) software and performed image pre-processing such as realignment, co-registration, normalization, smoothing of EPI data. The pre-processing of fMRI data have to segmented using this software. However this method has 3 different method which is Gaussian nonparametric, warped modulate, and tissue probability map. In this study we performed the this 3 different method and compared how they can change the result of fMRI analysis results. The result of this study show that LED light stimulation was activate superior colliculus region in mouse brain. And the most higher activated value of segmentation method was using tissue probability map. this study may help to improve brain activation study using EPI and SPM analysis.

• International Journal of Automotive Technology
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• v.7 no.4
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• pp.477-483
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• 2006

A vibration model of a helical gear pair for vehicle transmission is developed by considering the elastic deformation of the active teeth and the body to be a rigid. The main source of vibration in a helical gear system which caused by the mass unbalances of rotors and the transmission errors of gearings in mathematically formulated and applied to the analysis of vibration characteristics of geared systems. As an example, a simple geared system containing a helical gearing is considered. The critical speeds are found by the Campbell diagram and compared with the experimental results We expect this developed program to contribute to the reduction of the vibration and noise on vehicle a transmission in the field of both design and manufacturing. In addition, this program can be used as a basic program for CAD/CAM of low-noised gear teeth.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1024-1026
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• 2002

The active power filter(APF) is a good solution for elimination of harmonics, which is produced by the nonlinear loads such as static power converter, computer and so on. Our trademark of APF is a POSAPF-series, which was applied to Samsung Electronics corp, in January 2002, and which lines up from 50A to 500A. This equipment reduces total demanded distortion (TDD) by 2${\sim}$3%, which originally 11${\sim}$13%. This paper discusses the harmonic regulation, measurement and analysis, and describes control theories and design methods of POSAPF-series, and, finally, shows the experimental results of a real system.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.382-399
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• 2011

Impact factor of concrete and ballast track which has been used in Korea railway was applied to equation (1+0.513V/100) from AREA. As the use of this equation, overcapacity of track design might be occurred. Therefore, this study compared impact of ballast track (well, bad) and concrete track (sleeper embeded system, rail floating and sleeper floating) by field test to analyzing dynamic effect of track structure's characteristic and wheel load on service line. In addition, it suggested a method to generate reasonable track impact factor on each track type.

• The Research Journal of the Costume Culture
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• v.19 no.2
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• pp.316-323
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• 2011

This research aim concerns questioning how we can generate environments suggestive of nature fused with built environments through textiles. Through literature reviews and experiments with available the 3D imaging techniques of Holography, Lenticular and other new technologies. We also have researched towards finding the most effective method for 3D imaging techniques for textile applications. The advantage of the combining technique is to create the possibility of seeing a number of different floating 3D illusory images, depending on the viewing angle. This objective is to produce intriguing textile patterns and images in which the objects and colours change as viewpoints change. Experimental work was carried out in collaboration with professional textile researchers, scientists, artists and designers conducting research in this field.

• The Journal of Korean Physical Therapy
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• v.30 no.4
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• pp.112-116
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• 2018

Purpose: This study aimed to identify the effects of a task-oriented exercise program on balance in patients with acute stroke. Methods: Twenty participants with hemiparesis resulting from acute stroke volunteered to participate in this study. They were randomly assigned to either the experimental or control group, with 10 patients per group. Both groups underwent a task-oriented exercise program averaging 30 minutes daily for 4 weeks. Balance was assessed before and after the 4-week training period. Before and after the intervention, we conducted a paired t-test to compare the within-group changes and an independent t-test to compare the between-group differences. The statistical significance level was set at p=0.05 for all the variables. Results: Both groups showed significant within-group and between-group changes in balance (p<0.05) after the intervention. Conclusion: This study provides valuable information for future studies in this field. Further research using a larger sample and longer experiment spans can corroborate the results of our study.

• Transactions of Materials Processing
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• v.3 no.1
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• pp.23-37
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• 1994

The upper bound element technique(UBET) is used to analyze the final stage of the axisymmetric forward extrusion. Kinematically admissible velocity field involving curved surface of velocity discontinuity is assumed. The required power to arise the piping defect is obtained and is compared with Aviture's solution a the same condition. Conditions for inception of the cavity and development of the pipe are predicted. The internal radius of the pipe and critical length of billet are also determined. Experiments are carried out for extrusion with lead specimens to investigate the piping phenomena. The theoretically predicted results showed reasonably good agreement with the experimental observation.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.1014-1019
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• 2001

A numerical investigation was performed to determine the effect of airfoil on the optimum flap height using NACA 00XX and 44XX airfoils. The six flaps which have 0.5% chord height difference were selected. A Navier-Stokes code, FLUENT, was used to calculate the flow field of the airfoil. The code was first tested as a benchmark by modelling flow around a NACA 4412 airfoil. Predictions of local pressure coefficients are found to be in good agreement with the result of the experimental result. For every NACA 00XX and 44XX airfoil, flap heights ranging from 0.0% to 2.5% chord were changed by 0.5% chord interval and their effects were also studied. Representative results from each case are presented graphically and discussed. It is concluded that this initial approach gives an idea for the future development of the wind turbine optimum design.

• The Research Journal of the Costume Culture
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• v.8 no.2
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• pp.315-333
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• 2000

The purpose of this study is to find out how the aesthetic values and characters of the Avant-garde fashion through semantics analysis of Avant-garde experiments in the early 20th century. Inner expressions of Avant-garde fashion in future dynamism, alien-hostile, and surreal-experimentalism are as followings (1) Reject tradition of existing fashion concept, (2) Dismantle costume material and inter-text characteristics in fashion field, (3) Laugh at material civilization and elite fashion, (4) Pursue primitive and fundamental sensibility on non-civilized world (5) Express human estrangement due to material civilization, (6) Remove the barrier of fashion between luxury and cheap ones, (7) Time, space and purpose is mixed, (8) Open concept as space structure independent of human body, (9) Complicatedness, ambiguity and expression of irregularity as changeableness, (10) Dismantle concept of beauty and ugliness. As you see, fashion design in modern Avan-garde is pursuing newness as beauty of open concept, rejecting all modern tradition and allowing extremity such as experimental, illogic, unreasonable and non-formatted expressions.

• Journal of the Korea Computer Industry Society
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• v.8 no.1
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• pp.57-64
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• 2007

In the paper, considers the design of a detection system, consisting of n identical detectors, to process the sum of spatially invariant signal fields $S_\jmath(t)$, an additive, homogeneous, spatially isotropic (in the array plane x). covariance_separable, and zero_mean Gaussian random noise field n(t, x). consisting of arrey receivers for use in optical communication through optimum turbulence atmosphers and covriance_circuit, staistical analysis through detection the maximum gain are compared with analysis theoretical analysis theoretical value and get through experimental measured value, as well the measured valus are confirmed to agreement joint Gaussian theoretical curves.