• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.18-21
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• 2021

This paper analyzes the distortion correction of the in the micro DMD(digital micro mirror device) projector system using 0.25 or less optical throwing distance ratio. The distortion of projected image occurs depending on the performance of the optical lens, the installation location of the projection system, and the tilt of the screen. This study analyzed the physical tilt values influencing of the distortion of projected image, removed the tilt distortion of throwing distance ratio optical lens, and adjusted the distortion image by the simulation of calibration displacements. The results of this study demonstrated within 5% TV distortion reference. Moreover, the correction method reduced the pin-distortion correction of projection system.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.15-16
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• 2012

The estimation of crack damages is studied using the radio frequency system and tilt switch sensors in RC beams. If load is received on the center of the flexible specimen, sensor housing using cement mortar of the flexible specimen will be destroyed, and these are become to send signals of damages at the radio frequency system connected with tilt switch sensors. This study is fundamental research for the estimation of the damage using tilt switch sensors in RC beams.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1031-1032
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• 2007

Gap servo NF (Near Field) system is one of technologies to reduce beam spot size by increasing NA (Numerical Aperture) of lens. To achieve higher NA, SIL (Solid Immersion Lens) is used. In the case of using a blue LD (405 nm) as the light source the gap distance should be controlled under 100 nm with much tighter margin. Because of very small gap distance between SIL bottom and the surface of media, relative tilt tolerance is limited. In this paper, we presented 2-axis tilt mechanism for skew adjustment within small tilt margin.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.561-564
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• 1998

This paper evaluated autonomic nervous system function in 23 patients with syncope and a positive tilt test result, 21 with a negative test result, and 19 healthy controls. Indexes of heart rate variability were measured during supine resting, immediately afte rtilt-up, standing rsting, immediately before syncope and immediately after tiltdown. There were no significant differences among the groups in any of the indexes of heart rate varability over the 24-hour holter recordings. In patients with a positive tilt result, tilting gaused a decrease in low-frequency (LF) immediately before syncope and incsrease in high-frequency (HF) bands immediately before. In patients with a negative tilt result, tilting caused a decrease in low-frequency (LF) immediately before syncope and decrease in high-frequency (HF) bands immediately before, different from positive tilt results. Our findings showed that patients with vasovagal syncope have no chronic differences from normal subjects in autonomic nervous system activity, but that these patients respond differently to the orthostatic stimulus.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.2
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• pp.103-110
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• 2001

To reduce the traffic congestion and parking problems in urban areas tall and narrow vehicles have interested as a means to increase the utilization of existing freeways and parking facilities. The stability problem for those narrow vehicles which might be caused can be reduced by tilting the body toward the inside of the turn. The Direct Tilt Control(DTC) system and the Steering Tilt Control(STC) system have been proposed for those narrow vehicles. In this paper, as one of the performance improvement for that kind of vehicle a new control system to use the merits of both the DTC system and the STC system is proposed. Because two different control systems fight each other, the switching control scheme is applied as a means to prevent fighting. Also, the method in order to achieve the smoothly changed control system when the system is switched from the DTC to the STC or from the STC to the DTC, the appropriate type of control gain is designed.

• Journal of Korean Physical Therapy Science
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• v.7 no.2
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• pp.579-595
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• 2000

The purposes of this study were to compare pelvic tilt before and after manipulation of sacroiliac joint in 31 low back pain patients (11 males, 20 females) with sacroiliac joint dysfunction. The sacroiliac joint of patients was manipulated on the side of anterior pelvic tilt, using the technique described by Stoddard (1962) and Greenmann (1996). I used this technique because it usually eliminated sacroiliac joint dysfunction in one treatment session. SPSS for window computer system was used to analyze the data. Also t-test was performed for comparison of pelvic tilt angle before and after manipulation, and Pearson product-moment correlation analysis was performed for intratester reliability for measurements of pelvic tilt angle before and after manipulation. The result were as follows: 1. Intratester reliability was good for measures of pelvic tilt (r=.98). 2. The pelvic tilt after manipulation was significantly decreased (mean=$3.40^{\circ}$) compared with the pelvic tilt before manipulation (p=.001). All subjects showed asymmetrical right versus left pelvic tilt before manipulation. 40% of subjects showed decreased asymmetrical right versus left pelvic tilt after manipulation, and 60% of subjects showed symmetrical right versus left pelvic tilt after manipulation. I think that pelvic tilt asymmetry with hypomobility due to loss of joint play could be symmetrized by manipulation or mobilization, but pelvic tilt asymmetry with unilateral pelvic muscle shortening could not be symmetrized by manipulation or mobilization without relaxation and stretching of shortened muscles.

• Journal of Korean Physical Therapy Science
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• v.8 no.1
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• pp.893-906
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• 2001

The purposes of this study were to compare pelvic tilt. range of motion(ROM) of hip rotation, and leg length difference before and after manipulation and to investigate correlation between changes of each variables after manipulation of sacroiliac pint in 31 low back pain patients(11 males, 20 females) with sacroiliac pint dysfunction. The sacroiliac pint of patients was manipulated on the side of anterior pelvic tilt, using the technique described by Stoddard(1962) and Greenmann (1996). I used this technique because it usually eliminated sacroiliac Pint dysfunction in one treatment session. SPSS for window computer system was used to analyze the data. Also t-test was performed for comparison of the variables before and after manipulation, and Pearson product-moment correlation analysis and regression analysis were performed for changes of each variables after manipulation. The result were as follows: 1. The pelvic tilt after manipulation was significantly decreased(mean=$2.79^{\circ}$) compared with the pelvic tilt before manipulation(p=.001). 2. The PROM of hip internal rotation ipsilateral to anterior pelvic tilt after manipulation significantly decreased (mean = $1.88^{\circ}$) compared with hip internal rotation before manipulation (p=.008). The PROM of hip internal rotation ipsilateral to posterior pelvic tilt after manipulation significantly increased(mean = $1.29^{\circ}$) compared with hip internal rotation before manipulation (p=.029). 3. The PROM of hip external rotation ipsilateral to anterior pelvic tilt after manipulation significantly increased(mean=$2.42^{\circ}$) compared with the hip external rotation before manipulation(p=$2.42^{\circ}$) compared with the hip external rotation ipsilateral to posterior pelvic tilt after manipulation significantly decreased(mean = $1.84^{\circ}$) compared with the hip external rotation before manipulation (p=.008). 4. Leg length difference after manipulation significantly decreased(mean=2.15 mm) compared with leg length difference before manipulation (p=.008). Regression analysis revealed that a fair correlation was found between change in leg length difference and change in anterior pelvic tilt after manipulation(p=.009). 5. Pearson product-moment correlation coefficient was used to assess differences of the variables after manipulation. A fair correlation was found between change in leg length difference and change in anterior pelvic tilt after manipulation(r=.462, p<.01). A fair correlation was found between change in anterior pelvic tilt and change in hip internal rotation ipsilateral to anterior pelvic tilt(r=.397, p<.05) and between change in anterior pelvic tilt and change in hip external rotation ipsilateral to anterior pelvic tilt(r=.516, p<.01). A fair correlation was found between change in posterior pelvic tilt and changes in hip internal rotation ipsilateral to posterior pelvic tilt (r=.441, p<.05) and between change in posterior pelvic tilt and change in hip external rotation ipsilateral to posterior pelvic tilt(r=.361, p<.05). A fair correlation was found between change in hip internal rotation ipsilateral to anterior pelvic tilt and change in hip external rotation ipsilateral to posterior pelvic tilt(r=.388, p<.05) and between change in hip internal rotation ipsilateral to posterior pelvic tilt and change in hip internal rotation ipsilateral to anterior pelvic tilt(r=.426. p<.05).

• Journal of Broadcast Engineering
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• v.17 no.6
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• pp.1106-1109
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• 2012

The stability of object tracking in non-stationary camera environment, such as intelligent surveillance system using a pan/tilt camera, is less stable compared with stationary camera environment. This is due to the fact that it is difficult to model a background image in non-stationary environment. In this letter, we propose a non-stationay pan/tilt camera surveillance system which uses a stop/go procedure together with a real-time active contour. The proposed system can track the object stable even in an environment where only a few difference frames can be obtained.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.132.2-132.2
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• 2011

We are developing Adaptive Optics (AO) system for astronomical use. The He-Ne laser works as an artificial light source. The tip-tilt correction servo is added to our AO system. The tip-tilt term, among the Zernike terms, is the biggest contributor of wavefront deformation caused by atmospheric turbulence at small telescopes. The tip-tilt correction servo consists of a Piezo tip-tilt platform with a mirror, a quadrant photodiode as a tip-tilt sensor, and controllers. The Shack-Hartmann wavefront sensor measures the residual wavefront errors and they are corrected by the MEMS (Micro Electro Mechanical System) deformable mirror. The MEMS deformable mirror allows the compact size at low cost compare to adaptive secondary mirror and other deformable mirrors. As the frame rates of the MEMS deformable mirror is about tens of kHz, the frame rates of the detector in wavefront sensor is the bottleneck of the wavefront correction speed. For faster performance, we replaced a CCD which provides frame rates only 70 Hz with a CMOS with frame rates up to 450 Hz.

• Journal of International Academy of Physical Therapy Research
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• v.12 no.2
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• pp.2308-2313
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• 2021

Background: Although the scapular posterior tilt movement could facilitate the lower trapezius (LT) muscle activity, no study identified the effects of the scapular posterior tilt movement on the selective activation of the LT muscle during prone shoulder extension. Objectives: To examine the influences of additional scapular posterior tilt on electromyography (EMG) of the upper trapezius (UT) and the LT muscles during prone shoulder extension. Design: Cross-sectional study. Methods: There were 15 asymptomatic male participants in this study who performed prone shoulder extension with and without scapular posterior tilt movements. For the scapular posterior tilt movements, participants performed visual biofeedback training for scapular movement using motion sensor. During the exercises, the EMG activity of the UT and LT was recorded using surface EMG system. Results: The EMG activity of the LT significantly increased during prone shoulder extension with scapular posterior tilt compared to that of general prone shoulder extension, whereas that of the UT was not significantly different between the two exercises. Moreover, scapular posterior tilt application significantly decreased UT/LT muscle activity ratio. Conclusion: Scapular posterior tilt movement may be emphasized during exercise when facilitating LT muscle activation.