• Korean Journal of Applied Biomechanics
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• v.20 no.2
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• pp.197-204
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• 2010

Scapular position and motion are essential for normal upper limb mobility; Further, the posture of patients with thoracic kyphosis is related to shoulder girdle function and disorder. The purpose of this study was to examine the effects of thoracic posture on the shoulder range of motion and on three-dimensional scapular kinematics. Thirty healthy subjects performed right-arm abduction along the frontal plane while standing in both erect and in slouched trunk posture. The scapular position and rotation, and shoulder and thoracic angles were recorded using a motion analysis system. The scapular upward rotation and internal rotation were significantly altered according to postural tatiges; however, scapular tilt was not affected. Shoulder angle was significantly decreased in the slouched posture as c rpared to tatt in the erect posture. Thus, a slouched posture(thoracic kyphosis) significantly affects the shoulder range of motion and scapular kinematics during shoulder abduction in the frontal plane.

• Journal of Medicine and Life Science
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• v.16 no.3
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• pp.64-75
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• 2019

Vertigo and dizziness are common symptoms with various etiologies and pathogeneses. Vertigo is an illusion of motion due to disease of the vestibular system, usually a sense of rotation. Dizziness, a term that represents a wide range of non-vertigo symptoms, is commonly associated with non-vestibular disorders including old age, cardiac syncope, orthostatic hypotension, metabolic disease, anxiety, and drugs. Vertigo should be determined whether the cause is central or peripheral. Peripheral vertigo is usually benign but central vertigo is serious and often require urgent treatment. The careful history and detailed physical examinations(pattern of nystagmus, ocular tilt reaction, head impulse test and positional tests such as Dix-Hallpike maneuver) provide important clues to the diagnosis of vertigo. Most of patients have benign peripheral vestibular disorders - vestibular neuritis, benign paroxysmal positional vertigo (BPPV), and Meniere's disease. BPPV is a leading cause of peripheral vertigo and can easily be cured with a canalith repositioning maneuver. In this review, a focus is on the differential diagnosis of common vestibular disorders with peripheral and central causes.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.1
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• pp.58.2-58.2
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• 2013

We present a photometric study of the globular clusters (GCs) in the giant elliptical galaxy M86 in the Virgo Cluster, using the Washington $CT_1$ images taken at the KPNO 4 m telescope. The color distribution of the GCs in M86 is bimodal. The radial number density profile of the blue GCs decreases more slowly as the galactocentric distance increases than that of the red GCs. The density profile of the red GCs is similar to the surface brightness profile of M86 stellar halo. The blue GCs have a roughly circular spatial distribution, while the red GCs have a spatial distribution somewhat elongated, which is consistent with the distribution of the galaxy stellar light. M86 GCs have the negative radial color gradient because the number ratio of the blue GCs to the red GCs increases as galactocentric radius increases. The mean color of the red GCs is similar to that of the stellar halo. The bright blue GCs in the outer region of M86 reveal a blue tilt that the mean colors of the blue GCs get redder as they get brighter. We discuss these results in comparison with other giant elliptical galaxies in the Virgo Cluster.

• Korean Journal of Construction Engineering and Management
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• v.5 no.5 s.21
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• pp.151-162
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• 2004

Current methods for construction site modeling employ large, expensive laser range scanners that produce dense range point clouds of a scene from different perspectives. Days of skilled interpretation and of automatic segmentation may be required to convert the clouds to a finished CAD model. The dynamic nature of the construction environment requires that a real-time local area modeling system be capable of handling a rapidly changing and uncertain work environment. However, in practice, large, simple, and reasonably accurate embodying volumes are adequate feedback to an operator who, for instance, is attempting to place materials in the midst of obstacles with an occluded view. For real-time obstacle avoidance and automated equipment control functions, such volumes also facilitate computational tractability. In this research, a human operator's ability to quickly evaluate and associate objects in a scene is exploited. The operator directs a laser range finder mounted on a pan and tilt unit to collect range points on objects throughout the workspace. These groups of points form sparse range point clouds. These sparse clouds are then used to create geometric primitives for visualization and modeling purposes. Experimental results indicate that these models can be created rapidly and with sufficient accuracy for automated obstacle avoidance and equipment control functions.

• Journal of Electrical Engineering and Technology
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• v.7 no.6
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• pp.926-931
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• 2012

Since robot industry growing, the machine that could move with multi-DOF has been studied in many industrial fields. Spherical motor is one of the multi-DOF machine that doesn't need gear for multi-DOF motion. Unlike conventional motor, spherical motor can not only rotate on the shaft axis (rotating motion), but tilt the shaft with 2-DOF motion (positioning motion). In the typical type of spherical motor, one coil took part in positioning motion and rotating motion at the same time. As the result, the control algorithm was complex. To solve this problem, this study proposed a novel type of coil on the stator. The coils were separated for positioning motion and rotating motion. Thus the linkage flux of rotating coil didn't be affected the positioning angle. In this paper, comparing the back-EMF of typical and novel type was conducted and the driving experiment was carried out as the positioning angle. From the experiment result, the performance of proposed spherical motor could be verified.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.5
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• pp.1-9
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• 2004

The performance analysis code has been developed for vertical take-off and landing(VTOL) UAV which can be utilized as a trade analysis tool in the pre-conceptual design phase. The UAV requires VTOL capability and high speed cruise performance. The main logic of this performance analysis code is to estimate performance parameters of each mission segment by mission fuel weight iteration. The reliability of this performance analysis code is discussed by comparing the data of existing dual flight mode VTOL UAVs such as Boeing CRW and Bell Tilt Rotor.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.10
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• pp.1986-1991
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• 2007

In this paper, we discussed, intelligent soft filter for MR(magnetoresistive) sensor. Most navigation systems today use some type of compass to determine heading direction. Using the earth's magnetic field, electronic compass based on MR(magnetoresistive) sensors can electrically resolve better then 0.1 degree rotation. Intelligent methode for soft building a one degree compass using MR(magnetoresistive) sensors will also be discussed. Compensation techniques are shown to correct for compass tilt angels and nearby ferrous material disturbances. we proved the fuzzy logic that based on the way the ham deals with inexact information is useful for MR sensors.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.9
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• pp.70-75
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• 2021

We developed a platform that was capable of autonomous steering in a furrow environment. It was developed to autonomously control steering by recognizing the furrow using a laser distance, three-axis tilt, and temperature sensor. The performance evaluation indicated that the autonomous steering success rate was 99.17%, and it was possible to climb up to 5° on the slope. The usage time was approximately 40 h, and the maximum speed was 6.7 km/h.

• Korean Journal of Optics and Photonics
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• v.30 no.1
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• pp.8-14
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• 2019

This paper presents methods to correct and evaluate the chromatic aberration occurring on the cut-off line of a headlamp without additional optical components and alignment process. To correct the chromatic aberration using a geometrical concept, the maximum differences in exit-ray angle between wavelengths are reduced by tilting the convex surface of an aspheric projection lens. To evaluate the chromatic aberration, the position and luminous intensity to be measured are suggested, and the criterion for chromatic aberration is presented through color coordinates. From the evaluation of an automotive headlamp designed using this geometrical method, it is found that the chromatic aberration of the cut-off line is significantly reduced.

• Annals of Clinical Neurophysiology
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• v.21 no.1
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• pp.30-35
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• 2019

Background: Postural tachycardia syndrome (POTS) refers to the presence of orthostatic intolerance symptoms associated with a heart rate increment of greater than 30 beats/min, usually up to 120 beats/min, on head-up tilt test. Symptoms related to POTS are usually light-headedness, palpitations and tremor, but syncope can also occur. The pathophysiology of POTS is heterogeneous and its prognosis is uncertain. Methods: We prospectively evaluated patients who met the criteria for POTS, at baseline and follow-up, using composite autonomic symptom scores and autonomic tests to assess the autonomic function. We compared the clinical and autonomic test results between baseline and follow-up. Results: Sixty-eight patients met the inclusion criteria for POTS and forty-five patients were ultimately followed up for at least 1 year after baseline. The patients were predominantly young females (84%), with a mean age of 21 years. Most patients showed improved orthostatic symptoms and more than a quarter of patients had no longer met the criteria for POTS at follow-up. Conclusions: Most patients had a benign outcome in that they could resume their daily activities without great limitations. Our results demonstrated a relatively favorable prognosis in most patients with POTS.