• Asian-Australasian Journal of Animal Sciences
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• v.13 no.2
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• pp.167-175
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• 2000

This paper describes the magnetic orientation of bull sperm separated into the head and the flagellum treated by DTT or heparin in a 5,400G static field. Semen samples collected from four bulls (Japanese Black) were mixed to the same sperm density. One percentage triton X-100 was used to extract the plasma membrane. The intact and demembranated sperm suspensions were treated with 20, 200, 2,000 mM DTT, 100, 1,000 or 10,000 units heparin solutions at $4^{\circ}C$ for 6 days. The decondensation of the sperm nuclei treated by DTT or heparin was examined by measuring the head area at 1, 3 and 6 days. After measuring the area, each sample was exposed to a 5,400G static magnetic field generated by Nd-Fe-B permanent magnets for 24 hours at room temperature. Results showed that the sperms were separated into the head and the flagellum through the DTT treatment. Almost of the separated heads showed that their long axis oriented perpendicularly to the magnetic lines of force, and most of the long axis perpendicularly oriented heads showed that their flat plane oriented perpendicularly in a 5,400G magnetic field. Also, the demembranation of the head tended to increase those perpendicular orientations, while those perpendicular orientations of the head declined with the decondensation of the sperm nuclei. These findings suggest that strong magnetic anisotropy for the perpendicular orientation of the long axis and the flat plane of the head occurs in the sperm nuclei in a 5,400G magnetic field. The separated flagellum showed lower parallel orientation, and the separated and demembranated flagellum showed parallel orientation to the magnetic lines of force in this magnetic field. These findings suggest that weak magnetic anisotropy of the parallel orientation of the flagellum occurs in the inside components in a 5,400G field.

• Progress in Superconductivity and Cryogenics
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• v.14 no.3
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• pp.48-52
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• 2012

This paper describes experimental study on the orientation dependence of GM-type pulse tube refrigerator with helium and neon as working gas. A pulse tube refrigerator generates refrigeration work with gas expansion by gas displacer in the pulse tube. The pulse tube is only filled with working gas and there exists secondary flow due to large temperature difference between cold-end and warm-end. The stability of secondary flow is affected by orientation of cold-head and thus cooling performance is deteriorated by gas mixing due to secondary flow. In this study, a single stage GM-type pulse tube with orifice valve as a phase control device is fabricated and tested. The fabricated pulse tube refrigerator is tested with two different working gases of helium and neon. First, optimal valve opening and operating frequency are determined with experimental results of no-load test. And then, the variation of no-load temperature as orientation angle of cold-head is measured for two different working gases. Effect of orientation dependence of cold-head as working gas is discussed with experimental results.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.1
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• pp.10-18
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• 2000

This paper describes the magnetic orientation of the intact and demembranated bull sperm treated by DTT or heparin in a 5,400 G static field. Semen samples collected from four bulls (Japanese Black) were mixed to the same sperm density. One percentage triton X-100 was used to extract the plasma membrane. The intact and demembranated sperm suspensions were treated with 20, 200, 2,000 mM DTT, 100, 1,000 or 10,000 units heparin solutions at $4{^{\circ}C}$ for 6 days. The decondensation of the sperm nuclei treated by DTT or heparin was examined by measuring the sperm head area at 1, 3, and 6 days. After measuring the area, each sperm sample was exposed to a 5,400 G static magnetic field generated by Nd-Fe-B permanent magnets for 24 hours at room temperature. Results showed that the decondensation of bull sperm nuclei was not induced by the heparin treatment, however, incomplete decondensation was induced by the DTT treatment. During the magnetic orientation, bull sperms treated by DTT or heparin had low percentages of long axis perpendicular to the magnetic lines of force. However, different aspects were obtained for long axis perpendicular orientations following treatment of DTT or heparin. Through the DTT treatment, the decline of long axis perpendicularly oriented percentages was due to the increase of long axis parallel orientation with the head of the flat plane perpendicular to the magnetic lines of force, whereas, using the heparin treatment, the decline of long axis perpendicular orientation was due to the increment of long axis parallel orientation with the head of the flat plane parallel to the magnetic lines of force. Also, percentages of the head of the flat plane perpendicular were decreased by the heparin treatment. These findings suggest that maintaining the structure of protamine in the chromatin is necessary for the sperm head to orient with its flat plane perpendicular, and maintaining the disulfide bond in the chromatin is necessary for the long axis of sperm to orient perpendicularly.

• Journal of the Ergonomics Society of Korea
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• v.19 no.1
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• pp.77-90
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• 2000

The aim of this study is to develop and evaluate an efficient camera calibration method for vision-based head tracking. Tracking head movements is important in the design of an eye-controlled human/computer interface. A vision-based head tracking system was proposed to allow the user's head movements in the design of the eye-controlled human/computer interface. We proposed an efficient camera calibration method to track the 3D position and orientation of the user's head accurately. We also evaluated the performance of the proposed method. The experimental error analysis results showed that the proposed method can provide more accurate and stable pose (i.e. position and orientation) of the camera than the conventional direct linear transformation method which has been used in camera calibration. The results of this study can be applied to the tracking head movements related to the eye-controlled human/computer interface and the virtual reality technology.

• Journal of the Ergonomics Society of Korea
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• v.16 no.3
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• pp.1-10
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• 1997

This paper is concerned with the development and evaluation of the camera calibration method for a real-time head tracking system. Tracking of head movements is important in the design of an eye-controlled human/computer interface and the area of virtual environment. We proposed a video-based head tracking system. A camera was mounted on the subject's head and it took the front view containing eight 3-dimensional reference points(passive retr0-reflecting markers) fixed at the known position(computer monitor). The reference points were captured by image processing board. These points were used to calculate the position (3-dimensional) and orientation of the camera. A suitable camera calibration method for providing accurate extrinsic camera parameters was proposed. The method has three steps. In the first step, the image center was calibrated using the method of varying focal length. In the second step, the focal length and the scale factor were calibrated from the Direct Linear Transformation (DLT) matrix obtained from the known position and orientation of the camera. In the third step, the position and orientation of the camera was calculated from the DLT matrix, using the calibrated intrinsic camera parameters. Experimental results showed that the average error of camera positions (3- dimensional) is about $0.53^{\circ}C$, the angular errors of camera orientations are less than $0.55^{\circ}C$and the data aquisition rate is about 10Hz. The results of this study can be applied to the tracking of head movements related to the eye-controlled human/computer interface and the virtual environment.

• The Journal of Korean Physical Therapy
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• v.35 no.5
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• pp.156-161
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• 2023

Purpose: This study examined the effects of subjective visual vertical perception and head orientation on static balance control. Methods: The subjects were 25 young and healthy adults. The vertical perception was measured using a subjective visual vertical (SVV), and the Center of pressure (COP) parameter was analyzed by continuously measuring the movement of the COP to determine the changes in static postural control. The group was divided based on a deviation of 3° in SVV (11 of SVV≥3°, 14 of SVV<3°) and measured with different head orientations: front, up, down, left, and right in the upright and tandem positions, respectively. Results: In the upright position, the SVV≥3° group had significantly larger values for all COP parameters (Sway length, Surface, Delta X, Delta Y, and Average speed) compared to the SVV<3° group (p<0.05). In the tandem stance, only the Ellipse Surface value was significantly larger among the COP parameters in the group with SVV≥3° compared to the group with SVV<3°(p<0.05). In contrast, the other COP parameters were not significantly different (p>0.05). The effects of static balance control on the head orientation were not statistically significant (p>0.05), and the interactions between the subjective vertical perception and head orientation were not significant (p>0.05). Conclusion: These results suggest that pathological deviations in SVV are associated with impaired static balance performance. This study can provide a therapeutic rationale for using visuospatial cognitive feedback training to improve the static balance.

• Progress in Superconductivity and Cryogenics
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• v.14 no.4
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• pp.50-53
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• 2012

This paper describes experimental study on GM-type pulse tube refrigerator (PTR). In a PTR, the pulse tube is only filled with working gas and there exists secondary flow due to a large temperature difference between cold-end and warm-end. The stability of secondary flow is affected by orientation of cold-head and thus, the cooling performance is deteriorated by gas mixing due to secondary flow. In this study, a single stage GM-type pulse tube refrigerator is fabricated and tested. The cooing performance of the fabricated PTR is measured as varying cold-head orientation angle and the results are used as reference data. Then, we divided interior space of pulse tube into three segments, and fixed the various size of screen mesh at interface of each segment to suppress the performance degradation due to secondary flow. For various configuration of pulse tube, no-load test and heat load test are carried out with the fixed experimental condition of charging pressure, operating frequency and orifice valve turns. From experimental results, the fine screen mesh shows the effective suppression of performance degradation for the large orientation angle, but the use of screen mesh cause the loss of cooling capacity rather than the case of no insertion into pulse tube. It should be compromised whether the use of screen mesh in consideration of the installation limitation of a GM-type pulse tube refrigerator.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.3
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• pp.337-342
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• 2013

PURPOSE: The Unilateral neglect is characterized by difficulty shifting attention to the side of space opposite the brain lesion and frequently reducing use of contralesional extremities. This study was to identify whether the visual deprivation was responsible for head position on unilateral neglect patient after stroke. METHODS: A patient with left middle cerebral artery infarction participated in the study. We assessed neglect using line bisection and star cancellation test. Patient was instructed to maintain correct alignment of trunk and head in a sit position. We evaluated degree of head lateral tilting and rotation. Then, patient was blocked visual input. Also, we evaluated head position in the same way. RESULTS: He scored 3 points in the line bisection test and 9 points star cancellation test. In postural evaluation, he had deviated posture such as lateral head tilting and rotation. After visual cue deprivation, patient showed different head position which was decreased degree of head tilting and rotation. CONCLUSION: For vertical body orientation, it was used multiple sensory references including the vestibular, somatosensory, and visual system. This finding suggested that abnormal posture of neglect patient could be related to the visual input. It has important clinical implications in terms of understanding the neglect.

• Korean Journal of Adult Nursing
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• v.19 no.4
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• pp.593-602
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• 2007

Purpose: The purpose of this study was to develop an e-learning orientation program for nursing students(junior), to evaluate the program, and to find out its effects on adapting to clinical practicum. Methods: The e-learning orientation program was developed according to ADDIE model(analysis, design, develop, implement, evaluate) using an Active Tutor Program. Twelve nursing professionals and 31 nursing students(learners) evaluated the e-learning orientation program. Thirty one nursing students participated in the e-learning orientation program both on-line and off-line. Results: The e-learning orientation program consisted of 5 parts including 'Taking a lesson in gastrointestinal tract', 'Fundamental nursing skill and reading a medical chart', 'Taking a ward orientation by head nurse', 'Clinical practice with preceptors', and 'Writing for case report'. Adapting scores to clinical practicum were significantly different between pre-test and post-test(t=-5.76, p=.000). Conclusion: The e-learning orientation program of on-line and off-line has an effect on adapting to clinical practicum for nursing students.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.173-175
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• 2011

In this paper, we present an user interface which can show some 3D objects at various angles using tracked 3d head position and orientation. In implemented user interface, First, when user's head moves left/right (X-Axis) and up/down(Y-Axis), displayed objects are moved towards user's eyes using 3d head position. Second, when user's head rotate upon an X-Axis(pitch) or an Y-Axis(yaw), displayed objects are rotated by the same value as user's. The results of experiment from a variety of user's position and orientation show good accuracy and reactivity for 3d visualization.