• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.3
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• pp.232-239
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• 2008

The position sensors used in a magnetic bearing system are desirable to provide some degree of fault-tolerance as the rotor position is necessary for the feedback control to overcome the open-loop instability. In this paper, we propose an inductive position sensor that can cope with a partial fault in the sensor. The sensor has multiple poles which can be combined to sense the in-plane motion of the rotor. When a high-frequency voltage signal drives each pole of the sensor, the resulting current in the sensor coil contains information regarding the rotor position. The signal processing circuit of the sensor extracts this position information. In this paper, we used the magnetic circuit model of the sensor that shows the analytical relationship between the sensor output and the rotor motion. The multi-polar structure of the sensor makes it possible to introduce redundancy which can be exploited for fault-tolerant operation. The proposed sensor is applied to a magnetically levitated turbo-molecular vacuum pump. Experimental results validate the fault-tolerance algorithm.

• The Korean Journal of Health Service Management
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• v.5 no.2
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• pp.63-76
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• 2011

It is necessary to access managing human resources of hospitals with diversity in order to operate hospital organization successfully and efficiently. The research tries to analyze affecting factors of organizational effectiveness of hospital workers according to their positions. The research has been performed on the 836 hospital workers of 8 different positions in the Busan & Gyeong-nam area, utilizing SPSS version 19.0 for processing and analyzing the data. The major results of the research are as following. First, among such factors of organizational effectiveness as sense of belonging to work, pride, work settlement, wage satisfaction, job satisfaction, colleague perception, and unstable consciousness of their job, there is a meaningful difference according to the kinds of working institution and positions. Second, there was higher organizational effectiveness(a sense of belonging and pride) as to higher work settlement and wage satisfaction within all kinds of positions. In addition, there was higher organizational effectiveness(a sense of belonging and pride) as to higher job satisfaction and colleague perception within all kinds of positions except for physical therapist, general adminstration, facilities, nutrition, and etc. There was higher organizational effectiveness(a sense of belonging and pride) within all kinds of positions except for general adminstration, facilities, nutrition, and etc, as to lower job or work complaint.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.878-881
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• 2003

To acquire an appointed speaker's clear voice signal from inspect-camera, picture-conference or hands free microphone eliminating interference noises needs to be preceded speaker's position automatically. Presumption of sound source position's basic algorithm is about measuring TDOA(Time Difference Of Arrival) from reaching same signals between two microphones. This main project uses ADF(Adaptive Delay Filter) [4] and CPS(Cross Power Spectrum) [5] which are one of the most important analysis of TDOA. From these analysis this project proposes presumption of real time sound source position and improved model NI-ADF which makes possible to presume both directions of sound source position. NI-ADF noticed that if auditory sense of humankind reaches above to some specified level in specified frequency, it will accept sound through activated nerve. NI-ADF also proposes practicable algorithm, the presumption of real time sound source position including both directions, that when microphone loads to some specified system, it will use sounds level difference from external system related to sounds of diffraction phenomenon. In accordance with the project, when existing both direction adaptation filter's algorithm measures sound source, it increases more than twice number by measuring one way. Preserving this weak point, this project proposes improved algorithm to presume real time in both directions.

• Physical Therapy Korea
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• v.25 no.2
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• pp.71-77
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• 2018

Background: There are insufficient objective or quantitative evidence for the better intervention to improve proprioception particularly for the application of external load. There are conflicting opinions whether the external load is effective for proprioception improvement or not. Objects: The purpose of this study was to investigate effects of external load on proprioception of shoulder joint quantitatively using 3D motion capture system. Methods: Nine healthy adults joined for this study. They were asked to perform scapular plane abduction motion with attaching reflective markers on the trunk and upper limb. The 3D positions of finger marker, while they performed the same task with and without external load, were recorded and analyzed. Results: All participants showed decreased variable errors in the vertical direction when the external load was applied (p<.02). Even though other directions (y, z) and absolute errors increased, they did not have statistical significances. Conclusion: Based on this study results, the external load application would be effective for shoulder joint position sense improvement.

• Journal of the Korean Society of Physical Medicine
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• v.2 no.2
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• pp.143-150
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• 2007

Purpose : This article was a quasi-experimental study that applies to external -feedback weight-bearing training among hemiplegic patients with a stoke. Methods : It examined whether position sense and balance can improve fall efficacy and prevent a fall. The subject of study was divided in two; Experimental group had 18 people and control group had 16 people. It took 8 weeks to finish training. Experimental group provides external-feedback weight-bearing training for ten minutes after neurological treatment for 20 minutes and control group provides nerves treatment for 30 minutes. To find the effect of a fall assessed position sense, balance and fall efficacy of the lower limbs before the fact, after 4 weeks and 8 weeks. Results : According to the conclusions, external-feedback weight-bearing training to prevent a fall was more effective intervention in experimental group than in control group. Conclusion : This study suggests that external-feedback weight-bearing training is a intervention to prevent the fall of hemiplegic patients with a stroke effectively.

• Asia Marketing Journal
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• v.15 no.2
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• pp.99-116
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• 2013

This study examines whether product promotions are influenced by the market standing of promoted products, using social comparison theory (upward versus downward comparisons). It is hypothesized that people in possession of a product that is inferior to the one on promotion express less discomfort about the promotion and use the information more than do people in possession of a superior product. People in possession of an inferior product may also exhibit more positive attitudes toward the product on promotion, but may show poorer attitudes toward their own possessed product than do people with a superior product. This is because people in an inferior socioeconomic position show a strong motivation to improve themselves through upward social comparison, whereas people in a superior socioeconomic position maintain a strong sense of superiority in downward social comparison, which suggests strong endowment effects. The findings mainly support the hypotheses, and suggest that sales promotions are more effective for people who currently own an inferior product, but not for people with a superior product, who have a strong motivation to maintain their sense of superiority. The findings also imply that, in order to attract consumers in the superior market, managers for inferior products need to turn to methods other than sales promotions, which may include introducing a new brand or sub-brand, or emphasizing luxury and modern features. In contrast, managers for superior products may emphasize product functions and attributes of superior products in their promotions, as people with inferior products may consider such information as benefits of the superior products.

• Journal of Korean Physical Therapy Science
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• v.16 no.3
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• pp.11-17
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• 2009

Background: The purpose of this study was designed to find out the effectiveness of reposition sense, muscle fatigue response on lumbar spine after apply lumbosacral stabilization exercise program to 4 patients with chronic low back pain and for 12 weeks. Method: In this study the reposition sense was measured in 3 angle(60, 30, 12) of the lumbar spine motion with blind by MedX test machine and the difference of instability to lumbar vertebra segments in flexion, extension test of standing position and spinal load test Mattress Test by Spinal Mouse. The stabilization exercise program was applied 2 times a week for 12 weeks in hospital and 2 times a day for 20 minutes at home. Result: The results of the present study were that the repositioning sense was appeared the most error in 12 angles of lumbar flexion and Men was appeared to decrease an error more than female in average value of 4 angles after 12 weeks. And average error of male was decrease more than female. Thus the effects of lumbosacral stabilization exercise was improved repositioning sense of prorioceptor. Fatigue response test(FRT) results, in male, was raised muscle fatigue rate during increase weight, on the other hand female appeared lower than male. Conclusion: As a results, lumbosacral stabilization exercise was aided to improvement of lumbar spine repositioning sense and vertebra segments stabilization. It was showed the rate of decrease in typically 12 degree angle point of each 3 angle(60, 36, 12). Especially, that spine instability patients will have a risk when in lifting a load or working with slight flexion posture around 12 degree during the daily of living life and it is probably to increase recurrence rate. Thus, not only lumbar extension muscle strength but also stability of vertebra segments in lumbar spine may be very important.

• Korean Journal of Applied Biomechanics
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• v.15 no.1
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• pp.45-61
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• 2005

Stance is defined as any state in which the total mass of the body is supported by the feet. In order to maintain stance, the sum of gravito-inertial forces acting on the body must be registered by equal and opposite forces at the region of contact between the organism and the support surface. Balance is controlled by applying forces to the surface of support so as to maintain the body's center of mass vertically above the feet. for a muIti-segment organism, there can be a variety of ways in which balance can be controlled, since movements of different body segments can have similar effects on the control of balance. In general, the organism tends to have a body configuration that is aligned with gravito-inertial force when there are no external forces acting on it. If any segments of the body are not aligned with gravito-inertial force vector, a torque on that segment would tend to move the body's center of mass. The maintenance of postural stability is accomplished in humans by a complex neural control system. This requires organizing integrating and acting upon visual, vestibular, and somatosensory input, providing orientation information to the postural control system. The information necessary to control and coordinate movement is provided by the visual sense of eye position with respect to the surrounding surface layout, the vestibular sense of head orientation in the gravito-inertial space, and the somatic sense of body segment position relative to one another and to the support surface. In this study, perception and action capability was examined from various points of view. The underlying assumption of the study was that the change of postural configuration could be effected by organism, environment and task goal.

• Journal of Korea Multimedia Society
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• v.5 no.6
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• pp.646-654
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• 2002

The human sense of touch provides us with an important source of information about our surroundings. Because of its unique position at interface between our bodies and the out world, touch sensation supplies sensory data which helps us manipulate and recognize objects and warn of harmful situation. But tactile sensation was recognized less important than visual sense and auditory sense but it plays an important immersing role in virtual reality and computer game. Tactile sensation can be used to influence to objects according to power and supplied sensory feedback to the player in a virtual environment. This paper investigated the characteristics of tactile sensation of human being and proposed method of sturdy using force sensing sensor, simple force modeling and data structure form for virtual reality and computer game. As a result, force distribution, depth, center point can be calculated using sensor output and this information is very effective to specific position for actions and reactions. This study can used as basic information for tactile sensation and it's application in computer game and virtual realty.

• Phonetics and Speech Sciences
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• v.1 no.4
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• pp.11-15
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• 2009

The aim of this study was to identify production difficulties of Korean learners of English in their articulation of English bilabial stops /p, b/ and labiodental fricatives /f, v/. Sixty non-sense syllables and twelve words were produced three times by nine graduate students. Test scores were measured from the score board made by FluSpeak, a speech training software program, which was designed for English pronunciation practice and improvement. Results show that 1) the subjects had lower scores in producing /p, b/ than /f, v/ from all positions, and 2) subjects had lower scores in medial (inter-vocalic) position than in initial (pre-vocalic) position and in final (post-vocalic) position when they produced /p/, /b/, /f/, and /v/. The results suggest that on the whole, Korean learners of English have much difficulty in producing /b/ and that they also have more articulatory problems in intervocalic than in the other positions when they produce these bilabial stops and labiodental fricatives.