• Transactions of the Society of Information Storage Systems
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• v.7 no.2
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• pp.65-69
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• 2011

Head Disk Interface (HDI) in a Hard Disk Drive (HDD) has decreased to achieve high areal density. Thus, the contact between a slider and a disk becomes more important. The contact between the slider and the disk can cause severe wear and damage of both the slider and the disk. Especially, Touch Down (TD) that the contact occurs continuously and repeatedly is extremely dangerous. Therefore, it is necessary to analyze the unstable bouncing vibration of the slider in head-disk interface. In this paper, we investigate the characteristic and causes of the Touch Down.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.39-41
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• 2003

본 논문은 TPMS(Tire Pressure Monitoring System) 개발을 목적으로 압력센서를 무전원/무선 표면탄성파 센서를 이용하여 측정할 수 있는 방법을 연구한 것이다. Touch mode 방식의 압력센서의 경우 Touch down 되었을 때 정전용량은 큰 변화를 가지며 이후 압력의 증가에 대해 선형적으로 증가한다는 것을 이론적인 계산을 통해서 확인하였다. 또한 이와 같은 특성은 표면탄성파 센서의 응답 주파수의 변화를 통해 측정이 가능하다는 이론적인 모델링을 제시하였다.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.99-116
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• 2003

The purpose of this study was to kinematics factors on during round-off at end of beam-salto backward stretched with step-out to cross on balance beam. Four elite female gymnastics players participated as subject of this study. The methods of this study was analyzed using three dimentional analysis. The results and conclusion of this paper is obtained as follows ; 1. The phase of time was the most short time in board touch down phase and board take-off phase. Also, it was shown a more long time in total time compared to previous study. 2. The horizontal displacement of each phase was shown the most high levels in balance beam landing. The vertical displacement was display a non-linearity increase in board take-of phase, and it was shown the most high levels in vertical displacement during landing of balance beam. 3. The horizontal velocity of each phase was shown the most high levels in board touch down, and it was display a gradually decreased levels because flight during board take-of. The resultant velocity of CG on each phase was shown the most high levels in board touch down and board take-off. 4. The angle of hip joint was shown the most high levels as performed a motion in extension state during board take-off, and the angle of knee joint was display a increased levels because of flight cause body extension in board take-off. Also the angle of ankle joint was shown a increasing levels during board take-off. Considering to this results, it is suggest that the change of kinematics factors in board touch down and board take-off is key role on the effective board control.

• Physical Therapy Korea
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• v.31 no.1
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• pp.29-39
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• 2024

Background: Landing from a step or stairs is a basic motor skill but high incidence of lateral ankle sprain has been reported during landing with inverted foot. Objects: This study aimed to investigate the effect of landing height and visual feedback on the kinematics of landing and supporting lower limbs before and after the touch down and the ground reaction force(GRF)s. Methods: Eighteen healthy females were voluntarily participated in landing from the lower (20 cm) and the higher (40 cm) steps with and without visual feedback. To minimize the time to plan the movement, the landing side was randomly announced as a starting signal. Effects of the step height, the visual feedback, or the interaction on the landing duration, the kinematic variables and the GRFs at each landing event point were analyzed. Results: With eyes blindfolded, the knee flexion and ankle dorsiflexion on landing side significantly decreased before and after the touch down. However, there was no significant effect of landing height on the anticipatory kinematics on the landing side. After the touch down, the landings from the higher step increased the knee flexion and ankle dorsiflexion on both landing and supporting sides. From the higher steps, the vertical GRF, anterior GRF, and lateral GRF increased. No interaction between step height and visual feedback was significant. Conclusion: Step height and visual feedback affected the landing limb kinematics independently. Visual feedback affected on the landing side while step height altered the supporting side prior to the touch down. After the touch down, the step height had greater influence on the lower limb kinematics and the GRFs than the visual feedback. Findings of this study can contribute to understanding of the injury mechanisms and preventing the lateral ankle sprain.

• Journal of Korean Academy of Nursing
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• v.25 no.4
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• pp.633-640
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• 1995

The trends in nursing practice are not disease-oriented approaches but holistic, humanistic approaches such as human touch, which is an easily applied, economic, and efficient intervention. The purposes of this paper were to clarify the meaning of the concept "touch" to define the precise attributes of “touch” which could be a basis for nursing interventions. This study uses Walker & Avant's process of concept analysis. The concept of touch can be defined as follows : Touch is a process of communication and physical contact with intention, which is transfered by tactile senses. Attributes of touch are defined as 1) It is transferred by tactile senses. 2) A process of communication 3) A expressive pathway of emotion 4) It has intention. Antecedents of "touch" consist that 1) the touch provider understands the touch receiver's perception of past experiences of touch : 2) the touch provider is concerned about the touch receiver and comes up to the touch receiver : 3) the touch provider wants to deliver his /her emotions ; 4) the touch receiver needs the ability to differentiate the tactile senses. In regard to the consequences of touch, it is expected to keep the touching action between the touch provider and receiver, to feel empathy, to able to perceive the consumer's needs, to feel comfort, intimacy, trust, and to calm down the physiological variables. That is performing the nursing as a caring science.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.791-792
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• 2011

• Journal of the Ergonomics Society of Korea
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• v.31 no.4
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• pp.515-523
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• 2012

Objective: The aim of this study is to investigate users' intuitive stereotypes on non-touch gestures and establish the gesture dictionary that can be applied to gesture-based interaction designs. Background: Recently, the interaction based on non-touch gestures is emerging as an alternative for natural interactions between human and systems. However, in order for non-touch gestures to become a universe interaction method, the studies on what kinds of gestures are intuitive and effective should be prerequisite. Method: In this study, as applicable domains of non-touch gestures, four devices(i.e. TV, Audio, Computer, Car Navigation) and sixteen basic operations(i.e. power on/off, previous/next page, volume up/down, list up/down, zoom in/out, play, cancel, delete, search, mute, save) were drawn from both focus group interview and survey. Then, a user participatory design was performed. The participants were requested to design three gestures suitable to each operation in the devices, and they evaluated intuitiveness, memorability, convenience, and satisfaction of their derived gestures. Through the participatory design, agreement scores, frequencies and planning times of each distinguished gesture were measured. Results: The derived gestures were not different in terms of four devices. However, diverse but common gestures were derived in terms of kinds of operations. In special, manipulative gestures were suitable for all kinds of operations. On the contrary, semantic or descriptive gestures were proper to one-shot operations like power on/off, play, cancel or search. Conclusion: The touchless gesture dictionary was established by mapping intuitive and valuable gestures onto each operation. Application: The dictionary can be applied to interaction designs based on non-touch gestures. Moreover, it will be used as a basic reference for standardizing non-touch gestures.

• Journal of the Ergonomics Society of Korea
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• v.35 no.4
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• pp.277-291
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• 2016

Objective: The aim of this study is to propose a unit touch gesture model, which would be useful to predict the performance time on mobile devices. Background: When estimating usability based on Model-based Evaluation (MBE) in interfaces, the GOMS model measured 'operators' to predict the execution time in the desktop environment. Therefore, this study used the concept of operator in GOMS for touch gestures. Since the touch gestures are comprised of possible unit touch gestures, these unit touch gestures can predict to performance time with unit touch gestures on mobile devices. Method: In order to extract unit touch gestures, manual movements of subjects were recorded in the 120 fps with pixel coordinates. Touch gestures are classified with 'out of range', 'registration', 'continuation' and 'termination' of gesture. Results: As a results, six unit touch gestures were extracted, which are hold down (H), Release (R), Slip (S), Curved-stroke (Cs), Path-stroke (Ps) and Out of range (Or). The movement time predicted by the unit touch gesture model is not significantly different from the participants' execution time. The measured six unit touch gestures can predict movement time of undefined touch gestures like user-defined gestures. Conclusion: In conclusion, touch gestures could be subdivided into six unit touch gestures. Six unit touch gestures can explain almost all the current touch gestures including user-defined gestures. So, this model provided in this study has a high predictive power. The model presented in the study could be utilized to predict the performance time of touch gestures. Application: The unit touch gestures could be simply added up to predict the performance time without measuring the performance time of a new gesture.

• Transactions of the Society of Information Storage Systems
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• v.8 no.2
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• pp.61-66
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• 2012

In HDD industry, many technologies have been developed and investigated as means to increase the areal density of drives. Especially, heat assisted magnetic recording (HAMR) system has been considered as the next generation storage device. Most of the HAMR systems use near field optics as heating mechanism. Therefore, light delivery system is indispensable. We considered the light delivery system with laser diode (LD) mount and optical fiber. Mass and stiffness of the HAMR system using these LD mount and optical fiber are changed. The mass and stiffness of the HAMR system affects the slider dynamic behavior. It is necessary to analyze touch down (TD) and take off (TO). And, we performed the TD-TO experiment with HAMR suspension. Finally, we analyzed the result of TD-TO experiments. And we suggested the design of HAMR suspension to improve TD-TO performance.

• Journal of the Ergonomics Society of Korea
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• v.29 no.4
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• pp.541-546
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• 2010

The gesture 'Flick' is the most fundamental and important part for efficient interactions in the touch screen that are being extensively applied to mobile phones. This study investigated users' satisfaction of the flick operation in representative touch phones, and measured their performances with established three measures: gap between finger and initial cursor, the number of moved lists per 0.2 seconds, and the number of moved lists after ten continuous flicks. The measurement was performed with high speed camera and motion analysis software. The flick movement in mobile phone with high users' satisfaction showed that the gap between finger and cursor positions was less and the speed reached high within 0.6 seconds quickly and then was drastically slow down. Especially, maximal and common time intervals between continuous flicks were measured with an experiment. Based on the evaluation and measurement, several design guidelines for efficient flick performances were suggested.