• 한국정밀공학회지
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• 제31권2호
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• pp.157-164
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• 2014

In this paper, we design a gripping force control system using tactile sensor to prevent slip when gripper tries to grasp and lift an object. We use a flexible tactile sensor for measuring uniplanar pressure on gripper's finger and develop an algorithm to detect the onset of slip using the sensor output. We also use a flexible pressure sensor to measure the normal force. In addition, various signal processing techniques are used to reduce noise included in the sensor output. A 3-finger gripper is used to grasp and lift up a cylindrical object. The tactile sensor is attached on one of fingers, and sends output signals to detect slip. Whenever the sensor signal is similar to the slip pattern, gripper force is increased. In conclusion, this research shows that slip can be detected using the tactile sensor and we can control gripping force to eliminate slip between gripper and object.

• 품질경영학회지
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• 제45권3호
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• pp.521-532
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• 2017

Purpose: The purpose of this study is to structure affective factors related to the tactile sense in order to improve tactile sensibility satisfaction of interior material. In this paper, we propose the design direction of interior material by analyzing the association between material properties and affective factors for automotive interior material. Methods: The relationship between sensibility adjectives and feelings related to tactile sensation were derived through factor analysis after touching prepared samples that were made by changing the material properties of automotive interior material. The association between affective factors and interior material properties were analyzed through ANOVA. Results: Seven kinds of visual and tactile affective factors were derived from the correlation between feeling of material and sensibility adjectives measured by 215 subjects. It is found that there is a quadratic relationship rather than a linear relationship through association analysis between affective factors and the material properties such as roughness, friction coefficient, and hardness. Conclusion: This study suggests the direction of the interior material design which can improve the sensibility satisfaction of the automobile customers by identifying the tactile factors related to the material properties of automotive interior material.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.415-420
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• 2012

This paper proposes a novel type of tactile device utilizing magnetorheological (MR) fluid which can be applicable for haptic master of minimally invasive surgery (MIS) robotic system. The salient feature of the controllability of rheological properties by the intensity of the magnetic field (or current) makes this potential candidate of the tactile device. As a first step, an appropriate size of the tactile device is designed and manufactured via magnetic analysis. Secondly, in order to determine proper input magnetic field the repulsive forces of the real body parts such as hand and neck are measured. Subsequently, the repulsive forces of the tactile device are measured by dividing 5 areas. The final step of this work is to obtain desired force in real implementation. Thus, in order to demonstrate this goal a neuro-fuzzy logic is applied to get the desired repulsive force and the error between the desired and actual force is evaluated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1524-1525
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• 2007

A flexible tactile sensor module based on polyimide matrix integrated with sensing elements and pluggable terminals connector was fabricated by polymer micromachining technology for robotic applications. The tactile sensor arrays are composed of $4{\times}4$, $8{\times}8$ and $16{\times}16$ sensing elements connected with pluggable terminals connector, respectively. Especially, both the tactile sensor array and the pluggable terminals are formed in the sensor module during the fabrication process. The fabricated tactile sensor module is measured continuously in the normal force range of $0{\sim}1N$ with tactile sensor auto-evaluation system. The value of resistance is relatively increased linearly with normal force in the overall range. The variation rate of resistance is about 2.0%/N in the range of $0{\sim}0.6N$ and 1.5%/N in the range of $0.6{\sim}1N$. Also, the flexibility of the sensing module is adequate to be placed on any curved surface as cylinder because the matrix consists of polymer and metal thin film.

• Smart Structures and Systems
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• 제9권6호
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• pp.535-547
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• 2012

Controlling the balance of motion in a context involving a biped robot navigating a rugged surface or a step is a difficult task. In the present study, a $3{\times}5$ flexible piezoelectric tactile sensor array is developed to provide a foot pressure map and zero moment point for a biped robot. We introduce an innovative concept involving structural electrodes on a piezoelectric film in order to improve the sensitivity. The tactile sensor consists of a polymer piezoelectric film, PVDF, between two patterned flexible print circuit substrates (FPC). Additionally, a silicon rubber bump-like structure is attached to the FPC and covered by a polydimethylsiloxane (PDMS) layer. Experimental results show that the output signal of the sensor exhibits a linear behavior within 0.2 N ~ 9 N, while its sensitivity is approximately 42 mV/N. According to the characteristic of the tactile sensor, the readout module is designed for an in-situ display of the pressure magnitudes and distribution within $3{\times}5$ taxels. Furthermore, the trajectory of the zero moment point (ZMP) can also be calculated by this program. Consequently, our tactile sensor module can provide the pressure map and ZMP information to the in-situ feedback to control the balance of moment for a biped robot.

• International Journal of Computer Science & Network Security
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• 제22권9호
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• pp.15-22
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• 2022

The Tactile Internet technology is considered as the evolution of the internet of things. It will enable real time applications in all fields like remote surgery. It requires extra low latency which must not exceed 1ms, high availability, reliability and strong security system. Since it appearance in 2014, tremendous efforts have been made to ensure authentication between sensors, actuators and servers to secure many applications such as remote surgery. This human to machine relationship is very critical due to its dependence of the human live, the communication between the surgeon who performs the remote surgery and the robot arms, as a tactile internet actor, should be fully and end to end protected during the surgery. Thus, a secure mutual user authentication framework has to be implemented in order to ensure security without influencing latency. The existing methods of authentication require server to stock and exchange data between the tactile internet entities, which does not only make the proposed systems vulnerables to the SPOF (Single Point of Failure), but also impact negatively on the latency time. To address these issues, we propose a lightweight authentication protocol for remote surgery in a Tactile Internet environment, which is composed of a decentralized blockchain and physically unclonable functions. Finally, performances evaluation illustrate that our proposed solution ensures security, latency and reliability.

• PNF and Movement
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• 제21권2호
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• pp.265-272
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• 2023

Purpose: The purpose of this study was to investigate tactile sense perception of the lower extremities according to physical function in children with spastic cerebral palsy. Methods: This study was conducted on 15 children diagnosed with spastic cerebral palsy. Physical function measurement items included dynamic balance ability, gross motor function level, and lower extremity ankle spasticity. The lower extremity tactile sensation uses a monofilament to measure the sole of the first metatarsal head, the sole of the fifth metatarsal head, the heel, the anterior part of the shin midway between the patella and the ankle joint, the kneecap, the upper anterior iliac spine, and the knee. A total of six measurements were taken in the mid-femoral region of the bone. Spearman correlation analysis was performed to determine the degree of body function and lower extremity tactile perception. Results: As the physical function of children with spastic cerebral palsy deteriorated, there was a decrease in tactile sensation in the thigh area corresponding to the proximal lower extremity. (p <.05). Conclusion: Children with spastic cerebral palsy and poor physical function have sensory loss not only in the distal part but also in the proximal part, so a treatment approach that recognizes and improves it is necessary.

• 감성과학
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• 제14권1호
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• pp.127-136
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• 2011

본 연구에서는 견직물의 색채 특성이 촉감각/감성 이미지에 미치는 영향을 고찰하고 견직물의 역학적 성질과 색채 특성을 이용한 촉감각/감성 이미지 예측모델을 제안하고자 하였다. 연구결과로서 무채색과 유채색 견직물 모두 견직물의 역학적 성질이 기본적으로 촉감각/감성 이미지에 영향을 미치는 것으로 나타났다. 반면에 '매끄럽다', '하늘하늘하다', '독특하다', '두껍다', '뻣뻣하다', '전원적이다', '캐주얼하다', '내추럴하다', '모던하다'는 무채색과 유채색에 따라 유의한 차이가 있었다. 특히 '두껍다'와 '뻣뻣하다'는 견직물이 Red 또는 Green 색상일 때, 그리고 pale 또는 vivid 색조일 때 무채색일 때보다 더 강하게 인지되었고, '전원적이다'와 '캐주얼하다'는 Green 색상의 견직물과 pale 또는 vivid 색조의 견직물에서 무채색 견직물에서보다 더 강하게 느껴지는 경향이어서, 견직물의 색채가 주관적 촉감각/감성에 영향을 줄 수 있음을 시사하였다. 마지막으로 역학적 성질과 색채 특성을 함께 설명변수로 이용한 예측모델을 수립하여 제안하였다.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제21권1호
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• pp.57-66
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• 2015

Purpose : The guidelines of establishing convenience facilities for the handicapped have not consistently been provided to the identical criteria in walking facilities. Thus, transportation poor had difficulties in walking environment. Method : This study aims to suggest the practical direction of guidelines of establishing tactile walking surface indicators. To do this, this study examines the problems of the current guidelines for establishing facilities, and then analyzes international criteria, with comparing criteria used in German. Therefore, findings from those analyses can provide the secure and convenient environment for walking to transportation users, in particular blind and vision-impaired people, the handicapped, the child, and the elderly and the weak. Results : For the improvement of tactile walking surface indicators, the clear criteria of establishing tactile walking surface indicators is proposed, considering the characteristics of walking environment. Then, the sample items corresponding to the various situations need to be exemplified. To provide more secure environment walking for transportation poor, the establishing criteria partially adopted ideas from Universal Design also need to be developed. Implication : The proposed detail drawing of tactile walking surface indicators need to be tested by transportation users due to high safety in walking circumstance, and also the guidelines of continuously maintaining tactile walking surface indicators also needs to be studied.

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2002년도 가을학술발표대회 디자인학 연구
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• pp.74-75
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• 2002