• The Korean Journal of Pain
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• v.12 no.1
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• pp.8-15
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• 1999

Following peripheral nerve injury, rats will show a tactile allodynia and hyperalgesia. But the mechanism of allodynia is still obscure. The present studies, using rats rendered allodynia by loosely constrictive ligation of the common sciatic nerve (Bennett Model) and tight ligation of L5 & L6 spinal nerve (Chung Model), aimed to investigate the changes of metabotrophic glutamate receptor type 5 on the development of tactile allodynia. Male Sprague-Dawley rats (130~200 g) were anesthetized with halothane, the rats were randomly divided into one of these three groups, Group 1 (Sham operation), Group 2 (Bennett model) and Group 3 (Chung model). Seven days after surgical procedure, the animal was reanesthetized and decapitated. The spinal cord was quickly removed and stored at deep freezer for polymerase chain reaction (RT-PCR). In Group 2&3, rats showed that tactile allodynia checked by up-down method with calibrated 8 von Frey hair. The level of gene expression of mGluR5 mRNA was significantly increased in group 2 and 3. These increases was significantly different from sham operation, group 1. It was also showed that the increasing patterns of group 2 and 3 in the gene expression were similar correlation with the results of the threshold for tactile allodynia on von Frey hair test. Even though there were some differences between Bennett model and Chung model, these results suggested that mGluR5 had partly attributed to making a tactile allodynia from these models.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.1
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• pp.67-76
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• 1997

In this paper we developed a tactile feedback device using repulsive force of magnets. The force of the tactile feedback device was derived from the Maxwell's stress method by using the concept of magnetic charge. Magnetic repulsive force is linear function with respect to current and nonlinear to displacement. Experimental data shows these characteristics. To compensate the fact that the presented tactile feedback device can not be controlled by close loop control, we developed a simulation model which predicts output displacement and force by using Runge-Kutta method. And, this paper evaluated the presented tactile feedback device and compared it with commercial tactile feedback devices.

• The Research Journal of the Costume Culture
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• v.28 no.5
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• pp.705-718
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• 2020

The goal of this study was to develop a haptic communication system that can convey the tactile sensation of fashion materials in a virtual environment. In addition, the effectiveness and how realistically the virtual fabric image of this system delivers the tactile sensation of actual fabric was verified. First, a literature review was conducted through which the tactile attributes of fashion materials were defined that would be implemented in the haptic communication system. Then, a questionnaire for evaluating the tactile attributes of fashion materials was developed. Next, a haptic communication system was designed to convey fashion image experiences in a virtual environment, from which a haptic rendering model was suggested. The effectiveness of the haptic communication system was evaluated by verifying user experiences with questions developed through a user evaluation experiment. The validity of the evaluation questions pertaining to the tactile attributes and the effects of the haptic communication system were verified. Factor analysis was conducted to verify the evaluation of the tactile sense attributes of the fashion material, which identified density, thickness, and elasticity of the material as key factors. As a result of comparisons between the tactile sense through haptic characteristics and through touching, it was observed that regarding density and thickness, tactile sense experience led to greater perceived reality, while this was not the case for elasticity.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.587-592
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• 1994

To realize artificial device with sensing ability of the human skin, a mono-material tactile sensor with three sensing functions made of some elastic thin electro-conductive rubber sheet with eight latticed patch elements is proposed. This trial sensor provides the information of three kinds of model material characteristics such as thermal property, hardness property and the surface situation of materials by setting up three kinds of surface models as test materials. It can be finally expected to estimate unknown model materials by analyzing the data of the sensor.

• The Journal of Korea Robotics Society
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• v.17 no.3
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• pp.365-372
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• 2022

The accurate object recognition is important for the precise and accurate manipulation. To enhance the recognition performance, we can use various types of sensors. In general, acquired data from sensors have a high sampling rate. So, in the past, the RNN-based model is commonly used to handle and analyze the time-series sensor data. However, the RNN-based model has limitations of excessive parameters. CNN-based model also can be used to analyze time-series input data. However, CNN-based model also has limitations of the small receptive field in early layers. For this reason, when we use a CNN-based model, model architecture should be deeper and heavier to extract useful global features. Thus, traditional methods like RN N -based and CN N -based model needs huge amount of learning parameters. Recently studied result shows that Fast Fourier Convolution (FFC) can overcome the limitations of traditional methods. This operator can extract global features from the first hidden layer, so it can be effectively used for feature extracting of sensor data that have a high sampling rate. In this paper, we propose the algorithm to recognize objects using tactile sensor data and the FFC model. The data was acquired from 11 types of objects to verify our posed model. We collected pressure, current, position data when the gripper grasps the objects by random force. As a result, the accuracy is enhanced from 84.66% to 91.43% when we use the proposed FFC-based model instead of the traditional model.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1314-1317
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• 1997

For realizing artificial skin sensing as a final goal, a mono-material pressure-conductive rubber sensor which is also sensitive for temperature is described. Firstly, discimination of the hardness and the thermal property of material using a proposed sensor is presented. Furthermore, a tactile sensor constints of four pressure-conductive rubber sensor to discriminate surface model which imitaties the surface roughness of material is proposed.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.1-6
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• 2008

This paper proposes a game controller that provides user motion input and tactile feedback display, in addition to the traditional button-type input. The device utilizes both an accelerometer and an infrared camera in order to estimate 3D position and to recognize user motion. The information from the accelerometer and the camera are integrated for better performance. Various tactile sensations are presented using a voice-coil type vibrator. We apply the proposed controller to a motion-based game and validate its usability.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.5
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• pp.431-437
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• 2018

The running attitude of a planing hull is determined by the pressure distribution on the hull bottom, and it significantly affects hydrodynamic performance of the ship, i.e., resistance, maneuverability, and seakeeping ability. Therefore, it is essential to investigate pressure distribution on the hull bottom in order to improve hull design. In the present study, a novel pressure measurement system using tactile sensors was introduced for a planing hull. The test model was a 23 m-class planing hull with a hard chine. The pressure measurement showed that the pressure at the transom was lower than the atmospheric pressure, owing to flow separation at the transom.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.6
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• pp.478-484
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• 2015

Knowledge about ice load distribution along the ship hull due to ship-ice interaction can provide important background information for the development of design codes for ice-going vessels. The objective of this study is to understand ship and ice interaction phenomena and determine the magnitude of ice load acting along a ship hull. The model tests were performed in the ice model basin in Korea Research Institute of Ships and Ocean engineering (KRISO) with the model of icebreaking ship Araon. Self-propulsion tests in level ice were performed with three difference model ship speeds. In the model tests, three tactile sensors were installed to measure the spatial distribution of ice load acting at different locations on a model ship, such as the bow and shoulder areas. Variation in the distribution of ice load acting on a model hull with ship speed is discussed.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.691-698
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• 2020

In this study, the effects of hydrodynamic interceptors on a high-speed vessel were investigated to identify the operating principle based on experiments. Model tests were performed using a high-speed towing carriage. The resistance, trim and rise of Center of Gravity (CG) of the high-speed vessel were measured for various ship speeds and interceptor heights. As the interceptor height increased, the trim and rise of CG were reduced. In order to quantitatively analyze these phenomena, the pressure at the stern bottom was measured using tactile sensors. The reliability of the measured results from the tactile sensors was verified through repeat tests. The pressure on the stern bottom increased in proportion to the interceptor height, as the interceptor partially blocked the flow there. Then, the trim was reduced. However, as the ship speed increases, the pressure at the location close to the interceptor decreases when the interceptor height is small, leading to increased trim. Therefore, the interceptor height for running attitude control should be carefully determined considering multiple factors in the operating condition of the high-speed planing hull.