• Science of Emotion and Sensibility
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• v.5 no.1
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• pp.1-7
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• 2002

This paper studies on the human cognition of object's weight in virtual environment. We design the force input device which consists of a 3D mouse and a simple spring. It provides users with force feedback. The user can measure the weight of an object by the grasping force to move or lift it up in the virtual environment. Three kinds of experiments are performed. The first one is performed to analyze the relationships between the object's weight and its volume. The second one is to find the relationships between the object's weight and the its texture and finally the third one is to find the relationships between the object's weight and the force used to move an object. We conclude from the analysis of the experiment that object's volume or texture are not the critical factor for user to realize its weight. But the grasping force is critical and meaningful in realizing its weight so that the virtual environment with force cue provides users with more immersive environments. And, also the force input device is effective enough for user to feel the weight of the object.

• Journal of the Korea Society of Computer and Information
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• v.23 no.7
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• pp.49-56
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• 2018

Virtual object weight perception is an important topic, as it heightens the believability of object manipulation in immersive virtual environments. Although weight perception can be achieved using haptic interfaces, their technical complexity makes them difficult to apply in immersive virtual environments. In this study, we present a visual pseudo-haptic feedback system that simulates and depicts the weights of virtual objects, the effect of which is weight perception. The proposed method recognizes grasping and manipulating hand motions using computer vision-based tracking methods, visualizing a Force Arrow to indicate the current lifting forces and its difference from the standard lifting force. With the proposed Force Arrow method, a user can more accurately perceive the logical and unidirectional weight and therefore control the force used to lift a virtual object. In this paper, we investigate the potential of the proposed method in discriminating between different weights of virtual objects.

• Science of Emotion and Sensibility
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• v.25 no.2
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• pp.23-30
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• 2022

The weight of an object is an important research topic in terms of sense, and objects have size-weight, color-weight, and material-weight illusions due to the influence of size, color, and material and the weight of the object. Although temperature is a very important environmental factor in our daily life, there is a dearth of studies on how the temperature of an object affects its perceived weight. This study analyzed the effect of an object's temperature on the perceived weight. A stainless steel cup, in which weight and temperature are easily adjustable, was selected as a perceived weight measurement object; 5 temperature levels (0, 9, 20, 40, 70 degrees) and 2 weight levels (250, 400 g) were set. A total of 40 healthy men and women in their 20s participated in the experiment. The weight of the given cup compared to the reference cup was evaluated according to the modulus method. The study revealed that both temperature and weight significantly affected the perceived weight. The effect of temperature on the weight was different depending on the weight of the object. When the cup's weight was small (250 g), the temperature of the cup did not affect the weight. However, the perceived weight of a large cup (400 g) increased at a low temperature. This result suggests that the effect of temperature on the weight of an object depends on the size-weight illusion.

• Journal of Internet Computing and Services
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• v.25 no.1
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• pp.9-15
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• 2024

As virtual reality technology became popular, a high demand emerged for natural and efficient interaction with the virtual environment. Mid-air manipulation is one of the solutions to such needs, letting a user manipulate a virtual object in a 3D virtual space. In this paper, we focus on manipulating a remote virtual object while visually displaying the object and providing tactile information on the object's weight. We developed two types of wearable interfaces that can provide cutaneous or vibrotactile feedback on the virtual object weight to the user's fingertips. Human perception of the remote virtual object weight during manipulation was evaluated by conducting a psychophysics experiment. The results indicate a significant effect of haptic feedback on the perceived weight of the virtual object during manipulation.

• Journal of Korea Multimedia Society
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• v.20 no.7
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• pp.986-993
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• 2017

Object Tracking is a technique for tracking moving objects over time in a video image. Using object tracking technique, many research are conducted such a detecting dangerous situation and recognizing the movement of nearby objects in a smart car. However, it still remains a challenging task such as occlusion, deformation, background clutter, illumination variation, etc. In this paper, we propose a novel deep visual object tracking method that can be operated in robust to many challenging task. For the robust visual object tracking, we proposed a Convolutional Neural Network(CNN) which shares weight of the convolutional layers. Input of the CNN is a three; first frame object image, object image in a previous frame, and current search frame containing the object movement. Also we propose a method to consider the motion of the object when determining the current search area to search for the location of the object. Extensive experimental results on a authorized resource database showed that the proposed method outperformed than the conventional methods.

• Journal of Korean Physical Therapy Science
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• v.31 no.2
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• pp.30-40
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• 2024

Background: The purpose of this study is to identify the difference in muscle activity and muscle contraction onset time according to a LLD and object weight When subjects performed a lifting task. Design: Repeated measure design Methods: 15 male adults participated in this study. When subjects performed a lifting task, we measured a difference of muscle activity and muscle contraction onset time in the rectus abdominis(RA), the erector spinae(ES), and the rectus femoris(RF) between both legs using the surface electromyogram (Telemyo DTS, Noraxon Inc., USA). When subjects performed a lifting task, the weight of the object was set to 0% kg, 10% kg, and 20% kg of the subject's body weight, excluding the weight of the box. Results: The difference in muscle activity in the RA, the ES, and the RF between both legs when lifting an object was larger in LLD condition than in non-LLD condition(p<0.05). In all of muscles, the difference of contraction onset time was generally increased as the object's weight increased. Specially, the difference in muscle contraction onset time in the RA, the ES between both legs was larger in the LLD condition than in the non-LLD condition(p<0.05). Conclusion: This study suggests that LLD affects the muscle activity and muscle contraction onset time during lifting objects. It can be used as data to prevent joint damage and muscle due to the LLD during work and movements of daily living.

• The Journal of Korean Institute of Next Generation Computing
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• v.14 no.6
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• pp.15-29
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• 2018

This paper proposes an enhanced object tracking algorithm to compensate the lack of temporal information in existing particle swarm optimization based object trackers using the trajectory of the target object. The proposed scheme also enables the tracking and documentation of the location of an online updated set of distractions. Based on the trajectories information and the distraction set, a rule based approach with adaptive parameters is utilized for occlusion detection and determination of the target position. Compare to existing algorithms, the proposed approach provides more comprehensive use of available information and does not require manual adjustment of threshold values. Moreover, an effective weight adjustment function is proposed to alleviate the diversity loss and pre-mature convergence problem in particle swarm optimization. The proposed weight function ensures particles to search thoroughly in the frame before convergence to an optimum solution. In the existence of multiple objects with similar feature composition, this algorithm is tested to significantly reduce convergence to nearby distractions compared to the other existing swarm intelligence based object trackers.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1997.11a
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• pp.259-262
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• 1997

This paper presents a visual servoing of RV-M2 robot manipulators to track and grasp moving object, using pruned dynamic recurrent neural networks(DRNN). The object is stationary in the robot work space and the robot is tracking and grasping the object by using CCD camera mounted on the end-effector. In order to optimize the structure of DRNN, we decide the node whether delete or add, by mutation probability, first in case of delete node, the node which have minimum sum of input weight is actually deleted, and then in case of add node, the weight is connected according to the number of case which added node can reach the other nodes. Using evolutionary programming(EP) that search the struture and weight of the DRNN, and evolution strategies(ES) which train the weight of neuron, we pruned the net structure of DRNN. We applied the DRNN to the Visual Servoing of a robot manipulators to control position and orientation of end-effector, and the validity and effectiveness of the pro osed control scheme will be verified by computer simulations.

• The Korea Journal of Herbology
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• v.38 no.4
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• pp.1-9
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• 2023

Objectives : This study aimed to convert into weight the dosages of flower of Daphne canescens and leaf of Phyllostachys nigra var. henonsis, whose daily dosages are likened to an object in 《Treatise on Cold Damage Diseases》. This study also aimed to understand their implications along with the previously studied gypsium and rhubarb. Methods : After reviewing documents, the dosages were converted into weight, confirmed by experiment, and their implications were considered. Results : A chicken-egg-volume of flowers of Daphne canescens is one Ryang(6.5 g) and two handfuls of leaves of Phyllostachys nigra var. henonsis is four Ryang(13 g). Each item was only used once in a decoction. Their dosages were expressed in weight respectively in 《Supplement to the Essential Prescriptions Worth a Thousand Gold》 and 《Bohenggyuljangbuyongyakbubyo》. Gypsium dosage was expressed in weight except in Daecheongryong-tang as chicken-egg-volume(16 Ryang). To liken a dosage to an object is an exception, as in the three cases above; for precision and convenience it is recommended that dosages be expressed in weight, in which case all three items fell into one of eight categories from one Ryang to 16 Ryang. Rhubarb was measured in weight, but only when using the 12-hour leaching method, four Ryang of rhubarb was cut into of 5-6 wide-go-stone-sized pieces and two Ryang into 5-6 go-stone-sized pieces. Conclusions : To liken a dosage to an object is only an exception and lacks precision and convenience; therefore dosages ended up expressed in weight, count, or volume.

• Journal of Sensor Science and Technology
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• v.15 no.6
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• pp.411-416
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• 2006

This paper describes the development of a 3-axis finger force sensor to grasp an unknown object safely in an intelligent robot's hand. In order to safely grasp an unknown object, robot's hand should measure the weight of an object and the force of grasping direction simultaneous. But, in the published papers, the grippers and hands equippd with the force sensor that could only measure the force of grasping direction, and grasped objects using their sensors. These grippers and hands can't safely grasp unknown objects, because they can't measure the weight of it. Thus, it is necessary to develop 3-axis force sensor that can measure the weight of an object and the force of grasping direction for an intelligent gripper. In this paper, 3-axis finger force sensor to grasp an unknown object safely in an intelligent robot's hand was developed. In order to fabricate a 3-axis finger force sensor, the sensing elements were modeled using parallel plate beams, and the theoretical analysis was performed to determine the size of sensing elements, then the 3-axis finger force sensor was fabricated. Also, the characteristic test of the developed 3-axis finger force sensor was performed.