• Journal of Aerospace System Engineering
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• v.3 no.4
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• pp.11-18
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• 2009

This paper is about EO sensor module control based on the image processing. The main purpose of this research is acquiring a latitude and longitude of the target located on the ground by using image processing. For image processing, OpenCV is employed which is a computer vision library originally developed by Intel, and ATmega128 is used for the EO sensor module control. This task also involves realization of control programs and acquisition of sensor view angle for the position of the target.

• Journal of Industrial Convergence
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• v.1 no.2
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• pp.17-31
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• 2003

Many risk factors with the onset of Low Back Pain(LBP) have been identified, however, lifting out of Manual Material Handling(MMH) was the most important factor to the LBP. Injuries due to lifting took account for 34.0%(227,291) out of the total overexertion in MMH(668,084). The weight, vertical location, twist angle, lifting frequency, and lifting posture were reviewed in this study. Technical information for using the revised lifting equation to evaluate a variety of two - handled manual material handling tasks was suggested. To measure worker's fatigue in lifting task, Lifting Index Simulator(LIS) was create under the revised NIOSH(National Institute for Occupational Safety and Health) lifting equation. For the implementation of the LIS, data was collected in A company manufactures various paints in Si-Wha industrial complex, Kyunggi-Do. The results of the Lifting Index(LI) were analyzed by MANOVA to find the relation with lifting variables collected. It was found that horizontal distance, vertical distance, travelling distance and frequency were significant at the 0.01 level and weight was significant at the 0.05 level. The purpose of this paper is to reduce the chronical low back pain for the manual material handlers.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.472-473
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• 2013

The growth in number and efficiency of smart devices such as GPS enabled smart phones and PDAs present an unparalleled opportunity for diverse areas of life. However extraction of GPS traces for provision of services demand a huge storage space as well as computation overhead. This is a challenging task especially for the applications which provide runtime services. In this paper we provide a simplified model to extract GPS traces of moving objects at runtime. Road segment partitioning and measure of deviation in angle of trajectory path is incorporated to identify the significant data points. The number of these data points is minimized by our proposed approach in an efficient manner to overwhelm the storage and computation overhead. Further, the competent reconstruction of complete itinerary based on gathered data, is also ensured by proposed method.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.732-735
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• 2020

기존에 지도학습 방법은 성능은 좋지만, 학습할 때 비디오 데이터와 정답 라벨이 있어야 한다. 그러나 이러한 데이터의 라벨을 수동으로 붙여줘야 하는 문제점과 그에 필요한 시간과 돈이 크다는 것이다. 이러한 문제점을 해결하기 위한 다양한 방법 중 자기지도학습(Self-Supervised Learning) 중 하나인 회전 방법을 비디오 데이터에 적용하여 학습하는 연구를 진행하였다. 본 연구에서는 두가지 방법을 제안한다. 먼저 기존의 비디오 데이터를 입력으로 받으면 단순히 비디오 자체를 회전시키는 것이 아닌 입력으로 들어온 비디오의 각각 프레임이 시간이 지나면서 일정한 속도로 회전을 시킨다. 이때의 회전은 총 네 가지 각도[0, 90, 180, 270]를 분류하도록 하는 방법론이다. 두 번째로 비디오의 프레임이 시간이 지나면서 변할 때 프레임 별로 고정된 각도로 회전시키는데 이때 회전하는 속도 네 가지 [1x, 0.5x, 0.25x, 0.125]를 분류하도록 하는 방법론이다. 이와 같은 제안하는 pretext task들을 통해 네트워크를 학습한 뒤, 학습된 모델을 fine tune 시켜 비디오 분류에 대한 실험을 수행 및 결과를 도출하였다.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.5
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• pp.487-495
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• 2012

In this paper, a Smart Home Service Robot, McBot II, which performs mess-cleanup function etc. in house, is designed much more optimally than other service robots. It is newly developed in much more practical system than McBot I which we had developed two years ago. One characteristic attribute of mobile platforms equipped with a set of dependent wheels is their omni- directionality and the ability to realize complex translational and rotational trajectories for agile navigation in door. An accurate coordination of steering angle and spinning rate of each wheel is necessary for a consistent motion. This paper develops trajectory controller of 3-wheels omni-directional mobile robot using fuzzy azimuth estimator. A specialized anthropomorphic robot manipulator which can be attached to the housemaid robot McBot II, is developed in this paper. This built-in type manipulator consists of both arms with 4 DOF (Degree of Freedom) each and both hands with 3 DOF each. The robotic arm is optimally designed to satisfy both the minimum mechanical size and the maximum workspace. Minimum mass and length are required for the built-in cooperated-arms system. But that makes the workspace so small. This paper proposes optimal design method to overcome the problem by using neck joint to move the arms horizontally forward/backward and waist joint to move them vertically up/down. The robotic hand, which has two fingers and a thumb, is also optimally designed in task-based concept. Finally, the good performance of the developed McBot II is confirmed through live tests of the mess-cleanup task.

• Korean Journal of Applied Biomechanics
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• v.19 no.4
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• pp.647-653
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• 2009

The purpose of this study was to investigate the differences between female and male ballet dancers in anterior cruciate ligament injury risk factors during the box drop landing task. Nine female and nine male collegiate ballet dancers participated in this study. Kinematic and ground reaction data were collected and combined with inverse dynamics to estimate the knee extensor and abductor moment. EMG data from the biceps femoris and rectus femoris were used to estimate the ratio of quadriceps-hamstrings muscle activity. No gender differences in anterior cruciate ligament injury risk factors were found during the box drop landing task. A significant relationship was found between female and male ballet dancers in the knee flexion angle.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.10
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• pp.839-846
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• 2016

Bin picking is a task of picking a small object from a bin. For accurate bin picking, the 3D pose information, position, and orientation of a small object is required because the object is mixed with other objects of the same type in the bin. Using this 3D pose information, a robotic gripper can pick an object using exact distance and orientation measurements. In this paper, we propose a 3D vision technique for accurate measurement of 3D position and orientation of small objects, on which a paper label is stuck to the surface. We use a maximally stable extremal regions (MSERs) algorithm to detect the label areas in a left bin image acquired from a stereo camera. In each label area, image features are detected and their correlation with a right image is determined by a stereo vision technique. Then, the 3D position and orientation of the objects are measured accurately using a transformation from the camera coordinate system to the new label coordinate system. For stable measurement during a bin picking task, the pose information is filtered by averaging at fixed time intervals. Our experimental results indicate that the proposed technique yields pose accuracy between 0.4~0.5mm in positional measurements and $0.2-0.6^{\circ}$ in angle measurements.

• Korean Journal of Cognitive Science
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• v.22 no.4
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• pp.385-404
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• 2011

We examined how emotional background stimuli influence focused attention in a flanker task. An IAPS picture was presented for 1,000ms in advance, then a target and two flanker letters were presented against the IAPS picture for 200ms(Experiment 1). The flanking stimuli were simultaneously presented on the left and right sides of the target stimulus with distance of $0.5^{\circ}C$, $1^{\circ}C$, or $1.5^{\circ}C$ visual angle. We investigated the flanker compatibility effect that identification of target would be faster when they were flanked by identical(compatible) stimuli than when they were flanked by different(incompatible) stimuli. Results of Experiment 1 revealed that the flanker compatibility effect depended not only on the distance of flankers but also on the valence of a background IAPS pictures. Positive and neutral pictures showed distance effect that the flanker compatibility effect was decreased as the farther the distance was, while negative pictures showed no di stance effect. Positive and neutral pictures showed compatibility effects at all distance conditions, but negative pictures didn't showed compatibility effect at $1.5^{\circ}C$ distance condition. In Experiment 2, the SOA(Stimulus Onset Asynchrony) between the picture and the stimuli of flanker task was manipulated. The flanking stimuli were presented simultaneously on the left and right sides of the target stimulus with a distance of either $0.5^{\circ}C$ or $1.5^{\circ}C$ visual angle. The results of Experiment 2 showed that flanker compatibility effect depends on SOA. At long SOA(2800ms), negative pictures showed no distance effect, but positive or neutral pictures did. All valence conditions of background pictures showed compatibility effects at $0.5^{\circ}C$ distance condition, but didn't showed compatibility effect at $1.5^{\circ}C$ distance condition. At short SOA(100ms), all valence conditions of background pictures showed distance effect, and showed compatibility effects with the exception of negative background pictures at $1.5^{\circ}C$ distance condition. These findings suggest that the scope of visual attention becomes narrower when viewing negative emotional stimuli and becomes broadened when viewing positive emotional stimuli. The narrowed scope of attention in negative emotion lasts longer, while the broaden scope of attention in positive emotion lasts shorter.

• Physical Therapy Korea
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• v.10 no.3
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• pp.63-70
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• 2003

The purpose of this study was to compare the difference of joint position sense between measurements. Fourteen healthy male subjects were recruited for this study. The elbow joint position senses were measured using angle reproduction test. The elbow joint position sense was assessed with three experimental conditions: ipsilateral reproduction test in open-chain condition, contralateral reproduction test in open-chain condition, ipsilateral reproduction test with weight in open-chain condition and ipsilateral reproduction test in closed-chain condition. The angular difference between stimulus position and the reproduced position (angular error) was calculated in all testing conditions to examine the accuracy of the joint position sense. One way ANOVA was used to compare the error angles in all experimental conditions. The error angles between measurements were significantly different in elbow joint. The error angles was smallest in ipsilateral reproduction test with weight in open-chain condition and was greatest in the contralateral reproduction test in open-chain condition. Findings of this study indicate that testing methods, types of task, existence of resistance should be considered in clinical assessment for the joint position sense.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.3
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• pp.41-47
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• 2016

PURPOSE: Forward head posture (FHP) is one of the most common postural problems among white-collar workers who perform highly repetitive tasks in the same position. The aim of this study was to research the effects of thoracic and lumbar support fixtures on forward head posture (FHP) during visual display terminal (VDT) work. METHODS: The subjects were 36 healthy male students with no problems in their medical history or respiratory systems. The subjects were randomly assigned to three groups: control group (n=12), thoracic support fixtures (n=12), and lumbar support fixtures (n=12). We conducted a text typing task of the same content for 20 minutes, and evaluated the angles, including the craniovertebra angle (CVA), craniorotation angle (CRA) with photogrammetry. RESULTS: The thoracic and lumbar support fixture groups showed a statistically significant difference at the CVA and CRA to the control group (p<.05), and the post-hoc test showed an increase of the CVA and decrease of the CRA than the control group. However, when we compared the effects of thoracic and lumbar support fixtures on FHP, there was no significant difference in the difference in decrease of the CVA or increase of the CRA (p>.05). CONCLUSION: We determined that VDT work using thoracic and lumbar support fixtures has a positive effect on forward head posture in white-collar workers. Further studies are required to find the more effective location of support fixtures.