• Journal of Biomedical Engineering Research
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• v.29 no.1
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• pp.32-39
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• 2008

This paper reports on a realtime OS based master-slave configuration robot control system for laparoscopic surgery robot which enables telesurgery and overcomes shortcomings with conventional laparoscopic surgery. Surgery robot system requires control system that can process large volume information such as medical image data and video signal from endoscope in real-time manner, as well as precisely control the robot with high reliability. To meet the complex requirements, the use of high-level real-time OS (Operating System) in surgery robot controller is a must, which is as common as in many of modem robot controllers that adopt real-time OS as a base system software on which specific functional modules are implemened for more reliable and stable system. The control system consists of joint controllers, host controllers, and user interface units. The robot features a compact slave robot with 5 DOF (Degree-Of-Freedom) expanding the workspace of each tool and increasing the number of tools operating simultaneously. Each master, slave and Gill (Graphical User Interface) host runs a dedicated RTOS (Real-time OS), RTLinux-Pro (FSMLabs Inc., U.S.A.) on which functional modules such as motion control, communication, video signal integration and etc, are implemented, and all the hosts are in a gigabit Ethernet network for inter-host communication. Each master and slave controller set has a dedicated CAN (Controller Area Network) channel for control and monitoring signal communication with the joint controllers. Total 4 pairs of the master/slave manipulators as current are controlled by one host controller. The system showed satisfactory performance in both position control precision and master-slave motion synchronization in both bench test and animal experiment, and is now under further development for better safety and control fidelity for clinically applicable prototype.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.549-566
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• 2022

Recently, artificial intelligence (AI) technology has progressed rapidly, and industries using this technology are significantly increasing. Further, analysis research using text mining, which is an application of artificial intelligence, is being actively developed in the field of social science research. About 125 laws, including joint laws, have been enacted under the Ministry of Oceans and Fisheries in various sectors including marine environment, fisheries, ships, fishing villages, ports, etc. Research on the laws under the Ministry of Oceans and Fisheries has been progressively conducted, and is steadily increasing quantitatively. In this study, the domestic research trends were analyzed through text mining, targeting the research papers related to laws of the Ministry of Oceans and Fisheries. As part of this research method, first, topic modeling which is a type of text mining was performed to identify potential topics. Second, co-occurrence network analysis was performed, focusing on the keywords in the research papers dealing with specific laws to derive the key themes covered. Finally, author network analysis was performed to explore social networks among authors. The results showed that key topics have been changed by period, and subjects were explored by targeting Ship Safety Law, Marine Environment Management Law, Fisheries Law, etc. Furthermore, in this study, core researchers were selected based on author network analysis, and the tendency for joint research performed by authors was identified. Through this study, changes in the topics for research related to the laws of the Ministry of Oceans and Fisheries were identified up to date, and it is expected that future research topics will be further diversified, and there will be growth of quantitative and qualitative research in the field of oceans and fisheries.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.1
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• pp.1-8
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• 2016

In this study, we propose a control algorithm for Inertially Stabilized Platforms (ISP), which combines Disturbance Observer (DOB) with conventional proportional integral derivative (PID) control algorithm. A single axis ISP system was constructed using a direct drive motor. The joint friction was modeled as a nonlinear function of joint speed while the accuracy of the model was verified through experiments and simulation. In addition, various Q-filters, which have different orders and relative degrees of freedom (DOF), were implemented. The stability and performance of the ISP were compared through experimental study. The performance of the proposed PID-plus-DOB algorithm was compared with the experimental results of the conventional double loop PID control under artificial vehicle motion provided motion simulator with six DOF.

• Tunnel and Underground Space
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• v.9 no.4
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• pp.350-363
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• 1999

The precision cyclic shear test system was established to investigate the mechanical characteristics of rough rock joints under cyclic loading conditions. Laboratory cyclic shear tests were conducted for saw-cut joints and artificial rough rock joints using Hwangdeung granite and Yeosan marble. Surface roughness and aperture characteristics of specimens were examined by measuring surface topography using the laser profilometer. Peak shear strength, phase difference during loading and unloading, and anisotropic shear behavior were investigated throughout the cyclic shear test results. These features and their subsequent variations in each loading cycle are significantly dependent upon the second order asperities and the strength of intact rock. It was observed that degradation of asperities for rough rock joints under cyclic shear loading followed the exponential degradation laws of asperity angle and that the mechanism for asperity degradation would be different depending upon the normal stress level, roughness of joint surface and the loading stage.

• Journal of radiological science and technology
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• v.41 no.5
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• pp.413-419
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• 2018

Magnetic Resonance Imaging for patients with metallic implant has poor image quality, and signal loss and artifacts including distortion can occur. The purpose of this study is to carry out a comparative evaluation on high receive bandwidth(hiBW), O-MAR, O-MAR XD to reduce artifacts in knee implant. To take MRI, 3.0T scanner and dual-source radiofrequency transmission were used. O-MAR XD technique's strong option showed a significant difference (p<0.001) with O-MAR XD technique's weak option, O-MAR and hiBW excluding the medium option. O-MAR XD's medium option had a significant difference (p<0.01) with O-MAR XD's weak, O-MAR and hiBW. O-MAR XD technique's weak option had a significant difference (p<0.01) with O-MAR XD's strong and medium options, O-MAR and hiBW. O-MAR technique had a significant difference (p<0.001) with strong, medium, weak options of O-MAR XD technique except for hiBW. HiBW had a significant difference (p<0.001) with strong, medium and weak options of O-MAR XD technique except for O-MAR. The results showed that O-MAR XD technique was more useful for MRI scan for patients with knee replacement surgery than traditional techniques such as hiBW or O-MAR, and susceptibility artifacts decreased more when O-MAR XD technique's strong or medium option was applied. Based on the results above, it is considered that it will be possible to acquire images whose susceptibility artifacts were highly decreased by using O-MAR XD technique's strong or medium option when conducting MRI for artificial knee joint and it will be helpful for checking and monitoring patients with knee joint replacement.

• Journal of the Korea Computer Industry Society
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• v.3 no.12
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• pp.1651-1658
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• 2002

Recently power cable used generally in Korea, because installation is very simple and it has high stability. It confirms to the requirements of IEEE std. 404-1993 by factory testing, but many problems of insulated cable systems are caused by internal defects of the joint part which have to be mounted ensile. Especially, fault rates are arise from impurities or voids. A suitable solution for a monitoring of power cable during the after-laying test and service is partial discharge detection. The artificial defects between cable joint(EPR) and insulator(XLPE) interface are considered in this research to investigating the partial discharge characteristics. ${\varphi}$-q-n properties were detected using data acquisition system and Maximum charge($q_{max}$), repetition rate(${\={n}$), average charge(${\={q}$), Unbalance rate of ${\={n}$ and ${\={q}$ are calculated in order to analysis partial discharge properties quantitatively from this statistic value.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.4
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• pp.283-289
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• 2014

This paper presents a design and optimization of the fully-active transfemoral prosthesis leg system. As it has one degree of freedom in knee joint, this prosthesis leg can imitate the human's gait. The weight of system, which makes the users more comfortable due to less tiredness, and the knee joint torque to rise stability of the system are major factors of prosthesis leg system. Thus the mechanism of prosthesis changes from 3-linkage type to geared type. The sensorized foot is also designed to effectively determine human's gait by measuring deformation of the foot during gait. Topology optimization is carried out for the sensorized foot to remove its unnecessary weight. The safety of optimized foot is verified by carrying out finite element analysis.

• Journal of Broadcast Engineering
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• v.27 no.5
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• pp.718-727
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• 2022

The Korean domestic cartoon industry has grown explosively by 65% compared to the previous year. Then the market size is expected to exceed KRW 1 trillion. However, excessive work results in health deterioration. Moreover, this working environment makes the production of human resources insufficient, repeating a vicious cycle. Although some tasks require creation activity during cartoon production, there are still a lot of simple repetitive tasks. Therefore, this study aimed to develop a method for creating a character pose through human pose estimation (HPE). The HPE is to detect key points for each joint of a user. The primary role of the proposed method was to make each joint of the character match that of the human. The proposed method enabled us to create the pose of the two-dimensional cartoon character through the results. Furthermore, it was possible to save the static image for one character pose and the video for continuous character pose.

• Journal of muscle and joint health
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• v.30 no.3
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• pp.179-188
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• 2023

Purpose: This study was conducted to investigate the prevalence and related factors of metabolic syndrome in postmenopausal adult women in South Korea. Methods: Data of 678 postmenopausal adult women aged 19 to 64 were collected from the Eighth Korea National Health and Nutrition Examination Survey in 2021 and analyzed by a complex sampling design using SPSS 20.1. Results: The prevalence of metabolic syndrome in postmenopausal adult women was 25.8%. The prevalence was 1.93 times (confidence interval [CI]=1.15~3.25, p=.014) higher for high school graduates, 2.55 times (CI=1.33~4.91, p=.005) higher for middle school graduates, and 2.90 times (CI=1.36~6.15, p=.006) higher for elementary school graduates, compared to college graduates. It was found that artificial menopausal women had 2.74 times (CI=1.18~6.38, p=.020) higher prevalence than natural menopausal women. In addition, women who perceived their health as bad were 1.90 times (CI=1.14~3.16, p=.014) higher than women who perceived their health as good, and women who did not muscle exercise more than twice a week had 1.87 times (CI=1.05~3.34, p=.034) higher prevalence than women who did muscle exercise. Conclusion: Therefore, in order to effectively prevent and manage metabolic syndrome in postmenopausal adult women, a focus must be placed on vulnerable groups to manage these factors.

• Physical Therapy Rehabilitation Science
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• v.13 no.2
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• pp.152-162
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• 2024

Objective: This study was conducted to analyze the effect of wearable Electromyography-controlled functional electrical stimulation (EMG-controlled FES) System on Gait Function and cardiopulmonary metabolic efficiency during walking in older adults. Design: Cross-section study Methods: Total 22 older adult participants suitable to selection criteria of this study participated in this study. The EMG-controlled FES System, which functions as a wearable physical activity assist FES system was used. All participations performed randomly assigned two conditions (Non-FES assist [NFA], FES assist [FA]) of walking. In all conditions, spatio-temporal parameters and kinematics and kinetics parameters during walking was collected via 3D motion capture system and 6 minutes walking test (6MWT) and metabolic cost during walking and stairs climbing was collected via a portable metabolic device (COSMED K5, COSMED Srl, Roma, Italy). Results: In Spatio-temporal parameters aspects, The EMG-controlled FES system significantly improved gait functions measurements of older adults with sarcopenia at walking in comparison to the NFA condition (P<0.05). Hip, knee and ankle joint range of motion increased at walking in FA condition compared to the NFA condition (P<0.05). In the FA condition, moment and ground reaction force was changed like normal gait during walking of older adults in comparison to the NFA condition (P<0.05). The EMG-controlled FES system significantly reduced net cardiopulmonary metabolic energy cost, net energy expenditure measurement at stairs climbing (P<0.05). Conclusions: This study demonstrated that EMG-controlled FES is a potentially useful gait-assist system for improving gait function by making joint range of motion and moment properly.