• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.9-17
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• 2009

A Mobile Ad hoc network(MANET) is a network consisting of a set of wireless mobile nodes, which communicate with each other without centralized control or established infrastructure. In this paper, to obtain a better understanding of AODV(Ad hoc On-Demand Distance Vector Routing Protocol)and OLSR(Optimized Link State Routing Protocol) routing protocols, different performances are simulated and analyzed using OPNET modeler 14.5 with the various performance metrics, such as packet delivery ratio, end-to-end delay and routing overhead. As a conclusion, in static analysis, the routing overhead of OLSR is affected by the number of nodes, but not data traffic. In AODV case, it is affected by both data traffic and number of nodes. In mobility analysis, routing overhead is not greatly affected by mobility speed in AODV and OLSR, and the PDR(Packet Delivery Ration) of OLSR is decreased as the node speed increased, while AODV is not changed. AS to delay, AODV is always higher than OLSR in both static and nobility cases.

• Journal of Oral Medicine and Pain
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• v.23 no.3
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• pp.281-288
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• 1998

The authors treated a 30-years old female patient who visited the Department of Oral Medicine, PNUH due to the chief complaint of limitation of mouth opening. The magnetic resonance imaging following clinical examination was used for establishing an accurate and reliable diagnosis and the patient was diagnosed as having anterior disc displacement without reduction in the right joint and anterior disc displacement with reduction in the left joint. For managing acute anterior disc displacement without reduction, mandible manipulation was applied first focusing on pain control and then stabilization appliance was used for maintenance of joint stabilization. With time, the sign and symptom was remarkably reduced and an active exercise program was recommended to maintain of normal muscle length, increase joint range of motion and develop normal coordination arthrokinematics. As a result of treatment, the patient did not complain discomfort of normal daily activities and it was difficult to consider that the displace disc was not reduced completely, but the improvement in range of motion and joint mobility were remarkably found. Therefore, an exercise program should be considered to maintain joint mobility and be effective as a self-care.

• Journal of Korean Vacuum Science & Technology
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• v.4 no.3
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• pp.81-85
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• 2000

The effects of $NH_3$ flow rate and reactor pressure on Al composition and the interface of AlGaN/GaN heterostructure were studied. Equilibrium partial pressure of Ga and Al over AiGaN alloy was calculated as a function of growth pressure, $NH_3$flow rate and temperature. It was found equilbrium vapor pressure of Al is significantly lower than that of Ga, thus, the alloy composition mainly controlled by Ga partial pressure. We believe that more decomposition of Ga occur at lower $NH_3$ flow rate and higher growth pressure leads to preferred Al incorporation into AlGaN. The alloy composition gradient became larger at AlGaN/GaN heterointerface at higher reactor pressures, higher Al composition and low $NH_3$ flow rate. This composition gradient lowered sheet carrier concentration and electron mobility as well. We obtained an AlGaN/GaN heterostructure with sheet carrier density of ${\sim}2{\times}10^{13}cm^{-2}$ and mobility of 1250 and 5000 $cm^2$/Vs at 300 K and 100 K, respectively.

• Journal of Surface Science and Engineering
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• v.54 no.2
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• pp.90-95
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• 2021

Surface modification technique enabling the control of condensation provides various benefit in various engineering systems, such as heat transfer, desalination, power plants, and so on. In this study, lubricant oil-impregnation into Teflon-coated nanoporous anodic oxide layer of aluminum to enhance a de-wetting and mobility of water droplet on surface. Due to the surface treatment improving water-repellency, the condensation mode is changed to dropwise, thus the frequency of sliding condensed water droplet on surface is increased. For these reasons, the surface of oil-impregnated Teflon-coated nanoporous anodic aluminum oxide shows significantly enhanced condensation heat transfer compared to bare aluminum surface. In addition, the porosity of anodic aluminum oxide affected the mobility of water droplet even with oil-impregnation and Teflon-coating, indicating that the optimization of porous structure of anodic oxide is required for maximizing the condensation heat transfer.

• Journal of the Korean Society of Physical Medicine
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• v.14 no.2
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• pp.41-51
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• 2019

PURPOSE: This study was conducted to investigate the effects of combined Joint Mobilization and Functional Electrical Stimulation on Muscle Activation and Mobility of ankle joints in stroke patients and their Modified Functional Reach Test (MFRT) results. METHODS: A total of 26 patients with stroke were randomly selected for enrollment in this study. (1) Functional Electrical Stimulation (FES) (2) combined Joint Mobilization and FES. An EMG system was used to measure tibialis anterior and gastrocnemius activities. Range Of Motion (ROM) of Ankle Joint and MFRT for Dynamic Balance. Pre and post intervention results were compared by paired-t-tests and differences in changes after intervention between groups were identified by the independent t-test. RESULTS: The muscle activation, ROM, and MFRT differed significantly in the experimental group (p<.05). The ROM was significantly different for the active dorsiflexion pre and post intervention in the group that received FES alone (p<.05). CONCLUSION: The results of this study suggest use of a systematic program of proactive posture control to prevent dysfunction when planning interventions for ankle joints can help stroke patients walk efficiently.

• The Korean Journal of Food & Health Convergence
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• v.7 no.4
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• pp.31-41
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• 2021

This study conducted 8 weeks of foam roller & mobility, core, and weight training for 9 middle school soccer players 5 times a week for 90 minutes to determine the effect on changes in body composition, thigh circumference, basic physical strength, and functional movement. To analyze the data according to the results of this study, SPSS 25.0 statistical program was used for analysis, and the mean (M) and standard deviation (SD) were calculated to present the descriptive statistics of all dependent variables. In addition, to analyze the difference between before and after exercise, it was verified using a paired t test. The statistical significance level (α) in all reasoning statistics was set to less than 5%. As a result, there were no significant changes in body composition and thigh circumference through 8 weeks of training. However, there were significant changes in agility and muscular endurance, and the total score for functional movement changes was significantly increased, and statistically significant changes were observed in three variables. Therefore, complex training is effective in changing the physical strength and functional movement of middle school soccer players, and further research will be required for a control group and various complex exercises.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.277-280
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• 2009

Mobile Ad-hoc Network(MANET) could provide the reliable monitoring and control of a variety of environments for remote place. Mobility of MANET would require the topology change frequently compared with a static network. To improve the routing protocol in MANET, energy efficient routing protocol would be required as well as considering the mobility would be needed. In this paper, we propose a new method that the CACH(Context-aware Clustering Hierarchy) algorithm, a hybrid and clustering-based protocol that could analyze the link cost from a source node to a destination node. The proposed analysis could help in defining the optimum depth of hierarchy architecture CACH utilize. The proposed CACH could use localized condition to enable adaptation and robustness for dynamic network topology protocol and this provide that our hierarchy to be resilient.

• Journal of Korea Multimedia Society
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• v.24 no.8
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• pp.1138-1148
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• 2021

In this study, we developed a 'shared-use mobility'-mounted local particulate matter monitoring terminal technology to measure the actual particulate matter concentration around me. As a mobile terminal device in the form of an IoT sensor platform, it is designed to be separated into a control module and a sensor module to minimize interference between sensors and to consider the optimal observation position of each sensor. As a result of the field test, it was confirmed that particulate matter was locally different depending on time and space even within the same area. In addition, it was confirmed that the concentration of particulate matter in the relevant section differed by up to 100 times compared to the surrounding area due to specific sources of particulate matter such as unpaved roads. In addition, we positively reviewed the applicability of the service in the real-time metaverse environment using this result. Through technological advancement and application of multiple shared-use mobilities, we expect to be able to provide new services for practical smart city air environment monitoring, such as localized particulate matter information, air pollution event information, and identification of causes of particulate matter.

• Transactions of Materials Processing
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• v.32 no.2
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• pp.67-73
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• 2023

To overcome a climate change, manufacturing complex-shaped electric mobility parts becomes one of the important issues for enhancing a performance of motor with reducing their weight. Therefore, development of laser-based additive manufacturing shed on light due to their flexible manufacturing capacity that can be suitable to solve the poor formability of Fe-Si alloys for electric mobility parts. Although there are several studies existed to optimize the performance of additively manufactured Fe-Si alloys, the post-annealing effect was not well investigated yet though this is important to control the texture and mechanical properties of additively manufactured parts. In the present work, annealing effect on the mechanical property and microstructure of additively manufactured Fe-4.5Si alloy was investigated. Because of the ordered phase initiation after annealing, the hardness of additively manufactured Fe-4.5Si alloy increased up to 1173 K while a hardness drop occurs at the 1273 K condition due to the micro-crack initiation. The response surface methodology result represents the 1173 K-5 h sample is an optimal condition to maximize the mechanical property of additively manufactured alloy without micro-cracks.

• Journal of Drive and Control
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• v.21 no.1
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• pp.46-52
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• 2024

The advancement of autonomous driving technology has heightened the importance of Autonomous Mobile Robotics (AMR) within smart factories. Notably, in tasks involving the transportation of heavy objects, the consideration of weight in route optimization and path planning has become crucial. There is ongoing research on local path planning, such as Dijkstra, A^*, and RRT^*, focusing on minimizing travel time and distance within smart factory warehouses. Additionally, there are ongoing simultaneous studies on route optimization, including TSP algorithms for various path explorations and on minimizing energy consumption in mobile robotics operations. However, previous studies have often overlooked the weight of the objects being transported, emphasizing only minimal travel time or distance. Therefore, this research proposes route planning that accounts for the maximum payload capacity of mobile robotics and offers load-optimized path planning for multi-destination transportation. Considering the load, a genetic algorithm with the objectives of minimizing both travel time and distance, as well as energy consumption is employed. This approach is expected to enhance the efficiency of mobility within smart factories.