• Journal of Advanced Navigation Technology
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• v.24 no.5
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• pp.444-449
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• 2020

I proposed small ambulatory robot actuators using piezoelectric benders. In order to make the motion of the biomimetic robot legs similar to the movements of the cockroaches or similar insects, two pairs of legs in the diagonal direction in the four leg structures are required to make the same movement. And elliptical displacement is realized by taking into account horizontal and vertical displacement of multimode oscillations and driving them by electrical signals with differences step by step, for example of 90° the T-shaped robot actuator showed wide range of speed (From 2 mm/sec. up to 266 mm/sec.) and ability of transportation (up to 10 g with 50 mm/s). Locomotive performance of the robot was competitive to the preceding robots, and moreover, the modular type actuators of a segmented myriapods robot could be added and removed for different tasks or performances.

• The Journal of Korean Physical Therapy
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• v.11 no.2
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• pp.43-50
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• 1999

The purpose of this study was to evaluate the change of the energy consumption when loading to leg of the 60persons who don't have past history of cardiopulmonary and neuromuscular disease, To evaluate the change or energy consumption, heart rate was measured in sitting position for 5minute, during walking for 3minute at for 4.8km on treadmill, and during resting state after walking with 1Kg loading to right ankle, and the other 1Kg loading was added to left ankle and then heart rates were measured in the The results were as follow; 1. PCI value without loading to Ankle were significantly increased compared to 1Kg, and 2Kg. (p<0.05) 2. Female Subjects showed mon increased PCI value in without leading and 2Kg loading compared to male subjects. ( p<0.05) 3. When 1Kg ana 2Ka loading to ankle significantly differences were showed between them. (p<0.05) 4. In the case of 1Kg and 2Kg loading, the difference among age groups was observed and the significant difference among PCI, PCI 1kg, PCI 2kg was showed in the only group that is less than 30 years old. 5. In every PCI condition the difference among height groups was observed and the significant difference among PCI conditions was showed in the only group that is less than 165cm. 6. The difference among weight groups in each PCI condition was not observed, but the significant differences among PCI conditions was showed in every group except the group that h from 60kg to 69kg. These results showed that energy consumption was increased according to loading on the ankle during Sate so weight of orthosis or prosthesis met be considered when choosing them and during gait training with these ones.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.2
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• pp.219-225
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• 2015

Because a hydraulic actuator has high power and force densities, this allows the weight of the robot's limbs to be reduced. This allows for good dynamic characteristics and high energy efficiency. Thus, hydraulic actuators are used in some exoskeleton robots and quadrupedal robots that require high torque. Force control is useful for robot compliance with a user or environment. However, force control of a hydraulic robot is difficult because a hydraulic servo system is highly nonlinear from a control perspective. In this study, a nonlinear model was used to develop a simulation program for a hydraulic servo system consisting of a servo valve, transmission lines, and a cylinder. The problems and considerations with regard to the force control performance for a hydraulic servo system were investigated. A force control method using the nonlinear model was proposed, and its effect was evaluated with the simulation program.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.5
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• pp.1038-1046
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• 2017

In this paper, we propose the design of LED Streetlight Platform with capabilities of weather monitoring and color temperature control. Several previous works are focused on the energy efficiency or data management of streetlight system, but no work has been done on the lighting performance, especially when natural phenomenon such as fog or haze appears on the street and obstructs the visibility of drivers and pedestrians. To solve such issue, we propose the use of two LED lamps with different correlated color temperature, which will be activated interchangeably according to the condition on the street. We also present the design of communication scheme between each devices in the system. Moreover, our experimental results show the LED Streetlight Platform can perform well and the data can be displayed properly at the website.

• Journal of the Korean Dietetic Association
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• v.12 no.3
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• pp.277-288
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• 2006

The purpose of this study was to assess the energy expenditure and investigate the relationship between related variables of 57 dieticians in Youngdong-area. The average daily number of steps was found to be 9358.0$\pm$2714.3 steps/day on weekdays and 7862.9$\pm$2504.9 steps/day during weekends. Hourly step rates on weekdays and weekends came to 570.6$\pm$249.8 steps/hr and 564.0$\pm$224.8 steps/hr, respectively. Activity coefficient of subjects was higher on weekdays (1.56) than weekends (1.51, p<0.05). Resting energy expenditure estimated by the Harris-Benedict formula, WHO/NAO/FAO formula as well as formulas based on body surface area and DRIs (Dietary Reference Intake for Koreans) were calculated to be 1333.7$\pm$89.5kcal/day, 1351.0$\pm$123.3kcal/day, 1388.5$\pm$100.3kcal/day and 1295.9$\pm$90.8kcal/day, respectively. Using these resting energy expenditures and the activity coefficients, daily energy expenditures were calculated to be from 2039.7kcal/day to 2183.5kcal/day on weekdays and from 2016.1kcal/day to 2159.2kcal/day on weekends. Meanwhile energy intakes of subjects on weekdays and weekends were 1594.7$\pm$698.3kcal and 2152.9$\pm$768.0kcal, respectively. The activity coefficient (1.49) of dieticians who managed less than 500 meals per day was significantly lower than that of dieticians who served more than 500 meals per day. Dieticians of schools located in rural areas had higher activity coefficient (1.59) than those of schools located in urban or island settings. These results suggest that work analysis and development of management strategies are necessary to improve dieticians' productivity.

• Journal of Intelligence and Information Systems
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• v.8 no.2
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• pp.1-13
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• 2002

In this paper, we propose an object tracking system which can be convinced of moving area shaped on objects through color sequential images, decided moving directions of foot messengers or vehicles of image sequences. In static camera, we suggests a new evaluating method extracting co-occurrence matrix with feature vectors of RGB after analyzing and blocking difference images, which is accessed to field of camera view for motion. They are energy, entropy, contrast, maximum probability, inverse difference moment, and correlation of RGB color vectors. we describe how to analyze and compute corresponding relations of objects between adjacent frames. In the clustering, we apply an algorithm of FCM(fuzzy c means) to analyze matching and clustering problems of adjacent frames of the featured vectors, energy and entropy, gotten from previous phase. In the matching phase, we also propose a method to know correspondence relation that can track motion each objects by clustering with similar area, compute object centers and cluster around them in case of same objects based on membership function of motion area of adjacent frames.

• Journal of Biomedical Engineering Research
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• v.32 no.2
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• pp.79-84
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• 2011

The purpose of this study was to investigate the relevance of the prediction equations derived from the relationship between metabolic energy expenditure and kinetic energy, for different speeds of walking and running over the treadmill. Seven male subjects participated in this study. A tri-axial accelerometer was attached on between the left and right posterior superior iliac spines. Kinetic energy was calculated by the integration of acceleration data and compared with the metabolic energy measured by a gas analyzer. Correlation coefficients were determined to find a relationship between the kinetic energy and the metabolic energy expenditure. Also, the difference between measured and predicted values was used to find the relevance for individual and group equations. Results showed a relatively good correlation between the measured metabolic energy and the calculated kinetic energy. In addition, a dramatic increase in kinetic energy was observed at the transition speed of walking and running (6 km/h). There was no difference in how to predict the kinetic energy expenditure for individual and group even though people have different physical characteristics. This study would be useful to predict metabolic energy expenditures by the regression analysis with acceleration data.

• Korean Journal of Applied Biomechanics
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• v.20 no.4
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• pp.387-393
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• 2010

The purpose of this study was to compare pregnant women's gait parameters and mechanical energies caused by changes in hormone levels and anatomical features such as body mass, body-mass distribution, joint laxity, and musculo-tendinous strength from pregnancy to postpartum. Ten subjects (height: $161{\pm}6.5cm$, mass: $62.7{\pm}10.4\;kg$, $66.4{\pm}9.3\;kg$, $68.4{\pm}7.7\;kg$, $57.2{\pm}7.7\;kg$) participated in the four times experiments (the first, middle, last term and after birth) and walked ten trials at a self-selected pace without shoes. The gait motions were captured with Qualisys system and gait parameters were calculated with Visual-3D. Pregnant women's gait velocities were decreased during the pregnancy periods, but increased after birth. Stride width and cycle time were increased during pregnancy, but decreased after birth. Thigh energy (77.4%) was greater than shank energy (19.06%) or feet (3.54%) about total energy of the lower limbs. Their feet (Left R2=0.881, Right R2=0.852) and shank (Left R2=0.318, Right R2=0.226) energies were significantly increased (positive correlation), but double limb stance time (DLST, R2=0.679) and body total energy (R2=0.138) were decreased (negative correlation) for their velocities. These differences suggest that thigh segment may be a dominant segment among lower limbs, and have something to do with gait velocities. Further studies should investigate joint power and joint work to find energy dissipation or absorption from pregnancy period to postpartum.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.27 no.2
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• pp.55-67
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• 2021

Background: This study aimed to use the muscle energy technique (MET) with total knee replacement (TKR) during the chronic phase in a clinical setting and confirm its effects on the knee extensor strength and ROM, balance, and walking ability. Methods: A total of 20 female patients who underwent TKR 1~4 years ago were assigned to two groups (Control: Q setting exercise+general physical therapy, n=10; Exp: MET+general physical therapy, n=10). Interventions were performed three times a week for 4 weeks. The strength of the knee extensor was evaluated using an aneroid sphygmomanometer, and ROM was evaluated using degrees at the end range on active knee flexion. The main balance outcomes were evaluated using two standard scale (TSS) and timed up and go (TUG) test, whereas the walking ability was evaluated using the 10 meter walk test (10MWT). Results: Analysis showed that both groups had significant increases in strength, ROM, TSS, TUG, and 10MWT. Differences in all variables were significant between the control and Exp groups at the post-intervention evaluation (p<.05). However, no significant difference was observed in strength and TUG. Conclusion: Results of this study demonstrated that MET would help improve the strength, ROM, balance, and walking ability of patients with chronic TKR who want to enhance their abilities and performance in activities of daily living.

• Journal of the Korean Society of Physical Medicine
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• v.19 no.1
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• pp.69-79
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• 2024

PURPOSE: This study compared the effect of the muscle energy technique (MET) and stretching technique on ankle dorsiflexion passive range of motion, balance, and gait ability of stroke patients with limited ankle dorsiflexion. METHODS: Forty-four post-stroke patients participated. The participants were randomized into the MET group (METG; n = 22) and the stretching group (STG; n = 22). The METG was subjected to the MET to relax the dorsiflexion, while the STG was subjected to the dorsiflexion stretching technique. Both groups completed standard neurological physical therapy for 30 min per session. The intervention was conducted five times a week over 3 weeks for a total of 15 times. All participants underwent ankle dorsiflexion passive range of motion measurement and Berg Balance Scale score determination and completed a 10-m walking test and the timed up and go test before and after the intervention. RESULTS: After the 3-week intervention, both groups showed significant improvement after the intervention (p < .05). METG participants showed greater improvements in ankle dorsiflexion passive range of motion and 10-m walking test results compared to STG participants (p < .05). CONCLUSION: Both interventions improved ankle dorsiflexion passive range of motion, balance, and gait ability in stroke patients with limited ankle dorsiflexion. Moreover, the MET was superior to ankle dorsiflexion passive range of motion on the 10-m walking test.