• Journal of the Korean Applied Science and Technology
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• v.39 no.4
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• pp.527-534
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• 2022

The purpose of this study was to investigate the effects of 12 weeks of muscle power and agility training on physical fitness factors and isokinetic muscle function in elementary school male soccer players. For this purpose, 6 muscle power and agility training programs were organized for 12 elementary school male soccer players and were conducted 3 times a week for 12 weeks. The results of measurement and analysis of physical fitness factors before and after the muscle strength and agility training are as follows. First, there was a significant difference in the standing long jump in place of muscle power(p<.001). Second, there was a significant difference in the standing vertical jump of muscle power(p<.05). Third, there was a significant difference in the side step of agility(p<.01). As a result, 12 weeks of muscle power and agility training can be expected to have a positive effect on the improvement of agility and agility of elementary school male soccer players, and it is judged that it can provide training basic data for injury prevention and performance improvement.

• Journal of the Korean Society of Physical Medicine
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• v.17 no.4
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• pp.65-73
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• 2022

PURPOSE: The present research examined the effects of progressive robot-assisted step training on the strength of the lower extremity and gait speed of an individual with stroke through changes between the baseline and the intervention stage (1, 3, 6, 9, and 12 months). METHODS: A single-subject (A-B) design was performed for a chronic stroke patient aged 70 years old. The robot-assisted step training was conducted three times a week during 12 months (40 minutes/session), and the assessment was conducted a total of seven times between the baseline and the intervention (No. 1, 3, 6, 9, and 12 months) to determine the effect of the intervention. RESULTS: As a result of the intervention, the muscle strength at the lower extremity of the paralysis side increased by the greatest extent 12 months after the intervention compared to the baseline, and the gait speed via the 10-meter walk test was increased as well. CONCLUSION: Long-term robot-assisted step training might be an effective intervention for improving the strength of the paretic lower extremity muscles and gait speed in stroke patients with difficulty walking independently. Further studies with sufficient sample sizes and a randomized control group will be needed to evaluate the long-term effects of robotic stepping rehabilitation.

• Journal of Aerospace System Engineering
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• v.16 no.5
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• pp.86-93
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• 2022

Generally, a deployable solar panel is used primarily to achieve sufficient power output to perform the mission. However, temperature distribution on the antenna reflector may increase due to the shading effect induced by the presence of the deployable solar panels. Appropriate thermal design is critical to minimize the thermal deformation of the mesh antenna reflector in harsh on-orbit thermal environments to ensure remote frequency (RF) performance. In this paper, we proposed a dual-surface primary reflector consisting of a mesh antenna and a flexible fabric membrane sheet. This design strategy can contribute to thermal stabilization by using a flexible solar panel on the rear side of membrane sheet to reduce the temperature distribution caused by the deployable solar panel. The effectiveness of the mesh antenna design strategy investigates through on-orbit thermal analysis.

• Smart Media Journal
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• v.12 no.7
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• pp.76-83
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• 2023

This study proposes a method to assist webtoon artists in the process of webtoon creation by utilizing a pretrained Text-to-Image model to generate webtoon images from text. The proposed approach involves fine-tuning a pretrained Stable Diffusion model using a webtoon dataset transformed into the desired webtoon style. The fine-tuning process, using LoRA technique, completes in a quick training time of approximately 4.5 hours with 30,000 steps. The generated images exhibit the representation of shapes and backgrounds based on the input text, resulting in the creation of webtoon-like images. Furthermore, the quantitative evaluation using the Inception score shows that the proposed method outperforms DCGAN-based Text-to-Image models. If webtoon artists adopt the proposed Text-to-Image model for webtoon creation, it is expected to significantly reduce the time required for the creative process.

• Journal of the Korea Society of Computer and Information
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• v.28 no.7
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• pp.1-9
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• 2023

Currently, as the demand for stops in the urban increases resulting from an increase in the supply of express trains, the development of trains capable of operating both high-floor platforms in the urban and low-floor platforms in the suburbs is required. In this paper, we studied the design and fabrication of a controller for train doors that consists of low and high steps as a plug-in type door mechanism and thus can be used on low and high platforms. This DCU H/W was designed and implemented using 32 bit MCU to control 4 motors, 33 digital inputs and 16 digital outputs. In addition, based on the software life cycle of EN50128, 2 items of operation requirements and 12 items of control requirements were derived, and then they were designed and implemented as operation SW. The implemented SW was tested for each requirement. As a result, we performed tests on 13 items that could be tested in the mock-up out of 14 total requirement items and showed that the requirements were satisfied.

• Journal of Aerospace System Engineering
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• v.17 no.2
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• pp.94-102
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• 2023

A nylon wire holding and release mechanism (HRM) has been widely used for deployable applications of CubeSat owing to its simplicity and low cost. In general, structural safety of solar panel with an HRM has been designed by performing structural analysis under a launch environment. However, previous studies have not performed thermal analysis for HRM in an on-orbit environment. In this study, Launch and Early Orbit Phase (LEOP) thermal analysis was performed to evaluate thermal stability of the mechanism in the orbital thermal environment of the pogo pin-based HRM applied to CubeSat. In addition, the effectiveness of the thermal design and performance of the pogo pin-based HRM were verified through a thermal vacuum test.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.6
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• pp.434-440
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• 2023

This paper propose the method that measure the main system parameters for current control of a.c. motor adopting the vector control technique. The automatical method that tuning PI control gains for current control of servo motors are used frequently through the information of main system parameters, wire resistance and inductance. In this study, the techniques to measure these two system parameters through the control of 3-phase inverter are presented. These control and measuring method are implemented by measuring output phase current obtained as a results of the step current control using simple proportional feedback input. Moreover, this method use freewheeling current of inverter at special switching mode for measuring inductance. This analytic strategy is could measure and calculate the system parameters without the complex measurement algorithm and new additional measuring circuits. That is could measure the total resistance and total inductance including wiring resistance and conduction resistance of switching devices using real driving circuits to control the motors.

• Journal of Aerospace System Engineering
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• v.18 no.2
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• pp.12-20
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• 2024

The application of reinforcement design to ensure the structural safety of electronics in small satellites is limited by the spatial constraints of the satellite structure during launch vibrations. Additionally, a reliable evaluation approach is needed for mounting highly integrated devices that are susceptible to fatigue failure. Although the Steinberg fatigue failure theory has been used to assess the structural integrity of electronic devices, recent studies have highlighted its theoretical limitations. In this paper, we propose a structural methodology based on the critical strain theory to design the digital control unit (DCU) of the X-band SAR payload component for the small SAR technology experimental project (S-STEP), a small satellite constellation. To validate the design, we conducted modal and random analyses using simplified modeling techniques. Based on our methodology, we ultimately demonstrated the structural safety of the electronics through analysis results, safety margin derivation, and functional tests conducted both before and after the launch test.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.7
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• pp.966-974
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• 2010

The aim of this study was to examine characteristics between nutrient intakes, body composition and physical fitness in gifted athletic boys. The subjects were conducted in 50 boys aged 9~12 years living in Busan, Ulsan and Gyeongsangnam-do, Korea. Dietary intake information was collected from participants using 3-day food recorded and body composition was measured by bioelectrical impedance analysis, and their anthropometric parameters were measured. Swimming group's daily energy intakes were significantly higher compared to those of other groups. Athletics and swimming groups were significantly taller than gymnastics. Swimming group was significantly higher than gymnastics group in weight, fat mass, body fat percent and lean body mass. Athletics and swimming groups were significantly longer than gymnastics group in sit and ball throwing. Swimming group was significantly better than other groups in sit up, and athletics group was significantly faster than gymnastics group in 50 m run. In correlation result for nutrient intake and body composition: 1) Body weight shows positive correlation with protein, phosphorus, sodium, vitamin $B_1$, C and niacin. BMI shows positive correlation with sodium and niacin. Fat mass shows positive correlation with niacin and folate. Body fat% shows positive correlation with vitamin C, E, niacin and folate. LBM shows positive correlation with all elements except lipid, calcium, vitamin A, C, E and folate. In correlation result for nutrient intake and physical fitness: 2) Push up shows positive correlation with iron and vitamin C. Sit and throw ball shows positive correlation with the events except lipid, fiber, vitamin A, E and folate. Sit up shows positive correlation with vitamin $B_1$. Half squat shows positive correlation with iron. Standing long jump shows positive correlation with total energy, lipid, and vitamin A, B and $B_2$. Long run shows negative correlation with protein, carbohydrate, fiber, phosphorus, iron, sodium and zinc. Side step shows positive correlation with niacin. Sit and reach shows negative correlation with total energy, carbohydrate, phosphorus, sodium, zinc and vitamin $B_2$. In correlation result for body composition and physical fitness: 3) Sit and throw ball shows positive correlation with body weight, BMI, fat mass, body fat% and LBM. Standing long jump shows positive correlation with LBM. But long run and 50 m run shows negative correlation with body weight and LBM.

• Journal of Environmental Impact Assessment
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• v.30 no.1
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• pp.13-23
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• 2021

In this study, we performed a Random Walker analysis to predict the Major Movement Paths of otters. The scope of the research was a simulation analysis with a radius of 7.5 km set as the final range centered on the Ansim-wetland in Daegu City, and a field survey was used to verify the model. The number of virtual otters was set to 1,000, the number of moving steps was set to 1,000 steps per grid, and simulations were performed on a total of 841 grids. As a result of the analysis, an average of 147.6 objects arrived at the boundary point under the condition of an interval of 50 m. As a result of the simulation verification, 8 points (13.1%) were found in the area where the movement probability was very high, and 9 points (14.8%) were found in the area where the movement probability was high. On the other hand, in areas with low movement paths probabilities, there were 8 points (13.1%) in low areas and 4 points (6.6%) in very low areas. Simulation verification results In areas with high otter values, the actual otter format probability was particularly high. In addition, as a result of investigating the correlation with the otter appearance point according to the unit area of the evaluation star of the movement probability, it seems that 6.8 traces were found per unit area in the area where the movement probability is the highest. In areas where the probability of movement is low, analysis was performed at 0.1 points. On the side where otters use the major movement paths of the river area, the normal level was exceeded, and as a result, in the area, 23 (63.9%), many form traces were found, along the major movement paths of the simulation. It turned out that the actual otter inhabits. The EN-Simulator analysis can predict how spatial properties affect the likelihood of major movement paths selection, and the analytical values are used to utilize additional habitats within the major movement paths. It is judged that it can be used as basic data such as to grasp the danger area of road kill in advance and prevent it.