• Journal of Institute of Control, Robotics and Systems
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• v.16 no.10
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• pp.939-947
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• 2010

With the rising numbers of elderly and disabled people, the demand for welfare services using a robotic system and not involving human effort is likewise increasing. This study deals with a mobile-robot system combined with a BWS (Body Weight Support) system for gait rehabilitation. The BWS system is designed via the kinematic analysis of the robot's body-lifting characteristics and of the walking guide system that controls the total rehabilitation system integrated in the mobile robot. This mobile platform is operated by utilizing the AGV (Autonomous Guided Vehicle) driving algorithm. Especially, the method that integrates geometric path tracking and obstacle avoidance for a nonholonomic mobile robot is applied so that the system can be operated in an area where the elderly users are expected to be situated, such as in a public hospital or a rehabilitation center. The mobile robot follows the path by moving through the turning radius supplied by the pure-pursuit method which is one of the existing geometric path-tracking methods. The effectiveness of the proposed method is verified through the real experiments those are conducted for path tracking with static- and dynamic-obstacle avoidance. Finally, through the EMG (Electromyography) signal measurement of the subject, the performance of the proposed system in a real operation condition is evaluated.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.7
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• pp.113-123
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• 2000

In the navigation for a mobile robot, the collision avoidance with unexpected obstacles is essential for the safe navigation and it is independent of the technique used to control the mobile robot. This paper presents a new collision avoidance algorithm using neural network for the safe navigation of the autonomous mobile robot equipped with CAN and ultrasonic sensors. A tracked wheeled mobile robot has a stability and an efficiency to move on a rough ground. And its mechanism is simple. However it has difficulties to recognize its surroundings. Because the shape of the tracked wheeled mobile robot is a square type, sensor modules are generally located on the each plane surface of 4 sides only. In this paper, the algorithm using neural network is proposed in order to avoid unexpected obstacles. The important character of the proposed algorithm is to be able to detect the distance and the angle of inclination of obstacles. Only using datum of the distance and the angle, informations about the location and shape of obstacles are obtained, and then the driving direction is changed. Consequently, this algorithm is capable of real time processing and available for a mobile robot which has few sensor modules or the limited sensing range such as a tracked wheeled mobile robot. Effectiveness of the proposed algorithm is illustrated through a computer simulation and an experiment using a real robot.

• Journal of the Korea Institute of Building Construction
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• v.20 no.4
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• pp.375-382
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• 2020

Rock drop obstacles on major roads in the border area in South Korea has been installed and operated to prevent and block the movement of enemy units. However, the increase in traffic volume due to the development of the border region causes many problems such as road traffic congestion due to rock drop, traffic safety, and impaired urban aesthetics. Therefore, this study aimed to provide guidelines for demolition and replacement facility installation for rock drop obstacles, which are differently applied to each unit, and to suggest the direction of the Ministry of National Defense's policy regarding maintenance cost for necessary rock drop obstacles required for operation. In this study, as part of a guideline study on the removal of rock drop obstacles and the installation of alternative facilities, a standard unit price was suggested for essential rock drop obstacles, so as to be used as judgment data when deciding whether to remove rock drop obstacles.

• Korean Journal of Medicinal Crop Science
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• v.28 no.3
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• pp.209-220
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• 2020

Background: This study investigated the effects of soil properties on the soil fungal community in first and continuous cultivation areas of Cnidium officinale Makino. Methods and Results: The soil fungal community was analyzed for relative abundance and principal coordinate analysis (PCoA) was conducted using Illumina MiSeq sequencing. The correlation between the soil chemical properties and the soil fungal community was assessed with distance-based linear models (DISTLM). The soil fungal community showed distinct clusters consisting in the continuous cultivation area of C. officinale Makino. PCoA and DISTLM indicated that soil pH, calcium, and available P₂O₅ significantly affected the soil fungal community in the cultivation area of C. officinale Makino. In addition, considering 5 different pathogenic fungi the relative abundance of Fusarium in the continuous cultivation area was significantly higher compared to that in the first cultivation area of C. officinale Makino. Conclusions: This study is important because it has determinined the effects of soil properties on the soil fungal community in both first and continuous cultivation areas of C. officinale Makino. Moreover, these results will be helpful to investigate the cause of continuous cropping obstacle in C. officinale Makino by examining the changes of soil fungal community.

• Smart Structures and Systems
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• v.29 no.3
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• pp.499-512
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• 2022

This work proposes a novel contactless vibration damping and thermal isolation tripod platform based on Superconducting Magnetic Levitation (SML). This prototype is suitable for cryogenic environments, where classical passive, semi active and active vibration isolation techniques may present tribological problems due to the low temperatures and/or cannot guarantee an enough thermal isolation. The levitating platform consists of a Superconducting Magnetic Levitation (SML) with inherent passive static stabilization. In addition, the use of Operational Modal Analysis (OMA) technique is proposed to characterize the transmissibility function from the baseplate to the platform. The OMA is based on the Stochastic Subspace Identification (SSI) by using the Expectation Maximization (EM) algorithm. This paper contributes to the use of SSI-EM for SML applications by proposing a step-by-step experimental methodology to process the measured data, which are obtained with different unknown excitations: ambient excitation and impulse excitation. Thus, the performance of SSI-EM for SML applications can be improved, providing a good estimation of the natural frequency and damping ratio without any controlled excitation, which is the main obstacle to use an experimental modal analysis in cryogenic environments. The dynamic response of the 510 g levitating platform has been characterized by means of OMA in a cryogenic, 77 K, and high vacuum, 1E-5 mbar, environment. The measured vertical and radial stiffness are 9872.4 N/m and 21329 N/m, respectively, whilst the measured vertical and radial damping values are 0.5278 Nm/s and 0.8938 Nm/s. The first natural frequency in vertical direction has been identified to be 27.39 Hz, whilst a value of 40.26 Hz was identified for the radial direction. The determined damping values for both modes are 0.46% and 0.53%, respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.224-226
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• 2016

With the technical development and rapid increase of private demand, the new market for unmanned vehicle combined with the characteristics of 'unmanned automation' and 'vehicle' is rapidly growing. Even though the pilot driving is currently allowed in some countries, there is no country that has institutionalized the formal driving of self-driving cars. In case of the existing vehicles, safety incidents are frequently happening due to the frequent malfunction of the rear sensor, blind spot of the rear camera, or drivers' carelessness. Once such minor flaws are complemented, the relevant regulations for the commercialization of self-driving car and small drone could be relieved. Contrary to the ultrasonic and laser sensors used for the existing vehicles, this paper aims to attempt the distance measurement by using the depth sensor. A depth camera calculates the distance data based on the TOF method calculating the time difference by lighting laser or infrared light onto an object or area and then receiving the beam coming back. As this camera can obtain the depth data in the pixel unit of CCD camera, it can be used for collecting depth data in real-time. This paper suggests to solve problems mentioned above by using depth data in real-time and also to design the obstacle avoidance system through distance measurement.

• Journal of Agricultural Extension & Community Development
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• v.18 no.2
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• pp.239-262
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• 2011

The study aims to find development plan of the Hanmadang festival in Jachaebanga village. First of all, Financing is the first major obstacle to opening a successful village festival. In order to host village festival. It's important that smooth financing. It needs head north and diversify of the Banga table. Through proceeding by subscription, research a value-added food the village benefits can be better. Because Jachaebanga village located in capital area. The people who live in Seoul and Gyonggi area easily approachable. So, If induce a free visitors to reservation visitors, It will benefit not only village, but also visitors. Hanmadang festival program and another village festival program are evenly alike. Festival organizers must provide a differentiated festival program to reservation visitors. It needs merge the harvest program and society curriculum to amplify the synergy. Like a Turtle play, participation inducement to neighboring traditional culture organization can be of help to consist festival program. There simply aren't enough people here to progress festival properly. In order to supply people to progress properly, Festival plan, Budgets allocations have to be determined by village officers.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.2
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• pp.264-275
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• 2008

Seven constructs of sanitary management were evaluated in order to examine perceived performance of sanitary management and sanitary recognition for school food service managers in the Kyunggido area. In order to protect from foodborne illness, 331 (58.4%) responded that the most important aspects were sanitary conditions and stability upon food delivery, and the greatest obstacle was limited availability of facilities and equipment (182, 32.2%). The total mean score for the perceived performance of sanitary management was $4.16{\pm}0.445$ (5-point Likert scale). Among three sectors, personal hygiene management was generally well-conducted with a subtotal mean score of $4.52{\pm}0.458$; however temperature management scored lowest with a subtotal mean of $3.71{\pm}0.630$. Chi-square tests were performed according to general characteristics on the two lowest perceived sanitary management performance areas. In temperature management, there was a significant difference in 5 sectors according to age, and the ages $20{\sim}29$ showed the best perceived performance in all sectors. For serving management, a significant difference (p<0.01) was shown in all sectors. In conclusion, foodservice managers perceive that sanitary management is well-executed. However, the combination of proper equipments and facilities would lead to better perceived management.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.3
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• pp.29-37
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• 2009

It is as result that study to apply mini magnet nerve curer in peripheral nervous system disease treatment. Simulator and embodied action power and Control Unit in cylinder form of magnet roof object firstly. Yielded service area about special quality of probe of loop object cylinder style and treatment area dimension and distance of treatment pulse secondly. Embody pulse forming course energy value by Probe's form by third, could embody treatment pulse by disease. Specially, through a special quality experiment, saved Damping pulse form and treatment digital forming etc. variously. Lately, embodied this to aid a little in disease treatment that follow that there is no invasion that there is no stimulation by medicine development. Neuralgia, muscular disease and Altzheimer, with stroke etc. is becoming the matter of concern and interest which disease of adult etc. it is same is important. And the melancholia in compliance with the modern direction of a ceremony which is complicated and garrulous, trillion it will cry and symptoms, it is a tendency where the emotional obstacle etc. nervous psychiatric disorder patient is increasing at class speed. But currently the applicator it will be able to treat like this disease almost it is a condition which is wholly lacking. Consequently like this disease it used magnetic stimulation and it diagnosed and the equipment it will be able to treat plan and it embodied.

• Transactions of Materials Processing
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• v.23 no.8
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• pp.469-474
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• 2014

With the increased concerns of environmental issues, industries are paying more attention to lightweight metals. Because the high degree of springback is an obstacle to the widespread use of lightweight metals, many investigations have been conducted to reduce springback by increasing temperature. However, increasing the temperature of the whole die or the material is energy inefficient, since generally only a limited area of the material is deformed during sheet metal forming. As a solution to this problem, focused heating that only heats the area where plastic deformation occurs may be an alternative approach. In the current study, V-bending tests were conducted at various temperatures after the AZ31, Ti-GR2 sheets were locally heated using near-infrared (NIR) radiation in order to evaluate the effect of temperature on springback. The results of the experiment confirm that the NIR focused heating reduces the springback of AZ31, Ti-GR2 alloys with increasing temperature.