• Journal of Aerospace System Engineering
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• v.17 no.5
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• pp.11-18
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• 2023

The architecture of the Fuel Thermal Management System (FTMS) in a commercial aircraft engine was built to model and simulate the fuel system. The study shows the thermal interactions between the fuel and engine lubrication oil through the mission profile of a high bypass ratio, two-spool turbofan engine. Fuel temperature was monitored as it flowed through each sub-component of the fuel system during the mission. The heat load in the fuel system strongly depended on the fuel flow rate, and was significantly increased for the periods of cruise and descent with decrease of fuel flow rate, rather than for the periods of take-off. Due to the thermal interaction in the pump housing, the fuel temperature at the outlet of the low-pressure pump was increased (4.0, 9.2, and 30.0) % over the case without thermal interaction for take-off, cruise, and descent, respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.198-201
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• 2015

Using Arduino with a pressure sensor to create an interest in modern health care program is aimed. Currently, Korea is estimated that there are 4.2 million people in total incontinence. Through the convergence of Bio Technology and InformationTechnology these patients it is easy and simple to induce urinary incontinence, erectile dysfunction treatment, etc., and to prevent the most effective pelvic floor muscle exercises (Kegel exercises below). The Kegel medical equipments which are currently sold in the market make users exercise by giving electrical stimulations compulsively. Users need to take off their bottoms and take the Femcon therapy in a closed room. This causes various restrictions of time, space and hygiene. This thesis designs a Kegel medical equipment which combines BT and IT, free form restraint in regard to space and hygiene, without the need to take off bottoms.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.201-208
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• 2022

As around the world, ground and underground transportation capacity is reaching its limit, centering on urban areas. As urban traffic becomes congested, time and cost are astronomical, and environmental destruction caused by urban pollution is becoming increasingly serious. As a way to solve this problem, the means of flying over the air are in the spotlight as the next generation of future transportation, and the concept of urban air mobility (UAM, Urban Air Mobility) is defined as systematic planning. The development of an electric-powered vertical take-off (eVTOL) aircraft that obtains electric power through a battery using a personal aerial vehicle (PAV) as a means of transportation has accelerated. As the aircraft development of new technology aircraft in the evtol method is actively carried out, the need to prepare systems such as aircraft certification standards, pilot qualification systems, and qualification management is emerging. The Federal Aviation Administration (FAA) and the European Union Aviation Safety Agency (EASA), which lead international standards, announced new special technical conditions and temporary regulations SCVTOL-01, respectively. However, the pilot qualification system for operating the uam aircraft has not yet been clearly announced. Therefore, this paper analyzes the recently announced FAA regulations and EASA regulations to identify differences and directions in perspectives on UAMs and study the existing vertical take-off and landing aircraft (VTOL) pilot qualification system to present directions for qualification classification.

• Journal of Power Electronics
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• v.7 no.1
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• pp.81-88
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• 2007

This paper presents a new approach to the automatic control of the turn-off angle used to excite the Switched Reluctance Motor (SRM) employed in electric vehicles (EV). The controller selects the turn-off angle that supports and improves the performance of the motor drive system. This control scheme consisting of classical current control and speed control depends on a lookup table to take the best result of the motor. The turn-on angle of the main switches of the inverter is fixed at $0^{\circ}C$ and the turn-off angle is variable depending on the reference speed. The motor, inverter and control system are modeled in Simulink to demonstrate the operation of the system.

• Journal of the Korean Society of Systems Engineering
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• v.19 no.1
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• pp.14-28
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• 2023

The spin-off where the principal technology developers take the lead in the active and initiative pursuit of the commercialization of technologies is increasingly drawing attention, breaking away from the traditional means through the technology transfer or licensing of the public technologies created by the developers. This study aimed to determine the reasons for such differences from the perspective of the institutional theory. The results show that only the start-up support system, profit distribution system for researchers, degree of participation in the technology marketing, entrepreneurship of researchers, the use of start-up systems affected the number of start-ups of spin-off companies. Furthermore, an analysis of success factors and a study on the exploration of success paths for the RSOs will also be required

• Industrial Engineering and Management Systems
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• v.12 no.4
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• pp.351-358
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• 2013

This paper proposes a multiobjective model describing the trade-offs involved in selecting the locations of drop-off boxes for collecting used products and transporting these products to designated locations. We assume the following reverse flow of used products. Owners of used products (cellular phones, digital cameras, ink cartridges, etc.) take them to the nearest drop-off box when the distance is reasonably short. We also assume that owners living closer to drop-off boxes dispose of more used products than do owners living farther from drop-off boxes. Different types of used products are collected, with each type requiring its own drop-off box. A transportation destination for each product is specified. Three objectives are considered: maximizing the volume of used products collected at drop-off boxes; minimizing the cost of transporting collected products to designated locations; and minimizing the cost of allocating space for drop-off boxes. We formulate the above model as a multiobjective integer programming problem and generate the corresponding set of Pareto optimal solutions. We apply the model to an area using population data for Chofu City, Tokyo, Japan, and analyze the trade-offs between the objectives.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.22 no.2
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• pp.67-73
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• 2011

The purpose of licensing system is to ensure that the medicines are examined for safety, efficacy and quality. Nevertheless, off-label or unlicensed drug usages in pediatric practice is widespread in Korea and worldwide. Psychotropics are one of the most commonly used off-label or unlicensed drugs. The most valid approach to face this dilemma will be to have more evidences from pediatric pharmacological studies. Clinicians, in addition, need to monitor closely their off-label or unlicensed drug prescriptions to minimize the trial and error in practice. Researchers should publish their experiences and provide guidelines. Pharmaceutical companies, regulatory authorities, and consumer organizations should endeavor altogether for the children's right to get safe and efficacious drugs as adults do. Here, the definition as well as the current status of off-label and unlicensed drug prescriptions will be introduced. Critical issues regarding the off label drugs are discussed. In addition, I will describe the present condition as to the off-label and unlicensed drugs in child and adolescent psychiatry and the authorization process of off-label drug prescription in Korea. Lastly, direction we should like to take in this field will be mentioned.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.174-174
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• 2001

• Proceedings of the Korean Nuclear Society Conference
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• 2003.05a
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• pp.144-144
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• 2003

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.1
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• pp.54-60
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• 2013

This paper presents a ground altitude determination algorithm using a laser altimeter and GPS for automatic take-off and landing of UAV. The characteristics of the laser altimeter was analyzed in ground tests and a low-pass filter was designed to reduce the effect of signal interruption due to reflectivity problem. The paper shows that a single sensor cannot measure ground altitude appropriately in terms of reliability and accuracy. To complement shortcomings of the laser altimeter, the linear Kalman filter was designed using DGPS vertical speed. Designed filter was validated and tuned through the steps of simulation, ground test and flight test. It was confirmed that the accuracy for automatic landing is achievable.