• Aerospace Engineering and Technology
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• 제2권1호
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• pp.153-163
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• 2003

Electronic equipments and make other electronic systems to operate abnormally by means of electromagnetic interference, or can operate abnormally themselves by electromagnetic interference of other electronic systems. Therefore, electronic equipments are required to reduce their electromagnetic interference as small as for other systems to operate properly and operate properly within electromagnetic interference from other electronic systems. In order to prove that electronic equipments meet such requirements, they should undergo electromagnetic environmental test. In this study, we introduce electromagnetic environmental requirements, test procedures and test results of gimbal engine actuation system of KSR-III.

• Journal of Power Electronics
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• 제16권2호
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• pp.498-511
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• 2016

This paper presents a single-phase five-level inverter controlled by two novel pulse width modulation (PWM) switching techniques. The proposed PWM techniques are designed based on minimum switching power loss and minimum total harmonic distortion (THD). In a single-phase five-level inverter employing six switches, the first proposed PWM technique requires four switches to operate at switching frequency and two other switches to operate at line frequency. The second proposed PWM technique requires only two switches to operate at switching frequency and the rest of the switches to operate at line frequency. Compared with conventional PWM techniques for single-phase five-level inverters, the proposed PWM techniques offer high efficiency and low harmonic components in the output voltage. The validity of the proposed PWM switching techniques in controlling single-phase five-level inverters to regulate load voltage is verified experimentally using a 100 V, 500 W laboratory prototype controlled by dspace 1103.

• 대한공업교육학회지
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• 제43권1호
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• pp.58-75
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• 2018

The purpose of this study was to analyze the extent of possession of competence to organize and operate NCS-based curriculum among vocational teachers in specialized vocational high schools, their educational needs and demands. To this end, the questionnaire was used as a research tool. The draft of questionnaires was developed based on the element of competence to organize and operate NCS-based curriculums, and was modified, supplemented through review of four experts in the field of vocational education. The questionnaire survey was done by distributing questionnaires (online) among total 71 vocational high schools located at Gyeonggi-do and collecting 433 questionnaires and then analyzing 340. The findings were as follows. First, whole average of the extent of possession of competence to organize and operate NCS-based curriculums was 3.63. Seen by the average of each area, 'analysis of needs and environment' was 3.59, curriculum organization 3.54, its operation 3.74 and its assessment and feedback 3.57. Second, educational needs for competence to organize and operate NCS-based curriculums of vocational teachers in specialized vocational high schools was 1.47.

• Korean Institute of Interior Design Journal
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• 제19권2호
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• pp.216-224
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• 2010

This study aims to examine a special type of hospital known as Western Oriental medicine treatment designed to provide the best treatment by combining the advantages of Western and Oriental medicine, The actual conditions of the organizations and operations of O.P.D and how the cooperative treatment between Western and Oriental medicine is conducted at general hospitals that operate the cooperative treatment by applying a drawing analysis and an area analysis, and provide materials that help design hospitals that offers the cooperative treatment based on the information. According to the results of this study, the forms of the cooperative treatment between Western and Oriental medicine included several methods; to operate the cooperative center separately between an Oriental hospital and a general hospital, to operate the cooperative hospital, using several floors for an Oriental hospital inside a general hospital, and to operate the cooperative center in specialized centers inside a general hospital and the type of cluster that offers the cooperative treatment in specialized centers is known as the best appropriate treatment.

• Journal of Electrical Engineering and Technology
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• 제6권4호
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• pp.466-473
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• 2011

This paper proposes a protection algorithm for a wind turbine generator (WTG) in a large wind farm. To minimize the outage section, a protection relay for a WTG should operate instantaneously for an internal fault or a connected feeder fault, whereas the relay should not operate for an internal fault of another WTG connected to the same feeder or an adjacent feeder fault. In addition, the relay should operate with a delay for an inter-tie fault or a grid fault. An internal fault of another WTG connected to the same feeder or an adjacent feeder fault, where the relay should not operate, is determined based on the magnitude of the positive sequence current. To differentiate an internal fault or a connected feeder fault from an inter-tie fault or a grid fault, the phase angle of the negative sequence current is used to distinguish a fault type. The magnitude of the positive sequence current is then used to decide either instantaneous operation or delayed operation. The performance of the proposed algorithm is verified under various fault conditions with EMTP-RV generated data. The results indicate that the algorithm can successfully distinguish instantaneous operation, delayed operation, or non-operation depending on fault positions and types.

• Journal of the Korean Society of Systems Engineering
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• 제16권1호
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• pp.25-35
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• 2020

The South Korean Navy is making efforts to acquire vessels that the new technology of the 4th industry is applied, and as a part of these efforts, it has a plan to mount and operate an Unmanned Surface Vehicle(USV) on a vessel that will be introduced later. However, the recent studies have focused on only development of common platforms and mission equipment for the USV, and have not sufficiently analyzed studies and operatinoal requirements on mother ship that will operate the mounted USV. Hence, this study analyzed and presented requirements of mother ship with the mounted USV in order to operate effectively it when the future medium and large vessels to be acquired by the South Korean Navy intent to operate the USV.

• Korean Medical Education Review
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• 제26권1호
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• pp.5-18
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• 2024

The author recommends the creation of a nationwide career guidance program at the national level through the establishment of a long-term cohort, involving collaboration among medical schools nationwide. This cohort would be constructed for the purpose of analyzing correlations from admission to medical school to post-graduate education, facilitating the development of a career guidance program. This will aid in career development through students' self-analysis and competency building. Each medical school should operate a systematic career guidance program. Career guidance for post-graduate major selection should be included in the regular curriculum. Schools are advised to operate student counseling rooms for various career guidance services. For example, medical schools can operate 1:1 career counseling, academic counseling, career guidance surveys, psychological tests, and counseling. It is advisable to establish a mentor-professor system, connect mentor professors, and build a network of experts related to majors to provide immediate support according to students' needs. Professional mentor training should be provided to mentor professors. To provide opportunities for students to experience their career paths in advance, early clinical exposure, long-term integrated clinical practice, community-based clinical practice, participation in student research programs, career fairs, and student internship programs are recommended. In South Korea, it is necessary to systematically operate the internship system and make improvements to facilitate optical career choices. Additionally, considering the significant influence of social factors on students' career choices in South Korea, efforts should be made to identify and address the issues related to these social factors.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.161-164
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• 2008

For the development of solar thermal power tower plant from the early 80' to today, various kinds of receiver have been tested and evaluated. Most of 1st generation receiver used water/steam as a working fluid to operate steam turbine and now the first commercial solar power tower PS-10 also makes saturated steam. However, to increase thermal efficiency of storage system and to obtain practical use of solar energy, molten salt system have been used from THEMIS project in France at 1984. The Solar Tres plant of 17 MWe power generation will be constructed in Spain and have plan to operate 24 hours in summer. The air volumetric receiver system can be integrated with combined cycle of gas turbine and HRSG and also with steam turbine easily. Therefore, related researches to develop higher efficient solar power tower plant and to operate with stable are widely performed in the world.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• 제9권5호
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• pp.51-56
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• 1995

The transistors of single phase 3 level PWM Inverter compose output power transistors and neutral point clamping transistors, which are NPN transistors. Waveforms of driving signals for this are PWM waves for power transistors and period operating waves for neutral point clamping transistors, which signals made W-type modulation from rectangular and sine wave. The output power transistors operate at ON-time complementary and neutral point clamping transistors operate at OFF-time complementary respectively. Therefore, each transistors operate in half period at parallel. Characteristics of this inverter circuit is parallel switching method about series switching method of general inverter. As modulation of 3 level drive signals made from full-wave rectifier of sine wave and rectangular wave, which are level wave about 3 level of complementary transistor inverter. So, this circuit composed complementary operation inverter of NPN transistors only compare with PNP-NPN complementary inverter, which have high power 3 level inverter of complementary operation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.1047-1051
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• 2004

Charge amplifier systems benefit from the very wide dynamic range of PE accelerometers by offering flexibility in adjusting the electrical output characteristics such as sensitivity and range. They are well suited for operation at high temperatures. Modern charge systems feature improved low noise operation, simplified digital controls, and dual mode operation for operation with charge or IEPE voltage mode sensors. high impedance circuitry is not well suited for operation in adverse field or factory environments. The resolution of a PE accelerometer may not be specified or known since noise is a system consideration determined by cable length and amplifier gain. IEPE accelerometrs operate from a constant current power source, provide a high-voltage, low-impedance, fixed mV/g output. They operate through long, ordinary, coaxial cable in adverse environments without degradation of signal quality. They have limited high temperature range. IEPE sensors are simple to operate. Both resolution and operating range are defined specifications. Cost perchannel is lower compared to PE systems since low-noise cable and charge amplifiers are not required.