• Journal of Sensor Science and Technology
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• v.20 no.1
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• pp.25-29
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• 2011

This paper describes the design and analyses of vibration driven electromagnetic energy harvester with high power generation which is suitable for supplying power generator from human body motion. The proposed harvester consists of magnet, coil, and SM (Soft magnetic Material). In order to generate more induced voltage, the SM to concentrate flux lines from end of magnetic poles was arranged into insert moving magnet. Each model was designed and analyzed by using ANSYS software to simulation. The maximum power is generated when load resistance of $1303\;{\Omega}$ is equal to coil resistance. The generated maximum power of for harvesters with SM is $677.85\;{\mu}W$ and 5.46 times higher than without SM at 6 Hz vibration frequency.

• Proceedings of the KIPE Conference
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• 2019.11a
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• pp.182-183
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• 2019

본 논문에서는 외부 환경에 따라 변화하는 태양광 발전의 간헐적 특성을 보완하기 위하여 ESS(Energy Storage System)를 연계하는 시스템을 구현하였다. 또한 태양광 발전의 출력에 따라 태양광 발전과 연계된 ESS를 이용하여 야간에 저장된 에너지를 방전하여 태양광 발전 출력을 일정하게 유지하는 태양광 발전의 일정 출력 추종 알고리즘을 제안하여, 태양광 발전의 간헐적 특성을 보완하였다.

• Culinary science and hospitality research
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• v.7 no.2
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• pp.217-242
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• 2001

A Study on the improvement Method of Domestic Franchise System based on the study through the Dispute cases. Future franchise operating is hard to survive if it has it's own competitive power in the fair trade. So first of all, Headquarter of franchise has the competitive power. Second, it has knowhow, because that knowhow is driving force which can lead a member of franchiser. third, it can supply tableware and materials without a hitch. In the conclusion, franchise operator has the competitive power that are difference and fair trade. Also, when franchiser always cooperate franchise operating, that contributed much to the growth of the foodservice. In the future, the study on foodservice of franchise should be go on more deeply.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.7
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• pp.668-679
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• 1990

The fully digitalized inveter has some difficulties in implementation because of the limitation of available memory capacity and computation time. This paper describes a new PWM(Pulse Width Modulation) Inverter technique which linearizes switching angle characteristics of SHEPWM(Selected Harmonic Eliminatin Pulse Width Modulation) Inverter. Also the detailed description of the scheme along with the realization is presented. The simulation and experimental results show that the proposed schemes have the advantates such as good voltage waveforms and memory-saving.

• Journal of Sensor Science and Technology
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• v.20 no.4
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• pp.249-253
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• 2011

This paper describes the fabrication and characteristics of vibration-driven electromagnetic energy harvester without spring to use at low frequency like a human body motion. The implemented energy harvester consists of NdFeB magnets, copper coil. The optimization of induced voltage was done by the various widths of coil, number of the turns, size of fixed and moving magnets and thicknesses of the cylinder. The fabricated energy harvester is capable of producing up to 15.0 $V_{pp}$ for basic model and 28.80 $V_{pp}$ for improved model at 5.0 Hz resonance frequency and 0.75 g acceleration level. The basic model and improved model are provided a maximum power of 6.375 mWand 25.831 mW at 1 KHz of load resistance in rectifier circuit.

• Safe Food
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• v.6 no.3
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• pp.31-41
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• 2011

• Korean journal of food and cookery science
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• v.2 no.2
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• pp.76-83
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• 1986

Time and temperature, pH and Aw, and microbiological evaluation were made to identify critical control points during various phases in product flow of chicken soup preparation in a university foodservice establishment. The results are summarised as follows: 1) Time and temperature data indicated that the phases of cooling after cooking, post-preparation, and holding ingredients at room temperature before assembly were critical. 2) pH and Aw values were in favorable for microbial growth. 3) Microbiological data indicated that the phases of basic ingredients. post-preparation and holding ingredients before assembly were critical. 4) Critical control points identified were; basic ingredients, cooling after cooking, post-preparation, holding before assembly and service, and assembly and service. 5) Several guidelines were suggested for the effective qualitly control program.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.6
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• pp.433-441
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• 2020

This study proposes a constant power tracking algorithm to compensate for the intermittent characteristics of Photovoltaic connected to a DC micro grid. A PV-ESS integrated module in which distributed ESS is additionally connected is utilized for the proposed algorithm. PV performs P&O MPPT control at all times. To supplement the intermittent characteristics of PV, the proposed constant power tracking algorithm maintains constant power by operating the distributed ESS of the PV-ESS integrated module in accordance with the output state of the PV. By performing PSIM simulation and an experiment, this study verifies the performance of the integrated module of PV-ESS for DC micro grids applying the constant power tracking algorithm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.130-130
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• 2009

This paper describes the temperature characteristics of polycrystalline 3C-SiC micro resonators. The 1.2 ${\mu}m$ and 0.4 ${\mu}m$ thick polycrystalline 3C-SiC cantilever and doubly clamped beam resonators with 60 ~ 100 ${\mu}m$ lengths were fabricated using a surface micromachining technique. Polycrystalline 3C-SiC micro resonators were actuated by piezoelectric element and their fundamental resonance was measured by a laser vibrometer in vacuum at temperature range of $25{\sim}200^{\circ}C$. The TCF(Temperature Coefficient of Frequency) of 60, 80 and 100 ${\mu}m$ long cantilever resonators were -9.79, -7.72 and -8.0 $ppm/^{\circ}C$. On the other hand, TCF of 60, 80 and 100 ${\mu}m$ long doubly clamped beam resonators were -15.74, -12.55 and -8.35 $ppm/^{\circ}C$. Therefore, polycrystalline 3C-SiC resonators are suitable with RF MEMS devices and bio/chemical sensor applications in harsh environments.

• Journal of Korean Academy of Nursing
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• v.50 no.3
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• pp.419-430
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• 2020

Purpose: This study aimed to assess the effect of the emotional coaching program for hospital nurses. Methods: The study used a non-equivalent control group pretest-posttest design, and participants included 60 nurses (30 in the experimental group and 30 in the control group) who worked at a general hospital. The experimental group attended four sessions, one per week, with each session lasting two and a half hours. Collected data were analyzed using descriptive statistics, Fisher's exact test, χ² test, t-test, paired t-test, and repeated measures ANOVA using SPSS WIN 23.0 program. Results: Significant differences were shown between the experimental and the control groups regarding emotional labor (F=68.40, p<.001), resilience (F=48.77, p<.001), and self-efficacy (F=15.31, p<.001). Conclusion: The emotional coaching program for nurses is useful for enhancing nurses' emotional labor management, resilience, and self-efficacy. In addition, this program may serve as a basis for providing emotional coaching to nurses in the future.