• Transactions of the Korean hydrogen and new energy society
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• v.25 no.5
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• pp.509-515
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• 2014

At the fuel processing system (FPS) of fuel cell vehicle, hydrogen recirculation blower (HRB) is used for the recirculation of remained hydrogen after reaction. In this paper, noise and vibration improvement of HRB is studied by changing design and control. It is checked the campbell diagram and critical speed for stability of rotor, and housing stiffness is improved using simulation of frequency response function (FRF). A method is suggested that can decrease the unbalance amount of the rotor and impeller which main source of noise and vibration. In order to reduce the noise during deceleration of blower, electrical braking is applied and tested the risk impact of durability. Founded the optimum switching frequency of the motor control, and reduced the idle rpm by increasing of aerodynamic performance. The superiority of paper is proved by measurement of the improved product's noise and vibration.

• Journal of Convergence for Information Technology
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• v.12 no.2
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• pp.142-148
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• 2022

In this paper, the weight reduction design of the yaw gearbox for wind turbine was performed through the finite element analysis method, and the stability was checked by performing the critical speed analysis. The weight reduction product can improve engine efficiency, save parts materials, and earn economic benefits. The yaw gearbox is lightweighted with the goal of achieving a safety rate of 1.3 or higher for wind turbine as indicated by IEC61400-1. In order to reduce the weight of the carrier, a topology optimization method was performed. The safety factor was verified by performing finite element analysis on the carrier. In addition, the housing and carrier were modeled using the finite element method, and the gear train was modeled using MASTA. For the yaw gearbox, the housing and carrier FE model and the gear train model were connected by the partial structural synthesis method to perform the rotational vibration analysis. Vibration excitation sources are mass unbalance and gear mesh frrequemcy, and as a result of the critical speed analysis, it was found that there was no resonance within the operating speed range.

• 지역과문화
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• v.6 no.4
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• pp.23-45
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• 2019

The main research is on how to find source stories and develop and utilize content that will properly show the value of Panmunjom and the surrounding DMZ on the Korean Peninsula, which are receiving worldwide attention. Three methods were used as research for the high-end branding of Panmunjom and the surrounding DMZ. The first is the interest of prospective visitors through the travel cycle, using Joseph Campbell's "The Hero's Journey." The second was to incorporate Roland Bart's "third meaning" into the subjective travel and emotional stimulation, which is the trend of modern travel. The third introduced Kevin Lynch's theory and tried to place five elements of the path, edge, district, node and landmark in the core location of Panmunjom. Through the study, the excavation of contents in Panmunjom and the surrounding DMZ needs to be collected to a third meaning using a direct interview method that listens to the stories of related figures as well as organizing historical events. The priority should be given to those over the age of 80 and interviews should be conducted at least three times and over three generations. The process of building it into an archive, selecting a story, and then going through a culture collage and networking and branding takes place in five stages. This can create a virtuous circle of content processing, content utilization, job creation in the region and revitalizing the local economy through discovery of source stories and storytelling. Content development should be able to touch sensibility while saving time, history, place, originality and sincerity. Taking the center between tourism and travel, development and damage concerns, a careful but long-term plan and large-scale discovery of source stories should be made, and a consensus should be formed on the need for proper storytelling.