• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.1
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• pp.45-49
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• 2011

The aim of study intends to investigate effect of weight of fire-protective clothing for physical balance and agility after maximum physical activity and to provide the base data for the safety of firefighter. For evaluation of static and dynamic-balance, the closed-eyes foot balance and the beam-walking were performed respectively. For evaluation of static and dynamic-agility, the whole body reaction and the side-step were carried out. This study demonstrates that after maximum physical activity, the weight of fire-protective clothing effects on physical static-balance and dynamic-agility and suggests that it could be useful for actual safety field studies of firefighters.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.703-705
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• 2016

In this paper, we developed a wideband PIMD system to measure passive intermodulation distortion signals of mobile communication RF passive module. To represent wideband characteristic, we designed a receiver that meets low-noise and wideband characteristics in RF receiver. It allows high dynamic range in the RF receiver front end. In designed passive intermodulation distortion measurement system, we programed to display a PIMD signal with FPGA/DSP at PC. Implemented PIMD system was variable from 650 MHz to 2700 MHz and show up to -138 dB minimum detectable $3^{rd}$ passive inetrmodulation distortion signal.

• The Journal of Information Systems
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• v.30 no.1
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• pp.179-204
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• 2021

Purpose The purpose of this study is to suggest a research model that shows how Youtube influencers affect consumers' Youtube information adoption and purchase intention. Generally, a communicator's character has a significant effect on the persuasiveness of the message. This study segments influencer characteristics into five dimensions and explores the effect of five characteristics on perceived usefulness of information, perceived enjoyment, information adoption, and purchase intention. Design/methodology/approach This study suggests a structural equation model that explains the casual relationship between the five dimensions of Youtuber characteristics and perceived usefulness of information, perceived enjoyment, information adoption, and purchase intention. Findings There are little research on what and how the characteristics of a Youtube influencer can affect consumers' information adoption and purchase intention of the product. This study is significant in that it provides a research model that examines the effect of Youtuber characteristics on consumers' information adoption and purchase intention. This research discovered that the dimensions of trustworthiness and attractiveness of influencer affect information adoption and purchase intention through the mediate variables.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.4
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• pp.106-112
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• 2021

Thermoplastic microfluidic devices are used in BioMEMS for medical and biotechnology applications, such as gene extraction, DNA analysis, and virus detection. In this research, a simple fabrication protocol with a commercially available pneumatic hot press is proposed and demonstrated for polycarbonate microfluidic devices. Microfluidic channels with a width of 200 ㎛ and a height of 10 ㎛ were designed and machined onto a brass plate as a mold insert using a CNC milling machine. The resulting microfluidic channels on the mold insert were assessed and found to have an actual width of 198 ㎛ and a height of 10 ± 0.25 ㎛. The microfluidic channels were replicated on a polycarbonate sheet using the proposed replication technique at 146℃ for 20 minutes under a constant load of 2400 kgf. The devices were then naturally cooled to 100℃ while maintaining the same pressure. It was found that the microchannels were successfully replicated in the polycarbonate, with a width of 198 ㎛ and a height of 10.07 ㎛. The proposed replication technique thus offers the rapid mass production of high-quality microfluidic devices at a low cost with a process that, unlike conventional photolithography systems, does not require expensive equipment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.578-580
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• 2009

Wireless Sensor Networks(WSNs) has been used for various applications. It is optimized to low power operation than various function and transmission reliability because of limited power by batteries. but it is necessary to guarantee of reliability for using exact data for more diversity purpose. In WSNs environment composed by multi-hop, it is guarantee to end-to-end transmission reliability based hop-by-hop reliability. however, IEEE 802.15.4 standard is not consider link-layer reliability. in this paper, we propose energy efficient Reliable Link-layer Protocol for Wireless Sensor Networks.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.1
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• pp.103-109
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• 2021

Fine chips generated by machining have an impact on machine failure and quality of machined products, it is necessary to remove the chips, so the microchip collection and removal device by rotating conveyor belt with neodymium permanent magnets was developed. In this research, to solve the problem for reducing the existing microchips in the tank, a micro-chip removal device by rotating conveyor belt with neodymium permanent magnets developed. In the development of micro-chip removal device, 3D CATIA modeling was used, and the flow analysis and the electromagnetic force analysis were performed with COMSOL Multiphysics program. To evaluate the performance of the prototypes produced, design of experiments (DOE) is used to obtain the effect of neodymium conveyor movement speed on chip removal for the ANOVA analysis of recovered powders. An experiment was conducted to investigate the effect of the conveyor feed rate on the chip removal performance in detail. As a result of the experiment, it was confirmed that the slower the feeding speed of the fine chip removing device, the more efficient the chip removal.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.5
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• pp.889-898
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• 2022

In this study, sand casting process was applied to manufacture a large aluminum turbo-type fan used for tank powerpack. To apply the sand casting method, the turbo fan was reverse engineered, and after designing three gating systems, the optimal gating system design was selected by performing casting simulation. In the case of the bottom up-gating system, there is a significant temperature loss of the molten alloy during blade filling. When the molten alloy is completely filled into the sand mold, the blade upper tip and front shroud are below the liquidus temperature. In the case of the top down-gating system, molten alloy scattering occurs, but the temperature loss while the blade is filled is smaller than that of the bottom up type. And after the inflow of molten alloy into the mold is completed, the blade upper tip and front shroud are higher than the liquidus temperature. A sand mold was manufactured with the top down-gating system and the casting process was performed. The fan was made perfectly in appearance without any unfilled parts.

• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.638-653
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• 2021

The study intends to understand the meaning of the family in the novel 「Aging Family」. The Novel texts were analyzed from the perspective of In-mo, the main character, using qualitative research methods. Findings show that his family members were non-blood related as well as blood related, and the meaning of his family was changed from a "family with no pride, no affection" to a family with "human affection" and "loyalty stronger than blood". Based on these results, some implications for family social welfare practices were discussed.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.6_2
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• pp.1003-1008
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• 2022

This paper proposes a method related to fault tolerance operation and characteristic analysis of asymmetric 6-phase permanent magnet synchronous motor. In general, motor drive systems with multi-phase structures can be continuously operated despite a reduction of power and speed by using a phase changeover or control techniques according to the failures. As a result, it is widely used in industrial fields such as aviation and defense, which require high efficiency and high reliability. In this paper, the second order ripple of the electrical fundamental freuqnecy occurs in the dq-axis currents of the synchronous coordinate system through mathematical analysis according to the switch open of the dual 3-phase inverter. Therefore, the fault tolerant operation method is presented by applying the fault detection method with a constant cycle for continuous operations. The effectiveness of the proposed fault tolerance operation method is verified through the several experiments.

• Korean Journal of Occupational Health Nursing
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• v.30 no.4
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• pp.196-205
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• 2021

Purpose: This study aimed to identify the factors influencing health-promoting behaviors (HPB) among fish market merchants. Methods: A cross-sectional descriptive design including 117 merchants working at a fish market in city C. Data were collected using self-reported questionnaires during April 19-30, 2021, and were analyzed using descriptive statistics, t-test, ANOVA, Scheffé's test, Pearson correlation coefficients, and stepwise multiple regression analysis with SPSS/WIN 23.0. Results: The scores were 2.68±0.49 for HPB among fish market merchants. Factors significantly influencing HPB among fish market merchants were perceived disabilities (β=-.42, p<.001), self-efficacy (β=.26, p<.001), perceived benefits (β=.16, p=.012), exercise (β=.14, p=.023) and daily working hours (β=-.13, p=.030). These factors accounted for 60.3% of the HPB of fish market merchants. Conclusion: These findings suggest that efforts are needed to reduce perceived disabilities, reduce working hours per day, and develop programs to enhance self-efficacy, perceived benefits, and exercise in order promote HPB among fish market merchants.