• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.97-110
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• 2019

Recently, the 4th Industrial Revolution has been emerged and various products are developed and commercialized in preparation of the communication failure. Many solutions are underway in Back-Up Network for IDC Servers, but not in the personal or sensor for low-power system use. Therefore we used the OpenWRT Firmware in Raspberry Pi which can be easily obtained in online market, and it created a low-power load balancer. Therefore, we developed the device that uses LTE Antenna based on USB Interface for communication fault notification and important data. The equipment used in this paper is easy to buy in online shop for anyone. Also, it can be applied in other vendors' boards by using USB. We hope that this paper will contribute to the stability of individual sensor networks.

• Journal of the Korea Institute of Building Construction
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• v.19 no.2
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• pp.105-112
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• 2019

Fine aggregate made of ferronickel slag(FNS) is similar to natural fine aggregates and is used in concrete structures both domestically and abroad, but its applications and research areas are limited. In this research, in order to expand the availability of FNS and improve the performance of cement mortar products, the applicability of FNS on dry mortar for floor was examined. Experimental results show that FNS improves flow of cement mortar because it has low absorption rate, spherical shape, and glassy surface. Also, the high stiffness of the FNS aggregate itself is considered to contribute to the improvement of cement mortar quality such as crack reduction by improving the compressive strength and shrinkage reducing. In addition, when FNS fine aggregate is applied, it was possible to secure the impact sound insulation performance equal to or higher than that of mortar using natural fine aggregate.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.2
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• pp.208-216
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• 2019

Objective: The aim of this study is to control residual chemicals or by-products generated in chambers during preventive maintenance (PM) in the semiconductor manufacturing industry. We designed local exhaust ventilation using computational fluid dynamics (CFD). Methods: The air flow characteristics and capture efficiency between rectangular and slot hoods were compared numerically. The software Fluent 18.1 was used to estimate uniform velocity distribution and capture efficiency for contaminants. A metal from group 15 in the periodic table was released at the bottom of the chamber to simulate emissions. Results: The slot hood had a higher capture efficiency than a rectangular hood under the same conditions because the slot hood provided uniform air flow and higher face velocity. Also, there was no rotating swirl in the plenum for slot, that is why slot had better efficiency than rectangular even though they had similar face velocity. With less than 10 slots, the capture efficiencies for contaminants were nearly 95%. The optimum conditions for a hood to achieve high efficiency was 8 to 10 slots and a face velocity over 1 m/s. Conclusions: Well-designed ventilation systems must consider both efficiency and convenience. For this study, a slot hood that had high capture efficiency and no work disturbance was designed. This will contribute to protection of the worker's health in a PM area and other areas as well. Also, this study confirms the possibility of the application CFD in the semiconductor fabrication industry.

• Journal of Convergence for Information Technology
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• v.11 no.11
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• pp.288-295
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• 2021

This study was conducted to investigate the effect of end paper adsorbed with mask pack active ingredients on hair during permanent wave treatment. Permanent wave was performed with purchasing mask packs containing green tangerine, collagen, and Houttuynia cordate active ingredients among commercially available mask packs and adsorbing them to the end paper. As experimental methods, hair thickness, hair moisturizing power, tensile strength, hair epidermis observation using SEM, and hair constituent element analysis using EDS were performed. As a result of the experiment, it was confirmed that the experimental group treated with Houttuynia cordate active ingredient on the end paper had a hair protection effect as a result of hair thickness, tensile strength, hair epidermis observation, and hair component analysis. In addition, it was confirmed that the experimental group treated with green tangerine active ingredient on the end paper contained a relatively large amount of moisture in the hair moisturizing power test result. It is hoped that the development and research of various materials and tools will proceed so that basic cosmetic products containing active ingredients can be developed and used as hair cosmetics, and applied during chemical treatment in the industrial field.

• Journal of Korean Society of Water and Wastewater
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• v.35 no.1
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• pp.63-69
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• 2021

Microalgae are primary producers of aquatic ecosystems, securing biodiversity and health of the ecosystem and contributing to reducing the impact of climate change through carbon dioxide fixation. Also, they are useful biomass that can be used as biological resources for producing valuable industrial products. However, harvesting process, which is the separation of microalgal biomass from mixed liquor, is an important bottleneck in use of valorization of microalgae as a bioresource accounting for 20 to 30% of the total production cost. This study investigates the applicability of sewage sludge-derived extracellular polymeric substance (EPS) as bioflucculant for harvesting microalgae. We compared the flocculation characteristics of microalgae using EPSs extracted from sewage sludge by three methods. The flocculation efficiency of microalgae is closely related to the carbohydrate and protein concentrations of EPS. Heat-extracted EPS contains the highest carbohydrate and protein concentrations and can be a best-suited bioflocculant for microalgae recovery with 87.2% flocculation efficiency. Injection of bioflocculant improved the flocculation efficiency of all three different algal strains, Chlorella Vulgaris, Chlamydomonas Asymmetrica, Scenedesmus sp., however the improvement was more significant when it was used for flocculation of Chlamydomonas Asymmetrica with flagella.

• Korean Journal of Metals and Materials
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• v.46 no.8
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• pp.495-505
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• 2008

With the high proportion of zinc coated steels in body-in-white assembly, newly developed surface roughness textured galvannealed steel sheets have been introduced. In this study, zinc coated and surface roughness textured steel sheets were welded by resistance spot welding to investigate its weldability including electrode wear test. Based on the results of tensile-shear test, nugget diameter changes, and electrode tip growth test, it was clear that both surface roughness textured steels (GA-T and GA-E) showed good weldability. Also, there was no large difference in weldability and electrode wear behavior between GA-T and GA-E steels which have different surface roughness morphology. An analysis of electrode degradation showed Fe and Zn penetration through the electrode tip surface at 2400 welds reached $55{\sim}60{\mu}m$ and $75{\sim}80{\mu}m$, respectively. Therefore, there is no significant effect of surface roughness morphology on spot weldability of surface roughness textured galvannealed steel sheets. However, slight difference in thickness of alloying layers existing on electrode tip was found between GA-T and GA-E steels.

• The Journal of Industrial Distribution & Business
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• v.12 no.4
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• pp.35-51
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• 2021

Purpose: As the digital environment has expanded opportunity for consumers to acquire information from social media and social network services(SNS), With this environment, influencer has not only promoted products, but also participated in distribution and influencing on their followers. Despite the increasing interest in influencers, there has not been enough research on the structure of fashion influencer, relationship of immersion and purchase intention. This study examined the effects of fashion influencers' characteristics to the immersion of relationship with followers and purchase intention. Research design, data and methodology: For data collection, a pilot survey and the final survey were conducted. The pilot survey data was conducted to 50 female SNS users following fashion influencers. Based on the pilot tests, questionnaire was revised and the final survey was conducted online from august 22 to September 1, 2019 to female SNS users who have followed fashion influencer. A total of 408 data were collected, and exploratory factor analysis, correlation analysis, and structural equational modeling techniques were employed for the data analyses using AMOS 26.0 and SPSS 26.0. Results: First, five factors were extracted for the fashion influencers' characteristics: interactivity, similarity, reliability, expertise and attractiveness. Second, fashion influences' reliability, expertise, similarity, interactivity have a positive (+) effects on relationship immersion; however, attractiveness has no effect on relationship immersion with followers and fashion influencer. It was also determined that relationship immersion had positive (+) influences on purchase intention. The relationship immersion has been found to have a partially mediated effect and similarity has complete mediated effects between interactivity, reliability, and expertise of fashion influencers and purchasing intentions. In terms of fashion opinion leadership, it was found to have a significant influence on purchase intention only for low fashion leadership groups. Conclusions: The present study found the structural relationships among the influencer characteristics, relationship immersion and purchase intentions to provide framework for succeeding research. This research revealed academic association of intention of purchasing through use of fashion social media and fashion influencer marketing. The results also showed the practical implications that fashion influencers' expertise and reliability perceived by their followers are key determinants to success in influencer marketing.

• Journal of Digital Convergence
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• v.18 no.12
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• pp.59-68
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• 2020

This study aims to present the direction of fostering creative and innovative future design personnel required by companies according to the trend of the times. Changes in design manpower policy and industry, academia, and government cases are examined through policy case studies. Through analysis of industry-academia project cases, we discovered that a new educational model is needed to experience the process of developing products that can be commercialized. This study is expected to be used as basic data for policy development related to program development to foster creative and innovative talents required in the design industry.

• Journal of Korea Foundry Society
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• v.41 no.6
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• pp.543-549
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• 2021

Aluminum cast iron has excellent oxidation resistance and good resistance to sulfide and corrosion. Compared to Ti and Ni alloys, it is expected to be a substitute material for structural materials and stainless steels because it is relatively inexpensive to use Fe, which is a non-strategic element. This results in a weight reduction effect of about 30% as compared to the use of stainless steel. With regard to aluminum as an alloying material, it is an element that has been widely used for the alloying of cast iron in recent years. Practical use has been delayed owing to the resulting lack of ductility at room temperature and the sharp decrease in the strength above 600℃ of this alloy, however. The cause of the weak room temperature ductility is known to be environmental embrittlement by hydrogen, and the addition of various alloying elements has been attempted in order to mitigate these shortcomings. Although alloying elements such as vanadium, chromium, and manganese are mainly used to increase the hardness and wear resistance of gray cast iron, the price of finished products containing these elements and the problems associated with alloys with this material impose many limitations.

• Journal of the Korea Safety Management & Science
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• v.24 no.1
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• pp.31-38
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• 2022

The most common symptoms of COVID-19 are high fever, cough, headache, and fever. These symptoms may vary from person to person, but checking for "fever" is the government's most basic measure. To confirm this, many facilities use thermographic cameras. Since the previously developed thermographic camera measures body temperature one by one, it takes a lot of time to measure body temperature in places where many people enter and exit, such as multi-use facilities. In order to prevent malfunctions and errors and to prevent sensitive personal information collection, this research team attempted to develop a facial recognition thermographic camera. The purpose of this study is to compensate for the shortcomings of existing thermographic cameras with disaster safety IoT integrated solution products and to provide quarantine systems using advanced facial recognition technologies. In addition, the captured image information should be protected as personal sensitive information, and a recent leak to China occurred. In order to prevent another case of personal information leakage, it is urgent to develop a thermographic camera that reflects this part. The thermal imaging camera system based on facial recognition technology developed in this study received two patents and one application as of January 2022. In the COVID-19 infectious disease disaster, 'quarantine' is an essential element that must be done at the preventive stage. Therefore, we hope that this development will be useful in the quarantine management field.