• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2016년도 추계학술대회 논문집
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• pp.189-189
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• 2016

In this study, the Al-rich AlTiSiN thin films that consisted of TiN/AlSiN nano-multilayers were deposited on the steel substrate by magnetron sputtering, and their high-temperature oxidation behavior was investigated, which has not yet been adequately studied to date. Since the oxidation behavior of the films depends sensitively on the deposition method and deposition parameters which affect their crystallinity, composition, stoichiometry, thickness, surface roughness, grain size and orientation, the oxidation studies under various conditions are imperative. AlTiSiN nano-multilayer thin films were deposited on a tool steel substrate, and their oxidation behavior of was investigated between 600 and $1000^{\circ}C$ in air. Since the amount of Al which had a high affinity for oxygen was the largest in the film, an ${\alpha}-Al_2O_3-rich$ scale formed, which provided good oxidation resistance. The outer surface scale consisted of ${\alpha}-Al_2O_3$ incoporated with a small amount of Ti, Si, and Fe. Below this outer surface scale, a thin ($Al_2O_3$, $TiO_2$, $SiO_2$)-intermixed scale formed by the inwardly diffusing oxygen. The film oxidized slower than the $TiO_2-forming$ kinetics and TiN films, but faster than ${\alpha}-Al_2O_3-forming$ kinetics. During oxidation, oxygen from the atmosphere diffused inwardly toward the reaction front, whereas nitrogen and the substrate element of iron diffused outwardly to a certain extent.

• 가정과삶의질연구
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• 제27권2호
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• pp.11-28
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• 2009

This study is intended to make a tool which can identify how consumers consume by presenting a concept of "consumption style" and by developing the scale to measure it. In order to study the scope and meaning of consumption for modern consumers, "the meaning of consumption" was theoretically considered. Based on it, the concept and perspective of 'consumption style'was formed and then the scale for measuring it was developed. To develop the scale, the scale was formed by extracting questions through a literature survey, and verifying validity through experts' opinion. Then, the final scale was developed by conducting a questionnaire survey for consumers. A preliminary 150- item scale was developed through a literature review. 1000 consumers responded to an online survey using the preliminary scale. This research was made with the intention of not only supplying the academic data on the consumer's "consumption style" but also understanding the consumer's basic behavior patterns. Then A series of tests, such as test-retest, item-to-total correlation, Cronbach's reliability coefficient and factor analysis, were conducted using the survey data. The final scale with 68-items was constructed in the end. The "consumption style" Scale for Consumers consisted of 4 factors.

• KIEAE Journal
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• 제17권1호
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• pp.37-42
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• 2017

Purpose: Various landscapes have been created in the process of changing containers, which were a tool of trade activities, to architecture, and today, containers have formed relationships with people as complex facilities and constantly create new cultures. In this paper, considering these container constructions from the viewpoint of the landscape, consider the meaning as one of landscape factors for creating cultural landscape. Method: In this study, a methodological framework was constructed based on various statistical data and literature materials, and analyzed texts called containers from the viewpoints of physical elements and active elements and analyzed them at the level of function. Based on literature materials, specifically, this study has handled with the cultural landscape as text, the functional dimension of urban design, and the characteristics of container construction. Result: This research analyzed the physical and active characteristics of the target area by utilizing the content of the field analysis and the contents of the interview, previous research, etc., and then content was analyzed in functional dimension. Through this process, the conclusion proposed by this research is to study the construction of a container and present the direction to analyze in the functional dimension showing the landscape characteristics that it brings forward.

• 한국정밀공학회지
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• 제24권8호통권197호
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• pp.34-40
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• 2007

In this study, focusing on reducing a load in forming helical gears, the extrusion using two-step processes for manufacturing helical gear is proposed. The process is composed of the extrusion step in which spur gear to be used as a preform in next step is formed, and the torsion step in which the preform of spur gear is formed to helical gear. Upper-bound theory for the two-step process is applied and compared with the results of experiment. The result of upper-bound solution has a good agreement with that of the experiment and the FE analysis. The newly proposed method can be used as an advanced forming technique to remarkably reduce a forming load, to prolong a tool life, and to replace the conventional forming process of helical gears. Results obtained from the extrusion using two-step processes enable the designer and manufacturer of helical gear to be more efficient in this field.

• Journal of Welding and Joining
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• 제30권5호
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• pp.34-39
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• 2012

This study was conducted to investigate the microstructure and mechanical properties of friction stir lap joints. Invar 42 and SS 400 were selected as the experimental materials, and friction stir welding was carried out at a tool rotation speed of 200 rpm and welding speed of 100 mm/min. The application of friction stir welding to Invar 42 effectively reduced the grain size in the stir zone; the average grain size of Invar 42 was reduced from $11.5{\mu}m$ in the base material to $6.4{\mu}m$ in the stir zone, which resulted in an improvement in the mechanical properties of the stir zone. The joint interface between Invar 42 and SS 400 showed a relatively sound weld without voids and cracks, and the intermetallic compounds with $L1_2$ type in lap jointed interface were partially formed with size of 100 nm. Moreover, the hook in the advancing side of Invar 42 was formed from SS 400, which contributed to maintenance of the tensile strength. The evolution of microstructures and mechanical properties of friction stir lap jointed Invar 42 and SS 400 are also discussed herein.

• 가정과삶의질연구
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• 제28권6호
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• pp.207-220
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• 2010

This study is intended to create a tool which can identify the concept of consumption life level and to develop a standardized scale to measure consumption life level. Based on it, the concept and perspective of consumption life level was formed and then the scale for measuring it was developed. To develop the scale, the scale was firstly formed by extracting questions through a literature survey, and verifying validity through experts' opinions. Then the final scale was developed by conducting a questionnaire survey for consumers. A preliminary 27-item scale was developed through a literature review. 1000 consumers responded to an online survey using the preliminary scale. This research was made with the intention of not only supplying academic data on the consumer's consumption life level but also understanding the consumer's basic behavior patterns. Then a series of tests: test-retest, item-to-total correlation, and Cronbach's reliability coefficient and factor analysis were conducted using the survey data and the final 20-item scale was constructed in the end. The consumer's consumption life level scale consisted of 4 factors.

• Design & Manufacturing
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• 제17권1호
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• pp.33-39
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• 2023

The ball end mill is a type of cutting tool that is widely used to process complex mold shapes including aspheric surfaces. Unlike the flat end mill in which the cutting edge is formed on the cylindrical handle, the cutting edge is formed from the cylindrical handle to the hemispherical shape, which is advantageous for processing curved shapes. However, since the cutting speed continuously changes during machining due to the helix angle of the cutting edge or the machining inclination angle, it is difficult to obtain a precise machined surface. Therefore, in this paper, machining was performed while changing the helix angle of the ball end mill and the angle of the machining slope under the same cutting conditions for STD 11 material, which is widely used as a mold material. Through this, the effect of the two variables on the roughness of the machined surface was analyzed. As a result, if the helix angle was 0 degrees, it showed the best surface roughness of Ra. 0.16 ㎛. When the helix angle was 20 degrees, the best surface roughness of Ra. 0.18 ㎛ was occurred.

• 유통과학연구
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• 제20권3호
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• pp.13-22
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• 2022

Purpose: Thisstudy aims to measure the attitudes of Generation Z in Jakarta towards advertisements containingCOVID-19 information. Research design, data and methodology: This study is a quantitative method with partial least square structural equation modeling (PLS-SEM) with SMART PLS as an analytical tool. The sample size is 216 participants was obtained randomly through a questionnaire distributed online. This study consisted of exogenous variables (advertising content, value, irritation, and economic benefits), endogenous variables (attitudes towards advertising), and some moderating roles. Results: The results of thi study explain that this generation's attitude towards advertising is affected by the content and value aspects embedded in advertisements. Value can be formed from creativity in making advertising content as interesting and informative as possible. Interestingly, this study also found that the irritation aspect and economic benefits had no effect on the audience's attitude towards the advertisement. Neither the irritating aspect of advertising nor the economic value that is formed acts as a moderator of the content and the value of the ad. Conclusions: The ongoing pandemic and periodic adjustments to government policies regarding COVID-19, these results can be compared with other advertisements for future studies, especially those using the same variables as this study.

• 한국산학기술학회논문지
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• 제20권12호
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• pp.513-518
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• 2019

마찰교반용접(Friction Stir Welding) 기술은 금속 소재를 대상으로 하는 용접기술 중의 하나로 용접대상이 되는 소재와 고속으로 회전하는 용접툴 사이의 마찰로 인한 열을 활용하여 소재의 융점 이하 온도에서 접합하는 기술이다. 이번 연구에서는 마찰교반용접을 진행할 때, 용접 대상물의 내부 온도 변화를 분석하기 위한 방법으로 수치해석기법을 사용하였다. 용접소재로는 마그네슘 합금인 AZ31을 고려하였으며, 용접현상을 멜팅풀(melting-pool)이 생성되는 유동특성으로 간주하고 유동해석을 수행하기 위해 유동특성 수치해석 툴인 FLUENT를 이용하였다. 용접과정의 유동해석을 진행하기 위해 용접소재는 고점도 뉴턴 유체로 가정하였고, 용접툴과 용접대상 소재의 경계면은 마찰 및 미끄러짐이 동시에 발생하는 조건으로 경계조건을 선정하였다. 그리고 용접툴의 회전속도 및 용접속도를 변수로 하여 다양한 해석을 진행하였다. 해석 결과로부터 용접툴의 회전속도가 높을수록, 용접속도가 느릴수록 소재 내 최고온도가 증가함을 확인할 수 있었으며, 그 중 용접툴의 회전속도 차이가 온도 변화에 더 큰 영향을 보임을 확인하였다.

• Journal of Welding and Joining
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• 제34권3호
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• pp.17-22
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• 2016

In terms of mechanical and metallurgical characteristics, the effect of tool plunge depths(0.2, 0.5, 0.7, 1.0, 1.5mm) on weldability in dissimilar Al5083-O/DP590 friction spot joint has been clarified. From the results, it is found that the stirred nugget was stably formed at a plunge depth of more than 0.7mm, which is caused by improved stirring action against each other material. With increasing a plunge depth, the thickness of intermetallic compound(IMC) layer in Al5083-O/DP590 joint has a tendency to increase. The tensile shear strength reaches to the maximum failure load of 6.5kN at a plunge depth of 0.7mm due to relatively small decrease in the thickness of Al5083-O sheet and relatively minute thickness of IMC layer, compared with those of other plunge depth conditions.