The Prediction of the Mechanical properties of Magnesium Alloys using DFT Method (초)

백민숙,염동선,김기빈,정현철,김양수,김병일 대한금속재료학회 ( 구 대한금속학회 ) 2007 대한금속재료학회 학술대회 개요집 Vol.2007 No.1

바리스타의 직무속성이 러브마크 속성 및 브랜드충성도에 미치는 영향

백민숙 한국커피협회 2016 한국커피문화연구 Vol.2 No.1

This research is based on service marketing to explain the effect of barista job attributes as the antecedents of lovemarks for increasing brand loyalty. The analysis was held with customers who experienced local and national coffee shop in Pusan area by using SPSS18K and Smart PLS 2.0. The study verified the structural equation model hypothesizing the relationship among related factors including barista job attributes, lovemarks and brand loyalty. According to the result of this study, barista job attributes factors including expertise, communication, and service orientation have positive effect on the lovemark. Furthermore, structural relationships among lovemark variables were identified through hypothesis testing. However, the effects of expertise and service orientation on intimacy were not significant especially in local brand. Additional multi-group testing was conducted to explain managerial implication of this research. The research has several marketing implication on service marketing and lovemark theory. For firms, customers’perception of barista’s job attributes can generate positive lovemark effect and develop brand loyalty in the service marketing perspectives. 본 연구는 커피전문점에 종사하는 바리스타의 직무속성이 고객들이 바리스타에 대해 느끼게 되는 러브마크속성에 어떠한 영향 을 미치는지, 그리고 이러한 러브마크가 궁극적으로 브랜드 충성도에 영향을 미칠 수 있는지를 검증하고자 한다. 로컬 브랜드는 전문 성, 상호작용성을 통한 고객과의 친밀감 형성, 이를 통한 러브마크와 브랜드충성도 구축을 통한 긍정적 성과창출을 바리스타와 고객 간의 러브마크형성에 가장 큰 영향을 미치는 것은 양 당사자 간의 상호작용의 질이라고 할 수 있으며 로컬 커피전문점의 경우 내셔널 커피전문점에 비해 고객과의 바리스타간의 친밀한 관계가 더 잘 형성되고 있음을 확인할 수 있고 내셔널 커피전문점이라 하더라도 고 객과의 상호작용에 더 관심을 기울이고러브마크 형성에 역량을 집중하면 더 긍정적인 성과를 얻을 수 있도록, 내셔널 브랜드는 다소 부족한 전문성 및 상호작용성의 보완을 통해서 고객들과의 관계를 더욱 더 공고히 하여 추가적인 수익과 성장을 기대할 수 있을 것이 다

의복구매 행동에 관한 연구

백민숙 충남대학교 이과대학 가정교육과 1988 家政學硏究 Vol.- No.4

DV-Xα 분자궤도법으로 설계한 생체용 Ti-Ag-Zr 합금 특성 평가

백민숙,윤동주,김병일,Baek, Min-Sook,Yoon, Dong-Joo,Kim, Byung-Il 한국재료학회 2014 한국재료학회지 Vol.24 No.4

Ti and Ti alloys have been extensively used in the medical and dental fields because of their good corrosion resistance, high strength to density ratio and especially, their low elastic modulus compared to other metallic materials. Recent trends in biomaterials research have focused on development of metallic alloys with elastic modulus similar to natural bone, however, many candidate materials also contain toxic elements that would be biologically harmful. In this study, new Ti based alloys which do not contain the toxic metallic components were developed using a theoretical method (DV-$X{\alpha}$). In addition, alloys were developed with improved mechanical properties and corrosion resistance. Ternary Ti-Ag-Zr alloys consisting of biocompatible alloying elements were produced to investigate the alloying effect on microstructure, corrosion resistance, mechanical properties and biocompatibility. The effects of various contents of Zr on the mechanical properties and biocompatibility were compared. The alloys exhibited higher strength and corrosion resistance than pure Ti, had antibacterial properties, and were not observed to be cytotoxic. Of the designed alloys' mechanical properties and biocompatibility, the Ti-3Ag-0.5Zr alloy had the best results.

밀도함수 이론법을 이용한 마그네슘 합금의 재료특성 예측에 관한 연구

백민숙,원대희,김병일,Baek, Min-Sook,Won, Dae-Hee,Kim, Byung-Il 한국재료학회 2007 한국재료학회지 Vol.17 No.12

The total energy and strength of Mg alloy doped with Al, Ca and Zn, were calculated using the density functional theory. The calculations was performed by two programs; the discrete variational $X{\alpha}\;(DV-X{\alpha})$ method, which is a sort of molecular orbital full potential method; Vienna Ab-initio Simulation Package (VASP), which is a sort of pseudo potential method. The fundamental mixed orbital structure in each energy level near the Fermi level was investigated with simple model using $DV-X{\alpha}$. The optimized crystal structures calculated by VASP were compared to the measured structure. The density of state and the energy levels of dopant elements was discussed in association with properties. When the lattice parameter obtained from this study was compared, it was slightly different from the theoretical value but it was similar to Mk, and we obtained the reliability of data. A parameter Mk obtained by the $DV-X{\alpha}$ method was proportional to electronegativity and inversely proportional to ionic radii. We can predict the mechanical properties because $\Delta{\overline{Mk}}$is proportional to hardness.

Al 2013-T8 합금에서 Zr 첨가에 따른 기계적 특성 분석

백민숙,조사현,박만복,윤동주,허기복,Baek, Min-Sook,Cho, Sa-Hyeon,Park, Man-Bok,Yoon, Dong-Joo,Heo, Ki-Bok 한국재료학회 2016 한국재료학회지 Vol.26 No.8

In this study, the recently developed Al 2013 alloy was T8-tempered and, to improve the strength and corrosion-resistance, slight amounts of Zr of 0.2 wt% and 0.5 wt%, respectively, were added and the mechanical properties were analyzed. For microstructure and precipitate analysis, OM observation, XRD analysis, and TEM analysis were performed, and for the mechanical property analysis, hardness and tensile strength tests were done. Also, in order to determine the corrosion rate according to the Zr content, a potentiodynamic polarization test was performed and the properties were compared and analyzed. The size of the precipitate varied with the content of Zr and was finest at Zr content of 0.2 wt%; it grew larger at 0.5 wt%, at which point the hardness value accordingly showed the same trend. On the other hand, as calculated from the aspect of chemical bonding among atoms, it was confirmed that the tensile strength and the corrosion-resistance increased with the same trend.

AIP법으로 형성된 TiAgN 코팅필름의 바이어스전압에 따른 표면 특성 분석

백민숙,윤동주,강병모,정운조,김병일,Baek, Min-Sook,Yoon, Dong-Joo,Kang, Byeong-Mo,Jeong, Woon-Jo,Kim, Byung-Il 한국재료학회 2015 한국재료학회지 Vol.25 No.5

The implanting of metal products is performed with numerous surface treatments because of toxicity and adhesion. Recently, the surface modification of metal products has been actively studied by coating the surface of the TiC or TiN film. We prepared a Ti(10%)Ag Target which may be used in dental oral material by, using the AIP(arc ion plating) system TiAgN coating layer that was deposited on Ti g.23. The purpose of this study was to establish the optimal bias voltage conditions of the coated TiAgN layer formed by the AIP process. The TiAgN coatings were prepared with different bias voltage parameters (0V to -500V) to investigate the effect of bias voltage on their mechanical and chemical properties. The SEM(scanning electron microscope), EDS(energy dispersive X-ray spectrometer), XRD(X-ray diffraction), micro-hardness, and potentiodynamic polarization were measured and the surface characteristics of the TiAgN coating layers were evaluated. The TiAgN coating layer had different mechanical characteristics based on the bias voltage, which also showed differences in thickness and composition.

에너지 전자상태 계산으로 도출된 이론값을 이용한 니켈 합금 설계

백민숙,강법성,백경철,김병일,윤동주,Baek, Min-Sook,Kang, Pub-Sung,Baek, Kyeong-Cheol,Kim, Byung-Il,Yoon, Dong-Joo 한국재료학회 2015 한국재료학회지 Vol.25 No.11

Super alloys, which can be divided into three categories, i.e. Ni-base, Co-base, and Fe-base alloys, are widely used for high temperature applications. Since superalloys contain many alloying elements and precipitates, their chemistry and processing parameters need to be carefully designed. In this study, we designed a new Ni alloy to prevent corrosion due to water vapor and gases at high temperatures. The new alloy was designed using the theoretical value of the resulting energy electronic state calculation($DV-X{\alpha}$ method). The components that were finally used were Cr, Mo, and Ti, with Ni as a base. For these alloys, elements were selected in order to compare their values with that of the average theoretical basis for an Inconel 625 alloy. Finally, two kinds of Ni alloy were designed: Ni-28Cr-4Mo-2Ti and Ni-20Cr-10Mo-1Ti.

AIP법으로 증착된 TiN/CrN 다층박막의 특성 분석

백민숙,윤동주,허기복,김병일,Baek, Min-Sook,Yoon, Dong-Joo,Heo, Ki-Bok,Kim, Byung-Il 한국재료학회 2018 한국재료학회지 Vol.28 No.7

TiN and CrN thin films are among the most used coatings in machine and tool steels. TiN and CrN are deposited by arc ion plating(AIP) method. The AIP method inhibits the reaction by depositing a hard, protective coating on the material surface. In this study, the characteristics of multi-layer(TiN/CrN/TiN(TCT), CrN/TiN/CrN(CTC)) are investigated. For comparison, TiN with the same thickness as the multilayer is formed as a single layer and analyzed. Thin films formed as multilayers are well stacked. The characteristics of micro hardness and corrosion resistance are better than those of single layer TiN. The TiN/CrN peak is confirmed because both TCT and CTC are formed of the same component(TiN, CrN), and the phase is first grown in the (111) direction, which is the growth direction. However, the adhesion and abrasion resistance of the multilayer films are somewhat lower.

연속용융 도금라인 용 고내침식 Fe계 합금 개발

백민숙(Min-Sook Baek),김용철(Yong-Cheol Kim),백경철(Kyeong-Cheol Baek),곽준섭(Joon-Seop Kwak),윤동주(Dong-Joo Yoon) 한국표면공학회 2020 한국표면공학회지 Vol.53 No.3

In this study, the material used in the hot dip galvanizing equipment was poorly corrosion-resistant, so it was performed to solve the cost and time problems caused by equipment replacement. The theoretical calculation was performed using the DV-Xα method(Discrete Variational Local-density approximation method). The alloy (STS4XX series) of the equipment currently used has a martensite phase. Therefore, the theoretical calculation was performed by applying P4 / mmm, which is a tetragonal structure. The new alloy was chosen by designing theoretical values close to existing materials. Considering elements that contribute to corrosion, most have high prices. Therefore, the design was completed by adjusting the content using only the components of the reference material in the theoretical design. The final design alloys were chosen as D6 and D9. Designed D6 and D9 were dissolved and prepared using an induction furnace. After the heat treatment process was completed, the corrosion rate of the alloys was confirmed by using the potentiodynamic polarization test. The surface of the prepared alloys were processed horizontally and then polished to # 1200 using sand paper to perform potentiodynamic polarization test. Domestic products: 4.735 mpy (mils / year), D6: 0.9166 mpy, D9: 0.3372 mpy, alloys designed than domestic products had a lower corrosion rate. Therefore, the designed alloy was expected to have better erosion resistance.