• Journal of Magnetics
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• 제18권1호
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• pp.30-33
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• 2013

The magnetocaloric effect and magnetization behavior have been analyzed in the double-perovskite $La_{0.7}Ba_{0.3}Mn_{1-X}Fe_XO_3$ compound with the sintering temperature at 1273 K. Samples were fabricated by the conventional solid-state reaction method. X-ray diffraction measurement revealed that all the samples had a single phase in orthorhombic. Detailed investigations of the magnetic entropy behavior of the samples were discussed with the variation of $T_C$. The magnetic entropy changes, ${\Delta}S_M$ of approximately 0.36-1.14 J/kg K were obtained in the temperature range of 145-350 K for the $La_{0.7}Ba_{0.3}Mn_{1-X}Fe_XO_3$ compound. The enhancement of the magnetic entropy change is believed to be due to changes in the microstructure, which changes the magnetic part of the entropy of a solid around the magnetic ordering temperature.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1993년도 추계학술대회 논문집
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• pp.6-9
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• 1993

본 연구에서는 소량(lmol%)의 MnO$_2$를 첨가한 Ba(Zn$_{1}$3Ta$_{2}$3)O$_3$에서 미량(x)외 Ba를 결핍 시켜가면서 마이크로파 유전 특성과 소결성, 구조적 특성을 관찰하였다. XRD분석을 통하여 Ba의 부족량이 증가함에 따라 Ba(Zn$_{1}$3/Ta$_{2}$3/)O$_3$B site의 규칙화와 격자 비틀림(Lattice Distortion)이 촉진되었다. 무부하 Q값은 10.5GHz에서 x가 0.01일때 가장 높은 간(8500)을 나타내었으나 이 후에는 급격히 감소하였고 온도 계수는 Ba의 부족량이 중가함에 따라 중가하였고, x가 0.01일때는 약 2ppm/$^{\circ}C$였다.

• 대한화학회지
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• 제40권9호
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• pp.607-614
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• 1996

$ABO_3$계 perovskite 구조에서 A자리의 $Pb^{2+}$ 이온이 $Na^+La^{3+}$혼합 이온 으로 0-50mol.%치환된 $Pb_{1-x}(Na_12/La_12)_x(Mg_13/Nb_23/)O_3$ 화합물의 구조변화와 유전 성질을 X-선 회절법, 작외선과 라만 분광법, LCR meter등으로 연구하였다. $Na^+La^{3+}$혼합 이온의 치환량과 소결 온도가 증가함에 따라 perovskite 상의 양이 증가하였다. 치환량이 증가할 때 1:1 질서화에 의한 초격자선을 X-선 회절법으로 발견할수 없었지만, 라만 분광법과 이완성 매개변수의 증가로부터 A자리 양이온의 크기감소가 질서화에 영향을 미침을 알 수 있었다. Pb_{1-x}(Na_12/La_12)_x(Mg_13/Nb_23/)O_3$의 유전 성질은 perovskite 상의 양과 낟알 크기 및 밀도에 의해 영향을 받았고, 치환량이 증가할 때 상전이는 확산되었으며 상전이 온도는 감소하였다.

• 한국프랜차이즈경영연구
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• 제12권1호
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• pp.7-19
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• 2021

Purpose: According to the growth of technology in the service industry, the interaction service between customer and employee has recently been transformed into between customer and technology by Self Service Technology (SST) requiring direct interaction with customers. In this context, self service technology such as unmanned ordering system installed at the store is actively introduced at the work place to reduce labor costs by food and retail company and the research for self-service technology which is rapidly replacing existing face-to-face service is needed. As the growth speed of SST is rapid, many researchers have studied the characteristics of SST, in every sector of business worldwide. Among the characteristics, attributes, Self Service Technology Quality (SSTQUAL) to evaluate SST is important because it may cause the customer's behavior. Thus, this research focuses on the effects of SSTQUAL on SST Satisfaction and SST continuance usage intention. This research suggests the guidelines for how Restaurant Company should prepare SST and build their customer satisfaction and continuance usage that increase the sales. Research design, data and methodology: This study tests the structural relationship between SSTQUAL of unmanned ordering system, SST satisfaction and SST continuance usage. SSTQUAL divided into four sub-dimensions and two categories, cognitive service attributes (Convenience, Functionality) and affective service attributes (Enjoyment, Assurance). In order to achieve the purposes of this research, research model and hypotheses were developed based on previous researches. All constructs were measured with multiple items developed and tested in the previous studies. The data were collected from 524 customers experiencing SST and were analyzed through SPSS 25.0 and SmartPLS 3.0 statistical package program. Results: The findings of this research are as follows. First, all SSTQUAL have significant positive impacts on SST satisfaction. Second, SST satisfaction has significant positive impact on SST continuance intention. Third, cognitive service attributes and affective service attributes had wealth of explanation of service attribute more than a single dimension. Conclusions: The implications of this study are as follows. Overall, Restaurant Company should manage SSTQUAL consisting of not only cognitive service attributes (Convenience, Functionality) but also affective service attributes (Enjoyment, Assurance) to satisfy customers basically regardless of the type of restaurant.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1262-1266
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• 2010

In this study, we investigated the use of liquid crystals to selectively detect the activity of enzymes at interfaces decorated with oligopeptide-based membranes. We prepared a mixed monolayer of tetra(ethylene glycol)-terminated lipids and carboxylic acid-terminated lipids at the aqueous-liquid crystal (LC) interface. The 17 amino-acid oligopeptide SNFKTIYDEANQFATYK was then immobilized onto this mixed monolayer through N-hydroxysuccinimide-activation of the carboxylic acid groups. We examined the orientational behavior of nematic 4-cyano-4'-pentylbiphenyl (5CB) after conjugation of the 17 amino-acid oligopeptide with the mixed monolayer assembled at the interface. Immobilization of the oligopeptide caused orientational transitions in 5CB, with a change from homeotropic (perpendicular) to tilted alignment, which was primarily due to the reorganization of the monolayer. The orientation of the 5CB molecules returned to its homeotropic state after contacting the interface containing ${\alpha}$-chymotrypsin, which can cleave the immobilized oligopeptide. Control experiments confirmed that the enzymatic activity of ${\alpha}$-chymotrypsin triggered the ordering transitions in the LC. These results suggest that the LC can provide a facile method for selective detection of enzymatic activity.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2013년도 임시총회 및 하계학술연구발표회
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• pp.15-16
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• 2013

Magnetization behavior of ultra thin $Fe_xCo_{1-x}$ alloy (where x varies from 0 to 100) has been investigated as functions of composition on Cr (100) substrate by using in situ surface magneto optical Kerr effect (SMOKE). It's always show in plane uniaxial magnetic anisotropy at room temperature (RT) & Low temperature (LT). It is observed that composition dependent coercive force maximum at about 30 at % Co and 70 at % Co atomic ratio and minimum near equiatomic site. The relative magnetic moments as composition variation also show magnetization collapse near equiatomic site. The magnetization behaviors of Fe-Co alloy on Cr (100) due to composition varies are supported the order-disordering as well as structural stability bcc (ferromagnetic)/fcc (anti-ferromagnetic) phase stability magnetism.

• Structural Engineering and Mechanics
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• 제14권6호
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• pp.661-677
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• 2002

The subject of this investigation is to study the buckling of cross-ply laminated orthotropic cylindrical thin shells with variable elasticity moduli and densities in the thickness direction, under external pressure, which is a power function of time. The dynamic stability and compatibility equations are obtained first. These equations are subsequently reduced to a system of time dependent differential equations with variable coefficients by using Galerkin's method. Finally, the critical dynamic and static loads, the corresponding wave numbers, the dynamic factors, critical time and critical impulse are found analytically by applying a modified form of the Ritz type variational method. The dynamic behavior of cross-ply laminated cylindrical shells is investigated with: a) lamina that present variations in the elasticity moduli and densities, b) different numbers and ordering of layers, and c) external pressures which vary with different powers of time. It is concluded that all these factors contribute to appreciable effects on the critical parameters of the problem in question.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2007년도 추계학술대회 및 정기총회
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• pp.104-107
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• 2007

In this paper, we propose the coordination scheme in a single-manufacturer-multiple-retailer supply chain system. Traditionally, the bargaining power of the single manufacturer is superior to those of retailers. The business environment supported by the e-business scheme may give rise to new business behavior. The multitude of retailer requests the manufacturer to relax the his unilateral lot-sizing policy while they are willing to compensate more than the manufacturer's expected loss caused by abandon his superior bargaining power. The side payment aggregated by the multiple retailers is transferred to the manufacturer according to the degree of the manufacturer's relaxation from the current unilateral lot-sizing policy.

• 기술사
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• 제42권5호
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• pp.29-31
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• 2009

A general practice in software ordering behavior in public sector has been an enormous obstacle standing in development path of Korea's software industry. Standard on software development cost estimation is supposedly based on Function Point, but in general, it is on headcounting (a number of people involved in a project). Moreover, it is difficult to change a contract in an on-going project, since statement of work is not precisely and carefully described. But it has a simple solution. Design and Implementation should be a separate project, as in construction industry, and both power and responsibility for design should be given to an expert with a national-level qualification. Here, there is a simple way for Korea to reborn as one of the strongest software country.

• International Journal of Concrete Structures and Materials
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• 제9권4호
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• pp.453-462
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• 2015

A critical review on existing creep theories in calcium-silicate-hydrate (C-S-H) is presented with an emphasis on several fundamental questions (e.g. the roles of water, relative humidity, temperature, atomic ordering of C-S-H). A consensus on the rearrangement of nanostructures of C-S-H as a main consequence of creep, has almost been achieved. However, main disagreement still exists on two basic aspects regarding creep mechanisms: (1) at which site the creep occurs, like at interlayer, intergranular, or regions where C-S-H has a relatively higher solubility; (2) how the structural rearrangement evolutes, like in a manner of interlayer sliding, intra-transfer of water at various scales, recrystallization of gelled-like particles, or dissolution-diffusion-reprecipitation at inter-particle boundary. The further understanding of creep behavior of C-S-H relies heavily on the appropriate characterization of its nanostructure.