• Steel and Composite Structures
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• 제31권4호
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• pp.419-426
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• 2019

In this paper, buckling analyses of composite plate reinforced by Graphen platelate (GPL) is studied. The Halphin-Tsai model is used for obtaining the effective material properties of nano composite plate. The nano composite plate is modeled by Third order shear deformation theory (TSDT). The elastic medium is simulated by Winkler model. Employing nonlinear strains-displacements, stress-strain, the energy equations of plate are obtained and using Hamilton's principal, the governing equations are derived. The governing equations are solved based on Navier method. The effect of GPL volume percent, geometrical parameters of plate and elastic foundation on the buckling load are investigated. Results showed that with increasing GPLs volume percent, the buckling load increases.

• 미술이론과 현장
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• 제2호
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• pp.147-168
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• 2004

This study examined the role of interpretation with various practices in art museums to seek a new meaning and a concept of art museum today. The exploration of interpretation would he a starting point to discuss about on art museums with professionals in each art-related field. While museums recognize the concept of interpretation and the scope of the functions in different levels, the study focused on the practices of collecting and exhibiting that will entrust the museum new realms of activities toward the audience. In particular, its emphases are set force on the information on the collections via the museum's web sites, interpretation policies, and theories and methodologies in exhibition development. Art museum websites well reflect how museums utilize the new medium to enhance the understanding of art works by providing in-depth art historical information, comprehensive contexts, and subject/concept based search methods. In recent decades, these have enacted changes to expand dimensions of interpretive functions in most museums, particularly in the United States and others. In an administrative perspective, Tate Gallery Interpretation Policy became an good example how an art museum put its interpretation philosophy as the basis of interpreting collection and public programs. Tate established functions of intrepretation and education not only within a task-based team but also as an intrer-divisional coorperation to provide an interpretation scheme of information provisions such as guide brochure, audio tour, multimedia content, and library. New environment and trends of museum exhibition, and its development processes stem from communication theories, object interpretation philosophy, display strategies, and various evaluation techniques through audiences, with the communication theories of Shannon and Weaver, Berlo's SMCR(Source-Message-Channel-Receiver) models were perceived as to understand the mechanism to communicate museum exhibits to visitors Suzan vogel's insight into object display strategy helped to conceive the mechanism of object recontextualization. She emphasized that the museum's practice to construe opinions and impressions through object display should be discreet and critical, therefore, the professionals to plan the exhibition should reveal the intention and their practices. For a prevailing new methodology from the field, the interpretive exhibition development processes are articulated as the front-end, formative, and summative evaluation, futhermore the team process in industrial product management models was adapted. These have turned out to be more interactive with visitors and effective to communicate the exhibition concepts and messages, hence resulting in enriched museum experiences. Finally the study concluded that understanding the aspects of interpretation should help art museums to set a framework for current practices to expand its public dimension. It can provide curators with a critical view to website planning and its content. And obviously, the interpretive exhibition development methodology will lead museum exhibition developers to be skilled in its current approaches to thematic exhibition concerning diverse subjects and topics.

• Steel and Composite Structures
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• 제20권3호
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• pp.623-649
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• 2016

Most of the early studies on plates vibration are focused on two-dimensional theories, these theories reduce the dimensions of problems from three to two by introducing some assumptions in mathematical modeling leading to simpler expressions and derivation of solutions. However, these simplifications inherently bring errors and therefore may lead to unreliable results for relatively thick plates. The main objective of this research paper is to present 3-D elasticity solution for free vibration analysis of continuously graded carbon nanotube-reinforced (CGCNTR) rectangular plates resting on two-parameter elastic foundations. The volume fractions of oriented, straight single-walled carbon nanotubes (SWCNTs) are assumed to be graded in the thickness direction. In this study, an equivalent continuum model based on the Eshelby-Mori-Tanaka approach is employed to estimate the effective constitutive law of the elastic isotropic medium (matrix) with oriented, straight carbon nanotubes (CNTs). The proposed rectangular plates have two opposite edges simply supported, while all possible combinations of free, simply supported and clamped boundary conditions are applied to the other two edges. The formulations are based on the three-dimensional elasticity theory. A semi-analytical approach composed of differential quadrature method (DQM) and series solution is adopted to solve the equations of motion. The fast rate of convergence of the method is demonstrated and comparison studies are carried out to establish its very high accuracy and versatility. The 2-D differential quadrature method as an efficient and accurate numerical tool is used to discretize the governing equations and to implement the boundary conditions. The convergence of the method is demonstrated and to validate the results, comparisons are made between the present results and results reported by well-known references for special cases treated before, have confirmed accuracy and efficiency of the present approach. The novelty of the present work is to exploit Eshelby-Mori-Tanaka approach in order to reveal the impacts of the volume fractions of oriented CNTs, different CNTs distributions, various coefficients of foundation and different combinations of free, simply supported and clamped boundary conditions on the vibrational characteristics of CGCNTR rectangular plates. The new results can be used as benchmark solutions for future researches.

• Asia pacific journal of information systems
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• 제4권2호
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• pp.214-246
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• 1994

As the use of information technology continues to bring a dramatic increase in the amount of data available to managers, researchers have noted that having too much data can be as much of a problem as having too little. It becomes very important to understand the effects of "information explosion" on the way managers perform their work. This study examines the effect of the amount of available data on the process and outcome of thinking within a context where managers are equipped with computing tools. The purpose of this study is to better understand how managers respond cognitively to increased information availability. In this experiment with 104 MBAs three groups of subjects were asked to identify high and low potential market categories for effective direct mail sales based on three different amount of computer-based socioeconomic data designed based on existing research on cognition and information overload. Analyses of the outcomes showed that the group with medium amount of data used data and computer-based analysis tools most effectively and efficiently. We expect that the study will provide us a base to relate future MIS research to theories on cognition in such related fields as psychology and organizational behavior.

• 한국IT서비스학회지
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• 제16권2호
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• pp.1-20
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• 2017

A bitcoin-based technology named blockchain is garnering attention in various industries as a cost-effective measure in strengthening security and a reliable technology medium. Blockchain technology will play a critical role in the Fourth Industrial Revolution, and IT technology is expected to bring fundamental changes. This study focuses on the characteristics of blockchain technology and the effects of the intention to accept its technology in an empirical manner. The aspects of the technology are organized by researching blockchain technology and theories of technology acceptability and previous studies were used as guidelines to create the research model and propose the hypothesis. The research model is based on UTAUT with a set-up of 5 factors for performance expectancy and effort expectancy. For empirical analysis, a survey was conducted on 283 IT workers in Korea, To examine the hypothesis structural equation modeling was used performance expectancy was influenced by security, reliability, diversity, and economic efficiency while effort expectancy was influenced by reliability and economic efficiency. Performance expectancy, social influence, facilitating conditions affect the intention to accept. Innovativeness of an organization and control effects are influenced as well. The present study aims to provide practical guidance as supplementary research in utilizing blockchain technology, and the limitations of the study and future research possibilities are discussed as well.

• Steel and Composite Structures
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• 제24권6호
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• pp.711-726
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• 2017

In the present work, by considering the agglomeration effect of single-walled carbon nanotubes, free vibration characteristics of functionally graded (FG) nanocomposite sandwich plates resting on Pasternak foundation are presented. The volume fractions of randomly oriented agglomerated single-walled carbon nanotubes (SWCNTs) are assumed to be graded in the thickness direction. To determine the effect of CNT agglomeration on the elastic properties of CNT-reinforced composites, a two-parameter micromechanical model of agglomeration is employed. In this research work, an equivalent continuum model based on the Eshelby-Mori-Tanaka approach is employed to estimate the effective constitutive law of the elastic isotropic medium (matrix) with oriented straight CNTs. The 2-D generalized differential quadrature method (GDQM) as an efficient and accurate numerical tool is used to discretize the equations of motion and to implement the various boundary conditions. The proposed rectangular plates have two opposite edges simply supported, while all possible combinations of free, simply supported and clamped boundary conditions are applied to the other two edges. The benefit of using the considered power-law distribution is to illustrate and present useful results arising from symmetric and asymmetric profiles. The effects of two-parameter elastic foundation modulus, geometrical and material parameters together with the boundary conditions on the frequency parameters of the laminated FG nanocomposite plates are investigated. It is shown that the natural frequencies of structure are seriously affected by the influence of CNTs agglomeration. This study serves as a benchmark for assessing the validity of numerical methods or two-dimensional theories used to analysis of laminated plates.

• Structural Engineering and Mechanics
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• 제73권5호
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• pp.555-563
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• 2020

The objective of present paper is assessment of dynamic buckling behavior of an embedded sandwich microplates in thermal environment in which the layers are reinforced through functionally graded carbon nanotubes (FG-CNTs). Therefore, mixture rule is taken into consideration for obtaining effective material characteristics. In order to model this structure much more realistic, Kelvin-Voigt model is presumed and the sandwich structure is rested on visco-Pasternak medium. Exponential shear deformation theory (ESDT) in addition to Eringen's nonlocal theory are utilized to obtain motion equations. Further, differential cubature method (DCM) as well as Bolotin's procedure are used to solve governing equations and achieve dynamic instability region (DIR) related to sandwich structure. Different parameters focusing on volume percent of CNTs, dispersion kinds of CNTs, thermal environment, small scale effect and structural damping and their influences upon the dynamic behavior of sandwich structure are investigated. So as to indicate the accuracy of applied theories as well as methods, the results are collated with another paper. According to results, presence of CNTs and their dispersion kind can alter system's dynamic response as well.

• 한국광학회지
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• 제1권1호
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• pp.73-86
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• 1990

The technique of Spectroscopic Ellipsometry (SE) has been examined with emphasis on its inherent sensitivity to the existence of thin films or surface equivalents. A brief review of related theories like the Fresnel reflection coefficients, the effect of a multilayer upon reflectivities, together with the validity of the effective medium theory and the modelling procedure, is followed by a short description of the experimental setup of a rotating polarizer type SE as well as the necessful expressions which lead to tan and cos. Out of its numerous, successful applications, a few are exampled to convince a reader that SE can be applied to a variety of research fields related to surface, interface and thin films. Specifically, those are adsorption and/or desorption on metals or semiconductors, oxidation process, formation of passivation layers on an electrode, thickness determination, interface between semiconductor and its oxide, semiconductor heterojunctions, surface microroughness, void distribution of dielectric, optical thin films, depth profile of multilayered samples, in-situ or in-vitro characterization of a solid surface immersed in electrolyte during electrochemical, chemical, or biological treatments, and so on. It is expected that the potential capability of SE will be widely utilized in a very near future, taking advantage of its sensitivity to thin films or surface equivalents, and its nondestructive, nonperturbing characteristics.

• 한국실내디자인학회논문집
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• 제24권6호
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• pp.229-239
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• 2015

The 21st century is a multiplication age and social and cultural phenomena have become diverse and peoples' desires and individuality have become important. Accordingly, the sensibility that reflects human taste is also required in the exhibition space. The exhibitions in this age induce the direct cognition of senses or take interactive forms that contact diverse media and react. The purpose of this research is to define the concept of haptic presentation method in which the audience perceive in the exhibition space by themselves and the visual elements spread into other senses and perceive complexly, and to present the directional nature. To conduct this research, first, this researcher recognized that haptic sensory experiential research by analyzing the roles and transition history of exhibition space is needed for the present age Second, based on philosophical theories, four haptic sensory expression characteristics (medium nature, experiential nature, attractiveness, sensitiveness) were derived by substituting Giles Deleuze's four haptic spatial characteristics (grasping short distance, dispersed gaze, cognition of bodily movement, formation of synesthesia through complex senses) and six formative factors of exhibition space (space, form, size, light, quality of materials, and color). And the effective exhibition presentation methods were analyzed through six cases of experiential exhibition spaces. Accordingly, what matters in the experiential exhibition space is to produce the four characteristics: medium nature, experientiality, attractiveness, and sensitiveness in equilibrium. It is necessary for the designers to reflect it appropriately in producing so that the audience can think and experience by themselves. Accordingly, in this thesis, it could be seen that to produce the haptic production characteristics in the experiential exhibition space in equilibrium is the important factor in the experiential exhibition space. In conclusion, experiences in the exhibition space should be approached with the transcendental haptic presentation method by which even the space of actually unexperienced cognition can be expanded and experienced through the metastasis and tension of various senses. Also, researches on such senses should be developed continuously, and this researcher expects that this will become a stimulant to present a new directivity.

• 디지털융복합연구
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• 제10권11호
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• pp.81-86
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• 2012

세계적인 경제 불황 환경에서 클라우드 컴퓨팅은 IT 분야에서 새로운 패러다임이 되었다. 본 논문은 클라우드 서비스 중에서 SaaS(Software as a Service) 초점을 두기로 한다. 기술수용모형(TAM)은 사용자가 새로운 기술을 어떻게 받아들이는 지를 연구하는데 활발하게 적용되어 왔으나, SaaS 채택과 관련된 이슈는 아직 연구되지 않았다. 본 논문의 목적은 중소기업의 SaaS 채택의도에 영향을 미치는 중요한 요인을 조사하기 위한 탐색 모델을 개발하는 것이다. 제안하는 탐색 모델은 마케팅 노력 등과 같은 요인들은 물론 기술수용모델과 관련된 중요한 요인을 파악하기 위한 가설들을 검증한다. 이를 통하여 본 연구에서는 회사 사용자들의 SaaS 채택에 관한 사용의도를 파악하는데 도움을 줄 수 있을 뿐만 아니라 SaaS 제공자들이 서비스 개발과 마케팅 전략의 향상을 위한 보다 노력해야할 요인들을 파악하는 데에도 도움을 줄 수 있다.