• Structural Engineering and Mechanics
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• v.81 no.2
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• pp.179-194
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• 2022

The bending, buckling and free vibration responses of functionally graded material (FGM) beams are investigated semi-analytically by the scaled boundary finite element method (SBFEM) in this paper. In the concepts of the SBFEM, the dimension of computational domain can be reduced by one, therefore only the axial dimension of the beam is discretized using the higher order spectral element, which reduces the amount of calculation and greatly improves the calculation efficiency. The governing equation of FGM beams is derived in detail by the means of the principle of virtual work. Compared with the higher-order beam theory, fewer parameters and simpler control equations are used. And the governing equation is transformed into a first-order ordinary differential equation by introducing intermediate variables. Analytical solutions of the governing equation can be obtained by pade series expansion in the direction of thickness. Numerical example are compared with the numerical solutions provided by the previous researchers to verify the accuracy and applicability of the proposed method. The results show that the proposed formulations can quickly converge to the reference solutions by increasing the order of higher order spectral elements, and high accuracy can be achieved by using a small number of the elements. In addition, the influence of the structural sizes, material properties and boundary conditions on the mechanical behaviors of FG beams subjected to different load types is discussed.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.1
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• pp.1-7
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• 2016

Purpose: The aim of this study was to evaluate the effect of increased vertical dimension of occlusion on lower facial changes by facial type. Materials and methods: Lateral cephalograms from 261 patients were obtained and classified by sagittal (Class I, II, and III) and vertical (hypodivergent, normodivergent, and hyperdivergent) facial patterns. Retrusive displacement of soft tissue Pogonion and downward displacement of soft tissue Menton were measured in each group after 2 mm of vertical dimension of occlusion was increased at the lower central incisor using a virtual simulation program. The ratio of both displacements was calculated in all groups. The statistical analysis was done by 2-way ANOVA and Post hoc was done by Tukey test (5% level of significance). Results: Retrusive displacement of soft tissue Pogonion in Class III group was statistically different compared to Class I and II, and in vertical facial groups all 3 groups were significantly different (P<.05). Downward displacement of soft tissue Menton showed statistically significant difference between all sagittal groups and vertical groups (P<.05). The ratio of both displacements showed statistically significant difference in all sagittal groups and vertical groups (P<.05), and Class II hyperdivergent group had the highest value. Conclusion: Lower facial change was statically significant according to the facial type when vertical dimension of occlusion increased. Class II hyperdivergent facial type showed the highest ratio after increase in vertical dimension of occlusion.

• CRM연구
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• v.4 no.1
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• pp.35-54
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• 2011

Organizing and maintaining customer-based online communities are becoming increasingly important in current business environment. Companies can utilize the member generated contents in developing their products and services and they can establish close relationships with their customers. This paper investigates how customer-based online communities increase individual members' contributive behaviors. Drawing on the social psychology literature, this study adopts the concept of self-discrepancy rooted in self-identity and derive an index for self-discrepancy by using the differences between actual and virtual self-identities. Furthermore, this study examines the relationship between the self-discrepancy and the anonymity-related psychological factors (autonomy, recovery, and catharsis), which in turn influence quality and quantity of contribution. Analysis of 114 respondents showed that self-discrepancy between actual and virtual selves has two different sub-dimensions (personal self-discrepancy and social sel f-discrepancy) and each dimension has different effect on the quality and quantity of contribution through the mediation of autonomy and recovery. Notably, catharsis negatively influenced quality of contribution. Theoretical and practical implications are discussed based on the major findings.

• The Transactions of the Korea Information Processing Society
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• v.4 no.12
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• pp.3033-3044
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• 1997

This paper presents a system which recognizes dynamic hand gesture for virtual reality (VR). A dynamic hand gesture is a method of communication for human and computer who uses gestures, especially both hands and fingers. Since the human hands and fingers are not the same in physical dimension, the produced by two persons with their hands may not have the same numerical values where obtained through electronic sensors. To recognize meaningful gesture from continuous gestures which have no token of beginning and end, this system segments current motion states using the state automata. In this paper, we apply a fuzzy min-max neural network and feature analysis method using fuzzy logic for on-line pattern recognition.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.136-141
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• 2008

The rapid development of the information technology has passed over the implementation of the virtual reality. It is realizing information services that are form of the globalization, based on the Internet. In addition, the effort to apply IT to public administration for public services has been made. The remarkable development of computer hardware has overcome the limit of the information distribution and emerged for practical use in various fields such as public institution, underground facilities management, tourism industry development etc. However, the practical use of Virtual Reality with Three-Dimensional GIS on disaster management by Korea National Emergency Management Agency is very much low. Therefore, this studies focus on how to use 3-Dimensional GIS for the purpose of fire disaster prevention. The studies also discussed, through understanding of the limitations of 2-Dimensional GIS, the establishment of basis for fire prevention technology development and its utilization among those ubiquitous city paradigms, which have become so much issues these days.

• The Journal of Information Systems
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• v.14 no.2
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• pp.75-99
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• 2005

Today, many universities are confronted with the changing education paradigm such as e-learning, Distance Education, Virtual University, This IT-based teaming paradigm shift is certainly a new opportunity or a threat to our universities. To overcome this problem the universities should think e-Learning as strategic weapon, such as many firms created competitive weapons from the information systems at the 1980s. So, e-Learning system can be a SIS(Strategic Information System) which supports university's future education strategies. To build a e-Learning system, not only many H/W and S/W resources but also expert personnels are required. An organization such as local university who is week at financial status can't himself plan the system. The Local University Community e-Learning Centers that support the demand of e-learning for their community are recommended. In order to operate these centers efficiently, the strategic roles of the e-Learning center should first be defined. To define the strategic roles, We classified the strategic roles of the e-Learning center into four dimensions, (1) to improve management efficiency, (2) to enhance educational service, (3) to acquire competitive advantages, (4) to build new education infrastructure, and each dimension has 5 or 6 measurement items. As result, to enhance the educational service was considered as the most significant factor among the four dimensions of strategic roles, and the infrastructure building was the next. We also tried to find the difference for each factor by the characteristics of responsor. The data showed that there was litter difference between the groups in evaluating the significance of strategic roles of e-learning centers. Through the strategic roles definition and analysis of expected role ratings, we could have recommended the direction and operation policies of the e-Loaming centers.

• Journal of Korea Game Society
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• v.5 no.3
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• pp.3-10
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• 2005

We present the computer table tennis game using player's swing motion. We need to transform a real world coordinate into a virtual world coordinate in order to hit the virtual ball. We can not get a correct 3-dimension position of racket in environment that using one camera or simple image processing. Therefore we use Augmented Reality (AR) concept to develop the game. This paper shows the AR table tennis game using gesture and method to develop the 3D interaction game that only using one camera without any motion detection device or stereo cameras. Also, we use a scan line method to recognize gesture for speedy processing. The game is developed using ARtoolkit and DirectX that is popular tool of SDK for game development.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.10
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• pp.129-138
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• 2021

Several studies have revealed that information on borrower characteristics plays an important factor in approving their credit requests. Though the extent to which such characteritics are also applicable to the case of fintech lending remain uncertain. The aim of this study is, thus, to investigate the determinant factors that influence MSEs in obtaining credit through fintech lending. Here, we emphasize virtual trust in fintech lending encompasing the dimension of social network, economic attributes, and risk perception based on several indicators that are used as proxies. Primary data used in the study was gathered from an online survey to the respondents of MSEs in Java. The result of the study indicates that determinants of MSEs in obtaining credit from lender through fintech lending are statistically influenced by internet usage activities, borrowing history, loan utilization, annuity payment system, completeness of credit requirement documents and compatibility of loan size with the business need. These factors have a significant effect on credit approval because they can generate virtual trust of fintech lender to MSEs as potential borrowers. It concludes that the probability of obtaining fintech loans in accordance with their expectations are influenced by the dimensions of social network, economic attributes and risk perception.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.9
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• pp.1104-1109
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• 2019

Business utilization of holograms is widely used as a similar hologram. The use of holograms has been proposed in many cases. In this paper, we present an outline of similar holograms using up to 3 or 4 facets, and express the similar holograms using the results produced by 3D modeling for a building from dealing with the representation of buildings from hololens to pseudo-hologram by using 3D modeling results. In addition, to reflect the real image of the disadvantage of modeling, we propose a method to enhance the 3D expression of the object by reflecting the actual building surface on the 3D model through photographing. Virtual building seen by the human eye can be virtually shown in space through a hologram among various methods shown in a virtual space such as AR / VR / MR. Through this study, it will be possible to express holograms of various materials such as buildings or cultural properties with enhanced realism.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05b
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• pp.1457-1460
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• 2003

자바는 플랫폼에 독립적인 실행을 위해서 바이트코드를 사용하며, 자바가상머신에서 바이트코드를 해석하여 실행시키는 인터프리터 방식을 취하고 있으므로 느린 실행 시간을 갖는다. 이와 같은 느린 실행 시간에 영향을 주는 요인 중의 하나로써 다차원 배열(Multi-dimension Array)에 접근(Acess)할 때 비효율적인 방법으로 실행되는 것을 개선할 필요가 있다. 자바가상머신에서 오브젝트와 배열은 레퍼런스에 의해서 접근되어지고, 특히 다차원 배열은 배열 안에 또 다른 배열이 들어있는 자료구조를 취하기 때문에 다차원 배열의 크기가 커질수록 하나의 원소에 접근할 때 발생되는 레퍼런스(Reference)의 횟수가 많아질수록 성능 저하를 유발한다. 본 논문에서는 다차원 배열에 효율적으로 접근하기 위한 새로운 배열의 자료 구조를 제시하고, 다차원 배열에 접근하는 여러 개의 바이트코드 대신 이런 자료구조에 접근할 수 있는 새로운 바이트코드를 정의 및 구현하였다. 그리고 이를 실제 클래스파일에 적용하고, 간단한 성능 평가를 통해서 성능 개선 효과를 확인할 수 있다.