• Annual Conference of KIPS
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• 2003.11b
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• pp.1257-1260
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• 2003

초고속 인터넷 서비스가 보급된 이후 가입자들은 점점더 많은 서비스를 요구하게 되고, 이에 따라 더 많은 대역폭을 필요로 하게 되었다. 저렴한 비용으로 사용자들의 요구 사항을 충족시킬 수 있는 방안으로 E-PON(Ethernet-Passive Optical Network) 기반의 광가입자망에 대한 관심이 증가하고 있다. 이에 본 논문에서는 E-PON 기반 광가입자망의 핵심적인 구성 요소인 eOLT(enhanced Optical Line Termination) 시스템에서의 VLAN(Virtual Local Area Network) 서비스 요구 사항 및 제공 구조를 제시 하고자 한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1999.06a
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• pp.11-14
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• 1999

The forthcoming century will be the "era of cyber society" . In a virtual environment, a cyber character plays the role of an agent for the human being. In this paper, we introduce active researches of industries, universities, and research institutes in Korea. After Adam Soft Inc. presented a cyber singer,“Adam”, a few cyber characters have succeeded commercially through Internet, TV, CF, movies and etc. Some universities had their own characters to make fundamental researches in the fields of modeling, motion control, and VR. Research institutes have been funded recently to a cyber character related researches. This paper briefly reviews the recent research works, and future trends in Korea. in Korea.

• Advances in nano research
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• v.10 no.4
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• pp.313-325
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• 2021

This paper is concerned with the buckling behavior of 2D and quasi-3D problem of functionally graded nanobeam founded on high order shear deformation beams theory and made by two different types of porous distribution materials in Nano- and micro-scales. The used Quasi-3D formulation takes into account the transverse shear effect and uses only three variables. Both formulations do not include the correction factor that is required in the first shear deformation theory proposed by Timoshenko. Governing equations are derived using the principle of virtual work. Analytical resolutions for buckling of FG nanobeam are introduced under tow different boundary conditions, and the results obtained are compared to those proposed in literatures.

• Annual Conference of KIPS
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• 2020.11a
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• pp.671-672
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• 2020

발달 장애 아동은 사회생활을 위한 언어 훈련을 진행하고 있다. 언어 훈련은 상황에 맞는 질문에 대한 답변과 행동을 위한 교육이다. 본 연구는 발달 장애 아동의 발음학습을 위해 가상상담 시스템 구축 방법론을 적용한다. 발달 장애 아동 교육을 위해서는 각 상황에 맞는 질문과 답변 등을 구성하여 교육한다. 가상상담 구축도 시나리오 형태로 시스템을 구축한다. 본 연구는 가상상담 시스템 구축 방법론을 활용하여 발달 장애 아동 발음학습을 구현하는 방법을 제시하도록 하겠다.

• Annual Conference of KIPS
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• 2008.11a
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• pp.917-919
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• 2008

WDM 네트워크에서 QoS를 향상시키기 위해서는 가상 토폴로지를 효율적으로 재구성할 수 있어야 한다. 본 연구에서는 토폴로지를 재구성할 시점을 결정하고 적절한 파장을 할당하는 기법을 제안함으로써 효과적으로 WDM 네트워크를 운영할 수 있는 WDM 컨트롤러를 제안한다.

• Geomechanics and Engineering
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• v.8 no.3
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• pp.305-321
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• 2015

In this paper, a new hyperbolic shear deformation plate theory based on neutral surface position is developed for the static analysis of functionally graded plates (FGPs). The theory accounts for hyperbolic distribution of the transverse shear strains and satisfies the zero traction boundary conditions on the surfaces of the beam without using shear correction factors. The neutral surface position for a functionally graded plate which its material properties vary in the thickness direction is determined. The mechanical properties of the plate are assumed to vary continuously in the thickness direction by a simple power-law distribution in terms of the volume fractions of the constituents. Based on the present new hyperbolic shear deformation plate theory and the neutral surface concept, the governing equations of equilibrium are derived from the principle of virtual displacements. Numerical illustrations concern flexural behavior of FG plates with Metal-Ceramic composition. Parametric studies are performed for varying ceramic volume fraction, volume fraction profiles, aspect ratios and length to thickness ratios. The accuracy of the present solutions is verified by comparing the obtained results with the existing solutions.

• Smart Structures and Systems
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• v.25 no.4
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• pp.409-422
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• 2020

This article deals with the flexural analysis of anti-symmetric cross-ply laminated plates under nonlinear thermal loading using a refined plate theory with four variables. In this theory, the undetermined integral terms are used and the number of variables is reduced to four, instead of five or more in other higher-order theories. The boundary conditions on the top and the bottom surfaces of the plate are satisfied; hence the use of the transverse shear correction factors is avoided. The principle of virtual work is used to obtain governing equations and boundary conditions. Navier solution for simply supported plates is used to derive analytical solutions. For the validation of the present theory, numerical results for displacements and stresses are compared with those of classical, first-order, higher-order and trigonometric shear theories reported in the literature.

• Wind and Structures
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• v.22 no.3
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• pp.291-305
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• 2016

In this paper, a refined shear deformation plate theory which eliminates the use of a shear correction factor was presented for FG sandwich plates composed of FG face sheets and an isotropic homogeneous core. The theory accounts for parabolic distribution of the transverse shear strains and satisfies the zero traction boundary conditions on the surfaces of the plate. The mechanical properties of the plate are assumed to vary continuously in the thickness direction by a simple power-law distribution in terms of the volume fractions of the constituents. Based on the present refined shear deformation plate theory, the governing equations of equilibrium are derived from the principle of virtual displacements. Numerical illustrations concern buckling behavior of FG sandwiches plates with Metal-Ceramic composition. Parametric studies are performed for varying ceramic volume fraction, volume fraction profiles, Boundary condition, and length to thickness ratios. The accuracy of the present solutions is verified by comparing the obtained results with the existing solutions.

• Geomechanics and Engineering
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• v.15 no.1
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• pp.711-719
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• 2018

The present work presents a free vibration and buckling analysis of orthotropic plates by proposing a novel two variable refined plate theory. Contrary to the conventional higher order shear deformation theories (HSDT) and the first shear deformation theory (FSDT), the proposed theory utilizes a novel displacement field which incorporates undetermined integral terms and involves only two unknowns. The governing equations are obtained from the dynamic version of principle of virtual works. The analytical solution of a simply supported orthotropic plate has been determined by using the Navier method. Numerical investigations are performed by employing the proposed model and the obtained results are compared with the existing HSDTs.

• Computers and Concrete
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• v.26 no.5
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• pp.439-450
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• 2020

In this research, bending and buckling analyses of porous functionally graded (FG) plate under mechanical load are presented. The properties of the FG plate vary gradually across the thickness according to power-law and exponential functions. The material imperfection is considered to vary depending to a logarithmic function. The plate is modeled by a refined trigonometric shear deformation theory where the use of the shear correction factor is unnecessary. The governing equations of the FG plate are derived via virtual work principle and resolved via Navier solutions. The accuracy of the present model is checked by comparing the obtained results with those found in the literature. The various effects influencing the stresses, displacements and critical buckling loads of the plate are also examined and discussed in detail.