• International Journal of CAD/CAM
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• v.3 no.1_2
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• pp.51-60
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• 2003

The growth of the World Wide Web and the advances in high-speed network access have greatly changed existing CAD/CAE environment. The WWW has enabled us to share various distributed product data and to collaborate in the design process. An international standard for the product model data, STEP, and a standard for the distributed object technology, CORBA, are very important technological components for the interoperability in the advanced design and manufacturing environment. These two technologies provide background for the sharing of product data and the integration of applications on the network. This paper describes a distributed CAD/CAE environment that is integrated on the network by CORBA and product model data standard STEP. Several prototype application modules were implemented to verify the proposed concept and the test result is discussed. Finite element analysis server are further distributed into several frontal servers for the implementation of distributed parallel solution of finite element system equations. Distributed computation of analysis server is also implemented by using CORBA for the generalization of the proposed method.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.665-670
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• 2000

The paper presents the dynamic instability of a disc brake pad subjected to distributed friction forces. A brake pad can be modeled as a beam with two translational springs. The study of this prototypical model is intended to provide a fundamental understanding of disc brake pad instabilities. Governing equations of motion are derived form energy expressions and their corresponding solutions are obtained by employing the finite element method. The critical distributed friction force and the instability regions are demonstrated by changing two translational spring constants. Finally, the changes of eigen-frequencies of a beam determining instability types are investigated for various combinations of two spring constants.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.687-694
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• 1997

The anisotropy and shape of distributed piezopolymer actuator have advantages over isotropic piezo ceramic materials, since these features of PVDF can be utilized as another design variable in control application. This study is interested in the reduction of sound transmission through elastic plate into interior space by using the PVDF actuator. The plate-cavity system is adopted as a test problem. The vibration of composite plate and the sound fields through plate are analyzed by using the coupled finite element and boundary element method. Some numerical simulations are performed on sound transmission through elastic plates. To investigate the effects of anisotropy and shape of distributed piezopolymer actuator, various kinds of distributed PVDF actuators are applied in sound control simulation for isotropic and anisotropic plates. The PVDF actuators applied are different from each other in their shapes and laminate angles. The results of control simulation show that the control effectiveness of distributed PYDF actuator can be enhanced by using the coupling between shape of actuator and vibration modes of structure and the anisotropy of piezoelectric properties of PVDF.

• Korean Journal of Computational Design and Engineering
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• v.11 no.5
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• pp.384-392
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• 2006

In this research, the feasibility of distributed finite element analysis system with STEP and CORBA has been investigated. The enabling technologies such as CORBA and Java play key roles in the development of integrated and geographically distributed application software. In addition to the distribution of analysis modules, numerical solution process itself is again divided into parallel processes using multi-frontal method for computational efficiency. In contrast to the specially designed parallel process for specific hardware, CORBA-based parallel process is well suited for heterogeneous platforms over the network. The idea of Web-based distributed analysis system may be applied to the engineering ASP for design and analysis in the product development processes. We believe that the proposed approach for the analysis can be extended to the entire product development process for sharing and utilizing common product data in the distributed engineering environment, thus eventually provide basis for virtual enterprise.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.11
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• pp.890-896
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• 2002

This paper deals with the dynamic stability of a brake shoe under pulsating frictional forces. A lining part of brake systems is assumed as a distributed spring, and the supported elements of a shoe are assumed as translational springs for a constant distributed frictional force and a pulsating frictional force. Governing equations are derived by the use of the extended Hamilton's principle, and numerical results are calculated by finite element method. The critical distributed frictional force and instability regions were investigated for the change of distributed spring constants and translational spring constants.

• Structural Engineering and Mechanics
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• v.54 no.1
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• pp.69-85
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• 2015

In this paper, a receding contact problem for an elastic layer resting on two quarter planes is considered. The layer is pressed by a stamp and distributed loads. It is assumed that the contact surfaces are frictionless and only compressive traction can be transmitted through the contact surfaces. In addition the effect of body forces are neglected. Firstly, the problem is solved analytically based on theory of elasticity. In this solution, the problem is reduced into a system of singular integral equations in which contact areas and contact stresses are unknowns using boundary conditions and integral transform techniques. This system is solved numerically using Gauss-Jacobi integral formulation. Secondly, two dimensional finite element analysis of the problem is carried out using ANSYS. The dimensionless quantities for the contact areas and the contact pressures are calculated under various distributed load conditions using both solutions. It is concluded that the position and the magnitude of the distributed load have an important role on the contact area and contact pressure distribution between layer and quarter plane contact surface. The analytic results are verified by comparison with finite element results.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.10
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• pp.140-147
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• 1998

The dynamic behavior of elastically restrained beams under the action of distributed tangential forces is investigated in this paper. The beam, which is fixed at one end, is assumed to rest on an intermediate spring support. The governing equations of motion are derived from the energy expressions, and the finite element formulation is employed to calculate the critical distributed tangential force. Jump phenomena for the critical distributed tangential force and instability types are presented for various spring stiffnesses and support positions. Stability maps are generated by performing parametric studies to show how the distributed tangential forces affect the frequencies and the stability of the system considered. Through the numerical simulations, the following conclusioils are obtained: (i) Only flutter type instability exists for the dimensionless spring stiffness K $\leq$ 97, regardless of the position of the spring support. (ii) For the dimensionless spring stiffness K $\leq$ 98, the transition from flutter to divergence occurs at a certain position of the spring support, and the transition position moves from the free end to the free end of the beam as the spring stiffness increases. (iii) For K $\leq$ 10$^{6}$ the support condition can be regarded as a rigid support condition.

• Journal of Plant Biology
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• v.3 no.1
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• pp.26-31
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• 1960

1. Mt. Soyo is situated in the central part of Korea, approximately 37$^{\circ}$56'W. Latitude, 127$^{\circ}$4'N. Longitude. This mountain is about 530 meters above sea level, and consists mainly of granites. Above 200 meters the area is covered with oak trees (Quercus mongolica, Q. aliena) with a kind of Rhododendron (Rhododendron mucronulatum, R. schlippenbachii) as undergrowth. About 500 packets of bryophytes were collected by the writer in 1959. 2. The mosses collected in this region were of 68 species belonging to 51 genera. Those species may roughly be divided, as follows; 1) 15 species (22.1%) are distributed also in Europe and North America (Holarctic element). 2) 2 species (2.9%) occur also in Kamchatka and the Aleutians (North Pacific element). 3) 14 species (20.6%) are widely distributed every where (Cosmopolitan element). 4) 19 species (27.9%) occur also in the temperature region of the Far East (East Asiatic element). 5) 3 species (4.4%) occur also in Indomalaya and India (Tropical element). 6) 15 species (22.1%) are endemic to Japan and Korea. 3. The Hepaticae collected in this region are of 11 species belonging to 7 genera. Those may roughly be divided, as follows; 1) 4 species (36.4%) are distributed also in Europe and North America (Holarctc element). 2) 5 species (45.5%) occur also in the temperature region of the Far East (Asiatic element). 3) 1 species (9.1%) occur also in Indomlaya. 4) 1 species (9.1%) are endemic in Japan and Korea. 4. The species which are new to the flora of Korea are as follows; 1) Leucobryum glaucum (L.) Schimp. 2) Psedoleskeopsis dicurvata (Mitt.) Broth. 3) Thuidium delicatulum (Hedw.) Mitt. 4) Dolichotheca perrobustum (Broth.) Broth. 5) Brachiolejeunia sandvicensis (Gott). Evans. 6) Porella vernicosa Lindb. ssp. gracillina (Mitt.) Ando.

• 연구논문집
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• s.32
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• pp.111-120
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• 2002

In this paper, the design of a decatizing cylinder with uniformly distributed pressure in a decatizing system is investigated by using the Finite Element Method. Particularly, since deflection of a cylinder will not perform to iron the fabrics, the cylinder design insuring uniform pressure is very important. In this paper proposed two improved cylinder model obtained by changing the support type of the bean and the support location. And perform optimization with two improved cylinder model.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.423-427
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• 1997

Recently, distributed piezoelectric actuators have drawn attention due to their potential applicability within smart structures. Because they serve not only as active components but also passive components, it is difficult to estimate their characteristics accurately. In this study a finite element method based on layerwise theory has been formulated to analyze the characteristics of the distributed piezoelectric actuators. The present method has the capability to describe more refined strain distribution and more realistic boundary conditions.