• Journal of Advanced Marine Engineering and Technology
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• v.36 no.4
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• pp.512-519
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• 2012

This paper proposes a 3-D pose (positions and orientations) estimation system based on the recognition of circular ring patterns. To deal with monocular vision-based pose estimation problem, we specially design a circular ring pattern that has a simplicity merit in view of object recognition. A pose estimation procedure is described in detail, which utilizes the geometric transformation of a circular ring pattern in 2-D perspective projection space. The proposed method is evaluated through the analysis of accuracy and precision with respect to 3-D pose estimation of a quadrotor-type vehicle in 3-D space.

• Journal of Korea Multimedia Society
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• v.5 no.5
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• pp.599-607
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• 2002

The octree model, a hierarchical volume description of 3D objects, nay be utilized to generate projected images from arbitrary viewing directions, thereby providing an efficient means of the data base for 3D object recognition and other applications. We present 2D projected image and made pseudo gray image of object using octree model and multi level boundary search algorithm. We present algorithm for finding feature points of 2D and 3D image and finding matched points using geometric transformation. The algorithm is made of data base, it will be widely applied to 3D object modeling and efficient feature points application for basic 3D object research.

• Korea-Australia Rheology Journal
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• v.17 no.3
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• pp.99-110
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• 2005

This work presents results of finite element analysis of isothermal incompressible creeping viscoelastic flows with the tensor-logarithmic formulation of the Leonov model especially for the planar geometry with singular comers in the domain. In the case of 4:1 contraction flow, for all 5 meshes we have obtained solutions over the Deborah number of 100, even though there exists slight decrease of convergence limit as the mesh becomes finer. From this analysis, singular behavior of the comer vortex has been clearly seen and proper interpolation of variables in terms of the logarithmic transformation is demonstrated. Solutions of 4:1:4 contraction/expansion flow are also presented, where there exists 2 singular comers. 5 different types spatial resolutions are also employed, in which convergent solutions are obtained over the Deborah number of 10. Although the convergence limit is rather low in comparison with the result of the contraction flow, the results presented herein seem to be the only numerical outcome available for this flow type. As the flow rate increases, the upstream vortex increases, but the downstream vortex decreases in their size. In addition, peculiar deflection of the streamlines near the exit comer has been found. When the spatial resolution is fine enough and the Deborah number is high, small lip vortex just before the exit comer has been observed. It seems to occur due to abrupt expansion of the elastic liquid through the constriction exit that accompanies sudden relaxation of elastic deformation.

• Transactions of Materials Processing
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• v.18 no.3
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• pp.236-244
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• 2009

In response to growing environmental and collision-safety concerns, the automotive industry has gradually used high-strength and ultla-high-strength steels to reduce the weight of automobiles. In order to overcome inherent process disadvantages of these materials such as poor formability and high springback at room temperature, hot forming has recently been developed and adopted to produce some important structural parts in automobiles. This method enables manufacturing of components with complex geometric shapes with minimal springback. In addition, a quenching process may enhance the material strength by more than two times. This paper investigates mechanical and forming characteristics of high-strength boron-alloyed steel with hot forming, in terms of hardness, microstructure, residual stress, and springback. In order to compare with experimental results, a finite element analysis of hot forming process coupled with phase transformation and heat transfer was carried out using DEFORM-3D V6.1 and also, to predict high temperature mechanical properties and flow curves for different phases, a material properties modeler, JMatPro was used.

• Journal of Fashion Business
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• v.22 no.2
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• pp.107-117
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• 2018

Nettle fiber, a sustainable fiber, was applied to the fabrication of denim to identify changes in textile appearance and formation. For the weaving of nettle denim, nine specimens, distinguished by three kinds of composite use of nettle fiber and three stages of fabrication processes, were used. The kinetic characteristics of the nine specimens were measured by the KES-FB system, and the images of the specimens of finished denim textiles, captured with a CCD Camera, were analyzed. In terms of the extensibility (EM) of nettle denim, all specimens showed post-processing increase, thereby suggesting an easy transformation of the textile as a source material for denim fabric. The effects of washing on the woven formation of denim were also identified. The geometric roughness (SMD), the problematic property of bast-fiber-like nettle fiber, was found to be decreased by washing. In terms of the bending rigidity (B) of the textile, the post-processing shrinking percentage of elastic nettle denim was found to decrease; all specimens that underwent bio-washing only also manifested that post-processing elasticity increased. To improve the draping of nettle denim, a mixed spinning together with washing were found to be advantageous. In terms of the shear stiffness (G), which is closely associated with the appearance of clothes, the formation of textile was improved regardless of the types of processing, including bio-washing and bleach washing.

• Journal of Advanced Marine Engineering and Technology
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• v.23 no.4
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• pp.504-513
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• 1999

Usually bellows are designed for the purpose of absorbing axial movement. To find out axial stiffness of bellows the axisymmetric shell theory using the finite element method is adopted in this paper. Bellows can be idealised by series of conical frustum-shaped elements because it is axisymmetric shell structure. The force required to deflect bellows axilly is a function of the dimensions of the bellows and the materials from which they are made. The displancements of nodal points due to small increment of force are calculated by the finite element method and the calculated nodal displacements are added to r-z cylinderical coordinates of nodal points. The new stiffness matrix of the system using the new coordinates of nodal points is adopted to calculate the another increments of nodal dis-placements that is the step by method is used in this paper. spring constant is analyzed according to the changing geometric factors of u-shaped bellows. The FEM results were agreed with experiment. Using developed FORTRAN PROGRAM spring constant can be predicted by input of a few factors.

• Journal of Advanced Marine Engineering and Technology
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• v.23 no.5
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• pp.702-710
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• 1999

U-shaped bellows are usually used to piping system pressure sensor and controller for refriger-ator. Bellows subjected to internal pressure are designed for the purpose of absorbing deformation. Internal pressure on the convolution sidewall and end collar will be applied to an axial load tend-ing to push the collar away from the convolutions. To find out deformation behavior of bellow sub-jected to internal pressure the axisymmetric shell theory using the finite element method is adopted in this paper. U-shaped bellows can be idealized by series of conical frustum-shaped ele-ments because it is axisymmetric shell structure. The displacements of nodal points due to small increment of force are calculated by the finite element method and the calculated nodal displace-ments are added to r-z cylindrical coordinates of nodal points. The new stiffness matrix of the sys-tem using the new coordinates of nodal points is adopted to calculate the another increments of nodal displacement that is the step by step method is used in this paper. The force required to deflect bellows axially is a function of the dimensions of the bellows and the materials from which they are made. Spring constant is analyzed according to the changing geometric factors of U-shaped bellows. The FEM results were agreed with experiment. Using developed FORTRAN PROGRAM the internal pressure vs. deflection characteristics of a particu-lar bellows can be predicted by input of a few factors.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.9
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• pp.909-915
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• 2009

This work is to develop a vision system for high precision alignment between upper and lower plates required at the imprinting process of the large LCD flat panel. We compose a gantry-stage that has highly repeated accuracy for high precision alignment and achieves analysis about thermal transformations of stage itself. Position error in the stage is corrected by feedback control from the analysis. This system can confirm alignment mark of upper and lower plates by using two cameras at a time for the alignment of two plates. Pattern matching that uses geometric feature is proposed to consider the recognition problem for alignment mark of two plates. It is algorithm to correct central point and angle for the alignment from the recognized mark of upper and lower plates based on the special characteristics. At the alignment process, revision for error position is performed through Look and Move techniques.

• Structural Engineering and Mechanics
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• v.11 no.4
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• pp.423-442
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• 2001

This paper presents a method of elastic-plastic analysis for planar steel frames that provides the accuracy of distributed plasticity methods with the computational efficiency that is greater than that of distributed plasticity methods but less than that of plastic-hinge based methods. This method accounts for the effect of spread of plasticity accurately without discretization through the cross-section of a beam-column element, which is achieved by the following procedures. First, nonlinear equations describing the relationships between generalized stresses and strains of the cross-section are derived analytically. Next, nonlinear force-deformation relationships for the beam-column element are obtained through lengthwise integration of the generalized strains. Elastic-plastic flexibility coefficients are then calculated by differentiating the above element force-deformation relationships. Finally, an elastic-plastic stiffness matrix is obtained by making use of the flexibility-stiffness transformation. Adding the conventional geometric stiffness matrix to the elastic-plastic stiffness matrix results in the tangent stiffness matrix, which can readily be used to evaluate the load carrying capacity of steel frames following standard nonlinear analysis procedures. The accuracy of the proposed method is verified by several examples that are sensitive to the effect of spread of plasticity.

• Journal of The Korean Digital Architecture Interior Association
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• v.8 no.1
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• pp.65-74
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• 2008

Light creates ambiance that affects our impression of space. Before the modern age, the role of light is a religious factor and a primitive state to see. In the modern space design, light is used to achieve the continuous transformation and translation of building's image. Ever-changing space is a flexible corresponding of space to its environment, caused by certain dynamic light. The space turn into some other thing from what it was before, or just changing its character. approaching men and society with different meanings. The purpose of this study is to explore the relation between light(natural and artificial) and ever-changing space through the case study. The impacts of light on ever-changing in today's space design can be summarized as follows. 1) Materialization of light in space design. Nowadays light becomes a form itself. The geometric properties of the space form playa secondary role as compared to the importance assigned to light. 2) Pixelization of space by a light effect. The impacts of digital technology on the space design have come through enhancing the 'pixelization' of the surface from which buildings are made their responsiveness and adaptability to changing needs. The surface with ever-changing lights that blur the boundary of space and expand the image of space.