• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2008.09a
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• pp.21-24
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• 2008

• Proceedings of the CALSEC Conference
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• 2004.02a
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• pp.332-335
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• 2004

Issues ·Bottom-up v.s. Top-down Development ＆ Evaluation ·Syntax-Directed v.s. Conceptual Modeling -Reusing and Easy understanding -User friendliness and Concrete Rules ·No Aligned Rules and Guidelines for Developing Document Structures from Conceptual Information Models(omitted)

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2008.09b
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• pp.21-24
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• 2008

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.04b
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• pp.397-404
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• 2000

The research of the computer-aided analysis and design of steel structures has continuously evolved. Despite the importance of connection in steel structures, the design process of connections is inefficient in present. The purpose of this study is to help engineer in connection design process. In this paper, prototype of automatic connection design module in integrated system for steel structures is proposed. The main methodology is based on bottom-up approach to simplify and formalize product model. Expert system is used to help engineer for selecting steel connection type. Object-oriented analysis and modeling will improve the expansion of knowledge-base. The design for connection was done according to the design specifications of connections of AISC

• Steel and Composite Structures
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• v.23 no.3
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• pp.339-350
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• 2017

In this paper, various nonlocal higher-order shear deformation beam theories that consider the size dependent effects in Functionally Graded Material (FGM) beam are examined. The presented theories fulfill the zero traction boundary conditions on the top and bottom surface of the beam and a shear correction factor is not required. Hamilton's principle is used to derive equation of motion as well as related boundary condition. The Navier solution is applied to solve the simply supported boundary conditions and exact formulas are proposed for the bending and static buckling. A parametric study is also included to investigate the effect of gradient index, length scale parameter and length-to-thickness ratio (aspect ratio) on the bending and the static buckling characteristics of FG nanobeams.

• Fisheries and Aquatic Sciences
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• v.1 no.1
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• pp.68-71
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• 1998

The egg structure and shape of the skin parasite, Entobdella hippoglossi from the Atlantic halibut, Hippoglossus hippoglossus was examined using scanning electronic microscope. The newly produced eggs of E. hippoglossi were yellowish in color and tetrahedral in shape. The eggs were entwined together in a complicated chain-like fashion by a long filament. The appendage showed the presence of buoy-like structures. The buoy-like structures on the appendage of the eggs of E. hippoglossi in the present study were totally different from other sticky droplets. It is suggested that these structures are not sticky droplets but buoys for floating eggs which have entwined together on the bottom of the sea. It seems that these buoy-like structures may be needed for preventing the eggs from being covered by mud or particles and thus maintaining the eggs in an oxygenated environment.

• Journal of Welding and Joining
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• v.28 no.5
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• pp.58-63
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• 2010

The purpose of this study is to develop improved boom structures with reliable fatigue strength of weldment and lower production cost. For that purpose, multibody dynamic analysis was performed to evaluate forces acting on arm & boom cylinders and joints of boom structure during operation of an excavator for three working postures, then stress analysis was made to investigate stress distribution around diaphragms at the bottom plate of boom structures which was known to be susceptible to fatigue failures of welded joints, and finally boom structure with optimum arrangement of diaphragms was proposed. This work basically consists of the following two parts: part 1 focuses on multibody dynamic analysis of excavators during operation and part 2 includes evaluations of fatigue strength of welded joints for modified boom structures.

• Ocean Systems Engineering
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• v.12 no.3
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• pp.285-300
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• 2022

This paper adopts the Smoothed Particle Hydrodynamics (SPH) open-source code SPHinXsys to study the solitary wave interaction with coastal structures. The convergence properties of the model in terms of particle size and smoothing length are tested based on the example of solitary wave propagation in a flat-bottom wave flume. After that, the solitary wave interactions with a suspended submerged flat plate and deck with girders are studied. The wave profile and velocity field near the surface of the structures, as well as the wave forces exerted onto the structures are analyzed.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.1
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• pp.93-98
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• 2013

In this paper, We have fabricated PMMA thin films by plasma polymerization method for organic thin film transistor's insulator layer. For improving the characteristics of organic transistor, we tested transistor's mobility and output values with organic transistor's electrode structures. As a results, the mobility of top contact was $8{\times}10^{-3}[cm^2V^{-1}s^{-1}]$, that of bottom contact was $2{\times}10^{-4}[cm^2V^{-1}s^{-1}]$. Also, off current of bottom contact was increased. Therefore, we recommend the top contact electrode structure of organic transistor.

• Journal of the Korea Concrete Institute
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• v.12 no.2
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• pp.3-11
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• 2000

There is a possibility of poor-state concrete filling condition due to segregation and interlocking of aggregate and paste when a high performance concrete is used at reinforced concrete structure without compaction. This study was conducted to evaluate the flexural behavior of high performance concrete beams with design parameters such as c, t and different concrete filling conditions. Different concrete filling conditions were intentionally made such that the first type specimen was soundly cast to obtain the perfect concrete filling condition. Second type was cast in such a way that up to the longitudinal tensile reinforcement from the top, good concrete was filled while poor concrete was poured for the bottom part to simulate the poor strength, workability and unsatisfactory compaction. Third type was cast in such a was that up to the neutral axis of the beam section from the top, good concrete was filled while so did for the bottom part as the second type. The test results were analyzed in terms of load-displacement response, failure pattern, crack width and crack spacing. The test results indicate that have no effect of concrete filling conditions on the yielding strength of structures. But, have a grate influence on the stiffness and ductility of structures.