• Coupled systems mechanics
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• v.11 no.4
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• pp.297-313
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• 2022

The objective of this paper is to study the effect of frequency in a two-dimensional orthotropic thermoelastic rotating solid with fractional order heat transfer in generalized thermoelasticity with two-temperature due to inclined load. As an application the bounding surface is subjected to uniformly and linearly distributed loads (mechanical and thermal source). The problem is solved with the help of Fourier transform. Assuming the disturbances to be harmonically time dependent, the expressions for displacement components, stress components, conductive temperature and temperature change are derived in frequency domain. Numerical inversion technique has been used to determine the results in physical domain. The results are depicted graphically to show the effect of frequency on various components. Some particular cases are also discussed in the present research.

• Coupled systems mechanics
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• v.13 no.1
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• pp.21-41
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• 2024

This paper is concerned with the disturbances in a transversely isotropic new modified couple stress homogeneous thermoelastic rotating medium under the combined influence of Hall currents, magnetic fields, and mechanical sources represented by inclined loads. The application of Laplace and Fourier transform techniques are used for the derivation of analytical expressions for various physical quantities. As an application,the bounding surface is subjected to uniformly and linearly distributed force (mechanical force). Present model contains length scale parameters that can capture the size effects. Numerical inversion techniques has been used to provide insights into the system's behavior in the physical domain. The graphical representation of numerical simulated results has been presented to emphasize the impact of rotation and inclined line loads on the system, enhancing our understanding of the studied phenomena. Further research can extend this study to investigate additional complexities and real-world applications.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.1-4
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• 2005

A higher order zig-zag shell theory is developed to refine accurately predict deformation and stress of smart shell structures under the mechanical, thermal, and electric loading. The displacement fields through the thickness are constructed by superimposing linear zig-zag field to the smooth globally cubic varying field. Smooth parabolic distribution through the thickness is assumed in the transverse deflection in order to consider transverse normal deformation. The mechanical, thermal, and electric loading is applied in the sinusoidal distribution function in the in-surface direction. Thermal and electric loading is given in the linear variation through the thickness. Especially, in electric loading case, voltage is only applied in piezo-layer. The layer-dependent degrees of freedom of displacement fields are expressed in terms of reference primary degrees of freedom by applying interface continuity conditions as well as bounding surface conditions of transverse shear stresses. In order to obtain accurate transverse shear and normal stresses, integration of equilibrium equation approach is used. The numerical examples of present theory demonstrate the accuracy and efficiency of the proposed theory. The present theory is suitable for the predictions of behaviors of thick smart composite shell under mechanical, thermal, and electric loadings combined.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.3
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• pp.636-644
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• 2010

A method for the detection of on-road succeeding vehicles using visual characteristic features like horizontal edges, shadow, symmetry and intensity is proposed. The proposed method uses the prominent horizontal edges along with the shadow under the vehicle to generate an initial estimate of the vehicle-road surface contact. Fast symmetry detection, utilizing the edge pixels, is then performed to detect the presence of vertically symmetric object, possibly vehicle, in the region above the initially estimated vehicle-road surface contact. A window defined by the horizontal and the vertical line obtained from above along with local perspective information provides a narrow region for the final search of the vehicle. A bounding box around the vehicle is extracted from the horizontal edges, symmetry histogram and a proposed squared difference of intensity measure. Experiments have been performed on natural traffic scenes obtained from a camera mounted on the side view mirror of a host vehicle demonstrate good and reliable performance of the proposed method.

• Journal of Korea Game Society
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• v.10 no.1
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• pp.157-165
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• 2010

This paper presents a novel real-time rendering algorithm based on spherical coordinate system of the object using convex hull. While OpenGL rendering pipeline touches all vertices of an object, the proposed method takes account the only visible vertices by examining the visible triangles of the object. In order to determine the visible areas of the object in its spherical coordinate representation, the proposed method uses 3D geometric relation of 6 plane equations of the camera frustum and the bounding sphere of the object. In addition, we compute the convex hull of the object and its maximum side factors for hidden surface removal. Simulation results showed that the quality of result image is almost same compared to original image and rendering performance is greatly improved.

• Geotechnical Engineering
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• v.12 no.5
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• pp.17-26
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• 1996

The undrained behavior of Asan marine soil was investigated by using an automated triaxial testing device. The stress-strain behavior at the preand postfailure state of marine soil under undrained compression and eatension conditions was compared with the behavior of pure silt, pure clay and the overall behavior of Asan marine soil was predicted with the modified Camflay model and the bounding surface model. The marine soil sampled in Asan bay area was clayey silts with 70oA silt-30% clay content and the testing samples were prepared in both undisturbed and remolded conditions. All samples are normally consolidated with 400 kPa of effective mean confining pressure and each sample is unloaded to 200, 100, 67 kPa, respectively. And then the shear test was performed with different confining pressure. According to experimental results, there exists an unique failure line whose slope is lower than silt's and higher than clay's. It is identified that the undrained shear strength of normally consolidated samples increases after crossing the phase transformation line because of volume dilation tendency which is not seen in clay. Overconsolidated samples show different soil behavior compared with pure silt due to its tendency of change in volume. It is also found that the overall behavior of Asan marine soil cannot be predicted precisely with the modified Cam-clay model and the bounding surface model.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.6
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• pp.683-694
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• 2009

High-resolution (Chirp and Sparker system) seismic profiles were analyzed to investigate the sedimentary sequence and distribution pattern of the late Holocene deposits in Gyunggi Bay, the Yellow Sea. The bay is located in the western part of Korea, east of the Yellow Sea. The sedimentary sequence divided into three units bounded by erosional bounding surface: (1) acoustically parallel to subparallel reflectors with cross bedding structures (Unit 1); (2) confused inner reflectors and top of unit exposed partially at the seafloor (Unit 2); and (3) approximately parallel reflections and regressive to transgressive incision-fills (Unit 3). On the basis of seafloor morphology, surface bedforms, and subbotom acoustic characters, echo types in the study area were identified following the schemes of Chough et al. (2002); (1) flat seafloor with sharp bottom echoes (echo types 1-1, 1-2 and 1-3; transgressive sediment sheets or relict sands), (2) mounded seafloor with either smooth surface or superposed bedforms (echo types 2-1 and 2-2; tidal ridges), and (3) various-scale eroded seafloor (echo types 3-1 and 3-2; channels). Suspect features of acoustic turbid zones which is related to gas charged sediment are reported.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.708-712
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• 2007

In computer graphics, fluid dynamics are used for animating and expressing the various special effects of water. Although the algorithms that were impossible through the hardware at that time become to be possible in real time, it still requires a lot of time to achieve the realistic and detailed expressions. Therefore, there are many researches on the techniques of balancing between performance and quality. Specially in environments with the game context which express the interaction between water surface and 3D objects in the wide area such as sea or lake according to user's request, it must give priority to the executive performance preserving the visual reality even though physical reality is sacrificed. In this paper, we propose a method for the realtime animation of interaction between water surface and 3D objects using the linear convolution of height fields and the bounding spheres of objects.

• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.3
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• pp.19-30
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• 1990

This note describes an application of Hamiton's principle to nonlinear free-surface flow problems. Two functionals are constructed based on classical Hamilton's principle with a modification due to the presence of a free surface. As an effort towards the development of an efficient numerical scheme for our problem, we present the following three test results: i) The bounding principles of the eigenvalues for the linear dispersion relation. ii) By assuming steady solitary waves, an approximate relation between the amplitudes and the speeds of solitary waves are derived from the two functionals constructed. Their numerical results are compared with those of Longuet-Higgins & Fenton(1974). iii) The shapes and charicteristics of solitary waves are computed from two sets of functionals by varying the number of total finite elements in the fluid domain.

• Journal of Environmental Science International
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• v.13 no.8
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• pp.721-731
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• 2004

The dispersion of suspended particulates in the coastal complex terrain of mountain-inland basin (city)-sea, considering their recycling was investigated using three-dimensional non-hydrostatic numerical model and lagrangian particle model (or random walk model). Convective boundary layer under synoptic scale westerly wind is developed with a thickness of about I km over the ground in the west of the mountain, while a thickness of thermal internal boundary layer (TIBL) is only confined to less than 200m along the eastern slope of the mountain, below an easterly sea breeze circulation. At the mid of the eastern slop of the mountain, westerly wind confronts easterly sea breeze, which goes to the height of 1700 m above sea level and is finally eastward return flow toward the sea. At this time, particulates floated from the ground surface of the city to the top of TIBL go along the eastern slope of the mountain in the passage of sea breeze, being away the TIBL and reach near the top of the mountain. Then those particulates disperse eastward below the height of sea-breeze circulation and widely spread out over the coastal sea. Total suspended particulate concentration near the ground surface of the city is very low. On the other hand, nighttime radiative cooling produces a shallow nocturnal surface inversion layer (NSIL) of 200 m thickness over the inland surface, but relatively thin thickness less than 100m is found near the mountain surface. As synoptic scale westerly wind should be intensified under the association of mountain wind along the eastern slope of mountain to inland plain and further combine with land-breeze from inland plain toward sea, resulting in strong wind as internal gravity waves with a hydraulic jump motion bounding up to about 1km upper level in the atmosphere in the west of the city and becoming a eastward return flow. Simultaneously, wind near the eastern coastal side of the city was moderate. Since the downward strong wind penetrated into the city, the particulate matters floated near the top of the mountain in the day also moved down along the eastern slope of the mountain, reaching the. downtown and merging in the ground surface inside the NSIL with a maximum ground level concentration of total suspended particulates (TSP) at 0300 LST. Some of them were bounded up from the ground surface to the 1km upper level and the others were forward to the coastal sea surface, showing their dispersions from the coastal NSIL toward the propagation area of internal gravity waves. On the next day at 0600 LST and 0900 LST, the dispersed particulates into the coastal sea could return to the coastal inland area under the influence of sea breeze and the recycled particulates combine with emitted ones from the ground surface, resulting in relatively high TSP concentration. Later, they float again up to the thermal internal boundary layer, following sea breeze circulation.