• Structural Engineering and Mechanics
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• v.16 no.4
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• pp.423-440
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• 2003

Arbitrary Lagrangian Eulerian finite element methods gain interest for the capability to control mesh geometry independently from material geometry, the ALE methods are used to create a new undistorted mesh for the fluid domain. In this paper we use the ALE technique to solve fuel slosh problem. Fuel slosh is an important design consideration not only for the fuel tank, but also for the structure supporting the fuel tank. "Fuel slosh" can be generated by many ways: abrupt changes in acceleration (braking), as well as abrupt changes in direction (highway exit-ramp). Repetitive motion can also be involved if a "sloshing resonance" is generated. These sloshing events can in turn affect the overall performance of the parent structure. A finite element analysis method has been developed to analyze this complex event. A new ALE formulation for the fluid mesh has been developed to keep the fluid mesh integrity during the motion of the tank. This paper explains the analysis capabilities on a technical level. Following the explanation, the analysis capabilities are validated against theoretical using potential flow for calculating fuel slosh frequency.

• International Journal of Advanced Culture Technology
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• v.10 no.4
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• pp.555-560
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• 2022

In this study, the insertion loss and phase delay according to the multi-layer structure radome parameters were analyzed using the boundary value solution approach, and the multi-layer structure and hexa mesh structures with low-loss electrical characteristics for the Ku-band transmission/reception frequency of 10.7 ~ 14.5 GHz were designed and manufactured. A hexa mesh was applied to minimize radio wave transmission and scattering, which lowered the transmittance refractive index according to the radio incident angle and minimized dielectric loss through high-density foam. Similar to the simulation result, the transmission loss obtained the gain in a specific receiving frequency band, and in the transmission frequency band, an excellent low loss characteristic was obtained with an insertion loss of 0.8dB or less. The results of this study can be used in radio transmission radomes of low-weight, low-cost end-system protection devices.

• The Research Journal of the Costume Culture
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• v.25 no.6
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• pp.880-892
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• 2017

In this study, the appearance change and the heat moisture transfer properties of knitted fabric by yarn shrinkage were examined to obtain useful data on the development of thermo-sensitive functional materials. Eleven types of knitted fabric were knitted using highly bulky acrylic-blended yarn. After shrinking the specimens using dry heat treatment, the appearance change and thickness were measured. An HEC simulator was adopted for measuring the heat moisture transfer properties of specimens by yarn shrinkage. When holes were arranged vertically in the mesh structure, the specimens with 2,500 and 5,000 holes showed high percent change of hole area, appearance, and thickness. When holes were diagonally arranged in the mesh structure, the percent change of hole area in the specimen with 1,250 holes was larger than the one with 2,500 holes. However, the dimensional stability of the specimen with 2,500 holes was better because of its smaller appearance and thickness change. In the tuck structure, the percent change of hole area in the specimen with 625 and 416 holes was relatively large compared with the appearance and thickness change. Furthermore, the hole size in the tuck structure was smaller than that in the mesh structure but the percent change of hole area was larger. Therefore, it was proved that the tuck structure is more suitable than the mesh structure for developing thermo-sensitive functional materials. Heat moisture transfer property test verified that the change of hole area by yarn shrinkage enabled obtaining the thermal effect due to the distinct temperature difference in the inner layer.

• Journal of Korea Multimedia Society
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• v.13 no.12
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• pp.1748-1759
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• 2010

We extend the octree subdivision process from Cartesian coordinates to spherical coordinates to develop more efficient space-partitioning structure for surface models. As an application of the proposed structure, we apply the octree subdivision in spherical coordinates ("S-Octree") to geometry compression in progressive mesh coding. Most previous researches on geometry-driven progressive mesh compression are devoted to improve predictability of geometry information. Unlike this, we focus on the efficient information storage for the space-partitioning structure. By eliminating void space at initial stage and aligning the R axis for the important components in geometry information, the S-Octree improves the efficiency in geometry information coding. Several meshes are tested in the progressive mesh coding based on the S-Octree and the results for performance parameters are presented.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.2
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• pp.35-50
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• 2013

This paper discusses effects of mesh planes on signal integrity in high-speed glass ceramic packages. One of serious signal integrity issues in high-speed glass ceramic packages is high far-end (FE) noise coupling between signal interconnects. Based on signal integrity analysis, a methodology is presented for reducing far-end noise coupling between signal interconnects in high-speed glass ceramic modules. This methodology employing power/ground mesh planes with alternating spacing and a via-connected coplanar-type shield (VCS) structure is suggested to minimize far-end noise coupling between signal lines in high-speed glass ceramic packages. Optimized interconnect structure based on this methodology has demonstrated that the saturated far-end noise coupling of a typical interconnect structure in glass ceramic modules could be reduced significantly by 73.3 %.

• Journal of Information Processing Systems
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• v.20 no.3
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• pp.328-336
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• 2024

Visual communication is widely used and enhanced in modern society, where there is an increasing demand for spirituality. Museum robots are one of many service robots that can replace humans to provide services such as display, interpretation and dialogue. For the improvement of museum guide robots, the paper proposes a human-robot interaction system based on visual communication skills. The system is based on a deep neural mesh structure and utilizes theoretical analysis of computer vision to introduce a Tiny+CBAM mesh structure in the gesture recognition component. This combines basic gestures and gesture states to design and evaluate gesture actions. The test results indicated that the improved Tiny+CBAM mesh structure could enhance the mean average precision value by 13.56% while maintaining a loss of less than 3 frames per second during static basic gesture recognition. After testing the system's dynamic gesture performance, it was found to be over 95% accurate for all items except double click. Additionally, it was 100% accurate for the action displayed on the current page.

• Journal of Korean Association for Spatial Structures
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• v.7 no.3 s.25
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• pp.153-165
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• 2007

Flexible structure uses a material with strong axial stiffness and small bending stiffness as its major structural material so it is very sensitive to initial stiffness. Therefore, the self-formation process which accomplishes a form in the natural world is grasped and it is as well investigated and classified the type of modeling techniques which are available to find the shapes of soft structures. Accordingly, for analysis and design of flexible structure, three-step analysis such as shape analysis, stress-deformation analysis, cutting pattern generation and constructional analysis is required unlike the existing stiff structure. In this study, suggest that minimize the error of side curvatures by the triangle Re-mesh pattern and draw the cutting pattern generation.

• Journal of Navigation and Port Research
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• v.28 no.8
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• pp.673-678
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• 2004

The ENC standard, S-57 Specification was established to exchange hydrographic data between it's users such as HOs ECDIS users, etc. The digital navigation chart which is produced according to the S-57 Specification is called an ENC(Electronic Navigational Chart) and the SENC(System ENC) is a by-product of ENC suitable for computer graphics system Even though the efficient structure of SENC is a key element of measuring ECDIS performance, the amount of papers about these topics are small compared with other research fields. In this paper, the author designed an efficient spatial data structure of SENC, called Mesh This paper also includes the implementation result of the 'Mesh' which displays SENC on computer screen.

• Structural Engineering and Mechanics
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• v.45 no.3
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• pp.411-422
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• 2013

A well-designed mesh shape of the cable net is of essential significance to achieve high performance of cable-network antenna reflectors. This paper is concerned with the mesh design problem for such antenna reflector structure. Two new methods for creating the topological forms of the cable net are first presented. Among those, the cyclosymmetry method is useful to generate different polygon-faceted meshes, while the topological mapping method is suitable for acquiring triangle-faceted meshes with different mesh grid densities. Then, the desired spatial paraboloidal mesh geometrical configuration in the state of static equilibrium is formed by applying a simple mesh generation approach based on the force density method. The main contribution of this study is that a general technical guide for how to create the connectivities between the nodes and members in the cable net is provided from the topological point of view. With the new idea presented in this paper, multitudes of mesh configurations with different net patterns can be sought by a certain rule rather than by empiricism, which consequently gives a valuable technical reference for the mesh design of this type of cable-network structures in the engineering.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.5
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• pp.959-975
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• 2011

Wireless mesh networks enlarge the wireless coverage area by interconnecting relatively stationary wireless routers (mesh routers). As wireless mesh networks are envisioned to provide high-bandwidth broadband Internet service to a large community of users, the Internet gateway, which acts as a central point of Internet attachment for the mesh networks, is likely to suffer heavily from the scramble for shared wireless resources because of aggregated traffic toward the Internet. It causes performance decrement on end-to-end transmissions. We propose a scheme to balance the load in a mesh network based on link quality variation to different Internet gateways. Moreover, under the mesh coverage, mobile nodes can move around and connect to nearby mesh routers while still keeping the connections to the Internet through the best gateway in terms of link quality. In this structure, gateways perform the balancing procedure through wired links. Information about gateways and mobile node's location is distributed appropriately so that every mesh router can quickly recognize the best gateway as well as the positions of mobile nodes. This distributed information assists mobile nodes to perform fast handoff. Significant benefits are shown by the performance analysis.