• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.2 s.233
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• pp.247-252
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• 2005

This research presents a three-dimensional modeling technique for a flexible sheet. A relative coordinate formulation is used to represent the kinematics of the sheet. The three-dimensional flexible sheet is modeled by multi-rigid bodies interconnected by out-of-plane joints and plate force elements. A parent node is designated as a master body and is connected to the ground by a floating joint to cover the rigid motion of the flexible sheet in space. Since the in-plane deformation of a sheet such as a paper and a film is relatively small, compared to out-of-plane deformation, only the out-of-plane deformation is accounted for in this research. The recursive formulation has been adopted to solve the equations of motion efficiently. An example is presented to show the validity of the proposed method.

• Journal of Mechanical Science and Technology
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• v.19 no.spc1
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• pp.305-311
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• 2005

This research presents a three-dimensional modeling technique for a flexible sheet. A relative coordinate formulation is used to represent the kinematics of the sheet. The three-dimensional flexible sheet is modeled by multi-rigid bodies interconnected by out-of-plane joints and plate force elements. A parent node is designated as a master body and is connected to the ground by a floating joint to cover the rigid motion of the flexible sheet in space. Since the in-plane deformation of a sheet such as a paper and a film is relatively small, compared to out-of-plane deformation, only the out-of-plane deformation is accounted for in this research. The recursive formulation has been adopted to solve the equations of motion efficiently. An example is presented to show the validity of the proposed method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.573-576
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• 2005

This research presents a three-dimensional modeling technique for a flexible sheet. A relative coordinate formulation is used to represent the kinematics of the sheet. The three-dimensional flexible sheet is modeled by multi-rigid bodies interconnected by out-of-plane joints and plate force elements. A parent node is designated as a master body and is connected to the ground by a floating joint to cover the rigid motion of the flexible sheet in space. Since the in-plane deformation of a sheet such as a paper and a film is relatively small, compared to out-of-plane deformation, only the out-of-plane deformation is accounted for in this research. The recursive formulation has been adopted to solve the equations of motion efficiently. An example is presented to show the validity of the proposed method.

• Journal of Digital Convergence
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• v.19 no.8
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• pp.195-203
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• 2021

This study is about building an exercise training system that analyzes images taken of a person's whole body and displays the normal operating range for user-specific movements as images. This study analyzes the front and side of the user's body based on the standing point, sets the node in the joint position of the human body, and places the node in the spatial coordinate system from the point of entry, and calibrates the normal node operating range according to the set standard node coordinate. Therefore, the method of the study presented a method to select differentiation from this study through prior technical research and literature research, and the purpose of the study is to establish a exercise training system accordingly.

• Journal of Korea Multimedia Society
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• v.10 no.12
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• pp.1733-1740
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• 2007

In this paper, we propose a wireless location-based routing algorithm which uses the location information of its neighbor nodes and a destination node. At first, the proposed routing algorithm forwards a packet to the X direction by selecting a closest node to its destination as a next hop in terms of the X coordinate until the packet reaches closely to the packet's destination. Then the packet is forwarded to the Y direction by selecting a closest node to its destination in terms of the Y coordinate. We use a back off mechanism in case that a next hop cannot be found using the proposed routing algorithm, which resolves loops while forwarding. The experimental results show that the proposed routing algorithm performs well like the existing routing algorithms Ad hoc On-demand Distance Vector and Greedy Perimeter Stateless Routing. It is expected to use the proposed routing algorithm in the digital battlefield of military environments and survival games of commercial environments.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.1529-1532
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• 2004

A Mobile Ad Hoc NETwork (MANET) is a collection of wireless mobile nodes that forms a temporary network without the need for any existing network infrastructure or centralized administration. Therefore, such a network is designed to operate in a highly dynamic environment due to node mobility. In mobile ad hoc network, frequent topological changes cause routing a challenging problem and without the complete view of the network topology, establishing the shortest path from the source node to the destination node is difficult. In this paper, we suggest a routing approach which utilizes location information to setup the shortest possible path between the source node and the destination node. Location information is obtained through Global Positioning System (GPS) and this geographical coordinate information of the destination node is used by the source node and intermediate nodes receiving route request messages to determine the shortest path to the destination from current node.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.6
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• pp.124-136
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• 2019

Autonomous driving at intersections requires assistance by exchanging traffic information between traffic objects due to the intersection of various vehicles and complicated driving environment. For this reason, traffic information exchange between adjacent intersections is required, but the node ID representing the intersection in the Korean standard node link system have limitations in updating intersections and identifying location information of intersections through IDs due to the configuration system including serial numbers. In this paper, we designed a coordinate-based intersection ID configuration system created by processing and merging two-dimensional coordinates of intersections to include location information in the intersection ID. In order to verify the applicability of the proposed intersection ID, we applied a new intersection ID to domestic intersections and confirmed that there are no duplicate values. Coordinate-based intersection ID reduces data size by 60% compared to existing node ID, and enables spatial queries such as searching for nearby intersections and extracting intersections in specific areas in the form of boxes without GIS tools. Therefore, coordinate-based intersection ID is expected to be more scalable and utilized than existing node ID.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.12
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• pp.58-65
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• 2008

This paper presents a new geographic distributed hash table (GDHT) for MANETs or Mesh networks, where virtual geographic protocol is used. In previous wort GDHT is applied to a network scenario based on two dimensional Cartesian coordinate system. Further, logical data space is supposed to be uniformly distributed. However, mobile node distribution in a network using virtual geographic routing is not matched to data distribution in GDHT. Therefore, if we apply previous GDHT to a virtual geographic routing network, lots of DHT data are probably located at boundary nodes of the network or specific nodes, resulting in long average-delay to discover resource (or service). Additionally, in BVR(Beacon Vector Routing) or LCR(Logical Coordinate Routing), because there is correlation between coordinate elements, we cannot use normal hash function. For this reason, we propose to use "geographic hash function" for GDHT that matches data distribution to node distribution and considers correlation between coordinate elements. We also show that the proposed scheme improves resource discovery efficiently.

• Structural Engineering and Mechanics
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• v.2 no.1
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• pp.17-34
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• 1994

This paper proposes a new four node degenerated shell element. In the formulation of the new element, the assumed covariant shear strains are used to avoid the shear locking problem, and the assumed covariant membrane strains are applied to alleviate the membrane locking problem and also to improve the membrane bending performance. The assumed covariant strains are obtained from the covariant strain field defined with respect to the element natural coordinate system. This formulation enables us to obtain a shell element, which does not produce spurious singular modes, avoids locking phenomena, and excels in calculation efficiency. Several examples in this paper indicate that, despite its simplicity, the achieved accuracy and convergence are satisfactory.

• Journal of Communications and Networks
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• v.7 no.4
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• pp.429-437
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• 2005

Sensor localization has become an essential requirement for realistic applications over wireless sensor networks (WSN). In this paper we propose an ad hoc localization algorithm that is infrastructure-free, anchor-free, and computationally efficient with reduced communication. A novel combination of distance and direction estimation technique is introduced to detect and estimate ranges between neighbors. Using this information we construct unidirectional coordinate systems to avoid the reflection ambiguity. We then compute node positions using a transformation matrix [T], which reduces the computational complexity of the localization algorithm while computing positions relative to the fixed coordinate system. Simulation results have shown that at a node degree of 9 we get $90\%$ localization with $20\%$ average localization error without using any error refining schemes.