• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.8
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• pp.1586-1591
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• 2011

This paper considers synchronization problem of a complex dynamical network. For the problem, the virtual target node is chosen as one of nodes in the complex network and only one connection is needed between an isolate target node and virtual target node not any more connections. Moreover, our synchronization scheme does not need additional conditions and information of coupling matrix comparing with existing works. Based on Lyapunov stability theory, a design criterion for a novel adaptive feedback controller for the synchronization between the isolate target node and another nodes of the complex network is proposed. Finally, the proposed method is applied to a numerical example in order to show the effectiveness of our results.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.6
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• pp.381-390
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• 2015

The efficient design of a transport protocol contributes to energy conservation as well as performance improvement in wireless sensor networks (WSNs). In this paper, a node-density-aware transport protocol (NDTP) for intra-cluster transmissions in WSNs for monitoring physical attributes is proposed, which takes node density into account to mitigate congestion in intra-cluster transmissions. In the proposed NDTP, the maximum active time and queue length of cluster heads are restricted to reduce energy consumption. This is mainly because cluster heads do more works and consume more energy than normal sensor nodes. According to the performance evaluation results, the proposed NDTP outperforms the conventional protocol remarkably in terms of network lifetime, congestion frequency, and packet error rate.

• Smart Media Journal
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• v.5 no.4
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• pp.41-48
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• 2016

In mobile ad hoc networks(MANETs), all the nodes in a network have limited resources. Therefore, communication topology which has long lifetime is suitable for nodes in MANETs. And MANETs are exposed to various threats because of a new node which can join the network at any time. There are various researches on security problems in MANETs and many researches have tried to make efficient schemes for reducing network power consumption. Power consumption is necessary to secure networks, however too much power consumption can be critical to network lifetime. This paper focuses on energy efficient monitoring node distribution for enhancing network lifetime in MANETs. Since MANETs cannot use centralized infrastructure such as security systems of wired networks, we propose an efficient IDS node distribution scheme using minimum spanning tree (MST) method to cover all the nodes in a network and enhance the network lifetime. Simulation results show that the proposed algorithm has better performance in comparison with the existing algorithms.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.9
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• pp.2017-2036
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• 2012

Based on the current solutions to the problem of energy hole, this paper proposed a nonuniform node distribution clustering algorithm, NNDC. Firstly, we divide the network into rings, and then have an analysis and calculation on nodes' energy consumption in each ring of the network when clustering algorithm is applied to collect data. We also put forward a scheme of nonuniform node distribution on the basis of the proportion of nodes' energy consumption in each ring, and change nodes' active/hibernating states under density control mechanism when network coverage is guaranteed. Simulation shows NNDC algorithm can satisfyingly balance nodes' energy consumption and effectively avoid the problem of energy hole.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.04a
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• pp.139-142
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• 2005

This paper describes an automatic finite element (FE) mesh generation for three-dimensional structures consisting of free-form surfaces. This mesh generation process consists of three subprocesses: (a) definition of geometric model, i.e. analysis model, (b) generation of nodes, and (c) generation of elements. One of commercial sol id modelers is employed for three-dimensional sol id structures. Node is generated if its distance from existing node points is similar to the node spacing function at the point. The node spacing function is well control led by the fuzzy knowledge processing. The Delaunay method is introduced as a basic tool for element generation. Automatic generation of FE meshes for three-dimensional sol id structures holds great benefits for analyses. Practical performances of the present system are demonstrated through several mesh generations for three-dimensional complex geometry.

• Smart Structures and Systems
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• v.20 no.6
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• pp.729-737
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• 2017

Piezoelectric composite laminates are a powerful material system that offers vast options to improve structural behavior. Successful design of piezoelectric adaptive structures and testing of control laws call for highly accurate, reliable and numerically efficient numerical tools. This paper puts focus onto linear and geometrically nonlinear static and dynamic analysis of smart structures made of such a material system. For this purpose, highly efficient linear 3-node and 4-node finite shell elements are proposed. Both elements employ the Mindlin-Reissner kinematics. The shear locking effect is treated by the discrete shear gap (DSG) technique with the 3-node element and by the assumed natural strain (ANS) approach with the 4-node element. Geometrically nonlinear effects are considered using the co-rotational approach. Static and dynamic examples involving actuator and sensor function of piezoelectric layers are considered.

• Journal of Korean Port Research
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• v.10 no.1
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• pp.25-36
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• 1996

Generally, it is pointed out that a nonlinear analysis is needed to estimate accurately the water surface fluctuation and dynamic responses of a floating structure in case of large wave reflection. In this study, a frequency-domain method is applied and newly developed to analyze the nonlinear characteristics of the air-chamber floating breakwater. The air-chamber floating breakwater in this study can control well the wave transformation, motions of the structure and its natural frequency by adjusting the air depth in the chamber. Experiments are carried out to verify the numerical results. It is appeared that the mean water level is setup in the anti-node and setdown in the node, while the nonlinearity in wave profile is larger in the node than in the anti-node. Because of vertical mooring system, the sway, especially the time-independent nonlinear component, plays predominant role in the motion. On the other hand, the time-dependent component, as well as the time-independent one to the tensile force of mooring line contributes greatly, and the time averaged value presents tensional force oriented to the onshore side due drift force.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.5
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• pp.1003-1011
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• 2009

This study was carried out to know the effects of Kwanjulbang-6(GJB-6) on the inhibition of arthritis. GJB-6 was orally administered to mouse with arthritis induced by collagen II . Cytotoxicity, hepatotoxicity, arthritis index, value of immunocyte in draining lymph node and paw joint, rheumatoid factor in serum were measured in vivo. The incidence of arthritis was significantly decreased. Total cell number of draining lymph node was significantly increased compared with control. Total cell number of paw joint was significantly decreased compared with control. The absolute number of $CD19^+$, $CD8^+$, $CD3^+/CD69^+$, $CD3^+/CD49b^+$, $CD4^+/CD44^+$, $CD3^+$, $CD4^+$, $CD4^+/CD25^+$ and $CD3^+/CD8^+$ cells in draining lymph node were significantly increased compared with control. The absolute number of $CD3^+$, $CD4^+$, $CD4^+/CD25^+$ and $CD11b^+/Gr-1^+$ cells in paw joint were significantly decreased compared with control. The absolute number of $B220^+/CD23^+$ and $MHCII^+/CD11c^+$ cell in draining lymph node were significantly decreased compared with control. The levels of IgG was decreased and The levels of IgM was significantly decreased compared with control. Anti-collagen II in serum was significantly decreased compared with control. With the hematoxylin and eosin stain, the cartilage destruction and synovial cell proliferation were decreased compared with control. With the Masson's trichrome stain, the expression of collagen fibers was decreased compared with control. Results showed that GJB-6 had immunomodulatory effects. So we expect that GJB-6 should be used as a effective drugs for not only rheumatoid arthritis but also another auto-immune disease.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.4
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• pp.589-594
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• 2011

Smart Home or Home Network technology is one that continuously creates added value, making a better life. This paper designed and developed a smart home control system using smart phone. This proposed smart home system consists of home server control system, remote smart application system and home node structure. Home node structure, in detail, is composed of intrusion detection, gas leakage or gas valve control, door lock, automatic curtain, ventilation control and On/Off control modules and these modules are controlled at home server. Home server makes it easy to control home automatic control system anytime, anywhere as it provides remote interface that enables control via smartphone and user interface in itself.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.1
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• pp.81-88
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• 2009

This paper alined at the development of a lateral drift control method that is able to quantitatively control the lateral drift of global node. For this, we applied an efficient partial reanalysis algorithm. By using this algorithm, we could recalculate the displacement and member force of the specific node without reanalyzing the entire structure when member stiffness changes partially. The theoretical concepts of the algorithm are so simple that it is not necessary to solve the complicate differential equation or to repeat the analysis of entire structure. The proposed method calculates the drift contribution of each member for the global displacement according to the variation of section sizes by using the algorithm. Then by changing the member sizes as the order of drift contribution, we could control the lateral drift of global node with a minimum quantity of materials. 20 story braced frame structure system is presented to illustrate the usefulness of proposed method. It is shown that the proposed method is very effective in lateral drift control and the results obtained by proposed method are consistent with those of commercial analysis program.