• Convergence Security Journal
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• v.14 no.7
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• pp.53-58
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• 2014

MANET can quickly build a network because it is configured with only the mobile node and it is very popular today due to its various application range. However, MANET should solve vulnerable security problem that dynamic topology, limited resources of each nodes, and wireless communication by the frequent movement of nodes have. In this paper, we propose a domain-based distributed cooperative intrusion detection techniques that can perform accurate intrusion detection by reducing overhead. In the proposed intrusion detection techniques, the local detection and global detection is performed after network is divided into certain size. The local detection performs on all the nodes to detect abnormal behavior of the nodes and the global detection performs signature-based attack detection on gateway node. Signature DB managed by the gateway node accomplishes periodic update by configuring neighboring gateway node and honeynet and maintains the reliability of nodes in the domain by the trust management module. The excellent performance is confirmed through comparative experiments of a multi-layer cluster technique and proposed technique in order to confirm intrusion detection performance of the proposed technique.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.8
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• pp.660-666
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• 2014

In this paper, we consider a classification criteria of sensor nodes based on equipment function, and propose a routing search algorithm between node when an IP-USN is applied inside a ship. whereas a tree-type routing algorithm is applied to the limited mobile enviroment, such as engine room or machine room, a mesh-type routing alogrithm is to free mobile enviroment, such as passager corridor liviing quarters or restanrats areas. For mesh-type routing, it is necessary to maintain a seamless route path between a sink node and sensor nodes for which we consider a novel message exchange periodically. We proposed a new message, RDES message, which is issued periodically to update the topology of sensor node and check a connectivity between nodes.

• Journal of IKEEE
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• v.23 no.4
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• pp.1302-1308
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• 2019

This paper presents an approach for classifying image made by acquired position data from a 2D Lidar sensor with a convolutional neural network (CNN). Lidar sensor has been widely used for unmanned devices owing to advantages in term of data accuracy, robustness against geometry distortion and light variations. A CNN algorithm consists of one or more convolutional and pooling layers and has shown a satisfactory performance for image classification. In this paper, different types of CNN architectures based on training methods, Gradient Descent(GD) and Levenberg-arquardt(LM), are implemented. The LM method has two types based on the frequency of approximating Hessian matrix, one of the factors to update training parameters. Simulation results of the LM algorithms show better classification performance of the image data than that of the GD algorithm. In addition, the LM algorithm with more frequent Hessian matrix approximation shows a smaller error than the other type of LM algorithm.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.1
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• pp.72-78
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• 2003

A new self-organizing neuro-fuzzy network based rate control algorithm for MPEG-4 video encoder is proposed in this paper. Contrary to the traditional methods that construct the rate-distorion (RD) model based on experimental equations, the proposed method effectively exploits the non-stationary property of the video date with neuro-fuzzy network that self-organizes the RD model online and adaptively updates the structure. The method needs not require off-line pre-training; hence it is geared toward real-time coding. The comparative results through the experiments suggest that our proposed rate control scheme encodes the video sequences with less frame skip, providing good temporal quality and higher PSNR, compared to VM18.0.

• Journal of Broadcast Engineering
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• v.17 no.6
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• pp.1014-1028
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• 2012

Recently, N-screen service and secondary device have gotten an attention from public. Also, we can experience N-screen service through various digital devices. N-screen means multimedia technology which can seamlessly consume multimedia content. Secondary device means auxiliary multimedia device which can consume content related to main content through adjunct connection to main device. Not only be electronic manufactures interested in N-screen technology and services but also digital devices applied for N-screen have been released. But it has limitation that user can only consume content to be purchased from content company server not device of user. This paper proposes the system that composes effective and various N-screen multimedia service through MPEG-4 LASeR (Lightweight Application Scene Representation) PMSI (Presentation and Modification of Structured Information) as international standard technology which can provide scene description including many instruction for dynamic update of scene.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.9
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• pp.724-733
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• 2017

Accidents caused by upset condition leads to fatal damage to both manned and unmanned aircraft. This paper deals with real-time detection of these aircraft upset situations to prevent further severe situations. Firstly, the difference between sensor measurement and predicted measurement from Extended Kalman filter is monitored to determine whether a target aircraft goes into an upset condition or not. In addition, repeating the time update stage of the Extended Kalman filter for a specific length of time can enable future upset situation prediction. The results of aforementioned both the approaches will build a bridge to upset prevention for future generation of manned/unmanned aircraft.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.49-55
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• 2012

A study on e-book viewer terminal in the native language of the platform-dependent studies are based, This is inefficient in memory usage and screen rendering speed, and there are frequent system updates, e-book viewer, the nature of mobile terminal platform application compatibility issues may occur. In this paper, using the mobile app framework in order to design e-book e-book viewer, analyzed the structure of ePub file parser and file more structured modules were designed and MVC. Designed and implemented to test the functionality of the memory information that is currently running to provide the ability to show the relationship of DDMS and layout components were used to show Hierarchy Viewer. As a result, rendering the screen 150%, 84% in the heap memory usage, improved performance was confirmed.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.41-47
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• 2011

This paper is concerned with the DW-MCMA(Dual Weight vector Modified Constant Modulus Algorithm) adaptive equalization algorithm using the dual weight vector in order to improve the convergence characteristic and residual inter-symbol interference which are used as the performance index for an adaptive equalizer. The equalizer is used to reduce the distortion caused by the inter-symbol interference on the wireless and the wired band-limited channel that connect the transmitting system and receiving system. The CMA is widely known as the representative algorithm for equalization. In order to transmitting the mass information with a high speed through the channels, a fast convergence speed in the equalizer performance that is able to minimize overhead needed for equalization is acquired. In this paper, By the computer simulation, we confirmed that the proposed DW-MCMA has the faster convergence speed and the smaller residual inter-symbol interference than the conventional CMA and MCMA.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.3
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• pp.42-50
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• 2008

We developed a visual inspection system for detecting defective products. Most existing inspection systems are designed to be dedicated to one product, which makes operator spend extra money and time to adopt other products. In this work, we propose a flexible visual inspection system that can inspect various products without any additional major job at a low-cost. The developed system contained image processing algorithm libraries and user-friendly graphic interface for adaptable image-based inspection system. We can find a proper threshold value using the proposed algorithm which uses correlation coefficient between a non-defective product and existing sample images of defective product. And We tested the performance of the proposed algorithm using Otsu's method. The proposed system is applied to a automated inspection line for cellular phone.

• Journal of the Korean Institute of Gas
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• v.19 no.1
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• pp.38-44
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• 2015

FDS (Fire Dynamics Simulator) is the most widely used computational fluid dynamics software in the fire safety engineering community, and it is applicable to various evaluations of fire growth and its effects. This study made use of a range of outputs from FDS simulation to predict FED (Fractional Effective Concentration) and FEC (Fractional Effective Concentration) levels which are often adopted to evaluate toxicity of fire smoke. As it is not possible to calculate these values directly from outputs of FDS, it was necessary to produce them by means of additional calculation procedures incorporating results of evacuation simulation. In this study, the latest version of FDS, which was recently updated in November 2013, was utilized for the purpose of quantitative comparison with the old version of FDS. As a result, it was found that they make about 10 percent difference on average in predicting FED and FEC levels for the cable fire case study.