• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.9
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• pp.1374-1381
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• 2022

Existing research on security technology related to network attack response has focused on research using hardware network security technology, network attacks that wiretap and wiretap network packets, denial of service attack that consumes server resources to bring down the system, and network by identifying vulnerabilities before attack. It is classified as a scanning attack. In addition, methods for increasing network security, antivirus vaccines and antivirus systems have been mainly proposed and designed. In particular, many users do not fully utilize the security function of the router. In order to overcome this problem, it is classified according to the network security level to block external attacks through layered security management through layer-by-layer experiments. The scope of the study was presented by examining the security technology trends of edge routers, and suggested methods and implementation examples to protect from threats related to edge router-based network attacks.

• Journal of information and communication convergence engineering
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• v.20 no.3
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• pp.166-173
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• 2022

Recently, studies have been conducted on intelligent transportation systems (ITS) that provide safety and convenience to humans. Systems that compose the ITS adopt architectures that applied the cloud computing which consists of a high-performance general-purpose processor or graphics processing unit. However, an architecture that only used the cloud computing requires a high network bandwidth and consumes much power. Therefore, applying edge computing to ITS is essential for solving these problems. In this paper, we propose an edge artificial intelligence (AI) device based ITS. Edge AI which is applicable to various systems in ITS has been applied to license plate recognition. We implemented edge AI on a field-programmable gate array (FPGA). The accuracy of the edge AI for license plate recognition was 0.94. Finally, we synthesized the edge AI logic with Magnachip/Hynix 180nm CMOS technology and the power consumption measured using the Synopsys's design compiler tool was 482.583mW.

• Journal of the Korea Society of Computer and Information
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• v.15 no.10
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• pp.35-47
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• 2010

To complement inaccurate edge information and detect correctly the boundary of a vehicle in an image, an extended edge analysis technique is presented in this paper. The vehicle is detected using the bottom boundary generated by a vehicle and the road surface and the left and right side boundaries of the vehicle. The proposed extended edge analysis method extracts the horizontal edge by merging or dividing the nearby edges inside the region of interest set beforehand because various noises deteriorates the horizontal edge which can be a bottom boundary. The horizontal edge is considered as the bottom boundary and the vertical edges as the side boundaries of a vehicle if the extracted horizontal edge intersects with two vertical edges which satisfy the vehicle width condition at the height of the horizontal edge. This proposed algorithm is more efficient than the other existing methods when the road surface is complex. It is proved by the experiments executed on the roads having various backgrounds.

• Journal of Broadcast Engineering
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• v.18 no.4
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• pp.619-630
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• 2013

In this paper, we propose an edge directed color demosaicing algorithm considering color channel correlation. The proposed method consists of local region classification step and edge directional interpolation step. In the first step, each region of a given Bayer image is classified as normal edge, pattern edge, and flat regions by using intra channel and inter channel gradients. Especially, two criteria and verification process for the normal edge and pattern edge classification are used to reduce edge direction estimation error, respectively. In the second step, edge directional interpolation process is performed according to characteristics of the classified regions. For horizontal and vertical directional interpolations, missing color components are obtained from interpolation equations based on intra channel and inter channel correlations in order to improve the performance of the directional interpolations. The simulation results show that the proposed algorithm outperforms conventional approaches in both objective and subjective terms.

• Journal of the Korea Society of Computer and Information
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• v.12 no.3
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• pp.105-113
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• 2007

In this paper, an image segmentation method which is based on edge salience map and region merging is presented. The edge salience map is calculated by combining a texture edge map with a color edge map. The texture edge map is computed over multiple spatial orientations and frequencies by using Gabor filter. A color edge is computed over the H component of the HSI color model. Then the Watershed transformation technique is applied to the edge salience map to and homogeneous regions where the dissimilarity of color and texture distribution is relatively low. The Watershed transformation tends to over-segment images. To merge the over-segmented regions, first of all, morphological operation is applied to the edge salience map to enhance a contrast of it and also to find mark regions. Then the region characteristics, a Gabor texture vector and a mean color, in the segmented regions is defined and regions that have the similar characteristics, are merged. Experimental results have demonstrated the superiority in segmentation results for various images.

• Korean Journal of Plant Resources
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• v.26 no.4
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• pp.516-518
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• 2013

A new leaf variegated cultvar 'White Edge' was developed by ethyle methane sulfonate(EMS) treatment on seed of Hosta minor. Among induced leaf variegated plant, some with white color on the edge of the leaves was selected. They were cultivated via vegetative propagation. 'White Edge' was finally selected through the test of characteristics from 2003 to 2005. Assessment of botanical characteristics was conducted for three years. The major characteristic of these cultivar is that they maintain uniformly all year round. 'White Edge'(Grant No.1880) was registered to the Korea Seed and Variety Service(KSVS) for commercialization in 2007. These cultivar are useful as materials for pot or as ground cover plants.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.12
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• pp.1688-1696
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• 2020

The paradigm of Internet-of-things(IoT) systems is changing from a cloud-based system to an edge-based system to solve delays caused by network congestion, server overload and security issues due to data transmission. However, edge-based IoT systems have fatal weaknesses such as lack of performance and flexibility due to various limitations. To improve performance, application-specific hardware can be implemented in the edge device, but performance cannot be improved except for specific applications due to a fixed function. This paper introduces a edge-centric metamorphic IoT(mIoT) platform that can use a variety of hardware through on-demand partial reconfiguration despite the limited hardware resources of the edge device, so we can increase the performance and flexibility of the edge device. According to the experimental results, the edge-centric mIoT platform that executes the reconfiguration algorithm at the edge was able to reduce the number of server accesses by up to 82.2% compared to previous studies in which the reconfiguration algorithm was executed on the server.

• Wind and Structures
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• v.33 no.6
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• pp.463-470
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• 2021

This study investigates the aerodynamic characteristics of NACA series airfoil by altering the trailing edge in the form of extended and serrated sections. This contemporary advent examined NACA 0020 airfoil experimentally at the angle of attack ranging from 0° to 45° and for the Reynolds number of 2.46 × 105. To figure out the flow behaviour, the standard average pressure distribution over the airfoil surface is estimated with 50 pressure taps. The time series surface pressure is recorded for 700 Hz of sampling frequency. The extended trailing edge of 0.1 c, 0.2 c and 0.3 c are attached to the base airfoil. Further, the triangular serration is introduced with the base length of 2 cm, 4 cm and 6 cm. Each base length with three different amplitudes of 0.1 c, 0.2 c and 0.3 c were designed and equipped with the baseline case at the trailing edge and tested. The aerodynamic force coefficient, as well as pressure coefficient are presented. The obtained data advises that modification in the trailing edge will reflect the aerodynamic characteristics and the flow behaviour over the section of a wing. Resultantly, the extended trailing edge as a thin elongated surface attached to a base airfoil without revising the main airfoil favors good lift increment. The serrated trailing edge acts as a flow control device by altering the flow pattern results to delay the stall phenomenon. Besides it, improves lift co-efficient with less amount of additional drag. This extended and serrated trailing edge approach can support for designing the future smart airfoil.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.4 s.74
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• pp.399-406
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• 2006

The natural frequencies of Al square plates with a brass inclusion were analyzed by the rule of mixtures. The rule of mixtures is the method to derive natural frequency mutiplying effective inplane wane speed and nondimensional frequency parameters. Numerical models were Al square plates with an inclusion with cantilever type, 2 clamped edge-2 free edge type, 3 clamped edge-1 free edge type and fully clamped edge type. In cantilever type plates, 2 clamped edge-2 free edge type plates and 3 clamped edge-1 free edge plates with an inclusion, good agreement within 10% obtained from rule of mixtures' results and numerical analysis results within inclusion area ratio 1/9. It was found that the natural frequencies of the cantilever type, 2 clamped edge-2 free edge type and 3 clamped edge-1 free edge type plates with an inclusion decrease as the size of inclusion increases when inclusion is located center of plates. And when the density of inclusion is less than the plates, natural frequency of plates with an inclusion increases as the size of inclusion increases.

• 한국연소학회:학술대회논문집
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• 2004.11a
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• pp.55-61
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• 2004

Leading front of a lifted diffusion flame in turbulent mixing layer was investigated in order to find a appropriate definition of the turbulent edge propagation speed. The turbulent lifted diffusion flame was simulated by employing the flame hole dynamics combined with level-set method which yields a temporally evolving turbulent extinction process. By tracing the leading front locations of the temporal flame edges, temporal variations of the liftoff height, local flow velocity, and edge propagation speed at the leading front were investigated and they demonstrated the flame-stabilization condition of the turbulent lifted flame. Finally, a turbulent edge propagation speed was defined and its temporal variation from the simulation was discussed.