• KIPS Transactions on Computer and Communication Systems
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• v.2 no.9
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• pp.393-398
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• 2013

This paper introduces a new collision attack on first-order masked AES. This attack is a known plaintext attack, while the existing collision attacks are a chosen plaintext attack. In addition, our method is more efficient than the second-order power analysis and requires about 1/27.5 power measurements by comparison with the last collision attack. Some experiment results of this paper support this fact. In this paper, we also introduce a simple countermeasure, which can protect against our attack.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.7
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• pp.1111-1119
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• 2022

Tourism projects through islands in the waters of Sinan-gun became active, and as a result, a total of 13 marine bridges connecting islands were completed. However, the marine bridge constructed in the fairway is dangerous for traffic. Particularly, in the case of the marine bridge connecting two islands, the width of the fairway is extremely narrow, therefore the risk is higher. In this study, we evaluated the risk of collision between marine bridge piers and ships using the IALA Waterway Risk Assessment Program (IWRAP), a risk assessment model for port waterways, based on a maritime traffic survey on the coastal bridge in Sinan-gun. The results, indicated that No.1 Sinan bridge had the highest probability of collision and most of the transit ships were coastal passenger ships. In addition, No.1 Sinan bridge was the place where the most collision accidents occurred among the marine bridge piers in the target sea, and the cause this study was analyzed. An analysis of the satellite images of the sea environment of No.1 Sinan bridge using an image processing method, confirmed that obstacles that could not be seen in the chart existed nearby the bridge. As a result, traffic was observed to be concentrated in one direction, unlike two-way traffic, which is a method of inducing traffic of bridges to avoid obstacles. The risk cause analysis method using the image processing technique of this study is expected to be used as a basic research method for analyzing the risk factors of island bridge in the future.

• Journal of Digital Contents Society
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• v.11 no.2
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• pp.243-251
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• 2010

In this paper, 2 devices through the input image are projected onto the output video device to extract 3D information of real objects and they are located in virtual space. All 3D objects for each inter-object interaction information and location information makes the validation process by recognizing conflict. The proposed extract 3D information of real objects and collision handling inter-object interaction in the most basic issues in augmented reality, because more than anything is a matter to be prescriptive. Therefore, the proposed system to solve this problem exists in virtual space, all objects of the user by validating the conflict between realism and immersion to show that aims to increase.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.12
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• pp.52-59
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• 2004

This paper shows about the machine simulation embodiment when it happens NC equipment and between workpiece and interference in 5 axises machining of aluminium alloy a vehicles parts. And this research has been chosen because of the highest equipment interference occurrence rate at a vehicles parts processing of 5 axises horizontal machine. It can verify simulation and machining process through correlation of their dynamic relations, interference, collision as embodied virtual manufacturing system of machine, workpiece, and holder etc. That is necessary element in shape of machine tool, function and processing in imagination ball. Also, it verifies about interference and collision between NC equipment and workpiece, as it applied machine simulation to NC Data of actuality aircraft parts of BULKHEAD and FRAME. As the result of this study, by removing the equipment interference and collision element which creates NC data, the virtual machine tool it the efficiency of machine process has increased.

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.1
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• pp.6-12
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• 2004

Identification rate and time are very important in the identification of RFID tag, and the tag requires simple structure to use economically large quantity of tags. These factors make the MAC protocols of wired or wireless network environment result in different requirements. In the paper, we propose a method to apply spread spectrum scheme using orthogonal channel via Walsh function as the anti-collision communication system for the purpose of non-collision identification of multiple tags, and consider its property. The proposed system use two step identification. in the first step, collision is resolved via constructing to respond after specific delay time based on unique n, and conventional polling scheme follows in the second step.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.115-121
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• 2012

In spite of serious injuries caused by traffic accidents of car-pedestrian, the dispute is constantly occurring and economic losses and mental suffering is escalating since the cause of accidents is not scientifically identified. This study reviewed vehicle dynamics, driving dynamics, collision dynamics, traffic and road engineering for traffic accidents analysis based on traffic accidents related physically objective evidence and analysed the cause of accidents by getting results which applied vehicle initial collision velocity before collision, processing trajectory, collision stance, vehicle velocity before & after collision and parameter by using PC-Crash program. I found that skid mark and collision velocity of car-pedestrian had the error of 11.2%, 2,27% compared to theoretical values.

• Journal of Aerospace System Engineering
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• v.15 no.1
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• pp.102-110
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• 2021

Recently, multi-copters equipped with various collision avoidance sensors have been introduced to improve flight stability. LiDAR is used to recognize a three-dimensional position. Multiple cameras and real-time SLAM technology are also used to calculate the relative position to obstacles. A three-dimensional depth sensor with a small process and camera is also used. In this study, a small collision-avoidance multi-copter system capable of in-door flight was developed as a platform for the development of collision avoidance software technology. The multi-copter system was equipped with LiDAR, 3D depth sensor, and small image processing board. Object recognition and collision avoidance functions based on the YOLO algorithm were verified through flight tests. This paper deals with recent trends in drone collision avoidance technology, system design/manufacturing process, and flight test results.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.248-249
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• 2013

This study presents a potential field method for path planning to goal with a mobile robot in unknown environment. The proposed algorithm allows mobile robot to navigate through static obstacles, and find the path in order to reach the target without collision. This algorithm provides the robot with the possibility to move from the initial position to the final position (target). Stage and Player simulator is used to perform the robot motion and implement the potential field algorithm in C/C++ for performance evaluation. Two-dimensional terrain model is used to simulate the ability of robot in motion planning without any collision.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.97-100
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• 2011

Underwater Wireless Acoustic Sensor Networks have become an important area of research over the recent decades. Designing an underwater network, especially a media access control (MAC) protocol, faces many challenges due to the peculiarities of underwater environment. One of the most important problems is resulted from long and variable propagation delay of the acoustic wave. In this paper, we propose a new method, namely Dynamic Timeout over Multiple Access with Collision Avoidance (DT/MACA), which is designed to handle long and high variable propagation delay in underwater acoustic sensor networks. In this proposed method, the difference timeout intervals are evaluated and applied to each network transmission. Simulation results show that our work not only improves the network throughput, but also decreases the unnecessary retransmission and end-to-end delay.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.820-825
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• 2008

In the article 16 of the domestic rolling stock crashworthiness regulations, the collision acceleration level during collision accidents should remain under the maximum 7.5g and the average 5g. By the way, the accelerations obtained in crash simulations and tests contain many kinds of high frequency components due to numerical oscillations or noisy signals. So, this paper aims to develop reliable post-processing methods to filter high frequency oscillations and extract the rigid body motions of passenger rail cars. For this study we used the 1-dimensional dynamic model of KHST (Korean high-speed train), and evaluated acceleration data at the driver's area in the first power car and the passenger area in the following trailer.