• Journal of Industrial Convergence
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• v.22 no.4
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• pp.21-29
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• 2024

This study analyzed the difficulty of scoring in different match situations in relation to which competitor scored first. The study analyzed the data from the 2022 Guadalajara World Taekwondo Championships. The analysis was performed for two separate weight classes: lightweight and heavyweight. Four game content variables were used: whether the athlete scored first, attack type, attack area, and game situation. Descriptive statistics, the Rasch model, and discrimination function questions were applied for data processing. SPSS and Winsteps were used for the statistical analysis, and the statistical significance level was set at 0.05. Consequently, in the lightweight class, the scoring frequency of the first scorer was high for all the game variables. In the heavyweight class, the scoring frequency for the first scorer was high for the attack type and attack area. By contrast, those who did not score first were more frequently found to be in a loss situation. By analyzing the scoring difficulties in different match situations based on whether the competitor scored first, the athletes who scored first in attack type most easily scored first. In losing situations, the athletes who scored first in attack area scored most easily, whereas those who did not score first scored most easily in body and match situations. For the heavyweight class, those who scored first in terms of attack type, counter-attack, and attack area scored the most easily while winning in body and match situations.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.28 no.2
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• pp.12-17
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• 2020

Even though the benefit of flight at high angle-of-attack is to be able to reduce the speed of flight and maneuvers in complex flight environment, the flight at high angle-of-attack, however, is easy to be in stall which is characterized by sever unsteady flow separation over an airfoil. Current unsteady numerical analysis using DES was conducted to predict the aerodynamic characteristics of a NACA 0021 airfoil at high angle-of-attack conditions. And this provides the comparison with the steady numerical one with the typical turbulence models. The unsteady calculation by DES is appropriate in terms of predicting the aerodynamic performance of NACA 0021 airfoil at high angle-of-attack conditions.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.209-212
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• 2006

Until now, sulfate attack is not completely understood. The purpose of this study is to provide a fundamental data to understand deterioration mechanism by sulfate attack. Chemical processes for products formed by sulfate attack were explained in this study. ASTM C1012 test and microstructural observations such as XRD and BSE analysis were carried out to manifest behavior and role of the products formed during sulfate attack. Regarding the dominant causes of sulfate attack, the main deterioration modes could be divided into 3 types; (1) expansive type, (2) onion-peeling type, and (3) acidic type.

• Journal of Convergence Society for SMB
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• v.5 no.1
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• pp.19-23
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• 2015

Distributed Denial of Service attack is a form of denial of service attacks, the attacker to attack a place in a number of points of attack by a wide variety of forms over the network to perform a service on a point attack . Do not use a specific server or client attempts to make a connection to many services available that prevents this attack and so normally used . Corresponding methods of DDoS attacks has a corresponding managerial aspects and technical aspects of the proposed two.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.1
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• pp.17-26
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• 2020

As more users use mobile devices, shoulder surfing attacks have emerged as an important issue in security. According to research report, in fact, the result showed that about 30% of smartphone users are hit by shoulder surfing attacks. To this end, in this paper, we consider a shoulder surfing attack and propose a partially hidden password system to resistant to its attack. In order to help readers understand, we describe the proposed password system in more detail using one simple example. The core idea behind the proposed system is to place the user's password randomly in the specified grid instead of entering a password directly. As a result, even if an attacker makes a shoulder surfing attack to observe the password, the user can hide the preset password and defend against the attack. We also show how the security of the password system proposed in this paper is improved. In addition, even if there are consecutive shoulder surfing attacks, the security of the proposed password system is robust.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.1
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• pp.103-113
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• 2017

Cyber attacks can be classified by type of cyber war, terrorism and crime etc., depending on the purpose and intent. Those are mobilized the various means and tactics which are like hacking, DDoS, propaganda. The damage caused by cyber attacks can be calculated by a variety of categories. We may identify cyber attackers to pursue trace-back based facts including digital forensics etc. However, recent cyber attacks are trying to induce confusion and deception through the manipulation of digital information or even conceal the attack. Therefore, we need to do the harm-based analysis. In this paper, we analyze the damage caused during cyber attacks from economic and political point of view and by inferring the attack intent could classify types of cyber attacks.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.5
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• pp.1169-1178
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• 2012

Recently, since the most software intensive systems are using internet environment for data exchange, the software security is being treated as a big issue. And, to minimize vulnerability of software system, security ensuring steps which are applying secure coding rules, are introduced in the software development process. But, since actual attacks are using a variety of software vulnerabilities, it is hard to analyze software weakness by monotonic analysis. In this paper, it is tried to against the complex attack on the variety of software vulnerability using the coupling which is one of the important characteristic of software. Furthermore, pre-analysis of the complex attack patterns using a combination of various attack methods, is carried out to predict possible attack patterns in the relationship between software modules. And the complex attack pattern analysis method is proposed based on this result.

• Journal of the Korea Society of Computer and Information
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• v.26 no.9
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• pp.81-88
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• 2021

In this paper, we analyze the possibility of deregistration attack in 5G SNPN (Standalone Non-Public Network) based on 3GPP standard document. In the deregistraion attack, the attacker pretends to be a UE that is normally registered with AMF (Access and Mobility Management Function) and attempts to establish a spoofed RRC (Radio Resource Control) connection, causing AMF to deregister the existing UE. The existing deregistration attack attempts a spoofed RRC connection to the AMF in which the UE is registered. In addition, this paper analyzes whether deregistration attack is possible even when an attacker attempts to establish a spoofed RRC connection to a new AMF that is different from the registered AMF. When the 5G mobile communication network system is implemented by faithfully complying with the 3GPP standard, it is determined that a deregistration attack of a UE is impossible.

• Journal of the Korea Society of Computer and Information
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• v.28 no.5
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• pp.67-74
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• 2023

In this paper, we analyze the authentication protocol for DRM proposed by Hussain et al. in 2022, and present an improved solution. Hussain et al. argued that their authentication protocol guarantees man-in-the-middle attack, replay attacks, and mutual authentication. However, as a result of analyzing Hussain et al.'s authentication protocol in this paper, Hussain et al.'s authentication protocol still has an insider attack problem, a problem with Yu et al.'s authentication protocol that they pointed out. For this reason, when an inside attacker acquires information on a mobile device, a user impersonation attack was also possible. In addition, there were problems with the user's lack of ID format verification and the problem of the secret key mismatch of the digital contents between the server and the user. Therefore, this paper proposes an improved solution to solve these problems. As a result of analysis in this paper, the improved solution is safe from various attacks such as smart card attack, insider attack, and password guessing attack and can safely authenticate users of DRM.

• Journal of the Korea Society of Computer and Information
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• v.25 no.3
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• pp.65-72
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• 2020

With the development of information technology and the growth of the scale of system and network, cyber threats and crimes continue to increase. To cope with these threats, cybersecurity training based on actual attacks and defenses is required. However, cybersecurity training requires expert analysis and attack performance, which is inefficient in terms of cost and time. In this paper, we propose a cyber attack simulator that automatically executes attack techniques. This simulator generates attack scenarios by combining attack techniques modeled to be implemented and executes the attack by sequentially executing the derived scenarios. In order to verify the effectiveness of the proposed attack simulator, we experimented by setting an example attack goal and scenarios in a real environment. The attack simulator successfully performed five attack techniques to gain administrator privileges.