• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.413-416
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• 2008

Reinforcement corrosion is generally prohibited under normal condition by the alkalinity of the pore water in the concrete. However, concrete structures in marine environment are subjected to chloride attack due to the high salinity of the sea water. Thus the probability of steel corrosion becomes higher when the chloride ions are introduced into the concrete. Steel corrosion is a decisive factor for the determination of service life of the marine concrete structure because chloride ions are abundant in the sea, and piers are the typical construction elements in concrete structures in marine environment. Hence, it is of great importance to evaluate the service life of the piers. In this paper, chloride penetration analysis for the rectangular pier in the marine environment is performed considering the diffusion and convection movement of chlorides. Result reveals that the service life of the reinforcement with drying-wetting cycles is much shorter than that of the reinforcement with saturated condition. This may be due to the fact that moisture movement is much faster that chloride diffusion.

• The KIPS Transactions:PartC
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• v.9C no.3
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• pp.359-366
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• 2002

Nowadays, the hacking techniques are developed increasingly with wide use of internet. The recent type of scanning attack is appeared in against with multiple target systems on the large scaled domain rather than single network of an organization. The development of scan detection management system which can detect and analyze scan activities is necessary to prevent effectively those attacking at the central system. The scan detection management system is useful for effective utilization of various detection information that received from scan detection agents. Real time scan detection management system that can do the integrated analysis of high lever more that having suitable construction in environment of large scale network is developed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11B
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• pp.689-697
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• 2005

The IETF has created the v6ops Working Group to assist IPv6 transition and propose technical solutions to achieve it. But it's quite problem which security consideration for a stage of IPv4/IPv6 transition and co-existence. There are new security problem threat that it caused by the characteristics of heterogeneity. In this paper, we describe IPv6 transition mechanisms and analyze security problem for IPv6 transition mechanism. also we propose security consideration and new security mechanism. We analyzed DoS and DRDoS in 6to4 environment and presented a address sanity check as a solution. We also showed an attack of address exhaustion in address allocation server. To solve this problem, we proposed challenge-response mechanism in DSTM.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4B
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• pp.435-441
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• 2009

The one-time password system solves the problem concerning password reuse caused by the repeated utilization of an identical password. The password reuse problem occurs due to the cyclic repetition at the time of password creation, and authentication failure can occur due to time deviation or non-synchronization of the number of authentication. In this study, the password is created asynchronously and exchanged with the user, who then signs using a digital signature in exchange for the password and a valid verification is requested along with the certificate to ensure non-repudiation. Besides this, a verification system for one-time password is proposed and designed to improve security by utilizing the validity verification that is divided into certificate verification and password verification. Comparative analysis shows that the mechanism proposed in this study is better than the existing methods in terms of replay attack, non-repudiation and synchronization failure.

• Convergence Security Journal
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• v.11 no.6
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• pp.9-15
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• 2011

It is difficult to identify attack requests from normal ones when those attacks are based on CSRF which enables an attacker transmit fabricated requests of a trusted user to the website. For the protection against the CSRF, there have been a lot of research efforts including secret token, custom header, proxy, policy model, CAPTCHA, and user reauthentication. There remains, however, incapacitating means and CAPTCHA and user reauthentication incur user inconvenience. In this paper, we propose a method to detect CSRF attacks by analyzing the structure of websites and the usage patterns. Potential victim candidates are selected and website usage patterns according to the structure and usage logs are analyzed. CSRF attacks can be detected by identifying normal usage patterns. Also, the proposed method does not damage users' convenience not like CAPTCHA by requiring user intervention only in case of detecting abnormal requests.

• Journal of the Korea Convergence Society
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• v.9 no.7
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• pp.55-62
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• 2018

Recently, as the threat of cyber crime increases, the importance of security control to cope with cyber attacks on the information systems in the first place such as real-time detection is increasing. In the name of security control center, cyber terror response center and infringement response center, institutional control personnel are making efforts to prevent cyber attacks. Especially, we are detecting infringement accident by using network security equipment or utilizing control system, but it's not enough to prevent infringement accident by just controlling based on device-driven simple patterns. Therefore, the security control system is continuously being upgraded, and the development and research on the detection method are being actively carried out by the prevention activity against the threat of infringement. In this paper, we have defined the method of detecting infringement of major component module in order to improve the problem of existing infringement detection method. Through the performance tests for each module, we propose measures for effective security control and study effective infringement threat detection method by upgrading the control system using Security Information Event Management (SIEM).

• Clinical and Experimental Pediatrics
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• v.59 no.2
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• pp.74-79
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• 2016

Purpose: Febrile seizure, the most common type of pediatric convulsive disorder, is a benign seizure syndrome distinct from epilepsy. However, as epilepsy is also common during childhood, we aimed to identify the prognostic factors that can predict epilepsy in children with febrile seizures. Methods: The study comprised 249 children at the Korea University Ansan Hospital who presented with febrile seizures. The relationship between the subsequent occurrence of epilepsy and clinical factors including seizure and fever-related variables were analyzed by multivariate analysis. Results: Twenty-five patients (10.0%) had additional afebrile seizures later and were diagnosed with epilepsy. The subsequent occurrence of epilepsy in patients with a history of febrile seizures was associated with a seizure frequency of more than 10 times during the first 2 years after seizure onset (P<0.001). Factors that were associated with subsequent occurrence of epilepsy were developmental delay (P<0.001), preterm birth (P =0.001), multiple seizures during a febrile seizure attack (P =0.005), and epileptiform discharges on electroencephalography (EEG) (P =0.008). Other factors such as the age at onset of first seizure, seizure duration, and family history of epilepsy were not associated with subsequent occurrence of epilepsy in this study. Conclusion: Febrile seizures are common and mostly benign. However, careful observation is needed, particularly for prediction of subsequent epileptic episodes in patients with frequent febrile seizures with known risk factors, such as developmental delay, history of preterm birth, several attacks during a febrile episode, and epileptiform discharges on EEG.

• Korean Journal of Adult Nursing
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• v.19 no.2
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• pp.167-177
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• 2007

Purpose: This cross-sectional survey research was undertaken to identify the factors influencing time from onset to hospital arrival of stroke patients and to provide basic information for the development of intervention programs for stroke patients. Methods: The data were collected using a convenient sampling method from three hospitals in Inchon. The subjects were 78 patients who were diagnosed as stroke by doctor and they voluntarily participated in the study. Results: On the average, subjects arrived at the hospitals by 16.72 hours after the onset of stroke events with the range from 0.17 hours to 72 hours. Thirty-four(43.6%) subjects arrived within 3 hours which can maximize treatment effects. There was significant difference in hospital presentation time according to the level of knowledge(${\chi}^2=18.629$, p=.0003). A negative correlation was found between the hospital presentation time and self-efficacy (r= -.320, p=.004). Stepwise multiple regression analysis revealed that the most powerful predictor was self-efficacy. Self-efficacy, the level of knowledge and physical symptoms were significant factors and accounted for 21.7% of the variance of hospital presentation time in stroke patients. Conclusion: According to the results, self-efficacy is a useful concept for reducing the hospital presentation time from onset of attack in stroke patients. Therefore, nurses should consider educational programs which include not only a knowledge of stroke and recurrence prevention but also the concept of self-efficacy.

• Journal of the Korea Society of Computer and Information
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• v.16 no.1
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• pp.125-132
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• 2011

A hierarchical Web Security System, which is a solution to various web-based attacks, seemingly is not able to keep up with the improvement of detoured or compound attacks. In this paper, we suggest an efficient detecting scheme for web-based attacks like Malware, XSS, Creating Webshell, URL Spoofing, and Exposing Private Information through monitoring HTTP outbound traffics in real time. Our proposed scheme detects web-based attacks by comparing the outbound traffics with the signatures of HTML tag or Javascript created by the attacks. Through the verification analysis under the real-attacked environment, we show that our scheme installed in a hierarchical web security system has superior detection capability for detoured web-based attacks.

• Journal of the Korea Society of Computer and Information
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• v.19 no.1
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• pp.85-94
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• 2014

This paper studied the detection technique using file DNA-based behavior pattern analysis in order to minimize damage to user system by malicious programs before signature or security patch is released. The file DNA-based detection technique was applied to defend against zero day attack and to minimize false detection, by remedying weaknesses of the conventional network-based packet detection technique and process-based detection technique. For the file DNA-based detection technique, abnormal behaviors of malware were splitted into network-related behaviors and process-related behaviors. This technique was employed to check and block crucial behaviors of process and network behaviors operating in user system, according to the fixed conditions, to analyze the similarity of behavior patterns of malware, based on the file DNA which process behaviors and network behaviors are mixed, and to deal with it rapidly through hazard warning and cut-off.