• Journal of the Korean Society of Safety
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• v.11 no.3
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• pp.44-52
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• 1996

An experimental study on the effects of temperature change on the impact damages of CFRP aminates was made through an observation of the interrelations between the Impact energy vs. delamination area, the impact energy vs. residual bending strength, and the delamination area vs. the decreasing of the residual bending strength for CF/EPOXY and CF/PEEK composite laminates subjected to FOD (Foreign Object Damage) under high temperatures.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.10a
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• pp.254.2-254
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• 1999

• Bulletin of the Korean Space Science Society
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• 2006.04a
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• pp.87-87
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• 2006

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.295-298
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• 2003

IP 단편화는 서로 다른 네트워크 환경에서 IP 패킷의 효율적인 전송을 보장해 주고 있다. 하지만 시스템이 비정상적인 IP 단편을 적절히 재조합하지 못함으로써 시스템에 심각한 문제를 일으킬 수 있다. 그래서 본 논문에서는 네트워크 상에서 IP 단편화 공격을 탐지할 수 있는 방법을 제안한다. 제안한 방법은 IP 단편화 총격에 대해서 TCP 패킷을 NIDS가 미리 재조합을 함으로써 IP 단편화 공격에 대해 효율적인 탐지가 가능하다

• Clinics in Shoulder and Elbow
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• v.15 no.1
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• pp.37-42
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• 2012

Purpose: To consider the proper management of proximal humerus fracture on gunshot wounds. Materials and Methods: A 28-year-old male patient, who sustained a gunshot injury on the left arm 5 days ago, was admitted through the emergency department. Although he underwent an emergency surgery (bullet fragment removal and debridement), there remained bullet fragments around the proximal humerus fracture site. The wound seemed to be infected and a partial dehiscence occurred. No neurologic deficit was noted. Immediate exploration and debridement were performed, and an external fixator was applied to restore the anatomical alignment and manage the wounds. Intravenous antibiotics were administered. On the 9th postoperative day, wound debridement was done again, and cement beads mixed with antibiotics were inserted. After two weeks, the external fixator was removed, and the pin sites were closed after debridement. One week later, the open reduction and internal fixation with locking compression plate and screws were done. Result: At 3 months after the internal fixation, the bone union was obtained with satisfactory alignment of the humerus. Conclusion: The severity of the soft tissue injury influences the fracture management plan. Further, the risk on lead toxicity should be considered.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.1
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• pp.19-26
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• 2003

Recently, the number of internet service companies is increasing and so is the number of malicious attackers. Damage such as distrust about credit and instability of the service by these attacks may influence us fatally as it makes companies image failing down. One of the frequent and fatal attacks is DoS(Denial-of-Service). Because the attacker performs IP spoofing for hiding his location in DoS attack it is hard to get an exact location of the attacker from source IP address only. and even if the system recovers from the attack successfully, if attack origin has not been identified, we have to consider the possibility that there may be another attack again in near future by the same attacker. This study suggests to find the attack origin through MAC address marking of the attack origin. It is based on an IP trace algorithm, called Marking Algorithm. It modifies the Martins Algorithm so that we can convey the MAC address of the intervening routers, and as a result it can trace the exact IP address of the original attacker. To improve the detection time, our algorithm also contains a technique to improve the packet arrival rate. By adjusting marking probability according to the distance from the packet origin we were able to decrease the number of needed packets to traceback the IP address.

• Journal of Internet Computing and Services
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• v.6 no.1
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• pp.1-12
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• 2005

Recently, the patterns of cyber attack through internet have been various and have become more complicated and thus it is difficult to detect a network intruder effectively and to response the intrusion quickly. Therefore, It is almost not possible to chase the real location of a network intruder and to isolate the Intruder from network in UDP based DoS or DDoS attacks spoofing source IP address and in TCP based detour connection attacks. In this paper, we propose active security architecture on active network to correspond to various cyber attacks promptly. Security management framework is designed using active technology, and security control mechanism to chase and isolate a network intruder is implemented. We also test the operation of the active security mechanism implemented on test_bed according to several attack scenarios and analyze the experiment results.

• Journal of the Korea Computer Graphics Society
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• v.15 no.2
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• pp.9-17
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• 2009

Animating multiple characters to compete with each other is an important problem in computer games and animation films. However, it remains difficult to simulate strategic competition among characters because of its inherent complex decision process that should be able to cope with often unpredictable behavior of opponents. We adopt a reinforcement learning method in Markov games to action models built from captured motion data. This enables two characters to perform globally optimal counter-strategies with respect to each other. We also extend this method to simulate competition between two teams, each of which can consist of an arbitrary number of characters. We demonstrate the usefulness of our approach through various competitive scenarios, including playing-tag, keeping-distance, and shooting.

• Journal of KIISE:Information Networking
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• v.30 no.1
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• pp.30-37
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• 2003

In this paper, a discrete wavelet transform (DWT)-based watermarking system is proposed. The main feature of proposed system is that the embedding system uses adaptive thresholds to control the trade-off between the qualify of the watermarked image and the capacity of the watermark, and the trade-off between the quality and robustness of the watermarked image. Also, the extracting system rebuilds threshold according to various attacks and decides a watermark bit from the least distorted coefficient after measuring the distortion of coefficient. Finally, a new measure to detect the uniqueness of watermark is proposed. The experimental result shows that the proposed watermarking system is robust against conventional signal processing and intentional attacks.

• Journal of Chest Surgery
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• v.34 no.11
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• pp.879-882
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• 2001

advancement in the treatment of esophageal perforation due to the development of ICU care and antibiotics. There were controversies in the treatment of esophageal perforation when diagnosed after 24hrs. From 1995 to 2000, we performed a buttressed primary repair and mediastinal drainage in 6 Boerhaave\`s syndrome patients among 13 esophageal perforation patients. Two patients died(33%). They died because of pneumonia, ARDS and sepsis on 38th, 39th post-operative day respectively. Two patients had leak at the site of repair which was treated completely with conservative treatment. We report on the result of a buttressed primary repair and mediastinal drainage for 6 Boerhavve\`s syndrome patients.