• Geotechnical Engineering
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• v.14 no.2
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• pp.67-78
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• 1998

Microtunnelling is a technique applied to install a small-size tunnel in a soft cohesionless ground. In microtunnelling, a series of concrete tubular segments are pushed from a starting pit to power-line tunnel under a runway of JFK international airport at New York. During the microtunneling process, bentonite is jetted with very hyh pressure through a nozzle to advance disturbance in the subgrade caused by the pressurized bentonite in the aspects of subgrade stiffness. SASW measurements were performed on the runway above the center line of the shear wave velocity profiles. Besides the change of subgrade stiffness, the change of subgrade strength was also evaluated by the site-specific relationships between shear wave velocity and N value, which was determined by N values. The estimated N values gave a clue to the understanding of the change of subgrade strength.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.07a
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• pp.133-137
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• 2003

IPsec은 차세대 IP 프로토콜인 IPv6에서 필수 구현 사항이며, 네트워크 계층에 적용되어 보안 서비스를 제공하며, 모든 인터넷 서비스를 대상으로 일관된 보안 서비스 제공이 가능하다는 특징을 지닌 국제 표준 프로토콜이다 이러한 IPsec 시스템에서 키 분배 및 관리를 위해 사용되고 있는 IKE 프로토콜은 시스템의 복잡성 문제와 함께 DoS 공격에 취약하다는 문제점이 발견되어 이를 해결하고자 IPsec WG에서 개선 작업 중에 있다. 본 논문에서는 기존 IKE 프로토콜(IKEvl)의 문제점과 IPsec WG에서 개선 작업중인 IKEv2와 JFK 두가지 후보안의 분석된 내용을 정리하였으며, 분석 정리된 내용들이 기존 IKE 프로토콜에 적용시 보안기능 관점에서 고려해야할 사항들을 정리하였다.

• The KIPS Transactions:PartC
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• v.10C no.2
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• pp.133-140
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• 2003

IKE, which is the standard key management protocol for IPSEC, is said to have several known problems. To resolve the problems of the IKE, two protocol proposals are being discussed in the IETF. the IKE version 2 and Just Fast Keying protocols. They should satisfy several protocol design requirements such as the protocol simplicity, the endurability against DOS attacks, the degree of the PFS, the identity protection, the cryptographic negotiation, and the authentication methods. In this paper, we summarize the characteristics of these two protocols and try to analyze their implications according to the protocol design requirements.

• Animal cells and systems
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• v.16 no.3
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• pp.173-182
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• 2012

The p53 protein plays a pivotal role in tumor suppression. The cellular level of p53 is normally kept low by proteasome-mediated degradation, allowing cell cycle progression and cell proliferation. Under stress conditions, such as DNA damage, p53 is stabilized and activated through various post-translational modifications of itself as well as of its regulatory proteins for induction of the downstream genes responsible for cell cycle arrest, DNA repair, and apoptosis. Therefore, the level of p53 should be tightly regulated for normal cell growth and for prevention of the accumulation of mutations in DNA under stress conditions, which otherwise would lead to tumorigenesis. Since the discovery of Mdm2, a critical ubiquitin E3 ligase that destabilizes p53 in mammalian cells, nearly 20 different E3 ligases have been identified and shown to function in the control of stability, nuclear export, translocation to chromatin or nuclear foci, and oligomerization of p53. So far, a large number of excellent reviews have been published on the control of p53 function in various aspects. Therefore, this review will focus only on mammalian ubiquitin E3 ligases that mediate proteasome-dependent degradation of p53.

• Journal of Astronomy and Space Sciences
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• v.37 no.4
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• pp.249-255
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• 2020

We develop the tissue-equivalent proportional counter (TEPC) type's space radiation dosimeter to measure in-situ aviation radiation. That was originally developed as a payload of small satellite in the low-earth orbit. This dosimeter is based on a TEPC. It is made of an A-150 tissue-equivalent plastic shell of an internal diameter of 6 cm and a thickness of 0.3 cm. TEPC is filled with pure propane at 13.9 torrs to simulate a cell diameter of 2 ㎛. And the associated portable and low power electronics are also implemented. The verification experiments have been performed by the calibration experiments at ground level and compared with Liulin observation at aircraft altitude during the flight between Incheon airport (ICN) and John F. Kennedy airport (JFK). We found that the TEPC dosimeter can be used as a monitor for space radiation dosimeter at aviation altitude based on the verification with Liulin observation.

• The Korean Journal of Air & Space Law and Policy
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• v.23 no.2
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• pp.115-136
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• 2008

The development of the aviation technology is beyond the people's imagination. For example, with some exaggeration, If the autopilot engage upon take off, You will realize that you are on the centerline of the foggy JFK runway 13R after 15 hours with only once or twice of intervention. But the more aviation technology develops, the more responsible the pilot will be who has the final authority of the aviation safety. In the JAL 706 accident caused by unidentified reason, the pilot increased pitch abruptly and overrode the control from the autopilot. The result of this process made the death of a flight attendant and some injuries of a few passengers. The district court found the pilot not guilty at the first trial on the ground that the control override was not connected to the possibility of foresight and avoidance of the human death. The pilot was proved to be innocent through the analysis of the DFDR and ADAS that the override did not precede the unidentified pitch up motion. The judicial precedent related to aviation accidents in Korea requires pilots' absolute and extended care compared to the ordinarily prudent or reasonably careful behaviors in the vehicle and medical accidents. Although there is some controversy about the standard care, the care required in the actual operation of high tech aircraft by a pilot should include objective and standard care and be judged by analysis of the scientific data. Although the pilot maintained the unusual hi speed that doesn't have safety margin and descended under turbulence in case of the JAL 706 accident, the court negatived its relation to the cause of pitch up. Also, the override of the control after initial pitch up might have caused the possibility of the death and injury, but the court denied it. Because of this complex cause of the aviation accidents, it is important for a court to figure out the core reason of the event and casual relationship with the pilot Now, It is required that the judgement of negligence in the aviation accidents should include an objective care with scientific data from simulated circumstances(or a simulator) as the Japanese court not from the theory of vehicle's negligence.