• Journal of KIISE:Information Networking
• /
• v.30 no.5
• /
• pp.604-613
• /
• 2003

Network Address Translation-Protocol Translation(NAT-PT) is an IPv4/IPv6 translation mechanism, as defined in RFC2766, allowing IPv6-only devices to communicate with IPv4-only devices and vice versa. But NAT-PT has the restriction that applies to IPv4 NAT where NAT-PT does not provide end-to-end security, which is a major goal of IPSec. Therefore it cannot support security services such as confidentiality, authentication, and integrity. In this paper, we propose secure NAT-PT(SNAT-PT) and the corresponding secure host architecture to support IPSec security service. And also tunneling scheme using dummy IP header is presented to show the valid operation of end-to-end IPSec protocol on the proposed architectures.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.11S
• /
• pp.3714-3722
• /
• 2000

The research related to the mobility support in the Internet can he classified into two fields. One is Macro mobility and the other is Micro mobility In case of \lacro Mobility, the standard, RFC 2002 by IETF is getting focused. But for Micro mobility, a variety of strategies have been discussed. In this paper. we introduce the concept of an LA and propose the strategy that makes it possible for the LA to fully concern frequent local handoff without using the HA. Therefore we can limit the longest handoH delay to a certain degree regardless of the distance between the MN and the HA of the MN. For the registration cost and the packet drop probability due to the registration delay, we prove the performance enhancement of the existing Mobile IP in case that we apply the concept of the LA to existing Mobile IP.

• The Journal of the Korean Society for Microbiology
• /
• v.22 no.2
• /
• pp.163-166
• /
• 1987

A new method for rosette assay is described for the detection of antigen-specific lymphocytes from BCG-infected mice using sheep erythrocytes coated with BCG antigen. The optimal concentration of BCG antigen for preparation of indicator cells and the incubation time of antigen coated erythrocytes-lymphocytes mixture were $50\;{\mu}g/ml$ and 1 h, respectively. The number of rosette-forming cells (RFC) during the course of BCG infection showed gradual increase as infection progressed and RFC was reached maximum (about 5-7% of splenic lymphocytes formed rosette) at 3 or 4 weeks after infection.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.10a
• /
• pp.838-839
• /
• 2016

IEEE 802.15.4 is the standard wireless link technology for low power, low cost, but long lifetime applications including wireless sensor network (WSN). Currently, whether or not IP architecture should be used in WSN over its 802.15.4 link is under dispute. Such kind of arguments may last for a long time without some convincing experimental measurements of real case performances of IP over 802.15.4 implementation, and thus prevent the advance of related research. In RFC4944, IETF proposed the 6LoWPAN specification to enable IPv6 communication over low power, wireless personal area networks. We try to alleviate the dispute and make the direction clearer to the community so as to promote further valuable research in this topic.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.16 no.1
• /
• pp.87-96
• /
• 2006

In this paper, we examine general digital evidence collection process which is according to RFC3227 document[l], and establish specific steps for memory information collection. Besides, we include memory dump process to existing digital evidence collection process, and examine privacy information through dumping real user's memory and collecting pagefile which is part of virtual memory system. Especially, we discovered sensitive data which is like password and userID that exist in the half of pagefiles. Moreover, we suggest each analysis technique and computer forensic process for memory information and virtual memory.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.16 no.5
• /
• pp.35-46
• /
• 2006

The current Internet Key Exchange protocol(IKE) which has been used for key exchange of security system was pointed out the faults of scalability, speed, efficiency and stability. In this research, we tried to resolve those faults, and implemented the newly designed IKEv2 protocol in the IPsec test bed system. In the trend of network expansion, the current Internet Key Exchange protocol has a limitation of network scalability, so we implemented the new Internet Key Exchange protocol as a recommendation of RFC proposal, so as to resolve the fault of the key exchange complexity and the speed of authentication process. We improved the key exchange speed as a result of simplification of complex key exchange phase, and increased efficiency with using the preexistence state value in negotiation phase.

• Geomechanics and Engineering
• /
• v.30 no.1
• /
• pp.75-91
• /
• 2022

This paper aims to show how to use several Machine Learning (ML) methods to estimate the TBM penetration rate systematically (TBM-PR). To this end, 1125 datasets including uniaxial compressive strength (UCS), Brazilian tensile strength (BTS), punch slope index (PSI), distance between the planes of weakness (DPW), orientation of discontinuities (alpha angle-α), rock fracture class (RFC), and actual/measured TBM-PRs were established. To evaluate the ML methods' ability to perform, the 5-fold cross-validation was taken into consideration. Eventually, comparing the ML outcomes and the TBM monitoring data indicated that the ML methods have a very good potential ability in the prediction of TBM-PR. However, the long short-term memory model with a correlation coefficient of 0.9932 and a route mean square error of 2.68E-6 outperformed the remaining six ML algorithms. The backward selection method showed that PSI and RFC were more and less significant parameters on the TBM-PR compared to the others.

• The Journal of Korean Medicine
• /
• v.16 no.1 s.29
• /
• pp.295-318
• /
• 1995

In order to investigate the effect of Houttuynia cordata Thunb and Sanggukeum on immune function, the author performed this experimental study. Delayed type hypersensitivity (DTH) and rosette forming cells(RFC) for cell-mediated immune response, hemagglutinin (HA) titers, hemolysin (HL) titers and plaque forming cells (PFC) for humoral immune response, immunoglogbulin (Ig G) titer, splenic natural Killer cell activity (NKCA) carbon clearance for phagocytic function of MPS(mononuclear phagocyte system) and change of weight were measured in ICR mice. The results were summarized as follows ; 1. DTH was increased with statistical significance in all of the treated group as compared with the control group. 2. RFC was increased with statistical significance in case of Houttuynia cordata Thunb but in case of sanggukeum and gamisanggukeum valuable increase of RFC was not recognized as compared with the control group. 3. HA titers were increased with statistical significance in case of Houttuynia cordata Thunb but in cases of Sanggukeum and Gamisanggukeum HA titers were not recognized as compared with the control group. 4. HL titers were increased with statistical significance in case of Houttuynia cordata Thunb but in cases of Sanggukeum and Gamisanggukeum valuable increase of HL titer was not recognized as compared with the control group. 5. PFC was increased in all of the treated group but valuable increase of PFC was not recognized as compared with the controal group. 6. Ig G titers were increased in all of the treated group but valuable increase of Ig G titer was not recognized as compared with the control group. 7. NKCA was increased with statistical significance in case of Houttuynia cordate Thunb but in case of Sanggukeum and Gamisanggukeum valuable increase of NKCA was not recognized as compared with the control group. 8. Carbon clearance was increased with statistical significance in case of Sanggukeum but in case of Houttuynia cordata Thunb and Gamisanggukeum valuable increase of carbon clearance was not recognized as compared with the control group. 9. Change of weight was increased with statistical significance in all of the treated group. Through in vivo experimental study in ICR mice, Houttuynia cordata Thunb enhances the cell-mediated immune responce, the humoral immune responce and natural killer cell activity. And Houttuynia cordata Thunb enhances immune responce as compared with that plused Sanggukeum. Sanggukeum enhances carbon clearance and enhances a little cell-mediated immune responce, the humoral immune response and natural killer cell activity. According to the above results it seems Houttuynia cordata Thunb and Sanggukeum was able to use Infection, Inflammation and Tumor.

• Journal of Electrochemical Science and Technology
• /
• v.7 no.1
• /
• pp.41-51
• /
• 2016

In the stratosphere, the air is stable and a photovoltaic (PV) system can produce more solar energy compared to in the atmosphere. If unmanned aerial vehicles (UAVs) fly in the stratosphere, the flight stability and efficiency of the mission are improved. On the other hand, the weakened lift force of the UAV due to the rarefied atmosphere can require more power for lift according to the weight and/or wing area of the UAV. To solve this problem, it is necessary to minimize the weight of the aircraft and improve the performance of the power system. A regenerative fuel cell (RFC) consisting of a fuel cell (FC) and water electrolysis (WE) combined PV power system has been investigated as a good alterative because of its higher specific energy. The WE system produces hydrogen and oxygen, providing extra energy beyond the energy generated by the PV system in the daytime, and then saves the gases in tanks. The FC system supplies the required power to the UAV at night, so the additional fuel supply to the UAV is not needed anymore. The specific energy of RFC systems is higher than that of Li-ion battery systems, so they have less weight than batteries that supply the same energy to the UAV. In this paper, for a stratospheric long-endurance hybrid UAV based on an RFC system, three major design factors (UAV weight, wing area and performance of WE) affecting the ability of long-term flight were determined and a simulation-based feasibility study was performed. The effects of the three design factors were analyzed as the flight time increased, and acceptable values of the factors for long endurance were found. As a result, the long-endurance of the target UAV was possible when the values were under 350 kg, above 150 m² and under 80 kWh/kg H₂.

• Review of KIISC
• /
• v.10 no.4
• /
• pp.23-32
• /
• 2000

본 논문에서는 전자서명법 제20조에서 명문화된 시점확인서비스(타임스탬프)에 대한 동향을 분석하였다. 현재 타임스탬프 서비스는 IETF PKIX에서 1997년 처음 인터넷 드래프트가 발표된 이후 RFC로 표준화가 추진 중이며 ISO/IEC JTC1/SC27에서도 표준화가 추진 중이다. 공개키기반구조의 필수적 요소로서 전자서명 인증 서비스와 함께 구현이 필요한 타임스탬프 서비스에 대한 표준화 동향 및 타임스탬프 서비스 프로토콜에 대한 분석과 국외 서비스 업체의 서비스 제공 현황을 분석하여 타임스탬프 응용 서비스 개발에 활용할 수 있도록 작성하였다.