• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.396-396
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• 2010

최근에 자구벽 이동을 이용한 race track memory, 혹은 나노자성체의 자구 동역학 등에 대한 관심이 집중되고 있다. 용량은 하드디스크의 크기를 가지며 속도는 SRAM, 집적도는 DRAM에 필적하는 새로운 메모리의 실현은 지금까지 이용되는 대부분의 메모리를 대체할 가능성이 있다. 이러한 메모리의 개발에 가장 기본이 되는 측정기술은 나노크기의 자성 구조체에서 자구 혹은 자구벽 이동을 측정하는 기술로써 현재 국내에서 자성 나노구조의 자화방향과 더불어 topography를 동시에 측정할 수 있는 장치는 본 SEMPA가 유일하다. SEMPA는 기존에 사용되어지던 SEM(전자 현미경) 에서 알 수 있는 나노 구조의 형상이외에 전자의 스핀방향을 검출함으로써 형상과 스핀의 결함된 imaging 을 할 수 있다. 일반적으로 기존의 SEM의 경우 고 에너지빔의 전자빔을 주사시키고 이때 발생되는 이차 전자의 수를 2차원상의 영역에 따라 달라지는 비로 mapping 을 하게 된다. 이때 전자의 수뿐만 아니라 이들의 스핀편향(spin polarization) 을 측정할 수 있다면 형상뿐만 아니라 표면에서의 스핀상태를 동시에 측정 할 수 있게 된다. 본 발표에서는 이 방법을 이용하여 나노구조체의 자구측정 결과를 제시하고자 한다.

• The KIPS Transactions:PartC
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• v.10C no.5
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• pp.565-574
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• 2003

This paper implements an intrusion detection message exchange protocol library (IDMEPL) for SDMS-RTIR, which Korea Information Security Agency (KISA) has developed to hierarchically detect and respond to network vulnerability scan attacks. The IDMEPL, based on the IDMEF and the IAP of the IDWG, enables SDMS-RTIR to interact with other intrusion detection systems (IDS) in realtime, and supports the TLS protocol to prevent security threats in exchanging messages between its server and its agents. Especially, with the protocol selection stage, the IDMEPL can support various protocols such as the IDXP besides the IAP. Furthermore, it can allow for agents to choose an appropriate security protocol for their own network, achieving security stronger than mutual authentication. With the IDMEPL, SDMS-RTIR can receive massive intrusion detection messages from heterogeneous IDSes in large-scale networks and analyze them.

• Journal of Veterinary Clinics
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• v.28 no.4
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• pp.387-393
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• 2011

Polygoni Multiflori Radix (PMR) a dried root tuber of Polygonum multiflorum Thunberg with bioactivities in bone metabolism is one of the most famous tonic traditional medicines in China, Japan and Korea.To observe the anti-osteoporotic effect of PMR, we observed the effects on proliferation and alkaline phosphatase (ALP) activity of primary osteoblasts, bone nodule formation, pit formation of osteoclasts and osteoclastogenesis in vitro. As the result of that, although PMR extracts have no meaningful changes on the the proliferation of primary osteoblasts, significant (p < 0.01) increases of ALP acitivity of osteoblasts were dose-dependently observed in all PMR extracts treated groups tested compared to that of vehicle control. It means that it enhanced the differentiation (ALP activity) and bone nodule formation of osteoblast. In addition, PMR extracts dose-dependently inhibits the pit formation and the number of multinucleated osteoclast-like cells (OCLs), osteoclastogenesis in vitro. Therefore these results show the possibility of PMR extracts as another anti-osteoporotic agents.

• Journal of Veterinary Clinics
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• v.28 no.4
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• pp.375-386
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• 2011

Polygoni Multiflori Radix (PMR), a dried root tuber of Polygonum multiflorum Thunberg with bioactivities in bone metabolism is one of the most famous tonic traditional medicines. To observe in vivo anti-osteoporotic efficacy of PMR extracts, we orally administered once a day for 28 days (Qd ${\times}$ 28) to bilateral ovariectomized (OVX)-induced osteoporosis ddY mice after 1 week of recovery periods at 125, 250 and 500 mg/kg (of body weight). A positive control drug, Alendronate (FOSA) 10 mg/kg-dosing group was added. As results of OVX-induced osteoporotic process, estrogen-deficient osteoporotic changes were also dramatically decreased in all PMR extracts-dosing groups. Especially middle dosage of PMR extracts, 250 mg/kg constantly and significantly (p < 0.01 or p < 0.05) inhibited the loss of bone strength and bone quality. Based on the results, it was concluded that PMR extracts (125, 250 or 500 mg/kg; orally dosing) has relatively good favorable effect to prevention and/or treatment of OVX-induced osteoporosis. Therefore, although the efficacy was slighter than that of Alendronate on the inhibition of bone loss, it is expected that PMR extracts will be promising as a new anti-osteoporotic agents for prevent the fracture induced in osteoporotic patients because natural herbal medicine origin PMR extracts will be dose not show serious side effects especially the problem in upper alimentary irritation by bisphosphonate and hypercalcaemia of parathyroid hormone analogs.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.1
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• pp.153-168
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• 2016

This paper introduces a structure, features and programming techniques for the CNG(Cryptography API: Next Generation), which is the substitution of the CAPI(Cryptography API) from Microsoft. The CNG allows to optimize a scope of functions and features because it is comprised of independent modules based on plug-in structure. Therefore, the CNG is competitive on development costs and agility to extend. In addition, the CNG supports various functions for the newest cryptographic algorithm, audit, kernel-mode programming with agility and possible to contribute for core cryptography services in a new environment. Therefore, based on these advantageous functions, we analyze the structure of CNG to extend it for the enterprise and the public office. In addition, we implement an error-detection tool for program which utilizes CNG library.

• Journal of Internet Computing and Services
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• v.6 no.5
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• pp.11-25
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• 2005

In MIPv6 environment, an important design consideration for public key based binding update protocols is to minimize asymmetric cryptographic operations in mobile nodes with constraint computational power, such as PDAs and cellular phones, For that, public key based protocols such as CAM-DH. SUCV and Deng-Zhou-Bao's approach provides an optimization to offload asymmetric cryptographic operations of a mobile node to its home agent. However, such protocols have some problems in providing the optimization. Especially, CAM-DH with this optimization does not unload all asymmetric cryptographic operations from the mobile node, while resulting in the home agent's vulnerability to denial of service attacks. In this paper, we improve the drawbacks of CAM-DH. Furthermore, we adopt Aura's two hash-based CGA scheme to increase the cost of brute-force attacks searching for hash collisions in the CGA method. The comparison of our protocol with other public key based protocols shows that our protocol can minimize the MN's computation overhead, in addition to providing better manageability and stronger security than other protocols.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.4
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• pp.691-699
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• 2009

Recently, the ERO protocol has been adopted as a standard to protect the routing optimization mode introduced by MIPv6. This protocol uses the public key cryptography and the early binding update method to improve the Return Routeability protocol while optimizing both security and performance. On the other hand, though various security approaches including the ERO protocol have been proposed for MIPv6, they lack formal verification. Especially, to our best knowledge, there is no formal analysis on the ERO protocol. In order to provide a good example for formal analysis on MIPv6 security protocols, this paper verifies the correctness of the ERO protocol through BAN-logic. For this goal, BAN-logic is extended to consider the address tests on the mobile nodes's CoA and HoA. It is expected that the analysis presented in this paper will be useful for the formal verifications on the security protocols related to MIPv6.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.5
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• pp.21-30
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• 2005

Recently, a mobile IPv6 binding update protocol using Address Based Keys (BU-ABK) was proposed. This protocol applies Address Based Keys (ABK), generated through identity-based cryptosystem, to enable strong authentication and secure key exchange without any global security infrastructure. However, because it cannot detect that public cryptographic parameters for ABKs are altered or forged, it is vulnerable to man-in-the-middle attacks and denial of service attacks. Furthermore, it has heavy burden of managing the public cryptographic parameters. In this paper, we show the weaknesses of BU-ABK and then propose an enhanced BU-ABK (EBU-ABK). Furthermore, we provide an optimization for mobile devices with constraint computational power. The comparison of EBU-ABK with BU-ABK shows that the enhanced protocol achieves strong security while not resulting in heavy computation overhead on a mobile node.

• The KIPS Transactions:PartC
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• v.11C no.5
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• pp.605-612
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• 2004

In MIPv6, unauthenticated binding updates expose the involved MN and CN to various security attacks. Thus, protecting the binding update process becomes of paramount importance in the MIPv6, and several secure binding update protocols have been proposed. In this paper, we pro-pose a novel protocol for the secure binding updates in MIPv6, which can resolve the drawbacks of the Deng-Zhou-Bao's protocol ［2］, by adopt-ing Aura's CGA scheme with two hashes ［9］. Aura's scheme enables our protocol to achieve stronger security than other CGA-based protocols without a trusted CA, resulting in less cost of verifying the HA's public key than the Deng-Zhou-Bao's protocol. Through the comparison of our protocol with other protocols such as the Deng-Zhou-Bao's protocol, CAM-DH and SUCV, we show that our protocol can provide better performance and manageability in addition to stronger security than other approaches.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.2
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• pp.285-292
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• 2009

In 2005, Lee and Chen suggested an enhanced one-time password authentication scheme which can prevent the stolen verifier attack that the Yeh-Shen-Whang's scheme has. The Lee-Chen's scheme addresses the stolen verifier attack by deriving each user's pre-shared secret SEED from the server secret. However, we investigated the weakness of the Lee-Chen's scheme and found out that it was suffering from the off-line dictionary attack on the server secret. We demonstrated that the off-line dictionary attack on the server secret can be easily tackled with only the help of the Hardware Security Modules (HSM). Moreover, we improved the scheme not to be weak to the denial of service attack and allow compromise of the past session keys even though the current password is stolen. Through the comparison between the Lee-Chen's scheme and the proposed one, we showed that the proposed one is stronger than other.