• Nuclear Engineering and Technology
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• 제40권7호
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• pp.551-560
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• 2008

Radiation has stochastic aspects in its generation, its choice of interaction mode during traveling in media, and its impact on living bodies. In certain circumstances, like in high dose environments resulting from low-LET radiation, the variance in its impact on a target volume is negligible. On the contrary, in low dose environments, especially when they are attributed to high-LET radiation, the impact on the target carries with it a large variance. This variation is more significant for smaller target volumes. Microdosimetric techniques, which have been developed to estimate the distribution of radiation energy deposited to cellular and subcellular-sized targets, contrast with macrodosimetric techniques which count only the average value. Since cells and DNA compounds are the critical targets in human bodies, microdosimetry, or dose estimation by microscopic approach, helps one better analyze the biological effects of radiation on the human body. By utilizing microbeam systems designed for individual cell irradiation, scientists have discovered that human cells exhibit radiosensitive reactions without being hit themselves (bystander effect). During the past 10 or more years, a new therapeutic protocol using discontinuous multiple micro-slit beams has been investigated for its clinical application. It has been suggested that the beneficial bystander effect is the essence of this protocol.

• 정보처리학회논문지C
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• 제18C권6호
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• pp.405-412
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• 2011

본 논문에서 제안한 이동성 관리 기법은 PMIPv6(Proxy Mobile IPv6) 네트워크에서 HIP(Host Identity Protocol)과 멀티캐스팅을 기반으로 하며, 사용자는 서로 다른 관리 도메인간의 핸드오프가 허용된다. 이 기법의 주요 장점은 감소하는 시그널링 오버헤드와 패킷 손실을 가지는 두 가지 타입 노드의 도메인간 핸드오프를 가능하게 하는 것이다. 다시 말해서 이 기법은 네트워크 기반 이동성 지원기법인 멀티캐스팅 지원의 PMIPv6와 호스트 기반 이동성 지원방식인 HIP간의 상호작용을 가능하게 한다. 성능평가는 이 기법이 다른 전역적 이동성 관리 프로토콜과 비교하여 핸드오프 지연과 패킷 손실 측면에서 향상된다는 것을 입증한다.

• 정보보호학회논문지
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• 제13권6호
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• pp.107-112
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• 2003

IEEE 802.11 네트웍에서 핸드오버는 반복되는 인증 및 키교환 절차를 요구하며, 이는 seamless 무선랜 서비스를 제공하는데 있어 큰 방해요소가 된다. 이 논문에서는 IEEE 802.11f를 이용한 빠른 키교환 및 인증 방법을 제안한다. 특히, IEEE 802.11i의 4-way 핸드쉐이크를 표준에 벗어나지 않게 수정하므로써 pre-authentication을 이용했을 때 생길 수 있는 perfect forward secrecy문제를 해결한다. 제안하는 방법은 IEEE 802.11f의 context block과 IEEE 802.11i의 핸드쉐이크만을 이용하며, 핸드오버 시에 AAA 서버와의 통신을 요구하지 않으므로써 효율성을 높였다.

• 한국자기학회지
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• 제23권2호
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• pp.54-61
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• 2013

강자성체는 자구들의 상호작용으로 인해 잔류 자화가 남게 되는데, 전자전기 산업 및 국방 피탐지 분야에서는 이러한 잔류 자화량을 정밀하게 0으로 만드는 탈자기법이 요구된다. 하지만 현재 수행되는 탈자기법들은 경험과 실험에 의존한 방법들로, 새로운 재료의 개발에 따른 효율적인 탈자를 위해서는 강자성체의 히스테리시스 곡선을 반영한 탈자기법이 필요하다. 본 논문에서는 자성체의 물성적인 성질을 기반으로 정립된 Preisach 모델링 기법을 이용하여 Anhysteretic Deperm, Deperm-ME, Flash-Deperm에 따른 2차원 유한요소해석을 수행하였다. 탈자 전류에 의한 자기이력궤적의 분석을 통해 강자성체의 히스테리시스 곡선과 탈자 변수의 관계를 고찰하였으며, 이로써 탈자에 효율적인 전류 감소 형태를 제시하였다.

• 한국엔터테인먼트산업학회논문지
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• 제8권2호
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• pp.283-297
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• 2014

미래 인간의 삶은 사회, 경제, 정치와 개인 등 삶의 전 영역에 걸쳐 다학제적 기술의 파급효과 증대에 의해 혁신될 것이다. 특히 로봇 분야와 로봇을 이용한 차세대 게임 분야에서는 다학제적 기여와 상호작용에 의해 더욱 더 기술간 융합화가 가속화 될 것으로 전망된다. 본 연구는 지금까지의 "인간-로봇 인터페이스 기술"의 기술적인 한계 및 시공간적 제약을 뛰어넘는 새로운 인터페이스 모델로, 기존 인간-로봇 인터페이스 기술에서 가질 수 없는 다양한 모달리티(modality)들의 융합을 통해 보다 신뢰성 있으며 편하고 자유로운 "인간-로봇 인터페이스 기술"의 연구이다. 이족보행의 휴먼로봇과 모바일 기기 화면의 3D 콘텐츠(contents) 로봇(가상로봇)의 동작과 위치 값을 실시간적으로 연동하는 동기화(Synchronization) 엔진을 개발하고, 상호간의 정보를 주고받기 위한 무선 프로토콜(Protocol) 및 효율적인 티칭(Teaching)을 위한 학습에 의한, 다이렉트 티칭앤플레이(Direct Teaching & Play)의 티칭 프로그램 개발과, 이를 이용한 로봇 게임 시스템을 연구한다.

• 한국지구과학회지
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• 제31권5호
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• pp.521-530
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• 2010

This study aimed to explore how to characterize the earth science inquiry in schools in terms of science teaching interaction and constructivist teaching practice. The constructivist teaching practices were analyzed with Reformed Teaching Observation Protocol (RTOP) in three aspects including (1) student oriented class implementation, (2) subject knowledge and representation, and (3) classroom communication. Fourteen earth science classes were observed and scored with RTOP. The class was evaluated to be transitional stage in terms of constructivist teaching, e.g., moving toward student-centered teaching practice. Especially, Korean teachers tend to lean their classes more on propositional knowledge than procedural knowledge. To interpret science teaching interactions, an earth science teacher with a RTOP top rank was selected. Her class was then videotaped for detailed analysis. I adopted the analytical framework of communicative approaches and discourse patterns among the five aspects of interactions presented by Mortimer and Scott (2003). It was found that this earth science teacher used more authoritative patterns than the dialogic. In addition, she used IRE discourse pattern more frequently. Interestingly, teachers interacted with their students more frequently in the form of repeated (or IRE chain pattern), that is IRFRF (teacher initiation-student response-teacher feedback-student response-teacher feedback) in the context of dialogic communicative approaches, while simple IRE occurred in an authoritative approach. In earth science classrooms, typical interaction may well be constructed in the form of IRFRF chains to allow students free conjectures and abduction.

• BMB Reports
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• 제33권2호
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• pp.188-192
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• 2000

Recombinant protein G has been utilized in the purification of antibodies from various mammalian species based on the interaction of antibodies with protein G. The interaction between immunoglobulin and protein G may not be restricted to the Fc protion of antibodies, as many different $F(ab)_2$ or Fab fragments can also bind to protein G. I found both FAb $F(ab)_2$ of 145-2C11, a hamster anti-mouse $CD3{\varepsilon}$ antibody, bound to the protein G-sepharose. Interestingly, Fab and $F(ab)_2$ of 145-2C11 did not bind to the protein A-sepharose. The binding of Fab and $F(ab)_2$ of 145-2C11 to protein G provided a useful method to remove proteases, chopped fragments of the Fc region, and other contaminating proteins. The remaining intact antibody in the protease reaction mixture can be removed by using a protein A-sepharose, because the Fab and $F(ab)_2$ portions of 145-2C11 did not bind to protein A-sepharose. The specific binding of Fab and $F(ab)_2$ portions of 145-sC11 to a protein G-sepharose (though not to a protein A-sepharose) and binding of intact 145-2C11 to both protein A- and G-sepharose will be useful in developing an effective purification protocol for Fab and $F(ab)_2$ portions of 145-2C11.

• Journal of Communications and Networks
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• 제10권2호
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• pp.213-220
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• 2008

This paper analyzes a broadcasting technique for wireless multi-hop sensor networks that uses a form of cooperative diversity called opportunistic large arrays (OLAs). We propose a method for autonomous scheduling of the nodes, which limits the nodes that relay and saves as much as 32% of the transmit energy compared to other broadcast approaches, without requiring global positioning system (GPS), individual node addressing, or inter-node interaction. This energy-saving is a result of cross-layer interaction, in the sense that the medium access control (MAC) and routing functions are partially executed in the physical (PHY) layer. Our proposed method is called OLA with a transmission threshold (OLA-T), where a node compares its received power to a threshold to decide if it should forward. We also investigate OLA with variable threshold (OLA-VT), which optimizes the thresholds as a function of level. OLA-T and OLA-VT are compared with OLA broadcasting without a transmission threshold, each in their minimum energy configuration, using an analytical method under the orthogonal and continuum assumptions. The trade-off between the number of OLA levels (or hops) required to achieve successful network broadcast and transmission energy saved is investigated. The results based on the analytical assumptions are confirmed with Monte Carlo simulations.

• International Journal of Contents
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• 제2권4호
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• pp.12-18
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• 2006

The number of wireless public network user is increasing rapidly. Security problem for user authentication has been increased on existing wireless network such as IEEE802.11 based Wireless LAN. As a solution, IEEE802.1x (EAP-MD5, EAP-TLS, EAP-TTLS), X.509, protocol or security system was suggested as a new disposal plan on this problem. In this study, we overview main problem on existing EAP-MD5 authentication mechanism on Wireless LAN and propose a SMS(Short Message Service) based secure authentication and accounting mechanism for providing security enhanced wireless network transactions.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2005년도 가을 학술발표논문집 Vol.32 No.2 (1)
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• pp.241-243
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• 2005

Web services (WS) present a new promising software technology, which provides application-to-application interaction. They are built on the top of existing web protocol and based on open XML standards. Web services are described using WSDL, and the UDDI is a integration directory provide registry of Web Services descriptions. WSDL provides information of Web Services but it is getting more and more important to know more than those provided by WSDL. From WSDL we can not get the information like usage of WS, performance of WS, complexity of WS, usability of WS with other web service. In this paper, we proposed a new method for Web Services so called Public Web Services Analyzer (PWSA). This technique is based on analyzing various public UDDI registries in order to get various kinds of statistics of web services. Those statistics will be used by both web services developers and consumers for finding them suitable services for their needs. PWSA guarantees that it can provide enough information to find right web services for both Web Services Consumers and Web Service Developers.