• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.260-263
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• 2002

There is great interest in developing magnetoresistance(MR) sensor, using ferromagnetic, electrically non-magnetic conducting and antiferromagnetic films, especially for the use in weak magnetic fields. Here, we report single and Wheatstone-bridge type of MR sensors made in Si(001)/NiO($300{\AA}$)/NiFe bilayers. Angular dependence of MR profiles was measured in Si(001)/NiO($300{\AA}$)/NiFe($450{\AA})$ films as a function of an angle between current and applied field direction, also, linearity was determined. AMR characteristics of single MR sensors was well explained with single domain model. Good linearity in $45^{\circ}$ Wheatstone-bridge type of MR sensors consisting of 4 single MR sensors made in Si(001)/NiO($300{\AA}$)/NiFe($450{\AA})$ was shown in the range of about ${\leq}{\pm}5$ Oe.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권6호
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• pp.1599-1618
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• 2024

Access control has always been one of the effective methods to protect data security. However, in new computing environments such as big data, data resources have the characteristics of distributed cross-domain sharing, massive and dynamic. Traditional access control mechanisms are difficult to meet the security needs. This paper proposes CACM-MMSR to solve distributed cross-domain access control problem for massive resources. The method uses blockchain and smart contracts as a link between different security domains. A permission decision model migration method based on access control logs is designed. It can realize the migration of historical policy to solve the problems of access control heterogeneity among different security domains and the updating of the old and new policies in the same security domain. Meanwhile, a semantic reasoning-based permission decision method for unstructured text data is designed. It can achieve a flexible permission decision by similarity thresholding. Experimental results show that the proposed method can reduce the decision time cost of distributed access control to less than 28.7% of a single node. The permission decision model migration method has a high decision accuracy of 97.4%. The semantic reasoning-based permission decision method is optimal to other reference methods in vectorization and index time cost.

• Journal of the Optical Society of Korea
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• 제18권6호
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• pp.766-771
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• 2014

Single-ring all-pass filters with various coupling ratios are designed, fabricated, and characterized to assess the validity of the split-step time-domain modeling approach, which is considered for direct simulation of time-domain characteristics, such as optical delay, of various ring resonator devices. When the coupling ratio of the single-ring all-pass filter is 0.4 and 0.8, the delay time is measured to be about 145 and 42 ps respectively, which is comparable to the time-domain modeling results of 151 and 47 ps respectively. The measurements for two- and three-ring all-pass filters are also found to agree quite well with the simulation results. With these results it is confirmed that the split-step time-domain model could be efficiently incorporated into an optical-communication simulation module for ring resonator delay components in an all-optical packet switching system.

• 한국정보과학회논문지:정보통신
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• 제32권3호
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• pp.291-300
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• 2005

유비쿼터스 컴퓨터 환경은 사용자가 언제 어디서나 컴퓨터를 이용할 수 있도록 네트워크를 통해 상호 연결된 보이지 않는 수많은 컴퓨터(Invisible Computer)가 편재되고 사용자가 원하는 대로 쉽게 이용할 수 있는 컴퓨팅 환경을 지향하고 더 나아가서는 사용자가 원하는 컴퓨팅을 컴퓨터 스스로 알아서 (상황인식 Context Awareness) 제공하는 스마트 환경이다. 이러한 유비쿼터스 컴퓨팅은 보안에 있어 특히 취약한 면을 많이 내포하고 있다. 그 중에서도 분산된 다양한 컴퓨팅 기기들이 도처에 존재함으로 인해 사웅자 주턴에 있는 기기 중에서 사웅자 혹은 서버에 인증된 기기로의 위장공격 등이 가능해진다. 이에 본 논문에서는 다음과 같은 특징을 가지는 방식을 제안한다. 디바이스의 이동을 통한 인증 모델을 제시한다. 이는 개인의 작은 디바이스가 다른 사용자의 공간(MD: Multi Domain)로 이동하였을 경우 디바이스를 통한 인증을 실쳔하는 방식과 사용자 자신의 공간(SD: SinEle Domain)으로 이동하였을 경우 디바이스를 통한 인증을 실현하는 두 가지 방식을 제안한다.

• BMB Reports
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• 제43권1호
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• pp.1-8
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• 2010

The cold shock domain (CSD) is among the most ancient and well conserved nucleic acid binding domains from bacteria to higher animals and plants. The CSD facilitates binding to RNA, ssDNA and dsDNA and most functions attributed to cold shock domain proteins are mediated by this nucleic acid binding activity. In prokaryotes, cold shock domain proteins only contain a single CSD and are termed cold shock proteins (Csps). In animal model systems, various auxiliary domains are present in addition to the CSD and are commonly named Y-box proteins. Similar to animal CSPs, plant CSPs contain auxiliary C-terminal domains in addition to their N-terminal CSD. Cold shock domain proteins have been shown to play important roles in development and stress adaptation in wide variety of organisms. In this review, the structure, function and regulation of plant CSPs are compared and contrasted to the characteristics of bacterial and animal CSPs.

• 한국멀티미디어학회논문지
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• 제25권6호
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• pp.819-832
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• 2022

Cross-domain recommender system transfers knowledge across different domains to improve the recommendation performance in a target domain that has a relatively sparse model. However, they suffer from the "negative transfer" in which transferred knowledge operates as noise. This paper proposes a novel Multiple Fusion-based Deep Cross-Domain Recommendation named MFDCR. We exploit Doc2Vec, one of the famous word embedding techniques, to fuse data user-wise and transfer knowledge across multi-domains. It alleviates the "negative transfer" problem. Additionally, we introduce a simple multi-layer perception to learn the user-item interactions and predict the possibility of preferring items by users. Extensive experiments with three domain datasets from one of the most famous services Amazon demonstrate that MFDCR outperforms recent single and cross-domain recommendation algorithms. Furthermore, experimental results show that MFDCR can address the problem of "negative transfer" and improve recommendation performance for multiple domains simultaneously. In addition, we show that our approach is efficient in extending toward more domains.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2022년도 추계학술발표대회
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• pp.308-310
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• 2022

With the rise of the Al wave, task-oriented dialogue systems have become one of the popular research directions in academia and industry. Currently, task-oriented dialogue systems mainly adopt pipelined form, which mainly includes natural language understanding, dialogue state decision making, dialogue state tracking and natural language generation. However, pipelining is prone to error propagation, so many task-oriented dialogue systems in the market are only for single-round dialogues. Usually single- domain dialogues have relatively accurate semantic understanding, while they tend to perform poorly on multi-domain, multi-round dialogue datasets. To solve these issues, we developed a paddle-based multi-domain task-oriented Chinese dialogue system. It is based on NEZHA-base pre-training model and CrossWOZ dataset, and uses intention recognition module, dichotomous slot recognition module and NER recognition module to do DST and generate replies based on rules. Experiments show that the dialogue system not only makes good use of the context, but also effectively addresses long-term dependencies. In our approach, the DST of dialogue tracking state is improved, and our DST can identify multiple slotted key-value pairs involved in the discourse, which eliminates the need for manual tagging and thus greatly saves manpower.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 1998년도 춘계연구발표회 논문개요집
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• pp.36-37
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• 1998

• 한국자기학회지
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• 제20권1호
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• pp.1-7
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• 2010

강자성 나노선에 형성된 자벽의 자기적 특성을 연구하기 위해 미세 자기 동역학을 이용하여 열적 자기 잡음에 대한 연구를 수행하였다. 열적 요동에 의한 자기 잡음 연구는 자성체의 중요한 물리량인 자화율이나 자기 공명 주파수와 같은 물리적 특성에 대한 정보를 제공해 주며, 이는 스핀 동역학의 연구에 있어서 중요한 역할을 한다. 본 연구는 강자성 나노선에서의 자기 구조가 단일 자구를 형성하고 있는 경우와 두 개의 자구 사이에 자벽이 있는 경우에 대해서 열적 자기 잡음을 분석하였다. 그 중 단일 자구일 경우에 열적 요동에 의한 공명 주파수는 완전한 타원체 모형에서 탈자기화 상수를 고려한 Kittel 방정식으로 매우 잘 설명됨을 확인하였고, 자벽이 존재하는 경우에는 단일 자구에 의한 공명 주파수 이외에 추가된 공명주파수를 확인 할 수 있었다. 국소적인 분석을 통해 앞에서 언급한 추가 공명 주파수는 자벽에서 발생하며 단일 자구에 의한 공명 주파수에 비해서 낮은 주파수를 가짐을 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권10호
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• pp.2692-2707
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• 2012

A separable identity-based ring signature scheme has been constructed as a fundamental cryptographic primitive for protecting user privacy. Using the separability property, ring members can be selected from arbitrary domains, thereby, giving a signer a wide range of ways to control privacy. In this paper we propose a generic method to construct efficient identity-based ring signature schemes with various levels of separability. We first describe a method to efficiently construct an identity-based ring signature scheme for a single domain, in which a signer can select ring identities by choosing from identities defined only for the domain. Next, we present a generic method for linking ring signatures constructed for a single domain. Using this method, an identity-based ring signature scheme with a compact structure, supporting multiple arbitrary domains can be designed. We show that our method outperforms the best known schemes in terms of signature size and computational costs, and that the security model based on the separability of identity-based ring signatures, presented in this paper, is highly refined and effective by demonstrating the security of all of the proposed schemes, using a model with random oracles.