• 대한전자공학회논문지TC
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• 제47권2호
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• pp.18-24
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• 2010

신뢰성 있는 채널 모델은 다양한 데이터 검출 알고리즘의 개발과 성능 평가에 중요한 척도가 되므로 정확한 모델링이 요구된다. 본 논문에서는 Super-RENS (Super-Resolution Near-field Structure) 시스템의 비선형 모델링을 위해 정규 구간선형 모델 (canonical piecewise-linear; PWL)과 2차 볼테라 (second-order Volterra) 모델을 적용하고자 한다. 또한 이를 바탕으로 비선형 심볼간 간섭 (Inter-Symbol Interference; ISI)을 제거하기 위해 새로운 비선형 등화기를 제안한다. Super-RENS 디스크로부터 획득한 RF 신호 샘플들을 사용하여 모의실험을 수행한 결과, Super-RENS 시스템의 비선형 모델링을 위해 정규 구간선형 모델과 2차 볼테라 모델이 유용하게 활용될 수 있다는 가능성을 확인하였고 제안된 비선형 등화기의 성능은 비트오율 측면에서 등화기가 없는 경우보다 우수한 성능을 나타내었다.

• 융합신호처리학회논문지
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• 제2권2호
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• pp.111-118
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• 2001

본 연구에서는 패턴 인식용 다층 퍼셉트론 신경망을 순수 디지털 논리회로 모델로 구현할 수 있도록 새로운 논리뉴런의 구조, 디지털 정형 다층논리신경망 구조, 그리고 패턴인식의 응용을 위한 다단 다층논리 신경망 구조를 제안하고, 또한 제안된 구조는 매우 단순하면서도 효과적인 증가적인 가법적(Incremental Additive) 학습알고리즘이 존재함을 보였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권5호
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• pp.956-967
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• 2010

Rapid growth of internet applications has increased the importance of intrusion detection system (IDS) performance. String matching is the most computation-consuming task in IDS. In this paper, a new algorithm for multiple string matching is proposed. This proposed algorithm is based on the canonical Aho-Corasick algorithm and it utilizes a bidirectional and parallel processing structure to accelerate the matching speed. The proposed string matching algorithm was implemented and patched into Snort for experimental evaluation. Comparing with the canonical Aho-Corasick algorithm, the proposed algorithm has gained much improvement on the matching speed, especially in detecting multiple keywords within a long input text string.

• 대한수학회논문집
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• 제9권2호
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• pp.393-400
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• 1994

Let M(f,η,ξ,g) be a (2m ＋ 1)-dimensional Sasakian manifold with soldering form dp ∈ ΓHom(Λ/sup q/TM, TM) (dp: canonical vector-valued 1-form) where f,η,ξ and g are the (1,1)-tensor field, the structure 1-form, the structure vector field and the metric tensor of M, respectively.(omitted)

• 영어영문학
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• 제57권6호
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• pp.1017-1041
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• 2011

This study investigates Korean EFL learners' awareness and use of the English existential there-construction by examining data collected from 54 Korean EFL learners of English by means of a pragmalinguistic judgment task and a controlled discourse completion task. The results of the judgment task reveal that lower proficiency learners rated canonical sentences and existentials with a preposed locative best in the communicative situations where the use of existentials would have been most appropriate. A comparison of the ratings by more proficient learners and native speakers shows that existentials received highest ratings by both groups where they are the most natural option, while canonical sentences received significantly higher ratings by the learners. With regard to the production data, learners tended to avoid existentials, but rather relied on canonical sentences. Existentials were rarely used by lower proficiency learners and not used productively even by more proficient learners in the situations where existentials would have been the most natural option. These results suggest that Korean learners' difficulty with the use of existentials is not merely a product of performance limitations, but attributable to limited knowledge about existentials and their syntactic alternatives in terms of contextual appropriateness. Lower proficiency learners lack such knowledge, and more proficient learners, while showing better awareness of the use of existentials, have problems as to the placement of new information when engaging in writing tasks that place lower level of demands on attention to the information status of noun phrases compared to communicative, oral tasks.

• 한국해양공학회지
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• 제10권3호
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• pp.96-104
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• 1996

Hamilton's principle is used to derive Euler-Lagrange equations for free surface flow problems of incompressible ideal fluid. The velocity field is chosen to satisfy the continuity equation a priori. This approach results in a hierarchial set of governing equations consist of two evolution equations with respect to two canonical variables and corresponding boundary value problems. The free surface elevation and the Lagrange's multiplier are the canonical variables in Hamilton's sense. This Lagrange's multiplier is a velocity potential defined on the free surface. Energy is conserved as a consequence of the Hamiltonian structure. These equations can be applied to waves in water of finite depth including generalization of Hamilton's equations given by Miles and Salmon.

• 대한수학회지
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• 제36권5호
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• pp.959-1008
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• 1999

This paper considers foundational issues related to connections in the tangent bundle of a manifold. The approach makes use of second order tangent vectors, i.e., vectors tangent to the tangent bundle. The resulting second order tangent bundle has certain properties, above and beyond those of a typical tangent bundle. In particular, it has a natural secondary vector bundle structure and a canonical involution that interchanges the two structures. The involution provides a nice way to understand the torsion of a connection. The latter parts of the paper deal with the Levi-Civita connection of a Riemannian manifold. The idea is to get at the connection by first finding its.spary. This is a second order vector field that encodes the second order differential equation for geodesics. The paper also develops some machinery involving lifts of vector fields form a manifold to its tangent bundle and uses a variational approach to produce the Riemannian spray.

• Earthquakes and Structures
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• 제10권1호
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• pp.25-51
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• 2016

In this study, graph product rules are applied to the dynamic analysis of regular skeletal structures. Graph product rules have recently been utilized in structural mechanics as a powerful tool for eigensolution of symmetric and regular skeletal structures. A structure is called regular if its model is a graph product. In the first part of this paper, the formulation of time history dynamic analysis of regular structures under seismic excitation is derived using graph product rules. This formulation can generally be utilized for efficient linear elastic dynamic analysis using vibration modes. The second part comprises of random vibration analysis of regular skeletal structures via canonical forms and closed-form eigensolution of matrices containing special patterns for symmetric structures. In this part, the formulations are developed for dynamic analysis of structures subjected to random seismic excitation in frequency domain. In all the proposed methods, eigensolution of the problems is achieved with less computational effort due to incorporating graph product rules and canonical forms for symmetric and cyclically symmetric structures.

• 한국통신학회논문지
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• 제27권4A호
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• pp.324-329
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• 2002

Digital If(Intermediate frequency) 처리단과 같은 고속과 저전력을 요구하는 필터에서 덧셈기만을 사용하여 CSD(Canonical Signed Digit)형의 필터계수들을 구현하는 구조가 널리 연구되고 있다. 본 논문에서는 CSD형의 선형위상 FIR(Finite Impulse Response) 필터에서 수직의 공통패턴을 공유하는 구조를 제안한다. 선형위상 FIR 필터를 CSD형의 코드를 사용하여 구현할 때에, 선형위상의 계수대칭의 특성 때문에 수평 공통패턴의 방식이 사용되어 왔다. 그러나 본 논문에서는 선형위상 필터는 근접해 있는 계수들끼리 근사의 값을 갖기 때문에 MSB가 같다는 것을 이용하여 수직 공통패턴을 사용하는 방식을 제안하였다. 제안된 방식은 구현의 정세도가 낮을수록, 구현하는 탭의 길이가 길수록 더욱 효과가 큼을 예제를 통하여 보였다. 따라서 제안된 방식은 고 고속/저전력 구현을 요하는 이동 통신용 필터에서 사용하기에 적합한 필터임을 보였다.

• Journal of Microbiology
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• 제45권1호
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• pp.79-82
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• 2007

The 58 rRNA gene from Sphingobium chungbukense DJ77 was identified. The secondary structure of the 199-base-long RNA was proposed. The two-base-long D loop was the shortest among all of the known 5S rRNAs. The U19-U64 non-canonical pair in the helix II region was uniquely found in strain DJ77 among all of the sphingomonads.