• 대한전기학회논문지:시스템및제어부문D
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• 제51권8호
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• pp.368-373
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• 2002

The inverse z-transform of a z-domain expression of a sequence can be Performed in many different methods among which the recursive computational method is based on the difference equation. In applying this method, a few initial values of the sequence should be obtained separately. Although the existing method generates the right initial values of the sequence, its derivation and justification are not theoretically in view of the definition of z-transform and its shift theorems. In this paper a general approach for formulating a difference equation and for obtaining required initial values of a sequence is proposed, which completely complies to the definition of the z-transform and an interpretation of the validity of the existing method which is theoretically incorrect.

• 대한전자공학회논문지
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• 제21권6호
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• pp.105-114
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• 1984

본 논문에서는 direct sequence(DS) 방식을 이용한 spread spectrum system에 사용할 수 있는 빠른 초기 동기 방법을 제안하였다. 수식적인 모델을 세우고 해석을 한 후 computer simulation을 거쳐 제안된 system의 성능을 분석하여 sliding correlator에 비해 우수함을 입증하였다. 입력 신호의 signal-to-noise ratio(SNR)가 -18dB에서 초기 동기 시간이 45ms 소요되었다. 이 방법의 hardsware 구현과 실험 결과도 설명하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.693-698
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• 2000

Aspects of classical information theory, such as rate distortion theory, investigate how to encode and decode information from an independently identically distributed source so that the asymptotic distortion rate between the source and its quantized representation is minimized. However, in most natural dynamics, the source state is highly corrupted by disturbances, and the measurement contains the noise. In recent coder-estimator sequence is developed for state estimation problem based on observations transmitted with finite communication capacity constraints. Unlike classical estimation problems where the observation is a continuous process corrupted by additive noises, the condition is that the observations must be coded and transmitted over a digital communication channel with finite capacity. However, coder-estimator sequence does not provide such a quantitative analysis as a variance for estimation error. In this paper, under the assumption that the estimation error is Gaussian distribution, a variance for coder-estimation sequence is proposed and its fitness is evaluated through simulations with a simple example.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권4호
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• pp.1307-1329
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• 2022

This paper proposes an improved Pseudorandom Sequence Generator (PRSG) based on the concept of modular arithmetic systems with non-integral numbers. The generated random sequence use in various cryptographic applications due to its unpredictability. Here the mathematical model is designed to solve the problem of the non-uniform distribution of the sequences. In addition, PRSG has passed the standard statistical and empirical tests, which shows that the proposed generator has good statistical characteristics. Finally, image encryption has been performed based on the sort-index method and diffusion processing to obtain the encrypted image. After a thorough evaluation of encryption performance, there has been no direct association between the original and encrypted images. The results show that the proposed PRSG has good statistical characteristics and security performance in cryptographic applications.

• 한국산림과학회지
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• 제96권4호
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• pp.425-431
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• 2007

Rhizina undulata의 PCR 검정 및 유전적 특성 분석을 목적으로, rDNA ITS 영역의 염기배열 해석 및 PCR 방법에 의한 토양으로부터 R. undulata의 진단법을 개발하였다. 18S rDNA 부분의 염기서열 분석 결과, 공시한 4종의 균주 모두 1,375 nt의 크기로 동일하였으며, 염기배열도 100% 일치하였다. 한편, rDNA ITS 영역의 염기배열은 585 nt이었고, PDK-1, PTT-1 및 PDJ-9 균주는 염기배열이 100% 동일하였으나, PDS-5균주에서는 두 곳에서 염기의 치환이 발견되었다. 이와 같은 염기배열을 분석하여 제작한 R. undulata rDNA ITS 영역 특이적 primer를 이용한 PCR 검정 결과, R. undulata 균주들에서만 약 525 bp 크기의 ITS 영역 특이적인 증폭산물이 검출되었다. PCR 방법에 의하여 검출할 수 있는 토양 중의 R. undulata 최소 균사량의 한계를 확인하기 위해서, 순수 배양한 R. undulata 균사현탁액을 순차 희석하여 100g의 사양토에 혼합한 다음, 농도별로 균사 혼합한 각각의 토양 시료로부터 추출한 total DNA의 PCR 증폭산물을 분석한 결과, PCR 방법에 의하여 100g의 토양 중에 1 ng의 R. undulata 균사가 함유되어 있는 경우까지 검출이 가능하였다.

• The Plant Pathology Journal
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• 제21권3호
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• pp.229-236
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• 2005

Molecular profIles of PCR-RFLP and sequence analysis of internal transcribed spacer (ITS) regions of rDNA were compared between morphologically distinguishable species of Trichoderma isolated from substrates of oyster mushroom in Korea, T. atroviride, T. citrinoviride, T. harzianum, T. longibrachiatum, T. virens, and two unidentified species, Trichoderma sp. 1 and 2. PCR­RFLP analysis divided the Trichoderma spp. into six RFLP groups, A, B, C, D, E, and F. The RFLP groups were generally agreed with described morphological species, except that the RFLP group A containing the two unidentified species. A neighbor-joining tree based on ITS sequences well supported RFLP groups observed by RFLP analysis of ITS regions of rDNA. Additionally, the two unidentified species, Trichoderma sp. 1 and 2, which could not be distinguished by PCR­RFLP analysis, were separated in sequence analysis of ITS regions of rDNA.

• 한국정보전자통신기술학회논문지
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• 제10권4호
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• pp.325-332
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• 2017

본 논문은 프로토콜 구현물이 프로토콜의 사양에 대한 적합성을 시험하기 위한 시험항목 생성방법들에 대하여 비교분석 한다. 대표적인 방법들인 천이 순회, 구별 시퀀스, 특징화 시퀀스, 유일 입출력 시퀀스와 변형된 이들 방법들을 분석하고, 유한 상태 기계 모델에 적용한 위의 방법들의 시험항목 길이를 비교 및 분석 한다. 결론에서는 프로토콜 적합성시험을 위한 시험항목 생성방법들에 대한 핵심적이고 분석적인 이슈 사안들을 다음과 같이 제시한다. 천이 순회 방법은 최단의 시험 항목을 생성하지만 최악의 오류 검출 성능을 제공한다. 특징화 시퀀스 방법은 완벽한 오류 검출 성능을 제공하지만 상대적으로 최장의 시험 항목을 생성한다. 구별 시퀀스 방법의 문제점은 이 구별 시퀀스가 항상 존재하지는 않는다는 것이다. 유일 입출력 시퀀스 방법이 비교적 폭넓게 적용될 수 있지만 구별 시퀀스 방법과 동일한 오류 검출 성능을 제공하지 못한다는 문제점이 있다.

• Bioinformatics and Biosystems
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• 제1권1호
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• pp.46-50
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• 2006

According to the advancement of experimental techniques in molecular biology, genomic and protein sequence databases are increasing in size exponentially, and mean sequence lengths are also increasing. Because the sizes of these databases become larger, it is difficult to search similar sequences in biological databases with significant homologies to a query sequence. In this paper, we present the N-gram indexing method to retrieve similar sequences fast, precisely and comparably. This method regards a protein sequence as a text written in language of 20 amino acid codes, adapts N-gram tokens of fixed-length as its indexing scheme for sequence strings. After such tokens are indexed for all the sequences in the database, sequences can be searched with information retrieval algorithms. Using this new method, we have developed a protein sequence search system named as ProSeS (PROtein Sequence Search). ProSeS is a protein sequence analysis system which provides overall analysis results such as similar sequences with significant homologies, predicted subcellular locations of the query sequence, and major keywords extracted from annotations of similar sequences. We show experimentally that the N-gram indexing approach saves the retrieval time significantly, and that it is as accurate as current popular search tool BLAST.

• Journal of Communications and Networks
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• 제14권3호
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• pp.230-236
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• 2012

Based on the known binary sequence sets and Gray mapping, a new method for constructing quaternary sequence sets is presented and the resulting sequence sets' properties are investigated. As three direct applications of the proposed method, when we choose the binary aperiodic, periodic, and Z-complementary sequence sets as the known binary sequence sets, the resultant quaternary sequence sets are the quaternary aperiodic, periodic, and Z-complementary sequence sets, respectively. In comparison with themethod proposed by Jang et al., the new method can cope with either both the aperiodic and periodic cases or both even and odd lengths of sub-sequences, whereas the former is only fit for the periodic case with even length of sub-sequences. As a consequence, by both our and Jang et al.'s methods, an arbitrary binary aperiodic, periodic, or Z-complementary sequence set can be transformed into a quaternary one no matter its length of sub-sequences is odd or even. Finally, a table on the existing quaternary periodic complementary sequence sets is given as well.

• 대한수학회지
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• 제35권2호
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• pp.281-294
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• 1998

In this paper, we extend the G-sequence of a CW-pair to the G-sequence of a map and show the existence of a map with nonexact G-sequence. We also give an example of a finite CW-pair with nontrivial $\omega$-homology in high order.