• Journal of the Optical Society of Korea
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• v.9 no.3
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• pp.103-106
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• 2005

Recently, polymethyl methacrylate based plastic optical fibers (POFs) have attracted considerable attention as a potential medium for local area network (LAN) and home network applications. Since the POFs have very low optical loss at around 650mm, in particular, it becomes quite important to develop GHz transmitters operating at this wavelength for high bit rate optical transmission applications of the POFs. In this paper, we present generation of ${\geq}1.5 Gbps$ pseudo-random binary sequence optical signals by using a gain switched InGaA1P Fabry-Perot semiconductor laser with a high frequency filter, operating at 650mm, and the application of these signals to bandwidth measurement of POFs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.2A
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• pp.164-169
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• 2009

This paper presents a fast and accurate ranging algorithm for the WiBro system. The proposed algorithm detects a received ranging code and estimates its propagation delay using the correlation characteristics of the PRBS (Pseudo Random Binary Sequence) and the circular shift property of the discrete Fourier transform operator. The proposed ranging algorithm was applied to array antenna systems to show how it could improve the ranging performance of an array antenna system compared to a conventional base station system, which uses only a single antenna.

• Applied Chemistry for Engineering
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• v.4 no.4
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• pp.770-775
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• 1993

Chemical structure of poly(ethylene terephthalate-co-1, 4-cyclohexylene dimethylene terephthalate), P(ET-CT) copolyesters was investigated by High Resolution NMR analysis. The copolymer composition and isomeric ratio were determined by methylene resonance peaks which were separated into three peaks corresponding to ET, trans CT and cis CT units, respectively. The copolymer sequence distribution was evaluated from the carbon resonance peaks connected to carbonyl groups in benzene, indicating died distribution. According to statistics model, these copolyesters are almost random copolymers. The copolymer sequence distribution could be simulated and its averaged length was calculated by random copolymer statistics.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7A
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• pp.727-734
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• 2004

Collision Management Protocol (CMP) efficiently resolves collisions when data frames are transmitted in networks consisting of HomPNA 3.0 asynchronous MAC mode device with random access. Unlike Distributed Fair Priority Queueing (DFPQ) algorithm in HomePNA 2.0 or Binary Exponential Backoff (BEB) algorithm in IEEE 802.11, order of retransmission is decided according to Collision Signaling Sequence (CSS) values allocated to each device. Thus, CMP can minimize the number of mean collisions because order of retransmission is decided in a deterministic way. In this paper. we evaluate the saturation performance of CMP in HomePNA 3.0 using an analytic method.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.2
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• pp.93-97
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• 2010

This paper presents the improved KLT(Kanade-Lucas-Tomasi) of registration of Image sequence captured by camera mounted on unmanned helicopter assuming without camera attitude information. It consists of following procedures for the proposed image registration. The initial interested points are detected by characteristic curve matching via dynamic programming which has been used for detecting and tracking corner points thorough image sequence. Outliers of tracked points are then removed by using Random Sample And Consensus(RANSAC) robust estimation and all remained corner points are classified as inliers by homography algorithm. The rectified images are then resampled by bilinear interpolation. Experiment shows that our method can make the suitable registration of image sequence with large motion.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.939-942
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• 1998

본 논문에서는 랜덤 시퀀스와 직교코드를 이용하여 비화성이 강한 디지털 정보은폐 방법을 제시하였다.

• Mycobiology
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• v.42 no.1
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• pp.46-51
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• 2014

A degenerated strain of Pleurotus eryngii KNR2312 was isolated from a commercial farm. Random amplified polymorphic DNA analysis performed on the genomic DNA of the normal and degenerated strains of this species revealed differences in the DNA banding pattern. A unique DNA fragment (1.7 kbp), which appeared only in the degenerated strain, was isolated and sequenced. Comparing this sequence with the KNR2312 genomic sequence showed that the sequence of the degenerated strain comprised three DNA regions that originated from nine distinct scaffolds of the genomic sequence, suggesting that chromosome-level changes had occurred in the degenerated strain. Using the unique sequence, three sets of PCR primers were designed that targeted the full length, the 5' half, and the 3' half of the DNA. The primer sets P2-1 and P2-2 yielded 1.76 and 0.97 kbp PCR products, respectively, only in the case of the degenerated strain, whereas P2-3 generated a 0.8 kbp product in both the normal and the degenerated strains because its target region was intact in the normal strain as well. In the case of the P2-1 and P2-2 sets, the priming regions of the forward and reverse primers were located at distinct genomic scaffolds in the normal strain. These two primer sets specifically detected the degenerate strain of KNR2312 isolated from various mushrooms including 10 different strains of P. eryngii, four strains of P. ostreatus, and 11 other wild mushrooms.

• The Journal of the Acoustical Society of Korea
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• v.9 no.2
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• pp.42-52
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• 1990

A method of measuring impulse response of acoustic system, two kinds of cross-correlation methods (the direct correlation method and the M-sequence modulation correlation method) were applied. According to the direct correlation method, by using stationary random noise source and by calculating the cross-correlation function between the sourece and the output signal, equivalent impulse response can be obtained not being influenced by the back ground noises. By applying this method, the measurement of echo-time patterns in rooms and oblique incident sound absorption characteristics of sound absorbing materials was carried out. In the case of the M-sequence modulation correlation method which was contrived by Aoshima, an intermittent random nosie modulated by M-sequence signal is used as the source signal, and the cross-correlation function between the M-sequence signal and the squared output signal is calculated. According to this method, equivalent energy impulse response (squared impulse response) of te propagation system can be obtained without being influenced by the back ground noises and the air fluctuation caused by wind. As the applcaition of this measuring method to the architectural acoustics, the meaurements of echo-time patterns, reverberation decays and sound pressure lev디 distributions in rooms and sound insulation efficiencies in buildings were carried out. From these experimental studies, it has been found that this M-sequence modulation correlation method is markedly useful especially for the field masurement of sound insulation under high back ground noise condition.

• Polymer(Korea)
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• v.24 no.5
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• pp.664-672
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• 2000

It is generally agreed that transesterification provides the, copolymer in the melt blending of poly(ethylene naphthalate) (PEN) and poly($\varepsilon$-caprolactone) (PCL). Effects of the conditions of transesterification reaction and catalyst on the degree of randomness and average sequence length of PEN/PCL blends were investigated and results were used to interpret the biodegradability of PEN/PCL blends. It was found that degree of randomness values of obtained copolymer lied between 0 and 1, and it indicated that this blend consisted with physical blends of PEN/PCL and PEN/PCL block copolymers. The degree of randomness reached almost 1 which is the theoretical value of random copolymers and the average sequence length became shorter by the further transesterification reaction. In additions, it was found that the increase of copolymers, especially random copolymers reduced the biodegradability in PEN/PCL blends.

• The KIPS Transactions:PartA
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• v.9A no.3
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• pp.387-398
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• 2002

As whole genome sequences of many organisms have been revealed by small-scale genome projects, the intensive research on individual genes and their functions has been performed. However on-memory algorithms are inefficient to analysis of whole genome sequences, since the size of individual whole genome is from several million base pairs to hundreds billion base pairs. In order to effectively manipulate the huge sequence data, it is necessary to use the indexed data structure for external memory. In this paper, we introduce a workbench system for analysis and visualization of whole genome sequence using string B-tree that is suitable for analysis of huge data. This system consists of two parts : analysis query part and visualization part. Query system supports various transactions such as sequence search, k-occurrence, and k-mer analysis. Visualization system helps biological scientist to easily understand whole structure and specificity by many kinds of visualization such as whole genome sequence, annotation, CGR (Chaos Game Representation), k-mer, and RWP (Random Walk Plot). One can find the relations among organisms, predict the genes in a genome, and research on the function of junk DNA using our workbench.