• Journal of IKEEE
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• v.11 no.1 s.20
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• pp.30-37
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• 2007

This paper proposes a detection method of position of OFF-switch. Each switch has the parallel path with a serial combination of passive element, its parallel path has each different frequency characteristics. Frequency characteristic of ON-switch reveals a flat spectrum irrelevant to frequency characteristic of passive element connected in parallel to its each terminal and frequency characteristic of OFF-switch reveals the same characteristic as one of passive element connected in parallel. Detection of position of OFF-switch is done by measuring the similarity of each spectrum corresponding to frequency characteristic of passive element connected in parallel to OFF-switch. The measure of their similarity is to calculate Euclidean distance between their test spectrum and reference spectrum. The spectrum with the smallest distance among reference spectrum is recognized as the spectrum of OFF-switch. The real time digital signal processing system is implemented to detect the position of OFF-switch by using spectrum matching.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.9
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• pp.885-892
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• 2016

The nonlinear sequence generator called the shrinking generator was designed as nonlinear keystream generator composed by two maximum-length LFSRs. The shrunken sequences generated by the shrinking generator are included in the class of interleaved sequences and can be modelled as one of the output sequences of cellular automata (CA). In this paper, we propose a method for synthesizing a 90/150 CA-based sequence generator to generate a family of sequences with the same characteristic polynomial as the shrunken sequences.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.9
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• pp.841-850
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• 2008

Strength and failure of composite-to-aluminum rivetted, bonded, and rivet/bonding hybrid single-lap joints were investigated by experiment. A total of 82 joint specimens were tested with 3 different overlap lengths and 2 types of stacking sequence. FM73m adhesive film and NAS9308-4-03 rivet were used for hybrid joints. While failure loads of the bonded and hybrid joints increased as the overlap length increased, failure loads of the rivetted joints were not affected by the overlap length. Effect of the stacking sequence was not remarkable in the simple bonded or rivetted joints. Failure loads of the hybrid joints, however, showed the maximum of 30% difference depending on the stacking sequence. Major failure mode of the bonded and hybrid joints was the delamination of the composite adherend and failure mode of riveted joints was the rivet failure with local bearing.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3C
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• pp.77-82
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• 2005

Partial response maximum likelihood (PRML) detection using the Viterbi algorithm involves the calculation of likelihood metrics that determine the most likely sequence of decoded data. In general, it is assumed that branches at each node in the trellis diagram have same probabilities. If modulation code with minimum and maximum run-length constraints is used, the occurrence ratio (Ro) of each particular pattern is different, and therefore the assumption is not true. We present a calculation scheme of the likelihood metrics for the PRML detection using the occurrence ratio. In simulation, we have tested the two (1,7) run-length-limited codes and calculated the occurrence ratios as the orders of PR targets are changed. We can identify that the PRML detections using the occurrence ratio provide more than about 0.5dB gain compared to conventional PRML detections at 10/sup -5/ BER in high-density magnetic recording and optical recording channels.

• Parasites, Hosts and Diseases
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• v.34 no.2
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• pp.127-134
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• 1996

Twelve isolates of Accnthamoebc app. assigned to either A. castellanii or A. poIMphoSa, and type strains of A. culbefsoni, A. henIWi, A. pqkestinefiE, and A. astronyxi,s were examined by restriction fragment length polymorphism (RFLP) of a conserved region of small subunit ribosomal RMh gene (ssu rDNA) amplified by polymerase chain reaction (PCR). The PCR products of the isolates measured approximately 910-930 bp, except for that of A. astronyxis which was extraordinarily long, approximately 1,170 bp. Average of estimated sequence divergence of the amplified DNA among the isolates assigned to A. castellanii was 9.8% whereas that among the isolates assigned to A. polvphusn 9.6%. The maximum intraspecific sequence divergence among the isolates assigned to A. costellanii was observed between the Chang and Ma strains (17.3%) while that among the isolates assigned to A. poIWphosa was observed between KA/S3 and KA/S7 strains (16.1%). The both maximum sequence divergences were much greater than the minimum interspecific sequence divergence between A. cnstellnnii and A. polwphasa (2.6%) which appeared between the Castellani (or CCAP 1501/12 g) and KA/S3 strains. The PCR-RFLP patterns of A. culbertsoni, A. healyi, A. palestinensis, and A. ostronvxis were quite diverse from one another and from those of isolates assigned to either A. castellanii or A. polyphoga. It is suggested that taxonomic validity of the isolates assigned to either A. castellnnii or A. polyphoga should be reevaluated.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.5
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• pp.873-880
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• 2020

The proposed encryption algorithm strengthens its security by converting pixel-specific values and changing pixel positions. The state transition matrix created by Wolfram's rule creates a complemented CA sequence with the maximum length. Then, we convert the sequence into a 2D basis image and go through a XOR operation with the original image. The final encrypted image is created by shear stressing and rearranging. The image stability analysis verified that the proposed encryption method has high security.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.4
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• pp.404-414
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• 2016

So called quaternary quasi-orthogonal sequence spatial modulation (Q-QOS-SM) has been presented with an advantage of improved throughputs compared to the conventional SM and generalized spatial modulation (GSM) by virtue of a larger set size of QOSs and its minimized correlation value between these QOSs. However the Q-QOS-SM has been originally invented for limited transmit antennas of only powers of two. In this paper, by extending the Q-QOS-SM to any number of transmit antennas, we propose a generalized Q-QOS-SM, referred as G-QO-SM. Unlike the conventional Q-QOS-SM using the Q-QOSs of length of any power of two, the proposed G-QO-SM is constructed based on the Q-QOSs of only the lengths of 2 and 4. The proposed scheme guarantees the transmission of the total $N_t$ spatial bits with $N_t$ transmit antennas, and thus achieves greatly higher throughputs than the other existing schemes including the SM, GSM, Q-QOS-SM, Quadrature-SM, and Enhanced-SM. The performance improvements of the proposed G-QO-SM is justified by comparing the analytically derived BER upper bounds and also the exact Monte Carlo simulation results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.83-86
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• 2007

In the blind Maximum-likelihood (ML) detection for Orthogonal Space-Time Block Codes (OSTBC), the problem of ambiguity in determining the symbols has been a great concern. A solution to this problem is to apply semi-blind ML detection, i.e., the blind ML decoding with pilot symbols or training sequence. In order to increase the performance, the number of pilot symbols or length of training sequence should be increased. Unfortunately, this leads to a significant decrease in system spectral efficiency. This work presents an approach to resolve the aforementioned issue by introducing a new method for constructing transmitted information symbol. Thus, by transmitting information symbols drawn from different modulation constellation, the ambiguity can be easily eliminated in blind detection. Also, computer simulations are implemented to verify the performance of the proposed approach.

• Journal of information and communication convergence engineering
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• v.6 no.2
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• pp.150-153
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• 2008

In the blind Maximum-likelihood (ML) detection for Orthogonal Space-Time Block Codes (OSTBC), the problem of ambiguity in determining the symbols has been a great concern. A possible solution to this problem is to apply semi-blind ML detection, i.e. the blind ML decoding with pilot symbols or training sequence. In order to increase the performance, the number of pilot symbols or length of training sequence should be increased. Unfortunately, this leads to a significantly decrease in system spectral efficiency. This work presents an approach to resolve the aforementioned issue by introducing a new method for constructing transmitted information symbols, in which transmitting information symbols drawn form different modulation constellations. Therefore, the ambiguity can be easily eliminated. In addition, computer simulation is implemented to verify the performance of the proposed approach.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.4
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• pp.637-645
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• 2015

Recently, a spatial modulation (SM) scheme achieving high throughput based on quaternary quasi-orthogonal sequences (Q-QOSs), referred to as Q-QOS-SM, is presented for $N_t=2^n(n=1,2,{\cdots})$ transmit antennas. In this paper, based on the design approach of the conventional Q-QOS-SM, new improved QO-SM (I-QO-SM) schemes are proposed for 8 transmit antennas. The new schemes employ Q-QOSs of length 4 or 2 unlike of 8 in the original one, which guarantees more information bits to be allocated for antenna index parts compared to the conventional Q-QOS-SM. By computer simulation results, the proposed scheme are shown to enjoy much higher throughputs compared to the conventional other SM schemes for all simulation environments. Finally, we also examine and compare analytically the performances of the new and conventional SM schemes by calculating upper-bounds on BER performance.