• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.643-646
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• 2006

The popularity of OFDM systems is being increased because of high speed data transmission capability and the spectral efficiency characteristics. However, since OFDM systems are very sensitive to the phase noise, The interference among subcarriers and the total system noise can be increased seriously due to the degree of phase noise effects which can cause the orthogonality problems. Therefore, these phase noise effects were analyzed using the phase noise model by varying its parameters. Especially in this paper, The degree of system performance degradation was investigated for the OFDM systems applying the relatively simple transmit and receiver diversity.

• Weed & Turfgrass Science
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• v.3 no.3
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• pp.190-195
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• 2014

Echinochloa (L.) P. Beauv. includes some of the noxious weeds, causing a serious yield loss when they are dominant in the fields. Identification of the Echinochloa is very difficult because many interspecific and intraspecific forms of the species are found. However, it is important to identify the species exactly and to know the genetic diversity of the species for effective weed management. This study was conducted to identify and summarize the Echinochloa species by comparing the genetic variation and relationship among Korean Echinochloa species using SSR. The genetic diversity of 107 individuals, including seven species were assessed using five SSR markers. UPGMA dendrogram generated two clades (I and II) and clade II divided again into two subclades (II-1 and II-2) whereas the model based genetic structure proposed four subpopulations. The two subpopulations were corresponded to clades I and II-1 and the other two were arranged to clade II-2 of the UPGMA dendrogram. We have concluded that E. colona and E. glabrescens might have not distributed in Korea. The biological varieties, praticola and echinata, of E. crus-galli should be treated as E. crus-galli. Korean Echinochloa should be summarized with four species, i.e., E. oryzicola, E. crus-galli, E. esculenta, and E. oryzoides.

• Animal Systematics, Evolution and Diversity
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• v.33 no.2
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• pp.140-143
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• 2017

A winged midge species, Parochlus steinenii is one of the most abundant species in Antarctica, which is distributed over a wide area from the South American continent to the South Shetland Islands in Antarctica. It was dispersed into islands in the South Shetland Islands from the South American continent, and it adapted to a variety of environments and settled. This species, therefore, is a good model organism to explain the evolutionary process of Antarctic terrestrial fauna. Nevertheless, there are few genetic studies on this species, which are necessary for understanding the genetic diversity, population structure, etc. Here, we developed and characterized 14 polymorphic microsatellite markers. The number of alleles per locus ranged from 2 to 5. The observed and expected heterozygosities were in the range of 0.024 to 0.561 and 0.024 to 0.535, respectively. Identifying genetic differences between populations, they are suitable markers for researches investigating genetic diversity and population structure of P. steinenii, which provide us with clues to dispersion, evolution and ecology of this species.

• The Journal of Information Systems
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• v.32 no.2
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• pp.63-85
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• 2023

Purpose According to a recent survey, more than 90% of customers make purchase or use decisions for their products and services, primarily based on word-of-mouth(WOM) information (reviews, recommendations, ratings, etc.). However, few studies have explored what factors influence user's WOM intention in the context of OTT service. To address this gap, this study investigates the antecedent factors of WOM intention by adopting stimulus-organism-response (SOR) theory and pleasure arousal dominance (PAD) theory as a theoretical basis. Design/methodology/approach The research model consists of stimulus factors (diversity of original content, aesthetics, interactivity, personalization quality), emotional factors (pleasure, excitement, dominance), and behavioral factor (WOM intention). The research hypothesis was tested using the survey data collected from OTT service users of 305. Findings The result reveals that diversity of original content significantly affects on pleasure and arousal whereas it is not associated with dominance. Findings indicate that aesthetics positively influences pleasure, and interactivity is not associated with arousal. It is also proven that personalization quality has a positive effect on dominance. In addition, pleasure, arousal, and domination are proven to be positively and significantly related to WOM intention.

• Proceedings of the Korean Society of Crop Science Conference
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• 2020.06a
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• pp.120-120
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• 2020

Based on the simple sequence repeat (SSR) marker, a Korean wheat core collection were established with 616 wheat accessions. Among them, the SNP genotyping for the entire genome was performed using DNA chip array to clarify the whole genome SNP profiles. Consequently, a total of 35,143 SNPs were found and we re-established a mini-core collection with 247 accessions. Population diversity and phylogenetic analysis revealed genetic diversity and relationships from the mini core set. In addition, genome-wide association study (GWAS) was performed on 19 phenotypic traits; ear type, awn length, culm length, ear length, awn color, seed coat color, culm color, ear color, loading, leaf length, leaf width, seeding stand, cold damage, weight, auricle, plant type, heading stage, maturation period, upright habit, and degree of flag leaf. The GWAS was performed using the fixed and random model circulating probability unification (FarmCPU), which identified 14 to 258 SNP loci related to 19 phenotypic traits. Our study indicates that this Korean wheat mini-core collection is a set of germplasm useful for basic and applied research with the aim of understanding and exploiting the genetic diversity of Korean wheat varieties.

• Journal of Mushroom
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• v.17 no.4
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• pp.171-178
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• 2019

Agaricus bisporus is a functional food and among the most widely cultivated mushrooms in the world. In this study, we analyzed the genetic diversity and population structure of 23 Korean and 42 foreign A. bisporus cultivars using SSR (Simple sequence repeat) markers. Genetic diversity of A. bisporus cultivars was as follows: number of alleles was approximately 13; observed and expected heterozygosity were approximately 0.59 and 0.74, respectively; and polymorphic information content value was about 0.71. A. bisporus cultivars were divided into three groups using distance-based analysis. Genetic diversity of Group 2, which consisted of cultivars from various countries, was high. In addition, model-based subpopulations were divided into two, and the genetic diversity of Pop2 (Population 2), which had many cultivars, was high. The results of this study could be used in a breeding program for A. bisporus, such as the development of new genetic resources and securing diversity.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.6
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• pp.99-105
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• 2010

The most frequently used noise model for the performance analysis of a communication system is additive white Gaussian noise. However impulsive noise model is more practical for the real communication environments, currently the performance analysis of a communication system in impulsive noise is increasing. In this paper, therefore, the performance of a cooperative system, which is recently one of the most intensive research topics, is derived in impulsive noise. We analytically derive and compare the performance of two opportunistic cooperative diversity systems which have an amplify-and-forward (AF) relaying or a decode-and-forward (DF) relaying. It is noticed that the impulsive noise component is increases with decreasing the average number of impulses in impulsive noise, consequently the performance of two systems is degraded in high SNR region. Also it is shown that the performance of the opportunistic cooperative system with DF relaying is superior to that with AF relaying.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.4
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• pp.441-451
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• 2009

In this study, 29 simple sequence repeat (SSR) markers were used to analyze the genetic diversity and population structure of 125 rice accessions from 40 different origins in Africa, Asia, Europe, South America, and Oceania. A total of 333 alleles were detected, with an average of 11.5 per locus. The mean values of major allele frequency, expected heterozygosity, and polymorphism information content (PIC) for each SSR locus were 0.39, 0.73, and 0.70, respectively. The highest mean PIC was 0.71 for Asia, followed by 0.66 for Africa, 0.59 for South America, 0.53 for Europe, and 0.47 for Oceania. Model-based structure analysis revealed the presence of five subpopulations, which was basically consistent with clustering based on genetic distance. Some accessions were clearly assigned to a single population in which >70% of their inferred ancestry was derived from one of the model-based populations. In addition, 12 accessions (9.6%) were categorized as having admixed ancestry. The results could be used to understanding the genetic structure of rice cultivars from these regions and to support effective breeding programs to broaden the genetic basis of rice varieties.

• Journal of Crop Science and Biotechnology
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• v.11 no.2
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• pp.83-90
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• 2008

Two hundred and sixty Korean soybean landrace accessions were analyzed for polymorphism at 92 simple sequence repeat(SSR) loci. The 995 identified alleles served as raw data for estimating genetic diversity and population structure. The number of alleles at a locus ranged from three to 27 with a mean of 10.4 alleles per locus. $F_{ST}$ values estimated by analysis of molecular variance(AMOVA) using SSR data set were 0.018, 0.027, and 0.016 for usage, collection site and maturity groups, respectively, indicating little genetic differentiation. The model-based clustering analysis placed the accessions into three clusters(K=3) with 0.0503 of $F_{ST}$, indicating moderate genetic differentiation. Duncan's Multiple Range Test at K = 3 on the basis of 18 quantitative traits revealed that one cluster was mainly differentiated from the other two clusters by seed related traits and the other two clusters were differentiated from each other by biochemical traits. Genetic structure of Korean soybean landraces was differentiated by model-based clustering and supported by their phenotypic traits in part. This preliminary study could be the first step towards more efficient germplasm management and utilization of soybean landraces and helpful in association studies between genotypic and phenotypic traits in Korean soybean landraces.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.12
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• pp.1696-1701
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• 2016

Japanese quail is still used as a model for poultry research because of their usefulness as laying, meat, and laboratory animals. Microsatellite markers are the most widely used molecular markers, due to their relative ease of scoring and high levels of polymorphism. The objective of the research was to determine genetic diversity and population genetic structures of selected Japanese quail lines (high body weight 1 [HBW1], HBW2, low body weight [LBW], and layer [L]) throughout 15th generations and an unselected control (C). A total of 69 individuals from five quail lines were genotyped by fifteen microsatellite markers. When analyzed profiles of the markers the observed ($H_o$) and expected ($H_e$) heterozygosity ranged from 0.04 (GUJ0027) to 0.64 (GUJ0087) and 0.21 (GUJ0027) to 0.84 (GUJ0037), respectively. Also, $H_o$ and $H_e$ were separated from 0.30 (L and LBW) to 0.33 (C and HBW2) and from 0.52 (HBW2) to 0.58 (L and LBW), respectively. The mean polymorphic information content (PIC) ranged from 0.46 (HBW2) to 0.52 (L). Approximately half of the markers were informative ($PIC{\geq}0.50$). Genetic distances were calculated from 0.09 (HBW1 and HBW2) to 0.33 (C and L). Phylogenetic dendrogram showed that the quail lines were clearly defined by the microsatellite markers used here. Bayesian model-based clustering supported the results from the phylogenetic tree. These results reflect that the set of studied markers can be used effectively to capture the magnitude of genetic variability in selected Japanese quail lines. Also, to identify markers and alleles which are specific to the divergence lines, further generations of selection are required.