• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.693-702
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• 2021

The aim of this study was to analyze the genetic diversity and distance of the Korean native black goat line. Thus far, this Korean native black goat line has not been studied intensively, especially in genetic diversity and relationship studies in comparison with other breeds. In total, eleven microsatellite (MS) markers were used to evaluate alleles from 391 Korean native black goats and foreign hybrid animals. The genetic diversity index was evaluated based on the allele distributions. Four Korean native black goat lines showed expected ranges of observed heterozygosity, expected heterozygosity, and polymorphism information content (PIC) values for use in genetic diversity research (0.509 - 0.643, 0.434 - 0.623 and 0.356 - 0.567). Lines from the Korean native black goat and foreign hybrid were clearly separated according to principal coordinates analysis (PCoA), phylogenetic tree and tended to be clustered in each Korean native black goat line. Thus, this study can be used for analyzing the genetic relationships between Korean native black goats and foreign breeds for line preservation and for fundamental information to determine breed improvement strategies.

• Journal of Information Technology Applications and Management
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• v.20 no.1
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• pp.149-171
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• 2013

The purpose of this study is to investigate factors influencing Chinese consumers' intention to adopt Smartphones. This paper examines Smartphone characteristics factors (situational dependence, diversity and security) and consumer personality characteristics (innovation, self-efficacy and familarity) based on the Technology Acceptance Model. The 320 sets of data are tested against the model using SEM (structural equation model). The research results reveal that diversity and security have significant influences on both perceived usefulness and perceived playfulness. According to the data analysis, self-efficacy affects only perceived easy of use, and familiarity positively affects perceived easy of use, usefulness and playfulness. This study finds that perceived easy of use and perceived usefulness have positive influences on behavioral intention to adopt Smartphones, and situational dependence and innovation directly affect the behavioral intention. The perceived cost has a negative impact on the behavioral intention. Research results are discussed, and limitations of the current study and future research are presented.

• Journal of Families and Better Life
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• v.33 no.6
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• pp.51-63
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• 2015

This study explored the effects of after-school services on whether they reduced the possibility of self-care of children. In terms of characteristics of the use of after-school services, it focused on the 1) types, 2) diversity, and 3) use patterns of the after-school services. For the analysis, it used data of the cohort of elementary-school children from the Korean Children and Youth Panel Survey. The main findings are as follows. First, private mentoring and after-school services provided by welfare centers reduced the possibility of self-care. Second, when the total amount of educational time was controlled, the diversity of participating after-school services did not explain the possibility of self-care. Third, when the total amount of educational time was controlled, the use patterns of after-school services did not explain the possibility of self-care. Based on these findings, it suggested policy implications and future research.

• Journal of Families and Better Life
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• v.33 no.3
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• pp.1-14
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• 2015

This study examined the effects of Dream Start participation on the use of after-school programs, considering its emphasis on the utilization of community resources. For this, it compared the use of after-school programs in terms of the number of types and the total amount of time between children who had been participating in Dream Start and those who had not. The main findings are as follows. First, when all other conditions were held constant, children in Dream Start used more types of after-school programs compared to their correspondents. Second, children in Dream Start were more likely to use two types of after-school programs over weekdays or three types of programs for several days a week compared to their correspondents. Third, children in Dream Start spent less amount of time in the after-school programs compared to their correspondents. Even though this study found the effectiveness of Dream Start as a facilitator of community resource utilization, future research needs to examine the effects of after-school program use in terms of its diversity and amount on the development of low-income children.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.7A
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• pp.751-756
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• 2008

In this paper, we propose a modified I/Q diversity scheme receiver of UHF RFID reader system. The modified I/Q diversity receiver is more robust than the conventional homodyne receiver in the wireless noisy, fading channel and phase noise environments by making use of additional axes. In particular, it is shown that the closer the phase difference ${\theta}(t)$ between the reader and the tag to ${\pi}/4$, the larger performance improvement we can get. The performance of the proposed receiver is verified by equations and is demonstrated by the computer simulation for various difference ${\theta}(t)$ cases.

• ETRI Journal
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• v.28 no.1
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• pp.87-90
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• 2006

In this letter, we propose a quasi-orthogonal space-time-frequency (QOSTF) block coded orthogonal frequency division multiplexing (OFDM) that can achieve full symbol rate with four transmit antennas. Since the proposed QOSTF-OFDM cannot achieve full diversity, we use a diversity advantage collection with zero forcing (DAC-ZF) decoder to compensate the diversity loss at the receiving side. Due to modulation advantage and collected diversity advantage, the proposed scheme exhibits a better bit-error rate performance than other orthogonal schemes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.3
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• pp.1156-1173
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• 2021

In this paper, we propose a new joint precoder and postcoder design strategy to support multiple streams per user in multiuser multiple-input multiple-output (MIMO) systems. We propose two step precoding strategies using equal channel gain decomposition and block diagonalization at the transmitter. With the proposed precoder, the multiuser MIMO channel can be decomposed into multiple parallel channels with equal channel gain per user. After applying receive postcoder which is generated and sent by the transmitter, we can use ML based decoder per stream to achieve full receive diversity. Achievable sum rate bound and diversity performance of the proposed algorithm are presented with feedback signaling design and quantitative complexity analysis. Simulation results show that the proposed algorithm asymptotically approaches to the sum rate capacity of the MIMO broadcast channel while maintaining full diversity order.

• Journal of Ecology and Environment
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• v.47 no.4
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• pp.177-186
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• 2023

Background: Inner Mongolia, desertification is happening due to climate change and land use alterations. In order to evaluate desert restoration effectiveness, this study compares number of species and species diversity in restored (with planted trees), unrestored area, and the reference ecosystem (Ref-E, typical steppe and woody steppe). Results: The Ref-E had the most plant species (64 taxa), while the unrestored area had the fewest (5 taxa). Among restored areas (restored in 2012, 2008, 2005), older restoration sites had more species (18-42). Similarly, species richness (3.93-0.41) and diversity (1.99-0.40) were highest in the Ref-E and lowest in unrestored areas, with older restored sites having higher values. Conclusions: More plant species and diversity in older restoration areas suggest progress toward ecosystem stabilization, approaching the Ref-E. Therefore, tree planting in Inner Mongolia's Hulunbuir semi-arid desert is a successful restoration effort.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.4 s.119
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• pp.440-447
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• 2007

The switched diversity, although its performance is a little inferior to the selection diversity, is widely used due to its advantage that only one RF circuit is required for its operation without respect to the number of antennas in use. In this paper, we propose an application of the antenna switched diversity to a spread spectrum system with adaptive modulation and derived the optimal antenna switching threshold to maximize the average transmission bit rate. We also compared the performances of the proposed system with those of the two cases using a single antenna and the selection diversity with two antennas in terms of the average number of bits per symbol(BPS), the probability of no transmission, and the average BER. The performance analysis shows that, if the number of paths in a multipath channel environment increases, the performance of the proposed scheme becomes closer to that of the selection diversity based system in terms of the average BPS. Furthermore, the proposed scheme produces as almost high the probability of no transmission as the selection diversity based system for the case of low average SNR, although the former yields a little higher probability of no transmission than the latter fer the case of high average SNR.

• Plant Resources
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• v.6 no.1
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• pp.16-26
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• 2003

Molecular markers are useful tools for evaluating genetic diversity and determining cultivar identity. Present study was conducted to evaluate the genetic diversity within a diverse collection of rice accessions used for Korean breeding programs. Two hundred eighty-seven rice cultivars, composed of temperate japonica, tropical japonica, indica, and Tongil-type of Korean crossing parents were evaluated by means of 15 simple sequence repeat (SSR) markers. A total of 99 alleles were detected, and the number of alleles per marker ranged from 4 to 11, with an average of 6.6 per locus. Polymorphism information content (PIC) for each of the SSR markers ranged from 0.2924 to 0.8102 with an average of 0.5785. These results, with the result that use of only 15 SSR markers made all rice cultivars examined could be uniquely distinguished, imply the efficiency of SSR markers for analysis of genetic diversity in rice. Cluster analysis was performed on similar coefficient matrics calculated from SSR markers to generate a dendogram in which two major groups corresponding to japonica (Group I) and indica and Tongil type rice (group II) with additional subclasses within both major groups. The narrowness of the Korean breeding germplasm was revealed by the fact that most of the Korean-bred and Japan-bred temperate japonica cultivars were concentrated into only 2 of the sub-group I-1 (143 cultivars) and I-2 (58 cultivars) among six sub-groups in major group of japonica. This is because of the japonica accessions used in this study was a very closely related ones because of frequent sharing of the crossing parents with similar genetic background with synergy effect of the inherited genetic difference between indica and japonica. A rice breeding strategy with the use of molecular markers was discussed for overcoming of genetic vulnerability owing to this genetic narrowness.