• Journal of Microbiology and Biotechnology
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• 제27권12호
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• pp.2089-2093
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• 2017

The past decades have been a golden era during which great tasks were accomplished in the field of microbiology, including food microbiology. In the past, culture-dependent methods have been the primary choice to investigate bacterial diversity. However, using culturein-dependent high-throughput sequencing of 16S rRNA genes has greatly facilitated studies exploring the microbial compositions and dynamics associated with health and diseases. These culture-independent DNA-based studies generate large-scale data sets that describe the microbial composition of a certain niche. Consequently, understanding microbial diversity becomes of greater importance when investigating the composition, function, and dynamics of the microbiota associated with health and diseases. Even though there is no general agreement on which diversity index is the best to use, diversity indices have been used to compare the diversity among samples and between treatments with controls. Tools such as the Shannon-Weaver index and Simpson index can be used to describe population diversity in samples. The purpose of this review is to explain the principles of diversity indices, such as Shannon-Weaver and Simpson, to aid general microbiologists in better understanding bacterial communities. In this review, important questions concerning microbial diversity are addressed. Information from this review should facilitate evidence-based strategies to explore microbial communities.

• Journal of Forest and Environmental Science
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• 제32권3호
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• pp.291-301
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• 2016

One of the most concerned topics in ecology is the relationship between biodiversity and ecosystem functioning. However, there are few field studies, carried out in forests, although many studies have been done in controlled experiments in grasslands. In this paper, we describe the relationship pattern between three facets of diversity and productivity at Ratargul Fresh Water Swamp Forest (RFWSF) in Bangladesh, which is the only remaining fresh water swamp forest of the country. Sixty sample plots were selected from RFWSF and included six functional traits including leaf area (LA), specific leaf area (SLA), leaf dry matter content (LDMC), tree height, bark thickness and wood density. In analyzing TD, we used Shannon diversity and richness indices, functional diversity was measured by Rao's quadratic entropy (Rao 1982) and Faith's (1992) index was used for phylogenetic diversity (PD). It was found that, TD, FD and PD were positively related with productivity (basal area) due to resource use complementarity but surprisingly the best predictor of tree productivity was FD. The results contribute to the understanding the effects of biodiversity loss and it is essential for conservation decision-making and policy-making of Ratargul Fresh Water Swamp Forest.

• Journal of Information Science Theory and Practice
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• 제7권3호
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• pp.31-39
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• 2019

Nowadays, recommender systems suggest lists of items to users considering not only accuracy but also diversity and novelty. However, suggesting the most diverse list of items to all users is not always acceptable, since different users prefer and/or tolerate different degree of diversity. Hence suggesting a personalized list with a diversity degree considering each user preference would improve the efficiency of recommender systems. The main contribution and novelty of this study is to tune the diversity degree of the recommendation list based on the users' variety-seeking feature, which ultimately leads to users' satisfaction. The proposed approach considers the similarity of users' desire diversity as a new parameter in addition to the usual similarity of users in the state-of-the-art collaborative filtering algorithm. Experimental results show that the proposed approach improves the personal diversity criterion comparing to the closest method in the literature, without decreasing accuracy.

• Journal of electromagnetic engineering and science
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• 제6권4호
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• pp.222-228
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• 2006

In this paper, the performance of a multiuser diversity system combined with a multi-element transmit antenna system is analyzed under the assumption of independent Rayleigh fading. A measure of system .level performance is an average channel capacity as a function of the number of users and antennas. Average channel capacity is obtained from the instantaneous signal-to-noise ratio(SNR) distribution combined by both transmit diversity(TD) at each link and multiuser diversity at system level. Numerical results show that closed-loop antenna techniques provide an additional gain with multiuser diversity system due to array gain, even though space diversity gain reduces multiuser diversity gain. On the other hand, the space-time block coding(STBC) that provides full order space diversity gain only has a destructive influence on multiuser diversity.

• Journal of Forest and Environmental Science
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• 제32권4호
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• pp.367-376
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• 2016

Urban greenery is an important component of urban environment and is fast gaining prominence especially in the developing countries. The destruction of urban trees has resulted to the degradation of the environment, thus the introduction of green Kumasi project by Kumasi Metropolitan Assembly, Ashanti Region of Ghana. The composition and diversity of urban trees gives rise to adequate management and monitoring, thus an inventory of urban trees of the Metropolis was conducted to document complete information on its density, diversity, composition and distribution. A total tree population of 1,101 was enumerated in the principal roads of the Metropolis. The ten most encountered tree species accounted for 61.04% of all the individual tree populations with Mangifera indica being dominant. The dominant families: Fabaceae, Moraceae and Arecaceae constitute 38.57% of the tree population. Diversity of the tree species was very high. The minimum diversity criteria were met on analysis of the diversity of this population. The proportion of exotic species was high with 65.71% of the trees belonging to the introduced species. It is recommended that greater emphasis should be placed on the planting of indigenous trees in future tree planting exercise.

• 한국문헌정보학회지
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• 제58권2호
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• pp.81-100
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• 2024

본 연구는 JCR에 등재된 문헌정보학 분야 국제학술지를 중심으로 학술지 편집위원과 저자의 국적 다양성을 분석하고 Simpson 다양성 지수(Simpson's Diversity Index)를 통해 계량화하였다. 더불어 편집위원 국적 다양성이 저자의 국적 다양성을 유도할 수 있는지 확인하고, 학술지의 특성에 따라 다양성 지수에 차이가 나타나는지 검증하였다. 분석 결과, 첫 번째, LIS 국제 학술지의 편집위원 국적 다양성 지수는 0.64로 0.76인 저자 국적 다양성에 미치지 못하는 것으로 나타났으며, 편집위원과 저자의 국적 다양성은 높은 상관계수를 보이는 것으로 확인되었다(r = 0.79). 두 번째, IS(Information Science) 분야 저널은 편집위원과 저자 기여국에서 모두 0.8 전후의 높은 다양성이 나타났으나 LS(Library Science) 분야는 상대적으로 저조하며 특히 편집위원 다양성에서 0.48의 낮은 지수가 나타났다. 세 번째, 미국은 저자와 편집위원 모두 가장 높은 점유율을 나타내고 있으며, 특히 LS 분야 편집위원에서 53.39%의 압도적 점유를 보이는 것으로 확인되었다. 반면 한국을 포함한 아시아 국가는 저자에 비해 편집위원으로서 기여하는 비율이 미국과 유럽 국가에 비해 낮은 것으로 나타났다.

• 한국전자파학회지:전자파기술
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• 제6권3호
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• pp.75-79
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• 1995

This paper derives the symbol error rate (SER) for quadrature amplitude modulation (QAM) with L-fold selection combining (SC) space diversity in Rayleigh fading channel. No analysis has been reported yet for theoretical SER performance of QAM with SC space diversity in Rayleigh fading channels. The formula is obtained by averaging the symbol error probability of M-ary QAM in an additive white Gaussian noise channel over the distribution of the maximum signal-to-noise ratio among all of the diversity channels. By giving the order of diversity, L, and the number of signal points, M, we have been able to obtain the SER performance of QAM with general SC space diversity. Analytical results show that the probability of error decreases with the order of diversity. We can also see that the incremental diversity gain per additional diversity decreases as the number of branches becomes larger.

• 산경연구논집
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• 제11권10호
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• pp.49-58
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• 2020

Purpose: The purpose of this study was to examine the differential effect of workforce diversity on employee productivity and its subsequent impact on customer experience. Research design, data and methodology: A once-off cross-sectional research design was used in this study where the Zimbabwean civil service was targeted. Randomization was used to collect 324 validated responses. The study focused on both primary (age and gender) and secondary (education and political affiliation) dimensions of workforce diversity. Results: The results were confirmatory that workforce diversity is a significant predictor of employee productivity (β = 0.668, P < 0.05), at the same time employee productivity holds explanation to customer experience by 37%. Results also revealed that gender diversity, educational diversity and political diversity were significant determinants of workforce diversity (P < 0.05). However, the study established that age diversity was not a significant factor in enhancing employee productivity (P > 0.05). Conclusions: The study concluded that workforce diversity is a powerful tool in enhancing both customer experience and employee productivity. As such, the latter can be augmented through shrewd workforce diversity practices as championed by management. To that end, the study recommends the development of a workforce diversity framework which promotes inclusivity.

• Asian-Australasian Journal of Animal Sciences
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• 제28권8호
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• pp.1066-1074
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• 2015

In contrast to high genetic diversity of mitochondrial DNA (mtDNA), equine Y chromosome shows extremely low variability, implying limited patrilines in the domesticated horse. In this study, we applied direct sequencing and restriction fragment length polymorphism (RFLP) methods to investigate the polymorphisms of 33 Y chromosome specific loci in 304 Chinese indigenous horses from 13 breeds. Consequently, two Y-single nucleotide polymorphisms (SNPs) (Y-45701/997 and Y-50869) and one Y-indel (Y-45288) were identified. Of those, the Y-50869 (T>A) revealed the highest variation frequency (24.67%), whereas it was only 3.29% and 1.97% in Y-45288 (T/-) and Y-45701/997 (G>T) locus, respectively. These three mutations accounted for 27.96% of the total samples and identified five Y-SNP haplotypes, demonstrating genetic diversity of Y chromosome in Chinese horses. In addition, all the five YSNP haplotypes were shared by different breeds. Among 13 horse breeds analyzed, Balikun horse displayed the highest nucleotide diversity (${\pi}=5.6{\times}10^{-4}$) and haplotype diversity (h = 0.527), while Ningqiang horse showed the lowest nucleotide diversity (${\pi}=0.00000$) and haplotype diversity (h = 0.000). The results also revealed that Chinese horses had a different polymorphic pattern of Y chromosome from European and American horses. In conclusion, Chinese horses revealed genetic diversity of Y chromosome, however more efforts should be made to better understand the domestication and paternal origin of Chinese indigenous horses.

• Journal of electromagnetic engineering and science
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• 제4권3호
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• pp.128-136
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• 2004

In this paper,. with the aim of achieving the expected performance improvement for a polarization diversity system, we analyzed two-branch polarization diversity at the receiving end of a mobile link which a transmitter emits circularly polarized wave. In this analysis, to calculate the correlation coefficient considered by XPD(cross polarization discrimination) between the two received signals, a simple theoretical model of circular polarization diversity is adopted. From the analysis results, it is clearly seen that the correlation coefficient of circular polarization diversity evaluated by the XPD is less than that of conventional linear polarization diversity. And also, we designed and implemented a circular polarization diversity system with micro-strip antenna. By using the circular polarization diversity system, we analyzed the measured data in indoor NLOS(Non-Line-Of-Sight) environments. From this analysis results, it is also clearly seen that the diversity effect of circular polarization diversity system shows better performance compared to the conventional linear diversity system by about 3 dB high.