• Title/Summary/Keyword: diversity methods

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Diversity of Cultured and Uncultured Bacteria in the Gut of Olive Flounder Paralichthys olivaceus (넙치(Paralichthys olivaceus) 장관의 배양 및 비배양 방법에 의한 세균의 다양성)

  • Kim, Ahran;Kim, Do-Hyung
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.48 no.4
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    • pp.447-453
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    • 2015
  • We determined the optimal culture conditions for obtaining the maximum number of intestinal bacteria from the olive flounder Paralichthys olivaceus, and studied bacterial diversity using both culture-dependent and culture-independent methods. Using six culture conditions, mean bacterial numbers were greater than $10^6$ per gram of gut mucus, regardless of the medium. However, the bacterial diversity, based on colony morphology, appeared much higher on Marine agar (MA) and Zobell 2216 agar than on other media. We found eight and 17 cultured bacterial phylotypes with 99% minimum similarity in gut mucus grown on MA and tryptic soy agar, respectively. Furthermore, we used genomic DNA extracted from gut mucus to generate 78 random clones, which were grouped into 25 phylotypes. Of these, six were affiliated with Firmicutes, Actinobacteria, and Verrucomicrobia, and were not found using our culture-dependent methods. Consequently, we believe that Marine agar and Zobell 2216 agar are optimal media for culturing diverse intestinal microbes; we also discovered several novel sequences not previously recognized as part of the gut microbiota of olive flounder.

On the Performance of Multicarrier CDMA Systems in Multipath Fading Channel (다중경로 페이딩 채널에서 멀티캐리어 코드분할다중접속 시스템 성능 분석)

  • Lee, Kwan-Houng;Lee, Myung-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.3
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    • pp.271-279
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    • 2006
  • This study proposes a new diversity algorithm to improve the signal-to-noise ratio. In the wireless channel, if fading occurs due to the multipaths, the performance of the system is apparently reduced. One of the methods to reduce fadings like this is the diversity method, and this study aims to improve the performance of the system by proposing a new diversity algorithm. This study applied rake receiver It applied QPSK and OQPSK modulation methods and applied the convolutional codes, where the code rate is 1/3 and the constraint length is 9, and the turbo code where the constraint length is 4. Under these conditions, this study compared and analyzed the average error probability of Multicarrier CDMA system.

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Effects of cultivation ages and modes on microbial diversity in the rhizosphere soil of Panax ginseng

  • Xiao, Chunping;Yang, Limin;Zhang, Lianxue;Liu, Cuijing;Han, Mei
    • Journal of Ginseng Research
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    • v.40 no.1
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    • pp.28-37
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    • 2016
  • Background: Panax ginseng cannot be cultivated on the same land consecutively for an extended period, and the underlying mechanism regarding microorganisms is still being explored. Methods: Polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) and BIO-LOG methods were used to evaluate the microbial genetic and functional diversity associated with the P. ginseng rhizosphere soil in various cultivation ages and modes. Results: The analysis of microbial diversity using PCR-DGGE showed that microbial communities were significantly variable in composition, of which six bacterial phyla and seven fungal classes were detected in P. ginseng soil. Among them, Proteobacteria and Hypocreales dominated. Fusarium oxysporum, a soilborne pathogen, was found in all P. ginseng soil samples except R0. The results from functional diversity suggested that the microbial metabolic diversity of fallow soil abandoned in 2003was the maximum and transplanted soil was higher than direct-seeding soil and the forest soil uncultivated P. ginseng, whereas the increase in cultivation ages in the same mode led to decreases in microbial diversity in P. ginseng soil. Carbohydrates, amino acids, and polymers were the main carbon sources utilized. Furthermore, the microbial diversity index and multivariate comparisons indicated that the augmentation of P. ginseng cultivation ages resulted in decreased bacterial diversity and increased fungal diversity, whereas microbial diversity was improved strikingly in transplanted soil and fallow soil abandoned for at least one decade. Conclusion: The key factors for discontinuous P. ginseng cultivation were the lack of balance in rhizosphere microbial communities and the outbreak of soilborne diseases caused by the accumulation of its root exudates.

Endophytic fungi harbored in Panax notoginseng: diversity and potential as biological control agents against host plant pathogens of root-rot disease

  • Zheng, You-Kun;Miao, Cui-Ping;Chen, Hua-Hong;Huang, Fang-Fang;Xia, Yu-Mei;Chen, You-Wei;Zhao, Li-Xing
    • Journal of Ginseng Research
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    • v.41 no.3
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    • pp.353-360
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    • 2017
  • Background: Endophytic fungi play an important role in balancing the ecosystem and boosting host growth. In the present study, we investigated the endophytic fungal diversity of healthy Panax notoginseng and evaluated its potential antimicrobial activity against five major phytopathogens causing root-rot of P. notoginseng. Methods: A culture-dependent technique, combining morphological and molecular methods, was used to analyze endophytic fungal diversity. A double-layer agar technique was used to challenge the phytopathogens of P. notoginseng. Results: A total of 89 fungi were obtained from the roots, stems, leaves, and seeds of P. notoginseng, and 41 isolates representing different morphotypes were selected for taxonomic characterization. The fungal isolates belonged to Ascomycota (96.6%) and Zygomycota (3.4%). All isolates were classified to 23 genera and an unknown taxon belonging to Sordariomycetes. The number of isolates obtained from different tissues ranged from 12 to 42 for leaves and roots, respectively. The selected endophytic fungal isolates were challenged by the root-rot pathogens Alternaria panax, Fusarium oxysporum, Fusarium solani, Phoma herbarum, and Mycocentrospora acerina. Twenty-six of the 41 isolates (63.4%) exhibited activity against at least one of the pathogens tested. Conclusion: Our results suggested that P. notoginseng harbors diversified endophytic fungi that would provide a basis for the identification of new bioactive compounds, and for effective biocontrol of notoginseng root rot.

Space Diversity Combining Scheme Using Phase Difference between Main and Diversity Signals (메인과 다이버시티 신호사이 위상차를 이용한 공간 다이버시티 결합방법)

  • Jung, Gillyoung
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.14 no.5
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    • pp.44-51
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    • 2015
  • The deployment of high capacity backhaul is required due to explosive growth in mobile data services. For rapid backhaul deployment, point to point microwave is a much easier and cheaper technology. The space diversity scheme is used in point to point microwave links. The purpose of space diversity is to overcome fading by combining signals from two separate receiver antennas. For signal combining algorithm, maximum power and minimum distortion methods were used and these algorithms were reported not to be good enough for robustness in selective fading. In this paper, a more practically efficient signal combining scheme from the main and diversity branch is proposed and evaluated in selective fading channel. The proposed algorithm has shown significant performance improvement in terms of signal spectrum.

Investigating the Effect of Both Team Diversity and Task Difficulty on Team Creativity : Multi-Agent Simulation Approach (팀 다양성과 과업난이도가 팀 창의성에 미치는 영향 : 다중 에이전트 시뮬레이션 접근방법을 중심으로)

  • Chae, Seong Wook;Seo, Young Wook;Lee, Kun Chang
    • Korean Management Science Review
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    • v.32 no.2
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    • pp.111-124
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    • 2015
  • In the management literature, it has been widely accepted among both researchers and practitioners that the level of team creativity is significantly related to the organizational performance. Besides, researchers posited with confidence that team diversity and task difficulty would affect team creativity through team members' activities of exploration and exploitation. However, empirical approaches to proving this belief suffered from lack of real data and proper methods as well. To tackle the research void like this, we propose a multi-agent simulation (MAS) mechanism. By adopting a set of parameters which validity were proven in the related literature, we conducted a series of experiments in the environment of the MAS platform named NetLogo. There sults suggest that managers can differentiate team diversity strategies according to task difficulty. In the case of a difficult task, managers need to increase team diversity so that their teams can maximize team creativity through rigorous exploration and exploitation. It is desirable to maintain an average level of team diversity when performing an easy task.

Diversity and its Characteristics of Life Phenomenon (생명현상의 다양성과 특징에 관한 고찰 - 보건의료에 미치는 영향을 중심으로 -)

  • Lee, Sun-Dong
    • Journal of Society of Preventive Korean Medicine
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    • v.14 no.1
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    • pp.1-12
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    • 2010
  • This research was intended to delve into the diversity of life phenomenon and its characteristics. First of all, this research gave real examples to compare the differences in men's health, disease, and longevity in order to confirm the existence of diversity of life phenomenon. In addition, it also studied the process and mechanism of manifestation of life phenomenon, as well as the influence and problems of existing studies' results and implications. The results are as follow. 1. Differences in health, diseases, and longevity were very big and diverse in researches on different races, nations, ages, socioeconomic status, positions, and even (monozygotic) twins. 2. The basic foundation of all organisms is DNA, and environmental factors change DNA methylation and the structure of chromatin by constantly influencing DNA. Due to this, the manifestation, control, and phenotype of DNA change, resulting in diversified life phenomenon. Therefore, it is the environmental factors, not DNA, that has more influence on the diversity of life. 3. Looking at available studies, the most reasonable perspective on human requires focusing on the diversity of life phenomenon, holistic thinking, and reversible change instead of irreversible determinism. Considerable differences in life phenomenon between entities require a change in malformed perspective on life. Public health and medicine deals with live human beings, a more precise and accurate perspective on life is very important. Because management methods of health and disease, such as structure and approaches of medical research, prevention and cure, must be different by life perspectives.

The Effects of Diversity Management in a Deluxe Hotel on F & B Employees' Job Engagement and Organizational Commitment (특급 호텔의 다양성 관리가 식음료 종사원의 직무열의 및 조직몰입에 미치는 영향)

  • Jung, Hyo Sun;Yoon, Hyo Sil;Yoon, Hye Hyun
    • Korean journal of food and cookery science
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    • v.32 no.3
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    • pp.363-369
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    • 2016
  • Purpose: The purpose of this study was to understand the interrelationships among diversity management, employees' job engagement, and organizational commitment in a deluxe hotel. Methods: In a total of 344 F & B employees obtained from empirical research, this study reviewed the reliability and fitness of the research model and verified a total of 4 hypotheses using the Amos program. Results: The proposed model provided an adequate fit to the data, $x^2$=316.722 (df=112), CMIN/df=2.828, GFI=0.899, NFI=0.941, IFI=0.961, TLI=0.953, CFI=0.961, RMSEA=0.073. SEM results showed that diversity management (building cultural awareness: ${\beta}$=0.206; pragmatic management policy; ${\beta}$=0.315) had a positive and significant influence on job engagement. Also, employees' job engagement (${\beta}$=0.623) had significant positive effects on organizational commitment. Conclusion: This study shows diversity management of hotel employees and its effectiveness as well as which diversity management is needed positive attitude.

Effects of feed intake on the diversity and population density of homoacetogens in the large intestine of pigs

  • Matsui, Hiroki;Mimura, Ayumi;Maekawa, Sakiko;Ban-Tokuda, Tomomi
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.12
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    • pp.1907-1913
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    • 2019
  • Objective: Homoacetogens play important roles in the production of acetate in the large intestine of monogastric mammals. However, their diversity in the porcine large intestine is still unknown. Marker gene analysis was performed to assess the effects of energy level on the diversity and population densities of homoacetogens in porcine feces. Methods: Crossbred pigs were fed high or low energy-level diets. The high-intake (HI) diet was sufficient to allow a daily gain of 1.2 kg. The low-intake (LI) diet provided 0.6 times the amount of energy as the HI diet. Genetic diversity was analyzed using formyltetrahydrofolate synthetase gene (FHS) clone libraries derived from fecal DNA samples. FHS DNA copy numbers were quantified using real-time polymerase chain reaction. Results: A wide variety of FHS sequences was recovered from animals in both treatments. No differences in FHS clone libraries between the HI and LI groups were found. During the experimental period, no significant differences in the proportion of FHS copy numbers were observed between the two treatment groups. Conclusion: This is the first reported molecular diversity analysis using specific homoacetogen marker genes from the large intestines of pigs. There was no observable effect of feed intake on acetogen diversity.

Performance improvement of long-range underwater acoustic communication in deep water using spatiotemporal diversity (심해 장거리 환경에서 시공간 다이버시티를 이용한 수중음향통신성능 향상)

  • Park, Heejin;Kim, Donghyeon;Kim, J.S.;Hahn, Joo Young;Park, Joung-Soo
    • The Journal of the Acoustical Society of Korea
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    • v.38 no.5
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    • pp.587-592
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    • 2019
  • ISI (Inter Symbol Interference) reduces the performance of UAComm (Underwater Acoustic Communication). This paper shows that the performance of UAComm can be improved through the spatiotemporal diversity method that is the combination of spatial diversity and temporal diversity methods. By using spatiotemporal diversity, the array aperture was reduced to increase the efficiency of the UAComm system. It is also verified using the experimental data of BLAC18 (Biomimetic Long range Acoustic Communication 18) conducted in October 2018.