• 제목/요약/키워드: diversity methods

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

  • 김아란;김도형
    • 한국수산과학회지
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    • 제48권4호
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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.

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

  • 이관형;이명호
    • 한국컴퓨터정보학회논문지
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    • 제11권3호
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    • pp.271-279
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    • 2006
  • 본 논문에서는 신호대 잡음비를 향상시키는 새로운 다이버시티 알고리즘을 제안한다. 무선채널에서는 다중경로로 인하여 페이딩이 발생하여 시스템 성능이 감소한다. 페이딩을 감소시키는 방법중의 하나가 다이버시티기법이고, 새로운 다이버시티 기법을 제안하여 시스템 성능을 향상시키는 것이 본 논문의 목적이다. 수신기는 레이크수신기를 적용하였다. 변조방식은 QPSK, OQPSK을 적용하였고, 부호화율이 1/3이고, 구속장이 9인 길쌈부호와 구속장이 4인 터보코드를 적용하였다. 이와 같은 조건에서 본 논문은 다중캐리어 CDMA시스템에서 평균에러 확률을 비교 분석하였다.

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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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    • 제40권1호
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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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    • 제41권3호
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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.

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

  • 정길영
    • 한국ITS학회 논문지
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    • 제14권5호
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    • pp.44-51
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    • 2015
  • 모바일 데이터의 급속한 성장으로 인해 대용량의 백홀 구축 요구가 대두되었으며, 비용 효율 관점에서 쉽게 적은 비용을 가지고 백홀을 신속하게 구축할 수 있는 기술은 점대점 마이크로웨이브이다. 점대점 마이크로웨이브 링크에서의 공간 다이버시티 방법은, 두 개의 수신 안테나에서 오는 신호를 결합시킴으로 페이딩효과를 상쇄시켜 성능을 향상시키는 것이다. 기존의 신호 결합방법으로는 최대 전력 방법과 최소 왜곡 방법이 제안되었다. 하지만, 선택적 페이딩 채널에서 두 기법 모두가 알고리즘의 강건성 관점에서 성능저하가 보고되었다. 그래서, 본 논문에서 현실적 관점에서 효율적이며 더 성능이 향상된 신호결합 기법을 제안하고, 시뮬레이션을 통해 제안된 방법이 신호의 스펙트럼 관점에서 상당한 성능의 향상이 있음을 보인다.

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

  • 채성욱;서영욱;이건창
    • 경영과학
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    • 제32권2호
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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.

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

  • 이선동
    • 대한예방한의학회지
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    • 제14권1호
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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.

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

  • 정효선;윤효실;윤혜현
    • 한국식품조리과학회지
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    • 제32권3호
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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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    • 제32권12호
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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.

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

  • 박희진;김동현;김재수;한주영;박정수
    • 한국음향학회지
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    • 제38권5호
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    • pp.587-592
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    • 2019
  • 수중음향통신에서 다중경로로 인한 인접 심볼 간 간섭은 통신 성능을 저하시킨다. 인접 심볼 간 간섭의 영향을 최소화하여 수중음향통신 성능을 향상시키기 위해 다이버시티 기법을 사용한다. 본 논문에서는 공간 다이버시티와 시간 다이버시티의 결합을 통해 수중음향통신 성능이 개선됨을 보인다. 시공간 다이버시티를 통해 제한적인 배열에서 수중통신 시스템의 효율성을 증대시켰다. 또한 2018년 10월 한국의 동쪽 해역에서 수행한 BLAC18(Biomimetic Long range Acoustic Communication 18) 실험 데이터와 비교하여 이를 검증하였다.