• Title/Summary/Keyword: diversity analysis

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Inventory of Street Tree Population and Diversity in the Kumasi Metropolis, Ghana

  • Uka, Ufere N.;Belford, Ebenezer J.D.
    • Journal of Forest and Environmental Science
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    • v.32 no.4
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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.

Analysis of Parameters for Polarization Diversity Scheme in Microcell (마이크로셀 환경에서 편파 다이버시티 기법 적용을 위한 파라미터 분석)

  • 이영수;홍순학;석우찬;윤영중
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.3
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    • pp.403-409
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    • 2000
  • In this paper, we measured and analyzed cross polarization discrimination(XPD), signal correlation coefficient($\rho$) and received signal level decrease, for the application of polarization diversity scheme in the up-link of microcell environments. We experimented in a dense building area, a dense residence area, a market area, a school area and etc at 1.9 GHz. Cross polarization discrimination (XPD) is about 6~11 dB, signal correlation coefficient($\rho$) is below 0.7 and received signal level decrease is smaller than 3 dB. The results of comparing polarization diversity with space diversity show that polarization diversity gain is about 2~5 dB higher in the various area. As a results, polarization diversity scheme is more effective than space diversity scheme in microcell environments.

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Multi-Relay Cooperative Diversity Protocol with Improved Spectral Efficiency

  • Asaduzzaman, Asaduzzaman;Kong, Hyung-Yun
    • Journal of Communications and Networks
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    • v.13 no.3
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    • pp.240-249
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    • 2011
  • Cooperative diversity protocols have attracted a great deal of attention since they are thought to be capable of providing diversity multiplexing tradeoff among single antenna wireless devices. In the high signal-to-noise ratio (SNR) region, cooperation is rarely required; hence, the spectral efficiency of the cooperative protocol can be improved by applying a proper cooperation selection technique. In this paper, we present a simple "cooperation selection" technique based on instantaneous channel measurement to improve the spectral efficiency of cooperative protocols. We show that the same instantaneous channel measurement can also be used for relay selection. In this paper two protocols are proposed-proactive and reactive; the selection of one of these protocols depends on whether the decision of cooperation selection is made before or after the transmission of the source. These protocols can successfully select cooperation along with the best relay from a set of available M relays. If the instantaneous source-to-destination channel is strong enough to support the system requirements, then the source simply transmits to the destination as a noncooperative direct transmission; otherwise, a cooperative transmission with the help of the selected best relay is chosen by the system. Analysis and simulation results show that these protocols can achieve higher order diversity with improved spectral efficiency, i.e., a higher diversity-multiplexing tradeoff in a slow-fading environment.

Performance Analysis of the Open Loop Transmitter and Receiver Diversity in the Wide Band CDMA network (광대역 부호분할다원접속(WCDMA) 이동통신 환경하에서 송수신 다이버시티 기법의 성능 분석)

  • Park Sang-Jo;Roh Yong-Woo
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.2 s.40
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    • pp.201-211
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    • 2006
  • The standardization of third Generation Partnership Project(3GPP) has been performed in of order to support interactive multimedia services under mobile environments. In this 3GPP, transmit diversity solutions are applied to increase the available diversity effectively using 2 or more antennas. In this paper, we analyzer the performances on STTD(Space Time Transmit Diversity) technique and its modified techniques such as STTD-OTD, CL-STTD, and 4TX-STTD out of open loop transmit diversities that the standardization of 3GPP has released. We also propose the open loop transmitter and receiver diversities to add the receiver diversity. We analyze and discuss the performance of the proposed techniques and using the Matlab simulation under the flat fading channel environment.

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Study of Menu Variety in Military Foodservice (군 급식에서의 메뉴 다양성에 관한 연구)

  • Yeo, Woon-Seung
    • Culinary science and hospitality research
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    • v.10 no.1
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    • pp.140-152
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    • 2004
  • This study investigates and analyzes the diversity of menu in military meal services that are recognized by the soldiers who are familar with meal services, and suggests the implications on the results of the analysis. For the ranks of respondents in terms of demographic features, the sergeants and corporals were 43.2%(186) and 29.7%(128) apiece. It was identified that the diversity of menu and significant influences as 57.5%. Thus, it is necessary to diversity the menus more than the present menus to increase the satisfaction of new generation on military meal services. The most influential factor on the diversity of menu was the hard-boiled food as 29.9% among 15 items. Therefore, the first measure to intensify the satisfaction of soldiers on meal services is to diversity the hard-boiled food. Accordingly, this measure will contribute to relieve the most biggest complaints on the diversity of menu in military meal services. For this purpose, it is recommended to replace the kitchen work system consisted of kitchen polices with the non-officer system enabling the long-term service. The kitchen polices are transferred to the first reserve list when they are accustomed to their duties because the period of service is limited under the present kitchen police system. Therefore, the present kitchen police system has the problem that it can't overcome the limit in terms of the quality of meal service.

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Analysis of Phase Noise Effects in OFDM Transmit Diversity Systems (OFDM 송신 다이버시티 시스템에서의 위상잡음 영향 분석)

  • Lee, Jong-Gil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.2
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    • pp.243-249
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    • 2006
  • In this paper, the phase noise effects of OFDM transmission diversity systems were analyzed. Since OFDM communication system is very sensitive to phase noise, the system performance may degrade seriously due to the increase of subcarrier interferences and system noise. Therefore, The phase noise model was suggested and its distribution and power were varied to investigate the effects of phase noise on the system performance. The degree of the system performance degradation depends on the specific diversity structures of transmission systems. Here, the performances of OFDM systems with two and three antennas transmission diversity were analyzed and compared with that of systems without transmission diversity as the phase noise characteristics varied.

Error Rate Performance of Convolution coded DS-CDMA 16 QAM signal in Diversity Reception in Rician Fading Environments (라이시안 페이딩 환경에서 길쌈 부호화된 DS-CDMA 16 QAM 신호의 다이버시티 수신에 대한 성능 해석)

  • 김세준;송찬호;김언곤
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2004.05b
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    • pp.190-195
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    • 2004
  • In this paper, Error rate performance of Convolution coded DS-CDMA 16 QAM signal is analyzed using selective combining diversity reception techniques and maximal ratio combining diversity reception techniques under the environments of Rician fading. With the results of analysis, maximal ratio combining diversity reception techniques provides the performance improvement of about 3-8[㏈] over selective combining diversity reception techniques for the good error performance lot data communication. And it is found that a synergistic performance improvement is show to both diversity reception and Convolution coding, techniques overcoming mobile wireless data communication channel environment.

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Analysis of Phase Noise Effects in OFDM Systems Using Transceiver Diversity (송수신 다이버시티를 적용한 다중 반송파 시스템에서의 위상잡음 영향 분석)

  • Lee, Jong-Gil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.2
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    • pp.280-286
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    • 2007
  • In this paper, the phase noise effects of OFDM transceiver diversity systems were analyzed. Since OFDM communication system is very sensitive to phase noise, the system performance may degrade seriously due to the increase of subcarrier interferences and system noise. Therefore, the phase noise model was suggested and its distribution and power were varied to investigate the effects of phase noise on the system performance. The degree of the system performance degradation depends on the specific diversity structures of transceiver systems. Here, the performances of OFDM systems with two antennas transceiver diversity were analyzed and compared with that of systems with only transmission diversity and without diversity as the phase noise characteristics varied.

A comparative study between countries on gender diversity, openness and innovation

  • JOLCHUBEKOVA, Jyldyz;KIM, Jae-Jin
    • East Asian Journal of Business Economics (EAJBE)
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    • v.10 no.1
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    • pp.123-136
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    • 2022
  • Purpose - Diversity subject is rising globally, as the proportion of women in the workforce increased to a large extent and the variety of resources became greater. Diversity attempts have appealed more awareness to the value of female participation in various areas, notably in the boardroom and corporate governance. This study tests the relationships among gender diversity, openness, and innovation, at the firm level across countries from the MOI Survey. Research design, data, and methodology - In this study the relationships among gender diversity, openness, and innovation were investigated at the firm level across countries from the Management, Organisation, and Innovation (MOI) Survey. A cross-cultural analysis was conducted based on the empirical evidence from six countries: Germany, India, Lithuania, Poland, Romania, and Russia. Result - The results show that gender diversity is positively related to innovation performance, moreover openness is positively associated with the level of firm innovation. In addition, a company's capability to use knowledge from outside and the creation of new combinations positively influence a firm's potential to innovate. Conclusion - This study suggests that the more gender-diverse top management team and the higher openness may bring the firm's innovation with greater possibility. the paper encourages more female participation on top management on the grounds of recommending that firms with greater gender diverse top management teams.

Some Universal Characteristics of Intertidal Bacterial Diversity as Revealed by 16S rRNA Gene-Based PCR Clone Analysis

  • Shuang, J.L.;Liu, C.H.;An, S.Q.;Xing, Y.;Zheng, G.Q.;Shen, Y.F.
    • Journal of Microbiology and Biotechnology
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    • v.16 no.12
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    • pp.1882-1889
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    • 2006
  • A 16S rDNA clone library was generated to investigate the bacterial diversity in intertidal sediment from the coast of the Yellow Sea, P. R. China. A total of 102 clones were sequenced and grouped into 73 OTUs using a phylogenetic approach. The sequenced clones fell into 11 bacterial lineages: Proteobacteria, Bacteroidetes, Planctomycetes, Chloroflexi, Acidobacteria, Actinobacteria, Firmicutes, Spirochaetes, and candidate divisions of BRCl, OP3, and OP1l. Based on a phylogenetic analysis of these bacteria, together with the ten most closely related sequences deposited in the GenBank, it was concluded that intertidal bacteria are most likely derived from marine bacteria with a remarkable diversity, and some are particularly abundant in intertidal sediment.