• Title/Summary/Keyword: Selection Diversity

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Energy Savings in OFDM Systems through Cooperative Relaying

  • Khuong, Ho Van;Kong, Hyung-Yun
    • ETRI Journal
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    • v.29 no.1
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    • pp.27-35
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    • 2007
  • Energy savings in orthogonal frequency division multiplexing (OFDM) systems is an active research area. In order to achieve a solution, we propose a new cooperative relaying scheme operated on a per subcarrier basis. This scheme improves the bit error rate (BER) performance of the conventional signal-to-noise ratio (SNR)-based selection relaying scheme by substituting SNR with symbol error probability (SEP) to evaluate the received signal quality at the relay more reliably. Since the cooperative relaying provides spatial diversity gain for each subcarrier, thus statistically enhancing the reliability of subcarriers at the destination, the total number of lost subcarriers due to deep fading is reduced. In other words, cooperative relaying can alleviate error symbols in a codeword so that the error correction capability of forward error correction codes can be fully exploited to improve the BER performance (or save transmission energy at a target BER). Monte-Carlo simulations validate the proposed approach.

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The Empirical Analysis on the Performance of Inter-firm Network Management in the IT Service Firms (IT서비스 기업에서의 네트워크 경영 관련 성과 요인에 대한 실증 연구)

  • Ahn, Yeon S.
    • Journal of Information Technology Services
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    • v.10 no.1
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    • pp.47-64
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    • 2011
  • In the IT(Information Technology) service, which supply the solutions related to business management and IT, network construction and application trends, the related service business are increasing according to the enlargement of project scope and the diversity of project types as the need of service customers. In this paper, I propose the significant effect factors on the network management of IT service firms. The key findings are from the analysis result about 94 IT service firms as follows. For implementation the high performance of network management in the IT service firms, the strategic elements in the process of network construction are more conceived highly than the basic element in them. Also the perspective of project objectives are considered than the nominal perspectives in the partner selection process. The competency of partner firms', the cooperation process between the partner firms', network relation operation management and network relation structure management are the significant effect factors of network management.

Proposal for Listing the Korean Journal of Exercise Nutrition at SCIE Journal (한국운동영양학회지의 SCIE 등재를 위한 제언)

  • Kim, Chang-sun;Lim, Kiwon;Kwon, Tae-dong
    • Korean Journal of Exercise Nutrition
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    • v.14 no.2
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    • pp.57-61
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    • 2010
  • A journal listed by the Thompson Reuters for Scientific Citation Index Expended(SCIE) is important to be recognized internationally. There is no domestic journal related the exercise or sports discipline in spite of some domestic journals related other disciplines are recently listed in the SCIE. To be listed our Korean Journal of Exercise Nutrition(KJEN) on the SCIE, it is important to satisfy the criteria of SCIE. The criteria for journal evaluation and selection by Thompson Reuters include four main aspects. Evaluation of basic journal standards include timeliness of publication, international editorial conventions, bibliographic information in English and application of the peer review process. The editorial contents, international diversity and citation analysis are also evaluated. This study will propose the key points for listing the KJEN at SCIE journal.

Design of SSDT Cell ID Codes for W-CDMA System (W-CDMA 시스템의 SSDT 기지국 식별 부호 설계)

  • Song, Young-Joon
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.69-70
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    • 2007
  • The code division multiple access (CDMA) system capacity is limited by the amount of interference of the system. To reduce the unnecessary interference, this paper proposes optimized cell identification (ID) codes for site selection diversity transmission (SSDT) power control in wideband code division multiple access system of third generation partnership project (3GPP). The proposed SSDT cell ID codes are designed to minimize the problem and to be easily decoded using simple fast Hadamard transformation (FHT) decoder.

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Genetic diversity and divergence among Korean cattle breeds assessed using a BovineHD single-nucleotide polymorphism chip

  • Kim, Seungchang;Cheong, Hyun Sub;Shin, Hyoung Doo;Lee, Sung-Soo;Roh, Hee-Jong;Jeon, Da-Yeon;Cho, Chang-Yeon
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.11
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    • pp.1691-1699
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    • 2018
  • Objective: In Korea, there are three main cattle breeds, which are distinguished by coat color: Brown Hanwoo (BH), Brindle Hanwoo (BRH), and Jeju Black (JB). In this study, we sought to compare the genetic diversity and divergence among there Korean cattle breeds using a BovineHD chip genotyping array. Methods: Sample data were collected from 168 cattle in three populations of BH (48 cattle), BRH (96 cattle), and JB (24 cattle). The single-nucleotide polymorphism (SNP) genotyping was performed using the Illumina BovineHD SNP 777K Bead chip. Results: Heterozygosity, used as a measure of within-breed genetic diversity, was higher in BH (0.293) and BRH (0.296) than in JB (0.266). Linkage disequilibrium decay was more rapid in BH and BRH than in JB, reaching an average $r^2$ value of 0.2 before 26 kb in BH and BRH, whereas the corresponding value was reached before 32 kb in JB. Intra-population, interpopulation, and Fst analyses were used to identify candidate signatures of positive selection in the genome of a domestic Korean cattle population and 48, 11, and 11 loci were detected in the genomic region of the BRH breed, respectively. A Neighbor-Joining phylogenetic tree showed two main groups: a group comprising BH and BRH on one side and a group containing JB on the other. The runs of homozygosity analysis between Korean breeds indicated that the BRH and JB breeds have high inbreeding within breeds compared with BH. An analysis of differentiation based on a high-density SNP chip showed differences between Korean cattle breeds and the closeness of breeds corresponding to the geographic regions where they are evolving. Conclusion: Our results indicate that although the Korean cattle breeds have common features, they also show reliable breed diversity.

Cooperative Relaying with Interference Cancellation for Secondary Spectrum Access

  • Dai, Zeyang;Liu, Jian;Long, Keping
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.10
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    • pp.2455-2472
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    • 2012
  • Although underlay spectrum sharing has been shown as a promising technique to promote the spectrum utilization in cognitive radio networks (CRNs), it may suffer bad secondary performance due to the strict power constraints imposed at secondary systems and the interference from primary systems. In this paper, we propose a two-phase based cooperative transmission protocol with the interference cancellation (IC) and best-relay selection to improve the secondary performance in underlay models under stringent power constraints while ensuring the primary quality-of-service (QoS). In the proposed protocol, IC is employed at both the secondary relays and the secondary destination, where the IC-based best-relay selection and cooperative relaying schemes are well developed to reduce the interference from primary systems. The closed-form expression of secondary outage probability is derived for the proposed protocol over Rayleigh fading channels. Simulation results show that, with a guaranteed primary outage probability, the proposed protocol can achieve not only lower secondary outage probability but also higher secondary diversity order than the traditional underlay case.

Diet-Right: A Smart Food Recommendation System

  • Rehman, Faisal;Khalid, Osman;Haq, Nuhman ul;Khan, Atta ur Rehman;Bilal, Kashif;Madani, Sajjad A.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.6
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    • pp.2910-2925
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    • 2017
  • Inadequate and inappropriate intake of food is known to cause various health issues and diseases. Due to lack of concise information about healthy diet, people have to rely on medicines instead of taking preventive measures in food intake. Due to diversity in food components and large number of dietary sources, it is challenging to perform real-time selection of diet patterns that must fulfill one's nutrition needs. Particularly, selection of proper diet is critical for patients suffering from various diseases. In this article, we highlight the issue of selection of proper diet that must fulfill patients' nutrition requirements. To address this issue, we present a cloud based food recommendation system, called Diet-Right, for dietary recommendations based on users' pathological reports. The model uses ant colony algorithm to generate optimal food list and recommends suitable foods according to the values of pathological reports. Diet-Right can play a vital role in controlling various diseases. The experimental results show that compared to single node execution, the convergence time of parallel execution on cloud is approximately 12 times lower. Moreover, adequate accuracy is attainable by increasing the number of ants.

Exact and Approximate Symbol Error Probability of cooperative systems with best relay selection and all participating relaying using Amplify and Forward or Decode and Forward Relaying over Nakagami-m fading channels

  • Halima, Nadhir Ben;Boujemaa, Hatem
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.1
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    • pp.81-108
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    • 2018
  • In this paper, we derive the theoretical Symbol Error Probability (SEP) of cooperative systems with best relay selection for Nakagami-m fading channels. For Amplify and Forward (AF) relaying, the selected relay offers the best instantaneous Signal to Noise Ratio (SNR) of the relaying link (source-relay-destination). In cooperative networks using Decode and Forward (DF), the selected relay offers the best instantaneous SNR of the link between the relay and the destination among the relays that have correctly decoded the transmitted information by the source. In the second part of the paper, we derive the SEP when all participating AF and DF relaying is performed. In the last part of the paper, we extend our results to cognitive radio networks where there is interference constraints : only relays that generate interference to primary receiver lower than a predefined threshold T can transmit. Both AF and DF relaying with and without relay selection are considered.

The Effect of Sub-division (Two or Three Sub-populations) of a Population on Genetic Gain and Genetic Diversity

  • Oikawa, T.;Matsui, H.;Sato, K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.6
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    • pp.767-771
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    • 2002
  • Breeding efficiencies were compared among three population schemes: a single population, a population with two subpopulations and a population with three sub-populations. A simulation experiment of selection was carried out for 10 generations with 20 replications each by comparing average breeding values and inbreeding coefficients among the three population schemes. Phenotypes of three traits were generated with a model comprising 36 loci, each with additive genetic effects and residuals distributed normally. Among the three population schemes, the single population scheme was definitely superior to the other two with regards to selection response and inbreeding. The multiple sub-population scheme was, however, considered to be an alternative population scheme when the difference in economic weights of the traits was small among the sub-populations, assuming moderate inbreeding depression for traits and crossbreeding. The scheme with two sub-populations had a higher genetic value than that with three subpopulations; however, the genetic values of the schemes were comparable when maternal heterosis was taken into account. The choice of population schemes may depend on the cost-sharing policy between the breeding population and the commercial population rather than just the breeding efficiency.