• Title/Summary/Keyword: networks analysis

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An analysis of learning performance changes in spiking neural networks(SNN) (Spiking Neural Networks(SNN) 구조에서 뉴런의 개수와 학습량에 따른 학습 성능 변화 분석)

  • Kim, Yongjoo;Kim, Taeho
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.3
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    • pp.463-468
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    • 2020
  • Artificial intelligence researches are being applied and developed in various fields. In this paper, we build a neural network by using the method of implementing artificial intelligence in the form of spiking natural networks (SNN), the next-generation of artificial intelligence research, and analyze how the number of neurons in that neural networks affect the performance of the neural networks. We also analyze how the performance of neural networks changes while increasing the amount of neural network learning. The findings will help optimize SNN-based neural networks used in each field.

Patterns of Collaboration Networks:Co-authorship Analysis of MIS Quarterly from 1996 to 2004 (협력 네트워크 패턴에 관한 연구: MIS Quarterly 공저자 분석을 중심으로)

  • Huang, Ming-Hao;Ahn, Joong-Ho;Jahng, Jung-Joo
    • The Journal of Society for e-Business Studies
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    • v.13 no.4
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    • pp.193-207
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    • 2008
  • The study investigates the co-authorship networks of MIS Quarterly as one of the leading journals in IS field and examines patterns of collaboration networks of the intellectuals. These issues are addressed through a systematic Social Network Analysis (SNA) of 242 articles published from 1996 to 2004 in MIS Quarterly. Results of co-authorship network analysis indicate that the whole incomplete network has a low degree of density. Thus, we analyzed three biggest sub-networks to find out who the key players of each sub-network are. Then, following the keyword classification scheme, relevant data from the articles were collected and coded to analyze three major co-authorship networks of MIS Quarterly community. Some implications are drawn from different research keywords of each sub-network.

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Differences in Large-scale and Sliding-window-based Functional Networks of Reappraisal and Suppression

  • Jun, Suhnyoung;Lee, Seung-Koo;Han, Sanghoon
    • Science of Emotion and Sensibility
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    • v.21 no.3
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    • pp.83-102
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    • 2018
  • The process model of emotion regulation suggests that cognitive reappraisal and expressive suppression engage at different time points in the regulation process. Although multiple brain regions and networks have been identified for each strategy, no articles have explored changes in network characteristics or network connectivity over time. The present study examined (a) the whole-brain network and six other resting-state networks, (b) their modularity and global efficiency, which is an index of the efficiency of information exchange across the network, (c) the degree and betweenness centrality for 160 brain regions to identify the hub nodes with the most control over the entire network, and (d) the intra-network and inter-network functional connectivity (FC). Such investigations were performed using a traditional large-scale FC analysis and a relatively recent sliding window correlation analysis. The results showed that the right inferior orbitofrontal cortex was the hub region of the whole-brain network for both strategies. The present findings of temporally altering functional activity of the networks revealed that the default mode network (DMN) activated at the early stage of reappraisal, followed by the task-positive networks (cingulo-opercular network and fronto-parietal network), emotion-processing networks (the cerebellar network and DMN), and sensorimotor network (SMN) that activated at the early stage of suppression, followed by the greater recruitment of task-positive networks and their functional connection with the emotional response-related networks (SMN and occipital network). This is the first study that provides neuroimaging evidence supporting the process model of emotion regulation by revealing the temporally varying network efficiency and intra- and inter-network functional connections of reappraisal and suppression.

Connectivity Analysis of Cognitive Radio Ad-hoc Networks with Shadow Fading

  • Dung, Le The;An, Beongku
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.9
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    • pp.3335-3356
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    • 2015
  • In this paper, we analyze the connectivity of cognitive radio ad-hoc networks in a log-normal shadow fading environment. Considering secondary user and primary user's locations and primary user's active state are randomly distributed according to a homogeneous Poisson process and taking into account the spectrum sensing efficiency of secondary user, we derive mathematical models to investigate the connectivity of cognitive radio ad-hoc networks in three aspects and compare with the connectivity of ad-hoc networks. First, from the viewpoint of a secondary user, we study the communication probability of that secondary user. Second, we examine the possibility that two secondary users can establish a direct communication link between them. Finally, we extend to the case of finding the probability that two arbitrary secondary users can communicate via multi-hop path. We verify the correctness of our analytical approach by comparing with simulations. The numerical results show that in cognitive radio ad-hoc networks, high fading variance helps to remarkably improve connectivity behavior in the same condition of secondary user's density and primary user's average active rate. Furthermore, the impact of shadowing on wireless connection probability dominates that of primary user's average active rate. Finally, the spectrum sensing efficiency of secondary user significantly impacts the connectivity features. The analysis in this paper provides an efficient way for system designers to characterize and optimize the connectivity of cognitive radio ad-hoc networks in practical wireless environment.

Branding and Advertising on Social Networks: Current Trends

  • Trachuk, Tetiana;Vdovichena, Olga;Andriushchenko, Mariia;Semenda, Olha;Pashkevych, Maryna
    • International Journal of Computer Science & Network Security
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    • v.21 no.4
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    • pp.178-185
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    • 2021
  • The emergence of social networks has led to the flourishing of a new golden era of branding, which is a challenge for companies due to the need for creative positioning of companies with an emphasis on building trust and loyalty to the brand. Consumers are becoming more demanding and due to a wide range of products in different markets, make demands that are more stringent on companies. The goal of this article was to study the main trends of branding and advertising on social networks to develop a new approach to brand promotion. Methodology. The quantitative and qualitative research design was used to determine the main trends in branding and advertising on social networks. The methodology included the following methods: 1) analysis of the relationship between brand value and brand content strategy, 2) content analysis of the content of companies in social networks on the example of 10 world-famous brands with the highest value. The results allowed forming the criteria of effective content and communication: simplicity of content and simplicity of communication, lack of direct advertising of products, emphasis on global socio-economic problems and social orientation, unobtrusive communication, content creativity, indirect information about the product or work, the history of the company's development through various tools. The main content strategies of brands are defined: storytelling strategy; strategy of informing about the history of the company's development; entertainment and information strategy; strategy of joint interaction with the audience through the involvement of wellknown influencers or users of products. The theoretical and practical value of the results is confirmed by the conceptualization of the main content strategies of world-famous brands, which are pioneers in new ways to build relationships with users through social networks. The research proposes to use a customer-oriented approach to brand promotion. This means studying consumer behavior and predicting possible changes in behavior, which determines the level of interaction with the brand, the content strategy of the brand, and its effectiveness.

MIMO Ad Hoc Networks: Medium Access Control, Saturation Throughput, and Optimal Hop Distance

  • Hu, Ming;Zhang, Junshan
    • Journal of Communications and Networks
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    • v.6 no.4
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    • pp.317-330
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    • 2004
  • In this paper, we explore the utility of recently discovered multiple-antenna techniques (namely MIMO techniques) for medium access control (MAC) design and routing in mobile ad hoc networks. Specifically, we focus on ad hoc networks where the spatial diversity technique is used to combat fading and achieve robustness in the presence of user mobility. We first examine the impact of spatial diversity on the MAC design, and devise a MIMO MAC protocol accordingly. We then develop analytical methods to characterize the corresponding saturation throughput for MIMO multi-hop networks. Building on the throughout analysis, we study the impact of MIMO MAC on routing. We characterize the optimal hop distance that minimizes the end-to-end delay in a large network. For completeness, we also study MAC design using directional antennas for the case where the channel has a strong line of sight (LOS) component. Our results show that the spatial diversity technique and the directional antenna technique can enhance the performance of mobile ad hoc networks significantly.

Priority Based Interface Selection for Overlaying Heterogeneous Networks

  • Chowdhury, Mostafa Zaman;Jang, Yeong-Min
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.7B
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    • pp.1009-1017
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    • 2010
  • Offering of different attractive opportunities by different wireless technologies trends the convergence of heterogeneous networks for the future wireless communication system. To make a seamless handover among the heterogeneous networks, the optimization of the power consumption, and optimal selection of interface are the challenging issues. The access of multi interfaces simultaneously reduces the handover latency and data loss in heterogeneous handover. The mobile node (MN) maintains one interface connection while other interface is used for handover process. However, it causes much battery power consumption. In this paper we propose an efficient interface selection scheme including interface selection algorithms, interface selection procedures considering battery power consumption and user mobility with other existing parameters for overlaying networks. We also propose a priority based network selection scheme according to the service types. MN‘s battery power level, provision of QoS/QoE and our proposed priority parameters are considered as more important parameters for our interface selection algorithm. The performances of the proposed scheme are verified using numerical analysis.

Performance Analysis of Dynamic Spectrum Allocation in Heterogeneous Wireless Networks

  • Ha, Jeoung-Lak;Kim, Jin-Up;Kim, Sang-Ha
    • ETRI Journal
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    • v.32 no.2
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    • pp.292-301
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    • 2010
  • Increasing convergence among heterogeneous radio networks is expected to be a key feature of future ubiquitous services. The convergence of radio networks in combination with dynamic spectrum allocation (DSA) could be a beneficial means to solve the growing demand for radio spectrum. DSA might enhance the spectrum utilization of involved radio networks to comply with user requirements for high-quality multimedia services. This paper proposes a simple spectrum allocation algorithm and presents an analytical model of dynamic spectrum resource allocation between two networks using a 4-D Markov chain. We argue that there may exist a break-even point for choosing whether or not to adopt DSA in a system. We point out certain circumstances where DSA is not a viable alternative. We also discuss the performance of DSA against the degree of resource sharing using the proposed analytical model and simulations. The presented analytical model is not restricted to DSA, and can be applied to a general resource sharing study.

Pan Evaporation Analysis using Nonlinear Disaggregation Model (비선형 분리모형에 의한 증발접시 증발량의 해석)

  • Kim, Seong-Won;Kim, Jeong-Heon;Park, Gi-Beom
    • Proceedings of the Korea Water Resources Association Conference
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    • 2008.05a
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    • pp.1147-1150
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    • 2008
  • The goal of this research is to apply the neural networks models for the disaggregation of the pan evaporation (PE) data, Republic of Korea. The neural networks models consist of the support vector machines neural networks model (SVM-NNM) and multilayer perceptron neural networks model (MLP-NNM), respectively. The SVM-NNM in time series modeling is relatively new and it is more problematic in comparison with classifications. In this study, The disaggregation means that the yearly PE data divides into the monthly PE data. And, for the performances of the neural networks models, they are composed of training, cross validation, and testing data, respectively. From this research, we evaluate the impact of the SVM-NNM and the MLP-NNM for the disaggregation of the nonlinear time series data. We should, furthermore, construct the credible data of the monthly PE data from the disaggregation of the yearly PE data, and can suggest the methodology for the irrigation and drainage networks system.

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Single Relay Selection for Bidirectional Cooperative Networks with Physical-Layer Network Coding

  • Liu, Yingting;Zhang, Hailin;Hui, Leifang;Liu, Quanyang;Lu, Xiaofeng
    • ETRI Journal
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    • v.34 no.1
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    • pp.102-105
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    • 2012
  • To serve the growing demand of the bidirectional information exchange, we propose a single relay selection (RS) scheme for physical-layer network coding (PNC) in a bidirectional cooperative network consisting of two sources and multiple relays. This RS scheme selects a single best relay by maximizing the bottleneck of the capacity region of both information flows in the bidirectional network. We show that the proposed RS rule minimizes the outage probability and that it can be used as a performance benchmark for any RS rules with PNC. We derive a closed-form exact expression of the outage probability for the proposed RS rule and show that it achieves full diversity gain. Finally, numerical results demonstrate the validity of our analysis.