• Journal of the Korea Society of Computer and Information
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• v.19 no.8
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• pp.55-62
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• 2014

A game theoretic approach is applied for studying the energy efficient rate scheduling. The individual utility function is defined first. Then, a non cooperative rate game is modeled in which each user decides the transmission rate to maximize its own utility. The utility function considered here is the consumed energy for the individual user's data transmissions. In particular, using the fact that the utility function is convex, we prove the existence of Nash Equilibrium in the energy efficient rate scheduling problem at hand. Accordingly, a non cooperative scheduling algorithm is provided. For better energy efficiency, the sum of the individual user's utility function is optimized Finally, the convergence analysis and numerical results to show the energy efficiency of the proposed algorithms are provided.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.4
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• pp.958-972
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• 2013

The purpose of this study is to analyze on high school teachers' stage of concern(SoC) on 'Creative-Experience Activity' in 2009 revised national curriculum and investigate the improvements of their levels. The subjects for this study were 234 high school teachers through out all part of the Korea country. The instrument for this study was developed according to the Hall & Hord(2006)'s stage of concerns questionnaire of Stage of Concern. The Data were analyzed by Profiling of teachers' concern and one-way ANOVA. The major findings of this study were as follows: First, 85.25% of the high school teachers were in stage of Awareness. 6.34% of teachers were in stage of Information. Most of high school teachers' concern about 'Creative-Experience Activity' was generally 'non-user' stage that unconcerned. Second, there were not significant differences in teachers' stage of concern according to their sex and teaching career except for region. In region, the teacher in metropolis tent to interest getting new information than small and midium size city. We need to make an effort to transfer from 'non-user' stage to 'early-user' stage of and 'impact' stage. To do so, we may sublate too much curriculum revise and start teacher training for 2009 revised 'creativity-experience activity' curriculum. The result of the study provide that there are not curriculum implementation success without teachers' concern about revised curriculum.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.11
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• pp.5392-5418
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• 2017

The primary aim of this paper is to propose a non-linear regression based technique for mapping different network Quality of Service (QoS) factors to an integrated end-user Quality of Experience (QoE) or Mean Opinion Score (MOS) value for an online video streaming service on a mobile phone. We use six network QoS factors for finding out the user QoE. The contribution of this paper is threefold. First, we investigate the impact of the network QoS factors on the perceived video quality. Next, we perform an individual mapping of the significant network QoS parameters obtained in stage 1 to the user QoE based upon a non-linear regression method. The optimal QoS to QoE mapping function is chosen based upon a decision variable. In the final stage, we evaluate the integrated QoE of the system by taking the combined effect of all the QoS factors considered. Extensive subjective tests comprising of over 50 people across a wide variety of video contents encoded with H.265/HEVC and VP9 codec have been conducted in order to gather the actual MOS data for the purpose of QoS to QoE mapping. Our proposed hybrid model has been validated against unseen data and reveals good prediction accuracy.

• International journal of advanced smart convergence
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• v.9 no.4
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• pp.34-41
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• 2020

Nowadays, the advanced smart convergences of the artificial intelligence (AI) and the internet of things (IoT) have been more and more important, in the fifth generation (5G) and beyond 5G (B5G) mobile communication. In 5G and B5G mobile networks, non-orthogonal multiple access (NOMA) has been extensively investigated as one of the most promising multiple access (MA) technologies. In this paper, we investigate the achievable data rate for the asymmetric binary pulse amplitude modulation (2PAM), in non-orthogonal multiple access (NOMA). First, we derive the closed-form expression for the achievable data rate of the asymmetric 2PAM NOMA. Then it is shown that the achievable data rate of the asymmetric 2PAM NOMA reduces for the stronger channel user over the entire range of power allocation, whereas the achievable data rate of the asymmetric 2PAM NOMA increases for the weaker channel user improves over the power allocation range less than 50%. We also show that the sum rate of the asymmetric 2PAM NOMA is larger than that of the conventional standard 2PAM NOMA, over the power allocation range larger than 25%. In result, the asymmetric 2PAM could be a promising modulation scheme for NOMA of 5G systems, with the proper power allocation.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.17-24
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• 2021

Recently, a lossless non-orthogonal multiple access (NOMA) implementation without successive interference cancellation (SIC) has been proposed in the literature of NOMA. This lossless non-SIC NOMA was achieved via correlated superposition coding (CSC), in contrast to conventional independent superposition coding (ISC). However, only the achievable data rates for CSC NOMA were investigated. Thus, this paper proposes a practical CSC NOMA scheme under Rayleigh fading channel environments. First, we design the practical CSC NOMA scheme, namely quadrature correlated superposition modulation (CSM) NOMA, without channel coding, i.e., uncoded systems. In addition, we calculate the symbol error rates (SERs) for this quadrature CSM NOMA scheme. Then, simulations demonstrate that for the weak channel gain's user, the SER performance of the proposed quadrature CSM NOMA is shown to be improved greatly, compared to that of the conventional quadrature amplitude modulation (QAM) NOMA, whereas for the strong channel gain's user, the SER performance of the proposed quadrature CSM NOMA degrades a little, compared to that of the conventional QAM NOMA. As a result, the proposed quadrature CSM NOMA scheme could be considered as a practical NOMA scheme for CSC NOMA schemes toward the fifth-generation (5G) and next generation communications.

• International Journal of Computer Science & Network Security
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• v.21 no.11
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• pp.257-265
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• 2021

Home networking and its security issues are directly related. Previous studies have shown that home-network and understanding the security of it is a problem for non-technical users. The existing network management tools or ISP adapter tools are far too technical and difficult to be understood by ordinary home-network users. Its interface is not non-technical user-directed and does not address the home user's needs in securing their network. This paper presents an interactive security monitoring tool, which emphasizes support features for home-network users. The tool combines an interactive visual appearance with a persuasive approach that supports sustainability. It is not only an easy-to-use tool for all categories of home-network users but also acts as a monitoring feature for the user to secure their home-network.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.4
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• pp.1351-1372
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• 2022

A self-organizing multiple unmanned aerial vehicles (multi-UAVs) deployment based on virtual forces has a difficulty in ensuring the quality-of-experience (QoE) of users because of the difference between the assumed center for users in a hotspot and an actual center for users in the hotspot. This discrepancy is aggravated in a non-uniform and mobile user distribution. To address this problem, we propose a new density based virtual force (D-VF) multi-UAVs deployment algorithm which employs a mean opinion score (MOS) as a metric of QoE. Because MOS is based on signal-to-noise ratio (SNR), a sum of users' MOS is a good metric not only to secure a wide service area but to enhance the link quality between multi-UAVs and users. The proposed algorithm improves users' QoE by combining virtual forces with a random search force for the exploration of finding multi-UAVs' positions which maximize the sum of users' MOS. In simulation results, the proposed deployment algorithm shows the convergence of the multi-UAVs into the position of maximizing MOS. Therefore, the proposed algorithm outperforms the conventional virtual force-based deployment scheme in terms of QoE for non-uniform user distribution scenarios.

• The Journal of the Acoustical Society of Korea
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• v.39 no.2
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• pp.131-136
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• 2020

Wake Up Word (WUW) is a short utterance used to convert speech recognizer to recognition mode. The WUW defined by the user who actually use the speech recognizer is called user-defined WUW. In this paper, to recognize user-defined WUW, we construct traditional Gaussian Mixture Model-Hidden Markov Model (GMM-HMM), Linear Discriminant Analysis (LDA)-GMM-HMM and LDA-Deep Neural Network (DNN)-HMM based system and compare their performances. Also, to improve recognition accuracy of the WUW system, a threshold method is applied to each model, which significantly reduces the error rate of the WUW recognition and the rejection failure rate of non-WUW simultaneously. For LDA-DNN-HMM system, when the WUW error rate is 9.84 %, the rejection failure rate of non-WUW is 0.0058 %, which is about 4.82 times lower than the LDA-GMM-HMM system. These results demonstrate that LDA-DNN-HMM model developed in this paper proves to be highly effective for constructing user-defined WUW recognition system.

• Spatial Information Research
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• v.10 no.1
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• pp.45-59
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• 2002

The author argues that the current Government Information System for river water quality appears to be non-user friendly due to lack of the cartographic representation for the field monitoring data. Acknowledging these constraints, an operational, user-friendly information system has been developed by combining Internet technology with GIS. A digital map for water quality has been generated by overlaying monitoring data on existing cartographic data such as road, topography and administrative boundary etc. A user interface was designed to address the need to querry the large spatial databases by non-GIS and non-environmental experts. The system has been checked experimentally and enabled the users to querry data required simply. And detailed visual maps for water quality can be generated over large areas quickly and easily. A visual mapping system for water quality was developed by reframing the monitoring data as graphic symbols and it was ideally suited to exploring area-wide water quality at a user-friendly manner due to extensibility and scalability along the various survey points. This system based on Web GIS could be accessed anywhere if internet is available. It would play a crucial role in improving the quality of public information service if it is operationally introduced into the Government since the highly user-friendly interface provides a completely new means for disseminating information far water pollution in a visual and interactive manner to the general public.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.348-353
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• 2008

This paper proposes a novel touch interface for recognizing user's touch pattern and understanding emotional information by eliciting natural user interaction. To classify physical touches, we represent the similarity between touches by analyzing touches based on its dictionary meaning and design the algorithm to recognize various touch patterns in real time. Finally we suggest the methodology to estimate user's emotional state based on touch.