• 대한음성학회지:말소리
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• 제58호
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• pp.101-117
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• 2006

The development of efficient multimodal interfaces and fusion algorithms requires knowledge of usage patterns that show how people use multiple modalities. We analyzed multimodal usage patterns for TV-guide application scenarios (or tasks). In order to collect usage patterns, we implemented a multimodal usage pattern collection system having two input modalities: speech and touch-gesture. Fifty-four subjects participated in our study. Analysis of the collected usage patterns shows a positive correlation between the task type and multimodal usage patterns. In addition, we analyzed the timing between speech-utterances and their corresponding touch-gestures that shows the touch-gesture occurring time interval relative to the duration of speech utterance. We believe that, for developing efficient multimodal fusion algorithms on an application, the multimodal usage pattern analysis for the given application, similar to our work for TV guide application, have to be done in advance.

• 디지털융복합연구
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• 제6권2호
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• pp.1-12
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• 2008

The spectrum usage fee has been imposed on spectrum users. The objective of the fee is spectrum management, so it is important to utilize it efficiently. Our study focused on how to efficiently utilize the spectrum usage fee. For this purpose it tried to found what the preconditions are for the efficient utilization, and analyzed current execution. The study showed that it did not comply with those preconditions, and produced policy recommendations. The authors expect that policy recommendations this study brought up will contribute to improve the policy process how to collect and use the spectrum usage fee.

• 한국IT서비스학회지
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• 제7권1호
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• pp.255-274
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• 2008

The purpose of this research is to develop an information technology (IT) usage level assessment model for service industry. It is necessary to develop an assessment model for service industry's IT usage to improve service productivity. However, it is not easy to develop assessment models due to service industry's diversity. In this paper a generic IT usage assessment model for service industry has been developed and validated through a descriptive approach. Key factors affecting service productivity have been identified and analysed. A pilot test on IT usage level has been performed to investigate the relevance and importance of IT usage indicators (factors). As a result, a set of effective IT usage indicators for service industry have been found. A short-cut model and a full scale model have been proposed for efficient and effective usage. The results of this study can be used for enhancement of service industry productivity through the increase of IT usage level.

• 전기학회논문지
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• 제65권1호
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• pp.16-22
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• 2016

This paper addresses the load usage scheduling in the HEMS for residential power consumers. The HEMS would lead the residential users to change their power usage, so as to minimize the cost in response to external information such as a time-varying electricity price, the outside temperature. However, there may be a consumer's inconvenience in the change of the power usage. In order to improve this, it is required to understand the pattern of load usage according to the external information. Therefore, this paper suggests a methodology to model the load usage pattern, which classifies home appliances according to external information affecting the load usage and models the usage pattern for each appliance based on a copula function representing the correlation between variables. The modeled pattern would be reflected as a constraint condition for an optimal load usage scheduling problem in HEMS. To explain an application of the methodology, a case study is performed on an electrical water heater (EWH) and an optimal load usage scheduling for EHW is performed based on the branch-and-bound method. From the case study, it is shown that the load usage pattern can contribute to an efficient power consumption.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권4호
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• pp.1249-1265
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• 2022

Video streaming has become one of the most popular applications for mobile devices. The network bandwidth required for video streaming continues to exponentially increase as video quality increases and the user base grows. Multi-Path TCP (MPTCP), which allows devices to communicate simultaneously through multiple network interfaces, is one of the solutions for providing robust and reliable streaming of such high-definition video. However, mobile video streaming over MPTCP raises new concerns, e.g., power consumption and cellular data usage, since mobile device resources are constrained, and users prefer to minimize such costs. In this work, we propose a mobile video streaming framework over MPTCP (mDASH) to reduce the costs of energy and cellular data usage while preserving feasible streaming quality. Our evaluation results show that by utilizing knowledge about video behavior, mDASH can reduce energy consumption by up to around 20%, and cellular usage by 15% points, with minimal quality degradation.

• Journal of Communications and Networks
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• 제8권2호
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• pp.151-157
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• 2006

In a continuously expanding wireless world, the number of radio systems increases every day and efficient spectrum usage becomes a more significant requirement. Ultra-wideband (UWB) and cognitive radio are two exciting technologies that offer new approaches to the spectrum usage. The main objective of this paper is to shed the first light on the marriage of these two important approaches. The strength of orthogonal frequency division multiplexing (OFDM) based UWB in co-existing with licensed systems is investigated. The opportunity concept is defined, and the requirements of the opportunistic spectrum usage are explained. It is proposed to take the UWB-OFDM from the current underlay implementation, and evolve it to a combined underlay and opportunistic spectrum usage technology, leading to cognitive UWB-OFDM. This way, we aim at making UWB more competitive in the wireless market with extended range, higher capacity, better performance, and a wide variety of applications.

• 한국정보시스템학회지:정보시스템연구
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• 제9권1호
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• pp.45-59
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• 2000

This study empirically tests that user satisfactions are influenced by factors focusing on information systems. The findings are as follows； 1. User Participation on information systems influence significantly system reliability, system usage and work environment. 2. Only top management's support on information system influences significantly efficient system usage. 3. Ability of user computing on information system influences significantly system usage.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권8호
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• pp.2490-2506
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• 2022

In Mobile Edge Computing (MEC), attackers can speculate and mine sensitive user information by eavesdropping wireless channel status and offloading usage pattern, leading to user privacy leakage. To solve this problem, this paper proposes a Privacy-preserving and Energy-efficient Offloading Algorithm (PEOA) based on Lyapunov optimization. In this method, a continuous Markov process offloading model with a buffer queue strategy is built first. Then the amount of privacy of offloading usage pattern in wireless channel is defined. Finally, by introducing the Lyapunov optimization, the problem of minimum average energy consumption in continuous state transition process with privacy constraints in the infinite time domain is transformed into the minimum value problem of each timeslot, which reduces the complexity of algorithms and helps obtain the optimal solution while maintaining low energy consumption. The experimental results show that, compared with other methods, PEOA can maintain the amount of privacy accumulation in the system near zero, while sustaining low average energy consumption costs. This makes it difficult for attackers to infer sensitive user information through offloading usage patterns, thus effectively protecting user privacy and safety.

• 한국농공학회논문집
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• 제66권2호
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• pp.13-24
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• 2024

This study aims to contribute to efficient paddy field water management by developing an IoT-based automatic paddy inlet that can consider water level changes according to variations in the supplied water quantity through irrigation channels. This IoT-based automatic paddy inlet not only ensures water level changes based on the supply of irrigation water but also secures irrigation efficiency. The effectiveness and efficiency of the developed IoT-based automatic paddy inlet were presented to contribute to efficient paddy field water management. As a result, the IoT-based automatic paddy inlet demonstrated the capability to maintain the optimal water level in the paddy field. Particularly, it exhibited up to 18.4% higher water resource usage efficiency compared to conventional paddy inlet, emphasizing the IoT-based automatic paddy inlet's advantage in terms of water resource usage.

• 아태비즈니스연구
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• 제9권4호
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• pp.13-27
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• 2018

This study aims to explore and identify factors of respondent's on the definition of 'smart community facilities', their usage and satisfaction in Malaysia. Study carried out in four sites which were Kota Belud, Kemaman, Lundu and Putrajaya. Data was collected through qualitative method where interviews was carried out with several smart community members in answering factors that drives the usage/participation, satisfaction and continuance intention from using the 'smart community facilities'. Interpretation from the qualitative approach reveals that community thinks infrastructure, content and digital services will help to generate and build up 'smart community'. This will give the benefit for the whole community as well as improve individual efficiency, lifestyles and well-being. Findings demonstrated that the advance of Internet will enhance people usage on being 'smart' and efficient and it should be further improved with better infrastructures, systematic development with sophisticated digital technology services, facilities and structured content, and also safety-security measures in place.