• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.3
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• pp.1510-1532
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• 2017

In smart grid, privacy implications to individuals and their families are an important issue because of the fine-grained usage data collection. Wireless communications are utilized by many utility companies to obtain information. Network coding is exploited in smart grids, to enhance network performance in terms of throughput, delay, robustness, and energy consumption. However, random linear network coding introduces a new challenge for privacy preserving due to the encoding of data and updating of coefficients in forwarder nodes. We propose a distributed privacy preserving scheme for random linear network coding in smart grid that considers the converged flows character of the smart grid and exploits a homomorphic encryption function to decrease the complexities in the forwarder node. It offers a data confidentiality privacy preserving feature, which can efficiently thwart traffic analysis. The data of the packet is encrypted and the tag of the packet is encrypted by a homomorphic encryption function. The forwarder node random linearly codes the encrypted data and directly processes the cryptotext tags based on the homomorphism feature. Extensive security analysis and performance evaluations demonstrate the validity and efficiency of the proposed scheme.

• Survey Research
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• v.7 no.1
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• pp.1-28
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• 2006

The aim of this study is to develop a scale measuring satisfaction to ubiquitous services. Since the ubiquitous service is not vet implemented but under development, conventional scale construction methods are not directly applicable. In this study, the characteristics of items are studied by observing individual's responses after presenting a video clip describing virtual services. The constructs of ubiquitous service are defined based on those of information system and previous studies of ubiquitous services. Items were generated to reflect the constructs. In the first study, we found six factors (me-centeredness, attractiveness, usability, trust, accessibility, ownership) in the ubiquitous service scale by using exploratory and confirmatory factor analysis. Some items were dropped out that did not show good psychometric properties. In the second study, relationships among the constructs and satisfaction of the service was investigated by using structural equation models. An SEM analysis showed that these six constructs can predict the satisfaction about ubiquitous system, Practical implications and utility of this scale are discussed.

• Journal of Broadcast Engineering
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• v.26 no.4
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• pp.390-397
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• 2021

As digital twin technology is applied to various industrial fields, technologies to effectively process large amounts of data are required. In this paper, we discuss a customized service method for fast search and effective delivery of large-scale data for underground facility for public utilities management. The proposed schemes are divided into two ways: a fast search data generation method and a customized information service segmentation method to efficiently search and abbreviate vast amounts of data. In the high-speed search data generation, we discuss the configuration of the synchronization process for the time series analysis of the sensors collected in the underground facility and the additional information method according to the data reduction. In the user-customized service method, we define the types of users in normal and disaster situations, and discuss how to service them accordingly. Through this study, it is expected to be able to develop a systematic data generation and service model for the management of underground utilities that can effectively search and receive large-scale data in a disaster situation.