• Journal of Electrical Engineering and Technology
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• v.3 no.2
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• pp.192-198
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• 2008

This paper proposes a FRTU-based intelligent fault distance determination strategy in which each FRTU is able to avoid multiple estimations and reduce the level of estimation error by utilizing heuristic rules driven by voltage and current information collected by 1:1 communication with other FRTUs from the same zone in a ubiquitous-based distribution system. In the proposed method, each FRTU, at first, determines a fault zone and a fault path on the faulted zone based on the proposed heuristic rules which use its current data and the voltage data of its neighboring FRTUs as input data. Next, it determines the fault distance from its position based on the fault current estimated from the current data of the neighboring FRTUs. Finally, in order to prove the effectiveness of the proposed method, the diverse fault cases are simulated in several positions of the typical distribution system using the EMTP.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.9
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• pp.1653-1667
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• 2011

Privacy is one of the most important and difficult research issues in ubiquitous computing. It is qualitative rather than quantitative. Privacy preserving mainly relies on policy based rules of the system, and users cannot adjust their privacy disclosure rules dynamically based on their wishes. To make users understand and control their privacy measurement, we present a scheme to quantize the personal privacy. We aim to configure the person's privacy based on the numerical privacy level which can be dynamically adjusted. Instead of using the traditional simple rule engine, we implement this scheme in a complex way. In addition, we design the scenario to explain the implementation of our scheme. To the best of our knowledge, we are the first to assess personal privacy numerically to achieve precision privacy computing. The privacy measurement and disclosure model will be refined in the future work.

• Progress in Superconductivity and Cryogenics
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• v.22 no.4
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• pp.6-9
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• 2020

Since the discovery of superconductivity, the unique and mysterious phenomenon has been observed in various metallic material systems. Now days, the superconductivity becomes ubiquitous because almost every metallic material system shows the superconductivity when it is cooled down enough. This ubiquity of the superconductivity is associated with the fermionic nature and itinerancy of electrons in metallic materials. Because fermions are governed by the Pauli's exclusion principle the total energy of fermions is much larger than that of bosons. Therefore, fermionic itinerant electrons are fundamentally instable. Itinerant electrons are able to find "a way" to lead them to their lowest possible energy state through an available bosonization (or pairing) process and Bose-Einstein condensation. Therefore, the lowest possible energy state of itinerant electrons will be a superconducting state, which is "their ultimate destination". This may explain the reason why the superconductivity is ubiquitous.

• Annual Conference of KIPS
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• 2007.05a
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• pp.1107-1109
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• 2007

Context-based access control is an emerging approach for modeling adaptive solution, making access control management more flexible and powerful. However, these strategies are inadequate for the increased flexibility and performance that ubiquitous computing environment requires because such systems can not utilize effectively all benefit from this environment. In this paper, we propose a solution based on risk to make use of many context parameters in order to provide good decisions for a safety environment. We design a new model for risk assessment in ubiquitous computing environment and use risk as a key component in decision-making process in our access control model.

• Journal of Intelligence and Information Systems
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• v.14 no.2
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• pp.1-20
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• 2008

This study is aimed at proposing a new approach to designing UDSS (Ubiquitous Decision Support System) which allows context-awareness and connectivity. In the previous studies, the need to design UDSS and analyze its performance empirically was raised. However, due to the complexity of empirical approaches, there is no study attempting to tackle this research issue so far. To fill this research void, this study proposes a Mobile Delivery System (MDS) as a form of UDSS, empirically analyzing how users perceive its context-awareness and connectivity functions. Especially, to add more rigor to the proposed approach to know how much it works well in the decision-making contexts, we considered three decision making phases (intelligence, design, choice) in the research model. With the valid questionnaires collected from 340 users of the MDS, we induced statistically proven results showing that both context-awareness and connectivity of the proposed UDSS (or MDS) influence the decision making steps positively and then contribute to improving the decision making quality.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.8 no.1
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• pp.42-51
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• 2008

We believe that smart spaces, offering pervasive services, will proliferate. However, at present, those islands of smart spaces should be joined seamlessly with each other. As users move about, they will have to roam from one autonomous smart space to another. When they move into the new island of smart space, they should setup their devices and service manually or not have access to the services available in their home spaces. Sometimes, there will conflicts between users when they try to occupy the same space or use a specific device at the same time. It will also be critical to elder people who suffer from Alzheimer or other cognitive impairments when they travel from their smart space to other visited spaces (e.g., grocery stores, museums). Furthermore our experience in building the Gator Tech Smart House reveals to us that home residents generally do not want to lose or be denied all the features or services they have come to expect simply because they move to a new smart space. The seamless inter-space interaction requirements and issues are raised automatically when the ubiquitous pervasive computing system tries to establish the user's service environment by allocating relevant resources after the user moves to a new location where there are no prior settings for the new environment. In this paper, we raise and present several critical inter-space interactions issues impacting middleware architecture design of ubiquitous pervasive computing. We propose requirements for resolving these issues on seamless inter-space operation. We also illustrate our approach and ideas via a service scenario moving around two smart spaces.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.526-531
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• 2009

Recently, many interests on the ubiquitous environment and the practical technologies associated with it have been significantly increasing along with the rapid development of wireless technologies. The development of the automated systems based on the ubiquitous environment is required as the concept of the term "ubiquitous" is integrated into the fields of existing IT. In this paper, we design and implement a power-saving management system using RFID/USN technologies. It efficiently manages the power consumption of the electronic machine such as electric lights, electric heaters, and air conditioners in a building. The proposed system controls the electronic machines and monitors their status by RFID and collects the real time information about the surroundings and power consumption of the electronic machines by USN. Especially, it analyzes the real time information and supports the intelligent scheduler with the best power-saving. Finally, this paper shows the difference between the proposed system and the existing systems and the reality of our system through the real time user interface about the power-saving management.

• The Journal of Information Systems
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• v.25 no.3
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• pp.31-60
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• 2016

Purpose In 2016, the market size of mobile(m-) shopping goes beyeond more than half of a total of online shopping. People use smartphones as the main device for m-commerce. Under the circmustances, this study attempts to address why people prefer to use smartphone-based m-commerce. In other words, it is necessary to understand the main value that smartphone-based m-commerce creates. Drawing on the studies of consumption value, this study focuses on utilitarian value in predicting customers' continuance intention in the context of smartphone-based m-commerce, recognizing that utilitarian value is a key extrinsic motivation in the goal-oriented, performance-oriented shopping contexts. Furthermore, this study identifies factors affecting customers' utilitarian value from the perspective of benefits and costs, following the notion that it represents the result of evaluating a trade-off of benefits and costs caused by smartphone-based m commerce. More specifically, in this study, ubiquitous service, location-based service (LBS), transaction speed, and price utility belong to the benefit dimension, whereas technology anxiety and cognitive effort belong to the cost dimension. Design/methodology/approach To test the proposed hypotheses, the study conducted partial least squares (PLS) analysis with a total of 294 data collected on users with experience in smartphone-based m-commerce. Findings The results show that first, utilitarian value is increased by the benefits, such as ubiquitous service, transaction speed, and price utility. However, LBS has no direct effect on utilitarian value. Second, the noteworthy finding is that ubiquitous service and LBS greatly increase transaction speed. Third, technology anxiety and cognitive effort considered as the cost dimension are negatively associated with utilitarian value but their impacts on it are non-significant. Finally, the results support the argument that utilitarian value is a determinant of continuance intention. Overall, the findings imply that utilitarian value greatly depends on the peception on benefits rather than the aspect of cost in smartphone-based m-commerce. Overall, the findings offer new insight into the studies of m-commerce by considering and verifying the impacts of its benefits and costs simultaneously.

• Journal of Intelligence and Information Systems
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• v.12 no.2
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• pp.49-65
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• 2006

In this research, we are suggesting intelligent information system fur traveling which is focusing on product bundling and integration of information from various resources on ubiquitous computing environment. It is necessary for products structure to easily integrate according to customers' requirements because traveling product is integrated by various traveling resources like airline, hotel reservation, and so on. To guarantee of traveler's mobility in ubiquitous computing environment, we need product bundling and modification process to configure products and semantic web service which supports ontology based traveling information system to support immediate integrating of traveling information from various resources. In this research, we offer a product bundling and integration of information. It is based on the semantic web service, with several components (single products) to reconfigure a bundle of traveling products.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.252-254
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• 2015

In the maritime field, desktop-based ENC systems and services have been used for supporting the safe navigation of ship. However, with increasing level of needs for mobile device-based marine information service, ENC systems that provides basis for maritime service needs to be ported to mobile device. It is difficult to directly port desktop ENC system to the mobile devices, because the system operating environment and methods such as process management and memory management of the mobile devices are different from the desktop. In this paper, we analyze the characteristics of the Android-based mobile devices. Based on this, during porting process of desktop-based ENC system to android system, we modified and improved the display module with the characteristics of Android-based mobile devices in mind.