• ETRI Journal
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• v.32 no.5
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• pp.713-721
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• 2010

E-textile technology has earned a great deal of interest in many fields; however, existing wearable network protocols are not optimized for use with conductive yarn. In this paper, some of the basic properties of conductive textiles and requirements on wearable personal area networks (PANs) are reviewed. Then, we present a wearable personal network (WPN), which is a four-layered wearable PAN using bus topology. We have designed the WPN to be a lightweight protocol to work with a variety of microcontrollers. The profile layer is provided to make the application development process easy. The data link layer exchanges frames in a master-slave manner in either the reliable or best-effort mode. The lower part of the data link layer and the physical layer of WPN are made of a fabric serial-bus interface which is capable of measuring bus signal properties and adapting to medium variation. After a formal verification of operation and performances of WPN, we implemented WPN communication modules (WCMs) on small flexible printed circuit boards. In order to demonstrate the behavior of our WPN on a textile, we designed a WPN tutorial shirt prototype using implemented WCMs and conductive yarn.

• The KIPS Transactions:PartD
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• v.15D no.3
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• pp.327-336
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• 2008

Many XML-compliant UIDLs(User Interface Description Languages) have been developed to specify user interfaces. Although previous UIDLs are helpful to describe user interfaces of web and desktop applications, they are not available of developing UI of mobile applications. In this paper, in order to effectively specify user interfaces of MIDlet which is application model on J2ME(Java Platform, Micro Edition), we propose MIML(Midlet Interface Markup Language) and present transformation rules to generate source codes from MIML. Further, we enhance the usability of MIML through J2MERenderer which is a tool using presented rules. The proposed method can specify user interfaces of mobile applications and allow developers to keep productivity and consistency in development phase.

• Proceedings of the Korea Contents Association Conference
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• 2015.05a
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• pp.15-16
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• 2015

Measuring sensor, equipment, ICT facilities and their software have relatively short life time comparing to constructional structure so that we should exchange or fix them continuously in the process of maintenance and management. In this paper, we propose a novel design of integrated maintenance, management, and measuring monitoring system applying the concept of mobile cloud. For the sake of disaster prevention for constructional structures such as bridge, tunnel, and other traditional buildings in the village of local heritage, we analyze status of these structures in the long term or short term period as well as disaster situations. Collecting data based on mobile cloud and analyzing future expectations based on probabilistic and statistical techniques, we implement our integrated monitoring system for constructional structures to solve these existing problems. Final results of this design and implementation are basically applied to the monitoring system for more than 10,000 structures spread over national land in Korea. In addition, we can specifically apply the monitoring system presented here to a bridge of timber structure in Asan Oeam Village and a traditional house in Andong Hahoe Village to watch them from possible disasters. Total procedure of system design and implementation as well as development of the platform LinkSaaS and application services of monitoring functions implemented on the platform. We prove a good performance of our system by fulfilling TTA authentication test, web accommodation test, and operation test using real measuring data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.11
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• pp.1019-1028
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• 2013

The BWS (broadcast website) data broadcasting service for terrestrial DMB (digital multimedia broadcasting) has a great advantage that it can provide a website like service through broadcast without web traffic to a plurality of receiving terminals. However, the value of BWS has not been recognized due to the development of mobile communication technology and changes in the environment, where mobile web services through smart devices such as smart phones and pads are common. Recently, various hybrid service technologies provided through hybrid broadcasting, a fusion of broadcasting and communications, have been developed. In this paper, we propose a scalable BWS dividing the hierarchy of BWS into transmission layers and present its application for hybrid DMB data broadcasting services.

• Convergence Security Journal
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• v.15 no.1
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• pp.83-89
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• 2015

In the wide area surveillance system including many CCTVs, application for remote realtime monitoring is designed and implemented. The applications using Xcode provide secure administrator interface from headquarters. Through the efficient and intuitive interface, it delivers real-time context reports and inference results. For the user convenience, it includes push alarm of events, SNS, Media streaming service for real-time monitoring uses Wirecast and Wowza media server. Wowza stream engine provides URL accommodating development specification. Mobile devices can receive real-time stream data. Performance evaluation in the processing is provided.

• Ecology and Resilient Infrastructure
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• v.6 no.4
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• pp.277-286
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• 2019

The construction industry is known to be one of the representative industries that generate fine dust. Therefore, reducing the amount of fine dust generated in construction sites is very important for the overall fine dust management. Based on this, this study proposed the fine dust measurement and removal technology combined with advanced technologies such as autonomous mobile vehicle IoT and DFS. The qualitative, quantitative and risk elimination effects that can be expected when applying the proposed technique are analyzed. The proposed technique will be validated through system development and field application and evaluated specific economics through cost analysis.

• Journal of Information Processing Systems
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• v.14 no.1
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• pp.56-78
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• 2018

Security issue in mobile ad hoc network (MANET) is a promising research. In 2011, we had accomplished a survey of black hole attacks in MANETs. However network technology is changing with each passing day, a vast number of novel schemes and papers have been proposed and published in recent years. In this paper, we survey the literature on malicious attacks in MANETs published during past 5 years, especially the black hole attack. Black hole attacks are classified into non-cooperative and collaborative black hole attacks. Except black hole attacks, other attacks in MANET are also studied, e.g., wormhole and flooding attacks. In addition, we conceive the open issues and future trends of black hole detection and prevention in MANETs based on the survey results of this paper. We summarize these detection schemes with three systematic comparison tables of non-cooperative black hole, collaborative black hole and other attacks, respectively, for a comprehensive survey of attacks in MANETs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.2
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• pp.383-403
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• 2021

With the development of mobile edge computing (MEC), some late-model application technologies, such as self-driving, augmented reality (AR) and traffic perception, emerge as the times require. Nevertheless, the high-latency and low-reliability of the traditional cloud computing solutions are difficult to meet the requirement of growing smart cars (SCs) with computing-intensive applications. Hence, this paper studies an efficient offloading decision and resource allocation scheme in collaborative vehicular edge computing networks with multiple SCs and multiple MEC servers to reduce latency. To solve this problem with effect, we propose a context-aware offloading strategy based on differential evolution algorithm (DE) by considering vehicle mobility, roadside units (RSUs) coverage, vehicle priority. On this basis, an autoregressive integrated moving average (ARIMA) model is employed to predict idle computing resources according to the base station traffic in different periods. Simulation results demonstrate that the practical performance of the context-aware vehicular task offloading (CAVTO) optimization scheme could reduce the system delay significantly.

• Journal of Distribution Science
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• v.20 no.11
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• pp.33-45
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• 2022

Purpose: The development of online shopping trends in Indonesia is increasing, and Tokopedia is becoming one of the most popular e-commerce websites. The purpose of this study is to obtain empirical evidence whether mobile shopping, customer review, perceived credibility, and Korean celebrity endorsement affect online purchase decision, whether online purchase decision affects customer satisfaction, and whether customer satisfaction affects brand loyalty of customers in Tokopedia e-commerce. Research Design, data and methodology: Quantitative survey with data was collected using an online questionnaire with sample characteristics were Tokopedia customers who lived in Jakarta by 385 samples using the purposive sampling method, and data analysis was conducted using the Smartpls application program version 3.0. Results: Mobile shopping, customer review, and perceived credibility had positive effects on online purchase decision at Tokopedia in Jakarta. However, Korean celebrity endorsement did not have a positive effect on online purchase decision at Tokopedia in Jakarta. Furthermore, online purchase decision had a positive effect on customer satisfaction at Tokopedia in Jakarta, and customer satisfaction had a positive effect on brand loyalty at Tokopedia in Jakarta. Conclusions: This study proposes significant implications for maintaining customer relationships to achieve purchasing decision, customer satisfaction, and brand loyalty in the e-commerce industry.

• Journal of Hydrogen and New Energy
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• v.14 no.1
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• pp.35-45
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• 2003

Polymer electrolyte fuel cells(PEFC) have been considered to be a suitable candidate for residential, portable and mobile applications, due to their high efficiency and power density, even at low operating temperature. KIER developed a 5kW class PEFC system for residential application and operated the system for over 1,000 hours. To develop a 5kW PEFC system, performance of a cell was improved through successive tests of single cell of small and large area. Fabrication of three 2,5 kW class stacks, design and fabrication of natural gas reformer, design of auxiliary equipments such as DC/DC converter, DC/AC inverter and humidifying units were carried out along with integration of components, operation and evaluation of total system. During the development period from 1999 to 2001, MEA(membrane electrode assembly) fabrication technologies, design and fabrication technologies for separators, stacking technologies and so on were developed, thereby providing basis for developing stacks of higher efficiency and power density in the future. Experience of development of natural gas reformer opened possibilities to use various kinds of fuels. Main results obtained from the development of a 5kW class PEFC system for residential application are summarized.