• Journal of KIISE
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• v.41 no.9
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• pp.686-698
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• 2014

Recently, large-scale streaming sensor data have emerged due to explosive supply of smart phones, diffusion of IoT and Cloud computing technology, and generalization of IoT devices. Also, researches on combination of semantic web technology are being actively pushed forward by increasing of requirements for creating new value of data through data sharing and mash-up in large-scale environments. However, we are faced with big issues due to large-scale and streaming data in the inference field for creating a new knowledge. For this reason, we propose the RDFS rule based parallel reasoning scheme to service by processing large-scale streaming sensor data with the semantic web technology. In the proposed scheme, we run in parallel each job of Rete network algorithm, the existing rule inference algorithm and sharing data using the HBase, a hadoop database, as a public storage. To achieve this, we implement our system and evaluate performance through the AWS data of the weather center as large-scale streaming sensor data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2707-2712
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• 2012

Desktop-based computing environment is changed into mobile computing using smart phone and cloud computing providing common behavior and big data by network. Because of this transformation software development and operating environment is changed into heterogeneous distributed environment. As a result, dynamic service composition or changement is required. However, there is few research of techniques supporting service composition or changement dynamically in this situation. This paper suggests a technique for customizing services dynamically of mobile applications based on android platform. Especially we propose a customization technique of service by applying ontology technique to improve sharing and reuse of service. We applied proposed technique into meeting notification system, and obtain that it can be customized into various services such as email, sms, twitter service, and so on.

• Journal of KIISE
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• v.42 no.12
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• pp.1623-1628
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• 2015

As the performance of mobile devices has increased, high-end multicore CPUs have become the norm in smartphones. However, such high performance devices are exposed to the problem of battery depletion due to the energy consumption caused by software performance, and despite increases in battery capacity. The required resources are dynamic and varied, and further user interaction is highly random; thus, Linux-based power management such as DVFS is needed to fulfill requirements. In order to reduce power consumption, we propose a method to restrict the CPU frequency of data download while maintaining user reactivity. This can supplement the weakness of existing Linux-based power management techniques like DVFS in relation to webpage loading. Through the implementation of our method at the application level, we confirm that energy consumption from webpage loading is reduced.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.590-598
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• 2016

It comes into the spotlight as the new Blue Ocean in which the connected car industry in which the car and mobile communication technology is convergence. All sorts of infortainments services connecting with the portable electronic device(Smart phone, tablet PC, and MP3 player) and car are rapidly grown. The Connected car emphasizes the vehicle connectivity with the concept that the car has communication with the around on a real time basis and it provides the safety and expedience to the operator and using the thing of Internet (IoT) in the car and supports the application, presently, the entertainment service including the real-time Navigation, parking assistant function, not only the remote vehicle control and management service but also Email, multimedia streaming service, SNS and with the platform. Intelligent vehicle network is studied as the kind according to MANET(Mobile Ad Hoc Network) for the safety operation of the cars of the road and improving the efficiency of the driving.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06d
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• pp.455-460
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• 2008

건설교통부는 국가미래에 대비해 실질적으로 기여할 수 있는 전략적이고 중장기적인 실효성 있는 R&D 혁신 로드맵인 VC-10 사업을 진행하고 있다. 이 과제의 핵심 기술 중에 하나인 유비쿼터스 센서네트워크는 초소형 센서들로 구성된 망으로써 환경 및 재난 재해, u-City 건설, 스마트 하이웨이, 방범 및 국방, 시설 관리, 유통, 등과 같은 다양한 분야에 사용할 수 있는 유비쿼터스 사회의 핵심 요소이다. 이것은 실시간 네트워크를 통해 전송 또는 관리되고 언제, 어디서나, 어떠한 대상과 의사소통이 가능한 지능형 컴퓨팅 환경을 구현하는 것이다. 그러나 이러한 기술을 바탕으로 하는 기존의 시스템들은 특정분야를 위한 독자적인 프로토콜이나 저전력 통신을 제공하는 ZigBee 기반으로 설계되었기 때문에 소규모 범위에서만 서비스 제공이 가능하며 시스템간의 연동이 어렵다. 따라서 본 논문에서는 유비쿼터스 센서네트워크간의 연동성을 고려한 대규모 실시간 모니터링 시스템을 설계하여 다양한 분야로 서비스할 수 있는 테스트베드 구축에 대한 방안을 제시하고자 한다. 여기서 모니터링 대상은 국토의 지반, 환경, 그리고 도심지역 등이다. 이렇게 제시된 방안은 국내실정에 적합한 모니터링 시나리오를 작성하여 테스트베드를 구축 시에 요구된 사항들에 대한 정당성을 입증한다.

• The Journal of Society for e-Business Studies
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• v.20 no.2
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• pp.15-26
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• 2015

To prevent the spread of damage, initial reaction and emergency repair are important. But up to now they depend on some guidelines and man power owing to the lack of technical support. In this paper, we described the development process of several electronic documents and information management system of them to rapidly acquire and share damage information of the infrastructure. The damage information, which is acquired by the computer and smart phone, is transformed to the electronic documents and connected to data management system through the damage information acquisition network. These systems could readily be used for preparing a countermeasure of the disaster and disaster recovery.

• Journal of Digital Convergence
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• v.12 no.6
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• pp.311-316
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• 2014

Social network server due to the popularity of smart phones, and data stored in a big usable access data services are increasing. Big Data Big Data processing technology is one of the most important technologies in the service, but a solution to this minor security state. In this paper, the data services provided by the big -sized data is distributed using a double hash user to easily access to data of multiple distributed hash chain based data processing technique is proposed. The proposed method is a kind of big data data, a function, characteristics of the hash chain tied to a high-throughput data are supported. Further, the token and the data node to an eavesdropper that occurs when the security vulnerability to the data attribute information to the connection information by utilizing hash chain of big data access control in a distributed processing.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.2
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• pp.35-46
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• 2013

As a rapid increase of mobile network usage, many studies on solution for network traffic's demand problem have been done. Especially network environment measurement area provides basis for solving network traffic's demand problem by finding causes of problems through accurate network analysis. However, as increase of demand for smartphone, we should consider effects of mobile platform's property measuring mobile network. In this paper, we design a network traffic measurement system considering mobile platform. Through the information from packets, this system calculates packet transmission delay and throughput. We minimize computation cost required for a mobile device that is a client in this system. When fully using network resources, we found that Wi-Fi has shorter transmission delay, higher maximum throughput and lower loss rate than 3G, Android has shorter transmission delay and higher maximum throughput than iOS, and UDP has longer transmission delay and higher maximum throughput through this system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.53-60
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• 2017

This paper is to design and implement the drone that supports a wideband multimedia communication and a long-range to save people in maritime. The drone is an Unnamed Aerial Vehicle (UAV) that is controlled by a radio wave not by people boarding the machine. We use the drone to respond quickly to the boating accident. To develop a smart drone for the high speed seamless video streaming in a long-range maritime, a necessary techniques are hardware design techniques that design structure of a drone, controlling techniques that operate a drone and communication techniques that control a drone in a long distance. In this paper, the limitations and techniques to design and implement the structure of drone supporting wideband multimedia communication for long-range maritime are explained. By expanding this communication drone network, it is aimed at improving utility of a drone.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.63-66
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• 2015

As smart-phones become popular, mobile data traffic has been dramatically increasing and intensive researches on the next-generation mobile communication network is in progress to meet the increasing demand for mobile data traffic. In particular, heterogeneous network (HetNet) is attracting much interest because it can significantly enhance the network capacity by increasing the spatial resue with macro and small cells. In the HetNet, we have several problems such as load imbalance and interference because of the difference in transmit power between macro and small cells and cell range expansion (CRE) can mitigate the problems. In this paper, we propose a new cell selection scheme with adaptive cell range expansion bias (CREB) for ultra dense HetNet and we analyze the performance of the proposed scheme in terms of average cell transmission rate through system-level simulations and compare it with those of other schemes.