• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.853-871
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• 2012

The location based service is divided into GPS that uses the artificial satellite or base transceiver station in order to cover the wide area and RTLS(Real Time Location System) using the Zigbee, RFID, CSS(Chirp Spread Spectrum), UWB, Bluetooth and Wi-Fi equipment in the space(close range) limited like the building inside or park. Moreover it also repeats the technical development upon through the acceleration of the development of the wire and wireless infrastructure and determination technology, the development of the Internet, diversification of the contents, and etc. As a result, it is expected to develop around the determination technology, witch is common core technology element, contents technology, Internet and mobile communication technology, and etc. afterward. In this research, the direction we investigate was to find and analyze new technology and standardization trend of LBS in order to contribute to the related industry.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.172-174
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• 2007

An electronic watt-hour meter with high-precision measurement technology can provide many valuable metering data of a real-time system measurements, such as per-phase voltage, ampere, active power, reactive power, apparent power, power factor, and system frequency. Also many of accumulated metering data such as active energy, reactive energy, apparent energy, and load profile can be gettable from an electronic watt-hour meter[1]. This paper presents an approach of the small-sized AMR (Automatic Meter Reading) that provides customers with a very valuable electrical service. This AMR service transmits lots of a valuable metering data by using ZigBee communication module, so that users resided in their premises can use the information to audit a power quality and improve their electrical conditions by using the PQ monitoring device equipped with ZigBee receiver. This PQ monitoring device shows metering data on LCD and transmits to the PC through an internal network. Also, the device can keep the valuable meter data into a built-in non-volatile memory. The final goal of this paper is to better understand the power quality of electrical systems and offer the power qualify information for the convenience of all power consumers.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.1
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• pp.74-80
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• 2010

We implemented an application system which is able to verify visitor identification for remote bundle control based on OSGi and web camera control using embedded linux system. This system are designed open Oscar framework by porting java on the embedded linux system and implemented web camera system in local area networks. Also This system can verify information of visitor from receiving the data of RFID reader and designed the wireless internet system in home. Basically, in this paper we expect that home network system development and the period of application service development are reduced with integrated service provision based on OSGi.

• Journal of IKEEE
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• v.13 no.3
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• pp.87-94
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• 2009

TETRA(TErrestrial Trunked RAdio) is the wireless communication system generally adopted to public network and backbone network, as the technology of Trunked Radio System specified by ETSI(European Telecommunications Standards Institute) and currently adopted to the Electric Power IT Backbone Network in Korea. IEC 61850 is the protocol proposed for SAS(Substation Automation System) of SCADA(Supervisory Control And Data Acquisition) system. In this paper, IEC 61850 Server and Client simulator are used based on Linux operating system. The multi-functional gateway, which transforms the communication based on TCP/IP between IEC 61850 Server Simulator and Client Simulator to the one based on TETRA Packet Data Service, is developed such that IEC 61850 SCADA system is constructed based on TETRA.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.772-775
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• 2008

As the wireless communication technology developed, the Electric Commerce using a mobile was activated. WPKI was developed in order to guarantee the stability of the Electric Commerce but it is difficult to be ensured for the safe PKI service which is the same at the wire communication in the technical because of restriction of the mobile terminal. In this paper, we propose the authentication system for the electronic financial service which is safe and is effective in consideration of the restrictive characteristic of the mobile terminal. Moreover, the encryption algorithm for the safe electronic signature is proposed. In WPKI, this makes the cross certification of each certificate authority possible. Moreover, a stability was enhanced through the signature authentication using KCDSA and SEED algorithm.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.1-8
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• 2018

It is the content and scope of this study to analyze the problems of the current wireless service and the classification system of the radio station, and to examine the case of radio control in Japan and to establish a reasonable and efficient radio wave management plan. The results of this study can be used as basic data for reorganizing the legislation on radio wave enforcement ordinance, radio services and radio station classification standards. It is expected that it will be possible to improve the compliance and efficiency of the radio station licensing and inspection service while enhancing the policy compliance in the practical work by providing detailed explanations on the definition and classification system of the new radio task / radio station in the future.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.2
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• pp.233-238
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• 2015

In this paper, we proposed that immersive audio effect method using the effective noise to improve engagement in free-viewpoint TV(FTV) service. In the basketball court, we monitored the frequency spectrums by acquiring continuous audio data of players and referee using shotgun and wireless microphone. By analyzing this spectrum, in case that users zoomed in, we determined whether it is effective frequency or not. Therefore when users using FTV service zoom in toward the object, it is proposed that we need to utilize unnecessary noise instead of removing that. it will be able to be useful for an immersive audio implementation of FTV.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.5
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• pp.61-72
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• 2013

Next-generation ITS(Intelligent Transportation System) adopts WAVE(Wireless Access in Vehicular Environment) system which is capable of the bidirectional communication system in vehicular environments. u-Transportation system adopted WAVE communications system to show the optimal performance in terms of various services with regard to vehicle safety and traffic. In this paper, we introduce testbed of ubiquitous-Transportation system and its service. Then, we describe WAVE system for supporting next-generation ITS service. Also, we carried out tests in real road environments in order to verify communication functions of WAVE systems and its performance. We confirmed that our communication systems for supporting services meet the communication performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.3
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• pp.519-525
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• 2014

In this paper, we show a scheme to directly access DLNA network with the 3G/4G communication module of a smartphone in home or office environment. By exploiting this scheme, end users can use DLNA service more conveniently regardless of the type of activated communication module in a smartphone. For the implementation of this scheme, we use a femtocell that is a basestation with small coverage. A problem caused by the IP address hierarch discrepancy between the IP address of 3G/4G module of smartphone and those of local network nodes is resolved by deploying local IP address scheme. The processing of multicasting packet, that is required in DLNA service, is enabled by using IP tunneling scheme. As a result, end user can access DLNA network regardless of the type of activated wireless communication module. We validate the design result by implementing it on a commercial WCDMA femtocell.

• Journal of information and communication convergence engineering
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• v.14 no.1
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• pp.21-25
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• 2016

N-screen is a promising technology to improve support for multimedia multicasting, content sharing, content mobility, media scalability, and seamless mobility. In this paper, the WiMedia distributed-MAC (D-MAC) protocol is adopted for development of a seamless N-screen wireless service. Furthermore, to provide a multi-hop, one source multi-use N-screen service through point to point streaming in a seamless D-MAC protocol, a dynamic multi-frame transmission technology is proposed. In this technology, a dynamic time slot allocation scheme and a multi-hop resource reservation scheme are combined. In the proposed dynamic time slot allocation scheme, two thresholds, a hard threshold and a soft threshold, are included to satisfy the power consumption and delay requirements. A multi-frame DRP reservation scheme is proposed to minimize end-to-end delay during the multi-hop transmissions between N-screen devices. The proposed dynamic multi-frame transmission scheme enhances N-screen performance in terms of the multi-hop link establishment success rate and link establishment time compared to the conventional WiMedia D-MAC system.