• Journal of Digital Convergence
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• v.14 no.11
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• pp.313-318
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• 2016

Recently, the smart farm development using a PC and smart phone to manag the farm for improving competitiveness is in progress. In the smart farm, by using the various ICT technology including RFID, Wi-Fi, ZigBee, Wireless LAN, and etc., the growing environment of the crop and animals can be managed with the remote. By using the network including not only the TCP/IP based wired network but also ZigBee, Wireless LAN, and etc., each of the devices installed in the smart farm transmits the growing environment data to the server. So, smart farms have information and network security vulnerability. Therefore, we propose the method that analyzes the security vulnerability which can begenerated in the smart farm and user authentication method.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.69-74
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• 2009

A novel protocol is proposed to achieve sub-carner-based rate adaptation in OFDM-based wireless systems. The protocol requires the addition of one OFDM symbol to the Clear-to-Send (CTS) packet defined in the IEEE 802.11 standard_ When receiving a Ready-To-Send (RTS) packet, the receiver determines the number of bits to be allocated in each sub-carrier through channel estimation. This decision is delivered to the sender using an additional OFDM symbol. That is, bit-allocation over sub-carriers is achieved using only one additional OFDM symbol. The protocol also provides an error recovery process to synchronize the bit-allocation information between the sender and receiver. The protocol enhances the channel efficiency in spite of the overhead of one additional OFDM symbol.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.193-199
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• 2009

Powerline communications (PLC) technology has been discussed and analyzed as a highly potential candidate of wireline access network solutions. In this paper, performance of double binary turbo coded orthogonal frequency division multiplexing (OFDM) system is analyzed and simulated in power line communications channel. In order to make power line channel environments, Bernoulli-Gaussian noise is considered. The performance is evaluated in terms of bit error probability. From the simulation results, it is demonstrated that the double binary turbo coding scheme offers considerable coding gain with reasonable encoding complexity. It is also shown that the system performance can be substantially improved by increasing the number of iterations.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.5
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• pp.77-83
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• 2013

Nowadays, the limitation of Lighting control and management skills is the excessive cost of equipments, the operational difficulties and wasting energy. To solve this problem is in need of communication and management S/W that is worked out complexly well as a information system of smart lighting energy, which is loaded wireless network facility. This paper made a study od the energy saving technology through energy monitoring and we developed LEIS(Lighting Energy Information Sysem) to converge this one. LEIS is monitoring and control lighting energy data that is collelcted from sensors by Zigbee mesh network and shows lighting use information by visualization to users. It is consists of lighting energy information data base based on LEM(Lighting Energy Metering) information and LEIS Web application, provide function scenario to manage energy optimization through LEIS.

• Journal of Intelligence and Information Systems
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• v.12 no.2
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• pp.1-15
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• 2006

Currently the mobile web service is growing with a tremendous speed and mobile contents are spreading extensively. However, it is hard to search what the user wants because of some limitations of cellular phones. And the music is the most popular content, but many users experience frustrations to search their desired music. To solve these problems, this research proposes a hybrid recommendation system, MOBICORS-music (MOBIle COntents Recommender System for Music). Basically it follows the procedure of Collaborative Filtering (CF) system, but it uses Contents-Based (CB) data representation for neighborhood formation and recommendation of new music. Based on this data representation, MOBICORS-music solves the new item ramp-up problem and results better performance than existing CF systems. The procedure of MOBICORS-music is explained step by step with an illustrative example.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1055-1059
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• 2004

A RFID(Radio Frequency Identification) system is a kind of radio frequency communication system and a branch of automatic data collection system. RFID system consists of RFID tags(or transponders) and RFID readers(controllers). This paper deals with the wireless communication that acquires tag IDs through RFID readers, and show the implementation of the target system which transmits tag IDs and related information to the server on the Internet through the wireless local area network. Today's RFID systems are usually implemented with the wired communication environment. In this paper, however, RFID system is effectively realized with the widely deployed wireless local area network and various RFID data can be collected by the readers which are communicating with the wireless access points of the local area network. Through the Internet, users also can have easy access to the server on the web and retrieve, analyze, and utilize tags' information.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.984-987
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• 2013

In concept, such as the backup of wired network and disaster prevention network of water treatment measurement and control system, reliability and security of high level of sending and receiving data between the nodes must be ensured in Ad-hoc network construction. Rather than apply the common communication protocols of Ad-hoc network construction during the FA network of closed water treatment facility with the facility of a certain scale is concentrated contrast, and high characteristics of the water treatment system infrastructure, public facilities We have developed a specific protocol another that applies the OTP of communication frame of process control commands and H-ARQ with ZRP by applying the flexibility to time constraints such as precision industrial plants to ensure the safety and property of facility operation.

• Journal of Practical Engineering Education
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• v.7 no.2
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• pp.113-117
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• 2015

In this academic paper, we introduce a bread board simulation which is developed based on HTML language. this program is developed because actual electronic practices have some problems. Electronic circuit practice using bread board is widely practiced in colleges or high schools in South Korea, but actual electronic circuit practice needs lots of consumable stuff, and they are needed to be purchased and managed continuously. Besides, composing complicated electronic circuit restricts the efficiency of studying. Therefore, we propose breadboard simulation program which helps to resolve those problems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3B
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• pp.224-231
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• 2006

The location information of wired 112, 119 emergency call is provided immediately by subscriber database of KT. But emergency call made by mobile phone should be ask location information to mobile network. This paper proposes the network protocol for mobile emergency service refer to TIA/EIA/J-STD-036-A with reviews about technical issues, legacy factors and related researches. The mobile emergency service is divided to mobile emergency rescue service and mobile emergency alert service. The network reference model for mobile emergency rescue service is released in domestic sector. In this paper, the interfaces between modules of the network reference model, and service scenarios, message flows are defined. Supplement to mobile emergency rescue service, the network reference model, interfaces and message flows for mobile emergency alert service are developed.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.6
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• pp.1337-1342
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• 2012

In recent years, many researches in Home Networking are being progressed actively. Most of techniques for Home Networking are based on wired but the technique for wireless connection is also needed. This paper focuses on wireless connection in Home Networking. Of many of wireless technologies, such as Wireless LAN, Bluetooth, or HomeRF, we especially propose to apply the new technique called Wireless Sensor Network. We present hardware and protocol stack design consideration for wireless sensor node and wireless sensor network, and then we present how to apply wireless sensor network to Home Networking and how to constitute Wireless Home-Networking with a variety of sensor nodes. Finally, we introduce the wireless sensor node system designed by us and conclude this paper.