• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국정보통신학회 2012년도 추계학술대회
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• pp.405-406
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• 2012

A sensor network is composed of a large number of sensor nodes which have sensing, computation and wireless communication capabilities. The sensor node sends such collected data, usually via radio transmitter, to a command center (sink) either directly or through a data concentration center (a gateway). These sensor networks can be used for various application areas such as health, military, home network, managing inventory, monitoring disaster areas and so on. Moreover, owing to the rapid growth of mobile technology, high-performance smartphones are widespread and in increasing cases are utilized as a terminal device. In this paper, we propose a home management system using smartphone and sensor networks.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제37A권10호
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• pp.885-894
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• 2012

Currently, Demand of data traffic has rapidly increased by popular of smart device. It is very difficult to accommodate demand of data traffic by limited resource of base station (BS). To solve this problem, method has proposed that the Device-to-Device (D2D) reduce frequency overload of the BS and all of the user equipment (UE) inside the BS and neighbor BS don't allow communicating directly to BS. However, in LTE-Advance system cellular link and sharing radio resources of D2D link, the strong interference of the cellular network is still high. So we need to eliminate or mitigate the interference. In this paper, we use the transmission power control method and Soft Frequency Reuse (SFR) resource allocation method to mitigate the interference of the cellular link and D2D link. Simulation results show that the proposed scheme has high performance in terms of Signal to Noise Ratio (SINR) and system average throughput.

• Journal of the Korean Institute of Telematics and Electronics S
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• 제36S권10호
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• pp.1-9
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• 1999

In this paper, a subblock partition scheme for reduction of computational complexity in partial transmit sequence which reduces the peak-to-average power ratio in orthogonal frequency division multiplexing (OFDM) is proposed. In this scheme, complex signals are assigned into partial subbands randomly and signals in a partial subband are duplicated and concatenated repetitively to make a subblock. By modulation of active subbands which have almost interleaved pattern, computational complexity can be reduced. As results of computer simulation, the proposed shows almost same peak to average power ratio reduction performance as compared to the conventional one. However, computational complexity required to transmit a partial transmit sequence OFDM symbol has been reduced extensively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국해양정보통신학회 2002년도 춘계종합학술대회
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• pp.529-534
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• 2002

It was recommended for all ship engaged in international voyages to carry the dedicated Digital Selective Calling receiver, DSC equipment, VHF transceiver, etc according to Global Maritime Distress & Safety System. Also International Maritime Organization recommended for navigation and communication equipments to applicate the EMC regulations, therefore most of electronic equipments using in the vessel to be faced with problems to cope with new regulations. This study has applied and analyzed the EMC for an equipment integrated with Ch.70 dedicated DSC receiver, DSC equipment, VHF transceiver and groped for solutions to cope with. The test has applied the electromagnetic interference such as the measurement for unwanted emissions from conductive & radio emission and the electromagnetic susceptibility such as the immunity from voltage, frequency variation and electro static discharge, hence comes to be understand the problems related with the power and the earth.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제15권3호
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• pp.719-724
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• 2011

Most recent birth rate at home raising children, only one has come out well. Accordingly, children born to parents is to have a strong interest, and healthcare (Healthcare) sector, while emerging as a new growth industry (Baby Care) Baby Care also increased the interest. Baby Care products until now the food, toiletries and clothing, etc. Although it advances the development of ubiquitous computing environment with the development of the healthcare industry, Baby Care Electronics products have been developed. Europe and the U.S. infant from another room deungeseoneun feeder. At this time SIDS infants to prevent this phenomenon often takes place in order to measure the status of children and away from parents to children, also can check the status of children was used to implement the Platform. In this paper, using the radio frequency real-time observation of data storage without the parents were determined only by the speed of the ARM11-based systems using the S3C6410 CPU and wireless WI-FI (IEEE8.2.11) technology to prevent sudden infant death using Platform for the implementation study was conducted.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제14권4호
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• pp.976-982
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• 2010

Agricultural products are one of the major food, But in recent years, It's not easy for Consumers to buy them. Cause there are not sure about the quality of the cheap foreign agricultural product imported. There are not even sure where they have been produced, Some excessive use of domestic pesticides, And Environmental pollution caused by soil contamination of plantation, It's not only matter with the conscience of the Sellers and producers. The government recommends agricultural producers to attach the mark to identify where the products are made originally. However, if producers do not comply with the recommendation, it become useless. Recently, because of the increased interest to health and food, Consumers want accurate and reliable information about The agricultural products, They buy. In this paper, Based on the RFID technology, RFID tags attached to agricultural products when consumers buy, Through the RFID reader to read RFID tags, Which make Easy to accurately convey Production of agricultural information and safety information to consumers. These features have been implemented with the traceability system.

• Journal of the Institute of Electronics Engineers of Korea TE
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• 제39권2호
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• pp.84-89
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• 2002

In this paper, we present the design method of noise reduction circuit in telephonic system. The circuit consists of compressor, expander and a filter. The basic idea of a proposed method compresses the audible signal in order to mask the channel noise during transmission and then expand at the reverse rate the transmitted signal to naturally recover the original signal. Of course, there should be no distortion or other degradation of the audio itself in passing through companding(compress/expand) cycle. In the compressing process, the gain of compressor is automatically controlled by the envelope level of input signal in order to increase the effective dynamic range of input signal and to improve the signal to noise ratio. The compressed rate is the root time of a audible signal. The compressed signal should be expanded at the square time of the signal to recover a original signal. Simulation shows the proposed method improves the performance of the noise reduction of a channel noise as well as stability. 

• Journal of the Society of Disaster Information
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• 제8권4호
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• pp.419-431
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• 2012

This paper takes precautions proposals against prospective disasters from the space weather maximum in 2013. A geomagnetic space storm sparked by a solar maximum like the one that flared toward earth is bound to strike again and could wreak havoc across the modern world. The purpose of the study is that the disaster reduction and safety service implementation study on the ultimate space weather systems by the information systems of the space weather. The process methods of the study are that an implementation of preparation for the smart IT and GIS based disaster management systems of the solar maximum deal with analysis on the flare, solar proton event, and geomagnetic storm from space blasters, These approach and methods for the solar maximin display national policy implementation of the pattern of the radio wave disasters from the protection and preparation methods. This research can provide affective methods for the saving lives and property protections that implementation of the disaster prediction and disaster prevention systems adapts the smart IT systems and converged decision making support systems using uGIS methodology.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 한국항해항만학회 2009년도 공동학술대회
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• pp.425-431
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• 2009

Recently, new technology has been introducing according to the efforts for maritime safety, traffic and environmental protection that uses electronic method to make use of maritime information effectively. To be associated with the tendance, international society which centered to IALA Introduces advanced technology of AtoN with Automatic Identification System(AIS) that it is crucial method to collect and transmit maritime data. This article is to thoroughly analyse and investigate the international and national regulation of related AtoN AIS, and propose to be included and applied into national radio-communication equipment regulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제24권11호
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• pp.1477-1483
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• 2020

The stability guarantee of wireless network based control systems is still challenging due to the lossy links and node failures. This paper proposes a hierarchical cluster-based network protocol called robust wireless sensor and actuator network (R-WSAN) by combining time, channel, and space resource diversity. R-WSAN includes a scheduling algorithm to support the network resource allocation and a control task sharing scheme to maintain the control stability of multiple plants. R-WSAN was implemented on a real test-bed using Zolertia RE-Mote embedded hardware platform running the Contiki-NG operating system. Our experimental results demonstrate that R-WSAN provides highly reliable and robust performance against lossy links and node failures. Furthermore, the proposed scheduling algorithm and the task sharing scheme meet the stability requirement of control systems, even if the controller fails to support the control task.