• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.975-978
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• 2005

The RFID(Radio Frequency Identification) technology is a non-contact identification system which can wireless reading of information, by attaching tags on objects; various applications of the technology are feasible throughout a diversity of industries, and researches are currently under way. Recently, in connection with the wireless communication industry, application service models conveying information to the users through mobile devices with RFID readers were suggested. Such application service based on mobile RFID technology requires schema that models the form of data. Therefore, this study analyses the mobile RFID application service model that will be serviced in the mobile environment, functions and elements of the protocol, and the interface, designing a language to process the data and express contents in the said service models.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.459-462
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• 2009

The Growth in wireless Internet has made Networking possible at anytime and anywhere so that application program development is vigorous for mobile service implementation. In particular, mobile service has a feature that can present flexible service at anytime, and anywhere. This study proposes a system which is able to make a remote control of computer by means of mobile as an example of the production of application for such mobile service. This paper researches a RDP(Remote Desktop Protocol), VNC(Virtual Network Computing) system that control screen of remote computer and input devices by using smart-phone. The advantage of this system is the function that turning on and off the computer, file transfer, file upload/download, and paperwork. Therefore users are expected to use more conveniently.

• Journal of the Korea Institute of Building Construction
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• v.21 no.1
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• pp.21-29
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• 2021

The objective of this study is to evaluate the effect of the application of double layered bubble sheet on the curing of slab and wall concrete placed at the job site in cold weather and to offer a feasibility of Concrete IoT Management System(CIMS), which is wireless sensor network developed by the authors, to manage early age quality of the concrete in terms of temperature, maturity and strength development. Test results indicated that the application of bubble sheet enhances the insulation performance, which results in an increase of the temperature by around 1~20. 6℃. It is found that CIMS can gather the temperature, maturity and strength development data from the sensors embedded from 30 m far from CIMS successfully. Predicted compressive strengths by CIMS had good agreement with measured ones within 2 MPa error level until 7 days. It is thought that the combination of the bubble sheet application for cold weather protection and CIMS for quality management tool in cold weather concreting contributes to shorten the time for the form removal by one day.

• Journal of KIISE:Information Networking
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• v.34 no.6
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• pp.446-457
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• 2007

In wireless sensor network, to provide the proper responses quickly for diverse events, wireless sensor nodes have to cooperate with each other. For successful cooperation, the time synchronization among sensor nodes is an important requirement for application execution. In the wireless sensor network, the message packets including time information are used for the time synchronization. However, the transmission of many message packets will exhaust the battery of wireless sensor nodes. Since wireless sensor nodes works on the limited battery capacity, the excessive transmission of message packets has an negative impact upon their lifetime. In this paper, the Reference Interpolation Protocol (RIP) is proposed to reduce the number of message packets for the time synchronization. The proposed method performs the time interpolation between the reference packet's time and the global time of the base station. The proposed method completes the synchronization operation with only 2 message packets when compared to the previous Reference Broadcast Synchronization (RBS) technique. Due to the simple synchronization procedure, our method greatly reduces the number of synchronization messages and showed the 12.7 times less power consumption than the RBS method. From the decrease in the transmission of message packets, the convergence time among wireless sensor nodes is shortened and the lifetime of wireless sensor nodes is also prolonged as much as the amount of saved battery energy.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.1 s.343
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• pp.79-88
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• 2006

In this paper, we designed and implemented ubiquitous u-Health system using RFE and ZigBee. We made a wireless protocol Kit which combines RFE Tag recognition and ZigBee data communication capability. The software is designed and developed on the TinyOS. Wireless communication technologies which hold multi-protocol stacks with RFID and result in the wireless ubiquitous world could be Bluetooth, ZigBee, 802.11x WLAN and so on. The environments that the suggested u-Health system may be used is un-manned nursing, which would be utilized in dense sensor networks such as a hospital. The the size of devices with RFID and ZigBee will be so smaller and smaller as a bracelet, a wrist watch and a ring. The combined wireless RFID-ZigBee system could be applied to applications which requires some actions corresponding to the collected (or sensed) information in WBAN(Wireless Body Area Network) and/or WPAN(Wireless Person Area Network). The proposed ubiquitous u-Health system displays some text-type alert message on LCD which is attached to the system or gives voice alert message to the adequate node users. RFE will be used as various combinations with other wireless technologies for some application-specific purposes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.7
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• pp.3220-3226
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• 2011

In order to monitor internal risk factors such as fire, terror, etc. on the subway station, the surveillance systems using CCTV and various kinds of sensors have been implemented and recently, introduction of surveillance systems using an advanced IT technology, sensor network technology is tried on several areas. Since 2007, Korean government has made an effort to develop the intelligent surveillance and monitoring system, which can monitor fire, intrusion, passenger congestion, health-state of structure, etc., by using wireless sensor network technology and intelligent video analytic technique. For that purpose, this study carried out field wireless communication environment test on Chungmuro Station of Seoul Metro on the basis of ZigBee that is considered as a representative wireless sensor network before field application of the intelligent integrated surveillance system being developed, arranged and analyzed and ZigBee based wireless communication environment test results on the platform and waiting room of Chungmuro Station on this paper. Results of wireless spectrum analysis on the platform and waiting room showed that there is no radio frequency overlapped with that of ZigBee based sensor network and no frequency interference with adjacent frequencies separated 10MHz or more. As results of wireless data transmission test using ZigBee showed that data transmission is influenced by multi-path fading effect from the number and flow rate of passengers on the platform or the waiting room rather than effects from entrance and exit of the train to/from the platform, it should be considered when implementing the intelligent integrated surveillance system on the station.

• Journal of Advanced Navigation Technology
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• v.11 no.4
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• pp.423-429
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• 2007

Since the wireless smart card has played a main role in the identification security application for the building access; this research has its purpose to improve the performance of the smart card system and aims to offer more convenient to user. The contactless cards do not require insertion into a card reader and can work up to centimeters away from the reading device. To be able to cope with this performance the controlling of power consumption through the adaptive modulation and error control is needed. This paper addresses a forward error control (FEC) scheme with the adaptive Reed-Solomon code rate and an M-ary frequency shift keying (M-FSK) modulation scheme with the varying symbol size M over the link. The result of comparing energy efficiencies of adaptive error correction and adaptive modulation to other various static schemes shows to save over 50% of the energy consumption.

• Journal of Korea Multimedia Society
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• v.17 no.8
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• pp.977-987
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• 2014

Many of the recent performance evaluation of clustering schemes in wireless sensor networks considered one sink node operation and fixed sink node location without mentioning about any network application requirements. However, application environments have variable requirements about their networks. In addition, network performance is sufficiently influenced by different sink node location scenarios in multi-hop based network. We also know that sink location can influence to the sensor network performance evaluation because of changed multipath of sensor nodes and changed overload spots in multipath based wireless sensor network environment. Thus, the performance evaluation results are hard to trust because sensor network is easily changed their network connection through their routing algorithms. Therefore, we suggest that these schemes need to evaluate with different sink node location scenarios to show fair evaluation result. Under the results of that, network performance evaluation results are acknowledged by researchers. In this paper, we measured several clustering scheme's performance variations in accordance with various types of sink node location scenarios. As a result, in the case of the clustering scheme that did not consider various types of sink location scenarios, fair evaluation cannot be expected.

• Smart Structures and Systems
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• v.12 no.1
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• pp.23-39
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• 2013

In this article, a smart multifunctional optical system-on-a-chip (SOC) sensor platform is presented and its application for fiber Bragg grating (FBG) sensor interrogation in optical sensor networks is investigated. The smart SOC sensor platform consists of a superluminescent diode as a broadband source, a tunable microelectromechanical system (MEMS) based Fabry-P$\acute{e}$rot filter, photodetectors, and an integrated microcontroller for data acquisition, processing, and communication. Integrated with a wireless sensor network (WSN) module in a compact package, a smart optical sensor node is developed. The smart multifunctional sensor platform has the capability of interrogating different types of optical fiber sensors, including Fabry-P$\acute{e}$rot sensors and Bragg grating sensors. As a case study, the smart optical sensor platform is demonstrated to interrogate multiplexed FBG strain sensors. A time domain signal processing method is used to obtain the Bragg wavelength shift of two FBG strain sensors through sweeping the MEMS tunable Fabry-P$\acute{e}$rot filter. A tuning range of 46 nm and a tuning speed of 10 Hz are achieved. The smart optical sensor platform will open doors to many applications that require high performance optical WSNs.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.479-482
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• 2012

WiBro(Wireless Broadband) service is the world standardized fourth-generation communications in Korea. The services through internet-based applications using WiBro communication-based is increasing. WiBro service in the Internet-based applications when using the service, the application may need to analyze the vulnerability. In this paper, we use the Internet when in WiBro service, to analyze the vulnerability. And, Internet-based applications for vulnerabilities that could lead to hacker attacks is analyzed. It will be studied that security measures through analysis of vulnerability of WiBro services and applications.