• Proceedings of the Korean Information Science Society Conference
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• 2010.06d
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• pp.185-189
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• 2010

IEEE 802.15.4는 저전력 무선 개인 네트워크(LR-WPAN, Low Rate-Wireless Personal Area Network)를 위한 표준으로 무선 센서 네트워크 기술에서 광범위하게 사용되고 있다. 그러나 IEEE 802.15.4는 멀티홉 네트워크나 여러 개의 PAN(Personal Area Network)으로 구성된 네트워크에 대해서는 상세하게 기술하고 있지 않다. 본 논문에서는 IEEE 802.15.4를 기반으로 하는 ZigBee RF4CE 네트워크에서 사용하는 multiple star 토폴로지를 주목하였다. multiple star 토폴로지처럼 여러 개의 PAN 간에 통신이 이루어질 경우, 이를 에너지 효율적으로 수행할 수 있도록 하는 비컨 간격(Beacon Interval)과 슈퍼프레임 시간(Superframe Duration)을 분석한다. 이를 위해 QualNet 시뮬레이터를 이용하여 multiple star 토폴로지 네트워크를 형성하고, 비컨 간격과 슈퍼프레임 시간을 결정하는 요소에 대해 분석하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.5B
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• pp.310-317
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• 2008

Data collision in LR-WPAN(Low Rate Wireless Personal Area Network) causes retransmission of which energy consumption may reduce life of the entire network. Furthermore LR-WPAN is very sensitive to collision as it has relatively fewer frequencies of backoff retries. LCS(Limited Contention Scheme) suggested in this study is a way to transmit data by certain groups of the total nodes so that it can reduce possibilities of data collision and retransmission by decreasing the number of competing nodes. As a result LCS can increase a throughput and the life of the entire network. As using LCS in designing LR-WPAN in the future can extend battery life, LCS can be useful in any application that requires low energy consumption.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.6
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• pp.1128-1133
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• 2008

Context-aware computing has been attracting the attention as an approach to alleviating the inconvenience in human-computer interactions. This paper proposes a context-aware system architecture to be implemented on an UoC (Ubiquitous system on Chip). A new proposed technology of CRS (Context Recognition Switch) and DOS (Dynamic and Optimal Standard) based on Context-awareness system architecture with pre-processor, HPSP(High Performance Signal Processor) in this paper. And proposed a new algorithm using in network topology processor shows for Ubiquitous Computing System. implementing in UoC (Ubiquitous System on Chip) base on the IEEE 802.15.4 WPAN (Wireless Personal Area Network) standard. Also, This context-aware based UoC architecture has been developed to apply to mobile intelligent robots which would support human in a context-aware manner.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.1
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• pp.7-13
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• 2011

A mixed-mode QPSK demodulator for 60-GHz wireless personal area network application is demonstrated. In this work, mixed-mode QPKS demodulation scheme achieving low power consumption and small area is employed. The prototype chip realized by 60-nm CMOS Logic process can demodulate up to 4.8-Gb/s QPSK signals at 4.8-GHz carrier frequency. At this carrier frequency, the demodulator core consumes 54 mW from 1.2-V power supply while the chip area is $150{\times}150{\mu}m^2$. Using the fabricated chip, transmission and demodulation of 1.7-GSymbol/s QPSK signal in 60-GHz link is demonstrated.

• Journal of Biomedical Engineering Research
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• v.14 no.4
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• pp.327-332
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• 1993

Automatic transmission of data from the blood analyzer to the request site is one of the most important part in hospital computerization. We have developed a system that transmits data from the arterial blood gas analyzer to the request site automatically In this system HOST computer, FILE server,'LAN(Local Area Network) , 3270 Emulator and bfulti-port card are integrated with 3 blood gas analyzers(NOVA Inc., USA) which are connected to a single multi-port card in a personal computer. When specimen are collected from tramp)inly sites, they are transferee to the laboratory In the Yonsei Cardiovascular Center After analysis, the result is transmitted to the personal computer via serial commnunication between machine and multi-port card using interrupt method. Then, the patient's information (Name, Patient ID No., etc.) is obtained from the HOST computer througth the emulator. The combined data (patient information & lab data) is transmitted to each request site via LAN automatically These results are stored in the File Server for one year and they can be reviewed anytime. Also, it could be used for the various statistics and the flow chart for clinical research. Additionally, we found thal this system reduces the personal labor.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.1923-1930
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• 2012

'No-Automobile driving Day' is one of Special option of Automobile Insurance in Republic of Korea. It option is used a system for collect to automobile driving information. However, Its system gives discomfort to users of this system. A Discomfort of this system to users is the OBD device's(Personal Car Driving Check Device) installation. A frequent installation of this device provides this OBD device's breakage to the users of this system. In this paper, for a solve this problem, studied new system design to supplement the existing system using Smartphone and WPAN(Wireless Personal Area Network).

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.7
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• pp.85-92
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• 2010

In this paper, we consider the orthogonal frequency division multiplexing (OFDM) based transmission incoorperating with beam-switching and space-time coding. Specifically, we consider three configurations; (1) the beamforming technique, (2) the spatial diversity technique and (3) their combination and evaluate the performance in wireless personal area network (WPAN) environment. For the beam-forming technique, we consider the beam-switching which is performed at RF front-end with a pre-defined set of beams and for the space-time coding, we consider the Alamauti scheme with antenna selection. For the combined scheme, we divide the antennas used into two group to generate two independent beams and apply the two-antenna Alamauti scheme over the two beams. For these three configurations, performance is evaluated in terms of the SNR gain.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.7
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• pp.372-379
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• 2014

When a hand-held device with limited battery transmits and receives data using short-range wireless communication systems, such as WLAN(Wireless Local Area Network) or high speed WPAN(Wireless Personal Area Network), instead of mobile communication systems, the device is able to reduce the power consumption due to the reduced transmission distance. However, if there are many WLAN or high speed WPAN systems around the device, non-negligible power may be consumed by receiving and decoding the packets which have nothing to do with the device. In this paper, we propose a scheme reducing the power consumption by including physical-layer ID in WLAN or WPAN packets and avoiding unnecessary packet receptions. Also, we describe a method to determine the optimum number of physical-layer IDs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.43-49
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• 2019

The wired and wireless Internet is a useful window to easily acquire various types of media data. On the other hand, the public can easily get the media data including the object to which the personal information is exposed, which is a social problem. In this paper, we propose a method to robustly detect a target object that has exposed personal information using a learning algorithm and effectively block the detected target object area. In the proposed method, only the target object containing the personal information is detected using a neural network-based learning algorithm. Then, a grid-like mosaic is created and overlapped on the target object area detected in the previous step, thereby effectively blocking the object area containing the personal information. Experimental results show that the proposed algorithm robustly detects the object area in which personal information is exposed and effectively blocks the detected area through mosaic processing. The object blocking method presented in this paper is expected to be useful in many applications related to computer vision.

• The KIPS Transactions:PartC
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• v.11C no.2
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• pp.219-228
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• 2004

Wireless LAN(wireless Local Area Network) is constructed network environment by radio in indoors or outdoors environment and that to use electric wave or light instead of wire to client such as PC(Personal Computer), notebook, PDA in hub(Hub) in technological side. Now, among IEEE 802.11 WG(Working Group), there is TGf(Task Group F) that develop standard protocol between AP's(Access Point). In this group, proposed IAPP(Inter Access Point Protocol) to secure interoperability between AP producing in different manufacturer, this offers seamless connectivity between STA by sharing Security Context information or Layer 2 forwarding information between AP without passing through re-authentication process when STAs(Station) move by protocol to secure mobility between AP that differ in equal serve network. In this paper, I wish to suggest method that change avenue of communication of message to block information leakage that can occur at security message or WEP Key transmission between above AP, and uses public key to offer wireless area security little more.