• Title/Summary/Keyword: 802.15.6

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Disign of Non-coherent Demodulator for LR-WPAN Systems (LR-WPAN 시스템을 위한 비동기 복조 알고리즘 및 하드웨어 구조설계)

  • Lee, Dong-Chan;Jang, Soo-Hyun;Jung, Yun-Ho
    • Journal of Advanced Navigation Technology
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    • v.17 no.6
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    • pp.705-711
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    • 2013
  • In this paper, we present a low-complexity non-coherent demodulation algorithm and hardware architecture for LR-WPAN systems which can support the variable data rate for various applications. The need for LR-WPAN systems that can support the variable data rate is increasing due to the emergence of various sensor applications. Since the existing symbol based double correlation (SBDC) algorithm requires the increase of complexity to support the variable data rate, we propose the sample based double correlation (SPDC) algorithm which can be implemented without the increase of complexity. The proposed non-coherent demodulator was designed by verilog HDL and implemented with FPGA prototype board.

Biological Characteristics and Growth of the Korean Freshwater Rotifer, Brachionus calyciflorus at Various Temperatures (한국 담수산 윤층 Brachionus calyciflorus의 생물학적 특징과 온도별 성장)

  • 강언종;이배익;김응오
    • Journal of Aquaculture
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    • v.10 no.4
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    • pp.449-456
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    • 1997
  • This study was concuted to determine the optimal conditions for raising the freshwater rotifer, Brachinus calyciflorus. The authors presented some biological informatin obtained from incubation experiment under the various controlled temperatures. Lorica size of the rotifer was divided into two groups : the length and the width for the S-type was $141.0\pm16.7\mu m$($110.1-182.5\;\mu m, n=44$)and $107.0\pm20.3\mu m\;(75.3-152.3\mu m, n=44)$, and those for the L-type was $262.8\pm15.2\mu m\;(234.4-288.6\mu m,\;n=20)\;and\;182.6\pm13.4\mu m (159.8-207.0\mu m,\;n=20$), respectively. The number of eggs being attached on the female varied from 1 to 11 at various culture conditions. Egg type was divided into two groups, large and small. Large and small egg was measured in its major axis as 85a.7-107.8$\mu$m and 55.1-65.2$\mu$m for S-type, and 104.9-121.8 $\mu$m and 62.8-89.1$\mu$m for L-type respectively. The maximum density was reached at 4th day after incubation. The density was 583.9 rotifers/$m\ell$ for $25^{\circ}C$-experimental. group and 421.3 rotifers/$m\ell$ for $22^{\circ}C$-experimental. group respectively. In the case of $28^{\circ}C$-experimental. group, it suddenly decreased into 4.7 rotifers/$m\ell$ at 1st day after incubations and did not recover to its initial density. The maximum rate of increase of populatin per day was reached 0.802 for $22^{\circ}C$-experimental. group at day 2 and fluctuated thereafter. For $25^{\circ}C$-experimental. group it increased to 0.964 at day 3 of incubation and then declined. And the egg ratio of female was reached the maximum of 0.614 for 22$^{\circ}C$- at 3rd day and 0.772 for $25^{\circ}C$-experimental. group at 4th day of incubation.

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Low-power 6LoWPAN Protocol Design (저 전력 6LoWPAN 프로토콜 설계)

  • Kim, Chang-Hoon;Kim, Il-Hyu;Cha, Jung-Woo;Nam, In-Gil;Lee, Chae-Wook
    • Journal of the Institute of Convergence Signal Processing
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    • v.12 no.4
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    • pp.274-280
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    • 2011
  • Due to their rapid growth and new paradigm applications, wireless sensor networks(WSNs) are morphing into low power personal area networks(LoWPANs), which are envisioned to grow radically. The fragmentation and reassembly of IP data packet is one of the most important function in the 6LoWPAN based communication between Internet and wireless sensor network. However, since the 6LoWPAN data unit size is 102 byte for IPv6 MTU size is 1200 byte, it increases the number of fragmentation and reassembly. In order to reduce the number of fragmentation and reassembly, this paper presents a new scheme that can be applicable to 6LoWPAN. When a fragmented packet header is constructed, we can have more space for data. This is because we use 8-bits routing table ill instead of 16-bits or 54-bits MAC address to decide the destination node. Analysis shows that our design has roughly 7% or 22% less transmission number of fragmented packets, depending on MAC address size(16-bits or 54-bits), compared with the previously proposed scheme in RFC4944. The reduced fragmented packet transmission means a low power consumption since the packet transmission is the very high power function in wireless sensor networks. Therefore the presented fragmented transmission scheme is well suited for low-power wireless sensor networks.

Effects of Roughage Feeding Type during the Growing and Early-Fattening Periods on Growth Performance, Feed Efficiency and Carcass Characteristics in Holstein Steers (육성 및 비육전기의 조사료 급여형태가 홀스타인 거세우의 성장 발육, 사료이용성 및 도체특성에 미치는 영향)

  • Kang, S.W.;Ki, K.S.;Oh, Y.K.;Kim, K.H.;Choi, C.W.
    • Journal of Animal Science and Technology
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    • v.47 no.5
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    • pp.769-782
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    • 2005
  • Twenty four Holstein steers fed commercial concentrates with rice straw(T1), mixed grass hay(T2), or wet brewer’s grains based TMR ad libitum(T3) were used to investigate the effects of roughage feeding type during the growing and early-fattening periods on growth performance, feed efficiency and carcass characteristics. Growth performance and feed efficiency were investigated during the feeding trial conducted from 6 to 23 mo of age, and carcass characteristics were investigated after slaughter. Body weight at slaughter and daily gains were 751 to 802 kg(mean 782 kg) and 1.064 to 1.159 kg/d(mean 1.122 kg/d), respectively, showing that those for T2 were highest followed by T3. Compared with T1, the daily gain for T2 was improved by 8.9%. The TDN intakes per kg gain were 6.87, 7.17 and 7.15 kg for T1, T3 and T2, respectively, indicating that feed efficiency for T2 was improved(approx. 5%) compared with T1. The feeding treatments did not change dressing percentage(mean 60.8%), back fat thickness(6.68 mm) and rib-eye area(84.0$cm^2$). Neither meat quality characteristics nor physicochemical properties were significantly different among the treatments. However, economic analysis accounting for 882.8, 991.7 and 943.8 thousand won per head for T1, T2 and T3, respectively, indicated that T2 and T3 increased(7-12%) total net income compared with T1. Therefore, it may be concluded that high quality meat of Holstein steers can be produced if they are fattened until 23 mo of age and that feeding mixed grass hay as roughage or TMR containing mainly wet brewer's grains during the growing and early-fattening periods can improve growth performance compared with feeding rice straw.

Buffer Management Algorithm for Performance Improvement in WBAN (WBAN 환경에서 성능향상을 위한 버퍼 관리 알고리즘)

  • Kim, JiWon;Kim, Kanghee;Lee, ChangHo;Choi, SangBang
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.5
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    • pp.106-114
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    • 2015
  • Wireless Body Area Network(WBAN) is a network standard around a human body which connects various medical sensor and devices It has to satisfy various demands such as data transmission rate, priority, and delay time. In this paper, considering a data priority and transmission delay time, is proposed to improve efficiency of WBAN service depending on congestion status of network. The proposed algorithm operates with adapted data removal probability according to data priority when the hub buffer is congested than before. And in the case of lower congestion within the hub buffer data is served considering data delay time. Through the comparison with other existing scheduling algorithms, it is confirmed that quality of WBAN service is improved due to lower data loss rate of medical data and less delay time in the proposed algorithm.

A Prediction Model on Korean Medicine Health Promotion Behavior in Late Adulthood-Elderly (국내 수도권 중·노년층의 한방건강증진행위 예측모형)

  • Kim, Soo-Kyung;Choi, Hyung-Wook;Woo, Won-Hong
    • Journal of Society of Preventive Korean Medicine
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    • v.19 no.2
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    • pp.1-12
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    • 2015
  • Objective : This study was a covariance structural analysis to identify korean medicine health promotion behavior by the general characteristics of the subjects and build a predictive model and theoretical framework based on Pender's health promotion model(1996) and related literature reviews. Method : A hypothetical model was consisted of 8 theoretical variables and 27 measured variables. Related variables included Individual Characteristics and Experience, Behavior-specific cognitions and affect and Behavioral outcome. The data was collected from 802 middle and old-aged people living in Seoul and Gyeong gi province through structured questionnaires by face to face interviews between February and March, 2014. SAS ver. 9.1 and AMOS 18.0 programs were used for the data analysis. Results : Difference in the verification of Korean medicine health promotion behavior by the general characteristics, Older people who are male, with higher economic status, no chronic disease or with diabetes, no smoking, no drinking, with more exercise showed significantly higher scores, but education level has no difference. 15 paths were statistically significant among 16 paths on the direct effect, 6 paths were statistically significant among 9 paths on the indirect effect in the hypothetical model. The greatest impact variable on Korean medicine health promotion behavior was perceived self-esteem. Also, the findings showed that the higher perceived social support, perceived health status, previous Korean medicine health promotion behavior, community environment, perceived benefit and the lower perceived barrier had a significant effect on Korean medicine health promotion behavior. Conclusion : This research model has an empirical validity as the variables of this study verified their effects and significances. Therefore, the understanding of Korean medicine health promotion behavior can be increased and the utilization will be higher when seeking a comprehensive health promotion plan. Also, a strategy can be utilized the strategy for Korean medicine health promotion behavior.

Generation and Distribution of Symmetric/Asymmetric Secret Keys for Secure Communications in Koinonia High-rate WPAN (Koinonia 고속 WPAN에서 보안을 위한 대칭/비대칭 비밀 키 교환 방법)

  • Yim Soon-Bin;Jung Ssang-Bong;Lee Tae-Jin;June Sun-Do;Lee Hyeon-Seok;Kwon Tai-Gil;Cho Jin-Woong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.6B
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    • pp.551-560
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    • 2006
  • Security in WPAN is one of the most fundamental issues to overcome the barrier of wireless environment. Although piconet security mechanisms have been defined in the WPAN standards, many remains open and are left for implementation. Koinonia is a high-rate Wireless Personal Area Network (WPAN) technology, and is developed for multimedia traffic transmission in personal area. In Koinonia WPAN, a piconet consists of one master and more than one slave, and piconet security mechanisms is not defined at all. Therefore, we propose a robust piconet security mechanism for secure communications between slaves in a piconet. Based on security requirements analysis, our proposed protocols are shown to meet the security needs for Koinonia high-rate WPAN.

Environment Adaptive WBAN Routing based on Residual energy (에너지량에 기반한 환경 적응 WBAN 라우팅 알고리즘)

  • Kim, Wee-Yeon;Kim, Dae-Young;Shin, Sang-Bae;Cho, Jin-Sung
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.1
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    • pp.89-99
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    • 2011
  • In this paper, we propose an routing algorithm for ultra low power and high reliable transmission in WBAN environment. This algorithm is to minimize energy consumption and to maximize the life and reliability for medical devices. Also, this algorithm is not only medical devices but also non-medical devices is to minimize energy consumption and to maximize the life of device. The combination of the distance from the previous node and residual energy calculates weight. The calculated weight is used to calculate the weight of full path by cumulative weights. The full path to the smallest of the weights are set to the path. Also this algorithm is able to select another path to avoid the error path by determining the link status between nodes, when occurs link error and congestion. In this paper, we show that WSN routing algorithm based on shortest hop count routing algorithm and EAR routing algorithm compared to ensure high reliability and low power characteristic of WBAN to be verified through simulations.

V-Band Power Amplifier MMIC with Excellent Gain-Flatness (광대역의 우수한 이득평탄도를 갖는 V-밴드 전력증폭기 MMIC)

  • Chang, Woo-Jin;Ji, Hong-Gu;Lim, Jong-Won;Ahn, Ho-Kyun;Kim, Hae-Cheon;Oh, Seung-Hyueb
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.623-624
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    • 2006
  • In this paper, we introduce the design and fabrication of V-band power amplifier MMIC with excellent gain-flatness for IEEE 802.15.3c WPAN system. The V-band power amplifier was designed using ETRI' $0.12{\mu}m$ PHEMT process. The PHEMT shows a peak transconductance ($G_{m,peak}$) of 500 mS/mm, a threshold voltage of -1.2 V, and a drain saturation current of 49 mA for 2 fingers and $100{\mu}m$ total gate width (2f100) at $V_{ds}$=2 V. The RF characteristics of the PHEMT show a cutoff frequency, $f_T$, of 97 GHz, and a maximum oscillation frequency, $f_{max}$, of 166 GHz. The gains of the each stages of the amplifier were modified to have broadband characteristics of input/output matching for first and fourth stages and get more gains of edge regions of operating frequency range for second and third stages in order to make the gain-flatness of the amplifier excellently for wide band. The performances of the fabricated 60 GHz power amplifier MMIC are operating frequency of $56.25{\sim}62.25\;GHz$, bandwidth of 6 GHz, small signal gain ($S_{21}$) of $16.5{\sim}17.2\;dB$, gain flatness of 0.7 dB, an input reflection coefficient ($S_{11}$) of $-16{\sim}-9\;dB$, output reflection coefficient ($S_{22}$) of $-16{\sim}-4\;dB$ and output power ($P_{out}$) of 13 dBm. The chip size of the amplifier MMIC was $3.7{\times}1.4mm^2$.

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A Study on Advanced RF4CE Key Agreement for Device Convergence Security (디바이스 융합 보안을 위한 향상된 RF4CE 키 교환 기법에 관한 연구)

  • Shon, Tae-Shik;Koo, Bon-Hyun;Han, Kyu-Suk
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.6B
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    • pp.970-976
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    • 2010
  • Platform convergence originated from the convergence of broadcast and telecommunication is making rapid progress including IT and not-IT fields in order to provide a variety of converged services, S/W eco-system construction, and so on. With the advent of convergence environment, IEEE 802.15.4-based RF4CE technology is rising because of creating momentum for the market using converged connectivity between home and office devices as well as all around located devices. In this paper, we present enhanced RF4CE key seed distribution approach in order to provide efficient connection and control between devices. The proposed approach consists of device mutual authentication, initial vector assignment, and two-phase key seed distribution. Moreover, we make a development real RF4CE test board and its key agreement simulator to verify the proposed approach.