• Title/Summary/Keyword: PLCP

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Circuit Design of Frquency Hopping Wireless LAN PLCP Sublayer (주파수 호핑방식 무선 LAN의 PLCP 계층 회로 설계)

  • 최해욱;김경수;기장근;조현묵
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.8
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    • pp.1941-1951
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    • 1998
  • In this paper, hardware circuit that performs functions of IEEE 802.11 wireless LAN frequency hopping PLCP protocol is designed using 0.8 um CMOS cmn8a technology of the COMPASS. Transmission rate of the designed hardware is 1Mbps. The designed circuit have about 6300 gates and $2.5{\times}2.5mm^2$ area. In order to verify the circuit, two PLCP circuits are interconnected and frames are transmitted from one PLCP circuit to the other PLCP circuit. As a results of the simulation, we conclude that the designed PLCP circuit works well as the IEEE 802.11 standard specification.

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The Effect of Phellinus Linteus Cheonghyeol Plus(PLCP) on Antioxidant Activity and Inhibition of Inflammatory Factor Expression Associated with Dyslipidemia in HUVEC (상황청혈플러스(PLCP)가 HUVEC에서 이상지질혈증 관련 항산화 작용 및 염증인자 발현 억제에 미치는 영향)

  • Won, Seo-young;Yoo, Ho-ryong;Seol, In-chan;Kim, Yoon-sik
    • The Journal of Korean Medicine
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    • v.41 no.2
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    • pp.43-57
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    • 2020
  • Objectives: The purpose of this study was to investigate the effect of Phellinus linteus cheonghyeol plus (PLCP) on antioxidant and inhibition of inflammatory factor expression associated with dyslipidemia in HUVEC. Methods: The scavenging activity of DPPH and ABTS radical of PLCP was measured in HUVEC. The expression levels of NF-κB, p-IκBα, ERK, JNK, and p38 proteins were measured after treating with TNF-α in HUVEC. The expression levels of MCP-1, ICAM-1, and VCAM-1 mRNA and biomarkers were measured after treatment with TNF-α in HUVEC Results: 1. PLCP increases DPPH and ABTS radical scavenging activity in a concentration dependent manner. 2. PLCP significantly decreased the concentration of NF-κB, p-IκBα, ERK, JNK protein compared to the control at concentrations of 100 ㎍/㎖ or more, and significantly decreased concentration of p38 protein at all concentrations. 3. PLCP significantly decreased MCP-1 mRNA expression levels at 100㎍/㎖ or more compared to the control. ICAM-1 and VCAM-1 mRNA expression levels were significantly reduced at all concentrations compared to the control. MCP-1, ICAM-1 protein expression levels were significantly reduced compared to the control at concentrations of 100 ㎍/㎖ or more, and VCAM-1 protein expression levels were reduced at all concentrations. Conclusions: These results suggest that PLCP has an antioxidant effect, and it has been experimentally confirmed that it can prevent or inhibit inflammatory diseases caused by dyslipidemia due to its inhibitory effect on inflammation-related factors in HUVEC.

Prevalence and molecular characterization of novel recombinant enterovirus G isolates in Jeju Province of South Korea

  • Jeon, Ji Hyun;Lee, Changhee
    • Korean Journal of Veterinary Research
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    • v.59 no.2
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    • pp.89-96
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    • 2019
  • Enterovirus species G (EV-G) is highly diverse, and is ubiquitous in pig populations, usually without diarrhea. The present study aimed to investigate the presence of novel EV-G recombinants with the torovirus papain-like cysteine protease (PLCP) in Jeju pig herds. EV-G1-PLCP mono-infections were most prevalent in diarrheic weaned piglets. The PLCP genes of the Jeju isolates varied in size and junction sequences, and were greatly heterogeneous, with 77.0-90.7% homology amongst all recombinants. Our results suggest that the exogenous PLCP gene has undergone continuous rapid mutation in the individual EV-G genomes following cross-order recombination, thereby causing clinical disease in swine.

Design of Low-Power and Low-Complexity MIMO-OFDM Baseband Processor for High Speed WLAN Systems (고속 무선 LAN 시스템을 위한 저전력/저면적 MIMO-OFDM 기저대역 프로세서 설계)

  • Im, Jun-Ha;Cho, Mi-Suk;Jung, Yun-Ho;Kim, Jae-Seok
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.11C
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    • pp.940-948
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    • 2008
  • This paper presents a low-power, low-complexity design and implementation results of a high speed multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) wireless LAN (WLAN) baseband processor. The proposed processor is composed of the physical layer convergence procedure (PLCP) processor and physical medium dependent (PMD) processor, which have been optimized to have low-power and reduced-complexity architecture. It was designed in a hardware description language (HDL) and synthesized to gate-level circuits using 0.18um CMOS standard cell library. As a result, the proposed TX-PLCP processor reduced the power consumption by as much as 81% over the bit-level operation architecture. Also, the proposed MIMO symbol detector reduced the hardware complexity by 18% over the conventional SQRD-based architecture with division circuits and square root operations.

A Study on the implementation of PLCP sublayer for Frequency Hopping Wireless LAN (주파수 호핑방식 무선 LAN을 위한 PLCP 부계층 프로토콜 기능 구현 연구)

  • 이선희;기장근
    • Proceedings of the IEEK Conference
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    • 1999.06a
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    • pp.837-840
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    • 1999
  • In this paper, we design and verify the hardware circuit that performs PLCP(Physical Layer Convergence Protocol) protocol functions of physical layer in IEEE 802.11 frequency hopping WLAN(Wireless Local Area Network). Altera MAX+PLUS I $I^{〔1〕}$ is used as a design tool. The designed circuit consists of control register module to interface with upper layer, FIFO module to transmit/receive data with upper layer, TX function module, and RX function module. It is verified that the developed circuit conforms well to the IEEE 802.11 standard specification and can support both 1Mbps and 2 Mbps transmission rate by simulation. The developed circuits can be utilized for the implementation of protocol processor in wireless LAN areas.

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Cloning and Expression of the Cathepsin F-like Cysteine Protease Gene in Escherichia coli and Its Characterization

  • Joo, Han-Seung;Koo, Kwang-Bon;Park, Kyun-In;Bae, Song-Hwan;Yun, Jong-Won;Chang, Chung-Soon;Choi, Jang-Won
    • Journal of Microbiology
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    • v.45 no.2
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    • pp.158-167
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    • 2007
  • In this study, we have cloned a novel cDNA encoding for a papain-family cysteine protease from the Uni-ZAP XR cDNA library of the polychaete, Periserrula leucophryna. This gene was expressed in Escherichia coli using the T7 promoter system, and the protease was characterized after partial purification. First, the partial DNA fragment (498 bp) was amplified from the total RNA via RT-PCR using degenerated primers derived from the conserved region of cysteine protease. The full-length cDNA of cysteine protease (PLCP) was prepared via the screening of the Uni-ZAP XR cDNA library using the $^{32}P-labeled$ partial DNA fragment. As a result, the PLCP gene was determined to consist of a 2591 bp nucleotide sequence (CDS: 173-1024 bp) which encodes for a 283-amino acid polypeptide, which is itself composed of an 59-residue signal sequence, a 6-residue propeptide, a 218-residue mature protein, and a long 3'-noncoding region encompassing 1564 bp. The predicted molecular weights of the preproprotein and the mature protein were calculated as 31.8 kDa and 25 kDa, respectively. The results of sequence analysis and alignment revealed a significant degree of sequence similarity with other eukaryotic cysteine proteases, including the conserved catalytic triad of the $Cys^{90},\;His^{226},\;and\;Asn^{250}$ residues which characterize the C1 family of papain-like cysteine protease. The nucleotide and amino acid sequences of the novel gene were deposited into the GenBank database under the accession numbers, AY390282 and AAR27011, respectively. The results of Northern blot analysis revealed the 2.5 kb size of the transcript and ubiquitous expression throughout the entirety of the body, head, gut, and skin, which suggested that the PLCP may be grouped within the cathepsin F-like proteases. The region encoding for the mature form of the protease was then subcloned into the pT7-7 expression vector following PCR amplification using the designed primers, including the initiation and termination codons. The recombinant cysteine proteases were generated in a range of 6.3 % to 12.5 % of the total cell proteins in the E. coli BL21(DE3) strain for 8 transformants. The results of SDS-PAGE and Western blot analysis indicated that a cysteine protease of approximately 25 kDa (mature form) was generated. The optimal pH and temperature of the enzyme were determined to be approximately 9.5 and $35^{\circ}C$, respectively, thereby indicating that the cysteine protease is a member of the alkaline protease group. The evaluation of substrate specificity indicated that the purified protease was more active towards Arg-X or Lys-X and did not efficiently cleave the substrates with non-polar amino acids at the P1 site. The PLCP evidenced fibrinolytic activity on the plasminogen-free fibrin plate test.

Joint Estimation Schemes of Carrier and Sampling Frequency Offsets for MB-OFDM UWB Systems (MB-OFDM UWB 시스템을 위한 반송파 및 샘플링 주파수 오프셋 결합 추정 기법)

  • Cho, Chang-Hoon;Yang, Suck-Chel;Shin, Yo-An
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.10C
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    • pp.965-975
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    • 2005
  • In this paper, we propose and evaluate joint carrier and sampling frequency offset estimation schemes based on the channel estimation sequences in PLCP (Physical Layer Convergence Procedure) preamble for the proper and effcient synchronization of the MB-OFDM WB (Multi-Band Orthogonal Frequency Division Multiplexing Ultra Wide Band) systems which have recently drawn explosive attention for future W-PAN (Wireless Personal Area Network) applications. In the joint estimation schemes, we first estimate the sampling frequency offset, and then estimate the carrier frequency offset using the estimated sampling frequency offset. Moreover, to improve the reliability of the estimated offset values, each process uses a combination scheme based on weighting factors. Simulation results using IEEE 802.15 Task Group 3a UWB channel models reveal that the estimation scheme using the simple weighting factors based on easily-measurable received signal power of each sub-channel shows favorably comparable performance to the ideal scheme using the weighting factors based on the perfectly-estimated frequency response of the channel.

A study on the Channel Estimation Scheme in IEEE 802.11 Based System (IEEE 802.11 기반 시스템에서 채널추정에 관한 연구)

  • Kim, Hanjong
    • Journal of Digital Convergence
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    • v.12 no.3
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    • pp.249-254
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    • 2014
  • Wireless LAN system is evolving toward high-speed data transmission and more accurate channel estimation is necessarily required to improve communication performance. The PLCP preamble field in IEEE 802.11 based wireless MODEM consists of ten short symbols and two long symbols and is used for synchronization and channel estimation. The existing least square (LS) channel estimation is based on only two long training symbols. After estimating channel response separately by using each long training symbol, the final channel estimation is obtained by the average of each estimation. In this paper, a new channel estimation algorithm is presented to improve the performance of the existing LS channel estimation algorithm. From the fact that the short training symbol consists of 12 non-zero subcarriers, it gives us a clue of being able to additionally estimate at least one fourth of channel coefficients. The new LS algorithm performs channel estimation based on both two long training symbols and a short training symbol. The proposed LS algorithm shows a little bit performance improvement over the existing LS estimation and it will be able to be applied to the IEEE 802.11p WAVE system.

Performance Evaluation of Signal Detection Algorithms for MB-OFDM (MB-OFDM을 위한 신호 획득 알고리즘 성능 평가)

  • Kim, Hae-Lyong;Lee, Yu-Sung;Park, Hyun-Cheol
    • Proceedings of the IEEK Conference
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    • 2004.06a
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    • pp.15-18
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    • 2004
  • A high data rate Wireless Personal Area Networks (WPAN) system is a hot issue in wireless communication communities and being standardized. Multi-band Orthogonal Frequency Division Multiplexing (MB-OFDM) is one of the candidates for WPAN standard. In this paper, we discuss the PLCP (Physical Layer Convergence Protocol) structure for MB-OFDM. Also we evaluate the performance of two signal detection algorithms, which are the method of cross-correlation with the original preamble and the signed preamble. The latter has a low complexity with a little degradation.

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