• Title/Summary/Keyword: NTP

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A standardization of AGNSS-Packet Timing Hybrid for a Synchronization of Femtocell (펨토셀 기지국 동기 획득을 위한 AGNSS-Packet Timing 하이브리드 표준화)

  • Kim, Jung-Hoon;Lee, Ji-Hun;Shin, Jun-Hyo;Jeong, Seok-Jong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.12B
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    • pp.1611-1622
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    • 2011
  • The synchronization is one of the important issues for successful operation of femtocell. The synchronization of femtocell is distinctly different from that of larger wireless base stations in a number of important respects such as 1) The femtocell is located in indoor environment which may make it difficult to receive the adequate GNSS signals. 2) The backhaul of femtocell is connected to the public network which may have more PDV than private network. 3) The entire cost of femtocell needs to be very low. In our thesis, we investigate the candidate solutions including AGNSS (Assisted GNSS), NTP (Network Time Protocol), PTP (Precision Timing Protocol) and Cellular Network Listen for indoor timing solution. We propose the AGNSS-PTP Hybrid scheme which can improve time and frequency quality by selecting the better reference between AGNSS and PTP, and cover the standard status which are under discussion from IEEE, ITU-T, and IETF.

Examination of Parameters Affecting Polymerase Chain Reaction in Studying RAPD (PCR에 의한 RAPD marker들의 증폭에 영향을 주는 조건들에 대한 고찰)

  • Yoon, Cheol-Sik
    • The Korean Journal of Mycology
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    • v.20 no.4
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    • pp.315-323
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    • 1992
  • The effects of several parameters on PCR amplification in using RAPD were studied. The results of this study suggest that approximately 15 ng of genomic DNA in $20\;{\mu}l$ of reaction mixture results in discrete and reproducible PCR products. In addition, the results indicate that concentration or amounts of reaction components studied are highly inter-dependent in their effects, and RNA can interfere severely with PCR amplification. Suitable concentrations or amounts of reaction components were found to be 30 ng of 10-mer primer, $200\;{\mu}M$ of dNTP, 0.001% gelatin 1.5 mM $MgCl_2$, 10 mM Tris-Cl (pH 8.8), 50 mM KCl, 0.1% Triton X-100, 2 units of Taq DNA polymerase, and 15 ng of RNase-treated genomic DNA in $25\;{\mu}l$ of reaction mixture.

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Real Time Scale Measurement of Inorganic Phosphate Release by Fluorophore Labeled Phosphate Binding Protein (형광단이 붙어 있는 인산결합 단백질에 의한 인산 배출의 실시간 측정)

  • Jeong Yong-Joo
    • Journal of Life Science
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    • v.15 no.6
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    • pp.935-940
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    • 2005
  • Fluorescence change of coumarin labeled phosphate binding protein (PBP-MDCC) was monitored to measure the amount of released inorganic phosphate ($P_{i}$) during nucleoside triphosphate (NTP) hydrolysis reaction. After purification of PBP-MDCC, fluorescence emission spectra showed that fluorescence responded linearly to $P_{i}$ up to about 0.7 molar ratio of $P_{i}$ to protein. The correlation of fluorescence signal and $P_{i}$ standard was measured to obtain [$P_{i}$] - fluorescence intensity standard curve on the stopped-flow instrument. When T7 bacteriophage helicase, double-stranded DNA unwinding enzyme using dTTP hydrolysis as an energy source, reacted with dTTP, the change of fluorescence was able to be converted to the amount of released $P_{i}$ by the $P_{i}$ standard curve. $P_{i}$ release results showed that single-stranded Ml3 DNA stimulated dTTP hydrolysis reaction several folds by T7 helicase. Instead of end point assay in NTP hydrolysis reaction, real time $P_{i}$-release assay by PBP-MDCC was proven to be very easy and convenient to measure released $P_{i}$.

The Production of HBsAg in the Recombinant Yeast Cells (재조합 효모 세포내에서의 간염백신 생산)

  • Park, Cha-Yong;Lee, Hei-Chan
    • Microbiology and Biotechnology Letters
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    • v.14 no.6
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    • pp.455-460
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    • 1986
  • Dane particle was prepared from the plasma of chronic HBsAg carrier with high levels of HBsAg activity. DNA extracted front Dane particle core after a DNA polymerase reaction with $\alpha$-($^{32}$P) dNTP, was identified as HBV DNA by liquid scintillation counter and agarose gel electrophoresis-G.M. counting. To produce Hepatitis B surface antigen for use as a vaccine against Hepatitis B virus infection, yeast strains harboring recombinant plasmid with Apase promoter was used. Recombinant plasmid was construced from pHBV 130 and pAN 82, transformed into E coli, and then transferred into yeast strains. HBsAg was produced by derepression in Burkholder minimal medium with controlled inorganic phosphate concentration. The kinetics of HBsAg production was also investigated. Total HBsAg activity increased rapidly between 3 and 6 hours after transfer to phosphate-free medium and reached a maximum at around 9th hour. The transfer into phosphate-free medium after 6 hours in high phosphate cell growth medium gave maximum activity.

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Time Synchronization between IoT Devices in a Private Network using Block-Chain (블록체인을 이용한 사설망에서의 IoT 기기 간 시간 동기화)

  • Ji, Soyeong;Kim, Seungeun;Yun, Eunju;Seo, Dae-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.5
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    • pp.161-169
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    • 2018
  • This study presents a time synchronization system in decentralized structure by using the blockchain, a core technology of Bitcoin introduced by Satoshi Nakamoto in 2008. In this study, Getting away from existing time synchronization system in centralized structure, A blockchain network has completely decentralized structure using public blockchain. In decentralized structure, Only certain peers among the peers that participate in a blockchain network access the NTP server. Therefore, others can synchronize time without having to go to public network. Furthermore if appropriate time synchronization cycles are established for each peer, time synchronization can be maintained even when connection to public network is completely lost. A time synchronization system in this study has advantages of p2p system and can be also guaranteed reliability and stability because it used digital signature, merkle tree, consensus algorithm which are core characteristics of block chains.

Fundamental Study for RAPD-PR Analysis in the Silkworm, Bombyx mori (누에 RAPD-PCR 분석을 위한 기초연구)

  • 황재삼;이진성
    • Journal of Sericultural and Entomological Science
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    • v.38 no.1
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    • pp.7-12
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    • 1996
  • Reproducible the random amplified polymorphic DNAs(RAPDs) patterns were obtained in the two silkworm strains(J111, Galwon) by adjusting concentration optimized of Taq DNA polymerase(one unit), dNTP(200$\mu$M), MgCl2(1.5mM) and template DNA(30ng). In addition, anealing temperature ranging 35$^{\circ}C$ to 42$^{\circ}C$ by the adjusted condition was investigated and fixed at 35$^{\circ}C$ in this study. Variation among individuals and between male and female of Jam 113 strain was not authorized. DNA polymorhpisms among silkworms were authorized by five RAPD markers using OPM04 random primer. Using the primer showing polymorhpims between parents(J111, Galwon) in thirty three individuals, RAPD-PCR for F2 analysis was performed and segregated 3 : 1 in the F2 population. Consequently, RAPDs detected in the parents were obtained as genetic markers, which can be used for construction of genetic map for this industrially particular insect, silkworm Bombyx mori

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A Study on the Development of a Cryogenic Air Separation Unit to Produce High Purity Nitrogen (고순도 질소생산용 초저온 공기분리장치 개발 연구)

  • 용평순;문흥만;이성철
    • Progress in Superconductivity and Cryogenics
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    • v.3 no.1
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    • pp.69-73
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    • 2001
  • For developing the cryogenic air separation unit, it requires some technology such as basic process design. equipment design and manufacturing based on the cryogenic physical properties and separation theory. In this study, we developed a process and equipment for producing high purity nitrogen which has the production capacity of 1600N㎥/h under 1 ppm $O_2$ and $H_2O$. Also we found that the number of theoretical plate(NTP) of distillation column was 44 and maximum nitrogen recovery ration of this process was 42% from the process simulation. The performance test was also carried out for the nitrogen recovery ratio and equipment efficiency. The results showed that the optimum nitrogen recovery was 41% and the maximum equipment efficiency was attained.

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An Analysis of Time Difference from Network Delay over UDP Network (UDP 환경에서 송수신 지연에 의한 시각오차 측정 및 분석)

  • 민충식;유동희;김영호
    • Proceedings of the Korean Information Science Society Conference
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    • pp.511-513
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    • 2000
  • 종단간 전송 지연은 시각 동기, 네트워크 성능 측정 등에서 매우 중요한 요소이다. 그러나 IP에 기반하고 있는 Internet은 여러 통신망 상의 지연 요소를 정확히 전달할 수 있는 구조가 없기 때문에 종단간 전송에 있어 전송 지연을 정확하게 알 수 없다. 특히 UDP 네트워크의 경우 전송할 때와 수신할 때 경로가 같지 않기 때문에 일반적으로 일주 지연 시간을 이용하지만 각 편도 전송 지연 시간 차이는 시스템의 다른 요소에 대해서 오류 요소로 작용할 수 있다. 본 논문에서는 일주 지연 시간을 전송시 지연 시간과 수신시 지연 시간으로 따로 측정 분석하였다. 측정 결과 편도 전송 지연 시간 차이 값은 수십 밀리초 범위를 가지며 이는 NTP 등에서 시각을 동기화 할 때 통상적인 정확도, 수 밀리초를 훨씬 넘어선다. 이것은 편도 지연 시간 차이값이 시각 동기, 네트워크 성능 평가 등에서 중요한 오류값으로 작용한다는 것을 의미한다. 분석 결과를 실험 데이터에 적용할 경우 실제 편도 지연 시간에 근사한 값을 구할 수 있고 좀더 정확한 시각 동기, 네트워크 성능 평가가 가능하게 된다.

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Advances in the Development and Validation of Test Methods in the United States

  • Casey, Warren M.
    • Toxicological Research
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    • v.32 no.1
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    • pp.9-14
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    • 2016
  • The National Toxicology Program Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM) provides validation support for US Federal agencies and the US Tox21 interagency consortium, an interagency collaboration that is using high throughput screening (HTS) and other advanced approaches to better understand and predict chemical hazards to humans and the environment. The use of HTS data from assays relevant to the estrogen receptor signaling data pathway is used as an example of how HTS data can be combined with computational modeling to meet the needs of US agencies. As brief summary of US efforts in the areas of biologics testing, acute toxicity, and skin sensitization will also be provided.

BLIND AUDIO WATERMARKING TECHNIQUE USING SPECIFIC FREQUENCY SIGNAL (특정된 주파수 신호를 이용한 오디오 워터마킹)

  • Piao, Cheng-Ri;Han, Seung-Soo;Choi, Jong-Uk
    • Proceedings of the KIEE Conference
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    • pp.2368-2372
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    • 2002
  • 멀티미디어의 저작권 보호를 위한 기술로서 워터마킹 기술은 현재 멀티미디어의 여러 분야에서 많이 연구되며 사용되고 있다. 이 기술은 컨텐츠가 질적으로 소비자에게 인식되지 않으며, 그리고 컨텐츠자체에 다양한 정보를 은닉하기 때문에 컨텐츠에 항상 포함되어 있다는 장점이 있다. 현재 MP3등과 같은 압축기술이 발달되어 있기 때문에 네트웍에 의한 데이터 전송성능이 향상되었고, 그러므로 디지털 데이터들이 유통이 활성화되었다. 이것으로 인하여 불법적으로 복제된 다양한 컨텐츠의 유통이 생산자의 이익을 해치고 있다. 디지털 오디오 컨텐츠의 소유권을 위하여, 본 논문에서는 압축에 대한 견고성을 제고하기 위하여 청각시스템의 마스킹 효과를 이용하여 시간영역에서 오디오신호에 특정된 주파수를 가진 워터마크 정보를 삽입하였다. 이 특정된 주파수는 반드시 압축에 살아남는 주파수 대역이어야 하며, 음질을 동시에 고려하여야 한다. 그리고 추출할 때는 FFT변환을 하여 주파수 대역에서 추출한다. 저작권 정보를 쉽게 확인하기 위하여 2진 송상을 워터마크 정보로 삽입하였다.

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