40,962 research outputs found
Kolmogorov-Smirnov method for the determination of signal time-shifts
A new method for the determination of electric signal time-shifts is
introduced. As the Kolmogorov-Smirnov test, it is based on the comparison of
the cumulative distribution functions of the reference signal with the test
signal. This method is very fast and thus well suited for on-line applications.
It is robust to noise and its performances in terms of precision are excellent
for time-shifts ranging from a fraction to several sample durations.
PACS. 29.40.Gx (Tracking and position-sensitive detectors), 29.30.Kv (X- and
-ray spectroscopy), 07.50.Qx (Signal processing electronics)Comment: 8 pages, 7 figure
Secrecy outage probability of a NOMA scheme and impact imperfect channel state information in underlay cooperative cognitive networks
Security performance and the impact of imperfect channel state information (CSI) in underlay cooperative cognitive networks (UCCN) is investigated in this paper. In the proposed scheme, relay R uses non-orthogonal multiple access (NOMA) technology to transfer messages e1, e2 from the source node S to User 1 (U1) and User 2 (U2), respectively. An eavesdropper (E) is also proposed to wiretap the messages of U1 and U2. The transmission’s security performance in the proposed system was analyzed and performed over Rayleigh fading channels. Through numerical analysis, the results showed that the proposed system’s secrecy performance became more efficient when the eavesdropper node E was farther away from the source node S and the intermediate cooperative relay R. The secrecy performance of U1 was also compared to the secrecy performance of U2. Finally, the simulation results matched the Monte Carlo simulations well
Fast analytical methods for the correction of signal random time-shifts and application to segmented HPGe detectors
Detection systems rely more and more on on-line or off-line comparison of
detected signals with basis signals in order to determine the characteristics
of the impinging particles. Unfortunately, these comparisons are very sensitive
to the random time shifts that may alter the signal delivered by the detectors.
We present two fast algebraic methods to determine the value of the time shift
and to enhance the reliability of the comparison to the basis signals.Comment: 13 pages, 8 figure
Identifying QTLs Associated and Marker-Assisted Selection for Salinity Tolerance at the Seedling, Vegetative and Reproductive Stages in Rice (Oryza Sativa L.)
Salinity affects rice growth in all growth stages, with the seedling and reproductive stages being the most sensitive. Genetically improving salt tolerance of rice is an important objective of rice breeding programs. Hence, mapping quantitative trait loci (QTL) will be useful for marker-assisted selection in rice breeding programs. An advanced backcross population (BC2F2) was developed with the parents included OM5629 as a donor of salt tolerance and OM7347 as a recurrent parent with good quality traits and drought tolerance. Molecular markers associated with both qualitative and quantitative trait loci (QTL) salt tolerance were identified by using 416 polymorphic SSR markers. QTLs, associated with stress tolerance at EC = 15 dS/m at seedling stage, detected from the BC2F2 population of OM7347/OM5629, were located on chromosomes 1 and 3. Three QTLs were identified at the intervals of RM3252-S1-1 - RM10694, RM3740-RM5336 and RM11125-RM9 with genetic distance of 4.4, 4.5 and 18 cM on chromosome 1, respectively. Two QTLs at the intervals of RM3867-RM6959 and RM6876-RM4425 with genetic distance of 4.5 and 18.0 cM on chromosome 3, respectively. One QTL on chromosome 5 was detected at the interval of RM874 - RM10359, it was associated with salt stress tolerance under EC = 8dS/m at vegetative stage. Three QTLs at the regions of RM1324-RM2412, RM1185-RM24, and RM1282-RM2560 on chromosome 1, and one QTL of RM453-RM511 on chromosome 12, were related to salt tolerance under EC = 8dS/m at reproductive stage. Two tightly linked markers as RM3252-S1-1 and RM3867, were exhibited their effectiveness in identification of salt tolerance genotypes in BC3F6 population of OMCS2000/ Pokkali. The identification of new QTLs associated with salt tolerance will provide important information for the functional analysis of rice salinity stress
Size dependent line broadening in the emission spectra of single GaAs quantum dots: Impact of surface charges on spectral diffusion
Making use of droplet epitaxy, we systematically controlled the height of
self-assembled GaAs quantum dots by more than one order of magnitude. The
photoluminescence spectra of single quantum dots revealed the strong dependence
of the spectral linewidth on the dot height. Tall dots with a height of ~30 nm
showed broad spectral peaks with an average width as large as ~5 meV, but
shallow dots with a height of ~2 nm showed resolution-limited spectral lines
(<120 micro eV). The measured height dependence of the linewidths is in good
agreement with Stark coefficients calculated for the experimental shape
variation. We attribute the microscopic source of fluctuating electric fields
to the random motion of surface charges at the vacuum-semiconductor interface.
Our results offer guidelines for creating frequency-locked photon sources,
which will serve as key devices for long-distance quantum key distribution.Comment: 6 pages, 6 figures; updated figs and their description
Policy, innovation and cost reduction in UK offshore wind
Offshore wind in the UK has been a remarkable green growth success story. The price of offshore wind is less than a third of what it was a decade ago (Figure 1). In UK conditions, it is now cost competitive with new fossil fuel generation1. Indeed, if electricity prices return to pre-Covid levels, the Government would no longer be subsidising new offshore wind; HM Treasury will be earning revenue instead2. In parallel, the industry has grown and matured to a point where oil and gas companies are clamouring to enter the market and pension funds are comfortable in investing billions of pounds into construction
Phenotypic Screening of Drought-Tolerant Lines for Brown Planthopper, Blast and Phytic Acid Content Assay of Rice (Oryza sativa L.)
Advanced drought tolerant lines were analysed for blast disease, brown planthopper (BPH), and phytic acid content. Thirsty lines of BC2F4 derived from OMCS2000/ IR75499-73-1 were used to screen for BPH and blast resistance. Three good resistant lines were screened against blast (45, 54, and 310) under greenhouse condition. As eight lines were identified to be resistant to BPH. The results further reveal that BC2F4-45 was the best line resistant to both BPH and blast disease. These lines will be useful in reducing grain phytic acid and improving the nutritional value of rice grain. Based on an assay for high phosphate germination stage of rice, the lowest content was found in the I5 variety (line 45). Hence, this line provides the urgent objective for breeders in cultivars of these crops to genetically enhance a healthy and functional diet. These characters will then need to be incorporated into high yield under drought stress with others such as disease and insect resistance
Large magnetoresistance using hybrid spin filter devices
A magnetic "spin filter" tunnel barrier, sandwiched between a non-magnetic
metal and a magnetic metal, is used to create a new magnetoresistive tunnel
device, somewhat analogous to an optical polarizer-analyzer configuration. The
resistance of these trilayer structures depends on the relative magnetization
orientation of the spin filter and the ferromagnetic electrode. The spin
filtering in this configuration yields a previously unobserved
magnetoresistance effect, exceeding 100%.Comment: 3.5 pages, 3 figures, submitted to Appl. Phys. Let
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