Abstract-The berthing of large ships in inclement weather with frequently poor visibility presents a challenge. To assist with this application, it may be beneficial to utilise standard radar imaging. Whilst this may be achieved using a mechanically-scanned system, reliability, cost and weight issues, coupled with the need to primarily image only a 120 • sector on the port and starboard of the ship, make phased array radar an attractive possibility. Multiple-Input MultipleOutput (MIMO) radar, with its ability to enhance the resolution available from a given number of elements, is particularly suited to a short-range application such as this in which there is sufficient time to switch between antenna elements as an alternative to more complex implementations. This paper describes a system of this nature from its basic architecture to development and validation, including some artefacts of the particular topology employed.
r = 2r! c difference between the two inputs. By analyzing the spectrum of the mixer output, the range information can be obtained as the output signal frequency is proportional to the target range. (Fig. I(a))Abstract-This paper introduces a new method for estimating location of radio frequency identification (RFID) tags for application in indoor environments. The proposed positioning scheme employs a time-difference of arrival (TDOA) range estimation algorithm. The time-difference measurement is performed by taking advantage of the de-ramp properties of a linear frequency modulation (LFM) chirp. The paper provides details of the mechanism of this LFM-TDOA scheme from the system point of view. Compared to other popular radio technologies in the indoor positioning field, this new scheme is easy to design and requires only moderate computation ability. According to the experiment results summarized in the paper, the LFM-TDOA system shows good range estimation accuracy and thus has the potential to be used in accurate indoor location application.
Stay green (SG) in wheat, a beneficial trait for increasing yield and stress resistance, needs to be supported by analysis of the underlying genetic basis. Spectral reflectance indices (SIs) provide non-destructive tools to evaluate crop temporal senescence. However, few SI-based SG quantification pipelines for analyzing diverse wheat panels in the field are available. Here, we first applied SIs to monitor the senescence dynamics of 565 diverse wheat accessions from anthesis to maturation stages during two field seasons. Based on over 12,000 SIs data set, four SIs (NDVI, GNDVI, NDRE and OSAVI) were selected to develop relative stay green scores (RSGS) and the senescence of wheat populations occurs mainly at four developmental stages stage 1 (S1) to S4, accounting for the final SG indicators. A RSGS-based genome-wide association study identified 47 high-confidence quantitative trait loci (QTL) harboring 3,079 SNPs significantly associated with RSGS and 1,085 corresponding candidate genes in the two seasons; 15QTL overlapped or were adjacent to known SG-related QTL or genes and the remaining QTL were novel. Finally, we selected three superior candidate genes (TraesCS6B03G0356400, TraesCS2B03G1299500, and TraesCS2A03G1081100) as examples by transcriptomes, gene annotation, and gene-based association analysis for further analysis and found that utilization of superior SG-related variation in China gradually increased following the Green Revolution. The study provides a useful reference for further SG-related gene discovery of favorable variations in diverse wheat panels.
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