An Integrated Approach for Table Detection and Structure Recognition

Detecting and identifying the table structure is an important issue in document digitization. Although there have been many great strides based on current deep learning techniques, table structure identification is still a difficult and difficult problem, especially when solving the problem of digitizing text in practice. The paper proposes a solution to digitize table documents based on the Cascade R-CNN HRNet network to detect, classify tables and integrate image processing algorithms to improve table data identification results. The proposed algorithm proved effective on real data - the hydrometeorological station record book contains tables including simple and complex structures tables with over 98% accuracy.

Demonstration of polarisation calibration with the LBA on Selected AGNs

We present here the results from a full polarisation study, an important VLBI capability, of a selected set of bright Active Galactic Nuclei (AGNs), along with the steps required to fully calibrate the Australian Long Baseline Array. We compare strategies for high-precision polarisation measurements using two polarisation correction methods: (1) Linear model and (2) Ellipticity-Orientation model and two data-recording techniques: recording (1) nominally circular polarisation at all stations and (2) mixed polarisation, where all but one station record circular polarisation and the other recorded linear polarisation. The latter is corrected post-correlation. We explored these possible solution to discover which will best accommodate the heterogeneous nature of the Australian Long Baseline Array without impacting on the science results. The targets, all compact and of low polarisation fraction, allow us to compare multiple independent solutions for polarisation characteristics. The results show that the agreement between the two polarisation correction models is excellent. However, the values from Mopra with nominally circular polarisation are larger than would be acceptable. However, we also demonstrate that recording mixed polarisation modes and correcting post-correlation provide a high quality polarisation product. We report on the detailed tests of these strategies and assess that the array is ready for full polarisation operation.

Comparative study on wave hindcasting using wind downscaling data at Bojong Salawe Beach

The wind data have a crucial role in shore construction engineering, but the availability data is commonly rare. Some research and recording station provide wind data with four times data record in a day. This research calculated the wave as resulted of the downscaled wind data from four times a day to twenty four times a day recording. The research done by comparing several data obtained from satellite record and land-station record. The results show similarity in wind velocity and dominance direction but have significant differences of wave height and the direction of wave from difference record locations.

Estimation of Uncertainty in Temperature Observations Made at Meteorological Stations Using a Probabilistic Spatiotemporal Approach

A probabilistic spatiotemporal approach based on a spatial regression test (SRT-PS) is proposed for the quality control of climate data. It provides a quantitative probability that represents the uncertainty in each temperature observation. The assumption of SRT-PS is that there might be large uncertainty in the station record if there is a large residual difference between the record estimated in the spatial regression test and the true station record. The result of SRT-PS is expressed as a confidence probability ranging from 0 to 1, where a value closer to 1 indicates less uncertainty. The potential of SRT-PS to estimate quantitatively the uncertainty in temperature observations was demonstrated using an annual temperature dataset for China for the period 1971–2000 with seeded errors. SRT-PS was also applied to assess a real dataset, and was compared with two traditional quality control approaches: biweight mean and biweight standard deviation and SRT. The study provides a new approach to assess quantitatively the uncertainty in temperature observations at meteorological stations.

Two Decades of Environmental Isotope Records in Croatia: Reconstruction of the Past and Prediction of Future Levels

A two-decade-long record of environmental isotopes (2H, 3H, 14C, 18O) in Croatia is presented and the data are statistically analyzed. The atmospheric 14C activity for the period before the actual measurements started is reconstructed by measuring tree rings from the clean-air sites, and the past tritium activity in precipitation is estimated by the correlation of our data with the Vienna station record. The long-term 3H record helped to determine a locally contaminated sampling site, and new clean sites are put into operation. The 14C data were fitted by an analytical function and the prediction of future levels is given assuming that the rate of the 14C releases remains constant. From the long-term stable isotope data record, the local meteoric water line and the temperature gradient of δ18O in precipitation are determined.