Highlights A predicting model for the long-term epidemic trend of COVID-19 by using LSTM with rolling update mechanism is proposed. The 150-days ahead epidemic trend of COVID-19 in Russia, Peru and Iran are estimated by our proposed model. The results provide that the epidemic of Peru will end in early December. The number of daily cases in Russia and Iran is expected to fall below 2000 and 1000 by mid-November and early December. By introducing diffusion index, the effectiveness of preventive measures taken by the government are analyzed.

Unmanned aerial vehicle (UAV) low-altitude remote sensing technology has recently been adopted in China. However, mapping accuracy and production processes of true digital orthophoto maps (TDOMs) generated by UAV images require further improvement. In this study, ground control points were distributed and images were collected using a multi-rotor UAV and professional camera, at a flight height of 160 m above the ground and a designed ground sample distance (GSD) of 0.016 m. A structure from motion (SfM), revised digital surface model (DSM) and multi-view image texture compensation workflow were outlined to generate a high-precision TDOM. We then used randomly distributed checkpoints on the TDOM to verify its precision. The horizontal accuracy of the generated TDOM was 0.0365 m, the vertical accuracy was 0.0323 m, and the GSD was 0.0166 m. Tilt and shadowed areas of the TDOM were eliminated so that buildings maintained vertical viewing angles. This workflow produced a TDOM accuracy within 0.05 m, and provided an effective method for identifying rural homesteads, as well as land planning and design.

Urban construction land-use expansion is an important topic in the field of land-use change research. In the present study, the temporal and spatial changes of urban construction land use in the Chongqing urban area are analyzed, based on land-use maps from 1975, 1987, 1995, 2000, and 2010. Using gradient analysis, the study area was divided into nine buffer zones and eight quadrants. The study analyzed the compactness of the urban construction land in different buffer ranges and different directions, and further fitted the compactness degrees and different gradients. The results indicated that there was a rapid growth of urban construction land use in the Chongqing urban area in the period of 2000-2010, and the land use for urban construction sharply increased at an average annual rate of 5.69%. The expansion pattern showed a spatial mode of one center and multiple subcenters. Furthermore, although the key regions (the fastest-growing regions of urban construction land) of urban expansion showed higher compactness degree than the nonkey regions (the slowest-growing regions of urban construction land) of urban expansion, the compactness degrees were decreasing in the key regions but increasing in the nonkey regions. Specifically, the urban construction land had three highly compact zones in the buffer radius gradient-zones of radius 5, 25, and 40 km-and the compactness degrees gradually increased. When analyzed by the quadrant gradient of buffers, quadrants 45-90°( WNW), 90-135°(WSW), and 315-360°(NNE) were the key regions of urban expansion, and quadrants 225-270°(ESE) and 270-315°(ENE) were the nonkey regions. In addition, the change in compactness degree was highly correlated with changes in the buffer radius and quadrant azimuth. individual papers. This paper is part of the Journal of Urban Planning and Development, © ASCE, ISSN 0733-9488/05014009 (10)/$25.00. © ASCE 05014009-1 J. Urban Plann. Dev. J. Urban Plann. Dev., 2015, 141(1): 05014009 Downloaded from ascelibrary.org by Shanghai Jiaotong University on 10/09/15. Copyright ASCE. For personal use only; all rights reserved. © ASCE 05014009-2 J. Urban Plann. Dev. J. Urban Plann. Dev., 2015, 141(1): 05014009 Downloaded from ascelibrary.org by Shanghai Jiaotong University on 10/09/15. Copyright ASCE. For personal use only; all rights reserved. © ASCE 05014009-6 J. Urban Plann. Dev. J. Urban Plann. Dev., 2015, 141(1): 05014009 Downloaded from ascelibrary.org by Shanghai Jiaotong University on 10/09/15. Copyright ASCE. For personal use only; all rights reserved. © ASCE 05014009-10 J. Urban Plann. Dev. J. Urban Plann. Dev., 2015, 141(1): 05014009 Downloaded from ascelibrary.org by Shanghai Jiaotong University on 10/09/15.

In the study of spatiotemporal geographical phenomena, the space-time interpolation method is widely applied, and the demands for computing speed and accuracy are increasing. For nonprofessional modelers, utilizing the space-time interpolation method quickly is a challenge. To solve this problem, the classical ordinary kriging algorithm was selected and expanded to a spatiotemporal kriging algorithm. Using the OpenCL framework to integrate central processing unit (CPU) and graphic processing unit (GPU) computing resources, a parallel spatiotemporal kriging algorithm was implemented, and three experiments were conducted in this work to verify the results. The results indicated the following: (1) when the size of the prediction point dataset is consistent, the performance of the method is robust with the increasing size of the observation point dataset; (2) the acceleration effect of the parallel method increases with an increased number of predicted points. Compared with the original sequential program, the implementation of the improved parallel framework showed a 3.23 speedup, which obviously shortens the interpolation time; (3) when cross-validating the temperature data in the Beijing Tianjin Hebei region, the space-time acceleration model provides a better fit than traditional pure space interpolation.

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