Evaluation of cloud seeding project in Yazd Province of Iran using historical regression method(case study:Yazd 1 cloud seeding project,1999)

In this research, the result of the cloud seeding over Yazd province during three months of February, March and April in 1999 has been evaluated using the historical regression method. Hereupon, the rain-gages in Yazd province as the target stations and the rain-gages of the neighboring provinces as the control stations have been selected. The rainfall averages for the three aforementioned months through 25 years (1973-1997) in all control and target stations have been calculated. In the next step, the correlations between the rainfalls of control and target stations have been estimated about 75%, which indicates a good consistency in order to use the historical regression. Then, through the obtained liner correlation equation between the control and target stations the precipitation amount for February, March and April in 1999, over the target region (Yazd province) was estimated about 27.57 mm, whiles the observed amount was 34.23 mm. In fact the precipitation increasing around 19.5% over Yazd province confirmed the success of this cloud seeding project.

The Practical Historical Approach:A Review of the Principles and Methods of Fact-First History

This article defines and defends"the practical historical approach",a long-established approach to history which prizes the critical treatment of sources and,above all else,the presentation and assessment of accurate information about the past.This approach appreciates the value of historical fact in its own right,not just when it furnishes an opportunity to build theories or to prove points.The article does not aim to make a theoretical case for empiricist history,arguing instead that the old philosophy-driven debates about empiricism have little bearing on the practice of historical research and writing.It prefers to make a practical defence of certain critical methods and habits of thought which are now sometimes dismissed as old-fashioned.It draws on a series of historians'handbooks dating from 1889 to 1980,in which the methods and principles of the practical approach were worked out and refined,and it identifies the main principles and techniques of this approach,many of which derive from the German“scientific"historical tradition,and which furnish historians with a powerful apparatus for critically analyzing sources.The article also has a polemical angle,arguing that the practical historical approach could profitably be taught more consciously inuniversities.

Text extraction method for historical Tibetan document images based on block projections

Text extraction is an important initial step in digitizing the historical documents. In this paper, we present a text extraction method for historical Tibetan document images based on block projections. The task of text extraction is considered as text area detection and location problem. The images are divided equally into blocks and the blocks are filtered by the information of the categories of connected components and corner point density. By analyzing the filtered blocks' projections, the approximate text areas can be located, and the text regions are extracted. Experiments on the dataset of historical Tibetan documents demonstrate the effectiveness of the proposed method.