جستجوی مقالات مرتبط با کلیدواژه « همبستگی پیرسون » در نشریات گروه « عمران »

Zagros forests are one of the important and strategic areas of the country. Forest inventories in areas like Zagros is expensive and time-consuming due to the difficult access and low density of trees. Laser scanning methods to prepare point clouds and produce maps provide valuable and significant information in forest management. With the release of the LiDAR short-range light detection sensor in 2020 by Apple, it became possible to use alternative scanning methods. In the present study, in order to check the accuracy of iPhone LiDAR in preparing point clouds of tree trunks, 37 Iranian oak trees were selected and specific longitudinal and transverse distances were marked on their trunks. The high accuracy of the point clouds for these distances resulted in a high correlation between the generated point clouds and the real distances. The RMSE% was obtained for longitudinal distances of 1.33 cm and for transverse distances of 2.2 cm respectively, which proves the high accuracy of the mentioned technology and its high capability in extracting quantitative components of tree trunks.

Transportation, and especially road transport, are among the main pillars of the country's development. Accordingly, the present study evaluates the status and situation of Iran's provinces in terms of road transport development indicators. The method of research is descriptive-analytic with a purposeful purpose. The statistical population of the research is 31 provinces of Iran in 2016. In this research, have been used based on available data, 24 indicators of road transport development in the form of four components of technical and infrastructural, passenger and goods transportation, safety, traffic and intelligent transportation. The Shannon entropy method was used to assign weights to each of the indices, and then the Vikor model was used to rank the provinces and evaluate their status and situation. The results indicate that the provinces of Tehran, Alborz, Qazvin and Hamadan are ranked first in the ranking and the provinces of Kerman, South Khorasan and Sistan and Baluchistan are in the last places of road development indicators. The results of Pearson correlation test indicate that there is a positive relationship between the population with the provinces having and the negative relationship between the area and the distance from the political center of the country (Tehran) with the provinces having the indicators of road transport development.