مطالب مرتبط با کلیدواژه

Transportation


۱.

The Parameters Affecting the Mathematical Programming Model of the Appropriate Transportation System(مقاله علمی وزارت علوم)

کلیدواژه‌ها: Transportation traffic Optimal Route Traffic Reduction

حوزه های تخصصی:
تعداد بازدید : ۱۹۲ تعداد دانلود : ۱۳۵
Due to the importance of public transportation, which has become today an important urban problem with special conditions, this study was conducted aimed at determining the parameters affecting the mathematical programming model of the appropriate transportation system. The study was performed by modeling method, and the problem was solved in three different sizes (small, medium and large) to show the efficiency of the model and the proposed solution methods. Some common test problems in the literature were selected and the required characteristics of the problem under study were defined for them as needed, since there are no sample test problems in the literature to examine the performance of the developed algorithms. The results indicated that some of the most important parameters affecting the designed mathematical model were movement risks, fatigue and drowsiness while driving, demands at the source node, demands at the destination node, number of vehicles across the network, the time interval between requests, and the time interval between two consecutive requests. The mentioned parameters were so effective that little changes in parameters such as demands at the source node, demands at the destination node, and the number of vehicles across the network significantly increased time and decreased profitability. the company has a significant effect on the debt cost rate and capital cost rate and does not have a significant effect on stock prices. Finally, the share price shows little sensitivity to the company's financial structure.
۲.

اثرات متقابل حمل و نقل، رشد اقتصادی و انتشار دی اکسیدکربن در ایران(مقاله علمی وزارت علوم)

کلیدواژه‌ها: Transportation economic growth Environmental pollution Iran

حوزه های تخصصی:
تعداد بازدید : ۲۳۱ تعداد دانلود : ۱۴۴
The purpose of this paper is to investigate the interrelationships between transportation (rail and air), economic growth and carbon dioxide emissions in Iran during the period 1362-1397 using time series data and the system of simultaneous equation approach. The findings show a positive correlation between transportation (rail and air) and economic growth, as well as between transportation (rail and air) and carbon dioxide emissions. Another finding of this study is that economic growth has a significant effect on increasing carbon dioxide emissions, but increasing carbon dioxide emissions has no effect on economic growth. Based on the results, the creation and development of infrastructure related to the type of transportation in order to improve the country's economic growth is proposed.