Operating speed models for curved segments of highways in plateau regions

To examine the influence of the harsh environment in plateau areas on the operating speed of vehicles,advanced speed prediction models for curved segments are established based on observed actual speed data.First,the speed characteristics at the starting,mid,and end points of a plane curve were observed on Lalin Highway and China National Highway 318 with Bushnell s handheld radar speedometer 10-1911CN.Second,the stepwise regression method was proposed to determine the significant parameters and propose the prediction models of the operating speed of cars and large vehicles for the two highways.Finally,reserved test group data were utilized to prove the validity and practicality of the proposed models.Compared with traditional methods,the established models can produce more accurate prediction results and deeply examine the nonlinear relationships between parameters and the predicted operating speed.This study provides a considerate direction and basis for the operating speed prediction model for other segments in plateau regions.

Theoretical and Empirical Analysis on Influence Factors of Modern Agricultural Equipment Level in the Processof Agricultural Sustainable Development

To promote modem agricultural equipment level is one characteristic of constructing and developing modem agriculture in China. This paper makes up stepwise linear regression analysis model of influence factors of modem agricultural equipment level, and chooses rural labor, per capita income of rural residents, rural investment, proportion of people at secondary education level and at higher level in per hundred rural labor force and arable land area as independent variables, and total power of machine as induced variable. The major results show that the relativity of modem ag- ricultural equipment level, rural investment and education level of peasants is remarkable, and they are the major influence factors of modem agricultural equipment level. Raising investment level of rural infrastructure construction as well as and research and devel- opment and promotion of advanced and applicable modem agricultural equipment, improving quality and education level of peasants can accelerate the development of China＇s modern agricultural equipment effectively in the process of agricultural sustainable development.

Investigation on flight load calibration of aircraft composite wing base on strain gauge measurement

A computational and test method for calibrating the flight loads carried by aircraft wings is proposed.The wing load is measured in real-time based on the resistance and fiber Bragg grating strain gauges.The linear stepwise regression method is used to construct the load equations.The mean impact value algorithm is employed to select suitable bridges.In the ground calibration experiment,the wing load calculation equations in both forward and reverse installation states are calibrated.The correctness of the load equations was verified through equation error and inspection error analysis.Finally,the actual flight load of the wing was obtained through flight tests.