Bus dwell time contribute to much of the bus travel time and headway variations, meanwhile influence bus service reliability and restrict bus stop capacity directly. But in terms of how passenger passenger characteris...
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ISBN:
(纸本)9781479960798
Bus dwell time contribute to much of the bus travel time and headway variations, meanwhile influence bus service reliability and restrict bus stop capacity directly. But in terms of how passenger passenger characteristics affect bus dwell time under different bus stop types, many of researches found in the literature are not enough. Firstly numbers of passenger alighting/boarding, bus arrival and depart rate were collected via videos, including linear and non-linear bus stops, also dwell time distribution was test respectively. Secondly quantitative analysis of dwell time vs various variables have been done. Based on field data, multiple linear regression model were proposed and estimated. At last the dwell time equations were compared with equations found in the literature, meanwhile comparison between measured value and theoretical value has been done to test the accuracy of the regressionmodel. The results show dwell time follow Erlang-distribution, and in non-linear bus stop average boarding time is 1.5~3.2s higher than linear bus stop. Among all the regressionmodels, using the maximum of boarding and alighting passengers as independent variable show the most accuracy.
Dividend policy is one of the three-core content of financial management of modern companies, and it is not only related to the company's background, but also associated with the company's industry. China has ...
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ISBN:
(纸本)9781784660529
Dividend policy is one of the three-core content of financial management of modern companies, and it is not only related to the company's background, but also associated with the company's industry. China has a strict control on the petroleum and petrochemical industry, so there is serious state-owned monopoly capital in petroleum and petrochemical market, which makes the petroleum and petrochemical companies completely different characteristics from other industries. This paper selects the latest data of petroleum and petrochemical listed companies in the securities market of China, and then adopts empirical research methods to study what factors influence the dividend policy of listed companies using a multiple linear regression model, in order to put forward suggestions for the improvement of the dividend policy. The research we have done suggests that cash flow from operations per share, net assets per share, net assets growth rate and ownership concentration have an important influence on cash dividend per share for petroleum and petrochemical listed companies. The results of the paper indicate that there is serious speculation in China's securities market, and the majority shareholders expropriate minority shareholders and the petroleum and petrochemical listed companies are lack of growth.
Open-Loop Fiber Optic Gyroscopes (FOG) is widely used,which is easily affected by the temperature around *** temperature model has a very complicated nonlinear characteristic.A BP neural network model with advantage o...
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ISBN:
(纸本)9781479946983
Open-Loop Fiber Optic Gyroscopes (FOG) is widely used,which is easily affected by the temperature around *** temperature model has a very complicated nonlinear characteristic.A BP neural network model with advantage of approximating the nonlinear function was developed to simulate outputs of an open-loop FOG and then compensate the FOG's temperature error in full temperature range??–50??~ +70????.With experimental data,the networks with one-hidden-layer structure adopted the temperature and the temperature change rate as network inputs,and the outputs of FOG as network *** results showed that the number of hidden-layer neurons plays an important role in simulation performance,and the network with 11 hidden-layer neurons offered better precision and ***,the comparison of 4 different training algorithms demonstrated that the Levenberg-Marquardt algorithm resulted in a better convergence during training *** the chosen structure and training algorithm,the BP neural network model was used to compensate the temperature error of the *** was found that the compensated outputs of the FOG became more accurate and more *** addition,the neural network model further proved its superiority of precision and robustness by comparison with a multiple linear regression model and a quadratic curve fitting model.
In the field of wireless sensor networks, missing data has been an issue of widespread concern. In this paper, an improved algorithm based on different data types, is proposed. Missing data is estimated by a new algor...
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In the field of wireless sensor networks, missing data has been an issue of widespread concern. In this paper, an improved algorithm based on different data types, is proposed. Missing data is estimated by a new algorithm ,which is based on a variety of data types. Data, which is dynamic and transitional, is a correlative of missing data. And the multiple linear regression model is used to solve the problem of missing data whose type of value is different from the others. The proposed algorithm can not only ensures the normal data transmission, but also improves the traditional methods in dealing with the problem of the incompleteness of multiple data. Furthermore, the proposed algorithm avoids the limitations of the traditional methods for estimating real-time data.
In order to achieve effective control of thermal error compensation of computer numerical control (CNC) machine tools, the prediction accuracy and robustness of the compensation model is particularly important. In thi...
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In order to achieve effective control of thermal error compensation of computer numerical control (CNC) machine tools, the prediction accuracy and robustness of the compensation model is particularly important. In this paper, the temperature of sensitive points and thermal error of the spindle in Z direction are measured. Using a combination of fuzzy clustering analysis and gray correlation method to select temperature-sensitive points and then using multiplelinearregression of least squares and least absolute estimation methods, distributed lag model, and support vector regression machine to establish prediction models of the relationship between temperature of sensitive points and the thermal error. Also, the temperature values of sensitive points and the thermal error in the experimental conditions of different ambient temperatures and different spindle speeds are measured. By comparing the prediction accuracy of various prediction models under different experimental conditions verify the robustness of the models. Experimental results show that when the modeling data are less, the prediction accuracy of multiplelinearregression of least squares and least absolute estimation methods and distributed lag model is declined, and their robustness are poor, while support vector regressionmodel has good prediction accuracy and its robustness remains strong when changing the experimental conditions. However, when modeling data are rich, the prediction accuracy of various algorithms is improved, but the robustness of support vector regressionmodel is volatile. The robustness analysis of different models provides a useful reference for the thermal error compensation model, selection of CNC machine tools, and has good engineering applications.
Ulaanbaatar, the capital city of Mongolia, with a population of 1.1 million is located at an altitude of about 1350 m and in a valley. This study is the first to document the characteristics of the urban heat island (...
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Ulaanbaatar, the capital city of Mongolia, with a population of 1.1 million is located at an altitude of about 1350 m and in a valley. This study is the first to document the characteristics of the urban heat island (UHI) in Ulaanbaatar. Data from two meteorological stations, an urban site and a rural site, for the 31-year period 1980-2010 are used for UHI analysis. The average UHI intensity is 1.6A degrees C. The UHI intensity exhibits a large seasonal dependence, being strongest in winter (3.3A degrees C) and weakest in summer (0.3A degrees C). The average daily maximum UHI intensity is 4.3A degrees C. The strongest daily maximum UHI intensity occurs in winter with an average intensity of 6.4A degrees C, and the weakest one occurs in summer with an average intensity of 2.5A degrees C. The occurrence frequency of the daily maximum UHI intensity in the nighttime is 5.6 times that in the daytime. A multiplelinearregression analysis is undertaken to examine the relative importance of meteorological parameters (previous-day maximum UHI intensity, wind speed, cloudiness, and relative humidity) that affect the daily maximum UHI intensity. The half of the variance (49.8%) is explained by the multiple linear regression model. The previous-day maximum UHI intensity is the most important parameter and is positively correlated with the daily maximum UHI intensity. Cloudiness is the second most important parameter and is negatively correlated with the daily maximum UHI intensity. When the data are classified into daytime/nighttime and season, the relative importance of the meteorological parameters changes. The most important parameter in spring and summer is cloudiness, while in autumn and winter it is the previous-day maximum UHI intensity.
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