scholarly journals Estimating Road Design Hourly Volume via Inflection Point Identification

2013 ◽  
Vol 33 (6) ◽  
pp. 2427 ◽  
Author(s):  
Seongchae Ahn
Author(s):  
Hoi Le Quoc ◽  
Hoi Chu Minh

Financial development could exert various effects on income distribution of a country. By employing Generalized Method of Moment, this paper aims at examining the impacts of credit market depth, one of most used financial development barometers, on income inequality in Vietnam. The empirical findings show that expanding credit market in the country could lead to higher income inequality. We have not found evidence that supports the hypothesis of an inverted U-shaped relation ever introduced by Greenwood and Jovanovich, although this hypothesis may still hold in a sense that Vietnam has not reached to the inflection point to generate such a curve alike.


2020 ◽  
Vol 17 (6) ◽  
pp. 511-522 ◽  
Author(s):  
Alicia Graciela Cid ◽  
María Verónica Ramírez-Rigo ◽  
María Celeste Palena ◽  
Elio Emilio Gonzo ◽  
Alvaro Federico Jimenez-Kairuz ◽  
...  

Background: Mathematical modeling in modified drug release is an important tool that allows predicting the release rate of drugs in their surrounding environment and elucidates the transport mechanisms involved in the process. Objective: The aim of this work was to develop a mathematical model that allows evaluating the release profile of drugs from polymeric carriers in which the swelling phenomenon is present. Methods: Swellable matrices based on ionic complexes of alginic acid or carboxymethylcellulose with ciprofloxacin were prepared and the effect of adding the polymer sodium salt on the swelling process and the drug release was evaluated. Experimental data from the ciprofloxacin release profiles were mathematically adjusted, considering the mechanisms involved in each stage of the release process. Results: A proposed model, named “Dual Release” model, was able to properly fit the experimental data of matrices presenting the swelling phenomenon, characterized by an inflection point in their release profile. This entails applying the extended model of Korsmeyer-Peppas to estimate the percentage of drug released from the first experimental point up to the inflection point and then a model called Lumped until the final time, allowing to adequately represent the complete range of the drug release profile. Different parameters of pharmaceutical relevance were calculated using the proposed model to compare the profiles of the studied matrices. Conclusion: The “Dual Release” model proposed in this article can be used to predict the behavior of complex systems in which different mechanisms are involved in the release process.


Author(s):  
Thierry Brenac

This paper deals with safety at horizontal curves on two-lane roads outside urban areas and the way the road design standards of different European countries account for this safety aspect. After a review of some research results, the main aspects of curve geometry and the curve's place in the horizontal alignment are analyzed. The main conclusions are that the traditional design speed approach is insufficient and that formal complementary rules in road design standards, especially to improve compatibility between successive elements of the alignment, must be introduced. If such complementary rules already exist in some national standards, they are neither frequent nor homogeneous throughout the different countries, and it seems that they are not based on sufficiently developed knowledge.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2116
Author(s):  
Yue Xiao ◽  
Limin Tang ◽  
Jiawei Xie

There are great uncertainties in road design parameters, and the traditional point numerical calculation results cannot reflect the complexity of the actual project well. Additionally, the calculation method of road design theory based on interval analysis is more difficult in the use of uncertain design parameters. In order to simplify the calculation process of the interval parameters in the road design theory, the asphalt pavement design is taken as the analysis object, and the permanent deformation of the asphalt mixture is simplified by combining the interval analysis theory. Considering the uncertainty of the design parameters, the data with boundaries but uncertain size are expressed in intervals, and then the interval calculation formula for the permanent deformation of the asphalt mixture is derived, and the interval results are obtained. In order to avoid the dependence of interval calculation on the computer code, according to the interval calculation rule, the interval calculation method with the upper and lower end point values as point operations is proposed. In order to overcome the contradiction between interval expansion results and engineering applications, by splitting the multi-interval variable formulas, the interval variable weights are reasonably given, and the synthesis of each single interval result realizes a simplified calculation based on interval variable weight assignment. The analysis results show that the interval calculation method based on the point operation rule is accurate and reliable, and the simplified method based on the interval variable weight assignment is effective and feasible. The simplified interval calculation method proposed in this paper provides a reference for the interval application of road design theory.


Author(s):  
Tom P. C. Schlösser ◽  
René M. Castelein ◽  
Pierre Grobost ◽  
Suken A. Shah ◽  
Kariman Abelin-Genevois

Abstract Purpose The complex three-dimensional spinal deformity in AIS consists of rotated, lordotic apical areas and neutral junctional zones that modify the spine’s sagittal profile. Recently, three specific patterns of thoracic sagittal ‘malalignment’ were described for severe AIS. The aim of this study is to define whether specific patterns of pathological sagittal alignment are already present in mild AIS. Methods Lateral spinal radiographs of 192 mild (10°–20°) and 253 severe (> 45°) AIS patients and 156 controls were derived from an international consortium. Kyphosis characteristics (T4–T12 thoracic kyphosis, T10–L2 angle, C7 slope, location of the apex of kyphosis and of the inflection point) and sagittal curve types according to Abelin-Genevois were systematically compared between the three cohorts. Results Even in mild thoracic AIS, already 49% of the curves presented sagittal malalignment, mostly thoracic hypokyphosis, whereas only 13% of the (thoraco) lumbar curves and 6% of the nonscoliosis adolescents were hypokyphotic. In severe AIS, 63% had a sagittal malalignment. Hypokyphosis + thoracolumbar kyphosis occurred more frequently in high-PI and primary lumbar curves, whereas cervicothoracic kyphosis occurred more in double thoracic curves. Conclusions Pathological sagittal patterns are often already present in curves 10°–20°, whereas those are rare in non-scoliotic adolescents. This suggests that sagittal ‘malalignment’ patterns are an integral part of the early pathogenesis of AIS.


Mathematics ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 969
Author(s):  
Lei Shen ◽  
Xi Zhang ◽  
Hongda Liu ◽  
Pinbo Yao

With the rise of a new generation of technology and industrial changes, the service-oriented manufacturing industry has become the direction of future development. With the background of new manufacturing, this paper constructs an economic development threshold model of employment density of consumer goods industry based on data from Shanghai and Tokyo from 2007 to 2016, and empirically analyzes the impact of the employment density of the consumer goods industry on urban economic development under different population densities. At the same time, by comparing the experience of Tokyo, the development status and prospects of Shanghai’s consumer goods industry are explored. The study found that the threshold of Tokyo’s consumer goods industry is 0.608. When population density is lower than this threshold, the consumer goods industry continues to promote the economic development of Tokyo; however, when the population density is higher than this threshold, the consumer goods industry begins to inhibit the economic development of Tokyo. The Shanghai consumer goods industry threshold is 0.329. Under the threshold, most of the consumer goods industry contributions to the economy are negative, but above the threshold, they begin to show a positive trend. The inflection point of the effect curve of Tokyo’s consumer goods industry on economic development has appeared, but the inflection point of Shanghai’s consumer goods industry has not yet appeared. Compared with Tokyo, the economic vitality of Shanghai’s consumer goods industry has not yet been fully released. With the continued increase of population density in Shanghai, the growth potential of the consumer goods industry is huge, and it is expected to reshape the flourishing age of Shanghai’s light industry brand.


2021 ◽  
Vol 13 (4) ◽  
pp. 2039
Author(s):  
Juan F. Dols ◽  
Jaime Molina ◽  
F. Javier Camacho-Torregrosa ◽  
David Llopis-Castelló ◽  
Alfredo García

The analysis of road safety is critical in road design. Complying to guidelines is not enough to ensure the highest safety levels, so many of them encourage designers to virtually recreate and test their roads, benefitting from the evolution of driving simulators in recent years. However, an accurate recreation of the road and its environment represents a real bottleneck in the process. A very important limitation lies in the diversity of input data, from different sources and requiring specific adaptations for every single simulator. This paper aims at showing a framework for recreating faster virtual scenarios by using an Industry Foundation Classes (IFC)-based file. This methodology was compared to two other conventional methods for developing driving scenarios. The main outcome of this study has demonstrated that with a data exchange file in IFC format, virtual scenarios can be faster designed to carry out safety audits with driving simulators. As a result, the editing, programming, and processing times were substantially reduced using the proposed IFC exchange file format through a BIM (Building Information Modeling) model. This methodology facilitates cost-savings, execution, and optimization resources in road safety analysis.


2021 ◽  
Vol 13 (5) ◽  
pp. 2803
Author(s):  
Huaide Wen ◽  
Jun Dai

This paper extends the “sources of growth” explanation for the Environmental Kuznets Curve (EKC) proposed by Copeland and Taylor in a concise theoretical framework, that is, when the sources of growth are transformed from physical capital and labor to human capital and knowledge, the environmental pollution could at first rise and then fall with a sustainable growth in per capita income. Using the provincial panel data from 1995 to 2017 in the mainland of China, an empirical analysis is carried out by the System Generalized Method of Moment (sys-GMM). The results show that: first, the EKC hypothesis exists in China. The inflection point for SO2 emissions has been passed in all of the provincial regions, and for CO2 and comprehensive environmental pollution losses have not been passed in some regions, but the inflection point from the national average level in China has been passed; second, the main production factors of the traditional economy, physical capital and labor, are positively correlated with environmental pollution, while human capital and green technological progress, the main production factors of the knowledge economy, are negatively related to environmental pollution; third, human capital and green technological progress have become important factors to promote economic growth, and human capital, in particular, has become the primary factor, which indicates that China is in the process of transforming traditional economy into a knowledge economy. The stage of China’s economic development and the trend of environmental pollution is consistent with the extended “sources of growth” explanation for the EKC, which proved the theoretical hypothesis. This has an important practical significance for China’s current economic reform and important theoretical value for the economic transformation and sustainable development of developing countries. The paper finally puts forward corresponding policy recommendations.


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