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Author(s):  
Bondita Robidas ◽  
Subrata Borgohain Gogoi

AbstractThis paper attempts to identify a crude oil (CO) from eight different CO samples with a wide range of oAPI gravity from 13 to 43 belonging to Upper Assam Basin, India, to formulate the identified CO for pipeline transportation. Studies were conducted to understand the physical, rheological, and viscoelastic properties of the CO samples where physical properties included pour point (PP) and oAPI gravity, the rheological properties included viscosity (η), kinematic viscosity (K.V.), viscosity gravity constant (VGC), shear stress (τ) and shear strain (γʹ) and the viscoelastic properties were elastic modulus (G)' and viscous modulus (G''). This research aims at achieving PP < 9 °C for CO for the ease of flow through pipeline even during the extreme winter season in Assam when the ambient temperature drops below 10o C. SKO in 0%, 5%, 10%, and 15% was added with all CO samples to determine the physical, rheological and viscoelastic properties at 30 °C, since PP of most of the CO samples was near 30 °C. However, the important properties of SKO, i.e. smoke point, flash point and boiling point, were not addressed here as SKO was used for improving flowability through pipeline. Correlation coefficients (CC) were determined using CORREL function in Microsoft Excel to investigate the relationship between oAPI gravity and the other properties for all the CO samples to identify the best fit CO. CO3 and CO8 were identified from the relationships as the most desired CO samples and CO3 was obtained as the best fit CO for the pipeline transportation.


2020 ◽  
Vol 251 ◽  
pp. 108797
Author(s):  
Fraser Shilling ◽  
Wendy Collinson ◽  
Michal Bil ◽  
Diemer Vercayie ◽  
Florian Heigl ◽  
...  

Aerospace ◽  
2020 ◽  
Vol 7 (8) ◽  
pp. 104
Author(s):  
Junzi Sun ◽  
Jacco M. Hoekstra ◽  
Joost Ellerbroek

Air traffic simulations serve as common practice to evaluate different concepts and methods for air transportation studies. The aircraft performance model is a key element that supports these simulation-based studies. It is also an important component for simulation-independent studies, such as air traffic optimization and prediction studies. Commonly, contemporary studies have to rely on proprietary aircraft performance models that restrict the redistribution of the data and code. To promote openness and research comparability, an alternative open performance model would be beneficial for the air transportation research community. In this paper, we introduce an open aircraft performance model (OpenAP). It is an open-source model that is based on a number of our previous studies, which were focused on different components of the aircraft performance. The unique characteristic of OpenAP is that it was built upon open aircraft surveillance data and open literature models. The model is composed of four main components, including aircraft and engine properties, kinematic performances, dynamic performances, and utility libraries. Alongside the performance model, we are publishing an open-source toolkit to facilitate the use of this model. The main objective of this paper is to describe each main component, their connections, and how they can be used for simulation and research in practice. Finally, we analyzed the performance of OpenAP by comparing it with an existing performance model and sample flight data.


2019 ◽  
Vol 11 (24) ◽  
pp. 7161 ◽  
Author(s):  
Patricia Lejoux ◽  
Aurore Flipo ◽  
Nathalie Ortar ◽  
Nicolas Ovtracht ◽  
Stéphanie Souche-Lecorvec ◽  
...  

Sustainable mobility has been one of the central paradigms of research in the field of transport and mobility for several decades. However, the implications of adopting the concept of “sustainable mobility” for the conduct of interdisciplinary research has been little discussed within the relevant research community. Research in the field of transport and mobility has nevertheless been the setting for major debates in recent years on the question of interdisciplinarity, or even transdisciplinarity, with the emergence of mobility studies as opposed to transportation studies. The objective of this paper is to show, empirically, how researchers who are specialised in mobility and transport issues, but who belong to different disciplines (anthropology, computer science, economics, geomatics, sociology and urban planning) have sought to build an interdisciplinary research project—which is currently ongoing—around the links between the development of coworking, which is a new way of organising work, mobility and sustainability. This paper sets out to highlight cross-fertilisation between disciplines, the issues raised, and the difficulties encountered. As such, it provides an account that is as faithful as possible to our experience of conducting interdisciplinary research in the area of sustainable mobility.


2019 ◽  
pp. 0739456X1985642 ◽  
Author(s):  
Petter Næss

This commentary presents a critique of a particular, strictly quantitative way of reviewing research findings within the field of land use and transportation studies, so-called meta-analyses. Beyond criticism raised earlier, the article draws attention to serious bias resulting when meta-analysis include studies encumbered with model specification error due to poor understanding of causal mechanisms. The article also discusses underestimated limitations due to neglect of differences between geographical contexts and inconsistent measurement of variables across studies. An example of an alternative approach is offered at the end of the article.


2019 ◽  
Vol 14 (6) ◽  
pp. 64
Author(s):  
Davit Gondauri ◽  
Manana Moistsrapishvili

The given paper emphasizes on the importance of the Railway Silk Road for promoting the Georgia&#39;s economic growth and development. The article notes that the process of economic integration of the region allows the increase of cargo turnover volume in Central Asia and the Caucasus countries, thus increasing the transport of goods through Georgia, - contributing to the sustainability of Georgia&#39;s macroeconomic and economic growth. The aim of financially economical models, we have identified the causal links between the sensitivity of railway cargo and the economic growth of the country. The main task of the research was to use the Railway EVA and the Georgian economy, create a cargo sensitivity relationship between CAGR models. The paper presents the analyses of the scientific research problems regarding the Railway freight transportation studies. Calculations are provided regarding the share of the Railway System in the country&#39;s GDP in period of 2006-2017 year and the average annual geometric (CAGR) growth pf cargo volumes in 16 years&rsquo; cycle allowing the &bdquo;Georgian Railway&ldquo;JSC to create the additional value in the country&#39;s overall GDP. The research indicate that the additional value to GDP is the direct and indirect form of development and growth of various sectors of the economy of Georgia, as some part of the cargo shipped in the railway remains in Georgia and is used in the process of production, which in itself adds value added to the economic growth of the country. Also, the use of this model by scientific research in foreign research centers provides better opportunities for additional growth of their economies.


Urban Science ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 117 ◽  
Author(s):  
Anselmo Pitombeira-Neto ◽  
Carlos Loureiro ◽  
Luis Carvalho

Estimation of origin–destination (OD) demand plays a key role in successful transportation studies. In this paper, we consider the estimation of time-varying day-to-day OD flows given data on traffic volumes in a transportation network for a sequence of days. We propose a dynamic linear model (DLM) in order to represent the stochastic evolution of OD flows over time. DLMs are Bayesian state-space models which can capture non-stationarity. We take into account the hierarchical relationships between the distribution of OD flows among routes and the assignment of traffic volumes on links. Route choice probabilities are obtained through a utility model based on past route costs. We propose a Markov chain Monte Carlo algorithm, which integrates Gibbs sampling and a forward filtering backward sampling technique, in order to approximate the joint posterior distribution of mean OD flows and parameters of the route choice model. Our approach can be applied to congested networks and in the case when data are available on only a subset of links. We illustrate the application of our approach through simulated experiments on a test network from the literature.


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