Papers by Sowjanya Dhulipala
Tourism Analysis
The study aims to model the initial international spread of Coronavirus Disease 2019 (COVID-19) a... more The study aims to model the initial international spread of Coronavirus Disease 2019 (COVID-19) and analyse the risk of early initial spread using data from 105 countries. A generalised linear model (GLM) is developed to analyse the relationship between the initial international spread and its factors. Findings showed that the countries with high tourism activity are affected early by COVID-19, and countries with a better-quality healthcare system can adequately detect the spread. Countries that have promptly restricted air passengers have experienced a delay in the initial international spread. A regression analysis of fatalities during the initial stage suggested that the countries with an early initial spread of COVID-19 coupled with a high proportion of the elderly population possess a relatively high risk of fatalities. The study provides insights into the factors influencing the initial international spread of contagious diseases and the effect of air travel restrictions on th...
Transportation, Jan 18, 2022
In this paper, regional freight generation models are developed for twenty industry sectors in a ... more In this paper, regional freight generation models are developed for twenty industry sectors in a region comprising 101 districts of India using secondary data. We provide insights into investigating spatial dependencies, identifying the type of spatial interactions present, and adopting appropriate spatial models. Non-spatial and spatial regression models are developed, addressing different spatial interactions. The roles of economic, locational, geographical, and transportation infrastructure variables in estimating freight production and addressing spatial autocorrelation are explored. Sectoral employment, an economic variable, is found significant in estimating freight production of 20 sectors considered. Locational, geographical, and transportation infrastructure variables helped to address spatial autocorrelation for some sectors. Spatial analysis showed correlated effects and endogenous spatial interactions with global spillover feedback, suggesting that spatial error and spatial lag models are appropriate. The study framework can help researchers and planners in correcting for spatial autocorrelation while modelling freight generation. The study forms a paradigm of freight generation modelling with the available secondary data in the absence of comprehensive freight databases and systematic modelling frameworks.
Transport Policy, 2020
Abstract Freight transportation has a key role in the economic competitiveness of any nation. Ind... more Abstract Freight transportation has a key role in the economic competitiveness of any nation. India is one of the fastest growing nations in the world; its agricultural sector plays a vital role in contributing to the country's economy. In this paper, the freight production in the agricultural sector of India is modelled using multiple linear regression (MLR) and generalized additive modelling (GAM) approaches. Using district-level data, factors influencing agricultural freight production are identified and the relationship between them is modelled. The study considered 210 districts of eight states covering South India and parts of Central and Western India. Population, employment in the agricultural sector, gross cropped area and gross irrigated area are identified as influential factors. GAM approach is a flexible method which can predict non-linear responses for the given predictor variables by allowing non-linear functions for each of them while maintaining additivity. The applicability of GAM in modelling freight production while tackling non-linear effects of predictor variables on freight production is investigated and encouraging results are achieved. The results revealed that both MLR and GAM models have good modelling efficiency, however, GAM model outperformed the MLR model in both fitting and predicting. The study can be used in evaluating the commodity movements and transportation demand which in turn will help in decision-making for the provision of freight transportation facilities and policymaking.
Transportation Research Procedia
Abstract The study presents the route choice behaviour among three alternative routes for a set o... more Abstract The study presents the route choice behaviour among three alternative routes for a set of origin and destination points of Surat, a metropolitan city of India. Travel time, traffic congestion level and environmental effects along the routes are considered as the main decisive factors for the route choice in metropolitan mixed traffic environment. The neuro-fuzzy hybrid approach is used in model building here, which couples the traditional fuzzy logic with neural nets’ training capabilities to compose the fuzzy logic’s knowledge base and fuzzy sets’ parameters optimally. The developed model has shown improved results over basic fuzzy modelling to address the uncertainty in choice decisions and is able to map the choice behaviour in a realistic way.
Transportation in Developing Economies
The productivity of most of the public transport services has greatly reduced due to the absence ... more The productivity of most of the public transport services has greatly reduced due to the absence of appropriate transit planning strategies. The efficacy of public transport system is undoubtedly governed by transit accessibility, and provision of transit supply and service facilities by transport organizations. If a transit system, and its operations prove to be inefficient, its patronage shifts towards private mode or para-transit, resulting in an uneconomical and environmentally degraded system. Therefore, the identification of attributes influencing consumers’ choice of transit system becomes an important aspect in urban context. The conventional Logit modelling approach, based on the theory of random utility maximization has been attempted by many. Moreover, the approach possesses certain limitations in addressing the uncertainty lying in humans’ choice decisions and ambiguous expressions made by travellers for the available options. Whereas, Fuzzy Logic, an Artificial Intelligence technique works on the principle of simple and logical ‘If-Then’ rules, framed to predict the preferred choice through approximate reasoning. The study precisely attempts to analyze the transit choice behaviour of urbanites, with the help of fuzzy rule based transit choice model, considering Surat, a fast developing Indian metropolitan city in the state of Gujarat as the study area. Walking distance to a bus stop, waiting time at a bus stop, and bus schedule reliability are observed to be the governing accessibility attributes, and thus are considered further for model development. Furthermore, sensitivity analysis showing the impacts of accessibility attributes on transit shift is carried out as an application of the developed model.
Transportation Research Procedia
European Transport/Trasporti Europei
Route choice plays a vital role in the traffic assignment and network building, as it involves de... more Route choice plays a vital role in the traffic assignment and network building, as it involves decision making on part of riders. The vagueness in travellers’ perceptions of attributes of the available routes between any two locations adds to the complexities in modelling the route choice behaviour. Conventional Logit models fail to address the uncertainty in travellers’ perceptions of route characteristics (especially qualitative attributes, such as environmental effects), which can be better addressed through the theory of fuzzy sets and linguistic variables. This study thus attempts to model travellers’ route choice behaviour, using a fuzzy logic approach that is based on simple and logical ‘if-then’ linguistic rules. This approach takes into consideration the uncertainty in travellers’ perceptions of route characteristics, resembling humans’ decision-making process. Three attributes – travel time, traffic congestion, and road-side environment are adopted as factors driving peopl...
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Papers by Sowjanya Dhulipala