Merging transit schedule information with a planning network to perform dynamic multimodal assignment: lessons from a case study of the Greater Toronto and Hamilton Area

2014 ◽  
Vol 41 (10) ◽  
pp. 900-908
Author(s):  
Adam Weiss ◽  
Mohamed S. Mahmoud ◽  
Peter Kucirek ◽  
Khandker Nurul Habib
Keyword(s):  
Single Mode ◽  
User Equilibrium ◽  
Wide Spread ◽  
Complex Dynamic ◽  
Complex Models ◽  
Overall Performance ◽  
Using Data ◽  
Assignment Models ◽  
Transit Schedule

Traffic assignment has traditionally been performed using aggregate static user equilibrium approaches for a single mode. These approaches are typically favoured over more complex dynamic multimodal micro and meso-simulated models. Investigations into dynamic multimodal assignment models have shown promise, prompting interest in the adoption of complex modelling structures. The development and operation of these complex models can still be problematic, highlighting the need for efficient approaches to allow practitioners to acquire and apply these models. This paper presents a method to modify existing static auto assignment networks for dynamic multimodal assignment. To complement this, a method, which improves the overall performance of the transit routing procedure used within many assignment models, is presented. These methods were tested using data from the Greater Toronto and Hamilton Area, and result in an assignment procedure with reasonable run time and results, suggesting potential for wide spread adoption of these approaches.

scholarly journals Evaluation of Traffic Assignment Models through Simulation

2020 ◽  
Vol 12 (14) ◽  
pp. 5536 ◽  
Author(s):  
Marta Rojo
Keyword(s):  
Computer Simulation ◽  
Traffic Flow ◽  
User Equilibrium ◽  
Lower Number ◽  
Total Flow ◽  
Entire Area ◽  
Method Of Successive Averages ◽  
Assignment Models ◽  
Number Of Iterations

Assignment methodologies attempt to determine the traffic flow over each network arc based on its characteristics and the total flow over the entire area. There are several methodologies—some fast and others that are more complex and require more time to complete the calculation. In this study, we evaluated different assignment methodologies using a computer simulation and tested the results in a specific case study. The results showed that the “all-or-nothing” methods and the incremental assignment methods generally yield results with an unacceptable level of error unless the traffic is divided into four or more equal parts. The method of successive averages (MSA) was valid starting from a relatively low number of iterations, while the user equilibrium methodologies (approximated using the Frank and Wolfe algorithm) were valid starting from an even lower number of iterations. These results may be useful to researchers in the field of computer simulation and planners who apply these methodologies in similar cases.

A case study of global ULF pulsations using data from space-borne and ground-based magnetometers and a SuperDARN radar

2011 ◽  
Vol 17 (6) ◽  
pp. 54-67
Author(s):  
A.S. Potapov ◽  
◽  
E. Amata ◽  
T.N. Polyushkina ◽  
I. Coco ◽  
...  
Keyword(s):  
Using Data

The Interactional Foundations of Economic Forecasting

2018 ◽  
Author(s):  
Werner Reichmann
Keyword(s):  
Economic Forecasting ◽  
Political Actors ◽  
Social Legitimacy ◽  
Using Data ◽  
Economic Future ◽  
Economic Forecasts ◽  
Epistemic Process

How do economic forecasters produce legitimate and credible predictions of the economic future, despite most of the economy being transmutable and indeterminate? Using data from a case study of economic forecasting institutes in Germany, this chapter argues that the production of credible economic futures depends on an epistemic process embedded in various forms of interaction. This interactional foundation—through ‘foretalk’ and ‘epistemic participation’ in networks of internal and external interlocutors—sharpens economic forecasts in three ways. First, it brings to light new imaginaries of the economic future, allowing forecasters to spot emerging developments they would otherwise have missed. Second, it ensures the forecasts’ social legitimacy. And finally, it increases the forecasts’ epistemic quality by providing decentralized information about the intentions and assumptions of key economic and political actors.

scholarly journals Evaluating the Performance of Three Popular Web Mapping Libraries: A Case Study Using Argentina’s Life Quality Index

2020 ◽  
Vol 9 (10) ◽  
pp. 563
Author(s):  
Alejandro Zunino ◽  
Guillermo Velázquez ◽  
Juan Pablo Celemín ◽  
Cristian Mateos ◽  
Matías Hirsch ◽  
...  
Keyword(s):  
Life Quality ◽  
Web Technologies ◽  
Web Mapping ◽  
Network Bandwidth ◽  
Web Map ◽  
Raster Maps ◽  
Dynamic Web ◽  
Network Usage ◽  
Overall Performance

Recent Web technologies such as HTML5, JavaScript, and WebGL have enabled powerful and highly dynamic Web mapping applications executing on standard Web browsers. Despite the complexity for developing such applications has been greatly reduced by Web mapping libraries, developers face many choices to achieve optimal performance and network usage. This scenario is even more complex when considering different representations of geographical data (raster, raw data or vector) and variety of devices (tablets, smartphones, and personal computers). This paper compares the performance and network usage of three popular JavaScript Web mapping libraries for implementing a Web map using different representations for geodata, and executing on different devices. In the experiments, Mapbox GL JS achieved the best overall performance on mid and high end devices for displaying raster or vector maps, while OpenLayers was the best for raster maps on all devices. Vector-based maps are a safe bet for new Web maps, since performance is on par with raster maps on mid-end smartphones, with significant less network bandwidth requirements.

scholarly journals Extending Geodemographics Using Data Primitives: A Review and a Methodological Proposal

2021 ◽  
Vol 10 (6) ◽  
pp. 386
Author(s):  
Jennie Gray ◽  
Lisa Buckner ◽  
Alexis Comber
Keyword(s):  
Social Dynamics ◽  
Feature Space ◽  
Social Processes ◽  
Multiple Time ◽  
Current State ◽  
Cluster Label ◽  
Static Data ◽  
The Social ◽  
Using Data

This paper reviews geodemographic classifications and developments in contemporary classifications. It develops a critique of current approaches and identifiea a number of key limitations. These include the problems associated with the geodemographic cluster label (few cluster members are typical or have the same properties as the cluster centre) and the failure of the static label to describe anything about the underlying neighbourhood processes and dynamics. To address these limitations, this paper proposed a data primitives approach. Data primitives are the fundamental dimensions or measurements that capture the processes of interest. They can be used to describe the current state of an area in a multivariate feature space, and states can be compared over multiple time periods for which data are available, through for example a change vector approach. In this way, emergent social processes, which may be too weak to result in a change in a cluster label, but are nonetheless important signals, can be captured. As states are updated (for example, as new data become available), inferences about different social processes can be made, as well as classification updates if required. State changes can also be used to determine neighbourhood trajectories and to predict or infer future states. A list of data primitives was suggested from a review of the mechanisms driving a number of neighbourhood-level social processes, with the aim of improving the wider understanding of the interaction of complex neighbourhood processes and their effects. A small case study was provided to illustrate the approach. In this way, the methods outlined in this paper suggest a more nuanced approach to geodemographic research, away from a focus on classifications and static data, towards approaches that capture the social dynamics experienced by neighbourhoods.

Comparing respondents who passed versus failed an Instructional Manipulation Check: A case study about support for climate change policies

2021 ◽  
Vol 63 (4) ◽  
pp. 408-415
Author(s):  
Maria Rubio Juan ◽  
Melanie Revilla
Keyword(s):  
Climate Change ◽  
External Validity ◽  
Structural Equation ◽  
Online Survey ◽  
Equation Modeling ◽  
Manipulation Check ◽  
Climate Change Policies ◽  
Instructional Manipulation ◽  
Using Data

The presence of satisficers among survey respondents threatens survey data quality. To identify such respondents, Oppenheimer et al. developed the Instructional Manipulation Check (IMC), which has been used as a tool to exclude observations from the analyses. However, this practice has raised concerns regarding its effects on the external validity and the substantive conclusions of studies excluding respondents who fail an IMC. Thus, more research on the differences between respondents who pass versus fail an IMC regarding sociodemographic and attitudinal variables is needed. This study compares respondents who passed versus failed an IMC both for descriptive and causal analyses based on structural equation modeling (SEM) using data from an online survey implemented in Spain in 2019. These data were analyzed by Rubio Juan and Revilla without taking into account the results of the IMC. We find that those who passed the IMC do differ significantly from those who failed for two sociodemographic and five attitudinal variables, out of 18 variables compared. Moreover, in terms of substantive conclusions, differences between those who passed and failed the IMC vary depending on the specific variables under study.

Foreign Aid and its Role in Maintaining the Exploitation of the Agricultural Sector: Evidence from a Case Study in Africa

1983 ◽  
Vol 13 (1) ◽  
pp. 33-49 ◽  
Author(s):  
Claudio Schuftan
Keyword(s):  
Rural Development ◽  
Foreign Aid ◽  
Local Governments ◽  
Agricultural Sector ◽  
National Development ◽  
The Other ◽  
Sizable Proportion ◽  
Using Data ◽  
State Of Affairs

Today most foreign aid donors are genuinely committed to the idea that development in Third World countries should start with rural development. Therefore, a sizable proportion of their development funds are invested in rural projects. However, donors channel these funds through local governments (most often representing local bourgeois interests) that are not as committed to the principle of rural development. These governments are often also embarked in policies that are actually—directly or indirectly—expropriating the surpluses generated by agriculture and investing them in the other sectors of the economy. The peasants are therefore footing most of the bill of overall national development. This paper contends that, because of this state of affairs, foreign aid directed toward rural development is actually filling the investment gap left by an internal system of unequal returns to production in agriculture. In so doing, foreign aid is indirectly financing the development of the other sectors of the economy, even if this result is unintended. This perpetrates maldevelopment without redressing the basic exploitation process of peasants which lies at the core of underdevelopment. Evidence to support this hypothesis is presented using data from a primarily agricultural exporting country: the United Republic of Cameroon.

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