PERRAKIS, Konstantinos; KARLIS, Dimitris; COOLS, Mario; JANSSENS, Davy
Transportation origin-destination analysis is investigated through the use of Poisson mixtures by introducing covariate-based models which incorporate different transport modelling phases and also allow for direct probabilistic inference on link traffic based on Bayesian predictions. Emphasis is placed on the Poisson-inverse Gaussian model as an alternative to the commonly used Poisson-gamma and Poisson-log-normal models. We present a first full Bayesian formulation and demonstrate that the Poisson-inverse Gaussian model is particularly suited for origin-destination analysis because of its desirable marginal and hierarchical properties. In addition, the integrated nested Laplace approximation is considered as an alternative to Markov chain Monte Carlo sampling...
MARTIN, Niels; DEPAIRE, Benoit; CARIS, An
This paper focuses on the potential of process mining to support the construction of business process simulation (BPS) models. To date, research efforts are scarce and have a rather conceptual nature. Moreover, publications fail to explicit the complex internal structure of a simulation model. The current paper outlines the general structure of a BPS model. Building on these foundations, modeling tasks for the main components of a BPS model are identified. Moreover, the potential value of process mining and the state of the art in literature are discussed. Consequently, a multitude of promising research challenges are identified. In this sense,...
JOUCK, Toon; Depaire, Benoit
Past research revealed issues with artificial event data used for comparative analysis of process mining algorithms. The aim of this research is to design, implement and validate a framework for producing artificial event logs which should increase discriminatory power of artificial event logs when evaluating process discovery techniques.
Pirdavani, Ali; Magis, Maarten; De Pauw, Ellen; Daniels, Stijn; Bellemans, Tom; Brijs, Tom; Wets, Geert
There is a growing trend in development and application of real-time crash risk prediction models within dynamic safety management systems. These real-time crash risk prediction models are constructed by associating crash data with the real-time traffic surveillance data, collected by loop detectors. The objective of this paper is to develop a real-time prediction model that will potentially be utilized within safety management systems. This model aims to predict the traffic safety condition of a motorway. Given that the dependent variable (i.e. traffic safety condition) is considered dichotomous (“no-crash” or “crash”), the binary logistic regression technique is selected for model development....
Pirdavani, Ali; De Pauw, Ellen; Daniels, Stijn; Magis, Maarten; Brijs, Tom; Bellemans, Tom; Wets, Geert
There is a growing trend in development and application of real-time crash prediction models within dynamic safety management systems. These real-time crash prediction models are constructed by associating crash data with the real-time traffic surveillance data (e.g. collected by loop detectors). The crash and traffic data used in this study were collected between June 2009 and December 2011 on a part of the E313 motorway in Belgium between Geel-East and Antwerp-East exits, on the direction towards Antwerp. The main objective of this paper is to develop a real-time prediction model that will potentially be utilized within traffic management systems. This...
DONS, Evi; KOCHAN, Bruno; BELLEMANS, Tom; WETS, Geert; INT PANIS, Luc
The AB2C model (Activity-Based modeling framework for Black Carbon exposure assessment) was developed to assess personal exposure to air pollution, more specifically black carbon. Currently the model calculates exposure in Flanders, an urbanized region in Western Europe. This model is characterized by the use of time-activity patterns, and air pollution concentrations with a high spatial and temporal resolution, including indoors and in the transport microenvironment. This model can be used for disaggregated exposure assessment or the evaluation of policy scenarios. In this paper, exposure of people from a lower socioeconomic class (SEC) is compared to the exposure of people from...
Cho, Sungjin; Bellemans, Tom; Janssens, Davy; Wets, Geert
This study proposes integrating GIS and FEATHERS in order to improve the capability of data management, spatial analysis and
visualization in the model framework. GIS provides geodatabase for effectively storing and edit (non-)spatial data, useful
functions of spatial analysis for defining spatial interactions between phenomena simulated by the modeling system, and
interactive visualization tools. Thus, this study mainly focuses on three topics: i) why FEATHERS needs a GIS module, ii) how
the GIS module is designed, and iii) what functions can be supported by the GIS module in the FEATHERS system. Moreover,
we overview some transportation software adopting GIS to...
JANS, Mieke; Alles, Michael G.; Vasarhelyi, Miklos A.
There is a large body of accounting research literature examining the use of analytical procedures by auditors and proposing either new types of analytical procedures or more effective ways of implementing existing procedures. In this paper, we demonstrate using procurement data from a leading global bank the value added in an audit setting of a new type of analytical procedure: process mining of event logs. In particular, using process mining, we are able to identify numerous transactions that we consider to be audit-relevant information, including payments made without approval, violations of segregation of duty controls, and violations of company-specific internal...
SWENNEN, Marijke; DEPAIRE, Benoit; JANS, Mieke; VANHOOF, Koen
Testing and controlling business processes, activities, data and results is becoming increasingly important for companies. Based on the literature, business tests can be divided into three domains, i.e. performance, risk and compliance and separate domain-specific frameworks have been developed. These different domains and frameworks hint at some aspects that need to be taken into account when managing business tests in a company. In this paper we identify the most important concepts concerning business tests and their management and we provide a first conceptual business test model. We do this based on an archival research study in which we analyse business...
Bao, Qiong; Kochan, Bruno; Bellemans, Tom; Janssens, Davy; Wets, Geert
FEATHERS is an activity-based micro-simulation modeling framework used for transport demand forecasting. Currently, this framework is implemented for the Flanders region of Belgium and the most detailed travel demand data can be obtained at the Subzone level, which consists of 2,386 virtual units with an average area of 5.8 km2. In this study, we investigated the transferability of applying the FEATHERS framework from the Subzone zoning system to a more disaggregated zoning system, i.e., Building block (BB), which is the most detailed geographical level currently applicable in Belgium consisting of 10,521 units with an average area of 1.3 km2. In...
Knapen, Luk; Bellemans, Tom; Usman, Muhammad; Janssens, Davy; Wets, Geert
The concept of rescheduling is essential to activity-based modeling in order to calculate effects of both unexpected incidents and adaptation of individuals to traffic demand management measures. When collaboration between individuals is involved or timetable based public transportation modes are chosen, rescheduling becomes complex. This paper describes a new framework to investigate algorithms for rescheduling at a large scale. The framework allows to explicitly model the information flow between traffic information services and travelers. It combines macroscopic traffic assignment with microscopic simulation of agents adapting their schedules. Perception filtering is introduced to allow for traveler specific interpretation of perceived macroscopic...
BAO, Qiong; SHEN, Yongjun; KOCHAN, Bruno; BELLEMANS, Tom; JANSSENS, Davy; WETS, Geert
Knapen, Luk; Bellemans, Tom; Janssens, Davy; Wets, Geert
There are multiple ways to split a path in a directed graph into largest sub-paths of minimal cost. All possible splits constitute path partitions of the same size. By calculating two specific path splittings, it is possible to identify subsets of the vertices (splitVer- texSets) that can be used to generate every possible path splitting by taking one vertex from each such subset and connecting the resulting vertices by a least cost path. This is interesting in transportation science when investigating the hypothesis that people build up their route from least cost components. The splitVertexSets can be easily and efficiently...
HUSSAIN, Iftikhar; KNAPEN, Luk; Galland, S.; JANSSENS, Davy; BELLEMANS, Tom; YASAR, Ansar; WETS, Geert
In the carpooling, individuals need to communicate, negotiate and in most cases adapt their daily schedule to enable cooperation.
Through negotiation, agents (individuals) can reach complex agreements in an iterative way which meet the criteria for
successful negotiation. The result of the negotiation depends on “negotiation mechanism” used to match and on the behavior of
the agents involved in the negotiation process. This paper presents an organizational and agent-based model for commuting by
candidate carpoolers using a simple negotiation mechanism aimed at finding an acceptable agreement between agents to carpool.
Initially, the agents involved in exploration process, search for their partners via some...
NEVEN, An; BELLEMANS, Tom; JANSSENS, Davy; WETS, Geert
MARTIN, Niels; DEPAIRE, Benoit; CARIS, An
Business process simulation models are typically built using model construction inputs such as documentation, interviews and observations. Due to issues with these information sources, efforts to further improve the realism of simulation models are valuable. Within this context, the present paper focuses on the use of process execution data in simulation model construction. More specifically, the behaviour of contemporary business processes is increasingly registered in event logs by process-aware information systems. Knowledge can be extracted from these log files using process mining techniques. This paper advocates the addition of event log knowledge as a model construction input, complementary to traditional...
Estrella-Ramon, A. M.; Sanchez-Perez, M.; SWINNEN, Gilbert; VANHOOF, Koen
Throughout this research the customer valuation trend in marketing is going to be reviewed, emphasizing Customer Lifetime Value and Customer Equity measures. The main theoretical contributions in the development and evolution of the Customer Lifetime Value concept are analysed. Customer Lifetime Value is also differentiated from Customer Equity and Customer Profitability analysis to estimate customer value in terms of firm profitability. Customer Lifetime Value and Customer Equity concepts are formally defined. Additionally, a classification of a set of published researches into Customer Lifetime Value and/or Customer Equity is developed. This classification has been posited according to several criteria that serves...
CREEMERS, Lieve; WETS, Geert; COOLS, Mario
PIRDAVANI, Ali; BELLEMANS, Tom; BRIJS, Tom; KOCHAN, Bruno; WETS, Geert
Travel demand management (TDM) consists of a variety of policy measures that affect the effectiveness of transportation systems by changing travel behavior. The primary objective of such TDM strategies is not to improve traffic safety, although their impact on traffic safety should not be neglected. The main purpose of this study is to simulate the traffic safety impact of conducting a teleworking scenario (i.e. 5% of the working population engages in teleworking) in the study area, Flanders, Belgium. Since TDM strategies are usually conducted at a geographically aggregated level, crash prediction models should also be developed at an aggregate level....
DEPAIRE, Benoit; CARIS, An
Vehicle Routing Problems (VRP) are an extensively studied class of combinatorial optimization problems, with a wide spectrum of real-life applications. An impressive number of heuristic procedures have been proposed for VRP problems. However, no common, agreed-upon methodology is used to compare heuristic performance on vehicle routing problems. In VRP literature, (meta-)heuristics are rarely compared by means of statistical techniques. In this paper a methodological framework is proposed to optimize and compare heuristic algorithms. The optimization of algorithms relates both to setting the optimal algorithmic parameter values and testing the effects of various components of an algorithm. The methodological framework is...