An experimental investigation of calibration techniques for imbalanced data

Calibration is a technique used to obtain accurate probability estimation for classification problems in real applications. Class imbalance can create considerable challenges in obtaining accurate probabilities for calibration methods. However, previous research has paid little attention to this issue. In this paper, we present an experimental investigation of some prevailing calibration methods in different imbalance scenarios. Several performance metrics are considered to evaluate different aspects of calibration performance. The experimental results show that the performance of different calibration techniques depends on the metrics and the degree of the imbalance ratio. Isotonic Regression has better overall performance on imbalanced datasets than parametric and other complex non-parametric methods. However, it performs unstably in highly imbalanced scenarios. This study provides some insights into calibration methods on imbalanced datasets, and it can be a reference for the future development of calibration methods in class imbalance scenarios

A Framework for Online Conformance Checking

Conformance checking – a branch of process mining – focuses on establishing to what extent actual executions of a process are in line with the expected behavior of a reference model. Current conformance checking techniques only allow for a-posteriori analysis: the amount of (non-)conformant behavior is quantified after the completion of the process instance. In this paper we propose a framework for online conformance checking: not only do we quantify (non-)conformant behavior as the execution is running, we also restrict the computation to constant time complexity per event analyzed, thus enabling the online analysis of a stream of events. The framework is instantiated with ideas coming from the theory of regions, and state similarity. An implementation is available in ProM and promising results have been obtained.Peer ReviewedPostprint (author's final draft

PARASO, a circum-Antarctic fully coupled ice-sheet–ocean–sea-ice–atmosphere–land model involving f.ETISh1.7, NEMO3.6, LIM3.6, COSMO5.0 and CLM4.5

We introduce PARASO, a novel five-component fully coupled regional climate model over an Antarctic circumpolar domain covering the full Southern Ocean. The state-of-the-art models used are the fast Elementary Thermomechanical Ice Sheet model (f.ETISh) v1.7 (ice sheet), the Nucleus for European Modelling of the Ocean (NEMO) v3.6 (ocean), the Louvain-la-Neuve sea-ice model (LIM) v3.6 (sea ice), the COnsortium for Small-scale MOdeling (COSMO) model v5.0 (atmosphere) and its CLimate Mode (CLM) v4.5 (land), which are here run at a horizontal resolution close to . One key feature of this tool resides in a novel two-way coupling interface for representing ocean–ice-sheet interactions, through explicitly resolved ice-shelf cavities. The impact of atmospheric processes on the Antarctic ice sheet is also conveyed through computed COSMO-CLM–f.ETISh surface mass exchange. In this technical paper, we briefly introduce each model's configuration and document the developments that were carried out in order to establish PARASO. The new offline-based NEMO–f.ETISh coupling interface is thoroughly described. Our developments also include a new surface tiling approach to combine open-ocean and sea-ice-covered cells within COSMO, which was required to make this model relevant in the context of coupled simulations in polar regions. We present results from a 2000–2001 coupled 2-year experiment. PARASO is numerically stable and fully operational. The 2-year simulation conducted without fine tuning of the model reproduced the main expected features, although remaining systematic biases provide perspectives for further adjustment and development

An activity theory based approach for ontological modelling of collaborative logistics process dynamics

ABSTRACTThe aspect of collaboration is gaining a considerable amount of importance in current logistics operations. The large number of dynamics that arise in collaborative logistics processes with numerous complexities and variations can make the modelling of such collaborative logistics processes a challenging task. Hence, a systematic modelling approach is required to make sense of the enormous amount of unorganised process information. In this paper, we present an ontological method for modelling the dynamics within collaborative logistics processes. An activity theory-guided approach is employed to elicit the process information, which is then formalised using an ontological model. Dynamic adaptations for the collaborative logistics process operations are supported through an instance level inference of the model. The applicability of the method is demonstrated by means of a case study.doi: 10.1080/13675567.2018.1535650 ABSTRACTThe aspect of collaboration is gaining a considerable amount of importance in current logistics operations. The large number of dynamics that arise in collaborative logistics processes with numerous complexities and variations can make the modelling of such collaborative logistics processes a challenging task. Hence, a systematic modelling approach is required to make sense of the enormous amount of unorganised process information. In this paper, we present an ontological method for modelling the dynamics within collaborative logistics processes. An activity theory-guided approach is employed to elicit the process information, which is then formalised using an ontological model. Dynamic adaptations for the collaborative logistics process operations are supported through an instance level inference of the model. The applicability of the method is demonstrated by means of a case study.status: Published onlin

Incorporating negative information to process discovery of complex systems

The discovery of a formal process model from event logs describing real process executions is a challenging problem that has been studied from several angles. Most of the contributions consider the extraction of a model as a one-class supervised learning problem where only a set of process instances is available. Moreover, the majority of techniques cannot generate complex models, a crucial feature in some areas like manufacturing. In this paper we present a fresh look at process discovery where undesired process behaviors can also be taken into account. This feature may be crucial for deriving process models which are less complex, fitting and precise, but also good on generalizing the right behavior underlying an event log. The technique is based on the theory of convex polyhedra and satisfiability modulo theory (SMT) and can be combined with other process discovery approach as a post processing step to further simplify complex models. We show in detail how to apply the proposed technique in combination with a recent method that uses numerical abstract domains. Experiments performed in a new prototype implementation show the effectiveness of the technique and the ability to be combined with other discovery techniques.status: publishe

On the gap between reality and registration: a business event analysis classification framework

This paper presents a business event analysis classification framework, based on five business criteria. As a result, we are able to distinguish thirteen event types distributed over four categories, i.e. truthful, invisible, false and unobserved events. Currently, several of these event types are not commonly dealt with in business process management (BPM) and analytics (BPA) research. Based on the proposed framework we situate the different BPM and BPA research areas and indicate the potential issues for each field. A business case is elaborated to demonstrate the relevance of the event classification framework

Disputatio de nobilitate ... sub præsidio ... Andreæ Norcopensis ... publico examini oblata â Ludovico Tolstadio Holm: ad diem 22 Mart. 1676. In audit. Gustav. major. horis ante meridiem consvetis.

status: publishe

Naar een globaal sportinfrastructuurplan in Vlaanderen: Kaartenboek over- en ondervertegenwoordiging

BMS Studie 32 omvat het kaartenboek als bijlage bij de studie 'Naar een Globaal Sportinfrastructuurplan in Vlaanderen. Onderzoek naar behoeften inzake sportinfrastructuur, ontwikkelen van een strategische visie en aanreiken van beleidsaanbevelingen' (BMS Studie 31). Hierin kunnen alle kaarten met betrekking tot de onder- en oververtegenwoordiging van sportinfrastructuur in Vlaanderen geraadpleegd worden. Er is ook een Managementsamenvatting van het onderzoek beschikbaar