2,716 research outputs found
Incremental Predictive Process Monitoring: How to Deal with the Variability of Real Environments
A characteristic of existing predictive process monitoring techniques is to
first construct a predictive model based on past process executions, and then
use it to predict the future of new ongoing cases, without the possibility of
updating it with new cases when they complete their execution. This can make
predictive process monitoring too rigid to deal with the variability of
processes working in real environments that continuously evolve and/or exhibit
new variant behaviors over time. As a solution to this problem, we propose the
use of algorithms that allow the incremental construction of the predictive
model. These incremental learning algorithms update the model whenever new
cases become available so that the predictive model evolves over time to fit
the current circumstances. The algorithms have been implemented using different
case encoding strategies and evaluated on a number of real and synthetic
datasets. The results provide a first evidence of the potential of incremental
learning strategies for predicting process monitoring in real environments, and
of the impact of different case encoding strategies in this setting
Clustering-Based Predictive Process Monitoring
Business process enactment is generally supported by information systems that
record data about process executions, which can be extracted as event logs.
Predictive process monitoring is concerned with exploiting such event logs to
predict how running (uncompleted) cases will unfold up to their completion. In
this paper, we propose a predictive process monitoring framework for estimating
the probability that a given predicate will be fulfilled upon completion of a
running case. The predicate can be, for example, a temporal logic constraint or
a time constraint, or any predicate that can be evaluated over a completed
trace. The framework takes into account both the sequence of events observed in
the current trace, as well as data attributes associated to these events. The
prediction problem is approached in two phases. First, prefixes of previous
traces are clustered according to control flow information. Secondly, a
classifier is built for each cluster using event data to discriminate between
fulfillments and violations. At runtime, a prediction is made on a running case
by mapping it to a cluster and applying the corresponding classifier. The
framework has been implemented in the ProM toolset and validated on a log
pertaining to the treatment of cancer patients in a large hospital
Explain, Adapt and Retrain: How to improve the accuracy of a PPM classifier through different explanation styles
Recent papers have introduced a novel approach to explain why a Predictive
Process Monitoring (PPM) model for outcome-oriented predictions provides wrong
predictions. Moreover, they have shown how to exploit the explanations,
obtained using state-of-the art post-hoc explainers, to identify the most
common features that induce a predictor to make mistakes in a semi-automated
way, and, in turn, to reduce the impact of those features and increase the
accuracy of the predictive model. This work starts from the assumption that
frequent control flow patterns in event logs may represent important features
that characterize, and therefore explain, a certain prediction. Therefore, in
this paper, we (i) employ a novel encoding able to leverage DECLARE constraints
in Predictive Process Monitoring and compare the effectiveness of this encoding
with Predictive Process Monitoring state-of-the art encodings, in particular
for the task of outcome-oriented predictions; (ii) introduce a completely
automated pipeline for the identification of the most common features inducing
a predictor to make mistakes; and (iii) show the effectiveness of the proposed
pipeline in increasing the accuracy of the predictive model by validating it on
different real-life datasets
University commuting during the COVID-19 pandemic: Changes in travel behaviour and mode preferences
One prominent change induced by the COVID-19 pandemic concerns the worldwide use of public transportation for commuting purposes. This study focused on university commuting in Italy by examining the propensity to change transport modes under different infection risk scenarios. Data were collected in 2020 through an online survey of college mobility conducted by the Italian University Network for Sustainable Development. Asking the respondents to consider both a pessimistic and an optimistic scenario, with respect to the risk odds of being infected, we followed a two-step approach to study the prospective travel habits of college users. First, we tested a logit model to estimate the propensity to abandon one's pre-COVID-19 commuting mode. Then, we investigated the factors influencing the choice of switching from public transportation to either cars or active modes by estimating a multinomial logit model. By exploiting the novelty of considering two risk scenarios, this study highlighted that, especially in the pessimistic case, the change to active modes was constrained by spatial aspects in favour of motorized vehicles. From a policy perspective, this COVID-19-based natural experiment advocates transportation authorities taking effective actions to ensure that, in case of emergencies, a modal shift would not benefit more-polluting transport means
Genetic algorithms for hyperparameter optimization in predictive business process monitoring
Predictive business process monitoring exploits event logs to predict how ongoing (uncompleted) traces will unfold up to their completion. A predictive process monitoring framework collects a range of techniques that allow users to get accurate predictions about the achievement of a goal for a given ongoing trace. These techniques can be combined and their parameters configured in different framework instances. Unfortunately, a unique framework instance that is general enough to outperform others for every dataset, goal or type of prediction is elusive. Thus, the selection and configuration of a framework instance needs to be done for a given dataset. This paper presents a predictive process monitoring framework armed with a hyperparameter optimization method to select a suitable framework instance for a given dataset
Process Discovery on Deviant Traces and Other Stranger Things
As the need to understand and formalise business processes into a model has grown over the last years, the process discovery research field has gained more and more importance, developing two different classes of approaches to model representation: procedural and declarative. Orthogonally to this classification, the vast majority of works envisage the discovery task as a one-class supervised learning process guided by the traces that are recorded into an input log.
In this work instead, we focus on declarative processes and embrace the less-popular view of process discovery as a binary supervised learning task, where the input log reports both examples of the normal system execution, and traces representing a “stranger” behaviour according to the domain semantics. We therefore deepen how the valuable information brought by both these two sets can be extracted and formalised into a model that is “optimal” according to user-defined goals. Our approach, namely NegDis, is evaluated w.r.t. other relevant works in this field, and shows promising results regarding both the performance and the quality of the obtained solution
Outcome-Oriented Prescriptive Process Monitoring Based on Temporal Logic Patterns
Prescriptive Process Monitoring systems recommend, during the execution of a
business process, interventions that, if followed, prevent a negative outcome
of the process. Such interventions have to be reliable, that is, they have to
guarantee the achievement of the desired outcome or performance, and they have
to be flexible, that is, they have to avoid overturning the normal process
execution or forcing the execution of a given activity. Most of the existing
Prescriptive Process Monitoring solutions, however, while performing well in
terms of recommendation reliability, provide the users with very specific
(sequences of) activities that have to be executed without caring about the
feasibility of these recommendations. In order to face this issue, we propose a
new Outcome-Oriented Prescriptive Process Monitoring system recommending
temporal relations between activities that have to be guaranteed during the
process execution in order to achieve a desired outcome. This softens the
mandatory execution of an activity at a given point in time, thus leaving more
freedom to the user in deciding the interventions to put in place. Our approach
defines these temporal relations with Linear Temporal Logic over finite traces
patterns that are used as features to describe the historical process data
recorded in an event log by the information systems supporting the execution of
the process. Such encoded log is used to train a Machine Learning classifier to
learn a mapping between the temporal patterns and the outcome of a process
execution. The classifier is then queried at runtime to return as
recommendations the most salient temporal patterns to be satisfied to maximize
the likelihood of a certain outcome for an input ongoing process execution. The
proposed system is assessed using a pool of 22 real-life event logs that have
already been used as a benchmark in the Process Mining community.Comment: 38 pages, 6 figures, 8 table
Integrated chemical status of the Italian marine waters sensu Descriptor 8 of the Marine Strategy Framework Directive
The European Marine Strategy Framework Directive (MSFD) required Member States to define the concept of Good Environmental Status (GES) of their marine waters in quantitative terms and to achieve it through the assessment of 11 descriptors by 2020. ISPRA (Italian Institute for Environmental Protection and Research), on behalf of the Ministry of the Environment, carried out the Initial
Assessment (2012) and the evaluation of the first cycle of the MSFD (2012–2018) to understand the achievement of GES Descriptor 8 (“Contaminant concentrations are at levels that do not give rise to pollution effects”) and, now, in this second cycle of the MSFD (2018–2024), is conducting monitoring of D8C1 criterion elements (“Contaminant concentrations”). In this paper, the approach, integrating data on chemical contaminants (metals and polycyclic aromatic hydrocarbons and organochlorine compounds) in different matrices (water, sediment and biota), adopted by Italy since 2012 to study GES for the MSFD-D8C1 criterion in national marine water is described. This approach, based on the use of a dimensionless, zero-centered index, allows one to assess all regulatory contaminants as a whole. The improvements in the monitoring strategy and the GES evaluation between the Initial Assessment, the first cycle, and the beginning of the second cycle of the MSFD for the Adriatic Sea subregion are presented
Hypertension-induced posterior reversible encephalopathy syndrome as the presentation of progressive bilateral renal artery stenosis
SummaryPosterior reversible encephalopathy syndrome (PRES) is characterized clinically by headache, altered mental status, visual loss, and seizures. PRES is associated with neuroradiological findings characterized by white matter abnormalities, predominantly in the parieto-occipital regions of the brain. PRES is most often described in cases of hypertensive encephalopathy, eclampsia, renal failure, and immunosuppressive or anticancer therapy. We report a case of PRES associated with severe hypertension in the setting of a progressive renovascular hypertension from bilateral atherosclerotic renal artery stenosis. The pathogenesis of PRES is discussed and the importance of a prompt diagnosis and treatment is emphasized
Discovering Business Processes models expressed as DNF or CNF formulae of Declare constraints
In the field of Business Process Management, the Process Discovery task is one of the most important and researched topics. It aims to automatically learn process models starting from a given set of logged execution traces. The majority of the approaches employ procedural languages for describing the discovered models, but declarative languages have been proposed as well. In the latter category there is the Declare language, based on the notion of constraint, and equipped with a formal semantics on LTLf. Also, quite common in the field is to consider the log as a set of positive examples only, but some recent approaches pointed out that a binary classification task (with positive and negative examples) might provide better outcomes. In this paper, we discuss our preliminary work on the adaptation of some existing algorithms for Inductive Logic Programming, to the specific setting of Process Discovery: in particular, we adopt the Declare language with its formal semantics, and the perspective of a binary classification task (i.e., with positive and negative examples
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