111 research outputs found
Heuristics Miners for Streaming Event Data
More and more business activities are performed using information systems.
These systems produce such huge amounts of event data that existing systems are
unable to store and process them. Moreover, few processes are in steady-state
and due to changing circumstances processes evolve and systems need to adapt
continuously. Since conventional process discovery algorithms have been defined
for batch processing, it is difficult to apply them in such evolving
environments. Existing algorithms cannot cope with streaming event data and
tend to generate unreliable and obsolete results.
In this paper, we discuss the peculiarities of dealing with streaming event
data in the context of process mining. Subsequently, we present a general
framework for defining process mining algorithms in settings where it is
impossible to store all events over an extended period or where processes
evolve while being analyzed. We show how the Heuristics Miner, one of the most
effective process discovery algorithms for practical applications, can be
modified using this framework. Different stream-aware versions of the
Heuristics Miner are defined and implemented in ProM. Moreover, experimental
results on artificial and real logs are reported
Clinical Processes - The Killer Application for Constraint-Based Process Interactions?
For more than a decade, the interest in aligning information
systems in a process-oriented way has been increasing. To enable operational
support for business processes, the latter are usually specified in
an imperative way. The resulting process models, however, tend to be too
rigid to meet the flexibility demands of the actors involved. Declarative
process modeling languages, in turn, provide a promising alternative in
scenarios in which a high level of flexibility is demanded. In the scientific
literature, declarative languages have been used for modeling rather simple
processes or synthetic examples. However, to the best of our knowledge,
they have not been used to model complex, real-world scenarios
that comprise constraints going beyond control-flow. In this paper, we
propose the use of a declarative language for modeling a sophisticated
healthcare process scenario from the real world. The scenario is subject to
complex temporal constraints and entails the need for coordinating the
constraint-based interactions among the processes related to a patient
treatment process. As demonstrated in this work, the selected real process
scenario can be suitably modeled through a declarative approach.Ministerio de EconomĂa y Competitividad TIN2016-76956-C3-2-RMinisterio de EconomĂa y Competitividad TIN2015-71938-RED
Ideas del alumnado de primaria y secundaria sobre aleatoriedad
En este trabajo comparamos las caracterĂsticas de las secuencias de resultados
aleatorios y distribuciones aleatorias de puntos generadas por tres grupos de alumnos
de Educación Primaria y Secundaria con las propiedades matemáticas de las mismas.
La finalidad es describir el significado personal que dichos estudiantes asignan a la
aleatoriedad.In this paper we compare the features in random sequences and random distribution
of points produced by three groups of students in Primary and Secondary Education
with the mathematical properties of the same. The aim is to describe the meaning of
randomness for these students.Facultad de EducaciĂłn y Humanidades - Campus de Melilla (Universidad de Granada)Este trabajo es parte de los proyectos SEJ2004-00789, Madrid, MCYT y FQM-126, Junta de AndalucĂ
"Delirium Day": A nationwide point prevalence study of delirium in older hospitalized patients using an easy standardized diagnostic tool
Background: To date, delirium prevalence in adult acute hospital populations has been estimated generally from pooled findings of single-center studies and/or among specific patient populations. Furthermore, the number of participants in these studies has not exceeded a few hundred. To overcome these limitations, we have determined, in a multicenter study, the prevalence of delirium over a single day among a large population of patients admitted to acute and rehabilitation hospital wards in Italy. Methods: This is a point prevalence study (called "Delirium Day") including 1867 older patients (aged 65 years or more) across 108 acute and 12 rehabilitation wards in Italian hospitals. Delirium was assessed on the same day in all patients using the 4AT, a validated and briefly administered tool which does not require training. We also collected data regarding motoric subtypes of delirium, functional and nutritional status, dementia, comorbidity, medications, feeding tubes, peripheral venous and urinary catheters, and physical restraints. Results: The mean sample age was 82.0 \ub1 7.5 years (58 % female). Overall, 429 patients (22.9 %) had delirium. Hypoactive was the commonest subtype (132/344 patients, 38.5 %), followed by mixed, hyperactive, and nonmotoric delirium. The prevalence was highest in Neurology (28.5 %) and Geriatrics (24.7 %), lowest in Rehabilitation (14.0 %), and intermediate in Orthopedic (20.6 %) and Internal Medicine wards (21.4 %). In a multivariable logistic regression, age (odds ratio [OR] 1.03, 95 % confidence interval [CI] 1.01-1.05), Activities of Daily Living dependence (OR 1.19, 95 % CI 1.12-1.27), dementia (OR 3.25, 95 % CI 2.41-4.38), malnutrition (OR 2.01, 95 % CI 1.29-3.14), and use of antipsychotics (OR 2.03, 95 % CI 1.45-2.82), feeding tubes (OR 2.51, 95 % CI 1.11-5.66), peripheral venous catheters (OR 1.41, 95 % CI 1.06-1.87), urinary catheters (OR 1.73, 95 % CI 1.30-2.29), and physical restraints (OR 1.84, 95 % CI 1.40-2.40) were associated with delirium. Admission to Neurology wards was also associated with delirium (OR 2.00, 95 % CI 1.29-3.14), while admission to other settings was not. Conclusions: Delirium occurred in more than one out of five patients in acute and rehabilitation hospital wards. Prevalence was highest in Neurology and lowest in Rehabilitation divisions. The "Delirium Day" project might become a useful method to assess delirium across hospital settings and a benchmarking platform for future surveys
Who is behind the Model? Classifying Modelers based on Pragmatic Model Features
\u3cp\u3eProcess modeling tools typically aid end users in generic, non-personalized ways. However, it is well conceivable that different types of end users may profit from different types of modeling support. In this paper, we propose an approach based on machine learning that is able to classify modelers regarding their expertise while they are creating a process model. To do so, it takes into account pragmatic features of the model under development. The proposed approach is fully automatic, unobtrusive, tool independent, and based on objective measures. An evaluation based on two data sets resulted in a prediction performance of around 90%. Our results further show that all features can be efficiently calculated, which makes the approach applicable to online settings like adaptive modeling environments. In this way, this work contributes to improving the performance of process modelers.\u3c/p\u3
Étude des mécanismes physicochimiques mis en jeu au cours de la préparation par déposition-précipitation des catalyseurs Ni/SiO
La méthode de préparation des catalyseurs Ni/Si02 par déposition- précipitation consiste à faire précipiter le nickel sur la silice grâce à la basification progressive et homogène de la solution par hydrolyse de l'urée. L'étude de l'influence des différents paramètres de la préparation montre que la nature de la phase Ni(II) supportée résulte d'une compétition cinétique entre deux réactions : i) la polymérisation Ni-Ni conduisant à la formation d'hydroxyde de nickel ; ii) la copolymérisation Ni-Si conduisant à la formation d'un phyllosilicate l:l. La cinétique de formation du phyllosilicate est contrôlée par la vitesse de dissolution de la silice
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