Search results for "Mach"
showing 10 items of 3360 documents
One-Counter Verifiers for Decidable Languages
2013
Condon and Lipton (FOCS 1989) showed that the class of languages having a space-bounded interactive proof system (IPS) is a proper subset of decidable languages, where the verifier is a probabilistic Turing machine. In this paper, we show that if we use architecturally restricted verifiers instead of restricting the working memory, i.e. replacing the working tape(s) with a single counter, we can define some IPS’s for each decidable language. Such verifiers are called two-way probabilistic one-counter automata (2pca’s). Then, we show that by adding a fixed-size quantum memory to a 2pca, called a two-way one-counter automaton with quantum and classical states (2qcca), the protocol can be spac…
The impact of feature extraction on the performance of a classifier : kNN, Naïve Bayes and C4.5
2005
"The curse of dimensionality" is pertinent to many learning algorithms, and it denotes the drastic raise of computational complexity and the classification error in high dimensions. In this paper, different feature extraction techniques as means of (1) dimensionality reduction, and (2) constructive induction are analyzed with respect to the performance of a classifier. Three commonly used classifiers are taken for the analysis: kNN, Naïve Bayes and C4.5 decision tree. One of the main goals of this paper is to show the importance of the use of class information in feature extraction for classification and (in)appropriateness of random projection or conventional PCA to feature extraction for …
Improving Nearest Neighbor Based Multi-target Prediction Through Metric Learning
2017
The purpose of this work is to learn specific distance functions to be applied for multi-target regression problems using nearest neighbors. The idea of preserving the order relation between input and output vectors considering their corresponding distances is used along a maximal margin criterion to formulate a specific metric learning problem. Extensive experiments and the corresponding discussion try to put forward the advantages of the proposed algorithm that can be considered as a generalization of previously proposed approaches. Preliminary results suggest that this line of work can lead to very competitive algorithms with convenient properties.
Evaluation of a Support Vector Machine Based Method for Crohn’s Disease Classification
2019
Crohn’s disease (CD) is a chronic, disabling inflammatory bowel disease that affects millions of people worldwide. CD diagnosis is a challenging issue that involves a combination of radiological, endoscopic, histological, and laboratory investigations. Medical imaging plays an important role in the clinical evaluation of CD. Enterography magnetic resonance imaging (E-MRI) has been proven to be a useful diagnostic tool for disease activity assessment. However, the manual classification process by expert radiologists is time-consuming and expensive. This paper proposes the evaluation of an automatic Support Vector Machine (SVM) based supervised learning method for CD classification. A real E-…
Energy recovery from rectangular weirs in wastewater treat-ment plants
2022
Hydraulic turbines for energy recovery in wastewater treatment plants, with relatively large discharges and small head jumps, are usually screw or Kaplan types. In the specific case of a small head jump (about 3 m) underlying a rectangular weir in the major Palermo (Italy) treat-ment plant, a traditional Kaplan solution is compared with two other ones: a Hydrostatic Pres-sure Machine (HPM) located in the upstream channel and a cross-flow turbine located in a specif-ic underground room downstream the same channel.
How adolescents navigate Wikipedia to answer questions / ¿Cómo navegan los adolescentes en Wikipedia para contestar preguntas?
2015
AbstractIn one experiment, we explored how high school students use hyperlink relevance cues while they navigate to answer questions from hypertexts. Current evidence has shown that students may navigate by either performing a deep semantic analysis of the relationship between the question and the existing hyperlinks, or by matching words in the question to words in the hyperlink labels. We focused on how students combine both cues during navigation, and how comprehension skills relate to the use of such cues. Our study revealed that 14 year old students (N = 53) selected hyperlinks by relying to a similar degree on both word matching and semantic overlap. Furthermore, when there was a conf…
Machine learning risk prediction of mortality for patients undergoing surgery with perioperative SARS-CoV-2: the COVIDSurg mortality score
2021
The British journal of surgery 108(11), 1274-1292 (2021). doi:10.1093/bjs/znab183
Les raisons de la double activité des médecins : le cas de l'Algérie
2014
L’objet de cet article est d’analyser la double activite des medecins en Algerie sous trois angles d’approche. Le premier mobilise les theories de l’offre de travail appliquees aux professionnels de sante confrontes a l’existence de deux secteurs, un prive, un public, dont bien souvent les niveaux de remuneration horaire different et ou les temps respectifs de travail peuvent en partie etre choisis. La complementarite entre les deux emplois sous-tend dans une large mesure les strategies d’offre de travail des medecins. Le deuxieme se refere aux registres des motivations des medecins dans leur choix d’une activite privee complementaire. Le troisieme est relatif aux strategies d’adressage des…
Do networks matter? Network involvement and policy learning in Nordic regions
2017
ABSTRACTThe capacities of regions to form networks are an important feature of regional cooperation. This article assesses why Nordic regions engage in network activities and what new organizational patterns of collaboration emerge. It draws on historical data from a 2006–2008 survey of elected regional politicians from the Nordic countries. The article argues that through this process, participation in cross-border networks matters for regional learning as measured by the policy-choices of regions.
A cultural heritage experience for visually impaired people
2020
Abstract In recent years, we have assisted to an impressive advance of computer vision algorithms, based on image processing and artificial intelligence. Among the many applications of computer vision, in this paper we investigate on the potential impact for enhancing the cultural and physical accessibility of cultural heritage sites. By using a common smartphone as a mediation instrument with the environment, we demonstrate how convolutional networks can be trained for recognizing monuments in the surroundings of the users, thus enabling the possibility of accessing contents associated to the monument itself, or new forms of fruition for visually impaired people. Moreover, computer vision …