An unsupervised approach to disjointness learning based on terminological cluster trees

Semantic Web ◽  
2020 ◽  
pp. 1-25
Author(s):  
Giuseppe Rizzo ◽  
Claudia d’Amato ◽  
Nicola Fanizzi
Keyword(s):  
Empirical Evaluation ◽  
Divide And Conquer ◽  
Distance Measures ◽  
Alternative Methods ◽  
Statistical Correlations ◽  
Modeling Process ◽  
Web Of Data ◽  
Unsupervised Approach ◽  
Refinement Operator

In the context of the Semantic Web regarded as a Web of Data, research efforts have been devoted to improving the quality of the ontologies that are used as vocabularies to enable complex services based on automated reasoning. From various surveys it emerges that many domains would require better ontologies that include non-negligible constraints for properly conveying the intended semantics. In this respect, disjointness axioms are representative of this general problem: these axioms are essential for making the negative knowledge about the domain of interest explicit yet they are often overlooked during the modeling process (thus affecting the efficacy of the reasoning services). To tackle this problem, automated methods for discovering these axioms can be used as a tool for supporting knowledge engineers in modeling new ontologies or evolving existing ones. The current solutions, either based on statistical correlations or relying on external corpora, often do not fully exploit the terminology. Stemming from this consideration, we have been investigating on alternative methods to elicit disjointness axioms from existing ontologies based on the induction of terminological cluster trees, which are logic trees in which each node stands for a cluster of individuals which emerges as a sub-concept. The growth of such trees relies on a divide-and-conquer procedure that assigns, for the cluster representing the root node, one of the concept descriptions generated via a refinement operator and selected according to a heuristic based on the minimization of the risk of overlap between the candidate sub-clusters (quantified in terms of the distance between two prototypical individuals). Preliminary works have showed some shortcomings that are tackled in this paper. To tackle the task of disjointness axioms discovery we have extended the terminological cluster tree induction framework with various contributions: 1) the adoption of different distance measures for clustering the individuals of a knowledge base; 2) the adoption of different heuristics for selecting the most promising concept descriptions; 3) a modified version of the refinement operator to prevent the introduction of inconsistency during the elicitation of the new axioms. A wide empirical evaluation showed the feasibility of the proposed extensions and the improvement with respect to alternative approaches.

scholarly journals CSO Classifier 3.0: a scalable unsupervised method for classifying documents in terms of research topics

2021 ◽  
Author(s):  
Angelo Salatino ◽  
Francesco Osborne ◽  
Enrico Motta
Keyword(s):  
Computer Science ◽  
Digital Libraries ◽  
Gold Standard ◽  
Research Trends ◽  
Alternative Methods ◽  
Relevant Research ◽  
Research Topics ◽  
Research Papers ◽  
Research Areas ◽  
Unsupervised Approach

AbstractClassifying scientific articles, patents, and other documents according to the relevant research topics is an important task, which enables a variety of functionalities, such as categorising documents in digital libraries, monitoring and predicting research trends, and recommending papers relevant to one or more topics. In this paper, we present the latest version of the CSO Classifier (v3.0), an unsupervised approach for automatically classifying research papers according to the Computer Science Ontology (CSO), a comprehensive taxonomy of research areas in the field of Computer Science. The CSO Classifier takes as input the textual components of a research paper (usually title, abstract, and keywords) and returns a set of research topics drawn from the ontology. This new version includes a new component for discarding outlier topics and offers improved scalability. We evaluated the CSO Classifier on a gold standard of manually annotated articles, demonstrating a significant improvement over alternative methods. We also present an overview of applications adopting the CSO Classifier and describe how it can be adapted to other fields.

scholarly journals Home Mechanical Ventilation: A Patient’s Perspective Survey Study

2021 ◽  
Vol 18 (8) ◽  
pp. 4048
Author(s):  
Magdalena Kwiatosz-Muc ◽  
Bożena Kopacz
Keyword(s):  
Health Care ◽  
Mechanical Ventilation ◽  
Alternative Methods ◽  
Survey Study ◽  
Home Mechanical Ventilation ◽  
Patient’S Satisfaction ◽  
Satisfaction Index ◽  
Number Of Patients ◽  
The Difference

Background: An increasing number of patients included in home mechanical ventilation (HMV) care has been under observation for many years. The study aimed to assess the patients opinion concerning the expected and perceived quality of care in an HMV system and a patient’s satisfaction with care. Methods: In 2017, patients treated with HMV were surveyed in Poland with the modified SERVQUAL questionnaire. Results: One hundred correctly completed surveys were analyzed. Patient Satisfaction Index was high. In every examined area, the expectations were statistically significant larger than the perception of the services. The biggest gap was in the tangibility dimension and the smallest gap was in the empathy dimension. Perceived respect and understanding for a patient’s needs are close to the expectations. Conclusions: The level of satisfaction with health care among patients treated with HMV in majority of investigated components is high. Moreover, the difference between perceived and expected quality of health care in the HMV system was relatively small in the opinion of the patients themselves. Further investigations with alternative methods are needed.

scholarly journals Hydrometeor classification through statistical clustering of polarimetric radar measurements: a semi-supervised approach

2016 ◽  
Vol 9 (9) ◽  
pp. 4425-4445 ◽  
Author(s):  
Nikola Besic ◽  
Jordi Figueras i Ventura ◽  
Jacopo Grazioli ◽  
Marco Gabella ◽  
Urs Germann ◽  
...  
Keyword(s):  
Polarimetric Radar ◽  
Statistical Framework ◽  
X Band ◽  
Different Types ◽  
Unsupervised Approach ◽  
Radar Measurements ◽  
Supervised Classification Methods ◽  
Operational Potential ◽  
Statistical Clustering

Abstract. Polarimetric radar-based hydrometeor classification is the procedure of identifying different types of hydrometeors by exploiting polarimetric radar observations. The main drawback of the existing supervised classification methods, mostly based on fuzzy logic, is a significant dependency on a presumed electromagnetic behaviour of different hydrometeor types. Namely, the results of the classification largely rely upon the quality of scattering simulations. When it comes to the unsupervised approach, it lacks the constraints related to the hydrometeor microphysics. The idea of the proposed method is to compensate for these drawbacks by combining the two approaches in a way that microphysical hypotheses can, to a degree, adjust the content of the classes obtained statistically from the observations. This is done by means of an iterative approach, performed offline, which, in a statistical framework, examines clustered representative polarimetric observations by comparing them to the presumed polarimetric properties of each hydrometeor class. Aside from comparing, a routine alters the content of clusters by encouraging further statistical clustering in case of non-identification. By merging all identified clusters, the multi-dimensional polarimetric signatures of various hydrometeor types are obtained for each of the studied representative datasets, i.e. for each radar system of interest. These are depicted by sets of centroids which are then employed in operational labelling of different hydrometeors. The method has been applied on three C-band datasets, each acquired by different operational radar from the MeteoSwiss Rad4Alp network, as well as on two X-band datasets acquired by two research mobile radars. The results are discussed through a comparative analysis which includes a corresponding supervised and unsupervised approach, emphasising the operational potential of the proposed method.

scholarly journals Combining experimental and simulation data of molecular processes via augmented Markov models

2017 ◽  
Vol 114 (31) ◽  
pp. 8265-8270 ◽  
Author(s):  
Simon Olsson ◽  
Hao Wu ◽  
Fabian Paul ◽  
Cecilia Clementi ◽  
Frank Noé
Keyword(s):  
Force Field ◽  
Structural Changes ◽  
Markov Models ◽  
Force Fields ◽  
Divide And Conquer ◽  
Simulation Data ◽  
Wide Range ◽  
Simulation And Experiment ◽  
Kinetics Of

Accurate mechanistic description of structural changes in biomolecules is an increasingly important topic in structural and chemical biology. Markov models have emerged as a powerful way to approximate the molecular kinetics of large biomolecules while keeping full structural resolution in a divide-and-conquer fashion. However, the accuracy of these models is limited by that of the force fields used to generate the underlying molecular dynamics (MD) simulation data. Whereas the quality of classical MD force fields has improved significantly in recent years, remaining errors in the Boltzmann weights are still on the order of a few kT, which may lead to significant discrepancies when comparing to experimentally measured rates or state populations. Here we take the view that simulations using a sufficiently good force-field sample conformations that are valid but have inaccurate weights, yet these weights may be made accurate by incorporating experimental data a posteriori. To do so, we propose augmented Markov models (AMMs), an approach that combines concepts from probability theory and information theory to consistently treat systematic force-field error and statistical errors in simulation and experiment. Our results demonstrate that AMMs can reconcile conflicting results for protein mechanisms obtained by different force fields and correct for a wide range of stationary and dynamical observables even when only equilibrium measurements are incorporated into the estimation process. This approach constitutes a unique avenue to combine experiment and computation into integrative models of biomolecular structure and dynamics.

scholarly journals Mortality of insects and quality of maize grains in hermetic and non-hermetic storage

2016 ◽  
Vol 20 (5) ◽  
pp. 487-492 ◽  
Author(s):  
Priscila C. Viebrantz ◽  
Lauri L. Radunz ◽  
Rafael G. Dionello
Keyword(s):  
Storage System ◽  
Alternative Methods ◽  
Modified Atmosphere ◽  
Chemical Methods ◽  
Hermetic Storage ◽  
Insect Mortality ◽  
Polyethylene Bags ◽  
Maize Grain ◽  
Storage Units

ABSTRACT Due to the need to improve the quality and safety of foods, chemical methods used to control grain pests have been replaced by alternative methods. For example, modified atmosphere within the storage units has been used. Therefore, the objective was to evaluate maize grain quality and mortality of insects of the species Sitophilus zeamais and Tribolium castaneum in hermetic and non-hermetic environments for 50 days of storage. The hermetic units consisted of polyethylene "bags" with capacity for 60 kg. A cage with 20 adults of each species and 200 g of maize was placed inside each unit. The oxygen level was quantified every five days. Evaluations of insect mortality and survival occurred at 10, 20, 30, 40 and 50 days of storage. At 0, 30 and 50 days, density, moisture and fungal incidence analyses were conducted. The airtight system is efficient in the control of insects, with satisfactory mortality values for both species. Insects favor the development of fungi during the storage, regardless of the storage system.

A critical review of cardiac rehabilitation in a digital era

2021 ◽  
Vol 16 (8) ◽  
pp. 1-9
Author(s):  
Hazel Nikolov ◽  
Julia Hubbard
Keyword(s):  
Cardiac Rehabilitation ◽  
Cardiac Event ◽  
Social Economic ◽  
Alternative Methods ◽  
Face To Face ◽  
Digital Era ◽  
The Uk ◽  
Economic Constraints ◽  
Traditional Approaches

Cardiac rehabilitation improves the outcomes of individuals following a cardiac event; however, only 50% of those eligible for cardiac rehabilitation in the UK sign up to a traditional face-to-face programme. The principal causes cited for non-attendance include living in a rural area, work or career commitments, lack of choice in location, gender, ethnicity and social economic constraints, and dislike of group participation. Alternative methods of delivery could ensure greater participation in cardiac rehabilitation activities, particularly among women, who are underrepresented. Studies into digital cardiac rehabilitation reveal improved quality of life, dietary intake and increased physical activity all equal to or an improvement compared to traditional approaches. Embracing digital approaches to cardiac rehabilitation is now timely with COVID-19 requirements for social distancing.

scholarly journals Therapeutic effects of lignans in women in perimenopausal and postmenopausal periods (review of literature)

2021 ◽  
Vol 8 (1) ◽  
pp. 26-34
Author(s):  
Lyudmila A. Ozolinya ◽  
Valentina V. Litvinova
Keyword(s):  
Emotional Disorders ◽  
Alternative Methods ◽  
Therapeutic Effects ◽  
Female Population ◽  
Perimenopausal Women ◽  
Prevention And Treatment ◽  
Low Incidence ◽  
Positive Effect

Today, there is a tendency towards an increase of the number of the female population that has crossed the line of menopause, which makes it more urgent to improve the quality of life of women and to develop safe methods for the prevention and treatment of climacteric syndrome (CS), which is an integral medical, social and economic problems. In view of the presence of contraindications for use and defined risks of complications with the use of hormone menopausal therapy (HRT), it is necessary to develop alternative methods for the prevention and treatment of perimenopausal symptoms. This literary review of domestic and foreign sources demonstrates information about the role of the plant lignan 7-hydroxymatairezinol (7-HMR) in maintaining the physical and psychoemotional health of women in the period of peri- and postmenopause. As a result of the analysis of the therapeutic effects of the 7-HMR molecule, the ability to relieve the main symptoms of CS (neurovegetative presentations and emotional disorders), to improve the general state of health and metabolic profile of perimenopausal women was revealed. High safety and low incidence of side effects were noted, as well as a positive effect on the dynamics of body weight. The presence of a stable anti-inflammatory and antioxidant activity 7-HMR makes it possible to recommend this lignan to women in the climacteric period as an effective drug for the prevention of the formation of immune deficiency, which contributes to the development of oncological and autoimmune diseases. The proven antitumor activity confirms the promise of using the 7-HMR for the implementation of oncopreventive measures in women of peri- and postmenopausal age.

Regional blockade for prolonged anesthesia in enucleation and evisceration

Reflection ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 47-55
Author(s):  
I.G. Oleshchenko ◽  
◽  
О.P. Mishchenko ◽  
М.А. Gasparyan ◽  
◽  
...  
Keyword(s):  
Postoperative Period ◽  
Choroidal Melanoma ◽  
Opioid Analgesics ◽  
Early Postoperative Period ◽  
Alternative Methods ◽  
Combined Method ◽  
Retrobulbar Anesthesia ◽  
Pterygopalatine Ganglion ◽  
Systemic Side Effects

Regional anesthesia is widely used in ophthalmology both as an independent method and in combination. Retrobulbar anesthesia has risks of complications and is undesirable in the surgical treatment of choroidal melanoma due to the risk of metastasis of tumor cells when it is performed. Therefore, it is necessary to search for alternative methods of regional blockades in order to create prolonged anesthesia. Purpose. To develop and evaluate the clinical efficacy of pterygopalatine blockade as a component of combined method of anesthesia for evisceration or enucleation of the eyeball. Methods. A comparative analysis of the effectiveness of intraoperative anesthesia and the course of postoperative period was carried out in patients of two clinical groups formed depending on the method of anesthesia. Results. Intraoperative monitoring of hemodynamics in the groups did not differ. The nature of pain in the patients of the compared groups in the postoperative period had significant differences in presence and intensity of pain on the scale of verbal sensations. Discussion. Use of pterygopalatine blockade with levobupivacaine in combination with dexamethasone as an adjuvant allows getting a prolonged analgesic, anti-inflammatory and decongestant effect. This makes it possible to avoid the use of opioid analgesics in the early postoperative period, that is, to avoid such systemic side effects as nausea, dizziness, and in rare cases vomiting, which generally improves the quality of the postoperative period. Conclusions. Use of pterygopalatine ganglion blockade with local prolonged-acting anesthetic levobupivacaine and dexamethasone as an adjuvant based on inhaled anesthesia with sevoflurane provides safe and effective anesthesia in patients with evisceration or enucleation of the eyeball, both in the intra- and postoperative period. Key words: enucleation; evisceration; pterygopalatine blockade; dexamethasone.

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