130,690 research outputs found
Effect of Blade Design and Control Strategies on Levelized Cost of Energy of Tidal Stream Turbines
No full textA fuzzy approach to 2-D shape recognition
No full textThis paper describes a method for fuzzy classification and recognition of two-dimensional (2-D) shapes, such as handwritten characters, image contours, etc. A fuzzy model is derived for each considered shape from a fuzzy description of a set of instances of this shape. A fuzzy description of a shape instance, in its turn, exploits appropriate fuzzy partitions of the two dimensions of the shape. These fuzzy partitions allow us to identify, and automatically associate an importance degree with, the relevant shape zones for classification and recognition purposes.
Two significant applications of the method are described, namely, recognition of olfactory signals and recognition of isolated, handwritten characters. In the former case, results are shown concerning the recognition of three different types of waste waters, collected in three different dilutions. In the latter case, results are shown concerning the application of the method to a NIST database, containing the segmented handprinted characters of 500 writers
Direct and Indirect Involvement of Companies in the Development of Business and Human Rights Law: Insights from Practice
No full text1. Introduction - 2. 'Direct' Participation in 'Indirect' Law-making - 2.1 The Impact of Voluntary Regulation on Business and Human Rights Law - 2.2. The Case of the International Code of Conduct for Private Security Services Providers - 2. 'Indirect' Participation in 'Direct' Law-making - 3.1 Institutionalized Forms of Participation - 3.2 Extra-institutional Forms of Participation - 4. (Three) Concluding Remark
Risk factors for mortality from pneumonia in children in low and middle income countries: systematic review (protocol and preliminary results).
No full textBackground
Pneumonia is the most common cause of mortality in children under five years of age.
Aims
To systematically review the evidence on the risk factors for death from pneumonia in children in low and middle income countries.
Methods
We will searched MEDLINE, EMBASE, LILACS, CINAHL, BIBLIOMAP, POPLINE, for published studies. For ongoing studies we will search the WHO Platform (ICTRP), MetaRegister of Controlled Trials (mRCT), Current Controlled Trials (CCT). We will contact a list researchers working in the field, technical bodies and academic institutions. We will include for evaluation the following types of risk factors: a) Biological; b) Related to the disease; c) Environmental; d) Socio-economical; e) Health Services factors. Two authors will assess study eligibility and methodological quality and extract and analyse data. Where appropriate, we will combined data in meta-analyses (random-effects model) and assess heterogeneity. Heterogeneity will be explored by subgroup analysis, and if appropriate, by meta-regression.
Results
We identified so far 58 studies, including 66,775 children, both in hospital and community setting. Preliminary results show that factors significantly related to mortality pertain to all five categories evaluated: a) Biological factors (age, birth-weight, malnutrition, co-morbidities such as HIV, sepsis, diarrhoea -with some heterogeneity among studies, anaemia, rickets); b) Factors related to the disease (severity of pneumonia, hypoxia, disease duration, disease extension, bacterial disease); c) Environmental factors (indoor pollution); d) Socio-economical factors (maternal education); e) Health Services factors (health-worker visit, previous treatment).
Conclusion
Final results of this work will be available for presentation at the meeting
A fuzzy hierarchical approach to odor classification
No full textA fuzzy logic-based system to classify olfactive signals is presented. The odor samples are obtained from an electronic nose that contains conducting polymer sensors with partially overlapping sensitivities to odors. The sensor responses are represented by means of the coefficients of their Fast Fourier Transform (FFT). A feature reduction method is applied to reduce the feature space dimension. Then, an unsupervised Fuzzy Divisive Hierarchical Clustering (FDHC) method is used to establish the optimal number of clusters in the data set as well as the optimal cluster structure. The output of FDHC is a binary hierarchy of fuzzy classes that are used to build a supervised fuzzy hierarchical classifier. At each level of the fuzzy hierarchy a separating hyperplane of the two corresponding fuzzy training classes is determined. The hyperplane identifies two crisp decision regions, which will be refined at the next level of the hierarchy. Zn this way, we obtain a hierarchy of regions, which defines a crisp decision tree. Each region is, therefore, related to a specific expected output of the system. Recognition of an unknown odor is accomplished by computing the FFT of the corresponding signal and using the decision tree to establish the region the odor belongs to. Two small-scale applications of the method yielded 100% classification accuracy on out-of-sample data
Time Evolution analysis of bearing faults
No full textThis paper proposes a study and a method for automatic detection and diagnosis of defects of rolling element bearings. We use classification techniques (QDC and neural networks) and classifier fusion. We exploit experimental data consisting of vibration signals represented in the frequency domain by means of the Fast Fourier Transform, registered by two accelerometers. We consider one defect, namely indentation on the roll, with three different severity levels, with the data related to the lowest severity level collected in four subsequent days. We achieve high classification accuracy in all the experiments, which aim, respectively, to identify the defects as soon as they appear, to identify the defects as time passes, to train the classifier on defects collected in the first day and test it on signals collected in the following days, and, finally, to analyze how a specific defect evolves over time. In particular, by analyzing how the vibration signals of a damaged bearing evolve over time, we observe that, as time passes, the signals representing the least severe damage get more similar to those related to the same defect but with a higher severity level. This study can be profitably used to define when bearing maintenance should be performed
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