Search Results (5)

Vague influence graphs (VIGs) are well articulated, useful and practical tools for managing the uncertainty preoccupied in all real-life difficulties where ambiguous facts, figures and explorations are explained. A VIG gives the information about the effect of a vertex on the edge. In this paper, we present the domination concept for VIG. Some issues and results of the domination in vague graphs (VGs) are also developed in VIGs. We defined some basic notions in the VIGs such as the walk, path, strength of $\mathcal{I}n$-pair , strong $\mathcal{I}n$-pair, $\mathcal{I}n$-cut vertex, $\mathcal{I}n$-cut pair (CP), complete VIG and strong pair domination number in VIG. Finally, an application of domination in illegal drug trade was introduced. Full article

This article proposes the application of a new mathematical model of spots for solving inverse problems using a learning method, which is similar to using deep learning. In general, the spots represent vague figures in abstract “information spaces” or crisp figures with a lack of information about their shapes. However, crisp figures are regarded as a special and limiting case of spots. A basic mathematical apparatus, based on L4 numbers, has been developed for the representation and processing of qualitative information of elementary spatial relations between spots. Moreover, we defined L4 vectors, L4 matrices, and mathematical operations on them. The developed apparatus can be used in Artificial Intelligence, in particular, for knowledge representation and for modeling qualitative reasoning and learning. Another application area is the solution of inverse problems by learning. For example, this can be applied to image reconstruction using ultrasound, X-ray, magnetic resonance, or radar scan data. The introduced apparatus was verified by solving problems of reconstruction of images, utilizing only qualitative data of its elementary relations with some scanning figures. This article also demonstrates the application of a spot-based inverse Radon algorithm for binary image reconstruction. In both cases, the spot-based algorithms have demonstrated an effective denoising property. Full article

The use of fuzzy partial differential equations has become an important tool in which uncertainty or vagueness exists to model real-life problems. In this article, two numerical techniques based on finite difference schemes that are the centered time center space and implicit schemes to solve fuzzy wave equations were used. The core of the article is to formulate a new form of centered time center space and implicit schemes to obtain numerical solutions fuzzy wave equations in the double parametric fuzzy number approach. Convex normalized triangular fuzzy numbers are represented by fuzziness, based on a double parametric fuzzy number form. The properties of fuzzy set theory are used for the fuzzy analysis and formulation of the proposed numerical schemes followed by the new proof stability thermos under in the double parametric form of fuzzy numbers approach. The consistency and the convergence of the proposed scheme are discussed. Two test examples are carried out to illustrate the feasibility of the numerical schemes and the new results are displayed in the forms of tables and figures where the results show that the schemes have not only been effective for accuracy but also for reducing computational cost. Full article

Pheochromocytomas (PCC) and paragangliomas (PGL) may be difficult to diagnose because of vague and uncharacteristic symptoms and equivocal biochemical and radiological findings. This was a retrospective cohort study in 102 patients undergoing ¹¹C-hydroxy-ephedrine (¹¹C-HED)-PET/CT because of symptoms and/or biochemistry suspicious for PCC/PGL and/or with radiologically equivocal adrenal incidentalomas. Correlations utilized CT/MRI, clinical, biochemical, surgical, histopathological and follow-up data. ¹¹C-HED-PET/CT correctly identified 19 patients with PCC and six with PGL, missed one PCC, attained one false positive result (nodular hyperplasia) and correctly excluded PCC/PGL in 75 patients. Sensitivity, specificity, positive and negative predictive values of ¹¹C-HED-PET/CT for PCC/PGL diagnosis was 96%, 99%, 96% and 99%, respectively. In 41 patients who underwent surgical resection and for whom correlation to histopathology was available, the corresponding figures were 96%, 93%, 96% and 93%, respectively. Tumor ¹¹C-HED-uptake measurements (standardized uptake value, tumor-to-normal-adrenal ratio) were unrelated to symptoms of catecholamine excess (p > 0.05) and to systolic blood pressure (p > 0.05). In PCC/PGL patients, norepinephrine and systolic blood pressure increased in parallel (R² = 0.22, p = 0.016). ¹¹C-HED-PET/CT was found to be an accurate tool to diagnose and rule out PCC/PGL in complex clinical scenarios and for the characterization of equivocal adrenal incidentalomas. PET measurements of tumor ¹¹C-HED uptake were not helpful for tumor characterization. Full article

Signal segmentation is a crucial stage in the activity recognition process; however, this has been rarely and vaguely characterized so far. Windowing approaches are normally used for segmentation, but no clear consensus exists on which window size should be preferably employed. In fact, most designs normally rely on figures used in previous works, but with no strict studies that support them. Intuitively, decreasing the window size allows for a faster activity detection, as well as reduced resources and energy needs. On the contrary, large data windows are normally considered for the recognition of complex activities. In this work, we present an extensive study to fairly characterize the windowing procedure, to determine its impact within the activity recognition process and to help clarify some of the habitual assumptions made during the recognition system design. To that end, some of the most widely used activity recognition procedures are evaluated for a wide range of window sizes and activities. From the evaluation, the interval 1–2 s proves to provide the best trade-off between recognition speed and accuracy. The study, specifically intended for on-body activity recognition systems, further provides designers with a set of guidelines devised to facilitate the system definition and configuration according to the particular application requirements and target activities. Full article