Medically Relevant Criteria used in EEG Compression for Improved Post-Compression Seizure Detection

Biomedical signals aid in the diagnosis of different disorders and abnormalities. When targeting lossy compression of such signals, the medically relevant information that lies within the data should maintain its accuracy and thus its reliability. In fact, signal models that are inspired by the bio-physical properties of the signals at hand allow for a compression that preserves more naturally the clinically significant features of these signals. In this paper, we illustrate this through the example of EEG signals; more specifically, we analyze three specific lossy EEG compression schemes. These schemes are based on signal models that have different degrees of reliance on signal production and physiological characteristics of EEG. The resilience of these schemes is illustrated through the performance of seizure detection post compression.Comment: This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

Detection of Sentiment Provoking Events in Social Media

Social media has become one of the main sources of news and events due to its ability to disseminate and propagate information very fast and to a large population. Social media platforms are widely accessible to the population making it difficult to extract relevant information from the huge amount of posted data. In our study, we propose an algorithm that automatically detects events using strong sentiment classification and appropriate clustering techniques. We focus our study on a specific type of events that triggers strong sentiment among the public. Results show that the suggested methodology is able to identify important events, such as a mass shooting and plane crash, using a generalized and simple approach

Three essays on intellectual capital in Mexican SMEs

Cette thèse s’intéresse à la mesure du capital intellectuel (CI) ainsi que son impact sur les avantages compétitifs de petites et moyennes entreprises (PME) au Mexique. La principale question de recherche est : Comment le capital intellectuel devrait-il être mesuré et quel est son impact sur l’avantage compétitif des PME au Mexique? Afin de répondre à la question de la recherche, le premier article offre une perspective méthodologique du CI. Dans cette revue, les limites des méthodes quantitatives utilisées lors de l’étude du CI sont soulevées. L’utilisation de la modélisation par équations structurelles est discutée et privilégiée. Dans le deuxième article, un modèle de mesure adapté aux réalités des PME mexicaines est proposé. Les résultats suggèrent que, le capital humain et le capital organisationnel sont cohérents avec les études précédentes portant sur le CI dans les PME. Par contre, le capital externe présente des caractéristiques uniques au contexte du Mexique. De plus, malgré les disparités socio-économiques entre les différentes régions au Mexique, suite à une analyse comparative, il est démontré que la vision des gestionnaires ne semble pas différer en termes de CI. Finalement, malgré la multitude de programmes gouvernementaux à la fois aux niveaux national et local, très peu de PME semblent en récolter les bénéfices. Le troisième article tient compte de la théorie basée sur les ressources et la théorie des capacités dynamiques afin d’examiner le CI dans les PME mexicaines ainsi que leur relation avec l’avantage compétitif. Une typologie est proposée et les PME examinées y sont catégorisées en conséquence. Les résultats suggèrent que les PME avec des capacités dynamiques ont institué des processus à l’interne afin de répondre plus rapidement au changement, leur permettant ainsi de gérer les opportunités et les menaces. De plus, elles prennent plus de risques que les PME moins dynamiques lorsqu’il s’agit de saisir des opportunités et de les transformer en avantages compétitifs. De tels processus sont intrinsèques aux PME dites dynamiques parce qu’ils deviennent partie de la culture organisationnelle.The objective of this thesis is to measure intellectual capital (IC) and its impact on the competitive advantage of small and medium enterprises (SMEs) in Mexico. The main research question is: How should intellectual capital be measured and what is its impact on the competitive advantage of SMEs in Mexico? To answer the research question, the first essay offers a methodological perspective of IC. In this review, the limitations of quantitative methods used in the study of IC are noted. Subsequently, the use of structural equation modeling is discussed and promoted. In the second essay, a measurement model adapted to the realities of Mexican SMEs is proposed. The results suggest that human capital and organizational capital are consistent with previous studies of IC in SMEs. As for external capital, it presents some characteristics unique to the Mexican context. Moreover, despite the socio-economic disparities across regions in Mexico, a comparative analysis shows that the vision of managers does not seem to differ in terms of IC. Finally, despite the multitude of governmental programs at both national and local levels, very few SMEs seem to be reaping their benefits. The third essay takes into account the resource-based and the dynamic-capabilities views to examine IC in Mexican SMEs and its relation to competitive advantage. A typology is proposed and the examined SMEs are categorized accordingly. The results suggest that SMEs with dynamic capabilities have instituted processes within their organizations to respond more rapidly to change, allowing them to manage opportunities and threats. Moreover, they are willing to take more risks than their counterparts, who are characterized by less dynamism in seizing opportunities and transforming them into competitive advantages. Such processes are intrinsic to SMEs because they become part of the culture of organizations

A Hybrid Active Filter Using the Backstepping Controller for Harmonic Current Compensation

This document presents a new hybrid combination of filters using passive and active elements because of the generalization in the use of non-linear loads that generate harmonics directly affecting the symmetry of energy transmission systems that influence the functioning of the electricity grid and, consequently, the deterioration of power quality. In this context, active power filters represent one of the best solutions for improving power quality and compensating harmonic currents to get a symmetrical waveform. In addition, given the importance and occupation of the transmission network, it is necessary to control the stability of the system. Traditionally, passive filters were used to improve energy quality, but they have endured problems such as resonance, fixed remuneration, etc. In order to mitigate these problems, a hybrid HAPF active power filter is proposed combining a parallel active filter and a passive filter controlled by a backstepping algorithm strategy. This control strategy is compared with two other methods, namely the classical PI control, and the fuzzy logic control in order to verify the effectiveness and the level of symmetry of the backstepping controller proposed for the HAPF. The proposed backstepping controller inspires the notion of stability in Lyapunov’s sense. This work is carried out to improve the performance of the HAPF by the backstepping command. It perfectly compensates the harmonics according to standards. The results of simulations performed under the Matlab/Simulink environment show the efficiency and robustness of the proposed backstepping controller applied on HAPF, compared to other control methods. The HAPF with the backstepping controller shows a significant decrease in the THD harmonic distortion rate

Fit evaluation of soft milled zirconia and CoCr by microcomputed tomography

Statement of problem. The absolute marginal fit of CAD-CAM presintered fixed partial dentures has been poorly documented. Purpose. The purpose of this in vitro study was to evaluate the marginal fit of presintered cobalt-chromium (Co-Cr) and zirconia 3-unit fixed partial dentures by using X-ray microcomputed tomography (mCT). Material and methods. A metal model was prepared from a typodont to receive fixed partial dentures (N=12). The maxillary first premolar and first molar were prepared with a circumferential 1.2-mm chamfer and 2-mm occlusal reduction. The dies were scanned and assigned to 1 of 2 groups to receive the prostheses made of presintered Co-Cr or presintered zirconia (n=6). Each framework was seated on its model without load application. The abutments were scanned by using mCT. A circle with 10 diameters, with a step of 18 degrees, was projected at the center of the obtained image. Absolute marginal discrepancy and marginal gap mean values were measured and overextended and underextended margins were determined. The data were analyzed by using the Levene t-test and ANOVA (a=.05). Results. No statistically significant difference was found in the marginal fit between the materials tested (P=.939). The mean values were 66 ±14 mm for Co-Cr and 61 ±12 mm for zirconia. The absolute marginal discrepancy mean value for the premolar was 69 ±12 mm and 41 ±9 mm for the molar (P Conclusions. Presintered alloys presented clinically acceptable adaptation with a predominance of marginal overextensions

Erectile dysfunction following pelvic fracture

A research report submitted to the Faculty of Health Sciences at the University of the Witwatersrand in partial fulfillment of the requirements for the qualifications of MMed (Urology) 2017Background: Erectile dysfunction is one of the most important sequelae of pelvic fractures and may be transient or permanent. It can range from weak erections to severe sexual dysfunctions. Importantly, erectile dysfunction is more prevalent when the pelvic fracture is associated with urethral injury. Methods: This was a retrospective study of patient records, with a prospective questionnaire arm for patients admitted to the hospitals with a pelvic fracture between 01/07/2011 to 30/04/2015. The electronic databases of the Orthopedic Department at Helen Joseph Hospital and the Male Sexual Dysfunction Clinic at Charlotte Maxeke Johannesburg Academic Hospital were accessed for patients' contact details, by using the name and hospital number of each patient. Each patient was contacted telephonically with an open speaker in a presence of a witness/translator. The information sheet was read to the patient before the telephonic consent was obtained. After consent was obtained, patients were asked to verbally complete the International Index of Erectile Function score questionnaire. Results A total of 53 patients participated in the study, of which (43.4%) reported erectile dysfunction. The majority of patients indicated a recovery of erectile function between 2 8 | P a g e to 8 months after the injury. Most were found to still suffer from other forms of sexual impairment like orgasmic dysfunction and sexual satisfaction. However, sexual desire seemed to be preserved. Patients with sexual dysfunction were more likely to have had a urethral injury as well as a more severe fracture. Conclusions In our sample of 53 patients almost half reported sexual dysfunction after a pelvic fracture. Importantly, patients with urethral damage and a severe pelvic fracture should be followed up, as the risk of sexual dysfunction is high in these particular patients.MT201

Unconventional aspects of electronic transport in delafossite oxides

The electronic transport properties of the delafossite oxides ABO$_2$ are usually understood in terms of two well separated entities, namely, the triangular A$^+$ and (BO$_2$)$^-$ layers. Here we review several cases among this extensive family of materials where the transport depends on the interlayer coupling and displays unconventional properties. We review the doped thermoelectrics based on CuRhO$_2$ and CuCrO$_2$, which show a high-temperature recovery of Fermi-liquid transport exponents, as well as the highly anisotropic metals PdCoO$_2$, PtCoO$_2$ and PdCrO$_2$ where the sheer simplicity of the Fermi surface leads to unconventional transport. We present some of the theoretical tools that have been used to investigate these transport properties and review what can and cannot be learned from the extensive set of electronic structure calculations that have been performed.Comment: 35 pages, 19 figure