Coverage Improvement In Wireless Sensor Networks Based On Fuzzy-Logic And Genetic Algorithm

Wireless sensor networks have been widely considered as one of the most important 21th century technologies and are used in so many applications such as environmental monitoring, security and surveillance. Wireless sensor networks are used when it is not possible or convenient to supply signaling or power supply wires to a wireless sensor node. The wireless sensor node must be battery powered.Coverage and network lifetime are major problems in WSNs so in order to address this difficulty we propose a combinational method consists of fuzzy-logic and genetic algorithms. The proposed scheme detects the coverage holes in the network and selects the most appropriate hole's neighbor to move towards the blank area and compensate the coverage loss with fuzzy-logic contribution and above node new coordinate is determined by genetic algorithm. As fuzzy-logic will be so effective if more than one factor influence on decision making and also genetic algorithms perform well in dynamic problems so our proposed solution results in fast, optimized and reliable outpu

Fuzzy Sliding Mode Control for Tracking the Optimal profile of Train Speed in the Presence of Uncertainty

Considering that the traction system is main factor of energy consumption in the train, and amount of force required for moving the train is directly related to its speed, therefore, the optimal profile selection for the speed of the train movement, in the path between the stations and the design of the controller for accurate tracing The optimal profile of the train speed, can be a determinant of the amount of energy consumed. Control of a train includes the non-linear, uncertainty and external disturbances terms that should be considered in the design of control rules. In this thesis, we present a control strategy for tracking optimal profile of train speed, based on the fuzzy sliding mode control (FSMC). The main motive of use the Sliding Mode Control (SMC), in non-linear systems, its resistance to parametric uncertainties, unmodeled dynamics, external disturbances and as well as the simplicity of its design. However, the occurrence of chattering phenomenon is the most important limiting factors the use of this control method. In this thesis to remove the chattering, fuzzy control is used to estimate the reaching control signal and the stability of the entire system is also guaranteed on the basis of the Lyapunov stability theorem Numerical simulations using the nonlinear dynamics model of the train, despite the uncertainty and disturbance, and comparing it with the conventional SMC, show the effectiveness of the FSMC method in tracing the optimal train speed profile

The role of Metacognition on effect of Working Memory Capacity on students' mathematical problem solving

The main objective of this study was to investigate the effects of Working Memory Capacity (WMC) on students' mathematical problem solving while considering different psychological factors. A sample of 256 high school girls students from Tehran (17-18 years old) were tested on (a) Metacognitive Awareness Inventory (MAI), (b) Mathematics Attention Test (MAT), (c) Mathematics Anxiety Rating Scale (MARS), (d) Digit Span Backward Test (DBT), and (e) a Mathematics Exam. Data of the present study were analyzed by descriptive and inferential statistics by T-test and Spearman correlation with the Statistical Package for the Social Sciences (SPSS). Results obtained indicate that metacognition had distinctive and challenging variable than other factors in use of WMC in mathematical problem solving. In other words, the correlation superiority between WMC and mathematical performance was found in group of high metacognition. Moreover, in each group of low/high metacognition, low/high math attention, and low/high math anxiety, the students with high WMC showed better mathematical performance than low WMC ones. The findings of the study are suitable for researchers who interested how different factors influence students’ mathematical problems solving.El principal objetivo de este estudio era investigar los efectos de la capacidad de memoria en el Trabajo (CMT) en los estudiantes, y la forma de resolver los ejercicios matemáticos planteados, mientras se consideraban diferentes factores psicológicos. En una muestra de 256 estudiantes mujeres entre los desde Teherán 17 y 18 años fueron evaluadas en a) Inventario conciencia meta cognitiva (ICM), (b) Prueba de atención Matemáticas (PAM), (c) Escala de ansiedad ante mas matemáticas (EAAM), (d) Prueba “Digit Span Backward”, y (e) un examen de Matemáticas. Los datos del presente estudio se analizaron mediante estadística descriptiva e inferencial de T-test y correlación de Spearman con el Paquete Estadístico para las Ciencias Sociales (SPSS). Los resultados indicaron que la meta cognición tiene distintivos y distintas variables desafiantes que otros factores usados en el WMC en la resolución de problemas matemáticos. En otras palabras, la superioridad correlación entre WMC y el rendimiento matemático se encontró en el grupo de alta metacognición. Además, en cada grupo de baja/ alta metacognición, atención alta/ baja de matemáticas, y bajo altos niveles de ansiedad/ matemáticas, los estudiantes con alta WMC mostraron mejor rendimiento matemático de los bajos de WMC. Los resultados del estudio son adecuados para los investigadores que estén interesados en los diferentes factores que influyen en los problemas matemáticos que los estudiantes resuelven

Ross operation in a neuro-cardio-facial-cutaneous syndrome patient

Congenital heart diseases are a major part of Costello and cardio-facio-cutaneous syndromes. Subaortic stenosis was reported rarely and Ross operation never in these syndromes

A study on the relationship between students’ cognitive style and Mathematical word and procedural problem solving while controlling for students’ intelligent quotient and math anxiety

The main purpose of the study is to investigate whether field dependency could predict students‟ mathematical problem solving in word and procedural mathematical problems and to explore whether this association remains significant when students‟ Mathematics anxiety and intelligent quotient (IQ) is controlled. So, we used data of 100 samples of guidance school girls and inferential statistical analysis (ANOVA and ANCOVA) for investigating the hypothesis of the study. Obtained results indicated that there were significant differences in students‟ mathematical performance in word and procedural problems by the groups of field dependency. Moreover, this difference is still significant when IQ and Mathematics anxiety as covariate variables were considered. However, the amount of omega square for ANCOVA analysis decreased when covariate variables inserted to the model. Findings of this study are suitable for researchers in field of psychology of learning Mathematics and who interested in how cognitive style affect students‟ performance in particular Mathematics.El principal objetivo de este estudio es investigar si la dependencia en el área puede predecir la forma en que los estudiantes resuelven los problemas matemáticos en escritos o procedimientos matemáticos y explorar si esta asociación se mantiene cuando la ansiedad matemática o coeficiente intelectual (IQ) es controlado. Por consiguiente, se usó una muestra de 100 niñas de escuela y análisis estadístico inferencial (ANOVA y ANCOVA) para investigar la hipótesis del estudio. Los resultados obtenidos indicaron que hubo sustanciales diferencias en los estudiantes y el desempeño matemático obtenido en palabras y procedimiento en la ejecución de los problemas por los grupos o área de dependencia. Sin embargo, esta diferencia es aún más significativa cuando el coeficiente intelectual (IQ) y la ansiedad matemática como covariable y variables fueron considerados. Sin embargo la cantidad de Omega Cuadrada para el análisis ANCOVA decreció cuando las covariables fueron insertadas en el modelo. Los hallazgos de este estudio son adecuados para los investigadores en el campo de la psicología del aprendizaje de las matemáticas y, en particular, cómo el estilo cognitivo afecta al desempeño de los estudiantes en Matemáticas

Ross operation in a neuro-cardio-facial-cutaneous syndrome patient

Congenital heart diseases are a major part of Costello and cardio-facio-cutaneous syndromes. Subaortic stenosis was reported rarely and Ross operation never in these syndromes. We reported a girl patient whose manifestations were consistent with these syndromes. Distinction between these syndromes was not possible as genetic testing was not carried out. She developed severe neoaortic regurgitation 2.5 years after the Ross operation and died due to the complications of aortic valve replacement. Ross operation may be an unsuitable option in these syndromes due to the possibility of subtle pulmonic valve pathology

Relationship between Blood Transfusion and Increased Risk of Atrial Fibrillation after Coronary Artery Bypass Graft Surgery

Background: New-onset atrial fibrillation (AF) after cardiac surgery contributes to increased morbidity, hospital length of stay, and resource utilization. Although many aspects of AF after cardiac surgery have already been elucidated, the mechanism by which cardiac surgery predisposes patients to AF has hitherto remained unknown. Recent evidence supports the notion that blood transfusion enhances the inflammatory response, thereby increasing the incidence of post-operative AF.Methods: This retrospective study was conducted on 2095 patients who underwent coronary artery bypass grafting (CABG) alone or accompanied by valve surgery between January 2005 and July 2007. Variables associated with the development of new-onset AF were identified using logistic regression. Results: Intensive care unit blood transfusion increased the risk of AF (odds ratio per unit transfused, 1.16; 95% confidence limits, 1.14, 1.24; P<0.001). Blood transfusion was performed in 487 patients and was associated with a significant increase in new-onset of AF (45.9% vs. 37.9%; P<0.01). Conclusion: Homologous blood transfusion can increase the incidence of new-onset AF after CABG. This factor should be considered in identifying patients who might benefit from prophylaxis in order to prevent this common post-operative complication and the adverse consequences thereof

Correlation between echocardiographic estimation of right atrial pressure and invasive measurement of central venous pressure in postoperative pediatric patients with congenital heart disease: a prospective observational study

Abstract Background Right atrial pressure plays a critical role as a hemodynamic parameter in diagnosing pulmonary hypertension and other cardiac diseases, as well as guiding the treatment and prognosis of various cardiac disorders. If there is no obstruction between the inferior or superior vena cava (SVC) as central veins and the right atrium, the pressures in these veins could be considered equal to the right atrial pressure. This study aimed to examine the correlation between echocardiographic methods for estimating right atrial pressure and invasive measurements of central venous pressure (CVPi) in infants and children with congenital heart disease during the 48 h after cardiac surgery and to establish regression equations for echocardiographic estimation of central venous pressure (CVPe). Results We prospectively enrolled 43 infants and children, ranging in age from 6 months to 16 years, including 20 males and 23 females. We found a significant correlation between CVPi and the ratio of the maximal diameter of IVC to the maximal diameter of the descending aorta ratio (IVCmax/DAOmax) (r = 0.529, P < 0.001), SVCS/D velocity ratio (SVCS/D) (r = 0.462, P = 0.006), right atrial vertical diameter (RAVD) (r = 0.409, P = 0.01), area (r = 0.384, P = 0.014), and tricuspid valve A wave acceleration rate (TVAAR) (r = 0.315, P = 0.048). Multiple regression analysis yielded an equation for estimating central venous pressure using four parameters related to the IVC, SVC, tricuspid valve, and right atrium. The equation is as follows: estimated CVP = 4.36 + (2.35 × IVCmax/DAOmax) + (1.06 × SVCS/D) +  (0.059 × RAVD) + (0.001 × TVAAR). This equation is strongly correlated with CVPi (Pearson r = 0.698, P = 0.002). Conclusions The estimation of central venous pressure through a multi-parametric equation that included the ratio of the maximal diameter of the inferior vena cava to the maximal diameter of the descending aorta, the ratio of S to D velocity of the superior vena cava, the vertical diameter of the right atrium, and the acceleration rate of the A wave of the tricuspid valve demonstrated a robust correlation with invasively measured central venous pressure. To assess the accuracy of predicted pressures by this equation, further investigations are required to apply this innovative multi-parametric formula to a prospective population of pediatric patients with congenital heart disease

Postoperative Mortality and Morbidity in Elderly Patients Undergoing Coronary Artery Bypass Graft Surgery

Background: Elderly patients (>75 years) have constituted the fastest growing portion of the coronary artery bypass grafting (CABG) patient population over the last two decades. Of the goals that surgical care for the elderly pursues, cure may be an unfeasible one; nevertheless, palliation and comfort warrant sufficient importance. The present study sought to examine the postoperative course and events in elderly patients undergoing CABG with or without other procedures and to compare the results with those in younger patients. Methods: Demographic, mortality, morbidity, and resource utilization data were collected from the records of the patients undergoing CABG between January 2005 and July 2007 in Imam Khomeini Medical Center, Tehran, Iran. Results: The mean time to extubation was 9.3 and 6.3 hours in the elderly and non-elderly patients, respectively (p<0.01). Blood transfusion was required in 87.8% of the elderly compared to 58.5% of the non-elderly subjects (p<0.01). The mean Intensive Care Unit stay was 2.1 days for the elderly and 1.4 days for the non-elderly patients (p<0.001). In-hospital mortality was 9% for the elderly patients vs. 2.8% for the younger group (p<0.001). Conclusion: The elderly patients undergoing CABG had a significantly higher morbidity rate, with an increased incidence of postoperative renal failure, neurological complications, and in-hospital mortality