22 research outputs found
A Comparison between Respiratory Factors in Patients with Vocal Nodule and Normal Controls
No full text• Background:Speech is the most important communication tool and is the smooth product of four systems: respiratory, phonatory, resonatory, and articulatory. Currently, a variety of voice disorder occurred because of life style and environmental pollutants. Vocal nodule is one of the most prevalent disorders in this category. Considering the point that the air required for vocal cords vibration is supplied by respiratory system and we repeatedly confront with inappropriate respiratory factors in patients with vocal nodules, this study was carried out to compare respiratory factors in patients with vocal nodule and normal controls.
• Materials and Methods:In this study, 14 patients with vocal nodule and 7 healthy subjects referred from a medical specialist were examined. Vital capacity, vital volume and tidal volume of patients and controls were measured by PCLX, LX-strobe and ST 1 dysphonia while making voice with high, normal and low frequencies. The data were analyzed using Fisher and Mann-Withny tests.
• Results:The results showed that there was significant difference between patients with vocal nodule and healthy controls on all measured factors. However, there was no relationship between family background and vocal nodule.
• Conclusion:Patients with vocal nodule do not seem to have problem with the volume of their lungs. Probably high tension in their respiratory muscles during speaking causes them not to be able to use the full capacity of their lungs and this creates a short of tidal volume and as a result, a problem in their phonatory system, i.e., vocal nodule. Because of small sample size, we need to be cautious in generalizing the results.
• Key words: Vocal nodule, respiratory factors, phonatory syste
محاسبه ی بازگشتی مدول کشسانی لایههای روسازی به روش ترکیبی دیفرانسیل کوادرچر و الگوریتم بهینهسازی جستجوی هارمونی
No full textThe evaluation of pavements being utilized using falling weight deflectometer (FWD) is one of the most important components of the pavement management system in many countries. The computation of pavement layer properties to estimate the remaining life of the pavement and also pavement maintenance has always been of interest to road pavement researchers and engineers. On the other hand, the back-calculation is widely used for the estimation of the pavement layer properties. In most back-calculation methods, the commercial software such as ABAQUS, ANSYS, etc., are used as numerical simulation engine. But it is difficult to integrate them with the optimization engine and consequently, they require the pre-generated artificial analytical data for search space. ubsequently, much computational time due to the large number of iterations is required. In this paper, the differential quadrature method (DQM) is employed to analyze the pavement. By combining this method with harmony search (HS) optimization algorithm, a computationally efficient model is developed for calculation of surface deflections so that it significantly reduces the overall computational time for back-calculation. As an application of the proposed hybrid differential quadrature method and harmony search (DQ-HS) optimization algorithm, a numerical example for back-calculation of elastic modulus of a three-layer pavement structures is presented. The results of this study with different populations show that this method can be used to calculate the elastic modulus of the layers in less than 20 iterations. To demonstrate the efficiency of the optimization algorithm for harmonic search and the convergence independence of optimal solutions, the problem with 10 populations and repetition of 20 is performed 10 times with a series of random numbers. The results indicate that the independence of the method of optimization from random values. Fast convergence, high precision and low computational cost are the advantages of this proposed method to estimate
unknown parameters of a multilayer structure, including pavement structure
An application of evolutionary optimization algorithms for determining concentration and velocity profiles in sheet flows and overlying layers
No full textThe particle swarm optimization (PSO) method and the genetic algorithm (GA) were used to derive formulas for determining the velocity and concentration profiles in sheet flows. Specifically, these evolutionary optimization algorithms were used in conjunction with experimental data to determine coefficients and identify parameters for preselected formulas. The objective function, defined as the sum-of-squared errors between observed and predicted values of sediment velocity and concentration, was minimized by adjusting the parameter values in the formulas. Two well-known empirical formulas were also applied to the same data. The bias, root mean square error and scatter index were used to evaluate the comparison between predictions and measurements. The results indicated that the errors based on the PSO and GA approaches to predicting sediment parameters were less than those of the existing empirical formulas. Overall, both evolutionary approaches provided formulas that were in good agreement with the experimental data, giving improved descriptions of the vertical distribution of velocity and sediment concentration in the sheet flow for practical purposes. These models also described well the behavior of the velocity and sediment concentration above the sheet flow layer; in contrast with most existing formulas that are applicable only to the sheet flow layer
Vascular NADH Oxidase Is Involved in Impaired Endothelium-Dependent Vasodilation in OLETF Rats, a Model of Type 2 Diabetes
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