A decentralized proportional-integral sliding mode tracking controller for a 2 D.O.F robot arm

Trajectory tracking with high accuracy is a very challenging topic in direct drive robot control. This is due to the nonlinearities and input couplings present in the dynamics of the arm. This paper deals with the tracking control of a class of direct-drive robot manipulators. A robust Proportional-Integral (PI) sliding mode control law is derived so that the robot trajectory tracks a desired trajectory as closely as possible despite the highly non-linear and coupled dynamics. The controller is designed using the decentralized approaches. Application to a two degree of freedom direct drive robot arm is considered

Simultaneous use of Individual and Joint Regularization Terms in Compressive Sensing: Joint Reconstruction of Multi-Channel Multi-Contrast MRI Acquisitions

Purpose: A time-efficient strategy to acquire high-quality multi-contrast images is to reconstruct undersampled data with joint regularization terms that leverage common information across contrasts. However, these terms can cause leakage of uncommon features among contrasts, compromising diagnostic utility. The goal of this study is to develop a compressive sensing method for multi-channel multi-contrast magnetic resonance imaging (MRI) that optimally utilizes shared information while preventing feature leakage. Theory: Joint regularization terms group sparsity and colour total variation are used to exploit common features across images while individual sparsity and total variation are also used to prevent leakage of distinct features across contrasts. The multi-channel multi-contrast reconstruction problem is solved via a fast algorithm based on Alternating Direction Method of Multipliers. Methods: The proposed method is compared against using only individual and only joint regularization terms in reconstruction. Comparisons were performed on single-channel simulated and multi-channel in-vivo datasets in terms of reconstruction quality and neuroradiologist reader scores. Results: The proposed method demonstrates rapid convergence and improved image quality for both simulated and in-vivo datasets. Furthermore, while reconstructions that solely use joint regularization terms are prone to leakage-of-features, the proposed method reliably avoids leakage via simultaneous use of joint and individual terms. Conclusion: The proposed compressive sensing method performs fast reconstruction of multi-channel multi-contrast MRI data with improved image quality. It offers reliability against feature leakage in joint reconstructions, thereby holding great promise for clinical use.Comment: 13 pages, 13 figures. Submitted for possible publicatio

A study of the climate of Egypt with special reference to agriculture

This thesis contains a study of the climate of Egypt with special reference to agriculture. It is organised in three main sections. The main body of the thesis, beginning with Chapter 3 (Temperatures in Egypt), deals with surface, earth and water temperatures in detail. Analysis of daily maximum temperatures at selected stations during the 15 year period (1960 - 1974) showed that spring is the period during which the frequency and severity of hot spells is greatest. Analysis of precipitation over Egypt showed that the rainy season in Egypt occurs between October and May and the maximum rainfall over the coastal Mediterranean region occurs in January, but in Middle and Upper Egypt this maximum occurs in October and May. Evaporation and evapotranspiration was estimated using the Penman equation and the Thornthwaite formula for selected stations in Egypt. These indicated that the evaporation and evapotranspiration values for each month are very high at Aswan, Kharga and Dakhla stations, in comparison to Alexandria and Tanta. The main weather features which are sufficient to specify what is called Khamsin weather have been analysed. These are excessively high surface temperatures and extremely low humidities, associated with the invasion of south and south-east winds which produce rising dust and duststorms. It is also seen that there are two types of Khamsin depressions. The first originates over the Atlantic and the second forms to the south of the Atlas mountains. Factor analysis techniques have been used to classify the climate of Egypt. The results showed that the climate of Egypt can basically be divided into two climatic zones. The first comprises the Mediterranean Coastal area, including the Delta. The second zone covers the rest of the country south of Cairo. Multiple regression equations have been used to explain the relationships between the crop yields and selected climatic variables. The results derived show that the multiple regression equations analysing climatic data have good predictive qualities in terms of annual yields

Exact implicit Solution of Nonlinear Heat Transfer in Rectangular Straight Fin Using Symmetry Reduction Methods

In this paper, the exact implicit solution of the second order nonlinear ordinary differential equation which governing heat transfer in rectangular fin is obtained using symmetry reduction methods. General relationship among the temperature at the fin tip, the temperature gradient at the fin base, the mode of heat transfer, and the fin parameters and ℰ is obtained. Some numerical examples are discussed and it is shown that the temperature of fin increases when approaching from the heat source. The relationship between the fin efficiency and the temperature of fin tip is obtained for any value of the mode of heat transfer . The relationship between the fin efficiency and both the parameter and ε the temperature gradient at the fin base is obtained. To our best knowledge, solutions obtained in this paper are new

Aerobic exercise modulates cytokine profile and sleep quality in elderly

Background: Sleep disturbance is a major problem for older adults which can be exacerbated by increased inflammation as aging is associated with increased circulating pro-inflammatory and lower anti-inflammatory cytokines. There is a need to develop alternative medicine techniques to help improve sleep quality in the elderly.Objective: To investigate the effects of aerobic exercise training on the sleep quality and inflammatory cytokines in elderly subjects.Material and methods: Forty previously sedentary elderly subjects participated in this study, their age ranged from 61- 67 years. All subjects were randomly assigned to supervised aerobic exercise intervention group (group A, n=25) or control group (group B, n=25). Polysomnographic recordings for sleep quality assessment, interleukin- 6 (IL-6), tumor necrosis factor- alpha (TNF-α) and interleukin-10 (IL-10) were measured before and after 6 months at the end of the study.Results: There was a significant increase in total sleep duration, sleep efficiency and sleep onset latency in group(A) after 6 months of aerobic exercise training, while, wake time after sleep onset and rapid eye movement (REM) latency significantly reduced after 6 months of aerobic training compared with values obtained prior to aerobic exercise training. Also, the mean values of TNF- α and IL-6 decreased significantly and the mean value of IL-10 significantly increased in group (A) after the aerobic exercise training, however the results of the control group were not significant. Moreover, there were significant differences between both groups at the end of the study.Conclusion: Exercise training can be considered as a non-pharmacological modality for modifying sleep quality and inflammation among elderly.Keywords: Sleep quality, inflammatory cytokines, aerobic exercise, aging

Information technology in the British and Irish undergraduate accounting degrees

Using an online questionnaire and a series of semi-structured interviews, this study seeks the perceptions ofaccounting educators and professional accounting bodies in the UK and Ireland on the status quo of technologicaldevelopments within accounting curricula and the factors influencing this status quo. Findings suggest a fairlywidespread view that technological developments represent an important area that should be covered acrossaccounting curricula, to expose changes in the marketplace and to enhance the employability of graduates.However, it is still a peripheral component in accounting curricula, with no clear agenda for change. Professionalaccounting bodies seem to play a hegemonic inhibiting role through accreditation requirements although otherinhibitors were reported such as lack of competent/interested staff and lack of time/space in already overloadedsyllabi

Impact of weight reduction on insulin resistance, adhesive molecules and adipokines dysregulation among obese type 2 diabetic patients

Background: Type 2 diabetes mellitus is usually related to vascular problems and is associated with impairment in endothelial function characterized by impaired endothelial-dependent vasodilation and increased platelet adhesion. There is limitation in clinical studies that have addressed the beneficial effects of weight reduction in modulating biomarkers of endothelial dysfunction and adipokines dysregulation for obesity associated with type 2 diabetes mellitus. Objective: This study was designed to detect the effects of weight loss on insulin resistance, adhesive molecules and adipokines dysregulation in obese type 2 diabetic patients. Methods: Eighty obese patients with type 2 diabetes mellitus, their age ranged from 35-55 years and their body mass index ranged from 31-37 kg/m2  were equally assigned into 2 groups:  the weight reduction group received aerobic exercises in addition to diet regimen, where the control group received medical treatment only for 12 weeks. Results: There was a 24.04%, 19.33%, 22.78% ,12.28%, 9.35%, 22.53% & 10.12 % reduction in mean values of Homeostasis Model Assessment-Insulin Resistance Index (HOMA-IR), Leptin, Adiponectin, Resistin, intercellular cell adhesion molecule -1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin & body mass index (BMI) respectively in addition to 26.20% & 24.58% increase in the mean values of adiponectin & the quantitative insulin-sensitivity check index (QUICKI) respectively in group (A) at the end of the study. The mean values of leptin, resistin, insulin, HOMA-IR, ICAM-1, VCAM-1, E-selectin & BMI were significantly decreased in addition to significant increase in the mean values of adiponectin & QUICKI in group (A) those that received aerobic exercise training in addition to diet regimen. While the results of group (B) those that received no treatment intervention were not significant. In addition, there were significant differences between mean levels of the investigated parameters in group (A) and group (B) after treatment (P<0.05).Conclusion: Within the limit of this study, 10% reduction in body mass index modulates insulin resistance, adhesive molecules and adipokines dysregulation among obese type 2 diabetic patients.Keywords: Type 2 Diabetes, obesity, adhesive molecules, adipokines, insulin resistance, weight reduction

Impact of weight reduction on selected immune system response among Hepatitis C virus Saudi patients

Background: Recently, about 2.35% of the world populations are estimated to be chronically infected with hepatitis C virus (HCV). Previous cohort studies indicated that obesity increases risk of hepatic steatosis and fibrosis in non-diabetic patients with chronic hepatitis C infection due to diminished response to anti-viral therapy and as a result obesity is considered as an important factor in the progression of chronic HCV. However, there is a strong association between BMI and the human immune system among HCV patients.Objective: This study aimed to examine effects of weight reduction program on selected immune parameters among HCV Saudi patients. Material and methods: One-hundred obese Saudi patients with chronic HCV infection participated in this study, their age ranged from 50- 58 years and their body mass index (BMI) ranged from 30-35 kg/m2. All Subjects were included in two groups: The first group received weight reduction program in the form of treadmill aerobic exercises in addition to diet control whereas, the second group received no therapeutic intervention. Parameters of CD3, CD4 and CD8 were quantified; Leukocyte, differential counts and BMI were measured before and after 3 months, at the end of the study. Results: The mean values of BMI, white blood cells, total neutrophil count, monocytes, CD3, CD4 and CD8 were significantly decreased in the training group as a result of weight loss program; however the results of the control group were not significant. Also, there were significant differences between both groups at the end of the study.Conclusion: Weight loss modulates immune system parameters of patients with HCV.Keywords: Hepatitis C virus, obesity, immune system, weight reduction

Moving beyond access: Towards a quality-orientated substance abuse treatment system in South Africa

There is growing concern about the increased demand for and limited access to substance abuse treatment in South Africa. The government has responded by allocating more money to the delivery of substance abuse treatment, expanding the number of state-funded treatment slots, and training additional health and social workers to deliver these services, particularly in provinces where the prevalence of substance-related problems is high, such as the Western Cape. While these efforts should be commended and continued, steps to improve service availability have occurred without adequate consideration of the quality of services provided. This is not surprising, as there is little or no routine monitoring and evaluation of substance abuse services in the country. It is also disquieting, as access to treatment is necessary but not sufficient for positive treatment outcomes

The influence of green modification of lignin on the electrochemical properties of biocomposites for industrial applications

It’s a report on a novel approach; preparation and electrochemical properties of modified lignin. Wax and starch were used as natural, green adhesives for enhancing the electrical resistivity of lignin in acidic medium, forming eco-friendly high insulator biocomposite. Scanning electron microscopy (SEM) was used to characterize the fabricated biocomposite. The modified lignin was characterized using Fourier transform infrared (FTIR), while the electrochemical behavior was examined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The innovative approach described in this work provides a promising eco- friendly method for lignin modification with highly electrical resistivity and stability with time.Â