In this study, the performance improvement of a payload angle deflection of a gantry crane has been studied and simulated using MATLAB/Simulink toolbox successfully. H2 optimal and observer based controllers has been used to minimize the payload angular deflection by controlling the trolley position. The gantry crane has been compared with the proposed controllers to track the reference trolley position using step and sine wave signals and a promising results have been achieved.

This paper offers a short survey of linear systems Proportional-Integral-Observer design. This observer has the capacity to estimate simultaneously the states and unknown inputs which include disturbances or model uncertainties appearing on the system. The design of state and output estimation using PO and state, output and disturbance estimation using PIO is done using Matlab/Simulink successfully. The simulation is done for estimating using PO and PIO and the results proved that estimates the state variables and output correctly when there is (...) no disturbance in the plant and there is a constant steady-state error in estimation after leading a constant disturbance into the plant for both state variables and plant output for the Proportional Observer and there is ability to estimate state variables, disturbance and system output correctly with or without the disturbance in plant for the Proportional Integral Observer. (shrink)

Continuous Stirred Tank Reactor (CSTR) is amajorarea in process, chemical and control engineering. In this paper, PID and MPC controllers are designed for CSTR in order to analyze the output concentration of the system by comparing the two proposed systems using Matlab/Simulink. Comparison have been made using two desired concentration input (Random reference and step) signals with and without input side disturbance (Flow rate error). The simulation result shows that the continuous stirred tank reactor with MPC controller have better response (...) in minimizing the overshoot and tracking the desired concentration for the system without input disturbance and with the effect of the disturbance makes the continuous stirred tank reactor with MPC controller output with small fluctuations and still better than the continuous stirred tank reactor with PID controller. Finally the comparative analysis and simulation results prove the effectiveness of the continuous stirred tank reactor with MPC controller. (shrink)

In this paper, a Magnetic Levitation (MAGLEV) train is designed with a first degree of freedom electromagnetbased totally system that permits to levitate vertically up and down. Fuzzy logic, PID and MRAS controllers are used to improve the Magnetic Levitation train passenger comfort and road handling. A Matlab Simulink model is used to compare the performance of the three controllers using step input signals. The stability of the Magnetic Levitation train is analyzed using root locus technique. Controller output response for (...) different time period and change of air gap with different time period is analyzed for the three controllers. Finally the comparative simulation and experimental results demonstrate the effectiveness of the presented fuzzy logic controller. (shrink)

In this study, the design and control of a hydraulic system based tire changer machine have been analyzed and simulated using MATLAB/Simulink Toolbox successfully. The machine have a displacement input which is a leg pedal displacement in order to push the piston of the pump to fed the motor with a pressured hydraulic fluid to rotate the tire with an angular speed to mount and dismount it. Augmentation based H4 and H2 optimal synthesis controllers have been used to improve the (...) performance of the machine. Comparison of the proposed controllers for tracking a reference input speed have been done using two reference inputs (step and random) signals. Finally, the comparative simulation results proved the effectiveness of the proposed tire changer with synthesis controller in improving the settling time and percentage overshoot. (shrink)

This study considers the problem of using approximate way for realizing the neural supervisor for nonlinear multivariable systems. The Nonlinear Autoregressive-Moving Average (NARMA) model is an exact transformation of the input-output behavior of finite-dimensional nonlinear discrete time dynamical organization in a hoodlum of the equilibrium state. However, it is not convenient for intention of adaptive control using neural networks due to its nonlinear dependence on the control input. Hence, quite often, approximate technique are used for realizing the neural supervisor to (...) overcome computational complexity. In this study, we introduce two classes of ideal which are approximations to the NARMA model and which are linear in the control input, namely NARMA-L1 and NARMA-L2. The latter fact substantially simplifies both the theoretical breakdown as well as the practical request of the controller. Extensive imitation studies have shown that the neural controller designed using the proposed approximate models perform very well and in dozens situation even better than an approximate controller designed using the exact NARMA Model. In view of their mathematical tractability as well as their fate in simulation studies, a matter is made in this study that such approximate input-output paragon warrants a detailed study in their own right. (shrink)

This study investigates the outlet temperature control for the design of steam condenser. The comparison has been made for a step drop in the steam condenser temperature set point using MATLAB/ Simulink environment for the steam condenser with NARMA-L2 using Levenberg-Marquardt algorithm and NARMA-L2 using resilient backpropagation algorithm controllers. The steam condenser with NARMA-L2 using Levenberg-Marquardt algorithm controller presented excellent and superior dynamic performance in response to the temperature drop in settling time. The overall simulation results demonstrated that the steam (...) condenser with NARMA-L2 using Levenberg-Marquardt Algorithm controller can be an efficient alternative to the steam condenser with NARMA-L2 using resilient backpropagation algorithm controller. (shrink)

Recent years, active suspension system has been widely used in automobiles to improve the road holding ability and the riding comfort. This study presents a new fuzzy model predictive control for a nonlinear quarter car active suspension system. A nonlinear dynamical model of active suspension is established, where the nonlinear dynamical characteristic of the spring and damper are considered. Based on the proposed fuzzy model predictive control method is presented to stabilize the displacement of the active suspension in the presence (...) of different road profiles. Parameters of the model predictive and fuzzy logic control laws are designed to estimate the (Bump and Sinusoidal)road profile input in the active suspension. At last, the reliability of the fuzzy model predictive control method is evaluated by the MATLAB simulation tool. Simulation result shows that the fuzzy model predictive control method obtained the satisfactory control performance for the active suspension system. (shrink)

In this study, the performance of inverted pendulum has been Investigated using neural network control theory. The proposed controllers used in this study are NARMA-L2 with Resilient backpropagation and Levenberg Marquardt backpropagation algorithm controllers. The mathematical model of Inverted Pendulum on a Cart driving mechanism have been done successfully. Comparison of an inverted pendulum with NARMA-L2 with Resilient backpropagation and Levenberg Marquardt backpropagation algorithm controllers for a control target deviation of an angle from vertical of the inverted pendulum using two (...) input signals (step and random). The simulation result shows that the inverted pendulum with NARMA-L2 with resilient backpropagation controller to have a small rise time, settling time and percentage overshoot in the step response and having a good response in the random response too. Finally, the inverted pendulum with with NARMA-L2 with resilient backpropagation controller shows the best performance in the overall simulation result. (shrink)

In this study, a 2 DOF industrial robotic arm is designed and simulated for elbow and wrist angle and velocity performance improvement using robust control method. Mixed H2/H infinity synthesis with regional pole placement and H2 optimal controllers are used to improve the system output. The open loop response of the robot arm shows that the elbow and wrist angles and velocities need some improvement. Comparison of the proposed controllers for an impulse and step input signals have been done and (...) a promising results have been obtained. (shrink)

An AC servomotor which is mostly a two-phase induction motor with two stator field coils placed 90 electrical degrees apart used for controlling position, speed and acceleration in manufacturing industries. In this paper, a two-phase induction motor has been designed with a fuzzy logic and observer based controllers to improve the performance of the system. Comparison of the AC servomotor with the proposed controllers for tracking a step and a square desired position signal input has been done using Matlab/Simulink toolbox (...) and a promising result obtained. (shrink)

Magnetic levitation system is operated primarily based at the principle of magnetic attraction and repulsion to levitate the passengers and the train. However, magnetic levitation trains are rather nonlinear and open loop unstable which makes it hard to govern. In this paper, investigation, design and control of a nonlinear Maglev train based on NARMA-L2, model reference and predictive controllers. The response of the Maglev train with the proposed controllers for the precise role of a Magnetic levitation machine have been as (...) compared for a step input signal. The simulation consequences prove that the Maglev teach system with NARMA-L2 controller suggests the quality performance in adjusting the precise function of the system and the device improves the experience consolation and street managing criteria. (shrink)

Noise reduction is the major issue in the loudspeaker for the application of the musical instruments and related areas. In this study, a noise disturbance control of a loudspeaker with optimal and robust controllers has been done successfully. The noise of the loudspeaker has been analyzed by simply track a reference cone displacement with the actual cone displacement. Static output feedback and H4 optimal loop shaping controllers have been used to compare the actual and reference cone displacements by using a (...) sine wave and random cone displacement signals and a promising results have been analyzed. (shrink)

In this study, the design and performance investigation of the permanent magnet machines have been done to increase the mechanical and electrical outputs improvement of the systems. A Permanent Magnet DC Motor (PMDM) and Generator (PMDG) have been modelled and designed to improve the angular position and generated current respectively. In this research, augmentation based H2 optimal and H4 synthesis controllers have been designed as a controller for the two systems and a comparison between the proposed controller for tracking a (...) reference inputs and a promising results have been obtained. (shrink)

To improve the riding performance and levitation stability of a high‐speed magnetic levitation (maglev) train, a control strategy based on mixed H 2/H4 with regional pole placement and model‐reference controllers are proposed. First, the nonlinear maglev train model is established, then the proposed system is designed to observe the movement of a suspension frame and a control strategy based on mixed H 2/H4 with regional pole placement and model‐reference control method are proposed. Test and analysis of the proposed system has (...) been done using MATLAB toolbox for train levitation height, velocity and current consume. Comparative simulation results show that the mixed H 2/H4 with regional pole placement control strategy has a better performance under the condition of step and random train levitation height. (shrink)

In this study, a two-link manipulator system stability performance is designed and analyzed using optimal control technique. The manipulator system is highly nonlinear and unstable. The system is modelled using Lagrangian equation and linearized in upward unstable position. The closed loop system is designed using optimal sliding mode controller. The system is compared with a known PID controller with an impulse applied and disturbance torques and a promising results has been obtained.

Electromagnetic Suspension System (EMS) is mostly used in the field of high-speed vehicle. In this study, a space exploring vehicle quarter electromagnetic suspension system is modelled, designed and simulated using Neural network-based control problem. NARMA-L2, Model reference and predictive controllers are designed to improve the body travel of the vehicle using bump road profile. Comparison between the proposed controllers is done and a promising simulation result have been analyzed.

Shell tube surface condenser (STSC) is a heat exchanger system that exchange a high pressure steam into low pressure water and it is widely used in applications like textile industries and nuclear power plants. The modelling of the system has been established based on lumped parameters. In this paper, a fuzzy expert system is developed in order to improve the performance of the condenser. A pressure feedback system has been developed to analyze the effect of the condenser output temperature, circulating (...) water flow and heat developed. An experiment has been made for the closed loop system using fuzzy tuned PI, fuzzy logic and PID controllers and a promising results have been obtained successfully. (shrink)

In this paper, a horizontally moving suspended mass pendulum base is designed and controlled using robust control theory. H  optimal loop shaping with first and second order desired loop shaping function controllers are used to improve the performance of the system using Matlab/Simulink Toolbox. Comparison of the H  optimal loop shaping with first and second order desired loop shaping function controllers for the proposed system have been done to track the desired angular position of the pendulum using step (...) and sine wave input signals and a promising result has been obtained succesfully. (shrink)

In this paper, modelling designing and simulation of a Ward Leonard layout system is done using robust control theory. In order to increase the performance of the Ward Leonard layout system with H  optimal control synthesis and H  optimal control synthesis via -iteration controllers are used. The open loop response of the Ward Leonard layout system shows that the system needs to be improved. Comparison of the Ward Leonard layout system with H  optimal control synthesis and H (...)  optimal control synthesis via -iteration controllers to track a desired step speed input have been done. Finally, the comparative simulation results prove the effectiveness of the proposed Ward Leonard layout system with H  optimal control synthesis controller in improving the percentage overshoot and the settling time. (shrink)

In this paper, a vertically moving base inverted pendulum control analysis has been done using Matlab/Simulink Toolbox. Because the vertically moving base inverted pendulum system is nonlinear and highly unstable, a feedback control system is used to make the system controlled and stable. A PI and PID controllers are used to improve the stability of the pendulum. Comparison of the vertically moving base inverted pendulum using PI and PID controllers for tracking a desired angular position of the system using a (...) step and random input signals and a promising results have been obtained succesfully. (shrink)

Recourse to intuition to tackle philosophical issues brought the charge of irrationalism on Bergson. The charge overlooks that Bergsonian intuition has nothing to do with a sudden and mysterious illumination. Rather, it is a methodic procedure resulting in an outcome that it is effectively produced, and not a spark that falls from the sky. This paper shows that the misconception has its source in the neglect of two interrelated factors: (1) philosophical intuition is a method specifically invented to get past (...) philosophical antinomies, as they are framed by Kant; and (2) the method is inseparable from the philosophy of duration, notably from the originality of a monism that generates differences in kind, thereby allowing the enactment of the various modes of being. So that, both the invented nature of philosophical intuition and the stratified attribute of duration combine to give intuition the character of a cognitive breakthrough that is not reducible to the old opposition between rationality and irrationality. -/- . (shrink)

Unlike in Western countries, scholars and the Chinese government pay less attention to the role of extracurricular activities in fostering children’s cognitive and non-cognitive well-being. Accordingly, essential ECAs such as visual arts programs are serviced by expensive privately owned schools, creating social injustice. The primary aim of the current study is to examine whether children benefit from ECAs if parental support and guidance for managing time spent on ECAs and academics exist based on the threshold model. The study comprised over (...) 2,400 primary school students in one Chinese province and considered the SES of the area. Surprisingly, the present study’s findings illustrate that contemporary Chinese parents differ from traditionally aggressive and overbearing parents who do not value their children’s interests. However, the current study finding suggested that children’s participation in out-of-school visual art activities doesn’t have a substantial value in promoting children’s academic performance in the face of genuine interest and supportive parenting, which negates the threshold model. (shrink)

Background: The time before surgery is a traumatic period for patients. Despite this fact, no research has been conducted on nurses’ preoperative patient education in Ethiopia. This study aimed to assess preoperative patient education practices and associated factors among nurses working in East Amhara comprehensive specialized hospitals, Ethiopia, 2022. Methods: A hospital-based cross-sectional study was conducted with 416 nurses. Pretested, structured questionnaires were used to collect the data. Bivariable analysis was performed for each independent variable with a P-value < 0.25 (...) on the data imported to multivariate logistic regression analysis. AOR with a 95% CI and a P-value < 0.05 at a 5% level of significance were considered. Results: Only 38.5% of nurses were found to have good practices for preoperative patient education, with a response rate of 98%. Nurses with 6 years of work experience (AOR = 3.15, 95% CI: 1.692– 5.874), adequate time (AOR = 2.33, 95% CI: 1.119– 4.889), training (AOR = 4.27, 95% CI: 1.548– 11.796), age 25– 29 (AOR = 0.15, 95% CI: 0.070– 0.331), age 30– 34 (AOR = 0.25, 95% CI: 0.137– 0.479), and knowledge (AOR = 3.73, 95% CI: 2.222– 6.273) were significantly associated. Conclusion: Preoperative patient education practices among nurses were poor. Work experience, knowledge, training, and adequate time were found to be significant. Organize preoperative patient education programs for nurses that share experiences and provide ongoing training. (shrink)

The town of Aksum is historically the richest tourist destination in Ethiopia. Thus, it is known for its cultural tourist attractions i.e. archaeological, religious and historical attractions. The objective of this study is to assess the supplies of micro and small scale enterprises to the tourism industry in the town. A qualitative research design was pursued in this study. Data were collected from primary and secondary sources. Interviews were conducted with purposely selected subjects as the main instrument of primary data (...) collection. In addition, field visits were conducted to observe the sites and take pictures. Both published and unpublished secondary sources were used, particularly for the literature review. Participants of this study were selected from the tourism and hotel industry, the Small Scale Enterprises Agency, micro and small scale enterprises, the Culture and Tourism Agency and other government offices. The Ethiopian Sustainable Tourism Development Project (ESTDP) was also consulted to assess the involvement of micro and small scale enterprises in the tourism sector. The findings indicate that micro and small scale enterprises have been divided into the five main economic sectors including agriculture, manufacturing, construction, trade and service sectors. The Ethiopian Sustainable Tourism Development Project has supported the enterprises in working with the tourism industry. The government’s role in organizing and supporting the enterprises however, seems to be weak. Some of the enterprises produce and sell their products to tourism institutions involved as frontline suppliers to the tourists. However, the enterprises are not well-organized and not strong enough to supply the required quantity and quality. Moreover, some of the enterprises don’t have any link with the tourism sector. The policy implications from this study indicate that local government in collaboration with private sectors and voluntary donors should support the local small enterprises to increase their capacity and improve their supplies. (shrink)

The notion of decolonisation implies the existence of a territory, entity, structure, or system which has previously been colonised by exogenous forces and thus needs to be liberated. In most African countries, the discourses of decolonisation of higher education emanate from the shared experience of imposed European colonisation that perpetuated epistemic violence on African indigenous knowledge systems. Thus, a lived experience of colonialism became a foundation for the decolonisation debates imagining and aspiring to alternative and inclusive futures. This point of (...) departure yet makes the discussion of decolonisation as the subject of only those who have had colonial experiences – an event of interruption of a specific process considered colonial and therefore, undesirable. This approach conceptualises decolonisation in a narrow sense as a linear process with a distinct historical beginning, which is colonial, and an envisaged liberating decolonial end. This article critically challenges this dominant narrative of decolonisation and reconceptualises it as a complex, dynamic, and lifelong process of re-centring. It argues that decolonisation, as a concept in higher education, goes beyond a pre-existing colonial foundation. Taking the context of Ethiopia, a country that remained independent during the European colonisation of Africa, this article aims at reconceptualising the notion of decolonisation of higher education in a space that has never been colonised. The article discusses epistemological challenges of the Ethiopian higher education system and provides a proactive alternative future departing from monolithic epistemic tradition to a pluralistic approach that accommodates diverse structures of knowledge. (shrink)

IntroductionInternet addiction is characterized by excessive and uncontrolled use of the internet affecting everyday life. Adolescents are the primary risk group for internet addiction. Data on internet addiction is lacking in Africa. Thus, this review aimed to determine the pooled prevalence of internet addiction and its associated factors among high school and university students in Africa.MethodsA comprehensive literature search was conducted using electronic databases to locate potential studies. Heterogeneity between studies was checked using Cochrane Q test statistics and I2 test (...) statistics and small-study effects were checked using Egger's statistical test at a 5% significance level. A sensitivity analysis was performed. A random-effects model was employed to estimate the pooled prevalence and associated factors of internet addiction among students. The primary outcome of measure of this review was the prevalence of internet addiction and the secondary outcome of measures are the factors associated with internet addiction.ResultsA total of 5,562 studies were identified among the five databases. Of these, 28 studies from 10 countries with 14,946 high school and university students were included in this review. The overall pooled prevalence of internet addiction among the students was 34.53% [95% Confidence Interval : 26.83, 42.23, I2 = 99.20%]. Male sex [Pooled Odds Ratio = 1.92, 95% CI:1.43, 2.57 I2 = 0.00], urban residence, and duration of daily internet use for more than 4 h (POR = 2.25, 95% CI:1.20, 4.21, I2 = 0.00%, were significantly associated with internet addiction among adolescents.ConclusionAlmost one-third of university and high school students in Africa are addicted to the internet. Male students, those from urban areas, and those who use the internet for more than 4 h per day have higher odds of internet addiction. Thus, we recommend that health planners and policymakers pay attention to the use of the internet and internet addiction in Africa. (shrink)

The role of African higher education institutions has been embedded within the socio-economic and historical contexts of the continent. Understanding the nature of African universities, their roles in African societies, and their place in the global knowledge system demands comprehensive reflection of the historical trajectories of the sector itself. In order to re-imagine the future of African higher education, it is important not only to reconstruct the past by uncovering facts but also to deconstruct it by challenging the nature of (...) established truth on which historical evidences are created. This article challenges and deconstructs dominant narratives on the historical trajectories and configurations of progress in African higher education systems. The article provides a thorough analysis of major trends, developments and challenges that the sector has been facing through time with the intention of reimaging and constructing the notion of a new or alternative future that addresses the recurrent challenges of the sector. The notion of creating the new African university carries a fundamental inquiry asking: ‘What it means to be an African university?’ ‘What role do they play in African societies?’ and ‘How do African institutions manage to strike a balance between the individual, social and corporate responsibilities interacting with their stakeholders?’ This article interrogates the intricate pattern of interactions among African societies and higher education institutions, reflecting on historical trends and critical challenges facing the sector that have been negatively impacting the pace of realising the desired future. (shrink)

A number of statistical models have been successfully developed for the analysis of high-throughput data from a single source, but few methods are available for integrating data from different sources. Here we focus on integrating gene expression levels with comparative genomic hybridization array measurements collected on the same subjects. We specify a measurement error model that relates the gene expression levels to latent copy number states which, in turn, are related to the observed surrogate CGH measurements via a hidden Markov (...) model. We employ selection priors that exploit the dependencies across adjacent copy number states and investigate MCMC stochastic search techniques for posterior inference. Our approach results in a unified modeling framework for simultaneously inferring copy number variants and identifying their significant associations with mRNA transcripts abundance. We show performance on simulated data and illustrate an application to data from a genomic study on human cancer cell lines. © Institute of Mathematical Statistics, 2014. (shrink)

Peer review is a widely accepted instrument for raising the quality of science. Peer review limits the enormous unstructured influx of information and the sheer amount of dubious data, which in its absence would plunge science into chaos. In particular, peer review offers the benefit of eliminating papers that suffer from poor craftsmanship or methodological shortcomings, especially in the experimental sciences. However, we believe that peer review is not always appropriate for the evaluation of controversial hypothetical science. We argue that (...) the process of peer review can be prone to bias towards ideas that affirm the prior convictions of reviewers and against innovation and radical new ideas. Innovative hypotheses are thus highly vulnerable to being “filtered out” or made to accord with conventional wisdom by the peer review process. Consequently, having introduced peer review, the Elsevier journal Medical Hypotheses may be unable to continue its tradition as a radical journal allowing discussion of improbable or unconventional ideas. Hence we conclude by asking the publisher to consider re-introducing the system of editorial review to Medical Hypotheses. (shrink)

Autism spectrum disorder is an inherited long-living and neurological disorder that starts in the early age of childhood with complicated causes. Autism spectrum disorder can lead to mental disorders such as anxiety, miscommunication, and limited repetitive interest. If the autism spectrum disorder is detected in the early childhood, it will be very beneficial for children to enhance their mental health level. In this study, different machine and deep learning algorithms were applied to classify the severity of autism spectrum disorder. Moreover, (...) different optimization techniques were employed to enhance the performance. The deep neural network performed better when compared with other approaches. (shrink)

Élaborés dans les années 1950-1960 par les théoriciens du développement, étoffés par la vague féministe des années 1970 et conceptualisés par les tiers mondistes des années 1980, les thèmes des femmes et du développement concentrent aujourd'hui l'attention des chercheurs et des activistes. Thèmes liés, surtout quand on évoque l'Afrique, leur association permet de donner un relief, qu'on leur a souvent refusé, aux femmes africaines sans voix, colporteuses et revendeuses dans les marchés...