Search results for: direct current control
Commenced in January 2007
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Edition: International

Search results for: direct current control

Exploration of Perceived Value of a Special Education Laws and Ethics’ Course Impact on Administrator Capacity

Authors: Megan Chaney

Abstract:

In the United States, research continues to show school administrators do not view themselves as adequately prepared in the area of special education. Often, special education is an omitted topic of study for school administrator preparation programs. The majority of special education teachers do not view their principals as well-prepared to support them in the educational context. Administrator preparation in the area of special education may begin at the foundational levels of understanding but is fundamentally an equity issue when serving individuals from marginalized populations with an urgent need to increase inclusionary practices. Special education and building-level administrators have a direct impact on teacher quality, instructional practices, inclusion, and equity with the opportunity to shape positive school culture. The current study was situated within an innovative IHE/LEA partnership pathway implemented with current K-12 administrators earning a Mild/Moderate Education Specialist Credential or coursework equivalent. Specifically, the study examined administrator’s perception of the Special Education Laws and Ethics’ course value and impact on the capacity to serve children with exceptionalities within the comprehensive school site context.

Keywords: special education laws and ethics, school adminstrator perspectives, school administrator training, inclusive practices

Procedia PDF Downloads 113
A Study on the Small Biped Soft Robot with Two Insect-Like Nails

Authors: Mami Nishida

Abstract:

This paper presented a study on the development and control of a small biped soft robot using shape memory alloys (SMAs). Author proposed a flexible flat plate (FFP) actuators consisting of a thin polyethylene plate and SMAs. This actuator has a nail like an insect. This robot moves from the front to back and from left to right using two nails. The walking robot has two degrees of freedom and is controlled by switching the ON-OFF current signals to the SMA based FFPs. The resulting small biped soft robot weighs a mere 4.7 g (with a height of 67 mm). The small robot realizes biped walking by transferring the elastic potential energy (generated by deflections of the SMA based FFPs) to kinematic energy. Experimental results demonstrated the viability and utility of the small biped soft robot with the proposed SMA-based FFPs and the control strategy to achieve walking behavior.

Keywords: biped soft robot with nails, flexible flat plate (FFP) actuators, ON-OFF control strategy, shape memory alloys (SMA)

Procedia PDF Downloads 507
Designing Intelligent Adaptive Controller for Nonlinear Pendulum Dynamical System

Authors: R. Ghasemi, M. R. Rahimi Khoygani

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This paper proposes the designing direct adaptive neural controller to apply for a class of a nonlinear pendulum dynamic system. The radial basis function (RBF) neural adaptive controller is robust in presence of external and internal uncertainties. Both the effectiveness of the controller and robustness against disturbances are importance of this paper. The simulation results show the promising performance of the proposed controller.

Keywords: adaptive neural controller, nonlinear dynamical, neural network, RBF, driven pendulum, position control

Procedia PDF Downloads 486
Improving Cost and Time Control of Construction Projects Management Practices in Nigeria

Authors: Mustapha Yakubu, Ahmed Usman, Hashim Ambursa

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This paper presents the findings of a research which sought to investigate techniques used to improve cost and time control of construction projects management practice in Nigeria. However, there is limited research on issues surrounding the practical usage of these techniques. Data were collected through a questionnaire distributed to construction experts through a survey conducted on the 100 construction organisations and 50 construction consultancy firms in the Nigeria aimed at identifying common project cost and time control practices and factors inhibiting effective project control in practice. The study reveals that despite the vast application of control techniques a high proportion of respondents still experienced cost and time overruns on a significant proportion of their projects. Analysis of the survey results concluded that more effort should be geared at the management of the identified top project control inhibiting factors. This paper has outlined some measures for mitigating these inhibiting factors so that the outcome of project time and cost control can be improved in practice.

Keywords: construction project, cost control, Nigeria, time control

Procedia PDF Downloads 319
Modeling and Simulation for 3D Eddy Current Testing in Conducting Materials

Authors: S. Bennoud, M. Zergoug

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The numerical simulation of electromagnetic interactions is still a challenging problem, especially in problems that result in fully three dimensional mathematical models. The goal of this work is to use mathematical modeling to characterize the reliability and capacity of eddy current technique to detect and characterize defects embedded in aeronautical in-service pieces. The finite element method is used for describing the eddy current technique in a mathematical model by the prediction of the eddy current interaction with defects. However, this model is an approximation of the full Maxwell equations. In this study, the analysis of the problem is based on a three dimensional finite element model that computes directly the electromagnetic field distortions due to defects.

Keywords: eddy current, finite element method, non destructive testing, numerical simulations

Procedia PDF Downloads 448
Machine Learning and Internet of Thing for Smart-Hydrology of the Mantaro River Basin

Authors: Julio Jesus Salazar, Julio Jesus De Lama

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the fundamental objective of hydrological studies applied to the engineering field is to determine the statistically consistent volumes or water flows that, in each case, allow us to size or design a series of elements or structures to effectively manage and develop a river basin. To determine these values, there are several ways of working within the framework of traditional hydrology: (1) Study each of the factors that influence the hydrological cycle, (2) Study the historical behavior of the hydrology of the area, (3) Study the historical behavior of hydrologically similar zones, and (4) Other studies (rain simulators or experimental basins). Of course, this range of studies in a certain basin is very varied and complex and presents the difficulty of collecting the data in real time. In this complex space, the study of variables can only be overcome by collecting and transmitting data to decision centers through the Internet of things and artificial intelligence. Thus, this research work implemented the learning project of the sub-basin of the Shullcas river in the Andean basin of the Mantaro river in Peru. The sensor firmware to collect and communicate hydrological parameter data was programmed and tested in similar basins of the European Union. The Machine Learning applications was programmed to choose the algorithms that direct the best solution to the determination of the rainfall-runoff relationship captured in the different polygons of the sub-basin. Tests were carried out in the mountains of Europe, and in the sub-basins of the Shullcas river (Huancayo) and the Yauli river (Jauja) with heights close to 5000 m.a.s.l., giving the following conclusions: to guarantee a correct communication, the distance between devices should not pass the 15 km. It is advisable to minimize the energy consumption of the devices and avoid collisions between packages, the distances oscillate between 5 and 10 km, in this way the transmission power can be reduced and a higher bitrate can be used. In case the communication elements of the devices of the network (internet of things) installed in the basin do not have good visibility between them, the distance should be reduced to the range of 1-3 km. The energy efficiency of the Atmel microcontrollers present in Arduino is not adequate to meet the requirements of system autonomy. To increase the autonomy of the system, it is recommended to use low consumption systems, such as the Ashton Raggatt McDougall or ARM Cortex L (Ultra Low Power) microcontrollers or even the Cortex M; and high-performance direct current (DC) to direct current (DC) converters. The Machine Learning System has initiated the learning of the Shullcas system to generate the best hydrology of the sub-basin. This will improve as machine learning and the data entered in the big data coincide every second. This will provide services to each of the applications of the complex system to return the best data of determined flows.

Keywords: hydrology, internet of things, machine learning, river basin

Procedia PDF Downloads 165
Realization of Wearable Inertial Measurement Units-Sensor-Fusion Harness to Control Therapeutic Smartphone Applications

Authors: Svilen Dimitrov, Manthan Pancholi, Norbert Schmitz, Didier Stricker

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This paper presents the end-to-end development of a wearable motion sensing harness consisting of computational unit and four inertial measurement units to control three smartphone therapeutic games for children. The inertial data is processed in real time to obtain lower body motion information like knee raises, feet taps and squads. By providing a Wi-Fi connection interface the sensor harness acts wireless remote control for smartphone applications. By performing various lower body movements the users provoke corresponding game state changes. In contrary to the current similar offers, like Nintendo Wii Remote, Xbox Kinect and Playstation Move, this product, consisting of the sensor harness and the applications on top of it, are fully wearable, which means they do not rely on the user to be bound to concrete soft- or hardwareequipped space.

Keywords: wearable harness, inertial measurement units, smartphone therapeutic games, motion tracking, lower-body activity monitoring

Procedia PDF Downloads 407
Numerical Simulations on Feasibility of Stochastic Model Predictive Control for Linear Discrete-Time Systems with Random Dither Quantization

Authors: Taiki Baba, Tomoaki Hashimoto

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The random dither quantization method enables us to achieve much better performance than the simple uniform quantization method for the design of quantized control systems. Motivated by this fact, the stochastic model predictive control method in which a performance index is minimized subject to probabilistic constraints imposed on the state variables of systems has been proposed for linear feedback control systems with random dither quantization. In other words, a method for solving optimal control problems subject to probabilistic state constraints for linear discrete-time control systems with random dither quantization has been already established. To our best knowledge, however, the feasibility of such a kind of optimal control problems has not yet been studied. Our objective in this paper is to investigate the feasibility of stochastic model predictive control problems for linear discrete-time control systems with random dither quantization. To this end, we provide the results of numerical simulations that verify the feasibility of stochastic model predictive control problems for linear discrete-time control systems with random dither quantization.

Keywords: model predictive control, stochastic systems, probabilistic constraints, random dither quantization

Procedia PDF Downloads 284
The Factors of Supply Chain Collaboration

Authors: Ghada Soltane

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The objective of this study was to identify factors impacting supply chain collaboration. a quantitative study was carried out on a sample of 84 Tunisian industrial companies. To verify the research hypotheses and test the direct effect of these factors on supply chain collaboration a multiple regression method was used using SPSS 26 software. The results show that there are four factors direct effects that affect supply chain collaboration in a meaningful and positive way, including: trust, engagement, information sharing and information quality

Keywords: supply chain collaboration, factors of collaboration, principal component analysis, multiple regression

Procedia PDF Downloads 56
Flywheel Energy Storage Control Using SVPWM for Small Satellites Application

Authors: Noha El-Gohary, Thanaa El-Shater, A. A. Mahfouz, M. M. Sakr

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Searching for high power conversion efficiency and long lifetime are important goals when designing a power supply subsystem for satellite applications. To fulfill these goals, this paper presents a power supply subsystem for small satellites in which flywheel energy storage system is used as a secondary power source instead of chemical battery. In this paper, the model of flywheel energy storage system is introduced; a DC bus regulation control algorithm for charging and discharging of flywheel based on space vector pulse width modulation technique and motor current control is also introduced. Simulation results showed the operation of the flywheel for charging and discharging mode during illumination and shadowed period. The advantages of the proposed system are confirmed by the simulation results of the power supply system.

Keywords: small-satellites, flywheel energy storage system, space vector pulse width modulation, power conversion

Procedia PDF Downloads 402
Reforming the Law to Allow a Duress Defence to Those Committing Crime under Coercive Control

Authors: Amy Elkington

Abstract:

Women in abusive relationships who commit crimes under duress are unfairly treated by the English legal system. Despite the offence of Coercive Control being introduced in 2015 that recognises that a woman’s autonomy has been eroded, coercion is no longer a defence to women who feel compelled to act due to their partner’s behavior or abuse. This problem is intensified by the fact that women in abusive relationships are more likely to commit crimes to ensure their survival. Furthermore, the very fact that they are ‘associating’ with their abusive partners means that they are excluded from pleading a defence of duress. Women who kill their abusers may be able to reduce their conviction from murder to manslaughter, but this depends on successfully pleading either loss of control or diminished responsibility, both not without their issues, but this does not provide a defence where a lesser crime is committed. Self-defence is also widely unavailable to either murder or non-fatal offences, as the amount of force used is often deemed disproportionate because women are more likely to use weapons in their defence. Regardless, this would not provide a defence where the crime committed is one such as theft. An alternative that has been proposed would be to introduce a new defence that would work similarly to the exemption to prosecution afforded to those who are trafficked that commit crime under duress. Despite having support in the Lords in March 2021, this recommendation has been rejected by the Government on the basis that it would not achieve an appropriate balance of justice. The result is that abused women who commit crime are left without an appropriate defence. A doctrinal approach highlights the injustices in these types of cases and concludes that it is time for the current law of duress to change.

Keywords: coercive control, crime, defences, duress

Procedia PDF Downloads 199
Effect of Erythropoietin Hormone Supplementation on Hypoxia-Inducible Factor1-Alpha in Rat Kidneys with Experimental Diabetic Nephropathy

Authors: Maha Deif, Alaa Eldin Hassan, Eman Shaat, Nesrine Elazhary, Eman Magdy

Abstract:

Background: Erythropoietin (EPO) is a hematopoietic factor with multiple protective effects. The aim of the present study was to investigate the potential effect of EPO administration on renal functions and hypoxia inducible factor 1-alpha (HIF-1a) in diabetic rat kidneys. Methodology: The current study was carried out on 40 male albino rats divided into four groups (n= 10 in each). Group I served as normal control, group II was the diabetic control, group III rats received EPO on the same day of diagnosis of diabetes mellitus (DM), while group IV received the first dose of EPO 2 weeks after the diagnosis of DM. Results: The results showed that EPO supplementation leads to a significant decrease in serum urea, urinary protein and creatinine clearance as well as a significant increase in renal HIF-1a in group III and IV rats compared to the diabetic control group (group II). However, fasting blood glucose was significantly decreased in group III as compared to the diabetic control group in the third week, but no significant difference was reported in the fourth week among groups II, III and IV. Conclusion: EPO administration leads to the improvement of renal functions and increased levels of HIF-1a in diabetic rats.

Keywords: erythropoietin, diabetic nephropathy, hypoxia-inducible factor1-alpha, renal functions

Procedia PDF Downloads 289
Convergence Analysis of Reactive Power Based Schemes Used in Sensorless Control of Induction Motors

Authors: N. Ben Si Ali, N. Benalia, N. Zerzouri

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Many electronic drivers for the induction motor control are based on sensorless technologies. Speed and torque control is usually attained by application of a speed or position sensor which requires the additional mounting space, reduce the reliability and increase the cost. This paper seeks to analyze dynamical performances and sensitivity to motor parameter changes of reactive power based technique used in sensorless control of induction motors. Validity of theoretical results is verified by simulation.

Keywords: adaptive observers, model reference adaptive system, RP-based estimator, sensorless control, stability analysis

Procedia PDF Downloads 551
Analysis of Cascade Control Structure in Train Dynamic Braking System

Authors: B. Moaveni, S. Morovati

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In recent years, increasing the usage of railway transportations especially in developing countries caused more attention to control systems railway vehicles. Consequently, designing and implementing the modern control systems to improve the operating performance of trains and locomotives become one of the main concerns of researches. Dynamic braking systems is an important safety system which controls the amount of braking torque generated by traction motors, to keep the adhesion coefficient between the wheel-sets and rail road in optimum bound. Adhesion force has an important role to control the braking distance and prevent the wheels from slipping during the braking process. Cascade control structure is one of the best control methods for the wide range of industrial plants in the presence of disturbances and errors. This paper presents cascade control structure based on two forward simple controllers with two feedback loops to control the slip ratio and braking torque. In this structure, the inner loop controls the angular velocity and the outer loop control the longitudinal velocity of the locomotive that its dynamic is slower than the dynamic of angular velocity. This control structure by controlling the torque of DC traction motors, tries to track the desired velocity profile to access the predefined braking distance and to control the slip ratio. Simulation results are employed to show the effectiveness of the introduced methodology in dynamic braking system.

Keywords: cascade control, dynamic braking system, DC traction motors, slip control

Procedia PDF Downloads 370
Relationship between the Ability of Accruals and Non-Systematic Risk of Shares for Companies Listed in Stock Exchange: Case Study, Tehran

Authors: Lina Najafian, Hamidreza Vakilifard

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The present study focused on the relationship between the quality of accruals and non-systematic risk. The independent study variables included the ability of accruals, the information content of accruals, and amount of discretionary accruals considered as accruals quality measures. The dependent variable was non-systematic risk based on the Fama and French Three Factor model (FFTFM) and the capital asset pricing model (CAPM). The control variables were firm size, financial leverage, stock return, cash flow fluctuations, and book-to-market ratio. The data collection method was based on library research and document mining including financial statements. Multiple regression analysis was used to analyze the data. The study results showed that there is a significant direct relationship between financial leverage and discretionary accruals and non-systematic risk based on FFTFM and CAPM. There is also a significant direct relationship between the ability of accruals, information content of accruals, firm size, and stock return and non-systematic based on both models. It was also found that there is no relationship between book-to-market ratio and cash flow fluctuations and non-systematic risk.

Keywords: accruals quality, non-systematic risk, CAPM, FFTFM

Procedia PDF Downloads 162
Effect of Salvadora Persica Gel on Clinical and Microbiological Parameters of Chronic Periodontitis

Authors: Tahira Hyder, Saima Quraeshi, Zohaib Akram

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Salvadora Persica (SP) is known to have anti-inflammatory, antioxidant, anti-coagulant and anti-bacterial properties that may provide therapeutic benefits in the treatment of chronic periodontitis (CP). The current clinical trial was designed to investigate the clinical and anti-microbial effects of SP gel as an adjunct to scaling and root planning (SRP) in subjects with generalized CP. Sixty-six subjects with CP were randomized allocated into two groups: SRP + SP gel (test group) and SRP only (control group). Clinical parameters (periodontal pocket depth, gingival recession, clinical attachment level, bleeding score and plaque score) were recorded at baseline before SRP and at 6 weeks. At baseline and 6 weeks subgingival plaque samples were collected and periodontopathogen Porphyromonas Gingivalis (Pg) quantified using Real-time Polymerase Chain Reaction (RT-PCR). Both therapies reduced the mean periodontal pocket depth (PPD), plaque score (PS) and bleeding score (BOP) and improved the mean clinical attachment level (CAL) between baseline and 6 weeks. In subjects receiving adjunctive SP gel a statistically significant improvement was observed in BOP at follow-up compared to control group (15.01±3.47% and 22.81±6.81% respectively, p=0.001), while there was no statistically significant difference in periodontal pocket depth, gingival recession, clinical attachment level and plaque score between both groups. The test group displayed significantly greater Pg reduction compared to the control group after 6 weeks. The current study establishes that local delivery of SP gel into periodontal pocket in CP stimulated a significant reduction in bacteria Pg level and an improvement in gingival health, as evident from a reduced bleeding score, when used as an adjunct to SRP.

Keywords: miswak, scaling and root planing, porphyromonas gingivalis, chronic periodontitis

Procedia PDF Downloads 91
Blood Flow Estimator of the Left Ventricular Assist Device Based in Look-Up-Table: In vitro Tests

Authors: Tarcisio F. Leao, Bruno Utiyama, Jeison Fonseca, Eduardo Bock, Aron Andrade

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This work presents a blood flow estimator based in Look-Up-Table (LUT) for control of Left Ventricular Assist Device (LVAD). This device has been used as bridge to transplantation or as destination therapy to treat patients with heart failure (HF). Destination Therapy application requires a high performance LVAD; thus, a stable control is important to keep adequate interaction between heart and device. LVAD control provides an adequate cardiac output while sustaining an appropriate flow and pressure blood perfusion, also described as physiologic control. Because thrombus formation and system reliability reduction, sensors are not desirable to measure these variables (flow and pressure blood). To achieve this, control systems have been researched to estimate blood flow. LVAD used in the study is composed by blood centrifugal pump, control, and power supply. This technique used pump and actuator (motor) parameters of LVAD, such as speed and electric current. Estimator relates electromechanical torque (motor or actuator) and hydraulic power (blood pump) via LUT. An in vitro Mock Loop was used to evaluate deviations between blood flow estimated and actual. A solution with glycerin (50%) and water was used to simulate the blood viscosity with hematocrit 45%. Tests were carried out with variation hematocrit: 25%, 45% and 58% of hematocrit, or 40%, 50% and 60% of glycerin in water solution, respectively. Test with bovine blood was carried out (42% hematocrit). Mock Loop is composed: reservoir, tubes, pressure and flow sensors, and fluid (or blood), beyond LVAD. Estimator based in LUT is patented, number BR1020160068363, in Brazil. Mean deviation is 0.23 ± 0.07 L/min for mean flow estimated. Larger mean deviation was 0.5 L/min considering hematocrit variation. This estimator achieved deviation adequate for physiologic control implementation. Future works will evaluate flow estimation performance in control system of LVAD.

Keywords: blood pump, flow estimator, left ventricular assist device, look-up-table

Procedia PDF Downloads 190
Drying of Agro-Industrial Wastes Using a Cabinet Type Solar Dryer

Authors: N. Metidji, O. Badaoui, A. Djebli, H. Bendjebbas, R. Sellami

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The agro-industry is considered as one of the most waste producing industrial fields as a result of food processing. Upgrading and reuse of these wastes as animal or poultry food seems to be a promising alternative. Combined with the use of clean energy resources, the recovery process would contribute more to the environment protection. It is in this framework that a new solar dryer has been designed in the Unit of Solar Equipment Development. Direct solar drying has, also, many advantages compared to natural sun drying. In fact, the first does not cause product degradation as it is protected by the drying chamber from direct sun, insects and exterior environment. The aim of this work is to study the drying kinetics of waste, generated during the processing of pepper, by using a direct natural convection solar dryer at 35◦C and 55◦C. The rate of moisture removal from the product to be dried has been found to be directly related to temperature, humidity and flow rate. The characterization of these parameters has allowed the determination of the appropriate drying time for this product namely peppers waste.

Keywords: solar energy, solar dryer, energy conversion, pepper drying, forced convection solar dryer

Procedia PDF Downloads 417
Time-Series Analysis of Port State Control Inspections for Tankers

Authors: Chien-Chung Yuan, Cunqiang Cai, Wu-Hsun Chung, Shu-Te Sung

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A tanker is a critical vessel used to transport or store liquids or gases in bulk in maritime shipping. However, it is more dangerous than other types of vessels. Port State Control (PSC) inspection is an important measure to ensure maritime safety when such vessels traveling between ports. However, the current inspection system lacks a useful tool to observe the inspections for tankers and to identify non-random instances in PSC inspections. This study collects the inspection records in Taiwan’s ports from 2015 to 2018 and utilizes run charts to map the PSC inspections for tankers in terms of deficiencies. Based on these time-series charts, several patterns of deficiencies are identified. The results demonstrate that run charts are a useful tool to observe how the PSC inspections for tankers are performed. Also, the charts can help port administrations to identify abnormal phenomena for further investigation. Furthermore, with valuable information from the analysis, port administrations can take proactive improvement measures to ensure the safety of tanker shipping.

Keywords: port state control, tanker, run chart, deficiency

Procedia PDF Downloads 165
Optimal Control of DC Motor Using Linear Quadratic Regulator

Authors: Meetty Tomy, Arxhana G Thosar

Abstract:

This paper provides the implementation of optimal control for an armature-controlled DC motor. The selection of error weighted Matrix and control weighted matrix in order to implement optimal control theory for improving the dynamic behavior of DC motor is presented. The closed loop performance of Armature controlled DC motor with derived linear optimal controller is then evaluated for the transient operating condition (starting). The result obtained from MATLAB is compared with that of PID controller and simple closed loop response of the motor.

Keywords: optimal control, DC motor, performance index, MATLAB

Procedia PDF Downloads 415
Analysis of the Impact of Foreign Direct Investment on the Integration of the Automotive Industry of Iran into Global Production Networks

Authors: Bahareh Mostofian

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Foreign Direct Investment (FDI) has long been recognized as a crucial driver of economic growth and development in less-developed countries and their integration into Global Production Networks (GPNs). FDI not only brings capital from the core countries but also technology, innovation, and know-how knowledge that can upgrade the capabilities of host automotive industries. On the other hand, FDI can also have negative impacts on host countries if it leads to significant import dependency. In the case of the Iranian automotive sector, the industry greatly benefited from FDI, with Western carmakers dominating the market. Over time, various types of know-how knowledge, including joint ventures (JVs), trade licenses, and technical assistance, have been provided, helping Iran upgrade its automotive industry. While after the severe geopolitical obstacles imposed by both the EU and the U.S., the industry became over-reliant on the car and spare parts imports, and the lack of emphasis on knowledge transfer further affected the growth and development of the Iranian automotive sector. To address these challenges, current research has adopted a descriptive-analytical methodology to illustrate the gradual changes accrued with foreign suppliers through FDI. The research finding shows that after the two-phase imposed sanctions, the detrimental linkages created by overreliance on the car and spare parts imports without any industrial upgrading negatively affected the growth and development of the national and assembled products of the Iranian automotive sector.

Keywords: less-developed country, FDI, GPNs, automotive industry, Iran

Procedia PDF Downloads 76
Hydrodynamic Simulation of Co-Current and Counter Current of Column Distillation Using Euler Lagrange Approach

Authors: H. Troudi, M. Ghiss, Z. Tourki, M. Ellejmi

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Packed columns of liquefied petroleum gas (LPG) consists of separating the liquid mixture of propane and butane to pure gas components by the distillation phenomenon. The flow of the gas and liquid inside the columns is operated by two ways: The co-current and the counter current operation. Heat, mass and species transfer between phases represent the most important factors that influence the choice between those two operations. In this paper, both processes are discussed using computational CFD simulation through ANSYS-Fluent software. Only 3D half section of the packed column was considered with one packed bed. The packed bed was characterized in our case as a porous media. The simulations were carried out at transient state conditions. A multi-component gas and liquid mixture were used out in the two processes. We utilized the Euler-Lagrange approach in which the gas was treated as a continuum phase and the liquid as a group of dispersed particles. The heat and the mass transfer process was modeled using multi-component droplet evaporation approach. The results show that the counter-current process performs better than the co-current, although such limitations of our approach are noted. This comparison gives accurate results for computations times higher than 2 s, at different gas velocity and at packed bed porosity of 0.9.

Keywords: co-current, counter-current, Euler-Lagrange model, heat transfer, mass transfer

Procedia PDF Downloads 216
A Study on the Functional Safety Analysis of Stage Control System Based on International Electronical Committee 61508-2

Authors: Youn-Sung Kim, Hye-Mi Kim, Sang-Hoon Seo, Jaden Cha

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This International standard IEC 61508 sets out a generic approach for all safety lifecycle activities for systems comprised of electrical/electronic/programmable electronic (E/E/PE) elements that are used to perform safety functions. The control unit in stage control system is safety related facilities to control state and speed for stage system running, and it performs safety-critical function by stage control system. The controller unit is part of safety loops corresponding to the IEC 61508 and classified as logic part in the safety loop. In this paper, we analyze using FMEDA (Failure Mode Effect and Diagnostic Analysis) to verification for fault tolerance methods and functional safety of control unit. Moreover, we determined SIL (Safety Integrity Level) for control unit according to the safety requirements defined in IEC 61508-2 based on an analyzed functional safety.

Keywords: safety function, failure mode effect, IEC 61508-2, diagnostic analysis, stage control system

Procedia PDF Downloads 282
The Analysis of Priority Flood Control Management Using Analysis Hierarchy Process

Authors: Pravira Rizki Suwarno, Fanny Aliza Savitri, Priseyola Ayunda Prima, Pipin Surahman, Mahelga Levina Amran, Khoirunisa Ulya Nur Utari, Nora Permatasari

Abstract:

The Bogowonto River or commonly called the Bhagawanta River, is one of the rivers on Java Island. It is located in Central Java, Indonesia. Its watershed area is 35 km² with 57 km long. This river covers three regencies, namely Wonosobo Regency and Magelang Regency in the upstream and Purworejo Regency in the south and downstream. The Bogowonto River experiences channel narrowing and silting. It is caused by garbage along the river that comes from livestock and household waste. The narrowing channel and siltation cause a capacity reduction of the river to drain flood discharge. Comprehensive and sustainable actions are needed in dealing with current and future floods. Based on these current conditions, a priority scale is required. Therefore, this study aims to determine the priority scale of flood management in Purworejo Regency using the Analytical Hierarchy Process (AHP) method. This method will determine the appropriate actions based on the rating. In addition, there will be field observations through distributing questionnaires to several parties, including the stakeholders and the community. The results of this study will be in 2 (two) forms of actions, both structurally covering water structures and non-structural, including social, environmental, and law enforcement.

Keywords: analytical hierarchy process, bogowonto, flood control, management

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A Public Health Perspective on Deradicalisation: Re-Conceptualising Deradicalisation Approaches

Authors: Erin Lawlor

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In 2008 Time magazine named terrorist rehabilitation as one of the best ideas of the year. The term deradicalisation has become synonymous with rehabilitation within security discourse. The allure for a “quick fix” when managing terrorist populations (particularly within prisons) has led to a focus on prescriptive programmes where there is a distinct lack of exploration into the drivers for a person to disengage or deradicalise from violence. It has been argued that to tackle a snowballing issue that interventions have moved too quickly for both theory development and methodological structure. This overly quick acceptance of a term that lacks rigorous testing, measuring, and monitoring means that there is distinct lack of evidence base for deradicalisation being a genuine process/phenomenon, leading to academics retrospectively attempting to design frameworks and interventions around a concept that is not truly understood. The UK Home Office has openly acknowledged the lack of empirical data on this subject. This lack of evidence has a direct impact on policy and intervention development. Extremism and deradicalisation are issues that affect public health outcomes on a global scale, to the point that terrorism has now been added to the list of causes of trauma, both in the direct form of being victim of an attack but also the indirect context of witnesses, children and ordinary citizens who live in daily fear. This study critiques current deradicalisation discourses to establish whether public health approaches offer opportunities for development. The research begins by exploring the theoretical constructs of both what deradicalisation, and public health issues are. Questioning: What does deradicalisation involve? Is there an evidential base on which deradicalisation theory has established itself? What theory are public health interventions devised from? What does success look like in both fields? From establishing this base, current deradicalisation practices will then be explored through examples of work already being carried out. Critiques can be broken into discussion points of: Language, the difficulties with conducting empirical studies and the issues around outcome measurements that deradicalisation interventions face. This study argues that a public health approach towards deradicalisation offers the opportunity to attempt to bring clarity to the definitions of radicalisation, identify what could be modified through intervention and offer insights into the evaluation of interventions. As opposed to simply focusing on an element of deradicalisation and analysing that in isolation, a public health approach allows for what the literature has pointed out is missing, a comprehensive analysis of current interventions and information on creating efficacy monitoring systems. Interventions, policies, guidance, and practices in both the UK and Australia will be compared and contrasted, due to the joint nature of this research between Sheffield Hallam University and La Trobe, Melbourne.

Keywords: radicalisation, deradicalisation, violent extremism, public health

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Characteristics-Based Lq-Control of Cracking Reactor by Integral Reinforcement

Authors: Jana Abu Ahmada, Zaineb Mohamed, Ilyasse Aksikas

Abstract:

The linear quadratic control system of hyperbolic first order partial differential equations (PDEs) are presented. The aim of this research is to control chemical reactions. This is achieved by converting the PDEs system to ordinary differential equations (ODEs) using the method of characteristics to reduce the system to control it by using the integral reinforcement learning. The designed controller is applied to a catalytic cracking reactor. Background—Transport-Reaction systems cover a large chemical and bio-chemical processes. They are best described by nonlinear PDEs derived from mass and energy balances. As a main application to be considered in this work is the catalytic cracking reactor. Indeed, the cracking reactor is widely used to convert high-boiling, high-molecular weight hydrocarbon fractions of petroleum crude oils into more valuable gasoline, olefinic gases, and others. On the other hand, control of PDEs systems is an important and rich area of research. One of the main control techniques is feedback control. This type of control utilizes information coming from the system to correct its trajectories and drive it to a desired state. Moreover, feedback control rejects disturbances and reduces the variation effects on the plant parameters. Linear-quadratic control is a feedback control since the developed optimal input is expressed as feedback on the system state to exponentially stabilize and drive a linear plant to the steady-state while minimizing a cost criterion. The integral reinforcement learning policy iteration technique is a strong method that solves the linear quadratic regulator problem for continuous-time systems online in real time, using only partial information about the system dynamics (i.e. the drift dynamics A of the system need not be known), and without requiring measurements of the state derivative. This is, in effect, a direct (i.e. no system identification procedure is employed) adaptive control scheme for partially unknown linear systems that converges to the optimal control solution. Contribution—The goal of this research is to Develop a characteristics-based optimal controller for a class of hyperbolic PDEs and apply the developed controller to a catalytic cracking reactor model. In the first part, developing an algorithm to control a class of hyperbolic PDEs system will be investigated. The method of characteristics will be employed to convert the PDEs system into a system of ODEs. Then, the control problem will be solved along the characteristic curves. The reinforcement technique is implemented to find the state-feedback matrix. In the other half, applying the developed algorithm to the important application of a catalytic cracking reactor. The main objective is to use the inlet fraction of gas oil as a manipulated variable to drive the process state towards desired trajectories. The outcome of this challenging research would yield the potential to provide a significant technological innovation for the gas industries since the catalytic cracking reactor is one of the most important conversion processes in petroleum refineries.

Keywords: PDEs, reinforcement iteration, method of characteristics, riccati equation, cracking reactor

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The Effect of Gender Inequality on Reproductive Health in Africa: The Case of Cultural Ghana

Authors: Edna Roseline Dede Tetteh

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Reproductive health research and discussions have, over the years, placed a special focus on Africa. This is partly due to the significant relationship between African cultures and reproductive health. Several studies have also acknowledged the economic impact of reproductive health in Africa, because of which reproductive health, particularly family planning, has featured prominently in many economic discussions about Africa. Gender, which is a major element of most African cultures, inspired this study. Given that gender has a significant cultural influence in Africa, the study examined the effect of gender inequality on reproductive health in Africa, with a special focus on Ghana. Specifically, the study examined whether there exists any relationship between gender inequality and reproductive health and, if there is, what the nature and the effect of the relationship are. The study's findings were based on data gathered from 2304 respondents, randomly selected from Ghana's different tribes and ethnic groups. Given that the study was focused on the influence of gender in sexual relationships, the study’s population was people 16 years and above since 16 is the legal age of sexual consent in Ghana. Data was collected through questionnaires and interviews. It was found that the beliefs and practices of the traditional Ghanaian society, like most African societies, have direct and significant impacts on reproductive health. Males in these cultures have more control over reproductive health decisions and choices than females. The study found that it was culturally condemnable for a wife to refuse her husband’s request for sex, even when she is not in the mood for sex, or she is unwell. It was further found that, when it comes to the decision of birth control, males have more power. Consequently, females with reproductive health conditions have no control over choices that support their reproductive health conditions; they must always satisfy their husbands’ sexual needs. Most of the female respondents indicated they had less or no control over protecting themselves from reproductive health risks unless they had the understanding and support of their sexual partners.

Keywords: culture, gender, Ghana, inequality, reproductive health

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Towards Human-Interpretable, Automated Learning of Feedback Control for the Mixing Layer

Authors: Hao Li, Guy Y. Cornejo Maceda, Yiqing Li, Jianguo Tan, Marek Morzynski, Bernd R. Noack

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We propose an automated analysis of the flow control behaviour from an ensemble of control laws and associated time-resolved flow snapshots. The input may be the rich database of machine learning control (MLC) optimizing a feedback law for a cost function in the plant. The proposed methodology provides (1) insights into the control landscape, which maps control laws to performance, including extrema and ridge-lines, (2) a catalogue of representative flow states and their contribution to cost function for investigated control laws and (3) visualization of the dynamics. Key enablers are classification and feature extraction methods of machine learning. The analysis is successfully applied to the stabilization of a mixing layer with sensor-based feedback driving an upstream actuator. The fluctuation energy is reduced by 26%. The control replaces unforced Kelvin-Helmholtz vortices with subsequent vortex pairing by higher-frequency Kelvin-Helmholtz structures of lower energy. These efforts target a human interpretable, fully automated analysis of MLC identifying qualitatively different actuation regimes, distilling corresponding coherent structures, and developing a digital twin of the plant.

Keywords: machine learning control, mixing layer, feedback control, model-free control

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Electromagnetic Simulation Based on Drift and Diffusion Currents for Real-Time Systems

Authors: Alexander Norbach

Abstract:

The script in this paper describes the use of advanced simulation environment using electronic systems (Microcontroller, Operational Amplifiers, and FPGA). The simulation may be used for all dynamic systems with the diffusion and the ionisation behaviour also. By additionally required observer structure, the system works with parallel real-time simulation based on diffusion model and the state-space representation for other dynamics. The proposed deposited model may be used for electrodynamic effects, including ionising effects and eddy current distribution also. With the script and proposed method, it is possible to calculate the spatial distribution of the electromagnetic fields in real-time. For further purpose, the spatial temperature distribution may be used also. With upon system, the uncertainties, unknown initial states and disturbances may be determined. This provides the estimation of the more precise system states for the required system, and additionally, the estimation of the ionising disturbances that occur due to radiation effects. The results have shown that a system can be also developed and adopted specifically for space systems with the real-time calculation of the radiation effects only. Electronic systems can take damage caused by impacts with charged particle flux in space or radiation environment. In order to be able to react to these processes, it must be calculated within a shorter time that ionising radiation and dose is present. All available sensors shall be used to observe the spatial distributions. By measured value of size and known location of the sensors, the entire distribution can be calculated retroactively or more accurately. With the formation, the type of ionisation and the direct effect to the systems and thus possible prevent processes can be activated up to the shutdown. The results show possibilities to perform more qualitative and faster simulations independent of kind of systems space-systems and radiation environment also. The paper gives additionally an overview of the diffusion effects and their mechanisms. For the modelling and derivation of equations, the extended current equation is used. The size K represents the proposed charge density drifting vector. The extended diffusion equation was derived and shows the quantising character and has similar law like the Klein-Gordon equation. These kinds of PDE's (Partial Differential Equations) are analytically solvable by giving initial distribution conditions (Cauchy problem) and boundary conditions (Dirichlet boundary condition). For a simpler structure, a transfer function for B- and E- fields was analytically calculated. With known discretised responses g₁(k·Ts) and g₂(k·Ts), the electric current or voltage may be calculated using a convolution; g₁ is the direct function and g₂ is a recursive function. The analytical results are good enough for calculation of fields with diffusion effects. Within the scope of this work, a proposed model of the consideration of the electromagnetic diffusion effects of arbitrary current 'waveforms' has been developed. The advantage of the proposed calculation of diffusion is the real-time capability, which is not really possible with the FEM programs available today. It makes sense in the further course of research to use these methods and to investigate them thoroughly.

Keywords: advanced observer, electrodynamics, systems, diffusion, partial differential equations, solver

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Foreign Direct Investment and Its Impact on the Economic Growth of Emerging Economies: Does Ease of Doing Business Matter?

Authors: Mutaju Marobhe, Pastory Dickson

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This study explores the role of Foreign Direct Investment (FDI) in stimulating economic growth of emerging economies. FDIs have been associated with higher economic growth rates in developed countries due to the presence of conducive business conditions e.g. advanced financial markets which may accelerate the rate at which FDI boosts economic growth. So this study sets out to evaluate this macroeconomic phenomenon in emerging economies using the case study of Southern Africa Development Community (SADC) countries. The study uses Ease of Doing Business Index as a variable that moderates the relationship between FDI and economic growth. Panel data ranging from 2010 to 2019 from all SADC members are used and due to the unbalanced nature of the data, fixed effects regression analysis with moderation effect is used to assess this phenomenon. The conclusions and recommendations generated by this study will enable emerging economies to depict how they can be able to significantly improve FDI’s role in accelerating economic growth similarly to developed economies.

Keywords: ease of doing business, economic growth, emerging economies, foreign direct investment

Procedia PDF Downloads 150