Search results for: formal control

Authors: Ana Mouta, Ana Paulino

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The following text presents the ik.model, a theoretical framework that guided the pedagogical implementation of meaningful educational technology-based projects in formal education worldwide. In this paper, we will focus on how this framework has enabled the development of media literacy projects for early childhood education during the last three years. The methodology that guided educators through the challenge of systematically merging analogic and digital means in dialogic high-quality opportunities of world exploration is explained throughout these lines. The effects of this methodology on early age media literacy development are considered. Also considered is the relevance of this skill in terms of post-contemporary challenges posed to learning.

Keywords: early learning, ik.model, media literacy, pedagogy

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Authors: Mahmoud Jumah

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This paper presents the circumstances and decision making in case of change management in any industrial processes, and the effective strategic planning ensured to provide with the on time completion of projects. In this specific case, the Front End Engineering Design and the awarded Lump Sum Turn Key Contract had provided for full control and ownership of all Liquid Metering Skids by Controlling Team. The demarcation and location were changed, and the Ownership and Control of the Liquid Metering Skids inside the boundaries of the Asset Owner were transferred from Controlling Team to Asset Owner after the award of the LSTK Contract. The requested changes resulted in Adjustment Order and the relevant scope of work is an essential part of the original Contract. The majority of equipment and materials (i.e. liquid metering skids, valves, piping, etc.) has already been in process.

Keywords: critical path, project change management, stakeholders problem solving, strategic planning

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Authors: Jinshou Shi, Xiaozhou Zhou, Yingwei Zhou, Tuoyang Zhou, Ning Li, Chi Zhang, Zhanshuo Zhang, Ziang Chen

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In order to select the optimal interaction method for common computer click tasks, the click experiment test adopts the ISO 9241-9 task paradigm, using four common operations: mouse, trackball, touch, and eye control under visual feedback, auditory feedback, and no feedback. Through data analysis of various parameters of movement time, throughput, and accuracy, it is found that the movement time of touch-control is the shortest, the operation accuracy and throughput are higher than others, and the overall operation performance is the best. In addition, the motion time of the click operation with auditory feedback is significantly lower than the other two feedback methods in each operation mode experiment. In terms of the size of the click target, it is found that when the target is too small (less than 14px), the click performance of all aspects is reduced, so it is proposed that the design of the interface button should not be less than 28px. In this article, we discussed in detail the advantages and disadvantages of the operation and feedback methods, and the results of the discussion of the click operation can be applied to the design of the buttons in the interactive interface.

Keywords: cursor control performance, feedback, human computer interaction, throughput

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Authors: R. Gupta, P. Jain, S. Das

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One way to approach construction scheduling optimization problem is to focus on the individual aspects of planning, which can be broadly classified as time scheduling, crew and resource management, and cost control. During the last four decades, construction planning has seen a lot of research, but to date, no paper had attempted to summarize the literature available under important heads. This paper addresses each of aspects separately, and presents the findings of an in-depth literature of the various planning techniques. For techniques dealing with time scheduling, the authors have adopted a rough chronological documentation. For crew and resource management, classification has been done on the basis of the different steps involved in the resource planning process. For cost control, techniques dealing with both estimation of costs and the subsequent optimization of costs have been dealt with separately.

Keywords: construction planning techniques, time scheduling, resource planning, cost control

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Authors: Mohammadreza Heydariazad

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Productivity growth of wind energy as a clean source needed to achieve improved strategy in production and transmission and management of wind resources in order to increase quality of power and reduce costs. New technologies based on power converters that cause changing turbine speed to suit the wind speed blowing turbine improve extraction efficiency power from wind. This article introduces variable speed wind turbines and optimization of power, and presented methods to use superconducting inductor in the composition of power converter and is proposed the dc measurement for the wind farm and especially is considered techniques available to them. In fact, this article reviews mechanisms and function, changes of wind speed turbine according to speed control strategies of various types of wind turbines and examines power possible transmission and ac from producing location to suitable location for a strong connection integrating wind farm generators, without additional cost or equipment. It also covers main objectives of the dynamic control of wind turbines, and the methods of exploitation and the ways of using it that includes the unique process of these components. Effective algorithm is presented for power control in order to extract maximum active power and maintains power factor at the desired value.

Keywords: wind energy, generator, superconducting inductor, wind turbine power

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Authors: N. J. M. Yusof, T. Sabir, J. McLoughlin

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Garment manufacturing industry involves sequential processes that are subjected to uncontrollable variations. The industry depends on the skill of labour in handling the varieties of fabrics and accessories, machines, and also a complicated sewing operation. Due to these reasons, garment manufacturers created systems to monitor and control the product’s quality regularly by conducting quality approaches to minimize variation. The aims of this research were to ascertain the quality approaches deployed by Malaysian garment manufacturers in three key areas-quality systems and tools; quality control and types of inspection; sampling procedures chosen for garment inspection. The focus of this research also aimed to distinguish quality approaches used by companies that supplied the finished garments to both domestic and international markets. The feedback from each of company’s representatives was obtained using the online survey, which comprised of five sections and 44 questions on the organizational profile and quality approaches used in the garment industry. The results revealed that almost all companies had established their own mechanism of process control by conducting a series of quality inspection for daily production either it was formally been set up or vice versa. Quality inspection was the predominant quality control activity in the garment manufacturing and the level of complexity of these activities was substantially dictated by the customers. AQL-based sampling was utilized by companies dealing with the export market, whilst almost all the companies that only concentrated on the domestic market were comfortable using their own sampling procedures for garment inspection. This research provides an insight into the implementation of quality approaches that were perceived as important and useful in the garment manufacturing sector, which is truly labour-intensive.

Keywords: garment manufacturing, quality approaches, quality control, inspection, Acceptance Quality Limit (AQL), sampling

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Authors: Anh Duc Dang, Joachim Horn

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This paper presents a new approach to control robots, which can quickly find their swarm while tracking a moving target through the obstacles of the environment. In this approach, an artificial potential field is generated between each free-robot and the virtual attractive point of the swarm. This artificial potential field will lead free-robots to their swarm. The swarm-finding of these free-robots dose not influence the general motion of their swarm and nor other robots. When one singular robot approaches the swarm then its swarm-search will finish, and it will further participate with its swarm to reach the position of the target. The connections between member-robots with their neighbours are controlled by the artificial attractive/repulsive force field between them to avoid collisions and keep the constant distances between them in ordered formation. The effectiveness of the proposed approach has been verified in simulations.

Keywords: formation control, potential field method, obstacle avoidance, swarm intelligence, multi-agent systems

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Authors: Abdul G. Miah, Hirotada Tsujii, Ummay Salma, Iwao Takeda

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The study was designed to investigate the effects of dietary Selenium-enriched radish sprouts (Se-RS), Vitamin E (Vit E) and Rhodobacter capsulatus (RC) on broiler's immunity, cholesterol concentration and fatty acid composition in broiler meat. A total of 100 two-week-old male broiler chicks were randomly assigned into 5 dietary groups, such as i) Control; ii) Se-RS (5 μg/kg Se-RS); iii) Se-RS+RC (5 μg/kg Se-RS + 0.2 g/kg RC); iv) Se-RS+Vit E (5 μg/kg Se-RS + 50 mg/kg Vit E) and v) Se-RS+RC+Vit E (5 μg/kg Se-RS + 0.2 g/kg RC + 50 mg/kg Vit E). The broilers were offered ad libitum specific diets and clean drinking water. After the end of 3-wk of feeding period, serum cholesterol and triglycerides concentrations were decreased (p<0.05) specially, in the broilers fed Se-RS+RC+Vit E supplemented diet compared to the broilers fed control diet. At the end of the 6-wk feeding period, Se-RS+RC+Vit E supplemented diet significantly (p<0.05) reduced cholesterol and triglycerides concentrations, and improved the ratio of unsaturated fatty acids (UFA) to saturated fatty acids (SFA) in broiler meat. The highest (p<0.05) number of leukocytes was observed in the broilers fed Se-RS+RC+Vit E supplemented diet than that of the broilers fed control diet. Spleen, bursa and thymus weight were significantly (p<0.05) increased by Se-RS+RC+Vit E supplemented diet than the control diet. Compared to the control diet, Se-RS+RC+Vit E supplemented diet significantly (p<0.05) increased foot web index. Moreover, there was no mortality in all groups of broilers during the experimental period. Therefore, the study may conclude that there are dual benefits of Se-RS+RC+Vit E supplementation in broiler diet improved immunity and meat quality for health conscious consumers.

Keywords: hypocholesterolemia, immunity of broiler, rhodobacter capsulatus, selenium-enriched radish sprouts, vitamin E

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Authors: D. S. Naumann, B. J. Evans, O. Hassan

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This paper outlines the development of an automated aerodynamic optimisation algorithm using a novel method of parameterising a computational mesh by employing user–defined control nodes. The shape boundary movement is coupled to the movement of the novel concept of the control nodes via a quasi-1D-linear deformation. Additionally, a second order smoothing step has been integrated to act on the boundary during the mesh movement based on the change in its second derivative. This allows for both linear and non-linear shape transformations dependent on the preference of the user. The domain mesh movement is then coupled to the shape boundary movement via a Delaunay graph mapping. A Modified Cuckoo Search (MCS) algorithm is used for optimisation within the prescribed design space defined by the allowed range of control node displacement. A finite volume compressible NavierStokes solver is used for aerodynamic modelling to predict aerodynamic design fitness. The resulting coupled algorithm is applied to a range of test cases in two dimensions including the design of a subsonic, transonic and supersonic intake and the optimisation approach is compared with more conventional optimisation strategies. Ultimately, the algorithm is tested on a three dimensional wing optimisation case.

Keywords: mesh movement, aerodynamic shape optimization, cuckoo search, shape parameterisation

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Authors: Numra Qayyum, Samina Sarwat, Noor ul Ain

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Bilingual speakers generally can speak both languages with the same competency without mixing them intentionally and making mistakes, but sometimes errors occur in language selection. This quantitative study particularly deals with the language errors made by Urdu-English bilinguals. In this research, researchers have given special attention to the part played by bottom-up priming and top-down cognitive control in these errors. Unstable Urdu-English bilingual participants termed pictures and were prompted to shift from one language to another under the pressure of time. Different situations were given to manipulate the participants. The long and short runs trials of the same language were also given before switching to another language. The study is concluded with the findings that bilinguals made more errors when switching to the first language from their second language, and these errors are large in number, especially when a speaker is switching from L2 (second language) to L1 (first language) after a long run. When the switching is reversed, i.e., from L2 to LI, it had no effect at all. These results gave the clear responsibility of all these errors to top-down cognitive control.

Keywords: bottom up priming, language error, language switching, top down cognitive control

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Authors: Mehrdad Mahmudizad, Roya Ahmadi Ahangar

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This paper presents the method of designing the type 2 fuzzy PID controllers in order to solve the problem of Load Frequency Control (LFC). The Harmony Search (HS) algorithm is used to regulate the measurement factors and the effect of uncertainty of membership functions of Interval Type 2 Fuzzy Proportional Integral Differential (IT2FPID) controllers in order to reduce the frequency deviation resulted from the load oscillations. The simulation results implicitly show that the performance of the proposed IT2FPID LFC in terms of error, settling time and resistance against different load oscillations is more appropriate and preferred than PID and Type 1 Fuzzy Proportional Integral Differential (T1FPID) controllers.

Keywords: load frequency control, fuzzy-pid controller, type 2 fuzzy system, harmony search algorithm

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Authors: Feddaoui Amina

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In a broad sense, corporate governance covers the organization of the control and management. The term is also used in a narrower sense, to refer to the relationship between shareholders, and the company’s board. There are a lot of discussions devoted to the understanding of the corporate governance role and its principles. In this paper, we are going to describe the definition of corporate governance as a control system and its principles, and find the role of corporate governance and its pillars. Finally, we are going to drop the theoretical study on the case of Japan.

Keywords: corporate governance, place, role, Japan

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Authors: Mahmoud Mohammad Salem Al-Suod, Ushkarenko O. Alexander, Dorogan I. Olga

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New algorithms using microprocessor systems have been proposed for protection the diesel-generator unit in autonomous power systems. The software structure is designed to enhance the control automata of the system, in which every protection module of diesel-generator encapsulates the finite state machine.

Keywords: diesel-generator unit, protection, state diagram, control system, algorithm, software components

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Authors: H. Mekki, A. Djerioui, S. Zeghlache, L. Chrifi-Alaoui

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Induction motor (IM)Induction motor (IM) are nowadays widely used in industrial applications specially in electric vehicles (EVs) and traction locomotives, due to their high efficiency high speed and lifetime. However, since EV motors are easily influenced by un-certainties parameter variations and external load disturbance, both robust control techniques have received considerable attention during the past few decades. This paper present a robust controller design based sliding mode control (SMC) and high gain flux observer (HGO) for induction motor (IM) based Electric Vehicles (EV) drives. This control technique is obtained by the combination between the field oriented and the sliding mode control strategy and present remarkable dynamic performances just as a good robustness with respect to EV drives load torque. A high gain flux observer is also presented and associated in order to design sensorless control by estimating the rotor flux only using measurements of the stator voltages and currents. Simulations results are provided to evaluate the consistency and to show the effectiveness of the proposed SMC strategy also the performance of the HGO for Electric Vehicles system are nowadays widely used in industrial applications specially in electric vehicles (EVs) and traction locomotives, due to their high efficiency high speed and lifetime. However, since EV motors are easily influenced by un-certainties parameter variations and external load disturbance, both robust control techniques have received considerable attention during the past few decades. This paper present a robust controller design based sliding mode control (SMC) and high gain flux observer (HGO) for induction motor (IM) based Electric Vehicles (EV) drives. This control technique is obtained by the combination between the field oriented and the sliding mode control strategy and present remarkable dynamic performances just as a good robustness with respect to EV drives load torque. A high gain flux observer is also presented and associated in order to design sensorless control by estimating the rotor flux only using measurements of the stator voltages and currents. Simulations results are provided to evaluate the consistency and to show the effectiveness of the proposed SMC strategy also the performance of the HGO for Electric Vehicles system.

Keywords: electric vehicles, sliding mode control, induction motor drive, high gain observer

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Authors: Julian Thrash, Douglas Folk, Michael Ciracy, Audrey C. Tseng, Kristen M. Stromsodt, Amber Younggren, Christopher Maciolek

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The cardiopulmonary system is comprised of the heart, lungs, and many dynamic feedback mechanisms that control its function based on a multitude of variables. The next generation of cardiopulmonary medical devices will involve adaptive control and smart pacing techniques. However, testing these smart devices on living systems may be unethical and exceedingly expensive. As a solution, a comprehensive computational model of the cardiopulmonary system was implemented in Simulink. The model contains over 240 state variables and over 100 equations previously described in a series of published articles. Simulink was chosen because of its ease of introducing machine learning elements. Initial results indicate that physiologically correct waveforms of pressures and volumes were obtained in the simulation. With the development of a comprehensive computational model, we hope to pioneer the future of predictive medicine by applying our research towards the initial stages of smart devices. After validation, we will introduce and train reinforcement learning agents using the cardiopulmonary model to assist in adaptive control system design. With our cardiopulmonary model, we will accelerate the design and testing of smart and adaptive medical devices to better serve those with cardiovascular disease.

Keywords: adaptive control, cardiopulmonary, computational model, machine learning, predictive medicine

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Authors: Pramote Thangkratok

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The aims of this experimental study were to investigate the effect of Reverse Trendelenburg Position on the Back Pain after Cardiovascular Angiography and Interventions. In addition, to compare bleeding and hematoma occurrences at the Access site between experimental and control groups. The randomized controlled trial (RCT) was conducted in 70 patients who underwent Cardiovascular Angiography and Interventions via the femoral artery and received post procedural care at the intermediate cardiac care unit, Bangkok Heart Hospital. From December 2015 to February 2016. The control group (35 patients) was to get standard care after the intervention, whereas the experimental group (35 patients) was Reverse Trendelenburg Position 30-45 degrees. The groups were not significantly different in terms of demographic characteristics, Age, Gender, BMI, blood pressure, heart rate. While not significantly different from each other, the intensity of back pain control group had a significantly higher pain score than experimental group. Vascular complications in terms of bleeding and hematoma were not significantly different between the control and experimental groups. The findings show that Reverse Trendelenburg Position after Cardiovascular Angiography and Interventions would reduce or prevent the back pain without increasing the chance of bleeding and hematoma.

Keywords: reverse trendelenburg position, back pain, cardiovascular angiography, cardiovascular interventions

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Authors: Jo-Ann Müller

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The integration-responsiveness (IR) framework presents four distinct internationalization strategies which differ depending on the extent of pressure the company faces for local responsiveness and global integration. This study applies the framework to standards by examining differences in the relative importance of three types of standards depending on the role the subsidiary plays within the corporate group. Hypotheses are tested empirically in a two-stage procedure. First, the subsidiaries are grouped performing cluster analysis. In the second step, the relationship between cluster affiliation and subsidiary strategy is tested using multinomial Probit estimation. While the level of local responsiveness of a firm relates to the relative importance of national and international formal standards, the degree of vertical integration is associated with the application of internal company.

Keywords: FDI, firm-level data, standards, subsidiary strategy

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Authors: Pawel Martynowicz

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Vibrations are a crucial problem for slender structures such as towers, masts, chimneys, wind turbines, bridges, high buildings, etc., that is why most of them are equipped with vibration attenuation or fatigue reduction solutions. In this work, a slender structure (i.e., wind turbine tower-nacelle model) equipped with nonlinear, semiactive tuned vibration absorber(s) is analyzed. For this study purposes, magnetorheological (MR) dampers are used as semiactive actuators. Several optimal-based approaches to structural vibration attenuation are investigated against the standard ‘ground-hook’ law and passive tuned vibration absorber(s) implementations. The common approach to optimal control of nonlinear systems is offline computation of the optimal solution, however, so determined open loop control suffers from lack of robustness to uncertainties (e.g., unmodelled dynamics, perturbations of external forces or initial conditions), and thus perturbation control techniques are often used. However, proper linearization may be an issue for highly nonlinear systems with implicit relations between state, co-state, and control. The main contribution of the author is the development as well as numerical and experimental verification of the Pontriagin maximum-principle-based vibration control concepts that produce directly actuator control input (not the demanded force), thus force tracking algorithm that results in control inaccuracy is entirely omitted. These concepts, including one-step optimal control, quasi-optimal control, and optimal-based modified ‘ground-hook’ law, can be directly implemented in online and real-time feedback control for periodic (or semi-periodic) disturbances with invariant or time-varying parameters, as well as for non-periodic, transient or random disturbances, what is a limitation for some other known solutions. No offline calculation, excitations/disturbances assumption or vibration frequency determination is necessary, moreover, all of the nonlinear actuator (MR damper) force constraints, i.e., no active forces, lower and upper saturation limits, hysteresis-type dynamics, etc., are embedded in the control technique, thus the solution is optimal or suboptimal for the assumed actuator, respecting its limitations. Depending on the selected method variant, a moderate or decisive reduction in the computational load is possible compared to other methods of nonlinear optimal control, while assuring the quality and robustness of the vibration reduction system, as well as considering multi-pronged operational aspects, such as possible minimization of the amplitude of the deflection and acceleration of the vibrating structure, its potential and/or kinetic energy, required actuator force, control input (e.g. electric current in the MR damper coil) and/or stroke amplitude. The developed solutions are characterized by high vibration reduction efficiency – the obtained maximum values of the dynamic amplification factor are close to 2.0, while for the best of the passive systems, these values exceed 3.5.

Keywords: magnetorheological damper, nonlinear tuned vibration absorber, optimal control, real-time structural vibration attenuation, wind turbines

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Authors: Abdolghader Pourali, Mohammad V. Malakooti, Muhammad Hussein Yektaie

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A mobile payment system in mobile e-commerce generally have high security so that the user can trust it for doing business deals, sales, paying financial transactions, etc. in the mobile payment system. Since an architecture or payment model in e-commerce only shows the way of interaction and collaboration among users and mortgagers and does not present any evaluation of effectiveness and confidence about financial transactions to stakeholders. In this paper, we try to present a detailed assessment of the reliability of a mobile payment model in the mobile e-commerce using formal models and colored Petri nets. Finally, we demonstrate that the reliability of this system has high value (case study: a secure payment model in mobile commerce.

Keywords: reliability, colored Petri net, assessment, payment models, m-commerce

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Authors: Prateek Bhattacharya

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The definition of 'control' in India is a rapidly evolving concept, owing to varying rights attached to varying securities. Shares with differential voting rights (DVRs) provide the holder with differential rights as to voting, as compared to ordinary equity shareholders of the company. Such DVRs can amount to both superior voting rights and inferior voting rights, where DVRs with superior voting rights amount to providing the holder with golden shares in the company. While DVRs are not a novel concept in India having been recognized since 2000, they were placed on a back burner by the Securities and Exchange Board of India (SEBI) in 2010 after issuance of DVRs with superior voting rights was restricted. In June 2019, the SEBI rekindled the ebbing fire of DVRs, keeping mind the fast-paced nature of the global economy, the government's faith that India’s ‘new age technology companies’ (i.e., Start-Ups) will lead the charge in achieving its goal of India becoming a $5 trillion dollar economy by 2024, and recognizing that the promoters of such Start-Ups seek to raise capital without losing control over their companies. DVRs with superior voting rights guarantee promoters with up to 74% shareholding in Start-Ups for a period of 5 years, meaning that the holder of such DVRs can exercise sole control and material influence over the company for that period. This manner of control has the potential of causing both pro-competitive and anti-competitive effects in the markets where these companies operate. On the one hand, DVRs will allow Start-Up promoters/founders to retain control of their companies and protect its business interests from foreign elements such as private/public investors – in a scenario where such investors have multiple investments in firms engaged in associated lines of business (whether on a horizontal or vertical level) and would seek to influence these firms to enter into potential anti-competitive arrangements with one another, DVRs will enable the promoters to thwart such scenarios. On the other hand, promoters/founders who themselves have multiple investments in Start-Ups, which are in associated lines of business run the risk of influencing these associated Start-Ups to engage in potentially anti-competitive arrangements in the name of profit maximisation. This paper shall be divided into three parts: Part I shall deal with the concept of ‘control’, as deliberated upon and decided by the SEBI and the Competition Commission of India (CCI) under both company/securities law and competition law; Part II shall review this definition of ‘control’ through the lens of DVRs, and Part III shall discuss the aforementioned potential pro-competitive and anti-competitive effects caused by the DVRs by examining the current Indian Start-Up scenario. The paper shall conclude by providing suggestions for the CCI to incorporate a clearer and more progressive concept of ‘control’.

Keywords: competition law, competitive effects, control, differential voting rights, DVRs, investor shareholding, merger control, start-ups

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Authors: Aniket Aaba Kadam, Manish Mangesh Panchal, Roushan Ashit Sharma

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This project focuses on the design and development of a lab-scale hybrid rocket motor to accurately determine the regression rate of a fuel/oxidizer combination consisting of solid paraffin and gaseous oxygen (GOX). Hybrid motors offer the advantage of on-demand thrust control over both solid and liquid systems in certain applications. The thermodynamic properties of the propellant combination were calculated using NASA CEA at different chamber pressures and corresponding O/F values to determine initial operating conditions with suitable peak temperatures and optimal O/F values. The project also includes the design of the injector orifice and the determination of the final design configurations of the motor casing, pressure control setup, and valve configuration. This research will be valuable in advancing the understanding of paraffin-based propulsion and improving the performance of hybrid rocket motors.

Keywords: hybrid rocket, NASA CEA, injector, thrust control

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Authors: Y. Kobori, S. Tanaka, N. Tsukiji, N. Takai, H. Kobayashi

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This paper proposes two kinds of new single-inductor dual-output (SIDO) DC-DC switching converters with ripple-based hysteretic control. First SIDO converters of type 1 utilize the triangular signal generated by the CR-circuit connected across the inductor. This triangular signal is used for generating the PWM signal instead of the saw-tooth signal used in the conventional converters. Second SIDO converters of type 2 utilize the triangular signal generated by the CR-circuit connected across the voltage error amplifier. This paper describes circuit topologies, Operation principles, simulation results and experimental results of the proposed SIDO converters. In simulation results of both type of SIDO converters, static output voltage ripples are less than 5mVpp and over/under shoots of the dynamic load regulations for the output current step are less than +/- 10mV. In experimental results of single output converter of type 2, static output voltage ripples are about 20mVpp. Output ripples of SIDO type 1 converter are about 80mVpp.

Keywords: DC-DC converter, switching converter, SIDO converter, hysteretic control, ripple-based control

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Authors: Ziraguen O. Williams, Shield B. Lin, Fouad N. Matari, Leslie J. Quiocho

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Simulation for seated row exercise was a continued task to assist NASA in analyzing a one-dimensional vibration isolation and stabilization system for astronaut’s exercise platform. Feedback delay and signal noise were added to the model as previously done in simulation for squat exercise. Simulation runs for this study were conducted in two software simulation tools, Trick and MBDyn, software simulation environments developed at the NASA Johnson Space Center. The exciter force in the simulation was calculated from the motion capture of an exerciser during a seated row exercise. The simulation runs include passive control, active control using a Proportional, Integral, Derivative (PID) controller, and active control using a Piecewise Linear Integral Derivative (PWLID) controller. Output parameters include displacements of the exercise platform, the exerciser, and the counterweight; transmitted force to the wall of spacecraft; and actuator force to the platform. The simulation results showed excellent force reduction in the actively controlled system compared to the passive controlled system, which showed less force reduction.

Keywords: control, counterweight, isolation, vibration.

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Authors: Rahul Ganpat Mapari, D. G. Wakde

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In this paper, a proposed approach to improve the power factor of single-phase rectifiers and to regulate the output voltage against the change in grid voltage and load is presented. This converter topology is evaluated on the basis of performance and its salient features like simplicity, low cost and high performance are discussed to analyze its applicability. The proposed control strategy is bridgeless, transformer-less and output current sensor-less and consists of only two Bi-directional IGBTs and two diodes. The voltage regulation is achieved by a simple voltage divider to communicate to a controller to control the duty cycles of PWM. A control technique and operational procedure are also developed, both theoretically and experimentally. The experimental results clearly verify the theoretical analysis from the prototype connected to grid unity.

Keywords: Active Rectifier (AC-DC), power factor, single phase, voltage regulation

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Authors: Cristina Nieves Perdomo Delgado

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The study consists of the design and use of an application for cell phones called “Me Cuido” that consists of remote control of elderly people who live alone with their families. The objective of the study is to analyze the usability of the application by 40-year-olds using the Questionnaire for User Interaction Satisfaction (QUIS) method. The results highlight that the application has a design adapted to the elderly and that it is easy to use and understand.

Keywords: design, assistive technology, elderly people, independence

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Authors: Vasiliki Stratidou

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Modern simulation mobile games have the potential to enhance students’ interest, motivation and creativity. Research conducted on the effectiveness of digital games for educational purposes has shown that such games are also ideal at providing an appropriate environment for language learning. The paper examines the issue of simulation mobile games in regard to the potential positive impacts on L2 vocabulary learning. Sixteen intermediate level students, aged 10-14, participated in the experimental study for four weeks. The participants were divided into experimental (8 participants) and control group (8 participants). The experimental group was planned to learn some new vocabulary words via digital games while the control group used a reading passage to learn the same vocabulary words. The study investigated the effect of mobile games as well as the traditional learning methods on Greek EFL learners’ vocabulary learning in a pre-test, an immediate post-test, and a two-week delayed retention test. A teacher’s diary and learners’ interviews were also used as tools to estimate the effectiveness of the implementation. The findings indicated that the experimental group outperformed the control group in acquiring new words through mobile games. Therefore, digital games proved to be an effective tool in learning English vocabulary.

Keywords: control group, digital games, experimental group, second language vocabulary learning, simulation games

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Authors: Seyed Mohammad Hashemi, Shahrokh Barati

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The problem of fault-tolerant control (FTC) by accommodation method has been studied in this paper. The fault occurs in any system components such as actuators, sensors or internal structure of the system and leads to loss of performance and instability of the system. When a fault occurs, the purpose of the fault-tolerant control is designate strategy that can keep the control loop stable and system performance as much as possible perform it without shutting down the system. Here, the section of fault detection and isolation (FDI) system has been evaluated with regard to actuator's fault. Designing a fault detection and isolation system for a multi input-multi output (MIMO) is done by an unknown input observer, so the system is divided to several subsystems as the effect of other inputs such as disturbing given system state equations. In this observer design method, the effect of these disturbances will weaken and the only fault is detected on specific input. The results of this approach simulation can confirm the ability of the fault detection and isolation system design. After fault detection and isolation, it is necessary to redesign controller based on a suitable modification. In this regard after the use of unknown input observer theory and obtain residual signal and evaluate it, PID controller parameters redesigned for iterative. Stability of the closed loop system has proved in the presence of this method. Also, In order to soften the volatility caused by Annie variations of the PID controller parameters, modifying Sigma as a way acceptable solution used. Finally, the simulation results of three tank popular example confirm the accuracy of performance.

Keywords: fault tolerant control, fault detection and isolation, actuator fault, unknown input observer

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Authors: Ji Xi, Cheng Song Chin, Ehsan Mesbahi

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Structure-borne noise is an important aspect of offshore platform sound field. It can be generated either directly by vibrating machineries induced mechanical force, indirectly by the excitation of structure or excitation by incident airborne noise. Therefore, limiting of the transmission of vibration energy throughout the offshore platform is the key to control the structure-borne noise. This is usually done by introducing damping treatment to the steel structures. Two types of damping treatment using on-board are presented. By conducting a statistical energy analysis (SEA) simulation on a jack-up rig, the noise level in the source room, the neighboring rooms, and remote living quarter cabins are compared before and after the damping treatments been applied. The results demonstrated that, in the source neighboring room and living quarter area, there is a significant noise reduction with the damping treatment applied, whereas in the source room where air-borne sound predominates that of structure-borne sound, the impact is not obvious. The subsequent optimization design of damping treatment in the offshore platform can be made which enable acoustic professionals to implement noise control during the design stage for offshore crews’ hearing protection and habitant comfortability.

Keywords: statistical energy analysis, damping treatment, noise control, offshore platform

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Authors: Calvin Rong, Regina Agassian, Mindy Engle-Friedman

Abstract:

Climate changes, including rising sea levels and increases in global temperature, can have major effects on resource availability, leading to increased competition for resources and rising food prices. The abstract nature and often delayed consequences of many ecological problems cause people focus on immediate, specific, and personal events and circumstances that compel immediate and emotional involvement. This finding may be explained by the challenges humans have in imagining themselves in the future, a shortcoming that interferes with decision-making involving far-off rewards, and leads people to indicate a lower concern toward the future than to present circumstances. The present study sought to assess whether priming people to think of themselves in the future might strengthen the connection to their future selves and stimulate environmentally-protective behavior. We hypothesize that priming participants to think about themselves in the future would increase concern for the future environment. 45 control participants were primed to think about themselves in the present, and 42 participants were primed to think about themselves in the futures. After priming, the participants rated their concern over access to clean water, food, and energy on a scale of 1 to 10. They also rated their predicted care levels for the environment at age points 40, 50, 60, 70, 80, and 90 on a scale of 1(not at all) to 10 (very much). Predicted care levels at age 90 for the experimental group was significantly higher than for the control group. Overall the experimental group rated their concern for resources higher than the control. In comparison to the control group (M=7.60, SD=2.104) participants in the experimental group had greater concern for clean water (M=8.56, SD=1.534). In comparison to the control group (M=7.49, SD=2.041) participants in the experimental group were more concerned about food resources (M=8.41, SD=1.830). In comparison to the control group (M=7.22, SD=1.999) participants in the experimental group were more concerned about energy resources (M=8.07, SD=1.967). This study assessed whether a priming strategy could be used to encourage pro-environmental practices that protect limited resources. Future-self priming helped participants see past short term issues and focus on concern for the future environment.

Keywords: climate change, future, priming, global warming

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Authors: Aziz Sezgin

Abstract:

We consider the problem of stabilization of an unstable heat equation in a 2-D, 3-D and generally n-D domain by deriving a generalized backstepping boundary control design methodology. To stabilize the systems, we design boundary backstepping controllers inspired by the 1-D unstable heat equation stabilization procedure. We assume that one side of the boundary is hinged and the other side is controlled for each direction of the domain. Thus, controllers act on two boundaries for 2-D domain, three boundaries for 3-D domain and ”n” boundaries for n-D domain. The main idea of the design is to derive ”n” controllers for each of the dimensions by using ”n” kernel functions. Thus, we obtain ”n” controllers for the ”n” dimensional case. We use a transformation to change the system into an exponentially stable ”n” dimensional heat equation. The transformation used in this paper is a generalized Volterra/Fredholm type with ”n” kernel functions for n-D domain instead of the one kernel function of 1-D design.

Keywords: backstepping, boundary control, 2-D, 3-D, n-D heat equation, distributed parameter systems

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