Search results for: port state control
16721 Pose-Dependency of Machine Tool Structures: Appearance, Consequences, and Challenges for Lightweight Large-Scale Machines
Authors: S. Apprich, F. Wulle, A. Lechler, A. Pott, A. Verl
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Large-scale machine tools for the manufacturing of large work pieces, e.g. blades, casings or gears for wind turbines, feature pose-dependent dynamic behavior. Small structural damping coefficients lead to long decay times for structural vibrations that have negative impacts on the production process. Typically, these vibrations are handled by increasing the stiffness of the structure by adding mass. That is counterproductive to the needs of sustainable manufacturing as it leads to higher resource consumption both in material and in energy. Recent research activities have led to higher resource efficiency by radical mass reduction that rely on control-integrated active vibration avoidance and damping methods. These control methods depend on information describing the dynamic behavior of the controlled machine tools in order to tune the avoidance or reduction method parameters according to the current state of the machine. The paper presents the appearance, consequences and challenges of the pose-dependent dynamic behavior of lightweight large-scale machine tool structures in production. The paper starts with the theoretical introduction of the challenges of lightweight machine tool structures resulting from reduced stiffness. The statement of the pose-dependent dynamic behavior is corroborated by the results of the experimental modal analysis of a lightweight test structure. Afterwards, the consequences of the pose-dependent dynamic behavior of lightweight machine tool structures for the use of active control and vibration reduction methods are explained. Based on the state of the art on pose-dependent dynamic machine tool models and the modal investigation of an FE-model of the lightweight test structure, the criteria for a pose-dependent model for use in vibration reduction are derived. The description of the approach for a general pose-dependent model of the dynamic behavior of large lightweight machine tools that provides the necessary input to the aforementioned vibration avoidance and reduction methods to properly tackle machine vibrations is the outlook of the paper.Keywords: dynamic behavior, lightweight, machine tool, pose-dependency
Procedia PDF Downloads 45916720 Strategies Considered Effective for Funding Public Tertiary Institutions in Nigeria
Authors: Jacinta Ifeoma Obidile
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The study sought to ascertain from the opinions of the business educators, effective strategies for funding public tertiary institutions in Anambra State Nigeria, for effective functioning and delivery. Funding of tertiary institutions has become so important following the dilapidated state of most of the public tertiary institutions in Nigeria. Tertiary institutions are known for the production of competitive and competent workforce in the nation. Considering the state of public tertiary institutions currently, one wonders if their objectives are achieved. Many scholars have identified funding as one of the major barriers to effective functioning of tertiary institutions. Although federal and state governments have been supporting the tertiary institutions, but their support seems not to be adequate. This study therefore ascertained from the perspective of business educators, other strategies for funding public tertiary institutions in Anambra State Nigeria, for effective functioning and delivery. Survey research design was adopted for the study. A total of 104 business educators from the public tertiary institutions in the State constituted the population. There was no sampling, hence the whole population was used. Structured questionnaire validated by three experts with a reliability coefficient of 0.82 was the instrument for data collection. Data collected were analyzed using mean and standard deviation. Findings from the study revealed that public-private partnership and external aids were among the strategies considered effective for funding public tertiary institutions. It was therefore recommended among others that associations like alumni should be strongly instituted in each of the public tertiary institutions so as to assist in the funding of tertiary institutions for effective functioning and delivery.Keywords: strategies, funding, tertiary institutions, business educators
Procedia PDF Downloads 15516719 Real-Time Control of Grid-Connected Inverter Based on labVIEW
Authors: L. Benbaouche, H. E. , F. Krim
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In this paper we propose real-time control of grid-connected single phase inverter, which is flexible and efficient. The first step is devoted to the study and design of the controller through simulation, conducted by the LabVIEW software on the computer 'host'. The second step is running the application from PXI 'target'. LabVIEW software, combined with NI-DAQmx, gives the tools to easily build applications using the digital to analog converter to generate the PWM control signals. Experimental results show that the effectiveness of LabVIEW software applied to power electronics.Keywords: real-time control, labview, inverter, PWM
Procedia PDF Downloads 50916718 The Effectiveness of Psychodrama on Self-esteem Enhancement in Adolescent Boys
Authors: Saeed Dehnavi, Zahra Dehnavi
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Background: Psychodrama, as a form of art therapy, helps people to enact and use role-plays for a specific problem, rather than just talking about it, in an effort to review the problem, gain feedback from group members, find appropriate solutions, and practice them for their life. This paper evaluated the effectiveness of psychodrama on enhancing self-esteem of young adolescent boys. Methodology: This is aquasi-experimental research study, using a pre-post testing plan with control group.From four secondary schools in Kermanshah – Iran, 210 adolescent boys (aged 13 and 14 years) were asked to complete Koper Smith's self-esteem measure scale. Given the low self-esteem scores (less than the cut-off of 23), a number of 20 individuals were selected and randomly placed into two control and experimental groups. The experimental group participated in a twelve-session psychodrama therapy plan for 6 weeks, while the control group received no intervention. Data analysis was carried out by the analysis of covariance (ANCOVA). Results: The results of ANCOVA analysis showed an increase in the post-test scores for self-esteem, and such increase was statistically significant. Conclusion: The findings indicated the effectiveness of psychodrama on self-esteem enhancement of young boys. During psychodrama sessions, the adolescents learned to take the initiative, communicate with others in an excited state, and improve their self-esteem with positive and constructive experiences.Keywords: psychodrama, self-esteem, young adolescents, boys
Procedia PDF Downloads 48016717 Mechanisms and Process of an Effective Public Policy Formulation in Islamic Economic System
Authors: Md Abu Saieed
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Crafting and implementing public policy is one of the indispensable works in any form of state and government. But the policy objectives, methods of formulation and tools of implementation might be different based on the ideological nature, historical legacy, structure and capacity of administration and management and other push and factors. Public policy in Islamic economic system needs to be based on the key guidelines of divine scriptures along with other sources of sharia’h. As a representative of Allah (SWT), the governor and other apparatus of the state will formulate and implement public policies which will enable to establish a true welfare state based on justice, equity and equality. The whole life of Prophet Muhammad (pbuh) and his policy in operating state of affairs in Madina is the practical guidelines for the policy actors and professionals in Islamic system of economics. Moreover, policy makers need to be more meticulous in formulating Islamic public policy which meets the needs and demands of contemporary worlds as well.Keywords: formulation, Islam, public policy, policy factors, Sharia’h
Procedia PDF Downloads 35116716 Body Image Dissatifaction with and Personal Behavioral Control in Obese Patients Who are Attending to Treatment
Authors: Mariela Gonzalez, Zoraide Lugli, Eleonora Vivas, Rosana Guzmán
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The objective was to determine the predictive capacity of self-efficacy perceived for weight control, locus of weight control and skills of weight self-management in the dissatisfaction of the body image in obese people who attend treatment. Sectional study conducted in the city of Maracay, Venezuela, with 243 obese who attend to treatment, 173 of the feminine gender and 70 of the male, with ages ranging between 18 and 57 years old. The sample body mass index ranged between 29.39 and 44.14. The following instruments were used: The Body Shape Questionnaire (BSQ), the inventory of body weight self-regulation, The Inventory of self-efficacy in the regulation of body weight and the Inventory of the Locus of weight control. Calculating the descriptive statistics and of central tendency, coefficients of correlation and multiple regression; it was found that a low ‘perceived Self-efficacy in the weight control’ and a high ‘Locus of external control’, predict the dissatisfaction with body image in obese who attend treatment. The findings are a first approximation to give an account of the importance of the personal control variables in the study of the psychological grief on the overweight individual.Keywords: dissatisfaction with body image, obese people, personal control, psychological variables
Procedia PDF Downloads 43216715 Slip Suppression Sliding Mode Control with Various Chattering Functions
Authors: Shun Horikoshi, Tohru Kawabe
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This study presents performance analysis results of SMC (Sliding mode control) with changing the chattering functions applied to slip suppression problem of electric vehicles (EVs). In SMC, chattering phenomenon always occurs through high frequency switching of the control inputs. It is undesirable phenomenon and degrade the control performance, since it causes the oscillations of the control inputs. Several studies have been conducted on this problem by introducing some general saturation function. However, study about whether saturation function was really best and the performance analysis when using the other functions, weren’t being done so much. Therefore, in this paper, several candidate functions for SMC are selected and control performance of candidate functions is analyzed. In the analysis, evaluation function based on the trade-off between slip suppression performance and chattering reduction performance is proposed. The analyses are conducted in several numerical simulations of slip suppression problem of EVs. Then, we can see that there is no difference of employed candidate functions in chattering reduction performance. On the other hand, in slip suppression performance, the saturation function is excellent overall. So, we conclude the saturation function is most suitable for slip suppression sliding mode control.Keywords: sliding mode control, chattering function, electric vehicle, slip suppression, performance analysis
Procedia PDF Downloads 32616714 Precarious ID Cards - Studying Documentary Practices in India through the Lens of Internal Migration
Authors: Ambuja Raj
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This research will attempt to understand how documents are materially indispensable civic artifacts for migrants in their encounters with the state. Documents such as ID cards are sites of mediation and bureaucratic manifestation which reveal the inherent dynamics of power between the state and a delocalized people. While ID cards allow the holder to retain a different identity and articulate their demands as a citizen, they at the same time transform subjects into ‘objects’ in the exercise of governmental power. The research is based on the study of internal migrants in India, who are ‘visible’ to the state through its host of ID documents such as the ‘Aadhaar card’, electoral IDs, Ration cards, and a variety of region-specific documents, without the possession of which, not only are they unable to access jobs, public goods and services, and accommodation, but are liable to exploitation from state forces and mediators. Through semi-structured interviews with social actors in the processes of documentation and welfare of migrants, as well as with settlements of migrants themselves located in the state of Kerala in India, the thesis will attempt to understand the salience of documentary practices in the lives of inter-state migrants who move within Indian states in the hope of bettering their economic conditions. The research will trace the material and evolving significance of ID cards in the tenacity of states dealing with these ‘illegible’ populations. It will try to bring theories of governmentality, biopolitics and Weberian bureaucracy into the migrant issue while critically grounding itself on secondary literature by scholars who have worked on South Asian ‘governments of paper’.Keywords: migration, historiography of documents, anthropology of state, documentary practices
Procedia PDF Downloads 18816713 Ship Detection Requirements Analysis for Different Sea States: Validation on Real SAR Data
Authors: Jaime Martín-de-Nicolás, David Mata-Moya, Nerea del-Rey-Maestre, Pedro Gómez-del-Hoyo, María-Pilar Jarabo-Amores
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Ship detection is nowadays quite an important issue in tasks related to sea traffic control, fishery management and ship search and rescue. Although it has traditionally been carried out by patrol ships or aircrafts, coverage and weather conditions and sea state can become a problem. Synthetic aperture radars can surpass these coverage limitations and work under any climatological condition. A fast CFAR ship detector based on a robust statistical modeling of sea clutter with respect to sea states in SAR images is used. In this paper, the minimum SNR required to obtain a given detection probability with a given false alarm rate for any sea state is determined. A Gaussian target model using real SAR data is considered. Results show that SNR does not depend heavily on the class considered. Provided there is some variation in the backscattering of targets in SAR imagery, the detection probability is limited and a post-processing stage based on morphology would be suitable.Keywords: SAR, generalized gamma distribution, detection curves, radar detection
Procedia PDF Downloads 45216712 The State Support to the Tourism Policy Formation Mechanism in Black Sea Basin Countries (Azerbaijan, Turkey, Russia, Georgia) and Its Impact on Sustainable Tourism Development
Authors: A. Bahar Ganiyeva, M. Sabuhi Tanriverdiyev
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The article analyzes state support and policy mechanisms aimed at driving tourism as one of the vibrant and rapidly developing economies. State programs and long-range strategic roadmaps and previous programs execution, results and their impact on the particular countries economy have been raised during the research. This theme provides a useful framework for discussions with a wider range of stakeholders as the implications arising are of importance both for academics and practitioners engaged in hospitality and tourism development and research. The impact that tourism has on sustainable regional development in emerging markets is highly substantial. For Azerbaijan, Turkey, Georgia, and Russia, with their rich natural resources and cultural heritage, tourism can be an important basis for economic expansion, and a way to form an acceptable image of the countries as safe, open, hospitable, and complex.Keywords: Sustainable tourism, hospitality, destination, strategic roadmap, tourism, economy, growth, state support, mechanism, policy formation, state program
Procedia PDF Downloads 15816711 Human Gesture Recognition for Real-Time Control of Humanoid Robot
Authors: S. Aswath, Chinmaya Krishna Tilak, Amal Suresh, Ganesh Udupa
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There are technologies to control a humanoid robot in many ways. But the use of Electromyogram (EMG) electrodes has its own importance in setting up the control system. The EMG based control system helps to control robotic devices with more fidelity and precision. In this paper, development of an electromyogram based interface for human gesture recognition for the control of a humanoid robot is presented. To recognize control signs in the gestures, a single channel EMG sensor is positioned on the muscles of the human body. Instead of using a remote control unit, the humanoid robot is controlled by various gestures performed by the human. The EMG electrodes attached to the muscles generates an analog signal due to the effect of nerve impulses generated on moving muscles of the human being. The analog signals taken up from the muscles are supplied to a differential muscle sensor that processes the given signal to generate a signal suitable for the microcontroller to get the control over a humanoid robot. The signal from the differential muscle sensor is converted to a digital form using the ADC of the microcontroller and outputs its decision to the CM-530 humanoid robot controller through a Zigbee wireless interface. The output decision of the CM-530 processor is sent to a motor driver in order to control the servo motors in required direction for human like actions. This method for gaining control of a humanoid robot could be used for performing actions with more accuracy and ease. In addition, a study has been conducted to investigate the controllability and ease of use of the interface and the employed gestures.Keywords: electromyogram, gesture, muscle sensor, humanoid robot, microcontroller, Zigbee
Procedia PDF Downloads 40716710 Efficacy of Computer Mediated Power Point Presentations on Students' Learning Outcomes in Basic Science in Oyo State, Nigeria
Authors: Sunmaila Oyetunji Raimi, Olufemi Akinloye Bolaji, Abiodun Ezekiel Adesina
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The lingering poor performance of students in basic science spells doom for a vibrant scientific and technological development which pivoted the economic, social and physical upliftment of any nation. This calls for identifying appropriate strategies for imparting basic science knowledge and attitudes to the teaming youths in secondary schools. This study, therefore, determined the impact of computer mediated power point presentations on students’ achievement in basic science in Oyo State, Nigeria. A pre-test, posttest, control group quazi-experimental design adopted for the study. Two hundred and five junior secondary two students selected using stratified random sampling technique participated in the study. Three research questions and three hypotheses guided the study. Two evaluative instruments – Students’ Basic Science Attitudes Scale (SBSAS, r = 0.91); Students’ Knowledge of Basic Science Test (SKBST, r = 0.82) were used for data collection. Descriptive statistics of mean, standard deviation and inferential statistics of ANCOVA, scheffe post-hoc test were used to analyse the data. The results indicated significant main effect of treatment on students cognitive (F(1,200)= 171.680; p < 0.05) and attitudinal (F(1,200)= 34.466; p < 0.05) achievement in Basic science with the experimental group having higher mean gain than the control group. Gender has significant main effect (F(1,200)= 23.382; p < 0.05) on students cognitive outcomes but not significant for attitudinal achievement in Basic science. The study therefore recommended among others that computer mediated power point presentations should be incorporated into curriculum methodology of Basic science in secondary schools.Keywords: basic science, computer mediated power point presentations, gender, students’ achievement
Procedia PDF Downloads 42916709 Synthetic Optimizing Control of Wind-Wave Hybrid Energy Conversion System
Authors: Lei Xue, Liye Zhao, Jundong Wang, Yu Xue
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A hybrid energy conversion system composed of a floating offshore wind turbine (FOWT) and wave energy converters (WECs) may possibly reduce the levelized cost of energy, improving the platform dynamics and increasing the capacity to harvest energy. This paper investigates the aerodynamic performance and dynamic responses of the combined semi-submersible FOWT and point-absorber WECs in frequency and time domains using synthetic optimizing control under turbulent wind and irregular wave conditions. Individual pitch control is applied to the FOWT part, while spring–damping control is used on the WECs part, as well as the synergistic control effect of both are studied. The effect of the above control optimization is analyzed under several typical working conditions, such as below-rated wind speed, rated wind speed, and above-rated wind speed by OpenFAST and WEC-Sim software. Particularly, the wind-wave misalignment is also comparatively investigated, which has demonstrated the importance of applying proper integrated optimal control in this hybrid energy system. More specifically, the combination of individual pitch control and spring–damping control is able to mitigate the platform pitch motion and improve output power. However, the increase in blade root load needs to be considered which needs further investigations in the future.Keywords: floating offshore wind turbine, wave energy converters, control optimization, individual pitch control, dynamic response
Procedia PDF Downloads 5316708 Control of Underactuated Biped Robots Using Event Based Fuzzy Partial Feedback Linearization
Authors: Omid Heydarnia, Akbar Allahverdizadeh, Behnam Dadashzadeh, M. R. Sayyed Noorani
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Underactuated biped robots control is one of the interesting topics in robotics. The main difficulties are its highly nonlinear dynamics, open-loop instability, and discrete event at the end of the gait. One of the methods to control underactuated systems is the partial feedback linearization, but it is not robust against uncertainties and disturbances that restrict its performance to control biped walking and running. In this paper, fuzzy partial feedback linearization is presented to overcome its drawback. Numerical simulations verify the effectiveness of the proposed method to generate stable and robust biped walking and running gaits.Keywords: underactuated system, biped robot, fuzzy control, partial feedback linearization
Procedia PDF Downloads 35016707 Trajectory Tracking of Fixed-Wing Unmanned Aerial Vehicle Using Fuzzy-Based Sliding Mode Controller
Authors: Feleke Tsegaye
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The work in this thesis mainly focuses on trajectory tracking of fixed wing unmanned aerial vehicle (FWUAV) by using fuzzy based sliding mode controller(FSMC) for surveillance applications. Unmanned Aerial Vehicles (UAVs) are general-purpose aircraft built to fly autonomously. This technology is applied in a variety of sectors, including the military, to improve defense, surveillance, and logistics. The model of FWUAV is complex due to its high non-linearity and coupling effect. In this thesis, input decoupling is done through extracting the dominant inputs during the design of the controller and considering the remaining inputs as uncertainty. The proper and steady flight maneuvering of UAVs under uncertain and unstable circumstances is the most critical problem for researchers studying UAVs. A FSMC technique was suggested to tackle the complexity of FWUAV systems. The trajectory tracking control algorithm primarily uses the sliding-mode (SM) variable structure control method to address the system’s control issue. In the SM control, a fuzzy logic control(FLC) algorithm is utilized in place of the discontinuous phase of the SM controller to reduce the chattering impact. In the reaching and sliding stages of SM control, Lyapunov theory is used to assure finite-time convergence. A comparison between the conventional SM controller and the suggested controller is done in relation to the chattering effect as well as tracking performance. It is evident that the chattering is effectively reduced, the suggested controller provides a quick response with a minimum steady-state error, and the controller is robust in the face of unknown disturbances. The designed control strategy is simulated with the nonlinear model of FWUAV using the MATLAB® / Simulink® environments. The simulation result shows the suggested controller operates effectively, maintains an aircraft’s stability, and will hold the aircraft’s targeted flight path despite the presence of uncertainty and disturbances.Keywords: fixed-wing UAVs, sliding mode controller, fuzzy logic controller, chattering, coupling effect, surveillance, finite-time convergence, Lyapunov theory, flight path
Procedia PDF Downloads 5716706 Systematic and Simple Guidance for Feed Forward Design in Model Predictive Control
Authors: Shukri Dughman, Anthony Rossiter
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This paper builds on earlier work which demonstrated that Model Predictive Control (MPC) may give a poor choice of default feed forward compensator. By first demonstrating the impact of future information of target changes on the performance, this paper proposes a pragmatic method for identifying the amount of future information on the target that can be utilised effectively in both finite and infinite horizon algorithms. Numerical illustrations in MATLAB give evidence of the efficacy of the proposal.Keywords: model predictive control, tracking control, advance knowledge, feed forward
Procedia PDF Downloads 54716705 Advantages of Fuzzy Control Application in Fast and Sensitive Technological Processes
Authors: Radim Farana, Bogdan Walek, Michal Janosek, Jaroslav Zacek
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This paper presents the advantages of fuzzy control use in technological processes control. The paper presents a real application of the Linguistic Fuzzy-Logic Control, developed at the University of Ostrava for the control of physical models in the Intelligent Systems Laboratory. The paper presents an example of a sensitive non-linear model, such as a magnetic levitation model and obtained results which show how modern information technologies can help to solve actual technical problems. A special method based on the LFLC controller with partial components is presented in this paper followed by the method of automatic context change, which is very helpful to achieve more accurate control results. The main advantage of the used system is its robustness in changing conditions demonstrated by comparing with conventional PID controller. This technology and real models are also used as a background for problem-oriented teaching, realized at the department for master students and their collaborative as well as individual final projects.Keywords: control, fuzzy logic, sensitive system, technological proves
Procedia PDF Downloads 46916704 Fragile States as the Fertile Ground for Non-State Actors: Colombia and Somalia
Authors: Giorgi Goguadze, Jakub Zajączkowski
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This paper is written due to overview the connection between fragile states and non-state actors, we should take into account that fragile states may vary from weak, failing and failed. In this paper we will discuss about two countries, one of them is weak (Colombia/ second one is already failed- Somalia. We will try to understand what feeds ill non-state actors such as: terrorist organizations, criminal entities and other cells in these countries, what threats are they representing and how to eliminate these dangers in both national and international scope. This paper is mainly based on literature overview and personal attitude and doesn’t claim to be in scientific chain.Keywords: fragile States, terrorism, tribalism, Somalia
Procedia PDF Downloads 36716703 Robust Control Design and Analysis Using SCILAB for a Mass-Spring-Damper System
Authors: Yoonsoo Kim
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This paper introduces an open-source software package SCILAB, an alternative of MATLAB, which can be used for robust control design and analysis of a typical mass-spring-damper (MSD) system. Using the previously published ideas in this popular mechanical system is considered to provide another example of usefulness of SCILAB for advanced control design.Keywords: robust control, SCILAB, mass-spring-damper (MSD), popular mechanical systems
Procedia PDF Downloads 47216702 Synthesis and Characterization of Ferromagnetic Ni-Cu Alloys for Thermal Rectification Applications
Authors: Josue Javier Martinez Flores, Jaime Alvarez Quintana
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A thermal rectifier consists of a device which can load a different heat flow which depends on the direction of that flow. That device is a thermal diode. It is well known that heat transfer in solids basically depends on the electrical, magnetic and crystalline nature of materials via electrons, magnons and phonons as thermal energy carriers respectively. In the present research, we have synthesized polycrystalline Ni-Cu alloys and identified the Curie temperatures; and we have observed that by way of secondary phase transitions, it is possible manipulate the heat conduction in solid state thermal diodes via transition temperature. In this sense, we have succeeded in developing solid state thermal diodes with a control gate through the Curie temperature via the activation and deactivation of magnons in Ni-Cu ferromagnetic alloys at room temperature. Results show thermal diodes with thermal rectification factors up to 1.5. Besides, the performance of the electrical rectifiers can be controlled by way of alloy Cu content; hence, lower Cu content alloys present enhanced thermal rectifications factors than higher ones.Keywords: thermal rectification, Curie temperature, ferromagnetic alloys, magnons
Procedia PDF Downloads 24616701 Threat of Islamic State of Khorasan in Pakistan and Afghanistan Region: Impact on Regional Security
Authors: Irfan U. Din
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The growing presence and operational capacity of Islamic State aka Daesh, which emerged in Pak-Afghan region in 2015, poses a serious threat to the already fragile state of the security situation in the region. This paper will shed light on the current state of IS-K network in the Pak-Afghan region and will explain how its presence and operational capacity in the northern and central Afghanistan has increased despite intensive military operations against the group in Nangarhar province – the stronghold of IS-K. It will also explore the role of Pakistani Taliban in the emergence and expansion of IS-K in the region and will unveil the security implication of growing nexus of IS-K and transnational organized groups for the region in Post NATO withdrawal scenario. The study will be qualitative and will rely on secondary and primary data to explore the topic. For secondary data existing literature on the topic will be extensively reviewed while for primary data in-depth interviews will be conducted with subject experts, Taliban commanders, and field researchers.Keywords: Islamic State of Khorasan (IS-K), North Atlantic Treaty Organization (NATO), Pak-Afghan Region, Transnational Organized Crime (TNOC)
Procedia PDF Downloads 29016700 Quality Control Assessment of X-Ray Equipment in Hospitals of Katsina State, Nigeria
Authors: Aminu Yakubu Umar
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X-ray is the major contributor to the effective dose of both the patient and the personnel. Because of the radiological risks involved, it is usually recommended that dose to patient from X-ray be kept as low as reasonably achievable (ALARA) with adequate image quality. The implementation of quality assurance in diagnostic radiology can help greatly in achieving that, as it is a technique designed to reduce X-ray doses to patients undergoing radiological examination. In this study, quality control was carried out in six hospitals, which involved KVp test, evaluation of total filtration, test for constancy of radiation output, and check for mA linearity. Equipment used include KVp meter, Rad-check meter, aluminum sheets (0.1–1.0 mm) etc. The results of this study indicate that, the age of the X-ray machines in the hospitals ranges from 3-13 years, GHI and GH2 being the oldest and FMC being the newest. In the evaluation of total filtration, the HVL of the X-ray machines in the hospitals varied, ranging from 2.3-5.2 mm. The HVL was found to be highest in AHC (5.2 mm), while it was lowest in GH3 (2.3 mm). All HVL measurements were done at 80 KVp. The variation in voltage accuracy in the hospitals ranges from 0.3%-127.5%. It was only in GH1 that the % variation was below the allowed limit. The test for constancy of radiation output showed that, the coefficient of variation ranges from 0.005–0.550. In GH3, FMC and AHC, the coefficient of linearity were less than the allowed limit, while in GH1, GH2 and GH4 the coefficient of linearity had exceeded the allowed limit. As regard to mA linearity, FMC and AHC had their coefficients of linearity as 0.12 and 0.10 respectively, which were within the accepted limit, while GH1, GH3 and GH4 had their coefficients as 0.16, 0.69 and 0.98 respectively, which exceeded the allowed limit.Keywords: radiation, X-ray output, quality control, half-value layer, mA linearity, KVp variation
Procedia PDF Downloads 60916699 The Effectiveness of Psychodrama on Anxiety Enhancement in Adolescent Boys
Authors: Saeed Dehnavi, Marjan Pooee
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Background - Psychodrama, as a form of art therapy, helps people to enact and use role-plays for a specific problem, rather than just talking about it, in an effort to review the problem, gain feedback from group members, find appropriate solutions, and practice them for their life. This paper evaluated the effectiveness of psychodrama on enhancing anxiety of young adolescent boys. Methodology - This is aquasi-experimental research study, using a pre-post testing plan with control group. From four secondary schools in Kermanshah - Iran, 210 adolescent boys (aged 13 and 14 years) were asked to complete Koper Smith's self-esteem measure scale. Given the low self-esteem scores (less than the cut-off of 23), a number of 20 individuals were selected and randomly placed into two control and experimental groups. The experimental group participated in a twelve-session psychodrama therapy plan for 6 weeks, while the control group received no intervention. Data analysis was carried out by the analysis of covariance (ANCOVA). Results - The results of ANCOVA analysis showed an increase in the post-test scores for anxiety, and such increase was statistically significant. Conclusion - The findings indicated the effectiveness of psychodrama on anxiety enhancement of young boys. During psychodrama sessions, the adolescents learned to take the initiative, communicate with others in an excited state, and improve their anxiety with positive and constructive experiences.Keywords: anxiety, art therapy, psychodrama, young adolescents
Procedia PDF Downloads 54316698 Hybrid GA-PSO Based Pitch Controller Design for Aircraft Control System
Authors: Vaibhav Singh Rajput, Ravi Kumar Jatoth, Nagu Bhookya, Bhasker Boda
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In this paper proportional, integral, derivative (PID) controller is used to control the pitch angle of the aircraft when the elevation angle is changed or modified. The pitch angle is dependent on elevation angle; a change in one corresponds to a change in the other. The PID controller helps in restricted change of pitch rate in response to the elevation angle. The PID controller is dependent on different parameters like Kp, Ki, Kd which change the pitch rate as they change. Various methodologies are used for changing those parameters for getting a perfect time response pitch angle, as desired or wished by a concerned person. While reckoning the values of those parameters, trial and guessing may prove to be futile in order to provide comfort to passengers. So, using some metaheuristic techniques can be useful in handling these errors. Hybrid GA-PSO is one such powerful algorithm which can improve transient and steady state response and can give us more reliable results for PID gain scheduling problem.Keywords: pitch rate, elevation angle, PID controller, genetic algorithm, particle swarm optimization, phugoid
Procedia PDF Downloads 32716697 Nonlinear Model Predictive Control of Water Quality in Drinking Water Distribution Systems with DBPs Objetives
Authors: Mingyu Xie, Mietek Brdys
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The paper develops a non-linear model predictive control (NMPC) of water quality in drinking water distribution systems (DWDS) based on the advanced non-linear quality dynamics model including disinfections by-products (DBPs). A special attention is paid to the analysis of an impact of the flow trajectories prescribed by an upper control level of the recently developed two-time scale architecture of an integrated quality and quantity control in DWDS. The new quality controller is to operate within this architecture in the fast time scale as the lower level quality controller. The controller performance is validated by a comprehensive simulation study based on an example case study DWDS.Keywords: model predictive control, hierarchical control structure, genetic algorithm, water quality with DBPs objectives
Procedia PDF Downloads 31716696 Control of a Stewart Platform for Minimizing Impact Energy in Simulating Spacecraft Docking Operations
Authors: Leonardo Herrera, Shield B. Lin, Stephen J. Montgomery-Smith, Ziraguen O. Williams
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Three control algorithms: Proportional-Integral-Derivative, Linear-Quadratic-Gaussian, and Linear-Quadratic-Gaussian with the shift, were applied to the computer simulation of a one-directional dynamic model of a Stewart Platform. The goal was to compare the dynamic system responses under the three control algorithms and to minimize the impact energy when simulating spacecraft docking operations. Equations were derived for the control algorithms and the input and output of the feedback control system. Using MATLAB, Simulink diagrams were created to represent the three control schemes. A switch selector was used for the convenience of changing among different controllers. The simulation demonstrated the controller using the algorithm of Linear-Quadratic-Gaussian with the shift resulting in the lowest impact energy.Keywords: controller, Stewart platform, docking operation, spacecraft
Procedia PDF Downloads 5116695 H∞ Fuzzy Integral Power Control for DFIG Wind Energy System
Authors: N. Chayaopas, W. Assawinchaichote
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In order to maximize energy capturing from wind energy, controlling the doubly fed induction generator to have optimal power from the wind, generator speed and output electrical power control in wind energy system have a great importance due to the nonlinear behavior of wind velocities. In this paper purposes the design of a control scheme is developed for power control of wind energy system via H∞ fuzzy integral controller. Firstly, the nonlinear system is represented in term of a TS fuzzy control design via linear matrix inequality approach to find the optimal controller to have an H∞ performance are derived. The proposed control method extract the maximum energy from the wind and overcome the nonlinearity and disturbances problems of wind energy system which give good tracking performance and high efficiency power output of the DFIG.Keywords: doubly fed induction generator, H-infinity fuzzy integral control, linear matrix inequality, wind energy system
Procedia PDF Downloads 34716694 Lyapunov-Based Tracking Control for Nonholonomic Wheeled Mobile Robot
Authors: Raouf Fareh, Maarouf Saad, Sofiane Khadraoui, Tamer Rabie
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This paper presents a tracking control strategy based on Lyapunov approach for nonholonomic wheeled mobile robot. This control strategy consists of two levels. First, a kinematic controller is developed to adjust the right and left wheel velocities. Using this velocity control law, the stability of the tracking error is guaranteed using Lyapunov approach. This kinematic controller cannot be generated directly by the motors. To overcome this problem, the second level of the controllers, dynamic control, is designed. This dynamic control law is developed based on Lyapunov theory in order to track the desired trajectories of the mobile robot. The stability of the tracking error is proved using Lupunov and Barbalat approaches. Simulation results on a nonholonomic wheeled mobile robot are given to demonstrate the feasibility and effectiveness of the presented approach.Keywords: mobile robot, trajectory tracking, Lyapunov, stability
Procedia PDF Downloads 37216693 Optimal Bayesian Control of the Proportion of Defectives in a Manufacturing Process
Authors: Viliam Makis, Farnoosh Naderkhani, Leila Jafari
Abstract:
In this paper, we present a model and an algorithm for the calculation of the optimal control limit, average cost, sample size, and the sampling interval for an optimal Bayesian chart to control the proportion of defective items produced using a semi-Markov decision process approach. Traditional p-chart has been widely used for controlling the proportion of defectives in various kinds of production processes for many years. It is well known that traditional non-Bayesian charts are not optimal, but very few optimal Bayesian control charts have been developed in the literature, mostly considering finite horizon. The objective of this paper is to develop a fast computational algorithm to obtain the optimal parameters of a Bayesian p-chart. The decision problem is formulated in the partially observable framework and the developed algorithm is illustrated by a numerical example.Keywords: Bayesian control chart, semi-Markov decision process, quality control, partially observable process
Procedia PDF Downloads 31816692 Research on Measuring Operational Risk in Commercial Banks Based on Internal Control
Authors: Baobao Li
Abstract:
Operational risk covers all operations of commercial banks and has a close relationship with the bank’s internal control. But in the commercial banks' management practice, internal control is always separated from the operational risk measurement. With the increasing of operational risk events in recent years, operational risk is paid more and more attention by regulators and banks’ managements. The paper first discussed the relationship between internal control and operational risk management and used CVaR-POT model to measure operational risk, and then put forward a modified measurement method (to use operational risk assessment results to modify the measurement results of the CVaR-POT model). The paper also analyzed the necessity and rationality of this method. The method takes into consideration the influence of internal control, improves the accuracy and effectiveness of operational risk measurement and save the economic capital for commercial banks, avoiding the drawbacks of using some mainstream models one-sidedly.Keywords: commercial banks, internal control, operational risk, risk measurement
Procedia PDF Downloads 398