Search results for: service simulation
626 Performance Analysis of Deterministic Stable Election Protocol Using Fuzzy Logic in Wireless Sensor Network
Authors: Sumanpreet Kaur, Harjit Pal Singh, Vikas Khullar
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In Wireless Sensor Network (WSN), the sensor containing motes (nodes) incorporate batteries that can lament at some extent. To upgrade the energy utilization, clustering is one of the prototypical approaches for split sensor motes into a number of clusters where one mote (also called as node) proceeds as a Cluster Head (CH). CH selection is one of the optimization techniques for enlarging stability and network lifespan. Deterministic Stable Election Protocol (DSEP) is an effectual clustering protocol that makes use of three kinds of nodes with dissimilar residual energy for CH election. Fuzzy Logic technology is used to expand energy level of DSEP protocol by using fuzzy inference system. This paper presents protocol DSEP using Fuzzy Logic (DSEP-FL) CH by taking into account four linguistic variables such as energy, concentration, centrality and distance to base station. Simulation results show that our proposed method gives more effective results in term of a lifespan of network and stability as compared to the performance of other clustering protocols.
Keywords: Deterministic stable election protocol, energy model, fuzzy logic, wireless sensor network.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 977625 Design of Robust Fuzzy Logic Power System Stabilizer
Authors: S. A. Taher, A. Shemshadi
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Power system stabilizers (PSS) must be capable of providing appropriate stabilization signals over a broad range of operating conditions and disturbance. Traditional PSS rely on robust linear design method in an attempt to cover a wider range of operating condition. Expert or rule-based controllers have also been proposed. Recently fuzzy logic (FL) as a novel robust control design method has shown promising results. The emphasis in fuzzy control design center is around uncertainties in the system parameters & operating conditions. In this paper a novel Robust Fuzzy Logic Power System Stabilizer (RFLPSS) design is proposed The RFLPSS basically utilizes only one measurable Δω signal as input (generator shaft speed). The speed signal is discretized resulting in three inputs to the RFLPSS. There are six rules for the fuzzification and two rules for defuzzification. To provide robustness, additional signal namely, speed are used as inputs to RFLPSS enabling appropriate gain adjustments for the three RFLPSS inputs. Simulation studies show the superior performance of the RFLPSS compared with an optimally designed conventional PSS and discrete mode FLPSS.Keywords: Controller design, Fuzzy Logic, PID, Power SystemStabilizer, Robust control.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2136624 Vortex-Induced Vibration Characteristics of an Elastic Circular Cylinder
Authors: T. Li, J.Y. Zhang, W.H. Zhang, M.H. Zhu
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A numerical simulation of vortex-induced vibration of a 2-dimensional elastic circular cylinder with two degree of freedom under the uniform flow is calculated when Reynolds is 200. 2-dimensional incompressible Navier-Stokes equations are solved with the space-time finite element method, the equation of the cylinder motion is solved with the new explicit integral method and the mesh renew is achieved by the spring moving mesh technology. Considering vortex-induced vibration with the low reduced damping parameter, the variety trends of the lift coefficient, the drag coefficient, the displacement of cylinder are analyzed under different oscillating frequencies of cylinder. The phenomena of locked-in, beat and phases-witch were captured successfully. The evolution of vortex shedding from the cylinder with time is discussed. There are very similar trends in characteristics between the results of the one degree of freedom cylinder model and that of the two degree of freedom cylinder model. The streamwise vibrations have a certain effect on the lateral vibrations and their characteristics.Keywords: Fluid-structure interaction, Navier-Stokes equation, Space-time finite element method, vortex-induced vibration.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2923623 The Impact of COVID-19 Pandemic on Acute Urology Admissions in a Busy District General Hospital in the UK
Authors: D. Bheenick, M. Young, M. Elmussareh, A. Ali
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Coronavirus disease 2019 (COVID-19) has had unprecedented effects on the healthcare system in the UK. The pandemic has impacted every service within secondary care, including urology. Our objective is to determine how COVID-19 has influenced acute urology admissions in a busy district general hospital in the UK. To conduct the study, retrospective data of patients presenting acutely to the urology department were collected between January 13 to March 22, 2020 (pre-lockdown period) and March 23 to May 31, 2020 (lockdown period). The nature of referrals, types of admission encountered, and management required in accordance with the new set of protocols established during the lockdown period were analysed and compared to the same data prior to UK lockdown. Included in the study were 1092 patients. The results show that an overall reduction of 32.5% was seen in the total number of admissions. A marked decrease was seen in non-urological pathology as compared to other categories. Urolithiasis showed the highest proportional increase. Treatment varied proportionately to the diagnosis, with conservative management accounting for the most likely treatment during lockdown. However, the proportion of patients requiring interventions during the lockdown period increased overall. No comparative differences were observed during the two periods in terms of source of referral, length of stay and patient age. The results of the study concluded that the admission rate showed a decrease, with no significant difference in the nature and timing of presentation. Our department was able to continue providing effective management to patients presenting acutely during the COVID-19 outbreak.
Keywords: COVID-19, lockdown, admissions, urology
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 401622 A High Performance Technique in Harmonic Omitting Based on Predictive Current Control of a Shunt Active Power Filter
Authors: K. G. Firouzjah, A. Sheikholeslami
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The perfect operation of common Active Filters is depended on accuracy of identification system distortion. Also, using a suitable method in current injection and reactive power compensation, leads to increased filter performance. Due to this fact, this paper presents a method based on predictive current control theory in shunt active filter applications. The harmonics of the load current is identified by using o–d–q reference frame on load current and eliminating the DC part of d–q components. Then, the rest of these components deliver to predictive current controller as a Threephase reference current by using Park inverse transformation. System is modeled in discreet time domain. The proposed method has been tested using MATLAB model for a nonlinear load (with Total Harmonic Distortion=20%). The simulation results indicate that the proposed filter leads to flowing a sinusoidal current (THD=0.15%) through the source. In addition, the results show that the filter tracks the reference current accurately.
Keywords: Active filter, predictive current control, low pass filter, harmonic omitting, o–d–q reference frame.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1830621 Study of Tower Grounding Resistance Effected Back Flashover to 500 kV Transmission Line in Thailand by using ATP/EMTP
Authors: B. Marungsri, S. Boonpoke, A. Rawangpai, A. Oonsivilai, C. Kritayakornupong
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This study describes analysis of tower grounding resistance effected the back flashover voltage across insulator string in a transmission system. This paper studies the 500 kV transmission lines from Mae Moh, Lampang to Nong Chok, Bangkok, Thailand, which is double circuit in the same steel tower with two overhead ground wires. The factor of this study includes magnitude of lightning stroke, and front time of lightning stroke. Steel tower uses multistory tower model. The assumption of studies based on the return stroke current ranged 1-200 kA, front time of lightning stroke between 1 μs to 3 μs. The simulations study the effect of varying tower grounding resistance that affect the lightning current. Simulation results are analyzed lightning over voltage that causes back flashover at insulator strings. This study helps to know causes of problems of back flashover the transmission line system, and also be as a guideline solving the problem for 500 kV transmission line systems, as well.Keywords: Tower grounding resistance, back flashover, multistory tower model, lightning stroke current.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 4342620 Adaptive Control Strategy of Robot Polishing Force Based on Position Impedance
Authors: Wang Zhan-Xi, Zhang Yi-Ming, Chen Hang, Wang Gang
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Manual polishing has problems such as high labor intensity, low production efficiency and difficulty in guaranteeing the consistency of polishing quality. The use of robot polishing instead of manual polishing can effectively avoid these problems. Polishing force directly affects the quality of polishing, so accurate tracking and control of polishing force is one of the most important conditions for improving the accuracy of robot polishing. The traditional force control strategy is difficult to adapt to the strong coupling of force control and position control during the robot polishing process. Therefore, based on the analysis of force-based impedance control and position-based impedance control, this paper proposed a type of adaptive controller. Based on force feedback control of active compliance control, the controller can adaptively estimate the stiffness and position of the external environment and eliminate the steady-state force error produced by traditional impedance control. The simulation results of the model show that the adaptive controller has good adaptability to changing environmental positions and environmental stiffness, and can accurately track and control polishing force.
Keywords: robot polishing, force feedback, impedance control, adaptive control
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 617619 A Water Reuse System in Wetland Paddy Supports the Growing Industrial Water Needs
Authors: Yu-Chuan Chang, Chen Shi-Kai
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A water reuse system in wetland paddy was simulated to supply water for industrial in this paper. A two-tank model was employed to represent the return flow of the wetland paddy.Historical data were performed for parameter estimation and model verification. With parameters estimated from the data, the model was then used to simulate a reasonable return flow rate from the wetland paddy. The simulation results show that the return flow ratio was 11.56% in the first crop season and 35.66% in the second crop season individually; the difference may result from the heavy rainfall in the second crop season. Under the existent pond with surplus active capacity, the water reuse ratio was 17.14%, and the water supplementary ratio was 21.56%. However, the pattern of rainfall, the active capacity of the pond, and the rate of water treatment limit the volume of reuse water. Increasing the irrigation water, dredging the depth of pond before rainy season and enlarging the scale of module are help to develop water reuse system to support for the industrial water use around wetland paddy.Keywords: Return flow, water reuse, wetland paddy, return flow ratio (RR), water reuse ratio (WRR), water supplementary ratio(WSR)
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1309618 The Effect of Religious Tourist Motivation and Satisfaction on Behavioral Intention
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In recent years, the Chaoshan area, a special place located in the southeast of Guangdong province in China, actively protects religious heritage and is developing religious tourism, which is attracting many expatriate Chinese who are coming back for travel and to worship. This paper discussed three questions. Firstly, what is the current situation about the different social background of tourists’ motivation, satisfaction and behavioral intention? Secondly, is there a relationship between the motivation, satisfaction and behavioral intention and the different social backgrounds of tourists? Thirdly, what is the relationship between religious tourists’ motivation, satisfaction and behavioral intention? The research methods use a combination of qualitative analysis and quantitative analysis. Qualitative analysis uses the method of observation and interviews. Convenient sampling technique was used for quantitative analysis. The study showed that the different social backgrounds of tourists’ forms diverse cognition and experiences about religious tourism, and their motivations, satisfaction and behavioral intention as tourists vary. Tourists’ motivation and satisfaction has a positive phase relation. Tourists’ motivation with satisfaction as the intervening variable also has a positive phase effect on tourists’ behavior intention. The result shows that religious tourists’ motivations include experiencing a religious atmosphere, and having a rest and recreation. The result also shows that religious tourists want to travel with their family members and friends. While traveling, religious tourists like to talk with Buddhist monks or nuns. Compared to other tourism types, religious tourists have higher expectations about temple environment, traveling experience, peripheral service and temple management.Keywords: Behavioral intension, motivation, religious tourism, satisfaction.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2026617 Optimal Channel Equalization for MIMO Time-Varying Channels
Authors: Ehab F. Badran, Guoxiang Gu
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We consider optimal channel equalization for MIMO (multi-input/multi-output) time-varying channels in the sense of MMSE (minimum mean-squared-error), where the observation noise can be non-stationary. We show that all ZF (zero-forcing) receivers can be parameterized in an affine form which eliminates completely the ISI (inter-symbol-interference), and optimal channel equalizers can be designed through minimization of the MSE (mean-squarederror) between the detected signals and the transmitted signals, among all ZF receivers. We demonstrate that the optimal channel equalizer is a modified Kalman filter, and show that under the AWGN (additive white Gaussian noise) assumption, the proposed optimal channel equalizer minimizes the BER (bit error rate) among all possible ZF receivers. Our results are applicable to optimal channel equalization for DWMT (discrete wavelet multitone), multirate transmultiplexers, OFDM (orthogonal frequency division multiplexing), and DS (direct sequence) CDMA (code division multiple access) wireless data communication systems. A design algorithm for optimal channel equalization is developed, and several simulation examples are worked out to illustrate the proposed design algorithm.Keywords: Channel equalization, Kalman filtering, Time-varying systems.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1834616 Optimization of Process Parameters Affecting on Spring-Back in V-Bending Process for High Strength Low Alloy Steel HSLA 420 Using FEA (HyperForm) and Taguchi Technique
Authors: Navajyoti Panda, R. S. Pawar
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In this study, process parameters like punch angle, die opening, grain direction, and pre-bend condition of the strip for deep draw of high strength low alloy steel HSLA 420 are investigated. The finite element method (FEM) in association with the Taguchi and the analysis of variance (ANOVA) techniques are carried out to investigate the degree of importance of process parameters in V-bending process for HSLA 420&ST12 grade material. From results, it is observed that punch angle had a major influence on the spring-back. Die opening also showed very significant role on spring back. On the other hand, it is revealed that grain direction had the least impact on spring back; however, if strip from flat sheet is taken, then it is less prone to spring back as compared to the strip from sheet metal coil. HyperForm software is used for FEM simulation and experiments are designed using Taguchi method. Percentage contribution of the parameters is obtained through the ANOVA techniques.
Keywords: Bending, V-bending, FEM, spring-back, Taguchi, HyperForm, profile projector, HSLA 420 & St12 materials.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1450615 Distributed Relay Selection and Channel Choice in Cognitive Radio Network
Authors: Hao He, Shaoqian Li
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In this paper, we study the cooperative communications where multiple cognitive radio (CR) transmit-receive pairs competitive maximize their own throughputs. In CR networks, the influences of primary users and the spectrum availability are usually different among CR users. Due to the existence of multiple relay nodes and the different spectrum availability, each CR transmit-receive pair should not only select the relay node but also choose the appropriate channel. For this distributed problem, we propose a game theoretic framework to formulate this problem and we apply a regret-matching learning algorithm which is leading to correlated equilibrium. We further formulate a modified regret-matching learning algorithm which is fully distributed and only use the local information of each CR transmit-receive pair. This modified algorithm is more practical and suitable for the cooperative communications in CR network. Simulation results show the algorithm convergence and the modified learning algorithm can achieve comparable performance to the original regretmatching learning algorithm.
Keywords: cognitive radio, cooperative communication, relay selection, channel choice, regret-matching learning, correlated equilibrium.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1676614 Rural – Urban Partnership for Balanced Spatial Development in Latvia
Authors: Zane Bulderberga
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Spatial dimension in development planning is becoming more topical in 21st century as a result of changes in population structure. Sustainable spatial development focuses on identifying and using territorial advantages to foster the harmonized development of the entire country, reducing negative effects of population concentration, increasing availability and mobility. EU and national development planning documents state polycentrism as main tool for balance spatial development, including investment concentration in growth centres. If mutual cooperation of growth centres as well as urban–rural cooperation is not fostered, then territorial differences can deepen and create unbalanced development.
The aim of research: to evaluate the urban–rural interaction, elaborating spatial development scenarios in framework of Latvian regional policy. To perform the research monographic, comparison, abstract–logical method, synthesis and analysis will be used when studying the theoretical aspects of research aiming at collecting the ideas of scientists from different countries, concepts, regulations as well as to create meaningful scientific discussion. Hierarchy analysis process (AHP) will be used to state further scenarios of spatial development in Latvia.
Experts from various institutions recognized urban – rural interaction and co-operation as an essential tool for the development. The most important factors for balanced spatial development in Latvia are availability of public transportation and improvement of service availability. Evaluating the three alternative scenarios, it was concluded that the urban – rural partnership will ensure a balanced development in Latvian regions.
Keywords: Rural – urban interaction, rural – urban cooperation, spatial development, AHP.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2831613 Trap Assisted Tunneling Model for Gate Current in Nano Scale MOSFET with High-K Gate Dielectrics
Authors: Ashwani K. Rana, Narottam Chand, Vinod Kapoor
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This paper presents a new compact analytical model of the gate leakage current in high-k based nano scale MOSFET by assuming a two-step inelastic trap-assisted tunneling (ITAT) process as the conduction mechanism. This model is based on an inelastic trap-assisted tunneling (ITAT) mechanism combined with a semiempirical gate leakage current formulation in the BSIM 4 model. The gate tunneling currents have been calculated as a function of gate voltage for different gate dielectrics structures such as HfO2, Al2O3 and Si3N4 with EOT (equivalent oxide thickness) of 1.0 nm. The proposed model is compared and contrasted with santaurus simulation results to verify the accuracy of the model and excellent agreement is found between the analytical and simulated data. It is observed that proposed analytical model is suitable for different highk gate dielectrics simply by adjusting two fitting parameters. It was also shown that gate leakages reduced with the introduction of high-k gate dielectric in place of SiO2.Keywords: Analytical model, High-k gate dielectrics, inelastic trap assisted tunneling, metal–oxide–semiconductor (MOS) devices.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3307612 Influence of Behavior Models on the Response of a Reinforced Concrete Frame: Multi-Fiber Approach
Authors: A. Kahil, A. Nekmouche, N. Khelil, I. Hamadou, M. Hamizi, Ne. Hannachi
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The objective of this work is to study the influence of the nonlinear behavior models of the concrete (concrete_BAEL and concrete_UNI) as well as the confinement brought by the transverse reinforcement on the seismic response of reinforced concrete frame (RC/frame). These models as well as the confinement are integrated in the Cast3m finite element calculation code. The consideration of confinement (TAC, taking into account the confinement) provided by the transverse reinforcement and the non-consideration of confinement (without consideration of containment, WCC) in the presence and absence of a vertical load is studied. The application was made on a reinforced concrete frame (RC/frame) with 3 levels and 2 spans. The results show that on the one hand, the concrete_BAEL model slightly underestimates the resistance of the RC/frame in the plastic field, whereas the concrete_uni model presents the best results compared to the simplified model "concrete_BAEL", on the other hand, for the concrete-uni model, taking into account the confinement has no influence on the behavior of the RC/frame under imposed displacement up to a vertical load of 500 KN.
Keywords: Reinforced concrete, nonlinear calculation, behavior laws, fiber model confinement, numerical simulation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 680611 Learning through Shared Procedures -A Case of Using Technology to Bridge the Gap between Theory and Practice in Officer Education
Authors: O. Boe, S-T. Kristiansen, R. Wold
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In this article we explore how computer assisted exercises may allow for bridging the traditional gap between theory and practice in professional education. To educate officers able to master the complexity of the battlefield the Norwegian Military Academy needs to develop a learning environment that allows for creating viable connections between the educational environment and the field of practice. In response to this challenge we explore the conditions necessary to make computer assisted training systems (CATS) a useful tool to create structural similarities between an educational context and the field of military practice. Although, CATS may facilitate work procedures close to real life situations, this case do demonstrate how professional competence also must build on viable learning theories and environments. This paper explores the conditions that allow for using simulators to facilitate professional competence from within an educational setting. We develop a generic didactic model that ascribes learning to participation in iterative cycles of action and reflection. The development of this model is motivated by the need to develop an interdisciplinary professional education rooted in the pattern of military practice.
Keywords: Development in higher education, experiential learning, professional education, simulation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1189610 Evaluation of Gasoline Engine Piston with Various Coating Materials Using Finite Element Method
Authors: Nouby Ghazaly, Gamal Fouad, Ali Abd-El-Tawwab, K. A. Abd El-Gwwad
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The purpose of this paper is to examine the piston stress distribution using several thicknesses of the coating materials to achieve higher gasoline engine performance. First of all, finite element structure analysis is used to uncoated petrol piston made of aluminum alloy. Then, steel and cast-iron piston materials are conducted and compared with the aluminum piston. After that, investigation of four coating materials namely, yttria-stabilized zirconia, magnesia-stabilized zirconia, alumina, and mullite are studied for each piston materials. Next, influence of various thickness coating layers on the structure stresses of the top surfaces is examined. Comparison between simulated results for aluminum, steel, and cast-iron materials is reported. Moreover, the influences of different coating thickness on the Von Mises stresses of four coating materials are investigated. From the simulation results, it can report that the maximum Von Mises stresses and deformations for the piston materials are decreasing with increasing the coating thickness for magnesia-stabilized zirconia, yttria-stabilized zirconia, mullite and alumina coated materials.
Keywords: Structure analysis, aluminum piston, MgZrO3, YTZ, mullite and alumina.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 784609 Friction Calculation and Simulation of Column Electric Power Steering System
Authors: Seyed Hamid Mirmohammad Sadeghi, Raffaella Sesana, Daniela Maffiodo
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This study presents a procedure for friction calculation of column electric power steering (C-EPS) system which affects handling and comfort in driving. The friction losses estimation is obtained from experimental tests and mathematical calculation. Parts in C-EPS mainly involved in friction losses are bearings and worm gear. In the theoretical approach, the gear geometry and Hertz law were employed to measure the normal load and the sliding velocity and contact areas from the worm gears driving conditions. The viscous friction generated in the worm gear was obtained with a theoretical approach and the result was applied to model the friction in the steering system. Finally, by viscous friction coefficient and Coulomb friction coefficient, values of friction in worm gear were calculated. According to the Bearing Company and the characteristics of each bearing, the friction torques due to load and due to speed were calculated. A MATLAB Simulink model for calculating the friction in bearings and worm gear in C-EPS were done and the total friction value was estimated.Keywords: Friction, worm gear, column electric power steering system, Simulink, bearing, electric power steering, EPS.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2243608 A Simulated Design and Analysis of a Solar Thermal Parabolic Trough Concentrator
Authors: Fauziah Sulaiman, Nurhayati Abdullah, Balbir Singh Mahinder Singh
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In recent years Malaysia has included renewable energy as an alternative fuel to help in diversifying the country-s energy reliance on oil, natural gas, coal and hydropower with biomass and solar energy gaining priority. The scope of this paper is to look at the designing procedures and analysis of a solar thermal parabolic trough concentrator by simulation utilizing meteorological data in several parts of Malaysia. Parameters which include the aperture area, the diameter of the receiver and the working fluid may be varied to optimize the design. Aperture area is determined by considering the width and the length of the concentrator whereas the geometric concentration ratio (CR) is obtained by considering the width and diameter of the receiver. Three types of working fluid are investigated. Theoretically, concentration ratios can be very high in the range of 10 to 40 000 depending on the optical elements used and continuous tracking of the sun. However, a thorough analysis is essential as discussed in this paper where optical precision and thermal analysis must be carried out to evaluate the performance of the parabolic trough concentrator as the theoretical CR is not the only factor that should be considered.Keywords: Parabolic trough concentrator, Concentration ratio, Intercept factor, Efficiency.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3981607 A Robust Adaptive Congestion Control Strategy for Large Scale Networks with Differentiated Services Traffic
Authors: R. R. Chen, K. Khorasani
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In this paper, a robust decentralized congestion control strategy is developed for a large scale network with Differentiated Services (Diff-Serv) traffic. The network is modeled by a nonlinear fluid flow model corresponding to two classes of traffic, namely the premium traffic and the ordinary traffic. The proposed congestion controller does take into account the associated physical network resource limitations and is shown to be robust to the unknown and time-varying delays. Our proposed decentralized congestion control strategy is developed on the basis of Diff-Serv architecture by utilizing a robust adaptive technique. A Linear Matrix Inequality (LMI) condition is obtained to guarantee the ultimate boundedness of the closed-loop system. Numerical simulation implementations are presented by utilizing the QualNet and Matlab software tools to illustrate the effectiveness and capabilities of our proposed decentralized congestion control strategy.
Keywords: Congestion control, Large scale networks, Decentralized control, Differentiated services traffic, Time-delay systems.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1989606 Auto Tuning PID Controller based on Improved Genetic Algorithm for Reverse Osmosis Plant
Authors: Jin-Sung Kim, Jin-Hwan Kim, Ji-Mo Park, Sung-Man Park, Won-Yong Choe, Hoon Heo
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An optimal control of Reverse Osmosis (RO) plant is studied in this paper utilizing the auto tuning concept in conjunction with PID controller. A control scheme composing an auto tuning stochastic technique based on an improved Genetic Algorithm (GA) is proposed. For better evaluation of the process in GA, objective function defined newly in sense of root mean square error has been used. Also in order to achieve better performance of GA, more pureness and longer period of random number generation in operation are sought. The main improvement is made by replacing the uniform distribution random number generator in conventional GA technique to newly designed hybrid random generator composed of Cauchy distribution and linear congruential generator, which provides independent and different random numbers at each individual steps in Genetic operation. The performance of newly proposed GA tuned controller is compared with those of conventional ones via simulation.Keywords: Genetic Algorithm, Auto tuning, Hybrid random number generator, Reverse Osmosis, PID controller
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3127605 Application and Assessment of Artificial Neural Networks for Biodiesel Iodine Value Prediction
Authors: Raquel M. de Sousa, Sofiane Labidi, Allan Kardec D. Barros, Alex O. Barradas Filho, Aldalea L. B. Marques
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Several parameters are established in order to measure biodiesel quality. One of them is the iodine value, which is an important parameter that measures the total unsaturation within a mixture of fatty acids. Limitation of unsaturated fatty acids is necessary since warming of higher quantity of these ones ends in either formation of deposits inside the motor or damage of lubricant. Determination of iodine value by official procedure tends to be very laborious, with high costs and toxicity of the reagents, this study uses artificial neural network (ANN) in order to predict the iodine value property as an alternative to these problems. The methodology of development of networks used 13 esters of fatty acids in the input with convergence algorithms of back propagation of back propagation type were optimized in order to get an architecture of prediction of iodine value. This study allowed us to demonstrate the neural networks’ ability to learn the correlation between biodiesel quality properties, in this caseiodine value, and the molecular structures that make it up. The model developed in the study reached a correlation coefficient (R) of 0.99 for both network validation and network simulation, with Levenberg-Maquardt algorithm.Keywords: Artificial Neural Networks, Biodiesel, Iodine Value, Prediction.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2380604 Implementation the Average Input Current Mode Control of Two-Phase Interleaved Boost Converter Using Low-Cost Microcontroller
Authors: Yin Yin Phyo, Tun Lin Naing
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In this paper, the average input current mode control is proposed for two-phase interleaved boost converter with two separate input inductors operating in continuous conduction mode (CCM). The required mathematical model is obtained from the equivalent circuits of its different four modes of operation. The small ripple approximation is derived to find the transfer functions from dynamic model using switching function. In average input current mode control, the inner current loop and outer voltage loop are designed with PI controller using bode analysis. Anti-windup structure is applied for PI controllers in control system. Moreover, the simulation work is carried out by MATLAB/Simulink. And, the hardware prototype is implemented by using low-cost microcontroller Arduino Nano. Finally, the laboratory prototype, available from the local market, is constructed to validate the mathematical model. The results show that the output voltage response is the faster rise time and settling time with acceptable overshoot.
Keywords: Average input current mode control, interleaved boost converter, low-cost microcontroller, PI controller, switching function.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1352603 Multi-Rate Exact Discretization based on Diagonalization of a Linear System - A Multiple-Real-Eigenvalue Case
Authors: T. Sakamoto, N. Hori
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A multi-rate discrete-time model, whose response agrees exactly with that of a continuous-time original at all sampling instants for any sampling periods, is developed for a linear system, which is assumed to have multiple real eigenvalues. The sampling rates can be chosen arbitrarily and individually, so that their ratios can even be irrational. The state space model is obtained as a combination of a linear diagonal state equation and a nonlinear output equation. Unlike the usual lifted model, the order of the proposed model is the same as the number of sampling rates, which is less than or equal to the order of the original continuous-time system. The method is based on a nonlinear variable transformation, which can be considered as a generalization of linear similarity transformation, which cannot be applied to systems with multiple eigenvalues in general. An example and its simulation result show that the proposed multi-rate model gives exact responses at all sampling instants.Keywords: Multi-rate discretization, linear systems, triangularization, similarity transformation, diagonalization, exponential transformation, multiple eigenvalues
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1360602 Distributed Cost-Based Scheduling in Cloud Computing Environment
Authors: Rupali, Anil Kumar Jaiswal
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Cloud computing can be defined as one of the prominent technologies that lets a user change, configure and access the services online. it can be said that this is a prototype of computing that helps in saving cost and time of a user practically the use of cloud computing can be found in various fields like education, health, banking etc. Cloud computing is an internet dependent technology thus it is the major responsibility of Cloud Service Providers(CSPs) to care of data stored by user at data centers. Scheduling in cloud computing environment plays a vital role as to achieve maximum utilization and user satisfaction cloud providers need to schedule resources effectively. Job scheduling for cloud computing is analyzed in the following work. To complete, recreate the task calculation, and conveyed scheduling methods CloudSim3.0.3 is utilized. This research work discusses the job scheduling for circulated processing condition also by exploring on this issue we find it works with minimum time and less cost. In this work two load balancing techniques have been employed: ‘Throttled stack adjustment policy’ and ‘Active VM load balancing policy’ with two brokerage services ‘Advanced Response Time’ and ‘Reconfigure Dynamically’ to evaluate the VM_Cost, DC_Cost, Response Time, and Data Processing Time. The proposed techniques are compared with Round Robin scheduling policy.
Keywords: Physical machines, virtual machines, support for repetition, self-healing, highly scalable programming model.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 851601 Coupling Time-Domain Analysis for Dynamic Positioning during S-Lay Installation
Authors: Sun Li-ping, Zhu Jian-xun, Liu Sheng-nan
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In order to study the performance of dynamic positioning system during S-lay operations, dynamic positioning system is simulated with the hull-stinger-pipe coupling effect. The roller of stinger is simulated by the generalized elastic contact theory. The stinger is composed of Morrison members. Force on pipe is calculated by lumped mass method. Time domain of fully coupled barge model is analyzed combining with PID controller, Kalman filter and allocation of thrust using Sequential Quadratic Programming method. It is also analyzed that the effect of hull wave frequency motion on pipe-stinger coupling force and dynamic positioning system. Besides, it is studied that how S-lay operations affect the dynamic positioning accuracy. The simulation results are proved to be available by checking pipe stress with API criterion. The effect of heave and yaw motion cannot be ignored on hull-stinger-pipe coupling force and dynamic positioning system. It is important to decrease the barge’s pitch motion and lay pipe in head sea in order to improve safety of the S-lay installation and dynamic positioning.
Keywords: S-lay operation, dynamic positioning, coupling motion; time domain, allocation of thrust.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2778600 Hydrogen Embrittlement in a Coupled Mass Diffusion with Stress near a Blunting Crack Tip for AISI 4135 Pressure Vessel
Authors: H. Dehghan, E. Mahdavi, M. M. Heyhat
Abstract:
In pressure vessels contain hydrogen, the role of hydrogen will be important because of hydrogen cracking problem. It is difficult to predict what is happened in metallurgical field spite of a lot of studies have been searched. The main role in controlling the mass diffusion as driving force is related to stress. In this study, finite element analysis is implemented to estimate material-s behavior associated with hydrogen embrittlement. For this purpose, one model of a pressure vessel is introduced that it has definite boundary and initial conditions. In fact, finite element is employed to solve the sequentially coupled mass diffusion with stress near a crack front in a pressure vessel. Modeling simulation intergrarnular fracture of AISI 4135 steel due to hydrogen is investigated. So, distribution of hydrogen and stress are obtained and they indicate that their maximum amounts occur near the crack front. This phenomenon is happened exactly the region between elastic and plastic field. Therefore, hydrogen is highly mobile and can diffuse through crystal lattice so that this zone is potential to trap high volume of hydrogen. Consequently, crack growth and fast fracture will be happened.Keywords: Stress Intensity Factor, Mass Diffusion, FEM, Pressure Vessel
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3074599 Effect of Increasing Road Light Luminance on Night Driving Performance of Older Adults
Authors: Said M. Easa, Maureen J. Reed, Frank Russo, Essam Dabbour, Atif Mehmood, Kathryn Curtis
Abstract:
The main objective of this study was to determine if a minimal increase in road light level (luminance) could lead to improved driving performance among older adults. Older, middleaged and younger adults were tested in a driving simulator following vision and cognitive screening. Comparisons were made for the performance of simulated night driving under two road light conditions (0.6 and 2.5 cd/m2). At each light level, the effects of self reported night driving avoidance were examined along with the vision/cognitive performance. It was found that increasing road light level from 0.6 cd/m2 to 2.5 cd/m2 resulted in improved recognition of signage on straight highway segments. The improvement depends on different driver-related factors such as vision and cognitive abilities, and confidence. On curved road sections, the results showed that driver-s performance worsened. It is concluded that while increasing road lighting may be helpful to older adults especially for sign recognition, it may also result in increased driving confidence and thus reduced attention in some driving situations.Keywords: Driving, older adults, night-time, road lighting, attention, simulation, curves, signs.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1847598 Data Mining Approach for Commercial Data Classification and Migration in Hybrid Storage Systems
Authors: Mais Haj Qasem, Maen M. Al Assaf, Ali Rodan
Abstract:
Parallel hybrid storage systems consist of a hierarchy of different storage devices that vary in terms of data reading speed performance. As we ascend in the hierarchy, data reading speed becomes faster. Thus, migrating the application’ important data that will be accessed in the near future to the uppermost level will reduce the application I/O waiting time; hence, reducing its execution elapsed time. In this research, we implement trace-driven two-levels parallel hybrid storage system prototype that consists of HDDs and SSDs. The prototype uses data mining techniques to classify application’ data in order to determine its near future data accesses in parallel with the its on-demand request. The important data (i.e. the data that the application will access in the near future) are continuously migrated to the uppermost level of the hierarchy. Our simulation results show that our data migration approach integrated with data mining techniques reduces the application execution elapsed time when using variety of traces in at least to 22%.Keywords: Data mining, hybrid storage system, recurrent neural network, support vector machine.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1736597 Contribution to the Study and Optimal Exploitation of a Solar Power System for a Semi-Arid Zone (Case Study: Ferkene, Algeria)
Authors: D. Dib, W. Guebabi, M. B. Guesmi
Abstract:
The objective of this paper is a contribution to a study of power supply by solar energy system called a common Ferkène north of Algerian desert in the semi-arid area. The optimal exploitation of the system, goes through stages of study and essential design, the choice of the model of the photovoltaic panel, the study of behavior with all the parameters involved in simulation before fixing the trajectory tracking the maximum point the power to extract (MPPT), form the essential platform to shape the design of the solar system set up to supply the town Ferkène without considering the grid. The identification of the common Ferkène by the collection of geographical, meteorological, demographic and electrical provides a basis uniform and important data. The results reflect a valid fictive model for any attempt to study and design a solar system to supply an arid or semi-arid zone by electrical energy from photovoltaic panels.
Keywords: Solar power, photovoltaic panel, Boost converter, supply, design, electric power, Ferkène, Algeria.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1752