Search results for: realistic simulation
2696 Drift-Wave Turbulence in a Tokamak Edge Plasma
Authors: S. Belgherras Bekkouche, T. Benouaz, S. M. A. Bekkouche
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Tokamak plasma is far from having a stable background. The study of turbulent transport is an important part of the current research and advanced scenarios were devised to minimize it. To do this, we used a three-wave interaction model which allows to investigate the occurrence drift-wave turbulence driven by pressure gradients in the edge plasma of a tokamak. In order to simulate the energy redistribution among different modes, the growth/decay rates for the three waves was added. After a numerical simulation, we can determine certain aspects of the temporal dynamics exhibited by the model. Indeed for a wide range of the wave decay rate, an intermittent transition from periodic behavior to chaos is observed. Then, a control strategy of chaos was introduced with the aim of reducing or eliminating the weak turbulence.Keywords: wave interaction, plasma drift waves, wave turbulence, tokamak, edge plasma, chaos
Procedia PDF Downloads 5522695 Numerical and Experimental Investigation of Air Distribution System of Larder Type Refrigerator
Authors: Funda Erdem Şahnali, Ş. Özgür Atayılmaz, Tolga N. Aynur
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Almost all of the domestic refrigerators operate on the principle of the vapor compression refrigeration cycle and removal of heat from the refrigerator cabinets is done via one of the two methods: natural convection or forced convection. In this study, airflow and temperature distributions inside a 375L no-frost type larder cabinet, in which cooling is provided by forced convection, are evaluated both experimentally and numerically. Airflow rate, compressor capacity and temperature distribution in the cooling chamber are known to be some of the most important factors that affect the cooling performance and energy consumption of a refrigerator. The objective of this study is to evaluate the original temperature distribution in the larder cabinet, and investigate for better temperature distribution solutions throughout the refrigerator domain via system optimizations that could provide uniform temperature distribution. The flow visualization and airflow velocity measurements inside the original refrigerator are performed via Stereoscopic Particle Image Velocimetry (SPIV). In addition, airflow and temperature distributions are investigated numerically with Ansys Fluent. In order to study the heat transfer inside the aforementioned refrigerator, forced convection theories covering the following cases are applied: closed rectangular cavity representing heat transfer inside the refrigerating compartment. The cavity volume has been represented with finite volume elements and is solved computationally with appropriate momentum and energy equations (Navier-Stokes equations). The 3D model is analyzed as transient, with k-ε turbulence model and SIMPLE pressure-velocity coupling for turbulent flow situation. The results obtained with the 3D numerical simulations are in quite good agreement with the experimental airflow measurements using the SPIV technique. After Computational Fluid Dynamics (CFD) analysis of the baseline case, the effects of three parameters: compressor capacity, fan rotational speed and type of shelf (glass or wire) are studied on the energy consumption; pull down time, temperature distributions in the cabinet. For each case, energy consumption based on experimental results is calculated. After the analysis, the main effective parameters for temperature distribution inside a cabin and energy consumption based on CFD simulation are determined and simulation results are supplied for Design of Experiments (DOE) as input data for optimization. The best configuration with minimum energy consumption that provides minimum temperature difference between the shelves inside the cabinet is determined.Keywords: air distribution, CFD, DOE, energy consumption, experimental, larder cabinet, refrigeration, uniform temperature
Procedia PDF Downloads 1092694 Analytical Approximations of the Differential Elastic Scattering Cross-Sections for Slow Electrons and Positrons Transport in Solids: A Comparative Study
Authors: A. Bentabet, A. Aydin, N. Fenineche
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In this work, we try to determine the best analytical approximation of differential cross sections, used generally in Monte Carlo simulation, to study the electron/positron slowing down in solid targets in the energy range up to 10 keV. Actually, our comparative study was carried out on the angular distribution of the scattering angle, the elastic total and the first transport cross sections which are the essential quantities used generally in the electron/positron transport study by using both stochastic and deterministic methods. Indeed, the obtained results using the relativistic partial wave expansion method and the backscattering coefficient experimental data are used as criteria to evaluate the used model.Keywords: differential cross-section, backscattering coefficient, Rutherford cross-section, Vicanek and Urbassek theory
Procedia PDF Downloads 5632693 Simulation and Study of the Effect of Paint Mineral Coating on Energy Saving
Authors: A. A. Azemati, H. Hosseini
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By using an adequate paint in buildings, energy consumption can be decreased. In this research, a range of wall paints in different climatic conditions has been investigated to observe its effect on energy consumption. In the current study, the researchers have investigated the effect of different parameters including climatic condition, absorption coefficient, and thermal loads on paint coating. In order to study these effects, heating and cooling loads of a typical building with different color paints have been calculated. The effect of building paint in different climatic condition was studied and a comparison was drawn between paints and painting coats with inorganic micro particles in temperate climate to obtain optimized energy consumption.Keywords: climate, energy consumption, inorganic, painting coats
Procedia PDF Downloads 2902692 Impact of Mass Customization for 3D Geographic Information Systems under Turbulent Environments
Authors: Abdo Shabah
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Mass customization aims to produce customized goods (allowing economies of scope) at lower cost (to achieve economies of scale) using multiple strategies (modularization and postponement). Through a simulation experiment of organizations under turbulent environment, we aim to compare standardization and mass customization of services and assess the impact of different forms of mass customization (early and late postponement) on performance, quality and consumer satisfaction, on the use of modular dynamic 3D Geographic Information System. Our hypothesis is that mass customization performs better and achieves better quality in turbulent environment than standardization, but only when using early postponement strategies. Using mixed methods study, we try to confirm our hypothesis.Keywords: mass customization, postponement, experiment, performance, quality, satisfaction, 3D GIS
Procedia PDF Downloads 4532691 A Hybrid Method for Determination of Effective Poles Using Clustering Dominant Pole Algorithm
Authors: Anuj Abraham, N. Pappa, Daniel Honc, Rahul Sharma
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In this paper, an analysis of some model order reduction techniques is presented. A new hybrid algorithm for model order reduction of linear time invariant systems is compared with the conventional techniques namely Balanced Truncation, Hankel Norm reduction and Dominant Pole Algorithm (DPA). The proposed hybrid algorithm is known as Clustering Dominant Pole Algorithm (CDPA) is able to compute the full set of dominant poles and its cluster center efficiently. The dominant poles of a transfer function are specific eigenvalues of the state space matrix of the corresponding dynamical system. The effectiveness of this novel technique is shown through the simulation results.Keywords: balanced truncation, clustering, dominant pole, Hankel norm, model reduction
Procedia PDF Downloads 5992690 Optimization Principles of Eddy Current Separator for Mixtures with Different Particle Sizes
Authors: Cao Bin, Yuan Yi, Wang Qiang, Amor Abdelkader, Ali Reza Kamali, Diogo Montalvão
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The study of the electrodynamic behavior of non-ferrous particles in time-varying magnetic fields is a promising area of research with wide applications, including recycling of non-ferrous metals, mechanical transmission, and space debris. The key technology for recovering non-ferrous metals is eddy current separation (ECS), which utilizes the eddy current force and torque to separate non-ferrous metals. ECS has several advantages, such as low energy consumption, large processing capacity, and no secondary pollution, making it suitable for processing various mixtures like electronic scrap, auto shredder residue, aluminum scrap, and incineration bottom ash. Improving the separation efficiency of mixtures with different particle sizes in ECS can create significant social and economic benefits. Our previous study investigated the influence of particle size on separation efficiency by combining numerical simulations and separation experiments. Pearson correlation analysis found a strong correlation between the eddy current force in simulations and the repulsion distance in experiments, which confirmed the effectiveness of our simulation model. The interaction effects between particle size and material type, rotational speed, and magnetic pole arrangement were examined. It offer valuable insights for the design and optimization of eddy current separators. The underlying mechanism behind the effect of particle size on separation efficiency was discovered by analyzing eddy current and field gradient. The results showed that the magnitude and distribution heterogeneity of eddy current and magnetic field gradient increased with particle size in eddy current separation. Based on this, we further found that increasing the curvature of magnetic field lines within particles could also increase the eddy current force, providing a optimized method to improving the separation efficiency of fine particles. By combining the results of the studies, a more systematic and comprehensive set of optimization guidelines can be proposed for mixtures with different particle size ranges. The separation efficiency of fine particles could be improved by increasing the rotational speed, curvature of magnetic field lines, and electrical conductivity/density of materials, as well as utilizing the eddy current torque. When designing an ECS, the particle size range of the target mixture should be investigated in advance, and the suitable parameters for separating the mixture can be fixed accordingly. In summary, these results can guide the design and optimization of ECS, and also expand the application areas for ECS.Keywords: eddy current separation, particle size, numerical simulation, metal recovery
Procedia PDF Downloads 892689 Analysis of Roll-Forming for High-Density Wire of Reed
Authors: Yujeong Shin, Seong Jin Cho, Jin Ho Kim
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In the textile-weaving machine, the reed is the core component to separate thousands of strands of yarn and to produce the fabric in a continuous high-speed movement. In addition, the reed affects the quality of the fiber. Therefore, the wire forming analysis of the main raw materials of the reed needs to be considered. Roll-forming is a key technology among the manufacturing process of reed wire using textile machine. A simulation of roll-forming line in accordance with the reduction rate is performed using LS-DYNA. The upper roller, fixed roller and reed wire are modeled by finite element. The roller is set to be rigid body and the wire of SUS430 is set to be flexible body. We predict the variation of the cross-sectional shape of the wire depending on the reduction ratio.Keywords: textile machine, reed, rolling, reduction ratio, wire
Procedia PDF Downloads 3752688 Non-Linear Control Based on State Estimation for the Convoy of Autonomous Vehicles
Authors: M-M. Mohamed Ahmed, Nacer K. M’Sirdi, Aziz Naamane
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In this paper, a longitudinal and lateral control approach based on a nonlinear observer is proposed for a convoy of autonomous vehicles to follow a desired trajectory. To authors best knowledge, this topic has not yet been sufficiently addressed in the literature for the control of multi vehicles. The modeling of the convoy of the vehicles is revisited using a robotic method for simulation purposes and control design. With these models, a sliding mode observer is proposed to estimate the states of each vehicle in the convoy from the available sensors, then a sliding mode control based on this observer is used to control the longitudinal and lateral movement. The validation and performance evaluation are done using the well-known driving simulator Scanner-Studio. The results are presented for different maneuvers of 5 vehicles.Keywords: autonomous vehicles, convoy, non-linear control, non-linear observer, sliding mode
Procedia PDF Downloads 1412687 Design and Performance Optimization of Isostatic Pressing Working Cylinder Automatic Exhaust Valve
Authors: Wei-Zhao, Yannian-Bao, Xing-Fan, Lei-Cao
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An isostatic pressing working cylinder automatic exhaust valve is designed. The finite element models of valve core and valve body under ultra-high pressure work environment are built to study the influence of interact of valve core and valve body to sealing performance. The contact stresses of metal sealing surface with different sizes are calculated and the automatic exhaust valve is optimized. The result of simulation and experiment shows that the sealing of optimized exhaust valve is more reliable and the service life is greatly improved. The optimized exhaust valve has been used in the warm isostatic pressing equipment.Keywords: exhaust valve, sealing, ultra-high pressure, isostatic pressing
Procedia PDF Downloads 3072686 Solid Particles Transport and Deposition Prediction in a Turbulent Impinging Jet Using the Lattice Boltzmann Method and a Probabilistic Model on GPU
Authors: Ali Abdul Kadhim, Fue Lien
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Solid particle distribution on an impingement surface has been simulated utilizing a graphical processing unit (GPU). In-house computational fluid dynamics (CFD) code has been developed to investigate a 3D turbulent impinging jet using the lattice Boltzmann method (LBM) in conjunction with large eddy simulation (LES) and the multiple relaxation time (MRT) models. This paper proposed an improvement in the LBM-cellular automata (LBM-CA) probabilistic method. In the current model, the fluid flow utilizes the D3Q19 lattice, while the particle model employs the D3Q27 lattice. The particle numbers are defined at the same regular LBM nodes, and transport of particles from one node to its neighboring nodes are determined in accordance with the particle bulk density and velocity by considering all the external forces. The previous models distribute particles at each time step without considering the local velocity and the number of particles at each node. The present model overcomes the deficiencies of the previous LBM-CA models and, therefore, can better capture the dynamic interaction between particles and the surrounding turbulent flow field. Despite the increasing popularity of LBM-MRT-CA model in simulating complex multiphase fluid flows, this approach is still expensive in term of memory size and computational time required to perform 3D simulations. To improve the throughput of each simulation, a single GeForce GTX TITAN X GPU is used in the present work. The CUDA parallel programming platform and the CuRAND library are utilized to form an efficient LBM-CA algorithm. The methodology was first validated against a benchmark test case involving particle deposition on a square cylinder confined in a duct. The flow was unsteady and laminar at Re=200 (Re is the Reynolds number), and simulations were conducted for different Stokes numbers. The present LBM solutions agree well with other results available in the open literature. The GPU code was then used to simulate the particle transport and deposition in a turbulent impinging jet at Re=10,000. The simulations were conducted for L/D=2,4 and 6, where L is the nozzle-to-surface distance and D is the jet diameter. The effect of changing the Stokes number on the particle deposition profile was studied at different L/D ratios. For comparative studies, another in-house serial CPU code was also developed, coupling LBM with the classical Lagrangian particle dispersion model. Agreement between results obtained with LBM-CA and LBM-Lagrangian models and the experimental data is generally good. The present GPU approach achieves a speedup ratio of about 350 against the serial code running on a single CPU.Keywords: CUDA, GPU parallel programming, LES, lattice Boltzmann method, MRT, multi-phase flow, probabilistic model
Procedia PDF Downloads 2072685 Synchronous Generator in Case Voltage Sags for Different Loads
Authors: Benalia Nadia, Bensiali Nadia, Zezouri Noura
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This paper studies the effects of voltage sags, both symmetrical and unsymmetrical, on the three-phase Synchronous Machine (SM) when powering an isolate load or infinite bus bar. The vast majority of the electrical power generation systems in the world is consist of synchronous generators coupled to the electrical network though a transformer. Voltage sags on SM cause speed variations, current and torque peaks and hence may cause tripping and equipment damage. The consequences of voltage sags in the machine behavior depends on different factors such as its magnitude (or depth), duration , the parameters of the machine and also the size of load. In this study, we consider the machine feeds an infinite bus bar in the first and the isolate load using symmetric and asymmetric defaults to see the behavior of the machine in both case the simulation have been used on SIMULINK MATLAB.Keywords: power quality, voltage sag, synchronous generator, infinite system
Procedia PDF Downloads 6792684 Fast Terminal Synergetic Converter Control
Authors: Z. Bouchama, N. Essounbouli, A. Hamzaoui, M. N. Harmas
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A new robust finite time synergetic controller is presented based on recently developed synergetic control methodology and a terminal attractor technique. A Fast Terminal Synergetic Control (FTSC) is proposed for controlling DC-DC buck converter. Unlike Synergetic Control (SC) and sliding mode control, the proposed control scheme has the characteristics of finite time convergence and chattering free phenomena. Simulation of stabilization and reference tracking for buck converter systems illustrates the approach effectiveness while stability is assured in the Lyapunov sense and converse Lyapunov results involving scalar differential inequalities are given for finite-time stability.Keywords: dc-dc buck converter, synergetic control, finite time convergence, terminal synergetic control, fast terminal synergetic control, Lyapunov
Procedia PDF Downloads 4592683 Adolescents' Perspectives on Parental Responses to Teen Dating Violence
Authors: Beverly Black
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Teen dating violence (TDV) is a significant public health problem with severe negative impact on youths’ mental and physical health and well-being. Exacerbating the negative impact of TDV victimization is the fact that teens rarely report the violence. They are fearful to tell friends or family, especially parents. The family context is the first place where children learn about interpersonal relationships, and therefore, parental response of teens’ life experiences influences teens’ actions and development. This study examined youths’ perspectives on parental responses to TDV. Effective parental responses to TDV may increase the likelihood that youth will leave abusive relationships. Method. Eleven gender-separate focus groups were conducted with 27 females and 28 males, ages 12 to 17, to discuss parental responses to teen dating violence. Youth were recruited from a metropolitan community in the southwestern part of the United States. Focus groups questions asked the middle and high school youth how they would want their parents to respond to them if they approached them about various incidents of dating violence. All focus groups were transcribed. Using QSR-N10, two researchers’ analyzed data first using open and axial coding techniques to find overarching themes. Researchers triangulated the coded data to ensure accurate interpretations of the participants’ messages and used the scenario questions to structure the coded results. Results. Most youths suggested that parents should simply talk with them; they recognized the importance of communication. Teens wanted parents to ask questions, educate them about healthy relationships, share their personal experiences, and give teens advice (tell them to break up, limit contact with perpetrator, go to police). Younger youth expressed more willingness to listen to parental advice. Older youth wanted their parents to give them the opportunity to make their decisions. Many of the teens’ comments focused on the importance of parents protecting the teen, providing support and empathy for the teen, and especially refraining from overreacting (not yelling, not getting angry and staying calm). Implications. Parents need to know how to effectively respond to youth needing to leave unhealthy relationships. Demanding that their children end a relationship may not be a realistic approach to TDV. A parent’s ineffective response, when approached by an adolescent for assistance in TDV, may influence a youth to dismiss parents and other adults as viable options for seeking assistance. Parents and prevention educators can learn from hearing youths’ voices about effective responses to TDV.Keywords: adolescents dating abuse, adolescent and parent communication, parental responses to teen dating violence, teen dating violence
Procedia PDF Downloads 2722682 Optimization of Flexible Job Shop Scheduling Problem with Sequence-Dependent Setup Times Using Genetic Algorithm Approach
Authors: Sanjay Kumar Parjapati, Ajai Jain
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This paper presents optimization of makespan for ‘n’ jobs and ‘m’ machines flexible job shop scheduling problem with sequence dependent setup time using genetic algorithm (GA) approach. A restart scheme has also been applied to prevent the premature convergence. Two case studies are taken into consideration. Results are obtained by considering crossover probability (pc = 0.85) and mutation probability (pm = 0.15). Five simulation runs for each case study are taken and minimum value among them is taken as optimal makespan. Results indicate that optimal makespan can be achieved with more than one sequence of jobs in a production order.Keywords: flexible job shop, genetic algorithm, makespan, sequence dependent setup times
Procedia PDF Downloads 3322681 Computational Fluid Dynamics of a Bubbling Fluidized Bed in Wood Pellets
Authors: Opeyemi Fadipe, Seong Lee, Guangming Chen, Steve Efe
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In comparison to conventional combustion technologies, fluidized bed combustion has several advantages, such as superior heat transfer characteristics due to homogeneous particle mixing, lower temperature needs, nearly isothermal process conditions, and the ability to operate continuously. Computational fluid dynamics (CFD) can help anticipate the intricate combustion process and the hydrodynamics of a fluidized bed thoroughly by using CFD techniques. Bubbling Fluidized bed was model using the Eulerian-Eulerian model, including the kinetic theory of the flow. The model was validated by comparing it with other simulation of the fluidized bed. The effects of operational gas velocity, volume fraction, and feed rate were also investigated numerically. A higher gas velocity and feed rate cause an increase in fluidization of the bed.Keywords: fluidized bed, operational gas velocity, volume fraction, computational fluid dynamics
Procedia PDF Downloads 832680 Simplified Analysis on Steel Frame Infill with FRP Composite Panel
Authors: HyunSu Seo, HoYoung Son, Sungjin Kim, WooYoung Jung
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In order to understand the seismic behavior of steel frame structure with infill FRP composite panel, simple models for simulation on the steel frame with the panel systems were developed in this study. To achieve the simple design method of the steel framed structure with the damping panel system, 2-D finite element analysis with the springs and dashpots models was conducted in ABAQUS. Under various applied spring stiffness and dashpot coefficient, the expected hysteretic energy responses of the steel frame with damping panel systems we re investigated. Using the proposed simple design method which decides the stiffness and the damping, it is possible to decide the FRP and damping materials on a steel frame system.Keywords: numerical analysis, FEM, infill, GFRP, damping
Procedia PDF Downloads 4252679 Integrated Power Saving for Multiple Relays and UEs in LTE-TDD
Authors: Chun-Chuan Yang, Jeng-Yueng Chen, Yi-Ting Mai, Chen-Ming Yang
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In this paper, the design of integrated sleep scheduling for relay nodes and user equipments under a Donor eNB (DeNB) in the mode of Time Division Duplex (TDD) in LTE-A is presented. The idea of virtual time is proposed to deal with the discontinuous pattern of the available radio resource in TDD, and based on the estimation of the traffic load, three power saving schemes in the top-down strategy are presented. Associated mechanisms in each scheme including calculation of the virtual subframe capacity, the algorithm of integrated sleep scheduling, and the mapping mechanisms for the backhaul link and the access link are presented in the paper. Simulation study shows the advantage of the proposed schemes in energy saving over the standard DRX scheme.Keywords: LTE-A, relay, TDD, power saving
Procedia PDF Downloads 5162678 Performance Variation of the TEES According to the Changes in Cold-Side Storage Temperature
Authors: Young-Jin Baik, Minsung Kim, Junhyun Cho, Ho-Sang Ra, Young-Soo Lee, Ki-Chang Chang
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Surplus electricity can be converted into potential energy via pumped hydroelectric storage for future usage. Similarly, thermo-electric energy storage (TEES) uses heat pumps equipped with thermal storage to convert electrical energy into thermal energy; the stored energy is then converted back into electrical energy when necessary using a heat engine. The greatest advantage of this method is that, unlike pumped hydroelectric storage and compressed air energy storage, TEES is not restricted by geographical constraints. In this study, performance variation of the TEES according to the changes in cold-side storage temperature was investigated by simulation method.Keywords: energy storage system, heat pump, fluid mechanics, thermodynamics
Procedia PDF Downloads 4822677 Identification of Wiener Model Using Iterative Schemes
Authors: Vikram Saini, Lillie Dewan
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This paper presents the iterative schemes based on Least square, Hierarchical Least Square and Stochastic Approximation Gradient method for the Identification of Wiener model with parametric structure. A gradient method is presented for the parameter estimation of wiener model with noise conditions based on the stochastic approximation. Simulation results are presented for the Wiener model structure with different static non-linear elements in the presence of colored noise to show the comparative analysis of the iterative methods. The stochastic gradient method shows improvement in the estimation performance and provides fast convergence of the parameters estimates.Keywords: hard non-linearity, least square, parameter estimation, stochastic approximation gradient, Wiener model
Procedia PDF Downloads 4052676 Optimization of Slider Crank Mechanism Using Design of Experiments and Multi-Linear Regression
Authors: Galal Elkobrosy, Amr M. Abdelrazek, Bassuny M. Elsouhily, Mohamed E. Khidr
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Crank shaft length, connecting rod length, crank angle, engine rpm, cylinder bore, mass of piston and compression ratio are the inputs that can control the performance of the slider crank mechanism and then its efficiency. Several combinations of these seven inputs are used and compared. The throughput engine torque predicted by the simulation is analyzed through two different regression models, with and without interaction terms, developed according to multi-linear regression using LU decomposition to solve system of algebraic equations. These models are validated. A regression model in seven inputs including their interaction terms lowered the polynomial degree from 3rd degree to 1st degree and suggested valid predictions and stable explanations.Keywords: design of experiments, regression analysis, SI engine, statistical modeling
Procedia PDF Downloads 1862675 A Golay Pair Based Synchronization Algorithm for Distributed Multiple-Input Multiple-Output System
Authors: Weizhi Zhong, Xiaoyi Lu, Lei Xu
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In order to solve the problem of inaccurate synchronization for distributed multiple-input multiple-output (MIMO) system in multipath environment, a golay pair aided timing synchronization method is proposed in this paper. A new synchronous training sequence based on golay pair is designed. By utilizing the aperiodic auto-correlation complementary property of the new training sequence, the fine timing point is obtained at the receiver. Simulation results show that, compared with the tradition timing synchronization approaches, the proposed algorithm can provide high accuracy in synchronization, especially under multipath condition.Keywords: distributed MIMO system, golay pair, multipath, synchronization
Procedia PDF Downloads 2472674 Economic and Technical Study for Hybrid (PV/Wind) Power System in the North East of Algeria
Authors: Nabila Louai, Fouad Khaldi, Houria Benharchache
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In this paper, the case of meeting a household’s electrical energy demand with hybrid systems has been examined. The objective is to study technological feasibility and economic viability of the electrification project by a hybrid system (PV/ wind) of a residential home located in Batna-Algeria and to reduce the emissions from traditional power by using renewable energy. An autonomous hybrid wind/photovoltaic (PV)/battery power system and a PV/Wind grid connected system, has been carried out using Hybrid Optimization Model for Electric Renewable (HOMER) simulation software. As a result, it has been found that electricity from the grid can be supplied at a lower price than electricity from renewable energy at this moment.Keywords: batna, household, hybrid system, renewable energy, techno-economy
Procedia PDF Downloads 6012673 Online Allocation and Routing for Blood Delivery in Conditions of Variable and Insufficient Supply: A Case Study in Thailand
Authors: Pornpimol Chaiwuttisak, Honora Smith, Yue Wu
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Blood is a perishable product which suffers from physical deterioration with specific fixed shelf life. Although its value during the shelf life is constant, fresh blood is preferred for treatment. However, transportation costs are a major factor to be considered by administrators of Regional Blood Centres (RBCs) which act as blood collection and distribution centres. A trade-off must therefore be reached between transportation costs and short-term holding costs. In this paper we propose a number of algorithms for online allocation and routing of blood supplies, for use in conditions of variable and insufficient blood supply. A case study in northern Thailand provides an application of the allocation and routing policies tested. The plan proposed for daily allocation and distribution of blood supplies consists of two components: firstly, fixed routes are determined for the supply of hospitals which are far from an RBC. Over the planning period of one week, each hospital on the fixed routes is visited once. A robust allocation of blood is made to hospitals on the fixed routes that can be guaranteed on a suitably high percentage of days, despite variable supplies. Secondly, a variable daily route is employed for close-by hospitals, for which more than one visit per week may be needed to fulfil targets. The variable routing takes into account the amount of blood available for each day’s deliveries, which is only known on the morning of delivery. For hospitals on the variables routes, the day and amounts of deliveries cannot be guaranteed but are designed to attain targets over the six-day planning horizon. In the conditions of blood shortage encountered in Thailand, and commonly in other developing countries, it is often the case that hospitals request more blood than is needed, in the knowledge that only a proportion of all requests will be met. Our proposal is for blood supplies to be allocated and distributed to each hospital according to equitable targets based on historical demand data, calculated with regard to expected daily blood supplies. We suggest several policies that could be chosen by the decision makes for the daily distribution of blood. The different policies provide different trade-offs between transportation and holding costs. Variations in the costs of transportation, such as the price of petrol, could make different policies the most beneficial at different times. We present an application of the policies applied to a realistic case study in the RBC at Chiang Mai province which is located in Northern region of Thailand. The analysis includes a total of more than 110 hospitals, with 29 hospitals considered in the variable route. The study is expected to be a pilot for other regions of Thailand. Computational experiments are presented. Concluding remarks include the benefits gained by the online methods and future recommendations.Keywords: online algorithm, blood distribution, developing country, insufficient blood supply
Procedia PDF Downloads 3312672 The Re-Emergence of Russia Foreign Policy (Case Study: Middle East)
Authors: Maryam Azish
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Russia, as an emerging global player in recent years, has projected a special place in the Middle East. Despite all the challenges it has faced over the years, it has always considered its presence in various fields with a strategy that has defined its maneuvering power as a level of competition and even confrontation with the United States. Therefore, its current approach is considered important as an influential actor in the Middle East. After the collapse of the Soviet Union, when the Russians withdrew completely from the Middle East, the American scene remained almost unrivaled by the Americans. With the start of the US-led war in Iraq and Afghanistan and the subsequent developments that led to the US military and political defeat, a new chapter in regional security was created in which ISIL and Taliban terrorism went along with the Arab Spring to destabilize the Middle East. Because of this, the Americans took every opportunity to strengthen their military presence. Iraq, Syria and Afghanistan have always been the three areas where terrorism was shaped, and the countries of the region have each reacted to this evil phenomenon accordingly. The West dealt with this phenomenon on a case-by-case basis in the general circumstances that created the fluid situation in the Arab countries and the region. Russian President Vladimir Putin accused the US of falling asleep in the face of ISIS and terrorism in Syria. In fact, this was an opportunity for the Russians to revive their presence in Syria. This article suggests that utilizing the recognition policy along with the constructivism theory will offer a better knowledge of Russia’s endeavors to endorse its international position. Accordingly, Russia’s distinctiveness and its ambitions for a situation of great power have played a vital role in shaping national interests and, subsequently, in foreign policy, in Putin's era in particular. The focal claim of the paper is that scrutinize Russia’s foreign policy with realistic methods cannot be attained. Consequently, with an aim to fill the prevailing vacuum, this study exploits the politics of acknowledgment in the context of constructivism to examine Russia’s foreign policy in the Middle East. The results of this paper show that the key aim of Russian foreign policy discourse, accompanied by increasing power and wealth, is to recognize and reinstate the position of great power in the universal system. The Syrian crisis has created an opportunity for Russia to unite its position in the developing global and regional order after ages of dynamic and prevalent existence in the Middle East as well as contradicting US unilateralism. In the meantime, the writer thinks that the question of identifying Russia’s position in the global system by the West has played a foremost role in serving its national interests.Keywords: constructivism, foreign Policy, middle East, Russia, regionalism
Procedia PDF Downloads 1492671 Simulation of Piezoelectric Laminated Smart Structure under Strong Electric Field
Authors: Shun-Qi Zhang, Shu-Yang Zhang, Min Chen
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Applying strong electric field on piezoelectric actuators, on one hand very significant electroelastic material nonlinear effects will occur, on the other hand piezo plates and shells may undergo large displacements and rotations. In order to give a precise prediction of piezolaminated smart structures under large electric field, this paper develops a finite element (FE) model accounting for both electroelastic material nonlinearity and geometric nonlinearity with large rotations based on the first order shear deformation (FSOD) hypothesis. The proposed FE model is applied to analyze a piezolaminated semicircular shell structure.Keywords: smart structures, piezolamintes, material nonlinearity, strong electric field
Procedia PDF Downloads 4272670 Fabrication of Optical Tissue Phantoms Simulating Human Skin and Their Application
Authors: Jihoon Park, Sungkon Yu, Byungjo Jung
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Although various optical tissue phantoms (OTPs) simulating human skin have been actively studied, their completeness is unclear because skin tissue has the intricate optical property and complicated structure disturbing the optical simulation. In this study, we designed multilayer OTP mimicking skin structure, and fabricated OTP models simulating skin-blood vessel and skin pigmentation in the skin, which are useful in Biomedical optics filed. The OTPs were characterized with the optical property and the cross-sectional structure, and analyzed by using various optical tools such as a laser speckle imaging system, OCT and a digital microscope to show the practicality. The measured optical property was within 5% error, and the thickness of each layer was uniform within 10% error in micrometer scale.Keywords: blood vessel, optical tissue phantom, optical property, skin tissue, pigmentation
Procedia PDF Downloads 4552669 Dual-Network Memory Model for Temporal Sequences
Authors: Motonobu Hattori
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In neural networks, when new patters are learned by a network, they radically interfere with previously stored patterns. This drawback is called catastrophic forgetting. We have already proposed a biologically inspired dual-network memory model which can much reduce this forgetting for static patterns. In this model, information is first stored in the hippocampal network, and thereafter, it is transferred to the neocortical network using pseudo patterns. Because, temporal sequence learning is more important than static pattern learning in the real world, in this study, we improve our conventional dual-network memory model so that it can deal with temporal sequences without catastrophic forgetting. The computer simulation results show the effectiveness of the proposed dual-network memory model.Keywords: catastrophic forgetting, dual-network, temporal sequences, hippocampal
Procedia PDF Downloads 2702668 The Effect of Pulsator on Washing Performance in a Front-Loading Washer
Authors: Eung Ryeol Seo, Hee Tae Lim, Eunsuk Bang, Soon Cheol Kweon, Jeoung-Kyo Jeoung, Ji-Hoon Choic
Abstract:
The object of this study is to investigate the effect of pulsator on washing performance quantitatively for front-loading washer. The front-loading washer with pulsator shows washing performance improvement of 18% and the particle-based body simulation technique has been applied to figure out the relation between washing performance and mechanical forces exerted on textile during washing process. As a result, the mechanical forces, such as collision force and strain force, acting on the textile have turned out to be about twice numerically. The washing performance improvement due to additional pulsate system has been utilized for customers to save 50% of washing time.Keywords: front-loading washer, mechanical force, fabric movement, pulsator, time-saving
Procedia PDF Downloads 2612667 Directionally-Sensitive Personal Wearable Radiation Dosimeter
Authors: Hai Huu Le, Paul Junor, Moshi Geso, Graeme O’Keefe
Abstract:
In this paper, the authors propose a personal wearable directionally-sensitive radiation dosimeter using multiple semiconductor CdZnTe detectors. The proposed dosimeter not only measures the real-time dose rate but also provide the direction of the radioactive source. A linear relationship between radioactive source direction and the radiation intensity measured by each detectors is established and an equation to determine the source direction is derived by the authors. The efficiency and accuracy of the proposed dosimeter is verified by simulation using Geant4 package. Results have indicated that in a measurement duration of about 7 seconds, the proposed dosimeter was able to estimate the direction of a 10μCi 137/55Cs radioactive source to within 2 degrees.Keywords: dose rate, Geant4 package, radiation dosimeter, radioactive source direction
Procedia PDF Downloads 327