Search results for: Economic dispatch problem
4364 Solution of Two-Point Nonlinear Boundary Problems Using Taylor Series Approximation and the Ying Buzu Shu Algorithm
Authors: U. C. Amadi, N. A. Udoh
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One of the major challenges faced in solving initial and boundary problems is how to find approximate solutions with minimal deviation from the exact solution without so much rigor and complications. The Taylor series method provides a simple way of obtaining an infinite series which converges to the exact solution for initial value problems and this method of solution is somewhat limited for a two point boundary problem since the infinite series has to be truncated to include the boundary conditions. In this paper, the Ying Buzu Shu algorithm is used to solve a two point boundary nonlinear diffusion problem for the fourth and sixth order solution and compare their relative error and rate of convergence to the exact solution.
Keywords: Ying Buzu Shu, nonlinear boundary problem, Taylor series algorithm, infinite series.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 4554363 A Linearization and Decomposition Based Approach to Minimize the Non-Productive Time in Transfer Lines
Authors: Hany Osman, M. F. Baki
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We address the balancing problem of transfer lines in this paper to find the optimal line balancing that minimizes the nonproductive time. We focus on the tool change time and face orientation change time both of which influence the makespane. We consider machine capacity limitations and technological constraints associated with the manufacturing process of auto cylinder heads. The problem is represented by a mixed integer programming model that aims at distributing the design features to workstations and sequencing the machining processes at a minimum non-productive time. The proposed model is solved by an algorithm established using linearization schemes and Benders- decomposition approach. The experiments show the efficiency of the algorithm in reaching the exact solution of small and medium problem instances at reasonable time.Keywords: Transfer line balancing, Benders' decomposition, Linearization.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17314362 Application of GAMS and GA in the Location and Penetration of Distributed Generation
Authors: Alireza Dehghani Pilehvarani, Mojtaba Hakimzadeh, Mohammad Jafari Far, Reza Sedaghati
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Distributed Generation (DG) can help in reducing the cost of electricity to the costumer, relieve network congestion and provide environmentally friendly energy close to load centers. Its capacity is also scalable and it provides voltage support at distribution level. Hence, DG placement and penetration level is an important problem for both the utility and DG owner. DG allocation and capacity determination is a nonlinear optimization problem. The objective function of this problem is the minimization of the total loss of the distribution system. Also high levels of penetration of DG are a new challenge for traditional electric power systems. This paper presents a new methodology for the optimal placement of DG and penetration level of DG in distribution system based on General Algebraic Modeling System (GAMS) and Genetic Algorithm (GA).
Keywords: Distributed Generation, Location, Loss Reduction, Distribution Network, GA, GAMS.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 26344361 Relay Node Placement for Connectivity Restoration in Wireless Sensor Networks Using Genetic Algorithms
Authors: Hanieh Tarbiat Khosrowshahi, Mojtaba Shakeri
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Wireless Sensor Networks (WSNs) consist of a set of sensor nodes with limited capability. WSNs may suffer from multiple node failures when they are exposed to harsh environments such as military zones or disaster locations and lose connectivity by getting partitioned into disjoint segments. Relay nodes (RNs) are alternatively introduced to restore connectivity. They cost more than sensors as they benefit from mobility, more power and more transmission range, enforcing a minimum number of them to be used. This paper addresses the problem of RN placement in a multiple disjoint network by developing a genetic algorithm (GA). The problem is reintroduced as the Steiner tree problem (which is known to be an NP-hard problem) by the aim of finding the minimum number of Steiner points where RNs are to be placed for restoring connectivity. An upper bound to the number of RNs is first computed to set up the length of initial chromosomes. The GA algorithm then iteratively reduces the number of RNs and determines their location at the same time. Experimental results indicate that the proposed GA is capable of establishing network connectivity using a reasonable number of RNs compared to the best existing work.
Keywords: Connectivity restoration, genetic algorithms, multiple-node failure, relay nodes, wireless sensor networks.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11034360 Compression and Filtering of Random Signals under Constraint of Variable Memory
Authors: Anatoli Torokhti, Stan Miklavcic
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We study a new technique for optimal data compression subject to conditions of causality and different types of memory. The technique is based on the assumption that some information about compressed data can be obtained from a solution of the associated problem without constraints of causality and memory. This allows us to consider two separate problem related to compression and decompression subject to those constraints. Their solutions are given and the analysis of the associated errors is provided.Keywords: stochastic signals, optimization problems in signal processing.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13314359 The Strategy for Increasing the Competitiveness of Georgia
Authors: G. Erkomaishvili
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The paper discusses economic policy of Georgia aiming to increase national competitiveness as well as the tools and means which will help to improve the competitiveness of the country. The sectors of the economy, in which the country can achieve the competitive advantage, are studied. It is noted that the country’s economic policy plays an important role in obtaining and maintaining the competitive advantage - authority should take measures to ensure high level of education; scientific and research activities should be funded by the state; foreign direct investments should be attracted mainly in science-intensive industries; adaptation with the latest scientific achievements of the modern world and deepening of scientific and technical cooperation. Stable business environment and export oriented strategy is the basis for the country’s economic growth. As the outcome of the research, the paper suggests the strategy for improving competitiveness in Georgia; recommendations are provided based on relevant conclusions.
Keywords: Competitive advantage, competitiveness, competitiveness improvement strategy, competitiveness of Georgia.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18944358 Automated Ranking of Hints
Authors: Sylvia Encheva
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The importance of hints in an intelligent tutoring system is well understood. The problems however related to their delivering are quite a few. In this paper we propose delivering of hints to be based on considering their usefulness. By this we mean that a hint is regarded as useful to a student if the student has succeeded to solve a problem after the hint was suggested to her/him. Methods from the theory of partial orderings are further applied facilitating an automated process of offering individualized advises on how to proceed in order to solve a particular problem.
Keywords: Decision support services, uncertainty management, partial orderings.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14914357 Mega Projects and Governmentality
Authors: Sophie Sturup
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Mega urban transport projects (MUTPs) are increasingly being used in urban environments to ameliorate the problem of congestion. However, a number of problems with regard to mega projects have been identified. In particular the seemingly institutionalised over estimation of economic benefits and persistent cost over runs, could mean that the wrong projects are selected, and that the projects that are selected cost more than they should. Studies to date have produced a number of solutions to these problems, perhaps most notably, the various methods for the inclusion of the private sector in project provision. However the problems have shown significant intractability in the face of these solutions. This paper provides a detailed examination of some of the problems facing mega projects and then examines Foucault-s theory of 'governmentality' as a possible frame of analysis which might shed light on the intractability of the problems that have been identified, through an identification of the art of government in which MUTPs occur.Keywords: Michel Foucault, Governmentality, Mega projects, Transport.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24864356 Fuzzy C-Means Clustering Algorithm for Voltage Stability in Large Power Systems
Authors: Mohamad R. Khaldi, Christine S. Khoury, Guy M. Naim
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The steady-state operation of maintaining voltage stability is done by switching various controllers scattered all over the power network. When a contingency occurs, whether forced or unforced, the dispatcher is to alleviate the problem in a minimum time, cost, and effort. Persistent problem may lead to blackout. The dispatcher is to have the appropriate switching of controllers in terms of type, location, and size to remove the contingency and maintain voltage stability. Wrong switching may worsen the problem and that may lead to blackout. This work proposed and used a Fuzzy CMeans Clustering (FCMC) to assist the dispatcher in the decision making. The FCMC is used in the static voltage stability to map instantaneously a contingency to a set of controllers where the types, locations, and amount of switching are induced.Keywords: Fuzzy logic, Power system control, Reactive power control, Voltage control
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18854355 Optimal Type and Installation Time of Wind Farm in a Power System, Considering Service Providers
Authors: M. H. Abedi, A. Jalilvand
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The economic development benefits of wind energy may be the most tangible basis for the local and state officials’ interests. In addition to the direct salaries associated with building and operating wind projects, the wind energy industry provides indirect jobs and benefits. The optimal planning of a wind farm is one most important topic in renewable energy technology. Many methods have been implemented to optimize the cost and output benefit of wind farms, but the contribution of this paper is mentioning different types of service providers and also time of installation of wind turbines during planning horizon years. Genetic algorithm (GA) is used to optimize the problem. It is observed that an appropriate layout of wind farm can cause to minimize the different types of cost.Keywords: Renewable energy, wind farm, optimization, planning.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11384354 Techno-Economic Prospects of High Wind Energy Share in Remote vs. Interconnected Island Grids
Authors: Marina Kapsali, John S. Anagnostopoulos
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On the basis of comparative analysis of alternative “development scenarios” for electricity generation, the main objective of the present study is to investigate the techno-economic viability of high wind energy (WE) use at the local (island) level. An integrated theoretical model is developed based on first principles assuming two main possible scenarios for covering future electrification needs of a medium–sized Greek island, i.e. Lesbos. The first scenario (S1), assumes that the island will keep using oil products as the main source for electricity generation. The second scenario (S2) involves the interconnection of the island with the mainland grid to satisfy part of the electricity demand, while remarkable WE penetration is also achieved. The economic feasibility of the above solutions is investigated in terms of determining their Levelized Cost of Energy (LCOE) for the time-period 2020-2045, including also a sensitivity analysis on the worst/reference/best Cases. According to the results obtained, interconnection of Lesbos Island with the mainland grid (S2) presents considerable economic interest in comparison to autonomous development (S1) with WE having a prominent role to this effect.
Keywords: Electricity generation cost, levelized cost of energy, mainland, wind energy surplus.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10724353 A Novel Pareto-Based Meta-Heuristic Algorithm to Optimize Multi-Facility Location-Allocation Problem
Authors: Vahid Hajipour, Samira V. Noshafagh, Reza Tavakkoli-Moghaddam
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This article proposes a novel Pareto-based multiobjective meta-heuristic algorithm named non-dominated ranking genetic algorithm (NRGA) to solve multi-facility location-allocation problem. In NRGA, a fitness value representing rank is assigned to each individual of the population. Moreover, two features ranked based roulette wheel selection including select the fronts and choose solutions from the fronts, are utilized. The proposed solving methodology is validated using several examples taken from the specialized literature. The performance of our approach shows that NRGA algorithm is able to generate true and well distributed Pareto optimal solutions.
Keywords: Non-dominated ranking genetic algorithm, Pareto solutions, Multi-facility location-allocation problem.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21704352 Optimization of Transfer Pricing in a Recession with Reflection on Croatian Situation
Authors: Jasminka Radolović
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Countries in recession, among them Croatia, have lower tax revenues as a result of unfavorable economic situation, which is decrease of the economic activities and unemployment. The global tax base has decreased. In order to create larger state revenues, states use the institute of tax authorities. By controlling transfer pricing in the international companies and using certain techniques, tax authorities can create greater tax obligations for the companies in a short period of time.Keywords: Documentation, Methods, Tax Optimization, Transfer Pricing
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14914351 Performance and Economic Evaluation of a Hybrid Photovoltaic/Thermal Solar System in Northern China
Authors: E. Sok, Y. Zhuo, S. Wang
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A hybrid Photovoltaic/Thermal (PV/T) solar system integrates photovoltaic and solar thermal technologies into one single solar energy device, with dual generation of electricity and heat energy. The aim of the present study is to evaluate the potential for introduction of the PV/T technology into Northern China. For this purpose, outdoor experiments were conducted on a prototype of a PV/T water-heating system. The annual thermal and electrical performances were investigated under the climatic conditions of Beijing. An economic analysis of the system was then carried out, followed by a sensitivity study. The analysis revealed that the hybrid system is not economically attractive with the current market and energy prices. However, considering the continuous commitment of the Chinese government towards policy development in the renewable energy sector, and technological improvements like the increasing cost-effectiveness of PV cells, PV/Thermal technology may become economically viable in the near future.
Keywords: Hybrid Photovoltaic/Thermal (PV/T), Solar energy, Economic analysis
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23614350 A Comparative Analysis of Insolvency Proceedings in France, Germany and Slovak Republic
Authors: Zuzana Crhová, Marie Paseková
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This contribution aims to compare legislation adjusting the course of insolvency proceedings in France, Germany and Slovakia. On the basis of an investigation of the legislative adjustment of this problem, an attempt is made to ascertain in the given countries the extent to which the outcome of the entire proceedings is influenced by legislation and to determine the fundamental moments that influence costs, recovery rate and the duration of proceedings. A comparative analysis was utilized in order to achieve the set goal. The results of the survey could be used to improve legislation so as to lead in the best and most expedient way to a departure from the market of those subjects that are for economic reasons unable to continue with their activities whilst burdening the entire process with the lowest possible costs, which would lead to a high level of satisfaction for creditors.
Keywords: Costs, Insolvency Proceeding, Recovery Rate, Time.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 27714349 On a Way for Constructing Numerical Methods on the Joint of Multistep and Hybrid Methods
Authors: G.Mehdiyeva, M.Imanova, V.Ibrahimov
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Taking into account that many problems of natural sciences and engineering are reduced to solving initial-value problem for ordinary differential equations, beginning from Newton, the scientists investigate approximate solution of ordinary differential equations. There are papers of different authors devoted to the solution of initial value problem for ODE. The Euler-s known method that was developed under the guidance of the famous scientists Adams, Runge and Kutta is the most popular one among these methods. Recently the scientists began to construct the methods preserving some properties of Adams and Runge-Kutta methods and called them hybrid methods. The constructions of such methods are investigated from the middle of the XX century. Here we investigate one generalization of multistep and hybrid methods and on their base we construct specific methods of accuracy order p = 5 and p = 6 for k = 1 ( k is the order of the difference method).Keywords: Multistep and hybrid methods, initial value problem, degree and stability of hybrid methods
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15974348 GPS Signal Correction to Improve Vehicle Location during Experimental Campaign
Authors: L. Della Ragione, G. Meccariello
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In recent years in Italy the progress of the automobile industry, in the field of reduction of emissions values, is very remarkable. Nevertheless their evaluation and reduction is a key problem, especially in the cities, that account for more than 50% of world population. In this paper we dealt with the problem of describing a quantitatively approach for the reconstruction of GPS coordinates and altitude, in the context of correlation study between driving cycles / emission / geographical location, during an experimental campaign realized with some instrumented cars.
Keywords: Air pollution, Driving cycles, GPS signal.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19134347 A Fault Tolerant Token-based Algorithm for Group Mutual Exclusion in Distributed Systems
Authors: Abhishek Swaroop, Awadhesh Kumar Singh
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The group mutual exclusion (GME) problem is a variant of the mutual exclusion problem. In the present paper a token-based group mutual exclusion algorithm, capable of handling transient faults, is proposed. The algorithm uses the concept of dynamic request sets. A time out mechanism is used to detect the token loss; also, a distributed scheme is used to regenerate the token. The worst case message complexity of the algorithm is n+1. The maximum concurrency and forum switch complexity of the algorithm are n and min (n, m) respectively, where n is the number of processes and m is the number of groups. The algorithm also satisfies another desirable property called smooth admission. The scheme can also be adapted to handle the extended group mutual exclusion problem.Keywords: Dynamic request sets, Fault tolerance, Smoothadmission, Transient faults.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16734346 Process of Revitalization of the City Centers in Poland: The Problem of Cooperation between Sectors
Authors: Ewa M. Boryczka
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Contemporary city is a subject to rapid economic and social changes. Therefore, it requires an active policy designed to meet the diverse needs of their residents, build competitive position and capacity to compete with other cities. Competitiveness of cities depends largely on their resources but also to a large extent, on the policies and performance of local authorities. Cooperation with social sector also plays an important role, as it affects the use of resources and builds an advantage over other cities. The subject of this article is city's contemporary problems of development with particular emphasis on central areas. This issue is a starting point for reflection on the process of urban regeneration in medium size cities in Poland, as well as cooperation between various actors and their roles in the revitalization processes of Polish cities' centers.
Keywords: City, cooperation between sectors, crisis of city centers, revitalization.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16534345 An Intelligent Optimization Model for Multi-objective Order Allocation Planning
Authors: W. K. Wong, Z. X. Guo, P.Y. Mok
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This paper presents a multi-objective order allocation planning problem with the consideration of various real-world production features. A novel hybrid intelligent optimization model, integrating a multi-objective memetic optimization process, a Monte Carlo simulation technique and a heuristic pruning technique, is proposed to handle this problem. Experiments based on industrial data are conducted to validate the proposed model. Results show that (1) the proposed model can effectively solve the investigated problem by providing effective production decision-making solutions, which outperformsan NSGA-II-based optimization process and an industrial method.Keywords: Multi-objective order allocation planning, Pareto optimization, Memetic algorithm, Mento Carlo simulation
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16394344 A Post Keynesian Environmental Macroeconomic Model for Agricultural Water Sustainability under Climate Change in the Murray-Darling Basin, Australia
Authors: Ke Zhao, Ballarat Colin Richardson, Jerry Courvisanos, John Crawford
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Climate change has profound consequences for the agriculture of south-eastern Australia and its climate-induced water shortage in the Murray-Darling Basin. Post Keynesian Economics (PKE) macro-dynamics, along with Kaleckian investment and growth theory, are used to develop an ecological-economic system dynamics model of this complex nonlinear river basin system. The Murray- Darling Basin Simulation Model (MDB-SM) uses the principles of PKE to incorporate the fundamental uncertainty of economic behaviors of farmers regarding the investments they make and the climate change they face, particularly as regards water ecosystem services. MDB-SM provides a framework for macroeconomic policies, especially for long-term fiscal policy and for policy directed at the sustainability of agricultural water, as measured by socio-economic well-being considerations, which include sustainable consumption and investment in the river basin. The model can also reproduce other ecological and economic aspects and, for certain parameters and initial values, exhibit endogenous business cycles and ecological sustainability with realistic characteristics. Most importantly, MDBSM provides a platform for the analysis of alternative economic policy scenarios. These results reveal the importance of understanding water ecosystem adaptation under climate change by integrating a PKE macroeconomic analytical framework with the system dynamics modelling approach. Once parameterised and supplied with historical initial values, MDB-SM should prove to be a practical tool to provide alternative long-term policy simulations of agricultural water and socio-economic well-being.
Keywords: Agricultural water, Macroeconomic dynamics, Modeling, Investment dynamics, Sustainability, Unemployment, Economics, Keynesian, Kaleckian.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21734343 Mechanical Quadrature Methods for Solving First Kind Boundary Integral Equations of Stationary Stokes Problem
Authors: Xin Luo, Jin Huang, Pan Cheng
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By means of Sidi-Israeli’s quadrature rules, mechanical quadrature methods (MQMs) for solving the first kind boundary integral equations (BIEs) of steady state Stokes problem are presented. The convergence of numerical solutions by MQMs is proved based on Anselone’s collective compact and asymptotical compact theory, and the asymptotic expansions with the odd powers of the errors are provided, which implies that the accuracy of the approximations by MQMs possesses high accuracy order O (h3). Finally, the numerical examples show the efficiency of our methods.
Keywords: Stokes problem, boundary integral equation, mechanical quadrature methods, asymptotic expansions.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13984342 Controllability of Efficiency of Antiviral Therapy in Hepatitis B Virus Infections
Authors: Shyam S.N. Perera
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An optimal control problem for a mathematical model of efficiency of antiviral therapy in hepatitis B virus infections is considered. The aim of the study is to control the new viral production, block the new infection cells and maintain the number of uninfected cells in the given range. The optimal controls represent the efficiency of antiviral therapy in inhibiting viral production and preventing new infections. Defining the cost functional, the optimal control problem is converted into the constrained optimization problem and the first order optimality system is derived. For the numerical simulation, we propose the steepest descent algorithm based on the adjoint variable method. A computer program in MATLAB is developed for the numerical simulations.
Keywords: Virus infection model, Optimal control, Adjoint system, Steepest descent
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12534341 Behrens-Fisher Problem with One Variance Unknown
Authors: Sa-aat Niwitpong, Rada Somkhuean, Suparat Niwitpong
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This paper presents the generalized p-values for testing the Behrens-Fisher problem when one variance is unknown. We also derive a closed form expression of the upper bound of the proposed generalized p-value.
Keywords: Generalized p-value, hypothesis testing, upper bound.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14574340 Optimal Design of UPFC Based Damping Controller Using Iteration PSO
Authors: Amin Safari, Hossein Shayeghi
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This paper presents a novel approach for tuning unified power flow controller (UPFC) based damping controller in order to enhance the damping of power system low frequency oscillations. The design problem of damping controller is formulated as an optimization problem according to the eigenvalue-based objective function which is solved using iteration particle swarm optimization (IPSO). The effectiveness of the proposed controller is demonstrated through eigenvalue analysis and nonlinear time-domain simulation studies under a wide range of loading conditions. The simulation study shows that the designed controller by IPSO performs better than CPSO in finding the solution. Moreover, the system performance analysis under different operating conditions show that the δE based controller is superior to the mB based controller.
Keywords: UPFC, Optimization Problem, Iteration ParticleSwarm Optimization, Damping Controller, Low FrequencyOscillations.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18044339 Optimal Risk Reduction in the Railway Industry by Using Dynamic Programming
Authors: Michael Todinov, Eberechi Weli
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The paper suggests for the first time the use of dynamic programming techniques for optimal risk reduction in the railway industry. It is shown that by using the concept ‘amount of removed risk by a risk reduction option’, the problem related to optimal allocation of a fixed budget to achieve a maximum risk reduction in the railway industry can be reduced to an optimisation problem from dynamic programming. For n risk reduction options and size of the available risk reduction budget B (expressed as integer number), the worst-case running time of the proposed algorithm is O (n x (B+1)), which makes the proposed method a very efficient tool for solving the optimal risk reduction problem in the railway industry.
Keywords: Optimisation, railway risk reduction, budget constraints, dynamic programming.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21804338 An Improved Method to Compute Sparse Graphs for Traveling Salesman Problem
Authors: Y. Wang
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The Traveling salesman problem (TSP) is NP-hard in combinatorial optimization. The research shows the algorithms for TSP on the sparse graphs have the shorter computation time than those for TSP according to the complete graphs. We present an improved iterative algorithm to compute the sparse graphs for TSP by frequency graphs computed with frequency quadrilaterals. The iterative algorithm is enhanced by adjusting two parameters of the algorithm. The computation time of the algorithm is O(CNmaxn2) where C is the iterations, Nmax is the maximum number of frequency quadrilaterals containing each edge and n is the scale of TSP. The experimental results showed the computed sparse graphs generally have less than 5n edges for most of these Euclidean instances. Moreover, the maximum degree and minimum degree of the vertices in the sparse graphs do not have much difference. Thus, the computation time of the methods to resolve the TSP on these sparse graphs will be greatly reduced.
Keywords: Frequency quadrilateral, iterative algorithm, sparse graph, traveling salesman problem.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10104337 Nonlinear Model Predictive Swing-Up and Stabilizing Sliding Mode Controllers
Authors: S. Kahvecioglu, A. Karamancioglu, A. Yazici
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In this paper, a nonlinear model predictive swing-up and stabilizing sliding controller is proposed for an inverted pendulum-cart system. In the swing up phase, the nonlinear model predictive control is formulated as a nonlinear programming problem with energy based objective function. By solving this problem at each sampling instant, a sequence of control inputs that optimize the nonlinear objective function subject to various constraints over a finite horizon are obtained. Then, this control drives the pendulum to a predefined neighborhood of the upper equilibrium point, at where sliding mode based model predictive control is used to stabilize the systems with the specified constraints. It is shown by the simulations that, due to the way of formulating the problem, short horizon lengths are sufficient for attaining the swing up goal.Keywords: Inverted pendulum, model predictive control, swingup, stabilization.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21934336 Optimization of Energy Consumption in Sequential Distillation Column
Authors: M.E. Masoumi, S. Kadkhodaie
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Distillation column is one of the most common operations in process industries and is while the most expensive unit of the amount of energy consumption. Many ideas have been presented in the related literature for optimizing energy consumption in distillation columns. This paper studies the different heat integration methods in a distillation column which separate Benzene, Toluene, Xylene, and C9+. Three schemes of heat integration including, indirect sequence (IQ), indirect sequence with forward energy integration (IQF), and indirect sequence with backward energy integration (IQB) has been studied in this paper. Using shortcut method these heat integration schemes were simulated with Aspen HYSYS software and compared with each other with regarding economic considerations. The result shows that the energy consumption has been reduced 33% in IQF and 28% in IQB in comparison with IQ scheme. Also the economic result shows that the total annual cost has been reduced 12% in IQF and 8% in IQB regarding with IQ scheme. Therefore, the IQF scheme is most economic than IQB and IQ scheme.Keywords: Optimization, Distillation Column Sequence, Energy Savings
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 30154335 A Family of Distributions on Learnable Problems without Uniform Convergence
Authors: César Garza
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In supervised binary classification and regression problems, it is well-known that learnability is equivalent to uniform convergence of the hypothesis class, and if a problem is learnable, it is learnable by empirical risk minimization. For the general learning setting of unsupervised learning tasks, there are non-trivial learning problems where uniform convergence does not hold. We present here the task of learning centers of mass with an extra feature that “activates” some of the coordinates over the unit ball in a Hilbert space. We show that the learning problem is learnable under a stable RLM rule. We introduce a family of distributions over the domain space with some mild restrictions for which the sample complexity of uniform convergence for these problems must grow logarithmically with the dimension of the Hilbert space. If we take this dimension to infinity, we obtain a learnable problem for which the uniform convergence property fails for a vast family of distributions.
Keywords: Statistical learning theory, learnability, uniform convergence, stability, regularized loss minimization.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 354