Rolling of thin gauge hot rolled (HR) coils demands stringent flatness tolerance. Thin HR coils (<= 3 mm) are rolled towards the end of any rolling campaign. The profile and flatness of the strip depend on the prof...
详细信息
Rolling of thin gauge hot rolled (HR) coils demands stringent flatness tolerance. Thin HR coils (<= 3 mm) are rolled towards the end of any rolling campaign. The profile and flatness of the strip depend on the profile of the loaded roll gap in the mill stands. There are five key factors that influence the loaded roll gap: initial roll surface profile, roll thermal expansion, wear of roll, deflection of roll stack and shifting of work rolls. This paper deals with all these factors individually for the formulation of an objective function in order to minimise the flatness error. The shifting and bending of rolls are the controllable parameters that require optimising. This has been accomplished using a geneticalgorithm (GA) optimisation technique.
For satisfactory performance of rolling element bearings, they must be designed for long fatigue life. As the fatigue life of the bearings is directly affected by its dynamic capacity, therefore the latter has been ch...
详细信息
For satisfactory performance of rolling element bearings, they must be designed for long fatigue life. As the fatigue life of the bearings is directly affected by its dynamic capacity, therefore the latter has been chosen as an objective function, which is to be optimized using a robust design optimization. Robust design improves the quality of a product by optimising its mean performance and minimising variation in its performance that incurred due to uncertainties present with the product. Also at the same time, it maintains the design feasibility under realistic and probabilistic constraints. The uncertainties considered in this bearing design problem is the tolerance in bearing dimensions since bearings cannot be manufactured with the exact dimension. In this work, tapered roller bearings has been designed in such a way that it will have maximum dynamic capacity but along with it, it will have minimum variation in its dynamic capacity due to variation in basic dimensions. Therefore, objective of the problem is not to only maximize the dynamic capacity but also to minimise its variation to an extent level. A nonlinear constrained optimization problem has been formulated with single objective function, thirty realistic constraints and eleven design variables. Constraints are basically based on geometrical parameters and strength criterion. Out of total eleven design variables, five are geometrical parameters that directly affect the dynamic capacity and six are constraints parameters, which present in the constraints and affects the possible feasible design space. real coded genetic algorithm has been used as an optimization tool and the result obtained are compared with the standard bearings in catalogue and that are indicating a drastic improvement in the bearing life. Their life is found to be on an average 1.5 times of the life of standard bearings in catalogues. A constraints violation study has been carried out to prioritise the constraints for faster conver
The design problem of imposing deeper nulls in the interference direction of uniform linear antenna arrays under the constraints of a reduced side lobe level (SLL) and a fixed first null beam width (FNBW) is modeled a...
详细信息
The design problem of imposing deeper nulls in the interference direction of uniform linear antenna arrays under the constraints of a reduced side lobe level (SLL) and a fixed first null beam width (FNBW) is modeled as a simple optimization problem. The real-codedgeneticalgorithm (RGA) is used to determine an optimal set of current excitation weights of the antenna elements and the optimum inter-element spacing that satisfies the design goal. Three design examples are presented to illustrate the use of the RGA, and the optimization goal in each example is easily achieved. The numerical results demonstrate the effectiveness of the proposed method. (C) 2013 Production and hosting by Elsevier B.V. on behalf of King Saud University.
This paper presents an optimal thinning of a large multiple concentric circular ring arrays of uniformly excited isotropic antennas based on Particle Swarm Optimization method. Circular Antenna Array (CAA) has gained ...
详细信息
This paper presents an optimal thinning of a large multiple concentric circular ring arrays of uniformly excited isotropic antennas based on Particle Swarm Optimization method. Circular Antenna Array (CAA) has gained immense popularity in the field of communications nowadays. It has proved to be a better alternative over other types of antenna array configuration due to its all-azimuth scan capability, and the beam pattern which can be kept invariant. In this paper, a 9 ringed Concentric Circular Antenna Array (CCAA) with central element feeding is considered. Extensive simulation results justify the optimization efficacy of the proposed approach for antenna array synthesis. The simulation results show that the number of effective antenna elements can be brought down from 279 to 139 with simultaneous reduction in Side Lobe Level by 20.37 dB relative to the main beam with a fixed half power beamwidth using PSO. real coded genetic algorithm (RGA) as well is also adopted to compare the results of PSO algorithm.
In this paper, a real time implementation of selective harmonic elimination pulse width modulation (SHEPWM) using a new technique known as Linearization Method for single phase Matrix converter (SPMC) is designed and ...
详细信息
In this paper, a real time implementation of selective harmonic elimination pulse width modulation (SHEPWM) using a new technique known as Linearization Method for single phase Matrix converter (SPMC) is designed and discussed. SHEPWM for SPMC is designed using real coded genetic algorithm (RGA), particle swarm optimization (PSO) and firefly algorithm (FFA). From the switching angle trajectory of these techniques, the trajectory of LM is designed. In the proposed technique, the optimum switching angles are obtained using simple mathematical calculations. A MATLAB simulation was carried out and FFT analysis of the simulated output voltage waveform confirms the effectiveness of the proposed method. An experimental setup was also developed and the switching angles and firing pulses are generated using Field Programmable Gate Array processor. The proposed method proves that it is much applicable in the industrial applications by virtue of its suitability in real time applications.
This paper presents two areas of studies of embedded generation (EG) viz. optimal allocation and contingency analysis. The paper is started by introducing a method that uses real code geneticalgorithm technique to al...
详细信息
This paper presents two areas of studies of embedded generation (EG) viz. optimal allocation and contingency analysis. The paper is started by introducing a method that uses real code geneticalgorithm technique to allocate the location and the size of EG in distribution system. It follows by the evaluation of the impact of the location and size of EG to the system. The analysis will cover before and after the contingency is created in the system due to fault. The allocation method and contingency analysis study are demonstrated using 24 bus and IEEE 69-bus radial distribution systems.
Software effort estimation is one of the most important tasks in software project management. Of several techniques suggested for estimating software development effort, the analogy-based reasoning, or Case-Based Reas...
详细信息
Software effort estimation is one of the most important tasks in software project management. Of several techniques suggested for estimating software development effort, the analogy-based reasoning, or Case-Based Reasoning (CBR), approaches stand out as promising techniques. In this paper, the benefits of using linguistic rather than numerical values in the analogy process for software effort estimation are investigated. The performance, in terms of accuracy and tolerance of imprecision, of two analogy-based software effort estimation models (Classical Analogy and Fuzzy Analogy, which use numerical and linguistic values respectively to describe software projects) is compared. Three research questions related to the performance of these two models are discussed and answered. This study uses the International Software Benchmarking Standards Group (ISBSG) dataset and confirms the usefulness of using linguistic instead of numerical values in analogy-based software effort estimation models.
A geneticalgorithm (GA)for parameteroptimization of PID sliding mode load frequency contrl used inAutomatic Generating Control (AGC)of multiarea powersystems with nonlinear elements has been proposed. Themethod has t...
详细信息
A geneticalgorithm (GA)for parameteroptimization of PID sliding mode load frequency contrl used inAutomatic Generating Control (AGC)of multiarea powersystems with nonlinear elements has been proposed. Themethod has the advantages of both PID and sliding mode *** of using traditional anaiysis algorithm to obtain thecontroller parameters, GA optimization technology is *** parameter optimization for the interconnection of the AGCloops using MATLAB/Simulink modal is developed. A realcodedgeneticalgorithm is adopted and integrated intoMATLAB/Simulink. The simrlation of a two-area powersystems with PI and PID controllers is reported and the resultsare reasonable.
This paper deals with the application of lattice wave digital filter (LWDF) (3rd and 5th order) for obtaining an efficient design of a Fractional Delay Filter (FDF). The real coded genetic algorithm (RCGA) and Cuckoo ...
详细信息
ISBN:
(纸本)9781467385886
This paper deals with the application of lattice wave digital filter (LWDF) (3rd and 5th order) for obtaining an efficient design of a Fractional Delay Filter (FDF). The real coded genetic algorithm (RCGA) and Cuckoo Search algorithm (CSA) have been used in order to determine the optimal coefficient values of LWDF in order to meet the ideal frequency response characteristics. The simulation of FDF using LWDF structure improves the accuracy of design because of its excellent properties and also it needs only N number of multiplier coefficients for N~(th) order FDF. The simulation results of lattice wave digital Fractional delay filter (LWDFDF) are compared with infinite impulse response-fractional delay filter (IIR-FDF), also designed using RCGA and CSA and it is seen that LWDF based FD filter is superior to the IIR design.
暂无评论