The Selection of the Optimal Solution for SHEPWM under the Influence of IGBT's Manufacturing Technology and Power Losses

2012 ◽  
Vol 548 ◽  
pp. 560-565
Author(s):  
Yu Han Zhang ◽  
An Dong Lang

The paper proposes a method for the selection of the optimal solution among different feasible solutions of the SHEPWM nonlinear model. The method regards the power losses of the switching devices as a criterion for evaluating the possible groups of solutions. The overall power losses are calculated under each combination of the switching angles at first. The variation track of the power losses that could determine the optimal solution under the specific value of m is presented later. The simulation results contrast the new method with the traditional THD method. A comprehensive evaluation considering both methods was concluded at last.

2018 ◽  
Vol 18 (1) ◽  
pp. 13
Author(s):  
Yulia Dewi Regita ◽  
Kiswara Agung Santoso ◽  
Ahmad Kamsyakawuni

Optimization problems are often found in everyday life, such as when determining goods to be a limited storage media. This causes the need for the selection of goods in order to obtain profits with the requirements met. This problem in mathematics is usually called a knapsack. Knapsack problem itself has several variations, in this study knapsack type used is multiple constraints knapsack 0-1 which is solved using the Elephant Herding Optimization (EHO) algorithm. The aim of this study is to obtain an optimal solution and study the effectiveness of the algorithm comparing it to the Simplex method in Microsoft Excel. This study uses two data, consisting of primary and secondary data. Based on the results of parameter testing, the proven parameters are nClan, nCi,α,β and MaxGen have a significant effect. The final simulation results have also shown a comparison of the EHO algorithm with the Simplex method having a very small percentage deviation. This shows that the EHO algorithm is effective for completing optimization multiple constraints knapsack 0-1. Keywords: EHO Algorithm, Multiple Constraints Knapsack 0-1 Problem.


Author(s):  
С. Л. Войтенко

Висвітлені основні підходи до комплексної оцінки кнурів і свиноматок за якістю потомства в умовах ферми (господарства). Запропоновано визначати цінність кнурів і свиноматок не лише за  відгодівельними і м’ясними ознаками їх потомків, але й за власною продуктивністю останніх.  Описано послідовність добору тварин для їх випробовування в умовах ферми за власною продуктивністю та відгодівельними і м’ясними ознаками з визначенням балу за кожну із ознак. Для комплексної оцінки кнурів і свиноматок за якістю потомства запропоновано використовувати розроблений оціночний індекс,  в основі якого середня величина усіх досліджуваних під час випробовування ознак у сибсів і напівсибсів. Запропонована нова методика оцінки кнурів і свиноматок за якістю потомства дасть змогу оцінити не лише племінних свиней, але помісних і гібридних,  застосовувати єдину методику оцінки тварин основного стада у господарствах різної категорії, обходитися без станцій контрольної відгодівлі свиней та визначити цінність кнура і свиноматки за якістю потомства на основі розробленого оціночного індексу. The main approaches to the integrated evaluation of boars and sows on the quality of offspring in the conditions of a farm (farm) are covered. It is offered to determine the value of boars and sows not only on the fattening and meat characteristics of their offspring, but also on their own productivity of the latter. The sequence of selection of animals for their testing in conditions of the farm according to their own productivity, fattening and meat characteristics with a score for each of the characteristics is described. For a comprehensive evaluation of boars and sows on the quality of offspring offered to use the developed evaluation index, which is based on the average value of all the tests for testing the characteristics of descendants. Offered new method for estimating boars and sows on the quality of offspring will make it possible to estimate not only breeding pigs but hybrid and local ones, to apply a uniform method for estimating the animals of the main herd in farms of different categories, to dispense with pigs' control stations and determine the value of boars and sows in the quality of offspring based on the developed evaluation index.


Methodology ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 177-188 ◽  
Author(s):  
Martin Schultze ◽  
Michael Eid

Abstract. In the construction of scales intended for the use in cross-cultural studies, the selection of items needs to be guided not only by traditional criteria of item quality, but has to take information about the measurement invariance of the scale into account. We present an approach to automated item selection which depicts the process as a combinatorial optimization problem and aims at finding a scale which fulfils predefined target criteria – such as measurement invariance across cultures. The search for an optimal solution is performed using an adaptation of the [Formula: see text] Ant System algorithm. The approach is illustrated using an application to item selection for a personality scale assuming measurement invariance across multiple countries.


2020 ◽  
Vol 5 (1) ◽  
pp. 456
Author(s):  
Tolulope Latunde ◽  
Joseph Oluwaseun Richard ◽  
Opeyemi Odunayo Esan ◽  
Damilola Deborah Dare

For twenty decades, there is a visible ever forward advancement in the technology of mobility, vehicles and transportation system in general. However, there is no "cure-all" remedy ideal enough to solve all life problems but mathematics has proven that if the problem can be determined, it is most likely solvable. New methods and applications will keep coming to making sure that life problems will be solved faster and easier. This study is to adopt a mathematical transportation problem in the Coca-Cola company aiming to help the logistics department manager of the Asejire and Ikeja plant to decide on how to distribute demand by the customers and at the same time, minimize the cost of transportation. Here, different algorithms are used and compared to generate an optimal solution, namely; North West Corner Method (NWC), Least Cost Method (LCM) and Vogel’s Approximation Method (VAM). The transportation model type in this work is the Linear Programming as the problems are represented in tables and results are compared with the result obtained on Maple 18 software. The study shows various ways in which the initial basic feasible solutions to the problem can be obtained where the best method that saves the highest percentage of transportation cost with for this problem is the NWC. The NWC produces the optimal transportation cost which is 517,040 units.


Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1374
Author(s):  
Bartosz Rozegnał ◽  
Paweł Albrechtowicz ◽  
Dominik Mamcarz ◽  
Monika Rerak ◽  
Maciej Skaza

This paper presents the skin effect impact on the active power losses in the sheathless single-core cables/wires supplying nonlinear loads. There are significant conductor losses when the current has a distorted waveform (e.g., the current supplying diode rectifiers). The authors present a new method for active power loss calculation. The obtained results have been compared to the IEC-60287-1-1:2006 + A1:2014 standard method and the method based on the Bessel function. For all methods, the active power loss results were convergent for small-cable cross-section areas. The proposed method gives smaller power loss values for these cable sizes than the IEC and Bessel function methods. For cable cross-section areas greater than 185 mm2, the obtained results were better than those for the other methods. There were also analyses of extra power losses for distorted currents compared to an ideal 50 Hz sine wave for all methods. The new method is based on the current penetration depth factor calculated for every considered current harmonics, which allows us to calculate the precise equivalent resistance for any cable size. This research is part of our work on a cable thermal analysis method that has been developed.


Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 325 ◽  
Author(s):  
Shijun Chen ◽  
Huwei Chen ◽  
Shanhe Jiang

Electric vehicles (EVs) are designed to improve the efficiency of energy and prevent the environment from being polluted, when they are widely and reasonably used in the transport system. However, due to the feature of EV’s batteries, the charging problem plays an important role in the application of EVs. Fortunately, with the help of advanced technologies, charging stations powered by smart grid operators (SGOs) can easily and conveniently solve the problems and supply charging service to EV users. In this paper, we consider that EVs will be charged by charging station operators (CSOs) in heterogeneous networks (Hetnet), through which they can exchange the information with each other. Considering the trading relationship among EV users, CSOs, and SGOs, we design their own utility functions in Hetnet, where the demand uncertainty is taken into account. In order to maximize the profits, we formulate this charging problem as a four-stage Stackelberg game, through which the optimal strategy is studied and analyzed. In the Stackelberg game model, we theoretically prove and discuss the existence and uniqueness of the Stackelberg equilibrium (SE). Using the proposed iterative algorithm, the optimal solution can be obtained in the optimization problem. The performance of the strategy is shown in the simulation results. It is shown that the simulation results confirm the efficiency of the model in Hetnet.


Author(s):  
Mark E. Benden ◽  
Kristen Miller ◽  
Eric Wilke ◽  
Eduardo Ibarra

In this article the authors illustrate how individual expert ratings can be employed to prioritize specifications for use in forced rankings. Those rankings are then used to select a design with the best overall usability. The authors provide an example of this approach in the selection of a medical transport vehicle seat to produce a more ergonomic product that could improve patient outcomes and driver safety.


2011 ◽  
Vol 383-390 ◽  
pp. 1500-1506
Author(s):  
Yu Min Pan ◽  
Xiao Yu Zhang ◽  
Peng Qian Xue

A new method of rolling prediction for gas emission based on wavelet neural network is proposed in this paper. In the method, part of the sample data is selected, which length is constant, and the data is reselected as the next prediction step. Then a wavelet neutral network is adopted to prediction which input data is rolling, the sequence model of rolling prediction is thus constructed. Simulation results have proved that the method is valid and feasible.


2006 ◽  
Vol 519-521 ◽  
pp. 949-954 ◽  
Author(s):  
Beong Bok Hwang ◽  
J.H. Shim ◽  
Jung Min Seo ◽  
H.S. Koo ◽  
J.H. Ok ◽  
...  

This paper is concerned with the analysis of the forming load characteristics of a forward-backward can extrusion in both combined and sequence operation. A commercially available finite element program, which is coded in the rigid-plastic finite element method, has been employed to investigate the forming load characteristics. AA 2024 aluminum alloy is selected as a model material. The analysis in the present study is extended to the selection of press frame capacity for producing efficiently final product at low cost. The possible extrusion processes to shape a forward-backward can component with different outer diameters are categorized to estimate quantitatively the force requirement for forming forward-backward can part, forming energy, and maximum pressure exerted on the die-material interfaces, respectively. The categorized processes are composed of combined and/or some basic extrusion processes such as sequence operation. Based on the simulation results about forming load characteristics, the frame capacity of a mechanical press of crank-drive type suitable for a selected process could be determined along with securing the load capacity and with considering productivity. In addition, it is suggested that different load capacities be selected for different dimensions of a part such as wall thickness in forward direction and etc. It is concluded quantitatively from the simulation results that the combined operation is superior to sequence operation in terms of relatively low forming load and thus it leads to low cost for forming equipments. However, it is also known from the simulation results that the precise control of dimensional accuracy is not so easy in combined operation. The results in this paper could be a good reference for analysis of forming process for complex parts and selection of proper frame capacity of a mechanical press to achieve low production cost and thus high productivity.


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