Papers by Keyword: Cost Optimization

Abstract: Automatic change over system is a technique that ensures uninterrupted power supply in a building. It can also be designed to optimize the cost of electricity usage. Two-mode automatic change over system is common. Given the rising cost of electricity in recent times especially in developing country like Nigeria, many individuals and cooperate organizations now have three independent sources of power: photo voltaic, grid and generator power supplies, in attempt to optimize the cost of electricity. There is therefore a need to have an automatic change over system that is both configurable and maintainable to meet user’s needs. This work designed, simulated and implemented a hardware reconfigurable three-mode automatic change-over system. The mathematical models of the considered independent sources were considered before developing a state matrix that can be used to reconfigure the input sources to match user’s priority when installing the change-over system. The state diagram of the system was developed before simulating the system using Simulink in MATLAB. Relay logic was used to implement the state matric while AC contactors and relays were used to implement the physical system. The system showed optimal performance after testing and exhibited a near zero response time. It is expected that availability of this system will be optimal given that the system components can be locally sourced in case of component failures.

Abstract: This study aims to propose a method to calculate optimum exchanged grinding wheel diameter to minimize grinding cost in grinding surface process for stainless steel. The interactions of the grinding cost and optimum exchanged grinding wheel diameter have been analyzed and presented in mathematical formulae. To obtain the minimal grinding cost, the optimal exchanged grinding wheel diameter has been determined by investigating six two-level grinding process parameters including initial grinding wheel diameter, total dressing depth, radial grinding wheel wear per dress, wheel life, machine tool hour and grinding wheel cost. Based on 2⁶ experiments conducted in computational program, the optimal exchanged grinding wheel diameter is presented as a function of these grinding parameters. This developed model has been verified and proven by experimental results. The proposed method of calculation of the optimum exchanged grinding wheel diameter can be applied in practice to reduce the grinding cost.

Abstract: Grinding cost is an essential factor in a grinding process. In external cylindrical grinding, there has been an absence of various input grinding process parameters which have significant effects on the grinding cost. This paper presents an optimization of the grinding cost to determine the optimum exchanged grinding wheel diameter based on the seven input grinding parameters consisting of the initial grinding wheel diameter, the grinding wheel width, the wheel life, the radial grinding wheel wear per dress, the total depth of dressing cut, the machine tool hourly rate, and the grinding wheel cost. Combined with the screening experiments, the influence of the grinding parameters on the optimum exchanged grinding wheel diameter for the external cylindrical grinding process was examined. In addition, the effect of the interactions between the input grinding parameters was also evaluated. Finally, the regression equation for computing the optimum exchanged grinding wheel diameter was introduced. Therefore, the proposed model can be further applied for the external grinding process effectively.

Abstract: This paper presents the analysis on load models for cost optimization for distributed generation planning. The Embedded Meta EP – Firefly Algorithm technique is performed in order to identify the optimal distributed generation sizing. The result obtained show that the proposed technique has an acceptable performance to simulate the data and voltage dependent load models have a significant effect on total losses of a distribution system consequently will affect the cost of the system.

Abstract: This paper introduces a study on cost optimization of external cylindrical grinding. The effects of many grinding process parameters such as the initial grinding wheel diameter, the wheel life, the total dressing depth as well as the effect of cost components including the machine cost, the labor including overhead cost, the grinding wheel cost and so forth were taken into account. A model for calculation the optimum exchanged grinding wheel diameter was proposed. With this optimum diameter, a new and effective way of using the grinding wheel was proposed and both the grinding cost and grinding time can be reduced considerably.

Abstract: A bidding system of peak regulation right based on multi-agent is proposed according to the property of the peak regulation right. Then, the biggest goals of social benefits of all power generation companies are developed based on bidding system. Simultaneously bidding strategy of peak regulation right of the biggest goals of social benefits of all power generation company agents and internal cost optimization strategy of electricity generation companies are respectively raised for the goals. Example analysis shows that the proposed Bidding system takes on better viability and effectiveness.

Abstract: In the seismic design, it is important to consider higher risks of damage under seismic design forces than under other general loads, such as live load, dead load, or wind load. Although the full strength of the structure can be developed to resist various types of earthquake forces with respect to increased safety factor, this design concept may be not appropriate when we consider the economic benefit since the design under the seismic force is normally 15 to 25 % more expensive than the design of elastic response. As a one of the seismic design approaches, plastic hinge mechanism has drawn an interest to ensure the economic design performance under the earthquake. In this paper, forecasted seismic motion was simulated using a Monte Carlo simulation to determine the seismic design load applied to the structure system. Then for each seismic load, the economical set of plastic hinge mechanisms was optimized using linear programming.

Abstract: A PSO-algorithm-based job scheduling method that takes production cost as optimization object is presented in this paper. The cost optimization model of HFSP, in which production cost is considered as an optimal factor, is constructed. PSO is used to take global optimization, make the production task assignment and find which machine the jobs should be assigned at each stage, which is also called the process route of the job. After that the local assignment rules are used to determine the job’s starting time and processing sequence at each stage. The total production cost converted by time-based scheduling results is comprehensively considering the processing cost, waiting costs, and the products storage costs. The numerical results show the effectiveness of the algorithm after comparing between multi-group programs.

Abstract: A differential evolution algorithm based job scheduling method is presented, whose optimization target is production cost. The cost optimization model of hybrid flow-shop is thereby constructed through considering production cost as a factor in scheduling problem of hybrid flow-shop. In the implementation process of the method, DE is used to take global optimization and find which machine the jobs should be assigned on at each stage, which is also called the process route of the job; then the local assignment rules are used to determine the job’s starting time and processing sequence at each stage. With converting time-based scheduling results to fitness function which is comprehensively considering the processing cost, waiting costs, and the products storage costs, the processing cost is taken as the optimization objective. The numerical results show the effectiveness of the algorithm after comparing between multi-group programs.

Abstract: This paper introduces a new study on cost optimization of steel shot blasting systems. In the study, the influences of blasting process parameters such as air pressure, nozzle diameter, cost components as well as the effect of the nozzle wear on the cleaning cost were investigated. For calculation of the optimum exchanged nozzle diameter (called optimum diameter) a regression model was proposed. By using this model, both cleaning cost and cleaning time can be reduced considerably.