arXiv subjects

Zhila Dehdari Ebrahimi

Publications and source records attributed to Zhila Dehdari Ebrahimi.

6 recordsLinked to original sources

arXiv2021

A Two-Stage Stochastic Programming Model for Blood Supply Chain Management, Considering Facility Disruption and Service Level

In this paper, a blood supply chain network, where the occurrence of disruption might interrupt the flow of Red Blood Cells, is dealt with. In principle, the probability of disruption is not the only property confiding the network, but unprecedented fluctuations in supplies and demands also contribute to the network shortages and outdated blood units. Although the consideration of parameter uncertainties is of paramount importance in the real-world circumstances for a decision-maker, she or he would be willing to monitor the network in a properly broader perspective. Therefore, one of the eminent key performance indicators known as service level turned our attention. To tackle uncertainties in the mentioned network - comprising of the four conventional levels containing donors, blood collection facilities, blood banks, and hospitals - we present a two-stage stochastic programming model. Consequently, a toy-example is randomly generated to validate the proposed model. Furthermore, numerical analysis led us to a comprehensive service level analysis. Finally, potential pathways for future research are suggested.

eess.SY↗

arXiv2021

A Proposed Lean Distribution System for Solar Power Plants Using Mathematical Modeling and Simulation Technique

Today, power waste is one of the most crucial problems which power stations across the world are facing. One of the recent trends of the energy system is the lean management technique. When lean management is indicated by the system, customer value is increased and the waste process in industry or in a power station is reduced. In this paper, first of all, we propose mathematical modeling to reduce the cost of production, and then the simulation technique applies to electricity transmission distribution systems. Furthermore, we consider two criteria for comparison including the different costs of the system and the rate of energy waste during the transmission. The primary approach is to use both of the models in order to draw a comparison between simulation results and mathematical models. Finally, the analysis of the test results done by the CPLEX toolbox of MATLAB Software 2019 leads to a remarkable decrease in the costs of energy demand in the electricity transmitting network distribution system.

math.OC↗

arXiv2020

Analysis of Electricity Production Networks Using Mathematical and Simulation Method in Photovoltaic Power Generations

Currently waste of energy is one of the most important issues, power plants are encountered all over the world. In this study, two mathematical programming models are presented to formulate solar power plants pertinent to the design of a lean manufacturing system. We propose an approach consisting of a combination of mathematical and economic models used for distribution systems of electricity transmission networks. Besides the system, diverse costs and the rate of energy waste during the transmission are considered as two criteria for the comparison. The main approach is to employ a simulation method for both models and draw a comparison between the results of simulation and optimization models run by Lingo software. Finally, analyzing the test results lead the system to a remarkable cost reduction of the country energy demand in the distribution system of electricity transmission networks.

eess.SP↗

arXiv2020

A New Approach for Macroscopic Analysis to Improve the Technical and Economic Impacts of Urban Interchanges on Traffic Networks

Pursuing three important elements including economic, safety, and traffic are the overall objective of decision evaluation across all transport projects. In this study, we investigate the feasibility of the development of city interchanges and road connections for network users. To achieve this goal, a series of minor goals are required to be met in advance including determining benefits, costs of implement-ing new highway interchanges, quantifying the effective parameters, the increase in fuel consumption, the reduction in travel time, and finally influence on travel speed. In this study, geometric advancement of Hakim highway, and Yadegar-e-Emam Highway were investigated in the Macro view from the cloverleaf inter-section with a low capacity to a three-level directional intersection of the enhanced cloverleaf. For this purpose, the simulation was done by EMME software of INRO Company. The results of the method were evaluated by the objective of net present value (NPV), and the benefit and cost of each one was stated precisely in different years. At the end, some suggestion has been provided.

econ.GN↗

arXiv2020

Optimizing the Total Production and Maintenance Cost of an Integrated Multi-Product Process and Maintenance Planning (IPPMP) Model

Today, a competitive manufacturing environment imposes further production cost reduction on modern companies. Seeking proper recommendations in production and maintenance planning are the two essential cornerstones of effective production organizations. In the current research, we have considered the problem of integrated multi-product process and maintenance planning on a capacitated machine that is susceptible to random breakdown. Maintenance processes comprise general perfect repair (non-cyclical) as preventive maintenance (PM) in the early stages and minimal repair as corrective maintenance for the occurrence of machine breakdown. Furthermore, a rational presumption is reflected in the problem statement in which the time and cost of PM are pertinent to the interval between the prior perfect repair and current PM. The purpose served by this paper is to minimize the cost of production accompanying PM, and the expected corrective repair, consequently, a mixed-integer linear programming (MILP) model has been constructed to pave the way. The model investigated under two circumstances of the machine age effect and its absence. The outcome depicted that the presence of the machine age effect led to an accurate and lessen total cost calculation.

eess.SP↗

arXiv2020

A Systematic and Analytical Review of the Socioeconomic and Environmental Impact of the Deployed High-Speed Rail (HSR) Systems on the World

The installation of high-speed rail in the world during the last two decades resulted in significant socioeconomic and environmental changes. The U.S. has the longest rail network in the world, but the focus is on carrying a wide variety of loads including coal, farm crops, industrial products, commercial goods, and miscellaneous mixed shipments. Freight and passenger services in the U.S. dates to 1970, with both carried out by private railway companies. Railways were the main means of transport between cities from the late 19th century through the middle of the 20th century. However, rapid growth in production and improvements in technologies changed those dynamics. The fierce competition for comfortability and pleasantness in passenger travel and the proliferation of aviation services in the U.S. channeled federal and state budgets towards motor vehicle infrastructure, which brought demand for railroads to a halt in the 1950s. Presently, the U.S. has no high-speed trains, aside from sections of Amtrak s Acela line in the Northeast Corridor that can reach 150 mph for only 34 miles of its 457-mile span. The average speed between New York and Boston is about 65 mph. On the other hand, China has the world s fastest and largest high-speed rail network, with more than 19,000 miles, of which the vast majority was built in the past decade. Japan s bullet trains can reach nearly 200 miles per hour and dates to the 1960s. That system moved more than 9 billion people without a single passenger casualty. In this systematic review, we studied the effect of High-Speed Rail (HSR) on the U.S. and other countries including France, Japan, Germany, Italy, and China in terms of energy consumption, land use, economic development, travel behavior, time use, human health, and quality of life.

econ.GN↗