This paper presents a mathematical model for the energy management (EM) problem of a microgrid (MG) by means of a mixedintegerlinearprogramming approach. In the EM problem, the objective is to determine a generatio...
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This paper presents a mathematical model for the energy management (EM) problem of a microgrid (MG) by means of a mixedintegerlinearprogramming approach. In the EM problem, the objective is to determine a generation and a controllable load demand policy that minimises, over a planning horizon, the operation cost subject to economical and technical constraints. We propose a detail modelling for microturbines (MTs) and fuel cells (FCs), where the constraints associated with such factors as the ramps, minimum up and downtime, and generation limits, represent various peculiarities that have not been adequately considered in literature. The proposed model also considers a detailed representation of critical, reschedulable and curtailable loads, which are important aspects in the MG concept. To analyse the proposed modelling, a MG is used along with a MT, a FC, a battery bank, wind and photovoltaic generators connected to the main grid. The results indicate that the model is adequate for the MG EM. (C) 2014 Elsevier B.V. All rights reserved.
This paper studies the problem of computing an input vector for a given pair of Artificial Neural Network (ANN) and output vector, which is a kind of inverse problem. This problem has potential applications in design ...
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ISBN:
(纸本)9781450361033
This paper studies the problem of computing an input vector for a given pair of Artificial Neural Network (ANN) and output vector, which is a kind of inverse problem. This problem has potential applications in design of new objects, especially in design of new chemical compounds. This paper focuses on ANNs in which activation functions are represented as continuous piece-wise linear functions, which can exactly represent ReLU functions and well approximate sigmoid functions. It is shown that this inverse problem can be formulated as a mixedintegerlinearprogramming Problem (MILP) with O(vertical bar V vertical bar + n(b) variables and constraints, where V is a set of neurons in a given ANN and nb denotes the total number of break points over all activation functions f(nu), nu is an element of V .
This paper studies the problem of computing an input vector for a given pair of Artificial Neural Network（ANN） and output vector,which is a kind of inverse *** problem has potential applications in design of new obj...
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This paper studies the problem of computing an input vector for a given pair of Artificial Neural Network（ANN） and output vector,which is a kind of inverse *** problem has potential applications in design of new objects,especially in design of new chemical *** paper focuses on ANNs in which activation functions are represented as continuous piece-wise linear functions,which can exactly represent ReLU functions and well approximate sigmoid *** is shown that this inverse problem can be formulated as a mixedintegerlinearprogramming Problem（MILP） with O（|V|+n） variables and constraints,where V is a set of neurons in a given ANN and n denotes the total number of break points over all activation functions f,v∈V.
This study investigates the potential of hydrogen as an energy carrier to store seasonal energy from wind power in a remote off-grid underground mine located in the Northwest Territories, Canada. The energy demands to...
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This study investigates the potential of hydrogen as an energy carrier to store seasonal energy from wind power in a remote off-grid underground mine located in the Northwest Territories, Canada. The energy demands to be satisfied by the Energy Supply System (ESS) were electricity, heating, and cooling. Diesel imports and local wind were the energy utilities available. An optimization model of the mine's ESS was formulated using mixedintegerlinearprogramming to search for cost-effective and sustainable energy supply solutions. The objective function to be minimized was the total cost of the ESS (investment plus operation costs). Several optimization scenarios were investigated in a sensitivity analysis, varying the time discretization (12 typical days v. 365 days), and the amount of conventional energy sources (i.e., diesel) available. The analysis could be extended to include other demands, such as mobile work demand and related conversion technologies, i.e.,hydrogen-fueled mobile equipment. For the case study considered, results demonstrated that it is technically feasible to meet the demands of a remote mine using a local renewable energy resource exclusively. However, the cost, size, and complexity of the ESS make such an option, in general, unattractive in comparison with a fossil fuel-based system. (C) 2020 Elsevier Ltd. All rights reserved.
In this paper, we study the problem of resource allocation for a multiuser orthogonal frequency-division multiple access (OFDMA) downlink with eavesdropping. The considered setup consists of a base station, several us...
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In this paper, we study the problem of resource allocation for a multiuser orthogonal frequency-division multiple access (OFDMA) downlink with eavesdropping. The considered setup consists of a base station, several users, and a single eavesdropper that intends to wiretap the transmitted message within each OFDMA subchannel. By taking into consideration the existence of the eavesdropper, the base station aims to assign subchannels and allocate the available power in order to optimize the max-min fairness criterion over the users' secrecy rate. The considered problem is a mixedinteger nonlinear program. For a fixed subchannel assignment, the optimal power allocation is obtained by developing an algorithm of polynomial computational complexity. In the general case, the problem is investigated from two different perspectives due to its combinatorial nature. In the first, the number of users is equal or higher than the number of subchannels, whereas in the second, the number of users is less than the number of subchannels. In the first case, we provide the optimal solution in polynomial time by transforming the original problem into an assignment one for which there are polynomial time algorithms. In the second case, the secrecy rate formula is linearly approximated and the problem is transformed to a mixedintegerlinear program, which is solved by a branch-and-bound algorithm. Moreover, optimality is discussed for two particular cases where the available power tends to infinity and zero, respectively. Based on the resulting insights, three heuristic schemes of polynomial complexity are proposed, offering a better balance between performance and complexity. Simulation results demonstrate that each one of these schemes achieves its highest performance at a different power regime of the system.
This research addresses a single machine batch loading and scheduling problem. Jobs in the same family are processed as a batch in the machine with a known family-specific processing time. Each job in a batch requires...
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This research addresses a single machine batch loading and scheduling problem. Jobs in the same family are processed as a batch in the machine with a known family-specific processing time. Each job in a batch requires a known volume or space, and the total batch volume cannot exceed the available volume/capacity of the machine. Batch processing times increase proportionately with the time since the most recent rate-modifying activity and the starting time of a batch. A rate-modifying activity can be executed which restores original batch processing times. In this research, a solution procedure is proposed that simultaneously determines the appropriate batching of jobs and the number of rate-modifying activities. Job batches and the rate-modifying activities are then sequenced to minimise the makespan. To develop a solution procedure, a mixedintegerlinearprogramming model is formulated and a tight lower bound is proposed. Three genetic algorithms (GAs), including batch loading and sequencing heuristics, are proposed. The performance of the three GAs is compared, and the best GA is compared to other meta-heuristic algorithms.
This paper addresses profit maximization in location routing problem (LRP) where backordering is allowed and serving all customers is not mandatory. The problem is motivated by the practical case of distribution compa...
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This paper addresses profit maximization in location routing problem (LRP) where backordering is allowed and serving all customers is not mandatory. The problem is motivated by the practical case of distribution companies using temporary multi-user warehouses to serve their customers. We propose a multi-period novel mixedintegerlinearprogramming (MILP) model for the problem where demand is price sensitive. The model seeks to find optimal locations of warehouses over the planning horizon, set of orders to serve, to backorder or to reject, and routing decisions giving optimal profit. The commercial solver (CPLEX) is used to solve the model on small instances. For medium and large instances, we propose a solution approach that incorporates the Relax and Fix (R&F), Fix and Optimize (F&O) procedures combined with local search heuristics. Computational experiments and economic analysis show the relevance of the proposed approach and the impact of parameters on generated profit.
The behavior of timed continuous Petri nets (TCPN) can be ruled by linear equations during certain time elapses (IB-states), but changes in the marking and conflict solving policies make nonlinear the complete computa...
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The behavior of timed continuous Petri nets (TCPN) can be ruled by linear equations during certain time elapses (IB-states), but changes in the marking and conflict solving policies make nonlinear the complete computation of the behavior. In this paper a global characterization of the switching behavior of TCPN through mixed linear integer programming (MLIP) is presented. The contribution is an analytical technique to compute the evolution graph of a TCPN, which allows deriving MLIP problems from TCPN models including cycles and structural conflicts;conflict resolution policies by priorities and sharing are considered. (C) 2015 Elsevier Ltd. All rights reserved.
There are wide applications of block-rate pricing schemes in many ***,there are no significant studies that apply this common tariff for smart home energy management *** this paper,a three-time-frame energy management...
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There are wide applications of block-rate pricing schemes in many ***,there are no significant studies that apply this common tariff for smart home energy management *** this paper,a three-time-frame energy management scheme has been proposed for photovoltaic(PV)-powered grid-connected smart homes based on the well-known mixed-integerlinearprogramming optimization *** paper provides three original and novel smart home energy management algorithms that depend on the most common residential tariff specifically in developing *** different management concepts have been studied for a typical Egyptian *** concepts of shifting load,vehicle-to-home and reducing air conditioning have been tested according to a commonly applied slab *** proposed scheme considers the home battery extending lifetime *** also preserves comfortable lifestyle limits for home users according to Arab housing climatic conditions and ***,the economic feasibility of integrated PV modules for the studied home has been verified according to the Egyptian *** proposed energy management scheme of PV-powered home reduces the electrical power bill significantly in a wide range from 61%to only 19%of the default case bill according to the applied management technique.
Nowadays, Supply Chain success and competitiveness heavily depend on the integration of its components and adaptability to deal with a changing environment. This article suggests the integration of design and manageme...
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Nowadays, Supply Chain success and competitiveness heavily depend on the integration of its components and adaptability to deal with a changing environment. This article suggests the integration of design and management of a Supply Chain from an outcome-driven perspective. We propose a two-phase decision-making support methodology: first suppliers are pre-screened by solving a multi criteria sorting problem, and then a design and management plan is generated by solving a mixedintegerlinearprogramming Model. Experimentally we showed that the proposed methodology can efficiently solve to optimality the most popular benchmark instances published in previous paper moreover our model also includes problem characteristics that have not been addressed together in previous published papers.
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