This paper discusses the evolution and implementation of smart dispatch tools to support the real-time operation of the PJM competitive wholesale electricity market. These innovations include the implementation of mul...
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ISBN:
(纸本)9781457710001
This paper discusses the evolution and implementation of smart dispatch tools to support the real-time operation of the PJM competitive wholesale electricity market. These innovations include the implementation of multi-stage real-time dispatch software, adaptive generation modeling, enhanced visualization tools and comprehensive evaluation and feedback mechanisms through the perfect dispatch concept. The paper discusses the operational situations and challenges that have driven the need for continued evolution of dispatch tools. The paper explores efficiency gains that the market experienced when these innovations were successfully incorporated into the market clearing and dispatch processes at PJM.
Modernization and sustainment of legacy aircraft requires technology insertion which accounts for the complex interaction of the physical system interfaces and the strategic benefit of the new technology. This paper e...
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ISBN:
(纸本)9781467376778
Modernization and sustainment of legacy aircraft requires technology insertion which accounts for the complex interaction of the physical system interfaces and the strategic benefit of the new technology. This paper explores an objective method to evaluate new avionics architectures and to select the architecture implementation that achieves an optimal benefit to a fleet operator.
Second generation biofuels from wood gasification are thought to become competitive in the face of effective climate and energy security policies. Cost competitiveness crucially depends on the optimization of the enti...
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Second generation biofuels from wood gasification are thought to become competitive in the face of effective climate and energy security policies. Cost competitiveness crucially depends on the optimization of the entire supply chain-field-wheel involving optimal location, scaling and logistics. In this study, a linear mixed integer programming model has been developed to determine the optimal geographic locations and sizes of methanol plants and gas stations in Austria. Optimal locations and sizes are found by the minimization of costs with respect to biomass and methanol production and transport, investments for the production plants and the gas stations. Hence, the model covers competition in all levels of a biofuel production chain including supply of biomass, biofuel and heat, and demand for bio- and fossil fuels. The results show that Austria could be self-sufficient in the production of methanol for biofuels like M5, M10 or M20, using up to 8% of the arable land share. The plants are optimally located close to the potential supply of biomass (i.e. poplar) in Eastern Austria, and produce methanol around 0.4 is an element of(-1). Moreover, heat production could lower the methanol cost by 12%. Copyright (C) 2008 John Wiley & Sons, Ltd.
The scheduling for molten iron logistic optimization is to determine the distribution of molten iron from iron-making stage to steelmaking stage,the transportation routes of torpedo cars and locomotives such that the ...
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ISBN:
(纸本)9781510805750
The scheduling for molten iron logistic optimization is to determine the distribution of molten iron from iron-making stage to steelmaking stage,the transportation routes of torpedo cars and locomotives such that the molten iron from blast furnaces can be delivered to the steelmaking shops on schedule and on *** taking the molten iron transportation process of an iron and steel enterprise as research background,the paper investigated the torpedo car scheduling problem,which is a key problem in the molten iron logistics optimization and developed a mixed integer programming *** model was then solved by commercial optimization software CPLEX to obtain the torpedo car scheduling ***,another scheduling scheme was obtained by a heuristics based on the nearest neighborhood idea in which the earliest available torpedo car is used to service the un-serviced task whose tapping time is the *** schemes were compared to validate the efficacy and reasonability of the model.
Detailed scheduling of a packing hall consisting of a number of packing lines is a problem encountered in many process industries. The scheduling problem is complicated by the presence of sequence dependent changeover...
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Detailed scheduling of a packing hall consisting of a number of packing lines is a problem encountered in many process industries. The scheduling problem is complicated by the presence of sequence dependent changeovers of different lengths. Vehicle routing problems (VRP) arise in many distribution, product inventory, and mobile repair industries. A common objective is to find a route for a vehicle, which satisfies a variety of constraints, and so as to minimise the total vehicle operating cost. In other applications, it may be important to minimise the total time. Little work has been done on the solution of the large-scale design/scheduling/sequencing problems using VRP type formulations. A model for this problem has been presented and its computational performance is compared with other classical disjunctive formulations. The approach presented here is based on a continuous-time formulation in that all events (packing and changeovers) are allowed to start and end at any time. The proposed approach has excellent integrality property, as it does not contain any 'big M'. type of constraints encountered in these problems. This problem is formulated as a mixedinteger program and solved using a standard solver, which makes the proposed approach attractive commercially. The details of the formulation and the results of a large-scale commercial packing hall problem are given.
This work aims to develop an electronic system based on Light Emitting Diodes (LEDs) to emulate a reference light spectrum. Light Emitting Diodes are used due to their well-known advantages over other light sources. A...
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ISBN:
(纸本)9781509051281
This work aims to develop an electronic system based on Light Emitting Diodes (LEDs) to emulate a reference light spectrum. Light Emitting Diodes are used due to their well-known advantages over other light sources. As an example of application, this work focuses on the design and implementation of a solid-state solar simulator whose spectrum resembles the natural daylight to support research on photosynthetic organisms. The system design and a spectrum optimization process are presented. mixed integer programming (MIP) is adopted to set the optimal amount of LEDs that result in the most accurate response. The study of the LED spectrum, power converters for LED driving and control are discussed.
We investigate the Steiner tree problem with revenues, budget and hop constraints (STPRBH) on graph, which is a generalization of the well-known Steiner tree problem. Given a root node, edge costs, nodes revenues, as ...
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ISBN:
(纸本)9781467358125
We investigate the Steiner tree problem with revenues, budget and hop constraints (STPRBH) on graph, which is a generalization of the well-known Steiner tree problem. Given a root node, edge costs, nodes revenues, as well as a preset budget and hop, the STPRBH seeks to find a subtree that includes the root node and maximizes the sum of the total edge revenues respecting the budget and hop constraints. These constraints impose limits on the total cost of the network and the number of edges between any vertex and the root. Not surprisingly, the STPRBH is NP-hard. For this challenging network design problem that arises in telecommunication settings and multicast routing, we present several polynomial size formulations. We propose an enhanced formulation based on the classical work of Miller, Tucker, and Zemlin by using additional set of variables representing the rank-order of visiting the nodes. Also, we investigate a new formulation for the STPRBH by tailoring a partial rank-1 of the Reformulation-Linearization Technique. Extensive results are exhibited using a set of benchmark instances to compare the proposed formulations by using a general purpose MIP solver.
Data fusion is one of the research hotspots in the field of wireless sensor network. In allusion to the problem of excessive energy consumption of existing fusion methods, a data fusion scheme with minimized energy co...
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Data fusion is one of the research hotspots in the field of wireless sensor network. In allusion to the problem of excessive energy consumption of existing fusion methods, a data fusion scheme with minimized energy consumption is proposed in this article on the basis of the compressed sensing theory. Firstly, the influence of different fusion modes on data collection performance is analyzed;then, the influence of route and mixed CS fusion on energy optimization is considered in order to model the data fusion problem into the mixed integer programming problem with minimized energy consumption, and meanwhile a greedy algorithm based on fusion node increase is proposed to solve the above problem, wherein all nodes in the network are divided into fusion nodes used for CS encoding and forwarding nodes used for directly forwarding their own data and the received data;finally, a data fusion tree with minimized energy consumption is obtained. The result of the simulation experiment shows that the scheme proposed in this article is effective and superior to the traditional methods in the aspects of data recovery accuracy, network life cycle, etc.
The problem of distribution centers location with multiple practical constraints, such as soft service time window, rigid work time window, vehicle being reused and so on, is shown firstly. Secondly, a multi-factor in...
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The problem of distribution centers location with multiple practical constraints, such as soft service time window, rigid work time window, vehicle being reused and so on, is shown firstly. Secondly, a multi-factor integrated optimization model is given, which not only optimizes distribution centers location and vehicle routes, but also meets all the multiple practical constraints. A bi-level nested genetic algorithm is proposed thirdly, where the design of the lower algorithm meets various constraints of optimization. Finally, the feasibility of the model and the efficiency of the algorithm are tested by a numerical example.
Relief resource such as food, drinking water and other emergency living materials need to be updated regularly during a certain period of warranty. Therefore, this kind of emergency resource reserve needs to consider ...
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Relief resource such as food, drinking water and other emergency living materials need to be updated regularly during a certain period of warranty. Therefore, this kind of emergency resource reserve needs to consider both the daily management cost and the emergency supply guarantee. In order to study the joint of the physical reserve of emergency materials and agreement reserve, a hybrid integerprogramming model is established by selecting a supermarket around the shelter as a protocol supplier for a storage period of the shelter. In the case of limited investment in emergency management funds, the number of storage materials in the shelters and surrounding supermarkets is determined, and the Lingo software is used to solve the problem. Finally, the validity of the model is verified by an example.
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