The penetration of distributed generation and electric vehicles requires advanced monitoring and control strategies to maintain the reliable operation of active distribution network (ADN). Phasor measurement unit (PMU...
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The penetration of distributed generation and electric vehicles requires advanced monitoring and control strategies to maintain the reliable operation of active distribution network (ADN). Phasor measurement unit (PMU), as an advanced measuring device, has been applied in the operation of transmission systems for decades. Recently, it is anticipated that PMUs can be adopted in the distribution network. In this paper, the optimal branch PMU (BPMU) placement is studied. First, an optimization model for the multi-stage BPMU placement is established considering the observability of ADN. Moreover, the weights of buses are designed to consider the influence of uncertain renewable energy generation and loads. Then, probabilistic load flow (PLF) is used to solve power flow with uncertainties, and weights of buses are obtained based on probability distributions of voltage magnitude. Finally, binary integer programming (BIP) is adopted to obtain the locations of BPMUs. The proposed method is tested on customized IEEE 33-bus and PG&E 69-bus distribution network, and the results are compared with those considering other methods.
The stability region of a solution is the polyhedral set of objective coefficients for which the solution is optimal. It provides valuable information for sensitivity analysis and re-optimization. An exact description...
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The stability region of a solution is the polyhedral set of objective coefficients for which the solution is optimal. It provides valuable information for sensitivity analysis and re-optimization. An exact description of it may require an exponential number of inequalities. We develop polyhedral inner and outer approximations of linear size. (C) 2009 Elsevier B.V. All rights reserved.
This paper tackles management zone delineation and crop planning problems in an integrated precision agriculture framework. The zoning problem defines relatively homogeneous management zones regarding their soil prope...
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This paper tackles management zone delineation and crop planning problems in an integrated precision agriculture framework. The zoning problem defines relatively homogeneous management zones regarding their soil properties, and for which specific rates of agricultural inputs are necessary. From a sustainable point of view, the crop planning problem considers cropping of species from different botanic families in adjacent zones at the same time. With this in mind, we propose a novel linear binaryinteger program for an integrated zoning and crop planning problem with adjacency constraints. In this model, we maximize the incomes of the crop plan subject to zoning constraints and adjacency constraints on crop families. The proposed model has a column-based formulation, and as such, we develop a decomposition-based heuristic which make use of the column generation method with column-dependent rows. The decomposition strategy involves a master problem that deals with ensuring homogeneity of the selected management zones within the field partition and ensuring that the crop plan meets adjacency policies. On the other hand, the pricing problem generates rectangular management zones whose incorporation improves the objective value of the master problem. The algorithm is implemented in JuMP, a modeling language for mathematical optimization embedded in Julia. Results from a set of instances show the relevance of the decomposition-based heuristic.
This research note focuses on a problem where the cluster sizes for two partitions of the same object set are assumed known;however, the actual assignments of objects to clusters are unknown for one or both partitions...
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This research note focuses on a problem where the cluster sizes for two partitions of the same object set are assumed known;however, the actual assignments of objects to clusters are unknown for one or both partitions. The objective is to find a contingency table that produces maximum possible agreement between the two partitions, subject to constraints that the row and column marginal frequencies for the table correspond exactly to the cluster sizes for the partitions. This problem was described by H. Messatfa (Journal of Classification, 1992, pp. 5-15), who provided a heuristic procedure based on the linear transportation problem. We present an exact solution procedure using binary integer programming. We demonstrate that our proposed method efficiently obtains optimal solutions for problems of practical size.
In this paper,we consider approximation algorithms for optimizing a generic multivariate polynomial function in discrete(typically binary)*** models have natural applications in graph theory,neural networks,error-corr...
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In this paper,we consider approximation algorithms for optimizing a generic multivariate polynomial function in discrete(typically binary)*** models have natural applications in graph theory,neural networks,error-correcting codes,among many *** particular,we focus on three types of optimization models:(1)maximizing a homogeneous polynomial function in binary variables;(2)maximizing a homogeneous polynomial function in binary variables,mixed with variables under spherical constraints;(3)maximizing an inhomogeneous polynomial function in binary *** propose polynomial-time randomized approximation algorithms for such polynomial optimizationmodels,and establish the approximation ratios(or relative approximation ratios whenever appropriate)for the proposed *** examples of applications for these models and algorithms are discussed as well.
Problem solving in design is one of the main studied topic of research, and especially methods for problem solving. Generally, two kinds of methods are differentiated, those dedicated to routine design, and those focu...
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Problem solving in design is one of the main studied topic of research, and especially methods for problem solving. Generally, two kinds of methods are differentiated, those dedicated to routine design, and those focused on inventive design. The authors aim at linking the two approaches and building a continuum between both. Thus they studied the link and direct extraction of contradictions out of experiments. To do so they built a generic model of contradictions, the generalized system of contradictions (GSC). This paper proposes an algorithm for identifying and extracting generalized physical contradictions (GPCs), a part of the GSC, from experiments. First, the authors' design methodology to build the continuum from optimization till invention is introduced. The notion of GSC is presented and the focus is made on the notion of GPC. This one is described through binary integer programming and an algorithm is proposed in order to identify and extract complete set of generalized technical contradictions from experiments concerning the inventive problem.
In this note we provide a counterexample which resolves conjectures about Hadamard matrices made in this journal. Beder [1998. Conjectures about Hadamard matrices. Journal of Statistical Planning and Inference 72, 7-1...
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In this note we provide a counterexample which resolves conjectures about Hadamard matrices made in this journal. Beder [1998. Conjectures about Hadamard matrices. Journal of Statistical Planning and Inference 72, 7-14] conjectured that if H is a maximal m x n row-Hadamard matrix then m is a multiple of 4: and that if it is a power of 2 then every row-Hadamard matrix can be extended to a Hadamard matrix. Using binary integer programming we obtain a maximal 13 x 32 row-Hadamard matrix, which disproves both conjectures. Additionally for n being a multiple of 4 tip to 64, we tabulate values of m for which we have found a maximal row-Hadamard matrix. Based on the tabulated results we conjecture that a m x n row-Hadamard matrix with m >= n - 7 can be extended to a Hadamard matrix. Published by Elsevier B.V
Vehicle tracking in wide area motion imagery (WAMI) relies on associating vehicle detections across multiple WAMI frames to form tracks corresponding to individual vehicles. The temporal window length, i.e., the numbe...
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Vehicle tracking in wide area motion imagery (WAMI) relies on associating vehicle detections across multiple WAMI frames to form tracks corresponding to individual vehicles. The temporal window length, i.e., the number M of sequential frames, over which associations are collectively estimated poses a tradeoff between accuracy and computational complexity. A larger M improves performance because the increased temporal context enables the use of motion models and allows occlusions and spurious detections to be handled better. The number of total hypotheses tracks, on the other hand, grows exponentially with increasing M, making larger values of M computationally challenging to tackle. In this paper, we introduce stochastic progressive association across multiple frames, an iterative approach that progressively grows M with each iteration to improve estimated tracks by exploiting the enlarged temporal context while keeping computation manageable through two novel approaches for pruning association hypotheses. First, guided by a road network, accurately co-registered to the WAMI frames, we disregard unlikely associations that do not agree with the road network. Second, as M is progressively enlarged at each iteration, the related increase in association hypotheses is limited by revisiting only the subset of association possibilities rendered open by stochastically determined dis-associations for the previous iteration. The stochastic dis-association at each iteration maintains each estimated association according to an estimated probability for confidence, obtained via a probabilistic model. Associations at each iteration are then estimated globally over the M frames by (approximately) solving a binary integer programming problem for selecting a set of compatible tracks. Vehicle tracking results obtained over test WAMI data sets indicate that our proposed approach provides significant performance improvements over the state-of-the-art alternatives.
Well-structured collaborative learning groups scripted based on Collaborative Learning Flow Patterns (CLFPs) often result in successful collaborative learning outcomes. Formulation of such learner groups based on inst...
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ISBN:
(纸本)9781538638705
Well-structured collaborative learning groups scripted based on Collaborative Learning Flow Patterns (CLFPs) often result in successful collaborative learning outcomes. Formulation of such learner groups based on instructor defined criteria promises potentially effective performance of participating students. However, forming student groups manually based on multiple criteria often fails due to its complexity and the time limitations of practitioners. Hence, an intelligent assistance which supports adaptive collaboration scripting based on instructor defined criteria, while adhering to CLFPs is presented. Constraint Optimization techniques have been used for learner group formation and preliminary tests revealed that the proposed approach could be utilized when formulating student groups while satisfying team formation criteria.
Deploying a limited number of Phasor Measurement Units (PMUs) into the system to get full buses observability considering disturbance like communication failure, line outages is quite a challenging task. This paper pr...
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ISBN:
(纸本)9781509021574
Deploying a limited number of Phasor Measurement Units (PMUs) into the system to get full buses observability considering disturbance like communication failure, line outages is quite a challenging task. This paper proposes a possible problem solving approach by optimizing PMU location for obtaining maximum buses observability even when considering the potential loss of PMUs. With the knowledge of optimal PMU placement for topological observability under normal operating condition, the proposed method requires the number of PMUs to be one greater than the minimal requirement. The implemented model further considers conventional measurements for economic solution. The proposed approach is applied in four IEEE test systems including 2383 western polish to testify its effectiveness. The optimized deployment scheme also verifies the ability of approach to maximize the observable buses by installed PMUs.
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