The paper carried out a methodology to design stationary energy storage system (ESS) employing a deterministic algorithm. The primary scope is to maximizing economic benefits arriving to define an optimal siting and s...
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ISBN:
(纸本)9798350387032;9798350387025
The paper carried out a methodology to design stationary energy storage system (ESS) employing a deterministic algorithm. The primary scope is to maximizing economic benefits arriving to define an optimal siting and sizing of the ESS utilizing deterministic algorithm. The objective function of the algorithm is set on the net present value (NPV) calculation. Numerical simulation of a d.c. railway line with new high-speed trains has been presented to assess power flow between trains, leading to the identification of suitable locations and sizes for electrical substations and storage systems within the railway network. The main scope of the proposed approach lies in using an optimization algorithm to maximize the economic advantage of installing an energy storage system in a railway line also minimizing the energy purchase from the grid with low computational effort, versatility and easy implementation features. The methodology proposed has been applied to a case study.
We study the problem of maximizing a monotone submodular function subject to a matroid constraint, and present for it a deterministic non-oblivious local search algorithm that has an approximation guarantee of 1 - 1/e...
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ISBN:
(纸本)9798331516758;9798331516741
We study the problem of maximizing a monotone submodular function subject to a matroid constraint, and present for it a deterministic non-oblivious local search algorithm that has an approximation guarantee of 1 - 1/e - epsilon (for any epsilon > 0) and query complexity of (O) over tilde (epsilon)(nr), where n is the size of the ground set and r is the rank of the matroid. Our algorithm vastly improves over the previous state-of-the-art 0.5008-approximation deterministic algorithm, and in fact, shows that there is no separation between the approximation guarantees that can be obtained by deterministic and randomized algorithms for the problem considered. The query complexity of our algorithm can be improved to (O) over tilde (epsilon)(n + r root n) using randomization, which is nearly-linear for r = O(root n), and is always at least as good as the previous state-of-the-art algorithms.
Cloud storage suffers from security. It is more prone to security breaches due to multitenant architecture and data remanence. Cloud storage is robust as well as promising platform from economic point of view as no ex...
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An enumeration-based deterministic algorithm is proposed for solving optimization problem. Discretization of the feasible region for each decision variable is applied to establish search tree so that all the solutions...
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This paper presents a new deterministic method and a polynomial-time algorithm for solving general huge-sized sensor network localization problems. The problem is first formulated as a nonconvex minimization, which wa...
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This paper presents a new deterministic method and a polynomial-time algorithm for solving general huge-sized sensor network localization problems. The problem is first formulated as a nonconvex minimization, which was considered as an NP-hard based on conventional theories. However, by the canonical duality theory, this challenging problem can be equivalently converted into a convex dual problem. By introducing a new optimality measure, a powerful canonical primal-dual interior (CPDI) point algorithm is developed which can solve efficiently huge-sized problems with hundreds of thousands of sensors. The new method is compared with the popular methods in the literature. Results show that the CPDI algorithm is not only faster than the benchmarks but also much more accurate on networks affected by noise on the distances.
Submodular optimization not only covers some classical combinatorial optimization problems, but also has a wide range of applications in fields such as machine learning and artificial intelligence. For submodular maxi...
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Submodular optimization not only covers some classical combinatorial optimization problems, but also has a wide range of applications in fields such as machine learning and artificial intelligence. For submodular maximization problems with constraints, some work has been done including the design of approximation algorithms, the measurement of approximation algorithms in terms of quality and efficiency, etc. In this paper, we consider the problem of maximizing a non-negative monotone submodular function minus a non-negative modular function with the cardinality constraint. This model has been applied to many scenarios, such as team formation problem, influence maximization problem, recommender systems problem, etc. We propose a threshold algorithm that achieve a (1/2 -..(..), 2)- bicriteria approximation ratio and query complexity..(.. log..). Our algorithm makes a small sacrifice in the approximation ratio but improves the best query complexity result of existing deterministic algorithms from..(..2) to..(.. log..) in the worst case.
SpartaPlex is a novel black-box optimization algorithm that yields superior results to state-of-the-art optimizers under tight function evaluation budgets. SpartaPlex is compared with 11 state-of-the-art optimization ...
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SpartaPlex is a novel black-box optimization algorithm that yields superior results to state-of-the-art optimizers under tight function evaluation budgets. SpartaPlex is compared with 11 state-of-the-art optimization algorithms on 24 n-dimensional and 6 application-based benchmark problems including mechanical, structural, and antenna design optimization. Using identical computing resources, SpartaPlex finds superior objective function solutions and, as dimensionality increases, executes at least an order of magnitude faster than prior state-of-the-art. SpartaPlex is additionally evaluated for scalability using a compute cluster with 46,080 cores across 16 Graphical Processing Units. Tested in up to 100,000 dimensions, SpartaPlex demonstrates linear scalability in time with respect to dimensionality and computational resources.
In this paper, we study the generalized submodular maximization problem with a nonnegative monotone submodular set function as the objective function and subject to a matroid constraint. The problem is generalized thr...
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In this paper, we study the generalized submodular maximization problem with a nonnegative monotone submodular set function as the objective function and subject to a matroid constraint. The problem is generalized through the curvature parameter alpha is an element of [0, 1] which measures how far a set function deviates from linearity to submodularity. We propose a deterministic approximation algorithm which uses the approximation algorithm proposed by Buchbinder et al. [2] as a building block and inherits the approximation guarantee for alpha = 1. For general value of the curvature parameter alpha is an element of [0, 1], we present an approximation algorithm with a factor of 1+h(alpha)(y)+Delta.[3+alpha-(2+alpha)y-(1+alpha)h(alpha)(y)]/2+alpha+(1+alpha)(1-y), where y is an element of [0, 1] is a predefined parameter for tuning the ratio. In particular, when alpha = 1 we obtain a ratio 0.5008 when setting y = 0.9, coinciding with the renowned state-of-art approximate ratio; when alpha = 0 that the object is a linear function, the approximation factor equals one and our algorithm is indeed an exact algorithm that always produces optimum solutions. (C) 2021 Elsevier B.V. All rights reserved.
In this paper we study the task of approach of two mobile agents having the same limited range of vision and moving asynchronously in the plane. This task consists in getting them in finite time within each other'...
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In this paper we study the task of approach of two mobile agents having the same limited range of vision and moving asynchronously in the plane. This task consists in getting them in finite time within each other's range of vision. The agents execute the same deterministic algorithm and are assumed to have a compass showing the cardinal directions as well as a unit measure. On the other hand, they do not share any global coordinates system (like GPS), cannot communicate and have distinct labels. Each agent knows its label but does not know the label of the other agent or the initial position of the other agent relative to its own. The route of an agent is a sequence of segments that are subsequently traversed in order to achieve approach. For each agent, the computation of its route depends only on its algorithm and its label. An adversary chooses the initial positions of both agents in the plane and controls the way each of them moves along every segment of the routes, in particular by arbitrarily varying the speeds of the agents. Roughly speaking, the goal of the adversary is to prevent the agents from solving the task, or at least to ensure that the agents have covered as much distance as possible before seeing each other. A deterministic approach algorithm is a deterministic algorithm that always allows two agents with any distinct labels to solve the task of approach regardless of the choices and the behavior of the adversary. The cost of a complete execution of an approach algorithm is the length of both parts of route travelled by the agents until approach is completed. Let Delta and l be the initial distance separating the agents and the length of (the binary representation of) the shortest label, respectively. Assuming that Delta andlare unknown to both agents, does there exist a deterministic approach algorithm always working at a cost that is polynomial in Delta andl? Actually the problem of approach in the plane reduces to the network problem of rendezvo
Protection devices are designed to provide high sensitivity to transients produced by undesirable conditions like lightning stroke, avoiding their operation under all tolerable events like switching operations. The pr...
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Protection devices are designed to provide high sensitivity to transients produced by undesirable conditions like lightning stroke, avoiding their operation under all tolerable events like switching operations. The problem of incorrect operation due to transient phenomena can be handled by two means, one is to allow the transients and provide additional logics in the relay, other means is to damp the oscillation from source side. Protection relays' not always must trip or send a trip signal and sometimes, only an alarm is necessary. In this context, this research presents a fast and reliable formulation for transmission lines (TLs) switching operations and lightning strokes detection and identification. The proposed methodology is based on Principal Component Analysis (PCA) and Euclidean Norm (EN);by using PCA it is possible to determine that normal operation signals describe a very well defined Ellipsoidal Pattern (EP). In this manner, by calculating the Euclidean Norm (EN) among Principal Components (PCs) for each sample and the origin of the reference Ellipsoidal Pattern, switching operations and lightning strokes are detected and identified. Test results show that the proposed algorithm presents high success on phenomena detection and identification, presenting a high potential for online applications. (c) 2016 Elsevier Ltd. All rights reserved.
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