The progressive hedging algorithm of Rockafellar and Wets for multistage stochastic programming problems could be viewed as a two-block alternating direction method of multipliers. This correspondence brings in some u...
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The progressive hedging algorithm of Rockafellar and Wets for multistage stochastic programming problems could be viewed as a two-block alternating direction method of multipliers. This correspondence brings in some useful results. In particular, it provides a new proof for the convergence of the progressive hedging algorithm with a flexibility in the selection of primal and dual step lengths and it helps to develop a new progressive hedging algorithm for solving risk averse stochastic optimization problems with cross constraints.
The progressive hedging algorithm (PHA) is an effective solution method for solving monotone stochastic variational inequalities (SVIs). However, this validity is based on the assumption of global maximal monotonicity...
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The progressive hedging algorithm (PHA) is an effective solution method for solving monotone stochastic variational inequalities (SVIs). However, this validity is based on the assumption of global maximal monotonicity. In this paper, we propose a localized PHA for solving nonmonotone SVIs and show that its validity is based on the weaker assumption of locally elicitable maximal monotonicity. Furthermore, we prove that such assumption holds when the mapping involved in the SVI is locally elicitable monotone or locally monotone. The local convergence of the proposed algorithm is established, and it is shown that the localized PHA has the rate of linear convergence under some mild assumptions. Some numerical experiments, including a two-stage orange market problem and randomly generated two-stage piecewise stochastic linear complementarity problems, indicate that the proposed algorithm is efficient.
It is of practical importance to incorporate a risk-averse objective in an optimal control problem under uncertainty. By leveraging the dual relationship between risk and regret measures, the risk-averse optimal contr...
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It is of practical importance to incorporate a risk-averse objective in an optimal control problem under uncertainty. By leveraging the dual relationship between risk and regret measures, the risk-averse optimal control problem can be equivalently transformed into an optimal control problem with nonanticipativity constraints and expectation objective function. A modified progressive hedging algorithm is then proposed to solve the transformed problem, in which the descent conditions are enforced to ensure global convergence of the algorithm. Numerical results of three different types of problems are presented to show the applicability and effectiveness of the modified progressive hedging algorithm.
Recently, stochastic variational inequality (SVI) has been extended from single stage to multistage by Rockafellar and Wets (Math. Program., 165:331-360, 2017) and progressive hedging algorithm (PHA) has also been ext...
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Recently, stochastic variational inequality (SVI) has been extended from single stage to multistage by Rockafellar and Wets (Math. Program., 165:331-360, 2017) and progressive hedging algorithm (PHA) has also been extended from stochastic programming to multistage stochastic linear comple-mentarity and SVI by Rockafellar and Sun (Math. Program., 174:453-471, 2019). However, the per-iteration cost of PHA can be prohibitively high when the scenario set is large, despite the decomposition and parallelizable nature of the algorithm. To address this issue, we propose a randomized PHA that allows us to control the per-iteration cost by randomly selecting a small subset of scenarios and updating only the corresponding variable components while freezing the variables corresponding to the unselected scenarios at the current iteration. By measuring the quality of an approximate solution using a re-stricted merit function, we demonstrate that despite the significant reduction in per-iteration cost, the randomized PHA converges in expectation and in an ergodic sense at the same sublinear rate as the original PHA.
A key feature of the tank container (TC) operating industry is that customers overhold TCs to provide temporary storage equipment for their contents rather than provide their own storage facilities. TC operators charg...
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A key feature of the tank container (TC) operating industry is that customers overhold TCs to provide temporary storage equipment for their contents rather than provide their own storage facilities. TC operators charge a very profitable fee (demurrage charge) for this service making it an attractive business proposition, but it can be detrimental to holistic network flows and fleet sizing. This paper addresses the problem of jointly optimising TC demurrage policy and TC flow, in the face of uncertain TC maintenance times, to maximise profits. A progressive hedging algorithm with expanded time-space network (PHA-ETSN) is designed to tackle this tactical level optimisation problem as other established techniques struggle with this optimisation in terms of computational time and memory requirements. Experiments are performed to illustrate how the optimisation tool can be used to investigate how demurrage policy affects different operational costs and TC hire revenue and thereby profit. These experiments demonstrate how the optimisation tool can be used by managers not only to optimise demurrage policy but also to explore and to understand more deeply the costs and profits in their operations.& COPY;2022 Elsevier B.V. All rights reserved.
This short note discusses some structural properties of the progressive hedging algorithm. It is based on the finite case, but allows for event trees that are unbalanced and where the nodes can have a varying number o...
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The high proportion of renewable energy presents numerous new features in the power system, which poses new challenges for the planning and operation of the power system. The energy storage system is an important tech...
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ISBN:
(纸本)9798350349047;9798350349030
The high proportion of renewable energy presents numerous new features in the power system, which poses new challenges for the planning and operation of the power system. The energy storage system is an important technology and basic equipment to support the construction of the new power system under the dual carbon goals. Rational configuration of energy storage cluster can effectively improve the operation of the power system. To solve the issue that the current requirements on the energy storage cluster scale of power systems with substantial renewable energy output are too general to provide a suitable energy storage cluster configuration scheme, this paper proposes an energy storage cluster planning method to describe the uncertainty of renewable energy output and load. Considering the characteristics of the system, the proposed method is formulated as a stochastic programming model to plan the energy storage cluster. The progressive hedging algorithm is employed to solve the proposed model. Finally, the modified IEEE RTS79 test system is used to verify the method, and the best RER range is obtained.
In this paper we describe a real-world large-scale stochastic integer waste-management decision making problem. The problem consists of choosing the optimal locations and capacities of new incineration plants, that wi...
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In this paper we describe a real-world large-scale stochastic integer waste-management decision making problem. The problem consists of choosing the optimal locations and capacities of new incineration plants, that will be used for the disposal of waste. To solve this problem, we implement a modied version of the progressive hedging algorithm. The presented case study with real-world data concerns the situation in the Czech Republic.
progressive hedging algorithm (PHA) is a long-standing algorithm originally designed for stochastic programming problems and has recently been extended to solving multistage stochastic variational inequalities (SVIs),...
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progressive hedging algorithm (PHA) is a long-standing algorithm originally designed for stochastic programming problems and has recently been extended to solving multistage stochastic variational inequalities (SVIs), both are important tools for processing mathematical programming problems with uncertainty. In this note, we first show that PHA for two-stage stochastic linear complementarity problems, a special case of multistage SVIs, is an application of the DouglasRachford operator splitting algorithm and then extend this result to multistage SVIs. To do this, we first reformulate the focused problems as zero-finding problems of the sum of two maximal monotone operators. This reformulation plays a key role in establishing the connections Since Douglas-Rachford operator splitting algorithm can be viewed as a proximal point algorithm, our result sharpens the understanding of PHA.
This paper presents an effective progressive hedging algorithm for vehicle routing problem with two-layers time window assignment and stochastic service times (2L-TWAVRPSST). Based on a predefined exogenous time windo...
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This paper presents an effective progressive hedging algorithm for vehicle routing problem with two-layers time window assignment and stochastic service times (2L-TWAVRPSST). Based on a predefined exogenous time window determined by the customers, an endogenous time window is assigned to each customer. Endogenous time windows have flexible width and composed of two-layers. The outer layer is wider than inner layer and is determined by violation variable. This approach aims to giving more flexibility to career companies for serving more customers using less vehicles. Customers could be visited even after the end of their assigned time windows by paying proportional penalty, while extra violation from the outer layer is not permitted. This problem is formulated as a two-stage stochastic model with the first-stage decisions of assigning inner and outer layers time window. Then in the second stage, routes are planned for each scenario combination of stochastic demand and service time. The validity and effectiveness of the proposed model was examined by various numerical examples. The problem was solved by a progressivehedging (PH) algorithm for large-scale instances. The results confirm efficiency of the considered solution approach in different instances.
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