The block cipher LBC-3, which was proposed by Nyssanbayeva et al. in 2022, has a 64-bit block size, an 80-bit secret key size, and the number of rounds is 20. The designer investigated the avalanche effect of LBC-3, a...
详细信息
In this paper, we focus on the optimization of large-scale multi-agent systems, where agents collaboratively optimize the sum of local objective functions through their own continuous and/or discrete decision variable...
详细信息
Solving combinatorial optimization problems holds significant practical importance, and many such problems can be transformed into MILP problems. Currently, Branch-and-Bound (B&B) is a typical method for solving M...
详细信息
mixedintegerlinear programs (MILP) are flexible and powerful tools for modeling and solving many difficult real-world combinatorial optimization problems. In this paper, we propose a novel machine learning (ML)-base...
详细信息
mixedintegerlinear programs (MILP) are flexible and powerful tools for modeling and solving many difficult real-world combinatorial optimization problems. In this paper, we propose a novel machine learning (ML)-based framework ConPaS that learns to predict solutions to MILPs with contrastive learning. For training, we collect high-quality solutions as positive samples. We also collect low-quality or infeasible solutions as negative samples using novel optimization-based or sampling approaches. We then learn to make discriminative predictions by contrasting the positive and negative samples. During testing, we predict and fix the assignments for a subset of integer variables and then solve the resulting reduced MILP to find high-quality solutions. Empirically, ConPaS achieves state-of-the-art results compared to other ML-based approaches in terms of the quality of and the speed at which solutions are found. Copyright 2024 by the author(s)
The management of power systems depends on economic dispatch (EC) and constrained unit commitment (UC). A way to schedule generation to meet electricity demand (reliability), with a time-varying cycle (hourly, daily, ...
详细信息
To expedite the energy transformation of the power system, the involvement of thermal power units (TPUs) in deep peak regulation (DPR) has become an effective strategy for enhancing the utilization of renewable energy...
详细信息
LNG (Liquefied Natural Gas) provides a viable option to comply with emission control measures as an alternative marine fuel. Supply chain optimization is critical for LNG bunkering development in the mar-itime context...
详细信息
LNG (Liquefied Natural Gas) provides a viable option to comply with emission control measures as an alternative marine fuel. Supply chain optimization is critical for LNG bunkering development in the mar-itime context as it requires high capital-expenditure. This study proposes a model for optimizing the ship-to-ship LNG bunkering supply chain. The related problem is defined as a Multiple Period Maritime Fleet Size and Routing Problem. The proposed mathematical model has been solved for various demand scenarios obtained by multiple regression and forecasting as a case study of ship-to-ship LNG bunker deliveries in Turkey. The model presents an optimal solution as a tactical and strategic decision-making tool, finds the number and size of the LNG bunker barges and the optimum allocation of the barges and the distribution network within a ship-to-ship bunkering framework. Moreover, it provides a commercial framework for shipowners and suppliers by determining the breakeven point for investment decisions.(c) 2022 Elsevier Ltd. All rights reserved.
A challenge in planning the operations of multisite production networks is the need to simultaneously balance production across sites while satisfying customers demand and keeping customer service levels high and over...
详细信息
A challenge in planning the operations of multisite production networks is the need to simultaneously balance production across sites while satisfying customers demand and keeping customer service levels high and overall costs low. Accordingly, we present a planning approach for the simultaneous optimization of production and distribution operations. Specifically, we consider a regional Argon supply chain, comprised of multiple production sites and customers, in which liquid Argon is distributed through tanker trucks under cryogenic conditions. The proposed approach first generates detailed routes and then uses these routes in an integrated model to fully optimize production and distribution. Using a series of case studies, based on industrially inspired data, we show that the proposed approach leads to high quality results for regional networks of real-world sizes.(c) 2022 Elsevier Ltd. All rights reserved.
This paper develops a robust chance-constrained model for handling the uncertainties of generation and consumption in multi-carrier energy hubs. The proposed model incorporates corresponding loading factors for each t...
详细信息
This paper develops a robust chance-constrained model for handling the uncertainties of generation and consumption in multi-carrier energy hubs. The proposed model incorporates corresponding loading factors for each type of electrical, heating, and cooling loads. This is done to assess the maximum loadability of the whole system. In this respect, the chance-constrained approach is implemented for the feasibility assessment of the operation problem with uncertainties. The uncertainties which are assumed here include the forecast errors of electrical, heating, and cooling load demands, and the volatile solar power generation. The overall problem formulation is developed in the mixed-integer linear programming (MILP) framework. The standard chance-constrained approach is converted to a deterministic optimization model by utilizing the Big M method. The main objective of the proposed model is to maximize the loadability index with uncertainties while addressing the permissible risk index of the decision-maker. The studied energy hub comprises electrical, heating, and cooling loads, and the energy flow technique is adopted in this paper to model the load balance equations. The simulation results are presented for different scenarios while addressing features of the proposed model for the summer and winter seasons. Furthermore, the developed model is evaluated for different scenarios and a comparison is made with the information-gap decision theory (IGDT) method.
In a bike sharing system (BSS), for various reasons, such as truck fuel load, truck capacity and high customer demand, the number of trucks deployed by the BSS operator is usually insufficient and they cannot balance ...
详细信息
In a bike sharing system (BSS), for various reasons, such as truck fuel load, truck capacity and high customer demand, the number of trucks deployed by the BSS operator is usually insufficient and they cannot balance all of the stations in time. To incentivize users to relocate some of the excess bikes from stations with surplus bikes to bike deficient stations, a mixed rebalancing strategy is proposed. The problem is formulated as a mixed-integer linear programming model. A hybrid genetic algorithm is developed to solve the proposed problem. Computational experiments are performed to illustrate the properties of the problem. The numerical results show that the proposed solution method can yield high-quality solutions in short computing times.
暂无评论