{"title":"Asymptotic Scaling of Optimal Cost and Asymptotic Optimality of Base-Stock Policy in Several Multidimensional Inventory Systems","authors":"Jinzhi Bu, Xiting Gong, Xiuli Chao","doi":"10.1287/opre.2022.0488","DOIUrl":"https://doi.org/10.1287/opre.2022.0488","url":null,"abstract":"Operations Research, Ahead of Print. <br/>","PeriodicalId":54680,"journal":{"name":"Operations Research","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141737288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
On the Difficulty of Pricing Routes for Stochastic Vehicle Routing Problems Many approaches exist for dealing with the uncertainty in the vehicle routing problem with stochastic demands (VRPSD), but the most popular approach models the VRPSD as a two-stage stochastic program where a recourse policy prescribes actions that handle when the realized demands exceed the vehicle capacity. Similarly to other VRP variants, some state-of-the-art algorithms for the VRPSD use set-partitioning formulations that generate variables (routes) via a pricing problem. All of these algorithms, however, have strong assumptions on the probability distribution of customer demands, a simplification that might not be realistic in some applications. In “Hardness of Pricing Routes for Two-Stage Stochastic Vehicle Routing Problems with Scenarios,” Ota and Fukasawa examine the challenges associated with solving the pricing problem of the VRPSD when the customer demands are given by scenarios. They demonstrate that the VRPSD pricing problem is strongly NP-hard for a wide variety of recourse policies and route relaxations. This highlights the difficulty of developing efficient pricing algorithms for the VRPSD with scenario-based demand models.
{"title":"Hardness of Pricing Routes for Two-Stage Stochastic Vehicle Routing Problems with Scenarios","authors":"Matheus J. Ota, Ricardo Fukasawa","doi":"10.1287/opre.2023.0569","DOIUrl":"https://doi.org/10.1287/opre.2023.0569","url":null,"abstract":"On the Difficulty of Pricing Routes for Stochastic Vehicle Routing Problems Many approaches exist for dealing with the uncertainty in the vehicle routing problem with stochastic demands (VRPSD), but the most popular approach models the VRPSD as a two-stage stochastic program where a recourse policy prescribes actions that handle when the realized demands exceed the vehicle capacity. Similarly to other VRP variants, some state-of-the-art algorithms for the VRPSD use set-partitioning formulations that generate variables (routes) via a pricing problem. All of these algorithms, however, have strong assumptions on the probability distribution of customer demands, a simplification that might not be realistic in some applications. In “Hardness of Pricing Routes for Two-Stage Stochastic Vehicle Routing Problems with Scenarios,” Ota and Fukasawa examine the challenges associated with solving the pricing problem of the VRPSD when the customer demands are given by scenarios. They demonstrate that the VRPSD pricing problem is strongly NP-hard for a wide variety of recourse policies and route relaxations. This highlights the difficulty of developing efficient pricing algorithms for the VRPSD with scenario-based demand models.","PeriodicalId":54680,"journal":{"name":"Operations Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141642447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Near-Optimal Bayesian Online Assortment of Reusable Resources Motivated by rental services in e-commerce, we consider revenue maximization in the online assortment of reusable resources for different types of arriving consumers. We design competitive online algorithms compared with the optimal online policy in the Bayesian setting, where consumer types are drawn independently from known heterogeneous distributions over time. In scenarios with large initial inventories, our main result is a near-optimal competitive algorithm for reusable resources. Our algorithm relies on an expected linear programming (LP) benchmark, solves this LP, and simulates the solution through independent randomized rounding. The main challenge is achieving inventory feasibility efficiently using these simulation-based algorithms. To address this, we design discarding policies for each resource, balancing inventory feasibility and revenue loss. Discarding a unit of a resource impacts future consumption of other resources, so we introduce postprocessing assortment procedures to design and analyze our discarding policies. Additionally, we present an improved competitive algorithm for nonreusable resources and evaluate our algorithms using numerical simulations on synthetic data.
{"title":"Technical Note—Near-Optimal Bayesian Online Assortment of Reusable Resources","authors":"Yiding Feng, Rad Niazadeh, Amin Saberi","doi":"10.1287/opre.2020.0687","DOIUrl":"https://doi.org/10.1287/opre.2020.0687","url":null,"abstract":"Near-Optimal Bayesian Online Assortment of Reusable Resources Motivated by rental services in e-commerce, we consider revenue maximization in the online assortment of reusable resources for different types of arriving consumers. We design competitive online algorithms compared with the optimal online policy in the Bayesian setting, where consumer types are drawn independently from known heterogeneous distributions over time. In scenarios with large initial inventories, our main result is a near-optimal competitive algorithm for reusable resources. Our algorithm relies on an expected linear programming (LP) benchmark, solves this LP, and simulates the solution through independent randomized rounding. The main challenge is achieving inventory feasibility efficiently using these simulation-based algorithms. To address this, we design discarding policies for each resource, balancing inventory feasibility and revenue loss. Discarding a unit of a resource impacts future consumption of other resources, so we introduce postprocessing assortment procedures to design and analyze our discarding policies. Additionally, we present an improved competitive algorithm for nonreusable resources and evaluate our algorithms using numerical simulations on synthetic data.","PeriodicalId":54680,"journal":{"name":"Operations Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141646479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ironclad Method Boosts Blockchain Consistency and Speeds up Block Production Researchers have developed a novel method called Ironclad to address the scalability limitations of blockchains based on the Nakamoto consensus protocol. Although these blockchains have shown promise in various applications, the consensus properties of the protocol impose inherent scalability constraints. A key property, known as consistency, poses a challenge by presenting a trade-off between block production speed and the system’s security against adversarial attacks. To overcome this, the researchers propose the Ironclad method, which introduces a unique approach by assigning different weights to randomly selected blocks. By applying the Ironclad method to the original Nakamoto protocol and conducting rigorous analysis of its consensus properties, the researchers demonstrate a significant improvement in the consistency bound. This advancement allows for a much faster block production rate compared with the original protocol while maintaining the same level of security guarantees. The Ironclad method presents a promising solution to enhance blockchain scalability, overcoming the limitations of the Nakamoto consensus protocol. This breakthrough has the potential to unlock new possibilities for blockchain applications, paving the way for improved transaction speeds and increased efficiency in various industries.
{"title":"Improving Blockchain Consistency Bound by Assigning Weights to Random Blocks","authors":"Xueping Gong, Qing Zhang, Huizhong Li, Jiheng Zhang","doi":"10.1287/opre.2022.0463","DOIUrl":"https://doi.org/10.1287/opre.2022.0463","url":null,"abstract":"Ironclad Method Boosts Blockchain Consistency and Speeds up Block Production Researchers have developed a novel method called Ironclad to address the scalability limitations of blockchains based on the Nakamoto consensus protocol. Although these blockchains have shown promise in various applications, the consensus properties of the protocol impose inherent scalability constraints. A key property, known as consistency, poses a challenge by presenting a trade-off between block production speed and the system’s security against adversarial attacks. To overcome this, the researchers propose the Ironclad method, which introduces a unique approach by assigning different weights to randomly selected blocks. By applying the Ironclad method to the original Nakamoto protocol and conducting rigorous analysis of its consensus properties, the researchers demonstrate a significant improvement in the consistency bound. This advancement allows for a much faster block production rate compared with the original protocol while maintaining the same level of security guarantees. The Ironclad method presents a promising solution to enhance blockchain scalability, overcoming the limitations of the Nakamoto consensus protocol. This breakthrough has the potential to unlock new possibilities for blockchain applications, paving the way for improved transaction speeds and increased efficiency in various industries.","PeriodicalId":54680,"journal":{"name":"Operations Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141644740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Short and General Duality Proof for Wasserstein Distributionally Robust Optimization","authors":"Luhao Zhang, Jincheng Yang, Rui Gao","doi":"10.1287/opre.2023.0135","DOIUrl":"https://doi.org/10.1287/opre.2023.0135","url":null,"abstract":"Operations Research, Ahead of Print. <br/>","PeriodicalId":54680,"journal":{"name":"Operations Research","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141717368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Risk-Adaptive Local Decision Rules","authors":"Johannes O. Royset, Miguel A. Lejeune","doi":"10.1287/opre.2023.0564","DOIUrl":"https://doi.org/10.1287/opre.2023.0564","url":null,"abstract":"Operations Research, Ahead of Print. <br/>","PeriodicalId":54680,"journal":{"name":"Operations Research","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141717369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Business Model Choice for Heavy Equipment Manufacturers","authors":"Philippe Blaettchen, Niyazi Taneri, Sameer Hasija","doi":"10.1287/opre.2023.0656","DOIUrl":"https://doi.org/10.1287/opre.2023.0656","url":null,"abstract":"Operations Research, Ahead of Print. <br/>","PeriodicalId":54680,"journal":{"name":"Operations Research","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141611541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Audit and Remediation Strategies in the Presence of Evasion Capabilities","authors":"Shouqiang Wang, Francis de Véricourt, Peng Sun","doi":"10.1287/opre.2022.0289","DOIUrl":"https://doi.org/10.1287/opre.2022.0289","url":null,"abstract":"Operations Research, Ahead of Print. <br/>","PeriodicalId":54680,"journal":{"name":"Operations Research","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141587805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}