{"title":"几何缩放的复杂性","authors":"Antoine Deza , Sebastian Pokutta , Lionel Pournin","doi":"10.1016/j.orl.2023.11.010","DOIUrl":null,"url":null,"abstract":"<div><p>Geometric scaling, introduced by Schulz and Weismantel in 2002, solves the integer optimization problem <span><math><mi>max</mi><mo></mo><mo>{</mo><mi>c</mi><mo>⋅</mo><mi>x</mi><mo>:</mo><mi>x</mi><mo>∈</mo><mi>P</mi><mo>∩</mo><msup><mrow><mi>Z</mi></mrow><mrow><mi>n</mi></mrow></msup><mo>}</mo></math></span> by means of primal augmentations, where <span><math><mi>P</mi><mo>⊂</mo><msup><mrow><mi>R</mi></mrow><mrow><mi>n</mi></mrow></msup></math></span><span> is a polytope. We restrict ourselves to the important case when </span><em>P</em> is a 0/1-polytope. Schulz and Weismantel showed that no more than <span><math><mi>O</mi><mo>(</mo><mi>n</mi><msub><mrow><mi>log</mi></mrow><mrow><mn>2</mn></mrow></msub><mo></mo><mi>n</mi><msub><mrow><mo>‖</mo><mi>c</mi><mo>‖</mo></mrow><mrow><mo>∞</mo></mrow></msub><mo>)</mo></math></span> calls to an augmentation oracle are required. This upper bound can be improved to <span><math><mi>O</mi><mo>(</mo><mi>n</mi><msub><mrow><mi>log</mi></mrow><mrow><mn>2</mn></mrow></msub><mo></mo><msub><mrow><mo>‖</mo><mi>c</mi><mo>‖</mo></mrow><mrow><mo>∞</mo></mrow></msub><mo>)</mo></math></span> using the early-stopping policy proposed in 2018 by Le Bodic, Pavelka, Pfetsch, and Pokutta. Considering both the maximum ratio augmentation variant of the method as well as its approximate version, we show that these upper bounds are essentially tight by maximizing over a <em>n</em>-dimensional simplex with vectors <em>c</em> such that <span><math><msub><mrow><mo>‖</mo><mi>c</mi><mo>‖</mo></mrow><mrow><mo>∞</mo></mrow></msub></math></span> is either <em>n</em> or <span><math><msup><mrow><mn>2</mn></mrow><mrow><mi>n</mi></mrow></msup></math></span>.</p></div>","PeriodicalId":54682,"journal":{"name":"Operations Research Letters","volume":null,"pages":null},"PeriodicalIF":0.8000,"publicationDate":"2023-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The complexity of geometric scaling\",\"authors\":\"Antoine Deza , Sebastian Pokutta , Lionel Pournin\",\"doi\":\"10.1016/j.orl.2023.11.010\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Geometric scaling, introduced by Schulz and Weismantel in 2002, solves the integer optimization problem <span><math><mi>max</mi><mo></mo><mo>{</mo><mi>c</mi><mo>⋅</mo><mi>x</mi><mo>:</mo><mi>x</mi><mo>∈</mo><mi>P</mi><mo>∩</mo><msup><mrow><mi>Z</mi></mrow><mrow><mi>n</mi></mrow></msup><mo>}</mo></math></span> by means of primal augmentations, where <span><math><mi>P</mi><mo>⊂</mo><msup><mrow><mi>R</mi></mrow><mrow><mi>n</mi></mrow></msup></math></span><span> is a polytope. We restrict ourselves to the important case when </span><em>P</em> is a 0/1-polytope. Schulz and Weismantel showed that no more than <span><math><mi>O</mi><mo>(</mo><mi>n</mi><msub><mrow><mi>log</mi></mrow><mrow><mn>2</mn></mrow></msub><mo></mo><mi>n</mi><msub><mrow><mo>‖</mo><mi>c</mi><mo>‖</mo></mrow><mrow><mo>∞</mo></mrow></msub><mo>)</mo></math></span> calls to an augmentation oracle are required. This upper bound can be improved to <span><math><mi>O</mi><mo>(</mo><mi>n</mi><msub><mrow><mi>log</mi></mrow><mrow><mn>2</mn></mrow></msub><mo></mo><msub><mrow><mo>‖</mo><mi>c</mi><mo>‖</mo></mrow><mrow><mo>∞</mo></mrow></msub><mo>)</mo></math></span> using the early-stopping policy proposed in 2018 by Le Bodic, Pavelka, Pfetsch, and Pokutta. Considering both the maximum ratio augmentation variant of the method as well as its approximate version, we show that these upper bounds are essentially tight by maximizing over a <em>n</em>-dimensional simplex with vectors <em>c</em> such that <span><math><msub><mrow><mo>‖</mo><mi>c</mi><mo>‖</mo></mrow><mrow><mo>∞</mo></mrow></msub></math></span> is either <em>n</em> or <span><math><msup><mrow><mn>2</mn></mrow><mrow><mi>n</mi></mrow></msup></math></span>.</p></div>\",\"PeriodicalId\":54682,\"journal\":{\"name\":\"Operations Research Letters\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.8000,\"publicationDate\":\"2023-12-02\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Operations Research Letters\",\"FirstCategoryId\":\"91\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0167637723001980\",\"RegionNum\":4,\"RegionCategory\":\"管理学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"OPERATIONS RESEARCH & MANAGEMENT SCIENCE\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Operations Research Letters","FirstCategoryId":"91","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0167637723001980","RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"OPERATIONS RESEARCH & MANAGEMENT SCIENCE","Score":null,"Total":0}
Geometric scaling, introduced by Schulz and Weismantel in 2002, solves the integer optimization problem by means of primal augmentations, where is a polytope. We restrict ourselves to the important case when P is a 0/1-polytope. Schulz and Weismantel showed that no more than calls to an augmentation oracle are required. This upper bound can be improved to using the early-stopping policy proposed in 2018 by Le Bodic, Pavelka, Pfetsch, and Pokutta. Considering both the maximum ratio augmentation variant of the method as well as its approximate version, we show that these upper bounds are essentially tight by maximizing over a n-dimensional simplex with vectors c such that is either n or .
期刊介绍:
Operations Research Letters is committed to the rapid review and fast publication of short articles on all aspects of operations research and analytics. Apart from a limitation to eight journal pages, quality, originality, relevance and clarity are the only criteria for selecting the papers to be published. ORL covers the broad field of optimization, stochastic models and game theory. Specific areas of interest include networks, routing, location, queueing, scheduling, inventory, reliability, and financial engineering. We wish to explore interfaces with other fields such as life sciences and health care, artificial intelligence and machine learning, energy distribution, and computational social sciences and humanities. Our traditional strength is in methodology, including theory, modelling, algorithms and computational studies. We also welcome novel applications and concise literature reviews.