{"title":"A dynamic model of investment in research and teaching facilities in academic institutions","authors":"Amir Brudner, Arieh Gavious","doi":"10.1007/s10479-024-06232-w","DOIUrl":"10.1007/s10479-024-06232-w","url":null,"abstract":"<div><p>Academic institutions seek to enhance their reputation, which is one of their primary assets. Doing so requires a massive investment of resources in research, recruiting a high-quality academic staff, and building campuses and state-of-the-art laboratories. To obtain the necessary financial resources, institutions must attract students, donors, and government budgets and grants. This paper introduces a stylized dynamic model demonstrating how an institution can best allocate its resources between teaching and research. We create a simulated competition that resembles the real situation where the enhancement of the institution’s reputation depends not only on its resource allocation but also on its competitors’ actions and reputation. We consider a two-institution contest over time using a differential game solution with open-loop strategies. In this case, the steady-state investment in research increases and the level of teaching decreases.</p></div>","PeriodicalId":8215,"journal":{"name":"Annals of Operations Research","volume":"343 1","pages":"67 - 85"},"PeriodicalIF":4.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789201","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":"An emergency supply policy for an inventory replenishment model with returns and partial backorders","authors":"Nethanel Drezner, Yonit Barron","doi":"10.1007/s10479-024-06261-5","DOIUrl":"10.1007/s10479-024-06261-5","url":null,"abstract":"<div><p>This paper studies a continuous-review inventory replenishment model with a limited storage capacity <i>S</i> in an uncertain environment. We assume that the demands and returns follow independent Poisson processes. We further assume a ra1079 shelf life, a random lead time, and early loss. The storage is managed according to the base-stock (<i>S</i>, <i>s</i>) policy for <span>(s<S,S>0.)</span> In case of overstock, each returned item exceeding <i>S</i> is transferred to a foreign facility. If during the lead time a demand reaches zero stock, we consider two alternatives: either allow partial backordering up to <span>(L_{B})</span> items, beyond which the unsatisfied demand is lost, or call for an immediate and costly emergency supply up to level <span>(0<Q_{B}^{e}le S)</span>. Our objective is to study how the thresholds <i>s</i>, <i>S</i>, <span>(L_{B},)</span> and <span>(Q_{B}^{e})</span> are impacted by the system’s parameters, such as returns, demands, and costs. Using a Markovian framework, we derive the steady-state probabilities for the inventory level, and construct closed-form expressions for the average cost functions. Then, we numerically investigate the impact of the different parameters on the best policy and on the threshold levels. We compare the two alternatives and identify situations in which calling for an emergency supply is economically profitable.</p></div>","PeriodicalId":8215,"journal":{"name":"Annals of Operations Research","volume":"343 1","pages":"175 - 221"},"PeriodicalIF":4.4,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10479-024-06261-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vincent T’kindt, Federico Della Croce, Mathieu Liedloff
{"title":"Moderate exponential-time algorithms for scheduling problems","authors":"Vincent T’kindt, Federico Della Croce, Mathieu Liedloff","doi":"10.1007/s10479-024-06289-7","DOIUrl":"10.1007/s10479-024-06289-7","url":null,"abstract":"<div><p>This survey investigates the field of moderate exponential-time algorithms for <span>({mathcal{N}mathcal{P}})</span>-hard scheduling problems, i.e., exact algorithms whose worst-case time complexity is moderately exponential with respect to brute force algorithms. Scheduling problems are very challenging problems for which interesting results have emerged in the literature since 2010. We will provide a comprehensive overview of the known results of these problems before detailing three general techniques to derive moderate exponential-time algorithms. These techniques are <i>Sort & Search</i>, <i>Inclusion–Exclusion</i> and <i>Branching</i>. In the last part of this survey, we will focus on side topics such as approximation in moderate exponential time, the design of lower bounds on worst-case time complexities or fixed-parameter tractability. We will also discuss the potential benefits of moderate exponential-time algorithms for efficiently solving in practice scheduling problems.</p></div>","PeriodicalId":8215,"journal":{"name":"Annals of Operations Research","volume":"343 2021-2023)","pages":"753 - 783"},"PeriodicalIF":4.4,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142826400","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":"Strategic investment in power generation and transmission under a feed-in premium scheme: a game theoretic real options analysis","authors":"Kazuya Ito, Makoto Tanaka, Ryuta Takashima","doi":"10.1007/s10479-024-06274-0","DOIUrl":"10.1007/s10479-024-06274-0","url":null,"abstract":"<div><p>The spread of renewable energy has been accelerated by investment in power generation and transmission systems under environmental policy support such as a feed-in premium (FIP) scheme. This study examines the decision-making of the transmission system operator (TSO) and the power generation company (GENCO), where the TSO maximizes social surplus by investing in transmission lines, and the GENCO maximizes its profit by investing in power generation facilities. Specifically, the TSO decides the investment timing, while the GENCO decides the capacity. We develop a real options model to analyze the equilibrium investment timing and capacity under uncertainties in a framework of game between TSO and GENCO. We consider several scenarios in which the GENCO invests in non-renewable energy (NRE); invests in renewable energy (RE) with FIP; and invests in RE with its installation cost reduction. Our results indicate that FIP and the installation cost reduction of RE affect the equilibrium decision in a different manner. We find that FIP tends to be more welfare-enhancing than the reduction of RE installation cost when the degree of uncertainty is larger. We also demonstrate that social surplus can be increased without FIP if the installation cost of RE is reduced sufficiently in the future.</p></div>","PeriodicalId":8215,"journal":{"name":"Annals of Operations Research","volume":"343 1","pages":"349 - 372"},"PeriodicalIF":4.4,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10479-024-06274-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dynamic asset allocation with asset-specific regime forecasts","authors":"Yizhan Shu, Chenyu Yu, John M. Mulvey","doi":"10.1007/s10479-024-06266-0","DOIUrl":"10.1007/s10479-024-06266-0","url":null,"abstract":"<div><p>This article introduces a novel hybrid regime identification-forecasting framework designed to enhance multi-asset portfolio construction by integrating asset-specific regime forecasts. Unlike traditional approaches that focus on broad economic regimes affecting the entire asset universe, our framework leverages both unsupervised and supervised learning to generate tailored regime forecasts for individual assets. Initially, we use the <i>statistical jump model</i>, a robust unsupervised regime identification model, to derive regime labels for historical periods, classifying them into bullish or bearish states based on features extracted from an asset return series. Following this, a supervised gradient-boosted decision tree classifier is trained to predict these regimes using a combination of asset-specific return features and cross-asset macro-features. We apply this framework individually to each asset in our universe. Subsequently, return and risk forecasts which incorporate these regime predictions are input into Markowitz mean-variance optimization to determine optimal asset allocation weights. We demonstrate the efficacy of our approach through an empirical study on a multi-asset portfolio comprising twelve risky assets, including global equity, bond, real estate, and commodity indexes spanning from 1991 to 2023. The results consistently show outperformance across various portfolio models, including minimum-variance, mean-variance, and naive-diversified portfolios, highlighting the advantages of integrating asset-specific regime forecasts into dynamic asset allocation.</p></div>","PeriodicalId":8215,"journal":{"name":"Annals of Operations Research","volume":"346 1","pages":"285 - 318"},"PeriodicalIF":4.4,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143638474","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}
Nesrine Ouanes, Tatiana González Grandón, Holger Heitsch, René Henrion
{"title":"Optimizing the economic dispatch of weakly-connected mini-grids under uncertainty using joint chance constraints","authors":"Nesrine Ouanes, Tatiana González Grandón, Holger Heitsch, René Henrion","doi":"10.1007/s10479-024-06287-9","DOIUrl":"10.1007/s10479-024-06287-9","url":null,"abstract":"<div><p>In this paper, we deal with a renewable-powered mini-grid, connected to an unreliable main grid, in a Joint Chance Constrained (JCC) programming setting. In several rural areas in Africa with low energy access rates, grid-connected mini-grid system operators contend with four different types of uncertainties: forecasting errors of solar power and load; frequency and outages duration from the main-grid. These uncertainties pose new challenges to the classical power system’s operation tasks. Three alternatives to the JCC problem are presented. In particular, we present an Individual Chance Constraint (ICC), Expected-Value Model (EVM) and a so called regular model that ignores outages and forecasting uncertainties. The JCC model has the capability to guarantee a high probability of meeting the local demand throughout an outage event by keeping appropriate reserves for Diesel generation and battery discharge. In contrast, the easier to handle ICC model guarantees such probability only individually for different time steps, resulting in a much less robust dispatch. The even simpler EVM focuses solely on average values of random variables. We illustrate the four models through a comparison of outcomes attained from a real mini-grid in Lake Victoria, Tanzania. The results show the dispatch modifications for battery and Diesel reserve planning, with the JCC model providing the most robust results, albeit with a small increase in costs.</p></div>","PeriodicalId":8215,"journal":{"name":"Annals of Operations Research","volume":"344 1","pages":"499 - 531"},"PeriodicalIF":4.4,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10479-024-06287-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An axiomatization of the Shapley mapping using strong monotonicity in interval games","authors":"Shinichi Ishihara, Junnosuke Shino","doi":"10.1007/s10479-024-06271-3","DOIUrl":"10.1007/s10479-024-06271-3","url":null,"abstract":"<div><p>Interval games are an extension of cooperative coalitional games in which players are assumed to face payoff uncertainty. Characteristic functions thus assign a closed interval instead of a real number. In this paper, we focus on interval game versions of Shapley values. First, we modify Young’s strong monotonicity axiom for coalitional games into two versions so that they can be applied to the Shapley mapping and show that this can be axiomatized within the entire class of interval games using either version. Second, we derive the Shapley mapping for specific examples by employing two approaches used in the proof of the axiomatization and argue that our approach effectively works for a wide range of interval games.</p></div>","PeriodicalId":8215,"journal":{"name":"Annals of Operations Research","volume":"345 1","pages":"147 - 168"},"PeriodicalIF":4.4,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10479-024-06271-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143109274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A generalized ASIP with arrivals to all sites and particle movements in all directions","authors":"Yaron Yeger, Uri Yechiali","doi":"10.1007/s10479-024-06263-3","DOIUrl":"10.1007/s10479-024-06263-3","url":null,"abstract":"<div><p>A generalized <i>n</i>-site Asymmetric Simple Inclusion Process (ASIP) network is studied, where gate-opening instants are determined by a renewal process and arrivals occur to all sites. Various types of batch particle movements between sites are analyzed: (i) unidirectional probabilistic forward movements; (ii) probabilistic forward movements combined with feedback to the first site; and (iii) general probabilistic multidirectional movements. In contrast to the tedious successive substitution method used in previous ASIP studies, an efficient matrix approach is applied to derive the multidimensional probability generating function (PGF) of site occupancies right after gate opening instants. The complexity of the ASIP processes allows us to obtain explicit PGF results for small-size networks only, while for larger networks, a formula to calculate the mean site occupancies is derived for all types of movements. In movement case (i) the means are directly and explicitly calculated. For movement case (ii), where the network is homogeneous with equal probabilities of forward movements from site <i>i</i> to downstream sites <span>(j ge i)</span>, we show that the ratio between the mean occupancies of consecutive sites approaches a constant when the network becomes large, and calculate this ratio. Finally, we investigate an <i>n</i>-site network where at gate opening instants all gates open simultaneously, and particles move in all directions. Numerical examples are presented.</p></div>","PeriodicalId":8215,"journal":{"name":"Annals of Operations Research","volume":"343 1","pages":"515 - 542"},"PeriodicalIF":4.4,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10479-024-06263-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Zeynep Alparslan Gök, René van den Brink, Osman Palancı
{"title":"Moore interval subtraction and interval solutions for TU-games","authors":"S. Zeynep Alparslan Gök, René van den Brink, Osman Palancı","doi":"10.1007/s10479-024-06265-1","DOIUrl":"10.1007/s10479-024-06265-1","url":null,"abstract":"<div><p>Standard solutions for cooperative transferable utility (TU-) games assign to every player in a TU-game a real number representing the player’s payoff. In this paper, we introduce interval solutions for TU-games which assign to every player in a game a <i>payoff interval</i>. Even when the worths of coalitions are known, it might be that the individual payoff of a player is not known. According to an interval solution, every player knows at least a lower- and upper bound for its individual payoff. Therefore, interval solutions are useful when there is uncertainty about the payoff allocation even when the worths that can be earned by coalitions are known. Specifically, we consider two interval generalizations of the famous Shapley value that are based on marginal contributions in terms of intervals. To determine these marginal interval contributions, we apply the subtraction operator of Moore. We provide axiomatizations for the class of totally positive TU-games. We also show how these axiomatizations can be used to extend any linear TU-game solution to an interval solution. Finally, we illustrate these interval solutions by applying them to sequencing games.</p></div>","PeriodicalId":8215,"journal":{"name":"Annals of Operations Research","volume":"343 1","pages":"293 - 311"},"PeriodicalIF":4.4,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10479-024-06265-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mean-variance optimization with inferred regimes","authors":"Leonard MacLean, Yonggan Zhao, Oufan Zhang","doi":"10.1007/s10479-024-06267-z","DOIUrl":"10.1007/s10479-024-06267-z","url":null,"abstract":"<div><p>The dynamics of financial time series display a cyclical behavior, and the performance of portfolio decisions based on the anticipated distribution of asset returns are sensitive to the alignment of the anticipated distribution and subsequently observed returns in cyclical markets. We consider that the financial market is characterized by factors, and we present a regime-switching auto-regressive model for macro-economic factors to reflect financial cycles. We then define a factor model for the distribution of asset returns, with returns depending on regimes through the factors. The dependence is on the regime sequence in successive periods, or the regime transition. The factor model structure is embedded in the asset expected returns and their corresponding covariance matrix. These regime-dependent parameters serve as the inputs to mean-variance optimization, thereby constructing portfolios adapted to the current market environment. A contrast between investment decisions based on the expectation over regimes or the selection of a single most likely (inferred) regime is provided. The improvements in portfolio performance are calibrated with market data on macroeconomic factors and exchange traded funds as investment instruments.\u0000</p></div>","PeriodicalId":8215,"journal":{"name":"Annals of Operations Research","volume":"346 1","pages":"341 - 368"},"PeriodicalIF":4.4,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143638256","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}