Roberto Baviera, Carlo Sgarra, Tiziano Vargiolu, Rituparna Sen
{"title":"Foreword to the Special Issue on Energy Finance and Climate Change","authors":"Roberto Baviera, Carlo Sgarra, Tiziano Vargiolu, Rituparna Sen","doi":"10.1002/asmb.2909","DOIUrl":"https://doi.org/10.1002/asmb.2909","url":null,"abstract":"","PeriodicalId":55495,"journal":{"name":"Applied Stochastic Models in Business and Industry","volume":"40 6","pages":"1470-1471"},"PeriodicalIF":1.3,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142868033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Is (Independent) Subordination Relevant in Equity Derivatives?","authors":"Michele Azzone, Roberto Baviera","doi":"10.1002/asmb.2904","DOIUrl":"https://doi.org/10.1002/asmb.2904","url":null,"abstract":"Monroe (1978) demonstrates that any local semimartingale can be represented as a time‐changed Brownian Motion (BM). A natural question arises: does this representation theorem hold when the BM and the time‐change are independent? We prove that a local semimartingale is not equivalent to a BM with a time‐change that is independent from the BM. Our result is obtained utilizing a class of additive processes: the additive normal tempered stable (ATS). This class of processes exhibits an exceptional ability to calibrate the equity volatility surface accurately. We notice that the sub‐class of additive processes that can be obtained with an independent additive subordination is incompatible with market data and shows significantly worse calibration performances than the ATS, especially on short time maturities. These results have been observed every business day in a semester on a dataset of S&P 500 and EURO STOXX 50 options.","PeriodicalId":55495,"journal":{"name":"Applied Stochastic Models in Business and Industry","volume":"22 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Renewable Energy Investments, Support Schemes and the Dirty Option","authors":"Domenico De Giovanni, Elena Iakimova","doi":"10.1002/asmb.2901","DOIUrl":"https://doi.org/10.1002/asmb.2901","url":null,"abstract":"<p>In a real options framework, we analyze the behavior of a large energy producer who can invest in a portfolio of Renewable Energy Source (RES) and <i>dirty</i> energy source. Competitive fuel prices challenge the investments in RES. Given a budget constraint, the agent allocates the optimal capacities of both energy instalments and selects the optimal investment time. We use the model to compare the effectiveness of classical support schemes such as Feed-in Tariffs or Green Certificate with respect to forms of taxation of dirty technology such as Carbon Taxes or Carbon Permits. This paper proposes a conceptual framework and qualitative analysis to understand which support system enhances the attractiveness of renewable energy investments.</p>","PeriodicalId":55495,"journal":{"name":"Applied Stochastic Models in Business and Industry","volume":"40 6","pages":"1472-1483"},"PeriodicalIF":1.3,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asmb.2901","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142869080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tevfik Aktekin, Bumsoo Kim, Luis J. Novoa, Babak Zafari
{"title":"Bayesian Sequential Learning and Decision Making in Bike-Sharing Systems","authors":"Tevfik Aktekin, Bumsoo Kim, Luis J. Novoa, Babak Zafari","doi":"10.1002/asmb.2888","DOIUrl":"https://doi.org/10.1002/asmb.2888","url":null,"abstract":"<div>\u0000 \u0000 <p>In this article, we introduce modeling strategies for sequentially learning various types of demand uncertainty in bike-share networks and propose methods for optimal station inventory management. Our approach is motivated by a real bike-share network in Seoul, South Korea, with 40,000 bikes over a network of 2500 stations covering 25 municipal districts. In doing so, we consider novel Bayesian state space models that are suitable for fast and efficient learning of dynamically evolving system parameters for both intra-day and inter-week planning horizons. Our proposed approach provides an overall solution for operation managers where sequential parameter updating, demand prediction, and inventory decision making are addressed simultaneously and is straightforward to implement for the end-user. We illustrate how our approach can be applied to a large metropolitan area like Seoul and discuss practical implementation insights.</p>\u0000 </div>","PeriodicalId":55495,"journal":{"name":"Applied Stochastic Models in Business and Industry","volume":"40 6","pages":"1675-1688"},"PeriodicalIF":1.3,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142868946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stefano Chiaradonna, Petar Jevtić, Nicolas Lanchier, Sasa Pesic
{"title":"Framework for Cyber Risk Loss Distribution of Client-Server Networks: A Bond Percolation Model and Industry Specific Case Studies","authors":"Stefano Chiaradonna, Petar Jevtić, Nicolas Lanchier, Sasa Pesic","doi":"10.1002/asmb.2896","DOIUrl":"https://doi.org/10.1002/asmb.2896","url":null,"abstract":"<div>\u0000 \u0000 <p>Cyber risk has emerged as a significant threat to businesses that have increasingly relied on new and existing information technologies (IT). Across various businesses in different industries and sectors, a distinct pattern of IT network architectures, such as the client-server network architecture, may, in principle, expose those businesses, which share it, to similar cyber risks. That is why in this article, we propose a probabilistic structural framework for loss assessments of cyber risks on the class of client-server network architectures with <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>K</mi>\u0000 </mrow>\u0000 <annotation>$$ K $$</annotation>\u0000 </semantics></math> different client types. To our knowledge, there exist no theoretical models of an aggregate loss distribution for cyber risk in this setting. With this structural framework via the exact mean and variance of losses, we demonstrate how the changing cybersecurity environment of a business's IT network impacts the loss distribution. Furthermore, our framework provides insights into better investment strategies for cybersecurity protection on the client-server network. Motivated by cyberattacks across industries, we apply our framework to four case studies that utilize the client-server network architecture. Our first application is implantable medical devices in healthcare. Our second application is the smart buildings domain. Third, we present an application for ride-sharing services such as Uber and Lyft. The fourth is the application of vehicle-to-vehicle cooperation in traffic management. The results are corresponding exact means and variances of cyber risk loss distributions parameterized by various cybersecurity parameters allowing for liability assessments and decisions in cybersecurity protection investments.</p>\u0000 </div>","PeriodicalId":55495,"journal":{"name":"Applied Stochastic Models in Business and Industry","volume":"40 6","pages":"1712-1733"},"PeriodicalIF":1.3,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142868212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Guido Lagos, Javiera Barrera, Pablo Romero, Juan Valencia
{"title":"Limiting Behavior of Mixed Coherent Systems With Lévy-Frailty Marshall–Olkin Failure Times","authors":"Guido Lagos, Javiera Barrera, Pablo Romero, Juan Valencia","doi":"10.1002/asmb.2893","DOIUrl":"https://doi.org/10.1002/asmb.2893","url":null,"abstract":"<div>\u0000 \u0000 <p>In this article, we show a limit result for the reliability function of a system—that is, the probability that the whole system is still operational after a certain given time—when the number of components of the system grows to infinity. More specifically, we consider a sequence of mixed coherent systems whose components are homogeneous and non-repairable, with failure-times governed by a Lévy-Frailty Marshall–Olkin (LFMO) distribution—a distribution that allows simultaneous component failures. We show that under integrability conditions the reliability function converges to the probability of a first-passage time of a Lévy subordinator process. To the best of our knowledge, this is the first result to tackle the asymptotic behavior of the reliability function as the number of components of the system grows. To illustrate our approach, we give an example of a parametric family of reliability functions where the system failure time converges in distribution to an exponential random variable, and give computational experiments testing convergence.</p>\u0000 </div>","PeriodicalId":55495,"journal":{"name":"Applied Stochastic Models in Business and Industry","volume":"40 5","pages":"1229-1244"},"PeriodicalIF":1.3,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Foreword to the Special Issue on Mathematical Methods in Reliability (MMR23)","authors":"Félix Belzunce, Jorge Navarro","doi":"10.1002/asmb.2894","DOIUrl":"https://doi.org/10.1002/asmb.2894","url":null,"abstract":"<p>The 12th International Conference on Mathematical Methods in Reliability (MMR 2023, May 30–June 2, Murcia Spain) continues a distinguished tradition of bringing together leading experts, researchers, and practitioners from various fields to explore cutting-edge advancements in reliability theory and applications. Since its inception, the MMR conference series has provided a premier platform for exchanging ideas and promoting collaboration across a wide array of disciplines, including mathematics, engineering, statistics, operations research, and computer science.</p><p>Reliability theory plays a crucial role in designing and analyzing complex systems, where safety, dependability, and risk assessment are paramount. As technological advancements accelerate and systems become increasingly intricate, the demand for robust mathematical models and methods to ensure system reliability is more critical than ever.</p><p>As the world faces new challenges in ensuring the resilience and reliability of critical infrastructures and technologies, the MMR conference continues to inspire innovation and foster collaboration. We hope this collection of papers will provide readers with valuable insights and stimulate further research in this vibrant and essential field.</p>","PeriodicalId":55495,"journal":{"name":"Applied Stochastic Models in Business and Industry","volume":"40 5","pages":"1206-1208"},"PeriodicalIF":1.3,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asmb.2894","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Application of Hawkes Volatility in the Observation of Filtered High-Frequency Price Process in Tick Structures","authors":"Kyungsub Lee","doi":"10.1002/asmb.2892","DOIUrl":"https://doi.org/10.1002/asmb.2892","url":null,"abstract":"<p>The Hawkes model is suitable for describing self and mutually exciting random events. In addition, the exponential decay in the Hawkes process allows us to calculate the moment properties of the model. However, owing to the complexity of the model and formula, few studies have examined the Hawkes volatility. In this study, we derive a variance formula that is directly applicable under the general settings of both unmarked and marked Hawkes models for tick-level price dynamics. In the marked model, the linear impact function and possible dependency between the marks and underlying processes are considered. The Hawkes volatility is applied to the mid-price process filtered at 0.1-s intervals to show reliable results. Furthermore, intraday estimation is expected to widely utilized in real-time risk management. We also note the increasing predictive power of the intraday Hawkes volatility over time and examine the relationship between futures and stock volatilities.</p>","PeriodicalId":55495,"journal":{"name":"Applied Stochastic Models in Business and Industry","volume":"40 6","pages":"1689-1711"},"PeriodicalIF":1.3,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asmb.2892","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142868037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. V. Ballestra, V. D'Amato, P. Fersini, S. Forte, F. Greco
{"title":"Pricing Cyber Insurance: A Geospatial Statistical Approach","authors":"L. V. Ballestra, V. D'Amato, P. Fersini, S. Forte, F. Greco","doi":"10.1002/asmb.2891","DOIUrl":"https://doi.org/10.1002/asmb.2891","url":null,"abstract":"<p>Cyberspace is a dynamic ecosystem consisting of interconnected data, devices, and individuals, with multiple network layers comprising identifiable nodes. Location-based information can significantly improve cyber resilience decision-making and facilitate the development of innovative cyber risk pricing tools. This article is based on a methodology that uses company geospatial data to accurately estimate the number of expected losses arising from cyberattacks. Our approach aims to build and compare statistical spatial models that allow pricing cyber policies more effectively than traditional non-spatial methods by incorporating all available data. By accounting for spatial dependence, we can assess the risk of data breaches and contribute to the design of more efficient cyber risk policies for the insurance market.</p>","PeriodicalId":55495,"journal":{"name":"Applied Stochastic Models in Business and Industry","volume":"40 5","pages":"1365-1376"},"PeriodicalIF":1.3,"publicationDate":"2024-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asmb.2891","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Regional Shopping Objectives in British Grocery Retail Transactions Using Segmented Topic Models","authors":"Mariflor Vega Carrasco, Mirco Musolesi, Jason O'Sullivan, Rosie Prior, Ioanna Manolopoulou","doi":"10.1002/asmb.2890","DOIUrl":"https://doi.org/10.1002/asmb.2890","url":null,"abstract":"Understanding the customer behaviours behind transactional data has high commercial value in the grocery retail industry. Customers generate millions of transactions every day, choosing and buying products to satisfy specific shopping needs. Product availability may vary geographically due to local demand and local supply, thus driving the importance of analysing transactions within their corresponding store and regional context. Topic models provide a powerful tool in the analysis of transactional data, identifying topics that display frequently‐bought‐together products and summarising transactions as mixtures of topics. We use the segmented topic model (STM) to capture customer behaviours that are nested within stores. STM not only provides topics and transaction summaries but also topical summaries at the store level that can be used to identify regional topics. We summarise the posterior distribution of STM by post‐processing multiple posterior samples and selecting semantic modes represented as recurrent topics, and employ Gaussian process regression to model topic prevalence across British territory while accounting for spatial autocorrelation. We implement our methods on a dataset of transactional data from a major UK grocery retailer and demonstrate that shopping behaviours may vary regionally and nearby stores tend to exhibit similar regional demand.","PeriodicalId":55495,"journal":{"name":"Applied Stochastic Models in Business and Industry","volume":"19 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}