Download or read book Distributionally Robust Inventory Management with Advance Purchase Contracts written by Yilin Xue and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: We propose a distributionally robust inventory model for finding an optimal ordering policy that attains the minimum worst-case expected total cost. In a classical stochastic setting, this problem is typically addressed by dynamic programming and is solved by the famous base-stock policy. This approach however crucially relies on two controversial assumptions: the demands are serially independent and the demand distribution is perfectly known. Aiming to address these issues, inspired by the seminal work of Scarf (1958), we adopt a mean-variance ambiguity set that imposes neither the shape of each marginal demand distribution nor their independence structure, and we focus on the case of advance purchase agreements which are prevalent in the robust inventory literature and have drawn renewed attention because of the Covid-19 vaccine procurement. The proposed distributionally robust inventory model provably reduces to a finite conic optimization problem with however an exponential number of constraints. To gain tractability and to err on the safe side, we propose two conservative approximations. The first approximation is obtained by recognizing the problem as an artificial two-stage robust optimization problem and then by restricting each adaptive decision to a linear decision rule. The second approximation, on the other hand, is obtained by a constraint partitioning and by upper bounding each resultant maximum sum with a sum of maxima. We then present a progressive approximation based on a scenario reduction technique to gauge the quality of the proposed conservative approximations. We prove that this progressive approximation is exact when the inventory problem consists of two periods, and besides we use it to show that our conservative solutions are still close to being optimal when the planning horizon is longer. All of our exact and approximate inventory models are expressed as standard conic programs which allow for the incorporation of additional distributional information. The extensions are readily obtained by deriving a new cone that corresponds to the restricted ambiguity set and embedding it in the original problems. We analytically derive the worst-case demand distribution from the mean-variance ambiguity set and numerically use it to show that our robust inventory policy is more resilient to the misspecification of the demand distribution than the state-of-the-art non-robust policies.
Download or read book Distributionally Robust Omnichannel Stocking Decisions in Quick Fulfillment Systems written by Louis Chen and published by . This book was released on 2019 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work is inspired by the daily operations of Hema supermarket, which is a recently established “new retail” model by Alibaba Group, China. In a Hema supermarket store, a single SKU may be presented with demand in the form of multiple channels. The challenge facing Hema is to stock inventory between the warehouse and the store-front in advance of uncertain demand that arises in several consecutive time frames, each 30 minutes long. Using historical sales data provided by Alibaba, we construct a distributionally robust optimization model, wherein we are to make a stocking decision robust to an adversary's choice of coupling of (marginal) demand distributions by channel and by time frame. The adversary's decision amounts to designing a random mathematical program with equilibrium constraints (MPEC). And we provide both a structural analysis of the adversary's choice of coupling as well as an efficient procedure to find this coupling. Though the distributionally robust stocking problem is non-concave in general, we provide sufficient conditions on the cost parameters for which this problem is concave, and hence tractable. Finally, in data experiments, we compare and contrast the performance of our distributionally robust solution with the performance of a Newsvendor-like solution implemented at Alibaba on various SKUs of varying sales volume and number of channels. The results indicate that the distributionally robust solutions generally outperform the Newsvendor-like solution. Interestingly, in all experiments, the distributionally robust inventory problems presented by the historical data provided by Hema are in fact concave.
Download or read book Bulletin of the Atomic Scientists written by and published by . This book was released on 1953-05 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Bulletin of the Atomic Scientists is the premier public resource on scientific and technological developments that impact global security. Founded by Manhattan Project Scientists, the Bulletin's iconic "Doomsday Clock" stimulates solutions for a safer world.
Download or read book Federal Contract Compliance Manual written by United States. Office of Federal Contract Compliance Programs and published by . This book was released on 1990 with total page 1110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Single Period Inventory Control and Pricing written by Emel Arikan and published by Forschungsergebnisse der Wirtschaftsuniversität Wien. This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The price-setting newsvendor model is used to address the single period joint pricing and inventory control problem. The objective is to set the optimal price and replenishment quantity of a single product in order to maximize the expected profit. Products with a short selling season and relatively long replenishment lead times such as fashion goods are the most relevant application areas of the model. The focus of the work is the generalization of the model with respect to the modeling of uncertainty in demand. The author presents an analytical and empirical study which compares different demand models with a more flexible model based on price and inventory optimization. She concludes that using a general model can increase the profits significantly.
Download or read book Problems Solutions in Inventory Management written by Dinesh Shenoy and published by Springer. This book was released on 2017-10-05 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a compilation of over 200 numerical problems and solutions that students can use to learn, practice and master the Inventory Control and Management concepts. Intended as a companion to any of the standard textbooks in Inventory Control and Management and written in simple language, it illustrates very clearly the steps students need to follow in order to solve a given problem. It also explains which solution methodologies can be used under which circumstances. Offering an ideal one-stop resource for mid-level engineering and business students who have taken Inventory Management or a related subject as an elective, this book is the only one students will ever need to prepare and gain confidence for their examinations in this subject.
Download or read book Lectures on Stochastic Programming written by Alexander Shapiro and published by SIAM. This book was released on 2009-01-01 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optimization problems involving stochastic models occur in almost all areas of science and engineering, such as telecommunications, medicine, and finance. Their existence compels a need for rigorous ways of formulating, analyzing, and solving such problems. This book focuses on optimization problems involving uncertain parameters and covers the theoretical foundations and recent advances in areas where stochastic models are available. Readers will find coverage of the basic concepts of modeling these problems, including recourse actions and the nonanticipativity principle. The book also includes the theory of two-stage and multistage stochastic programming problems; the current state of the theory on chance (probabilistic) constraints, including the structure of the problems, optimality theory, and duality; and statistical inference in and risk-averse approaches to stochastic programming.
Download or read book Biomass to Biofuel Supply Chain Design and Planning under Uncertainty written by Mir Saman Pishvaee and published by Academic Press. This book was released on 2020-11-25 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomass to Biofuel Supply Chain Design and Planning under Uncertainty: Concepts and Quantitative Methods explores the design and optimization of biomass-to-biofuel supply chains for commercial-scale implementation of biofuel projects by considering the problems and challenges encountered in real supply chains. By offering a fresh approach and discussing a wide range of quantitative methods, the book enables researchers and practitioners to develop hybrid methods that integrate the advantages and features of two or more methods in one decision-making framework for the efficient optimization of biofuel supply chains, especially for complex supply chain models. Combining supply chain management and modeling techniques in a single volume, the book is beneficial for graduate students who no longer need to consult subject-specific books alongside mathematical modeling textbooks. The book consists of two main parts. The first part describes the key components of biofuel supply chains, including biomass production, harvesting, collection, storage, preprocessing, conversion, transportation, and distribution. It also provides a comprehensive review of the concepts, problems, and opportunities associated with biofuel supply chains, such as types and properties of the feedstocks and fuel products, decision-making levels, sustainability concepts, uncertainty analysis and risk management, as well as integration of biomass supply chain with other supply chains. The second part focuses on modeling and optimization of biomass-to-biofuel supply chains under uncertainty, using different quantitative methods to determine optimal design. Proposes a general multi-level framework for the optimal design and operation of biomass-to-biofuel supply chains through quantitative analysis and modeling, including different biomass and waste biomass feedstock, production pathways, technology options, transportation modes, and final products Explores how modeling and optimization tools can be utilized to address sustainability issues in biofuel supply chains by simultaneously assessing and identifying sustainable solutions Presents several case studies with different regional constraints to evaluate the practical applicability of different optimization methods and compares their performance in real-world situations Includes General Algebraic Modeling System (GAMS) codes for solving biomass supply chain optimization problems discussed in different chapters
Download or read book Social Science Research written by Anol Bhattacherjee and published by CreateSpace. This book was released on 2012-04-01 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is designed to introduce doctoral and graduate students to the process of conducting scientific research in the social sciences, business, education, public health, and related disciplines. It is a one-stop, comprehensive, and compact source for foundational concepts in behavioral research, and can serve as a stand-alone text or as a supplement to research readings in any doctoral seminar or research methods class. This book is currently used as a research text at universities on six continents and will shortly be available in nine different languages.
Download or read book Varieties of Capitalism written by Peter A. Hall and published by Oxford University Press. This book was released on 2001 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: Applying the new economics of organisation and relational theories of the firm to the problem of understanding cross-national variation in the political economy, this volume elaborates a new understanding of the institutional differences that characterise the 'varieties of capitalism' worldwide.
Download or read book Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation written by Intergovernmental Panel on Climate Change and published by Cambridge University Press. This book was released on 2012-05-28 with total page 593 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extreme weather and climate events, interacting with exposed and vulnerable human and natural systems, can lead to disasters. This Special Report explores the social as well as physical dimensions of weather- and climate-related disasters, considering opportunities for managing risks at local to international scales. SREX was approved and accepted by the Intergovernmental Panel on Climate Change (IPCC) on 18 November 2011 in Kampala, Uganda.
Download or read book The Power of Resilience written by Yosef Sheffi and published by MIT Press. This book was released on 2015-09-11 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work focuses on deep-tier risks, corporate social responsibility risks, cybersecurity risks, global raw material risks, long-term disruptions, business continuity planning, risk and disruption detection, and the potential for systemic disruptions.
Download or read book The Green Book written by Great Britain. Treasury and published by Stationery Office. This book was released on 2003 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new edition incorporates revised guidance from H.M Treasury which is designed to promote efficient policy development and resource allocation across government through the use of a thorough, long-term and analytically robust approach to the appraisal and evaluation of public service projects before significant funds are committed. It is the first edition to have been aided by a consultation process in order to ensure the guidance is clearer and more closely tailored to suit the needs of users.
Download or read book Economic Policy for a Pandemic Age written by Monica de Bolle and published by Peterson Institute for International Economics. This book was released on 2021-04-05 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: The global health and economic threats from the COVID-19 pandemic are not yet behind us. While the development of multiple safe and highly effective vaccines in less than a year is cause for hope, several significant dangers to recovery of global health and income are still clear and present: New concerning variants of SARS-CoV-2, the virus that causes COVID-19, continue to emerge at an alarming rate in different parts of the world; at the same time, vaccine rollouts have been shockingly inefficient even in some rich countries, while much of the developing world waits in line behind them for vaccines to arrive. The Briefing covers several policy areas in which cooperative forward-looking policy action will materially improve our chances of truly escaping today's pandemic and making future pandemics less costly.
Download or read book Logistics Transportation Systems written by MD Sarder and published by Elsevier. This book was released on 2020-10-17 with total page 455 pages. Available in PDF, EPUB and Kindle. Book excerpt: Logistics Transportation Systems compiles multiple topics on transportation logistics systems from both qualitative and quantitative perspectives, providing detailed examples of real-world logistics workflows. It explores the key concepts and problem-solving techniques required by researchers and logistics professionals to effectively manage the continued expansion of logistics transportation systems, which is expected to reach an estimated 25 billion tons in the United States alone by 2045. This book provides an ample understanding of logistics transportation systems, including basic concepts, in-depth modeling analysis, and network analysis for researchers and practitioners. In addition, it covers policy issues related to transportation logistics, such as security, rules and regulations, and emerging issues including reshoring. This book is an ideal guide for academic researchers and both undergraduate and graduate students in transportation modeling, supply chains, planning, and systems. It is also useful to transportation practitioners involved in planning, feasibility studies, consultation and policy for transportation systems, logistics, and infrastructure. Provides real-world examples of logistics systems solutions for multiple transportation modes, including seaports, rail, barge, road, pipelines, and airports Covers a wide range of business aspects, including customer service, cost, and decision analysis Features key-term definitions, concept overviews, discussions, and analytical problem-solving
Download or read book An Evolutionary Theory of Economic Change written by Richard R. Nelson and published by Harvard University Press. This book was released on 1985-10-15 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the most sustained and serious attack on mainstream, neoclassical economics in more than forty years. Nelson and Winter focus their critique on the basic question of how firms and industries change overtime. They marshal significant objections to the fundamental neoclassical assumptions of profit maximization and market equilibrium, which they find ineffective in the analysis of technological innovation and the dynamics of competition among firms. To replace these assumptions, they borrow from biology the concept of natural selection to construct a precise and detailed evolutionary theory of business behavior. They grant that films are motivated by profit and engage in search for ways of improving profits, but they do not consider them to be profit maximizing. Likewise, they emphasize the tendency for the more profitable firms to drive the less profitable ones out of business, but they do not focus their analysis on hypothetical states of industry equilibrium. The results of their new paradigm and analytical framework are impressive. Not only have they been able to develop more coherent and powerful models of competitive firm dynamics under conditions of growth and technological change, but their approach is compatible with findings in psychology and other social sciences. Finally, their work has important implications for welfare economics and for government policy toward industry.
Download or read book Data Intensive Text Processing with MapReduce written by Jimmy Lin and published by Springer Nature. This book was released on 2022-05-31 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our world is being revolutionized by data-driven methods: access to large amounts of data has generated new insights and opened exciting new opportunities in commerce, science, and computing applications. Processing the enormous quantities of data necessary for these advances requires large clusters, making distributed computing paradigms more crucial than ever. MapReduce is a programming model for expressing distributed computations on massive datasets and an execution framework for large-scale data processing on clusters of commodity servers. The programming model provides an easy-to-understand abstraction for designing scalable algorithms, while the execution framework transparently handles many system-level details, ranging from scheduling to synchronization to fault tolerance. This book focuses on MapReduce algorithm design, with an emphasis on text processing algorithms common in natural language processing, information retrieval, and machine learning. We introduce the notion of MapReduce design patterns, which represent general reusable solutions to commonly occurring problems across a variety of problem domains. This book not only intends to help the reader "think in MapReduce", but also discusses limitations of the programming model as well. Table of Contents: Introduction / MapReduce Basics / MapReduce Algorithm Design / Inverted Indexing for Text Retrieval / Graph Algorithms / EM Algorithms for Text Processing / Closing Remarks
