17 research outputs found
Adapting to a Changing Landscape : How Chinese Companies Can Learn from Japanese Corporate Transformation in the Post-Bubble Era
No full text亜細亜大学修士（経営学）master thesi
X-ray fluorescence scanning data (Ca, Ti, Fe, Ba) of sediment core GeoB12605-3
No full textX-ray fluorescence scanning data (Ca, Ti, Fe, Ba) of sediment core GeoB12605-
Impaired directed forgetting in abstinent heroin addicts
No full textDrug-related memories persist long into abstinence and are potent elicitors of drug craving and relapse. We report two experiments examining whether heroin-dependent individuals are impaired in intentionally suppressing drug-related memories. Experiment 1 adopted the Item paradigm where addicts and healthy controls were presented with a list of words each followed by a remember or forget cue. Experiment 2 adopted the List paradigm where they studied one list of items and were then split into a remember group and a forget group. Both groups studied a second list, except that the forget group was told to forget the first list. Compared with controls, addicts showed a reduced directed forgetting effect in the Item method and a total absence of one measure of directed forgetting in the List method (List 2 benefits). Results indicate that heroin addicts are impaired in directed forgetting and that the deficits are likely associated with memory encoding as opposed to retrieval. Possible problems include reduced ability in actively suppressing/stopping encoding of irrelevant information into memory or inability in changing/resetting encoding strategies. In neither experiment did the addicts show any differential directed forgetting effects between drug-related words and neutral words, indicating the generic nature of their intentional forgetting deficits
Topographic and Climatic Control on Chemical Weathering of Mountainous Riverine Sediments of Hainan Island, South China Sea
No full textHainan Island, the largest island in the northwestern South China Sea (SCS), is characterized by many tropical mountainous rivers that flow into the SCS. The geochemistry of these riverine sediments and the factors controlling the weathering intensity are still not well understood. In this study, sedimentary geochemistry has been investigated by using 45 riverine sediments collected from 18 major rivers on Hainan Island. The Hainan riverine sediments are only first-cycle rather than polycyclic sediments, and they faithfully reflect the present weathering intensity. The high and steady values of the Chemical Index of Alteration (CIA) indicate that the riverine sediments at different parts of the Hainan Island have overall undergone intensive chemical weathering. The low values of Weathering Index of Parker (WIP) and high alpha(Ca) , alpha(K), alpha(Sr), and alpha(Ba) values of north Hainan indicate the highest weathering degree, which is mainly influenced by the flat topography. The values of alpha(Na) , alpha(K), alpha(Sr), and alpha(Ba) of southwest Hainan which are higher than those of east Hainan suggest that the leaching of elements such as Na, K, Sr, and Ba is more extreme (i.e., more intensive weathering). These are mainly caused by the different physical denudation due to different summer precipitation. Overall, the Hainan Island is featured by intensive chemical weathering and is classified as a typical transport-limited weathering regime. Therefore, the geochemistry of the riverine sediments of the Hainan Island is different from that of sediments in tectonically active regions (e.g., Taiwan Island)
Dynamic inventory and pricing management with total minimum commitment contracts and positive lead times
No full textM.Phil.We study the optimal joint inventory and pricing policy for a system with positive lead times and total minimum commitment (TMC) contracts over a finite planning horizon. Under demand backlogging assumption and an additive demand model, we formulate a dynamic programming model and use the concept of multimodularity to obtain structural results of the optimal policy. We prove that the value function is both a monotone and multimodular function, and derivatives of the optimal pricing and ordering policies with respect to inventory levels and committed quantity are bounded. We also show convergence results on the value function and optimal policy as the committed quantity goes infinity. These findings make the optimal policy directly cornputable for cases with short lead times. For general lead times, however , the computation is intractable due to t he curse of dimensionality. Therefore, we develop a simple yet near-optimal heuristic policy. We use price-deflated inventory position to weighted aggregating the on-hand and pipeline inventory into a single state variable, and propose the pricing and ordering policy. Besides, we propose a benchmark policy based on dynamically adjusted static pricing in order to compare its performance with the heuristic. Finally, a numerical study is conducted to evaluate the performance of the heuristic. The numerical results show that under different positive lead times and finite planning horizons, the heuristic is near-optimal when comparing expected profits with the optimal system and the heuristic performs better than the benchmark. The performance of t he heuristic t ends to be better as the demand variability decreases, as the mean demand price sensitivity decreases, and as the unit backlogging cost decreases.本文研究了存在采购提前期和最小承诺合同下的最优定价和订货问题。我们假设系统中允许积压待配订货，并且需求是与定价相关的加和形式，进而建立了动态规划模型并进一步对最优定价和订货策略的结构性质进行了分析。通过分析价值函数，我们证明了它既是一个关于契约订货量递减的函数，也是一个凹函数。同时，我们证明了库存与契约订货量的经济替代关系。通过分析最优策略，我们发现最优定价和订货策略关于库存量和契约订货量的偏导数存在上限和下限。并且，当任承诺订货量趋于无穷时，我们提出了求解最优订货量收敛值的方法。当采购提前期较小时，这些结论使得最优策略较容易得到。然而，采购提前期增大会导致计算困难，因此我们提出了通过将所有库存状态变量加权和为一个状态变量，进而降低状态变量的维数的启发式算法。另外，我们提出了一个基于静态定价的基准算法，用以在数值实验中对比启发式算法。通过数值分析，我们发现在不同的采购提前期和合同期限下，启发式算法均展现了其优异性。我们进一步分析了不同初始库存、不同初始契约订货量、需求波动等对于算法造成的影响，不同范围的数值实验验证了算法的优异表现。Ma, Ning.Thesis M.Phil. Chinese University of Hong Kong 2019.Includes bibliographical references (leaves 39-43).Abstracts also in Chinese.Title from PDF title page (viewed on 01, December, 2020)
Studies of return policies: consumer review and channel structure
No full textPh.D.Product return has become a great concern for retailers as the volume and cost of returns increase. The U.S. electronics industry alone spentIn the first study, we investigate the interplay between return policy, pricing strategy, and consumer reviews. We consider a two-period model in which consumers in the first period give reviews depending on their ex post utility. These reviews affect the valuation of the product for consumers in the second period. We characterize the optimal pricing strategy and investigate how consumer reviews affect the pricing decision under different return policies. We also study how the retailer should choose from the no refund policy and the full refund policy. Furthermore, we extend our results to the partial refund case in which the retailer can decide the price and the refund. We demonstrate how the problem parameters may affect the optimal price and refund decisions by numerical experiments.The second study is motivated by the emerging trend that online retailers set up offline channels. Consumers can resolve valuation uncertainty by visiting an offline channel and avoid purchasing mismatched product. Therefore, the channel structure can be a tool to manage returns. First, we consider that the retailer sets the same price for both channels. We study the pricing strategy under different channel structures and quantify the benefits of opening a showroom or a physical store for an online retailer. Traditionally, the retailer only allows consumers to return their purchase to the channel where they buy it. Omnichannel retailing is a growing trend for retailers, in which consumers can buy and return the product from any channel they like. We obtain the optimal price for the omnichannel retailer and characterize the conditions when the retailer should adopt omnichannel retailing. We also extend our study to the case that the retailer can set different prices for different channels. We derive the optimal prices for the dual-channel and omnichannel retailer. And we characterize when omnichannel retailing is more beneficial.隨著退貨的增多和退貨赴理成本的增加，退貨愈友成方零售商面汁的重要何題。仗美園屯子行~一年中便在退貨伺題上花費了138把美元，而被退汪的戶品中{又有%存在瑕疵。天才零售咆商而吉?由於消費者元法接他體磁戶品，退貨何題交得更方戶峻。阿炳用戶需收到商品，才能硝定商品的份值。本文以消費者財物汗洽以及渠道站拘兩小角度，未研究遠不中份值不硝定引起的退貨何題。在第一項研究中，我們探吋零售份格，退貨政策，和消費者坪治的相互影吶。我們考慮一令兩期模型，第一期消費者的防物汗洽，合影日向第二期消費者河商品仰值的判斷。我有]刻面了在不同退貨政策下，同絡零售商的最忱定份策略以及胸物坪洽如何影咱定份，並遊一步研究岡絡零售商如何在金額退款和不改退款中做出逃擇。我們也特結果拓展到部分退款的情形下，並通泣教值i式3金研究了其中的多數交化如何影日兩最忱定仰和退款決策。第二項研究受店友于同第咆商卉投鏡下要體店的新起勢。通泣坊伺鏡下商店，消費者可以硝定商品的份值此而消除退貨的夙隘，因而銷售渠道也是一科管理退貨的途徑。我們首先考慮了錢上鏡下同仰的情形研究了不同渠道詰拘下的定份策略，並量化了7於圾袋下展示店和錢下零售店的收益。待統零售商只允件消費者狀!MJ芙渠道退貨，而全渠道零售(新零售)浪潮下，錢上錢下渠道深度融合。元洽財物注是退貨服努，消費者都可以進捍自己偏好的渠道。我有]研究了全渠道零售商的最忱定份並給出攻渠道零售商莊岩特型方全渠道的各件。我們也特研究拓展到錢上鏡下不同仰的情形，給出了不同渠道站拘下的最忱定份並探付了何肘全渠道河零售商更均有利。Cui, Pengxiang.Thesis Ph.D. Chinese University of Hong Kong 2017.Includes bibliographical references (leaves 121-127).Abstracts also in Chinese.Title from PDF title page (viewed on 15, October, 2019)
Asymptotic optimality of simple heuristic policies for perishable and lost-sales inventory systems
No full textPh.D.Inventory control in the presence of supply risk and demand uncertainty is one of the most fundamental topics in supply chain management. In this thesis, we consider several challenging inventory systems, including the perishable system and the lost-sales system with positive lead times. The optimal policies for these models are notoriously complex and computing the optimal ordering quantity through dynamic programming is intractable due to the curse of dimensionality. Since solving the optimal policies exactly seems to be out of reach, we are interested in developing easy-to-compute yet close-to-optimal heuristic policies, and understanding how good these heuristics could be theoretically relative to the true optimal policies. To this end, we construct some simple heuristics for the inventory systems of our interest, and carry out the asymptotic analysis of these policies in several asymptotic regimes of system parameter. We demonstrate that the optimality gap of these heuristics decays to zero as some parameter tends to infinity, and also characterize the convergence rate of the optimality gap with respect to the parameter. These results not only offer theoretical understanding on the performance of simple policies, but also provide decision support for their applications in practice.There are four chapters in this thesis. In the first chapter, we provide an introduction and review the relevant literature. Chapters 2-4 are the main body of this thesis. In Chapter 2, we consider a classic periodic-review perishable inventory system with a fixed product lifetime over an infinite planning horizon. The optimal policy for this system is notoriously complex and computationally intractable. Hence, several heuristics have been proposed in the literature, among which the base-stock policies, which raise the total on-hand inventory to a constant in each period, have been shown to perform very well. While extensive numerical studies have demonstrated near-optimal performances of the base-stock policies, there is little theoretical result on their performances. In Chapter 2, we construct a simple heuristic base-stock policy, and show that the gap between its long-run average cost and the optimal cost converges to zero when any one of the product lifetime, demand size, unit outdating cost, or unit penalty cost grows large. In particular, the optimality gap decays to zero exponentially fast in the lifetime and demand size. Our numerical study demonstrates the near-optimal performance of our heuristic base-stock policy. Finally, we show that most of our results extend to a broad class of base-stock policies.In Chapter 3, we consider an infinite-horizon periodic-review lost-sales inventory model where the supply takes positive lead times and is a random function of the order quantity (e.g., random yield/capacity). The optimal policy for this model is computationally intractable; and no heuristic has been proposed in the literature. We focus on a simple class of constant-order policies (COP)that place the same order in every period, regardless of the system state. Under some assumptions on the random supply function, we prove that the best COP is asymptotically optimal with large lead times and the optimality gap converges to zero exponentially fast in the lead time. We also prove that, if the mean supply capacity is less than the mean demand, then the best COP is also asymptotically optimal with large penalty cost; otherwise, the long-run average cost of the best COP asymptotically increases at the rate of square-root of the penalty cost. Further, we construct a simple heuristic COP and show that it performs very close to the best COP. Finally, we provide a numerical study to derive further insights into the performance of the best COP.In Chapter 4, we investigate an infinite-horizon continuous-review lost-sales system with fixed replenishment lead times, where demand arrives as a Poisson process. We focus on the simple base-stock policy, which keeps the sum of the inventory on-hand and in transit at a constant at any time. We prove that as the penalty cost increases, the ratio between the long-run average costs of the best base-stock policy and the optimal policy converges to one, and therefore, the best base-stock policy is asymptotically optimal. As a by-product, we also characterize the asymptotic rate of the long-run average costs under the best base-stock policy and the optimal policy, and that of the best base-stock level as the penalty cost grows.供应和需求不确定下的库存控制是供应链管理领域的重要问题。本论文考虑了几类复杂的库存系统， 包括易腐蚀产品库存系统，缺货不补库存系统，它们的最优策略非常复杂，受到维数灾难的限制，难以通过动态规划算法求解最优订货量。由于这些系统的最优解无法实现，我们着眼于设计容易计算且接近最优的启发式算法，并且理解这些启发式算法相比于最优策略在理论上可以达到多好的效果。为此，我们对于几类复杂的库存系统提出了简单的启发式算法，并且对这些算法在某些系统参数增大的时候进行了渐进性性质的理论分析。我们证明了这些启发式算法与最优策略的成本差异随着某些系统参数的增加而趋于零，并且刻画了关于系统参数的收敛速度。这些结果不仅为这些简单的启发式算法提供了理论上的认识，也为现实中实施执行这些算法提供了基础。本论文共有四个章节，第一章我们提供了背景介绍和文献综述，第二章节至第四章节是本论文的主体部分。在第二章，我们考虑了一类经典的无穷检阅周期下的易腐蚀产品的库存系统。由于这类系统的最优策略非常复杂，难以求解，因此文献中提出了一些启发式算法，在这些启发式算法中， 一类定义为将库存总水平提高到某一常数的、被称之为基线库存策略的启发式算法的表现非常好。尽管在数值试验中，这类基线库存策略接近最优策略，文献中几乎没有任何关于这类策略表现的理论结果。在第二章，我们证明了一个简单的启发式基线库存策略与最优策略的成本差异，在生命周期，需求量，单位处理成本，或单位缺货成本增加时，都会衰减到零。特别地，关于生命周期和需求量都呈现指数衰减速度。我们的数值实验表明我们的启发式基线库存策略表现接近最优。最后，我们将本章中的大多数理论结果推广到一类更加广泛的基线库存策略。在第三章，我们研究了无穷检阅周期下的缺货不补库存模型，在这一模型里，存在采购提前期，并且供货量是订货量的不确定随机函数，例如不确定产比问题，不确定产能问题。这类模型的最优策略非常复杂，文献中也没有提出过任何启发式算法。我们考虑了一类简单的启发式算法:无论系统状态如何，每期的订货量为一常数，我们称之为常数订货量策略。在对随机供货量函数的一些假设下，我们证明了当订货提前期增加时，最优的常数订货量策略趋于最优策略，并且与最优策略的成本差关于订货提前期的增加呈现指数衰减。另外，我们证明了如果上游的期望产能小于期望需求，当缺货成本增加时，最优的常数订货量策略趋于最优策略: 否则，最优的常数订货量策略的成本增长速度近似于根号下单位缺货戚本。同时，我们构造了简单可算并且接近最优的启发式常数订货量策略，并且发现它的数值表现接近最优的常数订货量策略。最后，我们通过数值实验讨论了最优常数订货量策略的数值表现。在第四章，我们研究了无穷且连续检阅时间下的缺货不补库存系统，订货提前期为给定的正常数， 需求的到达服从泊松过程。我们考虑了一类简单的基线库存策略，它的定义是在任何时刻将于上库存水平和在途库存水平的和维持在同一常数。我们证明了当缺货成本增加， 最优基线库存策略的成本与最优策略的成本比值趋于一，因此说明了最优基线库存策略是渐进最优的。同时我们还刻画了最优成本，最优基线库存策略的成本随着单位缺货成本的增长速度，以及最优基线库存水平随着单位缺货成本的增长速度。Bu, Jinzhi.Thesis Ph.D. Chinese University of Hong Kong 2019.Includes bibliographical references (leaves 139-146).Abstracts also in Chinese.Title from PDF title page (viewed on 7, April 2021
The neural basis of conditional reasoning: an event-related potential study
No full textAbstract The spatiotemporal analysis of brain activation during the execution of conditional reasoning tasks (the four inference forms: Modus Ponens (MP), Modus Tollens (MT), affirming the consequent (AC), and denying the antecedent (DA)) and one baseline task (BS) was performed in 12 normal young adult participants using high-density event-related brain potentials (ERPs). Results showed that the early components elicited by the five task types were not significantly different. Reasoning tasks elicited a more negative EPR deflection (N600) than did the BS task in the time window of 500-700 ms after onset of the minor premise. Dipole source analysis of the difference wave (MP − BS) suggested that a generator localized in the left anterior cingulate cortex (BA 24) was involved in the activation and the application of the inference rules. ERP components of the five tasks were similar in the subsequent time period between 700 and 1700 ms. Following that period, a greater negativity in the reasoning tasks, in comparison to the BS task, developed between 1700 and 2000 ms poststimulus over the left fronto-central scalp regions. A generator of this effect was located in the right anterior cingulate cortex (BA 24) and was possibly related to cognitive control. The results indicate that the cingulate cortex was activated by conditional reasoning tasks with purely abstract materials and support the view that human reasoning is not a unified phenomenon but is content-sensitive
CUHK electronic theses & dissertations collection
No full textAdvertising is considered as an important strategic tool to promote product and improve sales. Extensive research has been devoted to advertising strategies and their effect on product sales. Chiefly because aggregate-level sales data are easy to collect, the prior studies predominately develop and analyze aggregate advertising models which relate product sales to advertising spending under a known sales response function. Nowadays, however, the emergence of Internet, e-commerce and data analytics approaches has made collecting data on individual consumer behavior and real-time sales feasible. Therefore, studying more sophisticated advertising models which can exploit these data is necessary and meaningful. In this dissertation, we consider two dynamic advertising models, one incorporates customer satisfaction and customer switching behavior and the other involves dynamic sales learning.The first model focuses on the markets of experience goods whose quality levels are unobservable to the buyers. The buyers make the purchase decisions based on their past usage experience of the goods and the advertising outlays of the sellers. We first consider the competitive market where there are multiple brands planning their advertising campaigns. We derive the long-term steady-state equilibrium advertising strategies and market shares of the brands. We study how customer reaction to their past usage experience of the product (satisfaction) affects the sellers’ advertising strategies and market shares. We further analyze the monopoly market, where the focus is on the question of whether the monopolist should use even-level advertising or pulsing advertising strategy.In the second model, we study the dynamic advertising budget allocation problems, in which the relationship between the advertising expenditure and the product sales is unknown to the retailer and the retailer can only learn this information through observing realized sales. We propose nonparametric advertising budget allocation policies for both single- and multi-product problems. We show that such policies are asymptotically optimal. In particular, for the single-product problem, by constructing a lower-bound instance, we show that our policy achieves near-best asymptotic performance.广告预算的确定和分配是企业运营中一个极为重要的决策。而广告资金的动态支出策略已经被研究了数十年。由于以前可获取的数据往往仅限于市场的一些宏观数据。传统文献主要用一个已知的销售响应函数从宏观层面刻画广告支出和销售量之间的关系。现今，随着互联网，电子商务，社交媒体和数据分析方法的出现，使收集有关消费者行为和实时销售量的数据成为可能。合理地利用这些数据可以大大提高企业的广告效率。这也给广告策略的研究带来了新的契机。本论文研究两个动态广告支出策略模型，一个模型涉及顾客满意度和顾客转换行为，另外一个涉及销售响应函数的动态学习。本文的第一个模型考虑体验商品市场中卖家的广告支出策略。在市场中，顾客没有办法观测到产品的真实质量，他们的产品选择受到自己之前的产品体验和卖家的广告支出的影响。我们首先考虑有竞争的市场，市场中有多个品牌同时进行广告支出决策。我们推导了市场的长期稳态平衡。研究了不同的客户满意度与顾客转换行为的关系对卖家的广告支出策略和市场份额的影响。然后，我们分析了垄断市场中垄断卖家的长期广告支出策略。此外，我们还讨论了该卖家应该使用持续的广告投入策略还是周期性脉冲广告策略的问题。本文的第二个模型研究是的动态广告预算分配问题。我们假设卖家起初并不知道广告支出的销售响应函数，他只能通过观察实时销售数据来对销售响应函数进行学习。我们分别考虑了单产品和多产品的问题，并提出了相应的非参数动态广告预算分配策略。我们证明了所提出的动态预算分配策略是渐进最优的。对于单产品的问题，通过构造出一类“最坏”的响应函数，我们证明了所提出的动态预算分配策略的渐进绩效已基本接近最优。Yang, Chaolin.Thesis Ph.D. Chinese University of Hong Kong 2015.Includes bibliographical references (leaves 133-140).Abstracts also in Chinese.Title from PDF title page (viewed on 12, October, 2016).Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only
Production and inventory management under different supply options
No full textPh.D.In this thesis, we study two dynamic production and inventory management problems under different supply options.In the first work, we study optimal policies for dual-supply inventory systems where a firm commits to buying a total minimum quantity from both supplies or two separate total minimum quantities from each supply over a finite planning horizon. The two supply options differ in their costs and lead times. For the system under the joint commitment, the optimal policy has a simple structure and can be fully characterized by three critical numbers in each period. For the system under the separate commitments, by applying the concept of multimodularity we show that the optimal order quantities in each period are monotonic in the starting inventory and the remaining commitments with bounded sensitivity. Moreover, we establish convergence results on the optimal order quantities when the committed quantity from either supply approaches infinity. These findings highlight the effects of order commitments on the optimal inventory policies. Based on these results, we develop a simple heuristic for the system under separate commitments and show numerically that it performs very well. The numerical study further shows that the firm could incur considerable loss if it ignores or overemphasizes the order commitments when managing its inventory. Finally, we conduct numerical analysis to derive insights into the firm’s supply contract selection in the presence of minimum order commitments.We also show that our results can be partly extended to the lost-sales model, the model with arbitrary fixed lead times, and the model with a hybrid joint and expedited/regular commitments contract. In addition, we study a TMC contract fulfilling problem in which a newsvendor faces the trade-off between more accurate demand information via forecast updating and the increasing shipping cost charged by different shipping options over time. We show the value function in each period is decomposable and a state-independent policy is optimal.In the second work, we study a hybrid manufacturing/remanufacturing dynamic inventory control problem with different lead times over a finite horizon. Employing the concept of multimodularity, we firstly obtain monotonicity of the optimal manufacturing and remanufacturing quantities. In consecutive lead times models, we characterize the optimal policies in each period by two univariate increasing functions: a remanufacture-down to function and a manufacture-up-to function. For models with general lead times, optimal policies solved from an auxiliary multi-echelon inventory system and a dual-sourcing inventory system, are shown asymptotically optimal in the longer manufacturing lead time system and the longer remanufacturing lead time system, respectively, as the inventory of returned products grows. Driven by these asymptotic results, we develop intuitive and simple heuristic policies, numerically test the performance of these heuristics over a wide spectrum of parameters, and illustrate their effectiveness.本論文研究了在三種供應方式下，最優庫存和製造的相關管理問題。這三種供應方式分別是：雙(多)源採購、簽署最小訂貨量長期協議和回收再製造。第二章中我們研究了最小訂貨量長期協議下雙源採購庫存系統中的最優補貨策略。公司承諾在合同期內從兩個供貨源處訂購超過給定的總訂貨 量（即履行聯合契約）或者超過分別給定的訂貨量（即履行獨立契約）。 兩個供貨源的區別為成本和採購提前期。在聯合契約模型中，最優策略具 有簡單形式並被獨立於狀態變量的參數完整刻畫。在獨立契約模型中，每 一期的最優訂貨量關於初始狀態變量單調。並且，當任一供應商承諾的訂 貨量趨於無窮時，我們提出求解最優訂貨量收斂值的方法。根據這些結 論，我們提出了針對獨立契約模型的啟發式算法，並通過數值實驗顯示出 算法的優異性。數值分析顯示在管理庫存中忽略或者過於強調採購合同都 會造成一定損失。最後，我們用數值實驗得到了一些公司如何選擇採購方式的管理啟示。第三章中我們對第二章進行了拓展，研究發現第一章的結論可以部分 延伸至缺貨不補模型，任意固定採購提前期模型，以及混合聯合與獨立契 約模型。此外，我們還研究了一個關於最小訂貨量長期協議履行的報童模 型。其中，報童採用鞅模型（加法及乘法）預測最終需求並通過多種運輸 方式為銷售季囤貨，最小訂貨合同保證了貨源的穩定價格。我們證明出三 維最優方程可分解並且存在獨立於狀態變量的參數來刻畫最優採購策略。第四章中我們考慮有限訂貨期內不同提前期下的混合製造與再製造的動態生產和庫存管理問題。我們首先得到最優製造和再製造量關於狀態變量的單調性。在連續提前期模型中，我們用兩個單一變量增函數刻畫了每一週期內的最優策略。在任意給定提前期模型中，通過解一個多級庫存系 統（和一個雙源採購庫存系統）得到的基準補貨策略對於更長的製造（和 再製造）提前期模型是隨著庫存的增加漸進最優的。基於這些理論結果， 我們進一步提出了簡單有效的啟發式算法。大參數範圍的數值實驗驗證了 這些啟發式算法的優異表現。Wang, Tong.Thesis Ph.D. Chinese University of Hong Kong 2017.Includes bibliographical references (leaves 151-158).Abstracts also in Chinese.Title from PDF title page (viewed on 29, October, 2019)
