Xiao Qiang Cai

• Chinese University of Hong Kong

We are concerned about a multi-period portfolio selection problem where the issue of parameter uncertainty for the distribution of risky asset returns should be addressed properly. For analysis, we first propose a novel dynamic portfolio selection model with an \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsf...

Problem definition: We consider a multiportfolio optimization problem in which nonlinear market impact costs result in a strong dependency of one account’s performance on the trading activities of the other accounts. Methodology/results: We develop a novel target-oriented model that jointly optimizes the rebalancing trades and the split of market i...

We study a project management problem where the prime contractor needs to outsource tasks to subcontractors with the required resources. Successful execution of the project requires proper coordination among the subcontractors, as well as contract design by the prime contractor to incentivize the subcontractors. By modeling the subcontractors’ coor...

Travellers are selfish and make routing choices maximizing their own utility, which inevitably leads to congestion and inefficiency in the traffic network. However, travellers’ route choices are affected by the availability and accuracy of travel information. This raises the question: How can the central planner reduce the congestion of the traffic...

Blockchain technology has attracted global attention for its ability to protect data security and traceability. It has driven the development of practical applications in various fields, namely management science, transport and logistics, and supply chain management. Initial coin offerings (ICOs), an emerging start-up fundraising method developed w...

One-way electric carsharing system has become the most widely used form of carsharing service in practice. However, car imbalance, parking shortage, and battery charging jointly impose great challenges upon the operation. Many carsharing operators, e.g., GoFun, offer incentives to flexible users for accepting alternative itineraries and also adopt...

This paper proposes a matching-and-pricing mechanism for a drivers’ demand-reporting problem in parking-sharing programs in which owners share their private parking slots with drivers. We generate a driver-slot matching solution by a centralized assignment procedure according to the demand and supply information reported by drivers and owners, resp...

We consider joint replenishment among multiple retailers subject to various types of carbon constraints. In particular, we consider four types of carbon constraints: carbon tax, strict carbon cap, carbon cap-and-offset, and carbon cap-and-price. Under each carbon policy, we first identify the optimal joint ordering policy. Then, we study the cost a...

We study the problem of collaborative less-than-truckload (LTL) transportation in the form of a shipper consortium, which is operated by a third-party logistics provider (3PL) through a cross-dock/pooling network. The 3PL has responsibility for planning the combined loads prior to actual shipments, hiring and routing carriers to execute shipping, a...

We study the equipment sharing problem where a group of food & beverage companies share the same equipment of a contractor and wish to have their processing tasks coordinated such that the total cost is minimized. The raw materials to be processed are perishable, which incur a decay cost as time goes. One key issue of this equipment sharing problem...

We consider a supply chain consisting of an incumbent national brand manufacturer and a retailer, who wishes to determine the private label encroachment strategy. By investigating the cost{quality trade‐off between lower‐ and higher‐quality private labels, we characterize the retailer's optimal encroachment decisions. Intuitively, the retailer woul...

The existing literature on make-to-order firms typically supposes that the unit production cost is a constant. In contrast, in this study, this cost is a variable that depends on the lead time. Under this assumption, we investigate the pricing problem for both a monopoly firm and two competing firms. Specifically, we develop a queueing-game-theoret...

In this article, we discuss the optimal scheduling problem of the recently introduced model for partial loss due to machine breakdowns, which fills up a significant gap in the existing literature. More specifically, we consider the problem of processing a number of jobs with arbitrary random processing times by a machine subject to general stochast...

We study a problem in which independent project managers cooperate to generate additional revenue by reallocating their resources. This additional revenue equals the increase in the direct return of a project minus the resource transfer cost. For each project, its direct return is closely related to its duration, which is mainly determined by the a...

Shared parking is recognized as a promising solution to tackle the parking space shortage problem in population-dense cities. However, peer-to-peer shared parking by individuals is not easy to implement in such cities, because it requires the consent of the majority of residents and the facilitation of the property management agency. In this paper...

We consider price and inventory decisions in a make-to-stock system from the perspectives of a profit-maximizing server and a social planner in which customers are delay-sensitive. Under two information cases (i.e. an almost unobservable case and a fully observable case), customers decide whether to purchase the product based on their utility. The...

This paper studies a real-time parking-sharing program with which owners of private parking spaces can lend their parking spaces to other drivers to park when these are not in use. Compared with curbside and garage parking problems, the information of supplies and demands is randomly announced by drivers and owners respectively via a parking-sharin...

We study profit allocation rules for joint replenishment among retailers under a carbon cap-and-trade policy. In particular, we consider retailers’ altruistic behavior when designing the profit allocation rules. We show that joint replenishment can increase participants’ total profit and reduce their total amount of carbon emissions. To allocate th...

We consider a problem in which a distributor purchases fresh products from multiple supply sources for subsequent sale at a wholesale market. Due to uncontrollable factors such as traffic congestion or bad weather conditions, the time taken for the product to be delivered from each production origin is uncertain. As the wholesale market is open for...

We investigate a supply contract design problem in an assembly supply chain in which two heterogeneous suppliers produce complementary products and deliver them to the assembler. One supplier is more reliable and exhibits no supply risk, and the other is less reliable and exhibits supply risk. The assembler is better informed about demand and assem...

This paper studies the shippers’ less-than-truckload collaboration in the Physical Internet (PI) for logistics. PI offers a new way to address the efficiency challenges in logistics consolidation through exploiting Internet of Things. The PI facilitates the consolidation of loads from various parties in a much quicker and more efficient way. With t...

The importance of collaborative logistics is getting widely recognized in recent years. However, strategic revealing of private information and disagreements on how savings are split would make any efforts of collaboration unsuccessful. The large-scale nature of real-life transportation networks further complicates the implementation of collaborati...

This paper proposes a general framework of multi-armed bandit (MAB) processes by introducing a type of restrictions on the switches among arms to the arms evolving in continuous time. The Gittins index process is developed for any single arm subject to the restrictions on stopping times and then the optimality of the corresponding Gittins index rul...

We study the problem where independent operators of queueing systems cooperate to generate a win-win solution through capacity transfer among each other. We consider two types of costs: the congestion cost in the queueing system and the capacity transfer cost, and two types of queueing systems: M/M/1 and M/M/s. Service rates are considered to be ca...

While carriers can collaborate to reduce empty traveling miles in truckload shipping, this is difficult to realize because each party is self-interested who may not share his private information that is necessary for the cooperation. In this paper, we propose an iterative auction scheme, which enables carriers to collaborate by exchanging their shi...

We consider a decentralized assembly system in which \(m+n\) unreliable suppliers sell complementary components to an assembler, who faces a random demand. We assume that \(m\) of these suppliers are more powerful than the assembler and sell components via push contracts, while the remaining \(n\) suppliers are less powerful than the assembler and...

This paper considers firms making collaborative production-distribution planning with shipment consolidation to reduce costs. However, the firms have private cost information which they are not willing to disclosure. We develop a computable mechanism based on a decentralized local search heuristic combined with simulated annealing, which allows for...

We consider a decentralized assembly system in which n upstream firms sell complementary components to a downstream firm facing a multiplicative stochastic demand. The downstream firm may make an investment to hold equity in an upstream firm. This not only enables the downstream firm to share the profit of the upstream firm as determined by the equ...

This paper investigates truth-telling mechanisms for individual M/M/1 queueing systems to share their capacity. The cost we consider in this paper is congestion cost incurred by customers in the queueing system, wherein the unit congestion cost of each individual queueing system is private information. We first propose two Grove-Clarke mechanisms (...

We study cost allocation problem arising from less-than-truckload collaboration among perishable product retailers. The relevant costs we consider include fixed transportation cost, variable transportation cost, and decay loss of perishable products. Cooperative game theory is applied to study this cost allocation problem. The corresponding coopera...

This article presents a new credibility estimation of the probability distributions of risks under Bayes settings in a completely nonparametric framework. In contrast to the Ferguson's Bayesian nonparametric method, it does not need to specify a mathematical form of the prior distribution (such as a Dirichlet process). We then show the applications...

We develop a model to formulate the mutual referral process in a health care system involving a city hospital and a community hospital, and derive the optimal mutual referral strategy between them in the subordination situation as a benchmark. We also concentrate on the subcontracting situation, where the city hospital plays a dominating role, offe...

Variation in core condition and uncertainty in market demand pose great challenges for remanufacturers to match supply with demand. This article investigates a firm that acquires and remanufactures cores of multiple quality conditions to satisfy demand. Both remanufacturing-to-stock (RMTS) and remanufacturing-to-order (RMTO) systems are considered....

In recent years, increasing interests have arisen in adding product value through the provision of service. This paper considers the problem in which a demand-enhancing service can be provided by different supply chain parties, resulting in four alternative service channels: (a) manufacturer undertaking service, namely M-channel, (b) retailer under...

This paper addresses a robotic cell rescheduling problem and focuses on trade-off between the total completion time of all jobs and the disturbance of a reschedule. We first define and measure the disturbance of a reschedule as the deviation of completion time of the jobs already scheduled between the reschedule and the initial schedule. To guarant...

We consider dynamic capacity booking problems faced by multiple manufacturers each outsourcing certain operations to a common third-party firm. Each manufacturer, upon observing the current state of the third-party schedule, books capacity with the objective to jointly minimize holding costs that result from early deliveries, tardiness penalties du...

A path finding method in large scene online games was provided. To dynamically load the scene map, the big scene map was divided into many map blocks, map areas were built, which were organized in index table. The evaluation function was set and the heuristic search was used to complete the path finding in one map area or cross map areas. The path...

In this article, we investigate group decision making problems with interval multiplicative preference relations (including complete interval multiplicative preference relations and incomplete interval multiplicative preference relations). On the basis of the number of judgments and the consistency degree of each interval multiplicative preference...

The manufacturer who is a supplier of trade credit may face non-payment risk from customers and a capital shortage problem simultaneously. Trade credit insurance, as one of the most important risk management tools, has been widely used in companies’ daily operation. In this study, the manufacturer who allows customers to delay payment for goods alr...

We study the acquisition and production planning problem for a hybrid manufacturing/remanufacturing system with core acquisition at two (high and low) quality conditions. We model the problem as a stochastic dynamic programming, derive the optimal dynamic acquisition pricing and production policy, and analyze the influences of system parameters on...

Interval-valued intuitionistic preference relation (IV-IPR) is a new type of preference structure used to describe uncertain evaluation information in decision making process. In this paper, we first define the concept of IV-IPR with multiplicative transitivity, and then give a procedure to construct an IV-IPR with multiplicative transitivity from...

This Chapter covers stochastic scheduling problems with irregular performance measures. Section 3.1 is focused on models where both the earliness and tardiness costs are functions of the completion time deviations from the due date. In Section 3.2, we consider the problem where the tardiness cost is a fixed charge once a job is late, whereas the ea...

This chapter provides the foundations for the general theory of stochastic processes and optimal stopping problems. In Section 5.1, we elaborate on the concepts of s-algebras and information, probability spaces, uniform integrability, conditional expectations and essential supremum or infimum at an advanced level of probability theory. Then stochas...

This chapter studies the powerful tool for stochastic scheduling, using theoretically elegant multi-armed bandit processes to maximize expected total discounted rewards. Multi-armed bandit models form a particular type of optimal resource allocation problems, in which a number of machines or processors are to be allocated to serve a set of competin...

This chapter addresses stochastic scheduling problems in which the processing times are varying during processing jobs. Two types of models, involving deteriorating processing times and learning effects respectively, are introduced and their solutions are studied. Section 9.1 deals with the model with deteriorating processing times. We formulate th...

This chapter is devoted to optimal dynamic policies. Section 7.1 discusses differences between optimal static and dynamic policies with emphasis on the impacts of different levels of information utilization. Section 7.2 treats optimal policies in the class of restricted dynamic policies for problems subject to random machine breakdowns under the to...

This chapter introduces and summarizes basic concepts and terminology in probability theory and stochastic scheduling, which build the foundation to develop optimal policies for a wide range of scheduling problems in subsequent chapters. In Section 1.1, we summarize the fundamental theory of probability in a compact and concise way. Section 1.2 dis...

This chapter discusses some other scheduling problems and models that do not fall into the categories presented in Chapters 2–9. Section 10.1 considers the problem to minimize a random variable of performance measure under stochastic order, which produces stronger results than the common approach of minimizing the expected value of the measure. Sec...

The majority of machine scheduling problems studied in the literature assume that the machine used to process the jobs is continuously available until all jobs are completed. In reality, however, it is a common phenomenon that a machine may break down randomly from time to time. This chapter covers scheduling problems where the machines are subject...

This chapter covers stochastic scheduling problems with regular performance measures. Section 2.1 is focused on models of minimizing the sum of expected completion time costs. In Section 2.2, we consider the problem of minimizing the expected makespan (the maximum completion time). Some basic models with due-date related objective functions are add...

This chapter treats a class of scheduling models subject to machine breakdowns with incomplete information. Under this class of models, the repeated processing times between breakdowns are dependent via a latent random variable. This leads to partially available information on the processing times during the process, and the information is graduall...

Remanufacturing is creating considerable benefit to industry and community, but the uncertainties in both supply and demand sides bring significant difficulty to the production and marketing management of remanufactured products. This paper considers the remanufacturing and pricing decisions when both the remanufacturing yield and the demand for re...

A version of the dynamic lot-sizing (DLS) problem involving durable products with end-of-use constraints is analyzed in this paper. First, we mathematically formulate this problem, then certain properties are derived to construct the structure of the optimal solution. Next, based on these properties, a recursive optimization algorithm is proposed f...

A gesture recognition method based on wireless data glove was provided, and this method could be used in large scenes convenient interactive exhibition application, theme pavilion application, entertainment, etc. CC2530 chip was selected as the main chip of the wireless data glove, four fingers buttons on the wireless data glove were set up, Xsens...

Uncertainty is a common phenomenon in our real world. Interval utility values and interval preference orderings are two of the simplest and most convenient tools to describe uncertain preferences in decision making. In this paper, we investigate consensus problems in group decision making with interval utility values and interval preference orderin...

We consider a problem where a firm produces a variety of fresh products to supply two markets: an export market and a local market. A public transportation service is utilized to deliver the products to the export market, which is cheap, but its schedule is often disrupted severely. Each time this happens, the firm faces the following questions. (i...

We consider a supply chain in which a producer supplies a fresh product, through a third-party logistics (3PL) provider, to a distant market where a distributor purchases and sells it to end customers. The product is perishable, both the quantity and quality of which may deteriorate during the process of transportation. The market demand is random,...

We consider a collaborative logistics problem where a group of shippers in a logistics network, each facing a time-varying deterministic demand, collaboratively make the production schedules together in order to reduce transportation cost by shipment consolidation; a common third-party logistics provider (3PL) is hired by them to carry the shipment...

We consider the problem where a group of manufacturers outsource non-preemptive operations to a third-party, where non-preemptive operations means processing operations can not be interrupted when it starts, such as mould making, blast furnace iron making. The manufacturers book time windows announced by third-party with prices and schedule operati...

Trade credit insurance, as one of the most important risk management tools, has been widely used in companies' general operation. In this paper, we study a supply chain with a manufacturer and downstream partners (buyers). The manufacturer who allows its downstream partners to delay payment for goods already delivered, purchases trade credit insura...

This paper explores a generalized supply chain model subject to supply uncertainty after the supplier chooses the production input level. Decentralized systems under wholesale price contracts are investigated, with double marginalization effects shown to lead to supply insufficiencies, in the cases of both deterministic and random demands. We then...

This paper addresses a rescheduling problem in a robotic cell where a material handling robot is responsible to transport parts from one workstation to another and the different jobs (parts) arrive at the cell randomly. Our objective is to minimize the total completion time of all the jobs by dynamically changing the current schedule. Following a r...

We study the optimal selling price of a deteriorating product under a deterministic situation in a finite time horizon where the time horizon is either known or unknown. Inventory holding cost is expressed as a quadratic function of the current inventory level. Given a known time horizon, we develop a model by considering the deterioration dynamics...

Group-buying price is a new pricing mechanism originated from Internet bidding. It has been proved that, with this pricing mechanism, buyers’ cooperation in a B2C environment is beneficial for both the seller and buyers. The contribution of this paper is two-fold. First, we formally prove that, when buyers’ valuation on the product is transparent a...

The online real-time visualization system of aluminum production was designed and implemented to show the complex aluminum production process and monitor the complex aluminum production data. Firstly, the framework of the visualization system was explored, and the system is mainly divided into several important modules, including loading resource m...

Steering wheel interactive method based on steering resisting moment mainly focuses on improving the flexibility and stability of interactive virtual driving simulator. After turning the steering wheel, the hardware driver on the steering wheel acquired the angle signal real-time and transmitted the angle signal to driving simulator. Then, accordin...

In this paper, we develop models to determine operational and financial decisions of a supply chain under the condition that the retailer faces a financial constraint and the manufacturer can offer trade credit to assist the retailer. We first study the case where the retailer is risk-neutral, and derive the optimal ordering and financial decisions...

We consider an outsourcing problem where a group of manufacturers outsource jobs to a single third party who owns a specialized facility needed to process these jobs. The third party announces the time slots available on her facility, and the associated prices. Manufacturers reserve, on a first-come-first-book basis, time slots that they desire to...

Keren [The single-period inventory problem: extension to random yield from the perspective of the supply chain. Omega 2009;37:801–10] considers a supply chain in which the distributor faces a known demand and orders from the producer subject to a random production yield, and shows that the distributor may find it optimal to order more than what i...

In this paper, we develop models to determine operational and financial decisions of the supply chain under the assumption that the retailer faces budget constraint and the manufacturer offers trade credit to help him. We first assume that the retailer is risk neutral, and derive his optimal ordering and financial decisions. Then, we study the down...

We consider a supply chain in which a distributor procures from a manufacturer a type of fresh product, which has to undergo long distance transportation before reaching the market. In addition to the risk caused by random fluctuations of the market demand, the distributor also faces the risk that the product procured may decay and deteriorate duri...

Consider a supply chain where the retailer faces a stochastic demand and orders from the supplier, while the supplier manufactures new products and also remanufactures early returns to meet the order. The order and manufacturing quantity decisions are studied under three decentralised cases: (1) the Stackelberg case, where the manufacturing quantit...

"Intuitionistic Fuzzy Information Aggregation: Theory and Applications" is the first book to provide a thorough and systematic introduction to intuitionistic fuzzy aggregation methods, the correlation, distance and similarity measures of intuitionistic fuzzy sets and various decision-making models and approaches based on the above-mentioned informa...

We study optimal pricing and order policies in supply chain management of fashion products (e.g., a fashion apparel category) with consideration of product returns between supply chain partners (B2B). In order to study channel performance and optimal policies, two stochastic models for centralized channel and decentralized channel are, respectively...

Correlation, distance and similarity measures are an important research topic in the IFS theory, which has received great attention in recent years. In this chapter, we shall give a thorough and systematic introduction to the existing research results on this topic.

In real-life situations, such as partner selection in supply chain management, and performance assessment of military systems, a decision maker may be unable to express accurately his/her preferences for alternatives, because ① the decision maker may not possess a precise or sufficient level of knowledge (i.e., lack of knowledge to a certain degree...

We consider an inventory and production planning problem with uncertain demand and returns, in which the product return process is integrated into the manufacturing process over a finite planning horizon. We first propose an inventory control model for the return and remanufacturing processes with consideration of the uncertainty of the demand and...

This paper focuses on the problem of how to determine expert weights in multiple attribute group decision making. We first aggregate all the individual decision matrices into the collective decision matrix by means of the weighted arithmetic averaging operator, and then from the angle of minimizing group discordance, we establish a general nonlinea...

We present a general solution framework for the price-setting newsvendor problem with a multiplicative stochastic demand. Under mild assumptions, such as increasing price elasticity on the mean demand function and increasing generalized failure rate on the distribution of the random factor, we first prove that both the profit function with respect...

Preference relations as simple and efficient information description tools have been widely used in practical decision-making problems. Intuitionistic preference relation, which is often met in real problems, is usually utilized to provide the experts' vague or fuzzy opinions over objects under uncertain circumstances. Owing to the limitations of t...

We consider the economic lot-sizing (ELS) game with perishable inventory. In this cooperative game, a number of retailers that have a known demand through a fixed number of periods for a same kind of perishable goods collaborate to place joint orders to a single supplier. We first show that an ELS game with perishable inventory is subadditive, tota...

We investigate the problem of scheduling a set of jobs to minimize the expected makespan or the variance of the makespan. The jobs are subject to deteriorations which are expressed as linear increments of the processing requirements. The machine is subject to preemptive-resume breakdowns with exponentially distributed uptimes and downtimes. It has...

This paper considers a supplementary supply–order system in a multi-period situation. In each period, the buyer first places an initial order based on the demand prediction; he has the opportunity to place a supplementary order with the supplier after the demand of that period is realized. The supplier maintains an inventory, and decides the quanti...

In this correspondence paper, we consider a large group decision-making problem in which the decision makers provide their preferences over a number of alternatives using distinct preference structures, including the following: 1) utility values; 2) preference orderings; 3) multiplicative preference relations; 4) incomplete multiplicative preferenc...

In many group decision-making situations, decision makers’ preferences for alternatives are expressed in preference relations (including fuzzy preference relations and multiplicative preference relations). An important step in the process of aggregating preference relations, is to determine the importance weight of each preference relation. In this...

We study a production planning problem in which a manufacturer aims to meet a random market demand by manufacturing new product and remanufacturing returned product. The product returns are random and price-sensitive. To maximise his profit, the manufacturer needs to optimally decide on the acquisition price for the returned product as well as the...

Aggregation of intuitionistic fuzzy information is a new branch of intuitionistic fuzzy set theory, which has attracted significant interest from researchers in recent years. In this paper, we provide a survey of the aggregation techniques of intuitionistic fuzzy information, and their applications in various fields, such as decision making, cluste...

Environmental legislation and customer expectations increasingly force manufacturers to take recovery of used products into account in their production and inventory management. One of the areas concerned is production planning with returned products remanufacturing. In this paper, we discuss the optimal decision for a joint manufacturing and reman...

Intuitionistic fuzzy numbers are very useful for experts to depict in depth their fuzzy preference information over objects. In this work, we investigate multiple attribute group decision-making problems in which the attribute values provided by experts are expressed in intuitionistic fuzzy numbers, each of which is composed of a membership degree,...

In this paper we develop a supply chain model consisting of a supplier and a manufacturer. The manufacturer faces a stochastic and price-sensitive demand, orders a component from the supplier to manufacture new products, and also remanufactures the product returns with a stochastic quantity. The supplier chooses the wholesale price of the component...

In this paper, we investigate a manpower planning problem with single employee type over a long planning horizon. The dynamic demand for manpower must be fulfilled by allocating enough number of employees and each employee has a minimal employment period. A cost objective is concerned where the costs for every employee include salary, recruitment a...