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Publications (42)
Early risk diagnosis and driving anomaly detection from vehicle stream are of great benefits in a range of advanced solutions towards Smart Road and crash prevention, although there are intrinsic challenges, especially lack of ground truth, definition of multiple risk exposures. This study proposes a domain-specific automatic clustering (termed Aut...
Early risk diagnosis and driving anomaly detection from vehicle stream are of great benefits in a range of advanced solutions towards Smart Road and crash prevention, although there are intrinsic challenges, especially lack of ground truth, definition of multiple risk exposures. This study proposes a domain-specific automatic clustering (termed Aut...
This paper studies dynamic channel control and pricing of a single perishable product distributed through multiple channels with the objective of maximizing the total expected profit over a finite horizon. We consider two types of commissions, namely proportional and fixed commissions, on the third-party channels and utilize stylized linear functio...
To address the discrepancy between dynamic models and industrial practice in airline revenue management, we propose a hybrid model for the multi-leg problem that integrates static and dynamic models. We formulate the problem using a stochastic dynamic program and characterize the optimal booking policy as a switching-curve (surface) type.
Nonlinear pricing is frequently used by fast-fashion retailers (e.g., Zara). Discounts of the form “Buy 2, get 20% off” or “Buy 3 and save 30%” are becoming common. As revealed in a recent study by Gallego et al. (2019), nonlinear dynamic pricing can significantly improve a company’s revenue, by as much as 30%–90%, especially when inventories are h...
This study designs a framework of feature extraction and selection, to assess vehicle driving and predict risk levels. The framework integrates learning-based feature selection, unsupervised risk rating, and imbalanced data resampling. For each vehicle, about 1300 driving behaviour features are extracted from trajectory data, which produce in-depth...
In this paper, we investigate unbundling when a firm dynamically prices a basic service, while separating the sale of a fixed‐price add‐on. We characterize the optimal dynamic unbundling pricing policy and investigate its structural properties. We find that the value function with unbundling increases in the degree of dependence between consumers’...
Consumers may overestimate the precisions of their valuation predictions. In this paper, we propose a decision model of this overconfidence in valuation and analyze a retailer's advance selling strategy in a two-period setting. The presence of overconfident consumers yields new insights in the retailer's selling strategy. We find that advance selli...
We provide a unified framework to study monotone optimal control for a class of Markov decision processes through D-multimodularity. We demonstrate that each system in this class can be classified as either a substitution-type or a complement-type system according to the possible transition set, which can be used as a classification mechanism that...
In their paper, “On the Cross-sectional Relation between Expected Returns and Betas”, Roll and Ross (1994) demon- strated that the expected returns and betas can have zero relationship even when the underlying market portfolio proxies are nearby the efficient frontier. In this note, we provide the mathematical details that lead to their conclusion...
Based on a household survey, this study investigates the income effect of car
ownership decisions and studies key variables that influence working trip decision in the
Singapore context. A binary logit model reveals that the income elasticity for car ownership
is 0.5944, meaning that car owners tend to treat cars as necessity for commuting purposes...
This paper introduces the multimodularity concept to study structural properties for certain class of stochastic dynamic control problems through a new efficient approach. We demonstrate that this approach can substantially simplify the proofs of the main results of one recent article and provide an alternative method for two other models in the li...
We examine a revenue management problem with random demands from an advance market and a spot market when the revenue manager is risk averse with an atemporal utility function. This article investigates the impact of the degree of risk aversion and the level of demand uncertainty on the manager's optimal capacity allocation. We first show that the...
In this paper, we study a two-flight model where there are two flights between two cities in a day (e.g., one departs at 9:00Â am and another at 11:00Â am) and booking requests in each fare class arrive according to a random process. There are three types of booking requests: the first and second types are respectively for the first and the second...
We show that the monotone structures of dynamic pricing for a single perishable product under risk-neutrality are preserved under risk-sensitivity with the additive general utility and atemporal exponential utility functions. We also show that the optimal price is decreasing over the degree of risk-sensitivity under the exponential class of both ad...
Three stability theorems due to Gnedenko (1943), Barndorff-Nielsen (1963), and Tomkins (1986) are extended to the sample maxima of identically distributed ϕ-mixing and m-dependent sequences.Trois théorèmes de stabilité dus à Gnedenko (1943), Barndorff-Nielsen (1963) et Tomkins (1986) sont généralisés à la suite des maxima dérivés d'une suite ϕ-mela...
This paper examines the classical seat allocation problem under competition between two airlines with different cost structure. The cost asymmetry that has been ignored in the yield management literature can be caused by either operations or distributions. We investigate the decision problem of two airlines offering two identical fare classes under...
By introducing the concept of speed elasticity of flow and density, this paper provides a generic characterization for a class of well-behaved equilibrium speed-flow curves that are differentiable and backward bending and possess monotone speed-density curves. We start with a comprehensive review on classical models, including Greenberg, Greenshiel...
We examine a seat allocation game between two airlines for flights with two fares with dependent random demands. The strategic variable of this game is each airline's booking limit for the low fare. We have shown that there exists an equilibrium booking strategy such that both airlines will protect the same number of seats for the full fare and the...
The existing literature in revenue management does not explicitly solve the ‘pricing problem’ per se in the sense that the fare structure is a solution from the model. In fact, fare prices must be pre-set and the demand forecasting each fare class, which is critical to revenue management models, is contingent on the fare price. It is also found tha...
The aim of this paper is to investigate the validity of the optimality results derived from [Eur. J. Oper. Res. 134 (2001) 631] by relaxing the following two assumptions: (a) the firm offers restricted units first and then unrestricted units later at higher price levels, and (b) only one type of product is available during the whole selling process...
This article studies the performance of the global airline industry by applying Tobin’s q, a financial market-based measure of firm value, as the primary measure. With 27 airlines from Asia Pacific, Europe, and North America over the period of 1989 to 1999 we find that the industry on average is a low q ratio industry, and European carriers general...
The paper discusses the stability of suitably-defined maxima of a set of i.i.d. random variables with multidimensional indices.It is shown that theorems of Gnedenko (1943) and Tomkins (1986) concerning relative stability and complete relative stability of maxima remain valid in the new setting.Moreover, a criterion for almost sure relative stabilit...
In this note, we attempt to prove the equivalence of the optimality conditions from three well-known existing models that deal with the seat allocation problem for a single leg, multifare flight with independent fare class demands.
The paper aims to address the practical relevance of each of three empirical elements, namely, the speed–flow relationship, the demand function and the generalized cost that affect the implementation of a congestion pricing system. We first derive the theoretical congestion toll estimate for a class of speed–flow relationship known as the generaliz...
The aim of this paper is to address the pricing problem of non-storable perishable goods or services, such as airline seats and hotel rooms, by incorporating the use of purchase restrictions, such as the advance booking requirement that is commonly used by airlines and hotels. We will show that there exists an optimal pricing policy of at most thre...
This paper seeks to uncover key differences between lasting and discontinued airline alliances by applying factor analysis. Several meaningful patterns emerge. First, alliances aiming at customer loyalty and operations integration are more likely to be long lasting. Second, bilateral code-sharing with serious financial tie-up through pooling agreem...
Most research on airline passenger spill has assumed a normal distribution for the nominal demand. But empirical evidences show that normal distribution is not suitable in many cases, especially for spill analysis of business and first class compartments. In this paper, we derive formulae for calculating the expected number of spilled passengers wh...
There are many studies on the Area Licensing Scheme in Singapore. One of the debatable issues is whether or not the congestion toll of $3 is too high. The main objective of this paper is to develop a simple method for estimating the congestion toll by directly using the commonly available traffic count data. In our sensitivity analysis, we use thre...
Despite the current economic turmoil affecting much of the region, air traffic volumes in Asia Pacific, and in the ASEAN region in particular, will continue to grow over the coming decade. In this article, we will briefly review recent initiatives among the transport ministers from ASEAN countries. Future challenges for ASEAN aviation, especially i...
Fix an integerr=1. For eachn=r, letMnr be the rth largest ofX1,...,Xn, where {Xn,n=1} is a sequence of i.i.d. random variables. Necessary and sufficient conditions are given for the convergence of ?n=r8naP[|Mnr/an-1|0, where {an} is a real sequence and a=-1. Moreover, it is shown that if this series converges for somer=1 and some a>-1, then it conv...
By introducing the speed-elasticity of flow, this paper provides a generic characterization for equilibrium speed-flow curves that satisfy the fundamental identity of the traffic flow. With this new characterization, we have integrated several well-known speed-flow models, including the classic Greenshield-type and Underwood-type models, and the mo...
This paper studies the optimal pricing problem for firms using two types of restrictions. Linear programming techniques will be used to derive the optimal pricing policies under three different scenarios, namely the nested restrictions, mutually exclusive restrictions and the general case. For the first two scenarios, there exists an optimal pricin...
