Open Access. Powered by Scholars. Published by Universities.®
Operations Research, Systems Engineering and Industrial Engineering Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
-
- Productivity (2)
- Queues (2)
- Stochastic programming (2)
- Transportation (2)
- Agent-Based Computational Economics (1)
-
- Airline check-in counters (1)
- Algorithm (1)
- Alternating Conditional Expectation (1)
- Applications (1)
- Blood collection (1)
- Bucket brigade (1)
- Capacity pooling (1)
- Commodity Trading Advisors (1)
- Computational complexity (1)
- Congestion (1)
- Conic duality (1)
- Data Analytics for Queues (1)
- Demand charge (1)
- Donor management (1)
- Dynamic pricing (1)
- Dynamic programming (1)
- Dynamic server assignment (1)
- Electric vehicle (1)
- Exponential cone programming (1)
- Extreme Price Shocks (1)
- Financial Crisis (1)
- Game theory (1)
- Genetic algorithm (1)
- Humanitarian operations (1)
- Idle time strategies (1)
Articles 1 - 15 of 15
Full-Text Articles in Operations Research, Systems Engineering and Industrial Engineering
Inventory-Responsive Donor-Management Policy: A Tandem Queueing Network Model, Taozeng Zhu, Nicholas Teck Boon Yeo, Sarah Yini Gao, Gar Goei Loke
Inventory-Responsive Donor-Management Policy: A Tandem Queueing Network Model, Taozeng Zhu, Nicholas Teck Boon Yeo, Sarah Yini Gao, Gar Goei Loke
Research Collection Lee Kong Chian School Of Business
Problem definition: In the blood-donor-management problem, the blood bank incentivizes donors to donate, given blood inventory levels. We propose a model to optimize such incentivization schemes under the context of random demand, blood perishability, observation period between donations, and variability in donor arrivals and dropouts. Methodology/results: We propose an optimization model that simultaneously accounts for the dynamics in the blood inventory and the donor’s donation process, as a coupled queueing network. We adopt the Pipeline Queue paradigm, which leads us to a tractable convex reformulation. The coupled setting requires new methodologies to be developed upon the existing Pipeline Queue framework. …
An Exponential Cone Programming Approach For Managing Electric Vehicle Charging, Li Chen, Long He, Yangfang (Helen) Zhou
An Exponential Cone Programming Approach For Managing Electric Vehicle Charging, Li Chen, Long He, Yangfang (Helen) Zhou
Research Collection Lee Kong Chian School Of Business
To support the rapid growth in global electric vehicle adoption, public charging of electric vehicles is crucial. We study the problem of an electric vehicle charging service provider, which faces (1) stochastic arrival of customers with distinctive arrival and departure times, and energy requirements as well as (2) a total electricity cost including demand charges, costs related to the highest per-period electricity used in a finite horizon. We formulate its problem of scheduling vehicle charging to minimize the expected total cost as a stochastic program (SP). As this SP is large-scale, we solve it using exponential cone program (ECP) approximations. …
Stochastic Knapsack Revisited: The Service Level Perspective, Guodong Lyu, Mabel C. Chou, Chung-Piaw Teo, Zhichao Zheng, Yuanguang Zhong
Stochastic Knapsack Revisited: The Service Level Perspective, Guodong Lyu, Mabel C. Chou, Chung-Piaw Teo, Zhichao Zheng, Yuanguang Zhong
Research Collection Lee Kong Chian School Of Business
A key challenge in the resource allocation problem is to find near-optimal policies to serve different customers with random demands/revenues, using a fixed pool of capacity (properly configured). In this paper, we study the properties of three classes of allocation policies-responsive (with perfect hindsight), adaptive (with information updates), and anticipative (with forecast information) policies. These policies differ in how the information on actual demand and revenue of each customer is being revealed and integrated into the allocation decisions. We show that the analysis of these policies can be unified through the notion of "persistency" (or service level) values-the probability that …
Managing Stochastic Bucket Brigades On Discrete Work Stations, Peng Wang, Kai Pan, Zhenzhen Yan, Yun Fong Lim
Managing Stochastic Bucket Brigades On Discrete Work Stations, Peng Wang, Kai Pan, Zhenzhen Yan, Yun Fong Lim
Research Collection Lee Kong Chian School Of Business
Bucket brigades are notably used to coordinate workers in production systems. We study a J-station, I-worker bucket brigade system. The time duration for each worker to serve a job at a station is exponentially distributed with a rate that depends on the station's expected work content and the worker's work speed. Our goal is to maximize the system's productivity or to minimize its inter-completion time variability. We analytically derive the throughput and the coefficient of variation (CV) of the inter-completion time. We study the system under two cases. (i) If the work speeds depend only on the workers, the throughput …
We Are On The Way: Analysis Of On-Demand Ride-Hailing Systems, Guiyun Feng, Guangwen Kong, Zizhuo Wang
We Are On The Way: Analysis Of On-Demand Ride-Hailing Systems, Guiyun Feng, Guangwen Kong, Zizhuo Wang
Research Collection Lee Kong Chian School Of Business
Problem definition: Recently, there has been a rapid rise of on-demand ride-hailing platforms, such as Uber and Didi, which allow passengers with smartphones to submit trip requests and match them to drivers based on their locations and drivers’ availability. This increased demand has raised questions about how such a new matching mechanism will affect the efficiency of the transportation system—in particular, whether it will help reduce passengers’ average waiting time compared with traditional street-hailing systems. Academic/practical relevance: The on-demand ride-hailing problem has gained much academic interest recently. The results we find in the ride-hailing system have a significant …
Multi-Period Lot-Sizing With Supplier Selection: Structural Results, Complexity And Algorithms, Meichun Lin, Woonghee Tim Huh, Guohua Wan
Multi-Period Lot-Sizing With Supplier Selection: Structural Results, Complexity And Algorithms, Meichun Lin, Woonghee Tim Huh, Guohua Wan
Research Collection Lee Kong Chian School Of Business
We consider a multi-period lot-sizing problem with multiple products and multiple suppliers. Demand is deterministic and time-varying. The objective is to determine order quantities to minimize the total cost over a finite planning horizon. This problem is strongly NP-hard. For a special case, we extend the classical zero-inventory-ordering principle and solve it by dynamic programming. Based on this new extension, we also develop a heuristic algorithm for the general problem and computationally show that it works well.
Urban Consolidation Center Or Peer-To-Peer Platform? The Solution To Urban Last-Mile Delivery, Qiyuan Deng, Xin Fang, Yun Fong Lim
Urban Consolidation Center Or Peer-To-Peer Platform? The Solution To Urban Last-Mile Delivery, Qiyuan Deng, Xin Fang, Yun Fong Lim
Research Collection Lee Kong Chian School Of Business
The growing population in cities and booming e-commerce activities create huge demand for urban last-mile delivery, exerting intense pressure on the cities' well-being. To keep congestion and pollution under control, a consolidator can operate an urban consolidation center (UCC) to bundle shipments from multiple carriers before the last-mile delivery. Alternatively, the consolidator can operate a peer-to-peer platform for the carriers to share delivery capacity. We provide guidance for the consolidator to choose between these two business models by comparative analysis. We capture the interactions between the consolidator and carriers using a game-theoretical framework. Under each business model, the consolidator first …
Flexibly Serving A Finite Number Of Heterogeneous Jobs In A Tandem System, Yun Fong Lim, Bingnan Lu, Rowan Wang, Wenjia Zhang
Flexibly Serving A Finite Number Of Heterogeneous Jobs In A Tandem System, Yun Fong Lim, Bingnan Lu, Rowan Wang, Wenjia Zhang
Research Collection Lee Kong Chian School Of Business
Many manufacturing and service systems require a finite number of heterogeneous jobs to be processed by two stations in tandem. Each station serves at most one job at a time and there is a finite buffer between the two stations. We consider two flexible servers that are cross-trained to work at both stations. The duration for a server to finish a job at a station is exponentially distributed with a rate that depends on the server, the station, and the job. Our goal is to identify an efficient policy to dynamically assign the servers to the stations such that the …
Quadratic Two-Stage Stochastic Optimization With Coherent Measures Of Risk, Jie Sun, Li-Zhi Liao, Brian Rodrigues
Quadratic Two-Stage Stochastic Optimization With Coherent Measures Of Risk, Jie Sun, Li-Zhi Liao, Brian Rodrigues
Research Collection Lee Kong Chian School Of Business
A new scheme to cope with two-stage stochastic optimization problems uses a risk measure as the objective function of the recourse action, where the risk measure is defined as the worst-case expected values over a set of constrained distributions. This paper develops an approach to deal with the case where both the first and second stage objective functions are convex linear-quadratic. It is shown that under a standard set of regularity assumptions, this two-stage quadratic stochastic optimization problem with measures of risk is equivalent to a conic optimization problem that can be solved in polynomial time.
Predicting The Performance Of Queues: A Data Analytic Approach, Kum Khiong Yang, Cayirli Tugba, Mei Wan Low
Predicting The Performance Of Queues: A Data Analytic Approach, Kum Khiong Yang, Cayirli Tugba, Mei Wan Low
Research Collection Lee Kong Chian School Of Business
Existing models of multi-server queues with system transience and non-standard assumptions are either too complex or restricted in their assumptions to be used broadly in practice. This paper proposes using data analytics, combining computer simulation to generate the data and an advanced non-linear regression technique called the Alternating Conditional Expectation (ACE) to construct a set of easy-to-use equations to predict the performance of queues with a scheduled start and end time. Our results show that the equations can accurately predict the queue performance as a function of the number of servers, mean arrival load, session length and service time variability. …
Performance Based Contracting For The Manufacturing Industry By Using Integrated Platform And Dynamic Pricing Model, Lindawati, Aldy Gunawan
Performance Based Contracting For The Manufacturing Industry By Using Integrated Platform And Dynamic Pricing Model, Lindawati, Aldy Gunawan
Research Collection Lee Kong Chian School Of Business
Although Performance Based Contracting (PBC) concept is not totally new, the PBC adaptation in Industrial Machinery and Components (IMC) manufacturing, which produces high-value and long life machineries, is rather slow and it is done with extra caution. Three main concerns for manufacturers to implement PBC are the investment cost, the maintenance cost and possible revenue loss. To handle these concerns and accelerate the PBC implementation, we propose an integrated platform that consists of three components: dynamic pricing, sensor data feeding and machinery monitoring. We model the dynamic pricing as an optimization problem and propose Genetic Algorithm to solve the problem. …
Robust Two-Stage Stochastic Linear Programs With Moment Constraints, Sarah Yini Gao, Lingchen Kong, Jie Sun
Robust Two-Stage Stochastic Linear Programs With Moment Constraints, Sarah Yini Gao, Lingchen Kong, Jie Sun
Research Collection Lee Kong Chian School Of Business
We consider the two-stage stochastic linear programming model, in which the recourse function is a worst case expected value over a set of probabilistic distributions. These distributions share the same first- and second-order moments. By using duality of semi-infinite programming and assuming knowledge on extreme points of the dual polyhedron of the constraints, we show that a deterministic equivalence of the two-stage problem is a second-order cone optimization problem. Numerical examples are presented to show non-conservativeness and computational advantage of this approach.
On The Allocation Of Exclusive-Use Counters For Airport Check-In Queues: Static Vs. Dynamic Policies, Mahmut Parlar, Brian Rodrigues, Sharafali Moosa
On The Allocation Of Exclusive-Use Counters For Airport Check-In Queues: Static Vs. Dynamic Policies, Mahmut Parlar, Brian Rodrigues, Sharafali Moosa
Research Collection Lee Kong Chian School Of Business
In this paper we propose a static policy for the optimal allocation of a fixed number of exclusive-use check-in counters dedicated to a single flight. We first provide the motivation for considering the static policy by showing that the dynamic policy already available in the literature suffers from the curse of dimensionality. The objective is to minimize the (expected) total cost of waiting, counter operation, and passenger delay costs which we show to be convex in the number of counters allocated. In those cases where the passenger delay cost is difficult to estimate, we propose an alternative formulation and minimize …
An Analysis Of Extreme Price Shocks And Illiquidity Among Systematic Trend Followers, Bernard Lee, Shih-Fen Cheng, Annie Koh
An Analysis Of Extreme Price Shocks And Illiquidity Among Systematic Trend Followers, Bernard Lee, Shih-Fen Cheng, Annie Koh
Research Collection Lee Kong Chian School Of Business
We construct an agent-based model to study the interplay between extreme price shocks and illiquidity in the presence of systematic traders known as trend followers. The agent-based approach is particularly attractive in modeling commodity markets because the approach allows for the explicit modeling of production, capacities, and storage constraints. Our study begins by using the price stream from a market simulation involving human participants and studies the behavior of various trend-following strategies, assuming initially that their participation will not impact the market. We notice an incremental deterioration in strategy performance as and when strategies deviate further and further from the …
Dynamic Allocation Of Airline Check-In Counters: A Queueing Optimisation Approach, Mahmut Parlar, Sharafali Moosa
Dynamic Allocation Of Airline Check-In Counters: A Queueing Optimisation Approach, Mahmut Parlar, Sharafali Moosa
Research Collection Lee Kong Chian School Of Business
This paper was motivated by an observation in an international airport with regard to allocation of resources for check-in counters. In an exclusive check-in counter system, each flight has a dedicated number of counters that will be open until at least a half-hour before the scheduled departure of that flight. Currently, in many of the airports around the world, the decision to open or close check-in counters is done on an ad hoc basis by human schedulers. In doing so, the schedulers are almost always forced to perform a balancing act in meeting the quality of service stipulated by the …