Vincent F. Yu

National Taiwan University of Science and Technology · Department of Industrial Management

This paper presents an extension of the Electric Vehicle Routing Problem with Time Windows and Partial Recharges (EVRPTW-PR), which incorporates the use of parcel lockers as a delivery method (i.e., self-pickup method). This variant, named the electric vehicle routing problem with time windows, partial recharges, and parcel lockers (EVRPTW-PR-PL),...

This research addresses the Vehicle Routing Problem with Simultaneous Pickup and Delivery and Occasional Drivers (VRPSPDOD), which is inspired from the importance of addressing product returns and the emerging notion of involving available crowds to perform pickup and delivery activities in exchange for some compensation. At the depot, a set of reg...

Plastic waste from fast-moving consumer goods packaging has become a global concern. One solution is home-refill delivery service (HRDS) that offer the distribution of consumable products, including to environmentally conscious customers. This research thus employs an extended Technology Acceptance Model (TAM) with environmental concerns, green per...

A substantial distribution system is achievable to attain through the simultaneous design of the location facility and route generation. This problem is generally called a location routing problem (LRP), where both strategic decision and operational decisions are considered during the decision initial phase. Nevertheless, for some real applications...

Referring to the widespread problem of diploma forgery in Indonesian educational institutions as the impetus for UNTIRTA’s latest vision as an “Integrated, Smart, and Green University,” UNTIRTA intends to use blockchain technology to prevent diploma forgery and overcome issues related to existing platforms at UNTIRTA, such as frequent connection in...

This research introduces a new variant of the two-echelon vehicle routing problem (2EVRP) called the two-echelon vehicle routing problem with transshipment nodes and occasional drivers (2EVRP-TN-OD). In addition to city freighters in the second-echelon network, a set of occasional drivers (ODs) is available to serve customers. ODs are the basis of...

The main problem of spare parts management is to maintain the minimal requirement of stock keeping units kept. This research proposes a joint optimization model of multi-item multi-period spare parts inventory management and planned maintenance under uncertain failures in order to balance inventory cost and spare parts availability. This paper pres...

This research introduces the multi-depot general share-a-ride problem (MD-GSARP), which is an extension of the general share-a-ride problem (G-SARP). The goal of MD-GSARP is to maximize the profit from serving parcel and passenger requests with taxis that depart from several depots and return to their respective depots. We developed a mixed integer...

Cross-dockingis a useful concept used by many companies to control the product flow. It enables the transshipment process of products from suppliers to customers. This research thus extends the benefit of cross-docking with reverse logistics, since return process management has become an important field in various businesses. The vehicle routing pr...

The purpose of this research is to provide a complete method for measuring the performance of green supply chain management (GSCM) in the steel manufacturing sector using a combined approach. This study is conducted on an integrated system based on four things: the design of the GSCM performance measurement model based on the Seven Sink Performance...

This research studies a transportation problem to minimize total transportation cost under the rough interval approximation by considering the multi-modal transport framework, referred to here as the rough Multi-Modal Transportation Problem ( MMTP ). The parameters of MMTP are rough intervals, because the problem is chosen from a real-life scenario...

Aggregate production planning (APP) was developed for solving the problem of determining production, inventory, and workforce levels to meet fluctuating demand requirements over a planning horizon. In this work, multiple objectives were considered to determine the most effective means of satisfying forecasted demand by adjusting production rates, h...

In robot-assisted manufacturing or assembly, following a predefined path became a critical aspect. In general, inverse kinematics offers the solution to control the movement of manipulator while following the trajectory. The main problem with the inverse kinematics approach is that inverse kinematics are computationally complex. For a redundant man...

Multimodal transport refers to the transportation of goods under a single contract but performed with at least two different modes of transport. This research designs a new method for solving the Transportation Problem (TP) by introducing multimodal transport systems under fuzzy-stochastic environment, which we refer to as Fuzzy-Stochastic Multimod...

Municipal waste management has become a challenging issue with the rise in urban populations and changes in people’s habits, particularly in developing countries. Moreover, government policy plays an important role associated with municipal waste management. Thus, this research proposes the regional location routing problem (RLRP) model and multi-d...

The intermittent nature of renewable sources, uncertain demand load, and the location of microgrids cause challenges for the proper energy balance between supply and demand. To overcome the issues caused by such challenges and to be economically efficient while minimizing environmental impacts, microgrid design with renewable energy sources has rec...

For optimal equipment procurement in Taiwan, first, the specifications and prices of a product are evaluated. Based on these evaluations, procurement decisions are made. Ensuring accurate evaluation criteria for procurement is a multicriteria decision making (MCDM) problem. Printed circuit board (PCB) manufacturers have not grasped the decision-mak...

Construction contractors significantly contribute to the progress and success of projects. Contractor prequalification grants tendering rights only to competent contractors. The bidding process is one of the most critical phases in the construction industry. The project leader must assess the general, technical, and financial information of the con...

Customers’ expectations of timely and accurate delivery and pickup of online purchases pose a new challenge to last-mile delivery. When the goods sent to customers are not received, they must be returned to the warehouse. This situation provides a high additional cost. Parcel locker systems and convenience stores have been launched to solve this pr...

This research introduces a new variant of the vehicle routing problem in the last-mile delivery process - namely, the Crowd-Shipping Problem with Time Windows, Transshipment Nodes, and Delivery Options (CSPTW-TN-DO). Two types of fleets (i.e., dedicated vehicles and occasional drivers) are available to serve three types of customers. Type 1 custome...

Due to the growth in e-commerce, city logistics needs to cope with the rise of customers’ demand. Consequently, it adds to the complexity of the last-mile delivery process. Moreover, this process often contributes significantly to the distribution cost of companies. An alternative to alleviate the problem is the utilization of parcel lockers. It al...

An efficient maintenance schedule for gas turbines of power plants ensures a reliable electricity supply. This study addresses a generator maintenance scheduling problem arising from Taiwan’s combined cycle power plant with two notable characteristics, i.e., a specific sequence of various maintenance types and the concept of performing maintenance...

This research introduces an extension of the Orienteering Problem (OP), known as Set Team Orienteering Problem with Time Windows (STOPTW), in which customers are first grouped into clusters. Each cluster is associated with a profit that will be collected if at least one customer within the cluster is visited. The objective is to find the best route...

Supplier training to develop and improve supplier capabilities to meet the needs of the Original Equipment Manufacturers (OEMs) is necessary for supply chain efficiency and effectiveness. In the absence of any comprehensive model for supplier training need assessment and measurement, in this paper, we first propose a supplier training model and the...

New labor laws that include additional legal requirements or amendments occasionally come into effect, and these new laws may also bring about challenges to common hospital operations such as outpatient nurse scheduling. This research thus examines changes in Taiwan's new labor law that might affect this scheduling problem. A binary goal programmin...

This research addresses a new variant of the vehicle routing problem, called the two-echelon vehicle routing problem with time windows, covering options, and occasional drivers (2E-VRPTW-CO-OD). In this problem, two types of fleets are available to serve customers, city freighters and occasional drivers (ODs), while two delivery options are availab...

Employing maintenance threshold plays a critical step in determining an optimal maintenance policy for an offshore wind system to reduce maintenance costs while increasing system reliability. Considering the limited works on this topic, we propose a two-stage procedure to determine the optimal maintenance thresholds for multiple components of an of...

The Share-a-Ride Problem with Flexible Compartments (SARPFC) is an extension of the Share-a-Ride Problem (SARP) where both passenger and freight transport are serviced by a single taxi network. The aim of SARPFC is to increase profit by introducing flexible compartments into the SARP model. SARPFC allows taxis to adjust their compartment size withi...

This research presents a variant of the vehicle routing problem known as the path cover problem with time windows (PCPTW), in which each vehicle starts with a particular customer and finishes its route at another customer. The vehicles serve each customer within the customer’s time windows. PCPTW is motivated by a practical strategy for companies t...

[This corrects the article DOI: 10.1371/journal.pone.0245187.].

This paper presents a new variant of the Multi-Vehicle Cyclic Inventory Routing Problem (MV-CIRP) which aims to determine a subset of customers to be visited, the appropriate number of vehicles used, and the corresponding cycle time and route sequence, such that the total cost (e.g. transportation, inventory, and rewards) is minimized. The MV-CIRP...

This research mainly focuses on presenting an innovative study of a multi-stage multi-objective fixed-charge solid transportation problem (MMFSTP) with a green supply chain network system under an intuitionistic fuzzy environment. The most controversial issue in recent years is that greenhouse gas emissions such as carbon dioxide, methane, etc. ind...

This study addresses a variant of the Electric Vehicle Routing Problem with Mixed Fleet, named as the Green Mixed Fleet Vehicle Routing Problem with Realistic Energy Consumption and Partial Recharges. This problem contains three important characteristics – realistic energy consumption, partial recharging policy, and carbon emissions. An adaptive La...

This paper studies the integration of the Vehicle Routing Problem with Cross-Docking (VRPCD). The aim is to find a set of routes to deliver products from a set of suppliers to a set of customers through a cross-dock facility, such that the operational and transportation costs are minimized, without violating the vehicle capacity and time horizon co...

Supplier selection and segmentation are crucial tasks of companies in order to reduce costs and increase the competitiveness of their goods. To handle uncertainty and dynamicity in the supplier segmentation problem, this research thus proposes a new dynamic generalized fuzzy multi-criteria group decision making (MCGDM) approach from the aspects of...

This paper introduces the heterogeneous fleet vehicle routing problem with multiple cross-docks, a variant of the vehicle routing problem with cross-docking, which considers the use of multiple cross-docks and a heterogeneous fleet of vehicles in a distribution system. A mixed integer linear program and an adaptive neighborhood simulated annealing...

This research discusses the sequence of inbound and outbound aircrafts on a mixed operation single runway at an airport. Influenced by the climate, the target airport cannot meet landing conditions. As a result, aircrafts have to land at other nearby airports. Since the sequence for considering both normal and alternate aircrafts arriving in a fixe...

This study, by considering the time-dependent demand (TDD) characteristic, investigates the location-routing problem with time-dependent demands (LRPTDD) as an extension of the location-routing problem (LRP). The demand in each customer site is represented by a constant demand rate over a known production period. In the LRPTDD, the locations are se...

This research examines the problem of designing a two-echelon freight distribution system in a dense urban area that considers third-party logistics (TPL) and loading–unloading zones (LUZs). The proposed system takes advantage of outsourcing the last mile deliveries to a TPL provider and utilizing LUZs as temporary intermediate facilities instead o...

Cross-docking is a logistics strategy that aims at less transportation costs and fast customer deliveries. Incorporating an efficient vehicle routing could increase the benefits of the cross-docking. In this paper, the vehicle routing problem with reverse cross-docking (VRP-RCD) is studied. Reverse logistics has attracted more attention due to its...

This paper studies the integration of the vehicle routing problem with cross-docking, namely VRPCD. The aim is to find a set of routes to deliver single products from a set of suppliers to a set of customers through a cross-dock facility, such that the operational and transportation costs are minimized, without violating the vehicle capacity and ti...

Symbiotic organisms search (SOS) is a promising metaheuristic algorithm that has been studied recently by numerous researchers due to its capability to solve various hard and complex optimization problems. SOS is a powerful optimization technique that mimics the simulation of the typical symbiotic interactions among organisms in an ecosystem. This...

The shelf space allocation problem (SSAP) aims to determine the optimal mix of product displays to maximize profitability. Decisions on the right product at the right location with the right space allocation are necessary when shelf space is limited. We adapt a comprehensive SSA model that considers own-space and cross-space elasticities, and condu...

This paper introduces the path cover problem (PCP) that is a variant of the capacitated vehicle routing problem (CVRP). In contrast to CVRP, a vehicle route in PCP involves a set of vertex-disjoint paths where a vehicle starts at a customer and finishes at another customer without traveling to the depot. PCP is defined to find a set of service path...

This research proposes a new variant of the location-routing problem (LRP) called LRP with Demand Range (LRPDR) by allowing flexibility in the delivery quantity. The goal of the LRPDR is to minimize the objective value calculated by the total cost minus the extra revenue. The total cost consists of the travelling cost of vehicles, the opening cost...

This paper introduces the Team Orienteering Problem with Time Windows and Partial Scores (TOPTW-PS), which is an extension of the Team Orienteering Problem with Time Windows (TOPTW). In the context of the TOPTW-PS, each node is associated with a set of scores with respect to a set of attributes. The objective of TOPTW-PS is to find a set of routes...

This paper studies the Single-Vehicle Cyclic Inventory Routing Problem (SV-CIRP) with the objective of simultaneously minimizing distribution and inventory costs for the customers and maximizing the collected rewards. A subset of customers is selected for the vehicle, including the quantity to be delivered to them. Simulated Annealing (SA) is propo...

This research studies the capacitated green vehicle routing problem (CGVRP), which is an extension of the green vehicle routing problem (GVRP), characterized by the purpose of harmonizing environmental and economic costs by implementing effective routes to meet any environmental concerns while fulfilling customer demand. We formulate the mathematic...

Public consciousness on environmental sustainability and industry impact on environment has been increasing for the last few decades. As a result, more and more companies are taking pollution factor into account when planning their logistic activities. Pollution Routing Problem (PRP) is an extension of the classical Vehicle Routing Problem with Tim...

This paper considers a multi-objective fixed-charge transportation problem (MOFCTP) in which the parameters of the objective functions are random rough variables, while the supply and the demand parameters are rough variables. In real-life situations, the parameters of a multi-objective fixed-charge transportation problem may not be defined precise...

This study investigates the team orienteering problem with time windows and time-dependent scores (TOPTW-TDS), which is a new variant of the well-known team orienteering problem with time windows (TOPTW). TOPTW-TDS builds a set of paths to maximize the collected scores. The score of visiting an attraction is different depending on the time of visit...

Due to recent supply disruptions, there has been a rapid increase in panic buying. This study considers a wholesaler selling two brands of a product with multiple weights and produced by different manufacturers to multiple retailers. The products are substituted based on weight (same brand) and a competitor's brand over two periods. In the first pe...

The Bass model offers several successful applications in forecasting the diffusion process of new products. Due to its potential and flexibilities, the application of this model is not only limited now to forecasting, but also extends to other fields such as analyzing a supply chain's responses, optimizing production plans, and so forth. This study...

This study formulates a mixed integer nonlinear programming (MINLP) model for the shelf space allocation problem (SSAP) under two common environmental policies: the Carbon Tax System and the Emission Trading System. For each system, the impact on profitability and the opportunities for emission cuts are presented. Via numerical experiments we speci...

Ranking fuzzy numbers is an increasingly important research issue in decision making, because it provides support for decision makers to select the best alternative under an uncertain environment. The recent ranking approach for generalized fuzzy numbers by Kumar et al. (Soft Computing, 15(7): 1373–1381, 2011) suffers from common shortcomings assoc...

This study develops a simulated annealing heuristic with restart strategy (SA_RS) for solving the blood pickup routing problem (BPRP). BPRP minimizes the total length of the routes for blood bag collection between a blood bank and a set of donation sites, each associated with a time window constraint that must be observed. The proposed SA_RS is imp...

Green supplier evaluation and selection plays a crucial role in the green supply chain management of any organization to reduce the purchasing cost of materials and increase the flexibility and quality of products. An interval neutrosophic set (INS)-which is a generalization of fuzzy sets, intuitionistic fuzzy sets (IFS) and neutrosophic sets (NS)-...

This research introduces an extension of the share-a-ride problem (SARP), called the general share-a-ride problem (G-SARP). Similarly to SARP, a taxi in G-SARP can service passenger and package requests at the same time. However, G-SARP allows the taxi to transport more than one passenger at the same time, which is more beneficial in practical situ...