## About

29

Publications

31,154

Reads

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441

Citations

Citations since 2017

Introduction

Since 2003 until 2018.01, I have advised 38 master students, 5 groups of undergraduate students. They have received 12 conference paper awards, 26 thesis competition awards, and 9 projects awards.
Of all the awards, I am most glad to lead a team "NCKU" that has won the INFORMS RAS competition awards for 6 times: Honorable mentions in 2010, 2013, the 3rd place in 2011, the 2nd place in 2014, 2016, and the 1st place (with team OALIIM composed by my students) in 2017..

Additional affiliations

August 2007 - July 2014

**National Cheng Kung University**

Position

- Professor

Description

- I teach network optimization, supply chain management, data structure, algorithms, discrete mathematics, and C++ coding.

Education

September 1998 - May 2003

September 1997 - June 1998

January 1994 - February 1996

## Publications

Publications (29)

Public bike sharing systems have become the most popular shared economy application in transportation. The convenience of this system depends on the availability of bikes and empty racks. One of the major challenges in operating a bike sharing system is the repositioning of bikes between rental sites to maintain sufficient bike inventory in each st...

This study discusses a multi-UAV surveillance routing problem that routes a UAV fleet from a base station to periodically capture data from sensing locations in a store-and-forward fashion during the planning horizon. Cooperated UAVs can wirelessly transfer data within communication range to gain the maximum collected data received at the base stat...

We investigate a carrier vehicle traveling salesman problem (CVTSP) to visit n-targets in Euclidean space. Each target is visited by a smaller vehicle (e.g., UAV) consecutively, launched from and landed to a carrier. The smaller vehicle and the carrier must synchronize during both launching and landing. We present a mixed-integer second-order cone...

This paper is to appear in "Numerical Algebra, Control and Optimization" (NACO) in 2021 June. The author proposed the idea and the first mathematical programming models of crowdsourced dynamic repositioning around 2011, which were firstly published in Liao (2012). This paper (Wang and Hou, 2021), based on Hou (2016), has further made the idea more...

In this paper, an effective mechanism using a fleet of unmanned surface vehicles (USVs) carried by a parent boat (PB) is proposed to complete search or scientific tasks over multiple target water areas within a shorter time. Specifically, multiple USVs can be launched from the PB to conduct such operations simultaneously, and each USV can return to...

The multicommodity network flow (MCNF) problem arises often in logistics and telecommunication applications such as network design or routing problems. In particular, MCNF appears when more than one commodity (cargo, packet, or personnel) needs to be shipped between specific node pairs without violating the capacity constraints associated with the...

The multicommodity network fl ow (MCNF) problem is an important and challenging topic in many scheduling and routing applications. As a follow-up survey paper to the previous one that focus on the MCNF applications and formulations, this paper first introduces the conventional MCNF solution methods such as price-directive, resource-directive, and b...

Electrical vehicles (EVs) have become a popular green transportation means recently because they have lower energy consumption costs and produce less pollution. The success of EVs relies on technologies to extend their driving range, which can be achieved by the good deployment of EV recharging stations. This paper considers a special EV network co...

In a distribution network, materials or products that go through a decomposition process can be considered as flows entering a specialized node, called D-node, which distributes each decomposed flow along an outgoing arc. Flows on each arc emanating from a D-node have to obey a pre-specified proportional relationship, in addition to the capacity co...

Unlike most recent shortest path algorithms that converge based on graphical operations, we
propose an algebraic all pairs shortest path algorithm based on LU decomposition of a measure matrix
recording arc lengths. Our algorithm is capable of identifying negative cycles of the graph in fewer iterations
than Floyd-Warshall algorithm does, and is at...

We develop practical OR models to support decision making in the design and management of public bicycle-sharing systems. We develop a network flow model with proportionality constraints to estimate the flow of bicycles within the network and the number of trips supported, given an initial allocation of bicycles at each station. We also examine the...

With the contributions on reducing the traffic congestion and air pollution, bike sharing systems become more popular recently in many metropolitan areas worldwide. Without effective bike redistribution strategies, a bike rental station may easily become out or full of bikes, which incurs the customer inconvenience and conflicts its purpose. In ord...

We investigate a difficult scheduling problem in a semiconductor manufacturing process that seeks to minimize the number of tardy jobs and makespan with sequence-dependent setup time, release time, due dates and tool constraints. We propose a mixed integer programming (MIP) formulation which treats tardy jobs as soft constraints so that our objecti...

This paper investigates a difficult scheduling problem on a specialized two-stage hybrid flow shop with multiple processors
that appears in semiconductor manufacturing industry, where the first and second stages process serial jobs and parallel batches,
respectively. The objective is to seek job-machine, job-batch, and batch-machine assignments suc...

Recently a new least-squares primal-dual (LSPD) algorithm, that is impervious to degeneracy, has effectively been applied to solving linear programming problems by Barnes et al., 2002. In this paper, we show an application of LSPD to shortest path problems with nonnegative arc length is equivalent to the Dijkstra's algorithm. We also compare the LS...

The population haplotype inference problem based on the pure parsimony criterion (HIPP) infers an m×n genotype matrix for a population by a 2m×n haplotype matrix with the minimum number of distinct haplotypes. Previous integer programming based HIPP solution methods are time-consuming, and their practical effectiveness remains unevaluated. On the o...

Although the haplotype data can be used to analyze the function of DNA, due to the significant efforts required in collecting the haplotype data, usually the genotype data is collected and then the population haplotype inference (PHI) problem is solved to infer haplotype data from genotype data for a population. This paper investigates the PHI prob...

To model the distillation or decomposition of products in some manufacturing processes, a minimum distribution cost problem (MDCP) for a specialized manufacturing network flow model has been investigated. In an MDCP, a specialized node called a D-node is used to model a distillation process that connects with a single incoming arc and several outgo...

In this paper, we consider special minimum cost flow problem in a kind of manufacturing network recently introduced by Fang and Qi [5] called as a distribution network. A new kind of nodes, called D-nodes, are incorporated to describe a distilling operation that decomposes one raw-material to several products with fixed ratios. The arc capacity in...

Small packages such as important documents, receipts and gifts are usually distributed in a short time window in a metropolitan area of congested traffic and limited parking spaces. While conventional four-wheel vehicles are not suitable for intra-city deliveries, motorcycles are perfect since they are more mobile. This paper tries to investigate b...

This paper investigates a mixed-integer linear programming model that solves an integrated facility location and configuration problem for recycling electronic waste (e-waste). Since different recycled e-waste consume different levels of recycling processes and resources, the capability of processing only one or more categories of recycled e-waste...

We are concerned with the maximum flow problem in the distribution network, a new kind of network recently introduced by Fang and Qi. It differs from the traditional network by the presence of the D-node through which the commodities are to be distributed proportionally. Adding D-nodes complicates the network structure. Particularly, flows in the d...

To analyze the function of DNA, researchers have to obtain each haplotype, the genetic constitution of an individual chromosome, of an individual for analysis. Due to the significant efforts required in collecting haplotypes, the descriptions of one conflated pair of haplotypes called genotypes are usually collected. Since the genotype data contain...

The multiple pairs shortest path problem (MPSP) arises in many applications where the shortest paths and distances between only some specific pairs of origin-destination (OD) nodes in a network are desired. The traditional repeated single-source shortest path (SSSP) and all pairs shortest paths (APSP) algorithms often do unnecessary computation to...

The maximum flow (max-flow) problem is a fundamental network optimization problem which computes for the largest possible amount of flow sent through the network from a source node to a sink node. This problem appears in many applications and has been investigated extensively over the recent four decades. Traditional max-flow problem may require so...

## Questions

Questions (2)

From the textbook, it is easy to understand that building a red-black tree of n internal nodes takes O(nlogn) time. However, I am looking for the lower bound on this complexity, i.e. how to prove this takes Omega(nlogn) time, for the case where the input is a sorted list (e.g. inserting 1,2,3,4,...,n one by one for a red-black tree)?

Considering a connected communication network G=(N,A), where an arc (i,j) in A may be broken and requires time t(i,j) for fixing it (if it is not broken, set it as a very small number). Now, suppose we start from the root node with unlimited number of workforce to fix all the broken arcs. What is the earliest time to make all nodes accessible from the root node? This problem is equivalent to seek a spanning tree in which each path from the root to a leaf presenting a fixing sequence of arcs for a team and the length of a longest path from the root to a leaf represent the completion time for making all nodes accessible from the root. This is different from the diameter of the graph, which defines the longest path between all pairs of nodes. This is not related with minimum spanning tree, either, since the spanning tree I seek may not be an MST. If you have seen any problem similar or related with this one, please let me know.

## Projects

Projects (5)

new shortest path algorithms:
1. Based on matrix inversion (LU decomposition):
new Multiple-Pairs (SOME-SOME) Shortest Paths
new Algebraic All-Pairs (ALL-ALL) Shortest Paths
2. Based on NonNegative Least Squares Primal-Dual nondegenerate pivot rules
Note that these algorithms may perform better for dense networks.

Review, Design new Models and Solution Methods for solving the Min-cost Multicommodity Network Flow problems (MCMCNF), especially Origin-Destination MCMCNF.
One major contribution is to summarize literatures.
Another was to test how the key-path formulation works.