Networks is celebrating its 50th Anniversary with a special issue!
The 10 papers appearing in this first of two special issues, guest edited by S. Ragavan and J. Cole Smith, cover the history of Networks, update key developments that have been published in this field, and present new results that kick off ideas for the next half‐century of networks research. The Editors‐in‐Chief of Networks since 1999, Drs Bruce Golden and Doug Shier, begin the issue by discussing Network‘s evolution over the past two decades. Frisch, who co‐authored an article in Volume 1, Issue 1 of Networks, tells the story of the first three decades of Networks. (This article is a reprint of Frisch’s 30‐year history of Networks published in 2001.) Hochbaum then presents new research on integer programming formulations that can be solved efficiently using combinatorial flow algorithms. The special class of problems considered in this paper are common across many classes of practical optimization problems, including those having network structures.
The next set of articles are retrospective works on some of the most‐studied application areas of network modeling and algorithms. Nagurney examines network‐based developments in economics and finance over the last half‐century, with a particular eye toward the role of Networks in disseminating those contributions. This overview covers network optimization in network game theory, equilibrium models, and dynamical systems. Wang and Wasil follow this article with a 50‐year retrospective of vehicle routing problems, noting in particular that Networks has published over 140 articles in this area since its inception, and thus stands as one of the world’s foremost sources for this important research field.
Related to vehicle routing is the field of arc routing, reviewed in the work of Corberan et al. Their article serves as a tutorial for those seeking to understand arc routing models, as a survey of the literature in this field, and also as a prospective discussion of emerging arc routing research challenges. A separate perspective on routing comes in the air, as examined by Poikonen and Campbell. Routing problems using drones (or more formally, unmanned aerial vehicles [UAVs]) have become prevalent in the past decade and promise to become even more ubiquitous in the coming years. Poikonen and Campbell look beyond traveling‐salesman and vehicle‐routing types of problems for UAVs and toward the study of new optimization problems that are unique to UAV deployment and operations.
This special issue continues with two classical practical applications of networks. With network flow models being a natural vehicle for addressing evacuation optimization problems, the journal Networks has published several impactful evacuation studies. Hasan and Van Hentenryck examine models and algorithms for evacuation planning, synthesizing their development, and contributing new ideas to complement those in the literature. (The second part of their study will appear in the subsequent issue of Networks, which continues the 50th anniversary celebration of the journal.) The second practical application regards network reliability, studied by Brown et al. The notion of network reliability predates even the creation of this journal, and because of the practical relevance of network reliability to industrial applications, the field has become stunningly large. Brown et al. discuss the breadth of network reliability problems and definitions, along with theory, algorithms, and applications associated with this field.
Anchoring this issue is the work of Hicks and Brimkov, which revisits a classic paper authored by Hicks that appeared 16 years ago in Networks. These studies are rooted in concepts related to branch decomposition and branchwidth; these concepts can in turn be used to solve certain classes of combinatorial optimization problems. Hicks and Brimkov’s results update the original paper and demonstrate how tangle bases can be used to construct branch decompositions having branchwidth small enough to allow their use in combinatorial algorithms.
Twenty‐one years in the life of Networks (2000 to 2020). Networks. 2021; 77: 5– 13. https://doi.org/10.1002/net.21986, .
Frisch, I.T. (2021), The Early Days of Networks. Networks, 77: 14-20. https://doi.org/10.1002/net.21927
Special Issue Papers
Applications and efficient algorithms for integer programming problems on monotone constraints. Networks.. 2021; 77: 21– 49. https://doi.org/10.1002/net.21983.
Networks in economics and finance in Networks and beyond: A half century retrospective. Networks. 2021; 77: 50– 65. https://doi.org/10.1002/net.21920.
On the road to better routes: Five decades of published research on the vehicle routing problem. Networks.. 2021; 77: 66– 87. https://doi.org/10.1002/net.21942, .
Arc routing problems: A review of the past, present, and future. Networks. 2021; 77: 88– 115. https://doi.org/10.1002/net.21965, , , , .
Future directions in drone routing research. Networks. 2021; 77: 116– 126. https://doi.org/10.1002/net.21982, .
Large‐scale zone‐based evacuation planning—Part I: Models and algorithms. Networks. 2021; 77: 127– 145. https://doi.org/10.1002/net.21981, .
Network reliability: Heading out on the highway. Networks.. 2021; 77: 146– 160. https://doi.org/10.1002/net.21977, , , , .
Tangle bases: Revisited. Networks. 2021; 77: 161– 172. https://doi.org/10.1002/net.21979, .