In this paper, we consider the design of large-scale hub-and-spoke transportation networks in a competitive environment. We adopt the hub arc location model that locates arcs with discounted transport costs connecting pairs of hub facilities. Two firms compete for passengers in a Stackelberg framework where the leader firm locates hub arcs to maximize its revenue, given that the follower firm w...

We consider the hub location problem, where p hubs are chosen from a given set of nodes, each nonhub node is connected to exactly one hub and each hub is connected to a central hub. Links are installed on the arcs of the resulting network to route the traffic. The aim is to find the hub locations and the connections to minimize the link installation cost. We propose two formulations and a heuri...

The airlines reorganization will accelerate the switch of the Chinese mainland civil aviation system from a former point-to-point (PP) structure to a hub-and-spoke (HS) network. In such a context, the major efforts of our paper are put into identifying hub airports in mainland China. We first analyze the HS network’s competitive advantages and find four desirable hub characteristics. A three-le...

INTRODUCTION Sci-Hub is a useful web portal for people working in science as it provides access to millions of free scientific articles. Satisfaction and usage should be explored in the Latino student population. The objective of this study was to evaluate the use, knowledge, and perception of the scientific contribution of Sci-Hub in medical students from Latin America. METHODOLOGY A multice...

Abstract Considering the serious wear of disk cutters in tunnel project and low prediction accuracy existing methods, a new method for from an energy perspective was proposed. Based on contact mechanics, rock breaking process analyzed, combined action sliding rolling friction considered. Furthermore, model established, which realized predicted under different geological conditions throughout co...

Due to the great expansion of woodworking, profile tools manufacturing has become current and in demand. In wood industry there are two large groups tools: rotary spindle milling cutters that can be or flat. The technology making requires, apart from cutting, turning, milling, 5-axis grinding operation is performed on a CNC machine with A'OXYZC configuration.It very complex kinematics high cost...

RESEARCH ARTICLE Numerical Analysis on Rock Breaking by Disc Cutters with Different Joint Characteristics Tan Qing, Yi Nian-en, Xia Yi-min, Zhang Xu-hui, Jiang Bo, Yang Yang and Yizeng Siyuan State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha, Hunan 410083, China School of Mechanical and Electrical Engineering, Central South University, Changsha, ...