GRASP with Hybrid Path Relinking for Bi-Objective Winner Determination in Combinatorial Transportation Auctions

The procurement of transportation services via large-scale combinatorial auctions involves a couple of complex decisions whose outcome highly influences the performance of the tender process. This paper examines the shipper's task of selecting a subset of the submitted bids which efficiently trades off total procurement cost against expected carrier performance. To solve this bi-objective winner determination problem, we propose a Pareto-based greedy randomized adaptive search procedure (GRASP). As a post-optimizer we use a path relinking procedure which is hybridized with branch-and-bound. Several variants of this algorithm are evaluated by means of artificial test instances which comply with important real-world characteristics. The two best variants prove superior to a previously published Pareto-based evolutionary algorithm.

Is a General Theory of Socially Disapproved Violence Possible (or Necessary)?

A model of theoretical science is set forth to guide the formulation of general theories around abstract concepts and processes. Such theories permit explanatory application to many phenomena that are not ostensibly alike, and in so doing encompass socially disapproved violence, making special theories of violence unnecessary. Though none is completely adequate for the explanatory job, at least seven examples of general theories that help account for deviance make up the contemporary theoretical repertoire. From them, we can identify abstractions built around features of offenses, aspects of individuals, the nature of social relationships, and different social processes. Although further development of general theories may be hampered by potential indeterminacy of the subject matter and by the possibility of human agency, maneuvers to deal with such obstacles are available.