We analyze congested network-based markets and their impact on competition, equilibrium charges and efficiency. Several strategies are explored including price caps, mergers and investments in new technologies. We fin...
详细信息
We analyze congested network-based markets and their impact on competition, equilibrium charges and efficiency. Several strategies are explored including price caps, mergers and investments in new technologies. We find that congested networks served by collaborating (serial) and competing (parallel) firms may lead to excessive prices. Additionally, oligopolists may only serve captive demand, leading to inefficiently low flows. Perhaps surprisingly, permitting a firm with market power to horizontally integrate with a competitor may improve efficiency. We also show that price caps in congested networks are ineffective due to their failure to signal the existence of scarce resources. Instead, partial vertical integration may prove beneficial by creating incentives to expand capacity through technology adoption, provided the price cap regime is dropped. The model is subsequently illustrated with a case study of air traffic control provision in Western Europe, in which it is shown that substantial changes in the regulation are required in order to create a more cost efficient sector with increased capacity.
We investigate the epistemology of trust in social networks. We posit trust as a special epistemic state that depends on actors' beliefs about each others' beliefs as well as about states of the world. It offe...
详细信息
We investigate the epistemology of trust in social networks. We posit trust as a special epistemic state that depends on actors' beliefs about each others' beliefs as well as about states of the world. It offers new ideas and tools for representing the core elements of trust both within dyads and larger groups and presents an approach that makes trust measurable in a noncircular and predictive, rather than merely postdictive, fashion. After advancing arguments for the importance of interactive belief systems to the successful coordination of behavior, we tune our investigation of trust by focusing on beliefs that are important to mobilization and coordination and show how trust functions to influence social capital arising from network structure. We present empirical evidence corroborating the importance of higher-order beliefs to understanding trust and the interactive analysis of trust to the likelihood of successful coordination.
We consider the problem of minimizing renewable resource availability costs in an activity-on-the-node project network subject to a project due date. Project activities have fixed durations and may require the use of ...
详细信息
We consider the problem of minimizing renewable resource availability costs in an activity-on-the-node project network subject to a project due date. Project activities have fixed durations and may require the use of multiple renewable resources in constant amounts throughout their duration. Various assumptions may be made about the type of precedence relations, ready times, due dates, and task interruptability. Given a discrete, non-decreasing cost function of the constant resource availability for every resource type, the objective is to determine the resource availability levels in order to minimize the sum of the availability costs over all resource types. An effective optimal algorithm is described and extensive computational experience is reported.
Given an undirected graph the 2-Peripatetic Salesman Problem (PSP) is the problem that aims to minimize the total length of 2 edge-disjoint Hamiltonian cycles. We consider a generalization of the problem (GPSP), where...
详细信息
Given an undirected graph the 2-Peripatetic Salesman Problem (PSP) is the problem that aims to minimize the total length of 2 edge-disjoint Hamiltonian cycles. We consider a generalization of the problem (GPSP), where each cycle visits each vertex at most (instead of exactly) once and a penalty has to be paid for each unvisited vertex. We will show that the generalized problem can be solved by finding 2 edge-disjoint paths. The path problem in turn can be transformed into a standard PSP, so that the GPSP is solvable by a standard PSP algorithm. We will discuss some special cases of the GPSP.
This note develops a fathoming procedure for the Dynamic Plant Layout Problem (DPLP) discussed by Rosenblatt (1986) in this journal. This procedure can be used to reduce the number of candidate static layouts to be ex...
详细信息
This note develops a fathoming procedure for the Dynamic Plant Layout Problem (DPLP) discussed by Rosenblatt (1986) in this journal. This procedure can be used to reduce the number of candidate static layouts to be examined. An important feature of our procedure is that a feasible dynamic solution is not required in order to apply it. The effectiveness of this procedure depends on the relative magnitude of the shifting costs.
Let K be contained in the vertex-set of a graph G. ''The most vital edge'' is the edge whose deletion yields the largest decrease in the K-terminal reliability, that is the probability that all vertice...
详细信息
Let K be contained in the vertex-set of a graph G. ''The most vital edge'' is the edge whose deletion yields the largest decrease in the K-terminal reliability, that is the probability that all vertices in K are connected. In this paper, we present a linear-time algorithm for finding the most vital edge with respect to K-terminal reliability in series-parallel networks.
Given a graph G = (V, E), positive integers D < Absolute value of V and B, the Minimum-Cardinality-Bounded-Diameter (MCBD) Edge Addition Problem is to find a superset of edges E' superset-or-equal-to E such tha...
详细信息
Given a graph G = (V, E), positive integers D < Absolute value of V and B, the Minimum-Cardinality-Bounded-Diameter (MCBD) Edge Addition Problem is to find a superset of edges E' superset-or-equal-to E such that the graph G' = (V, E') has diameter no greater than D and the total number of the new edges is minimized, while the Bounded-Cardinality-Minimum-Diameter (BCMD) Edge Addition Problem is to find a superset of edges E' superset-or-equal-to E with \E'\E\ less-than-or-equal-to B such that the diameter of G' = (V, E') is minimized. We prove that the MCBD case is NP-hard even when D = 2 and describe a polynomial heuristic for BCMD with a constant worst-case bound. We also show that finding a polynomial heuristic for MCBD with a constant worst-case bound is no easier than finding such a heuristic for the dominating set problem.
Many transportation networks, e.g., networks of cooperating power systems, and hydrological networks involve a real-valued demand function, defined on the set of nodes, and it is said to be feasible if there exists a ...
详细信息
Many transportation networks, e.g., networks of cooperating power systems, and hydrological networks involve a real-valued demand function, defined on the set of nodes, and it is said to be feasible if there exists a flow such that at each node the sum of the incoming flow values is greater than or equal to the demand assigned to this node. By the theorem of D. Gale and A. Hoffman, a system of linear inequalities involving the demand and the arc capacity functions, gives necessary and sufficient condition for the feasibility of the demand. If the demands and/or the arc capacities are random, then an important problem is to find the probability that all these inequalities are satisfied. This paper proposes a new method to eliminate all redundant inequalities for given lower and upper bounds of the demand function, and finds sharp lower and upper bounds for the probability that a feasible flow exists. The results can be used to support transportation network analysis and design.
This paper presents a class of facet-defining inequalities for an assignment problem with the additional constraints that specified variables are required to be equal to each other. In a special case, the complete pol...
详细信息
This paper presents a class of facet-defining inequalities for an assignment problem with the additional constraints that specified variables are required to be equal to each other. In a special case, the complete polyhedral description is given.
A research theme involving location on networks, since its inception, has been the identification of a finite dominating set (FDS), or a finite set of points to which an optimal solution must belong. We attempt to uni...
详细信息
A research theme involving location on networks, since its inception, has been the identification of a finite dominating set (FDS), or a finite set of points to which an optimal solution must belong. We attempt to unify and generalize results of this sort. We survey the literature and then prove some theorems that subsume most previous results and that are, at the same time, more genral than previous results. The paper is aimed primarily at investigators who wish to know whether an FDS exists for a specific problem.
暂无评论