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Doron Zarchy

Publications and source records attributed to Doron Zarchy.

3 recordsLinked to original sources

Theoretical and Experimental Analysis of the Canadian Traveler Problem

Devising an optimal strategy for navigation in a partially observable environment is one of the key objectives in AI. One of the problem in this context is the Canadian Traveler Problem (CTP). CTP is a navigation problem where an agent is tasked to travel from source to target in a partially observable weighted graph, whose edge might be blocked with a certain probability and observing such blockage occurs only when reaching upon one of the edges end points. The goal is to find a strategy that minimizes the expected travel cost. The problem is known to be P$\#$ hard. In this work we study the CTP theoretically and empirically. First, we study the Dep-CTP, a CTP variant we introduce which assumes dependencies between the edges status. We show that Dep-CTP is intractable, and further we analyze two of its subclasses on disjoint paths graph. Second, we develop a general algorithm Gen-PAO that optimally solve the CTP. Gen-PAO is capable of solving two other types of CTP called Sensing-CTP and Expensive-Edges CTP. Since the CTP is intractable, Gen-PAO use some pruning methods to reduce the space search for the optimal solution. We also define some variants of Gen-PAO, compare their performance and show some benefits of Gen-PAO over existing work.

cs.AI

Nash-Peering: A New Techno-Economic Framework for Internet Interconnections

The current framework of Internet interconnections, based on transit and settlement-free peering relations, has systemic problems that often cause peering disputes. We propose a new techno-economic interconnection framework called Nash-Peering, which is based on the principles of Nash Bargaining in game theory and economics. Nash-Peering constitutes a radical departure from current interconnection practices, providing a broader and more economically efficient set of interdomain relations. In particular, the direction of payment is not determined by the direction of traffic or by rigid customer-provider relationships but based on which AS benefits more from the interconnection. We argue that Nash-Peering can address the root cause of various types of peering disputes.

cs.GT

PCC: Re-architecting Congestion Control for Consistent High Performance

TCP and its variants have suffered from surprisingly poor performance for decades. We argue the TCP family has little hope to achieve consistent high performance due to a fundamental architectural deficiency: hardwiring packet-level events to control responses without understanding the real performance result of its actions. We propose Performance-oriented Congestion Control (PCC), a new congestion control architecture in which each sender continuously observes the connection between its actions and empirically experienced performance, enabling it to consistently adopt actions that result in high performance. We prove that PCC converges to a stable and fair equilibrium. Across many real-world and challenging environments, PCC shows consistent and often 10x performance improvement, with better fairness and stability than TCP. PCC requires no router hardware support or new packet format.

cs.NI