3,860 research outputs found
A Bayesian partial identification approach to inferring the prevalence of accounting misconduct
This paper describes the use of flexible Bayesian regression models for
estimating a partially identified probability function. Our approach permits
efficient sensitivity analysis concerning the posterior impact of priors on the
partially identified component of the regression model. The new methodology is
illustrated on an important problem where only partially observed data is
available - inferring the prevalence of accounting misconduct among publicly
traded U.S. businesses
Safety control of monotone systems with bounded uncertainties
Monotone systems are prevalent in models of engineering applications such as transportation and biological networks. In this paper, we investigate the problem of finding a control strategy for a discrete time positive monotone system with bounded uncertainties such that the evolution of the system is guaranteed to be confined to a safe set in the state space for all times. By exploiting monotonicity, we propose an approach to this problem which is based on constraint programming. We find control strategies that are based on repetitions of finite sequences of control actions. We show that, under assumptions made in the paper, safety control of monotone systems does not require state measurement. We demonstrate the results on a signalized urban traffic network, where the safety objective is to keep the traffic flow free of congestion.This work was partially supported by the NSF under grants CPS-1446151 and CMMI-1400167. (CPS-1446151 - NSF; CMMI-1400167 - NSF
Directed Security Policies: A Stateful Network Implementation
Large systems are commonly internetworked. A security policy describes the
communication relationship between the networked entities. The security policy
defines rules, for example that A can connect to B, which results in a directed
graph. However, this policy is often implemented in the network, for example by
firewalls, such that A can establish a connection to B and all packets
belonging to established connections are allowed. This stateful implementation
is usually required for the network's functionality, but it introduces the
backflow from B to A, which might contradict the security policy. We derive
compliance criteria for a policy and its stateful implementation. In
particular, we provide a criterion to verify the lack of side effects in linear
time. Algorithms to automatically construct a stateful implementation of
security policy rules are presented, which narrows the gap between
formalization and real-world implementation. The solution scales to large
networks, which is confirmed by a large real-world case study. Its correctness
is guaranteed by the Isabelle/HOL theorem prover.Comment: In Proceedings ESSS 2014, arXiv:1405.055
Reconstruction of complete interval tournaments
Let and be nonnegative integers ,
be a multigraph on vertices in which any pair of
vertices is connected with at least and at most edges and \textbf{v =}
be a vector containing nonnegative integers. We give
a necessary and sufficient condition for the existence of such orientation of
the edges of , that the resulted out-degree vector equals
to \textbf{v}. We describe a reconstruction algorithm. In worst case checking
of \textbf{v} requires time and the reconstruction algorithm works
in time. Theorems of H. G. Landau (1953) and J. W. Moon (1963) on the
score sequences of tournaments are special cases resp. of our result
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