Almost minimum-redundancy construction of balanced codes using limited-precision integers

Author(s):  
Danny Dube ◽  
Mounir Mechqrane
Keyword(s):  
2014 ◽  
Vol 25 (05) ◽  
pp. 563-584 ◽  
Author(s):  
PARTHA SARATHI MANDAL ◽  
ANIL K. GHOSH

Location verification in wireless sensor networks (WSNs) is quite challenging in the presence of malicious sensor nodes, which are called attackers. These attackers try to break the verification protocol by reporting their incorrect locations during the verification stage. In the literature of WSNs, most of the existing methods of location verification use a set of trusted verifiers, which are vulnerable to attacks by malicious nodes. These existing methods also use some distance estimation techniques, which are not accurate in noisy channels. In this article, we adopt a statistical approach for secure location verification to overcome these limitations. Our proposed method does not rely on any trusted entities and it takes care of the limited precision in distance estimation by using a suitable probability model for the noise. The resulting verification scheme detects and filters out all malicious nodes from the network with a very high probability even when it is in a noisy channel.


Author(s):  
L. Mandow ◽  
J. L. Perez-de-la-Cruz ◽  
N. Pozas

AbstractThis paper addresses the problem of approximating the set of all solutions for Multi-objective Markov Decision Processes. We show that in the vast majority of interesting cases, the number of solutions is exponential or even infinite. In order to overcome this difficulty we propose to approximate the set of all solutions by means of a limited precision approach based on White’s multi-objective value-iteration dynamic programming algorithm. We prove that the number of calculated solutions is tractable and show experimentally that the solutions obtained are a good approximation of the true Pareto front.


2014 ◽  
Vol 369 (1637) ◽  
pp. 20120461 ◽  
Author(s):  
Bilgehan Çavdaroğlu ◽  
Mustafa Zeki ◽  
Fuat Balcı

Humans and animals time intervals from seconds to minutes with high accuracy but limited precision. Consequently, time-based decisions are inevitably subjected to our endogenous timing uncertainty, and thus require temporal risk assessment. In this study, we tested temporal risk assessment ability of humans when participants had to withhold each subsequent response for a minimum duration to earn reward and each response reset the trial time. Premature responses were not penalized in Experiment 1 but were penalized in Experiment 2. Participants tried to maximize reward within a fixed session time (over eight sessions) by pressing a key. No instructions were provided regarding the task rules/parameters. We evaluated empirical performance within the framework of optimality that was based on the level of endogenous timing uncertainty and the payoff structure. Participants nearly tracked the optimal target inter-response times (IRTs) that changed as a function of the level of timing uncertainty and maximized the reward rate in both experiments. Acquisition of optimal target IRT was rapid and abrupt without any further improvement or worsening. These results constitute an example of optimal temporal risk assessment performance in a task that required finding the optimal trade-off between the ‘speed’ (timing) and ‘accuracy’ (reward probability) of timed responses for reward maximization.


1969 ◽  
Vol 1969 (1) ◽  
pp. 199-207 ◽  
Author(s):  
T.A. Murphy ◽  
L.T. McCarthy

Abstract A procedure for evaluating the effectiveness of oil-dispersing chemicals has been developed. Using the apparatus originally designed for the Navy specification for solvent-emulsifiers, test conditions were adapted to correspond more closely to typical environmental conditions. Test conditions having the greatest effect on dispersant performance included: type of oil, composition of salt water solution, degree of agitation of chemical/oil mixture, and the degree of contact between chemical and oil prior to agitation. Results from this modified procedure, the Simulated Environmental Tank (SET) Test, correspond well with results from simple field tests. Field tests have limited precision and reproducibility. This lack of a reliable index of field performance with which to compare laboratory results hinders refinement of standard test procedures. The SET Test, which produces results corresponding favorably with field performance, to the extent field performance can be determined, and which simulates typical environmental conditions, is proposed as a meaningful interim solution to this problem of dispersant evaluation.


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