Environmental Impact of Steel and Fiber–Reinforced Polymer Reinforced Pavements

The environmental load of fiber-reinforced polymer (FRP) reinforced pavement was compared with that of steel reinforced pavement. Replacing steel rebars with FRP rebars can lead to changes in the concrete mix and pavement structure at the erection stage, to a reduced need for maintenance activities related to steel corrosion, and to different recycling opportunities at the disposal stage. The current study examined all of these variables. The environmental load of FRP reinforced pavement was found to be significantly lower than that of steel reinforced pavement. This results mainly from the fact that FRP reinforced pavement requires less maintenance, its cement content and concrete cover over reinforcement can be reduced, and the reinforcement itself generates a smaller environmental load.     

Detection and reduction of evolutionary noise in correlated mutation analysis

Direct or indirect inter-residue interactions in proteins are often reflected by mutations at one site that compensate for mutations at another site. Various bioinformatic methods have been developed for detecting such correlated mutations in order to obtain information about intra- and inter-protein interactions. Here, we show by carrying out a correlated mutation analysis for non-interacting proteins that the signal due to inter-residue interactions is of similar magnitude to the 'noise' that arises from other evolutionary processes related to common ancestry. A new method for detecting correlated mutations is presented that reduces this evolutionary noise by taking into account evolutionary distances in the protein family. It is shown that this method yields better signal-to-noise ratios and, therefore, can much better resolve, for example, correlated mutations that reflect true inter-residue interactions.     

Uniform hardness versus randomness tradeoffs for Arthur-Merlin games

Impagliazzo and Wigderson proved a uniform hardness vs. randomness gap theorem for BPP. We show an analogous result for AM: Either Arthur-Merlin protocols are very strong and everything in can be proved to a subexponential time verifier, or else Arthur-Merlin protocols are weak and every language in AM has a polynomial time nondeterministic algorithm such that it is infeasible to come up with inputs on which the algorithm fails. We also show that if Arthur-Merlin protocols are not very strong (in the sense explained above) then Our technique combines the nonuniform hardness versus randomness tradeoff of Miltersen and Vinodchandran with instance checking. A key ingredient in our proof is identifying a novel resilience property of hardness vs. randomness tradeoffs.     

Distributed constraint satisfaction with partially known constraints

Distributed constraint satisfaction problems (DisCSPs) are composed of agents connected by constraints. The standard model for DisCSP search algorithms uses messages containing assignments of agents. It assumes that constraints are checked by one of the two agents involved in a binary constraint, hence the constraint is fully known to both agents. This paper presents a new DisCSP model in which constraints are kept private and are only partially known to agents. In addition, value assignments can also be kept private to agents and not be circulated in messages. Two versions of a new asynchronous backtracking algorithm that work with partially known constraints (PKC) are presented. One is a two-phase asynchronous backtracking algorithm and the other uses only a single phase. Another new algorithm preserves the privacy of assignments by performing distributed forward-checking (DisFC). We propose to use entropy as quantitative measure for privacy. An extensive experimental evaluation demonstrates a trade-off between preserving privacy and the efficiency of search, among the different algorithms. Partially supported by the Spanish project TIN2006-15387-C03-01. Partially supported by the Lynn and William Frankel center for Computer Sciences and the Paul Ivanier Center for Robotics and Production Management.     

Generation of random series in two-person strictly competitive games.

A general conclusion, widely and uniformly supported by a variety of experiments, is that humans are unable to produce a random series of discrete responses, even when instructed to do so. Several arguments are advanced to show that the experimental evidence in support of this claim is plagued with logical and methodological difficulties. Using a new research paradigm, this article reports experimental results showing that people can generate binary sequences that satisfy standard tests of randomness more successfully when they participate in 2-person strictly competitive games inducing them to conceal their choices and protect themselves from their own frailty to maximize gain. The results are discussed within the framework of existing theories of cognitive biases in random-sequence generation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Immersion and invariance based fault tolerant adaptive spacecraft attitude control

In this paper, an immersion and invariance (I&I) adaptive fault tolerant satellite attitude tracking control scheme is proposed. The proposed controller is capable of track the desired trajectory in the presence of unknown actuator multiplicative faults and unknown inertial matrix. Also based on Lyapunov direct method, all closed loop signals are proven to be globally asymptotically stable. The main advantage of this controller is improving closed loop performance while maintaining stability in the presence of unknown actuator faults. This method does not rely on certainty equivalence principle so it can be used to control the transient response of overall closed loop system by means of controlling the parameter estimation behavior which is not possible in traditional adaptive control. Numerical simulations are performed to demonstrate the effectiveness of proposed control scheme.     

Identification of informal reasoning fallacies as a function of epistemological level, grade level, and cognitive ability.

Informal reasoning fallacies are violations of critical discussion norms. As epistemological understanding of knowledge justification appears to underlie the informal reasoning skills of argument construction and evaluation, it was hypothesized that adolescents with greater epistemological sophistication would be more able to identify informal reasoning fallacies. It was hypothesized that 11th graders would be more epistemologically sophisticated than 7th or 9th graders and, thus, would more likely identify fallacies. Students responded to questions regarding argument scenarios that did or did not contain fallacies. More 11th graders identified fallacies. Epistemological level predicted only identification of one type of fallacy that might be described as epistemological in nature. Cognitive ability also seemed to contribute to the increased ability with grade to identify fallacies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multiple View Geometry of General Algebraic Curves

We introduce a number of new results in the context of multi-view geometry from general algebraic curves. We start with the recovery of camera geometry from matching curves. We first show how one can compute, without any knowledge on the camera, the homography induced by a single planar curve. Then we continue with the derivation of the extended Kruppa's equations which are responsible for describing the epipolar constraint of two projections of a general algebraic curve. As part of the derivation of those constraints we address the issue of dimension analysis and as a result establish the minimal number of algebraic curves required for a solution of the epipolar geometry as a function of their degree and genus.We then establish new results on the reconstruction of general algebraic curves from multiple views. We address three different representations of curves: (i) the regular point representation in which we show that the reconstruction from two views of a curve of degree d admits two solutions, one of degree d and the other of degree d(d – 1). Moreover using this representation, we address the problem of homography recovery for planar curves, (ii) dual space representation (tangents) for which we derive a lower bound for the number of views necessary for reconstruction as a function of the curve degree and genus, and (iii) a new representation (to computer vision) based on the set of lines meeting the curve which does not require any curve fitting in image space, for which we also derive lower bounds for the number of views necessary for reconstruction as a function of curve degree alone.