10,470 research outputs found

    A novel planning approach for the water, sanitation and hygiene (WaSH) sector: the use of object-oriented bayesian networks

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    Conventional approaches to design and plan water, sanitation, and hygiene (WaSH) interventions are not suitable for capturing the increasing complexity of the context in which these services are delivered. Multidimensional tools are needed to unravel the links between access to basic services and the socio-economic drivers of poverty. This paper applies an object-oriented Bayesian network to reflect the main issues that determine access to WaSH services. A national Program in Kenya has been analyzed as initial case study. The main findings suggest that the proposed approach is able to accommodate local conditions and to represent an accurate reflection of the complexities of WaSH issues, incorporating the uncertainty intrinsic to service delivery processes. Results indicate those areas in which policy makers should prioritize efforts and resources. Similarly, the study shows the effects of sector interventions, as well as the foreseen impact of various scenarios related to the national Program.Preprin

    Spectral Norm of Symmetric Functions

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    The spectral norm of a Boolean function f:{0,1}n{1,1}f:\{0,1\}^n \to \{-1,1\} is the sum of the absolute values of its Fourier coefficients. This quantity provides useful upper and lower bounds on the complexity of a function in areas such as learning theory, circuit complexity, and communication complexity. In this paper, we give a combinatorial characterization for the spectral norm of symmetric functions. We show that the logarithm of the spectral norm is of the same order of magnitude as r(f)log(n/r(f))r(f)\log(n/r(f)) where r(f)=max{r0,r1}r(f) = \max\{r_0,r_1\}, and r0r_0 and r1r_1 are the smallest integers less than n/2n/2 such that f(x)f(x) or f(x)parity(x)f(x) \cdot parity(x) is constant for all xx with xi[r0,nr1]\sum x_i \in [r_0, n-r_1]. We mention some applications to the decision tree and communication complexity of symmetric functions

    A Survey of Quantum Learning Theory

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    This paper surveys quantum learning theory: the theoretical aspects of machine learning using quantum computers. We describe the main results known for three models of learning: exact learning from membership queries, and Probably Approximately Correct (PAC) and agnostic learning from classical or quantum examples.Comment: 26 pages LaTeX. v2: many small changes to improve the presentation. This version will appear as Complexity Theory Column in SIGACT News in June 2017. v3: fixed a small ambiguity in the definition of gamma(C) and updated a referenc

    Combining All Pairs Shortest Paths and All Pairs Bottleneck Paths Problems

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    We introduce a new problem that combines the well known All Pairs Shortest Paths (APSP) problem and the All Pairs Bottleneck Paths (APBP) problem to compute the shortest paths for all pairs of vertices for all possible flow amounts. We call this new problem the All Pairs Shortest Paths for All Flows (APSP-AF) problem. We firstly solve the APSP-AF problem on directed graphs with unit edge costs and real edge capacities in O~(tn(ω+9)/4)=O~(tn2.843)\tilde{O}(\sqrt{t}n^{(\omega+9)/4}) = \tilde{O}(\sqrt{t}n^{2.843}) time, where nn is the number of vertices, tt is the number of distinct edge capacities (flow amounts) and O(nω)<O(n2.373)O(n^{\omega}) < O(n^{2.373}) is the time taken to multiply two nn-by-nn matrices over a ring. Secondly we extend the problem to graphs with positive integer edge costs and present an algorithm with O~(tc(ω+5)/4n(ω+9)/4)=O~(tc1.843n2.843)\tilde{O}(\sqrt{t}c^{(\omega+5)/4}n^{(\omega+9)/4}) = \tilde{O}(\sqrt{t}c^{1.843}n^{2.843}) worst case time complexity, where cc is the upper bound on edge costs

    Discrete and fuzzy dynamical genetic programming in the XCSF learning classifier system

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    A number of representation schemes have been presented for use within learning classifier systems, ranging from binary encodings to neural networks. This paper presents results from an investigation into using discrete and fuzzy dynamical system representations within the XCSF learning classifier system. In particular, asynchronous random Boolean networks are used to represent the traditional condition-action production system rules in the discrete case and asynchronous fuzzy logic networks in the continuous-valued case. It is shown possible to use self-adaptive, open-ended evolution to design an ensemble of such dynamical systems within XCSF to solve a number of well-known test problems

    Privacy-Aware Processing of Biometric Templates by Means of Secure Two-Party Computation

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    The use of biometric data for person identification and access control is gaining more and more popularity. Handling biometric data, however, requires particular care, since biometric data is indissolubly tied to the identity of the owner hence raising important security and privacy issues. This chapter focuses on the latter, presenting an innovative approach that, by relying on tools borrowed from Secure Two Party Computation (STPC) theory, permits to process the biometric data in encrypted form, thus eliminating any risk that private biometric information is leaked during an identification process. The basic concepts behind STPC are reviewed together with the basic cryptographic primitives needed to achieve privacy-aware processing of biometric data in a STPC context. The two main approaches proposed so far, namely homomorphic encryption and garbled circuits, are discussed and the way such techniques can be used to develop a full biometric matching protocol described. Some general guidelines to be used in the design of a privacy-aware biometric system are given, so as to allow the reader to choose the most appropriate tools depending on the application at hand
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