371 research outputs found

    Pit Slope Failure Problems in Goan Iron Ore Mines, Goa, India

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    The problem of open pit slope stability is a matter of concern when the mining operations go deeper followed by weak strata conditions. In Goa iron ore mines the problem of slope instability has been faced by several mines, after the on-set of monsoon. A review of case studies available on the subject demonstrates that the ground displacement, stress redistribution, effect of ground water, low strength characteristics of the slope forming materials played significant role for the cause of slope failures. Slope monitoring studies indicated that the mechanism of slope failures could be complex and dependent on failure pathways, where certain units fail first and it is followed by subsequent failures due to redistribution of stresses from the preceding zone. The results of several observations, laboratory testing of slope forming materials and monitoring of the slopes have lead to an awareness of various mechanisms of failure and the conditions under which they occur. In real world situations, the failure mechanisms are much more complex involving many other variables due to complexity within the geological materials. The paper addressed the design of practical pit slope angles in such type of weak strata conditions. The testing techniques for material properties enable weak zones to be identified and their relative strengths are accurately determined. Case study of a large Iron mine discussed in detail to demonstrate how deep mining can be carried out under difficult ground conditions

    Searching via walking: How to find a marked subgraph of a graph using quantum walks

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    We show how a quantum walk can be used to find a marked edge or a marked complete subgraph of a complete graph. We employ a version of a quantum walk, the scattering walk, which lends itself to experimental implementation. The edges are marked by adding elements to them that impart a specific phase shift to the particle as it enters or leaves the edge. If the complete graph has N vertices and the subgraph has K vertices, the particle becomes localized on the subgraph in O(N/K) steps. This leads to a quantum search that is quadratically faster than a corresponding classical search. We show how to implement the quantum walk using a quantum circuit and a quantum oracle, which allows us to specify the resource needed for a quantitative comparison of the efficiency of classical and quantum searches -- the number of oracle calls.Comment: 4 pages, 2 figure

    Quantum search algorithms on a regular lattice

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    Quantum algorithms for searching one or more marked items on a d-dimensional lattice provide an extension of Grover's search algorithm including a spatial component. We demonstrate that these lattice search algorithms can be viewed in terms of the level dynamics near an avoided crossing of a one-parameter family of quantum random walks. We give approximations for both the level-splitting at the avoided crossing and the effectively two-dimensional subspace of the full Hilbert space spanning the level crossing. This makes it possible to give the leading order behaviour for the search time and the localisation probability in the limit of large lattice size including the leading order coefficients. For d=2 and d=3, these coefficients are calculated explicitly. Closed form expressions are given for higher dimensions

    A Survey and Evaluation of Edge Detection Operators: Application to Text Recognition

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    Edge detection, especially in image processing occupies a special position. How to accurately extract the edge information of object in images has been the hot research. One of the main objectives of image analysis is to extract the dominating information. Segmentation of image is defined as being major step in image processing that extracts and describes the presence of significant object in a scene, often in the form of region or edges. This paper describes several edge detection operators like Sobel, Prewitt, Canny, Roberts, Zero threshold and emergence of combination of different spatial edge detection method, and its matlab simulation studies and comparative analysis

    Combining ability analysis and gene action of grain quality traits in rice (Oryza sativa L.) using line × tester analysis

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    In rice, twelve lines were crossed with five testers in a line × tester mating design and the resultant 60 hybrids along with their parents were evaluated for their combining ability effects for 15 grain quality traits. The results revealed that the ratio of GCA: SCA variances computed for all the fifteen grain quality traits showed the predominance of non-additive gene action. Among the lines, ADT (R) 47 showed significant desirable gca effects at 1% probability level (p = 0.01) for 11 grain quality traits viz., hulling percentage, milling percentage, head rice recovery percentage, kernel breadth, kernel breadth after cooking, breadth wise expansion ratio, gelatinization temperature, amylose content, gel consistency, water uptake and volume expansion ratio. Among the testers, Pusa 1460 showed significant desirable gca effects at 1% probability level (p = 0.01) for 10 grain quality traits viz., kernel length, kernel breadth, kernel length/breadth ratio, kernel length after cooking, kernel breadth after cooking, linear elongation ratio, gelatinization temperature, amylose content, water uptake and volume expansion ratio and hence they were adjudged as the best combiners for the improvement of the respective traits. Among the hybrids, the hybrids CO 47/Imp., Samba Mahsuri, ADT (R) 47/IRBB 21 and ADT (R) 46/IRBB 21 were identified as best hybrids for exploitation of grain quality traits since they revealed significant sca effects at 1% probability level (p = 0.01) for eight, eight and five grain quality traits, respectively

    An analytical study – dynamic behavior of the human hand to hold mechanical handle with and without coating

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    The primary objective of the study is analytically predicting the anti-vibration coating on the handles and to evaluate the vibration isolation effectiveness. The ISO 10068:2012 two-point driving human physical models are coated with Foam-A material, Foam-B material, and Gel material. The coated ISO models are applied to predict the effectiveness of three different anti-vibrations coating in terms of vibration transmitted to the finger, palm, and the shoulder. The results are obtained as a vibration transmissibility magnitude in the three orthogonal directions (xh, yh, zh) and the results are also compared with uncoated models. A significant level of vibration reductions was found. The proposed model may also be useful for further analysis of anti-vibration coating materials and help designers to develop better handles for vibrating tools

    On the polynomial parity argument complexity of the combinatorial nullstellensatz

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    The complexity class PPA consists of NP-search problems which are reducible to the parity principle in undirected graphs. It contains a wide variety of interesting problems from graph theory, combinatorics, algebra and number theory, but only a few of these are known to be complete in the class. Before this work, the known complete problems were all discretizations or combinatorial analogues of topological fixed point theorems. Here we prove the PPA-completeness of two problems of radically different style. They are PPA-Circuit CNSS and PPA-Circuit Chevalley, related respectively to the Combinatorial Nullstellensatz and to the Chevalley-Warning Theorem over the two elements field GF(2). The input of these problems contain PPA-circuits which are arithmetic circuits with special symmetric properties that assure that the polynomials computed by them have always an even number of zeros. In the proof of the result we relate the multilinear degree of the polynomials to the parity of the maximal parse subcircuits that compute monomials with maximal multilinear degree, and we show that the maximal parse subcircuits of a PPA-circuit can be paired in polynomial time

    Single-qubit unitary gates by graph scattering

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    We consider the effects of plane-wave states scattering off finite graphs, as an approach to implementing single-qubit unitary operations within the continuous-time quantum walk framework of universal quantum computation. Four semi-infinite tails are attached at arbitrary points of a given graph, representing the input and output registers of a single qubit. For a range of momentum eigenstates, we enumerate all of the graphs with up to n=9n=9 vertices for which the scattering implements a single-qubit gate. As nn increases, the number of new unitary operations increases exponentially, and for n>6n>6 the majority correspond to rotations about axes distributed roughly uniformly across the Bloch sphere. Rotations by both rational and irrational multiples of π\pi are found.Comment: 8 pages, 7 figure

    On the complexity of trial and error for constraint satisfaction problems

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    In 2013 Bei, Chen and Zhang introduced a trial and error model of computing, and applied to some constraint satisfaction problems. In this model the input is hidden by an oracle which, for a candidate assignment, reveals some information about a violated constraint if the assignment is not satisfying. In this paper we initiate a systematic study of constraint satisfaction problems in the trial and error model, by adopting a formal framework for CSPs, and defining several types of revealing oracles. Our main contribution is to develop a transfer theorem for each type of the revealing oracle. To any hidden CSP with a specific type of revealing Oracle, the transfer theorem associates another CSP in the normal setting, such that their complexities are polynomial-time equivalent. This in principle transfers the study of a large class of hidden CSPs to the study of normal CSPs. We apply the transfer theorems to get polynomial-time algorithms or hardness results for several families of concrete problems. (C) 2017 Elsevier Inc. All rights reserved

    Impossibility of independence amplification in Kolmogorov complexity theory

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    The paper studies randomness extraction from sources with bounded independence and the issue of independence amplification of sources, using the framework of Kolmogorov complexity. The dependency of strings xx and yy is dep(x,y)=max{C(x)C(xy),C(y)C(yx)}{\rm dep}(x,y) = \max\{C(x) - C(x \mid y), C(y) - C(y\mid x)\}, where C()C(\cdot) denotes the Kolmogorov complexity. It is shown that there exists a computable Kolmogorov extractor ff such that, for any two nn-bit strings with complexity s(n)s(n) and dependency α(n)\alpha(n), it outputs a string of length s(n)s(n) with complexity s(n)α(n)s(n)- \alpha(n) conditioned by any one of the input strings. It is proven that the above are the optimal parameters a Kolmogorov extractor can achieve. It is shown that independence amplification cannot be effectively realized. Specifically, if (after excluding a trivial case) there exist computable functions f1f_1 and f2f_2 such that dep(f1(x,y),f2(x,y))β(n){\rm dep}(f_1(x,y), f_2(x,y)) \leq \beta(n) for all nn-bit strings xx and yy with dep(x,y)α(n){\rm dep}(x,y) \leq \alpha(n), then β(n)α(n)O(logn)\beta(n) \geq \alpha(n) - O(\log n)
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