scholarly journals New Algorithms for Bidirectional Singleton Arc Consistency

2013 ◽  
Vol 2013 ◽  
pp. 1-10
Author(s):  
Yonggang Zhang ◽  
Qian Yin ◽  
Xingjun Zhu ◽  
Zhanshan Li ◽  
Sibo Zhang ◽  
...  
Keyword(s):  
Time Complexity ◽  
The Other ◽  
Worst Case ◽  
Space And Time ◽  
Arc Consistency ◽  
Wide Range ◽  
Order Of Magnitude ◽  
Special Circumstances ◽  
New Algorithms

Bidirectional singleton arc consistency (BiSAC) which is an extended singleton arc consistency (SAC) has been proposed recently. The first contribution of this paper is to propose and prove two theorems of BiSAC theoretically (one is a property of BiSAC and the other is the property of allowing the deletion of some BiSAC-inconsistent values). Secondly, based on these properties we present two algorithms, denoted by BiSAC-DF and BiSAC-DP, to enforce BiSAC. Also, we prove their correctness and analyze the space and time complexity of them in detail. Besides, for special circumstances, we show that BiSAC-DF admits a worst-case time complexity inO(en2d4)and a best one inO(en2d3)when the problem is an already BiSAC, while BiSAC-DP also has the same best one when the tightness is small. Finally, experiments on a wide range of CSP instances show BiSAC-DF and BiSAC-DP are usually around one order of magnitude faster than the existing BiSAC-1. For some special instances, BiSAC-DP is about two orders of magnitude efficient.

FROM C-CONTINUATIONS TO NEW QUADRATIC ALGORITHMS FOR AUTOMATON SYNTHESIS

2001 ◽  
Vol 11 (06) ◽  
pp. 707-735 ◽  
Author(s):  
J.-M. CHAMPARNAUD ◽  
D. ZIADI
Keyword(s):  
Time Complexity ◽  
Regular Expression ◽  
Time Algorithm ◽  
The Other ◽  
Worst Case ◽  
Partial Derivatives ◽  
Space And Time ◽  
Other Hand ◽  
Deterministic Automata ◽  
The Way

Two classical non-deterministic automata recognize the language denoted by a regular expression: the position automaton which deduces from the position sets defined by Glushkov and McNaughton–Yamada, and the equation automaton which can be computed via Mirkin's prebases or Antimirov's partial derivatives. Let |E| be the size of the expression and ‖E‖ be its alphabetic width, i.e. the number of symbol occurrences. The number of states in the equation automaton is less than or equal to the number of states in the position automaton, which is equal to ‖E‖+1. On the other hand, the worst-case time complexity of Antimirov algorithm is O(‖E‖3· |E|2), while it is only O(‖E‖·|E|) for the most efficient implementations yielding the position automaton (Brüggemann–Klein, Chang and Paige, Champarnaud et al.). We present an O(|E|2) space and time algorithm to compute the equation automaton. It is based on the notion of canonical derivative which makes it possible to efficiently handle sets of word derivatives. By the way, canonical derivatives also lead to a new O(|E|2) space and time algorithm to construct the position automaton.

scholarly journals New Algorithms for δγ-Order Preserving Matching

Ingeniería ◽  
2018 ◽  
Vol 23 (2) ◽  
Author(s):  
Juan Mendivelso ◽  
Rafael Niquefa ◽  
Yoan Pinzón ◽  
Germán Hernández
Keyword(s):  
Lower Bound ◽  
Stock Market ◽  
Time Complexity ◽  
Stock Price ◽  
The Other ◽  
Relative Order ◽  
Worst Case ◽  
Music Retrieval ◽  
Price Trends ◽  
New Algorithms

Context: Order-preserving matching regards the relative order of strings. However, its application areas require more flexibility in the matching paradigm. We advance in this direction in this paper that extends our previous work [27].Method: We define γ -order preserving matching as an approximate variant of order-preserving matching. We devise two solutions for it based on segment and Fenwick trees: segtreeBA and bitBA.Results: We experimentally show the efficiency of our algorithms compared to the ones presented in [26] (naiveA and updateBA). Also, we present applications of our approach in music retrieval and stock market analysis.Conclusions: Even though the worst-case time complexity of the proposed algorithms (namely, O(nm log m)) is higher than the Ѳ(nm)-time complexity of updateBA, their Ω (n log n) lower bound makes them more efficient in practice. On the other hand, we show that our approach is useful to identify similarity in music melodies and stock price trends through real application examples.

scholarly journals Natural Science and Supernatural Thought Experiments

Religions ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 389
Author(s):  
James Robert Brown
Keyword(s):  
Natural Science ◽  
Thought Experiment ◽  
Thought Experiments ◽  
The Other ◽  
Space And Time ◽  
Wide Range ◽  
The Difference ◽  
Theological Thought

Religious notions have long played a role in epistemology. Theological thought experiments, in particular, have been effective in a wide range of situations in the sciences. Some of these are merely picturesque, others have been heuristically important, and still others, as I will argue, have played a role that could be called essential. I will illustrate the difference between heuristic and essential with two examples. One of these stems from the Newton–Leibniz debate over the nature of space and time; the other is a thought experiment of my own constructed with the aim of making a case for a more liberal view of evidence in mathematics.

scholarly journals Feature Recognition for Manufacturability Analysis

1994 ◽  
Author(s):  
William C. Regli ◽  
Satyandra K. Gupta ◽  
Dana S. Nau
Keyword(s):  
Time Complexity ◽  
Material Removal ◽  
Feature Recognition ◽  
Solid Modeling ◽  
Cad Model ◽  
Worst Case ◽  
Machining Features ◽  
Automated Recognition ◽  
Wide Range ◽  
Complete Set

Abstract While automated recognition of features has been attempted for a wide range of applications, no single existing approach possesses the functionality required to perform manufacturability analysis. In this paper, we present a methodology for taking a CAD model of a part and extracting a set of machinable features that contains the complete set of alternative interpretations of the part as collections of MRSEVs (Material Removal Shape Element Volumes, a STEP-based library of machining features). The approach handles a variety of features including those describing holes, pockets, slots, and chamfering and filleting operations. In addition, the approach considers accessibility constraints for these features, has an worst-case algorithmic time complexity quadratic in the number of solid modeling operations, and modifies features recognized to account for available tooling and produce more realistic volumes for manufacturability analysis.

scholarly journals Worst-case space and time complexity of recursive procedures

1996 ◽  
Vol 11 (2) ◽  
pp. 115-144 ◽  
Author(s):  
Johann Blieberger ◽  
Roland Lieger
Keyword(s):  
Time Complexity ◽  
Worst Case ◽  
Space And Time ◽  
Recursive Procedures

scholarly journals On Neighborhood Singleton Consistencies

2017 ◽  
Author(s):  
Anastasia Paparrizou ◽  
Kostas Stergiou
Keyword(s):  
Experimental Study ◽  
Simple Algorithm ◽  
The Other ◽  
Arc Consistency ◽  
Other Hand ◽  
Wide Range

CP solvers predominantly use arc consistency (AC) as the default propagation method. Many stronger consistencies, such as triangle consistencies (e.g. RPC and maxRPC) exist, but their use is limited despite results showing that they outperform AC on many problems. This is due to the intricacies involved in incorporating them into solvers. On the other hand, singleton consistencies such as SAC can be easily crafted into solvers but they are too expensive. We seek a balance between the efficiency of triangle consistencies and the ease of implementation of singleton ones. Using the recently proposed variant of SAC called Neighborhood SAC as basis, we propose a family of weaker singleton consistencies. We study them theoretically, comparing their pruning power to existing consistencies. We make a detailed experimental study using a very simple algorithm for their implementation. Results demonstrate that they outperform the existing propagation techniques, often by orders of magnitude, on a wide range of problems.

scholarly journals Lyndon Factorization Algorithms for Small Alphabets and Run-Length Encoded Strings

Algorithms ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 124
Author(s):  
Sukhpal Ghuman ◽  
Emanuele Giaquinta ◽  
Jorma Tarhio
Keyword(s):  
Time Complexity ◽  
Linear Time ◽  
Experimental Results ◽  
The Other ◽  
Worst Case ◽  
Run Length ◽  
Original Algorithm ◽  
Factorization Algorithms

We present two modifications of Duval’s algorithm for computing the Lyndon factorization of a string. One of the algorithms has been designed for strings containing runs of the smallest character. It works best for small alphabets and it is able to skip a significant number of characters of the string. Moreover, it can be engineered to have linear time complexity in the worst case. When there is a run-length encoded string R of length ρ , the other algorithm computes the Lyndon factorization of R in O ( ρ ) time and in constant space. It is shown by experimental results that the new variations are faster than Duval’s original algorithm in many scenarios.

Asymmetrically Plate-Reinforced Circular Hole in a Uniformly End-Loaded Flat Plate

1959 ◽  
Vol 10 (2) ◽  
pp. 183-198 ◽  
Author(s):  
Raymond Hicks
Keyword(s):  
Flat Plate ◽  
Circular Hole ◽  
Annular Plate ◽  
The Other ◽  
Stress Distributions ◽  
Stress Concentrations ◽  
Principal Stresses ◽  
Wide Range ◽  
Bending Stresses ◽  
Order Of Magnitude

SummaryGeneral expressions are obtained for the stress distribution in a flat plate end-loaded by equal principal stresses and containing a circular hole reinforced by an annular plate. The reinforcement is placed on one side of the plate only so that the other side remains flush. It is shown that the effect of an asymmetrically placed reinforcement is to induce, in the plate and rein-forcement, bending stresses which are not negligible compared with the externally applied direct stress. From particular examples it is found that reinforcements having practical dimensions can give rise to stress concentrations in the same order of magnitude as those in a similarly loaded plate containing an unreinforced hole. For practical purposes, data have been obtained which enable the designer to determine quickly the stress distributions associated with reinforcements and plates having a reasonably wide range of dimensions.

The uptake of nitrogen from soils in relation to solute diffusion

Soil Research ◽  
1968 ◽  
Vol 6 (1) ◽  
pp. 75 ◽  
Author(s):  
AL Clarke ◽  
KP Barley
Keyword(s):  
Thin Layer ◽  
Nitrogen Uptake ◽  
Nitrate Uptake ◽  
Nitrate Nitrogen ◽  
Solution Concentration ◽  
The Other ◽  
Solute Diffusion ◽  
Wheat Roots ◽  
Wide Range ◽  
Order Of Magnitude

When either a sand or a loam was wetted with solutions of given concentration, the apparent diffusivities of nitrate, KNO3, and ammonium, KNH3, increased with the volume of solution added. Values of KNO3 (0.5-5 x 10-3 cm2/sec) were similar to those reported previously for KCl, and were one order of magnitude higher than the values for KNH4 (0.4-3 x 10-7 cm2/sec). The rate at which wheat roots depleted the sand and loam of nitrate or ammonium was measured by two methods. In one method root mats were used, and in the other single roots were grown through a thin layer of soil. In both methods the flow of water to the roots was minimized. The uptake of nitrogen followed a very different pattern from that reported for stirred solutions. Nitrate uptake increased linearly with soil solution concentration over a wide range, 100-1000 p.p.m. of nitrate nitrogen. Also, although ammonium is generally absorbed more rapidly than nitrate from stirred solutions, nitrate was absorbed far more rapidly than ammonium when equivalent amounts were added to the soil. The observed variations in nitrogen uptake could be largely attributed to changes in the resistance that the soil offered to the diffusion of solutes.

2D Color-Intensity Representation of Ultrasonic Thickness Gauge Measurements

2020 ◽  
pp. 1192-1198
Author(s):  
M.S. Mohammad ◽  
Tibebe Tesfaye ◽  
Kim Ki-Seong
Keyword(s):  
Cost Effective ◽  
The Other ◽  
Thickness Gauge ◽  
Color Intensity ◽  
Digital Readout ◽  
Flat Surfaces ◽  
Video Cameras ◽  
Wide Range ◽  
Cost Effective Alternative ◽  
Ultrasonic Thickness

Ultrasonic thickness gauges are easy to operate and reliable, and can be used to measure a wide range of thicknesses and inspect all engineering materials. Supplementing the simple ultrasonic thickness gauges that present results in either a digital readout or as an A-scan with systems that enable correlating the measured values to their positions on the inspected surface to produce a two-dimensional (2D) thickness representation can extend their benefits and provide a cost-effective alternative to expensive advanced C-scan machines. In previous work, the authors introduced a system for the positioning and mapping of the values measured by the ultrasonic thickness gauges and flaw detectors (Tesfaye et al. 2019). The system is an alternative to the systems that use mechanical scanners, encoders, and sophisticated UT machines. It used a camera to record the probe’s movement and a projected laser grid obtained by a laser pattern generator to locate the probe on the inspected surface. In this paper, a novel system is proposed to be applied to flat surfaces, in addition to overcoming the other limitations posed due to the use of the laser projection. The proposed system uses two video cameras, one to monitor the probe’s movement on the inspected surface and the other to capture the corresponding digital readout of the thickness gauge. The acquired images of the probe’s position and thickness gauge readout are processed to plot the measured data in a 2D color-coded map. The system is meant to be simpler and more effective than the previous development.

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