Circularly permuted monomeric red fluorescent proteins with new termini in the beta-sheet.
Carlson, Haley J; Cotton, Darrel W; Campbell, Robert E
2010-08-01
Circularly permuted fluorescent proteins (FPs) have a growing number of uses in live cell fluorescence biosensing applications. Most notably, they enable the construction of single fluorescent protein-based biosensors for Ca(2+) and other analytes of interest. Circularly permuted FPs are also of great utility in the optimization of fluorescence resonance energy transfer (FRET)-based biosensors by providing a means for varying the critical dipole-dipole orientation. We have previously reported on our efforts to create circularly permuted variants of a monomeric red FP (RFP) known as mCherry. In our previous work, we had identified six distinct locations within mCherry that tolerated the insertion of a short peptide sequence. Creation of circularly permuted variants with new termini at the locations corresponding to the sites of insertion led to the discovery of three permuted variants that retained no more than 18% of the brightness of mCherry. We now report the extensive directed evolution of the variant with new termini at position 193 of the protein sequence for improved fluorescent brightness. The resulting variant, known as cp193g7, has 61% of the intrinsic brightness of mCherry and was found to be highly tolerant of circular permutation at other locations within the sequence. We have exploited this property to engineer an expanded series of circularly permuted variants with new termini located along the length of the 10th beta-strand of mCherry. These new variants may ultimately prove useful for the creation of single FP-based Ca(2+) biosensors. PMID:20521333
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We investigated the mechanical unfolding of single circularly permuted green fluorescent protein (cpGFP) with atomic force microscopy (AFM). The molecule was stretched from its N- and C-termini by an external force causing an elongation of the polypeptide chain up to its full length. The features of the force-extension (F-E) curves were found to depend on the stretching speed. At fast speeds, we detected one peak in the F-E curves before final rupture of the extended molecule, which we interpreted as the unfolding of two terminal halves within cpGFP. We observed several more force peaks in a sawtooth pattern at much slower speeds, and explained the appearance of such force peaks as cooperative unfolding of the hidden sub-structures inside each terminal half
A Versatile Platform for Nanotechnology Based on Circular Permutation of a Chaperonin Protein
Paavola, Chad; McMillan, Andrew; Trent, Jonathan; Chan, Suzanne; Mazzarella, Kellen; Li, Yi-Fen
2004-01-01
A number of protein complexes have been developed as nanoscale templates. These templates can be functionalized using the peptide sequences that bind inorganic materials. However, it is difficult to integrate peptides into a specific position within a protein template. Integrating intact proteins with desirable binding or catalytic activities is an even greater challenge. We present a general method for modifying protein templates using circular permutation so that additional peptide sequence can be added in a wide variety of specific locations. Circular permutation is a reordering of the polypeptide chain such that the original termini are joined and new termini are created elsewhere in the protein. New sequence can be joined to the protein termini without perturbing the protein structure and with minimal limitation on the size and conformation of the added sequence. We have used this approach to modify a chaperonin protein template, placing termini at five different locations distributed across the surface of the protein complex. These permutants are competent to form the double-ring structures typical of chaperonin proteins. The permuted double-rings also form the same assemblies as the unmodified protein. We fused a fluorescent protein to two representative permutants and demonstrated that it assumes its active structure and does not interfere with assembly of chaperonin double-rings.
High-resolution structure prediction of a circular permutation loop
Correia, Bruno E.; Holmes, Margaret A.; Huang, Po-Ssu; Strong, Roland K.; Schief, William R.
2011-01-01
Methods for rapid and reliable design and structure prediction of linker loops would facilitate a variety of protein engineering applications. Circular permutation, in which the existing termini of a protein are linked by the polypeptide chain and new termini are created, is one such application that has been employed for decreasing proteolytic susceptibility and other functional purposes. The length and sequence of the linker can impact the expression level, solubility, structure and functio...
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Decompositions into cycles for random permutations of a large number of elements are very different (in their statistics) from the same decompositions for algebraic permutations (defined by linear or projective transformations of finite sets). This paper presents tables giving both these and other statistics, as well as a comparison of them with the statistics of involutions or permutations with all their cycles of even length. The inclusions of a point in cycles of various lengths turn out to be equiprobable events for random permutations. The number of permutations of 2N elements with all cycles of even length turns out to be the square of an integer (namely, of (2N-1)!!). The number of cycles of projective permutations (over a field with an odd prime number of elements) is always even. These and other empirically discovered theorems are proved in the paper. Bibliography: 6 titles.
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Arnold, Vladimir I [Steklov Mathematical Institute, Russian Academy of Sciences, Moscow (Russian Federation)
2009-08-31
Decompositions into cycles for random permutations of a large number of elements are very different (in their statistics) from the same decompositions for algebraic permutations (defined by linear or projective transformations of finite sets). This paper presents tables giving both these and other statistics, as well as a comparison of them with the statistics of involutions or permutations with all their cycles of even length. The inclusions of a point in cycles of various lengths turn out to be equiprobable events for random permutations. The number of permutations of 2N elements with all cycles of even length turns out to be the square of an integer (namely, of (2N-1){exclamation_point}{exclamation_point}). The number of cycles of projective permutations (over a field with an odd prime number of elements) is always even. These and other empirically discovered theorems are proved in the paper. Bibliography: 6 titles.
Circular Permutation of a Chaperonin Protein: Biophysics and Application to Nanotechnology
Paavola, Chad; Chan, Suzanne; Li, Yi-Fen; McMillan, R. Andrew; Trent, Jonathan
2004-01-01
We have designed five circular permutants of a chaperonin protein derived from the hyperthermophilic organism Sulfolobus shibatae. These permuted proteins were expressed in E. coli and are well-folded. Furthermore, all the permutants assemble into 18-mer double rings of the same form as the wild-type protein. We characterized the thermodynamics of folding for each permutant by both guanidine denaturation and differential scanning calorimetry. We also examined the assembly of chaperonin rings into higher order structures that may be used as nanoscale templates. The results show that circular permutation can be used to tune the thermodynamic properties of a protein template as well as facilitating the fusion of peptides, binding proteins or enzymes onto nanostructured templates.
Efficiently folding and circularly permuted variants of the Sapphire mutant of GFP
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Griesbeck Oliver
2003-05-01
Full Text Available Abstract Background The green fluorescent protein (GFP has been widely used in cell biology as a marker of gene expression, label of cellular structures, fusion tag or as a crucial constituent of genetically encoded biosensors. Mutagenesis of the wildtype gene has yielded a number of improved variants such as EGFP or colour variants suitable for fluorescence resonance energy transfer (FRET. However, folding of some of these mutants is still a problem when targeted to certain organelles or fused to other proteins. Results By directed rational mutagenesis, we have produced a new variant of the Sapphire mutant of GFP with improved folding properties that turns out to be especially beneficial when expressed within organelles or as a fusion tag. Its absorption spectrum is pH-stable and the pKa of its emission is 4.9, making it very resistant to pH perturbation inside cells. Conclusion "T-Sapphire" and its circular permutations can be used as labels of proteins or cellular structures and as FRET donors in combination with red-fluorescent acceptor proteins such as DsRed, making it possible to completely separate donor and acceptor excitation and emission in intensity-based FRET experiments.
Mefford, Melissa A; Zappulla, David C
2015-01-01
Telomerase is a specialized ribonucleoprotein complex that extends the 3' ends of chromosomes to counteract telomere shortening. However, increased telomerase activity is associated with ∼90% of human cancers. The telomerase enzyme minimally requires an RNA (hTR) and a specialized reverse transcriptase protein (TERT) for activity in vitro. Understanding the structure-function relationships within hTR has important implications for human disease. For the first time, we have tested the physical-connectivity requirements in the 451-nucleotide hTR RNA using circular permutations, which reposition the 5' and 3' ends. Our extensive in vitro analysis identified three classes of hTR circular permutants with altered function. First, circularly permuting 3' of the template causes specific defects in repeat-addition processivity, revealing that the template recognition element found in ciliates is conserved in human telomerase RNA. Second, seven circular permutations residing within the catalytically important core and CR4/5 domains completely abolish telomerase activity, unveiling mechanistically critical portions of these domains. Third, several circular permutations between the core and CR4/5 significantly increase telomerase activity. Our extensive circular permutation results provide insights into the architecture and coordination of human telomerase RNA and highlight where the RNA could be targeted for the development of antiaging and anticancer therapeutics. PMID:26503788
Using circular permutation analysis to redefine the R17 coat protein binding site.
Gott, J M; Pan, T; LeCuyer, K A; Uhlenbeck, O C
1993-12-14
The bacteriophage R17 coat protein binding site consists of an RNA hairpin with a single purine nucleotide bulge in the helical stem. Circular permutation analysis (CPA) was used to examine binding effects caused by a single break in the phosphodiester backbone. This method revealed that breakage of all but one phosphodiester bond within a well-defined binding site substantially reduced the binding affinity. This is probably due to destabilization of the hairpin structure upon breaking the ribose phosphates at these positions. One circularly permuted isomer with the 5' and 3' ends at the bulged nucleotide bound with wild-type affinity. However, extending the 5' end of this CP isomer greatly reduces binding, making it unlikely that this circularly permuted binding site will be active when embedded in a larger RNA. CPA also locates the 5' and 3' boundaries of protein binding sites on the RNA. The 5' boundary of the R17 coat protein site as defined by CPA was two nucleotides shorter (nucleotides -15 to +2) than the previously determined site (-17 to +2). The smaller binding site was verified by terminal truncation experiments. A minimal-binding fragment (-14 to +2) was synthesized and was found to bind tightly to the coat protein. The site size determined by 3-ethyl-1-nitrosourea-modification interference was larger at the 5' end (-16 to +1), probably due, however, to steric effects of ethylation of phosphate oxygens. Thus, the apparent site size of a protein binding site is dependent upon the method used. PMID:7504949
Structural consequences of cutting a binding loop: two circularly permuted variants of streptavidin
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The crystal structures of two circularly permuted streptavidins probe the role of a flexible loop in the tight binding of biotin. Molecular-dynamics calculations for one of the mutants suggests that increased fluctuations in a hydrogen bond between the protein and biotin are associated with cleavage of the binding loop. Circular permutation of streptavidin was carried out in order to investigate the role of a main-chain amide in stabilizing the high-affinity complex of the protein and biotin. Mutant proteins CP49/48 and CP50/49 were constructed to place new N-termini at residues 49 and 50 in a flexible loop involved in stabilizing the biotin complex. Crystal structures of the two mutants show that half of each loop closes over the binding site, as observed in wild-type streptavidin, while the other half adopts the open conformation found in the unliganded state. The structures are consistent with kinetic and thermodynamic data and indicate that the loop plays a role in enthalpic stabilization of the bound state via the Asn49 amide–biotin hydrogen bond. In wild-type streptavidin, the entropic penalties of immobilizing a flexible portion of the protein to enhance binding are kept to a manageable level by using a contiguous loop of medium length (six residues) which is already constrained by its anchorage to strands of the β-barrel protein. A molecular-dynamics simulation for CP50/49 shows that cleavage of the binding loop results in increased structural fluctuations for Ser45 and that these fluctuations destabilize the streptavidin–biotin complex
Structural consequences of cutting a binding loop: two circularly permuted variants of streptavidin
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Le Trong, Isolde [University of Washington, Box 357420, Seattle, WA 98195-7420 (United States); University of Washington, Box 357742, Seattle, WA 98195-7742 (United States); Chu, Vano [University of Washington, Box 355061, Seattle, WA 98195-5061 (United States); Xing, Yi [University of Washington, Box 357420, Seattle, WA 98195-7420 (United States); Lybrand, Terry P. [Vanderbilt University, 5142 Medical Research Building III, 465 21st Avenue South, Nashville, TN 37232-8725 (United States); Stayton, Patrick S. [University of Washington, Box 355061, Seattle, WA 98195-5061 (United States); Stenkamp, Ronald E., E-mail: stenkamp@u.washington.edu [University of Washington, Box 357420, Seattle, WA 98195-7420 (United States); University of Washington, Box 357742, Seattle, WA 98195-7742 (United States); University of Washington, Box 357430, Seattle, WA 98195-7430 (United States)
2013-06-01
The crystal structures of two circularly permuted streptavidins probe the role of a flexible loop in the tight binding of biotin. Molecular-dynamics calculations for one of the mutants suggests that increased fluctuations in a hydrogen bond between the protein and biotin are associated with cleavage of the binding loop. Circular permutation of streptavidin was carried out in order to investigate the role of a main-chain amide in stabilizing the high-affinity complex of the protein and biotin. Mutant proteins CP49/48 and CP50/49 were constructed to place new N-termini at residues 49 and 50 in a flexible loop involved in stabilizing the biotin complex. Crystal structures of the two mutants show that half of each loop closes over the binding site, as observed in wild-type streptavidin, while the other half adopts the open conformation found in the unliganded state. The structures are consistent with kinetic and thermodynamic data and indicate that the loop plays a role in enthalpic stabilization of the bound state via the Asn49 amide–biotin hydrogen bond. In wild-type streptavidin, the entropic penalties of immobilizing a flexible portion of the protein to enhance binding are kept to a manageable level by using a contiguous loop of medium length (six residues) which is already constrained by its anchorage to strands of the β-barrel protein. A molecular-dynamics simulation for CP50/49 shows that cleavage of the binding loop results in increased structural fluctuations for Ser45 and that these fluctuations destabilize the streptavidin–biotin complex.
Crystal Structure of Circular Permuted RoCBM21 (CP90): Dimerisation and Proximity of Binding Sites
Stephen, Preyesh; Cheng, Kuo-Chang; Lyu, Ping-Chiang
2012-01-01
Glucoamylases, containing starch-binding domains (SBD), have a wide range of scientific and industrial applications. Random mutagenesis and DNA shuffling of the gene encoding a starch-binding domain have resulted in only minor improvements in the affinities of the corresponding protein to their ligands, whereas circular permutation of the RoCBM21 substantially improved its binding affinity and selectivity towards longer-chain carbohydrates. For the study reported herein, we used a standard so...
Online inspection of circular fluorescent lamp
Ang, Beng-Hoe
1998-10-01
One step in the manufacture of circular fluorescent lamps is the mercury (Hg) injection process in which a small amount of mercury approximately 20 mg is injected into the fluorescent tube. An on-line detection of mercury is required to ensure that the amount of mercury residual inside the tube is within the acceptable tolerance. This critical operation is to reduce manufacturing overhead by controlling cost and reducing waste of materials. In view of this, an attempt has been made to design and develop an on- line mercury detection system with important benefits to the manufacturers, such as increased throughput, accuracy, reliability and consistency. This paper presents the configuration and development works of the on-line circular fluorescent lamp inspection system developed by Industrial Project Group--Machine Vision Center of Nanyang Polytechnic. The inspection system performs on-line detection of mercury particles (Hg) inside the circular fluorescent lamp. Taking the orientation and translation offsets of the lamp into consideration, it detects the presence/absence as well as the size of the injected mercury. The system has been successfully operating 15 hours per day and inspecting more than 22 thousands lamps in the production plant.
SIMULTANEOUS MEASUREMENT OF CIRCULAR DICHROISM AND FLUORESCENCE POLARIZATION ANISOTROPY.
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SUTHERLAND,J.C.
2002-01-19
Circular dichroism and fluorescence polarization anisotropy are important tools for characterizing biomolecular systems. Both are used extensively in kinetic experiments involving stopped- or continuous flow systems as well as titrations and steady-state spectroscopy. This paper presents the theory for determining circular dichroism and fluorescence polarization anisotropy simultaneously, thus insuring the two parameters are recorded under exactly the same conditions and at exactly the same time in kinetic experiments. The approach to measuring circular dichroism is that used in almost all conventional dichrographs. Two arrangements for measuring fluorescence polarization anisotropy are described. One uses a single fluorescence detector and signal processing with a lock-in amplifier that is similar to the measurement of circular dichroism. The second approach uses classic ''T'' format detection optics, and thus can be used with conventional photon-counting detection electronics. Simple extensions permit the simultaneous measurement of the absorption and excitation intensity corrected fluorescence intensity.
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Xu, Qingping; Rawlings, Neil D.; Chiu, Hsiu-Ju; Jaroszewski, Lukasz; Klock, Heath E.; Knuth, Mark W.; Miller, Mitchell D.; Elsliger, Marc-Andre; Deacon, Ashley M.; Godzik, Adam; Lesley, Scott A.; Wilson, Ian A. (SG); (Wellcome)
2012-07-11
NlpC/P60 superfamily papain-like enzymes play important roles in all kingdoms of life. Two members of this superfamily, LRAT-like and YaeF/YiiX-like families, were predicted to contain a catalytic domain that is circularly permuted such that the catalytic cysteine is located near the C-terminus, instead of at the N-terminus. These permuted enzymes are widespread in virus, pathogenic bacteria, and eukaryotes. We determined the crystal structure of a member of the YaeF/YiiX-like family from Bacillus cereus in complex with lysine. The structure, which adopts a ligand-induced, 'closed' conformation, confirms the circular permutation of catalytic residues. A comparative analysis of other related protein structures within the NlpC/P60 superfamily is presented. Permutated NlpC/P60 enzymes contain a similar conserved core and arrangement of catalytic residues, including a Cys/His-containing triad and an additional conserved tyrosine. More surprisingly, permuted enzymes have a hydrophobic S1 binding pocket that is distinct from previously characterized enzymes in the family, indicative of novel substrate specificity. Further analysis of a structural homolog, YiiX (PDB 2if6) identified a fatty acid in the conserved hydrophobic pocket, thus providing additional insights into possible function of these novel enzymes.
Ericson, Thomas
1993-01-01
Slepians permutation codes are investigated in detail. In particular we optimize the initial vector and derive all dominating codes in dimension n 2 6. With the exception of the simplex and biorthogonal codes - which are always included as special cases of permutation codes - there are probably no further good codes in higher dimensions.
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N-fold tensor products of a rational CFT carry an action of the permutation group SN. These automorphisms can be used as gluing conditions in the study of boundary conditions for tensor product theories. We present an ansatz for such permutation boundary states and check that it satisfies the cluster condition and Cardy's constraints. For a particularly simple case, we also investigate associativity of the boundary OPE, and find an intriguing connection with the bulk OPE. In the second part of the paper, the constructions are slightly extended for application to Gepner models. We give permutation branes for the quintic, together with some formulae for their intersections. (author)
Gillespie, Neil I.; Praeger, Cheryl E.; Spiga, Pablo
2014-01-01
We introduce twisted permutation codes, which are frequency permutation arrays analogous to repetition permutation codes, namely, codes obtained from the repetition construction applied to a permutation code. In particular, we show that a lower bound for the minimum distance of a twisted permutation code is the minimum distance of a repetition permutation code. We give examples where this bound is tight, but more importantly, we give examples of twisted permutation codes with minimum distance...
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A general theory of permutation orbifolds is developed for arbitrary twist groups. Explicit expressions for the number of primaries, the partition function, the genus one characters, the matrix elements of modular transformations and for fusion rule coefficients are presented, together with the relevant mathematical concepts, such as Λ-matrices and twisted dimensions. The arithmetic restrictions implied by the theory for the allowed modular representations in CFT are discussed. The simplest nonabelian example with twist group S3 is described to illustrate the general theory
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We consider orientifold actions involving the permutation of two identical factor theories. The corresponding crosscap states are constructed in rational conformal field theory. We study group manifolds, in particular the examples SU(2) x SU(2) and U(1) x U(1) in detail, comparing conformal field theory results with geometry. We then consider orientifolds of tensor products of N = 2 minimal models, which have a description as coset theories in rational conformal field theory and as Landau Ginzburg models. In the Landau Ginzburg language, B-orientifolds and D-branes are described in terms of matrix factorizations of the superpotential. We match the factorizations with the corresponding crosscap states
Passman, Donald S
2012-01-01
This volume by a prominent authority on permutation groups consists of lecture notes that provide a self-contained account of distinct classification theorems. A ready source of frequently quoted but usually inaccessible theorems, it is ideally suited for professional group theorists as well as students with a solid background in modern algebra.The three-part treatment begins with an introductory chapter and advances to an economical development of the tools of basic group theory, including group extensions, transfer theorems, and group representations and characters. The final chapter feature
Bántay, P
2002-01-01
A general theory of permutation orbifolds is developed for arbitrary twist groups. Explicit expressions for the number of primaries, the partition function, the genus one characters, the matrix elements of modular transformations and for fusion rule coefficients are presented, together with the relevant mathematical concepts, such as Lambda-matrices and twisted dimensions. The arithmetic restrictions implied by the theory for the allowed modular representations in CFT are discussed. The simplest nonabelian example with twist group S_3 is described to illustrate the general theory.
Gabrys, Ryan; Milenkovic, Olgica
2016-01-01
Motivated by charge balancing constraints for rank modulation schemes, we introduce the notion of balanced permutations and derive the capacity of balanced permutation codes. We also describe simple interleaving methods for permutation code constructions and show that they approach capacity
Baumeister, Barbara; Haase, Christian; Nill, Benjamin; Paffenholz, Andreas
2007-01-01
A permutation polytope is the convex hull of a group of permutation matrices. In this paper we investigate the combinatorics of permutation polytopes and their faces. As applications we completely classify permutation polytopes in dimensions 2,3,4, and the corresponding permutation groups up to a suitable notion of equivalence. We also provide a list of combinatorial types of possibly occuring faces of permutation polytopes up to dimension four.
Rigbi, Meir; Rosinski, Joanne; Siegelman, Harold W.; Sutherland, John Clark
1980-01-01
Phycobilisomes are supramolecular assemblies of phycobiliproteins responsible for photosynthetic light collection in red algae and cyanobacteria. They can be selectively dissociated by reduction of temperature and buffer concentration. Phycobilisomes isolated from Fremyella diplosiphon transfer energy collected by C-phycoerythrin and C-phycocyanin to allophycocyanin. The energy transfer to allophycocyanin is nearly abolished at 2°C, as indicated by a blue shift in fluorescence emission, and i...
Bhatia, Swapnil; LaBoda, Craig; Yanez, Vanessa; Haddock-Angelli, Traci; Densmore, Douglas
2016-08-19
We define a new inversion-based machine called a permuton of n genetic elements, which allows the n elements to be rearranged in any of the n·(n - 1)·(n - 2)···2 = n! distinct orderings. We present two design algorithms for architecting such a machine. We define a notion of a feasible design and use the framework to discuss the feasibility of the permuton architectures. We have implemented our design algorithms in a freely usable web-accessible software for exploration of these machines. Permutation machines could be used as memory elements or state machines and explicitly illustrate a rational approach to designing biological systems. PMID:27383067
Construction of Permutation Snarks
Hägglund, Jonas; Hoffmann-Ostenhof, Arthur
2012-01-01
A permutation snark is a snark which has a 2-factor $F_2$ consisting of two chordless circuits; $F_2$ is called the permutation 2-factor of $G$. We construct an infinite family $\\mathcal H$ of cyclically 5-edge connected permutation snarks. Moreover, we prove for every member $G \\in \\mathcal H$ that the permutation 2-factor given by the construction of $G$ is not contained in any circuit double cover of $G$.
Graphical Cyclic Permutation Groups
Grech, Mariusz
2012-01-01
We establish conditions for a permutation group generated by a single permutation of a prime power order to be an automorphism group of a graph or an edge-colored graph. This corrects and generalizes the results of the two papers on cyclic permutation groups published in 1978 and 1981 by S. P. Mohanty, M. R. Sridharan, and S. K. Shukla.
Bona, Miklos
2012-01-01
A Unified Account of Permutations in Modern Combinatorics A 2006 CHOICE Outstanding Academic Title, the first edition of this bestseller was lauded for its detailed yet engaging treatment of permutations. Providing more than enough material for a one-semester course, Combinatorics of Permutations, Second Edition continues to clearly show the usefulness of this subject for both students and researchers. Expanded Chapters Much of the book has been significantly revised and extended. This edition includes a new section on alternating permutations and new material on multivariate applications of t
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We give a brief review of recent work on rational boundary states associated with gluing automorphisms from the permutation group. We sketch how the construction can be extended to Gepner models and show that there is a D0-brane among the permutation branes on the quintic. (Abstract Copyright [2003], Wiley Periodicals, Inc.)
Key Based Random Permutation (KBRP)
Shakir M. Hussain; Naim M. Ajlouni
2006-01-01
This study introduces a method for generating a particular permutation P of a given size N out of N! permutations from a given key. This method computes a unique permutation for a specific size since it takes the same key; therefore, the same permutation can be computed each time the same key and size are applied. The name of random permutation comes from the fact that the probability of getting this permutation is 1 out of N! possible permutations. Beside that, the permutation can not be gue...
Entangling power of permutations
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The notion of entangling power of unitary matrices was introduced by Zanardi et al., [Phys. Rev. A 62, 030301 (2000)]. We study the entangling power of permutations, given in terms of a combinatorial formula. We show that the permutation matrices with zero entangling power are, up to local unitaries, the identity and the swap. We construct the permutations with the minimum nonzero entangling power for every dimension. With the use of orthogonal latin squares, we construct the permutations with the maximum entangling power for every dimension. Moreover, we show that the value obtained is maximum over all unitaries of the same dimension, with a possible exception for 36. Our result enables us to construct generic examples of 4-qudit maximally entangled states for all dimensions except for 2 and 6. We numerically classify, according to their entangling power, the permutation matrices of dimensions 4 and 9, and we give some estimates for higher dimensions
Permutation codes for sources.
Berger, T.; Jelinek, F.; Wolf, J. K.
1972-01-01
Source encoding techniques based on permutation codes are investigated. For a broad class of distortion measures it is shown that optimum encoding of a source permutation code is easy to instrument even for very long block lengths. Also, the nonparametric nature of permutation encoding is well suited to situations involving unknown source statistics. For the squared-error distortion measure a procedure for generating good permutation codes of a given rate and block length is described. The performance of such codes for a memoryless Gaussian source is compared both with the rate-distortion function bound and with the performance of various quantization schemes. The comparison reveals that permutation codes are asymptotically ideal for small rates and perform as well as the best entropy-coded quantizers presently known for intermediate rates. They can be made to compare favorably at high rates, too, provided the coding delay associated with extremely long block lengths is tolerable.
Recchia, Gabriel; Sahlgren, Magnus; Kanerva, Pentti; Jones, Michael N
2015-01-01
Circular convolution and random permutation have each been proposed as neurally plausible binding operators capable of encoding sequential information in semantic memory. We perform several controlled comparisons of circular convolution and random permutation as means of encoding paired associates as well as encoding sequential information. Random permutations outperformed convolution with respect to the number of paired associates that can be reliably stored in a single memory trace. Performance was equal on semantic tasks when using a small corpus, but random permutations were ultimately capable of achieving superior performance due to their higher scalability to large corpora. Finally, "noisy" permutations in which units are mapped to other units arbitrarily (no one-to-one mapping) perform nearly as well as true permutations. These findings increase the neurological plausibility of random permutations and highlight their utility in vector space models of semantics. PMID:25954306
Circular dichroism and polarized fluorescence characteristics of blue-green algal allophycocyanins
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Canaani, O.D.; Gantt, E.
1980-06-24
Allophycocyanin, the terminal pigment in the phycobiliprotein transfer sequence, isolated from dissociated phycobilisomes of Nostoc sp., was fractionated on calcium phosphate columns into four spectral forms: APC I, II, III, and B. These forms had distinctive isoelectric points of 5.15, 4.68, 4.82, and 4.98, respectively. The APC forms differed in their secondary structure as suggested by the varying percentages of their ..cap alpha.. helix and ..beta..-pleated sheets. APC II and III are short-emitting forms with a fluorescence maximum at 660 nm, while APC I and B are long-emitting forms with a maximum at 681 nm. The maximum of APC I and B at -196/sup 0/C in 0.1 M phosphate and 20% glycerol shifted to 688 nm. Fluorescence polarization spectra suggest that there are at least two groups of chromophores responsible for the absorption of APC I and similarly of APC B. In APC II and III, the fluorescence was mostly depolarized. Circular dichroism revealed extensive positive and negative ellipticity band multiplicities in the chromophore absorption region of APC I and B, but not in APC II and III. Two main CD extrema in APC B, a negative band and a positive band, are probably the result of exciton coupling of phycocyanobilin chromophores absorbing at longer wavelength. In APC I three different peaks are revealed in the absorption spectrum and four ellipticity bands in the CD spectrum at -196/sup 0/C. These can best be explained as being due to the combined interactions of the chromophore with the protein and exciton coupling between chromophores.
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Mikel Aickin
2010-01-01
Full Text Available Permutation tests are often presented in a rather casual manner, in both introductory and advanced statistics textbooks. The appeal of the cleverness of the procedure seems to replace the need for a rigorous argument that it produces valid hypothesis tests. The consequence of this educational failing has been a widespread belief in a “permutation principle”, which is supposed invariably to give tests that are valid by construction, under an absolute minimum of statistical assumptions. Several lines of argument are presented here to show that the permutation principle itself can be invalid, concentrating on the Fisher-Pitman permutation test for two means. A simple counterfactual example illustrates the general problem, and a slightly more elaborate counterfactual argument is used to explain why the main mathematical proof of the validity of permutation tests is mistaken. Two modifications of the permutation test are suggested to be valid in a very modest simulation. In instances where simulation software is readily available, investigating the validity of a specific permutation test can be done easily, requiring only a minimum understanding of statistical technicalities.
Quantum sign permutation polytopes
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Convex polytopes are convex hulls of point sets in the n-dimensional space En that generalize two-dimensional convex polygons and three-dimensional convex polyhedra. We concentrate on the class of n-dimensional polytopes in En called sign permutation polytopes. We characterize sign permutation polytopes before relating their construction to constructions over the space of quantum density matrices. Finally, we consider the problem of state identification and show how sign permutation polytopes may be useful in addressing issues of robustness.
Bona, Miklos
2004-01-01
WINNER of a CHOICE Outstanding Academic Title Award for 2006!As linear orders, as elements of the symmetric group, modeled by matrices, modeled by graphs…permutations are omnipresent in modern combinatorics. They are omnipresent but also multifaceted, and while several excellent books explore particular aspects of the subject, no one book has covered them all. Even the classic results are scattered in various resources.Combinatorics of Permutations offers the first comprehensive, up to date treatment of both enumerative and extremal combinatorics and looks at permutation as linear orders and a
Linear models: permutation methods
Cade, B.S.
2005-01-01
Permutation tests (see Permutation Based Inference) for the linear model have applications in behavioral studies when traditional parametric assumptions about the error term in a linear model are not tenable. Improved validity of Type I error rates can be achieved with properly constructed permutation tests. Perhaps more importantly, increased statistical power, improved robustness to effects of outliers, and detection of alternative distributional differences can be achieved by coupling permutation inference with alternative linear model estimators. For example, it is well-known that estimates of the mean in linear model are extremely sensitive to even a single outlying value of the dependent variable compared to estimates of the median [7, 19]. Traditionally, linear modeling focused on estimating changes in the center of distributions (means or medians). However, quantile regression allows distributional changes to be estimated in all or any selected part of a distribution or responses, providing a more complete statistical picture that has relevance to many biological questions [6]...
Permutations of cubical arrays
International Nuclear Information System (INIS)
The structure constants of an algebra determine a cube called the cubical array associated with the algebra. The permuted indices of the cubical array associated with a finite semifield generate new division algebras. We do not not require that the algebra be finite and ask 'Is it possible to choose a basis for the algebra such any permutation of the indices of the structure constants leaves the algebra unchanged?' What are the associated algebras? Author shows that the property 'weakly quadratic' is invariant under all permutations of the indices of the corresponding cubical array and presents two algebras for which the cubical array is invariant under all permutations of the indices.
Mikel Aickin
2010-01-01
Permutation tests are often presented in a rather casual manner, in both introductory and advanced statistics textbooks. The appeal of the cleverness of the procedure seems to replace the need for a rigorous argument that it produces valid hypothesis tests. The consequence of this educational failing has been a widespread belief in a “permutation principle”, which is supposed invariably to give tests that are valid by construction, under an absolute minimum of statistical assumpti...
Aztec Diamonds and Baxter Permutations
Canary, Hal
2003-01-01
We present a proof of a conjecture about the relationship between Baxter permutations and pairs of alternating sign matrices that are produced from domino tilings of Aztec diamonds. It is shown that if and only if a tiling corresponds to a pair of ASMs that are both permutation matrices, the larger permutation matrix corresponds to a Baxter permutation. There has been a thriving literature on both pattern-avoiding permutations of various kinds and tilings of regions using dominos or rhombuses...
Energy Technology Data Exchange (ETDEWEB)
Matei, Iulia; Ionescu, Sorana [Department of Physical Chemistry, Faculty of Chemistry, University of Bucharest, Bd. Regina Elisabeta 4-12, 030018 Bucharest (Romania); Hillebrand, Mihaela, E-mail: mihh@gw-chimie.math.unibuc.ro [Department of Physical Chemistry, Faculty of Chemistry, University of Bucharest, Bd. Regina Elisabeta 4-12, 030018 Bucharest (Romania)
2011-08-15
The interaction between fisetin, an antioxidant and neuroprotective flavonoid, and human serum albumin (HSA) is investigated by means of fluorescence (steady-state, synchronous, time-resolved) and circular dichroism (CD) spectroscopy. The formation of a 1:1 complex with a constant of about 10{sup 5} M{sup -1} was evidenced. Foerster's resonance energy transfer and competitive binding with site markers warfarin and ibuprofen were considered and discussed. Changes in the CD band of HSA indicate a decrease in the {alpha}-helix content upon binding. An induced CD signal for bound fisetin was observed and rationalized in terms of density functional theory calculations. - Highlights: > Fisetin-BSA system was studied by fluorescence spectroscopy. > Binding parameters, association constant and number of sites were estimated. > Binding site of fisetin was identified by competitive experiments. > Conformational changes in HSA and fisetin were evidenced by circular dichroism. > TDDFT calculated CD spectra supported the experimental data.
Permutation statistics of products of random permutations
Hultman, Axel
2013-01-01
Given a permutation statistic $s : S_n \\to \\mathbb{R}$, define the mean statistic $\\bar{s}$ as the statistic which computes the mean of $s$ over conjugacy classes. We describe a way to calculate the expected value of $s$ on a product of $t$ independently chosen elements from the uniform distribution on a union of conjugacy classes $\\Gamma \\subseteq S_n$. In order to apply the formula, one needs to express the class function $\\bar{s}$ as a linear combination of irreducible $S_n$-characters. We...
Permutation properties of observables
International Nuclear Information System (INIS)
Relations which characterize the permutation properties of the polarization observables in nuclear reactions are derived. It is shown that the permutation symmetry of the observables in reactions with identical particles in one of the channels is independent of the reaction mechanism. The angular dependence of the vector analyzing power of the reaction d+d→p+t is studied in a model-free manner. It is proved that, contrary to conclusions reached by some authors, the angular-momentum constraints imposed by the direct mechanisms are insufficient for violating the permutation-symmetry properties. It is shown that if the reaction d+d→p+t at a few tens of MeV of energy proceeds via a pure direct mechanism (usually considered as transfer of a nucleon with l = 0) then the character of its vector analyzing power gives evidence for contributions from the l = 2 transitions
Permutation properties of observables
International Nuclear Information System (INIS)
Relations are derived which characterize the permutation properties of the polarization observables in nuclear reactions. It is shown that the permutation symmetry of the observables in reactions with identical particles in one of the channels is independent of the reaction mechanism. The angular dependence of the vector analysing power of the reaction d+d→p+t is studied in a model-free manner. It is prooved that contrary to conclusions made by some authors, the angular momentum constrains imposed by the direct mechanism are insufficient for violating the permutation properties. It is shown that if the reaction d+d→p+t at few tens MeV energy proceeds via a pure direct mechanism (usually considered as l=0 nucleon transfer), then the character of its vector analysing power gives evidence for the contribution from l=2 transitions
Permutations and quantum entanglement
International Nuclear Information System (INIS)
We construct a large class of quantum dxd states which are positive under partial transposition (so called PPT states). The construction is based on certain direct sum decomposition of the total Hilbert space which is governed by by cyclic permutation from the symmetric group Sd-i. It turns out that partial transposition maps any such decomposition into another one corresponding to 'complementary' permutation. This class contains many well known examples of PPT states from the literature and gives rise to a huge family of completely new states
Permutation Polytopes of Cyclic Groups
Baumeister, Barbara; Haase, Christian; Nill, Benjamin; Paffenholz, Andreas
2011-01-01
We investigate the combinatorics and geometry of permutation polytopes associated to cyclic permutation groups, i.e., the convex hulls of cyclic groups of permutation matrices. We give formulas for their dimension and vertex degree. In the situation that the generator of the group consists of at most two orbits, we can give a complete combinatorial description of the associated permutation polytope. In the case of three orbits the facet structure is already quite complex. For a large class of...
Permutation Tableaux and the Dashed Permutation Pattern 32-1
Chen, William Y. C.; Liu, Lewis H.
2010-01-01
We give a solution to a problem posed by Corteel and Nadeau concerning permutation tableaux of length n and the number of occurrences of the dashed pattern 32--1 in permutations on [n]. We introduce the inversion number of a permutation tableau. For a permutation tableau T and the permutation $\\pi$ obtained from T by the bijection of Corteel and Nadeau, we show that the inversion number of T equals the number of occurrences of the dashed pattern 32--1 in the reverse complement of $\\pi$. We al...
Restricted Dumont permutations
Burstein, Alexander
2004-01-01
We analyze the structure and enumerate Dumont permutations of the first and second kinds avoiding certain patterns or sets of patterns of length 3 and 4. Some cardinalities are given by Catalan numbers, powers of 2, little Schroeder numbers, and other known or related sequences.
Generalised permutation branes
International Nuclear Information System (INIS)
We propose a new class of non-factorising D-branes in the product group G x G where the fluxes and metrics on the two factors do not necessarily coincide. They generalise the maximally symmetric permutation branes which are known to exist when the fluxes agree, but break the symmetry down to the diagonal current algebra in the generic case. Evidence for the existence of these branes comes from a lagrangian description for the open string world-sheet and from effective Dirac-Born-Infeld theory. We state the geometry, gauge fields and, in the case of SU(2) x SU(2), tensions and partial results on the open string spectrum. In the latter case the generalised permutation branes provide a natural and complete explanation for the charges predicted by K-theory including their torsion
Permutationally invariant state reconstruction
Moroder, Tobias; Toth, Geza; Schwemmer, Christian; Niggebaum, Alexander; Gaile, Stefanie; Gühne, Otfried; Weinfurter, Harald
2012-01-01
Feasible tomography schemes for large particle numbers must possess, besides an appropriate data acquisition protocol, also an efficient way to reconstruct the density operator from the observed finite data set. Since state reconstruction typically requires the solution of a non-linear large-scale optimization problem, this is a major challenge in the design of scalable tomography schemes. Here we present an efficient state reconstruction scheme for permutationally invariant quantum state tomography. It works for all common state-of-the-art reconstruction principles, including, in particular, maximum likelihood and least squares methods, which are the preferred choices in today's experiments. This high efficiency is achieved by greatly reducing the dimensionality of the problem employing a particular representation of permutationally invariant states known from spin coupling combined with convex optimization, which has clear advantages regarding speed, control and accuracy in comparison to commonly employed n...
On some properties of permutation tableaux
Burstein, Alexander
2007-01-01
We consider the relation between various permutation statistics and properties of permutation tableaux. We answer some of the questions of Steingrimsson and Williams (math.CO/0507149), in particular, on the distribution of the bistatistic of numbers of rows and essential ones in permutation tableaux. We also consider and enumerate sets of permutation tableaux related to some pattern restrictions on permutations.
Partial transpose of permutation matrices
Hou, Qing-Hu; Mansour, Toufik; Severini, Simone
2007-01-01
The partial transpose of a block matrix M is the matrix obtained by transposing the blocks of M independently. We approach the notion of partial transpose from a combinatorial point of view. In this perspective, we solve some basic enumeration problems concerning the partial transpose of permutation matrices. More specifically, we count the number of permutations matrices which are equal to their partial transpose and the number of permutation matrices whose partial transpose is still a permu...
Gray Code for Cayley Permutations
Directory of Open Access Journals (Sweden)
J.-L. Baril
2003-10-01
Full Text Available A length-n Cayley permutation p of a total ordered set S is a length-n sequence of elements from S, subject to the condition that if an element x appears in p then all elements y < x also appear in p . In this paper, we give a Gray code list for the set of length-n Cayley permutations. Two successive permutations in this list differ at most in two positions.
Permutation Tests for Structural Change
Zeileis, Achim; Hothorn, Torsten
2006-01-01
The supLM test for structural change is embedded into a permutation test framework for a simple location model. The resulting conditional permutation distribution is compared to the usual (unconditional) asymptotic distribution, showing that the power of the test can be clearly improved in small samples. Furthermore, generalizations are discussed for binary and multivariate dependent variables as well as model-based permutation testing for structural change. The procedures suggested are illus...
Permutation Polytopes of Cyclic Groups
Baumeister, Barbara; Nill, Benjamin; Paffenholz, Andreas
2011-01-01
We investigate the combinatorics and geometry of permutation polytopes associated to cyclic permutation groups, i.e., the convex hulls of cyclic groups of permutation matrices. We give formulas for their dimension and vertex degree. In the situation that the generator of the group consists of at most two orbits, we can give a complete combinatorial description of the associated permutation polytope. In the case of three orbits the facet structure is already quite complex. For a large class of examples we show that there exist exponentially many facets.
Yamamoto, Yuki; Sakai, Hayato; Yuasa, Junpei; Araki, Yasuyuki; Wada, Takehiko; Sakanoue, Tomo; Takenobu, Taishi; Kawai, Tsuyoshi; Hasobe, Taku
2016-03-14
A series of fluorescent "push-pull" tetrathia[9]helicenes based on quinoxaline (acceptor) fused with tetrathia[9]helicene (donor) derivatives was synthesized for control of the excited-state dynamics and circularly polarized luminescence (CPL) properties. In this work, introduction of a quinoxaline onto the tetrathia[9]helicene skeleton induced the "push-pull" character, which was enhanced by further introduction of an electron-releasing Me2 N group or an electron-withdrawing NC group onto the quinoxaline unit (denoted as Me2 N-QTTH and NC-QTTH, respectively). These trends were successfully discussed in terms of by electrochemical measurements and density functional theory (DFT) calculations. As a consequence, significant enhancements in the fluorescence quantum yields (ΦFL ) were achieved. In particular, the maximum ΦFL of Me2 N-QTTH was 0.43 in benzene (NC-QTTH: ΦFL =0.30), which is more than 20 times larger than that of a pristine tetrathia[9]helicene (denoted as TTH; ΦFL =0.02). These enhancements were also explained by kinetic discussion of the excited-state dynamics such as fluorescence and intersystem crossing (ISC) pathways. Such significant enhancements of the ΦFL values thus enabled us to show the excellent CPL properties. The value of anisotropy factor gCPL (normalized difference in emission of right-handed and left-handed circularly polarized light) was estimated to be 3.0×10(-3) for NC-QTTH. PMID:26863928
Cyclotomy and permutation polynomials of large indices
WANG Qiang
2012-01-01
We use cyclotomy to design new classes of permutation polynomials over finite fields. This allows us to generate many classes of permutation polynomials in an algorithmic way. Many of them are permutation polynomials of large indices.
Permutationally invariant state reconstruction
DEFF Research Database (Denmark)
Moroder, Tobias; Hyllus, Philipp; Tóth, Géza;
2012-01-01
Feasible tomography schemes for large particle numbers must possess, besides an appropriate data acquisition protocol, an efficient way to reconstruct the density operator from the observed finite data set. Since state reconstruction typically requires the solution of a nonlinear large-scale opti......Feasible tomography schemes for large particle numbers must possess, besides an appropriate data acquisition protocol, an efficient way to reconstruct the density operator from the observed finite data set. Since state reconstruction typically requires the solution of a nonlinear large......-scale optimization problem, this is a major challenge in the design of scalable tomography schemes. Here we present an efficient state reconstruction scheme for permutationally invariant quantum state tomography. It works for all common state-of-the-art reconstruction principles, including, in particular, maximum...... likelihood and least squares methods, which are the preferred choices in today's experiments. This high efficiency is achieved by greatly reducing the dimensionality of the problem employing a particular representation of permutationally invariant states known from spin coupling combined with convex...
Generalised N=2 permutation branes
International Nuclear Information System (INIS)
Generalised permutation branes in products of N = 2 minimal models play an important role in accounting for all RR charges of Gepner models. In this paper an explicit conformal field theory construction of these generalised permutation branes for one simple class of examples is given. We also comment on how this may be generalised to the other cases
Tetrachoric Correlation: A Permutation Alternative
Long, Michael A.; Berry, Kenneth J.; Mielke, Paul W., Jr.
2009-01-01
An exact permutation test is provided for the tetrachoric correlation coefficient. Comparisons with the conventional test employing Student's t distribution demonstrate the necessity of using the permutation approach for small sample sizes and/or disproportionate marginal frequency totals. (Contains 4 tables.)
Lee, Geon Joon; Sim, Geon Bo; Choi, Eun Ha; Kwon, Young-Wan; Kim, Jun Young; Jang, Siun; Kim, Seong Hwan
2015-01-01
To understand the killing mechanism of fungal spores by plasma treatment, the optical, structural, and biological properties of the insect pathogenic fungus Cordyceps bassiana spores were studied. A nonthermal atmospheric-pressure plasma jet (APPJ) was used to treat the spores in aqueous solution. Optical emission spectra of the APPJ acquired in air indicated emission peaks corresponding to hydroxyl radicals and atomic oxygen. When the APPJ entered the aqueous solution, additional reactive species were derived from the interaction of plasma radicals with the aqueous solution. Fluorescence and absorption spectroscopy confirmed the generation of hydroxyl radicals and hydrogen peroxide in the plasma-activated water (PAW). Spore counting showed that plasma treatment significantly reduced spore viability. Absorption spectroscopy, circular dichroism (CD) spectroscopy, and agarose gel electrophoresis of the DNA extracted from plasma-treated spores showed a reduction in spore DNA content. The magnitude of the dip in the CD spectrum was lower in the plasma-treated spores than in the control, indicating that plasma treatment causes structural modifications and/or damage to cellular components. Tryptophan fluorescence intensity was lower in the plasma-treated spores than in the control, suggesting that plasma treatment modified cell wall proteins. Changes in spore viability and DNA content were attributed to structural modification of the cell wall by reactive species coming from the APPJ and the PAW. Our results provided evidence that the plasma radicals and the derived reactive species play critical roles in fungal spore inactivation.
Energy Technology Data Exchange (ETDEWEB)
Lee, Geon Joon, E-mail: gjlee@kw.ac.kr; Sim, Geon Bo; Choi, Eun Ha [Plasma Bioscience Research Center/Department of Electrical and Biological Physics, Kwangwoon University, Seoul 139-701 (Korea, Republic of); Kwon, Young-Wan [KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 136-701 (Korea, Republic of); Kim, Jun Young; Jang, Siun; Kim, Seong Hwan, E-mail: piceae@naver.com [Department of Microbiology and Institute of Basic Sciences, Dankook University, Cheonan 330-714 (Korea, Republic of)
2015-01-14
To understand the killing mechanism of fungal spores by plasma treatment, the optical, structural, and biological properties of the insect pathogenic fungus Cordyceps bassiana spores were studied. A nonthermal atmospheric-pressure plasma jet (APPJ) was used to treat the spores in aqueous solution. Optical emission spectra of the APPJ acquired in air indicated emission peaks corresponding to hydroxyl radicals and atomic oxygen. When the APPJ entered the aqueous solution, additional reactive species were derived from the interaction of plasma radicals with the aqueous solution. Fluorescence and absorption spectroscopy confirmed the generation of hydroxyl radicals and hydrogen peroxide in the plasma-activated water (PAW). Spore counting showed that plasma treatment significantly reduced spore viability. Absorption spectroscopy, circular dichroism (CD) spectroscopy, and agarose gel electrophoresis of the DNA extracted from plasma-treated spores showed a reduction in spore DNA content. The magnitude of the dip in the CD spectrum was lower in the plasma-treated spores than in the control, indicating that plasma treatment causes structural modifications and/or damage to cellular components. Tryptophan fluorescence intensity was lower in the plasma-treated spores than in the control, suggesting that plasma treatment modified cell wall proteins. Changes in spore viability and DNA content were attributed to structural modification of the cell wall by reactive species coming from the APPJ and the PAW. Our results provided evidence that the plasma radicals and the derived reactive species play critical roles in fungal spore inactivation.
Permutability degrees of finite groups
Otera, Daniele Ettore; Russo, Francesco G.
2015-01-01
Given a finite group $G$, we introduce the \\textit{permutability degree} of $G$, as $$pd(G)=\\frac{1}{|G| \\ |\\mathcal{L}(G)|} {\\underset{X \\in \\mathcal{L}(G)}\\sum}|P_G(X)|,$$ where $\\mathcal{L}(G)$ is the subgroup lattice of $G$ and $P_G(X)$ the permutizer of the subgroup $X$ in $G$, that is, the subgroup generated by all cyclic subgroups of $G$ that permute with $X\\in \\mathcal{L}(G)$. The number $pd(G)$ allows us to find some structural restrictions on $G$. Successively, we investigate the re...
Hopf algebra of permutation pattern functions
Vargas, Yannic
2014-01-01
We study permutation patterns from an algebraic combinatorics point of view. Using analogues of the classical shuffle and infiltration products for word, we define two new Hopf algebras of permutations related to the notion of permutation pattern. We show several remarkable properties of permutation patterns functions, as well their occurrence in other domains.
Permutation orientifolds of Gepner models
International Nuclear Information System (INIS)
In tensor products of a left-right symmetric CFT, one can define permutation orientifolds by combining orientation reversal with involutive permutation symmetries. We construct the corresponding crosscap states in general rational CFTs and their orbifolds, and study in detail those in products of affine U(1)2 models or N = 2 minimal models. The results are used to construct permutation orientifolds of Gepner models. We list the permutation orientifolds in a few simple Gepner models, and study some of their physical properties - supersymmetry, tension and RR charges. We also study the action of corresponding parity on D-branes, and determine the gauge group on a stack of parity-invariant D-branes. Tadpole cancellation condition and some of its solutions are also presented
Multivariate permutation tests in genetics.
Rosa Arboretti Giancristofaro
2003-01-01
In this paper we provide some new statistical results for hypotheses testing in genetics particularly referred to multivariate allelic association studies. An extensive power simulation study is also provided on permutation solutions.
Permutation symmetry of polyatomic systems
International Nuclear Information System (INIS)
A new method of arranging irreducible representations -symmetrized groups of multiatom system function permutation is proposed. The method was rtested using a simple model - linear chain of hydrogen atoms
Multi-level block permutation.
Winkler, Anderson M; Webster, Matthew A; Vidaurre, Diego; Nichols, Thomas E; Smith, Stephen M
2015-12-01
Under weak and reasonable assumptions, mainly that data are exchangeable under the null hypothesis, permutation tests can provide exact control of false positives and allow the use of various non-standard statistics. There are, however, various common examples in which global exchangeability can be violated, including paired tests, tests that involve repeated measurements, tests in which subjects are relatives (members of pedigrees) - any dataset with known dependence among observations. In these cases, some permutations, if performed, would create data that would not possess the original dependence structure, and thus, should not be used to construct the reference (null) distribution. To allow permutation inference in such cases, we test the null hypothesis using only a subset of all otherwise possible permutations, i.e., using only the rearrangements of the data that respect exchangeability, thus retaining the original joint distribution unaltered. In a previous study, we defined exchangeability for blocks of data, as opposed to each datum individually, then allowing permutations to happen within block, or the blocks as a whole to be permuted. Here we extend that notion to allow blocks to be nested, in a hierarchical, multi-level definition. We do not explicitly model the degree of dependence between observations, only the lack of independence; the dependence is implicitly accounted for by the hierarchy and by the permutation scheme. The strategy is compatible with heteroscedasticity and variance groups, and can be used with permutations, sign flippings, or both combined. We evaluate the method for various dependence structures, apply it to real data from the Human Connectome Project (HCP) as an example application, show that false positives can be avoided in such cases, and provide a software implementation of the proposed approach. PMID:26074200
Maps, immersions and permutations
Coquereaux, Robert
2015-01-01
We consider the problem of counting and of listing topologically inequivalent "planar" {4-valent} maps with a single component and a given number n of vertices. This enables us to count and to tabulate immersions of a circle in a sphere (spherical curves), extending results by Arnold and followers. Different options where the circle and/or the sphere are/is oriented are considered in turn, following Arnold's classification of the different types of symmetries. We also consider the case of bicolourable and bicoloured maps or immersions, where faces are bicoloured. Our method extends to immersions of a circle in a higher genus Riemann surface. There the bicolourability is no longer automatic and has to be assumed. We thus have two separate countings in non zero genus, that of bicolourable maps and that of general maps. We use a classical method of encoding maps in terms of permutations, on which the constraints of "one-componentness" and of a given genus may be applied. Depending on the orientation issue and on...
Permutation Complexity in Dynamical Systems
Amigo, Jose
2010-01-01
The study of permutation complexity can be envisioned as a new kind of symbolic dynamics whose basic blocks are ordinal patterns, that is, permutations defined by the order relations among points in the orbits of dynamical systems. Since its inception in 2002 the concept of permutation entropy has sparked a new branch of research in particular regarding the time series analysis of dynamical systems that capitalizes on the order structure of the state space. Indeed, on one hand ordinal patterns and periodic points are closely related, yet ordinal patterns are amenable to numerical methods, while periodicity is not. Another interesting feature is that since it can be shown that random (unconstrained) dynamics has no forbidden patterns with probability one, their existence can be used as a fingerprint to identify any deterministic origin of orbit generation. This book is primarily addressed to researchers working in the field of nonlinear dynamics and complex systems, yet will also be suitable for graduate stude...
Simsun permutations, simsun successions and simsun patterns
Ma, Shi-Mei; Yeh, Yeong-Nan
2016-01-01
In this paper, we introduce the definitions of simsun succession, simsun cycle succession and simsun pattern. In particular, the ordinary simsun permutations are permutations avoiding simsun pattern 321. We study the descent and peak statistics on permutations avoiding simsun successions. We give a combinatorial interpretation of the q-Eulerian polynomials introduced by Brenti (J. Combin. Theory Ser. A 91 (2000), 137-170). We also present a bijection between permutations avoiding simsun patte...
A Class of Binomial Permutation Polynomials
Tu, Ziran; Zeng, Xiangyong; Hu, Lei; Li, Chunlei
2013-01-01
In this note, a criterion for a class of binomials to be permutation polynomials is proposed. As a consequence, many classes of binomial permutation polynomials and monomial complete permutation polynomials are obtained. The exponents in these monomials are of Niho type.
Permutation presentations of modules over finite groups
Katsura, Takeshi
2006-01-01
We introduce a notion of permutation presentations of modules over finite groups, and completely determine finite groups over which every module has a permutation presentation. To get this result, we prove that every coflasque module over a cyclic p-group is permutation projective.
Face-subgroups of permutation polytopes
Haase, Christian
2015-01-01
In [Baumeister, H., Nill, Paffenholz, On permutation polytopes, Adv. Math. 222 (2009), 431-452 / arXiv:0709.1615] we conjectured a characterization of subgroups H of a permutation group G so that, on the level of permutation polytopes, P(H) is a face of P(G). Here we present the embarrassingly simple proof of this conjecture.
Cell flipping in permutation diagrams
Golumbic, Martin Charles; Kaplang, Haim
Permutation diagrams have been used in circuit design to model a set of single point nets crossing a channel, where the minimum number of layers needed to realize the diagram equals the clique number ω(G) of its permutation graph, the value of which can be calculated in O(n log n) time. We consider a generalization of this model motivated by "standard cell" technology in which the numbers on each side of the channel are partitioned into consecutive subsequences, or cells, each of which can be left unchanged or flipped (i.e., reversed). We ask, for what choice of fiippings will the resulting clique number be minimum or maximum. We show that when one side of the channel is fixed (no flipping), an optimal flipping for the other side can be found in O(n log n) time for the maximum clique number. We prove that the general problem is NP-complete for the minimum clique number and O(n 2) for the maximum clique number. Moreover, since the complement of a permutation graph is also a permutation graph, the same complexity results hold for the independence number.
Explorations in Statistics: Permutation Methods
Curran-Everett, Douglas
2012-01-01
Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This eighth installment of "Explorations in Statistics" explores permutation methods, empiric procedures we can use to assess an experimental result--to test a null hypothesis--when we are reluctant to trust statistical…
Permutation orbifolds and their applications
Bántay, P
2001-01-01
The theory of permutation orbifolds is reviewed and applied to the study of symmetric product orbifolds and the congruence subgroup problem. The issue of discrete torsion, the combinatorics of symmetric products, the Galois action and questions related to the classification of RCFTs are also discussed.
Improved Bounds for Geometric Permutations
Rubin, Natan; Sharir, Micha
2010-01-01
We show that the number of geometric permutations of an arbitrary collection of $n$ pairwise disjoint convex sets in $\\mathbb{R}^d$, for $d\\geq 3$, is $O(n^{2d-3}\\log n)$, improving Wenger's 20 years old bound of $O(n^{2d-2})$.
Decryption of pure-position permutation algorithms
Institute of Scientific and Technical Information of China (English)
赵晓宇; 陈刚; 张亶; 王肖虹; 董光昌
2004-01-01
Pure position permutation image encryption algorithms, commonly used as image encryption investigated in this work are unfortunately frail under known-text attack. In view of the weakness of pure position permutation algorithm,we put forward an effective decryption algorithm for all pure-position permutation algorithms. First, a summary of the pure position permutation image encryption algorithms is given by introducing the concept of ergodic matrices. Then, by using probability theory and algebraic principles, the decryption probability of pure-position permutation algorithms is verified theoretically; and then, by defining the operation system of fuzzy ergodic matrices, we improve a specific decryption al-gorithm. Finally, some simulation results are shown.
Matrix factorisations and permutation branes
International Nuclear Information System (INIS)
The description of B-type D-branes on a tensor product of two N = 2 minimal models in terms of matrix factorisations is related to the boundary state description in conformal field theory. As an application we show that the D0- and D2-brane for a number of Gepner models are described by permutation boundary states. In some cases (including the quintic) the images of the D2-brane under the Gepner monodromy generate the full charge lattice
Witt Rings and Permutation Polynomials
Institute of Scientific and Technical Information of China (English)
Qifan Zhang
2005-01-01
Let p be a prime number. In this paper, the author sets up a canonical correspondence between polynomial functions over Z/p2Z and 3-tuples of polynomial functions over Z/pZ. Based on this correspondence, he proves and reproves some fundamental results on permutation polynomials mod pl. The main new result is the characterization of strong orthogonal systems over Z/p1Z.
Permutation interpretation of quantum mechanics
International Nuclear Information System (INIS)
We analyse quantum concepts in a constructive finite background. Introduction of continuum or other actual infinities into physics leads to non-constructivity without any need for them in description of empirical observations. We argue that quantum behavior is a natural consequence of symmetries of dynamical systems. It is a result of fundamental impossibility to trace identity of indistinguishable objects in their evolution — only information about invariant combinations of such objects is available. General mathematical arguments imply that any quantum dynamics can be reduced to a sequence of permutations. Quantum phenomena, such as interferences, arise in invariant subspaces of permutation representations of the symmetry group of a system. Observable quantities can be expressed in terms of the permutation invariants. We demonstrate that for description of quantum phenomena there is no need to use such non-constructive number system as complex numbers. It is sufficient to employ the cyclotomic numbers — a minimal extension of the natural numbers which is suitable for quantum mechanics.
The permutation testing approach: a review
Fortunato Pesarin; Luigi Salmaso
2013-01-01
In recent years permutation testing methods have increased both in number of applications and in solving complex multivariate problems. A large number of testing problems may also be usefully and effectively solved by traditional parametric or rank-based nonparametric methods, although in relatively mild conditions their permutation counterparts are generally asymptotically as good as the best ones. Permutation tests are essentially of an exact nonparametric nature in a conditional context, w...
Tensor Permutation Matrices in Finite Dimensions
Christian, Rakotonirina
2005-01-01
We have generalised the properties with the tensor product, of one 4x4 matrix which is a permutation matrix, and we call a tensor commutation matrix. Tensor commutation matrices can be constructed with or without calculus. A formula allows us to construct a tensor permutation matrix, which is a generalisation of tensor commutation matrix, has been established. The expression of an element of a tensor commutation matrix has been generalised in the case of any element of a tensor permutation ma...
New Classes of Permutation Binomials and Permutation Trinomials over Finite Fields
Li, Kangquan; Qu, Longjiang; Chen, Xi
2015-01-01
Permutation polynomials over finite fields play important roles in finite fields theory. They also have wide applications in many areas of science and engineering such as coding theory, cryptography, combinatorial design, communication theory and so on. Permutation binomials and trinomials attract people's interest due to their simple algebraic form and additional extraordinary properties. In this paper, several new classes of permutation binomials and permutation trinomials are constructed. ...
Urfer, Jean-Marie
2006-01-01
This dissertation is concerned with the study of a new family of representations of finite groups, the endo-p-permutation modules. Given a prime number p, a finite group G of order divisible by p and an algebraically closed field k of characteristic p, we say that a kG-module M is an endo-p-permutation module if its endomorphism algebra Endk(M) is a p-permutation kG-module, that is a direct summand of a permutation kG-module. This generalizes the notion, first introduced by E. Dade in 1978, o...
Urfer, Jean-Marie; Thévenaz, Jacques
2007-01-01
This dissertation is concerned with the study of a new family of representations of finite groups, the endo-p-permutation modules. Given a prime number p, a finite group G of order divisible by p and an algebraically closed field k of characteristic p, we say that a kG-module M is an endo-p-permutation module if its endomorphism algebra Endk(M) is a p-permutation kG-module, that is a direct summand of a permutation kG-module. This generalizes the notion, first introduced by E. Dade in 1978, o...
Congruence Permutable Symmetric Extended de Morgan Algebras
Institute of Scientific and Technical Information of China (English)
Jie FANG
2006-01-01
An algebra A is said to be congruence permutable if any two congruences on it are per-mutable. This property has been investigated in several varieties of algebras, for example, de Morgan algebras, p-algebras, Kn,o-algebras. In this paper, we study the class of symmetric extended de Morgan algebras that are congruence permutable. In particular we consider the case where A is finite, and show that A is congruence permutable if and only if it is isomorphic to a direct product of finitely many simple algebras.
Permutation group in light nuclei
International Nuclear Information System (INIS)
From general features of the multiplet scheme, a framework is provided for the application of permutation groups to the structure of light nuclei. It is shown that the description of nuclear states in terms of cluster configurations offers possibilities of finding the best orbital states for a given partition f. The significance of the orbital partition for orbital states is explained in terms of selection rules. Specific methods and results obtained in shell configurations, cluster configurations, and nuclear reactions are discussed. (2 figures, 4 tables, 42 references) (U.S.)
Czech Academy of Sciences Publication Activity Database
Humpolíčková, Jana; Štěpánek, M.; Kral, Teresa; Benda, Aleš; Procházka, K.; Hof, Martin
2008-01-01
Roč. 18, 3-4 (2008), s. 679-684. ISSN 1053-0509 R&D Projects: GA AV ČR IAA400400621; GA MŠk(CZ) LC06063 Institutional research plan: CEZ:AV0Z40400503 Keywords : DNA compaction * fluorescence correlation spectroscopy * fluorescence lifetime correlation spectroscopy * dynamic light scattering Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.880, year: 2008
2001-01-01
In der Komposition von Fugen bezeichnet der Begriff den mehrmaligen Stimmtausch zwischen einem Soggetto und seinen jeweils unverändert auftretenden Kontrasubjekten, wobei sämtliche durch die Stimmenzahl festgelegten Kombinationsmöglichkeiten durchgespielt werden.
International Nuclear Information System (INIS)
The influence that urea has on the conformation of water-soluble globular protein, bovine serum albumin (BSA), exposed directly to the aqueous solution as compared to the condition where the macromolecule is confined in the Aerosol-OT (AOT - sodium bis-2-ethylhexyl sulfosuccinate)/n-hexane/water reverse micelle (RM) is addressed. Small angle X-ray scattering (SAXS), tryptophan (Trp) fluorescence emission and circular dichroism (CD) spectra of aqueous BSA solution in the absence and in the presence of urea (3M and 5M) confirm the known denaturing effect of urea in proteins. The loss of the globular native structure is observed by the increase in the protein maximum dimension and gyration radius, through the Trp emission increase and maximum red-shift as well as the decrease in helix content. In RMs, the Trp fluorescence and CD spectra show that BSA is mainly located in its interfacial region independently of the micellar size. Addition of urea in this BSA/RM system also causes changes in the Trp fluorescence (emission decrease and maximum red-shift) and in the BSA CD spectra (decrease in helix content), which are compatible with the denaturation of the protein and Trp exposition to a more apolar environment in the RM. The fact that urea causes changes in the protein structure when it is located in the interfacial region (evidenced by CD) is interpreted as an indication that the direct interaction of urea with the protein is the major factor to explain its denaturing effect. (author)
Permutation codes for the Laplacian source
Townes, S. A.; Oneal, J. B., Jr.
1984-01-01
Permutation codes for the Laplacian source are developed. The performance of these codes is evaluated and compared with other quantizers and the rate-distortion function. It is shown that there is a bit-rate region in which the permutation codes outperform certain single-sample quantizers.
Permutation branes and linear matrix factorisations
International Nuclear Information System (INIS)
All the known rational boundary states for Gepner models can be regarded as permutation branes. On general grounds, one expects that topological branes in Gepner models can be encoded as matrix factorisations of the corresponding Landau-Ginzburg potentials. In this paper we identify the matrix factorisations associated to arbitrary B-type permutation branes
Symmetric products, permutation orbifolds and discrete torsion
Bántay, P
2000-01-01
Symmetric product orbifolds, i.e. permutation orbifolds of the full symmetric group S_{n} are considered by applying the general techniques of permutation orbifolds. Generating functions for various quantities, e.g. the torus partition functions and the Klein-bottle amplitudes are presented, as well as a simple expression for the discrete torsion coefficients.
Decryption of pure-position permutation algorithms
Institute of Scientific and Technical Information of China (English)
赵晓宇; 陈刚; 张亶; 王肖虹; 董光昌
2004-01-01
Pure position permutation image encryption algorithms,commonly used as image encryption investigated in this work are unfortunately frail under known-text attack.In view of the weakness of pure position permutation algorithm,we put forward an effective decryption algorithm for all pure-position permutation algorithms.First,a summary of the pure position permutation image encryption algorithms is given by introducing the concept of ergodic matrices.Then,by using probability theory and algebraic principles,the decryption probability of pure-position permutation algorithms is verified theoretically; and then,by defining the operation system of fuzzy ergodic matrices,we improve a specific decryption algorithm.Finally,some simulation results are shown.
Engineering and Characterization of a Superfolder Green Fluorescent Protein
International Nuclear Information System (INIS)
Existing variants of green fluorescent protein (GFP) often misfold when expressed as fusions with other proteins. We have generated a robustly folded version of GFP, called 'superfolder' GFP, that folds well even when fused to poorly folded polypeptides. Compared to 'folding reporter' GFP, a folding-enhanced GFP containing the 'cycle-3' mutations and the 'enhanced GFP' mutations F64L and S65T, superfolder GFP shows improved tolerance of circular permutation, greater resistance to chemical denaturants and improved folding kinetics. The fluorescence of Escherichia coli cells expressing each of eighteen proteins from Pyrobaculum aerophilum as fusions with superfolder GFP was proportional to total protein expression. In contrast, fluorescence of folding reporter GFP fusion proteins was strongly correlated with the productive folding yield of the passenger protein. X-ray crystallographic structural analyses helped explain the enhanced folding of superfolder GFP relative to folding reporter GFP
Permutation symmetry of polyatomic systems
International Nuclear Information System (INIS)
The Pauli principle can be taken into account if a many-electron wavefunction is written in determinantal form. A new method is suggested of constructing wavefunctions for a polyatomic system that are symmetrized with respect to the irreducible representations of the permutation groups. The method is tested on a simple model of a linear chain of hydrogen atoms. The strategy of this study is to construct symmetrized basis functions for the irreducible representations of the πN(N=26) group using the Young-operator method, to find the essential properties of these functions, then to specify a procedure for constructing the basis functions for arbitrary N, and finally to test it on a linear HN molecule. 12 refs., 3 figs
Lower bounding edit distances between permutations
Labarre, Anthony
2012-01-01
A number of fields, including the study of genome rearrangements and the design of interconnection networks, deal with the connected problems of sorting permutations in "as few moves as possible", using a given set of allowed operations, or computing the number of moves the sorting process requires, often referred to as the \\emph{distance} of the permutation. These operations often act on just one or two segments of the permutation, e.g. by reversing one segment or exchanging two segments. The \\emph{cycle graph} of the permutation to sort is a fundamental tool in the theory of genome rearrangements, and has proved useful in settling the complexity of many variants of the above problems. In this paper, we present an algebraic reinterpretation of the cycle graph of a permutation $\\pi$ as an even permutation $\\bar{\\pi}$, and show how to reformulate our sorting problems in terms of particular factorisations of the latter permutation. Using our framework, we recover known results in a simple and unified way, and o...
Département des Ressources humaines
2004-01-01
Administrative Circular N° 2 (Rev. 2) - May 2004 Guidelines and procedures concerning recruitment and probation period of staff members This circular has been revised. It cancels and replaces Administrative Circular N° 2 (Rev. 1) - March 2000. Administrative Circular N° 9 (Rev. 3) - May 2004 Staff members contracts This circular has been revised. It cancels and replaces Administrative Circular N° 9 (Rev. 2) - March 2000. Administrative Circular N° 26 (Rev. 4) - May 2004 Procedure governing the career evolution of staff members This circular has also been revised. It Administrative Circulars Administrative Circular N° 26 (Rev. 3) - December 2001 and brings up to date the French version (Rev. 4) published on the HR Department Web site in January 2004. Operational Circular N° 7 - May 2004 Work from home This circular has been drawn up. Operational Circular N° 8 - May 2004 Dealing with alcohol-related problems...
Counting Fixed-Length Permutation Patterns
Cheyne Homberger
2012-01-01
We consider the problem of packing fixed-length patterns into a permutation, and develop a connection between the number of large patterns and the number of bonds in a permutation. Improving upon a result of Kaplansky and Wolfowitz, we obtain exact values for the expectation and variance for the number of large patterns in a random permutation. Finally, we are able to generalize the idea of bonds to obtain results on fixed-length patterns of any size, and present a construction that maximizes...
On permutation polynomials over finite fields
C. Small; R. A. Mollin
1987-01-01
A polynomial f over a finite field F is called a permutation polynomial if the mapping FÃ¢Â†Â’F defined by f is one-to-one. In this paper we consider the problem of characterizing permutation polynomials; that is, we seek conditions on the coefficients of a polynomial which are necessary and sufficient for it to represent a permutation. We also give some results bearing on a conjecture of Carlitz which says essentially that for any even integer m, the cardinality of finite fields admitting pe...
Permutation parity machines for neural synchronization
International Nuclear Information System (INIS)
Synchronization of neural networks has been studied in recent years as an alternative to cryptographic applications such as the realization of symmetric key exchange protocols. This paper presents a first view of the so-called permutation parity machine, an artificial neural network proposed as a binary variant of the tree parity machine. The dynamics of the synchronization process by mutual learning between permutation parity machines is analytically studied and the results are compared with those of tree parity machines. It will turn out that for neural synchronization, permutation parity machines form a viable alternative to tree parity machines
Extending The Range of Application of Permutation Tests: the Expected Permutation p-value Approach
Commenges, Daniel
2010-01-01
The limitation of permutation tests is that they assume exchangeability. It is shown that in generalized linear models one can construct permutation tests from score statistics in particular cases. When under the null hypothesis the observations are not exchangeable, a representation in terms of Cox-Snell residuals allows to develop an approach based on an expected permutation p-value (Eppv); this is applied to the logistic regression model. A small simulation study and an illustration with r...
EPC: A Provably Secure Permutation Based Compression Function
DEFF Research Database (Denmark)
Bagheri, Nasour; Gauravaram, Praveen; Naderi, Majid; Sadeghiyan, Babak
The security of permutation-based hash functions in the ideal permutation model has been studied when the input-length of compression function is larger than the input-length of the permutation function. In this paper, we consider permutation based compression functions that have input lengths...... shorter than that of the permutation. Under this assumption, we propose a permutation based compression function and prove its security with respect to collision and (second) preimage attacks in the ideal permutation model. The proposed compression function can be seen as a generalization of the...
Permutation Orbifolds in the large N Limit
Belin, Alexandre; Maloney, Alexander
2015-01-01
The space of permutation orbifolds is a simple landscape of two dimensional CFTs, generalizing the well-known symmetric orbifolds. We consider constraints which a permutation orbifold with large central charge must obey in order to be holographically dual to a weakly coupled (but possibly stringy) theory of gravity in AdS. We then construct explicit examples of permutation orbifolds which obey these constraints. In our constructions the spectrum remains finite at large N, but differs qualitatively from that of symmetric orbifolds. We also discuss under what conditions the correlation functions factorize at large N and thus reduce to those of a generalized free field in AdS. We show that this happens not just for symmetric orbifolds, but also for permutation groups which act "democratically" in a sense which we define.
On solvable minimally transitive permutation groups
Dalla Volta, Francesca; Siemons, Johannes
2007-01-01
We investigate properties of finite transitive permutation groups $(G, \\Omega)$ in which all proper subgroups of $G$ act intransitively on $\\Omega.$ In particular, we are interested in reduction theorems for minimally transitive representations of solvable groups.
An interesting new Mahonian permutation statistic
Wilson, Mark C.
2010-01-01
The standard algorithm for generating a random permutation gives rise to an obvious permutation statistic $\\stat$ that is readily seen to be Mahonian. We give evidence showing that it is not equal to any previously published statistic. Nor does its joint distribution with the standard Eulerian statistics $\\des$ and $\\exc$ appear to coincide with any known Euler-Mahonian pair. A general construction of Skandera yields an Eulerian partner $\\ska$ such that $(\\ska, \\stat)$ is equidistributed with...
Permutation parity machines for neural cryptography
International Nuclear Information System (INIS)
Recently, synchronization was proved for permutation parity machines, multilayer feed-forward neural networks proposed as a binary variant of the tree parity machines. This ability was already used in the case of tree parity machines to introduce a key-exchange protocol. In this paper, a protocol based on permutation parity machines is proposed and its performance against common attacks (simple, geometric, majority and genetic) is studied.
On the Sign-imbalance of Permutation Tableaux
Chen, Joanna N.; Zhou, Robin D. P.
2016-01-01
Permutation tableaux were introduced by Steingr\\'{\\i}msson and Williams. Corteel and Kim defined the sign of a permutation tableau in terms of the number of unrestricted columns. The sign-imbalance of permutation tableaux of length $n$ is the sum of signs over permutation tableaux of length $n$. They have btained a formula for the sign-imbalance of permutation tableaux of length $n$ by using generating functions and asked for a combinatorial proof. Moreover, they raised the question of findin...
The permutation testing approach: a review
Directory of Open Access Journals (Sweden)
Fortunato Pesarin
2013-05-01
Full Text Available In recent years permutation testing methods have increased both in number of applications and in solving complex multivariate problems. A large number of testing problems may also be usefully and effectively solved by traditional parametric or rank-based nonparametric methods, although in relatively mild conditions their permutation counterparts are generally asymptotically as good as the best ones. Permutation tests are essentially of an exact nonparametric nature in a conditional context, where conditioning is on the pooled observed data as a set of sufficient statistics in the null hypothesis. Instead, the reference null distribution of most parametric tests is only known asymptotically. Thus, for most sample sizes of practical interest, the possible lack of efficiency of permutation solutions may be compensated by the lack of approximation of parametric counterparts. There are many complex multivariate problems (quite common in biostatistics, clinical trials, engineering, the environment, epidemiology, experimental data, industrial statistics, pharmacology, psychology, social sciences, etc. which are difficult to solve outside the conditional framework and outside the nonparametric combination (NPC method for dependent permutation tests. In this paper we review this method along with a number of applications in different experimental and observational situations (e.g. multi-sided alternatives, zero-inflated data and testing for a stochastic ordering and we present properties specific to this methodology, such as: for a given number of subjects, when the number of variables diverges and the noncentrality of the combined test diverges accordingly, then the power of combination-based permutation tests converges to one.
Interfaces in sequence permutated multilayers
Energy Technology Data Exchange (ETDEWEB)
Balogh, J; Bujdoso, L; Kaptas, D; Kiss, L F; Kemeny, T; Vincze, I, E-mail: baloghj@szfki.h [Research Institute for Solid State Physics and Optics, 1525 Budapest PO Box 49 (Hungary)
2010-03-01
Sequence permutation of three building block multilayers was recently suggested as a new approach in studying bottom and top interfaces formed of a given layer with either of the other two elements. It was applied to Fe-B-Ag multilayers with 5 nm Ag layers separating the Fe and the B layers. Now we examine the dependence of the chemical mixing and the consequent amorphous phase formation on the nominal thickness of the Ag layers in [2 nm B / 2nm Fe / x nm Ag]{sub 4}, 0.2{<=}x{<=}10, multilayers. The ratio of the non-alloyed Fe layer and the amorphous Fe-B interface compound changes only below x=5 nm. It is attributed to discontinuities of the Ag layer due to its three dimensional island growth over the bcc-Fe layer. The results obtained on the variation of the hyperfine field distribution of the amorhous Fe-B layers also confirm that the top interfaces of Fe with B are more B-rich than the bottom ones.
Duman, Osman; Tunç, Sibel; Kancı Bozoğlan, Bahar
2013-07-01
The interactions of metoprolol tartrate (MPT) and guaifenesin (GF) drugs with human serum albumin (HSA) and human hemoglobin (HMG) proteins at pH 7.4 were studied by fluorescence and circular dichroism (CD) spectroscopy. Drugs quenched the fluorescence spectra of HSA and HMG proteins through a static quenching mechanism. For each protein-drug system, the values of Stern-Volmer quenching constant, bimolecular quenching constant, binding constant and number of binding site on the protein molecules were determined at 288.15, 298.15, 310.15 and 318.15 K. It was found that the binding constants of HSA-MPT and HSA-GF systems were smaller than those of HMG-MPT and HMG-GF systems. For both drugs, the affinity of HMG was much higher than that of HSA. An increase in temperature caused a negative effect on the binding reactions. The number of binding site on blood proteins for MPT and GF drugs was approximately one. Thermodynamic parameters showed that MPT interacted with HSA through electrostatic attraction forces. However, hydrogen bonds and van der Waals forces were the main interaction forces in the formation of HSA-GF, HMG-MPT and HMG-GF complexes. The binding processes between protein and drug molecules were exothermic and spontaneous owing to negative ∆H and ∆G values, respectively. The values of binding distance between protein and drug molecules were calculated from Förster resonance energy transfer theory. It was found from CD analysis that the bindings of MPT and GF drugs to HSA and HMG proteins altered the secondary structure of HSA and HMG proteins. PMID:23471625
Permutation statistical methods an integrated approach
Berry, Kenneth J; Johnston, Janis E
2016-01-01
This research monograph provides a synthesis of a number of statistical tests and measures, which, at first consideration, appear disjoint and unrelated. Numerous comparisons of permutation and classical statistical methods are presented, and the two methods are compared via probability values and, where appropriate, measures of effect size. Permutation statistical methods, compared to classical statistical methods, do not rely on theoretical distributions, avoid the usual assumptions of normality and homogeneity of variance, and depend only on the data at hand. This text takes a unique approach to explaining statistics by integrating a large variety of statistical methods, and establishing the rigor of a topic that to many may seem to be a nascent field in statistics. This topic is new in that it took modern computing power to make permutation methods available to people working in the mainstream of research. This research monograph addresses a statistically-informed audience, and can also easily serve as a ...
Toric CFTs, Permutation Triples and Belyi Pairs
Jejjala, Vishnu; Rodriguez-Gomez, Diego
2010-01-01
Four-dimensional CFTs dual to branes transverse to toric Calabi--Yau threefolds have been described by bipartite graphs on a torus (dimer models). We use the theory of dessins d'enfants to describe these in terms of triples of permutations which multiply to one. These permutations yield an elegant description of zig-zag paths, which have appeared in characterizing the toroidal dimers that lead to consistent SCFTs. The dessins are also related to Belyi pairs, consisting of a curve equipped with a map to P^1, branched over three points on the P^1. We construct explicit examples of Belyi pairs associated to some CFTs, including C^3 and the conifold. Permutation symmetries of the superpotential are related to the geometry of the Belyi pair. The Artin braid group action and a variation thereof play an interesting role. We make a conjecture relating the complex structure of the Belyi curve to R-charges in the conformal field theory.
Isometries and Construction of Permutation Arrays
Bogaerts, Mathieu
2009-01-01
An (n,d)-permutation code is a subset C of Sym(n) such that the Hamming distance dH between any two distinct elements of C is at least equal to d. In this paper, we use the characterization of the isometry group of the metric space (Sym(n),dH) in order to develop generating algorithms with rejection of isomorphic objects. To classify the (n,d) -permutation codes up to isometry, we construct invariants and study their efficiency. We give the numbers of nonisometric (4,3) - and (5,4)- permutati...
Measure permutation formulas in Feynman's operational calculi
Chang, K. S.; Kim, B. S.; Park, Y. H.
2010-03-01
In Jefferies-Johnson’s theory of Feynman’s operational calculi for noncommuting operators, the two operators T µ 1,µ 2 f( Ã, tilde B ) and T µ 2,µ1 f( Ã, tilde B ) are not equal. Relationships between these two operators are given, i.e., “measure permutation formulas” in Feynman’s operational calculi are developed; they correspond to the “index permutation formula” in Maslov’s discretized version of Feynman’s operational calculus.
Complete permutation polynomials over finite fields of odd characteristic
Xu, Guangkui; Cao, Xiwang; Tu, Ziran; Zeng, Xiangyong; Hu, Lei
2013-01-01
In this paper, we present three classes of complete permutation monomials over finite fields of odd characteristic. Meanwhile, the compositional inverses of these complete permutation polynomials are also proposed.
Defects and permutation branes in the Liouville field theory
International Nuclear Information System (INIS)
The defects and permutation branes for the Liouville field theory are considered. By exploiting cluster condition, equations satisfied by permutation branes and defects reflection amplitudes are obtained. It is shown that two types of solutions exist, discrete and continuous families.
Defects and permutation branes in the Liouville field theory
DEFF Research Database (Denmark)
Sarkissian, Gor
2009-01-01
The defects and permutation branes for the Liouville field theory are considered. By exploiting cluster condition, equations satisfied by permutation branes and defects reflection amplitudes are obtained. It is shown that two types of solutions exist, discrete and continuous families....
A classification of primitive permutation groups with finite stabilizers
Smith, Simon M.
2011-01-01
We classify all infinite primitive permutation groups possessing a finite point stabilizer, thus extending the seminal Aschbacher-O'Nan-Scott Theorem to all primitive permutation groups with finite point stabilizers.
Defects and Permutation branes in the Liouville field theory
Sarkissian, Gor
2009-01-01
The defects and permutation branes for the Liouville field theory are considered. By exploiting cluster condition, equations satisfied by permutation branes and defects reflection amplitudes are obtained. It is shown that two types of solutions exist, discrete and continuous families.
Permutation Tests for Common Locations among Samples with Unequal Variances.
Mielke, Paul W., Jr.; Berry, Kenneth J.
1994-01-01
Presents permutation procedures that jointly test for differences in location and scale among treatments in a completely randomized experimental design. Also considers extensions to multivariate data and provides efficient alternative permutation tests. (SLD)
On Young tableau involutions and patterns in permutations
Ouchterlony, Erik
2005-01-01
This thesis deals with three different aspects of the combinatorics of permutations. In the first two papers, two flavours of pattern avoiding permutations are examined; and in the third paper Young tableaux, which are closely related to permutations via representation theory, are studied. In the first paper we give solutations to several interesting problems regarding pattern avoiding doubly alternating permutations, such as finding a bijection between 1234-avoiding permutations and 1234-avoiding doubly alternating permutations of twice the size. In the second paper partial permutations which can be extended to pattern avoiding permutations are examined. A general algorithm is presented which is subsequently used to solve many different problems. The third paper deals with involutions on Young tableaux. There is a surprisingly large collection of relations among these involutions and in the paper we make the effort to study them systematically in order to create a coherent theory. The most interesting result...
New results on permutation polynomials over finite fields
Ma, Jingxue; Zhang, Tao; Feng, Tao; Ge, Gennian
2015-01-01
Permutation polynomials over finite fields constitute an active research area and have applications in many areas of science and engineering. In this paper, four classes of monomial complete permutation polynomials and one class of trinomial complete permutation polynomials are presented, one of which confirms a conjecture proposed by Wu et al. (Sci. China Math., to appear. Doi: 10.1007/s11425-014-4964-2). Furthermore, we give two classes of trinomial permutation polynomials, and make some pr...
Complete permutation Gray code implemented by finite state machine
Directory of Open Access Journals (Sweden)
Li Peng
2014-09-01
Full Text Available An enumerating method of complete permutation array is proposed. The list of n! permutations based on Gray code defined over finite symbol set Z(n = {1, 2, …, n} is implemented by finite state machine, named as n-RPGCF. An RPGCF can be used to search permutation code and provide improved lower bounds on the maximum cardinality of a permutation code in some cases.
A bijection to count (1-23-4)-avoiding permutations
Callan, David
2010-01-01
A permutation is (1-23-4)-avoiding if it contains no four entries, increasing left to right, with the middle two adjacent in the permutation. Here we give a 2-variable recurrence for the number of such permutations, improving on the previously known 4-variable recurrence. At the heart of the proof is a bijection from (1-23-4)-avoiding permutations to increasing ordered trees whose leaves, taken in preorder, are also increasing.
Demonstration of quantum permutation algorithm with a single photon ququart
Feiran Wang; Yunlong Wang; Ruifeng Liu; Dongxu Chen; Pei Zhang; Hong Gao; Fuli Li
2015-01-01
We report an experiment to demonstrate a quantum permutation determining algorithm with linear optical system. By employing photon's polarization and spatial mode, we realize the quantum ququart states and all the essential permutation transformations. The quantum permutation determining algorithm displays the speedup of quantum algorithm by determining the parity of the permutation in only one step of evaluation compared with two for classical algorithm. This experiment is accomplished in si...
Energy Technology Data Exchange (ETDEWEB)
Xie, Xiaoyun [National Key Laboratory of Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000 (China); Wang, Zhaowei [College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000 (China); Zhou, Ximin; Wang, Xiaoru [National Key Laboratory of Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Chen, Xingguo, E-mail: chenxg@lzu.edu.cn [National Key Laboratory of Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China)
2011-09-15
Highlights: {center_dot} Molecular docking revealed PAEs to be located in the hydrophobic pocket of HSA. {center_dot} HSA-DMP had one class of binding sites while HSA-BBP and HSA-DEHP had two types. {center_dot} Hydrophobic and hydrogen interactions dominated in the association of HSA-PAEs. {center_dot} The lifetime of Trp residue of HSA decreased after the addition of PAEs. {center_dot} The presences of PAEs could alter the second structure of HSA. - Abstract: Phthalate esters (PAEs) are globally pervasive contaminants that are considered to be endocrine disruptor chemicals and toxic environmental priority pollutants. In this paper, the interactions between PAEs and human serum albumin (HSA) were examined by molecular modelling, steady state and time-resolved fluorescence, ultraviolet-visible spectroscopy (UV-vis) and circular dichroism spectroscopy (CD). The association constants between PAEs and HSA were determined using the Stern-Volmer and Scatchard equations. The binding of dimethyl phthalate (DMP) to HSA has a single class of binding site and its binding constants (K) are 4.08 x 10{sup 3}, 3.97 x 10{sup 3}, 3.45 x 10{sup 3}, and 3.20 x 10{sup 3} L mol{sup -1} at 289, 296, 303, and 310 K, respectively. The Stern-Volmer and Scatchard plots both had two regression curves for HSA-butylbenzyl phthalate (BBP) and HSA-di-2-ethylhexyl phthalate (DEHP), which indicated that these bindings were via two types of binding sites: the numbers of binding site for the first type were lower than for the second type. The binding constants of the first type binding site were higher than those of the second type binding site at corresponding temperatures, the results suggesting that the first type of binding site had high affinity and the second binding site involved other sites with lower binding affinity and selectivity. The thermodynamic parameters of the binding reactions ({Delta}G{sup o}, {Delta}H{sup o} and {Delta}S{sup o}) were measured, and they indicated the presences
International Nuclear Information System (INIS)
Highlights: · Molecular docking revealed PAEs to be located in the hydrophobic pocket of HSA. · HSA-DMP had one class of binding sites while HSA-BBP and HSA-DEHP had two types. · Hydrophobic and hydrogen interactions dominated in the association of HSA-PAEs. · The lifetime of Trp residue of HSA decreased after the addition of PAEs. · The presences of PAEs could alter the second structure of HSA. - Abstract: Phthalate esters (PAEs) are globally pervasive contaminants that are considered to be endocrine disruptor chemicals and toxic environmental priority pollutants. In this paper, the interactions between PAEs and human serum albumin (HSA) were examined by molecular modelling, steady state and time-resolved fluorescence, ultraviolet-visible spectroscopy (UV-vis) and circular dichroism spectroscopy (CD). The association constants between PAEs and HSA were determined using the Stern-Volmer and Scatchard equations. The binding of dimethyl phthalate (DMP) to HSA has a single class of binding site and its binding constants (K) are 4.08 x 103, 3.97 x 103, 3.45 x 103, and 3.20 x 103 L mol-1 at 289, 296, 303, and 310 K, respectively. The Stern-Volmer and Scatchard plots both had two regression curves for HSA-butylbenzyl phthalate (BBP) and HSA-di-2-ethylhexyl phthalate (DEHP), which indicated that these bindings were via two types of binding sites: the numbers of binding site for the first type were lower than for the second type. The binding constants of the first type binding site were higher than those of the second type binding site at corresponding temperatures, the results suggesting that the first type of binding site had high affinity and the second binding site involved other sites with lower binding affinity and selectivity. The thermodynamic parameters of the binding reactions (ΔGo, ΔHo and ΔSo) were measured, and they indicated the presences of hydrophobic forces and hydrogen interactions in the PAEs-HSA interactions, which agreed well with the results
A SAS/IML algorithm for an exact permutation test
Directory of Open Access Journals (Sweden)
Neuhäuser, Markus
2009-03-01
Full Text Available An algorithm written in SAS/IML is presented that can perform an exact permutation test for a two-sample comparison. All possible permutations are considered. The Baumgartner-Weiß-Schindler statistic is exemplarily used as the test statistic for the permutation test.
Permutation-invariant codes encoding more than one qubit
Ouyang, Yingkai; Fitzsimons, Joseph
2015-01-01
A permutation-invariant code on m qubits is a subspace of the symmetric subspace of the m qubits. We derive permutation-invariant codes that can encode an increasing amount of quantum information while suppressing leading order spontaneous decay errors. To prove the result, we use elementary number theory with prior theory on permutation invariant codes and quantum error correction.
The Parameterized Complexity of some Permutation Group Problems
Arvind, Vikraman
2013-01-01
In this paper we study the parameterized complexity of two well-known permutation group problems which are NP-complete. 1. Given a permutation group G=, subgroup of $S_n$, and a parameter $k$, find a permutation $\\pi$ in G such that $|{i\\in [n]\\mid \\pi(i)\
More Classes of Complete Permutation Polynomials over $\\F_q$
Wu, Gaofei; Li, Nian; Helleseth, Tor; Zhang, Yuqing
2013-01-01
In this paper, by using a powerful criterion for permutation polynomials given by Zieve, we give several classes of complete permutation monomials over $\\F_{q^r}$. In addition, we present a class of complete permutation multinomials, which is a generalization of recent work.
Factoring Permutation Matrices Into a Product of Tridiagonal Matrices
Samson, Michael Daniel; Ezerman, Martianus Frederic
2010-01-01
Gilbert Strang posited that a permutation matrix of bandwidth $w$ can be written as a product of $N < 2w$ permutation matrices of bandwidth 1. A proof employing a greedy ``parallel bubblesort'' algorithm on the rows of the permutation matrix is detailed and further points of interest are elaborated.
Further Results on Permutation Polynomials over Finite Fields
Yuan, Pingzhi; Ding, Cunsheng
2013-01-01
Permutation polynomials are an interesting subject of mathematics and have applications in other areas of mathematics and engineering. In this paper, we develop general theorems on permutation polynomials over finite fields. As a demonstration of the theorems, we present a number of classes of explicit permutation polynomials on $\\gf_q$.
Permutation trinomials over finite fields with even characteristic
Ding, Cunsheng; Qu, Longjiang; WANG Qiang; Yuan, Jin; Yuan, Pingzhi
2014-01-01
Permutation polynomials have been a subject of study for a long time and have applications in many areas of science and engineering. However, only a small number of specific classes of permutation polynomials are described in the literature so far. In this paper we present a number of permutation trinomials over finite fields, which are of different forms.
Permutation-invariant codes encoding more than one qubit
Ouyang, Yingkai; Fitzsimons, Joseph
2016-04-01
A permutation-invariant code on m qubits is a subspace of the symmetric subspace of the m qubits. We derive permutation-invariant codes that can encode an increasing amount of quantum information while suppressing leading-order spontaneous decay errors. To prove the result, we use elementary number theory with prior theory on permutation-invariant codes and quantum error correction.
Flavour singlets in gauge theory as Permutations
Kimura, Yusuke; Suzuki, Ryo
2016-01-01
Gauge-invariant operators can be specified by equivalence classes of permutations. We develop this idea concretely for the singlets of the flavour group $SO(N_f)$ in $U(N_c)$ gauge theory by using Gelfand pairs and Schur-Weyl duality. The singlet operators, when specialised at $N_f =6$, belong to the scalar sector of ${\\cal N}=4$ SYM. A simple formula is given for the two-point functions in the free field limit of $g_{YM}^2 =0$. The free two-point functions are shown to be equal to the partition function on a 2-complex with boundaries and a defect, in a topological field theory of permutations. The permutation equivalence classes are Fourier transformed to a representation basis which is orthogonal for the two-point functions at finite $N_c , N_f$. Counting formulae for the gauge-invariant operators are described. The one-loop mixing matrix is derived as a linear operator on the permutation equivalence classes.
Simple current extensions and the permutation orbifold
International Nuclear Information System (INIS)
We review extensions by integer spin simple currents in two-dimensional conformal field theories and their application in string theory. In particular, we study the problem of resolving the fixed points of a simple current and apply the formalism to the permutation orbifold.
Weak mixing matrix under permutation symmetry breaking
International Nuclear Information System (INIS)
The two-Higgs-doublet extension of the standard electroweak model is considered. A permutation symmetry-breaking scheme is proposed and used to calculate the weak mixing matrix up to second order. The CP-violation factor J and the correction to Bjorken's approximation are then given. A special case is considered
Permutation orbifolds of heterotic Gepner models
International Nuclear Information System (INIS)
We study orbifolds by permutations of two identical N=2 minimal models within the Gepner construction of four-dimensional heterotic strings. This is done using the new N=2 supersymmetric permutation orbifold building blocks we have recently developed. We compare our results with the old method of modding out the full string partition function. The overlap between these two approaches is surprisingly small, but whenever a comparison can be made we find complete agreement. The use of permutation building blocks allows us to use the complete arsenal of simple current techniques that is available for standard Gepner models, vastly extending what could previously be done for permutation orbifolds. In particular, we consider (0,2) models, breaking of SO(10) to subgroups, weight-lifting for the minimal models and B-L lifting. Some previously observed phenomena, for example concerning family number quantization, extend to this new class as well, and in the lifted models three-family models occur with abundance comparable to two or four.
The L-sharp permutation groups
Institute of Scientific and Technical Information of China (English)
李炯生
2000-01-01
An answer is given to a problem proposed by Bannai and Ito for { l, l + s, l + s + t} -sharp permutation group, and the result is used to determine L-sharp groups for L = { l, l + 1, l + 3} and{l,l+2,l+3}.
Permutation Tests for Stochastic Ordering and ANOVA
Basso, Dario; Salmaso, Luigi; Solari, Aldo
2009-01-01
Permutation testing for multivariate stochastic ordering and ANOVA designs is a fundamental issue in many scientific fields such as medicine, biology, pharmaceutical studies, engineering, economics, psychology, and social sciences. This book presents advanced methods and related R codes to perform complex multivariate analyses
LucY: A Versatile New Fluorescent Reporter Protein.
Directory of Open Access Journals (Sweden)
Michele E Auldridge
Full Text Available We report on the discovery, isolation, and use of a novel yellow fluorescent protein. Lucigen Yellow (LucY binds one FAD molecule within its core, thus shielding it from water and maintaining its structure so that fluorescence is 10-fold higher than freely soluble FAD. LucY displays excitation and emission spectra characteristic of FAD, with 3 excitation peaks at 276 nm, 377 nm, and 460 nm and a single emission peak at 530 nm. These excitation and emission maxima provide the large Stokes shift beneficial to fluorescence experimentation. LucY belongs to the MurB family of UDP-N-acetylenolpyruvylglucosamine reductases. The high resolution crystal structure shows that in contrast to other structurally resolved MurB enzymes, LucY does not contain a potentially quenching aromatic residue near the FAD isoalloxazine ring, which may explain its increased fluorescence over related proteins. Using E. coli as a system in which to develop LucY as a reporter, we show that it is amenable to circular permutation and use as a reporter of protein-protein interaction. Fragmentation between its distinct domains renders LucY non-fluorescent, but fluorescence can be partially restored by fusion of the fragments to interacting protein domains. Thus, LucY may find application in Protein-fragment Complementation Assays for evaluating protein-protein interactions.
Five Constructions of Permutation Polynomials over $\\gf(q^2)$
Ding, Cunsheng; Yuan, Pingzhi
2015-01-01
Four recursive constructions of permutation polynomials over $\\gf(q^2)$ with those over $\\gf(q)$ are developed and applied to a few famous classes of permutation polynomials. They produce infinitely many new permutation polynomials over $\\gf(q^{2^\\ell})$ for any positive integer $\\ell$ with any given permutation polynomial over $\\gf(q)$. A generic construction of permutation polynomials over $\\gf(2^{2m})$ with o-polynomials over $\\gf(2^m)$ is also presented, and a number of new classes of per...
International Nuclear Information System (INIS)
Information circulars are published from time to time under the symbol INFCIRC/. . . . for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A list of the circulars which were of current interest on 15 January 1969 is given below, followed by an index to their subject matter. Other circulars can be traced by reference to earlier issues of the present document.
Permutation Analysis of Track and Column Braiding
Institute of Scientific and Technical Information of China (English)
李毓陵; 丁辛; 胡良剑
2004-01-01
The positions of braiding carrier in track and column braiding are represented by a diagrammatic braiding plan and a corresponding lattice-array is defined. A set is then formed so that the permutation analysis can be performed to represent the movement of carriers in a braiding process. The process of 4-step braiding is analyzed as an example to describe the application of the proposed method by expressing a braiding cycle as a product of disjoint cycles. As a result, a mapping relation between the disjoint cycles and the movement of carriers is deduced. Following the same analysis principles, a process of 8-step braiding and the corresponding initial state of the lattice-array is developed. A successful permutation analysis to the process manifests the general suitability of the proposed method.
High order generalized permutational fractional Fourier transforms
Institute of Scientific and Technical Information of China (English)
Ran Qi-Wen; Yuan Lin; Tan Li-Ying; Ma Jing; Wang Qi
2004-01-01
We generalize the definition of the fractional Fourier transform (FRFT) by extending the new definition proposed by Shih. The generalized FRFT, called the high order generalized permutational fractional Fourier transform (HGPFRFT),is a generalized permutational transform. It is shown to have arbitrary natural number M periodic eigenvalues not only with respect to the order of Hermite-Gaussian functions but also to the order of the transform. This HGPFRFT will be reduced to the original FRFT proposed by Namias and Liu's generalized FRFT and Shih's FRFT at the three limits with M = +∞,M = 4k (k is a natural number), and M = 4, respectively. Therefore the HGPFRFT introduces a comprehensive approach to Shih's FRFT and the original definition. Some important properties of HGPFRFT are discussed. Lastly the results of computer simulations and symbolic representations of the transform are provided.
High order generalized permutational fractional Fourier transforms
Ran, Qi-Wen; Yuan, Lin; Tan, Li-Ying; Ma, Jing; Wang, Qi
2004-02-01
We generalize the definition of the fractional Fourier transform (FRFT) by extending the new definition proposed by Shih. The generalized FRFT, called the high order generalized permutational fractional Fourier transform (HGPFRFT), is a generalized permutational transform. It is shown to have arbitrary natural number M periodic eigenvalues not only with respect to the order of Hermite-Gaussian functions but also to the order of the transform. This HGPFRFT will be reduced to the original FRFT proposed by Namias and Liu's generalized FRFT and Shih's FRFT at the three limits with M = +infty, M = 4k (k is a natural number) and M = 4, respectively. Therefore the HGPFRFT introduces a comprehensive approach to Shih's FRFT and the original definition. Some important properties of HGPFRFT are discussed. Lastly the results of computer simulations and symbolic representations of the transform are provided.
Commutative Hopf algebras of permutations and trees
Hivert, F.; Novelli, J. -C.; Thibon, J. -Y.
2005-01-01
We propose several constructions of commutative or cocommutative Hopf algebras based on various combinatorial structures, and investigate the relations between them. A commutative Hopf algebra of permutations is obtained by a general construction based on graphs, and its non-commutative dual is realized in three different ways, in particular as the Grossman-Larson algebra of heap ordered trees. Extensions to endofunctions, parking functions, set partitions, planar binary trees and rooted fore...
Charge quantum numbers and permutation symmetry
International Nuclear Information System (INIS)
An introduction to the N identical particles problem for two classes of particle types, e.g., bosons and fermions, is made. Particles indistinguishability is discussed, inserting the unitary representation of the permutation group concept. Others possibilities for classes of particles in terms of parastatistics, are discussed. A relation between charge quantum numbers and gauge groups in lagrangean field theory, is made. Structural analysis of the superselection rules in elementary particle physics, are also discussed
Faster permutation inference in brain imaging.
Winkler, AM; Ridgway, GR; Douaud, G; Nichols, TE; Smith, SM
2016-01-01
Permutation tests are increasingly being used as a reliable method for inference in neuroimaging analysis. However, they are computationally intensive. For small, non-imaging datasets, recomputing a model thousands of times is seldom a problem, but for large, complex models this can be prohibitively slow, even with the availability of inexpensive computing power. Here we exploit properties of statistics used with the general linear model (GLM) and their distributions to obtain accelerations i...
The topology of the permutation pattern poset
McNamara, Peter; Steingrımsson, Einar
2014-01-01
International audience The set of all permutations, ordered by pattern containment, forms a poset. This extended abstract presents the first explicit major results on the topology of intervals in this poset. We show that almost all (open) intervals in this poset have a disconnected subinterval and are thus not shellable. Nevertheless, there seem to be large classes of intervals that are shellable and thus have the homotopy type of a wedge of spheres. We prove this to be the case for all in...
Using Permutation Tests in Multiple Correlation Investigation
Stelmach, Jacek
2012-01-01
An indication of correlation between dependent variable and predictors is a crucial point in building statistical regression model. The test of Pearson correlation coefficient – with relatively good power – needs to fulfill the assumption about normal distribution. In other cases only non-parametric tests can be used. This article presents a possibility and advantages of permutation tests with the discussion about proposed test statistics. The power of proposed tests was estima...
The Shard Intersection Order on Permutations
Bancroft, Erin
2011-01-01
The shard intersection order is a new lattice structure on a finite Coxeter group W which encodes the geometry of the reflection arrangement and the lattice theory of the weak order. In the case where W is the symmetric group, we characterize shard intersections as certain pre-orders which we call permutation pre-orders. We use this combinatorial characterization to determine properties of the shard intersection order. In particular, we give an EL-labeling.
International Nuclear Information System (INIS)
Information circulars are published from time to time under the symbol INFCIRC/... for the purpose of bringing matters of general interest to the attention of all Members of the Agency. The present revision contains INFCIRCs published up to mid-August 1994. A complete numerical list of information circulars is reproduced with their titles in the Annex
International Nuclear Information System (INIS)
The document summarizes the Information Circulars published by the IAEA for the purpose of bringing matters of general interest to the attention of all Members of the Agency. This revision contains INFCIRCs published up to mid-August 1992. A complete numerical lift of Information Circulars with their titles is reproduced in an Annex
International Nuclear Information System (INIS)
The document summarizes the Information Circulars published by the IAEA for the purpose of bringing matters of general interest to the attention of all Member States. This revision contains INFCIRCs published up to the end of May 1999, grouped by field of activity. A complete list of information circulars in numerical order is given in an annex
International Nuclear Information System (INIS)
Information circulars are published from time to time under the symbol INFCIRC/. for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A list of the circulars that were current on 31 December 1964 is given, followed by an index to their subject matter.
International Nuclear Information System (INIS)
The document summarizes the Information Circulars published by the IAEA for the purpose of bringing matters of general interest to the attention of all Member States. This revision contains INFCIRCs published up to February 1997, grouped by field of activity. A complete list of information circulars in numerical order is given in an annex
International Nuclear Information System (INIS)
Information circulars are published from time to time under the symbol INFCIRC/... for the purpose of bringing matters of general interest to the attention of all Members of the Agency. The present revision contains INFCIRCs published up to the end of April 2002. A complete numerical list of information circulars is reproduced with their titles in the Annex
On Straight Words and Minimal Permutators in Finite Transformation Semigroups
Egri-Nagy, Attila
2010-01-01
Motivated by issues arising in computer science, we investigate the loop-free paths from the identity transformation and corresponding straight words in the Cayley graph of a finite transformation semigroup with a fixed generator set. Of special interest are words that permute a given subset of the state set. Certain such words, called minimal permutators, are shown to comprise a code, and the straight ones comprise a finite code. Thus, words that permute a given subset are uniquely factorizable as products of the subset's minimal permutators, and these can be further reduced to straight minimal permutators. This leads to insight into structure of local pools of reversibility in transformation semigroups in terms of the set of words permuting a given subset. These findings can be exploited in practical calculations for hierarchical decompositions of finite automata. As an example we consider groups arising in biological systems.
On Straight Words and Minimal Permutators in Finite Transformation Semigroups
Egri-Nagy, Attila; Nehaniv, Chrystopher L.
Motivated by issues arising in computer science, we investigate the loop-free paths from the identity transformation and corresponding straight words in the Cayley graph of a finite transformation semigroup with a fixed generator set. Of special interest are words that permute a given subset of the state set. Certain such words, called minimal permutators, are shown to comprise a code, and the straight ones comprise a finite code. Thus, words that permute a given subset are uniquely factorizable as products of the subset's minimal permutators, and these can be further reduced to straight minimal permutators. This leads to insight into structure of local pools of reversibility in transformation semigroups in terms of the set of words permuting a given subset. These findings can be exploited in practical calculations for hierarchical decompositions of finite automata. As an example we consider groups arising in biological systems.
Analysis of cubic permutation polynomials for turbo codes
Trifina, Lucian
2011-01-01
Quadratic permutation polynomials (QPPs) have been widely studied and used as interleavers in turbo codes. However, less attention has been given to cubic permutation polynomials (CPPs). This paper proves a theorem which states sufficient and necessary conditions for a cubic permutation polynomial to be a null permutation polynomial. The result is used to reduce the search complexity of CPP interleavers for short lengths (multiples of 8, between 40 and 256), by improving the distance spectrum over the set of polynomials with the largest spreading factor. The comparison with QPP interleavers is made in terms of search complexity and upper bounds of the bit error rate (BER) and frame error rate (FER) for AWGN channel. Cubic permutation polynomials leading to better performance than quadratic permutation polynomials are found for some lengths.
Self-Dual Permutation Codes over Finite Chain Rings
Institute of Scientific and Technical Information of China (English)
YUAN Yuan; ZHANG Huanguo
2007-01-01
Permutation codes over finite chain rings are introduced; by using the character of the finite chain rings and the knowledge of representation of group, some conditions for existence or non-existence of self-dual permutation codes over finite chain rings are obtained. Specially, when the group is a direct product ora 2-group and a 2'-group, and the group action is transitive, the sufficient and necessary condition of the existence of permutation codes is given.
Parity-Alternate Permutations and Signed Eulerian Numbers
Tanimoto, Shinji
2006-01-01
In order to study signed Eulerian numbers, we introduce permutations of a particular type, called parity-alternate permutations, because they take even and odd entries alternately. The objective of this paper is twofold. The first is to derive several properties of those permutations, by subdividing them into even and odd ones. The second is to discuss relationships between those and signed Eulerian numbers. Divisibility properties by prime powers are also deduced for signed Eulerian numbers ...
Permutation orbifolds of N=2 supersymmetric minimal models
International Nuclear Information System (INIS)
In this paper we apply the previously derived formalism of permutation orbifold conformal field theories to N=2 supersymmetric minimal models. By interchanging extensions and permutations of the factors we find a very interesting structure relating various conformal field theories that seems not to be known in literature. Moreover, unexpected exceptional simple currents arise in the extended permuted models, coming from off-diagonal fields. In a few situations they admit fixed points that must be resolved. We determine the complete CFT data with all fixed point resolution matrices for all simple currents of all Z2-permutations orbifolds of all minimal N=2 models with k≠2mod4.
A W[1]-completeness result for permutation pattern matching
Bruner, Marie-Louise
2011-01-01
The NP-complete Permutation Pattern Matching problem asks whether a permutation P (the pattern) can be matched into a permutation T (the text). A matching is an order-preserving embedding of P into T. This paper studies the parameterized complexity of Permutation Pattern Matching. We show that this problem is W[1]-complete with respect to the length of the pattern P. Under standard complexity theoretic assumptions this implies that no fixed-parameter tractable algorithm can be found for any parameter depending solely on P.
National Oceanic and Atmospheric Administration, Department of Commerce — Circular Updates are periodic sequentially numbered instructions to debriefing staff and observers informing them of changes or additions to scientific and specimen...
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The document summarizes the information circulars published by the IAEA for the purpose of bringing matters of general interest to the attention of all Members of the Agency. In the main body of the document only those documents which are regarded as likely to be of current interest are listed. A complete numerical list of information circulars with their titles is reproduced in the Annex
Permutation Entropy for Random Binary Sequences
Directory of Open Access Journals (Sweden)
Lingfeng Liu
2015-12-01
Full Text Available In this paper, we generalize the permutation entropy (PE measure to binary sequences, which is based on Shannon’s entropy, and theoretically analyze this measure for random binary sequences. We deduce the theoretical value of PE for random binary sequences, which can be used to measure the randomness of binary sequences. We also reveal the relationship between this PE measure with other randomness measures, such as Shannon’s entropy and Lempel–Ziv complexity. The results show that PE is consistent with these two measures. Furthermore, we use PE as one of the randomness measures to evaluate the randomness of chaotic binary sequences.
Permutation-invariant distance between atomic configurations
International Nuclear Information System (INIS)
We present a permutation-invariant distance between atomic configurations, defined through a functional representation of atomic positions. This distance enables us to directly compare different atomic environments with an arbitrary number of particles, without going through a space of reduced dimensionality (i.e., fingerprints) as an intermediate step. Moreover, this distance is naturally invariant through permutations of atoms, avoiding the time consuming associated minimization required by other common criteria (like the root mean square distance). Finally, the invariance through global rotations is accounted for by a minimization procedure in the space of rotations solved by Monte Carlo simulated annealing. A formal framework is also introduced, showing that the distance we propose verifies the property of a metric on the space of atomic configurations. Two examples of applications are proposed. The first one consists in evaluating faithfulness of some fingerprints (or descriptors), i.e., their capacity to represent the structural information of a configuration. The second application concerns structural analysis, where our distance proves to be efficient in discriminating different local structures and even classifying their degree of similarity
Permutation-invariant distance between atomic configurations
Energy Technology Data Exchange (ETDEWEB)
Ferré, Grégoire; Maillet, Jean-Bernard [CEA, DAM, DIF, F-91297 Arpajon (France); Stoltz, Gabriel [Université Paris-Est, CERMICS (ENPC), INRIA, F-77455 Marne-la-Vallée (France)
2015-09-14
We present a permutation-invariant distance between atomic configurations, defined through a functional representation of atomic positions. This distance enables us to directly compare different atomic environments with an arbitrary number of particles, without going through a space of reduced dimensionality (i.e., fingerprints) as an intermediate step. Moreover, this distance is naturally invariant through permutations of atoms, avoiding the time consuming associated minimization required by other common criteria (like the root mean square distance). Finally, the invariance through global rotations is accounted for by a minimization procedure in the space of rotations solved by Monte Carlo simulated annealing. A formal framework is also introduced, showing that the distance we propose verifies the property of a metric on the space of atomic configurations. Two examples of applications are proposed. The first one consists in evaluating faithfulness of some fingerprints (or descriptors), i.e., their capacity to represent the structural information of a configuration. The second application concerns structural analysis, where our distance proves to be efficient in discriminating different local structures and even classifying their degree of similarity.
2003-01-01
Operational Circular N° 4 - April 2003 Conditions for use by members of the CERN personnel of vehicles belonging to or rented by CERN - This circular has been drawn up. Operational Circular N° 5 - October 2000 Use of CERN computing facilities - Further details on the personal use of CERN computing facilities Operational Circular N° 5 and its Subsidiary Rules http://cern.ch/ComputingRules defines the rules for the use of CERN computing facilities. One of the basic principles governing such use is that it must come within the professional duties of the user concerned, as defined by the user's divisional hierarchy. However, personal use of the computing facilities is tolerated or allowed provided : a) It is in compliance with Operational Circular N° 5 and not detrimental to official duties, including those of other users; b) the frequency and duration is limited and there is a negligible use of CERN resources; c) it does not constitute a political, commercial and/or profit-making activity; d) it is not...
Fast Algorithm for Solution of r-Permutation Factor Circulant Linear Systems
HE Cheng-yuan; CHEN, YONG
2010-01-01
In this paper, r-permutation factor circulant matrix is defined based on the permutation factor circulant matrix , and a fast algorithm for conditions of solution and solution of r-permutation factor circulant matrix linear equations AX=b are presented. When r-permutation factor circulant matrix are nonsingular, this algorithm computes the single solution of r-permutation factor circulant matrix linear equations , that is , there exists a unique r-permutation factor circulant matrix*, which t...
On the Two-Body Permutation-Parity Combinatorial Transformation
Yu, Hai-jun; Du, Jian-ming; Ren, Gang
2015-10-01
Based on the coherent entangled state representation we find a new unitary operator which plays role of two-body permutation-parity combinatorial transformation. We employ the method of integration within ordered product of operators to derive this operator, its explicit form and normally ordered form are both obtained. The unitary operator for permutation-parity-squeezing combinatorial transformation is also obtained.
Permutation sign under the Robinson-Schensted-Knuth correspondence
Reifegerste, Astrid
2003-01-01
We show how the sign of a permutation can be deduced from the tableaux induced by the permutation under the Robinson-Schensted-Knuth correspondence. The result yields a simple proof of a conjecture on the squares of imbalances raised by Stanley.
On the effective and automatic enumeration of polynomial permutation classes
Homberger, Cheyne; Vatter, Vince
2013-01-01
We describe an algorithm, implemented in Python, which can enumerate any permutation class with polynomial enumeration from a structural description of the class. In particular, this allows us to find formulas for the number of permutations of length n which can be obtained by a finite number of block sorting operations (e.g., reversals, block transpositions, cut-and-paste moves).
M\\'enage Numbers and M\\'enage Permutations
Li, Yiting
2015-01-01
In this paper, we study the combinatorial structures of straight and ordinary m\\'enage permutations. Based on these structures, we prove four formulas. The first two formulas define a relationship between the m\\'enage numbers and the Catalan numbers. The other two formulas count the m\\'enage permutations by number of cycles.
Simple permutations of the classes Av(321, 13524) and Av(321, 13452) have polynomial growth
Lutful Karim; Nargis Khan
2011-01-01
A permutation is called simple if its only blocks i.e. subsets of the permutation consist of singleton and the permutation itself. For example, 2134 is not a simple permutation since it consists ofa block 213 but 3142 is a simple permutation. The basis of a permutation is a pattern which is minimal under involvement and do not belong to the permutation. In this paper, we prove that the number of simple permutations an of the pattern class with two basis of length 3 and 5 such as Av(321, 13452...
A Fuzzy Permutation Method for False Discovery Rate Control.
Yang, Ya-Hui; Lin, Wan-Yu; Lee, Wen-Chung
2016-01-01
Biomedical researchers often encounter the large-p-small-n situations-a great number of variables are measured/recorded for only a few subjects. The authors propose a fuzzy permutation method to address the multiple testing problem for small sample size studies. The method introduces fuzziness into standard permutation analysis to produce randomized p-values, which are then converted into q-values for false discovery rate controls. Simple algebra shows that the fuzzy permutation method is at least as powerful as the standard permutation method under any alternative. Monte-Carlo simulations show that the proposed method has desirable statistical properties whether the study variables are normally or non-normally distributed. A real dataset is analyzed to illustrate its use. The proposed fuzzy permutation method is recommended for use in the large-p-small-n settings. PMID:27328860
International Nuclear Information System (INIS)
The document summarizes the Information Circulars published by the IAEA under the symbol INFCIRC/ for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A complete list of INFCIRCs in numerical order with their titles is given in the Annex
Permutation Symmetry Determines the Discrete Wigner Function
Zhu, Huangjun
2016-01-01
The Wigner function provides a useful quasiprobability representation of quantum mechanics, with applications in various branches of physics. Many nice properties of the Wigner function are intimately connected with the high symmetry of the underlying operator basis composed of phase point operators: any pair of phase point operators can be transformed to any other pair by a unitary symmetry transformation. We prove that, in the discrete scenario, this permutation symmetry is equivalent to the symmetry group being a unitary 2 design. Such a highly symmetric representation can only appear in odd prime power dimensions besides dimensions 2 and 8. It suffices to single out a unique discrete Wigner function among all possible quasiprobability representations. In the course of our study, we show that this discrete Wigner function is uniquely determined by Clifford covariance, while no Wigner function is Clifford covariant in any even prime power dimension.
The Fractional Metric Dimension of Permutation Graphs
Institute of Scientific and Technical Information of China (English)
Eunjeong YI
2015-01-01
Let G = (V (G), E(G)) be a graph with vertex set V (G) and edge set E(G). For two distinct vertices x and y of a graph G, let RG{x, y}denote the set of vertices z such that the distance from x to z is not equal to the distance from y to z in G. For a function g defined on V (G) and for U ⊆V (G), let g(U )=? s∈U g(s). A real-valued function g:V (G)→[0, 1] is a resolving function of G if g(RG{x, y})≥1 for any two distinct vertices x, y∈V (G). The fractional metric dimension dimf (G) of a graph G is min{g(V (G)):g is a resolving function of G}. Let G1 and G2 be disjoint copies of a graph G, and let σ : V (G1) → V (G2) be a bijection. Then, a permutation graph Gσ = (V,E) has the vertex set V = V (G1)∪V (G2) and the edge set E = E(G1)∪E(G2)∪{uv|v = σ(u)}. First, we determine dimf (T ) for any tree T . We show that 1 0, there exists a permutation graph Gσ such that dimf (Gσ)−1dimf (Gσ) for all pairs (G,σ). Furthermore, we investigate dimf (Gσ) when G is a complete k-partite graph or a cycle.
Modified permutation-entropy analysis of heartbeat dynamics
Bian, Chunhua; Qin, Chang; Ma, Qianli D. Y.; Shen, Qinghong
2012-02-01
Heart rate variability (HRV) contains important information about the modulation of the cardiovascular system. Various methods of nonlinear dynamics (e.g., estimating Lyapunov exponents) and complexity measures (e.g., correlation dimension or entropies) have been applied to HRV analysis. Permutation entropy, which was proposed recently, has been widely used in many fields due to its conceptual and computational simplicity. It maps a time series onto a symbolic sequence of permutation ranks. The original permutation entropy assumes the time series under study has a continuous distribution, thus equal values are rare and can be ignored by ranking them according to their order of emergence, or broken by adding small random perturbations to ensure every symbol in a sequence is different. However, when the observed time series is digitized with lower resolution leading to a greater number of equal values, or the equalities represent certain characteristic sequential patterns of the system, it may not be rational to simply ignore or break them. In the present paper, a modified permutation entropy is proposed that, by mapping the equal value onto the same symbol (rank), allows for a more accurate characterization of system states. The application of the modified permutation entropy to the analysis of HRV is investigated using clinically collected data. Results show that modified permutation entropy can greatly improve the ability to distinguish the HRV signals under different physiological and pathological conditions. It can characterize the complexity of HRV more effectively than the original permutation entropy.
Division des ressources humaines
2000-01-01
N° 2 (Rev. 1) - March 2000Guidelines and procedures concerning recruitment and probation period of staff membersN° 9 (Rev. 2) - March 2000Staff members contractsN° 16 (Rev. 2) - January 2000TrainingN° 30 (Rev. 1) - January 2000Indemnities and reimbursements upon taking up appointment and termination of contractN° 32 - February 2000Principles and procedures governing complaints of harassmentThese circular have been amended (No 2, N° 9, N° 16 and N° 30) or drawn up (N° 32).Copies are available in the Divisional Secretariats.Note:\tAdministrative and operational circulars, as well as the lists of those in force, are available for consultation in the server SRV4_Home in the Appletalk zone NOVELL (as GUEST or using your Novell username and password), volume PE Division Data Disk.The Word files are available in the folder COM, folder Public, folder ADM.CIRC.docHuman Resources DivisionTel. 74128
r-BlockPermutation Factor Circulant Matrix and Inverse Matrix
SUN Ji zhong; QIN Keyun; Hu, Yan
2012-01-01
The concept of r-block permutation factor circulant matrix is presented. The characteristics of r-block permutation factor circulant matrix are discussed by Kronecker. The interchange ability of r-block permutation factor circulant matrix has been demonstrated, that is AB=BA. The calculation method of matrix determinant and the sufficient condition of nonsingular matrix based on the diagonalization of circulant matrices are given. Finally, the method of inverse matrix is given in r-blo...
An Erd\\H{o}s--Hajnal analogue for permutation classes
Vatter, Vincent
2015-01-01
Let $\\mathcal{C}$ be a permutation class that does not contain all layered permutations or all colayered permutations. We prove that there is a constant $c$ such that every permutation in $\\mathcal{C}$ of length $n$ contains a monotone subsequence of length $cn$.
A Random Variable Related to the Inversion Vector of a Partial Random Permutation
Laghate, Kavita; Deshpande, M. N.
2005-01-01
In this article, we define the inversion vector of a permutation of the integers 1, 2,..., n. We set up a particular kind of permutation, called a partial random permutation. The sum of the elements of the inversion vector of such a permutation is a random variable of interest.
Permutation based decision making under fuzzy environment using Tabu search
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Mahdi Bashiri
2012-04-01
Full Text Available One of the techniques, which are used for Multiple Criteria Decision Making (MCDM is the permutation. In the classical form of permutation, it is assumed that weights and decision matrix components are crisp. However, when group decision making is under consideration and decision makers could not agree on a crisp value for weights and decision matrix components, fuzzy numbers should be used. In this article, the fuzzy permutation technique for MCDM problems has been explained. The main deficiency of permutation is its big computational time, so a Tabu Search (TS based algorithm has been proposed to reduce the computational time. A numerical example has illustrated the proposed approach clearly. Then, some benchmark instances extracted from literature are solved by proposed TS. The analyses of the results show the proper performance of the proposed method.
Formula for fixed point resolution matrix of permutation orbifolds
International Nuclear Information System (INIS)
We find a formula for the resolution of fixed points in extensions of permutation orbifold conformal field theories by its (half-)integer spin simple currents. We show that the formula gives a unitary and modular invariant S matrix.
Permutation Orbifolds in Conformal Field Theories and String Theory
2011-01-01
We summarize the results obtained in the last few years about permutation orbifolds in two-dimensional conformal field theories, their application to string theory and their use in the construction of four-dimensional heterotic string models.
Dynamic Permutational Isomerism in a closo-Cluster.
Fu, Junhong; Morshedi, Mahbod; Moxey, Graeme J; Barlow, Adam; Cifuentes, Marie P; Humphrey, Mark G
2016-04-01
Permutational isomers of trigonal bipyramidal [W2 RhIr2 (CO)9 (η(5) -C5 H5 )2 (η(5) -C5 HMe4 )] result from competitive capping of either a W2 Ir or a WIr2 face of the tetrahedral cluster [W2 Ir2 (CO)10 (η(5) -C5 H5 )2 ] from its reaction with [Rh(CO)2 (η(5) -C5 HMe4 )]. The permutational isomers slowly interconvert in solution by a cluster metal vertex exchange that is proposed to proceed by Rh-Ir and Rh-W bond cleavage and reformation, and via the intermediacy of an edge-bridged tetrahedral transition state. The permutational isomers display differing chemical and physical properties: replacement of CO by PPh3 occurs at one permutational isomer only, while the isomers display distinct optical power limiting behavior. PMID:26868979
Multiscale Permutation Entropy Based Rolling Bearing Fault Diagnosis
Jinde Zheng; Junsheng Cheng; Yu Yang
2014-01-01
A new rolling bearing fault diagnosis approach based on multiscale permutation entropy (MPE), Laplacian score (LS), and support vector machines (SVMs) is proposed in this paper. Permutation entropy (PE) was recently proposed and defined to measure the randomicity and detect dynamical changes of time series. However, for the complexity of mechanical systems, the randomicity and dynamic changes of the vibration signal will exist in different scales. Thus, the definition of MPE is introduced and...
Permutation Polynomials of Degree 6 or 7 over Finite Fields of Characteristic 2
Li, Jiyou; Chandler, David B.; Xiang, Qing
2010-01-01
In \\cite{D1}, Dickson listed all permutation polynomials up to degree 5 over an arbitrary finite field, and all permutation polynomials of degree 6 over finite fields of odd characteristic. The classification of degree 6 permutation polynomials over finite fields of characteristic 2 was left incomplete. In this paper we complete the classification of permutation polynomials of degree 6 over finite fields of characteristic 2. In addition, all permutation polynomials of degree 7 over finite fie...
Some illustrative examples of permutability of fuzzy operators and fuzzy relations
Bragard, J.; Recasens-Ferres, J. (Jorge); Elorza-Barbajero, J. (Jorge); Carmona-Cervelló, N. (Neus)
2014-01-01
Composition of fuzzy operators often appears and it is natural to ask when the order of composition does not change the result. In previous papers, we characterized permutability in the case of fuzzy consequence operators and fuzzy interior operators. We also showed the connection between the permutability of the fuzzy relations and the permutability of their induced fuzzy operators. In this work we present some examples of permutability and non permutability of fuzzy operators and fuzzy rela...
Permutation Polynomials of Degree 6 or 7 over Finite Fields of Characteristic 2
Li, Jiyou; Xiang, Qing
2010-01-01
In \\cite{D1}, Dickson listed all permutation polynomials up to degree 5 over an arbitrary finite field, and all permutation polynomials of degree 6 over finite fields of odd characteristic. The classification of degree 6 permutation polynomials over finite fields of characteristic 2 was left incomplete. In this paper we complete the classification of permutation polynomials of degree 6 over finite fields of characteristic 2. In addition, all permutation polynomials of degree 7 over finite fields of characteristic 2 are classified.
On permutation-twisted free fermions and two conjectures
International Nuclear Information System (INIS)
We conjecture that the category of permutation-twisted modules for a multi-fold tensor product vertex operator superalgebra and a cyclic permutation of even order is isomorphic to the category of parity-twisted modules for the underlying vertex operator superalgebra. This conjecture is based on our observations of the cyclic permutation-twisted modules for free fermions as we discuss in this work, as well as previous work of the first author constructing and classifying permutation-twisted modules for tensor product vertex operator superalgebras and a permutation of odd order. In addition, we observe that the transposition isomorphism for two free fermions corresponds to a lift of the −1 isometry of the integral lattice vertex operator superalgebra corresponding to two free fermions under boson-fermion correspondence. We conjecture that all even order cyclic permutation automorphisms of free fermions can be realized as lifts of lattice isometries under boson-fermion correspondence. We discuss the role of parity stability in the construction of these twisted modules and prove that in general, parity-unstable weak twisted modules for a vertex operator superalgebras come in pairs that form orthogonal invariant subspaces of parity-stable weak twisted modules, clarifying their role in many other settings
A Comparative Study on the Performance of Permutation Algorithms
Bassil, Youssef
2012-01-01
Permutation is the different arrangements that can be made with a given number of things taking some or all of them at a time. The notation P(n,r) is used to denote the number of permutations of n things taken r at a time. Permutation is used in various fields such as mathematics, group theory, statistics, and computing, to solve several combinatorial problems such as the job assignment problem and the traveling salesman problem. In effect, permutation algorithms have been studied and experimented for many years now. Bottom-Up, Lexicography, and Johnson-Trotter are three of the most popular permutation algorithms that emerged during the past decades. In this paper, we are implementing three of the most eminent permutation algorithms, they are respectively: Bottom-Up, Lexicography, and Johnson-Trotter algorithms. The implementation of each algorithm will be carried out using two different approaches: brute-force and divide and conquer. The algorithms codes will be tested using a computer simulation tool to mea...
Optical brush: Imaging through permuted probes
Heshmat, Barmak; Lee, Ik Hyun; Raskar, Ramesh
2016-02-01
The combination of computational techniques and ultrafast imaging have enabled sensing through unconventional settings such as around corners, and through diffusive media. We exploit time of flight (ToF) measurements to enable a flexible interface for imaging through permuted set of fibers. The fibers are randomly distributed in the scene and are packed on the camera end, thus making a brush-like structure. The scene is illuminated by two off-axis optical pulses. Temporal signatures of fiber tips in the scene are used to localize each fiber. Finally, by combining the position and measured intensity of each fiber, the original input is reconstructed. Unlike conventional fiber bundles with packed set of fibers that are limited by a narrow field of view (FOV), lack of flexibility, and extended coaxial precalibration, the proposed optical brush is flexible and uses off-axis calibration method based on ToF. The enabled brush form can couple to other types of ToF imaging systems. This can impact probe-based applications such as, endoscopy, tomography, and industrial imaging and sensing.
Permutation centralizer algebras and multimatrix invariants
Mattioli, Paolo; Ramgoolam, Sanjaye
2016-03-01
We introduce a class of permutation centralizer algebras which underly the combinatorics of multimatrix gauge-invariant observables. One family of such noncommutative algebras is parametrized by two integers. Its Wedderburn-Artin decomposition explains the counting of restricted Schur operators, which were introduced in the physics literature to describe open strings attached to giant gravitons and were subsequently used to diagonalize the Gaussian inner product for gauge invariants of two-matrix models. The structure of the algebra, notably its dimension, its center and its maximally commuting subalgebra, is related to Littlewood-Richardson numbers for composing Young diagrams. It gives a precise characterization of the minimal set of charges needed to distinguish arbitrary matrix gauge invariants, which are related to enhanced symmetries in gauge theory. The algebra also gives a star product for matrix invariants. The center of the algebra allows efficient computation of a sector of multimatrix correlators. These generate the counting of a certain class of bicoloured ribbon graphs with arbitrary genus.
Permutation combinatorics of worldsheet moduli space
Freidel, Laurent; Garner, David; Ramgoolam, Sanjaye
2015-06-01
Light-cone string diagrams have been used to reproduce the orbifold Euler characteristic of moduli spaces of punctured Riemann surfaces at low genus and with few punctures. Nakamura studied the meromorphic differential introduced by Giddings and Wolpert to characterize light-cone diagrams and introduced a class of graphs related to this differential. These Nakamura graphs were used to parametrize the cells in a light-cone cell decomposition of moduli space. We develop links between Nakamura graphs and realizations of the worldsheet as branched covers. This leads to a development of the combinatorics of Nakamura graphs in terms of permutation tuples. For certain classes of cells, including those of the top dimension, there is a simple relation to Belyi maps, which allows us to use results from Hermitian and complex matrix models to give analytic formulas for the counting of cells at an arbitrarily high genus. For the most general cells, we develop a new equivalence relation on Hurwitz classes which organizes the cells and allows efficient enumeration of Nakamura graphs using the group theory software gap.
Peng, Wei; Ding, Fei; Xie, Yong
2016-01-01
In this contribution, the toxicological effects of C.I. Acid Red 2 and 1-(2-pyridylazo)-2-naphthol (PAN) have been elucidated by utilizing plasma albumin as a biological model. Fluorescence data indicated that the Trp-214 residue was quenched by both azo compounds, but the quenching degree of C.I. Acid Red 2 is less than PAN. According to the results of time-resolved fluorescence decay, it may be observed that the quenching of Trp-214 residue is controlled by static type; this corroborates the Stern-Volmer analyses and the conformational transition of protein was concurred. The experiments also found that azo colorants are situated within subdomain IIA, several amino acid residues, such as Ser-202, Ala-210, and Trp-214 were believed to be yielded direct interaction with the two chemicals, yet the operating distances between C.I. Acid Red 2 and relevant residues are greater than PAN. Interestingly, we may ascertain that the azo colorants with naphthalene ring possess stronger affinity with protein than those just having benzene ring in their molecular structure. This suggested that the existence of naphthalene ring substituent could hold relatively great risk for the human body due to large hydrophobicity (cLogP); therefore, the hydrophobicity of azo colorants can probably be a major element of its toxicological activities. PMID:26682933
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Christopher J Reed
Full Text Available Proteins from extremophiles have the ability to fold and remain stable in their extreme environment. Here, we investigate the presence of this effect in the cysteinyl-tRNA synthetase from Halobacterium salinarum ssp. NRC-1 (NRC-1, which was used as a model halophilic protein. The effects of salt on the structure and stability of NRC-1 and of E. coli CysRS were investigated through far-UV circular dichroism (CD spectroscopy, fluorescence spectroscopy, and thermal denaturation melts. The CD of NRC-1 CysRS was examined in different group I and group II chloride salts to examine the effects of the metal ions. Potassium was observed to have the strongest effect on NRC-1 CysRS structure, with the other group I salts having reduced strength. The group II salts had little effect on the protein. This suggests that the halophilic adaptations in this protein are mediated by potassium. CD and fluorescence spectra showed structural changes taking place in NRC-1 CysRS over the concentration range of 0-3 M KCl, while the structure of E. coli CysRS was relatively unaffected. Salt was also shown to increase the thermal stability of NRC-1 CysRS since the melt temperature of the CysRS from NRC-1 was increased in the presence of high salt, whereas the E. coli enzyme showed a decrease. By characterizing these interactions, this study not only explains the stability of halophilic proteins in extremes of salt, but also helps us to understand why and how group I salts stabilize proteins in general.
Tight bounds on the threshold for permuted k-colorability
Dani, Varsha; Olson, Anna
2011-01-01
If each edge (u,v) of a graph G=(V,E) is decorated with a permutation pi_{u,v} of k objects, we say that it has a permuted k-coloring if there is a coloring sigma from V to {1,...,k} such that sigma(v) is different from pi_{u,v}(sigma(u)) for all (u,v) in E. Based on arguments from statistical physics, we conjecture that the threshold d_k for permuted k-colorability in random graphs G(n,m=dn/2), where the permutations on the edges are uniformly random, is equal to the threshold for standard graph k-colorability. The additional symmetry provided by random permutations makes it easier to prove bounds on d_k. By applying the second moment method with these additional symmetries, and applying the first moment method to a random variable that depends on the number of available colors at each vertex, we bound the threshold within an additive constant. Specifically, we show that for any constant epsilon > 0, for sufficiently large k we have 2 k ln k - ln k - 2 - epsilon < d_k < 2 k ln k - ln k - 1 + epsilon. I...
Permutation Complexity and Coupling Measures in Hidden Markov Models
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Taichi Haruna
2013-09-01
Full Text Available Recently, the duality between values (words and orderings (permutations has been proposed by the authors as a basis to discuss the relationship between information theoretic measures for finite-alphabet stationary stochastic processes and their permutatio nanalogues. It has been used to give a simple proof of the equality between the entropy rate and the permutation entropy rate for any finite-alphabet stationary stochastic process and to show some results on the excess entropy and the transfer entropy for finite-alphabet stationary ergodic Markov processes. In this paper, we extend our previous results to hidden Markov models and show the equalities between various information theoretic complexity and coupling measures and their permutation analogues. In particular, we show the following two results within the realm of hidden Markov models with ergodic internal processes: the two permutation analogues of the transfer entropy, the symbolic transfer entropy and the transfer entropy on rank vectors, are both equivalent to the transfer entropy if they are considered as the rates, and the directed information theory can be captured by the permutation entropy approach.
Sensitive detection of p65 homodimers using red-shifted and fluorescent protein-based FRET couples.
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Joachim Goedhart
Full Text Available BACKGROUND: Fluorescence Resonance Energy Transfer (FRET between the green fluorescent protein (GFP variants CFP and YFP is widely used for the detection of protein-protein interactions. Nowadays, several monomeric red-shifted fluorescent proteins are available that potentially improve the efficiency of FRET. METHODOLOGY/PRINCIPAL FINDINGS: To allow side-by-side comparison of several fluorescent protein combinations for detection of FRET, yellow or orange fluorescent proteins were directly fused to red fluorescent proteins. FRET from yellow fluorescent proteins to red fluorescent proteins was detected by both FLIM and donor dequenching upon acceptor photobleaching, showing that mCherry and mStrawberry were more efficient acceptors than mRFP1. Circular permutated yellow fluorescent protein variants revealed that in the tandem constructs the orientation of the transition dipole moment influences the FRET efficiency. In addition, it was demonstrated that the orange fluorescent proteins mKO and mOrange are both suitable as donor for FRET studies. The most favorable orange-red FRET pair was mKO-mCherry, which was used to detect homodimerization of the NF-kappaB subunit p65 in single living cells, with a threefold higher lifetime contrast and a twofold higher FRET efficiency than for CFP-YFP. CONCLUSIONS/SIGNIFICANCE: The observed high FRET efficiency of red-shifted couples is in accordance with increased Förster radii of up to 64 A, being significantly higher than the Förster radius of the commonly used CFP-YFP pair. Thus, red-shifted FRET pairs are preferable for detecting protein-protein interactions by donor-based FRET methods in single living cells.
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Wei Chin-Chuan
2012-04-01
Full Text Available Abstract Background Superoxide generated by non-phagocytic NADPH oxidases (NOXs is of growing importance for physiology and pathobiology. The calcium binding domain (CaBD of NOX5 contains four EF-hands, each binding one calcium ion. To better understand the metal binding properties of the 1st and 2nd EF-hands, we characterized the N-terminal half of CaBD (NCaBD and its calcium-binding knockout mutants. Results The isothermal titration calorimetry measurement for NCaBD reveals that the calcium binding of two EF-hands are loosely associated with each other and can be treated as independent binding events. However, the Ca2+ binding studies on NCaBD(E31Q and NCaBD(E63Q showed their binding constants to be 6.5 × 105 and 5.0 × 102 M-1 with ΔHs of -14 and -4 kJ/mol, respectively, suggesting that intrinsic calcium binding for the 1st non-canonical EF-hand is largely enhanced by the binding of Ca2+ to the 2nd canonical EF-hand. The fluorescence quenching and CD spectra support a conformational change upon Ca2+ binding, which changes Trp residues toward a more non-polar and exposed environment and also increases its α-helix secondary structure content. All measurements exclude Mg2+-binding in NCaBD. Conclusions We demonstrated that the 1st non-canonical EF-hand of NOX5 has very weak Ca2+ binding affinity compared with the 2nd canonical EF-hand. Both EF-hands interact with each other in a cooperative manner to enhance their Ca2+ binding affinity. Our characterization reveals that the two EF-hands in the N-terminal NOX5 are Ca2+ specific. Graphical abstract
Non-Abelian braid statistics versus projective permutation statistics
International Nuclear Information System (INIS)
Recent papers by Finkelstein, Galiautdinov, and co-workers [J. Math. Phys. 42, 1489 (2001); 42, 3299 (2001)] discuss a suggestion by Wilczek that non-Abelian projective representations of the permutation group can be used as a new type of particle statistics, valid in any dimension. Wilczek's suggestion was based in part on an analysis by Nayak and Wilczek (NW) of the non-Abelian representation of the braid group in a quantum Hall system. We point out that projective permutation statistics is not possible in a local quantum field theory as it violates locality, and show that the NW braid group representation is not equivalent to a projective representation of the permutation group. The structure of the finite image of the braid group in a 2n/2-1-dimensional representation is obtained
Quantum mechanics and permutation invariants of finite groups
International Nuclear Information System (INIS)
We study quantum behavior from a constructive 'finite' point of view, since the introduction of continuum or other actual infinities into physics poses serious conceptual and technical difficulties without any need for these concepts in physics as an empirical science. Taking this approach, we can show that the quantum-mechanical problems can be formulated in the invariant subspaces of permutation representations of finite groups, while the quantum interferences occur as phenomena that are observable in these subspaces. The scalar products in the invariant subspaces (which are needed for formulating the Born rule – the main postulate of quantum mechanics that links mathematical description with experiment) are linear combinations of independent bilinear invariant forms of the permutation representation. A complete set of such forms for any permutation group can be easily calculated by a simple algorithm. Slightly more sophisticated algorithms are required for expressing quantum observables in terms of these forms.
Determination of Pavement Rehabilitation Activities through a Permutation Algorithm
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Sangyum Lee
2013-01-01
Full Text Available This paper presents a mathematical programming model for optimal pavement rehabilitation planning. The model maximized the rehabilitation area through a newly developed permutation algorithm, based on the procedures outlined in the harmony search (HS algorithm. Additionally, the proposed algorithm was based on an optimal solution method for the problem of multilocation rehabilitation activities on pavement structure, using empirical deterioration and rehabilitation effectiveness models, according to a limited maintenance budget. Thus, nonlinear pavement performance and rehabilitation activity decision models were used to maximize the objective functions of the rehabilitation area within a limited budget, through the permutation algorithm. Our results showed that the heuristic permutation algorithm provided a good optimum in terms of maximizing the rehabilitation area, compared with a method of the worst-first maintenance currently used in Seoul.
Permutation-based Homogeneous Block Content Authentication for Watermarking
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S.Maruthuperumal
2013-02-01
Full Text Available In modern days, digital watermarking has become an admired technique for hitting data in digital images to help guard against copyright infringement. The proposed Permutation-based Homogeneous Block Content authentication (PHBC methods develop a secure and excellence strong watermarking algorithm that combines the reward of permutation-based Homogeneous block (PHB with that of significant and insignificant bit values with X0R encryption function using Max coefficient of least coordinate value for embedding the watermark. In the projected system uses the relationship between the permutation blocks to embed many data into Homogeneous blocks without causing solemn distortion to the watermarked image. The experimental results show that the projected system is very efficient in achieving perceptual invisibility with an increase in the Peak Signal to Noise Ratio (PSNR. Moreover, the projected system is robust to a variety of signal processing operations, such as image Cropping, Rotation, Resizing, Adding noise, Filtering , Blurring and Motion blurring.
Permutations and the combinatorics of gauge invariants for general N
Ramgoolam, Sanjaye
2016-01-01
Group algebras of permutations have proved highly useful in solving a number of problems in large N gauge theories. I review the use of permutations in classifying gauge invariants in one-matrix and multi-matrix models and computing their correlators. These methods are also applicable to tensor models and have revealed a link between tensor models and the counting of branched covers. The key idea is to parametrize $U(N)$ gauge invariants using permutations, subject to equivalences. Correlators are related to group theoretic properties of these equivalence classes. Fourier transformation on symmetric groups by means of representation theory offers nice bases of functions on these equivalence classes. This has applications in AdS/CFT in identifying CFT duals of giant gravitons and their perturbations. It has also lead to general results on quiver gauge theory correlators, uncovering links to two dimensional topological field theory and the combinatorics of trace monoids.
Bipartite Graphs Related to Mutually Disjoint S-Permutation Matrices
Krasimir Yordzhev
2012-01-01
Some numerical characteristics of bipartite graphs in relation to the problem of finding all disjoint pairs of S-permutation matrices in the general $n^2 \\times n^2$ case are discussed in this paper. All bipartite graphs of the type $g=$, where $|R_g |=|C_g |=2$ or $|R_g |=|C_g |=3$ are provided. The cardinality of the sets of mutually disjoint S-permutation matrices in both the $4 \\times 4$ and $9 \\times 9$ cases are calculated.
Detecting regular dynamics from time series using permutations slopes
Eyebe Fouda, J. S. Armand; Koepf, Wolfram
2015-10-01
In this paper we present the entropy related to the largest slope of the permutation as an efficient approach for distinguishing between regular and non-regular dynamics, as well as the similarities between this method and the three-state test (3ST) algorithm. We theoretically establish that for suitably chosen delay times, permutations generated in the case of regular dynamics present the same largest slope if their order is greater than the period of the underlying orbit. This investigation helps making a clear decision (even in a noisy environment) in the detection of regular dynamics with large periods for which PE gives an arbitrary nonzero complexity measure.
Permutation entropy of fractional Brownian motion and fractional Gaussian noise
International Nuclear Information System (INIS)
We have worked out theoretical curves for the permutation entropy of the fractional Brownian motion and fractional Gaussian noise by using the Bandt and Shiha [C. Bandt, F. Shiha, J. Time Ser. Anal. 28 (2007) 646] theoretical predictions for their corresponding relative frequencies. Comparisons with numerical simulations show an excellent agreement. Furthermore, the entropy-gap in the transition between these processes, observed previously via numerical results, has been here theoretically validated. Also, we have analyzed the behaviour of the permutation entropy of the fractional Gaussian noise for different time delays
Yang-Baxter R-operators and parameter permutations
International Nuclear Information System (INIS)
We present an uniform construction of the solution to the Yang-Baxter equation with the symmetry algebra sl(2) and its deformations: the q-deformation and the elliptic deformation or Sklyanin algebra. The R-operator acting in the tensor product of two representations of the symmetry algebra with arbitrary spins l1 and l2 is built in terms of products of three basic operators S1, S2, S3 which are constructed explicitly. They have the simple meaning of representing elementary permutations of the symmetric group S4, the permutation group of the four parameters entering the RLL-relation
Free-field representation of permutation branes in Gepner models
International Nuclear Information System (INIS)
We consider a free-field realization of Gepner models based on the free-field realization of N = 2 superconformal minimal models. Using this realization, we analyze the A/B-type boundary conditions starting from the ansatz with the left-moving and right-moving free-field degrees of freedom glued at the boundary by an arbitrary constant matrix. We show that the only boundary conditions consistent with the singular vector structure of unitary minimal model representations are given by permutation matrices, thereby yielding an explicit free-field construction of the permutation branes of Recknagel
A Permutation Test for Identifying Significant Clusters in Spatial Dataset
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TANG Jianbo
2016-02-01
Full Text Available Spatial hierarchical clustering methods considering both spatial proximity and attribute similarity play an important role in exploratory spatial data analysis. Although existing methods are able to detect multi-scale homogeneous spatial contiguous clusters, the significance of these clusters cannot be evaluated in an objective way. In this study, a permutation test was developed to determine the significance of clusters discovered by spatial hierarchical clustering methods. Experiments on both simulated and meteorological datasets show that the proposed permutation test is effective for determining significant clustering structures from spatial datasets.
Profile classes and partial well-order for permutations
Murphy, Maximillian; Vatter, Vincent
2003-01-01
It is known that the set of permutations, under the pattern containment ordering, is not a partial well-order. Characterizing the partially well-ordered closed sets (equivalently: down sets or ideals) in this poset remains a wide-open problem. Given a 0/+-1 matrix M, we define a closed set of permutations called the profile class of M. These sets are generalizations of sets considered by Atkinson, Murphy, and Ruskuc. We show that the profile class of M is partially well-ordered if and only if...
On the topology of the permutation pattern poset
McNamara, Peter R. W.; Steingrimsson, Einar
2013-01-01
The set of all permutations, ordered by pattern containment, forms a poset. This paper presents the first explicit major results on the topology of intervals in this poset. We show that almost all (open) intervals in this poset have a disconnected subinterval and are thus not shellable. Nevertheless, there seem to be large classes of intervals that are shellable and thus have the homotopy type of a wedge of spheres. We prove this to be the case for all intervals of layered permutations that h...
On permutation symmetries of hopfield model neural network
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Boxi Wu
2001-01-01
Full Text Available Discrete Hopfield neural network (DHNN is studied by performing permutation operations on the synaptic weight matrix. The storable patterns set stored with Hebbian learning algorithm in a network without losing memories is studied, and a condition which makes sure all the patterns of the storable patterns set have a same basin size of attraction is proposed. Then, the permutation symmetries of the network are studied associating with the stored patterns set. A construction of the storable patterns set satisfying that condition is achieved by consideration of their invariance under a point group.
A reduction theorem for primitive binary permutation groups
Wiscons, Joshua
2015-01-01
A permutation group $(X,G)$ is said to be binary, or of relational complexity $2$, if for all $n$, the orbits of $G$ (acting diagonally) on $X^2$ determine the orbits of $G$ on $X^n$ in the following sense: for all $\\bar{x},\\bar{y} \\in X^n$, $\\bar{x}$ and $\\bar{y}$ are $G$-conjugate if and only if every pair of entries from $\\bar{x}$ is $G$-conjugate to the corresponding pair from $\\bar{y}$. Cherlin has conjectured that the only finite primitive binary permutation groups are $S_n$, groups of ...
Glycerol acyl-transfer kinetics of a circular permutated Candida antarctica Lipase B
Triacylglycerols containing a high abundance of unusual fatty acids, such as y-linolenic acid, or novel arylaliphatic acids, such as ferulic acid, are useful in pharmaceutical and cosmeceutical applications. Candida antarctica lipase B (CALB) is quite often used for non-aqueous synthesis, although ...
SELF-DUAL PERMUTATION CODES OVER FORMAL POWER SERIES RINGS AND FINITE PRINCIPAL IDEAL RINGS
Institute of Scientific and Technical Information of China (English)
张光辉; 刘宏伟
2013-01-01
In this paper, we study self-dual permutation codes over formal power series rings and finite principal ideal rings. We first give some results on the torsion codes associated with the linear codes over formal power series rings. These results allow for obtaining some conditions for non-existence of self-dual permutation codes over formal power series rings. Finally, we describe self-dual permutation codes over finite principal ideal rings by examining permutation codes over their component chain rings.
Permutation-like Matrix Groups with a Maximal Cycle of Prime Square Length
DENG, GUODONG; Fan, Yun
2013-01-01
A matrix group is said to be permutation-like if any matrix of the group is similar to a permutation matrix. G. Cigler proved that, if a permutation-like matrix group contains a normal cyclic subgroup which is generated by a maximal cycle and the matrix dimension is a prime, then the group is similar to a permutation matrix group. This paper extends the result to the case where the matrix dimension is a square of a prime.
On signed p-Kostka numbers and the indecomposable signed Young permutation modules
Giannelli, Eugenio; Lim, Kay Jin; Wildon, Mark
2015-01-01
We study the modular structure of signed Young permutation modules for symmetric groups. In particular, we give some new reductions for the signed $p$-Kostka numbers, namely the multiplicities of indecomposable signed Young modules as direct summands of signed Young permutation modules. In the second part of the article we completely classify the indecomposable signed Young permutation modules.
Mixing Times of Self-Organizing Lists and Biased Permutations
Bhakta, Prateek; Randall, Dana; Streib, Amanda Pascoe
2012-01-01
Sampling permutations from S_n is a fundamental problem from probability theory. The nearest neighbor transposition chain \\cal{M}}_{nn} is known to converge in time \\Theta(n^3 \\log n) in the uniform case and time \\Theta(n^2) in the constant bias case, in which we put adjacent elements in order with probability p \
APE: Authenticated Permutation-Based Encryption for Lightweight Cryptography
DEFF Research Database (Denmark)
Andreeva, Elena; Bilgin, Begül; Bogdanov, Andrey;
2015-01-01
of cryptographic schemes actually require the nonce assumption for their security. In this paper, we propose APE as the first permutation-based authenticated encryption scheme that is resistant against nonce misuse. We formally prove that APE is secure, based on the security of the underlying...
Boson permutation and parity operators: Lie algebra and applications
International Nuclear Information System (INIS)
We show that dichotomic permutation and parity operators for a two-dimensional boson system form an su(2) algebra with a unitary operator that relates, in quantum optics, to a balanced beamsplitter. The algebra greatly simplifies the input-output transformations of states through quantum nonlinear systems such as the Kerr interferometer or the kicked top
Updating Preconditioners for Permuted Non-Symmetric Linear Systems
Czech Academy of Sciences Publication Activity Database
Birken, P.; Duintjer Tebbens, Jurjen; Meister, A.; Tůma, Miroslav
2007-01-01
Roč. 7, č. 1 (2007), s. 1022101-1022102. ISSN 1617-7061 R&D Projects: GA AV ČR KJB100300703 Institutional research plan: CEZ:AV0Z10300504 Keywords : preconditioner updates * sequences of linear systems * nonsymmetric incomplete factorizations * physics-based permutation of linear systems Subject RIV: BA - General Mathematics
A Permutation Test for Correlated Errors in Adjacent Questionnaire Items
Hildreth, Laura A.; Genschel, Ulrike; Lorenz, Frederick O.; Lesser, Virginia M.
2013-01-01
Response patterns are of importance to survey researchers because of the insight they provide into the thought processes respondents use to answer survey questions. In this article we propose the use of structural equation modeling to examine response patterns and develop a permutation test to quantify the likelihood of observing a specific…
Permutation symmetry for neutrino and charged-lepton mass matrices
International Nuclear Information System (INIS)
Permutation symmetry S3 is applied to obtain two equal Majorana neutrino masses, while maintaining three different charged-lepton masses and suppressing neutrinoless double beta decay. The resulting radiative splitting of the two neutrinos is shown to be suitable for solar neutrino vacuum oscillations. (c) 2000 The American Physical Society
Note on permutation sum of color-ordered gluon amplitudes
International Nuclear Information System (INIS)
In this Letter we show that under BCFW-deformation the large-z behavior of permutation sum of color-ordered gluon amplitudes found by Boels and Isermann in (arxiv:1109.5888) can be simply understood from the well known Kleiss-Kuijf relation and Bern-Carrasco-Johansson relation.
Permutation Matrix Method for Dense Coding Using GHZ States
International Nuclear Information System (INIS)
We present a new method called the permutation matrix method to perform dense coding using Greenberger–Horne–Zeilinger (GHZ) states. We show that this method makes the study of dense coding systematically and regularly. It also has high potential to be realized physically. (general)
Local permutations of products of Bell states and entanglement distillation
International Nuclear Information System (INIS)
We present different algorithms for mixed-state multicopy entanglement distillation for pairs of qubits. Our algorithms perform significantly better than the best-known algorithms. Better algorithms can be derived that are tuned for specific initial states. These algorithms are based on a characterization of the group of all locally realizable permutations of the 4n possible tensor products of n Bell states
Permutation/randomization-based inference for environmental data.
Spicer, R Christopher; Gangloff, Harry J
2016-03-01
Quantitative inference from environmental contaminant data is almost exclusively from within the classic Neyman/Pearson (N/P) hypothesis-testing model, by which the mean serves as the fundamental quantitative measure, but which is constrained by random sampling and the assumption of normality in the data. Permutation/randomization-based inference originally forwarded by R. A. Fisher derives probability directly from the proportion of the occurrences of interest and is not dependent upon the distribution of data or random sampling. Foundationally, the underlying logic and the interpretation of the significance of the two models vary, but inference using either model can often be successfully applied. However, data examples from airborne environmental fungi (mold), asbestos in settled dust, and 1,2,3,4-tetrachlorobenzene (TeCB) in soil demonstrate potentially misleading inference using traditional N/P hypothesis testing based upon means/variance compared to permutation/randomization inference using differences in frequency of detection (Δf d). Bootstrapping and permutation testing, which are extensions of permutation/randomization, confirm calculated p values via Δf d and should be utilized to verify the appropriateness of a given data analysis by either model. PMID:26850713
Static non-abelian forces and the permutation group
International Nuclear Information System (INIS)
It is shown that the classical static interaction energy of two non-abelian point sources is ambiguous. The ambiguity is discrete and corresponds to the elements of the permutation group on n symbols, if the gauge group is U(n). (Auth.)
An Involution on Involutions and a Generalization of Layered Permutations
Bona, Miklos; Smith, Rebecca
2016-01-01
Taking transposes of Standard Young Tableaux defines a natural involution on the set $I(n)$ of involutions of length $n$ via the the Robinson-Schensted correspondence. In some cases, this involution can be defined without resorting to the Robinson-Schensted correspondence. As a byproduct, we get an interesting generalization of layered permutations.
Introduction to Permutation and Resampling-Based Hypothesis Tests
LaFleur, Bonnie J.; Greevy, Robert A.
2009-01-01
A resampling-based method of inference--permutation tests--is often used when distributional assumptions are questionable or unmet. Not only are these methods useful for obvious departures from parametric assumptions (e.g., normality) and small sample sizes, but they are also more robust than their parametric counterparts in the presences of…
Monoids of injective maps closed under conjugation by permutations
Mesyan, Zachary
2010-01-01
Let X be a countably infinite set, Inj(X) the monoid of all injective endomaps of X, and Sym(X) the group of all permutations of X. We classify all submonoids of Inj(X) that are closed under conjugation by elements of Sym(X).
A permutation test for the race model inequality
DEFF Research Database (Denmark)
Gondan, Matthias
2010-01-01
signals. Several statistical procedures have been used for testing the race model inequality. However, the commonly employed procedure does not control the Type I error. In this article a permutation test is described that keeps the Type I error at the desired level. Simulations show that the power of the...
A central limit theorem for a new statistic on permutations
Chatterjee, Sourav; Diaconis, Persi
2016-01-01
This paper does three things: It proves a central limit theorem for a novel permutation statistic, the number of descents plus the number of descents in the inverse. It provides a clear illustration of a new approach to proving central limit theorems more generally. It gives us an opportunity to acknowledge the work of our teacher and friend B. V. Rao.
A new permutational behaviour of spin -3/2 states
International Nuclear Information System (INIS)
A new permutational behaviour of spin -3/2 states under the symetric group S3 defined solely on the spin -3/2 space is demonstrated. The transposition elements of S3 are expressed succintly in terms of the squares of the spin -3/2 matrices. (Author)
Deformation of basaltic shield volcanoes under cointrusive stress permutations
Chaput, Marie; Famin, Vincent; Michon, Laurent
2014-01-01
We performed a microstructural study of Piton des Neiges (La Réunion Island) to understand how intrusions and stresses control each other in basaltic volcanoes. Our study reveals that three perpendicular intrusions trends coexisted during the 2 Myr history of the volcano: a N120-140°E rift zone, a perpendicular dike trend, and swarms of subhorizontal intrusions hereafter called "sill zones". Independently, the inversion of fault-slip data shows that incompatible paleostress fields recurrently occurred along with the intrusions: a dominant NNE-SSW extension, a perpendicular extension, and strike-slip or compressional regimes. The orientations of paleostresses are consistent with the orientations of the three perpendicular intrusion populations. We propose that stress accumulation in the edifice under the effect of repeated magma injections resulted in permutations of the principal axes of the stress tensor, causing a reorientation of subsequent intrusions. Stress permutations were cyclical. Each cycle started with dike injections in an extensional stress field, reducing the deviatoric stress and switching the axes of principal stresses, and finished with sill intrusions in a compressional stress field. Sill zones acted as detachment planes, restoring the extensional stress field and initiating a new cycle of permutations. Our model of stress permutations is in agreement with the pattern of eruptions and deformation observed at Piton de la Fournaise. In contrast with the Hawaiian model of spreading on a décollement, stress permutations in La Réunion's volcanoes imply that the basal deformation of the edifices, if any, is not sufficient to compensate the reduction of deviatoric stress caused by intrusions.
Non-parametric combination and related permutation tests for neuroimaging.
Winkler, Anderson M; Webster, Matthew A; Brooks, Jonathan C; Tracey, Irene; Smith, Stephen M; Nichols, Thomas E
2016-04-01
In this work, we show how permutation methods can be applied to combination analyses such as those that include multiple imaging modalities, multiple data acquisitions of the same modality, or simply multiple hypotheses on the same data. Using the well-known definition of union-intersection tests and closed testing procedures, we use synchronized permutations to correct for such multiplicity of tests, allowing flexibility to integrate imaging data with different spatial resolutions, surface and/or volume-based representations of the brain, including non-imaging data. For the problem of joint inference, we propose and evaluate a modification of the recently introduced non-parametric combination (NPC) methodology, such that instead of a two-phase algorithm and large data storage requirements, the inference can be performed in a single phase, with reasonable computational demands. The method compares favorably to classical multivariate tests (such as MANCOVA), even when the latter is assessed using permutations. We also evaluate, in the context of permutation tests, various combining methods that have been proposed in the past decades, and identify those that provide the best control over error rate and power across a range of situations. We show that one of these, the method of Tippett, provides a link between correction for the multiplicity of tests and their combination. Finally, we discuss how the correction can solve certain problems of multiple comparisons in one-way ANOVA designs, and how the combination is distinguished from conjunctions, even though both can be assessed using permutation tests. We also provide a common algorithm that accommodates combination and correction. Hum Brain Mapp 37:1486-1511, 2016. © 2016 Wiley Periodicals, Inc. PMID:26848101
Permutation-like Matrix Groups with a Maximal Cycle of Power of Odd Prime Length
Deng, Guodong; Yun FAN
2015-01-01
If every element of a matrix group is similar to a permutation matrix, then it is called a permutation-like matrix group. References [4] and [5] showed that, if a permutation-like matrix group contains a maximal cycle of length equal to a prime or a square of a prime and the maximal cycle generates a normal subgroup, then it is similar to a permutation matrix group. In this paper, we prove that if a permutation-like matrix group contains a maximal cycle of length equal to any power of any odd...
Permutation-like Matrix Groups with a Maximal Cycle of Length Power of Two
Deng, Guodong; Yun FAN
2016-01-01
If every element of a matrix group is similar to a permutation matrix, then it is called a permutation-like matrix group. References [4], [5] and [6] showed that, if a permutation-like matrix group contains a maximal cycle such that the maximal cycle generates a normal subgroup and the length of the maximal cycle equals to a prime, or a square of a prime, or a power of an odd prime, then the permutation-like matrix group is similar to a permutation matrix group. In this paper, we prove that i...
Finite state model and compatibility theory - New analysis tools for permutation networks
Huang, S.-T.; Tripathi, S. K.
1986-01-01
A simple model to describe the fundamental operation theory of shuffle-exchange-type permutation networks, the finite permutation machine (FPM), is described, and theorems which transform the control matrix result to a continuous compatible vector result are developed. It is found that only 2n-1 shuffle exchange passes are necessary, and that 3n-3 passes are sufficient, to realize all permutations, reducing the sufficient number of passes by two from previous results. The flexibility of the approach is demonstrated by the description of a stack permutation machine (SPM) which can realize all permutations, and by showing that the FPM corresponding to the Benes (1965) network belongs to the SPM. The FPM corresponding to the network with two cascaded reverse-exchange networks is found to realize all permutations, and a simple mechanism to verify several equivalence relationships of various permutation networks is discussed.
A chronicle of permutation statistical methods 1920–2000, and beyond
Berry, Kenneth J; Mielke Jr , Paul W
2014-01-01
The focus of this book is on the birth and historical development of permutation statistical methods from the early 1920s to the near present. Beginning with the seminal contributions of R.A. Fisher, E.J.G. Pitman, and others in the 1920s and 1930s, permutation statistical methods were initially introduced to validate the assumptions of classical statistical methods. Permutation methods have advantages over classical methods in that they are optimal for small data sets and non-random samples, are data-dependent, and are free of distributional assumptions. Permutation probability values may be exact, or estimated via moment- or resampling-approximation procedures. Because permutation methods are inherently computationally-intensive, the evolution of computers and computing technology that made modern permutation methods possible accompanies the historical narrative. Permutation analogs of many well-known statistical tests are presented in a historical context, including multiple correlation and regression, ana...
Circularity and Lambda Abstraction
DEFF Research Database (Denmark)
Danvy, Olivier; Thiemann, Peter; Zerny, Ian
2013-01-01
In this tribute to Doaitse Swierstra, we present the rst transformation between lazy circular programs a la Bird and strict cir- cular programs a la Pettorossi. Circular programs a la Bird rely on lazy recursive binding: they involve circular unknowns and make sense equa- tionally. Circular...... unknowns from what is done to them, which we lambda-abstract with functions. The circular unknowns then become dead variables, which we eliminate. The result is a strict circu- lar program a la Pettorossi. This transformation is reversible: given a strict circular program a la Pettorossi, we introduce...
Permutation based speech scrambling for next generation mobile communication
Directory of Open Access Journals (Sweden)
Dhanya G
2016-04-01
Full Text Available Scrambling is a really significant method that provides protection in communication systems by using random permutation and pseudorandom binary scrambling method. To enhance the security in communication, OFDM scrambling can provide better protection than an FFT scrambler under same permutation operation. To evaluate the quality of the proposed system, perceptual evaluation of speech quality is used. The objective test SNR and BER are used to estimate the noise performance of the system. STI and CIS were applied to know the performance of the system. From the simulations, it is clear that, the proposed system shows better performance than conventional scrambling technique and it is more robust in the 4th generation of mobile communication.
Integrable quantum mechanics, the permutation group and the second law
International Nuclear Information System (INIS)
Given an integrable (solvable) quantum system with many equivalent degrees of freedom it is inevitable that consideration of the permutation group will arise. For example the least degenerate stationary states of the system must fall into irreducible representations of the permutation group. The ground state, as well as a class of low-lying excited states, must fall into a particular irreducible representation. It will be demonstrated that a superposition of states within this representation leads to marginal probability distributions (partial traces), which are time-independent. These marginal probability distributions are constant in time, but not in space. They provide a resource that can be exploited in reversible quasi-static (equilibrium) changes of state, i.e. they are a quantum contribution to the entropy. They are necessarily an essential part of any quantum statement of the second law
A WATERMARKING ALGORITHM BASED ON PERMUTATION AND 2-D BARCODE
Institute of Scientific and Technical Information of China (English)
Ji Zhen; Zhang Jihong; Xie Weixin
2001-01-01
This letter presents a method for digital image watermarking for copyright protection. This technique produces a watermarked image that closely retains the quality of the original host image while concurrently surviving various image processing operations such as lowpass/highpass filtering, lossy JPEG compression, and cropping. This image watermarking algorithm takes full advantage of permutation and 2-D barcode (PDF417). The actual watermark embedding in spatial domain is followed using permutated image for improving the resistance to image cropping. Much higher watermark robustness is obtainable via a simple forward error correction technique, which is the main feature of PDF417 codes. Additional features of this technique include the easy determination of the existence of the watermark and that the watermark verification procedure does not need the original host image. The experimental results demonstrate its effectiveness.
Secure physical layer using dynamic permutations in cognitive OFDMA systems
DEFF Research Database (Denmark)
Meucci, F.; Wardana, Satya Ardhy; Prasad, Neeli R.
2009-01-01
This paper proposes a novel lightweight mechanism for a secure Physical (PHY) layer in Cognitive Radio Network (CRN) using Orthogonal Frequency Division Multiplexing (OFDM). User's data symbols are mapped over the physical subcarriers with a permutation formula. The PHY layer is secured with a...... confidentiality. The method is shown to be effective also for existing non-cognitive systems. The proposed mechanism is effective against eavesdropping even if the eavesdropper adopts a long-time patterns analysis, thus protecting cryptography techniques of higher layers. The correlation properties of the...... permutations are analyzed for several DSA patterns. Simulations are performed according to the parameters of the IEEE 802.16e system model. The securing mechanism proposed provides intrinsic PHY layer security and it can be easily implemented in the current IEEE 802.16 standard applying almost negligible...
Power map permutations and symmetric differences in finite groups
Hablicsek, Márton
2011-01-01
Let $G$ be a finite group. For all $a \\in \\Z$, such that $(a,|G|)=1$, the function $\\rho_a: G \\to G$ sending $g$ to $g^a$ defines a permutation of the elements of $G$. Motivated by a recent generalization of Zolotarev's proof of classic quadratic reciprocity, due to Duke and Hopkins, we study the signature of the permutation $\\rho_a$. By introducing the group of conjugacy equivariant maps and the symmetric difference method on groups, we exhibit an integer $d_{G}$ such that $\\text{sgn}(\\rho_a)=(\\frac{d_G}{a})$ for all $G$ in a large class of groups, containing all finite nilpotent and odd order groups.
Extending partial representations of function graphs and permutation graphs
Klavík, Pavel; Krawczyk, Tomasz; Walczak, Bartosz
2012-01-01
Function graphs are graphs representable by intersections of continuous real-valued functions on the interval [0,1] and are known to be exactly the complements of comparability graphs. As such they are recognizable in polynomial time. Function graphs generalize permutation graphs, which arise when all functions considered are linear. We focus on the problem of extending partial representations, which generalizes the recognition problem. We observe that for permutation graphs an easy extension of Golumbic's comparability graph recognition algorithm can be exploited. This approach fails for function graphs. Nevertheless, we present a polynomial-time algorithm for extending a partial representation of a graph by functions defined on the entire interval [0,1] provided for some of the vertices. On the other hand, we show that if a partial representation consists of functions defined on subintervals of [0,1], then the problem of extending this representation to functions on the entire interval [0,1] becomes NP-comp...
Entangling power of permutation-invariant quantum states
International Nuclear Information System (INIS)
We investigate the von Neumann entanglement entropy as function of the size of a subsystem for permutation invariant ground states in models with finite number of states per site, e.g., in quantum spin models. We demonstrate that the entanglement entropy of n sites in a system of length L generically grows as σ log2[2πen(L-n)/L]+C, where σ is the on-site spin and C is a function depending only on magnetization
Testing of Error-Correcting Sparse Permutation Channel Codes
Shcheglov, Kirill, V.; Orlov, Sergei S.
2008-01-01
A computer program performs Monte Carlo direct numerical simulations for testing sparse permutation channel codes, which offer strong error-correction capabilities at high code rates and are considered especially suitable for storage of digital data in holographic and volume memories. A word in a code of this type is characterized by, among other things, a sparseness parameter (M) and a fixed number (K) of 1 or "on" bits in a channel block length of N.
Information sets as permutation cycles for quadratic residue codes
Directory of Open Access Journals (Sweden)
Richard A. Jenson
1982-01-01
Full Text Available The two cases p=7 and p=23 are the only known cases where the automorphism group of the [p+1, (p+1/2] extended binary quadratic residue code, O(p, properly contains PSL(2,p. These codes have some of their information sets represented as permutation cycles from Aut(Q(p. Analysis proves that all information sets of Q(7 are so represented but those of Q(23 are not.
Application of Permutation Group Theory in Reversible Logic Synthesis
Zakablukov, Dmitry V.
2015-01-01
The paper discusses various applications of permutation group theory in the synthesis of reversible logic circuits consisting of Toffoli gates with negative control lines. An asymptotically optimal synthesis algorithm for circuits consisting of gates from the NCT library is described. An algorithm for gate complexity reduction, based on equivalent replacements of gates compositions, is introduced. A new approach for combining a group-theory-based synthesis algorithm with a Reed-Muller-spectra...
Bootstrapped Permutation Test for Multiresponse Inference on Brain Behavior Associations.
Ng, Bernard; Poline, Jean Baptiste; Thirion, Bertrand; Greicius, Michael
2015-01-01
Despite that diagnosis of neurological disorders commonly involves a collection of behavioral assessments, most neuroimaging studies investigating the associations between brain and behavior largely analyze each behavioral measure in isolation. To jointly model multiple behavioral scores, sparse multiresponse regression (SMR) is often used. However, directly applying SMR without statistically controlling for false positives could result in many spurious findings. For models, such as SMR, where the distribution of the model parameters is unknown, permutation test and stability selection are typically used to control for false positives. In this paper, we present another technique for inferring statistically significant features from models with unknown parameter distribution. We refer to this technique as bootstrapped permutation test (BPT), which uses Studentized statistics to exploit the intuition that the variability in parameter estimates associated with relevant features would likely be higher with responses permuted. On synthetic data, we show that BPT provides higher sensitivity in identifying relevant features from the SMR model than permutation test and stability selection, while retaining strong control on the false positive rate. We further apply BPT to study the associations between brain connectivity estimated from pseudo-rest fMRI data of 1139 fourteen year olds and behavioral measures related to ADHD. Significant connections are found between brain networks known to be implicated in the behavioral tasks involved. Moreover, we validate the identified connections by fitting a regression model on pseudo-rest data with only those connections and applying this model on resting state fMRI data of 337 left out subjects to predict their behavioral scores. The predicted scores significantly correlate with the actual scores, hence verifying the behavioral relevance of the found connections. PMID:26221670
Institute of Scientific and Technical Information of China (English)
SHEN Guo-quan; XIAO Yuan-chun
2003-01-01
@@ "Mo" literally means "rubbing between two things"and "eliminating". Circular-rubbing is one of the earliest manipulations used in clinical practice. Circular-rubbing differs from pressing actually. Pressing is a static manipulation and acts to inhibit motion; circular-rubbing is a movable manipulation and serves to eliminate stationary. Circular-rubbing can be performed by either the palm or the finger.
Properties of permuted-block randomization in clinical trials.
Matts, J P; Lachin, J M
1988-12-01
This article describes some of the important statistical properties of the commonly used permuted-block design, also known simply as blocked-randomization. Under a permutation model for statistical tests, proper analyses should employ tests that incorporate the blocking used in the randomization. These include the block-stratified Mantel-Haenszel chi-square test for binary data, the blocked analysis of variance F test, and the blocked nonparametric linear rank test. It is common, however, to ignore the blocking in the analysis. For these tests, it is shown that the size of a test obtained from an analysis incorporating the blocking (say T), versus an analysis ignoring the blocking (say TI), is related to the intrablock correlation coefficient (R) as TI = T(1-R). For blocks of common length 2m, the range of R is from -1/(2m-1) to 1. Thus, if there is a positive intrablock correlation, which is more likely than not for m greater than 1, an analysis ignoring blocking will be unduly conservative. Permutation tests are also presented for the case of stratified analyses within one or more subgroups of patients defined post hoc on the basis of a covariate. This provides a basis for the analysis when responses from some patients are assumed to be missing-at-random. An alternative strategy that requires no assumptions is to perform the analysis using only the subset of complete blocks in which no observations are missing. The Blackwell-Hodges model is used to assess the potential for selection bias induced by investigator attempts to guess which treatment is more likely to be assigned to each incoming patient. In an unmasked trial, the permuted-block design provides substantial potential for selection bias in the comparison of treatments due to the predictability of the assignments that is induced by the requirement of balance within blocks. Further, this bias is not eliminated by the use of random block sizes. We also modify the Blackwell-Hodges model to allow for
Damanik, Asan; Muslim,; Anggraita, Pramudita
2007-01-01
We evaluate the predictive power of the neutrino mass matrices arising from seesaw mechanism subjected to texture zero and satisfying a cyclic permutation invariant. We found that only two from eight possible patterns of the neutrino mass matrices are invariant under a cyclic permutation. The two resulted neutrino mass matrices which are invariant under a cyclic permutation can be used qualitatively to explain the neutrino mixing phenomena for solar neutrino and to derive the mixing angle that agress with the experimental data.
Generalised permutation branes on a product of cosets Gk1/HxGk2/H
International Nuclear Information System (INIS)
We study the modifications of the generalized permutation branes defined in hep-th/0509153, which are required to give rise to the non-factorizable branes on a product of cosets Gk1/HxGk2/H. We find that for k1k2 there exists big variety of branes, which reduce to the usual permutation branes, when k1=k2 and the permutation symmetry is restored
Permutation and parametric bootstrap tests for gene—gene and gene—environment interactions
Bůžková, Petra; Lumley, Thomas; Rice, Kenneth
2011-01-01
Permutation tests are widely used in genomic research as a straightforward way to obtain reliable statistical inference without making strong distributional assumptions. However, in this paper we show that in genetic association studies it is not typically possible to construct exact permutation tests of gene-gene or gene-environment interaction hypotheses. We describe an alternative to the permutation approach in testing for interaction, a parametric bootstrap approach. Using simulations, we...
Wagner, Brandie D.; Zerbe, Gary O; Mexal, Sharon; Leonard, Sherry S.
2008-01-01
The aim of this paper is to generalize permutation methods for multiple testing adjustment of significant partial regression coefficients in a linear regression model used for microarray data. Using a permutation method outlined by Anderson and Legendre [1999] and the permutation P-value adjustment from Simon et al. [2004], the significance of disease related gene expression will be determined and adjusted after accounting for the effects of covariates, which are not restricted to be categori...
Directory of Open Access Journals (Sweden)
Hossein Karimi
2011-04-01
Full Text Available The permutation method of multiple attribute decision making has two significant deficiencies: high computational time and wrong priority output in some problem instances. In this paper, a novel permutation method called adjusted permutation method (APM is proposed to compensate deficiencies of conventional permutation method. We propose Tabu search (TS and particle swarm optimization (PSO to find suitable solutions at a reasonable computational time for large problem instances. The proposed method is examined using some numerical examples to evaluate the performance of the proposed method. The preliminary results show that both approaches provide competent solutions in relatively reasonable amounts of time while TS performs better to solve APM.
Dyck Paths, Standard Young Tableaux, and Pattern Avoiding Permutations
Gudmundsson, Hilmar
2009-01-01
We present a generating function and a closed counting formula in two variables that enumerate a family of classes of permutations that avoid or contain an increasing pattern of length three and have a prescribed number of occurrences of another pattern of length three. This gives a refinement of some previously studied statistics, most notably one by Noonan. The formula is also shown to enumerate a family of classes of Dyck paths and Standard Young Tableaux, and a bijection is given between the corresponding classes of these two families of objects. Finally, the results obtained are used to solve an optimization problem for a certain card game.
Multiparticle SUSY quantum mechanics and representations of the permutation group
International Nuclear Information System (INIS)
The method of multidimensional SUSY quantum mechanics is applied to the investigation of supersymmetrical N -particle systems on a line for the case of separable centre-of-mass motion. New decomposition of the super-Hamiltonian into block-diagonal form with elementary matrix components is constructed. Matrices of coefficients of these minimal blocks are shown to coincide with matrices of irreducible representations of the permutation group SN , which correspond to the Young tableaux (N-M ,1M ). The connections with known generalizations of N-particle Calogero and Sutherland models are established. (author)
Entanglement and symmetry in permutation-symmetric states
International Nuclear Information System (INIS)
We investigate the relationship between multipartite entanglement and symmetry, focusing on permutation symmetric states. We give a highly intuitive geometric interpretation to entanglement via the Majorana representation, where these states correspond to points on a unit sphere. We use this to show how various entanglement properties are determined by the symmetry properties of the states. The geometric measure of entanglement is thus phrased entirely as a geometric optimization and a condition for the equivalence of entanglement measures written in terms of point symmetries. Finally, we see that different symmetries of the states correspond to different types of entanglement with respect to interconvertibility under stochastic local operations and classical communication.
Some open questions in the theory of generalized permutable subgroups
Institute of Scientific and Technical Information of China (English)
无
2009-01-01
A subgroup H of a group G is said to be weakly s-supplemented in G if H has a supplement T in G such that H ∩ T HsG, where HsG is the largest s-permutable subgroup of G contained in H. This paper constructs an example to show that the open questions 6.3 and 6.4 in J Algebra, 315: 192–209 (2007) have negative solutions, and shows that in many cases Question 6.4 is positive. A series of known results are unified and generalized.
Permutation Groups with Bounded Movement having Maximum Orbits
Indian Academy of Sciences (India)
Mehdi Alaeiyan; Behnam Razzaghmaneshi
2012-05-01
Let be a permutation group on a set with no fixed points in and let be a positive integer. If no element of moves any subset of by more than points (that is, $|^g\\backslash|≤ m$ for every $\\subseteq$ and $g\\in G$), and also if each -orbit has size greater than 2, then the number of -orbits in is at most $\\frac{1}{2}(3m-1)$. Moreover, the equality holds if and only if is an elementary abelian 3-group.
PUBLICATION OF ADMINISTRATIVE CIRCULAR
HR Department
2008-01-01
ADMINISTRATIVE CIRCULAR NO. 23 (REV. 2) – SPECIAL WORKING HOURS Administrative Circular No. 23 (Rev. 2) entitled "Special working hours", approved following discussion in the Standing Concertation Committee meeting of 9 December 2008, will be available on the intranet site of the Human Resources Department as from 19 December 2008: http://cern.ch/hr-docs/admincirc/admincirc.asp It cancels and replaces Administrative Circular No. 23 (Rev. 1) entitled "Stand-by duty" of April 1988. A "Frequently Asked Questions" information document on special working hours will also be available on this site. Paper copies of this circular will shortly be available in departmental secretariats. Human Resources Department Tel. 78003
Publication of administrative circular
HR Department
2009-01-01
ADMINISTRATIVE CIRCULAR NO. 23 (REV. 2) – SPECIAL WORKING HOURS Administrative Circular No. 23 (Rev. 2) entitled "Special working hours", approved following discussion in the Standing Concertation Committee on 9 December 2008, will be available on the intranet site of the Human Resources Department as from 19 December 2008: http://cern.ch/hr-docs/admincirc/admincirc.asp It cancels and replaces Administrative Circular No. 23 (Rev. 1) entitled "Stand-by duty" of April 1988. A "Frequently Asked Questions" information document on special working hours will also be available on this site. Paper copies of this circular will shortly be available in Departmental Secretariats. Human Resources Department Tel. 78003
Raybould, T. A.; Fedotov, V. A.; Papasimakis, N.; Kuprov, I.; Youngs, I. J.; Chen, W. T.; Tsai, D. P.; Zheludev, N. I.
2016-07-01
We demonstrate that the induced toroidal dipole, represented by currents flowing on the surface of a torus, makes a distinct and indispensable contribution to circular dichroism. We show that toroidal circular dichroism supplements the well-known mechanism involving electric dipole and magnetic dipole transitions. We illustrate this with rigorous analysis of the experimentally measured polarization-sensitive transmission spectra of an artificial metamaterial, constructed from elements of toroidal symmetry. We argue that toroidal circular dichroism will be found in large biomolecules with elements of toroidal symmetry and should be taken into account in the interpretation of circular dichroism spectra of organics.
International Nuclear Information System (INIS)
I consider the Zλ,λ prime free-bosonic permutation orbifolds as interacting physical string systems at c=26λ. As a first step, I introduce twisted tree diagrams which confirm at the interacting level that the physical spectrum of each twisted sector is equivalent to that of an ordinary c=26 closed string. The untwisted sectors are surprisingly more difficult to understand, and there are subtleties in the sewing of the loops, but I am able to propose provisional forms for the full modular-invariant cosmological constants and one-loop diagrams with insertions
Permutation auto-mutual information of electroencephalogram in anesthesia
Liang, Zhenhu; Wang, Yinghua; Ouyang, Gaoxiang; Voss, Logan J.; Sleigh, Jamie W.; Li, Xiaoli
2013-04-01
Objective. The dynamic change of brain activity in anesthesia is an interesting topic for clinical doctors and drug designers. To explore the dynamical features of brain activity in anesthesia, a permutation auto-mutual information (PAMI) method is proposed to measure the information coupling of electroencephalogram (EEG) time series obtained in anesthesia. Approach. The PAMI is developed and applied on EEG data collected from 19 patients under sevoflurane anesthesia. The results are compared with the traditional auto-mutual information (AMI), SynchFastSlow (SFS, derived from the BIS index), permutation entropy (PE), composite PE (CPE), response entropy (RE) and state entropy (SE). Performance of all indices is assessed by pharmacokinetic/pharmacodynamic (PK/PD) modeling and prediction probability. Main results. The PK/PD modeling and prediction probability analysis show that the PAMI index correlates closely with the anesthetic effect. The coefficient of determination R2 between PAMI values and the sevoflurane effect site concentrations, and the prediction probability Pk are higher in comparison with other indices. The information coupling in EEG series can be applied to indicate the effect of the anesthetic drug sevoflurane on the brain activity as well as other indices. The PAMI of the EEG signals is suggested as a new index to track drug concentration change. Significance. The PAMI is a useful index for analyzing the EEG dynamics during general anesthesia.
Quantum graph vertices with permutation-symmetric scattering probabilities
International Nuclear Information System (INIS)
Boundary conditions in quantum graph vertices are generally given in terms of a unitary matrix U. Observing that if U has at most two eigenvalues, then the scattering matrix S(k) of the vertex is a linear combination of the identity matrix and a fixed Hermitian unitary matrix, we construct vertex couplings with this property: For all momenta k, the transmission probability from the j-th edge to l-th edge is independent of (j,l), and all the reflection probabilities are equal. We classify these couplings according to their scattering properties, which leads to the concept of generalized δ- and δ'-couplings. -- Highlights: → There exist various types of couplings in quantum graph vertices. → The 'scale invariant' and the 'permutation-symmetric' coupling family are prominent. → We find a common generalization of scale invariant and permutation-symmetric family. → It allows us to find equally-transmitting vertex couplings of given characteristics. → Some of them can be identified as generalized delta and delta-prime couplings.
IMAGE ENCRYPTION USING PERMUTATION AND ROTATIONAL XOR TECHNIQUE
Directory of Open Access Journals (Sweden)
Avi Dixit
2012-07-01
Full Text Available Encryption is used to securely transmit data in open networks. Each type of data has its own features, therefore different techniques should be used to protect confidential image data from unauthorized access. Most of the available encryption algorithms are mainly used for textual data and may not be suitable for multimedia data such as images. In this paper, we introduce an algorithm. The binary code of the pixel values of a colour image is extracted and permuted according to the entered 8 bit key which is followed by the permutation of every 8 consecutive pixels [4]. The image is further divided into blocks which are shifted accordingly. The above mentioned technique has a few drawbacks, like the small key size. To further enforce the encryption another method is appended to it which requires a 43 digit key. The encryption takes a total of 10 rounds in which two keys are use, both of which are derived from the 43 digit entered key. The results showed that the correlation between image elements was significantly decreased by using the proposed technique.
Commodity predictability analysis with a permutation information theory approach
Zunino, Luciano; Tabak, Benjamin M.; Serinaldi, Francesco; Zanin, Massimiliano; Pérez, Darío G.; Rosso, Osvaldo A.
2011-03-01
It is widely known that commodity markets are not totally efficient. Long-range dependence is present, and thus the celebrated Brownian motion of prices can be considered only as a first approximation. In this work we analyzed the predictability in commodity markets by using a novel approach derived from Information Theory. The complexity-entropy causality plane has been recently shown to be a useful statistical tool to distinguish the stage of stock market development because differences between emergent and developed stock markets can be easily discriminated and visualized with this representation space [L. Zunino, M. Zanin, B.M. Tabak, D.G. Pérez, O.A. Rosso, Complexity-entropy causality plane: a useful approach to quantify the stock market inefficiency, Physica A 389 (2010) 1891-1901]. By estimating the permutation entropy and permutation statistical complexity of twenty basic commodity future markets over a period of around 20 years (1991.01.02-2009.09.01), we can define an associated ranking of efficiency. This ranking is quantifying the presence of patterns and hidden structures in these prime markets. Moreover, the temporal evolution of the commodities in the complexity-entropy causality plane allows us to identify periods of time where the underlying dynamics is more or less predictable.
DEFF Research Database (Denmark)
Hansen, Lennard Højbjerg
2014-01-01
It has been an accepted precept in film theory that specific stylistic features do not express specific content. Nevertheless, it is possible to find many examples in the history of film in which stylistic features do express specific content: for instance, the circular camera movement is used...... circular camera movement. Keywords: embodied perception, embodied style, explicit narration, interpretation, style pattern, television style...
A Studentized Permutation Test for the Comparison of Spatial Point Patterns
DEFF Research Database (Denmark)
Hahn, Ute
empirical K-functions are compared by a permutation test using a studentized test statistic. The proposed test performs convincingly in terms of empirical level and power in a simulation study, even for point patterns where the K-function estimates on neighboring subsamples are not strictly exchangeable. It...... studentized permutation test indicates statistical significance, although the patterns cannot be clearly distinguished by eye....
Using R to Simulate Permutation Distributions for Some Elementary Experimental Designs
Eudey, T. Lynn; Kerr, Joshua D.; Trumbo, Bruce E.
2010-01-01
Null distributions of permutation tests for two-sample, paired, and block designs are simulated using the R statistical programming language. For each design and type of data, permutation tests are compared with standard normal-theory and nonparametric tests. These examples (often using real data) provide for classroom discussion use of metrics…
Permutation-parity exchange at a beam splitter: Application to Heisenberg-limited interferometry
International Nuclear Information System (INIS)
Quantum-optical permutation and parity observables are unitarily exchanged by a 50:50 beam splitter. Bosonic coalescence effects are reexamined from this point of view. We show that photon-number resolving counters behind a beam splitter define a permutation detector for the input optical field. With suitable phase encoding, the detector also enables Heisenberg-limited interferometry
Linting, Marielle; van Os, Bart Jan; Meulman, Jacqueline J.
2011-01-01
In this paper, the statistical significance of the contribution of variables to the principal components in principal components analysis (PCA) is assessed nonparametrically by the use of permutation tests. We compare a new strategy to a strategy used in previous research consisting of permuting the columns (variables) of a data matrix…
Sukoriyanto; Nusantara, Toto; Subanji; Chandra, Tjang Daniel
2016-01-01
This article was written based on the results of a study evaluating students' errors in problem solving of permutation and combination in terms of problem solving steps according to Polya. Twenty-five students were asked to do four problems related to permutation and combination. The research results showed that the students still did a mistake in…
On constructing complete permutation polynomials over finite fields of even characteristic
Wu, Baofeng; Lin, Dongdai
2013-01-01
In this paper, a construction of complete permutation polynomials over finite fields of even characteristic proposed by Tu et al. recently is generalized in a recursive manner. Besides, several classes of complete permutation polynomials are derived by computing compositional inverses of known ones.
A note on inverses of cyclotomic mapping permutation polynomials over finite fields
WANG Qiang
2016-01-01
In this note, we give a shorter proof of a result of Zheng, Yu, and Pei on the explicit formula of inverses of generalized cyclotomic permutation polynomials over finite fields. Moreover, we characterize all these cyclotomic permutation polynomials that are involutions.
Minimal Degrees of Faithful Quasi-Permutation Representations for Direct Products of -Groups
Indian Academy of Sciences (India)
Ghodrat Ghaffarzadeh; Mohammad Hassan Abbaspour
2012-08-01
In [2], the algorithms of $c(G), q(G)$ and $p(G)$, the minimal degrees of faithful quasi-permutation and permutation representations of a finite group are given. The main purpose of this paper is to consider the relationship between these minimal degrees of non-trivial -groups and with the group × .
Exact Permutation Algorithm for Paired Observations: The Challenge of R. A. Fisher
Directory of Open Access Journals (Sweden)
J. I. Odiase
2007-01-01
Full Text Available The major handicap of permutation test is the logical and computational requirement necessary to develop and implement the exact permutation scheme. This study provides an algorithm that systematically enumerates all the distinct permutations of the paired observations in an experiment without the possibility of repeating any of the permutations. The permutation algorithm presented completely breaks down the permutation problem for ease of implementation and analysis. The algorithm was illustratively implemented in Intel Visual Fortran to recreate Fishers manual compilation of 32,768 permutations of Charles Darwins data on heights of cross-fertilized and self-fertilized plants. The algorithm provides exact p-values for any experiment involving paired observations and exposes the danger in using asymptotic or parametric distributions such as the t-test to analyze small data sets when the exact functional form of the distribution is not explicitly known. This becomes more obvious especially when the experiment leads to a p-value close to the threshold level of significance. The exact distribution and the graphical presentation provided in this study give credence to the use of the permutation test.
An upper bound on the number of high-dimensional permutations
Linial, Nathan
2011-01-01
What is the higher-dimensional analog of a permutation? If we think of a permutation as given by a permutation matrix, then the following definition suggests itself: A d-dimensional permutation of order n is an [n]^(d+1) array of zeros and ones in which every "line" contains a unique 1 entry. A line here is a set of entries of the form {(x_1,...,x_{i-1},y,x_{i+1},...,x_{d+1})}, for y between 1 and n, some index i between 1 and d+1 and some choice of x_j in [n] for all j except i. It is easy to observe that a one-dimensional permutation is simply a permutation matrix and that a two-dimensional permutation is synonymous with an order-n Latin square. We seek an estimate for the number of d-dimensional permutations. Our main result is the following upper bound on their number: ((1+o(1))(n/e^d))^(n^d). We tend to believe that this is actually the correct number, but the problem of proving the complementary lower bound remains open. Our main tool is an adaptation of Bregman's proof of the Minc conjecture on permane...
Circularly symmetric light scattering from nanoplasmonic spirals.
Trevino, Jacob; Cao, Hui; Dal Negro, Luca
2011-05-11
In this paper, we combine experimental dark-field imaging, scattering, and fluorescence spectroscopy with rigorous electrodynamics calculations in order to investigate light scattering from planar arrays of Au nanoparticles arranged in aperiodic spirals with diffuse, circularly symmetric Fourier space. In particular, by studying the three main types of Vogel's spirals fabricated by electron-beam lithography on quartz substrates, we demonstrate polarization-insensitive planar light diffraction in the visible spectral range. Moreover, by combining dark-field imaging with analytical multiparticle calculations in the framework of the generalized Mie theory, we show that plasmonic spirals support distinctive structural resonances with circular symmetry carrying orbital angular momentum. The engineering of light scattering phenomena in deterministic structures with circular Fourier space provides a novel strategy for the realization of optical devices that fully leverage on enhanced, polarization-insensitive light-matter coupling over planar surfaces, such as thin-film plasmonic solar cells, plasmonic polarization devices, and optical biosensors. PMID:21466155
Perfect Circular Dichroic Metamirrors
Wang, Zuojia; Liu, Yongmin
2015-01-01
In nature, the beetle Chrysina gloriosa derives its iridescence by selectively reflecting left-handed circularly polarized light only. Here, for the first time, we introduce and demonstrate the optical analogue based on an ultrathin metamaterial, which we term circular dichroic metamirror. A general method to design the circular dichroic metasmirror is presented under the framework of Jones calculus. It is analytically shown that the metamirror can be realized by two layers of anisotropic metamaterial structures, in order to satisfy the required simultaneous breakings of n-fold rotational (n>2) and mirror symmetries. We design an infrared metamirror, which shows perfect reflectance for left-handed circularly polarized light without reversing its handedness, while almost completely absorbs right-handed circularly polarized light. These findings offer new methodology to realize novel chiral optical devices for a variety of applications, including polarimetric imaging, molecular spectroscopy, as well as quantum ...
Pewsey, Arthur; Ruxton, Graeme D
2013-01-01
Circular Statistics in R provides the most comprehensive guide to the analysis of circular data in over a decade. Circular data arise in many scientific contexts whether it be angular directions such as: observed compass directions of departure of radio-collared migratory birds from a release point; bond angles measured in different molecules; wind directions at different times of year at a wind farm; direction of stress-fractures in concretebridge supports; longitudes of earthquake epicentres or seasonal and daily activity patterns, for example: data on the times of day at which animals are c
Discriminating chaotic and stochastic dynamics through the permutation spectrum test
Energy Technology Data Exchange (ETDEWEB)
Kulp, C. W., E-mail: Kulp@lycoming.edu [Department of Astronomy and Physics, Lycoming College, Williamsport, Pennsylvania 17701 (United States); Zunino, L., E-mail: lucianoz@ciop.unlp.edu.ar [Centro de Investigaciones Ópticas (CONICET La Plata—CIC), C.C. 3, 1897 Gonnet (Argentina); Departamento de Ciencias Básicas, Facultad de Ingeniería, Universidad Nacional de La Plata (UNLP), 1900 La Plata (Argentina)
2014-09-01
In this paper, we propose a new heuristic symbolic tool for unveiling chaotic and stochastic dynamics: the permutation spectrum test. Several numerical examples allow us to confirm the usefulness of the introduced methodology. Indeed, we show that it is robust in situations in which other techniques fail (intermittent chaos, hyperchaotic dynamics, stochastic linear and nonlinear correlated dynamics, and deterministic non-chaotic noise-driven dynamics). We illustrate the applicability and reliability of this pragmatic method by examining real complex time series from diverse scientific fields. Taking into account that the proposed test has the advantages of being conceptually simple and computationally fast, we think that it can be of practical utility as an alternative test for determinism.
PARALLEL HYBRID OPTIMIZATION METHODS FOR PERMUTATION BASED PROBLEMS
Mehdi, Malika
2011-01-01
La résolution efficace de problèmes d'optimisation a permutation de grande taille nécessite le développement de méthodes hybrides complexes combinant différentes classes d'algorithmes d'optimisation. L'hybridation des metaheuristiques avec les méthodes exactes arborescentes, tel que l'algorithme du branch-and-bound (B&B), engendre une nouvelle classe d'algorithmes plus efficace que ces deux classes de méthodes utilisées séparément. Le défi principal dans le développement de telles méthodes co...
Discriminating chaotic and stochastic dynamics through the permutation spectrum test
International Nuclear Information System (INIS)
In this paper, we propose a new heuristic symbolic tool for unveiling chaotic and stochastic dynamics: the permutation spectrum test. Several numerical examples allow us to confirm the usefulness of the introduced methodology. Indeed, we show that it is robust in situations in which other techniques fail (intermittent chaos, hyperchaotic dynamics, stochastic linear and nonlinear correlated dynamics, and deterministic non-chaotic noise-driven dynamics). We illustrate the applicability and reliability of this pragmatic method by examining real complex time series from diverse scientific fields. Taking into account that the proposed test has the advantages of being conceptually simple and computationally fast, we think that it can be of practical utility as an alternative test for determinism
Permutation group SN and large Nc excited baryons
International Nuclear Information System (INIS)
We study the excited baryon states for an arbitrary number of colors Nc from the perspective of the permutation group SN of N objects. Classifying the transformation properties of states and quark-quark interaction operators under SN allows a general analysis of the spin-flavor structure of the mass operator of these states, in terms of a few unknown constants parametrizing the unknown spatial structure. We explain how to perform the matching calculation of a general two-body quark-quark interaction onto the operators of the 1/Nc expansion. The inclusion of core and excited quark operators is shown to be necessary. Considering the case of the negative parity L=1 states transforming in the MS of SN, we discuss the matching of the one-gluon and the Goldstone-boson exchange interactions.
Geological applications of multi-response permutation procedures
Orlowski, L.A.; Grundy, W.D.; Mielke, P.W., Jr.; Schumm, S.A.
1993-01-01
The multi-purpose permutation procedures (MRPP) test statistic is designed to analyze multivariate data at the ordinal or higher levels. It is based on the weighted averages of symmetric distance functions over all paired objects within a priori disjoint groups of objects from a finite population of objects where each object's response is a point in an r-dimensional space. Thus, the arguments of each r-dimensional point correspond to the r measured responses of each object in the finite population of objects. The null hypothesis underlying MRPP is that the observed sample of objects within groups of a specified size structure is randomly obtained from the pooled collection of objects comprising the finite population. The procedure is used to test the presumed geomorphic differences among three reaches of the Lower Mississippi River. A combination of the proposed reaches is favored and several variable-based reach configurations are proposed. ?? 1993 International Association for Mathernatical Geology.
Permutation symmetry and the origin of fermion mass hierarchy
International Nuclear Information System (INIS)
A realization of the ''flavor-democracy'' approach to quark and lepton masses is provided in the context of the standard model with a horizontal S3 permutation symmetry. In this model, t and b quarks pick up mass at the tree level, c, s-quark and τ-lepton masses arise at the one-loop level, u, d, and μ masses at the two-loop level, and the electron mass at the three-loop level, thus reproducing the observed hierarchial structure without fine tuning of the Yukawa couplings. The pattern of quark mixing angles also emerges naturally, with Vus,Vcb∼O(ε), Vub∼O(ε2), where ε is a loop expansion parameter
Matrices with restricted entries and q-analogues of permutations
Lewis, Joel Brewster; Morales, Alejandro H; Panova, Greta; Sam, Steven V; Zhang, Yan
2010-01-01
We study the functions that count matrices of given rank over a finite field with specified positions equal to zero. We show that these matrices are $q$-analogues of permutations with certain restricted values. We obtain a simple closed formula for the number of invertible matrices with zero diagonal, a $q$-analogue of derangements, and a curious relationship between invertible skew-symmetric matrices and invertible symmetric matrices with zero diagonal. In addition, we provide recursions to enumerate matrices and symmetric matrices with zero diagonal by rank, and we frame some of our results in the context of Lie theory. Finally, we provide a brief exposition of polynomiality results for enumeration questions related to those mentioned, and give several open questions.
Efficient SAT Techniques for Relative Encoding of Permutations with Constraints
Velev, Miroslav N.; Gao, Ping
We present new techniques for relative SAT encoding of permutations with constraints, resulting in improved scalability compared to the previous approach by Prestwich, when applied to searching for Hamiltonian cycles. We observe that half of the ordering variables and two-thirds of the transitivity constraints can be eliminated. We exploit minimal enumeration of transitivity, based on 12 triangulation heuristics, and 11 heuristics for selecting the first node in the Hamiltonian cycle. We propose the use of inverse transitivity constraints. We achieve 3 orders of magnitude average speedup on satisfiable random graphs from the phase transition region, 2 orders of magnitude average speedup on unsatisfiable random graphs, and up to 4 orders of magnitude speedup on satisfiable structured graphs from the DIMACS graph coloring instances.
Breaking of flavor permutational symmetry and the CKM matrix
International Nuclear Information System (INIS)
The phase equivalence of the theoretical quark mixing matrix Vth derived from the breaking of the flavor permutational symmetry and the standard parameterization VPDG advocated by the Particle Data Group is explicity exhibited. From here, we derive exact explicit expressions for the three mixing angles θ12,θ13,θ23, and the CP violating phase δ13 in terms of the quark mass ratios (mu/mt,mc/mt,md/mb,ms/mb) and the parameters Z*1/2 and Φ* characterizing the preferred symmetry breaking pattern. The computed values for the CP violating phase and the mixing angles are: δ13*=75 deg., sin θ12*=0.221, sin θ13*=0.0034, and sin θ23*=0.040, which coincide almost exactly with the central values of the experimentally determined quantities
Permutation Centralizer Algebras and Multi-Matrix Invariants
Mattioli, Paolo
2016-01-01
We introduce a class of permutation centralizer algebras which underly the combinatorics of multi-matrix gauge invariant observables. One family of such non-commutative algebras is parametrised by two integers. Its Wedderburn-Artin decomposition explains the counting of restricted Schur operators, which were introduced in the physics literature to describe open strings attached to giant gravitons and were subsequently used to diagonalize the Gaussian inner product for gauge invariants of 2-matrix models. The structure of the algebra, notably its dimension, its centre and its maximally commuting sub-algebra, is related to Littlewood-Richardson numbers for composing Young diagrams. It gives a precise characterization of the minimal set of charges needed to distinguish arbitrary matrix gauge invariants, which are related to enhanced symmetries in gauge theory. The algebra also gives a star product for matrix invariants. The centre of the algebra allows efficient computation of a sector of multi-matrix correlator...
Refined scale-dependent permutation entropy to analyze systems complexity
Wu, Shuen-De; Wu, Chiu-Wen; Humeau-Heurtier, Anne
2016-05-01
Multiscale entropy (MSE) has become a prevailing method to quantify the complexity of systems. Unfortunately, MSE has a temporal complexity in O(N2) , which is unrealistic for long time series. Moreover, MSE relies on the sample entropy computation which is length-dependent and which leads to large variance and possible undefined entropy values for short time series. Here, we propose and introduce a new multiscale complexity measure, the refined scale-dependent permutation entropy (RSDPE). Through the processing of different kinds of synthetic data and real signals, we show that RSDPE has a behavior close to the one of MSE. Furthermore, RSDPE has a temporal complexity in O(N) . Finally, RSDPE has the advantage of being much less length-dependent than MSE. From all this, we conclude that RSDPE over-performs MSE in terms of computational cost and computational accuracy.
Chen, Zhi-Jie; Tian, Ziqi; Kallio, Karen; Oleson, April L; Ji, Ao; Borchardt, Dan; Jiang, De-En; Remington, S James; Ai, Hui-Wang
2016-04-13
Boronic acid and esters have been extensively utilized for molecular recognition and chemical sensing. We recently reported a genetically encoded peroxynitrite (ONOO(-))-specific fluorescent sensor, pnGFP, based on the incorporation of a boronic acid moiety into a circularly permuted green fluorescent protein (cpGFP) followed by directed protein evolution. Different from typical arylboronic acids and esters, the chromophore of pnGFP is unreactive to millimolar concentrations of hydrogen peroxide (H2O2). The focus of this study is to explore the mechanism for the observed unusual chemoselectivity of pnGFP toward peroxynitrite over hydrogen peroxide by using site-directed mutagenesis, X-ray crystallography, (11)B NMR, and computational analysis. Our data collectively support that a His residue on the protein scaffold polarizes a water molecule to induce the formation of an sp(3)-hybridized boron in the chromophore, thereby tuning the reactivity of pnGFP with various reactive oxygen and nitrogen species (ROS/RNS). Our study demonstrates the first example of tunable boron chemistry in a folded nonnative protein, which offers wide implications in designing selective chemical probes. PMID:27019313
Differential cryptanalysis of round-reduced PRINTcipher: Computing roots of permutations
DEFF Research Database (Denmark)
Abdelraheem, Mohamed Ahmed; Leander, Gregor; Zenner, Erik
2011-01-01
At CHES 2010, the new block cipher PRINTcipher was presented. In addition to using an xor round key as is common practice for round-based block ciphers, PRINTcipher also uses key-dependent permutations. While this seems to make differential cryptanalysis difficult due to the unknown bit permutati......At CHES 2010, the new block cipher PRINTcipher was presented. In addition to using an xor round key as is common practice for round-based block ciphers, PRINTcipher also uses key-dependent permutations. While this seems to make differential cryptanalysis difficult due to the unknown bit...... permutations, we show in this paper that this is not the case. We present two differential attacks that successfully break about half of the rounds of PRINTcipher, thereby giving the first cryptanalytic result on the cipher. In addition, one of the attacks is of independent interest, since it uses a mechanism...... to compute roots of permutations. If an attacker knows the many-round permutation πr, the algorithm can be used to compute the underlying single-round permutation π. This technique is thus relevant for all iterative ciphers that deploy key-dependent permutations. In the case of PRINTcipher, it can be...
Matrix Schur functions, permutation matrices, and young operators as inner product spaces
International Nuclear Information System (INIS)
An inner product is defined on the space of permutation matrices and the space of matrices dual to the permutation matrices is given. The relationship of permutation matrices to the expansion of matrices of fixed line-sum is discussed. This inner product carries over to the space of linear Young operators, as does the notion of the dual space. Motivation from physics for considering such algebraic structures is also given; in particular, the real, orthogonal, irreducible representations of the symmetric group originating from the matrix Schur functions are given.
Permutation-inversion group of fullerite C70 in the intermediate phase
International Nuclear Information System (INIS)
The permutation-inversion symmetry group of fullerite C70 in the intermediate phase (at temperatures 270 K 70 in a nonrigid crystal are generated. Their irreducible representations compatible with the principle of symmetry of wave functions with respect to the permutations of identical nuclei are found. Group-theoretical classification of quantum-mechanical states of a rotating molecule and a crystal in the intermediate phase of fullerite C70 is made. The selection rules for electronic and IR spectra in terms of the irreducible representations of the permutation-inversion group are found. (orig.)
How to write a permutation as a product of involutions (and why you might care)
Petersen, T Kyle
2012-01-01
It is well-known that any permutation can be written as a product of two involutions. We provide an explicit formula for the number of ways to do so, depending only on the cycle type of the permutation. In many cases, these numbers are sums of absolute values of irreducible characters of the symmetric group evaluated at the same permutation, although apart from the case where all cycles are the same size, we have no good explanation for why this should be so.
Orders induced by segments in floorplan partitions and (2-14-3,3-41-2)-avoiding permutations
Asinowski, Andrei; Bousquet-Mélou, Mireille; Mansour, Toufik; Pinter, Ron
2010-01-01
Floorplan partitions are certain tilings of a rectangle by other rectangles. There are natural ways to order their elements (rectangles and segments). In particular, Ackerman, Barequet, and Pinter studied a pair of orders induced by neighborhood relations between rectangles of a floorplan partition, and obtained a natural bijection between these pairs and (2-41-3, 3-14-2)-avoiding permutations (also known as Baxter permutations). In the present paper, we study a pair of orders induced by neighborhood relations between segments of a floorplan partition. We obtain a natural bijection between these pairs and another family of permutations, namely (2-14-3,3-41-2)-avoiding permutations. We also enumerate these permutations, investigate relations between the two kinds of pairs of orders --- and correspondingly, between (2-14-3,3-41-2)-avoiding permutations and Baxter permutations --- and study the special case of "guillotine" partitions.
Dickie, David A; Mikhael, Shadia; Job, Dominic E; Wardlaw, Joanna M; Laidlaw, David H; Bastin, Mark E
2015-12-01
Permutation testing has been widely implemented in voxel-based morphometry (VBM) tools. However, this type of non-parametric inference has yet to be thoroughly compared with traditional parametric inference in VBM studies of brain structure. Here we compare both types of inference and investigate what influence the number of permutations in permutation testing has on results in an exemplar study of how gray matter proportion changes with age in a group of working age adults. High resolution T1-weighted volume scans were acquired from 80 healthy adults aged 25-64years. Using a validated VBM procedure and voxel-based permutation testing for Pearson product-moment coefficient, the effect sizes of changes in gray matter proportion with age were assessed using traditional parametric and permutation testing inference with 100, 500, 1000, 5000, 10000 and 20000 permutations. The statistical significance was set at PPFDR<0.05) declines in gray matter proportion with age identified with permutation testing inference (N≈6000) were approximately twice the size of those identified with parametric inference (N=3221voxels). Permutation testing with 10000 (N=6251voxels) and 20000 (N=6233voxels) permutations produced clusters that were generally consistent with each other. However, with 1000 permutations there were approximately 20% more statistically significant voxels (N=7117voxels) than with ≥10000 permutations. Permutation testing inference may provide a more sensitive method than traditional parametric inference for identifying age-related differences in gray matter proportion. Based on the results reported here, at least 10000 permutations should be used in future univariate VBM studies investigating age related changes in gray matter to avoid potential false findings. Additional studies using permutation testing in large imaging databanks are required to address the impact of model complexity, multivariate analysis, number of observations, sampling bias and data quality
Predecessor and permutation existence problems for sequential dynamical systems
Energy Technology Data Exchange (ETDEWEB)
Barrett, C. L. (Christopher L.); Hunt, H. B. (Harry B.); Marathe, M. V. (Madhav V.); Rosenkrantz, D. J. (Daniel J.); Stearns, R. E. (Richard E.)
2002-01-01
A class of finite discrete dynamical systems, called Sequential Dynamical Systems (SDSs), was introduced in BMR99, BR991 as a formal model for analyzing simulation systems. An SDS S is a triple (G, F,n ),w here (i) G(V,E ) is an undirected graph with n nodes with each node having a state, (ii) F = (fi, fi, . . ., fn), with fi denoting a function associated with node ui E V and (iii) A is a permutation of (or total order on) the nodes in V, A configuration of an SDS is an n-vector ( b l, bz, . . ., bn), where bi is the value of the state of node vi. A single SDS transition from one configuration to another is obtained by updating the states of the nodes by evaluating the function associated with each of them in the order given by n. Here, we address the complexity of two basic problems and their generalizations for SDSs. Given an SDS S and a configuration C, the PREDECESSOR EXISTENCE (or PRE) problem is to determine whether there is a configuration C' such that S has a transition from C' to C. (If C has no predecessor, C is known as a garden of Eden configuration.) Our results provide separations between efficiently solvable and computationally intractable instances of the PRE problem. For example, we show that the PRE problem can be solved efficiently for SDSs with Boolean state values when the node functions are symmetric and the underlying graph is of bounded treewidth. In contrast, we show that allowing just one non-symmetric node function renders the problem NP-complete even when the underlying graph is a tree (which has a treewidth of 1). We also show that the PRE problem is efficiently solvable for SDSs whose state values are from a field and whose node functions are linear. Some of the polynomial algorithms also extend to the case where we want to find an ancestor configuration that precedes a given configuration by a logarithmic number of steps. Our results extend some of the earlier results by Sutner [Su95] and Green [@87] on the complexity of
Compact waveguide circular polarizer
Energy Technology Data Exchange (ETDEWEB)
Tantawi, Sami G.
2016-08-16
A multi-port waveguide is provided having a rectangular waveguide that includes a Y-shape structure with first top arm having a first rectangular waveguide port, a second top arm with second rectangular waveguide port, and a base arm with a third rectangular waveguide port for supporting a TE.sub.10 mode and a TE.sub.20 mode, where the end of the third rectangular waveguide port includes rounded edges that are parallel to a z-axis of the waveguide, a circular waveguide having a circular waveguide port for supporting a left hand and a right hand circular polarization TE.sub.11 mode and is coupled to a base arm broad wall, and a matching feature disposed on the base arm broad wall opposite of the circular waveguide for terminating the third rectangular waveguide port, where the first rectangular waveguide port, the second rectangular waveguide port and the circular waveguide port are capable of supporting 4-modes of operation.
Li, Zhendong; Liu, Wenjian
2016-01-01
Complicated mathematical equations involving tensors with permutation symmetries are frequently encountered in fields such as quantum chemistry, e.g., those in coupled cluster theories and derivatives of wavefunction parameters. In automatic derivations of these equations, a key step is the collection of product terms that can be found identical by using permutation symmetries or relabelling dummy indices. In the present work, we define a canonical form for a general tensor product in the presence of permutation symmetries as a result of the classification of all tensor products from a group theoretical point of view. To make such definition of practical use, we provide an efficient algorithm to compute the canonical form by combining the classical backtrack search for permutation groups and the idea of partitions used in graph isomorphism algorithms. The resulted algorithm can compute canonical forms and generators of the automorphism groups of tensor expressions. Moreover, for tensor products with external ...
Method of protection of the confidential information with use of permutable functions
Stella G. Spirina
2011-01-01
In work it is offered recurenting a method of construction of permutable whole functions in fields Gаluа GF from (p) to the set degree on the basis of basic as question of protection of the confidential information.
Levin, Mark Sh
2011-01-01
The paper describes a general glance to the use of element exchange techniques for optimization over permutations. A multi-level description of problems is proposed which is a fundamental to understand nature and complexity of optimization problems over permutations (e.g., ordering, scheduling, traveling salesman problem). The description is based on permutation neighborhoods of several kinds (e.g., by improvement of an objective function). Our proposed operational digraph and its kinds can be considered as a way to understand convexity and polynomial solvability for combinatorial optimization problems over permutations. Issues of an analysis of problems and a design of hierarchical heuristics are discussed. The discussion leads to a multi-level adaptive algorithm system which analyzes an individual problem and selects/designs a solving strategy (trajectory).
Computing the Jones index of quadratic permutation endomorphisms of O_{2}
DEFF Research Database (Denmark)
Szymanski, Wojciech; Conti, Roberto
2009-01-01
We compute the index of the type III1/2 factors arising from endomorphisms of the Cuntz algebra O2 associated to the rank-two permutation matrices. Udgivelsesdato: January......We compute the index of the type III1/2 factors arising from endomorphisms of the Cuntz algebra O2 associated to the rank-two permutation matrices. Udgivelsesdato: January...
Complete analysis of extensions of D(n)1 permutation orbifolds
International Nuclear Information System (INIS)
We give the full set of S matrices for extensions of D(n)1 permutation orbifolds, extending our previous work to the yet unknown case of integer spin spinor currents. The main tool is triality of SO(8). We also provide fixed point resolution matrices for spinor currents of D(n)1 permutation orbifolds with n even and not multiple of four, where the spinor currents have half-integer spin.
A Design of New Fast Image Permutation Approach for Food Intellectual-property Protection
Feng Huang; Wei Zou; Qingzheng Li
2015-01-01
The security of food image was important in food intellectual-property protection. Permutation could protect security of image which charged the correlation among adjacent pixels. Some chaotic maps were used in image permutation; act as baker map or some other maps. But the plain image must be square. At the same time the plain image always is stretched to a line firstly. Obviously, it wasted precious time. The study found the pixels location could arrange freely using some new maps without s...
Benchmarch results of a genetic algorithm for non-permutation flowshops using constrained buffers
Färber, Gerrit Hartmut; Coves Moreno, Anna Maria
2006-01-01
This paper presents the performance study of a Genetic Algorithm, for the special case of a mixed model non-permutation flowshop production line, where resequencing is permitted when stations have access to intermittent or centralized resequencing buffers. The access to the buffers is restricted by the number of available buffer places and the physical size of the products. Results from other authors are compared which presented results on permutation sequences [1] or which treat a problem si...
Permutation-equivariant quantum K-theory II. Fixed point localization
Givental, Alexander
2015-01-01
Using projective spaces as examples of toric manifolds, we examine K-theoretic fixed point localization. On the one hand, we will see how the permutation-equivariant theory of the point target space emerges as a necessary ingredient. On the other hand, we will completely characterize the genus-0 permutation-equivariant quantum K-theory of the given toric manifold in terms of such theory for the point, and a certain recursion relation.
On the Similarity of Sets of Permutations and its Applications to Genome Comparison
Bergeron, Anne; Stoye, Jens
2003-01-01
The comparison of genomes with the same gene content relies on our ability to compare permutations, either by measuring how much they differ, or by measuring how much they are alike. With the notable exception of the breakpoint distance, which is based on the concept of conserved adjacencies, measures of distance do not generalize easily to sets of more than two permutations. In this paper, we present a basic unifying notion, conserved intervals, as a powerful generalization of adjacencies, a...
BALANCEDNESS OF THE CLASS OF INFINITE PERMUTATION GAMES AND RELATED CLASSES OF GAMES
Fragnelli, V.; Llorca, N.; Tijs, S.H.
2007-01-01
Recently it is proved that all infinite assignment games have a non-empty core. Using this fact, and a technique suggested by L. S. Shapley for finite permutation games, we prove similar results for infinite permutation games. Infinite transportation games can be interpreted as a generalization of infinite assignment games. We show that infinite transportation games are balanced via a related assignment game. By using certain core elements of infinite transportation games it can be shown that...
Multivariate Multi-Scale Permutation Entropy for Complexity Analysis of Alzheimer’s Disease EEG
Isabella Palamara; Giuseppe Morabito; Alessia Bramanti; Fabio La Foresta; Domenico Labate; Francesco Carlo Morabito
2012-01-01
An original multivariate multi-scale methodology for assessing the complexity of physiological signals is proposed. The technique is able to incorporate the simultaneous analysis of multi-channel data as a unique block within a multi-scale framework. The basic complexity measure is done by using Permutation Entropy, a methodology for time series processing based on ordinal analysis. Permutation Entropy is conceptually simple, structurally robust to noise and artifacts, computationally very fa...
Qiaoning Yang; Jianlin Wang
2016-01-01
Sensor is the core module in signal perception and measurement applications. Due to the harsh external environment, aging, and so forth, sensor easily causes failure and unreliability. In this paper, three kinds of common faults of single sensor, bias, drift, and stuck-at, are investigated. And a fault diagnosis method based on wavelet permutation entropy is proposed. It takes advantage of the multiresolution ability of wavelet and the internal structure complexity measure of permutation entr...
Pattern avoidance and RSK-like algorithms for alternating permutations and Young tableaux
Lewis, Joel Brewster
2009-01-01
We define a class L_{n, k} of permutations that generalizes alternating (up-down) permutations. We then give bijective proofs of certain pattern-avoidance results for this class. The bijections employed include are a modified form of the RSK insertion algorithm and a different bijection with RSK-like properties. As a special case of our results, we give two bijections between the set A_{2n}(1234) of alternating permutations of length 2n with no four-term increasing subsequence and standard Young tableaux of shape (3^n), and between the set A_{2n + 1}(1234) and the standard Young tableaux of shape (3^{n - 1}, 2, 1). This represents the first enumeration of alternating permutations avoiding a pattern of length four. We also extend previous work on doubly-alternating permutations (alternating permutations whose inverses are alternating) to our more general context. The set L_{n, k} may be viewed as the set of reading words of the standard Young tableaux of a certain skew shape. In the last section of the paper, ...
Efficiency and credit ratings: a permutation-information-theory analysis
Fernandez Bariviera, Aurelio; Zunino, Luciano; Belén Guercio, M.; Martinez, Lisana B.; Rosso, Osvaldo A.
2013-08-01
The role of credit rating agencies has been under severe scrutiny after the subprime crisis. In this paper we explore the relationship between credit ratings and informational efficiency of a sample of thirty nine corporate bonds of US oil and energy companies from April 2008 to November 2012. For this purpose we use a powerful statistical tool, relatively new in the financial literature: the complexity-entropy causality plane. This representation space allows us to graphically classify the different bonds according to their degree of informational efficiency. We find that this classification agrees with the credit ratings assigned by Moody’s. In particular, we detect the formation of two clusters, which correspond to the global categories of investment and speculative grades. Regarding the latter cluster, two subgroups reflect distinct levels of efficiency. Additionally, we also find an intriguing absence of correlation between informational efficiency and firm characteristics. This allows us to conclude that the proposed permutation-information-theory approach provides an alternative practical way to justify bond classification.
An approach to permutation symmetry for the electroweak theory
Jora, R; Schechter, J; Jora, Renata; Nasri, Salah; Schechter, Joseph
2006-01-01
The form of the leptonic mixing matrix emerging from experiment has, in the last few years, generated a lot of interest in the so-called tribimaximal type. This form may be naturally associated with the possibility of a discrete permutation symmetry ($S_3$) among the three generations. However, trying to implement this attractive symmetry has resulted in some problems and it seems to have fallen out of favor. We suggest an approach in which the $S_3$ holds to first approximation, somewhat in the manner of the old SU(3) flavor symmetry of the three flavor quark model. We discuss the nature of the perturbations which are the analogs of the Gell-Mann Okubo perturbations in the above case but confine our attention for the most part to the $S_3$ invariant model. We postulate that the $S_3$ invariant mass spectrum consists of non zero masses for the $(\\tau,b,t)$ and zero masses for the other charged fermions but approximately degenerate masses for the three neutrinos. The mixing matrices are assumed to be trivial f...
Four-point functions and the permutation group S4
Eichmann, Gernot; Fischer, Christian S.; Heupel, Walter
2015-09-01
Four-point functions are at the heart of many interesting physical processes. A prime example is the light-by-light scattering amplitude, which plays an important role in the calculation of hadronic contributions to the anomalous magnetic moment of the muon. In the calculation of such quantities one faces the challenge of finding a suitable and well-behaved basis of tensor structures in coordinate and/or momentum space. Provided all (or many) of the external legs represent similar particle content, a powerful tool to construct and organize such bases is the permutation group S4. We introduce an efficient notation for dealing with the irreducible multiplets of S4, and we highlight the merits of this treatment by exemplifying four-point functions with gauge-boson legs such as the four-gluon vertex and the light-by-light scattering amplitude. The multiplet analysis is also useful for isolating the important kinematic regions and the dynamical singularity content of such amplitudes. Our analysis serves as a basis for future efficient calculations of these and similar objects.
Tunneling and Speedup in Permutation-Invariant Quantum Optimization Problem
Albash, Tameem
Tunneling is often claimed to be the key mechanism underlying possible speedups in quantum optimization via the quantum adiabatic algorithm. Restricting ourselves to qubit-permutation invariant problems, we show that tunneling in these problems can be understood using the semi-classical potential derived from the spin-coherent path integral formalism. Using this, we show that the class of problems that fall under Reichardt's bound (1), i.e., have a constant gap and hence can be efficiently solved using the quantum adiabatic algorithm, do not exhibit tunneling in the large system-size limit. We proceed to construct problems that do not fall under Reichardt's bound but numerically have a constant gap and do exhibit tunneling. However, perhaps counter-intuitively, tunneling does not provide the most efficient mechanism for finding the solution to these problems. Instead, an evolution involving a sequence of diabatic transitions through many avoided level-crossings, involving no tunneling, is optimal and outperforms tunneling in the adiabatic regime. In yet another twist, we show that in this case, classical spin-vector dynamics is as efficient as the diabatic quantum evolution (2).
Breaking of flavor permutational symmetry and the CKM matrix
International Nuclear Information System (INIS)
Different ansaetze for the breaking of the flavor permutational symmetry according to SL(3) x SR(3) superset of SL(2) x SR(2) give different Hermitian mass matrices which differ in the symmetry breaking pattern. In this work we obtain a clear and precise indication on the preferred symmetry breaking pattern. The preferred pattern allows us to compute the CKM mixing matrix, the Jarlskog invariant J, and the three inner angles of the unitarity triangle in terms of four quark mass ratios and the CP violating phase Φ. Excellent agreement with the experimentally determined absolute values of the entries in the CKM matrix is obtained for Φ=90 deg. The corresponding computed values of the Jarlskog invariant and the inner angles are J=3.00x10-5, α=84 deg., β=24 deg. and γ=72 deg. in very good agreement with current data on CP violation in the neutral kaon-antikaon system and oscillations in the Bs deg.-B-bars deg. system
A permutation testing framework to compare groups of brain networks
Directory of Open Access Journals (Sweden)
Sean L Simpson
2013-11-01
Full Text Available Brain network analyses have moved to the forefront of neuroimaging research over the last decade. However, methods for statistically comparing groups of networks have lagged behind. These comparisons have great appeal for researchers interested in gaining further insight into complex brain function and how it changes across different mental states and disease conditions. Current comparison approaches generally either rely on a summary metric or on mass-univariate nodal or edge-based comparisons that ignore the inherent topological properties of the network, yielding little power and failing to make network level comparisons. Gleaning deeper insights into normal and abnormal changes in complex brain function demands methods that take advantage of the wealth of data present in an entire brain network. Here we propose a permutation testing framework that allows comparing groups of networks while incorporating topological features inherent in each individual network. We validate our approach using simulated data with known group differences. We then apply the method to functional brain networks derived from fMRI data.
Efficiency and credit ratings: a permutation-information-theory analysis
International Nuclear Information System (INIS)
The role of credit rating agencies has been under severe scrutiny after the subprime crisis. In this paper we explore the relationship between credit ratings and informational efficiency of a sample of thirty nine corporate bonds of US oil and energy companies from April 2008 to November 2012. For this purpose we use a powerful statistical tool, relatively new in the financial literature: the complexity–entropy causality plane. This representation space allows us to graphically classify the different bonds according to their degree of informational efficiency. We find that this classification agrees with the credit ratings assigned by Moody’s. In particular, we detect the formation of two clusters, which correspond to the global categories of investment and speculative grades. Regarding the latter cluster, two subgroups reflect distinct levels of efficiency. Additionally, we also find an intriguing absence of correlation between informational efficiency and firm characteristics. This allows us to conclude that the proposed permutation-information-theory approach provides an alternative practical way to justify bond classification. (paper)
Single-Cycle Bit Permutations with MOMR Execution
Institute of Scientific and Technical Information of China (English)
Ruby B. Lee; Xiao Yang; Zhi-Jie Jerry Shi
2005-01-01
Secure computing paradigms impose new architectural challenges for general-purpose processors. Cryptographic processing is needed for secure communications, storage, and computations. We identify two categories of operations in symmetric-key and public-key cryptographic algorithms that are not common in previous general-purpose workloads:advanced bit operations within a word and multi-word operations. We define MOMR (Multiple Operands Multiple Results)execution or datarich execution as a unified solution to both challenges. It allows arbitrary n-bit permutations to be achieved in one or two cycles, rather than O(n) cycles as in existing RISC processors. It also enables significant acceleration of multiword multiplications needed by public-key ciphers. We propose two implementations of MOMR: one employs only hardware changes while the other uses Instruction Set Architecture (ISA) support. We show that MOMR execution leverages available resources in typical multi-issue processors with minimal additional cost. Multi-issue processors enhanced with MOMR units provide additional speedup over standard multi-issue processors with the same datapath. MOMR is a general architectural solution for word-oriented processor architectures to incorporate datarich operations.
On the permutation combinatorics of worldsheet moduli space
Freidel, Laurent; Ramgoolam, Sanjaye
2014-01-01
Light-cone string diagrams have been used to reproduce the orbifold Euler characteristic of moduli spaces of punctured Riemann surfaces at low genus and with few punctures. Nakamura studied the meromorphic differential introduced by Giddings and Wolpert to characterise light-cone diagrams and introduced a class of graphs related to this differential. These Nakamura graphs were used to parametrise the cells in a light-cone cell decomposition of moduli space. We develop links between Nakamura graphs and realisations of the worldsheet as branched covers. This leads to a development of the combinatorics of Nakamura graphs in terms of permutation tuples. For certain classes of cells, including those of top dimension, there is a simple relation to Belyi maps, which allows us to use results from Hermitian and complex matrix models to give analytic formulae for the counting of cells at arbitrarily high genus. For the most general cells, we develop a new equivalence relation on Hurwitz classes which organises the cell...
A MULTICRITERIA PERMUTATION FLOWSHOP SCHEDULING PROBLEM WITH SETUP TIMES
Directory of Open Access Journals (Sweden)
M.Saravanan
2014-07-01
Full Text Available The permutation flow shop scheduling problem has been completely concentrated on in late decades, both from single objective and additionally from multi-objective points of view. To the best of our information, little has been carried out with respect to the multi-objective flow shop with sequence dependent setup times are acknowledged. As setup times and multi-criteria problems are significant in industry, we must concentrate on this area. We propose a simple and powerful meta-heuristic algorithm as artificial immune system for the sequence dependent setup time’s flow shop problem with several criteria. The objective functions are framed to simultaneously minimize the makespan time, tardiness time, earliness time and total completion time. The proposed approach is in conjunction with the constructive heuristic of Nawaz et al. evaluated using benchmark problems taken from Taillard and compared with the prevailing Simulated annealing approach and B-Grasp approach. Computational experiments indicate that the proposed algorithm is better than the SA approach and B-Grasp approach in all cases and can be very well applied to find better schedule.
Wiimote Experiments: Circular Motion
Kouh, Minjoon; Holz, Danielle; Kawam, Alae; Lamont, Mary
2013-01-01
The advent of new sensor technologies can provide new ways of exploring fundamental physics. In this paper, we show how a Wiimote, which is a handheld remote controller for the Nintendo Wii video game system with an accelerometer, can be used to study the dynamics of circular motion with a very simple setup such as an old record player or a…
International Nuclear Information System (INIS)
Based on one-dimensional single-electron infinite periodic models of trans-polyacetylene, we show analytically that the overall permutation symmetry of nonlinear optical susceptibilities is, although preserved in bound-state molecular systems, no longer generally held in periodic systems. The overall permutation symmetry breakdown provides a natural explanation of the widely observed large deviations of Kleinman symmetry in off-resonant regions of periodic systems. Finally, physical conditions to experimentally test the overall permutation symmetry breakdown are discussed
WHIPPO. WALTER B.; Rohrkaste, G. R.; Miller, John E.
1989-01-01
Shape gauge and associated computer constitute system measuring deviations of large cylinders from roundness. Shaped and held somewhat like crossbow, measures relative locations of three points on surface of large, round object. By making connected series of measurements around periphery technician using gauge determines deviation of object from perfect circularity. Used to measure straightness, roundness, or complicated shapes of such large geometrical objects as surfaces of aircraft and hulls of ships.
Bo, Pengbo
2011-07-01
The most important guiding principle in computational methods for freeform architecture is the balance between cost efficiency on the one hand, and adherence to the design intent on the other. Key issues are the simplicity of supporting and connecting elements as well as repetition of costly parts. This paper proposes so-called circular arc structures as a means to faithfully realize freeform designs without giving up smooth appearance. In contrast to non-smooth meshes with straight edges where geometric complexity is concentrated in the nodes, we stay with smooth surfaces and rather distribute complexity in a uniform way by allowing edges in the shape of circular arcs. We are able to achieve the simplest possible shape of nodes without interfering with known panel optimization algorithms. We study remarkable special cases of circular arc structures which possess simple supporting elements or repetitive edges, we present the first global approximation method for principal patches, and we show an extension to volumetric structures for truly threedimensional designs. © 2011 ACM.
Switchable circular beam deflectors
Shang, Xiaobing; Joshi, Pankaj; Tan, Jin-Yi; De Smet, Jelle; Cuypers, Dieter; Baghdasaryan, Tigran; Vervaeke, Michael; Thienpont, Hugo; De Smet, Herbert
2016-04-01
In this work, we report two types of electrically tunable photonic devices with circularly symmetric polarization independent beam steering performance (beam condensing resp. beam broadening). The devices consist of circular micro grating structures combined with nematic liquid crystal (LC) layers with anti-parallel alignment. A single beam deflector converts a polarized and monochromatic green laser beam (λ =543.5 nm) into a diffraction pattern, with the peak intensity appearing at the third order when 0~{{V}\\text{pp}} is applied and at the zeroth order (no deflection) for voltages above 30~{{V}\\text{pp}} . Depending on the shape of the grating structure (non-inverted or inverted), the deflection is inwards or outwards. Both grating types can be made starting from the same diamond-tooled master mold. A polarized white light beam is symmetrically condensed resp. broadened over 2° in the off state and is passed through unchanged in the on state. By stacking two such devices with mutually orthogonal LC alignment layers, polarization independent switchable circular beam deflectors are realized with a high transmittance (>80%), and with the same beam steering performance as the polarization dependent single devices.
Recollision with circular polarization
Mauger, Francois; Kamor, Adam; Bandrauk, Andre; Chandre, Cristel; Uzer, Turgay
2013-05-01
Since its identification in the 90s, the recollision scenario has revealed to be very helpful in explaining many phenomena in atomic and molecular systems subjected to strong and short laser pulses, and it is now at the core of the strong field physics and attosecond science. For linearly polarized laser fields, the recollision scenario has been able to explain nonsequential double ionization (NSDI), high harmonic generation (HHG) and laser induced diffraction (LIED), just to cite them. The same scenario also predicts the absence of recollision when the field is circularly polarized, therefore leading to the absence of NSDI, HHG or LIED. Recently, the influence of the ellipticity of the laser has drawn an increasing level of interest in the strong field community as it is seen as a way to control the electronic dynamics and, for instance, HHG. Using classical models, the common belief of the absence of recollision with circularly polarized laser fields has been proven wrong. In my talk I will present classical and quantum evidence of the presence of recollision with circular polarization. I will discuss the conditions under which such recollisions happen and what they imply.
A Design of New Fast Image Permutation Approach for Food Intellectual-property Protection
Directory of Open Access Journals (Sweden)
Feng Huang
2015-08-01
Full Text Available The security of food image was important in food intellectual-property protection. Permutation could protect security of image which charged the correlation among adjacent pixels. Some chaotic maps were used in image permutation; act as baker map or some other maps. But the plain image must be square. At the same time the plain image always is stretched to a line firstly. Obviously, it wasted precious time. The study found the pixels location could arrange freely using some new maps without stretching and those also could encrypt rectangle images not only square image. The ideas of maps were: firstly the plain image was divided into two halves. Using two different scanning methods it could stretch the halves to two different lines. Then it inserted the pixels of a line into the adjacent pixels of another line in order. Lastly the new line could be fold to a new image. For different of scanning methods, it got some different map patterns. A permutation approach was developed which used those patterns. It used decimal numbers as the keys and could permute rectangle images easily. The permutation process was quite fast and enough safe. Deciphering process was an invertible process using the same keys. Some studies proved that high correlation among adjacent pixels was rapidly charged. The approach could satisfy the most security requirements in Internet.
Numerical and experimental study of the effects of noise on the permutation entropy
Quintero-Quiroz, C; Torrent, M C; Masoller, Cristina
2015-01-01
We analyze the effects of noise on the permutation entropy of dynamical systems. We take as numerical examples the logistic map and the R\\"ossler system. Upon varying the noise strengthfaster, we find a transition from an almost-deterministic regime, where the permutation entropy grows slower than linearly with the pattern dimension, to a noise-dominated regime, where the permutation entropy grows faster than linearly with the pattern dimension. We perform the same analysis on experimental time-series by considering the stochastic spiking output of a semiconductor laser with optical feedback. Because of the experimental conditions, the dynamics is found to be always in the noise-dominated regime. Nevertheless, the analysis allows to detect regularities of the underlying dynamics. By comparing the results of these three different examples, we discuss the possibility of determining from a time series whether the underlying dynamics is dominated by noise or not.
Six-qubit permutation-based decoherence-free orthogonal basis
International Nuclear Information System (INIS)
There is a natural orthogonal basis of the 6-qubit decoherence-free (DF) space robust against collective noise. Interestingly, most of the basis states can be obtained from one another just permuting qubits. This property (a) is useful for encoding qubits in DF subspaces, (b) allows the implementation of the Bennett-Brassard 1984 (BB84) protocol in DF subspaces just permuting qubits, which completes the method for quantum key distribution using DF states proposed by Boileau et al. [Phys. Rev. Lett. 92, 017901 (2004)], and (c) points out that there is only one 6-qubit DF state which is essentially new (not obtained by permutations) and therefore constitutes an interesting experimental challenge
International Nuclear Information System (INIS)
A rigorous, general, and simple method to fit global and permutation invariant potential energy surfaces (PESs) using neural networks (NNs) is discussed. This so-called permutation invariant polynomial neural network (PIP-NN) method imposes permutation symmetry by using in its input a set of symmetry functions based on PIPs. For systems with more than three atoms, it is shown that the number of symmetry functions in the input vector needs to be larger than the number of internal coordinates in order to include both the primary and secondary invariant polynomials. This PIP-NN method is successfully demonstrated in three atom-triatomic reactive systems, resulting in full-dimensional global PESs with average errors on the order of meV. These PESs are used in full-dimensional quantum dynamical calculations
Security enhanced optical encryption system by random phase key and permutation key.
He, Mingzhao; Tan, Qiaofeng; Cao, Liangcai; He, Qingsheng; Jin, Guofan
2009-12-01
Conventional double random phase encoding (DRPE) encrypts plaintext to white noise-like ciphertext which may attract attention of eavesdroppers, and recent research reported that DRPE is vulnerable to various attacks. Here we propose a security enhanced optical encryption system that can hide the existence of secret information by watermarking. The plaintext is encrypted using iterative fractional Fourier transform with random phase key, and ciphertext is randomly permuted with permutation key before watermarking. Cryptanalysis shows that linearity of the security system has been broken and the permutation key prevent the attacker from accessing the ciphertext in various attacks. A series of simulations have shown the effectiveness of this system and the security strength is enhanced for invisibility, nonlinearity and resistance against attacks. PMID:20052170
Directory of Open Access Journals (Sweden)
Tejashree Damle
2012-03-01
Full Text Available Microarray is the gene expression data that represent gene in different biological states. Methods are needed to determine the significance of these changes while accounting for the enormous number of genes. Significance analysis of microarrays (SAM is a statistical technique for determining whether changes in gene expression are statistically significant. During the SAM procedure permutation of microarray data is considered to observe the changes in the overall expression level of data. With increasing number of permutations false discovery rate for gene set varies. In our work we took microarray data of Normal Glucose Tolerance (NGT, and Diabetes Mellitus (DM Type II. In this paper we proposed the result of permutations during execution of SAM algorithm. The hierarchical clustering is applied for observing expression levels of significant data and visualize it with heat map.
Multiple comparisons permutation test for image based data mining in radiotherapy
International Nuclear Information System (INIS)
Comparing incidental dose distributions (i.e. images) of patients with different outcomes is a straightforward way to explore dose-response hypotheses in radiotherapy. In this paper, we introduced a permutation test that compares images, such as dose distributions from radiotherapy, while tackling the multiple comparisons problem. A test statistic Tmax was proposed that summarizes the differences between the images into a single value and a permutation procedure was employed to compute the adjusted p-value. We demonstrated the method in two retrospective studies: a prostate study that relates 3D dose distributions to failure, and an esophagus study that relates 2D surface dose distributions of the esophagus to acute esophagus toxicity. As a result, we were able to identify suspicious regions that are significantly associated with failure (prostate study) or toxicity (esophagus study). Permutation testing allows direct comparison of images from different patient categories and is a useful tool for data mining in radiotherapy
A Fast Algorithm for Permutation Pattern Matching Based on Alternating Runs
Bruner, Marie-Louise
2012-01-01
The NP-complete Permutation Pattern Matching problem asks whether a permutation P can be matched into a permutation T. A matching is an order-preserving embedding of P into T. We present a fixed-parameter algorithm solving this problem with an exponential worst-case runtime of O*(1.79^run(T)), where run(T) denotes the number of alternating runs of T. This is the first algorithm that improves upon the O*(2^n) runtime required by brute-force search without imposing restrictions on P and T. Furthermore we prove that -- under standard complexity theoretic assumptions -- such a fixed-parameter tractability result is not possible for run(P).
Gao, Steven; Zhu, Fuguo
2013-01-01
This book presents a comprehensive insight into the design techniques for different types of CP antenna elements and arrays In this book, the authors address a broad range of topics on circularly polarized (CP) antennas. Firstly, it introduces to the reader basic principles, design techniques and characteristics of various types of CP antennas, such as CP patch antennas, CP helix antennas, quadrifilar helix antennas (QHA), printed quadrifilar helix antennas (PQHA), spiral antenna, CP slot antennas, CP dielectric resonator antennas, loop antennas, crossed dipoles, monopoles and CP horns. Adva
Antennas on circular cylinders
DEFF Research Database (Denmark)
Knudsen, H. L.
1959-01-01
antenna in a circular cylinder. By a procedure similar to the one used by Silver and Saunders, expressions have been derived for the field radiated from an arbitrary surface current distribution on a cylinder surface coaxial with a perfectly conducting cylinder. The cases where the space between the two...... cylindrical surfaces have the sane characteristic constants and different constants are treated separately. Extensive numerical computations of the field radiated from the slot antennas described here are being carried out, but no numerical results are yet available...
International Nuclear Information System (INIS)
Matrix elements of unitary group generators between spin-adapted antisymmetric states are shown to be proportional to spin matrix elements of so-called line-up permutations. The proportionality factor is given explicitly as a simple function of the orbital occupation numbers. If one bases the theory on ordered orbital products, the line-up permutations are given a priori. The final formulas have a very simple structure; this property is a direct consequence of the fact that the spin functions have been taken to be geminally antisymmetric. 1 table
Surface plasmon resonance coupled circular dichroism of DNA–gold nanorods assembly
International Nuclear Information System (INIS)
Linker mediated self-assembly of gold nanoparticles is emerging as an interesting strategy for construction of hybrid nanoscale systems with enhanced plasmonic circular dichroism (PCD) signals. Herein, gold nanorods were assembled via DNA linker to investigate the possibility of signal enhancement. Assemblies were characterized by UV–visible, fluorescence, dynamic light scattering and circular dichroism (CD) spectroscopy. Hybridization of complementary strands resulted in PCD signal enhancement, which was further monitored by the increase of real time PicoGreen fluorescence intensity. Impressively, such changes in the real time fluorescence and plasmonic CD responses could be used as a new detection method for ultrasensitive sensors. (paper)
Pi, Archimedes and circular splines
Sablonnière, Paul
2013-01-01
In the present paper, we give approximate values of $\\pi$ deduced from the areas of inscribed and circumscribed quadratic and cubic circular splines. Similar results on circular splines of higher degrees and higher approximation orders can be obtained in the same way. We compare these values to those obtained by computing the {\\em perimeters} of those circular splines. We observe that the former are much easier to compute than the latter and give results of the same order. It also appears tha...
Counting descent pairs with prescribed colors in the colored permutation groups
Bagno, Eli; Garber, David; Mansour, Toufik
2007-01-01
We define new statistics, (c, d)-descents, on the colored permutation groups Z_r \\wr S_n and compute the distribution of these statistics on the elements in these groups. We use some combinatorial approaches, recurrences, and generating functions manipulations to obtain our results.
Application of quantum algorithms to the study of permutations and group automorphisms
International Nuclear Information System (INIS)
We discuss three applications of efficient quantum algorithms to determining properties of permutations and group automorphisms. The first uses the Bernstein-Vazirani algorithm to determine an unknown homomorphism from Zp-1m to Aut(Zp) where p is prime. The remaining two make use of modifications of the Grover search algorithm. The first finds the fixed point of a permutation or an automorphism (assuming it has only one besides the identity). It can be generalized to find cycles of a specified size for permutations or orbits of a specified size for automorphisms. The second finds which of a set of permutations or automorphisms maps one particular element of a set or group onto another. This has relevance to the conjugacy problem for groups. We show how two of these algorithms can be implemented via programmable quantum processors. This approach opens new perspectives in quantum information processing when both the data and the programs are represented by states of quantum registers. In particular, quantum programs that specify control over data can be treated using methods of quantum information theory
Brusco, Michael J.; Kohn, Hans-Friedrich; Stahl, Stephanie
2008-01-01
Dynamic programming methods for matrix permutation problems in combinatorial data analysis can produce globally-optimal solutions for matrices up to size 30x30, but are computationally infeasible for larger matrices because of enormous computer memory requirements. Branch-and-bound methods also guarantee globally-optimal solutions, but computation…
The coupling analysis between stock market indices based on permutation measures
Shi, Wenbin; Shang, Pengjian; Xia, Jianan; Yeh, Chien-Hung
2016-04-01
Many information-theoretic methods have been proposed for analyzing the coupling dependence between time series. And it is significant to quantify the correlation relationship between financial sequences since the financial market is a complex evolved dynamic system. Recently, we developed a new permutation-based entropy, called cross-permutation entropy (CPE), to detect the coupling structures between two synchronous time series. In this paper, we extend the CPE method to weighted cross-permutation entropy (WCPE), to address some of CPE's limitations, mainly its inability to differentiate between distinct patterns of a certain motif and the sensitivity of patterns close to the noise floor. It shows more stable and reliable results than CPE does when applied it to spiky data and AR(1) processes. Besides, we adapt the CPE method to infer the complexity of short-length time series by freely changing the time delay, and test it with Gaussian random series and random walks. The modified method shows the advantages in reducing deviations of entropy estimation compared with the conventional one. Finally, the weighted cross-permutation entropy of eight important stock indices from the world financial markets is investigated, and some useful and interesting empirical results are obtained.
Analyzing Permutations for AES-like Ciphers: Understanding ShiftRows
DEFF Research Database (Denmark)
Beierle, Christof; Jovanovic, Philipp; Lauridsen, Martin Mehl;
2015-01-01
the operation resembling ShiftRows has never been studied in depth. Here, we provide the first structured study of the influence of ShiftRows-like operations, or more generally, word-wise permutations, in AES-like ciphers with respect to diffusion properties and resistance towards differential- and...
EPEPT: A web service for enhanced P-value estimation in permutation tests
Directory of Open Access Journals (Sweden)
Knijnenburg Theo A
2011-10-01
Full Text Available Abstract Background In computational biology, permutation tests have become a widely used tool to assess the statistical significance of an event under investigation. However, the common way of computing the P-value, which expresses the statistical significance, requires a very large number of permutations when small (and thus interesting P-values are to be accurately estimated. This is computationally expensive and often infeasible. Recently, we proposed an alternative estimator, which requires far fewer permutations compared to the standard empirical approach while still reliably estimating small P-values 1. Results The proposed P-value estimator has been enriched with additional functionalities and is made available to the general community through a public website and web service, called EPEPT. This means that the EPEPT routines can be accessed not only via a website, but also programmatically using any programming language that can interact with the web. Examples of web service clients in multiple programming languages can be downloaded. Additionally, EPEPT accepts data of various common experiment types used in computational biology. For these experiment types EPEPT first computes the permutation values and then performs the P-value estimation. Finally, the source code of EPEPT can be downloaded. Conclusions Different types of users, such as biologists, bioinformaticians and software engineers, can use the method in an appropriate and simple way. Availability http://informatics.systemsbiology.net/EPEPT/
Circular PVDF Airborne Transducer
Institute of Scientific and Technical Information of China (English)
JIAO Li-hua; XU Li-mei; HONG Hu
2007-01-01
With the required increased audio pressure of the parametric ultrasonic transducer array and the difficulty to theoretically analyse the complex ultrasonic structure in audio beam application, an computafionally efficient model is desired to describe the characteristic of the parametric ultrasonic transducer array for the system design and optimization. By applying the symmetry boundary conditions at the mid-plane in the thickness direction, a finite element model based on the half thickness simplification is presented to analyze the parametric circular transducer which is designed by gluing the poly Vinylidene fluoride film (PVDF). The validity of the proposed model is confirmed by a comparison of finite element aalysis results with the theoretical value and experimental data, which show that they are making a good agreement with each other.
Operational circular No. 1 (Rev. 1) – Operational circulars
HR Department
2011-01-01
Operational Circular No. 1 (Rev. 1) is applicable to members of the personnel and other persons concerned. Operational Circular No. 1 (Rev. 1) entitled "Operational circulars", approved following discussion at the Standing Concertation Committee meeting on 4 May 2011, is available on the intranet site of the Human Resources Department: https://hr-docs.web.cern.ch/hr-docs/opcirc/opcirc.asp It cancels and replaces Operational Circular No. 1 entitled "Operational Circulars” of December 1996. This new version clarifies, in particular, that operational circulars do not necessarily arise from the Staff Rules and Regulations, and the functional titles have been updated to bring them into line with the current CERN organigram. Department Head Office
Implementing circularity using partial evaluation
DEFF Research Database (Denmark)
Lawall, Julia Laetitia
2001-01-01
Complex data dependencies can often be expressed concisely by defining a variable in terms of part of its own value. Such a circular reference can be naturally expressed in a lazy functional language or in an attribute grammar. In this paper, we consider circular references in the context of an...
Haruna, T.; Nakajima, K.
2013-06-01
The duality between values and orderings is a powerful tool to discuss relationships between various information-theoretic measures and their permutation analogues for discrete-time finite-alphabet stationary stochastic processes (SSPs). Applying it to output processes of hidden Markov models with ergodic internal processes, we have shown in our previous work that the excess entropy and the transfer entropy rate coincide with their permutation analogues. In this paper, we discuss two permutation characterizations of the two measures for general ergodic SSPs not necessarily having the Markov property assumed in our previous work. In the first approach, we show that the excess entropy and the transfer entropy rate of an ergodic SSP can be obtained as the limits of permutation analogues of them for the N-th order approximation by hidden Markov models, respectively. In the second approach, we employ the modified permutation partition of the set of words which considers equalities of symbols in addition to permutations of words. We show that the excess entropy and the transfer entropy rate of an ergodic SSP are equal to their modified permutation analogues, respectively.
Circular chemiresistors for microchemical sensors
Ho, Clifford K.
2007-03-13
A circular chemiresistor for use in microchemical sensors. A pair of electrodes is fabricated on an electrically insulating substrate. The pattern of electrodes is arranged in a circle-filling geometry, such as a concentric, dual-track spiral design, or a circular interdigitated design. A drop of a chemically sensitive polymer (i.e., chemiresistive ink) is deposited on the insulating substrate on the electrodes, which spreads out into a thin, circular disk contacting the pair of electrodes. This circularly-shaped electrode geometry maximizes the contact area between the pair of electrodes and the polymer deposit, which provides a lower and more stable baseline resistance than with linear-trace designs. The circularly-shaped electrode pattern also serves to minimize batch-to-batch variations in the baseline resistance due to non-uniform distributions of conductive particles in the chemiresistive polymer film.
DEFF Research Database (Denmark)
Andersen, Allan T.; Nielsen, Bo Friis
In this paper, we examine the implications of certain random permutations in an arrival process that have gained considerable interest in recent literature. The so-called internal and external shuffling have been used to explain phenomena observed in traffic traces from LANs. Loosely, the internal...... shuffling can be viewed as a way of performing local permutations in the arrival stream, while the external shuffling is a way of performing global permutations. We derive formulas for the correlation structures of the shuffled processes in terms of the original arrival process in great generality. The...
AUTHOR|(CDS)2108454; Zimmermann, Frank
2015-01-01
In response to a request from the 2013 Update of the European Strategy for Particle Physics, the global Future Circular Collider (FCC) study is preparing the foundation for a next-generation large-scale accelerator infrastructure in the heart of Europe. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh), to be accommodated in a new ∼100 km tunnel near Geneva. It also includes the design of a high-luminosity electron-positron collider (FCC-ee), which could be installed in the same tunnel as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb3Sn superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton collider. The interna...
AUTHOR|(CDS)2108454; Zimmermann, Frank
2015-01-01
In response to a request from the 2013 Update of the European Strategy for Particle Physics, the global Future Circular Collider (FCC) study is preparing the foundation for a next-generation large-scale accelerator infrastructure in the heart of Europe. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh), to be accommodated in a new ∼100 km tunnel near Geneva. It also includes the design of a high-luminosity electron-positron collider (FCC-ee), which could be installed in the same tunnel as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detector, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb3Sn superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton collider. The internat...
Towards Future Circular Colliders
AUTHOR|(CDS)2108454; Zimmermann, Frank
2015-01-01
The Large Hadron Collider (LHC) at CERN presently provides proton-proton collisions at a centre-of-mass (c.m.) energy of 13 TeV. The LHC design was started more than 30 years ago, and its physics programme will extend through the second half of the 2030’s. The global Future Circular Collider (FCC) study is now preparing for a post-LHC project. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh) in a new ∼100 km tunnel. It also includes the design of a high-luminosity electron-positron collider (FCC-ee) as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on $Nb_3Sn$ superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton c...
Circularly-Polarized Microstrip Antenna
Stanton, P. H.
1985-01-01
Microstrip construction compact for mobile applications. Circularly polarized microstrip antenna made of concentric cylindrical layers of conductive and dielectric materials. Coaxial cable feedlines connected to horizontal and vertical subelements from inside. Vertical subelement acts as ground for horizontal subelement.
Fine-grained permutation entropy as a measure of natural complexity for time series
Institute of Scientific and Technical Information of China (English)
Liu Xiao-Feng; Wang Yue
2009-01-01
In a recent paper [2002 Phys. Rev. Lett. 88 174102], Bandt and Pompe propose permutation entropy (PE)as a natural complexity measure for arbitrary time series which may be stationary or nonstationary, deterministic or stochastic. Their method is based on a comparison of neighbouring values. This paper further develops PE, and proposes the concept of fine-grained PE (FGPE) defined by the order pattern and magnitude of the difference between neighbouring values. This measure excludes the case where vectors with a distinct appearance are mistakenly mapped onto the same permutation type, and consequently FGPE becomes more sensitive to the dynamical change of time series than does PE, according to our simulation and experimental results.
Determining the parity of a permutation using an experimental NMR qutrit
International Nuclear Information System (INIS)
We present the NMR implementation of a recently proposed quantum algorithm to find the parity of a permutation. In the usual qubit model of quantum computation, it is widely believed that computational speedup requires the presence of entanglement and thus cannot be achieved by a single qubit. On the other hand, a qutrit is qualitatively more quantum than a qubit because of the existence of quantum contextuality and a single qutrit can be used for computing. We use the deuterium nucleus oriented in a liquid crystal as the experimental qutrit. This is the first experimental exploitation of a single qutrit to carry out a computational task. - Highlights: • NMR implementation of a quantum algorithm to determine the parity of a permutation. • Algorithm implemented on a single qutrit. • Computational speedup achieved without quantum entanglement. • Single qutrit shows quantum contextuality
Influence of the Talbot effect on the loss permutations of Fabry - Perot resonator modes
International Nuclear Information System (INIS)
The loss permutations of Fabry - Perot resonator modes caused by the harmonic spatial perturbation of the radiation phase on one of the mirrors are studied numerically. The periods and amplitudes of perturbations are found at which the second or third mode in the eigenvalue modulus becomes the first mode. It is shown that in the case of perturbations with the period l0, at which the Talbot length is equal to the double resonator length, the permutations are caused by an increase in the losses of the fundamental mode. It is also shown that the perturbation amplitudes with the period l0, which equalise losses of the modes, depend linearly on the inverse Fresnel number F-1. (resonators. modes)
Determining the parity of a permutation using an experimental NMR qutrit
Energy Technology Data Exchange (ETDEWEB)
Dogra, Shruti; Arvind,; Dorai, Kavita, E-mail: kavita@iisermohali.ac.in
2014-10-24
We present the NMR implementation of a recently proposed quantum algorithm to find the parity of a permutation. In the usual qubit model of quantum computation, it is widely believed that computational speedup requires the presence of entanglement and thus cannot be achieved by a single qubit. On the other hand, a qutrit is qualitatively more quantum than a qubit because of the existence of quantum contextuality and a single qutrit can be used for computing. We use the deuterium nucleus oriented in a liquid crystal as the experimental qutrit. This is the first experimental exploitation of a single qutrit to carry out a computational task. - Highlights: • NMR implementation of a quantum algorithm to determine the parity of a permutation. • Algorithm implemented on a single qutrit. • Computational speedup achieved without quantum entanglement. • Single qutrit shows quantum contextuality.
Fine-grained permutation entropy as a measure of natural complexity for time series
International Nuclear Information System (INIS)
In a recent paper [2002 Phys. Rev. Lett. 88 174102], Bandt and Pompe propose permutation entropy (PE) as a natural complexity measure for arbitrary time series which may be stationary or nonstationary, deterministic or stochastic. Their method is based on a comparison of neighbouring values. This paper further develops PE, and proposes the concept of fine-grained PE (FGPE) defined by the order pattern and magnitude of the difference between neighbouring values. This measure excludes the case where vectors with a distinct appearance are mistakenly mapped onto the same permutation type, and consequently FGPE becomes more sensitive to the dynamical change of time series than does PE, according to our simulation and experimental results. (general)
Power comparison between two multivariate permutation tests for matched-pairs designs
International Nuclear Information System (INIS)
A permutation maximal paired t-test (MPT) and permutation maximal parried signed rank test (MPSR) for testing problem in matched pairs designs are compared. A simulation study is conducted to estimate the power of these two tests for various parent populations. The effect of the dimension of the response variable on the power of these tests is studied. It has been observed that the power of these tests increases as the dimension of the response variable increases. In addition, the power of these two tests increases as the correlation between the components of the response variable decreases. It has also been noticed that when the underlying distribution is symmetric, the MPT test pro forms better than the MPSR test, while their performances are close when the distribution is skewed. (author). 18 refs., 12 figs., 5 tabs
Electron-muon permutation symmetry and multiplicatively conserved lepton number in gauge theories
International Nuclear Information System (INIS)
The similarity between the weak interactions of electron and muon is extended to the principle that all e and μ interactions in gauge models are invariant under e reversible μ exchange. This necessitates the existence of two Higgs doublets phisub(e) and phisub(μ), and an extended e reversible μ permutation invariance. After symmetry-breaking, a multiplicatively conserved 'permutation parity' π = +-1 for all particles naturally emerges, with πsub(μ) = -πsub(e) = 1. The model forbids μ→eγ but predicts e-e-→μ-μ- mediated by π = -1 Higgs bosons at approximately 10-11 times the rate of typical weak cross sections. (Auth.)
Directory of Open Access Journals (Sweden)
Li-bo Zhang
2015-01-01
Full Text Available This paper presents a solution to satisfy the increasing requirements for secure medical image transmission and storage over public networks. The proposed scheme can simultaneously encrypt and compress the medical image using compressive sensing (CS and pixel swapping based permutation approach. In the CS phase, the plain image is compressed and encrypted by chaos-based Bernoulli measurement matrix, which is generated under the control of the introduced Chebyshev map. The quantized measurements are then encrypted by permutation-diffusion type chaotic cipher for the second level protection. Simulations and extensive security analyses have been performed. The results demonstrate that at a large scale of compression ratio the proposed cryptosystem can provide satisfactory security level and reconstruction quality.
International Nuclear Information System (INIS)
It is well known that the flow-shop scheduling problem (FSSP) is a branch of production scheduling and is NP-hard. Now, many different approaches have been applied for permutation flow-shop scheduling to minimize makespan, but current algorithms even for moderate size problems cannot be solved to guarantee optimality. Some literatures searching PSO for continuous optimization problems are reported, but papers searching PSO for discrete scheduling problems are few. In this paper, according to the discrete characteristic of FSSP, a novel particle swarm optimization (NPSO) algorithm is presented and successfully applied to permutation flow-shop scheduling to minimize makespan. Computation experiments of seven representative instances (Taillard) based on practical data were made, and comparing the NPSO with standard GA, we obtain that the NPSO is clearly more efficacious than standard GA for FSSP to minimize makespan
Accidental permutation symmetries as a test for Grand Unification: the supersymmetric $SU(5)$ case
Fichet, Sylvain
2016-01-01
Unification of matter fields implies the existence of accidental permutation symmetries, which potentially remain immune to large quantum corrections up to the TeV scale. We investigate the case of a supersymmetric $SU(5)$ grand unified theory, where such a permutation symmetry is present in the up-type squark sector. We present a variety of tests allowing to challenge the $SU(5)$ hypothesis based on the observation of squarks at the LHC. These tests appear as relations among observables involving flavour-violating or chirality-flipping decays of squarks. Moreover, they rely on top-polarimetry and charm-tagging. As an example, we discuss the application to the scenario of Natural Supersymmetry, while more examples can be found in the related journal publications.
Weck, Peter J; Brown, Michael R; Wicks, Robert T
2014-01-01
The Bandt-Pompe permutation entropy and the Jensen-Shannon statistical complexity are used to analyze fluctuating time series of three different plasmas: the magnetohydrodynamic (MHD) turbulence in the plasma wind tunnel of the Swarthmore Spheromak Experiment (SSX), drift-wave turbulence of ion saturation current fluctuations in the edge of the Large Plasma Device (LAPD) and fully-developed turbulent magnetic fluctuations of the solar wind taken from the WIND spacecraft. The entropy and complexity values are presented as coordinates on the CH plane for comparison among the different plasma environments and other fluctuation models. The solar wind is found to have the highest permutation entropy and lowest statistical complexity of the three data sets analyzed. Both laboratory data sets have larger values of statistical complexity, suggesting these systems have fewer degrees of freedom in their fluctuations, with SSX magnetic fluctuations having slightly less complexity than the LAPD edge fluctuations. The CH ...
Data Hiding by LSB Substitution Using Genetic Optimal Key-Permutation
Directory of Open Access Journals (Sweden)
Marghny Mohamed
2011-01-01
Full Text Available The least significant bit (LSB embedding method is one of the most commonly used techniques; it targets the LSB'sof the host image to hide the data. This paper deals with three main steganography challenges (i.e. capacity, imperceptibility,and security. This is achieved by hybrid data hiding scheme incorporates LSB technique with a key-permutation method. Thepaper also proposes an optimal key permutation method using genetic algorithms for best key selection. Both normal andoptimized methods are tested with standard images, varying both data size as well as key space. Final experimental resultsshow decrement in computation time when increasing number of keys, at the same time system security improves.
Circular dichroism readout of sugar recognition in the cleft of a fused-pyridine receptor
Tamaru, Shun-ichi; Shinkai, Seiji; Khasanov, Alisher B.; Bell, Thomas W.
2002-01-01
Dicarboxamide host 2 forms 1:1 complexes with n-octyl pyranosides derived from d-glucose, d-mannose, d-galactose, d-fucose, d-lyxose, and d-arabinose. Association constants (Ka) in the range of 77–940 M−1 were measured in chloroform by means of induced circular dichroism and fluorescence spectroscopy. Variations in Ka values correspond qualitatively to expected differences in hydrogen-bonding abilities of guest hydroxyl groups. Induced circular dichroism effects for...
Coloring fuzzy circular interval graphs
Eisenbrand, Friedrich; Niemeier, Martin
2012-01-01
Computing the weighted coloring number of graphs is a classical topic in combinatorics and graph theory. Recently these problems have again attracted a lot of attention for the class of quasi-line graphs and more specifically fuzzy circular interval graphs. The problem is NP-complete for quasi-line graphs. For the subclass of fuzzy circular interval graphs however, one can compute the weighted coloring number in polynomial time using recent results of Chudnovsky and Ovetsky and of King and Re...
Energy dissipation in circular tube
A.D. Girgidov
2012-01-01
Energy dissipation distribution along the circular tube radius is important in solving such problems as calculation of heat transfer by the air flow through building envelope; calculation of pressure loss in spiral flows; calculation of cyclones with axial and tangential supply of dust-containing gas.Two types of one-dimensional radially axisymmetric flows in circular tube were considered: axial flow and rotation about the axis (Rankine vortex). Relying on two- and four-layer description of a...
A Modern Advanced Hill Cipher Involving a Permuted Key and Modular Arithmetic Addition Operation
Directory of Open Access Journals (Sweden)
V.U.K. Sastry
2011-05-01
Full Text Available In this paper we have devoted our attention to the study of a block cipher by generalizing advanced Hill cipher by including a permuted key. In this analysis we find that the iteration process, the mix operation and the modular arithmetic operation involved in the cipher mixes the binary bits of the key and the plaintext in a thorough manner. The avalanche effect and the cryptanalysis markedly indicate that the cipher is a strong one.
Fermion mass matrix, CP violation and rare decays in permutation symmetry
International Nuclear Information System (INIS)
Motivation and full implications of a model, for fermion mass matrix, based on permutation symmetry S4, are summarized. In addition to predictions msub(t) and K-M mixing angles, /epsilon'/epsilon/, electric dipole moments, mixing and asymmetry in D0, B0 and Bsub(s)sup(0) and branching ratios for rare decay modes are given. Neutrino mass pattern and mixings are predicted
International Nuclear Information System (INIS)
We use the permutation symmetry between the product of several group manifolds in combination with orbifolds and T-duality to construct new classes of symmetry breaking branes on products of group manifolds. The resulting branes mix the submanifolds and break part of the diagonal chiral algebra of the theory. We perform a Langrangian analysis as well as a boundary CFT construction of these branes and find agreement between the two methods
Li-bo Zhang; Zhi-liang Zhu; Ben-qiang Yang; Wen-yuan Liu; Hong-feng Zhu; Ming-yu Zou
2015-01-01
This paper presents a solution to satisfy the increasing requirements for secure medical image transmission and storage over public networks. The proposed scheme can simultaneously encrypt and compress the medical image using compressive sensing (CS) and pixel swapping based permutation approach. In the CS phase, the plain image is compressed and encrypted by chaos-based Bernoulli measurement matrix, which is generated under the control of the introduced Chebyshev map. The quantized measureme...
X-s-Permutable Subgroups%X-s-置换子群
Institute of Scientific and Technical Information of China (English)
石磊; 郭文彬; 易小兰
2008-01-01
Let X be a nonempty subset of a group G.A subgroup H of G is said to be X-spermutable in G if,for every Sylow subgroup T of G,there exists an element x ∈X such that HTx=Tx H.In this paper,we obtain some results about the X-s-permutable subgroups and use them to determine the structure of some finite groups.
A Highly Nonlinear Differentially 4 Uniform Power Mapping That Permutes Fields of Even Degree
Bracken, Carl; Leander, Gregor
2009-01-01
Functions with low differential uniformity can be used as the s-boxes of symmetric cryptosystems as they have good resistance to differential attacks. The AES (Advanced Encryption Standard) uses a differentially- 4 uniform function called the inverse function. Any function used in a symmetric cryptosystem should be a permutation. Also, it is required that the function is highly nonlinear so that it is resistant to Matsui’s linear attack. In this article we demonstrate that t...
Construction Zero Cross Correlation Code using Permutation Matrix for SAC-OCDMA Systems
Nisar, K. S.
2016-01-01
This paper present a new method for constructing zero cross correlation code with the help of permutation matrices. The benefits of this newly proposed code are easy way code construction, the code weight exist for every natural number and the code length is acceptable. The numerical comparison shows that the proposed code has better or compatible code length compared with other existing zero cross correlation code in Optical Spectrum Code Division Multiple Access (OSCDMA) systems.
Flavour symmetry as a Spontaneously Broken Discrete Permutation Symmetry Embedded in Colour
Törnqvist, N A
1999-01-01
A new mechanism for breaking an internal symmetry spontaneously is discussed, which is intermediate between the Nambu-Goldstone and Wigner modes of symmetry breaking. Here the quark-antiquark sea takes the role of the vacuum of the Nambu-Goldstone case. Flavour symmetry becomes a discrete permutation symmetry of the valence quarks with respect to the sea quarks, which can be spontaneously broken without generation of massless Goldstone bosons.
A Cell-Based Protein-Protein Interaction Method Using a Permuted Luciferase Reporter
Eishingdrelo, Haifeng; Cai, Jidong; Weissensee, Paul; Sharma, Praveen; Tocci, Michael J; Wright, Paul S
2011-01-01
We have developed a novel cell-based protein-protein interaction assay method. The method relies on conversion of an inactive permuted luciferase containing a Tobacco Etch Virus protease (TEV) cleavage sequence fused onto protein (A) to an active luciferase upon interaction and cleavage by another protein (B) fused with the TEV protease. We demonstrate assay applicability for ligand-induced protein-protein interactions including G-protein coupled receptors, receptor tyrosine kinases and nucle...
Li-Ye Zhao; Lei Wang; Ru-Qiang Yan
2015-01-01
This paper presents a rolling bearing fault diagnosis approach by integrating wavelet packet decomposition (WPD) with multi-scale permutation entropy (MPE). The approach uses MPE values of the sub-frequency band signals to identify faults appearing in rolling bearings. Specifically, vibration signals measured from a rolling bearing test system with different defect conditions are decomposed into a set of sub-frequency band signals by means of the WPD method. Then, each sub-frequency band sign...
Bearing Fault Diagnosis Based on Multiscale Permutation Entropy and Support Vector Machine
Jian-Jiun Ding; Chun-Chieh Wang; Chiu-Wen Wu; Po-Hung Wu; Shuen-De Wu
2012-01-01
Bearing fault diagnosis has attracted significant attention over the past few decades. It consists of two major parts: vibration signal feature extraction and condition classification for the extracted features. In this paper, multiscale permutation entropy (MPE) was introduced for feature extraction from faulty bearing vibration signals. After extracting feature vectors by MPE, the support vector machine (SVM) was applied to automate the fault diagnosis procedure. Simulation results demonstr...
Permutation codes for the state assignment of fault tolerant sequential machines
Chen, M.; Trachtenberg, E. A.
1991-01-01
A new fault-tolerant state assignment method is suggested for synchronous sequential machines. It is assumed that the inputs are fault free and that for no input it is possible to reach all or most of the states, whose number may be fairly large. Error correcting codes for the state assignment are generated by permutations of a chosen linear code. A state assignment algorithm is developed and its computational complexity is estimated. Examples are given.
On $2$-star-permutability in regular multi-pointed categories
Gran, Marino; Rodelo, Diana
2014-01-01
$2$-star-permutable categories were introduced in a joint work with Z. Janelidze and A. Ursini as a common generalisation of regular Mal'tsev categories and of normal subtractive categories. In the present article we first characterise these categories in terms of what we call star-regular pushouts. We then show that the $3 \\times 3$ Lemma characterising normal subtractive categories and the Cuboid Lemma characterising regular Mal'tsev categories are special instances of a more general homolo...
Permutation invariant algebras, a Fock space realization and the Calogero model
International Nuclear Information System (INIS)
We study permutation invariant oscillator algebras and their Fock space representations using three equivalent techniques, i.e. (i) a normally ordered expansion in creation and annihilation operators, (ii) the action of annihilation operators on monomial states in Fock space and (iii) Gram matrices of inner products in Fock space. We separately discuss permutation invariant algebras which possess hermitean number operators and permutation invariant algebras which possess non-hermitean number operators. The results of a general analysis are applied to the SM-extended Heisenberg algebra, underlying the M-body Calogero model. Particular attention is devoted to the analysis of Gram matrices for the Calogero model. We discuss their structure, eigenvalues and eigenstates. We obtain a general condition for positivity of eigenvalues, meaning that all norms of states in Fock space are positive if this condition is satisfied. We find a universal critical point at which the reduction of the physical degrees of freedom occurs. We construct dual operators, leading to the ordinary Heisenberg algebra of free Bose oscillators. From the Fock-space point of view, we briefly discuss the existence of a mapping from the Calogero oscillators to the free Bose oscillators and vice versa. (orig.)
Entanglement cost and entangling power of bipartite unitary and permutation operators
Chen, Lin; Yu, Li
2016-04-01
It is known that any bipartite unitary operator of Schmidt rank 3 is equivalent to a controlled unitary under local unitaries. We propose a standard form of such operators. Using the form we improve the upper bound for the entanglement cost to implement such operators under local operations and classical communications (LOCC), and provide a corresponding protocol. A part of our protocol is based on a recursive-control protocol which is helpful for implementing other unitary operators. We show that any bipartite permutation unitary of Schmidt rank 3 can be implemented using LOCC and two ebits. We give two protocols for implementing bipartite permutation unitaries of any Schmidt rank r and showed that one of the protocol uses O (r ) ebits of entanglement and O (r ) bits of classical communication, while these two types of costs for the other protocol scale as O (r logr ) but the actual values are smaller for all r permutation unitaries of Schmidt ranks 2 and 3. We show that they are respectively 1 ebit and some value between log29 -16 /9 and log23 ebits.
Hippocampal activation during face-name associative memory encoding: blocked versus permuted design
International Nuclear Information System (INIS)
The contribution of the hippocampal subregions to episodic memory through the formation of new associations between previously unrelated items such as faces and names is established but remains under discussion. Block design studies in this area of research generally tend to show posterior hippocampal activation during encoding of novel associational material while event-related studies emphasize anterior hippocampal involvement. We used functional magnetic resonance imaging to assess the involvement of anterior and posterior hippocampus in the encoding of novel associational material compared to the viewing of previously seen associational material. We used two different experimental designs, a block design and a permuted block design, and applied it to the same associative memory task to perform valid statistical comparisons. Our results indicate that the permuted design was able to capture more anterior hippocampal activation compared to the block design, which emphasized more posterior hippocampal involvement. These differences were further investigated and attributed to a combination of the polymodal stimuli we used and the experimental design. Activation patterns during encoding in both designs occurred along the entire longitudinal axis of the hippocampus, but with different centers of gravity. The maximal activated voxel in the block design was situated in the posterior half of the hippocampus while in the permuted design this was located in the anterior half. (orig.)
Hippocampal activation during face-name associative memory encoding: blocked versus permuted design
Energy Technology Data Exchange (ETDEWEB)
De Vogelaere, Frederick; Vingerhoets, Guy [Ghent University, Laboratory for Neuropsychology, Department of Neurology, Ghent (Belgium); Santens, Patrick; Boon, Paul [Ghent University Hospital, Department of Neurology, Ghent (Belgium); Achten, Erik [Ghent University Hospital, Department of Radiology, Ghent (Belgium)
2010-01-15
The contribution of the hippocampal subregions to episodic memory through the formation of new associations between previously unrelated items such as faces and names is established but remains under discussion. Block design studies in this area of research generally tend to show posterior hippocampal activation during encoding of novel associational material while event-related studies emphasize anterior hippocampal involvement. We used functional magnetic resonance imaging to assess the involvement of anterior and posterior hippocampus in the encoding of novel associational material compared to the viewing of previously seen associational material. We used two different experimental designs, a block design and a permuted block design, and applied it to the same associative memory task to perform valid statistical comparisons. Our results indicate that the permuted design was able to capture more anterior hippocampal activation compared to the block design, which emphasized more posterior hippocampal involvement. These differences were further investigated and attributed to a combination of the polymodal stimuli we used and the experimental design. Activation patterns during encoding in both designs occurred along the entire longitudinal axis of the hippocampus, but with different centers of gravity. The maximal activated voxel in the block design was situated in the posterior half of the hippocampus while in the permuted design this was located in the anterior half. (orig.)
Ram, Sumit Kumar; Molinas, Marta
2016-01-01
This article presents the applicability of Permutation Entropy based complexity measure of a time series for detection of fault in wind turbines. A set of electrical data from one faulty and one healthy wind turbine were analysed using traditional FastFourier analysis in addition to Permutation Entropy analysis to compare the complexity index of phase currents of the two turbines over time. The 4 seconds length data set did not reveal any low frequency in the spectra of currents, neither did they show any meaningful differences of spectrum between the two turbine currents. Permutation Entropy analysis of the current waveforms of same phases for the two turbines are found to have different complexity values over time, one of them being clearly higher than the other. The work of Yan et. al. in has found that higher entropy values related to thepresence of failure in rotary machines in his study. Following this track, further efforts will be put into relating the entropy difference found in our study to possible...
Revisiting the European sovereign bonds with a permutation-information-theory approach
Fernández Bariviera, Aurelio; Zunino, Luciano; Guercio, María Belén; Martinez, Lisana B.; Rosso, Osvaldo A.
2013-12-01
In this paper we study the evolution of the informational efficiency in its weak form for seventeen European sovereign bonds time series. We aim to assess the impact of two specific economic situations in the hypothetical random behavior of these time series: the establishment of a common currency and a wide and deep financial crisis. In order to evaluate the informational efficiency we use permutation quantifiers derived from information theory. Specifically, time series are ranked according to two metrics that measure the intrinsic structure of their correlations: permutation entropy and permutation statistical complexity. These measures provide the rectangular coordinates of the complexity-entropy causality plane; the planar location of the time series in this representation space reveals the degree of informational efficiency. According to our results, the currency union contributed to homogenize the stochastic characteristics of the time series and produced synchronization in the random behavior of them. Additionally, the 2008 financial crisis uncovered differences within the apparently homogeneous European sovereign markets and revealed country-specific characteristics that were partially hidden during the monetary union heyday.
Directory of Open Access Journals (Sweden)
Nadia Mammone
2015-07-01
Full Text Available Permutation entropy (PE has been widely exploited to measure the complexity of the electroencephalogram (EEG, especially when complexity is linked to diagnostic information embedded in the EEG. Recently, the authors proposed a spatial-temporal analysis of the EEG recordings of absence epilepsy patients based on PE. The goal here is to improve the ability of PE in discriminating interictal states from ictal states in absence seizure EEG. For this purpose, a parametrical definition of permutation entropy is introduced here in the field of epileptic EEG analysis: the permutation Rényi entropy (PEr. PEr has been extensively tested against PE by tuning the involved parameters (order, delay time and alpha. The achieved results demonstrate that PEr outperforms PE, as there is a statistically-significant, wider gap between the PEr levels during the interictal states and PEr levels observed in the ictal states compared to PE. PEr also outperformed PE as the input to a classifier aimed at discriminating interictal from ictal states.
Resch-Genger, U.; Hoffmann, K.; Nietfeld, W; A. Engel; Neukammer, J.; Nitschke, R.; Ebert, P.; Macdonald, R
2005-01-01
The scope of this paper is to illustrate the need for an improved quality assurance in fluorometry. For this purpose, instrumental sources of error and their influences on the reliability and comparability of fluorescence data are highlighted for frequently used photoluminescence techniques ranging from conventional macro- and microfluorometry over fluorescence microscopy and flow cytometry to microarray technology as well as in vivo fluorescence imaging. Particularly, the need for and requir...
Circularly polarized open-loop antenna
Li, Rong-Lin; Fusco, Vincent F.; Nakano, Hisamatsu
2003-01-01
A printed circular open-loop antenna is introduced as a simple structure for producing circular polarization; the antenna is fed with a coaxial probe. By introducing a gap within the circular loop a traveling-wave current is excited and thus circularly polarized radiation can be achieved. An optimized circularly polarized antenna is designed through numerical analysis using a so-called parametric method of moment technique. Experimental verification of the new antenna is presented. The antenn...
Claw-free circular-perfect graphs
Pecher, Arnaud; Zhu, Xuding
2007-01-01
The circular chromatic number of a graph is a well studied refinement of the chromatic number. Circular perfect graphs is a superclass of perfect graphs defined by means of this more general coloring concept. This paper studies claw free circular perfect graphs. A consequence of the strong perfect graph theorem is that minimal circular perfect graphs G. In contrast to this result, it is shown in that minimal circular imperfect graphs G can have arbitrarily large independence number and arbitr...
Ito, Genta
2008-01-01
Permutations of particle labels are usually used to illustrate the relationship between classical and quantum statistics. We use permutations of attributes/properties of particles to express properties of waves. We express events of the well-known two-double-slit experiment (in regimes that are appropriate to quantum interference and classical interference) in terms of symmetries of permutations of particle labels and attributes. We also obtain a new system called residual interference, and s...
Hu, Yuwei; Ren, Jiangtao; Lu, Chun-Hua; Willner, Itamar
2016-07-13
The switchable pH-driven reversible assembly and dissociation of interlocked circular DNA dimers is presented. The circular DNA dimers are interconnected by pH-responsive nucleic acid bridges. In one configuration, the two-ring nanostructure is separated at pH = 5.0 to individual rings by reconfiguring the interlocking bridges into C-G·C(+) triplex units, and the two-ring assembly is reformed at pH = 7.0. In the second configuration, the dimer of circular DNAs is bridged at pH = 7.0 by the T-A·T triplex bridging units that are separated at pH = 10.0, leading to the dissociation of the dimer to single circular DNA nanostructures. The two circular DNA units are also interconnected by two pH-responsive locks. The pH-programmed opening of the locks at pH = 5.0 or pH = 10.0 yields two isomeric dimer structures composed of two circular DNAs. The switchable reconfigured states of the circular DNA nanostructures are followed by time-dependent fluorescence changes of fluorophore/quencher labeled systems and by complementary gel electrophoresis experiments. The dimer circular DNA structures are further implemented as scaffolds for the assembly of Au nanoparticle dimers exhibiting controlled spatial separation. PMID:27225955
Podokinetic circular vection: characteristics and interaction with optokinetic circular vection.
Becker, W; Kliegl, K; Kassubek, J; Jürgens, R
2016-07-01
Stabilising horizontal body orientation in space without sight on a rotating platform by holding to a stationary structure and circular 'treadmill' stepping in the opposite direction can elicit an illusion of self-turning in space (Bles and Kapteyn in Agressologie 18:325-328, 1977). Because this illusion is analogous to the well-known illusion of optokinetic circular vection (oCV), we call it 'podokinetic circular vection' (pCV) here. Previous studies using eccentric stepping on a path tangential to the rotation found that pCV was always contraversive relative to platform rotation. In contrast, when our subjects stepped at the centre of rotation about their vertical axis, we observed an inverted, ipsiversive pCV as a reproducible trait in many of our subjects. This ipCV occurred at the same latency as the pCV of subjects reporting the actually expected contraversive direction, but had lower gain. In contrast to pCV, the nystagmus accompanying circular treadmill stepping had the same direction in all individuals (slow phase in the direction of platform motion). The direction of an individual's pCV predicted the characteristics of the CV resulting from combined opto- and podokinetic stimulation (circular treadmill stepping while viewing a pattern rotating together with the platform): in individuals with contraversive pCV, latency shortened and both gain and felt naturalness increased in comparison with pure oCV, whereas the opposite (longer latency, reduced gain and naturalness) occurred in individuals with ipCV. Taken together, the reproducibility of ipCV, the constant direction of nystagmus and the fact that pCV direction predicts the outcome of combined stimulation suggest that ipCV is an individual trait of many subjects during compensatory stepping at the centre of rotation. A hypothetical model is presented of how ipCV possibly could arise. PMID:26965438
Circular RNA expands its territory.
Bao, Chunyang; Lyu, Dongbin; Huang, Shenglin
2016-03-01
Circular RNAs (circRNAs) represent a novel class of widespread non-coding RNAs in eukaryotes. They are unusually stable RNA molecules with cell type-specific expression patterns, and are predominantly present in the cytoplasm. We recently demonstrated the existence of abundant circRNAs in exosomes and suggest a potential application of exosomal circRNAs for cancer detection. PMID:27308606
High intensity circular proton accelerators
International Nuclear Information System (INIS)
Circular machines suitable for the acceleration of high intensity proton beams include cyclotrons, FFAG accelerators, and strong-focusing synchrotrons. This paper discusses considerations affecting the design of such machines for high intensity, especially space charge effects and the role of beam brightness in multistage accelerators. Current plans for building a new generation of high intensity 'kaon factories' are reviewed. 47 refs
Circular polarization observed in bioluminescence
Wijnberg, Hans; Meijer, E.W.; Hummelen, J.C.; Dekkers, H.P.J.M.; Schippers, P.H.; Carlson, A.D.
1980-01-01
While investigating circular polarization in luminescence, and having found it in chemiluminescence, we have studied bioluminescence because it is such a widespread and dramatic natural phenomenon. We report here that left and right lanterns of live larvae of the fireflies, Photuris lucicrescens and
Application of circular filter inserts
International Nuclear Information System (INIS)
High efficiency particulate air (HEPA) filters are used in the ventilation of nuclear plant as passive clean-up devices. Traditionally, the work-horse of the industry has been the rectangular HEPA filter. An assessment of the problems associated with remote handling, changing, and disposal of these rectangular filters suggested that significant advantages to filtration systems could be obtained by the adoption of HEPA filters with circular geometry for both new and existing ventilation plants. This paper covers the development of circular geometry filters and highlights the advantages of this design over their rectangular counterparts. The work has resulted in a range of commercially available filters for flows from 45 m3/h up to 3400 m3/h. This paper also covers the development of a range of sizes and types of housings that employ simple change techniques which take advantage of the circular geometry. The systems considered here have been designed in response to the requirements for shielded (remote filter change) and for unshielded facilities (potentially for bag changing of filters). Additionally the designs have allowed for the possibility of retrofitting circular geometry HEPA filters in place of the rectangular geometry filter
Permutation Min-Entropy and Statistical Complexity Analysis of Electricity Spot Price
Fan, Qingju; Li, Dan
2015-10-01
In this study, we investigate the subtle temporal dynamics of California 1999-2000 spot price series based on permutation min-entropy (PME) and complexity-entropy causality plane. The dynamical transitions of price series are captured and the temporal correlations of price series are also discriminated by the recently introduced PME. Moreover, utilizing the CECP, we provide a refined classification of the monthly price dynamics and obtain an insight into the stochastic nature of price series. The results uncover that the spot price signal presents diverse temporal correlations and exhibits a higher stochastic behavior during the periods of crisis.
A k-permutation algorithm for Fixed Satellite Service orbital allotments
Reilly, Charles H.; Mount-Campbell, Clark A.; Gonsalvez, David J. A.
1988-01-01
A satellite system synthesis problem, the satellite location problem (SLP), is addressed in this paper. In SLP, orbital locations (longitudes) are allotted to geostationary satellites in the Fixed Satellite Service. A linear mixed-integer programming model is presented that views SLP as a combination of two problems: (1) the problem of ordering the satellites and (2) the problem of locating the satellites given some ordering. A special-purpose heuristic procedure, a k-permutation algorithm, that has been developed to find solutions to SLPs formulated in the manner suggested is described. Solutions to small example problems are presented and analyzed.
Three-pion states and a new approach to the permutation group S3. I
International Nuclear Information System (INIS)
A new method is developed for picking a given irreducible representation of the permutation group S3 out of the product of many representations. It is then used to construct three-pion wave functions of arbitrary spin and parity. Applications of the method to three-fermion systems are briefly described. The essence of the method is to represent the two-dimensional representation of S3 as a ''complex number'' in an Argand diagram; because the action of S3 involves simple rotations and reflections in the diagram, the behavior of products of many two-dimensional representations is easy to analyze
Finding fixed satellite service orbital allotments with a k-permutation algorithm
Reilly, Charles H.; Mount-Campbell, Clark A.; Gonsalvez, David J. A.
1990-01-01
A satellite system synthesis problem, the satellite location problem (SLP), is addressed. In SLP, orbital locations (longitudes) are allotted to geostationary satellites in the fixed satellite service. A linear mixed-integer programming model is presented that views SLP as a combination of two problems: the problem of ordering the satellites and the problem of locating the satellites given some ordering. A special-purpose heuristic procedure, a k-permutation algorithm, has been developed to find solutions to SLPs. Solutions to small sample problems are presented and analyzed on the basis of calculated interferences.
Generalized permutation symmetry and the flavour problem in SU(2)sub(L)xU(1)
International Nuclear Information System (INIS)
A generalized permutation group is introduced as a possible horizontal symmetry for SU(2)sub(L)xU(1) gauge theories. It leads to the unique two generation quark mass matrices with a correct prediction for the Cabibbo angle. For three generations the model exhibits spontaneous CP violation, correlates the Kobayashi-Maskawa mixing parameters s1 and s3 and predicts an upper bound for the running top quark mass of approximately 45 GeV. The hierarchy of generations is due to a hierarchy of vacuum expectation values rather than of Yukawa coupling constants. (orig.)
CP nonconservation and rare processes in an S4 model of permutation symmetry
International Nuclear Information System (INIS)
Further implications of a model based on permutation symmetry, that predicts 25 GeV<= msub(t)<=35 GeV and mixing angles consistent with tausub(B), are worked out in detail. The model is shown to be of the superweak type as far as CP violation is concerned, with delta=0 and CP violation arising through flavor-changing Higgs exchange. We calculate CP and mixing parameters for K, D, B and Bsub(s) systems; the electric dipole moments of different quarks and leptons; and rates for rare decays. (orig.)
International Nuclear Information System (INIS)
The permutation entropy concept of Bandt and Pompe (2002 Phys. Rev. Lett. 88 174102) is used to analyze the fluctuations in ion saturation current that spontaneously arise in a basic experimental study (Pace et al 2008 Phys. Plasmas 15 122304) of electron heat transport in a magnetized plasma. From the behavior of the Shannon entropy and the Jensen–Shannon complexity it is found that the underlying dynamics are chaotic rather than stochastic. A partitioning and scrambling technique is used to demonstrate that the exponential character of the associated power spectrum arises from individual Lorentzian pulses observed in the time series. (paper)
Permutation-type solutions to the Yang-Baxter and other n-simplex equations
Hietarinta, Jarmo
1997-01-01
We study permutation type solutions to n-simplex equations, that is, solutions whose R matrix can be written as a product of delta- functions depending linearly on the indices. With this ansatz the D^{n(n+1)} equations of the n-simplex equation reduce to an [n(n+1)/2+1]x[n(n+1)/2+1] matrix equation over Z_D. We have completely analyzed the 2-, 3- and 4-simplex equations in the generic D case. The solutions show interesting patterns that seem to continue to still higher simplex equations.
Cryptanalysis of a one round chaos-based Substitution Permutation Network
Arroyo, David; Rodriguez, F B
2012-01-01
The interleaving of chaos and cryptography has been the aim of a large set of works since the beginning of the nineties. Many encryption proposals have been introduced to improve conventional cryptography. However, many proposals possess serious problems according to the basic requirements for the secure exchange of information. In this paper we highlight some of the main problems of chaotic cryptography by means of the analysis of a very recent chaotic cryptosystem based on a one round Substitution Permutation Network. More specifically, we show that it is not possible to avoid the security problems of that encryption architecture just by including a chaotic system as core of the derived encryption system.
Projective ribbon permutation statistics: A remnant of non-Abelian braiding in higher dimensions
Freedman, Michael; Hastings, Matthew B.; Nayak, Chetan; Qi, Xiao-Liang; Walker, Kevin; Wang, Zhenghan
2011-03-01
In a recent paper, Teo and Kane [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.104.046401 104, 046401 (2010)] proposed a three-dimensional (3D) model in which the defects support Majorana fermion zero modes. They argued that exchanging and twisting these defects would implement a set R of unitary transformations on the zero-mode Hilbert space which is a “ghostly” recollection of the action of the braid group on Ising anyons in two dimensions. In this paper, we find the group T2n, which governs the statistics of these defects by analyzing the topology of the space K2n of configurations of 2n defects in a slowly spatially varying gapped free-fermion Hamiltonian: T2n≡π1(K2n). We find that the group T2n=Z×T2nr, where the “ribbon permutation group” T2nr is a mild enhancement of the permutation group S2n: T2nr≡Z2×E((Z2)2n⋊S2n). Here, E((Z2)2n⋊S2n) is the “even part” of (Z2)2n⋊S2n, namely, those elements for which the total parity of the element in (Z2)2n added to the parity of the permutation is even. Surprisingly, R is only a projective representation of T2n, a possibility proposed by Wilczek [e-print arXiv:hep-th/9806228]. Thus, Teo and Kane’s defects realize projective ribbon permutation statistics,” which we show to be consistent with locality. We extend this phenomenon to other dimensions, codimensions, and symmetry classes. We note that our analysis applies to 3D networks of quantum wires supporting Majorana fermions; thus, these networks are not required to be planar. Because it is an essential input for our calculation, we review the topological classification of gapped free-fermion systems and its relation to Bott periodicity.
Wilson, S.
1977-01-01
A method is presented for the determination of the representation matrices of the spin permutation group (symmetric group), a detailed knowledge of these matrices being required in the study of the electronic structure of atoms and molecules. The method is characterized by the use of two different coupling schemes. Unlike the Yamanouchi spin algebraic scheme, the method is not recursive. The matrices for the fundamental transpositions can be written down directly in one of the two bases. The method results in a computationally significant reduction in the number of matrix elements that have to be stored when compared with, say, the standard Young tableaux group theoretical approach.
Multistage Off-Line Permutation Packet Routing on a Mesh: An Approach with Elementary Mathematics
Institute of Scientific and Technical Information of China (English)
Kevin Chiew; Yingjiu Li
2009-01-01
Various methods have been proposed for off-line permutation packet routing on a mesh. One of the methods is known as multistage routing, in which the first stage is crucial. For the first stage of routing, the previous study normally converts it to a problem of graph theory and proves the existence of solutions. However, there is a lack of simple algorithms to the first stage of routing. This article presents an explicit and simple approach for the first stage of routing based on elementary mathematics.
Adaptive Tests of Significance Using Permutations of Residuals with R and SAS
O'Gorman, Thomas W
2012-01-01
Provides the tools needed to successfully perform adaptive tests across a broad range of datasets Adaptive Tests of Significance Using Permutations of Residuals with R and SAS illustrates the power of adaptive tests and showcases their ability to adjust the testing method to suit a particular set of data. The book utilizes state-of-the-art software to demonstrate the practicality and benefits for data analysis in various fields of study. Beginning with an introduction, the book moves on to explore the underlying concepts of adaptive tests, including:Smoothing methods and normalizing transforma
Self-embeddings of Hamming Steiner triple systems of small order and APN permutations
Rifà i Coma, Josep; Solov'eva, Faina I.; Villanueva, M.
2015-01-01
The classification, up to isomorphism, of all self-embedding monomial power permutations of Hamming Steiner triple systems of order n = 2 m − 1 for small m (m ≤ 22), is given. As far as we know, for m ∈ {5, 7, 11, 13, 17, 19}, all given self-embeddings in closed surfaces are new. Moreover, they are cyclic for all m and nonorientable at least for all m ≤ 19. For any non prime m, the nonexistence of such self-embeddings in a closed surface is proven. The rotation line spectrum for self-embeddin...
Epstein, Richard I.; Edwards, Bradley C.; Buchwald, Melvin I.; Gosnell, Timothy R.
1995-01-01
Fluorescent refrigeration is based on selective radiative pumping, using substantially monochromatic radiation, of quantum excitations which are then endothermically redistributed to higher energies. Ultimately, the populated energy levels radiatively deexcite emitting, on the average, more radiant energy than was initially absorbed. The material utilized to accomplish the cooling must have dimensions such that the exciting radiation is strongly absorbed, but the fluorescence may exit the material through a significantly smaller optical pathlength. Optical fibers and mirrored glasses and crystals provide this requirement.
Directory of Open Access Journals (Sweden)
Nader Ghaffari-Nasab
2010-07-01
Full Text Available During the past two decades, there have been increasing interests on permutation flow shop with different types of objective functions such as minimizing the makespan, the weighted mean flow-time etc. The permutation flow shop is formulated as a mixed integer programming and it is classified as NP-Hard problem. Therefore, a direct solution is not available and meta-heuristic approaches need to be used to find the near-optimal solutions. In this paper, we present a new discrete firefly meta-heuristic to minimize the makespan for the permutation flow shop scheduling problem. The results of implementation of the proposed method are compared with other existing ant colony optimization technique. The preliminary results indicate that the new proposed method performs better than the ant colony for some well known benchmark problems.
Matrix genetics, part 1: permutations of positions in triplets and symmetries of genetic matrices
Petoukhov, Sergey V
2008-01-01
The hidden connection between the degeneracy of the vertebrate mitochondria genetic code and the positional permutations inside genetic triplets is described. The Kronecker family of the genetic matrices is investigated, which is based on the genetic matrix [C A; U G], where C, A, U, G are the letters of the genetic alphabet. The natural system of binary numeration of genetic multiplets in the genetic matrices is proposed. The matrix [C A; U G] in the third Kronecker power is the (8*8)-matrix, which contains 64 triplets. When 64 triplets in this matrix are numbered in accordance with the natural system, the coincidence with the famous table of 64 hexagrams of the ancient Chinese book "I Ching" arises. It is significant that peculiarities of the degeneracy of the vertebrate mitochondria genetic code are reflected in the symmetrical black-and-white mosaic of this genetic (8*8)-matrix of 64 triplets. This matrix is reformed into a new mosaic matrix when internal positions in all triplets are permuted simultaneou...
Robust and fragile entanglement of three qubits: Relation to permutation symmetry
International Nuclear Information System (INIS)
The robustness of entanglement for the set of eight total spin states of three qubits is characterized and related to their permutation symmetries. These states fall into four sets of two entangled states, differing in their patterns of robustness to entanglement when one of the states is lost. Their entanglement measures are shown to contain certain permutation symmetries of the spin states and their corresponding marginal two-particle states. The eight entangled states are also found to be eigenstates of the Heisenberg Hamiltonian, σ-vectorA·σ-vectorB+σ-vectorA·σ-vectorC+σ-vectorB·σ-vectorC/2. This allows the entanglement to be tuned in a systematic way by adjusting the symmetries of a general three-qubit Hamiltonian. The necessary and sufficient conditions for separability of a general three-particle state in terms of (a) three one-particle states and (b) one one-particle and one two-particle state are also given
Random walk generated by random permutations of {1, 2, 3, ..., n + 1}
International Nuclear Information System (INIS)
We study properties of a non-Markovian random walk X(n)l, l = 0, 1, 2, ..., n, evolving in discrete time l on a one-dimensional lattice of integers, whose moves to the right or to the left are prescribed by the rise-and-descent sequences characterizing random permutations π of [n + 1] = {1, 2, 3, ..., n + 1}. We determine exactly the probability of finding the end-point Xn = X(n)n of the trajectory of such a permutation-generated random walk (PGRW) at site X, and show that in the limit n → ∞ it converges to a normal distribution with a smaller, compared to the conventional Polya random walk, diffusion coefficient. We formulate, as well, an auxiliary stochastic process whose distribution is identical to the distribution of the intermediate points X(n)l, l < n, which enables us to obtain the probability measure of different excursions and to define the asymptotic distribution of the number of 'turns' of the PGRW trajectories
International Nuclear Information System (INIS)
In the replica-permutation method (RPM), temperatures are not only exchanged between two replicas but also permutated among more than two replicas using the Suwa–Todo algorithm, which minimizes the rejection ratio in Monte Carlo trials. We verify the sampling efficiency of RPM that adopts Suwa–Todo algorithms with and without a detailed balance condition (DBC). To compare these techniques, molecular dynamics simulations of RPM with and without the DBC and the replica-exchange method (REM) were carried out for a chignolin molecule in explicit water. Although no difference in the numbers of folding and unfolding events was observed, the numbers of tunneling events of the two RPM simulations were larger than that of REM. This indicates that the minimization of the rejection ratio by the Suwa–Todo algorithm in RPM realizes efficient sampling. Furthermore, the sampling efficiency was slightly higher in the RPM without the DBC than in that with the DBC. The reason for this difference is also discussed. (author)
On the class of square Petrie matrices induced by cyclic permutations
Directory of Open Access Journals (Sweden)
Bau-Sen Du
2004-07-01
Full Text Available Let nÃ¢Â‰Â¥2 be an integer and let P={1,2,Ã¢Â€Â¦,n,n+1}. Let Zp denote the finite field {0,1,2,Ã¢Â€Â¦,pÃ¢ÂˆÂ’1}, where pÃ¢Â‰Â¥2 is a prime. Then every map ÃÂƒ on P determines a real nÃƒÂ—n Petrie matrix AÃÂƒ which is known to contain information on the dynamical properties such as topological entropy and the Artin-Mazur zeta function of the linearization of ÃÂƒ. In this paper, we show that if ÃÂƒ is a cyclic permutation on P, then all such matrices AÃÂƒ are similar to one another over Z2 (but not over Zp for any prime pÃ¢Â‰Â¥3 and their characteristic polynomials over Z2 are all equal to Ã¢ÂˆÂ‘k=0nxk. As a consequence, we obtain that if ÃÂƒ is a cyclic permutation on P, then the coefficients of the characteristic polynomial of AÃÂƒ are all odd integers and hence nonzero.
Convex mappings on some circular domains
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
In this paper,we consider some circular domains.And we give an extension theorem for some normalized biholomorphic convex mapping on some circular domains.Especially,we discover the normalized biholomorphic convex mapping on some circular domains have the form f(z) =(f1(z1),...,fn(zn)),where fj:D → C are normalized biholomorphic convex mapping.
Energy dissipation in circular tube
Directory of Open Access Journals (Sweden)
A.D. Girgidov
2012-01-01
Full Text Available Energy dissipation distribution along the circular tube radius is important in solving such problems as calculation of heat transfer by the air flow through building envelope; calculation of pressure loss in spiral flows; calculation of cyclones with axial and tangential supply of dust-containing gas.Two types of one-dimensional radially axisymmetric flows in circular tube were considered: axial flow and rotation about the axis (Rankine vortex. Relying on two- and four-layer description of axial turbulent flow energy dissipation was calculated in each layer.Similar calculation for Rankine vortex with viscous sublayer at the tube surface was provided. By employing the dissipation minimum principle the boundary radius between rigid rotation and free vortex is calculated. Approximation of the velocity distribution in Rankine vortex is proposed.
Capacitance of circular patch resonator
International Nuclear Information System (INIS)
In this paper the capacitance of the circular microstrip patch resonator is computed. It is shown that the electrostatic problem can be formulated as a system of dual integral equations, and the most interesting techniques of solutions of these systems are reviewed. Some useful approximated formulas for the capacitance are derived and plots of the capacitance are finally given in a wide range of dielectric constants
Capacitance of circular patch resonator
Energy Technology Data Exchange (ETDEWEB)
Miano, G.; Verolino, L. [Dip. di Ingegneria Elettrica, Ist. Nazionale di Fisica Nucleare, Naples (Italy); Panariello, G. [Dip. di Ingegneria Elettronica, Naples (Italy); Vaccaro, V.G. [Ist. Nazionale di Fisica Nucleare, Naples (Italy). Dipt. di Scienze Fisiche
1995-11-01
In this paper the capacitance of the circular microstrip patch resonator is computed. It is shown that the electrostatic problem can be formulated as a system of dual integral equations, and the most interesting techniques of solutions of these systems are reviewed. Some useful approximated formulas for the capacitance are derived and plots of the capacitance are finally given in a wide range of dielectric constants.
Longitudinal motion in circular accelerators
International Nuclear Information System (INIS)
A general description is given of the longitudinal motion of an idealized synchronous particle, exactly in step with the radiofrequency field of a circular accelerator, and a domain in phase and energy, called a bucket, around this particle within which particles are focused around the synchronous particle. This general picture is then made more precise and quantitative. The equations of longitudinal motion and their solutions and the resulting motion are discussed, followed by applications and amplication of the theory. 7 refs., 8 figs
Circular Polarization in Pulsar Integrated Profiles: Updates
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
We update the systematic studies of circular polarization in integrated pulse profiles by Han et al. Data of circular polarization profiles are compiled. Sense reversals can occur in core or cone components, or near the intersection between components. The correlation between the sense of circular polarization and the sense of position angle variation for conal-double pulsars is confirmed with a much large database. Circular polarization of some pulsars has clear changes with frequency.Circular polarization of millisecond pulsars is marginally different from that of normal pulsars.
Total positive curvature of circular DNA
DEFF Research Database (Denmark)
Bohr, Jakob; Olsen, Kasper Wibeck
2013-01-01
micro-DNAs longer than the minimum length must be concave, a result that is consistent with typical atomic force microscopy images of plasmids. Predictions for the total positive curvature of circular micro-DNAs are given as a function of length, and comparisons with circular DNAs from the literature...... molecules, e.g., plasmids, it is shown to have implications for the total positive curvature integral. For small circular micro-DNAs it follows as a consequence of Fenchel's inequality that there must exist a minimum length for the circular plasmids to be double stranded. It also follows that all circular...
Generalised Permutation Branes on a product of cosets $G_{k_1}/H\\times G_{k_2}/H$
Sarkissian, Gor
2006-01-01
We study the modifications of the generalized permutation branes defined in hep-th/0509153, which are required to give rise to the non-factorizable branes on a product of cosets $G_{k_1}/H\\times G_{k_2}/H$. We find that for $k_1\
DEFF Research Database (Denmark)
Bogdanov, Andrey; Knudsen, L.R.; Leander, Gregor;
2012-01-01
This paper considers—for the first time—the concept of key-alternating ciphers in a provable security setting. Key-alternating ciphers can be seen as a generalization of a construction proposed by Even and Mansour in 1991. This construction builds a block cipher PX from an n-bit permutation P and...
Hirata, Shuzo; Vacha, Martin
2016-04-21
Circularly polarized room-temperature phosphorescence (RTP) with persistent emission characteristics was observed from metal-free chiral binaphthyl structures. Enantiomers of the binaphthyl compounds doped into an amorphous hydroxylated steroid matrix produced blue fluorescence and yellow persistent RTP in air. The lifetime and quantum yield of the yellow persistent RTP were 0.67 s and 2.3%, respectively. The dissymmetry factors of circular dichroism (CD) in the first absorption band, circularly polarized fluorescence (CPF), and circularly polarized persistent RTP were |1.1 × 10(-3)|, |4.5 × 10(-4)|, and |2.3 × 10(-3)|, respectively. A comparison between the experimental data and calculations by time-dependent density functional theory for transient CD spectra confirmed that the binaphthyl conformations in the lowest singlet excited state (S1) and the lowest triplet state (T1) were different. The large difference in the dissymmetry factors for the CPF and the circularly polarized persistent RTP was likely caused by this conformational change between S1 and T1. PMID:27058743
Permutation entropy analysis of density fluctuations in the torsatron TJ-K
International Nuclear Information System (INIS)
In order to explore the nature of density fluctuations in the edge of magnetically confined fusion plasmas, the technique of permutation entropy and statistical complexity is used. The location of fluctuations on the entropy versus complexity plane classifies the dynamical behaviour of the system. The behaviour can be differentiated between stochastic and chaotic. The latter is supposed to be connected to a specific temporal form of intermittent density events, i.e. blobs, in the scrape-off layer (SOL). In this contribution, density fluctuations measured with a Langmuir probe in the torsatron TJ-K are analyzed with respect to the dynamical nature. Radial scans are performed across the separatrix to distinguish the dynamics in the inner edge and the SOL. Comparisons with well known test systems indeed point to a qualitative change in the dynamics across the separatrix. In the region of maximum density gradient, the fluctuations are characterized by minimum entropy. The results will be discussed on separated scales.
Permutation operators, entanglement entropy, and the XXZ spin chain in the limit Δ→-1+
International Nuclear Information System (INIS)
In this paper we develop a new approach to the investigation of the bi-partite entanglement entropy in integrable quantum spin chains. Our method employs the well-known replica trick, thus taking a replica version of the spin chain model as starting point. At each site i of this new model we construct an operator Ti which acts as a cyclic permutation among the n replicas of the model. Infinite products of Ti give rise to local operators, precursors of branch-point twist fields of quantum field theory. The entanglement entropy is then expressed in terms of correlation functions of such operators. Employing this approach we investigate the von Neumann and Rényi entropies of a particularly interesting quantum state occurring as a limit (in a compact convergence topology) of the antiferromagnetic XXZ quantum spin chain. We find that, for large sizes, the entropy scales logarithmically, but not conformally
Rock, Ariel; Parks, Holden; Schaffner, David; Brown, Michael
2015-11-01
Statistical properties of various turbulent laboratory and natural (magneto)fluids are investigated using both complexity measures of ordinal pattern distribution and temporal increments. The systems analyzed are solar wind | B | time series from the Cluster satellites, streamwise velocity time series from the Johns Hopkins University Corsin Wind Tunnel, and | Ḃ | time series from the Swarthmore Spheromak Experiment (SSX) MHD wind tunnel. Plasma in the SSX wind tunnel has parameters B ~ . 2 T, n >=1021 m-3, and Ti >= 20 eV. By comparing the permutation entropy and Jensen-Shannon complexity with the behavior of the structure functions derived from the intermittency analysis, the connections between the complexity measures and dissipation mechanisms can be determined. The Corsin Wind Tunnel velocity data is used to compare the statistical signatures of dissipation in conventional hydrofluids with that seen in magnetofluids. Work supported by DOE OFES and NSF CMSO.
Bilarge neutrino mixing and μ-τ permutation symmetry for two-loop radiative mechanism
International Nuclear Information System (INIS)
The presence of approximate electron number conservation and μ-τ permutation symmetry of S2 is shown to naturally provide bilarge neutrino mixing. First, the bimaximal neutrino mixing together with Ue3=0 is guaranteed to appear owing to S2, and then, the bilarge neutrino mixing together with |Ue3|2. The observed mass hierarchy of Δm·2 atm2 is subject to another tiny violation of the electron number conservation. This scenario is realized in a specific model based on SU(3)LxU(1)N with two-loop radiative mechanism for neutrino masses. The radiative effects from heavy leptons contained in lepton triplets generate the bimaximal structure, and those from charged leptons, which break S2, generate the bilarge structure together with vertical bar Ue3 vertical bar 2 symmetry is extended to a discrete Z8 symmetry, which also ensures the absence of a one-loop radiative mechanism
Yang-Baxter equation, parameter permutations, and the elliptic beta integral
International Nuclear Information System (INIS)
This paper presents a construction of an infinite-dimensional solution of the Yang-Baxter equation of rank 1 which is represented as an integral operator with an elliptic hypergeometric kernel acting in the space of functions of two complex variables. This R-operator intertwines the product of two standard L-operators associated with the Sklyanin algebra, an elliptic deformation of the algebra sl(2). The solution is constructed from three basic operators S1, S2, and S3 generating the permutation group S4 on four parameters. Validity of the key Coxeter relations (including a star-triangle relation) is based on the formula for computing an elliptic beta integral and the Bailey lemma associated with an elliptic Fourier transformation. The operators Sj are determined uniquely with the help of the elliptic modular double. Bibliography: 37 titles
Permutation symmetry S3 and vacuum expectation value structure of flavor-triplet Higgs scalars
International Nuclear Information System (INIS)
A model with flavor-triplet Higgs scalars φi (i=1,2,3) is investigated under a permutation symmetry S3 and its symmetry breaking. A possible S3 breaking form of the Higgs potential whose vacuum expectation values vi=i> satisfy a relation v12+v22+v32=(2/3)(v1+v2+v3)2 is investigated, because if we suppose a seesaw-like mass matrix model Me=mM-1m with mij∝δijvi and Mij∝δij, such a model can lead to the well-known charged lepton mass relation me+mμ+mτ=(2/3)(√(me)+√(mμ)+√(mτ))2
Quantum tests for the linearity and permutation invariance of Boolean functions
International Nuclear Information System (INIS)
The goal in function property testing is to determine whether a black-box Boolean function has a certain property or is ε-far from having that property. The performance of the algorithm is judged by how many calls need to be made to the black box in order to determine, with high probability, which of the two alternatives is the case. Here we present two quantum algorithms, the first to determine whether the function is linear and the second to determine whether it is symmetric (invariant under permutations of the arguments). Both require order ε-2/3 calls to the oracle, which is better than known classical algorithms. In addition, in the case of linearity testing, if the function is linear, the quantum algorithm identifies which linear function it is. The linearity test combines the Bernstein-Vazirani algorithm and amplitude amplification, while the test to determine whether a function is symmetric uses projective measurements and amplitude amplification.
Invariance groups of finite functions and orbit equivalence of permutation groups
Directory of Open Access Journals (Sweden)
Horváth Eszter K.
2015-01-01
Full Text Available Which subgroups of the symmetric group Sn arise as invariance groups of n-variable functions defined on a k-element domain? It appears that the higher the difference n-k, the more difficult it is to answer this question. For k ≤ n, the answer is easy: all subgroups of Sn are invariance groups. We give a complete answer in the cases k = n-1 and k = n-2, and we also give a partial answer in the general case: we describe invariance groups when n is much larger than n-k. The proof utilizes Galois connections and the corresponding closure operators on Sn, which turn out to provide a generalization of orbit equivalence of permutation groups. We also present some computational results, which show that all primitive groups except for the alternating groups arise as invariance groups of functions defined on a three-element domain.
Accurate DOSY measure of out-of-equilibrium systems by permutated DOSY (p-DOSY)
Oikonomou, Maria; Velders, Aldrik H; Delsuc, Marc-André
2015-01-01
NMR spectroscopy is a perfect tool for monitoring in-situ chemical reactions. In particular, DOSY measurement is well suited to characterize transient species by the determination of their sizes. However, here we bring to light a difficulty in the DOSY experiments performed on out-of-equilibrium systems. On such a system, the evolution of the concentration of species interferes with the measurement process, and creates a bias on the diffusion coefficient determination that may lead to erroneous interpretations. We show that a random permutation of the series of gradient strengths used during the DOSY experiment allows to average out this bias. This approach, that we name p-DOSY does not require changes in the the pulse sequences nor in the processing software, and restores completely the full accuracy of the measure. This technique is demonstrated on the monitoring of the anomerization reaction of $\\alpha$ to $\\beta$ glucose.
Acharyya, Amit; Maharatna, Koushik; Al-Hashimi, Bashir M; Mondal, Sayanta
2010-01-01
In this paper we propose a novel channel identification scheme for solving permutation indeterminacy introduced by Independent Component Analysis (ICA) for artifacts removal from recorded three channel ECG signals within the remote health monitoring environment. The proposed scheme does not depend on the definition of any specific artifact which is the case with the existing approach and therefore leads to more robust and generic solution to this problem. The proposed scheme has been validated using nine practical case studies and its robustness has been proved by comparison with the existing approach. Simulation results show that the proposed scheme works successfully for all the nine cases whereas the existing approach fails to identify the correct channel for four cases. PMID:21096325
Bit Reversal through Direct Fourier Permutation Method and Vectorial Digit Reversal Generalization
Popescu-Bodorin, Nicolaie
2011-01-01
This paper describes the Direct Fourier Permuation Algorithm, an efficient method of computing Bit Reversal of natural indices [1, 2, 3, ..., 2^k] in a vectorial manner (k iterations) and also proposes the Vectorial Digit Reversal Algorithm, a natural generalization of Direct Fourier Permutation Algorithm that is enabled to compute the r-digit reversal of natural indices [1, 2, 3, ..., r^k] where r is an arbitrary radix. Matlab functions implementing these two algo- rithms and various test and comparative results are presented in this paper to support the idea of inclusion of these two algorithms in the next Matlab Signal Processing Toolbox official distribution package as much faster alternatives to current Matlab functions bitrevorder and digitrevorder.
Permutation methods for the structured exploratory data analysis (SEDA) of familial trait values.
Karlin, S; Williams, P T
1984-07-01
A collection of functions that contrast familial trait values between and across generations is proposed for studying transmission effects and other collateral influences in nuclear families. Two classes of structured exploratory data analysis (SEDA) statistics are derived from ratios of these functions. SEDA-functionals are the empirical cumulative distributions of the ratio of the two contrasts computed within each family. SEDA-indices are formed by first averaging the numerator and denominator contrasts separately over the population and then forming their ratio. The significance of SEDA results are determined by a spectrum of permutation techniques that selectively shuffle the trait values across families. The process systematically alters certain family structure relationships while keeping other familial relationships intact. The methodology is applied to five data examples of plasma total cholesterol concentrations, reported height values, dermatoglyphic pattern intensity index scores, measurements of dopamine-beta-hydroxylase activity, and psychometric cognitive test results. PMID:6475959
Optimization of a parallel permutation testing function for the SPRINT R package.
Petrou, Savvas; Sloan, Terence M; Mewissen, Muriel; Forster, Thorsten; Piotrowski, Michal; Dobrzelecki, Bartosz; Ghazal, Peter; Trew, Arthur; Hill, Jon
2011-12-10
The statistical language R and its Bioconductor package are favoured by many biostatisticians for processing microarray data. The amount of data produced by some analyses has reached the limits of many common bioinformatics computing infrastructures. High Performance Computing systems offer a solution to this issue. The Simple Parallel R Interface (SPRINT) is a package that provides biostatisticians with easy access to High Performance Computing systems and allows the addition of parallelized functions to R. Previous work has established that the SPRINT implementation of an R permutation testing function has close to optimal scaling on up to 512 processors on a supercomputer. Access to supercomputers, however, is not always possible, and so the work presented here compares the performance of the SPRINT implementation on a supercomputer with benchmarks on a range of platforms including cloud resources and a common desktop machine with multiprocessing capabilities. Copyright © 2011 John Wiley & Sons, Ltd. PMID:23335858
Deterministic Circular Self Test Path
Institute of Scientific and Technical Information of China (English)
WEN Ke; HU Yu; LI Xiaowei
2007-01-01
Circular self test path (CSTP) is an attractive technique for testing digital integrated circuits(IC) in the nanometer era, because it can easily provide at-speed test with small test data volume and short test application time. However, CSTP cannot reliably attain high fault coverage because of difficulty of testing random-pattern-resistant faults. This paper presents a deterministic CSTP (DCSTP) structure that consists of a DCSTP chain and jumping logic, to attain high fault coverage with low area overhead. Experimental results on ISCAS'89 benchmarks show that 100% fault coverage can be obtained with low area overhead and CPU time, especially for large circuits.
International Nuclear Information System (INIS)
Laser-induced breakdown spectroscopy (LIBS) has been investigated for the discrimination of automobile paint samples. Paint samples from automobiles of different makes, models, and years were collected and separated into sets based on the color, presence or absence of effect pigments and the number of paint layers. Twelve LIBS spectra were obtained for each paint sample, each an average of a five single shot 'drill down' spectra from consecutive laser ablations in the same spot on the sample. Analyses by a nonparametric permutation test and a parametric Wald test were performed to determine the extent of discrimination within each set of paint samples. The discrimination power and Type I error were assessed for each data analysis method. Conversion of the spectral intensity to a log-scale (base 10) resulted in a higher overall discrimination power while observing the same significance level. Working on the log-scale, the nonparametric permutation tests gave an overall 89.83% discrimination power with a size of Type I error being 4.44% at the nominal significance level of 5%. White paint samples, as a group, were the most difficult to differentiate with the power being only 86.56% followed by 95.83% for black paint samples. Parametric analysis of the data set produced lower discrimination (85.17%) with 3.33% Type I errors, which is not recommended for both theoretical and practical considerations. The nonparametric testing method is applicable across many analytical comparisons, with the specific application described here being the pairwise comparison of automotive paint samples.
Permutation asymmetry of the relativistic velocity addition law and non-Euclidean geometry
International Nuclear Information System (INIS)
The asymmetry of the relativistic addition law for noncollinear velocities under the velocity permutation leads to two modified triangles on a Euclidean plane depicting the addition of unpermuted and permuted velocities and the appearance of a nonzero angle ω between two resulting velocities. A particle spin rotates through the same angle ω under a Lorentz boost with a velocity noncollinear to the particle velocity. Three mutually connected three-parameter representations of the angle ω, obtained by the author earlier, express the three-parameter symmetry of the sides and angles of two Euclidean triangles identical to the sine and cosine theorems for the sides and angles of a single geodesic triangle on the surface of a pseudosphere. Namely, all three representations of the angle ω, after a transformation of one of them, coincide with the representations of the area of a pseudospherical triangle expressed in terms of any two of its sides and the angle between them. The angle ω is also symmetrically expressed in terms of three angles or three sides of a geodesic triangle, and therefore it is an invariant of the group of triangle motions over the pseudo-sphere surface, the group that includes the Lorentz group. Although the pseudospheres in Euclidean and pseudo-Euclidean spaces are locally isometric, only the latter is isometric to the entire Lobachevsky plane and forms a homogeneous isotropic curved 4-velocity space in the flat Minkowski space. In this connection, relativistic physical processes that may be related to the pseudosphere in Euclidean space are especially interesting. (methodological notes)
Ritus, V. I.
2008-07-01
The asymmetry of the relativistic addition law for noncollinear velocities under the velocity permutation leads to two modified triangles on a Euclidean plane depicting the addition of unpermuted and permuted velocities and the appearance of a nonzero angle ω between two resulting velocities. A particle spin rotates through the same angle ω under a Lorentz boost with a velocity noncollinear to the particle velocity. Three mutually connected three-parameter representations of the angle ω, obtained by the author earlier, express the three-parameter symmetry of the sides and angles of two Euclidean triangles identical to the sine and cosine theorems for the sides and angles of a single geodesic triangle on the surface of a pseudosphere. Namely, all three representations of the angle ω, after a transformation of one of them, coincide with the representations of the area of a pseudospherical triangle expressed in terms of any two of its sides and the angle between them. The angle ω is also symmetrically expressed in terms of three angles or three sides of a geodesic triangle, and therefore it is an invariant of the group of triangle motions over the pseudo-sphere surface, the group that includes the Lorentz group. Although the pseudospheres in Euclidean and pseudo-Euclidean spaces are locally isometric, only the latter is isometric to the entire Lobachevsky plane and forms a homogeneous isotropic curved 4-velocity space in the flat Minkowski space. In this connection, relativistic physical processes that may be related to the pseudosphere in Euclidean space are especially interesting.
Aalto, Juha; Pirinen, Pentti; Jylhä, Kirsti
2016-04-01
Long-term time series of key climate variables with a relevant spatiotemporal resolution are essential for environmental science. Moreover, such spatially continuous data, based on weather observations, are commonly used in, e.g., downscaling and bias correcting of climate model simulations. Here we conducted a comprehensive spatial interpolation scheme where seven climate variables (daily mean, maximum, and minimum surface air temperatures, daily precipitation sum, relative humidity, sea level air pressure, and snow depth) were interpolated over Finland at the spatial resolution of 10 × 10 km2. More precisely, (1) we produced daily gridded time series (FMI_ClimGrid) of the variables covering the period of 1961-2010, with a special focus on evaluation and permutation-based uncertainty estimates, and (2) we investigated temporal trends in the climate variables based on the gridded data. National climate station observations were supplemented by records from the surrounding countries, and kriging interpolation was applied to account for topography and water bodies. For daily precipitation sum and snow depth, a two-stage interpolation with a binary classifier was deployed for an accurate delineation of areas with no precipitation or snow. A robust cross-validation indicated a good agreement between the observed and interpolated values especially for the temperature variables and air pressure, although the effect of seasons was evident. Permutation-based analysis suggested increased uncertainty toward northern areas, thus identifying regions with suboptimal station density. Finally, several variables had a statistically significant trend indicating a clear but locally varying signal of climate change during the last five decades.
Physics at Future Circular Colliders
Kotwal, Ashutosh
2016-03-01
The Large Hadron Collider has been a grand success with the discovery of the Higgs boson, with bright prospects for additional discoveries since the recent increase in collider energy and the anticipated large datasets. Big open questions such as the nature of dark matter, the origin of the matter-antimatter asymmetry in the Universe, and the theoretical puzzle of the finely-tuned parameters in the Higgs sector, demand new physics principles that extend the established Standard Model paradigm. Future circular colliders in a substantially larger tunnel can house both a high luminosity electron-positron collider for precision measurements of Higgs and electroweak parameters, as well as a very high energy proton-proton collider which can directly manifest particles associated with these new physics principles. We discuss the physics goals of these future circular colliders, and the prospects for elucidating fundamental new laws of nature that will significantly extend our understanding of the Universe. Detailed studies of the discovery potential in specific benchmark models will be presented, with implications for detector design.
Mixing in Circular and Non-circular Jets in Crossflow
DEFF Research Database (Denmark)
Salewski, Mirko; Stankovic, D.; Fuchs, L.
2008-01-01
are compared for circular, elliptic, and square nozzles. For the latter configurations, effects of orientation are considered. The computations reveal that the distribution of a passive scalar in a cross-sectional plane can be single- or double-peaked, depending on the nozzle shape and orientation. A proper...... orthogonal decomposition of the transverse velocity indicates that coherent structures may be responsible for this phenomenon. Nozzles which have a single-peaked distribution have stronger modes in transverse direction. The global mixing performance is superior for these nozzle types. This is the case...... for the blunt square nozzle and for the elliptic nozzle with high aspect ratio. It is further demonstrated that the flow field contains large regions in which a passive scalar is transported up the mean gradient (counter-gradient transport) which implies failure of the gradient diffusion hypothesis....
CIRCULAR ECONOMY IN ROMANIA WITHIN EUROPEAN CONTEXT
Cornelia Marcela Danu; Valentin Nedeff
2015-01-01
In the present paper we have approached some conceptual and coordinated marks of the societal reality connected to the circular economy. Generated by „the limits of certainty” regarding the future of the world business, the operationalization of the circular economy has become a part of the EU strategies and started the various stages of implementation as an active process in all countries. We have highlighted the opportunities and the risks related to the circular economy, the European dimen...
A COMPACT CIRCULARLY POLARIZED SLOTTED MICROSTRIP ANTENNA
V. Jebaraj; K.R.S. Ravi Kumar; D. Mohanageetha
2014-01-01
Slot antennas are often used at UHF and microwave frequencies. In slot antenna for RFID reader applications the frequency ranges from 902-923MHz to achieve circular polarization. The shapes and size of the slot, as well as the driving frequency, determine the radiation distribution pattern. The proposed compact size circularly polarized slotted microstrip antenna are summarized with design rules. The circularly polarized radiation in square patch antenna can be obtained by perturbation techni...
Reconfigurable Monopole Antennas With Circular Polarization
Panahi, Afshin
2015-01-01
This thesis presents research on printed circularly-polarized monopole antennas and their application in reconfigurable monopole antennas. The proposed circularly-polarised monopole antennas benefit from advantages such as small size, low-cost, low-profile and simple designs. The first part of this thesis introduces three printed circularly-polarized monopole antennas for global navigation satellite systems and Wi-Fi applications. The primary focus is on the ground plane which is used as a ra...
Molecular alignment using circularly polarized laser pulses
Smeenk, C T L
2013-01-01
We show that circularly polarized femtosecond laser pulses produce field-free alignment in linear and planar molecules. We study the rotational wavepacket evolution of O$_2$ and benzene created by circularly polarized light. For benzene, we align the molecular plane to the plane of polarization. For O$_2$, we demonstrate that circular polarization yields a net alignment along the laser propagation axis at certain phases of the evolution. Circular polarization gives us the ability to control alignment of linear molecules outside the plane of polarization, providing new capabilities for molecular imaging.
Pinyol i Bori, Francesc
2007-01-01
És un text epistemològic sobre les qüestions cognitives circulars que apareixen: a) Quan el subjecte forma part de l'objecte estudiat; b) En la recerca de les bases del coneixement; c) Al voler justificar la inducció; d) En algunes interpretacions filosòfiques i científiques. S'hi explica l'estat del punt a) el més problemàtic, i s'aclareixen els altres tres punts: els b) i c) pel fet científic que l'evolució cognitiva humana ha anat acoblada a l'evolució biològica, la qual ha generat els a p...
Microstrip Antenna Generates Circularly Polarized Beam
Huang, J.
1986-01-01
Circular microstrip antenna excited with higher order transverse magnetic (TM) modes generates circularly polarized, conical radiation patterns. Found both theoretically and experimentally that peak direction of radiation pattern is varied within wide angular range by combination of mode selection and loading substrate with materials of different dielectric constants.
Circular Loudspeaker Array with Controllable Directivity
DEFF Research Database (Denmark)
Møller, Martin; Olsen, Martin; Agerkvist, Finn T.;
2010-01-01
Specific directivity patterns for circular arrays of loudspeakers can be achieved by utilizing the concept of phase-modes, which expands the directivity pattern into a series of circular harmonics. This paper investigates the applicability of this concept applied on a loudspeaker array on a...
International Nuclear Information System (INIS)
With the help of a projection operator P defined on a nonstandard basis of the permutation group, the equations of the resonating group method are written for the case of a given permutation symmetry [ f]. Construction of the operator P is discussed for the example of d+d scattering, and the integral equations of the resonating group method are presented for several different symmetries [ f]. It is shown that these equations satisfy the quasiclassical criterion of the existence of effective local potentials. The potentials obtained are close to the phenomenological ones. Thus, a basis is provided for the generalized potential approach to d+d, d+p, d+h, d+6Li, etc. scattering, including the inelastic spin-flip and isospin-flip channels. The formal problem solved in the present paper is also of relevance for the N+N system on the quark level
International Nuclear Information System (INIS)
We consider a AN-1 type of spin-dependent Calogero-Sutherland model, containing an arbitrary representation of the permutation operators on the combined internal space of all particles, and find that such a model can be solved as easily as its standard su(M) invariant counterpart through the diagonalisation of Dunkl operators. A class of novel representations of the permutation operator Pij, which pick up non-trivial phase factors along with interchanging the spins of the ith and jth particles, are subsequently constructed. These 'anyon-like' representations interestingly lead to different variants of the spin Calogero-Sutherland model with highly non-local interactions. We also explicitly derive some exact eigenfunctions as well as energy eigenvalues of these models and observe that the related degeneracy factors crucially depend on the choice of a few discrete parameters which characterise such anyon-like representations. (orig.)
CIRCULAR ECONOMY IN ROMANIA WITHIN EUROPEAN CONTEXT
Directory of Open Access Journals (Sweden)
Cornelia Marcela Danu
2015-07-01
Full Text Available In the present paper we have approached some conceptual and coordinated marks of the societal reality connected to the circular economy. Generated by „the limits of certainty” regarding the future of the world business, the operationalization of the circular economy has become a part of the EU strategies and started the various stages of implementation as an active process in all countries. We have highlighted the opportunities and the risks related to the circular economy, the European dimension and, in particular, the Romanian one of this process, the role of the triad: consumer-company-natural environment, while implementing the circular economy. Circular economy is both a new approach of the societal life, based on changing the mentalities of the individuals having the role of decision makers at the company level and public administration and the decision makers – consumers, as well as a policy meant to be made operational across all entities: governmental, entrepreneurial, individually – human.
Gauge-Invariant Formulation of Circular Dichroism.
Raimbault, Nathaniel; de Boeij, Paul L; Romaniello, Pina; Berger, J A
2016-07-12
Standard formulations of magnetic response properties, such as circular dichroism spectra, are plagued by gauge dependencies, which can lead to unphysical results. In this work, we present a general gauge-invariant and numerically efficient approach for the calculation of circular dichroism spectra from the current density. First we show that in this formulation the optical rotation tensor, the response function from which circular dichroism spectra can be obtained, is independent of the origin of the coordinate system. We then demonstrate that its trace is independent of the gauge origin of the vector potential. We also show how gauge invariance can be retained in practical calculations with finite basis sets. As an example, we explain how our method can be applied to time-dependent current-density-functional theory. Finally, we report gauge-invariant circular dichroism spectra obtained using the adiabatic local-density approximation. The circular dichroism spectra we thus obtain are in good agreement with experiment. PMID:27295541
Nanofocusing in circular sector-like nanoantennas
DEFF Research Database (Denmark)
Zenin, Volodymyr; Pors, Anders Lambertus; Han, Zhanghua;
2014-01-01
Gold circular sector-like nanoantennas (with a radius of 500 nm and a taper angle of 60°, 90°, and 120°) on glass are investigated in a near-infrared wavelength range (900 - 2100 nm). Amplitude- and phase-resolved near-field images of circular sector-like antenna modes at telecom wavelength feature...... a concentric circular line of phase contrast, demonstrating resonant excitation of a standing wave of counter-propagating surface plasmons, travelling between a tip and opposite circular edge of the antenna. Transmission spectra obtained in the range 900 - 2100 nm are in good agreement with...... makes circular sector-like nanoantennas very promising for implementing bowtie antennas and attractive for many applications....
Visualizing Single-molecule DNA Replication with Fluorescence Microscopy
Tanner, Nathan A.; Loparo, Joseph J.; Oijen, Antoine M. van
2009-01-01
We describe a simple fluorescence microscopy-based real-time method for observing DNA replication at the single-molecule level. A circular, forked DNA template is attached to a functionalized glass coverslip and replicated extensively after introduction of replication proteins and nucleotides. The g
Shadrokh, Ali
2007-01-01
When the data generation process does not satisfy some of the assumptions founding the statistical inferences in the classic linear regression model, permutation tests offer a reliable nonparametric alternative for constructing distribution-free tests. The first application of the permutation test methodology for statistical inference on the simple linear regression model can be traced back to papers by Fisher (1935) and Pitman (1937a, b, 1938). This resampling method is founded on hypothesis...
Albert, Mélisande
2015-01-01
On the one hand, we construct such tests based on bootstrap and permutation approaches. Their asymptotic performance are studied in a point process framework through the analysis of the asymptotic behavior of the conditional distributions of both bootstrapped and permuted test statistics, under the null hypothesis as well as under any alternative. A simulation study is performed verifying the usability of these tests in practice, and comparing them to existing classical methods in Neuroscienc...
Polynômes de permutation et applications en cryptographie - Cryptanalyse de registres combinés
Laigle-Chapuy, Yann
2009-01-01
This thesis adresses two different aspects of cryptology: the design of new ciphers and the cryptanalysis of existing systems. The first part deals with permutation polynomials. We first introduce the basic properties of those objects before presenting the different known classes of such polynomials. We will also consider the problem of the repartition of those polynomials Finally we will review different situations where those polynomials occur in cryptology. We will especially detail the li...
Färber, Gerrit Hartmut; Coves Moreno, Anna Maria
2006-01-01
This paper presents the performance study of a Genetic Algorithm applied to a mixed model non-permutation flowshop production line. Resequencing is permitted where stations have access to intermittent or centralized resequencing buffers. The access to the buffers is restricted by the number of available buffer places and the physical size of the products. Characteristics such as the difference between the intermittent and the centralized case, the number of buffer places and the distributi...
Schmiedt, Hanno; Jensen, Per; Schlemmer, Stephan
2016-08-21
In modern physics and chemistry concerned with many-body systems, one of the mainstays is identical-particle-permutation symmetry. In particular, both the intra-molecular dynamics of a single molecule and the inter-molecular dynamics associated, for example, with reactive molecular collisions are strongly affected by selection rules originating in nuclear-permutation symmetry operations being applied to the total internal wavefunctions, including nuclear spin, of the molecules involved. We propose here a general tool to determine coherently the permutation symmetry and the rotational symmetry (associated with the group of arbitrary rotations of the entire molecule in space) of molecular wavefunctions, in particular the nuclear-spin functions. Thus far, these two symmetries were believed to be mutually independent and it has even been argued that under certain circumstances, it is impossible to establish a one-to-one correspondence between them. However, using the Schur-Weyl duality theorem we show that the two types of symmetry are inherently coupled. In addition, we use the ingenious representation-theory technique of Young tableaus to represent the molecular nuclear-spin degrees of freedom in terms of well-defined mathematical objects. This simplifies the symmetry classification of the nuclear wavefunction even for large molecules. Also, the application to reactive collisions is very straightforward and provides a much simplified approach to obtaining selection rules. PMID:27544099
Kalpakis, Konstantinos; Yang, Shiming; Hu, Peter F; Mackenzie, Colin F; Stansbury, Lynn G; Stein, Deborah M; Scalea, Thomas M
2015-01-01
Permutation entropy is computationally efficient, robust to outliers, and effective to measure complexity of time series. We used this technique to quantify the complexity of continuous vital signs recorded from patients with traumatic brain injury (TBI). Using permutation entropy calculated from early vital signs (initial 10-20% of patient hospital stay time), we built classifiers to predict in-hospital mortality and mobility, measured by 3-month Extended Glasgow Outcome Score (GOSE). Sixty patients with severe TBI produced a skewed dataset that we evaluated for accuracy, sensitivity and specificity. The overall prediction accuracy achieved 91.67% for mortality, and 76.67% for 3-month GOSE in testing datasets, using the leave-one-out cross validation. We also applied Receiver Operating Characteristic analysis to compare classifiers built from different learning methods. Those results support the applicability of permutation entropy in analyzing the dynamic behavior of TBI vital signs for early prediction of mortality and long-term patient outcomes. PMID:25464358
Biard, L; Porcher, R; Resche-Rigon, M
2014-07-30
When analysing multicentre data, it may be of interest to test whether the distribution of the endpoint varies among centres. In a mixed-effect model, testing for such a centre effect consists in testing to zero a random centre effect variance component. It has been shown that the usual asymptotic χ(2) distribution of the likelihood ratio and score statistics under the null does not necessarily hold. In the case of censored data, mixed-effects Cox models have been used to account for random effects, but few works have concentrated on testing to zero the variance component of the random effects. We propose a permutation test, using random permutation of the cluster indices, to test for a centre effect in multilevel censored data. Results from a simulation study indicate that the permutation tests have correct type I error rates, contrary to standard likelihood ratio tests, and are more powerful. The proposed tests are illustrated using data of a multicentre clinical trial of induction therapy in acute myeloid leukaemia patients. PMID:24676752
Directory of Open Access Journals (Sweden)
Anders Eklund
2011-01-01
Full Text Available Parametric statistical methods, such as Z-, t-, and F-values, are traditionally employed in functional magnetic resonance imaging (fMRI for identifying areas in the brain that are active with a certain degree of statistical significance. These parametric methods, however, have two major drawbacks. First, it is assumed that the observed data are Gaussian distributed and independent; assumptions that generally are not valid for fMRI data. Second, the statistical test distribution can be derived theoretically only for very simple linear detection statistics. With nonparametric statistical methods, the two limitations described above can be overcome. The major drawback of non-parametric methods is the computational burden with processing times ranging from hours to days, which so far have made them impractical for routine use in single-subject fMRI analysis. In this work, it is shown how the computational power of cost-efficient graphics processing units (GPUs can be used to speed up random permutation tests. A test with 10000 permutations takes less than a minute, making statistical analysis of advanced detection methods in fMRI practically feasible. To exemplify the permutation-based approach, brain activity maps generated by the general linear model (GLM and canonical correlation analysis (CCA are compared at the same significance level.
An Efficient Constructive Heuristic for Permutation Flow Shops to Minimize Total Flowtime
Institute of Scientific and Technical Information of China (English)
LIXiaoping; WUCheng
2005-01-01
In this paper, FFC (Fast fiowtime-computing) is presented for fiowtime computing in flow shops. The CPU-time of an algorithm for flow shops can be reduced considerably by replacing classical flowtime computing with FFC based on the facts that FFC is faster than the classical one and that flowtime computing of schedules/partial schedules is the main computational burden of most algorithms for flow shops. This is illustrated by modifying RZ, one of the three best existing heuristics(FL, WY and RZ) for flowtime minimization, with FFC in which about half of the CPU-time is saved. An efficient constructive heuristic is proposed for permutation flow shops with flowtime minimization, of which the CPU-time is more than that of RZ but much less than those of FL and WY. Our proposal is compared with FL, WYand RZ in terms of ARPD (Average relative percentage deviation), STD (Standard deviation) and BEST (number of best solutions obtained for a given size of problems). Computational results show that the proposed heuristic outperforms WY and RZ, and also outperforms FL when job-machine ratio is small. However, as the ratio increases, the proposal will finally be outperformed by FL but needs far less CPU-time than FL does.
DLCQ strings, twist fields and one-loop correlators on a permutation orbifold
International Nuclear Information System (INIS)
We investigate some aspects of the relationship between matrix string theory and light-cone string field theory by analysing the correspondence between the two-loop thermal partition function of DLCQ strings in flat space and the integrated two-point correlator of twist fields in a symmetric product orbifold conformal field theory at one-loop order. This is carried out by deriving combinatorial expressions for generic twist field correlation functions in permutation orbifolds using the covering surface method, by deriving the one-loop modification of the twist field interaction vertex, and by relating the two-loop finite temperature DLCQ string theory to the theory of Prym varieties for genus two covers of an elliptic curve. The case of bosonic Z2 orbifolds is worked out explicitly and precise agreement between both amplitudes is found. We use these techniques to derive explicit expressions for Z2 orbifold spin twist field correlation functions in the type II and heterotic string theories
Dornheim, Tobias; Schoof, Tim; Groth, Simon; Filinov, Alexey; Bonitz, Michael
2015-11-01
The uniform electron gas (UEG) at finite temperature is of high current interest due to its key relevance for many applications including dense plasmas and laser excited solids. In particular, density functional theory heavily relies on accurate thermodynamic data for the UEG. Until recently, the only existing first-principle results had been obtained for N = 33 electrons with restricted path integral Monte Carlo (RPIMC), for low to moderate density, r s = r ¯ / a B ≳ 1 . These data have been complemented by configuration path integral Monte Carlo (CPIMC) simulations for rs ≤ 1 that substantially deviate from RPIMC towards smaller rs and low temperature. In this work, we present results from an independent third method—the recently developed permutation blocking path integral Monte Carlo (PB-PIMC) approach [T. Dornheim et al., New J. Phys. 17, 073017 (2015)] which we extend to the UEG. Interestingly, PB-PIMC allows us to perform simulations over the entire density range down to half the Fermi temperature (θ = kBT/EF = 0.5) and, therefore, to compare our results to both aforementioned methods. While we find excellent agreement with CPIMC, where results are available, we observe deviations from RPIMC that are beyond the statistical errors and increase with density.
Structural fluctuation and atom-permutation in transition-metal clusters
International Nuclear Information System (INIS)
The atomic structure and thermodynamic properties of transition-metal clusters containing N atoms are investigated for N=6 and 7 using the method of molecular dynamics, where Gupta's potential taking into account many-body interaction is employed. The caloric curve (total energy-temperature curve) and the structural fluctuations are studied. The 'fluctuating state' is found for N=6 in the region of the temperature near below the melting point, where clusters undergo structural transition from one isomer to others without making any topological change. The fluctuating state differs from the coexistence state in that the former involves no atomic diffusion, and goes to a structural phase transition of the bulk when N is increased. On the other hand, the motion of atom-permutation is found in the low-temperature region of the liquid state, being induced by the cooperative motion of two atoms. It is discussed that such a motion easily occurs along the surface and may be considered to be one of the characteristics of small clusters. The fluctuating state is discussed in relation to the structural fluctuation of gold clusters observed experimentally. (orig.)
CRYPTANALYSIS OF AN IMAGE ENCRYPTION SCHEME WITH A PSEUDORANDOM PERMUTATION AND ITS IMPROVED VERSION
Institute of Scientific and Technical Information of China (English)
Wang Jing; Jiang Guoping; Lin Bing
2012-01-01
Under Kerckhoff principle,this paper discusses the security property of an image encryption scheme with a pseudorandom permutation.Some findings on the security problems of the algorithm are reported in the following:(1) If each row or column of the plain-image matrix is the same,the receiver cannot decrypt correctly.(2) Each plain-text word is correlated with single cipher-text word,but independent of other cipher-text word,which cannot meet the principles of algorithm designdiffusion and confusion.(3) If the cycle numbers β are relatively small,statistics attack can be used to reveal some visual information of any other plain-images encrypted with the same secret key.Considering the above problems,we propose an improved algorithm and then analyze its performance.Theoretical analysis and simulation results show that the improved algorithm can obtain better cryptographic properties,such as statistical characteristics,difference characteristics,and so on.