Small flow rate can supply inwardly migrating shortest-period planets
Directory of Open Access Journals (Sweden)
Taylor S.F.
2013-04-01
Full Text Available The number of exoplanets found with periods as short as one day and less was surprising given how fast these planets had been expected to migrate into the star due to the tides raised on the star by planets at such close distances. It has been seen as improbable that we would find planets in such a small final fraction of their lives [1]. The favored solution has been that the tidal dissipation is much weaker than expected, which would mean that the final infall would be a larger fraction of the planets’ life. We find no reason, however, to exclude the explanation that a small number of planets are continuously sent migrating inwards such that these planets indeed are in the last fraction of their lives. Following the observation that the distribution of medium planets disfavors tidal dissipation being significantly weaker than has been found from observations of binary stars [2], we now show that the numbers of planets in such a “flow” of excess planets migrating inwards is low enough that even depletion of the three-day pileup is a plausible source. Then the shortest period occurrence distribution would be shaped by planets continuously being sent into the star, which may explain the depletion of the pileup in the Kepler field relative to the solar neighborhood [3]. Because Kepler observes above the galactic plan, [3] suggested the Kepler field may include an older population of stars. The tidal dissipation strength in stars due to giant planets may be not greatly weaker than it is in binary stars.
The shortest-known-period star orbiting our Galaxy's supermassive black hole.
Meyer, L; Ghez, A M; Schödel, R; Yelda, S; Boehle, A; Lu, J R; Do, T; Morris, M R; Becklin, E E; Matthews, K
2012-10-05
Stars with short orbital periods at the center of our Galaxy offer a powerful probe of a supermassive black hole. Over the past 17 years, the W. M. Keck Observatory has been used to image the galactic center at the highest angular resolution possible today. By adding to this data set and advancing methodologies, we have detected S0-102, a star orbiting our Galaxy's supermassive black hole with a period of just 11.5 years. S0-102 doubles the number of known stars with full phase coverage and periods of less than 20 years. It thereby provides the opportunity, with future measurements, to resolve degeneracies in the parameters describing the central gravitational potential and to test Einstein's theory of general relativity in an unexplored regime.
Small flow rate can supply inwardly migrating shortest-period planets
Taylor, Stuart F.
2013-01-01
The number of exoplanets found with periods as short as one day and less was surprising given how fast these planets had been expected to migrate into the star due to the tides raised on the star by planets at such close distances. It has been seen as improbable that we would find planets in such a small final fraction of their lives. The favored solution has been that the tidal dissipation is much weaker than expected, which would mean that the final infall would be a larger fraction of the ...
Shortest Paths and Vehicle Routing
DEFF Research Database (Denmark)
Petersen, Bjørn
This thesis presents how to parallelize a shortest path labeling algorithm. It is shown how to handle Chvátal-Gomory rank-1 cuts in a column generation context. A Branch-and-Cut algorithm is given for the Elementary Shortest Paths Problem with Capacity Constraint. A reformulation of the Vehicle...... Routing Problem based on partial paths is presented. Finally, a practical application of finding shortest paths in the telecommunication industry is shown....
An asymmetric shortest queue problem
Adan, I.J.B.F.; Wessels, J.; Zijm, W.H.M.
1989-01-01
In this paper we study a system consisting of two identical servers, each with exponentially distributed service times. Jobs arrive according to a Poisson stream. On arrival a job joins the shortest queue and in case both queues have equal length. he joins queue 1 say with probability q and queue 2
Finding the K shortest hyperpaths using reoptimization
DEFF Research Database (Denmark)
Nielsen, Lars Relund; Pretolani, Daniele; Andersen, Kim Allan
2006-01-01
The shortest hyperpath problem is an extension of the classical shortest path problem and has applications in many different areas. Recently, algorithms for finding the K shortest hyperpaths in a directed hypergraph have been developed by Andersen, Nielsen and Pretolani. In this paper we improve...... the worst-case computational complexity of an algorithm for finding the K shortest hyperpaths in an acyclic hypergraph. This result is obtained by applying new reoptimization techniques for shortest hyperpaths. The algorithm turns out to be quite effective in practice and has already been successfully...
Euclidean shortest paths exact or approximate algorithms
Li, Fajie
2014-01-01
This book reviews algorithms for the exact or approximate solution of shortest-path problems, with a specific focus on a class of algorithms called rubberband algorithms. The coverage includes mathematical proofs for many of the given statements.
Analysis of the asymmetric shortest queue problem
Adan, I.J.B.F.; Wessels, J.; Zijm, W. H M
1991-01-01
In this paper we study a system consisting of two parallel servers with different service rates. Jobs arrive according to a Poisson stream and generate an exponentially distributed workload. On arrival a job joins the shortest queue and in case both queues have equal lengths, he joins the first
Analysis of the shortest queue problem
Adan, I.J.B.F.; Wessels, J.; Zijm, W.H.M.
1989-01-01
In this paper we study a system consisting of two identical servers, each with exponentially distributed service times. Jobs arrive according to a Poisson stream. On arrival a job joins the shortest queue and in case both queues have equal length, he joins either queue with probability ½. We show
Analysis of the symmetric shortest queue problem
Adan, I.J.B.F.; Wessels, J.; Zijm, W.H.M.
1990-01-01
In this paper we study a system consisting of two identical servers, each with exponentially distributed service times. Jobs arrive according to a Poisson stream. On· arrival a job joins the shortest queue and in case both queues have equal lengths, he joins either queue with probability ½. By using
Analysis of the symmetric shortest queue problem
Adan, I.J.B.F.; Wessels, J.; Zijm, W.H.M.
1990-01-01
In this paper we study a system consisting of two identical servers, each with exponentially distributed service times. Jobs arrive according to a Poisson stream. On arrival a job joins the shortest queue and in case both queues have equal lengths, he joins either queue with probability 1/2. By
Analysis of the asymmetric shortest queue problem
Adan, I.J.B.F.; Wessels, J.; Zijm, W.H.M.
1990-01-01
In this paper we study a system consisting of two parallel servers with different service rates. Jobs arrive according to a Poisson stream and generate an exponentially distributed workload. On arrival a job joins the shortest queue and in case both queues have equal lengths, he joins the first
Evaluation of Shortest Paths in Road Network
Directory of Open Access Journals (Sweden)
Farrukh Shehzad
2009-06-01
Full Text Available Optimization is a key factor in almost all the topics of operations research / management science and economics.The road networks can be optimized within different constraints like time, distance, cost and traffic running onthe roads.This study is based on optimization of real road network by means of distances. Two main objectives arepursued in this research: 1 road distances among different routes are composed in detail; 2 two standardalgorithms (Dijkstra and Floyd-Warshall algoritms are applied to optimize/minimize these distances for bothsingle-source and all-pairs shortest path problems.
A NEW APPROACH ON SHORTEST PATH IN FUZZY ENVIRONMENT
A. Nagoorgani; A. Mumtaj Begam
2010-01-01
This paper introduces a new type of fuzzy shortest path network problem using triangular fuzzy number. To find the smallest edge by the fuzzy distance using graded mean integration representation of generalized fuzzy number for every node. Thus the optimum shortest path for the given problem is obtained.
comparative analysis and implementation of dijkstra's shortest path
African Journals Online (AJOL)
user
path problem requires finding a single shortest-path between given vertices s and t; ... Bridge in 1735, [5 – 10]. This problem led to the .... their advancements from new design paradigms, data structures ..... .
Shortest Path Problems in a Stochastic and Dynamic Environment
National Research Council Canada - National Science Library
Cho, Jae
2003-01-01
.... Particularly, we develop a variety of algorithms to solve the expected shortest path problem in addition to techniques for computing the total travel time distribution along a path in the network...
Non interacting control by measurement feedback
Woude, van der J.W.
1987-01-01
In this paper we shall solve the problem of non interacting control by measurement feedback for systems that in addition to a control input and a measurement output have two exogenous inputs and two exogenous outputs. That is, we shall derive necessary and sufficient conditions that can actually be
SPTH3: subroutine for finding shortest sabotage paths
International Nuclear Information System (INIS)
Hulme, B.L.; Holdridge, D.B.
1977-07-01
This document explains how to construct a sabotage graph which models any fixed-site facility and how to use the subroutine SPTH3 to find shortest paths in the graph. The shortest sabotage paths represent physical routes through the site which would allow an adversary to take advantage of the greatest weaknesses in the system of barriers and alarms. The subroutine SPTH3 is a tool with which safeguards designers and analysts can study the relative effects of design changes on the adversary routing problem. In addition to showing how to use SPTH3, this report discusses the methods used to find shortest paths and several implementation details which cause SPTH3 to be extremely efficient
The shortest-path problem analysis and comparison of methods
Ortega-Arranz, Hector; Gonzalez-Escribano, Arturo
2014-01-01
Many applications in different domains need to calculate the shortest-path between two points in a graph. In this paper we describe this shortest path problem in detail, starting with the classic Dijkstra's algorithm and moving to more advanced solutions that are currently applied to road network routing, including the use of heuristics and precomputation techniques. Since several of these improvements involve subtle changes to the search space, it may be difficult to appreciate their benefits in terms of time or space requirements. To make methods more comprehensive and to facilitate their co
Experiments with the auction algorithm for the shortest path problem
DEFF Research Database (Denmark)
Larsen, Jesper; Pedersen, Ib
1999-01-01
The auction approach for the shortest path problem (SPP) as introduced by Bertsekas is tested experimentally. Parallel algorithms using the auction approach are developed and tested. Both the sequential and parallel auction algorithms perform significantly worse than a state-of-the-art Dijkstra-l......-like reference algorithm. Experiments are run on a distributed-memory MIMD class Meiko parallel computer....
Effective caching of shortest paths for location-based services
DEFF Research Database (Denmark)
Jensen, Christian S.; Thomsen, Jeppe Rishede; Yiu, Man Lung
2012-01-01
Web search is ubiquitous in our daily lives. Caching has been extensively used to reduce the computation time of the search engine and reduce the network traffic beyond a proxy server. Another form of web search, known as online shortest path search, is popular due to advances in geo...
Special cases of the quadratic shortest path problem
Sotirov, Renata; Hu, Hao
2017-01-01
The quadratic shortest path problem (QSPP) is the problem of finding a path with prespecified start vertex s and end vertex t in a digraph such that the sum of weights of arcs and the sum of interaction costs over all pairs of arcs on the path is minimized. We first consider a variant of the QSPP
CO2 laser-inscribed low-cost, shortest-period long-period fibre ...
Indian Academy of Sciences (India)
2014-02-07
up. Strain sensitivity of 1.77 dB/mε has been obtained for attenuation band corresponding to the turnaround point mode. TAP operation of LPG facilitates intensity-based detection using simple optical power meter instead.
Ranking shortest paths in Stochastic time-denpendent networks
DEFF Research Database (Denmark)
Nielsen, Lars Relund; Andersen, Kim Allan; Pretolani, Daniele
A substantial amount of research has been devoted to the shortest path problem in networks where travel times are stochastic or (deterministic and) time-dependent. More recently, a growing interest has been attracted by networks that are both stochastic and time-dependent. In these networks, the ...... present a computational comparison of time-adaptive and a priori route choices, pointing out the effect of travel time and cost distributions. The reported results show that, under realistic distributions, our solution methods are effective.......A substantial amount of research has been devoted to the shortest path problem in networks where travel times are stochastic or (deterministic and) time-dependent. More recently, a growing interest has been attracted by networks that are both stochastic and time-dependent. In these networks...
K shortest paths in stochastic time-dependent networks
DEFF Research Database (Denmark)
Nielsen, Lars Relund; Pretolani, Daniele; Andersen, Kim Allan
2004-01-01
A substantial amount of research has been devoted to the shortest path problem in networks where travel times are stochastic or (deterministic and) time-dependent. More recently, a growing interest has been attracted by networks that are both stochastic and time-dependent. In these networks, the ...... present a computational comparison of time-adaptive and a priori route choices, pointing out the effect of travel time and cost distributions. The reported results show that, under realistic distributions, our solution methods are effective.......A substantial amount of research has been devoted to the shortest path problem in networks where travel times are stochastic or (deterministic and) time-dependent. More recently, a growing interest has been attracted by networks that are both stochastic and time-dependent. In these networks...
Structural parcellation of the thalamus using shortest-path tractography
DEFF Research Database (Denmark)
Kasenburg, Niklas; Darkner, Sune; Hahn, Ute
2016-01-01
that parcellation of the thalamus results in p-value maps that are spatially coherent across subjects. Comparing to the state-of-the-art parcellation of Behrens et al. [1], we observe some agreement, but the soft segmentation exhibits better stability for voxels connected to multiple target regions.......We demonstrate how structural parcellation can be implemented using shortest-path tractography, thereby addressing some of the shortcomings of the conventional approaches. In particular, our algorithm quantifies, via p-values, the confidence that a voxel in the parcellated region is connected...... to each cortical target region. Calculation of these statistical measures is derived from a rank-based test on the histogram of tract-based scores from all the shortest paths found between the source voxel and each voxel within the target region. Using data from the Human Connectome Project, we show...
Multiple Object Tracking Using the Shortest Path Faster Association Algorithm
Directory of Open Access Journals (Sweden)
Zhenghao Xi
2014-01-01
Full Text Available To solve the persistently multiple object tracking in cluttered environments, this paper presents a novel tracking association approach based on the shortest path faster algorithm. First, the multiple object tracking is formulated as an integer programming problem of the flow network. Then we relax the integer programming to a standard linear programming problem. Therefore, the global optimum can be quickly obtained using the shortest path faster algorithm. The proposed method avoids the difficulties of integer programming, and it has a lower worst-case complexity than competing methods but better robustness and tracking accuracy in complex environments. Simulation results show that the proposed algorithm takes less time than other state-of-the-art methods and can operate in real time.
Training shortest-path tractography: Automatic learning of spatial priors
DEFF Research Database (Denmark)
Kasenburg, Niklas; Liptrot, Matthew George; Reislev, Nina Linde
2016-01-01
Tractography is the standard tool for automatic delineation of white matter tracts from diffusion weighted images. However, the output of tractography often requires post-processing to remove false positives and ensure a robust delineation of the studied tract, and this demands expert prior...... knowledge. Here we demonstrate how such prior knowledge, or indeed any prior spatial information, can be automatically incorporated into a shortest-path tractography approach to produce more robust results. We describe how such a prior can be automatically generated (learned) from a population, and we...
Shortest triplet clustering: reconstructing large phylogenies using representative sets
Directory of Open Access Journals (Sweden)
Sy Vinh Le
2005-04-01
Full Text Available Abstract Background Understanding the evolutionary relationships among species based on their genetic information is one of the primary objectives in phylogenetic analysis. Reconstructing phylogenies for large data sets is still a challenging task in Bioinformatics. Results We propose a new distance-based clustering method, the shortest triplet clustering algorithm (STC, to reconstruct phylogenies. The main idea is the introduction of a natural definition of so-called k-representative sets. Based on k-representative sets, shortest triplets are reconstructed and serve as building blocks for the STC algorithm to agglomerate sequences for tree reconstruction in O(n2 time for n sequences. Simulations show that STC gives better topological accuracy than other tested methods that also build a first starting tree. STC appears as a very good method to start the tree reconstruction. However, all tested methods give similar results if balanced nearest neighbor interchange (BNNI is applied as a post-processing step. BNNI leads to an improvement in all instances. The program is available at http://www.bi.uni-duesseldorf.de/software/stc/. Conclusion The results demonstrate that the new approach efficiently reconstructs phylogenies for large data sets. We found that BNNI boosts the topological accuracy of all methods including STC, therefore, one should use BNNI as a post-processing step to get better topological accuracy.
An Efficient Shortest Path Routing Algorithm for Directed Indoor Environments
Directory of Open Access Journals (Sweden)
Sultan Alamri
2018-03-01
Full Text Available Routing systems for outdoor space have become the focus of many research works. Such routing systems are based on spatial road networks where moving objects (such as cars are affected by the directed roads and the movement of traffic, which may include traffic jams. Indoor routing, on the other hand, must take into account the features of indoor space such as walls and rooms. In this paper, we take indoor routing in a new direction whereby we consider the features that a building has in common with outdoor spaces. Inside some buildings, there may be directed floors where moving objects must move in a certain direction through directed corridors in order to reach a certain location. For example, on train platforms or in museums, movement in the corridors may be directed. In these directed floor spaces, a routing system enabling a visitor to take the shortest path to a certain location is essential. Therefore, this work proposes a new approach for buildings with directed indoor spaces, where each room can be affected by the density of the moving objects. The proposed system obtains the shortest path between objects or rooms taking into consideration the directed indoor space and the capacity of the objects to move within each room/cell.
DiversePathsJ: diverse shortest paths for bioimage analysis.
Uhlmann, Virginie; Haubold, Carsten; Hamprecht, Fred A; Unser, Michael
2018-02-01
We introduce a formulation for the general task of finding diverse shortest paths between two end-points. Our approach is not linked to a specific biological problem and can be applied to a large variety of images thanks to its generic implementation as a user-friendly ImageJ/Fiji plugin. It relies on the introduction of additional layers in a Viterbi path graph, which requires slight modifications to the standard Viterbi algorithm rules. This layered graph construction allows for the specification of various constraints imposing diversity between solutions. The software allows obtaining a collection of diverse shortest paths under some user-defined constraints through a convenient and user-friendly interface. It can be used alone or be integrated into larger image analysis pipelines. http://bigwww.epfl.ch/algorithms/diversepathsj. michael.unser@epfl.ch or fred.hamprecht@iwr.uni-heidelberg.de. Supplementary data are available at Bioinformatics online. © The Author(s) 2017. Published by Oxford University Press.
External Data Structures for Shortest Path Queries on Planar Digraphs
DEFF Research Database (Denmark)
Arge, Lars; Toma, Laura
2005-01-01
In this paper we present space-query trade-offs for external memory data structures that answer shortest path queries on planar directed graphs. For any S = Ω(N 1 + ε) and S = O(N2/B), our main result is a family of structures that use S space and answer queries in O(N2/ S B) I/Os, thus obtaining...... optimal space-query product O(N2/B). An S space structure can be constructed in O(√S · sort(N)) I/Os, where sort(N) is the number of I/Os needed to sort N elements, B is the disk block size, and N is the size of the graph....
Particle swarm optimization for determining shortest distance to voltage collapse
Energy Technology Data Exchange (ETDEWEB)
Arya, L.D.; Choube, S.C. [Electrical Engineering Department, S.G.S.I.T.S. Indore, MP 452 003 (India); Shrivastava, M. [Electrical Engineering Department, Government Engineering College Ujjain, MP 456 010 (India); Kothari, D.P. [Centre for Energy Studies, Indian Institute of Technology, Delhi (India)
2007-12-15
This paper describes an algorithm for computing shortest distance to voltage collapse or determination of CSNBP using PSO technique. A direction along CSNBP gives conservative results from voltage security view point. This information is useful to the operator to steer the system away from this point by taking corrective actions. The distance to a closest bifurcation is a minimum of the loadability given a slack bus or participation factors for increasing generation as the load increases. CSNBP determination has been formulated as an optimization problem to be used in PSO technique. PSO is a new evolutionary algorithm (EA) which is population based inspired by the social behavior of animals such as fish schooling and birds flocking. It can handle optimization problems with any complexity since mechanization is simple with few parameters to be tuned. The developed algorithm has been implemented on two standard test systems. (author)
Calculating Graph Algorithms for Dominance and Shortest Path
DEFF Research Database (Denmark)
Sergey, Ilya; Midtgaard, Jan; Clarke, Dave
2012-01-01
We calculate two iterative, polynomial-time graph algorithms from the literature: a dominance algorithm and an algorithm for the single-source shortest path problem. Both algorithms are calculated directly from the definition of the properties by fixed-point fusion of (1) a least fixed point...... expressing all finite paths through a directed graph and (2) Galois connections that capture dominance and path length. The approach illustrates that reasoning in the style of fixed-point calculus extends gracefully to the domain of graph algorithms. We thereby bridge common practice from the school...... of program calculation with common practice from the school of static program analysis, and build a novel view on iterative graph algorithms as instances of abstract interpretation...
An Optimal Non-Interactive Message Authentication Protocol
Pasini, Sylvain; Vaudenay, Serge
2006-01-01
Vaudenay recently proposed a message authentication protocol which is interactive and based on short authenticated strings (SAS). We study here SAS-based non-interactive message authentication protocols (NIMAP). We start by the analysis of two popular non-interactive message authentication protocols. The first one is based on a collision-resistant hash function and was presented by Balfanz et al. The second protocol is based on a universal hash function family and was proposed by Gehrmann, Mi...
Extended shortest path selection for package routing of complex networks
Ye, Fan; Zhang, Lei; Wang, Bing-Hong; Liu, Lu; Zhang, Xing-Yi
The routing strategy plays a very important role in complex networks such as Internet system and Peer-to-Peer networks. However, most of the previous work concentrates only on the path selection, e.g. Flooding and Random Walk, or finding the shortest path (SP) and rarely considering the local load information such as SP and Distance Vector Routing. Flow-based Routing mainly considers load balance and still cannot achieve best optimization. Thus, in this paper, we propose a novel dynamic routing strategy on complex network by incorporating the local load information into SP algorithm to enhance the traffic flow routing optimization. It was found that the flow in a network is greatly affected by the waiting time of the network, so we should not consider only choosing optimized path for package transformation but also consider node congestion. As a result, the packages should be transmitted with a global optimized path with smaller congestion and relatively short distance. Analysis work and simulation experiments show that the proposed algorithm can largely enhance the network flow with the maximum throughput within an acceptable calculating time. The detailed analysis of the algorithm will also be provided for explaining the efficiency.
Solving fuzzy shortest path problem by genetic algorithm
Syarif, A.; Muludi, K.; Adrian, R.; Gen, M.
2018-03-01
Shortest Path Problem (SPP) is known as one of well-studied fields in the area Operations Research and Mathematical Optimization. It has been applied for many engineering and management designs. The objective is usually to determine path(s) in the network with minimum total cost or traveling time. In the past, the cost value for each arc was usually assigned or estimated as a deteministic value. For some specific real world applications, however, it is often difficult to determine the cost value properly. One way of handling such uncertainty in decision making is by introducing fuzzy approach. With this situation, it will become difficult to solve the problem optimally. This paper presents the investigations on the application of Genetic Algorithm (GA) to a new SPP model in which the cost values are represented as Triangular Fuzzy Number (TFN). We adopts the concept of ranking fuzzy numbers to determine how good the solutions. Here, by giving his/her degree value, the decision maker can determine the range of objective value. This would be very valuable for decision support system in the real world applications.Simulation experiments were carried out by modifying several test problems with 10-25 nodes. It is noted that the proposed approach is capable attaining a good solution with different degree of optimism for the tested problems.
An Application of Multi-Criteria Shortest Path to a Customizable Hex-Map Environment
2015-03-26
47 Appendix A. Shortest Path Code ( VBA ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Appendix B. Quad Chart...efficient shortest path algorithm into the modeling environment, namely Excel VBA . While various algorithms offer the potential for more efficiency in...graphical interface is extremely intuitive and easily accessible to a user with no prior knowledge of the system. Since the Metz model is based on the
Matrix-geometric analysis of the shortest queue problem with threshold jockeying
Zijm, Willem H.M.; Adan, I.J.B.F.; Wessels, J.
1993-01-01
In this paper we study a system consisting of c parallel servers with possibly different service rates. Jobs arrive according to a Poisson stream and generate an exponentially distributed workload. An arriving job joins the shortest queue, where in case of multiple shortest queues, one of these
The time-varying shortest path problem with fuzzy transit costs and speedup
Directory of Open Access Journals (Sweden)
Rezapour Hassan
2016-08-01
Full Text Available In this paper, we focus on the time-varying shortest path problem, where the transit costs are fuzzy numbers. Moreover, we consider this problem in which the transit time can be shortened at a fuzzy speedup cost. Speedup may also be a better decision to find the shortest path from a source vertex to a specified vertex.
External Memory Algorithms for Diameter and All-Pair Shortest-Paths on Sparse Graphs
DEFF Research Database (Denmark)
Arge, Lars; Meyer, Ulrich; Toma, Laura
2004-01-01
We present several new external-memory algorithms for finding all-pairs shortest paths in a V -node, Eedge undirected graph. For all-pairs shortest paths and diameter in unweighted undirected graphs we present cache-oblivious algorithms with O(V · E B logM B E B) I/Os, where B is the block-size a...
International Nuclear Information System (INIS)
Gianninas, A.; Kilic, Mukremin; Dufour, P.; Bergeron, P.; Brown, Warren R.; Hermes, J. J.
2014-01-01
We present a detailed spectroscopic analysis of 61 low-mass white dwarfs and provide precise atmospheric parameters, masses, and updated binary system parameters based on our new model atmosphere grids and the most recent evolutionary model calculations. For the first time, we measure systematic abundances of He, Ca, and Mg for metal-rich, extremely low mass white dwarfs and examine the distribution of these abundances as a function of effective temperature and mass. Based on our preliminary results, we discuss the possibility that shell flashes may be responsible for the presence of the observed He and metals. We compare stellar radii derived from our spectroscopic analysis to model-independent measurements and find good agreement except for white dwarfs with T eff ≲ 10,000 K. We also calculate the expected gravitational wave strain for each system and discuss their significance to the eLISA space-borne gravitational wave observatory. Finally, we provide an update on the instability strip of extremely low mass white dwarf pulsators.
Energy Technology Data Exchange (ETDEWEB)
Gianninas, A.; Kilic, Mukremin [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 West Brooks Street, Norman, OK 73019 (United States); Dufour, P.; Bergeron, P. [Département de Physique, Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, Québec H3C 3J7 (Canada); Brown, Warren R. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Hermes, J. J., E-mail: alexg@nhn.ou.edu [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)
2014-10-10
We present a detailed spectroscopic analysis of 61 low-mass white dwarfs and provide precise atmospheric parameters, masses, and updated binary system parameters based on our new model atmosphere grids and the most recent evolutionary model calculations. For the first time, we measure systematic abundances of He, Ca, and Mg for metal-rich, extremely low mass white dwarfs and examine the distribution of these abundances as a function of effective temperature and mass. Based on our preliminary results, we discuss the possibility that shell flashes may be responsible for the presence of the observed He and metals. We compare stellar radii derived from our spectroscopic analysis to model-independent measurements and find good agreement except for white dwarfs with T {sub eff} ≲ 10,000 K. We also calculate the expected gravitational wave strain for each system and discuss their significance to the eLISA space-borne gravitational wave observatory. Finally, we provide an update on the instability strip of extremely low mass white dwarf pulsators.
VLBI observations of the shortest orbital period black hole binary, MAXI J1659-152
Paragi, Z.; van der Horst, A.J.; Belloni, T.; Miller-Jones, J.C.A.; Linford, J.; Taylor, G.; Yang, J.; Garrett, M.A.; Granot, J.; Kouveliotou, C.; Kuulkers, E.; Wijers, R.A.M.J.
2013-01-01
The X-ray transient MAXI J1659−152 was discovered by Swift/Burst Alert Telescope and it was initially identified as a gamma-ray burst. Soon its Galactic origin and binary nature were established. There exists a wealth of multiwavelength monitoring data for this source, providing a great coverage of
MAXI J1659-152: The shortest orbital period black-hole transient in outburst
DEFF Research Database (Denmark)
Kuulkers, E.; Kouveliotou, C.; Belloni, T.
2013-01-01
MAXI J1659−152 is a bright X-ray transient black-hole candidate binary system discovered in September 2010. We report here on MAXI, RXTE, Swift, and XMM-Newton observations during its 2010/2011 outburst. We find that during the first one and a half week of the outburst the X-ray light curves disp...
MAXI J1659-152: the shortest orbital period black-hole binary
DEFF Research Database (Denmark)
Kuulkers, E.; Kouveliotou, C.; van der Horst, A. J.
Following the detection of a bright new X-ray source, MAXI J1659-152, a series of observations was triggered with almost all currently flying high-energy missions. We report here on XMM-Newton, INTEGRAL and RXTE observations during the early phase of the X-ray outburst of this transient black-hol...
Public-Key Encryption with Non-interactive Opening
DEFF Research Database (Denmark)
Damgård, Ivan Bjerre; Hofheinz, Dennis; Kiltz, Eike
2008-01-01
We formally define the primitive of public-key encryption with non-interactive opening (PKENO), where the receiver of a ciphertext C can, convincingly and without interaction, reveal what the result was of decrypting C, without compromising the scheme’s security. This has numerous applications...
Algorithm for shortest path search in Geographic Information Systems by using reduced graphs.
Rodríguez-Puente, Rafael; Lazo-Cortés, Manuel S
2013-01-01
The use of Geographic Information Systems has increased considerably since the eighties and nineties. As one of their most demanding applications we can mention shortest paths search. Several studies about shortest path search show the feasibility of using graphs for this purpose. Dijkstra's algorithm is one of the classic shortest path search algorithms. This algorithm is not well suited for shortest path search in large graphs. This is the reason why various modifications to Dijkstra's algorithm have been proposed by several authors using heuristics to reduce the run time of shortest path search. One of the most used heuristic algorithms is the A* algorithm, the main goal is to reduce the run time by reducing the search space. This article proposes a modification of Dijkstra's shortest path search algorithm in reduced graphs. It shows that the cost of the path found in this work, is equal to the cost of the path found using Dijkstra's algorithm in the original graph. The results of finding the shortest path, applying the proposed algorithm, Dijkstra's algorithm and A* algorithm, are compared. This comparison shows that, by applying the approach proposed, it is possible to obtain the optimal path in a similar or even in less time than when using heuristic algorithms.
Directory of Open Access Journals (Sweden)
Mario Miler
2014-02-01
Full Text Available In the field of geoinformation and transportation science, the shortest path is calculated on graph data mostly found in road and transportation networks. This data is often stored in various database systems. Many applications dealing with transportation network require calculation of the shortest path. The objective of this research is to compare the performance of Dijkstra shortest path calculation in PostgreSQL (with pgRouting and Neo4j graph database for the purpose of determining if there is any difference regarding the speed of the calculation. Benchmarking was done on commodity hardware using OpenStreetMap road network. The first assumption is that Neo4j graph database would be well suited for the shortest path calculation on transportation networks but this does not come without some cost. Memory proved to be an issue in Neo4j setup when dealing with larger transportation networks.
Logic of non-interacting programs and reactive systems
Shelekhov, Vladimir; Tumurov, Erdem
2012-01-01
The notion of a program logic is introduced to denote a set of predicates which are true in different program points. The program logic can be easily constructed for different kinds of statements of an imperative or a functional language with data types except pointers. For a non-interacting program, a total correctness formula based on the program logic is defined. The rules of program correctness proof have been developed for proving the statements of various kinds. For a reactive system, t...
Bakar, Sumarni Abu; Ibrahim, Milbah
2017-08-01
The shortest path problem is a popular problem in graph theory. It is about finding a path with minimum length between a specified pair of vertices. In any network the weight of each edge is usually represented in a form of crisp real number and subsequently the weight is used in the calculation of shortest path problem using deterministic algorithms. However, due to failure, uncertainty is always encountered in practice whereby the weight of edge of the network is uncertain and imprecise. In this paper, a modified algorithm which utilized heuristic shortest path method and fuzzy approach is proposed for solving a network with imprecise arc length. Here, interval number and triangular fuzzy number in representing arc length of the network are considered. The modified algorithm is then applied to a specific example of the Travelling Salesman Problem (TSP). Total shortest distance obtained from this algorithm is then compared with the total distance obtained from traditional nearest neighbour heuristic algorithm. The result shows that the modified algorithm can provide not only on the sequence of visited cities which shown to be similar with traditional approach but it also provides a good measurement of total shortest distance which is lesser as compared to the total shortest distance calculated using traditional approach. Hence, this research could contribute to the enrichment of methods used in solving TSP.
Morita, Yusuke; Ogihara, Naomichi; Kanai, Takashi; Suzuki, Hiromasa
2013-08-01
Three-dimensional geometric morphometric techniques have been widely used in quantitative comparisons of craniofacial morphology in humans and nonhuman primates. However, few anatomical landmarks can actually be defined on the neurocranium. In this study, an alternative method is proposed for defining semi-landmarks on neurocranial surfaces for use in detailed analysis of cranial shape. Specifically, midsagittal, nuchal, and temporal lines were approximated using Bezier curves and equally spaced points along each of the curves were defined as semi-landmarks. The shortest paths connecting pairs of anatomical landmarks as well as semi-landmarks were then calculated in order to represent the surface morphology between landmarks using equally spaced points along the paths. To evaluate the efficacy of this method, the previously outlined technique was used in morphological analysis of sexual dimorphism in modern Japanese crania. The study sample comprised 22 specimens that were used to generate 110 anatomical semi-landmarks, which were used in geometric morphometric analysis. Although variations due to sexual dimorphism in human crania are very small, differences could be identified using the proposed landmark placement, which demonstrated the efficacy of the proposed method. Copyright © 2013 Wiley Periodicals, Inc.
The circumnuclear environment of nearby non-interacting Seyfert galaxies
International Nuclear Information System (INIS)
Pogge, R.W.
1988-01-01
An investigation into the physical conditions prevailing in the regions immediately surrounding the active nuclei in 20 nearby, non-interacting Seyfert galaxies is reported. CCD interference-band images isolating the bright emission lines of Hα + [N II] λλ6548, 6583 and [O III] λ5007 have been obtained to search for spatially extended circumnuclear emission regions. Long-slit, low resolution spectrophotometry of interesting cases was used to probe the ionization state of the extended emission regions. For comparison, a CCD Hα + [N II] interference-band imaging survey of a statistically significant sample of 91 bright non-Seyfert spiral galaxies meeting the same non-interaction criteria has been carried out. Only three out of nine Seyfert 1s have spatially extended ionized gas regions compared with eight out of eleven Seyfert 2s. Enhanced circumnuclear star formation is uncommon to both Seyfert 1s and 2s. Extended emission in Seyfert 1s has essentially the same morphology in both Hα + [N II] and [O III] emission. In the Seyfert 2s, the Hα + [N II] and [O III] images show different extended emission morphologies. The [O III] emission regions appear as either one- or two-sided structures, four of which are resolved into two distinct cones of high-ionization gas emanating from the active nucleus. The morphology and ionization of these regions suggest collimation of the nuclear ionizing radiation field. The 91 non-interacting non-Seyfert spiral galaxies exhibit a rich variety of nuclear and circumnuclear emission-line structures ranging from no emission detected to bright stellar nuclei with complicated circumnuclear emission regions extending for many kiloparsecs
Prograph Based Analysis of Single Source Shortest Path Problem with Few Distinct Positive Lengths
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B. Bhowmik
2011-08-01
Full Text Available In this paper we propose an experimental study model S3P2 of a fast fully dynamic programming algorithm design technique in finite directed graphs with few distinct nonnegative real edge weights. The Bellman-Ford’s approach for shortest path problems has come out in various implementations. In this paper the approach once again is re-investigated with adjacency matrix selection in associate least running time. The model tests proposed algorithm against arbitrarily but positive valued weighted digraphs introducing notion of Prograph that speeds up finding the shortest path over previous implementations. Our experiments have established abstract results with the intention that the proposed algorithm can consistently dominate other existing algorithms for Single Source Shortest Path Problems. A comparison study is also shown among Dijkstra’s algorithm, Bellman-Ford algorithm, and our algorithm.
Finding Shortest Paths on Terrains by Killing Two Birds with One Stone
DEFF Research Database (Denmark)
Kaul, Manohar; Wong, Raymond Chi-Wing; Yang, Bin
2013-01-01
With the increasing availability of terrain data, e.g., from aerial laser scans, the management of such data is attracting increasing at- tention in both industry and academia. In particular, spatial queries, e.g., k -nearest neighbor and reverse nearest neighbor queries, in Euclidean and spatial...... network spaces are being extended to ter- rains. Such queries all rely on an important operation, that of finding shortest surface distances. However, shortest surface dis- tance computation is very time consuming. We propose techniques that enable efficient computation of lower and upper bounds...... of the shortest surface distance, which enable faster query processing by eliminating expensive distance computations. Empirical studies show that our bounds are much tighter than the best-known bounds in many cases and that they enable speedups of up to 43 times for some well-known spatial querie...
Shortest loops are pacemakers in random networks of electrically coupled axons
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Nikita eVladimirov
2012-04-01
Full Text Available High-frequency oscillations (HFOs are an important part of brain activity in health and disease. However, their origins remain obscure and controversial. One possible mechanism depends on the presence of sparsely distributed gap junctions that electrically couple the axons of principal cells. A plexus of electrically coupled axons is modeled as a random network with bidirectional connections between its nodes. Under certain conditions the network can demonstrate one of two types of oscillatory activity. Type I oscillations (100-200 Hz are predicted to be caused by spontaneously spiking axons in a network with strong (high-conductance gap junctions. Type II oscillations (200-300 Hz require no spontaneous spiking and relatively weak (low-conductance gap junctions, across which spike propagation failures occur. The type II oscillations are reentrant and self-sustained. Here we examine what determines the frequency of type II oscillations. Using simulations we show that the distribution of loop lengths is the key factor for determining frequency in type II network oscillations. We first analyze spike failure between two electrically coupled cells using a model of anatomically reconstructed CA1 pyramidal neuron. Then network oscillations are studied by a cellular automaton model with random network connectivity, in which we control loop statistics. We show that oscillation periods can be predicted from the network's loop statistics. The shortest loop, around which a spike can travel, is the most likely pacemaker candidate.The principle of one loop as a pacemaker is remarkable, because random networks contain a large number of loops juxtaposed and superimposed, and their number rapidly grows with network size. This principle allows us to predict the frequency of oscillations from network connectivity and visa versa. We finally propose that type I oscillations may correspond to ripples, while type II oscillations correspond to so-called fast ripples.
Kröger, Martin
2005-06-01
disconnected path, including obstacles, if present) by first replacing each polymer contour by a line with a number of 'kinks' (beads, nodes) and 'segments' (edges). To obtain primitive paths, defined to be uncrossable by any other objects (neighboring primitive paths, line or point obstacles), the algorithm minimizes the length of all primitive paths consecutively, until a final minimum Euclidean length of the SP is reached. Fast geometric operations rather than dynamical methods are used to minimize the contour lengths of the primitive paths. Neighbor lists are used to keep track of potentially intersecting segments of other chains. Periodic boundary conditions are employed. A finite small line thickness is used in order to make sure that entanglements are not 'lost' due to finite precision of representation of numbers. Restrictions on the complexity of the problem: For a single chain embedded within fixed line or point obstacles, the algorithm returns the exact SP. For more complex problems, the algorithm returns a locally optimal SP. Except for exotic, probably rare, configurations it turns out that different locally optimal SPs possess quite an identical number of nodes. In general, the problem constructing the SP is known to be NP-hard [J.S.B. Mitchell, Geometric shortest paths and network optimization, in: J.-R. Sack, J. Urrutia (Eds.), Handbook of Computational Geometry, Elsevier, Amsterdam, 2000, pp. 633-701], and we offer a solution which should suffice to analyze physical problems, and gives an estimate about the precision and uniqueness of the result (from a standard deviation by varying the parameter: cyclicswitch). The program is NOT restricted to handle systems for which segment lengths of the SP exceed half the box size. Typical running time: Typical running times are approximately two orders of magnitude shorter compared with the ones needed for a corresponding molecular dynamics approach, and scale mostly linearly with system size. We provide a benchmark
The Resource constrained shortest path problem implemented in a lazy functional language
Hartel, Pieter H.; Glaser, Hugh
The resource constrained shortest path problem is an NP-hard problem for which many ingenious algorithms have been developed. These algorithms are usually implemented in Fortran or another imperative programming language. We have implemented some of the simpler algorithms in a lazy functional
Theilmann, Florian
2017-01-01
The classical "brachistochrone" problem asks for the path on which a mobile point M just driven by its own gravity will travel in the shortest possible time between two given points "A" and "B." The resulting curve, the cycloid, will also be the "tautochrone" curve, i.e. the travelling time of the mobile…
van Houtum, Geert-Jan; Adan, I.J.B.F.; Wessels, J.; Zijm, Willem H.M.
In this paper we study a production system consisting of a group of parallel machines producing multiple job types. Each machine has its own queue and it can process a restricted set of job types only. On arrival a job joins the shortest queue among all queues capable of serving that job. Under the
Dessing, D.; Vries, S.I. de; Hegeman, G.; Verhagen, E.; Mechelen, W. van; Pierik, F.H.
2016-01-01
Background: The purpose of this study is to increase our understanding of environmental correlates that are associated with route choice during active transportation to school (ATS) by comparing characteristics of actual walking and cycling routes between home and school with the shortest possible
Analysis of the asymmetric shortest queue problem : part 2: numerical analysis
Adan, I.J.B.F.; Wessels, J.; Zijm, W.H.M.
1990-01-01
In this paper we study a system consisting of two parallel servers with different service rates. Jobs arrive according to a Poisson stream and generate an exponentially distributed workload. On arrival a job joins the shortest queue and in case both queues have equal lengths, he joins the first
Analysis of the asymmetric shortest queue problem : Part 1: theoretical analysis
Adan, I.J.B.F.; Wessels, J.; Zijm, W.H.M.
1990-01-01
In this paper we study a system consisting of two parallel servers with different service rates. Jobs arrive according to a Poisson stream and generate an exponentially distributed workload. On arrival a job joins the shortest queue and in case both queues have equal lengths. be joins the first
Directory of Open Access Journals (Sweden)
Longxiang Li
Full Text Available Effective assessments of air-pollution exposure depend on the ability to accurately predict pollutant concentrations at unmonitored locations, which can be achieved through spatial interpolation. However, most interpolation approaches currently in use are based on the Euclidean distance, which cannot account for the complex nonlinear features displayed by air-pollution distributions in the wind-field. In this study, an interpolation method based on the shortest path distance is developed to characterize the impact of complex urban wind-field on the distribution of the particulate matter concentration. In this method, the wind-field is incorporated by first interpolating the observed wind-field from a meteorological-station network, then using this continuous wind-field to construct a cost surface based on Gaussian dispersion model and calculating the shortest wind-field path distances between locations, and finally replacing the Euclidean distances typically used in Inverse Distance Weighting (IDW with the shortest wind-field path distances. This proposed methodology is used to generate daily and hourly estimation surfaces for the particulate matter concentration in the urban area of Beijing in May 2013. This study demonstrates that wind-fields can be incorporated into an interpolation framework using the shortest wind-field path distance, which leads to a remarkable improvement in both the prediction accuracy and the visual reproduction of the wind-flow effect, both of which are of great importance for the assessment of the effects of pollutants on human health.
MARKETING DATABASES – THE SHORTEST WAY TO CLIENT’S HEART
Directory of Open Access Journals (Sweden)
Popa Adela Laura
2008-05-01
Full Text Available The aim of this paper is to present the potential which could be offered by managing databases in direct marketing through gathering the information that could offer the shortest and efficient way to the clients needs. The paper includes the necessary steps to make this activity a real success
Degree distribution of shortest path trees and bias of network sampling algorithms
Bhamidi, S.; Goodman, J.A.; Hofstad, van der R.W.; Komjáthy, J.
2013-01-01
In this article, we explicitly derive the limiting distribution of the degree distribution of the shortest path tree from a single source on various random network models with edge weights. We determine the power-law exponent of the degree distribution of this tree and compare it to the degree
Degree distribution of shortest path trees and bias of network sampling algorithms
Bhamidi, S.; Goodman, J.A.; Hofstad, van der R.W.; Komjáthy, J.
2015-01-01
In this article, we explicitly derive the limiting degree distribution of the shortest path tree from a single source on various random network models with edge weights. We determine the asymptotics of the degree distribution for large degrees of this tree and compare it to the degree distribution
Directory of Open Access Journals (Sweden)
J R Managbanag
Full Text Available BACKGROUND: Identification of genes that modulate longevity is a major focus of aging-related research and an area of intense public interest. In addition to facilitating an improved understanding of the basic mechanisms of aging, such genes represent potential targets for therapeutic intervention in multiple age-associated diseases, including cancer, heart disease, diabetes, and neurodegenerative disorders. To date, however, targeted efforts at identifying longevity-associated genes have been limited by a lack of predictive power, and useful algorithms for candidate gene-identification have also been lacking. METHODOLOGY/PRINCIPAL FINDINGS: We have utilized a shortest-path network analysis to identify novel genes that modulate longevity in Saccharomyces cerevisiae. Based on a set of previously reported genes associated with increased life span, we applied a shortest-path network algorithm to a pre-existing protein-protein interaction dataset in order to construct a shortest-path longevity network. To validate this network, the replicative aging potential of 88 single-gene deletion strains corresponding to predicted components of the shortest-path longevity network was determined. Here we report that the single-gene deletion strains identified by our shortest-path longevity analysis are significantly enriched for mutations conferring either increased or decreased replicative life span, relative to a randomly selected set of 564 single-gene deletion strains or to the current data set available for the entire haploid deletion collection. Further, we report the identification of previously unknown longevity genes, several of which function in a conserved longevity pathway believed to mediate life span extension in response to dietary restriction. CONCLUSIONS/SIGNIFICANCE: This work demonstrates that shortest-path network analysis is a useful approach toward identifying genetic determinants of longevity and represents the first application of
ESHOPPS: A COMPUTATIONAL TOOL TO AID THE TEACHING OF SHORTEST PATH ALGORITHMS
Directory of Open Access Journals (Sweden)
S. J. de A. LIMA
2015-07-01
Full Text Available The development of a computational tool called EShoPPS – Environment for Shortest Path Problem Solving, which is used to assist students in understanding the working of Dijkstra, Greedy search and A*(star algorithms is presented in this paper. Such algorithms are commonly taught in graduate and undergraduate courses of Engineering and Informatics and are used for solving many optimization problems that can be characterized as Shortest Path Problem. The EShoPPS is an interactive tool that allows students to create a graph representing the problem and also helps in developing their knowledge of each specific algorithm. Experiments performed with 155 students of undergraduate and graduate courses such as Industrial Engineering, Computer Science and Information Systems have shown that by using the EShoPPS tool students were able to improve their interpretation of investigated algorithms.
Establishment Of The Shortest Route A Prototype For Facilitation In Road Network
Directory of Open Access Journals (Sweden)
Sumaira Yousuf Khan
2015-08-01
Full Text Available Calculating the shortest path between two locations in a road network is a significant problem in network analysis. Roads play a pivotal role in day to day activities of masses live in places and areas. They travel for various purposes that are to study to work to shop and to supply their goods and the like from one place to another place. Even in this modern era roads remain one of the mediums used most frequently for travel and transportation. Being ignorant of the shortest routes people sometimes have to travel long distances consume extra precious time money and bare undesirable mental stress. Karachi is the second most populated and the seventh biggest city of the world. It is the central place of Pakistan which is famous for industry banking trade and economic activity and there are places which frequently visit by the inhabitants for their miscellaneous requirements. Federal Board of Revenue FBR is one of the departments that deal with taxation and revenue generation in the country. A common man residing near or distant areas often visit FBR to settle their business property and tax related issues. In order to facilitate the masses an effort is being made to develop a prototype based on Dijkstras Algorithm DA to establish a shortest route that will help individuals in navigation and subsequently alleviate difficulties faced by them in travelling road networks.
The Shortest Path Problems in Battery-Electric Vehicle Dispatching with Battery Renewal
Directory of Open Access Journals (Sweden)
Minfang Huang
2016-06-01
Full Text Available Electric vehicles play a key role for developing an eco-sustainable transport system. One critical component of an electric vehicle is its battery, which can be quickly charged or exchanged before it runs out. The problem of electric vehicle dispatching falls into the category of the shortest path problem with resource renewal. In this paper, we study the shortest path problems in (1 electric transit bus scheduling and (2 electric truck routing with time windows. In these applications, a fully-charged battery allows running a limited operational distance, and the battery before depletion needs to be quickly charged or exchanged with a fully-charged one at a battery management facility. The limited distance and battery renewal result in a shortest path problem with resource renewal. We develop a label-correcting algorithm with state space relaxation to find optimal solutions. In the computational experiments, real-world road geometry data are used to generate realistic travel distances, and other types of data are obtained from the real world or randomly generated. The computational results show that the label-correcting algorithm performs very well.
A new approach to shortest paths on networks based on the quantum bosonic mechanism
Energy Technology Data Exchange (ETDEWEB)
Jiang Xin; Wang Hailong; Tang Shaoting; Ma Lili; Zhang Zhanli; Zheng Zhiming, E-mail: jiangxin@ss.buaa.edu.cn [Key Laboratory of Mathematics, Informatics and Behavioral Semantics, Ministry of Education, Beijing University of Aeronautics and Astronautics, 100191 Beijing (China)
2011-01-15
This paper presents quantum bosonic shortest path searching (QBSPS), a natural, practical and highly heuristic physical algorithm for reasoning about the recognition of network structure via quantum dynamics. QBSPS is based on an Anderson-like itinerant bosonic system in which a boson's Green function is used as a navigation pointer for one to accurately approach the terminals. QBSPS is demonstrated by rigorous mathematical and physical proofs and plenty of simulations, showing how it can be used as a greedy routing to seek the shortest path between different locations. In methodology, it is an interesting and new algorithm rooted in the quantum mechanism other than combinatorics. In practice, for the all-pairs shortest-path problem in a random scale-free network with N vertices, QBSPS runs in O({mu}(N) ln ln N) time. In application, we suggest that the corresponding experimental realizations are feasible by considering path searching in quantum optical communication networks; in this situation, the method performs a pure local search on networks without requiring the global structure that is necessary for current graph algorithms.
Finding shortest non-trivial cycles in directed graphs on surfaces
Directory of Open Access Journals (Sweden)
Sergio Cabello
2016-04-01
Full Text Available Let $D$ be a weighted directed graph cellularly embedded in a surface of genus $g$, orientable or not, possibly with boundary. We describe algorithms to compute shortest non-contractible and shortest surface non-separating cycles in $D$, generalizing previous results that dealt with undirected graphs.Our first algorithm computes such cycles in $O(n^2\\log n$ time, where $n$ is the total number of vertices and edges of $D$, thus matching the complexity of the best general algorithm in the undirected case. It revisits and extends Thomassen's 3-path condition; the technique applies to other families of cycles as well.We also provide more efficient algorithms in special cases, such as graphs with small genus or bounded treewidth, using a divide-and-conquer technique that simplifies the graph while preserving the topological properties of its cycles. Finally, we give an efficient output-sensitive algorithm, whose running time depends on the length of the shortest non-contractible or non-separating cycle.
Directory of Open Access Journals (Sweden)
Jean Chamberlain Chedjou
2015-01-01
Full Text Available This paper develops a flexible analytical concept for robust shortest path detection in dynamically reconfigurable graphs. The concept is expressed by a mathematical model representing the shortest path problem solver. The proposed mathematical model is characterized by three fundamental parameters expressing (a the graph topology (through the “incidence matrix”, (b the edge weights (with dynamic external weights’ setting capability, and (c the dynamic reconfigurability through external input(s of the source-destination nodes pair. In order to demonstrate the universality of the developed concept, a general algorithm is proposed to determine the three fundamental parameters (of the mathematical model developed for all types of graphs regardless of their topology, magnitude, and size. It is demonstrated that the main advantage of the developed concept is that arc costs, the origin-destination pair setting, and the graph topology are dynamically provided by external commands, which are inputs of the shortest path solver model. This enables high flexibility and full reconfigurability of the developed concept, without any retraining need. To validate the concept developed, benchmarking is performed leading to a comparison of its performance with the performances of two well-known concepts based on neural networks.
Efficient evaluation of shortest travel-time path queries through spatial mashups
Zhang, Detian; Chow, Chi-Yin; Liu, An; Zhang, Xiangliang; Ding, Qingzhu; Li, Qing
2017-01-01
In the real world, the route/path with the shortest travel time in a road network is more meaningful than that with the shortest network distance for location-based services (LBS). However, not every LBS provider has adequate resources to compute/estimate travel time for routes by themselves. A cost-effective way for LBS providers to estimate travel time for routes is to issue external route requests to Web mapping services (e.g., Google Maps, Bing Maps, and MapQuest Maps). Due to the high cost of processing such external route requests and the usage limits of Web mapping services, we take the advantage of direction sharing, parallel requesting and waypoints supported by Web mapping services to reduce the number of external route requests and the query response time for shortest travel-time route queries in this paper. We first give the definition of sharing ability to reflect the possibility of sharing the direction information of a route with others, and find out the queries that their query routes are independent with each other for parallel processing. Then, we model the problem of selecting the optimal waypoints for an external route request as finding the longest simple path in a weighted complete digraph. As it is a MAX SNP-hard problem, we propose a greedy algorithm with performance guarantee to find the best set of waypoints in an external route request. We evaluate the performance of our approach using a real Web mapping service, a real road network, real and synthetic data sets. Experimental results show the efficiency, scalability, and applicability of our approach.
Efficient evaluation of shortest travel-time path queries through spatial mashups
Zhang, Detian
2017-01-07
In the real world, the route/path with the shortest travel time in a road network is more meaningful than that with the shortest network distance for location-based services (LBS). However, not every LBS provider has adequate resources to compute/estimate travel time for routes by themselves. A cost-effective way for LBS providers to estimate travel time for routes is to issue external route requests to Web mapping services (e.g., Google Maps, Bing Maps, and MapQuest Maps). Due to the high cost of processing such external route requests and the usage limits of Web mapping services, we take the advantage of direction sharing, parallel requesting and waypoints supported by Web mapping services to reduce the number of external route requests and the query response time for shortest travel-time route queries in this paper. We first give the definition of sharing ability to reflect the possibility of sharing the direction information of a route with others, and find out the queries that their query routes are independent with each other for parallel processing. Then, we model the problem of selecting the optimal waypoints for an external route request as finding the longest simple path in a weighted complete digraph. As it is a MAX SNP-hard problem, we propose a greedy algorithm with performance guarantee to find the best set of waypoints in an external route request. We evaluate the performance of our approach using a real Web mapping service, a real road network, real and synthetic data sets. Experimental results show the efficiency, scalability, and applicability of our approach.
Shortest path problem on a grid network with unordered intermediate points
Saw, Veekeong; Rahman, Amirah; Eng Ong, Wen
2017-10-01
We consider a shortest path problem with single cost factor on a grid network with unordered intermediate points. A two stage heuristic algorithm is proposed to find a feasible solution path within a reasonable amount of time. To evaluate the performance of the proposed algorithm, computational experiments are performed on grid maps of varying size and number of intermediate points. Preliminary results for the problem are reported. Numerical comparisons against brute forcing show that the proposed algorithm consistently yields solutions that are within 10% of the optimal solution and uses significantly less computation time.
Influence of drag force upon the shortest time trajectory of an aircraft
Directory of Open Access Journals (Sweden)
Andrei CRAIFALEANU
2015-06-01
Full Text Available The shortest time trajectory of an aircraft between two given locations is determined using a simple mathematical model. By taking into account the drag force (viscous friction force with the air, a problem of variational calculus is obtained which consists in determining two functions that minimize a functional, subject to a non-holonomic constraint. The trajectory is determined directly, by numerical integration of Euler equations with multipliers. Three types of drag forces were considered: constant, linear and quadratic. The results are verified through comparison to the values obtained from numerical minimization of the involved functional approximate forms.
Pereira, Hernane Borges de Barros; Pérez Vidal, Lluís; Lozada, Eleazar G. Madrid
2003-01-01
Behavioral impedance domain consists of a theory on route planning for pedestrians, within which constraint management is considered. The goal of this paper is to present the k-shortest path model using the behavioral impedance approach. After the mathematical model building, optimization problem and resolution problem by a behavioral impedance algorithm, it is discussed how behavioral impedance cost function is embedded in the k-shortest path model. From the pedestrian's route planning persp...
A shortest-path graph kernel for estimating gene product semantic similarity
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Alvarez Marco A
2011-07-01
Full Text Available Abstract Background Existing methods for calculating semantic similarity between gene products using the Gene Ontology (GO often rely on external resources, which are not part of the ontology. Consequently, changes in these external resources like biased term distribution caused by shifting of hot research topics, will affect the calculation of semantic similarity. One way to avoid this problem is to use semantic methods that are "intrinsic" to the ontology, i.e. independent of external knowledge. Results We present a shortest-path graph kernel (spgk method that relies exclusively on the GO and its structure. In spgk, a gene product is represented by an induced subgraph of the GO, which consists of all the GO terms annotating it. Then a shortest-path graph kernel is used to compute the similarity between two graphs. In a comprehensive evaluation using a benchmark dataset, spgk compares favorably with other methods that depend on external resources. Compared with simUI, a method that is also intrinsic to GO, spgk achieves slightly better results on the benchmark dataset. Statistical tests show that the improvement is significant when the resolution and EC similarity correlation coefficient are used to measure the performance, but is insignificant when the Pfam similarity correlation coefficient is used. Conclusions Spgk uses a graph kernel method in polynomial time to exploit the structure of the GO to calculate semantic similarity between gene products. It provides an alternative to both methods that use external resources and "intrinsic" methods with comparable performance.
Floyd-warshall algorithm to determine the shortest path based on android
Ramadiani; Bukhori, D.; Azainil; Dengen, N.
2018-04-01
The development of technology has made all areas of life easier now, one of which is the ease of obtaining geographic information. The use of geographic information may vary according to need, for example, the digital map learning, navigation systems, observations area, and much more. With the support of adequate infrastructure, almost no one will ever get lost to a destination even to foreign places or that have never been visited before. The reasons why many institutions and business entities use technology to improve services to consumers and to streamline the production process undertaken and so forth. Speaking of the efficient, there are many elements related to efficiency in navigation systems, and one of them is the efficiency in terms of distance. The shortest distance determination algorithm required in this research is used Floyd-Warshall Algorithm. Floyd-Warshall algorithm is the algorithm to find the fastest path and the shortest distance between 2 nodes, while the program is intended to find the path of more than 2 nodes.
Comparison of Genetic Algorithm and Hill Climbing for Shortest Path Optimization Mapping
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Fronita Mona
2018-01-01
Full Text Available Traveling Salesman Problem (TSP is an optimization to find the shortest path to reach several destinations in one trip without passing through the same city and back again to the early departure city, the process is applied to the delivery systems. This comparison is done using two methods, namely optimization genetic algorithm and hill climbing. Hill Climbing works by directly selecting a new path that is exchanged with the neighbour’s to get the track distance smaller than the previous track, without testing. Genetic algorithms depend on the input parameters, they are the number of population, the probability of crossover, mutation probability and the number of generations. To simplify the process of determining the shortest path supported by the development of software that uses the google map API. Tests carried out as much as 20 times with the number of city 8, 16, 24 and 32 to see which method is optimal in terms of distance and time computation. Based on experiments conducted with a number of cities 3, 4, 5 and 6 producing the same value and optimal distance for the genetic algorithm and hill climbing, the value of this distance begins to differ with the number of city 7. The overall results shows that these tests, hill climbing are more optimal to number of small cities and the number of cities over 30 optimized using genetic algorithms.
The Shortest Period sdB Plus White Dwarf Binary CD-30 11223 (GALEX J1411-3053)
Czech Academy of Sciences Publication Activity Database
Vennes, Stephane; Kawka, Adela; O'Toole, S.J.; Németh, Péter; Burton, T.
2012-01-01
Roč. 759, č. 1 (2012), L25/1-L25/5 ISSN 2041-8205 R&D Projects: GA ČR GAP209/10/0967 Institutional support: RVO:67985815 Keywords : close binaries * white dwarf s Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 6.345, year: 2012
Chen, Jan-Yow; Lin, Kuo-Hung; Chang, Kuan-Cheng; Chou, Che-Yi
2017-08-03
QRS duration has been associated with the response to cardiac resynchronization therapy (CRT). However, the methods for defining QRS duration to predict the outcome of CRT have discrepancies in previous reports. The aim of this study was to determine an optimal measurement of QRS duration to predict the response to CRT.Sixty-one patients who received CRT were analyzed. All patients had class III-IV heart failure, left ventricular ejection fraction not more than 35%, and complete left bundle branch block. The shortest, longest, and average QRS durations from the 12 leads of each electrocardiogram (ECG) were measured. The responses to CRT were determined using the changes in echocardiography after 6 months. Thirty-five (57.4%) patients were responders and 26 (42.6%) patients were non-responders. The pre-procedure shortest, average, and longest QRS durations and the QRS shortening (ΔQRS) of the shortest QRS duration were significantly associated with the response to CRT in a univariate logistic regression analysis (P = 0.002, P = 0.03, P = 0.04 and P = 0.04, respectively). Based on the measurement of the area under curve of the receiver operating characteristic curve, only the pre-procedure shortest QRS duration and the ΔQRS of the shortest QRS duration showed significant discrimination for the response to CRT (P = 0.002 and P = 0.038, respectively). Multivariable logistic regression showed the pre-procedure shortest QRS duration is an independent predictor for the response to CRT.The shortest QRS duration from the 12 leads of the electrocardiogram might be an optimal measurement to predict the response to CRT.
Quantum return probability of a system of N non-interacting lattice fermions
Krapivsky, P. L.; Luck, J. M.; Mallick, K.
2018-02-01
We consider N non-interacting fermions performing continuous-time quantum walks on a one-dimensional lattice. The system is launched from a most compact configuration where the fermions occupy neighboring sites. We calculate exactly the quantum return probability (sometimes referred to as the Loschmidt echo) of observing the very same compact state at a later time t. Remarkably, this probability depends on the parity of the fermion number—it decays as a power of time for even N, while for odd N it exhibits periodic oscillations modulated by a decaying power law. The exponent also slightly depends on the parity of N, and is roughly twice smaller than what it would be in the continuum limit. We also consider the same problem, and obtain similar results, in the presence of an impenetrable wall at the origin constraining the particles to remain on the positive half-line. We derive closed-form expressions for the amplitudes of the power-law decay of the return probability in all cases. The key point in the derivation is the use of Mehta integrals, which are limiting cases of the Selberg integral.
Energy Technology Data Exchange (ETDEWEB)
Dobschinski, Jan; Wessel, Arne; Lange, Bernhard; Bremen, Lueder von [Fraunhofer Institut fuer Windenergie und Energiesystemtechnik (IWES), Kassel (Germany)
2009-07-01
In electricity systems with large penetration of wind power, the limited predictability of the wind power generation leads to an increase in reserve and balancing requirements. At first the present study concentrates on the capability of dynamic day-ahead prediction intervals to reduce the wind power induced reserve and balancing requirements. Alternatively the reduction of large forecast errors of the German wind power generation by using advanced shortest-term predictions has been evaluated in a second approach. With focus on the allocation of minute reserve power the aim is to estimate the maximal remaining uncertainty after trading activities on the intraday market. Finally both approaches were used in a case study concerning the reserve requirements induced by the total German wind power expansion in 2007. (orig.)
The tomography of human mobility - what do shortest-path trees reveal?
Energy Technology Data Exchange (ETDEWEB)
Thiemann, Christian [Eng. Sci. and Appl. Math, Northwestern University, Evanston, IL (United States); Max-Planck-Institute for Dynamics and Self-Organization, Goettingen (Germany); Grady, Daniel; Brockmann, Dirk [Eng. Sci. and Appl. Math, Northwestern University, Evanston, IL (United States)
2010-07-01
Similar to illustrating the anatomy of organs using pictures of tissue slices taken at various depths, we construct shortest-path trees of different nodes to create tomograms of large-scale human mobility networks. This tomography allows us to measure global properties of the system conditioned on a reference location in the network to gain a fuller characterization of a node. It also suggests a canonical coordinate system for representing complex networks and dynamical processes thereon in a simplified way, revealing a new symmetry in the human mobility networks we investigated. Furthermore, introducing the notion of tree similarity, we devised a new technique for clustering nodes with similar topological footprint, yielding a unique and efficient method for community identification and topological backbone extraction. We applied these methods to a multi-scale human mobility network obtained from the dollar-bill-tracking site wheresgoerge.com and to the U.S. and world-wide air transportation network.
A minimum resource neural network framework for solving multiconstraint shortest path problems.
Zhang, Junying; Zhao, Xiaoxue; He, Xiaotao
2014-08-01
Characterized by using minimum hard (structural) and soft (computational) resources, a novel parameter-free minimal resource neural network (MRNN) framework is proposed for solving a wide range of single-source shortest path (SP) problems for various graph types. The problems are the k-shortest time path problems with any combination of three constraints: time, hop, and label constraints, and the graphs can be directed, undirected, or bidirected with symmetric and/or asymmetric traversal time, which can be real and time dependent. Isomorphic to the graph where the SP is to be sought, the network is activated by generating autowave at source neuron and the autowave travels automatically along the paths with the speed of a hop in an iteration. Properties of the network are studied, algorithms are presented, and computation complexity is analyzed. The framework guarantees globally optimal solutions of a series of problems during the iteration process of the network, which provides insight into why even the SP is still too long to be satisfied. The network facilitates very large scale integrated circuit implementation and adapt to very large scale problems due to its massively parallel processing and minimum resource utilization. When implemented in a sequentially processing computer, experiments on synthetic graphs, road maps of cities of the USA, and vehicle routing with time windows indicate that the MRNN is especially efficient for large scale sparse graphs and even dense graphs with some constraints, e.g., the CPU time taken and the iteration number used for the road maps of cities of the USA is even less than ∼ 2% and 0.5% that of the Dijkstra's algorithm.
A MODIFIED GENETIC ALGORITHM FOR FINDING FUZZY SHORTEST PATHS IN UNCERTAIN NETWORKS
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A. A. Heidari
2016-06-01
Full Text Available In realistic network analysis, there are several uncertainties in the measurements and computation of the arcs and vertices. These uncertainties should also be considered in realizing the shortest path problem (SPP due to the inherent fuzziness in the body of expert's knowledge. In this paper, we investigated the SPP under uncertainty to evaluate our modified genetic strategy. We improved the performance of genetic algorithm (GA to investigate a class of shortest path problems on networks with vague arc weights. The solutions of the uncertain SPP with considering fuzzy path lengths are examined and compared in detail. As a robust metaheuristic, GA algorithm is modified and evaluated to tackle the fuzzy SPP (FSPP with uncertain arcs. For this purpose, first, a dynamic operation is implemented to enrich the exploration/exploitation patterns of the conventional procedure and mitigate the premature convergence of GA technique. Then, the modified GA (MGA strategy is used to resolve the FSPP. The attained results of the proposed strategy are compared to those of GA with regard to the cost, quality of paths and CPU times. Numerical instances are provided to demonstrate the success of the proposed MGA-FSPP strategy in comparison with GA. The simulations affirm that not only the proposed technique can outperform GA, but also the qualities of the paths are effectively improved. The results clarify that the competence of the proposed GA is preferred in view of quality quantities. The results also demonstrate that the proposed method can efficiently be utilized to handle FSPP in uncertain networks.
A 2D analytical cylindrical gate tunnel FET (CG-TFET) model: impact of shortest tunneling distance
Dash, S.; Mishra, G. P.
2015-09-01
A 2D analytical tunnel field-effect transistor (FET) potential model with cylindrical gate (CG-TFET) based on the solution of Laplace’s equation is proposed. The band-to-band tunneling (BTBT) current is derived by the help of lateral electric field and the shortest tunneling distance. However, the analysis is extended to obtain the subthreshold swing (SS) and transfer characteristics of the device. The dependency of drain current, SS and transconductance on gate voltage and shortest tunneling distance is discussed. Also, the effect of scaling the gate oxide thickness and the cylindrical body diameter on the electrical parameters of the device is analyzed.
A 2D analytical cylindrical gate tunnel FET (CG-TFET) model: impact of shortest tunneling distance
International Nuclear Information System (INIS)
Dash, S; Mishra, G P
2015-01-01
A 2D analytical tunnel field-effect transistor (FET) potential model with cylindrical gate (CG-TFET) based on the solution of Laplace’s equation is proposed. The band-to-band tunneling (BTBT) current is derived by the help of lateral electric field and the shortest tunneling distance. However, the analysis is extended to obtain the subthreshold swing (SS) and transfer characteristics of the device. The dependency of drain current, SS and transconductance on gate voltage and shortest tunneling distance is discussed. Also, the effect of scaling the gate oxide thickness and the cylindrical body diameter on the electrical parameters of the device is analyzed. (paper)
Directory of Open Access Journals (Sweden)
Mazyar Seraj
2014-06-01
Full Text Available In recent years, many studies have been carried out on how to engage and support students in e-learning environments. Portable devices such as Personal Digital Assistants (PDAs, Tablet PCs, mobile phones and other mobile equipment have been used as parts of electronic learning environments to facilitate learning and teaching for both lecturers and students. However, there is still a dearth of study investigating the effects of small screen interfaces on mobile-based learning environments. This study aims to address two objectives: (i investigate lecturer and student difficulties encountered in teaching-learning process in traditional face-to-face classroom settings, and (ii to explore lecturer and student perceptions about learning the subject through mobile devices. This paper presents the results of a qualitative study using structured interviews to investigate lecturer and student experiences and perceptions on teaching and learning Dijkstra’s shortest path algorithm via mobile devices. The interview insights were then used as inputs to define user requirements for a mobile learning prototype. The findings show that the lecturers and students raised many issues about interactivity and the flexibility of effective learning applications on small screen devices, especially for a technical subject.
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Matheswaran Saravanan
2014-01-01
Full Text Available Wireless sensor network (WSN consists of sensor nodes that need energy efficient routing techniques as they have limited battery power, computing, and storage resources. WSN routing protocols should enable reliable multihop communication with energy constraints. Clustering is an effective way to reduce overheads and when this is aided by effective resource allocation, it results in reduced energy consumption. In this work, a novel hybrid evolutionary algorithm called Bee Algorithm-Simulated Annealing Weighted Minimal Spanning Tree (BASA-WMST routing is proposed in which randomly deployed sensor nodes are split into the best possible number of independent clusters with cluster head and optimal route. The former gathers data from sensors belonging to the cluster, forwarding them to the sink. The shortest intrapath selection for the cluster is selected using Weighted Minimum Spanning Tree (WMST. The proposed algorithm computes the distance-based Minimum Spanning Tree (MST of the weighted graph for the multihop network. The weights are dynamically changed based on the energy level of each sensor during route selection and optimized using the proposed bee algorithm simulated annealing algorithm.
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Yunyue He
Full Text Available Emergency evacuation aims to transport people from dangerous places to safe shelters as quickly as possible. Police play an important role in the evacuation process, as they can handle traffic accidents immediately and help people move smoothly on roads. This paper investigates an evacuation routing problem that involves police resource allocation. We propose a novel k-th-shortest-path-based technique that uses explicit congestion control to optimize evacuation routing and police resource allocation. A nonlinear mixed-integer programming model is presented to formulate the problem. The model's objective is to minimize the overall evacuation clearance time. Two algorithms are given to solve the problem. The first one linearizes the original model and solves the linearized problem with CPLEX. The second one is a heuristic algorithm that uses a police resource utilization efficiency index to directly solve the original model. This police resource utilization efficiency index significantly aids in the evaluation of road links from an evacuation throughput perspective. The proposed algorithms are tested with a number of examples based on real data from cities of different sizes. The computational results show that the police resource utilization efficiency index is very helpful in finding near-optimal solutions. Additionally, comparing the performance of the heuristic algorithm and the linearization method by using randomly generated examples indicates that the efficiency of the heuristic algorithm is superior.
Distribution of shortest path lengths in a class of node duplication network models
Steinbock, Chanania; Biham, Ofer; Katzav, Eytan
2017-09-01
We present analytical results for the distribution of shortest path lengths (DSPL) in a network growth model which evolves by node duplication (ND). The model captures essential properties of the structure and growth dynamics of social networks, acquaintance networks, and scientific citation networks, where duplication mechanisms play a major role. Starting from an initial seed network, at each time step a random node, referred to as a mother node, is selected for duplication. Its daughter node is added to the network, forming a link to the mother node, and with probability p to each one of its neighbors. The degree distribution of the resulting network turns out to follow a power-law distribution, thus the ND network is a scale-free network. To calculate the DSPL we derive a master equation for the time evolution of the probability Pt(L =ℓ ) , ℓ =1 ,2 ,⋯ , where L is the distance between a pair of nodes and t is the time. Finding an exact analytical solution of the master equation, we obtain a closed form expression for Pt(L =ℓ ) . The mean distance 〈L〉 t and the diameter Δt are found to scale like lnt , namely, the ND network is a small-world network. The variance of the DSPL is also found to scale like lnt . Interestingly, the mean distance and the diameter exhibit properties of a small-world network, rather than the ultrasmall-world network behavior observed in other scale-free networks, in which 〈L〉 t˜lnlnt .
The highest velocity and the shortest duration permitting attainment of VO2max during running
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Tiago Turnes
2015-02-01
Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2015v17n2p226 The severe-intensity domain has important applications for the prescription of running training and the elaboration of experimental designs. The objectives of this study were: 1 to investigate the validity of a previously proposed model to estimate the shortest exercise duration (TLOW and the highest velocity (VHIGH at which VO2max is reached during running, and 2 to evaluate the effects of aerobic training status on these variables. Eight runners and eight physically active subjects performed several treadmill running exercise tests to fatigue in order to mathematically estimate and to experimentally determine TLOW and VHIGH. The relationship between the time to achieve VO2max and time to exhaustion (Tlim was used to estimate TLOW. VHIGH was estimated using the critical velocity model. VHIGH was assumed to be the highest velocity at which VO2 was equal to or higher than the average VO2max minus one standard deviation. TLOW was defined as Tlim associated with VHIGH. Runners presented better aerobic fitness and higher VHIGH (22.2 ± 1.9 km.h-1 than active subjects (20.0 ± 2.1 km.h-1. However, TLOW did not differ between groups (runners: 101 ± 39 s; active subjects: 100 ± 35 s. TLOW and VHIGH were not well estimated by the model proposed, with high coefficients of variation (> 6% and a low correlation coefficient (r<0.70, a fact reducing the validity of the model. It was concluded that aerobic training status positively affected only VHIGH. Furthermore, the model proposed presented low validity to estimate the upper boundary of the severe-intensity domain (i.e., VHIGH, irrespective of the subjects’ training status.
Can Non-Interactive Language Input Benefit Young Second-Language Learners?
Au, Terry Kit-fong; Chan, Winnie Wailan; Cheng, Liao; Siegel, Linda S.; Tso, Ricky Van Yip
2015-01-01
To fully acquire a language, especially its phonology, children need linguistic input from native speakers early on. When interaction with native speakers is not always possible--e.g. for children learning a second language that is not the societal language--audios are commonly used as an affordable substitute. But does such non-interactive input…
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Mazyar Seraj
2014-10-01
Full Text Available This paper describes an experimental study of learning Dijkstra’s shortest path algorithm on mobile devices. The aim of the study is to investigate and compare the impacts of two different mobile screen user interfaces on students’ satisfaction for learning the technical subject. A mobile learning prototype was developed for learning Dijkstra’s shortest path algorithm on Apple iPhone 4 operated on iPhone operating system (iOS, and Acer Inconia Tab operated on an Android operating system. Thirty students, who are either currently studying or had previously studied Computer Networks, were recruited for the usability trial. At the end of each single session, students’ satisfaction interacting with the two mobile devices was measured using QUIS questionnaire. Although there is no significant difference in students’ satisfaction between the two different mobile screen interfaces, the subjective findings indicate that Acer Inconia Tab gained higher scores as compared to Apple iPhone 4.
Freshness-Preserving Non-Interactive Hierarchical Key Agreement Protocol over WHMS
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Hyunsung Kim
2014-12-01
Full Text Available The digitization of patient health information (PHI for wireless health monitoring systems (WHMSs has brought many benefits and challenges for both patients and physicians. However, security, privacy and robustness have remained important challenges for WHMSs. Since the patient’s PHI is sensitive and the communication channel, i.e., the Internet, is insecure, it is important to protect them against unauthorized entities, i.e., attackers. Otherwise, failure to do so will not only lead to the compromise of a patient’s privacy, but will also put his/her life at risk. This paper proposes a freshness-preserving non-interactive hierarchical key agreement protocol (FNKAP for WHMSs. The FNKAP is based on the concept of the non-interactive identity-based key agreement for communication efficiency. It achieves patient anonymity between a patient and physician, session key secrecy and resistance against various security attacks, especially including replay attacks.
Freshness-Preserving Non-Interactive Hierarchical Key Agreement Protocol over WHMS
Kim, Hyunsung
2014-01-01
The digitization of patient health information (PHI) for wireless health monitoring systems (WHMSs) has brought many benefits and challenges for both patients and physicians. However, security, privacy and robustness have remained important challenges for WHMSs. Since the patient's PHI is sensitive and the communication channel, i.e., the Internet, is insecure, it is important to protect them against unauthorized entities, i.e., attackers. Otherwise, failure to do so will not only lead to the compromise of a patient's privacy, but will also put his/her life at risk. This paper proposes a freshness-preserving non-interactive hierarchical key agreement protocol (FNKAP) for WHMSs. The FNKAP is based on the concept of the non-interactive identity-based key agreement for communication efficiency. It achieves patient anonymity between a patient and physician, session key secrecy and resistance against various security attacks, especially including replay attacks. PMID:25513824
On the decomposition of a dynamical system into non-interacting subsystems.
Rosen, R.
1972-01-01
It is shown that, under rather general conditions, it is possible to formally decompose the dynamics of an n-dimensional dynamical system into a number of non-interacting subsystems. It is shown that these decompositions are in general not simply related to the kinds of observational procedures in terms of which the original state variables of the system are defined. Some consequences of this construction for reductionism in biology are discussed.
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David S. Hardin
2013-04-01
Full Text Available As Graphics Processing Units (GPUs have gained in capability and GPU development environments have matured, developers are increasingly turning to the GPU to off-load the main host CPU of numerically-intensive, parallelizable computations. Modern GPUs feature hundreds of cores, and offer programming niceties such as double-precision floating point, and even limited recursion. This shift from CPU to GPU, however, raises the question: how do we know that these new GPU-based algorithms are correct? In order to explore this new verification frontier, we formalized a parallelizable all-pairs shortest path (APSP algorithm for weighted graphs, originally coded in NVIDIA's CUDA language, in ACL2. The ACL2 specification is written using a single-threaded object (stobj and tail recursion, as the stobj/tail recursion combination yields the most straightforward translation from imperative programming languages, as well as efficient, scalable executable specifications within ACL2 itself. The ACL2 version of the APSP algorithm can process millions of vertices and edges with little to no garbage generation, and executes at one-sixth the speed of a host-based version of APSP coded in C – a very respectable result for a theorem prover. In addition to formalizing the APSP algorithm (which uses Dijkstra's shortest path algorithm at its core, we have also provided capability that the original APSP code lacked, namely shortest path recovery. Path recovery is accomplished using a secondary ACL2 stobj implementing a LIFO stack, which is proven correct. To conclude the experiment, we ported the ACL2 version of the APSP kernels back to C, resulting in a less than 5% slowdown, and also performed a partial back-port to CUDA, which, surprisingly, yielded a slight performance increase.
Revisiting the density scaling of the non-interacting kinetic energy.
Borgoo, Alex; Teale, Andrew M; Tozer, David J
2014-07-28
Scaling relations play an important role in the understanding and development of approximate functionals in density functional theory. Recently, a number of these relationships have been redefined in terms of the Kohn-Sham orbitals [Calderín, Phys. Rev. A: At., Mol., Opt. Phys., 2013, 86, 032510]. For density scaling the author proposed a procedure involving a multiplicative scaling of the Kohn-Sham orbitals whilst keeping their occupation numbers fixed. In the present work, the differences between this scaling with fixed occupation numbers and that of previous studies, where the particle number change implied by the scaling was accommodated through the use of the grand canonical ensemble, are examined. We introduce the terms orbital and ensemble density scaling for these approaches, respectively. The natural ambiguity of the density scaling of the non-interacting kinetic energy functional is examined and the ancillary definitions implicit in each approach are highlighted and compared. As a consequence of these differences, Calderín recovered a homogeneity of degree 1 for the non-interacting kinetic energy functional under orbital scaling, contrasting recent work by the present authors [J. Chem. Phys., 2012, 136, 034101] where the functional was found to be inhomogeneous under ensemble density scaling. Furthermore, we show that the orbital scaling result follows directly from the linearity and the single-particle nature of the kinetic energy operator. The inhomogeneity of the non-interacting kinetic energy functional under ensemble density scaling can be quantified by defining an effective homogeneity. This quantity is shown to recover the homogeneity values for important approximate forms that are exact for limiting cases such as the uniform electron gas and one-electron systems. We argue that the ensemble density scaling provides more insight into the development of new functional forms.
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Durisman Durisman
2017-09-01
Full Text Available Banda Aceh city and Aceh Besar Regency are two of the leading tourism areas located in the province of Aceh. For travelling, there are some important things to be considered, such as determining schedule and distance of tourism. Every tourist certainly chooses the shortest route to reach the destination since it can save time, energy, and money. The purpose of this reserach is to develop a method that can be used in calculating the shortest route and applied to the tourism of Banda Aceh city and Aceh Besar regency. In this reserach, Ant Colony Optimization algorithm is used to determine the shortest route to tourism of Banda Aceh city and Aceh Besar regency. From the analysis made by using both manual calculation and GUI MATLAB program application test, the shortest route can be obtained with a minimum distance of 120.85 km in one travel. Based on the test result, the application for tourism (in Banda Aceh city and Aceh Besar regency shortest route searching built by utilizing the Ant Colony Optimization algorithm can find optimal route. Keyword: tourism, the shortest route, Ant Colony Optimization
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Petruseva Silvana
2006-01-01
Full Text Available This paper discusses the comparison of the efficiency of two algorithms, by estimation of their complexity. For solving the problem, the Neural Network Crossbar Adaptive Array (NN-CAA is used as the agent architecture, implementing a model of an emotion. The problem discussed is how to find the shortest path in an environment with n states. The domains concerned are environments with n states, one of which is the starting state, one is the goal state, and some states are undesirable and they should be avoided. It is obtained that finding one path (one solution is efficient, i.e. in polynomial time by both algorithms. One of the algorithms is faster than the other only in the multiplicative constant, and it shows a step forward toward the optimality of the learning process. However, finding the optimal solution (the shortest path by both algorithms is in exponential time which is asserted by two theorems. It might be concluded that the concept of subgoal is one step forward toward the optimality of the process of the agent learning. Yet, it should be explored further on, in order to obtain an efficient, polynomial algorithm.
Huang, Guo-Jiao; Bai, Chao-Ying; Greenhalgh, Stewart
2013-09-01
The traditional grid/cell-based wavefront expansion algorithms, such as the shortest path algorithm, can only find the first arrivals or multiply reflected (or mode converted) waves transmitted from subsurface interfaces, but cannot calculate the other later reflections/conversions having a minimax time path. In order to overcome the above limitations, we introduce the concept of a stationary minimax time path of Fermat's Principle into the multistage irregular shortest path method. Here we extend it from Cartesian coordinates for a flat earth model to global ray tracing of multiple phases in a 3-D complex spherical earth model. The ray tracing results for 49 different kinds of crustal, mantle and core phases show that the maximum absolute traveltime error is less than 0.12 s and the average absolute traveltime error is within 0.09 s when compared with the AK135 theoretical traveltime tables for a 1-D reference model. Numerical tests in terms of computational accuracy and CPU time consumption indicate that the new scheme is an accurate, efficient and a practical way to perform 3-D multiphase arrival tracking in regional or global traveltime tomography.
Search for primarily non-interacting decay modes of the upsilon
International Nuclear Information System (INIS)
Leffler, J.S.
1986-03-01
The hadronic transition UPSILON(2S) → π 0 π 0 UPSILON(1S) is utilized to search for the reactions: UPSILON(1S) → non-interacting particles and UPSILON(1S) → γ + non-interacting particles. 44 pb -1 of UPSILON(2S) data were taken by the Crystal Ball detector at the DORIS II storage ring in order to perform this study. An upper limit of BR(UPSILON → Unseen) -1 of UPSILON(2S) data was available for this study. An upper limit on the branching ratio BR(UPSILON → γ + Unseen) is measured for photon energies in the range 500 MeV -3 (90% C.L.), is obtained. The compact size of the Crystal Ball detector enhances the observable branching ratio for noninteracting particles with short lifetimes such as massive axions. The identification of the recent Darmstadt events with a 1.6 MeV axion is excluded by the present result assuming the minimal Peccei-Quinn model. Limits on the spontaneous supersymmetry breaking mass scale are also derived as a function of gravitino mass
Momentum distribution of non-interacting fermions enclosed in a box
International Nuclear Information System (INIS)
Krivine, H.
1985-01-01
This is a study of: the finite size effect on the momentum distribution n(/sup →/k) of an ensemble of A non-interacting fermions enclosed in a box. Analytical expressions are obtained in the two limiting cases the Fermi momentum. The result is to analyze the convergence of toward the standard step function in the infinite medium. Applying results to the nuclear case, changes are compared in n(/sup →/k) generated by the finite size of actual nuclei to those due to short range correlations. Both effects are shown to be of same order of magnitude. The next step is to take into account the short range correlations in finite systems
Authentication Based on Non-Interactive Zero-Knowledge Proofs for the Internet of Things.
Martín-Fernández, Francisco; Caballero-Gil, Pino; Caballero-Gil, Cándido
2016-01-07
This paper describes the design and analysis of a new scheme for the authenticated exchange of confidential information in insecure environments within the Internet of Things, which allows a receiver of a message to authenticate the sender and compute a secret key shared with it. The proposal is based on the concept of a non-interactive zero-knowledge proof, so that in a single communication, relevant data may be inferred to verify the legitimacy of the sender. Besides, the new scheme uses the idea under the Diffie-Hellman protocol for the establishment of a shared secret key. The proposal has been fully developed for platforms built on the Android Open Source Project, so it can be used in any device or sensor with this operating system. This work provides a performance study of the implementation and a comparison between its promising results and others obtained with similar schemes.
Authentication Based on Non-Interactive Zero-Knowledge Proofs for the Internet of Things
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Francisco Martín-Fernández
2016-01-01
Full Text Available This paper describes the design and analysis of a new scheme for the authenticated exchange of confidential information in insecure environments within the Internet of Things, which allows a receiver of a message to authenticate the sender and compute a secret key shared with it. The proposal is based on the concept of a non-interactive zero-knowledge proof, so that in a single communication, relevant data may be inferred to verify the legitimacy of the sender. Besides, the new scheme uses the idea under the Diffie–Hellman protocol for the establishment of a shared secret key. The proposal has been fully developed for platforms built on the Android Open Source Project, so it can be used in any device or sensor with this operating system. This work provides a performance study of the implementation and a comparison between its promising results and others obtained with similar schemes.
Zhu, Liucun; Zhang, Yu-Hang; Su, Fangchu; Chen, Lei; Huang, Tao; Cai, Yu-Dong
2016-01-01
Biologically, fruits are defined as seed-bearing reproductive structures in angiosperms that develop from the ovary. The fertilization, development and maturation of fruits are crucial for plant reproduction and are precisely regulated by intrinsic genetic regulatory factors. In this study, we used Arabidopsis thaliana as a model organism and attempted to identify novel genes related to fruit-associated biological processes. Specifically, using validated genes, we applied a shortest-path-based method to identify several novel genes in a large network constructed using the protein-protein interactions observed in Arabidopsis thaliana. The described analyses indicate that several of the discovered genes are associated with fruit fertilization, development and maturation in Arabidopsis thaliana.
Verhoeven, Hannah; Van Hecke, Linde; Van Dyck, Delfien; Baert, Tim; Van de Weghe, Nico; Clarys, Peter; Deforche, Benedicte; Van Cauwenberg, Jelle
2018-05-29
The objective evaluation of the physical environmental characteristics (e.g. speed limit, cycling infrastructure) along adolescents' actual cycling routes remains understudied, although it may provide important insights into why adolescents prefer one cycling route over another. The present study aims to gain insight into the physical environmental characteristics determining the route choice of adolescent cyclists by comparing differences in physical environmental characteristics between their actual cycling routes and the shortest possible cycling routes. Adolescents (n = 204; 46.5% boys; 14.4 ± 1.2 years) recruited at secondary schools in and around Ghent (city in Flanders, northern part of Belgium) were instructed to wear a Global Positioning System device in order to identify cycling trips. For all identified cycling trips, the shortest possible route that could have been taken was calculated. Actual cycling routes that were not the shortest possible cycling routes were divided into street segments. Segments were audited with a Google Street View-based tool to assess physical environmental characteristics along actual and shortest cycling routes. Out of 160 actual cycling trips, 73.1% did not differ from the shortest possible cycling route. For actual cycling routes that were not the shortest cycling route, a speed limit of 30 km/h, roads having few buildings with windows on the street side and roads without cycle lane were more frequently present compared to the shortest possible cycling routes. A mixed land use, roads with commercial destinations, arterial roads, cycle lanes separated from traffic by white lines, small cycle lanes and cycle lanes covered by lighting were less frequently present along actual cycling routes compared to the shortest possible cycling routes. Results showed that distance mainly determines the route along which adolescents cycle. In addition, adolescents cycled more along residential streets (even if no cycle lane was
The shortest argument for the existence of God in Islamic philosophy
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Halilović Seid
2014-01-01
Full Text Available The first cognitive frameworks of the undoubtedly most famous argument for the existence of God in Islamic philosophy were set by the notable Ibn Sina. Having proved the existence of God by considering existence itself, in his famous philosophical book al-Isharat he wrote that in that way he offered the 'argument of the veracious'. In the following stages of the development of this argument this syntagm will become one of the most popular scientific names in the history of philosophical and rational thought in Muslims. Numerous representatives of various schools of philosophy, dogmatic theology and doctrinal gnosis in Islam thoroughly analyzed the text of this part of the al-Isharat book and sometimes formulated new versions of the 'argument of the veracious'. In this paper we will focus on the basic cognitive milestones in the development of this argument and with a view to acquiring this we will use the method of detailed content analysis of the works of those Muslim philosophers who contributed significantly to that intellectual process. Given that scientific destiny of the 'argument of the veracious' quite attractively illustrates the various stages of the development of entire Islamic philosophy, we will try to show that in each new period Islamic philosophical heritage grew a more vital and dominant scientific discipline. On the other hand, we will conclude that throughout history Islamic philosophy and 'arguments of the veracious' have become more reminiscent of subtle intuition of Muslim gnostics and innermost spheres of the original understanding of the sacred Islamic texts and traditions.
Energy Technology Data Exchange (ETDEWEB)
Dufton, P. L.; Dunstall, P. R.; Fraser, M. [Astrophysics Research Centre, School of Mathematics and Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Evans, C. J. [UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Brott, I. [University of Vienna, Department of Astronomy, Tuerkenschanzstr. 17, A-1180 Vienna (Austria); Cantiello, M.; Langer, N. [Argelander Institut fuer Astronomie der Universitaet Bonn, Auf dem Huegel 71, 53121 Bonn (Germany); De Koter, A.; Sana, H. [Astronomical Institute ' Anton Pannekoek' , University of Amsterdam, Postbus 94249, 1090 GE Amsterdam (Netherlands); De Mink, S. E. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Henault-Brunet, V.; Taylor, W. D. [Scottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Howarth, I. D. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Lennon, D. J. [ESA, Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Markova, N., E-mail: p.dufton@qub.ac.uk [Institute of Astronomy with NAO, Bulgarian Academy of Sciences, P.O. Box 136, 4700 Smoljan (Bulgaria)
2011-12-10
We present a spectroscopic analysis of an extremely rapidly rotating late O-type star, VFTS102, observed during a spectroscopic survey of 30 Doradus. VFTS102 has a projected rotational velocity larger than 500 km s{sup -1} and probably as large as 600 km s{sup -1}; as such it would appear to be the most rapidly rotating massive star currently identified. Its radial velocity differs by 40 km s{sup -1} from the mean for 30 Doradus, suggesting that it is a runaway. VFTS102 lies 12 pc from the X-ray pulsar PSR J0537-6910 in the tail of its X-ray diffuse emission. We suggest that these objects originated from a binary system with the rotational and radial velocities of VFTS102 resulting from mass transfer from the progenitor of PSR J0537-691 and the supernova explosion, respectively.
Trickey, Samuel; Karasiev, Valentin
We introduce the concept of tunable orbital-free non-interacting free-energy density functionals and present a generalized gradient approximation (GGA) with a subset of parameters defined from constraints and a few free parameters. Those free parameters are tuned to reproduce reference Kohn-Sham (KS) static-lattice pressures for Al at T=8 kK for bulk densities between 0.6 and 2 g/cm3. The tuned functional then is used in OF molecular dynamics (MD) simulations for Al with densities between 0.1 and 2 g/cm3 and T between 6 and 50 kK to calculate the equation of state and generate configurations for electrical conductivity calculations. The tunable functional produces accurate results. Computationally it is very effective especially at elevated temperature. Kohn-Shiam calculations for such low densities are affordable only up to T=10 kK, while other OF approximations, including two-point functionals, fail badly in that regime. Work supported by US DoE Grant DE-SC0002139.
Consequences of repeated discovery and benign neglect of non-interaction of waves (NIW)
Roychoudhuri, ChandraSekhar
2017-08-01
This paper presents the historical background behind the repeated discovery and repeated ignoring of the generic important property of all propagating waves, the Non-Interaction of Waves (NIW). The focus will be on the implications of NIW in most of the major optical phenomena with brief hints of importance. We argue that the prevailing postulate of wave-particle duality becomes unnecessary, once we accept NIW. Semi-classical model of treating light-matter interactions should be the preferred approach since the quantumness actually arises from within the structure of the energy levels (bands) in materials. Waves, and wave equations, do not support bullet-like propagation. We follow the historical trend starting from the tenth century physicist Alhazen, to the seventeenth century Newton and Huygens, then to the nineteenth century Young and Fresnel. Then we jump to twentieth century physicists Planck, Einstein, Bose, Dirac and Feynman. Had we recognized and appreciated NIW property of waves from the time of Alhazen, the evolutionary history of physics would have been dramatically different from what we have today. The prevailing dominance of the postulate of wave-particle duality is keeping us confused from seeking out actual reality; and hence, we should abandon this concept and search out better models. The paper demonstrates that NIW provides us with a platform for deeper understanding of the nature of EM waves that we have missed; it is not just semantics.
Non-additive non-interacting kinetic energy of rare gas dimers
Jiang, Kaili; Nafziger, Jonathan; Wasserman, Adam
2018-03-01
Approximations of the non-additive non-interacting kinetic energy (NAKE) as an explicit functional of the density are the basis of several electronic structure methods that provide improved computational efficiency over standard Kohn-Sham calculations. However, within most fragment-based formalisms, there is no unique exact NAKE, making it difficult to develop general, robust approximations for it. When adjustments are made to the embedding formalisms to guarantee uniqueness, approximate functionals may be more meaningfully compared to the exact unique NAKE. We use numerically accurate inversions to study the exact NAKE of several rare-gas dimers within partition density functional theory, a method that provides the uniqueness for the exact NAKE. We find that the NAKE decreases nearly exponentially with atomic separation for the rare-gas dimers. We compute the logarithmic derivative of the NAKE with respect to the bond length for our numerically accurate inversions as well as for several approximate NAKE functionals. We show that standard approximate NAKE functionals do not reproduce the correct behavior for this logarithmic derivative and propose two new NAKE functionals that do. The first of these is based on a re-parametrization of a conjoint Perdew-Burke-Ernzerhof (PBE) functional. The second is a simple, physically motivated non-decomposable NAKE functional that matches the asymptotic decay constant without fitting.
Directory of Open Access Journals (Sweden)
Vatutin Eduard
2017-12-01
Full Text Available The article deals with the problem of analysis of effectiveness of the heuristic methods with limited depth-first search techniques of decision obtaining in the test problem of getting the shortest path in graph. The article briefly describes the group of methods based on the limit of branches number of the combinatorial search tree and limit of analyzed subtree depth used to solve the problem. The methodology of comparing experimental data for the estimation of the quality of solutions based on the performing of computational experiments with samples of graphs with pseudo-random structure and selected vertices and arcs number using the BOINC platform is considered. It also shows description of obtained experimental results which allow to identify the areas of the preferable usage of selected subset of heuristic methods depending on the size of the problem and power of constraints. It is shown that the considered pair of methods is ineffective in the selected problem and significantly inferior to the quality of solutions that are provided by ant colony optimization method and its modification with combinatorial returns.
Vatutin, Eduard
2017-12-01
The article deals with the problem of analysis of effectiveness of the heuristic methods with limited depth-first search techniques of decision obtaining in the test problem of getting the shortest path in graph. The article briefly describes the group of methods based on the limit of branches number of the combinatorial search tree and limit of analyzed subtree depth used to solve the problem. The methodology of comparing experimental data for the estimation of the quality of solutions based on the performing of computational experiments with samples of graphs with pseudo-random structure and selected vertices and arcs number using the BOINC platform is considered. It also shows description of obtained experimental results which allow to identify the areas of the preferable usage of selected subset of heuristic methods depending on the size of the problem and power of constraints. It is shown that the considered pair of methods is ineffective in the selected problem and significantly inferior to the quality of solutions that are provided by ant colony optimization method and its modification with combinatorial returns.
Chen, Lei; Liu, Tao; Zhao, Xian
2018-06-01
The anatomical therapeutic chemical (ATC) classification system is a widely accepted drug classification scheme. This system comprises five levels and includes several classes in each level. Drugs are classified into classes according to their therapeutic effects and characteristics. The first level includes 14 main classes. In this study, we proposed two network-based models to infer novel potential chemicals deemed to belong in the first level of ATC classification. To build these models, two large chemical networks were constructed using the chemical-chemical interaction information retrieved from the Search Tool for Interactions of Chemicals (STITCH). Two classic network algorithms, shortest path (SP) and random walk with restart (RWR) algorithms, were executed on the corresponding network to mine novel chemicals for each ATC class using the validated drugs in a class as seed nodes. Then, the obtained chemicals yielded by these two algorithms were further evaluated by a permutation test and an association test. The former can exclude chemicals produced by the structure of the network, i.e., false positive discoveries. By contrast, the latter identifies the most important chemicals that have strong associations with the ATC class. Comparisons indicated that the two models can provide quite dissimilar results, suggesting that the results yielded by one model can be essential supplements for those obtained by the other model. In addition, several representative inferred chemicals were analyzed to confirm the reliability of the results generated by the two models. This article is part of a Special Issue entitled: Accelerating Precision Medicine through Genetic and Genomic Big Data Analysis edited by Yudong Cai & Tao Huang. Copyright © 2017 Elsevier B.V. All rights reserved.
Directory of Open Access Journals (Sweden)
Michaeli Shulamit
2007-10-01
Full Text Available Abstract Background In recent years, RNA molecules that are not translated into proteins (ncRNAs have drawn a great deal of attention, as they were shown to be involved in many cellular functions. One of the most important computational problems regarding ncRNA is to predict the secondary structure of a molecule from its sequence. In particular, we attempted to predict the secondary structure for a set of unaligned ncRNA molecules that are taken from the same family, and thus presumably have a similar structure. Results We developed the RNAspa program, which comparatively predicts the secondary structure for a set of ncRNA molecules in linear time in the number of molecules. We observed that in a list of several hundred suboptimal minimal free energy (MFE predictions, as provided by the RNAsubopt program of the Vienna package, it is likely that at least one suggested structure would be similar to the true, correct one. The suboptimal solutions of each molecule are represented as a layer of vertices in a graph. The shortest path in this graph is the basis for structural predictions for the molecule. We also show that RNA secondary structures can be compared very rapidly by a simple string Edit-Distance algorithm with a minimal loss of accuracy. We show that this approach allows us to more deeply explore the suboptimal structure space. Conclusion The algorithm was tested on three datasets which include several ncRNA families taken from the Rfam database. These datasets allowed for comparison of the algorithm with other methods. In these tests, RNAspa performed better than four other programs.
Observations and light curve solutions of four ultrashort-period binaries
Directory of Open Access Journals (Sweden)
Kjurkchieva D.
2016-01-01
Full Text Available The paper presents light curve solutions of our observations of four new ultrashort-period eclipsing binaries with MS components. Two of them have periods almost at the upper limit (0.22 days of the ultrashort-period binaries, while the periods of around 0.18 days of CSS J171508.5+350658 and CSS J214633.8+120016 are amongst the shortest known orbital periods. CSS J171410.0+ 445850, CSS J214633.8+120016 and CSS J224326.0+154532 are over contact binaries with fill out factors around 0.25 while CSS J171508.5+350658 is a semidetached system. The two targets with shortest periods consist of M dwarfs.
International Nuclear Information System (INIS)
Zhou, Yongxi; Ernzerhof, Matthias; Bahmann, Hilke
2015-01-01
Drawing on the adiabatic connection of density functional theory, exchange-correlation functionals of Kohn-Sham density functional theory are constructed which interpolate between the extreme limits of the electron-electron interaction strength. The first limit is the non-interacting one, where there is only exchange. The second limit is the strong correlated one, characterized as the minimum of the electron-electron repulsion energy. The exchange-correlation energy in the strong-correlation limit is approximated through a model for the exchange-correlation hole that is referred to as nonlocal-radius model [L. O. Wagner and P. Gori-Giorgi, Phys. Rev. A 90, 052512 (2014)]. Using the non-interacting and strong-correlated extremes, various interpolation schemes are presented that yield new approximations to the adiabatic connection and thus to the exchange-correlation energy. Some of them rely on empiricism while others do not. Several of the proposed approximations yield the exact exchange-correlation energy for one-electron systems where local and semi-local approximations often fail badly. Other proposed approximations generalize existing global hybrids by using a fraction of the exchange-correlation energy in the strong-correlation limit to replace an equal fraction of the semi-local approximation to the exchange-correlation energy in the strong-correlation limit. The performance of the proposed approximations is evaluated for molecular atomization energies, total atomic energies, and ionization potentials
... ovary syndrome. Read our information on PCOS for teens , and see your doctor if you think you may have PCOS. Major weight loss. Girls who have anorexia will often stop having periods. When to see ...
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Chimento, Luis P.; Richarte, Martin G. [Universidad de Buenos Aires, IFIBA, CONICET, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina); Forte, Monica [Universidad de Buenos Aires, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina)
2013-01-15
We examine a Friedmann-Robertson-Walker universe filled with interacting dark matter, modified holographic Ricci dark energy (MHRDE), and a decoupled baryonic component. The estimations of the cosmic parameters with Hubble data lead to an age of the universe of 13.17 Gyr and show that the MHRDE is free from the cosmic-age problem at low redshift (0{<=}z{<=}2) in contrast to holographic Ricci dark energy (HRDE) case. We constrain the parameters with the Union2 data set and contrast with the Hubble data. We also study the behavior of dark energy at early times by taking into account the severe bounds found at recombination era and/or at big bang nucleosynthesis. The inclusion of a non-interacting baryonic matter forces that the amount of dark energy at z{sub t} {proportional_to} O(1) changes abruptly implying that {Omega} {sub x} (z {approx_equal}1100)=0.03, so the bounds reported by the forecast of Planck and CMBPol experiments are more favored for the MHRDE model than in the case of HRDE cutoff. For the former model, we also find that at high redshift the fraction of dark energy varies from 0.006 to 0.002, then the amount of {Omega} {sub x} at the big bang nucleosynthesis era does not disturb the observed helium abundance in the universe provided that the bound {Omega} {sub x} (z {approx_equal}10 {sup 10}) <0.21 is hold. (orig.)
Klep, Annefloor; Wisse, Barbara; Van Der Flier, Henk
This study explores whether the dynamic path to group affect, which is characterized by interactive affective sharing processes, yields different effects on task performance and group dynamics than the static path to group affect, which arises from non-interactive affective sharing. The results of
Klep, A.H.M.; Wisse, B.M.; van der Flier, H.
2011-01-01
This study explores whether the dynamic path to group affect, which is characterized by interactive affective sharing processes, yields different effects on task performance and group dynamics than the static path to group affect, which arises from non-interactive affective sharing. The results of
The period-age relation for cepheids
International Nuclear Information System (INIS)
Efremov, Yu.N.
1978-01-01
The list of 119 cepheid-members of 55 clusters and associations of the Magellanic Clouds, the Galaxy, and M31 is given. The period-age relation is found from the data on 64 cepheids in 29 clusters for which the age determinations are available, the ages of extragalactic clusters were determined mainly from their integral colours. The U-B colours are found to be of much better age parameters than the B-V ones. The composite period-age relation agrees well with the theoretical one. The observed dispersion of the period-age relation leads to an estimate of the age dispersion about 1x10 7 years in the associations. Some peculiarities of the cepheids with the shortest periods amongst others in the same clusters are probably explained if they are overtone pulsators. The period-age relation may be used for an investigation of the recent history of star formation in the galaxies. This relation allows to determine the age gradient across the spiral arm in M31 which is in agreement with the density wave theory predictions. The distribution of cepheids in our Galaxy and neighbouring galaxies is consistent with the conception of star formation lasting for some dozen million years in cells with a dimension of some hundreds of parsecs
Mann, Dwayne L; Edwards, Bradley A; Joosten, Simon A; Hamilton, Garun S; Landry, Shane; Sands, Scott A; Wilson, Stephen J; Terrill, Philip I
2017-10-01
Short pauses or "transition-periods" at the end of expiration and prior to subsequent inspiration are commonly observed during sleep in humans. However, the role of transition periods in regulating ventilation during physiological challenges such as partial airway obstruction (PAO) has not been investigated. Twenty-nine obstructive sleep apnea patients and eight controls underwent overnight polysomnography with an epiglottic catheter. Sustained-PAO segments (increased epiglottic pressure over ≥5 breaths without increased peak inspiratory flow) and unobstructed reference segments were manually scored during apnea-free non-REM sleep. Nasal pressure data was computationally segmented into inspiratory (T I , shortest period achieving 95% inspiratory volume), expiratory (T E , shortest period achieving 95% expiratory volume), and inter-breath transition period (T Trans , period between T E and subsequent T I ). Compared with reference segments, sustained-PAO segments had a mean relative reduction in T Trans (-24.7±17.6%, P<0.001), elevated T I (11.8±10.5%, P<0.001), and a small reduction in T E (-3.9±8.0, P≤0.05). Compensatory increases in inspiratory period during PAO are primarily explained by reduced transition period and not by reduced expiratory period. Copyright © 2017 Elsevier B.V. All rights reserved.
Smith, K; Abasolo, Daniel Emilio; Escudero, J
2016-01-01
The Cluster-Span Threshold (CST) is a recently introduced unbiased threshold for functional connectivity networks. This binarisation technique offers a natural trade-off of sparsity and density of information by balancing the ratio of closed to open triples in the network topology. Here we present findings comparing it with the Union of Shortest Paths (USP), another recently proposed objective method. We analyse standard network metrics of binarised networks for sensitivity to clinical Alzhei...
Long-Period Tidal Variations in the Length of Day
Ray, Richard D.; Erofeeva, Svetlana Y.
2014-01-01
A new model of long-period tidal variations in length of day is developed. The model comprises 80 spectral lines with periods between 18.6 years and 4.7 days, and it consistently includes effects of mantle anelasticity and dynamic ocean tides for all lines. The anelastic properties followWahr and Bergen; experimental confirmation for their results now exists at the fortnightly period, but there remains uncertainty when extrapolating to the longest periods. The ocean modeling builds on recent work with the fortnightly constituent, which suggests that oceanic tidal angular momentum can be reliably predicted at these periods without data assimilation. This is a critical property when modeling most long-period tides, for which little observational data exist. Dynamic ocean effects are quite pronounced at shortest periods as out-of-phase rotation components become nearly as large as in-phase components. The model is tested against a 20 year time series of space geodetic measurements of length of day. The current international standard model is shown to leave significant residual tidal energy, and the new model is found to mostly eliminate that energy, with especially large variance reduction for constituents Sa, Ssa, Mf, and Mt.
Evolution of periodicity in periodical cicadas.
Ito, Hiromu; Kakishima, Satoshi; Uehara, Takashi; Morita, Satoru; Koyama, Takuya; Sota, Teiji; Cooley, John R; Yoshimura, Jin
2015-09-14
Periodical cicadas (Magicicada spp.) in the USA are famous for their unique prime-numbered life cycles of 13 and 17 years and their nearly perfectly synchronized mass emergences. Because almost all known species of cicada are non-periodical, periodicity is assumed to be a derived state. A leading hypothesis for the evolution of periodicity in Magicicada implicates the decline in average temperature during glacial periods. During the evolution of periodicity, the determinant of maturation in ancestral cicadas is hypothesized to have switched from size dependence to time (period) dependence. The selection for the prime-numbered cycles should have taken place only after the fixation of periodicity. Here, we build an individual-based model of cicadas under conditions of climatic cooling to explore the fixation of periodicity. In our model, under cold environments, extremely long juvenile stages lead to extremely low adult densities, limiting mating opportunities and favouring the evolution of synchronized emergence. Our results indicate that these changes, which were triggered by glacial cooling, could have led to the fixation of periodicity in the non-periodical ancestors.
The period between exfoliation of primary teeth and the emergence of permanent successors.
Nyström, M; Peck, L
1989-02-01
The dates of natural exfoliation of primary teeth and of clinical eruption of their successors were recorded in 141 children, a total of 660 teeth. The aim of this investigation was to study the length of the period between these two developmental events. In the mandible, the mean length of the toothless period for the central incisor was 2 weeks and that for the lateral incisors and canines 6 weeks. In the maxilla, the corresponding period was 6 weeks for the central incisor and over 4 months for the lateral incisor and the canine. The mean length of the toothless period was shortest, 0-6 days, between the primary molars and the succeeding premolars. Individual variation was great. No difference was detected between the sexes. In some cases the length of the toothless period for the maxillary lateral incisors and for the canines in both jaws exceeded one year. This was associated with crowding, which caused the premature loss of primary teeth.
A survey for very short-period planets in the Kepler data
Energy Technology Data Exchange (ETDEWEB)
Jackson, Brian; Stark, Christopher C.; Chambers, John [Carnegie Institution for Science, 5241 Broad Branch Road NW, Washington, DC 20015 (United States); Adams, Elisabeth R. [Planetary Science Institute, 1700 East Fort Lowell, Suite 106, Tucson, AZ 85719 (United States); Deming, Drake, E-mail: bjackson@dtm.ciw.edu [Department of Astronomy, University of Maryland at College Park, College Park, MD 20742 (United States)
2013-12-20
We conducted a search for very short-period transiting objects in the publicly available Kepler data set. Our preliminary survey has revealed four planetary candidates, all with orbital periods less than 12 hr. We have analyzed the data for these candidates using photometric models that include transit light curves, ellipsoidal variations, and secondary eclipses to constrain the candidates' radii, masses, and effective temperatures. Even with masses of only a few Earth masses, the candidates' short periods mean that they may induce stellar radial velocity signals (a few m s{sup –1}) detectable by currently operating facilities. The origins of such short-period planets are unclear, but we discuss the possibility that they may be the remnants of disrupted hot Jupiters. Whatever their origins, if confirmed as planets, these candidates would be among the shortest-period planets ever discovered. Such planets would be particularly amenable to discovery by the planned TESS mission.
A survey for very short-period planets in the Kepler data
International Nuclear Information System (INIS)
Jackson, Brian; Stark, Christopher C.; Chambers, John; Adams, Elisabeth R.; Deming, Drake
2013-01-01
We conducted a search for very short-period transiting objects in the publicly available Kepler data set. Our preliminary survey has revealed four planetary candidates, all with orbital periods less than 12 hr. We have analyzed the data for these candidates using photometric models that include transit light curves, ellipsoidal variations, and secondary eclipses to constrain the candidates' radii, masses, and effective temperatures. Even with masses of only a few Earth masses, the candidates' short periods mean that they may induce stellar radial velocity signals (a few m s –1 ) detectable by currently operating facilities. The origins of such short-period planets are unclear, but we discuss the possibility that they may be the remnants of disrupted hot Jupiters. Whatever their origins, if confirmed as planets, these candidates would be among the shortest-period planets ever discovered. Such planets would be particularly amenable to discovery by the planned TESS mission.
Directory of Open Access Journals (Sweden)
V. E. Podol'skii
2015-01-01
Full Text Available The paper considers the implementing Bellman-Ford and Lee algorithms to find the shortest graph path on a computer system with multiple instruction stream and single data stream (MISD. The MISD computer is a computer that executes commands of arithmetic-logical processing (on the CPU and commands of structures processing (on the structures processor in parallel on a single data stream. Transformation of sequential programs into the MISD programs is a labor intensity process because it requires a stream of the arithmetic-logical processing to be manually separated from that of the structures processing. Algorithms based on the processing of data structures (e.g., algorithms on graphs show high performance on a MISD computer. Bellman-Ford and Lee algorithms for finding the shortest path on a graph are representatives of these algorithms. They are applied to robotics for automatic planning of the robot movement in-situ. Modification of Bellman-Ford and Lee algorithms for finding the shortest graph path in coprocessor MISD mode and the parallel MISD modification of these algorithms were first obtained in this article. Thus, this article continues a series of studies on the transformation of sequential algorithms into MISD ones (Dijkstra and Ford-Fulkerson 's algorithms and has a pronouncedly applied nature. The article also presents the analysis results of Bellman-Ford and Lee algorithms in MISD mode. The paper formulates the basic trends of a technique for parallelization of algorithms into arithmetic-logical processing stream and structures processing stream. Among the key areas for future research, development of the mathematical approach to provide a subsequently formalized and automated process of parallelizing sequential algorithms between the CPU and structures processor is highlighted. Among the mathematical models that can be used in future studies there are graph models of algorithms (e.g., dependency graph of a program. Due to the high
Energy Technology Data Exchange (ETDEWEB)
Burton, J. R.; Watson, C. A.; Fitzsimmons, A.; Moulds, V. [Astrophysics Research Centre, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Pollacco, D.; Wheatley, P. J. [Department of Physics and Astronomy, University of Warwick, Coventry CV4 7AL (United Kingdom); Littlefair, S. P., E-mail: jburton04@qub.ac.uk [Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH (United Kingdom)
2014-07-10
The close proximity of short-period hot-Jupiters to their parent star means they are subject to extreme tidal forces. This has a profound effect on their structure and, as a result, density measurements that assume that the planet is spherical can be incorrect. We have simulated the tidally distorted surface for 34 known short-period hot-Jupiters, assuming surfaces of constant gravitational equipotential for the planet, and the resulting densities have been calculated based only on observed parameters of the exoplanet systems. Comparing these results to the density values, assuming the planets are spherical, shows that there is an appreciable change in the measured density for planets with very short periods (typically less than two days). For one of the shortest-period systems, WASP-19b, we determine a decrease in bulk density of 12% from the spherical case and, for the majority of systems in this study, this value is in the range of 1%-5%. On the other hand, we also find cases where the distortion is negligible (relative to the measurement errors on the planetary parameters) even in the cases of some very short period systems, depending on the mass ratio and planetary radius. For high-density gas planets requiring apparently anomalously large core masses, density corrections due to tidal deformation could become important for the shortest-period systems.
Hennigan, Jennifer N.; Grubbs, W. Tandy
2013-01-01
The chemical elements present in the modern periodic table are arranged in terms of atomic numbers and chemical periodicity. Periodicity arises from quantum mechanical limitations on how many electrons can occupy various shells and subshells of an atom. The shell model of the atom predicts that a maximum of 2, 8, 18, and 32 electrons can occupy…
Ettelt, Harold J.
All recent issues of periodicals found which contain indexed book reviews are listed in this compilation from Drake Memorial Library at the New York State University at Brockport. The periodicals are listed by 29 subject headings in this informal guide designed to be used at Drake Library. The number of reviews in the periodical in a recent year…
Menstruation - painful; Dysmenorrhea; Periods - painful; Cramps - menstrual; Menstrual cramps ... into two groups, depending on the cause: Primary dysmenorrhea Secondary dysmenorrhea Primary dysmenorrhea is menstrual pain that ...
DEFF Research Database (Denmark)
Sarri, Kalliopi
1999-01-01
and their quality was improved considerably toward the end of this period. The profound cultural innovations of the Middle Helladic period were initially interpreted as a result of violent population movement and troubles provoked by the coming of the first Indo-European races. However, this matter does no more...... Helladic period is considered as a period of economic and social decline it was the time during which the mainland features merged with the insular influence, that is all the Aegean elements which led to the creation of the Mycenaean civilization were mixed in a creative way....
DEFF Research Database (Denmark)
Sorokin, Sergey V.
2015-01-01
The talk is concerned with the modelling of wave propagation in and vibration of periodic elastic structures. Although analysis of wave-guide properties of infinite periodic structures is a well establish research subject, some issues have not yet been fully addressed in the literature. The aim o...
Nahlik, Mary Schrodt
2005-01-01
To help make the abstract world of chemistry more concrete eighth-grade students, the author has them create a living periodic table that can be displayed in the classroom or hallway. This display includes information about the elements arranged in the traditional periodic table format, but also includes visual real-world representations of the…
Huber, Annette
2017-01-01
This book casts the theory of periods of algebraic varieties in the natural setting of Madhav Nori’s abelian category of mixed motives. It develops Nori’s approach to mixed motives from scratch, thereby filling an important gap in the literature, and then explains the connection of mixed motives to periods, including a detailed account of the theory of period numbers in the sense of Kontsevich-Zagier and their structural properties. Period numbers are central to number theory and algebraic geometry, and also play an important role in other fields such as mathematical physics. There are long-standing conjectures about their transcendence properties, best understood in the language of cohomology of algebraic varieties or, more generally, motives. Readers of this book will discover that Nori’s unconditional construction of an abelian category of motives (over fields embeddable into the complex numbers) is particularly well suited for this purpose. Notably, Kontsevich's formal period algebra represents a to...
Directory of Open Access Journals (Sweden)
Carlos A. Berenstein
1980-01-01
Full Text Available We show that any mean-periodic function f can be represented in terms of exponential-polynomial solutions of the same convolution equation f satisfies, i.e., u∗f=0(μ∈E′(ℝn. This extends to n-variables the work of L. Schwartz on mean-periodicity and also extends L. Ehrenpreis' work on partial differential equations with constant coefficients to arbitrary convolutors. We also answer a number of open questions about mean-periodic functions of one variable. The basic ingredient is our work on interpolation by entire functions in one and several complex variables.
On Finding Shortest Paths on Convex Polyhedra.
1985-05-01
versi ty of N laryhrid ml Collge :IJR-. M T) 207-12 COMPUTER SCIENCE TECHNICAL REPR SERWS .UE TE UNIVERSITY OF MARYLAND COLLEGE PARK, MARYLAND S 20742...planar layout can be physically interpreted as cutting the polyhedron along the ridges and unfolding the resulting object onto the plane. o% 4e.. ~16 A o
Approximate Shortest Homotopic Paths in Weighted Regions
Cheng, Siu-Wing; Jin, Jiongxin; Vigneron, Antoine; Wang, Yajun
2010-01-01
Let P be a path between two points s and t in a polygonal subdivision T with obstacles and weighted regions. Given a relative error tolerance ε ∈(0,1), we present the first algorithm to compute a path between s and t that can be deformed to P
Approximate Shortest Homotopic Paths in Weighted Regions
Cheng, Siu-Wing
2010-01-01
Let P be a path between two points s and t in a polygonal subdivision T with obstacles and weighted regions. Given a relative error tolerance ε ∈(0,1), we present the first algorithm to compute a path between s and t that can be deformed to P without passing over any obstacle and the path cost is within a factor 1 + ε of the optimum. The running time is O(h 3/ε2 kn polylog(k, n, 1/ε)), where k is the number of segments in P and h and n are the numbers of obstacles and vertices in T, respectively. The constant in the running time of our algorithm depends on some geometric parameters and the ratio of the maximum region weight to the minimum region weight. © 2010 Springer-Verlag.
Approximate shortest homotopic paths in weighted regions
Cheng, Siuwing
2012-02-01
A path P between two points s and t in a polygonal subdivision T with obstacles and weighted regions defines a class of paths that can be deformed to P without passing over any obstacle. We present the first algorithm that, given P and a relative error tolerance ε (0, 1), computes a path from this class with cost at most 1 + ε times the optimum. The running time is O(h 3/ε 2kn polylog (k,n,1/ε)), where k is the number of segments in P and h and n are the numbers of obstacles and vertices in T, respectively. The constant in the running time of our algorithm depends on some geometric parameters and the ratio of the maximum region weight to the minimum region weight. © 2012 World Scientific Publishing Company.
Shortest-paths preserving metro maps
Milea, T.Y.; Schrijvers, O.J.; Buchin, K.; Haverkort, H.J.; Kreveld, van M.J.; Speckmann, B.
2012-01-01
A metro map, or subway map, is a schematic representation of a metro system of a city. The main goal of a metro map is to provide a traveler with information on which lines to take to get from station A to station B, and at which stations he needs to switch lines. It is often not beneficial to use
Bad Luck When Joining the Shortest Queue
Blanc, J.P.C.
2008-01-01
A frequent observation in service systems with queues in parallel is that customers in other queues tend to be served faster than those in one’s own queue. This paper quantifies the probability that one’s service would have started earlier if one had joined another queue than the queue that was
Approximate shortest homotopic paths in weighted regions
Cheng, Siuwing; Jin, Jiongxin; Vigneron, Antoine E.; Wang, Yajun
2012-01-01
A path P between two points s and t in a polygonal subdivision T with obstacles and weighted regions defines a class of paths that can be deformed to P without passing over any obstacle. We present the first algorithm that, given P and a relative
Painful periods (dysmenorrhea) (image)
Primary dysmenorrhea is a normal cramping of the lower abdomen caused by hormone-induced uterine contractions before the period. Secondary dysmenorrhea may be caused by abnormal conditions such as ...
Vaginal bleeding between periods
... this page: //medlineplus.gov/ency/article/003156.htm Vaginal bleeding between periods To use the sharing features ... this page, please enable JavaScript. This article discusses vaginal bleeding that occurs between a woman's monthly menstrual ...
Hasan, Mohammd; Mandal, Bhabani Prasad
2018-04-01
In this paper we introduce the concept of super periodic potential (SPP) of arbitrary order n, n ∈I+, in one dimension. General theory of wave propagation through SPP of order n is presented and the reflection and transmission coefficients are derived in their closed analytical form by transfer matrix formulation. We present scattering features of super periodic rectangular potential and super periodic delta potential as special cases of SPP. It is found that the symmetric self-similarity is the special case of super periodicity. Thus by identifying a symmetric fractal potential as special cases of SPP, one can obtain the tunnelling amplitude for a particle from such fractal potential. By using the formalism of SPP we obtain the close form expression of tunnelling amplitude of a particle for general Cantor and Smith-Volterra-Cantor potentials.
International Nuclear Information System (INIS)
Huffman, F.C.
1978-01-01
The lead time for executing the Adjustable Fixed-Commitment (AFC) contract and exceptions which may be considered are discussed. The initial delivery period is also discussed. Delays, deferrals, and schedule adjustment charges are finally considered
Banks, Alton J.; Holmes, Jon L.
1995-01-01
Describes the characteristics of the digitized version of The Periodic Table Videodisc. Provides details about the organization of information and access to the data via Macintosh and Windows computers. (DDR)
Saturnelli, Annette
1985-01-01
Examines problems resulting from different forms of the periodic table, indicating that New York State schools use a form reflecting the International Union of Pure and Applied Chemistry's 1984 recommendations. Other formats used and reasons for standardization are discussed. (DH)
Supersymmetrically transformed periodic potentials
C, David J. Fernandez
2003-01-01
The higher order supersymmetric partners of a stationary periodic potential are studied. The transformation functions associated to the band edges do not change the spectral structure. However, when the transformation is implemented for factorization energies inside of the forbidden bands, the final potential will have again the initial band structure but it can have bound states encrusted into the gaps, giving place to localized periodicity defects.
Rojith Karandode Balakrishnan; Suresh Rama Chandran; Geetha Thirumalnesan; Nedumaran Doraisamy
2011-01-01
This article aims at highlighting the importance of suspecting thyrotoxicosis in cases of recurrent periodic flaccid paralysis; especially in Asian men to facilitate early diagnosis of the former condition. A case report of a 28 year old male patient with recurrent periodic flaccid paralysis has been presented. Hypokalemia secondary to thyrotoxicosis was diagnosed as the cause of the paralysis. The patient was given oral potassium intervention over 24 hours. The patient showed complete recove...
Role of short periodic orbits in quantum maps with continuous openings
Prado, Carlos A.; Carlo, Gabriel G.; Benito, R. M.; Borondo, F.
2018-04-01
We apply a recently developed semiclassical theory of short periodic orbits to the continuously open quantum tribaker map. In this paradigmatic system the trajectories are partially bounced back according to continuous reflectivity functions. This is relevant in many situations that include optical microresonators and more complicated boundary conditions. In a perturbative regime, the shortest periodic orbits belonging to the classical repeller of the open map—a cantor set given by a region of exactly zero reflectivity—prove to be extremely robust in supporting a set of long-lived resonances of the continuously open quantum maps. Moreover, for steplike functions a significant reduction in the number needed is obtained, similarly to the completely open situation. This happens despite a strong change in the spectral properties when compared to the discontinuous reflectivity case. In order to give a more realistic interpretation of these results we compare with a Fresnel-type reflectivity function.
International Nuclear Information System (INIS)
Udovskij, A.L.; Karpushkin, V.N.; Nikishina, E.A.
1991-01-01
Method of non-interacting thermodynamic calculation of state diagram of binary systems contacting p disordered phases with variable composition and q phases with constant composition for (p, q) ≤ 10 case is developed. Determination of all possible solutions of phase equilibrium equations is realized in the method. Certain application examples of computer-realized method of T-x thermodynamic calculation using PC for Cr-W, Ni-W, Ni-Al, Ni-Re binary systems are given
International Nuclear Information System (INIS)
Fluck, E.; Heumann, K.G.
1985-01-01
Following a recommendation by the International Union for Pure and Applied Chemistry (IUPAC), the groups of the periodic table shall be numbered from 1 to 18, instead of I to VIII as before. The recommendations has been approved of by the Committee on Nomenclature of the American Chemical Society. The new system abandons the distinction between main groups (a) and auxiliary groups (b), which in the past frequently has been the reason for misunderstandings between European and American chemists, due to different handling. The publishing house VCH Verlagsgesellschaft recently produced a new periodic table that shows the old and the new numbering system together at a glance, so that chemists will have time to get familiar with the new system. In addition the new periodic table represents an extensive data compilation arranged by elements. The front page lists the chemical properties of elements, the back page their physical properties. (orig./EF) [de
Directory of Open Access Journals (Sweden)
Rojith Karandode Balakrishnan
2011-01-01
Full Text Available This article aims at highlighting the importance of suspecting thyrotoxicosis in cases of recurrent periodic flaccid paralysis; especially in Asian men to facilitate early diagnosis of the former condition. A case report of a 28 year old male patient with recurrent periodic flaccid paralysis has been presented. Hypokalemia secondary to thyrotoxicosis was diagnosed as the cause of the paralysis. The patient was given oral potassium intervention over 24 hours. The patient showed complete recovery after the medical intervention and was discharged after 24 hours with no residual paralysis. Thyrotoxic periodic paralysis (TPP is a complication of thyrotoxicosis, more common amongst males in Asia. It presents as acute flaccid paralysis in a case of hyperthyroidism with associated hypokalemia. The features of thyrotoxicosis may be subtle or absent. Thus, in cases of recurrent or acute flaccid muscle paralysis, it is important to consider thyrotoxicosis as one of the possible causes, and take measures accordingly.
Hon, Nick K.; Tsia, Kevin K.; Solli, Daniel R.; Khurgin, Jacob B.; Jalali, Bahram
2010-02-01
Bulk centrosymmetric silicon lacks second-order optical nonlinearity χ(2) - a foundational component of nonlinear optics. Here, we propose a new class of photonic device which enables χ(2) as well as quasi-phase matching based on periodic stress fields in silicon - periodically-poled silicon (PePSi). This concept adds the periodic poling capability to silicon photonics, and allows the excellent crystal quality and advanced manufacturing capabilities of silicon to be harnessed for devices based on χ(2)) effects. The concept can also be simply achieved by having periodic arrangement of stressed thin films along a silicon waveguide. As an example of the utility, we present simulations showing that mid-wave infrared radiation can be efficiently generated through difference frequency generation from near-infrared with a conversion efficiency of 50% based on χ(2) values measurements for strained silicon reported in the literature [Jacobson et al. Nature 441, 199 (2006)]. The use of PePSi for frequency conversion can also be extended to terahertz generation. With integrated piezoelectric material, dynamically control of χ(2)nonlinearity in PePSi waveguide may also be achieved. The successful realization of PePSi based devices depends on the strength of the stress induced χ(2) in silicon. Presently, there exists a significant discrepancy in the literature between the theoretical and experimentally measured values. We present a simple theoretical model that produces result consistent with prior theoretical works and use this model to identify possible reasons for this discrepancy.
Hereditary periodic fever syndromes
McDermott, MF; Frenkel, J
Hereditary periodic fever syndromes are defined by recurrent attacks of generalised inflammation for which no infectious or auto-immune cause can be identified. For most of these disorders, the molecular basis has recently been elucidated. This has opened the prospect of novel therapeutic
Almost periodic Schroedinger operators
International Nuclear Information System (INIS)
Bellissard, J.; Lima, R.
1984-01-01
These lectures are devoted to recent developments in the theory of almost-periodic Schroedinger Operators. We specially describe the algebraic point of view, with applications to gap-labelling theorems. Particular models are also presented which exhibit various spectral properties. (orig.)
Astrophysical implications of periodicity
International Nuclear Information System (INIS)
Muller, R.A.
1988-01-01
Two remarkable discoveries of the last decade have profound implications for astrophysics and for geophysics. These are the discovery by Alvarez et al., that certain mass extinctions are caused by the impact on the earth of a large asteroid or comet, and the discovery by Raup and Sepkoski that such extinctions are periodic, with a cycle time of 26 to 30 million years. The validity of both of these discoveries is assumed and the implications are examined. Most of the phenomena described depend not on periodicity, but just on the weaker assumption that the impacts on the earth take place primarily in showers. Proposed explanations for the periodicity include galactic oscillations, the Planet X model, and the possibility of Nemesis, a solar companion star. These hypotheses are critically examined. Results of the search for the solar companion are reported. The Deccan flood basalts of India have been proposed as the impact site for the Cretaceous impact, but this hypotheisis is in contradiction with the conclusion of Courtillot et al., that the magma flow began during a period of normal magnetic field. A possible resolution of this contradiction is proposed
Johnson, Mike
1998-01-01
Presents an exercise in which an eighth-grade science teacher decorated the classroom with a periodic table of students. Student photographs were arranged according to similarities into vertical columns. Students were each assigned an atomic number according to their placement in the table. The table is then used to teach students about…
Herrenden-Harker, B. D.
1997-01-01
Presents a modern Periodic Table based on the electron distribution in the outermost shell and the order of filling of the sublevels within the shells. Enables a student to read off directly the electronic configuration of the element and the order in which filling occurs. (JRH)
International Nuclear Information System (INIS)
Ferreiro, J.E.; Arguelles, D.J.; Rams, H. Jr.
1986-01-01
A case of thyrotoxic periodic paralysis is reported in a Hispanic man with an unusual recurrence six weeks after radioactive iodine treatment. Thyrotoxic periodic paralysis has now been well characterized in the literature: it occurs primarily in Orientals with an overwhelming male preponderance and a higher association of specific HLA antigens. Clinical manifestations include onset after high carbohydrate ingestion or heavy exertion, with progressive symmetric weakness leading to flaccid paralysis of the extremities and other muscle groups, lasting several hours. If hypokalemia is present, potassium administration may help abort the attack. Although propranolol can be efficacious in preventing further episodes, the only definitive treatment is establishing a euthyroid state. The pathophysiology is still controversial, but reflects altered potassium and calcium dynamics as well as certain morphologic characteristics within the muscle unit itself
Polysheroidal periodic functions
International Nuclear Information System (INIS)
Truskova, N.F.
1985-01-01
Separation of variables in the Helmholtz N-dimensional (N≥4) equation in polyspheroidal coordinate systems leads to the necessity of solving equations going over into equations for polyspheroidal periodic functions used for solving the two-centre problem in quantum mechanics, the three-body problem with Coulomb interaction, etc. For these functions the expansions are derived in terms of the Jacobi polynomials and Bessel functions. Their basic properties, asymptotics are considered. The algorithm of their computer calculations is developed. The results of numerical calculations are given
Deciphering Periodic Methanol Masers
Stecklum, Bringfried; Caratti o Garatti, Alessio; Henning, Thomas; Hodapp, Klaus; Hopp, Ulrich; Kraus, Alex; Linz, Hendrik; Sanna, Alberto; Sobolev, Andrej; Wolf, Verena
2018-05-01
Impressive progress has been made in recent years on massive star formation, yet the involved high optical depths even at submm/mm wavelengths make it difficult to reveal its details. Recently, accretion bursts of massive YSOs have been identified to cause flares of Class II methanol masers (methanol masers for short) due to enhanced mid-IR pumping. This opens a new window to protostellar accretion variability, and implies that periodic methanol masers hint at cyclic accretion. Pinning down the cause of the periodicity requires joint IR and radio monitoring. We derived the first IR light curve of a periodic maser host from NEOWISE data. The source, G107.298+5.639, is an intermediate-mass YSO hosting methanol and water masers which flare every 34.5 days. Our recent joint K-band and radio observations yielded first but marginal evidence for a phase lag between the rise of IR and maser emission, respectively, and revealed that both NEOWISE and K-band light curves are strongly affected by the light echo from the ambient dust. Both the superior resolution of IRAC over NEOWISE and the longer wavelengths compared to our ground-based imaging are required to inhibit the distractive contamination by the light echo. Thus, we ask for IRAC monitoring of G107 to cover one flare cycle, in tandem with 100-m Effelsberg and 2-m Wendelstein radio and NIR observations to obtain the first high-quality synoptic measurements of this kind of sources. The IR-maser phase lag, the intrinsic shape of the IR light curves and their possible color variation during the cycle allow us to constrain models for the periodic maser excitation. Since methanol masers are signposts of intermediate-mass and massive YSOs, deciphering their variability offers a clue to the dynamics of the accretion-mediated growth of massive stars and their feedback onto the immediate natal environment. The Spitzer light curve of such a maser-hosting YSO would be a legacy science product of the mission.
Effects of age, gender, and stimulus presentation period on visual short-term memory.
Kunimi, Mitsunobu
2016-01-01
This study focused on age-related changes in visual short-term memory using visual stimuli that did not allow verbal encoding. Experiment 1 examined the effects of age and the length of the stimulus presentation period on visual short-term memory function. Experiment 2 examined the effects of age, gender, and the length of the stimulus presentation period on visual short-term memory function. The worst memory performance and the largest performance difference between the age groups were observed in the shortest stimulus presentation period conditions. The performance difference between the age groups became smaller as the stimulus presentation period became longer; however, it did not completely disappear. Although gender did not have a significant effect on d' regardless of the presentation period in the young group, a significant gender-based difference was observed for stimulus presentation periods of 500 ms and 1,000 ms in the older group. This study indicates that the decline in visual short-term memory observed in the older group is due to the interaction of several factors.
The Properties of Long Period Variables in the LMC from MACHO
Energy Technology Data Exchange (ETDEWEB)
Fraser, O J; Hawley, S L; Cook, K H
2008-05-06
We present a new analysis of the long period variables in the Large Magellanic Cloud from the MACHO Variable Star Catalog. Three-quarters of our sample of evolved, variable stars have periodic light curves. We characterize the stars in our sample using the multiple periods found in their frequency spectra. Additionally, we use single-epoch 2MASS measurements to construct the average infrared light curves for different groups of these stars. Comparison with evolutionary models shows that stars on the RGB or the Early AGB often show non-periodic variability, but begin to pulsate with periods on the two shortest period-luminosity sequences (1 & 2) when they brighten to K{sub s} {approx} 13. The stars on the Thermally Pulsing AGB are more likely to pulsate with longer periods that lie on the next two P-L sequences (3 & 4), including the sequence associated with the Miras in the LMC. The Petersen diagram and its variants show that multi-periodic stars on each pair of these sequences (3 & 4, and 1 & 2), typically pulsate with periods associated only with that pair. The periods in these multi-periodic stars become longer and stronger as the star evolves. We further constrain the mechanism behind the long secondary periods (LSPs) seen in half of our sample, and find that there is a close match between the luminosity functions of the LSP stars and all of the stars in our sample, and that these star's pulsation amplitudes are relatively wavelength independent. Although this is characteristic of stellar multiplicity, the large number of these variables is problematic for that explanation.
Periodically modulated dark states
Han, Yingying; Zhang, Jun; Zhang, Wenxian
2018-04-01
Phenomena of electromagnetically induced transparency (PEIT) may be interpreted by the Autler-Townes Splitting (ATS), where the coupled states are split by the coupling laser field, or by the quantum destructive interference (QDI), where the atomic phases caused by the coupling laser and the probe laser field cancel. We propose modulated experiments to explore the PEIT in an alternative way by periodically modulating the coupling and the probe fields in a Λ-type three-level system initially in a dark state. Our analytical and numerical results rule out the ATS interpretation and show that the QDI interpretation is more appropriate for the modulated experiments. Interestingly, dark state persists in the double-modulation situation where control and probe fields never occur simultaneously, which is significant difference from the traditional dark state condition. The proposed experiments are readily implemented in atomic gases, artificial atoms in superconducting quantum devices, or three-level meta-atoms in meta-materials.
[Childhood periodic syndromes].
Cuvellier, J-C; Lépine, A
2010-01-01
This review focuses on the so-called "periodic syndromes of childhood that are precursors to migraine", as included in the Second Edition of the International Classification of Headache Disorders. Three periodic syndromes of childhood are included in the Second Edition of the International Classification of Headache Disorders: abdominal migraine, cyclic vomiting syndrome and benign paroxysmal vertigo, and a fourth, benign paroxysmal torticollis is presented in the Appendix. The key clinical features of this group of disorders are the episodic pattern and intervals of complete health. Episodes of benign paroxysmal torticollis begin between 2 and 8 months of age. Attacks are characterized by an abnormal inclination and/or rotation of the head to one side, due to cervical dystonia. They usually resolve by 5 years. Benign paroxysmal vertigo presents as sudden attacks of vertigo, accompanied by inability to stand without support, and lasting seconds to minutes. Age at onset is between 2 and 4 years, and the symptoms disappear by the age of 5. Cyclic vomiting syndrome is characterized in young infants and children by repeated stereotyped episodes of pernicious vomiting, at times to the point of dehydration, and impacting quality of life. Mean age of onset is 5 years. Abdominal migraine remains a controversial issue and presents in childhood with repeated stereotyped episodes of unexplained abdominal pain, nausea and vomiting occurring in the absence of headache. Mean age of onset is 7 years. Both cyclic vomiting syndrome and abdominal migraine are noted for the absence of pathognomonic clinical features but also for the large number of other conditions to be considered in their differential diagnoses. Diagnostic criteria, such as those of the Second Edition of the International Classification of Headache Disorders and the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition, have made diagnostic approach and management easier. Their diagnosis
Nonparametric Inference for Periodic Sequences
Sun, Ying; Hart, Jeffrey D.; Genton, Marc G.
2012-01-01
the periodogram, a widely used tool for period estimation. The CV method is computationally simple and implicitly penalizes multiples of the smallest period, leading to a "virtually" consistent estimator of integer periods. This estimator is investigated both
Testing periodically integrated autoregressive models
Ph.H.B.F. Franses (Philip Hans); M.J. McAleer (Michael)
1997-01-01
textabstractPeriodically integrated time series require a periodic differencing filter to remove the stochastic trend. A non-periodic integrated time series needs the first-difference filter for similar reasons. When the changing seasonal fluctuations for the non-periodic integrated series can be
Pulse periods and the long-term variations of the X-ray pulsars VELA X-1 and Centaurus X-3
Tsunemi, Hiroshi
The paper reports recent determinations of the pulse period for two X-ray pulsars, Vela X-1 and Cen X-3, made in 1987 with the All Sky Monitor (ASM) on board the Ginga satellite. The heliocentric pulse periods are 283.09 + or - 0.01 s and 4.8229 + or - 0.0001 s, respectively. These are the longest and shortest values in their respective observational histories. The random walk model for the Vela X-1 pulsar can explain this result as well as those obtained previously. It is also noted that the pulse-period change for the Cen X-3 system shows a 9-yr periodicity. This is probably due to the activity of the companion star rather than to Doppler-shift variations due to a third body or the precession of the neutron star.
Periodic feedback stabilization for linear periodic evolution equations
Wang, Gengsheng
2016-01-01
This book introduces a number of recent advances regarding periodic feedback stabilization for linear and time periodic evolution equations. First, it presents selected connections between linear quadratic optimal control theory and feedback stabilization theory for linear periodic evolution equations. Secondly, it identifies several criteria for the periodic feedback stabilization from the perspective of geometry, algebra and analyses respectively. Next, it describes several ways to design periodic feedback laws. Lastly, the book introduces readers to key methods for designing the control machines. Given its coverage and scope, it offers a helpful guide for graduate students and researchers in the areas of control theory and applied mathematics.
The redoubtable ecological periodic table
Ecological periodic tables are repositories of reliable information on quantitative, predictably recurring (periodic) habitat–community patterns and their uncertainty, scaling and transferability. Their reliability derives from their grounding in sound ecological principle...
SPECTROSCOPIC ORBITAL PERIODS FOR 29 CATACLYSMIC VARIABLES FROM THE SLOAN DIGITAL SKY SURVEY
Energy Technology Data Exchange (ETDEWEB)
Thorstensen, John R.; Taylor, Cynthia J.; Peters, Christopher S.; Skinner, Julie N. [Department of Physics and Astronomy 6127 Wilder Laboratory, Dartmouth College Hanover, NH 03755-3528 (United States); Southworth, John [Astrophysics Group Keele University Staffordshire ST5 5BG (United Kingdom); Gänsicke, Boris T. [Department of Physics University of Warwick Coventry CV4 7AL (United Kingdom)
2015-04-15
We report follow-up spectroscopy of 29 cataclysmic variables from the Sloan Digital Sky Survey (SDSS), 22 of which were discovered by SDSS and seven of which are previously known systems that were recovered in SDSS. The periods for 16 of these objects were included in the tabulation by Gänsicke et al. While most of the systems have periods less than 2 hr, only one has a period in the 80–86 minutes “spike” found by Gänsicke et al., and 11 have periods longer than 3 hr, indicating that the present sample is skewed toward longer-period, higher-luminosity objects. Seven of the objects have spectra resembling dwarf novae, but have apparently never been observed in outburst, suggesting that many cataclysmics with relatively low variability amplitude remain to be discovered. Some of the objects are notable. SDSS J07568+0858 and SDSS J08129+1911 were previously known to have deep eclipses; in addition to spectroscopy, we use archival data from the Catalina Real Time Transient Survey to refine their periods. We give a parallax-based distance of 195 (+54, −39) pc for LV Cnc (SDSS J09197+0857), which at P{sub orb} = 81 m has the shortest orbital period in our sample. SDSS J08091+3814 shows both the spectroscopic phase offset and phase-dependent absorption found in SW Sextantis stars. The average spectra of SDSS J08055+0720 and SDSS J16191+1351 show contributions from K-type secondaries, and SDSS J080440+0239 shows a contribution from an early M star. We use these to constrain the distances. SDSS J09459+2922 has characteristics typical of a magnetic system. SDSS11324+6249 may be a novalike variable, and if so, its orbital period (99 minutes) is unusually short for that subclass.
Periodic waves in nonlinear metamaterials
International Nuclear Information System (INIS)
Liu, Wen-Jun; Xiao, Jing-Hua; Yan, Jie-Yun; Tian, Bo
2012-01-01
Periodic waves are presented in this Letter. With symbolic computation, equations for monochromatic waves are studied, and analytic periodic waves are obtained. Factors affecting properties of periodic waves are analyzed. Nonlinear metamaterials, with the continuous distribution of the dielectric permittivity obtained, are different from the ones with the discrete distribution. -- Highlights: ► Equations for the monochromatic waves in transverse magnetic polarization have been studied. ► Analytic periodic waves for the equations have been obtained. ► Periodic waves are theoretically presented and studied in the nonlinear metamaterials.
Nonparametric Inference for Periodic Sequences
Sun, Ying
2012-02-01
This article proposes a nonparametric method for estimating the period and values of a periodic sequence when the data are evenly spaced in time. The period is estimated by a "leave-out-one-cycle" version of cross-validation (CV) and complements the periodogram, a widely used tool for period estimation. The CV method is computationally simple and implicitly penalizes multiples of the smallest period, leading to a "virtually" consistent estimator of integer periods. This estimator is investigated both theoretically and by simulation.We also propose a nonparametric test of the null hypothesis that the data have constantmean against the alternative that the sequence of means is periodic. Finally, our methodology is demonstrated on three well-known time series: the sunspots and lynx trapping data, and the El Niño series of sea surface temperatures. © 2012 American Statistical Association and the American Society for Quality.
Positive periodic solutions of delayed periodic Lotka-Volterra systems
International Nuclear Information System (INIS)
Lin Wei; Chen Tianping
2005-01-01
In this Letter, for a general class of delayed periodic Lotka-Volterra systems, we prove some new results on the existence of positive periodic solutions by Schauder's fixed point theorem. The global asymptotical stability of positive periodic solutions is discussed further, and conditions for exponential convergence are given. The conditions we obtained are weaker than the previously known ones and can be easily reduced to several special cases
Photolysis of Periodate and Periodic Acid in Aqueous Solution
DEFF Research Database (Denmark)
Sehested, Knud; Kläning, U. K.
1978-01-01
The photochemistry of periodate and periodic acid in aqueous solution was studied (i) by quantum yield measurements at low light intensity (ii) by flash photolysis, and (iii) by photolysis of glassy samples at 77 K. The photochemical studies were supplemented with pulse radiolysis studies...... of aqueous periodate solutions and with kinetic studies using stopped-flow technique. In strongly alkaline solution the photodecomposition of periodate proceeds via formation of O– and IVI. At pH solution O3 P is formed in a small...
Development of Advanced Concept for Shortening Construction Period of ABWR Plant
International Nuclear Information System (INIS)
Hiroshi Ijichi; Toshio Yamashita; Masahiro Tsutagawa; Hiroya Mori; Nobuaki Ooshima; Jun Miura; Minoru Kanechika; Nobuaki Miura
2002-01-01
Construction of a nuclear power plant (NPP) requires a very long period because of large amount of construction materials and many issues for negotiation among multiple sections. Shortening the construction period advances the date of return on an investment, and can also result in reduced construction cost. Therefore, the study of this subject has a very high priority for utilities. We achieved a construction period of 37 months from the first concrete work to fuel loading (F/L) (51.5 months from the inspection of the foundation (I/F) to the start of commercial operation (C/O)) at the Kashiwazaki-Kariwa NPPs No. 6 and 7 (KK-6/7), which are the first ABWR plants in the world. At TEPCO's next plant, we think that a construction period of less than 36 months (45 months from I/F to C/O) can be realized based on conventional methods such as early start of equipment installation and blocking of equipment to be brought in advance. Furthermore, we are studying the feasibility of a 21.5-month construction period (30 months from I/F to C/O) with advanced ideas and methods. The important concepts for a 21.5-month construction period are adoption of a new building structure that is the steel plate reinforced concrete (SC) structure and promotion of extensive modularization of equipment and building structure. With introducing these new concepts, we are planning the master schedule (M/S) and finding solutions to conflicts in the schedule of area release from building construction work to equipment installation work (schedule-conflicts.) In this report, we present the shortest construction period and an effective method to put it into practice for the conventional general arrangement (GA) of ABWR. In the future, we will continue the study on the improvement of building configuration and arrangements, and make clear of the concept for large composite modules of building structures and equipment. (authors)
Engineering electronic states of periodic and quasiperiodic chains by buckling
Mukherjee, Amrita; Nandy, Atanu; Chakrabarti, Arunava
2017-07-01
The spectrum of spinless, non-interacting electrons on a linear chain that is buckled in a non-uniform, quasiperiodic manner is investigated within a tight binding formalism. We have addressed two specific cases, viz., a perfectly periodic chain wrinkled in a quasiperiodic Fibonacci pattern, and a quasiperiodic Fibonacci chain, where the buckling also takes place in a Fibonacci pattern. The buckling brings distant neighbors in the parent chain to close proximity, which is simulated by a tunnel hopping amplitude. It is seen that, in the perfectly ordered case, increasing the strength of the tunnel hopping (that is, bending the segments more) absolutely continuous density of states is retained towards the edges of the band, while the central portion becomes fragmented and host subbands of narrowing widths containing extended, current carrying states, and multiple isolated bound states formed as a result of the bending. A switching ;on; and ;off; of the electronic transmission can thus be engineered by buckling. On the other hand, in the second example of a quasiperiodic Fibonacci chain, imparting a quasiperiodic buckling is found to generate continuous subband(s) destroying the usual multifractality of the energy spectrum. We present exact results based on a real space renormalization group analysis, that is corroborated by explicit calculation of the two terminal electronic transport.
From Periodic Properties to a Periodic Table Arrangement
Besalú, Emili
2013-01-01
A periodic table is constructed from the consideration of periodic properties and the application of the principal components analysis technique. This procedure is useful for objects classification and data reduction and has been used in the field of chemistry for many applications, such as lanthanides, molecules, or conformers classification.…
Periodic instantons and scattering amplitudes
International Nuclear Information System (INIS)
Khlebnikov, S.Yu.; Rubakov, V.A.; Tinyakov, P.G.
1991-04-01
We discuss the role of periodic euclidean solutions with two turning points and zero winding number (periodic instantons) in instanton induced processes below the sphaleron energy E sph . We find that the periodic instantons describe certain multiparticle scattering events leading to the transitions between topologically distinct vacua. Both the semiclassical amplitudes and inital and final states of these transitions are determined by the periodic instantons. Furthermore, the corresponding probabilities are maximal among all states of given energy. We show that at E ≤ E sph , the periodic instantons can be approximated by infinite chains of ordinary instantons and anti-instantons, and they naturally emerge as deformations of the zero energy instanton. In the framework of 2d abelian Higgs model and 4d electroweak theory we show, however, that there is not obvious relation between periodic instantons and two-particle scattering amplitudes. (orig.)
Holonomic systems for period mappings
Energy Technology Data Exchange (ETDEWEB)
Chen, Jingyue, E-mail: jychen@brandeis.edu [Department of Mathematics, Brandeis University, Waltham, MA 02454 (United States); Huang, An, E-mail: anhuang@math.harvard.edu [Department of Mathematics, Harvard University, Cambridge, MA 02138 (United States); Lian, Bong H., E-mail: lian@brandeis.edu [Department of Mathematics, Brandeis University, Waltham, MA 02454 (United States)
2015-09-15
Period mappings were introduced in the sixties [4] to study variation of complex structures of families of algebraic varieties. The theory of tautological systems was introduced recently [7,8] to understand period integrals of algebraic manifolds. In this paper, we give an explicit construction of a tautological system for each component of a period mapping. We also show that the D-module associated with the tautological system gives rise to many interesting vanishing conditions for period integrals at certain special points of the parameter space.
Microprocessor controlled digital period meter
International Nuclear Information System (INIS)
Keefe, D.J.; McDowell, W.P.; Rusch, G.K.
1980-01-01
A microprocessor controlled digital period meter has been developed and tested operationally on a reactor at Argonne National Laboratory. The principle of operation is the mathematical relationship between asymptotic periods and pulse counting circuitry. This relationship is used to calculate and display the reactor periods over a range of /plus or minus/1 second to /plus or minus/999 seconds. The time interval required to update each measurement automatically varies from 8 seconds at the lowest counting rates to 2 seconds at higher counting rates. The paper will describe hardware and software design details and show the advantages of this type of Period Meter over the conventional circuits. 1 ref
Forward Period Analysis Method of the Periodic Hamiltonian System.
Directory of Open Access Journals (Sweden)
Pengfei Wang
Full Text Available Using the forward period analysis (FPA, we obtain the period of a Morse oscillator and mathematical pendulum system, with the accuracy of 100 significant digits. From these results, the long-term [0, 1060] (time unit solutions, ranging from the Planck time to the age of the universe, are computed reliably and quickly with a parallel multiple-precision Taylor series (PMT scheme. The application of FPA to periodic systems can greatly reduce the computation time of long-term reliable simulations. This scheme provides an efficient way to generate reference solutions, against which long-term simulations using other schemes can be tested.
Detecting periodicities with Gaussian processes
Directory of Open Access Journals (Sweden)
Nicolas Durrande
2016-04-01
Full Text Available We consider the problem of detecting and quantifying the periodic component of a function given noise-corrupted observations of a limited number of input/output tuples. Our approach is based on Gaussian process regression, which provides a flexible non-parametric framework for modelling periodic data. We introduce a novel decomposition of the covariance function as the sum of periodic and aperiodic kernels. This decomposition allows for the creation of sub-models which capture the periodic nature of the signal and its complement. To quantify the periodicity of the signal, we derive a periodicity ratio which reflects the uncertainty in the fitted sub-models. Although the method can be applied to many kernels, we give a special emphasis to the Matérn family, from the expression of the reproducing kernel Hilbert space inner product to the implementation of the associated periodic kernels in a Gaussian process toolkit. The proposed method is illustrated by considering the detection of periodically expressed genes in the arabidopsis genome.
Scheduling periodic tasks with slack
Korst, J.H.M.; Aarts, E.H.L.; Lenstra, J.K.
1997-01-01
We consider the problem of nonpreemptively scheduling periodic tasks on a minimum number of identical processors, assuming that some slack is allowed in the time between successive executions of a periodic task. We prove that the problem is NP-hard in the strong sense. Necessary and sufficient
Rationalization of Comet Halley's periods
Belton, Michael J. S.
1990-01-01
The sense of long axis orientation of Comet Halley during the Vega 1 encounter must be reversed from that deduced by Sagdeev et al. (1986) in order to harmonize the comet nucleus' Vega/Giotto-observed orientations with periodicities extracted from time-series brightness data. It is also demonstrated that Vega/Giotto observations can be satisfied by either a 2.2- or 3.7-day long-axis free precession period. A novel Fourier algorithm is used to reanalyze five independent data sets; strong evidence is adduced for periods harmonically related to a 7.4-day period. The preferred candidate models for Halley's nuclear rotation are characterized by a long-axis precession period of 3.7 days.
Orbital periods of recurrent novae
International Nuclear Information System (INIS)
Schaefer, B.E.
1990-01-01
The class of recurrent novae (RN) with thermonuclear runaways contains only three systems (T Pyx, U Sco, and V394 CrA), for which no orbital periods are known. This paper presents a series of photometric observations where the orbital periods for all three systems are discovered. T Pyx is found to have sinusoidal modulation with an amplitude of 0.08 mag and a period of 2.3783 h (with a possible alias of 2.6403 h). U Sco is found to be an eclipsing system with an eclipse amplitude of roughly 1.5 mag and an orbital period of 1.2344 days. V394 CrA is found to have sinusoidal modulation with an amplitude of 0.5 mag and a period of 0.7577 days. Thus two out of three RN with thermonuclear runaways (or five out of six for all RN) have evolved companions. 16 refs
International Nuclear Information System (INIS)
Li Qianshu; Zhu Rui
2004-01-01
A three-variable model of the Belousov-Zhabotinsky reaction system subject to external sinusoidal perturbations is investigated by means of frequency spectrum analysis. In the period-1 window of the model, the transitions from periodicity to chaos are observed; in the chaotic window, the transitions from chaos to periodicity are found. The former might be understood by the circle map of two coupled oscillators, and the latter is partly explained by the resonance between the main frequency of the chaos and the frequency of the external periodic perturbations
Iraqi architecture in mogul period
Directory of Open Access Journals (Sweden)
Hasan Shatha
2018-01-01
Full Text Available Iraqi architecture have many periods passed through it until now, each on from these periods have it is architectural style, also through time these styles interacted among us, to creating kind of space forming, space relationships, and architectural elements (detailed treatments, the research problem being from the multi interacted architectural styles causing some of confused of general characteristic to every style, that we could distinguish by it. Research tries to study architecture style through Mogul Conquest to Baghdad. Aim of research follow main characteristic for this architectural style in the Mogul periods on the level of form, elements, and treatments. Research depending on descriptive and analytical all buildings belong to this period, so from analyzing there style by, general form for building, architectural elements, and it architectural treatment, therefore; repeating this procedures to every building we get some similarities, from these similarities we can making conclusion about pure characteristic of the style of these period. Other side, we also discover some Dissimilar in the building periods, these will lead research to make what interacting among styles in this period, after all that we can drew clearly main characteristic of Architectural Style for Mogul Conquest in Baghdad
Directory of Open Access Journals (Sweden)
Raos, N.
2011-12-01
Full Text Available The Croatian (Yugoslav Academy of Sciences and Arts was the first academy to elect D. I. Mendeleev as its honorary member (1882, whereas the periodic table of the elements has been taught regularly at the Zagreb University since 1888. The early interest of Croatian chemists in the periodic table should be attributed primarily to their pan-Slavic attitude, particularly as proof that Slavic people were able to produce "their own Newtons" (M. V. Lomonosov and D. I. Mendeleev. Such enthusiastic views, however, did not help in analyzing the contribution of Mendeleev and other scientists to the discovery and development of the periodic table of the elements.
Topological imprint for periodic orbits
International Nuclear Information System (INIS)
Martín, Jesús San; Moscoso, Ma José; Gómez, A González
2012-01-01
The more self-crossing points an orbit has the more complex it is. We introduce the topological imprint to characterize crossing points and focus on the period-doubling cascade. The period-doubling cascade topological imprint determines the topological imprint for orbits in chaotic bands. In addition, there is a closer link between this concept and the braids studied by Lettelier et al (2000 J. Phys. A: Math. Gen. 33 1809–25). (paper)
Minimum period and the gap in periods of Cataclysmic binaries
International Nuclear Information System (INIS)
Paczynski, B.; Sienkiewicz, R.
1983-01-01
The 81 minute cutoff to the orbital periods of hydrogen-rich cataclysmic binaries is consistent with evolution of those systems being dominated by angular momentum losses due to gravitational radiation. Unfortunately, many uncertainties, mainly poorly known atmospheric opacities below 2000 K, make is physically impossible to verify the quadrupole formula for gravitational radiation by using the observed cutoff at 81 minutes. The upper boundary of the gap in orbital periods observed at about 3 hours is almost certainly due to enhanced angular momentum losses from cataclysmic binaries which have longer periods. The physical mechanism of those losses is not identified, but a possible importance of stellar winds is pointed out. The lower boundary of the gap may be explained with the oldest cataclysmic binaries, whose periods evolved past the minimum at 81 minutes and reached the value of 2 hours within about 12 x 10 9 years after the binary had formed. Those binaries should have secondary components of only 0.02 solar masses, and their periods could be used to estimate ages of the oldest cataclysmic stars, and presumably the age of Galaxy. An alternative explanation for the gap requires that binaries should be detached while crossing the gap. A possible mechanism for this phenomenon is discussed. It requires the secondary components to be about 0.2 solar masses in the binaries just below the gap
Commuting periodic operators and the periodic Wigner function
International Nuclear Information System (INIS)
Zak, J
2004-01-01
Commuting periodic operators (CPO) depending on the coordinate x-hat and the momentum p-hat operators are defined. The CPO are functions of the two basic commuting operators exp(i x-hat 2π/a) and exp(i/h p-hat a), with a being an arbitrary constant. A periodic Wigner function (PWF) w(x, p) is defined and it is shown that it is applicable in a normal expectation value calculation to the CPO, as done in the original Wigner paper. Moreover, this PWF is non-negative everywhere, and it can therefore be interpreted as an actual probability distribution. The PWF w(x, p) is shown to be given as an expectation value of the periodic Dirac delta function in the phase plane. (letter to the editor)
Nanopublication beyond the sciences: the PeriodO period gazetteer
Directory of Open Access Journals (Sweden)
Patrick Golden
2016-02-01
Full Text Available The information expressed in humanities datasets is inextricably tied to a wider discursive environment that is irreducible to complete formal representation. Humanities scholars must wrestle with this fact when they attempt to publish or consume structured data. The practice of “nanopublication,” which originated in the e-science domain, offers a way to maintain the connection between formal representations of humanities data and its discursive basis. In this paper we describe nanopublication, its potential applicability to the humanities, and our experience curating humanities nanopublications in the PeriodO period gazetteer.
Periodic testing in operative action
International Nuclear Information System (INIS)
Larm, T.
2005-01-01
Periodic testing forms a remarkable part of the regular work tasks of the shift crew. Testing is generally carried out beside the daily monitoring and control work. Even remarkable plant related differences may occur in the procedures and routines used in periodic testing. The goal is still always the same, to regularly ensure that the systems and equipment are in working order according to their design. This presentation studies with examples the execution and scope of periodic testing as well as the routines and procedures used in the testing in Loviisa power plant. The presentation is based on the testing procedures of Loviisa power plant and the aim is not to compare them to the procedures of other plants. The scope of periodic testing has increased and the routines and procedures have been developed as the operation experience has increased. The assessment of the need of periodic testing and the consideration of the practical execution possibilities should be a part of the plant's planning phase as a part of the planning process. (orig.)
Inflation from periodic extra dimensions
Energy Technology Data Exchange (ETDEWEB)
Higaki, Tetsutaro [Department of Physics, Keio University, Kanagawa 223-8522 (Japan); Tatsuta, Yoshiyuki, E-mail: thigaki@rk.phys.keio.ac.jp, E-mail: y_tatsuta@akane.waseda.jp [Department of Physics, Waseda University, Tokyo 169-8555 (Japan)
2017-07-01
We discuss a realization of a small field inflation based on string inspired supergravities. In theories accompanying extra dimensions, compactification of them with small radii is required for realistic situations. Since the extra dimension can have a periodicity, there will appear (quasi-)periodic functions under transformations of moduli of the extra dimensions in low energy scales. Such a periodic property can lead to a UV completion of so-called multi-natural inflation model where inflaton potential consists of a sum of multiple sinusoidal functions with a decay constant smaller than the Planck scale. As an illustration, we construct a SUSY breaking model, and then show that such an inflaton potential can be generated by a sum of world sheet instantons in intersecting brane models on extra dimensions containing orbifold. We show also predictions of cosmic observables by numerical analyzes.
Periodicity, the Canon and Sport
Directory of Open Access Journals (Sweden)
Thomas F. Scanlon
2015-10-01
Full Text Available The topic according to this title is admittedly a broad one, embracing two very general concepts of time and of the cultural valuation of artistic products. Both phenomena are, in the present view, largely constructed by their contemporary cultures, and given authority to a great extent from the prestige of the past. The antiquity of tradition brings with it a certain cachet. Even though there may be peripheral debates in any given society which question the specifics of periodization or canonicity, individuals generally accept the consensus designation of a sequence of historical periods and they accept a list of highly valued artistic works as canonical or authoritative. We will first examine some of the processes of periodization and of canon-formation, after which we will discuss some specific examples of how these processes have worked in the sport of two ancient cultures, namely Greece and Mesoamerica.
Periodicity and repeatability in data
Southwood, D.
Using magnetic data from the first two years in Saturn orbit, the basic periodicity of apparent is examined with the aim of elucidating the `cam' shaft model of Espinosa et al. (2003) identifying the nature of the `cam' and giving a definitive period for its rotation. An initial hypothesis, supported by the spectral analysis of analysis of the first 8 months in orbit Gianpieri et al. (2006), is made that the source of the period is linked to something inside the planet and therefore that the source inertia means that the period effectively does not change over the 2 years. Moreover one expects that the source phase is fixed. Using this approach, not only can the period identified by spectral analysis (647.1 + 0.6 min.) be verified but also by phase analysis between successive passes over the 2 years the period can be refined to 647.6 + 0.1 min. The signal itself is remarkably reproducible from pass to pass. It appears in all three components of the field and its polarisation is unambiguously not attributable to direct detection of an internal field. Not only does the signal not decay rapidly with distance from the planet, but although it has the m=1 symmetry of a tilted dipole, the field lines diverge from the planet indicating an exterior source. This feature led to the `cam' model. The polarisation and comparisons of passes with different latitude profiles show a surprising north-south symmetry in the azimuthal field. The absence of asymmetry with respect to the magnetic equator rules out a direct magnetospheric-ionospheric interaction source. Accordingly, it is proposed that the basic `cam' effect is generated by a single hemisphere anomaly which creates hemisphere to hemisphere field aligned currents. The existence of Saturn phase related anomaly appears to produce a basic asymmetry in the inner magnetosphere that sets the phase of both an inflowing and outflowing sector in a rotating circulation system.
An improved test for periodicity
International Nuclear Information System (INIS)
Davies, S.R.
1990-01-01
I discuss two widely used methods of testing for periodicity, phase dispersion minimization and epoch-folding. Using an analysis of variance approach, I demonstrate the close relationship between these two methods. I also show that the significance test sometimes used in phase dispersion minimization is statistically inaccurate, and that the test used in epoch-folding is an approximation valid only for large sample sizes. I propose a new test statistic, applicable to either epoch-folding or PDM, which is statistically sound for all sample sizes, and which is also more sensitive to periodicity than the test statistics previously used with these two methods. (author)
Sigmoid Volvulus Complicating Postpartum Period
Directory of Open Access Journals (Sweden)
Kelsey E. Ward
2017-01-01
Full Text Available Background. Sigmoid volvulus is a rare complication of pregnancy and the puerperium. Case. A 19-year-old patient, gravida 1 para 0 at 41 0/7 weeks of gestation, admitted for late-term induction of labor underwent an uncomplicated primary low transverse cesarean delivery for arrest of descent. Her postoperative period was complicated by sudden onset of abdominal pain and the ultimate diagnosis of sigmoid volvulus. Conclusion. Prompt surgical evaluation of an acute abdomen in the postpartum period is essential; delayed diagnosis and treatment can lead to significant maternal morbidity and mortality.
Hydrogen purification by periodic adsorption
Energy Technology Data Exchange (ETDEWEB)
Barg, Christian; Secchi, Argimiro R.; Trierweiler, Jorge O. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Dept. de Engenharia Quimica]. E-mail: cbarg@enq.ufrgs.br; arge@enq.ufrgs.br; jorge@enq.ufrgs.br
2000-07-01
The periodic adsorption processes have been widely used for industrial applications, mainly because it spends less energy than the usual gas separation processes, like the cryogenic distillation. The largest commercial application of periodic adsorption processes is the pressure swing adsorption (PSA) applied to hydrogen purification. Although its wide use in the chemical and petrochemical industry, there are no reports in the open literature about complete modeling studies of a complex commercial unit, with multiple adsorbents and multiple beds and several feed components. This study has as objective the modeling, optimization and dynamical analysis of an industrial PSA unit for hydrogen purification. (author)
Availability of periodically tested systems
International Nuclear Information System (INIS)
Signoret, J.P.
1979-01-01
There is at the present time a need in accurate models to asess the availability of periodically tested stand-by systems. This paper shows how to improve the well known 'saw-tooth curve' model in order to take into account various reliability parameters. A model is developed to assess the pointwise and the mean availabilities of periodically tested stand-by systems. Exact and approxination formulae are given. In addition, the model developed herein leads to optimize the test interval in order to minimize the mean unavailability. A safety diesel in a nuclear power plant is given as an example
THE VERY SHORT PERIOD M DWARF BINARY SDSS J001641-000925
Energy Technology Data Exchange (ETDEWEB)
Davenport, James R. A.; Becker, Andrew C.; Hawley, Suzanne L.; Gunning, Heather C.; Munshi, Ferah A.; Albright, Meagan [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); West, Andrew A. [Astronomy Department, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Bochanski, John J. [Astronomy and Astrophysics Department, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Holtzman, Jon [Department of Astronomy, New Mexico State University, Box 30001, Las Cruces, NM 88003 (United States); Hilton, Eric J., E-mail: jrad@astro.washington.edu [Department of Geology and Geophysics and Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)
2013-02-10
We present follow-up observations and analysis of the recently discovered short period low-mass eclipsing binary, SDSS J001641-000925. With an orbital period of 0.19856 days, this system has one of the shortest known periods for an M dwarf binary system. Medium-resolution spectroscopy and multi-band photometry for the system are presented. Markov Chain Monte Carlo modeling of the light curves and radial velocities yields estimated masses for the stars of M {sub 1} = 0.54 {+-} 0.07 M {sub Sun} and M {sub 2} = 0.34 {+-} 0.04 M {sub Sun }, and radii of R {sub 1} = 0.68 {+-} 0.03 R {sub Sun} and R {sub 2} = 0.58 {+-} 0.03 R {sub Sun }, respectively. This solution places both components above the critical Roche overfill limit, providing strong evidence that SDSS J001641-000925 is the first verified M-dwarf contact binary system. Within the follow-up spectroscopy we find signatures of non-solid body rotation velocities, which we interpret as evidence for mass transfer or loss within the system. In addition, our photometry samples the system over nine years, and we find strong evidence for period decay at the rate of P-dot {approx} 8 s yr{sup -1}. Both of these signatures raise the intriguing possibility that the system is in over-contact, and actively losing angular momentum, likely through mass loss. This places SDSS J001641-000925 as not just the first M-dwarf over-contact binary, but one of the few systems of any spectral type known to be actively undergoing coalescence. Further study of SDSS J001641-000925 is ongoing to verify the nature of the system, which may prove to be a unique astrophysical laboratory.
Periodic and quasiperiodic revivals in periodically driven interacting quantum systems
Luitz, David J.; Lazarides, Achilleas; Bar Lev, Yevgeny
2018-01-01
Recently it has been shown that interparticle interactions generically destroy dynamical localization in periodically driven systems, resulting in diffusive transport and heating. In this Rapid Communication we rigorously construct a family of interacting driven systems which are dynamically localized and effectively decoupled from the external driving potential. We show that these systems exhibit tunable periodic or quasiperiodic revivals of the many-body wave function and thus of all physical observables. By numerically examining spinless fermions on a one-dimensional lattice we show that the analytically obtained revivals of such systems remain stable for finite systems with open boundary conditions while having a finite lifetime in the presence of static spatial disorder. We find this lifetime to be inversely proportional to the disorder strength.
Cosmophysical periods in European history
International Nuclear Information System (INIS)
Vladimirskij, B.M.; Kislovskij, L.D.
1995-01-01
In social systems there are rhythms synchronised by cosmical periods. These rhythms have partly biological origin. Some natural cycles also might influence upon historical processes (as such as climatic and epidemical). The analysis of the literature shows that there is rhythmic component in European history where solar activity cycles -11 and 340 years are presented. 17 refs., 2 tabs
International Nuclear Information System (INIS)
1969-01-01
'Isn't it the work of a genius!' exclaimed Academician V.I. Spitsyn, USSR, a member of the Scientific Advisory Committee when talking to an Agency audience in January. His listeners shared his enthusiasm. Academician Spitsyn was referring to the first formulation a hundred years ago by Professor Dmitry I. Mendeleyev of the Periodic Law of Elements. (author)
Glass Waveguides for Periodic Poling
DEFF Research Database (Denmark)
Fage-Pedersen, Jacob; Jacobsen, Rune Shim; Kristensen, Martin
2005-01-01
Planar silica-based waveguide devices have been developed for second-harmonic generation by poling with periodic electrodes. We show that detrimental charge transport can occur along interfaces, but with proper choice of fabrication, high-quality devices are obtained....
Periodic linear differential stochastic processes
Kwakernaak, H.
1975-01-01
Periodic linear differential processes are defined and their properties are analyzed. Equivalent representations are discussed, and the solutions of related optimal estimation problems are given. An extension is presented of Kailath and Geesey’s [1] results concerning the innovations representation
Model selection in periodic autoregressions
Ph.H.B.F. Franses (Philip Hans); R. Paap (Richard)
1994-01-01
textabstractThis paper focuses on the issue of period autoagressive time series models (PAR) selection in practice. One aspect of model selection is the choice for the appropriate PAR order. This can be of interest for the valuation of economic models. Further, the appropriate PAR order is important
Periodic progress report, 6 months
DEFF Research Database (Denmark)
Juhl, Thomas Winther; Nielsen, Jakob Skov
This is the first progress report of the BriteEuram project named "High Power Laser Cutting for Heavy Industry" ("Powercut"). The report contains a summary of the objectives of the first period, an overview of the technical progress, a comparison between the planed and the accomplished work...
Autoinflammatory Diseases with Periodic Fevers.
Sag, Erdal; Bilginer, Yelda; Ozen, Seza
2017-07-01
One purpose of this review was to raise awareness for the new autoinflammatory syndromes. These diseases are increasingly recognized and are in the differential diagnosis of many disease states. We also aimed to review the latest recommendations for the diagnosis, management, and treatment of these patients. Familial Mediterranean fever (FMF), cryopyrin-associated periodic syndrome (CAPS), tumor necrosis factor receptor-associated periodic fever syndrome (TRAPS), and hyperimmunoglobulinemia D and periodic fever syndrome/mevalonate kinase deficiency (HIDS/MVKD) are the more common autoinflammatory diseases that are characterized by periodic fevers and attacks of inflammation. Recently much collaborative work has been done to understand the characteristics of these patients and to develop recommendations to guide the physicians in the care of these patients. These recent recommendations will be summarized for all four diseases. FMF is the most common periodic fever disease. We need to further understand the pathogenesis and the role of single mutations in the disease. Recently, the management and treatment of the disease have been nicely reviewed. CAPS is another interesting disease associated with severe complications. Anti-interleukin-1 (anti-IL-1) treatment provides cure for these patients. TRAPS is characterized by the longest delay in diagnosis; thus, both pediatricians and internists should be aware of the characteristic features and the follow-up of these patients. HIDS/MVKD is another autoinflammatory diseases characterized with fever attacks. The spectrum of disease manifestation is rather large in this disease, and we need further research on biomarkers for the optimal management of these patients.
Vertebrate fauna of the Roman period, migrations period and Medieval period in Vojvodina (Serbia
Directory of Open Access Journals (Sweden)
Radmanović Darko P.
2014-01-01
Full Text Available Based on current published and unpublished research results, a total of 16 vertebrate species members of mammal (Mammalia, bird (Aves and osteichthyes (Osteichthyes classes have been registered at 11 archaeological sites from the Roman Period in Vojvodina. Mammals dominate with 12 species and one genus, birds are present with 3 species, and osteichthyes with one. From the Migration Period, at 9 sites, 22 vertebrate species have been registered, of which 13 species and one genus of mammals, 4 species and one genus of birds, and 5 species from the Osteichthyes class. At 8 sites from the Medieval Period, 16 vertebrate species have been registered. Mammals are the most numerous class with 10 species and one genus, while birds are present with 4 species and one genus. Furthermore, two species of osteichthyes have also been registered.
Evolutionary dynamics of incubation periods.
Ottino-Loffler, Bertrand; Scott, Jacob G; Strogatz, Steven H
2017-12-21
The incubation period for typhoid, polio, measles, leukemia and many other diseases follows a right-skewed, approximately lognormal distribution. Although this pattern was discovered more than sixty years ago, it remains an open question to explain its ubiquity. Here, we propose an explanation based on evolutionary dynamics on graphs. For simple models of a mutant or pathogen invading a network-structured population of healthy cells, we show that skewed distributions of incubation periods emerge for a wide range of assumptions about invader fitness, competition dynamics, and network structure. The skewness stems from stochastic mechanisms associated with two classic problems in probability theory: the coupon collector and the random walk. Unlike previous explanations that rely crucially on heterogeneity, our results hold even for homogeneous populations. Thus, we predict that two equally healthy individuals subjected to equal doses of equally pathogenic agents may, by chance alone, show remarkably different time courses of disease.
Period of an Interrupted Pendulum
Miller, Bradley E.
2002-11-01
While demonstrating a classic conservation-of-energy problem to my AP Physics students, I became curious about the periodic motion that ensued for certain initial conditions. The original problem consists of releasing a mass at the end of a string from an initial position horizontal to the plane of a table. The string comes in contact with a peg some distance below the point where the string is attached at the top. One is asked to find what minimum fraction of the string's length should the peg be placed to have the mass complete a circle about the peg. However, when the mass is released from much lower heights, the system undergoes periodic motion that can be thought of as an interrupted pendulum.
Periodicity of the stable isotopes
Boeyens, J C A
2003-01-01
It is demonstrated that all stable (non-radioactive) isotopes are formally interrelated as the products of systematically adding alpha particles to four elementary units. The region of stability against radioactive decay is shown to obey a general trend based on number theory and contains the periodic law of the elements as a special case. This general law restricts the number of what may be considered as natural elements to 100 and is based on a proton:neutron ratio that matches the golden ratio, characteristic of biological and crystal growth structures. Different forms of the periodic table inferred at other proton:neutron ratios indicate that the electronic configuration of atoms is variable and may be a function of environmental pressure. Cosmic consequences of this postulate are examined. (author)
On nonlinear periodic drift waves
International Nuclear Information System (INIS)
Kauschke, U.; Schlueter, H.
1990-09-01
Nonlinear periodic drift waves are investigated on the basis of a simple perturbation scheme for both the amplitude and inverse frequency. The coefficients for the generation of the forced harmonics are derived, a nonlinear dispersion relation is suggested and a criterion for the onset of the modulational instability is obtained. The results are compared with the ones obtained with the help of a standard KBM-treatment. Moreover cnoidal drift waves are suggested and compared to an experimental observation. (orig.)
Long Period Seismological Research Program
1974-10-31
in central Asia as observed at the high-gain long- period sites. Preliminary results from observations at Chiang Mai (CHG) show that the complexity...Preliminary results from observations at Chiang Mai (CHG) show that the complexity of the surface wave signals from many events in the Tadzhik-Kirgiz...and receivers. A number of Interesting features can be illustrated by examining portions of three selsmograms recorded at Chiang Mai (CHO
PHYSICAL PROPERTIES OF THE 0.94-DAY PERIOD TRANSITING PLANETARY SYSTEM WASP-18
International Nuclear Information System (INIS)
Southworth, John; Anderson, D. R.; Maxted, P. F. L.; Hinse, T. C.; Dominik, M.; Mathiasen, M.; Browne, P.; Glitrup, M.; Joergensen, U. G.; Harpsoee, K.; Liebig, C.; Maier, G.; Bozza, V.; Calchi Novati, S.; Mancini, L.; Burgdorf, M.; Dreizler, S.; Hessman, F.; Hundertmark, M.; Finet, F.
2009-01-01
We present high-precision photometry of five consecutive transits of WASP-18, an extrasolar planetary system with one of the shortest orbital periods known. Through the use of telescope defocusing we achieve a photometric precision of 0.47-0.83 mmag per observation over complete transit events. The data are analyzed using the JKTEBOP code and three different sets of stellar evolutionary models. We find the mass and radius of the planet to be M b = 10.43 ± 0.30 ± 0.24 M Jup and R b = 1.165 ± 0.055 ± 0.014 R Jup (statistical and systematic errors), respectively. The systematic errors in the orbital separation and the stellar and planetary masses, arising from the use of theoretical predictions, are of a similar size to the statistical errors and set a limit on our understanding of the WASP-18 system. We point out that seven of the nine known massive transiting planets (M b > 3 M Jup ) have eccentric orbits, whereas significant orbital eccentricity has been detected for only four of the 46 less-massive planets. This may indicate that there are two different populations of transiting planets, but could also be explained by observational biases. Further radial velocity observations of low-mass planets will make it possible to choose between these two scenarios.
International Nuclear Information System (INIS)
Smietana, M; Bock, W J; Mikulic, P; Chen, J
2011-01-01
This paper presents an investigation of the sensing properties of long-period gratings (LPGs) written with the electric-arc technique in commonly used standard germanium-doped Corning SMF28 and boron co-doped Fibercore PS1250/1500 fibers. In order to increase the sensitivity of the LPGs, we studied and established for each fiber the writing parameters allowing for the coupling of the highest possible order of cladding modes at a resonance wavelength around λ = 1550 nm. The sensitivity of the LPGs to refractive index, to temperature and to hydrostatic pressure was investigated. The experimental results were supported by extensive numerical simulations. Thanks to the well-established and precisely controlled arc-writing process, we were able to reduce the minimum period of the gratings down to 345 and 221 µm, respectively, for LPGs based on the SMF28 and PS1250/1500 fibers. To the best of our knowledge, these are the shortest periods ever achieved for these fibers using the arc-manufacturing technique. The pressure sensitivities of 13 and 220 pm bar −1 are the highest ever measured for LPGs written in the SMF28 and PS1250/1500 fibers, respectively. Moreover, a reduction in the diameters of the SMF28 fiber induced by the arc was found, which significantly affected the distribution of resonances generated by the coupled cladding modes
Energy Technology Data Exchange (ETDEWEB)
GAUTHIER,JOHN H.
2000-07-20
Terrestrial climate records and historical observations of the Sun suggest that the Sun undergoes aperiodic oscillations in radiative output and size over time periods of centuries and millenia. Such behavior can be explained by the solar convective zone acting as a nonlinear oscillator, forced at the sunspot-cycle frequency by variations in heliomagnetic field strength. A forced variant of the Lorenz equations can generate a time series with the same characteristics as the solar and climate records. The timescales and magnitudes of oscillations that could be caused by this mechanism are consistent with what is known about the Sun and terrestrial climate.
DEFF Research Database (Denmark)
Christensen, Ole; Goh, Say Song
2012-01-01
The time–frequency analysis of a signal is often performed via a series expansion arising from well-localized building blocks. Typically, the building blocks are based on frames having either Gabor or wavelet structure. In order to calculate the coefficients in the series expansion, a dual frame...... is needed. The purpose of the present paper is to provide constructions of dual pairs of frames in the setting of the Hilbert space of periodic functions L2(0,2π). The frames constructed are given explicitly as trigonometric polynomials, which allows for an efficient calculation of the coefficients...
Periodic dynamics in queuing networks
Energy Technology Data Exchange (ETDEWEB)
Addabbo, Tommaso [Information Engineering Department, University of Siena, Via Roma 56, 53100 Siena (Italy)], E-mail: addabbo@dii.unisi.it; Kocarev, Ljupco [Macedonian Academy of Sciences and Arts, bul. Krste Misirkov 2, P.O. Box 428, 1000 Skopje, Republic of Macedonia (Macedonia, The Former Yugoslav Republic of)], E-mail: lkocarev@ucsd.edu
2009-08-30
This paper deals with state-dependent open Markovian (or exponential) queuing networks, for which arrival and service rates, as well as routing probabilities, may depend on the queue lengths. For a network of this kind, following Mandelbaum and Pats, we provide a formal definition of its associated fluid model, and we focus on the relationships which may occur between the network stochastic dynamics and the deterministic dynamics of its corresponding fluid model, particularly focusing on queuing networks whose fluid models have global periodic attractors.
Periodic permanent magnet focused klystron
Ferguson, Patrick; Read, Michael; Ives, R Lawrence
2015-04-21
A periodic permanent magnet (PPM) klystron has beam transport structures and RF cavity structures, each of which has permanent magnets placed substantially equidistant from a beam tunnel formed about the central axis, and which are also outside the extent of a cooling chamber. The RF cavity sections also have permanent magnets which are placed substantially equidistant from the beam tunnel, but which include an RF cavity coupling to the beam tunnel for enhancement of RF carried by an electron beam in the beam tunnel.
Forgiveness in the intertestamental period
Directory of Open Access Journals (Sweden)
Sang-Mong Lee
2012-02-01
Full Text Available The article suggests answers to the following questions: what are the characteristics of God�s forgiveness in the intertestamental literature and what connection do these characteristics have with the Old Testament? Important passages in the late Second Temple period that expose the characteristics of God�s forgiveness, such as certain Qumran texts (1QH 12:35�37, 1QH 13:2 and the Damascus Document 14:18�19, the writings of Philo and Josephus, the Apocrypha and the Pseudepigrapha, are investigated for this purpose.
Periodic weather and climate variations
International Nuclear Information System (INIS)
Ivanov, Vladimir V
2002-01-01
Variations in meteorological parameters are largely due to periodic processes and can be forecast for several years. Many such processes are related to astronomical factors such as the gravitational influences of the Moon and the Sun, and the modulation of solar irradiance by lunar and planetary motion. The Moon, Jupiter, and Venus have the strongest effect. These influences produce lines in the spectra of meteorological variations, which are combinations of the harmonics of the frequencies of revolution of the planets, the Earth, and the Moon around the Sun with the harmonics of the lunar revolution around the Earth. Due to frequency differences between the orbital and radial motions, fine spectral features of three types appear: line splitting, line-profile complications due to radial oscillations, and additional lines due to the combination of radial-oscillation frequencies with perturbation harmonics. (reviews of topical problems)
The periodic table in Flatland
International Nuclear Information System (INIS)
Kibler, M.
1995-01-01
The D-dimensional Coulomb system serves as a starting point for generating generalized atomic shells. These shells are ordered according to a generalized Madelung rule in D dimensions. This rule together with an Aufbau Prinzip is applied to produce a D-dimensional periodic table. A model is developed to rationalize the ordering of the shells predicted by the generalized Madelung rule. This model is based on the introduction of an Hamiltonian, invariant under the q-deformed algebra U q (so(D)), that breaks down the SO (D + 1) dynamical symmetry of the hydrogen atom in D dimensions. The D = 2 case (Flatland) is investigated with some details. It is shown that the neutral atoms and the (moderately) positive ions correspond to the values q = 0.8 and q = 1, respectively, of the deformation parameter q. (authors). 55 refs
Periodic folding of viscous sheets
Ribe, Neil M.
2003-09-01
The periodic folding of a sheet of viscous fluid falling upon a rigid surface is a common fluid mechanical instability that occurs in contexts ranging from food processing to geophysics. Asymptotic thin-layer equations for the combined stretching-bending deformation of a two-dimensional sheet are solved numerically to determine the folding frequency as a function of the sheet’s initial thickness, the pouring speed, the height of fall, and the fluid properties. As the buoyancy increases, the system bifurcates from “forced” folding driven kinematically by fluid extrusion to “free” folding in which viscous resistance to bending is balanced by buoyancy. The systematics of the numerically predicted folding frequency are in good agreement with laboratory experiments.
Epstein, Richard J
2015-01-01
Cancers exhibit differences in metastatic behavior and drug sensitivity that correlate with certain tumor-specific variables such as differentiation grade, growth rate/extent and molecular regulatory aberrations. In practice, patient management is based on the past results of clinical trials adjusted for these biomarkers. Here, it is proposed that treatment strategies could be fine-tuned upfront simply by quantifying tumorigenic spatial (cell growth) and temporal (genetic stability) control losses, as predicted by genetic defects of cell-cycle-regulatory gatekeeper and genome-stabilizing caretaker tumor suppressor genes, respectively. These differential quantifications of tumor dysfunction may in turn be used to create a tumor-specific 'periodic table' that guides rational formulation of survival-enhancing anticancer treatment strategies.
Dynamic shortest path problems : hybrid routing policies considering network disruptions
Sever, D.; Dellaert, N.P.; Woensel, van T.; Kok, de A.G.
2013-01-01
Traffic network disruptions lead to significant increases in transportation costs. We consider networks in which a number of links are vulnerable to these disruptions leading to a significantly higher travel time on these links. For these vulnerable links, we consider known link disruption
Minimizing Communication in All-Pairs Shortest Paths
2013-02-13
on a 16,384 vertex, 5% dense graph, is slightly faster using our approach (18.6 vs . 22.6 seconds) than using the replicated Johnson’s algorithm...Oracle and Samsung , as well as MathWorks. Research is also supported by DOE grants DE-SC0004938, DE-SC0005136, DE-SC0003959, DE-SC0008700, and AC02...Brickell, I. S. Dhillon, S. Sra, and J. A. Tropp. The metric nearness problem. SIAM J. Matrix Anal. Appl ., 30:375–396, 2008. [11] A. Buluç, J. R. Gilbert
k-Shortest routing of trains on shunting yards
Riezebos, Jan; van Wezel, Wout
2009-01-01
We consider the problem of designing algorithmic support for k-best routing decisions in train shunting scheduling. A study at the Netherlands Railways revealed that planners like to interact with the solution process of finding suitable routes. Two types of interaction were required: the
A Random Riemannian Metric for Probabilistic Shortest-Path Tractography
DEFF Research Database (Denmark)
Hauberg, Søren; Schober, Michael; Liptrot, Matthew George
2015-01-01
of the diffusion tensor as a “random Riemannian metric”, where a geodesic is a distribution over tracts. We approximate this distribution with a Gaussian process and present a probabilistic numerics algorithm for computing the geodesic distribution. We demonstrate SPT improvements on data from the Human Connectome...
Analysis of the asymmetrical shortest two-server queueing model
J.W. Cohen
1995-01-01
textabstractThis study presents the analytic solution for the asymmetrical two-server queueing model with arriving customers joining the shorter queue for the case with Poisson arrivals and negative exponentially distributed service times. The bivariate generating function of the stationary joint
Distance estimation by computer vision and shortest path planning ...
African Journals Online (AJOL)
pc
2018-03-22
Mar 22, 2018 ... static or dynamic obstacle environment [1] [2] [3]. Several sensors as laser sensors, ultrasonic sensors ... decrement in processing time with higher speed. .... [1] A. Kynova, "Indoor Spatial Data Model for Wayfinding: A Case.
Distance estimation by computer vision and shortest path planning ...
African Journals Online (AJOL)
Journal Home > Vol 10, No 6S (2018) > ... The proposed way also detects and avoids obstacles in an environment using a single ... This paper has a great importance because of its fast execution speed also vision is a smart sensor as it helps ...
DFAs and PFAs with long shortest synchronizing word length
De Bondt, M.; Don, H.; Zantema, H.; Charlier, E.; Leroy, J.; Rigo, M.
2017-01-01
It was conjectured by Černý in 1964, that a synchronizing DFA on n states always has a synchronizing word of length at most (n-1)2 and he gave a sequence of DFAs for which this bound is reached. Until now a full analysis of all DFAs reaching this bound was only given for n ≤ 4 and with bounds on the
Dynamical diffraction in periodic multilayers
Sears, V F
1997-01-01
Exact reflectivity curves are calculated numerically for various periodic multilayers using the optical matrix method in order to test the dynamical theory of diffraction. The theory is generally valid for values of the bilayer thickness d up to about 100 A. For somewhat larger values of d, where the theory begins to break down, the initial discrepancy is in the phase of the oscillations in the wings of the peaks. For very large values of d, where the first-order Bragg peak approaches the edge of the mirror reflection, two general types of multilayers can be distinguished. In the first (typified in the present work by Ni/Ti), there is a large (30% or more) reduction in the actual value of the critical wave vector for total reflection while, in the second (typified here by Fe/Ge), there is very little reduction (3 % or so). The origin of these two very different types of behavior is explained. It is also shown that, within the dynamical theory of diffraction, the change in the position of the center of the Dar...
RADIO FLARING FROM THE T6 DWARF WISEPC J112254.73+255021.5 WITH A POSSIBLE ULTRA-SHORT PERIODICITY
Energy Technology Data Exchange (ETDEWEB)
Route, Matthew; Wolszczan, Alexander, E-mail: mroute@purdue.edu, E-mail: alex@astro.psu.edu [Department of Astronomy and Astrophysics, the Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)
2016-04-20
We present new results from a continuing 5 GHz search for flaring radio emission from a sample of L and T brown dwarfs, conducted with the 305 m Arecibo radio telescope. In addition to the previously reported flaring from the T6.5 dwarf 2MASS J10475385+212423, we have detected and confirmed circularly polarized flares from another T6 dwarf, WISEPC J112254.73+255021.5. Although the flares are sporadic, they appear to occur at a stable period of 0.288 hr. Given the current constraints, periods equal to its second and third subharmonic cannot be ruled out. The stability of this period over the eight-month timespan of observations indicates that, if real, it likely reflects the star’s rapid rotation. If confirmed, any of the three inferred periodicities would be much shorter than the shortest, 1.41 hr, rotation period of a brown dwarf measured so far. This finding would place a new observational constraint on the angular momentum evolution and rotational stability of substellar objects. The detection of radio emission from the sixth ∼1000 K dwarf further demonstrates that the coolest brown dwarfs and, possibly, young giant planets, can be efficiently investigated using radio observations at centimeter wavelengths as a tool.
RADIAL VELOCITY PLANETS DE-ALIASED: A NEW, SHORT PERIOD FOR SUPER-EARTH 55 Cnc e
International Nuclear Information System (INIS)
Dawson, Rebekah I.; Fabrycky, Daniel C.
2010-01-01
Radial velocity measurements of stellar reflex motion have revealed many extrasolar planets, but gaps in the observations produce aliases, spurious frequencies that are frequently confused with the planets' orbital frequencies. In the case of Gl 581 d, the distinction between an alias and the true frequency was the distinction between a frozen, dead planet and a planet possibly hospitable to life. To improve the characterization of planetary systems, we describe how aliases originate and present a new approach for distinguishing between orbital frequencies and their aliases. Our approach harnesses features in the spectral window function to compare the amplitude and phase of predicted aliases with peaks present in the data. We apply it to confirm prior alias distinctions for the planets GJ 876 d and HD 75898 b. We find that the true periods of Gl 581 d and HD 73526 b/c remain ambiguous. We revise the periods of HD 156668 b and 55 Cnc e, which were afflicted by daily aliases. For HD 156668 b, the correct period is 1.2699 days and the minimum mass is (3.1 ± 0.4) M + . For 55 Cnc e, the correct period is 0.7365 days-the shortest of any known planet-and the minimum mass is (8.3 ± 0.3) M + . This revision produces a significantly improved five-planet Keplerian fit for 55 Cnc, and a self-consistent dynamical fit describes the data just as well. As radial velocity techniques push to ever-smaller planets, often found in systems of multiple planets, distinguishing true periods from aliases will become increasingly important.
Crystallography beyond periodic Crystal perfection
International Nuclear Information System (INIS)
Estevez-Rams, E.
2008-01-01
Full text: The discovery of the quasi-crystals [D. Schechtman et. Al., Phys.] Rev. Lett. [53, 1951-1953 (1984)] made very narrow definition of the crystalline state based on the periodicity of a local arrangement of atoms. Since the definition of this State has been a matter of much controversy [G.R. Desiraju, Nature 423, 485 (2003); S. van Smaalen, IUCR Aperiodic Commission Reports. August 7, 2002; International Union of Crystallography. Report of the Executive Committee for 1991; ACTA Cryst. A48, 922-946 (1992)]. We will make a presentation of the current time of the crystallography in this regard from the conceptual point of view. We show the use of the formalism of algorithmic complexity or Kolmogorov [M. Li and P. Vitanyi, An Introduction to Kolmogorov Complexity and Its Applications (Springer Verlag, Heidelberg, 1993), W.H. Zurek, Phys.] Rev. 40, 4731 (1989); Nature 341, 119-124 (1989)] provides a different perspective on the nature of the Crystallographic order. Infinite crystals can be considered solid with zero algorithmic complexities by atom. Show statistical analysis of inorganic compounds [J.L.C. Daams et al., Atlas of Crystal Structure Types for Intermetallic Phases (ASM International, Ohio, 1991), Fachinformationszentrum/NIST Inorganic Crystal Structure Database, Karlsruhe (2003) icsd.fkf.mpg.de] demonstrating that the minimization of complexity is a trend in the crystalline arrangement. We will then compare the degree of disorder of some typical solids according to their algorithmic complexity. Finally, space diffraction will be studied from this same perspective and will be discussed that zero algorithmic complexities by point in space of diffraction does not necessarily imply the same thing for the Atomic arrangement. The discrete portion of the diffraction pattern is a fingerprint of the underlying order but not the actual existence of long-range order. Experimental results will be showcased [E. Estévez-Rams et al., Physical Review B, 63 (2001
Periodic precursors of nonlinear dynamical transitions
International Nuclear Information System (INIS)
Jiang Yu; Dong Shihai; Lozada-Cassou, M.
2004-01-01
We study the resonant response of a nonlinear system to external periodic perturbations. We show by numerical simulation that the periodic resonance curve may anticipate the dynamical instability of the unperturbed nonlinear periodic system, at parameter values far away from the bifurcation points. In the presence of noise, the buried intrinsic periodic dynamics can be picked out by analyzing the system's response to periodic modulation of appropriate intensity
Periodic Poisson Solver for Particle Tracking
International Nuclear Information System (INIS)
Dohlus, M.; Henning, C.
2015-05-01
A method is described to solve the Poisson problem for a three dimensional source distribution that is periodic into one direction. Perpendicular to the direction of periodicity a free space (or open) boundary is realized. In beam physics, this approach allows to calculate the space charge field of a continualized charged particle distribution with periodic pattern. The method is based on a particle mesh approach with equidistant grid and fast convolution with a Green's function. The periodic approach uses only one period of the source distribution, but a periodic extension of the Green's function. The approach is numerically efficient and allows the investigation of periodic- and pseudo-periodic structures with period lengths that are small compared to the source dimensions, for instance of laser modulated beams or of the evolution of micro bunch structures. Applications for laser modulated beams are given.
Unstable periodic orbits and chaotic economic growth
International Nuclear Information System (INIS)
Ishiyama, K.; Saiki, Y.
2005-01-01
We numerically find many unstable periodic solutions embedded in a chaotic attractor in a macroeconomic growth cycle model of two countries with different fiscal policies, and we focus on a special type of the unstable periodic solutions. It is confirmed that chaotic behavior represented by the model is qualitatively and quantitatively related to the unstable periodic solutions. We point out that the structure of a chaotic solution is dissolved into a class of finite unstable periodic solutions picked out among a large number of periodic solutions. In this context it is essential for the unstable periodic solutions to be embedded in the chaotic attractor
The Very Short Period M Dwarf Binary SDSS J001641-000925
Davenport, James R. A.; Becker, Andrew C.; West, Andrew A.; Bochanski, John J.; Hawley, Suzanne L.; Holtzman, Jon; Gunning, Heather C.; Hilton, Eric J.; Munshi, Ferah A.; Albright, Meagan
2013-02-01
We present follow-up observations and analysis of the recently discovered short period low-mass eclipsing binary, SDSS J001641-000925. With an orbital period of 0.19856 days, this system has one of the shortest known periods for an M dwarf binary system. Medium-resolution spectroscopy and multi-band photometry for the system are presented. Markov Chain Monte Carlo modeling of the light curves and radial velocities yields estimated masses for the stars of M 1 = 0.54 ± 0.07 M ⊙ and M 2 = 0.34 ± 0.04 M ⊙, and radii of R 1 = 0.68 ± 0.03 R ⊙ and R 2 = 0.58 ± 0.03 R ⊙, respectively. This solution places both components above the critical Roche overfill limit, providing strong evidence that SDSS J001641-000925 is the first verified M-dwarf contact binary system. Within the follow-up spectroscopy we find signatures of non-solid body rotation velocities, which we interpret as evidence for mass transfer or loss within the system. In addition, our photometry samples the system over nine years, and we find strong evidence for period decay at the rate of \\dot{P}\\sim 8 s yr-1. Both of these signatures raise the intriguing possibility that the system is in over-contact, and actively losing angular momentum, likely through mass loss. This places SDSS J001641-000925 as not just the first M-dwarf over-contact binary, but one of the few systems of any spectral type known to be actively undergoing coalescence. Further study of SDSS J001641-000925 is ongoing to verify the nature of the system, which may prove to be a unique astrophysical laboratory. Based on observations obtained with the Apache Point Observatory 3.5 m telescope, which is owned and operated by the Astrophysical Research Consortium. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile. Support for the design and construction of the Magellan Echellette Spectrograph was received from the Observatories of the Carnegie Institution of Washington, the
Depression in pregnancy and postpartum period.
Sood, Mamta; Sood, A K
2003-01-01
This prospective study was carried out in a service hospital, with the aim to study the prevalence and incidence of depression in pregnancy and postpartum period. Eighty Four consecutive patients attending the antenatal outpatient in the Obstetrics & Gynaecology department in their last trimester of pregnancy were recruited for the study. They were assessed on Beck Depression Inventory thrice viz. during third trimester of pregnancy, within 3 days of delivery (early postpartum period) & within 4-8 weeks of delivery (late postpartum period).The prevalence of depression was 8.3%, 20% and 12.8% respectively at three ratings. The incidence was 16% and 10% in the early & late postpartum period respectively. Further analysis revealed that depression in pregnancy correlated significantly with depression in early postpartum period, but not with late postpartum period. Depression in early postpartum period correlated with depression in late postpartum period.These findings have implications for early detection and care of women at risk for developing depression.
Periodic solutions of nonlinear vibrating beams
Directory of Open Access Journals (Sweden)
J. Berkovits
2003-01-01
Full Text Available The aim of this paper is to prove new existence and multiplicity results for periodic semilinear beam equation with a nonlinear time-independent perturbation in case the period is not prescribed. Since the spectrum of the linear part varies with the period, the solvability of the equation depends crucially on the period which can be chosen as a free parameter. Since the period of the external forcing is generally unknown a priori, we consider the following natural problem. For a given time-independent nonlinearity, find periods T for which the equation is solvable for any T-periodic forcing. We will also deal with the existence of multiple solutions when the nonlinearity interacts with the spectrum of the linear part. We show that under certain conditions multiple solutions do exist for any small forcing term with suitable period T. The results are obtained via generalized Leray-Schauder degree and reductions to invariant subspaces.
21 CFR 573.240 - Calcium periodate.
2010-04-01
... with calcium hydroxide or calcium oxide to form a substance consisting of not less than 60 percent by... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium periodate. 573.240 Section 573.240 Food... Additive Listing § 573.240 Calcium periodate. The food additive calcium periodate may be safely used in...
2010-07-01
... 39 Postal Service 1 2010-07-01 2010-07-01 false Periodicals. 121.2 Section 121.2 Postal Service UNITED STATES POSTAL SERVICE POST OFFICE SERVICES [DOMESTIC MAIL] SERVICE STANDARDS FOR MARKET-DOMINANT MAIL PRODUCTS § 121.2 Periodicals. (a) End-to-End. (1) For all SCF turnaround Periodicals properly...
27 CFR 70.244 - Payroll period.
2010-04-01
... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Payroll period. 70.244... Excise and Special (Occupational) Tax Limitations § 70.244 Payroll period. For purpose of determining the... established calendar period regularly used by the employer or other person levied upon for payroll or payment...
40 CFR 35.9035 - Budget period.
2010-07-01
... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Budget period. 35.9035 Section 35.9035... ASSISTANCE Financial Assistance for the National Estuary Program § 35.9035 Budget period. An applicant may choose its budget period in consultation with and subject to the approval of the Regional Administrator. ...
10 CFR 603.1295 - Periodic audit.
2010-01-01
... 10 Energy 4 2010-01-01 2010-01-01 false Periodic audit. 603.1295 Section 603.1295 Energy... Used in this Part § 603.1295 Periodic audit. An audit of a participant, performed at an agreed-upon... an audit may cover. A periodic audit of a participant differs from an award-specific audit of an...
32 CFR 37.1325 - Periodic audit.
2010-07-01
... 32 National Defense 1 2010-07-01 2010-07-01 false Periodic audit. 37.1325 Section 37.1325 National... TECHNOLOGY INVESTMENT AGREEMENTS Definitions of Terms Used in This Part § 37.1325 Periodic audit. An audit of... awards. Appendix C to this part describes what such an audit may cover. A periodic audit of a participant...
49 CFR 236.588 - Periodic test.
2010-10-01
... 49 Transportation 4 2010-10-01 2010-10-01 false Periodic test. 236.588 Section 236.588..., Train Control and Cab Signal Systems Inspection and Tests; Locomotive § 236.588 Periodic test. Except as provided in § 236.586, periodic test of the automatic train stop, train control, or cab signal apparatus...
47 CFR 22.1035 - Construction period.
2010-10-01
... 47 Telecommunication 2 2010-10-01 2010-10-01 false Construction period. 22.1035 Section 22.1035 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PUBLIC MOBILE SERVICES Offshore Radiotelephone Service § 22.1035 Construction period. The construction period (see § 22.142) for...
Handgun waiting periods reduce gun deaths.
Luca, Michael; Malhotra, Deepak; Poliquin, Christopher
2017-11-14
Handgun waiting periods are laws that impose a delay between the initiation of a purchase and final acquisition of a firearm. We show that waiting periods, which create a "cooling off" period among buyers, significantly reduce the incidence of gun violence. We estimate the impact of waiting periods on gun deaths, exploiting all changes to state-level policies in the Unites States since 1970. We find that waiting periods reduce gun homicides by roughly 17%. We provide further support for the causal impact of waiting periods on homicides by exploiting a natural experiment resulting from a federal law in 1994 that imposed a temporary waiting period on a subset of states. Copyright © 2017 the Author(s). Published by PNAS.
A highly specific test for periodicity
Energy Technology Data Exchange (ETDEWEB)
Ansmann, Gerrit, E-mail: gansmann@uni-bonn.de [Department of Epileptology, University of Bonn, Sigmund-Freud-Straße 25, 53105 Bonn (Germany); Helmholtz Institute for Radiation and Nuclear Physics, University of Bonn, Nussallee 14–16, 53115 Bonn (Germany); Interdisciplinary Center for Complex Systems, University of Bonn, Brühler Straße 7, 53175 Bonn (Germany)
2015-11-15
We present a method that allows to distinguish between nearly periodic and strictly periodic time series. To this purpose, we employ a conservative criterion for periodicity, namely, that the time series can be interpolated by a periodic function whose local extrema are also present in the time series. Our method is intended for the analysis of time series generated by deterministic time-continuous dynamical systems, where it can help telling periodic dynamics from chaotic or transient ones. We empirically investigate our method's performance and compare it to an approach based on marker events (or Poincaré sections). We demonstrate that our method is capable of detecting small deviations from periodicity and outperforms the marker-event-based approach in typical situations. Our method requires no adjustment of parameters to the individual time series, yields the period length with a precision that exceeds the sampling rate, and its runtime grows asymptotically linear with the length of the time series.
A highly specific test for periodicity
International Nuclear Information System (INIS)
Ansmann, Gerrit
2015-01-01
We present a method that allows to distinguish between nearly periodic and strictly periodic time series. To this purpose, we employ a conservative criterion for periodicity, namely, that the time series can be interpolated by a periodic function whose local extrema are also present in the time series. Our method is intended for the analysis of time series generated by deterministic time-continuous dynamical systems, where it can help telling periodic dynamics from chaotic or transient ones. We empirically investigate our method's performance and compare it to an approach based on marker events (or Poincaré sections). We demonstrate that our method is capable of detecting small deviations from periodicity and outperforms the marker-event-based approach in typical situations. Our method requires no adjustment of parameters to the individual time series, yields the period length with a precision that exceeds the sampling rate, and its runtime grows asymptotically linear with the length of the time series
Ringing of White Storks Ciconia ciconia in NE Slovenia during the 1984–2013 period
Directory of Open Access Journals (Sweden)
Bračko Franc
2016-12-01
Full Text Available In a period of 30 years (1984-2013, 1,535 White Stork pulli were ringed on nest and 1,226 nests examined in NE Slovenia. The ringing was implemented in the regions of Dravsko polje, Slovenske gorice and Pomurje. In each season, from 9 to 85 nests were examined, the great majority of them built on overhead powerline pylons. On average, 51.16 pulli or 16.66% were ringed and 40.86 or 18.91% nests visited compared to the census of fledged pulli and inventoried nests in 1999 in NE Slovenia. A total of 71 finds or 4.6% were registered and 37 rings or 52% finds read. There were 26 (36.62% local recoveries, while in foreign countries 34 (47.88% recoveries of Slovenian-ringed storks were made. Two of our recoveries were registered abroad prior to 1984. There were 11 (15.49% foreign recoveries. Local recoveries (n = 26 indicate breeding relationship (mixing between the eastern and southern Slovenian breeding populations. The longest distance of breeding was 115 km in a beeline, the shortest 62 km (n = 4. Other 12 local recoveries at 1 to 38 km from the place of hatching concerns the native NE breeding area. Young sexually mature storks search for new breeding sites only in their fourth year of age. No ringed stork returned to the native nest as a young breeder. The oldest was 14 years old. Some of them breed in the wider area of the Pannonian Plain outside Slovenia, e.g. 3 in Austria, 2 in Serbia and 1 in Croatia. One of them bred in Slovakia 463 km away. In view of the presented recoveries it has been ascertained that the storks from NE Slovenia migrate across the Pannonian Plain, the Balkans and Asia Minor, down to the South African Republic of 8,923 km in a beeline (4 recoveries, using the eastern migration route. The western migration route was not ascertained. The majority of recoveries originated from the autumn migration period, with only one recovery known from the spring migration period. No less than 23 ringed storks, particularly young ones
Seismic isolation of two dimensional periodic foundations
International Nuclear Information System (INIS)
Yan, Y.; Mo, Y. L.; Laskar, A.; Cheng, Z.; Shi, Z.; Menq, F.; Tang, Y.
2014-01-01
Phononic crystal is now used to control acoustic waves. When the crystal goes to a larger scale, it is called periodic structure. The band gaps of the periodic structure can be reduced to range from 0.5 Hz to 50 Hz. Therefore, the periodic structure has potential applications in seismic wave reflection. In civil engineering, the periodic structure can be served as the foundation of upper structure. This type of foundation consisting of periodic structure is called periodic foundation. When the frequency of seismic waves falls into the band gaps of the periodic foundation, the seismic wave can be blocked. Field experiments of a scaled two dimensional (2D) periodic foundation with an upper structure were conducted to verify the band gap effects. Test results showed the 2D periodic foundation can effectively reduce the response of the upper structure for excitations with frequencies within the frequency band gaps. When the experimental and the finite element analysis results are compared, they agree well with each other, indicating that 2D periodic foundation is a feasible way of reducing seismic vibrations.
Discrete symmetries in periodic-orbit theory
International Nuclear Information System (INIS)
Robbins, J.M.
1989-01-01
The application of periodic-orbit theory to systems which possess a discrete symmetry is considered. A semiclassical expression for the symmetry-projected Green's function is obtained; it involves a sum over classical periodic orbits on a symmetry-reduced phase space, weighted by characters of the symmetry group. These periodic orbits correspond to trajectories on the full phase space which are not necessarily periodic, but whose end points are related by symmetry. If the symmetry-projected Green's functions are summed, the contributions of the unperiodic orbits cancel, and one recovers the usual periodic-orbit sum for the full Green's function. Several examples are considered, including the stadium billiard, a particle in a periodic potential, the Sinai billiard, the quartic oscillator, and the rotational spectrum of SF 6
How periodic are terahertz quantum cascade lasers?
International Nuclear Information System (INIS)
Kubis, T; Vogl, P
2009-01-01
We apply a novel non-equilibrium Green's function method for open quantum devices to analyze quantum cascade lasers. We find the carrier distribution in typical resonant phonon THz-QCLs to develop a periodicity that differs from the geometric periodicity of the QCL. We propose a design improvement that thermalizes electrons at threshold bias and thereby pins the electron density to the QCL periodicity.
How periodic are terahertz quantum cascade lasers?
Energy Technology Data Exchange (ETDEWEB)
Kubis, T; Vogl, P, E-mail: tillmann.kubis@wsi.tum.d [Walter Schottky Institute, Technische Universitaet Muenchen, Am Coulombwall 3, 85748 Garching (Germany)
2009-11-15
We apply a novel non-equilibrium Green's function method for open quantum devices to analyze quantum cascade lasers. We find the carrier distribution in typical resonant phonon THz-QCLs to develop a periodicity that differs from the geometric periodicity of the QCL. We propose a design improvement that thermalizes electrons at threshold bias and thereby pins the electron density to the QCL periodicity.
Southern hemisphere searches for short period pulsars
International Nuclear Information System (INIS)
Manchester, R.N.
1984-01-01
Two searches of the southern sky for short period pulsars are briefly described. The first, made using the 64-m telescope at Parkes, is sensitive to pulsars with periods greater than about 10 ms and the second, made using the Molonglo radio telescope, has sensitivity down to periods of about 1.5 ms. Four pulsars were found in the Parkes survey and none in the Molonglo survey, although analysis of the latter is as yet incomplete. 10 references, 1 figure, 2 tables
Long-Period Variability in o Ceti
Templeton, Matthew R.; Karovska, Margarita
2009-02-01
We carried out a new and sensitive search for long-period variability in the prototype of the Mira class of long-period pulsating variables, o Ceti (Mira A), the closest and brightest Mira variable. We conducted this search using an unbroken light curve from 1902 to the present, assembled from the visual data archives of five major variable star observing organizations from around the world. We applied several time-series analysis techniques to search for two specific kinds of variability: long secondary periods (LSPs) longer than the dominant pulsation period of ~333 days, and long-term period variation in the dominant pulsation period itself. The data quality is sufficient to detect coherent periodic variations with photometric amplitudes of 0.05 mag or less. We do not find evidence for coherent LSPs in o Ceti to a limit of 0.1 mag, where the amplitude limit is set by intrinsic, stochastic, low-frequency variability of approximately 0.1 mag. We marginally detect a slight modulation of the pulsation period similar in timescale to that observed in the Miras with meandering periods, but with a much lower period amplitude of ±2 days. However, we do find clear evidence of a low-frequency power-law component in the Fourier spectrum of o Ceti's long-term light curve. The amplitude of this stochastic variability is approximately 0.1 mag at a period of 1000 days, and it exhibits a turnover for periods longer than this. This spectrum is similar to the red noise spectra observed in red supergiants.
Epidural Analgesia in the Postoperative Period
National Research Council Canada - National Science Library
Mathsen, Curtis
2001-01-01
.... This descriptive study was conducted to determine which surgical patients experienced the most analgesia with the fewest side effects when receiving epidural analgesia in the postoperative period...
Project 2nd Periodic Report - Section 2
DEFF Research Database (Denmark)
Healy, Mark; Knowles, Emma; Johnstone, Cameron
The work described in this publication has received support from the European Community - Research Infrastructure Action under the FP7 “Capacities” Specific Programme through grant agreement number 262552, MaRINET. Project Periodic Report. 2nd Period: October 2012 – March 2014 inclusive.......The work described in this publication has received support from the European Community - Research Infrastructure Action under the FP7 “Capacities” Specific Programme through grant agreement number 262552, MaRINET. Project Periodic Report. 2nd Period: October 2012 – March 2014 inclusive....
Periodic Continuing Disability Review Case Backlog
Social Security Administration — The Social Security Administration (SSA) conducts periodic CDRs to ensure that only those beneficiaries who remain disabled continue to receive monthly benefits. The...
38 CFR 3.252 - Annual income; pension; Mexican border period and later war periods.
2010-07-01
...; Mexican border period and later war periods. 3.252 Section 3.252 Pensions, Bonuses, and Veterans' Relief... Dependency, Income and Estate § 3.252 Annual income; pension; Mexican border period and later war periods. (a) Annual income limitations; old-law pension. Where the right to old-law pension is payable under section...
46 CFR 403.115 - Accounting period.
2010-10-01
... 46 Shipping 8 2010-10-01 2010-10-01 false Accounting period. 403.115 Section 403.115 Shipping COAST GUARD (GREAT LAKES PILOTAGE), DEPARTMENT OF HOMELAND SECURITY GREAT LAKES PILOTAGE UNIFORM ACCOUNTING SYSTEM General § 403.115 Accounting period. Each Association subject to this part shall maintain...
18 CFR 367.5 - Accounting period.
2010-04-01
... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Accounting period. 367.5 Section 367.5 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION... Instructions § 367.5 Accounting period. Each service company must keep its books on a monthly basis so that for...
24 CFR 221.775 - Option period.
2010-04-01
... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Option period. 221.775 Section 221.775 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... § 221.775 Option period. The mortgagee may exercise its option to assign within one year following the...
42 CFR 409.60 - Benefit periods.
2010-10-01
... 42 Public Health 2 2010-10-01 2010-10-01 false Benefit periods. 409.60 Section 409.60 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE PROGRAM HOSPITAL INSURANCE BENEFITS Scope of Hospital Insurance Benefits § 409.60 Benefit periods. (a) When benefit...
28 CFR 524.75 - Periodic review.
2010-07-01
... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Periodic review. 524.75 Section 524.75... TRANSFER CLASSIFICATION OF INMATES Central Inmate Monitoring (CIM) System § 524.75 Periodic review. The Warden shall ensure that the status of an inmate's CIM assignment is considered at each program review...
50 CFR 424.21 - Periodic review.
2010-10-01
... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Periodic review. 424.21 Section 424.21... SPECIES AND DESIGNATING CRITICAL HABITAT Revision of the Lists § 424.21 Periodic review. At least once every 5 years, the Secretary shall conduct a review of each listed species to determine whether it...
Attractors for discrete periodic dynamical systems
John E. Franke; James F. Selgrade
2003-01-01
A mathematical framework is introduced to study attractors of discrete, nonautonomous dynamical systems which depend periodically on time. A structure theorem for such attractors is established which says that the attractor of a time-periodic dynamical system is the unin of attractors of appropriate autonomous maps. If the nonautonomous system is a perturbation of an...
Discontinuous Spirals of Stable Periodic Oscillations
DEFF Research Database (Denmark)
Sack, Achim; Freire, Joana G.; Lindberg, Erik
2013-01-01
We report the experimental discovery of a remarkable organization of the set of self-generated periodic oscillations in the parameter space of a nonlinear electronic circuit. When control parameters are suitably tuned, the wave pattern complexity of the periodic oscillations is found to increase...
Multi-periodic nanostructures for photon control
DEFF Research Database (Denmark)
Kluge, Christian; Adam, Jost; Barié, Nicole
2014-01-01
We propose multi-periodic nanostructures yielded by superposition of multiple binary gratings for wide control over photon emission in thin-film devices. We present wavelength- and angle-resolved photoluminescence measurements of multi-periodically nanostructured organic light-emitting layers...
Quantized gauge invariant periodic TDHF solutions
International Nuclear Information System (INIS)
Kan, K.-K.; Griffin, J.J.; Lichtner, P.C.; Dworzecka, M.
1979-01-01
Time-dependent Hartree-Fock (TDHF) is used to study steady state large amplitude nuclear collective motions, such as vibration and rotation. As is well known the small amplitude TDHF leads to the RPA equation. The analysis of periodicity in TDHF is not trivial because TDHF is a nonlinear theory and it is not known under what circumstances a nonlinear theory can support periodic solutions. It is also unknown whether such periodic solution, if they exist, form a continuous or a discrete set. But, these properties may be important in obtaining the energy spectrum of the collective states from the TDHF description. The periodicity and Gauge Invariant Periodicity of solutions are investigated for that class of models whose TDHF solutions depend on time through two parameters. In such models TDHF supports a continuous family of periodic solutions, but only a discrete subset of these is gauge invariant. These discrete Gauge Invariant Periodic solutions obey the Bohr-Summerfeld quantization rule. The energy spectrum of the Gauge Invariant Periodic solutions is compared with the exact eigenergies in one specific example
20 CFR 410.501 - Payment periods.
2010-04-01
... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Payment periods. 410.501 Section 410.501 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL COAL MINE HEALTH AND SAFETY ACT OF 1969, TITLE IV-BLACK LUNG BENEFITS (1969- ) Payment of Benefits § 410.501 Payment periods. Benefits are paid to...
The decreasing period of AG Phe
International Nuclear Information System (INIS)
Cerruti, M.A.
1986-01-01
Seven UBV photoelectric times of minimum light are presented. They shift the photographically known period 0 . d 613 to 0 . d 380. The improvement of the light elements leads to a reliable shortening of the period. A rough determination of the mass-ratio permitted to give an estimate of the mass transfer in the system. 13 refs., 1 fig., 1 tab. (author)
Selecting Full-Text Undergraduate Periodicals Databases.
Still, Julie M.; Kassabian, Vibiana
1999-01-01
Examines how libraries and librarians can compare full-text general periodical indices, using ProQuest Direct, Periodical Abstracts (via Ovid), and EBSCOhost as examples. Explores breadth and depth of coverage; manipulation of results (email/download/print); ease of use (searching); and indexing quirks. (AEF)
20 CFR 655.205 - Recruitment period.
2010-04-01
... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Recruitment period. 655.205 Section 655.205... FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Logging Employment and Non-H-2A Agricultural Employment § 655.205 Recruitment period. (a) If the OFLC Administrator determines that the...
Buffer Overflow Period in a MAP Queue
Directory of Open Access Journals (Sweden)
Andrzej Chydzinski
2007-01-01
Full Text Available The buffer overflow period in a queue with Markovian arrival process (MAP and general service time distribution is investigated. The results include distribution of the overflow period in transient and stationary regimes and the distribution of the number of cells lost during the overflow interval. All theorems are illustrated via numerical calculations.
Shock dynamics in layered periodic media
Ketcheson, David I.; Leveque, Randall J.
2012-01-01
of shock waves in a one-dimensional periodic layered medium by a computational study of time-reversibility and entropy evolution. We find that periodic layered media tend to inhibit shock formation. For small initial conditions and large impedance variation
Survival period, infectivity and morphological composition of ...
African Journals Online (AJOL)
Open Access DOWNLOAD FULL TEXT ... At the end of each maintenance period (hours), three clean albino mice were ... for up to 12 and 24 hours respectively were infective for the mice inoculation test. ... period (21.0days) higher peak parasitaemia (15-20 parasites per field) and higher population of slender forms.
Online Periodic Table: A Cautionary Note
Izci, Kemal; Barrow, Lloyd H.; Thornhill, Erica
2013-01-01
The purpose of this study was (a) to evaluate ten online periodic table sources for their accuracy and (b) to compare the types of information and links provided to users. Limited studies have been reported on online periodic table (Diener and Moore 2011; Slocum and Moore in "J Chem Educ" 86(10):1167, 2009). Chemistry students'…
The periodic table of elementary particles
International Nuclear Information System (INIS)
Bhattacharjee, B.J.
1994-01-01
It is shown that a periodic classification of elementary particles (eps) may be done with the basic properties of eps: viz. mass, spin and parity. Further application of spacing rule and GMO mass formulae show repetitions at very regular intervals. It is found that properties of eps are periodic function of rest mass. (author). 17 refs., 6 tabs
The periodic table of elementary particles
Energy Technology Data Exchange (ETDEWEB)
Bhattacharjee, B J [St. Anthony' s College, Shillong (India). Dept. of Physics
1994-01-01
It is shown that a periodic classification of elementary particles (eps) may be done with the basic properties of eps: viz. mass, spin and parity. Further application of spacing rule and GMO mass formulae show repetitions at very regular intervals. It is found that properties of eps are periodic function of rest mass. (author). 17 refs., 6 tabs.
12 CFR 226.7 - Periodic statement.
2010-01-01
... consumer with a periodic statement that discloses the following items, to the extent applicable: (a... convenience of the user, the revised text is set forth as follows: § 226.7 Periodic statement. (a) Rules... consumers may obtain from the creditor more information about the balance computation method and how...
5 CFR 9901.512 - Probationary periods.
2010-01-01
... 9901.512 Administrative Personnel DEPARTMENT OF DEFENSE HUMAN RESOURCES MANAGEMENT AND LABOR RELATIONS SYSTEMS (DEPARTMENT OF DEFENSE-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF DEFENSE NATIONAL SECURITY... Probationary periods. (a) Initial probationary period. (1) An employee who is given a career, career...
Resonances in a periodically driven bosonic system
Quelle, Anton; de Morais Smith, Cristiane
2017-01-01
Periodically driven systems are a common topic in modern physics. In optical lattices specifically, driving is at the origin of many interesting phenomena. However, energy is not conserved in driven systems, and under periodic driving, heating of a system is a real concern. In an effort to better
Almost periodic Hamiltonians: an algebraic approach
International Nuclear Information System (INIS)
Bellissard, J.
1981-07-01
We develop, by analogy with the study of periodic potential, an algebraic theory for almost periodic hamiltonians, leading to a generalized Bloch theorem. This gives rise to results concerning the spectral measures of these operators in terms of those of the corresponding Bloch hamiltonians
Period Variations for the Cepheid VZ Cyg
Sirorattanakul, Krittanon; Engle, Scott; Pepper, Joshua; Wells, Mark; Laney, Clifton D.; Rodriguez, Joseph E.; Stassun, Keivan G.
2017-12-01
The Cepheid Period-Luminosity law is a key rung on the extragalactic distance ladder. However, numerous Cepheids are known to undergo period variations. Monitoring, refining, and understanding these period variations allows us to better determine the parameters of the Cepheids themselves and of the instability strip in which they reside, and to test models of stellar evolution. VZ Cyg, a classical Cepheid pulsating at ˜4.864 days, has been observed for over 100 years. Combining data from literature observations, the Kilodegree Extremely Little Telescope (KELT) transit survey, and new targeted observations with the Robotically Controlled Telescope (RCT) at Kitt Peak, we find a period change rate of dP/dt = -0.0642 ± 0.0018 s yr-1. However, when only the recent observations are examined, we find a much higher period change rate of dP/dt = -0.0923 ± 0.0110 s yr-1. This higher rate could be due to an apparent long-term (P ≈ 26.5 years) cyclic period variation. The possible interpretations of this single Cepheid’s complex period variations underscore both the need to regularly monitor pulsating variables and the important benefits that photometric surveys such as KELT can have on the field. Further monitoring of this interesting example of Cepheid variability is recommended to confirm and better understand the possible cyclic period variations. Further, Cepheid timing analyses are necessary to fully understand their current behaviors and parameters, as well as their evolutionary histories.
David's Understanding of Functions and Periodicity
Gerson, Hope
2008-01-01
This is a study of David, a senior enrolled in a high school precalculus course. David's understandings of functions and periodicity was explored, through clinical interviews and contextualized through classroom observations. Although David's precalculus class was traditional his understanding of periodic functions was unconventional David engaged…
Periodization Theory: Confronting an Inconvenient Truth.
Kiely, John
2018-04-01
Periodization theory has, over the past seven decades, emerged as the preeminent training planning paradigm. The philosophical underpinnings of periodization theory can be traced back to the integration of diverse shaping influences, whereby coaching beliefs and traditions were blended with historically available scientific insights and contextualized against pervading social planning models. Since then, many dimensions of elite preparation have evolved significantly, as driven by a combination of coaching innovations and science-led advances in training theory, techniques, and technologies. These advances have been incorporated into the fabric of the pre-existing periodization planning framework, yet the philosophical assumptions underpinning periodization remain largely unchallenged and unchanged. One particularly influential academic sphere of study, the science of stress, particularly the work of Hans Selye, is repeatedly cited by theorists as a central pillar upon which periodization theory is founded. A fundamental assumption emanating from the early stress research is that physical stress is primarily a biologically mediated phenomenon: a presumption translated to athletic performance contexts as evidence that mechanical training stress directly regulates the magnitude of subsequent 'fitness' adaptations. Interestingly, however, since periodization theory first emerged, the science of stress has evolved extensively from its historical roots. This raises a fundamental question: if the original scientific platform upon which periodization theory was founded has disintegrated, should we critically re-evaluate conventional perspectives through an updated conceptual lens? Realigning periodization philosophy with contemporary stress theory thus presents us with an opportunity to recalibrate training planning models with both contemporary scientific insight and progressive coaching practice.
Periodic and secular changes in SS 433
International Nuclear Information System (INIS)
Collins, G.W.; Newsom, G.H.
1983-01-01
The recent history of SS 433 is reviewed with particular attention being given to the discovery of the periodic phenomena displayed by this object. Several periods ranging from days to months are established as being present in the spectrum of the ''moving'' lines as well as in other aspects of the emission from the object. In addition evidence for secular change in some of the defining parameters of the system is presented. Although these secular changes may eventually prove to be periodic on a rather long time scale, some interpretation of both the periodic and secular phenomena is possible. It is shown that it is possible to interpret all the known periodic phenomena in terms of a processing object responding to the time-varying torques that one would expect in a binary system
Hypokalemic periodic paralysis: Three rare secondary causes
Directory of Open Access Journals (Sweden)
Prasanna Eswaradass Venkatesan
2015-01-01
Full Text Available Periodic paralysis is a rare neuromuscular disorder, related to a defect in muscle ion channels, characterized by episodes of painless muscle weakness, which may be precipitated by heavy exercise, fasting, or high-carbohydrate meals. Hypokalemic periodic paralysis may be familial (primary or secondary. Here, we report three cases of secondary causes of hypokalemic periodic paralysis. On evaluation, case 1 had distal renal tubular acidosis (RTA due to Sjogren′s syndrome, case 2 had drug induced proximal RTA (Fanconi′s syndrome and case 3 had thyrotoxicosis. Clinician must be aware of causes of secondary PP as recognition and diagnosis can completely prevent further attacks of periodic paralysis. Each of the above case is rare, but completely treatable if diagnosed. Low dose steroids with bicarbonate replacement in case 1, stopping tenofovir in case 2 and carbimazole therapy in case 3 prevented further attacks of periodic paralysis and cardiopulmonary complications.
Periodic-cylinder vesicle with minimal energy
International Nuclear Information System (INIS)
Xiao-Hua, Zhou
2010-01-01
We give some details about the periodic cylindrical solution found by Zhang and Ou-Yang in [1996 Phys. Rev. E 53 4206] for the general shape equation of vesicle. Three different kinds of periodic cylindrical surfaces and a special closed cylindrical surface are obtained. Using the elliptic functions contained in mathematic, we find that this periodic shape has the minimal total energy for one period when the period–amplitude ratio β ≈ 1.477, and point out that it is a discontinuous deformation between plane and this periodic shape. Our results also are suitable for DNA and multi-walled carbon nanotubes (MWNTs). (cross-disciplinary physics and related areas of science and technology)
The early period of the calculus of variations
Freguglia, Paolo
2016-01-01
This monograph explores the early development of the calculus of variations in continental Europe during the Eighteenth Century by illustrating the mathematics of its founders. Closely following the original papers and correspondences of Euler, Lagrange, the Bernoullis, and others, the reader is immersed in the challenge of theory building. We see what the founders were doing, the difficulties they faced, the mistakes they made, and their triumphs. The authors guide the reader through these works with instructive commentaries and complements to the original proofs, as well as offering a modern perspective where useful. The authors begin in 1697 with Johann Bernoulli’s work on the brachystochrone problem and the events leading up to it, marking the dawn of the calculus of variations. From there, they cover key advances in the theory up to the development of Lagrange’s δ-calculus, including: • The isoperimetrical problems • Shortest lines and geodesics • Euler’s Methodus Inveniendi and the two Addi...
Variable-Period Undulators for Synchrotron Radiation
Energy Technology Data Exchange (ETDEWEB)
Shenoy, Gopal; Lewellen, John; Shu, Deming; Vinokurov, Nikolai
2005-02-22
A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.
Variable-Period Undulators For Synchrotron Radiation
Shenoy, Gopal; Lewellen, John; Shu, Deming; Vinokurov, Nikolai
2005-02-22
A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high-energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.
Optimal glucose management in the perioperative period.
Evans, Charity H; Lee, Jane; Ruhlman, Melissa K
2015-04-01
Hyperglycemia is a common finding in surgical patients during the perioperative period. Factors contributing to poor glycemic control include counterregulatory hormones, hepatic insulin resistance, decreased insulin-stimulated glucose uptake, use of dextrose-containing intravenous fluids, and enteral and parenteral nutrition. Hyperglycemia in the perioperative period is associated with increased morbidity, decreased survival, and increased resource utilization. Optimal glucose management in the perioperative period contributes to reduced morbidity and mortality. To readily identify hyperglycemia, blood glucose monitoring should be instituted for all hospitalized patients. Published by Elsevier Inc.
Convectons in periodic and bounded domains
International Nuclear Information System (INIS)
Mercader, Isabel; Batiste, Oriol; Alonso, Arantxa; Knobloch, Edgar
2010-01-01
Numerical continuation is used to compute spatially localized convection in a binary fluid with no-slip laterally insulating boundary conditions and the results are compared with the corresponding ones for periodic boundary conditions (PBC). The change in the boundary conditions produces a dramatic change in the snaking bifurcation diagram that describes the organization of localized states with PBC: the snaking branches turn continuously into a large amplitude state that resembles periodic convection with defects at the sidewalls. Odd parity convectons are more affected by the boundary conditions since the sidewalls suppress the horizontal pumping action that accompanies these states in spatially periodic domains.
Convectons in periodic and bounded domains
Energy Technology Data Exchange (ETDEWEB)
Mercader, Isabel; Batiste, Oriol; Alonso, Arantxa [Departament de Fisica Aplicada, Universitat Politecnica de Catalunya, Barcelona (Spain); Knobloch, Edgar [Department of Physics, University of California, Berkeley, CA 94720 (United States)
2010-04-15
Numerical continuation is used to compute spatially localized convection in a binary fluid with no-slip laterally insulating boundary conditions and the results are compared with the corresponding ones for periodic boundary conditions (PBC). The change in the boundary conditions produces a dramatic change in the snaking bifurcation diagram that describes the organization of localized states with PBC: the snaking branches turn continuously into a large amplitude state that resembles periodic convection with defects at the sidewalls. Odd parity convectons are more affected by the boundary conditions since the sidewalls suppress the horizontal pumping action that accompanies these states in spatially periodic domains.
Diffraction Theory and Almost Periodic Distributions
Strungaru, Nicolae; Terauds, Venta
2016-09-01
We introduce and study the notions of translation bounded tempered distributions, and autocorrelation for a tempered distribution. We further introduce the spaces of weakly, strongly and null weakly almost periodic tempered distributions and show that for weakly almost periodic tempered distributions the Eberlein decomposition holds. For translation bounded measures all these notions coincide with the classical ones. We show that tempered distributions with measure Fourier transform are weakly almost periodic and that for this class, the Eberlein decomposition is exactly the Fourier dual of the Lebesgue decomposition, with the Fourier-Bohr coefficients specifying the pure point part of the Fourier transform. We complete the project by looking at few interesting examples.
Attractors of the periodically forced Rayleigh system
Directory of Open Access Journals (Sweden)
Petre Bazavan
2011-07-01
Full Text Available The autonomous second order nonlinear ordinary differential equation(ODE introduced in 1883 by Lord Rayleigh, is the equation whichappears to be the closest to the ODE of the harmonic oscillator withdumping.In this paper we present a numerical study of the periodic andchaotic attractors in the dynamical system associated with the generalized Rayleigh equation. Transition between periodic and quasiperiodic motion is also studied. Numerical results describe the system dynamics changes (in particular bifurcations, when the forcing frequency is varied and thus, periodic, quasiperiodic or chaotic behaviour regions are predicted.
Periodicity in Age-Resolved Populations
Esipov, Sergei
We discuss the interplay between the non-linear diffusion and age-resolved population dynamics. Depending on the age properties of collective migration the system may exhibit continuous joint expansion of all ages or continuous expansion with age segregation. Between these two obvious limiting regimes there is an interesting window of periodic expansion, which has been previously used by us in modeling bacterial colonies of Proteus mirabilis. In order to test whether the age-dependent collective migration leads to periodicity in other systems we performed a Fourier analysis of historical data on ethnic expansions and found multiple co-existing periods of activity.
Periodic solutions of dissipative systems revisited
Directory of Open Access Journals (Sweden)
Górniewicz Lech
2006-01-01
Full Text Available We reprove in an extremely simple way the classical theorem that time periodic dissipative systems imply the existence of harmonic periodic solutions, in the case of uniqueness. We will also show that, in the lack of uniqueness, the existence of harmonics is implied by uniform dissipativity. The localization of starting points and multiplicity of periodic solutions will be established, under suitable additional assumptions, as well. The arguments are based on the application of various asymptotic fixed point theorems of the Lefschetz and Nielsen type.
Periodic solutions of dissipative systems revisited
Directory of Open Access Journals (Sweden)
Lech Górniewicz
2006-05-01
Full Text Available We reprove in an extremely simple way the classical theorem that time periodic dissipative systems imply the existence of harmonic periodic solutions, in the case of uniqueness. We will also show that, in the lack of uniqueness, the existence of harmonics is implied by uniform dissipativity. The localization of starting points and multiplicity of periodic solutions will be established, under suitable additional assumptions, as well. The arguments are based on the application of various asymptotic fixed point theorems of the Lefschetz and Nielsen type.
77 FR 73452 - Grace Period Study
2012-12-10
... survey may be distributed in waves for convenience. The Grace Period Study survey will be an electronic... information that is used for sampling purposes will be maintained in a separate file from the quantitative...
Time-Varying Periodicity in Intraday Volatility
DEFF Research Database (Denmark)
Andersen, Torben Gustav; Thyrsgaard, Martin; Todorov, Viktor
We develop a nonparametric test for deciding whether return volatility exhibits time-varying intraday periodicity using a long time-series of high-frequency data. Our null hypothesis, commonly adopted in work on volatility modeling, is that volatility follows a stationary process combined...... with a constant time-of-day periodic component. We first construct time-of-day volatility estimates and studentize the high-frequency returns with these periodic components. If the intraday volatility periodicity is invariant over time, then the distribution of the studentized returns should be identical across...... with estimating volatility moments through their sample counterparts. Critical values are computed via easy-to-implement simulation. In an empirical application to S&P 500 index returns, we find strong evidence for variation in the intraday volatility pattern driven in part by the current level of volatility...
Multi-Period Trading via Convex Optimization
DEFF Research Database (Denmark)
Boyd, Stephen; Busseti, Enzo; Diamond, Steve
2017-01-01
We consider a basic model of multi-period trading, which can be used to evaluate the performance of a trading strategy. We describe a framework for single-period optimization, where the trades in each period are found by solving a convex optimization problem that trades oﬀ expected return, risk......, transaction cost and holding cost such as the borrowing cost for shorting assets. We then describe a multi-period version of the trading method, where optimization is used to plan a sequence of trades, with only the ﬁrst one executed, using estimates of future quantities that are unknown when the trades....... In this paper, we do not address a critical component in a trading algorithm, the predictions or forecasts of future quantities. The methods we describe in this paper can be thought of as good ways to exploit predictions, no matter how they are made. We have also developed a companion open-source software...
Optimization on replacement period of plant equipment
International Nuclear Information System (INIS)
Kasai, Masao; Asano, Hiromi
2002-01-01
Optimization of the replacement period of plant equipment is one of the main items to rationalize the activities on plant maintenance. There are several models to replace the equipment and the formulations for optimizing the replacement period are different among these models. In this study, we calculated the optimum replacement periods for some equipment parts based on the replacement models and found that the optimum solutions are not so largely differ from the replacement models as far as the replacement period is not so large. So we will be able to use the most usable model especially in the early phase of rationalization on plant maintenance, since there are large uncertainties in data for optimization. (author)
Early and Periodic Screening, Diagnosis and Treatment
U.S. Department of Health & Human Services — The Early and Periodic Screening, Diagnostic and Treatment (EPSDT) benefit provides comprehensive and preventive health care services for children under age 21 who...
12 CFR 219.24 - Retention period.
2010-01-01
... PROVIDING FINANCIAL RECORDS; RECORDKEEPING REQUIREMENTS FOR CERTAIN FINANCIAL RECORDS (REGULATION S... period of time, taking into consideration the nature of the record and the amount of time that has...
The period-luminosity relation for Cepheids
International Nuclear Information System (INIS)
Brodie, J.P.
1980-01-01
Numerical simulations of the empirical determination of the period-luminosity-colour relation for classical Cepheids are presented. In this study the quantitative effects of random errors, reddening, sample size and the presence of both colour and period cut-offs (imposed by the finite extent of the instability strip) on the observational redetermination of the original relation are evaluated. Both random errors in the photometry and correlated errors in the reddening corrections are shown to have systematic effects. Especially sensitive to these errors is the colour coefficient in the period-luminosity-colour relation, where the ratio of the error to the width of the instability strip is the determining factor. With present observations only broad confidence limits can be placed on present knowledge of the intrinsic period-luminosity-colour relation and/or its variations from galaxy to galaxy. (author)
Genetics Home Reference: hypokalemic periodic paralysis
... M, Franques J, Bendahhou S, Lory P, Hainque B, Fournier E, Nicole S, Fontaine B. Hypokalemic Periodic Paralysis. 2002 ... related congenital muscular dystrophy Melorheostosis Rhabdoid tumor predisposition syndrome All New & Updated Pages Reviewed : October 2017 Published : ...
The ACM Periodical Bank: A Retrospective View.
Clarke, Jack A.
1980-01-01
Evaluates a cooperative venture in interlibrary lending of periodicals planned and executed by ten midwestern colleges. The study traces the consortium's history from 1967 to the present, describing successes and problems. (RAA)
Concurrent hypokalemic periodic paralysis and bipolar disorder
Directory of Open Access Journals (Sweden)
Chia-Lin Lin
2015-01-01
Full Text Available Primary periodic paralysis is a rare autosomal dominant disorder of ion-channel dysfunction, manifested by episodic flaccid paresis secondary to abnormal sarcolemma excitability. Membrane destabilization involving Na, K-ATPase has been hypothesized to be a biological etiology of the bipolar disorder (BD and the mechanisms underlying lithium therapy have been linked to it. To date, there has been only one reported case of BD comorbid with periodic paralysis. Herein, we reported another case of concurrent bipolar mania and hypokalemic periodic paralysis (HPP, one special form of periodic paralysis. Consistent with the previous case, our patient responded well to lithium treatment for both bipolar mania and HPP. This might provide some support to the hypothesis that the therapeutic effects of lithium in both BD and HPP could be due to the correction of the underlying common pathophysiology.
Ecological periodic tables: In principle and practice
The chemical periodic table, the Linnaean system of classification and the Hertzsprung-Russell diagram are iconic information organizing structure in chemistry, biology and astronomy, respectively, because they are simple, exceptionally useful and they foster the expansion of sci...
Galactic Dark Matter and Terrestrial Periodicities
National Research Council Canada - National Science Library
Clube, S
1998-01-01
.... The Earth may thus be regarded as a probe of the disc environment; and to account for the periodicity, the Galactic disc is required to have a substantial dark matter component ( approx .15 molar mass/cu pc...
Global bioevents and the question of periodicity
Sepkoski, J. John
The hypothesis of periodicity in extinction is an empirical claim that extinction events, while variable in magnitude, are regular in timing and therefore are serially dependent upon some single, ultimate cause with clocklike behavior. This hypothesis is controversal, in part because of questions regarding the identity and timing of certain extinction events and because of speculations concerning possible catastrophic extraterrestrial forcing mechanisms. New data on extinctions of marine animal genera are presented that display a high degree of periodicity in the Mesozoic and Cenozoic as well as a suggestion of nonstationary periodicity in the late Paleozoic. However, no periodicity is evident among the as yet poorly documented extinction events of the early and middle Paleozoic.
Periodical test program in depth revision
International Nuclear Information System (INIS)
Feltin, C.; Zermizoglou, R.
1987-11-01
Inspection visits made to different sites during 1980 and 1981 evidenced the need to extend and define more precisely the periodical tests performed on safety related systems; thus Electricite de France was requested by the Safety Authorities to re-examine the periodical test program for all safety related systems. This paper presents the methodology adopted by Electricite de France in order to perform an exhaustive analysis of the periodical test program for the 900 and 1300 MWe plants, and the organization set up at the IPSN at one hand and Electricite de France on the other hand for the purpose of elaborating a periodical test program which would be ratified by the Safety Authorities
Toward an Organic Chemist's Periodic Table.
Hall, H. K., Jr.
1980-01-01
An analogy between electron transfer reactions of the elements and those of organic molecules is offered. Examples of organic electron transfer reactions are presented. The rationale of constructing an organic chemists' periodic table is also discussed. (HM)
Theodore William Richards and the Periodic Table
Conant, James B.
1970-01-01
Discusses the contribution of Theodore Richards to the accurate determination of atomic weights of copper and other elements; his major contribution was to the building of the definitive periodic table of the elements. (BR)
Spectral properties of almost-periodic Hamiltonians
International Nuclear Information System (INIS)
Lima, R.
1983-12-01
We give a description of some spectral properties of almost-periodic hamiltonians. We put the stress on some particular points of the proofs of the existence of absolutely continuous or pure point spectrum [fr
Astrobee Periodic Technical Review (PTR) Delta 3
Provencher, Christopher; Smith, Marion F.; Smith, Ernest Everett; Bualat, Maria Gabriele; Barlow, Jonathan Spencer
2017-01-01
Astrobee is a free flying robot for the inside of the International Space Station (ISS). The Periodic Technical Review (PTR) delta 3 is the final design review of the system presented to stakeholders.
Periodic words connected with the Fibonacci words
Directory of Open Access Journals (Sweden)
G. M. Barabash
2016-06-01
Full Text Available In this paper we introduce two families of periodic words (FLP-words of type 1 and FLP-words of type 2 that are connected with the Fibonacci words and investigated their properties.
Broiler adaptation to post-hatching period
Directory of Open Access Journals (Sweden)
Maiorka Alex
2006-01-01
Full Text Available In the latest years more attention has been given to mechanisms for bird adaptation at post-hatching period by management of environmental conditions and formulations of diets offered during this period when digestive, immune, and thermo-regulating systems suffer slight changes. In post-hatching period, digestive system is anatomically complete, but its functionality is still immature in relation to adult birds. The chick immunity depends on maternal antibodies transferred to egg just before laying. In addition, variations within thermal comfort zone might affect initial development of chick. For example, high temperatures may induce hyperthermia with dehydration, while low temperatures may lead to hypothermia responsible by pulmonary hypertension syndrome. In conclusion, productivity might be enhanced when good conditions are offered to chicks during the period from last embryo development to first days after hatching.
Prognosis following cancer surgery during holiday periods.
Lagergren, Jesper; Mattsson, Fredrik; Lagergren, Pernilla
2017-11-15
Surgery is the mainstay curative treatment in most cancer. We aimed to test the new hypothesis that cancer surgery performed during holiday periods is associated with worse long-term prognosis than for non-holiday periods. This nationwide Swedish population-based cohort study included 228,927 patients during 1997-2014 who underwent elective resectional surgery for a cancer where the annual number of resections was over 100. The 16 eligible cancer sites were grouped into 10 cancer groups. The exposure, holiday periods, was classified as wide (14-weeks) or narrow (7-weeks). Surgery conducted inside versus outside holiday periods was compared regarding overall disease-specific (main outcome) and overall all-cause (secondary outcome) mortality. Cox regression provided hazard ratios (HR) with 95% confidence intervals (CI) adjusted for age, sex, comorbidity, hospital volume, calendar period and tumor stage. Surgery conducted during wide and narrow holiday periods were associated with increased HRs of disease-specific mortality for cancer of the breast (HR 1.08, 95% CI 1.03-1.13 and HR 1.06, 95% CI 1.01-1.12) and possibly of cancer of the liver-pancreas-bile ducts (HR 1.09, 95% CI 0.99-1.20 and HR 1.12, 95% CI 0.99-1.26). Sub-groups with cancer of the colon-rectum, head-and-neck, prostate, kidney-urine bladder and thyroid also experienced statistically significantly worse prognosis following surgery conducted during holiday periods. No influence of surgery during holiday was detected for cancer of the esophagus-stomach, lung or ovary-uterus. All-cause HRs were similar to the disease-specific HRs. The prognosis following cancer surgery might not be fully maintained during holiday periods for all cancer sites. © 2017 UICC.
Entanglement of periodic anisotropic XY chains
International Nuclear Information System (INIS)
Zhang Lifa; Tong Peiqing
2005-01-01
By using the concept of concurrence, the entanglement of periodic anisotropic XY chains in a transverse field is studied numerically. It is found that the derivatives ∂ λ C(1) of nearest-neighbour concurrence diverge at quantum critical points. By proper scaling, we found that all the derivatives ∂ λ C(1) for periodic XY chains in the vicinity of quantum critical points have the same behaviours as that of a uniform chain
Coupled mode theory of periodic waveguides arrays
DEFF Research Database (Denmark)
Lavrinenko, Andrei; Chigrin, Dmitry N.
We apply the scalar coupled mode theory to the case of waveguides array consisting om two periodic waveguides. One of the waveguides is arbitrary shifted along another. A longitudinal shift acts as a parameter in the coupled mode theory. The proposed theory explains peculiarities of modes dispers...... dispersion and transmission in coupled periodic waveguides systems. Analytical results are compared with the numerical ones obtained by the plane wave expansion and FDTD methods....
IUPAC Periodic Table of the Isotopes
Holden, N.E.; Coplen, T.B.; Böhlke, J.K.; Wieser, M.E.; Singleton, G.; Walczyk, T.; Yoneda, S.; Mahaffy, P.G.; Tarbox, L.V.
2011-01-01
For almost 150 years, the Periodic Table of the Elements has served as a guide to the world of elements by highlighting similarities and differences in atomic structure and chemical properties. To introduce students, teachers, and society to the existence and importance of isotopes of the chemical elements, an IUPAC Periodic Table of the Isotopes (IPTI) has been prepared and can be found as a supplement to this issue.
Periodicity and Immortality in Reversible Computing
Kari , Jarkko; Ollinger , Nicolas
2008-01-01
Additional material available on the web at http://www.lif.univ-mrs.fr/~nollinge/rec/gnirut/; We investigate the decidability of the periodicity and the immortality problems in three models of reversible computation: reversible counter machines, reversible Turing machines and reversible one-dimensional cellular automata. Immortality and periodicity are properties that describe the behavior of the model starting from arbitrary initial configurations: immortality is the property of having at le...
PERIODIC SIGNALS IN BINARY MICROLENSING EVENTS
International Nuclear Information System (INIS)
Guo, Xinyi; Stefano, Rosanne Di; Esin, Ann; Taylor, Jeffrey
2015-01-01
Gravitational microlensing events are powerful tools for the study of stellar populations. In particular, they can be used to discover and study a variety of binary systems. A large number of binary lenses have already been found through microlensing surveys and a few of these systems show strong evidence of orbital motion on the timescale of the lensing event. We expect that more binary lenses of this kind will be detected in the future. For binaries whose orbital period is comparable to the event duration, the orbital motion can cause the lensing signal to deviate drastically from that of a static binary lens. The most striking property of such light curves is the presence of quasi-periodic features, which are produced as the source traverses the same regions in the rotating lens plane. These repeating features contain information about the orbital period of the lens. If this period can be extracted, then much can be learned about the lensing system even without performing time-consuming, detailed light-curve modeling. However, the relative transverse motion between the source and the lens significantly complicates the problem of period extraction. To resolve this difficulty, we present a modification of the standard Lomb–Scargle periodogram analysis. We test our method for four representative binary lens systems and demonstrate its efficiency in correctly extracting binary orbital periods
Interference pattern period measurement at picometer level
Xiang, Xiansong; Wei, Chunlong; Jia, Wei; Zhou, Changhe; Li, Minkang; Lu, Yancong
2016-10-01
To produce large scale gratings by Scanning Beam Interference Lithography (SBIL), a light spot containing grating pattern is generated by two beams interfering, and a scanning stage is used to drive the substrate moving under the light spot. In order to locate the stage at the proper exposure positions, the period of the Interference pattern must be measured accurately. We developed a set of process to obtain the period value of two interfering beams at picometer level. The process includes data acquisition and data analysis. The data is received from a photodiode and a laser interferometer with sub-nanometer resolution. Data analysis differs from conventional analyzing methods like counting wave peaks or using Fourier transform to get the signal period, after a preprocess of filtering and envelope removing, the mean square error is calculated between the received signal and ideal sinusoid waves to find the best-fit frequency, thus an accuracy period value is acquired, this method has a low sensitivity to amplitude noise and a high resolution of frequency. With 405nm laser beams interfering, a pattern period value around 562nm is acquired by employing this process, fitting diagram of the result shows the accuracy of the period value reaches picometer level, which is much higher than the results of conventional methods.
Physical explanation of the periodic table.
Ostrovsky, V N
2003-05-01
The Periodic Table of the elements, the most important generalization in chemistry, is often considered as a representative special case in the study of the relation between chemistry and physics. Its quantum interpretation was initiated, but not completed, by Niels Bohr. In this paper, post-Bohr conceptual developments are discussed from historical and epistemological points of view. The difference between high-precision numerical calculations for individual atoms and the theory of the periodic system as a whole is emphasized. Periodic laws met in Nature are not restricted to the chemical Periodic Table. A comparative study of these laws makes it possible to single out essential features that define the particular pattern of periodicity. It is shown that the periodic system of neutral ground state atoms now has a firm nonempirical quantum-theoretical basis. Alternative approaches, based on group theory and other mathematical schemes, are briefly discussed. It is argued that, while quantum theory is capable of fully accurate calculations for relatively simple atoms or molecular objects, the complexity of polyatomic molecules and chemical reactions guarantees the flourishing of chemistry as a separate scientific discipline.
Estimates on the minimal period for periodic solutions of nonlinear second order Hamiltonian systems
International Nuclear Information System (INIS)
Yiming Long.
1994-11-01
In this paper, we prove a sharper estimate on the minimal period for periodic solutions of autonomous second order Hamiltonian systems under precisely Rabinowitz' superquadratic condition. (author). 20 refs, 1 fig
Bounded and Periodic Solutions of Semilinear Impulsive Periodic System on Banach Spaces
Directory of Open Access Journals (Sweden)
Wei W
2008-01-01
Full Text Available Abstract A class of semilinear impulsive periodic system on Banach spaces is considered. First, we introduce the -periodic PC-mild solution of semilinear impulsive periodic system. By virtue of Gronwall lemma with impulse, the estimate on the PC-mild solutions is derived. The continuity and compactness of the new constructed Poincaré operator determined by impulsive evolution operator corresponding to homogenous linear impulsive periodic system are shown. This allows us to apply Horn's fixed-point theorem to prove the existence of -periodic PC-mild solutions when PC-mild solutions are ultimate bounded. This extends the study on periodic solutions of periodic system without impulse to periodic system with impulse on general Banach spaces. At last, an example is given for demonstration.
Lusine Poghosyan
2014-01-01
The paper considers convergence acceleration of the quasi-periodic and the quasi-periodic-rational interpolations by application of polynomial corrections. We investigate convergence of the resultant quasi-periodic-polynomial and quasi-periodic-rational-polynomial interpolations and derive exact constants of the main terms of asymptotic errors in the regions away from the endpoints. Results of numerical experiments clarify behavior of the corresponding interpolations for moderate number of in...
Sevcik, Richard S.; McGinty, Ragan L.; Schultz, Linda D.; Alexander, Susan V.
2008-01-01
Periodic Table Target, a game for middle school or high school students, familiarizes students with the form of the periodic table and the biological significance of different elements. The Periodic Table Target game board is constructed as a class project, and the game is played to reinforce the content. Students are assigned several elements…
Smith, Dan
2014-01-01
What is a sense of period? And how can pupils' sense of period be developed? Questions such as these have troubled history teachers for many years, often revolving around debates over the role played by empathy and imagination in coming to know a period on its own terms. Rather than adopt a comparative approach, Dan Smiths decided in his teaching…
Charged particle periodicity in the Saturnian magnetosphere
International Nuclear Information System (INIS)
Carbary, J.F.; Krimigis, S.M.
1982-01-01
The low energy charged particles (LECP) experiments on the Voyager 1 and 2 spacecraft performed measurements of electrons (approx.22 keV to approx.20 MeV) and ions (approx.28 keV to approx.150 MeV) during the Saturn encounters in 1980 and 1981. Count rate ratios of two of the low energy electron (22 to 35 keV and 183 to 500 keV) and ion (43 to 80 keV and 137 to 215 keV) channels exhibit an approximation 10 hour periodicity in the outer Saturnian magnetosphere beyond the orbit of Titan. Electron ratios vary from approx.50 to approx.300; ion ratios vary from approx.3 to approx.20. Similar but less pronounced periodicities are observed for higher and lower energy electron and ion spectral indices. Three complete cycles were observed during the Voyager 2 outbound portion of the encounter from which were determined an electron ratio period of 10/sup h/21/sup m/ +- 48/sup m/ and an ion ratio period of 9/sup h/49/sup m/ +- 59/sup m/. Using Saturn Kilometric Radiation (SKR) and Saturn Electrostatic Discharge (SED) periods, extrapolation backward from Voyager 2 to Voyager 1 suggests that the periodicities are Saturnian rather than Jovian in nature, and that they persist in phase for time intervals at least as long as 287 days. Ratio minima, or spectral hardenings, occur in the same hemisphere as do auroral brightenings, SKR activity, and spoke enhanement. We interpret the observations as prima facie evidence of an asymmetry in the Saturian magnetic field and the root cause of the observed SKR periodicity
Periodic subsystem density-functional theory
International Nuclear Information System (INIS)
Genova, Alessandro; Pavanello, Michele; Ceresoli, Davide
2014-01-01
By partitioning the electron density into subsystem contributions, the Frozen Density Embedding (FDE) formulation of subsystem Density Functional Theory (DFT) has recently emerged as a powerful tool for reducing the computational scaling of Kohn–Sham DFT. To date, however, FDE has been employed to molecular systems only. Periodic systems, such as metals, semiconductors, and other crystalline solids have been outside the applicability of FDE, mostly because of the lack of a periodic FDE implementation. To fill this gap, in this work we aim at extending FDE to treat subsystems of molecular and periodic character. This goal is achieved by a dual approach. On one side, the development of a theoretical framework for periodic subsystem DFT. On the other, the realization of the method into a parallel computer code. We find that periodic FDE is capable of reproducing total electron densities and (to a lesser extent) also interaction energies of molecular systems weakly interacting with metallic surfaces. In the pilot calculations considered, we find that FDE fails in those cases where there is appreciable density overlap between the subsystems. Conversely, we find FDE to be in semiquantitative agreement with Kohn–Sham DFT when the inter-subsystem density overlap is low. We also conclude that to make FDE a suitable method for describing molecular adsorption at surfaces, kinetic energy density functionals that go beyond the GGA level must be employed
Periodic subsystem density-functional theory
Genova, Alessandro; Ceresoli, Davide; Pavanello, Michele
2014-11-01
By partitioning the electron density into subsystem contributions, the Frozen Density Embedding (FDE) formulation of subsystem Density Functional Theory (DFT) has recently emerged as a powerful tool for reducing the computational scaling of Kohn-Sham DFT. To date, however, FDE has been employed to molecular systems only. Periodic systems, such as metals, semiconductors, and other crystalline solids have been outside the applicability of FDE, mostly because of the lack of a periodic FDE implementation. To fill this gap, in this work we aim at extending FDE to treat subsystems of molecular and periodic character. This goal is achieved by a dual approach. On one side, the development of a theoretical framework for periodic subsystem DFT. On the other, the realization of the method into a parallel computer code. We find that periodic FDE is capable of reproducing total electron densities and (to a lesser extent) also interaction energies of molecular systems weakly interacting with metallic surfaces. In the pilot calculations considered, we find that FDE fails in those cases where there is appreciable density overlap between the subsystems. Conversely, we find FDE to be in semiquantitative agreement with Kohn-Sham DFT when the inter-subsystem density overlap is low. We also conclude that to make FDE a suitable method for describing molecular adsorption at surfaces, kinetic energy density functionals that go beyond the GGA level must be employed.
Multiphase averaging of periodic soliton equations
International Nuclear Information System (INIS)
Forest, M.G.
1979-01-01
The multiphase averaging of periodic soliton equations is considered. Particular attention is given to the periodic sine-Gordon and Korteweg-deVries (KdV) equations. The periodic sine-Gordon equation and its associated inverse spectral theory are analyzed, including a discussion of the spectral representations of exact, N-phase sine-Gordon solutions. The emphasis is on physical characteristics of the periodic waves, with a motivation from the well-known whole-line solitons. A canonical Hamiltonian approach for the modulational theory of N-phase waves is prescribed. A concrete illustration of this averaging method is provided with the periodic sine-Gordon equation; explicit averaging results are given only for the N = 1 case, laying a foundation for a more thorough treatment of the general N-phase problem. For the KdV equation, very general results are given for multiphase averaging of the N-phase waves. The single-phase results of Whitham are extended to general N phases, and more importantly, an invariant representation in terms of Abelian differentials on a Riemann surface is provided. Several consequences of this invariant representation are deduced, including strong evidence for the Hamiltonian structure of N-phase modulational equations
Medicine in Balkans during the Roman Period.
Baykan, Daniş
2017-08-04
The aim of this study is to investigate the archaeological finds to enlighten the medical methods of treatments and operations applied in Balkans during Roman Period. Some independent local and regional find groups, taken from existing publications will be grouped together and a holistic point-of-view will be taken against medicine in Balkan Geography during Roman Period. Due to basic differences it contained, the data before Roman Period are excluded. Most of Greece and Aegean Islands are also excluded since the topic selected is "Medicine of Roman Period." Greece and Aegean Islands should be evaluated in another study in connection with West Anatolia which is closer than the Balkan Geography in terms of social relations. The spread of medical tools in Balkans during Roman Period is concentrated around military garrisons, and in settlements built around military pathways, and in settlements containing an amphitheater associated with gladiators. This spread is verified by the studies on Bulgaria in general. The data is also compatible with the assertion suggesting that the amount of application of pharmaceutical treatment increases when one moves away from the military centres.
The Discrete Beverton-Holt Model with Periodic Harvesting in a Periodically Fluctuating Environment
Directory of Open Access Journals (Sweden)
Ziyad AlSharawi
2010-01-01
Full Text Available We investigate the effect of constant and periodic harvesting on the Beverton-Holt model in a periodically fluctuating environment. We show that in a periodically fluctuating environment, periodic harvesting gives a better maximum sustainable yield compared to constant harvesting. However, if one can also fix the environment, then constant harvesting in a constant environment can be a better option, especially for sufficiently large initial populations. Also, we investigate the combinatorial structure of the periodic sequence of carrying capacities and its effect on the maximum sustainable yield. Finally, we leave some questions worth further investigations.
International Nuclear Information System (INIS)
Guo, Yu; Luo, Albert C.J.
2015-01-01
In this paper, analytically predicted are complex periodic motions in the periodically forced, damped, hardening Duffing oscillator through discrete implicit maps of the corresponding differential equations. Bifurcation trees of periodic motions to chaos in such a hardening Duffing oscillator are obtained. The stability and bifurcation analysis of periodic motion in the bifurcation trees is carried out by eigenvalue analysis. The solutions of all discrete nodes of periodic motions are computed by the mapping structures of discrete implicit mapping. The frequency-amplitude characteristics of periodic motions are computed that are based on the discrete Fourier series. Thus, the bifurcation trees of periodic motions are also presented through frequency-amplitude curves. Finally, based on the analytical predictions, the initial conditions of periodic motions are selected, and numerical simulations of periodic motions are carried out for comparison of numerical and analytical predictions. The harmonic amplitude spectrums are also given for the approximate analytical expressions of periodic motions, which can also be used for comparison with experimental measurement. This study will give a better understanding of complex periodic motions in the hardening Duffing oscillator.
Policy Uncertainty, Investment and Commitment Periods
Energy Technology Data Exchange (ETDEWEB)
NONE
2007-07-01
Today's investment decisions in key sectors such as energy, forestry or transport have significant impacts on the levels of greenhouse gas (GHG) emissions over the coming decades. Given the economic and environmental long-term implications of capital investment and retirement, a climate mitigation regime should aim to encourage capital investment in climate-friendly technologies. Many factors affect technology choice and the timing of investment, including investor expectations about future prices and policies. Recent international discussions have focused on the importance of providing more certainty about future climate policy stringency. The design of commitment periods can play a role in creating this environment. This paper assesses how the length of commitment periods influences policy uncertainty and investment decisions. In particular, the paper analyses the relationship between commitment period length and near term investment decisions in climate friendly technology.
Magnetomechanically induced long period fiber gratings
International Nuclear Information System (INIS)
Causado-Buelvas, Jesus D.; Gomez-Cardona, Nelson D.; Torres, Pedro
2008-01-01
In this work, we report a simple, flexible method to create long period fiber gratings mechanically by controlling the repulsion/attraction force between two magnets that pressing a plate with a periodic array of small glass cylinders to a short length of optical fiber. Via the photoelastic effect, the pressure points induce the required periodic refractive index modulation to create the LPFG. We found that the induced device exhibits spectral characteristics similar to those of other types of LPFG. As the optical properties of LPFGs are directly related to the nature of the applied perturbations, we show, to our knowledge for the frrst time, how is the evolution of birefringence effects in mechanically induced LPFGs
Effective propagation in a perturbed periodic structure
Maurel, Agnès; Pagneux, Vincent
2008-08-01
In a recent paper [D. Torrent, A. Hakansson, F. Cervera, and J. Sánchez-Dehesa, Phys. Rev. Lett. 96, 204302 (2006)] inspected the effective parameters of a cluster containing an ensemble of scatterers with a periodic or a weakly disordered arrangement. A small amount of disorder is shown to have a small influence on the characteristics of the acoustic wave propagation with respect to the periodic case. In this Brief Report, we inspect further the effect of a deviation in the scatterer distribution from the periodic distribution. The quasicrystalline approximation is shown to be an efficient tool to quantify this effect. An analytical formula for the effective wave number is obtained in one-dimensional acoustic medium and is compared with the Berryman result in the low-frequency limit. Direct numerical calculations show a good agreement with the analytical predictions.
Effective propagation in a perturbed periodic structure
International Nuclear Information System (INIS)
Maurel, Agnes; Pagneux, Vincent
2008-01-01
In a recent paper [D. Torrent, A. Hakansson, F. Cervera, and J. Sanchez-Dehesa, Phys. Rev. Lett. 96, 204302 (2006)] inspected the effective parameters of a cluster containing an ensemble of scatterers with a periodic or a weakly disordered arrangement. A small amount of disorder is shown to have a small influence on the characteristics of the acoustic wave propagation with respect to the periodic case. In this Brief Report, we inspect further the effect of a deviation in the scatterer distribution from the periodic distribution. The quasicrystalline approximation is shown to be an efficient tool to quantify this effect. An analytical formula for the effective wave number is obtained in one-dimensional acoustic medium and is compared with the Berryman result in the low-frequency limit. Direct numerical calculations show a good agreement with the analytical predictions
Krsko NPP Periodic Safety Review program
International Nuclear Information System (INIS)
Basic, I.; Spiler, J.; Novsak, M.
2001-01-01
The need for conducting a Periodic Safety Review for the Krsko NPP has been clearly recognized both by the NEK and the regulator (SNSA). The PSR would be highly desirable both in the light of current trends in safety oversight practices and because of many benefits it is capable to provide. On January 11, 2001 the SNSA issued a decision requesting the Krsko NPP to prepare a program and determine a schedule for the implementation of the program for 'Periodic Safety Review of NPP Krsko'. The program, which is required to be in accordance with the IAEA safety philosophy and with the EU practice, was submitted for the approval to the SNSA by the end of March 2001. The paper summarizes Krsko NPP Periodic Safety Review Program [1] including implemented SNSA and IAEA Expert Mission comments.(author)
Electromagnetic Radiation of Electrons in Periodic Structures
Potylitsyn, Alexander Petrovich
2011-01-01
Periodic magnetic structures (undulators) are widely used in accelerators to generate monochromatic undulator radiation (UR) in the range from far infrared to the hard X-ray region. Another periodic crystalline structure is used to produce quasimonochromatic polarized photon beams via the coherent bremsstrahlung mechanism (CBS). Due to such characteristics as monochromaticity, polarization and adjustability, these types of radiation is of large interest for applied and basic research of accelerator-emitted radiation. The book provides a detailed overview of the fundamental principles behind electromagnetic radiation emitted from accelerated charged particles (e.g. UR, CBS, radiation of fast electrons in Laser flash fields) as well as a unified description of relatively new radiation mechanisms which attracted great interest in recent years. This are the so-called polarization radiation excited by the Coulomb field of incident particles in periodic structures, parametric X-rays, resonant transition radiation a...
Subdomain Precise Integration Method for Periodic Structures
Directory of Open Access Journals (Sweden)
F. Wu
2014-01-01
Full Text Available A subdomain precise integration method is developed for the dynamical responses of periodic structures comprising many identical structural cells. The proposed method is based on the precise integration method, the subdomain scheme, and the repeatability of the periodic structures. In the proposed method, each structural cell is seen as a super element that is solved using the precise integration method, considering the repeatability of the structural cells. The computational efforts and the memory size of the proposed method are reduced, while high computational accuracy is achieved. Therefore, the proposed method is particularly suitable to solve the dynamical responses of periodic structures. Two numerical examples are presented to demonstrate the accuracy and efficiency of the proposed method through comparison with the Newmark and Runge-Kutta methods.
[Hypertension and pregnancy: Post-partum period].
Hugon-Rodin, Justine; Plu-Bureau, Geneviève
2016-01-01
Post-partum period is associated with specific characteristics in women with gestational disorders or preeclampsia. For breastfeeding women, the choice of antihypertensive treatment should take into account the impact on child health. The impact of breastfeeding on health mother must be also discussed. Moreover, for lactation inhibition, bromocriptine should not be used, especially in the context of gestational disorders. In post-partum period, the best contraceptive strategy is only-progestin contraception or non-hormonal contraceptives use. However, this choice will depend on the stabilization or normalization of blood pressure in early post-partum period. Finally, several consultations should be suggested: an information and announcement to explain the consequences of these gestational disorders and organize their multidisciplinary management and follow-up. A preconceptional consultation takes its place to anticipate potential recurrent preeclampsia or gestational hypertension and to schedule a future pregnancy in optimal conditions. Copyright © 2016. Published by Elsevier Masson SAS.
Quasi-periodicity in deep redshift surveys
International Nuclear Information System (INIS)
Weygaert, R. van de
1991-01-01
The recent result by Broadhurst et al., (1990. Nature 343, 726) showing a striking, nearly periodic, galaxy redshift distribution in a narrow pencil-beam survey, is explained within the Voronoi cellular model of clustering of galaxies. Galaxies, whose luminosities are selected from a Schechter luminosity function, are placed randomly within the walls of this cellular model. Narrow and deep, magnitude-limited, pencil-beam surveys through these structures are simulated. Some 15 per cent of these beams show that observed regular pattern, with a spacing between the peaks of the order of 105 h -1 -150 h -1 Mpc, but most pencil-beams show peaks in the redshift distribution without periodicity, so we may conclude that, even within a cellular universe, periodicity is not a common phenomenon. (author)
Vlasov dynamics of periodically driven systems
Banerjee, Soumyadip; Shah, Kushal
2018-04-01
Analytical solutions of the Vlasov equation for periodically driven systems are of importance in several areas of plasma physics and dynamical systems and are usually approximated using ponderomotive theory. In this paper, we derive the plasma distribution function predicted by ponderomotive theory using Hamiltonian averaging theory and compare it with solutions obtained by the method of characteristics. Our results show that though ponderomotive theory is relatively much easier to use, its predictions are very restrictive and are likely to be very different from the actual distribution function of the system. We also analyse all possible initial conditions which lead to periodic solutions of the Vlasov equation for periodically driven systems and conjecture that the irreducible polynomial corresponding to the initial condition must only have squares of the spatial and momentum coordinate. The resulting distribution function for other initial conditions is aperiodic and can lead to complex relaxation processes within the plasma.
Periodic safety analyses; Les essais periodiques
Energy Technology Data Exchange (ETDEWEB)
Gouffon, A; Zermizoglou, R
1990-12-01
The IAEA Safety Guide 50-SG-S8 devoted to 'Safety Aspects of Foundations of Nuclear Power Plants' indicates that operator of a NPP should establish a program for inspection of safe operation during construction, start-up and service life of the plant for obtaining data needed for estimating the life time of structures and components. At the same time the program should ensure that the safety margins are appropriate. Periodic safety analysis are an important part of the safety inspection program. Periodic safety reports is a method for testing the whole system or a part of the safety system following the precise criteria. Periodic safety analyses are not meant for qualification of the plant components. Separate analyses are devoted to: start-up, qualification of components and materials, and aging. All these analyses are described in this presentation. The last chapter describes the experience obtained for PWR-900 and PWR-1300 units from 1986-1989.
Periodic solutions of Volterra integral equations
Directory of Open Access Journals (Sweden)
M. N. Islam
1988-01-01
Full Text Available Consider the system of equationsx(t=f(t+∫−∞tk(t,sx(sds, (1andx(t=f(t+∫−∞tk(t,sg(s,x(sds. (2Existence of continuous periodic solutions of (1 is shown using the resolvent function of the kernel k. Some important properties of the resolvent function including its uniqueness are obtained in the process. In obtaining periodic solutions of (1 it is necessary that the resolvent of k is integrable in some sense. For a scalar convolution kernel k some explicit conditions are derived to determine whether or not the resolvent of k is integrable. Finally, the existence and uniqueness of continuous periodic solutions of (1 and (2 are btained using the contraction mapping principle as the basic tool.
Impact of the infectious period on epidemics
Wilkinson, Robert R.; Sharkey, Kieran J.
2018-05-01
The duration of the infectious period is a crucial determinant of the ability of an infectious disease to spread. We consider an epidemic model that is network based and non-Markovian, containing classic Kermack-McKendrick, pairwise, message passing, and spatial models as special cases. For this model, we prove a monotonic relationship between the variability of the infectious period (with fixed mean) and the probability that the infection will reach any given subset of the population by any given time. For certain families of distributions, this result implies that epidemic severity is decreasing with respect to the variance of the infectious period. The striking importance of this relationship is demonstrated numerically. We then prove, with a fixed basic reproductive ratio (R0), a monotonic relationship between the variability of the posterior transmission probability (which is a function of the infectious period) and the probability that the infection will reach any given subset of the population by any given time. Thus again, even when R0 is fixed, variability of the infectious period tends to dampen the epidemic. Numerical results illustrate this but indicate the relationship is weaker. We then show how our results apply to message passing, pairwise, and Kermack-McKendrick epidemic models, even when they are not exactly consistent with the stochastic dynamics. For Poissonian contact processes, and arbitrarily distributed infectious periods, we demonstrate how systems of delay differential equations and ordinary differential equations can provide upper and lower bounds, respectively, for the probability that any given individual has been infected by any given time.
Ma. de Lourdes Romero Álvarez
2002-01-01
En este artículo se plantea una de las cuestiones fundamentales sobre las que se realiza la actividad periodística y que la autora ha llamado el pacto periodístico. El pacto, celebrado entre el periodista y sus lectores, consiste en que el emisor expresa lo que sucedió tal y como lo vio y el destinatario acepta lo expresado en las mismas condiciones. El compromiso entre ambos participantes los obliga a saber y cumplir con lo estipulado en el contrato, para evitar que alguna de ...
Pulsation properties of Mira long period variables
International Nuclear Information System (INIS)
Cahn, J.H.
1980-01-01
A matter of great interest to variable star students concerns the mode of pulsation of Mira long period variables. In this report we first give observational evidence for the pulsation constant Q. We then compare the observations with calculations. Next, we review two interesting groups of papers dealing with hydrodynamic properties of long period variables. In the first, a fully dynamic nonlinear calculation maps out the Mira instability domain. In the second, special attention is paid to shock propagation beyond the photosphere which in large measure accounts for the complex spectra from this region. (orig./WL)
Short period tidal variations of earth rotation
Yoder, C. F.; Williams, J. G.; Parke, M. E.; Dickey, J. O.
1981-01-01
It is explained that the tidal deformation of the earth's polar moment of inertia by the moon and sun cause periodic variations in rotation. The short period oscillations give rise to a meter-sized, diurnal signature in the lunar laser ranging data obtained at McDonald Observatory. A solution is given for the scale parameter k/C at fortnightly and monthly tidal frequencies. The results are compared with those obtained by other investigators and with a theoretical estimate which includes the effect of oceans and a decoupled fluid core.
Mathematics of Periodic Tables for Benzenoid Hydrocarbons.
Dias, Jerry Ray
2007-01-01
The upper and lower bounds for invariants of polyhex systems based on the Harary and Harborth inequalities are studied. It is shown that these invariants are uniquely correlated by the Periodic Table for Benzenoid Hydrocarbons. A modified periodic table for total resonant sextet (TRS) benzenoids based on the invariants of Ds and r(empty) is presented; Ds is the number of disconnections among the empty rings for fused TRS benzenoid hydrocarbons. This work represents a contribution toward deciphering the topological information content of benzenoid formulas.
Orbital Period Changes in WZ Sagittae
Patterson, Joseph; Stone, Geoffrey; Kemp, Jonathan; Skillman, David R.; de Miguel, Enrique; Potter, Michael; Starkey, Donn; Uthas, Helena; Jones, Jim; Slauson, Douglas; Koff, Robert; Myers, Gordon; Menzies, Kenneth; Campbell, Tut; Roberts, George; Foote, Jerry; Vanmunster, Tonny; Cook, Lewis M.; Krajci, Thomas; Ogmen, Yenal; Sabo, Richard; Seargeant, Jim
2018-06-01
We report a long-term (1961–2017) study of the eclipse times in the dwarf nova WZ Sagittae, in an effort to learn its rate of orbital-period change. Some wiggles with a timescale of 20–50 years are apparent, and a connection with the ∼23 year interval between dwarf-nova eruptions is possible. These back-and-forth wiggles dominate the O–C diagram, and prevent a secure measurement of the steady rate of orbital-period change.
Radiocarbon clock strikes the glacial period pulse
International Nuclear Information System (INIS)
Serebryannyj, L.R.
1976-01-01
Discussed are some aspects of the theory of radiocarbon dating in application to the study of the history of the Earth. The accumulation and the decay of C 14 and methods for its recording are desribed. Presented is a block diagram of a scintillation counter for recording C 14 . The chronology of the last glaciation of Europe has been determined: the Interglacial period (between 50 and 40 thousand years) a prolonged preglacil period (between 40 and 25 thousand years), the last glaciation (between 25 and 10 thousand years ago)
[Hypoglycaemic periodic paralysis in hyperthyroidism patients].
Kratochvíl, J; Masopust, J; Martínková, V; Charvát, J
2008-11-01
Hypokalemic periodic paralysis (HPP) is a rare disorder characterised by acute, potentially fatal atacks of muscle weakness or paralysis. Massive shift of potassium into cells is caused by elevated levels of insulin and catecholamines in the blood. Hypophosphatemia and hypomagnesemia may be also present. Acidobasic status usually is not impaired. HPP occurs as familiar (caused by ion channels inherited defects) or acquired (in patients with hyperthyroidism). On the basis of two clinical cases we present a review of hypokalemic periodic paralysis in hyperthyroid patients. We discuss patogenesis, clinical and laboratory findings as well as the principles of prevention and treatment of this rare disorder.
Using periodicity to mitigate ground vibration
DEFF Research Database (Denmark)
Andersen, Lars Vabbersgaard
2015-01-01
Introduction of trenches, barriers and wave impeding blocks on the transmission path between a source and receiver can be used for mitigation of ground vibration. However, to be effective a barrier must have a depth of about one wavelength of the waves to be mitigated. Hence, while great reductions......: A soil with periodic stiffening (ground improvement) and a ground with periodic changes in the surface elevation obtained by artificial landscaping. By means of a two-dimensional finite-element model, the stiffness and mass matrices are determined for a single cell of the ground with horizonal...
Reconstruction of periodic signals using neural networks
Directory of Open Access Journals (Sweden)
José Danilo Rairán Antolines
2014-01-01
Full Text Available In this paper, we reconstruct a periodic signal by using two neural networks. The first network is trained to approximate the period of a signal, and the second network estimates the corresponding coefficients of the signal's Fourier expansion. The reconstruction strategy consists in minimizing the mean-square error via backpro-pagation algorithms over a single neuron with a sine transfer function. Additionally, this paper presents mathematical proof about the quality of the approximation as well as a first modification of the algorithm, which requires less data to reach the same estimation; thus making the algorithm suitable for real-time implementations.
Periodic Boundary Motion in Thermal Turbulence
International Nuclear Information System (INIS)
Zhang, Jun; Libchaber, Albert
2000-01-01
A free-floating plate is introduced in a Benard convection cell with an open surface. It partially covers the cell and distorts the local heat flux, inducing a coherent flow that in turn moves the plate. Remarkably, the plate can be driven to a periodic motion even under the action of a turbulent fluid. The period of the oscillation depends on the coverage ratio, and on the Rayleigh number of the convective system. The plate oscillatory behavior observed in this experiment may be related to a geological model, in which continents drift in a quasiperiodic fashion. (c) 2000 The American Physical Society
On Helmholtz Problem for Plane Periodical Structures
International Nuclear Information System (INIS)
Akishin, P.G.; Vinitskij, S.I.
1994-01-01
The plane Helmholtz problem of the periodical disc structures with the phase shifts conditions of the solutions along the basis lattice vectors and the Dirichlet conditions on the basic boundaries is considered. The Green function satisfying the quasi periodical conditions on the lattice is constructed. The Helmholtz problem is reduced to the boundary integral equations for the simple layer potentials of this Green function. The methods of the discretization of the arising integral equations are proposed. The procedures of calculation of the matrix elements are discussed. The reality of the spectral parameter of the nonlinear continuous and discretized problems is shown. 8 refs., 2 figs
Magnetic properties of non-interacting Fe-C nanoparticles
DEFF Research Database (Denmark)
Hansen, Mikkel Fougt; Bødker, Franz; Mørup, Steen
1998-01-01
A series of ferrofluids containing 4,7 nm particles of amorphous Fe1-x Cx with an extremely narrow size distribution and a wide range of concentrations has been prepared. A dilute ferrofluid has been studied by electron microscopy, Mossbauer spectroscopy and zero field cooled magnetisation measur...
Non-interactive and Reusable Non-malleable Commitment Schemes
DEFF Research Database (Denmark)
Damgård, Ivan Bjerre; Groth, Jens
2003-01-01
version based on the strong RSA assumption. For UC commitments, we show that existence of a UC commitment scheme in the CRS model (interactive or not) implies key exchange and - for a uniform reference string - even implies oblivious transfer. This indicates that UC commitment is a strictly stronger...... primitive than NM. Finally, we show that our strong RSA based construction can be used to improve the most efficient known UC commitment scheme so it can work with a CRS of size independent of the number of players, without loss of efficiency....
Culture and Cooperation during the Interwar Period
Directory of Open Access Journals (Sweden)
Anişoara Popa
2015-05-01
Full Text Available Starting from the most important Publications of the International Institute for Intellectual Cooperation (1925-1946 we will explore the ideas concerning culture and personalities involved in the intellectual cooperation during the Interwar Period. Pointing out the role that the International Institute of Intellectual Cooperation had and the Romanian contribution to this cooperation is another purpose of this article.
Periodic Solutions for Highly Nonlinear Oscillation Systems
DEFF Research Database (Denmark)
Ghadimi, M; Barari, Amin; Kaliji, H.D
2012-01-01
In this paper, Frequency-Amplitude Formulation is used to analyze the periodic behavior of tapered beam as well as two complex nonlinear systems. Many engineering structures, such as offshore foundations, oil platform supports, tower structures and moving arms, are modeled as tapered beams...
Periodic review in natural resource contracts | Mandelbaum ...
African Journals Online (AJOL)
Periodic contract review mechanisms, which are provisions in contracts that formally require parties to meet at particular intervals to review the terms of the contract, are mechanisms that may facilitate the process of negotiating contractual changes to accommodate changing circumstances over the term of extractive ...
Resonances in a periodically driven bosonic system
Quelle, Anton; Smith, Cristiane Morais
2017-11-01
Periodically driven systems are a common topic in modern physics. In optical lattices specifically, driving is at the origin of many interesting phenomena. However, energy is not conserved in driven systems, and under periodic driving, heating of a system is a real concern. In an effort to better understand this phenomenon, the heating of single-band systems has been studied, with a focus on disorder- and interaction-induced effects, such as many-body localization. Nevertheless, driven systems occur in a much wider context than this, leaving room for further research. Here, we fill this gap by studying a noninteracting model, characterized by discrete, periodically spaced energy levels that are unbounded from above. We couple these energy levels resonantly through a periodic drive, and discuss the heating dynamics of this system as a function of the driving protocol. In this way, we show that a combination of stimulated emission and absorption causes the presence of resonant stable states. This will serve to elucidate the conditions under which resonant driving causes heating in quantum systems.
5 CFR 317.503 - Probationary period.
2010-01-01
.... (b) When a career appointee's executive qualification have been certified by a Qualifications Review... THE SENIOR EXECUTIVE SERVICE Career Appointments § 317.503 Probationary period. (a) An individual's initial appointment as an SES career appointee becomes final only after the individual has served a 1-year...
New Realization of Periodic Cycled Separation
DEFF Research Database (Denmark)
Toftegard, Bjarne; Clausen, Charlotte H.; Jørgensen, Sten B.
2016-01-01
are drained sequentially rather than simultaneously, such that the vapor flow is not interrupted during the liquid drainage. For different ratios of counter-current vapor/liquid flow rates, column efficiencies for periodically cycled columns are shown experimentally to be two times greater than those...
Teaching the Hitler Period: History and Morality.
Mork, Gordon R.
1980-01-01
Outlines six approaches used in a university history course which address the problems of teaching the Hitler period. The assumption underlying all the approaches is that Americans are not entirely different from Germans and that they may be faced with similar moral choices. The approaches avoid the didactic moralism often taught about this era.…
Vitamins and administration periods effects on haematological ...
African Journals Online (AJOL)
Vitamins and administration periods effects on haematological parameters of broiler ... Data obtained on haematological indices were subjected to Analysis of ... été répartis sur base de l'égalisation du poids en neuf (9) groupes de traitement, ...
Regular arrangement of periodates bound to lysozyme
Czech Academy of Sciences Publication Activity Database
Ondráček, Jan; Weiss, M.S.; Brynda, Jiří; Fiala, J.; Jursík, F.; Řezáčová, Pavlína; Jenner, L.B.; Sedláček, Juraj
2005-01-01
Roč. 61, Pt9 (2005), s. 1181-1189 ISSN 0907-4449 Institutional research plan: CEZ:AV0Z50520514 Keywords : hen egg white lysozyme * periodate * epitaxy Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.401, year: 2005
QS Spiral: Visualizing Periodic Quantified Self Data
DEFF Research Database (Denmark)
Larsen, Jakob Eg; Cuttone, Andrea; Jørgensen, Sune Lehmann
2013-01-01
In this paper we propose an interactive visualization technique QS Spiral that aims to capture the periodic properties of quantified self data and let the user explore those recurring patterns. The approach is based on time-series data visualized as a spiral structure. The interactivity includes ...
Gestation period and twinning in chimpanzees.
PEACOCK, L J; ROGERS, C M
1959-04-10
The length of the gestation period in 118 births in a colony of chimpanzees was found to be 226.8 days, with a standard deviation of 13.3 and a range of 196 to 260 days. Six pairs of twins were born in 120 parturitions; thus the apparent twinning rate is higher than that in man.
Theory of periodic conjugate heat transfer
Zudin, Yuri B
2016-01-01
This book presents the theory of periodic conjugate heat transfer in detail. It offers a simplified description of the interaction between a solid body and a fluid as a boundary value problem of the heat conduction equation for the solid body.
Periodic diffeomorphisms on homotopy E (4) surfaces
Indian Academy of Sciences (India)
Home; Journals; Proceedings – Mathematical Sciences; Volume 124; Issue 3. Periodic Diffeomorphisms on Homotopy (4) Surfaces. Hongxia Li. Volume 124 Issue 3 August 2014 pp 437-445. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/pmsc/124/03/0437-0445 ...
Pleural effusions in the postpartum period
International Nuclear Information System (INIS)
Stark, P.; Pollack, M.S.
1986-01-01
We report on the high frequency of pleural effusions in the immediate postpartum period. Forty-four out of 45 women who examined within 24-48 h after delivery showed evidence of pleural fluid. Under these circumstances, this pleural abnormality should not be considered an indicator of serious cardiopulmonary disease. (orig.) [de
U. S. and Canadian Indian Periodicals.
Price, John
The document lists and discusses Indian-published and Indian-oriented newspapers, periodicals, and other assorted publications generally designed to establish a communication system reflecting the interest of the majority of American Indians. Also provided are resumes of several publications that are thought to have gained wide acceptance through…
Periodical Cicada--Brood V (Pest Alert)
USDA Forest Service
1999-01-01
Three separate species of periodical cicadas, Magicicada septendecim (L.), M. cassini (Fisher), and M. septendecula (Alexander and Moore), will appear this spring over large portions of Ohio and West Virginia during the scheduled Brood V emergence. This brood is the largest that occurs in either state and was last seen in 1982. It will also emerge in the southwest...
Engineered quantum tunnelling in extended periodic potentials
Energy Technology Data Exchange (ETDEWEB)
Wimberger, Sandro; Ciampini, Donatella; Morsch, Oliver; Mannella, Riccardo; Arimondo, Ennio [CNR-INFM and Dipartimento di Fisica ' Enrico Fermi' , Largo Pontecorvo 3, 1-56127 Pisa (Italy)
2007-05-15
Quantum tunnelling from a tilted, but otherwise periodic potential is studied. Our theoretical and experimental results show that, by controlling the system's parameters, we can engineer the escape rate of a Bose-Einstein condensate to an exceptional degree. Possible applications of this atom-optics realization of the open Wannier-Stark system are discussed.
Periodic and recurrent variations of cosmic rays
International Nuclear Information System (INIS)
Somogyi, A.J.
1981-12-01
The new results achieved in the field of periodic and recurrent variations of the intensity of 10 9 to 10 13 eV cosmic rays are reviewed. Particular emphasis is given to developments in understanding the fluctuations of corotation-type anisotropies as well as to the structure of the heliosphere and its temporal changes. (author)
42 CFR 423.38 - Enrollment periods.
2010-10-01
... 42 Public Health 3 2010-10-01 2010-10-01 false Enrollment periods. 423.38 Section 423.38 Public... material provision of its contract under this part in relation to the individual, including, but not... in marketing the plan to the individual. (ii) The individual meets other exceptional circumstances as...
NPP Krsko Periodic Safety Review action plan
International Nuclear Information System (INIS)
Bilic Zabric, T.
2006-01-01
In the current, internationally accepted, safety philosophy Periodic Safety Reviews (PSRs) are comprehensive reviews aimed at the verification that an operating NPP remains safe when judged against current safety objectives and practices and that adequate arrangements are in place to maintain an acceptable level of safety. These reviews are complementary to the routine and special safety reviews. They are long time-scale reviews intended to deal with the cumulative effects of plant ageing, modifications, operating experience and technical developments, which are not so easily comprehended over the shorter time-scale routine of safety reviews. The review was completed in 2005 and the next period will see the implementation of the action plan including some plant upgrades. The action plan lists issues that should be implemented at NPP Krsko together with associated milestones. The milestones were assumed based on best estimate resource availability and their ends can be potentially floated. In some cases, multiple corrective measures may be postulated to provide resolution for a given safety issue. The Slovenian Nuclear Safety Administration by decree approved the first periodic safety review and the implementation plan of activities arising from it. The entire implementation plan must be carried out by 15 October 2010. Report on the second periodic safety review must be submitted by the NEK not later than 15 December 2013. (author)
Ultrasound periodic inspections of reactor pressure vessels
International Nuclear Information System (INIS)
Haniger, L.
1980-01-01
Two versions are described of ultrasonic equipment for periodic inspections of reactor pressure vessels. One uses the principle of exchangeable programmators with solid-state logic while the other uses programmable logic with semiconductor memories. The equipment is to be used for inspections of welded joints on the upper part of the V-1 reactor pressure vessel. (L.O.)
5 CFR 2634.908 - Reporting periods.
2010-01-01
... DISCLOSURE, QUALIFIED TRUSTS, AND CERTIFICATES OF DIVESTITURE Confidential Financial Disclosure Reports § 2634.908 Reporting periods. (a) Incumbents. Each confidential financial disclosure report filed under... information required to be reported according to the provisions of this subpart for the preceding calendar...
Periodic and in-service inspection programs
International Nuclear Information System (INIS)
Dinu, M.
2000-01-01
Periodic and in-service inspection programs for Cernavoda NPP consists of periodic inspections of CANDU NPP components CSAN N-285.4 and CSAN N-285.4, in-service inspections and repair and modifications general inspection. Periodic inspection program document (PIPD) determines the systems and components subject to inspection, the category of the inspection, techniques, areas and other details.The current status of the inspection programs is presented, including containment , erosion/corrosion, pressure vessel support and snubbers, main steam lines inspection programs. Qualification program in Cernavoda NPP involves equipment qualification in the on-site laboratory, yearly certification, special equipment qualification in the National Institute of Metrology. All procedures are approved by the ISCIR (regulatory body for pressure vessel and lifting equipment) and CNCAN (National Commission on Nuclear Activities Control). Qualification of the personnel is performed according to the ISCIR Technical prescription CR 11/82 for up to 3 year period. Final qualification and licensing is performed by CNCAN
Anomalous periodic disruptions in tokamak plasma
International Nuclear Information System (INIS)
Montvai, A.; Tegze, M.; Valyi, I.
1982-09-01
Anomalously strong, periodic instabilities were observed in the MT-1 tokamak. Characteristics of these instabilities were partly similar to those of internal disruptions, but there were features making them different from the normal relaxational oscillations. Basic characteristics of the phenomenon were studied with the aid of generally used diagnostics. (author)
2010-01-01
... Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS GUIDELINES FOR SUBSIDIZING AIR CARRIERS PROVIDING ESSENTIAL AIR TRANSPORTATION § 271.8 Rate period... place essential air service level; or (5) The uncertainties of the market or other circumstances warrant...
Periodic Solutions for Circular Restricted -Body Problems
Directory of Open Access Journals (Sweden)
Xiaoxiao Zhao
2013-01-01
Full Text Available For circular restricted -body problems, we study the motion of a sufficiently small mass point (called the zero mass point in the plane of equal masses located at the vertices of a regular polygon. By using variational minimizing methods, for some , we prove the existence of the noncollision periodic solution for the zero mass point with some fixed wingding number.
Mental Illness in the Peripartum Period
Ostler, Teresa
2009-01-01
Women are particularly vulnerable in the peripartum period for either developing a mental illness or suffering symptom exacerbation. These illnesses are often experienced covertly, however, and women may not seek out professional help, even though their symptoms may be seriously affecting their well-being and parenting. This article provides an…
Isomeric periodic mesoporous organosilicas with controllable properties
Vercaemst, C.; Ide, I.; Friedrich, H.; de Jong, K.P.; Verpoort, F.; van der Voort, P.
2009-01-01
The synthesis procedure for isomeric periodic mesoporous organosilicas with E-configured ethenylene bridges was investigated using the homemade pure E-isomer of 1,2-bis(triethoxysilyl)ethene. The pH, aging temperature and the presence of cosolvents played a key role in obtaining well-ordered
The Different Periodic Tables of Dmitrii Mendeleev
Laing, Michael
2008-01-01
Between 1869 and 1905 the Russian chemist Dmitrii Mendeleev published several tables with different arrangements of the chemical elements. Four of these are compared with periodic tables by Russian scientists from 1934 and 1969. The difficulties caused by the lanthanoid elements are clearly seen in the table of 1905, which satisfactorily includes…
Ecological periodic tables for estuarine habitats
Southwood (1977; J Anim Ecol 46: 337-365) compared the situation in ecology to that in chemistry before the development of the periodic table when each fact, for example, the solubility or reactivity of a chemical element, had to be discovered independently and remembered in isol...
Relating Functional Groups to the Periodic Table
Struyf, Jef
2009-01-01
An introduction to organic chemistry functional groups and their ionic variants is presented. Functional groups are ordered by the position of their specific (hetero) atom in the periodic table. Lewis structures are compared with their corresponding condensed formulas. (Contains 5 tables.)
Decision Making during the Psychological Refractory Period
Zylberberg, Ariel; Ouellette, Brian; Sigman, Mariano; Roelfsema, Pieter R.
2012-01-01
In spite of its massively parallel architecture [1], the human brain is fundamentally limited if required to perform two tasks at the same time [2, 3]. This limitation can be studied with the psychological refractory period (PRP) paradigm, where two stimuli that require speeded responses occur in
Resonances in a periodically driven bosonic system.
Quelle, Anton; Smith, Cristiane Morais
2017-11-01
Periodically driven systems are a common topic in modern physics. In optical lattices specifically, driving is at the origin of many interesting phenomena. However, energy is not conserved in driven systems, and under periodic driving, heating of a system is a real concern. In an effort to better understand this phenomenon, the heating of single-band systems has been studied, with a focus on disorder- and interaction-induced effects, such as many-body localization. Nevertheless, driven systems occur in a much wider context than this, leaving room for further research. Here, we fill this gap by studying a noninteracting model, characterized by discrete, periodically spaced energy levels that are unbounded from above. We couple these energy levels resonantly through a periodic drive, and discuss the heating dynamics of this system as a function of the driving protocol. In this way, we show that a combination of stimulated emission and absorption causes the presence of resonant stable states. This will serve to elucidate the conditions under which resonant driving causes heating in quantum systems.
Polarization of a periodic solar microwave burst
Energy Technology Data Exchange (ETDEWEB)
Kaufmann, P [Universidade Mackenzie, Sao Paulo (Brazil). Centro de Radio-Astronomia e Astrofisica
1976-09-01
No fluctuations in polarization have been found during a 7 GHz solar burst showing 17s periodic pulses in intensity. Polarization effects can be produced by the propagation media in the active centre, which are not affected directly by the burst source, but situated more deeply than the observed heights at that microwave frequency.
Audibility of harmonics in periodic "white noise"
Duifhuis, H.
1973-01-01
The finding that spectrally suppressed high harmonics (n>16) in a periodic pulse are perceptible has been related [H. Duifhuis, J. Acoust. Soc. Amer. 48, 888–893 (1970); 49, 1155–1163 (1971)] to the ear's limited resolving power in peripheral frequency analysis. The limited frequency resolution
Audibility of harmonics in 'periodic white noise'
Duifhuis, H.; Tomesen, H.H.
1970-01-01
In a previous article (Duifhuis, 1970) results' concerning the audibility of harmonics in a periodic pulse have been presented. Each of the lower harmonics could be perceived separately, whereas the high harmonics were heard together as one complex signal. High harmonics, however, appeared to be
Theory of Periodic Conjugate Heat Transfer
Zudin, Yuri B
2012-01-01
This book presents the theory of periodic conjugate heat transfer in a detailed way. The effects of thermophysical properties and geometry of a solid body on the commonly used and experimentally determined heat transfer coefficient are analytically presented from a general point of view. The main objective of the book is a simplified description of the interaction between a solid body and a fluid as a boundary value problem of the heat conduction equation for the solid body. At the body surface, the true heat transfer coefficient is composed of two parts: the true mean value resulting from the solution of the steady state heat transfer problem and a periodically variable part, the periodic time and length to describe the oscillatory hydrodynamic effects. The second edition is extended by (i) the analysis of stability boundaries in helium flow at supercritical conditions in a heated channel with respect to the interaction between a solid body and a fluid; (ii) a periodic model and a method of heat transfer sim...
Forecasting with periodic autoregressive time series models
Ph.H.B.F. Franses (Philip Hans); R. Paap (Richard)
1999-01-01
textabstractThis paper is concerned with forecasting univariate seasonal time series data using periodic autoregressive models. We show how one should account for unit roots and deterministic terms when generating out-of-sample forecasts. We illustrate the models for various quarterly UK consumption
N ecklaces~ Periodic Points and Permutation Representations
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 11. Necklaces, Periodic Points and Permutation Representations - Fermat's Little Theorem. Somnath Basu Anindita Bose Sumit Kumar Sinha Pankaj Vishe. General Article Volume 6 Issue 11 November 2001 pp 18-26 ...
Dysfunctional uterine bleedings of a climacteric period
International Nuclear Information System (INIS)
Prilepskaya, V.N.
1993-01-01
Climacteric period of some women is complicated by dysfunctional uterine bleedings (DUB). Bearing in mind the fact that DUBS are caused by disorder of estrin rhysmic secretion, the paper presents the methods of differential diagnostics for investigations into functional disorders in the hypothalamus -hypophysis - ovaries - uterus system. The preference is given to roentgenologic and radioimmunologic diagnostic methods
Periodic Solutions and S-Asymptotically Periodic Solutions to Fractional Evolution Equations
Directory of Open Access Journals (Sweden)
Jia Mu
2017-01-01
Full Text Available This paper deals with the existence and uniqueness of periodic solutions, S-asymptotically periodic solutions, and other types of bounded solutions for some fractional evolution equations with the Weyl-Liouville fractional derivative defined for periodic functions. Applying Fourier transform we give reasonable definitions of mild solutions. Then we accurately estimate the spectral radius of resolvent operator and obtain some existence and uniqueness results.
Czech Academy of Sciences Publication Activity Database
Ošťádalová, Ivana; Babický, A.
2012-01-01
Roč. 61, Suppl.1 (2012), S1-S7 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) 1M0510; GA ČR(CZ) GAP303/12/1162 Institutional research plan: CEZ:AV0Z50110509 Keywords : rat * ontogenic development * presuckling period * suckling period * weaning period Subject RIV: ED - Physiology Impact factor: 1.531, year: 2012
Periodic and almost periodic solutions for multi-valued differential equations in Banach spaces
Directory of Open Access Journals (Sweden)
E. Hanebaly
2000-03-01
Full Text Available It is known that for $omega$-periodic differential equations of monotonous type, in uniformly convex Banach spaces, the existence of a bounded solution on ${Bbb R}^+$ is equivalent to the existence of an omega-periodic solution (see Haraux [5] and Hanebaly [7, 10]. It is also known that if the Banach space is strictly convex and the equation is almost periodic and of monotonous type, then the existence of a continuous solution with a precompact range is equivalent to the existence of an almost periodic solution (see Hanebaly [8]. In this note we want to generalize the results above for multi-valued differential equations.
Entropy method of measuring and evaluating periodicity of quasi-periodic trajectories
Ni, Yanshuo; Turitsyn, Konstantin; Baoyin, Hexi; Junfeng, Li
2018-06-01
This paper presents a method for measuring the periodicity of quasi-periodic trajectories by applying discrete Fourier transform (DFT) to the trajectories and analyzing the frequency domain within the concept of entropy. Having introduced the concept of entropy, analytical derivation and numerical results indicate that entropies increase as a logarithmic function of time. Periodic trajectories typically have higher entropies, and trajectories with higher entropies mean the periodicities of the motions are stronger. Theoretical differences between two trajectories expressed as summations of trigonometric functions are also derived analytically. Trajectories in the Henon-Heiles system and the circular restricted three-body problem (CRTBP) are analyzed with the indicator entropy and compared with orthogonal fast Lyapunov indicator (OFLI). The results show that entropy is a better tool for discriminating periodicity in quasiperiodic trajectories than OFLI and can detect periodicity while excluding the spirals that are judged as periodic cases by OFLI. Finally, trajectories in the vicinity of 243 Ida and 6489 Golevka are considered as examples, and the numerical results verify these conclusions. Some trajectories near asteroids look irregular, but their higher entropy values as analyzed by this method serve as evidence of frequency regularity in three directions. Moreover, these results indicate that applying DFT to the trajectories in the vicinity of irregular small bodies and calculating their entropy in the frequency domain provides a useful quantitative analysis method for evaluating orderliness in the periodicity of quasi-periodic trajectories within a given time interval.
Quasi-periodic solutions of nonlinear beam equations with quintic quasi-periodic nonlinearities
Directory of Open Access Journals (Sweden)
Qiuju Tuo
2015-01-01
Full Text Available In this article, we consider the one-dimensional nonlinear beam equations with quasi-periodic quintic nonlinearities $$ u_{tt}+u_{xxxx}+(B+ \\varepsilon\\phi(tu^5=0 $$ under periodic boundary conditions, where B is a positive constant, $\\varepsilon$ is a small positive parameter, $\\phi(t$ is a real analytic quasi-periodic function in t with frequency vector $\\omega=(\\omega_1,\\omega_2,\\dots,\\omega_m$. It is proved that the above equation admits many quasi-periodic solutions by KAM theory and partial Birkhoff normal form.
Field Optimization for short Period Undulators
Peiffer, P; Rossmanith, R; Schoerling, D
2011-01-01
Undulators dedicated to low energy electron beams, like Laser Wakefield Accelerators, require very short period lengths to achieve X-ray emission. However, at these short period length (LambdaU ~ 5 mm) it becomes difficult to reach magnetic field amplitudes that lead to a K parameter of >1, which is generally desired. Room temperature permanent magnets and even superconductive undulators using Nb-Ti as conductor material have proven insufficient to achieve the desired field amplitudes. The superconductor Nb$_{3}$Sn has the theoretical potential to achieve the desired fields. However, up to now it is limited by several technological challenges to much lower field values than theoretically predicted. An alternative idea for higher fields is to manufacture the poles of the undulator body from Holmium instead of iron or to use Nb-Ti wires with a higher superconductor/copper ratio. The advantages and challenges of the different options are compared in this contribution.
MOV reliability evaluation and periodic verification scheduling
Energy Technology Data Exchange (ETDEWEB)
Bunte, B.D.
1996-12-01
The purpose of this paper is to establish a periodic verification testing schedule based on the expected long term reliability of gate or globe motor operated valves (MOVs). The methodology in this position paper determines the nominal (best estimate) design margin for any MOV based on the best available information pertaining to the MOVs design requirements, design parameters, existing hardware design, and present setup. The uncertainty in this margin is then determined using statistical means. By comparing the nominal margin to the uncertainty, the reliability of the MOV is estimated. The methodology is appropriate for evaluating the reliability of MOVs in the GL 89-10 program. It may be used following periodic testing to evaluate and trend MOV performance and reliability. It may also be used to evaluate the impact of proposed modifications and maintenance activities such as packing adjustments. In addition, it may be used to assess the impact of new information of a generic nature which impacts safety related MOVs.
[Endocrinopathies during the postpartum period. Management].
Gallo-Vallejo, J L; Gallo-Vallejo, F J
2015-03-01
The various endocrinopathies that may occur during the postpartum period are described. The most important and common is gestational and pre-gestational diabetes, but other less common, and also very important ones, are mentioned such as hypopituitarism (Sheehan's syndrome and lymphocytic hypophysitis) and thyroid disorders, pre-existing (hyperthyroidism and hypothyroidism), or postpartum onset (postpartum thyroiditis and Graves' disease). After describing their characteristics, the emphasis is placed on the proper management of these endocrine diseases, some of them which exclusively appear during the postpartum period. Copyright © 2014 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España. All rights reserved.
MOV reliability evaluation and periodic verification scheduling
International Nuclear Information System (INIS)
Bunte, B.D.
1996-01-01
The purpose of this paper is to establish a periodic verification testing schedule based on the expected long term reliability of gate or globe motor operated valves (MOVs). The methodology in this position paper determines the nominal (best estimate) design margin for any MOV based on the best available information pertaining to the MOVs design requirements, design parameters, existing hardware design, and present setup. The uncertainty in this margin is then determined using statistical means. By comparing the nominal margin to the uncertainty, the reliability of the MOV is estimated. The methodology is appropriate for evaluating the reliability of MOVs in the GL 89-10 program. It may be used following periodic testing to evaluate and trend MOV performance and reliability. It may also be used to evaluate the impact of proposed modifications and maintenance activities such as packing adjustments. In addition, it may be used to assess the impact of new information of a generic nature which impacts safety related MOVs
Quasiaxially symmetric stellarators with three field periods
International Nuclear Information System (INIS)
Garabedian, P.; Ku, L.
1999-01-01
Compact hybrid configurations with two field periods have been studied recently as candidates for a proof of principle experiment at the Princeton Plasma Physics Laboratory. This project has led us to the discovery of a family of quasiaxially symmetric stellarators with three field periods that have significant advantages, although their aspect ratios are a little larger. They have reversed shear and perform better in a local analysis of ballooning modes. Nonlinear equilibrium and stability calculations predict that the average beta limit will be at least as high as 4% if the bootstrap current turns out to be as big as that expected in comparable tokamaks. The concept relies on a combination of helical fields and bootstrap current to achieve adequate rotational transform at low aspect ratio. copyright 1999 American Institute of Physics
Episodic spontaneous hypothermia: a periodic childhood syndrome.
Ruiz, Cynthia; Gener, Blanca; Garaizar, Carmen; Prats, José M
2003-04-01
Episodic spontaneous hypothermia is an infrequent disorder, with unknown pathogenic mechanisms. A systemic cause or underlying brain lesion has not been found for the disease. We report four new patients, 3-9 years old, with episodic hypothermia lower than 35 degrees C, marked facial pallor, and absent shivering. The episodes could last a few hours or four days, and recurred once a week or every 2-3 months. Two patients also demonstrated bradycardia, mild hypertension, and somnolence during the events; in one of them, profuse sweating was also a feature, and all four presented with either headache, a periodic childhood syndrome, or both (recurrent abdominal pain, cyclic vomiting, or vertigo). Three patients reported a family history of migraine. Neurologic examination, endocrine function, and imaging studies were normal. Migraine prophylactic therapy was of moderate efficacy. Spontaneous resolution was observed in one patient. The clinical characteristics of the syndrome allow for its inclusion as a childhood periodic syndrome related to migraine.
The Bloch Approximation in Periodically Perforated Media
International Nuclear Information System (INIS)
Conca, C.; Gomez, D.; Lobo, M.; Perez, E.
2005-01-01
We consider a periodically heterogeneous and perforated medium filling an open domain Ω of R N . Assuming that the size of the periodicity of the structure and of the holes is O(ε),we study the asymptotic behavior, as ε → 0, of the solution of an elliptic boundary value problem with strongly oscillating coefficients posed in Ω ε (Ω ε being Ω minus the holes) with a Neumann condition on the boundary of the holes. We use Bloch wave decomposition to introduce an approximation of the solution in the energy norm which can be computed from the homogenized solution and the first Bloch eigenfunction. We first consider the case where Ωis R N and then localize the problem for abounded domain Ω, considering a homogeneous Dirichlet condition on the boundary of Ω
Controller Synthesis for Periodically Forced Chaotic Systems
Basso, Michele; Genesio, Roberto; Giovanardi, Lorenzo
Delayed feedback controllers are an appealing tool for stabilization of periodic orbits in chaotic systems. Despite their conceptual simplicity, specific and reliable design procedures are difficult to obtain, partly also because of their inherent infinite-dimensional structure. This chapter considers the use of finite dimensional linear time invariant controllers for stabilization of periodic solutions in a general class of sinusoidally forced nonlinear systems. For such controllers — which can be interpreted as rational approximations of the delayed ones — we provide a computationally attractive synthesis technique based on Linear Matrix Inequalities (LMIs), by mixing results concerning absolute stability of nonlinear systems and robustness of uncertain linear systems. The resulting controllers prove to be effective for chaos suppression in electronic circuits and systems, as shown by two different application examples.
The necessity of periodic fire safety review
International Nuclear Information System (INIS)
Mowrer, D.S.
1998-01-01
Effective fire safety requires the coordinated integration of many diverse elements. Clear fire safety objectives are defined by plant management and/or regulatory authorities. Extensive and time-consuming systematic analyses are performed. Fire safety features (both active and passive) are installed and maintained, and administrative programs are established and implemented to achieve the defined objectives. Personnel are rigorously trained. Given the time, effort and monetary resources expended to achieve a specific level of fire safety, conducting periodic assessments to verify that the specified level of fire safety has been achieved and is maintained is a matter of common sense. Periodic fire safety reviews and assessment play an essential role in assuring continual nuclear safety in the world's power plants
Diffraction of polarized light on periodic structures
International Nuclear Information System (INIS)
Bukanina, V; Divakov, D; Tyutyunnik, A; Hohlov, A
2012-01-01
Periodic structures as photonic crystals are widely used in modern laser devices, communication technologies and for creating various beam splitters and filters. Diffraction gratings are applied for creating 3D television sets, DVD and Blu-ray drives and reflective structures (Berkley mirror). It is important to simulate diffraction on such structures to design optical systems with predetermined properties based on photonic crystals and diffraction gratings. Methods of simulating diffraction on periodic structures uses theory of Floquet-Bloch and rigorous coupled-wave analysis (RCWA). Current work is dedicated to analysis of photonic band gaps and simulating diffraction on one-dimensional binary diffraction grating using RCWA. The Maxwell's equations for isotropic media and constitutive relations based on the cgs system were used as a model.
Infinte Periodic Structure of Lightweight Elements
DEFF Research Database (Denmark)
Domadiya, Parthkumar Gandalal; Andersen, Lars Vabbersgaard; Sorokin, Sergey
2013-01-01
Lightweight wooden structures have become more popular as a sustainable, environmental- friendly and cost-effective alternative to concrete, steel and masonry buildings. However, there are certain drawbacks regarding noise and vibration due to the smaller weight and stiffness of wooden buildings....... Furthermore, lightweight building elements are typically periodic structures that behave as filters for sound propagation within certain frequency ranges (stop bands), thus only allowing transmission within the pass bands. Hence, traditional methods based on statistical energy analysis cannot be used...... for proper dynamic assessment of lightweight buildings. Instead, this paper discusses and compares the use of finite element analysis and a wave approach based on Floquet theory. The present analysis has focus on the effect of periodicity on vibration transmission within semi-infinite beam structures. Two...
Multichannel long period seismic data acquisition system
International Nuclear Information System (INIS)
Kolvankar, V.G.; Rao, D.S.
1990-01-01
This paper discusses the specifications and performance of an eight channel long period seismic digital data acquisition system, which is developed and installed at Seismic Array Station, Gauribidanur, Karnataka State. The paper describes how these data in an unedited form are recorded on a single track of magnetic tape inter-mittantly, which has resulted in recording of 50 days data on a single tapespool. A time indexing technique which enables quick access to any desired portion of a recorded tape is also discussed. Typical examples of long period seismic event signals recorded by this system are also illustrated. Various advantages, the system provides over the analog multichannel instrumentation tape recording system, operating at Seismic Array Station for th e last two decades, are also discussed. (author). 7 figs
Equivariant surgery theories and their periodicity properties
Dovermann, Karl Heinz
1990-01-01
The theory of surgery on manifolds has been generalized to categories of manifolds with group actions in several different ways. This book discusses some basic properties that such theories have in common. Special emphasis is placed on analogs of the fourfold periodicity theorems in ordinary surgery and the roles of standard general position hypotheses on the strata of manifolds with group actions. The contents of the book presuppose some familiarity with the basic ideas of surgery theory and transformation groups, but no previous knowledge of equivariant surgery is assumed. The book is designed to serve either as an introduction to equivariant surgery theory for advanced graduate students and researchers in related areas, or as an account of the authors' previously unpublished work on periodicity for specialists in surgery theory or transformation groups.
Testing for entanglement with periodic coarse graining
Tasca, D. S.; Rudnicki, Łukasz; Aspden, R. S.; Padgett, M. J.; Souto Ribeiro, P. H.; Walborn, S. P.
2018-04-01
Continuous-variable systems find valuable applications in quantum information processing. To deal with an infinite-dimensional Hilbert space, one in general has to handle large numbers of discretized measurements in tasks such as entanglement detection. Here we employ the continuous transverse spatial variables of photon pairs to experimentally demonstrate entanglement criteria based on a periodic structure of coarse-grained measurements. The periodization of the measurements allows an efficient evaluation of entanglement using spatial masks acting as mode analyzers over the entire transverse field distribution of the photons and without the need to reconstruct the probability densities of the conjugate continuous variables. Our experimental results demonstrate the utility of the derived criteria with a success rate in entanglement detection of ˜60 % relative to 7344 studied cases.
Nonlinearities in Periodic Structures and Metamaterials
Denz, Cornelia; Kivshar, Yuri S
2010-01-01
Optical information processing of the future is associated with a new generation of compact nanoscale optical devices operating entirely with light. Moreover, adaptive features such as self-guiding, reconfiguration and switching become more and more important. Nonlinear devices offer an enormous potential for these applications. Consequently, innovative concepts for all-optical communication and information technologies based on nonlinear effects in photonic-crystal physics and nanoscale devices as metamaterials are of high interest. This book focuses on nonlinear optical phenomena in periodic media, such as photonic crystals, optically-induced, adaptive lattices, atomic lattices or metamaterials. The main purpose is to describe and overview new physical phenomena that result from the interplay between nonlinearities and structural periodicities and is a guide to actual and future developments for the expert reader in optical information processing, as well as in the physics of cold atoms in optical lattices.
Periodically Driven Array of Single Rydberg Atoms
Basak, Sagarika; Chougale, Yashwant; Nath, Rejish
2018-03-01
An array of single Rydberg atoms driven by a temporally modulated atom-field detuning is studied. The periodic modulation effectively modifies the Rabi coupling, leading to unprecedented dynamics in the presence of Rydberg-Rydberg interactions, in particular, blockade enhancement, antiblockades, and state-dependent population trapping. Interestingly, the Schrieffer-Wolf transformation reveals a fundamental process in Rydberg gases, correlated Rabi coupling, which stems from the extended nature of the Rydberg-Rydberg interactions. Also, the correlated coupling provides an alternative depiction for the Rydberg blockade, exhibiting a nontrivial behavior in the presence of periodic modulation. The dynamical localization of a many-body configuration in a driven Rydberg lattice is discussed.
Shock dynamics in layered periodic media
Ketcheson, David I.
2012-01-01
Solutions of constant-coeffcient nonlinear hyperbolic PDEs generically develop shocks, even if the initial data is smooth. Solutions of hyperbolic PDEs with variable coeffcients can behave very differently. We investigate formation and stability of shock waves in a one-dimensional periodic layered medium by a computational study of time-reversibility and entropy evolution. We find that periodic layered media tend to inhibit shock formation. For small initial conditions and large impedance variation, no shock formation is detected even after times much greater than the time of shock formation in a homogeneous medium. Furthermore, weak shocks are observed to be dynamically unstable in the sense that they do not lead to significant long-term entropy decay. We propose a characteristic condition for admissibility of shocks in heterogeneous media that generalizes the classical Lax entropy condition and accurately predicts the formation or absence of shocks in these media.
Periodically distributed objects with quasicrystalline diffraction pattern
Energy Technology Data Exchange (ETDEWEB)
Wolny, Janusz, E-mail: wolny@fis.agh.edu.pl; Strzalka, Radoslaw [Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Krakow (Poland); Kuczera, Pawel [Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Krakow (Poland); Laboratory of Crystallography, ETH Zurich, Wolfgang-Pauli-Strasse 10, CH-8093 Zurich (Switzerland)
2015-03-30
It is possible to construct fully periodically distributed objects with a diffraction pattern identical to the one obtained for quasicrystals. These objects are probability distributions of distances obtained in the statistical approach to aperiodic structures distributed periodically. The diffraction patterns have been derived by using a two-mode Fourier transform—a very powerful method not used in classical crystallography. It is shown that if scaling is present in the structure, this two-mode Fourier transform can be reduced to a regular Fourier transform with appropriately rescaled scattering vectors and added phases. Detailed case studies for model sets 1D Fibonacci chain and 2D Penrose tiling are discussed. Finally, it is shown that crystalline, quasicrystalline, and approximant structures can be treated in the same way.
Renormalization transformation of periodic and aperiodic lattices
International Nuclear Information System (INIS)
Macia, Enrique; Rodriguez-Oliveros, Rogelio
2006-01-01
In this work we introduce a similarity transformation acting on transfer matrices describing the propagation of elementary excitations through either periodic or Fibonacci lattices. The proposed transformation can act at two different scale lengths. At the atomic scale the transformation allows one to express the systems' global transfer matrix in terms of an equivalent on-site model one. Correlation effects among different hopping terms are described by a series of local phase factors in that case. When acting on larger scale lengths, corresponding to short segments of the original lattice, the similarity transformation can be properly regarded as describing an effective renormalization of the chain. The nature of the resulting renormalized lattice significantly depends on the kind of order (i.e., periodic or quasiperiodic) of the original lattice, expressing a delicate balance between chemical complexity and topological order as a consequence of the renormalization process
Molecular Dynamics with Helical Periodic Boundary Conditions
Czech Academy of Sciences Publication Activity Database
Kessler, Jiří; Bouř, Petr
2014-01-01
Roč. 35, č. 21 (2014), s. 1552-1559 ISSN 0192-8651 R&D Projects: GA ČR GAP208/11/0105; GA MŠk(CZ) LH11033 Grant - others:GA AV ČR(CZ) M200551205; GA MŠk(CZ) LM2010005 Institutional support: RVO:61388963 Keywords : periodic boundary conditions * helical symmetry * molecular dynamics * protein structure * amyloid fibrils Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.589, year: 2014
Possible Rivaroxaban Failure during the Postpartum Period.
Rudd, Kelly M; Winans, Amanda R McFee; Panneerselvam, Narmadha
2015-11-01
Rivaroxaban, a factor Xa inhibitor, is a direct-acting oral anticoagulant (DOAC) indicated for the treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE), and for reducing the risk of DVT and PE recurrence. To our knowledge, no data are presently available to guide DOAC dosing in the postpartum period when pharmacokinetic and pharmacodynamic changes induced by pregnancy have an impact on drug clearance and increase hypercoagulability for a period of 6-8 weeks after delivery. We describe the case of a 35-year-old postpartum woman who presented to the emergency department with a diagnosis of a new multiple segmental PE 5 days after starting rivaroxaban therapy for a diagnosis of DVT. No precipitating cause, including noncompliance, was identified as a source of thrombosis embolization or extension. The patient was admitted, a heparin infusion was started for the management of PE, and rivaroxaban was discontinued. She was transitioned to enoxaparin 1 mg/kg (90 mg) subcutaneously every 12 hours the next day, bridged to warfarin, and discharged home on the overlapping regimen with close follow-up by the pharmacist-managed outpatient Anticoagulation Management Service. To our knowledge, this is the first case report of potential failure associated with rivaroxaban therapy in the postpartum period, possibly due to pharmacokinetic alterations seen in the postpartum period contributing to decreased drug exposure, yielding reduced anticoagulant efficacy. Clinicians should carefully weigh the risks and benefits of DOAC therapy in postpartum patients or other special populations requiring anticoagulation therapy. This report also highlights the need for further research identifying the impact of pharmacokinetic changes induced by special populations and the need to develop monitoring assays for such clinical situations. © 2015 Pharmacotherapy Publications, Inc.
Theoretical chemistry periodicities in chemistry and biology
Eyring, Henry
1978-01-01
Theoretical Chemistry: Periodicities in Chemistry and Biology, Volume 4 covers the aspects of theoretical chemistry. The book discusses the stably rotating patterns of reaction and diffusion; the chemistry of inorganic systems exhibiting nonmonotonic behavior; and population cycles. The text also describes the mathematical modeling of excitable media in neurobiology and chemistry; oscillating enzyme reactions; and oscillatory properties and excitability of the heart cell membrane. Selected topics from the theory of physico-chemical instabilities are also encompassed. Chemists, mechanical engin
Periodic Pricing of Seasonal Products in Retailing
Gabriel R. Bitran; Susana V. Mondschein
1997-01-01
This paper studies intertemporal pricing policies when selling seasonal products in retail stores. We first present a continuous time model where a seller faces a stochastic arrival of customers with different valuations of the product. For this model, we characterize the optimal pricing policies as functions of time and inventory. We use this model as a benchmark against which we compare more realistic models that consider periodic pricing reviews. We show that the structure of the optimal p...
Periodic inspections of the primary system
International Nuclear Information System (INIS)
Dufour, L.B.
1978-01-01
An impression is given of the inspection techniques, preparations and background for periodic examinations of the primary system of the Dodewaard Nuclear Reactor over the past 10 years. Unfortunately reliable integral inspection techniques to enable 'listening-in' to developing faults, are not yet available. Until they are, inspections will continue to be executed from a distance using different continuous methods, often under water and with a shortage of space and in the presence of ionising radiations. (C.F.)
The Cerebellum, Sensitive Periods, and Autism
Wang, Samuel S.-H.; Kloth, Alexander D.; Badura, Aleksandra
2014-01-01
Cerebellar research has focused principally on adult motor function. However, the cerebellum also maintains abundant connections with nonmotor brain regions throughout postnatal life. Here we review evidence that the cerebellum may guide the maturation of remote nonmotor neural circuitry and influence cognitive development, with a focus on its relationship with autism. Specific cerebellar zones influence neocortical substrates for social interaction, and we propose that sensitive-period disruption of such internal brain communication can account for autism's key features. PMID:25102558
About the cumulants of periodic signals
Barrau, Axel; El Badaoui, Mohammed
2018-01-01
This note studies cumulants of time series. These functions originating from the probability theory being commonly used as features of deterministic signals, their classical properties are examined in this modified framework. We show additivity of cumulants, ensured in the case of independent random variables, requires here a different hypothesis. Practical applications are proposed, in particular an analysis of the failure of the JADE algorithm to separate some specific periodic signals.
The attenuation of the periodic table
International Nuclear Information System (INIS)
Cook, N.D.
1990-01-01
Unique among models of nuclear structure, the face-centered-cubic (FCC) lattice model predicts the attenuation of the periodic table at Z < 110 and the impossibility of superheavy nuclei. The total binding energies of superheavy nuclei in the FCC model (109 < Z < 127) were calculated on the basis of parameters obtained from a least-squares best-fit for 914 nuclei (Z < 99). No indication of increased stability is found for any of the transuranic elements
Meteorological circumstances during the 'Chernobyl-period'
International Nuclear Information System (INIS)
Ivens, R.; Lablans, W.N.; Wessels, H.R.A.
1987-01-01
The progress of the meteorological circumstances and air flows in Europe from 26th April up to 8th May 1986, which caused the spread of contaminated air originating from Chernobyl is outlined and mapped out. Furthermore a global survey is presented of the precipitation in the Netherlands during the period 2nd May to 10th May based on observations of various observation stations of the Royal Dutch Meteorologic Institute (KNMI). 11 figs.; 1 table (H.W.)
Evaluation of periodic safety status analyses
International Nuclear Information System (INIS)
Faber, C.; Staub, G.
1997-01-01
In order to carry out the evaluation of safety status analyses by the safety assessor within the periodical safety reviews of nuclear power plants safety goal oriented requirements have been formulated together with complementary evaluation criteria. Their application in an inter-disciplinary coopertion covering the subject areas involved facilitates a complete safety goal oriented assessment of the plant status. The procedure is outlined briefly by an example for the safety goal 'reactivity control' for BWRs. (orig.) [de
Quantum periods of Calabi–Yau fourfolds
Energy Technology Data Exchange (ETDEWEB)
Gerhardus, Andreas, E-mail: gerhardus@th.physik.uni-bonn.de; Jockers, Hans, E-mail: jockers@uni-bonn.de
2016-12-15
In this work we study the quantum periods together with their Picard–Fuchs differential equations of Calabi–Yau fourfolds. In contrast to Calabi–Yau threefolds, we argue that the large volume points of Calabi–Yau fourfolds generically are regular singular points of the Picard–Fuchs operators of non-maximally unipotent monodromy. We demonstrate this property in explicit examples of Calabi–Yau fourfolds with a single Kähler modulus. For these examples we construct integral quantum periods and study their global properties in the quantum Kähler moduli space with the help of numerical analytic continuation techniques. Furthermore, we determine their genus zero Gromov–Witten invariants, their Klemm–Pandharipande meeting invariants, and their genus one BPS invariants. In our computations we emphasize the features attributed to the non-maximally unipotent monodromy property. For instance, it implies the existence of integral quantum periods that at large volume are purely worldsheet instanton generated. To verify our results, we also present intersection theory techniques to enumerate lines with a marked point on complete intersection Calabi–Yau fourfolds in Grassmannian varieties.
Limiting rotational period of neutron stars
Glendenning, Norman K.
1992-11-01
We seek an absolute limit on the rotational period for a neutron star as a function of its mass, based on the minimal constraints imposed by Einstein's theory of relativity, Le Chatelier's principle, causality, and a low-density equation of state, uncertainties in which can be evaluated as to their effect on the result. This establishes a limiting curve in the mass-period plane below which no pulsar that is a neutron star can lie. For example, the minimum possible Kepler period, which is an absolute limit on rotation below which mass shedding would occur, is 0.33 ms for a M=1.442Msolar neutron star (the mass of PSR1913+16). A still lower curve, based only on the structure of Einstein's equations, limits any star whatsoever to lie in the plane above it. Hypothetical stars such as strange stars, if the matter of which they are made is self-bound in bulk at a sufficiently large equilibrium energy density, can lie in the region above the general-relativistic forbidden region, and in the region forbidden to neutron stars.
Limiting rotational period of neutron stars
International Nuclear Information System (INIS)
Glendenning, N.K.
1992-01-01
We seek an absolute limit on the rotational period for a neutron star as a function of its mass, based on the minimal constraints imposed by Einstein's theory of relativity, Le Chatelier's principle, causality, and a low-density equation of state, uncertainties in which can be evaluated as to their effect on the result. This establishes a limiting curve in the mass-period plane below which no pulsar that is a neutron star can lie. For example, the minimum possible Kepler period, which is an absolute limit on rotation below which mass shedding would occur, is 0.33 ms for a M=1.442M circle-dot neutron star (the mass of PSR1913+16). A still lower curve, based only on the structure of Einstein's equations, limits any star whatsoever to lie in the plane above it. Hypothetical stars such as strange stars, if the matter of which they are made is self-bound in bulk at a sufficiently large equilibrium energy density, can lie in the region above the general-relativistic forbidden region, and in the region forbidden to neutron stars
Broadband Vibration Attenuation Using Hybrid Periodic Rods
Directory of Open Access Journals (Sweden)
S. Asiri
2008-12-01
Full Text Available This paper presents both theoretically and experimentally a new kind of a broadband vibration isolator. It is a table-like system formed by four parallel hybrid periodic rods connected between two plates. The rods consist of an assembly of periodic cells, each cell being composed of a short rod and piezoelectric inserts. By actively controlling the piezoelectric elements, it is shown that the periodic rods can efficiently attenuate the propagation of vibration from the upper plate to the lower one within critical frequency bands and consequently minimize the effects of transmission of undesirable vibration and sound radiation. In such a system, longitudinal waves can propagate from the vibration source in the upper plate to the lower one along the rods only within specific frequency bands called the "Pass Bands" and wave propagation is efficiently attenuated within other frequency bands called the "Stop Bands". The spectral width of these bands can be tuned according to the nature of the external excitation. The theory governing the operation of this class of vibration isolator is presented and their tunable filtering characteristics are demonstrated experimentally as functions of their design parameters. This concept can be employed in many applications to control the wave propagation and the force transmission of longitudinal vibrations both in the spectral and spatial domains in an attempt to stop/attenuate the propagation of undesirable disturbances.
Population structure of the Classic period Maya.
Scherer, Andrew K
2007-03-01
This study examines the population structure of Classic period (A.D. 250-900) Maya populations through analysis of odontometric variation of 827 skeletons from 12 archaeological sites in Mexico, Guatemala, Belize, and Honduras. The hypothesis that isolation by distance characterized Classic period Maya population structure is tested using Relethford and Blangero's (Hum Biol 62 (1990) 5-25) approach to R matrix analysis for quantitative traits. These results provide important biological data for understanding ancient Maya population history, particularly the effects of the competing Tikal and Calakmul hegemonies on patterns of lowland Maya site interaction. An overall F(ST) of 0.018 is found for the Maya area, indicating little among-group variation for the Classic Maya sites tested. Principal coordinates plots derived from the R matrix analysis show little regional patterning in the data, though the geographic outliers of Kaminaljuyu and a pooled Pacific Coast sample did not cluster with the lowland Maya sites. Mantel tests comparing the biological distance matrix to a geographic distance matrix found no association between genetic and geographic distance. In the Relethford-Blangero analysis, most sites possess negative or near-zero residuals, indicating minimal extraregional gene flow. The exceptions were Barton Ramie, Kaminaljuyu, and Seibal. A scaled R matrix analysis clarifies that genetic drift is a consideration for understanding Classic Maya population structure. All results indicate that isolation by distance does not describe Classic period Maya population structure. (c) 2006 Wiley-Liss, Inc.
Diffusion of chains in a periodic potential
Terranova, G. R.; Mártin, H. O.; Aldao, C. M.
2017-09-01
We studied the diffusion of 1D rigid chains in a square wave potential of period T. We considered chains of type A (composed of N particles A) and chains of type A-B (composed of N/2 particles A and N/2 particles B). The square wave potential represents domains, a lamellar structure observed for block copolymers, in which the repulsive δ energy between each A particle (B particle) of the chain and B particles (A particles) of the medium where the chains diffuse. From Monte Carlo simulations and analytical results it is found that the normalized diffusivity D, for N\\ll T , presents a universal behavior as a function of X = Nδ for chains of type A and X = (Nδ - lnT 2) for chains of type A-B, with and exponential decay for large values of X. For fixed values of δ and T, D is a periodic function of N with period T and 2T for chains of type A and type A-B, respectively.
Electromagnetic radiation of electrons in periodic structures
International Nuclear Information System (INIS)
Potylitsyn, Alexander Petrovich
2011-01-01
Periodic magnetic structures (undulators) are widely used in accelerators to generate monochromatic undulator radiation (UR) in the range from far infrared to the hard X-ray region. Another periodic crystalline structure is used to produce quasimonochromatic polarized photon beams via the coherent bremsstrahlung mechanism (CBS). Due to such characteristics as monochromaticity, polarization and adjustability, these types of radiation is of large interest for applied and basic research of accelerator-emitted radiation. The book provides a detailed overview of the fundamental principles behind electromagnetic radiation emitted from accelerated charged particles (e.g. UR, CBS, radiation of fast electrons in Laser flash fields) as well as a unified description of relatively new radiation mechanisms which attracted great interest in recent years. This are the so-called polarization radiation excited by the Coulomb field of incident particles in periodic structures, parametric X-rays, resonant transition radiation and the Smith-Purcell effect. Characteristics of such radiation sources and perspectives of their usage are discussed. The recent experimental results as well as their interpretation are presented. (orig.)
Economic Crimes In The Period Of Nazaret
Directory of Open Access Journals (Sweden)
maryam mansoori
2015-12-01
Full Text Available In Other Words, The Victim Of Crime Or Bad Act And Contrary To The Provisions Specified In A Society. Breaking The Law In One Way Or Another In All Sections Of Society Or Culture There And Just Not Certain. Given The Importance Of Nazareth As A Crucial Moment In History, Investigate The Crime As One Of The Most Important Events Of This Period Can Reveal Its Many Ambiguities In The Fields Of Committing Economic Crimes. Accordingly, In This Study We Try Economic Crimes Testament Naseri Typology And The Role Of Various Factors In This Phenomenon, Particularly In Its Dual Role Of Government Is. Therefore, Relying On Historical Documents And Library Resources Available And The Statistical Analysis Of Crimes Of This Period, The Description Of The Economic Situation Of Naseri Age, The Type Of Economic Crime In The Period Studied And Said Some Of The Factors Contributing To The Occurrence Of This Crime, As Far As Possible From The Viewpoint Of Analytical Thought. According To The Findings Obtained From Different Types Of Economic Crimes, The Murder Of A 7/58%, The Highest Rate Of Opium Drawing 2/0% Were Allocated To The Lowest. Although The Government Of Nazareth Was The Main Cause Of Action In Dealing With Criminals However Its Way To Provide Mass Media, And In Many Cases They Are Also Added On.
MR imaging in the neonatal period
International Nuclear Information System (INIS)
Aida, Noriko; Inuzuka, Michiko; Odagiri, Kunio
1994-01-01
We reviewed 118 MR examinations in the neonatal period to define its indication, problem, and usefulness. The patients were 58 term infants under 28 days of age and 46 preterm infants under 46 week of their post conceptional age. Almost all patients were examined under sedation. We used pulse wave monitoring and respiration was monitored only by observing the chest motion. Hot water bags were used in some cases to keep the patient warm. No serious accidents or sequelae occurred, although a very few patients had a brief apnea attacks during sedation and some developed hypothermia after the examination. The MR provided many useful information such as basal ganglial lesions after perinatal asphyxia and multiplaner demonstration of the CN5 anomalies which no other modality could. The detection rate of abnormality in the study was about 65%. Although MR studies in the neonatal period have many difficulties to be overcome including sedation, maintenance of body temperature and monitoring, they can demonstrate useful information that are helpful for their early treatment and care. Thus we believe that the MR study should be performed in a more positive manner in a variety of clinical setting in the neonatal period. (author)
[Vaginitis and vaginosis. Comparison of two periods].
Ceruti, M; Canestrelli, M; Piantelli, G; Amone, F; Condemi, V; De Paolis, P; Ludovici, G; Somenzi, P
1993-10-01
Vaginitis is the most frequent gynecological disease. It is characterized by objective and subjective signs of inflammation and differs from bacterial vaginosis (BV) which is an abnormal condition of the vaginal ecosystem caused by the excessive growth of aerobic and anaerobic flora normally present in the vagina with an increased risk of pelvic inflammatory disease (PID). The authors report the results of a study carried out at the Centre for Gynecological Infections at the Clinic of Obstetrics and Gynecology of the University of Parma. 828 patients were enrolled in the study during the period 1985-86 and 1559 patients during the two-year period 1991-92. The aim of the study was to evaluate variations in epidemiological data for vaginitis and bacterial vaginosis in the two periods examined. No significant changes were observed (p > 0.05) with regard to the prevalence of Ca, Tv and BV forms. On the other hand, there was a significant reduction (p vaginitis and BV showed a reduction of other microorganisms and an increase in negative vaginal swabs in adults (> 20 years old).
Student Protests. Three Periods of University Governance
Directory of Open Access Journals (Sweden)
Joan Ramon Rodriguez-Amat
2017-05-01
Full Text Available Exploring the idea of student protests as an autonomous object of research and discussion, this paper leads to the understanding that the transforming role of the university and its governance defines the possibilities for the political role of students. In this perspective, there is a particular constellation of the different forms of higher education governance that provides students with the right and even the responsibility of protesting as politically engaged citizens of the university and of the state. Approaching the transformation of the models of university governance as a set of archaeologically organised states this paper identifies the sequential roles provided to the students and the meaning of their protests and demonstrations. After visiting some antecedents of more contemporaneous student movements and protests, this paper focuses on the UK to explore three manifestations of university governance that can be roughly differentiated as the enduring democratic period that extends from the late 1960s to the late 1980s, the globalisation period that extends from the early 1990s to the mid-2000s and as the post-millennial turn. These periods, embodying three different styles of governance of higher education, not only demonstrate conformity with the political and economic contexts in which they are embeded, they also correspond to particular socio-technological and communicative ecosystems and determine the specificities of the role of the students and their capacity for political action.
MR imaging in the neonatal period
Energy Technology Data Exchange (ETDEWEB)
Aida, Noriko; Inuzuka, Michiko; Odagiri, Kunio (Kanagawa Children' s Medical Center (Japan))
1994-01-01
We reviewed 118 MR examinations in the neonatal period to define its indication, problem, and usefulness. The patients were 58 term infants under 28 days of age and 46 preterm infants under 46 week of their post conceptional age. Almost all patients were examined under sedation. We used pulse wave monitoring and respiration was monitored only by observing the chest motion. Hot water bags were used in some cases to keep the patient warm. No serious accidents or sequelae occurred, although a very few patients had a brief apnea attacks during sedation and some developed hypothermia after the examination. The MR provided many useful information such as basal ganglial lesions after perinatal asphyxia and multiplaner demonstration of the CN5 anomalies which no other modality could. The detection rate of abnormality in the study was about 65%. Although MR studies in the neonatal period have many difficulties to be overcome including sedation, maintenance of body temperature and monitoring, they can demonstrate useful information that are helpful for their early treatment and care. Thus we believe that the MR study should be performed in a more positive manner in a variety of clinical setting in the neonatal period. (author).
Economic comparison of a sixty day dry period with no dry period on Dutch dairy farms
Heeren, J.A.H.; Steeneveld, W.; Berentsen, P.B.M.
2014-01-01
In the Netherlands it is general practice that dairy cows have a dry period of six to eight weeks. Research, however, shows that omission of the dry period avoids the negative energy balance after calving with its potential negative effects on metabolic disorders, infectious diseases, and fertility.
38 CFR 3.17 - Disability and death pension; Mexican border period and later war periods.
2010-07-01
... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Disability and death pension; Mexican border period and later war periods. 3.17 Section 3.17 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS ADJUDICATION Pension, Compensation, and Dependency and Indemnity...
International Nuclear Information System (INIS)
Sun Wen; Chen Shihua; Hong Zhiming; Wang Changping
2007-01-01
A two-species periodic competition Lotka-Volterra system with time delay and diffusion is investigated. Some sufficient conditions of the existence of positive periodic solution are established for the system by using the continuation theorem of coincidence degree theory
Larson, Kathleen G.; Long, George R.; Briggs, Michael W.
2012-01-01
The mental models of both novice and advanced chemistry students were observed while the students performed a periodic table activity. The mental model framework seems to be an effective way of analyzing student behavior during learning activities. The analysis suggests that students do not recognize periodic trends through the examination of…
Periodicity and quasi-periodicity for super-integrable hamiltonian systems
International Nuclear Information System (INIS)
Kibler, M.; Winternitz, P.
1990-01-01
Classical trajectories are calculated for two Hamiltonian systems with ring shaped potentials. Both systems are super-integrable, but not maximally super-integrable, having four globally defined single-valued integrals of motion each. All finite trajectories are quasi-periodical; they become truly periodical if a commensurability condition is imposed on an angular momentum component
Directory of Open Access Journals (Sweden)
Soledad Puente
2014-01-01
Full Text Available En Chile, la rutina periodística suele responder a un proceso basado princi- palmente en la intuición, entendida como aquella reacción sobre la marcha frente a eventos de la contingencia con relevancia social. Los editores, que están a cargo de este proceso, sin importar el tipo de medio de información social en que trabajen, toman las decisiones principalmente de acuerdo con su experiencia y olfato periodístico, lo que incide directamente en la calidad de los contenidos y en su coherencia con la línea editorial del medio. Mien- tras, por un lado, la llegada de las nuevas tecnologías ha modificado el acce- so a la información de los ciudadanos, por otro, ha complejizado el trabajo en la sala de noticias, independientemente de su soporte. La noticia hoy es un commodity, lo que reduce las posibilidades de golpe periodístico y exi- ge mayores elementos de novedad. La figura del editor o gatekeeper es hoy más importante que nunca, porque es el encargado de seleccionar y jerar- quizar cuáles serán las unidades noticiosas más relevantes para la toma de decisiones de los ciudadanos. A través de entrevistas en profundidad a di- rectores, editores y periodistas de medios de referencia chilenos de diarios, televisión, agencias de noticias y nuevos medios, el equipo que presenta este trabajo revisó y sistematizó los momentos críticos del proceso de toma de decisiones periodísticas. Con esa información, diseñó un proceso genéri- co denominado, según la literatura, ‘diagrama de flujo para la modelación de procesos de negocios’, al que posteriormente se aplicó la metodología SIPOC para determinar el alcance del proceso y la matriz RECI para defi- nir actividades y roles de quienes participan en ellas. Se establecieron así las etapas imprescindibles del trabajo periodístico: proposición, decisión y seguimiento de la ejecución de la unidad noticiosa. Al finalizar el mode- lamiento, se llevó a cabo su validación por parte
Williams, Tyler D; Tolusso, Danilo V; Fedewa, Michael V; Esco, Michael R
2017-10-01
Periodization is a logical method of organizing training into sequential phases and cyclical time periods in order to increase the potential for achieving specific performance goals while minimizing the potential for overtraining. Periodized resistance training plans are proposed to be superior to non-periodized training plans for enhancing maximal strength. The primary aim of this study was to examine the previous literature comparing periodized resistance training plans to non-periodized resistance training plans and determine a quantitative estimate of effect on maximal strength. All studies included in the meta-analysis met the following inclusion criteria: (1) peer-reviewed publication; (2) published in English; (3) comparison of a periodized resistance training group to a non-periodized resistance training group; (4) maximal strength measured by 1-repetition maximum (1RM) squat, bench press, or leg press. Data were extracted and independently coded by two authors. Random-effects models were used to aggregate a mean effect size (ES), 95% confidence intervals (CIs) and potential moderators. The cumulative results of 81 effects gathered from 18 studies published between 1988 and 2015 indicated that the magnitude of improvement in 1RM following periodized resistance training was greater than non-periodized resistance training (ES = 0.43, 95% CI 0.27-0.58; P training status (β = -0.59; P = 0.0305), study length (β = 0.03; P = 0.0067), and training frequency (β = 0.46; P = 0.0123) were associated with a change in 1RM. These results indicate that undulating programs were more favorable for strength gains. Improvements in 1RM were greater among untrained participants. Additionally, higher training frequency and longer study length were associated with larger improvements in 1RM. These results suggest that periodized resistance training plans have a moderate effect on 1RM compared to non-periodized training plans. Variation in training stimuli
PERIOD ESTIMATION FOR SPARSELY SAMPLED QUASI-PERIODIC LIGHT CURVES APPLIED TO MIRAS
Energy Technology Data Exchange (ETDEWEB)
He, Shiyuan; Huang, Jianhua Z.; Long, James [Department of Statistics, Texas A and M University, College Station, TX (United States); Yuan, Wenlong; Macri, Lucas M., E-mail: lmacri@tamu.edu [George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX (United States)
2016-12-01
We develop a nonlinear semi-parametric Gaussian process model to estimate periods of Miras with sparsely sampled light curves. The model uses a sinusoidal basis for the periodic variation and a Gaussian process for the stochastic changes. We use maximum likelihood to estimate the period and the parameters of the Gaussian process, while integrating out the effects of other nuisance parameters in the model with respect to a suitable prior distribution obtained from earlier studies. Since the likelihood is highly multimodal for period, we implement a hybrid method that applies the quasi-Newton algorithm for Gaussian process parameters and search the period/frequency parameter space over a dense grid. A large-scale, high-fidelity simulation is conducted to mimic the sampling quality of Mira light curves obtained by the M33 Synoptic Stellar Survey. The simulated data set is publicly available and can serve as a testbed for future evaluation of different period estimation methods. The semi-parametric model outperforms an existing algorithm on this simulated test data set as measured by period recovery rate and quality of the resulting period–luminosity relations.
Regenerated rat skeletal muscle after periodic contusions
Directory of Open Access Journals (Sweden)
V.B. Minamoto
2001-11-01
Full Text Available In the present study we evaluated the morphological aspect and changes in the area and incidence of muscle fiber types of long-term regenerated rat tibialis anterior (TA muscle previously submitted to periodic contusions. Animals received eight consecutive traumas: one trauma per week, for eight weeks, and were evaluated one (N = 8 and four (N = 9 months after the last contusion. Serial cross-sections were evaluated by toluidine blue staining, acid phosphatase and myosin ATPase reactions. The weight of injured muscles was decreased compared to the contralateral intact one (one month: 0.77 ± 0.15 vs 0.91 ± 0.09 g, P = 0.03; four months: 0.79 ± 0.14 vs 1.02 ± 0.07 g, P = 0.0007, respectively and showed abundant presence of split fibers and fibers with centralized nuclei, mainly in the deep portion. Damaged muscles presented a higher incidence of undifferentiated fibers when compared to the intact one (one month: 3.4 ± 2.1 vs 0.5 ± 0.3%, P = 0.006; four months: 2.3 ± 1.6 vs 0.3 ± 0.3%, P = 0.007, respectively. Injured TA evaluated one month later showed a decreased area of muscle fibers when compared to the intact one (P = 0.003. Thus, we conclude that: a muscle fibers were damaged mainly in the deep portion, probably because they were compressed against the tibia; b periodic contusions in the TA muscle did not change the percentage of type I and II muscle fibers; c periodically injured TA muscles took four months to reach a muscle fiber area similar to that of the intact muscle.
Heat waves and warm periods in Slovakia
Faško, Pavel; Bochníček, Oliver; Markovič, Ladislav; Švec, Marek
2016-04-01
The scenarios of climate change caused by human activity show that frequency of occurrence and extent of heat waves in the interior of Europe is increasing. Among the most exposed regions in this regard should the area of southeastern and eastern Austria and south-western Slovakia. The relatively faster increase in the number of heat waves in this area is related also to potential desertification in this region just east of the Alps, since during summer, weather fronts advancing from the west are consequently losing their original features and moderating influence. Summer weather patterns for this area should in the future more closely remind climate typical for some inland areas of southwestern, southern and southeastern Europe. A certain shift of climate zones from south to north should thus modify future climate and Slovakia. Despite the complex natural conditions the existing trends derived from results of meteorological measurements and observations are clear and they confirm warming of climate in this region. Observations and measurements in the recent years of the 21st century confirm, that heat waves are no longer rare phenomenon during summer, but are systematically appearing even in colder regions of northern Slovakia. What is very remarkable and will be necessary to pay more attention to, is the fact that these heat waves are expanding into previously unaffected areas, associated with the lack of rainfall and drought, on larger regional scale. In this study heat wave periods and individual heat events and days are statistically identified in the time series characteristics of air temperature at selected meteorological stations for the period from the mid-20th century until 2015, in case of available historical data even for longer period.
The eclipse period of Escherichia coli
DEFF Research Database (Denmark)
von Freiesleben, Ulrik; Krekling, Martin A.; Hansen, Flemming G.
2000-01-01
corresponds to the period of origin hemimethylation. The SeqA protein was absolutely required for the eclipse, and DnaA titration studies suggested that the SeqA protein prevented the binding of multiple DnaA molecules on oriC (initial complex formation). No correlation between the amount of SeqA and eclipse...... length was revealed, but increased SeqA levels affected chromosome partitioning and/or cell division. This was corroborated further by an aberrant nucleoid distribution in SeqA-deficient cells. We suggest that the SeqA protein's role in maintaining the eclipse is tied to a function in chromosome...
Romanian Economy in the Interwar Period
Directory of Open Access Journals (Sweden)
Gheorghe Stefan
2016-05-01
Full Text Available Resumption of economic progress Will Be slow, but unevenly but after overcoming the food crisis of 1920-1921, Romania will be able to deliver on economic recovery by attracting capital investment, Increase the number of enterprises and workers and especially by increasing the driving force and technical endowment of enterprises. The Central Authorities Legislation Will draw up related protectionist liberal economic doctrine “by ourselves” in most of the period, According to political algorithm and the result of Increasing domestic resource mobilization of capital while limiting the foreign capital in the Romanian economy.
Periodic gaits for the CMU Ambler
Dwivedi, Suren N.; Mahalingam, Swaminathan
1992-02-01
The configuration of the Carnegie-Mellon University Ambler, a six-legged autonomous walking vehicle for exploring Mars, enables the recovery of a trailing leg past the leading leg to reduce the energy expenditure in terrain interactions. In this article, gaits developed for this unprecedented configuration are described. A stability criterion has been developed that ensures stability of the vehicle in the event of failure of any one of the supporting legs. Periodic gaits developed for the Ambler utilize the Ambler's unique abilities and continuously satisfy the stability criterion.
Marginal elasticity of periodic triangulated origami
Chen, Bryan; Sussman, Dan; Lubensky, Tom; Santangelo, Chris
Origami, the classical art of folding paper, has inspired much recent work on assembling complex 3D structures from planar sheets. Origami, and more generally hinged structures with rigid panels, where all faces are triangles have special properties due to having a bulk balance of mechanical degrees of freedom and constraints. We study two families of periodic triangulated origami structures, one based on the Miura ori and one based on a kagome-like pattern due to Ron Resch. We point out the consequences of the balance of degrees of freedom and constraints for these ''metamaterial plates'' and show how the elasticity can be tuned by changing the unit cell geometry.
Chaplygin sleigh with periodically oscillating internal mass
Bizyaev, Ivan A.; Borisov, Alexey V.; Kuznetsov, Sergey P.
2017-09-01
We consider the movement of Chaplygin sleigh on a plane that is a solid body with imposed nonholonomic constraint, which excludes the possibility of motions transversal to the constraint element (“knife-edge”), and complement the model with an attached mass, periodically oscillating relatively to the main platform of the sleigh. Numerical simulations indicate the occurrence of either unrestricted acceleration of the sleigh, or motions with bounded velocities and momenta, depending on parameters. We note the presence of phenomena characteristic to nonholonomic systems with complex dynamics; in particular, attractors occur responsible for chaotic motions. In addition, quasiperiodic regimes take place similar to those observed in conservative nonlinear dynamics.
Periodical cicadas: A minimal automaton model
de O. Cardozo, Giovano; de A. M. M. Silvestre, Daniel; Colato, Alexandre
2007-08-01
The Magicicada spp. life cycles with its prime periods and highly synchronized emergence have defied reasonable scientific explanation since its discovery. During the last decade several models and explanations for this phenomenon appeared in the literature along with a great deal of discussion. Despite this considerable effort, there is no final conclusion about this long standing biological problem. Here, we construct a minimal automaton model without predation/parasitism which reproduces some of these aspects. Our results point towards competition between different strains with limited dispersal threshold as the main factor leading to the emergence of prime numbered life cycles.
Preparation of NPP Dukovany periodic safety review
International Nuclear Information System (INIS)
Dubsky, L.; Vymazal, P.
2004-01-01
Dukovany NPP in Czech Republic performs a periodic safety review for the second time after approximately 20 years of operation. The history of the Safety Report and its transformation into an internationally accepted form complying with IAEA standards is described. The deterministic and probabilistic assessment of the plant's safety-related design and state is applied to determine whether and to what extend the relevant protective goals are fulfilled by the existing plant design. A description of the step-by-step process is presented together with the creation of methods and criteria for PSR evaluation prepared by Nuclear Research Institute Rez
Periodic disruptions in the MT-1 tokamak
International Nuclear Information System (INIS)
Zoletnik, S.
1988-11-01
Disruptive instabilities are common phenomena in toroidal devices, especially in tokamaks. Three types can be distinguished: internal, minor and major disruptions. Periodic minor disruptions in the MT-1 tokamak were measured systematically with values of the limiter safety factor between 4 and 10. The density limit as a function of plasma current and horizontal displacement was investigated. Precursor oscillations always appear before the instability with increasing amplitude but can be observed at the density limit with quasi-stationary amplitude. Phase correlation between precursor oscillations were measured with Mirnov coils and x-ray detectors, and they show good agreement with a simple magnetic island model. (R.P.) 11 refs.; 6 figs
BOUND PERIODICAL HOLDINGS BATTELLE - NORTHWEST LIBRARY
Energy Technology Data Exchange (ETDEWEB)
None
1967-05-01
This report lists the bound periodicals in the Technical Library at the Pacific Northwest Laboratory, operated by Battelle Memorial Institute. It was prepared from a computer program and is arranged in two parts. Part one is an alphabetical list of journals by title; part two is an arrangement of the journals by subject. The list headings are self-explanatory, with the exception of the title code, which is necessary in the machine processing. The listing is complete through June, 1966 and updates an earlier publication issued in March, 1965.
Plasmonic energy transfer in periodically doped graphene
International Nuclear Information System (INIS)
Silveiro, I; Manjavacas, A; Thongrattanasiri, S; García de Abajo, F J
2013-01-01
We predict unprecedentedly large values of the energy-transfer rate between an optical emitter and a layer of periodically doped graphene. The transfer exhibits divergences at photon frequencies corresponding to the Van Hove singularities of the plasmonic band structure of the graphene. In particular, we find flat bands associated with regions of vanishing doping charge, which appear in graphene when it is patterned through gates of spatially alternating signs, giving rise to intense transfer rate singularities. Graphene is thus shown to provide a unique platform for fast control of optical energy transfer via fast electrostatic inhomogeneous doping. (paper)
Periodate oxidation of nanoscaled magnetic dextran composites
International Nuclear Information System (INIS)
Hong Xia; Guo Wei; Yuan Hang; Li Jun; Liu Yanmei; Ma Lan; Bai Yubai; Li Tiejin
2004-01-01
Highly hydrophilic, uniform and nontoxic magnetic fluids consisting of magnetite (Fe 3 O 4 ) and dextran were prepared. A periodate oxidation method was used to further activate the magnetic dextran, forming magnetic polyaldehyde-dextran, which could be conjugated to biomolecules such as proteins or antibodies. Oxidated Magnetic dextran composites were characterized by TEM, XRD and SQUID magnetometry. Moreover, a flexible, rapid and simple method to detect aldehydes was introduced to the magnetic composite system by utilizing 2,4-dinitrophenylhydrazine reagent. The result of the quantitative analysis of aldehyde was given by thermogravimetric analysis and elemental analysis
Diffuse scattering from periodic and aperiodic crystals
International Nuclear Information System (INIS)
Frey, F.
1997-01-01
A (selective) review on diffuse scattering from periodic and aperiodic crystalline solids is given to demonstrate the wide field of applications in basic and applied research. After a general introduction in this field each topic is exemplified by one or two examples. Main emphasis is laid on recent work. More established work, e.g., on diffuse scattering from metals and alloys, polytypes, stacking disorder from layered structures, etc. is omitted due to the availability of excellent textbooks and reviews. Finally a short summary of recent developments of experimental methods and evaluation techniques is presented. (orig.)
Polaritons in periodic and quasiperiodic structures
Albuquerque, Eudenilson L
2004-01-01
In recent years there have been exciting developments in techniques for producing multilayered structures of different materials, often with thicknesses as small as only a few atomic layers. These artificial structures, known as superlattices, can either be grown with the layers stacked in an alternating fashion (the periodic case) or according to some other well-defined mathematical rule (the quasiperiodic case). This book describes research on the excitations (or wave-like behavior) of these materials, with emphasis on how the material properties are coupled to photons (the quanta of the l
Multiscale periodic structure in the Io wake
Energy Technology Data Exchange (ETDEWEB)
Smith, P R; Wright, A N
1989-06-08
The decametric radio emissions from Jupiter are known to be influenced by the Galilean satellite Io. It is believed that the structure in these emissions is associated with the Alfven-wave wake downstream of Io. However, recent studies have shown that the structure of the wake cannot be as simple as originally thought. Here we present preliminary results from an eigenmode synthesis of the Alfven waves launched by Io, and find that several important periodicities emerge. Observations of the decametric emissions reveal fine, medium-and large-scale structure. The simulation we present here can provide structure on each of these scales, unlike earlier models. (author).
Centroid motion in periodically focused beams
International Nuclear Information System (INIS)
Moraes, J.S.; Pakter, R.; Rizzato, F.B.
2005-01-01
The role of the centroid dynamics in the transport of periodically focused particle beams is investigated. A Kapchinskij-Vladimirskij equilibrium distribution for an off-axis beam is derived. It is shown that centroid and envelope dynamics are uncoupled and that unstable regions for the centroid dynamics overlap with previously stable regions for the envelope dynamics alone. Multiparticle simulations validate the findings. The effects of a conducting pipe encapsulating the beam are also investigated. It is shown that the charge induced at the pipe may generate chaotic orbits which can be detrimental to the adequate functioning of the transport mechanism
Jin, Wa; Bi, Wei-hong; Fu, Xing-hu; Fu, Guang-wei
2017-09-01
We report periodical rocking long period gratings (PR-LPGs) in PANDA fibers fabricated with CO2 laser. The PR-LPGs achieve very high coupling efficiency of 19 dB with 12 periods and a 3.5° twist angle in just one scanning cycle, which is much more effective than the conventional CO2 laser fabrication technique. This type of LPGs exhibits polarization-selective resonance dips which demonstrate different sensitivities to environmental parameters. The high temperature and external refractive index sensitivities are measured simultaneously, so it can be used as a wavelength-selective polarization filter and sensor.
[Studies on flomoxef in the perinatal period].
Cho, N; Fukunaga, K; Kunii, K; Kobayashi, I
1991-06-01
Pharmacokinetic, bacteriological and clinical studies on flomoxef (FMOX) in the perinatal period were carried out with the following summary of the results. Antibacterial effects of FMOX on the growth of methicillin-resistant Staphylococcus aureus (MRSA, MIC 400 micrograms/ml), methicillin-sensitive S. aureus (MSSA, MIC 0.78 microgram/ml), Escherichia coli (MIC 3.13 micrograms/ml and MIC 0.20 microgram/ml) in amniotic fluid were determined and it was found that the activity of FMOX was enhanced in the amniotic fluid. FMOX rapidly penetrated into tissues and sera of pregnant women upon intravenous injection and its maternal serum concentrations reached their peak levels shortly after administration. Placental penetration of FMOX to the fetus was good and, after single intravenous injection of 1 g, the concentrations of FMOX in the umbilical cord serum and amniotic fluid exceeded MICs against major causative organisms of perinatal infections. These results indicate that single intravenous injection of FMOX 1 g twice a day is effective for the treatment and prophylaxis of perinatal infections. Injection of FMOX for the treatment of 14 cases of puerperal infections showed excellent clinical effectiveness with 100% clinical effect and 81.8% bacteriological response. No side-effect was observed in any case. All of these results suggested clinical usefulness of FMOX in the perinatal period.
Spatially variant periodic structures in electromagnetics
Rumpf, Raymond C.; Pazos, Javier J.; Digaum, Jennefir L.; Kuebler, Stephen M.
2015-01-01
Spatial transforms are a popular technique for designing periodic structures that are macroscopically inhomogeneous. The structures are often required to be anisotropic, provide a magnetic response, and to have extreme values for the constitutive parameters in Maxwell's equations. Metamaterials and photonic crystals are capable of providing these, although sometimes only approximately. The problem still remains about how to generate the geometry of the final lattice when it is functionally graded, or spatially varied. This paper describes a simple numerical technique to spatially vary any periodic structure while minimizing deformations to the unit cells that would weaken or destroy the electromagnetic properties. New developments in this algorithm are disclosed that increase efficiency, improve the quality of the lattices and provide the ability to design aplanatic metasurfaces. The ability to spatially vary a lattice in this manner enables new design paradigms that are not possible using spatial transforms, three of which are discussed here. First, spatially variant self-collimating photonic crystals are shown to flow unguided waves around very tight bends using ordinary materials with low refractive index. Second, multi-mode waveguides in spatially variant band gap materials are shown to guide waves around bends without mixing power between the modes. Third, spatially variant anisotropic materials are shown to sculpt the near-field around electric components. This can be used to improve electromagnetic compatibility between components in close proximity. PMID:26217058