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1

Direct Search Methods on Parallel Machines 28 ment of Mathematical Sciences, Rice University, Houston, Texas 772511892.  

E-print Network

Direct Search Methods on Parallel Machines 28 ment of Mathematical Sciences, Rice University, Mathematical Program­ ming, 42 (1988), pp. 273--306. [5] J. E. Dennis, Jr., D. M. Gay, and R. E. Welsch.O. Box 109, College Lane, Hatfield, Hertfordshire AL10 9AB, U.K., 1981. [7] R. Fletcher and M. J. D

Torczon, Virginia

2

Parallel text search methods  

Microsoft Academic Search

A comparison of recently proposed parallel text search methods to alternative available search strategies that use serial processing machines suggests parallel methods do not provide large-scale gains in either retrieval effectiveness or efficiency.

Gerard Salton; Chris Buckley

1988-01-01

3

ASYNCHRONOUS PARALLEL PATTERN SEARCH FOR NONLINEAR OPTIMIZATION  

E-print Network

ASYNCHRONOUS PARALLEL PATTERN SEARCH FOR NONLINEAR OPTIMIZATION PATRICIA D. HOUGH, TAMARA G. KOLDA. 1, pp. 134­156 Abstract. We introduce a new asynchronous parallel pattern search (APPS). Parallel pattern search can be quite useful for engineering optimization problems characterized by a small number

Kolda, Tamara G.

4

ASYNCHRONOUS PARALLEL PATTERN SEARCH FOR NONLINEAR OPTIMIZATION #  

E-print Network

ASYNCHRONOUS PARALLEL PATTERN SEARCH FOR NONLINEAR OPTIMIZATION # PATRICIA D. HOUGH + , TAMARA G Mathematics Vol. 23, No. 1, pp. 134--156 Abstract. We introduce a new asynchronous parallel pattern search (APPS). Parallel pattern search can be quite useful for engineering optimization problems characterized

Kolda, Tamara G.

5

Exploiting CPU Bit Parallel Operations to Improve Efficiency in Search  

Microsoft Academic Search

It is the authors' belief that the ability of processors to compute bit parallel operations should have a right to exist as an optimization discipline, rather than a state-of- the-art technique. This paper is a step forward in this direction analysing a number of key issues related to bit model design and implementation of search problems. Building efficient search algorithms

Pablo San Segundo; Diego Rodrguez-Losada; Ramn Galn; Fernando Mata; Agustn Jimnez

2007-01-01

6

PARALLEL GREEDY RANDOMIZED ADAPTIVE SEARCH ...  

E-print Network

Dec 6, 2004 ... ing the search space or partitioning the GRASP iterations and assigning each partition to a .... for the data to estimate the parameters of the two-parameter exponential distribution. To ..... For each problem, we first state the problem and describe ...... IEEE Transactions on Power Systems, 20(1), 2005.

2004-12-06

7

Asynchronous parallel pattern search for nonlinear optimization  

SciTech Connect

Parallel pattern search (PPS) can be quite useful for engineering optimization problems characterized by a small number of variables (say 10--50) and by expensive objective function evaluations such as complex simulations that take from minutes to hours to run. However, PPS, which was originally designed for execution on homogeneous and tightly-coupled parallel machine, is not well suited to the more heterogeneous, loosely-coupled, and even fault-prone parallel systems available today. Specifically, PPS is hindered by synchronization penalties and cannot recover in the event of a failure. The authors introduce a new asynchronous and fault tolerant parallel pattern search (AAPS) method and demonstrate its effectiveness on both simple test problems as well as some engineering optimization problems

P. D. Hough; T. G. Kolda; V. J. Torczon

2000-01-01

8

HOPSPACK: Hybrid Optimization Parallel Search Package.  

SciTech Connect

In this paper, we describe the technical details of HOPSPACK (Hybrid Optimization Parallel SearchPackage), a new software platform which facilitates combining multiple optimization routines into asingle, tightly-coupled, hybrid algorithm that supports parallel function evaluations. The frameworkis designed such that existing optimization source code can be easily incorporated with minimalcode modification. By maintaining the integrity of each individual solver, the strengths and codesophistication of the original optimization package are retained and exploited.4

Gray, Genetha A.; Kolda, Tamara G.; Griffin, Joshua; Taddy, Matt; Martinez-Canales, Monica

2008-12-01

9

Parallel Mechanisms for Visual Search in Zebrafish  

PubMed Central

Parallel visual search mechanisms have been reported previously only in mammals and birds, and not animals lacking an expanded telencephalon such as bees. Here we report the first evidence for parallel visual search in fish using a choice task where the fish had to find a target amongst an increasing number of distractors. Following two-choice discrimination training, zebrafish were presented with the original stimulus within an increasing array of distractor stimuli. We found that zebrafish exhibit no significant change in accuracy and approach latency as the number of distractors increased, providing evidence of parallel processing. This evidence challenges theories of vertebrate neural architecture and the importance of an expanded telencephalon for the evolution of executive function. PMID:25353168

Proulx, Michael J.; Parker, Matthew O.; Tahir, Yasser; Brennan, Caroline H.

2014-01-01

10

Parallel mechanisms for visual search in zebrafish.  

PubMed

Parallel visual search mechanisms have been reported previously only in mammals and birds, and not animals lacking an expanded telencephalon such as bees. Here we report the first evidence for parallel visual search in fish using a choice task where the fish had to find a target amongst an increasing number of distractors. Following two-choice discrimination training, zebrafish were presented with the original stimulus within an increasing array of distractor stimuli. We found that zebrafish exhibit no significant change in accuracy and approach latency as the number of distractors increased, providing evidence of parallel processing. This evidence challenges theories of vertebrate neural architecture and the importance of an expanded telencephalon for the evolution of executive function. PMID:25353168

Proulx, Michael J; Parker, Matthew O; Tahir, Yasser; Brennan, Caroline H

2014-01-01

11

Toward a Taxonomy of Parallel Tabu Search Heuristics  

Microsoft Academic Search

In this paper we present a classification of parallel tabu search metaheuristicsbased, on the one hand, on the control and communication strategies used in thedesign of the parallel tabu search procedures and, on the other hand, on how the searchspace is partitionned. These criteria are then used to review the parallel tabu searchimplementations described in the literature. The taxonomy is

Teodor Gabriel Crainic; Michel Toulouse; Michel Gendreau

1997-01-01

12

Algorithm 856: APPSPACK 4.0: Asynchronous Parallel Pattern Search  

E-print Network

Algorithm 856: APPSPACK 4.0: Asynchronous Parallel Pattern Search for Derivative-Free Optimization unconstrained and bound-constrained optimization problems. It implements an asynchronous parallel pattern search-free optimization, pattern search 1. INTRODUCTION APPSPACK is software for solving unconstrained and bound

Kolda, Tamara G.

13

ON THE CONVERGENCE OF ASYNCHRONOUS PARALLEL PATTERN SEARCH  

E-print Network

ON THE CONVERGENCE OF ASYNCHRONOUS PARALLEL PATTERN SEARCH TAMARA G. KOLDA AND VIRGINIA J. TORCZON­964 Abstract. In this paper we prove global convergence for asynchronous parallel pattern search. In standard pattern search, decisions regarding the update of the iterate and the step-length control parameter

Kolda, Tamara G.

14

Parallel Monte-Carlo Tree Search with Simulation Servers  

Microsoft Academic Search

Monte-Carlo tree search is a new best-first tree search algorithm that triggered a revolution in the computer Go world. Developing good parallel Monte-Carlo tree search algorithms is importan because single processor's performance cannot be expected to increase as used to. A novel parallel Monte-Carlo tree search algorithm is proposed. A tree searcher runs on a client computer and multiple Monte-Carlo

Hideki Kato; Ikuo Takeuchi

2010-01-01

15

Generalized quantum search with parallelism Robert M. Gingrich,1  

E-print Network

computing. In tandem with these hardware developments, there has been a parallel development of new quantum that a hybrid use of quantum computing and classical computing techniques can yield a performance that is better that connects the degree of parallelism with the expected computation time for k-parallel quantum search

Cerf, Nicolas

16

Parallel Support Set Searches for Meshfree Methods  

Microsoft Academic Search

Abstract. We describe the implementation of a parallel algorithm which solves a computational geometry problem arising in meshfree methods. We solve the following problem: Given a collection of N d-rectangles Si and P points xk in R,-trees (for example, octrees for the case d = 3). Parallel issues of load balancing and characteristics of the collections of sets and points

C. Cartwright; Suely Oliveira; David E. Stewart

2006-01-01

17

Direct search for dark matter  

SciTech Connect

Dark matter is hypothetical matter which does not interact with electromagnetic radiation. The existence of dark matter is only inferred from gravitational effects of astrophysical observations to explain the missing mass component of the Universe. Weakly Interacting Massive Particles are currently the most popular candidate to explain the missing mass component. I review the current status of experimental searches of dark matter through direct detection using terrestrial detectors.

Yoo, Jonghee; /Fermilab

2009-12-01

18

Parallel and Serial Processes in Visual Search  

ERIC Educational Resources Information Center

A long-standing issue in the study of how people acquire visual information centers around the scheduling and deployment of attentional resources: Is the process serial, or is it parallel? A substantial empirical effort has been dedicated to resolving this issue. However, the results remain largely inconclusive because the methodologies that have

Thornton, Thomas L.; Gilden, David L.

2007-01-01

19

Parallel high-throughput limited search trellis decoder VLSI design  

Microsoft Academic Search

Limited search trellis decoding algorithms have great potentials of realizing low power due to their largely reduced computational complexity compared with the widely used Viterbi algorithm. However, because of the lack of operational parallelism and regularity in their original formulations, the limited search decoding algorithms have been traditionally ruled out for applications demanding very high throughput. We believe that, through

Fei Sun; Tong Zhang

2005-01-01

20

Parallel visual search and rapid animal detection in natural scenes  

E-print Network

Parallel visual search and rapid animal detection in natural scenes Centre de Recherche Cerveau et, Giessen, GermanyKarl R. Gegenfurtner Human observers are capable of detecting animals within novel natural and efficient even when the animals are embedded in their natural backgrounds. Keywords: visual search, rapid

21

Ethan Burns (UNH) Abstraction in Multicore Heuristic Search 1 / 31 Parallel Best-First Search: The Role of Abstraction  

E-print Network

Ethan Burns (UNH) Abstraction in Multicore Heuristic Search ­ 1 / 31 Parallel Best-First Search: The Role of Abstraction Ethan Burns1, Sofia Lemons1, Wheeler Ruml1 and Rong Zhou2 1 2 [Many thanks to NSF s Best-first Search s Parallel Search PRA* PBNF Optimal Search Suboptimal Search Conclusion Ethan Burns

Ruml, Wheeler

22

Parallel programming with message passing and directives  

Microsoft Academic Search

The authors discuss methods for expressing and tuning the performance of parallel programs, using two programming models in the same program: distributed and shared memory. Such methods are important for anyone who uses these large machines for parallel programs as well as for those who study combinations of the two programming models. The article outlines applications in hydrology, computational chemistry,

S. W. Bova; C. P. Breshears; HENRY GABB; BOB KUHN; BILL MAGRO; RUDOLF EIGENMANN; GREG GAERTNER; STEFANO SALVINI; HOWARD SCOTT

2001-01-01

23

AGLSDC: A Genetic Local Search Suitable for Parallel Computation  

NASA Astrophysics Data System (ADS)

Because evolutionary algorithms (EAs) generally require many repeated evaluations of objective functions, it often takes considerable time to solve optimization problems. Parallel computation is one means to shorten the required computation time. In earlier works, the authors proposed an EA suitable for coarse-grained parallel computers, a genetic local search with distance independent diversity control (GLSDC). Though GLSDC has been applied successfully to several practical problems, its parallel efficiency abruptly drops off as the number of CPUs for computation increases. To achieve a higher parallel efficiency, the authors now propose a new EA, an asynchronous GLSDC (AGLSDC), constructed by reworking the algorithm of GLSDC. This paper introduces the proposed method and reports verification of the method through numerical experiments on several benchmark problems and a practical problem.

Kimura, Shuhei; Nakakuki, Takashi; Kirita, Seiji; Okada, Mariko

24

Direct search for WIMP dark matter  

E-print Network

We will review the experimental aspects of the direct search for WIMP dark matter. In thin search, one looks in a terrestrial target for nuclear recoils produced by the impacts with WIMPs from the galatic halo. After describing the different search strategies and review the currently running experiments and the prospects of future experiments

J. Gascon

2005-04-11

25

Ethane: A Heterogeneous Parallel Search Algorithm for Heterogeneous Platforms  

E-print Network

In this paper we present Ethane, a parallel search algorithm specifically designed for its execution on heterogeneous hardware environments. With Ethane we propose an algorithm inspired in the structure of the chemical compound of the same name, implementing a heterogeneous island model based in the structure of its chemical bonds. We also propose a schema for describing a family of parallel heterogeneous metaheuristics inspired by the structure of hydrocarbons in Nature, HydroCM (HydroCarbon inspired Metaheuristics), establishing a resem- blance between atoms and computers, and between chemical bonds and communication links. Our goal is to gracefully match computers of different power to algorithms of different behavior (GA and SA in this study), all them collaborating to solve the same problem. The analysis will show that Ethane, though simple, can solve search problems in a faster and more robust way than well-known panmitic and distributed algorithms very popular in the literature.

Domnguez, Julin

2011-01-01

26

Dark Matter Search with Direction Sensitive Scintillators  

E-print Network

We have carried out the dark matter search with a 116g direction-sensitive stilbene crystal in Kamioka Observatory. With the crystal fixed to the earth, we searched the modulation of thelight output. No modulation signal was found due to the small size of the detector crystal and the higher background rate yet to be eliminated. However, it demonstrated the effectiveness of the method of direction sensitive search for the dark matter with an implementation of the anisotropic organic scintillation crystal.

H. Sekiya; M. Mionwa; Y. Shimizu; W. Suganuma; Y. Inoue

2004-11-09

27

Efficient sequential and parallel algorithms for planted motif search  

PubMed Central

Background Motif searching is an important step in the detection of rare events occurring in a set of DNA or protein sequences. One formulation of the problem is known as (l,d)-motif search or Planted Motif Search (PMS). In PMS we are given two integers l and d and n biological sequences. We want to find all sequences of length l that appear in each of the input sequences with at most d mismatches. The PMS problem is NP-complete. PMS algorithms are typically evaluated on certain instances considered challenging. Despite ample research in the area, a considerable performance gap exists because many state of the art algorithms have large runtimes even for moderately challenging instances. Results This paper presents a fast exact parallel PMS algorithm called PMS8. PMS8 is the first algorithm to solve the challenging (l,d) instances (25,10) and (26,11). PMS8 is also efficient on instances with larger l and d such as (50,21). We include a comparison of PMS8 with several state of the art algorithms on multiple problem instances. This paper also presents necessary and sufficient conditions for 3 l-mers to have a common d-neighbor. The program is freely available at http://engr.uconn.edu/~man09004/PMS8/. Conclusions We present PMS8, an efficient exact algorithm for Planted Motif Search. PMS8 introduces novel ideas for generating common neighborhoods. We have also implemented a parallel version for this algorithm. PMS8 can solve instances not solved by any previous algorithms. PMID:24479443

2014-01-01

28

Parallel processing of shape and texture in haptic search.  

PubMed

In a haptic search task, one has to determine the presence of a target among distractors. It has been shown that if the target differs from the distractors in two properties, shape and texture, performance is better than in both single-property conditions (Van Polanen, Bergmann Tiest, & Kappers, 2013). The search for a smooth sphere among rough cubical distractors was faster than both the searches for a rough sphere (shape information only) and for a smooth cube (texture information only). This effect was replicated in this study as a baseline. The main focus here was to further investigate the nature of this integration. It was shown that performance is better when the two properties are combined in a single target (smooth sphere), than when located in two separate targets (rough sphere and smooth cube) that are simultaneously present. A race model that assumes independent parallel processing of the two properties could explain the enhanced performance with two properties, but this could only take place effectively when the two properties were located in a single target. PMID:24816269

van Polanen, Vonne; Bergmann Tiest, Wouter M; Kappers, Astrid M L

2014-07-01

29

Search Direction Made Evolution Strategies Faster  

NASA Astrophysics Data System (ADS)

Genetic operators are primarily search operators in Evolution Strategies (ES). In fact, there are two important issues in the evolution process of the genetic search: exploration and exploitation. The analysis of the impact of the genetic operators in ES shows that the Classical Evolution Strategies (CES) relies on Gaussian mutation, whereas Fast Evolution Strategies (FES) selects Cauchy distribution as the primary mutation operator. With the analysis of the basic genetic operators of ES as well as their performances on a number of benchmark problems, this paper proposes an Improved Fast ES (IFES) which applies the search direction of global optimization into mutation operation to guide evolution process convergence, thus making the process quicker.

Lin, Guangming; Lu, Xin; Kang, Lishan

30

Exact Quantum Search by Parallel Unitary Discrimination Schemes  

E-print Network

We study the unsorted database search problem with items $N$ from the viewpoint of unitary discrimination. Instead of considering the famous $O(\\sqrt{N})$ Grover's the bounded-error algorithm for the original problem, we seek for the results about the exact algorithms, i.e. the ones succeed with certainty. Under the standard oracle model $\\sum_j (-1)^{\\delta_{\\tau j}}|j>< j|$, we demonstrate a tight lower bound ${2/3}N+o(N)$ of the number of queries for any parallel scheme with unentangled input states. With the assistance of entanglement, we obtain a general lower bound ${1/2}(N-\\sqrt{N})$. We provide concrete examples to illustrate our results. In particular, we show that the case of N=6 can be solved exactly with only two queries by using a bipartite entangled input state. Our results indicate that in the standard oracle model the complexity of exact quantum search with one unique solution can be strictly less than that of the calculation of OR function.

Xiaodi Wu; Runyao Duan

2007-09-23

31

DIRECT POLICY SEARCH AND UNCERTAIN POLICY EVALUATION  

Microsoft Academic Search

Reinforcement learning based on direct search in policy space requires few assumptions about the environment. Hence it is applicable in certain situations where most traditional reinforcement learning algorithms based on dynamic programming are not, especially in partially observable, deterministic worlds. In realistic settings, however, reliable policy evaluations are complicated by numerous sources of uncertainty, such as stochasticity in policy and

Jiirgen Schmidhuber; Jieyu Zhao

1998-01-01

32

Exploiting Parallelism to Accelerate Keyword Search on Deep-Web Sources  

Microsoft Academic Search

Increasingly, biological data is being shared over the deep web. Many biological queries can only be answered by successively search- ing a number of distinct web-sites. This paper introduces a system that exploits parallelization for accelerating search over multiple deep web data sources. An interactive, two-stage multi-threading system is devel- oped to achieve task parallelization, thread parallelization, and pipelined parallelization.

Tantan Liu; Fan Wang; Gagan Agrawal

2009-01-01

33

Efficient Parallel Algorithm For Direct Numerical Simulation of Turbulent Flows  

NASA Technical Reports Server (NTRS)

A distributed algorithm for a high-order-accurate finite-difference approach to the direct numerical simulation (DNS) of transition and turbulence in compressible flows is described. This work has two major objectives. The first objective is to demonstrate that parallel and distributed-memory machines can be successfully and efficiently used to solve computationally intensive and input/output intensive algorithms of the DNS class. The second objective is to show that the computational complexity involved in solving the tridiagonal systems inherent in the DNS algorithm can be reduced by algorithm innovations that obviate the need to use a parallelized tridiagonal solver.

Moitra, Stuti; Gatski, Thomas B.

1997-01-01

34

Direct parallel perceptrons (DPPs): fast analytical calculation of the parallel perceptrons weights with margin control for classification tasks.  

PubMed

Parallel perceptrons (PPs) are very simple and efficient committee machines (a single layer of perceptrons with threshold activation functions and binary outputs, and a majority voting decision scheme), which nevertheless behave as universal approximators. The parallel delta (P-Delta) rule is an effective training algorithm, which, following the ideas of statistical learning theory used by the support vector machine (SVM), raises its generalization ability by maximizing the difference between the perceptron activations for the training patterns and the activation threshold (which corresponds to the separating hyperplane). In this paper, we propose an analytical closed-form expression to calculate the PPs' weights for classification tasks. Our method, called Direct Parallel Perceptrons (DPPs), directly calculates (without iterations) the weights using the training patterns and their desired outputs, without any search or numeric function optimization. The calculated weights globally minimize an error function which simultaneously takes into account the training error and the classification margin. Given its analytical and noniterative nature, DPPs are computationally much more efficient than other related approaches (P-Delta and SVM), and its computational complexity is linear in the input dimensionality. Therefore, DPPs are very appealing, in terms of time complexity and memory consumption, and are very easy to use for high-dimensional classification tasks. On real benchmark datasets with two and multiple classes, DPPs are competitive with SVM and other approaches but they also allow online learning and, as opposed to most of them, have no tunable parameters. PMID:21984498

Fernandez-Delgado, Manuel; Ribeiro, Jorge; Cernadas, Eva; Ameneiro, Senn Barro

2011-11-01

35

Exploiting Parallelism to Accelerate Keyword Search On Deep-web Sources  

E-print Network

Exploiting Parallelism to Accelerate Keyword Search On Deep-web Sources Tantan Liu Fan Wang Gagan,wangfa,agrawal}@cse.ohio-state.edu Abstract. Increasingly, biological data is being shared over the deep web. Many biological queries can only that exploits parallelization for accelerating search over multiple deep web data sources. An interactive, two

Agrawal, Gagan

36

Searching for Brown Dwarfs and Extreme M Dwarfs in STIS Parallel Observations  

Microsoft Academic Search

We propose to use STIS parallel images and spectra to search for extremely late M dwarfs and brown dwarfs. Data already available show that many STIS parallel fields contain candidate stars and that spectral classification of these stars is possible. We estimate that there will be 50 late dwarfs detected in the parallels by the end of the grant period.

Philip Plait

1997-01-01

37

EDELWEISS experiment: Direct search for dark matter  

SciTech Connect

The EDELWEISS experiment is aimed at direct searches for nonbaryonic cold dark matter by means of cryogenic germanium detectors. It is deployed at the LSM underground laboratory in the Frejus tunnel, which connects France and Italy. The results of the experimentmade it possible to set a limit on the spin-independent cross section for the scattering of weak-interacting massive particles (WIMP) at a level of 10{sup -6} pb. Data from 21 detectors of total mass about 7 kg are being accumulated at the present time.

Lubashevskiy, A. V., E-mail: alexey.lubashevsky@jinr.ru; Yakushev, E. A. [Joint Institute for Nuclear Research (Russian Federation)

2008-07-15

38

Fencing direct memory access data transfers in a parallel active messaging interface of a parallel computer  

DOEpatents

Fencing direct memory access (`DMA`) data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including specifications of a client, a context, and a task, the endpoints coupled for data communications through the PAMI and through DMA controllers operatively coupled to segments of shared random access memory through which the DMA controllers deliver data communications deterministically, including initiating execution through the PAMI of an ordered sequence of active DMA instructions for DMA data transfers between two endpoints, effecting deterministic DMA data transfers through a DMA controller and a segment of shared memory; and executing through the PAMI, with no FENCE accounting for DMA data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all DMA instructions initiated prior to execution of the FENCE instruction for DMA data transfers between the two endpoints.

Blocksome, Michael A.; Mamidala, Amith R.

2013-09-03

39

The perfect search engine is not enough: a study of orienteering behavior in directed search  

Microsoft Academic Search

This paper presents a modified diary study that investigated how people performed personally motivated searches in their email, in their files, and on the Web. Although earlier studies of directed search focused on keyword search, most of the search behavior we observed did not involve keyword search. Instead of jumping directly to their information target using keywords, our participants navigated

Jaime Teevan; Christine Alvarado; Mark S. Ackerman; David R. Karger

2004-01-01

40

Nonlinearly-constrained optimization using asynchronous parallel generating set search.  

SciTech Connect

Many optimization problems in computational science and engineering (CS&E) are characterized by expensive objective and/or constraint function evaluations paired with a lack of derivative information. Direct search methods such as generating set search (GSS) are well understood and efficient for derivative-free optimization of unconstrained and linearly-constrained problems. This paper addresses the more difficult problem of general nonlinear programming where derivatives for objective or constraint functions are unavailable, which is the case for many CS&E applications. We focus on penalty methods that use GSS to solve the linearly-constrained problems, comparing different penalty functions. A classical choice for penalizing constraint violations is {ell}{sub 2}{sup 2}, the squared {ell}{sub 2} norm, which has advantages for derivative-based optimization methods. In our numerical tests, however, we show that exact penalty functions based on the {ell}{sub 1}, {ell}{sub 2}, and {ell}{sub {infinity}} norms converge to good approximate solutions more quickly and thus are attractive alternatives. Unfortunately, exact penalty functions are discontinuous and consequently introduce theoretical problems that degrade the final solution accuracy, so we also consider smoothed variants. Smoothed-exact penalty functions are theoretically attractive because they retain the differentiability of the original problem. Numerically, they are a compromise between exact and {ell}{sub 2}{sup 2}, i.e., they converge to a good solution somewhat quickly without sacrificing much solution accuracy. Moreover, the smoothing is parameterized and can potentially be adjusted to balance the two considerations. Since many CS&E optimization problems are characterized by expensive function evaluations, reducing the number of function evaluations is paramount, and the results of this paper show that exact and smoothed-exact penalty functions are well-suited to this task.

Griffin, Joshua D.; Kolda, Tamara Gibson

2007-05-01

41

A directed search for extraterrestrial laser signals  

NASA Technical Reports Server (NTRS)

The focus of NASA's Search for Extraterrestrial Intelligence (SETI) Program is on microwave frequencies, where receivers have the best sensitivities for the detection of narrowband signals. Such receivers, when coupled to existing radio telescopes, form an optimal system for broad area searches over the sky. For a directed search, however, such as toward specific stars, calculations show that infrared wavelengths can be equally as effective as radio wavelengths for establishing an interstellar communication link. This is true because infrared telescopes have higher directivities (gains) that effectively compensate for the lower sensitivities of infrared receivers. The result is that, for a given level of transmitted power, the signal to noise ratio for communications is equally as good at infrared and radio wavelengths. It should also be noted that the overall sensitivities of both receiver systems are quite close to their respective fundamental limits: background thermal noise for the radio frequency system and quantum noise for the infrared receiver. Consequently, the choice of an optimum communication frequency may well be determined more by the achievable power levels of transmitters rather than the ultimate sensitivities of receivers at any specific frequency. In the infrared, CO2 laser transmitters with power levels greater than 1 MW can already be built on Earth. For a slightly more advanced civilization, a similar but enormously more powerful laser may be possible using a planetary atmosphere rich in CO2. Because of these possibilities and our own ignorance of what is really the optimum search frequency, a search for narrowband signals at infrared frequencies should be a part of a balanced SETI Program. Detection of narrowband infrared signals is best done with a heterodyne receiver functionally identical to a microwave spectral line receiver. We have built such a receiver for the detection of CO2 laser radiation at wavelengths near 10 microns. The spectrometer uses a high-speed HgCdTe diode as the photomixer and a small CO2 laser as the local oscillator. Output signals in the intermediate frequency range 0.1-2.6 GHz are processed by a 1000-channel acousto-optic signal processor. The receiver is being used on a 1.5-m telescope on Mt. Wilson to survey a selected sample of 150 nearby stars. The current status of the work is discussed along with future project plans.

Betz, A.

1991-01-01

42

Direct drive digital servo press with high parallel control  

NASA Astrophysics Data System (ADS)

Direct drive digital servo press has been developed as the university-industry joint research and development since 1998. On the basis of this result, 4-axes direct drive digital servo press has been developed and in the market on April of 2002. This servo press is composed of 1 slide supported by 4 ball screws and each axis has linearscale measuring the position of each axis with high accuracy less than ?m order level. Each axis is controlled independently by servo motor and feedback system. This system can keep high level parallelism and high accuracy even with high eccentric load. Furthermore the 'full stroke full power' is obtained by using ball screws. Using these features, new various types of press forming and stamping have been obtained by development and production. The new stamping and forming methods are introduced and 'manufacturing' need strategy of press forming with high added value and also the future direction of press forming are also introduced.

Murata, Chikara; Yabe, Jun; Endou, Junichi; Hasegawa, Kiyoshi

2013-12-01

43

Direct binary search (DBS) algorithm with constraints  

NASA Astrophysics Data System (ADS)

In this paper, we describe adding constraints to the Direct Binary Search (DBS) algorithm. An example of a useful constraint, illustrated in this paper, is having only one dot per column and row. DBS with such constraints requires greater than two toggles during each trial operation. Implementations of the DBS algorithm traditionally limit operations to either one toggle or swap during each trial. The example case in this paper produces a wrap-around pattern with uniformly distributed ON pixels which will have a pleasing appearance with precisely one ON pixel per each column and row. The algorithm starts with an initial continuous tone image and an initial pattern having only one ON pixel per column and row. The auto correlation function of Human Visual System (HVS) model is determined along with an initial perceived error. Multiple operation pixel error processing during each iteration is used to enforce the one ON pixel per column and row constraint. The constraint of a single ON pixel per column and row is used as an example in this paper. Further modification of the DBS algorithm for other constraints is possible, based on the details given in the paper. A mathematical framework to extend the algorithm to the more general case of Direct Multi-bit Search (DMS) is presented.

Chandu, Kartheek; Stanich, Mikel; Wu, Chai Wah; Trager, Barry

2013-02-01

44

Parallel Large-Neighborhood Search Techniques for LNG Inventory ...  

E-print Network

For profitable operation of a capital intensive LNG project, it is necessary to optimally design ..... Parallel efficiency is a metric quantifying overall fraction ... Choice of static vs. dynamic resource allocation could have significant impact on the.

2014-04-17

45

A Parallel Grasp For The Steiner Tree Problem In Graphs Using Hybrid Local Search Strategy  

Microsoft Academic Search

In this paper, we present a parallel greedy randomized adaptive search procedure (GRASP) for the Steiner problem in graphs. GRASP is a two phase metaheuristic. In the first phase, solutions are constructed using a greedy randomized procedure. Local search is applied in the second phase, leading to a local minimum with respect to a specified neighborhood. In the Steiner problem

S. L. Martins; M. G. C. Resende; C. C. Ribeiro; P. M. Pardalos

2000-01-01

46

Parallel algorithms and architectures for very fast AI search  

SciTech Connect

A wide range of problems in natural and artificial intelligence, computer vision, computer graphics, database engineering, operations research, symbolic logic, robot manipulation and hardware design automation are special cases of Consistent Labeling Problems (CLP). CLP has long been viewed as an efficient computational model based on a unit constraint relation containing 2N-tuples of units and labels which specifies which N-tuples of labels are compatible with which N-tuples of units. Due to high computation cost and design complexity, most currently best-known algorithms and computer architectures have usually proven infeasible for solving the consistent labeling problems. Efficiency in CLP computation during the last decade has only been improved a few times. This research presents several parallel algorithms and computer architectures for solving CLP within a parallel processing framework. For problems of practical interest, 4 to 10 orders of magnitude of efficiency improvement can be easily reached. Several simple wafer scale computer architectures are given which implement these parallel algorithms at a surprisingly low cost.

Gu, J.

1989-01-01

47

Dynamic Parallelization of Modi cations to Directed Acyclic Graphs Lorenz Huelsbergen  

E-print Network

Dynamic Parallelization of Modi cations to Directed Acyclic Graphs Lorenz Huelsbergen Bell Laboratories lorenz@research.bell-labs.com Abstract We describe an interprocedural technique, called dynamic resolution, for the automatic parallelization of procedures that destructivelymanipulatedynamic DAGs. Dynamic

Huelsbergen, Lorenz

48

Architecture, implementation and parallelization of the software to search for periodic gravitational wave signals  

E-print Network

The parallelization, design and scalability of the \\sky code to search for periodic gravitational waves from rotating neutron stars is discussed. The code is based on an efficient implementation of the F-statistic using the Fast Fourier Transform algorithm. To perform an analysis of data from the advanced LIGO and Virgo gravitational wave detectors' network, which will start operating in 2015, hundreds of millions of CPU hours will be required - the code utilizing the potential of massively parallel supercomputers is therefore mandatory. We have parallelized the code using the Message Passing Interface standard, implemented a mechanism for combining the searches at different sky-positions and frequency bands into one extremely scalable program. The parallel I/O interface is used to escape bottlenecks, when writing the generated data into file system. This allowed to develop a highly scalable computation code, which would enable the data analysis at large scales on acceptable time scales. Benchmarking of the c...

Poghosyan, Gevorg; Streit, Achim; Bejger, Micha?; Krlak, Andrzej

2014-01-01

49

Feedback Directed Implicit Parallelism Microsoft Research, Cambridge, UK  

E-print Network

of all or part of this work for personal or classroom use is granted without fee provided that copies multiple parts of a program in parallel without needing to worry about data races. In practice we encounter five problems: · Programs vary in the amount of parallelism that is actually available. As we show

Harris, Timothy

50

When the Lowest Energy Does Not Induce Native Structures: Parallel Minimization of Multi-Energy Values by Hybridizing Searching Intelligences  

PubMed Central

Background Protein structure prediction (PSP), which is usually modeled as a computational optimization problem, remains one of the biggest challenges in computational biology. PSP encounters two difficult obstacles: the inaccurate energy function problem and the searching problem. Even if the lowest energy has been luckily found by the searching procedure, the correct protein structures are not guaranteed to obtain. Results A general parallel metaheuristic approach is presented to tackle the above two problems. Multi-energy functions are employed to simultaneously guide the parallel searching threads. Searching trajectories are in fact controlled by the parameters of heuristic algorithms. The parallel approach allows the parameters to be perturbed during the searching threads are running in parallel, while each thread is searching the lowest energy value determined by an individual energy function. By hybridizing the intelligences of parallel ant colonies and Monte Carlo Metropolis search, this paper demonstrates an implementation of our parallel approach for PSP. 16 classical instances were tested to show that the parallel approach is competitive for solving PSP problem. Conclusions This parallel approach combines various sources of both searching intelligences and energy functions, and thus predicts protein conformations with good quality jointly determined by all the parallel searching threads and energy functions. It provides a framework to combine different searching intelligence embedded in heuristic algorithms. It also constructs a container to hybridize different not-so-accurate objective functions which are usually derived from the domain expertise. PMID:23028708

Lu, Qiang; Xia, Xiao-Yan; Chen, Rong; Miao, Da-Jun; Chen, Sha-Sha; Quan, Li-Jun; Li, Hai-Ou

2012-01-01

51

APPSPACK 4.0 : asynchronous parallel pattern search for derivative-free optimization.  

SciTech Connect

APPSPACK is software for solving unconstrained and bound constrained optimization problems. It implements an asynchronous parallel pattern search method that has been specifically designed for problems characterized by expensive function evaluations. Using APPSPACK to solve optimization problems has several advantages: No derivative information is needed; the procedure for evaluating the objective function can be executed via a separate program or script; the code can be run in serial or parallel, regardless of whether or not the function evaluation itself is parallel; and the software is freely available. We describe the underlying algorithm, data structures, and features of APPSPACK version 4.0 as well as how to use and customize the software.

Gray, Genetha Anne; Kolda, Tamara Gibson

2004-12-01

52

From parallel to serial processing: a computational study of visual search.  

PubMed

A novel computational model of a preattentive system performing visual search is presented. The model processes displays of lines, reproduced from Wolfe, Friedman-Hill, Stewart, and O'Connell's (1992) and Treisman and Sato's (1990) visual-search experiments. The response times measured in these experiments suggest that some of the displays are searched serially, whereas others are scanned in parallel. Our neural network model operates in two phases. First, the visual displays are compressed via standard methods (principal component analysis), to overcome assumed biological capacity limitations. Second, the compressed representations are further processed to identify a target in the display. The model succeeds in fast detection of targets in experimentally labeled parallel displays, but fails with serial ones. Analysis of the compressed internal representations reveals that compressed parallel displays contain global information that enables instantaneous target detection. However, in representations of serial displays, this global information is obscure, and hence, a target detection system should resort to a serial, attentional scan of local features across the display. Our analysis provides a numerical criterion that is strongly correlated with the experimental response time slopes and enables us to reformulate Duncan and Humphreys's (1989) search surface, using precise quantitative measures. Our findings provide further insight into the important debate concerning the dichotomous versus continuous views of parallel/serial visual search. PMID:10572471

Cohen, E; Ruppin, E

1999-10-01

53

An efficient direct parallel spectral-element solver for separable ...  

E-print Network

Feb 24, 2007 ... and the localized nature of a spectral element discretization, this elliptic ..... If one of the dimensions is periodic, the Fourier transform can be performed in par- .... We observe from the table that the parallel efficiency is essen-.

2007-07-20

54

APPSPACK 4.0: Parallel Pattern Search for Derivative-Free ...  

E-print Network

mization problems has several advantages: No derivative information is ... Additional Key Words and Phrases: parallel derivative-free optimization, pattern search. 1. ...... APPSPACK 4.0 can be found in the README file included with the software. ..... U.S. Geological Survey Techniques of Water Resources Investigations.

2005-12-14

55

Architecture, implementation and parallelization of the software to search for periodic gravitational wave signals  

E-print Network

The parallelization, design and scalability of the \\sky code to search for periodic gravitational waves from rotating neutron stars is discussed. The code is based on an efficient implementation of the F-statistic using the Fast Fourier Transform algorithm. To perform an analysis of data from the advanced LIGO and Virgo gravitational wave detectors' network, which will start operating in 2015, hundreds of millions of CPU hours will be required - the code utilizing the potential of massively parallel supercomputers is therefore mandatory. We have parallelized the code using the Message Passing Interface standard, implemented a mechanism for combining the searches at different sky-positions and frequency bands into one extremely scalable program. The parallel I/O interface is used to escape bottlenecks, when writing the generated data into file system. This allowed to develop a highly scalable computation code, which would enable the data analysis at large scales on acceptable time scales. Benchmarking of the code on a Cray XE6 system was performed to show efficiency of our parallelization concept and to demonstrate scaling up to 50 thousand cores in parallel.

Gevorg Poghosyan; Sanchit Matta; Achim Streit; Micha? Bejger; Andrzej Krlak

2014-10-14

56

Attentional Control via Parallel Target-Templates in Dual-Target Search  

PubMed Central

Simultaneous search for two targets has been shown to be slower and less accurate than independent searches for the same two targets. Recent research suggests this dual-target cost may be attributable to a limit in the number of target-templates than can guide search at any one time. The current study investigated this possibility by comparing behavioural responses during single- and dual-target searches for targets defined by their orientation. The results revealed an increase in reaction times for dual- compared to single-target searches that was largely independent of the number of items in the display. Response accuracy also decreased on dual- compared to single-target searches: dual-target accuracy was higher than predicted by a model restricting search guidance to a single target-template and lower than predicted by a model simulating two independent single-target searches. These results are consistent with a parallel model of dual-target search in which attentional control is exerted by more than one target-template at a time. The requirement to maintain two target-templates simultaneously, however, appears to impose a reduction in the specificity of the memory representation that guides search for each target. PMID:24489793

Barrett, Doug J. K.; Zobay, Oliver

2014-01-01

57

A Parallel Framework for Multipoint Spiral Search in ab Initio Protein Structure Prediction.  

PubMed

Protein structure prediction is computationally a very challenging problem. A large number of existing search algorithms attempt to solve the problem by exploring possible structures and finding the one with the minimum free energy. However, these algorithms perform poorly on large sized proteins due to an astronomically wide search space. In this paper, we present a multipoint spiral search framework that uses parallel processing techniques to expedite exploration by starting from different points. In our approach, a set of random initial solutions are generated and distributed to different threads. We allow each thread to run for a predefined period of time. The improved solutions are stored threadwise. When the threads finish, the solutions are merged together and the duplicates are removed. A selected distinct set of solutions are then split to different threads again. In our ab initio protein structure prediction method, we use the three-dimensional face-centred-cubic lattice for structure-backbone mapping. We use both the low resolution hydrophobic-polar energy model and the high-resolution 20 20 energy model for search guiding. The experimental results show that our new parallel framework significantly improves the results obtained by the state-of-the-art single-point search approaches for both energy models on three-dimensional face-centred-cubic lattice. We also experimentally show the effectiveness of mixing energy models within parallel threads. PMID:24744779

Rashid, Mahmood A; Shatabda, Swakkhar; Newton, M A Hakim; Hoque, Md Tamjidul; Sattar, Abdul

2014-01-01

58

A Parallel Framework for Multipoint Spiral Search in ab Initio Protein Structure Prediction  

PubMed Central

Protein structure prediction is computationally a very challenging problem. A large number of existing search algorithms attempt to solve the problem by exploring possible structures and finding the one with the minimum free energy. However, these algorithms perform poorly on large sized proteins due to an astronomically wide search space. In this paper, we present a multipoint spiral search framework that uses parallel processing techniques to expedite exploration by starting from different points. In our approach, a set of random initial solutions are generated and distributed to different threads. We allow each thread to run for a predefined period of time. The improved solutions are stored threadwise. When the threads finish, the solutions are merged together and the duplicates are removed. A selected distinct set of solutions are then split to different threads again. In our ab initio protein structure prediction method, we use the three-dimensional face-centred-cubic lattice for structure-backbone mapping. We use both the low resolution hydrophobic-polar energy model and the high-resolution 20 20 energy model for search guiding. The experimental results show that our new parallel framework significantly improves the results obtained by the state-of-the-art single-point search approaches for both energy models on three-dimensional face-centred-cubic lattice. We also experimentally show the effectiveness of mixing energy models within parallel threads. PMID:24744779

Rashid, Mahmood A.; Newton, M. A. Hakim; Hoque, Md Tamjidul; Sattar, Abdul

2014-01-01

59

Direct detection searches for axion dark matter  

NASA Astrophysics Data System (ADS)

The axion is both a compelling dark matter candidate and provides an elegant solution to the strong CP problem. The axion haloscope technique has the potential to detect dark matter axions. ADMX (the Axion Dark Matter eXperiment) is an implementation of the axion haloscope technique, and has undergone a series of sensitivity-improving upgrades. With the impending addition of a dilution refrigerator, ADMX is poised to search a large region of plausible dark matter axion masses. Meanwhile, a number of other axion experimental techniques are being considered to explore other axion masses relevant to dark matter.

Rybka, Gray

2014-09-01

60

A direct search for Dirac magnetic monopoles  

E-print Network

Magnetic monopoles are highly ionizing and curve in the direction of the magnetic field. A new dedicated magnetic monopole trigger at CDF, which requires large light pulses in the scintillators of the time-of-flight system, ...

Mulhearn, Michael James

2005-01-01

61

Target intersection probabilities for parallel-line and continuous-grid types of search  

USGS Publications Warehouse

The expressions for calculating the probability of intersection of hidden targets of different sizes and shapes for parallel-line and continuous-grid types of search can be formulated by vsing the concept of conditional probability. When the prior probability of the orientation of a widden target is represented by a uniform distribution, the calculated posterior probabilities are identical with the results obtained by the classic methods of probability. For hidden targets of different sizes and shapes, the following generalizations about the probability of intersection can be made: (1) to a first approximation, the probability of intersection of a hidden target is proportional to the ratio of the greatest dimension of the target (viewed in plane projection) to the minimum line spacing of the search pattern; (2) the shape of the hidden target does not greatly affect the probability of the intersection when the largest dimension of the target is small relative to the minimum spacing of the search pattern, (3) the probability of intersecting a target twice for a particular type of search can be used as a lower bound if there is an element of uncertainty of detection for a particular type of tool; (4) the geometry of the search pattern becomes more critical when the largest dimension of the target equals or exceeds the minimum spacing of the search pattern; (5) for elongate targets, the probability of intersection is greater for parallel-line search than for an equivalent continuous square-grid search when the largest dimension of the target is less than the minimum spacing of the search pattern, whereas the opposite is true when the largest dimension exceeds the minimum spacing; (6) the probability of intersection for nonorthogonal continuous-grid search patterns is not greatly different from the probability of intersection for the equivalent orthogonal continuous-grid pattern when the orientation of the target is unknown. The probability of intersection for an elliptically shaped target can be approximated by treating the ellipse as intermediate between a circle and a line. A search conducted along a continuous rectangular grid can be represented as intermediate between a search along parallel lines and along a continuous square grid. On this basis, an upper and lower bound for the probability of intersection of an elliptically shaped target for a continuous rectangular grid can be calculated. Charts have been constructed that permit the values for these probabilities to be obtained graphically. The use of conditional probability allows the explorationist greater flexibility in considering alternate search strategies for locating hidden targets. ?? 1977 Plenum Publishing Corp.

McCammon, R. B.

1977-01-01

62

Directed search for continuous gravitational waves from the Galactic center  

E-print Network

We present the results of a directed search for continuous gravitational waves from unknown, isolated neutron stars in the Galactic center region, performed on two years of data from LIGOs fifth science run from two LIGO ...

Aggarwal, Nancy

63

Review on Non-directional Direct Dark Matter Searches  

NASA Astrophysics Data System (ADS)

An overview of non-directional direct detection methods is given. The currently leading experiments for spin independent WIMPs interactions are using simultaneous measurement of two quantities for event-by-event background discrimination in cryogenic bolometers and noble gas like xenon. Besides these, several interesting techniques have been developped, each having a specific advantage concerning e.g. energy threshold lowering or strong immunity to ionizing radiations background. Technologies used and most recent results about spin-dependent and spin-independent cases are presented.

Censier, B.

2012-02-01

64

A Direct Search for Dirac Magnetic Monopoles  

SciTech Connect

Magnetic monopoles are highly ionizing and curve in the direction of the magnetic field. A new dedicated magnetic monopole trigger at CDF, which requires large light pulses in the scintillators of the time-of-flight system, remains highly efficient to monopoles while consuming a tiny fraction of the available trigger bandwidth. A specialized offline reconstruction checks the central drift chamber for large dE/dx tracks which do not curve in the plane perpendicular to the magnetic field. We observed zero monopole candidate events in 35.7 pb{sup -1} of proton-antiproton collisions at {radical}s = 1.96 TeV. This implies a monopole production cross section limit {sigma} < 0.2 pb for monopoles with mass between 100 and 700 GeV, and, for a Drell-Yan like pair production mechanism, a mass limit m > 360 GeV.

Mulhearn, Michael James; /MIT

2004-10-01

65

Improving the efficiency of parallel alternating directions algorithm for time dependent problems  

NASA Astrophysics Data System (ADS)

We consider the time dependent Stokes equation on a finite time interval and on a uniform rectangular mesh, written in terms of velocity and pressure. A parallel algorithm based on a direction splitting approach is implemented. Our work is motivated by the need to improve the parallel efficiency of our supercomputer implementation of the parallel algorithm. We are targeting the IBM Blue Gene/P massively parallel computer, which features a 3D torus interconnect. We study the impact of the domain partitioning on the performance of the considered parallel algorithm for solving the time dependent Stokes equation. Here, different parallel partitioning strategies are given special attention. The implementation is tested on the IBM Blue Gene/P and the presented results from numerical tests confirm that decreasing the communication time better parallel properties of the algorithm are obtained.

Ganzha, Maria; Kosturski, Nikola; Lirkov, Ivan

2012-10-01

66

Low-power word-parallel nearest-Hamming-distance search circuit based on frequency mapping  

Microsoft Academic Search

Distance-frequency mapping with ring oscillators, adjustable in discrete steps, enables fast word-parallel nearest-Hamming-distance search with low power consumption. High robustness against fabrication-related variations of the MOSFET characteristics is achieved in addition. A test chip in 180 nm CMOS technology with 64 words, each consisting of 256 bits, consumes less than 36.5 mW and 307 ?W at supply voltages of 1.8

H. J. Mattausch; Wataru Imafuku; Tania Ansari; Akio Kawabata; Tetsushi Koide

2010-01-01

67

Virtual Parallel Computing and a Search Algorithm Using Matrix Product States  

NASA Astrophysics Data System (ADS)

We propose a form of parallel computing on classical computers that is based on matrix product states. The virtual parallelization is accomplished by representing bits with matrices and by evolving these matrices from an initial product state that encodes multiple inputs. Matrix evolution follows from the sequential application of gates, as in a logical circuit. The action by classical probabilistic one-bit and deterministic two-bit gates such as NAND are implemented in terms of matrix operations and, as opposed to quantum computing, it is possible to copy bits. We present a way to explore this method of computation to solve search problems and count the number of solutions. We argue that if the classical computational cost of testing solutions (witnesses) requires less than O(n^2) local two-bit gates acting on n bits, the search problem can be fully solved in subexponential time. Therefore, for this restricted type of search problem, the virtual parallelization scheme is faster than Grover's quantum algorithm.

Mucciolo, Eduardo; Chamon, Claudio

2013-03-01

68

Virtual parallel computing and a search algorithm using matrix product states.  

PubMed

We propose a form of parallel computing on classical computers that is based on matrix product states. The virtual parallelization is accomplished by representing bits with matrices and by evolving these matrices from an initial product state that encodes multiple inputs. Matrix evolution follows from the sequential application of gates, as in a logical circuit. The action by classical probabilistic one-bit and deterministic two-bit gates such as NAND are implemented in terms of matrix operations and, as opposed to quantum computing, it is possible to copy bits. We present a way to explore this method of computation to solve search problems and count the number of solutions. We argue that if the classical computational cost of testing solutions (witnesses) requires less than O(n2) local two-bit gates acting on n bits, the search problem can be fully solved in subexponential time. Therefore, for this restricted type of search problem, the virtual parallelization scheme is faster than Grover's quantum algorithm. PMID:22861832

Chamon, Claudio; Mucciolo, Eduardo R

2012-07-20

69

J. Parallel Distrib. Comput. 70 (2010) 183188 Contents lists available at ScienceDirect  

E-print Network

J. Parallel Distrib. Comput. 70 (2010) 183­188 Contents lists available at ScienceDirect J. Parallel Distrib. Comput. journal homepage: www.elsevier.com/locate/jpdc Reevaluating Amdahl's law in the multicore era Xian-He Sun , Yong Chen Computer Science Department, Illinois Institute of Technology, United

Sun, Xian-He

70

Simulating a Direction-Finder Search for an ELT  

NASA Technical Reports Server (NTRS)

A computer program simulates the operation of direction-finding equipment engaged in a search for an emergency locator transmitter (ELT) aboard an aircraft that has crashed. The simulated equipment is patterned after the equipment used by the Civil Air Patrol to search for missing aircraft. The program is designed to be used for training in radio direction-finding and/or searching for missing aircraft without incurring the expense and risk of using real aircraft and ground search resources. The program places a hidden ELT on a map and enables the user to search for the location of the ELT by moving a 14 NASA Tech Briefs, March 2005 small aircraft image around the map while observing signal-strength and direction readings on a simulated direction- finding locator instrument. As the simulated aircraft is turned and moved on the map, the program updates the readings on the direction-finding instrument to reflect the current position and heading of the aircraft relative to the location of the ELT. The software is distributed in a zip file that contains an installation program. The software runs on the Microsoft Windows 9x, NT, and XP operating systems.

Bream, Bruce

2005-01-01

71

An intelligent maritime search and rescue directing system  

NASA Astrophysics Data System (ADS)

Maritime Search and Rescue (SAR) is the fast, systematical and efficient operations to rescue persons in maritime distress at sea and control the spread of distress incident. This paper introduces an intelligent maritime search and rescue directing system built by Tianjin Maritime Safety Administration. It is an intelligent assistant tool used in the operation of maritime search and rescue. It integrates five subsystems - marine communication system, vessel monitoring system, intelligent decision assistant system, on-scene information collecting system, and remote directing system. It is a representative application system of Locate Based Service. This system is successfully applied in Tianjin Maritime Safety Administration and China 2006's BoHai Sea Search and Rescue.

Zhang, Anmin; Sui, Haigang

2006-10-01

72

Direct Search for Low Mass Dark Matter Particles with CCDs  

A direct dark matter search is performed using fully-depleted high-resistivity CCD detectors. Due to their low electronic readout noise (RMS ~7 eV) these devices operate with a very low detection threshold of 40 eV, making the search for dark matter particles with low masses (~5 GeV) possible. The results of an engineering run performed in a shallow underground site are presented, demonstrating the potential of this technology in the low mass region.

Barreto, J [Rio de Janeiro Federal U.; Cease, H.; Diehl, H.T.; Estrada, J.; Flaugher, B.; Harrison, N.; Jones, J.; Kilminster, B [Fermilab; Molina, J [Asuncion Natl. U.; Smith, J.; Sonnenschein, A [Fermilab

2012-05-15

73

A GPU based implementation of direct multi-bit search (DMS) screen algorithm  

NASA Astrophysics Data System (ADS)

In this paper, we study the feasibility for using programmable Graphics Processing Unit (GPU) technology for image halftoning, in particular implementing the computationally intense Direct Multi-bit Search (DMS) Screen algorithm. Multi-bit screening is an extension of binary screening, in which every pixel in continuoustone image can be rendered to one among multiple output states. For example, a 2 bit printer is capable of printing with four different drop sizes. In our previous work, we have extended the Direct Binary Search (DBS) to the multi-bit case using Direct Multi-bit Search (DMS) where at every pixel the algorithm chooses the best drop output state to create a visually pleasing halftone pattern without any user defined guidance. This process is repeated throughout the entire range of gray levels while satisfying the stacking constraint to create a high quality multi-bit screen (dither mask). In this paper, we illustrate how employing Graphics Processing Units (GPU) can speed-up intensive DMS image processing operations. Particularly, we illustrate how different modules can be been parallelized. The main goal of many of the previous articles regarding DBS is to decrease the execution time of the algorithm. One of the most common approaches is to decrease the neighborhood size or filter size. The proposed parallel approach allows us to use a large neighborhood and filter size, to achieve the highest halftone quality, while having minimal impact on performance. In addition, we also demonstrate processing several non-overlapping neighborhoods in parallel, by utilizing the GPU's parallel architecture, to further improve the computational efficiency.

Trager, Barry; Chandu, Kartheek; Wu, Chai Wah; Stanich, Mikel

2013-02-01

74

Direct Non-baryonic Dark Matter Search - An experimental Review  

E-print Network

This review will present the latest advances in the search for non-baryonic dark matter from an experimental point of view, focusing more particularly on the direct detection approach. After a brief reminder of the main motivations for this search, we will expose the physical basis of WIMP detection, its advantages and limitations. The current techniques having achieved the most competitive results in terms of sensitivity will then be discussed. We will conclude with a rapid overview of the future of direct detection experiments, the techniques considered and their sensitivity goals.

S. Fiorucci

2004-06-11

75

The Self-Directed Search and Career Self-Efficacy.  

ERIC Educational Resources Information Center

High school students (n=237) completed the Self-Directed Search (SDS) and Task Specific Occupational Self-Efficacy Scale. A significant relationship between responses to the two instruments supports the validity of the SDS in predicting career self-efficacy. (SK)

Feehan, Patrick F.; Johnston, Joseph A.

1999-01-01

76

The Self-Directed Search and Career Self-Efficacy  

Microsoft Academic Search

This paper presents the results of a study aimed at furthering understanding of the meaning of responses to Holland's Self-Directed Search (SDS). Drawing on current social cognitive theory, this study provides some evidence that SDS Summary scores might be predictive of respondents' future self-efficacy expectations. A significant relationship was found between responses to the SDS and an instrument specifically designed

Patrack F. Feehan; Joseph A. Johnston

1999-01-01

77

Nonlinear programming by mesh adaptive direct searches 1  

Microsoft Academic Search

This paper is intended not as a survey, but as an introduction to some ideas behind the class of mesh adaptive direct search (MADS) methods. Space limitations dictate a brief description of various key topics to be provided along with several references, which themselves provide further references. The convergence theory for the methods presented here make a case for clos-

Mark A. Abramson; J. E. Dennis Jr

78

Physician Assistant Self-Directed Search Holland Codes  

ERIC Educational Resources Information Center

A mailed survey was used to identify the vocational interests of physician assistants (PAs) as measured by Holland's Self-Directed Search (SDS) Form R. A random sample of 2,323 PAs from the American Academy of Physician Assistants' mailing list was sent a survey to identify a pool of practicing PAs satisfied with their career choices for further

LaBarbera, Dawn M.

2005-01-01

79

A NUMA Aware Scheduler for a Parallel Sparse Direct Solver6 Mathieu Favergea  

E-print Network

A NUMA Aware Scheduler for a Parallel Sparse Direct Solver6 Mathieu Favergea , Pierre Rameta a was a bottleneck to the use of direct solvers. New NUMA (Non Uniform Memory Access) architectures have now for NUMA architectures. We also introduce a simple way to schedule dynamically an application based

Paris-Sud XI, Université de

80

A parallel implicit method for the direct numerical simulation of wall-bounded compressible turbulence  

E-print Network

A parallel implicit method for the direct numerical simulation of wall-bounded compressible-order accurate implicit temporal numerical scheme for the direct numerical simulation of turbulent flows. The numerical simulation results are compared with the results given by explicit Runge­Kutta schemes

Martín, Pino

81

Semi-automatic parallelization of direct and inverse problems for geothermal simulation  

Microsoft Academic Search

We describe a strategy for parallelizing a geothermal simula- tion package using the shared-memory programming model OpenMP. During the code development OpenMP is em- ployed for the direct problem in such a way that, in a sub- sequent step, the OpenMP-parallelized code can be trans- formed via automatic differentiation into an OpenMP-paral- lelized code capable of computing derivatives for the

H. Martin Bcker; Arno Rasch; Volker Rath; Andreas Wolf

2009-01-01

82

Directed search for continuous gravitational waves from the Galactic center  

NASA Astrophysics Data System (ADS)

We present the results of a directed search for continuous gravitational waves from unknown, isolated neutron stars in the Galactic center region, performed on two years of data from LIGOs fifth science run from two LIGO detectors. The search uses a semicoherent approach, analyzing coherently 630 segments, each spanning 11.5 hours, and then incoherently combining the results of the single segments. It covers gravitational wave frequencies in a range from 78 to 496 Hz and a frequency-dependent range of first-order spindown values down to -7.8610-8Hz/s at the highest frequency. No gravitational waves were detected. The 90% confidence upper limits on the gravitational wave amplitude of sources at the Galactic center are 3.3510-25 for frequencies near 150 Hz. These upper limits are the most constraining to date for a large-parameter-space search for continuous gravitational wave signals.

Aasi, J.; Abadie, J.; Abbott, B. P.; Abbott, R.; Abbott, T.; Abernathy, M. R.; Accadia, T.; Acernese, F.; Adams, C.; Adams, T.; Adhikari, R. X.; Affeldt, C.; Agathos, M.; Aggarwal, N.; Aguiar, O. D.; Ajith, P.; Allen, B.; Allocca, A.; Amador Ceron, E.; Amariutei, D.; Anderson, R. A.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C.; Areeda, J.; Ast, S.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; Austin, L.; Aylott, B. E.; Babak, S.; Baker, P. T.; Ballardin, G.; Ballmer, S. W.; Barayoga, J. C.; Barker, D.; Barnum, S. H.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barton, M. A.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J.; Bauchrowitz, J.; Bauer, Th. S.; Bebronne, M.; Behnke, B.; Bejger, M.; Beker, M. G.; Bell, A. S.; Bell, C.; Belopolski, I.; Bergmann, G.; Berliner, J. M.; Bertolini, A.; Bessis, D.; Betzwieser, J.; Beyersdorf, P. T.; Bhadbhade, T.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Bitossi, M.; Bizouard, M. A.; Black, E.; Blackburn, J. K.; Blackburn, L.; Blair, D.; Blom, M.; Bock, O.; Bodiya, T. P.; Boer, M.; Bogan, C.; Bond, C.; Bondu, F.; Bonelli, L.; Bonnand, R.; Bork, R.; Born, M.; Bose, S.; Bosi, L.; Bowers, J.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brannen, C. A.; Brau, J. E.; Breyer, J.; Briant, T.; Bridges, D. O.; Brillet, A.; Brinkmann, M.; Brisson, V.; Britzger, M.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brckner, F.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Caldern Bustillo, J.; Calloni, E.; Camp, J. B.; Campsie, P.; Cannon, K. C.; Canuel, B.; Cao, J.; Capano, C. D.; Carbognani, F.; Carbone, L.; Caride, S.; Castiglia, A.; Caudill, S.; Cavagli, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C.; Cesarini, E.; Chakraborty, R.; Chalermsongsak, T.; Chao, S.; Charlton, P.; Chassande-Mottin, E.; Chen, X.; Chen, Y.; Chincarini, A.; Chiummo, A.; Cho, H. S.; Chow, J.; Christensen, N.; Chu, Q.; Chua, S. S. Y.; Chung, S.; Ciani, G.; Clara, F.; Clark, D. E.; Clark, J. A.; Cleva, F.; Coccia, E.; Cohadon, P.-F.; Colla, A.; Colombini, M.; Constancio, M., Jr.; Conte, A.; Conte, R.; Cook, D.; Corbitt, T. R.; Cordier, M.; Cornish, N.; Corsi, A.; Costa, C. A.; Coughlin, M. W.; Coulon, J.-P.; Countryman, S.; Couvares, P.; Coward, D. M.; Cowart, M.; Coyne, D. C.; Craig, K.; Creighton, J. D. E.; Creighton, T. D.; Crowder, S. G.; Cumming, A.; Cunningham, L.; Cuoco, E.; Dahl, K.; Dal Canton, T.; Damjanic, M.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Dattilo, V.; Daudert, B.; Daveloza, H.; Davier, M.; Davies, G. S.; Daw, E. J.; Day, R.; Dayanga, T.; De Rosa, R.; Debreczeni, G.; Degallaix, J.; Del Pozzo, W.; Deleeuw, E.; Delglise, S.; Denker, T.; Dent, T.; Dereli, H.; Dergachev, V.; DeRosa, R.; DeSalvo, R.; Dhurandhar, S.; Di Fiore, L.; Di Lieto, A.; Di Palma, I.; Di Virgilio, A.; Daz, M.; Dietz, A.; Dmitry, K.; Donovan, F.; Dooley, K. L.; Doravari, S.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Dumas, J.-C.; Dwyer, S.; Eberle, T.; Edwards, M.; Effler, A.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Endr?czi, G.; Essick, R.; Etzel, T.; Evans, K.; Evans, M.; Evans, T.; Factourovich, M.; Fafone, V.; Fairhurst, S.; Fang, Q.; Farr, B.; Farr, W.; Favata, M.; Fazi, D.; Fehrmann, H.; Feldbaum, D.; Ferrante, I.; Ferrini, F.; Fidecaro, F.; Finn, L. S.; Fiori, I.; Fisher, R.; Flaminio, R.; Foley, E.; Foley, S.; Forsi, E.; Forte, L. A.; Fotopoulos, N.; Fournier, J.-D.; Franco, S.; Frasca, S.; Frasconi, F.; Frede, M.; Frei, M.; Frei, Z.; Freise, A.; Frey, R.; Fricke, T. T.; Fritschel, P.; Frolov, V. V.; Fujimoto, M.-K.; Fulda, P.; Fyffe, M.; Gair, J.; Gammaitoni, L.; Garcia, J.; Garufi, F.; Gehrels, N.; Gemme, G.; Genin, E.; Gennai, A.; Gergely, L.; Ghosh, S.; Giaime, J. A.; Giampanis, S.; Giardina, K. D.; Giazotto, A.; Gil-Casanova, S.; Gill, C.; Gleason, J.; Goetz, E.; Goetz, R.; Gondan, L.; Gonzlez, G.; Gordon, N.; Gorodetsky, M. L.; Gossan, S.; Goler, S.; Gouaty, R.; Graef, C.; Graff, P. B.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greenhalgh, R. J. S.; Gretarsson, A. M.; Griffo, C.; Grote, H.; Grover, K.; Grunewald, S.; Guidi, G. M.; Guido, C.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hall, B.; Hall, E.; Hammer, D.; Hammond, G.; Hanke, M.; Hanks, J.; Hanna, C.; Hanson, J.; Harms, J.; Harry, G. M.; Harry, I. W.; Harstad, E. D.; Hartman, M. T.; Haughian, K.; Hayama, K.; Heefner, J.; Heidmann, A.; Heintze, M.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, I. S.; Heptonstall, A. W.; Heurs, M.; Hild, S.; Hoak, D.; Hodge, K. A.; Holt, K.; Holtrop, M.; Hong, T.; Hooper, S.; Horrom, T.; Hosken, D. J.; Hough, J.; Howell, E. J.; Hu, Y.; Hua, Z.; Huang, V.; Huerta, E. A.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh, M.; Huynh-Dinh, T.; Iafrate, J.; Ingram, D. R.

2013-11-01

83

A mesh adaptive direct search algorithm for multiobjective optimization  

Microsoft Academic Search

This work studies multiobjective optimization (MOP) of nonsmooth functions subject to general constraints. We first present definitions and optimality conditions as well as some single-objective formulations of MOP, parameterized with respect to some reference point in the space of objective functions. Next, we propose a new algorithm called MultiMads (multiobjective mesh adaptive direct search) for MOP. MultiMads generates an approximation

Charles Audet; Gilles Savard; Walid Zghal

2010-01-01

84

Mixed Digital-Analog Associative Memory Enabling Fully-Parallel Nearest Euclidean Distance Search  

NASA Astrophysics Data System (ADS)

In this paper, an associative memory architecture with mixed digital-analog search circuitry is proposed, which enables a fully-parallel nearest match-data search based on the Euclidean distance between input pattern and stored reference patterns. A test chip, implementing the proposed architecture, was designed in 0.35 ?m complementary metal-oxide-semiconductor (CMOS) technology with two-poly and three-metal layers. The nearest-match unit consumes only 0.64 mm2 (12.5% of the total design area), while the whole chip area is 5.12 mm2. The layout-based simulated winner-search time, the time to determine the best-matching reference-data word for an input-data word among a database of 64 reference patterns (5-bit, 16 units), is lower than 160 ns. This corresponds to a performance requirement of 27 giga operations per second (GOPS)/mm2, if a general purpose computer with the same chip area would have to run the same workload. Furthermore, the power dissipation of the designed test chip is only about 38 mW/mm2 at this high processing performance.

Abedin, Md. Anwarul; Tanaka, Yuki; Ahmadi, Ali; Koide, Tetsushi; Mattausch, Hans Juergen

2007-04-01

85

Retrieval comparison of EndNote to search MEDLINE (Ovid and PubMed) versus searching them directly.  

PubMed

Using EndNote version 7.0, the authors tested the search capabilities of the EndNote search engine for retrieving citations from MEDLINE for importation into EndNote, a citation management software package. Ovid MEDLINE and PubMed were selected for the comparison. Several searches were performed on Ovid MEDLINE and PubMed using EndNote as the search engine, and the same searches were run on both Ovid and PubMed directly. Findings indicate that it is preferable to search MEDLINE directly rather than using EndNote. The publishers of EndNote do warn its users about the limitations of their product as a search engine when searching external databases. In this article, the limitations of EndNote as a search engine for searching MEDLINE were explored as related to MeSH, non-MeSH, citation verification, and author searching. PMID:15364649

Gall, Carole; Brahmi, Frances A

2004-01-01

86

PoS(ICHEP2010)539 Dark Matter direct detection searches  

E-print Network

PoS(ICHEP2010)539 Dark Matter direct detection searches Jules Gascon IPNL, Université de Lyon searches for Dark Matter is presented. These experi- ments look for energetic recoiling ions produced)539 Direct Searches for Dark Matter Jules Gascon Direct searches for Dark Matter in the form of Weakly

Boyer, Edmond

87

Privacy-Preserving Location-Based Query Using Location Indexes and Parallel Searching in Distributed Networks  

PubMed Central

An efficient location-based query algorithm of protecting the privacy of the user in the distributed networks is given. This algorithm utilizes the location indexes of the users and multiple parallel threads to search and select quickly all the candidate anonymous sets with more users and their location information with more uniform distribution to accelerate the execution of the temporal-spatial anonymous operations, and it allows the users to configure their custom-made privacy-preserving location query requests. The simulated experiment results show that the proposed algorithm can offer simultaneously the location query services for more users and improve the performance of the anonymous server and satisfy the anonymous location requests of the users. PMID:24790579

Liu, Lei; Zhao, Jing

2014-01-01

88

Direct observation of parallel folding pathways revealed using a symmetric repeat protein system.  

PubMed

Although progress has been made to determine the native fold of a polypeptide from its primary structure, the diversity of pathways that connect the unfolded and folded states has not been adequately explored. Theoretical and computational studies predict that proteins fold through parallel pathways on funneled energy landscapes, although experimental detection of pathway diversity has been challenging. Here, we exploit the high translational symmetry and the direct length variation afforded by linear repeat proteins to directly detect folding through parallel pathways. By comparing folding rates of consensus ankyrin repeat proteins (CARPs), we find a clear increase in folding rates with increasing size and repeat number, although the size of the transition states (estimated from denaturant sensitivity) remains unchanged. The increase in folding rate with chain length, as opposed to a decrease expected from typical models for globular proteins, is a clear demonstration of parallel pathways. This conclusion is not dependent on extensive curve-fitting or structural perturbation of protein structure. By globally fitting a simple parallel-Ising pathway model, we have directly measured nucleation and propagation rates in protein folding, and have quantified the fluxes along each path, providing a detailed energy landscape for folding. This finding of parallel pathways differs from results from kinetic studies of repeat-proteins composed of sequence-variable repeats, where modest repeat-to-repeat energy variation coalesces folding into a single, dominant channel. Thus, for globular proteins, which have much higher variation in local structure and topology, parallel pathways are expected to be the exception rather than the rule. PMID:24988356

Aksel, Tural; Barrick, Doug

2014-07-01

89

Globalization strategies forMesh Adaptive Direct Search  

Microsoft Academic Search

The class of Mesh Adaptive Direct Search (Mads) algorithms is designed for the optimization of constrained black-box problems. The purpose of this paper is to compare instantiations\\u000a of Mads under different strategies to handle constraints. Intensive numerical tests are conducted from feasible and\\/or infeasible\\u000a starting points on three real engineering applications.\\u000a \\u000a \\u000a The three instantiations are Gps, LTMads and OrthoMads. Constraints

Charles Audet; J. E. Dennis Jr; Sbastien Le Digabel

2010-01-01

90

Interchromosomal Homology Searches Drive Directional ALT Telomere Movement and Synapsis.  

PubMed

Telomere length maintenance is a requisite feature of cellular immortalization and a hallmark of human cancer. While most human cancers express telomerase activity, ?10%-15% employ a recombination-dependent telomere maintenance pathway known as alternative lengthening of telomeres (ALT) that is characterized by multitelomere clusters and associated promyelocytic leukemia protein bodies. Here, we show that a DNA double-strand break (DSB) response at ALT telomeres triggers long-range movement and clustering between chromosome termini, resulting in homology-directed telomere synthesis. Damaged telomeres initiate increased random surveillance of nuclear space before displaying rapid directional movement and association with recipient telomeres over micron-range distances. This phenomenon required Rad51 and the Hop2-Mnd1 heterodimer, which are essential for homologous chromosome synapsis during meiosis. These findings implicate a specialized homology searching mechanism in ALT-dependent telomere maintenance and provide a molecular basis underlying the preference for recombination between nonsister telomeres during ALT. PMID:25259924

Cho, Nam Woo; Dilley, Robert L; Lampson, Michael A; Greenberg, Roger A

2014-09-25

91

Bolometric direct dark matter search at the University of Tokyo  

NASA Astrophysics Data System (ADS)

A direct dark matter search experiment is now under preparation at the University of Tokyo. An array of LiF bolometers with a total mass of roughly one kilogram is to be used aiming at a direct detection of spin-dependently interacting supersymmetric neutralinos. A dedicated low-radioactivity dilution refrigerator for the bolometer has been constructed along with a small on-line helium requefier to help the detector operation in the underground laboratory where liquid helium supply is not always available. A long term test operation of a bolometer at the University of Tokyo proved the stability of the detector for more than 45 days. The detector will be installed in the Nokogiri-yama underground laboratory of the Institute for Cosmic Ray Research of the University of Tokyo. The laboratory is 200 m w.e. deep and located about 60 km to the south of Tokyo.

Minowa, Makoto; Ito, Yutaka; Ootani, Wataru; Nishigaki, Keiji; Kishimoto, Yasuhiro; Watanabe, Takayuki; Inoue, Yoshizumi; Ootuka, Youiti

1996-11-01

92

An Automated Directed Spectral Search Methodology for Small Target Detection  

NASA Astrophysics Data System (ADS)

Much of the current efforts in remote sensing tackle macro-level problems such as determining the extent of wheat in a field, the general health of vegetation or the extent of mineral deposits in an area. However, for many of the remaining remote sensing challenges being studied currently, such as border protection, drug smuggling, treaty verification, and the war on terror, most targets are very small in nature - a vehicle or even a person. While in typical macro-level problems the objective vegetation is in the scene, for small target detection problems it is not usually known if the desired small target even exists in the scene, never mind finding it in abundance. The ability to find specific small targets, such as vehicles, typifies this problem. Complicating the analyst's life, the growing number of available sensors is generating mountains of imagery outstripping the analysts' ability to visually peruse them. This work presents the important factors influencing spectral exploitation using multispectral data and suggests a different approach to small target detection. The methodology of directed search is presented, including the use of scene-modeled spectral libraries, various search algorithms, and traditional statistical and ROC curve analysis. The work suggests a new metric to calibrate analysis labeled the analytic sweet spot as well as an estimation method for identifying the sweet spot threshold for an image. It also suggests a new visualization aid for highlighting the target in its entirety called nearest neighbor inflation (NNI). It brings these all together to propose that these additions to the target detection arena allow for the construction of a fully automated target detection scheme. This dissertation next details experiments to support the hypothesis that the optimum detection threshold is the analytic sweet spot and that the estimation method adequately predicts it. Experimental results and analysis are presented for the proposed directed search techniques of spectral image based small target detection. It offers evidence of the functionality of the NNI visualization and also provides evidence that the increased spectral dimensionality of the 8-band Worldview-2 datasets provides noteworthy improvement in results over traditional 4-band multispectral datasets. The final experiment presents the results from a prototype fully automated target detection scheme in support of the overarching premise. This work establishes the analytic sweet spot as the optimum threshold defined as the point where error detection rate curves -- false detections vs. missing detections -- cross. At this point the errors are minimized while the detection rate is maximized. It then demonstrates that taking the first moment statistic of the histogram of calculated target detection values from a detection search with test threshold set arbitrarily high will estimate the analytic sweet spot for that image. It also demonstrates that directed search techniques -- when utilized with appropriate scene-specific modeled signatures and atmospheric compensations -- perform at least as well as in-scene search techniques 88% of the time and grossly under-performing only 11% of the time; the in-scene only performs as well or better 50% of the time. It further demonstrates the clear advantage increased multispectral dimensionality brings to detection searches improving performance in 50% of the cases while performing at least as well 72% of the time. Lastly, it presents evidence that a fully automated prototype performs as anticipated laying the groundwork for further research into fully automated processes for small target detection.

Grossman, Stanley I.

93

A direct-execution parallel architecture for the Advanced Continuous Simulation Language (ACSL)  

NASA Technical Reports Server (NTRS)

A direct-execution parallel architecture for the Advanced Continuous Simulation Language (ACSL) is presented which overcomes the traditional disadvantages of simulations executed on a digital computer. The incorporation of parallel processing allows the mapping of simulations into a digital computer to be done in the same inherently parallel manner as they are currently mapped onto an analog computer. The direct-execution format maximizes the efficiency of the executed code since the need for a high level language compiler is eliminated. Resolution is greatly increased over that which is available with an analog computer without the sacrifice in execution speed normally expected with digitial computer simulations. Although this report covers all aspects of the new architecture, key emphasis is placed on the processing element configuration and the microprogramming of the ACLS constructs. The execution times for all ACLS constructs are computed using a model of a processing element based on the AMD 29000 CPU and the AMD 29027 FPU. The increase in execution speed provided by parallel processing is exemplified by comparing the derived execution times of two ACSL programs with the execution times for the same programs executed on a similar sequential architecture.

Carroll, Chester C.; Owen, Jeffrey E.

1988-01-01

94

Parallel Directionally Split Solver Based on Reformulation of Pipelined Thomas Algorithm  

NASA Technical Reports Server (NTRS)

In this research an efficient parallel algorithm for 3-D directionally split problems is developed. The proposed algorithm is based on a reformulated version of the pipelined Thomas algorithm that starts the backward step computations immediately after the completion of the forward step computations for the first portion of lines This algorithm has data available for other computational tasks while processors are idle from the Thomas algorithm. The proposed 3-D directionally split solver is based on the static scheduling of processors where local and non-local, data-dependent and data-independent computations are scheduled while processors are idle. A theoretical model of parallelization efficiency is used to define optimal parameters of the algorithm, to show an asymptotic parallelization penalty and to obtain an optimal cover of a global domain with subdomains. It is shown by computational experiments and by the theoretical model that the proposed algorithm reduces the parallelization penalty about two times over the basic algorithm for the range of the number of processors (subdomains) considered and the number of grid nodes per subdomain.

Povitsky, A.

1998-01-01

95

J. Parallel Distrib. Comput. 68 (2008) 13891401 Contents lists available at ScienceDirect  

E-print Network

of Illinois at Urbana-Champaign, 1308 W Main Street, Urbana, IL 61801, United States a r t i c l e i n f o.S. Stone), stratton@crhc.uiuc.edu (J.A. Stratton), ueng@crhc.uiuc.edu (S.-Z. Ueng), bsadeghiJ. Parallel Distrib. Comput. 68 (2008) 1389­1401 Contents lists available at ScienceDirect J

Hwu, Wen-mei W.

96

PICASSO, an Experiment for Direct Search of Cold Dark Matter  

NASA Astrophysics Data System (ADS)

There is strong evidence that a large fraction of the matter in the Universe is non-luminous and non-baryonic. The mass components of the Universe are ~4% of baryonic (visible) matter, 23% of cold dark matter and 73% of dark energy. The lightest neutralino, ?, predicted in supersymmetric (SUSY) extensions of the Standard Model (SM) emerges as the most promising candidate for dark matter. The PICASSO experiment is searching for cold dark matter through the direct detection of neutralinos via their spin-dependent interactions with nuclei. The experiment is installed in the Sudbury Neutrino Observatory Laboratory at a depth of 2070 m (6000 mwe). PICASSO makes use of the superheated droplet technique with C4F10 as the active material and searches for ? interactions on 19F. The experimental technique used by PICASSO is reviewed and results of the measurements are presented in terms of limits on the spin-dependent ?-proton and ?-neutron cross sections. The results exclude regions of spin dependent ?-nucleon interaction parameter space. Future phases of PICASSO are briefiy discussed.

Leroy, Claude

2007-11-01

97

Direct dark matter searches - Test of the Big Bounce Cosmology  

E-print Network

We consider the possibility of using dark matter particle's mass and its interaction cross section as a smoking gun signal of the existence of a Big Bounce at the early stage in the evolution of our currently observed universe. A study of dark matter production in the pre-bounce contraction and the post bounce expansion epochs of this universe reveals a new venue for achieving the observed relic abundance of our present universe, in which a significantly smaller amount of dark matter with a smaller cross section is produced and the information about the bounce universe evolution is preserved by the out-of-thermal-equilibrium process. Once the value of dark matter mass and interaction cross section are obtained by direct detection in laboratories, this alternative route becomes a signature prediction of the bounce universe scenario. This leads us to consider a scalar dark matter candidate, which if it is light, has important implications on dark matter searches.

Cheung, Yeuk-Kwan E

2014-01-01

98

Search for Direct CP Violation in $\\Xi$ Hyperon Decay  

E-print Network

Using data collected with the CLEO II detector we have performed a search for direct CP violation in the $\\Xi$ hyperon system. CP violation gives rise to an asymmetry, A, between the parity-violating angular distributions of the decay chains $\\Xi^- \\To \\Lambda pi^-$, $\\Lambda \\To p \\pi^-$ and $\\bar{\\Xi}^+ \\To \\bar{\\Lambda} \\pi^+$, $\\bar{\\Lambda} \\To \\bar{p} \\pi^+$. In the Standard Model, A is expected to be in the range $10^{-4}$ to $10^{-5}$. If CP violation were found at a higher level it could indicate the presence of new physics. We find no evidence for CP violation: A = -0.057 +- 0.064 +- 0.039. We also obtain $A_{\\Xi} = -0.070 +- 0.064 +- 0.045$ and $\\alpha_{\\bar{\\Xi}}= 0.49^{+0.06}_{-0.05} +- 0.10$.

Jaffe, D E; Paar, H P; Potter, E M; Prell, S; Sharma, V; Asner, D M; Eppich, A; Gronberg, J B; Hill, T S; Lange, D J; Morrison, R J; Nelson, H N; Nelson, T K; Roberts, D; Behrens, B H; Ford, W T; Gritsan, A; Krieg, H; Roy, J D; Smith, J G; Alexander, J P; Baker, R; Bebek, C; Berger, B E; Berkelman, K; Boisvert, V; Cassel, David G; Crowcroft, D S; Dickson, M; Von Dombrowski, S; Drell, P S; Ecklund, K M; Ehrlich, R; Foland, A D; Gaidarev, P B; Gibbons, L K; Gittelman, B; Gray, S W; Hartill, D L; Heltsley, B K; Hopman, P I; Kreinick, D L; Lee, T; Liu, Y; Mistry, N B; Ng, C R; Nordberg, E; Ogg, M; Patterson, J R; Peterson, D; Riley, D; Soffer, A; Valant-Spaight, B L; Warburton, A; Ward, C; Athanas, M; Avery, P; Jones, C D; Lohner, M; Prescott, C; Rubiera, A I; Yelton, J; Zheng, J; Brandenburg, G; Briere, R A; Ershov, A; Gao, Y S; Kim, D Y J; Wilson, R; Browder, T E; Li, Y; Rodrguez, J L; Yamamoto, H; Bergfeld, T; Eisenstein, B I; Ernst, J; Gladding, G E; Gollin, G D; Hans, R M; Johnson, E; Karliner, I; Marsh, M A; Palmer, M; Selen, M; Thaler, J J; Edwards, K W; Bellerive, A; Janicek, R; Patel, P M; Sadoff, A J; Ammar, R; Baringer, P; Bean, A; Besson, D; Coppage, D; Davis, R; Kotov, S A; Kravchenko, I V; Kwak, N; Zhou, L; Anderson, S; Kubota, Y; Lee, S J; Mahapatra, R; O'Neill, J J; Poling, R A; Riehle, T; Smith, A; Alam, M S; Athar, S B; Ling, Z; Mahmood, A H; Timm, S; Wappler, F; Anastassov, A; Duboscq, J E; Gan, K K; Gwon, C; Hart, T; Honscheid, K; Kagan, H; Kass, R; Lee, J; Lorenc, J; Schwarthoff, H; Wolf, A; Zoeller, M M; Richichi, S J; Severini, H; Skubic, P L; Undrus, A; Bishai, M; Chen, S; Fast, J; Hinson, J W; Menon, N; Miller, D H; Shibata, E I; Shipsey, I P J; Glenn, S; Kwon, Y; Lyon, A L; Roberts, S; Thorndike, E H; Jessop, C P; Lingel, K; Marsiske, H; Perl, Martin Lewis; Savinov, V; Ugolini, D W; Zhou, X; Coan, T E; Fadeev, V; Korolkov, I Ya; Maravin, Y; Narsky, I; Stroynowski, R; Ye, J; Wlodek, T; Artuso, M; Dambasuren, E; Kopp, S E; Moneti, G C; Mountain, R; Schuh, S; Skwarnicki, T; Stone, S; Titov, A; Viehhauser, G; Wang, J C; Csorna, S E; McLean, K W; Marka, S; Xu, Z; Godang, R; Kinoshita, K; Lai, I C; Pomianowski, P A; Schrenk, S; Bonvicini, G; Cinabro, D; Greene, R; Perera, L P; Zhou, G J; Chan, S; Eigen, G; Lipeles, E; Miller, J S; Schmidtler, M; Shapiro, A; Sun, W M; Urheim, J; Weinstein, A J; Wrthwein, F

2000-01-01

99

Direct CP violation searches in charmless hadronic B meson decays  

Microsoft Academic Search

We search for direct CP violation in charmless hadronic B decays observed in a sample of about 22.7 million BBbar pairs collected with the BABAR detector at the SLAC PEP-II asymmetric-energy e+e- collider. We measure the following charge asymmetries: ACP(B+\\/--->eta'K+\\/-)=-0.11+\\/-0.11+\\/-0.02, ACP(B+\\/--->omegapi+\\/-)=-0.01 + 0.29 - 0.31+\\/-0.03, ACP(B+\\/--->phiK+\\/-)=-0.05+\\/-0.20+\\/-0.03, ACP(B+\\/--->phiK*+\\/-)=-0.43 + 0.36 - 0.30+\\/-0.06, and ACP(B0-->phiK*0)=0.00+\\/-0.27+\\/-0.03.

B. Aubert; D. Boutigny; J.-M. Gaillard; A. Hicheur; Y. Karyotakis; J. P. Lees; P. Robbe; V. Tisserand; A. Palano; A. Pompili; G. P. Chen; J. C. Chen; N. D. Qi; G. Rong; P. Wang; Y. S. Zhu; G. Eigen; B. Stugu; G. S. Abrams; A. W. Borgland; A. B. Breon; D. N. Brown; J. Button-Shafer; R. N. Cahn; A. R. Clark; M. S. Gill; A. V. Gritsan; Y. Groysman; R. G. Jacobsen; R. W. Kadel; J. Kadyk; L. T. Kerth; Yu. G. Kolomensky; J. F. Kral; C. Leclerc; M. E. Levi; G. Lynch; P. J. Oddone; M. Pripstein; N. A. Roe; A. Romosan; M. T. Ronan; V. G. Shelkov; A. V. Telnov; W. A. Wenzel; P. G. Bright-Thomas; T. J. Harrison; C. M. Hawkes; D. J. Knowles; S. W. O'Neale; R. C. Penny; A. T. Watson; N. K. Watson; T. Deppermann; K. Goetzen; H. Koch; M. Kunze; B. Lewandowski; K. Peters; H. Schmuecker; M. Steinke; N. R. Barlow; W. Bhimji; N. Chevalier; P. J. Clark; W. N. Cottingham; B. Foster; C. Mackay; F. F. Wilson; K. Abe; C. Hearty; T. S. Mattison; J. A. McKenna; D. Thiessen; S. Jolly; J. A. McKenna; V. E. Blinov; A. D. Bukin; D. A. Bukin; A. R. Buzykaev; V. B. Golubev; V. N. Ivanchenko; A. A. Korol; E. A. Kravchenko; A. P. Onuchin; S. I. Serednyakov; I. Skovpen; V. I. Telnov; A. N. Yushkov; M. Chao; D. Kirkby; A. J. Lankford; M. Mandelkern; S. McMahon; D. P. Stoker; K. Arisaka; C. Buchanan; S. Chun; D. B. MacFarlane; S. Prell; G. Raven; V. Sharma; C. Campagnari; B. Dahmes; P. A. Hart; N. Kuznetsova; S. L. Levy; A. Lu; J. D. Richman; W. Verkerke; J. Beringer; A. M. Eisner; M. Grothe; C. A. Heusch; W. S. Lockman; T. Pulliam; T. Schalk; A. Seiden; M. Turri; W. Walkowiak; D. C. Williams; M. G. Wilson; E. Chen; G. P. Dubois-Felsmann; A. Dvoretskii; D. G. Hitlin; J. Oyang; F. C. Porter; A. Ryd; A. Samuel; R. Y. Zhu; T. L. Geld; S. Jayatilleke; G. Mancinelli; B. T. Meadows; M. D. Sokolo; T. Barillari; P. Bloom; M. O. Dima; W. T. Ford; A. Olivas; P. Rankin; J. Roy; J. G. Smith; W. C. van Hoek; J. Blouw; J. L. Harton; M. Krishnamurthy; A. Soer; W. H. Toki; R. J. Wilson; J. Zhang; T. Brandt; M. Sokoloff; T. Barillari; P. Bloom; S. Fahey; D. Johnson; U. Nauenberg; S. Sen; J. Smith; D. Wagner; A. Soffer; J. Zhang; J. Brose; T. Colberg; M. Dickopp; R. Dubitzky; A. Hauke; E. Maly; R. Mller-Pfefferkorn; S. Otto; K. Schubert; R. Schwierz; B. Spaan; L. Wilden; D. Bernard; G. Bonneaud; F. Brochard; J. Cohen-Tanugi; S. Ferrag; E. Roussot; S. TJampens; Ch. Thiebaux; G. Vasileiadis; M. Verderi; A. Anjomshoaa; R. Bernet; A. Khan; D. Lavin; F. Muheim; S. Playfer; J. Swain; J. Tinslay; M. Falbo; C. Borean; C. Bozzi; S. Dittongo; L. Piemontese; E. Treadwell; F. Anulli; R. Baldini-Ferroli; A. Calcaterra; R. de Sangro; D. Falciai; G. Finocchiaro; P. Patteri; I. Peruzzi; M. Piccolo; Y. Xie; A. Zallo; S. Bagnasco; A. Buzzo; R. Contri; G. Crosetti; M. Lo Vetere; M. Macri; M. Monge; S. Passaggio; F. Pastore; C. Patrignani; M. Piccolo; E. Robutti; A. Santroni; S. Tosi; M. Morii; R. Bartoldus; U. Mallik; J. Cochran; H. Crawley; P.-A. Fischer; J. Lamsa; W. Meyer; E. Rosenberg; G. Grosdidier; C. Hast; A. Hcker; H. Lacker; S. Laplace; V. Lepeltier; A. Lutz; S. Plaszczynski; M. Schune; S. Trincaz-Duvoid; G. Wormser; R. Bionta; V. Brigljevi?; D. Lange; M. Mugge; K. van Bibber; D. Wright; A. Bevan; J. Fry; E. Gabathuler; R. Gamet; M. George; M. Kay; D. Payne; R. Sloane; C. Touramanis; M. Aspinwall; D. Bowerman; P. Dauncey; U. Egede; I. Eschrich; N. Gunawardane; J. Nash; P. Sanders; D. Smith; D. Azzopardi; J. Back; P. Dixon; P. Harrison; R. Potter; H. Shorthouse; P. Strother; P. Vidal; G. Cowan; S. George; M. Green; A. Kurup; C. Marker; P. McGrath; T. McMahon; S. Ricciardi; F. Salvatore; I. Scott; G. Vaitsas; D. Brown; C. Davis; J. Allison; R. Barlow; J. Boyd; A. Forti; J. Fullwood; F. Jackson; G. Lafferty; N. Savvas; J. Weatherall; J. Williams; A. Farbin; A. Jawahery; V. Lillard; J. Olsen; D. Roberts; J. Schieck; G. Blaylock; S. Hertzbach; R. Kofler; V. Koptchev; T. Moore; H. Staengle; S. Willocq; B. Brau; R. Cowan; G. Sciolla; F. Taylor; R. Yamamoto; M. Milek; P. Patel; F. Palombo; J. Bauer; L. Cremaldi; V. Eschenburg; R. Kofler; J. Reidy; D. Sanders; D. Summers; J. Martin; J. Nief; R. Seitz; P. Taras; V. Zacek; H. Nicholson; C. Sutton; C. Cartaro; N. Cavallo; G. De Nardo; F. Fabozzi; C. Gatto; L. Lista; P. Paolucci; D. Piccolo; C. Sciacca; J. LoSecco; J. Alsmiller; T. Gabriel; T. Handler; J. Brau; R. Frey; E. Grauges; M. Iwasaki; N. Sinev; D. Strom; F. Colecchia; F. Dal Corso; A. Dorigo; F. Galeazzi; M. Margoni; G. Michelon; M. Morandin; M. Posocco; M. Rotondo; F. Simonetto; R. Stroili; E. Torassa; C. Voci; M. Benayoun; H. Briand; J. Chauveau; P. David; Ch. de la Vaissire; L. Del Buono; O. Hamon; F. Le Diberder; Ph. Leruste; J. Ocariz; L. Roos; J. Stark; P. Manfredi; V. Re; V. Speziali; E. Frank; L. Gladney; Q. Guo; J. Panetta; C. Angelini; G. Batignani; S. Bettarini; M. Bondioli; M. Carpinelli; F. Forti; M. Giorgi; A. Lusiani; F. Martinez-Vidal

2002-01-01

100

Light magnetic dark matter in direct detection searches  

NASA Astrophysics Data System (ADS)

We study a fermionic Dark Matter particle carrying magnetic dipole moment and analyze its impact on direct detection experiments. In particular we show that it can accommodate the DAMA, CoGeNT and CRESST experimental results. Assuming conservative bounds, this candidate is shown not to be ruled out by the CDMS, XENON and PICASSO experiments. We offer an analytic understanding of how the long-range interaction modifies the experimental allowed regions, in the cross section versus Dark Matter mass parameter space, with respect to the typically assumed contact interaction. Finally, in the context of a symmetric Dark Matter sector, we determine the associated thermal relic density, and further provide relevant constraints imposed by indirect searches and colliders.

Del Nobile, Eugenio; Kouvaris, Chris; Panci, Paolo; Sannino, Francesco; Virkajrvi, Jussi

2012-08-01

101

A Directional & Adaptive Diamond Search by Adaptive Pattern Switching with a Predicted Motion Vector  

Microsoft Academic Search

ABSTRACT Wepropose,a simple ,fast block-matching ,algorithm (BMA) based ,on the ,direction of the ,predicted motion vector called directional & adaptive diamond search by adaptive pattern switching (DADS-APS). The proposal method has two sequential search steps, including 1) an initial search, and 2) a refinement search for the local area. Adaptive pattern switching (APS) is proposed,for the initial search and a

Jong-ho Kim; Byung-gyu Kim; Suk-kyu Song; Chang-sik Cho

2006-01-01

102

A Direct Imaging Study to Search for and to Characterize Planetary Mass Companions  

NASA Astrophysics Data System (ADS)

We present preliminary results from two parallel programs to search for new substellar companions to nearby, young M-stars and to characterize the atmospheres of known planetary mass and temperature substellar companions. For the M-star survey, we are analyzing high angular resolution archival data on systems within 15pc, complementing a subset with well-determined young ages based on measurements of several age indicators. The results include stellar and substellar companion candidates, which we are currently pursuing with follow-up second epoch images. The characterization component of the project involves using LBT LMIRCam and MMT ARIES direct imaging and spectroscopy data to investigate the atmospheres of known young substellar companions with masses overlapping the planetary regime. These atmospheric studies will represent an analogous comparison to the atmospheres of young imaged planets, and provide a means to fundamentally test evolutionary models, enhancing our understanding of the overall substellar population.

Ward-Duong, K.; Patience, J.; De Rosa, R. J.; Rajan, A.; Hinz, P.; Skemer, A.; Morzinski, K.; Males, J.; Close, L. M.; McCarthy, D. W.; Kulesa, C.

2014-01-01

103

Scalable High Performance Computing: Direct and Large-Eddy Turbulent Flow Simulations Using Massively Parallel Computers  

NASA Technical Reports Server (NTRS)

This final report contains reports of research related to the tasks "Scalable High Performance Computing: Direct and Lark-Eddy Turbulent FLow Simulations Using Massively Parallel Computers" and "Devleop High-Performance Time-Domain Computational Electromagnetics Capability for RCS Prediction, Wave Propagation in Dispersive Media, and Dual-Use Applications. The discussion of Scalable High Performance Computing reports on three objectives: validate, access scalability, and apply two parallel flow solvers for three-dimensional Navier-Stokes flows; develop and validate a high-order parallel solver for Direct Numerical Simulations (DNS) and Large Eddy Simulation (LES) problems; and Investigate and develop a high-order Reynolds averaged Navier-Stokes turbulence model. The discussion of High-Performance Time-Domain Computational Electromagnetics reports on five objectives: enhancement of an electromagnetics code (CHARGE) to be able to effectively model antenna problems; utilize lessons learned in high-order/spectral solution of swirling 3D jets to apply to solving electromagnetics project; transition a high-order fluids code, FDL3DI, to be able to solve Maxwell's Equations using compact-differencing; develop and demonstrate improved radiation absorbing boundary conditions for high-order CEM; and extend high-order CEM solver to address variable material properties. The report also contains a review of work done by the systems engineer.

Morgan, Philip E.

2004-01-01

104

Co-ordination of directional overcurrent protection with load current for parallel feeders  

SciTech Connect

Directional phase overcurrent relays are commonly applied at the receiving ends of parallel feeders or transformer feeders. Their purpose is to ensure full discrimination of main or back-up power system overcurrent protection for a fault near the receiving end of one feeder. This paper reviews this type of relay application and highlights load current setting constraints for directional protection. Such constraints have not previously been publicized in well-known text books. A directional relay current setting constraint that is suggested in some text books is based purely on thermal rating considerations for older technology relays. This constraint may not exist with modern numerical relays. In the absence of any apparent constraint, there is a temptation to adopt lower current settings with modern directional relays in relation to reverse load current at the receiving ends of parallel feeders. This paper identifies the danger of adopting very low current settings without any special relay feature to ensure protection security with load current during power system faults. A system incident recorded by numerical relays is also offered to highlight this danger. In cases where there is a need to infringe the identified constraints an implemented and testing relaying technique is proposed.

Wright, J.W.; Lloyd, G.; Hindle, P.J. [Alstom, Inc., Stafford (United Kingdom). T and D Protection and Control

1999-11-01

105

Serial and parallel processes in eye movement control: current controversies and future directions.  

PubMed

In this editorial for the special issue on serial and parallel processing in reading we explore the background to the current debate concerning whether the word recognition processes in reading are strictly serial-sequential or take place in an overlapping parallel fashion. We consider the history of the controversy and some of the underlying assumptions, together with an analysis of the types of evidence and arguments that have been adduced to both sides of the debate, concluding that both accounts necessarily presuppose some weakening of, or elasticity in, the eye-mind assumption. We then consider future directions, both for reading research and for scene viewing, and wrap up the editorial with a brief overview of the following articles and their conclusions. PMID:23477327

Murray, Wayne S; Fischer, Martin H; Tatler, Benjamin W

2013-01-01

106

democrite-00023778,version1-11Apr2005 DIRECT SEARCH FOR WIMP DARK MATTER  

E-print Network

democrite-00023778,version1-11Apr2005 DIRECT SEARCH FOR WIMP DARK MATTER J. GASCON Institut de the experimental aspects of the direct search for WIMP dark matter. In this search, one looks in a terrestrial observations is that our Galaxy could be immersed in a halo of heavy Dark Matter particles of a fundamentally

Paris-Sud XI, Université de

107

Direct and Inverse Kinematics of a Novel Tip-Tilt-Piston Parallel Manipulator  

NASA Technical Reports Server (NTRS)

Closed-form direct and inverse kinematics of a new three degree-of-freedom (DOF) parallel manipulator with inextensible limbs and base-mounted actuators are presented. The manipulator has higher resolution and precision than the existing three DOF mechanisms with extensible limbs. Since all of the manipulator actuators are base-mounted; higher payload capacity, smaller actuator sizes, and lower power dissipation can be obtained. The manipulator is suitable for alignment applications where only tip, tilt, and piston motions are significant. The direct kinematics of the manipulator is reduced to solving an eighth-degree polynomial in the square of tangent of half-angle between one of the limbs and the base plane. Hence, there are at most 16 assembly configurations for the manipulator. In addition, it is shown that the 16 solutions are eight pairs of reflected configurations with respect to the base plane. Numerical examples for the direct and inverse kinematics of the manipulator are also presented.

Tahmasebi, Farhad

2004-01-01

108

Direct Searches for Scalar Leptoquarks at the Run II Tevatron  

SciTech Connect

This dissertation sets new limits on the mass of the scalar leptoquark from direct searches carried out at the Run II CDF detector using data from March 2001 to October 2003. The data analyzed has a total time-integrated measured luminosity of 198 pb{sup -1} of p{bar p} collisions with {radical}s = 1.96 TeV. Leptoquarks are assumed to be pair-produced and to decay into a lepton and a quark of the same generation. They consider two possible leptoquark decays: (1) {beta} = BR(LQ {yields} {mu}q) = 1.0, and (2) {beta} = BR(LQ {yields} {mu}q) = 0.5. For the {beta} = 1 channel, they focus on the signature represented by two isolated high-p{sub T} muons and two isolated high-p{sub T} jets. For the {beta} = 1/2 channel, they focus on the signature represented by one isolated high-p{sub T} muon, large missing transverse energy, and two isolated high-p{sub T} jets. No leptoquark signal is experimentally detected for either signature. Using the next to leading order theoretical cross section for scalar leptoquark production in p{bar p} collisions [1], they set new mass limits on second generation scalar leptoquarks. They exclude the existence of second generation scalar leptoquarks with masses below 221(175) GeV/c{sup 2} for the {beta} = 1(1/2) channels.

Ryan, Daniel E.; /Tufts U.

2004-11-01

109

Direct Imaging Searches with the Apodizing Phase Plate Coronagraph  

NASA Astrophysics Data System (ADS)

The sensitivity of direct imaging searches for extrasolar planets is limited by the presence of diffraction rings from the primary star. Coronagraphs are angular filters that minimise these diffraction structures whilst allowing light from faint companions to shine through. The Apodizing Phase Plate (APP; Kenworthy 2007) coronagraph is a simple pupil plane optic that suppresses diffraction over a 180 degree region around each star simultaneously, providing easy beam switching observations and requiring no time consuming optical alignment at the telescope. We will present our results on using the APP at the Very Large Telescope in surveys for extrasolar planets around A/F and debris disk hosting stars in the L' band (3.8 microns) in the Southern Hemisphere, where we reach a contrast of 12 magnitudes at 0.5 arcseconds (Meshkat 2013). In Leiden, we are also developing the next generation of broadband achromatic coronagraphs that can simultaneously image both sides of the star using Vector APPs (Snik 2012, Otten 2012). Recent laboratory results showing the potential of this technology for future ELTs will also be presented.

Kenworthy, M.; Meshkat, T.; Otten, , G.; Codona, J.

2014-03-01

110

Streaming Similarity Search over One Billion Tweets Using Parallel Locality-Sensitive Hashing  

E-print Network

Finding nearest neighbors has become an important operation on databases, with applications to text search, multimedia indexing, and many other areas. One popular algorithm for similarity search, especially for high ...

Sundaram, Narayanan

111

Fabrication of Si-nozzles for parallel mechano-electrospinning direct writing  

NASA Astrophysics Data System (ADS)

Nozzles with micro-scale orifices drive high-resolution printing techniques for generating micro- to nano-scale droplets/lines. This paper presents the fabrication and application of Si-nozzles in mechano-electrospinning (MES). The fabrication process mainly consists of photolithography, Au deposition, inductively coupled plasma, and polydimethylsiloxane encapsulation. The 6 wt% polyethylene oxide solution is adopted to study the electrospinning behaviour and the relations between fibre diameter and process parameters in MES. A fibre grid with 250 m spacing is able to be direct written, and the diameters are less than 3 m. To improve the printing efficiency, positioning accuracy and flexibility, a rotatable multi-nozzle is adopted. The distance between parallel lines reduces sharply from 4.927 to 0.308 mm with the rotating angle increasing from 0 to 87, and the fibre grids with tunable distance are achieved. This method paves the way for fabrication of addressable Si-nozzle array in parallel MES direct writing.

Pan, Yanqiao; Huang, YongAn; Bu, Ningbin; Yin, Zhouping

2013-06-01

112

Parallel computing of a digital hologram and particle searching for microdigital-holographic particle-tracking velocimetry.  

PubMed

We have developed a parallel algorithm for microdigital-holographic particle-tracking velocimetry. The algorithm is used in (1) numerical reconstruction of a particle image computer using a digital hologram, and (2) searching for particles. The numerical reconstruction from the digital hologram makes use of the Fresnel diffraction equation and the FFT (fast Fourier transform), whereas the particle search algorithm looks for local maximum graduation in a reconstruction field represented by a 3D matrix. To achieve high performance computing for both calculations (reconstruction and particle search), two memory partitions are allocated to the 3D matrix. In this matrix, the reconstruction part consists of horizontally placed 2D memory partitions on the x-y plane for the FFT, whereas, the particle search part consists of vertically placed 2D memory partitions set along the z axes. Consequently, the scalability can be obtained for the proportion of processor elements, where the benchmarks are carried out for parallel computation by a SGI Altix machine. PMID:17230248

Satake, Shin-ichi; Kanamori, Hiroyuki; Kunugi, Tomoaki; Sato, Kazuho; Ito, Tomoyoshi; Yamamoto, Keisuke

2007-02-01

113

Parallel computing of a digital hologram and particle searching for microdigital-holographic particle-tracking velocimetry  

SciTech Connect

We have developed a parallel algorithm for microdigital-holographic particle-tracking velocimetry. The algorithm is used in (1) numerical reconstruction of a particle image computer using a digital hologram, and (2) searching for particles. The numerical reconstruction from the digital hologram makes use of the Fresnel diffraction equation and the FFT (fast Fourier transform),whereas the particle search algorithm looks for local maximum graduation in a reconstruction field represented by a 3D matrix. To achieve high performance computing for both calculations (reconstruction and particle search), two memory partitions are allocated to the 3D matrix. In this matrix, the reconstruction part consists of horizontally placed 2D memory partitions on the x-y plane for the FFT, whereas, the particle search part consists of vertically placed 2D memory partitions set along the z axes.Consequently, the scalability can be obtained for the proportion of processor elements,where the benchmarks are carried out for parallel computation by a SGI Altix machine.

Satake, Shin-ichi; Kanamori, Hiroyuki; Kunugi, Tomoaki; Sato, Kazuho; Ito, Tomoyoshi; Yamamoto, Keisuke

2007-02-01

114

A direct search for new charged heavy leptons at LEP  

Microsoft Academic Search

Results are presented from a search for a new charged heavy lepton in e+e- annihilation. The data were taken with the OPAL detector at LEP during a scan of the Z0 resonance. Two independent search techniques were used, one looking for events with large missing energy and missing momentum transverse to the beam, and the other for events with isolated

M. Z. Akrawy; Gideon Alexander; J. Allison; P. P. Allport; K. J. Anderson; J. C. Armitage; Geoffrey T J Arnison; P. Ashton; Georges Azuelos; J. T. M. Baines; A. H. Ball; J. Banks; G. J. Barker; R. J. Barlow; J Richard Batley; G. Bavaria; F. Beck; K. W. Bell; G. Bella; Siegfried Bethke; O. Biebel; I. J. Bloddworth; P. Bock; Horst Breuker; R. M. Brown; R. Brun; A. Buijs; Helfried J Burckhart; P. Capiluppi; R. K. Carnegie; A. A. Carter; J. R. Carter; C. Y. Chang; D. G. Charlton; J. T. M. Chrin; I. Cohen; J. E. Conboy; M. Couch; M. Coupland; M. Cuffiani; S. Dado; G. M. Dallavalle; O. W. Davies; M. M. Deninno; A. Dieckmann; Michael Dittmar; M. S. Dixit; D. Duchesneau; E. Duchovni; I. P. Duerdoth; D J P Dumas; H. El Mamouni; P. A. Elcombe; P. G. Estabrooks; E. Etzion; Franco Luigi Fabbri; Philippe Farthouat; H. M. Fischer; D. G. Fong; M. T. French; C. Fukunaga; B. Gandois; O. Ganel; J. W. Gary; N. I. Geddes; C. N. P. Gee; C. Geich-Gimbel; S. W. Gensler; F. X. Gentit; G. Giacomelli; W. R. Gibson; James D Gillies; J. Goldberg; M. J. Goodrick; W. Gorn; D. Granite; E. Gross; P. Grosse-Wiesmann; Jacob Grunhaus; H. Hagedorn; J. Hagemann; M. Hansroul; C. K. Hargrove; J. Hart; P. M. Hattersley; D. Hatzifotiadou; M. Hauschild; C. M. Hawkes; E. Heflin; J. Heintze; Richard J Hemingway; R. D. Heuer; J. C. Hill; S. J. Hillier; P. S. Hinde; C. Ho; J. D. Hobbs; P. R. Hobson; D. Hochman; B. Holl; R James Homer; S. R. Hou; C. P. Howarth; R. E. Hughes-Jones; P. Igo-Kemenes; M. Imori; D. C. Imrie; A. Jawahery; P. W. Jeffreys; H. Jeremie; Martin Paul Jimack; E. Jin; M. Jobes; R. W. L. Jones; P. Jovanovic; D A Karlen; K. Kawagoe; T. Kawamoto; R. G. Kellogg; B. W. Kennedy; C. Kleinwort; D. E. Klem; G. Knop; T. Kobayashi; L. Kpke; T. P. Kokott; M. Koshiba; R V Kowalewski; H. Kreutzmann; J. von Krogh; J. Kroll; P. Kyberd; G. D. Lafferty; F. Lamarche; W. J. Larson; M. M. B. Lasota; J. G. Layter; P. Le Du; P. Leblanc; Daniel Lellouch; P. Lennert; L. Lessard; L. Levinson; S. L. Lloyd; F. K. Loebinger; J. M. Lorah; B. Lorazo; Michael J Losty; J. Ludwig; J. Ma; A. A. MacBeth; M. Mannelli; S. Marcellini; G. Maringer; J. P. Martin; T. Mashimo; P. Mttig; U. Maur; T. J. McMahon; A. C. McPherson; F. Meijers; D. Menszner; F. S. Merritt; H. Mes; A. Michellini; R. P. Middleton; G. Mikenberg; D. J. Miller; C. Milstene; M. Minowa; W. Mohr; A. Montanari; T. Mori; M. W. Moss; A. Muller; P. G. Murphy; W. J. Murray; B. Nellen; H. H. Nguyen; M. Nozaki; A. J. P. O'Dowd; S. W. O'Neale; B P O'Neill; F. G. Oakham; F. Odorici; M. Ogg; H. Oh; M. J. Oreglia; S. Orito; G. N. Patrick; S. J. Pawley; J. E. Pilcher; J. L. Pinfold; D. E. Plane; B. Poli; A. Possoz; A. Pouladdej; T. W. Pritchard; G. Quast; J. Raab; M. W. Redmond; D. L. Rees; M. Regimbald; K. Riles; C. M. Roach; F. Roehner; A. Rollnik; J. M. Roney; A. M. Rossi; P. Routenburg; K. Runge; O. Runolfsson; S. Sanghera; R. A. Sansum; M. Sasaki; B. J. Saunders; A. D. Schaile; O. Schaile; W. Schappert; P. Scharff-Hansen; H. von der Schmitt; S. Schreiber; J. Schwarz; A. Shapira; B. C. Shen; P. Sherwood; A. Simon; G. P. Siroli; A M Smith; A. M. Smith; T. J. Smith; G. A. Snow; E. J. Spreadbury; R. W. Springer; M. Sproston; K. Stephens; J. Steuerer; H. E. Stier; R. Strhmer; D. Strom; H. Takeda; T. Takeshita; T. Tsukamoto; M. F. Turner; G. Tysarczyk; D. van den Plas; G. J. Vandalen; C. J. Virtue; A. Wagner; C. Wahl; H. Wang; C. P. Ward; D. R. Ward; J. Waterhouse; P. M. Watkins; A. T. Watson; N. K. Watson; M. Weber; S. Weisz; N. Wermes; M. Weymann; G. W. Wilson; J. A. Wilson; I. Wingerter; V.-H. Winterer; N. C. Wood; S. Wotton; B. Wuensch; T. R. Wyatt; R. Yaari; H. Yamashita; Y. Yang; G. Yekutieli; W. Zeuner; G. T. Zorn; S. Zylberajch

1990-01-01

115

A DIRECT METHOD TO DETERMINE THE PARALLEL MEAN FREE PATH OF SOLAR ENERGETIC PARTICLES WITH ADIABATIC FOCUSING  

SciTech Connect

The parallel mean free path of solar energetic particles (SEPs), which is determined by physical properties of SEPs as well as those of solar wind, is a very important parameter in space physics to study the transport of charged energetic particles in the heliosphere, especially for space weather forecasting. In space weather practice, it is necessary to find a quick approach to obtain the parallel mean free path of SEPs for a solar event. In addition, the adiabatic focusing effect caused by a spatially varying mean magnetic field in the solar system is important to the transport processes of SEPs. Recently, Shalchi presented an analytical description of the parallel diffusion coefficient with adiabatic focusing. Based on Shalchi's results, in this paper we provide a direct analytical formula as a function of parameters concerning the physical properties of SEPs and solar wind to directly and quickly determine the parallel mean free path of SEPs with adiabatic focusing. Since all of the quantities in the analytical formula can be directly observed by spacecraft, this direct method would be a very useful tool in space weather research. As applications of the direct method, we investigate the inherent relations between the parallel mean free path and various parameters concerning physical properties of SEPs and solar wind. Comparisons of parallel mean free paths with and without adiabatic focusing are also presented.

He, H.-Q.; Wan, W., E-mail: hqhe@mail.iggcas.ac.cn, E-mail: wanw@mail.iggcas.ac.cn [Beijing National Observatory of Space Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029 (China)

2012-03-01

116

SIMPLE-icity in Direct Dark Matter Searches  

SciTech Connect

SIMPLE is the European WIMP search based on Superheated Droplet Detectors (SDDs). An SDD consists of an emulsion of metastable liquid droplets in an organic gel, each of which operates on the same principle of the bubble chamber.

Giuliani, F.; Morlat, T.; Ramos, A. R.; Girard, T. A.; Felizardo da Costa, M.; Marques, J. G.; Martins, R. C.; Miley, Harry S.; Limagne, D.; Waysand, G.

2007-11-01

117

Direct Spatial Search on Pictorial Databases Using Packed R-Trees  

Microsoft Academic Search

Pictorial databases require efficient and direct spatial search based on the analog form of spatial objects and relationships instead of search based on some cumbersome alphanumeric encodings of the pictures. R-trees (two- dimensional B-trees) are excellent devices for indexing spatial objects and relationships found on pictures. Their most important feature is that they provide high level object oriented search rather

Nick Roussopoulos; Daniel Leifker

1985-01-01

118

APHID: Asynchronous Parallel Game-Tree Search Mark G. Brockington and Jonathan Schaeffer  

E-print Network

. APHID yields better speedups than synchronous search methods for an Othello and a checkers program-sum games with perfect information, such as chess, Othello1 and checkers, are programmed using the same the search depth and the relative strength of chess, Othello and checkers programs [8]. Thus, programs

Schaeffer, Jonathan

119

Large-scale parallel arrays of silicon nanowires via block copolymer directed self-assembly  

NASA Astrophysics Data System (ADS)

Extending the resolution and spatial proximity of lithographic patterning below critical dimensions of 20 nm remains a key challenge with very-large-scale integration, especially if the persistent scaling of silicon electronic devices is sustained. One approach, which relies upon the directed self-assembly of block copolymers by chemical-epitaxy, is capable of achieving high density 1 : 1 patterning with critical dimensions approaching 5 nm. Herein, we outline an integration-favourable strategy for fabricating high areal density arrays of aligned silicon nanowires by directed self-assembly of a PS-b-PMMA block copolymer nanopatterns with a L0 (pitch) of 42 nm, on chemically pre-patterned surfaces. Parallel arrays (5 106 wires per cm) of uni-directional and isolated silicon nanowires on insulator substrates with critical dimension ranging from 15 to 19 nm were fabricated by using precision plasma etch processes; with each stage monitored by electron microscopy. This step-by-step approach provides detailed information on interfacial oxide formation at the device silicon layer, the polystyrene profile during plasma etching, final critical dimension uniformity and line edge roughness variation nanowire during processing. The resulting silicon-nanowire array devices exhibit Schottky-type behaviour and a clear field-effect. The measured values for resistivity and specific contact resistance were ((2.6 +/- 1.2) 105 ?cm) and ((240 +/- 80) ?cm2) respectively. These values are typical for intrinsic (un-doped) silicon when contacted by high work function metal albeit counterintuitive as the resistivity of the starting wafer (~10 ?cm) is 4 orders of magnitude lower. In essence, the nanowires are so small and consist of so few atoms, that statistically, at the original doping level each nanowire contains less than a single dopant atom and consequently exhibits the electrical behaviour of the un-doped host material. Moreover this indicates that the processing successfully avoided unintentional doping. Therefore our approach permits tuning of the device steps to contact the nanowires functionality through careful selection of the initial bulk starting material and/or by means of post processing steps e.g. thermal annealing of metal contacts to produce high performance devices. We envision that such a controllable process, combined with the precision patterning of the aligned block copolymer nanopatterns, could prolong the scaling of nanoelectronics and potentially enable the fabrication of dense, parallel arrays of multi-gate field effect transistors.Extending the resolution and spatial proximity of lithographic patterning below critical dimensions of 20 nm remains a key challenge with very-large-scale integration, especially if the persistent scaling of silicon electronic devices is sustained. One approach, which relies upon the directed self-assembly of block copolymers by chemical-epitaxy, is capable of achieving high density 1 : 1 patterning with critical dimensions approaching 5 nm. Herein, we outline an integration-favourable strategy for fabricating high areal density arrays of aligned silicon nanowires by directed self-assembly of a PS-b-PMMA block copolymer nanopatterns with a L0 (pitch) of 42 nm, on chemically pre-patterned surfaces. Parallel arrays (5 106 wires per cm) of uni-directional and isolated silicon nanowires on insulator substrates with critical dimension ranging from 15 to 19 nm were fabricated by using precision plasma etch processes; with each stage monitored by electron microscopy. This step-by-step approach provides detailed information on interfacial oxide formation at the device silicon layer, the polystyrene profile during plasma etching, final critical dimension uniformity and line edge roughness variation nanowire during processing. The resulting silicon-nanowire array devices exhibit Schottky-type behaviour and a clear field-effect. The measured values for resistivity and specific contact resistance were ((2.6 +/- 1.2) 105 ?cm) and ((240 +/- 80) ?cm2) respectively. These values are typic

Farrell, Richard A.; Kinahan, Niall T.; Hansel, Stefan; Stuen, Karl O.; Petkov, Nikolay; Shaw, Matthew T.; West, Laetitia E.; Djara, Vladimir; Dunne, Robert J.; Varona, Olga G.; Gleeson, Peter G.; Jung, Soon-Jung; Kim, Hye-Young; Kole?nik, Maria M.; Lutz, Tarek; Murray, Christopher P.; Holmes, Justin D.; Nealey, Paul F.; Duesberg, Georg S.; Krsti?, Vojislav; Morris, Michael A.

2012-05-01

120

Communication Effects of Advertising versus Direct Experience When Both Search and Experience Attributes Are Present  

Microsoft Academic Search

Previous research has predicted that direct product experience will be superior to advertising in communicating information about products. In experiment 1 of the present study, claims about search attributes were better recognized and beliefs about search attributes were more accessible and more confidently held after exposure to ads in comparison with direct experience of two inexpensive packaged products. Experiment 2

Alice A. Wright

1995-01-01

121

Direct search method for solving economic dispatch problem considering transmission capacity constraints  

Microsoft Academic Search

This paper develops an efficient and practical approach for solving the economic dispatch (ED) problem considering transmission capacity constraints. Direct search method (DSM) is chosen to handle a number of inequality and equality constraints and units with any kind of fuel costs functions. For improving the performance of direct search procedure, a novel strategy with multi-level convergence is incorporated in

Chun-Lung Chen; Nanming Chen

2001-01-01

122

Experimental Studies of the Interaction Between a Parallel Shear Flow and a Directionally-Solidifying Front  

NASA Technical Reports Server (NTRS)

It has long been recognized that flow in the melt can have a profound influence on the dynamics of a solidifying interface and hence the quality of the solid material. In particular, flow affects the heat and mass transfer, and causes spatial and temporal variations in the flow and melt composition. This results in a crystal with nonuniform physical properties. Flow can be generated by buoyancy, expansion or contraction upon phase change, and thermo-soluto capillary effects. In general, these flows can not be avoided and can have an adverse effect on the stability of the crystal structures. This motivates crystal growth experiments in a microgravity environment, where buoyancy-driven convection is significantly suppressed. However, transient accelerations (g-jitter) caused by the acceleration of the spacecraft can affect the melt, while convection generated from the effects other than buoyancy remain important. Rather than bemoan the presence of convection as a source of interfacial instability, Hurle in the 1960s suggested that flow in the melt, either forced or natural convection, might be used to stabilize the interface. Delves considered the imposition of both a parabolic velocity profile and a Blasius boundary layer flow over the interface. He concluded that fast stirring could stabilize the interface to perturbations whose wave vector is in the direction of the fluid velocity. Forth and Wheeler considered the effect of the asymptotic suction boundary layer profile. They showed that the effect of the shear flow was to generate travelling waves parallel to the flow with a speed proportional to the Reynolds number. There have been few quantitative, experimental works reporting on the coupling effect of fluid flow and morphological instabilities. Huang studied plane Couette flow over cells and dendrites. It was found that this flow could greatly enhance the planar stability and even induce the cell-planar transition. A rotating impeller was buried inside the sample cell, driven by an outside rotating magnet, in order to generate the flow. However, it appears that this was not a well-controlled flow and may also have been unsteady. In the present experimental study, we want to study how a forced parallel shear flow in a Hele-Shaw cell interacts with the directionally solidifying crystal interface. The comparison of experimental data show that the parallel shear flow in a Hele-Shaw cell has a strong stabilizing effect on the planar interface by damping the existing initial perturbations. The flow also shows a stabilizing effect on the cellular interface by slightly reducing the exponential growth rate of cells. The left-right symmetry of cells is broken by the flow with cells tilting toward the incoming flow direction. The tilting angle increases with the velocity ratio. The experimental results are explained through the parallel flow effect on lateral solute transport. The phenomenon of cells tilting against the flow is consistent with the numerical result of Dantzig and Chao.

Zhang, Meng; Maxworthy, Tony

1999-01-01

123

Design and analysis of a nondeterministic parallel breadth-first search algorithm  

E-print Network

I have developed a multithreaded implementation of breadth-first search (BFS) of a sparse graph using the Cilk++ extensions to C++. My PBFS program on a single processor runs as quickly as a standard C++ breadth-first ...

Schardl, Tao Benjamin

2010-01-01

124

Sequential and Parallel Variable Neighborhood Search Algorithms for Job Shop Scheduling  

Microsoft Academic Search

Variable Neighborhood Search (VNS) is a recently invented metaheuristic to use in solving combinatorial optimization problems\\u000a in which a systematic change of neighborhood with a local search is carried out. However, as happens with other meta-heuristics,\\u000a it sometimes takes long time to reach useful solutions whilst solving some sort of hard and large scale combinatorial problems\\u000a such as job shop

Mehmet Emin Aydin; Mehmet Sevkli

2008-01-01

125

85.15 Nonlinear Inversion by Direct Search Using the  

E-print Network

Research School of Earth Sciences, Australian National University, Canberra, Australia. 1. Background of models collected, e.g., on resolution and trade-offs. The search algorithm is in the same class, Committee on Education. All rights of reproduction in any form reserved. 35 #12;36 Sambridge FIGURE 1

Sambridge, Malcolm

126

HYPER-HEURISTICS: AN EMERGING DIRECTION IN MODERN SEARCH TECHNOLOGY  

Microsoft Academic Search

This chapter introduces and overviews an emerging methodology in search and optimisation. One of the key aims of these new approaches, which have been termed hyper-heuristics, is to raise the level of generality at which optimisation systems can operate. An objective is that hyper-heuristics will lead to more general systems that are able to handle a wide range of problem

Edmund Burke; Emma Hart; G raham Kendall; Peter Ross; Sonia Schulenburg

2003-01-01

127

Large-scale parallel arrays of silicon nanowires via block copolymer directed self-assembly.  

PubMed

Extending the resolution and spatial proximity of lithographic patterning below critical dimensions of 20 nm remains a key challenge with very-large-scale integration, especially if the persistent scaling of silicon electronic devices is sustained. One approach, which relies upon the directed self-assembly of block copolymers by chemical-epitaxy, is capable of achieving high density 1?:?1 patterning with critical dimensions approaching 5 nm. Herein, we outline an integration-favourable strategy for fabricating high areal density arrays of aligned silicon nanowires by directed self-assembly of a PS-b-PMMA block copolymer nanopatterns with a L(0) (pitch) of 42 nm, on chemically pre-patterned surfaces. Parallel arrays (5 10(6) wires per cm) of uni-directional and isolated silicon nanowires on insulator substrates with critical dimension ranging from 15 to 19 nm were fabricated by using precision plasma etch processes; with each stage monitored by electron microscopy. This step-by-step approach provides detailed information on interfacial oxide formation at the device silicon layer, the polystyrene profile during plasma etching, final critical dimension uniformity and line edge roughness variation nanowire during processing. The resulting silicon-nanowire array devices exhibit Schottky-type behaviour and a clear field-effect. The measured values for resistivity and specific contact resistance were ((2.6 1.2) 10(5)?cm) and ((240 80) ?cm(2)) respectively. These values are typical for intrinsic (un-doped) silicon when contacted by high work function metal albeit counterintuitive as the resistivity of the starting wafer (?10 ?cm) is 4 orders of magnitude lower. In essence, the nanowires are so small and consist of so few atoms, that statistically, at the original doping level each nanowire contains less than a single dopant atom and consequently exhibits the electrical behaviour of the un-doped host material. Moreover this indicates that the processing successfully avoided unintentional doping. Therefore our approach permits tuning of the device steps to contact the nanowires functionality through careful selection of the initial bulk starting material and/or by means of post processing steps e.g. thermal annealing of metal contacts to produce high performance devices. We envision that such a controllable process, combined with the precision patterning of the aligned block copolymer nanopatterns, could prolong the scaling of nanoelectronics and potentially enable the fabrication of dense, parallel arrays of multi-gate field effect transistors. PMID:22481430

Farrell, Richard A; Kinahan, Niall T; Hansel, Stefan; Stuen, Karl O; Petkov, Nikolay; Shaw, Matthew T; West, Laetitia E; Djara, Vladimir; Dunne, Robert J; Varona, Olga G; Gleeson, Peter G; Jung, Soon-Jung; Kim, Hye-Young; Kole?nik, Maria M; Lutz, Tarek; Murray, Christopher P; Holmes, Justin D; Nealey, Paul F; Duesberg, Georg S; Krsti?, Vojislav; Morris, Michael A

2012-05-21

128

A parallel direct numerical simulation of dust particles in a turbulent flow  

NASA Astrophysics Data System (ADS)

Due to their effects on radiation transport, aerosols play an important role in the global climate. Mineral dust aerosol is a predominant natural aerosol in the desert and semi-desert regions of the Middle East and North Africa (MENA). The Arabian Peninsula is one of the three predominant source regions on the planet "exporting" dust to almost the entire world. Mineral dust aerosols make up about 50% of the tropospheric aerosol mass and therefore produces a significant impact on the Earth's climate and the atmospheric environment, especially in the MENA region that is characterized by frequent dust storms and large aerosol generation. Understanding the mechanisms of dust emission, transport and deposition is therefore essential for correctly representing dust in numerical climate prediction. In this study we present results of numerical simulations of dust particles in a turbulent flow to study the interaction between dust and the atmosphere. Homogenous and passive dust particles in the boundary layers are entrained and advected under the influence of a turbulent flow. Currently no interactions between particles are included. Turbulence is resolved through direct numerical simulation using a parallel incompressible Navier-Stokes flow solver. Model output provides information on particle trajectories, turbulent transport of dust and effects of gravity on dust motion, which will be used to compare with the wind tunnel experiments at University of Texas at Austin. Results of testing of parallel efficiency and scalability is provided. Future versions of the model will include air-particle momentum exchanges, varying particle sizes and saltation effect. The results will be used for interpreting wind tunnel and field experiments and for improvement of dust generation parameterizations in meteorological models.

Nguyen, H. V.; Yokota, R.; Stenchikov, G.; Kocurek, G.

2012-04-01

129

Computational search for direct band gap silicon crystals  

NASA Astrophysics Data System (ADS)

Due to its abundance, silicon is the preferred solar-cell material despite the fact that current silicon materials have indirect band gaps. Although the band gap properties of silicon have been studied intensively, until now, no direct band gap silicon-based material has been found or suggested. We report here the discovery of direct band gap silicon crystals. By using conformational space annealing, we optimize various crystal structures containing multiple (10 to 20) silicon atoms per unit cell so that their electronic structures become direct band gap. Through first-principles calculations, we identify many direct and quasidirect band gap crystal structures, which exhibit excellent photovoltaic efficiency.

Lee, In-Ho; Lee, Jooyoung; Oh, Young Jun; Kim, Sunghyun; Chang, K. J.

2014-09-01

130

Direct numerical simulation of instabilities in parallel flow with spherical roughness elements  

NASA Technical Reports Server (NTRS)

Results from a direct numerical simulation of laminar flow over a flat surface with spherical roughness elements using a spectral-element method are given. The numerical simulation approximates roughness as a cellular pattern of identical spheres protruding from a smooth wall. Periodic boundary conditions on the domain's horizontal faces simulate an infinite array of roughness elements extending in the streamwise and spanwise directions, which implies the parallel-flow assumption, and results in a closed domain. A body force, designed to yield the horizontal Blasius velocity in the absence of roughness, sustains the flow. Instabilities above a critical Reynolds number reveal negligible oscillations in the recirculation regions behind each sphere and in the free stream, high-amplitude oscillations in the layer directly above the spheres, and a mean profile with an inflection point near the sphere's crest. The inflection point yields an unstable layer above the roughness (where U''(y) is less than 0) and a stable region within the roughness (where U''(y) is greater than 0). Evidently, the instability begins when the low-momentum or wake region behind an element, being the region most affected by disturbances (purely numerical in this case), goes unstable and moves. In compressible flow with periodic boundaries, this motion sends disturbances to all regions of the domain. In the unstable layer just above the inflection point, the disturbances grow while being carried downstream with a propagation speed equal to the local mean velocity; they do not grow amid the low energy region near the roughness patch. The most amplified disturbance eventually arrives at the next roughness element downstream, perturbing its wake and inducing a global response at a frequency governed by the streamwise spacing between spheres and the mean velocity of the most amplified layer.

Deanna, R. G.

1992-01-01

131

The Interplay Between Collider Searches For Supersymmetric Higgs Bosons and Direct Dark Matter Experiments  

SciTech Connect

In this article, we explore the interplay between searches for supersymmetric particles and Higgs bosons at hadron colliders (the Tevatron and the LHC) and direct dark matter searches (such as CDMS, ZEPLIN, XENON, EDELWEISS, CRESST, WARP and others). We focus on collider searches for heavy MSSM Higgs bosons (A, H, H{sup {+-}}) and how the prospects for these searches are impacted by direct dark matter limits and vice versa. We find that the prospects of these two experimental programs are highly interrelated. A positive detection of A, H or H{sup {+-}} at the Tevatron would dramatically enhance the prospects for a near future direct discovery of neutralino dark matter. Similarly, a positive direct detection of neutralino dark matter would enhance the prospects of discovering heavy MSSM Higgs bosons at the Tevatron or the LHC. Combining the information obtained from both types of experimental searches will enable us to learn more about the nature of supersymmetry.

Carena, Marcela; Hooper, Dan; /Fermilab; Vallinotto, Alberto; /Fermilab /Chicago U. /Paris, Inst. Astrophys.

2006-11-01

132

Serial Attention Mechanisms in Visual Search: A Direct Behavioral Demonstration  

Microsoft Academic Search

In visual search, inefficient performance of human observers is typically characterized by a steady increase in reaction time with the number of array elementsthe so-called set-size effect. In general, set-size effects are taken to indicate that processing of the array elements depends on limited-capacity resources, that is, it involves attention. Contrasting theories have been proposed to account for this attentional

Emanuela Bricolo; Tiziana Gianesini; Alessandra Fanini; Claus Bundesen; Leonardo Chelazzi

2002-01-01

133

Neutrinoless double beta decay and direct searches for neutrino mass  

E-print Network

Study of the neutrinoless double beta decay and searches for the manifestation of the neutrino mass in ordinary beta decay are the main sources of information about the absolute neutrino mass scale, and the only practical source of information about the charge conjugation properties of the neutrinos. Thus, these studies have a unique role in the plans for better understanding of the whole fast expanding field of neutrino physics.

Craig Aalseth; Henning Back; Loretta Dauwe; David Dean; Guido Drexlin; Yuri Efremenko; Hiro Ejiri; Steven Elliott; Jon Engel; Brian Fujikawa; Reyco Henning; G. W. Hoffmann; Karol Lang; Kevin Lesko; Tadafumi Kishimoto; Harry Miley; Rick Norman; Silvia Pascoli; Serguey Petcov; Andreas Piepke; Werner Rodejohann; David Saltzberg; Sean Sutton; Petr Vogel; Ray Warner; John Wilkerson; Lincoln Wolfenstein

2004-12-21

134

Parallel computation of GA search for the artery shape determinants with CFD  

NASA Astrophysics Data System (ADS)

We studied which factors play important role to determine the shape of arteries at the carotid artery bifurcation by performing multi-objective optimization with computation fluid dynamics (CFD) and the genetic algorithm (GA). To perform it, the most difficult problem is how to reduce turn-around time of the GA optimization with 3D unsteady computation of blood flow. We devised two levels of parallel computation method with the following features: level 1: parallel CFD computation with appropriate number of cores; level 2: parallel jobs generated by "master", which finds quickly available job cue and dispatches jobs, to reduce turn-around time. As a result, the turn-around time of one GA trial, which would have taken 462 days with one core, was reduced to less than two days on RIKEN supercomputer system, RICC, with 8192 cores. We performed a multi-objective optimization to minimize the maximum mean WSS and to minimize the sum of circumference for four different shapes and obtained a set of trade-off solutions for each shape. In addition, we found that the carotid bulb has the feature of the minimum local mean WSS and minimum local radius. We confirmed that our method is effective for examining determinants of artery shapes.

Himeno, M.; Noda, S.; Fukasaku, K.; Himeno, R.

2010-06-01

135

Parallel Game Tree Search on SIMD Machines Holger Hopp and Peter Sanders  

E-print Network

, 76128 Karlsruhe, Germany Tel: (49) 721 6084336 Fax: (49) 721 698675 E­mail: fhhopp,sandersg@ira an active area of reasearch in artificial intelligence because they constitute a nontrivial but easy to specify problem area. Since the game tree search algorithms used for most game implementations are very

Schmitt, Peter H.

136

Increasing quality of computer-generated kinoforms using direct search with random trajectory method  

NASA Astrophysics Data System (ADS)

Method of increase of quality of computer generated kinoforms is proposed. It is simple direct search method similar to direct binary search method for binary holograms generation. Main difference is that proposed direct search with random trajectory method designed to process arrays with multiple phase levels. First, kinoform is generated with conventional method such as Gerchberg-Saxton. Then, elements of kinoform are sequentially switched to obtain lower normalized standard deviation (NSTD) of reconstructed image from desired image. This process goes on until minimum NSTD drop level is reached. Proposed method provides average NSTD decrease 26%.

Bondareva, Alyona P.; Cheremkhin, Pavel A.; Evtikhiev, Nikolay N.; Krasnov, Vitaly V.; Rodin, Vladislav G.; Starikov, Sergey N.

2014-09-01

137

Current Results and Future Directions of the Pulsar Search Collaboratory  

NASA Astrophysics Data System (ADS)

The Pulsar Search Collaboratory (PSC) is a joint partnership between the National Radio Astronomy Observatory (NRAO) and West Virginia University (WVU). The ultimate goal of the PSC is to interest students in science, technology, engineering, mathematics (STEM) fields by engaging them in conducting authentic scientific research-specifically the search for new pulsars. Of the 33 schools in the original PSC program, 13 come from rural school districts; one third of these are from schools where over 50% participate in the Free/Reduced School Lunch program. We are reaching first generation college-goers. For students, the program succeeds in building confidence in students, rapport with the scientists involved in the project, and greater comfort with team-work. We see additional gains in girls, as they see themselves more as scientists after participating in the PSC program, which is an important predictor of success in STEM fields. The PSC has had several scientific successes as well. To date, PSC students have made two astronomical discoveries: a 4.8-s pulsar and bright radio burst of astrophysical origin, most likely from a sporadic neutron star. We will report on the status of the project including new evaluation data. We will also describe PSC-West, an experiment to involve schools in Illinois and Wisconsin using primarily online tools for professional development of teachers and coaching of students. Knowledge gained through our efforts with PSC-West will assist the PSC team in scaling up the project.

Heatherly, Sue Ann; Rosen, R.; McLaughlin, M.; Lorimer, D.

2011-01-01

138

Associative memory architecture for word-parallel smallest Euclidean distance search using distance mapping into clock-number domain  

NASA Astrophysics Data System (ADS)

A scalable word-parallel associative memory for smallest Euclidean distance (ED) search is presented. Due to the applied concept of distance to clock-number mapping, the reported architecture is digital in nature and scalable to advanced technology. Furthermore, the reference data of feature vectors can be scaled in principle to any vector dimension and number. Handling of the numerical complexity of the ED without large consumption of Silicon area is achieved by an area-efficient circuit, which uses the same adder for absolute-difference calculation of vector components and subsequent square calculation by sequential addition of partial products. Additionally, a clock-number minimization algorithm is proposed to significantly reduce the clock-number needed for the search when the smallest ED is a large value. The concept of the proposed architecture has been experimentally verified by measurement results from real chips fabricated in a 180 nm CMOS technology, in which the architecture is configured for parallel smallest ED search among 32 reference vectors with each vector having 16 8-bit elements. For the application example of codebook-based data compression, the fabricated test chip achieved 1.19 s average search time, 5.77 s worst-case search time and low power consumption of 8.75 mW at the maximum clock frequency of 47 MHz and nominal power supply voltage Vdd = 1.8 V. At reduced power supply voltage Vdd = 1.2 V, a smaller power consumption of 2.80 mW at an also smaller maximum clock frequency of 24 MHz is measured. In comparison to previous analog-digital architecture, a reduction of the normalized power-delay product per matching operation by about a factor 1.6 at Vdd = 1.8 V (about factor 2.5 at Vdd = 1.2 V) is obtained with best-case data for the analog-digital architecture and average-case data for the proposed fully-digital architecture.

Akazawa, Toshinobu; Sasaki, Seiryu; Jrgen Mattausch, Hans

2014-01-01

139

Interplay and Characterization of Dark Matter Searches at Colliders and in Direct Detection Experiments  

E-print Network

In this White Paper we present and discuss a concrete proposal for the consistent interpretation of Dark Matter searches at colliders and in direct detection experiments. Based on a specific implementation of simplified models of vector and axial-vector mediator exchanges, this proposal demonstrates how the two search strategies can be compared on an equal footing.

Sarah A. Malik; Christopher McCabe; Henrique Araujo; Alexander Belyaev; Celine Boehm; Jim Brooke; Oliver Buchmueller; Gavin Davies; Albert De Roeck; Kees de Vries; Matthew J. Dolan; John Ellis; Malcolm Fairbairn; Henning Flaecher; Loukas Gouskos; Valentin V. Khoze; Greg Landsberg; Dave Newbold; Michele Papucci; Timothy Sumner; Marc Thomas; Steven Worm

2014-09-14

140

Massively parallel computing and the search for jets and black holes at the LHC  

NASA Astrophysics Data System (ADS)

Massively parallel computing at the LHC could be the next leap necessary to reach an era of new discoveries at the LHC after the Higgs discovery. Scientific computing is a critical component of the LHC experiment, including operation, trigger, LHC computing GRID, simulation, and analysis. One way to improve the physics reach of the LHC is to take advantage of the flexibility of the trigger system by integrating coprocessors based on Graphics Processing Units (GPUs) or the Many Integrated Core (MIC) architecture into its server farm. This cutting edge technology provides not only the means to accelerate existing algorithms, but also the opportunity to develop new algorithms that select events in the trigger that previously would have evaded detection. In this paper we describe new algorithms that would allow us to select in the trigger new topological signatures that include non-prompt jet and black hole-like objects in the silicon tracker.

Halyo, V.; LeGresley, P.; Lujan, P.

2014-04-01

141

A Solver for Massively Parallel Direct Numerical Simulation of Three-Dimensional Multiphase Flows  

E-print Network

We present a new solver for massively parallel simulations of fully three-dimensional multiphase flows. The solver runs on a variety of computer architectures from laptops to supercomputers and on 65536 threads or more (limited only by the availability to us of more threads). The code is wholly written by the authors in Fortran 2003 and uses a domain decomposition strategy for parallelization with MPI. The fluid interface solver is based on a parallel implementation of the LCRM hybrid Front Tracking/Level Set method designed to handle highly deforming interfaces with complex topology changes. We discuss the implementation of this interface method and its particular suitability to distributed processing where all operations are carried out locally on distributed subdomains. We have developed parallel GMRES and Multigrid iterative solvers suited to the linear systems arising from the implicit solution of the fluid velocities and pressure in the presence of strong density and viscosity discontinuities across flu...

Shin, S; Juric, D

2014-01-01

142

WIMP Dark Matter Direct-Detection Searches in Noble Gases  

E-print Network

Cosmological observations and the dynamics of the Milky Way provide ample evidence for an invisible and dominant mass component. This so-called dark matter could be made of new, colour and charge neutral particles, which were non-relativistic when they decoupled from ordinary matter in the early universe. Such weakly interacting massive particles (WIMPs) are predicted to have a non-zero coupling to baryons and could be detected via their collisions with atomic nuclei in ultra-low background, deep underground detectors. Among these, detectors based on liquefied noble gases have demonstrated tremendous discovery potential over the last decade. After briefly introducing the phenomenology of direct dark matter detection, I will review the main properties of liquefied argon and xenon as WIMP targets and discuss sources of background. I will then describe existing and planned argon and xenon detectors that employ the so-called single- and dual-phase detection techniques, addressing their complementarity and science...

Baudis, Laura

2014-01-01

143

WIMP Dark Matter Direct-Detection Searches in Noble Gases  

E-print Network

Cosmological observations and the dynamics of the Milky Way provide ample evidence for an invisible and dominant mass component. This so-called dark matter could be made of new, colour and charge neutral particles, which were non-relativistic when they decoupled from ordinary matter in the early universe. Such weakly interacting massive particles (WIMPs) are predicted to have a non-zero coupling to baryons and could be detected via their collisions with atomic nuclei in ultra-low background, deep underground detectors. Among these, detectors based on liquefied noble gases have demonstrated tremendous discovery potential over the last decade. After briefly introducing the phenomenology of direct dark matter detection, I will review the main properties of liquefied argon and xenon as WIMP targets and discuss sources of background. I will then describe existing and planned argon and xenon detectors that employ the so-called single- and dual-phase detection techniques, addressing their complementarity and science reach.

Laura Baudis

2014-08-19

144

Experience with Approximations in the Trust-Region Parallel Direct Search Algorithm  

E-print Network

of the authors were members of the Computational Sciences and Mathematics Research group at Sandia National Lab and Development Department Sandia National Laboratories Livermore, CA 94551 pdhough@sandia.gov Abstract. Recent- oratories. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company

Shontz, Suzanne M.

145

Experience with Approximations in the Trust-Region Parallel Direct Search Algorithm  

E-print Network

of the Computational Sciences and Mathematics Research group at Sandia National Lab- oratories. Sandia and Development Department Sandia National Laboratories Livermore, CA 94551 pdhough@sandia.gov Abstract. Recent is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States

Howle, Victoria E.

146

Spiral search: a hydrophobic-core directed local search for simplified PSP on 3D FCC lattice  

PubMed Central

Background Protein structure prediction is an important but unsolved problem in biological science. Predicted structures vary much with energy functions and structure-mapping spaces. In our simplified ab initio protein structure prediction methods, we use hydrophobic-polar (HP) energy model for structure evaluation, and 3-dimensional face-centred-cubic lattice for structure mapping. For HP energy model, developing a compact hydrophobic-core (H-core) is essential for the progress of the search. The H-core helps find a stable structure with the lowest possible free energy. Results In order to build H-cores, we present a new Spiral Search algorithm based on tabu-guided local search. Our algorithm uses a novel H-core directed guidance heuristic that squeezes the structure around a dynamic hydrophobic-core centre. We applied random walks to break premature H-cores and thus to avoid early convergence. We also used a novel relay-restart technique to handle stagnation. Conclusions We have tested our algorithms on a set of benchmark protein sequences. The experimental results show that our spiral search algorithm outperforms the state-of-the-art local search algorithms for simplified protein structure prediction. We also experimentally show the effectiveness of the relay-restart. PMID:23368706

2013-01-01

147

Earthquake Location, Direct, Global-Search Methods E 2449 Earthquake Location,  

E-print Network

Earthquake Location, Direct, Global-Search Methods E 2449 Earthquake Location, Direct, Global Kingdom Article Outline Glossary Definition of the Subject Introduction The Earthquake Location Problem or temporal av- erage of some characteristic of an earthquake, such as surface shaking intensity or moment

148

Link search algorithms for a spread-spectrum mobile communication network with directive\\/adaptive antennas  

Microsoft Academic Search

A non-centralized fully distributed mobile communication network with directive or adaptive antennas is proposed. Every node uses directive or adaptive antennas for transmitting and receiving communication signals. The spatial and temporal synchronization of the transmitting and receiving antenna beams is accomplished by employing the Global Positioning System (GPS) information and a double-ended spatial search algorithm. This research focuses on the

Tien-Yow Liu; Robert A. Scholtz

1998-01-01

149

Parallel algorithm for solving Keplers equation on Graphics Processing Units: Application to analysis of Doppler exoplanet searches  

NASA Astrophysics Data System (ADS)

We present the results of a highly parallel Kepler equation solver using the Graphics Processing Unit (GPU) on a commercial nVidia GeForce 280GTX and the "Compute Unified Device Architecture" (CUDA) programming environment. We apply this to evaluate a goodness-of-fit statistic (e.g., ?2) for Doppler observations of stars potentially harboring multiple planetary companions (assuming negligible planet-planet interactions). Given the high-dimensionality of the model parameter space (at least five dimensions per planet), a global search is extremely computationally demanding. We expect that the underlying Kepler solver and model evaluator will be combined with a wide variety of more sophisticated algorithms to provide efficient global search, parameter estimation, model comparison, and adaptive experimental design for radial velocity and/or astrometric planet searches. We tested multiple implementations using single precision, double precision, pairs of single precision, and mixed precision arithmetic. We find that the vast majority of computations can be performed using single precision arithmetic, with selective use of compensated summation for increased precision. However, standard single precision is not adequate for calculating the mean anomaly from the time of observation and orbital period when evaluating the goodness-of-fit for real planetary systems and observational data sets. Using all double precision, our GPU code outperforms a similar code using a modern CPU by a factor of over 60. Using mixed precision, our GPU code provides a speed-up factor of over 600, when evaluating n>1024 models planetary systems each containing n=4 planets and assuming n=256 observations of each system. We conclude that modern GPUs also offer a powerful tool for repeatedly evaluating Kepler's equation and a goodness-of-fit statistic for orbital models when presented with a large parameter space.

Ford, Eric B.

2009-05-01

150

Direct observation of stronger flux-line pinning of crossed compared to parallel linear defects  

SciTech Connect

Linear defects were introduced in high-temperature superconductors (HTSC{close_quote}s) by high-energy heavy-ion irradiation. Flux penetration into partly crossed and parallel irradiated HTSC{close_quote}s was observed by magneto- optics. The obtained flux distributions show that the critical current density {ital j}{sub {ital c}} in cross-irradiated HTSC{close_quote}s is larger by a factor up to 14 than in parallel irradiated HTSC{close_quote}s. {copyright} {ital 1996 The American Physical Society.}

Schuster, T.; Kuhn, H. [Max-Planck-Institut fuer Metallforschung, Institut fuer Physik, Postfach 800665, D-70506 Stuttgart (Germany)] [Max-Planck-Institut fuer Metallforschung, Institut fuer Physik, Postfach 800665, D-70506 Stuttgart (Germany); Indenbom, M.V. [Institut de Genie Atomique, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland)] [Institut de Genie Atomique, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland); Kreiselmeyer, G.; Leghissa, M. [III. Physikalisches Institut, Universitaet Erlangen-Nuernberg, Erwin-Rommel-Strasse 1, D-91058 Erlangen (Germany)] [III. Physikalisches Institut, Universitaet Erlangen-Nuernberg, Erwin-Rommel-Strasse 1, D-91058 Erlangen (Germany); Klaumuenzer, S. [Hahn-Meitner-Institut, Postfach 390128, D-14091 Berlin (Germany)] [Hahn-Meitner-Institut, Postfach 390128, D-14091 Berlin (Germany)

1996-02-01

151

Parallel Global Aircraft Configuration Design Space Exploration  

E-print Network

Parallel Global Aircraft Configuration Design Space Exploration CHUCK A. BAKER, LAYNE T. WATSON of a parallel computer. Section 2 describes the aircraft design problem, Section 3 gives the direct search, BERNARD GROSSMAN, WILLIAM H. MASON Multidisciplinary Analysis and Design (MAD) Center for Advanced

Neumaier, Arnold

152

Directed intermittent search for a hidden target on a dendritic tree  

NASA Astrophysics Data System (ADS)

Motivated by experimental observations of active (motor-driven) intracellular transport in neuronal dendrites, we analyze a stochastic model of directed intermittent search on a tree network. A particle injected from the cell body or soma into the primary branch of the dendritic tree randomly switches between a stationary search phase and a mobile nonsearch phase that is biased in the forward direction. A (synaptic) target is presented somewhere within the tree, which the particle can locate if it is within a certain range and in the searching phase. We approximate the moment generating function using Greens function methods. The moment generating function is then used to compute the hitting probability and conditional mean first passage time to the target. We show that in contrast to a previously explored finite interval case, there is a range of parameters for which a bidirectional search strategy is more efficient than a unidirectional one in finding the target.

Newby, Jay M.; Bressloff, Paul C.

2009-08-01

153

PeliGRIFF, a parallel DEM-DLM\\/FD direct numerical simulation tool for 3D particulate flows  

Microsoft Academic Search

The problem of particulate flows at moderate to high concentration and finite Reynolds number is addressed by parallel direct\\u000a numerical simulation. The present contribution is an extension of the work published in Computers & Fluids 38:1608 (2009), where systems of moderate size in a 2D geometry were examined. At the numerical level, the suggested method is inspired\\u000a by the framework

Anthony Wachs

154

Parallel spatial direct numerical simulation of boundary-layer flow transition on IBM SP1  

SciTech Connect

The spatially evolving disturbances that are associated with laminar-to-turbulent transition in three-dimensional boundary-layer flows are computed with the PSDNS code on an IBM SP1 parallel supercomputer. By remapping the distributed data structure during the course of the calculation, optimized serial library routines can be utilized that substantially increase the computational performance. Although the remapping incurs a high communication penalty, the parallel efficiency of the code remains above 40 percent for all performed calculations. By using appropriate compile options and optimized library routines, the serial code achieves 52-56 Mflops on a single node of the SP1 (45 percent of theoretical peak performance). The actual performance of the PSDNS code on the SP1 is evaluated with a ``real world`` simulation that consists of 1.7 million grid points. Comparisons to the Cray Y/MP and Cray C-90 are made for this large scale simulation.

Hanebutte, U.R. [Argonne National Lab., IL (United States); Joslin, R.D. [National Aeronautics and Space Administration, Hampton, VA (United States). Langley Research Center; Zubair, M. [International Business Machines Corp., Yorktown Heights, NY (United States). Thomas J. Watson Research Center

1995-07-01

155

Precision measurements, dark matter direct detection and LHC Higgs searches in a constrained NMSSM  

SciTech Connect

We reexamine the constrained version of the Next-to-Minimal Supersymmetric Standard Model with semi universal parameters at the GUT scale (CNMSSM). We include constraints from collider searches for Higgs and susy particles, upper bound on the relic density of dark matter, measurements of the muon anomalous magnetic moment and of B-physics observables as well as direct searches for dark matter. We then study the prospects for direct detection of dark matter in large scale detectors and comment on the prospects for discovery of heavy Higgs states at the LHC.

Belanger, G. [LAPTH, U. de Savoie, CNRS, 9 Chemin de Bellevue, 74940 Annecy-le-Vieux (France)] [LAPTH, U. de Savoie, CNRS, 9 Chemin de Bellevue, 74940 Annecy-le-Vieux (France); Hugonie, C. [Laboratoire Physique Theorique et Astroparticules, Universite de Montpellier II, Place Eugene Bataillon, 34095 Montpellier (France)] [Laboratoire Physique Theorique et Astroparticules, Universite de Montpellier II, Place Eugene Bataillon, 34095 Montpellier (France); Pukhov, A., E-mail: belanger@lapp.in2p3.fr, E-mail: cyril.hugonie@lpta.univ-montp2.fr, E-mail: pukhov@lapp.in2p3.fr [Skobeltsyn Institute of Nuclear Physics, Moscow State University, Leninskie gory, GSP-1, Moscow 119991 (Russian Federation)

2009-01-15

156

Do cataclastic deformation bands form parallel to lines of no finite elongation (LNFE) or zero extension directions?  

NASA Astrophysics Data System (ADS)

Conjugate cataclastic deformation bands cut unconsolidated sand and gravel at McKinleyville, California, and dip shallowly towards the north-northeast and south-southwest. The acute dihedral angle between the two sets of deformation bands is 47 and is bisected by the sub-horizontal, north-northeast directed incremental and finite shortening directions. Trishear models of fault propagation folding above the McKinleyville fault predict two sets of LNFE (lines of no finite elongation) that plunge steeply and shallowly to the south and north. These predictions are inconsistent with deformation band orientations and suggest that deformation bands did not form parallel to these LNFE. During plane strain, zero extension directions with acute dihedral angles of 47 develop when the dilatancy rate (dV/d?1) is-4.3. Experimental dilatancy rates for Vosges sandstone (cohesion>0) and unconsolidated Hostun sand suggest the deformation bands either developed parallel to zero extension directions or in accordance with the Mohr-Coulomb criterion, assuming initial porosities of 22% and 39%, respectively. An empirical relationship between dV/d?1, relative density and mean stress suggests that dilatancy rates for Vosges sandstone overestimate dV/d?1 at McKinleyville. Deformation bands at McKinleyville likely developed either in a Mohr-Coulomb orientation, or an intermediate orientation bounded by the Mohr-Coulomb (?C) and Roscoe (?R) angles.

Imber, Jonathan; Perry, Tom; Jones, Richard R.; Wightman, Ruth H.

2012-12-01

157

Moving dim point target detection with three-dimensional wide-to-exact search directional filtering  

Microsoft Academic Search

We assess the performance of a novel three-dimensional wide-to-exact search directional filtering (3DWESDF) algorithm for detecting and tracking a weak moving dim target against a cluttered background in real infrared (IR) image sequence. This paper proposed a novel 3DWESDF to decrease the 3D directional filters (3DDF) computational requirements and increase the target energy accumulation ability further. Prior to the filtering,

Tianxu Zhang; Meng Li; Zhengrong Zuo; Weidong Yang; Xiechang Sun

2007-01-01

158

Halftoning via direct binary search using analytical and stochastic printer models  

Microsoft Academic Search

We incorporate models for printer dot interactions within the iterative direct binary search (DBS) halftoning algorithm. Monochrome electro-photographic printers are considered. Both analytical and stochastic models are studied. In the analytical model it is assumed that the printer can generate a circular spot with constant absorptance at each printer addressable location, whereas the stochastic model is based on microscopic absorptance

Farhan A. Baqai; Jan P. Allebach

2003-01-01

159

Effects of the self-directed search on high school students  

Microsoft Academic Search

Compared the effects on 959 high school students of the Self-Directed Search (SDS), a self-administered vocational counseling simulation; the Vocational Preference Inventory (VPI); and no treatment. Students taking the SDS or the VPI evaluated the instruments as moderately positive, reported feeling more satisfied with their current occupational choice, and were considering more occupational alternatives than the control group both the

Thelma B. Zener; Leslie Schnuelle

1976-01-01

160

Twin Similarities in Holland Types as Shown by Scores on the Self-Directed Search  

ERIC Educational Resources Information Center

This study examined the degree of similarity between scores on the Self-Directed Search from one set of identical twins. Predictably, a high congruence score was found. Results from a biographical sheet are discussed as well as implications of the results for career counselors.

Chauvin, Ida; McDaniel, Janelle R.; Miller, Mark J.; King, James M.; Eddlemon, Ondie L. M.

2012-01-01

161

Bolometric calibration of a superfluid 3 detector for Dark Matter search: direct  

E-print Network

Bolometric calibration of a superfluid 3 He detector for Dark Matter search: direct measurement of the ultra-violet scintillation rate of irradiated helium, demonstrating the possibility of efficient electron recoil event rejection. Key words: Dark Matter, Superfluid Helium-3, Bolometer, Scintillation

Paris-Sud XI, Université de

162

Congruency between Occupational Daydreams and Self Directed Search (SDS) Scores among College Students  

ERIC Educational Resources Information Center

In this study, the relationship of expressed occupational daydreams and scores on the Self-Directed Search (SDS) were examined. Results were consistent with Holland's theory of careers. Implications for career counselors are discussed. Students were asked to provide specific biographical data (i. e., age, gender, race) and to write down their

Miller, Mark J.; Springer, Thomas P.; Tobacyk, Jerome; Wells, Don

2004-01-01

163

Interpreting Self-Directed Search Profiles: Validity of the "Rule of Eight"  

ERIC Educational Resources Information Center

Based on the standard error of measurement, Holland (1985) suggested the "rule of eight" for determining the meaningfulness of differences between two summary scores on the Self Directed Search. The present study empirically examined the rule's validity for practice. The participants were 2397 (1497 females and 900 males) undergraduate students

Glavin, Kevin W.; Savickas, Mark L.

2011-01-01

164

Wavefront Synthesis and Reconstruction: Direct Binary Search Holograms and Synthetic Aperture Radar  

Microsoft Academic Search

Computer-generated binary holograms can perform complex waveshaping functions that are beyond the capability of ordinary refractive optical elements. An iterative procedure for the synthesis of computer-generated holograms (CGH's) is investigated that consists of a direct binary search (DBS) for the element configuration that minimizes the error between the actual and desired reconstructed wavefronts. Although DBS CGH's have low reconstruction error

Brian Keith Jennison

1990-01-01

165

Visual Search for Human Gaze Direction by a Chimpanzee (Pan troglodytes)  

PubMed Central

Background Humans detect faces with direct gazes among those with averted gazes more efficiently than they detect faces with averted gazes among those with direct gazes. We examined whether this stare-in-the-crowd effect occurs in chimpanzees (Pan troglodytes), whose eye morphology differs from that of humans (i.e., low-contrast eyes, dark sclera). Methodology/Principal Findings An adult female chimpanzee was trained to search for an odd-item target (front view of a human face) among distractors that differed from the target only with respect to the direction of the eye gaze. During visual-search testing, she performed more efficiently when the target was a direct-gaze face than when it was an averted-gaze face. This direct-gaze superiority was maintained when the faces were inverted and when parts of the face were scrambled. Subsequent tests revealed that gaze perception in the chimpanzee was controlled by the contrast between iris and sclera, as in humans, but that the chimpanzee attended only to the position of the iris in the eye, irrespective of head direction. Conclusion/Significance These results suggest that the chimpanzee can discriminate among human gaze directions and are more sensitive to direct gazes. However, limitations in the perception of human gaze by the chimpanzee are suggested by her inability to completely transfer her performance to faces showing a three-quarter view. PMID:20161750

Tomonaga, Masaki; Imura, Tomoko

2010-01-01

166

Chaining direct memory access data transfer operations for compute nodes in a parallel computer  

DOEpatents

Methods, systems, and products are disclosed for chaining DMA data transfer operations for compute nodes in a parallel computer that include: receiving, by an origin DMA engine on an origin node in an origin injection FIFO buffer for the origin DMA engine, a RGET data descriptor specifying a DMA transfer operation data descriptor on the origin node and a second RGET data descriptor on the origin node, the second RGET data descriptor specifying a target RGET data descriptor on the target node, the target RGET data descriptor specifying an additional DMA transfer operation data descriptor on the origin node; creating, by the origin DMA engine, an RGET packet in dependence upon the RGET data descriptor, the RGET packet containing the DMA transfer operation data descriptor and the second RGET data descriptor; and transferring, by the origin DMA engine to a target DMA engine on the target node, the RGET packet.

Archer, Charles J. (Rochester, MN); Blocksome, Michael A. (Rochester, MN)

2010-09-28

167

Multiparty controlled quantum secure direct communication based on quantum search algorithm  

NASA Astrophysics Data System (ADS)

In this study, a new controlled quantum secure direct communication (CQSDC) protocol using the quantum search algorithm as the encoding function is proposed. The proposed protocol is based on the multi-particle Greenberger-Horne-Zeilinger entangled state and the one-step quantum transmission strategy. Due to the one-step transmission of qubits, the proposed protocol can be easily extended to a multi-controller environment, and is also free from the Trojan horse attacks. The analysis shows that the use of quantum search algorithm in the construction of CQSDC appears very promising.

Kao, Shih-Hung; Hwang, Tzonelih

2013-12-01

168

Solar power satellite rectenna design study: Directional receiving elements and parallel-series combining analysis  

NASA Technical Reports Server (NTRS)

Rectenna conversion efficiencies (RF to dc) approximating 85 percent were demonstrated on a small scale, clearly indicating the feasibility and potential of efficiency of microwave power to dc. The overall cost estimates of the solar power satellite indicate that the baseline rectenna subsystem will be between 25 to 40 percent of the system cost. The directional receiving elements and element extensions were studied, along with power combining evaluation and evaluation extensions.

Gutmann, R. J.; Borrego, J. M.

1978-01-01

169

Cognitive Architecture for Direction of Attention Founded on Subliminal Memory Searches, Pseudorandom and Nonstop  

E-print Network

By way of explaining how a brain works logically, human associative memory is modeled with logical and memory neurons, corresponding to standard digital circuits. The resulting cognitive architecture incorporates basic psychological elements such as short term and long term memory. Novel to the architecture are memory searches using cues chosen pseudorandomly from short term memory. Recalls alternated with sensory images, many tens per second, are analyzed subliminally as an ongoing process, to determine a direction of attention in short term memory.

Burger, J R

2008-01-01

170

Search Learning and the Direction of R&D Following the Pheromone Trail  

Microsoft Academic Search

Abstract Although the economic literature on R&D is very broad, the question of direction in R&D investment, which is obvious ly of great importance, has been scarcely analyzed.This paper interprets R&D as search problem,in an unknown,technological environment. Inspiration for some,of the modeling,ideas in addressing this problem is found in t he behavior of foraging ants. It is within this context

Roy Shalem

171

Generic serial and parallel on-line direct-injection using turbulent flow liquid chromatography/tandem mass spectrometry.  

PubMed

The development of turbulent flow chromatography (TFC) has enabled considerable growth in the utility of on-line direct-injection technologies. TFC has now become established in a large number of varied analytical environments, particularly drug discovery/pharmacokinetics, metabolite profiling, combinatorial library purification, pre-clinical and clinical GLP applications. The utility of turbulent flow technology for in-house pre-clinical and clinical quantitative applications has necessitated extensive valve-cleaning procedures, and consequently lengthy cycle-times, to effectively remove the system carry-over. In-house requirements for assay validation require carry-over less than 20% of the lowest level of quantification (LLOQ), corresponding to 0.02% carry-over for a linear calibration range incorporating 3 orders. A generic turbulent flow chromatography protocol has been developed for drug discovery that incorporates polymeric turbulent flow extraction (cyclone) with C18-based reverse-phase chromatography. Further, multiple wash steps are incorporated within the methodology to meet in-house requirements for carry-over. Selection of novel switching-valve materials based on polyarylethyl ketone (PAEK) and Hastelloy/Valcon E autosampler injection hardware has enabled us to significantly impact the cycle-time required to reduce carry-over. Consequently, optimal usage of switching valves has enabled parallel operation for a generic on-line direct-injection methodology to successfully reduce the total cycle-time. Overall reductions from 4 min per sample to 90 s per sample are shown with comparable data quality using a proprietary target molecule from 0.1-100 ng/mL. This paper describes the hardware configuration and methodologies utilized to perform generic serial and parallel on-line direct-injection using a Turboflow HTLC 2300 system. PMID:12207368

Grant, Russell P; Cameron, Cheryl; Mackenzie-McMurter, Shelley

2002-01-01

172

Simulations of particle acceleration in parallel shocks: Direct comparison between Monte Carlo and one-dimensional hybrid codes  

NASA Technical Reports Server (NTRS)

We have made a direct comparison between two different computer simulations of a plane, parallel, collisionless shock including particle acceleration to energies typical of those of diffuse ions observed at the earth bow shock. Despite the fact that the one-dimensional hybrid and Monte Carlo techniques employ entirely different algorithms, they give surprisingly close agreement in the overall shapes of the complete distribution functions for protons as well as heavier ions. Both methods show that energetic ions emerge smoothly from the background thermal plasma with approximately the same relative injection rate and that the fraction of the incoming plasma's energy flux that is converted into downstream enthalpy flux of the accelerated population (i.e., the acceleration efficiency) is similar in the two cases. The fraction of the downstream proton distribution made up of superthermal particles is quite large, with at least 10% of the energy flux going into protons with energies above 10 keV. In addition, an upstream precursor, produced by backstreaming energetic particles, is present in both shocks, although the Monte Carlo precursor is considerably longer than that produced in the hybrid shock. These results offer convincing evidence that, at least in these ways, the two simulations are consistent in their description of parallel shock structure and particle acceleration, and they lay the groundwork for development of shock models employing a combination of both methods.

Ellison, Donald C.; Giacalone, J.; Burgess, D.; Schwartz, S. J.

1993-01-01

173

Advancing predictive models for particulate formation in turbulent flames via massively parallel direct numerical simulations.  

PubMed

Combustion of fossil fuels is likely to continue for the near future due to the growing trends in energy consumption worldwide. The increase in efficiency and the reduction of pollutant emissions from combustion devices are pivotal to achieving meaningful levels of carbon abatement as part of the ongoing climate change efforts. Computational fluid dynamics featuring adequate combustion models will play an increasingly important role in the design of more efficient and cleaner industrial burners, internal combustion engines, and combustors for stationary power generation and aircraft propulsion. Today, turbulent combustion modelling is hindered severely by the lack of data that are accurate and sufficiently complete to assess and remedy model deficiencies effectively. In particular, the formation of pollutants is a complex, nonlinear and multi-scale process characterized by the interaction of molecular and turbulent mixing with a multitude of chemical reactions with disparate time scales. The use of direct numerical simulation (DNS) featuring a state of the art description of the underlying chemistry and physical processes has contributed greatly to combustion model development in recent years. In this paper, the analysis of the intricate evolution of soot formation in turbulent flames demonstrates how DNS databases are used to illuminate relevant physico-chemical mechanisms and to identify modelling needs. PMID:25024412

Bisetti, Fabrizio; Attili, Antonio; Pitsch, Heinz

2014-08-13

174

Applicability of preparative overpressured layer chromatography and direct bioautography in search of antibacterial chamomile compounds.  

PubMed

In situ sample preparation and preparative overpressured layer chromatography (OPLC) fractionation on a 0.5 mm thick adsorbent layer of chamomile flower methanol extract prepurified by conventional gravitation accelerated column chromatography were applied in searching for bioactive components. Sample cleanup in situ on the adsorbent layer subsequent to sample application was performed using mobile phase flow in the opposite direction (the input and output of the eluent was exchanged). The antibacterial effect of the fractions obtained from the stepwise gradient OPLC separation with the flow in the normal direction was evaluated by direct bioautography against two Gram-negative bacteria: the luminescence gene tagged plant pathogenic Pseudomonas syringae pv. maculicola, and the naturally luminescent marine bacterium Vibrio fischeri. The fractions having strong activity were analyzed by SPME-GC/MS and HPLC/MS/MS. Mainly essential oil components, coumarins, flavonoids, phenolic acids, and fatty acids were tentatively identified in the fractions. PMID:24645496

Mricz, Agnes M; Ott, Pter G; Alberti, Agnes; Bszrmnyi, Andrea; Lemberkovics, Eva; Szoke, Eva; Kry, Agnes; Mincsovics, Emil

2013-01-01

175

Towards Direct Detection of WIMPs with the Cryogenic Dark Matter Search  

SciTech Connect

The Cryogenic Dark Matter Search (CDMS) is carrying out a direct detection search for Weakly Interacting Massive Particles (WIMPs), one of the favored candidates for dark matter. Our latest data has placed some of the most stringent limits on the WIMP-nucleon spin-independent cross section of 6.6x10{sup -44} cm{sup 2} for 60 GeV WIMPs at the 90% confidence level. This paper describes our experiment and our latest results; the status of SuperCDMS Soudan, a new experiment at the Soudan mine in Minnesota that will achieve a sensitivity of 5x10{sup -45} cm{sup 2} our plans for SuperCDMS SNOLAB, a 100 kg experiment with a projected sensitivity of 3x10{sup -46} cm{sup 2}; and GEODM, a ton-scale experiment at DUSEL with a projected sensitivity of 2x10{sup -47} cm{sup 2}.

Figueroa-Feliciano, E. [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

2010-02-10

176

Distributed and Parallel Databases An Efficient Privacy-Preserving Multi-Keyword Search over Encrypted Cloud Data with  

E-print Network

Encrypted Cloud Data with Ranking --Manuscript Draft-- Manuscript Number: Full Title: An Efficient Privacy-Preserving-aware Data Mgmt Keywords: privacy-preserving keyword search; cloud storage; ranking Corresponding Author Privacy-Preserving Multi-Keyword Search over Encrypted Cloud Data with Ranking Cengiz ¨Orencik · Erkay

Yanikoglu, Berrin

177

Prospects for a direct dark matter search using high resistivity CCD detectors  

E-print Network

The possibility of using CCD detectors in a low threshold direct detection dark matter search experiment is discussed. We present the main features of the DECam detectors that make them a good alternative for such an experiment, namely their low noise and their large depleted volume. The performance of the DECam CCDs for the detection of nuclear recoils is discussed, and a measurement of the ionization efficiency for these events is presented. Finally the plans and expected reach for the CCD Experiment at Low Background (CELB) are discussed.

J. Estrada; H. Cease; H. T. Diehl; B. Flaugher; J. Jones; D. Kubik; A. Sonnenschein

2008-02-20

178

A directed search for continuous Gravitational Waves from the Galactic Center  

E-print Network

We present the results of a directed search for continuous gravitational waves from unknown, isolated neutron stars in the Galactic Center region, performed on two years of data from LIGO's fifth science run from two LIGO detectors. The search uses a semi-coherent approach, analyzing coherently 630 segments, each spanning 11.5 hours, and then incoherently combining the results of the single segments. It covers gravitational wave frequencies in a range from 78 to 496 Hz and a frequency-dependent range of first order spindown values down to -7.86 x 10^-8 Hz/s at the highest frequency. No gravitational waves were detected. We place 90% confidence upper limits on the gravitational wave amplitude of sources at the Galactic Center. Placing 90% confidence upper limits on the gravitational wave amplitude of sources at the Galactic Center, we reach ~3.35x10^-25 for frequencies near 150 Hz. These upper limits are the most constraining to date for a large-parameter-space search for continuous gravitational wave signals.

The LIGO Scientific Collaboration; The Virgo Collaboration; J. Aasi; J. Abadie; B. P. Abbott; R. Abbott; T. Abbott; M. R. Abernathy; T. Accadia; F. Acernese; C. Adams; T. Adams; R. X. Adhikari; C. Affeldt; M. Agathos; N. Aggarwal; O. D. Aguiar; P. Ajith; B. Allen; A. Allocca; E. Amador Ceron; D. Amariutei; R. A. Anderson; S. B. Anderson; W. G. Anderson; K. Arai; M. C. Araya; C. Arceneaux; J. Areeda; S. Ast; S. M. Aston; P. Astone; P. Aufmuth; C. Aulbert; L. Austin; B. E. Aylott; S. Babak; P. T. Baker; G. Ballardin; S. W. Ballmer; J. C. Barayoga; D. Barker; S. H. Barnum; F. Barone; B. Barr; L. Barsotti; M. Barsuglia; M. A. Barton; I. Bartos; R. Bassiri; A. Basti; J. Batch; J. Bauchrowitz; Th. S. Bauer; M. Bebronne; B. Behnke; M. Bejger; M. G. Beker; A. S. Bell; C. Bell; I. Belopolski; G. Bergmann; J. M. Berliner; A. Bertolini; D. Bessis; J. Betzwieser; P. T. Beyersdorf; T. Bhadbhade; I. A. Bilenko; G. Billingsley; J. Birch; M. Bitossi; M. A. Bizouard; E. Black; J. K. Blackburn; L. Blackburn; D. Blair; M. Blom; O. Bock; T. P. Bodiya; M. Boer; C. Bogan; C. Bond; F. Bondu; L. Bonelli; R. Bonnand; R. Bork; M. Born; S. Bose; L. Bosi; J. Bowers; C. Bradaschia; P. R. Brady; V. B. Braginsky; M. Branchesi; C. A. Brannen; J. E. Brau; J. Breyer; T. Briant; D. O. Bridges; A. Brillet; M. Brinkmann; V. Brisson; M. Britzger; A. F. Brooks; D. A. Brown; D. D. Brown; F. Brckner; T. Bulik; H. J. Bulten; A. Buonanno; D. Buskulic; C. Buy; R. L. Byer; L. Cadonati; G. Cagnoli; J. Caldern Bustillo; E. Calloni; J. B. Camp; P. Campsie; K. C. Cannon; B. Canuel; J. Cao; C. D. Capano; F. Carbognani; L. Carbone; S. Caride; A. Castiglia; S. Caudill; M. Cavagli; F. Cavalier; R. Cavalieri; G. Cella; C. Cepeda; E. Cesarini; R. Chakraborty; T. Chalermsongsak; S. Chao; P. Charlton; E. Chassande-Mottin; X. Chen; Y. Chen; A. Chincarini; A. Chiummo; H. S. Cho; J. Chow; N. Christensen; Q. Chu; S. S. Y. Chua; S. Chung; G. Ciani; F. Clara; D. E. Clark; J. A. Clark; F. Cleva; E. Coccia; P. -F. Cohadon; A. Colla; M. Colombini; M. Constancio Jr; A. Conte; R. Conte; D. Cook; T. R. Corbitt; M. Cordier; N. Cornish; A. Corsi; C. A. Costa; M. W. Coughlin; J. -P. Coulon; S. Countryman; P. Couvares; D. M. Coward; M. Cowart; D. C. Coyne; K. Craig; J. D. E. Creighton; T. D. Creighton; S. G. Crowder; A. Cumming; L. Cunningham; E. Cuoco; K. Dahl; T. Dal Canton; M. Damjanic; S. L. Danilishin; S. D'Antonio; K. Danzmann; V. Dattilo; B. Daudert; H. Daveloza; M. Davier; G. S. Davies; E. J. Daw; R. Day; T. Dayanga; R. De Rosa; G. Debreczeni; J. Degallaix; W. Del Pozzo; E. Deleeuw; S. Delglise; T. Denker; T. Dent; H. Dereli; V. Dergachev; R. DeRosa; R. DeSalvo; S. Dhurandhar; L. Di Fiore; A. Di Lieto; I. Di Palma; A. Di Virgilio; M. Daz; A. Dietz; K. Dmitry; F. Donovan; K. L. Dooley; S. Doravari; M. Drago; R. W. P. Drever; J. C. Driggers; Z. Du; J. -C. Dumas; S. Dwyer; T. Eberle; M. Edwards; A. Effler; P. Ehrens; J. Eichholz; S. S. Eikenberry; G. Endrczi; R. Essick; T. Etzel; K. Evans; M. Evans; T. Evans; M. Factourovich; V. Fafone; S. Fairhurst; Q. Fang; B. Farr; W. Farr; M. Favata; D. Fazi; H. Fehrmann; D. Feldbaum; I. Ferrante; F. Ferrini; F. Fidecaro; L. S. Finn; I. Fiori; R. Fisher; R. Flaminio; E. Foley; S. Foley; E. Forsi; L. A. Forte; N. Fotopoulos; J. -D. Fournier; S. Franco; S. Frasca; F. Frasconi; M. Frede; M. Frei; Z. Frei; A. Freise; R. Frey; T. T. Fricke; P. Fritschel; V. V. Frolov; M. -K. Fujimoto; P. Fulda; M. Fyffe; J. Gair; L. Gammaitoni; J. Garcia; F. Garufi; N. Gehrels; G. Gemme; E. Genin; A. Gennai; L. Gergely; S. Ghosh; J. A. Giaime; S. Giampanis; K. D. Giardina; A. Giazotto; S. Gil-Casanova; C. Gill; J. Gleason; E. Goetz; R. Goetz; L. Gondan; G. Gonzlez; N. Gordon; M. L. Gorodetsky; S. Gossan; S. Goler; R. Gouaty; C. Graef; P. B. Graff; M. Granata; A. Grant; S. Gras; C. Gray; R. J. S. Greenhalgh; A. M. Gretarsson; C. Griffo; H. Grote; K. Grover; S. Grunewald; G. M. Guidi; C. Guido; K. E. Gushwa; E. K. Gustafson; R. Gustafson; B. Hall; E. Hall; D. Hammer; G. Hammond; M. Hanke; J. Hanks; C. Hanna; J. Hanson; J. Harms; G. M. Harry; I. W. Harry; E. D. Harstad; M. T. Hartman; K. Haughian; K. Hayama; J. Heefner; A. Heidmann; M. Heintze; H. Heitmann; P. Hello; G. Hemming; M. Hendry; I. S. Heng; A. W. Heptonstall; M. Heurs; S. Hild; D. Hoak; K. A. Hodge; K. Holt; M. Holtrop; T. Hong; S. Hooper; T. Horrom; D. J. Hosken; J. Hough; E. J. Howell; Y. Hu; Z. Hua; V. Huang; E. A. Huerta; B. Hughey; S. Husa; S. H. Huttner; M. Huynh; T. Huynh-Dinh; J. Iafrate; D. R. Ingram; R. Inta; T. Isogai; A. Ivanov; B. R. Iyer; K. Izumi; M. Jacobson; E. James; H. Jang; Y. J. Jang; P. Jaranowski; F. Jimnez-Forteza; W. W. Johnson; D. Jones; D. I. Jones; R. Jones; R. J. G. Jonker; L. Ju; Haris K; P. Kalmus; V. Kalogera; S. Kandhasamy; G. Kang; J. B. Kanner; M. Kasprzack; R. Kasturi; E. Katsavounidis; W. Katzman; H. Kaufer; K. Kaufman; K. Kawabe

2013-09-24

179

Drawing Parallels in Search of Educational Equity: A Multicultural Education Delegation to China Looks Outside to See Within  

ERIC Educational Resources Information Center

In 2004, a professional delegation of multicultural educators visited the People's Republic of China to explore how diversity issues are addressed and how students are prepared for entry into the international workforce. The delegation, sponsored by the People to People Ambassador Programs, observed numerous parallels to the American system of

Carjuzaa, Jioanna; Fenimore-Smith, J. Kay; Fuller, Ethlyn Davis; Howe, William A.; Kugler, Eileen; London, Arcenia P.; Ruiz, Ivette; Shin, Barbara

2008-01-01

180

Status and analysis system of directional dark matter search with nuclear emulsion  

NASA Astrophysics Data System (ADS)

We have been doing research and development for direct dark matter search by nuclear emulsion which is a solid state detector. This experiment enable directional detection of dark matter with the large mass target and model independent. Until now, we constructed a base of fully automatic analysis system and nuclear emulsion which can detect sub-micron tracks. We have demonstrated that it is possible to detect recoiled tracks of 100 nm or more by neutron irradiation. This track length is correspond to 37 keV in C(N,O) target. Additionally, we evaluated the angular resolution of the energy basis by using an ion implant system, and obtained 25 degrees or better resolution in 80 keV carbon ions. The fully automatic analysis system which can analyze very short tracks lead the experiment to next phase, we will do a quantitative study of the background toward gram scale test experiment at the Gran Sasso underground laboratory.

Katsuragawa, T.; Naka, T.; Asada, T.; Yoshimoto, M.; Hakamata, K.; Ishikawa, M.

2013-12-01

181

Activity in V4 Reflects the Direction, But Not the Latency, of Saccades During Visual Search  

PubMed Central

We constantly make eye movements to bring objects of interest onto the fovea for more detailed processing. Activity in area V4, a prestriate visual area, is enhanced at the location corresponding to the target of an eye movement. However, the precise role of activity in V4 in relation to these saccades and the modulation of other cortical areas in the oculomotor system remains unknown. V4 could be a source of visual feature information used to select the eye movement, or alternatively, it could reflect the locus of spatial attention. To test these hypotheses, we trained monkeys on a visual search task in which they were free to move their eyes. We found that activity in area V4 reflected the direction of the upcoming saccade but did not predict the latency of the saccade in contrast to activity in the lateral intraparietal area (LIP). We suggest that the signals in V4, unlike those in LIP, are not directly involved in the generation of the saccade itself but rather are more closely linked to visual perception and attention. Although V4 and LIP have different roles in spatial attention and preparing eye movements, they likely perform complimentary processes during visual search. PMID:20610790

Gee, Angela L.; Ipata, Anna E.

2010-01-01

182

A Direct Dark Matter Search with the MAJORANA Low-Background Broad Energy Germanium Detector  

NASA Astrophysics Data System (ADS)

It is well established that a significant portion of our Universe is comprised of invisible, non-luminous matter, commonly referred to as dark matter. The detection and characterization of this missing matter is an active area of research in cosmology and particle astrophysics. A general class of candidates for non-baryonic particle dark matter is weakly interacting massive particles (WIMPs). WIMPs emerge naturally from supersymmetry with predicted masses between 1--1000 GeV. There are many current and near-future experiments that may shed light on the nature of dark matter by directly detecting WIMP-nucleus scattering events. The MAJORANA experiment will use p-type point contact (PPC) germanium detectors as both the source and detector to search for neutrinoless double-beta decay in 76Ge. These detectors have both exceptional energy resolution and low-energy thresholds. The low-energy performance of PPC detectors, due to their low-capacitance point-contact design, makes them suitable for direct dark matter searches. As a part of the research and development efforts for the MAJORANA experiment, a custom Canberra PPC detector has been deployed at the Kimballton Underground Research Facility in Ripplemead, Virginia. This detector has been used to perform a search for low-mass (< 10 GeV) WIMP induced nuclear recoils using a 221.49 live-day exposure. It was found that events originating near the surface of the detector plague the signal region, even after all cuts. For this reason, only an upper limit on WIMP induced nuclear recoils was placed. This limit is inconsistent with several recent claims to have observed light WIMP based dark matter.

Finnerty, Padraic Seamus

183

Quasi-steady state reduction of molecular motor-based models of directed intermittent search.  

PubMed

We present a quasi-steady state reduction of a linear reaction-hyperbolic master equation describing the directed intermittent search for a hidden target by a motor-driven particle moving on a one-dimensional filament track. The particle is injected at one end of the track and randomly switches between stationary search phases and mobile nonsearch phases that are biased in the anterograde direction. There is a finite possibility that the particle fails to find the target due to an absorbing boundary at the other end of the track. Such a scenario is exemplified by the motor-driven transport of vesicular cargo to synaptic targets located on the axon or dendrites of a neuron. The reduced model is described by a scalar Fokker-Planck (FP) equation, which has an additional inhomogeneous decay term that takes into account absorption by the target. The FP equation is used to compute the probability of finding the hidden target (hitting probability) and the corresponding conditional mean first passage time (MFPT) in terms of the effective drift velocity V, diffusivity D, and target absorption rate ? of the random search. The quasi-steady state reduction determines V, D, and ? in terms of the various biophysical parameters of the underlying motor transport model. We first apply our analysis to a simple 3-state model and show that our quasi-steady state reduction yields results that are in excellent agreement with Monte Carlo simulations of the full system under physiologically reasonable conditions. We then consider a more complex multiple motor model of bidirectional transport, in which opposing motors compete in a "tug-of-war", and use this to explore how ATP concentration might regulate the delivery of cargo to synaptic targets. PMID:20169417

Newby, Jay M; Bressloff, Paul C

2010-10-01

184

Parallel algorithm for solving Keplers equation on Graphics Processing Units: Application to analysis of Doppler exoplanet searches  

Microsoft Academic Search

We present the results of a highly parallel Kepler equation solver using the Graphics Processing Unit (GPU) on a commercial nVidia GeForce 280GTX and the Compute Unified Device Architecture (CUDA) programming environment. We apply this to evaluate a goodness-of-fit statistic (e.g., ?2) for Doppler observations of stars potentially harboring multiple planetary companions (assuming negligible planetplanet interactions). Given the high-dimensionality of

Eric B. Ford

2009-01-01

185

Parallel-hat tempering: A Monte Carlo search scheme for the identification of low-energy structures  

E-print Network

. In the first, the Boltzmann weight is modified so that the simulation can be performed as a random walk important unsolved problem in biology. According to the thermodynamic hypoth- esis of Anfinsen,1 the native­5 . A random search for the global minimum structure of a real protein is highly infeasible due

Skolnick, Jeff

186

IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS, VOL. 9, NO. 3, MARCH 1998 283 Parallel Computation  

E-print Network

performance demonstrates that parallel computational methods can significantly reduce the computational time developed parallel methods to reduce the time required to perform two com- putationally intensive analyses: homologous sequence searching and multiple sequence alignment. Our parallel searching method reduces

187

Identifying sneutrino dark matter: Interplay between the LHC and direct search  

SciTech Connect

Under R parity, the lightest supersymmetric particle (LSP) is stable and may serve as a good dark matter candidate. The R parity can be naturally introduced with a gauge origin at the TeV scale. We go over why a TeV scale B-L gauge extension of the minimal supersymmetric standard model is one of the most natural, if not demanded, low energy supersymmetric models. In the presence of a TeV scale Abelian gauge symmetry, the (predominantly) right-handed sneutrino LSP can be a good dark matter candidate. Its identification at the LHC is challenging because it does not carry any standard model charge. We show how we can use the correlation between the LHC experiments (dilepton resonance signals) and the direct dark matter search experiments (such as CDMS and XENON) to identify the right-handed sneutrino LSP dark matter in the B-L extended minimal supersymmetric standard model.

Hye-Sung L.; Li, Y.

2011-11-03

188

Identifying sneutrino dark matter: Interplay between the LHC and direct search  

SciTech Connect

Under R parity, the lightest supersymmetric particle (LSP) is stable and may serve as a good dark matter candidate. The R parity can be naturally introduced with a gauge origin at the TeV scale. We go over why a TeV scale B-L gauge extension of the minimal supersymmetric standard model is one of the most natural, if not demanded, low energy supersymmetric models. In the presence of a TeV scale Abelian gauge symmetry, the (predominantly) right-handed sneutrino LSP can be a good dark matter candidate. Its identification at the LHC is challenging because it does not carry any standard model charge. We show how we can use the correlation between the LHC experiments (dilepton resonance signals) and the direct dark matter search experiments (such as CDMS and XENON) to identify the right-handed sneutrino LSP dark matter in the B-L extended minimal supersymmetric standard model.

Lee, Hye-Sung; Li Yingchuan [Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 (United States)

2011-11-01

189

Prospects of dark matter direct search under deep sea water in India  

NASA Astrophysics Data System (ADS)

There is compelling evidence from cosmological and astrophysical observations that about one quarter of the energy density of the universe can be attributed to cold dark matter (CDM), whose nature and properties are still unknown. Around the world large numbers of experiments are using different techniques of dark matter direct and indirect detections. According to their experimental requirements location of the experiment prefer to use either underground, under ice, or under sea water. Country like India, digging underground cavern and long tunnel is not very convenient. Therefore, authors look from the either solutions of this problem preferring to use deep sea water. In this article, we discuss the pros and corns of use of deep sea water in the dark matter search.

Singh, V.; Subrahmanyam, V. S.; Singh, L.; Singh, M. K.; Sharma, V.; Chouhan, N. S.; Jaiswal, M. K.; Soma, A. K.

2013-04-01

190

Parallel MATLAB: Parallel For Loops  

E-print Network

.......... FSU: Florida State University AOE: Department of Aerospace and Ocean Engineering ARC: Advanced Research Computing ICAM: Interdisciplinary Center for Applied Mathematics 1 / 69 #12;MATLAB Parallel are completely independent; there are also some restrictions on array-data access. OpenMP implements a directive

Crawford, T. Daniel

191

Stable computation of search directions for near-degenerate linear programming problems  

SciTech Connect

In this paper, we examine stability issues that arise when computing search directions ({delta}x, {delta}y, {delta} s) for a primal-dual path-following interior point method for linear programming. The dual step {delta}y can be obtained by solving a weighted least-squares problem for which the weight matrix becomes extremely il conditioned near the boundary of the feasible region. Hough and Vavisis proposed using a type of complete orthogonal decomposition (the COD algorithm) to solve such a problem and presented stability results. The work presented here addresses the stable computation of the primal step {delta}x and the change in the dual slacks {delta}s. These directions can be obtained in a straight-forward manner, but near-degeneracy in the linear programming instance introduces ill-conditioning which can cause numerical problems in this approach. Therefore, we propose a new method of computing {delta}x and {delta}s. More specifically, this paper describes and orthogonal projection algorithm that extends the COD method. Unlike other algorithms, this method is stable for interior point methods without assuming nondegeneracy in the linear programming instance. Thus, it is more general than other algorithms on near-degenerate problems.

Hough, P.D.

1997-03-01

192

Radiopurity of CaWO$_4$ Crystals for Direct Dark Matter Search with CRESST and EURECA  

E-print Network

The direct dark matter search experiment CRESST uses scintillating CaWO$_4$ single crystals as targets for possible WIMP scatterings. An intrinsic radioactive contamination of the crystals as low as possible is crucial for the sensitivity of the detectors. In the past CaWO$_4$ crystals operated in CRESST were produced by institutes in Russia and the Ukraine. Since 2011 CaWO$_4$ crystals have also been grown at the crystal laboratory of the Technische Universit\\"at M\\"unchen (TUM) to better meet the requirements of CRESST and of the future tonne-scale multi-material experiment EURECA. The radiopurity of the raw materials and of first TUM-grown crystals was measured by ultra-low background $\\gamma$-spectrometry. Two TUM-grown crystals were also operated as low-temperature detectors at a test setup in the Gran Sasso underground laboratory. These measurements were used to determine the crystals' intrinsic $\\alpha$-activities which were compared to those of crystals produced at other institutes. The total $\\alpha$...

Mnster, A; Angloher, G; Bento, A; Bucci, C; Canonica, L; Erb, A; Feilitzsch, F v; Gorla, P; Gtlein, A; Hauff, D; Jochum, J; Kraus, H; Lanfranchi, J -C; Laubenstein, M; Loebell, J; Ortigoza, Y; Petricca, F; Potzel, W; Prbst, F; Puimedon, J; Reindl, F; Roth, S; Rottler, K; Sailer, C; Schffner, K; Schieck, J; Scholl, S; Schnert, S; Seidel, W; Stodolsky, L; Strandhagen, C; Strauss, R; Tanzke, A; Uffinger, M; Ulrich, A; Usherov, I; Wawoczny, S; Willers, M; Wstrich, M; Zller, A

2014-01-01

193

Banks of templates for directed searches of gravitational waves from spinning neutron stars  

SciTech Connect

We construct efficient banks of templates suitable for directed searches of almost monochromatic gravitational waves originating from spinning neutron stars in our Galaxy in data being collected by currently operating interferometric detectors. We thus assume that the position of the gravitational-wave source in the sky is known, but we do not assume that the wave's frequency and its derivatives are a priori known. In the construction we employ a simplified model of the signal with constant amplitude and phase which is a polynomial function of time. All our template banks enable usage of the fast Fourier transform algorithm in the computation of the maximum-likelihood F-statistic for nodes of the grids defining the bank. We study and employ the dependence of the grid's construction on the choice of the position of the observational interval with respect to the origin of time axis. We also study the usage of the fast Fourier transform algorithms with nonstandard frequency resolutions achieved by zero padding or folding the data. In the case of the gravitational-wave signal with one spin-down parameter included we have found grids with covering thicknesses which are only 0.1-16% larger than the thickness of the optimal 2-dimensional hexagonal covering.

Pisarski, Andrzej; Jaranowski, Piotr; Pietka, Maciej [Faculty of Physics, University of Bialystok, Lipowa 41, 15-424 Bialystok (Poland)

2011-02-15

194

Direct imaging search for planetary companions next to young nearby stars  

E-print Network

We report first results from our ground-based infrared imaging search for sub-stellar companions (brown dwarfs and giant planets) of young (up to 100 Myrs) nearby (up to 75 pc) stars, where companions should be well separated from the central stars and still relatively bright due to ongoing accretion and/or contraction. Among our targets are all members of the TW Hya association, as well as other binary and single young stars either discovered recently among ROSAT sources (some of which as yet unpublished) or known before. Our observations are performed mainly with SOFI and SHARP at the ESO 3.5m NTT on La Silla and with ISAAC at the ESO 8.2m Antu (VLT-UT1) on Cerro Paranal, all in the H- and K-bands. We present direct imaging data and H-band spectroscopy of a faint object detected next to TWA-7 which, if at the same age and distance as the central star, could be an object with only a few Jupiter masses. Our spectrum shows, though, that it is a background K-dwarf.

R. Neuhaeuser; E. Guenther; W. Brandner; N. Huelamo; T. Ott; J. Alves; F. Comeron; A. Eckart; J. -G. Cuby

2000-07-20

195

Direct Search for Right-handed Neutrinos and Neutrinoless Double Beta Decay  

E-print Network

We consider an extension of the Standard Model by two right-handed neutrinos, especially with masses lighter than charged $K$ meson. This simple model can realize the seesaw mechanism for neutrino masses and also the baryogenesis by flavor oscillations of right-handed neutrinos. We summarize the constraints on right-handed neutrinos from direct searches as well as the big bang nucleosynthesis. It is then found that the possible range for the quasi-degenerate mass of right-handed neutrinos is $M_N \\geq 163 \\MeV$ for normal hierarchy of neutrino masses, while $M_N = 188 \\text{--} 269 \\MeV$ and $M_N \\geq 285 \\MeV$ for inverted hierarchy case. Furthermore, we find in the latter case that the possible value of the Majorana phase is restricted for $M_N = 188 \\text{--} 350 \\MeV$, which leads to the fact that the rate of neutrinoless double beta decay is also limited.

Takehiko Asaka; Shintaro Eijima

2013-08-16

196

Radiopurity of CaWO4 crystals for direct dark matter search with CRESST and EURECA  

NASA Astrophysics Data System (ADS)

The direct dark matter search experiment CRESST uses scintillating CaWO4 single crystals as targets for possible WIMP scatterings. An intrinsic radioactive contamination of the crystals as low as possible is crucial for the sensitivity of the detectors. In the past CaWO4 crystals operated in CRESST were produced by institutes in Russia and the Ukraine. Since 2011 CaWO4 crystals have also been grown at the crystal laboratory of the Technische Universitt Mnchen (TUM) to better meet the requirements of CRESST and of the future tonne-scale multi-material experiment EURECA. The radiopurity of the raw materials and of first TUM-grown crystals was measured by ultra-low background ?-spectrometry. Two TUM-grown crystals were also operated as low-temperature detectors at a test setup in the Gran Sasso underground laboratory. These measurements were used to determine the crystals' intrinsic ?-activities which were compared to those of crystals produced at other institutes. The total ?-activities of TUM-grown crystals as low as 1.230.06 mBq/kg were found to be significantly smaller than the activities of crystals grown at other institutes typically ranging between ~ 15 mBq/kg and ~ 35 mBq/kg.

Mnster, A.; Sivers, M. v.; Angloher, G.; Bento, A.; Bucci, C.; Canonica, L.; Erb, A.; Feilitzsch, F. v.; Gorla, P.; Gtlein, A.; Hauff, D.; Jochum, J.; Kraus, H.; Lanfranchi, J.-C.; Laubenstein, M.; Loebell, J.; Ortigoza, Y.; Petricca, F.; Potzel, W.; Prbst, F.; Puimedon, J.; Reindl, F.; Roth, S.; Rottler, K.; Sailer, C.; Schffner, K.; Schieck, J.; Scholl, S.; Schnert, S.; Seidel, W.; Stodolsky, L.; Strandhagen, C.; Strauss, R.; Tanzke, A.; Uffinger, M.; Ulrich, A.; Usherov, I.; Wawoczny, S.; Willers, M.; Wstrich, M.; Zller, A.

2014-05-01

197

arXiv:hep-ph/0412300v121Dec2004 Neutrinoless double beta decay and direct searches for neutrino mass  

E-print Network

of Texas at Austin 12 Lawrence Livermore National Laboratory 13 University of California, Los Angeles 14arXiv:hep-ph/0412300v121Dec2004 Neutrinoless double beta decay and direct searches for neutrino National Laboratory 9 University of North Carolina 10 Lawrence Berkeley National Laboratory 11 University

Piepke, Andreas G.

198

Comparing the Chinese Career Key and the Self-Directed Search with High School Girls in Hong Kong  

ERIC Educational Resources Information Center

A career interest inventory, the Chinese Career Key (CCK) adapted from the Career Key based on Holland's theory of vocational choice, was studied. The purpose of the study was to further examine the psychometric qualities and user satisfaction of the CCK by comparing it to the Self-Directed Search. Students at a girls' public high school (N = 130)

Ting, Siu-Man Raymond

2007-01-01

199

Global steering of single gimballed control moment gyroscopes using a directed search  

Microsoft Academic Search

A guided depth-first search that manages null motion about torque-producing trajectories calculated with a singularity-robust inverse is proposed as a practical feedforward steering law that can globally avoid (or minimize the impact of) singular states in minimally-redundant systems of single gimballed control moment gyroscopes. Cost and heuristic functions are defined to guide the search procedure in improving gimbal trajectories. On-orbit

Joseph A. Paradiso

1992-01-01

200

A generating set direct search augmented Lagrangian algorithm for optimization with a combination of general and linear constraints.  

SciTech Connect

We consider the solution of nonlinear programs in the case where derivatives of the objective function and nonlinear constraints are unavailable. To solve such problems, we propose an adaptation of a method due to Conn, Gould, Sartenaer, and Toint that proceeds by approximately minimizing a succession of linearly constrained augmented Lagrangians. Our modification is to use a derivative-free generating set direct search algorithm to solve the linearly constrained subproblems. The stopping criterion proposed by Conn, Gould, Sartenaer and Toint for the approximate solution of the subproblems requires explicit knowledge of derivatives. Such information is presumed absent in the generating set search method we employ. Instead, we show that stationarity results for linearly constrained generating set search methods provide a derivative-free stopping criterion, based on a step-length control parameter, that is sufficient to preserve the convergence properties of the original augmented Lagrangian algorithm.

Lewis, Robert Michael (College of William and Mary, Williamsburg, VA); Torczon, Virginia Joanne (College of William and Mary, Williamsburg, VA); Kolda, Tamara Gibson

2006-08-01

201

Search for patterns by combining cosmic-ray energy and arrival directions at the Pierre Auger Observatory  

E-print Network

Energy-dependent patterns in the arrival directions of cosmic rays are searched for using data of the Pierre Auger Observatory. We investigate local regions around the highest-energy cosmic rays with $E \\geq 6 \\cdot 10^{19}$ eV by analyzing cosmic rays with energies above $E = 5 \\cdot 10^{18}$ eV arriving within an angular separation of approximately $15{\\deg}$. We characterize the energy distributions inside these regions by two independent methods, one searching for angular dependence of energy-energy correlations and one searching for collimation of energy along the local system of principal axes of the energy distribution. No significant patterns are found with this analysis. The comparison of these measurements with astrophysical scenarios can therefore be used to obtain constraints on related model parameters such as strength of cosmic-ray deflection and density of point sources.

,

2014-01-01

202

On the beam direction search space in computerized non-coplanar beam angle optimization for IMRTprostate SBRT  

NASA Astrophysics Data System (ADS)

In a recent paper, we have published a new algorithm, designated iCycle, for fully automated multi-criterial optimization of beam angles and intensity profiles. In this study, we have used this algorithm to investigate the relationship between plan quality and the extent of the beam direction search space, i.e. the set of candidate beam directions that may be selected for generating an optimal plan. For a group of ten prostate cancer patients, optimal IMRT plans were made for stereotactic body radiation therapy (SBRT), mimicking high dose rate brachytherapy dosimetry. Plans were generated for five different beam direction input sets: a coplanar (CP) set and four non-coplanar (NCP) sets. For CP treatments, the search space consisted of 72 orientations (5 separations). The NCP CyberKnife (CK) space contained all directions available in the robotic CK treatment unit. The fully non-coplanar (F-NCP) set facilitated the highest possible degree of freedom in selecting optimal directions. CK+ and CK++ were subsets of F-NCP to investigate some aspects of the CK space. For each input set, plans were generated with up to 30 selected beam directions. Generated plans were clinically acceptable, according to an assessment of our clinicians. Convergence in plan quality occurred only after around 20 included beams. For individual patients, variations in PTV dose delivery between the five generated plans were minimal, as aimed for (average spread in V95: 0.4%). This allowed plan comparisons based on organ at risk (OAR) doses, with the rectum considered most important. Plans generated with the NCP search spaces had improved OAR sparing compared to the CP search space, especially for the rectum. OAR sparing was best with the F-NCP, with reductions in rectum DMean, V40Gy, V60Gy and D2% compared to CP of 25%, 35%, 37% and 8%, respectively. Reduced rectum sparing with the CK search space compared to F-NCP could be largely compensated by expanding CK with beams with relatively large direction components along the superior-inferior axis (CK++). Addition of posterior beams (CK++ ? F-NCP) did not lead to further improvements in OAR sparing. Plans with 25 beams clearly performed better than 11-beam plans. For CP plans, an increase from 11 to 25 involved beams resulted in reductions in rectum DMean, V40Gy, V60Gy and D2% of 39%, 57%, 64% and 13%, respectively.

Rossi, Linda; Breedveld, Sebastiaan; Heijmen, Ben J. M.; Voet, Peter W. J.; Lanconelli, Nico; Aluwini, Shafak

2012-09-01

203

A search for anisotropy in the arrival directions of ultra high energy cosmic rays recorded at the Pierre Auger Observatory  

Microsoft Academic Search

Observations of cosmic ray arrival directions made with the Pierre Auger Observatory have previously provided evidence of anisotropy at the 99% CL using the correlation of ultra high energy cosmic rays (UHECRs) with objects drawn from the Vron-Cetty Vron catalog. In this paper we report on the use of three catalog independent methods to search for anisotropy. The 2ptL, 2pt+

P. Abreu; M. Aglietta; M. Ahlers; E. J. Ahn; I. F. M. Albuquerque; D. Allard; I. Allekotte; J. Allen; P. Allison; A. Almela; J. Alvarez Castillo; J. Alvarez-Muiz; M. Ambrosio; A. Aminaei; L. Anchordoqui; S. Andringa; T. Anticic; C. Aramo; E. Arganda; F. Arqueros; H. Asorey; P. Assis; J. Aublin; M. Avenier; G. Avila; T. Bcker; A. M. Badescu; M. Balzer; K. B. Barber; A. F. Barbosa; R. Bardenet; S. L. C. Barroso; B. Baughman; J. Buml; J. J. Beatty; B. R. Becker; K. H. Becker; A. Belltoile; J. A. Bellido; S. BenZvi; C. Berat; X. Bertou; P. L. Biermann; P. Billoir; F. Blanco; M. Blanco; C. Bleve; H. Blmer; M. Bohcov; D. Boncioli; C. Bonifazi; R. Bonino; N. Borodai; J. Brack; I. Brancus; P. Brogueira; W. C. Brown; R. Bruijn; P. Buchholz; A. Bueno; R. E. Burton; K. S. Caballero-Mora; B. Caccianiga; L. Caramete; R. Caruso; A. Castellina; O. Catalano; G. Cataldi; L. Cazon; R. Cester; J. Chauvin; S. H. Cheng; A. Chiavassa; J. A. Chinellato; J. Chirinos Diaz; J. Chudoba; M. Cilmo; R. W. Clay; M. R. Coluccia; R. Conceio; F. Contreras; H. Cook; M. J. Cooper; J. Coppens; A. Cordier; S. Coutu; C. E. Covault; A. Creusot; A. Criss; J. Cronin; A. Curutiu; S. Dagoret-Campagne; R. Dallier; S. Dasso; K. Daumiller; B. R. Dawson; R. M. de Almeida; M. De Domenico; C. De Donato; S. J. de Jong; G. De La Vega; I. De Mitri; V. de Souza; K. D. de Vries; L. del Peral; M. del Ro; O. Deligny; H. Dembinski; N. Dhital; C. Di Giulio; M. L. Daz Castro; P. N. Diep; F. Diogo; C. Dobrigkeit; W. Docters; J. C. DOlivo; P. N. Dong; A. Dorofeev; J. C. dos Anjos; M. T. Dova; D. DUrso; I. Dutan; J. Ebr; R. Engel; M. Erdmann; C. O. Escobar; J. Espadanal; A. Etchegoyen; P. Facal San Luis; I. Fajardo Tapia; H. Falcke; G. Farrar; A. C. Fauth; N. Fazzini; A. P. Ferguson; B. Fick; A. Filevich; A. Filipcic; S. Fliescher; C. E. Fracchiolla; E. D. Fraenkel; O. Fratu; U. Frhlich; B. Fuchs; R. Gaior; R. F. Gamarra; S. Gambetta; B. Garca; S. T. Garcia Roca; D. Garcia-Gamez; D. Garcia-Pinto; A. Gascon; H. Gemmeke; P. L. Ghia; U. Giaccari; M. Giller; H. Glass; M. S. Gold; G. Golup; F. Gomez Albarracin; M. Gmez Berisso; P. F. Gmez Vitale; P. Gonalves; D. Gonzalez; J. G. Gonzalez; B. Gookin; A. Gorgi; P. Gouffon; E. Grashorn; S. Grebe; N. Griffith; M. Grigat; A. F. Grillo; Y. Guardincerri; F. Guarino; G. P. Guedes; A. Guzman; J. D. Hague; P. Hansen; D. Harari; S. Harmsma; T. A. Harrison; J. L. Harton; A. Haungs; T. Hebbeker; D. Heck; A. E. Herve; C. Hojvat; N. Hollon; V. C. Holmes; P. Homola; J. R. Hrandel; A. Horneffer; P. Horvath; M. Hrabovsk; T. Huege; A. Insolia; F. Ionita; A. Italiano; C. Jarne; S. Jiraskova; M. Josebachuili; K. Kadija; K. H. Kampert; P. Karhan; P. Kasper; B. Kgl; B. Keilhauer; A. Keivani; J. L. Kelley; E. Kemp; R. M. Kieckhafer; H. O. Klages; M. Kleifges; J. Kleinfeller; J. Knapp; D.-H. Koang; K. Kotera; N. Krohm; O. Krmer; D. Kruppke-Hansen; F. Kuehn; D. Kuempel; J. K. Kulbartz; N. Kunka; G. La Rosa; C. Lachaud; R. Lauer; P. Lautridou; S. Le Coz; M. S. A. B. Leo; D. Lebrun; P. Lebrun; M. A. Leigui de Oliveira; A. Letessier-Selvon; I. Lhenry-Yvon; K. Link; R. Lpez; A. Lopez Agera; K. Louedec; J. Lozano Bahilo; L. Lu; A. Lucero; M. Ludwig; H. Lyberis; C. Macolino; S. Maldera; D. Mandat; P. Mantsch; A. G. Mariazzi; J. Marin; V. Marin; I. C. Maris; H. R. Marquez Falcon; G. Marsella; D. Martello; L. Martin; H. Martinez; O. Martnez Bravo; H. J. Mathes; J. Matthews; G. Matthiae; D. Maurel; D. Maurizio; P. O. Mazur; G. Medina-Tanco; M. Melissas; D. Melo; E. Menichetti; A. Menshikov; P. Mertsch; C. Meurer; S. Micanovic; M. I. Micheletti; I. A. Minaya; L. Miramonti; L. Molina-Bueno; S. Mollerach; M. Monasor; D. Monnier Ragaigne; F. Montanet; B. Morales; C. Morello; E. Moreno; J. C. Moreno; M. Mostaf; C. A. Moura; M. A. Muller; G. Mller; M. Mnchmeyer; R. Mussa; G. Navarra; J. L. Navarro; S. Navas; P. Necesal; L. Nellen; A. Nelles; J. Neuser; P. T. Nhung; M. Niechciol; L. Niemietz; N. Nierstenhoefer; D. Nitz; D. Nosek; L. Noka; M. Nyklicek; J. Oehlschlger; A. Olinto; M. Ortiz; N. Pacheco; D. Pakk Selmi-Dei; M. Palatka; J. Pallotta; N. Palmieri; G. Parente; E. Parizot; A. Parra; S. Pastor; T. Paul; M. Pech; J. Pekala; R. Pelayo; I. M. Pepe; L. Perrone; R. Pesce; E. Petermann; S. Petrera; P. Petrinca; A. Petrolini; Y. Petrov; J. Petrovic; C. Pfendner; R. Piegaia; T. Pierog; P. Pieroni; M. Pimenta; V. Pirronello; M. Platino; V. H. Ponce; M. Pontz; A. Porcelli; P. Privitera; M. Prouza; E. J. Quel; S. Querchfeld; J. Rautenberg; O. Ravel; D. Ravignani; B. Revenu; J. Ridky; S. Riggi; M. Risse; P. Ristori; H. Rivera; V. Rizi; J. Roberts; W. Rodrigues de Carvalho; G. Rodriguez; J. Rodriguez Martino; J. Rodriguez Rojo; I. Rodriguez-Cabo; M. D. Rodrguez-Fras; G. Ros; J. Rosado; T. Rossler; M. Roth; B. Rouill-dOrfeuil; E. Roulet

2012-01-01

204

Application of 3D direct PWM in parallel power quality compensators in three-phase four-wire systems  

Microsoft Academic Search

The 3D direct pulse width modulation (PWM) for three-leg centre-split voltage source inverters (VSIs) and four-leg VSIs is proposed in this paper. It can be applied to these VSIs from two-level to multi-level systems. The generalized 3D direct PWM implements the voltage synthesis in per-leg mode and it is based on the voltage second approximation as the conventional space vector

Ning-Yi Dai; Chi-Seng Lam; Man-Chung Wong; Ying-Duo Han

2008-01-01

205

A Search for Institutional Distinctiveness. New Directions for Community Colleges, Number 65.  

ERIC Educational Resources Information Center

The essays in this collection argue that community colleges have much to gain by seeking out and maintaining positive recognition of the features that distinguish them from other colleges in the region and state. In addition, the sourcebook contains articles discussing the process of conducting a search for institutional distinctiveness and ways

Townsend, Barbara K., Ed.

1989-01-01

206

Parallel algorithm development  

SciTech Connect

Rapid changes in parallel computing technology are causing significant changes in the strategies being used for parallel algorithm development. One approach is simply to write computer code in a standard language like FORTRAN 77 or with the expectation that the compiler will produce executable code that will run in parallel. The alternatives are: (1) to build explicit message passing directly into the source code; or (2) to write source code without explicit reference to message passing or parallelism, but use a general communications library to provide efficient parallel execution. Application of these strategies is illustrated with examples of codes currently under development.

Adams, T.F.

1996-06-01

207

Progression from South-Directed to Orogen-Parallel Mid-Crustal Flow on the Southern Margin of the Tibetan Plateau, Ama Drime Massif, Tibet  

NASA Astrophysics Data System (ADS)

In the South Tibetan Himalaya, two major detachment systems are exposed in the Ama Drime and Mount Everest Massifs. These structures represent a fundamental shift in the dynamics of the Himalayan orogen, recording a progression from south-directed to orogen-parallel mid-crustal flow and exhumation. The South Tibetan detachment system (STDS) accommodated exhumation of the Greater Himalayan series (GHS) until the Middle Miocene. A relatively narrow mylonite zone that progressed into a brittle detachment accommodated exhumation of the GHS. Northward, in the down-dip direction (Dzakaa Chu and Doya La), a 1-km-wide distributed zone of deformation that lacks a foliation-parallel brittle detachment characterizes the STDS. Leucogranites in the footwall of the STDS range between 17-18 Ma. Previously published 40Ar/39Ar ages suggest that movement on the STDS ended by ~ 16 Ma in Rongbuk Valley and ~ 13 Ma near Dinggye. This once continuous section of the STDS is displaced by the trans- Himalayan Ama Drime Massif and Xainza-Dinggye graben. Two oppositely dipping normal faults and shear zones that bound the Ama Drime Massif record orogen-parallel extension. During exhumation, deformation was partitioned into relatively narrow (100-300-m-thick) mylonite zones that progressed into brittle faults/detachments, which offset Quaternary deposits. U(-Th-)Pb geochronology of mafic lenses suggests that the core of the ADM reached granulite facies at ~ 15 Ma. Leucogranites in the footwall of the detachment faults range between 12-11 Ma: significantly younger than those related to movement on the STDS. Previously published 40Ar/39Ar ages from the eastern limb of the Ama Drime Massif suggest that exhumation progressed into the footwall of the Nyonno detachment between ~ 13-10 Ma. (U-Th)/He apatite ages record a minimum exhumation rate of ~ 1mm/yr between 1.5-3.0 Ma that was enhanced by focused denudation in the trans-Himalayan Arun River gorge. Together these bracket the timing (~ 12 Ma) of a transition from south-directed to orogen-parallel mid-crustal flow and associated graben formation and exhumation along the southern margin of the Tibetan Plateau.

Jessup, M. J.; Cottle, J. M.; Newell, D. L.; Berger, A. L.; Spotila, J. A.

2008-12-01

208

Heuristic optimization methods for run-time intensive models (Dynamically Dimensioned Search, Particle Swarm Optimization, GA) - a comparison of performance and parallel implementation using R  

NASA Astrophysics Data System (ADS)

Calibrating complex hydrological models faces two major challenges: firstly, extended models, especially when spatially distributed, encompass a large number of parameters with different (and possibly a-priori unknown) sensitivity. Due to the usually rough surface of the objective function, this aggravates the risk of an algorithm to converge in a local optimum. Thus, gradient-based optimization methods are often bound to fail without a very good prior estimate. Secondly, despite growing computational power, it is not uncommon that models of large extent in space or time take several minutes to run, which severely restricts the total number of model evaluations under given computational and time resources. While various heuristic methods successfully address the first challenge, they tend to conflict with the second challenge due to the increased number of evaluations necessary. In that context we analyzed three methods (Dynamically Dimensioned Search / DDS, Particle Swarm Optimization / PSO, Genetic Algorithms /GA). We performed tests with common "synthetic" objective functions and a calibration of the hydrological model WASA-SED with different number of parameters. When looking at the reduction of the objective function within few (i.e.< 1000) evaluations, the methods generally perform in the order (best to worst) DDS-PSO-GA. Only at a larger number, GA can excel. To speed up optimization, we executed DDS and PSO as parallel applications, i.e. using multiple CPUs and/or computers. The parallelisation has been implemented in the ppso-package for the free computation environment R. Special focus has been laid onto the options to resume interrupted optimization runs and visualize progress.

Francke, Till; Bronster, Axel; Shoemaker, Christine A.

2010-05-01

209

Search for direct CP violation in D0?h-h+ modes using semileptonic B decays  

NASA Astrophysics Data System (ADS)

A search for direct CP violation in D0?h-h+ (where h=K or ?) is presented using data corresponding to an integrated luminosity of 1.0 fb collected in 2011 by LHCb in pp collisions at a centre-of-mass energy of 7 TeV. The analysis uses D0 mesons produced in inclusive semileptonic b-hadron decays to the D0?X final state, where the charge of the accompanying muon is used to tag the flavour of the D0 meson. The difference in the CP-violating asymmetries between the two decay channels is measured to be ?ACP=ACP(K-K+)-ACP(?-?+)=(0.490.30 (stat)0.14 (syst))%. This result does not confirm the evidence for direct CP violation in the charm sector reported in other analyses. Difference in b-hadron mixture. Due to the momentum requirements in the trigger and selection, the relative contribution from B0 and B+ decays (the contribution from b-baryon and Bs0 decays can be neglected) can be different between the D0?K-K+ and D0??-?+ modes. In combination with a different effective production asymmetry for candidates from B0 and B+ mesons (the production asymmetry from B0 mesons is diluted due to B0 mixing) this could lead to a non-vanishing bias in ?ACP. Assuming isospin symmetry, the production cross-sections for B0 and B+ mesons are expected to be equal. Therefore, the ratio between B0 and B+ decays is primarily determined by their branching fractions to the D0?X final state. Using the inclusive branching fractions [24], B?DX, the B0 fraction is expected to be f(B0)=(37.52.9)%. From the simulation the difference in the B0 fraction due to the difference in selection efficiencies is found to be at maximum 1%. Further assuming a B+ production asymmetry of 1.0%[25] and assuming no B0 production asymmetry, the difference in the effective production asymmetry between the two modes is 0.02%. Difference in B decay time acceptance. A difference between the D0?K-K+ and D0??-?+ modes in the B decay time acceptance, in combination with B0 mixing, changes the effective B production asymmetry. Its effect is estimated from integrating the expected B decay time distributions at different starting values, such that the mean lifetime ratio corresponds to the observed B decay length difference (5%) in the two modes. Using the estimated B0 fraction and assuming a 1.0% production asymmetry, the effect on ?ACP is found to be 0.02%. Effect of the weighting procedure. After weighting the D0 distributions in pT and ?, only small differences remain in the muon kinematic distributions. In order to estimate the systematic uncertainty from the B production and detection asymmetry due to residual differences in the muon kinematic distributions, an additional weight is applied according to the muon (pT,?) and the azimuthal angle ?. The value of ?ACP changes by 0.05%. Difference in mistag asymmetry. The difference in the mistag rate between positive and negative tags contributes to the measured raw asymmetry. The mistag difference using D0?K-?+ decays is measured to be ??=(0.0060.021)% (see Section 5.2). In case ?? is different for D0?K-K+ and D0??-?+ there can be a small effect from the mistag asymmetry. A systematic uncertainty of 0.02% is assigned, coming from the uncertainty on ??. Effect of different fit models. A possible asymmetry in the background from false D0 combinations is accounted for in the fit to the D0 mass distribution. Different models can change the fraction between signal and background and therefore change the observed asymmetry. The baseline model is modified by either using a single Gaussian function for the signal, a single Gaussian plus a Crystal Ball function for the signal, a first- or second-order polynomial for the background, by leaving the asymmetry in the reflection free, or by modifying the fit range for D0??-?+ to exclude the reflection peak. The largest variation changes the value of ?ACP by 0.035%. As another check, the asymmetry is determined without any fit by counting the number of positively- and negatively-tagged events in the signal window and subtracting the corres

Aaij, R.; Abellan Beteta, C.; Adeva, B.; Adinolfi, M.; Adrover, C.; Affolder, A.; Ajaltouni, Z.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; Anderlini, L.; Anderson, J.; Andreassen, R.; Appleby, R. B.; Aquines Gutierrez, O.; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Bachmann, S.; Back, J. J.; Baesso, C.; Balagura, V.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Bauer, Th.; Bay, A.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Belogurov, S.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Benayoun, M.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bettler, M.-O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Bizzeti, A.; Bjrnstad, P. M.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Brambach, T.; van den Brand, J.; Bressieux, J.; Brett, D.; Britsch, M.; Britton, T.; Brook, N. H.; Brown, H.; Burducea, I.; Bursche, A.; Busetto, G.; Buytaert, J.; Cadeddu, S.; Callot, O.; Calvi, M.; Calvo Gomez, M.; Camboni, A.; Campana, P.; Campora Perez, D.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carranza-Mejia, H.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Cattaneo, M.; Cauet, Ch.; Charles, M.; Charpentier, Ph.; Chen, P.; Chiapolini, N.; Chrzaszcz, M.; Ciba, K.; Cid Vidal, X.; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coca, C.; Coco, V.; Cogan, J.; Cogneras, E.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Couturier, B.; Cowan, G. A.; Craik, D.; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; David, P.; David, P. N. Y.; De Bonis, I.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Silva, W.; De Simone, P.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Derkach, D.; Deschamps, O.; Dettori, F.; Dijkstra, H.; Dogaru, M.; Donleavy, S.; Dordei, F.; Dosil Surez, A.; Dossett, D.; Dovbnya, A.; Dupertuis, F.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; van Eijk, D.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Elsby, D.; Falabella, A.; Frber, C.; Fardell, G.; Farinelli, C.; Farry, S.; Fave, V.; Ferguson, D.; Fernandez Albor, V.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fitzpatrick, C.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Furcas, S.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gandelman, M.; Gandini, P.; Gao, Y.; Garofoli, J.; Garosi, P.; Garra Tico, J.; Garrido, L.; Gaspar, C.; Gauld, R.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gibson, V.; Gligorov, V. V.; Gbel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gordon, H.; Grabalosa Gndara, M.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugs, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Grnberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hampson, T.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; Hartmann, T.; He, J.; Heijne, V.; Hennessy, K.; Henrard, P.; Hernando Morata, J. A.; van Herwijnen, E.; Hicks, E.; Hill, D.; Hoballah, M.; Hombach, C.; Hopchev, P.; Hulsbergen, W.; Hunt, P.; Huse, T.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Iakovenko, V.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jans, E.; Jaton, P.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Jost, B.; Kaballo, M.; Kandybei, S.; Karacson, M.; Karbach, T. M.; Kenyon, I. R.; Kerzel, U.; Ketel, T.; Keune, A.; Khanji, B.; Kochebina, O.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Korolev, M.; Kozlinskiy, A.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucharczyk, M.; Kudryavtsev, V.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanciotti, E.; Lanfranchi, G.; Langenbruch, C.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J.-P.; Lefvre, R.; Leflat, A.; Lefranois, J.; Leo, S.; Leroy, O.; Leverington, B.; Li, Y.; Li Gioi, L.; Liles, M.; Lindner, R.; Linn, C.; Liu, B.; Liu, G.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lopez Asamar, E.; Lopez-March, N.; Lu, H.; Lucchesi, D.; Luisier, J.; Luo, H.; Machefert, F.; Machikhiliyan, I. V.; Maciuc, F.; Maev, O.; Malde, S.; Manca, G.; Mancinelli, G.; Marconi, U.; Mrki, R.; Marks, J.; Martellotti, G.; Martens, A.; Martin, L.; Martn Snchez, A.; Martinelli, M.; Martinez Santos, D.; Martins Tostes, D.; Massafferri, A.; Matev, R.; Mathe, Z.; Matteuzzi, C.; Maurice, E.; Mazurov, A.; McCarthy, J.; McNulty, R.; Mcnab, A.

2013-06-01

210

J. Parallel Distrib. Comput. 72 (2012) 231245 Contents lists available at SciVerse ScienceDirect  

E-print Network

. The problem gets complicated further when external requests have different QoS requirements. Serving local, local users in each cluster send their requests directly to the local resource manager (LRM and external users. As illustrated in Fig. 1, local users (hereafter termed as local requests), refer to users

Buyya, Rajkumar

211

A NEW SEARCH FOR DIRECT CP VIOLATION IN HYPERON DECAYS K. S. NELSON  

E-print Network

The HyperCP experiment 1 (Fermilab E871) is performing a search for CP violation in \\Xi and \\Lambda hyperon­specific parameters a governing the angular distribution of the baryon; ff = 2Re(S \\Lambda P ) jSj 2 + jP j 2 ; fi = 2 considered three asymmetries sen­ sitive to CP odd effects that can be formed from the 1 #12; Table 1: Some

Fermilab Experiment E871

212

How choosy should I be? The relative searching time predicts evolution of choosiness under direct sexual selection  

PubMed Central

Most theoretical research in sexual selection has focused on indirect selection. However, empirical studies have not strongly supported indirect selection. A well-established finding is that direct benefits and costs exert a strong influence on the evolution of mate choice. We present an analytical model in which unilateral mate choice evolves solely by direct sexual selection on choosiness. We show this is sufficient to generate the evolution of all possible levels of choosiness, because of the fundamental trade-off between mating rate and mating benefits. We further identify the relative searching time (RST, i.e. the proportion of lifetime devoted to searching for mates) as a predictor of the effect of any variable affecting the mating rate on the evolution of choosiness. We show that the RST: (i) allows one to make predictions about the evolution of choosiness across a wide variety of mating systems; (ii) encompasses all alternative variables proposed thus far to explain the evolution of choosiness by direct sexual selection; and (iii) can be empirically used to infer qualitative differences in choosiness. PMID:24789896

Etienne, Loc; Rousset, Franois; Godelle, Bernard; Courtiol, Alexandre

2014-01-01

213

Parallel processing  

SciTech Connect

This book provides a introduction to the fundamental principles and practice of parallel processing. After a general introduction to the many facets of parallelism, the first part of the book is devoted to the development of a coherent theoretical framework. Particular attention is paid to the modeling, semantics and complexity of interacting parallel processes. The second part of the book considers the more practical aspects such as parallel processor architecture, parallel and distributed programming, and concurrent transaction handling in databases.

Krishnamurthy, E.V. (Waikato Univ., Hamilton (New Zealand))

1989-01-01

214

Massively parallel electron beam direct writing (MPEBDW) system based on micro-electro-mechanical system (MEMS)/nanocrystalineSi emitter array  

NASA Astrophysics Data System (ADS)

The characteristics of a prototype massively parallel electron beam direct writing (MPEBDW) system are demonstrated. The electron optics consist of an emitter array, a micro-electro-mechanical system (MEMS) condenser lens array, auxiliary lenses, a stigmator, three-stage deflectors to align and scan the parallel beams, and an objective lens acting as a reduction lens. The emitter array produces 10000 programmable 10 ?m square beams. The electron emitter is a nanocrystalline silicon (nc-Si) ballistic electron emitter array integrated with an active matrix driver LSI for high-speed emission current control. Because the LSI also has a field curvature correction function, the system can use a large electron emitter array. In this system, beams that are incident on the outside of the paraxial region of the reduction lens can also be used through use of the optical aberration correction functions. The exposure pattern is stored in the active matrix LSI's memory. Alignment between the emitter array and the condenser lens array is performed by moving the emitter stage that slides along the x- and y-axes, and rotates around the z-theta axis. The electrons of all beams are accelerated, and pass through the anode array. The stigmator and the two-stage deflectors perform fine adjustments to the beam positions. The other deflector simultaneously scans all parallel beams to synchronize the moving target stage. Exposure is carried out by moving the target stage that holds the wafer. The reduction lens focuses all beams on the target wafer surface, and the electron optics of the column reduces the electron image to 0.1% of its original size.

Kojima, A.; Ikegami, N.; Yoshida, T.; Miyaguchi, H.; Muroyama, M.; Nishino, H.; Yoshida, S.; Sugata, M.; Ohyi, H.; Koshida, N.; Esashi, M.

2014-03-01

215

First measurement of the Head-Tail directional nuclear recoil signature at energies relevant to WIMP dark matter searches  

E-print Network

We present first evidence for the so-called Head-Tail asymmetry signature of neutron-induced nuclear recoil tracks at energies down to 1.5 keV/amu using the 1m^3 DRIFT-IIc dark matter detector. This regime is appropriate for recoils induced by Weakly Interacting Massive Particle (WIMPs) but one where the differential ionization is poorly understood. We show that the distribution of recoil energies and directions induced here by Cf-252 neutrons matches well that expected from massive WIMPs. The results open a powerful new means of searching for a galactic signature from WIMPs.

S. Burgos; E. Daw; J. Forbes; C. Ghag; M. Gold; C. Hagemann; V. A. Kudryavtsev; T. B. Lawson; D. Loomba; P. Majewski; D. Muna; A. StJ. Murphy; G. G. Nicklin; S. M. Paling; A. Petkov; S. J. S. Plank; M. Robinson; N. Sanghi; D. P. Snowden-Ifft; N. J. C. Spooner; J. Turk; E. Tziaferi

2008-09-10

216

Icarus: A 2D direct simulation Monte Carlo (DSMC) code for parallel computers. User`s manual - V.3.0  

SciTech Connect

Icarus is a 2D Direct Simulation Monte Carlo (DSMC) code which has been optimized for the parallel computing environment. The code is based on the DSMC method of Bird and models from free-molecular to continuum flowfields in either cartesian (x, y) or axisymmetric (z, r) coordinates. Computational particles, representing a given number of molecules or atoms, are tracked as they have collisions with other particles or surfaces. Multiple species, internal energy modes (rotation and vibration), chemistry, and ion transport are modelled. A new trace species methodology for collisions and chemistry is used to obtain statistics for small species concentrations. Gas phase chemistry is modelled using steric factors derived from Arrhenius reaction rates. Surface chemistry is modelled with surface reaction probabilities. The electron number density is either a fixed external generated field or determined using a local charge neutrality assumption. Ion chemistry is modelled with electron impact chemistry rates and charge exchange reactions. Coulomb collision cross-sections are used instead of Variable Hard Sphere values for ion-ion interactions. The electrostatic fields can either be externally input or internally generated using a Langmuir-Tonks model. The Icarus software package includes the grid generation, parallel processor decomposition, postprocessing, and restart software. The commercial graphics package, Tecplot, is used for graphics display. The majority of the software packages are written in standard Fortran.

Bartel, T.; Plimpton, S.; Johannes, J.; Payne, J.

1996-10-01

217

SEARCH FOR A CORRELATION BETWEEN ANTARES NEUTRINOS AND PIERRE AUGER OBSERVATORY UHECRs ARRIVAL DIRECTIONS  

SciTech Connect

A multimessenger analysis optimized for a correlation of arrival directions of ultra-high energy cosmic rays (UHECRs) and neutrinos is presented and applied to 2190 neutrino candidate events detected in 2007-2008 by the ANTARES telescope and 69 UHECRs observed by the Pierre Auger Observatory between 2004 January 1 and 2009 December 31. No significant correlation is observed. Assuming an equal neutrino flux (E {sup -2} energy spectrum) from all UHECR directions, a 90% CL upper limit on the neutrino flux of 5.0 Multiplication-Sign 10{sup -8} GeV cm{sup -2} s{sup -1} per source is derived.

Adrian-Martinez, S.; Ardid, M.; Bou-Cabo, M. [Institut d'Investigacio per a la Gestio Integrada de les Zones Costaneres (IGIC), Universitat Politecnica de Valencia, C/ Paranimf 1, E-46730 Gandia (Spain); Al Samarai, I.; Aubert, J-J.; Bertin, V. [CPPM, Aix-Marseille Universite, CNRS/IN2P3, F-13288 Marseille (France); Albert, A. [GRPHE-Institut universitaire de technologie de Colmar, 34 rue du Grillenbreit BP 50568-68008 Colmar (France); Andre, M. [Laboratory of Applied Bioacoustics, Technical University of Catalonia, Rambla Exposicio, E-08800 Vilanova i la Geltru, Barcelona (Spain); Anghinolfi, M. [INFN-Sezione di Genova, Via Dodecaneso 33, I-16146 Genova (Italy); Anton, G. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, D-91058 Erlangen (Germany); Anvar, S. [Direction des Sciences de la Matiere, Institut de recherche sur les lois fondamentales de l'Univers, Service d'Electronique des Detecteurs et d'Informatique, CEA Saclay, F-91191 Gif-sur-Yvette Cedex (France); Astraatmadja, T.; Beemster, L. J.; Bogazzi, C.; Bouwhuis, M. C. [Nikhef, Science Park, Amsterdam (Netherlands); Baret, B.; Bouhou, B. [APC-Laboratoire AstroParticule et Cosmologie, UMR 7164 (CNRS, Universite Paris 7 Diderot, CEA, Observatoire de Paris) 10, rue Alice Domon et Leonie Duquet, F-75205 Paris Cedex 13 (France); Basa, S. [LAM-Laboratoire d'Astrophysique de Marseille, Pole de l'Etoile Site de Chateau-Gombert, rue Frederic Joliot-Curie 38, F-13388 Marseille Cedex 13 (France); Biagi, S. [INFN-Sezione di Bologna, Viale Berti-Pichat 6/2, I-40127 Bologna (Italy); Bigongiari, C. [IFIC-Instituto de Fisica Corpuscular, Edificios Investigacion de Paterna CSIC, Universitat de Valencia, Apdo. de Correos 22085, E-46071 Valencia (Spain); and others

2013-09-01

218

Direct dark matter search program with bolometers at the University of Tokyo  

NASA Astrophysics Data System (ADS)

Bolometers are being developed at the University of Tokyo aiming at a search for galactic dark matter. We have succeeded in constructing a small-sized bolometer with 2.8 gram of lithium fluoride crystal with an rms energy resolution of 3.8 ke V for 60-ke V ? rays. Both lithium and fluorine are expected to be suitable for the detection of possible particle dark matter with a spin-dependent interaction like supersymmetric neutralinos. Fabrication of Neutron Transmutation Doped (NTD) germanium is also in progress to make a number of thermistors with uniform sensitivities to be used for multi-module bolometers. When the development of a full-sized detector with a total mass of order one kilogram is completed, we plan to install it in the Kamioka underground laboratory.

Minowa, Makoto; Ito, Yutaka; Ootani, Wataru; Nishigaki, Keiji; Watanabe, Takayuki; Ootuka, Youiti

1993-11-01

219

High resolution direction of arrival (DOA) estimation based on improved orthogonal matching pursuit (OMP) algorithm by iterative local searching.  

PubMed

DOA (Direction of Arrival) estimation is a major problem in array signal processing applications. Recently, compressive sensing algorithms, including convex relaxation algorithms and greedy algorithms, have been recognized as a kind of novel DOA estimation algorithm. However, the success of these algorithms is limited by the RIP (Restricted Isometry Property) condition or the mutual coherence of measurement matrix. In the DOA estimation problem, the columns of measurement matrix are steering vectors corresponding to different DOAs. Thus, it violates the mutual coherence condition. The situation gets worse when there are two sources from two adjacent DOAs. In this paper, an algorithm based on OMP (Orthogonal Matching Pursuit), called ILS-OMP (Iterative Local Searching-Orthogonal Matching Pursuit), is proposed to improve DOA resolution by Iterative Local Searching. Firstly, the conventional OMP algorithm is used to obtain initial estimated DOAs. Then, in each iteration, a local searching process for every estimated DOA is utilized to find a new DOA in a given DOA set to further decrease the residual. Additionally, the estimated DOAs are updated by substituting the initial DOA with the new one. The simulation results demonstrate the advantages of the proposed algorithm. PMID:23974150

Wang, Wenyi; Wu, Renbiao

2013-01-01

220

Bacterial productivity in the water column and sediments of the Georgia (USA) coastal zone: Estimates via direct counting and parallel measurement of thymidine incorporation.  

PubMed

Three methods of estimating bacterial productivity were compared using parallel samples of Atlantic Ocean water (within 0.25-15 km of the Georgia coast). The frequency-of-dividing cells (FDC) method and the [(3)H]thymidine incorporation method gave results which were strongly correlated (r=0.97), but the FDC estimates were always higher (X2 to X7) than the [(3)H]thymidine estimates. Estimates of bacterial productivity ranged from 2-410(8) cellsl(-1)h(-1) at 0.25 km from shore to 1-910(7)cellsl(-1)h(-1) at 15 km. A method involving incubation of 3-?m filtrates and direct counting gave results that could not be easily translated into estimates of bacterial productivity. Application of the FDC method to sediment samples gave high productivity estimates, which could be not reconciled with productivity estimates based on sediment oxygen uptake. PMID:24225696

Newell, S Y; Fallon, R D

1982-06-01

221

Supermassive Black Hole Binaries in High Performance Massively Parallel Direct N-body Simulations on Large GPU Clusters  

NASA Astrophysics Data System (ADS)

Astrophysical Computer Simulations of Dense Star Clusters in Galactic Nuclei with Supermassive Black Holes are presented using new cost-efficient supercomputers in China accelerated by graphical processing cards (GPU). We use large high-accuracy direct N-body simulations with Hermite scheme and block-time steps, parallelised across a large number of nodes on the large scale and across many GPU thread processors on each node on the small scale. A sustained performance of more than 350 Tflop/s for a science run on using simultaneously 1600 Fermi C2050 GPUs is reached; a detailed performance model is presented and studies for the largest GPU clusters in China with up to Petaflop/s performance and 7000 Fermi GPU cards. In our case study we look at two supermassive black holes with equal and unequal masses embedded in a dense stellar cluster in a galactic nucleus. The hardening processes due to interactions between black holes and stars, effects of rotation in the stellar system and relativistic forces between the black holes are simultaneously taken into account. The simulation stops at the complete relativistic merger of the black holes.

Spurzem, R.; Berczik, P.; Zhong, S.; Nitadori, K.; Hamada, T.; Berentzen, I.; Veles, A.

2012-07-01

222

Fourier Analysis of Gamma-Ray Burst Light Curves: Searching for Direct Signature of Cosmological Time Dilation  

E-print Network

We study the power density spectrum (PDS) of light curves of the observed gamma-ray bursts (GRBs) to search for a direct signature for cosmological time dilation in the PDS statistics with the GRBs whose redshifts $z$'s are known. The anticorrelation of a timescale measure and a brightness measure is indirect evidence of its effect. On the other hand, we directly demonstrate that a time dilation effect can be seen in GRB light curves. We find that timescales tend to be shorter in bursts with small redshift, as expected from cosmological time-dilation effects, and we also find that there may be non-cosmological effects constituting to this correlation. We discuss its implication on interpretations of the PDS analysis results. We put forward another caution to this kind of analysis when we statistically exercise with GRBs whose $z$ is unknown.

Heon-Young Chang

2001-06-13

223

Search for signatures of magnetically-induced alignment in the arrival directions measured by the Pierre Auger Observatory  

NASA Astrophysics Data System (ADS)

We present the results of an analysis of data recorded at the Pierre Auger Observatory in which we search for groups of directionally-aligned events (or 'multiplets') which exhibit a correlation between arrival direction and the inverse of the energy. These signatures are expected from sets of events coming from the same source after having been deflected by intervening coherent magnetic fields. The observation of several events from the same source would open the possibility to accurately reconstruct the position of the source and also measure the integral of the component of the magnetic field orthogonal to the trajectory of the cosmic rays. We describe the largest multiplets found and compute the probability that they appeared by chance from an isotropic distribution. We find no statistically significant evidence for the presence of multiplets arising from magnetic deflections in the present data.

Pierre Auger Collaboration; Abreu, P.; Aglietta, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez Castillo, J.; Alvarez-Muiz, J.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Anti?i?, T.; Anzalone, A.; Aramo, C.; Arganda, E.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Bcker, T.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Barroso, S. L. C.; Baughman, B.; Buml, J.; Beatty, J. J.; Becker, B. R.; Becker, K. H.; Belltoile, A.; Bellido, J. A.; Benzvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blmer, H.; Boh?ov, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Burton, R. E.; Caballero-Mora, K. S.; Caramete, L.; Caruso, R.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chou, A.; Chudoba, J.; Clay, R. W.; Coluccia, M. R.; Conceio, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coppens, J.; Cordier, A.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Dallier, R.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; de Domenico, M.; de Donato, C.; de Jong, S. J.; de La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; de Mitri, I.; de Souza, V.; de Vries, K. D.; Decerprit, G.; Del Peral, L.; Del Ro, M.; Deligny, O.; Dembinski, H.; Dhital, N.; di Giulio, C.; Diaz, J. C.; Daz Castro, M. L.; Diep, P. N.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; Dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Fajardo Tapia, I.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Ferrero, A.; Fick, B.; Filevich, A.; Filip?i?, A.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Frhlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; Garca, B.; Garca Gmez, D.; Garcia-Pinto, D.; Gascon, A.; Gemmeke, H.; Gesterling, K.; Ghia, P. L.; Giaccari, U.; Giller, M.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gmez Berisso, M.; Gonalves, P.; Gonzalez, D.; Gonzalez, J. G.; Gookin, B.; Gra, D.; Gorgi, A.; Gouffon, P.; Gozzini, S. R.; Grashorn, E.; Grebe, S.; Griffith, N.; Grigat, M.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Guzman, A.; Hague, J. D.; Hansen, P.; Harari, D.; Harmsma, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Hrandel, J. R.; Horneffer, A.; Hrabovsk, M.; Huege, T.; Insolia, A.; Ionita, F.; Italiano, A.; Jarne, C.; Jiraskova, S.; Josebachuili, M.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Kgl, B.; Keilhauer, B.; Keivani, A.; Kelley, J. L.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Koang, D.-H.; Kotera, K.; Krohm, N.; Krmer, O.; Kruppke-Hansen, D.; Kuehn, F.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; Lachaud, C.; Lautridou, P.; Leo, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Lemiere, A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lpez, R.; Lopez Agera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Maldera, S.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, J.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martnez Bravo, O.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Mertsch, P.; Meurer, C.; Mi?anovi?, S.; Micheletti, M. I.; Miller, W.; Miramonti, L.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Morris, C.; Mostaf, M.; Moura, C. A.; Mueller, S.; Muller, M. A.; Mller, G.; Mnchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nhung, P. T.; Niemietz, L.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Noka, L.; Nyklicek, M.; Oehlschlger, J.; Olinto, A.; Oliva, P.; Olmos-Gilbaja, V. M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parra, A.; Parsons, R. D.; Pastor, S.; Paul, T.; Pech, M.; Pe?ala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrinca, P.; Petrolini, A.; Petrov, Y.; Petrovic, J.; Pfendner, C.

2012-01-01

224

Search for signatures of magnetically-induced alignment in the arrival directions measured by the Pierre Auger Observatory  

SciTech Connect

We present the results of an analysis of data recorded at the Pierre Auger Observatory in which we search for groups of directionally-aligned events (or ''multiplets'') which exhibit a correlation between arrival direction and the inverse of the energy. These signatures are expected from sets of events coming from the same source after having been deflected by intervening coherent magnetic fields. The observation of several events from the same source would open the possibility to accurately reconstruct the position of the source and also measure the integral of the component of the magnetic field orthogonal to the trajectory of the cosmic rays. We describe the largest multiplets found and compute the probability that they appeared by chance from an isotropic distribution. We find no statistically significant evidence for the presence of multiplets arising from magnetic deflections in the present data.

Abreu, P.; /Lisbon, IST; Aglietta, M.; /Turin U. /INFN, Turin; Ahn, E.J.; /Fermilab; Albuquerque, I.F.M.; /Sao Paulo U.; Allard, D.; /APC, Paris; Allekotte, I.; /Buenos Aires, CONICET; Allen, J.; /New York U.; Allison, P.; /Ohio State U.; Alvarez Castillo, J.; /Mexico U., ICN; Alvarez-Muniz, J.; /Santiago de Compostela U.; Ambrosio, M.; /Naples U. /INFN, Naples /Nijmegen U., IMAPP

2011-11-01

225

Formalizing Dependency Directed Backtracking and Explanation Based Learning in Refinement Search  

E-print Network

-to been incomparable. My motivation in this paper is to put the different ideas and approaches related 85287, rao@asu.edu Abstract The ideas of dependency directed backtracking (DDB) and explanation based communities. In this paper, I formalize and unify these ideas under the task-independent frame- work

Kambhampati, Subbarao

226

Collective cargo hauling by a bundle of parallel microtubules: bi-directional motion caused by load-dependent polymerization and depolymerization  

E-print Network

A microtubule (MT) is a hollow tube of approximately 25 nm diameter. The two ends of the tube are dissimilar and are designated as `plus' and `minus' ends. Motivated by the collective push and pull exerted by a bundle of MTs during chromosome segregation in a living cell, we have developed here a much simplified theoretical model of a bundle of parallel dynamic MTs. The plus-end of all the MTs in the bundle are permanently attached to a movable `wall' by a device whose detailed structure is not treated explicitly in our model. The only requirement is that the device allows polymerization and depolymerization of each MT at the plus-end. In spite of the absence of external force and direct lateral interactions between the MTs, the group of polymerizing MTs attached to the wall create a load force against the group of depolymerizing MTs and vice-versa; the load against a group is shared equally by the members of that group. Such indirect interactions among the MTs gives rise to the rich variety of possible states of collective dynamics that we have identified by computer simulations of the model in different parameter regimes. The bi-directional motion of the cargo, caused by the load-dependence of the polymerization kinetics, is a "proof-of-principle" that the bi-directional motion of chromosomes before cell division does not necessarily need active participation of motor proteins.

Dipanwita Ghanti; Debashish Chowdhury

2014-09-15

227

A Massively Parallel Hybrid Dusty-Gasdynamics and Kinetic Direct Simulation Monte Carlo Model for Planetary Applications  

NASA Technical Reports Server (NTRS)

In order to understand the global structure, dynamics, and physical and chemical processes occurring in the upper atmospheres, exospheres, and ionospheres of the Earth, the other planets, comets and planetary satellites and their interactions with their outer particles and fields environs, it is often necessary to address the fundamentally non-equilibrium aspects of the physical environment. These are regions where complex chemistry, energetics, and electromagnetic field influences are important. Traditional approaches are based largely on hydrodynamic or magnetohydrodynamic (MHD) formulations and are very important and highly useful. However, these methods often have limitations in rarefied physical regimes where the molecular collision rates and ion gyrofrequencies are small and where interactions with ionospheres and upper neutral atmospheres are important. At the University of Michigan we have an established base of experience and expertise in numerical simulations based on particle codes which address these physical regimes. The Principal Investigator, Dr. Michael Combi, has over 20 years of experience in the development of particle-kinetic and hybrid kinetichydrodynamics models and their direct use in data analysis. He has also worked in ground-based and space-based remote observational work and on spacecraft instrument teams. His research has involved studies of cometary atmospheres and ionospheres and their interaction with the solar wind, the neutral gas clouds escaping from Jupiter s moon Io, the interaction of the atmospheres/ionospheres of Io and Europa with Jupiter s corotating magnetosphere, as well as Earth s ionosphere. This report describes our progress during the year. The contained in section 2 of this report will serve as the basis of a paper describing the method and its application to the cometary coma that will be continued under a research and analysis grant that supports various applications of theoretical comet models to understanding the inner comae of comets (grant NAGS- 13239 from the Planetary Atmospheres program).

Combi, Michael R.

2004-01-01

228

Self-Administration and Scoring Errors of Learning Disabled and Non Learning Disabled Students on Two Forms of the Self-Directed Search  

Microsoft Academic Search

The number and type of errors in self-administration and scoring made on Holland's Self-Directed Search (SDS) and Self-Directed Search Form Easy (SDSE) were examined. Subjects were 96 learning disabled and 96 non learning disabled high school students matched on socioeconomic status, sex, and ethnicity. Both groups of subjects made more errors on the SDS than on the SDSE. However, for

Rhoda W. Cummings; Cleborne D. Maddux

1987-01-01

229

Direct imaging search for planets around low-mass stars and spectroscopic characterization of young exoplanets  

NASA Astrophysics Data System (ADS)

Low--mass stars between 0.1--0.6 M? are the most abundant members our galaxy and may be the most common sites of planet formation, but little is known about the outer architecture of their planetary systems. We have carried out a high-contrast adaptive imaging search for gas giant planets between 1--13 MJup around 122 newly identified young M dwarfs in the solar neighborhood ( ? 35 pc). Half of our targets are younger than 145 Myr, and 90% are younger than 580 Myr. After removing 39 resolved stellar binaries, our homogeneous sample of 83 single young M dwarfs makes it the largest imaging search for planets around low--mass stars to date. Our H- and K- band coronagraphic observations with Subaru/HiCIAO and Keck/NIRC2 achieve typical contrasts of 9--13 mag and 12--14 mag at 100, respectively, which corresponds to limiting masses of 1--10 M Jup at 10--30 AU for most of our sample. We discovered four brown dwarfs with masses between 25--60 MJup at projected separations of 4--190 AU. Over 100 candidate planets were discovered, nearly all of which were found to be background stars from follow-up second epoch imaging. Our null detection of planets nevertheless provides strong statistical constraints on the occurrence rate of giant planets around M dwarfs. Assuming circular orbits and a logarithmically-flat power law distribution in planet mass and semi--major axis of the form d 2N=(dloga dlogm) infinity m0 a0, we measure an upper limit (at the 95% confidence level) of 8.8% and 12.6% for 1--13 MJup companions between 10--100 AU for hot start and cold start evolutionary models, respectively. For massive gas giant planets in the 5--13 M Jup range like those orbiting HR 8799, GJ 504, and beta Pictoris, we find that fewer than 5.3% (7.8%) of M dwarfs harbor these planets between 10--100 AU for a hot start (cold start) formation scenario. Our best constraints are for brown dwarf companions; the frequency of 13--75 MJup companions between (de--projected) physical separations of 10--100 AU is 2.1+2.1-1.2 %. Altogether, our results show that gas giant planets, especially massive ones, are rare in the outskirts of M dwarf planetary systems. If disk instability is a viable way to form planets, our constraints for the most common type of star imply that overall it is an inefficient mechanism.

Bowler, Brendan Peter

230

Future Directions in the Microwave Cavity Search for Dark Matter Axions  

E-print Network

The axion is a light pseudoscalar particle which suppresses CP-violating effects in strong interactions and also happens to be an excellent dark matter candidate. Axions constituting the dark matter halo of our galaxy may be detected by their resonant conversion to photons in a microwave cavity permeated by a magnetic field. The current generation of the microwave cavity experiment has demonstrated sensitivity to plausible axion models, and upgrades in progress should achieve the sensitivity required for a definitive search, at least for low mass axions. However, a comprehensive strategy for scanning the entire mass range, from 1-1000 $\\mu$eV, will require significant technological advances to maintain the needed sensitivity at higher frequencies. Such advances could include sub-quantum-limited amplifiers based on squeezed vacuum states, bolometers, and/or superconducting microwave cavities. The Axion Dark Matter eXperiment at High Frequencies (ADMX-HF) represents both a pathfinder for first data in the 20-100 $\\mu$eV range ($\\sim$5-25 GHz), and an innovation test-bed for these concepts.

T. M. Shokair; J. Root; K. A. Van Bibber; B. Brubaker; Y. V. Gurevich; S. B. Cahn; S. K. Lamoreaux; M. A. Anil; K. W. Lehnert; B. K. Mitchell; A. Reed; G. Carosi

2014-05-14

231

A NICMOS Direct Imaging Search for Giant Planets around the Single White Dwarfs in the Hyades  

E-print Network

We report preliminary results from our search for massive giant planets (6-12 Jupiter masses) around the known seven single white dwarfs in the Hyades cluster at sub-arcsec separations. At an age of 625 Myr, the white dwarfs had progenitor masses of about 3 solar masses, and massive gaseous giant planets should have formed in the massive circumstellar disks around these ex-Herbig A0 stars, probably at orbital separations similar or slightly larger than that of Jupiter. Such planets would have survived the post-Main-Sequence mass loss of the parent star and would have migrated outward adiabatically to a distance of about 25 AU. At the distance of the Hyades (45 pc) this corresponds to an angular separation of 0.5 arcsec. J and H magnitudes of these giants are in the range of 20.5-23.3 mag, which can be resolved with NICMOS. The achieved sensitivities and contrast ratios agree well with simulations. Preliminary evaluation of the NICMOS data set did not reveal any evidence for neither planetary mass companions with masses down to about 10 Jupiter masses nor brown dwarfs around any of the seven white dwarfs for separations larger than 0.5 arcsec.

S. Friedrich; H. Zinnecker; W. Brandner; S. Correia; M. McCaughrean

2005-01-10

232

Impact of dark matter direct searches and the LHC analyses on branon phenomenology  

SciTech Connect

Dark Matter direct detection experiments are able to exclude interesting parameter space regions of particle models which predict an important amount of thermal relics. We use recent data to constrain the branon model and to compute the region that is favored by CDMS measurements. Within this work, we also update present colliders constraints with new studies coming from the LHC. Despite the present low luminosity, it is remarkable that for heavy branons, CMS and ATLAS measurements are already more constraining than previous analyses performed with TEVATRON and LEP data.

Cembranos, Jose A. R. [Departamento de Fisica Teorica I, Universidad Complutense de Madrid, E-28040 (Spain); Diaz-Cruz, J. Lorenzo; Prado, Lilian [Facultad de Ciencias Fisico-Matematicas, Benemerita Universidad Autonoma de Puebla, C. P. 72570, Puebla, Pue. (Mexico)

2011-10-15

233

Lost in space? Searching for directions in the spatial modelling of individuals, populations and species ranges  

PubMed Central

The workshop Spatial models in animal ecology, management and conservation held at Silwood Park (UK), 911 March 2010, aimed to synthesize recent progress in modelling the spatial dynamics of individuals, populations and species ranges and to provide directions for research. It brought together marine and terrestrial researchers working on spatial models at different levels of organization, using empirical as well as theory-driven approaches. Different approaches, temporal and spatial scales, and practical constraints predominate at different levels of organization and in different environments. However, there are theoretical concepts and specific methods that can fruitfully be transferred across levels and systems, including: habitat suitability characterization, movement rules, and ways of estimating uncertainty. PMID:20484232

Struve, Juliane; Lorenzen, Kai; Blanchard, Julia; Brger, Luca; Bunnefeld, Nils; Edwards, Charles; Hortal, Joaqun; MacCall, Alec; Matthiopoulos, Jason; Van Moorter, Bram; Ozgul, Arpat; Royer, Franois; Singh, Navinder; Yesson, Chris; Bernard, Rodolphe

2010-01-01

234

Global interpretation of direct Dark Matter searches after CDMS-II results  

SciTech Connect

We perform a global fit to data from Dark Matter (DM) direct detection experiments, including the recent CDMS-II results. We discuss possible interpretations of the DAMA annual modulation signal in terms of spin-independent and spin-dependent DM-nucleus interactions, both for elastic and inelastic scattering. We find that for the spin-dependent inelastic scattering off protons a good fit to all data is obtained. We present a simple toy model realizing such a scenario. In all the remaining cases the DAMA allowed regions are disfavored by other experiments or suffer from severe fine tuning of DM parameters with respect to the galactic escape velocity. Finally, we also entertain the possibility that the two events observed in CDMS-II are an actual signal of elastic DM scattering, and we compare the resulting CDMS-II allowed regions to the exclusion limits from other experiments.

Kopp, Joachim; Schwetz, Thomas; Zupan, Jure

2009-12-01

235

SEEK: A FORTRAN optimization program using a feasible directions gradient search  

NASA Technical Reports Server (NTRS)

This report describes the use of computer program 'SEEK' which works in conjunction with two user-written subroutines and an input data file to perform an optimization procedure on a user's problem. The optimization method uses a modified feasible directions gradient technique. SEEK is written in ANSI standard Fortran 77, has an object size of about 46K bytes, and can be used on a personal computer running DOS. This report describes the use of the program and discusses the optimizing method. The program use is illustrated with four example problems: a bushing design, a helical coil spring design, a gear mesh design, and a two-parameter Weibull life-reliability curve fit.

Savage, M.

1995-01-01

236

Should ground-motion records be rotated to fault-normal/parallel or maximum direction for response history analysis of buildings?  

USGS Publications Warehouse

In the United States, regulatory seismic codes (for example, California Building Code) require at least two sets of horizontal ground-motion components for three-dimensional (3D) response history analysis (RHA) of building structures. For sites within 5 kilometers (3.1 miles) of an active fault, these records should be rotated to fault-normal and fault-parallel (FN/FP) directions, and two RHAs should be performed separatelywhen FN and then FP direction are aligned with transverse direction of the building axes. This approach is assumed to lead to two sets of responses that envelope the range of possible responses over all nonredundant rotation angles. The validity of this assumption is examined here using 3D computer models of single-story structures having symmetric (torsionally stiff) and asymmetric (torsionally flexible) layouts subjected to an ensemble of near-fault ground motions with and without apparent velocity pulses. In this parametric study, the elastic vibration period is varied from 0.2 to 5 seconds, and yield-strength reduction factors, R, are varied from a value that leads to linear-elastic design to 3 and 5. Further validations are performed using 3D computer models of 9-story structures having symmetric and asymmetric layouts subjected to the same ground-motion set. The influence of the ground-motion rotation angle on several engineering demand parameters (EDPs) is examined in both linear-elastic and nonlinear-inelastic domains to form benchmarks for evaluating the use of the FN/FP directions and also the maximum direction (MD). The MD ground motion is a new definition for horizontal ground motions for use in site-specific ground-motion procedures for seismic design according to provisions of the American Society of Civil Engineers/Seismic Engineering Institute (ASCE/SEI) 7-10. The results of this study have important implications for current practice, suggesting that ground motions rotated to MD or FN/FP directions do not necessarily provide the most critical EDPs in nonlinear-inelastic domain; however, they tend to produce larger EDPs than as-recorded (arbitrarily oriented) motions.

Reyes, Juan C.; Kalkan, Erol

2012-01-01

237

Measurement and modeling of muon-induced neutrons in LSM in application for direct dark matter searches  

SciTech Connect

Due to a very low event rate expected in direct dark matter search experiments, a good understanding of every background component is crucial. Muon-induced neutrons constitute a prominent background, since neutrons lead to nuclear recoils and thus can mimic a potential dark matter signal. EDELWEISS is a Ge-bolometer experiment searching for WIMP dark matter. It is located in the Laboratoire Souterrain de Modane (LSM, France). We have measured muon-induced neutrons by means of a neutron counter based on Gd-loaded liquid scintillator. Studies of muon-induced neutrons are presented and include development of the appropriate MC model based on Geant4 and analysis of a 1000-days measurement campaign in LSM. We find a good agreement between measured rates of muon-induced neutrons and those predicted by the developed model with full event topology. The impact of the neutron background on current EDELWEISS data-taking as well as for next generation experiments such as EURECA is briefly discussed.

Kozlov, Valentin [Karlsruhe Institute of Technology, Institut fr Kernphysik, Postfach 3640, 76021 Karlsruhe (Germany)] [Karlsruhe Institute of Technology, Institut fr Kernphysik, Postfach 3640, 76021 Karlsruhe (Germany); Collaboration: EDELWEISS Collaboration

2013-08-08

238

Direct constraints on diffusion models from cosmic-ray positron data: Excluding the minimal model for dark matter searches  

NASA Astrophysics Data System (ADS)

Galactic cosmic-ray (CR) transport parameters are usually constrained by the boron-to-carbon ratio. This procedure is generically plagued with degeneracies between the diffusion coefficient and the vertical extent of the Galactic magnetic halo. The latter is of paramount importance for indirect dark matter (DM) searches because it fixes the amount of DM annihilation or decay that contributes to the local antimatter CR flux. These degeneracies could be broken by using secondary radioactive species, but the current data still have large error bars, and this method is extremely sensitive to the very local interstellar medium properties. Here, we propose to use the low-energy CR positrons in the GeV range as another direct constraint on diffusion models. We show that the PAMELA data disfavor small diffusion halo (L?3 kpc) and large diffusion slope models and exclude the minimal configuration [Maurin et al. Astrophys. J. 555, 585 (2001); Donato et al. Phys. Rev. D 69, 063501 (2004)] widely used in the literature to bracket the uncertainties in the DM signal predictions. This is complementary to indirect constraints (diffuse radio and gamma-ray emissions) and has a strong impact on DM searches. Indeed, this makes the antiproton constraints more robust while enhancing the discovery/exclusion potential of current and future experiments, like AMS-02 and GAPS, especially in the antiproton and antideuteron channels.

Lavalle, Julien; Maurin, David; Putze, Antje

2014-10-01

239

Direct constraints on diffusion models from cosmic-ray positron data: Excluding the MIN model for dark matter searches  

E-print Network

Galactic Cosmic-ray (CR) transport parameters are usually constrained by the boron-to-carbon ratio. This procedure is generically plagued with degeneracies between the diffusion coefficient and the vertical extent of the Galactic magnetic halo. The latter is of paramount importance for indirect dark matter (DM) searches, because it fixes the amount of DM annihilation or decay that contributes to the local antimatter CR flux. These degeneracies could be broken by using secondary radioactive species, but the current data still have large error bars, and this method is extremely sensitive to the very local interstellar medium (ISM) properties. Here, we propose to use the low-energy CR positrons in the GeV range as another direct constraint on diffusion models. We show that the PAMELA data disfavor small diffusion halo ($L\\lesssim 3$ kpc) and large diffusion slope models, and exclude the minimal ({\\em min}) configuration (Maurin et al. 2001, Donato et al. 2004) widely used in the literature to bracket the uncertainties in the DM signal predictions. This is complementary to indirect constraints (diffuse radio and gamma-ray emissions) and has strong impact on DM searches. Indeed this makes the antiproton constraints more robust while enhancing the discovery/exclusion potential of current and future experiments, like AMS-02 and GAPS, especially in the antiproton and antideuteron channels.

Julien Lavalle; David Maurin; Antje Putze

2014-07-09

240

Duplex interrogation by a direct DNA repair protein in search of base damage  

SciTech Connect

ALKBH2 is a direct DNA repair dioxygenase guarding the mammalian genome against N{sup 1}-methyladenine, N{sup 3}-methylcytosine and 1,N{sup 6}-ethenoadenine damage. A prerequisite for repair is to identify these lesions in the genome. Here we present crystal structures of human ALKBH2 bound to different duplex DNAs. Together with computational and biochemical analyses, our results suggest that DNA interrogation by ALKBH2 has two previously unknown features: (i) ALKBH2 probes base-pair stability and detects base pairs with reduced stability, and (ii) ALKBH2 does not have nor need a damage-checking site, which is critical for preventing spurious base cleavage for several glycosylases. The demethylation mechanism of ALKBH2 insures that only cognate lesions are oxidized and reversed to normal bases, and that a flipped, non-substrate base remains intact in the active site. Overall, the combination of duplex interrogation and oxidation chemistry allows ALKBH2 to detect and process diverse lesions efficiently and correctly.

Yi, Chengqi; Chen, Baoen; Qi, Bo; Zhang, Wen; Jia, Guifang; Zhang, Liang; Li, Charles J.; Dinner, Aaron R.; Yang, Cai-Guang; He, Chuan (Peking); (Chinese Aca. Sci.); (UC)

2012-08-31

241

Making sense of the local Galactic escape speed estimates in direct dark matter searches  

E-print Network

Direct detection (DD) of dark matter (DM) candidates in the $\\lesssim$10 GeV mass range is very sensitive to the tail of their velocity distribution. The important quantity is the maximum WIMP speed in the observer's rest frame, i.e. in average the sum of the local Galactic escape speed $v_{\\rm esc}$ and of the circular velocity of the Sun $v_c$. While the latter has been receiving continuous attention, the former is more difficult to constrain. The RAVE Collaboration has just released a new estimate of $v_{\\rm esc}$ (Piffl {\\em et al.}, 2014 --- P14) that supersedes the previous one (Smith {\\em et al.}, 2007), which is of interest in the perspective of reducing the astrophysical uncertainties in DD. Nevertheless, these new estimates cannot be used blindly as they rely on assumptions in the dark halo modeling which induce tight correlations between the escape speed and other local astrophysical parameters. We make a self-consistent study of the implications of the RAVE results on DD assuming isotropic DM velo...

Lavalle, Julien

2014-01-01

242

Testing the Zee-Babu model via neutrino data, lepton flavour violation and direct searches at the LHC  

E-print Network

We discuss how the Zee-Babu model can be tested combining information from neutrino data, low-energy experiments and direct searches at the LHC. We update previous analysis in the light of the recent measurement of the neutrino mixing angle $\\theta_{13}$, the new MEG limits on $\\mu \\rightarrow e \\gamma$, the lower bounds on doubly-charged scalars coming from LHC data, and, of course, the discovery of a 125 GeV Higgs boson by ATLAS and CMS. In particular, we find that the new singly- and doubly-charged scalars are accessible at the second run of the LHC, yielding different signatures depending on the neutrino hierarchy and on the values of the phases. We also discuss in detail the stability of the potential.

Herrero-Garcia, Juan; Rius, Nuria; Santamaria, Arcadi

2014-01-01

243

Parallel MATLAB at VT: Parallel For Loops  

E-print Network

.......... FSU: Florida State University AOE: Department of Aerospace and Ocean Engineering ARC: Advanced Research Computing ICAM: Interdisciplinary Center for Applied Mathematics 1 / 56 #12;Matlab Parallel on the order of execution. There are also restrictions on array-data access. OpenMP implements a directive

Crawford, T. Daniel

244

Parallel MATLAB at VT: Parallel For Loops  

E-print Network

.......... FSU: Florida State University AOE: Department of Aerospace and Ocean Engineering ARC: Advanced Research Computing ICAM: Interdisciplinary Center for Applied Mathematics 1 / 71 #12;MATLAB Parallel are completely independent; there are also some restrictions on array-data access. OpenMP implements a directive

Crawford, T. Daniel

245

Parallel MATLAB at VT: Parallel For Loops  

E-print Network

.......... FSU: Florida State University AOE: Department of Aerospace and Ocean Engineering ARC: Advanced Research Computing ICAM: Interdisciplinary Center for Applied Mathematics 1 / 72 #12;MATLAB Parallel independent; there are also some restrictions on array-data access. OpenMP implements a directive

Crawford, T. Daniel

246

Parallel Algorithms  

NSDL National Science Digital Library

Content prepared for the Supercomputing 2002 session on "Using Clustering Technologies in the Classroom". Contains a series of exercises for teaching parallel computing concepts through kinesthetic activities.

Gray, Paul

247

Collective cargo hauling by a bundle of parallel microtubules: bi-directional motion caused by load-dependent polymerization and depolymerization  

E-print Network

A microtubule (MT) is a hollow tube of approximately 25 nm diameter. The two ends of the tube are dissimilar and are designated as `plus' and `minus' ends. Motivated by the collective push and pull exerted by a bundle of MTs during chromosome segregation in a living cell, we have developed here a much simplified theoretical model of a bundle of parallel dynamic MTs. The plus-end of all the MTs in the bundle are permanently attached to a movable `wall' by a device whose detailed structure is not treated explicitly in our model. The only requirement is that the device allows polymerization and depolymerization of each MT at the plus-end. In spite of the absence of external force and direct lateral interactions between the MTs, the group of polymerizing MTs attached to the wall create a load force against the group of depolymerizing MTs and vice-versa; the load against a group is shared equally by the members of that group. Such indirect interactions among the MTs gives rise to the rich variety of possible state...

Ghanti, Dipanwita

2014-01-01

248

Parallel Optimisation  

NSDL National Science Digital Library

An introduction to optimisation techniques that may improve parallel performance and scaling on HECToR. It assumes that the reader has some experience of parallel programming including basic MPI and OpenMP. Scaling is a measurement of the ability for a parallel code to use increasing numbers of cores efficiently. A scalable application is one that, when the number of processors is increased, performs better by a factor which justifies the additional resource employed. Making a parallel application scale to many thousands of processes requires not only careful attention to the communication, data and work distribution but also to the choice of the algorithms to use. Since the choice of algorithm is too broad a subject and very particular to application domain to include in this brief guide we concentrate on general good practices towards parallel optimisation on HECToR.

249

((((((((((((((((((((((((((Understanding student) identity) from) a) socialization) perspective.) In) Hanson ) C.) Ed.) New) Directions) in) Student) Development ) In) search) of) self:) Exploring) undergraduate) identity) development.) San) Francisco:) Jossey-Bass.)  

EPA Pesticide Factsheets

Search instead for ((((((((((((((((((((((((((Understanding student) identity) from) a) socialization) perspective.) In) Hanson ) C.) Ed.) New) Directions) in) Student) Development ) In) search) of) self:) Exploring) undergraduate) identity) development.) San) Francisco:) Jossey-Bass.) ?

250

((((((((((((((((((((((((((Understanding student) identity) from) a) socialization) perspective.) In) Hanson ) C.) Ed.) New) Directions) in) Student) Development ) In) search) of) self:) Exploring) undergraduate) identity) development.) San) Francisco:) Josey-Bass.)  

EPA Pesticide Factsheets

Search instead for ((((((((((((((((((((((((((Understanding student) identity) from) a) socialization) perspective.) In) Hanson ) C.) Ed.) New) Directions) in) Student) Development ) In) search) of) self:) Exploring) undergraduate) identity) development.) San) Francisco:) Josey-Bass.) ?

251

A search for anisotropy in the arrival directions of ultra high energy cosmic rays recorded at the Pierre Auger Observatory  

SciTech Connect

Observations of cosmic ray arrival directions made with the Pierre Auger Observatory have previously provided evidence of anisotropy at the 99% CL using the correlation of ultra high energy cosmic rays (UHECRs) with objects drawn from the Vron-Cetty Vron catalog. In this paper we report on the use of three catalog independent methods to search for anisotropy. The 2ptL, 2pt+ and 3pt methods, each giving a different measure of self-clustering in arrival directions, were tested on mock cosmic ray data sets to study the impacts of sample size and magnetic smearing on their results, accounting for both angular and energy resolutions. If the sources of UHECRs follow the same large scale structure as ordinary galaxies in the local Universe and if UHECRs are deflected no more than a few degrees, a study of mock maps suggests that these three methods can efficiently respond to the resulting anisotropy with a P-value = 1.0% or smaller with data sets as few as 100 events. Using data taken from January 1, 2004 to July 31, 2010 we examined the 20,30,...,110 highest energy events with a corresponding minimum energy threshold of about 49.3 EeV. The minimum P-values found were 13.5% using the 2pt-L method, 1.0% using the 2pt+ method and 1.1% using the 3pt method for the highest 100 energy events. In view of the multiple (correlated) scans performed on the data set, these catalog-independent methods do not yield strong evidence of anisotropy in the highest energy cosmic rays.

Abreu, P.; Andringa, S. [LIP and Instituto Superior Tcnico, Technical University of Lisbon (Portugal); Aglietta, M. [Istituto di Fisica dello Spazio Interplanetario (INAF), Universit di Torino and Sezione INFN, Torino (Italy); Ahlers, M. [University of Wisconsin, Madison, WI (United States); Ahn, E.J. [Fermilab, Batavia, IL (United States); Albuquerque, I.F.M. [Universidade de So Paulo, Instituto de Fsica, So Paulo, SP (Brazil); Allard, D. [Laboratoire AstroParticule et Cosmologie (APC), Universit Paris 7, CNRS-IN2P3, Paris (France); Allekotte, I. [Centro Atmico Bariloche and Instituto Balseiro (CNEA-UNCuyo-CONICET), San Carlos de Bariloche (Argentina); Allen, J. [New York University, New York, NY (United States); Allison, P. [Ohio State University, Columbus, OH (United States); Almela, A. [Universidad Tecnolgica Nacional - Facultad Regional Buenos Aires, Buenos Aires (Argentina); Castillo, J. Alvarez [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico); Alvarez-Muiz, J. [Universidad de Santiago de Compostela (Spain); Ambrosio, M.; Aramo, C. [Universit di Napoli 'Federico II' and Sezione INFN, Napoli (Italy); Aminaei, A. [IMAPP, Radboud University Nijmegen (Netherlands); Anchordoqui, L. [University of Wisconsin, Milwaukee, WI (United States); Antici'c, T. [Rudjer Bokovi'c Institute, 10000 Zagreb (Croatia); Arganda, E. [IFLP, Universidad Nacional de La Plata and CONICET, La Plata (Argentina); Arqueros, F., E-mail: auger_spokesperson@fnal.gov [Universidad Complutense de Madrid, Madrid (Spain); Collaboration: Pierre Auger Collaboration; and others

2012-04-01

252

A search for anisotropy in the arrival directions of ultra high energy cosmic rays recorded at the Pierre Auger Observatory  

NASA Astrophysics Data System (ADS)

Observations of cosmic ray arrival directions made with the Pierre Auger Observatory have previously provided evidence of anisotropy at the 99% CL using the correlation of ultra high energy cosmic rays (UHECRs) with objects drawn from the Vron-Cetty Vron catalog. In this paper we report on the use of three catalog independent methods to search for anisotropy. The 2pt-L, 2pt+ and 3pt methods, each giving a different measure of self-clustering in arrival directions, were tested on mock cosmic ray data sets to study the impacts of sample size and magnetic smearing on their results, accounting for both angular and energy resolutions. If the sources of UHECRs follow the same large scale structure as ordinary galaxies in the local Universe and if UHECRs are deflected no more than a few degrees, a study of mock maps suggests that these three methods can efficiently respond to the resulting anisotropy with a P-value = 1.0% or smaller with data sets as few as 100 events. Using data taken from January 1, 2004 to July 31, 2010 we examined the 20,30,...,110 highest energy events with a corresponding minimum energy threshold of about 49.3 EeV. The minimum P-values found were 13.5% using the 2pt-L method, 1.0% using the 2pt+ method and 1.1% using the 3pt method for the highest 100 energy events. In view of the multiple (correlated) scans performed on the data set, these catalog-independent methods do not yield strong evidence of anisotropy in the highest energy cosmic rays.

Pierre Auger Collaboration; Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muiz, J.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Antici'c, T.; Aramo, C.; Arganda, E.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Bcker, T.; Badescu, A. M.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Barroso, S. L. C.; Baughman, B.; Buml, J.; Beatty, J. J.; Becker, B. R.; Becker, K. H.; Belltoile, A.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blmer, H.; Bohcov, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Burton, R. E.; Caballero-Mora, K. S.; Caccianiga, B.; Caramete, L.; Caruso, R.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chirinos Diaz, J.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Coluccia, M. R.; Conceio, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coppens, J.; Cordier, A.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Dallier, R.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; De Donato, C.; de Jong, S. J.; De La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; del Peral, L.; del Ro, M.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Daz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Fajardo Tapia, I.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Filevich, A.; Filipcic, A.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Fratu, O.; Frhlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; Garca, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Gascon, A.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giller, M.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gmez Berisso, M.; Gmez Vitale, P. F.; Gonalves, P.; Gonzalez, D.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gouffon, P.; Grashorn, E.; Grebe, S.; Griffith, N.; Grigat, M.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Guzman, A.; Hague, J. D.; Hansen, P.; Harari, D.; Harmsma, S.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Hrandel, J. R.; Horneffer, A.; Horvath, P.; Hrabovsk, M.; Huege, T.; Insolia, A.; Ionita, F.; Italiano, A.; Jarne, C.; Jiraskova, S.; Josebachuili, M.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Kgl, B.; Keilhauer, B.; Keivani, A.; Kelley, J. L.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Koang, D.-H.; Kotera, K.; Krohm, N.; Krmer, O.; Kruppke-Hansen, D.; Kuehn, F.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; Lachaud, C.; Lauer, R.; Lautridou, P.; Le Coz, S.; Leo, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lpez, R.; Lopez Agera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Macolino, C.; Maldera, S.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, J.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martnez Bravo, O.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Mertsch, P.; Meurer, C.; Mi'canovi'c, S.; Micheletti, M. I.; Minaya, I. A.; Miramonti, L.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Mostaf, M.; Moura, C. A.; Muller, M. A.; Mller, G.; Mnchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nhung, P. T.; Niechciol, M.; Niemietz, L.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Noka, L.; Nyklicek, M.; Oehlschlger, J.; Olinto, A.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrinca, P.; Petrolini, A.; Petrov, Y.

2012-04-01

253

Process Simulation and Control Optimization of a Blast Furnace Using Classical Thermodynamics Combined to a Direct Search Algorithm  

NASA Astrophysics Data System (ADS)

Several numerical approaches have been proposed in the literature to simulate the behavior of modern blast furnaces: finite volume methods, data-mining models, heat and mass balance models, and classical thermodynamic simulations. Despite this, there is actually no efficient method for evaluating quickly optimal operating parameters of a blast furnace as a function of the iron ore composition, which takes into account all potential chemical reactions that could occur in the system. In the current study, we propose a global simulation strategy of a blast furnace, the 5-unit process simulation. It is based on classical thermodynamic calculations coupled to a direct search algorithm to optimize process parameters. These parameters include the minimum required metallurgical coke consumption as well as the optimal blast chemical composition and the total charge that simultaneously satisfy the overall heat and mass balances of the system. Moreover, a Gibbs free energy function for metallurgical coke is parameterized in the current study and used to fine-tune the simulation of the blast furnace. Optimal operating conditions and predicted output stream properties calculated by the proposed thermodynamic simulation strategy are compared with reference data found in the literature and have proven the validity and high precision of this simulation.

Harvey, Jean-Philippe; Gheribi, Amen E.

2013-12-01

254

Impact of Coherent Neutrino Nucleus Scattering on Direct Dark Matter Searches based on CaWO$_4$ Crystals  

E-print Network

Atmospheric and solar neutrinos scattering coherently off target nuclei could be a serious background source for the next generation of direct dark matter searches. We present our studies on the maximal sensitivity on the elastic spin-independent WIMP-nucleon cross section which can be achieved by a background-free experiment based on calcium tungstate as target material. An experiment achieves this maximal sensitivity when one neutrino event is expected for the experiment's energy threshold and exposure. Thus, a first detection of coherent neutrino nucleus scattering (CNNS) could also be in reach of such an experiment, if neutron-like backgrounds are small enough ($\\lesssim 0.1$ events for the respective exposures). Due to the small energies of solar neutrinos, calcium tungstate with its light nuclei oxygen and calcium seems to be well suited for a detection of CNNS. We show that for a counting experiment using only the integral above an energy threshold as well as a Bayesian analysis taking into account spe...

Gtlein, A; Bento, A; Bucci, C; Canonica, L; Erb, A; Feilitzsch, F v; Iachellini, N Ferreiro; Gorla, P; Hauff, D; Jochum, J; Kiefer, M; Kluck, H; Kraus, H; Lanfranchi, J -C; Loebell, J; Mnster, A; Petricca, F; Potzel, W; Prbst, F; Reindl, F; Roth, S; Rottler, K; Sailer, C; Schffner, K; Schieck, J; Schnert, S; Seidel, W; Sivers, M v; Stodolsky, L; Strandhagen, C; Strauss, R; Tanzke, A; Uffinger, M; Ulrich, A; Usherov, I; Wawoczny, S; Willers, M; Wstrich, M; Zller, A

2014-01-01

255

Impact of Coherent Neutrino Nucleus Scattering on Direct Dark Matter Searches based on CaWO$_4$ Crystals  

E-print Network

Atmospheric and solar neutrinos scattering coherently off target nuclei could be a serious background source for the next generation of direct dark matter searches. We present our studies on the maximal sensitivity on the elastic spin-independent WIMP-nucleon cross section which can be achieved by a background-free experiment based on calcium tungstate as target material. An experiment achieves this maximal sensitivity when one neutrino event is expected for the experiment's energy threshold and exposure. Thus, a first detection of coherent neutrino nucleus scattering (CNNS) could also be in reach of such an experiment, if neutron-like backgrounds are small enough ($\\lesssim 0.1$ events for the respective exposures). Due to the small energies of solar neutrinos, calcium tungstate with its light nuclei oxygen and calcium seems to be well suited for a detection of CNNS. We show that for a counting experiment using only the integral above an energy threshold as well as a Bayesian analysis taking into account spectral shapes a detection of CNNS on a 3$\\sigma$ confidence level is possible for exposures between 50 and 300 kg-years.

A. Gtlein; G. Angloher; A. Bento; C. Bucci; L. Canonica; A. Erb; F. v. Feilitzsch; N. Ferreiro Iachellini; P. Gorla; D. Hauff; J. Jochum; M. Kiefer; H. Kluck; H. Kraus; J. -C. Lanfranchi; J. Loebell; A. Mnster; F. Petricca; W. Potzel; F. Prbst; F. Reindl; S. Roth; K. Rottler; C. Sailer; K. Schffner; J. Schieck; S. Schnert; W. Seidel; M. v. Sivers; L. Stodolsky; C. Strandhagen; R. Strauss; A. Tanzke; M. Uffinger; A. Ulrich; I. Usherov; S. Wawoczny; M. Willers; M. Wstrich; A. Zller

2014-08-11

256

Direct constraints on diffusion models from cosmic-ray positron data: Excluding the MIN model for dark matter searches  

E-print Network

Galactic Cosmic-ray (CR) transport parameters are usually constrained by the boron-to-carbon ratio. This procedure is generically plagued with degeneracies between the diffusion coefficient and the vertical extent of the Galactic magnetic halo. The latter is of paramount importance for indirect dark matter (DM) searches, because it fixes the amount of DM annihilation or decay that contributes to the local antimatter CR flux. These degeneracies could be broken by using secondary radioactive species, but the current data still have large error bars, and this method is extremely sensitive to the very local interstellar medium (ISM) properties. Here, we propose to use the low-energy CR positrons in the GeV range as another direct constraint on diffusion models. We show that the PAMELA data disfavor small diffusion halo ($L\\lesssim 3$ kpc) and large diffusion slope models, and exclude the minimal ({\\em min}) configuration (Maurin et al. 2001, Donato et al. 2004) widely used in the literature to bracket the uncerta...

Lavalle, Julien; Putze, Antje

2014-01-01

257

Parallel biocomputing  

PubMed Central

Background With the advent of high throughput genomics and high-resolution imaging techniques, there is a growing necessity in biology and medicine for parallel computing, and with the low cost of computing, it is now cost-effective for even small labs or individuals to build their own personal computation cluster. Methods Here we briefly describe how to use commodity hardware to build a low-cost, high-performance compute cluster, and provide an in-depth example and sample code for parallel execution of R jobs using MOSIX, a mature extension of the Linux kernel for parallel computing. A similar process can be used with other cluster platform software. Results As a statistical genetics example, we use our cluster to run a simulated eQTL experiment. Because eQTL is computationally intensive, and is conceptually easy to parallelize, like many statistics/genetics applications, parallel execution with MOSIX gives a linear speedup in analysis time with little additional effort. Conclusions We have used MOSIX to run a wide variety of software programs in parallel with good results. The limitations and benefits of using MOSIX are discussed and compared to other platforms. PMID:21418580

2011-01-01

258

Universal approximators for multi-objective direct policy search in water reservoir management problems: a comparative analysis  

NASA Astrophysics Data System (ADS)

The optimal operation of water resources systems is a wide and challenging problem due to non-linearities in the model and the objectives, high dimensional state-control space, and strong uncertainties in the hydroclimatic regimes. The application of classical optimization techniques (e.g., SDP, Q-learning, gradient descent-based algorithms) is strongly limited by the dimensionality of the system and by the presence of multiple, conflicting objectives. This study presents a novel approach which combines Direct Policy Search (DPS) and Multi-Objective Evolutionary Algorithms (MOEAs) to solve high-dimensional state and control space problems involving multiple objectives. DPS, also known as parameterization-simulation-optimization in the water resources literature, is a simulation-based approach where the reservoir operating policy is first parameterized within a given family of functions and, then, the parameters optimized with respect to the objectives of the management problem. The selection of a suitable class of functions to which the operating policy belong to is a key step, as it might restrict the search for the optimal policy to a subspace of the decision space that does not include the optimal solution. In the water reservoir literature, a number of classes have been proposed. However, many of these rules are based largely on empirical or experimental successes and they were designed mostly via simulation and for single-purpose reservoirs. In a multi-objective context similar rules can not easily inferred from the experience and the use of universal function approximators is generally preferred. In this work, we comparatively analyze two among the most common universal approximators: artificial neural networks (ANN) and radial basis functions (RBF) under different problem settings to estimate their scalability and flexibility in dealing with more and more complex problems. The multi-purpose HoaBinh water reservoir in Vietnam, accounting for hydropower production and flood control, is used as a case study. Preliminary results show that the RBF policy parametrization is more effective than the ANN one. In particular, the approximated Pareto front obtained with RBF control policies successfully explores the full tradeoff space between the two conflicting objectives, while most of the ANN solutions results to be Pareto-dominated by the RBF ones.

Giuliani, Matteo; Mason, Emanuele; Castelletti, Andrea; Pianosi, Francesca

2014-05-01

259

Automatic Multilevel Parallelization Using OpenMP  

NASA Technical Reports Server (NTRS)

In this paper we describe the extension of the CAPO (CAPtools (Computer Aided Parallelization Toolkit) OpenMP) parallelization support tool to support multilevel parallelism based on OpenMP directives. CAPO generates OpenMP directives with extensions supported by the NanosCompiler to allow for directive nesting and definition of thread groups. We report some results for several benchmark codes and one full application that have been parallelized using our system.

Jin, Hao-Qiang; Jost, Gabriele; Yan, Jerry; Ayguade, Eduard; Gonzalez, Marc; Martorell, Xavier; Biegel, Bryan (Technical Monitor)

2002-01-01

260

The application of the Luus-Jaakola direct search method to the optimization of a hybrid renewable energy system  

NASA Astrophysics Data System (ADS)

The application of the Luus-Jaakola direct search method to the optimization of stand-alone hybrid energy systems consisting of wind turbine generators (WTG's), photovoltaic (PV) modules, batteries, and an auxiliary generator was examined. The loads for these systems were for agricultural applications, with the optimization conducted on the basis of minimum capital, operating, and maintenance costs. Five systems were considered: two near Edmonton, Alberta, and one each near Lethbridge, Alberta, Victoria, British Columbia, and Delta, British Columbia. The optimization algorithm used hourly data for the load demand, WTG output power/area, and PV module output power. These hourly data were in two sets: seasonal (summer and winter values separated) and total (summer and winter values combined). The costs for the WTG's, PV modules, batteries, and auxiliary generator fuel were full market values. To examine the effects of price discounts or tax incentives, these values were lowered to 25% of the full costs for the energy sources and two-thirds of the full cost for agricultural fuel. Annual costs for a renewable energy system depended upon the load, location, component costs, and which data set (seasonal or total) was used. For one Edmonton load, the cost for a renewable energy system consisting of 27.01 m2 of WTG area, 14 PV modules, and 18 batteries (full price, total data set) was 6873/year. For Lethbridge, a system with 22.85 m2 of WTG area, 47 PV modules, and 5 batteries (reduced prices, seasonal data set) cost 2913/year. The performance of renewable energy systems based on the obtained results was tested in a simulation using load and weather data for selected days. Test results for one Edmonton load showed that the simulations for most of the systems examined ran for at least 17 hours per day before failing due to either an excessive load on the auxiliary generator or a battery constraint being violated. Additional testing indicated that increasing the generator capacity and reducing the maximum allowed battery charge current during the time of the day at which these failures occurred allowed the simulation to successfully operate.

Jatzeck, Bernhard Michael

2000-10-01

261

Applied Parallel Metadata Indexing  

SciTech Connect

The GPFS Archive is parallel archive is a parallel archive used by hundreds of users in the Turquoise collaboration network. It houses 4+ petabytes of data in more than 170 million files. Currently, users must navigate the file system to retrieve their data, requiring them to remember file paths and names. A better solution might allow users to tag data with meaningful labels and searach the archive using standard and user-defined metadata, while maintaining security. last summer, I developed the backend to a tool that adheres to these design goals. The backend works by importing GPFS metadata into a MongoDB cluster, which is then indexed on each attribute. This summer, the author implemented security and developed the user interfae for the search tool. To meet security requirements, each database table is associated with a single user, which only stores records that the user may read, and requires a set of credentials to access. The interface to the search tool is implemented using FUSE (Filesystem in USErspace). FUSE is an intermediate layer that intercepts file system calls and allows the developer to redefine how those calls behave. In the case of this tool, FUSE interfaces with MongoDB to issue queries and populate output. A FUSE implementation is desirable because it allows users to interact with the search tool using commands they are already familiar with. These security and interface additions are essential for a usable product.

Jacobi, Michael R [Los Alamos National Laboratory

2012-08-01

262

Demonstrating Forces between Parallel Wires.  

ERIC Educational Resources Information Center

Describes a physics demonstration that dramatically illustrates the mutual repulsion (attraction) between parallel conductors using insulated copper wire, wooden dowels, a high direct current power supply, electrical tape, and an overhead projector. (WRM)

Baker, Blane

2000-01-01

263

Scalable Parallel Crash Simulations  

SciTech Connect

We are pleased to submit our efforts in parallelizing the PRONTO application suite for con- sideration in the SuParCup 99 competition. PRONTO is a finite element transient dynamics simulator which includes a smoothed particle hydrodynamics (SPH) capability; it is similar in scope to the well-known DYNA, PamCrash, and ABAQUS codes. Our efforts over the last few years have produced a fully parallel version of the entire PRONTO code which (1) runs fast and scalably on thousands of processors, (2) has performed the largest finite-element transient dynamics simulations we are aware of, and (3) includes several new parallel algorithmic ideas that have solved some difficult problems associated with contact detection and SPH scalability. We motivate this work, describe the novel algorithmic advances, give performance numbers for PRONTO running on Sandia's Intel Teraflop machine, and highlight two prototypical large-scale computations we have performed with the parallel code. We have successfully parallelized a large-scale production transient dynamics code with a novel algorithmic approach that utilizes multiple decompositions for different key segments of the computations. To be able to simulate a more than ten million element model in a few tenths of second per timestep is unprecedented for solid dynamics simulations, especially when full global contact searches are required. The key reason is our new algorithmic ideas for efficiently parallelizing the contact detection stage. To our knowledge scalability of this computation had never before been demonstrated on more than 64 processors. This has enabled parallel PRONTO to become the only solid dynamics code we are aware of that can run effectively on 1000s of processors. More importantly, our parallel performance compares very favorably to the original serial PRONTO code which is optimized for vector supercomputers. On the container crush problem, a Teraflop node is as fast as a single processor of the Cray Jedi. This means that on the Teraflop machine we can now run simulations with tens of millions of elements thousands of times faster than we could on the Jedi! This is enabling transient dynamics simulations of unprecedented scale and fidelity. Not only can previous applications be run with vastly improved resolution and speed, but qualitatively new and different analyses have been made possible.

Attaway, Stephen; Barragy, Ted; Brown, Kevin; Gardner, David; Gruda, Jeff; Heinstein, Martin; Hendrickson, Bruce; Metzinger, Kurt; Neilsen, Mike; Plimpton, Steve; Pott, John; Swegle, Jeff; Vaughan, Courtenay

1999-06-01

264

Discovering Common Ground: How Future Search Conferences Bring People Together To Achieve Breakthrough Innovation, Empowerment, Shared Vision, and Collaborative Action.  

ERIC Educational Resources Information Center

This book contains 35 papers about planning and holding future search conferences, as well as their benefits and likely future directions. The following papers are included: "Applied Common Sense" (Weisbord); "Inventing the Search Conference" (Weisbord); "Building Collaborative Communities" (Schindler-Rainman, Lippitt); "Parallel Paths to

Weisbord, Marvin R.; And Others

265

Parallel hierarchical global illumination  

SciTech Connect

Solving the global illumination problem is equivalent to determining the intensity of every wavelength of light in all directions at every point in a given scene. The complexity of the problem has led researchers to use approximation methods for solving the problem on serial computers. Rather than using an approximation method, such as backward ray tracing or radiosity, the authors have chosen to solve the Rendering Equation by direct simulation of light transport from the light sources. This paper presents an algorithm that solves the Rendering Equation to any desired accuracy, and can be run in parallel on distributed memory or shared memory computer systems with excellent scaling properties. It appears superior in both speed and physical correctness to recent published methods involving bidirectional ray tracing or hybrid treatments of diffuse and specular surfaces. Like progressive radiosity methods, it dynamically refines the geometry decomposition where required, but does so without the excessive storage requirements for ray histories. The algorithm, called Photon, produces a scene which converges to the global illumination solution. This amounts to a huge task for a 1997-vintage serial computer, but using the power of a parallel supercomputer significantly reduces the time required to generate a solution. Currently, Photon can be run on most parallel environments from a shared memory multiprocessor to a parallel supercomputer, as well as on clusters of heterogeneous workstations.

Snell, Q.O.

1997-10-08

266

Parallel Processing and Information Retrieval.  

ERIC Educational Resources Information Center

This issue contains nine articles that provide an overview of trends and research in parallel information retrieval. Topics discussed include network design for text searching; the Connection Machine System; PThomas, an adaptive information retrieval system on the Connection Machine; algorithms for document clustering; and system architecture for

Rasmussen, Edie M.; And Others

1991-01-01

267

Parallel Anisotropic Tetrahedral Adaptation  

NASA Technical Reports Server (NTRS)

An adaptive method that robustly produces high aspect ratio tetrahedra to a general 3D metric specification without introducing hybrid semi-structured regions is presented. The elemental operators and higher-level logic is described with their respective domain-decomposed parallelizations. An anisotropic tetrahedral grid adaptation scheme is demonstrated for 1000-1 stretching for a simple cube geometry. This form of adaptation is applicable to more complex domain boundaries via a cut-cell approach as demonstrated by a parallel 3D supersonic simulation of a complex fighter aircraft. To avoid the assumptions and approximations required to form a metric to specify adaptation, an approach is introduced that directly evaluates interpolation error. The grid is adapted to reduce and equidistribute this interpolation error calculation without the use of an intervening anisotropic metric. Direct interpolation error adaptation is illustrated for 1D and 3D domains.

Park, Michael A.; Darmofal, David L.

2008-01-01

268

Parallel Algorithms for Big Data Optimization  

E-print Network

Index TermsParallel optimization, Distributed methods, Ja- cobi method ... Usually the nonsmooth term is used to ..... dard Armijo-like line-search procedure or a (suitably small) constant ..... enter the identification phase xk i is not zero, the

2014-02-21

269

Automatic Multilevel Parallelization Using OpenMP  

NASA Technical Reports Server (NTRS)

In this paper we describe the extension of the CAPO parallelization support tool to support multilevel parallelism based on OpenMP directives. CAPO generates OpenMP directives with extensions supported by the NanosCompiler to allow for directive nesting and definition of thread groups. We report first results for several benchmark codes and one full application that have been parallelized using our system.

Jin, Hao-Qiang; Jost, Gabriele; Yan, Jerry; Ayguade, Eduard; Gonzalez, Marc; Martorell, Xavier; Biegel, Bryan (Technical Monitor)

2002-01-01

270

Direct search for Dirac magnetic monopoles in pp collisions at square root s = 1.96 TeV.  

PubMed

We search for pair-produced Dirac magnetic monopoles in 35.7 pb(-1) of proton-antiproton collisions at square root s = 1.96 TeV with the Collider Detector at Fermilab (CDF). We find no monopole candidates corresponding to a 95% confidence-level cross-section limit sigma < 0.2 pb for a monopole with mass between 200 and 700 GeV/c2. Assuming a Drell-Yan pair-production mechanism, we set a mass limit m > 360 GeV/c2. PMID:16803165

Abulencia, A; Acosta, D; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arguin, J-F; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Bachacou, H; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Belloni, A; Ben-Haim, E; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bishai, M; Blair, R E; Blocker, C; Bloom, K; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Bourov, S; Boveia, A; Brau, B; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carron, S; Carter, A; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chapman, J; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Chu, P H; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciljak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Connolly, A; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Cruz, A; Cuevas, J; Culbertson, R; Cyr, D; DaRonco, S; D'Auria, S; D'Onofrio, M; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; Dell'Orso, M; Demers, S; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Dionisi, C; Dittmann, J; DiTuro, P; Drr, C; Dominguez, A; Donati, S; Donega, M; Dong, P; Donini, J; Dorigo, T; Dube, S; Ebina, K; Efron, J; Ehlers, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Flores-Castillo, L R; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Fujii, Y; Furic, I; Gajjar, A; Gallinaro, M; Galyardt, J; Garcia, J E; Garcia Sciverez, M; Garfinkel, A F; Gay, C; Gerberich, H; Gerchtein, E; Gerdes, D; Giagu, S; Giannetti, P; Gibson, A; Gibson, K; Ginsburg, C; Giolo, K; Giordani, M; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Gomez, G; Gomez-Ceballos, G; Goncharov, M; Gonzlez, O; Gorelov, I; Goshaw, A T; Gotra, Y; Goulianos, K; Gresele, A; Griffiths, M; Grinstein, S; Grosso-Pilcher, C; Grundler, U; da Costa, J Guimaraes; Haber, C; Hahn, S R; Hahn, K; Halkiadakis, E; Hamilton, A; Han, B-Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harper, S; Harr, R F; Harris, R M; Hatakeyama, K; Hauser, J; Hays, C; Hayward, H; Heijboer, A; Heinemann, B; Heinrich, J; Hennecke, M; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Huston, J; Ikado, K; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jensen, H; Jeon, E J; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kamon, T; Kang, J; Karagoz-Unel, M; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, M S; Kim, S B; Kim, S H; Kim, Y K; Kirby, M; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kobayashi, H; Kondo, K; Kong, D J; Konigsberg, J; Kordas, K; Korytov, A; Kotwal, A V; Kovalev, A; Kraus, J; Kravchenko, I; Kreps, M; Kreymer, A; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kuhlmann, S E; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecci, C; LeCompte, T; Lee, J; Lee, J; Lee, S W; Lefvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Li, K; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Liss, T M; Lister, A; Litvintsev, D O; Liu, T; Liu, Y; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Maksimovic, P; Manca, G; Margaroli, F; Marginean, R; Marino, C; Martin, A; Martin, M; Martin, V; Martnez, M; Maruyama, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McGivern, D; McIntyre, P; McNamara, P; McNulty, R; Mehta, A; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; von der Mey, M; Miao, T; Miladinovic, N; Miles, J; Miller, R; Miller, J S; Mills, C; Milnik, M; Miquel, R; Miscetti, S; Mitselmakher, G; Miyamoto, A; Moggi, N; Mohr, B; Moore, R; Morello, M; Fernandez, P Movilla; Mlmenstdt, J; Mukherjee, A; Mulhearn, M; Muller, Th; Mumford, R; Murat, P; Nachtman, J; Nahn, S; Nakano, I; Napier, A; Naumov, D; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nigmanov, T; Nodulman, L; Norniella, O

2006-05-26

271

First measurement of the headtail directional nuclear recoil signature at energies relevant to WIMP dark matter searches  

Microsoft Academic Search

We present first evidence for the so-called headtail directional signature of neutron-induced nuclear recoil tracks at energies down to 1.5keV\\/amu using the DRIFT-IIc dark matter detector. This regime is appropriate for recoils induced by Weakly Interacting Massive Particle (WIMPs) but one where the differential ionization is poorly understood. We show that the distribution of recoil energies and directions induced here

S. Burgos; E. Daw; J. Forbes; C. Ghag; M. Gold; C. Hagemann; V. A. Kudryavtsev; T. B. Lawson; D. Loomba; P. Majewski; D. Muna; A. St J. Murphy; G. G. Nicklin; S. M. Paling; A. Petkov; S. J. S. Plank; M. Robinson; N. Sanghi; D. P. Snowden-Ifft; N. J. C. Spooner; J. Turk; E. Tziaferi

2009-01-01

272

Parallel Computing Explained  

NSDL National Science Digital Library

Several tutorials on parallel computing. Overview of parallel computing. Porting and code parallelization. Scalar, cache, and parallel code tuning. Timing, profiling and performance analysis. Overview of IBM Regatta P690.

Ncsa

273

Circuit Optimization Using Efficient Parallel Pattern Search  

E-print Network

Circuit optimization is extremely important in order to design today's high performance integrated circuits. As systems become more and more complex, traditional optimization techniques are no longer viable due to the complex and simulation...

Narasimhan, Srinath S.

2011-08-08

274

Parallel Model Refinement of Inductive Applications Using Method Repository  

NASA Astrophysics Data System (ADS)

Here is presented parallel CAMLET that is a platform for automatic composition of inductive applications with method repositories that organize many inductive learning methods. After having implemented CAMLET on a UNIX parallel machine with Perl and C languages, we have done the case studies of constructing inductive applications for eight different data sets from the StatLog repository. To find out an efficient search method, we have done the following experiments: a random search, a GA based search, and two hybrid searches with unifying each global search and the local search which uses meta-rules for refining a specification. That have shown us that the hybrid search works better than the other search methods. Furthermore, comparing the accuracy of inductive applications composed by parallel CMALET with that of popular twenty four inductive algorithms, we have shown that parallel CAMLET support a user in doing model selection in KDD engineering processes.

Abe, Hidenao; Yamaguchi, Takahira

275

First Dark Matter Search Results from a Surface Run of the 10-L DMTPC Directional Dark Matter Detector  

E-print Network

The Dark Matter Time Projection Chamber (DMTPC) is a low pressure (75 Torr CF4) 10 liter detector capable of measuring the vector direction of nuclear recoils with the goal of directional dark matter detection. In this paper we present the first dark matter limit from DMTPC. In an analysis window of 80-200 keV recoil energy, based on a 35.7 g-day exposure, we set a 90% C.L. upper limit on the spin-dependent WIMP-proton cross section of 2.0 x 10^{-33} cm^{2} for 115 GeV/c^2 dark matter particle mass.

S. Ahlen; J. B. R. Battat; T. Caldwell; C. Deaconu; D. Dujmic; W. Fedus; P. Fisher; F. Golub; S. Henderson; A. Inglis; A. Kaboth; G. Kohse; R. Lanza; A. Lee; J. Lopez; J. Monroe; T. Sahin; G. Sciolla; N. Skvorodnev; H. Tomita; H. Wellenstein; I. Wolfe; R. Yamamoto; H. Yegoryan

2010-06-15

276

The StarTech Massively Parallel Chess Program  

Microsoft Academic Search

The StarTech massively parallel chess program, running on a 512-processor Connection Machine CM-5 supercom- puter, tied for third place at the 1993 ACM International Computer Chess Championship. StarTech employs the Jamboree search algorithm, a natural extension of J. Pearl' s Scout search algorithm, to nd parallelism in game-tree searches. StarTech' s w ork-stealing scheduler distributes the work speciedby the search

Bradley C. Kuszmaul

1995-01-01

277

Domain and Data Partitioning for Parallel Mining of Frequent Closed Itemsets  

E-print Network

to partition both the search space and the database for the parallel mining of frequent closed itemsets. The combination of the search space and database partitioning allows parallel processors to mine the frequent an algorithm to partition both the search space and the database for the parallel mining of frequent closed

Tang, Peiyi

278

Domain and Data Partitioning for Parallel Mining of Frequent Closed Itemsets  

E-print Network

to partition both the search space and the database for the parallel mining of frequent closed itemsets. The combination of the search space and database partitioning allows parallel processors to mine the frequent, we propose an algorithm to partition both the search space and the database for the parallel mining

Tang, Peiyi

279

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in = 8 TeV pp collisions with the ATLAS detector  

NASA Astrophysics Data System (ADS)

A search for the direct production of charginos and neutralinos in final states with three leptons and missing transverse momentum is presented. The analysis is based on 20.3 fb-1 of = 8 TeV proton-proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with the Standard Model expectations and limits are set in R-parity-conserving phenomenological Minimal Supersymmetric Standard Models and in simplified supersymmetric models, significantly extending previous results. For simplified supersymmetric models of direct chargino and next-to-lightest neutralino production with decays to lightest neutralino via either all three generations of sleptons, staus only, gauge bosons, or Higgs bosons, and masses are excluded up to 700 GeV, 380 GeV, 345 GeV, or 148 GeV respectively, for a massless . [Figure not available: see fulltext.

Aad, G.; Abajyan, T.; Abbott, B.; Abdallah, J.; Khalek, S. Abdel; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.; Agatonovic-Jovin, T.; Aguilar-Saavedra, J. A.; Agustoni, M.; Ahlen, S. P.; Ahmad, A.; Ahmadov, F.; Aielli, G.; kesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Albert, J.; Albrand, S.; Verzini, M. J. Alconada; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Alimonti, G.; Alio, L.; Alison, J.; Allbrooke, B. M. M.; Allison, L. J.; Allport, P. P.; Allwood-Spiers, S. E.; Almond, J.; Aloisio, A.; Alon, R.; Alonso, A.; Alonso, F.; Alpigiani, C.; Altheimer, A.; Gonzalez, B. Alvarez; Alviggi, M. G.; Amako, K.; Coutinho, Y. Amaral; Amelung, C.; Amidei, D.; Ammosov, V. V.; Santos, S. P. Amor Dos; Amorim, A.; Amoroso, S.; Amram, N.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Anduaga, X. S.; Angelidakis, S.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Bella, L. Aperio; Apolle, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Araque, J. P.; Arce, A. T. H.; Arguin, J.-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Arslan, O.; Artamonov, A.; Artoni, G.; Asai, S.; Asbah, N.; Ashkenazi, A.; Ask, S.; sman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Auerbach, B.; Auge, E.; Augsten, K.; Aurousseau, M.; Avolio, G.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Bacci, C.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Mayes, J. Backus; Badescu, E.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bailey, D. C.; Bain, T.; Baines, J. T.; Baker, O. K.; Baker, S.; Balek, P.; Balli, F.; Banas, E.; Banerjee, Sw.; Banfi, D.; Bangert, A.; Bannoura, A. A. E.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barber, T.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Barnovska, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; da Costa, J. Barreiro Guimares; Bartoldus, R.; Barton, A. E.; Bartos, P.; Bartsch, V.; Bassalat, A.; Basye, A.; Bates, R. L.; Batkova, L.; Batley, J. R.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, S.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Behr, K.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belloni, A.; Beloborodova, O. L.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Noccioli, E. Benhar; Garcia, J. A. Benitez; Benjamin, D. P.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Berge, D.; Kuutmann, E. Bergeaas; Berger, N.; Berghaus, F.; Berglund, E.; Beringer, J.; Bernard, C.; Bernat, P.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertolucci, F.; Besana, M. I.; Besjes, G. J.; Bessidskaia, O.; Besson, N.; Betancourt, C.; Bethke, S.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Bierwagen, K.; Biesiada, J.; Biglietti, M.; De Mendizabal, J. Bilbao; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J.-B.; Blazek, T.; Bloch, I.; Blocker, C.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Boddy, C. R.; Boehler, M.; Boek, J.; Boek, T. T.; Bogaerts, J. A.; Bogdanchikov, A. G.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Boldyrev, A. S.; Bolnet, N. M.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Borri, M.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutouil, S.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozovic-Jelisavcic, I.; Bracinik, J.; Branchini, P.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brelier, B.; Brendlinger, K.; Brennan, A. J.; Brenner, R.; Bressler, S.; Bristow, K.; Bristow, T. M.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Bromberg, C.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Brown, G.; Brown, J.; de Renstrom, P. A. Bruckman; Bruncko, D.; Bruneliere, R.

2014-04-01

280

Search for direct top squark pair production in events with a boson, -jets and missing transverse momentum in TeV collisions with the ATLAS detector  

NASA Astrophysics Data System (ADS)

A search is presented for direct top squark pair production using events with at least two leptons including a same-flavour opposite-sign pair with invariant mass consistent with the boson mass, jets tagged as originating from -quarks and missing transverse momentum. The analysis is performed with proton-proton collision data at collected with the ATLAS detector at the LHC in 2012 corresponding to an integrated luminosity of 20.3 fb. No excess beyond the Standard Model expectation is observed. Interpretations of the results are provided in models based on the direct pair production of the heavier top squark state () followed by the decay to the lighter top squark state () via , and for pair production in natural gauge-mediated supersymmetry breaking scenarios where the neutralino () is the next-to-lightest supersymmetric particle and decays producing a boson and a gravitino () via the process.

Aad, G.; Abbott, B.; Abdallah, J.; Khalek, S. Abdel; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.; Agatonovic-Jovin, T.; Aguilar-Saavedra, J. A.; Agustoni, M.; Ahlen, S. P.; Ahmad, A.; Ahmadov, F.; Aielli, G.; kesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Albrand, S.; Verzini, M. J. Alconada; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Alimonti, G.; Alio, L.; Alison, J.; Allbrooke, B. M. M.; Allison, L. J.; Allport, P. P.; Allwood-Spiers, S. E.; Almond, J.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Altheimer, A.; Alvarez Gonzalez, B.; Alviggi, M. G.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Amidei, D.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amram, N.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Anduaga, X. S.; Angelidakis, S.; Angelozzi, I.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Apolle, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Araque, J. P.; Arce, A. T. H.; Arguin, J.-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Arnold, H.; Arslan, O.; Artamonov, A.; Artoni, G.; Asai, S.; Asbah, N.; Ashkenazi, A.; Ask, S.; sman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Auerbach, B.; Augsten, K.; Aurousseau, M.; Avolio, G.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Bacci, C.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Backus Mayes, J.; Badescu, E.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bain, T.; Baines, J. T.; Baker, O. K.; Baker, S.; Balek, P.; Balli, F.; Banas, E.; Banerjee, Sw.; Banfi, D.; Bangert, A.; Bannoura, A. A. E.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Barnovska, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Guimares da Costa, J. Barreiro; Bartoldus, R.; Barton, A. E.; Bartos, P.; Bartsch, V.; Bassalat, A.; Basye, A.; Bates, R. L.; Batkova, L.; Batley, J. R.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, S.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Behr, K.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belloni, A.; Beloborodova, O. L.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Noccioli, E. Benhar; Garcia, J. A. Benitez; Benjamin, D. P.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Berglund, E.; Beringer, J.; Bernard, C.; Bernat, P.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertolucci, F.; Besana, M. I.; Besjes, G. J.; Bessidskaia, O.; Besson, N.; Betancourt, C.; Bethke, S.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Bierwagen, K.; Biesiada, J.; Biglietti, M.; Bilbao De Mendizabal, J.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J.-B.; Blazek, T.; Bloch, I.; Blocker, C.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Boddy, C. R.; Boehler, M.; Boek, J.; Boek, T. T.; Bogaerts, J. A.; Bogdanchikov, A. G.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Boldyrev, A. S.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Borri, M.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutouil, S.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozovic-Jelisavcic, I.; Bracinik, J.; Branchini, P.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brelier, B.; Brendlinger, K.; Brennan, A. J.; Brenner, R.; Bressler, S.; Bristow, K.; Bristow, T. M.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Bromberg, C.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Brown, G.; Brown, J.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.

2014-06-01

281

Does Foreign Direct Investment Increase the Productivity of Domestic Firms? In Search of Spillovers Through Backward Linkages  

Microsoft Academic Search

Many countries strive to attract foreign direct investment (FDI) hoping that knowledge brought by multinationals will spill over to domestic industries and increase their productivity. In contrast with earlier literature that failed to find positive intraindustry spillovers from FDI, this study focuses on effects operating across industries. The analysis, based on firm-level data from Lithuania, produces evidence consistent with positive

Beata Smarzynska Javorcik

2004-01-01

282

Search for direct top squark pair production in events with a Z boson, b-jets and missing transverse momentum in ?s = 8 TeV pp collisions with the ATLAS detector  

E-print Network

A search is presented for direct top squark pair production using events with at least two leptons including a same-flavour opposite-sign pair with invariant mass consistent with the Z boson mass, jets tagged as originating ...

Taylor, Frank E.

283

Search for Direct Top Squark Pair Production in Final States with One Isolated Lepton, Jets, and Missing Transverse Momentum in ?s=7??TeV pp Collisions Using 4.7??fb[superscript -1] of ATLAS Data  

E-print Network

A search is presented for direct top squark pair production in final states with one isolated electron or muon, jets, and missing transverse momentum in proton-proton collisions at ?s=7??TeV. The measurement is based on ...

Taylor, Frank E.

284

WMAP-normalized inflationary model predictions and the search for primordial gravitational waves with direct detection experiments  

SciTech Connect

In addition to density perturbations, inflationary models of the early Universe generally predict a stochastic background of gravitational waves or tensor fluctuations. By making use of the inflationary flow approach for single field models and fitting the models with Monte Carlo techniques to cosmic microwave background (CMB) data from the Wilkinson Microwave Anisotropy Probe (WMAP), we discuss the expected properties of the gravitational wave background from inflation at scales corresponding to direct detection experiments with laser interferometers in space. We complement the Monte Carlo numerical calculations by including predictions expected under several classes of analytical inflationary models. We find that an improved version of big bang observer (BBO-grand) can be used to detect a gravitational wave background at 0.1 Hz with a corresponding CMB tensor-to-scalar ratio above 10{sup -4}. Even if the CMB tensor-to-scalar ratio were to be above 10{sup -2}, we suggest that BBO-grand will be useful to study inflationary models as the standard version of BBO, with a sensitivity to a stochastic gravitational wave background {omega}{sub GW}h{sup 2}>10{sup -17}, will only allow a marginal detection of the amplitude while leaving the tensor spectral index at 0.1 Hz unconstrained. Also, inflationary models with a large tensor-to-scalar ratio predict a substantial negative tensor spectral index such that the gravitational wave amplitude is damped at direct detection frequencies. We also discuss the extent to which CMB measurements can be used to predict the gravitational wave background amplitude in a direct detection experiment and how any measurement of the amplitude and the spectral tilt of the gravitational wave background at direct detection frequencies together with the CMB tensor-to-scalar ratio can be used to establish slow-roll inflation.

Friedman, Brett C.; Cooray, Asantha; Melchiorri, Alessandro [Center for Cosmology, Department of Physics and Astronomy, University of California, Irvine, California 92697-4575 (United States); Dipartimento di Fisica 'G. Marconi' and INFN, sezione di Roma, Universita di Roma 'La Sapienza', Ple Aldo Moro 5, 00185, Rome (Italy)

2006-12-15

285

Computer-Aided Parallelizer and Optimizer  

NASA Technical Reports Server (NTRS)

The Computer-Aided Parallelizer and Optimizer (CAPO) automates the insertion of compiler directives (see figure) to facilitate parallel processing on Shared Memory Parallel (SMP) machines. While CAPO currently is integrated seamlessly into CAPTools (developed at the University of Greenwich, now marketed as ParaWise), CAPO was independently developed at Ames Research Center as one of the components for the Legacy Code Modernization (LCM) project. The current version takes serial FORTRAN programs, performs interprocedural data dependence analysis, and generates OpenMP directives. Due to the widely supported OpenMP standard, the generated OpenMP codes have the potential to run on a wide range of SMP machines. CAPO relies on accurate interprocedural data dependence information currently provided by CAPTools. Compiler directives are generated through identification of parallel loops in the outermost level, construction of parallel regions around parallel loops and optimization of parallel regions, and insertion of directives with automatic identification of private, reduction, induction, and shared variables. Attempts also have been made to identify potential pipeline parallelism (implemented with point-to-point synchronization). Although directives are generated automatically, user interaction with the tool is still important for producing good parallel codes. A comprehensive graphical user interface is included for users to interact with the parallelization process.

Jin, Haoqiang

2011-01-01

286

Toward Parallel Document Clustering  

SciTech Connect

A key challenge to automated clustering of documents in large text corpora is the high cost of comparing documents in a multimillion dimensional document space. The Anchors Hierarchy is a fast data structure and algorithm for localizing data based on a triangle inequality obeying distance metric, the algorithm strives to minimize the number of distance calculations needed to cluster the documents into anchors around reference documents called pivots. We extend the original algorithm to increase the amount of available parallelism and consider two implementations: a complex data structure which affords efficient searching, and a simple data structure which requires repeated sorting. The sorting implementation is integrated with a text corpora Bag of Words program and initial performance results of end-to-end a document processing workflow are reported.

Mogill, Jace A.; Haglin, David J.

2011-09-01

287

GPU-based Parallel Hybrid Genetic Algorithms  

E-print Network

AbstractOver the last years, interest in hybrid metaheuristics has risen considerably in the field of optimization. Combinations of algorithms such as genetic algorithms (GAs) and local search (LS) methods have provided very powerful search algorithms. However, due to their complexity, the computational time of the solution search exploration remains exorbitant when large problem instances are to be solved. Therefore, the use of GPU-based parallel computing is required as a complementary way to speed up the search. This paper presents a new methodology to design and implement efficiently and effectively hybrid genetic algorithms on GPU accelerators. I. SCHEME OF PARALLELIZATION The adaptation of hybrid GAs on GPU requires to take into account at the same time the characteristics and underlined issues of the GPU architecture and the metaheuristics parallel models. Since the evaluation of the neighborhood is generally the time-consuming

Th Van Luong; Nouredine Melab; El-ghazali Talbi

288

Speculative parallelization of partially parallel loops  

E-print Network

with even one cross- processor flow dependence because we have to re-execute sequentially. Moreover, the existing, partial parallelism of loops is not exploited. We demonstrate a generalization of the speculative doall parallelization tech- nique, called...

Dang, Francis Hoai Dinh

2009-05-15

289

Searching for hard X-ray directivity during the rise, peak, and decay phases of solar flares  

NASA Technical Reports Server (NTRS)

We have identified 72 large solar flares (peak counting rates more than 1000 counts/s) observed by Hard X-ray Burst Spectroscopy (HXRBS) on-board the Solar Maximum Mission (SMM). Using a database of these flares, we have studied hard X-ray (50-850 keV) spectral center-to-limb variation and its evolution with time. The major results are the following: (1) During the rise phase, the center-to-limb spectral variation is small, with a hardness of delta delta = 0.02 +/- 0.25, and a statistical significance of 0.1 sigma. (2) During the peak phase, the center-to-limb variation is delta delta = 0.13 +/- 0.13, with a statistical significance of 1 sigma. (3) During the decay phase, the center-to-limb variation changes to softening. The softness is relatively large with delta delta = -0.25 +/- 0.21, and a statistical significance of 1.2 sigma. (4) The linear least-squares fits to the spectral center-to-limb variations do not have slopes significantly different from zero during all those three phases. (5) The center events and limb events spectral distributions are shown to be not different by using Kolmogorov-Smirnov two-samples test. (6) The fraction of events detected near the limb is marginally consistent with that expected from isotropically emitting flares. (7) On average, flares evolve as soft-hard-soft. These results suggest that there is no statistically significant evidence for hard X-ray directivity during the rise, peak, and decay phases of solar flares. The hard X-ray radiation pattern at those energies is almost isotropic during all those phases. This lack of directivity (or anisotropy) found in this study is not in agreement with the results discovered by Vestrand et al. (1987) in which they found energetic photon source is anisotropic, using SMM Gamma-Ray Spectrometer (GRS) data at a much higher energy band of 0.3-1 MeV. If we want to interpret the results of Vestrand et al. (1987) and our present results in a self-consistent way, we must conclude that at energies of greater than 50 keV, the Compton backscattering suppresses the hard X-ray anisotropy sufficiently so that no significant directivity can be measured during the rise, peak, and decay phases of solar flares. during the rise, peak, and decay phases of solar flares.

Li, Peng

1994-01-01

290

A NICMOS direct imaging search for giant planets around the seven single white dwarfs in the Hyades  

NASA Astrophysics Data System (ADS)

We propose to use the NIC1 camera on HST to search for massive giant planets around the known seven single white dwarfs in the nearby Hyades cluster at sub-arcsec separations. At an age of 625 Myr, the white dwarfs had protogenitor masses of about 3 solar masses, and massive gaseous giant planets should have formed in the massive circumstellar disks around these ex Herbig A0 stars, probably at orbital separations similar or slightly larger than that of Jupiter {5 AU} in our own solar system. Such planets would have survived the post-Main Sequence mass loss of the parent star, and would have migrated outward adiabatically by a factor 4.5, equal to the ratio of initial to final stellar mass {3Mo/0.66Mo}, due to conservation of orbital angular momentum during the mass loss {AGB and PN} phase. Thus the orbital separation NOW would be 4.5 x 5 AU = 22.5 AU, which at the distance of the Hyades {45 pc} corresponds to 0.50 arcsec. Simulations with TinyTim then show that giant planets at this separation with masses in the range 6-12 Jupiter masses and apparent J and H magnitudes in the range 20.5-23.3 mag {from Baraffe or Burrows models} can be spatially resolved around the Hyades white dwarfs. Their J and H brightnesses are known to be 15 +/- 0.5 mag, implying a median star-planet brightness ratio of 1000:1 {7.5 mag}. This combination of dynamic range and orbital separation is observable with NICMOS, by subtracting images taken at two roll angles. Therefore, the proposed near-IR diffraction-limited observations in the F110W and F160W filters promise to resolve giant planets around low-mass stars for the first time. If successful, the observations would also prove that giant planets do form around early-type stars more massive than the Sun.

Zinnecker, Hans

2003-07-01

291

Template based parallel checkpointing in a massively parallel computer system  

SciTech Connect

A method and apparatus for a template based parallel checkpoint save for a massively parallel super computer system using a parallel variation of the rsync protocol, and network broadcast. In preferred embodiments, the checkpoint data for each node is compared to a template checkpoint file that resides in the storage and that was previously produced. Embodiments herein greatly decrease the amount of data that must be transmitted and stored for faster checkpointing and increased efficiency of the computer system. Embodiments are directed to a parallel computer system with nodes arranged in a cluster with a high speed interconnect that can perform broadcast communication. The checkpoint contains a set of actual small data blocks with their corresponding checksums from all nodes in the system. The data blocks may be compressed using conventional non-lossy data compression algorithms to further reduce the overall checkpoint size.

Archer, Charles Jens (Rochester, MN); Inglett, Todd Alan (Rochester, MN)

2009-01-13

292

Coping with anomalies in parallel branch-and-bound algorithms  

SciTech Connect

A general technique that can be used to solve a wide variety of discrete optimization problems is the branch-and-bound algorithm. The authors have adapted and extended branch-and-bound algorithms for parallel processing. The computational efficiency of these algorithms depends on the allowance function, the data structure, and the search strategies. Anomalies owing to parallelism may occur. In this correspondence, anomalies of parallel branch-and-bound algorithms using the same search strategy as the corresponding serial algorithms are studied. Sufficient conditions to guarantee no degradation in performance due to parallelism and necessary conditions for allowing parallelism to have a speedup greater than the number of processors are presented.

Li, G.J.; Wah, B.W.

1986-06-01

293

Special parallel processing workshop  

SciTech Connect

This report contains viewgraphs from the Special Parallel Processing Workshop. These viewgraphs deal with topics such as parallel processing performance, message passing, queue structure, and other basic concept detailing with parallel processing.

NONE

1994-12-01

294

B physics: measurement of partial widths and search for direct cp violation in d0 meson decays  

SciTech Connect

We present a measurement of relative partial widths and decay rate CP asymmetries in K{sup -}K{sup +} and {pi}{sup -}{pi}{sup +} decays of D{sup 0} mesons produced in p{bar p} collisions at {radical}s = 1.96TeV. We use a sample of 2 x 10{sup 5} D*{sup +} {yields} D{sup 0}{pi}{sup +} (and charge conjugate) decays with the D{sup 0} decaying to K{sup -}{pi}{sup +}, K{sup -}K{sup +}, and {pi}{sup -}{pi}{sup +}, corresponding to 123 pb{sup -1} of data collected by the Collider Detector at Fermilab II experiment at the Fermilab Tevatron collider. No significant direct CP violation is observed. We measure {Lambda}(D{sup 0} {yields} K{sup -}K{sup +})/{Lambda}(D{sup 0} {yields} K{sup -}{pi}{sup +}) = 0.0992 {+-} 0.0011 {+-} 0.0012, {Lambda}(D{sup 0} {yields} {pi}{sup -}{pi}{sup +})/{Lambda}(D{sup 0} {yields} K{sup -}{pi}{sup +}) = 0.03594 {+-} 0.00054 {+-} 0.00040, A{sub CP} (K{sup -}K{sup +}) = (2.0 {+-} 1.2 {+-} 0.6)%, and A{sub CP} ({pi}{sup -}{pi}{sup +}) = (1.0 {+-} 1.3 {+-} 0.6) %, where, in all cases, the first uncertainty is statistical and the second is systematic.

Acosta, D.; The CDF Collaboration

2005-04-04

295

Calculation of geometric phases in electric dipole searches with trapped spin-1/2 particles based on direct solution of the Schrdinger equation  

NASA Astrophysics Data System (ADS)

Pendlebury etal . [Phys. Rev. A 70, 032102 (2004), 10.1103/PhysRevA.70.032102] were the first to investigate the role of geometric phases in searches for an electric dipole moment (EDM) of elementary particles based on Ramsey-separated oscillatory field magnetic resonance with trapped ultracold neutrons and comagnetometer atoms. Their work was based on the Bloch equation and later work using the density matrix corroborated the results and extended the scope to describe the dynamics of spins in general fields and in bounded geometries. We solve the Schrdinger equation directly for cylindrical trap geometry and obtain a full description of EDM-relevant spin behavior in general fields, including the short-time transients and vertical spin oscillation in the entire range of particle velocities. We apply this method to general macroscopic fields and to the field of a microscopic magnetic dipole.

Steyerl, A.; Kaufman, C.; Mller, G.; Malik, S. S.; Desai, A. M.; Golub, R.

2014-05-01

296

Calculation of geometric phases in electric dipole searches with trapped spin-1/2 particles based on direct solution of the Schrdinger equation  

E-print Network

Pendlebury $\\textit{et al.}$ [Phys. Rev. A $\\textbf{70}$, 032102 (2004)] were the first to investigate the role of geometric phases in searches for an electric dipole moment (EDM) of elementary particles based on Ramsey-separated oscillatory field magnetic resonance with trapped ultracold neutrons and comagnetometer atoms. Their work was based on the Bloch equation and later work using the density matrix corroborated the results and extended the scope to describe the dynamics of spins in general fields and in bounded geometries. We solve the Schr\\"odinger equation directly for cylindrical trap geometry and obtain a full description of EDM-relevant spin behavior in general fields, including the short-time transients and vertical spin oscillation in the entire range of particle velocities. We apply this method to general macroscopic fields and to the field of a microscopic magnetic dipole.

A. Steyerl; C. Kaufman; G. Mller; S. S. Malik; A. M. Desai; R. Golub

2014-03-04

297

Coherent parallel C  

Microsoft Academic Search

Coherent Parallel C (CPC) is an extension of C for parallelism. The extensions are not simply parallel for loops; instead, a data parallel programming model is adopted. This means that one has an entire process for each data object. An example of an object is one mesh point in a finite element solver. How the processes are actually distributed on

Edward W. Felten; Steve W. Otto

1988-01-01

298

Parallel Mandelbrot Set Model  

NSDL National Science Digital Library

The Parallel Mandelbrot Set Model is a parallelization of the sequential MandelbrotSet model, which does all the computations on a single processor core. This parallelization is able to use a computer with more than one cores (or processors) to carry out the same computation, thus speeding up the process. The parallelization is done using the model elements in the Parallel Java group. These model elements allow easy use of the Parallel Java library created by Alan Kaminsky. In particular, the parallelization used for this model is based on code in Chapters 11 and 12 of Kaminsky's book Building Parallel Java. The Parallel Mandelbrot Set Model was developed using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double click the ejs_chaos_ParallelMandelbrotSet.jar file to run the program if Java is installed.

Franciscouembre

2011-11-24

299

Computing Flow Transition On Parallel Processors  

NASA Technical Reports Server (NTRS)

Parallel algorithm developed on multiple-microprocessor computer. Program initiated to develop computer codes capable of directly simulating and mathematically modeling transition process at mach numbers ranging from subsonic to hypersonic. Parallel computers potentially offer reduction of processing time; processing time inversely proportional to number of available processors.

Bokhari, S.; Erlebacher, G.; Hussaini, M. Y.

1993-01-01

300

Parallel Computing for Seismic Geotechnical Applications  

Microsoft Academic Search

Parallel computing is gradually becoming a main stream tool in geotechnical simulations. The need for high fidelity and for modeling of fairly large 3 -dimensional (3D) spatial configurations is motivating this direct ion of research. A new program ParC YCLIC for seismic geotechnical applications has been developed. Salient characteristics of the employed parallel sparse solver will be presented. Using this

Jinchi Lu; Ahmed Elgamal; Kincho H. Law; Zhaohui Yang

301

Integrated Task and Data Parallel Programming  

NASA Technical Reports Server (NTRS)

This research investigates the combination of task and data parallel language constructs within a single programming language. There are an number of applications that exhibit properties which would be well served by such an integrated language. Examples include global climate models, aircraft design problems, and multidisciplinary design optimization problems. Our approach incorporates data parallel language constructs into an existing, object oriented, task parallel language. The language will support creation and manipulation of parallel classes and objects of both types (task parallel and data parallel). Ultimately, the language will allow data parallel and task parallel classes to be used either as building blocks or managers of parallel objects of either type, thus allowing the development of single and multi-paradigm parallel applications. 1995 Research Accomplishments In February I presented a paper at Frontiers 1995 describing the design of the data parallel language subset. During the spring I wrote and defended my dissertation proposal. Since that time I have developed a runtime model for the language subset. I have begun implementing the model and hand-coding simple examples which demonstrate the language subset. I have identified an astrophysical fluid flow application which will validate the data parallel language subset. 1996 Research Agenda Milestones for the coming year include implementing a significant portion of the data parallel language subset over the Legion system. Using simple hand-coded methods, I plan to demonstrate (1) concurrent task and data parallel objects and (2) task parallel objects managing both task and data parallel objects. My next steps will focus on constructing a compiler and implementing the fluid flow application with the language. Concurrently, I will conduct a search for a real-world application exhibiting both task and data parallelism within the same program. Additional 1995 Activities During the fall I collaborated with Andrew Grimshaw and Adam Ferrari to write a book chapter which will be included in Parallel Processing in C++ edited by Gregory Wilson. I also finished two courses, Compilers and Advanced Compilers, in 1995. These courses complete my class requirements at the University of Virginia. I have only my dissertation research and defense to complete.

Grimshaw, A. S.

1998-01-01

302

Ejs Parallel Plate Capacitor Model  

NSDL National Science Digital Library

The Ejs Parallel Plate Capacitor model displays a parallel-plate capacitor which consists of two identical metal plates, placed parallel to one another. The capacitor can be charged by connecting one plate to the positive terminal of a battery and the other plate to the negative terminal. The dielectric constant and the separation of the plates can be changed via sliders. You can modify this simulation if you have Ejs installed by right-clicking within the plot and selecting "Open Ejs Model" from the pop-up menu item. Ejs Parallel Plate Capacitor model was created using the Easy Java Simulations (Ejs) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_bu_capacitor.jar file will run the program if Java is installed. Ejs is a part of the Open Source Physics Project and is designed to make it easier to access, modify, and generate computer models. Additional Ejs models for Newtonian mechanics are available. They can be found by searching ComPADRE for Open Source Physics, OSP, or Ejs.

Duffy, Andrew

2008-07-14

303

Compiling for NUMA Parallel Machines  

E-print Network

Compiling for NUMA Parallel Machines Abstract A common feature of many scalable parallel machines is non-uniform memory access (NUMA). A parallelizing compiler for NUMA parallel ma- chines must exploit both parallelism and data locality

Zanibbi, Richard

304

Guidelines for treating mental illness: love them, hate them. Can the SIEP-DIRECT'S Project serve in the search for a happy medium?  

PubMed

This paper discusses some key aspects of the debate on the difficulties of incorporating scientific evidence into the daily work of clinicians in mental health services (MHS). It highlights the topics of: the utility of guidelines in this field, the ethical principles that should guide their utilisation, their limitations, obstacles impeding the diffusion of guidelines in psychiatry, and strategies that can be useful for overcoming the barriers to guideline implementation. The SIEP-DIRECT'S ((DIscrepancy between Routine practice and Evidence in psychiatric Community Treatments on Schizophrenia) Project's potential role in fostering this advancement is discussed in detail. This Project developed a set of 103 indicators that operationalised the NICE clinical guidelines for schizophrenia recommendations and tested them in 19 MHS in Italy. A multi-step design was used to assess recommendation and indicator acceptability in the Italian context; provide an assessment of any current discrepancies between routine practice and guideline recommendations in the treatment of schizophrenia; and understand the reasons for any discrepancies that might emerge. This process, moreover, was instrumental in keeping the debate arising during conduction of this Project far from the excesses of hostility - and excesses of "bright-eyed enthusiasm" - that frequently influence discussion on topic. This Project therefore showed potential to serve in the search for a happy medium, that can facilitate the pursuit of a fundamental advancement in guideline implementation in mental health services. PMID:19024716

Ruggeri, Mirella

2008-01-01

305

Search for direct top-squark pair production in final states with two leptons in pp collisions at = 8 TeV with the ATLAS detector  

NASA Astrophysics Data System (ADS)

A search is presented for direct top-squark pair production in final states with two leptons (electrons or muons) of opposite charge using 20.3 fb-1 of pp collision data at = 8 TeV, collected by the ATLAS experiment at the Large Hadron Collider in 2012. No excess over the Standard Model expectation is found. The results are interpreted under the separate assumptions (i) that the top squark decays to a b-quark in addition to an on-shell chargino whose decay occurs via a real or virtual W boson, or (ii) that the top squark decays to a t-quark and the lightest neutralino. A top squark with a mass between 150 GeV and 445 GeV decaying to a b-quark and an on-shell chargino is excluded at 95% confidence level for a top squark mass equal to the chargino mass plus 10 GeV, in the case of a 1 GeV lightest neutralino. Top squarks with masses between 215 (90) GeV and 530 (170) GeV decaying to an on-shell (off-shell) t-quark and a neutralino are excluded at 95% confidence level for a 1 GeV neutralino. [Figure not available: see fulltext.

Aad, G.; Abajyan, T.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.; Agatonovic-Jovin, T.; Aguilar-Saavedra, J. A.; Agustoni, M.; Ahlen, S. P.; Ahmad, A.; Ahmadov, F.; Aielli, G.; kesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Albert, J.; Albrand, S.; Verzini, M. J. Alconada; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Alimonti, G.; Alio, L.; Alison, J.; Allbrooke, B. M. M.; Allison, L. J.; Allport, P. P.; Allwood-Spiers, S. E.; Almond, J.; Aloisio, A.; Alon, R.; Alonso, A.; Alonso, F.; Alpigiani, C.; Altheimer, A.; Gonzalez, B. Alvarez; Alviggi, M. G.; Amako, K.; Coutinho, Y. Amaral; Amelung, C.; Amidei, D.; Ammosov, V. V.; Santos, S. P. Amor Dos; Amorim, A.; Amoroso, S.; Amram, N.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Anduaga, X. S.; Angelidakis, S.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Bella, L. Aperio; Apolle, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Araque, J. P.; Arce, A. T. H.; Arguin, J.-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Arslan, O.; Artamonov, A.; Artoni, G.; Asai, S.; Asbah, N.; Ashkenazi, A.; Ask, S.; sman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Auerbach, B.; Auge, E.; Augsten, K.; Aurousseau, M.; Avolio, G.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Bacci, C.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Backus Mayes, J.; Badescu, E.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bailey, D. C.; Bain, T.; Baines, J. T.; Baker, O. K.; Baker, S.; Balek, P.; Balli, F.; Banas, E.; Banerjee, Sw.; Banfi, D.; Bangert, A.; Bannoura, A. A. E.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barber, T.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Barnovska, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimares da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartos, P.; Bartsch, V.; Bassalat, A.; Basye, A.; Bates, R. L.; Batkova, L.; Batley, J. R.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, S.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Behr, K.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belloni, A.; Beloborodova, O. L.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Berglund, E.; Beringer, J.; Bernard, C.; Bernat, P.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertolucci, F.; Besana, M. I.; Besjes, G. J.; Bessidskaia, O.; Besson, N.; Betancourt, C.; Bethke, S.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Bierwagen, K.; Biesiada, J.; Biglietti, M.; De Mendizabal, J. Bilbao; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J.-B.; Blazek, T.; Bloch, I.; Blocker, C.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Boddy, C. R.; Boehler, M.; Boek, J.; Boek, T. T.; Bogaerts, J. A.; Bogdanchikov, A. G.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Boldyrev, A. S.; Bolnet, N. M.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Borri, M.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutouil, S.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozovic-Jelisavcic, I.; Bracinik, J.; Branchini, P.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brelier, B.; Brendlinger, K.; Brennan, A. J.; Brenner, R.; Bressler, S.; Bristow, K.; Bristow, T. M.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Bromberg, C.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Brown, G.; Brown, J.; de Renstrom, P. A. Bruckman; Bruncko, D.; Bruneliere, R.

2014-06-01

306

Parallel Implicit Algorithms for CFD  

NASA Technical Reports Server (NTRS)

The main goal of this project was efficient distributed parallel and workstation cluster implementations of Newton-Krylov-Schwarz (NKS) solvers for implicit Computational Fluid Dynamics (CFD.) "Newton" refers to a quadratically convergent nonlinear iteration using gradient information based on the true residual, "Krylov" to an inner linear iteration that accesses the Jacobian matrix only through highly parallelizable sparse matrix-vector products, and "Schwarz" to a domain decomposition form of preconditioning the inner Krylov iterations with primarily neighbor-only exchange of data between the processors. Prior experience has established that Newton-Krylov methods are competitive solvers in the CFD context and that Krylov-Schwarz methods port well to distributed memory computers. The combination of the techniques into Newton-Krylov-Schwarz was implemented on 2D and 3D unstructured Euler codes on the parallel testbeds that used to be at LaRC and on several other parallel computers operated by other agencies or made available by the vendors. Early implementations were made directly in Massively Parallel Integration (MPI) with parallel solvers we adapted from legacy NASA codes and enhanced for full NKS functionality. Later implementations were made in the framework of the PETSC library from Argonne National Laboratory, which now includes pseudo-transient continuation Newton-Krylov-Schwarz solver capability (as a result of demands we made upon PETSC during our early porting experiences). A secondary project pursued with funding from this contract was parallel implicit solvers in acoustics, specifically in the Helmholtz formulation. A 2D acoustic inverse problem has been solved in parallel within the PETSC framework.

Keyes, David E.

1998-01-01

307

DC Circuits: Parallel Resistances  

NSDL National Science Digital Library

In this interactive learning activity, students will learn about parallel circuits. They will measure and calculate the resistance of parallel circuits and answer several questions about the example circuit shown.

2013-07-30

308

Parallel flow diffusion battery  

DOEpatents

A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

Yeh, Hsu-Chi (Albuquerque, NM); Cheng, Yung-Sung (Albuquerque, NM)

1984-08-07

309

Parallel flow diffusion battery  

DOEpatents

A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

Yeh, H.C.; Cheng, Y.S.

1984-01-01

310

Parallelizing Timed Petri Net simulations  

NASA Technical Reports Server (NTRS)

The possibility of using parallel processing to accelerate the simulation of Timed Petri Nets (TPN's) was studied. It was recognized that complex system development tools often transform system descriptions into TPN's or TPN-like models, which are then simulated to obtain information about system behavior. Viewed this way, it was important that the parallelization of TPN's be as automatic as possible, to admit the possibility of the parallelization being embedded in the system design tool. Later years of the grant were devoted to examining the problem of joint performance and reliability analysis, to explore whether both types of analysis could be accomplished within a single framework. In this final report, the results of our studies are summarized. We believe that the problem of parallelizing TPN's automatically for MIMD architectures has been almost completely solved for a large and important class of problems. Our initial investigations into joint performance/reliability analysis are two-fold; it was shown that Monte Carlo simulation, with importance sampling, offers promise of joint analysis in the context of a single tool, and methods for the parallel simulation of general Continuous Time Markov Chains, a model framework within which joint performance/reliability models can be cast, were developed. However, very much more work is needed to determine the scope and generality of these approaches. The results obtained in our two studies, future directions for this type of work, and a list of publications are included.

Nicol, David M.

1993-01-01

311

Parallel-vector computation for linear structural analysis and non-linear unconstrained optimization problems  

NASA Technical Reports Server (NTRS)

Several parallel-vector computational improvements to the unconstrained optimization procedure are described which speed up the structural analysis-synthesis process. A fast parallel-vector Choleski-based equation solver, pvsolve, is incorporated into the well-known SAP-4 general-purpose finite-element code. The new code, denoted PV-SAP, is tested for static structural analysis. Initial results on a four processor CRAY 2 show that using pvsolve reduces the equation solution time by a factor of 14-16 over the original SAP-4 code. In addition, parallel-vector procedures for the Golden Block Search technique and the BFGS method are developed and tested for nonlinear unconstrained optimization. A parallel version of an iterative solver and the pvsolve direct solver are incorporated into the BFGS method. Preliminary results on nonlinear unconstrained optimization test problems, using pvsolve in the analysis, show excellent parallel-vector performance indicating that these parallel-vector algorithms can be used in a new generation of finite-element based structural design/analysis-synthesis codes.

Nguyen, D. T.; Al-Nasra, M.; Zhang, Y.; Baddourah, M. A.; Agarwal, T. K.; Storaasli, O. O.; Carmona, E. A.

1991-01-01

312

Verbal and Visual Parallelism  

ERIC Educational Resources Information Center

This study investigates the practice of presenting multiple supporting examples in parallel form. The elements of parallelism and its use in argument were first illustrated by Aristotle. Although real texts may depart from the ideal form for presenting multiple examples, rhetorical theory offers a rationale for minimal, parallel presentation. The

Fahnestock, Jeanne

2003-01-01

313

Parallel simulation today  

NASA Technical Reports Server (NTRS)

This paper surveys topics that presently define the state of the art in parallel simulation. Included in the tutorial are discussions on new protocols, mathematical performance analysis, time parallelism, hardware support for parallel simulation, load balancing algorithms, and dynamic memory management for optimistic synchronization.

Nicol, David; Fujimoto, Richard

1992-01-01

314

Special issue on parallelism  

Microsoft Academic Search

The articles presented in our Special Issue on parallel processing on the supercomputing scale reflect, to some extent, splits in the community developing these machines. There are several schools of thought on how best to implement parallel processing at both the hard- and software levels. Controversy exists over the wisdom of aiming for general- or special-purpose parallel machines, and what

Karen A. Frenkel

1986-01-01

315

DYNAMIC LANGUAGE PARALLELIZATION  

E-print Network

DYNAMIC LANGUAGE PARALLELIZATION By Lorenz F. Huelsbergen A thesis submitted in partial fulfillment { MADISON 1993 #12;c Copyright 1993 by Lorenz F. Huelsbergen ii #12;DYNAMIC LANGUAGE PARALLELIZATION Lorenz F. Huelsbergen, Ph.D. University of Wisconsin{Madison 1993 Dynamic language parallelization is a new

Huelsbergen, Lorenz

316

Decomposing the Potentially Parallel  

NSDL National Science Digital Library

This course provides an introduction to the issues involved in decomposing problems onto parallel machines, and to the types of architectures and programming styles commonly found in parallel computers. The list of topics discussed includes types of decomposition, task farming, regular domain decomposition, unbalanced grids, and parallel molecular dynamics.

Elspeth Minty, Robert Davey, Alan Simpson, David Henty

317

Parallel Global Aircraft Configuration Design Space Exploration  

Microsoft Academic Search

The preliminary design space exploration for large, interdisciplinary engineering problems is often a difficult and time-consuming task. General techniques are needed that efficiently and methodically search the design space. This work focuses on the use of parallel load balancing techniques integrated with a global optimizer to reduce the computational time of the design space exploration. The method is applied to

CHUCK A. BAKER; LAYNE T. WATSON; BERNARD GROSSMAN; WILLIAM H. MASON; RAPHAEL T. HAFTKA

1999-01-01

318

Serial, covert shifts of attention during visual search are reflected by the frontal eye fields and correlated with population oscillations.  

PubMed

Attention regulates the flood of sensory information into a manageable stream, and so understanding how attention is controlled is central to understanding cognition. Competing theories suggest visual search involves serial and/or parallel allocation of attention, but there is little direct, neural evidence for either mechanism. Two monkeys were trained to covertly search an array for a target stimulus under visual search (endogenous) and pop-out (exogenous) conditions. Here, we present neural evidence in the frontal eye fields (FEF) for serial, covert shifts of attention during search but not pop-out. Furthermore, attention shifts reflected in FEF spiking activity were correlated with 18-34 Hz oscillations in the local field potential, suggesting a "clocking" signal. This provides direct neural evidence that primates can spontaneously adopt a serial search strategy and that these serial covert shifts of attention are directed by the FEF. It also suggests that neuron population oscillations may regulate the timing of cognitive processing. PMID:19679077

Buschman, Timothy J; Miller, Earl K

2009-08-13

319

Serial, Covert, Shifts of Attention during Visual Search are Reflected by the Frontal Eye Fields and Correlated with Population Oscillations  

PubMed Central

Attention regulates the flood of sensory information into a manageable stream, and so understanding how attention is controlled is central to understanding cognition. Competing theories suggest visual search involves serial and/or parallel allocation of attention, but there is little direct, neural, evidence for either mechanism. Two monkeys were trained to covertly search an array for a target stimulus under visual search (endogenous) and pop-out (exogenous) conditions. Here we present neural evidence in the frontal eye fields (FEF) for serial, covert shifts of attention during search but not pop-out. Furthermore, attention shifts reflected in FEF spiking activity were correlated with 1834 Hz oscillations in the local field potential, suggesting a clocking signal. This provides direct neural evidence that primates can spontaneously adopt a serial search strategy and that these serial covert shifts of attention are directed by the FEF. It also suggests that neuron population oscillations may regulate the timing of cognitive processing. PMID:19679077

Buschman, Timothy J.; Miller, Earl K.

2009-01-01

320

A parallel pairwise local sequence alignment algorithm.  

PubMed

Researchers are compelled to use heuristic-based pairwise sequence alignment tools instead of Smith-Waterman (SW) algorithm due to space and time constraints, thereby losing significant amount of sensitivity. Parallelization is a possible solution, though, till date, the parallelization is restricted to database searching through database fragmentation. In this paper, the power of a cluster computer is utilized for developing a parallel algorithm, RPAlign, involving, first, the detection of regions that are potentially alignable, followed by their actual alignment. RPAlign is found to reduce the timing requirement by a factor of upto 9 and 99 when used with the basic local alignment search tool (BLAST) and SW, respectively, while keeping the sensitivity similar to the corresponding method. For distantly related sequences, which remain undetected by BLAST, RPAlign with SW can be used. Again, for megabase-scale sequences, when SW becomes computationally intractable, the proposed method can still align them reasonably fast with high sensitivity. PMID:19366648

Bandyopadhyay, Sanghamitra; Mitra, Ramkrishna

2009-06-01

321

Parallel Atomistic Simulations  

SciTech Connect

Algorithms developed to enable the use of atomistic molecular simulation methods with parallel computers are reviewed. Methods appropriate for bonded as well as non-bonded (and charged) interactions are included. While strategies for obtaining parallel molecular simulations have been developed for the full variety of atomistic simulation methods, molecular dynamics and Monte Carlo have received the most attention. Three main types of parallel molecular dynamics simulations have been developed, the replicated data decomposition, the spatial decomposition, and the force decomposition. For Monte Carlo simulations, parallel algorithms have been developed which can be divided into two categories, those which require a modified Markov chain and those which do not. Parallel algorithms developed for other simulation methods such as Gibbs ensemble Monte Carlo, grand canonical molecular dynamics, and Monte Carlo methods for protein structure determination are also reviewed and issues such as how to measure parallel efficiency, especially in the case of parallel Monte Carlo algorithms with modified Markov chains are discussed.

HEFFELFINGER,GRANT S.

2000-01-18

322

Characterizing the parallelism in rule-based expert systems  

SciTech Connect

A brief review of two classes of rule-based expert systems is presented, followed by a detailed analysis of potential sources of parallelism at the production or rule level, the subrule level (including match, select, and act parallelism), and at the search level (including AND, OR, and stream parallelism). The potential amount of parallelism from each source is discussed and characterized in terms of its granularity, inherent serial constraints, efficiency, speedup, dynamic behavior, and communication volume, frequency, and topology. Subrule parallelism will yield, at best, two- to tenfold speedup, and rule level parallelism will yield a modest speedup on the order of 5 to 10 times. Rule level can be combined with OR, AND, and stream parallelism in many instances to yield further parallel speedups.

Douglass, R.J.

1984-01-01

323

Fast parallel architecture for automated identification  

NASA Astrophysics Data System (ADS)

The problem of using a search set of fingerprints to identify an individual as a member of a very large existing repository has long been of interest to law enforcement agencies. Partially automated approaches have been used that require significant search space reduction before automated techniques can be used. The time required to perform such an identification becomes onerous as the repository population size increases. An architectural approach to fully automating this one-on-many identification problem is presented and described. The use of automated search space reduction techniques combined with repository distribution across the architecture results in rapid identification response times by implementing a fully parallelized search. The architecture supports scalability in both workload and repository population. A detailed architectural simulation model was created and results were generated to predict performance. These results are presented and substantiate rapid identification response to one-on-many searches of very large fingerprint feature repositories.

Sura, John; Rudy, R.; Larsen, R.; Juttlestad, E.; Marant, B.

1997-02-01

324

Parallel Shortest Lattice Vector Enumeration on Graphics Cards  

E-print Network

of parallel computing systems. To illustrate the algorithm, it was implemented on graphics cards using CUDA, exhaustive search 1 Introduction Lattice-based cryptosystems are assumed to be secure against quantum com, especially to implementation aspects. In this paper we consider parallelization and special hardware

325

Evolutionary Neural Network parallelization with multicore systems on chip  

Microsoft Academic Search

Evolutionary Neural Network (ENN) has attracted great attention among the researchers in recent years because of its effectiveness at function optimization and, its efficiency in searching large and complex spaces to find nearly global optima. In this work, Parallel Evolutionary Neural Network algorithm is proposed and implemented on Multi-core system on chip. The algorithm is parallelized, partitioned, mapped, and scheduled

Mohammad Wadood Majid; Golrokh Mirzaei; Mohsin M. Jamali

2012-01-01

326

Parallel digital forensics infrastructure.  

SciTech Connect

This report documents the architecture and implementation of a Parallel Digital Forensics infrastructure. This infrastructure is necessary for supporting the design, implementation, and testing of new classes of parallel digital forensics tools. Digital Forensics has become extremely difficult with data sets of one terabyte and larger. The only way to overcome the processing time of these large sets is to identify and develop new parallel algorithms for performing the analysis. To support algorithm research, a flexible base infrastructure is required. A candidate architecture for this base infrastructure was designed, instantiated, and tested by this project, in collaboration with New Mexico Tech. Previous infrastructures were not designed and built specifically for the development and testing of parallel algorithms. With the size of forensics data sets only expected to increase significantly, this type of infrastructure support is necessary for continued research in parallel digital forensics. This report documents the implementation of the parallel digital forensics (PDF) infrastructure architecture and implementation.

Liebrock, Lorie M. (New Mexico Tech, Socorro, NM); Duggan, David Patrick

2009-10-01

327

Languages for parallel architectures  

SciTech Connect

This book presents mathematical methods for modelling parallel computer architectures, based on the results of ESPRIT's project 415 on computer languages for parallel architectures. Presented are investigations incorporating a wide variety of programming styles, including functional,logic, and object-oriented paradigms. Topics cover include Philips's parallel object-oriented language POOL, lazy-functional languages, the languages IDEAL, K-LEAF, FP2, and Petri-net semantics for the AADL language.

Bakker, J.W.

1989-01-01

328

Optimistic parallelism requires abstractions  

Microsoft Academic Search

The problem of writing software for multicore processors is greatly simplified if we could automatically parallelize sequential programs. Although auto-parallelization has been studied for many decades, it has succeeded only in a few application areas such as dense matrix computations. In particular, auto-parallelization of irregular programs, which are organized around large, pointer-based data struc- tures like graphs, has seemed intractable.

Milind Kulkarni; Keshav Pingali; Bruce Walter; Ganesh Ramanarayanan; Kavita Bala; L. Paul Chew

2007-01-01

329

Complexity of parallel algorithms  

SciTech Connect

This thesis addresses a number of theoretical issues in parallel computation. There are many open questions relating to what can be done with parallel computers and what are the most effective techniques to use to develop parallel algorithms. The author examines various problems in hope of gaining insight to the general questions. One topic investigated is the relationship between sequential and parallel algorithms. Introduced is the concept of a P-complete algorithm to capture what it means for an algorithm to be inherently sequential . It is shown that a number of sequential greedy algorithms are P-complete, including the greedy algorithm for finding a path in a graph. However, a problem is not necessarily difficult if an algorithm to solve it is P-complete. In some cases, the natural sequential algorithm is P-complete but a different technique gives a fast parallel algorithm. This shows that it is necessary to use different techniques for parallel computation than are used for sequential computation. Fast parallel algorithms for a number of simple graph theory problems are given. The algorithms illustrate a number of different techniques that are useful for parallel algorithms. The final topic that we address is parallel approximation of P-complete problems.

Anderson

1985-11-01

330

Complexity of parallel algorithms  

SciTech Connect

This thesis addresses a number of theoretical issues in parallel computation. There are many open questions relating to what can be done with parallel computers and what are the most effective techniques to use to develop parallel algorithms. Various problems are examined in hope of gaining insight to the general questions. One topic investigated is the relationship between sequential and parallel algorithms. The concept of a P-complete algorithm is introduced to capture what it means for an algorithm to be inherently sequential. It is shown that a number of sequential greedy algorithms are P-complete, including the greedy algorithm for finding a path in a graph. However, an algorithm being P-complete does not necessarily mean that the problem is difficult. In some cases, the natural sequential algorithm is P-complete but a different technique gives a fast parallel algorithm. This shows that it is necessary to use different techniques for parallel computation than are used for sequential computation. Fast parallel algorithms are given for a number of simple graph theory problems. The algorithms illustrate a number of different techniques that are useful for parallel algorithms. A number of results on approximating P-complete problems with parallel algorithms are given that are similar to results on approximating NP-complete problems with sequential algorithms.

Anderson, R.J.

1986-01-01

331

Parallelizing and De-parallelizing Elimination Orders.  

National Technical Information Service (NTIS)

The order in which the variables of a linear system are processed determines the total amounts of fill and work to perform LU decomposition on the system. We identify a trade off between the amounts of fill and work for a given order and the parallelism i...

C. F. Bornstein

1998-01-01

332

A parallel gravitational N-body kernel  

E-print Network

We describe source code level parallelization for the {\\tt kira} direct gravitational $N$-body integrator, the workhorse of the {\\tt starlab} production environment for simulating dense stellar systems. The parallelization strategy, called ``j-parallelization'', involves the partition of the computational domain by distributing all particles in the system among the available processors. Partial forces on the particles to be advanced are calculated in parallel by their parent processors, and are then summed in a final global operation. Once total forces are obtained, the computing elements proceed to the computation of their particle trajectories. We report the results of timing measurements on four different parallel computers, and compare them with theoretical predictions. The computers employ either a high-speed interconnect, a NUMA architecture to minimize the communication overhead or are distributed in a grid. The code scales well in the domain tested, which ranges from 1024 - 65536 stars on 1 - 128 proc...

Zwart, Simon Portegies; Groen, Derek; Gualandris, Alessia; Sipior, Michael; Vermin, Willem

2007-01-01

333

A parallel variable metric optimization algorithm  

NASA Technical Reports Server (NTRS)

An algorithm, designed to exploit the parallel computing or vector streaming (pipeline) capabilities of computers is presented. When p is the degree of parallelism, then one cycle of the parallel variable metric algorithm is defined as follows: first, the function and its gradient are computed in parallel at p different values of the independent variable; then the metric is modified by p rank-one corrections; and finally, a single univariant minimization is carried out in the Newton-like direction. Several properties of this algorithm are established. The convergence of the iterates to the solution is proved for a quadratic functional on a real separable Hilbert space. For a finite-dimensional space the convergence is in one cycle when p equals the dimension of the space. Results of numerical experiments indicate that the new algorithm will exploit parallel or pipeline computing capabilities to effect faster convergence than serial techniques.

Straeter, T. A.

1973-01-01

334

Impact of a nurse-directed, coordinated school health program to enhance physical activity behaviors and reduce body mass index among minority children: A parallel-group, randomized control trial  

PubMed Central

Background Underserved children, particularly girls and those in urban communities, do not meet the recommended physical activity guidelines (>60 min of daily physical activity), and this behavior can lead to obesity. The school years are known to be a critical period in the life course for shaping attitudes and behaviors. Children look to schools for much of their access to physical activity. Thus, through the provision of appropriate physical activity programs, schools have the power to influence apt physical activity choices, especially for underserved children where disparities in obesity-related outcomes exist. Objectives To evaluate the impact of a nurse directed, coordinated, culturally sensitive, school-based, family-centered lifestyle program on activity behaviors and body mass index. Design, settings and participants: This was a parallel group, randomized controlled trial utilizing a community-based participatory research approach, through a partnership with a University and 5 community schools. Participants included 251 children ages 812 from elementary schools in urban, low-income neighborhoods in Los Angeles, USA. Methods The intervention included Kids N Fitness, a 6-week program which met weekly to provide 45 min of structured physical activity and a 45 min nutrition education class for parents and children. Intervention sites also participated in school-wide wellness activities, including health and counseling services, staff professional development in health promotion, parental education newsletters, and wellness policies for the provision of healthy foods at the school. The Child and Adolescent Trial for Cardiovascular Health School Physical Activity and Nutrition Student Questionnaire measured physical activity behavior, including: daily physical activity, participation in team sports, attending physical education class, and TV viewing/computer game playing. Anthropometric measures included height, weight, body mass index, resting blood pressure, and waist circumference. Measures were collected at baseline, completion of the intervention phase (4 months), and 12 months post-intervention. Results Significant results for students in the intervention, included for boys decreases in TV viewing; and girls increases in daily physical activity, physical education class attendance, and decreases in body mass index z-scores from baseline to the 12 month follow-up. Conclusions Our study shows the value of utilizing nurses to implement a culturally sensitive, coordinated, intervention to decrease disparities in activity and TV viewing among underserved girls and boys. PMID:23021318

Wright, Kynna; Giger, Joyce Newman; Norris, Keth; Suro, Zulma

2013-01-01

335

Optimistic parallelism requires abstractions  

Microsoft Academic Search

Irregular applications, which manipulate large, pointer-based data structures like graphs, are difficult to parallelize manually. Automatic tools and techniques such as restructuring compilers and run-time speculative execution have failed to uncover much parallelism in these applications, in spite of a lot of effort by the research community. These difficulties have even led some researchers to wonder if there is any

Milind Kulkarni; Keshav Pingali; Bruce Walter; Ganesh Ramanarayanan; Kavita Bala; L. Paul Chew

2007-01-01

336

Parallelization of thermochemical nanolithography.  

PubMed

One of the most pressing technological challenges in the development of next generation nanoscale devices is the rapid, parallel, precise and robust fabrication of nanostructures. Here, we demonstrate the possibility to parallelize thermochemical nanolithography (TCNL) by employing five nano-tips for the fabrication of conjugated polymer nanostructures and graphene-based nanoribbons. PMID:24337109

Carroll, Keith M; Lu, Xi; Kim, Suenne; Gao, Yang; Kim, Hoe-Joon; Somnath, Suhas; Polloni, Laura; Sordan, Roman; King, William P; Curtis, Jennifer E; Riedo, Elisa

2014-01-01

337

Parallel Programming Workshop  

NSDL National Science Digital Library

This is an online course for parallel programming. Topics include MPI basics, point-to-point communication, derived datatypes, virtual topologies, collective communication, parallel I/O, and performance analysis and profiling. Other languages will be discussed such as OpenMP and High Performance Fortran (HPF). A Computational Fluid Dynamics section includes flux functions, Riemann solver, Euler equations, and Navier-Stokes equations.

338

Parallel discrete event simulation  

Microsoft Academic Search

Parallel discrete event simulation (PDES), sometimes called distributed simulation, refers to the execution of a single discrete event simulation program on a parallel computer. PDES has attracted a considerable amount of interest in recent years. From a pragmatic standpoint, this interest arises from the fact that large simulations in engineering, computer science, economics, and military applications, to mention a few,

Richard M. Fujimoto

1990-01-01

339

Conscious Parallelism Revisited  

Microsoft Academic Search

Conscious parallelism, sometimes called tacit collusion, occurs where firms adopt their business practices based on what other firms are doing, rather than competing for customers. The most obvious manifestation occurs where prices across companies in an industry not only become suspiciously similar, but also change rapidly in strikingly parallel ways. Suggested examples are legion and varied: airline tickets, gasoline, cellular

Reza Dibadj

2010-01-01

340

A local stability supported parallel distributed constraint optimization algorithm.  

PubMed

This paper presents a new distributed constraint optimization algorithm called LSPA, which can be used to solve large scale distributed constraint optimization problem (DCOP). Different from the access of local information in the existing algorithms, a new criterion called local stability is defined and used to evaluate which is the next agent whose value needs to be changed. The propose of local stability opens a new research direction of refining initial solution by finding key agents which can seriously effect global solution once they modify assignments. In addition, the construction of initial solution could be received more quickly without repeated assignment and conflict. In order to execute parallel search, LSPA finds final solution by constantly computing local stability of compatible agents. Experimental evaluation shows that LSPA outperforms some of the state-of-the-art incomplete distributed constraint optimization algorithms, guaranteeing better solutions received within ideal time. PMID:25105166

Peibo, Duan; Changsheng, Zhang; Bin, Zhang

2014-01-01

341

A Local Stability Supported Parallel Distributed Constraint Optimization Algorithm  

PubMed Central

This paper presents a new distributed constraint optimization algorithm called LSPA, which can be used to solve large scale distributed constraint optimization problem (DCOP). Different from the access of local information in the existing algorithms, a new criterion called local stability is defined and used to evaluate which is the next agent whose value needs to be changed. The propose of local stability opens a new research direction of refining initial solution by finding key agents which can seriously effect global solution once they modify assignments. In addition, the construction of initial solution could be received more quickly without repeated assignment and conflict. In order to execute parallel search, LSPA finds final solution by constantly computing local stability of compatible agents. Experimental evaluation shows that LSPA outperforms some of the state-of-the-art incomplete distributed constraint optimization algorithms, guaranteeing better solutions received within ideal time. PMID:25105166

Peibo, Duan; Changsheng, Zhang; Bin, Zhang

2014-01-01

342

Generalized zero-padding scheme for direct GPS P-code acquisition  

Microsoft Academic Search

Because of the long period and high chip rate of GPS P-code, direct acquisition is challenging. In the letter, the widely used zero-padding scheme (ZPS) for direct GPS P-code acquisition is generalized to investigate the effects of the ZPS on detection performance, parallel searching capability, and mean acquisition time. It is shown that, by adjusting the zeros padded to received

Hong Li; Mingquan Lu; Xiaowei Cui; Zhenming Feng

2009-01-01

343

Parallel processing of numerical transport algorithms  

SciTech Connect

The multigroup, discrete ordinates representation for the linear transport equation enjoys widespread computational use and popularity. Serial solution schemes and numerical algorithms developed over the years provide a timely framework for parallel extension. On the Denelcor HEP, we investigate the parallel structure and extension of a number of standard S/sub n/ approaches. Concurrent inner sweeps, coupled acceleration techniques, synchronized inner-outer loops, and chaotic iteration are described, and results of computations are contrasted. The multigroup representation and serial iteration methods are also detailed. The basic iterative S/sub n/ method lends itself to parallel tasking, portably affording an effective medium for performing transport calculations on future architectures. This analysis represents a first attempt to extend serial S/sub n/ algorithms to parallel environments and provides good baseline estimates on ease of parallel implementation, relative algorithm efficiency, comparative speedup, and some future directions. We find basic inner-outer and chaotic iteration strategies both easily support comparably high degrees of parallelism. Both accommodate parallel rebalance and diffusion acceleration and appear as robust and viable parallel techniques for S/sub n/ production work.

Wienke, B.R.; Hiromoto, R.E.

1984-01-01

344

Bilingual parallel programming  

SciTech Connect

Numerous experiments have demonstrated that computationally intensive algorithms support adequate parallelism to exploit the potential of large parallel machines. Yet successful parallel implementations of serious applications are rare. The limiting factor is clearly programming technology. None of the approaches to parallel programming that have been proposed to date -- whether parallelizing compilers, language extensions, or new concurrent languages -- seem to adequately address the central problems of portability, expressiveness, efficiency, and compatibility with existing software. In this paper, we advocate an alternative approach to parallel programming based on what we call bilingual programming. We present evidence that this approach provides and effective solution to parallel programming problems. The key idea in bilingual programming is to construct the upper levels of applications in a high-level language while coding selected low-level components in low-level languages. This approach permits the advantages of a high-level notation (expressiveness, elegance, conciseness) to be obtained without the cost in performance normally associated with high-level approaches. In addition, it provides a natural framework for reusing existing code.

Foster, I.; Overbeek, R.

1990-01-01

345

Parallel processing for scientific computations  

NASA Technical Reports Server (NTRS)

The main contribution of the effort in the last two years is the introduction of the MOPPS system. After doing extensive literature search, we introduced the system which is described next. MOPPS employs a new solution to the problem of managing programs which solve scientific and engineering applications on a distributed processing environment. Autonomous computers cooperate efficiently in solving large scientific problems with this solution. MOPPS has the advantage of not assuming the presence of any particular network topology or configuration, computer architecture, or operating system. It imposes little overhead on network and processor resources while efficiently managing programs concurrently. The core of MOPPS is an intelligent program manager that builds a knowledge base of the execution performance of the parallel programs it is managing under various conditions. The manager applies this knowledge to improve the performance of future runs. The program manager learns from experience.

Alkhatib, Hasan S.

1991-01-01

346

Strategies of information search in causal analysis  

Microsoft Academic Search

Five experiments investigated the relative prevalence of three search patterns that individuals may use in explaining events\\u000a with multiple possible causes: (1) parallel searchpursue information about all possible causes before making any causal judgments,\\u000a (2) serial searchclarify the role of one cause before considering any others, (3) truncated searchclarify the role of one\\u000a cause without proceeding to consider other causes.

Harriet Shaklee; Baruch Fischhoff

1982-01-01

347

Series/Parallel Batteries  

NSDL National Science Digital Library

It is important for students to understand how resistors, capacitors, and batteries combine in series and parallel. The combination of batteries has a lot of practical applications in science competitions. This lab also reinforces how to use a voltmeter t

Horton, Michael

2009-05-30

348

Parallel Plate Antenna.  

National Technical Information Service (NTIS)

The invention as disclosed is a parallel plate antenna having a number of stacked horizontal plates and two vertical plates. Alternating ones of the horizontal plates are electrically coupled to one vertical plate such that the horizontal plates coupled t...

D. F. Rivera

2009-01-01

349

Parallels with nature  

NASA Astrophysics Data System (ADS)

Adam Nelson and Stuart Warriner, from the University of Leeds, talk with Nature Chemistry about their work to develop viable synthetic strategies for preparing new chemical structures in parallel with the identification of desirable biological activity.

2014-10-01

350

Calculational parallel programming: parallel programming with homomorphism and mapreduce  

Microsoft Academic Search

Parallel skeletons are designed to encourage programmers to build parallel programs from ready-made components for which efficient implementations are known to exist, making both parallel programming and parallelization process simpler. Homomorphism and mapReduce are two known parallel skeletons. Homomorphism, widely studied in the program calculation community for more than twenty years, ideally suits the divide-and-conquer parallel computation paradigm over lists,

Zhenjiang Hu; K. Emoto; Z. Hu; K. Kakehi; K. Matsuzaki; M. Takeichi

2010-01-01

351

Scalable parallel communications  

NASA Technical Reports Server (NTRS)

Coarse-grain parallelism in networking (that is, the use of multiple protocol processors running replicated software sending over several physical channels) can be used to provide gigabit communications for a single application. Since parallel network performance is highly dependent on real issues such as hardware properties (e.g., memory speeds and cache hit rates), operating system overhead (e.g., interrupt handling), and protocol performance (e.g., effect of timeouts), we have performed detailed simulations studies of both a bus-based multiprocessor workstation node (based on the Sun Galaxy MP multiprocessor) and a distributed-memory parallel computer node (based on the Touchstone DELTA) to evaluate the behavior of coarse-grain parallelism. Our results indicate: (1) coarse-grain parallelism can deliver multiple 100 Mbps with currently available hardware platforms and existing networking protocols (such as Transmission Control Protocol/Internet Protocol (TCP/IP) and parallel Fiber Distributed Data Interface (FDDI) rings); (2) scale-up is near linear in n, the number of protocol processors, and channels (for small n and up to a few hundred Mbps); and (3) since these results are based on existing hardware without specialized devices (except perhaps for some simple modifications of the FDDI boards), this is a low cost solution to providing multiple 100 Mbps on current machines. In addition, from both the performance analysis and the properties of these architectures, we conclude: (1) multiple processors providing identical services and the use of space division multiplexing for the physical channels can provide better reliability than monolithic approaches (it also provides graceful degradation and low-cost load balancing); (2) coarse-grain parallelism supports running several transport protocols in parallel to provide different types of service (for example, one TCP handles small messages for many users, other TCP's running in parallel provide high bandwidth service to a single application); and (3) coarse grain parallelism will be able to incorporate many future improvements from related work (e.g., reduced data movement, fast TCP, fine-grain parallelism) also with near linear speed-ups.

Maly, K.; Khanna, S.; Overstreet, C. M.; Mukkamala, R.; Zubair, M.; Sekhar, Y. S.; Foudriat, E. C.

1992-01-01

352

Parallel image compression  

NASA Technical Reports Server (NTRS)

A parallel compression algorithm for the 16,384 processor MPP machine was developed. The serial version of the algorithm can be viewed as a combination of on-line dynamic lossless test compression techniques (which employ simple learning strategies) and vector quantization. These concepts are described. How these concepts are combined to form a new strategy for performing dynamic on-line lossy compression is discussed. Finally, the implementation of this algorithm in a massively parallel fashion on the MPP is discussed.

Reif, John H.

1987-01-01

353

Solving the economic dispatch problem with an integrated parallel genetic algorithm  

Microsoft Academic Search

The application of an integrated parallel genetic algorithm (GA) incorporating simulated annealing (SA) and tabu search (TS) techniques to the economic dispatch (ED) problem is reported in this paper. The integrated genetic algorithm is implemented in both parallel and cluster structures. The parallel computing platform is based on a network of interconnected personal computers (PC) using TCP\\/IP socket communication facilities.

C. C. Fung; S. Y. Chow; K. P. Wong

2000-01-01

354

Search IQ  

NSDL National Science Digital Library

Yet another in a large collection of sites on search engines, Search IQ is notable for two features. First, its collection of search engine reviews is rather extensive, covering far more than the usual dozen or so listed at most search engine review sites. Although rankings and full reviews are offered for only 17 engines, the individual and meta-search engine listings offer at least a sentence or two on many more. The other key section of the site is a fairly large directory of specialized search engines, organized by subject. Additional resources at the site include daily tips, tutorials and guides, and a listing of new search engines.

355

Parallelization for geophysical waveform analysis  

E-print Network

&M University to aid the parallel programmer by providing standard implementations of common parallel programming tasks. Our research involves using STAPL to apply parallel methods to a problem that has already been solved sequentially: Seismic ray tracing...

Kurth, Derek Edward

2013-02-22

356

Code Parallelization with CAPO: A User Manual  

NASA Technical Reports Server (NTRS)

A software tool has been developed to assist the parallelization of scientific codes. This tool, CAPO, extends an existing parallelization toolkit, CAPTools developed at the University of Greenwich, to generate OpenMP parallel codes for shared memory architectures. This is an interactive toolkit to transform a serial Fortran application code to an equivalent parallel version of the software - in a small fraction of the time normally required for a manual parallelization. We first discuss the way in which loop types are categorized and how efficient OpenMP directives can be defined and inserted into the existing code using the in-depth interprocedural analysis. The use of the toolkit on a number of application codes ranging from benchmark to real-world application codes is presented. This will demonstrate the great potential of using the toolkit to quickly parallelize serial programs as well as the good performance achievable on a large number of toolkit to quickly parallelize serial programs as well as the good performance achievable on a large number of processors. The second part of the document gives references to the parameters and the graphic user interface implemented in the toolkit. Finally a set of tutorials is included for hands-on experiences with this toolkit.

Jin, Hao-Qiang; Frumkin, Michael; Yan, Jerry; Biegel, Bryan (Technical Monitor)

2001-01-01

357

Object boundaries influence toddlers' performance in a search task.  

PubMed

Previous research has shown that young children have difficulty searching for a hidden object whose location depends on the position of a partly visible physical barrier. Across four experiments, we tested whether children's search errors are affected by two variables that influence adults' object-directed attention: object boundaries and proximity relations. Toddlers searched for a car that rolled down a ramp behind an occluding panel and stopped on contact with a barrier. The car's location on each trial depended on the placement of the barrier behind one of two doors in the panel. In Experiment 1, when a part of the car (a pompom on an antenna) was visible at the same distance from the object as the barrier wall in past research, search performance was above chance but below ceiling. In Experiments 2 and 3, when the visible part was close to the hidden body of the car and could be seen through one of two windows in the doors of the occluding panel, performance was near ceiling. In Experiment 4, when only the barrier was visible through one of the same windows, performance was at chance. Toddlers' search for a hidden object therefore is affected by the proximity of a visible part of the object, though not by the proximity of a separate visible landmark. These findings suggest a parallel between the object representations of young children and those of adults, whose attention is directed to objects and spreads in a gradient-like fashion within an object. PMID:16445399

Shutts, Kristin; Keen, Rachel; Spelke, Elizabeth S

2006-01-01

358

Sublattice parallel replica dynamics.  

PubMed

Exascale computing presents a challenge for the scientific community as new algorithms must be developed to take full advantage of the new computing paradigm. Atomistic simulation methods that offer full fidelity to the underlying potential, i.e., molecular dynamics (MD) and parallel replica dynamics, fail to use the whole machine speedup, leaving a region in time and sample size space that is unattainable with current algorithms. In this paper, we present an extension of the parallel replica dynamics algorithm [A. F. Voter, Phys. Rev. B 57, R13985 (1998)] by combining it with the synchronous sublattice approach of Shim and Amar [ and , Phys. Rev. B 71, 125432 (2005)], thereby exploiting event locality to improve the algorithm scalability. This algorithm is based on a domain decomposition in which events happen independently in different regions in the sample. We develop an analytical expression for the speedup given by this sublattice parallel replica dynamics algorithm and compare it with parallel MD and traditional parallel replica dynamics. We demonstrate how this algorithm, which introduces a slight additional approximation of event locality, enables the study of physical systems unreachable with traditional methodologies and promises to better utilize the resources of current high performance and future exascale computers. PMID:25019913

Martnez, Enrique; Uberuaga, Blas P; Voter, Arthur F

2014-06-01

359

Sublattice parallel replica dynamics  

NASA Astrophysics Data System (ADS)

Exascale computing presents a challenge for the scientific community as new algorithms must be developed to take full advantage of the new computing paradigm. Atomistic simulation methods that offer full fidelity to the underlying potential, i.e., molecular dynamics (MD) and parallel replica dynamics, fail to use the whole machine speedup, leaving a region in time and sample size space that is unattainable with current algorithms. In this paper, we present an extension of the parallel replica dynamics algorithm [A. F. Voter, Phys. Rev. B 57, R13985 (1998), 10.1103/PhysRevB.57.R13985] by combining it with the synchronous sublattice approach of Shim and Amar [Y. Shim and J. G. Amar, Phys. Rev. B 71, 125432 (2005), 10.1103/PhysRevB.71.125432], thereby exploiting event locality to improve the algorithm scalability. This algorithm is based on a domain decomposition in which events happen independently in different regions in the sample. We develop an analytical expression for the speedup given by this sublattice parallel replica dynamics algorithm and compare it with parallel MD and traditional parallel replica dynamics. We demonstrate how this algorithm, which introduces a slight additional approximation of event locality, enables the study of physical systems unreachable with traditional methodologies and promises to better utilize the resources of current high performance and future exascale computers.

Martnez, Enrique; Uberuaga, Blas P.; Voter, Arthur F.

2014-06-01

360

DPL : Data Parallel Library Manual Technical Report: UNC-TR93-064  

E-print Network

-parallel programs written in the Proteus programming language yield parallel execution on a variety of different parallel architectures. The Data Parallel Library (DPL) directly supports Proteus by supplying a vital link as an executable target notation for transformations of Proteus programs. To meet this goal the library must

North Carolina at Chapel Hill, University of

361

Parallel FFT & Isoefficiency 1 The Fast Fourier Transform in Parallel  

E-print Network

Parallel FFT & Isoefficiency 1 The Fast Fourier Transform in Parallel the Fastest Fourier Transform / 25 #12;Parallel FFT & Isoefficiency 1 The Fast Fourier Transform in Parallel the Fastest Fourier & Isoefficiency L-14 14 February 2014 2 / 25 #12;the Discrete Fourier Transform (DFT) A periodic function f(t) can

Verschelde, Jan

362

Simulating Billion-Task Parallel Programs  

SciTech Connect

In simulating large parallel systems, bottom-up approaches exercise detailed hardware models with effects from simplified software models or traces, whereas top-down approaches evaluate the timing and functionality of detailed software models over coarse hardware models. Here, we focus on the top-down approach and significantly advance the scale of the simulated parallel programs. Via the direct execution technique combined with parallel discrete event simulation, we stretch the limits of the top-down approach by simulating message passing interface (MPI) programs with millions of tasks. Using a timing-validated benchmark application, a proof-of-concept scaling level is achieved to over 0.22 billion virtual MPI processes on 216,000 cores of a Cray XT5 supercomputer, representing one of the largest direct execution simulations to date, combined with a multiplexing ratio of 1024 simulated tasks per real task.

Perumalla, Kalyan S [ORNL] [ORNL; Park, Alfred J [ORNL] [ORNL

2014-01-01

363

Analysis of parallelism in logic programs. (Volumes I and II)  

SciTech Connect

The research reported in this thesis characterizes and explores various aspects of parallelism in the framework of logic programming. Specifically, communication, process, and resource control are analyzed with respect to parallel execution of logic programs. A computational model for AND/OR parallel execution of logic programs is introduced. The computational model is shown to support both old and new communication paradigms for the parallel interpretation of logic programs. The primitives that comprise the model are used to synthesize two parallel interpreters: Disjunctive System (DS) interpreters and Intelligent Channel Interpreters. Also, investigated are several candidate control constructs for literal sequencing in terms of their efficiency, difficulty of implementation, and closeness to the spirit of logic programming. Finally, parallelism in logic programs with respect to an efficient implementation on a multiprocessor is investigated. Three methods for mapping the execution of a shared memory parallel interpreter to a multiprocessor are described and analyzed. Since searching and intersecting (joining) are key components in many logic programming systems, optimal parallel algorithms for searching and intersection are developed.

Kasif, S.

1984-01-01

364

Geographical and Topographical Atlas accompanying the report of the Geological Exploration of the Fortieth Parallel, made by authority of the Hornorable Secretary of War, under the direction of Brig. and Bvt. Major General A. A. Humphreys, Chief of Engineers  

USGS Publications Warehouse

Contains a title, legend, and 11 folio maps in the folio. Contains a topographic (shaded) map of Cordilleran region, limiting meridians 104 and 124; limiting parallels 29 and 50. Scale, 60 miles to the inch. Also contains four geologic and four topographic (shaded) maps, on scale of 4 miles to the inch, of the following areas: Sheet I. Longitude, 104 30'-107 37'; latitude, 40 20'-41 54'. Sheet II. Longitude, 107 37'-110 43'; latitude, 40 16'-41 50'. Sheet III. Longitude, 110 43'-113 50'; latitude, 40 13'-41 46'. Sheet IV. Longitude, 113 50'-116 56'; latitude, 39 55'-41 29'.

King, Clarence; Lithography by Bien, Julius

1876-01-01

365

Massively parallel processor  

NASA Technical Reports Server (NTRS)

A brief description is given of the Massively Parallel Processor (MPP). Major applications of the MPP are in the area of image processing (where the operands are often very small integers) from very high spatial resolution passive image sensors, signal processing of radar data, and numerical modeling simulations of climate. The system can be programmed in assembly language or a high level language. Information on background, status, architecture, programming, hardware reliability, applications, and the MPP's development as a national resource for parallel algorithm research are presented in outline form.

1985-01-01

366

Experimental search of parametric X-ray radiation in a silicon crystal at a small angle near the velocity direction of relativistic electrons  

NASA Astrophysics Data System (ADS)

At the Tomsk synchrotron measurements of X-ray yield for the energies ?=29-53 keV emitted in the forward direction from a perfect silicon crystal bombarded by 500-MeV relativistic electrons have been carried out. The contribution of parametric X-ray radiation (PXR) at a small angle near the velocity direction of electrons has not been observed. The possible maximum value of this radiation is smaller than 2% of the total intensity of bremsstrahlung and transition radiation.

Kalinin, B. N.; Naumenko, G. A.; Padalko, D. V.; Potylitsyn, A. P.; Vnukov, I. E.

2001-01-01

367

Control of parallel manipulators using force feedback  

NASA Technical Reports Server (NTRS)

Two control schemes are compared for parallel robotic mechanisms actuated by hydraulic cylinders. One scheme, the 'rate based scheme', uses the position and rate information only for feedback. The second scheme, the 'force based scheme' feeds back the force information also. The force control scheme is shown to improve the response over the rate control one. It is a simple constant gain control scheme better suited to parallel mechanisms. The force control scheme can be easily modified for the dynamic forces on the end effector. This paper presents the results of a computer simulation of both the rate and force control schemes. The gains in the force based scheme can be individually adjusted in all three directions, whereas the adjustment in just one direction of the rate based scheme directly affects the other two directions.

Nanua, Prabjot

1994-01-01

368

Confidential Searches.  

ERIC Educational Resources Information Center

Will the stealth superintendent hunt in Cincinnati become tomorrow's standard approach? Search consultants and superintendents offer their views on how far confidentiality should go. Also includes a search firm's process for shielding identities and a confidentiality pledge. (MLF)

Kenney, Linda Chion

2003-01-01

369

Declarative Parallel Programming for GPUs  

E-print Network

, Arun CHAUHAN,Andrew LUMSDAINE Indiana University, Bloomington, USA ParCo 2011 September 1, 2011 #12;Arun Chauhan, Declarative parallel programming for GPUs, ParCo 2011 Parallelism Mainstream Parallelism nets Focus of today's Parallel Programming Models Courtesy:Vivek Sarkar, Rice University #12;Arun

Chauhan, Arun

370

Literature Searches  

NSDL National Science Digital Library

This presentation outlines the importance of and best practices for literature searches on research projects. It includes suggestions for search techniques, rubrics for evaluating sources, and resources to help with the search process. This presentation was developed for a physics senior projects class.

Chottiner, Gary

2010-04-14

371

Partition search  

SciTech Connect

We introduce a new form of game search called partition search that incorporates dependency analysis, allowing substantial reductions in the portion of the tree that needs to be expanded. Both theoretical results and experimental data are presented. For the game of bridge, partition search provides approximately as much of an improvement over existing methods as {alpha}-{beta} pruning provides over minimax.

Ginsberg, M.L. [CIRL, Eugene, OR (United States)

1996-12-31

372

Parallel Seismic Ray Tracing  

E-print Network

of the method while others are intended to be representative of basic geological features such as salt domes. We also present a theoretical model to understand the performance of the pWFC algorithm. We evaluate the performance of the proposed parallel...

Jain, Tarun K

2013-12-09

373

Parallel programming with PCN  

SciTech Connect

PCN is a system for developing and executing parallel programs. It comprises a high-level programming language, tools for developing and debugging programs in this language, and interfaces to Fortran and Cthat allow the reuse of existing code in multilingual parallel programs. Programs developed using PCN are portable across many different workstations, networks, and parallel computers. This document provides all the information required to develop parallel programs with the PCN programming system. It includes both tutorial and reference material. It also presents the basic concepts that underlie PCN, particularly where these are likely to be unfamiliar to the reader, and provides pointers to other documentation on the PCN language, programming techniques, and tools. PCN is in the public domain. The latest version of both the software and this manual can be obtained by anonymous ftp from Argonne National Laboratory in the directory pub/pcn at info.mcs. ani.gov (cf. Appendix A). This version of this document describes PCN version 2.0, a major revision of the PCN programming system. It supersedes earlier versions of this report.

Foster, I.; Tuecke, S.

1993-01-01

374

High performance parallel architectures  

SciTech Connect

In this paper the author describes current high performance parallel computer architectures. A taxonomy is presented to show computer architecture from the user programmer's point-of-view. The effects of the taxonomy upon the programming model are described. Some current architectures are described with respect to the taxonomy. Finally, some predictions about future systems are presented. 5 refs., 1 fig.

Anderson, R.E. (Lawrence Livermore National Lab., CA (USA))

1989-09-01

375

Parallel Circuits Lab  

NSDL National Science Digital Library

This in-class lab exercise will give students a familiarity with basic series and parallel circuits as well as measuring voltage, current and resistance. The worksheet provided leads students through the experiment step by step. Spaces for student measurements and conclusions are provided on the sheet. This document may be downloaded in PDF file format.

2012-05-04

376

Optimizing parallel reduction operations  

SciTech Connect

A parallel program consists of sets of concurrent and sequential tasks. Often, a reduction (such as array sum) sequentially combines values produced by a parallel computation. Because reductions occur so frequently in otherwise parallel programs, they are good candidates for optimization. Since reductions may introduce dependencies, most languages separate computation and reduction. The Sisal functional language is unique in that reduction is a natural consequence of loop expressions; the parallelism is implicit in the language. Unfortunately, the original language supports only seven reduction operations. To generalize these expressions, the Sisal 90 definition adds user-defined reductions at the language level. Applicable optimizations depend upon the mathematical properties of the reduction. Compilation and execution speed, synchronization overhead, memory use and maximum size influence the final implementation. This paper (1) Defines reduction syntax and compares with traditional concurrent methods; (2) Defines classes of reduction operations; (3) Develops analysis of classes for optimized concurrency; (4) Incorporates reductions into Sisal 1.2 and Sisal 90; (5) Evaluates performance and size of the implementations.

Denton, S.M.

1995-06-01

377

Parallelizing MATLAB Arun Chauhan  

E-print Network

Parallelizing MATLAB Arun Chauhan Indiana University ParaM Supercomputing, OSC booth, 2004-11-10 #12;The Performance Gap ParaM, Arun Chauhan, Indiana University Supercomputing, OSC booth, 2004-11-10 #12;MATLAB Example function mcc demo x = 1; y = x / 10; z = x * 20; r = y + z; ParaM, Arun Chauhan

Chauhan, Arun

378

Parallel Consensual Neural Networks  

Microsoft Academic Search

Optimized combination, regularization, and pruning is proposed for the Parallel Consensual Neural Networks (PC- NNs) which is a neural network architecture based on the consensus of a collection of stage neural networks trained on the same input data with dieren t representations. Here, a regularization scheme is presented for the PCNN and in training a regularized cost function is minimized.

J. A. Benediktsson; J. Larsen; J. R. Sveinsson; L. K. Hansen

379

Massively parallel processor computer  

NASA Technical Reports Server (NTRS)

An apparatus for processing multidimensional data with strong spatial characteristics, such as raw image data, characterized by a large number of parallel data streams in an ordered array is described. It comprises a large number (e.g., 16,384 in a 128 x 128 array) of parallel processing elements operating simultaneously and independently on single bit slices of a corresponding array of incoming data streams under control of a single set of instructions. Each of the processing elements comprises a bidirectional data bus in communication with a register for storing single bit slices together with a random access memory unit and associated circuitry, including a binary counter/shift register device, for performing logical and arithmetical computations on the bit slices, and an I/O unit for interfacing the bidirectional data bus with the data stream source. The massively parallel processor architecture enables very high speed processing of large amounts of ordered parallel data, including spatial translation by shifting or sliding of bits vertically or horizontally to neighboring processing elements.

Fung, L. W. (inventor)

1983-01-01

380

Parallel Traveling Salesman Problem  

NSDL National Science Digital Library

The traveling salesman problem is a classic optimization problem in which one seeks to minimize the path taken by a salesman in traveling between N cities, where the salesman stops at each city one and only one time, never retracing his/her route. This implementation is designed to run on UNIX systems with X-Windows, and includes parallelization using MPI.

Joiner, David; Hassinger, Jonathan

381

Parallelism and evolutionary algorithms  

Microsoft Academic Search

This paper contains a modern vision of the paral- lelization techniques used for evolutionary algorithms (EAs). The work is motivated by two fundamental facts: first, the different families of EAs have naturally converged in the last decade while parallel EAs (PEAs) seem still to lack unified studies, and second, there is a large number of improvements in these algorithms and

Enrique Alba; Marco Tomassini

2002-01-01

382

Coping with Anomalies in Parallel Branch-and-Bound Algorithms  

Microsoft Academic Search

A general technique that can be used to solve a wide variety of discrete optimization problems is the branch-and-bound algorithm. The authors have adapted and extended branch-and-bound algorithms for parallel processing. The computational efficiency of these algorithms depends on the allowance function, the data structure, and the search strategies. Anomalies owing to parallelism may occur. In this correspondence, anomalies of

Guo-jie Li; Benjamin W. Wah

1986-01-01

383

Application of a parallel DSMC method to hypersonic rarefied flows  

SciTech Connect

This paper describes a method for doing direct simulation Monte Carlo (DSMC) calculations using parallel processing and presents some results of applying the method to several hypersonic, rarefied flow problems. The performance and efficiency of the parallel method are discussed. The applications described are the flow in a channel and the flow about a flat plate at incidence. The results show significant advantages of parallel processing over conventional scalar processing and demonstrate the scalability of the method to large problems. 8 refs.

Wilmoth, R.G. (NASA, Langley Research Center, Hampton, VA (USA))

1991-01-01

384

Monte-Carlo Game Tree Search  

Microsoft Academic Search

Abstract Introducing the original ideas of using Monte-Carlo simulation in computer Go. Adding new ideas to pure Monte-Carlo approach for computer Go. Progressive pruning All moves as first heuristic Temperature Simulated annealing Depth-2 tree search Parallel Monte-Carlo tree search Conclusion: With the ever-increasing power of computers, we can add more knowl- edge to the

Tsan-sheng Hsu

385

Parallel partitioned-inverse sparse matrix solutions  

SciTech Connect

The partitioned inverse method has been demonstrated to be quite effective for parallel sparse matrix solutions on massively parallel machines. Though experiments on CM-2 have illustrated the advantage of using partitions, Intel iPSC/860 multiprocessor only favors fewer and denser partitions, particularly in the case of extremely sparse matrices. Different decomposition and communication algorithms are investigated here on the iPSC/860 to improve the performance. The decomposition is done in an interleave fashion in two different directions (row-wise and column-wise). The need for synchronization due to the interchange of intermediate solution vectors makes load balancing an important factor in obtaining an optimum performance.

Dag, H.; Yasar, O.; Alvarado, F. [Univ. of Wisconsin, Madison, WI (United States)

1993-12-31

386

Applying sample weighting methods to genetic parallel programming  

Microsoft Academic Search

We investigate the sample weighting effect on genetic parallel programming (GPP). GPP evolves parallel programs to solve the training samples in a training set. Usually, the samples are captured directly from a real-world system. The distribution of samples in a training set can be extremely biased. Standard GPP assigns equal weights to all samples. It slows down evolution because crowded

Sin Man Cheang; Kin Hong Lee; Kwong Sak Leung

2003-01-01

387

IPSJ SIG Technical Report Automatic parallelization with OSCAR API Analyzer  

E-print Network

IPSJ SIG Technical Report Automatic parallelization with OSCAR API Analyzer: a cross have devel- oped the OSCAR API Analyzer. It allows programs automatically parallelized by the OSCAR compiler with OSCAR API directives to target many different platforms using just sequential compilers. We

Kasahara, Hironori

388

Parallel plate THz transmitter S. Coleman and D. Grischkowskya)  

E-print Network

Parallel plate THz transmitter S. Coleman and D. Grischkowskya) School of Electrical and Computer December 2003 A THz transmitter that directly excites the guided wave modes of a dielectric filled parallel-domain THz signal. The device yields significant signal amplitudes with varying output spectra

389

Integrated Task And Data Parallel Programming: Language Design  

NASA Technical Reports Server (NTRS)

his research investigates the combination of task and data parallel language constructs within a single programming language. There are an number of applications that exhibit properties which would be well served by such an integrated language. Examples include global climate models, aircraft design problems, and multidisciplinary design optimization problems. Our approach incorporates data parallel language constructs into an existing, object oriented, task parallel language. The language will support creation and manipulation of parallel classes and objects of both types (task parallel and data parallel). Ultimately, the language will allow data parallel and task parallel classes to be used either as building blocks or managers of parallel objects of either type, thus allowing the development of single and multi-paradigm parallel applications. 1995 Research Accomplishments In February I presented a paper at Frontiers '95 describing the design of the data parallel language subset. During the spring I wrote and defended my dissertation proposal. Since that time I have developed a runtime model for the language subset. I have begun implementing the model and hand-coding simple examples which demonstrate the language subset. I have identified an astrophysical fluid flow application which will validate the data parallel language subset. 1996 Research Agenda Milestones for the coming year include implementing a significant portion of the data parallel language subset over the Legion system. Using simple hand-coded methods, I plan to demonstrate (1) concurrent task and data parallel objects and (2) task parallel objects managing both task and data parallel objects. My next steps will focus on constructing a compiler and implementing the fluid flow application with the language. Concurrently, I will conduct a search for a real-world application exhibiting both task and data parallelism within the same program m. Additional 1995 Activities During the fall I collaborated with Andrew Grimshaw and Adam Ferrari to write a book chapter which will be included in Parallel Processing in C++ edited by Gregory Wilson. I also finished two courses, Compilers and Advanced Compilers, in 1995. These courses complete my class requirements at the University of Virginia. I have only my dissertation research and defense to complete.

Grimshaw, Andrew S.; West, Emily A.

1998-01-01

390

SMM observations of gamma-ray transients. 3: A search for a broadened, redshifted positron annihilation line from the direction of the Galactic center  

NASA Technical Reports Server (NTRS)

We have searched for 1980-1988 Solar Maximum Mission gamma-ray spectrometer data for transient emission on timescales from hours to approximately 12 days of broad gamma-ray lines at energies approximately 400 keV, which were reported by the High Energy Astronomy Observatory (HEAO) 1 and SIGMA experiments from two sources lying toward the Galactic center. The lines have been interpreted as the product of the annihilation of positrons in pair plasmas surrounding the black hole candidate 1E 1740.7-2942 and the X-ray binary 1H 1822-371. Our results from a combined exposure of approximately 1.5 x 10(exp 7)s provide no convincing evidence for transient emission of this line on any timescale between approximately 9 hr and approximately 1 yr. Our 3 sigma upper limits on the line flux during approximately 12 day intervals are characteristically 4.8 x 10(exp -3) photon/sq cm/s, while for approximately 1 day intervals our 3 sigma upper limits are characteristically 4.9 x 10(exp -3) photon/sq cm/s. These results imply a duty cycle of less than 1.3% for the transient line measured from 1H 1822-371 during a approximately 3 week interval in 1977 by HEAO 1, and a duty cycle of less than or = 0.8% for the transient line detected in 1990 and 1992 from 1E 1740.7-2942 on approximately 1 day timescales by SIGMA.

Harris, Michael J.; Share, Gerald H.; Leising, Mark D.

1994-01-01

391

Parallel Consensual Neural Networks  

NASA Technical Reports Server (NTRS)

A new neural network architecture is proposed and applied in classification of remote sensing/geographic data from multiple sources. The new architecture is called the parallel consensual neural network and its relation to hierarchical and ensemble neural networks is discussed. The parallel consensual neural network architecture is based on statistical consensus theory. The input data are transformed several times and the different transformed data are applied as if they were independent inputs and are classified using stage neural networks. Finally, the outputs from the stage networks are then weighted and combined to make a decision. Experimental results based on remote sensing data and geographic data are given. The performance of the consensual neural network architecture is compared to that of a two-layer (one hidden layer) conjugate-gradient backpropagation neural network. The results with the proposed neural network architecture compare favorably in terms of classification accuracy to the backpropagation method.

Benediktsson, J. A.; Sveinsson, J. R.; Ersoy, O. K.; Swain, P. H.

1993-01-01

392

Parallel Transports in Webs  

E-print Network

For connected reductive linear algebraic structure groups it is proven that every web is holonomically isolated. The possible tuples of parallel transports in a web form a Lie subgroup of the corresponding power of the structure group. This Lie subgroup is explicitly calculated and turns out to be independent of the chosen local trivializations. Moreover, explicit necessary and sufficient criteria for the holonomical independence of webs are derived. The results above can even be sharpened: Given an arbitrary neighbourhood of the base points of a web, then this neighbourhood contains some segments of the web whose parameter intervals coincide, but do not include 0 (that corresponds to the base points of the web), and whose parallel transports already form the same Lie subgroup as those of the full web do.

Christian Fleischhack

2003-03-31

393

Parallel multilevel preconditioners  

SciTech Connect

In this paper, we shall report on some techniques for the development of preconditioners for the discrete systems which arise in the approximation of solutions to elliptic boundary value problems. Here we shall only state the resulting theorems. It has been demonstrated that preconditioned iteration techniques often lead to the most computationally effective algorithms for the solution of the large algebraic systems corresponding to boundary value problems in two and three dimensional Euclidean space. The use of preconditioned iteration will become even more important on computers with parallel architecture. This paper discusses an approach for developing completely parallel multilevel preconditioners. In order to illustrate the resulting algorithms, we shall describe the simplest application of the technique to a model elliptic problem.

Bramble, J.H.; Pasciak, J.E.; Xu, Jinchao.

1989-01-01

394

Parallelization: Infectious Disease  

NSDL National Science Digital Library

Epidemiology is the study of infectious disease. Infectious diseases are said to be "contagious" among people if they are transmittable from one person to another. Epidemiologists can use models to assist them in predicting the behavior of infectious diseases. This module will develop a simple agent-based infectious disease model, develop a parallel algorithm based on the model, provide a coded implementation for the algorithm, and explore the scaling of the coded implementation on high performance cluster resources.

Weeden, Aaron

395

Fast wideband search for spurious responses  

NASA Astrophysics Data System (ADS)

A technique for quickly searching frequencies in a signal path to find and measure low-level spurs is described. It couples a wideband tuned receiver with a tuned digital, parallel filter bank analyzer to greatly reduce spur testing times. The receiver is step-tuned across the region of frequencies to be searched, and at each step the filter bank is step-tuned across the IF output. An example system is described, and search time and sensitivity are discussed.

Cassidy, Kevin; Snell, Jay

1992-02-01

396

Visual rays are parallel.  

PubMed

We show that human observers using monocular viewing treat the pencil of 'visual rays' that diverges from the vantage point as experientally parallel. This oddity becomes very noticeable in the case of wide-angle presentations, where the angle subtended by a pair of visual rays may be as large as the angular size of the display. In our presentations such angles subtended over 100 deg. There are various ways to demonstrate the effect; in this study we measure the attitudes of pictorial objects that appear to be situated in mutually parallel attitudes in pictorial space. Our finding is that such objects appear parallel if they are similarly oriented with respect to the local visual rays. This leads to 'errors' in the judgment of mutual orientations of up to 100 deg. Although this appears to be the first quantitative study of the effect, we trace it to qualitative reports by Helmholtz (late 19th century) and Kepler (early 17th century) as well as speculation by early authors (AD 500). The effect has apparently been noticed by visual artists from the late middle ages to the present day. PMID:21125944

Koenderink, Jan; van Doorn, Andrea; de Ridder, Huib; Oomes, Stijn

2010-01-01

397

Parallel dichotomy algorithm for solving tridiagonal SLAEs  

E-print Network

A parallel algorithm for solving a series of matrix equations with a constant tridiagonal matrix and different right-hand sides is proposed and studied. The process of solving the problem is represented in two steps. The first preliminary step is fixing some rows of the inverse matrix of SLAEs. The second step consists in calculating solutions for all right-hand sides. For reducing the communication interactions, based on the formulated and proved main parallel sweep theorem, we propose an original algorithm for calculating share components of the solution vector. Theoretical estimates validating the efficiency of the approach for both the common- and distributed-memory supercomputers are obtained. Direct and iterative methods of solving a 2D Poisson equation, which include procedures of tridiagonal matrix inversion, are realized using the mpi technology. Results of computational experiments on a multicomputer demonstrate a high efficiency and scalability of the parallel sweep algorithm.

Terekhov, Andrew

2009-01-01

398

Parallel dichotomy algorithm for solving tridiagonal SLAEs  

E-print Network

A parallel algorithm for solving a series of matrix equations with a constant tridiagonal matrix and different right-hand sides is proposed and studied. The process of solving the problem is represented in two steps. The first preliminary step is fixing some rows of the inverse matrix of SLAEs. The second step consists in calculating solutions for all right-hand sides. For reducing the communication interactions, based on the formulated and proved main parallel sweep theorem, we propose an original algorithm for calculating share components of the solution vector. Theoretical estimates validating the efficiency of the approach for both the common- and distributed-memory supercomputers are obtained. Direct and iterative methods of solving a 2D Poisson equation, which include procedures of tridiagonal matrix inversion, are realized using the mpi technology. Results of computational experiments on a multicomputer demonstrate a high efficiency and scalability of the parallel sweep algorithm.

Andrew Terekhov

2009-01-19

399

Line-drawing algorithms for parallel machines  

NASA Technical Reports Server (NTRS)

The fact that conventional line-drawing algorithms, when applied directly on parallel machines, can lead to very inefficient codes is addressed. It is suggested that instead of modifying an existing algorithm for a parallel machine, a more efficient implementation can be produced by going back to the invariants in the definition. Popular line-drawing algorithms are compared with two alternatives; distance to a line (a point is on the line if sufficiently close to it) and intersection with a line (a point on the line if an intersection point). For massively parallel single-instruction-multiple-data (SIMD) machines (with thousands of processors and up), the alternatives provide viable line-drawing algorithms. Because of the pixel-per-processor mapping, their performance is independent of the line length and orientation.

Pang, Alex T.

1990-01-01

400

A Parallel Architecture perspective on language processing.  

PubMed

This article sketches the Parallel Architecture, an approach to the structure of grammar that contrasts with mainstream generative grammar (MGG) in that (a) it treats phonology, syntax, and semantics as independent generative components whose structures are linked by interface rules; (b) it uses a parallel constraint-based formalism that is nondirectional; (c) it treats words and rules alike as pieces of linguistic structure stored in long-term memory. In addition to the theoretical advantages offered by the Parallel Architecture, it lends itself to a direct interpretation in processing terms, in which pieces of structure stored in long-term memory are assembled in working memory, and alternative structures are in competition. The resulting model of processing is compared both with processing models derived from MGG and with lexically driven connectionist architectures. PMID:17045978

Jackendoff, Ray

2007-05-18

401

WIMP Dark Matter Limit-Direct Detection Data and Sensitivity Plots from the Cryogenic Dark Matter Search II and the University of California at Santa Barbara  

DOE Data Explorer

Expectations for non-baryonic dark matter are founded principally in Big Bang nucleosynthesis calculations, which indicate that the missing mass of the universe is not likely to be baryonic. The supersymmetric standard model (SUSY) offers a promising framework for expectations of particle species which could satisfy the observed properties of dark matter. WIMPs are the most likely SUSY candidate for a dark matter particle. The High Energy Physics Group at University of California, Santa Barbara, is part of the CDMSII Collaboration and have provided the Interactive Plotter for WIMP Dark Matter Limit-Direct Detection Data on their website. They invite other collaborations working on dark matter research to submit datasets and, as a result, have more than 150 data sets now available for use with the plotting tool. The published source of the data is provided with each data set.

402

Darwinian Evolution in Parallel Universes: A Parallel Genetic Algorithm for  

E-print Network

Darwinian Evolution in Parallel Universes: A Parallel Genetic Algorithm for Variable Selection Mu outcome of interest commonly arises in various industrial engineering applications. The genetic algorithm modification. Our idea is to run a number of GAs in parallel without allowing each GA to fully converge

Zhu, Mu

403

Hierarchical Parallelism in Finite Difference Analysis of Heat Conduction  

NASA Technical Reports Server (NTRS)

Based on the concept of hierarchical parallelism, this research effort resulted in highly efficient parallel solution strategies for very large scale heat conduction problems. Overall, the method of hierarchical parallelism involves the partitioning of thermal models into several substructured levels wherein an optimal balance into various associated bandwidths is achieved. The details are described in this report. Overall, the report is organized into two parts. Part 1 describes the parallel modelling methodology and associated multilevel direct, iterative and mixed solution schemes. Part 2 establishes both the formal and computational properties of the scheme.

Padovan, Joseph; Krishna, Lala; Gute, Douglas

1997-01-01

404

Parallel collective resonances in arrays of gold nanorods.  

PubMed

In this work we discuss the excitation of parallel collective resonances in arrays of gold nanoparticles. Parallel collective resonances result from the coupling of the nanoparticles localized surface plasmons with diffraction orders traveling in the direction parallel to the polarization vector. While they provide field enhancement and delocalization as the standard collective resonances, our results suggest that parallel resonances could exhibit greater tolerance to index asymmetry in the environment surrounding the arrays. The near- and far-field properties of these resonances are analyzed, both experimentally and numerically. PMID:24645987

Vitrey, Alan; Aigouy, Lionel; Prieto, Patricia; Garca-Martn, Jos Miguel; Gonzlez, Mara U

2014-04-01

405

Searching by rules: pigeons' (Columba livia) landmark-based search according to constant bearing or constant distance.  

PubMed

Pigeons (Columba livia) searched for a goal location defined by a constant relative spatial relationship to 2 landmark. For one group, landmark-to-goal bearings remained constant while distance varied. For another group landmark-to-goal distances remained constant while direction varied. Birds were trained with 4 interlandmark distances and then tested with 5 novel interlandmark distances. Overall error magnitude was similar across groups and was large than previously reported for Clark's nutcrackers (Nucifraga columbiana). During training, error magnitude increased with interlandmark distance for constant-bearing but not constant-distance birds. Both groups searched less accurately along the parallel to landmarks than along the perpendicular axis. Error magnitude increased with novel extrapolated interlandmark distances but not with novel interpolated distances. Results suggest modest geometric rule learning by pigeons. PMID:12856782

Spetch, Marcia L; Rust, Tiana B; Kamil, Alan C; Jones, Juli E

2003-06-01

406

Raging Search  

NSDL National Science Digital Library

Another search engine!! Another search engine? Yes, yet another Web search engine has come online, but this one isn't just business as usual. For one thing, there are no graphics, no banner ads, and no fancy portal features, so Raging Search loads very quickly. Another thing that makes it stand out is the ability to customize various parameters like the number of results displayed per page or the amount of detail returned for each result, and have those preferences "stick," so users need not reset them every time they enter the site. Also through this customization interface, users can select the languages of resources they want to search for (including support for various non-English character sets) and opt to include a "translated version" link along with each search result. And last, but certainly not least, all of the above runs atop an AltaVista search engine, consistently rated one of the best search tools on the Web, enhanced with Google-style link analysis technology to help identify the most useful sites. Overall, if you're serious about tracking something down on the Web, then Raging Search is definitely worth a look.

407

Parallel Gaussian Elimination with Linear Work and Fill.  

National Technical Information Service (NTIS)

This paper presents an algorithm for finding parallel elimination orderings for Gaussian elimination. Viewing a system of equations as a graphs, the algorithm can be applied directly to interval graphs and chordal graphs. For general graphs, the algorithm...

C. Bornstein, B. Maggs, G. Miller, R. Ravi

1997-01-01

408

The STAPL Parallel Container Framework  

E-print Network

, and thread safety. This dissertation presents the STAPL Parallel Container Framework (PCF), which is designed to facilitate the development of generic parallel containers. We introduce a set of concepts and a methodology for assembling a pContainer from...

Tanase, Ilie Gabriel

2012-02-14

409

The Galley Parallel File System  

NASA Technical Reports Server (NTRS)

As the I/O needs of parallel scientific applications increase, file systems for multiprocessors are being designed to provide applications with parallel access to multiple disks. Many parallel file systems present applications with a conventional Unix-like interface that allows the application to access multiple disks transparently. The interface conceals the parallelism within the file system, which increases the ease of programmability, but makes it difficult or impossible for sophisticated programmers and libraries to use knowledge about their I/O needs to exploit that parallelism. Furthermore, most current parallel file systems are optimized for a different workload than they are being asked to support. We introduce Galley, a new parallel file system that is intended to efficiently support realistic parallel workloads. We discuss Galley's file structure and application interface, as well as an application that has been implemented using that interface.

Nieuwejaar, Nils; Kotz, David

1996-01-01

410

On parallel machine scheduling 1  

E-print Network

On parallel machine scheduling 1 machines with setup times. The setup has to be performed by a single server. The objective is to minimize even for the case of two identical parallel machines. This paper presents a pseudopolynomial

Magdeburg, Universität

411

A parallel gravitational N-body kernel  

NASA Astrophysics Data System (ADS)

We describe source code level parallelization for the kira direct gravitational N-body integrator, the workhorse of the starlab production environment for simulating dense stellar systems. The parallelization strategy, called " j-parallelization", involves the partition of the computational domain by distributing all particles in the system among the available processors. Partial forces on the particles to be advanced are calculated in parallel by their parent processors, and are then summed in a final global operation. Once total forces are obtained, the computing elements proceed to the computation of their particle trajectories. We report the results of timing measurements on four different parallel computers, and compare them with theoretical predictions. The computers employ either a high-speed interconnect, a NUMA architecture to minimize the communication overhead or are distributed in a grid. The code scales well in the domain tested, which ranges from 1024 to 65,536 stars on 1-128 processors, providing satisfactory speedup. Running the production environment on a grid becomes inefficient for more than 60 processors distributed across three sites.

Portegies Zwart, Simon; McMillan, Stephen; Groen, Derek; Gualandris, Alessia; Sipior, Michael; Vermin, Willem

2008-07-01

412

A parallel gravitational N-body kernel  

E-print Network

We describe source code level parallelization for the {\\tt kira} direct gravitational $N$-body integrator, the workhorse of the {\\tt starlab} production environment for simulating dense stellar systems. The parallelization strategy, called ``j-parallelization'', involves the partition of the computational domain by distributing all particles in the system among the available processors. Partial forces on the particles to be advanced are calculated in parallel by their parent processors, and are then summed in a final global operation. Once total forces are obtained, the computing elements proceed to the computation of their particle trajectories. We report the results of timing measurements on four different parallel computers, and compare them with theoretical predictions. The computers employ either a high-speed interconnect, a NUMA architecture to minimize the communication overhead or are distributed in a grid. The code scales well in the domain tested, which ranges from 1024 - 65536 stars on 1 - 128 processors, providing satisfactory speedup. Running the production environment on a grid becomes inefficient for more than 60 processors distributed across three sites.

Simon Portegies Zwart; Steve McMillan; Derek Groen; Alessia Gualandris; Michael Sipior; Willem Vermin

2007-11-05

413

Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at = 8 TeV with the ATLAS detector  

NASA Astrophysics Data System (ADS)

The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1 fb-1 of proton-proton collision data at = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via or , where denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of . For a branching fraction of 100%, top squark masses in the range 270-645 GeV are excluded for masses below 30 GeV. For a branching fraction of 50% to either or , and assuming the mass to be twice the mass, top squark masses in the range 250-550 GeV are excluded for masses below 60 GeV. [Figure not available: see fulltext.

Aad, G.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.; Agatonovic-Jovin, T.; Aguilar-Saavedra, J. A.; Agustoni, M.; Ahlen, S. P.; Ahmadov, F.; Aielli, G.; Akerstedt, H.; kesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Albrand, S.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Alimonti, G.; Alio, L.; Alison, J.; Allbrooke, B. M. M.; Allison, L. J.; Allport, P. P.; Almond, J.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Altheimer, A.; Gonzalez, B. Alvarez; Alviggi, M. G.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Amidei, D.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amram, N.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Anduaga, X. S.; Angelidakis, S.; Angelozzi, I.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Bella, L. Aperio; Apolle, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Araque, J. P.; Arce, A. T. H.; Arguin, J.-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Arnold, H.; Arratia, M.; Arslan, O.; Artamonov, A.; Artoni, G.; Asai, S.; Asbah, N.; Ashkenazi, A.; sman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Auerbach, B.; Augsten, K.; Aurousseau, M.; Avolio, G.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Baas, A.; Bacci, C.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Mayes, J. Backus; Badescu, E.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bain, T.; Baines, J. T.; Baker, O. K.; Balek, P.; Balli, F.; Banas, E.; Banerjee, Sw.; Bannoura, A. A. E.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Barnovska, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; da Costa, J. Barreiro Guimares; Bartoldus, R.; Barton, A. E.; Bartos, P.; Bartsch, V.; Bassalat, A.; Basye, A.; Bates, R. L.; Batkova, L.; Batley, J. R.; Battaglia, M.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, S.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Behr, K.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Beringer, J.; Bernard, C.; Bernat, P.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertoli, G.; Bertolucci, F.; Bertsche, D.; Besana, M. I.; Besjes, G. J.; Bessidskaia, O.; Bessner, M. F.; Besson, N.; Betancourt, C.; Bethke, S.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Bierwagen, K.; Biesiada, J.; Biglietti, M.; De Mendizabal, J. Bilbao; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J.-B.; Blazek, T.; Bloch, I.; Blocker, C.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Bock, C.; Boddy, C. R.; Boehler, M.; Boek, T. T.; Bogaerts, J. A.; Bogdanchikov, A. G.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Boldyrev, A. S.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Borri, M.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutouil, S.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bracinik, J.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brelier, B.; Brendlinger, K.; Brennan, A. J.; Brenner, R.; Bressler, S.; Bristow, K.; Bristow, T. M.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Bromberg, C.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Brown, J.; de Renstrom, P. A. Bruckman; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.; Bruschi, M.; Bryngemark, L.; Buanes, T.; Buat, Q.; Bucci, F.; Buchholz, P.

2014-09-01

414

Parallel Pascal - An extended Pascal for parallel computers  

NASA Technical Reports Server (NTRS)

Parallel Pascal is an extended version of the conventional serial Pascal programming language which includes a convenient syntax for specifying array operations. It is upward compatible with standard Pascal and involves only a small number of carefully chosen new features. Parallel Pascal was developed to reduce the semantic gap between standard Pascal and a large range of highly parallel computers. Two important design goals of Parallel Pascal were efficiency and portability. Portability is particularly difficult to achieve since different parallel computers frequently have very different capabilities.

Reeves, A. P.

1984-01-01

415

Measurement of the B?Xs?+?- Branching Fraction and Search for Direct CP Violation from a Sum of Exclusive Final States  

NASA Astrophysics Data System (ADS)

We measure the total branching fraction of the flavor-changing neutral-current process B?Xs?+?-, along with partial branching fractions in bins of dilepton and hadronic system (Xs) mass, using a sample of 471106 ?(4S)?BB events recorded with the BABAR detector. The admixture of charged and neutral B mesons produced at PEP-II2 are reconstructed by combining a dilepton pair with 10 different Xs final states. Extrapolating from a sum over these exclusive modes, we measure a lepton-flavor-averaged inclusive branching fraction B(B?Xs?+?-)=[6.73-0.64+0.70(stat)-0.25+0.34(exp syst)0.50(model syst)]10-6 for m?+?-2>0.1 GeV2/c4. Restricting our analysis exclusively to final states from which a decaying B meson's flavor can be inferred, we additionally report measurements of the direct CP asymmetry ACP in bins of dilepton mass; over the full dilepton mass range, we find ACP=0.040.110.01 for a lepton-flavor-averaged sample.

Lees, J. P.; Poireau, V.; Tisserand, V.; Grauges, E.; Palano, A.; Eigen, G.; Stugu, B.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lee, M. J.; Lynch, G.; Koch, H.; Schroeder, T.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; So, R. Y.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Yushkov, A. N.; Lankford, A. J.; Mandelkern, M.; Dey, B.; Gary, J. W.; Long, O.; Campagnari, C.; Franco Sevilla, M.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Lockman, W. S.; Schumm, B. A.; Seiden, A.; Chao, D. S.; Cheng, C. H.; Echenard, B.; Flood, K. T.; Hitlin, D. G.; Miyashita, T. S.; Ongmongkolkul, P.; Porter, F. C.; Andreassen, R.; Huard, Z.; Meadows, B. T.; Pushpawela, B. G.; Sokoloff, M. D.; Sun, L.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Spaan, B.; Schwierz, R.; Bernard, D.; Verderi, M.; Playfer, S.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Fioravanti, E.; Garzia, I.; Luppi, E.; Piemontese, L.; Santoro, V.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Martellotti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Bhuyan, B.; Prasad, V.; Morii, M.; Adametz, A.; Uwer, U.; Lacker, H. M.; Dauncey, P. D.; Mallik, U.; Chen, C.; Cochran, J.; Meyer, W. T.; Prell, S.; Ahmed, H.; Gritsan, A. V.; Arnaud, N.; Davier, M.; Derkach, D.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Roudeau, P.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Cowan, G.; Bougher, J.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Griessinger, K.; Hafner, A.; Prencipe, E.; Schubert, K. R.; Barlow, R. J.; Lafferty, G. D.; Cenci, R.; Hamilton, B.; Jawahery, A.; Roberts, D. A.; Cowan, R.; Dujmic, D.; Sciolla, G.; Cheaib, R.; Patel, P. M.; Robertson, S. H.; Biassoni, P.; Neri, N.; Palombo, F.; Cremaldi, L.; Godang, R.; Sonnek, P.; Summers, D. J.; Simard, M.; Taras, P.; De Nardo, G.; Monorchio, D.; Onorato, G.; Sciacca, C.; Martinelli, M.; Raven, G.; Jessop, C. P.; LoSecco, J. M.; Honscheid, K.; Kass, R.; Brau, J.; Frey, R.; Sinev, N. B.; Strom, D.; Torrence, E.; Feltresi, E.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simi, G.; Simonetto, F.; Stroili, R.; Akar, S.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Sitt, S.; Biasini, M.; Manoni, E.; Pacetti, S.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Chrzaszcz, M.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Perez, A.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Olsen, J.; Smith, A. J. S.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Li Gioi, L.; Piredda, G.; Bnger, C.; Grnberg, O.; Hartmann, T.; Leddig, T.; Vo, C.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Hamel de Monchenault, G.; Vasseur, G.; Yche, Ch.; Anulli, F.; Aston, D.; Bard, D. J.; Benitez, J. F.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Ebert, M.; Field, R. C.; Fulsom, B. G.; Gabareen, A. M.; Graham, M. T.; Hast, C.; Innes, W. R.; Kim, P.; Kocian, M. L.; Leith, D. W. G. S.; Lewis, P.; Lindemann, D.; Lindquist, B.; Luitz, S.; Luth, V.; Lynch, H. L.; MacFarlane, D. B.; Muller, D. R.; Neal, H.; Nelson, S.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Snyder, A.; Su, D.; Sullivan, M. K.; Va'vra, J.; Wagner, A. P.; Wang, W. F.; Wisniewski, W. J.; Wittgen, M.; Wright, D. H.; Wulsin, H. W.; Ziegler, V.; Park, W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Burchat, P. R.; Puccio, E. M. T.; Alam, M. S.; Ernst, J. A.; Gorodeisky, R.; Guttman, N.; Peimer, D. R.; Soffer, A.; Spanier, S. M.; Ritchie, J. L.; Ruland, A. M.; Schwitters, R. F.; Wray, B. C.; Izen, J. M.; Lou, X. C.; Bianchi, F.; De Mori, F.; Filippi, A.; Gamba, D.; Zambito, S.; Lanceri, L.; Vitale, L.; Martinez-Vidal, F.; Oyanguren, A.; Villanueva-Perez, P.; Albert, J.; Banerjee, Sw.; Bernlochner, F. U.; Choi, H. H. F.; King, G. J.; Kowalewski, R.; Lewczuk, M. J.; Lueck, T.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Tasneem, N.; Gershon, T. J.; Harrison, P. F.; Latham, T. E.; Band, H. R.; Dasu, S.; Pan, Y.; Prepost, R.; Wu, S. L.; BaBar Collaboration

2014-05-01

416

Measurement of the B->Xsl+l- branching fraction and search for direct CP violation from a sum of exclusive final states  

E-print Network

We present a measurement of the total branching fraction of the flavor-changing neutral-current process B->Xsl+l-, along with partial branching fractions in bins of dilepton and hadronic system (Xs) mass, using a sample of 471x10^6 Upsilon(4S)->BBbar events recorded with the BaBar detector at the PEP-II e+e- collider. B mesons are reconstructed by combining a dilepton pair, either e+e- or mu+mu-, with 10 different Xs final states containing exactly one charged or neutral kaon, two or fewer charged pions, and at most one pi0. Using a sum over these exclusive modes as the basis for extrapolation to the fully inclusive rate, we measure a lepton-flavor-averaged inclusive branching fraction BF(B->Xsl+l-) = (6.73 +0.70-0.64[stat] +0.34-0.25[exp syst] +/- 0.50[model syst])x10^-6 for m(l+l-)^2>0.1 GeV^2/c^4. Restricting our analysis exclusively to final states from which a decaying B meson's flavor can be inferred, we additionally report measurements of the direct CP asymmetry ACP in bins of dilepton mass; over the full dilepton mass range, we find ACP=0.04 +/- 0.11 +/- 0.01$ for a lepton-flavor-averaged sample.

The BABAR Collaboration; J. P. Lees; others

2013-12-18

417

Results of Quenching Factor Measurements of CaWO at mK Temperatures for the Direct Dark Matter Search Experiment CRESST  

NASA Astrophysics Data System (ADS)

The CRESST experiment aims at a direct detection of WIMP dark matter (DM) using scintillating CaWO crystals operated as phonon detectors at mK temperatures. An important feature of the experiment is the active background discrimination technique exploiting the different light outputs depending on the kind of particle interaction. The reduced light yield of nuclear recoils compared to electron recoils is quantified by quenching factors (QFs). The precise measurement of the QFs and thus the identification of the individual recoiling nucleus in the multi-target material CaWO is crucial for neutron background discrimination and assuming a positive DM signal would allow to a certain extent WIMP-mass spectroscopy. At the Munich tandem accelerator a dedicated neutron scattering facility has been set up to measure the QFs of CaWO, in particular that of tungsten, at mK temperatures. Monoenergetic neutrons (11 MeV) produced by the accelerator are scattered off a CRESST-like detector module that is operated in a dilution refrigerator. In this setup, the recoiling nucleus (O, Ca and W) is identified by time-of-flight measurement in liquid-scintillator detectors placed at fixed scattering angles. The QF of W could be determined with unprecedented accuracy at mK temperatures and under realistic measurement conditions: (preliminary value).

Strauss, R.; Ciemniak, C.; Deuter, G.; Feilitzsch, F. V.; Gtlein, A.; Hagn, H.; Hellgartner, D.; Jochum, J.; Lanfranchi, J.-C.; Mnster, A.; Potzel, W.; Roth, S.; Rottler, K.; Sailer, C.; Scholl, S.; Sivers, M. V.; Usherov, I.; Wawoczny, S.; Willers, M.; Wstrich, M.; Zller, A.

2014-09-01

418

Search for direct top squark pair production in final states with one isolated lepton, jets, and missing transverse momentum in sqrt[s] = 7 TeV pp collisions using 4.7 fb(-10 of ATLAS data.  

PubMed

A search is presented for direct top squark pair production in final states with one isolated electron or muon, jets, and missing transverse momentum in proton-proton collisions at sqrt[s] = 7 TeV. The measurement is based on 4.7 fb(-1) of data collected with the ATLAS detector at the LHC. Each top squark is assumed to decay to a top quark and the lightest supersymmetric particle (LSP). The data are found to be consistent with standard model expectations. Top squark masses between 230 GeV and 440 GeV are excluded with 95% confidence for massless LSPs, and top squark masses around 400 GeV are excluded for LSP masses up to 125 GeV. PMID:23215588

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2012-11-21