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Last update: August 15, 2014.
1

Natural convection in a vertical plane channel: DNS results for high Grashof numbers  

NASA Astrophysics Data System (ADS)

The turbulent natural convection of a gas (Pr = 0.71) between two vertical infinite walls at different but constant temperatures is investigated by means of direct numerical simulation for a wide range of Grashof numbers (6.0 × 106 > Gr > 1.0 × 103). The maximum Grashof number is almost one order of magnitude higher than those of computations reported in the literature so far. Results for the turbulent transport equations are presented and compared to previous studies with special attention to the study of Verteegh and Nieuwstadt (Int J Heat Fluid Flow 19:135-149, 1998). All turbulence statistics are available on the TUHH homepage (http://www.tu-harburg.de/tt/dnsdatabase/dbindex.en.html). Accuracy considerations are based on the time averaged balance equations for kinetic and thermal energy. With the second law of thermodynamics Nusselt numbers can be determined by evaluating time averaged wall temperature gradients as well as by a volumetric time averaged integration. Comparing the results of both approaches leads to a direct measure of the physical consistency.

Kiš, P.; Herwig, H.

2014-02-01

2

Numbers  

NSDL National Science Digital Library

This engaging web site contains information and interactive applets related to various number systems: Egyptian, Babylonian, Chinese, Greek, Roman, Mayan, and Arabic. Users learn the history and structure of each system as well as how to count and write numbers. The site also allows users to explore finger systems, calculating machines, other number bases, and "interesting numbers." A series of pages on data and graphs includes information and activities on gathering, analyzing, graphing and sorting data. (Because the section on the Arabic number system is so extensive, it is cataloged separately as a related resource.)

Edkins, Jo

2006-01-01

3

Buoyant convection of low Prandtl number melts in horizontal boat configuration  

NASA Astrophysics Data System (ADS)

Results of experimental investigations and numerical simulations of buoyant convection in metal and semiconductor melt layers with an applied horizontal temperature gradient are presented. Stability diagrams characterize the transition from steady to unsteady convection in terms of Grashof number, aspect ratio and Prandtl number. Periodic temperature oscillations of the melt are analysed and the oscillatory convection mechanism is discussed by numerical results. In order to grow striation-free crystals by means of the horizontal Bridgman method, the necessary conditions can be concluded by the results obtained.

Kuhl, R.; Wilke, H.

4

Number Track  

NSDL National Science Digital Library

Students can use this interactive Flash applet to practice ordering whole numbers within 20. The applet displays a track and number tiles, which the user drags to create the correct sequence of numbers 1 through 20. Users may choose from four levels: place 5 missing numbers, place 10 numbers, arrange all 20 numbers, or create your own challenge.

Bunker, Dan

2010-01-01

5

Number Sense  

NSDL National Science Digital Library

Hacker has given you a challenge. Heâll run his number machine to create a number. Then youâll get three numbers between one and nine. The challenge is to make a number that is larger than the one on Hackerâs machine. Be careful though--Hacker will give you numbers that canât be bigger than his!

2008-01-01

6

Number Line  

NSDL National Science Digital Library

This iOS app helps students to visualize number sentences and create models for addition, subtractions, multiplication, and division. The number line can be adjusted to represent multiples of numbers from one to one hundred.

Clarity Innovations, Inc.

2013-11-22

7

Story Numbers.  

ERIC Educational Resources Information Center

A concrete approach to prime numbers is presented using rectangles and triangles to construct a building for each number so that each story represents a pair of factors and the triangular-shaped roof represents the number. (MP)

Swafford, Jane; McGinty, Robert

1978-01-01

8

Number Flash  

NSDL National Science Digital Library

This iOS app helps students make the transition from counting to number recognition by thinking of a number of objects in relation to five and ten. The app displays a set number of items from one to twenty in ten frames then flashes away after the preset number of seconds. The user must identify the number that was shown on the ten frames.

Mark, Mitchell

2013-03-10

9

Nifty Numbers!  

NSDL National Science Digital Library

You will be working with numbers in all sorts of ways. First, you will play cop by picking numbers based on their divisibility. Then you will be adding and subtracting fractions in two fun and exciting games. First, as a cop, you will catch numbers that are divisible by which ever number you pick, avoinding crashing into non-divisible numbers. Number Cop-Divisibility Now, play Fishy Fractions! and help feed the seagull by practicing adding fractions. Make sure you read the instructions before getting started! Make sure to simplify your answers! After you ...

Miss.cochran

2008-03-26

10

Tooth Numbering  

MedlinePLUS

... numbered as well. Illustrations created by Simple Steps designer Michael Becker Universal Numbering System Adults In this ... indicates that it is a deciduous (primary or "baby") tooth. So, a child's first tooth on the ...

11

Negative Numbers  

NSDL National Science Digital Library

This article is an account of how negative numbers became part of the "vocabulary" of mathematicians and of some of the earliest appearances of negative numbers in calculations of the ancient civilizations of China, India and Greece. Although negative numbers were used in calculations, negative answers to mathematical problems were considered meaningless or impossible. The troubled history of negative numbers presented in this article shows how the simple mathematical principles taken for granted today have taken thousands of years to develop.

Howard, Jill

2009-05-01

12

Number Balance  

NSDL National Science Digital Library

This open-ended interactive Flash applet helps students develop operation and number sense, facility with number facts, and understanding of equations. Users designate single-digit whole numbers or integers and operations on both sides of an equation and test for balance. Users can enter numbers by using the keyboard or arrow buttons or by dragging number tiles. Each element can be hidden and a seesaw may be toggled on/off. Teachers may use this applet to lead instruction, or students may use it independently to perform specific investigations or explore freely. Supplementary documents include Objectives, containing teaching suggestions, and a student recording sheet.

Bunker, Dan

2005-01-01

13

Number Grids and Number Triangles  

NSDL National Science Digital Library

Practice counting, counting by tens, place value, and fact families by entering your answers into the blank boxes; click the big blue and green buttons to check your work. Each of the five levels of Number Grid activities displays a section of a matrix containing a set of of consecutive whole numbers. A move from one number to the next within a row corresponds to a change of one; a move from one number to the next within a column refers to a change of ten. The three levels of Number Triangle activities provide practice with fact families and inverse relationships through flash cards. An addition/subtraction Number Triangle has two addends and a sum; a multiplication/division Number Triangle has two factors and a product.

Brown, Quincy; Fetter, Annie

2006-08-01

14

Matching Numbers  

NSDL National Science Digital Library

This interactive Flash version of the familiar game Concentration helps students develop number sense by matching various symbolic and pictorial representations of single digit numbers. The scoring rewards a systematic strategy over random guessing. The resource includes teacher notes with suggestions for implementation and differentiation, discussion questions, and printable sets of cards (pdf).

2014-01-01

15

Complex Numbers  

NSDL National Science Digital Library

Written by Tony R. Kuphaldt and Jason Starck, this chapter of All About Circuit's second volume on Alternating Current describes complex numbers: "In order to successfully analyze AC circuits, we need to work with mathematical objects and techniques capable of representing these multi-dimensional quantities. Here is where we need to abandon scalar numbers for something better suited: complex numbers." In addition to the introduction and credits to contributors, the chapter has seven sections: Vectors and AC waveforms, Simple vector addition, Complex vector addition, Polar and rectangular notation, Complex number arithmetic, More on AC "polarity," and Some examples with AC circuits. Each section has clear illustrations and a concise, bulleted review of what was covered at the end.

Kuphaldt, Tony R.

2008-07-15

16

Ordering numbers  

NSDL National Science Digital Library

Khan Academy Exercise bank - Ordering numbers Students are able to use the knowledge map and progress tracking tool to record and support their learning goals. Hints are provided and supporting video tutorials are identified and linked.

Khan, Sal

2011-04-01

17

Number Line  

NSDL National Science Digital Library

In this brief article the numerous uses of the number line are detailed: counting, measurement, addition, subtraction, decimals, and fractions. The article contains visual representations of the some of the concepts and links to related topics.

2012-08-27

18

Number Cruncher  

NSDL National Science Digital Library

Similar to the original "Function Machine" but lists input and output in a table and will not let the user attempt to guess the rule without having at least two data points. Number Cruncher is one of the Interactivate assessment explorers.

19

Number Patterns  

NSDL National Science Digital Library

In this lesson, learners are challenged to discover the relationship among six numbers. The objective of this activity is to engage learners in a problem-solving situation in which they practice aspects of the process of science. Learners can use an included Science Flowchart to chart their scientific experience. This lesson serves as a good introduction to the nature of scientific inquiry.

Scotchmoor, Judy

2010-01-01

20

Numbers Sense  

ERIC Educational Resources Information Center

This article reports on work undertaken by schools as part of Qualifications and Curriculum Authority's (QCA's) "Engaging mathematics for all learners" project. The goal was to use in the classroom, materials and approaches from a Royal Institution (Ri) Year 10 master-class, "Number Sense", which was inspired by examples from Michael Blastland and…

Kathotia, Vinay

2009-01-01

21

Table Numbers  

NSDL National Science Digital Library

This interactive applet helps students develop fluency with multiplication facts. Users chose a factor from among the digits 1-9, each of which is associated with a mnemonic graphic. The applet then displays three numbers and the user selects the one which is a multiple of the chosen factor. The player must respond correctly to ten examples to complete a round. A one-point penalty for selecting an incorrect product discourages guessing. The few words that are displayed are in Dutch.

2008-01-01

22

Number 8  

NASA Technical Reports Server (NTRS)

29 January 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a spotted, high latitude plain, south of the Argyre basin. When the image was received from Mars by the MOC operations team, they noticed -- with a sense of humor -- the number '8' on this martian surface. The '8' is located at the center-right and is formed by the rims of two old impact craters that have been eroded and partly-filled and partly-buried beneath the surface.

Location near: 68.6oS, 38.4oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

2006-01-01

23

Topics in Number Theory: The Number Game.  

ERIC Educational Resources Information Center

This teacher's guide contains nine topics in number theory. Suggested questions for the teacher, short investigations, and possible exercises for the student are included. Chapter 1 is an introduction to sequences and series using geoboard activities involving triangular numbers, square numbers, rectangular numbers, and pentagonal numbers. The…

Batra, Laj, Ed.; And Others

24

Estimates for the two-dimensional Navier-Stokes equations in terms of the Reynolds number  

NASA Astrophysics Data System (ADS)

The tradition in Navier-Stokes analysis of finding estimates in terms of the Grashof number Gr, whose character depends on the ratio of the forcing to the viscosity ?, means that it is difficult to make comparisons with other results expressed in terms of Reynolds number Re, whose character depends on the fluid response to the forcing. The first task of this paper is to apply the approach of Doering and Foias [C. R. Doering and C. Foias, J. Fluid Mech. 467, 289 (2002)] to the two-dimensional Navier-Stokes equations on a periodic domain [0,L]2 by estimating quantities of physical relevance, particularly long-time averages <.>, in terms of the Reynolds number Re=Ul/?, where U2=L-2<||u||22> and l is the forcing scale. In particular, the Constantin-Foias-Temam upper bound [P. Constantin, C. Foias, and R. Temam, Physica D 30, 284 (1988)] on the attractor dimension converts to al2Re(1+ln Re)1/3, while the estimate for the inverse Kraichnan length is (al2Re)1/2, where al is the aspect ratio of the forcing. Other inverse length scales, based on time averages, and associated with higher derivatives, are estimated in a similar manner. The second task is to address the issue of intermittency: it is shown how the time axis is broken up into very short intervals on which various quantities have lower bounds, larger than long time averages, which are themselves interspersed by longer, more quiescent, intervals of time.

Gibbon, J. D.; Pavliotis, G. A.

2007-06-01

25

Number Square Puzzle: 10 Missing Numbers  

NSDL National Science Digital Library

This activity for the interactive white board (free access with registration) allows the learner to explore the patterns in the hundreds chart and notice the relationships between the numbers in the horizontal and vertical puzzles. Users drag and drop the individual numbers back in their correct places in the blank 10 X 10 grid.

2012-07-19

26

Numbers and Operations  

NSDL National Science Digital Library

Numbers, Matching and Addition Let\\'s count How many chicks are there? Great! Now lets try Number Match Let\\'s try Seahorse Counting Now Concentrate on Concentration Number Match Addition Practice Quick Adding and Robot Addition Make the number with Base 10 ...

Williams, Mrs.

2008-04-03

27

Are Numbers Gendered?  

ERIC Educational Resources Information Center

We examined the possibility that nonsocial, highly generic concepts are gendered. Specifically, we investigated the gender connotations of Arabic numerals. Across several experiments, we show that the number 1 and other odd numbers are associated with masculinity, whereas the number 2 and other even numbers are associated with femininity, in ways…

Wilkie, James E. B.; Bodenhausen, Galen V.

2012-01-01

28

Sum-Difference Numbers  

ERIC Educational Resources Information Center

Starting with an interesting number game sometimes used by school teachers to demonstrate the factorization of integers, "sum-difference numbers" are defined. A positive integer n is a "sum-difference number" if there exist positive integers "x, y, w, z" such that n = xy = wz and x ? y = w + z. This paper characterizes all sum-difference numbers

Shi, Yixun

2010-01-01

29

Enriching Number Knowledge  

ERIC Educational Resources Information Center

Exploring number systems of other cultures can be an enjoyable learning experience that enriches students' knowledge of numbers and number systems in important ways. It helps students deepen mental computation fluency, knowledge of place value, and equivalent representations for numbers. This article describes how the author designed her…

Mack, Nancy K.

2011-01-01

30

PET: [number sign]1 is number one  

SciTech Connect

Subsidized in the beginning by bottle deposits, now spurred by the ability of curbside recycling to collect more than soda bottles, polyethylene terephthalate (PET) recycling has made great strides in the last 10 years. Its growth rate and increased market demand are the envy of many other materials. Appropriate, if not deliberately, this number-one resin is listed under the Society for the Plastics Industry's resin identification code as [number sign]1. Unlike most recyclables, the market demand for recycled PET is greater than the supply. As a result, demand not supply, is fueling the increase in PET recycling.

Miller, C.

1994-09-01

31

Manipulative Models for Figurate Numbers.  

ERIC Educational Resources Information Center

Discusses figurate number learning activities using patterns and manipulative models. Provides examples of square numbers, triangular numbers, pentagonal numbers, hexagonal numbers, and oblong numbers. (YP)

Robold, Alice I.

1989-01-01

32

Number Sense Made Simple Using Number Patterns  

ERIC Educational Resources Information Center

This article highlights investigating intriguing number patterns utilising an emerging technology called the Square Tool. Mathematics teachers of grades K-12 will find the Square Tool useful in making connections and bridging the gap from the concrete to the abstract. Pattern recognition helps students discover various mathematical concepts. With…

Su, Hui Fang Huang; Marinas, Carol; Furner, Joseph

2011-01-01

33

Summing Consecutive Numbers  

NSDL National Science Digital Library

This problem offers a simple context to begin an exploration of the properties of numbers and to make conjectures about those properties. Learners explore the sums of consecutive numbers and whether all positive numbers from 1-30 can be written as the sum of two or more consecutive numbers. The Teachers' Notes page offers suggestions for implementation, key discussion questions, ideas for extension and support.

2008-09-01

34

Whole Number Cruncher  

NSDL National Science Digital Library

Give input to the Whole Number Cruncher and try to guess what it did from the output it generates. This activity only generates multiplication and addition functions to avoid outputting any negative numbers. Whole Number Cruncher is one of the Interactivate assessment explorers.

35

Discovery: Prime Numbers  

ERIC Educational Resources Information Center

Prime numbers are important as the building blocks for the set of all natural numbers, because prime factorisation is an important and useful property of all natural numbers. Students can discover them by using the method known as the Sieve of Eratosthenes, named after the Greek geographer and astronomer who lived from c. 276-194 BC. Eratosthenes…

de Mestre, Neville

2008-01-01

36

Estimating Large Numbers  

ERIC Educational Resources Information Center

Despite their importance in public discourse, numbers in the range of 1 million to 1 trillion are notoriously difficult to understand. We examine magnitude estimation by adult Americans when placing large numbers on a number line and when qualitatively evaluating descriptions of imaginary geopolitical scenarios. Prior theoretical conceptions…

Landy, David; Silbert, Noah; Goldin, Aleah

2013-01-01

37

Random Number Generation  

NSDL National Science Digital Library

The process of creating numbers that simulate randomness on a computer is known as pseudorandom number generation. The "pseudo" in pseudo random refers to the fact that if you use a rule to generate a number, it is by definition not random, though it may appear so, and be close enough to random for all practical purposes.

Joiner, David; The Shodor Education Foundation, Inc.

38

Law of Large Numbers  

NSDL National Science Digital Library

The controls on this applet let you change the number of trials, the probability of success in each trial, and toggle between viewing either the difference between the number of successes and the expected number of successes, or the difference between the percentage of successes and the probability of success in each trial.

Stark, Philip B.

2009-10-26

39

Theory of Numbers  

NSDL National Science Digital Library

This course provides an introduction to number theory, including topics such as prime numbers, congruences, quadratic reciprocity, diophantine equations, irrational numbers, continued fractions and elliptic curves. The materials include lecture notes, exams and assignments with solutions. MIT presents OpenCourseWare as free educational material online. No registration or enrollment is required to use the materials.

Olsson, Martin

2010-12-27

40

Decompose That Teen Number!  

NSDL National Science Digital Library

The students will receive explicit instruction from the teacher on the definition of decomposing a number and how to represent a decomposition with manipulatives, drawings, and equations. The students will use linking cubes to reflect numbers from 11-19, and to show their understanding of how to decompose a number. Students will record decompositions as an equation.

Marmitt, Robin

2012-09-03

41

Number Relationships in Preschool  

ERIC Educational Resources Information Center

When a child understands number relationships, he or she comprehends the meaning of numbers by developing multiple, flexible ways of representing them. The importance of developing number relationships in the early years has been highlighted because it helps children build a good foundation for developing a more sophisticated understanding of…

Jung, Myoungwhon

2011-01-01

42

Numbers in the News  

NSDL National Science Digital Library

All those numbers in the newspaper: what do they mean? Challenge learners to find out as they develop their number sense. Distribute newspaper pages to learners so that each pair gets a section with numbers at the right level of difficulty: easyâweather or sports scores; mediumâclothing ads or event listings with times and dates; hardâautomobile ads, monetary exchange rates. Learners try to find the smallest and largest numbers on the page (including best deal/best rate) and explain to others what they found. Variation for younger learners: look for the largest or smallest number on a walk around the building or around the block. Available as a web page and downloadable pdf.

Terc

2010-01-01

43

Estimating large numbers.  

PubMed

Despite their importance in public discourse, numbers in the range of 1 million to 1 trillion are notoriously difficult to understand. We examine magnitude estimation by adult Americans when placing large numbers on a number line and when qualitatively evaluating descriptions of imaginary geopolitical scenarios. Prior theoretical conceptions predict a log-to-linear shift: People will either place numbers linearly or will place numbers according to a compressive logarithmic or power-shaped function (Barth & Paladino, ; Siegler & Opfer, ). While about half of people did estimate numbers linearly over this range, nearly all the remaining participants placed 1 million approximately halfway between 1 thousand and 1 billion, but placed numbers linearly across each half, as though they believed that the number words "thousand, million, billion, trillion" constitute a uniformly spaced count list. Participants in this group also tended to be optimistic in evaluations of largely ineffective political strategies, relative to linear number-line placers. The results indicate that the surface structure of number words can heavily influence processes for dealing with numbers in this range, and it can amplify the possibility that analogous surface regularities are partially responsible for parallel phenomena in children. In addition, these results have direct implications for lawmakers and scientists hoping to communicate effectively with the public. PMID:23819823

Landy, David; Silbert, Noah; Goldin, Aleah

2013-07-01

44

Interactive Fraction Number Lines  

NSDL National Science Digital Library

In this lesson students make models of fractions, including a human number line. Using a number line, students develop conceptual understanding of fractions. Students use the number line to represent and compare fractions less than one. The activities are engaging and include full participation/engagement of all students. The fractions are limited to positive fractions less than one with a denominator of 2 or 4 including 0 and 1 whole.

Green, Michael

2012-05-25

45

Guess the Number  

NSDL National Science Digital Library

This interactive game gives students practice in counting and ordering numbers. Users try to determine the magician's secret number in as few tries as possible by adjusting their successive guesses according to feedback (too high or too low). Solvers can choose from three ranges of numbers (1 to 10, 1 to 100, or -1000 to 1000) and choose whether or not to view previous guesses.

2011-01-01

46

Your Number Was  

NSDL National Science Digital Library

This problem provides an opportunity to introduce the concept of representing operations on unknown numbers algebraically and leads to work on inverse operations. Students are asked to think of a number, follow a sequence of computational instructions and finally to enter the result into the "machine." Students explore how the "machine" works out the starting number. The Teachers' Notes page offers rationale, suggestions for implementation, discussion questions, ideas for extension and support.

2010-10-01

47

Your Number Is...  

NSDL National Science Digital Library

This problem provides an opportunity to introduce a visual way of representing operations on unknown numbers to help lead students to using a symbolic representation. Learners are asked to think of a number and then through an interactivity are given a sequence of operational instructions to follow which leads all students to the same final number. The Teachers' Notes page offers suggestions for implementation, key discussion questions, ideas for extension and support.

2010-10-01

48

Biggest Number Game  

NSDL National Science Digital Library

In this game, learners build a multi-digit number by rolling dice and deciding which place value box to place each number. This requires strategy and planning as they must consider what they may roll in the future and which boxes are still open. Learners can compete to make the largest or smallest numbers during each round of play. Educators can use this game to introduce and/or practice strategy, risk, and place value.

Houston, Children'S M.

2013-05-15

49

A Square of Numbers  

NSDL National Science Digital Library

In this problem students practice basic number facts while developing systematic thinking and understanding of properties of numbers and operations. Four calculations are presented in a square configuration; solvers arrange the numbers 1 through 8 to make the calculations correct. An interactive applet is provided. The Teachers' Notes page offers suggestions for implementation, discussion questions, ideas for extension and support, and a downloadable pdf of the puzzle.

2009-09-01

50

My First Number Book  

NSDL National Science Digital Library

In this activity, "students produce a book that includes a page for numbers 0-10. On each page they write the numeral, the word for that numeral and place the correct number of stickers to represent the numeral. The cover includes a title, student's name and an illustration." (from Beacon Learning Center)

Center, Beacon L.

2008-12-15

51

Blank Number Lines  

NSDL National Science Digital Library

Once students have gotten the concept of the number line, you can have them make their own using these blank number lines. You can even have them use it for skip counting. http://www.math-drills.com/numbersense/numberline_blank.html

2012-04-30

52

Language: Life without numbers.  

PubMed

If your language did not have words for numbers, would you be able to think about numeric quantities? An Amazonian culture where number words are limited to one, two and many has provided new insights to the interaction between thought and language. PMID:15530385

Hespos, Susan J

2004-11-01

53

Language: Life without Numbers  

Microsoft Academic Search

If your language did not have words for numbers, would you be able to think about numeric quantities? An Amazonian culture where number words are limited to one, two and many has provided new insights to the interaction between thought and language.

Susan J. Hespos

2004-01-01

54

Prime Numbers Video  

NSDL National Science Digital Library

This 4-minute video introduces the definition of a prime number and illustrates it through a discussion of factors and composite numbers. It makes use of the definition to explain why 1 is not a prime and ends with a question for the viewer to ponder.

2010-01-01

55

Number Base Clocks  

NSDL National Science Digital Library

Visually explore counting and place value with different number bases, from base 2 to base 16, and up to the hundreds place using a clock like interface. The activity also allows you to look at the numbers on the clock in base 10 or in your other chosen base to explore the relationship between those values.

56

Guess My Number  

NSDL National Science Digital Library

In this math activity, learners play a game similar to 20 Questions, in which learners must identify a secret number drawn from a bag. Learners practice their logical thinking and questioning skills as they develop their number sense. This activity guide contains a material list, sample questions to ask, literary connections, extensions, and alignment to local and national standards.

Houston, Children'S M.

2014-04-07

57

Fraction Number Line  

NSDL National Science Digital Library

Using this interactive fraction number line, students can identify and locate equivalent fractions as well as compare fractions. They can move the mouse to the left or right and "mark" fractions on the number line. A section called "Which is Larger?" provides examples of fraction pairs to compare.

2010-01-01

58

Numbers Many Ways  

NSDL National Science Digital Library

In this lesson, students work with subtraction at the intuitive level as they explore number families and ways to decompose numbers to 10. They will also identify members of 'fact families.' This is lesson 5 in an 8-lesson unit called, "Begin with Buttons".

Math, Illuminations N.

2009-01-13

59

The Fibonacci Numbers.  

ERIC Educational Resources Information Center

After a brief historical account of Leonardo Pisano Fibonacci, some basic results concerning the Fibonacci numbers are developed and proved, and entertaining examples are described. Connections are made between the Fibonacci numbers and the Golden Ratio, biological nature, and other combinatorics examples. (MDH)

Onstad, Torgeir

1991-01-01

60

1.NBT Ordering Numbers  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Malik is given a list of numbers: 1 \\ \\ 5 \\ \\ 10 \\ \\ 50 \\ \\ 100 He wants to include the following numbers so all numbers will be listed in order from l...

61

Introduction to Negative Numbers  

NSDL National Science Digital Library

This lesson plan based on a Cyberchase activity, first addresses a common misconception: starting measurement from 1 instead of 0. Then, it introduces negative numbers by extending a number line beyond 0 in the negative (left) direction. It is motivated by the Cyber Squadâs mission to find the captured Cyberchase Council on a particular floor of a tall building as seen in two quicktime videos: âImportance of the Origin" and "Inventing Negative Numbers" (each are cataloged separately). In addition to the learning activity, other support materials are included: handouts, assessments and answer keys.

Wnet.org

2006-01-01

62

On Hultman Numbers  

NASA Astrophysics Data System (ADS)

Finding a sequence of transpositions that transforms a given permutation into the identity permutation and is of the shortest possible length is an important problem in bioinformatics. Here, a transposition consists in exchanging two contiguous intervals of the permutation. Bafna and Pevzner introduced the cycle graph as a tool for working on this problem. In particular, they took advantage of the decomposition of the cycle graph into so-called alternating cycles. Later, Hultman raised the question of determining the number of permutations with a cycle graph containing a given quantity of alternating cycles. The resulting number is therefore similar to the Stirling number of the first kind. We provide an explicit formula for computing what we call the Hultman numbers, and give a few numerical values. We also derive formulae for related cases, as well as for a much more general problem. Finally, we indicate a counting result related to another operation on permutations called the "block-interchange".

Doignon, Jean-Paul; Labarre, Anthony

2007-06-01

63

Zero: A "None" Number?  

ERIC Educational Resources Information Center

This article discusses the challenges students face in making sense of zero as a number. A range of different student responses to a computation problem involving zero reveal students' different understandings of zero.

Anthony, Glenda J.; Walshaw, Margaret A.

2004-01-01

64

High Mach Number Combustion.  

National Technical Information Service (NTIS)

Recent developments in the mathematical theory of high Mach number combustion are presented. The phenomena in this regime are enormously complex and the mechanisms responsible for the variety of physical phenomena are poorly understood. The current advanc...

A. Majda

1986-01-01

65

The Numbers Game.  

ERIC Educational Resources Information Center

Describes a simple activity that explores and reveals the principles of significant figures and scientific notation using a 500 gram bag of unpopped popcorn. Students must devise a method for determining the number of kernels in the bag. (DDR)

Lustick, David

1997-01-01

66

Uniform random number generators  

Microsoft Academic Search

We briefly overview the design principles, implementationtechniques, and empirical testing of uniformrandom number generators for simulation. We firstdiscuss some philosophical issues and quality criteria.Then we explain a few concrete families of generatorsand give appropriate references to further details andto recommended implementations.1. WHAT ARE WE LOOKING FOR?1.1. DefinitionWhat we call a random number generator (RNG)is actually a program that produces, once

Pierre L'Ecuyer

1998-01-01

67

High Lundquist Number Reconnection  

NASA Astrophysics Data System (ADS)

In recent years there has been a resurgence of interest in exploring the properties of resistive magnetic reconnection layers. This was spurred on by the observations that at high Lundquist number these systems depart from the traditional Sweet-Parker scaling, opening the possibility of so-called fast resistive magnetic reconnection. This proceedings presents my recent efforts at simulating resistive magnetic reconnection layers in high Lundquist number systems highlighting the numerical algorithms, simulation results and convergence behavior.

Gardiner, T. A.

2011-10-01

68

Number Sense Challenges  

NSDL National Science Digital Library

The resource consists of 3 unrelated problem-solving challenges that can build number sense. Activity 1: Students explore the concept of a million to determine if 1 million dollar bills can fit into a standard suitcase. Activity 2: Students use a paper disk to estimate and name exact fractions between 0 and 1. Activity 3: Students explore the effect of addition, subtraction, multiplication, and division on decimal numbers by playing an engaging game.

Illuminations, Nctm

2009-06-23

69

Controlled Conspiracy Number Search  

Microsoft Academic Search

In this paper we present a new conspiracy number search algorithm (CNS), called ControlledConspiracy Number Search (CCNS). The basic steps of any CNS algorithm, theselection, the expansion, and the backup of results have been modified compared to otherCNS algorithms. The selection is done by assigning demands, so called CN targets, to thenodes of the tree in a top-down fashion. By

Ulf Lorenz; Valentin Rottmann; Rainer Feldmann

1995-01-01

70

Dangerous Doubles (Doubling Numbers)  

NSDL National Science Digital Library

This lesson teaches students to use the strategy doubling numbers and doubles plus or minus one in order to use mental math to add one digit numbers. The students are engaged in learning through the read aloud of Double the Ducks by Stephen Murphy and then get to work with a partner to draw doubles and write equations that relate to their drawings. Students individually work on solving word problems using these strategies and manipulatives as necessary to solve.

Sharrer, Stephanie

2012-07-14

71

SeanNumbers-Ofala  

NSDL National Science Digital Library

This web page contains links to a video and several downloadable pdf files documenting the discussions of a third grade class investigating even and odd numbers. Included are a 10-minute Blue Stream video segment in which students discuss a classmate's suggestion that the number 6 could be even or odd, a document providing background information on the investigation that led to the discussion, a transcript of the video, and the teacher's journal entry reflecting on the discussion and its implications.

2010-02-01

72

Beyond the number domain.  

PubMed

In a world without numbers, we would be unable to build a skyscraper, hold a national election, plan a wedding or pay for a chicken at the market. The numerical symbols used in all these behaviors build on the approximate number system (ANS) which represents the number of discrete objects or events as a continuous mental magnitude. Here, we first discuss evidence that the ANS bears a set of behavioral and brain signatures that are universally displayed across animal species, human cultures and development. We then turn to the question of whether the ANS constitutes a specialized cognitive and neural domain - a question central to understanding how this system works, the nature of its evolutionary and developmental trajectory and its physical instantiation in the brain. PMID:19131268

Cantlon, Jessica F; Platt, Michael L; Brannon, Elizabeth M

2009-02-01

73

Positive About Negative Numbers  

NSDL National Science Digital Library

This article is devoted to the mathematical topic of negative numbers and provides a series of primary resources designed to familiarize children with the notion of counting on either side of a central point. The article presents that the activities listed should be played sequentially to build precursory ideas in understanding negative numbers. All the games discussed in the article are linked on the page and have been cataloged separately: Incy Wincy Spider, Tug of War, Swimming Pool, Tug Harder, First Connect Three and lastly Sea Level.

Woodham, Liz

2011-01-01

74

PSEUDORANDOM NUMBER GENERATORS  

Microsoft Academic Search

We review the basic principles underlying the design of uniform random number generators, their main quality requirements, their theoretical analysis, and their empirical testing. The main con- struction techniques of algorithmic generators are discussed, with an emphasis on the most com- mon ones, the linear generators. Nonlinear generators, as well as hardware-based generators, are also briefly discussed. For simulation, we

Pierre L'Ecuyer

75

Houses with Height Numbers  

NSDL National Science Digital Library

This applet allows students to freely build shapes by stacking cubes and "explore the relation between a building (house) consisting of cubes and the height numbers representing the height of the different parts of the building." This exercise helps students visualize and understand the concepts of volume and three-dimensional, measurable space.

Boon, Peter; Van Den Brink, Jan

2004-01-01

76

ALARA notes, Number 8  

SciTech Connect

This document contains information dealing with the lessons learned from the experience of nuclear plants. In this issue the authors tried to avoid the `tyranny` of numbers and concentrated on the main lessons learned. Topics include: filtration devices for air pollution abatement, crack repair and inspection, and remote handling equipment.

Khan, T.A.; Baum, J.W.; Beckman, M.C. [eds.] [eds.

1993-10-01

77

Paint by Numbers Revived!  

ERIC Educational Resources Information Center

Remember paint by numbers? This revived trend was a perfect solution to teaching geometric shapes to the author's first-grade students. Geometric shapes are identified and used in early elementary art classrooms, but this lesson gives students a deeper understanding of shape, encourages problem-solving, and makes a strong correlation between math…

Hahn, Nic

2012-01-01

78

Number and Operation Games  

NSDL National Science Digital Library

Play the counting games below. First, help Curious George juggle the fruit in the Curious George Juggling game. Next, count the fish in the Fish Counting game. Then, try to catch the correct number of fish in the net. Go Fishing! ...

Allen, Ms.

2010-10-09

79

Stability in Numbers  

NSDL National Science Digital Library

In this Illuminations lesson, students apply their knowledge of addition equations to investigate the equivalence of two numeric expressions using the "Pan Balance-Numbers" applet (cataloged separately). An instructional plan, questions for the students, assessment options, extensions, and teacher reflections are given for the lesson as well as links to the applet and a student activity sheet(word format).

Keller, Gary M.

2011-01-01

80

Introducing Complex Numbers  

ERIC Educational Resources Information Center

One of the difficulties in any teaching of mathematics is to bridge the divide between the abstract and the intuitive. Throughout school one encounters increasingly abstract notions, which are more and more difficult to relate to everyday experiences. This article examines a familiar approach to thinking about negative numbers, that is an…

Trudgian, Timothy

2009-01-01

81

Low chromosome number angiosperms  

Microsoft Academic Search

Plant with very low chromosome number are of interest for the analysis of the structure of chromosome and chromatin organization. Many studies have been carried out on the evolution of the karyotype in the An- giosperms with only two chromosomes in their haploid complement. The results of these analyses in the five An- giosperms with 2n=4 have been reported with

Cremonini Roberto

82

Uniform Random Number Generation  

Microsoft Academic Search

This chapter covers the basic design principles and methods for uniform random number generators used in simulation. We also briefly mention the connections between these methods and those used to construct highly-uniform point sets for quasi-Monte Carlo integration. The emphasis is on the methods based on linear recurrences modulo a large integer, or modulo 2. This reflects the fact that

Pierre L'Ecuyer

1993-01-01

83

Random numbers for simulation  

Microsoft Academic Search

In the mind of the average computer user, the problem of generating uniform variates by computer has been solved long ago. After all, every computer :system offers one or more function(s) to do so. Many software products, like compilers, spreadsheets, statistical or numerical packages, etc. also offer their own. These functions supposedly return numbers that could be used, for all

Pierre L'Ecuyer

1990-01-01

84

Uniform random number generators  

NASA Technical Reports Server (NTRS)

Methods are presented for the generation of random numbers with uniform and normal distributions. Subprogram listings of Fortran generators for the Univac 1108, SDS 930, and CDC 3200 digital computers are also included. The generators are of the mixed multiplicative type, and the mathematical method employed is that of Marsaglia and Bray.

Farr, W. R.

1971-01-01

85

Second grade Number Activities  

NSDL National Science Digital Library

This page provides examples of Second Grade Number (Operations and Algebraic Thinking, and Number and Operations in Base Ten) activities aligned with the Common Core State Standards. A CCSS standard is stated and the possible activities are listed below and linked. All activities are suitable for use in Math Centers, small group or whole class settings and are designed to elicit a range of responses and provide opportunities for students to communicate their reasoning and mathematical thinking. Instructions for each task are typed in large print and written in child-friendly language to enable students to work on activities independently after a brief introduction to the task. All files listed are in PDF format.

Godwin, Nicola

2012-01-01

86

First Grade Number Actiivities  

NSDL National Science Digital Library

This page provides examples of First Grade Number (Operations and Algebraic Thinking, and Number and Operations in Base Ten) activities aligned with the Common Core State Standards. A CCSS standard is stated and the possible activities are listed below and linked. All activities are suitable for use in Math Centers, small group or whole class settings and are designed to elicit a range of responses and provide opportunities for students to communicate their reasoning and mathematical thinking. Instructions for each task are typed in large print and written in child-friendly language to enable students to work on activities independently after a brief introduction to the task. All files listed are in PDF format.

Godwin, Nicola

2012-01-01

87

All About Numbers  

NSDL National Science Digital Library

In this 14-min video British teacher Rosalind Caren demonstrates group activities designed to develop number sense, fluency with addition and subtraction fact families, and reasoning skills. Caren exhibits effective questioning techniques and routines. Headteacher/math coordinator Kate Frood describes the guiding principles and expectations of teaching at the school. Following a class observation Frood provides constructive feedback to Caren and her teaching assistants.

2012-01-01

88

Is Baryon Number Conserved?  

Microsoft Academic Search

We suggest that baryon-number conservation may not be absolute and that an integrally charged quark may disintegrate into two leptons and an antilepton with a coupling strength GBmp2<~10-9. On the other hand, if quarks are much heavier than low-lying hadrons, the decay of a three-quark system like the proton is highly forbidden (proton lifetime >~ 1028 y). Motivation for these

Jogesh C. Pati; Abdus Salam

1973-01-01

89

Maths Doctor: Number  

NSDL National Science Digital Library

The Maths Doctor website from Macmillan Publishers contains more than 250 lessons that are free for anyone. Each lesson includes a three to five minute video tutorial on the topic and a related worksheet for the student to complete. Each worksheet has a convenient QR code that a student can scan to access the video. The Number section contains numerous lessons ranging from Conversion of Units to Dividing Fractions to Subtracting Negative Integers.

2014-06-20

90

A Pentagonal Number Sieve  

Microsoft Academic Search

We prove a general "pentagonal sieve" theorem that has corollaries such as the following. First, thenumber of pairs of partitions of n that have no parts in common isp(n)2\\\\Gamma p(n \\\\Gamma 1)2\\\\Gamma p(n \\\\Gamma 2)2+ p(n \\\\Gamma 5)2+ p(n \\\\Gamma 7)2\\\\Gamma : : : :Second, if two unlabeled rooted forests of the same number of vertices are chosen i.u.a.r., then

Sylvie Corteel; Carla D. Savage; Herbert S. Wilf; Doron Zeilberger

1998-01-01

91

Uniform random number generation  

Microsoft Academic Search

Abstract This chapter covers the basic design principles and methods for uniform random number,generators used in simulation. We also briefly mention the connections between these methods and those used to construct highly-uniform point sets for quasi-Monte Carlo integration. The emphasis is on the methods,based on linear recurrences modulo a large integer, or modulo 2. This reflects the fact that their

1994-01-01

92

Testing random number generators  

Microsoft Academic Search

So-called Random number generators on computersare deterministic functions producing a sequence of numberswhich should mimic a sample of i.i.d. U(0; 1) randomvariables. Two classes of tests are commonly applied tosuch generators. Firstly, the theoretical tests, which lookat the intrinsic structure of the generator to derive behavioralproperties of the sequence of points, usually overthe whole period. These theoretical tests are specific

Pierre L'Ecuyer

1992-01-01

93

Nature by Numbers  

NSDL National Science Digital Library

This 4-minute computer animation highlights three forms in nature that have connections with numbers and geometry. The Fibonacci sequence and the golden ratio are shown relating to the chambered nautilus shell and the sunflower seed pattern. The Delaunay triangulation and Voronoi tessellation are shown to simulate the capillary distribution on a dragonfly wing. Included are descriptions of the mathematics and stills from the production.

2013-02-01

94

Numerical Calculation of Two-Dimensional Natural Convection in Isothermal Open Cavities  

Microsoft Academic Search

Numerical computations of free convection flow inside an isothermal open square cavity are presented. The effects of the Grashof number and the inclination of cavity are examined. Unsteady solutions are observed for Grashof numbers larger than 100,000 and a cavity aperture facing upward.

F. Penot

1982-01-01

95

Neither Name, Nor Number  

NASA Astrophysics Data System (ADS)

Since its origins, quantum mechanics has presented problems with the concept of individuality. It is argued that quantum particles do not have individuality, and so, one can speak about "entities without identity". On the contrary, we claim that the problem of quantum non individuality goes deeper, and that one of its most important features is the fact that there are quantum systems for which particle number is not well defined. In this work, we continue this discussion in relation to the problem about the one and the many.

Holik, Federico

2014-03-01

96

Modular redundant number systems  

SciTech Connect

With the increased use of public key cryptography, faster modular multiplication has become an important cryptographic issue. Almost all public key cryptography, including most elliptic curve systems, use modular multiplication. Modular multiplication, particularly for the large public key modulii, is very slow. Increasing the speed of modular multiplication is almost synonymous with increasing the speed of public key cryptography. There are two parts to modular multiplication: multiplication and modular reduction. Though there are fast methods for multiplying and fast methods for doing modular reduction, they do not mix well. Most fast techniques require integers to be in a special form. These special forms are not related and converting from one form to another is more costly than using the standard techniques. To this date it has been better to use the fast modular reduction technique coupled with standard multiplication. Standard modular reduction is much more costly than standard multiplication. Fast modular reduction (Montgomery`s method) reduces the reduction cost to approximately that of a standard multiply. Of the fast multiplication techniques, the redundant number system technique (RNS) is one of the most popular. It is simple, converting a large convolution (multiply) into many smaller independent ones. Not only do redundant number systems increase speed, but the independent parts allow for parallelization. RNS form implies working modulo another constant. Depending on the relationship between these two constants; reduction OR division may be possible, but not both. This paper describes a new technique using ideas from both Montgomery`s method and RNS. It avoids the formula problem and allows fast reduction and multiplication. Since RNS form is used throughout, it also allows the entire process to be parallelized.

NONE

1998-05-31

97

Beyond Natural Numbers: Negative Number Representation in Parietal Cortex  

PubMed Central

Unlike natural numbers, negative numbers do not have natural physical referents. How does the brain represent such abstract mathematical concepts? Two competing hypotheses regarding representational systems for negative numbers are a rule-based model, in which symbolic rules are applied to negative numbers to translate them into positive numbers when assessing magnitudes, and an expanded magnitude model, in which negative numbers have a distinct magnitude representation. Using an event-related functional magnetic resonance imaging design, we examined brain responses in 22 adults while they performed magnitude comparisons of negative and positive numbers that were quantitatively near (difference <4) or far apart (difference >6). Reaction times (RTs) for negative numbers were slower than positive numbers, and both showed a distance effect whereby near pairs took longer to compare. A network of parietal, frontal, and occipital regions were differentially engaged by negative numbers. Specifically, compared to positive numbers, negative number processing resulted in greater activation bilaterally in intraparietal sulcus (IPS), middle frontal gyrus, and inferior lateral occipital cortex. Representational similarity analysis revealed that neural responses in the IPS were more differentiated among positive numbers than among negative numbers, and greater differentiation among negative numbers was associated with faster RTs. Our findings indicate that despite negative numbers engaging the IPS more strongly, the underlying neural representation are less distinct than that of positive numbers. We discuss our findings in the context of the two theoretical models of negative number processing and demonstrate how multivariate approaches can provide novel insights into abstract number representation.

Blair, Kristen P.; Rosenberg-Lee, Miriam; Tsang, Jessica M.; Schwartz, Daniel L.; Menon, Vinod

2012-01-01

98

Lepton family number violation  

SciTech Connect

At present there is evidence from neutrino oscillation searches that the neutrinos are in fact massive particles and that they mix. If confirmed, this would imply that the conservation of LFN is not exact. Lepton family number violation (LFNV) has been searched for with impressive sensitivities in many processes involving charged leptons. The present experimental limits on some of them (those which the author shall consider here) are shown in Table 1. These stringent limits are not inconsistent with the neutrino oscillation results since, given the experimental bounds on the masses of the known neutrinos and the neutrino mass squared differences required by the oscillation results, the effects of LFNV from neutrino mixing would be too small to be seen elsewhere (see Section 2). The purpose of experiments searching for LFNV involving the charged leptons is to probe the existence of other sources of LFNV. Such sources are present in many extensions of the SM. In this lecture the author shall discuss some of the possibilities, focusing on processes that require muon beams. Other LFNV processes, such as the decays of the kaons and of the {tau}, provide complementary information. In the next Section he shall consider some sources of LFNV that do not require an extension of the gauge group of the SM (the added leptons or Higgs bosons may of course originate from models with extended gauge groups). In Section 3 he discusses LFNV in left-right symmetric models. In Section 4 he considers LFNV in supersymmetric models, first in R-parity conserving supersymmetric grand unified models, and then in the minimal supersymmetric standard model with R-parity violation. The last section is a brief summary of the author`s conclusions.

Herczeg, P.

1999-03-01

99

Series of Reciprocal Triangular Numbers  

ERIC Educational Resources Information Center

Reciprocal triangular numbers have appeared in series since the very first infinite series were summed. Here we attack a number of subseries of the reciprocal triangular numbers by methodically expressing them as integrals.

Bruckman, Paul; Dence, Joseph B.; Dence, Thomas P.; Young, Justin

2013-01-01

100

15. Stress Sheet, Truss number 2, span number 6, Superior ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. Stress Sheet, Truss number 2, span number 6, Superior Avenue viaduct. Drawing courtesy Engineering Dept., City of Cleveland. - Superior Avenue Viaduct, Cleveland East & West side, Cuyahoga Valley Vicinity, Cleveland, Cuyahoga County, OH

101

Toddlers' Spontaneous Attention to Number and Verbal Number Quantification  

ERIC Educational Resources Information Center

"S"pontaneous "a"ttention to "n"umber (SAN) is the tendency to notice the relatively abstract attribute of number despite the presence of other attributes. According to nativists, an innate concept of one to three directs young children's attention to these "intuitive numbers" in everyday situations--even before they acquire language. According to…

Li, Xia

2009-01-01

102

Feeling Number: Grounding Number Sense in a Sense of Quantity  

ERIC Educational Resources Information Center

Drawing on results from psychology and from cultural and linguistic studies, we argue for an increased focus on developing quantity sense in school mathematics. We explore the notion of "feeling number", a phrase that we offer in a twofold sense--resisting tendencies to feel numb-er (more numb) by developing a feeling for numbers and the…

Wagner, David; Davis, Brent

2010-01-01

103

How Spencer Made Number: First Uses of the Number Words  

ERIC Educational Resources Information Center

This article describes the development of number concepts between infancy and early childhood. It is based on a diary study that tracked number word use in a child from 12 to 38 months of age. Number words appeared early in the child's vocabulary, but accurate reference to specific numerosities evolved gradually over the entire 27-month period.…

Mix, Kelly S.

2009-01-01

104

Patent Number Sequence Classification Record.  

National Technical Information Service (NTIS)

The official microfilm record lists the original and cross-reference classifications together for each patent number, in Patent number order. The record comprises all patents issued through 29 Apr 69, all reclassifications made effective through 1 Jan 69,...

1970-01-01

105

Know Your Blood Sugar Numbers  

MedlinePLUS

... Numbers If you have diabetes, keeping your blood glucose (sugar) numbers in your target range can help ... a lab test that measures your average blood glucose level over the last 2 to 3 months. ...

106

Euler Numbers on Cobordant Hypersurfaces  

NASA Astrophysics Data System (ADS)

When two hypersurfaces are mediated by a Lorentz cobordism, a homology selection rule restricts the number of general relativistic kinks that can occur on the hypersurfaces. In 2+1 dimensions, this selection rule translates to the requirement that the difference in the number of kinks on the two hypersurfaces be balanced by a corresponding difference in Euler number. This is explored for a particular spacetime by using a tetrad-based Jacobian integral formula for calculating the kink number.

Harriott, Tina A.; Williams, J. G.

2008-09-01

107

The Number Space and Neglect  

Microsoft Academic Search

Recent cognitive models of numerical abilities have postulated that number processing may in part rely on a representation of quantities where magnitude is organized by spatial proximity, along a “mental number line” extending from left to right. We describe four experiments that examined whether such a spatial representation of number would be affected by the presence of unilateral neglect after

Patrik Vuilleumier; Stéphanie Ortigue; Peter Brugger

2004-01-01

108

PLURIDICTA, Numbers 28-35.  

ERIC Educational Resources Information Center

The eight titles in this document include the following: "Comprehension and Input Processing as Useful Terms in the Field of SLA" (number 28) (Teresa Cadierno); "On the Role of Instruction in SLA: Research Results and Theoretical Explanations" (number 29) (Teresa Cadierno); "Can Writing Be Taught" (number 30) (Stuart Greene); "Academic Listening"…

Wagner, Johannes, Ed.

1998-01-01

109

Properties of Clebsch Gordan numbers  

NASA Astrophysics Data System (ADS)

Clebsch-Gordan numbers are the multiplicity numbers for the occurrence of the states of total angular momentum in the coupling of n angular momenta. These numbers are defined and completely generated by repeated application of the Clebsch-Gordan series rule. The relatiohship of this rule to Gaussian polynomials is presented for equal angular momenta.

Louck, J. D.

2008-03-01

110

Semantic processing of neglected numbers  

Microsoft Academic Search

While neglected stimuli can still be processed, few studies have directly addressed the issue of the unconscious access to semantics. In order to clarify this issue, we engaged four patients with unilateral left spatial neglect in a number comparison task. Each target number was preceded by a lateralized number prime, either in the intact or neglected hemifield (HF). Both group

Jérôme Sackur; Lionel Naccache; Pascale Pradat-Diehl; Philippe Azouvi; Dominique Mazevet; Rose Katz; Laurent Cohen; Stanislas Dehaene

2008-01-01

111

Numbers and Math. Beginnings Workshop.  

ERIC Educational Resources Information Center

Presents five articles addressing numbers and math instruction for young children: "Math Talk with Young Children: One Parent's Experience" (Fred E. Gross); "How Children Build Their Understanding of Numbers" (David Elkind); "Early Math: It's More than Numbers" (Ann S. Epstein); "Assessing Mathematical Learning: Observing and Listening to…

Gross, Fred E.; Elkind, CavidEpstein, Ann S.; Copley, Juanita V.; Haugen, Ginny; Haugen, Kirsten

2003-01-01

112

The Child's Conception of Number.  

ERIC Educational Resources Information Center

Based on the hypothesis that the construction of number is closely related to the development of logic, this book records a series of experiments investigating classes, relations, and numbers as cognitive domains. The author finds that number is organized, stage after stage, in close connection with the gradual elaboration of systems of inclusions…

Piaget, Jean

113

Random Numbers and Quantum Computers  

ERIC Educational Resources Information Center

The topic of random numbers is investigated in such a way as to illustrate links between mathematics, physics and computer science. First, the generation of random numbers by a classical computer using the linear congruential generator and logistic map is considered. It is noted that these procedures yield only pseudo-random numbers since…

McCartney, Mark; Glass, David

2002-01-01

114

Linear or Exponential Number Lines  

ERIC Educational Resources Information Center

Having decided to spend some time looking at one's understanding of numbers, the author was inspired by "Alex's Adventures in Numberland," by Alex Bellos to look at one's innate appreciation of number. Bellos quotes research studies suggesting that an individual's natural appreciation of numbers is more likely to be exponential rather than linear,…

Stafford, Pat

2011-01-01

115

What Exactly Do Numbers Mean?  

ERIC Educational Resources Information Center

Number words are generally used to refer to the exact cardinal value of a set, but cognitive scientists disagree about their meanings. Although most psychological analyses presuppose that numbers have exact semantics ("two" means exactly two), many linguistic accounts propose that numbers have lower-bounded semantics (at least two), and…

Huang, Yi Ting; Spelke, Elizabeth; Snedeker, Jesse

2013-01-01

116

Three Cubes in One Number  

ERIC Educational Resources Information Center

Separate a three-digit number into its component digits. After raising each digit to the third power and computing the sum of the cubes, determine how often the original number reappears. Modular arithmetic is used to reduce the number of potential solutions to a more manageable quantity. (Contains 4 tables.)

Jue, Brian

2010-01-01

117

Numbers and time doubly dissociate.  

PubMed

The magnitude dimensions of number, time and space have been suggested to share some common magnitude processing, which may imply symmetric interaction among dimensions. Here we challenge these suggestions by presenting a double dissociation between two neuropsychological patients with left (JT) and right (CB) parietal lesions and selective impairment of number and time processing respectively. Both patients showed an influence of task-irrelevant number stimuli on time but not space processing. In JT otherwise preserved time processing was severely impaired in the mere presence of task-irrelevant numbers, which themselves could not be processed accurately. In CB, impaired temporal estimation was influenced by preserved number processing: small numbers made (already grossly underestimated) time intervals appear even shorter relative to large numbers. However, numerical estimation was not influenced by time in healthy controls and in both patients. This new double dissociation between number and time processing and the asymmetric interaction of number on time: (1) provides further support to the hypothesis of a partly shared magnitude system among dimensions, instead of the proposal of a single, fully shared system or of independent magnitude systems which would not explain dissociations or interactions among dimensions; (2) may be explained in terms of a stable hierarchy of dimensions, with numbers being the strongest. PMID:21807010

Cappelletti, Marinella; Freeman, Elliot D; Cipolotti, Lisa

2011-09-01

118

Number in Early Childhood. Beecholme Nursery Number Project.  

ERIC Educational Resources Information Center

Two essays examine the number aspect of mathematics learning for three- to five-year olds. The first contextualizes the research and reviews its progress, focusing on how children learn in contexts where numbers occur incidentally, and on developing appropriate ways of challenging children to solve problems. The second essay presents a case study…

Gifford, Sue; Wilson, Pauline

1995-01-01

119

Chaotic Nonlinear Prime Number Function  

NASA Astrophysics Data System (ADS)

Dynamical systems in nature, such as heartbeat patterns, DNA sequence pattern, prime number distribution, etc., exhibit nonlinear (chaotic) space-time fluctuations and exact quantification of the fluctuation pattern for predictability purposes has not yet been achieved [1]. In this paper a chaotic-nonlinear prime number function P(s) is developed, from which prime numbers are generated and decoded while composite numbers are encoded over time following the Euler product methodology, which works on sequences progressively culled from multiples of the preceding primes. By relating this P(s) to a virtually closed 2D number line manifold, it is possible to represent the evolving in time of nonlinear (chaotic) systems to a final value where the system becomes stable, becomes linear. This nonlinear prime number function is proposed as a chaotic model system able to describe chaotic systems.

Mateos, Luis A.

2011-06-01

120

Familial Sinistrals Avoid Exact Numbers  

PubMed Central

We report data from an internet questionnaire of sixty number trivia. Participants were asked for the number of cups in their house, the number of cities they know and 58 other quantities. We compare the answers of familial sinistrals – individuals who are left-handed themselves or have a left-handed close blood-relative – with those of pure familial dextrals – right-handed individuals who reported only having right-handed close blood-relatives. We show that familial sinistrals use rounder numbers than pure familial dextrals in the survey responses. Round numbers in the decimal system are those that are multiples of powers of 10 or of half or a quarter of a power of 10. Roundness is a gradient concept, e.g. 100 is rounder than 50 or 200. We show that very round number like 100 and 1000 are used with 25% greater likelihood by familial sinistrals than by pure familial dextrals, while pure familial dextrals are more likely to use less round numbers such as 25, 60, and 200. We then use Sigurd’s (1988, Language in Society) index of the roundness of a number and report that familial sinistrals’ responses are significantly rounder on average than those of pure familial dextrals. To explain the difference, we propose that the cognitive effort of using exact numbers is greater for the familial sinistral group because their language and number systems tend to be more distributed over both hemispheres of the brain. Our data support the view that exact and approximate quantities are processed by two separate cognitive systems. Specifically, our behavioral data corroborates the view that the evolutionarily older, approximate number system is present in both hemispheres of the brain, while the exact number system tends to be localized in only one hemisphere.

Sauerland, Uli; Gotzner, Nicole

2013-01-01

121

Familial sinistrals avoid exact numbers.  

PubMed

We report data from an internet questionnaire of sixty number trivia. Participants were asked for the number of cups in their house, the number of cities they know and 58 other quantities. We compare the answers of familial sinistrals--individuals who are left-handed themselves or have a left-handed close blood-relative--with those of pure familial dextrals--right-handed individuals who reported only having right-handed close blood-relatives. We show that familial sinistrals use rounder numbers than pure familial dextrals in the survey responses. Round numbers in the decimal system are those that are multiples of powers of 10 or of half or a quarter of a power of 10. Roundness is a gradient concept, e.g. 100 is rounder than 50 or 200. We show that very round number like 100 and 1000 are used with 25% greater likelihood by familial sinistrals than by pure familial dextrals, while pure familial dextrals are more likely to use less round numbers such as 25, 60, and 200. We then use Sigurd's (1988, Language in Society) index of the roundness of a number and report that familial sinistrals' responses are significantly rounder on average than those of pure familial dextrals. To explain the difference, we propose that the cognitive effort of using exact numbers is greater for the familial sinistral group because their language and number systems tend to be more distributed over both hemispheres of the brain. Our data support the view that exact and approximate quantities are processed by two separate cognitive systems. Specifically, our behavioral data corroborates the view that the evolutionarily older, approximate number system is present in both hemispheres of the brain, while the exact number system tends to be localized in only one hemisphere. PMID:23544052

Sauerland, Uli; Gotzner, Nicole

2013-01-01

122

Schmidt number for quantum operations  

SciTech Connect

To understand how entangled states behave under local quantum operations is an open problem in quantum-information theory. The Jamiolkowski isomorphism provides a natural way to study this problem in terms of quantum states. We introduce the Schmidt number for quantum operations by this duality and clarify how the Schmidt number of a quantum state changes under a local quantum operation. Some characterizations of quantum operations with Schmidt number k are also provided.

Huang Siendong [Department of Applied Mathematics, National Dong Hwa University, Hualien 974, Taiwan (China)

2006-05-15

123

Random number generation and creativity.  

PubMed

A previous paper suggested that humans can generate genuinely random numbers. I tested this hypothesis by repeating the experiment with a larger number of highly numerate subjects, asking them to call out a sequence of digits selected from 0 through 9. The resulting sequences were substantially non-random, with an excess of sequential pairs of numbers and a deficit of repeats of the same number, in line with previous literature. However, the previous literature suggests that humans generate random numbers with substantial conscious effort, and distractions which reduce that effort reduce the randomness of the numbers. I reduced my subjects' concentration by asking them to call out in another language, and with alcohol - neither affected the randomness of their responses. This suggests that the ability to generate random numbers is a 'basic' function of the human mind, even if those numbers are not mathematically 'random'. I hypothesise that there is a 'creativity' mechanism, while not truly random, provides novelty as part of the mind's defence against closed programming loops, and that testing for the effects seen here in people more or less familiar with numbers or with spontaneous creativity could identify more features of this process. It is possible that training to perform better at simple random generation tasks could help to increase creativity, through training people to reduce the conscious mind's suppression of the 'spontaneous', creative response to new questions. PMID:17920778

Bains, William

2008-01-01

124

Acceptance of Others (Number Form).  

ERIC Educational Resources Information Center

As part of the instrumentation to assess the effectiveness of the Schools Without Failure (SWF) program in 10 elementary schools in the New Castle, Pa. School District, the Acceptance of Others (Number Form) was prepared to determine pupil's attitudes toward classmates. Given a list of all class members, pupils are asked to circle a number from 1…

Masters, James R.; Laverty, Grace E.

125

Extremely portable random number generator  

Microsoft Academic Search

Extremely portable subroutines are sometimes needed for which moderate quality and efficiency suffice. Typically, this occurs for library functions (like random number generation and incore sorting) which are not entirely universal or are not used in a standardized way.The literature on random number generators does not seem to contain an algorithm that meets requirements of this sort. An extremely portable

J. B. Kruskal

1969-01-01

126

Face Numbers of Scarf Complexes.  

National Technical Information Service (NTIS)

In this paper the authors study relations among the numbers fi. It is shown that fo,f1,....,f((d-3)/2) determine the other numbers via linear relations, and that there are additional non-linear relations.

A. Bjoerner

1998-01-01

127

Color by Numbers: Image Representation  

NSDL National Science Digital Library

Computers store drawings, photographs, and other pictures using only numbers. Through this activity, learners decode numbers to create pictures using the same process that computers use. They can then create and code their own pictures for other learners to decode. This lesson includes three activities (1 introductory and 2 worksheet) and background information.

Technology, National C.

2012-12-13

128

Investigating the Randomness of Numbers  

ERIC Educational Resources Information Center

The use of random numbers is pervasive in today's world. Random numbers have practical applications in such far-flung arenas as computer simulations, cryptography, gambling, the legal system, statistical sampling, and even the war on terrorism. Evaluating the randomness of extremely large samples is a complex, intricate process. However, the…

Pendleton, Kenn L.

2009-01-01

129

Number of Part D Enrollees  

Cancer.gov

The following table lists the number of persons appearing in the SEER-Medicare data who are enrolled in Medicare Part D as well as the total number of patients who were eligible to enroll according to the PEDSF file. The data are displayed by year, beginning in 2007, and by cancer site for patients with a first primary cancer.

130

Children as Apprentices to Number.  

ERIC Educational Resources Information Center

Investigated understanding and use of numerals in 48 children ages 3 and 4. Found that children rarely noticed the absence of numbers if they were not able to explain their purpose. They used several methods to represent number on notes for the milkman, party invitations, and labels. Results suggest that understanding preceded use of numerals.…

Ewers-Rogers, Jennifer; Cowan, Richard

1996-01-01

131

Toddlers' Spontaneous Attention to Number  

ERIC Educational Resources Information Center

Hannula and Lehtinen (2001, 2005) defined spontaneous focusing on numerosity (SFON) as the tendency to notice the relatively abstract attribute of number despite the presence of other attributes. According to nativists, an innate concept of one to three directs young children's attention to these "intuitive numbers" in everyday situations--even…

Baroody, Arthur J.; Li, Xia; Lai, Meng-lung

2008-01-01

132

Efficient Generation of Prime Numbers  

Microsoft Academic Search

The generation of prime numbers underlies the use of most public-key schemes, essentially as a major primitive needed for the cre- ation of key pairs or as a computation stage appearing during various cryptographic setups. Surprisingly, despite decades of intense mathemat- ical studies on primality testing and an observed progressive intensi- cation of cryptographic usages, prime number generation algorithms remain

Marc Joye; Pascal Paillier; Serge Vaudenay

2000-01-01

133

Whole Numbers - When in Rome  

NSDL National Science Digital Library

The students perform the Sieve of Eratosthenes in class to find the prime number between 1 and 100. They also look for patterns such as where the multiples of 2 or 5 appear in the sieve. At home or in a computer lab they then research the Fibonacci Sequence and other number systems.

2010-01-01

134

Spontaneous Number Representation in Mosquitofish  

ERIC Educational Resources Information Center

While there is convincing evidence that preverbal human infants and non-human primates can spontaneously represent number, considerable debate surrounds the possibility that such capacity is also present in other animals. Fish show a remarkable ability to discriminate between different numbers of social companions. Previous work has demonstrated…

Dadda, Marco; Piffer, Laura; Agrillo, Christian; Bisazza, Angelo

2009-01-01

135

Pseudo-Random Number Generators  

NASA Technical Reports Server (NTRS)

Package features comprehensive selection of probabilistic distributions. Monte Carlo simulations resorted to whenever systems studied not amenable to deterministic analyses or when direct experimentation not feasible. Random numbers having certain specified distribution characteristic integral part of simulations. Package consists of collector of "pseudorandom" number generators for use in Monte Carlo simulations.

Howell, L. W.; Rheinfurth, M. H.

1984-01-01

136

Quick Images: Visualizing Number Combinations  

NSDL National Science Digital Library

In this 6-minute video kindergarten teacher Stephanie Latimer describes and models techniques for developing children's number sense and visual recognition of number combinations. After quickly displaying groups of objects on a ten frame, she asks her students to describe the ways that they see the objects grouped. The resource includes reflection questions for viewers and a transcript of the video (doc).

2012-01-01

137

Building Buildings with Triangular Numbers  

ERIC Educational Resources Information Center

Triangular numbers are used to unravel a new sequence of natural numbers here-to-fore not appearing on the Encyclopedia of Integer Sequences website. Insight is provided on the construction of the sequence using "buildings" as a viewable model of the sequence entries. A step-by-step analysis of the sequence pattern reveals a method for generating…

Pagni, David L.

2006-01-01

138

Number Talks Build Numerical Reasoning  

ERIC Educational Resources Information Center

"Classroom number talks," five- to fifteen-minute conversations around purposefully crafted computation problems, are a productive tool that can be incorporated into classroom instruction to combine the essential processes and habits of mind of doing math. During number talks, students are asked to communicate their thinking when presenting and…

Parrish, Sherry D.

2011-01-01

139

Distance Effects in Number Agreement  

ERIC Educational Resources Information Center

One pronoun production experiment and one pronoun comprehension experiment were performed to investigate the role of grammatical number information in long-distance anaphora, with referent and pronoun either in adjacent sentences or separated by an intervening sentence. The experiments tested the assumption that the influence of grammatical number

Schweppe, Judith

2013-01-01

140

An Experimental Investigation of Natural Convection in a Horizontal Cylinder.  

National Technical Information Service (NTIS)

The study deals with an experimental investigation into the natural convection inside a horizontal cylinder. The fluid, geometry, and thermal boundary condition were chosen so as to have a high Prandtl number and unit order Grashof number. The thermal bou...

I. H. Brooks S. Ostrach

1969-01-01

141

Reynolds number influences in aeronautics  

NASA Technical Reports Server (NTRS)

Reynolds number, a measure of the ratio of inertia to viscous forces, is a fundamental similarity parameter for fluid flows and therefore, would be expected to have a major influence in aerodynamics and aeronautics. Reynolds number influences are generally large, but monatomic, for attached laminar (continuum) flow; however, laminar flows are easily separated, inducing even stronger, non-monatomic, Reynolds number sensitivities. Probably the strongest Reynolds number influences occur in connection with transitional flow behavior. Transition can take place over a tremendous Reynolds number range, from the order of 20 x 10(exp 3) for 2-D free shear layers up to the order of 100 x 10(exp 6) for hypersonic boundary layers. This variability in transition behavior is especially important for complex configurations where various vehicle and flow field elements can undergo transition at various Reynolds numbers, causing often surprising changes in aerodynamics characteristics over wide ranges in Reynolds number. This is further compounded by the vast parameterization associated with transition, in that any parameter which influences mean viscous flow development (e.g., pressure gradient, flow curvature, wall temperature, Mach number, sweep, roughness, flow chemistry, shock interactions, etc.), and incident disturbance fields (acoustics, vorticity, particulates, temperature spottiness, even electro static discharges) can alter transition locations to first order. The usual method of dealing with the transition problem is to trip the flow in the generally lower Reynolds number wind tunnel to simulate the flight turbulent behavior. However, this is not wholly satisfactory as it results in incorrectly scaled viscous region thicknesses and cannot be utilized at all for applications such as turbine blades and helicopter rotors, nacelles, leading edge and nose regions, and High Altitude Long Endurance and hypersonic airbreathers where the transitional flow is an innately critical portion of the problem.

Bushnell, Dennis M.; Yip, Long P.; Yao, Chung-Sheng; Lin, John C.; Lawing, Pierce L.; Batina, John T.; Hardin, Jay C.; Horvath, Thomas J.; Fenbert, James W.; Domack, Christopher S.

1993-01-01

142

Numbered nasal discs for waterfowl  

USGS Publications Warehouse

Numbered nasal discs were successfully used in studies requiring large numbers of individually marked waterfowl. The procedure for constructing these discs is outlined. Blue-winged teal (Anas discors) with 5/8-inch discs, and canvasback (Aythya valisineria) and redhead (A. americana) with 3/4-inch discs can be individually identified up to 50 and 80 yards, respectively, with a gunstock-mounted, 20-power spotting scope. The particular value of these markers is their durability, the number of combinations possible, and the apparent absence of behavioral or mortality influence among such species as the blue-winged teal.

Bartonek, J. C.; Dane, C. W.

1964-01-01

143

Poison control center - emergency number  

MedlinePLUS

... ANYWHERE IN THE UNITED STATES This national hotline number will let you talk to experts in poisoning. This is a free and confidential service. All local poison control centers in the United States use this national ...

144

4th Grade Number Activities  

NSDL National Science Digital Library

This page provides examples of 4th Grade Number (Operations and Algebraic Thinking, Number and Operations in Base Ten, and Number Operations-Fractions) activities aligned with the Common Core State Standards. A CCSS standard is stated and the possible activities are listed below and linked. All activities are suitable for use in Math Centers, small group or whole class settings and are designed to elicit a range of responses and provide opportunities for students to communicate their reasoning and mathematical thinking. Instructions for each task are typed in large print and written in child-friendly language to enable students to work on activities independently after a brief introduction to the task. All files for the 4th Grade Number Activities listed are in PDF format.

Godwin, Nicola

2012-01-01

145

5th Grade Number Activities  

NSDL National Science Digital Library

This page provides examples of 5th Grade Number (Operations and Algebraic Thinking, Number and Operations in Base Ten, and Number Operations-Fractions) activities aligned with the Common Core State Standards. A CCSS standard is stated and the possible activities are listed below and linked. All activities are suitable for use in Math Centers, small group or whole class settings and are designed to elicit a range of responses and provide opportunities for students to communicate their reasoning and mathematical thinking. Instructions for each task are typed in large print and written in child-friendly language to enable students to work on activities independently after a brief introduction to the task. All files for the 5th Grade Number Activities listed are in PDF format.

Godwin, Nicola

2012-01-01

146

Integral Presentations of Catalan Numbers  

ERIC Educational Resources Information Center

We compute in three different ways the same definite parametric integral. By-products are the derivation of a combinatorial identity and two integral presentations of Catalan numbers. One of them leads to a presentation using the [gamma] function.

Dana-Picard, Thierry

2010-01-01

147

Critical Marangoni Number (TEXUS 5).  

National Technical Information Service (NTIS)

The Technological Experiments Under Microgravity (TEXUS) 5 experiment to determine the transition from steady to oscillatory Marangoni flow in a floating zone corresponding to a critical Marangoni number is summarized. A cylindrical sample of NaNO3 (diame...

D. Schwabe A. Scharmann

1991-01-01

148

Microcomputer Unit: Generating Random Numbers.  

ERIC Educational Resources Information Center

Presents an activity, suitable for students in grades 6-12, on generating random numbers. Objectives, equipment needed, list of prerequisite experiences, instructional strategies, and ready-to-copy student worksheets are included. (JN)

Haigh, William E.

1986-01-01

149

Building Numbers Up to 10  

NSDL National Science Digital Library

"Students will: Construct groups of 0 to 10 objects Identify and write the numerals 0 to 10 Record the number of objects in groups of size 0 to 10" (from NCTM Illuminations) Lesson one of a six lesson unit.

Nctm, Grace M.

2012-01-17

150

Number Theory (MathPages)  

NSDL National Science Digital Library

This site includes materials on a variety of topics relating to general number theory. Each link provides a short example that would provide helpful supplemental materials in mathematics education. The lessons vary from simple algebra to more advanced topics.

Brown, Kevin

2011-01-07

151

The number of neutrino species  

Microsoft Academic Search

The authors review the methods used before the operation of the high energy Stanford and CERN e+e- colliders to determine the number of neutrino species Nnu, or an upper limit on this number, within the framework of the Standard Model of light stable neutrinos interacting according to the SU(2)×U(1) universal couplings. The astrophysical limit based on the neutrino burst from

Daniel Denegri; Bernard Sadoulet; Michel Spiro

1990-01-01

152

Why are airport runways numbered?  

NSDL National Science Digital Library

This Figure This! activity provides students an opportunity to apply their knowledge of angles and compass directions to solve a problem in the context of airport runways. The introduction calls students' attention to the numbers assigned to both ends of runways. Students are asked to find a missing runway number. The activity includes links to a solution hint, the solution, related math questions, and additional resources.

2012-01-01

153

Digital random-number generator  

NASA Technical Reports Server (NTRS)

For binary digit array of N bits, use N noise sources to feed N nonlinear operators; each flip-flop in digit array is set by nonlinear operator to reflect whether amplitude of generator which feeds it is above or below mean value of generated noise. Fixed-point uniform distribution random number generation method can also be used to generate random numbers with other than uniform distribution.

Brocker, D. H.

1973-01-01

154

Copy number variation and mutation  

NASA Astrophysics Data System (ADS)

Until very recently, the standard model of DNA included two genes for each trait. This dated model has given way to a model that includes copies of some genes well in excess of the canonical two. Copy number variations in the human genome play critical roles in causing or aggravating a number of syndromes and diseases while providing increased resistance to others. We explore the role of mutation, crossover, inversion, and reproduction in determining copy number variations in a numerical simulation of a population. The numerical model consists of a population of individuals, where each individual is represented by a single strand of DNA with the same number of genes. Each gene is initially assigned to one of two traits. Fitness of the individual is determined by the two most fit genes for trait one, and trait two genetic material is treated as a reservoir of junk DNA. After a sufficient number of generations, during which the genetic distribution is allowed to reach a steady-state, the mean numberof genes per trait and the copy number variation are recorded. Here, we focus on the role of mutation and compare simulation results to theory.

Clark, Brian; Weidner, Jacob; Wabick, Kevin

2009-11-01

155

Mass Transfer with Chemical Reaction on Flow Past an Accelerated Vertical Plate with Variable Temperature and Thermal Radiation  

NASA Astrophysics Data System (ADS)

An exact solution of an unsteady radiative flow past a uniformly accelerated infinite vertical plate with variable temperature and mass diffusion is presented here, taking into account the homogeneous chemical reaction of first order. The plate temperature as well as concentration near the plate is raised linearly with time. The dimensionless governing equations are solved using the Laplace-transform technique. The velocity, temperature and concentration fields are studied for different physical parameters such as the thermal Grashof number, mass Grashof number, Schmidt number, Prandtl number, radiation parameter, chemical reaction parameter and time. It is observed that the velocity increases with increasing values of the thermal Grashof number or mass Grashof number. But the trend is just reversed with respect to the thermal radiation parameter. It is also observed that the velocity increases with the decreasing chemical reaction parameter

Muthucumaraswamy, R.; Balachandran, P.; Ganesan, K.

2013-08-01

156

Are Number Gestures Easier than Number Words for Preschoolers?  

ERIC Educational Resources Information Center

Some researchers have argued that children's earliest symbols are based on their sensorimotor experience and that arbitrary symbol-referent mapping poses a challenge for them. If so, exposure to iconic symbols (such as one-finger-for-one-object manual gestures) might help children in a difficult domain such as number. We assessed 44 preschoolers'…

Nicoladis, Elena; Pika, Simone; Marentette, Paula

2010-01-01

157

Number Meaning and Number Grammar in English and Spanish  

ERIC Educational Resources Information Center

Grammatical agreement makes different demands on speakers of different languages. Being widespread in the languages of the world, the features of agreement systems offer valuable tests of how language affects deep-seated domains of human cognition and categorization. Number agreement is one such domain, with intriguing evidence that typological…

Bock, Kathryn; Carreiras, Manuel; Meseguer, Enrique

2012-01-01

158

Low magnetic Prandtl number dynamos  

NASA Astrophysics Data System (ADS)

Dynamo amplification by velocity fields in conducting fluids can be highly varied. Here [1] we study dynamos numerically in one of the most efficient flows found for exciting dynamo fields at low magnetic Reynolds numbers: ``Roberts flow,'' in which the large scales are driven helically in 3D periodic boundary conditions. Three qualitatively distinct regimes are identified, depending upon mechanical Reynolds number: steady-state laminar flow, mildly unstable periodic hydrodynamic flow, and fully turbulent hydrodynamic flow. A critical magnetic Reynolds number for dynamo amplification can be identified in all three regimes, and it plateaus as the inverse magnetic Prandtl number increases (paralleling earlier results for the ``Taylor-Green vortex'' flow). It is over five times higher in the turbulent velocity field regime than it is for the time-averaged flow for that turbulent velocity field. Explorations are carried out both in the linear (``kinematic dynamo'') and nonlinear regimes of incompressible MHD. Periodic boundary conditions appear as an undesirable limitation and we are attempting to dispense with them by a spectral method in which the fields are expanded in Chandrasekhar-Kendall spherical eigenfunctions of the curl. [1] P.D. Mininni and D.C. Montgomery, ``Low magnetic Prandtl number dynamos with helical forcing,'' submitted to Phys. Rev. E (2005). Arxiv: physics/0505192.

Montgomery, David; Mininni, Pablo

2005-11-01

159

Concurrent Prime Number Test Model  

NSDL National Science Digital Library

The Concurrent Prime Number Test Model uses the trial division algorithm to decide if a number is prime.  The prime division algorithm is inefficient and we use it here only to test the EJS implementation of the Parallel Region Element in EJS.  A parallel region executes independent code in threads that execute simultaneously on a multi-core processor.  The screen capture shows that the total execution time for four computations on a quad-core processor is only one millisecond longer than the execution time for the longest single computation.  This linear speedup is close to the theoretical maximum. The Concurrent Prime Number Test 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 model's jar file will run the simulation if Java is installed.

Christian, Wolfgang

2012-01-19

160

Experimental determination of Ramsey numbers.  

PubMed

Ramsey theory is a highly active research area in mathematics that studies the emergence of order in large disordered structures. Ramsey numbers mark the threshold at which order first appears and are extremely difficult to calculate due to their explosive rate of growth. Recently, an algorithm that can be implemented using adiabatic quantum evolution has been proposed that calculates the two-color Ramsey numbers R(m,n). Here we present results of an experimental implementation of this algorithm and show that it correctly determines the Ramsey numbers R(3,3) and R(m,2) for 4?m?8. The R(8,2) computation used 84 qubits of which 28 were computational qubits. This computation is the largest experimental implementation of a scientifically meaningful adiabatic evolution algorithm that has been done to date. PMID:24116761

Bian, Zhengbing; Chudak, Fabian; Macready, William G; Clark, Lane; Gaitan, Frank

2013-09-27

161

2.NBT Largest Number Game  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Dona had cards with the numbers 0 to 9 written on them. She flipped over three of them. Her teacher said: If those three numbers are the digits in anot...

162

Chromosome numbers in Compositae. XVIII.  

PubMed

Chromosome numbers and other cytogenetic data were determined from microsporocytes in 316 collections including 13 tribes of Compositae, mostly from Africa, Australia, Mexico, Central America, and South America. First reports are provided for 66 species and the genera Cassinia (2n ? 14(II)), Feldstonia (2n = 11(II)), Gochnatia (2n ? 23(II)), and Pseudoconyza (n = 10). In addition, new chromosome numbers are established at the generic level in Acourtia, Calea, Craspedia, Gnaphalium, Helipterum, Liabum, Leucheria, Smallanthus, Trixis, and Viguiera and at the specific level in 13 additional species. PMID:10406724

Carr, G D; King, R M; Powell, A M; Robinson, H

1999-07-01

163

Biotechnology at low Reynolds numbers.  

PubMed Central

The shrinking of liquid handling systems to the micron and submicron size range entails moving into the area of small Reynolds numbers. The fluid dynamics in this regime are very different from the macroscale. We present an intuitive explanation of how the different physics of small Reynolds numbers flow, along with microscopic sizes, can influence device design, and give examples from our own work using fluid flow in microfabricated devices designed for biological processing. Images FIGURE 1 FIGURE 9 FIGURE 10 FIGURE 11 FIGURE 12 FIGURE 13

Brody, J P; Yager, P; Goldstein, R E; Austin, R H

1996-01-01

164

1.OA Equality Number Sentences  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Compare the number of circles in each box. If they are equal, write a number sentence. For example: 4+3=5+1+1 If they are not equal, write "not equal."...

165

Effective carbon number molecular weight carbon number Pressure Temperature  

Microsoft Academic Search

A method based on the effective carbon number (ECN) has been developed for the prediction of the vapor pressures of carboxylic acids over a range of temperatures. Good representation of the vapor pressures is obtained in the range 1 kPa to HOkPa with an overall average absolute deviation of 2.26%for 31 carboxylic acids which included saturated as well as unsaturated

RUPERT DlSOUZA; AMYN S. TEJA

1987-01-01

166

Are prime numbers regularly ordered?  

NASA Astrophysics Data System (ADS)

The form of the prime number distribution function has withstood the efforts of all the mathematicians that have considered it. Here we address this problem with the tools of chaotic dynamics and find that, from a physical point of view, this distribution function is chaotic.

Gamba, Z.; Hernando, J.; Romanelli, L.

1990-04-01

167

Residual number processing in dyscalculia.  

PubMed

Developmental dyscalculia - a congenital learning disability in understanding numerical concepts - is typically associated with parietal lobe abnormality. However, people with dyscalculia often retain some residual numerical abilities, reported in studies that otherwise focused on abnormalities in the dyscalculic brain. Here we took a different perspective by focusing on brain regions that support residual number processing in dyscalculia. All participants accurately performed semantic and categorical colour-decision tasks with numerical and non-numerical stimuli, with adults with dyscalculia performing slower than controls in the number semantic tasks only. Structural imaging showed less grey-matter volume in the right parietal cortex in people with dyscalculia relative to controls. Functional MRI showed that accurate number semantic judgements were maintained by parietal and inferior frontal activations that were common to adults with dyscalculia and controls, with higher activation for participants with dyscalculia than controls in the right superior frontal cortex and the left inferior frontal sulcus. Enhanced activation in these frontal areas was driven by people with dyscalculia who made faster rather than slower numerical decisions; however, activation could not be accounted for by response times per se, because it was greater for fast relative to slow dyscalculics but not greater for fast controls relative to slow dyscalculics. In conclusion, our results reveal two frontal brain regions that support efficient number processing in dyscalculia. PMID:24266008

Cappelletti, Marinella; Price, Cathy J

2013-01-01

168

Residual number processing in dyscalculia?  

PubMed Central

Developmental dyscalculia – a congenital learning disability in understanding numerical concepts – is typically associated with parietal lobe abnormality. However, people with dyscalculia often retain some residual numerical abilities, reported in studies that otherwise focused on abnormalities in the dyscalculic brain. Here we took a different perspective by focusing on brain regions that support residual number processing in dyscalculia. All participants accurately performed semantic and categorical colour-decision tasks with numerical and non-numerical stimuli, with adults with dyscalculia performing slower than controls in the number semantic tasks only. Structural imaging showed less grey-matter volume in the right parietal cortex in people with dyscalculia relative to controls. Functional MRI showed that accurate number semantic judgements were maintained by parietal and inferior frontal activations that were common to adults with dyscalculia and controls, with higher activation for participants with dyscalculia than controls in the right superior frontal cortex and the left inferior frontal sulcus. Enhanced activation in these frontal areas was driven by people with dyscalculia who made faster rather than slower numerical decisions; however, activation could not be accounted for by response times per se, because it was greater for fast relative to slow dyscalculics but not greater for fast controls relative to slow dyscalculics. In conclusion, our results reveal two frontal brain regions that support efficient number processing in dyscalculia.

Cappelletti, Marinella; Price, Cathy J.

2013-01-01

169

Adjuncts Build Strength in Numbers  

ERIC Educational Resources Information Center

When professors in positions that offer no chance of earning tenure begin to stack the faculty, campus dynamics start to change. Growing numbers of adjuncts make themselves more visible. They push for roles in governance, better pay and working conditions, and recognition for work well done. And they do so at institutions where tenured faculty,…

June, Audrey Williams

2012-01-01

170

Number Program for Primary Schoolers.  

ERIC Educational Resources Information Center

The arithmetic portion of the Developing Mathematical Processes (DMP) program, as it applies to children of ages 5 to 8, is described in some detail. The terminal objective of the number program of the primary segment of DMP is the ability of the child to correctly write, read and validate mathematical sentences of the form A = B plus or minus X.…

Moser, James M.

171

Automatic Number Plate Recognition System  

Microsoft Academic Search

Automatic recognition of car license plate number became a very important in our daily life because of the unlimited increase of cars and transportation systems which make it impossible to be fully managed and monitored by humans, examples are so many like traffic monitoring, tracking stolen cars, managing parking toll, red-light violation enforcement, border and customs checkpoints. Yet it's a

Amr Badr; Mohamed Mahmoud Abd El-Wahab; Ahmed M. Thabet

2011-01-01

172

The elephant brain in numbers  

PubMed Central

What explains the superior cognitive abilities of the human brain compared to other, larger brains? Here we investigate the possibility that the human brain has a larger number of neurons than even larger brains by determining the cellular composition of the brain of the African elephant. We find that the African elephant brain, which is about three times larger than the human brain, contains 257 billion (109) neurons, three times more than the average human brain; however, 97.5% of the neurons in the elephant brain (251 billion) are found in the cerebellum. This makes the elephant an outlier in regard to the number of cerebellar neurons compared to other mammals, which might be related to sensorimotor specializations. In contrast, the elephant cerebral cortex, which has twice the mass of the human cerebral cortex, holds only 5.6 billion neurons, about one third of the number of neurons found in the human cerebral cortex. This finding supports the hypothesis that the larger absolute number of neurons in the human cerebral cortex (but not in the whole brain) is correlated with the superior cognitive abilities of humans compared to elephants and other large-brained mammals.

Herculano-Houzel, Suzana; Avelino-de-Souza, Kamilla; Neves, Kleber; Porfirio, Jairo; Messeder, Debora; Mattos Feijo, Larissa; Maldonado, Jose; Manger, Paul R.

2014-01-01

173

The elephant brain in numbers.  

PubMed

What explains the superior cognitive abilities of the human brain compared to other, larger brains? Here we investigate the possibility that the human brain has a larger number of neurons than even larger brains by determining the cellular composition of the brain of the African elephant. We find that the African elephant brain, which is about three times larger than the human brain, contains 257 billion (10(9)) neurons, three times more than the average human brain; however, 97.5% of the neurons in the elephant brain (251 billion) are found in the cerebellum. This makes the elephant an outlier in regard to the number of cerebellar neurons compared to other mammals, which might be related to sensorimotor specializations. In contrast, the elephant cerebral cortex, which has twice the mass of the human cerebral cortex, holds only 5.6 billion neurons, about one third of the number of neurons found in the human cerebral cortex. This finding supports the hypothesis that the larger absolute number of neurons in the human cerebral cortex (but not in the whole brain) is correlated with the superior cognitive abilities of humans compared to elephants and other large-brained mammals. PMID:24971054

Herculano-Houzel, Suzana; Avelino-de-Souza, Kamilla; Neves, Kleber; Porfírio, Jairo; Messeder, Débora; Mattos Feijó, Larissa; Maldonado, José; Manger, Paul R

2014-01-01

174

Belief functions on real numbers  

Microsoft Academic Search

We generalize the TBM (transferable belief model) to the case where the frame of discernment is the extended set of real numbers R = (1 ,1), under the assumptions that 'masses' can only be given to intervals. Masses become densities, belief functions, plausibility functions and commonality functions become integrals of these densities and pignistic probabilities become pignistic densities. The mathematics

Philippe Smets

2005-01-01

175

Measuring the approximate number system  

Microsoft Academic Search

Recent theories in numerical cognition propose the existence of an approximate number system (ANS) that supports the representation and processing of quantity information without symbols. It has been claimed that this system is present in infants, children, and adults, that it supports learning of symbolic mathematics, and that correctly harnessing the system during tuition will lead to educational benefits. Various

Camilla Gilmore; Nina Attridge; Matthew Inglis

2011-01-01

176

Materiales. Numbers 21-23.  

ERIC Educational Resources Information Center

These three journals of contemporary cultural, historical, and social interest contain activities designed to enhance the awareness of students of Spanish as a foreign language regarding the entire panorama of daily life in Spain. Number 21 focuses on the role of modern Spanish women; their career status; female authors; and the changing place of…

Materiales, 1997

1997-01-01

177

Statistical Treatment of Nominal Numbers.  

National Technical Information Service (NTIS)

An attempt is made to find an answer to Lord's parable of the football numbers by demonstrating that he ignored the well known principle that a measurement operation should be consistent over allowable transformations of scale. An example is given to demo...

D. R. Harris

1971-01-01

178

Parallel controlled conspiracy number search  

Microsoft Academic Search

Tree search algorithms play an important role in many applications in the field of artificial intelligence. When playing board games like chess etc., computers use game tree search algorithms to evaluate a position. In this paper, we present a procedure that we call Parallel Controlled Conspiracy Number Search (Parallel CCNS). Shortly, we describe the principles of the sequential CCNS algorithm,

Ulf Lorenz

2001-01-01

179

Prandtl number of toroidal plasmas.  

National Technical Information Service (NTIS)

Theory of the L-mode confinement in toroidal plasmas is developed. The Prandtl number, the ratio between the ion viscosity and the thermal conductivity is obtained for the anomalous transport process which is caused by the self-sustained turbulence in the...

K. Itoh S. Itoh A. Fukuyama M. Yagi M. Azumi

1993-01-01

180

Solar System Number-Crunching.  

ERIC Educational Resources Information Center

Defines terrestrial and Jovian planets and provides directions to obtain planetary data from the National Space Science Data Center Web sites. Provides "number-crunching" activities for the terrestrial planets using Texas Instruments TI-83 graphing calculators: computing volumetric mean radius and volume, density, ellipticity, speed, surface…

Albrecht, Bob; Firedrake, George

1997-01-01

181

Gummy vs. Gum (Number Pattern)  

NSDL National Science Digital Library

"In this lesson, students use gummy bears and sticks of gum to discover a number pattern and write an equation that describes it. This lesson should be conducted after students have worked with patterns and one- and two-step equations." from the Beacon Learning Center.

Center, Beacon L.

2009-10-13

182

Materiales. Numbers 17-20.  

ERIC Educational Resources Information Center

Four booklets present articles on Spanish language and culture aimed at teachers of Spanish in the United States for student use in their classes. Number 17, "Los Jovenes Espanoles" (Spanish Youth), includes articles on Spanish youth sports, music, gangs, thoughts, and t-shirt slogans: (1) "Young Spanish Athletes"; (2) "Youth Music"; (3) "Urban…

Materiales, 1995

1995-01-01

183

Number Sentences, Equations and Inequalities.  

ERIC Educational Resources Information Center

This booklet, one of a series, has been developed for the project, A Program for Mathematically Underdeveloped Pupils. A project team, including inservice teachers, is being used to write and develop the materials for this program. The materials developed in this booklet include (1) number expressions, (2) symbols and ideas, (3) open equations,…

Foley, Jack L.

184

Behavioral Science Memorandum Number 10.  

ERIC Educational Resources Information Center

Behavioral Science Memorandum Number 10 was the initial venture into annotating selected books, articles, and monographs for the guidance of busy instructors responsible for teacher education. The responses to the annotated bibliographies have been positive. Apparently some sort of handbook for learning through guided discovery is a possible means…

McGuire, Carson

185

Oxidation Numbers and Their Limitations.  

ERIC Educational Resources Information Center

Reviews a method for determining oxidation numbers in covalent compounds and balancing mixed organic-inorganic or purely organic systems. Points out ambiguities presented when adjacent atoms have small or zero electronegativity differences. Presents other limitations that arise when using electronegativity values. (CW)

Woolf, A. A.

1988-01-01

186

Low magnetic Prandtl number dynamos  

Microsoft Academic Search

Dynamo amplification by velocity fields in conducting fluids can be highly varied. Here [1] we study dynamos numerically in one of the most efficient flows found for exciting dynamo fields at low magnetic Reynolds numbers: ``Roberts flow,'' in which the large scales are driven helically in 3D periodic boundary conditions. Three qualitatively distinct regimes are identified, depending upon mechanical Reynolds

David Montgomery; Pablo Mininni

2005-01-01

187

Time to Make the Numbers  

ERIC Educational Resources Information Center

In order to inspire her students to work in mixed media, the author chose to highlight the art of Jasper Johns and Robert Indiana, both of whom used numbers and letters as a main focus in their art. In this article, the author describes a mixed-media printmaking project. (Contains 2 online resources.)

Surrena, Michelle

2011-01-01

188

Number Crunching: A Sheep's Tale  

ERIC Educational Resources Information Center

In this article, the author talks about an allegorical tale which he has written as a message for teachers of mathematics. The story is about Gordon, who led a flock of small sheep. Gordon was a mathematics genius; however, his flock criticized his teaching of numbers and his boring lectures. His furry-god-farmer advised him to share his…

Sam, Chris Lam

2005-01-01

189

What very small numbers mean  

Microsoft Academic Search

This article presents a theoretical and experimental framework for assessing the biases associated with the interpretation of numbers. This framework consists of having participants convert between different representations of quantities. These representations should include both variations in numerical labels that symbolize quantities and variations in displays in which quantity is inherent. Five experiments assessed how people convert between relative frequencies,

Dale J. Cohen; Jennifer M. Ferrell; Nathan Johnson

2002-01-01

190

The conceptual representation of number.  

PubMed

The experiments reported here investigated the format of plural conceptual representations using a picture-matching paradigm. In Experiment 1, participants read sentences that ended with a singular noun phrase (NP), a two-quantified plural NP, or a plural definite description [The parents handed the child the (two) crayon/s] and then saw a picture of one or multiple referents for the NP. Judgement times to confirm that there was overlap between the pictured object(s) and a noun in the sentence showed an interaction between the NP's number and NP-picture match. For singular NPs and two-quantified NPs, participants were reliably faster to respond "yes" to a picture that had the exact number of objects specified by the NP, but for plural definite descriptions, the effect of the number of pictured items was not reliable. Experiment 2 extended this finding to conceptual plurals. Participants read sentences biased toward either a collective (Together the men carried a box-box is interpreted as singular) or distributed (Each of the men carried a box-box is likely interpreted as plural) reading. Experiment 2 showed the same interaction between NP conceptual plurality and NP-picture match as that in Experiment 1. These results suggest that: (a) our default conceptual representations for plural definite descriptions are no more similar to images of small sets of multiple items than to images of singular items; and (b) the difference between singular and plural conceptual representations is unlikely to be simply the presence or absence of a plural feature. The results are consistent with theories in which plurality is unmarked, such that some plural NPs can refer to singular referents [e.g., Sauerland, U., Anderssen, J., & Yatsushiro, J. (2005). The plural is semantically unmarked. In S. Kepser & M. Reis (Eds.), Linguistic evidence (pp. 413-434). Berlin: de Gruyter]. PMID:24251989

Patson, Nikole D; George, Gerret; Warren, Tessa

2014-07-01

191

High-Mach-number combustion  

SciTech Connect

Recent developments in the mathematical theory of high-Mach-number combustion are presented. The phenomena in this regime are enormously complex and the mechanisms responsible for the variety of physical phenomena are poorly understood. The current advances in the mathematical theory combine asymptotic methods, careful numerics, qualitative modelling, and rigorous proofs for important model problems as well as an interplay with the documented experimental literature. This paper attempts to retain the flavor of these research efforts. Partial contents: The Theory and Structure for Planar Detonation Waves and an Instructive Qualitative Model; Quantitative Asymptotic Modelling of Nonlinear Wave - Kinetic Interactions in Reacting Gases; Instabilities in Detonations and Complex Wave Bifurcations.

Majda

1986-01-01

192

An Efficient Hardware Random Number Generator  

Microsoft Academic Search

A hardware random number generator is different from a pseudo -random number generator; a pseudo random number generator approximates the assumed behavior of a real hardware random number generator. Simple pseudo random number generators suffices for most applications, however for demanding situations such as the generation of cryptographic keys requires an efficient and a cost effective source of random numbers.

D. C. Ranasinghe; Daihyun Limb; Srinivas Devadas; Behnam Jamali; Zeng Zhu; Peter H. Cole

193

The number of neutrino species  

NASA Astrophysics Data System (ADS)

The authors review the methods used before the operation of the high energy Stanford and CERN e+e- colliders to determine the number of neutrino species N?, or an upper limit on this number, within the framework of the Standard Model of light stable neutrinos interacting according to the SU(2)×U(1) universal couplings. The astrophysical limit based on the neutrino burst from supernova 1987A is discussed first, followed by a discussion of the cosmological constraint based on the observed He/H abundance ratio. Finally, the particle physics methods based on single-photon production in e+e- collisions, on the production of monojets in pp¯ collisions, and on the determination of N? from the ratio of the W-->l?¯ to Z0-->ll¯ partial cross sections in pp¯ collisions are discussed. The various sources of uncertainty and the experimental backgrounds are presented, as well as an idea of what may be expected on this subject in the future. There is a remarkable agreement between the various methods, with central values for N? between 2 and 3 and with upper limits N?<6. Combining all determinations, the authors obtain a central value N?=2.1+0.6-0.4 for mtop=50 GeV/c2 and N?=2.0+0.6-0.4 if mtop>=mW. The results are perfectly compatible with the a priori knowledge that at least three families of neutrinos should exist. The observed consistency between this a priori knowledge, the laboratory determinations of N?, and determinations from SN 1987A and cosmology represent an astounding success for the Standard Model and for the current descriptions of stellar collapse and the Big-Bang primordial nucleosynthesis. These results, however, severely limit the number of additional families. Although the consistency is significantly worse, four families still provide a reasonable fit. In the framework of the Standard Model, a fifth light neutrino is, however, unlikely. A noted added in proof summarizes the results recently obtained at the Fermilab p¯p and the Stanford and CERN e+e- colliders which confirm these conclusions.

Denegri, D.; Sadoulet, B.; Spiro, M.

1990-01-01

194

Indexing the approximate number system.  

PubMed

Much recent research attention has focused on understanding individual differences in the approximate number system, a cognitive system believed to underlie human mathematical competence. To date researchers have used four main indices of ANS acuity, and have typically assumed that they measure similar properties. Here we report a study which questions this assumption. We demonstrate that the numerical ratio effect has poor test-retest reliability and that it does not relate to either Weber fractions or accuracy on nonsymbolic comparison tasks. Furthermore, we show that Weber fractions follow a strongly skewed distribution and that they have lower test-retest reliability than a simple accuracy measure. We conclude by arguing that in the future researchers interested in indexing individual differences in ANS acuity should use accuracy figures, not Weber fractions or numerical ratio effects. PMID:24361686

Inglis, Matthew; Gilmore, Camilla

2014-01-01

195

Copy number variations among silkworms  

PubMed Central

Background Copy number variations (CNVs), which are important source for genetic and phenotypic variation, have been shown to be associated with disease as well as important QTLs, especially in domesticated animals. However, little is known about the CNVs in silkworm. Results In this study, we have constructed the first CNVs map based on genome-wide analysis of CNVs in domesticated silkworm. Using next-generation sequencing as well as quantitative PCR (qPCR), we identified ~319 CNVs in total and almost half of them (~ 49%) were distributed on uncharacterized chromosome. The CNVs covered 10.8 Mb, which is about 2.3% of the entire silkworm genome. Furthermore, approximately 61% of CNVs directly overlapped with SDs in silkworm. The genes in CNVs are mainly related to reproduction, immunity, detoxification and signal recognition, which is consistent with the observations in mammals. Conclusions An initial CNVs map for silkworm has been described in this study. And this map provides new information for genetic variations in silkworm. Furthermore, the silkworm CNVs may play important roles in reproduction, immunity, detoxification and signal recognition. This study provided insight into the evolution of the silkworm genome and an invaluable resource for insect genomics research.

2014-01-01

196

Isotopic Randomness and Omega Number  

NASA Astrophysics Data System (ADS)

While absolute ("true") randomness is perhaps Godel undecidable (undefinable in closed form), in practice it is often measured by the information content needed to describe (explicit or implicit) pattern (e.g., Shannon entropy, S). Like stars on the sky (are they "random" or form "constellations"?), stable isotopes in crystals form patterns. Informational patterning through correlated neutron tunneling (CNT, Berezin, 1992) indicates limitations of traditional statistics based on "democratic" (ergodic) counting of available configurations. Isotopic systems of finite size may be governed by informational attractor with infinite S (of countable or uncountable cardinality, in the sense of Cantor's "alephs"). Furthermore, like "Omega Number" (G.Chaitin), true structure of this S may even be ultimately unknowable. Such "unknowability", however, does not preclude said attractor from pattern-forming capacity. Infinite sets (IS) are not confined to classical probabilities, e.g., IS of all integers can be splitted on IS of ISs, each containing IS of primes and only one composite ("statistical inversion", D.Lewis, 1986). Thus, fact that CNT occupies only tiny (tower exponentially small) fraction of Hilbert space, can be overridden by some nonergodic attractor implicating Aristotelean "final causation". Likewise, correlated radioactive decays imply possibility of strong (laser-like) departures from standard exponential decay law.

Berezin, Alexander A.

2003-03-01

197

Numbers in English and Chinese language use  

Microsoft Academic Search

The cultural connotations of numbers in English and Chinese languages are demonstrated to discuss the grammatical functions of the numbers and their rhetoric usages. For a foreign language learner, it is essential that they know not only the denotation of the numbers, but also the connotation of the numbers. Numbers frequently play an important role in daily communication.

ZHANG Wu-ping

2007-01-01

198

The Numbers Game: A Values Clarification Strategy  

ERIC Educational Resources Information Center

After completing personal identification forms consisting only of numbers (phone number, Social Security number, etc.), students discuss the need for more personal means of identification within society in order for people to feel a useful sense of identity. (AV)

Ognibene, Richard; Winter, Cynthia

1976-01-01

199

Links to Information on Number Systems  

NSDL National Science Digital Library

Site provides links to Web sites covering topics about different numbering systems. The site includes links to Arabic, Chinese, Mayan, Roman, Greek, Egyptian, and Babylonian numbering system resources.

Forum, Math; Alejandre, Suzanne

2007-12-12

200

Asymptotic statistical analysis of pseudo random numbers  

Microsoft Academic Search

edu Abstract-Computer simulation is a widely used powerful tool for solving real world problems. Pseudo random number plays an important role in computer simulation and modeling. It acts like the real random number. We discuss the asymptotic properties of pseudo random numbers as the period size of a random number generator approaches to infinity . Our results show that the

Alexandra L. Wang; Zhiguang Xu; Charles J. Kicey

2011-01-01

201

The Decimal Number System and Young Children  

ERIC Educational Resources Information Center

In this article, the author believes that a visual image of the number system is helpful to everyone, especially children, in understanding what is, after all, an abstract idea. The simplest model is the number line, a row of equally spaced numbers, starting at zero. This illustrates the continuous progression of the natural numbers, moving to the…

Harrison, John

2006-01-01

202

Visuospatial Priming of the Mental Number Line  

ERIC Educational Resources Information Center

It has been argued that numbers are spatially organized along a "mental number line" that facilitates left-hand responses to small numbers, and right-hand responses to large numbers. We hypothesized that whenever the representations of visual and numerical space are concurrently activated, interactions can occur between them, before response…

Stoianov, Ivilin; Kramer, Peter; Umilta, Carlo; Zorzi, Marco

2008-01-01

203

Fascinating Fibonaccis: Mystery and Magic in Numbers.  

ERIC Educational Resources Information Center

This document presents activities and information related to Fibonacci numbers, which are based upon the Golden Ratio, in areas of the arts, sciences, and mathematics. The work is organized into eight chapters: (1) "Origins and Definitions"; (2) "Fibonacci Numbers in Nature"; (3) "Fibonacci Numbers in Art and Architecture"; (4) "Fibonacci Numbers

Garland, Trudi Hammel

204

Contextual Effects on Number-Time Interaction  

ERIC Educational Resources Information Center

Time perception has long been known to be affected by numerical representations. Recent studies further demonstrate that when participants estimate the duration of Arabic numbers, number magnitude, though task-irrelevant, biases duration judgment to produce underestimation for smaller numbers and overestimation for larger numbers. Such effects…

Lu, Aitao; Hodges, Bert; Zhang, Jijia; Zhang, John X.

2009-01-01

205

Avogadro Number and Mole: A Royal Confusion.  

ERIC Educational Resources Information Center

There is a great deal of confusion in physics and chemistry textbooks, dictionaries, manuals, and handbooks about the definition of Avogadro's number and the term "mole." Avogadro's number is defined simply as the number of atomic mass units in one gram. Mole is defined as the mass of one Avogadro number of identical items. (Author/PR)

Emiliani, Cesare

1991-01-01

206

Number-operator approximation for pairing  

NASA Astrophysics Data System (ADS)

Conservation of particle number in the number-operator approximation of Otsuka and Arima is shown to require a particular normalization for the pair-creation operator. Even with this normalization, two difficulties arise: (a) the average number of particles in a shell can easily violate the Pauli principle, and (b) the mean square fluctuation of the particle number can be negative. As a consequence of the tendency to Pauli violation, the approximate ground-state expectation of the single-particle energy per particle is too low and fails to increase with the number of particles. NUCLEAR STRUCTURE Number conservation and Pauli principle in number-operator approximation for pairing.

Vincent, C. M.

1983-01-01

207

Additive number systems: Egyptian (Session 2)  

NSDL National Science Digital Library

In this session you will learn about the Egyptian number system. Learn About the Egyptian number system What do you notice about the Egyptian number system?Go here to learn In depth information about the Egyptian number system How does the number system represent the Egyptian culture? Additional questions: 1.What is the base? 2.Why was that base chosen? 3.How easy is the system to learn and to write? 4.Is there any ambiguity in ...

Nunes-Bufford, Mrs.

2008-12-01

208

46 CFR 169.541 - Number required.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Number required. 169.541 Section 169.541 Shipping COAST GUARD, DEPARTMENT OF HOMELAND...Firefighting Equipment Personal Flotation Devices § 169.541 Number required. Each vessel must be...

2013-10-01

209

46 CFR 169.515 - Number required.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Number required. 169.515 Section 169.515 Shipping COAST GUARD, DEPARTMENT OF HOMELAND...Firefighting Equipment Primary Lifesaving Equipment § 169.515 Number required. (a) Except as...

2013-10-01

210

Making Numbers in More Than One Way  

NSDL National Science Digital Library

In this lesson, students will find pairs of numbers that equal a number from 1-9. Students will represent these equalities with linking cubes, colored squares of construction paper, and written equations.

Brown, Kathleen

2012-07-20

211

Atomic and Molecular Calculations Using Quasirandom Numbers  

NASA Astrophysics Data System (ADS)

We have calculated the total ground-state energy, kinetic energy, and potential energy of He, H 2, Li, and Be using explicitly correlated wavefunctions and two numerical integration procedures. The first integration procedure uses pseudorandom numbers and converges as N-0.5. The second uses a set of quasirandom numbers generated by Halton's algorithm. Under some circumstances the convergence of this integration procedure can be as fast as N-1. When a small to intermediate number of quasirandom numbers are used, most of our expectation values converge faster than those computed using pseudorandom numbers. When a large number of quasirandom numbers are used, however, we find that most of the expectation values converge at roughly the same rate as those computed using pseudorandom numbers.

Alexander, S. A.; Coldwell, R. L.

2001-09-01

212

49 CFR 230.47 - Boiler number.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Boiler number. 230.47 Section 230.47...LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Steam Gauges § 230.47 Boiler number. (a) Generally. The...

2013-10-01

213

Efficient Parallel Pseudo-Random Number Generation.  

National Technical Information Service (NTIS)

A number of parallel randomized algorithms have appeared recently. These algorithms typically use a large number of random bits which must be generated in a small amount of time. Nonetheless, the area of parallel random bit generation remains unexplored. ...

J. H. Reif J. D. Tygar

1984-01-01

214

Poison control center - Emergency number (image)  

MedlinePLUS

... anywhere in the United States. This national hotline number will let you talk to experts in poisoning. ... control centers in the U.S. use this national number. You should call if you have any questions ...

215

Pearl Diver: A number line math game  

NSDL National Science Digital Library

In this Java application students must identify several points on a number line. The number line positions may include integers, fractional values, decimal values, and whole numbers. In the more advanced levels the number line does not begin with a 0 in all cases. Between levels students are asked to cut the eel into fractional parts and given points for their accuracy. This game is also available as an iOS app for a fee.

Lab, Nm S.

2013-01-01

216

Mechanisms of Chromosome Number Evolution in Yeast  

Microsoft Academic Search

The whole-genome duplication (WGD) that occurred during yeast evolution changed the basal number of chromosomes from 8 to 16. However, the number of chromosomes in post-WGD species now ranges between 10 and 16, and the number in non-WGD species (Zygosaccharomyces, Kluyveromyces, Lachancea, and Ashbya) ranges between 6 and 8. To study the mechanism by which chromosome number changes, we traced

Jonathan L. Gordon; Kevin P. Byrne; Kenneth H. Wolfe

2011-01-01

217

21 CFR 1210.21 - Permit number.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Permit number. 1210.21 Section 1210...FEDERAL IMPORT MILK ACT Permit Control § 1210.21 Permit number. Each permit issued under...permit, shall bear an individual number. The right to the use of...

2013-04-01

218

7 CFR 46.20 - Lot numbers.  

Code of Federal Regulations, 2010 CFR

... An identifying lot number shall be assigned to...sold on consignment or joint account or for the account...person or firm. A lot number should be assigned...while the consigned or joint account or disputed lot is being sold. A lot number shall be assigned...

2009-01-01

219

Number Pieces, by the Math Learning Center  

NSDL National Science Digital Library

This iOS app uses virtual base-10 blocks to help students develop their understanding of place value and computation strategies with multi-digit numbers. Students use the number pieces to represent multi-digit numbers, regroup, add, subtract, multiply, and divide.

2013-11-23

220

Insights into Our Understandings of Large Numbers  

ERIC Educational Resources Information Center

This article explores prospective teachers' understandings of one million to gain insights into the development of adult understanding of large numbers. Themes in the prospective teachers' work included number associated with a quantity of objects, number as an abstraction, and additive and multiplicative approaches. The authors suggest that the…

Kastberg, Signe E.; Walker, Vicki

2008-01-01

221

VESSEL REDUNDANCY: MODELING SAFETY IN NUMBERS  

Microsoft Academic Search

SUMMARY We examined the concept that high vessel number provides xylem safety and also show that under certain circumstances high vessel number may increase rather than decrease the probability of mortality. The independ- ent variable was the number of vessels per organ (redundancy). The de- pendent variable was the probability of organ death for which we set three thresholds for

Frank W. Ewers; John M. Ewers; Anna L. Jacobsen; Jorge López-Portillo

2007-01-01

222

Cycles and Universality in Sunspot Number Fluctuations  

NASA Astrophysics Data System (ADS)

We analyze the famous Wolf's sunspot numbers. Surprisingly, we discovered that the distribution of the sunspot number fluctuations for both the ascending and descending phases is close to the universal nonparametric Bramwell-Holdsworth-Pinton (BHP) distribution. Since the BHP probability density function appears in several other physical phenomena, our result reveals a universal feature of the Wolf's sunspot numbers.

Gonçalves, R.; Pinto, A. A.; Stollenwerk, N.

2009-02-01

223

Generalized Catalan Numbers and Generalized Hankel Transformations  

NASA Astrophysics Data System (ADS)

Cvetkovic, Rajkovic and Ivkovic proved that the Hankel transformation of the sequence of sums of adjacent Catalan numbers is a sequence of every other Fibonacci number. In this paper, an elementary proof is given and a generalization to sequences of generalized Catalan numbers.

Chamberland, Marc; French, Christopher

2007-01-01

224

46 CFR Sec. 7 - Job order numbering.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Job order numbering. Sec. 7 Section 7...REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 7 Job order numbering. (a) The NSA-LUMPSUMREP...Contract number shall be inserted in every job order and supplemental job order...

2013-10-01

225

Update on the national emergency number 911  

Microsoft Academic Search

The concept of a universal emergency number originated in Europe and in 1967 subsequently received federal government impetus for adoption in the United States. In 1968 the American Telephone and Telegraph Company agreed to clear the number 911 for any public safety agency and community groups that desired to develop a common public number for entry to local emergency services.

THOMAS I. DAYHARSH; TERRENCE J. YUNG; DWIGHT K. HUNTER; SUSAN C. IVY

1979-01-01

226

Teach Kids about Numbers All around Us  

ERIC Educational Resources Information Center

Recognizing the role numbers play in people's everyday lives is crucial to students' math understanding now and down the road. That's why Bob Krech, a curriculum specialist in New Jersey's West Windsor-Plainsboro district, likes to teach a lesson he calls "Numbers All Around Us." This lesson uses real-world examples to show that numbers help…

Hudson, Hannah Trierweiler

2011-01-01

227

Developing Young Children's Multidigit Number Sense.  

ERIC Educational Resources Information Center

This article describes a series of enrichment experiences designed to develop young (ages 5 to 8) gifted children's understanding of large numbers, central to their investigation of space travel. It describes activities designed to teach reading of large numbers and exploring numbers to a thousand and then a million. (Contains ten references.) (DB)

Diezmann, Carmel M.; English, Lyn D.

2001-01-01

228

Let's Count! Learning Numbers in Multiple Ways  

NSDL National Science Digital Library

In this 5-minute video Pre-K teacher Rosemary Kungu demonstrates a variety of activities that develop early number skills, including number recognition, counting and ordering numbers. The activities involve active participation and incorporate multiple senses and learning styles, music, and collaboration. A downloadable transcript of the video (doc) is included along with reflection questions for viewers.

2013-01-01

229

Integer valued polynomials over a number field  

Microsoft Academic Search

A number field is called a Pólya field if the module of integer valued polynomials over that field is generated by (fi)i=08 over the ring of integers, with deg(fi)=i, i=0, 1, 2,... In this paper bounds on the class numbers and on the number of ramified primes in Pólya fields are derived.

H. Zantema

1982-01-01

230

Calculating Mach Numbers Using Ratios and Fractions  

NSDL National Science Digital Library

A mach number represents how many times the speed of sound a vehicle is traveling. NASA uses mach numbers to describe the speed of their planes. This video shows you how algebra can be used to determine the mach number of a NASA plane.

2004-01-01

231

47 CFR 1.1405 - File numbers.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false File numbers. 1.1405 Section 1...PRACTICE AND PROCEDURE Grants by Random Selection Pole Attachment...Procedures § 1.1405 File numbers. Each complaint which...accepted and assigned a file number. Such assignment...

2013-10-01

232

The Decimal Representation of Real Numbers  

ERIC Educational Resources Information Center

The representation of natural numbers in decimal form is an unequivocal procedure while for the representation of real numbers some ambiguities concerning the existence of infinitely many digits equal to 9 still emerge. One of the most frequently confronted misunderstandings is whether 0.999...equals 1 or not, and if not what number does this…

Kalapodi, A.

2010-01-01

233

Maximum Sunspot Numbers and Active Days  

NASA Astrophysics Data System (ADS)

Parameters associated with solar minimum have been studied to relate them to solar activity at solar maximum so that one could possibly predict behaviors of an upcoming solar cycle. The number of active days has been known as a reliable indicator of solar activity around solar minimum. Active days are days with sunspots reported on the solar disk. In this work, we have explored the relationship between the sunspot numbers at solar maximum and the characteristics of the monthly number of active days. Specifically, we have statistically examined how the maximum monthly sunspot number of a given solar cycle is correlated with the slope of the linear relationship between monthly sunspot numbers and the monthly number of active days for the corresponding solar cycle. We have calculated the linear correlation coefficient r and the Spearman rank-order correlation coefficient rs for data sets prepared under various conditions. Even though marginal correlations are found, they turn out to be insufficiently significant (r ~ 0.3). Nonetheless, we have confirmed that the slope of the linear relationship between monthly sunspot numbers and the monthly number of active days is less steep when solar cycles belonging to the "Modern Maximum" are considered compared with rests of solar cycles. We conclude, therefore, that the slope of the linear relationship between monthly sunspot numbers and the monthly number of active days is indeed dependent on the solar activity at its maxima, but that this simple relationship should be insufficient as a valid method to predict the following solar activity amplitude.

Chang, Heon-Young

2013-09-01

234

On the binary expansions of algebraic numbers  

SciTech Connect

Employing concepts from additive number theory, together with results on binary evaluations and partial series, we establish bounds on the density of 1's in the binary expansions of real algebraic numbers. A central result is that if a real y has algebraic degree D > 1, then the number {number_sign}(|y|, N) of 1-bits in the expansion of |y| through bit position N satisfies {number_sign}(|y|, N) > CN{sup 1/D} for a positive number C (depending on y) and sufficiently large N. This in itself establishes the transcendency of a class of reals {summation}{sub n{ge}0} 1/2{sup f(n)} where the integer-valued function f grows sufficiently fast; say, faster than any fixed power of n. By these methods we re-establish the transcendency of the Kempner--Mahler number {summation}{sub n{ge}0}1/2{sup 2{sup n}}, yet we can also handle numbers with a substantially denser occurrence of 1's. Though the number z = {summation}{sub n{ge}0}1/2{sup n{sup 2}} has too high a 1's density for application of our central result, we are able to invoke some rather intricate number-theoretical analysis and extended computations to reveal aspects of the binary structure of z{sup 2}.

Bailey, David H.; Borwein, Jonathan M.; Crandall, Richard E.; Pomerance, Carl

2003-07-01

235

Minkowski Functionals Study of Random Number Sequences  

Microsoft Academic Search

Random number sequences are used in a wide range of applications such as simulation, sampling, numerical analysis, cryptography,\\u000a and recreation. The quality of random number sequences is critical to the correctness of these applications. Many statistical\\u000a tests have been developed to test various characteristics of random number generators such as randomness, independence, uniformity,\\u000a etc. Most of them are based on

Xinyu Zhang; Seth Watts; Yaohang Li; Daniel Tortorelli

2009-01-01

236

Quasi-Fibonacci Numbers of Order 11  

NASA Astrophysics Data System (ADS)

In this paper we introduce and investigate the so-called quasi-Fibonacci numbers of order 11 . These numbers are defined by five conjugate recurrence equations of order five. We study some relations and identities concerning these numbers. We present some applications to the decomposition of some polynomials. Many of the identities presented here are the generalizations of the identities characteristic for general recurrence sequences of order three given by Rabinowitz.

Witu?a, Roman; S?ota, Damian

2007-08-01

237

Bohr correspondence principle for large quantum numbers  

Microsoft Academic Search

Periodic systems are considered whose increments in quantum energy grow with quantum number. In the limit of large quantum number, systems are found to give correspondence in form between classical and quantum frequency-energy dependences. Solely passing to large quantum numbers, however, does not guarantee the classical spectrum. For the examples cited, successive quantum frequencies remain separated by the incrementhI\\u000a–1,

Richard L. Liboff

1975-01-01

238

High speed optical quantum random number generation.  

PubMed

We present a fully integrated, ready-for-use quantum random number generator (QRNG) whose stochastic model is based on the randomness of detecting single photons in attenuated light. We show that often annoying deadtime effects associated with photomultiplier tubes (PMT) can be utilized to avoid postprocessing for bias or correlations. The random numbers directly delivered to a PC, generated at a rate of up to 50 Mbit/s, clearly pass all tests relevant for (physical) random number generators. PMID:20588431

Fürst, Martin; Weier, Henning; Nauerth, Sebastian; Marangon, Davide G; Kurtsiefer, Christian; Weinfurter, Harald

2010-06-01

239

HotBits: Genuine Random Numbers  

NSDL National Science Digital Library

HotBits is a genuine random number generator powered by radioactive decay. Simply click the "Request HotBits" link, and specify how many bytes you would like (up to 2048) and in what form you prefer them. Hexadecimal returns numbers and letters, while C language returns integers. Then click the "Get HotBits" button, and your random numbers will appear on the screen.

Walker, John

2009-10-21

240

Factoring numbers with a single interferogram  

NASA Astrophysics Data System (ADS)

We construct an analog computer based on light interference to encode the hyperbolic function f(?)?1/? into a sequence of skewed curlicue functions. The resulting interferogram when scaled appropriately allows us to find the prime number decompositions of integers. We implement this idea exploiting polychromatic optical interference in a multipath interferometer and factor seven-digit numbers. We give an estimate for the largest number that can be factored by this scheme.

Tamma, Vincenzo; Zhang, Heyi; He, Xuehua; Garuccio, Augusto; Schleich, Wolfgang P.; Shih, Yanhua

2011-02-01

241

Using the Number Line to Compare  

NSDL National Science Digital Library

In this lesson, students determine differences using the number line to compare lengths. Because this model is based on linear measurement, it is a distinctly different representation from the models presented in the previous two lessons. At the end of this lesson, children are encouraged to predict differences and answer puzzles involving subtraction. Students will: use the number line model to find differences by comparing lengths solve and create puzzles using the number line

Illuminations

2012-03-31

242

On Generalized Fibonacci Polynomials and Bernoulli Numbers  

NASA Astrophysics Data System (ADS)

In this paper we use elementary methods to study the relationship between the generalized Fibonacci polynomials and the famous Bernoulli numbers, and give several interesting identities involving them.

Zhang, Tianping; Ma, Yuankui

2005-10-01

243

THE DISCOUNTED REPRODUCTIVE NUMBER FOR EPIDEMIOLOGY  

PubMed Central

The basic reproductive number, , and the effective reproductive number, , are commonly used in mathematical epidemiology as summary statistics for the size and controllability of epidemics. However, these commonly used reproductive numbers can be misleading when applied to predict pathogen evolution because they do not incorporate the impact of the timing of events in the life-history cycle of the pathogen. To study evolution problems where the host population size is changing, measures like the ultimate proliferation rate must be used. A third measure of reproductive success, which combines properties of both the basic reproductive number and the ultimate proliferation rate, is the discounted reproductive number . The discounted reproductive number is a measure of reproductive success that is an individual’s expected lifetime offspring production discounted by the background population growth rate. Here, we draw attention to the discounted reproductive number by providing an explicit definition and a systematic application framework. We describe how the discounted reproductive number overcomes the limitations of both the standard reproductive numbers and proliferation rates, and show that is closely connected to Fisher’s reproductive values for different life-history stages

Reluga, Timothy C.; Medlock, Jan; Galvani, Alison

2013-01-01

244

New Numbers in Mathematics in South Africa  

ERIC Educational Resources Information Center

This article is a follow-up of a study conducted in 2000 by the same authors on trends in numbers of mathematics majors at South African universities. Data from 12 universities for the 2000-2007 period is investigated. The previously observed trend of general and dramatic decrease in numbers of mathematics majors appears to have been reversed and…

Engelbrecht, Johann; Harding, Ansie

2009-01-01

245

When Symbolic Spatial Cues Go before Numbers  

ERIC Educational Resources Information Center

This work explores the effect of spatial cueing on number processing. Participants performed a parity judgment task. However, shortly before the target number, a cue (arrow pointing to left, arrow pointing to right or a cross) was centrally presented. In Experiment 1, in which responses were lateralized, the cue direction modulated the interaction…

Herrera, Amparo; Macizo, Pedro

2011-01-01

246

Analysis of the Linux Random Number Generator  

Microsoft Academic Search

Linux is the most popular open source project. The Linux random number generator is part of the kernel of all Linux distributions and is based on generating randomness from entropy of operating system events. The output of this generator is used for almost every security protocol, including TLS\\/SSL key generation, choosing TCP sequence numbers, and file system and email encryption.

Zvi Gutterman; Benny Pinkas; Tzachy Reinman

2006-01-01

247

47 CFR 32.20 - Numbering convention.  

Code of Federal Regulations, 2013 CFR

...following to the right of the decimal point indicate, respectively, the section or account. All Part 32 Account numbers contain 4 digits to-the-right-of the decimal point. (c) Cross references to accounts are made by citing the account numbers...

2013-10-01

248

18 CFR 367.4 - Numbering system.  

Code of Federal Regulations, 2013 CFR

...system. 367.4 Section 367.4 Conservation of Power and Water...General Instructions § 367.4 Numbering system. (a...consists of a system of three-digit whole numbers as follows: ...300-399, Property accounts. (4) 400-432 and 434-435,...

2013-04-01

249

Fostering Number Sense through Digits and Dice  

ERIC Educational Resources Information Center

Games are among the many types of activities that can be used to help promote number sense. Chosen and used wisely, games encourage learning and motivate many students to grasp concepts more quickly and fully. This article describes a popular and easy-to-implement number sense game--called Digits and Dice--most commonly used in conjunction with…

Wiest, Lynda R.

2006-01-01

250

A Generalization of the Prime Number Theorem  

ERIC Educational Resources Information Center

In this article, the author begins with the prime number theorem (PNT), and then develops this into a more general theorem, of which many well-known number theoretic results are special cases, including PNT. He arrives at an asymptotic relation that allows the replacement of certain discrete sums involving primes into corresponding differentiable…

Bruckman, Paul S.

2008-01-01

251

Atomic Fisher information versus atomic number  

NASA Astrophysics Data System (ADS)

It is shown that the Thomas Fermi Fisher information is negative. A slightly more sophisticated model proposed by Gáspár provides a qualitatively correct expression for the Fisher information: Gáspár's Fisher information is proportional to the two-third power of the atomic number. Accurate numerical calculations show an almost linear dependence on the atomic number.

Nagy, Á.; Sen, K. D.

2006-12-01

252

UNIFORM RANDOM NUMBER GENERATORS FOR SUPERCOMPUTERS  

Microsoft Academic Search

We consider the requirements for uniform pseudo-random number generators on modern vector and parallel supercomputers, consider the pros and cons of various classes of methods, and outline what is currently available. We propose a class of random number generators which have good statistical properties and can be implemented eciently on vector processors and parallel machines. A good method for initialization

RICHARD P. BRENT

1992-01-01

253

Reidentifying hardware after loss of serial number  

NASA Technical Reports Server (NTRS)

System traces fabrication and inspection records of special hardware back to the raw material. Reidentification of hardware, after loss of serial numbers, is established by X raying all parts again and comparing the new film with the original, whose numbers were previously recorded on serialized documents.

Wells, R. J.

1969-01-01

254

The Fibonacci Numbers and the Golden Section  

NSDL National Science Digital Library

This award-winning site explores not only who Fibonacci was, but also the Fibonacci number properties, where they occur in nature, and much, much more. Puzzles with answers, illustrations, diagrams, and graphs are included. The Golden Ratio and Lucas numbers are addressed here as well. This site contains over 200 pages of information.

Knott, Ron

2007-12-12

255

Infinite Sums of M-Bonacci Numbers  

ERIC Educational Resources Information Center

In this note, we construct infinite series using M-bonacci numbers in a manner similar to that used in previous studies and investigate the convergence of the series to an integer. Our results generalize the ones obtained for Fibonacci numbers.

A-iru, Muniru A.

2009-01-01

256

Our Numbers Are up! (Is That Good?)  

ERIC Educational Resources Information Center

There has been an increase on the number of applicants and the average SAT scores of the admitted students to colleges and universities in the United States. The total number of applicants may increase for purely external reasons, such as more students graduating from high school or more students reading good things about a particular college, but…

Speyer, Mark

2004-01-01

257

New string theories and their generation number  

NASA Astrophysics Data System (ADS)

New heterotic string theories in four dimensions are constructed by tensoring a nonstandard SCFT along with some minimal SCFTs. All such theories are identified and their particle generation number is found. We prove that from the infinite number of new heterotic string theories only the {6} theory predicts three generations as seen in nature which makes it an interesting candidate for further study.

Genish, Arel; Gepner, Doron

2014-08-01

258

THREE PARIETAL CIRCUITS FOR NUMBER PROCESSING  

Microsoft Academic Search

Did evolution endow the human brain with a predisposition to represent and acquire knowledge about numbers? Although the parietal lobe has been suggested as a potential substrate for a domain-specific representation of quantities, it is also engaged in verbal, spatial, and attentional functions that may contribute to calculation. To clarify the organisation of number-related processes in the parietal lobe, we

Stanislas Dehaene; Manuela Piazza; Philippe Pinel; Laurent Cohen

2002-01-01

259

Monitoring of Puffin numbers at Scottish colonies  

Microsoft Academic Search

Annual counting of occupied burrows in fixed areas of seven Puffin colonies in Scotland showed that the populations there were either stable or increasing. A drop of even 30% in the number of burrows between one year and the next could not be attributed to a disaster as the numbers increased greatly the next year.

M. P. Harris; S. Murray

1981-01-01

260

National Resources [and] National Toll Free Numbers.  

ERIC Educational Resources Information Center

This resource list provides names, addresses, and telephone numbers of 13 information clearinghouses and 42 organizations providing information on children and youth with disabilities. Telephone numbers are designated as either voice or text telephone. Spanish-language resources are also indicated. A list of organizations that have national…

National Information Center for Children and Youth with Disabilities, Washington, DC.

261

A New PseudoRandom Number Generator  

Microsoft Academic Search

Although the multiplicative congruential method for generating pseudo-random numbers is widely used and has passed a number of tests of randomness [1, 2], attempts have been made to find an additive congruential method since it could be expected to be faster. Tests on a Fibonacci sequence [1] have shown it to be unsatisfactory. The sequence xi+1 = (2a + 1)

A. Rotenberg

1960-01-01

262

Software Generation of Practically Strong Random Numbers  

Microsoft Academic Search

Although much thought usually goes into the design of encryption algorithms and protocols, less consideration is often given to equally important issues such as the selection of cryptographically strong random numbers, so that an attacker may find it easier to break the random number generator than the security system it is used with. This paper provides a comprehensive guide to

Peter Gutmann

1998-01-01

263

Predicting the required number of training samples  

NASA Technical Reports Server (NTRS)

A criterion which measures the quality of the estimate of the covariance matrix of a multivariate normal distribution is developed. Based on this criterion, the necessary number of training samples is predicted. Experimental results which are used as a guide for determining the number of training samples are included.

Kalayeh, H. M.; Landgrebe, D. A.

1982-01-01

264

Dividing Fraction by a Whole Number  

NSDL National Science Digital Library

Everything you need to know about Dividing Fractions by a Whole Number. Learn the steps for dividing fractions by whole numbers in How to do it. Start out slow and divide with Fractions fun with soccer. Speed up the fun with Fraction Hoops. ...

West, Mrs.

2013-01-04

265

Families of Linear Recurrences for Catalan Numbers  

ERIC Educational Resources Information Center

Four different families of linear recurrences are derived for Catalan numbers. The derivations rest on John Riordan's 1973 generalization of Catalan numbers to a set of polynomials. Elementary differential and integral calculus techniques are used and the results should be of interest to teachers and students of introductory courses in calculus…

Gauthier, N.

2011-01-01

266

Magnetic Particle Recovery of Serial Numbers  

Microsoft Academic Search

One method used by crime labs to recover obliterated serial numbers in steel firearms (ferrous samples) is the magnetic particle technique. The use of this method is predicated on the detection of metal deformation present under stamped serial numbers after the visible stamp has been removed. Equipment specialized for this detection is not used in these attempts; a portable magnetic

Dave Utrata; Marcus J. Johnson

2003-01-01

267

On the Concept Image of Complex Numbers  

ERIC Educational Resources Information Center

A study of how Swedish students understand the concept of complex numbers was performed. A questionnaire was issued reflecting the student view of own perception. Obtained answers show a variety of concept images describing how students adopt the concept of complex numbers. These concept images are classified into four categories in order to…

Nordlander, Maria Cortas; Nordlander, Edvard

2012-01-01

268

Compendium of Experimental Cetane Number Data  

SciTech Connect

In this report, we present a compilation of reported cetane numbers for pure chemical compounds. The compiled database contains cetane values for 299 pure compounds, including 156 hydrocarbons and 143 oxygenates. Cetane number is a relative ranking of fuels based on the amount of time between fuel injection and ignition. The cetane number is typically measured either in a combustion bomb or in a single-cylinder research engine. This report includes cetane values from several different measurement techniques - each of which has associated uncertainties. Additionally, many of the reported values are determined by measuring blending cetane numbers, which introduces significant error. In many cases, the measurement technique is not reported nor is there any discussion about the purity of the compounds. Nonetheless, the data in this report represent the best pure compound cetane number values available from the literature as of August 2004.

Murphy, M. J.; Taylor, J. D.; McCormick, R. L.

2004-09-01

269

STP Ideal Gas Number Of States Program  

NSDL National Science Digital Library

The STP IdealGasNumberOfStates program numerically evaluates the number of states of an ideal gas and demonstrates finite size effects by plotting the actual number of states and the asymptotic expression. The default is two-dimensional system (d=2). STP IdealGasNumberOfStates is part of a suite of Open Source Physics programs that model aspects of Statistical and Thermal Physics (STP). The program is distributed as a ready-to-run (compiled) Java archive. Double clicking the stp_IdealGasNumberOfStates.jar file will run the program if Java is installed on your computer. Additional programs can be found by searching ComPADRE for Open Source Physics, STP, or Statistical and Thermal Physics.

Gould, Harvey; Tobochnik, Jan; Christian, Wolfgang; Cox, Anne

2009-02-17

270

Relativistic theory of surficial Love numbers  

NASA Astrophysics Data System (ADS)

A relativistic theory of surficial Love numbers, which characterize the surface deformation of a body subjected to tidal forces, was initiated by Damour and Nagar. We revisit this effort in order to extend it, clarify some of its aspects, and simplify its computational implementation. First, we refine the definition of surficial Love numbers proposed by Damour and Nagar and formulate it directly in terms of the deformed curvature of the body's surface, a meaningful geometrical quantity. Second, we develop a unified theory of surficial Love numbers that applies equally well to material bodies and black holes. Third, we derive a compactness-dependent relation between the surficial and (electric-type) gravitational Love numbers of a perfect-fluid body and show that it reduces to the familiar Newtonian relation when the compactness is small. And fourth, we simplify the tasks associated with the practical computation of the surficial and gravitational Love numbers for a material body.

Landry, Philippe; Poisson, Eric

2014-06-01

271

LEAN: laser-etched aqua number  

NASA Astrophysics Data System (ADS)

A security device on a banknote has to be recognized immediately by the general public and has to enable the general public to establish the genuineness of the banknote. This is the so-called first line of defense. Recently the development of the ability to establish the genuiness has gained momentum and is called 'self authenticating.' Comparing the banknote number with a 'watermark number' can do authenticating. The watermark number is engraved by a laser beam in the paper and is -- as the printed number -- different for each note. Recent progress in the material processing by laser enables the engraving of the individual watermark number for each banknote in line with the production process.

Schell, Karel J.

1998-04-01

272

Low Reynolds number airfoil survey, volume 1  

NASA Technical Reports Server (NTRS)

The differences in flow behavior two dimensional airfoils in the critical chordlength Reynolds number compared with lower and higher Reynolds number are discussed. The large laminar separation bubble is discussed in view of its important influence on critical Reynolds number airfoil behavior. The shortcomings of application of theoretical boundary layer computations which are successful at higher Reynolds numbers to the critical regime are discussed. The large variation in experimental aerodynamic characteristic measurement due to small changes in ambient turbulence, vibration, and sound level is illustrated. The difficulties in obtaining accurate detailed measurements in free flight and dramatic performance improvements at critical Reynolds number, achieved with various types of boundary layer tripping devices are discussed.

Carmichael, B. H.

1981-01-01

273

Ramsey Numbers and Adiabatic Quantum Computing  

NASA Astrophysics Data System (ADS)

The graph-theoretic Ramsey numbers are notoriously difficult to calculate. In fact, for the two-color Ramsey numbers R(m,n) with m, n?3, only nine are currently known. We present a quantum algorithm for the computation of the Ramsey numbers R(m,n). We show how the computation of R(m,n) can be mapped to a combinatorial optimization problem whose solution can be found using adiabatic quantum evolution. We numerically simulate this adiabatic quantum algorithm and show that it correctly determines the Ramsey numbers R(3,3) and R(2,s) for 5?s?7. We then discuss the algorithm’s experimental implementation, and close by showing that Ramsey number computation belongs to the quantum complexity class quantum Merlin Arthur.

Gaitan, Frank; Clark, Lane

2012-01-01

274

Random walks on the mental number line.  

PubMed

The direction of influence between conceptual and motor activation, and its relevance for real-life activities, is still unclear. Here, we use the frequently reported association between small/large numbers and left/right space to investigate this issue during walking. We asked healthy adults to generate random numbers as they made lateral turns and found that (1) lateral turn decisions are predicted by the last few numbers generated prior to turning; (2) the intention to turn left/right makes small/large numbers more accessible; and (3) magnitude but not order of auditorily presented numbers influences the listener's turn selection. Our findings document a bidirectional influence between conceptual and motor activation and point to a hierarchically organized conceptual-motor activation. PMID:24091774

Shaki, Samuel; Fischer, Martin H

2014-01-01

275

Topological numbering of features on a mesh  

NASA Technical Reports Server (NTRS)

Assume a nxn binary image is given containing horizontally convex features; i.e., for each feature, each of its row's pixels form an interval on that row. The problem of assigning topological numbers to such features is considered; i.e., assign a number to every feature f so that all features to the left of f have a smaller number assigned to them. This problem arises in solutions to the stereo matching problem. A parallel algorithm to solve the topological numbering problem in O(n) time on an nxn mesh of processors is presented. The key idea of the solution is to create a tree from which the topological numbers can be obtained even though the tree does not uniquely represent the to the left of relationship of the features.

Atallah, Mikhail J.; Hambrusch, Susanne E.; Tewinkel, Lynn E.

1988-01-01

276

Mental Number Line, Number Line Estimation, and Mathematical Achievement: Their Interrelations in Grades 5 and 6  

Microsoft Academic Search

As indicated by the distance effect and the spatial–numerical association of response codes (SNARC) effect, natural numbers are mentally represented on a number line. Purportedly, this number line underlies children’s number sense, which supports the acquisition of more advanced mathematical competencies. In 3 studies with a total of 429 fifth and sixth graders, the authors compared the influences of each

Michael Schneider; Roland H. Grabner; Jennifer Paetsch

2009-01-01

277

Performance Analysis of the Interval Algorithm for Random Number Generation Based on Number Systems  

Microsoft Academic Search

In this paper we analyze the interval algorithm for random number generation proposed by Han and Hoshi using the expression of real numbers on the interval . We first establish an explicit representation of the interval algorithm with the repre- sentation of real numbers on the interval based on number systems. Next, using the expression of the interval algorithm, we

Yasutada Oohama

2011-01-01

278

48 CFR 52.204-6 - Data Universal Numbering System Number.  

Code of Federal Regulations, 2013 CFR

...annotation âDUNSâ or âDUNS+4â followed by the DUNS number or âDUNS+4â that identifies the offeror's...offer. The DUNS number is a nine-digit number assigned by Dun and Bradstreet, Inc. The DUNS+4 is the DUNS number plus a...

2013-10-01

279

The Numbers 1 to 5 in the Development of Children's Number Concepts.  

ERIC Educational Resources Information Center

Proposes the hypothesis that preschoolers have number concepts based on the numbers 1-5 rather than on the decimal structure. Results suggest that children understand numbers to 5 as a privileged anchor. Proposes a new model for a representational system of numbers. (Author/DR)

Yoshida, Hajime; Kuriyama, Kazuhiro

1986-01-01

280

Random numbers spring from alpha decay  

SciTech Connect

Congruential random number generators, which are widely used in Monte Carlo simulations, are deficient in that the number they generate are concentrated in a relatively small number of hyperplanes. While this deficiency may not be a limitation in small Monte Carlo studies involving a few variables, it introduces a significant bias in large simulations requiring high resolution. This bias was recognized and assessed during preparations for an accident analysis study of nuclear power plants. This report describes a random number device based on the radioactive decay of alpha particles from a /sup 235/U source in a high-resolution gas proportional counter. The signals were fed to a 4096-channel analyzer and for each channel the frequency of signals registered in a 20,000-microsecond interval was recorded. The parity bits of these frequency counts (0 for an even count and 1 for an odd count) were then assembled in sequence to form 31-bit binary random numbers and transcribed to a magnetic tape. This cycle was repeated as many times as were necessary to create 3 million random numbers. The frequency distribution of counts from the present device conforms to the Brockwell-Moyal distribution, which takes into account the dead time of the counter (both the dead time and decay constant of the underlying Poisson process were estimated). Analysis of the count data and tests of randomness on a sample set of the 31-bit binary numbers indicate that this random number device is a highly reliable source of truly random numbers. Its use is, therefore, recommended in Monte Carlo simulations for which the congruential pseudorandom number generators are found to be inadequate. 6 figures, 5 tables.

Frigerio, N.A.; Sanathanan, L.P.; Morley, M.; Clark, N.A.; Tyler, S.A.

1980-05-01

281

Exploring number space by random digit generation.  

PubMed

There is some evidence that human subjects preferentially select small numbers when asked to sample numbers from large intervals "at random". A retrospective analysis of single digit frequencies in 16 independent experiments with the Mental Dice Task (generation of digits 1-6 during 1 min) confirmed the occurrence of small-number biases (SNBs) in 488 healthy subjects. A subset of these experiments suggested a spatial nature of this bias in the sense of a "leftward" shift along the number line. First, individual SNBs were correlated with leftward deviations in a number line bisection task (but unrelated to the bisection of physical lines). Second, in 20 men, the magnitude of SNBs significantly correlated with leftward attentional biases in the judgment of chimeric faces. Finally, cognitive activation of the right hemisphere enhanced SNBs in 20 different men, while left hemisphere activation reduced them. Together, these findings provide support for a spatial component in random number generation. Specifically, they allow an interpretation of SNBs in terms of "pseudoneglect in number space." We recommend the use of random digit generation for future explorations of spatial-attentional asymmetries in numerical processing and discuss methodological issues relevant to prospective designs. PMID:17294177

Loetscher, Tobias; Brugger, Peter

2007-07-01

282

Estimating shorebird numbers at migration stopover sites  

USGS Publications Warehouse

We describe a method for estimating the total number of shorebirds that use a migration stopover site during spring and fall migration. We combined weekly shorebird counts with parameter estimates for detection probability, sampled proportion, and length of stay on the Squaw Creek National Wildlife Refuge. Double sampling was used to determine detection probability and estimated values varied among wetland units from a low of 0.07 to a high of 0.82. The sampled proportion of most wetland units was 100% but was lower in some of the larger units. Length of stay (measured for Pectoral [Calidris melanotos] and Least Sandpipers [C. minutilla] combined) averaged 10.0 days in spring and 3.7 days in fall. Spring shorebird numbers were approximately five times greater than fall numbers on the Refuge. Annual shorebird numbers varied among years from an estimated low in 2003 of 15 734 to a high in 2002 of 69 570. Peak daily counts during study years averaged only 12% of estimated spring totals and 4% of fall totals. An estimate of shorebird numbers based on summing weekly counts, not corrected for detection probability or sampled proportion, would have been only 21% (spring) to 31% (fall) of the total number of birds. These results reveal that peak counts and nonadjusted counts can significantly underestimate the number of shorebirds that use migration stopover sites in the midcontinent of North America. ?? The Cooper Ornithological Society 2006.

Farmer, A.; Durbian, F.

2006-01-01

283

Number generation bias after action observation.  

PubMed

Recent studies have demonstrated that conceptual and abstract knowledge could rely on and could be influenced by sensory-motor processing of usual goal-directed actions. In line with this, interactions have been reported between number magnitude and finger grip with, for example, small-magnitude numbers priming grip closure and large-magnitude numbers priming grip aperture. Here, we assessed whether observing a closing or opening grip was able to influence the magnitude of the numbers produced in a random number generation task, and we tested whether this effect was specific to biological hand actions by using non-biological fake hands with the same closure or aperture amplitude. The participants were asked to produce as randomly as possible numbers between 1 and 10 after they observed a change in posture (i.e. grip closing or grip opening) or in colour (i.e. red or blue hand). The results revealed that the participants produced more often small numbers than large ones after observing a grip closing, whereas they produced equally often small and large numbers after observing a grip opening or colour changes. Importantly, this effect was only present for the biological hands but not for the non-biological fake hands. This finding demonstrates that observing a biological grip closing conveys small-magnitude information, which, in turn, influences the mental selection of a numerical response. We discuss our results in the light of the internal random generator process proposed in the domain of numerical cognition and argue that number semantics is stored with a code governed by sensory-motor mechanisms. PMID:22744775

Badets, Arnaud; Bouquet, Cédric A; Ric, François; Pesenti, Mauro

2012-08-01

284

Number of spin I states for bosons  

SciTech Connect

We study number of spin I states for bosons in this article. We extend Talmi's recursion formulas for number of states with given spin I to boson systems, and we prove empirical formulas for five bosons by using these recursions. We obtain number of states with given spin I and F spin for three and four bosons by using sum rules of six-j and nine-j symbols. We also present empirical formulas of states for d bosons with given spin I and F=F{sub max}-1 and F{sub max}-2.0.

Zhang, L. H.; Zhao, Y. M.; Jia, L. Y.; Arima, A. [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000 (China); AST, World Laboratory, P. O. Box 8730, Beijing 100080 (China); Department of Electric Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Science Museum, Japan Science Foundation, 2-1 Kitanomaru-koen, Chiyoda-ku, Tokyo 102-0091 (Japan)

2008-01-15

285

The generative basis of natural number concepts.  

PubMed

Number concepts must support arithmetic inference. Using this principle, it can be argued that the integer concept of exactly ONE is a necessary part of the psychological foundations of number, as is the notion of the exact equality - that is, perfect substitutability. The inability to support reasoning involving exact equality is a shortcoming in current theories about the development of numerical reasoning. A simple innate basis for the natural number concepts can be proposed that embodies the arithmetic principle, supports exact equality and also enables computational compatibility with real- or rational-valued mental magnitudes. PMID:18468942

Leslie, Alan M; Gelman, Rochel; Gallistel, C R

2008-06-01

286

An Introduction to the Theory of Numbers  

NSDL National Science Digital Library

Written by Leo Moser and presented by the Trillia Group, this virtual text introduces visitors to the theory of numbers. After agreeing to the terms and conditions of use, users will be able to download the full document as an 87-page pdf file in either large or regular print. The chapters include: "Compositions and Partitions," "Irrational Numbers," "Diophantine Equations," and "Geometry of Numbers." The terms limit this free download to students in mathematic self-study or for instructors to consider this text for use in their classrooms.

Moser, Leo

2007-12-03

287

Standard random number generation for MBASIC  

NASA Technical Reports Server (NTRS)

A machine-independent algorithm is presented and analyzed for generating pseudorandom numbers suitable for the standard MBASIC system. The algorithm used is the polynomial congruential or linear recurrence modulo 2 method. Numbers, formed as nonoverlapping adjacent 28-bit words taken from the bit stream produced by the formula a sub m + 532 = a sub m + 37 + a sub m (modulo 2), do not repeat within the projected age of the solar system, show no ensemble correlation, exhibit uniform distribution of adjacent numbers up to 19 dimensions, and do not deviate from random runs-up and runs-down behavior.

Tausworthe, R. C.

1976-01-01

288

Multiplication: An Adventure in Number Sense  

NSDL National Science Digital Library

This activity helps students learn their multiplication tables, but also build their reasoning about numbers, their relationships and their patterns in the multiplication table. The tutorial begins with a multiplication applet and leads the student through a number of different strategies for stream lining the number of multiplication facts from 100 down to thirteen. Each page in the unit consists of dialogs between a student and a mentor, as well as illustrations, summaries and suggestions for further explorations and activities. Users can skip dialogs if they wish, going directly for the summaries and activities.

2005-01-01

289

Critical points and number of master integrals  

NASA Astrophysics Data System (ADS)

We consider the question about the number of master integrals for a multiloop Feynman diagram. We show that, for a given set of denominators, this number is totally determined by the critical points of the polynomials entering either of the two representations: the parametric representation and the Baikov representation. In particular, for the parametric representation the corresponding polynomial is just the sum of Symanzik polynomials. The relevant topological invariant is the sum of the Milnor numbers of the proper critical points. We present a Mathematica package Mint to automatize the counting of the master integrals for the typical case, when all critical points are isolated.

Lee, Roman N.; Pomeransky, Andrei A.

2013-11-01

290

The roles of cell size and cell number in determining ovariole number in Drosophila.  

PubMed

All insect ovaries are composed of functional units called ovarioles, which contain sequentially developing egg chambers. The number of ovarioles varies between and within species. Ovariole number is an important determinant of fecundity and thus affects individual fitness. Although Drosophila oogenesis has been intensively studied, the genetic and cellular basis for determination of ovariole number remains unknown. Ovariole formation begins during larval development with the morphogenesis of terminal filament cells (TFCs) into stacks called terminal filaments (TFs). We induced changes in ovariole number in Drosophila melanogaster by genetically altering cell size and cell number in the TFC population, and analyzed TF morphogenesis in these ovaries to understand the cellular basis for the changes in ovariole number. Increasing TFC size contributed to higher ovariole number by increasing TF number. Similarly, increasing total TFC number led to higher ovariole number via an increase in TF number. By analyzing ovarian morphogenesis in another Drosophila species we showed that TFC number regulation is a target of evolutionary change that affects ovariole number. In contrast, temperature-dependent plasticity in ovariole number was due to changes in cell-cell sorting during TF morphogenesis, rather than changes in cell size or cell number. We have thus identified two distinct developmental processes that regulate ovariole number: establishment of total TFC number, and TFC sorting during TF morphogenesis. Our data suggest that the genetic changes underlying species-specific ovariole number may alter the total number of TFCs available to contribute to TF formation. This work provides for the first time specific and quantitative developmental tools to investigate the evolution of a highly conserved reproductive structure. PMID:22200592

Sarikaya, Didem Pelin; Belay, Abel A; Ahuja, Abha; Dorta, Aisha; Green, Delbert André; Extavour, Cassandra G

2012-03-01

291

Generation of Random Numbers by Micromechanism  

NASA Astrophysics Data System (ADS)

We have successfully developed a novel micromechanism of random number generator (RNG) by using the silicon micromachining technique. The MEM(Micro Electro Mechanical)RNG produce a series of random numbers by using the pull-in instability of electrostatic actuation operated with a typical dc 150 volt. The MEM RNG is made by the deep reactive ion etching of a silicon-on-insulator(SOI) wafer, and is very small compared with the conventional RNG hardware based on the randomness of thermal noise or isotope radiation. Quality of randomness has been experimentally confirmed by the self-correlation study of the generated series of numbers. The MEM RNG proposed here would be a true random number generation, which is needed for the highly secured encryption system of today’s information technology.

Mita, Makoto; Toshiyoshi, Hiroshi; Ataka, Manabu; Fujita, Hiroyuki

292

An Application of Number Theory to Cryptology.  

ERIC Educational Resources Information Center

Discussed is an application of number theory to cryptology that can be used with secondary school students. Background on the topics is given first, followed by an explanation for use of the topic. (MNS)

Snow, Joanne R.

1989-01-01

293

Bone Mass Measurement: What the Numbers Mean  

MedlinePLUS

... Bone Basics Bone Mass Measurement: What the Numbers Mean Publication available in: PDF (168 KB) Español Chinese ( ... Health and Osteoporosis Surgeon General's Report: What It Means to You Informe del Año 2004 del Cirujano ...

294

Reynold Number Scaling at Transonic Speeds.  

National Technical Information Service (NTIS)

This paper focuses on Reynolds number scaling (RNS) at transonic speeds for military aircraft development. RNS has been used in the development of aircraft for decades because most development wind tunnels have not had the capability of providing full sca...

M. L. Laster E. Stanewsky D. W. Sinclair W. L. Sickles

1998-01-01

295

New technique for number-plate recognition  

NASA Astrophysics Data System (ADS)

This paper presents an alternative algorithm for number plate recognition. The algorithm consists of three modules. Respectively, they are number plate location module, character segmentation module and character recognition module. Number plate location module extracts the number plate from the detected car image by analyzing the color and the texture properties. Different from most license plate location methods, the algorithm has fewer limits to the car size, the car position in the image and the image background. Character segmentation module applies connected region algorithm both to eliminate noise points and to segment characters. Touching characters and broken characters can be processed correctly. Character recognition module recognizes characters with HHIC (Hierarchical Hybrid Integrated Classifier). The system has been tested with 100 images obtained from crossroad and parking lot, etc, where the cars have different size, position, background and illumination. Successful recognition rate is about 92%. The average processing time is 1.2 second.

Guo, Jie; Shi, Peng-Fei

2001-09-01

296

Axisymmetric Annulus Convection at Unit Prandtl Number.  

National Technical Information Service (NTIS)

The document covers the role played in annulus flows by mechanisms dependent upon the Prandtl number, sigma. Solutions are obtained at sigma = 1 for both the real annulus system and for the hypothetical free annulus system (free slip lateral boundaries). ...

G. P. Williams

1969-01-01

297

Thermal convection at infinite Prandtl number  

NASA Technical Reports Server (NTRS)

Numerical solutions are developed for the full scaled three dimensional thermal convection problem, at infinite Prandtl number, and for rigid boundaries. The procedure is designed to give an approximate account of horizontally homogeneous and isotropic flow situations. Results, which included a maximum of 36 horizontal wave number vectors and 20 vertical wave numbers, appear to adequately describe the flow fill up to R = 100,000; beyond this R the results appear to show horizontal wave number truncation error. This error seems to affect the boundary slope of the mean temperature field more than other mean quantities. Despite some numerical uncertainities, certain of the qualitative features of the flow fill are predicted with reasonable confidence.

Herring, J. R.

1969-01-01

298

Ideal photon number amplifier and duplicator  

NASA Technical Reports Server (NTRS)

The photon number-amplification and number-duplication mechanism are analyzed in the ideal case. The search for unitary evolutions leads to consider also a number-deamplification mechanism, the symmetry between amplification and deamplification being broken by the integer-value nature of the number operator. Both transformations, amplification and duplication, need an auxiliary field which, in the case of amplification, turns out to be amplified in the inverse way. Input-output energy conservation is accounted for using a classical pump or through frequency-conversion of the fields. Ignoring one of the fields is equivalent to considering the amplifier as an open system involving entropy production. The Hamiltonians of the ideal devices are given and compared with those of realistic systems.

Dariano, G. M.

1992-01-01

299

Axial Compressor Airfoils for Supersonic Mach Numbers.  

National Technical Information Service (NTIS)

The report concerns axial compressor airfoils suitable for operation at supersonic Mach numbers. Two, relatively versatile camber-line shapes and a common thickness distribution are mathematically derived. One camber line is particularly appropriate for b...

A. J. Wennerstrom R. M. Hearsey

1970-01-01

300

Chaotic behaviour of high Mach number flows  

NASA Technical Reports Server (NTRS)

The stability of the super-Alfvenic flow of a two-fluid plasma model with respect to the Mach number and the angle between the flow direction and the magnetic field is investigated. It is found that, in general, a large scale chaotic region develops around the initial equilibrium of the laminar flow when the Mach number exceeds a certain threshold value. After reaching a maximum the size of this region begins shrinking and goes to zero as the Mach number tends to infinity. As a result high Mach number flows in time independent astrophysical plasmas may lead to the formation of 'quasi-shocks' in the presence of little or no dissipation.

Varvoglis, H.; Ghosh, S.

1985-01-01

301

Using Random Numbers in Science Research Activities.  

ERIC Educational Resources Information Center

Discusses the importance of science process skills and describes ways to select sets of random numbers for selection of subjects for a research study in an unbiased manner. Presents an activity appropriate for grades 5-12. (JRH)

Schlenker, Richard M.; And Others

1996-01-01

302

Microcomputer-Assisted Discoveries: Random Numbers.  

ERIC Educational Resources Information Center

A programing contest was designed to promote interest in mathematical randomness. Student-developed programs making clever uses of random numbers are presented. Modifications users might make are suggested. (MNS)

Kimberling, Clark

1983-01-01

303

Generation of pseudo-random numbers  

NASA Technical Reports Server (NTRS)

Practical methods for generating acceptable random numbers from a variety of probability distributions which are frequently encountered in engineering applications are described. The speed, accuracy, and guarantee of statistical randomness of the various methods are discussed.

Howell, L. W.; Rheinfurth, M. H.

1982-01-01

304

Baryon Number Violation and Particle Collider Experiments.  

National Technical Information Service (NTIS)

Baryon number nonconservation, due to nonperturbative effects (sphalerons) in the standard model, may have been important in the early Universe. The possibility that similar effects could show up at future particle collider experiments is discussed. These...

F. R. Klinkhamer

1992-01-01

305

Small Atwood number Rayleigh-Taylor experiments.  

PubMed

Consideration is given to small Atwood number (non-dimensional density difference) experiments to investigate mixing driven by Rayleigh-Taylor (R-T) instability. The past 20 years have seen the development of novel experiments to investigate R-T mixing and, simultaneously, the advent of high-fidelity diagnostics. Indeed, the developments of experiments and diagnostics have gone hand in hand, and as a result modern R-T experiments rival the capabilities and research scope of shear-driven mixing experiments. Thus, research into the small Atwood number limit has made significant progress over the past 20 years, and has offered important insights into natural mixing processes as well as the general R-T problem. This review of small Atwood number experiments serves as an opportunity to discuss progress, and also to provoke thoughts about future high Atwood number designs and difficulties. PMID:20211879

Andrews, Malcolm J; Dalziel, Stuart B

2010-04-13

306

An optimality criterion for the crossing number  

Microsoft Academic Search

A sufficient condition is given that a certain drawing minimizes the cross- ing number. The condition is in terms of intersections in an arbitrary set system related to the drawing, and is like a correlation inequality.

Laszlo A. Szekely

307

Infiltration formulas by curve number procedure.  

USGS Publications Warehouse

The Soil Conservation Service (SCS) curve number procedure for estimating runoff volume is examined in terms of the validity and applicability of the derived infiltration equations. -from ASCE Publications Abstracts

Chen, C. -L.

1982-01-01

308

Error Correction in Redundant Residue Number Systems  

Microsoft Academic Search

Two error-correcting algorithms for redundant residue number systems are presented, one for single residue-error correction and the other for burst residue-error correction. Neither algorithm requires table lookup, and hence their implementation needs a memory space which is much smaller than that required by existing methods. Furthermore, the conditions which the moduli of the redundant residue number systems must satisfy for

S. S.-S. Yau; Yu-Cheng Liu

1973-01-01

309

Scheme for a quantum random number generator  

NASA Astrophysics Data System (ADS)

A scheme for a random number generator based on the intrinsic randomness of quantum mechanics is proposed. A Fresnel multiple prism which can act as a perfect 50/50 beam splitter is used to realize the random events by choosing single photons from a polarized laser beam. A procedure to get rid of the bias of the raw sequences is discussed in detail together with the random number generation efficiency per light pulse.

Wang, P. X.; Long, G. L.; Li, Y. S.

2006-09-01

310

Sequential Real Number Computation and Recursive Relations  

Microsoft Academic Search

In the first author's thesis [Marcial-Romero, J. R., “Semantics of a sequential language for exact real-number computation”, PhD thesis at the University of Birmingham, 2004)], a sequential language, LRT, for real number computation is investigated. The thesis includes a proof that all polynomials are programmable, but that work comes short of giving a complete characterization of the expressive power of

J. Raymundo Marcial-romero; M. Andrew Moshier

2008-01-01

311

Mingle & Count: A Game of Number Sense  

NSDL National Science Digital Library

In this 5-minute video Barbara McCormick demonstrates an activity that helps her kindergarten students develop number sense. Students mingle and, on the teacher's signal, form themselves into groups of a given number. This active experience with equal groups helps build the foundation for multiplication and division with remainders. A sidebar provides reflection questions for viewers. A downloadable transcript (doc) of the video is included.

2012-01-01

312

Acoustic mixing at low Reynold's numbers  

NASA Astrophysics Data System (ADS)

In microfluidic devices, hydrodynamic flow is usually governed by very low Reynold's numbers. Under these conditions, only laminar flow is possible. Hence, mixing in microfluidics occurs by diffusion only. Interaction of small fluid volumes and acoustic waves in a solid leads to pronounced streaming effects in the fluid inducing mixing and stirring even at low Reynold's numbers. We demonstrate the applicability of such acoustically induced mixing in a variety of different microfluidic geometries, including planar and conventional three-dimensional microfluidic devices.

Sritharan, K.; Strobl, C. J.; Schneider, M. F.; Wixforth, A.; Guttenberg, Z.

2006-01-01

313

4.NBT Ordering 4-digit numbers  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Arrange these numbers in increasing order, beginning with the least. 2400 \\ 4002 \\ 2040 \\ 420 \\ 2004 Arrange these numbers in decreasing order, beginni...

314

Harmonic graphs with small number of cycles  

Microsoft Academic Search

Let G be a graph on n vertices v1,v2,…,vn and let d(vi) be the degree (= number of first neighbors) of the vertex vi. If (d(v1),d(v2),…,d(vn))t is an eigenvector of the (0,1)-adjacency matrix of G, then G is said to be harmonic. Earlier all harmonic trees were determined; their number is infinite. We now show that for any c,c>1, the

Bojana Borovicanin; Stefan Grünewald; Ivan Gutman; Miroslav Petrovic

2003-01-01

315

Determining the acid number of biodiesel  

Microsoft Academic Search

Commerical biodiesel is composed of FAME. It may also contain small amounts of FA, which are quantified by an acid number,\\u000a expressed as milligrams of potassium hydroxide required to neutralize 1 g of sample. In 2006, the ASTM D 6751 biodiesel acid-number\\u000a limit was harmonized with the European biodiesel value of 0.50. ASTM D 664 is the standard reference method

Sonam Mahajan; Samir K. Konar; David G. b. Boocock

2006-01-01

316

On optimal condition numbers for Markov chains  

Microsoft Academic Search

Let T and $${\\\\tilde{T}=T-E}$$ be arbitrary nonnegative, irreducible, stochastic matrices corresponding to two ergodic Markov chains on n states. A function ? is called a condition number for Markov chains with respect to the (?, ?)–norm pair if $${\\\\|\\\\pi-\\\\tilde{\\\\pi}\\\\|_\\\\alpha \\\\leq \\\\kappa(T)\\\\|E\\\\|_\\\\beta}$$. Here ? and $${\\\\tilde \\\\pi}$$ are the stationary distribution vectors of the two chains, respectively. Various condition numbers, particularly

Stephen J. Kirkland; Michael Neumann; Nung-Sing Sze

2008-01-01

317

I'm Thinking of a Number  

NSDL National Science Digital Library

This game for the interactive white board (free access with registration) provides an opportunity for players to practice finding the number in a word problem using the function chosen ( double it, halve it, 1 more/1 less and 10 more/10 less). The numbers are also shown as amounts in marbles to help children to visualize the calculation. There are options to change the difficulty level and the operation.

2012-07-13

318

Persistent consequences of atypical early number concepts.  

PubMed

How does symbolic number knowledge performance help identify young children at risk for poor mathematics achievement outcomes? In research and practice, classification of mathematics learning disability (MLD, or dyscalculia) is typically based on composite scores from broad measures of mathematics achievement. These scores do predict later math achievement levels, but do not specify the nature of math difficulties likely to emerge among students at greatest risk for long-term mathematics failure. Here we report that gaps in 2nd and 3rd graders' number knowledge predict specific types of errors made on math assessments at Grade 8. Specifically, we show that early whole number misconceptions predict slower and less accurate performance, and atypical computational errors, on Grade 8 arithmetic tests. We demonstrate that basic number misconceptions can be detected by idiosyncratic responses to number knowledge items, and that when such misconceptions are evident during primary school they persist throughout the school age years, with variable manifestation throughout development. We conclude that including specific qualitative assessments of symbolic number knowledge in primary school may provide greater specificity of the types of difficulties likely to emerge among students at risk for poor mathematics outcomes. PMID:24027540

Mazzocco, Michèle M M; Murphy, Melissa M; Brown, Ethan C; Rinne, Luke; Herold, Katherine H

2013-01-01

319

Persistent consequences of atypical early number concepts  

PubMed Central

How does symbolic number knowledge performance help identify young children at risk for poor mathematics achievement outcomes? In research and practice, classification of mathematics learning disability (MLD, or dyscalculia) is typically based on composite scores from broad measures of mathematics achievement. These scores do predict later math achievement levels, but do not specify the nature of math difficulties likely to emerge among students at greatest risk for long-term mathematics failure. Here we report that gaps in 2nd and 3rd graders' number knowledge predict specific types of errors made on math assessments at Grade 8. Specifically, we show that early whole number misconceptions predict slower and less accurate performance, and atypical computational errors, on Grade 8 arithmetic tests. We demonstrate that basic number misconceptions can be detected by idiosyncratic responses to number knowledge items, and that when such misconceptions are evident during primary school they persist throughout the school age years, with variable manifestation throughout development. We conclude that including specific qualitative assessments of symbolic number knowledge in primary school may provide greater specificity of the types of difficulties likely to emerge among students at risk for poor mathematics outcomes.

Mazzocco, Michele M. M.; Murphy, Melissa M.; Brown, Ethan C.; Rinne, Luke; Herold, Katherine H.

2013-01-01

320

Ion stopping powers and CT numbers.  

PubMed

One of the advantages of ion beam therapy is the steep dose gradient produced near the ion's range. Use of this advantage makes knowledge of the stopping powers for all materials through which the beam passes critical. Most treatment planning systems calculate dose distributions using depth dose data measured in water and an algorithm that converts the kilovoltage X-ray computed tomography (CT) number of a given material to its linear stopping power relative to water. Some materials present in kilovoltage scans of patients and simulation phantoms do not lie on the standard tissue conversion curve. The relative linear stopping powers (RLSPs) of 21 different tissue substitutes and positioning, registration, immobilization, and beamline materials were measured in beams of protons accelerated to energies of 155, 200, and 250 MeV; carbon ions accelerated to 290 MeV/n; and iron ions accelerated to 970 MeV/n. These same materials were scanned with both kilovoltage and megavoltage CT scanners to obtain their CT numbers. Measured RLSPs and CT numbers were compared with calculated and/or literature values. Relationships of RLSPs to physical densities, electronic densities, kilovoltage CT numbers, megavoltage CT numbers, and water equivalence values converted by a treatment planning system are given. Usage of CT numbers and substitution of measured values into treatment plans to provide accurate patient and phantom simulations are discussed. PMID:19931030

Moyers, Michael F; Sardesai, Milind; Sun, Sean; Miller, Daniel W

2010-01-01

321

Number skills are maintained in healthy ageing.  

PubMed

Numerical skills have been extensively studied in terms of their development and pathological decline, but whether they change in healthy ageing is not well known. Longer exposure to numbers and quantity-related problems may progressively refine numerical skills, similar to what happens to other cognitive abilities like verbal memory. Alternatively, number skills may be sensitive to ageing, reflecting either a decline of number processing itself or of more auxiliary cognitive abilities that are involved in number tasks. To distinguish between these possibilities we tested 30 older and 30 younger participants on an established numerosity discrimination task requiring to judge which of two sets of items is more numerous, and on arithmetical tasks. Older participants were remarkably accurate in performing arithmetical tasks although their numerosity discrimination (also known as 'number acuity') was impaired. Further analyses indicate that this impairment was limited to numerosity trials requiring inhibiting information incongruent to numerosity (e.g., fewer but larger items), and that this also correlated with poor inhibitory processes measured by standard tests. Therefore, rather than a numerical impairment, poor numerosity discrimination is likely to reflect elderly's impoverished inhibitory processes. This conclusion is supported by simulations with a recent neuro-computational model of numerosity perception, where only the specific degradation of inhibitory processes produced a pattern that closely resembled older participants' performance. Numeracy seems therefore resilient to ageing but it is influenced by the decline of inhibitory processes supporting number performance, consistent with the 'Inhibitory Deficit' Theory. PMID:24423632

Cappelletti, Marinella; Didino, Daniele; Stoianov, Ivilin; Zorzi, Marco

2014-03-01

322

A feeling for the numbers in biology  

PubMed Central

Although the quantitative description of biological systems has been going on for centuries, recent advances in the measurement of phenomena ranging from metabolism to gene expression to signal transduction have resulted in a new emphasis on biological numeracy. This article describes the confluence of two different approaches to biological numbers. First, an impressive array of quantitative measurements make it possible to develop intuition about biological numbers ranging from how many gigatons of atmospheric carbon are fixed every year in the process of photosynthesis to the number of membrane transporters needed to provide sugars to rapidly dividing Escherichia coli cells. As a result of the vast array of such quantitative data, the BioNumbers web site has recently been developed as a repository for biology by the numbers. Second, a complementary and powerful tradition of numerical estimates familiar from the physical sciences and canonized in the so-called “Fermi problems” calls for efforts to estimate key biological quantities on the basis of a few foundational facts and simple ideas from physics and chemistry. In this article, we describe these two approaches and illustrate their synergism in several particularly appealing case studies. These case studies reveal the impact that an emphasis on numbers can have on important biological questions.

Phillips, Rob; Milo, Ron

2009-01-01

323

Ion Stopping Powers and CT Numbers  

SciTech Connect

One of the advantages of ion beam therapy is the steep dose gradient produced near the ion's range. Use of this advantage makes knowledge of the stopping powers for all materials through which the beam passes critical. Most treatment planning systems calculate dose distributions using depth dose data measured in water and an algorithm that converts the kilovoltage X-ray computed tomography (CT) number of a given material to its linear stopping power relative to water. Some materials present in kilovoltage scans of patients and simulation phantoms do not lie on the standard tissue conversion curve. The relative linear stopping powers (RLSPs) of 21 different tissue substitutes and positioning, registration, immobilization, and beamline materials were measured in beams of protons accelerated to energies of 155, 200, and 250 MeV; carbon ions accelerated to 290 MeV/n; and iron ions accelerated to 970 MeV/n. These same materials were scanned with both kilovoltage and megavoltage CT scanners to obtain their CT numbers. Measured RLSPs and CT numbers were compared with calculated and/or literature values. Relationships of RLSPs to physical densities, electronic densities, kilovoltage CT numbers, megavoltage CT numbers, and water equivalence values converted by a treatment planning system are given. Usage of CT numbers and substitution of measured values into treatment plans to provide accurate patient and phantom simulations are discussed.

Moyers, Michael F., E-mail: MFMoyers@roadrunner.co [Department of Proton Therapy, Inc., Colton, CA (United States); Sardesai, Milind [Department of Long Beach Memorial Medical Center, Long Beach, CA (United States); Sun, Sean [Department of City of Hope National Medical Center, Duarte, CA (United States); Miller, Daniel W. [Department of Loma Linda University Medical Center, Loma Linda, CA (United States)

2010-10-01

324

Mechanisms of Chromosome Number Evolution in Yeast  

PubMed Central

The whole-genome duplication (WGD) that occurred during yeast evolution changed the basal number of chromosomes from 8 to 16. However, the number of chromosomes in post-WGD species now ranges between 10 and 16, and the number in non-WGD species (Zygosaccharomyces, Kluyveromyces, Lachancea, and Ashbya) ranges between 6 and 8. To study the mechanism by which chromosome number changes, we traced the ancestry of centromeres and telomeres in each species. We observe only two mechanisms by which the number of chromosomes has decreased, as indicated by the loss of a centromere. The most frequent mechanism, seen 8 times, is telomere-to-telomere fusion between two chromosomes with the concomitant death of one centromere. The other mechanism, seen once, involves the breakage of a chromosome at its centromere, followed by the fusion of the two arms to the telomeres of two other chromosomes. The only mechanism by which chromosome number has increased in these species is WGD. Translocations and inversions have cycled telomere locations, internalizing some previously telomeric genes and creating novel telomeric locations. Comparison of centromere structures shows that the length of the CDEII region is variable between species but uniform within species. We trace the complete rearrangement history of the Lachancea kluyveri genome since its common ancestor with Saccharomyces and propose that its exceptionally low level of rearrangement is a consequence of the loss of the non-homologous end joining (NHEJ) DNA repair pathway in this species.

Gordon, Jonathan L.; Byrne, Kevin P.; Wolfe, Kenneth H.

2011-01-01

325

Transference number calculations for sodium polysulfides  

SciTech Connect

Transference numbers of sodium cations and sulfur anions in sodium polysulfide melts are calculated from previously determined experimental data. Concentrated electrolyte theory assuming a binary electrolyte consisting of sodium anions, sulfide cations, in a neutral sulfur solvent is used to relate the transference numbers to fundamental solution transport properties. Slopes of open-circuit potential measurements vs. melt composition on sodium-sulfur cells with and without transference are used to determine the sulfur anion and sodium cation transference numbers. The transference number of sodium cations is calculated from previous experimental data for two temperatures, 573 and 633 K, and range from 0.88 to 0.93 for sodium sulfide mole fractions between 0.20 and 0.34. These values for transference numbers presented here are more accurate than previous interpretations of these data where unity sodium cation transference numbers were assumed. The results of this work are shown to be important in the design of sodium-sulfur cells.

Risch, T.; Newman, J.

1988-07-01

326

78 FR 36725 - Numbering Policies for Modern Communications; IP-Enabled Services; Telephone Number Requirements...  

Federal Register 2010, 2011, 2012, 2013

...interconnected VoIP providers to obtain phone numbers directly from the number administrators...will hinder or prevent call routing or tracking, and how such complications can be prevented...telecommunications services, such as satellite tracking, communications telemetry, and...

2013-06-19

327

Of Colored Numbers and Numbered Colors: Interactive Processes in Grapheme-Color Synesthesia  

Microsoft Academic Search

Grapheme-color synesthetes experience a specific color when they see a grapheme but they do not report to perceive a grapheme when a color is presented. In this study, we investigate whether color can still evoke number-processes even when a vivid number experience is absent. We used color-number and number-color priming, both revealing faster responses in congruent compared to incongruent conditions.

Titia Gebuis; Tanja C. W. Nijboer; Maarten J. van der Smagt

2009-01-01

328

An Exploratory Study of a Number Sense Program to Develop Kindergarten Students' Number Proficiency  

ERIC Educational Resources Information Center

This study examined the effectiveness of a number sense program on kindergarten students' number proficiency and responsiveness to treatment as a function of students' risk for mathematics difficulties. The program targeted development of relationships among numbers (e.g., spatial, more and less). A total of 101 kindergarten students (not at risk:…

Sood, Sheetal; Jitendra, Asha K.

2013-01-01

329

Beyond the Mental Number Line: A Neural Network Model of Number-Space Interactions  

ERIC Educational Resources Information Center

It is commonly assumed that there is an interaction between the representations of number and space (e.g., [Dehaene et al., 1993] and [Walsh, 2003]), typically ascribed to a mental number line. The exact nature of this interaction has remained elusive, however. Here we propose that spatial aspects are not inherent to number representations, but…

Chen, Qi; Verguts, Tom

2010-01-01

330

The Numbers Game: Phasing in Generated ID Numbers at the University of Oregon  

ERIC Educational Resources Information Center

With all the recent headlines about security breaches and information loss at financial and educational institutions, the higher education community needs to address the issue of using social security numbers as ID numbers. The University of Oregon undertook a change process to assign generated ID numbers to all records in their information…

Eveland, Sue

2005-01-01

331

MOIRCS Deep Survey. I: DRG Number Counts  

NASA Astrophysics Data System (ADS)

We used very deep near-infrared imaging data taken with the Multi-Object InfraRed Camera and Spectrograph (MOIRCS) on the Subaru Telescope to investigate the number counts of Distant Red Galaxies (DRGs). We observed a 4' × 7' field in the Great Observatories Origins Deep Survey-North (GOODS-N), and our data reached J=24.6 and K=23.2 (5?, Vega magnitude). The surface density of DRGs selected by J - K > 2.3 is 2.35 ± 0.31 arcmin-2 at K < 22 and 3.54 ± 0.38 arcmin-2 at K < 23, respectively. These values are consistent with those in the GOODS-South and FIRES. Our deep and wide data suggest that the number counts of DRGs turn over at K ˜ 22, and the surface density of the faint DRGs with K > 22 is smaller than that expected from the number counts at the brighter magnitude. The result indicates that while there are many bright galaxies at 2 < z < 4 with the relatively old stellar population and/or heavy dust extinction, the number of faint galaxies with a similar red color is relatively small. Different behavior patterns of the number counts of the DRGs and bluer galaxies with 2 < zphot < 4 at K > 22 suggest that the mass-dependent color distribution, where most of the low-mass galaxies are blue, while more massive galaxies tend to have redder colors, had already been established at that epoch.

Kajisawa, Masaru; Konishi, Masahiro; Suzuki, Ryuji; Tokoku, Chihiro; Uchimoto, Yuka; Katsuno; Yoshikawa, Tomohiro; Akiyama, Masayuki; Ichikawa, Takashi; Ouchi, Masami; Omata, Koji; Tanaka, Ichi; Nishimura, Tetsuo; Yamada, Toru

2006-12-01

332

Nonlinear dynamos at infinite magnetic Prandtl number.  

PubMed

The dynamo instability is investigated in the limit of infinite magnetic Prandtl number. In this limit the fluid is assumed to be very viscous so that the inertial terms can be neglected and the flow is enslaved to the forcing. The forcing consist of an external forcing function that drives the dynamo flow and the resulting Lorentz force caused by the back reaction of the magnetic field. The flows under investigation are the Archontis flow and the ABC flow forced at two different scales. The investigation covers roughly 3 orders of magnitude of the magnetic Reynolds number above onset. All flows show a weak increase of the averaged magnetic energy as the magnetic Reynolds number is increased. Most of the magnetic energy is concentrated in flat elongated structures that produce a Lorentz force with small solenoidal projection so that the resulting magnetic field configuration is almost force free. Although the examined system has zero kinetic Reynolds number at sufficiently large magnetic Reynolds number the structures are unstable to small scale fluctuations that result in a chaotic temporal behavior. PMID:21517581

Alexakis, Alexandros

2011-03-01

333

High Reynolds Number Thermal Stability Experiments  

NASA Technical Reports Server (NTRS)

This work represents preliminary thermal stability results for liquid hydrocarbon fuels. High Reynolds Number Thermal Stability experiments with Jet A and RP-1 resulted in a quantitative measurement of the thermal stability. Each fuel flowed through a heated capillary tube that held the outlet temperature at 290 C. An optical pyrometer measured the surface temperature of the tube at 12 locations as a function of time. The High Reynolds Number Thermal Stability number was then determined using standards published by the American Society for Testing and Materials. The results for Jet A showed lower thermal stability than similar tests conducted at another facility. The RP-1 results are the first reported using this technique. Because the temperature rise on the capillary tube during testing for the RP-1 fuels was not significant, a new standard for the testing conditions should be developed for these types of fuels.

Emens, Jessica M.; Brown, Sarah P.; Frederick Robert A., Jr.; Wood, A. John

2004-01-01

334

Electron heating in superhigh Mach number shocks  

NASA Technical Reports Server (NTRS)

Fluid and MHD models, as well as direct extrapolation of the earth's bow shock measurements in the high Mach number (HMN) range to the superhigh Mach number (SHMN) range predict that the downstream electron pressure is only a negligible fraction of the Rankine-Hugoniot downstream pressure. Following Alfven, plasma physics experimental-theoretical data combined with magnetospheric observations were used to probe the physics of the SHMN shocks. It is shown that inclusion of proper plasma physics considerations in the interaction of the reflected and transmitted ions and the electrons at the 'foot' of the shock leads to the surprising result that electron heating can dominate in the SHNM range. A stationary model of the shock structure is derived and shown to be the result of extrapolation of the high Mach number shock physics wiht incorporation of collective interactions at the foot.

Papadopoulos, K.

1988-01-01

335

PHD filtering with localised target number variance  

NASA Astrophysics Data System (ADS)

Mahler's Probability Hypothesis Density (PHD filter), proposed in 2000, addresses the challenges of the multipletarget detection and tracking problem by propagating a mean density of the targets in any region of the state space. However, when retrieving some local evidence on the target presence becomes a critical component of a larger process - e.g. for sensor management purposes - the local target number is insufficient unless some confidence on the estimation of the number of targets can be provided as well. In this paper, we propose a first implementation of a PHD filter that also includes an estimation of localised variance in the target number following each update step; we then illustrate the advantage of the PHD filter + variance on simulated data from a multiple-target scenario.

Delande, Emmanuel; Houssineau, Jérémie; Clark, Daniel

2013-05-01

336

Congruent numbers with many prime factors  

PubMed Central

Mohammed Ben Alhocain, in an Arab manuscript of the 10th century, stated that the principal object of the theory of rational right triangles is to find a square that when increased or diminished by a certain number, m becomes a square [Dickson LE (1971) History of the Theory of Numbers (Chelsea, New York), Vol 2, Chap 16]. In modern language, this object is to find a rational point of infinite order on the elliptic curve . Heegner constructed such rational points in the case that m are primes congruent to 5,7 modulo 8 or twice primes congruent to 3 modulo 8 [Monsky P (1990) Math Z 204:45–68]. We extend Heegner's result to integers m with many prime divisors and give a sketch in this report. The full details of all the proofs will be given in ref. 1 [Tian Y (2012) Congruent Numbers and Heegner Points, arXiv:1210.8231].

Tian, Ye

2012-01-01

337

A new methodology for detecting source number  

NASA Astrophysics Data System (ADS)

Current methods for detecting source number in magnetic source image (MSI) have some shortcomings: i) they are somewhat subjective, ii) various MSIs employ different indexes, and iii) the number of the potential sources in MSI via Beamforming may be underestimated. The new approach extracts a principal component from each trial which serves as a (one) representative virtual channel for that trial. Principal components from all trials are combined to form a (one) synthesized trial. The information criterion is applied to this synthesized trial to select an optimal estimate of the source number. PCA reduces noise and captures the greatest variability in each trial, the synthesized trial reduces data fluctuations among trials and also reduces the dimensions of the covariance matrix. The approach is entirely data-driven and is suitable for detecting seizures and interictal spikes in epilepsy patients.

Lei, Tianhu; Roberts, Timothy P. L.

2011-03-01

338

Linear Congruent Random Number Generator Model  

NSDL National Science Digital Library

The Linear Congruent Random Number Generator Model generates a sequence of integers x[i] over the interval [0, m-1] by the recurrence relation x[i+1] = (a*x[i]+c) mod m where the modulus m is greater than zero, the multiplier a is greater than zero and less than m, and the increment c is greater than zero and less than m. All numbers are integers and all arithmetic is integer arithmetic. The initial value x[0] is known as the seed. The Linear Congruent Number Generator 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_math_RandomLCG.jar file will run the program if Java is installed.

Christian, Wolfgang

2009-05-09

339

Two-bit quantum random number generator based on photon-number-resolving detection  

NASA Astrophysics Data System (ADS)

Here we present a new fast two-bit quantum random number generator based on the intrinsic randomness of the quantum physical phenomenon of photon statistics of coherent light source. Two-bit random numbers were generated according to the number of detected photons in each light pulse by a photon-number-resolving detector. Poissonian photon statistics of the coherent light source guaranteed the complete randomness of the bit sequences. Multi-bit true random numbers were generated for the first time based on the multi-photon events from a coherent light source.

Jian, Yi; Ren, Min; Wu, E.; Wu, Guang; Zeng, Heping

2011-07-01

340

Probing lepton number violation on three frontiers  

NASA Astrophysics Data System (ADS)

Neutrinoless double beta decay constitutes the main probe for lepton number violation at low energies, motivated by the expected Majorana nature of the light but massive neutrinos. On the other hand, the theoretical interpretation of the (non-)observation of this process is not straightforward as the Majorana neutrinos can destructively interfere in their contribution and many other New Physics mechanisms can additionally mediate the process. We here highlight the potential of combining neutrinoless double beta decay with searches for Tritium decay, cosmological observations and LHC physics to improve the quantitative insight into the neutrino properties and to unravel potential sources of lepton number violation.

Deppisch, Frank F.

2013-12-01

341

Increasing the Numbers, A Partial Success Story  

NASA Astrophysics Data System (ADS)

Compared to all other sciences, physics has the lowest representation of women, with only engineering having proportionally fewer women. According to NSF, only 201 African-Americans earned physics Ph.D. degrees between 1973 and 1996, less than 1% of the total number of physics Ph.D. degrees granted during that time period. The picture is similar for other under represented groups. AIP has a number of outreach programs that serve to focus attention on the above issue. This talk will describe some of these programs and chronicle efforts to work with the physics community to attract and retain members of underrepresented groups in physics.

Stith, James H.

2000-04-01

342

6.NS Fractions on the Number Line  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Find and label the numbers $\\frac43$, $\\frac 54$, $-\\frac23$, and $-\\frac34$ on the number line. For each of the following, state which inequality is t...

343

Gene copy number and malaria biology  

PubMed Central

Alteration in gene copy number provides a simple way to change expression levels and alter phenotype. This was fully appreciated by bacteriologists more than 25 years ago, but the extent and implications of copy number polymorphism (CNP) have only recently become apparent in other organisms. New methods demonstrate the ubiquity of CNPs in eukaryotes and their medical importance in humans. CNP is also widespread in the Plasmodium falciparum genome and has an important and underappreciated role in determining phenotype. In this review, we summarize the distribution of CNP, its evolutionary dynamics within populations, its functional importance and its mode of evolution.

Anderson, Tim J.C.; Patel, Jigar; Ferdig, Michael T.

2010-01-01

344

Statistical Analysis of Random Number Generators  

NASA Astrophysics Data System (ADS)

In many applications, for example cryptography and Monte Carlo simulation, there is need for random numbers. Any procedure, algorithm or device which is intended to produce such is called a random number generator (RNG). What makes a good RNG? This paper gives an overview on empirical testing of the statistical properties of the sequences produced by RNGs and special software packages designed for that purpose. We also present the results of applying a particular test suite--TestU01-- to a family of RNGs currently being developed at the Centro Interdipartimentale Vito Volterra (CIVV), Roma, Italy.

Accardi, Luigi; Gäbler, Markus

2011-01-01

345

All numbers are not equal: an electrophysiological investigation of small and large number representations.  

PubMed

Behavioral and brain imaging research indicates that human infants, humans adults, and many nonhuman animals represent large nonsymbolic numbers approximately, discriminating between sets with a ratio limit on accuracy. Some behavioral evidence, especially with human infants, suggests that these representations differ from representations of small numbers of objects. To investigate neural signatures of this distinction, event-related potentials were recorded as adult humans passively viewed the sequential presentation of dot arrays in an adaptation paradigm. In two studies, subjects viewed successive arrays of a single number of dots interspersed with test arrays presenting the same or a different number; numerical range (small numerical quantities 1-3 vs. large numerical quantities 8-24) and ratio difference varied across blocks as continuous variables were controlled. An early-evoked component (N1), observed over widespread posterior scalp locations, was modulated by absolute number with small, but not large, number arrays. In contrast, a later component (P2p), observed over the same scalp locations, was modulated by the ratio difference between arrays for large, but not small, numbers. Despite many years of experience with symbolic systems that apply equally to all numbers, adults spontaneously process small and large numbers differently. They appear to treat small-number arrays as individual objects to be tracked through space and time, and large-number arrays as cardinal values to be compared and manipulated. PMID:18752403

Hyde, Daniel C; Spelke, Elizabeth S

2009-06-01

346

Number Word Use in Toddlerhood Is Associated with Number Recall Performance at Seven Years of Age  

PubMed Central

Previous studies have shown that verbal working memory and vocabulary acquisition are linked in early childhood. However, it is unclear whether acquisition of a narrow range of words during toddlerhood may be particularly related to recall of the same words later in life. Here we asked whether vocabulary acquisition of number words, location and quantifier terms over the first three years of life are associated with verbal and visuospatial working memory at seven years. Our results demonstrate that children who produced more number words between 20–26 months and started to produce the number words 1–10 earlier showed greater number recall at 7 years of age. This link was specific to numbers and neither extended to quantifier and location terms nor verbal and visuospatial working memory performance with other stimuli. These findings suggest a category-specific link between the mental lexicon of number words and working memory for numbers at an early age.

Libertus, Melissa E.; Marschik, Peter B.; Einspieler, Christa

2014-01-01

347

Limitation enhancement of a mixed convection by a vibrational heat surface in a vertical channel  

NASA Astrophysics Data System (ADS)

A numerical simulation is performed to study effects of a vibrational heat surface on a mixed convection in a vertical channel flow. This subject is a kind of moving boundary problems, and the finite element method and arbitrary Lagrangian Eulerian kinematics description method is then utilized. The main parameters of Grashof number, amplitude and frequency are taken into consideration, and the Reynolds number is limited and equals 100. According to the results, the equations of the critical vibration frequency could be derived and expressed in terms of Grashof number and amplitude. In the forced convection, the critical vibration frequency is only dependent on the amplitude, and in the mixed convection the critical vibration frequency becomes larger as the Grashof number increases. The variation of the critical vibration frequency of the study could league with the critical vibration frequency of the natural convection shown in the previous study consistently.

Fu, Wu-Shung; Huang, Chien-Ping

2008-04-01

348

47 CFR 52.111 - Toll free number assignment.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 2013-10-01 false Toll free number assignment. 52.111 Section 52.111...CARRIER SERVICES (CONTINUED) NUMBERING Toll Free Numbers § 52.111 Toll free number assignment. Toll free numbers...

2013-10-01

349

Reduction in the number of coupling parameters  

Microsoft Academic Search

A method is developed for reducing the formulation of massless models with several independent couplings to a description in terms of a single coupling parameter. The original as well as the reduced system are supposed to be renormalizable and invariant under the renormalization group. For most models there are, if any, only a finite number of reductions possible including those

W. Zimmermann

1985-01-01

350

Supercomputers lower the cost of number crunching  

SciTech Connect

A new breed of computer handles jobs too large for ordinary mainframes. Not just scaled-up versions of standard computers, these fast number crunchers use highly compact circuits and new ways of handling data to gain high-speed operation and large memory capacities.

Krouse, J.K.

1983-01-06

351

COPY NUMBER CONTROL OF TN~ TRANSPOSITION  

Microsoft Academic Search

Transposition of Tn5 in Escherichia coli strains containing one or multiple copies of the transposable element was investigated. It was found that the overall frequency of transposition within a cell remained constant regardless of the number of copies of Tn5 present in that cell. Experiments measuring the transposition frequency of differentially marked Tn5s confirmed that the fre- quency of transposition

REID C. JOHNSON; WILLIAM S. REZNIKOFF

1984-01-01

352

Germline copy number variation in control populations  

Microsoft Academic Search

Copy number variation (CNV) is an important source of genomic variation. Characterizing CNVs in phenotypically normal individuals is important for understanding the functional significance of these variants. Many studies have reported CNVs in control populations, but wide variability is observed in their design and outcome. Importantly, medical and phenotypic information for control populations must be carefully documented, and accurate genotyping

W. Al-Sukhni; S. Gallinger

2008-01-01

353

Uniform random number generators: a review  

Microsoft Academic Search

ABSTRACT This paper summarizes the current state - of - the - art on uniform random number generation for stochas - tic simulation It recalls the basic ideas, discusses some linear methods and their theoretical analysis, and provides pointers to further details and to rec - ommended implementations

Pierre L'Ecuyer

1997-01-01

354

On Statistical Testing of Random Numbers Generators  

Microsoft Academic Search

Maurer's test is nowadays a basic statistical tool for testing physical random number gen- erators in cryptographic applications. Based on a statistical analysis of this test we propose simple and efiective methods for its improvement. These methods are related to the m - spacing technique common in goodness-of-flt problems and the L - leave out method used for a noise

Fida El Haje; Yuri Golubev; Pierre-yvan Liardet; Yannick Teglia

2006-01-01

355

Monte Carlo simulation and random number generation  

Microsoft Academic Search

Methods of generating pseudorandom number sequences that might have predetermined spectral and probability distribution functions are discussed. Such sequences are of potential value in Monte Carlo simulation of communication, radar, and allied systems. The methods described are particularly suited to implementation on microcomputers, are machine portable, and have been subjected to exhaustive investigation by means of both statistical and theoretical

RODNEY F. W. COATES; GARETH J. JANACEK; KENNETH V. LEVER

1988-01-01

356

Uniform Random Number Generators: A Review  

Microsoft Academic Search

This paper summarizes the current state-of-the-art on uniform random number generation for stochastic simulation. It recalls the basic ideas, discusses some linear methods and their theoretical analysis, and provides pointers to further details and to recommended implementations.

Pierre L'Ecuyer

1997-01-01

357

EMPIRICAL SPECTRAL ANALYSIS OF RANDOM NUMBER GENERATORS  

Microsoft Academic Search

Computer simulation procedures have become a staple of research and development in many fields, including statistics. The generation of random number sequences is critical to these procedures. The validity of research results often depend on the underlying validity of the generator being used. In this work we develop the theory for the Empirical Spectral Test (EST). The EST is a

DAVID ZEITLER; SIEMENS DEMATIC; JOSEPH MCKEAN; JOHN KAPENGA

2001-01-01

358

Chinese Number Words, Culture, and Mathematics Learning  

ERIC Educational Resources Information Center

This review evaluates the role of language--specifically, the Chinese-based system of number words and the simplicity of Chinese mathematical terms--in explaining the relatively superior performance of Chinese and other East Asian students in cross-national studies of mathematics achievement. Relevant research is critically reviewed focusing on…

Ng, Sharon Sui Ngan; Rao, Nirmala

2010-01-01

359

Inferring relative numbers of human leucocyte genome  

Microsoft Academic Search

Summary Genome duplication inevitably results in replication errors. A priori, the more times a genome is copied, the greater the average number of replication errors. This principle could be used to 'count' mitotic divisions. Although somatic mutations are rare, cytosine methylation is also copied after DNA replication, but measurably increases with aging at certain CpG rich sequences in mitotic tissues,

Michelle Chu; Kimberly D. Siegmund

360

Golden Proportions for the Generalized Tribonacci Numbers  

ERIC Educational Resources Information Center

It is known that the ratios of consecutive terms of Fibonacci and Tribonacci sequences converge to the fixed ratio. In this article, we consider the generalized form of Tribonacci numbers and derive the "golden proportion" for the whole family of this generalized sequence. (Contains 2 tables.)

Shah, Devbhadra V.; Mehta, Darshana A.

2009-01-01

361

Preferential solvation: dividing surface vs excess numbers.  

PubMed

How do osmolytes affect the conformation and configuration of supramolecular assembly, such as ion channel opening and actin polymerization? The key to the answer lies in the excess solvation numbers of water and osmolyte molecules; these numbers are determinable solely from experimental data, as guaranteed by the phase rule, as we show through the exact solution theory of Kirkwood and Buff (KB). The osmotic stress technique (OST), in contrast, purposes to yield alternative hydration numbers through the use of the dividing surface borrowed from the adsorption theory. However, we show (i) OST is equivalent, when it becomes exact, to the crowding effect in which the osmolyte exclusion dominates over hydration; (ii) crowding is not the universal driving force of the osmolyte effect (e.g., actin polymerization); (iii) the dividing surface for solvation is useful only for crowding, unlike in the adsorption theory which necessitates its use due to the phase rule. KB thus clarifies the true meaning and limitations of the older perspectives on preferential solvation (such as solvent binding models, crowding, and OST), and enables excess number determination without any further assumptions. PMID:24689966

Shimizu, Seishi; Matubayasi, Nobuyuki

2014-04-10

362

Zero Tolerance Policies. ERIC Digest Number 146.  

ERIC Educational Resources Information Center

State legislatures and school boards are adopting a growing number of zero-tolerance polices toward weapons, guns, and violence. Zero-tolerance polices are rules intended to address specific school-safety issues. They have arisen in part as a response to the threat of the withdrawal of federal funds under the 1994 Gun-Free Schools Act, and…

McAndrews, Tobin

363

Random number generation deficit in early schizophrenia.  

PubMed

Random number generation with a written response mode provides a potentially appealing marker for executive processes. Impaired performance on written random number generation tasks has been reported in chronic schizophrenic patients. However, no study has investigated whether such a deficit occurs in early schizophrenia and whether its profile and severity are similar to those in patients with chronic illness. This study investigated the ability to generate random numbers in patients with early schizophrenia (n = 44) and a healthy control group (n = 48). Patients were less able to maintain several production strategies and generated more stereotyped response sequences, whereas their abilities to identify randomness with an even-handed treatment of digits and to monitor the equality of occurrence of single digits appeared to remain intact. These results provide evidence that some aspects of the deficits in random number generation among chronic schizophrenic patients are also present at early psychotic episode, while some other aspects are relatively less affected in the early years. PMID:21466082

Chan, Kevin Ka-Shing; Hui, Christy Lai-Ming; Tang, Jennifer Yee-Man; Chiu, Cindy Pui-Yu; Chan, Sherry Kit-Wa; Lam, May Mei-Ling; Chen, Eric Yu-Hai

2011-02-01

364

Fair bandwidth share using flow number estimation  

Microsoft Academic Search

We propose a novel active queue management mechanism, called flow number estimation (FNE), which is able to achieve network fair bandwidth share and tolerate burst traffic. FNE manages the length of a FIFO queue effectively and guarantees a reasonable queuing delay for every flow. The feature of traffic regulated by FNE is similar to that by the per-flow fair queuing

Jung-Shian Li; Ming-Shiann Leu

2002-01-01

365

Levels of Number Knowledge during Early Childhood  

ERIC Educational Resources Information Center

Researchers have long disagreed about whether number concepts are essentially continuous (unchanging) or discontinuous over development. Among those who take the discontinuity position, there is disagreement about how development proceeds. The current study addressed these questions with new quantitative analyses of children's incorrect responses…

Sarnecka, Barbara W.; Lee, Michael D.

2009-01-01

366

Vexillary Involutions are Enumerated by Motzkin Numbers  

Microsoft Academic Search

Vexillary permutations are very important for Schubert Polynomials. In this paper, we consider the enumeration of vexillary involutions, that is, 2143-avoiding involutions. Instead of solving the generating function obtained by a succession system characterizing vexillary involu- tions, we establish a one-to-one correspondence with 1-2 trees enumerated by Motzkin numbers.

O. Guibert; E. Pergola; R. Pinzani

2001-01-01

367

The aerodynamics of small Reynolds numbers  

NASA Technical Reports Server (NTRS)

Aerodynamic characteristics of wing model gliders and bird wings in particular are discussed. Wind tunnel measurements and aerodynamics of small Reynolds numbers are enumerated. Airfoil behavior in the critical transition from laminar to turbulent boundary layer, which is more important to bird wing models than to large airplanes, was observed. Experimental results are provided, and an artificial bird wing is described.

Schmitz, F. W.

1980-01-01

368

Automaticity of Two-Digit Numbers  

ERIC Educational Resources Information Center

Automatic processing of 2-digit numbers was demonstrated using the size congruency effect (SiCE). The SiCE indicates the processing of the irrelevant (numerical) dimension when 2 digits differing both numerically and physically are compared on the relevant (physical) dimension. The SiCE was affected by the compatibility between unit and decade…

Ganor-Stern, Dana; Tzelgov, Joseph; Ellenbogen, Ravid

2007-01-01

369

Polish Endocrinology. Volume 22, Number 3, 1971.  

National Technical Information Service (NTIS)

Contents: Growth dynamics of ovarian grafts in the kidneys and spleen of rats; Histological and morphometric studies on ovarian grafts in the kidneys and spleen in rats; Changes in the number of ovarian cells transplanted into the spleen in castrated fema...

1971-01-01

370

Determining the Number of Factors To Retain.  

ERIC Educational Resources Information Center

This paper presents four methods for determining the number of factors to retain: (1) determining an eigenvalue greater than unity (K1); (2) the scree test; (3) the minimum average parallel approach; and (4) parallel analysis. Three of the four methods are illustrated through an example. Although the eigenvalue greater than unity and the scree…

Tanguma, Jesus

371

A Framework for Remediating Number Combination Deficits  

ERIC Educational Resources Information Center

This article introduces a framework for the remediation of number combination (NC) deficits. Research on the remediation of NC deficits is summarized, and research program studies are used to illustrate the 3 approaches to remediation. The Framework comprises a 2-stage system of remediation. The less intensive stage implementing 1 of 3…

Fuchs, Lynn S.; Powell, Sarah R.; Seethaler, Pamela M.; Fuchs, Douglas; Hamlett, Carol L.; Cirino, Paul T.; Fletcher, Jack M.

2010-01-01

372

The Rheology of Finite Stokes Number Suspensions  

Microsoft Academic Search

This paper investigates the influence of particle inertia on the rheology and diffusive behavior of particulate suspensions. The Accelerated Stokesian Dynamics (ASD) simulation method (Sierou, N. & Brady, J.F. J. Fluid Mech.) (in press). in which hydrodynamic interactions among particles at low Reynolds number are calculated accurately and efficiently in O (N log N) operations is modified to allow for

Zhiwu Fang; John Brady

2001-01-01

373

Science Sampler: Pick-a-number  

NSDL National Science Digital Library

The Pick-a-number activity, a variation of the game 20 Questions, provides a way to address challenges at the beginning of the school year, in a standards-based way. It also helps students develop the essential skill of asking questions as part of the scientific inquiry process.

Sitzman, Daniel

2005-09-01

374

Question Number Two: How Many Factors?  

ERIC Educational Resources Information Center

Exploratory factor analysis involves five key decisions. The second decision, how many factors to retain, is the focus of the current paper. Extracting too many or too few factors often leads to devastating effects on study results. The advantages and disadvantages of the most effective and/or most utilized strategies to determine the number of…

Goodwyn, Fara

2012-01-01

375

Algebra Magic- Make your own Numbers Puzzle  

NSDL National Science Digital Library

This resource provides an explanation of two number/magic puzzles that can be demystified and explained by using algebra. This resource is from PUMAS - Practical Uses of Math and Science - a collection of brief examples created by scientists and engineers showing how math and science topics taught in K-12 classes have real world applications.

376

Law of Large Numbers-Hospital  

NSDL National Science Digital Library

This activity discusses probability topics, such as: sample space, independent events, Law of Large Numbers, deviation percentage. The resource is structured in a seven step process, these steps include: probability topics, assumed prior experience, rationale, learning objectives, materials and technology needed, procedure, and finally, assessment. An Excel-like program is required for this activity, which can be reached via the website.

2009-03-20

377

Combinatorics of generalized q-Euler numbers  

Microsoft Academic Search

New enumerating functions for the Euler numbers are considered. Sev- eral of the relevant generating functions appear in connection to entries in Ramanu- jan's Lost Notebook. The results presented here are, in part, a response to a conjec- ture made by M. E. H. Ismail and C. Zhang about the symmetry of polynomials in Ramanujan's expansion for a generalization of

Tim Huber; Ae Ja Yee

2010-01-01

378

How Can Syntax Support Number Word Acquisition?  

ERIC Educational Resources Information Center

We expand upon a previous proposal by Bloom and Wynn (1997) that young children learn about the meaning of number words by tracking their occurrence in particular syntactic environments, in combination with the discourse context in which they are used. An analysis of the Childes database (MacWhinney, 2000) reveals that the environments studied by…

Syrett, Kristen; Musolino, Julien; Gelman, Rochel

2012-01-01

379

Modeling the Number of Active Software Users  

Microsoft Academic Search

More and more software applications are developed within a software ecosystem (SECO), such as the Face book ecosystem and the iPhone AppStore. A core asset of a software ecosystem is its users, and the behavior of the users strongly affects the decisions of software vendors. The number of active users reflects user satisfaction and quality of the applications in a

Da Yang; Wenpei Liu; Qiang Cui; Juan Li; Ye Yang; Qing Wang

2011-01-01

380

Mass-induced transition in fermion number  

SciTech Connect

We show that if we increase the mass of fermions in interaction with a topological (kink) scalar background in 1+1 dimensions, the fractional fermion number of the system will eventually vanish. The transition is sharp and corresponds to the disappearance of localized states from the spectrum of a Dirac operator which is exactly solvable. Possible applications to different physical systems are discussed.

Aragao de Carvalho, C.; Pureza, J. M.

1989-05-15

381

Probability and the Law of Large Numbers  

NSDL National Science Digital Library

This probability activity guides students to discover the law of large numbers by having them consider why flipping a coin multiple times does not always produce equal results. The activity includes a 3 minute video featuring Bianca from Cyberchase, a document for data collection, and two assessment options (rtf format).

2012-01-01

382

A Fast Number Theoretic Finite Radon Transform  

Microsoft Academic Search

This paper presents a new fast method to map between images and their digital projections based on the Number Theoretic Transform (NTT) and the Finite Radon Transform (FRT). The FRT is a Discrete Radon Transform (DRT) defined on the same finite geometry as the Finite or Discrete Fourier Transform (DFT). Consequently, it may be inverted directly and exactly via the

Shekhar Chandra; Imants D. Svalbe

2009-01-01

383

How Do Students Misunderstand Number Representations?  

ERIC Educational Resources Information Center

We used both student interviews and diagnostic testing to reveal students' misconceptions about number representations in computing systems. This article reveals that students who have passed an undergraduate level computer organization course still possess surprising misconceptions about positional notations, two's complement representation, and…

Herman, Geoffrey L.; Zilles, Craig; Loui, Michael C.

2011-01-01

384

Sustaining Student Numbers in the Competitive Marketplace  

ERIC Educational Resources Information Center

The climate of competition for students in the higher education sector makes it imperative that institutions increase their marketing efforts, both domestically and internationally, to help sustain student numbers. In Australia, the Bradley Report and the government response, which will do away with quotas, allows for a much freer market than…

Szekeres, Judy

2010-01-01

385

Interval algorithm for random number generation  

Microsoft Academic Search

The problem of generating a random number with an arbitrary probability distribution by using a general biased M-coin is studied. An efficient and very simple algorithm based on the successive refinement of partitions of the unit interval (0, 1), which we call the interval algorithm, is proposed. A fairly tight evaluation on the efficiency is given. Generalizations of the interval

Te Sun Han; Mamoru Hoshi

1997-01-01

386

Fourier Analysis of Uniform Random Number Generators  

Microsoft Academic Search

A method of analysis of uniform random number generators is developed, applicable to almost all practical methods of generation. The method is that of Fourier analysis of the output sequences of such generators. With this tool it is possible to understand and predict relevant statistical properties of such generators and compare and evaluate such methods. Many such analyses and comparisons

R. R. Coveyou; R. D. Macpherson

1967-01-01

387

Toward a universal random number generator  

Microsoft Academic Search

This article describes an approach towards a random number generator that passes all of the stringent tests for randomness we have put to it, and that is able to produce exactly the same sequence of uniform random variables in a wide variety of computers, including TRS80, Apple, Macintosh, Commodore, Kaypro, IBM PC, AT, PC and AT clones, Sun, Vax, IBM

George Marsaglia; Arif Zaman; Wai Wan Tsang

1990-01-01

388

Random numbers certified by Bell's theorem.  

PubMed

Randomness is a fundamental feature of nature and a valuable resource for applications ranging from cryptography and gambling to numerical simulation of physical and biological systems. Random numbers, however, are difficult to characterize mathematically, and their generation must rely on an unpredictable physical process. Inaccuracies in the theoretical modelling of such processes or failures of the devices, possibly due to adversarial attacks, limit the reliability of random number generators in ways that are difficult to control and detect. Here, inspired by earlier work on non-locality-based and device-independent quantum information processing, we show that the non-local correlations of entangled quantum particles can be used to certify the presence of genuine randomness. It is thereby possible to design a cryptographically secure random number generator that does not require any assumption about the internal working of the device. Such a strong form of randomness generation is impossible classically and possible in quantum systems only if certified by a Bell inequality violation. We carry out a proof-of-concept demonstration of this proposal in a system of two entangled atoms separated by approximately one metre. The observed Bell inequality violation, featuring near perfect detection efficiency, guarantees that 42 new random numbers are generated with 99 per cent confidence. Our results lay the groundwork for future device-independent quantum information experiments and for addressing fundamental issues raised by the intrinsic randomness of quantum theory. PMID:20393558

Pironio, S; Acín, A; Massar, S; de la Giroday, A Boyer; Matsukevich, D N; Maunz, P; Olmschenk, S; Hayes, D; Luo, L; Manning, T A; Monroe, C

2010-04-15

389

Tutoring Large Numbers: An Unmet Challenge  

ERIC Educational Resources Information Center

Open and distance learning (ODL) is increasingly being regarded as a viable policy option for developing countries with limited educational resources for buildings, books and trained teachers, seeking to increase accessibility for large numbers of learners in education and training opportunities. Advocates of ODL as an appropriate solution to…

Lentell, Helen; O'Rourke, Jennifer

2004-01-01

390

Positive Pinching, Volume and Second Betti Number  

Microsoft Academic Search

.   Our main theorem asserts that for all odd\\u000a \\u000a and 0 , there exists a small constant, , such that if a simply connected n-manifold, M, with vanishing second Betti number admits a metric of sectional curvature, , then the injectivity radius of M is greater than .

F. Fang; X. Rong

1999-01-01

391

A Large Re-Number Aerodynamic Assembly.  

National Technical Information Service (NTIS)

The report describes an apparatus for large Reynolds numbers (Re), working on compressed air. The apparatus contains a balloon battery, a fore-chamber, a nozzle, a working element, a diffuser, and low-pressure gas containers. To provide for the secondary ...

A. I. Tishkov A. B. Lyakhov L. N. Novikov

1969-01-01

392

University Admissions. Policy Note. Number 3  

ERIC Educational Resources Information Center

University admissions, like many other aspects of the higher education sector, are going through a time of significant change. From 2012, universities will receive full funding under the Commonwealth Grants Scheme (CGS) for as many places as they offer. Previously, the Government limited the number of funded places, with a tolerance band for…

Group of Eight (NJ1), 2012

2012-01-01

393

MHD dynamos at low magnetic Prandtl number  

NASA Astrophysics Data System (ADS)

The generation of magnetic fields in celestial bodies occurs in media with very different kinematic viscosity and magnetic diffusivity. At the same time, the Reynolds numbers may be very large, with complex turbulent flows being responsible for the magnetic field amplification. We present a three-pronged numerical approach to the dynamo problem of generation of magnetic fields at small magnetic Prandtl numbers. The numerical difficulty of needing to resolve a large range of relevant scales is circumvented by combining direct numerical simulations (DNS), a Lagrangian-averaged model (the ``alpha model'' of D. Holm and collaborators), and large-eddy simulations (LES) of the MHD equations. The flow under investigation is forced by a Taylor-Green vortex term, similarly to several laboratory experiments on liquid metals. When possible, we performed overlapping simulations with the different numerical methods to ensure consistency of the results. The existence of a critical value of the magnetic Reynolds number for the exponential growth of magnetic energy was explored. Magnetic Prandtl numbers down to 0.1 and smaller were reached, and at all values explored, a dynamo threshold was found.

Ponty, Y.; Mininni, P.; Montgomery, D. C.; Pinton, J.-F.; Politano, H.; Pouquet, A.

2004-11-01

394

MHD dynamos at low magnetic Prandtl number  

Microsoft Academic Search

The generation of magnetic fields in celestial bodies occurs in media with very different kinematic viscosity and magnetic diffusivity. At the same time, the Reynolds numbers may be very large, with complex turbulent flows being responsible for the magnetic field amplification. We present a three-pronged numerical approach to the dynamo problem of generation of magnetic fields at small magnetic Prandtl

Y. Ponty; P. Mininni; D. C. Montgomery; J.-F. Pinton; H. Politano; A. Pouquet

2004-01-01

395

Very high Mach number shocks: theory  

SciTech Connect

The theory and simulation of collisionless perpendicular supercritical shock structure is reviewed, with major emphasis on recent research results. The primary tool of investigation is the hybrid simulation method, in which the Newtonian orbits of a large number of ion macroparticles are followed numerically, and in which the electrons are treated as a charge neutralizing fluid. The principal results to be presented are (1) electron resistivity is not required to explain the observed quasi-stationarity of the earth's bow shock, (2) the structure of the perpendicular shock at very high Mach numbers (M/sub A/ approx. = 15 - 20 and ..beta.. approx. = 1, where M/sub A/ is the Alfven Mach number of the shock and ..beta.. is the ratio of the thermal to magnetic pressure) depends sensitively on the upstream ..beta.. and electron resistivity, (3) two-dimensional turbulence will become increasingly important as the Mach number is increased, and (4) non-adiabatic bulk electron heating will result when a thermal electron cannot complete a gyro-orbit while transiting the shock. 32 refs., 13 figs.

Quest, K.B.

1986-01-01

396

Environmental performance: an index number approach  

Microsoft Academic Search

Tyteca [J. Environ. Manage. 46 (1996) 281] reviews the literature on environmental performance indicators. In that paper he calls for an index that simultaneously accounts for resources used, good outputs produced and pollutants or undesirable outputs emitted. Here, we provide a formal index number of environmental performance which can be computed using data envelopment analysis (DEA) techniques. The implicit benchmark

R. Färe; S. Grosskopf; F. Hernandez-Sancho

2004-01-01

397

Sequence Factorial of "g"-Gonal Numbers  

ERIC Educational Resources Information Center

The gamma function, which has the property to interpolate the factorial whenever the argument is an integer, is a special case (the case "g"?=?2) of the general term of the sequence factorial of "g"-gonal numbers. In relation to this special case, a formula for calculating the general term of the sequence factorial of any…

Asiru, Muniru A.

2013-01-01

398

Magnetic Particle Recovery of Serial Numbers  

SciTech Connect

One method used by crime labs to recover obliterated serial numbers in steel firearms (ferrous samples) is the magnetic particle technique. The use of this method is predicated on the detection of metal deformation present under stamped serial numbers after the visible stamp has been removed. Equipment specialized for this detection is not used in these attempts; a portable magnetic yoke used typically for flaw detection on large weldments or structures, along with dry visible magnetic powders, have been the tools of criminologists working in this area. Crime labs have reported low success rates using these tools [1, 2]. This is not surprising when one considers that little formal development has apparently evolved for use in such investigations since the publication of seminal work in this area some time ago [3]. The aim of this project is to investigate specific aspects of magnetic particle inspection for serial number recovery. This includes attempts to understand the magnetic characteristics of different steels that affect their performance in the test, such as varying results for carbon steels and alloy steels after different thermal and forming treatments. Also investigated are the effects of the nature of the sample magnetization (AC, rectified DC, and true DC) and the use of various detection media, such as visible powders and fluorescent sprays, on test outcome. Additionally, some aspects of surface preparation of firearm samples prior to number recovery were included in this work. The scope of this report includes a brief overview of the magnetic particle inspection method in general and its applications to forensic serial number recovery. This is followed by a description of how such investigations were simulated on lab samples, including a look at how the microstructure of a given steel will affect its performance in the test. Investigations into the serial number recovery in a series of ferromagnetic firearms (both steel and certain stainless steels) will then be presented. Recommendations for modifications to current approaches used in crime labs for serial number recovery, as well as suggestions for future work, conclude this document.

D. Utrata; M.J. Johnson

2003-10-01

399

MHD Turbulence at Moderate Magnetic Reynolds Number  

NASA Technical Reports Server (NTRS)

In the present article we will consider the decay of MHD turbulence under the influence of a strong external magnetic field at moderate magnetic Reynolds numbers. Typical values of R(sub m) that are considered here range from R(sub m) approx. 0.1 to R(sub m) approx. 20. As a comparison, the initial kinetic Reynolds number common to all our simulations is Re(sub L) = 199. This means that the range of Prandtl numbers explored is 5 x 10(exp -4) to 10(exp -1). Our motivation is mainly to exhibit how the transition from the QS approximation to FMHD occurs. At the lowest values of R(sub m) studied here, the QS approximation is shown to model the flow faithfully. However, for the higher values of R(sub m) considered, it is clearly inadequate but can be replaced by another approximation which will be referred to as the Quasi-Linear (QL) approximation. Another objective of the present study is to describe how variations in the magnetic Reynolds number (while maintaining all other parameters constant) affect the dynamics of the flow. This complements past studies where variations in either the strength of the external magnetic field or the kinetic Reynolds number were considered. This article is organized as follows. In section 2 we recall the definition of the quasi-static approximation. Section 3 is devoted to the description of the numerical experiments performed using the quasi-static approximation and full MHD. In section 4 we describe the quasi-linear approximation and test it numerically against full MHD. A concluding summary is given in section 5.

Knaepen, B.; Kassinos, S.; Carati, D.

2003-01-01

400

BioNumbers--the database of key numbers in molecular and cell biology  

PubMed Central

BioNumbers (http://www.bionumbers.hms.harvard.edu) is a database of key numbers in molecular and cell biology—the quantitative properties of biological systems of interest to computational, systems and molecular cell biologists. Contents of the database range from cell sizes to metabolite concentrations, from reaction rates to generation times, from genome sizes to the number of mitochondria in a cell. While always of importance to biologists, having numbers in hand is becoming increasingly critical for experimenting, modeling, and analyzing biological systems. BioNumbers was motivated by an appreciation of how long it can take to find even the simplest number in the vast biological literature. All numbers are taken directly from a literature source and that reference is provided with the number. BioNumbers is designed to be highly searchable and queries can be performed by keywords or browsed by menus. BioNumbers is a collaborative community platform where registered users can add content and make comments on existing data. All new entries and commentary are curated to maintain high quality. Here we describe the database characteristics and implementation, demonstrate its use, and discuss future directions for its development.

Milo, Ron; Jorgensen, Paul; Moran, Uri; Weber, Griffin; Springer, Michael

2010-01-01

401

The approximate number system is not predictive for symbolic number processing in kindergarteners.  

PubMed

The relation between the approximate number system (ANS) and symbolic number processing skills remains unclear. Some theories assume that children acquire the numerical meaning of symbols by mapping them onto the preexisting ANS. Others suggest that in addition to the ANS, children also develop a separate, exact representational system for symbolic number processing. In the current study, we contribute to this debate by investigating whether the nonsymbolic number processing of kindergarteners is predictive for symbolic number processing. Results revealed no association between the accuracy of the kindergarteners on a nonsymbolic number comparison task and their performance on the symbolic comparison task six months later, suggesting that there are two distinct representational systems for the ANS and numerical symbols. PMID:23767979

Sasanguie, Delphine; Defever, Emmy; Maertens, Bieke; Reynvoet, Bert

2014-02-01

402

Comparison of the Variations of Sunspot Number, Number of Sunspot Groups, and Sunspot Area, 1875 -2013  

NASA Technical Reports Server (NTRS)

Examined are the yearly variations and ratios of sunspot number, the number of sunspot groups, and the total corrected sunspot area for the interval 1875-2013. While yearly sunspot number independently correlates strongly (r = 0.98) with the yearly number of sunspot groups (y = -2 + 11.99x) and the total corrected sunspot area (y = 5 + 0.059x), the strongest correlation (Ry12 = 0.99) is the one based on the bivariate fit of sunspot number against the combined variations of the number of sunspot groups and sunspot area (y = 1 + 5.88x1 + 0.031x2, where y refers to sunspot number, x1 refers to the number of sunspot groups, and x2 refers to the sunspot area). While all cycle minima based on the bivariate fit are concurrent with the observed minimum in sunspot number, cycle maxima are sometimes found to differ. For sunspot cycles 12, 19, 20, and 23, cycle maximum is inferred to have occurred in 1884, 1958, 1970, and 2002, respectively, rather than in 1883, 1957, 1968, and 2000, based on the observed sunspot number. Also, cycle 19's maximum amplitude based on observed sunspot number seems too high in comparison to that found using the bivariate fit. During the 139-year interval 1875-2013, the difference between the observed and predicted sunspot number based on the bivariate fit is <1 standard error of estimate (se) (<6.4) for 111 years, between 1 and <2 se (6.4 to <12.8) for 28 years, and =2 se (=12.8) for only 4 years, these years being 1957 (16.6), 1978 (-15.8), 1980 (23), and 1982 (-16.3). For sunspot cycle 24, the difference between observed and predicted values has been only -0.7 and 3.2 (=0.5 se).

Wilson, Robert M.

2014-01-01

403

Manipulating number generation: loud + long = large?  

PubMed

Humans make numerous choices every day and tend to perceive these choices as free. The present study shows how simple free choices are biased by experiencing unrelated auditory information. In two experiments, participants categorized tones according to their intensity on the dimensions volume and duration on the majority of trials. On some trials, however, they were to randomly generate a number, and we found these choices to be influenced by tone intensity. Particularly, if participants were cued toward volume, loud tones clearly biased participants to generate larger numbers. For tone duration, a similar effect only emerged if spatial information was reinforced by the motor context of the task. The findings extend previous findings relating to the ATOM framework (A Theory of Magnitude) by an explicit focus on auditory magnitude processing. As such, they also constrain ATOM by showing that the connections between different magnitude dimensions vary to a considerable degree. PMID:24076426

Heinemann, Alexander; Pfister, Roland; Janczyk, Markus

2013-12-01

404

AMR for low Mach number reacting flow  

SciTech Connect

We present a summary of recent progress on the development and application of adaptive mesh refinement algorithms for low Mach number reacting flows. Our approach uses a form of the low Mach number equations based on a general equation of state that discretely conserves both mass and energy. The discretization methodology is based on a robust projection formulation that accommodates large density contrasts. The algorithm supports modeling of multicomponent systems and incorporates an operator-split treatment of stiff reaction terms. The basic computational approach is embedded in an adaptive projection framework that uses structured hierarchical grids with subcycling in time that preserves the discrete conservation properties of the underlying single-grid algorithm. We present numerical examples illustrating the application of the methodology to turbulent premixed combustion and nuclear flames in type Ia supernovae.

Bell, John B.

2004-01-16

405

Finite-particle-number approach to physics  

SciTech Connect

Starting from a discrete, self-generating and self-organizing, recursive model and self-consistent interpretive rules we construct: the scale constants of physics (3,10,137,1.7x10/sup 38/); 3+1 Minkowski space with a discrete metric and the algebraic bound ..delta.. is an element of ..delta.. tau is greater than or equal to 1; the Einstein-deBroglie relation; algebraic double slit interference; a single-time momentum-space scattering theory connected to laboratory experience; an approximation to wave functions; local phase severance and hence both distant correlations and separability; baryon number, lepton number, charge and helicity; m/sub p//m/sub e/; a cosmology not in disagreement with current observations.

Noyes, H.P.

1982-10-01

406

Entanglement distillation protocols and number theory  

SciTech Connect

We show that the analysis of entanglement distillation protocols for qudits of arbitrary dimension D benefits from applying basic concepts from number theory, since the set Z{sub D}{sup n} associated with Bell diagonal states is a module rather than a vector space. We find that a partition of Z{sub D}{sup n} into divisor classes characterizes the invariant properties of mixed Bell diagonal states under local permutations. We construct a very general class of recursion protocols by means of unitary operations implementing these local permutations. We study these distillation protocols depending on whether we use twirling operations in the intermediate steps or not, and we study them both analytically and numerically with Monte Carlo methods. In the absence of twirling operations, we construct extensions of the quantum privacy algorithms valid for secure communications with qudits of any dimension D. When D is a prime number, we show that distillation protocols are optimal both qualitatively and quantitatively.

Bombin, H.; Martin-Delgado, M.A. [Departamento de Fisica Teorica I, Universidad Complutense, 28040 Madrid (Spain)

2005-09-15

407

Completeness of †-categories and the complex numbers  

NASA Astrophysics Data System (ADS)

The complex numbers are an important part of quantum theory, but are difficult to motivate from a theoretical perspective. We describe a simple formal framework for theories of physics, and show that if a theory of physics presented in this manner satisfies certain completeness properties, then it necessarily includes the complex numbers as a mathematical ingredient. Central to our approach are the techniques of category theory, and we introduce a new category-theoretical tool, called the †-limit, which governs the way in which systems can be combined to form larger systems. These †-limits can be used to characterize the properties of the †-functor on the category of finite-dimensional Hilbert spaces, and so can be used as an equivalent definition of the inner product. One of our main results is that in a nontrivial monoidal †-category with finite †-limits and a simple tensor unit, the semiring of scalars embeds into an involutive field of characteristic 0 and orderable fixed field.

Vicary, Jamie

2011-08-01

408

Sensitivity in risk analyses with uncertain numbers.  

SciTech Connect

Sensitivity analysis is a study of how changes in the inputs to a model influence the results of the model. Many techniques have recently been proposed for use when the model is probabilistic. This report considers the related problem of sensitivity analysis when the model includes uncertain numbers that can involve both aleatory and epistemic uncertainty and the method of calculation is Dempster-Shafer evidence theory or probability bounds analysis. Some traditional methods for sensitivity analysis generalize directly for use with uncertain numbers, but, in some respects, sensitivity analysis for these analyses differs from traditional deterministic or probabilistic sensitivity analyses. A case study of a dike reliability assessment illustrates several methods of sensitivity analysis, including traditional probabilistic assessment, local derivatives, and a ''pinching'' strategy that hypothetically reduces the epistemic uncertainty or aleatory uncertainty, or both, in an input variable to estimate the reduction of uncertainty in the outputs. The prospects for applying the methods to black box models are also considered.

Tucker, W. Troy; Ferson, Scott

2006-06-01

409

Randomized Parallel Proof-Number Search  

NASA Astrophysics Data System (ADS)

Proof-Number Search (PNS) is a powerful method for solving games and game positions. Over the years, the research on PNS has steadily produced new insights and techniques. With multi-core processors becoming established in the recent past, the question of parallelizing PNS has gained new urgency. This article presents a new technique called Randomized Parallel Proof-Number Search (RPPNS) for parallelizing PNS on multi-core systems with shared memory. The parallelization is based on randomizing the move selection of multiple threads, which operate on the same search tree. RPPNS is tested on a set of complex Lines-of-Action endgame positions. Experiments show that RPPNS scales well. Four directions for future research are given.

Saito, Jahn-Takeshi; Winands, Mark H. M.; van den Herik, H. Jaap

410

Number processing in temporal lobe epilepsy  

PubMed Central

Objective: To investigate deficits in number processing in patients with TLE. Methods: Numerical abilities were assessed in 28 right handed patients with medically intractable unilateral TLE and in a control group. Results: No differences between patients and controls were found in analogue number processing with Arabic input, in a comparison task, or in simple addition and simple subtraction; however, there were significant group differences in tasks with verbal input, in simple division, in complex mental calculation, in a semantic knowledge task, and in conceptual tasks. Only minor differences were found between patients with right and left TLE. Conclusions: While numerical deficits may be expected in patients with left sided TLE, it is open for discussion why patients with right sided TLE also show numerical deficits.

Delazer, M; Gasperi, A; Bartha, L; Trinka, E; Benke, T

2004-01-01

411

Optimal number of pigments in photosynthetic complexes  

NASA Astrophysics Data System (ADS)

We study excitation energy transfer in a simple model of a photosynthetic complex. The model, described by the Lindblad equation, consists of pigments interacting via dipole-dipole interaction. The overlapping of pigments induces an on-site energy disorder, providing a mechanism for blocking the excitation transfer. Based on the average efficiency as well as the robustness of random configurations of pigments, we calculate the optimal number of pigments that should be enclosed in a pigment-protein complex of a given size. The results suggest that a large fraction of pigment configurations are efficient as well as robust if the number of pigments is properly chosen. We compare the optimal results of the model to the structure of pigment-protein complexes as found in nature, finding good agreement.

Jesenko, Simon; Žnidari?, Marko

2012-09-01

412

Number Patterns Fun with Curves & Topology  

NSDL National Science Digital Library

Educational consultant and textbook author Jill Britton is the author of these metasites listing Web resources for grade 5-8 mathematics. Each metasite revolves around a certain topic. For instance, the first site, Number Patterns Fun with Curves & Topology, is an index of eighteen subtopics such as prime numbers, the golden ratio, Pascal's Triangle, mazes and maps, etc. Under each subtopic, an annotated list of Web resources (from other authors and organizations) points to tutorials and fun activities for students as well as printable activity sheets and lesson plans for teachers. Other types of links given on these pages are to merchants selling educational materials, sites on the history of mathematics, and activities with holiday themes.

Britton, Jill.

2001-01-01

413

DNS PseudoRandom Number Generators Weakness  

Microsoft Academic Search

\\u000a In article [1] we presented the results of analysis of well-known weakness of some DNS servers: poor quality of pseudo-random\\u000a numbers generators (PRNG), which makes it possible to hack them using the birthday attack. In this article we present extended\\u000a analysis of current DNS servers: DNS build in Windows 2003 server with SP2, DNS from Windows 2008 server with SP2 and

Maciej Szmit; Anna Szmit

414

Fractions on the number line (grade 3)  

NSDL National Science Digital Library

This is a sample PARCC assessment task based on CCSS grade 3 fraction standards. In this interactive five-part task students reason about fractions used to represent part of a whole or a location on a number line, compare fractions with and without models, and construct arguments to defend their decisions. Included are the alignments to the CCSS, a scoring rubric, and background on the task itself.

2013-01-01

415

Galois number fields with small root discriminant  

Microsoft Academic Search

We pose the problem of identifying the set K(G,?) of Galois number fields with given Galois group G and root discriminant less than the Serre constant ??44.7632. We definitively treat the cases G=A4, A5, A6 and S4, S5, S6, finding exactly 59, 78, 5 and 527, 192, 13 fields, respectively. We present other fields with Galois group SL3(2), A7, S7,

John W. Jones; David P. Roberts

2007-01-01

416

The Number of Shortest Paths in the  

Microsoft Academic Search

\\u000a We enumerate all of the shortest paths between any vertex v and the identity vertex in an (n, k)-star graph by enumerating the minimum factorizations of v in terms of the transpositions corresponding to edges in that graph. This result generalizes a previous one for the star\\u000a graph, and can be applied to obtain the number of the shortest paths

Eddie Cheng; Ke Qiu; Zhi Zhang Shen

2010-01-01

417

Trialogue on the number of fundamental constants  

NASA Astrophysics Data System (ADS)

This paper consists of three separate articles on the number of fundamental dimensionful constants in physics. We started our debate in summer 1992 on the terrace of the famous CERN cafeteria. In the summer of 2001 we returned to the subject to find that our views still diverged and decided to explain our current positions. LBO develops the traditional approach with three constants, GV argues in favor of at most two (within superstring theory), while MJD advocates zero.

Duff, Michael J.; Okun, Lev B.; Veneziano, Gabriele

2002-03-01

418

Sequences of Rational Numbers Converging to Surds  

ERIC Educational Resources Information Center

In this sequence 1/1, 7/5, 41/29, 239/169 and so on, Thomas notes that the sequence converges to square root of 2. By observation, the sequence of numbers in the numerator of the above sequence, have a pattern of generation which is the same as that in the denominator. That is, the next term is found by multiplying the previous term by six and…

Fletcher, Rodney

2010-01-01

419

Cold spray nozzle mach number limitation  

Microsoft Academic Search

The classic one-dimensional isentropic flow approach is used along with a two-dimensional axisymmetric numerical model to\\u000a show that the exit Mach number of a cold spray nozzle should be limited due to two factors. To show this, the two-dimensional\\u000a model is validated with experimental data. Although both models show that the stagnation temperature is an important limiting\\u000a factor, the one-dimensional

B. Jodoin

2002-01-01

420

Genomic characteristics of cattle copy number variations  

Microsoft Academic Search

Background  Copy number variation (CNV) represents another important source of genetic variation complementary to single nucleotide polymorphism\\u000a (SNP). High-density SNP array data have been routinely used to detect human CNVs, many of which have significant functional\\u000a effects on gene expression and human diseases. In the dairy industry, a large quantity of SNP genotyping results are becoming\\u000a available and can be used

Yali Hou; George E Liu; Derek M Bickhart; Maria Francesca Cardone; Kai Wang; Eui-soo Kim; Lakshmi K Matukumalli; Mario Ventura; Jiuzhou Song; Paul M VanRaden; Tad S Sonstegard; Curt P Van Tassell

2011-01-01

421

Detecting Prime Numbers via Roots of Polynomials  

ERIC Educational Resources Information Center

It is proved that an integer n [greater than or equal] 2 is a prime (resp., composite) number if and only if there exists exactly one (resp., more than one) nth-degree monic polynomial f with coefficients in Z[subscript n], the ring of integers modulo n, such that each element of Z[subscript n] is a root of f. This classroom note could find use in…

Dobbs, David E.

2012-01-01

422

Efficient View Maintenance Using Version Numbers  

Microsoft Academic Search

Maintaining a materialized view in an environment of multiple, distributed, autonomous data sources is a challenging issue.\\u000a The results of incremental computation are effected by interfering updates and compensation is required. In this paper, we\\u000a improve the incremental computation proposed in our previous work by making it more efficient through the use of data source\\u000a and refreshed version numbers. This

Eng Koon Sze; Tok Wang Ling

2001-01-01

423

Utility Priority Number Evaluation for FMEA  

Microsoft Academic Search

Traditionally, decisions on how to improve an operation are based on risk priority number (RPN) in the failure mode and effects\\u000a analysis (FMEA). Many scholars questioned the RPN method and proposed some new methods to improve the decision process, but\\u000a these methods are only measuring from the risks viewpoint while ignoring the importance of corrective actions. The corrective\\u000a actions may

Jih Kuang Chen

2007-01-01

424

Locating Fraction on a Number Line  

ERIC Educational Resources Information Center

Based on a survey of 3067 Finnish 5th and 7th graders and a task-based interview of 20 7th graders we examine student's understanding of fraction. Two tasks frame a specific fraction (3/4) in different contexts: as part of an eight-piece bar (area context) and as a location on a number line. The results suggest that students' understanding of…

Hannula, Markku S.

2003-01-01

425

On the Decimal Numbers Base "n"  

ERIC Educational Resources Information Center

This paper focuses on the representation of a proper fraction "a"/"b" by a decimal number base "n" where "n" is any integer greater than 1. The scope is narrowed to look at only fractions where "a","b" are positive integers with "a" less than "b" and "b" not equal to 0 nor equal to 1. Some relationships were found between "b" and "n", which…

Poon, K.-K.; Yeung, K.-W.; Shiu, W.-C.

2005-01-01

426

Efficient scaling in the residue number system  

Microsoft Academic Search

A unified residue number system scaling technique that allows the designer a great deal of flexibility in choosing the scale factor is presented. The technique is based on the L(ε+?)-CRT (Chinese remainder theorem). By embedding the scaling process in the CRT, the L(ε+?)-CRT can also be used to simplify the residue-to-analog conversion problem. The flexibility in choosing the scale factor

M. Griffin; Mike Sousa; Fred Taylor

1989-01-01

427

Identification numbers, hazardous substances, international descriptions  

SciTech Connect

The US Materials Transportation Bureau has postponed the voluntary compliance date for display of identification numbers on placards and use of the Optional Hazardous Materials Table, following a review of petitions for reconsideration. The rule will become effective on 11/20/80. The Association of American Railroads and Southern Railway Co. petitions are reprinted. A public hearing will be held in Washington, DC, on 7/31/89.

Not Available

1980-06-30

428

Distribution of the number of consecutive records  

Microsoft Academic Search

We study the distribution of the number n;r of r consecutive records in a sequence of n independent and identically distributed random variables from a common continuous distribution, or equivalently, in a random permutation ofn elements. We show that the asymptotic distribution of n;r is Poisson for r = 1; 2 and non-Poisson for r 3. Precise asymptotic results are

Hua-huai Chern; Hsien-kuei Hwang; Yeong-nan Yeh

2000-01-01

429

Number of Spanning Trees in Multigraph Wheels  

Microsoft Academic Search

Taking the graph called the wheelW_{n}as the join ofK_{1}andC_{n}, we consider it along with three multigraph variations. A recursion formula for the number of spanning trees inW_{n}, T_{n} = 3T_{n-1}-T_{n-2} + 2, and other pertinent formulas are presented. A related resistance network problem is also discussed briefly.

S. Bedrosian

1972-01-01

430

A recursion equation for prime numbers  

Microsoft Academic Search

It is shown that the first $n$ prime numbers $p_1,...,p_n$ determine the next one by the recursion equation $$ p_{n+1} =\\\\lim\\\\limits_{s\\\\to +\\\\infty} [\\\\prod\\\\limits^n_{k=1} (1-\\\\frac{1}{p^s_k}) \\\\sum\\\\limits^\\\\infty_{j=1} \\\\frac{1}{j^s} -1]^{-1\\/s}. $$ The upper limit on the sum can be replaced by $2p_n -1$, and the result still holds.

Joseph B. Keller

2007-01-01

431

Hydromagnetic Flow Past an Exponentially Accelerated Isothermal Vertical Plate with Uniform Mass Diffusion in the Presence of Chemical Reaction of first Order  

NASA Astrophysics Data System (ADS)

An exact solution of an unsteady flow past an exponentially accelerated infinite isothermal vertical plate with uniform mass diffusion in the presence of a transverse magnetic field has been studied. The plate temperature is raised to Tw and the species concentration level near the plate is also made to rise C?w . The dimensionless governing equations are solved using the Laplace-transform technique. The velocity, temperature and concentration profiles are studied for different physical parameters such as the magnetic field parameter, chemical reaction parameter, thermal Grashof number, mass Grashof number, Schmidt number, time and a. It is observed that the velocity decreases with increasing the magnetic field parameter.

Muthucumaraswamy, R.; Valliammal, V.

2013-03-01

432

Nowcasting sunshine number using logistic modeling  

NASA Astrophysics Data System (ADS)

In this paper, we present a formalized approach to statistical modeling of the sunshine number, binary indicator of whether the Sun is covered by clouds introduced previously by Badescu (Theor Appl Climatol 72:127-136, 2002). Our statistical approach is based on Markov chain and logistic regression and yields fully specified probability models that are relatively easily identified (and their unknown parameters estimated) from a set of empirical data (observed sunshine number and sunshine stability number series). We discuss general structure of the model and its advantages, demonstrate its performance on real data and compare its results to classical ARIMA approach as to a competitor. Since the model parameters have clear interpretation, we also illustrate how, e.g., their inter-seasonal stability can be tested. We conclude with an outlook to future developments oriented to construction of models allowing for practically desirable smooth transition between data observed with different frequencies and with a short discussion of technical problems that such a goal brings.

Brabec, Marek; Badescu, Viorel; Paulescu, Marius

2013-04-01

433

Tidal Love Numbers of Neutron Stars  

SciTech Connect

For a variety of fully relativistic polytropic neutron star models we calculate the star's tidal Love number k{sub 2}. Most realistic equations of state for neutron stars can be approximated as a polytrope with an effective index n {approx} 0.5-1.0. The equilibrium stellar model is obtained by numerical integration of the Tolman-Oppenheimer-Volkhov equations. We calculate the linear l = 2 static perturbations to the Schwarzschild spacetime following the method of Thorne and Campolattaro. Combining the perturbed Einstein equations into a single second-order differential equation for the perturbation to the metric coefficient g{sub tt} and matching the exterior solution to the asymptotic expansion of the metric in the star's local asymptotic rest frame gives the Love number. Our results agree well with the Newtonian results in the weak field limit. The fully relativistic values differ from the Newtonian values by up to {approx}24%. The Love number is potentially measurable in gravitational wave signals from inspiralling binary neutron stars.

Hinderer, Tanja [Center for Radiophysics and Space Research, Cornell University, Ithaca, NY 14853 (United States)], E-mail: tph25@cornell.edu

2008-04-20

434

Preston Probe Calibrations at High Reynolds Number  

NASA Technical Reports Server (NTRS)

The overall goal of the research effort is to study the performance of two Preston probes designed by NASA Langley Research Center across an unprecedented range of Reynolds number (based on friction velocity and probe diameter), and perform an accurate calibration over the same Reynolds number range. Using the Superpipe facility in Princeton, two rounds of experiments were performed. In each round of experiments for each Reynolds number, the pressure gradient, static pressure from the Preston probes and the total pressure from the Preston probes were measured. In the first round, 3 Preston probes having outer diameters of 0.058 inches, 0.083 inches and 0.203 inches were tested over a large range of pipe Reynolds numbers. Two data reduction methods were employed: first, the static pressure measured on the Preston probe was used to calculate P (modified Preston probe configuration), and secondly, the static pressure measured at the reference pressure tap was used to calculate P (un-modified Preston probe configuration). For both methods, the static pressure was adjusted to correspond with the static pressure at the Preston probe tip using the pressure gradient. The measurements for Preston probes with diameters of 0.058 inches, and 0.083 inches respectively were performed in the test pipe before it was polished a second time. Therefore, the measurements at high pipe Reynolds numbers may have been affected by roughness. In the second round of experiments the 0.058 inches and 0.083 inches diameter, un-modified probes were tested after the pipe was polished and prepared to ensure that the surface was smooth. The average velocity was estimated by assuming that the connection between the centerline velocity and the average velocity was known, and by using a Pitot tube to measure the centerline velocity. A preliminary error estimate suggests that it is possible to introduce a 1% to 2% error in estimating the average velocity using this approach. The evidence on the errors attending the second data set is somewhat circumstantial, and the measurements have not been repeated using a better approach, it seems probable that the correlation given applies to un-modified Preston probes over the range 6.4 less than x* less than 11.3.

Smits, Alexander J.

1998-01-01

435

Algebra, Number Theory and Combinatorics (ANTC) (Program Description)  

NSF Publications Database

... of Mathematical Sciences Algebra, Number Theory and Combinatorics (ANTC) Description Supports ... linear algebra; number theory, including algebraic, analytic number theory, arithmetic geometry ...

436

Insights into the Area Model when Connecting Multiplication with Whole Numbers to Decimal Numbers  

ERIC Educational Resources Information Center

This article describes a valuable lesson that university mathematics faculty members learned from fifth grade and middle school teachers in a professional development workshop. The goal of the workshop was to show how models for whole number operations could be linked to models for rational numbers and to connect the traditional algorithms to the…

Yarema, Connie; Williams, Carol

2004-01-01

437

Piaget, Children, and Number: Applying Piaget's Theory to the Teaching of Elementary Number.  

ERIC Educational Resources Information Center

This paper proposes a method for teaching number applying the conservation theory of Piaget in the classroom. It is suggested that number facts cannot be taught by social transmission, since there is a fundamental distinction between logico-mathematical and social knowledge. Conservation cannot be taught to non-conservers, but there are ways to…

Kamii, Constance; DeVries, Rheta

438

Language and Number Values: The Influence of Number Names on Children's Understanding of Place Value  

ERIC Educational Resources Information Center

In recent years, the idea of language influencing the cognitive development of an understanding of place value has received increasing attention. This study explored the influence of using explicit number names on pre-kindergarten and kindergarten students' ability to rote count, read two-digit numerals, model two-digit numbers, and identify the…

Browning, Sandra T.; Beauford, Judith E.

2012-01-01

439

76 FR 79607 - Local Number Portability Porting Interval and Validation Requirements; Telephone Number Portability  

Federal Register 2010, 2011, 2012, 2013

...when the new service provider requests a CSR: any working telephone number associated...provider requests a Customer Service Record (CSR). Best Practice 70 provides that the transferring...when the new service provider requests a CSR: any working telephone number...

2011-12-22

440

Number Sense and Number Nonsense: Understanding the Challenges of Learning Math  

ERIC Educational Resources Information Center

How do children learn math--and why do some children struggle with it? The answers are in "Number Sense and Number Nonsense," a straightforward, reader-friendly book for education professionals and an invaluable multidisciplinary resource for researchers. More than a first-ever research synthesis, this highly accessible book brings math…

Krasa, Nancy; Shunkwiler, Sara

2009-01-01

441

Cosmological baryon and lepton number in the presence of electroweak fermion-number violation  

NASA Technical Reports Server (NTRS)

In the presence of rapid fermion-number violation due to nonperturbative electroweak effects certain relations between the baryon number of the Universe and the lepton numbers of the Universe are predicted. In some cases the electron-neutrino asymmetry is exactly specified in terms of the baryon asymmetry. Without introducing new particles, beyond the usual quarks and leptons, it is necessary that the Universe possess a nonzero value of B - L prior to the epoch of fermion-number violation if baryon and lepton asymmetries are to survive. Contrary to intuition, even though electroweak processes violate B + L, a nonzero value of B + L persists after the epoch of rapid fermion-number violation. If the standard model is extended to include lepton-number violation, for example through Majorana neutrino masses, then electroweak processes will reduce the baryon number to zero even in the presence of an initial B - L unless 20 M(sub L) approximately greater than the square root of (T(sub B - L) m(sub P1)) where M(sub L) sets the scale of lepton number violation and T(sub B - L) is the temperature at which a B - L asymmetry is produced. In many models this implies that neutrinos must be so light that they cannot contribute appreciably to the mass density of the Universe.

Harvey, Jeffrey A.; Turner, Michael S.

1990-01-01

442

Adaptive Copy Number Evolution in Malaria Parasites  

PubMed Central

Copy number polymorphism (CNP) is ubiquitous in eukaryotic genomes, but the degree to which this reflects the action of positive selection is poorly understood. The first gene in the Plasmodium folate biosynthesis pathway, GTP-cyclohydrolase I (gch1), shows extensive CNP. We provide compelling evidence that gch1 CNP is an adaptive consequence of selection by antifolate drugs, which target enzymes downstream in this pathway. (1) We compared gch1 CNP in parasites from Thailand (strong historical antifolate selection) with those from neighboring Laos (weak antifolate selection). Two percent of chromosomes had amplified copy number in Laos, while 72% carried multiple (2–11) copies in Thailand, and differentiation exceeded that observed at 73 synonymous SNPs. (2) We found five amplicon types containing one to greater than six genes and spanning 1 to >11 kb, consistent with parallel evolution and strong selection for this gene amplification. gch1 was the only gene occurring in all amplicons suggesting that this locus is the target of selection. (3) We observed reduced microsatellite variation and increased linkage disequilibrium (LD) in a 900-kb region flanking gch1 in parasites from Thailand, consistent with rapid recent spread of chromosomes carrying multiple copies of gch1. (4) We found that parasites bearing dhfr-164L, which causes high-level resistance to antifolate drugs, carry significantly (p?=?0.00003) higher copy numbers of gch1 than parasites bearing 164I, indicating functional association between genes located on different chromosomes but linked in the same biochemical pathway. These results demonstrate that CNP at gch1 is adaptive and the associations with dhfr-164L strongly suggest a compensatory function. More generally, these data demonstrate how selection affects multiple enzymes in a single biochemical pathway, and suggest that investigation of structural variation may provide a fast-track to locating genes underlying adaptation.

Nair, Shalini; Miller, Becky; Barends, Marion; Jaidee, Anchalee; Patel, Jigar; Mayxay, Mayfong; Newton, Paul; Nosten, Francois; Ferdig, Michael T.; Anderson, Tim J. C.

2008-01-01

443

Generating high Reynolds-number flows.  

NASA Technical Reports Server (NTRS)

Present test facilities are seriously limited regarding investigations involving high Reynolds numbers due to financial considerations. Quasi-steady testing facilities offer a practical immediate solution to the problem of high-Re testing. A familiar example is the blowdown wind tunnel, but even more flexibility and economy may be provided by using shock-tube devices. The Ludwieg tube is the shock-tube device most often proposed as a means of generating high-Re flows. Two-stage nozzles may be used with a Ludwieg tube. Quasi-steady facilities will be useful only if the available test time exceeds that required to establish steady flow.

Russell, D. A.

1972-01-01

444

K.CC Rainbow Number Line  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: The teacher will need a package of regular sentence strips and a medium point black permanent marker. Write the numbers from 1-20 on a sentence strip, ...

445

Index to Plant Chromosome Numbers (IPCN)  

NSDL National Science Digital Library

The Missouri Botanical Garden (MOBOT), with funding from the National Science Foundation, publishes biennially the Index to Plant Chromosome Numbers (IPCN), containing information (gleaned from the scientific literature) on original chromosome counts of naturally occurring and cultivated plants. The online Index currently covers the years 1994-1995, with a new Index for 1996-1997 soon to be released. The searchable IPCN represents taxa from the Bryophytes through Zygophyllaceae, and provides gametophytic and sporophytic counts as well as IPCN volume and reference information.

446

Health Code Number (HCN) Development Procedure  

SciTech Connect

This report provides the detailed description of health code numbers (HCNs) and the procedure of how each HCN is assigned. It contains many guidelines and rationales of HCNs. HCNs are used in the chemical mixture methodology (CMM), a method recommended by the department of energy (DOE) for assessing health effects as a result of exposures to airborne aerosols in an emergency. The procedure is a useful tool for proficient HCN code developers. Intense training and quality assurance with qualified HCN developers are required before an individual comprehends the procedure to develop HCNs for DOE.

Petrocchi, Rocky; Craig, Douglas K.; Bond, Jayne-Anne; Trott, Donna M.; Yu, Xiao-Ying

2013-09-01

447

It's the skill mix not the numbers.  

PubMed

IN THE February issue of Nursing Management, chief nurse at Guy's and St Thomas' NHS Foundation Trust, London, Eileen Sills is reported as expressing fears that having staffing levels posted at ward entrances heightens patients' anxiety. Her concerns raise a number of issues. Anxiety about displaying nurse-to-patient ratios (NPRs) on the ward reminds me of similar discussions in the past about whether patients and their relatives should be told if they had cancer. Sometimes relatives were told, but not the patients, because 'they would not be able to cope'. PMID:24870434

Hunt, Jennifer

2014-05-01

448

Truly random number generation: an example  

NASA Astrophysics Data System (ADS)

Randomness is crucial for a variety of applications, ranging from gambling to computer simulations, and from cryptography to statistics. However, many of the currently used methods for generating randomness do not meet the criteria that are necessary for these applications to work properly and safely. A common problem is that a sequence of numbers may look random but nevertheless not be truly random. In fact, the sequence may pass all standard statistical tests and yet be perfectly predictable. This renders it useless for many applications. For example, in cryptography, the predictability of a "andomly" chosen password is obviously undesirable. Here, we review a recently developed approach to generating true | and hence unpredictable | randomness.

Frauchiger, Daniela; Renner, Renato

2013-10-01

449

Investigations in Number, Data, and Space  

NSDL National Science Digital Library

Investigations is a complete K-5 mathematics curriculum, developed at TERC in Cambridge, Mass. It is designed to help all children understand the fundamental ideas of number and operations, geometry, data, measurement, and early algebra. The curriculum has four major goals: to offer students meaningful mathematical problems; emphasize depth in mathematical thinking; communicate mathematics content and pedagogy to teachers; and expand the pool of mathematically literate students. This site includes descriptions of the units in each grade, K through 5; ordering information; and information on professional-development workshops designed to facilitate introduction of this curriculum.

Terc

450

Risk communication: Uncertainties and the numbers game  

SciTech Connect

The science of risk assessment seeks to characterize the potential risk in situations that may pose hazards to human health or the environment. However, the conclusions reached by the scientists and engineers are not an end in themselves - they are passed on to the involved companies, government agencies, legislators, and the public. All interested parties must then decide what to do with the information. Risk communication is a type of technical communication that involves some unique challenges. This paper first defines the relationships between risk assessment, risk management, and risk communication and then explores two issues in risk communication: addressing uncertainty and putting risk number into perspective.

Ortigara, M. [ed.

1995-08-30

451

A recursion equation for prime numbers  

Microsoft Academic Search

It is shown that the first $n$ prime numbers $p_1,...,p_n$ determine the next\\u000aone by the recursion equation $$ p_{n+1} =\\\\lim\\\\limits_{s\\\\to +\\\\infty}\\u000a[\\\\prod\\\\limits^n_{k=1} (1-\\\\frac{1}{p^s_k}) \\\\sum\\\\limits^\\\\infty_{j=1}\\u000a\\\\frac{1}{j^s} -1]^{-1\\/s}. $$ The upper limit on the sum can be replaced by\\u000a$2p_n -1$, and the result still holds.

Joseph B. Keller

2007-01-01

452

32 CFR 635.21 - USACRC control numbers.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false USACRC control numbers. 635.21 Section 635...Reporting § 635.21 USACRC control numbers. (a) Case numbers to...reporting criminal incidents, USACRC control numbers will be used only one time...

2013-07-01

453

20 CFR 422.103 - Social security numbers.  

Code of Federal Regulations, 2010 CFR

...the immigration process, that SSA assign a social security number and issue a social security number card to him/her. Requests...SSA's central office assigns a number and issues a social security number card. If investigation...

2009-04-01

454

20 CFR 422.103 - Social security numbers.  

Code of Federal Regulations, 2010 CFR

...the immigration process, that SSA assign a social security number and issue a social security number card to him/her. Requests...SSA's central office assigns a number and issues a social security number card. If investigation...

2010-04-01

455

Four-Digit Numbers Which Are Squared Sums  

ERIC Educational Resources Information Center

There is a very natural way to divide a four-digit number into 2 two-digit numbers. Applying an algorithm to this pair of numbers, determine how often the original four-digit number reappears. (Contains 3 tables.)

Coughlin, Heather; Jue, Brian

2009-01-01

456

47 CFR 52.20 - Thousands-block number pooling.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Thousands-block number pooling. 52.20 Section 52.20 Telecommunication...CARRIER SERVICES (CONTINUED) NUMBERING Number Portability § 52.20 Thousands-block number pooling. (a) Definition....

2010-10-01

457

Mach number dependence of electron heating at high Mach number interplanetary shocks in the inner heliospere  

NASA Astrophysics Data System (ADS)

In the inner heliosphere a variety of interplanetary shocks with different Mach numbers are expected to be present. A possible maximum Mach number at 0.3AU from the sun is esti-mated to be about 40. Efficiency of electron heating in such high Mach number shocks is one of the outstanding issues of space plasma physics as well as astrophysics. Here, from this aspect, electron heating rate through microinstabilities generated in the transition region of a quasi-perpendicular shock for wide range of Mach numbers is investigated. Saturation levels of effective electron temperature as a result of modified two-stream instability (MTSI) are es-timated by using a semianalytic approach which we call an extended quasilinear analysis here. The results are compared with one-dimensional full particle-in-cell simulations. It is revealed that Mach number dependence of the effective electron temperature is weak when a Mach num-ber is below a certain critical value. Above the critical value, electron temperature increases being proportional to an upstream flow energy because of that a dominant microinstability in the foot changes from the MTSI to Buneman instability. The critical Mach number is roughly estimated to be a few tens.

Matsukiyo, Shuichi

458

Estimating the Number of Buildings in Germany  

NASA Astrophysics Data System (ADS)

The debate on sustainable development has lead to the view of buildings as flows (mass, energy, money and information) or capitals. In this context buildings are considered as the largest physical, economical, social and cultural capital of a society. In Germany many institutions record different kind of data about buildings. Unfortunately there are just a few basic statistics about the amount of buildings. Collection of data is very complicated, often expensive and the handling of missing data is one of the biggest handicaps. With the exception of data about residential buildings and particularly monuments, it is an unsolved problem to determine the total number of buildings. Thus the main issue of this article is the description of an appropriate estimation procedure. This procedure relies on 12,430 communes and refers to data from the Cadaster of Real Estates and the Federal Office for Building and Regional Planning (BBR). The estimation is based on statistical data from well-known and easily accessible institutions. The number of buildings is estimated for communes with missing data. Using methods from the, so called, Urban Data Mining approach, unsuspected relationships are found in the urban data. These relationships are valuable for the estimation. The quality of the estimation is analyzed by training and test data sets. Information optimization leads to the conclusion that 20% of the communes hold 80% of all buildings. For an improvement of the estimation it is essential to refine the amount and quality of data in the larger communes.

Behnisch, M.; Ultsch, A.

459

Configurable Cellular Automata for Pseudorandom Number Generation  

NASA Astrophysics Data System (ADS)

This paper proposes a generalized structure of cellular automata (CA) — the configurable cellular automata (CoCA). With selected properties from programmable CA (PCA) and controllable CA (CCA), a new approach to cellular automata is developed. In CoCA, the cells are dynamically reconfigured at run-time via a control CA. Reconfiguration of a cell simply means varying the properties of that cell with time. Some examples of properties to be reconfigured are rule selection, boundary condition, and radius. While the objective of this paper is to propose CoCA as a new CA method, the main focus is to design a CoCA that can function as a good pseudorandom number generator (PRNG). As a PRNG, CoCA can be a suitable candidate as it can pass 17 out of 18 Diehard tests with 31 cells. CoCA PRNG's performance based on Diehard test is considered superior over other CA PRNG works. Moreover, CoCA opens new rooms for research not only in the field of random number generation, but in modeling complex systems as well.

Quieta, Marie Therese; Guan, Sheng-Uei

460

Intergenerational resource transfers with random offspring numbers  

PubMed Central

A problem common to biology and economics is the transfer of resources from parents to children. We consider the issue under the assumption that the number of offspring is unknown and can be represented as a random variable. There are 3 basic assumptions. The first assumption is that a given body of resources can be divided into consumption (yielding satisfaction) and transfer to children. The second assumption is that the parents' welfare includes a concern for the welfare of their children; this is recursive in the sense that the children's welfares include concern for their children and so forth. However, the welfare of a child from a given consumption is counted somewhat differently (generally less) than that of the parent (the welfare of a child is “discounted”). The third assumption is that resources transferred may grow (or decline). In economic language, investment, including that in education or nutrition, is productive. Under suitable restrictions, precise formulas for the resulting allocation of resources are found, demonstrating that, depending on the shape of the utility curve, uncertainty regarding the number of offspring may or may not favor increased consumption. The results imply that wealth (stock of resources) will ultimately have a log-normal distribution.

Arrow, Kenneth J.; Levin, Simon A.

2009-01-01

461

Apollo by the Numbers: A Statistical Reference  

NASA Technical Reports Server (NTRS)

The purpose of this work is to provide researchers, students, and space enthusiasts with a comprehensive reference for facts about Project Apollo, America's effort to put humans in the Moon. Research for this work started in 1988, when the author discovered that, despite the number of excellent books that focused on the drama of events that highlighted Apollo, there were none that focused on the drama of the numbers. This book is separated into two parts. The first part contains narratives for the Apollo 1 fire and the 11 flown Apollo missions. Included after each narrative is a series of data tables, followed by a comprehensive timeline of events from just before liftoff to just after crew and spacecraft recovery. The second part contains more than 50 tables. These tables organize much of the data from the narratives in one place so they can be compared among all missions. The tables offer additional data as well. The reader can select a specific mission narrative or specific data table by consulting the Table of Contents.

Orloff, Richard; Garber, Stephen (Technical Monitor)

2000-01-01

462

Synchronization of Sunspot Numbers and Sunspot Areas  

NASA Astrophysics Data System (ADS)

Sunspot activity is usually described by either sunspot numbers or sunspot areas. The smoothed monthly mean sunspot numbers (SNs) and the smoothed monthly mean areas (SAs) in the time interval from November 1874 to September 2007 are used to analyze their phase synchronization. Both the linear method (fast Fourier transform) and some nonlinear approaches (continuous wavelet transform, cross-wavelet transform, wavelet coherence, cross-recurrence plot, and line of synchronization) are utilized to show the phase relation between the two series. There is a high level of phase synchronization between SNs and SAs, but the phase synchronization is detected only in their low-frequency components, corresponding to time scales of about 7 to 12 years. Their high-frequency components show a noisy behavior with strong phase mixing. Coherent phase variables should exist only for a frequency band with periodicities around the dominating 11-year cycle for SNs and SAs. There are some small phase differences between them. SNs lag SAs during most of the considered time interval, and they are in general more asynchronous around the minimum and maximum times of a cycle than at the ascending and descending phases.

Li, K. J.; Gao, P. X.; Zhan, L. S.

2009-04-01

463

Emergence, Self-Organization and Prime Numbers  

NASA Astrophysics Data System (ADS)

Pattern of primes (PP) is critical for dynamics of universal emergence, self-organization and complexity ascendance [1-3]. Due to gradual logarithmic dilution of primes (prime number theorem), PP gives only base envelop for above effects. More informative are full factorizational spectra (FS) of all intermediate composites. Tower exponential mappings like f(N) = 10(N)10 with (N) indicating N vertical arrows [4] lead to infinite fractal-like hierarchy of integer trails; say, FS of intervals between f(N) and f(N+1). This allows FAPP-infinite informational content of PP and FS be "used" as catalyzer of emergence dynamics. This is "Platonic pressure effect" (physical embodiments of PP and FS). Said effect may provide more direct picture for cosmogenesis than traditional quantum tunneling ("Big Bang") and/or inflationary scenarios. Furthermore, we can speculate that metrics of (Mega)universe at tower exponential scales becomes asymptotically Euclidean (multi or infinitely dimensional), due to unchangability of PP and FS. - [1] Arnold Arnold, "The Corrupted Sciences", Paladin (Harper Collins), 1992; [2] Peter Plichta, "God's Secret Formula: Deciphering the Riddle of the Universe and the Prime Number Code", Element, 1997; [3] Alexander Berezin, URAM Journal, 20, 72 (1997); [4] Donald E. Knuth, Science, 194, 1235, 17 Dec 1976. abstract.

Berezin, Alexander A.

1998-04-01

464

Natural occupation numbers: When do they vanish?  

NASA Astrophysics Data System (ADS)

The non-vanishing of the natural orbital (NO) occupation numbers of the one-particle density matrix of many-body systems has important consequences for the existence of a density matrix-potential mapping for nonlocal potentials in reduced density matrix functional theory and for the validity of the extended Koopmans' theorem. On the basis of Weyl's theorem we give a connection between the differentiability properties of the ground state wavefunction and the rate at which the natural occupations approach zero when ordered as a descending series. We show, in particular, that the presence of a Coulomb cusp in the wavefunction leads, in general, to a power law decay of the natural occupations, whereas infinitely differentiable wavefunctions typically have natural occupations that decay exponentially. We analyze for a number of explicit examples of two-particle systems that in case the wavefunction is non-analytic at its spatial diagonal (for instance, due to the presence of a Coulomb cusp) the natural orbital occupations are non-vanishing. We further derive a more general criterium for the non-vanishing of NO occupations for two-particle wavefunctions with a certain separability structure. On the basis of this criterium we show that for a two-particle system of harmonically confined electrons with a Coulombic interaction (the so-called Hookium) the natural orbital occupations never vanish.

Giesbertz, K. J. H.; van Leeuwen, R.

2013-09-01

465

Binary droplet collision at high Weber number.  

PubMed

By using the techniques developed for generating high-speed droplets, we have systematically investigated binary droplet collision when the Weber number (We) was increased from the range usually tested in previous studies on the order of 10 to a much larger value of about 5100 for water (a droplet at 23 m/s with a diameter of 0.7 mm). Various liquids were also used to explore the effects of viscosity and surface tension. Specifically, beyond the well-known regimes at moderate We's, which exhibited coalescence, separation, and separation followed by satellite droplets, we found different behaviors showing a fingering lamella, separation after fingering, breakup of outer fingers, and prompt splattering into multiple secondary droplets as We was increased. The critical Weber numbers that mark the boundaries between these impact regimes are identified. The specific impact behaviors, such as fingering and prompt splattering or splashing, share essential similarity with those also observed in droplet-surface impacts, whereas substantial variations in the transition boundaries may result from the disparity of the boundary conditions at impacts. To compare the outcomes of both types of collisions, a simple model based on energy conservation was carried out to predict the maximum diameter of an expanding liquid disk for a binary droplet collision. The results oppose the dominance of viscous drag, as proposed by previous studies, as the main deceleration force to effect a Rayleigh-Taylor instability and ensuing periphery fingers, which may further lead to the formations of satellite droplets. PMID:19905206

Pan, Kuo-Long; Chou, Ping-Chung; Tseng, Yu-Jen

2009-09-01

466

Modeling microscopic swimmers at low Reynolds number  

NASA Astrophysics Data System (ADS)

The authors employ three numerical methods to explore the motion of low Reynolds number swimmers, modeling the hydrodynamic interactions by means of the Oseen tensor approximation, lattice Boltzmann simulations, and multiparticle collision dynamics. By applying the methods to a three bead linear swimmer, for which exact results are known, the authors are able to compare and assess the effectiveness of the different approaches. They then propose a new class of low Reynolds number swimmers, generalized three bead swimmers that can change both the length of their arms and the angle between them. Hence they suggest a design for a microstructure capable of moving in three dimensions. They discuss multiple bead, linear microstructures and show that they are highly efficient swimmers. They then turn to consider the swimming motion of elastic filaments. Using multiparticle collision dynamics the authors show that a driven filament behaves in a qualitatively similar way to the micron-scale swimming device recently demonstrated by Dreyfus et al. [Nature (London) 437, 862 (2005)].

Earl, David J.; Pooley, C. M.; Ryder, J. F.; Bredberg, Irene; Yeomans, J. M.

2007-02-01

467

Functional Copy-Number Alterations in Cancer  

PubMed Central

Understanding the molecular basis of cancer requires characterization of its genetic defects. DNA microarray technologies can provide detailed raw data about chromosomal aberrations in tumor samples. Computational analysis is needed (1) to deduce from raw array data actual amplification or deletion events for chromosomal fragments and (2) to distinguish causal chromosomal alterations from functionally neutral ones. We present a comprehensive computational approach, RAE, designed to robustly map chromosomal alterations in tumor samples and assess their functional importance in cancer. To demonstrate the methodology, we experimentally profile copy number changes in a clinically aggressive subtype of soft-tissue sarcoma, pleomorphic liposarcoma, and computationally derive a portrait of candidate oncogenic alterations and their target genes. Many affected genes are known to be involved in sarcomagenesis; others are novel, including mediators of adipocyte differentiation, and may include valuable therapeutic targets. Taken together, we present a statistically robust methodology applicable to high-resolution genomic data to assess the extent and function of copy-number alterations in cancer.

Taylor, Barry S.; Barretina, Jordi; Socci, Nicholas D.; DeCarolis, Penelope; Ladanyi, Marc; Meyerson, Matthew; Singer, Samuel; Sander, Chris

2008-01-01

468

The transfer number of hydrocarbon liquids  

SciTech Connect

This paper discusses the transfer number (B) which assumes considerable importance in the evaporation and diffusion of fuels prior to their combustion. Quite often the transfer number is assumed to be a constant for a given fuel. These notes examine the feasibility of this assumption. New correlations have been derived for the specific heats of the liquid fuels and their latent heats, over a wide range of temperatures and pressures, as also the effects of pressure upon the boiling characteristics. New prediction techniques are also proposed for critical temperatures and pressures. Taking note of the above correlations, it becomes possible to assess the values of B for a wide range of combustor operating conditions for any given fuel. The significance of these variations upon the probable combustion behavior of the fuels is then commented upon. The results show that the assumption of a constant value for B could lead to a significant misinterpretation of combustion behavior due to operating conditions and/or the use of different fuels.

Odgers, J.; Kretschmer, D. (Dept. of Mechanical Engineering, Laval Univ., Quebec City, Quebec G1K 7P4 (CA))

1992-04-01

469

Quantity without numbers and numbers without quantity in the parietal cortex  

PubMed Central

A dominant view in numerical cognition is that processing the quantity indicated by numbers (e.g. deciding the larger between two numbers such as ‘12.07’ or ‘15.02’) relies on the intraparietal regions (IPS) of the cerebral cortex. However, it remains unclear whether the IPS could play a more general role in numerical cognition, for example in (1) quantity processing even with non-numerical stimuli (e.g. choosing the larger of ‘bikini’ and ‘coat’); and/or (2) conceptual tasks involving numbers beyond those requiring quantity processing (e.g. attributing a summer date to either ‘12.07’ or ‘15.02’). In this study we applied fMRI-guided TMS to the left and right IPS, while independently manipulating stimulus and task. Our results showed that IPS involvement in numerical cognition is neither stimulus-specific nor specific for conceptual tasks. Thus, quantity judgments with numerical and non-numerical stimuli were equally affected by IPS-TMS, as well as a number conceptual task not requiring quantity comparisons. However, IPS-TMS showed no impairment for perceptual decisions on numbers without any conceptual processing (i.e. colour judgment), nor for conceptual decisions that did not involve quantity or number stimuli (e.g. summer object: ‘bikini’ or ‘coat’?). These results are consistent with proposals that the parietal areas are engaged in the conceptual representation of numbers but they challenge the most common view that number processing is so automatic that the simple presentation of numbers activates the IPS and a sense of magnitude. Rather, our results show that the IPS is only necessary when conceptual operations need to be explicitly oriented to numerical concepts.

Cappelletti, Marinella; Muggleton, Neil; Walsh, Vincent

2009-01-01

470

Quantity without numbers and numbers without quantity in the parietal cortex.  

PubMed

A dominant view in numerical cognition is that processing the quantity indicated by numbers (e.g. deciding the larger between two numbers such as '12.07' or '15.02') relies on the intraparietal regions (IPS) of the cerebral cortex. However, it remains unclear whether the IPS could play a more general role in numerical cognition, for example in (1) quantity processing even with non-numerical stimuli (e.g. choosing the larger of 'bikini' and 'coat'); and/or (2) conceptual tasks involving numbers beyond those requiring quantity processing (e.g. attributing a summer date to either '12.07' or '15.02'). In this study we applied fMRI-guided TMS to the left and right IPS, while independently manipulating stimulus and task. Our results showed that IPS involvement in numerical cognition is neither stimulus-specific nor specific for conceptual tasks. Thus, quantity judgments with numerical and non-numerical stimuli were equally affected by IPS-TMS, as well as a number conceptual task not requiring quantity comparisons. However, IPS-TMS showed no impairment for perceptual decisions on numbers without any conceptual processing (i.e. colour judgment), nor for conceptual decisions that did not involve quantity or number stimuli (e.g. summer object: 'bikini' or 'coat'?). These results are consistent with proposals that the parietal areas are engaged in the conceptual representation of numbers but they challenge the most common view that number processing is so automatic that the simple presentation of numbers activates the IPS and a sense of magnitude. Rather, our results show that the IPS is only necessary when conceptual operations need to be explicitly oriented to numerical concepts. PMID:19236924

Cappelletti, Marinella; Muggleton, Neil; Walsh, Vincent

2009-06-01

471

Explicit and probabilistic constructions of distance graphs with small clique numbers and large chromatic numbers  

NASA Astrophysics Data System (ADS)

We study distance graphs with exponentially large chromatic numbers and without k-cliques, that is, complete subgraphs of size k. Explicit constructions of such graphs use vectors in the integer lattice. For a large class of graphs we find a sharp threshold for containing a k-clique. This enables us to improve the lower bounds for the maximum of the chromatic numbers of such graphs. We give a new probabilistic approach to the construction of distance graphs without k-cliques, and this yields better lower bounds for the maximum of the chromatic numbers for large k.

Kupavskii, A. B.

2014-02-01

472

Inventing Numbers: How Mathematicians Filled the Inky Void.  

ERIC Educational Resources Information Center

Describes the development of numbers, discussing natural and rational numbers; geometry (inscribing numbers on the number line); smoothness of motion reflected in the geometrical line; square roots; and irrational numbers. Concludes that whatever the ultimate identity of irrational numbers, what is known about them is less important than what is…

Berlinski, David

2002-01-01

473

Non-perfect square roots as rational numbers  

NSDL National Science Digital Library

Understanding Irrational numbers that can be written as rational numbers can assist students and their understanding of the real number system. Irrational numbers can be approximated as rational numbers but not written as rational numbers. This lesson provides practice in these ideas.

Whalen, Dennis

2012-09-13

474

Strategic use of number representation is independent of test instruction in random number generation.  

PubMed

The effects of different instructions on verbal random number generation were examined in 40 healthy students who attempted to generate random sequences of the digits 1 to 6. Two groups of 20 received different instructions with alternative numerical representations. The Symbolic group (Arabic digits) was instructed to randomize while continuously using the analogy of selecting and replacing numbered balls from a hat, whereas the Nonsymbolic group (arrays of dots) was instructed to imagine repeatedly throwing a die. Participants asked for self-reports on their strategies reported spontaneously occurring visuospatial imagination of a mental number line (42%), or imagining throwing a die (23%). Individual number representation was not affected by the initial instruction. There were no differences in randomization performance by group. Comprehensive understanding of the nature of the randomization task requires considering individual differences in construction of mental models. PMID:20499555

Strenge, Hans; Rogge, Carolin

2010-04-01

475

Exact solution of the unsteady natural convective radiating gas flow in a vertical channel  

NASA Astrophysics Data System (ADS)

An exact solution is presented for the problem of unsteady natural convective radiating flow in an open-ended vertical channel. Laplace transform technique is used to obtain the analytical solutions for the velocity and temperature fields in the optically thin limit case when the channel walls temperature are maintained at different constant temperatures. The effects of radiation parameter and Grashof number on the flow fields are discussed through graphs. It is found that the effect of radiation is to decrease the fluid velocity whereas the effect of Grashof number is to increase the fluid velocity in the vertical channel.

Narahari, M.; Pendyala, Rajashekhar

2013-09-01

476

Second Law Analysis in Convective Heat and Mass Transfer  

NASA Astrophysics Data System (ADS)

This paper reports the numerical determination of the entropy generation due to heat transfer, mass transfer and fluid friction in steady state for laminar double diffusive convection, in an inclined enclosure with heat and mass diffusive walls, by solving numerically the mass, momentum, species conservation and energy balance equations, using a Control Volume Finite-Element Method. The influences of the inclination angle, the thermal Grashof number and the buoyancy ratio on total entropy generation were investigated. The irreversibilities localization due to heat transfer, mass transfer and fluid friction is discussed for three inclination angles at a fixed thermal Grashof number.

Magherbi, M.; Abbassi, H.; Hidouri, N.; Brahim, A. B.

2006-03-01

477

Nanotubes: number of Kekulé structures and aromaticity.  

PubMed

Carbon nanotubes (CNTs) are composed of cylindrical graphite sheets consisting of sp(2) carbons. Due to their structure CNTs are considered to be aromatic systems. In this work the number of Kekulé structures (K) in "armchair" CNTs was estimated by using the transfer matrix technique. All Kekulé structures of the cyclic variants of naphthalene and benzo[c]phenanthrene have been generated and the basic patterns have been obtained. From this information the elements of the transfer matrix were derived. The results obtained indicate that K (and the resonance energy) is greater if tubulenes are extended in the vertical than in the horizontal direction. Tubulenes are therefore more stabile than cyclic strips. An illustration, obtained by using scanning probe microscope, has been attached to affirm the existence of thin CNTs. PMID:12653528

Lukovits, István; Graovac, Ante; Kálmán, Erika; Kaptay, György; Nagy, Péter; Nikoli?, Sonja; Sytchev, Jaroslav; Trinajsti?, Nenad

2003-01-01

478

Number of representations providing noiseless subsystems  

SciTech Connect

This paper studies the combinatoric structure of the set of all representations, up to equivalence, of a finite-dimensional semisimple Lie algebra. This has intrinsic interest as a previously unsolved problem in representation theory, and also has applications to the understanding of quantum decoherence. We prove that for Hilbert spaces of sufficiently high dimension, decoherence-free (DF) subspaces exist for almost all representations of the error algebra. For decoherence-free subsystems, we plot the function f{sub d}(n) which is the fraction of all d-dimensional quantum systems which preserve n bits of information through DF subsystems, and note that this function fits an inverse beta distribution. The mathematical tools which arise include techniques from classical number theory.

Ritter, William Gordon [Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138 (United States)

2005-12-15

479

Photon number squeezed states in semiconductor lasers  

NASA Technical Reports Server (NTRS)

Electromagnetic fields, with the noise on one quadrature component reduced to below the quantum mechanical zero-point fluctuation level and the noise on the other quadrature component enhanced to above it, are currently of great interest in quantum optics because of their potential applications to various precision measurements. Such squeezed states of light are usually produced by imposing nonlinear unitary evolution on coherent (or vacuum) states. On the other hand, squeezed states with reduced photon number noise and enhanced phase noise are generated directly by a constant current-driven semiconductor laser. This is the simplest scheme for the generation of nonclassical light, and so far it has yielded the largest quantum noise reduction. The mutual coupling between a lasing junction and an external electrical circuit provides opportunities for exploring the macroscopic and microscopic quantum effects in open systems.

Yamamoto, Yoshihisa; Machida, Susumu; Richardson, Wayne H.

1992-01-01

480

Mechanisms of change in gene copy number  

PubMed Central

Deletions and duplications of chromosomal segments (copy-number variations or CNVs) constitute a major source of variation between individual humans, underlying human evolution and many diseases from mental illness and developmental disorders to cancer. CNVs form at rates far outstripping other kinds of mutagenesis, and appear to do so by similar mechanisms in bacteria, yeast, and human. We review models for the mechanisms of formation of CNVs. Whereas non-homologous end-joining mechanisms are well known, recent models focus on perturbation of DNA replication, and replication of non-contiguous DNA segments, including the proposal that repair of broken replication forks switches under stress from high-fidelity homologous recombinational to nonhomologous repair that promotes CNV.

Hastings, PJ; Lupski, James R; Rosenberg, Susan M; Ira, Grzegorz

2010-01-01

481

Love number can be hard to measure  

NASA Astrophysics Data System (ADS)

The waveform phase for a neutron star binary can be split into point-particle terms and finite-size terms (characterized by the Love number) that account for equation-of-state effects. The latter first enter at fifth post-Newtonian (5PN) order (i.e., proportional to the tenth power of the orbital velocity), but the former are only known completely to 3.5PN order, with higher-order terms only known to leading order in the mass ratio. We here find that not including point-particle terms at 4PN order to leading and first order in the mass ratio in the template model can severely deteriorate our ability to measure the equation of state. This problem can be solved if one uses numerical waveforms once their own systematic errors are under control.

Yagi, Kent; Yunes, Nicolás

2014-01-01

482

Boole: From Calculating Numbers to Calculating Thoughts  

NASA Astrophysics Data System (ADS)

We are often taught in a first course in the history of logic or in the philosophy of mathematics that Frege singlehandedly invented second-order logic, and that there was no one close to his achievements before him. In a slightly more sophisticated version of the same course, a qualifying nod is made in the direction of Boole, who did "bring quantifiers to logic". But the student is given the impression that Boole, like Frege, rose ex nihilo from the weedy wasteland of Aristotelian syllogistic reasoning. While this is not a wholly mistaken impression, it is misleading, and should be corrected. Boole was working in the context of a revival of logic - where "logic", especially as it was being taught in England, was gradually being prised away from the doxa of Aristotelian syllogistic reasoning. It is in this context that Boole made innovative contributions by bringing together a number of ideas. The combination brought us closer to our modern conception of logic.

Friend, Michèle

483

Design of low Reynolds number airfoils. II  

NASA Technical Reports Server (NTRS)

Low Reynolds number airfoils were designed for high lift-to-drag ratios. Design considerations of low Re-airfoils are discussed and design examples are presented. It is shown that the performance of advance low Reynolds airfoils critically depends on proper laminar separation and transition control for the minimum profile drag coefficient with minimum turbulator device drag. This transition control close to the laminar separation is possible by enforcing transition on the upper surface either directly by means of spanwise rows of three-dimensional roughness elements, bleed or suction holes, or indirectly by means of destabilizing the upper surface boundary layer by means of backward facing surface steps, two-dimensional or zig-zag tapes or weak boundary layer blowing. Pneumatic turbulators are found to be advantageous because they can be adjusted to different external flow conditions better than mechanical ones.

Pfenninger, W.; Vemuru, C. S.; Mangalam, S.; Evangelista, R.

1988-01-01

484

Copy number variation in the cattle genome.  

PubMed

Copy number variations (CNVs) are gains and losses of genomic sequence greater than 50 bp between two individuals of a species. While single nucleotide polymorphisms (SNPs) are more frequent, CNVs impact a higher percentage of genomic sequence and have potentially greater effects, including the changing of gene structure and dosage, altering gene regulation and exposing recessive alleles. In particular, segmental duplications (SDs) were shown to be one of the catalysts and hotspots for CNV formation. Substantial progress has been made in understanding CNVs in mammals, especially in humans and rodents. CNVs have been shown to be important in both normal phenotypic variability and disease susceptibility. Recently, interest in CNV study has extended into domesticated animals, including cattle. Multiple genome-wide cattle CNV studies have been carried out using both microarray and next generation sequencing technologies. Integration of SD and CNV results with SNP and other datasets are beginning to reveal impacts of CNVs on cattle domestication, health, and production traits. PMID:22790923

Liu, George E; Bickhart, Derek M

2012-11-01

485

Number counts and non-Gaussianity  

NASA Astrophysics Data System (ADS)

We describe a general procedure for using number counts of any object to constrain the probability distribution of the primordial fluctuations, allowing for generic weak non-Gaussianity. We apply this procedure to use limits on the abundance of primordial black holes and dark matter ultracompact minihalos to characterize the allowed statistics of primordial fluctuations on very small scales. We present constraints on the power spectrum and the amplitude of the skewness for two different families of non-Gaussian distributions, distinguished by the relative importance of higher moments. Although primordial black holes probe the smallest scales, ultracompact minihalos provide significantly stronger constraints on the power spectrum and so are more likely to eventually provide small-scale constraints on non-Gaussianity.

Shandera, Sarah; Erickcek, Adrienne L.; Scott, Pat; Galarza, Jhon Yana

2013-11-01

486

Stochastic modeling of sunshine number data  

NASA Astrophysics Data System (ADS)

In this paper, we will present a unified statistical modeling framework for estimation and forecasting sunshine number (SSN) data. Sunshine number has been proposed earlier to describe sunshine time series in qualitative terms (Theor Appl Climatol 72 (2002) 127-136) and since then, it was shown to be useful not only for theoretical purposes but also for practical considerations, e.g. those related to the development of photovoltaic energy production. Statistical modeling and prediction of SSN as a binary time series has been challenging problem, however. Our statistical model for SSN time series is based on an underlying stochastic process formulation of Markov chain type. We will show how its transition probabilities can be efficiently estimated within logistic regression framework. In fact, our logistic Markovian model can be relatively easily fitted via maximum likelihood approach. This is optimal in many respects and it also enables us to use formalized statistical inference theory to obtain not only the point estimates of transition probabilities and their functions of interest, but also related uncertainties, as well as to test of various hypotheses of practical interest, etc. It is straightforward to deal with non-homogeneous transition probabilities in this framework. Very importantly from both physical and practical points of view, logistic Markov model class allows us to test hypotheses about how SSN dependents on various external covariates (e.g. elevation angle, solar time, etc.) and about details of the dynamic model (order and functional shape of the Markov kernel, etc.). Therefore, using generalized additive model approach (GAM), we can fit and compare models of various complexity which insist on keeping physical interpretation of the statistical model and its parts. After introducing the Markovian model and general approach for identification of its parameters, we will illustrate its use and performance on high resolution SSN data from the Solar Radiation Monitoring Station of the West University of Timisoara.

Brabec, Marek; Paulescu, Marius; Badescu, Viorel

2013-11-01

487

Long period pseudo random number sequence generator  

NASA Technical Reports Server (NTRS)

A circuit for generating a sequence of pseudo random numbers, (A sub K). There is an exponentiator in GF(2 sup m) for the normal basis representation of elements in a finite field GF(2 sup m) each represented by m binary digits and having two inputs and an output from which the sequence (A sub K). Of pseudo random numbers is taken. One of the two inputs is connected to receive the outputs (E sub K) of maximal length shift register of n stages. There is a switch having a pair of inputs and an output. The switch outputs is connected to the other of the two inputs of the exponentiator. One of the switch inputs is connected for initially receiving a primitive element (A sub O) in GF(2 sup m). Finally, there is a delay circuit having an input and an output. The delay circuit output is connected to the other of the switch inputs and the delay circuit input is connected to the output of the exponentiator. Whereby after the exponentiator initially receives the primitive element (A sub O) in GF(2 sup m) through the switch, the switch can be switched to cause the exponentiator to receive as its input a delayed output A(K-1) from the exponentiator thereby generating (A sub K) continuously at the output of the exponentiator. The exponentiator in GF(2 sup m) is novel and comprises a cyclic-shift circuit; a Massey-Omura multiplier; and, a control logic circuit all operably connected together to perform the function U(sub i) = 92(sup i) (for n(sub i) = 1 or 1 (for n(subi) = 0).

Wang, Charles C. (inventor)

1989-01-01

488

Random number generation in neglect patients reveals enhanced response stereotypy, but no neglect in number space.  

PubMed

Based on interactions between number and space apparent from healthy subjects' randomization attempts we expected random number generation (RNG) to be sensitive for the monitoring of unilateral spatial deficits. Specifically, we predicted patients with left-sided hemineglect to evidence "neglect in number space", i.e. to produce a deficiency in the generation of small, "left-sided" numbers. In RNG of digits from 1 to 6, 19 patients with left-sided neglect generated sequences with a higher redundancy, but as many small numbers as did a matched control group. We discuss possible reasons for the absence of a small-number neglect and emphasize that the observed redundancy was not due to a counting bias, as known from other neurological patients, but to an unspecific imbalance in the use of response alternatives. We speculate that this may be the consequence of disrupted fronto-parietal functions normally serving in the sequential organization and manipulation of items in working memory. PMID:18771676

Loetscher, Tobias; Brugger, Peter

2009-01-01

489

A Generalization of the Formula for the Triangular Number of the Sum and Product of Natural Numbers  

ERIC Educational Resources Information Center

This note generalizes the formula for the triangular number of the sum and product of two natural numbers to similar results for the triangular number of the sum and product of "r" natural numbers. The formula is applied to derive formula for the sum of an odd and an even number of consecutive triangular numbers.

Asiru, M. A.

2008-01-01

490

The relation between spatial skill and early number knowledge: the role of the linear number line.  

PubMed

Spatial skill is highly related to success in math and science (e.g., Casey, Nuttall, Pezaris, & Benbow, 1995). However, little work has investigated the cognitive pathways by which the relation between spatial skill and math achievement emerges. We hypothesized that spatial skill plays a crucial role in the development of numerical reasoning by helping children to create a spatially meaningful, powerful numerical representation-the linear number line. In turn, a strong linear number representation improves other aspects of numerical knowledge such as arithmetic estimation. We tested this hypothesis using 2 longitudinal data sets. First, we found that children's spatial skill (i.e., mental transformation ability) at the beginning of 1st and 2nd grades predicted improvement in linear number line knowledge over the course of the school year. Second, we found that children's spatial skill at age 5 years predicted their performance on an approximate symbolic calculation task at age 8 and that this relation was mediated by children's linear number line knowledge at age 6. The results are consistent with the hypothesis that spatial skill can improve children's development of numerical knowledge by helping them to acquire a linear spatial representation of numbers. PMID:22390659

Gunderson, Elizabeth A; Ramirez, Gerardo; Beilock, Sian L; Levine, Susan C

2012-09-01

491

An exploratory study of a number sense program to develop kindergarten students' number proficiency.  

PubMed

This study examined the effectiveness of a number sense program on kindergarten students' number proficiency and responsiveness to treatment as a function of students' risk for mathematics difficulties. The program targeted development of relationships among numbers (e.g., spatial, more and less). A total of 101 kindergarten students (not at risk: 22 control and 36 experimental; at risk: 18 and 25) from five classrooms in a high-poverty elementary school participated in the study. Using a quasi-experimental design, classrooms were randomly assigned to either the intervention (number sense instruction, NSI) or control condition. Results indicated significant differences favoring the treatment students on all measures of number sense (e.g., spatial relationships, more and less relationships, benchmarks of five and ten, nonverbal calculations) at posttest and on a 3-week retention test. Furthermore, the effects were not mediated by at-risk status, suggesting that NSI may benefit a wide range of students. Implications in terms of preventing early mathematical learning difficulties are discussed. PMID:22043026

Sood, Sheetal; Jitendra, Asha K

2013-01-01

492

Molecular simulation of small Knudsen number flows  

NASA Astrophysics Data System (ADS)

The direct simulation Monte Carlo (DSMC) method is a powerful particle-based method for modeling gas flows. It works well for relatively large Knudsen (Kn) numbers, typically larger than 0.01, but quickly becomes computationally intensive as Kn decreases due to its time step and cell size limitations. An alternative approach was proposed to relax or remove these limitations, based on replacing pairwise collisions with a stochastic model corresponding to the Fokker-Planck equation [J. Comput. Phys., 229, 1077 (2010); J. Fluid Mech., 680, 574 (2011)]. Similar to the DSMC method, the downside of that approach suffers from computationally statistical noise. To solve the problem, a diffusion-based information preservation (D-IP) method has been developed. The main idea is to track the motion of a simulated molecule from the diffusive standpoint, and obtain the flow velocity and temperature through sampling and averaging the IP quantities. To validate the idea and the corresponding model, several benchmark problems with Kn ~ 10-3-10-4 have been investigated. It is shown that the IP calculations are not only accurate, but also efficient because they make possible using a time step and cell size over an order of magnitude larger than the mean collision time and mean free path, respectively.

Fei, Fei; Fan, Jing

2012-11-01

493

Neighborhood consistency and memory for number facts.  

PubMed

Verguts and Fias (Memory & Cognition 33:1-16, 2005a) proposed a new model of memory for simple multiplication facts (2 x 3 = 6; 8 x 7 =56) in which learning and performance is governed by the consistency of a problem's correct product with neighboring products in the times table. In the present study, to directly investigate effects of neighborhood consistency, participants memorized a set of 16 novel "pound" arithmetic equations. The pound arithmetic table included eight tie equations with repeated operands (e.g., 4 # 4 = 29) and eight nontie equations (e.g., 5 # 4 = 39). In the consistent problem set, tie and nontie answers in adjacent columns and rows shared a common decade or unit value. In the inconsistent problem set, neighboring tie and nontie problems did not share a common decade or unit. Across 14 study-test blocks, memorization of the pound arithmetic table presented a robust effect of neighborhood consistency, with the rate of learning nearly doubling that of the inconsistent condition. An analysis of error types showed that consistency fostered the development of a categorical structure based on problem operands and that tie problems were encoded as a distinct subcategory of problems. There was also a substantial learning advantage for tie problems relative to nonties both with consistent and inconsistent neighbors. The results indicate that neighborhood consistency can have a major impact on memory for number facts. PMID:21264638

Campbell, Jamie I D; Dowd, Roxanne R; Frick, Jillian M; McCallum, Kendra N; Metcalfe, Arron W S

2011-07-01

494

Matching residency numbers to the workforce needs.  

PubMed

Matching the number of surgeons to the demands for orthopedic services has been notoriously difficult. Not only does one need to evaluate current trends in the supply and provision of services but anticipate the impact of future reforms on these variables. The British Orthopaedic Association has aspired to provide consultant to population ratio of 1:15,000 by 2020. Currently, the orthopedic community is tasked with providing care for an aging population with soaring levels of obesity; with both of these factors set to grow and also with an overall decline in productivity. Orthopedic surgeons must brace themselves for an explosion in demand. At the same time, a paradigm shift has occurred in the delivery of services with the creation of specialist centers. We are amidst a generational shift in the demographics and psychology of the orthopedic workforce. The orthopedic community must be aware of the effects of these far-reaching changes when tailoring the supply of surgeons for the future needs. PMID:24706153

Khan, S; Johnston, L; Faimali, M; Gikas, P; Briggs, T W

2014-06-01

495

Leptogenesis with an almost conserved lepton number  

SciTech Connect

Seesaw models with a slightly broken lepton number symmetry can explain small neutrino masses, and allow for low-scale leptogenesis. We make a thorough analysis of leptogenesis within the simplest model with two right-handed (RH) neutrinos (or with N{sub 3} decoupled). We obtain a semianalytical formula for the final asymmetry in both supersymmetric and nonsupersymmetric cases with a simple dependence on each parameter. The low-energy parameters factorize from the high-energy ones, and the high-energy phase must be nonzero. The role of the low-energy phases is carefully studied. Moreover, we find that the breaking parameter in the Yukawa coupling matrix must be relatively large, {epsilon}{sub h} > or approx. 10{sup -3} for normal and 10{sup -2} for inverted hierarchy. Therefore, leptogenesis in our simple model is incompatible with RH neutrino signals at future colliders or sizable lepton-flavor violation. The other breaking parameter, {epsilon}{sub M}, which appears in the RH neutrino mass matrix, can be much smaller, and actually needs to be so in order to have low-scale leptogenesis.

Asaka, Takehiko [Department of Physics, Niigata University, 950-2181 Niigata (Japan); Blanchet, Steve [Maryland Center for Fundamental Physics, University of Maryland, College Park, Maryland 20742 (United States)

2008-12-15

496

[Forecasting octane numbers of gasoline by NIR spectroscopy and the manufacture of octane number analyzer].  

PubMed

The predictive model of octane numbers, of gasoline was developed by using MLR and PLS method of chemometrics. It is applicable to forecast the MON, RON and PON of gasoline of catalytic cracking, catalytic reforming, alkylating as well as blended products. A near infrared optical multichannel analyzer (NIR-OMA) and a software package of octane number were developed. Combining both mentioned above a NIR-OM octane number analyzer was developed. With this NIR-OMONA one can obtain the MON, RON and PON (antiknock index) data in less than 1/2 minute with an accuracy of 0.6 ON unit and a precision of 0.1 ON unit by using 3-15 mL gasoline sample. PMID:15822266

Wang, Z; Hua, W; Wei, Z; Zhang, H; Wu, H

1999-10-01

497

Role of Turbulent Prandtl Number on Heat Flux at Hypersonic Mach Numbers  

NASA Technical Reports Server (NTRS)

A new turbulence model suited for calculating the turbulent Prandtl number as part of the solution is presented. The model is based on a set of two equations: one governing the variance of the enthalpy and the other governing its dissipation rate. These equations were derived from the exact energy equation and thus take into consideration compressibility and dissipation terms. The model is used to study two cases involving shock wave/boundary layer interaction at Mach 9.22 and Mach 5.0. In general, heat transfer prediction showed great improvement over traditional turbulence models where the turbulent Prandtl number is assumed constant. It is concluded that using a model that calculates the turbulent Prandtl number as part of the solution is the key to bridging the gap between theory and experiment for flows dominated by shock wave/boundary layer interactions.

Gaffney, R. L., Jr.; Xiao, X.; Edwards, J. R.; Hassan, H. A.

2005-01-01

498

Rayleigh-Bénard convection at high Rayleigh number and infinite Prandtl number: Asymptotics and numerics  

NASA Astrophysics Data System (ADS)

The problem of fast viscous steady Rayleigh-Bénard convection in a rectangular enclosure is revisited using asymptotic and numerical methods. There are two generic cases: in the first, there is zero shear stress at all boundaries; in the second, there is zero shear stress at the vertical boundaries, but no slip at the horizontal ones. For the first case, we reconcile our new numerical solutions to the full equations with earlier asymptotic results for large Rayleigh number and effectively infinite Prandtl number. For the second case, we first derive the corresponding asymptotic theory and then reconcile it also with the relevant full numerical solutions. However, the latter also indicate behavior which the asymptotic theory does not predict, for Rayleigh numbers in excess of just over 106 and aspect ratios in excess of around 1.1.

Vynnycky, M.; Masuda, Y.

2013-11-01

499

Role of Turbulent Prandtl Number on Heat Flux at Hypersonic Mach Numbers  

NASA Technical Reports Server (NTRS)

A new turbulence model suited for calculating the turbulent Prandtl number as part of the solution is presented. The model is based on a set of two equations: one governing the variance of the enthalpy and the other governing its dissipation rate. These equations were derived from the exact energy equation and thus take into consideration compressibility and dissipation terms. The model is used to study two cases involving shock wave/boundary layer interaction at Mach 9.22 and Mach 5.0. In general, heat transfer prediction showed great improvement over traditional turbulence models where the turbulent Prandtl number is assumed constant. It is concluded that using a model that calculates the turbulent Prandtl number as part of the solution is the key to bridging the gap between theory and experiment for flows dominated by shock wave/boundary layer interactions.

Xiao, X.; Edwards, J. R.; Hassan, H. A.; Gaffney, R. L., Jr.

2007-01-01

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Primary Students' Success on the Structured Number Line  

ERIC Educational Resources Information Center

Number lines are part of people's everyday life and are frequently used in primary mathematics as instructional aids, in texts, and for assessment purposes on mathematics tests. There are two types of number lines; (1) structured number lines, which are the focus of this paper; and (2) empty number lines. Structured number lines represent…

Diezmann, Carmel M.; Lowrie, Tom; Sugars, Lindy A.

2010-01-01