17,371 research outputs found
Living Through the Looking Glass
In Lewis Carrollās (1871, 1992) well-known poem from Through the Looking Glass, āJabberwockyā, nonsense words combine with known English words to create a whimsical effect appealing to readers of all ages. The words seem to gambol and dance in the ear as one imagines the valiant son with the bloody āvorpal swordā in one hand and the head of the monstrous Jabberwock in the other as he goes āgalumphingā back to his father (Carroll,1871, 1992). Alice senses there is meaning in the poem but confesses that she cannot quite understand it. She exclaims, āāSomehow it seems to fill my head with ideas āonly I donāt exactly know what they are! However, somebody killed something: thatās clear, at any rateāāā (p. 182). Figuring out what words āmeanā, or the interpretation of text, is a complex and contested undertaking. Like Alice, readers often sense that they grasp the meaning but certainty eludes them. Determining the meaning of a text or ācomprehensionā is a crucial issue for teachers at all levels. Although reading theorists fundamentally disagree on how reading should be taught, comprehension lies at the heart of reading instruction, regardless of which approach to reading one favors.
Born just after 1900, Louise M. Rosenblatt, literary critic and English educator, has powerfully influenced reading instruction for six decades. The purpose of this paper is to summarize Louise Rosenblattās transactional theory of reader response, to evaluate her work from a biblically informed frame of reference and to suggest practical implications for Christian teachers
Pseudo-random Sequences Generated by Cellular Automata
International audienceGeneration of pseudo random sequences by cellular automata, as well as by hybrid cellular automata is surveyed. An application to the fast evaluation and FPGA implementation of some classes of boolean functions is sketched out
Trends in qualitative research in language teaching since 2000
This paper reviews developments in qualitative research in language teaching since the year 2000, focusing on its contributions to the field and identifying issues that emerge. Its aims are to identify those areas in language teaching where qualitative research has the greatest potential and indicate what needs to be done to further improve the quality of its contribution. The paper begins by highlighting current trends and debates in the general area of qualitative research and offering a working definition of the term. At its core is an overview of developments in the new millennium based on the analysis of papers published in 15 journals related to the field of language teaching and a more detailed description, drawn from a range of sources, of exemplary contributions during that period. Issues of quality are also considered, using illustrative cases to point to aspects of published research that deserve closer attention in future work, and key publications on qualitative research practice are reviewed
Does gender matter? A cross-national investigation of primary class-room discipline.
Ā© 2018 Informa UK Limited, trading as Taylor & Francis GroupFewer than 15% of primary school teachers in both Germany and the UK are male. With the on-going international debate about educational performance highlighting the widening gender achievement gap between girl and boy pupils, the demand for more male teachers has become prevalent in educational discourse. Concerns have frequently been raised about the underachievement of boys, with claims that the lack of male ārole modelsā in schools has an adverse effect on boysā academic motivation and engagement. Although previous research has examined āteachingā as institutional talk, menās linguistic behaviour in the classroom remains largely ignored, especially in regard to enacting discipline. Using empirical spoken data collected from four primary school classrooms in both the UK and in Germany, this paper examines the linguistic discipline strategies of eight male and eight female teachers using Interactional Sociolinguistics to address the question, does teacher gender matter?Peer reviewedFinal Accepted Versio
Inter-Organizational Learning and Collective Memory in Small Firms Clusters: an Agent-Based Approach
Literature about Industrial Districts has largely emphasized the importance of both economic and social factors in determining the competitiveness of these particular firms\' clusters. For thirty years, the Industrial District productive and organizational model represented an alternative to the integrated model of fordist enterprise. Nowadays, the district model suffers from competitive gaps, largely due to the increase of competitive pressure of globalization. This work aims to analyze, through an agent-based simulation model, the influence of informal socio-cognitive coordination mechanisms on district\'s performances, in relation to different competitive scenarios. The agent-based simulation approach is particularly fit for this purpose as it is able to represent the Industrial District\'s complexity. Furthermore, it permits to develop dynamic analysis of district\'s performances according to different types of environment evolution. The results of this work question the widespread opinion that cooperative districts can answer to environmental changes more effectively that non-cooperative ones. In fact, the results of simulations show that, in the presence of turbulent scenarios, the best performer districts are those in which cooperation and competition, trust and opportunism balance out.Firm Networks, Collective Memory, Agent Based Models, Uncertainty
Getting in Sync: Revamping Licensure and Preparation for Teachers in Pre-K, Kindergarten and the Early Grades
Outlines the challenges in teacher preparation and licensure, with a focus on pre-K through third grade; promising practices such as increased classroom experience and selectivity; and suggestions for improving teacher preparation programs and policies
Pseudorandom sequence generation using binary cellular automata
Tezin basılısı Ä°stanbul Åehir Ćniversitesi KĆ¼tĆ¼phanesi'ndedir.Random numbers are an integral part of many applications from computer simulations,
gaming, security protocols to the practices of applied mathematics and physics. As
randomness plays more critical roles, cheap and fast generation methods are becoming a
point of interest for both scientiļ¬c and technological use.
Cellular Automata (CA) is a class of functions which attracts attention mostly due to the
potential it holds in modeling complex phenomena in nature along with its discreteness
and simplicity. Several studies are available in the literature expressing its potentiality
for generating randomness and presenting its advantages over commonly used random
number generators.
Most of the researches in the CA ļ¬eld focus on one-dimensional 3-input CA rules. In
this study, we perform an exhaustive search over the set of 5-input CA to ļ¬nd out the
rules with high randomness quality. As the measure of quality, the outcomes of NIST
Statistical Test Suite are used.
Since the set of 5-input CA rules is very large (including more than 4.2 billions of rules),
they are eliminated by discarding poor-quality rules before testing.
In the literature, generally entropy is used as the elimination criterion, but we preferred
mutual information. The main motive behind that choice is to ļ¬nd out a metric for
elimination which is directly computed on the truth table of the CA rule instead of the
generated sequence. As the test results collected on 3- and 4-input CA indicate, all rules
with very good statistical performance have zero mutual information. By exploiting this
observation, we limit the set to be tested to the rules with zero mutual information. The
reasons and consequences of this choice are discussed.
In total, more than 248 millions of rules are tested. Among them, 120 rules show out-
standing performance with all attempted neighborhood schemes. Along with these tests,
one of them is subjected to a more detailed testing and test results are included.
Keywords: Cellular Automata, Pseudorandom Number Generators, Randomness TestsContents
Declaration of Authorship ii
Abstract iii
Ćz iv
Acknowledgments v
List of Figures ix
List of Tables x
1 Introduction 1
2 Random Number Sequences 4
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2 Theoretical Approaches to Randomness . . . . . . . . . . . . . . . . . . . 5
2.2.1 Information Theory . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2.2 Complexity Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2.3 Computability Theory . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.3 Random Number Generator Classiļ¬cation . . . . . . . . . . . . . . . . . . 7
2.3.1 Physical TRNGs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3.2 Non-Physical TRNGs . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.3.3 Pseudorandom Number Generators . . . . . . . . . . . . . . . . . . 10
2.3.3.1 Generic Design of Pseudorandom Number Generators . . 10
2.3.3.2 Cryptographically Secure Pseudorandom Number Gener- ators . . . . . . . . . . . . . .11
2.3.4 Hybrid Random Number Generators . . . . . . . . . . . . . . . . . 13
2.4 A Comparison between True and Pseudo RNGs . . . . . . . . . . . . . . . 14
2.5 General Requirements on Random Number Sequences . . . . . . . . . . . 14
2.6 Evaluation Criteria of PRNGs . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.7 Statistical Test Suites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.8 NIST Test Suite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.8.1 Hypothetical Testing . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.8.2 Tests in NIST Test Suite . . . . . . . . . . . . . . . . . . . . . . . . 20
2.8.2.1 Frequency Test . . . . . . . . . . . . . . . . . . . . . . . . 20
2.8.2.2 Block Frequency Test . . . . . . . . . . . . . . . . . . . . 20
2.8.2.3 Runs Test . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.8.2.4 Longest Run of Ones in a Block . . . . . . . . . . . . . . 21
2.8.2.5 Binary Matrix Rank Test . . . . . . . . . . . . . . . . . . 21
2.8.2.6 Spectral Test . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.8.2.7 Non-overlapping Template Matching Test . . . . . . . . . 22
2.8.2.8 Overlapping Template Matching Test . . . . . . . . . . . 22
2.8.2.9 Universal Statistical Test . . . . . . . . . . . . . . . . . . 23
2.8.2.10 Linear Complexity Test . . . . . . . . . . . . . . . . . . . 23
2.8.2.11 Serial Test . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.8.2.12 Approximate Entropy Test . . . . . . . . . . . . . . . . . 24
2.8.2.13 Cumulative Sums Test . . . . . . . . . . . . . . . . . . . . 24
2.8.2.14 Random Excursions Test . . . . . . . . . . . . . . . . . . 24
2.8.2.15 Random Excursions Variant Test . . . . . . . . . . . . . . 25
3 Cellular Automata 26 3.1 History of Cellular Automata . . . . . . . . . . . . . . . . . . . . . . . .26
3.1.1 von Neumannās Work . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.1.2 Conwayās Life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.1.3 Wolframās Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.2 Cellular Automata and the Deļ¬nitive Parameters . . . . . . . . . . . . . . 31
3.2.1 Lattice Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.2.2 Cell Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.2.3 Guiding Rule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.2.4 Neighborhood Scheme . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.3 A Formal Deļ¬nition of Cellular Automata . . . . . . . . . . . . . . . . . . 37
3.4 Elementary Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.5 Rule Families . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
3.6 Producing Randomness via Cellular Automata . . . . . . . . . . . . . . . 42
3.6.1 CA-Based PRNGs . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3.6.2 Balancedness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
3.6.3 Mutual Information . . . . . . . . . . . . . . . . . . . . . . . . . . 44
3.6.4 Entropy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4 Test Results 47 4.1 Output of a Statistical Test . . . . . . . . . . . . . . . . . . . . . . . . . . 48
4.2 Testing Strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
4.3 Interpretation of the Test Results . . . . . . . . . . . . . . . . . . . . . . . 49
4.3.1 Rate of success over all trials . . . . . . . . . . . . . . . . . . . . . 49
4.3.2 Distribution of P-values . . . . . . . . . . . . . . . . . . . . . . . . 50
4.4 Testing over a big space of functions . . . . . . . . . . . . . . . . . . . . . 50
4.5 Our Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
4.6 Results and Observations . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
4.6.1 Change in State Width . . . . . . . . . . . . . . . . . . . . . . . . 53
4.6.2 Change in Neighborhood Scheme . . . . . . . . . . . . . . . . . . . 53
4.6.3 Entropy vs. Statistical Quality . . . . . . . . . . . . . . . . . . . . 58
4.6.4 Mutual Information vs. Statistical Quality . . . . . . . . . . . . . . 60
4.6.5 Entropy vs. Mutual Information . . . . . . . . . . . . . . . . . . . 62
4.6.6 Overall Test Results of 4- and 5-input CA . . . . . . . . . . . . . . 6
4.7 The simplest rule: 1435932310 . . . . . . . . . . . . . . . . . . . . . . . . . 68
5 Conclusion 74
A Test Results for Rule 30 and Rule 45 77
B 120 Rules with their Shortest Boolean Formulae 80
Bibliograph
Building Correlation Immune Functions from Sets of Mutually Orthogonal Cellular Automata
Correlation immune Boolean functions play an important role in the implementation of efficient masking countermeasures for side-channel attacks in cryptography. In this paper, we investigate a method to construct correlation immune functions through families of mutually orthogonal cellular automata (MOCA). First, we show that the orthogonal array (OA) associated to a family of MOCA can be expanded to a binary OA of strength at least 2. To prove this result, we exploit the characterization of MOCA in terms of orthogonal labelings on de Bruijn graphs. Then, we use the resulting binary OA to define the support of a second-order correlation immune function. Next, we perform some computational experiments to construct all such functions up to variables, and observe that their correlation immunity order is actually greater, always at least 3. We conclude by discussing how these results open up interesting perspectives for future research, with respect to the search of new correlation-immune functions and binary orthogonal arrays
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