2,506 research outputs found

    Automata with Nested Pebbles Capture First-Order Logic with Transitive Closure

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    String languages recognizable in (deterministic) log-space are characterized either by two-way (deterministic) multi-head automata, or following Immerman, by first-order logic with (deterministic) transitive closure. Here we elaborate this result, and match the number of heads to the arity of the transitive closure. More precisely, first-order logic with k-ary deterministic transitive closure has the same power as deterministic automata walking on their input with k heads, additionally using a finite set of nested pebbles. This result is valid for strings, ordered trees, and in general for families of graphs having a fixed automaton that can be used to traverse the nodes of each of the graphs in the family. Other examples of such families are grids, toruses, and rectangular mazes. For nondeterministic automata, the logic is restricted to positive occurrences of transitive closure. The special case of k=1 for trees, shows that single-head deterministic tree-walking automata with nested pebbles are characterized by first-order logic with unary deterministic transitive closure. This refines our earlier result that placed these automata between first-order and monadic second-order logic on trees.Comment: Paper for Logical Methods in Computer Science, 27 pages, 1 figur

    Dual Language: It\u27s Effectiveness and How it Impacts Learning With Regards to Science Taught Thematicly in Elementary

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    The primary purpose of this project is to develop a month long integrated thematic unit for 2nd graders in a dual language program that address research findings in the area of effective student learning in dual language programs. Incorporation of science methodology, ESL strategies, and thematic teaching are also researched for effectiveness and addressed in the project. Dual Language and its effectiveness will also be compared to other bilingual programs. Dual language with appropriate implementation increases student achievement in learning a second language (Kirk, 2002)

    Introduction

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    Introduction to genericity in the nominal, verbal and sentential domain

    Ants and Fairies: The Debate with Darwinism in A. S. Byatt’s Morpho Eugenia

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    Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 dofinansowane zostało ze środków MNiSW w ramach działalności upowszechniającej nauk

    Ten Quick Tips for Using a Raspberry Pi

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    Much of biology (and, indeed, all of science) is becoming increasingly computational. We tend to think of this in regards to algorithmic approaches and software tools, as well as increased computing power. There has also been a shift towards slicker, packaged solutions--which mirrors everyday life, from smart phones to smart homes. As a result, it's all too easy to be detached from the fundamental elements that power these changes, and to see solutions as "black boxes". The major goal of this piece is to use the example of the Raspberry Pi--a small, general-purpose computer--as the central component in a highly developed ecosystem that brings together elements like external hardware, sensors and controllers, state-of-the-art programming practices, and basic electronics and physics, all in an approachable and useful way. External devices and inputs are easily connected to the Pi, and it can, in turn, control attached devices very simply. So whether you want to use it to manage laboratory equipment, sample the environment, teach bioinformatics, control your home security or make a model lunar lander, it's all built from the same basic principles. To quote Richard Feynman, "What I cannot create, I do not understand".Comment: 12 pages, 2 figure

    The earliest iron-producing communities in the Lower Congo region of Central Africa : new insights from the Bu, Kindu and Mantsetsi sites

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    In 2015 the KongoKing research project team excavated the Bu, Kindu and Mantsetsi sites situated in the Kongo-Central Province of the Democratic Republic of Congo (DRC). All are part of the Kay Ladio Group. This is the first detailed publication on this cultural group, to which no contemporary ones can currently be linked, either from the Atlantic coast of Congo-Brazzaville or from along the Congo River and its tributaries upstream of Kinshasa. Dated to between cal. AD 30 and 475, these settlements mark the presence of what are so far the oldest known iron-producing communities south of the Central African equatorial forest. Evidence for metallurgy is associated with remants of polished stone axes, which were perhaps being used for ritual purposes by this point in time. The charcoal remains found at the sites indicate a savanna environment that was more wooded in Kindu and Mantsetsi than in Bu

    Semantic and pragmatic motivations for constructional preferences: a corpus-based study of provide, supply, and present

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    A select group of transfer verbs can enter into four different constructions: the ditransitive construction (He provided John the money), the prepositional-dative construction (He provided the money to John), a construction with a prepositional theme (He provided John with the money), and a construction with a recipient realized by a for-phrase (He provided the money for John). In this article, we take a close look at three such verbs: provide, supply, and present. Corpus analysis shows that these three verbs display different structural preferences with respect to the for-, to-, and with-patterns. To explain these preferences, the study investigates pragmatic principles (following Mukherjee 2001 on provide) and the role played by semantic factors. An examination of the semantics of the verbs and the lexically motivated constructional semantics of the to, for, and with-patterns shows (i) that the three constructions are not interchangeable, and (ii) that the preferential differences between the three verbs find an explanation in the compatibility between lexical and constructional semantics. The description is mainly based on data from the British National Corpus

    From caterpillars to butterflies: exploring pre-service teachers’ transformations while navigating global citizenship education

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    Global citizenship education (GCE), which aims to empower learners to become proactive contributors to a more sustainable world, has recently emerged as one of the educational priorities of the 21st century. However, according to recent research, GCE is not yet embedded in teachers’ practice in a systematic manner, remaining an optional choice for willing and able teachers. Within this framework, this paper reports on a multiple case study conducted with a group of pre-service teachers (PSTs) in Portugal who were introduced to GCE in the third and final year of an undergraduate degree in Elementary Education. The study aimed to understand whether, how and to what extent the teacher education program contributed to PSTs’ professional development. Data consisted of individual reflections written by the PSTs throughout an academic year. These were analyzed thematically using grounded theory to formulate an original framework inspired by the butterfly’s metamorphosis. Results show that the experience with GCE was positive in developing PSTs’ professional knowledge and in helping them (re)construct their “becoming” teacher identities, albeit to different degrees. Implications of the results for teacher education programs are discussed.publishe

    Monitoring the defoliation of hardwood forests in Pennsylvania using LANDSAT

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    An automated system for conducting annual gypsy moth defoliation surveys using LANDSAT MSS data and digital processing techniques is described. A two-step preprocessing procedure was developed that uses multitemporal data sets representing forest canopy conditions before and after defoliation to create a digital image in which all nonforest cover types are eliminated or masked out of a LANDSAT image that exhibits insect defoliation. A temporal window for defoliation assessment was identified and a statewide data base was established. A data management system to interface image analysis software with the statewide data base was developed and a cost benefit analysis of this operational system was conducted
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