Academic literature on the topic 'Twig'

Eastern hemlock (Tsuga canadensis) is a prominent tree in the forests of eastern North America, where it commonly grows along headwater streams. It is experiencing widespread mortality due to infestations of an introduced insect, the hemlock woolly adelgid (Adelges tsugae). Eliminations of tree species are known to have ecosystem-level effects, and one consequence of hemlock death is a change in allochthonous inputs to headwater streams. I predicted that hemlock twigsâ dendritic structure, abundance, and resistance to decay currently make them highly effective retainers of leaves in headwater streams, with consequences for nutrient uptake. To understand the role of hemlock twigs in streams and to compare their functions to those of a potential replacement species, I (1) quantified the decomposition and microbial colonization of twigs and (2) manipulated twig standing crops to quantify effects on leaf retention and nutrient uptake. Hemlock twigs provide a poor-quality substrate for microbial colonization and growth relative to birch (Betula lenta) twigs and are more resistant to breakdown than birch. Although hemlock twigs appear to be effective in retaining leaves, they do not substantially affect reach-scale uptake of ammonium, which is much more strongly influenced by the timing of leaf inputs. Although hemlock death may subtly change patterns of organic matter accumulation and breakdown, the potentially important effects of hemlock death include changes in large wood inputs, changes in hydrologic regime, and increases in rhododendron cover.<br>Master of Science

Programmers design, write, and understand programs with a high-level structure in mind. Existing programming languages are not very good at capturing this structure because they must include low-level implementation details. To address this problem we introduce Twig, a programming language that allows for domain-specific logic to be encoded alongside low-level functionality. Twig's language is based on a simple, formal calculus that is amenable to both human and machine reasoning. Users may introduce rules that rewrite expressions, allowing for user-defined optimizations. Twig can also incorporate procedures written in a variety of low-level languages. Our implementation supports C and Python, but our abstract model can accommodate other languages as well. We present Twig's design and formal semantics and discuss our implementation. We demonstrate Twig's use in two different domains, multi-language programming and GPU programming, and compare Twig against a well-known typemapping system, SWIG.

This thesis charts the role of dance improvisation performance as a practice of ecology by analyzing data collected from a series of experiments in improvisation. Conducted in a number of locations in Europe and Asia, these experiments examine the usefulness of improvisation performance practices to notions of “ecology” and common understandings of humans’ relationships to our environment. Using “ecology” to describe an investigation of interrelationship as well as a commitment to act with an awareness of one’s actions in the social, mental and natural spheres discussed by Felix Guattari (2000), I outline ways contemporary improvisation practices can facilitate this investigation. To do this I draw on my own experience as a dancer at the Performing Arts Research and Training Studios (PARTS) in Brussels from 2004-2006, and as codirector of the TWIG Project in China in 2006. Using the experiences of improvising, learning dance, seeing dance, performing dance, creating scores for dance, and teaching movement improvisation, I argue that ecological practice is defined by its ability to instill a sense of “response ability” and personal agency in its practitioners. As a way of observing and incorporating new knowledge, improvisation functions herein both as a research practice and as the object of study. By improvising and documenting my experiences using a phenomenological lens derived from Merleau-Ponty’s work, I reflect on how practices of awareness in dancing can constitute new ways of knowing. I discuss how improvising can assist awareness of the body’s relationship with the environment at a number of levels including sensory, spatial, temporal, conceptual, social and political. I also investigate the notion of paradox as a theme throughout the thesis and present its usefulness as a way of producing and reflecting upon a practice of bodily research. The term “twig dances” represents an expanded understanding of what I mean by “improvising”, and points to my use of improvisation as a research process. As an action taken “to understand or realize something”, a twig dance is any of a number movement practices which take as their focus an active investigation into relationships between people and the non-human world.

The Extensible Markup Language XML has become the de facto standard for information representation and interchange on the Internet. In this dissertation, I address the problem of indexing and querying XML in two environments, namely, (a) a traditional environment where data is centrally stored and (b) a growingly popular peer-to-peer (P2P) environment. In a traditional enviroment, the index built over XML data is typicallycentralized. On the other hand, due to the distributed nature of the data in a P2P system, the index is also distributed. Due to the different models of storing data in these two environments, I propose two different XML indexing schemes for efficient query processing.In a traditional environment, a core operation is tofind all occurrences of a given query pattern in the database. I propose a new way of indexing XML documents and processing query patterns. Every XML document in the database is transformed into a sequence of labels by Prüfer's method that constructs a one-to-one correspondence between trees and sequences.During query processing, a query pattern is also transformed into its Prüfer sequence. By performing subsequence matching on the set of sequences in the database, and performing a series of refinement phasesthat I have developed, all the occurrences of a query pattern can be found in the database. Furthermore, I show that all correct answers are found without any false dismissals or false alarms. I present the design, implementation, and experimental evaluation of the PRIX system that I have developed for this purpose.Coupled with the growing popularity of P2P systems, XML is commonly used as an underlying data model for P2P applications to handle the heterogeneity of the data and limited expressiveness of queries. Locating relevant data sources across a large number of participating peers is an important challenge. In this environment, the challenge is to quickly test the existence ofa query pattern in XML documents published by usersrather than finding all their occurrences. PRIX finds all occurrences of a query pattern and hence is not the best solution. Moreover, in a P2P environment, a distributed and decentralized index is necessary. Therefore, I propose a distributed indexing scheme for XML documents to quickly test for existence of query patterns based on polynomial signatures. In this scheme,each XML document is mapped into an algebraic signature that captures the structural summary of the document.The participating peers in the network collectively maintain a distributed and hierarchical index over the signatures. By virtue of the signature index, the signatures of documents with similar structural characteristics tend to be stored together at the same peer, and a search for document sources is resolved quickly. I present the design, implementation, and empirical evaluation of the psiX system that I have developed for this purpose. The signature scheme proposed in psiX can be applied to querying heterogeneous XML databases.

Efficient twig pattern matching is essential to XML queries and other tree-based queries. Numerous so-called holistic algorithms have been proposed for efficiently processing the twig patterns in XML queries. However, a more general form of twig pattern, called Boolean-twig (or B-twig for short), which allows arbitrary combination of an arbitrary number of all the three logical connectives, AND, OR, and NOT, in a twig pattern, has not been adequately addressed. The theme of this study is on holistic (and efficient) B-twig pattern matching using region encoding and Dewey encoding schemes. We first adopt region encoding and propose a novel, direct approach called DBTwigMerge for holistic B-twig pattern matching, which although enjoys certain theoretical ``beauty'' and ``elegance'' but does not always outperform our prior approach, BTwigMerge. Based on the experience gained and in-depth investigation, we then come up with another new and more efficient approach, FBTwigMerge, which is proven to be the overall winner among all the holistic approaches using region encoding. In this study, we also studied the holistic B-twig pattern matching problem using Dewey encoding. The unique properties of Dewey encoding bring challenges and also benefits to this problem. By carefully addressing the challenges, this dissertation finally presents the first Dewey based holistic approach, called DeweyNOT, for efficiently solving the pattern matching problem with a subclass of B-twigs, i.e., twig queries involving arbitrary AND/NOT predicates. Extensive experimental studies have been conducted that demonstrate the viability and outstanding performance of the proposed approaches.

Матвієнко, В. І. Розробка сайту ВСП ФКТКТ НУ "ЧП" з електронним журналом користувачів (front- end) : випускна кваліфікаційна робота : 123 "Кoмп’ютepнa iнжeнepiя" / В. І. Матвієнко ; керівник роботи С. С. Стасюк ; НУ "Чернігівська політехніка", кафедра iнфopмaцiйниx тa кoмп’ютepниx cиcтeм. – Чернігів, 2021. – 55 с.<br>Метою теоретичної частити є вивчення існуючих технологій для реалізації акщте-end сайту.<br>The purpose of the theoretical part is to study the existing technologies for the implementation of the front-end site.