1,721,104 research outputs found
Anoxic Biodegradation of Isosaccharinic Acids at Alkaline pH by Natural Microbial Communities
No full textOne design concept for the long-term management of the UK’s intermediate level radioactive
wastes (ILW) is disposal to a cementitious geological disposal facility (GDF). Under the
alkaline (10.013.0) anoxic conditions expected within a GDF, cellulosic wastes will
undergo chemical hydrolysis. The resulting cellulose degradation products (CDP) are dominated
by α- and β-isosaccharinic acids (ISA), which present an organic carbon source that
may enable subsequent microbial colonisation of a GDF. Microcosms established from neutral,
near-surface sediments demonstrated complete ISA degradation under methanogenic
conditions up to pH 10.0. Degradation decreased as pH increased, with β-ISA fermentation
more heavily influenced than α-ISA. This reduction in degradation rate was accompanied
by a shift in microbial population away from organisms related to Clostridium sporosphaeroides
to a more diverse Clostridial community. The increase in pH to 10.0 saw an increase
in detection of Alcaligenes aquatilis and a dominance of hydrogenotrophic methanogens
within the Archaeal population. Methane was generated up to pH 10.0 with acetate accumulation
at higher pH values reflecting a reduced detection of acetoclastic methanogens. An
increase in pH to 11.0 resulted in the accumulation of ISA, the absence of methanogenesis
and the loss of biomass from the system. This study is the first to demonstrate methanogenesis
from ISA by near surface microbial communities not previously exposed to these compounds
up to and including pH 10.0
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
CIGARCoil: A New Algorithm for the Compression of DNA Sequencing Data
Get PDFDNA sequencing machines produce tens of thousands to hundreds of millions of reads. Each read
consists of letters from the alphabet X= {A, T, C, G, N} and varies in length between 30 to 120 characters
and beyond. The DNA reads are stored in a standard FASTQ file format that contains not only the reads
but also a quality score for each character in each read that corresponds to the probability that the
identified character is correct. The FASTQ files vary in size between 100s of megabytes to 10s of
gigabytes. The reads in the FASTQ files are processed as part of many DNA algorithms for various
sequence analyses. Given the fact that the size of each file is considerable, keeping and handling
multiple of these files in main memory for faster processing is not possible on commodity hardware. In
this thesis, we propose a lossless compression mechanism named CIGARCoil that operates on the FASTQ
files and other files that contain the DNA reads. The other salient features of CIGARCoil are:
• It is a not a reference-based algorithm in the sense that one does not need to create a reference
string before the compression can begin. Reference strings are undesirable due to them not only
being hard to determine, but also due to them being required for both the compression and
decompression of the file.
• In this thesis, for the first time, we show that each of the reads can be accessed directly on the
compressed structure created by CIGARCoil. That is, we provide access to each read without
having to uncompress the file.
• Since we can provide direct access to a read on the CIGARCoil compressed structure, we have
implemented a [] (square-bracket) array indexing operator. Through this implementation, we
can implement a predictive caching mechanism that will make the reads available for the enduser based on their access pattern.
We have analyzed our compressed mechanism on various well-known FASTQ data sets along with
synthetic data sets. In all cases, our compression method produces a compressed file that is smaller or
approximately the same size as ones created by the existing DNA compression mechanisms, including
BZIP, DSRC2, and LFQC
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Efficient Neural Architecture Search using Genetic Algorithm
Get PDFNASNet and AmoebaNet are state-of-the-art neural architecture search systems
that were able to achieve better accuracy than state-of-the-art human-made convolutional neural networks. Despite the innovation of the NASNet search space,
it lacks the ability to express flexibility in terms of optimizing non-convolutional
operation layers, such as batch normalization, activation, and dropout. These
layers are hand designed by the architect prior to optimization, limiting the exploration possible for model architectures by narrowing down the search space.
In addition, the NASNet search space can not allow for many non-classical optimization techniques to be applied as it lacks the ability to be expressed in a
fixed-length, floating-point, multidimensional array. Lastly, both NASNet and
AmoebaNet use an extensive amount of computation, both evaluating 20,000
models during optimization, consuming 2,000 GPU hours worth of computation.
This work addresses these limitations by, first, changing the NASNet search space
to include optimization of non-convolutional operation layers through the addition of a building block that allows for the optimization for the order and inclusion
of these layers; second, proposing a fixed-length, floating-point, multidimensional
array representation to allow other non-classical optimization techniques, such
as particle swarm optimization, to be applied; and third, proposing an efficient
genetic algorithm, while using state of-the-art techniques to reduce training comiv
plexity. After only 1,300 models evaluated, consuming 190 GPU hours, evolving
on the CIFAR-10 benchmark dataset, the best model configuration yielded a test
accuracy of 94.6% with only 1.3 million parameters, and a test accuracy of 95.09%
with only 5.17 million parameters, outperforming both ResNet110 and WideResNet. When transferring to the CIFAR-100 benchmark dataset, the best model
configuration yielded a test accuracy of 71.1% with only 1.3 million parameters,
and a test accuracy of 76.53% with only 5.17 million parameters
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Accelerating Distributed Synthetic Aperture Radar Data Simulations Via CUDA
Get PDFA general simulation of distributed synthetic aperture radar (DSAR) data is useful to evaluate the theoretical performance of a DSAR system and its underlying algorithms without a deployed system in place. Simulating DSAR is a computationally intensive task due to the size and complexity of the resultant data, but a simulation must complete within a reasonable amount of time to be a useful tool in practice. Through the use of both MATLAB and CUDA, a DSAR simulation can be flexible and modifiable while benefiting from efficiently implemented GPU acceleration. Multiple simulation programs have been developed using these programming languages to explore techniques of parallelizing and optimizing the performance of DSAR data simulation
Kidney OCT 3D images classification using machine learning
Get PDFThe goal of this research is to make a classification program for 3D images by using a CNN model. The images to classify are kidney images that have 3 different classes: Pelvis, Medulla and Cortex.
To do so, a data preprocessing was needed. The data preprocessing went through two big steps: cropping the 3D images to have smaller image volume and rotating the images to get a data enrichment.
\bigskip
After that data preprocessing, the next step is to build a model that can achieve a better accuracy than 2D models that were used previously
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
