219 research outputs found
Enabling Non-Linear Quantum Operations through Variational Quantum Splines
The postulates of quantum mechanics impose only unitary transformations on
quantum states, which is a severe limitation for quantum machine learning
algorithms. Quantum Splines (QSplines) have recently been proposed to
approximate quantum activation functions to introduce non-linearity in quantum
algorithms. However, QSplines make use of the HHL as a subroutine and require a
fault-tolerant quantum computer to be correctly implemented. This work proposes
the Generalised QSplines (GQSplines), a novel method for approximating
non-linear quantum activation functions using hybrid quantum-classical
computation. The GQSplines overcome the highly demanding requirements of the
original QSplines in terms of quantum hardware and can be implemented using
near-term quantum computers. Furthermore, the proposed method relies on a
flexible problem representation for non-linear approximation and it is suitable
to be embedded in existing quantum neural network architectures. In addition,
we provide a practical implementation of GQSplines using Pennylane and show
that our model outperforms the original QSplines in terms of quality of
fitting
Software engineering to sustain a high-performance computing scientific application: QMCPACK
We provide an overview of the software engineering efforts and their impact
in QMCPACK, a production-level ab-initio Quantum Monte Carlo open-source code
targeting high-performance computing (HPC) systems. Aspects included are: (i)
strategic expansion of continuous integration (CI) targeting CPUs, using GitHub
Actions runners, and NVIDIA and AMD GPUs in pre-exascale systems, using
self-hosted hardware; (ii) incremental reduction of memory leaks using
sanitizers, (iii) incorporation of Docker containers for CI and
reproducibility, and (iv) refactoring efforts to improve maintainability,
testing coverage, and memory lifetime management. We quantify the value of
these improvements by providing metrics to illustrate the shift towards a
predictive, rather than reactive, sustainable maintenance approach. Our goal,
in documenting the impact of these efforts on QMCPACK, is to contribute to the
body of knowledge on the importance of research software engineering (RSE) for
the sustainability of community HPC codes and scientific discovery at scale.Comment: Accepted at the first US-RSE Conference, USRSE2023,
https://us-rse.org/usrse23/, 8 pages, 3 figures, 4 table
Investigation on Data Adaptation Techniques for Neural Named Entity Recognition
Data processing is an important step in various natural language processing
tasks. As the commonly used datasets in named entity recognition contain only a
limited number of samples, it is important to obtain additional labeled data in
an efficient and reliable manner. A common practice is to utilize large
monolingual unlabeled corpora. Another popular technique is to create synthetic
data from the original labeled data (data augmentation). In this work, we
investigate the impact of these two methods on the performance of three
different named entity recognition tasks.Comment: ACL SRW 2021 - camera read
A new multi-criteria approach for sustainable material selection problem
Sustainable material selection is a crucial problem given the new demands of society and novel production strategies that consider the concepts of sustainability. Multi-criteria decision-making methods have been extensively used to help decision-makers select alternatives in different fields of knowledge. Nonetheless, these methods have been criticized due to the rank reversal problem, where the independence of the irrelevant alternative principle is violated after the initial decision problem is changed. Over the course of this study, we observed that the solutions that are proposed for this problem, in the context of sustainable material selection, are insufficient. Thus, we present a new material selection approach that is based on the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method, which is immune to rank reversal. We also demonstrate the causes of rank reversal in the TOPSIS method, how the R-TOPSIS method was designed to solve them, and how it can be applied to sustainable material selection
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