736 research outputs found
Challenging the Conceptual Limits in Health Psychology:Using the Concept of Conduct of Life to Study People’s Health Activities from a Social and Subjective Perspective
This contribution explores the connection between health and subjectivity. Up until recently a marginally discussed topic in health theories, recent critical research in health psychology introduces notions of subjectivity to theories of health. These notions can be linked to phenomenology, embodied subjectivity, and psychosocial theories that have moved away from a partial, internal understanding of subjectivity. These recent theories tend to define subjectivity as a coherence of concrete, embodied and situated subjectivity that extends capabilities and activities towards a world of social relations. The article at hand shows that embodied and situated subjectivity is a basic function of health that sustains the qualities of human life. To comprehend health as a subjective practice in human lives, we need an understanding of people’s subjective participation in their everyday social lives. Hence, I will argue for the concept of conduct of life as an important concept for health psychology. The concept of conduct of life enables an analysis of how people conduct their activities and of their access to life possibilities, within social settings and societal power systems. The concept can be used to analyse the connection between subjectivity and health in the cultural and social relations by which people actually live
On the Implementation Complexity of Digital Full-Duplex Self-Interference Cancellation
In-band full-duplex systems promise to further increase the throughput of
wireless systems, by simultaneously transmitting and receiving on the same
frequency band. However, concurrent transmission generates a strong
self-interference signal at the receiver, which requires the use of
cancellation techniques. A wide range of techniques for analog and digital
self-interference cancellation have already been presented in the literature.
However, their evaluation focuses on cases where the underlying physical
parameters of the full-duplex system do not vary significantly. In this paper,
we focus on adaptive digital cancellation, motivated by the fact that physical
systems change over time. We examine some of the different cancellation methods
in terms of their performance and implementation complexity, considering the
cost of both cancellation and training. We then present a comparative analysis
of all these methods to determine which perform better under different system
performance requirements. We demonstrate that with a neural network approach,
the reduction in arithmetic complexity for the same cancellation performance
relative to a state-of-the-art polynomial model is several orders of magnitude.Comment: Presented at the 2020 Asilomar Conference for Signals, Systems, and
Computer
cphVB: A System for Automated Runtime Optimization and Parallelization of Vectorized Applications
Modern processor architectures, in addition to having still more cores, also
require still more consideration to memory-layout in order to run at full
capacity. The usefulness of most languages is deprecating as their
abstractions, structures or objects are hard to map onto modern processor
architectures efficiently.
The work in this paper introduces a new abstract machine framework, cphVB,
that enables vector oriented high-level programming languages to map onto a
broad range of architectures efficiently. The idea is to close the gap between
high-level languages and hardware optimized low-level implementations. By
translating high-level vector operations into an intermediate vector bytecode,
cphVB enables specialized vector engines to efficiently execute the vector
operations.
The primary success parameters are to maintain a complete abstraction from
low-level details and to provide efficient code execution across different,
modern, processors. We evaluate the presented design through a setup that
targets multi-core CPU architectures. We evaluate the performance of the
implementation using Python implementations of well-known algorithms: a jacobi
solver, a kNN search, a shallow water simulation and a synthetic stencil
simulation. All demonstrate good performance
Identification of Non-Linear RF Systems Using Backpropagation
In this work, we use deep unfolding to view cascaded non-linear RF systems as
model-based neural networks. This view enables the direct use of a wide range
of neural network tools and optimizers to efficiently identify such cascaded
models. We demonstrate the effectiveness of this approach through the example
of digital self-interference cancellation in full-duplex communications where
an IQ imbalance model and a non-linear PA model are cascaded in series. For a
self-interference cancellation performance of approximately 44.5 dB, the number
of model parameters can be reduced by 74% and the number of operations per
sample can be reduced by 79% compared to an expanded linear-in-parameters
polynomial model.Comment: To be presented at the 2020 IEEE International Conference on
Communications (Workshop on Full-Duplex Communications for Future Wireless
Networks
Hardware Implementation of Neural Self-Interference Cancellation
In-band full-duplex systems can transmit and receive information
simultaneously on the same frequency band. However, due to the strong
self-interference caused by the transmitter to its own receiver, the use of
non-linear digital self-interference cancellation is essential. In this work,
we describe a hardware architecture for a neural network-based non-linear
self-interference (SI) canceller and we compare it with our own hardware
implementation of a conventional polynomial based SI canceller. In particular,
we present implementation results for a shallow and a deep neural network SI
canceller as well as for a polynomial SI canceller. Our results show that the
deep neural network canceller achieves a hardware efficiency of up to
Msamples/s/mm and an energy efficiency of up to nJ/sample, which is
and better than the polynomial SI canceller,
respectively. These results show that NN-based methods applied to
communications are not only useful from a performance perspective, but can also
be a very effective means to reduce the implementation complexity.Comment: Accepted for publication in IEEE Journal on Emerging and Selected
Topics in Circuits and System
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