Search results for "Neural"
showing 10 items of 2783 documents
Monte Carlo and molecular dynamics simulation of the glass transition of polymers
1998
Two coarse-grained models for polymer chains in dense glass-forming polymer melts are studied by computer simulation: the bond-fluctuation model on a simple cubic lattice, where a bond-length potential favors long bonds, is treated by dynamic Monte Carlo methods, and a bead-spring model in the continuum with a Lennard-Jones potential between the beads is treated by Molecular Dynamics. While the dynamics of both models differ for short length scales and associated time scales, on mesoscopic spatial and temporal scales both models behave similarly. In particular, the mode coupling theory of the glass transition can be used to interpret the slowing down of the undercooled polymer melt. For the…
Facilitating polymer conjugation via combination of RAFT polymerization and activated ester chemistry
2010
The synthesis of block copolymers via polymer conjugation of well-defined building blocks offers excellent control over the structures obtained, but often several coupling strategies need to be explored to find an efficient one depending on the building blocks. To facilitate the synthesis of polymers with adjustable functional end-groups for polymer conjugation, we report on the combination of activated ester chemistry with RAFT polymerization using a chain transfer agent (CTA) with a pentafluorophenyl ester (PFP-CTA), which allows for flexible functionalization of either the CTA prior to polymerization or the obtained polymer after polymerization. Different polymethacrylates, namely PMMA, …
Interfacial properties of glassy polymer melts: A Monte Carlo study
1996
The properties of the interface between a polymer melt and a solid wall are studied over a wide range of temperatures by dynamic Monte Carlo simulations. It is shown that in the supercooled state near the glass transition of the melt an “interphase” forms, the structure of which is influenced by the wall. The thickness of this interphase is determined from the monomer density profile near the surface and is strongly temperature dependent. At low glass-like temperatures it is larger than the bulk radius of gyration of the chains.
Optical Hole Burning and Thermal Irreversibility of Non-Ergodic Systems: Polymers, Proteins, Glasses
1989
A spectral hole is used to probe configurational dynamics of non-ergodic systems far below the glass transition temperature
From orientational glasses to structural glasses: What computer simulations have contributed to understand experiments
2002
Abstract Orientational glasses, produced by random dilution of molecular crystals, exhibit a freezing transition of the quadrupole moments. Monte Carlo simulations of lattice models (generalization of the Edwards–Anderson spin glass model) have been used to elucidate this behavior. While short range models exhibit a static glass transition at zero temperature only, the infinite range Potts glass exhibits a transition where a glass order parameter appears discontinuously. At higher temperature, a dynamical transition occurs, described by mode-coupling theory (MCT). MCT has also been tested by Monte Carlo and molecular dynamics simulations of coarse-grained models of glass-forming polymers. W…
El stent como puente a la cirugía en la obstrucción maligna de colon. Estudio del impacto oncológico de la perforación relacionada con el stent y de …
2021
El uso del stent como puente a la cirugía en la obstrucción maligna de colon es un motivo actual de controversia y preocupación, debido a los resultados oncológicos a largo plazo observados en algunos estudios recientemente publicados. OBJETIVOS: El objetivo de nuestro estudio fue analizar el impacto de la perforación relacionada con el stent y los cambios anatomopatológicos que ocasiona su colocación en los pacientes candidatos a tratamiento curativo por obstrucción maligna de colon, con el fin de determinar su influencia en los resultados oncológicos a largo plazo. MATERIAL Y MÉTODO: Se llevaron a cabo dos revisiones sistemáticas y metaanálisis según la metodología PRISMA. En el metaanáli…
Can Physiological and Psychological Factors Predict Dropout from Intense 10-Day Winter Military Survival Training?
2020
Background: In the military context, high levels of physiological and psychological stress together can compromise individual&rsquo
Neuromuscular adaptations to single-session combined strength and endurance training in untrained men : an examination of the order effect
2013
Understanding the adaptations to single-session combined strength (S) and endurance (E) training has received increased attention in scientific literature through the expand-ing use of combined training programs for practical purposes. However, the intra-session exercise order when performing both E and S in the same training session may limit potential strength development, as the neuromuscular adaptations to either training mode alone are very different. Research on the effect of the intra-session exercise order of combined training on various training-induced adaptations, i.e. the order effect, is currently limited, especially with regard to the neuromuscular adaptations. Therefore, the …
CHANGING PERSPECTIVE ON PERCEPTION PHYSIOLOGY: CAN YOU REALLY SEE WHAT IS HAPPENING?
2018
Perception is a complex, neural mechanism that requires organization and interpretation of input meaning and it has been a key topic in medicine, neuroscience and philosophy for centuries. Gestalt psychology proposed that the underlying mechanism is a constructive process that depends on both input of stimuli and the sensory-motor state of the agent. The Bayesian Brain hypothesis reframed it as probabilistic inference of previous beliefs, which are revised to accommodate new information. The Predictive Coding Theory proposes that this process is implemented through a top-down cascade of cortical predictions of lower level input and the concurrent propagation of a bottom-up prediction error …
LightSleepNet: A Lightweight Deep Model for Rapid Sleep Stage Classification with Spectrograms.
2021
Deep learning has achieved unprecedented success in sleep stage classification tasks, which starts to pave the way for potential real-world applications. However, due to its enormous size, deployment of deep neural networks is hindered by high cost at various aspects, such as computation power, storage, network bandwidth, power consumption, and hardware complexity. For further practical applications (e.g., wearable sleep monitoring devices), there is a need for simple and compact models. In this paper, we propose a lightweight model, namely LightSleepNet, for rapid sleep stage classification based on spectrograms. Our model is assembled by a much fewer number of model parameters compared to…