keyword
MENU ▼
Read by QxMD icon Read
search

Stochastic

keyword
https://www.readbyqxmd.com/read/28749361/output-feedback-control-of-unknown-linear-discrete-time-systems-with-stochastic-measurement-and-process-noise-via-approximate-dynamic-programming
#1
Jun-Sheng Wang, Guang-Hong Yang
This paper studies the optimal output-feedback control problem for unknown linear discrete-time systems with stochastic measurement and process noise. A dithered Bellman equation with the innovation covariance matrix is constructed via the expectation operator given in the form of a finite summation. On this basis, an output-feedback-based approximate dynamic programming method is developed, where the terms depending on the innovation covariance matrix are available with the aid of the innovation covariance matrix identified beforehand...
July 25, 2017: IEEE Transactions on Cybernetics
https://www.readbyqxmd.com/read/28749345/noise-in-neuronal-and-electronic-circuits-a-general-modeling-framework-and-non-monte-carlo-simulation-techniques
#2
Deniz Kilinc, Alper Demir
The brain is extremely energy efficient and remarkably robust in what it does despite the considerable variability and noise caused by the stochastic mechanisms in neurons and synapses. Computational modeling is a powerful tool that can help us gain insight into this important aspect of brain mechanism. A deep understanding and computational design tools can help develop robust neuromorphic electronic circuits and hybrid neuroelectronic systems. In this paper, we present a general modeling framework for biological neuronal circuits that systematically captures the nonstationary stochastic behavior of ion channels and synaptic processes...
August 2017: IEEE Transactions on Biomedical Circuits and Systems
https://www.readbyqxmd.com/read/28747400/dynamic-disorder-in-simple-enzymatic-reactions-induces-stochastic-amplification-of-substrate
#3
Ankit Gupta, Andreas Milias-Argeitis, Mustafa Khammash
A growing amount of evidence over the last two decades points to the fact that many enzymes exhibit fluctuations in their catalytic activity, which are associated with conformational changes on a broad range of timescales. The experimental study of this phenomenon, termed dynamic disorder, has become possible thanks to advances in single-molecule enzymology measurement techniques, through which the catalytic activity of individual enzyme molecules can be tracked in time. The biological role and importance of these fluctuations in a system with a small number of enzymes, such as a living cell, have only recently started being explored...
July 2017: Journal of the Royal Society, Interface
https://www.readbyqxmd.com/read/28744093/origins-of-the-phototransduction-delay-as-inferred-from-stochastic-and-deterministic-simulation-of-the-amplification-cascade
#4
Alexander Yu Rotov, Luba A Astakhova, Michael L Firsov, Victor I Govardovskii
PURPOSE: To identify steps of the phototransduction cascade responsible for the delay of the photoresponse. METHODS: Electrical responses of fish (Carassius) cones and Rana ridibunda frog rods and cones were recorded with a suction pipette technique and as an aspartate-isolated mass receptor potential from isolated perfused retinas. Special attention was paid to sufficiently high temporal resolution (1-ms flash, 700 Hz amplification bandpass). Stochastic simulation of the activation steps from photon absorption to the formation of catalytically active phosphodiesterase (PDE) was performed...
2017: Molecular Vision
https://www.readbyqxmd.com/read/28743898/achievement-of-sustained-net-plasma-heating-in-a-fusion-experiment-with-the-optometrist-algorithm
#5
E A Baltz, E Trask, M Binderbauer, M Dikovsky, H Gota, R Mendoza, J C Platt, P F Riley
Many fields of basic and applied science require efficiently exploring complex systems with high dimensionality. An example of such a challenge is optimising the performance of plasma fusion experiments. The highly-nonlinear and temporally-varying interaction between the plasma, its environment and external controls presents a considerable complexity in these experiments. A further difficulty arises from the fact that there is no single objective metric that fully captures both plasma quality and equipment constraints...
July 25, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28743895/eternal-non-markovianity-from-random-unitary-to-markov-chain-realisations
#6
Nina Megier, Dariusz Chruściński, Jyrki Piilo, Walter T Strunz
The theoretical description of quantum dynamics in an intriguing way does not necessarily imply the underlying dynamics is indeed intriguing. Here we show how a known very interesting master equation with an always negative decay rate [eternal non-Markovianity (ENM)] arises from simple stochastic Schrödinger dynamics (random unitary dynamics). Equivalently, it may be seen as arising from a mixture of Markov (semi-group) open system dynamics. Both these approaches lead to a more general family of CPT maps, characterized by a point within a parameter triangle...
July 25, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28742083/long-time-analytic-approximation-of-large-stochastic-oscillators-simulation-analysis-and-inference
#7
Giorgos Minas, David A Rand
In order to analyse large complex stochastic dynamical models such as those studied in systems biology there is currently a great need for both analytical tools and also algorithms for accurate and fast simulation and estimation. We present a new stochastic approximation of biological oscillators that addresses these needs. Our method, called phase-corrected LNA (pcLNA) overcomes the main limitations of the standard Linear Noise Approximation (LNA) to remain uniformly accurate for long times, still maintaining the speed and analytically tractability of the LNA...
July 24, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28742038/understanding-symmetric-smoothing-filters-a-gaussian-mixture-model-perspective
#8
Stanley H Chan, Todd Zickler, Yue M Lu
Many patch-based image denoising algorithms can be formulated as applying a smoothing filter to the noisy image. Expressed as matrices, the smoothing filters must be row normalized so that each row sums to unity. Surprisingly, if we apply a column normalization before the row normalization, the performance of the smoothing filter can often be significantly improved. Prior works showed that such performance gain is related to the Sinkhorn-Knopp balancing algorithm, an iterative procedure that symmetrizes a row-stochastic matrix to a doublystochastic matrix...
July 24, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
https://www.readbyqxmd.com/read/28742018/dynamic-structure-of-locomotor-behavior-in-walking-fruit-flies
#9
Alexander Y Katsov, Limor Freifeld, Mark Horowitz, Seppe Kuehn, Thomas R Clandinin
The function of the brain is unlikely to be understood without an accurate description of its output, yet the nature of movement elements and their organization remains an open problem. Here, movement elements are identified from dynamics of walking in flies, using unbiased criteria. On one time scale, dynamics of walking are consistent over hundreds of milliseconds, allowing elementary features to be defined. Over longer periods, walking is well described by a stochastic process composed of these elementary features, and a generative model of this process reproduces individual behavior sequences accurately over seconds or longer...
July 25, 2017: ELife
https://www.readbyqxmd.com/read/28741470/ecological-feedback-in-quorum-sensing-microbial-populations-can-induce-heterogeneous-production-of-autoinducers
#10
Matthias Bauer, Johannes Knebel, Matthias Lechner, Peter Pickl, Erwin Frey
Autoinducers are small signaling molecules that mediate intercellular communication in microbial populations and trigger coordinated gene expression via 'quorum sensing'. Elucidating the mechanisms that control autoinducer production is, thus, pertinent to understanding collective microbial behavior, such as virulence and bioluminescence. Recent experiments have shown a heterogeneous promoter activity of autoinducer synthase genes, suggesting that some of the isogenic cells in a population might produce autoinducers, whereas others might not...
July 25, 2017: ELife
https://www.readbyqxmd.com/read/28741178/continuum-and-discrete-approach-in-modeling-biofilm-development-and-structure-a-review
#11
M R Mattei, L Frunzo, B D'Acunto, Y Pechaud, F Pirozzi, G Esposito
The scientific community has recognized that almost 99% of the microbial life on earth is represented by biofilms. Considering the impacts of their sessile lifestyle on both natural and human activities, extensive experimental activity has been carried out to understand how biofilms grow and interact with the environment. Many mathematical models have also been developed to simulate and elucidate the main processes characterizing the biofilm growth. Two main mathematical approaches for biomass representation can be distinguished: continuum and discrete...
July 24, 2017: Journal of Mathematical Biology
https://www.readbyqxmd.com/read/28741177/birth-birth-death-processes-and-their-computable-transition-probabilities-with-biological-applications
#12
Lam Si Tung Ho, Jason Xu, Forrest W Crawford, Vladimir N Minin, Marc A Suchard
Birth-death processes track the size of a univariate population, but many biological systems involve interaction between populations, necessitating models for two or more populations simultaneously. A lack of efficient methods for evaluating finite-time transition probabilities of bivariate processes, however, has restricted statistical inference in these models. Researchers rely on computationally expensive methods such as matrix exponentiation or Monte Carlo approximation, restricting likelihood-based inference to small systems, or indirect methods such as approximate Bayesian computation...
July 24, 2017: Journal of Mathematical Biology
https://www.readbyqxmd.com/read/28740983/combining-epr-spectroscopy-and-x-ray-crystallography-to-elucidate-the-structure-and-dynamics-of-conformationally-constrained-spin-labels-in-t4-lysozyme-single-crystals
#13
Philipp Consentius, Ulrich Gohlke, Bernhard Loll, Claudia Alings, Udo Heinemann, Markus C Wahl, Thomas Risse
Electron paramagnetic resonance (EPR) spectroscopy in combination with site-directed spin labeling is used to investigate the structure and dynamics of conformationally constrained spin labels in T4 lysozyme single crystals. Within a single crystal, the oriented ensemble of spin bearing moieties results in a strong angle dependence of the EPR spectra. A quantitative description of the EPR spectra requires the determination of the unit cell orientation with respect to the sample tube and the orientation of the spin bearing moieties within the crystal lattice...
July 25, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28740089/effects-of-growth-rate-and-promoter-activity-on-single-cell-protein-expression
#14
Niclas Nordholt, Johan van Heerden, Remco Kort, Frank J Bruggeman
Protein expression in a single cell depends on its global physiological state. Moreover, genetically-identical cells exhibit variability (noise) in protein expression, arising from the stochastic nature of biochemical processes, cell growth and division. While it is well understood how cellular growth rate influences mean protein expression, little is known about the relationship between growth rate and noise in protein expression. Here we quantify this relationship in Bacillus subtilis by a novel combination of experiments and theory...
July 24, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28739674/essential-role-of-the-cytoplasmic-chemoreceptor-tlpt-in-the-de-novo-formation-of-chemosensory-complexes-in-rhodobacter-sphaeroides
#15
Christopher W Jones, Judith P Armitage
Bacterial chemosensory proteins form large hexagonal arrays. Several key feature of chemotactic signalling depend on these large arrays, namely cooperativity between receptors, sensitivity, integration of different signals and adaptation. The best studied arrays are the membrane associated arrays found in most bacteria. Rhodobacter sphaeroides has two spatially distinct chemosensory arrays, one transmembrane and the other cytoplasmic. These two arrays work together to control a single flagellum. Deletion of one of the soluble chemoreceptors, TlpT, results in the loss of formation of the cytoplasmic array...
July 24, 2017: Journal of Bacteriology
https://www.readbyqxmd.com/read/28739136/coordinated-tracking-of-linear-multiagent-systems-with-input-saturation-and-stochastic-disturbances
#16
Qingling Wang, Changyin Sun
This paper addresses the coordinated tracking problem for linear multiagent systems with input saturation and stochastic disturbances. The objective is to construct a class of tracking control laws that achieve consensus tracking in the absence of disturbances, while guaranteeing a bounded variance of the state difference between the follower agent and the leader in the present of disturbances, under the assumptions that each agent is asymptotically null controllable with bounded controls (ANCBC) and the network is connected...
July 21, 2017: ISA Transactions
https://www.readbyqxmd.com/read/28738774/advanced-methods-for-analysis-of-testosterone
#17
Livia Alexandra Gugoasa, Raluca Ioana Stefan-van Staden
Testosterone is the principal endogenous androgenic-anabolic steroid in humans. The levels of testosterone in the human body are correlated with many hormonal disorders (hypogonadism, impotence, etc) mostly in men, and with many types of diseases such as: prostate cancer, metabolic syndrome, obesity, cardiovascular diseases and so on. Testosterone is extensively used among sportsmen willing to increase strength, aggressiveness, and recovery; making it the most commonly reported substance in steroid abuse. Fast, easy and cheap methods for the evaluation of testosterone are extremely needed in clinics and hospitals...
July 24, 2017: Current Medicinal Chemistry
https://www.readbyqxmd.com/read/28738457/-survey-of-economic-burden-of-hepatitis-b-related-diseases-in-12-areas-in-china
#18
Q S Ma, S Liang, H W Xiao, S X Zhang, G H Zhuang, Y H Zou, H Z Tan, J C Liu, Y H Zhang, A Q Xu, L Zhang, X X Feng, D S Hu, F Z Wang, F Q Cui, X F Liang
Objective: Less surveys on the economic burden of hepatitis B (HB)-related diseases have been conducted in China, so the socioeconomic harm caused by the diseases is not clear and the key parameters for economic evaluation of hepatitis B prevention and treatment are lacking. This study aimed to analyze the direct, indirect and intangible expenditures of hospitalized patients with HB-related diseases during hospitalization and during a year in different areas of China. Methods: The hospitals for infectious diseases and the large general hospitals in 12 areas in China were selected in the study...
July 10, 2017: Zhonghua Liu Xing Bing Xue za Zhi, Zhonghua Liuxingbingxue Zazhi
https://www.readbyqxmd.com/read/28738137/public-health-and-economic-consequences-of-vaccine-hesitancy-for-measles-in-the-united-states
#19
Nathan C Lo, Peter J Hotez
Importance: Routine childhood vaccination is declining in some regions of the United States due to vaccine hesitancy, which risks the resurgence of many infectious diseases with public health and economic consequences. There are ongoing policy debates on the state and national level, including legislation around nonmedical (personal-belief) exemptions for childhood vaccination and possibly a special government commission on vaccine safety, which may affect vaccine coverage. Objective: To estimate the number of measles cases in US children and the associated economic costs under scenarios of different levels of vaccine hesitancy, using the case example of measles, mumps, and rubella (MMR) vaccination and measles...
July 24, 2017: JAMA Pediatrics
https://www.readbyqxmd.com/read/28736847/reproductive-plasticity-and-landscape-heterogeneity-benefit-a-ground-nesting-bird-in-a-fire-prone-ecosystem
#20
J Matthew Carroll, Torre J Hovick, Craig A Davis, R Dwayne Elmore, Samuel D Fuhlendorf
Disturbance is critical for the conservation of rangeland ecosystems worldwide and many of these systems are fire dependent. Although it is well established that restoring fire as an ecological process can lead to increased biodiversity in grasslands and shrublands, the underlying mechanisms driving community patterns are poorly understood for fauna in fire-prone landscapes. Much of this uncertainty stems from the paucity of studies that examine the effects of fire at scales relevant to organism life histories...
July 24, 2017: Ecological Applications: a Publication of the Ecological Society of America
keyword
keyword
14339
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"