keyword
MENU ▼
Read by QxMD icon Read
search

Theory of simulation

keyword
https://www.readbyqxmd.com/read/28231324/a-framework-for-analyzing-contagion-in-assortative-banking-networks
#1
Thomas R Hurd, James P Gleeson, Sergey Melnik
We introduce a probabilistic framework that represents stylized banking networks with the aim of predicting the size of contagion events. Most previous work on random financial networks assumes independent connections between banks, whereas our framework explicitly allows for (dis)assortative edge probabilities (i.e., a tendency for small banks to link to large banks). We analyze default cascades triggered by shocking the network and find that the cascade can be understood as an explicit iterated mapping on a set of edge probabilities that converges to a fixed point...
2017: PloS One
https://www.readbyqxmd.com/read/28230763/an-improved-azimuth-angle-estimation-method-with-a-single-acoustic-vector-sensor-based-on-an-active-sonar-detection-system
#2
Anbang Zhao, Lin Ma, Xuefei Ma, Juan Hui
In this paper, an improved azimuth angle estimation method with a single acoustic vector sensor (AVS) is proposed based on matched filtering theory. The proposed method is mainly applied in an active sonar detection system. According to the conventional passive method based on complex acoustic intensity measurement, the mathematical and physical model of this proposed method is described in detail. The computer simulation and lake experiments results indicate that this method can realize the azimuth angle estimation with high precision by using only a single AVS...
February 20, 2017: Sensors
https://www.readbyqxmd.com/read/28230387/a-computer-adaptive-testing-version-of-the-addiction-severity-index-multimedia-version-asi-mv-the-addiction-severity-cat
#3
Stephen F Butler, Ryan A Black, Stacey A McCaffrey, Jessica Ainscough, Ann M Doucette
The purpose of this study was to develop and validate a computer adaptive testing (CAT) version of the Addiction Severity Index-Multimedia Version (ASI-MV), the Addiction Severity CAT. This goal was accomplished in 4 steps. First, new candidate items for Addiction Severity CAT domains were evaluated after brainstorming sessions with experts in substance abuse treatment. Next, this new item bank was psychometrically evaluated on a large nonclinical (n = 4,419) and substance abuse treatment (n = 845) sample. Based on these results, final items were selected and calibrated for the creation of the Addiction Severity CAT algorithms...
February 23, 2017: Psychology of Addictive Behaviors: Journal of the Society of Psychologists in Addictive Behaviors
https://www.readbyqxmd.com/read/28229338/investigation-of-the-encapsulation-of-metal-cations-cu-2-zn-2-ca-2-and-ba-2-by-the-dipeptide-phe-phe-using-natural-bond-orbital-theory-and-molecular-dynamics-simulation
#4
Snehasis Bhunia, Ajeet Singh, Animesh K Ojha
Complexes of the dipeptide phenylalanine-phenylalanine (Phe-Phe) with divalent metal cations (Cu(2+), Zn(2+), Ca(2+) and Ba(2+)) were studied at the B3LYP and MP2 levels of theory with the basis sets 6-311++G(d,p) and 6-31 + G(d) in the gas phase. The relative energies of these complexes indicated that cation-π bidentate/tridentate conformations are more favourable than other conformations with uncoordinated rings. These findings were confirmed by the calculated values of thermodynamic parameters such as the Gibbs free energy...
March 2017: Journal of Molecular Modeling
https://www.readbyqxmd.com/read/28228016/island-nucleation-and-growth-with-anomalous-diffusion-in-one-dimension
#5
Ehsan H Sabbar, Jacques G Amar
Recently a general rate-equation (RE) theory of submonolayer island nucleation and growth was developed [J. G. Amar and M. Semaan, Phys. Rev. E 93, 062805 (2016)] which takes into account the critical island-size i, island fractal dimension df, substrate dimension d, and diffusion exponent μ, and good agreement with simulations was found for the case of irreversible growth corresponding to a critical island-size i=1 with d = 2. Here we present the results of simulations carried out in 1D (corresponding to d = 1) of island nucleation and growth with anomalous diffusion which were carried out for both the case of superdiffusion (μ>1) and subdiffusion (μ<1)...
February 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28226648/a-multivariate-time-frequency-approach-for-tracking-qt-variability-changes-unrelated-to-heart-rate-variability
#6
Michele Orini, Peter Taggart, Pier D Lambiase, Michele Orini, Peter Taggart, Pier D Lambiase, Peter Taggart, Michele Orini, Pier D Lambiase
The beat-to-beat variability of the QT interval (QTV) is a marker of ventricular repolarization (VR) dynamics and it has been suggested as an index of sympathetic ventricular outflow and cardiac instability. However, QTV is also affected by RR (or heart rate) variability (RRV), and QTV due to RRV may reduce QTV specificity as a VR marker. Therefore, it would be desirable to separate QTV due to VR dynamics from QTV due to RRV. To do that, previous work has mainly focused on heart rate corrections or time-invariant autoregressive models...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226468/from-good-intentions-to-healthy-habits-towards-integrated-computational-models-of-goal-striving-and-habit-formation
#7
Peter Pirolli, Peter Pirolli, Peter Pirolli
Computational models were developed in the ACT-R neurocognitive architecture to address some aspects of the dynamics of behavior change. The simulations aim to address the day-to-day goal achievement data available from mobile health systems. The models refine current psychological theories of self-efficacy, intended effort, and habit formation, and provide an account for the mechanisms by which goal personalization, implementation intentions, and remindings work.
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226450/identifying-epileptic-source-location-and-extent-an-iterative-sparse-electromagnetic-source-imaging-algorithm
#8
Abbas Sohrabpour, Yunfeng Lu, Gregory Worrell, Bin He, Abbas Sohrabpour, Yunfeng Lu, Gregory Worrell, Bin He, Abbas Sohrabpour, Yunfeng Lu, Gregory Worrell, Bin He
In this paper we have introduced a novel electromagnetic source imaging (ESI) technique and demonstrated its validity and excellent performance in imaging the location and extent of underlying epileptic sources in patients suffering from focal epilepsy. The proposed algorithm employs ideas from sparse signal processing literature and convex optimization theories to improve source imaging results obtained from scalp-recorded electroencephalogram (EEG). EEG source imaging results generally use subjective methods to determine the extent of the underlying brain activity...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28225838/-mental-simulation-in-frontotemporal-dementia
#9
Daniel G Politis, Wanda Y Rubinstein, María E Tabernero
: There is a common network for perception and execution of actions necessary for the acquisition of Theory of Mind, and the mirror neuron system could be the neural substrate. OBJECTIVE: To study the presence of apraxia and their relationship to Theory of Mind in patients with behavioral variant of Frontotemporal Dementia. METHODS: 24 patients were assessed, and the cognitive praxis assessment battery and theory of mind were administered...
May 2016: Vertex: Revista Argentina de Psiquiatriá
https://www.readbyqxmd.com/read/28225571/balancing-selection-maintains-sex-determining-alleles-in-multiple-locus-complementary-sex-determination
#10
Jerome J Weis, Paul J Ode, George E Heimpel
Hymenopteran species in which sex is determined through a haplo-diploid mechanism known as complementary sex determination (CSD) are vulnerable to a unique form of inbreeding depression. Diploids heterozygous at one or more CSD loci develop into females but diploids homozygous at all loci develop into diploid males, which are generally sterile or inviable. Species with multiple polymorphic CSD loci (ml-CSD) may have lower rates of diploid male production than species with a single CSD locus (sl-CSD), but it is not clear if polymorphism is consistently maintained at all loci...
February 22, 2017: Evolution; International Journal of Organic Evolution
https://www.readbyqxmd.com/read/28225251/silicone-infused-anti-smudge-nanocoatings
#11
Heng Hu, Jian Wang, Yu Wang, Emily Gee, Guojun Liu
A polyurethane-based NP-GLIDE coating that bears on its surface and in its interior nano-pools of a grafted liquid ingredient for dewetting enablement is obtained from casting and curing a film comprising a triisocyanate, a polyol (P1), and a graft (g) copolymer of P1 and poly(dimethyl siloxane) (P1-g-PDMS). A silicone-infused NP-GLIDE (SINP-GLIDE) PU coating is obtained from co-casting the NP-GLIDE precursors with a free silicone oil (SO) or SO mixture (SOs). This paper reports the preparation of the novel SINP-GLIDE coatings and discusses the effect of changing the amount and type of the infused SO as well as the coating formation conditions on their optical clarity...
February 22, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28225121/the-local-electronic-properties-of-individual-pt-atoms-adsorbed-on-tio2-110-studied-by-kelvin-probe-force-microscopy-and-first-principles-simulations
#12
Ayhan Yurtsever, Delia Fernández-Torre, Jo Onoda, Masayuki Abe, Seizo Morita, Yoshiaki Sugimoto, Rubén Pérez
Noble metal nanostructures dispersed on metal oxide surfaces have applications in diverse areas such as catalysis, chemical sensing, and energy harvesting. Their reactivity, chemical selectivity, stability, and light absorption properties are controlled by the interactions at the metal/oxide interface. Single-atom metal adsorbates on the rutile TiO2(110)-(1 × 1) surface have become a paradigmatic model to characterize those interactions and to understand the unique electronic properties of these supported nanostructures...
February 22, 2017: Nanoscale
https://www.readbyqxmd.com/read/28223518/integrated-view-of-internal-friction-in-unfolded-proteins-from-single-molecule-fret-contact-quenching-theory-and-simulations
#13
Andrea Soranno, Andrea Holla, Fabian Dingfelder, Daniel Nettels, Dmitrii E Makarov, Benjamin Schuler
Internal friction is an important contribution to protein dynamics at all stages along the folding reaction. Even in unfolded and intrinsically disordered proteins, internal friction has a large influence, as demonstrated with several experimental techniques and in simulations. However, these methods probe different facets of internal friction and have been applied to disparate molecular systems, raising questions regarding the compatibility of the results. To obtain an integrated view, we apply here the combination of two complementary experimental techniques, simulations, and theory to the same system: unfolded protein L...
February 21, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28223264/applying-computerized-adaptive-testing-to-the-four-dimensional-symptom-questionnaire-4dsq-a-simulation-study
#14
Tessa Magnée, Derek P de Beurs, Berend Terluin, Peter F Verhaak
BACKGROUND: Efficient screening questionnaires are useful in general practice. Computerized adaptive testing (CAT) is a method to improve the efficiency of questionnaires, as only the items that are particularly informative for a certain responder are dynamically selected. OBJECTIVE: The objective of this study was to test whether CAT could improve the efficiency of the Four-Dimensional Symptom Questionnaire (4DSQ), a frequently used self-report questionnaire designed to assess common psychosocial problems in general practice...
February 21, 2017: JMIR Mental Health
https://www.readbyqxmd.com/read/28223007/global-dissipativity-analysis-for-delayed-quaternion-valued-neural-networks
#15
Zhengwen Tu, Jinde Cao, Ahmed Alsaedi, Tasawar Hayat
The problem of global dissipativity analysis for quaternion-valued neural networks (QVNNs) with time-varying delays is firstly investigated in this paper. The QVNN is studied as a single entirety without any decomposition. Several algebraic conditions ensuring the global dissipativity and globally exponential dissipativity for QVNNs are derived by employing Lyapunov theory and some analytic techniques. Furthermore, the positive invariant sets, globally attractive sets and globally exponentially attractive sets are figured out as well...
February 4, 2017: Neural Networks: the Official Journal of the International Neural Network Society
https://www.readbyqxmd.com/read/28222598/drastic-compensation-of-the-electronic-and-solvation-effects-on-the-atp-hydrolysis-revealed-through-a-large-scale-qm-mm-simulations-combined-with-a-theory-of-solutions
#16
Hideaki Takahashi, Satoru Umino, Yuji Miki, Ryosuke Ishizuka, Shu Maeda, Akihiro Morita, Makoto Suzuki, Nobuyuki Matubayasi
Hydrolysis of adenosine triphosphate (ATP) is the "energy source" for a variety of biochemical processes. In the present work, we address key features of ATP hydrolysis: the relatively moderate value (about -10 kcal/mol) of the standard free energy ΔGhyd of reaction and the insensitivity of ΔGhyd to the number of excess electrons on ATP. We conducted quantum mechanical/molecular mechanical (QM/MM) simulation combined with the energy-representation theory of solutions to analyze the electronic-state and solvation contributions to ΔGhyd...
February 21, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28222198/algorithmic-design-of-a-noise-resistant-and-efficient-closed-loop-deep-brain-stimulation-system-a-computational-approach
#17
Sofia D Karamintziou, Ana Luísa Custódio, Brigitte Piallat, Mircea Polosan, Stéphan Chabardès, Pantelis G Stathis, George A Tagaris, Damianos E Sakas, Georgia E Polychronaki, George L Tsirogiannis, Olivier David, Konstantina S Nikita
Advances in the field of closed-loop neuromodulation call for analysis and modeling approaches capable of confronting challenges related to the complex neuronal response to stimulation and the presence of strong internal and measurement noise in neural recordings. Here we elaborate on the algorithmic aspects of a noise-resistant closed-loop subthalamic nucleus deep brain stimulation system for advanced Parkinson's disease and treatment-refractory obsessive-compulsive disorder, ensuring remarkable performance in terms of both efficiency and selectivity of stimulation, as well as in terms of computational speed...
2017: PloS One
https://www.readbyqxmd.com/read/28221348/self-assembly-of-nanoparticles-into-biomimetic-capsid-like-nanoshells
#18
Ming Yang, Henry Chan, Gongpu Zhao, Joong Hwan Bahng, Peijun Zhang, Petr Král, Nicholas A Kotov
Nanoscale compartments are one of the foundational elements of living systems. Capsids, carboxysomes, exosomes, vacuoles and other nanoshells easily self-assemble from biomolecules such as lipids or proteins, but not from inorganic nanomaterials because of difficulties with the replication of spherical tiling. Here we show that stabilizer-free polydispersed inorganic nanoparticles (NPs) can spontaneously organize into porous nanoshells. The association of water-soluble CdS NPs into self-limited spherical capsules is the result of scale-modified electrostatic, dispersion and other colloidal forces...
March 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28220629/binding-of-hydroxylated-polybrominated-diphenyl-ethers-with-human-serum-albumin-spectroscopic-characterization-and-molecular-modeling
#19
Lulu Yang, Wu Yang, Zhiwei Wu, Zhongsheng Yi
Three hydroxylated polybrominated diphenyl ethers (OH-PBDEs), 3-OH-BDE-47, 5-OH-BDE-47, and 6-OH-BDE-47, were selected to investigate the interactions between OH-PBDEs with human serum albumin (HSA) under physiological conditions. The observed fluorescence quenching can be attributed to the formation of complexes between HSA and OH-PBDEs. The thermodynamic parameters at different temperatures indicate that the binding was caused by hydrophobic forces and hydrogen bonds. Molecular modeling and three-dimensional fluorescence spectrum showed conformational and microenvironmental changes in HSA...
February 21, 2017: Luminescence: the Journal of Biological and Chemical Luminescence
https://www.readbyqxmd.com/read/28220096/investigating-a-weakly-informative-prior-for-item-scale-hyperparameters-in-hierarchical-3pno-irt-models
#20
Yanyan Sheng
The half-t family has been suggested for the scale hyperparameter in Bayesian hierarchical modeling. Two parameters define a half-t distribution: the scale s and the degree-of-freedom ν. When s is set at a finite value that is slightly larger than the actual standard deviation of the parameters, the half-t prior density can be vaguely informative. This paper focused on such densities, and applied them to the hierarchical three-parameter item response theory (IRT) model. Monte Carlo simulations were carried out to investigate the performance of such specifications in parameter recovery and model comparisons under situations where the actual variability of item parameters varied, and results suggest that the half-t family does offer advantages over the commonly adopted uniform or inverse-gamma prior density by allowing the variability for item parameters to be either very small or large...
2017: Frontiers in Psychology
keyword
keyword
10051
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"