Relevant bibliographies by topics / Space-time in RS Model

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
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Academic literature on the topic 'Space-time in RS Model'

Author: Grafiati
Published: 7 September 2023

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Journal articles on the topic "Space-time in RS Model"

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Jia, Xiaoxu, Ming'an Shao, and Xiaorong Wei. "State-space prediction of soil respiration time series in temperate, semi-arid grassland in northern China." Soil Research 50, no. 4 (2012): 293. http://dx.doi.org/10.1071/sr12068.

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The prediction of soil respiration (Rs) has traditionally been studied using classical statistical methods. These methods do not consider temporal/spatial coordinates and assume independence between samples. The aim was to determine the primary factors influencing Rs and to develop a state-space model able to predict soil respiration. This study was conducted during one growing season, from July to October 2010, in temperate, semi-arid grassland. Data were collected for Rs, air temperature, soil surface temperature, soil temperature at a depth of 5 cm, soil moisture, air pressure, and relative humidity. Additionally, a novel autoregressive state-space method was used to simulate and predict Rs based on primary factors, and the quality of prediction was compared with the quality of prediction using classical statistics. Soil surface temperature and soil moisture were identified as primary factors affecting Rs. The state-space model that included soil surface temperature was a simple but effective model, accounting for 95% of the variation in Rs. The classical statistical models, however, represented only 39–69% of the variation in Rs. Furthermore, the quality of prediction of the state-space models was consistently much better than the quality from the classical statistical methods. State-space analysis is an effective tool for studying the temporal relationships between soil respiration and influencing factors. Additionally, the state-space method is recommended for predicting soil respiration using soil surface temperature in semi-arid grassland in northern China.
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Fiscaletti, D., and A. Sorli. "Quantum Relativity: Variable Energy Density of Quantum Vacuum as the Origin of Mass, Gravity and the Quantum Behaviour." Ukrainian Journal of Physics 63, no. 7 (August 2, 2018): 623. http://dx.doi.org/10.15407/ujpe63.7.623.

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In Quantum Relativity, time and space are separated. Time is the numerical order of material changes, and space is the medium, in which these changes take place. Space has the origin in a three-dimensional quantum vacuum defined by fluctuations of the energy density corresponding to elementary RS (reduction state) processes of creation/annihilation of elementary quanta. Quantum Relativity provides a unifying approach to special relativity, general relativity, and quantum mechanics. Each physical object from the micro- to the macroscale can be derived from an opportune diminishing of the quantum vacuum energy density. In particular, the variable energy density of space in Quantum Relativity corresponds to the curvature of space in general relativity. In quantum theory, the behavior of each subatomic particle follows from opportune elementary RS processes of creation/annihilation of quanta guided by a quantum potential of the vacuum. Finally, the perspectives of this model regarding the view of gravity and quantum as two aspects of the same coin and the electroweak scale are analyzed.
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PENNA, T. J. P., P. M. C. de OLIVEIRA, J. J. ARENZON, R. M. C. de ALMEIDA, and J. R. IGLESIAS. "CONVERGENCE TIME ON THE RS MODEL FOR NEURAL NETWORKS." International Journal of Modern Physics C 02, no. 03 (September 1991): 711–17. http://dx.doi.org/10.1142/s0129183191000950.

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Convergence times and the corresponding dispersions have been studied numerically as parameters to measure the efficiency of neural network models. These quantities are also supposed to be related to the number of spurious states for each configuration of stored patterns. In this work we measure these quantities for a recent multineuron interaction model presenting an enhanced performance compared to other traditional schemes.
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Huang, Xiaohui, Jiabao Li, Jining Yan, and Lizhe Wang. "An adaptive geographic meshing and coding method for remote sensing data." IOP Conference Series: Earth and Environmental Science 1004, no. 1 (March 1, 2022): 012006. http://dx.doi.org/10.1088/1755-1315/1004/1/012006.

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Abstract Spatial indexing techniques, inherently data structures, are generally used in portals opened by institutions or organizations to efficiently filter RS images according to their spatial extent, thus providing researchers with fast Remote Sensing (RS) image data discovery ability. Specifically, space-based spatial indexing approaches are widely adopted to index RS images in distributed environments by mapping RS images in two-dimensional space into several one-dimensional spatial codes. However, current spatial indexing approaches still suffer from the boundary objects problem, which leads to multiple spatial codes for a boundary-crossing RS image and thus alleviates the performance of spatial indexes built on top of these spatial codes. To solve this problem, we propose an adaptive geographic meshing and coding method (AGMD) by combining the famous subdivision model GeoSOT and XZ-ordering to generate only one spatial code for RS images with different spatial widths. Then, we implement our proposed method with a unified big data programming model, (i.e., Apache Beam), to enable its execution in various distributed computing engines (e.g., MapReduce, and Apache Spark, etc.) in distributed environments. Finally, we conduct a series of experiments on real datasets, the archived Landsat metadata collection in level 2. The results show that the proposed AGMD method performs well on metrics, including the following aspects: the effectiveness of the storage overhead and the time cost are up to 359.7% and 58.02 %, respectively.
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Arendse, Nikki, Adriano Agnello, and Radosław J. Wojtak. "Low-redshift measurement of the sound horizon through gravitational time-delays." Astronomy & Astrophysics 632 (December 2019): A91. http://dx.doi.org/10.1051/0004-6361/201935972.

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Context. The matter sound horizon can be infered from the cosmic microwave background within the Standard Model. Independent direct measurements of the sound horizon are then a probe of possible deviations from the Standard Model. Aims. We aim at measuring the sound horizon rs from low-redshift indicators, which are completely independent of CMB inference. Methods. We used the measured product H(z)rs from baryon acoustic oscillations (BAO) together with supernovae Ia to constrain H(z)/H0 and time-delay lenses analysed by the H0LiCOW collaboration to anchor cosmological distances (∝ H0−1). Additionally, we investigated the influence of adding a sample of quasars with higher redshift with standardisable UV-Xray luminosity distances. We adopted polynomial expansions in H(z) or in comoving distances so that our inference was completely independent of any cosmological model on which the expansion history might be based. Our measurements are independent of Cepheids and systematics from peculiar motions to within percent-level accuracy. Results. The inferred sound horizon rs varies between (133 ± 8) Mpc and (138 ± 5) Mpc across different models. The discrepancy with CMB measurements is robust against model choice. Statistical uncertainties are comparable to systematics. Conclusions. The combination of time-delay lenses, supernovae, and BAO yields a distance ladder that is independent of cosmology (and of Cepheid calibration) and a measurement of rs that is independent of the CMB. These cosmographic measurements are then a competitive test of the Standard Model, regardless of the hypotheses on which the cosmology is based.
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Weiß, Christian H. "Regime-Switching Discrete ARMA Models for Categorical Time Series." Entropy 22, no. 4 (April 17, 2020): 458. http://dx.doi.org/10.3390/e22040458.

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For the modeling of categorical time series, both nominal or ordinal time series, an extension of the basic discrete autoregressive moving-average (ARMA) models is proposed. It uses an observation-driven regime-switching mechanism, leading to the family of RS-DARMA models. After having discussed the stochastic properties of RS-DARMA models in general, we focus on the particular case of the first-order RS-DAR model. This RS-DAR ( 1 ) model constitutes a parsimoniously parameterized type of Markov chain, which has an easy-to-interpret data-generating mechanism and may also handle negative forms of serial dependence. Approaches for model fitting are elaborated on, and they are illustrated by two real-data examples: the modeling of a nominal sequence from biology, and of an ordinal time series regarding cloudiness. For future research, one might use the RS-DAR ( 1 ) model for constructing parsimonious advanced models, and one might adapt techniques for smoother regime transitions.
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Ribeiro, Valério A. R. M., Michael F. Bode, and Robert Williams. "Modelling the Late-time Hubble Space Telescope Imaging of the Outburst of the Recurrent Nova RS Ophiuchi (2006)." Proceedings of the International Astronomical Union 8, S290 (August 2012): 137–40. http://dx.doi.org/10.1017/s1743921312019382.

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AbstractThe nebular remnant of RS Ophiuchi was modelled using combined HST/ACS imaging and ground-based spectroscopy on day 155 after outburst as a two component bipolar expansion with a low velocity innermost hour-glass over density and a more extended high velocity dumbbell structure. The model was evolved to a much later date, day 455 after outburst, when second epoch HST images were secured. However, due to the lack of simultaneous ground-based spectroscopy the evolved model was much harder to constrain. One suggestion put forward was that the dumbbell structure expanded linearly while the inner hour-glass showed signs of deceleration. Archival data in the form of ground-based spectroscopy on day 415 were subsequently obtained. These new data suggest indeed that a non-linear expansion of the system occurred.
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Gaztañaga, Enrique. "The mass of our observable Universe." Monthly Notices of the Royal Astronomical Society: Letters 521, no. 1 (February 14, 2023): L59—L63. http://dx.doi.org/10.1093/mnrasl/slad015.

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ABSTRACT The standard cosmological model Lambda Cold Dark Matter (LCDM) assumes a global expanding space–time of infinite extent around us. But such idea is inconsistent with the observed cosmic acceleration unless we advocate for the existence of a mysterious dark energy (DE) or a cosmological constant (Λ). Here, we argue instead that our Universe has a very large but finite regular mass M, without the need to invoke DE or Λ. A system with a finite mass M has a finite gravitational radius rS = 2GM. When M is contained within rS, this is a black hole (BH). Nothing from inside can escape outside rS, which becomes a boundary for the inside dynamics. In the limit where there is nothing else outside, the inside corresponds then to a local isolated universe. Such boundary condition is equivalent to a Λ term: $\Lambda =3/r_\mathrm{ S}^2$. We can therefore interpret cosmic acceleration as a measurement of the gravitational radius of our Universe, rS, with a mass M ≃ 6 × 1022 M⊙. Such BH Universe is observationally very similar to the LCDM, except for the lack of the largest scale perturbations, which are bounded by rS.
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Gao, Shi-Jie, Ya-Tian Li, and Tian-Wen Geng. "Deep Reinforcement Learning-Based Relay Selection Algorithm in Free-Space Optical Cooperative Communications." Applied Sciences 12, no. 10 (May 11, 2022): 4881. http://dx.doi.org/10.3390/app12104881.

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Relay-aided free-space optical (FSO) communication systems have the ability of mitigating the adverse effects of link disruption by dividing a long link into several short links. In order to solve the relay selection (RS) problem in a decode and forward (DF) relay-aided FSO system, we model the relay selection scheme as a Markov decision process (MDP). Based on a dueling deep Q-network (DQN), the DQN-RS algorithm is proposed, which aims at maximizing the average capacity. Different from relevant works, the switching loss between relay nodes is considered. Thanks to the advantage of maximizing cumulative rewards by deep reinforcement learning (DRL), our simulation results demonstrate that the proposed DQN-RS algorithm outperforms the traditional greedy method.
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Lázaro, C., and M. J. Arévalo. "Time-Resolved Spectroscopy of Short Period RS CVn Systems." International Astronomical Union Colloquium 137 (1993): 392–94. http://dx.doi.org/10.1017/s0252921100018145.

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AbstractWe have initiated a programme of spectroscopic observations of RS CVn short-period group, with orbital phase resolution. The systems of this group are all eclipsing binaries with both components at the Main Sequence, and most of them have similar spectral type components. The high rotational velocities and their short orbital periods (less than 1 day) hinder the spectroscopic study of these stars. We presents the first results yielded by Hα line observations of the systems XY UMa and WY Cnc. Both systems were observed during 1991 with reasonably wide orbital phase coverage. The analysis of the spectra is made by comparison with a binary model, constructed from the observed spectra of normal stars of the same spectral type as the RS CVn system components. The model accounts for the partial contribution of each component at any orbital phase within eclipses.
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Dissertations / Theses on the topic "Space-time in RS Model"

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Langford, William P. "A space-time flow optimization model for neighborhood evacuation." Thesis, Monterey, California : Naval Postgraduate School, 2010. http://edocs.nps.edu/npspubs/scholarly/theses/2010/Mar/10Mar%5FLangford.pdf.

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Thesis (M.S. in Operations Research)--Naval Postgraduate School, March 2010.
Thesis Advisor: Alderson, David L. Second Reader: Church, Richard L. "March 2010." Author(s) subject terms: Evacuation, Network, Flow Optimization, Space-Time network. Includes bibliographical references (p. 41-42). Also available in print.
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Hone, David M. "Time and space resolution and mixed layer model accuracy." Monterey, California. Naval Postgraduate School, 1997. http://hdl.handle.net/10945/9080.

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The oceanic turbulent boundary layer is a critical region to understand for oceanic and atmospheric prediction. This thesis answers two fundamental questions: (1) what is the response of the ocean mixed layer system to transient forcing at the air sea surface? (2) what is the necessary time and space resolution in an ocean mixed layer model to resolve important transient responses? Beginning with replication of de Szoeke and Rhines' work, additional physical processes were added to include more realistic viscous dissipation and anisotropy in the three-dimensional turbulent kinetic energy (TKE) budget. These refinements resulted in modification of de Szoeke and Rhines' findings. Firstly, TKE unsteadiness is important for a minimum of 10 to the 5th power seconds. Secondly, viscous dissipation should not be approximated as simply proportional to shear production. Thirdly, entrainment shear production remains significant for a minimum of one pendulum-day. The required temporal model resolution is dependent on the phenomena to be studied. This study focused on the diurnal, synoptic, and annual cycles, which the one-hour time step of the Naval Postgraduate School model adequately resolves. The study of spatial resolution showed unexpectedly that model skill was comparable for 1 m, 10 m and even 20 m vertical grid spacing
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Ehlers, Ricardo Sandes. "Bayesian model discrimination for time series and state space models." Thesis, University of Surrey, 2002. http://epubs.surrey.ac.uk/843599/.

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In this thesis, a Bayesian approach is adopted to handle parameter estimation and model uncertainty in autoregressive moving average (ARMA) time series models and dynamic linear models (DLM). Bayesian model uncertainty is handled in a parametric fashion through the use of posterior model probabilities computed via Markov chain Monte Carlo (MCMC) simulation techniques. Attention is focused on reversible jump Markov chain Monte Carlo (RJMCMC) samplers, which can move between models of different dimensions, to address the problem of model order uncertainty and strategies for proposing efficient sampling schemes in autoregressive moving average time series models and dynamic linear models are developed. The general problem of assessing convergence of the sampler in a dimension-changing context is addressed by computing estimates of the probabilities of moving to higher and lower dimensional spaces. Graphical and numerical techniques are used to compare different updating schemes. The methodology is illustrated by applying it to both simulated and real data sets and the results for the Bayesian model selection and parameter estimation procedures are compared with the classical model selection criteria and maximum likelihood estimation.
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Mellor, Dale. "The modified turning bands (MTB) model for space-time rainfall." Thesis, University of Newcastle Upon Tyne, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357808.

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Granholm, George Richard 1976. "Near-real time atmospheric density model correction using space catalog data." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/44899.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2000.
Includes bibliographical references (p. 179-184).
Several theories have been presented in regard to creating a neutral density model that is corrected or calibrated in near-real time using data from space catalogs. These theories are usually limited to a small number of frequently tracked "calibration satellites" about which information such as mass and crosssectional area is known very accurately. This work, however, attempts to validate a methodology by which drag information from all available low-altitude space objects is used to update any given density model on a comprehensive basis. The basic update and prediction algorithms and a technique to estimate true ballistic factors are derived in detail. A full simulation capability is independently verified. The process is initially demonstrated using simulated range, azimuth, and elevation observations so that issues such as required number and types of calibration satellites, density of observations, and susceptibility to atmospheric conditions can be examined. Methods of forecasting the density correction models are also validated under different atmospheric conditions.
by George Richard Granholm.
S.M.
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Mukherjee, Smarajit. "Time- and Space-resolved Heat Transfer Model for Spark-Ignition Engines." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1517440404339384.

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Kotecha, Vinay. "Solitons on lattices and curved space-time." Thesis, Durham University, 2001. http://etheses.dur.ac.uk/3845/.

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This thesis is concerned with solitons (solutions of certain nonlinear partial differential equations) in certain cases when the underlying space is either a lattice or curved. Chapter 2 of the thesis is concerned with the outcome of collisions between a kink (a 1-dimensional soliton) and an antikink for certain topological discrete (TD) systems. The systems considered are the TD sine-Gordon and the TD ø(^4) For the TD sine-Gordon system it is found that the kink can support an internal shape mode which plays an important role during the collisions. In particular, this mode can be excited during collisions and this leads to spectacular resonance effects. The outcome of any particular collision has sensitive dependence on the initial conditions and could be either a trapped kink-antikink state, a "reflection" or a "transmission”. Such resonance effects are already known to exist for the conventional discrete ø(^4) system, and the TD ø(^4) system is no different, though the results for the two are not entirely similar. Chapter 3 considers the question of the existence of explicit travelling kink solutions for lattice systems. In particular, an expression for such a solution for the integrable lattice sine-Gordon system is derived. In Chapter 4, by reducing the Yang-Mills equations on the (2 + 2)-dimensional ultrahyperbolic space-time, an integrable Yang-Mills-Higgs system on (2 + 1) dimensional de Sitter space-time is derived. It represents the curved space-time version of the Bogomolny equations for monopoles on R(^3) . Using twister methods, various explicit solutions with gauge groups U(l) and SU(2) are constructed. A multi-solution SU(2) solution is also presented.
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Guadagnin, Fábio. "Identidades espaço-temporais em Terra de Areia/RS : um estudo sobre o tempo e a geografia." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/15274.

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A utilização do conceito de tempo como uma categoria de análise em Geografia não é tão rara quanto se imagina, mas tampouco é tão presente e reflexiva quanto se gostaria. Ainda mais raros são os trabalhos de pesquisa que incluem de maneira efetiva a dimensão espaçotemporal na análise geográfica. Esta pesquisa apresenta, portanto, uma discussão em torno de autores que analisam esta perspectiva, na tentativa de construir os conceitos de espaço-tempo, temporalidade (velocidade de transporte de matéria e informação) e identidade espaçotemporal, ao mesmo tempo em que tenta articulá-los ao universo conceitual da Geografia. Adicionalmente, esta pesquisa também tenta demonstrar uma possibilidade de uso efetivo destes conceitos na análise de um recorte espacial específico. O trabalho de campo experimental foi desenvolvido na cidade de Terra de Areia, no Litoral Norte do Rio Grande do Sul, onde diversos fluxos lentos e rápidos convivem proximamente, gerando conflitos temporais manifestados nos hábitos, gestos e sentimentos dos habitantes da localidade.
The use of the concept of time as a category of analysis in Geography is not as rare as we imagine, but neither is as reflexive or common as we would like it to be. Even more rare are the scientific works that include in an effective way the space-time dimension in geographical analysis. This research presents, therefore, a discussion about authors who discuss this perspective, in trying to build the concepts of space-time, temporality (matter and information transport speed) and spatial-temporal identity at the same time that tries to link them to the conceptual universe of Geography. Also, this research tries to demonstrate a possibility of effective use of these concepts in the analysis of a specific portion of space. The experimental field work was developed in the city of Terra de Areia, in the northern coast of Rio Grande do Sul/Brazil, where several flows with different speeds live closely, generating temporal conflicts manifested in habits, gestures and feelings of the inhabitants of the town.
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Boguta, Maria. "A New Space-Time Model for Interacting Agents in the Financial Market." Thesis, Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-3180.

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In this thesis we present a new space-time model of interacting agents in the financial market. It is a combination of the Curie-Weiss model and a model introduced by Järpe. We investigate properties such as the critical temperature and magnetization of the system. The distribution of the Hamiltonian function is obtained and a hypothesis test of independence is derived. The results are illustrated in an example based on real data.

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Parashkevov, Atanas. "Advances in space and time efficient model checking of finite state systems." Title page, contents and abstract only, 2002. http://web4.library.adelaide.edu.au/theses/09PH/09php223.pdf.

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Bibliography: leaves 211-220 This thesis examines automated formal verification techniques and their associated space and time implementation complexity when applied to finite state concurrent systems. The focus is on concurrent systems expressed in the Communicating Sequential Processes (CSP) framework. An approach to the compilation of CSP system descriptions into boolean formulae in the form of Ordered Binary Decision Diagrams (OBDD) is presented, further utilised by a basic algorithm that checks a refinement or equivalence relation between a pair of processes in any of the three CSP semantic models. The performance bottlenecks of the basic refinement checking algorithms are identified and addressed with the introduction of a number of novel techniques and algorithms. Algorithms described in this thesis are implemented in the Adelaide Tefinement Checking Tool.
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Books on the topic "Space-time in RS Model"

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Hone, David M. Time and space resolution and mixed layer model accuracy. Monterey, Calif: Naval Postgraduate School, 1997.

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A model of the universe: Space-time, probability, and decision. Oxford: Clarendon press, 1994.

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Shabetnik, Basil D. Fractal physics: Introduction to a new physical model. Kaunas, Lithuania: A. Gylys, 1994.

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Hagiwara, Junichiro. Time Series Analysis for the State-Space Model with R/Stan. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-0711-0.

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Language, space, and social relationships: A foundational cultural model in Polynesia. New York: Cambridge University Press, 2009.

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Cowan, Daniel A. Mind underlies spacetime: The axioms describing directly interconnected substance and the model that explains away finiteness. 3rd ed. San Mateo, Calif: Joseph Pub., 2002.

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Cowan, Daniel A. Mind underlies spacetime: The axioms describing the actual spacetime framework and the model that refutes finite action. 5th ed. San Mateo, Calif: Joseph Pub., 2005.

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Mind underlies spacetime: The axioms describing the actual spacetime framework and the model that refutes finite action. 4th ed. San Mateo, Calif: Joseph Pub., 2005.

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Cowan, Daniel A. Mind underlies spacetime: The axioms and verifying model for how connections form space and how sequenced focusing forms local time. 6th ed. San Mateo, Calif: Joseph Pub., 2006.

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Cowan, Daniel A. Mind underlies spacetime: The axioms and verifying model for how connections form space and how sequenced focusing forms local time. 7th ed. San Mateo, Calif: Joseph Pub., 2008.

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Book chapters on the topic "Space-time in RS Model"

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Chung, Eric, Yalchin Efendiev, and Thomas Y. Hou. "Space-time GMsFEM." In Multiscale Model Reduction, 213–28. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-20409-8_9.

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Kuijpers, Bart. "Space-Time Prism Model." In Encyclopedia of GIS, 1–7. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-23519-6_1599-1.

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Kuijpers, Bart. "Space-Time Prism Model." In Encyclopedia of GIS, 1926–32. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-17885-1_1599.

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Das, Suvra Sekhar, and Ramjee Prasad. "OTFS Signal Model." In Orthogonal Time Frequency Space Modulation, 89–102. New York: River Publishers, 2022. http://dx.doi.org/10.1201/9781003339021-3.

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Klincewicz, Michał. "Quality Space Model of Temporal Perception." In Multidisciplinary Aspects of Time and Time Perception, 230–45. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-21478-3_18.

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Zou, Xin-yao. "Time–Space Hybrid Markov Model." In Lecture Notes in Electrical Engineering, 633–40. Dordrecht: Springer Netherlands, 2011. http://dx.doi.org/10.1007/978-94-007-1839-5_67.

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Hagiwara, Junichiro. "State-Space Model." In Time Series Analysis for the State-Space Model with R/Stan, 59–68. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-0711-0_5.

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Gómez, Víctor. "The State Space Model." In Linear Time Series with MATLAB and OCTAVE, 281–304. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-20790-8_10.

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Pohl, Martin. "The Standard Model of matter and forces." In Particles, Fields, Space-Time, 173–220. Boca Raton : CRC Press, 2021.: CRC Press, 2020. http://dx.doi.org/10.1201/9780429331107-9.

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Gómez, Víctor. "The State Space Model." In Multivariate Time Series With Linear State Space Structure, 213–322. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-28599-3_4.

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Conference papers on the topic "Space-time in RS Model"

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Gao, Zhiqiang, Wei Gao, James R. Slusser, Xiaoling Pan, and Yingjun Ma. "The sensitivity of NPP to climate controls in northern China estimated by CLM model coupled with RS and GIS technology." In Third International Asia-Pacific Environmental Remote Sensing Remote Sensing of the Atmosphere, Ocean, Environment, and Space, edited by Xiaoling Pan, Wei Gao, Michael H. Glantz, and Yoshiaki Honda. SPIE, 2003. http://dx.doi.org/10.1117/12.465503.

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Zhu, Yu, Hao Li, Yikang Liao, Beidou Wang, Ziyu Guan, Haifeng Liu, and Deng Cai. "What to Do Next: Modeling User Behaviors by Time-LSTM." In Twenty-Sixth International Joint Conference on Artificial Intelligence. California: International Joint Conferences on Artificial Intelligence Organization, 2017. http://dx.doi.org/10.24963/ijcai.2017/504.

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Recently, Recurrent Neural Network (RNN) solutions for recommender systems (RS) are becoming increasingly popular. The insight is that, there exist some intrinsic patterns in the sequence of users' actions, and RNN has been proved to perform excellently when modeling sequential data. In traditional tasks such as language modeling, RNN solutions usually only consider the sequential order of objects without the notion of interval. However, in RS, time intervals between users' actions are of significant importance in capturing the relations of users' actions and the traditional RNN architectures are not good at modeling them. In this paper, we propose a new LSTM variant, i.e. Time-LSTM, to model users' sequential actions. Time-LSTM equips LSTM with time gates to model time intervals. These time gates are specifically designed, so that compared to the traditional RNN solutions, Time-LSTM better captures both of users' short-term and long-term interests, so as to improve the recommendation performance. Experimental results on two real-world datasets show the superiority of the recommendation method using Time-LSTM over the traditional methods.
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GAO, MINGLIANG, SHAN GAO, CHUANG YU, DEQUAN LI, SHIJI SONG, HAIMING SHI, HONGLIANG SUN, and HONGCHAO WANG. "RESEARCH AND APPLICATION OF RADIAL BASIS NETWORK BOGIE FAULT DIAGNOSIS MODEL BASED ON PARTICLE SWARM OPTIMIZATION." In 3rd International Workshop on Structural Health Monitoring for Railway System (IWSHM-RS 2021). Destech Publications, Inc., 2021. http://dx.doi.org/10.12783/iwshm-rs2021/36030.

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Bogie system is the key system that affects the safety and quality of EMU operation. The construction of fault diagnosis model for bogie system can effectively improve the safety and comfort of EMU operation. The traditional modeling method uses BP neural network to model by fitting bogie system temperature and other parameters. However, BP neural network is prone to fall into local minimum, slow convergence and poor diagnostic accuracy. In this paper, particle radial basis function neural network (PSRB) is designed by using particle swarm optimization algorithm with high convergence. Particle Swarm optimization (PSO) is used to optimize the parameters of RBF Neural Networks. According to the complexity of the input parameters of the bogie system, the input and output parameters of the model are determined. Particle swarm optimization algorithm is used to search the optimal values of the center, width and output layer weight threshold of the RBF neural network. The hybrid algorithm is applied to the fault diagnosis of bogie system, and a bogie fault diagnosis model based on particle radial basis function neural network is designed. The experimental results show that the diagnosis model can effectively improve the identification accuracy of fault diagnosis, the minimum error accuracy is 0.0055, the operation time is saved, the operation time is reduced to 1.9s, and the influence of non-target parameters on the inversion results is eliminated. The model can also be used in other EMU systems, and has practical application value.
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Ramadan, Muawia, Bashir Salah, and Bernd Noche. "Innovative Estimating Travel Time Model for Dual-Command Cycle Time of Stewart-Gough Platform in Automated Storage/Retrieval Systems." In ASME 2012 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/detc2012-70078.

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The travel time models of automated storage and retrieval systems (AS/RS’s) have been widely used in distribution and production environments. This paper extends previous work presented on impact design aspects of automated storage/retrieval systems by determining the expected cycle travel time for single command. Our new study improves the throughput performance rate of new AS/RS’s design on cycle travel time that will be specified by estimating travel time for dual command to serve as storage and retrieval (S/R) machine using a parallel wire-based Stewart-Gough platform (parallel wire robot). This improved efficiency in new design is called Stewart-Gough Platform based Automated Storage and Retrieval Systems (SGP-AS/RS’s). A numerical case study has been presented to clarify the travel time analysis based on mini unit-load storage and retrieval system. The improved throughput has been demonstrated by making a comparison between the conventional AS/RS results and the (SGP-AS/RS’s) results in the numerical case study. The effectiveness and ability of (SGP-AS/RS’s) has been proofed by determining the expected travel time for single command and dual command for random and classed-based analysis of storage assignment.
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Hajikolaei, Kambiz Haji, and G. Gary Wang. "A Global High Dimensional Metamodeling Approach With the Ability of Using Non-Uniform Sampling." In ASME 2014 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/detc2014-35316.

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In engineering design, spending excessive amount of time on physical experiments or expensive simulations makes the design costly and lengthy. This issue exacerbates when the design problem has a large number of inputs, or of high dimension. High Dimensional Model Representation (HDMR) is one powerful method in approximating high dimensional, expensive, black-box (HEB) problems. One existing HDMR implementation, Random Sampling HDMR (RS-HDMR), can build a HDMR model from random sample points with a linear combination of basis functions. The most critical issue in RS-HDMR is that calculating the coefficients for the basis functions includes integrals that are approximated by Monte Carlo summations, which are error prone with limited samples and especially with non-uniform sampling. In this paper, a new approach based on Principal Component Analysis (PCA), called PCA-HDMR, is proposed for finding the coefficients that provide the best linear combination of the bases with minimum error and without using any integral. Benchmark problems are modeled using the method and the results are compared with RS-HDMR results. With both uniform and non-uniform sampling, PCA-HDMR built more accurate models than RS-HDMR for a given set of sample points.
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Lyu, Linfeng, and Weidong Zhu. "Operational Modal Analysis of a Rotating Structure Subject to Random Excitation Using a Tracking Continuously Scanning Laser Doppler Vibrometer via an Improved Demodulation Method." In ASME 2021 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/detc2021-67674.

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Abstract A new operational modal analysis (OMA) method is developed for estimation of modal parameters (MPs) of a rotating structure (RS) subject to random excitation using a nonuniform rotating beam model, an image processing method, and an improved demodulation method. The solution to the governing equation of a nonuniform rotating beam is derived, which can be considered as the response of the beam measured by a continuously scanning laser Doppler vibrometer (CSLDV) system. A recently developed tracking CSLDV system can track and scan the RS. The image processing method determines the angular position of the RS so that the tracking CSLDV system can sweep its laser spot along a time-varying path on it. The improved demodulation method obtains undamped mode shapes (UMSs) of the RS by multiplying its measured response by sinusoids whose frequencies are its damped natural frequencies (DNFs) that are obtained from the fast Fourier transform of the measured response. Experimental investigation of the OMA method using the tracking CSLDV system is conducted, and MPs of a rotating fan blade (RFB), including DNFs and UMSs, with different constant speeds and its instantaneous MPs with a non-constant speed are estimated. Estimated first DNFs and UMSs of the stationary fan blade and RFB are compared with those from the lifting method that was previously developed by the authors.
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Ryckelynck, David. "Multidimensional Hyper-Reduction of Large Mechanical Models Involving Internal Variables." In ASME 2012 11th Biennial Conference on Engineering Systems Design and Analysis. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/esda2012-82971.

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We propose to incorporate a Response Surface (RS) approximation of variables over a parametric domain into a weak form of parametric Partial Differential Equations (PDEs). Hence a multidimensional model-reduction can be achieved. We propose a multidimensional a priori model reduction method to generate or to enrich RSs. It is coined multidimensional because the fields to forecast are defined over an augmented domain in term of dimension. They are functions of both space variables and parameters that simultaneously evolve in time. This changes the functional space related to the weak form of the PDEs and the definition of the reduced bases. It has a significant impact on the proposed model reduction method. In particular, a new point of view on interpolation of variables has to be addressed. A Multidimensional Reduced Integration Domain (MRID) is proposed to reduce the complexity of the reduced formulation. A multidimensional Hyper-Reduction method extract from the MRID truncated equilibrium equations, truncated residuals and a truncated error indicator.
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HAIJIANG, LI, LI RUBIN, AO QIUHUA, WANG WEICHENG, WANG XIUFENG, DU LEILEI, WEN JUN, and ZHU LILI. "AN INTELLIGENT METHOD FOR BEARING FAULT DIAGNOSIS BASED ON IMPROVED VMD AND GSM-SVM." In 3rd International Workshop on Structural Health Monitoring for Railway System (IWSHM-RS 2021). Destech Publications, Inc., 2021. http://dx.doi.org/10.12783/iwshm-rs2021/36024.

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In industrial sites, the running state of rolling bearings is often judged by hearing the sound with human ears. This method relies on long-term accumulation of human experience and is prone to cause occupational noise hazards. To solve this problem, this paper proposed an intelligent diagnosis method for the running state of bearings based on machine hearing. Firstly, bearing vibration signal was decomposed using an improved Variational Mode Decomposition (VMD) algorithm, by which the best mode component containing the fault characteristic was determined according to a time-frequency weighted kurtosis maximization criterion. Then, the time-domain feature indexes and psychoacoustic indexes of the best mode component were calculated to define a feature vector. Finally, the feature vectors were input into a fault classification model based on Support Vector Machine optimized by Grid Search Method (GSM-SVM) for training. The trained model was used to diagnose unknown faults of bearings. The proposed method was applied to the traction motors of EMU train for automatic bearing fault diagnose. Field test in the manufacturing factory showed that it could quickly diagnose bearing faults with a high accuracy rate.
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GUANGBING, LUO, ZENG JING, GAN FENG, and LI FANSONG. "RESEARCH ON ANALYSIS AND SOLUTION OF ABNORMAL VIBRATION FOR EMU CARBODY." In 3rd International Workshop on Structural Health Monitoring for Railway System (IWSHM-RS 2021). Destech Publications, Inc., 2021. http://dx.doi.org/10.12783/iwshm-rs2021/36036.

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Recently, the problem of abnormal vibration of the EMU carbody has occurred from time to time. When the carbody is abnormally vibrated, the Sperling index and ride comfort of the vehicle can be greatly reduced, which is unfavorable for its operation. The paper established and a vehicle-shake simulation model which was verified based on the measured wheel-rail profile and vibration data. Additionally, the causes and solutions of abnormal vehicle body vibration were studied. The research results illustrate that the EMU has a relatively high level of wheel-rail equivalent conicity in the shaking section, causing the secondary hunting instability. The main frequency of the instability is 9-10 Hz, which is close to the first-order diamond mode frequency of the carbody. Therefore, the elastic resonance of the carbody occurs, resulting in the shake phenomenon. Through simulation analysis, it is found that wheelset reprofiling and rail polishing can improve the operation stability of EMUs and effectively solve the shaking motion; Furthermore, increasing the first-order diamond mode frequency of the carbody and controlling the hunting phase of the front and rear bogies can also avoid the shaking motion. At the same time, the equivalent conicity management through the detection of the wheel profile can efficiently prevent the hunting instability and carbody shaking, providing a reference for wheel reprofiling and rail polishing.
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DENG, DESHUANG, SONG ZHANG, LEI YANG, and ZHANJUN WU. "NUMERICAL SIMULATION ON IMPACT MONITORING OF COMPOSITE STRUCTURES BASED ON PIEZOELECTRIC SENSORS." In 3rd International Workshop on Structural Health Monitoring for Railway System (IWSHM-RS 2021). Destech Publications, Inc., 2021. http://dx.doi.org/10.12783/iwshm-rs2021/36028.

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In order to verify the effectiveness of the numerical method in composite structure impact monitoring based on piezoelectric sensor, a three-dimensional finite element model of composite plate impact monitoring based on piezoelectric sensor is established, and the whole process of composite plate punch impact is simulated. Firstly, the propagation process of the stress wave is analyzed, and then the impact piezoelectric response of the sensor obtained by numerical simulation is compared with the experimental results. Both the time domain and frequency domain characteristics of the signal are consistent with experiment. The effects of different impact energy on the piezoelectric response of the sensor are also studied. In the elastic range, there is a linear relationship between the impact energy and the piezoelectric signal. Besides, the greater the energy, the earlier the arrival time of the wave, but the frequency bandwidth of the signal has not changed. In addition, it is found that the electrical signal of the piezoelectric sensor is the same as the Z-direction strain signal after normalized. Finally, the generation mechanism of the impact piezoelectric signal is revealed by using the axisymmetric finite element model of aluminum plate impact monitoring.
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Reports on the topic "Space-time in RS Model"

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De Iaco, Sandra, Sabrina Maggio, Monica Palma, and Donato Posa. On the choice of a linear coregionalization model in space-time. Cogeo@oeaw-giscience, September 2011. http://dx.doi.org/10.5242/iamg.2011.0272.

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Senin, Pavel, and Sergey Malinchik. SAX-VSM: Interpretable Time Series Classification Using SAX and Vector Space Model. Fort Belvoir, VA: Defense Technical Information Center, January 2013. http://dx.doi.org/10.21236/ada603196.

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Maydykovskiy, Igor, and Petra Užpelkis. The Concept of space-time quanta in future technologies. Intellectual Archive, December 2020. http://dx.doi.org/10.32370/iaj.2464.

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The article discusses the possibility of using the technological advantages that appear in connection with the discovery of the physical essence of Time and new interpretation of the structure of space in the form of space-time quanta. One of the problems that can be successfully solved on the basis of the new physical model is the problem of establishing the true nature of gravity. The solution to this problem is directly related to the implementation of the idea of unsupported motion based on the interaction in a certain way of the created asymmetric interference structure of longitudinal waves with the natural structure of spatial frequencies.
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Baltagi, Badi H., Georges Bresson, Anoop Chaturvedi, and Guy Lacroix. Robust dynamic space-time panel data models using ε-contamination: An application to crop yields and climate change. CIRANO, January 2023. http://dx.doi.org/10.54932/ufyn4045.

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This paper extends the Baltagi et al. (2018, 2021) static and dynamic ε-contamination papers to dynamic space-time models. We investigate the robustness of Bayesian panel data models to possible misspecification of the prior distribution. The proposed robust Bayesian approach departs from the standard Bayesian framework in two ways. First, we consider the ε-contamination class of prior distributions for the model parameters as well as for the individual effects. Second, both the base elicited priors and the ε-contamination priors use Zellner (1986)’s g-priors for the variance-covariance matrices. We propose a general “toolbox” for a wide range of specifications which includes the dynamic space-time panel model with random effects, with cross-correlated effects `a la Chamberlain, for the Hausman-Taylor world and for dynamic panel data models with homogeneous/heterogeneous slopes and cross-sectional dependence. Using an extensive Monte Carlo simulation study, we compare the finite sample properties of our proposed estimator to those of standard classical estimators. We illustrate our robust Bayesian estimator using the same data as in Keane and Neal (2020). We obtain short run as well as long run effects of climate change on corn producers in the United States.
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Maydykovskiy, Igor, and Petras Užpelkis. The Physical Essence of Time. Intellectual Archive, December 2020. http://dx.doi.org/10.32370/iaj.2450.

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The article considers the model of the space-frequency-time continuum, according to which the physical essence of Time is manifested as a fraction of electromagnetic energy spent on updating a material object in a cyclic process of copying-incarnation. For all structural levels of physical reality, the value of this fraction is a fundamental constant, which can be represented as the tangent of the loss angle, or expressed in radians, as the angle of inclination of the evolutionary spiral, which characterizes the rate of change of states or the duration of events and processes. The value of this constant can be calculated, and its value turns out to be identically equals to the square of the fine structure Constant (α2). The description of the method for identifying a new constant allows us to present the formula of Scientific Discovery as the Physical Essence of Time.
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Kularatne, Dhanushka N., Subhrajit Bhattacharya, and M. Ani Hsieh. Computing Energy Optimal Paths in Time-Varying Flows. Drexel University, 2016. http://dx.doi.org/10.17918/d8b66v.

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Autonomous marine vehicles (AMVs) are typically deployed for long periods of time in the ocean to monitor different physical, chemical, and biological processes. Given their limited energy budgets, it makes sense to consider motion plans that leverage the dynamics of the surrounding flow field so as to minimize energy usage for these vehicles. In this paper, we present two graph search based methods to compute energy optimal paths for AMVs in two-dimensional (2-D) time-varying flows. The novelty of the proposed algorithms lies in a unique discrete graph representation of the 3-D configuration space spanned by the spatio-temporal coordinates. This enables a more efficient traversal through the search space, as opposed to a full search of the spatio-temporal configuration space. Furthermore, the proposed strategy results in solutions that are closer to the global optimal when compared to greedy searches through the spatial coordinates alone. We demonstrate the proposed algorithms by computing optimal energy paths around the Channel Islands in the Santa Barbara bay using time-varying flow field forecasts generated by the Regional Ocean Model System. We verify the accuracy of the computed paths by comparing them with paths computed via an optimal control formulation.
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Sergeyev, Mykola. Ukrainian National Idea in the Modern Ukrainian Media Space. Ivan Franko National University of Lviv, February 2022. http://dx.doi.org/10.30970/vjo.2022.51.11407.

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M. Sergeyev’s article “Ukrainian National Idea in the Modern Ukrainian Media Space” states that modern Ukrainian philosophical thought tries to get rid of the flaws and stereotypes of its one-sided orientation “to the East” and tries to establish a European orientation in the minds of Ukrainian citizens. The theoretical proof of the new worldview took place throughout the formation of the Ukrainian state from Little Russia to Ukraine and presents its actual struggle for independence. It is an integral concept that reflects the process of forming theories and views of prominent Ukrainian thinkers on the place and role of Ukrainians in the becoming and development of an independent Ukrainian state. As O. Zabuzhko emphasizes, “all Ukrainian philosophical, historical, sociological thought of the past and our centuries (including the diaspora) is permeated with the sacred idea of nationalism”. The author concludes that the logic of the historical development of the Ukrainian national idea reveals only one model of its socio-political future, which implies the need for Ukraine’s integration into the European and world community. This path requires the moral and political readiness of the entire Ukrainian society for its implementation and prevents the emergence of any other - alternative ideas. Solving this problem is complicated by the need to return to Ukraine the temporarily occupied territories of Crimea, Luhansk and Donetsk regions. Of course, this model will lead to significant political and economic tensions in society (the final severance of economic relations with Russia, the closure of non-competitive industries, the outflow of labor to the west). At the same time, the orientation of the Ukrainian national idea to the west will increase competition in all branches of production and will be a condition for further self-improvement of Ukrainian society.
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Oliynyk, Kateryna, and Matteo Ciantia. Application of a finite deformation multiplicative plasticity model with non-local hardening to the simulation of CPTu tests in a structured soil. University of Dundee, December 2021. http://dx.doi.org/10.20933/100001230.

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In this paper an isotropic hardening elastoplastic constitutive model for structured soils is applied to the simulation of a standard CPTu test in a saturated soft structured clay. To allow for the extreme deformations experienced by the soil during the penetration process, the model is formulated in a fully geometric non-linear setting, based on: i) the multiplicative decomposition of the deformation gradient into an elastic and a plastic part; and, ii) on the existence of a free energy function to define the elastic behaviour of the soil. The model is equipped with two bonding-related internal variables which provide a macroscopic description of the effects of clay structure. Suitable hardening laws are employed to describe the structure degradation associated to plastic deformations. The strain-softening associated to bond degradation usually leads to strain localization and consequent formation of shear bands, whose thickness is dependent on the characteristics of the microstructure (e.g, the average grain size). Standard local constitutive models are incapable of correctly capturing this phenomenon due to the lack of an internal length scale. To overcome this limitation, the model is framed using a non-local approach by adopting volume averaged values for the internal state variables. The size of the neighbourhood over which the averaging is performed (characteristic length) is a material constant related to the microstructure which controls the shear band thickness. This extension of the model has proven effective in regularizing the pathological mesh dependence of classical finite element solutions in the post-localization regime. The results of numerical simulations, conducted for different soil permeabilities and bond strengths, show that the model captures the development of plastic deformations induced by the advancement of the cone tip; the destructuration of the clay associated with such plastic deformations; the space and time evolution of pore water pressure as the cone tip advances. The possibility of modelling the CPTu tests in a rational and computationally efficient way opens a promising new perspective for their interpretation in geotechnical site investigations.
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Collins, Clarence O., and Tyler J. Hesser. altWIZ : A System for Satellite Radar Altimeter Evaluation of Modeled Wave Heights. Engineer Research and Development Center (U.S.), February 2021. http://dx.doi.org/10.21079/11681/39699.

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This Coastal and Hydraulics Engineering Technical Note (CHETN) describes the design and implementation of a wave model evaluation system, altWIZ, which uses wave height observations from operational satellite radar altimeters. The altWIZ system utilizes two recently released altimeter databases: Ribal and Young (2019) and European Space Agency Sea State Climate Change Initiative v.1.1 level 2 (Dodet et al. 2020). The system facilitates model evaluation against 1 Hz1 altimeter data or a product created by averaging altimeter data in space and time around model grid points. The system allows, for the first time, quantitative analysis of spatial model errors within the U.S. Army Corps of Engineers (USACE) Wave Information Study (WIS) 30+ year hindcast for coastal United States. The system is demonstrated on the WIS 2017 Atlantic hindcast, using a 1/2° basin scale grid and a 1/4° regional grid of the East Coast. Consistent spatial patterns of increased bias and root-mean-square-error are exposed. Seasonal strengthening and weakening of these spatial patterns are found, related to the seasonal variation of wave energy. Some model errors correspond to areas known for high currents, and thus wave-current interaction. In conjunction with the model comparison, additional functions for pairing altimeter measurements with buoy data and storm tracks have been built. Appendices give information on the code access (Appendix I), organization and files (Appendix II), example usage (Appendix III), and demonstrating options (Appendix IV).
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Apostolatos, A., R. Rossi, and C. Soriano. D7.2 Finalization of "deterministic" verification and validation tests. Scipedia, 2021. http://dx.doi.org/10.23967/exaqute.2021.2.006.

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This deliverable focus on the verification and validation of the solvers of Kratos Multiphysics which are used within ExaQUte. These solvers comprise standard body-fitted approaches and novel embedded approaches for the Computational Fluid Dynamics (CFD) simulations carried out within ExaQUte. Firstly, the standard body-fitted CFD solver is validated on a benchmark problem of high rise building - CAARC benchmark and subsequently the novel embedded CFD solver is verified against the solution of the body-fitted solver. Especially for the novel embedded approach, a workflow is presented on which the exact parameterized Computer-Aided Design (CAD) model is used in an efficient manner for the underlying CFD simulations. It includes: A note on the space-time methods Verification results for the body-fitted solver based on the CAARC benchmark Workflow consisting of importing an exact CAD model, tessellating it and performing embedded CFD on it Verification results for the embedded solver based on a high-rise building API definition and usage
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