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A survey on rendering homogeneous participating media

Wenshi Wu, Beibei Wang, Ling-Qi Yan
2021 Computational Visual Media  
There are several categories of rendering methods which are all based on this equation, but using different solutions.  ...  In this paper, we introduce these groups, which include volume density estimation based approaches, virtual point/ray/beam lights, point based approaches, Monte Carlo based approaches, acceleration techniques  ...  Zero-variance random walk A zero-variance random walk path means creating a random walk without variance.  ... 
doi:10.1007/s41095-021-0249-1 fatcat:vuvlmd5m7bg47gcpwmxq67nnlu

A practical path guiding method for participating media

Hong Deng, Beibei Wang, Rui Wang, Nicolas Holzschuch
2020 Computational Visual Media  
In simple terms, the paths get lost in the medium. Path guiding has been proposed for surface rendering to make convergence faster by guiding the sampling process.  ...  In this paper, we introduce a path guiding solution for translucent materials.  ...  Recently, this approach has been further improved [10] , using path guiding for arbitrary homogeneous media based on zero-variance random walk theory.  ... 
doi:10.1007/s41095-020-0160-1 fatcat:25ykdkdshrglbndcklumlkbgzi

Hidden Markov Model-based Pedestrian Navigation System using MEMS Inertial Sensors

Yingjun Zhang, Wen Liu, Xuefeng Yang, Shengwei Xing
2015 Measurement Science Review  
In this paper, a foot-mounted pedestrian navigation system using MEMS inertial sensors is implemented, where the zero-velocity detection is abstracted into a hidden Markov model with 4 states and 15 observations  ...  In reference [11] , [12] , the zero velocity intervals are determined based on the variance of accelerometer values.  ...  In reference [13] , the zero velocity is determined based on norms of accelerometers and gyroscopes along with variance of accelerations.  ... 
doi:10.1515/msr-2015-0006 fatcat:i6wioemcarglbics23tl5ne5lu

Quantum limit in low-loss ring laser gyros

Zhiguo Wang Zhiguo Wang, Xingwu Long Xingwu Long, Fei Wang Fei Wang
2012 Chinese Optics Letters (COL)  
In order to solve the inconsistency above, we derive the expression for the random walk in RLGs based on laser theory.  ...  In the experiment, the random walk and laser power are tested and recorded at different discharge currents.  ...  In order to explain the inconsistency between the experimental results and theory in current literature, we analyzed the experimental phenomena based on laser theory.  ... 
doi:10.3788/col201210.061404 fatcat:ykyxkn5vovaoxfzqxyduguaaji


Ying Tan, Yuhui Shi, Xin Yao
2020 Natural Computing  
A novel quantum ant colony optimization algorithm for automated guided vehicles (AGVs) path planning based on Bloch coordinates of pheromones is proposed.  ...  The multi-stage perturbation-based mutation operation utilizes the normal random distribution with adjustable variance to perturb the chosen solutions.  ... 
doi:10.1007/s11047-020-09803-5 fatcat:you46ta7o5h3pe7t4m5kza3xwi

Study the random walking of the ISX60 market index For the Iraq Stock Exchange

Sadik Jafar Al-Attabi, Siham Jabbar Mezher, Siham Jabbar Mezher, Salim Sallal AL-Hisnawi
2019 مجلة دراسات محاسبية ومالية  
This paper aimed to test random walking through the ISX60 market index for the ability to judge market efficiency at a weak level.  ...  The study concluded accepting the hypothesis of the study that the returns of the ISX60 market index in the Iraqi market for securities does not follow the random walking in general and as a result the  ...  The independent random variable value is based on the probability function (x = xi) = ƒ (x).  ... 
doi:10.34093/jafs.v14i46.395 fatcat:4vdgxqxpbvgm7myhry4zjhuwhy

Hack distributions of rill networks and nonlinear slope length–soil loss relationships

Tyler H. Doane, Jon D. Pelletier, Mary H. Nichols
2021 Earth Surface Dynamics  
Numerical flow routing demonstrates probability functions that resemble the theoretical ones.  ...  Surface flow on rilled hillslopes tends to produce sediment yields that scale nonlinearly with total hillslope length.  ...  zero to one.  ... 
doi:10.5194/esurf-9-317-2021 fatcat:q3iqthyve5gdtggk5lh4m3w7ly

Global Navigation Using Predictable and Slow Feature Analysis in Multiroom Environments, Path Planning and Other Control Tasks [article]

Stefan Richthofer, Laurenz Wiskott
2018 arXiv   pre-print
We support this algorithm by mathematical theory and apply it to different problems.  ...  We focus on another fundamental characteristics of slow signals: They tend to yield monotonicity and one significant property of monotonicity is that local optimization is sufficient to find a global optimum  ...  SFA harmonics illustrated on a 1D random walk To illustrate the role of harmonics for one specific source, we demonstrate the theory on a simple 1D random walk on the interval [0, 100].  ... 
arXiv:1805.08565v1 fatcat:d5k47zfnsne4tl3ktn6blchn44

Efficient Coding in the Economics of Human Brain Connectomics [article]

Dale Zhou, Christopher W. Lynn, Zaixu Cui, Rastko Ciric, Graham L. Baum, Tyler M. Moore, David R. Roalf, John A. Detre, Ruben C. Gur, Raquel E. Gur, Theodore D. Satterthwaite, Danielle S. Bassett
2021 arXiv   pre-print
five predictions from the theory based on random walk communication dynamics.  ...  Our findings elucidate how macroscale connectivity supports efficient coding, and serve to foreground communication processes that utilize random walk dynamics constrained by network connectivity.  ...  to random walks propagating only based on connectome topology.  ... 
arXiv:2001.05078v2 fatcat:3f5vope56zh4va4liskj3c54em

Toward a kinetic-based probabilistic time geography

Jed A. Long, Trisalyn A. Nelson, Farouk S. Nathoo
2013 International Journal of Geographical Information Science  
Using random-walk theory, the existing 7 probabilistic time geography model characterizes movement probabilities for the space-8 time cone using a normal distribution.  ...  Following a 14 description of our model, we use a set of case-studies to demonstrate the skew-normal 15 model: a random walk, a correlated random walk, wildlife data, cyclist data, and athlete 16 movement  ...  Given that the model of Winter & 11 Yin is based on random walks, we expect the Winter & Yin model to perform better with 12 the random walk dataset.  ... 
doi:10.1080/13658816.2013.818151 fatcat:dfj6zs25u5b6dfft7njibajoru

Percolation since Saint-Flour [article]

Geoffrey R. Grimmett, Harry Kesten
2012 arXiv   pre-print
This is a short survey of work on percolation and first-passage percolation since the publication (in 1996 and 1984, respectively) of the two authors' Saint-Flour notes on these topics.  ...  Acknowledgements We thank Raphaël Cerf, Michael Damron, Christophe Garban, and Chuck Newman for their comments on a draft of this article.  ...  Percolation on non-amenable graphs. In the last 20 years, there has been a good deal of interest in random processes on graphs whose surface/volume ratio does not tend to zero.  ... 
arXiv:1207.0373v1 fatcat:qkilkcc4zre6bjrbjr67aq36au

Correlated randomness and switching phenomena

H.E. Stanley, S.V. Buldyrev, G. Franzese, S. Havlin, F. Mallamace, P. Kumar, V. Plerou, T. Preis
2010 Physica A: Statistical Mechanics and its Applications  
In the correlated random walk, the spread of a 10 4 step path is on the order of 10 3 steps, a full order of magnitude larger (Fig. 1) .  ...  In the case of the uncorrelated walk, the spread of a 10 4 step path is 10 2 .  ... 
doi:10.1016/j.physa.2010.02.023 fatcat:t2cx6nd2tfat3ffenrvwef5hne

Three-Dimensional Modeling of the Brain's ECS by Minimum Configurational Energy Packing of Fluid Vesicles

Ravi K. Nandigam, Daniel M. Kroll
2007 Biophysical Journal  
It is also shown that the specular reflection scheme is the appropriate technique for implementing zero-flux boundary conditions in random walk simulations commonly encountered in diffusion problems.  ...  For the random packings, it is found that although the absolute values for the tortuosities differ, the dependence of the tortuosity on pore volume fraction is very similar to that observed in experiment  ...  Tortuosities were computed using the approach based on homogenization theory. FIGURE 3 3 Repeat unit used in the random walk simulations of diffusion in the regular array shown inFig. 1.  ... 
doi:10.1529/biophysj.106.095547 pmid:17307830 pmcid:PMC1853163 fatcat:mdchbneaxndvtaj3xwrdkovhfe

Biased and greedy random walks on two-dimensional lattices with quenched randomness: The greedy ant within a disordered environment

T. L. Mitran, O. Melchert, A. K. Hartmann
2013 Physical Review E  
The principle characteristics of biased greedy random walks (BGRWs) on two-dimensional lattices with real-valued quenched disorder on the lattice edges are studied.  ...  Upon tuning rho, the probability to find such a feasible lattice walk increases from zero to one. This is the key feature of the percolation transition in the NWP model.  ...  The variant A is based on standard RWs, while the other three variants are based on (partially) loop erased RWs. • BGRWs of type A: this type of walk is given by a BGRW, that replaces negative edge weights  ... 
doi:10.1103/physreve.88.062101 pmid:24483380 fatcat:l7l2kqaavzd7nlbqfkyc7sxtie

On the Spatial Distribution of Cloud Particles

A. B. Kostinski, A. R. Jameson
2000 Journal of the Atmospheric Sciences  
In addition, novel counting diagrams, particularly useful for analyzing counts at low data rates, demonstrate droplet clustering and striking deviations from Poisson randomness on small (centimeter) scales  ...  The focus is on the stochastic structure in the spatial distribution of cloud particles.  ...  The Poisson simulation (b) is now performed on 272 000 bins. Here we plot the pair correlation functions based on the 1and 10-cm-interval data and for lags up to 1 m (excluding zero lag; see text).  ... 
doi:10.1175/1520-0469(2000)057<0901:otsdoc>;2 fatcat:fbqhhtl37nbcjejxm55ofnb72y
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