Geometric Scenario Research Articles

A wiggling filamentary jet at the origin of the blazar multi-wavelength behaviour

Blazars are beamed active galactic nuclei (AGNs) known for their strong multi-wavelength variability on timescales ranging from years down to minutes. Many different models have been proposed to explain this variability. We aim to investigate the suitability of the twisting jet model presented in previous works to explain the multi-wavelength behaviour of BL Lacertae, the prototype of one of the blazar classes. According to this model, the jet is inhomogeneous, curved, and twisting, and the long-term variability is due to changes in the Doppler factor due to variations in the orientation of the jet-emitting regions. We analysed optical data of the source obtained during monitoring campaigns organised by the Whole Earth Blazar Telescope (WEBT) in 2019--2022, together with radio data from the WEBT and other teams, and gamma -ray data from the Fermi satellite. In this period, BL Lacertae underwent an extraordinary activity phase, reaching its historical optical and gamma -ray brightness maxima. The application of the twisting jet model to the source light curves allows us to infer the wiggling motion of the optical, radio, and gamma -ray jet-emitting regions. The optical-radio correlation shows that the changes in the radio viewing angle follow those in the optical viewing angle by about 120 days, and it suggests that the jet is composed of plasma filaments, which is in agreement with some radio high-resolution observations of other sources. The gamma -ray emitting region is found to be co-spatial with the optical one, and the analysis of the gamma -optical correlation is consistent with both the geometric interpretation and a synchrotron self-Compton (SSC) origin of the high-energy photons. We propose a geometric scenario where the jet is made up of a pair of emitting plasma filaments in a sort of double-helix curved rotating structure, whose wiggling motion produces changes in the Doppler beaming and can thus explain the observed multi-wavelength long-term variability.

Two Repeated Transient Quasiperiodic Oscillations in the γ-Ray Emission from the Blazar 3C 279

In this work, we report for the first time two repeated transient quasiperiodic oscillations (QPOs) in the γ-ray light curve of the TeV blazar 3C 279. We search for the periodicity in the light curve and estimate its confidence level using the weighted wavelet Z-transform, the Lomb–Scargle periodogram, and the REDFIT techniques. The main results are as follows: (1) a QPO of ∼33 days (>2.5σ) is found during the flare of 117 days (MJD 55008–55125) from 2009 June to November. Interestingly, the same QPO (∼39 days) reappeared in the flaring duration from MJD 59430 to 59585, with the confidence level of >4σ. (2) Another transient QPO of ∼91 days with a significance of >3.8σ is found during a period with 455 days (MJD 58430–58985) from 2019 February to 2020 May. Under the premise of considering the QPOs reported in the literature, the QPO of ∼40 days is repeated three times and the QPO of ∼91 days is repeated twice. We discuss several physical models explaining the QPOs of this blazar. Our study may suggest that the two QPOs originate from the twin jets of the binary black holes at the center of 3C 279. The repeated occurrence of QPOs of a similar scale strongly supports the geometric scenario of a blob spiraling within the jet. Furthermore, the hypothesis of a sheath in the jet may also be a potential explanation for the repetitive γ-ray flare patterns observed in the light curve.

Performance evaluation of a parabolic cylinder collector applying the Monte Carlo ray tracing method

The purpose of this article is to evaluate the performance of a prototype parabolic trough collector for three proposed scenarios, where geometric designs with optical characteristics are tested according to the appropriate technological paradigm; low cost of maintenance and implementation, intensive local labor, materials and resources of the implementation area. The device was developed by the Energy, Automation and Control Systems Research Group GISEAC of the Unidades Tecnológicas de Santander for low-cost water heating; using materials and labor for its fabrication easily available locally. Monte Carlo ray tracing methodology was applied using the open-access software SolTrace and Tonatiuh. To select the geometric scenario to be simulated, the edge angle and the width of the primary reflection system of the device were varied. The results obtained showed that the aperture of the parabola has a direct impact on the drop in the concentration ratio (CR) percentage value and the performance of the prototype.

Role of decoupling measure on the complexity factor and isotropization of the charged anisotropic spheres

An electromagnetic field is a consequential aspect of the space carried by moving electric charges. The contemporaneous interaction of Einstein–Maxwell field could be provoked by the dispersing electro-magnetic waves owing to the warping of the spacetime. Within the complete geometric deformation scenario, current work is devoted to exploring the substantial impact of an electromagnetic field on the anisotropic spherically symmetric structures that are taken to be the seed source, and then augment to the additional source. In this case, the gravitational decoupling strategy and embedding Class-I constraint will be used as two techniques to address the issue. We compute the Einstein–Maxwell field equations for the desired configuration. The transformed metric potentials corresponding to the temporal and radial components are then applied to formulate the two distinct sets of field equations. Through the Kuchowicz-ansatz for the seed metric potential, we enforce the Karmarkar constraint to grasp the entire gravitational aspect of a static compact sphere together with the effects of charged anisotropic pressure. The uniqueness of our study is that we used isotropization and disappearing complexity requirements to derive the deformation function within the bounds of a charged scenario. Thereby, two solutions to the associated relativistic equations are then presented for physical validity. We address the fact that the existence of charged pressure anisotropy in the bounded sphere has a consequential influence on governing its stability. Furthermore, it is identified that the decoupling-constant magnitude controls the energy flow within both the generically charged fluid and the fluid matter composition.

CervicoXNet: an automated cervicogram interpretation network.

Visual inspection with acetic acid (VIA) is a pre-cancerous screening program for low-middle-income countries (LMICs). Due to the limited number of oncology-gynecologist clinicians in LMICs, VIA examinations are performed mainly by medical workers. However, the inability of the medical workers to recognize a significant pattern based on cervicograms, VIA examination produces high inter-observer variance and high false-positive rate. This study proposed an automated cervicogram interpretation using explainable convolutional neural networks named "CervicoXNet" to support medical workers decision. The total number of 779 cervicograms was used for the learning process: 487 with VIA ( +) and 292 with VIA ( -). We performed data augmentation process under a geometric transformation scenario, such process produces 7325 cervicogram with VIA ( -) and 7242 cervicogram with VIA ( +). The proposed model outperformed other deep learning models, with 99.22% accuracy, 100% sensitivity, and 98.28% specificity. Moreover, to test the robustness of the proposed model, colposcope images used to validate the model's generalization ability. The results showed that the proposed architecture still produced satisfactory performance, with 98.11% accuracy, 98.33% sensitivity, and 98% specificity. It can be proven that the proposed model has been achieved satisfactory results. To make the prediction results visually interpretable, the results are localized with a heat map in fine-grained pixels using a combination of Grad-CAM and guided backpropagation. CervicoXNet can be used an alternative early screening tool with VIA alone.

Energy- and Spectral- Efficiency Tradeoff in Nonlinear OFDM System of Visible Light Communications

light-emitting diode (LED) based visible light communication (VLC) provides a promising solution to enhance the speed and data rate for 5G and beyond, however, the nonlinear characteristic of LED that VLC greatly suffers from can lower the output power, hence causing degradation in the transmission rate. In this paper, the direct current (DC) biased optical orthogonal frequency division multiplexing (DCO-OFDM) is employed to investigate the nonlinear effect of LED on the tradeoff between energy efficiency (EE) and spectral efficiency (SE). The Rapps model is adopted to describe the nonlinear characteristic of commercial LED (OSRAM, LD-W5AM) and predistortion compensation algorithms are introduced to evaluate bit error rate (BER) affected by parameters of the LED. Based on which, the general closed-form expressions of EE-SE (ESE) tradeoff related to different system parameters under indoor VLC geometric scenario are derived. Next, effects of parameters in VLC system on the ESE tradeoff, such as the half power angle (HPA) of the LED and the effective area (EA) of the photodetector (PD), are discussed. Simulation results of the ESE tradeoff trend with different system parameters are provided, which are in well agreement with the theoretical derivation. This provides a good guideline on determining ESE-efficient parameters of the nonlinear DCO-OFDM VLC system.

Comparative study of transition FLRW and axially symmetric cosmological structures with domain walls inf(R,T) gravity

In the present article, we study the physical and geometric scenario of the inflection of the Friedmann–Lemaître–Robertson–Walker (FLRW) and an axially symmetric perfect fluid Universe with thick domain walls in f(R, T) theory of gravitation (Harko et al. Phys. Rev. D, 84, 024020 (2011)), where R and T represent Ricci scalar and trace of the stress–energy–momentum tensor, respectively, in the scenario of decelerating–accelerating transition phases. To ascertain the exact solution of the corresponding field equations, we use the concept of a time-subordinate deceleration parameter, which brings forth the scale factor [Formula: see text], where n and α are positive parameters. For n ∈ (0.27, 1], a class of accelerating phase is ensured while for n > 1, the Universe attains a phase transition from positive (decelerating) to negative (accelerating), which is uniform with recent observations. The models have been tested for physical feasibility by using stability. Physical and geometric behavior of the models are also explored.

Two hundred times enhancement of emission intensity of a heptadentate acyclic sensor coordinated with Zn2+ ion: synthesis, crystal structure and emission properties

A heptadentate N4O3 coordinated dinuclear zinc complex was synthesized. The sensor functioned as a “turn-on” fluorescence receptor only to Zn2+ ion in 3:2 v/v MeOH/water in HEPES buffer at pH 7.2 at 25 °C. A huge increase in emission intensity (approximately 200 times) of the ligand was observed in the presence of Zn2+ which was accounted for by the formation of a metal-ligand complex and thus could be used as zinc ion-selective luminescent probe, continuously emitting blue light in the presence of a UV lamp. The theoretically optimized geometry in solution state gives an idea about bond relaxation as well as change the geometric scenario of the coordinated metal ion from trigonal bipyramidal to square pyramidal.

The research of multimedia dynamic image 3d adaptive rendering method

The 3d adaptive rendering of the multimedia dynamic image is conductive to improve the quality of the image. The current method renders the multimedia dynamic image by geometric information scenario modelling which has the problem that rendering efficiency is low. To solve this problem, a 3d adaptive rendering method based on OGRE is presented in this paper. This method firstly uses compressed domain to correct segmentation of the image and then using SIFT operator and Forstner operator classifying image characteristics, finally according to the array image complete 3d adaptive image rendering. The experimental results show that this method has obvious advantages in terms of classification time, rendering energy consumption, segmentation efficiency and other aspects in comparison with other methods, which fully demonstrates that this method improves the rendering efficiency of images.

Local Near-Beltrami Structure and Depletion of the Nonlinearity in the 3D Navier–Stokes Flows

Computational simulations of turbulent flows indicate that the regions of low dissipation/enstrophy production feature high degree of local alignment between the velocity and the vorticty, i.e., the flow is locally near-Beltrami. Hence one could envision a geometric scenario in which the persistence of the local near-Beltramy property might be consistent with a (possible) finite-time singularity formation. The goal of this note is to show that this scenario is in fact prohibited if the sine of the angle between the velocity and the vorticty is small enough with respect to the local enstrophy.

On the embedding of Weyl manifolds

We discuss the possibility of extending different versions of the Campbell-Magaard theorem, which have already been established in the context of semi-Riemannian geometry, to the context of Weyl’s geometry. We show that some of the known results can be naturally extended to the new geometric scenario, although new difficulties arise. In pursuit of solving the embedding problem, we have obtained some no-go theorems. We also highlight some of the difficulties that appear in the embedding problem, which are typical of the Weylian character of the geometry. The establishing of these new results may be viewed as part of a program that highlights the possible significance of embedding theorems of increasing degrees of generality in the context of modern higher-dimensional space-time theories.

Optical and radio variability of BL Lacertae

We observed the prototype blazar, BL Lacertae, extensively in optical and radio bands during an active phase in the period 2010--2013 when the source showed several prominent outbursts. We searched for possible correlations and time lags between the optical and radio band flux variations using multifrequency data to learn about the mechanisms producing variability. During an active phase of BL Lacertae, we searched for possible correlations and time lags between multifrequency light curves of several optical and radio bands. We tried to estimate any possible variability timescales and inter-band lags in these bands. We performed optical observations in B, V, R and I bands from seven telescopes in Bulgaria, Georgia, Greece and India and obtained radio data at 36.8, 22.2, 14.5, 8 and 4.8 GHz frequencies from three telescopes in Ukraine, Finland and USA. Significant cross-correlations between optical and radio bands are found in our observations with a delay of cm-fluxes with respect to optical ones of ~250 days. The optical and radio light curves do not show any significant timescales of variability. BL Lacertae showed many optical 'mini-flares' on short time-scales. Variations on longer term timescales are mildly chromatic with superposition of many strong optical outbursts. In radio bands, the amplitude of variability is frequency dependent. Flux variations at higher radio frequencies lead the lower frequencies by days or weeks. The optical variations are consistent with being dominated by a geometric scenario where a region of emitting plasma moves along a helical path in a relativistic jet. The frequency dependence of the variability amplitude supports an origin of the observed variations intrinsic to the source.

Classical resolution of black hole singularities in arbitrary dimension

A metric-affine approach is employed to study higher-dimensional modified gravity theories involving different powers and contractions of the Ricci tensor. It is shown that the field equations are always second-order, as opposed to the standard metric approach, where this is only achieved for Lagrangians of the Lovelock type. We point out that this property might have relevant implications for the AdS/CFT correspondence in black hole scenarios. We illustrate these aspects by considering the case of Born-Infeld gravity in $d$ dimensions, where we work out exact solutions for electrovacuum configurations. Our results put forward that black hole singularities in arbitrary dimensions can be cured in a purely classical geometric scenario governed by second-order field equations.

Vortex stretching and criticality for the three-dimensional Navier-Stokes equations

A mathematical evidence—in a statistically significant sense—of a geometric scenario leading to criticality of the Navier-Stokes problem is presented.

How to meet asynchronously (almost) everywhere

Two mobile agents (robots) with distinct labels have to meet in an arbitrary, possibly infinite, unknown connected graph or in an unknown connected terrain in the plane. Agents are modeled as points, and the route of each of them only depends on its label and on the unknown environment. The actual walk of each agent also depends on an asynchronous adversary that may arbitrarily vary the speed of the agent, stop it, or even move it back and forth, as long as the walk of the agent is continuous, does not leave its route and covers all of it. Meeting in a graph means that both agents must be at the same time in some node or in some point inside an edge of the graph, while meeting in a terrain means that both agents must be at the same time in some point of the terrain. Does there exist a deterministic algorithm that allows any two agents to meet in any unknown environment in spite of this very powerful adversary? We give deterministic rendezvous algorithms for agents starting at arbitrary nodes of any anonymous connected graph (finite or infinite) and for agents starting at any interior points with rational coordinates in any closed region of the plane with path-connected interior. In the geometric scenario agents may have different compasses and different units of length. While our algorithms work in a very general setting -- agents can, indeed, meet almost everywhere -- we show that none of these few limitations imposed on the environment can be removed. On the other hand, our algorithm also guarantees the following approximate rendezvous for agents starting at arbitrary interior points of a terrain as previously stated agents will eventually get to within an arbitrarily small positive distance from each other.

VASE: Volume‐Aware Surface Evolution for Surface Reconstruction from Incomplete Point Clouds

AbstractObjects with many concavities are difficult to acquire using laser scanners. The highly concave areas are hard to access by a scanner due to occlusions by other components of the object. The resulting point scan typically suffers from large amounts of missing data. Methods that use surface‐based priors rely on local surface estimates and perform well only when filling small holes. When the holes become large, the reconstruction problem becomes severely under‐constrained, which necessitates the use of additional reconstruction priors. In this paper, we introduce weak volumetric priors which assume that the volume of a shape varies smoothly and that each point cloud sample is visible from outside the shape. Specifically, the union of view‐rays given by the scanner implicitly carves the exterior volume, while volumetric smoothness regularizes the internal volume. We incorporate these priors into a surface evolution framework where a new energy term defined by volumetric smoothness is introduced to handle large amount of missing data. We demonstrate the effectiveness of our method on objects exhibiting deep concavities, and show its general applicability over a broader spectrum of geometric scenario.

Assetto strutturale della catena a pieghe e sovrascorrimenti Umbro-Sabina (Italia Centrale) derivato dal rilevamento dei fogli 366 “Palombara Sabina” e 375 “Tivoli” (Progetto CARG).

Structural Scheme of the Umbria-Sabina fold-and-thrust belt (Central Italy) derived from the geological mapping of 366 Palombara Sabina and 375 Tivoli sheets (CARG Project).The geological mapping of the sheets 366 Palombara Sabina and 375 Tivoli (1: 50.000 scale; CARG Project; in preparation) allowed the revision of the structural setting of the westernmost portion of this part of the Neogene fold-and-thrust belt of the Central Apennines.The area comprises the Cornicolani, Lucretili, eastern Sabini, Tiburtini, Ruffi and Prenestini Mts (Latium region). Most of the area (Cornicolani, Lucretili and Tiburtini Mts) is made of the pre-orogenic deposits (Upper Triassic-Serravallian) referred to the calcareous-marly-siliceous Sabina Succession, that were accumulated in the southern part of the Umbria-Marche-Sabina Pelagic Basin (Sabina Domain), proximal to the Latium-Abruzzi Carbonate Platform. In general, in the eastern areas, more proximal to the platform, coarser lithofacies crop out. Moreover, in the Cornicolani and western Lucretili Mts (Castelvecchio Mt) areally restricted outcrops of condensed pelagic carbonates (Bugarone Group and calcari dolomitici di S. Angelo Romano) document the occurrence of Jurassic intrabasinal structural highs evolved into Pelagic Carbonate Platforms. These structural highs were generated after the Early Jurassic rifting, that broke-up the pre-existing carbonate platform (Calcare Massiccio).In the mapped area, the Latium - Abruzzi Platform is represented in the hangingwall of the Olevano-Antrodoco line only in the southern Prenestini Mts (Rocca di Cave), by upper Cretaceous shelf carbonates. Whereas in the footwall of the Olevano-Antrodoco line it crops out along the Aniene River valley. Both Sabina and Latium - Abruzzi successions are overlain by upper Tortonian - lower Messinian marls and siliciclastic syn-orogenic deposits, best observed in the easternmost areas and inbetween the Ruffi and Prenestini Mts.In their turn, the syn-orogenic deposits are unconformably overlain by post-orogenic Plio-Pleistocene marine clastic deposits and Quaternary volcanic and alluvial sediments. From a structural point of view, the Sabina Domain is arranged into several thrust sheets verging toward the east, developed in middle-late Miocene-early Pliocene times. The early Pliocene Olevano-Antrodoco out-of-sequence thrust marks the eastern tectonic boundary of this structural domain where the pelagic and slope sediments overthrust the Latium - Abruzzi Carbonate Platform and its associated syn-orogenic deposits. In late Miocene-early Pliocene extensional tectonics down-threw the western border of this imbricated structure enhancing the marine ingression along the peri-Tyrrhenian margin. The western border of the region was also reactivated by N-S right-lateral strike-slip fault dissecting the earlier structures in Pleistocene times.From top of the orogenic edifice three main tectonic units have been identified:- Unit 1 (Morra Mt) made up of Upper Triassic to Lower Jurassic dolomite limestones (Dolomia Principale) and Calcare Massiccio, overthrust onto unit 2.- Unit 2 (comprising Cornicolani Mts, western Lucretili Mts) made up of Dolomia Principale, Calcare Massiccio, Corniola detritica and, in the Cornicolani and western Lucretili Mts, Bugarone Group. Long wavelength upright folds mainly characterize this unit and faults with high angle cuts-offs prevail, and Jurassic structural highs occur (Cornicolani Mts, Castelvecchio Mt).- Unit 3 (comprising Elci Mt, eastern Lucretili Mts and Tiburtini Mts) made up of most of the Sabina basin stratigraphic succession - from Corniola detritica Fm. to the Guadagnolo Member (marly lithofacies); the unit is characterized by NW to NE verging overturned to recumbent folds.- Unit 4 (comprising Prenestini Mts, Ruffi Mts and eastern Sabini Mts) made up of the upper portion of the basin succession between the Marne a Fucoidi and Upper Miocene siliciclastics and the Rocca di Cave carbonate platform succession.This unit is made up by two sub-units, based on the deformation-style and stratigraphy: the sub-unit 4A (Granaro Mt, Colle Serviano and Arzillo Mt in the western Prenestini Mts), is mainly characterized by east-verging packed asymmetrical folds with sub-vertical axial-planes, and N-S striking dextral-transpressive faults. The sub-unit 4B (Castel Madama area, eastern and central Prenestini Mts, Ruffi Mts and eastern Sabini Mts) is characterized by a wide symmetrical anticline in the western portion, and by folds with very steep axial planes, and N-S to NNW-striking dextral transpressional faults.The units are separated by low-angle thrusts or by high-angle transpressive faults: the stratigraphic successions characterizing each unit rejuvenate eastward. The innermost unit 1 and unit 2, where massive or poorly stratified deposits are exposed, are mainly deformed by high angle faults. Whereas the more external unit 3 and unit 4 are composed by alternating carbonate, marls and siliciclastics, and are mostly characterized by east-verging slightly to strongly asymmetrical and overturned folds.A new geometric and kinematic scenario for the Neogene evolution of the units preserved in the hangingwall of the Olevano-Antrodoco thrust is here outlined.The revision of the stratigraphy and structural data put in evidence the presence of paleo-structures of the Tethyan passive margin not evidenced in the past cartography, their influence on Neogene compressive structures and the coexistence of non-coaxial structural trends in areas of limited extension.

High velocity outflows in narrow absorption line quasars

The current paradigm for the AGN phenomenon is a central engine that consists of an inflow of material accreting in the form of a disk onto a supermassive black hole. Observations in the UV and optical find high velocity ionized material outflowing from the black hole. We present results from Suzaku and XMM-Newton observations of a sample of intrinsic NAL quasars with high velocity outflows. Our derived values of the intrinsic column densities of the X-ray absorbers are consistent with an outflow scenario in which NAL quasars are viewed at smaller inclination angles than BAL quasars. We find that the distributions of α OX and Δ α OX of the NAL quasars of our sample differ significantly from those of BAL quasars and SDSS radio-quiet quasars. The NAL quasars are not significantly absorbed in the X-ray band and the positive values of Δ α OX suggest absorption in the UV band. The positive values of Δ α OX of the intrinsic NAL quasars can be explained in a geometric scenario where our lines of sight towards the compact X-ray hot coronae of NAL quasars do not traverse the absorbing wind whereas lines of sight towards their UV emitting accretion disks do intercept the outflowing absorbers.

Heat Transfer and Thermodynamic Analyses of Some Typical Encapsulated Ice Geometries During Discharging Process

This study deals with the process of melting in some typical encapsulated ice thermal energy storage (TES) geometries. Cylindrical and slab capsules are compared with spherical capsules when subjected to a flowing heat transfer fluid (HTF). The effect of inlet HTF temperature and flow rate as well as the reference temperatures are investigated, and the resulting solidification and melting times, energy efficiencies, and exergy efficiencies are documented. Using ANSYS GAMBIT and FLUENT 6.0 softwares, all geometries are created, and the appropriate boundary and initial conditions are selected for the finite volume solver to proceed. Sufficient flow parameters are monitored during transient solutions to enable the calculation of all energy and exergy efficiencies. The energetically most efficient geometric scenario is obtained for the slab geometry, while the spherical geometry exergetically achieves the highest efficiencies. The difference between the two results is mainly through the accounting of entropy generation and exergy destroyed, and the largest mode of thermal exergy loss is found to be through entropy generation resulting from heat transfer accompanying phase change, although viscous dissipation is included in the analysis. All efficiency values tend to increase with decreasing HTF flow rate, but exergetically the best scenario appears to be for the spherical capsules with low inlet HTF temperature. Energy efficiency values are all well over 99%, while the exergy efficiency values range from around 72% to 84%, respectively. The results indicate that energy analyses, while able to predict viscous dissipation losses effectively, cannot correctly quantify losses inherent in cold TES systems, and in some instances predict higher than normal efficiencies and inaccurate optimal parameters when compared with exergy analyses.

SU-GG-T-125: Incorporating Uncertainty in Radiation Therapy Optimization with Scenario and Voxel Sampling

Purpose: The inclusion of motion and uncertainty in treatment plan optimization requires the use of a potentially large number of geometric instances (scenarios), which may be computationally intractable. We seek to provide a fast, flexible approach that is practical to implement. Method and Materials: When using a gradient‐based optimization method, we have found that not every voxel and scenario needs to be computed at every step to converge to a near‐optimal solution. We first create a model of the dose actually delivered to the patient for a given set of beamlet intensities and geometric scenario. Based on this dose, we calculate the value of an objective function, a measure of how far a dose is from satisfying our clinical goals. We typically minimize the expected value of this objective function. On each step of the optimization, we use several scenario samples to estimate the expected objective. To further speed up the estimate, we only calculate the dose to a fraction of the voxels within the patient per scenario. We use this sampling to estimate the gradient, which we use in a gradient‐based optimization algorithm. At each step of the algorithm we use sample new scenarios and voxels. We automatically tune the sampling rate for various structures by choosing the number of scenarios and voxels samples per step that minimizes the variance in the estimated objective. Results: So far we have tested the algorithm on 5 cases with a variety of treatment sites and several different motion models for IMRT and IMPT. Based on these cases, we find that voxel sampling combined with scenario sampling is over an order of magnitude faster than scenario sampling alone. This acceleration is achieved without sacrificing plan quality. Conclusion: The new approach is a fast, flexible way of incorporating uncertainty into the optimization.