WorldWideScience

Sample records for global mars multiscale

  1. Mars Pathfinder and Mars Global Surveyor Outreach Compilation

    1999-09-01

    This videotape is a compilation of the best NASA JPL (Jet Propulsion Laboratory) videos of the Mars Pathfinder and Mars Global Surveyor missions. The mission is described using animation and narration as well as some actual footage of the entire sequence of mission events. Included within these animations are the spacecraft orbit insertion; descent to the Mars surface; deployment of the airbags and instruments; and exploration by Sojourner, the Mars rover. JPL activities at spacecraft control during significant mission events are also included at the end. The spacecraft cameras pan the surrounding Mars terrain and film Sojourner traversing the surface and inspecting rocks. A single, brief, processed image of the Cydonia region (Mars face) at an oblique angle from the Mars Global Surveyor is presented. A description of the Mars Pathfinder mission, instruments, landing and deployment process, Mars approach, spacecraft orbit insertion, rover operation are all described using computer animation. Actual color footage of Sojourner as well as a 360 deg pan of the Mars terrain surrounding the spacecraft is provided. Lower quality black and white photography depicting Sojourner traversing the Mars surface and inspecting Martian rocks also is included.

  2. Multiscale Drivers of Global Environmental Health

    Desai, Manish Anil

    In this dissertation, I motivate, develop, and demonstrate three such approaches for investigating multiscale drivers of global environmental health: (1) a metric for analyzing contributions and responses to climate change from global to sectoral scales, (2) a framework for unraveling the influence of environmental change on infectious diseases at regional to local scales, and (3) a model for informing the design and evaluation of clean cooking interventions at community to household scales. The full utility of climate debt as an analytical perspective will remain untapped without tools that can be manipulated by a wide range of analysts, including global environmental health researchers. Chapter 2 explains how international natural debt (IND) apportions global radiative forcing from fossil fuel carbon dioxide and methane, the two most significant climate altering pollutants, to individual entities -- primarily countries but also subnational states and economic sectors, with even finer scales possible -- as a function of unique trajectories of historical emissions, taking into account the quite different radiative efficiencies and atmospheric lifetimes of each pollutant. Owing to its straightforward and transparent derivation, IND can readily operationalize climate debt to consider issues of equity and efficiency and drive scenario exercises that explore the response to climate change at multiple scales. Collectively, the analyses presented in this chapter demonstrate how IND can inform a range of key question on climate change mitigation at multiple scales, compelling environmental health towards an appraisal of the causes and not just the consequences of climate change. The environmental change and infectious disease (EnvID) conceptual framework of Chapter 3 builds on a rich history of prior efforts in epidemiologic theory, environmental science, and mathematical modeling by: (1) articulating a flexible and logical system specification; (2) incorporating

  3. A Global Electric Circuit on Mars

    Delory, G. T.; Farrell, W. M.; Desch, M. D.

    2001-01-01

    We describe conditions on the surface of Mars conducive to the formation of a martian global electric circuit, in a direct analogy to the terrestrial case where atmospheric currents and electric fields are generated worldwide through the charging in thunderstorms. Additional information is contained in the original extended abstract.

  4. Global stratigraphy. [of planet Mars

    Tanaka, Kenneth L.; Scott, David H.; Greeley, Ronald

    1992-01-01

    Attention is given to recent major advances in the definition and documentation of Martian stratigraphy and geology. Mariner 9 provided the images for the first global geologic mapping program, resulting in the recognition of the major geologic processes that have operated on the planet, and in the definition of the three major chronostratigraphic divisions: the Noachian, Hesperian, and Amazonian Systems. Viking Orbiter images permitted the recognition of additional geologic units and the formal naming of many formations. Epochs are assigned absolute ages based on the densities of superposed craters and crater-flux models. Recommendations are made with regard to future areas of study, namely, crustal stratigraphy and structure, the highland-lowland boundary, the Tharsis Rise, Valles Marineris, channels and valley networks, and possible Martian oceans, lakes, and ponds.

  5. Global sensitivity analysis of multiscale properties of porous materials

    Um, Kimoon; Zhang, Xuan; Katsoulakis, Markos; Plechac, Petr; Tartakovsky, Daniel M.

    2018-02-01

    Ubiquitous uncertainty about pore geometry inevitably undermines the veracity of pore- and multi-scale simulations of transport phenomena in porous media. It raises two fundamental issues: sensitivity of effective material properties to pore-scale parameters and statistical parameterization of Darcy-scale models that accounts for pore-scale uncertainty. Homogenization-based maps of pore-scale parameters onto their Darcy-scale counterparts facilitate both sensitivity analysis (SA) and uncertainty quantification. We treat uncertain geometric characteristics of a hierarchical porous medium as random variables to conduct global SA and to derive probabilistic descriptors of effective diffusion coefficients and effective sorption rate. Our analysis is formulated in terms of solute transport diffusing through a fluid-filled pore space, while sorbing to the solid matrix. Yet it is sufficiently general to be applied to other multiscale porous media phenomena that are amenable to homogenization.

  6. Multiscale global identification of porous structures

    Hatłas, Marcin; Beluch, Witold

    2018-01-01

    The paper is devoted to the evolutionary identification of the material constants of porous structures based on measurements conducted on a macro scale. Numerical homogenization with the RVE concept is used to determine the equivalent properties of a macroscopically homogeneous material. Finite element method software is applied to solve the boundary-value problem in both scales. Global optimization methods in form of evolutionary algorithm are employed to solve the identification task. Modal analysis is performed to collect the data necessary for the identification. A numerical example presenting the effectiveness of proposed attitude is attached.

  7. Mars Global Reference Atmospheric Model 2010 Version: Users Guide

    Justh, H. L.

    2014-01-01

    This Technical Memorandum (TM) presents the Mars Global Reference Atmospheric Model 2010 (Mars-GRAM 2010) and its new features. Mars-GRAM is an engineering-level atmospheric model widely used for diverse mission applications. Applications include systems design, performance analysis, and operations planning for aerobraking, entry, descent and landing, and aerocapture. Additionally, this TM includes instructions on obtaining the Mars-GRAM source code and data files as well as running Mars-GRAM. It also contains sample Mars-GRAM input and output files and an example of how to incorporate Mars-GRAM as an atmospheric subroutine in a trajectory code.

  8. Mixed multiscale finite element methods using approximate global information based on partial upscaling

    Jiang, Lijian; Efendiev, Yalchin; Mishev, IIya

    2009-01-01

    The use of limited global information in multiscale simulations is needed when there is no scale separation. Previous approaches entail fine-scale simulations in the computation of the global information. The computation of the global information

  9. Analysis of global multiscale finite element methods for wave equations with continuum spatial scales

    Jiang, Lijian; Efendiev, Yalchin; Ginting, Victor

    2010-01-01

    In this paper, we discuss a numerical multiscale approach for solving wave equations with heterogeneous coefficients. Our interest comes from geophysics applications and we assume that there is no scale separation with respect to spatial variables. To obtain the solution of these multiscale problems on a coarse grid, we compute global fields such that the solution smoothly depends on these fields. We present a Galerkin multiscale finite element method using the global information and provide a convergence analysis when applied to solve the wave equations. We investigate the relation between the smoothness of the global fields and convergence rates of the global Galerkin multiscale finite element method for the wave equations. Numerical examples demonstrate that the use of global information renders better accuracy for wave equations with heterogeneous coefficients than the local multiscale finite element method. © 2010 IMACS.

  10. Analysis of global multiscale finite element methods for wave equations with continuum spatial scales

    Jiang, Lijian

    2010-08-01

    In this paper, we discuss a numerical multiscale approach for solving wave equations with heterogeneous coefficients. Our interest comes from geophysics applications and we assume that there is no scale separation with respect to spatial variables. To obtain the solution of these multiscale problems on a coarse grid, we compute global fields such that the solution smoothly depends on these fields. We present a Galerkin multiscale finite element method using the global information and provide a convergence analysis when applied to solve the wave equations. We investigate the relation between the smoothness of the global fields and convergence rates of the global Galerkin multiscale finite element method for the wave equations. Numerical examples demonstrate that the use of global information renders better accuracy for wave equations with heterogeneous coefficients than the local multiscale finite element method. © 2010 IMACS.

  11. Toward a global multi-scale heliophysics observatory

    Semeter, J. L.

    2017-12-01

    We live within the only known stellar-planetary system that supports life. What we learn about this system is not only relevant to human society and its expanding reach beyond Earth's surface, but also to our understanding of the origins and evolution of life in the universe. Heliophysics is focused on solar-terrestrial interactions mediated by the magnetic and plasma environment surrounding the planet. A defining feature of energy flow through this environment is interaction across physical scales. A solar disturbance aimed at Earth can excite geospace variability on scales ranging from thousands of kilometers (e.g., global convection, region 1 and 2 currents, electrojet intensifications) to 10's of meters (e.g., equatorial spread-F, dispersive Alfven waves, plasma instabilities). Most "geospace observatory" concepts are focused on a single modality (e.g., HF/UHF radar, magnetometer, optical) providing a limited parameter set over a particular spatiotemporal resolution. Data assimilation methods have been developed to couple heterogeneous and distributed observations, but resolution has typically been prescribed a-priori and according to physical assumptions. This paper develops a conceptual framework for the next generation multi-scale heliophysics observatory, capable of revealing and quantifying the complete spectrum of cross-scale interactions occurring globally within the geospace system. The envisioned concept leverages existing assets, enlists citizen scientists, and exploits low-cost access to the geospace environment. Examples are presented where distributed multi-scale observations have resulted in substantial new insight into the inner workings of our stellar-planetary system.

  12. Mars Global Digital Dune Database; MC-1

    Hayward, R.K.; Fenton, L.K.; Tanaka, K.L.; Titus, T.N.; Colaprete, A.; Christensen, P.R.

    2010-01-01

    The Mars Global Digital Dune Database presents data and describes the methodology used in creating the global database of moderate- to large-size dune fields on Mars. The database is being released in a series of U.S. Geological Survey (USGS) Open-File Reports. The first release (Hayward and others, 2007) included dune fields from 65 degrees N to 65 degrees S (http://pubs.usgs.gov/of/2007/1158/). The current release encompasses ~ 845,000 km2 of mapped dune fields from 65 degrees N to 90 degrees N latitude. Dune fields between 65 degrees S and 90 degrees S will be released in a future USGS Open-File Report. Although we have attempted to include all dune fields, some have likely been excluded for two reasons: (1) incomplete THEMIS IR (daytime) coverage may have caused us to exclude some moderate- to large-size dune fields or (2) resolution of THEMIS IR coverage (100m/pixel) certainly caused us to exclude smaller dune fields. The smallest dune fields in the database are ~ 1 km2 in area. While the moderate to large dune fields are likely to constitute the largest compilation of sediment on the planet, smaller stores of sediment of dunes are likely to be found elsewhere via higher resolution data. Thus, it should be noted that our database excludes all small dune fields and some moderate to large dune fields as well. Therefore, the absence of mapped dune fields does not mean that such dune fields do not exist and is not intended to imply a lack of saltating sand in other areas. Where availability and quality of THEMIS visible (VIS), Mars Orbiter Camera narrow angle (MOC NA), or Mars Reconnaissance Orbiter (MRO) Context Camera (CTX) images allowed, we classified dunes and included some dune slipface measurements, which were derived from gross dune morphology and represent the prevailing wind direction at the last time of significant dune modification. It was beyond the scope of this report to look at the detail needed to discern subtle dune modification. It was also

  13. Multi-scale climate modelling over Southern Africa using a variable-resolution global model

    Engelbrecht, FA

    2011-12-01

    Full Text Available -mail: fengelbrecht@csir.co.za Multi-scale climate modelling over Southern Africa using a variable-resolution global model FA Engelbrecht1, 2*, WA Landman1, 3, CJ Engelbrecht4, S Landman5, MM Bopape1, B Roux6, JL McGregor7 and M Thatcher7 1 CSIR Natural... improvement. Keywords: multi-scale climate modelling, variable-resolution atmospheric model Introduction Dynamic climate models have become the primary tools for the projection of future climate change, at both the global and regional scales. Dynamic...

  14. The Global and Local Characters of Mars Perihelion Cloud Trails

    Clancy, R. T.; Wolff, M. J.; Smith, M. D.; Cantor, B. A.; Spiga, A.

    2014-12-01

    We present the seasonal and spatial distribution of Mars perihelion cloud trails as mapped from Mars Reconnaissance Orbiter (MRO) MARCI (Mars Color Imager) imaging observations in 2 ultraviolet and 3 visible filters. The extended 2007-2013 period of MARCI daily global image maps reveals the widespread distribution of these high altitude clouds, which are somewhat paradoxically associated with specific surface regions. They appear as longitudinally extended (300-700 km) cloud trails with distinct leading plumes of substantial ice cloud optical depths (0.02-0.2) for such high altitudes of occurrence (40-50 km, from cloud surface shadow measurements). These plumes generate small ice particles (Reff~1 to reflect locally elevated mesospheric water ice formation that may impact the global expression of mesospheric water ice aerosols.

  15. Heat structure coupling of CUPID and MARS for the multi-scale simulation of the passive auxiliary feedwater system

    Kyu Cho, Hyoung; Cho, Yun Je; Yoon, Han Young

    2014-01-01

    Graphical abstract: - Highlights: • PAFS is designed to replace a conventional active auxiliary feedwater system. • Multi-D T/H analysis code, CUPID was coupled with the 1-D system analysis code MARS. • The coupled CUPID and MARS was applied for the multi-scale analysis of the PAFS test facility. • The simulation result showed that the coupled code can reproduce important phenomena in PAFS. - Abstract: For the analysis of transient two-phase flows in nuclear reactor components, a three-dimensional thermal hydraulics code, named CUPID, has been developed. In the present study, the CUPID code was coupled with a system analysis code MARS in order to apply it for the multi-scale thermal-hydraulic analysis of the passive auxiliary feedwater system (PAFS). The PAFS is one of the advanced safety features adopted in the Advanced Power Reactor Plus (APR+), which is intended to completely replace the conventional active auxiliary feedwater system. For verification of the coupling and validation of the coupled code, the PASCAL test facility was simulated, which was constructed with an aim of validating the cooling and operational performance of the PAFS. The two-phase flow phenomena of the steam supply system including the condensation inside the heat exchanger tube were calculated by MARS while the natural circulation and the boil-off in the large water pool that contains the heat exchanger tube were simulated by CUPID. This paper presents the description of the PASCAL facility, the coupling method and the simulation results using the coupled code

  16. Global Distribution of Dissected Duricrust on Mars

    Mustard, J. F.; Cooper, C. D.

    2000-01-01

    Evidence for dissected duricrust was identified in high resolution MOC images. Analysis of all available images was used to map the global distribution of this terrain. It is apparently restricted to two latitude bands: 30-60 deg. N and 30-60 deg. S.

  17. Mixed multiscale finite element methods using approximate global information based on partial upscaling

    Jiang, Lijian

    2009-10-02

    The use of limited global information in multiscale simulations is needed when there is no scale separation. Previous approaches entail fine-scale simulations in the computation of the global information. The computation of the global information is expensive. In this paper, we propose the use of approximate global information based on partial upscaling. A requirement for partial homogenization is to capture long-range (non-local) effects present in the fine-scale solution, while homogenizing some of the smallest scales. The local information at these smallest scales is captured in the computation of basis functions. Thus, the proposed approach allows us to avoid the computations at the scales that can be homogenized. This results in coarser problems for the computation of global fields. We analyze the convergence of the proposed method. Mathematical formalism is introduced, which allows estimating the errors due to small scales that are homogenized. The proposed method is applied to simulate two-phase flows in heterogeneous porous media. Numerical results are presented for various permeability fields, including those generated using two-point correlation functions and channelized permeability fields from the SPE Comparative Project (Christie and Blunt, SPE Reserv Evalu Eng 4:308-317, 2001). We consider simple cases where one can identify the scales that can be homogenized. For more general cases, we suggest the use of upscaling on the coarse grid with the size smaller than the target coarse grid where multiscale basis functions are constructed. This intermediate coarse grid renders a partially upscaled solution that contains essential non-local information. Numerical examples demonstrate that the use of approximate global information provides better accuracy than purely local multiscale methods. © 2009 Springer Science+Business Media B.V.

  18. Multi-Scale Particle Size Distributions of Mars, Moon and Itokawa based on a time-maturation dependent fragmentation model

    Charalambous, C. A.; Pike, W. T.

    2013-12-01

    We present the development of a soil evolution framework and multiscale modelling of the surface of Mars, Moon and Itokawa thus providing an atlas of extra-terrestrial Particle Size Distributions (PSD). These PSDs are profoundly based on a tailoring method which interconnects several datasets from different sites captured by the various missions. The final integrated product is then fully justified through a soil evolution analysis model mathematically constructed via fundamental physical principles (Charalambous, 2013). The construction of the PSD takes into account the macroscale fresh primary impacts and their products, the mesoscale distributions obtained by the in-situ data of surface missions (Golombek et al., 1997, 2012) and finally the microscopic scale distributions provided by Curiosity and Phoenix Lander (Pike, 2011). The distribution naturally extends at the magnitudinal scales at which current data does not exist due to the lack of scientific instruments capturing the populations at these data absent scales. The extension is based on the model distribution (Charalambous, 2013) which takes as parameters known values of material specific probabilities of fragmentation and grinding limits. Additionally, the establishment of a closed-form statistical distribution provides a quantitative description of the soil's structure. Consequently, reverse engineering of the model distribution allows the synthesis of soil that faithfully represents the particle population at the studied sites (Charalambous, 2011). Such representation essentially delivers a virtual soil environment to work with for numerous applications. A specific application demonstrated here will be the information that can directly be extracted for the successful drilling probability as a function of distance in an effort to aid the HP3 instrument of the 2016 Insight Mission to Mars. Pike, W. T., et al. "Quantification of the dry history of the Martian soil inferred from in situ microscopy

  19. Development of a Sampling-Based Global Sensitivity Analysis Workflow for Multiscale Computational Cancer Models

    Wang, Zhihui; Deisboeck, Thomas S.; Cristini, Vittorio

    2014-01-01

    There are two challenges that researchers face when performing global sensitivity analysis (GSA) on multiscale in silico cancer models. The first is increased computational intensity, since a multiscale cancer model generally takes longer to run than does a scale-specific model. The second problem is the lack of a best GSA method that fits all types of models, which implies that multiple methods and their sequence need to be taken into account. In this article, we therefore propose a sampling-based GSA workflow consisting of three phases – pre-analysis, analysis, and post-analysis – by integrating Monte Carlo and resampling methods with the repeated use of analysis of variance (ANOVA); we then exemplify this workflow using a two-dimensional multiscale lung cancer model. By accounting for all parameter rankings produced by multiple GSA methods, a summarized ranking is created at the end of the workflow based on the weighted mean of the rankings for each input parameter. For the cancer model investigated here, this analysis reveals that ERK, a downstream molecule of the EGFR signaling pathway, has the most important impact on regulating both the tumor volume and expansion rate in the algorithm used. PMID:25257020

  20. Mars Relays Satellite Orbit Design Considerations for Global Support of Robotic Surface Missions

    Hastrup, Rolf; Cesarone, Robert; Cook, Richard; Knocke, Phillip; McOmber, Robert

    1993-01-01

    This paper discusses orbit design considerations for Mars relay satellite (MRS)support of globally distributed robotic surface missions. The orbit results reported in this paper are derived from studies of MRS support for two types of Mars robotic surface missions: 1) the mars Environmental Survey (MESUR) mission, which in its current definition would deploy a global network of up to 16 small landers, and 2)a Small Mars Sample Return (SMSR) mission, which included four globally distributed landers, each with a return stage and one or two rovers, and up to four additional sets of lander/rover elements in an extended mission phase.

  1. Global duricrust on Mars - Analysis of remote-sensing data

    Jakosky, B. M.; Christensen, P. R.

    1986-01-01

    A study is conducted of the infrared thermal emission, radio thermal emission, and radar reflection data sets with the objective to obtain a simple and self-consistent model for the Mars surface. The results are compared with in situ observations at the Viking Lander sites. Attention is given to thermal inertia values, the abundance of surface rocks, radar/thermal correlations, diurnal temperature deviations, and radio emission data. It is suggested that all of the global remote-sensing data sets considered can be reconciled on the basis of variations in the degree of formation of a case-hardened crust or duricrust. On the other hand, no other model which has been proposed in conjunction with any individual data set can satisfy all of the constraints discussed.

  2. Multi-scale spatial modeling of human exposure from local sources to global intake

    Wannaz, Cedric; Fantke, Peter; Jolliet, Olivier

    2018-01-01

    Exposure studies, used in human health risk and impact assessments of chemicals are largely performed locally or regionally. It is usually not known how global impacts resulting from exposure to point source emissions compare to local impacts. To address this problem, we introduce Pangea......, an innovative multi-scale, spatial multimedia fate and exposure assessment model. We study local to global population exposure associated with emissions from 126 point sources matching locations of waste-to-energy plants across France. Results for three chemicals with distinct physicochemical properties...... occur within a 100 km radius from the source. This suggests that, by neglecting distant low-level exposure, local assessments might only account for fractions of global cumulative intakes. We also study ~10,000 emission locations covering France more densely to determine per chemical and exposure route...

  3. Global Appearance Applied to Visual Map Building and Path Estimation Using Multiscale Analysis

    Francisco Amorós

    2014-01-01

    Full Text Available In this work we present a topological map building and localization system for mobile robots based on global appearance of visual information. We include a comparison and analysis of global-appearance techniques applied to wide-angle scenes in retrieval tasks. Next, we define multiscale analysis, which permits improving the association between images and extracting topological distances. Then, a topological map-building algorithm is proposed. At first, the algorithm has information only of some isolated positions of the navigation area in the form of nodes. Each node is composed of a collection of images that covers the complete field of view from a certain position. The algorithm solves the node retrieval and estimates their spatial arrangement. With these aims, it uses the visual information captured along some routes that cover the navigation area. As a result, the algorithm builds a graph that reflects the distribution and adjacency relations between nodes (map. After the map building, we also propose a route path estimation system. This algorithm takes advantage of the multiscale analysis. The accuracy in the pose estimation is not reduced to the nodes locations but also to intermediate positions between them. The algorithms have been tested using two different databases captured in real indoor environments under dynamic conditions.

  4. MARS GLOBAL SURVEYOR RAW DATA SET - CRUISE V1.0

    National Aeronautics and Space Administration — The Mars Global Surveyor (MGS) Radio Science (RS) Raw Data Archive (RDA) is a time-ordered collection of raw and partially processed data collected during the MGS...

  5. Mars Global Surveyor Data Analysis Program. Origins of Small Volcanic Cones: Eruption Mechanisms and Implications for Water on Mars

    Fagents, Sarah A.; Greeley, Ronald; Thordarson, Thorvaldur

    2002-01-01

    The goal of the proposed work was to determine the origins of small volcanic cones observed in Mars Global Surveyor (MGS) data, and their implications for regolith ice stores and magma volatile contents. For this 1-year study, our approach involved a combination of: Quantitative morphologic analysis and interpretation of Mars Orbiter Camera (MOC) and Mars Orbiter Laser Altimeter (MOLA) data; Numerical modeling of eruption processes responsible for producing the observed features; Fieldwork on terrestrial analogs in Iceland. Following this approach, this study succeeded in furthering our understanding of (i) the spatial and temporal distribution of near-surface water ice, as defined by the distribution and sizes of rootless volcanic cones ("pseudocraters"), and (ii) the properties, eruption conditions, and volatile contents of magmas producing primary vent cones.

  6. THERESA FRANCO INSPECTS THE SOLAR PANELS OF THE MARS GLOBAL SURVEYOR

    1996-01-01

    Theresa Franco of SPECTROLAB Inc. carefully inspects the solar panels of the Mars Global Surveyor spacecraft, undergoing preflight assembly and checkout in the Payload Hazardous Servicing Facility in KSC's Industrial Area. The four solar array panels will play a crucial role in the Mars Global Surveyor mission by providing the electrical power required to operate the spacecraft and its complement of scientific instruments. The Surveyor is slated for launch November 6 aboard a Delta II expendable launch vehicle. After arriving at the Red Planet in September 1997, the Surveyor will carry out an extensive study of Mars, gathering data about the planet's topography, magnetism, mineral composition and atmosphere.

  7. Constructing Consistent Multiscale Scenarios by Transdisciplinary Processes: the Case of Mountain Regions Facing Global Change

    Fridolin Simon. Brand

    2013-06-01

    Full Text Available Alpine regions in Europe, in particular, face demanding local challenges, e.g., the decline in the agriculture and timber industries, and are also prone to global changes, such as in climate, with potentially severe impacts on tourism. We focus on the Visp region in the Upper Valais, Switzerland, and ask how the process of stakeholder involvement in research practice can contribute to a better understanding of the specific challenges and future development of mountainous regions under global change. Based on a coupled human-environment system (HES perspective, we carried out a formative scenario analysis to develop a set of scenarios for the future directions of the Visp region. In addition, we linked these regional scenarios to context scenarios developed at the global and Swiss levels via an external consistency analysis. This method allows the coupling of both the scenario building process and the scenarios as such. We used a functional-dynamic approach to theory-practice cooperation, i.e., the involvement of key stakeholders from, for example, tourism, forestry, and administration, differed in type and intensity during the steps of the research process. In our study, we experienced strong problem awareness among the stakeholders concerning the impacts of global change and local challenges. The guiding research question was commonly defined and problem ownership was more or less balanced. We arrived at six multiscale scenarios that open up future trajectories for the Visp region, and present generic strategies to cope with global and local challenges. The results show that local identity, spatial planning, community budget, and demographic development are important steering elements in the region's future development. We suggest that method-guided transdisciplinary processes result in a richer picture and a more systemic understanding, which enable a discussion of critical and surprising issues.

  8. Mars Global Digital Dune Database (MGD3): Global dune distribution and wind pattern observations

    Hayward, Rosalyn K.; Fenton, Lori; Titus, Timothy N.

    2014-01-01

    The Mars Global Digital Dune Database (MGD3) is complete and now extends from 90°N to 90°S latitude. The recently released south pole (SP) portion (MC-30) of MGD3 adds ∼60,000 km2 of medium to large-size dark dune fields and ∼15,000 km2 of sand deposits and smaller dune fields to the previously released equatorial (EQ, ∼70,000 km2), and north pole (NP, ∼845,000 km2) portions of the database, bringing the global total to ∼975,000 km2. Nearly all NP dunes are part of large sand seas, while the majority of EQ and SP dune fields are individual dune fields located in craters. Despite the differences between Mars and Earth, their dune and dune field morphologies are strikingly similar. Bullseye dune fields, named for their concentric ring pattern, are the exception, possibly owing their distinctive appearance to winds that are unique to the crater environment. Ground-based wind directions are derived from slipface (SF) orientation and dune centroid azimuth (DCA), a measure of the relative location of a dune field inside a crater. SF and DCA often preserve evidence of different wind directions, suggesting the importance of local, topographically influenced winds. In general however, ground-based wind directions are broadly consistent with expected global patterns, such as polar easterlies. Intriguingly, between 40°S and 80°S latitude both SF and DCA preserve their strongest, though different, dominant wind direction, with transport toward the west and east for SF-derived winds and toward the north and west for DCA-derived winds.

  9. Mars

    Day, Trevor

    2006-01-01

    Discusses the fundamental facts concerning this mysterious planet, including its mass, size, and atmosphere, as well as the various missions that helped planetary scientists document the geological history of Mars. This volume also describes Mars'' seasons with their surface effects on the planet and how they have changed over time.

  10. Seasonal Water Transport in the Atmosphere of Mars: Applications of a Mars General Circulation Model Using Mars Global Surveyor Data

    Hollingsworth, Jeffery L.; Bridger, Alison F. C.; Haberle, Robert M.

    1999-01-01

    This is a Final Report for a Joint Research Interchange (JRI) between NASA Ames Research Center and San Jose State University, Department of Meteorology. We present below a summary of progress made during the duration of this JRI. The focus of this JRI has been to investigate seasonal water vapor transport in the atmosphere of Mars and its effects on the planet's present climate. To this end, the primary task has been to adapt a new dynamical processor for the adiabatic tendencies of the atmospheric circulation into the NASA Ames Mars general circulation model (MGCM). Using identical boundary and initial conditions, several comparative tests between the new and old MGCMs have been performed and the nature of the simulated circulations have been diagnosed. With confidence that the updated version of the Ames MGCM produces quite similar mean and eddy circulation statistics, the new climate model is well poised as a tool to pursue fundamental questions related to the spatial and seasonal variations of atmospheric water vapor on Mars, and to explore exchanges of water with non-atmospheric reservoirs and transport within its atmosphere. In particular, the role of surface sources and sinks can be explored, the range of water-vapor saturation altitudes can be investigated, and plausible precipitation mechanisms can be studied, for a range of atmospheric dust loadings. Such future investigations can contribute to a comprehensive study of surface inventories, exchange mechanisms, and the relative importance of atmospheric transport Mars' water cycle. A listing of presentations made and manuscripts submitted during the course of this project is provided.

  11. A Globally Stable Lyapunov Pointing and Rate Controller for the Magnetospheric MultiScale Mission (MMS)

    Shah, Neerav

    2011-01-01

    The Magnetospheric MultiScale Mission (MMS) is scheduled to launch in late 2014. Its primary goal is to discover the fundamental plasma physics processes of reconnection in the Earth's magnetosphere. Each of the four MMS spacecraft is spin-stabilized at a nominal rate of 3 RPM. Traditional spin-stabilized spacecraft have used a number of separate modes to control nutation, spin rate, and precession. To reduce the number of modes and simplify operations, the Delta-H control mode is designed to accomplish nutation control, spin rate control, and precession control simultaneously. A nonlinear design technique, Lyapunov's method, is used to design the Delta-H control mode. A global spin rate controller selected as the baseline controller for MMS, proved to be insufficient due to an ambiguity in the attitude. Lyapunov's design method was used to solve this ambiguity, resulting in a controller that meets the design goals. Simulation results show the advantage of the pointing and rate controller for maneuvers larger than 90 deg and provide insight into the performance of this controller.

  12. Mars

    Payment, Simone

    2017-01-01

    This curriculum-based, fun, and approachable book offers everything young readers need to know to begin their study of the Red Planet. They will learn about the fundamental aspects of the Mars, including its size, mass, surface features, interior, orbit, and spin. Further, they will learn about the history of the missions to Mars, including the Viking spacecraft and the Curiosity and MAVEN rovers. Finally, readers will learn about why scientists think there's a chance that Mars is or was suitable for life. With stunning imagery from NASA itself, readers will have a front seat-view of the missi

  13. Dry deposition velocities in the global multi-scale CTM MOCAGE

    Michou, M.; Peuch, V.-H.

    2003-04-01

    Surface exchanges considered in the MOCAGE multiscale Chemistry and Transport Model (CTM) of Météo-France include dry deposition of gaseous species. To compute realistic time-dependent fluxes at the surface, a 2D interface between MOCAGE and ARPEGE, the French operational numerical weather prediction model, has been developed. Dry deposition of species including ozone, sulfur dioxide, nitrogen-containing compounds, long-lived and short-lived intermediates organic compounds, have been parameterised according to the [Wesely, 1989] scheme. A number of modifications has been made, for instance concerning the deposition against wet surfaces. The formulation of the aerodynamic resistance follows [Louis, 1979], and that of the stomatal resistance, the Interaction Soil Biosphere Atmosphere (ISBA) Météo-France scheme. Resistances are computed using the surface meteorological fields obtained from the analyses or forecasts of ARPEGE. Vegetation fields such as the Leaf Area Index are prescribed with a one-degree spatial resolution at the global scale, and a five-minute resolution over Europe. Calculated dry deposition velocities of ozone, sulfur dioxide and nitric acid have been evaluated against field experimental data at various locations around the world, from tropical regions, rain forest or savannah over Central Africa and Amazonia (EXPRESSO and LBA campaigns), to Mediterranean regions, including forested and crop sites (ESCOMPTE campaign), and temperate areas (deciduous and evergreen forests). Hourly values, monthly and seasonal means have been examined, as well as the impact of the model resolution, from 2 degrees over the globe to 0.08 degrees over regional domains. The contributions to the global budget of ozone of the deposition fluxes in these different regions of the globe will be also presented.

  14. Mars Global Surveyor Ka-Band Frequency Data Analysis

    Morabito, D.; Butman, S.; Shambayati, S.

    2000-01-01

    The Mars Global Surveyor (MGS) spacecraft, launched on November 7, 1996, carries an experimental space-to-ground telecommunications link at Ka-band (32 GHz) along with the primary X-band (8.4 GHz) downlink. The signals are simultaneously transmitted from a 1.5-in diameter parabolic high gain antenna (HGA) on MGS and received by a beam-waveguide (BWG) R&D 34-meter antenna located in NASA's Goldstone Deep Space Network (DSN) complex near Barstow, California. The projected 5-dB link advantage of Ka-band relative to X-band was confirmed in previous reports using measurements of MGS signal strength data acquired during the first two years of the link experiment from December 1996 to December 1998. Analysis of X-band and Ka-band frequency data and difference frequency (fx-fka)/3.8 data will be presented here. On board the spacecraft, a low-power sample of the X-band downlink from the transponder is upconverted to 32 GHz, the Ka-band frequency, amplified to I-W using a Solid State Power Amplifier, and radiated from the dual X/Ka HGA. The X-band signal is amplified by one of two 25 W TWTAs. An upconverter first downconverts the 8.42 GHz X-band signal to 8 GHz and then multiplies using a X4 multiplier producing the 32 GHz Ka-band frequency. The frequency source selection is performed by an RF switch which can be commanded to select a VCO (Voltage Controlled Oscillator) or USO (Ultra-Stable Oscillator) reference. The Ka-band frequency can be either coherent with the X-band downlink reference or a hybrid combination of the USO and VCO derived frequencies. The data in this study were chosen such that the Ka-band signal is purely coherent with the X-band signal, that is the downconverter is driven by the same frequency source as the X-band downlink). The ground station used to acquire the data is DSS-13, a 34-meter BWG antenna which incorporates a series of mirrors inside beam waveguide tubes which guide the energy to a subterranean pedestal room, providing a stable environment

  15. Description of the University of Auckland Global Mars Mesoscale Meteorological Model (GM4)

    Wing, D. R.; Austin, G. L.

    2005-08-01

    The University of Auckland Global Mars Mesoscale Meteorological Model (GM4) is a numerical weather prediction model of the Martian atmosphere that has been developed through the conversion of the Penn State University / National Center for Atmospheric Research fifth generation mesoscale model (MM5). The global aspect of this model is self consistent, overlapping, and forms a continuous domain around the entire planet, removing the need to provide boundary conditions other than at initialisation, yielding independence from the constraint of a Mars general circulation model. The brief overview of the model will be given, outlining the key physical processes and setup of the model. Comparison between data collected from Mars Pathfinder during its 1997 mission and simulated conditions using GM4 have been performed. Diurnal temperature variation as predicted by the model shows very good correspondence with the surface truth data, to within 5 K for the majority of the diurnal cycle. Mars Viking Data is also compared with the model, with good agreement. As a further means of validation for the model, various seasonal comparisons of surface and vertical atmospheric structure are conducted with the European Space Agency AOPP/LMD Mars Climate Database. Selected simulations over regions of interest will also be presented.

  16. Energetic particles detected by the Electron Reflectometer instrument on the Mars Global Surveyor, 1999-2006

    Delory, Gregory T.; Luhmann, Janet G.; Brain, David

    2012-01-01

    events at Mars associated with solar flares and coronal mass ejections, which includes the identification of interplanetary shocks. MGS observations of energetic particles at varying geometries between the Earth and Mars that include shocks produced by halo, limb, and backsided events provide a unique......We report the observation of galactic cosmic rays and solar energetic particles by the Electron Reflectometer instrument aboard the Mars Global Surveyor (MGS) spacecraft from May of 1999 to the mission conclusion in November 2006. Originally designed to detect low-energy electrons, the Electron...... recorded high energy galactic cosmic rays with similar to 45% efficiency. Comparisons of this data to galactic cosmic ray proton fluxes obtained from the Advanced Composition Explorer yield agreement to within 10% and reveal the expected solar cycle modulation as well as shorter timescale variations. Solar...

  17. Age of the Mars Global Northerly Slope: Evidence From Utopia Planitia

    McGill, George E.

    2002-01-01

    Recent results from the Mars Orbiter Laser Altimeter (MOLA) experiment on Mars Global Surveyor (MGS) indicate that most of Mars is characterized by a very gentle, roughly northerly slope. Detailed mapping in north-central Arabia Terra combined with superposition relations and crater counts indicate that, in that region at least, this northerly slope must have been formed no later than Late Hesperian, with the most likely time of formation being Late Hesperian. Current research in Utopia Planitia intended as a test of extant models for the formation of giant polygons has turned up good evidence for a Late Hesperian age for the northerly tilt in this region as well, as will be discussed.

  18. Hourly forecasting of global solar radiation based on multiscale decomposition methods: A hybrid approach

    Monjoly, Stéphanie; André, Maïna; Calif, Rudy; Soubdhan, Ted

    2017-01-01

    This paper introduces a new approach for the forecasting of solar radiation series at 1 h ahead. We investigated on several techniques of multiscale decomposition of clear sky index K_c data such as Empirical Mode Decomposition (EMD), Ensemble Empirical Mode Decomposition (EEMD) and Wavelet Decomposition. From these differents methods, we built 11 decomposition components and 1 residu signal presenting different time scales. We performed classic forecasting models based on linear method (Autoregressive process AR) and a non linear method (Neural Network model). The choice of forecasting method is adaptative on the characteristic of each component. Hence, we proposed a modeling process which is built from a hybrid structure according to the defined flowchart. An analysis of predictive performances for solar forecasting from the different multiscale decompositions and forecast models is presented. From multiscale decomposition, the solar forecast accuracy is significantly improved, particularly using the wavelet decomposition method. Moreover, multistep forecasting with the proposed hybrid method resulted in additional improvement. For example, in terms of RMSE error, the obtained forecasting with the classical NN model is about 25.86%, this error decrease to 16.91% with the EMD-Hybrid Model, 14.06% with the EEMD-Hybid model and to 7.86% with the WD-Hybrid Model. - Highlights: • Hourly forecasting of GHI in tropical climate with many cloud formation processes. • Clear sky Index decomposition using three multiscale decomposition methods. • Combination of multiscale decomposition methods with AR-NN models to predict GHI. • Comparison of the proposed hybrid model with the classical models (AR, NN). • Best results using Wavelet-Hybrid model in comparison with classical models.

  19. Seasonal and global behavior of water vapor in the Mars atmosphere: Complete global results of the Viking atmospheric water detector experiment

    Jakosky, B.M.; Farmer, C.B.

    1982-01-01

    The water vapor content of the Mars atmosphere was measured from the Viking Orbiter Mars Atmospheric Water Detectors (MAWD) for a period of more than 1 Martian year, from June 1976 through April 1979. Results are presented in the form of global maps of column abundance for 24 periods throughout each Mars year. The data reduction incorporates spatial and seasonal variations in surface pressure and supplements earlier published versions of less complete data

  20. GEM-AQ/EC, an on-line global multi-scale chemical weather modelling system: model development and evaluation of global aerosol climatology

    S. L. Gong

    2012-09-01

    Full Text Available A global air quality modeling system GEM-AQ/EC was developed by implementing tropospheric chemistry and aerosol processes on-line into the Global Environmental Multiscale weather prediction model – GEM. Due to the multi-scale features of the GEM, the integrated model, GEM-AQ/EC, is able to investigate chemical weather at scales from global to urban domains. The current chemical mechanism is comprised of 50 gas-phase species, 116 chemical and 19 photolysis reactions, and is complemented by a sectional aerosol module CAM (The Canadian Aerosol Module with 5 aerosols types: sulphate, black carbon, organic carbon, sea-salt and soil dust. Monthly emission inventories of black carbon and organic carbon from boreal and temperate vegetation fires were assembled using the most reliable areas burned datasets by countries, from statistical databases and derived from remote sensing products of 1995–2004. The model was run for ten years from from 1995–2004 with re-analyzed meteorology on a global uniform 1° × 1° horizontal resolution domain and 28 hybrid levels extending up to 10 hPa. The simulating results were compared with various observations including surface network around the globe and satellite data. Regional features of global aerosols are reasonably captured including emission, surface concentrations and aerosol optical depth. For various types of aerosols, satisfactory correlations were achieved between modeled and observed with some degree of systematic bias possibly due to large uncertainties in the emissions used in this study. A global distribution of natural aerosol contributions to the total aerosols is obtained and compared with observations.

  1. Global warming and climate forcing by recent albedo changes on Mars

    Fenton, L.K.; Geissler, P.E.; Haberle, R.M.

    2007-01-01

    For hundreds of years, scientists have tracked the changing appearance of Mars, first by hand drawings and later by photographs. Because of this historical record, many classical albedo patterns have long been known to shift in appearance over time. Decadal variations of the martian surface albedo are generally attributed to removal and deposition of small amounts of relatively bright dust on the surface. Large swaths of the surface (up to 56 million km2) have been observed to darken or brighten by 10 per cent or more. It is unknown, however, how these albedo changes affect wind circulation, dust transport and the feedback between these processes and the martian climate. Here we present predictions from a Mars general circulation model, indicating that the observed interannual albedo alterations strongly influence the martian environment. Results indicate enhanced wind stress in recently darkened areas and decreased wind stress in brightened areas, producing a positive feedback system in which the albedo changes strengthen the winds that generate the changes. The simulations also predict a net annual global warming of surface air temperatures by ???0.65 K, enhancing dust lifting by increasing the likelihood of dust devil generation. The increase in global dust lifting by both wind stress and dust devils may affect the mechanisms that trigger large dust storm initiation, a poorly understood phenomenon, unique to Mars. In addition, predicted increases in summertime air temperatures at high southern latitudes would contribute to the rapid and steady scarp retreat that has been observed in the south polar residual ice for the past four Mars years. Our results suggest that documented albedo changes affect recent climate change and large-scale weather patterns on Mars, and thus albedo variations are a necessary component of future atmospheric and climate studies. ??2007 Nature Publishing Group.

  2. Global multi-scale segmentation of continental and coastal waters from the watersheds to the continental margins

    Laruelle, G. G.; Dü rr, H. H.; Lauerwald, R.; Hartmann, J.; Slomp, C. P.; Goossens, N.; Regnier, P. A. G.

    2013-01-01

    Past characterizations of the land-ocean continuum were constructed either from a continental perspective through an analysis of watershed river basin properties (COSCATs: COastal Segmentation and related CATchments) or from an oceanic perspective, through a regionalization of the proximal and distal continental margins (LMEs: large marine ecosystems). Here, we present a global-scale coastal segmentation, composed of three consistent levels, that includes the whole aquatic continuum with its riverine, estuarine and shelf sea components. Our work delineates comprehensive ensembles by harmonizing previous segmentations and typologies in order to retain the most important physical characteristics of both the land and shelf areas. The proposed multi-scale segmentation results in a distribution of global exorheic watersheds, estuaries and continental shelf seas among 45 major zones (MARCATS: MARgins and CATchments Segmentation) and 149 sub-units (COSCATs). Geographic and hydrologic parameters such as the surface area, volume and freshwater residence time are calculated for each coastal unit as well as different hypsometric profiles. Our analysis provides detailed insights into the distributions of coastal and continental shelf areas and how they connect with incoming riverine fluxes. The segmentation is also used to re-evaluate the global estuarine CO2 flux at the air-water interface combining global and regional average emission rates derived from local studies. © 2013 Author(s).

  3. Global multi-scale segmentation of continental and coastal waters from the watersheds to the continental margins

    G. G. Laruelle

    2013-05-01

    Full Text Available Past characterizations of the land–ocean continuum were constructed either from a continental perspective through an analysis of watershed river basin properties (COSCATs: COastal Segmentation and related CATchments or from an oceanic perspective, through a regionalization of the proximal and distal continental margins (LMEs: large marine ecosystems. Here, we present a global-scale coastal segmentation, composed of three consistent levels, that includes the whole aquatic continuum with its riverine, estuarine and shelf sea components. Our work delineates comprehensive ensembles by harmonizing previous segmentations and typologies in order to retain the most important physical characteristics of both the land and shelf areas. The proposed multi-scale segmentation results in a distribution of global exorheic watersheds, estuaries and continental shelf seas among 45 major zones (MARCATS: MARgins and CATchments Segmentation and 149 sub-units (COSCATs. Geographic and hydrologic parameters such as the surface area, volume and freshwater residence time are calculated for each coastal unit as well as different hypsometric profiles. Our analysis provides detailed insights into the distributions of coastal and continental shelf areas and how they connect with incoming riverine fluxes. The segmentation is also used to re-evaluate the global estuarine CO2 flux at the air–water interface combining global and regional average emission rates derived from local studies.

  4. Global multi-scale segmentation of continental and coastal waters from the watersheds to the continental margins

    Laruelle, G. G.

    2012-10-04

    Past characterizations of the land–ocean continuum were constructed either from a continental perspective through an analysis of watershed river basin properties (COSCATs: COastal Segmentation and related CATchments) or from an oceanic perspective, through a regionalization of the proximal and distal continental margins (LMEs: large marine ecosystems). Here, we present a global-scale coastal segmentation, composed of three consistent levels, that includes the whole aquatic continuum with its riverine, estuarine and shelf sea components. Our work delineates comprehensive ensembles by harmonizing previous segmentations and typologies in order to retain the most important physical characteristics of both the land and shelf areas. The proposed multi-scale segmentation results in a distribution of global exorheic watersheds, estuaries and continental shelf seas among 45 major zones (MARCATS: MARgins and CATchments Segmentation) and 149 sub-units (COSCATs). Geographic and hydrologic parameters such as the surface area, volume and freshwater residence time are calculated for each coastal unit as well as different hypsometric pro- files. Our analysis provides detailed insights into the distributions of coastal and continental shelf areas and how they connect with incoming riverine fluxes. The segmentation is also used to re-evaluate the global estuarine CO2 flux at the air–water interface combining global and regional average emission rates derived from local studies.

  5. Global multi-scale segmentation of continental and coastal waters from the watersheds to the continental margins

    Laruelle, G. G.

    2013-05-29

    Past characterizations of the land-ocean continuum were constructed either from a continental perspective through an analysis of watershed river basin properties (COSCATs: COastal Segmentation and related CATchments) or from an oceanic perspective, through a regionalization of the proximal and distal continental margins (LMEs: large marine ecosystems). Here, we present a global-scale coastal segmentation, composed of three consistent levels, that includes the whole aquatic continuum with its riverine, estuarine and shelf sea components. Our work delineates comprehensive ensembles by harmonizing previous segmentations and typologies in order to retain the most important physical characteristics of both the land and shelf areas. The proposed multi-scale segmentation results in a distribution of global exorheic watersheds, estuaries and continental shelf seas among 45 major zones (MARCATS: MARgins and CATchments Segmentation) and 149 sub-units (COSCATs). Geographic and hydrologic parameters such as the surface area, volume and freshwater residence time are calculated for each coastal unit as well as different hypsometric profiles. Our analysis provides detailed insights into the distributions of coastal and continental shelf areas and how they connect with incoming riverine fluxes. The segmentation is also used to re-evaluate the global estuarine CO2 flux at the air-water interface combining global and regional average emission rates derived from local studies. © 2013 Author(s).

  6. THE RELATIONSHIP BETWEEN THE SEPTEMBER 2017 MARS GLOBAL AURORA EVENT AND CRUSTAL MAGNETIC FIELDS

    Nasr, Camella-Rosa; Schneider, Nick; Connour, Kyle; Jain, Sonal; Deighan, Justin; Jakosky, Bruce; MAVEN/IUVS Team

    2018-01-01

    In September 2017, the Imaging UltraViolet Spectrograph (IUVS) on the MAVEN spacecraft observed global aurora on Mars caused by a surprisingly strong solar energetic particle event. Widespread “diffuse aurora” have previously been detected on Mars through more limited observations (Schneider et al., Science 350, (2015); DOI: 10.1126/science.aad0313), but recent observations established complete coverage of the observable portion of Mars’ nightside. The aurora was global due to Mars’s lack of a global magnetic field, which allowed energetic electrons from the Sun to directly precipitate into the atmosphere. On September 11th, IUVS detected aurora more than 25 times brighter than any prior IUVS observation, with high SNR detections of aurora at the limb and against the disk of the planet. Fainter auroral emission was seen around the nightside limb over 13 orbits spanning nearly 3 days.On September 14th, during the declining phase of the event, faint linear features and patches were detected by the spacecraft, which were higher than the noise floor, with a similar spatial distribution to “discrete aurora” patches observed on Mars by the SPICAM instrument on the Mars Express spacecraft (Bertaux et al., Nature 435, doi :10.1038/nature03603). Discrete aurora occur near areas of the crust affected by the magnetism left over from Mars’ once-strong dipole field. Emission is limited to regions of the crustal magnetic field where the field lines are likely to be open to solar wind interactions. Those regions are concentrated in Mars’ southern hemisphere centered on 180 degrees east longitude.We studied the localized emissions on 14 September to determine whether there might be a connection between the observed diffuse aurora event and discrete auroral processes. First, we investigated the localized emissions to confirm that the observed signal was consistent with expected auroral spectra. Second, their locations were projected on a map of the crustal magnetic

  7. Modeling and Monitoring Terrestrial Primary Production in a Changing Global Environment: Toward a Multiscale Synthesis of Observation and Simulation

    Shufen Pan

    2014-01-01

    Full Text Available There is a critical need to monitor and predict terrestrial primary production, the key indicator of ecosystem functioning, in a changing global environment. Here we provide a brief review of three major approaches to monitoring and predicting terrestrial primary production: (1 ground-based field measurements, (2 satellite-based observations, and (3 process-based ecosystem modelling. Much uncertainty exists in the multi-approach estimations of terrestrial gross primary production (GPP and net primary production (NPP. To improve the capacity of model simulation and prediction, it is essential to evaluate ecosystem models against ground and satellite-based measurements and observations. As a case, we have shown the performance of the dynamic land ecosystem model (DLEM at various scales from site to region to global. We also discuss how terrestrial primary production might respond to climate change and increasing atmospheric CO2 and uncertainties associated with model and data. Further progress in monitoring and predicting terrestrial primary production requires a multiscale synthesis of observations and model simulations. In the Anthropocene era in which human activity has indeed changed the Earth’s biosphere, therefore, it is essential to incorporate the socioeconomic component into terrestrial ecosystem models for accurately estimating and predicting terrestrial primary production in a changing global environment.

  8. Solar wind modulation of the Martian ionosphere observed by Mars Global Surveyor

    J.-S. Wang

    2004-06-01

    Full Text Available Electron density profiles in the Martian ionosphere observed by the radio occultation experiment on board Mars Global Surveyor have been analyzed to determine if the densities are influenced by the solar wind. Evidence is presented that the altitude of the maximum ionospheric electron density shows a positive correlation to the energetic proton flux in the solar wind. The solar wind modulation of the Martian ionosphere can be attributed to heating of the neutral atmosphere by the solar wind energetic proton precipitation. The modulation is observed to be most prominent at high solar zenith angles. It is argued that this is consistent with the proposed modulation mechanism.

  9. Simulating the Current Water Cycle with the NASA Ames Mars Global Climate Model

    Kahre, M. A.; Haberle, R. M.; Hollingsworth, J. L.; Brecht, A. S.; Urata, R. A.; Montmessin, F.

    2017-12-01

    The water cycle is a critical component of the current Mars climate system, and it is now widely recognized that water ice clouds significantly affect the nature of the simulated water cycle. Two processes are key to implementing clouds in a Mars global climate model (GCM): the microphysical processes of formation and dissipation, and their radiative effects on atmospheric heating/cooling rates. Together, these processes alter the thermal structure, change the atmospheric dynamics, and regulate inter-hemispheric transport. We have made considerable progress using the NASA Ames Mars GCM to simulate the current-day water cycle with radiatively active clouds. Cloud fields from our baseline simulation are in generally good agreement with observations. The predicted seasonal extent and peak IR optical depths are consistent MGS/TES observations. Additionally, the thermal response to the clouds in the aphelion cloud belt (ACB) is generally consistent with observations and other climate model predictions. Notably, there is a distinct gap in the predicted clouds over the North Residual Cap (NRC) during local summer, but the clouds reappear in this simulation over the NRC earlier than the observations indicate. Polar clouds are predicted near the seasonal CO2 ice caps, but the column thicknesses of these clouds are generally too thick compared to observations. Our baseline simulation is dry compared to MGS/TES-observed water vapor abundances, particularly in the tropics and subtropics. These areas of disagreement appear to be a consistent with other current water cycle GCMs. Future avenues of investigation will target improving our understanding of what controls the vertical extent of clouds and the apparent seasonal evolution of cloud particle sizes within the ACB.

  10. Constructing Consistent Multiscale Scenarios by Transdisciplinary Processes: the Case of Mountain Regions Facing Global Change

    Fridolin Simon. Brand; Roman Seidl; Quang Bao. Le; Julia Maria. Brändle; Roland Werner. Scholz

    2013-01-01

    Alpine regions in Europe, in particular, face demanding local challenges, e.g., the decline in the agriculture and timber industries, and are also prone to global changes, such as in climate, with potentially severe impacts on tourism. We focus on the Visp region in the Upper Valais, Switzerland, and ask how the process of stakeholder involvement in research practice can contribute to a better understanding of the specific challenges and future development of mountainous regions under global ...

  11. Updates on Modeling the Water Cycle with the NASA Ames Mars Global Climate Model

    Kahre, M. A.; Haberle, R. M.; Hollingsworth, J. L.; Montmessin, F.; Brecht, A. S.; Urata, R.; Klassen, D. R.; Wolff, M. J.

    2017-01-01

    Global Circulation Models (GCMs) have made steady progress in simulating the current Mars water cycle. It is now widely recognized that clouds are a critical component that can significantly affect the nature of the simulated water cycle. Two processes in particular are key to implementing clouds in a GCM: the microphysical processes of formation and dissipation, and their radiative effects on heating/ cooling rates. Together, these processes alter the thermal structure, change the dynamics, and regulate inter-hemispheric transport. We have made considerable progress representing these processes in the NASA Ames GCM, particularly in the presence of radiatively active water ice clouds. We present the current state of our group's water cycle modeling efforts, show results from selected simulations, highlight some of the issues, and discuss avenues for further investigation.­

  12. Mars Global Surveyor Radio Science Electron Density Profiles: Interannual Variability and Implications for the Neutral Atmosphere

    Bougher, S. W.; Engel, S.; Hinson, D. P.; Murphy, J. R.

    2003-01-01

    The Mars Global Surveyor (MGS) Radio Science (RS) experiment employs an ultrastable oscillator aboard the spacecraft. The signal from the oscillator to Earth is refracted by the Martian ionosphere, allowing retrieval of electron density profiles versus radius and geopotential. The present analysis is carried out on five sets of occultation measurements: (1) four obtained near northern summer solstice (Ls = 74-116, near aphelion) at high northern latitudes (64.7-77.6N), and (2) one set of profiles approaching equinox conditions (Ls = 135- 146) at high southern latitudes (64.7-69.1S). Electron density profiles (95 to 200 km) are examined over a narrow range of solar zenith angles (76.5-86.9 degrees) for local true solar times of (1) 3-4 hours and (2) 12.1 hours. Variations spanning 1-Martian year are specifically examined in the Northern hemisphere.

  13. PFS/Mars Express first results: water vapour and carbon monoxide global distribution

    Ignatiev, N. I.; Titov, D. V.; Formisano, V.; Moroz, V. I.; Lellouch, E.; Encrenaz, Th.; Fouchet, T.; Grassi, D.; Giuranna, M.; Atreya, S.; Pfs Team

    Planetary Fourier Spectrometer onboard Mars Express, with its wide spectral range (1.2--45 um) and high spectral resolution (1.4 cm-1), makes it possible to study in a self-consistent manner the Martian atmosphere by means of simultaneous analysis of spectral features in several spectral regions. As concerned small species, we observe 30--50, 6.3, 2.56, 1.87 and 1.38 μ m H2O bands, and 4.7 and 2.35 μ m CO bands. The most favourable, with respect to the instrument performance, 2.56 μ m H2O and 4.7 μ m CO bands, are used to study the variations of column abundance of water vapour and carbon monoxide on a global scale from pole to pole. All necessary atmospheric parameters, namely temperature profiles, surface pressure, and dust density are obtained from the same spectra, whenever possible.

  14. Bringing global gyrokinetic turbulence simulations to the transport timescale using a multiscale approach

    Parker, Jeffrey; Lodestro, Lynda; Told, Daniel; Merlo, Gabriele; Ricketson, Lee; Campos, Alejandro; Jenko, Frank; Hittinger, Jeffrey

    2017-10-01

    Predictive whole-device simulation models will play an increasingly important role in ensuring the success of fusion experiments and accelerating the development of fusion energy. In the core of tokamak plasmas, a separation of timescales between turbulence and transport makes a single direct simulation of both processes computationally expensive. We present the first demonstration of a multiple-timescale method coupling global gyrokinetic simulations with a transport solver to calculate the self-consistent, steady-state temperature profile. Initial results are highly encouraging, with the coupling method appearing robust to the difficult problem of turbulent fluctuations. The method holds potential for integrating first-principles turbulence simulations into whole-device models and advancing the understanding of global plasma behavior. Work supported by US DOE under Contract DE-AC52-07NA27344 and the Exascale Computing Project (17-SC-20-SC).

  15. Bringing global gyrokinetic turbulence simulations to the transport timescale using a multiscale approach

    Parker, Jeffrey B.; LoDestro, Lynda L.; Told, Daniel; Merlo, Gabriele; Ricketson, Lee F.; Campos, Alejandro; Jenko, Frank; Hittinger, Jeffrey A. F.

    2018-05-01

    The vast separation dividing the characteristic times of energy confinement and turbulence in the core of toroidal plasmas makes first-principles prediction on long timescales extremely challenging. Here we report the demonstration of a multiple-timescale method that enables coupling global gyrokinetic simulations with a transport solver to calculate the evolution of the self-consistent temperature profile. This method, which exhibits resiliency to the intrinsic fluctuations arising in turbulence simulations, holds potential for integrating nonlocal gyrokinetic turbulence simulations into predictive, whole-device models.

  16. Development OF A Multi-Scale Framework for Mapping Global Evapotranspiration

    Hain, Christopher R.; Anderson, Martha C.; Schull, Mitchell; Neale, Christopher; Zhan, Xiwu

    2017-01-01

    As the worlds water resources come under increasing tension due to dual stressors of climate change and population growth, accurate knowledge of water consumption through evapotranspiration (ET) over a range in spatial scales will be critical in developing adaptation strategies. Remote sensing methods for monitoring consumptive water use (e.g, ET) are becoming increasingly important, especially in areas of significant water and food insecurity. One method to estimate ET from satellite-based methods, the Atmosphere Land Exchange Inverse (ALEXI) model uses the change in mid-morning land surface temperature to estimate the partitioning of sensible and latent heat fluxes which are then used to estimate daily ET. This presentation will outline several recent enhancements to the ALEXI modeling system, with a focus on global ET and drought monitoring.

  17. Multi-scales analysis of the global change impact on the diversity of the aphid communities

    Hulle, M.

    2007-01-01

    The primary objective of this project is to investigate the effects of global change on the biodiversity of aphid communities in Western Europe. Biodiversity has been examined at 3 levels: total number of species, phenology and reproductive strategy. Data were provided by EXAMINE, the European suction traps network which has been now operating for 35 years. 392 different species have been identified. At each location, total number of species has been regularly increasing, one additional species being caught every 1 or 2 years depending on location. This is due to introduced species but also to warming which favours rare species. No general trend of increasing density has been detected, but phenological earliness of almost all species (annual date of first appearance in suction traps) is strongly correlated with temperature and especially with mean daily temperature (during more or less long periods of time lying principally in February and March) or number of days below 0 C. Strong relationships between aphid phenology and environmental variables have been found and there is strong discrimination between species with different life cycle strategies, and between species feeding on herbs and trees, suggesting the possible value of trait-based groupings in predicting responses to environmental changes. These preliminary results suggest that 1) biodiversity has increased during the last decades; 2) there is a pool of species among which some of them reach a detectable density only during years where temperatures are high enough; 3) a set of newly introduced species succeed in settling being favoured by warming and 4) phenology of aphids is expected to advance and their abundance to increase with temperature, and the possible role of natural enemies to regulate abundant species is discussed. (author)

  18. Geologic history of the polar regions of Mars based on Mars Global survey data. I. Noachian and Hesperian Periods

    Tanaka, K.L.; Kolb, E.J.

    2001-01-01

    During the Noachian Period, the south polar region of Mars underwent intense cratering, construction of three groups of volcanoes, widespread contractional deformation, resurfacing of low areas, and local dissection of valley networks; no evidence for polar deposits, ice sheets, or glaciation is recognized. South polar Hesperian geology is broadly characterized by waning impacts, volcanism, and tectonism. Emplacement of the polar Dorsa Argentea Formation (DAF) occurred during the Hesperian Period. Mars Orbiter Laser Altimeter topographic data and Mars Orbiter Camera images elucidate stratigraphic, morphologic, and topographic relations, permitting the dividing of the DAF into eight members, which surround and underlie about half of the Amazonian south polar layered deposits. The lobate fronts and lack of typical volcanic-flow morphology of the six plains units indicate that they may be made up of debris flows. We think that these flows, tens of meters to 200 m thick, may have originated by the discharge of huge volumes of slurry fluidized by ground water or liquid CO2, perhaps triggered by local impacts, igneous activity, or basal melting beneath polar deposits. The cavi and rugged members include irregular depressions that penetrate the subsurface; some of the pits have raised rims. The depressions may have formed by collapse due to expulsion of subsurface material in which local explosive activity built up the raised rims. Further, smaller eruptions of volatile-rich material may have resulted in narrow, sinuous channel deposits within aggrading fine-grained unconsolidated material perhaps produced by gaseous discharge of subsurface volatiles; preferential erosion of the latter material could have produced the Dorsa Argentea-type ginuous ridges associated mainly with the DAF. Alternatively, the ridges may be eskers, but the lack of associated glacial and fluvial morphologies casts doubt on this interpretation. The knobby, degraded materials forming Scandia Colles

  19. Remote Sensing of Mars: Detection of Impact Craters on the Mars Global Surveyor DTM by Integrating Edge- and Region-Based Algorithms

    Athanassas, C. D.; Vaiopoulos, A.; Kolokoussis, P.; Argialas, D.

    2018-03-01

    This study integrates two different computer vision approaches, namely the circular Hough transform (CHT) and the determinant of Hessian (DoH), to detect automatically the largest number possible of craters of any size on the digital terrain model (DTM) generated by the Mars Global Surveyor mission. Specifically, application of the standard version of CHT to the DTM captured a great number of craters with diameter smaller than 50 km only, failing to capture larger craters. On the other hand, DoH was successful in detecting craters that were undetected by CHT, but its performance was deterred by the irregularity of the topographic surface encompassed: strongly undulated and inclined (trended) topographies hindered crater detection. When run on a de-trended DTM (and keeping the topology unaltered) DoH scored higher. Current results, although not optimal, encourage combined use of CHT and DoH for routine crater detection undertakings.

  20. A Basketball Court-Size Global Map of Mars for Education and Public Outreach

    Hill, J. R.; Christensen, P. R.

    2017-12-01

    The Thermal Emission Imaging System (THEMIS) onboard the 2001 Mars Odyssey spacecraft has acquired over 220,000 infrared images of the Martian surface at a resolution of 100 m/pixel since the start of science operations in February 2002. A global map was previously developed by mosaicking together over 24,000 high-quality full-resolution THEMIS daytime infrared images. Although the resulting map has been extremely valuable for scientific and mission operations applications, it has been difficult to communicate this value to students, citizen scientists and the general public, since their interactions with the map have been limited to computer-based geographic information system (GIS) interfaces. We determined that, in order to better communicate the value and importance of mapping the entire Martian surface at this resolution, people need to be able to physically interact with the map and experience its full scale. Therefore, the THEMIS Day IR Global Mosaic with Colorized MOLA Elevation will be printed on a 45ft x 90ft vinyl mat, which will allow observers to walk across and physically experience the map at approximately full resolution (printed at 200 pixels per inch). The size of the map was chosen to fit on a standard high school basketball court, so that a large number of schools will have a sufficiently large indoor surface on which to display the map for education events. The vinyl material and printing process selected for the map have been proven to be wear-resistant in similar applications, as long as everyone who walks on the map wears socks or similarly soft foot coverings. In order to make transportation easier, the map will be printed in two 45ft x 45ft sections, which will be joined together at events to create the full 45ft x 90ft map. The final stages of the map production will take place in early fall 2017, followed by initial education events at Arizona State University and local schools to test the educational activities associated with the map

  1. On the global and regional properties of the Mars gravitational figure

    Meshcheryakov, G.A.; Tserklevich, A.L.

    1978-01-01

    The investigations of the Mars gravitational figure (areoid) on the base of gravitational field models, suggested by Jordan, Born, Rizenberg and Sjegren have been carried out. Level surfaces are determined by the iteration method, suggested by G.A. Mescheryakov. The maps of the Mars areoid surface are built up. Regional peculiarities of the Mars gravitational figure are shortly considered. A close connection of the areoid surface and topographical surface of the planet is shown. Correlation coefficient between radii-vectors of the areoid and the topographical surface equals 0.96. Latitudinal correlation functions of areoid and relief of the Mars coincide; longitudinal ones little differ from them and only with longitude more than 70 deg they begin to diverge

  2. Multiscale comparison of GPM radar and passive microwave precipitation fields over oceans and land: effective resolution and global/regional/local diagnostics for improving retrieval algorithms

    Guilloteau, C.; Foufoula-Georgiou, E.; Kummerow, C.; Kirstetter, P. E.

    2017-12-01

    A multiscale approach is used to compare precipitation fields retrieved from GMI using the last version of the GPROF algorithm (GPROF-2017) to the DPR fields all over the globe. Using a wavelet-based spectral analysis, which renders the multi-scale decompositions of the original fields independent of each other spatially and across scales, we quantitatively assess the various scales of variability of the retrieved fields, and thus define the spatially-variable "effective resolution" (ER) of the retrievals. Globally, a strong agreement is found between passive microwave and radar patterns at scales coarser than 80km. Over oceans the patterns match down to the 20km scale. Over land, comparison statistics are spatially heterogeneous. In most areas a strong discrepancy is observed between passive microwave and radar patterns at scales finer than 40-80km. The comparison is also supported by ground-based observations over the continental US derived from the NOAA/NSSL MRMS suite of products. While larger discrepancies over land than over oceans are classically explained by land complex surface emissivity perturbing the passive microwave retrieval, other factors are investigated here, such as intricate differences in the storm structure over oceans and land. Differences in term of statistical properties (PDF of intensities and spatial organization) of precipitation fields over land and oceans are assessed from radar data, as well as differences in the relation between the 89GHz brightness temperature and precipitation. Moreover, the multiscale approach allows quantifying the part of discrepancies caused by miss-match of the location of intense cells and instrument-related geometric effects. The objective is to diagnose shortcomings of current retrieval algorithms such that targeted improvements can be made to achieve over land the same retrieval performance as over oceans.

  3. Global structure and composition of the martian atmosphere with SPICAM on Mars express

    Bertaux, Jean-Loup; Korablev, O.; Fonteyn, D.; Guibert, S.; Chassefière, E.; Lefèvre, F.; Dimarellis, E.; Dubois, J. P.; Hauchecorne, A.; Cabane, M.; Rannou, P.; Levasseur-Regourd, A. C.; Cernogora, G.; Quémerais, E.; Hermans, C.; Kockarts, G.; Lippens, C.; de Maziere, M.; Moreau, D.; Muller, C.; Neefs, E.; Simon, P. C.; Forget, F.; Hourdin, F.; Talagrand, O.; Moroz, V. I.; Rodin, A.; Sandel, B.; Stern, A.

    SPectroscopy for the Investigation of the Characteristics of the Atmosphere of Mars (SPICAM) Light, a light-weight (4.7 kg) UV-IR instrument to be flown on Mars Express orbiter, is dedicated to the study of the atmosphere and ionosphere of Mars. A UV spectrometer (118-320 nm, resolution 0.8 nm) is dedicated to nadir viewing, limb viewing and vertical profiling by stellar and solar occultation (3.8 kg). It addresses key issues about ozone, its coupling with H2O, aerosols, atmospheric vertical temperature structure and ionospheric studies. UV observations of the upper atmosphere will allow studies of the ionosphere through the emissions of CO, CO+, and CO2+, and its direct interaction with the solar wind. An IR spectrometer (1.0-1.7 μm, resolution 0.5-1.2 nm) is dedicated primarily to nadir measurements of H2O abundances simultaneously with ozone measured in the UV, and to vertical profiling during solar occultation of H2O, CO2, and aerosols. The SPICAM Light near-IR sensor employs a pioneering technology acousto-optical tunable filter (AOTF), leading to a compact and light design. Overall, SPICAM Light is an ideal candidate for future orbiter studies of Mars, after Mars Express, in order to study the interannual variability of martian atmospheric processes. The potential contribution to a Mars International Reference Atmosphere is clear.

  4. Distributed multiscale computing

    Borgdorff, J.

    2014-01-01

    Multiscale models combine knowledge, data, and hypotheses from different scales. Simulating a multiscale model often requires extensive computation. This thesis evaluates distributing these computations, an approach termed distributed multiscale computing (DMC). First, the process of multiscale

  5. Foundations for a multiscale collaborative Earth model

    Afanasiev, M.; Peter, Daniel; Sager, K.; Simut, S.; Ermert, L.; Krischer, L.; Fichtner, A.

    2015-01-01

    . The CSEM as a computational framework is intended to help bridging the gap between local, regional and global tomography, and to contribute to the development of a global multiscale Earth model. While the current construction serves as a first proof

  6. Vertical profiles of Mars 1.27 μm O2 dayglow from MRO CRISM limb spectra: Seasonal/global behaviors, comparisons to LMDGCM simulations, and a global definition for Mars water vapor profiles

    Todd Clancy, R.; Smith, Michael D.; Lefèvre, Franck; McConnochie, Timothy H.; Sandor, Brad J.; Wolff, Michael J.; Lee, Steven W.; Murchie, Scott L.; Toigo, Anthony D.; Nair, Hari; Navarro, Thomas

    2017-09-01

    Since July of 2009, The Compact Reconnaissance Imaging Spectral Mapper (CRISM) onboard the Mars Reconnaissance Orbiter (MRO) has periodically obtained pole-to-pole observations (i.e., full MRO orbits) of limb scanned visible/near IR spectra (λ = 0.4 - 4.0 μ m, △λ ∼ 10 nm- Murchie et al., 2007). These CRISM limb observations support the first seasonally and spatially extensive set of Mars 1.27 μm O2(1△g) dayglow profile retrievals (∼ 1100) over ≥ 8-80 km altitudes. Their comparison to Laboratoire de Météorologie Dynamique (LMD) global climate model (GCM) simulated O2(1△g) volume emission rate (VER) profiles, as a function of altitude, latitude, and season (solar longitude, Ls), supports several key conclusions regarding Mars atmospheric water vapor (which is derived from O2(1△g) emission rates), Mars O3, and the collisional de-excitation of O2(1△g) in the Mars CO2 atmosphere. Current (Navarro et al., 2014) LMDGCM simulations of Mars atmospheric water vapor fall 2-3 times below CRISM derived water vapor abundances at 20-40 km altitudes over low-to-mid latitudes in northern spring (Ls = 30-60°), and northern mid-to-high latitudes over northern summer (Ls = 60-140°). In contrast, LMDGCM simulated water vapor is 2-5 times greater than CRISM derived values at all latitudes and seasons above 40 km, within the aphelion cloud belt (ACB), and over high-southern to mid-southern latitudes in southern summer (Ls = 190-340°) at 15-35 km altitudes. Overall, the solstitial summer-to-winter hemisphere gradients in water vapor are reversed between the LMDGCM modeled versus the CRISM derived water vapor abundances above 10-30 km altitudes. LMDGCM-CRISM differences in water vapor profiles correlate with LMDGCM-CRISM differences in cloud mixing profiles; and likely reflect limitations in simulating cloud microphysics and radiative forcing, both of which restrict meridional transport of water from summer-to-winter hemispheres on Mars (Clancy et al., 1996

  7. Mars approach for global sensitivity analysis of differential equation models with applications to dynamics of influenza infection.

    Lee, Yeonok; Wu, Hulin

    2012-01-01

    Differential equation models are widely used for the study of natural phenomena in many fields. The study usually involves unknown factors such as initial conditions and/or parameters. It is important to investigate the impact of unknown factors (parameters and initial conditions) on model outputs in order to better understand the system the model represents. Apportioning the uncertainty (variation) of output variables of a model according to the input factors is referred to as sensitivity analysis. In this paper, we focus on the global sensitivity analysis of ordinary differential equation (ODE) models over a time period using the multivariate adaptive regression spline (MARS) as a meta model based on the concept of the variance of conditional expectation (VCE). We suggest to evaluate the VCE analytically using the MARS model structure of univariate tensor-product functions which is more computationally efficient. Our simulation studies show that the MARS model approach performs very well and helps to significantly reduce the computational cost. We present an application example of sensitivity analysis of ODE models for influenza infection to further illustrate the usefulness of the proposed method.

  8. Applying the global RCP-SSP-SPA scenario framework at sub-national scale: A multi-scale and participatory scenario approach.

    Kebede, Abiy S; Nicholls, Robert J; Allan, Andrew; Arto, Iñaki; Cazcarro, Ignacio; Fernandes, Jose A; Hill, Chris T; Hutton, Craig W; Kay, Susan; Lázár, Attila N; Macadam, Ian; Palmer, Matthew; Suckall, Natalie; Tompkins, Emma L; Vincent, Katharine; Whitehead, Paul W

    2018-09-01

    To better anticipate potential impacts of climate change, diverse information about the future is required, including climate, society and economy, and adaptation and mitigation. To address this need, a global RCP (Representative Concentration Pathways), SSP (Shared Socio-economic Pathways), and SPA (Shared climate Policy Assumptions) (RCP-SSP-SPA) scenario framework has been developed by the Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC-AR5). Application of this full global framework at sub-national scales introduces two key challenges: added complexity in capturing the multiple dimensions of change, and issues of scale. Perhaps for this reason, there are few such applications of this new framework. Here, we present an integrated multi-scale hybrid scenario approach that combines both expert-based and participatory methods. The framework has been developed and applied within the DECCMA 1 project with the purpose of exploring migration and adaptation in three deltas across West Africa and South Asia: (i) the Volta delta (Ghana), (ii) the Mahanadi delta (India), and (iii) the Ganges-Brahmaputra-Meghna (GBM) delta (Bangladesh/India). Using a climate scenario that encompasses a wide range of impacts (RCP8.5) combined with three SSP-based socio-economic scenarios (SSP2, SSP3, SSP5), we generate highly divergent and challenging scenario contexts across multiple scales against which robustness of the human and natural systems within the deltas are tested. In addition, we consider four distinct adaptation policy trajectories: Minimum intervention, Economic capacity expansion, System efficiency enhancement, and System restructuring, which describe alternative future bundles of adaptation actions/measures under different socio-economic trajectories. The paper highlights the importance of multi-scale (combined top-down and bottom-up) and participatory (joint expert-stakeholder) scenario methods for addressing uncertainty in adaptation decision

  9. Global Distribution of On-Set Diameters of Rampart Ejecta Craters on Mars: Their Implication to the History of Martian Water

    Boyce, Joseph M.; Roddy, David J.; Soderblom, Lawrence A.; Hare, Trent

    2000-01-01

    A global map is presented of on-set diameters of rampart craters. These craters are proposed to result from impact into wet targets. This map shows both global latitudinal and regional trends that are consistent with the climate and geologic history of Mars.

  10. Global distribution of bedrock exposures on Mars using THEMIS high-resolution thermal inertia

    Edwards, C.S.; Bandfield, J.L.; Christensen, P.R.; Fergason, R.L.

    2009-01-01

    We investigate high thermal inertia surfaces using the Mars Odyssey Thermal Emission Imaging System (THEMIS) nighttime temperature images (100 m/pixel spatial sampling). For this study, we interpret any pixel in a THEMIS image with a thermal inertia over 1200 J m-2 K-1 s-1/2 as "bedrock" which represents either in situ rock exposures or rock-dominated surfaces. Three distinct morphologies, ranked from most to least common, are associated with these high thermal inertia surfaces: (1) valley and crater walls associated with mass wasting and high surface slope angles; (2) floors of craters with diameters >25 km and containing melt or volcanics associated with larger, high-energy impacts; and (3) intercrater surfaces with compositions significantly more mafic than the surrounding regolith. In general, bedrock instances on Mars occur as small exposures (less than several square kilometers) situated in lower-albedo (inertia (>350 J m-2 K-1 s-1/2), and relatively dust-free (dust cover index <0.95) regions; however, there are instances that do not follow these generalizations. Most instances are concentrated in the southern highlands, with very few located at high latitudes (poleward of 45oN and 58oS), suggesting enhanced mechanical breakdown probably associated with permafrost. Overall, Mars has very little exposed bedrock with only 960 instances identified from 75oS to 75oN with likely <3500 km2 exposed, representing???1% of the total surface area. These data indicate that Mars has likely undergone large-scale surface processing and reworking, both chemically and mechanically, either destroying or masking a majority of the bedrock exposures on the planet. Copyright 2009 by the American Geophysical Union.

  11. Multi-Scale Governance of Sustainable Natural Resource Use—Challenges and Opportunities for Monitoring and Institutional Development at the National and Global Level

    Stefan Bringezu

    2016-08-01

    Full Text Available In a globalized economy, the use of natural resources is determined by the demand of modern production and consumption systems, and by infrastructure development. Sustainable natural resource use will require good governance and management based on sound scientific information, data and indicators. There is a rich literature on natural resource management, yet the national and global scale and macro-economic policy making has been underrepresented. We provide an overview of the scholarly literature on multi-scale governance of natural resources, focusing on the information required by relevant actors from local to global scale. Global natural resource use is largely determined by national, regional, and local policies. We observe that in recent decades, the development of public policies of natural resource use has been fostered by an “inspiration cycle” between the research, policy and statistics community, fostering social learning. Effective natural resource policies require adequate monitoring tools, in particular indicators for the use of materials, energy, land, and water as well as waste and GHG emissions of national economies. We summarize the state-of-the-art of the application of accounting methods and data sources for national material flow accounts and indicators, including territorial and product-life-cycle based approaches. We show how accounts on natural resource use can inform the Sustainable Development Goals (SDGs and argue that information on natural resource use, and in particular footprint indicators, will be indispensable for a consistent implementation of the SDGs. We recognize that improving the knowledge base for global natural resource use will require further institutional development including at national and international levels, for which we outline options.

  12. Multiscale Retinex

    Ana Belén Petro

    2014-04-01

    Full Text Available While the retinex theory aimed at explaining human color perception, its derivations have led to efficient algorithms enhancing local image contrast, thus permitting among other features, to "see in the shadows". Among these derived algorithms, Multiscale Retinex is probably the most successful center-surround image filter. In this paper, we offer an analysis and implementation of Multiscale Retinex. We point out and resolve some ambiguities of the method. In particular, we show that the important color correction final step of the method can be seriously improved. This analysis permits to come up with an automatic implementation of Multiscale Retinex which is as faithful as possible to the one described in the original paper. Overall, this implementation delivers excellent results and confirms the validity of Multiscale Retinex for image color restoration and contrast enhancement. Nevertheless, while the method parameters can be fixed, we show that a crucial choice must be left to the user, depending on the lightning condition of the image: the method must either be applied to each color independently if a color balance is required, or to the luminance only if the goal is to achieve local contrast enhancement. Thus, we propose two slightly different algorithms to deal with both cases.

  13. Simulation of spontaneous and variable global dust storms with the GFDL Mars GCM

    Basu, Shabari; Wilson, John; Richardson, Mark; Ingersoll, Andrew

    2006-01-01

    We report on the successful simulation of global dust storms in a general circulation model. The simulated storms develop spontaneously in multiyear simulations and exhibit significant interannual variability. The simulated storms produce dramatic increases in atmospheric dustiness, global-mean air temperatures, and atmospheric circulation intensity, in accord with observations. As with observed global storms, spontaneous initiation of storms in the model occurs in southern spring and summer,...

  14. Multiscale Simulation Framework for Coupled Fluid Flow and Mechanical Deformation

    Hou, Thomas [California Inst. of Technology (CalTech), Pasadena, CA (United States); Efendiev, Yalchin [Stanford Univ., CA (United States); Tchelepi, Hamdi [Texas A & M Univ., College Station, TX (United States); Durlofsky, Louis [Stanford Univ., CA (United States)

    2016-05-24

    Our work in this project is aimed at making fundamental advances in multiscale methods for flow and transport in highly heterogeneous porous media. The main thrust of this research is to develop a systematic multiscale analysis and efficient coarse-scale models that can capture global effects and extend existing multiscale approaches to problems with additional physics and uncertainties. A key emphasis is on problems without an apparent scale separation. Multiscale solution methods are currently under active investigation for the simulation of subsurface flow in heterogeneous formations. These procedures capture the effects of fine-scale permeability variations through the calculation of specialized coarse-scale basis functions. Most of the multiscale techniques presented to date employ localization approximations in the calculation of these basis functions. For some highly correlated (e.g., channelized) formations, however, global effects are important and these may need to be incorporated into the multiscale basis functions. Other challenging issues facing multiscale simulations are the extension of existing multiscale techniques to problems with additional physics, such as compressibility, capillary effects, etc. In our project, we explore the improvement of multiscale methods through the incorporation of additional (single-phase flow) information and the development of a general multiscale framework for flows in the presence of uncertainties, compressible flow and heterogeneous transport, and geomechanics. We have considered (1) adaptive local-global multiscale methods, (2) multiscale methods for the transport equation, (3) operator-based multiscale methods and solvers, (4) multiscale methods in the presence of uncertainties and applications, (5) multiscale finite element methods for high contrast porous media and their generalizations, and (6) multiscale methods for geomechanics.

  15. Multiscale analysis and computation for flows in heterogeneous media

    Efendiev, Yalchin [Texas A & M Univ., College Station, TX (United States); Hou, T. Y. [California Inst. of Technology (CalTech), Pasadena, CA (United States); Durlofsky, L. J. [Stanford Univ., CA (United States); Tchelepi, H. [Stanford Univ., CA (United States)

    2016-08-04

    Our work in this project is aimed at making fundamental advances in multiscale methods for flow and transport in highly heterogeneous porous media. The main thrust of this research is to develop a systematic multiscale analysis and efficient coarse-scale models that can capture global effects and extend existing multiscale approaches to problems with additional physics and uncertainties. A key emphasis is on problems without an apparent scale separation. Multiscale solution methods are currently under active investigation for the simulation of subsurface flow in heterogeneous formations. These procedures capture the effects of fine-scale permeability variations through the calculation of specialized coarse-scale basis functions. Most of the multiscale techniques presented to date employ localization approximations in the calculation of these basis functions. For some highly correlated (e.g., channelized) formations, however, global effects are important and these may need to be incorporated into the multiscale basis functions. Other challenging issues facing multiscale simulations are the extension of existing multiscale techniques to problems with additional physics, such as compressibility, capillary effects, etc. In our project, we explore the improvement of multiscale methods through the incorporation of additional (single-phase flow) information and the development of a general multiscale framework for flows in the presence of uncertainties, compressible flow and heterogeneous transport, and geomechanics. We have considered (1) adaptive local-global multiscale methods, (2) multiscale methods for the transport equation, (3) operator-based multiscale methods and solvers, (4) multiscale methods in the presence of uncertainties and applications, (5) multiscale finite element methods for high contrast porous media and their generalizations, and (6) multiscale methods for geomechanics. Below, we present a brief overview of each of these contributions.

  16. Global multi-scale segmentation of continental and coastal waters from the watersheds to the continental margins

    Laruelle, G. G.; Dü rr, H. H.; Lauerwald, R.; Hartmann, J.; Slomp, C. P.; Regnier, P. A. G.

    2012-01-01

    files. Our analysis provides detailed insights into the distributions of coastal and continental shelf areas and how they connect with incoming riverine fluxes. The segmentation is also used to re-evaluate the global estuarine CO2 flux at the air–water interface combining global and regional average emission rates derived from local studies.

  17. GEM-AQ, an on-line global multiscale chemical weather modelling system: model description and evaluation of gas phase chemistry processes

    J. W. Kaminski

    2008-06-01

    Full Text Available Tropospheric chemistry and air quality processes were implemented on-line in the Global Environmental Multiscale weather prediction model. The integrated model, GEM-AQ, was developed as a platform to investigate chemical weather at scales from global to urban. The current chemical mechanism is comprised of 50 gas-phase species, 116 chemical and 19 photolysis reactions, and is complemented by a sectional aerosol module with 5 aerosols types. All tracers are advected using the semi-Lagrangian scheme native to GEM. The vertical transport includes parameterized subgrid-scale turbulence and large scale deep convection. Dry deposition is included as a flux boundary condition in the vertical diffusion equation. Wet deposition of gas-phase species is treated in a simplified way, and only below-cloud scavenging is considered. The emissions used include yearly-averaged anthropogenic, and monthly-averaged biogenic, ocean, soil, and biomass burning emission fluxes, as well as NOx from lightning. In order to evaluate the ability to simulate seasonal variations and regional distributions of trace gases such as ozone, nitrogen dioxide and carbon monoxide, the model was run for a period of five years (2001–2005 on a global uniform 1.5°×1.5° horizontal resolution domain and 28 hybrid levels extending up to 10 hPa. Model results were compared with observations from satellites, aircraft measurement campaigns and balloon sondes. We find that GEM-AQ is able to capture the spatial details of the chemical fields in the middle and lower troposphere. The modelled ozone consistently shows good agreement with observations, except over tropical oceans. The comparison of carbon monoxide and nitrogen dioxide with satellite measurements emphasizes the need for more accurate, year-specific emissions fluxes for biomass burning and anthropogenic sources. Other species also compare well with available observations.

  18. Formation of mantle "lone plumes" in the global downwelling zone - A multiscale modelling of subduction-controlled plume generation beneath the South China Sea

    Zhang, Nan; Li, Zheng-Xiang

    2018-01-01

    It has been established that almost all known mantle plumes since the Mesozoic formed above the two lower mantle large low shear velocity provinces (LLSVPs). The Hainan plume is one of the rare exceptions in that instead of rising above the LLSVPs, it is located within the broad global mantle downwelling zone, therefore classified as a "lone plume". Here, we use the Hainan plume example to investigate the feasibility of such lone plumes being generated by subducting slabs in the mantle downwelling zone using 3D geodynamic modelling. Our geodynamic model has a high-resolution regional domain embedded in a relatively low resolution global domain, which is set up in an adaptive-mesh-refined, 3D mantle convection code ASPECT (Advanced Solver for Problems in Earth's ConvecTion). We use a recently published plate motion model to define the top mechanical boundary condition. Our modelling results suggest that cold slabs under the present-day Eurasia, formed from the Mesozoic subduction and closure of the Tethys oceans, have prevented deep mantle hot materials from moving to the South China Sea from regions north or west of the South China Sea. From the east side, the Western Pacific subduction systems started to promote the formation of a lower-mantle thermal-chemical pile in the vicinity of the future South China Sea region since 70 Ma ago. As the top of this lower-mantle thermal-chemical pile rises, it first moved to the west, and finally rested beneath the South China Sea. The presence of a thermochemical layer (possible the D″ layer) in the model helps stabilizing the plume root. Our modelling is the first implementation of multi-scale mesh in the regional model. It has been proved to be an effective way of modelling regional dynamics within a global plate motion and mantle dynamics background.

  19. Evolution of the global water cycle on Mars: The geological evidence

    Baker, V. R.; Gulick, V. C.

    1993-01-01

    The geological evidence for active water cycling early in the history of Mars (Noachian geological system or heavy bombardment) consists almost exclusively of fluvial valley networks in the heavily cratered uplands of the planet. It is commonly assumed that these landforms required explanation by atmospheric processes operating above the freezing point of water and at high pressure to allow rainfall and liquid surface runoff. However, it has also been documented that nearly all valley networks probably formed by subsurface outflow and sapping erosion involving groundwater outflow prior to surface-water flow. The prolonged ground-water flow also requires extensive water cycling to maintain hydraulic gradients, but is this done via rainfall recharge, as in terrestrial environments?

  20. Numerical Representation of Wintertime Near-Surface Inversions in the Arctic with a 2.5-km Version of the Global Environmental Multiscale (GEM) Model

    Dehghan, A.; Mariani, Z.; Gascon, G.; Bélair, S.; Milbrandt, J.; Joe, P. I.; Crawford, R.; Melo, S.

    2017-12-01

    Environment and Climate Change Canada (ECCC) is implementing a 2.5-km resolution version of the Global Environmental Multiscale (GEM) model over the Canadian Arctic. Radiosonde observations were used to evaluate the numerical representation of surface-based temperature inversion which is a major feature in the Arctic region. Arctic surface-based inversions are often created by imbalance between radiative cooling processes at surface and warm air advection above. This can have a significant effect on vertical mixing of pollutants and moisture, and ultimately, on cloud formation. It is therefore important to correctly predict the existence of surface inversions along with their characteristics (i.e., intensity and depth). Previous climatological studies showed that the frequency and intensity of surface-based inversions are larger during colder months in the Arctic. Therefore, surface-based inversions were estimated using radiosonde measurements during winter (December 2015 to February 2016) at Iqaluit (Nunavut, Canada). Results show that the inversion intensity can exceed 10 K with depths as large as 1 km. Preliminary evaluation of GEM outputs reveals that the model tends to underestimate the intensity of near-surface inversions, and in some cases, the model failed to predict an inversion. This study presents the factors contributing to this bias including surface temperature and snow cover.

  1. Description and Evaluation of the Multiscale Online Nonhydrostatic AtmospheRe CHemistry Model (NMMB-MONARCH) Version 1.0: Gas-Phase Chemistry at Global Scale

    Badia, Alba; Jorba, Oriol; Voulgarakis, Apostolos; Dabdub, Donald; Garcia-Pando, Carlos Perez; Hilboll, Andreas; Goncalves, Maria; Janjic, Zavisa

    2017-01-01

    This paper presents a comprehensive description and benchmark evaluation of the tropospheric gas-phase chemistry component of the Multiscale Online Nonhydrostatic AtmospheRe CHemistry model (NMMBMONARCH), formerly known as NMMB/BSC-CTM, that can be run on both regional and global domains. Here, we provide an extensive evaluation of a global annual cycle simulation using a variety of background surface stations (EMEP, WDCGG and CASTNET), ozonesondes (WOUDC, CMD and SHADOZ), aircraft data (MOZAIC and several campaigns), and satellite observations (SCIAMACHY and MOPITT).We also include an extensive discussion of our results in comparison to other state-of-the-art models. We note that in this study, we omitted aerosol processes and some natural emissions (lightning and volcano emissions). The model shows a realistic oxidative capacity across the globe. The seasonal cycle for CO is fairly well represented at different locations (correlations around 0.3-0.7 in surface concentrations), although concentrations are underestimated in spring and winter in the Northern Hemisphere, and are overestimated throughout the year at 800 and 500 hPa in the Southern Hemisphere. Nitrogen species are well represented in almost all locations, particularly NO2 in Europe (root mean square error - RMSE - below 5 ppb). The modeled vertical distributions of NOx and HNO3 are in excellent agreement with the observed values and the spatial and seasonal trends of tropospheric NO2 columns correspond well to observations from SCIAMACHY, capturing the highly polluted areas and the biomass burning cycle throughout the year. Over Asia, the model underestimates NOx from March to August, probably due to an underestimation of NOx emissions in the region. Overall, the comparison of the modeled CO and NO2 with MOPITT and SCIAMACHY observations emphasizes the need for more accurate emission rates from anthropogenic and biomass burning sources (i.e., specification of temporal variability).

  2. The distance between Mars and Venus: measuring global sex differences in personality.

    Del Giudice, Marco; Booth, Tom; Irwing, Paul

    2012-01-01

    Sex differences in personality are believed to be comparatively small. However, research in this area has suffered from significant methodological limitations. We advance a set of guidelines for overcoming those limitations: (a) measure personality with a higher resolution than that afforded by the Big Five; (b) estimate sex differences on latent factors; and (c) assess global sex differences with multivariate effect sizes. We then apply these guidelines to a large, representative adult sample, and obtain what is presently the best estimate of global sex differences in personality. Personality measures were obtained from a large US sample (N = 10,261) with the 16PF Questionnaire. Multigroup latent variable modeling was used to estimate sex differences on individual personality dimensions, which were then aggregated to yield a multivariate effect size (Mahalanobis D). We found a global effect size D = 2.71, corresponding to an overlap of only 10% between the male and female distributions. Even excluding the factor showing the largest univariate ES, the global effect size was D = 1.71 (24% overlap). These are extremely large differences by psychological standards. The idea that there are only minor differences between the personality profiles of males and females should be rejected as based on inadequate methodology.

  3. The GEM-Mars general circulation model for Mars: Description and evaluation

    Neary, L.; Daerden, F.

    2018-01-01

    GEM-Mars is a gridpoint-based three-dimensional general circulation model (GCM) of the Mars atmosphere extending from the surface to approximately 150 km based on the GEM (Global Environmental Multiscale) model, part of the operational weather forecasting and data assimilation system for Canada. After the initial modification for Mars, the model has undergone considerable changes. GEM-Mars is now based on GEM 4.2.0 and many physical parameterizations have been added for Mars-specific atmospheric processes and surface-atmosphere exchange. The model simulates interactive carbon dioxide-, dust-, water- and atmospheric chemistry cycles. Dust and water ice clouds are radiatively active. Size distributed dust is lifted by saltation and dust devils. The model includes 16 chemical species (CO2, Argon, N2, O2, CO, H2O, CH4, O3, O(1D), O, H, H2, OH, HO2, H2O2 and O2(a1Δg)) and has fully interactive photochemistry (15 reactions) and gas-phase chemistry (31 reactions). GEM-Mars provides a good simulation of the water and ozone cycles. A variety of other passive tracers can be included for dedicated studies, such as the emission of methane. The model has both a hydrostatic and non-hydrostatic formulation, and together with a flexible grid definition provides a single platform for simulations on a variety of horizontal scales. The model code is fully parallelized using OMP and MPI. Model results are evaluated by comparison to a selection of observations from instruments on the surface and in orbit, relating to atmosphere and surface temperature and pressure, dust and ice content, polar ice mass, polar argon, and global water and ozone vertical columns. GEM-Mars will play an integral part in the analysis and interpretation of data that is received by the NOMAD spectrometer on the ESA-Roskosmos ExoMars Trace Gas Orbiter. The present paper provides an overview of the current status and capabilities of the GEM-Mars model and lays the foundations for more in-depth studies in support

  4. Cars on Mars

    Landis, Geoffrey A.

    2002-01-01

    Mars is one of the most fascinating planets in the solar system, featuring an atmosphere, water, and enormous volcanoes and canyons. The Mars Pathfinder, Global Surveyor, and Odyssey missions mark the first wave of the Planet Earth's coming invasion of the red planet, changing our views of the past and future of the planet and the possibilities of life. Scientist and science-fiction writer Geoffrey A. Landis will present experiences on the Pathfinder mission, the challenges of using solar power on the surface of Mars, and present future missions to Mars such as the upcoming Mars Twin Rovers, which will launch two highly-capable vehicles in 2003 to explore the surface of Mars.

  5. Wet Mars, Dry Mars

    Fillingim, M. O.; Brain, D. A.; Peticolas, L. M.; Yan, D.; Fricke, K. W.; Thrall, L.

    2012-12-01

    The magnetic fields of the large terrestrial planets, Venus, Earth, and Mars, are all vastly different from each other. These differences can tell us a lot about the interior structure, interior history, and even give us clues to the atmospheric history of these planets. This poster highlights the third in a series of presentations that target school-age audiences with the overall goal of helping the audience visualize planetary magnetic field and understand how they can impact the climatic evolution of a planet. Our first presentation, "Goldilocks and the Three Planets," targeted to elementary school age audiences, focuses on the differences in the atmospheres of Venus, Earth, and Mars and the causes of the differences. The second presentation, "Lost on Mars (and Venus)," geared toward a middle school age audience, highlights the differences in the magnetic fields of these planets and what we can learn from these differences. Finally, in the third presentation, "Wet Mars, Dry Mars," targeted to high school age audiences and the focus of this poster, the emphasis is on the long term climatic affects of the presence or absence of a magnetic field using the contrasts between Earth and Mars. These presentations are given using visually engaging spherical displays in conjunction with hands-on activities and scientifically accurate 3D models of planetary magnetic fields. We will summarize the content of our presentations, discuss our lessons learned from evaluations, and show (pictures of) our hands-on activities and 3D models.

  6. Global Distribution of Shallow Water on Mars: Neutron Mapping of Summer-Time Surface by HEND/Odyssey

    Mitrofanov, I. G.; Litvak, M. L.; Kozyrev, A. S.; Sanin, A. B.; Tretyakov, V. I.; Boynton, W.; Hamara, D.; Shinohara, C.; Saunders, R. S.; Drake, D.

    2003-01-01

    Orbital mapping of induced neutrons and gamma-rays by Odyssey has recently successfully proven the applicability of nuclear methods for studying of the elementary composition of Martian upper-most subsurface. In particular, the suite of Gamma-Ray Spectrometer (GRS) has discovered the presence of large water-ice rich regions southward and northward on Mars. The data of neutron mapping of summer-time surface are presented below from the Russian High Energy Neutron Spectrometer (HEND), which is a part of GRS suite. These maps represent the content of water in the soil for summer season at Southern and Northern hemispheres, when the winter deposit of CO2 is absent on the surface. The seasonal evolution of CO2 coverage on Mars is the subject of the complementary paper.

  7. How relevant is heterogeneous chemistry on Mars? Strong tests via global mapping of water and ozone (sampled via O2 dayglow)

    Villanueva, Geronimo Luis; Mumma, Michael J.; Novak, Robert E.

    2015-11-01

    Ozone and water are powerful tracers of photochemical processes on Mars. Considering that water is a condensable with a multifaceted hydrological cycle and ozone is continuously being produced / destroyed on short-time scales, their maps can test the validity of current 3D photochemical and dynamical models. Comparisons of modern GCM models (e.g., Lefèvre et al. 2004) with certain datasets (e.g., Clancy et al. 2012; Bertaux et al. 2012) point to significant disagreement, which in some cases have been related to heterogeneous (gas-dust) chemistry beyond the classical gas-gas homogeneous reactions.We address these concerns by acquiring full 2D maps of water and ozone (via O2 dayglow) on Mars, employing high spectral infrared spectrometers at ground-based telescopes (CRIRES/VLT and CSHELL/NASA-IRTF). By performing a rotational analysis on the O2 lines, we derive molecular temperature maps that we use to derive the vertical level of the emission (e.g., Novak et al. 2002). Our maps sample the full observable disk of Mars on March/25/2008 (Ls=50°, northern winter) and on Jan/29/2014 (Ls=83°, northern spring). The maps reveal a strong dependence of the O2 emission and water burden on local orography, while the temperature maps are in strong disagreement with current models. Could this be the signature of heterogeneous chemistry? We will present the global maps and will discuss possible scenarios to explain the observations.This work was partially funded by grants from NASA's Planetary Astronomy Program (344-32-51-96), NASA’s Mars Fundamental Research Program (203959.02.02.20.29), NASA’s Astrobiology Program (344-53-51), and the NSF-RUI Program (AST-805540). We thank the administration and staff of the European Southern Observatory/VLT and NASA-IRTF for awarding observing time and coordinating our observations.Bertaux, J.-L., Gondet, B., Lefèvre, F., et al. 2012. J. Geophys. Res. Pl. 117. pp. 1-9.Clancy, R.T., Sandor, B.J., Wolff, M.J., et al. 2012. J. Geophys. Res

  8. Multi-scale salient feature extraction on mesh models

    Yang, Yongliang; Shen, ChaoHui

    2012-01-01

    We present a new method of extracting multi-scale salient features on meshes. It is based on robust estimation of curvature on multiple scales. The coincidence between salient feature and the scale of interest can be established straightforwardly, where detailed feature appears on small scale and feature with more global shape information shows up on large scale. We demonstrate this multi-scale description of features accords with human perception and can be further used for several applications as feature classification and viewpoint selection. Experiments exhibit that our method as a multi-scale analysis tool is very helpful for studying 3D shapes. © 2012 Springer-Verlag.

  9. The stratigraphy of Mars

    Tanaka, Kenneth L.

    1986-01-01

    A global stratigraphy of Mars was developed from a global geologic map series derived from Viking images; the stratigraphy is composed of three maps. A new chronostratigraphic classification system which consists of lower, middle, and upper Noachian, Hesperian, and Amazonian systems is described. The crater-density boundaries of the chronostratigraphic units and the absolute ages of the Martian epochs aer estimated. The relative ages of major geologic units and featues are calculated and analyzed. The geologic history of Mars is summarized on the maps in terms of epochs.

  10. Multiscale Cancer Modeling

    Macklin, Paul; Cristini, Vittorio

    2013-01-01

    Simulating cancer behavior across multiple biological scales in space and time, i.e., multiscale cancer modeling, is increasingly being recognized as a powerful tool to refine hypotheses, focus experiments, and enable more accurate predictions. A growing number of examples illustrate the value of this approach in providing quantitative insight on the initiation, progression, and treatment of cancer. In this review, we introduce the most recent and important multiscale cancer modeling works that have successfully established a mechanistic link between different biological scales. Biophysical, biochemical, and biomechanical factors are considered in these models. We also discuss innovative, cutting-edge modeling methods that are moving predictive multiscale cancer modeling toward clinical application. Furthermore, because the development of multiscale cancer models requires a new level of collaboration among scientists from a variety of fields such as biology, medicine, physics, mathematics, engineering, and computer science, an innovative Web-based infrastructure is needed to support this growing community. PMID:21529163

  11. Multiscale Representations Phase II

    Bar-Yam, Yaneer

    2004-01-01

    .... Multiscale analysis provides an analytic tool that can be applied to evaluating force capabilities as well as the relevance of designs for technological innovations to support force structures and their modernization...

  12. Multiscale System Theory

    1990-02-21

    LIDS-P-1953 Multiscale System Theory Albert Benveniste IRISA-INRIA, Campus de Beaulieu 35042 RENNES CEDEX, FRANCE Ramine Nikoukhah INRIA...TITLE AND SUBTITLE Multiscale System Theory 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e...the development of a corresponding system theory and a theory of stochastic processes and their estimation. The research presented in this and several

  13. Multiscale Simulations Using Particles

    Walther, Jens Honore

    vortex methods for problems in continuum fluid dynamics, dissipative particle dynamics for flow at the meso scale, and atomistic molecular dynamics simulations of nanofluidic systems. We employ multiscale techniques to breach the atomistic and continuum scales to study fundamental problems in fluid...... dynamics. Recent work on the thermophoretic motion of water nanodroplets confined inside carbon nanotubes, and multiscale techniques for polar liquids will be discussed in detail at the symposium....

  14. The cascade from local to global dust storms on Mars: Temporal and spatial thresholds on thermal and dynamical feedback

    Toigo, Anthony D.; Richardson, Mark I.; Wang, Huiqun; Guzewich, Scott D.; Newman, Claire E.

    2018-03-01

    We use the MarsWRF general circulation model to examine the temporal and spatial response of the atmosphere to idealized local and regional dust storm radiative heating. The ability of storms to modify the atmosphere away from the location of dust heating is a likely prerequisite for dynamical feedbacks that aid the growth of storms beyond the local scale, while the ability of storms to modify the atmosphere after the cessation of dust radiative heating is potentially important in preconditioning the atmosphere prior to large scale storms. Experiments were conducted over a range of static, prescribed storm sizes, durations, optical depth strengths, locations, and vertical extents of dust heating. Our results show that for typical sizes (order 105 km2) and durations (1-10 sols) of local dust storms, modification of the atmosphere is less than the typical variability of the unperturbed (storm-free) state. Even if imposed on regional storm length scales (order 106 km2), a 1-sol duration storm similarly does not significantly modify the background atmosphere. Only when imposed for 10 sols does a regional dust storm create a significant impact on the background atmosphere, allowing for the possibility of self-induced dynamical storm growth. These results suggest a prototype for how the subjective observational categorization of storms may be related to objective dynamical growth feedbacks that only become available to storms after they achieve a threshold size and duration, or if they grow into an atmosphere preconditioned by a prior large and sustained storm.

  15. Mars Navigator: An Interactive Multimedia Program about Mars, Aerospace Engineering, Astronomy, and the JPL Mars Missions. [CD-ROM

    Gramoll, Kurt

    This CD-ROM introduces basic astronomy and aerospace engineering by examining the Jet Propulsion Laboratory's (JPL) Mars Pathfinder and Mars Global Surveyor missions to Mars. It contains numerous animations and narrations in addition to detailed graphics and text. Six interactive laboratories are included to help understand topics such as the…

  16. Correlations Between Olivine Abundance and Thermal Inertia: Implications for Global Weathering and/or Alteration on Mars

    Hamilton, V. E.; McDowell, M. L.; Koeppen, W. C.

    2010-03-01

    TES data show no global trend between thermal inertia and olivine abundance. But it is premature to conclude that all dark surfaces were once more mafic OR that olivine is not preferentially removed from olivine-enriched outcrops as they erode.

  17. Multiscale Computing with the Multiscale Modeling Library and Runtime Environment

    Borgdorff, J.; Mamonski, M.; Bosak, B.; Groen, D.; Ben Belgacem, M.; Kurowski, K.; Hoekstra, A.G.

    2013-01-01

    We introduce a software tool to simulate multiscale models: the Multiscale Coupling Library and Environment 2 (MUSCLE 2). MUSCLE 2 is a component-based modeling tool inspired by the multiscale modeling and simulation framework, with an easy-to-use API which supports Java, C++, C, and Fortran. We

  18. Mars bevares

    Hendricks, Vincent Fella; Hendricks, Elbert

    2009-01-01

    2009 er femåret for Mission Mars. I den anledning opridser de to kronikører, far og søn, hvorfor man bør lade planer om en bemandet tur til Mars forblive i skrivebordsskuffen......2009 er femåret for Mission Mars. I den anledning opridser de to kronikører, far og søn, hvorfor man bør lade planer om en bemandet tur til Mars forblive i skrivebordsskuffen...

  19. Multiscale modelling of DNA mechanics

    Dršata, Tomáš; Lankaš, Filip

    2015-01-01

    Mechanical properties of DNA are important not only in a wide range of biological processes but also in the emerging field of DNA nanotechnology. We review some of the recent developments in modeling these properties, emphasizing the multiscale nature of the problem. Modern atomic resolution, explicit solvent molecular dynamics simulations have contributed to our understanding of DNA fine structure and conformational polymorphism. These simulations may serve as data sources to parameterize rigid base models which themselves have undergone major development. A consistent buildup of larger entities involving multiple rigid bases enables us to describe DNA at more global scales. Free energy methods to impose large strains on DNA, as well as bead models and other approaches, are also briefly discussed. (topical review)

  20. Effect of global cardiac ischemia on human ventricular fibrillation: insights from a multi-scale mechanistic model of the human heart.

    Ivan V Kazbanov

    2014-11-01

    Full Text Available Acute regional ischemia in the heart can lead to cardiac arrhythmias such as ventricular fibrillation (VF, which in turn compromise cardiac output and result in secondary global cardiac ischemia. The secondary ischemia may influence the underlying arrhythmia mechanism. A recent clinical study documents the effect of global cardiac ischaemia on the mechanisms of VF. During 150 seconds of global ischemia the dominant frequency of activation decreased, while after reperfusion it increased rapidly. At the same time the complexity of epicardial excitation, measured as the number of epicardical phase singularity points, remained approximately constant during ischemia. Here we perform numerical studies based on these clinical data and propose explanations for the observed dynamics of the period and complexity of activation patterns. In particular, we study the effects on ischemia in pseudo-1D and 2D cardiac tissue models as well as in an anatomically accurate model of human heart ventricles. We demonstrate that the fall of dominant frequency in VF during secondary ischemia can be explained by an increase in extracellular potassium, while the increase during reperfusion is consistent with washout of potassium and continued activation of the ATP-dependent potassium channels. We also suggest that memory effects are responsible for the observed complexity dynamics. In addition, we present unpublished clinical results of individual patient recordings and propose a way of estimating extracellular potassium and activation of ATP-dependent potassium channels from these measurements.

  1. Multiscale Biological Materials

    Frølich, Simon

    of multiscale biological systems have been investigated and new research methods for automated Rietveld refinement and diffraction scattering computed tomography developed. The composite nature of biological materials was investigated at the atomic scale by looking at the consequences of interactions between...

  2. Spiders from Mars?

    2003-01-01

    MGS MOC Release No. MOC2-426, 19 July 2003No, this is not a picture of a giant, martian spider web. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a plethora of polygonal features on the floor of a northern hemisphere impact crater near 65.6oN, 327.7oW. The picture was acquired during spring, after the seasonal carbon dioxide frost cap had largely migrated through the region. At the time the picture was taken, remnants of seasonal frost remained on the crater rim and on the edges of the troughs that bound each of the polygons. Frost often provides a helpful hint as to where polygons and patterned ground occur. The polygons, if they were on Earth, would indicate the presence of freeze-thaw cycles in ground ice. Although uncertain, the same might be true of Mars. Sunlight illuminates the scene from the lower left.

  3. Towards distributed multiscale computing for the VPH

    Hoekstra, A.G.; Coveney, P.

    2010-01-01

    Multiscale modeling is fundamental to the Virtual Physiological Human (VPH) initiative. Most detailed three-dimensional multiscale models lead to prohibitive computational demands. As a possible solution we present MAPPER, a computational science infrastructure for Distributed Multiscale Computing

  4. Mars Pathfinder

    Murdin, P.

    2000-11-01

    First of NASA's Discovery missions. Launched in December 1996 and arrived at Mars on 4 July 1997. Mainly intended as a technology demonstration mission. Used airbags to cushion the landing on Mars. The Carl Sagan Memorial station returned images of an ancient flood plain in Ares Vallis. The 10 kg Sojourner rover used an x-ray spectrometer to study the composition of rocks and travelled about 100 ...

  5. Exploring Mars

    Breuil, Stéphanie

    2016-04-01

    Mars is our neighbour planet and has always fascinated humans as it has been seen as a potential abode for life. Knowledge about Mars is huge and was constructed step by step through numerous missions. It could be difficult to describe these missions, the associated technology, the results, the questions they raise, that's why an activity is proposed, that directly interests students. Their production is presented in the poster. Step 1: The main Mars feature and the first Mars explorations using telescope are presented to students. It should be really interesting to present "Mars Canals" from Percival Lowell as it should also warn students against flawed interpretation. Moreover, this study has raised the big question about extra-terrestrial life on Mars for the first time. Using Google Mars is then a good way to show the huge knowledge we have on the planet and to introduce modern missions. Step 2: Students have to choose and describe one of the Mars mission from ESA and NASA. They should work in pairs. Web sites from ESA and NASA are available and the teacher makes sure the main missions will be studied. Step 3: Students have to collect different pieces of information about the mission - When? Which technology? What were the main results? What type of questions does it raise? They prepare an oral presentation in the form they want (role play, academic presentation, using a poster, PowerPoint). They also have to produce playing cards about the mission that could be put on a timeline. Step 4: As a conclusion, the different cards concerning different missions are mixed. Groups of students receive cards and they have to put them on a timeline as fast as possible. It is also possible to play the game "timeline".

  6. Globalization

    Tulio Rosembuj

    2006-12-01

    Full Text Available There is no singular globalization, nor is the result of an individual agent. We could start by saying that global action has different angles and subjects who perform it are different, as well as its objectives. The global is an invisible invasion of materials and immediate effects.

  7. Globalization

    Tulio Rosembuj

    2006-01-01

    There is no singular globalization, nor is the result of an individual agent. We could start by saying that global action has different angles and subjects who perform it are different, as well as its objectives. The global is an invisible invasion of materials and immediate effects.

  8. Multiscale Finite Element Methods for Flows on Rough Surfaces

    Efendiev, Yalchin

    2013-01-01

    In this paper, we present the Multiscale Finite Element Method (MsFEM) for problems on rough heterogeneous surfaces. We consider the diffusion equation on oscillatory surfaces. Our objective is to represent small-scale features of the solution via multiscale basis functions described on a coarse grid. This problem arises in many applications where processes occur on surfaces or thin layers. We present a unified multiscale finite element framework that entails the use of transformations that map the reference surface to the deformed surface. The main ingredients of MsFEM are (1) the construction of multiscale basis functions and (2) a global coupling of these basis functions. For the construction of multiscale basis functions, our approach uses the transformation of the reference surface to a deformed surface. On the deformed surface, multiscale basis functions are defined where reduced (1D) problems are solved along the edges of coarse-grid blocks to calculate nodalmultiscale basis functions. Furthermore, these basis functions are transformed back to the reference configuration. We discuss the use of appropriate transformation operators that improve the accuracy of the method. The method has an optimal convergence if the transformed surface is smooth and the image of the coarse partition in the reference configuration forms a quasiuniform partition. In this paper, we consider such transformations based on harmonic coordinates (following H. Owhadi and L. Zhang [Comm. Pure and Applied Math., LX(2007), pp. 675-723]) and discuss gridding issues in the reference configuration. Numerical results are presented where we compare the MsFEM when two types of deformations are used formultiscale basis construction. The first deformation employs local information and the second deformation employs a global information. Our numerical results showthat one can improve the accuracy of the simulations when a global information is used. © 2013 Global-Science Press.

  9. Magnetic storms on Mars

    Vennerstrøm, Susanne

    2011-01-01

    and typical time profile of such periods is investigated and compared to solar wind measurements at Earth. Typical durations of the events are 20–40h, and there is a tendency for large events to last longer, but a large spread in duration and intensity are found. The large and medium intensity events at Mars......Based on data from the Mars Global Surveyor magnetometer we examine periods of significantly enhanced magnetic disturbances in the martian space environment. Using almost seven years of observations during the maximum and early declining phase of the previous solar cycle the occurrence pattern...... are found to occur predominantly in association with interplanetary sector boundaries, with solar wind dynamic pressure enhancements being the most likely interplanetary driver. In addition it is found that, on time scales of months to several years, the dominant cause of global variability of the magnetic...

  10. Multiscale singularity trees

    Somchaipeng, Kerawit; Sporring, Jon; Johansen, Peter

    2007-01-01

    We propose MultiScale Singularity Trees (MSSTs) as a structure to represent images, and we propose an algorithm for image comparison based on comparing MSSTs. The algorithm is tested on 3 public image databases and compared to 2 state-of-theart methods. We conclude that the computational complexity...... of our algorithm only allows for the comparison of small trees, and that the results of our method are comparable with state-of-the-art using much fewer parameters for image representation....

  11. Multiscale modelling of nanostructures

    Vvedensky, Dimitri D

    2004-01-01

    Most materials phenomena are manifestations of processes that are operative over a vast range of length and time scales. A complete understanding of the behaviour of materials thereby requires theoretical and computational tools that span the atomic-scale detail of first-principles methods and the more coarse-grained description provided by continuum equations. Recent efforts have focused on combining traditional methodologies-density functional theory, molecular dynamics, Monte Carlo methods and continuum descriptions-within a unified multiscale framework. This review covers the techniques that have been developed to model various aspects of materials behaviour with the ultimate aim of systematically coupling the atomistic to the continuum descriptions. The approaches described typically have been motivated by particular applications but can often be applied in wider contexts. The self-assembly of quantum dot ensembles will be used as a case study for the issues that arise and the methods used for all nanostructures. Although quantum dots can be obtained with all the standard growth methods and for a variety of material systems, their appearance is a quite selective process, involving the competition between equilibrium and kinetic effects, and the interplay between atomistic and long-range interactions. Most theoretical models have addressed particular aspects of the ordering kinetics of quantum dot ensembles, with far fewer attempts at a comprehensive synthesis of this inherently multiscale phenomenon. We conclude with an assessment of the current status of multiscale modelling strategies and highlight the main outstanding issues. (topical review)

  12. Multivariate multiscale entropy of financial markets

    Lu, Yunfan; Wang, Jun

    2017-11-01

    In current process of quantifying the dynamical properties of the complex phenomena in financial market system, the multivariate financial time series are widely concerned. In this work, considering the shortcomings and limitations of univariate multiscale entropy in analyzing the multivariate time series, the multivariate multiscale sample entropy (MMSE), which can evaluate the complexity in multiple data channels over different timescales, is applied to quantify the complexity of financial markets. Its effectiveness and advantages have been detected with numerical simulations with two well-known synthetic noise signals. For the first time, the complexity of four generated trivariate return series for each stock trading hour in China stock markets is quantified thanks to the interdisciplinary application of this method. We find that the complexity of trivariate return series in each hour show a significant decreasing trend with the stock trading time progressing. Further, the shuffled multivariate return series and the absolute multivariate return series are also analyzed. As another new attempt, quantifying the complexity of global stock markets (Asia, Europe and America) is carried out by analyzing the multivariate returns from them. Finally we utilize the multivariate multiscale entropy to assess the relative complexity of normalized multivariate return volatility series with different degrees.

  13. Globalization

    Andru?cã Maria Carmen

    2013-01-01

    The field of globalization has highlighted an interdependence implied by a more harmonious understanding determined by the daily interaction between nations through the inducement of peace and the management of streamlining and the effectiveness of the global economy. For the functioning of the globalization, the developing countries that can be helped by the developed ones must be involved. The international community can contribute to the institution of the development environment of the gl...

  14. Mars Thermal Inertia

    2001-01-01

    This image shows the global thermal inertia of the Martian surface as measured by the Thermal Emission Spectrometer (TES) instrument on the Mars Global Surveyor. The data were acquired during the first 5000 orbits of the MGS mapping mission. The pattern of inertia variations observed by TES agrees well with the thermal inertia maps made by the Viking Infrared Thermal Mapper experiment, but the TES data shown here are at significantly higher spatial resolution (15 km versus 60 km).The TES instrument was built by Santa Barbara Remote Sensing and is operated by Philip R. Christensen, of Arizona State University, Tempe, AZ.

  15. Magnetic Storms at Mars and Earth

    Vennerstrøm, Susanne; Falkenberg, Thea Vilstrup

    In analogy with magnetic storms at the Earth, periods of significantly enhanced global magnetic activity also exist at Mars. The extensive database of magnetic measurements from Mars Global Surveyor (MGS), covering almost an entire solar cycle, is used in combination with geomagnetic activity...... indices at Earth to compare the occurrence of magnetic storms at Mars and Earth. Based on superposed epochs analysis the time-development of typical magnetic storms at Mars and Earth is described. In contradiction to storms at Earth, most magnetic storms at Mars are found to be associated...... with heliospheric current sheet crossings, where the IMF changes polarity. While most storms at the Earth occur due to significant southward excursions of the IMF associated with CMEs, at Mars most storms seem to be associated with the density enhancement of the heliospheric current sheet. Density enhancements...

  16. Multiscale Signal Analysis and Modeling

    Zayed, Ahmed

    2013-01-01

    Multiscale Signal Analysis and Modeling presents recent advances in multiscale analysis and modeling using wavelets and other systems. This book also presents applications in digital signal processing using sampling theory and techniques from various function spaces, filter design, feature extraction and classification, signal and image representation/transmission, coding, nonparametric statistical signal processing, and statistical learning theory. This book also: Discusses recently developed signal modeling techniques, such as the multiscale method for complex time series modeling, multiscale positive density estimations, Bayesian Shrinkage Strategies, and algorithms for data adaptive statistics Introduces new sampling algorithms for multidimensional signal processing Provides comprehensive coverage of wavelets with presentations on waveform design and modeling, wavelet analysis of ECG signals and wavelet filters Reviews features extraction and classification algorithms for multiscale signal and image proce...

  17. Multiscale computing in the exascale era

    Alowayyed, S.; Groen, D.; Coveney, P.V.; Hoekstra, A.G.

    We expect that multiscale simulations will be one of the main high performance computing workloads in the exascale era. We propose multiscale computing patterns as a generic vehicle to realise load balanced, fault tolerant and energy aware high performance multiscale computing. Multiscale computing

  18. Solar radiation on Mars: Update 1991

    Appelbaum, Joseph; Landis, Geoffrey A.

    1991-01-01

    Detailed information on solar radiation characteristics on Mars are necessary for effective design of future planned solar energy systems operating on the surface of Mars. A procedure and solar radiation related data are presented from which the daily variation of the global, direct beam and diffuse insolation on Mars are calculated. Given the optical depth of the Mars atmosphere, the global radiation is calculated from the normalized net flux function based on multiple wavelength and multiple scattering of the solar radiation. The direct beam was derived from the optical depth using Beer's law, and the diffuse component was obtained from the difference of the global and the direct beam radiation. The optical depths of the Mars atmosphere were derived from images taken of the Sun with a special diode on the cameras used on the two Viking Landers.

  19. 2D deblending using the multi-scale shaping scheme

    Li, Qun; Ban, Xingan; Gong, Renbin; Li, Jinnuo; Ge, Qiang; Zu, Shaohuan

    2018-01-01

    Deblending can be posed as an inversion problem, which is ill-posed and requires constraint to obtain unique and stable solution. In blended record, signal is coherent, whereas interference is incoherent in some domains (e.g., common receiver domain and common offset domain). Due to the different sparsity, coefficients of signal and interference locate in different curvelet scale domains and have different amplitudes. Take into account the two differences, we propose a 2D multi-scale shaping scheme to constrain the sparsity to separate the blended record. In the domain where signal concentrates, the multi-scale scheme passes all the coefficients representing signal, while, in the domain where interference focuses, the multi-scale scheme suppresses the coefficients representing interference. Because the interference is suppressed evidently at each iteration, the constraint of multi-scale shaping operator in all scale domains are weak to guarantee the convergence of algorithm. We evaluate the performance of the multi-scale shaping scheme and the traditional global shaping scheme by using two synthetic and one field data examples.

  20. Conformal-Based Surface Morphing and Multi-Scale Representation

    Ka Chun Lam

    2014-05-01

    Full Text Available This paper presents two algorithms, based on conformal geometry, for the multi-scale representations of geometric shapes and surface morphing. A multi-scale surface representation aims to describe a 3D shape at different levels of geometric detail, which allows analyzing or editing surfaces at the global or local scales effectively. Surface morphing refers to the process of interpolating between two geometric shapes, which has been widely applied to estimate or analyze deformations in computer graphics, computer vision and medical imaging. In this work, we propose two geometric models for surface morphing and multi-scale representation for 3D surfaces. The basic idea is to represent a 3D surface by its mean curvature function, H, and conformal factor function λ, which uniquely determine the geometry of the surface according to Riemann surface theory. Once we have the (λ, H parameterization of the surface, post-processing of the surface can be done directly on the conformal parameter domain. In particular, the problem of multi-scale representations of shapes can be reduced to the signal filtering on the λ and H parameters. On the other hand, the surface morphing problem can be transformed to an interpolation process of two sets of (λ, H parameters. We test the proposed algorithms on 3D human face data and MRI-derived brain surfaces. Experimental results show that our proposed methods can effectively obtain multi-scale surface representations and give natural surface morphing results.

  1. Microphysics in Multi-scale Modeling System with Unified Physics

    Tao, Wei-Kuo

    2012-01-01

    Recently, a multi-scale modeling system with unified physics was developed at NASA Goddard. It consists of (1) a cloud-resolving model (Goddard Cumulus Ensemble model, GCE model), (2) a regional scale model (a NASA unified weather research and forecast, WRF), (3) a coupled CRM and global model (Goddard Multi-scale Modeling Framework, MMF), and (4) a land modeling system. The same microphysical processes, long and short wave radiative transfer and land processes and the explicit cloud-radiation, and cloud-land surface interactive processes are applied in this multi-scale modeling system. This modeling system has been coupled with a multi-satellite simulator to use NASA high-resolution satellite data to identify the strengths and weaknesses of cloud and precipitation processes simulated by the model. In this talk, a review of developments and applications of the multi-scale modeling system will be presented. In particular, the microphysics development and its performance for the multi-scale modeling system will be presented.

  2. Generalized multiscale finite element methods (GMsFEM)

    Efendiev, Yalchin R.; Galvis, Juan; Hou, Thomasyizhao

    2013-01-01

    In this paper, we propose a general approach called Generalized Multiscale Finite Element Method (GMsFEM) for performing multiscale simulations for problems without scale separation over a complex input space. As in multiscale finite element methods (MsFEMs), the main idea of the proposed approach is to construct a small dimensional local solution space that can be used to generate an efficient and accurate approximation to the multiscale solution with a potentially high dimensional input parameter space. In the proposed approach, we present a general procedure to construct the offline space that is used for a systematic enrichment of the coarse solution space in the online stage. The enrichment in the online stage is performed based on a spectral decomposition of the offline space. In the online stage, for any input parameter, a multiscale space is constructed to solve the global problem on a coarse grid. The online space is constructed via a spectral decomposition of the offline space and by choosing the eigenvectors corresponding to the largest eigenvalues. The computational saving is due to the fact that the construction of the online multiscale space for any input parameter is fast and this space can be re-used for solving the forward problem with any forcing and boundary condition. Compared with the other approaches where global snapshots are used, the local approach that we present in this paper allows us to eliminate unnecessary degrees of freedom on a coarse-grid level. We present various examples in the paper and some numerical results to demonstrate the effectiveness of our method. © 2013 Elsevier Inc.

  3. Generalized multiscale finite element methods (GMsFEM)

    Efendiev, Yalchin R.

    2013-10-01

    In this paper, we propose a general approach called Generalized Multiscale Finite Element Method (GMsFEM) for performing multiscale simulations for problems without scale separation over a complex input space. As in multiscale finite element methods (MsFEMs), the main idea of the proposed approach is to construct a small dimensional local solution space that can be used to generate an efficient and accurate approximation to the multiscale solution with a potentially high dimensional input parameter space. In the proposed approach, we present a general procedure to construct the offline space that is used for a systematic enrichment of the coarse solution space in the online stage. The enrichment in the online stage is performed based on a spectral decomposition of the offline space. In the online stage, for any input parameter, a multiscale space is constructed to solve the global problem on a coarse grid. The online space is constructed via a spectral decomposition of the offline space and by choosing the eigenvectors corresponding to the largest eigenvalues. The computational saving is due to the fact that the construction of the online multiscale space for any input parameter is fast and this space can be re-used for solving the forward problem with any forcing and boundary condition. Compared with the other approaches where global snapshots are used, the local approach that we present in this paper allows us to eliminate unnecessary degrees of freedom on a coarse-grid level. We present various examples in the paper and some numerical results to demonstrate the effectiveness of our method. © 2013 Elsevier Inc.

  4. Artificial structures on Mars

    Van Flandern, T.

    2002-05-01

    Approximately 70,000 images of the surface of Mars at a resolution of up to 1.4 meters per pixel, taken by the Mars Global Surveyor spacecraft, are now in public archives. Approximately 1% of those images show features that can be broadly described as `special shapes', `tracks, trails, and possible vegetation', `spots, stripes, and tubes', `artistic imagery', and `patterns and symbols'. Rather than optical illusions and tricks of light and shadow, most of these have the character that, if photographed on Earth, no one would doubt that they were the products of large biology and intelligence. In a few cases, relationships, context, and fulfillment of a priori predictions provide objective evidence of artificiality that is exempt from the influence of experimenter biases. Only controlled test results can be trusted because biases are strong and operate both for and against artificiality.

  5. Multiscale principal component analysis

    Akinduko, A A; Gorban, A N

    2014-01-01

    Principal component analysis (PCA) is an important tool in exploring data. The conventional approach to PCA leads to a solution which favours the structures with large variances. This is sensitive to outliers and could obfuscate interesting underlying structures. One of the equivalent definitions of PCA is that it seeks the subspaces that maximize the sum of squared pairwise distances between data projections. This definition opens up more flexibility in the analysis of principal components which is useful in enhancing PCA. In this paper we introduce scales into PCA by maximizing only the sum of pairwise distances between projections for pairs of datapoints with distances within a chosen interval of values [l,u]. The resulting principal component decompositions in Multiscale PCA depend on point (l,u) on the plane and for each point we define projectors onto principal components. Cluster analysis of these projectors reveals the structures in the data at various scales. Each structure is described by the eigenvectors at the medoid point of the cluster which represent the structure. We also use the distortion of projections as a criterion for choosing an appropriate scale especially for data with outliers. This method was tested on both artificial distribution of data and real data. For data with multiscale structures, the method was able to reveal the different structures of the data and also to reduce the effect of outliers in the principal component analysis

  6. Globalization

    Plum, Maja

    Globalization is often referred to as external to education - a state of affair facing the modern curriculum with numerous challenges. In this paper it is examined as internal to curriculum; analysed as a problematization in a Foucaultian sense. That is, as a complex of attentions, worries, ways...... of reasoning, producing curricular variables. The analysis is made through an example of early childhood curriculum in Danish Pre-school, and the way the curricular variable of the pre-school child comes into being through globalization as a problematization, carried forth by the comparative practices of PISA...

  7. Globalization

    F. Gerard Adams

    2008-01-01

    The rapid globalization of the world economy is causing fundamental changes in patterns of trade and finance. Some economists have argued that globalization has arrived and that the world is “flat†. While the geographic scope of markets has increased, the author argues that new patterns of trade and finance are a result of the discrepancies between “old†countries and “new†. As the differences are gradually wiped out, particularly if knowledge and technology spread worldwide, the t...

  8. Mars: Atmosphere

    Moroz, V.; Murdin, P.

    2001-07-01

    The atmosphere of MARS is much thinner than the terrestrial one. However, even the simplest visual telescopic observations show a set of atmospheric events such as seasonal exchange of material between polar caps, temporal appearance of clouds and changes of visibility of dark regions on the disk of the planet. In 1947 the prominent CO2 bands in the near-infrared part of the Martian spectrum were...

  9. A Multiscale, Nonlinear, Modeling Framework Enabling the Design and Analysis of Composite Materials and Structures

    Bednarcyk, Brett A.; Arnold, Steven M.

    2012-01-01

    A framework for the multiscale design and analysis of composite materials and structures is presented. The ImMAC software suite, developed at NASA Glenn Research Center, embeds efficient, nonlinear micromechanics capabilities within higher scale structural analysis methods such as finite element analysis. The result is an integrated, multiscale tool that relates global loading to the constituent scale, captures nonlinearities at this scale, and homogenizes local nonlinearities to predict their effects at the structural scale. Example applications of the multiscale framework are presented for the stochastic progressive failure of a SiC/Ti composite tensile specimen and the effects of microstructural variations on the nonlinear response of woven polymer matrix composites.

  10. Effects of a CME on Mars

    Falkenberg, Thea Vilstrup; Vennerstrøm, Susanne; Brain, D.

    this balances the solar wind pressure. As the dynamic pressure is severely increased during a CME, so is the magnetic pressure. A CME are also typically connected to a Solar Energetic Particle (SEP) event, causing large amounts of radiation. When the shock front of a CME arrives at Mars strong signals are seen......We investigate the effects of a Coronal Mass Ejection (CME) on Mars. The magnetic field in the magnetic pileup region on Mars is dominated by the dynamic pressure from the solar as increased dynamic pressure compresses the magnetic pileup region causing a larger magnetic pressure, until...... in both the magnetic field data and in the radiation data. Based on Mars Global Surveyor (MGS) Magnetometer (MAG) and Electron Reflectometer (ER) data we study the radiation and magnetic field variations on Mars during a CME event. We also compare the effects on Mars to the effects on Earth for the same...

  11. Mars Analog Rio Tinto Experiment (MARTE): An Experimental Demonstration of Key Technologies for Searching for Life on Mars

    Stoker, Carol

    2004-01-01

    The discovery of near surface ground ice by the Mars Odyssey mission and the abundant evidence for recent Gulley features observed by the Mars Global Surveyor mission support longstanding theoretical arguments for subsurface liquid water on Mars. Thus, implementing the Mars program goal to search for life points to drilling on Mars to reach liquid water, collecting samples and analyzing them with instrumentation to detect in situ organisms and biomarker compounds. Searching for life in the subsurface of Mars will require drilling, sample extraction and handling, and new technologies to find and identify biomarker compounds and search for living organisms.

  12. Multi-scales analysis of the global change impact on the diversity of the aphid communities; Analyse multi-echelle de l'impact du changement global sur la diversite des communautes aphidiennes

    Hulle, M

    2007-07-01

    The primary objective of this project is to investigate the effects of global change on the biodiversity of aphid communities in Western Europe. Biodiversity has been examined at 3 levels: total number of species, phenology and reproductive strategy. Data were provided by EXAMINE, the European suction traps network which has been now operating for 35 years. 392 different species have been identified. At each location, total number of species has been regularly increasing, one additional species being caught every 1 or 2 years depending on location. This is due to introduced species but also to warming which favours rare species. No general trend of increasing density has been detected, but phenological earliness of almost all species (annual date of first appearance in suction traps) is strongly correlated with temperature and especially with mean daily temperature (during more or less long periods of time lying principally in February and March) or number of days below 0 C. Strong relationships between aphid phenology and environmental variables have been found and there is strong discrimination between species with different life cycle strategies, and between species feeding on herbs and trees, suggesting the possible value of trait-based groupings in predicting responses to environmental changes. These preliminary results suggest that 1) biodiversity has increased during the last decades; 2) there is a pool of species among which some of them reach a detectable density only during years where temperatures are high enough; 3) a set of newly introduced species succeed in settling being favoured by warming and 4) phenology of aphids is expected to advance and their abundance to increase with temperature, and the possible role of natural enemies to regulate abundant species is discussed. (author)

  13. Mars geodesy, rotation and gravity

    Rosenblatt, Pascal; Dehant, Veronique

    2010-01-01

    This review provides explanations of how geodesy, rotation and gravity can be addressed using radioscience data of an orbiter around a planet or of the lander on its surface. The planet Mars is the center of the discussion. The information one can get from orbitography and radioscience in general concerns the global static gravitational field, the time variation of the gravitational field induced by mass exchange between the atmosphere and the ice caps, the time variation of the gravitational field induced by the tides, the secular changes in the spacecraft's orbit induced by the little moons of Mars named Phobos and Deimos, the gravity induced by particular targets, the Martian ephemerides, and Mars' rotation and orientation. The paper addresses as well the determination of the geophysical parameters of Mars and, in particular, the state of Mars' core and its size, which is important for understanding the planet's evolution. Indeed, the state and dimension of the core determined from the moment of inertia and nutation depend in turn on the percentage of light elements in the core as well as on the core temperature, which is related to heat transport in the mantle. For example, the radius of the core has implications for possible mantle convection scenarios and, in particular, for the presence of a perovskite phase transition at the bottom of the mantle. This is also important for our understanding of the large volcanic province Tharsis on the surface of Mars. (invited reviews)

  14. Mars @ ASDC

    Carraro, Francesco

    "Mars @ ASDC" is a project born with the goal of using the new web technologies to assist researches involved in the study of Mars. This project employs Mars map and javascript APIs provided by Google to visualize data acquired by space missions on the planet. So far, visualization of tracks acquired by MARSIS and regions observed by VIRTIS-Rosetta has been implemented. The main reason for the creation of this kind of tool is the difficulty in handling hundreds or thousands of acquisitions, like the ones from MARSIS, and the consequent difficulty in finding observations related to a particular region. This led to the development of a tool which allows to search for acquisitions either by defining the region of interest through a set of geometrical parameters or by manually selecting the region on the map through a few mouse clicks The system allows the visualization of tracks (acquired by MARSIS) or regions (acquired by VIRTIS-Rosetta) which intersect the user defined region. MARSIS tracks can be visualized both in Mercator and polar projections while the regions observed by VIRTIS can presently be visualized only in Mercator projection. The Mercator projection is the standard map provided by Google. The polar projections are provided by NASA and have been developed to be used in combination with APIs provided by Google The whole project has been developed following the "open source" philosophy: the client-side code which handles the functioning of the web page is written in javascript; the server-side code which executes the searches for tracks or regions is written in PHP and the DB which undergoes the system is MySQL.

  15. NASA Mars Conference

    Reiber, D.B.

    1988-01-01

    Papers about Mars and Mars exploration are presented, covering topics such as Martian history, geology, volcanism, channels, moons, atmosphere, meteorology, water on the planet, and the possibility of life. The unmanned exploration of Mars is discussed, including the Phobos Mission, the Mars Observer, the Mars Aeronomy Observer, the seismic network, Mars sample return missions, and the Mars Ball, an inflatable-sectored-tire rover concept. Issues dealing with manned exploration of Mars are examined, such as the reasons for exploring Mars, mission scenarios, a transportation system for routine visits, technologies for Mars expeditions, the human factors for Mars missions, life support systems, living and working on Mars, and the report of the National Commission on Space

  16. Multi-scale symbolic transfer entropy analysis of EEG

    Yao, Wenpo; Wang, Jun

    2017-10-01

    From both global and local perspectives, we symbolize two kinds of EEG and analyze their dynamic and asymmetrical information using multi-scale transfer entropy. Multi-scale process with scale factor from 1 to 199 and step size of 2 is applied to EEG of healthy people and epileptic patients, and then the permutation with embedding dimension of 3 and global approach are used to symbolize the sequences. The forward and reverse symbol sequences are taken as the inputs of transfer entropy. Scale factor intervals of permutation and global way are (37, 57) and (65, 85) where the two kinds of EEG have satisfied entropy distinctions. When scale factor is 67, transfer entropy of the healthy and epileptic subjects of permutation, 0.1137 and 0.1028, have biggest difference. And the corresponding values of the global symbolization is 0.0641 and 0.0601 which lies in the scale factor of 165. Research results show that permutation which takes contribution of local information has better distinction and is more effectively applied to our multi-scale transfer entropy analysis of EEG.

  17. An Orbit Propagation Software for Mars Orbiting Spacecraft

    Young-Joo Song

    2004-12-01

    Full Text Available An orbit propagation software for the Mars orbiting spacecraft has been developed and verified in preparations for the future Korean Mars missions. Dynamic model for Mars orbiting spacecraft has been studied, and Mars centered coordinate systems are utilized to express spacecraft state vectors. Coordinate corrections to the Mars centered coordinate system have been made to adjust the effects caused by Mars precession and nutation. After spacecraft enters Sphere of Influence (SOI of the Mars, the spacecraft experiences various perturbation effects as it approaches to Mars. Every possible perturbation effect is considered during integrations of spacecraft state vectors. The Mars50c gravity field model and the Mars-GRAM 2001 model are used to compute perturbation effects due to Mars gravity field and Mars atmospheric drag, respectively. To compute exact locations of other planets, JPL's DE405 ephemerides are used. Phobos and Deimos's ephemeris are computed using analytical method because their informations are not released with DE405. Mars Global Surveyor's mapping orbital data are used to verify the developed propagator performances. After one Martian day propagation (12 orbital periods, the results show about maximum ±5 meter errors, in every position state components(radial, cross-track and along-track, when compared to these from the Astrogator propagation in the Satellite Tool Kit. This result shows high reliability of the developed software which can be used to design near Mars missions for Korea, in future.

  18. Mammographic feature enhancement by multiscale analysis

    Laine, A.F.; Schuler, S.; Fan, J.; Huda, W.

    1994-01-01

    This paper introduces a novel approach for accomplishing mammographic feature analysis by overcomplete multiresolution representations. The authors show that efficient representations may be identified within a continuum of scale-space and used to enhance features of importance to mammography. Methods of contrast enhancement are described based on three overcomplete multiscale representations: (1) the dyadic wavelet transform (separable), (2) the var-phi-transform (nonseparable, nonorthogonal), and (3) the hexagonal wavelet transform (nonseparable). Multiscale edges identified within distinct levels of transform space provide local support for image enhancement. Mammograms are reconstructed from wavelet coefficients modified at one or more levels by local and global nonlinear operators. In each case, edges and gain parameters are identified adaptively by a measure of energy within each level of scale-space. The authors show quantitatively that transform coefficients, modified by adaptive nonlinear operators, can make more obvious unseen or barely seen features of mammography without requiring additional radiation. The results are compared with traditional image enhancement techniques by measuring the local contrast of known mammographic features. The authors demonstrate that features extracted from multiresolution representations can provide an adaptive mechanism for accomplishing local contrast enhancement. By improving the visualization of breast pathology, they can improve chances of early detection while requiring less time to evaluate mammograms for most patients

  19. Effects of Subscale Size and Shape on Global Energy Dissipation in a Multiscale Model of a Fiber-Reinforced Composite Exhibiting Post-Peak Strain Softening Using Abaqus and FEAMAC

    Pineda, Evan, J.; Bednarcyk, Brett, A.; Arnold, Steven, M.

    2012-01-01

    A mesh objective crack band model is implemented in the generalized method of cells (GMC) micromechanics model to predict failure of a composite repeating unit cell (RUC). The micromechanics calculations are achieved using the MAC/GMC core engine within the ImMAC suite of micromechanics codes, developed at the NASA Glenn Research Center. The microscale RUC is linked to a macroscale Abaqus/Standard finite element model using the FEAMAC multiscale framework (included in the ImMAC suite). The effects of the relationship between the characteristic length of the finite element and the size of the microscale RUC on the total energy dissipation of the multiscale model are investigated. A simple 2-D composite square subjected to uniaxial tension is used to demonstrate the effects of scaling the dimensions of the RUC such that the length of the sides of the RUC are equal to the characteristic length of the finite element. These results are compared to simulations where the size of the RUC is fixed, independent of the element size. Simulations are carried out for a variety of mesh densities and element shapes, including square and triangular. Results indicate that a consistent size and shape must be used to yield preserve energy dissipation across the scales.

  20. The Magnetospheric Multiscale Magnetometers

    Russell, C. T.; Anderson, B. J.; Baumjohann, W.; Bromund, K. R.; Dearborn, D.; Fischer, D.; Le, G.; Leinweber, H. K.; Leneman, D.; Magnes, W.; hide

    2014-01-01

    The success of the Magnetospheric Multiscale mission depends on the accurate measurement of the magnetic field on all four spacecraft. To ensure this success, two independently designed and built fluxgate magnetometers were developed, avoiding single-point failures. The magnetometers were dubbed the digital fluxgate (DFG), which uses an ASIC implementation and was supplied by the Space Research Institute of the Austrian Academy of Sciences and the analogue magnetometer (AFG) with a more traditional circuit board design supplied by the University of California, Los Angeles. A stringent magnetic cleanliness program was executed under the supervision of the Johns Hopkins University,s Applied Physics Laboratory. To achieve mission objectives, the calibration determined on the ground will be refined in space to ensure all eight magnetometers are precisely inter-calibrated. Near real-time data plays a key role in the transmission of high-resolution observations stored onboard so rapid processing of the low-resolution data is required. This article describes these instruments, the magnetic cleanliness program, and the instrument pre-launch calibrations, the planned in-flight calibration program, and the information flow that provides the data on the rapid time scale needed for mission success.

  1. Improved Mars Upper Atmosphere Climatology

    Bougher, S. W.

    2004-01-01

    The detailed characterization of the Mars upper atmosphere is important for future Mars aerobraking activities. Solar cycle, seasonal, and dust trends (climate) as well as planetary wave activity (weather) are crucial to quantify in order to improve our ability to reasonably depict the state of the Mars upper atmosphere over time. To date, our best information is found in the Mars Global Surveyor (MGS) Accelerometer (ACC) database collected during Phase 1 (Ls = 184 - 300; F10.7 = 70 - 90) and Phase 2 (Ls = 30 - 90; F10.7 = 90 - 150) of aerobraking. This database (100 - 170 km) consists of thermospheric densities, temperatures, and scale heights, providing our best constraints for exercising the coupled Mars General Circulation Model (MGCM) and the Mars Thermospheric General Circulation Model (MTGCM). The Planetary Data System (PDS) contains level 0 and 2 MGS Accelerometer data, corresponding to atmospheric densities along the orbit track. Level 3 products (densities, temperatures, and scale heights at constant altitudes) are also available in the PDS. These datasets provide the primary model constraints for the new MGCM-MTGCM simulations summarized in this report. Our strategy for improving the characterization of the Mars upper atmospheres using these models has been three-fold : (a) to conduct data-model comparisons using the latest MGS data covering limited climatic and weather conditions at Mars, (b) to upgrade the 15-micron cooling and near-IR heating rates in the MGCM and MTGCM codes for ad- dressing climatic variations (solar cycle and seasonal) important in linking the lower and upper atmospheres (including migrating tides), and (c) to exercise the detailed coupled MGCM and MTGCM codes to capture and diagnose the planetary wave (migrating plus non-migrating tidal) features throughout the Mars year. Products from this new suite of MGCM-MTGCM coupled simulations are being used to improve our predictions of the structure of the Mars upper atmosphere for the

  2. Mars Atmosphere Resource Verification INsitu (MARVIN) - In Situ Resource Demonstration for the Mars 2020 Mission

    Sanders, Gerald B.; Araghi, Koorosh; Ess, Kim M.; Valencia, Lisa M.; Muscatello, Anthony C.; Calle, Carlos I.; Clark, Larry; Iacomini, Christie

    2014-01-01

    The making of oxygen from resources in the Martian atmosphere, known as In Situ Resource Utilization (ISRU), has the potential to provide substantial benefits for future robotic and human exploration. In particular, the ability to produce oxygen on Mars for use in propulsion, life support, and power systems can provide significant mission benefits such as a reducing launch mass, lander size, and mission and crew risk. To advance ISRU for possible incorporation into future human missions to Mars, NASA proposed including an ISRU instrument on the Mars 2020 rover mission, through an announcement of opportunity (AO). The purpose of the the Mars Atmosphere Resource Verification INsitu or (MARVIN) instrument is to provide the first demonstration on Mars of oxygen production from acquired and stored Martian atmospheric carbon dioxide, as well as take measurements of atmospheric pressure and temperature, and of suspended dust particle sizes and amounts entrained in collected atmosphere gases at different times of the Mars day and year. The hardware performance and environmental data obtained will be critical for future ISRU systems that will reduce the mass of propellants and other consumables launched from Earth for robotic and human exploration, for better understanding of Mars dust and mitigation techniques to improve crew safety, and to help further define Mars global circulation models and better understand the regional atmospheric dynamics on Mars. The technologies selected for MARVIN are also scalable for future robotic sample return and human missions to Mars using ISRU.

  3. Multi-Scale Models for the Scale Interaction of Organized Tropical Convection

    Yang, Qiu

    Assessing the upscale impact of organized tropical convection from small spatial and temporal scales is a research imperative, not only for having a better understanding of the multi-scale structures of dynamical and convective fields in the tropics, but also for eventually helping in the design of new parameterization strategies to improve the next-generation global climate models. Here self-consistent multi-scale models are derived systematically by following the multi-scale asymptotic methods and used to describe the hierarchical structures of tropical atmospheric flows. The advantages of using these multi-scale models lie in isolating the essential components of multi-scale interaction and providing assessment of the upscale impact of the small-scale fluctuations onto the large-scale mean flow through eddy flux divergences of momentum and temperature in a transparent fashion. Specifically, this thesis includes three research projects about multi-scale interaction of organized tropical convection, involving tropical flows at different scaling regimes and utilizing different multi-scale models correspondingly. Inspired by the observed variability of tropical convection on multiple temporal scales, including daily and intraseasonal time scales, the goal of the first project is to assess the intraseasonal impact of the diurnal cycle on the planetary-scale circulation such as the Hadley cell. As an extension of the first project, the goal of the second project is to assess the intraseasonal impact of the diurnal cycle over the Maritime Continent on the Madden-Julian Oscillation. In the third project, the goals are to simulate the baroclinic aspects of the ITCZ breakdown and assess its upscale impact on the planetary-scale circulation over the eastern Pacific. These simple multi-scale models should be useful to understand the scale interaction of organized tropical convection and help improve the parameterization of unresolved processes in global climate models.

  4. Evaluating predictions of ICME arrival at Earth and Mars

    Falkenberg, Thea Vilstrup; Taktakishvili, A.; Pulkkinen, A.

    2011-01-01

    We present a study of interplanetary coronal mass ejection (ICME) propagation to Earth and Mars. Because of the significant space weather hazard posed by ICMEs, understanding and predicting their arrival and impact at Mars is important for current and future robotic and manned missions...... to the planet. We compare running ENLILv2.6 with coronal mass ejection (CME) input parameters from both a manual and an automated method. We analyze shock events identified at Mars in Mars Global Surveyor data in 2001 and 2003, when Earth and Mars were separated by...

  5. Solar radiation for Mars power systems

    Appelbaum, Joseph; Landis, Geoffrey A.

    1991-01-01

    Detailed information about the solar radiation characteristics on Mars are necessary for effective design of future planned solar energy systems operating on the surface of Mars. A procedure and solar radiation related data from which the diurnally and daily variation of the global, direct (or beam), and diffuse insolation on Mars are calculated, are presented. The radiation data are based on measured optical depth of the Martian atmosphere derived from images taken of the Sun with a special diode on the Viking Lander cameras; and computation based on multiple wavelength and multiple scattering of the solar radiation.

  6. Multiscale scenarios for nature futures

    Rosa, IMD

    2017-09-01

    Full Text Available & Evolution, vol. 1: 1416-1419 Multiscale scenarios for nature futures Rosa IMD Pereira HM Ferrier S Alkemade R Acosta LA Akcakaya HR den Belder E Fazel AM Fujimori S Sitas NE ABSTRACT: Targets for human development are increasingly...

  7. Multiscale mechanics of dynamical metamaterials

    Geers, M.G.D.; Kouznetsova, V.; Sridhar, A.; Krushynska, A.; Kleiber, M.; Burczynski, T.; Wilde, K.; Gorski, J.; Winkelmann, K.; Smakosz, L.

    2016-01-01

    This contribution focuses on the computational multi-scale solution of wave propagation phenomena in dynamic metamaterials. Taking the Bloch-Floquet solution for the standard elastic case as a point of departure, an extended scheme is presented to solve for heterogeneous visco-elastic materials. The

  8. Tectonic evolution of Mars

    Wise, D.U.; Golombek, M.P.; McGill, G.E.

    1979-01-01

    Any model for the tectonic evolution of Mars must account for two major crustal elements: the Tharsis bulge and the topographically low and lightly crated northern third of the planet. Ages determined by crater density indicate that both of these elements came into existence very early in Martian history, a conclusion that holds no matter which of the current crater density versus age curves is used. The size of these two major crustal elements and their sequential development suggest that both may be related to a global-scale internal process. It is proposed that the resurfacing of the northern third of Mars is related to subcrustal erosion and isostatic foundering during the life of a first-order convection cell. With the demise of the cell, denser segregations of metallic materials began to coalesce as a gravitatively unstable layer which finally overturned to form the core. In the overturn, lighter crustal materials was shifted laterally and underplated beneath Tharsis to cause rapid and permanent isostatic rise. This was followed by a long-lived thermal phase produced by the hot underplate and by the gravitative energy of core formation slowly making its way to the surface to produce the Tharsis volcanics

  9. The humanation of Mars

    David, L. W.

    Early developments related to human excursions to Mars are examined, taking into account plans considered by von Braun, and the 'ambitious goal of a manned flight to Mars by the end of the century', proposed at the launch of Apollo 11. In response to public reaction, plans for manned flights to Mars in the immediate future were given up, and unmanned reconnaissance of Mars was continued. An investigation is conducted concerning the advantages of manned exploration of Mars in comparison to a study by unmanned space probes, and arguments regarding a justification for interplanetary flight to Mars are discussed. Attention is given to the possibility to consider Mars as a 'back-up' planet for preserving earth life, an international Mars expedition as a world peace project, the role of Mars in connection with resource utilization considerations, and questions of exploration ethics.

  10. Multiscale Thermohydrologic Model

    T. Buscheck

    2004-10-12

    The purpose of the multiscale thermohydrologic model (MSTHM) is to predict the possible range of thermal-hydrologic conditions, resulting from uncertainty and variability, in the repository emplacement drifts, including the invert, and in the adjoining host rock for the repository at Yucca Mountain. Thus, the goal is to predict the range of possible thermal-hydrologic conditions across the repository; this is quite different from predicting a single expected thermal-hydrologic response. The MSTHM calculates the following thermal-hydrologic parameters: temperature, relative humidity, liquid-phase saturation, evaporation rate, air-mass fraction, gas-phase pressure, capillary pressure, and liquid- and gas-phase fluxes (Table 1-1). These thermal-hydrologic parameters are required to support ''Total System Performance Assessment (TSPA) Model/Analysis for the License Application'' (BSC 2004 [DIRS 168504]). The thermal-hydrologic parameters are determined as a function of position along each of the emplacement drifts and as a function of waste package type. These parameters are determined at various reference locations within the emplacement drifts, including the waste package and drip-shield surfaces and in the invert. The parameters are also determined at various defined locations in the adjoining host rock. The MSTHM uses data obtained from the data tracking numbers (DTNs) listed in Table 4.1-1. The majority of those DTNs were generated from the following analyses and model reports: (1) ''UZ Flow Model and Submodels'' (BSC 2004 [DIRS 169861]); (2) ''Development of Numerical Grids for UZ Flow and Transport Modeling'' (BSC 2004); (3) ''Calibrated Properties Model'' (BSC 2004 [DIRS 169857]); (4) ''Thermal Conductivity of the Potential Repository Horizon'' (BSC 2004 [DIRS 169854]); (5) ''Thermal Conductivity of the Non-Repository Lithostratigraphic Layers

  11. Mars At Opposition

    1995-01-01

    These NASA Hubble Space Telescope views provide the most detailed complete global coverage of the red planet Mars ever seen from Earth. The pictures were taken on February 25, 1995, when Mars was at a distance of 65 million miles (103 million km).To the surprise of researchers, Mars is cloudier than seen in previous years. This means the planet is cooler and drier, because water vapor in the atmosphere freezes out to form ice-crystal clouds. Hubble resolves Martian surface features with a level of detail only exceeded by planetary probes, such as impact craters and other features as small as 30 miles (50 kilometers) across.[Tharsis region] - A crescent-shaped cloud just right of center identifies the immense shield volcano Olympus Mons, which is 340 miles (550 km) across at its base. Warm afternoon air pushed up over the summit forms ice-crystal clouds downwind from the volcano. Farther to the east (right) a line of clouds forms over a row of three extinct volcanoes which are from north to south: Ascraeus Mons, Pavonis Mons, Arsia Mons. It's part of an unusual, recurring 'W'-shaped cloud formation that once mystified earlier ground-based observers.[Valles Marineris region] - The 16 mile-high volcano Ascraeus Mons pokes through the cloud deck along the western (left) limb of the planet. Other interesting geologic features include (lower left) Valles Marineris, an immense rift valley the length of the continental United States. Near the image center lies the Chryse basin made up of cratered and chaotic terrain. The oval-looking Argyre impact basin (bottom) appears white due to clouds or frost.[Syrtis Major region] - The dark 'shark fin' feature left of center is Syrtis Major. Below it the giant impact basin Hellas. Clouds cover several great volcanos in the Elysium region near the eastern (right) limb. As clearly seen in the Hubble images, past dust storms in Mars' southern hemisphere have scoured the plains of fine light dust and transported the dust northward. This

  12. Seasonal and Static Gravity Field of Mars from MGS, Mars Odyssey and MRO Radio Science

    Genova, Antonio; Goossens, Sander; Lemoine, Frank G.; Mazarico, Erwan; Neumann, Gregory A.; Smith, David E.; Zuber, Maria T.

    2016-01-01

    We present a spherical harmonic solution of the static gravity field of Mars to degree and order 120, GMM-3, that has been calculated using the Deep Space Network tracking data of the NASA Mars missions, Mars Global Surveyor (MGS), Mars Odyssey (ODY), and the Mars Reconnaissance Orbiter (MRO). We have also jointly determined spherical harmonic solutions for the static and time-variable gravity field of Mars, and the Mars k 2 Love numbers, exclusive of the gravity contribution of the atmosphere. Consequently, the retrieved time-varying gravity coefficients and the Love number k 2 solely yield seasonal variations in the mass of the polar caps and the solid tides of Mars, respectively. We obtain a Mars Love number k 2 of 0.1697 +/-0.0027 (3- sigma). The inclusion of MRO tracking data results in improved seasonal gravity field coefficients C 30 and, for the first time, C 50 . Refinements of the atmospheric model in our orbit determination program have allowed us to monitor the odd zonal harmonic C 30 for approx.1.5 solar cycles (16 years). This gravity model shows improved correlations with MOLA topography up to 15% larger at higher harmonics ( l = 60–80) than previous solutions.

  13. Mission Mars India's quest for the red planet

    Lele, Ajey

    2014-01-01

    The objective of the book is to find an answer to the rationale behind the human quest for the Mars exploration. As a comprehensive assessment for this query is undertaken, it is realized that the basic question ‘Why Mars?’ seeks various responses from technological, economic and geopolitical to strategic perspectives. The book is essentially targeted to understand India’s desire to reach Mars. In the process, it also undertakes some implicit questioning of Mars programmes of various other states essentially to facilitate the setting up of the context for an assessment.   The book is divided into two parts: Part I: This covers both science and politics associated with Mars missions in global scenario and discusses the salient features of various Mars Missions undertaken by various countries. Part II: This provides details in regards to India’s Mars Mission.

  14. MULTISCALE THERMOHYDROLOGIC MODEL

    T. Buscheck

    2005-01-01

    The intended purpose of the multiscale thermohydrologic model (MSTHM) is to predict the possible range of thermal-hydrologic conditions, resulting from uncertainty and variability, in the repository emplacement drifts, including the invert, and in the adjoining host rock for the repository at Yucca Mountain. The goal of the MSTHM is to predict a reasonable range of possible thermal-hydrologic conditions within the emplacement drift. To be reasonable, this range includes the influence of waste-package-to-waste-package heat output variability relevant to the license application design, as well as the influence of uncertainty and variability in the geologic and hydrologic conditions relevant to predicting the thermal-hydrologic response in emplacement drifts. This goal is quite different from the goal of a model to predict a single expected thermal-hydrologic response. As a result, the development and validation of the MSTHM and the associated analyses using this model are focused on the goal of predicting a reasonable range of thermal-hydrologic conditions resulting from parametric uncertainty and waste-package-to-waste-package heat-output variability. Thermal-hydrologic conditions within emplacement drifts depend primarily on thermal-hydrologic conditions in the host rock at the drift wall and on the temperature difference between the drift wall and the drip-shield and waste-package surfaces. Thus, the ability to predict a reasonable range of relevant in-drift MSTHM output parameters (e.g., temperature and relative humidity) is based on valid predictions of thermal-hydrologic processes in the host rock, as well as valid predictions of heat-transfer processes between the drift wall and the drip-shield and waste-package surfaces. Because the invert contains crushed gravel derived from the host rock, the invert is, in effect, an extension of the host rock, with thermal and hydrologic properties that have been modified by virtue of the crushing (and the resulting

  15. The Magnetospheric Multiscale Mission

    Burch, James

    Magnetospheric Multiscale (MMS), a NASA four-spacecraft mission scheduled for launch in November 2014, will investigate magnetic reconnection in the boundary regions of the Earth’s magnetosphere, particularly along its dayside boundary with the solar wind and the neutral sheet in the magnetic tail. Among the important questions about reconnection that will be addressed are the following: Under what conditions can magnetic-field energy be converted to plasma energy by the annihilation of magnetic field through reconnection? How does reconnection vary with time, and what factors influence its temporal behavior? What microscale processes are responsible for reconnection? What determines the rate of reconnection? In order to accomplish its goals the MMS spacecraft must probe both those regions in which the magnetic fields are very nearly antiparallel and regions where a significant guide field exists. From previous missions we know the approximate speeds with which reconnection layers move through space to be from tens to hundreds of km/s. For electron skin depths of 5 to 10 km, the full 3D electron population (10 eV to above 20 keV) has to be sampled at rates greater than 10/s. The MMS Fast-Plasma Instrument (FPI) will sample electrons at greater than 30/s. Because the ion skin depth is larger, FPI will make full ion measurements at rates of greater than 6/s. 3D E-field measurements will be made by MMS once every ms. MMS will use an Active Spacecraft Potential Control device (ASPOC), which emits indium ions to neutralize the photoelectron current and keep the spacecraft from charging to more than +4 V. Because ion dynamics in Hall reconnection depend sensitively on ion mass, MMS includes a new-generation Hot Plasma Composition Analyzer (HPCA) that corrects problems with high proton fluxes that have prevented accurate ion-composition measurements near the dayside magnetospheric boundary. Finally, Energetic Particle Detector (EPD) measurements of electrons and

  16. MULTISCALE THERMOHYDROLOGIC MODEL

    T. Buscheck

    2005-07-07

    The intended purpose of the multiscale thermohydrologic model (MSTHM) is to predict the possible range of thermal-hydrologic conditions, resulting from uncertainty and variability, in the repository emplacement drifts, including the invert, and in the adjoining host rock for the repository at Yucca Mountain. The goal of the MSTHM is to predict a reasonable range of possible thermal-hydrologic conditions within the emplacement drift. To be reasonable, this range includes the influence of waste-package-to-waste-package heat output variability relevant to the license application design, as well as the influence of uncertainty and variability in the geologic and hydrologic conditions relevant to predicting the thermal-hydrologic response in emplacement drifts. This goal is quite different from the goal of a model to predict a single expected thermal-hydrologic response. As a result, the development and validation of the MSTHM and the associated analyses using this model are focused on the goal of predicting a reasonable range of thermal-hydrologic conditions resulting from parametric uncertainty and waste-package-to-waste-package heat-output variability. Thermal-hydrologic conditions within emplacement drifts depend primarily on thermal-hydrologic conditions in the host rock at the drift wall and on the temperature difference between the drift wall and the drip-shield and waste-package surfaces. Thus, the ability to predict a reasonable range of relevant in-drift MSTHM output parameters (e.g., temperature and relative humidity) is based on valid predictions of thermal-hydrologic processes in the host rock, as well as valid predictions of heat-transfer processes between the drift wall and the drip-shield and waste-package surfaces. Because the invert contains crushed gravel derived from the host rock, the invert is, in effect, an extension of the host rock, with thermal and hydrologic properties that have been modified by virtue of the crushing (and the resulting

  17. Parallel multiscale simulations of a brain aneurysm

    Grinberg, Leopold [Division of Applied Mathematics, Brown University, Providence, RI 02912 (United States); Fedosov, Dmitry A. [Institute of Complex Systems and Institute for Advanced Simulation, Forschungszentrum Jülich, Jülich 52425 (Germany); Karniadakis, George Em, E-mail: george_karniadakis@brown.edu [Division of Applied Mathematics, Brown University, Providence, RI 02912 (United States)

    2013-07-01

    Cardiovascular pathologies, such as a brain aneurysm, are affected by the global blood circulation as well as by the local microrheology. Hence, developing computational models for such cases requires the coupling of disparate spatial and temporal scales often governed by diverse mathematical descriptions, e.g., by partial differential equations (continuum) and ordinary differential equations for discrete particles (atomistic). However, interfacing atomistic-based with continuum-based domain discretizations is a challenging problem that requires both mathematical and computational advances. We present here a hybrid methodology that enabled us to perform the first multiscale simulations of platelet depositions on the wall of a brain aneurysm. The large scale flow features in the intracranial network are accurately resolved by using the high-order spectral element Navier–Stokes solver NεκTαr. The blood rheology inside the aneurysm is modeled using a coarse-grained stochastic molecular dynamics approach (the dissipative particle dynamics method) implemented in the parallel code LAMMPS. The continuum and atomistic domains overlap with interface conditions provided by effective forces computed adaptively to ensure continuity of states across the interface boundary. A two-way interaction is allowed with the time-evolving boundary of the (deposited) platelet clusters tracked by an immersed boundary method. The corresponding heterogeneous solvers (NεκTαr and LAMMPS) are linked together by a computational multilevel message passing interface that facilitates modularity and high parallel efficiency. Results of multiscale simulations of clot formation inside the aneurysm in a patient-specific arterial tree are presented. We also discuss the computational challenges involved and present scalability results of our coupled solver on up to 300 K computer processors. Validation of such coupled atomistic-continuum models is a main open issue that has to be addressed in

  18. Parallel multiscale simulations of a brain aneurysm

    Grinberg, Leopold; Fedosov, Dmitry A.; Karniadakis, George Em

    2013-01-01

    Cardiovascular pathologies, such as a brain aneurysm, are affected by the global blood circulation as well as by the local microrheology. Hence, developing computational models for such cases requires the coupling of disparate spatial and temporal scales often governed by diverse mathematical descriptions, e.g., by partial differential equations (continuum) and ordinary differential equations for discrete particles (atomistic). However, interfacing atomistic-based with continuum-based domain discretizations is a challenging problem that requires both mathematical and computational advances. We present here a hybrid methodology that enabled us to perform the first multiscale simulations of platelet depositions on the wall of a brain aneurysm. The large scale flow features in the intracranial network are accurately resolved by using the high-order spectral element Navier–Stokes solver NεκTαr. The blood rheology inside the aneurysm is modeled using a coarse-grained stochastic molecular dynamics approach (the dissipative particle dynamics method) implemented in the parallel code LAMMPS. The continuum and atomistic domains overlap with interface conditions provided by effective forces computed adaptively to ensure continuity of states across the interface boundary. A two-way interaction is allowed with the time-evolving boundary of the (deposited) platelet clusters tracked by an immersed boundary method. The corresponding heterogeneous solvers (NεκTαr and LAMMPS) are linked together by a computational multilevel message passing interface that facilitates modularity and high parallel efficiency. Results of multiscale simulations of clot formation inside the aneurysm in a patient-specific arterial tree are presented. We also discuss the computational challenges involved and present scalability results of our coupled solver on up to 300 K computer processors. Validation of such coupled atomistic-continuum models is a main open issue that has to be addressed in

  19. Geology of Mars

    Soderblom, L.A.

    1988-01-01

    The geology of Mars and the results of the Mariner 4, 6/7, and 9 missions and the Viking mission are reviewed. The Mars chronology and geologic modification are examined, including chronological models for the inactive planet, the active planet, and crater flux. The importance of surface materials is discussed and a multispectral map of Mars is presented. Suggestions are given for further studies of the geology of Mars using the Viking data. 5 references

  20. Mars: The Viking Discoveries.

    French, Bevan M.

    This booklet describes the results of NASA's Viking spacecraft on Mars. It is intended to be useful for the teacher of basic courses in earth science, space science, astronomy, physics, or geology, but is also of interest to the well-informed layman. Topics include why we should study Mars, how the Viking spacecraft works, the winds of Mars, the…

  1. Numerical Analysis of Multiscale Computations

    Engquist, Björn; Tsai, Yen-Hsi R

    2012-01-01

    This book is a snapshot of current research in multiscale modeling, computations and applications. It covers fundamental mathematical theory, numerical algorithms as well as practical computational advice for analysing single and multiphysics models containing a variety of scales in time and space. Complex fluids, porous media flow and oscillatory dynamical systems are treated in some extra depth, as well as tools like analytical and numerical homogenization, and fast multipole method.

  2. Community effort endorsing multiscale modelling, multiscale data science and multiscale computing for systems medicine.

    Zanin, Massimiliano; Chorbev, Ivan; Stres, Blaz; Stalidzans, Egils; Vera, Julio; Tieri, Paolo; Castiglione, Filippo; Groen, Derek; Zheng, Huiru; Baumbach, Jan; Schmid, Johannes A; Basilio, José; Klimek, Peter; Debeljak, Nataša; Rozman, Damjana; Schmidt, Harald H H W

    2017-12-05

    Systems medicine holds many promises, but has so far provided only a limited number of proofs of principle. To address this road block, possible barriers and challenges of translating systems medicine into clinical practice need to be identified and addressed. The members of the European Cooperation in Science and Technology (COST) Action CA15120 Open Multiscale Systems Medicine (OpenMultiMed) wish to engage the scientific community of systems medicine and multiscale modelling, data science and computing, to provide their feedback in a structured manner. This will result in follow-up white papers and open access resources to accelerate the clinical translation of systems medicine. © The Author 2017. Published by Oxford University Press.

  3. Differential Geometry Based Multiscale Models

    Wei, Guo-Wei

    2010-01-01

    Large chemical and biological systems such as fuel cells, ion channels, molecular motors, and viruses are of great importance to the scientific community and public health. Typically, these complex systems in conjunction with their aquatic environment pose a fabulous challenge to theoretical description, simulation, and prediction. In this work, we propose a differential geometry based multiscale paradigm to model complex macromolecular systems, and to put macroscopic and microscopic descriptions on an equal footing. In our approach, the differential geometry theory of surfaces and geometric measure theory are employed as a natural means to couple the macroscopic continuum mechanical description of the aquatic environment with the microscopic discrete atom-istic description of the macromolecule. Multiscale free energy functionals, or multiscale action functionals are constructed as a unified framework to derive the governing equations for the dynamics of different scales and different descriptions. Two types of aqueous macromolecular complexes, ones that are near equilibrium and others that are far from equilibrium, are considered in our formulations. We show that generalized Navier–Stokes equations for the fluid dynamics, generalized Poisson equations or generalized Poisson–Boltzmann equations for electrostatic interactions, and Newton's equation for the molecular dynamics can be derived by the least action principle. These equations are coupled through the continuum-discrete interface whose dynamics is governed by potential driven geometric flows. Comparison is given to classical descriptions of the fluid and electrostatic interactions without geometric flow based micro-macro interfaces. The detailed balance of forces is emphasized in the present work. We further extend the proposed multiscale paradigm to micro-macro analysis of electrohydrodynamics, electrophoresis, fuel cells, and ion channels. We derive generalized Poisson–Nernst–Planck equations that

  4. Differential geometry based multiscale models.

    Wei, Guo-Wei

    2010-08-01

    Large chemical and biological systems such as fuel cells, ion channels, molecular motors, and viruses are of great importance to the scientific community and public health. Typically, these complex systems in conjunction with their aquatic environment pose a fabulous challenge to theoretical description, simulation, and prediction. In this work, we propose a differential geometry based multiscale paradigm to model complex macromolecular systems, and to put macroscopic and microscopic descriptions on an equal footing. In our approach, the differential geometry theory of surfaces and geometric measure theory are employed as a natural means to couple the macroscopic continuum mechanical description of the aquatic environment with the microscopic discrete atomistic description of the macromolecule. Multiscale free energy functionals, or multiscale action functionals are constructed as a unified framework to derive the governing equations for the dynamics of different scales and different descriptions. Two types of aqueous macromolecular complexes, ones that are near equilibrium and others that are far from equilibrium, are considered in our formulations. We show that generalized Navier-Stokes equations for the fluid dynamics, generalized Poisson equations or generalized Poisson-Boltzmann equations for electrostatic interactions, and Newton's equation for the molecular dynamics can be derived by the least action principle. These equations are coupled through the continuum-discrete interface whose dynamics is governed by potential driven geometric flows. Comparison is given to classical descriptions of the fluid and electrostatic interactions without geometric flow based micro-macro interfaces. The detailed balance of forces is emphasized in the present work. We further extend the proposed multiscale paradigm to micro-macro analysis of electrohydrodynamics, electrophoresis, fuel cells, and ion channels. We derive generalized Poisson-Nernst-Planck equations that are

  5. Mars Drilling Status

    Mandell, Humboldt, C., Jr.

    2002-01-01

    This slide presentation reviews the current status of work to explore Mars beneath the surface of planet. One of the objective of this work is to enable further exploration of Mars by humans. One of the requirements for this is to find water on Mars. The presences of water is critical for Human Exploration and a permanent presence on Mars. If water is present beneath the surface it is the best chance of finding life on Mars. The presentation includes a timeline showing the robotic missions, those that have already been on Mars, and planned missions, an explanation of why do we want to drill on Mars, and some of the challenges, Also include are reviews of a missions that would drill 200 and 4,000 to 6,000 meters into the Martian bedrock, and a overview description of the drill. There is a view of some places where we have hopes of finding water.

  6. Multiscale Simulation of Breaking Wave Impacts

    Lindberg, Ole

    compare reasonably well. The incompressible and inviscid ALE-WLS model is coupled with the potential flow model of Engsig-Karup et al. [2009], to perform multiscale calculation of breaking wave impacts on a vertical breakwater. The potential flow model provides accurate calculation of the wave...... with a potential flow model to provide multiscale calculation of forces from breaking wave impacts on structures....

  7. Foundations for a multiscale collaborative Earth model

    Afanasiev, M.

    2015-11-11

    of the CSEM development, the broad global updates mostly act to remove artefacts from the assembly of the initial CSEM. During the future evolution of the CSEM, the reference data set will be used to account for the influence of small-scale refinements on large-scale global structure. The CSEM as a computational framework is intended to help bridging the gap between local, regional and global tomography, and to contribute to the development of a global multiscale Earth model. While the current construction serves as a first proof of concept, future refinements and additions will require community involvement, which is welcome at this stage already.

  8. Multivariate refined composite multiscale entropy analysis

    Humeau-Heurtier, Anne

    2016-01-01

    Multiscale entropy (MSE) has become a prevailing method to quantify signals complexity. MSE relies on sample entropy. However, MSE may yield imprecise complexity estimation at large scales, because sample entropy does not give precise estimation of entropy when short signals are processed. A refined composite multiscale entropy (RCMSE) has therefore recently been proposed. Nevertheless, RCMSE is for univariate signals only. The simultaneous analysis of multi-channel (multivariate) data often over-performs studies based on univariate signals. We therefore introduce an extension of RCMSE to multivariate data. Applications of multivariate RCMSE to simulated processes reveal its better performances over the standard multivariate MSE. - Highlights: • Multiscale entropy quantifies data complexity but may be inaccurate at large scale. • A refined composite multiscale entropy (RCMSE) has therefore recently been proposed. • Nevertheless, RCMSE is adapted to univariate time series only. • We herein introduce an extension of RCMSE to multivariate data. • It shows better performances than the standard multivariate multiscale entropy.

  9. The Adaptive Multi-scale Simulation Infrastructure

    Tobin, William R. [Rensselaer Polytechnic Inst., Troy, NY (United States)

    2015-09-01

    The Adaptive Multi-scale Simulation Infrastructure (AMSI) is a set of libraries and tools developed to support the development, implementation, and execution of general multimodel simulations. Using a minimal set of simulation meta-data AMSI allows for minimally intrusive work to adapt existent single-scale simulations for use in multi-scale simulations. Support for dynamic runtime operations such as single- and multi-scale adaptive properties is a key focus of AMSI. Particular focus has been spent on the development on scale-sensitive load balancing operations to allow single-scale simulations incorporated into a multi-scale simulation using AMSI to use standard load-balancing operations without affecting the integrity of the overall multi-scale simulation.

  10. Multiscale empirical interpolation for solving nonlinear PDEs

    Calo, Victor M.

    2014-12-01

    In this paper, we propose a multiscale empirical interpolation method for solving nonlinear multiscale partial differential equations. The proposed method combines empirical interpolation techniques and local multiscale methods, such as the Generalized Multiscale Finite Element Method (GMsFEM). To solve nonlinear equations, the GMsFEM is used to represent the solution on a coarse grid with multiscale basis functions computed offline. Computing the GMsFEM solution involves calculating the system residuals and Jacobians on the fine grid. We use empirical interpolation concepts to evaluate these residuals and Jacobians of the multiscale system with a computational cost which is proportional to the size of the coarse-scale problem rather than the fully-resolved fine scale one. The empirical interpolation method uses basis functions which are built by sampling the nonlinear function we want to approximate a limited number of times. The coefficients needed for this approximation are computed in the offline stage by inverting an inexpensive linear system. The proposed multiscale empirical interpolation techniques: (1) divide computing the nonlinear function into coarse regions; (2) evaluate contributions of nonlinear functions in each coarse region taking advantage of a reduced-order representation of the solution; and (3) introduce multiscale proper-orthogonal-decomposition techniques to find appropriate interpolation vectors. We demonstrate the effectiveness of the proposed methods on several nonlinear multiscale PDEs that are solved with Newton\\'s methods and fully-implicit time marching schemes. Our numerical results show that the proposed methods provide a robust framework for solving nonlinear multiscale PDEs on a coarse grid with bounded error and significant computational cost reduction.

  11. Peridynamic Multiscale Finite Element Methods

    Costa, Timothy [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bond, Stephen D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Littlewood, David John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Moore, Stan Gerald [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-12-01

    The problem of computing quantum-accurate design-scale solutions to mechanics problems is rich with applications and serves as the background to modern multiscale science research. The prob- lem can be broken into component problems comprised of communicating across adjacent scales, which when strung together create a pipeline for information to travel from quantum scales to design scales. Traditionally, this involves connections between a) quantum electronic structure calculations and molecular dynamics and between b) molecular dynamics and local partial differ- ential equation models at the design scale. The second step, b), is particularly challenging since the appropriate scales of molecular dynamic and local partial differential equation models do not overlap. The peridynamic model for continuum mechanics provides an advantage in this endeavor, as the basic equations of peridynamics are valid at a wide range of scales limiting from the classical partial differential equation models valid at the design scale to the scale of molecular dynamics. In this work we focus on the development of multiscale finite element methods for the peridynamic model, in an effort to create a mathematically consistent channel for microscale information to travel from the upper limits of the molecular dynamics scale to the design scale. In particular, we first develop a Nonlocal Multiscale Finite Element Method which solves the peridynamic model at multiple scales to include microscale information at the coarse-scale. We then consider a method that solves a fine-scale peridynamic model to build element-support basis functions for a coarse- scale local partial differential equation model, called the Mixed Locality Multiscale Finite Element Method. Given decades of research and development into finite element codes for the local partial differential equation models of continuum mechanics there is a strong desire to couple local and nonlocal models to leverage the speed and state of the

  12. An Online Generalized Multiscale Discontinuous Galerkin Method (GMsDGM) for Flows in Heterogeneous Media

    Chung, Eric T.

    2017-02-07

    Offline computation is an essential component in most multiscale model reduction techniques. However, there are multiscale problems in which offline procedure is insufficient to give accurate representations of solutions, due to the fact that offline computations are typically performed locally and global information is missing in these offline information. To tackle this difficulty, we develop an online local adaptivity technique for local multiscale model reduction problems. We design new online basis functions within Discontinuous Galerkin method based on local residuals and some optimally estimates. The resulting basis functions are able to capture the solution efficiently and accurately, and are added to the approximation iteratively. Moreover, we show that the iterative procedure is convergent with a rate independent of physical scales if the initial space is chosen carefully. Our analysis also gives a guideline on how to choose the initial space. We present some numerical examples to show the performance of the proposed method.

  13. Image classification using multiscale information fusion based on saliency driven nonlinear diffusion filtering.

    Hu, Weiming; Hu, Ruiguang; Xie, Nianhua; Ling, Haibin; Maybank, Stephen

    2014-04-01

    In this paper, we propose saliency driven image multiscale nonlinear diffusion filtering. The resulting scale space in general preserves or even enhances semantically important structures such as edges, lines, or flow-like structures in the foreground, and inhibits and smoothes clutter in the background. The image is classified using multiscale information fusion based on the original image, the image at the final scale at which the diffusion process converges, and the image at a midscale. Our algorithm emphasizes the foreground features, which are important for image classification. The background image regions, whether considered as contexts of the foreground or noise to the foreground, can be globally handled by fusing information from different scales. Experimental tests of the effectiveness of the multiscale space for the image classification are conducted on the following publicly available datasets: 1) the PASCAL 2005 dataset; 2) the Oxford 102 flowers dataset; and 3) the Oxford 17 flowers dataset, with high classification rates.

  14. Quick trips to Mars

    Hornung, R.

    1991-01-01

    The design of a Mars Mission Vehicle that would have to be launched by two very heavy lift launch vehicles is described along with plans for a mission to Mars. The vehicle has three nuclear engine for rocket vehicle application (NERVA) boosters with a fourth in the center that acts as a dual mode system. The fourth generates electrical power while in route, but it also helps lift the vehicle out of earth orbit. A Mars Ascent Vehicle (MAV), a Mars transfer vehicle stage, and a Mars Excursion Vehicle (MEV) are located on the front end of this vehicle. Other aspects of this research including aerobraking, heat shielding, nuclear thermal rocket engines, a mars mission summary, closed Brayton cycle with and without regeneration, liquid hydrogen propellant storage, etc. are addressed

  15. Implementation of Grid-computing Framework for Simulation in Multi-scale Structural Analysis

    Data Iranata

    2010-05-01

    Full Text Available A new grid-computing framework for simulation in multi-scale structural analysis is presented. Two levels of parallel processing will be involved in this framework: multiple local distributed computing environments connected by local network to form a grid-based cluster-to-cluster distributed computing environment. To successfully perform the simulation, a large-scale structural system task is decomposed into the simulations of a simplified global model and several detailed component models using various scales. These correlated multi-scale structural system tasks are distributed among clusters and connected together in a multi-level hierarchy and then coordinated over the internet. The software framework for supporting the multi-scale structural simulation approach is also presented. The program architecture design allows the integration of several multi-scale models as clients and servers under a single platform. To check its feasibility, a prototype software system has been designed and implemented to perform the proposed concept. The simulation results show that the software framework can increase the speedup performance of the structural analysis. Based on this result, the proposed grid-computing framework is suitable to perform the simulation of the multi-scale structural analysis.

  16. Fast online generalized multiscale finite element method using constraint energy minimization

    Chung, Eric T.; Efendiev, Yalchin; Leung, Wing Tat

    2018-02-01

    Local multiscale methods often construct multiscale basis functions in the offline stage without taking into account input parameters, such as source terms, boundary conditions, and so on. These basis functions are then used in the online stage with a specific input parameter to solve the global problem at a reduced computational cost. Recently, online approaches have been introduced, where multiscale basis functions are adaptively constructed in some regions to reduce the error significantly. In multiscale methods, it is desired to have only 1-2 iterations to reduce the error to a desired threshold. Using Generalized Multiscale Finite Element Framework [10], it was shown that by choosing sufficient number of offline basis functions, the error reduction can be made independent of physical parameters, such as scales and contrast. In this paper, our goal is to improve this. Using our recently proposed approach [4] and special online basis construction in oversampled regions, we show that the error reduction can be made sufficiently large by appropriately selecting oversampling regions. Our numerical results show that one can achieve a three order of magnitude error reduction, which is better than our previous methods. We also develop an adaptive algorithm and enrich in selected regions with large residuals. In our adaptive method, we show that the convergence rate can be determined by a user-defined parameter and we confirm this by numerical simulations. The analysis of the method is presented.

  17. Planetary Protection Issues in the Human Exploration of Mars

    Criswell, Marvin E.; Race, M. S.; Rummel, J. D.; Baker, A.

    2005-01-01

    This workshop report, long delayed, is the first 21st century contribution to what will likely be a series of reports examining the effects of human exploration on the overall scientific study of Mars. The considerations of human-associated microbial contamination were last studied in a 1990 workshop ("Planetary Protection Issues and Future Mars Missions," NASA CP-10086, 1991), but the timing of that workshop allowed neither a careful examination of the full range of issues, nor an appreciation for the Mars that has been revealed by the Mars Global Surveyor and Mars Pathfinder missions. Future workshops will also have the advantage of Mars Odyssey, the Mars Exploration Rover missions, and ESA's Mars Express, but the Pingree Park workshop reported here had both the NCR's (1992) concern that "Missions carrying humans to Mars will contaminate the planet" and over a decade of careful study of human exploration objectives to guide them and to reconcile. A daunting challenge, and one that is not going to be simple (as the working title of this meeting, "When Ecologies Collide?" might suggest), it is clear that the planetary protection issues will have to be addressed to enable human explorers to safely and competently extend out knowledge about Mars, and its potential as a home for life whether martian or human.

  18. Mars at Opposition

    Riddle, Bob

    2010-01-01

    On January 29, Mars will reach opposition, a point along its orbit around the Sun where Mars will be directly opposite from the Sun in a two-planet and Sun line-up with the Earth in between. At this opposition, the Earth and Mars will be separated by nearly 100 million km. An opposition is similar to a full Moon in that the planet at opposition…

  19. History of Mars

    Lewis, J.S.

    1988-01-01

    The origin and early history of Mars and the relationship between Mars and the other planets are reviewed. The solar system formation and planetary differentiation are examined using data from planetary missions. Different views of Mars are presented, showing how ideas about the planet have changed as the amount of available observational data has increased. Viking aerography and surface characterization are discussed, including the nature of specific atmospheric components and the implications of surface phenomena. Models for the planetary formation and accretion processes are considered. The value of future missions to Mars is stressed

  20. Mars Stratigraphy Mission

    Budney, C. J.; Miller, S. L.; Cutts, J. A.

    2000-01-01

    The Mars Stratigraphy Mission lands a rover on the surface of Mars which descends down a cliff in Valles Marineris to study the stratigraphy. The rover carries a unique complement of instruments to analyze and age-date materials encountered during descent past 2 km of strata. The science objective for the Mars Stratigraphy Mission is to identify the geologic history of the layered deposits in the Valles Marineris region of Mars. This includes constraining the time interval for formation of these deposits by measuring the ages of various layers and determining the origin of the deposits (volcanic or sedimentary) by measuring their composition and imaging their morphology.

  1. Multiscale modelling for tokamak pedestals

    Abel, I. G.

    2018-04-01

    Pedestal modelling is crucial to predict the performance of future fusion devices. Current modelling efforts suffer either from a lack of kinetic physics, or an excess of computational complexity. To ameliorate these problems, we take a first-principles multiscale approach to the pedestal. We will present three separate sets of equations, covering the dynamics of edge localised modes (ELMs), the inter-ELM pedestal and pedestal turbulence, respectively. Precisely how these equations should be coupled to each other is covered in detail. This framework is completely self-consistent; it is derived from first principles by means of an asymptotic expansion of the fundamental Vlasov-Landau-Maxwell system in appropriate small parameters. The derivation exploits the narrowness of the pedestal region, the smallness of the thermal gyroradius and the low plasma (the ratio of thermal to magnetic pressures) typical of current pedestal operation to achieve its simplifications. The relationship between this framework and gyrokinetics is analysed, and possibilities to directly match our systems of equations onto multiscale gyrokinetics are explored. A detailed comparison between our model and other models in the literature is performed. Finally, the potential for matching this framework onto an open-field-line region is briefly discussed.

  2. Multifunctional multiscale composites: Processing, modeling and characterization

    Qiu, Jingjing

    Carbon nanotubes (CNTs) demonstrate extraordinary properties and show great promise in enhancing out-of-plane properties of traditional polymer/fiber composites and enabling functionality. However, current manufacturing challenges hinder the realization of their potential. In the dissertation research, both experimental and computational efforts have been conducted to investigate effective manufacturing techniques of CNT integrated multiscale composites. The fabricated composites demonstrated significant improvements in physical properties, such as tensile strength, tensile modulus, inter-laminar shear strength, thermal dimension stability and electrical conductivity. Such multiscale composites were truly multifunctional with the addition of CNTs. Furthermore, a novel hierarchical multiscale modeling method was developed in this research. Molecular dynamic (MD) simulation offered reasonable explanation of CNTs dispersion and their motion in polymer solution. Bi-mode finite-extensible-nonlinear-elastic (FENE) dumbbell simulation was used to analyze the influence of CNT length distribution on the stress tensor and shear-rate-dependent viscosity. Based on the simulated viscosity profile and empirical equations from experiments, a macroscale flow simulation model on the finite element method (FEM) method was developed and validated to predict resin flow behavior in the processing of CNT-enhanced multiscale composites. The proposed multiscale modeling method provided a comprehensive understanding of micro/nano flow in both atomistic details and mesoscale. The simulation model can be used to optimize process design and control of the mold-filling process in multiscale composite manufacturing. This research provided systematic investigations into the CNT-based multiscale composites. The results from this study may be used to leverage the benefits of CNTs and open up new application opportunities for high-performance multifunctional multiscale composites. Keywords. Carbon

  3. Solar and wind exergy potentials for Mars

    Delgado-Bonal, Alfonso; Martín-Torres, F. Javier; Vázquez-Martín, Sandra; Zorzano, María-Paz

    2016-01-01

    The energy requirements of the planetary exploration spacecrafts constrain the lifetime of the missions, their mobility and capabilities, and the number of instruments onboard. They are limiting factors in planetary exploration. Several missions to the surface of Mars have proven the feasibility and success of solar panels as energy source. The analysis of the exergy efficiency of the solar radiation has been carried out successfully on Earth, however, to date, there is not an extensive research regarding the thermodynamic exergy efficiency of in-situ renewable energy sources on Mars. In this paper, we analyse the obtainable energy (exergy) from solar radiation under Martian conditions. For this analysis we have used the surface environmental variables on Mars measured in-situ by the Rover Environmental Monitoring Station onboard the Curiosity rover and from satellite by the Thermal Emission Spectrometer instrument onboard the Mars Global Surveyor satellite mission. We evaluate the exergy efficiency from solar radiation on a global spatial scale using orbital data for a Martian year; and in a one single location in Mars (the Gale crater) but with an appreciable temporal resolution (1 h). Also, we analyse the wind energy as an alternative source of energy for Mars exploration and compare the results with those obtained on Earth. We study the viability of solar and wind energy station for the future exploration of Mars, showing that a small square solar cell of 0.30 m length could maintain a meteorological station on Mars. We conclude that the low density of the atmosphere of Mars is responsible of the low thermal exergy efficiency of solar panels. It also makes the use of wind energy uneffective. Finally, we provide insights for the development of new solar cells on Mars. - Highlights: • We analyse the exergy of solar radiation under Martian environment • Real data from in-situ instruments is used to determine the maximum efficiency of radiation • Wind

  4. The overprotection of Mars

    Fairén, Alberto G.; Schulze-Makuch, Dirk

    2013-07-01

    Planetary protection policies aim to guard Solar System bodies from biological contamination from spacecraft. Costly efforts to sterilize Mars spacecraft need to be re-evaluated, as they are unnecessarily inhibiting a more ambitious agenda to search for extant life on Mars.

  5. Building Virtual Mars

    Abercrombie, S. P.; Menzies, A.; Goddard, C.

    2017-12-01

    Virtual and augmented reality enable scientists to visualize environments that are very difficult, or even impossible to visit, such as the surface of Mars. A useful immersive visualization begins with a high quality reconstruction of the environment under study. This presentation will discuss a photogrammetry pipeline developed at the Jet Propulsion Laboratory to reconstruct 3D models of the surface of Mars using stereo images sent back to Earth by the Curiosity Mars rover. The resulting models are used to support a virtual reality tool (OnSight) that allows scientists and engineers to visualize the surface of Mars as if they were standing on the red planet. Images of Mars present challenges to existing scene reconstruction solutions. Surface images of Mars are sparse with minimal overlap, and are often taken from extremely different viewpoints. In addition, the specialized cameras used by Mars rovers are significantly different than consumer cameras, and GPS localization data is not available on Mars. This presentation will discuss scene reconstruction with an emphasis on coping with limited input data, and on creating models suitable for rendering in virtual reality at high frame rate.

  6. Microscope on Mars

    2004-01-01

    This image taken at Meridiani Planum, Mars by the panoramic camera on the Mars Exploration Rover Opportunity shows the rover's microscopic imager (circular device in center), located on its instrument deployment device, or 'arm.' The image was acquired on the ninth martian day or sol of the rover's mission.

  7. Mars Sample Handling Functionality

    Meyer, M. A.; Mattingly, R. L.

    2018-04-01

    The final leg of a Mars Sample Return campaign would be an entity that we have referred to as Mars Returned Sample Handling (MRSH.) This talk will address our current view of the functional requirements on MRSH, focused on the Sample Receiving Facility (SRF).

  8. IJslandse inzichten op Mars

    de Vet, S.

    2013-01-01

    Vulkaanuitbarstingen onder gletsjers, zoals de vliegverkeer-verlammende uitbarsting van de vulkaan Eyjafjallajökull in IJsland in 2010, lijken in veel opzichten op vulkaanuitbarstingen die ooit op Mars voorkwamen. Dankzij de landschappelijke gelijkenissen tussen onze aarde en Mars is het mogelijk om

  9. Low Energy Electrons in the Mars Plasma Environment

    Link, Richard

    2001-01-01

    The ionosphere of Mars is rather poorly understood. The only direct measurements were performed by the Viking 1 and 2 landers in 1976, both of which carried a Retarding Potential Analyzer. The RPA was designed to measure ion properties during the descent, although electron fluxes were estimated from changes in the ion currents. Using these derived low-energy electron fluxes, Mantas and Hanson studied the photoelectron and the solar wind electron interactions with the atmosphere and ionosphere of Mars. Unanswered questions remain regarding the origin of the low-energy electron fluxes in the vicinity of the Mars plasma boundary. Crider, in an analysis of Mars Global Surveyor Magnetometer/Electron Reflectometer measurements, has attributed the formation of the magnetic pile-up boundary to electron impact ionization of exospheric neutral species by solar wind electrons. However, the role of photoelectrons escaping from the lower ionosphere was not determined. In the proposed work, we will examine the role of solar wind and ionospheric photoelectrons in producing ionization in the upper ionosphere of Mars. Low-energy (internal (photoelectron) sources of ionization, and accounts for Auger electron production. The code will be used to analyze Mars Global Surveyor measurements of solar wind and photoelectrons down to altitudes below 200 km in the Mars ionosphere, in order to determine the relative roles of solar wind and escaping photoelectrons in maintaining plasma densities in the region of the Mars plasma boundary.

  10. Photogrammetric portrayal of Mars topography.

    Wu, S.S.C.

    1979-01-01

    Special photogrammetric techniques have been developed to portray Mars topography, using Mariner and Viking imaging and nonimaging topographic information and earth-based radar data. Topography is represented by the compilation of maps at three scales: global, intermediate, and very large scale. The global map is a synthesis of topographic information obtained from Mariner 9 and earth-based radar, compiled at a scale of 1:25,000,000 with a contour interval of 1 km; it gives a broad quantitative view of the planet. At intermediate scales, Viking Orbiter photographs of various resolutions are used to compile detailed contour maps of a broad spectrum of prominent geologic features; a contour interval as small as 20 m has been obtained from very high resolution orbital photography. Imagery from the Viking lander facsimile cameras permits construction of detailed, very large scale (1:10) topographic maps of the terrain surrounding the two landers; these maps have a contour interval of 1 cm. This paper presents several new detailed topographic maps of Mars.-Author

  11. Multiscale modelling in immunology: a review.

    Cappuccio, Antonio; Tieri, Paolo; Castiglione, Filippo

    2016-05-01

    One of the greatest challenges in biomedicine is to get a unified view of observations made from the molecular up to the organism scale. Towards this goal, multiscale models have been highly instrumental in contexts such as the cardiovascular field, angiogenesis, neurosciences and tumour biology. More recently, such models are becoming an increasingly important resource to address immunological questions as well. Systematic mining of the literature in multiscale modelling led us to identify three main fields of immunological applications: host-virus interactions, inflammatory diseases and their treatment and development of multiscale simulation platforms for immunological research and for educational purposes. Here, we review the current developments in these directions, which illustrate that multiscale models can consistently integrate immunological data generated at several scales, and can be used to describe and optimize therapeutic treatments of complex immune diseases. © The Author 2015. Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  12. Collaborating for Multi-Scale Chemical Science

    William H. Green

    2006-07-14

    Advanced model reduction methods were developed and integrated into the CMCS multiscale chemical science simulation software. The new technologies were used to simulate HCCI engines and burner flames with exceptional fidelity.

  13. Cancer Risk Map for the Surface of Mars

    Kim, Myung-Hee Y.; Cucinotta, Francis A.

    2011-01-01

    We discuss calculations of the median and 95th percentile cancer risks on the surface of Mars for different solar conditions. The NASA Space Radiation Cancer Risk 2010 model is used to estimate gender and age specific cancer incidence and mortality risks for astronauts exploring Mars. Organ specific fluence spectra and doses for large solar particle events (SPE) and galactic cosmic rays (GCR) at various levels of solar activity are simulated using the HZETRN/QMSFRG computer code, and the 2010 version of the Badhwar and O Neill GCR model. The NASA JSC propensity model of SPE fluence and occurrence is used to consider upper bounds on SPE fluence for increasing mission lengths. In the transport of particles through the Mars atmosphere, a vertical distribution of Mars atmospheric thickness is calculated from the temperature and pressure data of Mars Global Surveyor, and the directional cosine distribution is implemented to describe the spherically distributed atmospheric distance along the slant path at each elevation on Mars. The resultant directional shielding by Mars atmosphere at each elevation is coupled with vehicle and body shielding for organ dose estimates. Astronaut cancer risks are mapped on the global topography of Mars, which was measured by the Mars Orbiter Laser Altimeter. Variation of cancer risk on the surface of Mars is due to a 16-km elevation range, and the large difference is obtained between the Tharsis Montes (Ascraeus, Pavonis, and Arsia) and the Hellas impact basin. Cancer incidence risks are found to be about 2-fold higher than mortality risks with a disproportionate increase in skin and thyroid cancers for all astronauts and breast cancer risk for female astronauts. The number of safe days on Mars to be below radiation limits at the 95th percent confidence level is reported for several Mission design scenarios.

  14. Relay Telecommunications for the Coming Decade of Mars Exploration

    Edwards, C.; DePaula, R.

    2010-01-01

    Over the past decade, an evolving network of relay-equipped orbiters has advanced our capabilities for Mars exploration. NASA's Mars Global Surveyor, 2001 Mars Odyssey, and Mars Reconnaissance Orbiter (MRO), as well as ESA's Mars Express Orbiter, have provided telecommunications relay services to the 2003 Mars Exploration Rovers, Spirit and Opportunity, and to the 2007 Phoenix Lander. Based on these successes, a roadmap for continued Mars relay services is in place for the coming decade. MRO and Odyssey will provide key relay support to the 2011 Mars Science Laboratory (MSL) mission, including capture of critical event telemetry during entry, descent, and landing, as well as support for command and telemetry during surface operations, utilizing new capabilities of the Electra relay payload on MRO and the Electra-Lite payload on MSL to allow significant increase in data return relative to earlier missions. Over the remainder of the decade a number of additional orbiter and lander missions are planned, representing new orbital relay service providers and new landed relay users. In this paper we will outline this Mars relay roadmap, quantifying relay performance over time, illustrating planned support scenarios, and identifying key challenges and technology infusion opportunities.

  15. Multiscale Modeling of Wear Degradation

    Moraes, Alvaro; Ruggeri, Fabrizio; Tempone, Raul; Vilanova, Pedro

    2016-01-01

    Cylinder liners of diesel engines used for marine propulsion are naturally subjected to a wear process, and may fail when their wear exceeds a specified limit. Since failures often represent high economical costs, it is utterly important to predict and avoid them. In this work [4], we model the wear process using a pure jump process. Therefore, the inference goal here is to estimate: the number of possible jumps, its sizes, the coefficients and the shapes of the jump intensities. We propose a multiscale approach for the inference problem that can be seen as an indirect inference scheme. We found that using a Gaussian approximation based on moment expansions, it is possible to accurately estimate the jump intensities and the jump amplitudes. We obtained results equivalent to the state of the art but using a simpler and less expensive approach.

  16. Multiscale Modeling of Wear Degradation

    Moraes, Alvaro; Ruggeri, Fabrizio; Tempone, Raul; Vilanova, Pedro

    2015-01-01

    Cylinder liners of diesel engines used for marine propulsion are naturally subjected to a wear process, and may fail when their wear exceeds a specified limit. Since failures often represent high economical costs, it is utterly important to predict and avoid them. In this work [4], we model the wear process using a pure jump process. Therefore, the inference goal here is to estimate: the number of possible jumps, its sizes, the coefficients and the shapes of the jump intensities. We propose a multiscale approach for the inference problem that can be seen as an indirect inference scheme. We found that using a Gaussian approximation based on moment expansions, it is possible to accurately estimate the jump intensities and the jump amplitudes. We obtained results equivalent to the state of the art but using a simpler and less expensive approach.

  17. Multiscale Modeling of Wear Degradation

    Moraes, Alvaro

    2015-01-07

    Cylinder liners of diesel engines used for marine propulsion are naturally subjected to a wear process, and may fail when their wear exceeds a specified limit. Since failures often represent high economical costs, it is utterly important to predict and avoid them. In this work [4], we model the wear process using a pure jump process. Therefore, the inference goal here is to estimate: the number of possible jumps, its sizes, the coefficients and the shapes of the jump intensities. We propose a multiscale approach for the inference problem that can be seen as an indirect inference scheme. We found that using a Gaussian approximation based on moment expansions, it is possible to accurately estimate the jump intensities and the jump amplitudes. We obtained results equivalent to the state of the art but using a simpler and less expensive approach.

  18. Multiscale Modeling of Wear Degradation

    Moraes, Alvaro

    2014-01-06

    Cylinder liners of diesel engines used for marine propulsion are naturally subjected to a wear process, and may fail when their wear exceeds a specified limit. Since failures often represent high economical costs, it is utterly important to predict and avoid them. In this work [4], we model the wear process using a pure jump process. Therefore, the inference goal here is to estimate: the number of possible jumps, its sizes, the coefficients and the shapes of the jump intensities. We propose a multiscale approach for the inference problem that can be seen as an indirect inference scheme. We found that using a Gaussian approximation based on moment expansions, it is possible to accurately estimate the jump intensities and the jump amplitudes. We obtained results equivalent to the state of the art but using a simpler and less expensive approach.

  19. Multiscale Modeling of Wear Degradation

    Moraes, Alvaro

    2016-01-06

    Cylinder liners of diesel engines used for marine propulsion are naturally subjected to a wear process, and may fail when their wear exceeds a specified limit. Since failures often represent high economical costs, it is utterly important to predict and avoid them. In this work [4], we model the wear process using a pure jump process. Therefore, the inference goal here is to estimate: the number of possible jumps, its sizes, the coefficients and the shapes of the jump intensities. We propose a multiscale approach for the inference problem that can be seen as an indirect inference scheme. We found that using a Gaussian approximation based on moment expansions, it is possible to accurately estimate the jump intensities and the jump amplitudes. We obtained results equivalent to the state of the art but using a simpler and less expensive approach.

  20. Wavelets and multiscale signal processing

    Cohen, Albert

    1995-01-01

    Since their appearance in mid-1980s, wavelets and, more generally, multiscale methods have become powerful tools in mathematical analysis and in applications to numerical analysis and signal processing. This book is based on "Ondelettes et Traitement Numerique du Signal" by Albert Cohen. It has been translated from French by Robert D. Ryan and extensively updated by both Cohen and Ryan. It studies the existing relations between filter banks and wavelet decompositions and shows how these relations can be exploited in the context of digital signal processing. Throughout, the book concentrates on the fundamentals. It begins with a chapter on the concept of multiresolution analysis, which contains complete proofs of the basic results. The description of filter banks that are related to wavelet bases is elaborated in both the orthogonal case (Chapter 2), and in the biorthogonal case (Chapter 4). The regularity of wavelets, how this is related to the properties of the filters and the importance of regularity for t...

  1. Multiphysics/multiscale multifluid computations

    Yadigaroglu, George

    2014-01-01

    Regarding experimentation, interesting examples of multi-scale approaches are found: the small-scale experiments to understand the mechanisms of counter-current flow limitations (CCFL) such as the growth of instabilities on films, droplet entrainment, etc; meso-scale experiments to quantify the CCFL conditions in typical geometries such as tubes and gaps between parallel plates, and finally full-scale experimentation in a typical reactor geometry - the UPTF tests. Another example is the mixing of the atmosphere produced by plumes and jets in a reactor containment: one needs first basic turbulence information that can be obtained at the microscopic level; follow medium-scale experiments to understand the behaviour of jets and plumes; finally reactor-scale tests can be conducted in facilities such as PANDA at PSI, in Switzerland to study the phenomena at large scale

  2. Multiscale modeling of pedestrian dynamics

    Cristiani, Emiliano; Tosin, Andrea

    2014-01-01

    This book presents mathematical models and numerical simulations of crowd dynamics. The core topic is the development of a new multiscale paradigm, which bridges the microscopic and macroscopic scales taking the most from each of them for capturing the relevant clues of complexity of crowds. The background idea is indeed that most of the complex trends exhibited by crowds are due to an intrinsic interplay between individual and collective behaviors. The modeling approach promoted in this book pursues actively this intuition and profits from it for designing general mathematical structures susceptible of application also in fields different from the inspiring original one. The book considers also the two most traditional points of view: the microscopic one, in which pedestrians are tracked individually, and the macroscopic one, in which pedestrians are assimilated to a continuum. Selected existing models are critically analyzed. The work is addressed to researchers and graduate students.

  3. SGTR assessment using MARS

    Raines, J.C.; Dawson, S.M.; Deitke, B.; Henry, R.E.

    1996-01-01

    During the course of a plant accident, a consistent understanding of the plant response is vital to support an accident manager's decision making process. One tool that can provide assistance to the plant staff in assessing conditions in the plant during accident conditions is the MAAP Accident Response System (MARS) software. During an accident, MARS utilizes the on-line data from the plant instrumentation to initialize the Modular Accident Analysis Program (MAAP) code. Once initialized, MARS tracks and characterizes the plant behavior through the use of integrated logic modules. These logic modules provide the user with important information about the status of systems and the possible cause of the accident. The MARS logic modules evaluate relevant available plant instrumentation and the observations of the operating staff using fuzzy logic. The fuzzy logic is applied to provide a transition between areas where one is absolutely sure that a situation has not occurred to a condition where one is absolutely certain that a situation has occurred. One example of the use of logic modules in MARS is illustrated by that used to assess if a steam generator tube rupture (SGTR) event has occurred. Each piece of relevant plant data is evaluated to determine if it is consistent with the symptoms of a SGTR. Each of the evaluations for the individual plant instruments and the operating staff observations are assembled to determine an overall confidence which characterizes the likelihood that a SGTR is occurring. Additional MARS logic modules are used to determine confidence levels for other types of accident events. The conclusions arrived at by each individual logic module are expressed as confidence levels. The logic module confidence levels can be graphically displayed using the MARS Graphical Users Interface (GUI), to indicate the confidence level MARS has assessed for each accident type. The GUI shows the identification of the possible accident types, but is not limited

  4. Generalized multiscale finite element methods. nonlinear elliptic equations

    Efendiev, Yalchin R.; Galvis, Juan; Li, Guanglian; Presho, Michael

    2013-01-01

    In this paper we use the Generalized Multiscale Finite Element Method (GMsFEM) framework, introduced in [26], in order to solve nonlinear elliptic equations with high-contrast coefficients. The proposed solution method involves linearizing the equation so that coarse-grid quantities of previous solution iterates can be regarded as auxiliary parameters within the problem formulation. With this convention, we systematically construct respective coarse solution spaces that lend themselves to either continuous Galerkin (CG) or discontinuous Galerkin (DG) global formulations. Here, we use Symmetric Interior Penalty Discontinuous Galerkin approach. Both methods yield a predictable error decline that depends on the respective coarse space dimension, and we illustrate the effectiveness of the CG and DG formulations by offering a variety of numerical examples. © 2014 Global-Science Press.

  5. Modeling the hydrological cycle on Mars

    Ghada Machtoub

    2012-03-01

    Full Text Available The study provides a detailed analysis of the hydrological cycle on Mars simulated with a newly developed microphysical model, incorporated in a spectral Mars General Circulation Model. The modeled hydrological cycle is compared well with simulations of other global climate models. The simulated seasonal migration ofwater vapor, circulation instability, and the high degree of temporal variability of localized water vapor outbursts are shown closely consistent with recent observations. The microphysical parameterization provides a significant improvement in the modeling of ice clouds evolved over the tropics and major ancient volcanoes on Mars. The most significant difference between the simulations presented here and other GCM results is the level at which the water ice clouds are found. The model findings also support interpretation of observed thermal anomalies in the Martian tropics during northern spring and summer seasons.

  6. Integrated multi-scale modelling and simulation of nuclear fuels

    Valot, C.; Bertolus, M.; Masson, R.; Malerba, L.; Rachid, J.; Besmann, T.; Phillpot, S.; Stan, M.

    2015-01-01

    This chapter aims at discussing the objectives, implementation and integration of multi-scale modelling approaches applied to nuclear fuel materials. We will first show why the multi-scale modelling approach is required, due to the nature of the materials and by the phenomena involved under irradiation. We will then present the multiple facets of multi-scale modelling approach, while giving some recommendations with regard to its application. We will also show that multi-scale modelling must be coupled with appropriate multi-scale experiments and characterisation. Finally, we will demonstrate how multi-scale modelling can contribute to solving technology issues. (authors)

  7. A concurrent multiscale micromorphic molecular dynamics

    Li, Shaofan; Tong, Qi

    2015-01-01

    In this work, we have derived a multiscale micromorphic molecular dynamics (MMMD) from first principle to extend the (Andersen)-Parrinello-Rahman molecular dynamics to mesoscale and continuum scale. The multiscale micromorphic molecular dynamics is a con-current three-scale dynamics that couples a fine scale molecular dynamics, a mesoscale micromorphic dynamics, and a macroscale nonlocal particle dynamics together. By choosing proper statistical closure conditions, we have shown that the original Andersen-Parrinello-Rahman molecular dynamics is the homogeneous and equilibrium case of the proposed multiscale micromorphic molecular dynamics. In specific, we have shown that the Andersen-Parrinello-Rahman molecular dynamics can be rigorously formulated and justified from first principle, and its general inhomogeneous case, i.e., the three scale con-current multiscale micromorphic molecular dynamics can take into account of macroscale continuum mechanics boundary condition without the limitation of atomistic boundary condition or periodic boundary conditions. The discovered multiscale scale structure and the corresponding multiscale dynamics reveal a seamless transition from atomistic scale to continuum scale and the intrinsic coupling mechanism among them based on first principle formulation

  8. Fast Multiscale Reservoir Simulations using POD-DEIM Model Reduction

    Ghasemi, Mohammadreza

    2015-02-23

    In this paper, we present a global-local model reduction for fast multiscale reservoir simulations in highly heterogeneous porous media with applications to optimization and history matching. Our proposed approach identifies a low dimensional structure of the solution space. We introduce an auxiliary variable (the velocity field) in our model reduction that allows achieving a high degree of model reduction. The latter is due to the fact that the velocity field is conservative for any low-order reduced model in our framework. Because a typical global model reduction based on POD is a Galerkin finite element method, and thus it can not guarantee local mass conservation. This can be observed in numerical simulations that use finite volume based approaches. Discrete Empirical Interpolation Method (DEIM) is used to approximate the nonlinear functions of fine-grid functions in Newton iterations. This approach allows achieving the computational cost that is independent of the fine grid dimension. POD snapshots are inexpensively computed using local model reduction techniques based on Generalized Multiscale Finite Element Method (GMsFEM) which provides (1) a hierarchical approximation of snapshot vectors (2) adaptive computations by using coarse grids (3) inexpensive global POD operations in a small dimensional spaces on a coarse grid. By balancing the errors of the global and local reduced-order models, our new methodology can provide an error bound in simulations. Our numerical results, utilizing a two-phase immiscible flow, show a substantial speed-up and we compare our results to the standard POD-DEIM in finite volume setup.

  9. Thermal inertia and surface heterogeneity on Mars

    Putzig, Nathaniel E.

    Thermal inertia derived from temperature observations is critical for understanding surface geology and assessing potential landing sites on Mars. Derivation methods generally assume uniform surface properties for any given observation. Consequently, horizontal heterogeneity and near-surface layering may yield apparent thermal inertia that varies with time of day and season. To evaluate the effects of horizontal heterogeneity, I modeled the thermal behavior of surfaces containing idealized material mixtures (dust, sand, duricrust, and rocks) and differing slope facets. These surfaces exhibit diurnal and seasonal variability in apparent thermal inertia of several 100 tiu, 1 even for components with moderately contrasting thermal properties. To isolate surface effects on the derived thermal inertia of Mars, I mapped inter- annual and seasonal changes in albedo and atmospheric dust opacity, accounting for their effects in a modified derivation algorithm. Global analysis of three Mars years of MGS-TES 2 data reveals diurnal and seasonal variations of ~200 tiu in the mid-latitudes and 600 tiu or greater in the polar regions. Correlation of TES results and modeled apparent thermal inertia of heterogeneous surfaces indicates pervasive surface heterogeneity on Mars. At TES resolution, the near-surface thermal response is broadly dominated by layering and is consistent with the presence of duricrusts over fines in the mid-latitudes and dry soils over ground ice in the polar regions. Horizontal surface mixtures also play a role and may dominate at higher resolution. In general, thermal inertia obtained from single observations or annually averaged maps may misrepresent surface properties. In lieu of a robust heterogeneous- surface derivation technique, repeat coverage can be used together with forward-modeling results to constrain the near-surface heterogeneity of Mars. 1 tiu == J m -2 K -1 s - 2 Mars Global Surveyor Thermal Emission Spectrometer

  10. Multiscale Model Reduction with Generalized Multiscale Finite Element Methods in Geomathematics

    Efendiev, Yalchin R.; Presho, Michael

    2015-01-01

    In this chapter, we discuss multiscale model reduction using Generalized Multiscale Finite Element Methods (GMsFEM) in a number of geomathematical applications. GMsFEM has been recently introduced (Efendiev et al. 2012) and applied to various problems. In the current chapter, we consider some of these applications and outline the basic methodological concepts.

  11. Distributed multiscale computing with MUSCLE 2, the Multiscale Coupling Library and Environment

    Borgdorff, J.; Mamonski, M.; Bosak, B.; Kurowski, K.; Ben Belgacem, M.; Chopard, B.; Groen, D.; Coveney, P.V.; Hoekstra, A.G.

    2014-01-01

    We present the Multiscale Coupling Library and Environment: MUSCLE 2. This multiscale component-based execution environment has a simple to use Java, C++, C, Python and Fortran API, compatible with MPI, OpenMP and threading codes. We demonstrate its local and distributed computing capabilities and

  12. A distributed multiscale computation of a tightly coupled model using the Multiscale Modeling Language

    Borgdorff, J.; Bona-Casas, C.; Mamonski, M.; Kurowski, K.; Piontek, T.; Bosak, B.; Rycerz, K.; Ciepiela, E.; Gubala, T.; Harezlak, D.; Bubak, M.; Lorenz, E.; Hoekstra, A.G.

    2012-01-01

    Nature is observed at all scales; with multiscale modeling, scientists bring together several scales for a holistic analysis of a phenomenon. The models on these different scales may require significant but also heterogeneous computational resources, creating the need for distributed multiscale

  13. Multiscale Model Reduction with Generalized Multiscale Finite Element Methods in Geomathematics

    Efendiev, Yalchin R.

    2015-09-02

    In this chapter, we discuss multiscale model reduction using Generalized Multiscale Finite Element Methods (GMsFEM) in a number of geomathematical applications. GMsFEM has been recently introduced (Efendiev et al. 2012) and applied to various problems. In the current chapter, we consider some of these applications and outline the basic methodological concepts.

  14. Revised coordinates of the Mars Orbiter Laser Altimeter (MOLA) footprints

    Annibali, S.; Stark, A.; Gwinner, K.; Hussmann, H.; Oberst, J.

    2017-09-01

    We revised the Mars Orbiter Laser Altimeter (MOLA) footprint locations (i.e. areocentric body-fixed latitude and longitude), using updated trajectory models for the Mars Global Surveyor and updated rotation parameters of Mars, including precession, nutation and length-of-day variation. We assess the impact of these updates on the gridded MOLA maps. A first comparison reveals that even slight corrections to the rotational state of Mars can lead to height differences up to 100 m (in particular in regions with high slopes, where large interpolation effects are expected). Ultimately, we aim at independent measurements of the rotation parameters of Mars. We co-register MOLA profiles to digital terrain models from stereo images (stereo DTMs) and measure offsets of the two data sets.

  15. Mars Technology Project

    National Aeronautics and Space Administration — NASA’s Mars Exploration Program (MEP) calls for a series of highly ambitious missions over the next decade and beyond. The overall goals of the MEP must be...

  16. Mars Electric Reusable Flyer

    National Aeronautics and Space Administration — One of the main issues with a Mars flight vehicle concept that can be reused and cover long distances for maximum surface data gathering is its ability to take off,...

  17. Environment of Mars, 1988

    Kaplan, D.I.

    1988-10-01

    A compilation of scientific knowledge about the planet Mars is provided. Information is divided into three categories: atmospheric data, surface data, and astrodynamic data. The discussion of atmospheric data includes the presentation of nine different models of the Mars atmosphere. Also discussed are Martian atmospheric constituents, winds, clouds, and solar irradiance. The great dust storms of Mars are presented. The section on Mars surface data provides an in-depth examination of the physical and chemical properties observed at the two Viking landing sites. Bulk densities, dielectric constants, and thermal inertias across the planet are then described and related back to those specific features found at the Viking landing sites. The astrodynamic materials provide the astronomical constants, time scales, and reference coordinate frames necessary to perform flightpath analysis, navigation design, and science observation design

  18. MARS software package status

    Azhgirej, I.L.; Talanov, V.V.

    2000-01-01

    The MARS software package is intended for simulating the nuclear-electromagnetic cascades and the secondary neutrons and muons transport in the heterogeneous medium of arbitrary complexity in the magnetic fields presence. The inclusive approach to describing the particle production in the nuclear and electromagnetic interactions and by the unstable particles decay is realized in the package. The MARS software package was actively applied for solving various radiation physical problems [ru

  19. Status of MARS Code

    N.V. Mokhov

    2003-04-09

    Status and recent developments of the MARS 14 Monte Carlo code system for simulation of hadronic and electromagnetic cascades in shielding, accelerator and detector components in the energy range from a fraction of an electronvolt up to 100 TeV are described. these include physics models both in strong and electromagnetic interaction sectors, variance reduction techniques, residual dose, geometry, tracking, histograming. MAD-MARS Beam Line Build and Graphical-User Interface.

  20. Terrestrial Analogs to Mars

    Farr, T. G.; Arcone, S.; Arvidson, R. W.; Baker, V.; Barlow, N. G.; Beaty, D.; Bell, M. S.; Blankenship, D. D.; Bridges, N.; Briggs, G.; Bulmer, M.; Carsey, F.; Clifford, S. M.; Craddock, R. A.; Dickerson, P. W.; Duxbury, N.; Galford, G. L.; Garvin, J.; Grant, J.; Green, J. R.; Gregg, T. K. P.; Guinness, E.; Hansen, V. L.; Hecht, M. H.; Holt, J.; Howard, A.; Keszthelyi, L. P.; Lee, P.; Lanagan, P. D.; Lentz, R. C. F.; Leverington, D. W.; Marinangeli, L.; Moersch, J. E.; Morris-Smith, P. A.; Mouginis-Mark, P.; Olhoeft, G. R.; Ori, G. G.; Paillou, P.; Reilly, J. F., II; Rice, J. W., Jr.; Robinson, C. A.; Sheridan, M.; Snook, K.; Thomson, B. J.; Watson, K.; Williams, K.; Yoshikawa, K.

    2002-08-01

    It is well recognized that interpretations of Mars must begin with the Earth as a reference. The most successful comparisons have focused on understanding geologic processes on the Earth well enough to extrapolate to Mars' environment. Several facets of terrestrial analog studies have been pursued and are continuing. These studies include field workshops, characterization of terrestrial analog sites, instrument tests, laboratory measurements (including analysis of Martian meteorites), and computer and laboratory modeling. The combination of all these activities allows scientists to constrain the processes operating in specific terrestrial environments and extrapolate how similar processes could affect Mars. The Terrestrial Analogs for Mars Community Panel has considered the following two key questions: (1) How do terrestrial analog studies tie in to the Mars Exploration Payload Assessment Group science questions about life, past climate, and geologic evolution of Mars, and (2) How can future instrumentation be used to address these questions. The panel has considered the issues of data collection, value of field workshops, data archiving, laboratory measurements and modeling, human exploration issues, association with other areas of solar system exploration, and education and public outreach activities.

  1. Life on Mars

    McKay, Christopher P.; Cuzzi, Jeffrey (Technical Monitor)

    1996-01-01

    Although the Viking results may indicate that Mars has no life today, the possibility exists that Mars may hold the best record of the events that led to the origin of life. There is direct geomorphological evidence that in the past Mars had large amounts of liquid water on its surface. Atmospheric models would suggest that this early period of hydrological activity was due to the presence of a thick atmosphere and the resulting warmer temperatures. From a biological perspective the existence of liquid water, by itself motivates the question of the origin of life on Mars. From studies of the Earth's earliest biosphere we know that by 3.5 Gyr. ago, life had originated on Earth and reached a fair degree of biological sophistication. Surface activity and erosion on Earth make it difficult to trace the history of life before the 3.5 Gyr timeframe. If Mars did maintain a clement environment for longer than it took for life to originate on Earth, then the question of the origin of life on Mars follows naturally.

  2. Novel Multiscale Modeling Tool Applied to Pseudomonas aeruginosa Biofilm Formation

    Biggs, Matthew B.; Papin, Jason A.

    2013-01-01

    Multiscale modeling is used to represent biological systems with increasing frequency and success. Multiscale models are often hybrids of different modeling frameworks and programming languages. We present the MATLAB-NetLogo extension (MatNet) as a novel tool for multiscale modeling. We demonstrate the utility of the tool with a multiscale model of Pseudomonas aeruginosa biofilm formation that incorporates both an agent-based model (ABM) and constraint-based metabolic modeling. The hybrid mod...

  3. Multiscale study of metal nanoparticles

    Lee, Byeongchan

    Extremely small structures with reduced dimensionality have emerged as a scientific motif for their interesting properties. In particular, metal nanoparticles have been identified as a fundamental material in many catalytic activities; as a consequence, a better understanding of structure-function relationship of nanoparticles has become crucial. The functional analysis of nanoparticles, reactivity for example, requires an accurate method at the electronic structure level, whereas the structural analysis to find energetically stable local minima is beyond the scope of quantum mechanical methods as the computational cost becomes prohibitingly high. The challenge is that the inherent length scale and accuracy associated with any single method hardly covers the broad scale range spanned by both structural and functional analyses. In order to address this, and effectively explore the energetics and reactivity of metal nanoparticles, a hierarchical multiscale modeling is developed, where methodologies of different length scales, i.e. first principles density functional theory, atomistic calculations, and continuum modeling, are utilized in a sequential fashion. This work has focused on identifying the essential information that bridges two different methods so that a successive use of different methods is seamless. The bond characteristics of low coordination systems have been obtained with first principles calculations, and incorporated into the atomistic simulation. This also rectifies the deficiency of conventional interatomic potentials fitted to bulk properties, and improves the accuracy of atomistic calculations for nanoparticles. For the systematic shape selection of nanoparticles, we have improved the Wulff-type construction using a semi-continuum approach, in which atomistic surface energetics and crystallinity of materials are added on to the continuum framework. The developed multiscale modeling scheme is applied to the rational design of platinum

  4. Cloud Detection by Fusing Multi-Scale Convolutional Features

    Li, Zhiwei; Shen, Huanfeng; Wei, Yancong; Cheng, Qing; Yuan, Qiangqiang

    2018-04-01

    Clouds detection is an important pre-processing step for accurate application of optical satellite imagery. Recent studies indicate that deep learning achieves best performance in image segmentation tasks. Aiming at boosting the accuracy of cloud detection for multispectral imagery, especially for those that contain only visible and near infrared bands, in this paper, we proposed a deep learning based cloud detection method termed MSCN (multi-scale cloud net), which segments cloud by fusing multi-scale convolutional features. MSCN was trained on a global cloud cover validation collection, and was tested in more than ten types of optical images with different resolution. Experiment results show that MSCN has obvious advantages over the traditional multi-feature combined cloud detection method in accuracy, especially when in snow and other areas covered by bright non-cloud objects. Besides, MSCN produced more detailed cloud masks than the compared deep cloud detection convolution network. The effectiveness of MSCN make it promising for practical application in multiple kinds of optical imagery.

  5. Multiscale spatial and temporal estimation of the b-value

    García-Hernández, R.; D'Auria, L.; Barrancos, J.; Padilla, G.

    2017-12-01

    The estimation of the spatial and temporal variations of the Gutenberg-Richter b-value is of great importance in different seismological applications. One of the problems affecting its estimation is the heterogeneous distribution of the seismicity which makes its estimate strongly dependent upon the selected spatial and/or temporal scale. This is especially important in volcanoes where dense clusters of earthquakes often overlap the background seismicity. Proposed solutions for estimating temporal variations of the b-value include considering equally spaced time intervals or variable intervals having an equal number of earthquakes. Similar approaches have been proposed to image the spatial variations of this parameter as well.We propose a novel multiscale approach, based on the method of Ogata and Katsura (1993), allowing a consistent estimation of the b-value regardless of the considered spatial and/or temporal scales. Our method, named MUST-B (MUltiscale Spatial and Temporal characterization of the B-value), basically consists in computing estimates of the b-value at multiple temporal and spatial scales, extracting for a give spatio-temporal point a statistical estimator of the value, as well as and indication of the characteristic spatio-temporal scale. This approach includes also a consistent estimation of the completeness magnitude (Mc) and of the uncertainties over both b and Mc.We applied this method to example datasets for volcanic (Tenerife, El Hierro) and tectonic areas (Central Italy) as well as an example application at global scale.

  6. Multiscale CNNs for Brain Tumor Segmentation and Diagnosis

    Liya Zhao

    2016-01-01

    Full Text Available Early brain tumor detection and diagnosis are critical to clinics. Thus segmentation of focused tumor area needs to be accurate, efficient, and robust. In this paper, we propose an automatic brain tumor segmentation method based on Convolutional Neural Networks (CNNs. Traditional CNNs focus only on local features and ignore global region features, which are both important for pixel classification and recognition. Besides, brain tumor can appear in any place of the brain and be any size and shape in patients. We design a three-stream framework named as multiscale CNNs which could automatically detect the optimum top-three scales of the image sizes and combine information from different scales of the regions around that pixel. Datasets provided by Multimodal Brain Tumor Image Segmentation Benchmark (BRATS organized by MICCAI 2013 are utilized for both training and testing. The designed multiscale CNNs framework also combines multimodal features from T1, T1-enhanced, T2, and FLAIR MRI images. By comparison with traditional CNNs and the best two methods in BRATS 2012 and 2013, our framework shows advances in brain tumor segmentation accuracy and robustness.

  7. Multiscale CNNs for Brain Tumor Segmentation and Diagnosis.

    Zhao, Liya; Jia, Kebin

    2016-01-01

    Early brain tumor detection and diagnosis are critical to clinics. Thus segmentation of focused tumor area needs to be accurate, efficient, and robust. In this paper, we propose an automatic brain tumor segmentation method based on Convolutional Neural Networks (CNNs). Traditional CNNs focus only on local features and ignore global region features, which are both important for pixel classification and recognition. Besides, brain tumor can appear in any place of the brain and be any size and shape in patients. We design a three-stream framework named as multiscale CNNs which could automatically detect the optimum top-three scales of the image sizes and combine information from different scales of the regions around that pixel. Datasets provided by Multimodal Brain Tumor Image Segmentation Benchmark (BRATS) organized by MICCAI 2013 are utilized for both training and testing. The designed multiscale CNNs framework also combines multimodal features from T1, T1-enhanced, T2, and FLAIR MRI images. By comparison with traditional CNNs and the best two methods in BRATS 2012 and 2013, our framework shows advances in brain tumor segmentation accuracy and robustness.

  8. The MARS2013 Mars analog mission.

    Groemer, Gernot; Soucek, Alexander; Frischauf, Norbert; Stumptner, Willibald; Ragonig, Christoph; Sams, Sebastian; Bartenstein, Thomas; Häuplik-Meusburger, Sandra; Petrova, Polina; Evetts, Simon; Sivenesan, Chan; Bothe, Claudia; Boyd, Andrea; Dinkelaker, Aline; Dissertori, Markus; Fasching, David; Fischer, Monika; Föger, Daniel; Foresta, Luca; Fritsch, Lukas; Fuchs, Harald; Gautsch, Christoph; Gerard, Stephan; Goetzloff, Linda; Gołebiowska, Izabella; Gorur, Paavan; Groemer, Gerhard; Groll, Petra; Haider, Christian; Haider, Olivia; Hauth, Eva; Hauth, Stefan; Hettrich, Sebastian; Jais, Wolfgang; Jones, Natalie; Taj-Eddine, Kamal; Karl, Alexander; Kauerhoff, Tilo; Khan, Muhammad Shadab; Kjeldsen, Andreas; Klauck, Jan; Losiak, Anna; Luger, Markus; Luger, Thomas; Luger, Ulrich; McArthur, Jane; Moser, Linda; Neuner, Julia; Orgel, Csilla; Ori, Gian Gabriele; Paternesi, Roberta; Peschier, Jarno; Pfeil, Isabella; Prock, Silvia; Radinger, Josef; Ramirez, Barbara; Ramo, Wissam; Rampey, Mike; Sams, Arnold; Sams, Elisabeth; Sandu, Oana; Sans, Alejandra; Sansone, Petra; Scheer, Daniela; Schildhammer, Daniel; Scornet, Quentin; Sejkora, Nina; Stadler, Andrea; Stummer, Florian; Taraba, Michael; Tlustos, Reinhard; Toferer, Ernst; Turetschek, Thomas; Winter, Egon; Zanella-Kux, Katja

    2014-05-01

    We report on the MARS2013 mission, a 4-week Mars analog field test in the northern Sahara. Nineteen experiments were conducted by a field crew in Morocco under simulated martian surface exploration conditions, supervised by a Mission Support Center in Innsbruck, Austria. A Remote Science Support team analyzed field data in near real time, providing planning input for the management of a complex system of field assets; two advanced space suit simulators, four robotic vehicles, an emergency shelter, and a stationary sensor platform in a realistic work flow were coordinated by a Flight Control Team. A dedicated flight planning group, external control centers for rover tele-operations, and a biomedical monitoring team supported the field operations. A 10 min satellite communication delay and other limitations pertinent to human planetary surface activities were introduced. The fields of research for the experiments were geology, human factors, astrobiology, robotics, tele-science, exploration, and operations research. This paper provides an overview of the geological context and environmental conditions of the test site and the mission architecture, in particular the communication infrastructure emulating the signal travel time between Earth and Mars. We report on the operational work flows and the experiments conducted, including a deployable shelter prototype for multiple-day extravehicular activities and contingency situations.

  9. Implementing a Science-driven Mars Exploration Program

    Garvin, J. B.

    2001-12-01

    NASA's newly restructured Mars Exploration Program (MEP) was developed on the basis of the goals, objectives, investigations, and prioritizations established by the Mars Exploration Payload Analysis Group (as summarized previously by Greeley et al., 2001). The underlying scientific strategy is linked to common threads which include the many roles water has played on and within Mars as a "system". The implementation strategy that has been adopted relies heavily on an ever-sharpening program of reconnaissance, beginning with the legacy of the Mars Global Surveyor, continuing with the multispectral and compositional observations of the Mars Odyssey orbiter, and extending to a first step in surface-based reconnaissance with the 2003 Mars Exploration Rovers. The results of MGS and Odyssey will serve to focus the trade space of localities where the record, for example, of persistent surface water may have been preserved in a mineralogical sense. The 2005 Mars Reconnaissance Orbiter will further downselect the subset of sites on Mars where evidence of depositional patterns and aqueous mineralogies (i.e., diagenetic minerals) are most striking at scales as fine as tens to hundreds of meters. Reconnaissance will move to the surface and shallow subsurface in 2007 with the Mars "Smart Lander" (MSL), at which time an extensive array of mobile scientific exploration tools will be used to examine a locality at 10km traverse scales, ultimately asking scientific questions which can be classed as paleobiological (i.e., life inference). Further orbital reconnaissance may be undertaken in 2009, perhaps involving targeted multi-wavelength SAR imaging, in anticipation of a precisely targeted Mars Sample Return mission as early as 2011. This sequence of core program MEP missions will be amplified by the selection of PI-led SCOUT missions, starting in 2007, and continuing every other Mars launch opportunity.

  10. Examining Mars with SPICE

    Acton, Charles H.; Bachman, Nathaniel J.; Bytof, Jeff A.; Semenov, Boris V.; Taber, William; Turner, F. Scott; Wright, Edward D.

    1999-01-01

    The International Mars Conference highlights the wealth of scientific data now and soon to be acquired from an international armada of Mars-bound robotic spacecraft. Underlying the planning and interpretation of these scientific observations around and upon Mars are ancillary data and associated software needed to deal with trajectories or locations, instrument pointing, timing and Mars cartographic models. The NASA planetary community has adopted the SPICE system of ancillary data standards and allied tools to fill the need for consistent, reliable access to these basic data and a near limitless range of derived parameters. After substantial rapid growth in its formative years, the SPICE system continues to evolve today to meet new needs and improve ease of use. Adaptations to handle landers and rovers were prototyped on the Mars pathfinder mission and will next be used on Mars '01-'05. Incorporation of new methods to readily handle non-inertial reference frames has vastly extended the capability and simplified many computations. A translation of the SPICE Toolkit software suite to the C language has just been announced. To further support cartographic calculations associated with Mars exploration the SPICE developers at JPL have recently been asked by NASA to work with cartographers to develop standards and allied software for storing and accessing control net and shape model data sets; these will be highly integrated with existing SPICE components. NASA specifically supports the widest possible utilization of SPICE capabilities throughout the international space science community. With NASA backing the Russian Space Agency and Russian Academy of Science adopted the SPICE standards for the Mars 96 mission. The SPICE ephemeris component will shortly become the international standard for agencies using the Deep Space Network. U.S. and European scientists hope that ESA will employ SPICE standards on the Mars Express mission. SPICE is an open set of standards, and

  11. Macrosystems ecology: novel methods and new understanding of multi-scale patterns and processes

    Songlin Fei; Qinfeng Guo; Kevin Potter

    2016-01-01

    As the global biomes are increasingly threatened by human activities, understanding of macroscale patterns and processes is pressingly needed for effective management and policy making. Macrosystems ecology, which studies multiscale ecologicalpatterns and processes, has gained growing interest in the research community. However, as a relatively new field in...

  12. 3D deblending of simultaneous source data based on 3D multi-scale shaping operator

    Zu, Shaohuan; Zhou, Hui; Mao, Weijian; Gong, Fei; Huang, Weilin

    2018-04-01

    We propose an iterative three-dimensional (3D) deblending scheme using 3D multi-scale shaping operator to separate 3D simultaneous source data. The proposed scheme is based on the property that signal is coherent, whereas interference is incoherent in some domains, e.g., common receiver domain and common midpoint domain. In two-dimensional (2D) blended record, the coherency difference of signal and interference is in only one spatial direction. Compared with 2D deblending, the 3D deblending can take more sparse constraints into consideration to obtain better performance, e.g., in 3D common receiver gather, the coherency difference is in two spatial directions. Furthermore, with different levels of coherency, signal and interference distribute in different scale curvelet domains. In both 2D and 3D blended records, most coherent signal locates in coarse scale curvelet domain, while most incoherent interference distributes in fine scale curvelet domain. The scale difference is larger in 3D deblending, thus, we apply the multi-scale shaping scheme to further improve the 3D deblending performance. We evaluate the performance of 3D and 2D deblending with the multi-scale and global shaping operators, respectively. One synthetic and one field data examples demonstrate the advantage of the 3D deblending with 3D multi-scale shaping operator.

  13. Expanded Mixed Multiscale Finite Element Methods and Their Applications for Flows in Porous Media

    Jiang, L.

    2012-01-01

    We develop a family of expanded mixed multiscale finite element methods (MsFEMs) and their hybridizations for second-order elliptic equations. This formulation expands the standard mixed multiscale finite element formulation in the sense that four unknowns (hybrid formulation) are solved simultaneously: pressure, gradient of pressure, velocity, and Lagrange multipliers. We use multiscale basis functions for both the velocity and the gradient of pressure. In the expanded mixed MsFEM framework, we consider both separable and nonseparable spatial scales. Specifically, we analyze the methods in three categories: periodic separable scales, G-convergent separable scales, and a continuum of scales. When there is no scale separation, using some global information can significantly improve the accuracy of the expanded mixed MsFEMs. We present a rigorous convergence analysis of these methods that includes both conforming and nonconforming formulations. Numerical results are presented for various multiscale models of flow in porous media with shale barriers that illustrate the efficacy of the proposed family of expanded mixed MsFEMs. © 2012 Society for Industrial and Applied Mathematics.

  14. Hierarchical multiscale modeling for flows in fractured media using generalized multiscale finite element method

    Efendiev, Yalchin R.

    2015-06-05

    In this paper, we develop a multiscale finite element method for solving flows in fractured media. Our approach is based on generalized multiscale finite element method (GMsFEM), where we represent the fracture effects on a coarse grid via multiscale basis functions. These multiscale basis functions are constructed in the offline stage via local spectral problems following GMsFEM. To represent the fractures on the fine grid, we consider two approaches (1) discrete fracture model (DFM) (2) embedded fracture model (EFM) and their combination. In DFM, the fractures are resolved via the fine grid, while in EFM the fracture and the fine grid block interaction is represented as a source term. In the proposed multiscale method, additional multiscale basis functions are used to represent the long fractures, while short-size fractures are collectively represented by a single basis functions. The procedure is automatically done via local spectral problems. In this regard, our approach shares common concepts with several approaches proposed in the literature as we discuss. We would like to emphasize that our goal is not to compare DFM with EFM, but rather to develop GMsFEM framework which uses these (DFM or EFM) fine-grid discretization techniques. Numerical results are presented, where we demonstrate how one can adaptively add basis functions in the regions of interest based on error indicators. We also discuss the use of randomized snapshots (Calo et al. Randomized oversampling for generalized multiscale finite element methods, 2014), which reduces the offline computational cost.

  15. Multiscale Processes in Magnetic Reconnection

    Surjalal Sharma, A.; Jain, Neeraj

    The characteristic scales of the plasma processes in magnetic reconnection range from the elec-tron skin-depth to the magnetohydrodynamic (MHD) scale, and cross-scale coupling among them play a key role. Modeling these processes requires different physical models, viz. kinetic, electron-magnetohydrodynamics (EMHD), Hall-MHD, and MHD. The shortest scale processes are at the electron scale and these are modeled using an EMHD code, which provides many features of the multiscale behavior. In simulations using initial conditions consisting of pertur-bations with many scale sizes the reconnection takes place at many sites and the plasma flows from these interact with each other. This leads to thin current sheets with length less than 10 electron skin depths. The plasma flows also generate current sheets with multiple peaks, as observed by Cluster. The quadrupole structure of the magnetic field during reconnection starts on the electron scale and the interaction of inflow to the secondary sites and outflow from the dominant site generates a nested structure. In the outflow regions, the interaction of the electron outflows generated at the neighboring sites lead to the development of electron vortices. A signature of the nested structure of the Hall field is seen in Cluster observations, and more details of these features are expected from MMS.

  16. Multiscale reconstruction for MR fingerprinting.

    Pierre, Eric Y; Ma, Dan; Chen, Yong; Badve, Chaitra; Griswold, Mark A

    2016-06-01

    To reduce the acquisition time needed to obtain reliable parametric maps with Magnetic Resonance Fingerprinting. An iterative-denoising algorithm is initialized by reconstructing the MRF image series at low image resolution. For subsequent iterations, the method enforces pixel-wise fidelity to the best-matching dictionary template then enforces fidelity to the acquired data at slightly higher spatial resolution. After convergence, parametric maps with desirable spatial resolution are obtained through template matching of the final image series. The proposed method was evaluated on phantom and in vivo data using the highly undersampled, variable-density spiral trajectory and compared with the original MRF method. The benefits of additional sparsity constraints were also evaluated. When available, gold standard parameter maps were used to quantify the performance of each method. The proposed approach allowed convergence to accurate parametric maps with as few as 300 time points of acquisition, as compared to 1000 in the original MRF work. Simultaneous quantification of T1, T2, proton density (PD), and B0 field variations in the brain was achieved in vivo for a 256 × 256 matrix for a total acquisition time of 10.2 s, representing a three-fold reduction in acquisition time. The proposed iterative multiscale reconstruction reliably increases MRF acquisition speed and accuracy. Magn Reson Med 75:2481-2492, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  17. Radio Wave Propagation Handbook for Communication on and Around Mars

    Ho, Christian; Golshan, Nasser; Kliore, Arvydas

    2002-01-01

    This handbook examines the effects of the Martian environment on radio wave propagation on Mars and in the space near the planet. The environmental effects include these from the Martian atmosphere, ionosphere, global dust storms, aerosols, clouds, and geomorphologic features. Relevant Martian environmental parameters were extracted from the measurements of Mars missions during the past 30 years, especially from Mars Pathfinder and Mars Global Surveyor. The results derived from measurements and analyses have been reviewed through an extensive literature search. The updated parameters have been theoretically analyzed to study their effects on radio propagation. This handbook also provides basic information about the entire telecommunications environment on and around Mars for propagation researchers, system engineers, and link analysts. Based on these original analyses, some important recommendations have been made, including the use of the Martian ionosphere as a reflector for Mars global or trans-horizon communication between future Martian colonies, reducing dust storm scattering effects, etc. These results have extended our wave propagation knowledge to a planet other than Earth; and the tables, models, and graphics included in this handbook will benefit telecommunication system engineers and scientific researchers.

  18. Multiscale modeling in biomechanics and mechanobiology

    Hwang, Wonmuk; Kuhl, Ellen

    2015-01-01

    Presenting a state-of-the-art overview of theoretical and computational models that link characteristic biomechanical phenomena, this book provides guidelines and examples for creating multiscale models in representative systems and organisms. It develops the reader's understanding of and intuition for multiscale phenomena in biomechanics and mechanobiology, and introduces a mathematical framework and computational techniques paramount to creating predictive multiscale models.   Biomechanics involves the study of the interactions of physical forces with biological systems at all scales – including molecular, cellular, tissue and organ scales. The emerging field of mechanobiology focuses on the way that cells produce and respond to mechanical forces – bridging the science of mechanics with the disciplines of genetics and molecular biology. Linking disparate spatial and temporal scales using computational techniques is emerging as a key concept in investigating some of the complex problems underlying these...

  19. Guidelines for 2008 MARS exercise

    HR Department

    2008-01-01

    Full details of the Merit Appraisal and Recognition Scheme (MARS) are available via the HR Department’s homepage or directly on the Department’s MARS web page: https://cern.ch/hr-dept/ https://cern.ch/hr-eguide/mars/mars.asp You will find on these pages: MARS procedures including the MARS timetable for proposals and decisions; Regulations with links to the scheme’s statutory basis; Frequently Asked Questions; Useful documents with links to relevant documentation; e.g. mandate of the Senior Staff Advisory Committee (SSAC); Related links and contacts. HR Department Tel. 73566

  20. Deductive multiscale simulation using order parameters

    Ortoleva, Peter J.

    2017-05-16

    Illustrative embodiments of systems and methods for the deductive multiscale simulation of macromolecules are disclosed. In one illustrative embodiment, a deductive multiscale simulation method may include (i) constructing a set of order parameters that model one or more structural characteristics of a macromolecule, (ii) simulating an ensemble of atomistic configurations for the macromolecule using instantaneous values of the set of order parameters, (iii) simulating thermal-average forces and diffusivities for the ensemble of atomistic configurations, and (iv) evolving the set of order parameters via Langevin dynamics using the thermal-average forces and diffusivities.

  1. Multiscale phase inversion of seismic marine data

    Fu, Lei

    2017-08-17

    We test the feasibility of applying multiscale phase inversion (MPI) to seismic marine data. To avoid cycle-skipping, the multiscale strategy temporally integrates the traces several times, i.e. high-order integration, to produce low-boost seismograms that are used as input data for the initial iterations of MPI. As the iterations proceed, higher frequencies in the data are boosted by using integrated traces of lower order as the input data. Results with synthetic data and field data from the Gulf of Mexico produce robust and accurate results if the model does not contain strong velocity contrasts such as salt-sediment interfaces.

  2. Multiscale Modeling of Ceramic Matrix Composites

    Bednarcyk, Brett A.; Mital, Subodh K.; Pineda, Evan J.; Arnold, Steven M.

    2015-01-01

    Results of multiscale modeling simulations of the nonlinear response of SiC/SiC ceramic matrix composites are reported, wherein the microstructure of the ceramic matrix is captured. This micro scale architecture, which contains free Si material as well as the SiC ceramic, is responsible for residual stresses that play an important role in the subsequent thermo-mechanical behavior of the SiC/SiC composite. Using the novel Multiscale Generalized Method of Cells recursive micromechanics theory, the microstructure of the matrix, as well as the microstructure of the composite (fiber and matrix) can be captured.

  3. Correlations of multiscale entropy in the FX market

    Stosic, Darko; Stosic, Dusan; Ludermir, Teresa; Stosic, Tatijana

    2016-09-01

    The regularity of price fluctuations in exchange rates plays a crucial role in FX market dynamics. Distinct variations in regularity arise from economic, social and political events, such as interday trading and financial crisis. This paper applies a multiscale time-dependent entropy method on thirty-three exchange rates to analyze price fluctuations in the FX. Correlation matrices of entropy values, termed entropic correlations, are in turn used to describe global behavior of the market. Empirical results suggest a weakly correlated market with pronounced collective behavior at bi-weekly trends. Correlations arise from cycles of low and high regularity in long-term trends. Eigenvalues of the correlation matrix also indicate a dominant European market, followed by shifting American, Asian, African, and Pacific influences. As a result, we find that entropy is a powerful tool for extracting important information from the FX market.

  4. All-Particle Multiscale Computation of Hypersonic Rarefied Flow

    Jun, E.; Burt, J. M.; Boyd, I. D.

    2011-05-01

    This study examines a new hybrid particle scheme used as an alternative means of multiscale flow simulation. The hybrid particle scheme employs the direct simulation Monte Carlo (DSMC) method in rarefied flow regions and the low diffusion (LD) particle method in continuum flow regions. The numerical procedures of the low diffusion particle method are implemented within an existing DSMC algorithm. The performance of the LD-DSMC approach is assessed by studying Mach 10 nitrogen flow over a sphere with a global Knudsen number of 0.002. The hybrid scheme results show good overall agreement with results from standard DSMC and CFD computation. Subcell procedures are utilized to improve computational efficiency and reduce sensitivity to DSMC cell size in the hybrid scheme. This makes it possible to perform the LD-DSMC simulation on a much coarser mesh that leads to a significant reduction in computation time.

  5. Mars Array Technology Experiment Developed to Test Solar Arrays on Mars

    Landis, Geoffrey A.

    2001-01-01

    Solar arrays will be the power supply for future missions to the planet Mars, including landers, rovers, and eventually human missions to explore the Martian surface. Until Mars Pathfinder landed in July 1997, no solar array had been used on the surface. The MATE package is intended to measure the solar energy reaching the surface, characterize the Martian environment to gather the baseline information required for designing power systems for long-duration missions, and to quantify the performance and degradation of advanced solar cells on the Martian surface. To measure the properties of sunlight reaching the Martian surface, MATE incorporates two radiometers and a visible/NIR spectrometer. The radiometers consist of multiple thermocouple junctions using thin-film technology. These devices generate a voltage proportional to the solar intensity. One radiometer measures the global broadband solar intensity, including both the direct and scattered sunlight, with a field of view of approximately 130. The second radiometer incorporates a slit to measure the direct (unscattered) intensity radiation. The direct radiometer can only be read once per day, with the Sun passing over the slit. The spectrometer measures the global solar spectrum with two 256-element photodiode arrays, one Si sensitive in the visible range (300 to 1100 nm), and a second InGaAs sensitive to the near infrared (900 to 1700 nm). This range covers 86 percent of the total energy from the Sun, with approximately 5-nm resolution. Each photodiode array has its own fiber-optic feed and grating. Although the purpose of the MATE is to gather data useful in designing solar arrays for Mars surface power systems, the radiometer and spectrometer measurements are expected to also provide important scientific data for characterizing the properties of suspended atmospheric dust. In addition to measuring the solar environment of Mars, MATE will measure the performance of five different individual solar cell types

  6. The Effect of Gamma Radiation on Mars Mineral Matrices: Implications for Perchlorate Formation on Mars

    Fox, A. C.; Eigenbrode, J. L.; Pavlov, A.; Lewis, J.

    2017-12-01

    Observations by the Phoenix Wet Chemistry Lab of the Martian surface indicate the presence of perchlorate in high concentrations. Additional observations by the Sample Analysis at Mars and the Viking Landers indirectly support the presence of perchlorate at other localities on Mars. The evidence for perchlorate at several localities on Mars coupled with its detection in Martian meteorite EETA79001 suggests that perchlorate is present globally on Mars. The presence of perchlorate on Mars further complicates the search for organic molecules indicative of past life. While perchlorate is kinetically limited in Martian conditions, the intermediate species associated with its formation or decomposition, such as chlorate or chlorite, could oxidize Martian organic species. As a result, it is vital to understand the mechanism of perchlorate formation on Mars in order to determine its role in the degradation of organics. Here, we explore an alternate mechanism of formation of perchlorate by bombarding Cl-salts and Mars-relevant mineral mixtures with gamma radiation both with and without the presence of liquid water, under vacuum. Previous work has shown that OClO can form from both UV radiation and energetic electrons bombardment of Cl-ices or Cl-salts, which then reacts with either OH- or O-radicals to produce perchlorate. Past research has suggested that liquid water or ice is the source of these hydroxyl and oxygen radicals, which limits the location of perchlorate formation on Mars. We demonstrate that trace amounts of perchlorate are potentially formed in samples containing silica dioxide or iron oxide and Cl-salts both with and without liquid water. Perchlorate was also detected in a portion of samples that were not irradiated, suggesting possible contamination. We did not detect perchlorate in samples that contained sulfate minerals. If perchlorate was formed without liquid water, it is possible that oxide minerals could be a potential source of oxygen radicals

  7. Multivariate Generalized Multiscale Entropy Analysis

    Anne Humeau-Heurtier

    2016-11-01

    Full Text Available Multiscale entropy (MSE was introduced in the 2000s to quantify systems’ complexity. MSE relies on (i a coarse-graining procedure to derive a set of time series representing the system dynamics on different time scales; (ii the computation of the sample entropy for each coarse-grained time series. A refined composite MSE (rcMSE—based on the same steps as MSE—also exists. Compared to MSE, rcMSE increases the accuracy of entropy estimation and reduces the probability of inducing undefined entropy for short time series. The multivariate versions of MSE (MMSE and rcMSE (MrcMSE have also been introduced. In the coarse-graining step used in MSE, rcMSE, MMSE, and MrcMSE, the mean value is used to derive representations of the original data at different resolutions. A generalization of MSE was recently published, using the computation of different moments in the coarse-graining procedure. However, so far, this generalization only exists for univariate signals. We therefore herein propose an extension of this generalized MSE to multivariate data. The multivariate generalized algorithms of MMSE and MrcMSE presented herein (MGMSE and MGrcMSE, respectively are first analyzed through the processing of synthetic signals. We reveal that MGrcMSE shows better performance than MGMSE for short multivariate data. We then study the performance of MGrcMSE on two sets of short multivariate electroencephalograms (EEG available in the public domain. We report that MGrcMSE may show better performance than MrcMSE in distinguishing different types of multivariate EEG data. MGrcMSE could therefore supplement MMSE or MrcMSE in the processing of multivariate datasets.

  8. Remanent magnetism at Mars

    Curtis, S. A.; Ness, N. F.

    1988-01-01

    It is shown that a strong case can be made for an intrinsic magnetic field of dynamo origin for Mars earlier in its history. The typical equatorial magnetic field intensity would have been equal to about 0.01-0.1 gauss. The earlier dynamo activity is no longer extant, but a significant remanent magnetic field may exist. A highly non-dipole magnetic field could result from the remanent magnetization of the surface. Remanent magnetization may thus play an important role in the Mars solar wind interactions, in contrast to Venus with its surface temperatures above the Curie point. The anomalous characteristics of Mars'solar wind interaction compared to that of Venus may be explicable on this basis.

  9. Big data-enabled multiscale serviceability analysis for aging bridges☆

    Yu Liang

    2016-08-01

    Full Text Available This work is dedicated to constructing a multi-scale structural health monitoring system to monitor and evaluate the serviceability of bridges based on the Hadoop Ecosystem (MS-SHM-Hadoop. By taking the advantages of the fault-tolerant distributed file system called the Hadoop Distributed File System (HDFS and high-performance parallel data processing engine called MapReduce programming paradigm, MS-SHM-Hadoop features include high scalability and robustness in data ingestion, fusion, processing, retrieval, and analytics. MS-SHM-Hadoop is a multi-scale reliability analysis framework, which ranges from nationwide bridge-surveys, global structural integrity analysis, and structural component reliability analysis. This Nationwide bridge survey uses deep-learning techniques to evaluate the bridge serviceability according to real-time sensory data or archived bridge-related data such as traffic status, weather conditions and bridge structural configuration. The global structural integrity analysis of a targeted bridge is made by processing and analyzing the measured vibration signals incurred by external loads such as wind and traffic flow. Component-wise reliability analysis is also enabled by the deep learning technique, where the input data is derived from the measured structural load effects, hyper-spectral images, and moisture measurement of the structural components. As one of its major contributions, this work employs a Bayesian network to formulate the integral serviceability of a bridge according to its components serviceability and inter-component correlations. Here the inter-component correlations are jointly specified using a statistics-oriented machine learning method (e.g., association rule learning or structural mechanics modeling and simulation.

  10. Field Simulation of a Drilling Mission to Mars to Search for Subsurface Life

    Stoker, C. R.; Lemke, L. G.; Cannon, H.; Glass, B.; Dunagan, S.; Zavaleta, J.; Miller, D.; Gomez-Elvira, J.

    2005-01-01

    The discovery of near surface ground ice by the Mars Odyssey mission and the abundant evidence for recent Gulley features observed by the Mars Global Surveyor mission support longstanding theoretical arguments for subsurface liquid water on Mars. Thus, implementing the Mars program goal to search for life points to drilling on Mars to reach liquid water, collecting samples and analyzing them with instrumentation to detect in situ organisms and biomarker compounds. Searching for life in the subsurface of Mars will require drilling, sample extraction and handling, and new technologies to find and identify biomarker compounds and search for living organisms. In spite of its obvious advantages, robotic drilling for Mars exploration is in its technological infancy and has yet to be demonstrated in even a terrestrial field environment.

  11. The Gravity Field of Mars From MGS, Mars Odyssey, and MRO Radio Science

    Genova, Antonio; Goossens, Sander; Lemoine, Frank G.; Mazarico, Erwan; Smith, David E.; Zuber, Maria T.

    2015-01-01

    The Mars Global Surveyor (MGS), Mars Odyssey (ODY), and Mars Reconnaissance Orbiter (MRO) missions have enabled NASA to conduct reconnaissance and exploration of Mars from orbit for sixteen consecutive years. These radio systems on these spacecraft enabled radio science in orbit around Mars to improve the knowledge of the static structure of the Martian gravitational field. The continuity of the radio tracking data, which cover more than a solar cycle, also provides useful information to characterize the temporal variability of the gravity field, relevant to the planet's internal dynamics and the structure and dynamics of the atmosphere [1]. MGS operated for more than 7 years, between 1999 and 2006, in a frozen sun-synchronous, near-circular, polar orbit with the periapsis at approximately 370 km altitude. ODY and MRO have been orbiting Mars in two separate sun-synchronous orbits at different local times and altitudes. ODY began its mapping phase in 2002 with the periapis at approximately 390 km altitude and 4-5pm Local Solar Time (LST), whereas the MRO science mission started in November 2006 with the periapis at approximately 255 km altitude and 3pm LST. The 16 years of radio tracking data provide useful information on the atmospheric density in the Martian upper atmosphere. We used ODY and MRO radio data to recover the long-term periodicity of the major atmospheric constituents -- CO2, O, and He -- at the orbit altitudes of these two spacecraft [2]. The improved atmospheric model provides a better prediction of the annual and semi-annual variability of the dominant species. Therefore, the inclusion of the recovered model leads to improved orbit determination and an improved gravity field model of Mars with MGS, ODY, and MRO radio tracking data.

  12. A Multi-scale Modeling System with Unified Physics to Study Precipitation Processes

    Tao, W. K.

    2017-12-01

    In recent years, exponentially increasing computer power has extended Cloud Resolving Model (CRM) integrations from hours to months, the number of computational grid points from less than a thousand to close to ten million. Three-dimensional models are now more prevalent. Much attention is devoted to precipitating cloud systems where the crucial 1-km scales are resolved in horizontal domains as large as 10,000 km in two-dimensions, and 1,000 x 1,000 km2 in three-dimensions. Cloud resolving models now provide statistical information useful for developing more realistic physically based parameterizations for climate models and numerical weather prediction models. It is also expected that NWP and mesoscale model can be run in grid size similar to cloud resolving model through nesting technique. Recently, a multi-scale modeling system with unified physics was developed at NASA Goddard. It consists of (1) a cloud-resolving model (Goddard Cumulus Ensemble model, GCE model), (2) a regional scale model (a NASA unified weather research and forecast, WRF), and (3) a coupled CRM and global model (Goddard Multi-scale Modeling Framework, MMF). The same microphysical processes, long and short wave radiative transfer and land processes and the explicit cloud-radiation, and cloud-land surface interactive processes are applied in this multi-scale modeling system. This modeling system has been coupled with a multi-satellite simulator to use NASA high-resolution satellite data to identify the strengths and weaknesses of cloud and precipitation processes simulated by the model. In this talk, a review of developments and applications of the multi-scale modeling system will be presented. In particular, the results from using multi-scale modeling system to study the precipitation, processes and their sensitivity on model resolution and microphysics schemes will be presented. Also how to use of the multi-satellite simulator to improve precipitation processes will be discussed.

  13. Mars Gashopper Airplane, Phase I

    National Aeronautics and Space Administration — The Mars Gas Hopper Airplane, or "gashopper" is a novel concept for propulsion of a robust Mars flight and surface exploration vehicle that utilizes indigenous CO2...

  14. Frost on Mars

    2008-01-01

    This image shows bluish-white frost seen on the Martian surface near NASA's Phoenix Mars Lander. The image was taken by the lander's Surface Stereo Imager on the 131st Martian day, or sol, of the mission (Oct. 7, 2008). Frost is expected to continue to appear in images as fall, then winter approach Mars' northern plains. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  15. Lakes on Mars

    Cabrol, Nathalie A

    2014-01-01

    On Earth, lakes provide favorable environments for the development of life and its preservation as fossils. They are extremely sensitive to climate fluctuations and to conditions within their watersheds. As such, lakes are unique markers of the impact of environmental changes. Past and current missions have now demonstrated that water once flowed at the surface of Mars early in its history. Evidence of ancient ponding has been uncovered at scales ranging from a few kilometers to possibly that of the Arctic ocean. Whether life existed on Mars is still unknown; upcoming missions may find critic

  16. 'Mars-shine'

    2005-01-01

    [figure removed for brevity, see original site] 'Mars-shine' Composite NASA's Mars Exploration Rover Spirit continues to take advantage of favorable solar power conditions to conduct occasional nighttime astronomical observations from the summit region of 'Husband Hill.' Spirit has been observing the martian moons Phobos and Deimos to learn more about their orbits and surface properties. This has included observing eclipses. On Earth, a solar eclipse occurs when the Moon's orbit takes it exactly between the Sun and Earth, casting parts of Earth into shadow. A lunar eclipse occurs when the Earth is exactly between the Sun and the Moon, casting the Moon into shadow and often giving it a ghostly orange-reddish color. This color is created by sunlight reflected through Earth's atmosphere into the shadowed region. The primary difference between terrestrial and martian eclipses is that Mars' moons are too small to completely block the Sun from view during solar eclipses. Recently, Spirit observed a 'lunar' eclipse on Mars. Phobos, the larger of the two martian moons, was photographed while slipping into the shadow of Mars. Jim Bell, the astronomer in charge of the rover's panoramic camera (Pancam), suggested calling it a 'Phobal' eclipse rather than a lunar eclipse as a way of identifying which of the dozens of moons in our solar system was being cast into shadow. With the help of the Jet Propulsion Laboratory's navigation team, the Pancam team planned instructions to Spirit for acquiring the views shown here of Phobos as it entered into a lunar eclipse on the evening of the rover's 639th martian day, or sol (Oct. 20, 2005) on Mars. This image is a time-lapse composite of eight Pancam images of Phobos moving across the martian sky. The entire eclipse lasted more than 26 minutes, but Spirit was able to observe only in the first 15 minutes. During the time closest to the shadow crossing, Spirit's cameras were programmed to take images every 10 seconds. In the first three

  17. Scientific Payload Of The Emirates Mars Mission: Emirates Mars Infrared Spectrometer (Emirs) Overview.

    Altunaiji, E. S.; Edwards, C. S.; Christensen, P. R.; Smith, M. D.; Badri, K. M., Sr.

    2017-12-01

    The Emirates Mars Mission (EMM) will launch in 2020 to explore the dynamics in the atmosphere of Mars on a global scale. EMM has three scientific instruments to an improved understanding of circulation and weather in the Martian lower and middle atmosphere. Two of the EMM's instruments, which are the Emirates eXploration Imager (EXI) and Emirates Mars Infrared Spectrometer (EMIRS) will focus on the lower atmosphere observing dust, ice clouds, water vapor and ozone. On the other hand, the third instrument Emirates Mars Ultraviolet Spectrometer (EMUS) will focus on both the thermosphere of the planet and its exosphere. The EMIRS instrument, shown in Figure 1, is an interferometric thermal infrared spectrometer that is jointly developed by Arizona State University (ASU) and Mohammed Bin Rashid Space Centre (MBRSC). It builds on a long heritage of thermal infrared spectrometers designed, built, and managed, by ASU's Mars Space Flight Facility, including the Thermal Emission Spectrometer (TES), Miniature Thermal Emission Spectrometer (Mini-TES), and the OSIRIS-REx Thermal Emission Spectrometer (OTES). EMIRS operates in the 6-40+ µm range with 5 cm-1 spectral sampling, enabled by a Chemical Vapor-Deposited (CVD) diamond beamsplitter and state of the art electronics. This instrument utilizes a 3×3 detector array and a scan mirror to make high-precision infrared radiance measurements over most of a Martian hemisphere. The EMIRS instrument is optimized to capture the integrated, lower-middle atmosphere dynamics over a Martian hemisphere and will capture 60 global images per week ( 20 images per orbit) at a resolution of 100-300 km/pixel. After processing through an atmospheric retrieval algorithm, EMIRS will determine the vertical temperature profiles to 50km altitude and measure the column integrated global distribution and abundances of key atmospheric parameters (e.g. dust, water ice (clouds) and water vapor) over the Martian day, seasons and year.

  18. A multiscale approach to mutual information matching

    Pluim, J.P.W.; Maintz, J.B.A.; Viergever, M.A.; Hanson, K.M.

    1998-01-01

    Methods based on mutual information have shown promising results for matching of multimodal brain images. This paper discusses a multiscale approach to mutual information matching, aiming for an acceleration of the matching process while considering the accuracy and robustness of the method. Scaling

  19. Multiscale Lyapunov exponent for 2-microlocal functions

    Dhifaoui, Zouhaier; Kortas, Hedi; Ammou, Samir Ben

    2009-01-01

    The Lyapunov exponent is an important indicator of chaotic dynamics. Using wavelet analysis, we define a multiscale representation of this exponent which we demonstrate the scale-wise dependence for functions belonging to C x 0 s,s ' spaces. An empirical study involving simulated processes and financial time series corroborates the theoretical findings.

  20. Multiscale phenomenology of the cosmic web

    Aragón-Calvo, Miguel A.; van de Weygaert, Rien; Jones, Bernard J. T.

    2010-01-01

    We analyse the structure and connectivity of the distinct morphologies that define the cosmic web. With the help of our multiscale morphology filter (MMF), we dissect the matter distribution of a cosmological Lambda cold dark matter N-body computer simulation into cluster, filaments and walls. The

  1. Multiscale Phase Inversion of Seismic Data

    Fu, Lei; Guo, Bowen; Sun, Yonghe; Schuster, Gerard T.

    2017-01-01

    -skipping, the multiscale strategy temporally integrates the traces several times, i.e. high-order integration, to produce low-boost seismograms that are used as input data for the initial iterations of MPI. As the iterations proceed, higher frequencies in the data

  2. Multiscale Modeling of Poromechanics in Geologic Media

    Castelletto, N.; Hajibeygi, H.; Klevtsov, S.; Tchelepi, H.

    2017-12-01

    We describe a hybrid MultiScale Finite Element-Finite Volume (h-MSFE-FV) framework for the simulation of single-phase Darcy flow through deformable porous media that exhibit highly heterogeneous poromechanical properties over a wide range of length scales. In such systems, high resolution characterizations are a key requirement to obtain reliable modeling predictions and motivate the development of multiscale solution strategies to cope with the computational burden. A coupled two-field fine-scale mixed FE-FV discretization of the governing equations, namely conservation laws of linear momentum and mass, is first implemented based on a displacement-pressure formulation. After imposing a coarse-scale grid on the given fine-scale problem, for the MSFE displacement stage, the coarse-scale basis functions are obtained by solving local equilibrium problems within coarse elements. Such MSFE stage is then coupled with the MSFV method for flow, in which a dual-coarse grid is introduced to obtain approximate but conservative multiscale solutions. Robustness and accuracy of the proposed multiscale framework is demonstrated using a variety of challenging test problems.

  3. Multiscale empirical interpolation for solving nonlinear PDEs

    Calo, Victor M.; Efendiev, Yalchin R.; Galvis, Juan; Ghommem, Mehdi

    2014-01-01

    residuals and Jacobians on the fine grid. We use empirical interpolation concepts to evaluate these residuals and Jacobians of the multiscale system with a computational cost which is proportional to the size of the coarse-scale problem rather than the fully

  4. Multiscale information modelling for heart morphogenesis

    Abdulla, T; Imms, R; Summers, R [Department of Electronic and Electrical Engineering, Loughborough University, Loughborough (United Kingdom); Schleich, J M, E-mail: T.Abdulla@lboro.ac.u [LTSI Signal and Image Processing Laboratory, University of Rennes 1, Rennes (France)

    2010-07-01

    Science is made feasible by the adoption of common systems of units. As research has become more data intensive, especially in the biomedical domain, it requires the adoption of a common system of information models, to make explicit the relationship between one set of data and another, regardless of format. This is being realised through the OBO Foundry to develop a suite of reference ontologies, and NCBO Bioportal to provide services to integrate biomedical resources and functionality to visualise and create mappings between ontology terms. Biomedical experts tend to be focused at one level of spatial scale, be it biochemistry, cell biology, or anatomy. Likewise, the ontologies they use tend to be focused at a particular level of scale. There is increasing interest in a multiscale systems approach, which attempts to integrate between different levels of scale to gain understanding of emergent effects. This is a return to physiological medicine with a computational emphasis, exemplified by the worldwide Physiome initiative, and the European Union funded Network of Excellence in the Virtual Physiological Human. However, little work has been done on how information modelling itself may be tailored to a multiscale systems approach. We demonstrate how this can be done for the complex process of heart morphogenesis, which requires multiscale understanding in both time and spatial domains. Such an effort enables the integration of multiscale metrology.

  5. Multiscale information modelling for heart morphogenesis

    Abdulla, T; Imms, R; Summers, R; Schleich, J M

    2010-01-01

    Science is made feasible by the adoption of common systems of units. As research has become more data intensive, especially in the biomedical domain, it requires the adoption of a common system of information models, to make explicit the relationship between one set of data and another, regardless of format. This is being realised through the OBO Foundry to develop a suite of reference ontologies, and NCBO Bioportal to provide services to integrate biomedical resources and functionality to visualise and create mappings between ontology terms. Biomedical experts tend to be focused at one level of spatial scale, be it biochemistry, cell biology, or anatomy. Likewise, the ontologies they use tend to be focused at a particular level of scale. There is increasing interest in a multiscale systems approach, which attempts to integrate between different levels of scale to gain understanding of emergent effects. This is a return to physiological medicine with a computational emphasis, exemplified by the worldwide Physiome initiative, and the European Union funded Network of Excellence in the Virtual Physiological Human. However, little work has been done on how information modelling itself may be tailored to a multiscale systems approach. We demonstrate how this can be done for the complex process of heart morphogenesis, which requires multiscale understanding in both time and spatial domains. Such an effort enables the integration of multiscale metrology.

  6. Multiscale approach to equilibrating model polymer melts

    Svaneborg, Carsten; Ali Karimi-Varzaneh, Hossein; Hojdis, Nils

    2016-01-01

    We present an effective and simple multiscale method for equilibrating Kremer Grest model polymer melts of varying stiffness. In our approach, we progressively equilibrate the melt structure above the tube scale, inside the tube and finally at the monomeric scale. We make use of models designed...

  7. Multiscale optimization of saturated poroelastic actuators

    Andreasen, Casper Schousboe; Sigmund, Ole

    A multiscale method for optimizing the material micro structure in a macroscopically heterogeneous saturated poroelastic media with respect to macro properties is presented. The method is based on topology optimization using the homogenization technique, here applied to the optimization of a bi...

  8. Generalized multiscale finite element methods: Oversampling strategies

    Efendiev, Yalchin R.; Galvis, Juan; Li, Guanglian; Presho, Michael

    2014-01-01

    In this paper, we propose oversampling strategies in the generalized multiscale finite element method (GMsFEM) framework. The GMsFEM, which has been recently introduced in Efendiev et al. (2013b) [Generalized Multiscale Finite Element Methods, J. Comput. Phys., vol. 251, pp. 116-135, 2013], allows solving multiscale parameter-dependent problems at a reduced computational cost by constructing a reduced-order representation of the solution on a coarse grid. The main idea of the method consists of (1) the construction of snapshot space, (2) the construction of the offline space, and (3) construction of the online space (the latter for parameter-dependent problems). In Efendiev et al. (2013b) [Generalized Multiscale Finite Element Methods, J. Comput. Phys., vol. 251, pp. 116-135, 2013], it was shown that the GMsFEM provides a flexible tool to solve multiscale problems with a complex input space by generating appropriate snapshot, offline, and online spaces. In this paper, we develop oversampling techniques to be used in this context (see Hou and Wu (1997) where oversampling is introduced for multiscale finite element methods). It is known (see Hou and Wu (1997)) that the oversampling can improve the accuracy of multiscale methods. In particular, the oversampling technique uses larger regions (larger than the target coarse block) in constructing local basis functions. Our motivation stems from the analysis presented in this paper, which shows that when using oversampling techniques in the construction of the snapshot space and offline space, GMsFEM will converge independent of small scales and high contrast under certain assumptions. We consider the use of a multiple eigenvalue problems to improve the convergence and discuss their relation to single spectral problems that use oversampled regions. The oversampling procedures proposed in this paper differ from those in Hou and Wu (1997). In particular, the oversampling domains are partially used in constructing local

  9. Mars at war

    2018-04-01

    Whether the climate of early Mars was warm and wet or cold and dry remains unclear, but the debate is overheated. With a growing toolbox and increasing data to tackle the open questions, progress is possible if there is openness to bridging the divide.

  10. Watersporen op Mars

    Seijmonsbergen, A.C.; Cammeraat, L.H.; Jansen, B.

    2005-01-01

    SAMENVATTING De discussie over het voorkomen van water op Mars, in vaste of vloeibare vorm, nu en in het verleden, is nog steeds in volle gang. Dat geldt ook voor het effect van mogelijk aanwezig water op de landschapsontwikkeling van de Rode Planeet. Met het vrijkomen van steeds meer nieuwe

  11. Ancient aliens on mars

    Bara, Mike

    2013-01-01

    Best-selling author and Secret Space Program researcher Bara brings us this lavishly illustrated volume on alien structures on Mars. Was there once a vast, technologically advanced civilization on Mars, and did it leave evidence of its existence behind for humans to find eons later? Did these advanced extraterrestrial visitors vanish in a solar system wide cataclysm of their own making, only to make their way to Earth and start anew? Was Mars once as lush and green as the Earth, and teeming with life? Did Mars once orbit a missing member of the solar system, a "Super Earth” that vanished in a disaster that devastated life on Earth and Venus and left us only the asteroid belt as evidence of its once grand existence? Did the survivors of this catastrophe leave monuments and temples behind, arranged in a mathematical precision designed to teach us the Secret of a new physics that could lift us back to the stars? Does the planet have an automated defense shield that swallows up robotic probes if they wander int...

  12. Mars Mission Specialist

    Burton, Bill; Ogden, Kate; Walker, Becky; Bledsoe, Leslie; Hardage, Lauren

    2018-01-01

    For the last several years, the authors have implemented an integrated Mars Colony project for their third-grade classes. Students explored several considerations related to colonizing and inhabiting a new world, including food sources, types of citizens, transportation, and housing design. Nearly everything about the project was open-ended, full…

  13. The Small Mars System

    Fantino, E.; Grassi, M.; Pasolini, P.; Causa, F.; Molfese, C.; Aurigemma, R.; Cimminiello, N.; de la Torre, D.; Dell'Aversana, P.; Esposito, F.; Gramiccia, L.; Paudice, F.; Punzo, F.; Roma, I.; Savino, R.; Zuppardi, G.

    2017-08-01

    The Small Mars System is a proposed mission to Mars. Funded by the European Space Agency, the project has successfully completed Phase 0. The contractor is ALI S.c.a.r.l., and the study team includes the University of Naples ;Federico II;, the Astronomical Observatory of Capodimonte and the Space Studies Institute of Catalonia. The objectives of the mission are both technological and scientific, and will be achieved by delivering a small Mars lander carrying a dust particle analyser and an aerial drone. The former shall perform in situ measurements of the size distribution and abundance of dust particles suspended in the Martian atmosphere, whereas the latter shall demonstrate low-altitude flight in the rarefied planetary environment. The mission-enabling technology is an innovative umbrella-like heat shield, known as IRENE, developed and patented by ALI. The mission is also a technological demonstration of the shield in the upper atmosphere of Mars. The core characteristics of SMS are the low cost (120 M€) and the small size (320 kg of wet mass at launch, 110 kg at landing), features which stand out with respect to previous Mars landers. To comply with them is extremely challenging at all levels, and sets strict requirements on the choice of the materials, the sizing of payloads and subsystems, their arrangement inside the spacecraft and the launcher's selection. In this contribution, the mission and system concept and design are illustrated and discussed. Special emphasis is given to the innovative features and to the challenges faced in the development of the work.

  14. Mars Surface Environmental Issues

    Charles, John

    2002-01-01

    Planetary exploration by astronauts will require extended periods of habitation on a planet's surface, under the influence of environmental factors that are different from those of Earth and the spacecraft that delivered the crew to the planet. Human exploration of Mars, a possible near-term planetary objective, can be considered a challenging scenario. Mission scenarios currently under consideration call for surface habitation periods of from 1 to 18 months on even the earliest expeditions. Methods: Environmental issues associated with Mars exploration have been investigated by NASA and the National Space Biomedical Research Institute (NSBRI) as part of the Bioastronautics Critical Path Roadmap Project (see http ://criticalpath.jsc.nasa.gov). Results: Arrival on Mars will immediately expose the crew to gravity only 38% of that at Earth's surface in possibly the first prolonged exposure to gravity other than the 1G of Earth's surface and the zero G of weightless space flight, with yet unknown effects on crew physiology. The radiation at Mars' surface is not well documented, although the planet's bulk and even its thin atmosphere may moderate the influx of galactic cosmic radiation and energetic protons from solar flares. Secondary radiation from activated components of the soil must also be considered. Ultrafine and larger respirable and nonrespirable particles in Martian dust introduced into the habitat after surface excursions may induce pulmonary inflammation exacerbated by the additive reactive and oxidizing nature of the dust. Stringent decontamination cannot eliminate mechanical and corrosive effects of the dust on pressure suits and exposed machinery. The biohazard potential of putative indigenous Martian microorganisms may be assessed by comparison with analog environments on Earth. Even in their absence, human microorganisms, if not properly controlled, can be a threat to the crew's health. Conclusions: Mars' surface offers a substantial challenge to the

  15. Smectite Formation in Acid Sulfate Environments on Mars

    Peretyazhko, T. S.; Niles, P. B.; Sutter, B.; Clark, J. V.; Morris, R. V.; Ming, D. W.

    2017-01-01

    Phyllosilicates of the smectite group detected in Noachian and early Hesperian terrains on Mars were hypothesized to form under aqueous conditions that were globally neutral to alkaline. These pH conditions and the presence of a CO2-rich atmosphere should have been favorable for the formation of large carbonate deposits. However, large-scale carbonate deposits have not been detected on Mars. We hypothesized that smectite deposits are consistent with perhaps widespread acidic aqueous conditions that prevented carbonate precipitation. The objective of our work was to investigate smectite formation under acid sulfate conditions in order to provide insight into the possible geochemical conditions required for smectite formation on Mars. Hydrothermal batch incubation experiments were performed with Mars-analogue, glass-rich, basalt simulant in the presence of sulfuric acid of variable concentration.

  16. More about the moment of inertia of Mars

    Kaula, W.M.; Sleep, N.H.; Phillips, R.J.

    1989-01-01

    The maximum allowable mean moment-of-inertia I of Mars is 0.3650 ·MR 2 because the rate-of-adjustment of the rotation axis is much faster than the rate-of-generation of density heterogeneities, as with any planet. But Mars differs from the other terrestrial planets in that its gravity field is rougher, in the sense of stress-difference implication, and its global tectonics is dominated by one feature, centered on the Tharsis Plateau. Plausible tectonic models of Mars require generation and support that are almost axially symmetric about Tharsis. Hence, unlike other terrestrial planets, Mars likely has two non-hydrostatic components of moments-of-inertia that are nearly equal, and the most probable value of I/MR 2 is slightly less than 0.3650

  17. Mars Orbiter Camera Views the 'Face on Mars' - Best View from Viking

    1998-01-01

    Shortly after midnight Sunday morning (5 April 1998 12:39 AM PST), the Mars Orbiter Camera (MOC) on the Mars Global Surveyor (MGS) spacecraft successfully acquired a high resolution image of the 'Face on Mars' feature in the Cydonia region. The image was transmitted to Earth on Sunday, and retrieved from the mission computer data base Monday morning (6 April 1998). The image was processed at the Malin Space Science Systems (MSSS) facility 9:15 AM and the raw image immediately transferred to the Jet Propulsion Laboratory (JPL) for release to the Internet. The images shown here were subsequently processed at MSSS.The picture was acquired 375 seconds after the spacecraft's 220th close approach to Mars. At that time, the 'Face', located at approximately 40.8o N, 9.6o W, was 275 miles (444 km) from the spacecraft. The 'morning' sun was 25o above the horizon. The picture has a resolution of 14.1 feet (4.3 meters) per pixel, making it ten times higher resolution than the best previous image of the feature, which was taken by the Viking Mission in the mid-1970's. The full image covers an area 2.7 miles (4.4 km) wide and 25.7 miles (41.5 km) long.This Viking Orbiter image is one of the best Viking pictures of the area Cydonia where the 'Face' is located. Marked on the image are the 'footprint' of the high resolution (narrow angle) Mars Orbiter Camera image and the area seen in enlarged views (dashed box). See PIA01440-1442 for these images in raw and processed form.Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  18. Gravity Waves in the Atmosphere of Mars as seen by the Radio Science Experiment MaRS on Mars Express

    Tellmann, S.; Paetzold, M.; Häusler, B.; Bird, M. K.; Tyler, G. L.; Hinson, D. P.

    2016-12-01

    Gravity waves are atmospheric waves whose restoring force is the buoyancy. They are known to play an essential role in the redistribution of energy, momentum and atmospheric constituents in all stably stratified planetary atmospheres. Possible excitation mechanisms comprise convection in an adjacent atmospheric layer, other atmospheric instabilities like wind shear instabilities, or air flow over orographic obstacles especially in combination with the strong winter jets on Mars. Gravity waves on Mars were observed in the lower atmosphere [1,2] but are also expected to play a major role in the cooling of the thermosphere [3] and the polar warming [4]. A fundamental understanding of the possible source mechanisms is required to reveal the influence of small scale gravity waves on the global atmospheric circulation. Radio occultation profiles from the MaRS experiment on Mars Express [5] with their exceptionally high vertical resolution can be used to study small-scale vertical gravity waves and their global distribution in the lower atmosphere from the planetary boundary layer up to 40 km altitude. Atmospheric instabilities, which are clearly identified in the data, are used to gain further insight into possible atmospheric processes contributing to the excitation of gravity waves. [1] Creasey, J. E., et al.,(2006), Geophys. Res. Lett., 33, L01803, doi:10.1029/2005GL024037. [2]Tellmann, S., et al.(2013), J. Geophys. Res. Planets, 118, 306-320, doi:10.1002/jgre.20058. [3]Medvedev, A. S., et al.(2015), J. Geophys. Res. Planets, 120, 913-927. doi:10.1002/2015JE004802.[4] Barnes, J. R. (1990), J. Geophys. Res., 95, B2, 1401-1421. [5] Pätzold, M., et al. (2016), Planet. Space Sci., 127, 44 - 90.

  19. The Multiscale Fluctuations of the Correlation between Oil Price and Wind Energy Stock

    Shupei Huang

    2016-06-01

    Full Text Available Wind energy is considered a clear and sustainable substitution for fossil fuel, and the stock index of the wind energy industry is closely related to the oil price fluctuation. Their relationship is characterized by multiscale and time-varying features based on a variety of stakeholders who have different objectives within various time horizons, which makes it difficult to identify the factor in which time scale could be the most influential one in the market. Aiming to explore the correlation between oil price and the wind energy stock index from the time–frequency domain in a dynamic perspective, we propose an algorithm combining the wavelet transform, complex network, and gray correlation analyses and choose the Brent oil price and the international securities exchange (ISE global wind energy index from January 2006 to October 2015 in daily frequency as data sample. First, we define the multiscale conformation by a set of fluctuation information with different time horizons to represent the fluctuation status of the correlation of the oil–wind nexus rather than by a single original correlation value. Then, we transform the multiscale conformation evolution into a network model, and only 270 multiscale conformations and 710 transmissions could characterize 2451 data points. We find that only 30% of conformations and transmissions work as a backbone of the entire correlation series; through these major conformations, we identify that the main factor that could influence the oil–wind nexus are long-term components, such as policies, the status of the global economy and demand–supply issues. In addition, there is a clustering effect and transmissions among conformations that mainly happen inside clusters and rarely among clusters, which means the interaction of the oil–wind nexus is stable over a short period of time.

  20. Improved convergence of gradient-based reconstruction using multi-scale models

    Cunningham, G.S.; Hanson, K.M.; Koyfman, I.

    1996-01-01

    Geometric models have received increasing attention in medical imaging for tasks such as segmentation, reconstruction, restoration, and registration. In order to determine the best configuration of the geometric model in the context of any of these tasks, one needs to perform a difficult global optimization of an energy function that may have many local minima. Explicit models of geometry, also called deformable models, snakes, or active contours, have been used extensively to solve image segmentation problems in a non-Bayesian framework. Researchers have seen empirically that multi-scale analysis is useful for convergence to a configuration that is near the global minimum. In this type of analysis, the image data are convolved with blur functions of increasing resolution, and an optimal configuration of the snake is found for each blurred image. The configuration obtained using the highest resolution blur is used as the solution to the global optimization problem. In this article, the authors use explicit models of geometry for a variety of Bayesian estimation problems, including image segmentation, reconstruction and restoration. The authors introduce a multi-scale approach that blurs the geometric model, rather than the image data, and show that this approach turns a global, highly nonquadratic optimization into a sequence of local, approximately quadratic problems that converge to the global minimum. The result is a deterministic, robust, and efficient optimization strategy applicable to a wide variety of Bayesian estimation problems in which geometric models of images are an important component

  1. MAVEN Observations of Atmospheric Loss at Mars

    Curry, Shannon; Luhmann, Janet; Jakosky, Bruce M.; Brain, David; LeBlanc, Francis; Modolo, Ronan; Halekas, Jasper S.; Schneider, Nicholas M.; Deighan, Justin; McFadden, James; Espley, Jared R.; Mitchell, David L.; Connerney, J. E. P.; Dong, Yaxue; Dong, Chuanfei; Ma, Yingjuan; Cohen, Ofer; Fränz, Markus; Holmström, Mats; Ramstad, Robin; Hara, Takuya; Lillis, Robert J.

    2016-06-01

    The Mars Atmosphere and Volatile EvolutioN (MAVEN) mission has been making observations of the Martian upper atmosphere and its escape to space since November 2014. The subject of atmospheric loss at terrestrial planets is a subject of intense interest not only because of the implications for past and present water reservoirs, but also for its impacts on the habitability of a planet. Atmospheric escape may have been especially effective at Mars, relative to Earth or Venus, due to its smaller size as well as the lack of a global dynamo magnetic field. Not only is the atmosphere less gravitationally bound, but also the lack of global magnetic field allows the impinging solar wind to interact directly with the Martian atmosphere. When the upper atmosphere is exposed to the solar wind, planetary neutrals can be ionized and 'picked up' by the solar wind and swept away.Both neutral and ion escape have played significant roles the long term climate change of Mars, and the MAVEN mission was designed to directly measure both escaping planetary neutrals and ions with high energy, mass, and time resolution. We will present 1.5 years of observations of atmospheric loss at Mars over a variety of solar and solar wind conditions, including extreme space weather events. We will report the average ion escape rate and the spatial distribution of escaping ions as measured by MAVEN and place them in context both with previous measurements of ion loss by other spacecraft (e.g. Phobos 2 and Mars Express) and with estimates of neutral escape rates by MAVEN. We will then report on the measured variability in ion escape rates with different drivers (e.g. solar EUV, solar wind pressure, etc.) and the implications for the total ion escape from Mars over time. Additionally, we will also discuss the implications for atmospheric escape at exoplanets, particularly weakly magnetized planetary bodies orbiting M-dwarfs, and the dominant escape mechanisms that may drive atmospheric erosion in other

  2. Multiscale impact of fuel consumption on air quality

    Hidy, G.M. [Envair/Aerochem, Placitas, NM (USA)

    2002-04-01

    Energy production from combustion of fossil fuels tends to dominate the emissions of criteria pollutants. Emissions derive both from large stationary sources with tall stacks such as fossil-fuelled power plants, and from the ground level use of fuels in transportation. Management of these sources presents a challenge in the light of multi-scale processes that influence ambient concentration and exposure patterns. Directly emitted pollutants and those resulting from atmospheric chemistry, like O{sub 3} and sulfate, nitrate and some organic material in fine particles, are affected by phenomena extending over a range of less than a meter to 10{sup 7} meters in spatial scale, and minutes to many years in temporal scale. Their environmental effects have an analogous wide range of descriptive spatial and temporal scale. Pollution phenomena can be thought of in terms of three major groupings: neighbourhood - urban, regional, and continental - global. Currently, decision-makers are developing emission reduction strategies that conceptually integrate considerations over this entire range of scales. In keeping with conceptual integration, recent studies and analyses are bridging different spatial and temporal scales in observations and in mathematical descriptions. Some examples of contemporary issues falling within different scales are described that illustrate approaches to add insight for developing regulatory strategies. A key element in the technical approaches is the application of air quality and exposure modeling using spatially nested descriptions of atmospheric phenomena. The reliability of multi-scale models remains a concern so that analyses for US regulatory applications combine the results of modeling with observations, and knowledge of spatially and temporally differentiated emissions. 32 refs., 3 tabs.

  3. The magnetic field in the pile-up region at Mars, and its variation with the solar wind

    Vennerstrøm, Susanne; Olsen, Nils; Purucker, M.

    2003-01-01

    [1] The magnetic measurements from the Mars Global Surveyor satellite are used to study the magnetic field on the Martian dayside, and its variation with the solar wind. Because of the lack of solar wind measurements near Mars, solar wind measurements near Earth during a period centered on a Mars......-Earth conjunction are used. Concurrent variations at Mars and Earth related to the interplanetary sector-structure and dynamic pressure variations are demonstrated. The study is confined to the northern hemisphere of Mars in regions where the crustal anomalies are weak. Here we find a close association between...

  4. A mathematical framework for multiscale science and engineering: the variational multiscale method and interscale transfer operators

    Shadid, John Nicolas; Lehoucq, Richard B.; Christon, Mark Allen; Slepoy, Alexander; Bochev, Pavel Blagoveston; Collis, Samuel Scott; Wagner, Gregory John

    2004-01-01

    Existing approaches in multiscale science and engineering have evolved from a range of ideas and solutions that are reflective of their original problem domains. As a result, research in multiscale science has followed widely diverse and disjoint paths, which presents a barrier to cross pollination of ideas and application of methods outside their application domains. The status of the research environment calls for an abstract mathematical framework that can provide a common language to formulate and analyze multiscale problems across a range of scientific and engineering disciplines. In such a framework, critical common issues arising in multiscale problems can be identified, explored and characterized in an abstract setting. This type of overarching approach would allow categorization and clarification of existing models and approximations in a landscape of seemingly disjoint, mutually exclusive and ad hoc methods. More importantly, such an approach can provide context for both the development of new techniques and their critical examination. As with any new mathematical framework, it is necessary to demonstrate its viability on problems of practical importance. At Sandia, lab-centric, prototype application problems in fluid mechanics, reacting flows, magnetohydrodynamics (MHD), shock hydrodynamics and materials science span an important subset of DOE Office of Science applications and form an ideal proving ground for new approaches in multiscale science.

  5. Multiscale Simulations for Coupled Flow and Transport Using the Generalized Multiscale Finite Element Method

    Chung, Eric

    2015-12-11

    In this paper, we develop a mass conservative multiscale method for coupled flow and transport in heterogeneous porous media. We consider a coupled system consisting of a convection-dominated transport equation and a flow equation. We construct a coarse grid solver based on the Generalized Multiscale Finite Element Method (GMsFEM) for a coupled system. In particular, multiscale basis functions are constructed based on some snapshot spaces for the pressure and the concentration equations and some local spectral decompositions in the snapshot spaces. The resulting approach uses a few multiscale basis functions in each coarse block (for both the pressure and the concentration) to solve the coupled system. We use the mixed framework, which allows mass conservation. Our main contributions are: (1) the development of a mass conservative GMsFEM for the coupled flow and transport; (2) the development of a robust multiscale method for convection-dominated transport problems by choosing appropriate test and trial spaces within Petrov-Galerkin mixed formulation. We present numerical results and consider several heterogeneous permeability fields. Our numerical results show that with only a few basis functions per coarse block, we can achieve a good approximation.

  6. Multiscale Simulations for Coupled Flow and Transport Using the Generalized Multiscale Finite Element Method

    Chung, Eric; Efendiev, Yalchin R.; Leung, Wing; Ren, Jun

    2015-01-01

    In this paper, we develop a mass conservative multiscale method for coupled flow and transport in heterogeneous porous media. We consider a coupled system consisting of a convection-dominated transport equation and a flow equation. We construct a coarse grid solver based on the Generalized Multiscale Finite Element Method (GMsFEM) for a coupled system. In particular, multiscale basis functions are constructed based on some snapshot spaces for the pressure and the concentration equations and some local spectral decompositions in the snapshot spaces. The resulting approach uses a few multiscale basis functions in each coarse block (for both the pressure and the concentration) to solve the coupled system. We use the mixed framework, which allows mass conservation. Our main contributions are: (1) the development of a mass conservative GMsFEM for the coupled flow and transport; (2) the development of a robust multiscale method for convection-dominated transport problems by choosing appropriate test and trial spaces within Petrov-Galerkin mixed formulation. We present numerical results and consider several heterogeneous permeability fields. Our numerical results show that with only a few basis functions per coarse block, we can achieve a good approximation.

  7. International Conference on Multiscale Methods and Partial Differential Equations.

    Thomas Hou

    2006-12-12

    The International Conference on Multiscale Methods and Partial Differential Equations (ICMMPDE for short) was held at IPAM, UCLA on August 26-27, 2005. The conference brought together researchers, students and practitioners with interest in the theoretical, computational and practical aspects of multiscale problems and related partial differential equations. The conference provided a forum to exchange and stimulate new ideas from different disciplines, and to formulate new challenging multiscale problems that will have impact in applications.

  8. Residual-driven online generalized multiscale finite element methods

    Chung, Eric T.; Efendiev, Yalchin R.; Leung, Wing Tat

    2015-01-01

    In the paper, theoretical and numerical results are presented. Our numerical results show that if the offline space is sufficiently large (in terms of the dimension) such that the coarse space contains all multiscale spectral basis functions that correspond to small eigenvalues, then the error reduction by adding online multiscale basis function is independent of the contrast. We discuss various ways computing online multiscale basis functions which include a use of small dimensional offline spaces.

  9. EquiMar

    Johnstone, C. M.; McCombes, T.; Bahaj, A. S.

    2011-01-01

    the performance evaluation of such systems in order to address this deficiency. This paper reports the development of a set of ‘Best Practices’ within the ECFPVII EquiMar project to be adopted for the performance quantification of wave and tidal energy converters as they evolve from an engineering concept......At the present time there are no approved standards or recognised best practices being implemented for the performance appraisal and benchmarking of wave and tidal energy converters. As such, this develops considerable misunderstanding between device developers, testing centres, investors....../ financiers etc when attempting to quantify the performance of a device since it makes it very difficult to reference and benchmark the performance of a marine energy converter. The EC Framework Programme VII EquiMar project has set out to develop a suite of Best Practices to be adopted when undertaking...

  10. The politics of Mars

    Schmitt, Harrison H.

    1986-01-01

    A discussion is presented comparing past and present major accomplishments of the U.S. and the Soviet Union in space. It concludes that the Soviets are presently well ahead of the U.S. in several specific aspects of space accomplishment and speculates that the Soviet strategy is directed towards sending a man to the vicinity of Mars by the end of this century. A major successful multinational space endeavor, INTELSAT, is reviewed and it is suggested that the manned exploration of Mars offers a unique opportunity for another such major international cooperative effort. The current attitude of U.S. leadership and the general public is assessed as uniformed or ambivalent about the perceived threat of Soviet dominance in space.

  11. Fossil life on Mars

    Walter, M. R.

    1989-01-01

    Three major problems beset paleontologists searching for morphological evidence of life on early Earth: selecting a prospective site; finding biogenic structures; and distinguishing biogenic from abiogenic structures. The same problems arise on Mars. Terrestrial experience suggests that, with the techniques that can be employed remotely, ancient springs, including hot springs, are more prospective than lake deposits. If, on the other hand, the search is for chemical evidence, the strategy can be very different, and lake deposits are attractive targets. Lakes and springs frequenly occur in close proximity, and therefore a strategy that combines the two would seem to maximize the chance of success. The strategy for a search for stromatolite on Mars is discussed.

  12. Multiscale geomorphometric modeling of Mercury

    Florinsky, I. V.

    2018-02-01

    Topography is one of the key characteristics of a planetary body. Geomorphometry deals with quantitative modeling and analysis of the topographic surface and relationships between topography and other natural components of landscapes. The surface of Mercury is systematically studied by interpretation of images acquired during the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission. However, the Mercurian surface is still little explored by methods of geomorphometry. In this paper, we evaluate the Mercury MESSENGER Global DEM MSGR_DEM_USG_SC_I_V02 - a global digital elevation model (DEM) of Mercury with the resolution of 0.015625° - as a source for geomorphometric modeling of this planet. The study was performed at three spatial scales: the global, regional (the Caloris basin), and local (the Pantheon Fossae area) ones. As the initial data, we used three DEMs of these areas with resolutions of 0.25°, 0.0625°, and 0.015625°, correspondingly. The DEMs were extracted from the MESSENGER Global DEM. From the DEMs, we derived digital models of several fundamental morphometric variables, such as: slope gradient, horizontal curvature, vertical curvature, minimal curvature, maximal curvature, catchment area, and dispersive area. The morphometric maps obtained represent peculiarities of the Mercurian topography in different ways, according to the physical and mathematical sense of a particular variable. Geomorphometric models are a rich source of information on the Mercurian surface. These data can be utilized to study evolution and internal structure of the planet, for example, to visualize and quantify regional topographic differences as well as to refine geological boundaries.

  13. Mars Express - ESA sets ambitious goals for the first European mission to Mars

    2003-05-01

    Mars has always fascinated human beings. No other planet has been visited so many times by spacecraft. And still, it has not been easy to unveil its secrets. Martian mysteries seem to have increased in quantity and complexity with every mission. When the first spacecraft were sent - the Mariner series in 1960s - the public was expecting an Earth ‘twin’, a green, inhabited planet full of oceans. Mariner shattered this dream by showing a barren surface. This was followed by the Viking probes which searched for life unsuccessfully in 1976. Mars appeared dry, cold and uninhabited: the Earth’s opposite. Now, two decades later, modern spacecraft have changed that view, but they have also returned more questions. Current data show that Mars was probably much warmer in the past. Scientists now think that Mars had oceans, so it could have been a suitable place for life in the past. “We do not know what happened to the planet in the past. Which process turned Mars into the dry, cold world we see today?” says Agustin Chicarro, ESA’s Mars Express project scientist. “With Mars Express, we will find out. Above all, we aim to obtain a complete global view of the planet - its history, its geology, how it has evolved. Real planetology!” Mars Express will reach the Red Planet by the end of December 2003, after a trip of just over six months. Six days before injection into its final orbit, Mars Express will eject the lander, Beagle 2, named after the ship on which Charles Darwin found inspiration to formulate his theory of evolution. The Mars Express orbiter will observe the planet and its atmosphere from a near-polar orbit, and will remain in operation for at least a whole Martian year (687 Earth days). Beagle 2 will land in an equatorial region that was probably flooded in the past, and where traces of life may have been preserved. The Mars Express orbiter carries seven advanced experiments, in addition to the Beagle 2 lander. The orbiter’s instruments have been

  14. Sustainable Mars Sample Return

    Alston, Christie; Hancock, Sean; Laub, Joshua; Perry, Christopher; Ash, Robert

    2011-01-01

    The proposed Mars sample return mission will be completed using natural Martian resources for the majority of its operations. The system uses the following technologies: In-Situ Propellant Production (ISPP), a methane-oxygen propelled Mars Ascent Vehicle (MAV), a carbon dioxide powered hopper, and a hydrogen fueled balloon system (large balloons and small weather balloons). The ISPP system will produce the hydrogen, methane, and oxygen using a Sabatier reactor. a water electrolysis cell, water extracted from the Martian surface, and carbon dioxide extracted from the Martian atmosphere. Indigenous hydrogen will fuel the balloon systems and locally-derived methane and oxygen will fuel the MAV for the return of a 50 kg sample to Earth. The ISPP system will have a production cycle of 800 days and the estimated overall mission length is 1355 days from Earth departure to return to low Earth orbit. Combining these advanced technologies will enable the proposed sample return mission to be executed with reduced initial launch mass and thus be more cost efficient. The successful completion of this mission will serve as the next step in the advancement of Mars exploration technology.

  15. Multiscale Modeling of Point and Line Defects in Cubic Lattices

    Chung, P. W; Clayton, J. D

    2007-01-01

    .... This multiscale theory explicitly captures heterogeneity in microscopic atomic motion in crystalline materials, attributed, for example, to the presence of various point and line lattice defects...

  16. Towards practical multiscale approach for analysis of reinforced concrete structures

    Moyeda, Arturo; Fish, Jacob

    2017-12-01

    We present a novel multiscale approach for analysis of reinforced concrete structural elements that overcomes two major hurdles in utilization of multiscale technologies in practice: (1) coupling between material and structural scales due to consideration of large representative volume elements (RVE), and (2) computational complexity of solving complex nonlinear multiscale problems. The former is accomplished using a variant of computational continua framework that accounts for sizeable reinforced concrete RVEs by adjusting the location of quadrature points. The latter is accomplished by means of reduced order homogenization customized for structural elements. The proposed multiscale approach has been verified against direct numerical simulations and validated against experimental results.

  17. Multiscale Cues Drive Collective Cell Migration

    Nam, Ki-Hwan; Kim, Peter; Wood, David K.; Kwon, Sunghoon; Provenzano, Paolo P.; Kim, Deok-Ho

    2016-07-01

    To investigate complex biophysical relationships driving directed cell migration, we developed a biomimetic platform that allows perturbation of microscale geometric constraints with concomitant nanoscale contact guidance architectures. This permits us to elucidate the influence, and parse out the relative contribution, of multiscale features, and define how these physical inputs are jointly processed with oncogenic signaling. We demonstrate that collective cell migration is profoundly enhanced by the addition of contract guidance cues when not otherwise constrained. However, while nanoscale cues promoted migration in all cases, microscale directed migration cues are dominant as the geometric constraint narrows, a behavior that is well explained by stochastic diffusion anisotropy modeling. Further, oncogene activation (i.e. mutant PIK3CA) resulted in profoundly increased migration where extracellular multiscale directed migration cues and intrinsic signaling synergistically conspire to greatly outperform normal cells or any extracellular guidance cues in isolation.

  18. Multiscale Study of Currents Affected by Topography

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Multiscale Study of Currents Affected by Topography ...the effects of topography on the ocean general and regional circulation with a focus on the wide range of scales of interactions. The small-scale...details of the topography and the waves, eddies, drag, and turbulence it generates (at spatial scales ranging from meters to mesoscale) interact in the

  19. A multiscale approach to Brownian motors

    Pavliotis, G.A.

    2005-01-01

    The problem of Brownian motion in a periodic potential, under the influence of external forcing, which is either random or periodic in time, is studied in this Letter. Multiscale techniques are used to derive general formulae for the steady state particle current and the effective diffusion tensor. These formulae are then applied to calculate the effective diffusion coefficient for a Brownian particle in a periodic potential driven simultaneously by additive Gaussian white and colored noise. Our theoretical findings are supported by numerical simulations

  20. Multiscale modeling of mucosal immune responses

    2015-01-01

    Computational modeling techniques are playing increasingly important roles in advancing a systems-level mechanistic understanding of biological processes. Computer simulations guide and underpin experimental and clinical efforts. This study presents ENteric Immune Simulator (ENISI), a multiscale modeling tool for modeling the mucosal immune responses. ENISI's modeling environment can simulate in silico experiments from molecular signaling pathways to tissue level events such as tissue lesion formation. ENISI's architecture integrates multiple modeling technologies including ABM (agent-based modeling), ODE (ordinary differential equations), SDE (stochastic modeling equations), and PDE (partial differential equations). This paper focuses on the implementation and developmental challenges of ENISI. A multiscale model of mucosal immune responses during colonic inflammation, including CD4+ T cell differentiation and tissue level cell-cell interactions was developed to illustrate the capabilities, power and scope of ENISI MSM. Background Computational techniques are becoming increasingly powerful and modeling tools for biological systems are of greater needs. Biological systems are inherently multiscale, from molecules to tissues and from nano-seconds to a lifespan of several years or decades. ENISI MSM integrates multiple modeling technologies to understand immunological processes from signaling pathways within cells to lesion formation at the tissue level. This paper examines and summarizes the technical details of ENISI, from its initial version to its latest cutting-edge implementation. Implementation Object-oriented programming approach is adopted to develop a suite of tools based on ENISI. Multiple modeling technologies are integrated to visualize tissues, cells as well as proteins; furthermore, performance matching between the scales is addressed. Conclusion We used ENISI MSM for developing predictive multiscale models of the mucosal immune system during gut

  1. Multiscale modeling of mucosal immune responses.

    Mei, Yongguo; Abedi, Vida; Carbo, Adria; Zhang, Xiaoying; Lu, Pinyi; Philipson, Casandra; Hontecillas, Raquel; Hoops, Stefan; Liles, Nathan; Bassaganya-Riera, Josep

    2015-01-01

    Computational techniques are becoming increasingly powerful and modeling tools for biological systems are of greater needs. Biological systems are inherently multiscale, from molecules to tissues and from nano-seconds to a lifespan of several years or decades. ENISI MSM integrates multiple modeling technologies to understand immunological processes from signaling pathways within cells to lesion formation at the tissue level. This paper examines and summarizes the technical details of ENISI, from its initial version to its latest cutting-edge implementation. Object-oriented programming approach is adopted to develop a suite of tools based on ENISI. Multiple modeling technologies are integrated to visualize tissues, cells as well as proteins; furthermore, performance matching between the scales is addressed. We used ENISI MSM for developing predictive multiscale models of the mucosal immune system during gut inflammation. Our modeling predictions dissect the mechanisms by which effector CD4+ T cell responses contribute to tissue damage in the gut mucosa following immune dysregulation.Computational modeling techniques are playing increasingly important roles in advancing a systems-level mechanistic understanding of biological processes. Computer simulations guide and underpin experimental and clinical efforts. This study presents ENteric Immune Simulator (ENISI), a multiscale modeling tool for modeling the mucosal immune responses. ENISI's modeling environment can simulate in silico experiments from molecular signaling pathways to tissue level events such as tissue lesion formation. ENISI's architecture integrates multiple modeling technologies including ABM (agent-based modeling), ODE (ordinary differential equations), SDE (stochastic modeling equations), and PDE (partial differential equations). This paper focuses on the implementation and developmental challenges of ENISI. A multiscale model of mucosal immune responses during colonic inflammation, including CD4+ T

  2. Multi-scale Regions from Edge Fragments

    Kazmi, Wajahat; Andersen, Hans Jørgen

    2014-01-01

    In this article we introduce a novel method for detecting multi-scale salient regions around edges using a graph based image compression algorithm. Images are recursively decomposed into triangles arranged into a binary tree using linear interpolation. The entropy of any local region of the image......), their performance is comparable to SIFT (Lowe, 2004).We also show that when they are used together with MSERs (Matas et al., 2002), the performance of MSERs is boosted....

  3. Understanding "Inclusive Growth": Advancing the global agenda ...

    2013-03-27

    Mar 27, 2013 ... Increasingly, the concept of "inclusive growth," where the benefits of economic growth are ... Growth is less likely to be sustainable with high and/or growing inequalities, and ... A global vision for small business in Egypt.

  4. Mars Aqueous Processing System

    Berggren, Mark; Wilson, Cherie; Carrera, Stacy; Rose, Heather; Muscatello, Anthony; Kilgore, James; Zubrin, Robert

    2012-01-01

    The goal of the Mars Aqueous Processing System (MAPS) is to establish a flexible process that generates multiple products that are useful for human habitation. Selectively extracting useful components into an aqueous solution, and then sequentially recovering individual constituents, can obtain a suite of refined or semi-refined products. Similarities in the bulk composition (although not necessarily of the mineralogy) of Martian and Lunar soils potentially make MAPS widely applicable. Similar process steps can be conducted on both Mars and Lunar soils while tailoring the reaction extents and recoveries to the specifics of each location. The MAPS closed-loop process selectively extracts, and then recovers, constituents from soils using acids and bases. The emphasis on Mars involves the production of useful materials such as iron, silica, alumina, magnesia, and concrete with recovery of oxygen as a byproduct. On the Moon, similar chemistry is applied with emphasis on oxygen production. This innovation has been demonstrated to produce high-grade materials, such as metallic iron, aluminum oxide, magnesium oxide, and calcium oxide, from lunar and Martian soil simulants. Most of the target products exhibited purities of 80 to 90 percent or more, allowing direct use for many potential applications. Up to one-fourth of the feed soil mass was converted to metal, metal oxide, and oxygen products. The soil residue contained elevated silica content, allowing for potential additional refining and extraction for recovery of materials needed for photovoltaic, semiconductor, and glass applications. A high-grade iron oxide concentrate derived from lunar soil simulant was used to produce a metallic iron component using a novel, combined hydrogen reduction/metal sintering technique. The part was subsequently machined and found to be structurally sound. The behavior of the lunar-simulant-derived iron product was very similar to that produced using the same methods on a Michigan iron

  5. Secular Climate Change on Mars: An Update Using One Mars Year of MSL Pressure Data

    Haberle, R. M.; Gomez-Elvira, J.; de la Torre Juarez, M.; Harri, A-M.; Hollingsworth, J. L.; Kahanpaa, H.; Kahre, M. A.; Lemmon, M.; Martin-Torres, F. J.; Mischna, M.; hide

    2014-01-01

    The South Polar Residual Cap (SPRC) on Mars is an icy reservoir of CO2. If all the CO2 trapped in the SPRC were released to the atmosphere the mean annual global surface pressure would rise by approximately 20 Pa. Repeated MOC and HiRISE imaging of scarp retreat within the SPRC led to suggestions that the SPRC is losing mass. Estimates for the loss rate vary between 0. 5 Pa per Mars Decade to 13 Pa per Mars Decade. Assuming 80% of this loss goes directly into the atmosphere, an estimate based on some modeling (Haberle and Kahre, 2010), and that the loss is monotonic, the global annual mean surface pressure should have increased between approximately 1-20 Pa since the Viking mission (approximately 20 Mars years ago). Surface pressure measurements by the Phoenix Lander only 2.5 Mars years ago were found to be consistent with these loss rates. Last year at this meeting we compared surface pressure data from the MSL mission through sol 360 with that from Viking Lander 2 (VL-2) for the same period to determine if the trend continues. The results were ambiguous. This year we have a full Mars year of MSL data to work with. Using the Ames GCM to compensate for dynamics and environmental differences, our analysis suggests that the mean annual pressure has decreased by approximately 8 Pa since Viking. This result implies that the SPRC has gained (not lost) mass since Viking. However, the estimated uncertainties in our analysis are easily at the 10 Pa level and possibly higher. Chief among these are the hydrostatic adjustment of surface pressure from grid point elevations to actual elevations and the simulated regional environmental conditions at the lander sites. For these reasons, the most reasonable conclusion is that there is no significant difference in the size of the atmosphere between now and Viking. This implies, but does not demand, that the mass of the SPRC has not changed since Viking. Of course, year-to-year variations are possible as implied by the Phoenix data

  6. Curiosity at Gale Crater, Mars: Characterization and Analysis of the Rocknest Sand Shadow

    Blake, D. F.; Morris, R. V.; Kocurek, G.; Morrison, S. M.; Downs, R. T.; Bish, D.; Ming, D. W.; Edgett, K. S.; Rubin, D.; Goetz, W.; Madsen, M. B.; Sullivan, R.; Gellert, R.; Campbell, I.; Treiman, A. H.; McLennan, S. M.; Yen, A. S.; Grotzinger, J.; Vaniman, D. T.; Chipera, S. J.; Achilles, C. N.; Rampe, E. B.; Sumner, D.; Meslin, P.-Y.; Maurice, S.; Forni, O.; Gasnault, O.; Fisk, M.; Schmidt, M.; Mahaffy, P.; Leshin, L. A.; Glavin, D.; Steele, A.; Freissinet, C.; Navarro-González, R.; Yingst, R. A.; Kah, L. C.; Bridges, N.; Lewis, K. W.; Bristow, T. F.; Farmer, J. D.; Crisp, J. A.; Stolper, E. M.; Des Marais, D. J.; Sarrazin, P.; Agard, Christophe; Alves Verdasca, José Alexandre; Anderson, Robert; Anderson, Ryan; Archer, Doug; Armiens-Aparicio, Carlos; Arvidson, Ray; Atlaskin, Evgeny; Atreya, Sushil; Aubrey, Andrew; Baker, Burt; Baker, Michael; Balic-Zunic, Tonci; Baratoux, David; Baroukh, Julien; Barraclough, Bruce; Bean, Keri; Beegle, Luther; Behar, Alberto; Bell, James; Bender, Steve; Benna, Mehdi; Bentz, Jennifer; Berger, Gilles; Berger, Jeff; Berman, Daniel; Blanco Avalos, Juan Jose; Blaney, Diana; Blank, Jen; Blau, Hannah; Bleacher, Lora; Boehm, Eckart; Botta, Oliver; Böttcher, Stephan; Boucher, Thomas; Bower, Hannah; Boyd, Nick; Boynton, Bill; Breves, Elly; Bridges, John; Brinckerhoff, William; Brinza, David; Brunet, Claude; Brunner, Anna; Brunner, Will; Buch, Arnaud; Bullock, Mark; Burmeister, Sönke; Cabane, Michel; Calef, Fred; Cameron, James; Cantor, Bruce; Caplinger, Michael; Rodríguez, Javier Caride; Carmosino, Marco; Blázquez, Isaías Carrasco; Charpentier, Antoine; Choi, David; Clark, Benton; Clegg, Sam; Cleghorn, Timothy; Cloutis, Ed; Cody, George; Coll, Patrice; Conrad, Pamela; Coscia, David; Cousin, Agnès; Cremers, David; Cros, Alain; Cucinotta, Frank; d'Uston, Claude; Davis, Scott; Day, Mackenzie; Juarez, Manuel de la Torre; DeFlores, Lauren; DeLapp, Dorothea; DeMarines, Julia; Dietrich, William; Dingler, Robert; Donny, Christophe; Drake, Darrell; Dromart, Gilles; Dupont, Audrey; Duston, Brian; Dworkin, Jason; Dyar, M. Darby; Edgar, Lauren; Edwards, Christopher; Edwards, Laurence; Ehlmann, Bethany; Ehresmann, Bent; Eigenbrode, Jen; Elliott, Beverley; Elliott, Harvey; Ewing, Ryan; Fabre, Cécile; Fairén, Alberto; Farley, Ken; Fassett, Caleb; Favot, Laurent; Fay, Donald; Fedosov, Fedor; Feldman, Jason; Feldman, Sabrina; Fitzgibbon, Mike; Flesch, Greg; Floyd, Melissa; Flückiger, Lorenzo; Fraeman, Abby; Francis, Raymond; François, Pascaline; Franz, Heather; French, Katherine Louise; Frydenvang, Jens; Gaboriaud, Alain; Gailhanou, Marc; Garvin, James; Geffroy, Claude; Genzer, Maria; Godber, Austin; Goesmann, Fred; Golovin, Dmitry; Gómez, Felipe Gómez; Gómez-Elvira, Javier; Gondet, Brigitte; Gordon, Suzanne; Gorevan, Stephen; Grant, John; Griffes, Jennifer; Grinspoon, David; Guillemot, Philippe; Guo, Jingnan; Gupta, Sanjeev; Guzewich, Scott; Haberle, Robert; Halleaux, Douglas; Hallet, Bernard; Hamilton, Vicky; Hardgrove, Craig; Harker, David; Harpold, Daniel; Harri, Ari-Matti; Harshman, Karl; Hassler, Donald; Haukka, Harri; Hayes, Alex; Herkenhoff, Ken; Herrera, Paul; Hettrich, Sebastian; Heydari, Ezat; Hipkin, Victoria; Hoehler, Tori; Hollingsworth, Jeff; Hudgins, Judy; Huntress, Wesley; Hurowitz, Joel; Hviid, Stubbe; Iagnemma, Karl; Indyk, Steve; Israël, Guy; Jackson, Ryan; Jacob, Samantha; Jakosky, Bruce; Jensen, Elsa; Jensen, Jaqueline Kløvgaard; Johnson, Jeffrey; Johnson, Micah; Johnstone, Steve; Jones, Andrea; Jones, John; Joseph, Jonathan; Jun, Insoo; Kahanpää, Henrik; Kahre, Melinda; Karpushkina, Natalya; Kasprzak, Wayne; Kauhanen, Janne; Keely, Leslie; Kemppinen, Osku; Keymeulen, Didier; Kim, Myung-Hee; Kinch, Kjartan; King, Penny; Kirkland, Laurel; Koefoed, Asmus; Köhler, Jan; Kortmann, Onno; Kozyrev, Alexander; Krezoski, Jill; Krysak, Daniel; Kuzmin, Ruslan; Lacour, Jean Luc; Lafaille, Vivian; Langevin, Yves; Lanza, Nina; Lasue, Jeremie; Le Mouélic, Stéphane; Lee, Ella Mae; Lee, Qiu-Mei; Lees, David; Lefavor, Matthew; Lemmon, Mark; Lepinette Malvitte, Alain; Léveillé, Richard; Lewin-Carpintier, Éric; Li, Shuai; Lipkaman, Leslie; Little, Cynthia; Litvak, Maxim; Lorigny, Eric; Lugmair, Guenter; Lundberg, Angela; Lyness, Eric; Maki, Justin; Malakhov, Alexey; Malespin, Charles; Malin, Michael; Mangold, Nicolas; Manning, Heidi; Marchand, Geneviève; Marín Jiménez, Mercedes; Martín García, César; Martin, Dave; Martin, Mildred; Martínez-Frías, Jesús; Martín-Soler, Javier; Martín-Torres, F. Javier; Mauchien, Patrick; McAdam, Amy; McCartney, Elaina; McConnochie, Timothy; McCullough, Emily; McEwan, Ian; McKay, Christopher; McNair, Sean; Melikechi, Noureddine; Meyer, Michael; Mezzacappa, Alissa; Miller, Hayden; Miller, Kristen; Milliken, Ralph; Minitti, Michelle; Mischna, Michael; Mitrofanov, Igor; Moersch, Jeff; Mokrousov, Maxim; Molina Jurado, Antonio; Moores, John; Mora-Sotomayor, Luis; Morookian, John Michael; Mueller-Mellin, Reinhold; Muller, Jan-Peter; Muñoz Caro, Guillermo; Nachon, Marion; Navarro López, Sara; Nealson, Kenneth; Nefian, Ara; Nelson, Tony; Newcombe, Megan; Newman, Claire; Newsom, Horton; Nikiforov, Sergey; Niles, Paul; Nixon, Brian; Dobrea, Eldar Noe; Nolan, Thomas; Oehler, Dorothy; Ollila, Ann; Olson, Timothy; Owen, Tobias; Pablo, Hernández; Paillet, Alexis; Pallier, Etienne; Palucis, Marisa; Parker, Timothy; Parot, Yann; Patel, Kiran; Paton, Mark; Paulsen, Gale; Pavlov, Alex; Pavri, Betina; Peinado-González, Verónica; Pepin, Robert; Peret, Laurent; Perez, Rene; Perrett, Glynis; Peterson, Joe; Pilorget, Cedric; Pinet, Patrick; Pla-García, Jorge; Plante, Ianik; Poitrasson, Franck; Polkko, Jouni; Popa, Radu; Posiolova, Liliya; Pradler, Irina; Prats, Benito; Prokhorov, Vasily; Purdy, Sharon Wilson; Raaen, Eric; Radziemski, Leon; Rafkin, Scot; Ramos, Miguel; Raulin, François; Ravine, Michael; Reitz, Günther; Rennó, Nilton; Rice, Melissa; Richardson, Mark; Robert, François; Rodriguez Manfredi, José Antonio; Romeral-Planelló, Julio J.; Rowland, Scott; Saccoccio, Muriel; Salamon, Andrew; Sandoval, Jennifer; Sanin, Anton; Sans Fuentes, Sara Alejandra; Saper, Lee; Sautter, Violaine; Savijärvi, Hannu; Schieber, Juergen; Schmidt, Walter; Scholes, Daniel; Schoppers, Marcel; Schröder, Susanne; Sebastian Martinez, Eduardo; Sengstacken, Aaron; Shterts, Ruslan; Siebach, Kirsten; Siili, Tero; Simmonds, Jeff; Sirven, Jean-Baptiste; Slavney, Susie; Sletten, Ronald; Smith, Michael; Sobrón Sánchez, Pablo; Spanovich, Nicole; Spray, John; Squyres, Steven; Stack, Katie; Stalport, Fabien; Stein, Thomas; Stern, Jennifer; Stewart, Noel; Stipp, Susan Louise Svane; Stoiber, Kevin; Sucharski, Bob; Summons, Roger; Sun, Vivian; Supulver, Kimberley; Sutter, Brad; Szopa, Cyril; Tate, Christopher; Teinturier, Samuel; ten Kate, Inge Loes; Thomas, Peter; Thompson, Lucy; Tokar, Robert; Toplis, Mike; Torres Redondo, Josefina; Trainer, Melissa; Tretyakov, Vladislav; Urqui-O'Callaghan, Roser; Van Beek, Jason; Van Beek, Tessa; VanBommel, Scott; Varenikov, Alexey; Vasavada, Ashwin; Vasconcelos, Paulo; Vicenzi, Edward; Vostrukhin, Andrey; Voytek, Mary; Wadhwa, Meenakshi; Ward, Jennifer; Webster, Chris; Weigle, Eddie; Wellington, Danika; Westall, Frances; Wiens, Roger Craig; Wilhelm, Mary Beth; Williams, Amy; Williams, Joshua; Williams, Rebecca; Williams, Richard B.; Wilson, Mike; Wimmer-Schweingruber, Robert; Wolff, Mike; Wong, Mike; Wray, James; Wu, Megan; Yana, Charles; Zeitlin, Cary; Zimdar, Robert; Zorzano Mier, María-Paz

    2013-09-01

    The Rocknest aeolian deposit is similar to aeolian features analyzed by the Mars Exploration Rovers (MERs) Spirit and Opportunity. The fraction of sand Mars instrument and of the fine-grained nanophase oxide component first described from basaltic soils analyzed by MERs. The similarity between soils and aeolian materials analyzed at Gusev Crater, Meridiani Planum, and Gale Crater implies locally sourced, globally similar basaltic materials or globally and regionally sourced basaltic components deposited locally at all three locations.

  7. Engineering Digestion: Multiscale Processes of Food Digestion.

    Bornhorst, Gail M; Gouseti, Ourania; Wickham, Martin S J; Bakalis, Serafim

    2016-03-01

    Food digestion is a complex, multiscale process that has recently become of interest to the food industry due to the developing links between food and health or disease. Food digestion can be studied by using either in vitro or in vivo models, each having certain advantages or disadvantages. The recent interest in food digestion has resulted in a large number of studies in this area, yet few have provided an in-depth, quantitative description of digestion processes. To provide a framework to develop these quantitative comparisons, a summary is given here between digestion processes and parallel unit operations in the food and chemical industry. Characterization parameters and phenomena are suggested for each step of digestion. In addition to the quantitative characterization of digestion processes, the multiscale aspect of digestion must also be considered. In both food systems and the gastrointestinal tract, multiple length scales are involved in food breakdown, mixing, absorption. These different length scales influence digestion processes independently as well as through interrelated mechanisms. To facilitate optimized development of functional food products, a multiscale, engineering approach may be taken to describe food digestion processes. A framework for this approach is described in this review, as well as examples that demonstrate the importance of process characterization as well as the multiple, interrelated length scales in the digestion process. © 2016 Institute of Food Technologists®

  8. Adaptive multiscale processing for contrast enhancement

    Laine, Andrew F.; Song, Shuwu; Fan, Jian; Huda, Walter; Honeyman, Janice C.; Steinbach, Barbara G.

    1993-07-01

    This paper introduces a novel approach for accomplishing mammographic feature analysis through overcomplete multiresolution representations. We show that efficient representations may be identified from digital mammograms within a continuum of scale space and used to enhance features of importance to mammography. Choosing analyzing functions that are well localized in both space and frequency, results in a powerful methodology for image analysis. We describe methods of contrast enhancement based on two overcomplete (redundant) multiscale representations: (1) Dyadic wavelet transform (2) (phi) -transform. Mammograms are reconstructed from transform coefficients modified at one or more levels by non-linear, logarithmic and constant scale-space weight functions. Multiscale edges identified within distinct levels of transform space provide a local support for enhancement throughout each decomposition. We demonstrate that features extracted from wavelet spaces can provide an adaptive mechanism for accomplishing local contrast enhancement. We suggest that multiscale detection and local enhancement of singularities may be effectively employed for the visualization of breast pathology without excessive noise amplification.

  9. Acoustics of multiscale sorptive porous materials

    Venegas, R.; Boutin, C.; Umnova, O.

    2017-08-01

    This paper investigates sound propagation in multiscale rigid-frame porous materials that support mass transfer processes, such as sorption and different types of diffusion, in addition to the usual visco-thermo-inertial interactions. The two-scale asymptotic method of homogenization for periodic media is successively used to derive the macroscopic equations describing sound propagation through the material. This allowed us to conclude that the macroscopic mass balance is significantly modified by sorption, inter-scale (micro- to/from nanopore scales) mass diffusion, and inter-scale (pore to/from micro- and nanopore scales) pressure diffusion. This modification is accounted for by the dynamic compressibility of the effective saturating fluid that presents atypical properties that lead to slower speed of sound and higher sound attenuation, particularly at low frequencies. In contrast, it is shown that the physical processes occurring at the micro-nano-scale do not affect the macroscopic fluid flow through the material. The developed theory is exemplified by introducing an analytical model for multiscale sorptive granular materials, which is experimentally validated by comparing its predictions with acoustic measurements on granular activated carbons. Furthermore, we provide empirical evidence supporting an alternative method for measuring sorption and mass diffusion properties of multiscale sorptive materials using sound waves.

  10. Multiscale Phase Inversion of Seismic Data

    Fu, Lei

    2017-12-02

    We present a scheme for multiscale phase inversion (MPI) of seismic data that is less sensitive to the unmodeled physics of wave propagation and a poor starting model than standard full waveform inversion (FWI). To avoid cycle-skipping, the multiscale strategy temporally integrates the traces several times, i.e. high-order integration, to produce low-boost seismograms that are used as input data for the initial iterations of MPI. As the iterations proceed, higher frequencies in the data are boosted by using integrated traces of lower order as the input data. The input data are also filtered into different narrow frequency bands for the MPI implementation. At low frequencies, we show that MPI with windowed reflections approximates wave equation inversion of the reflection traveltimes, except no traveltime picking is needed. Numerical results with synthetic acoustic data show that MPI is more robust than conventional multiscale FWI when the initial model is far from the true model. Results from synthetic viscoacoustic and elastic data show that MPI is less sensitive than FWI to some of the unmodeled physics. Inversion of marine data shows that MPI is more robust and produces modestly more accurate results than FWI for this data set.

  11. Electrical power systems for Mars

    Giudici, Robert J.

    1986-01-01

    Electrical power system options for Mars Manned Modules and Mars Surface Bases were evaluated for both near-term and advanced performance potential. The power system options investigated for the Mission Modules include photovoltaics, solar thermal, nuclear reactor, and isotope power systems. Options discussed for Mars Bases include the above options with the addition of a brief discussion of open loop energy conversion of Mars resources, including utilization of wind, subsurface thermal gradients, and super oxides. Electrical power requirements for Mission Modules were estimated for three basic approaches: as a function of crew size; as a function of electric propulsion; and as a function of transmission of power from an orbiter to the surface of Mars via laser or radio frequency. Mars Base power requirements were assumed to be determined by production facilities that make resources available for follow-on missions leading to the establishment of a permanently manned Base. Requirements include the production of buffer gas and propellant production plants.

  12. Guidelines for 2007 MARS exercise

    HR Department

    2007-01-01

    Following the introduction of the new Merit Appraisal and Recognition Scheme (MARS), full details of the scheme are now available via the HR Department's homepage or directly on the Department's MARS web page: in English: http://humanresources.web.cern.ch/HumanResources/internal/personnel/pmd/cr/MARS.asp or French: http://humanresources.web.cern.ch/humanresources/internal/personnel/pmd/cr/mars_fr.asp You will find on this page: 'Introduction to MARS' with detailed information presented in Frequently Asked Questions; these include the MARS timetable for proposals and decisions; 'Regulations' with links to the scheme's statutory documents; 'Procedures and Forms' and 'Useful Information' with links to all the relevant documentation; these include the mandates of the Senior Staff Advisory Committee (SSAC) and the Technical Engineers and Administrative Careers Committee (TEACC). HR Department Tel. 73566

  13. Planned Products of the Mars Structure Service for the InSight Mission to Mars

    Panning, Mark P.; Lognonné, Philippe; Bruce Banerdt, W.; Garcia, Raphaël; Golombek, Matthew; Kedar, Sharon; Knapmeyer-Endrun, Brigitte; Mocquet, Antoine; Teanby, Nick A.; Tromp, Jeroen; Weber, Renee; Beucler, Eric; Blanchette-Guertin, Jean-Francois; Bozdağ, Ebru; Drilleau, Mélanie; Gudkova, Tamara; Hempel, Stefanie; Khan, Amir; Lekić, Vedran; Murdoch, Naomi; Plesa, Ana-Catalina; Rivoldini, Atillio; Schmerr, Nicholas; Ruan, Youyi; Verhoeven, Olivier; Gao, Chao; Christensen, Ulrich; Clinton, John; Dehant, Veronique; Giardini, Domenico; Mimoun, David; Thomas Pike, W.; Smrekar, Sue; Wieczorek, Mark; Knapmeyer, Martin; Wookey, James

    2017-10-01

    The InSight lander will deliver geophysical instruments to Mars in 2018, including seismometers installed directly on the surface (Seismic Experiment for Interior Structure, SEIS). Routine operations will be split into two services, the Mars Structure Service (MSS) and Marsquake Service (MQS), which will be responsible, respectively, for defining the structure models and seismicity catalogs from the mission. The MSS will deliver a series of products before the landing, during the operations, and finally to the Planetary Data System (PDS) archive. Prior to the mission, we assembled a suite of a priori models of Mars, based on estimates of bulk composition and thermal profiles. Initial models during the mission will rely on modeling surface waves and impact-generated body waves independent of prior knowledge of structure. Later modeling will include simultaneous inversion of seismic observations for source and structural parameters. We use Bayesian inversion techniques to obtain robust probability distribution functions of interior structure parameters. Shallow structure will be characterized using the hammering of the heatflow probe mole, as well as measurements of surface wave ellipticity. Crustal scale structure will be constrained by measurements of receiver function and broadband Rayleigh wave ellipticity measurements. Core interacting body wave phases should be observable above modeled martian noise levels, allowing us to constrain deep structure. Normal modes of Mars should also be observable and can be used to estimate the globally averaged 1D structure, while combination with results from the InSight radio science mission and orbital observations will allow for constraint of deeper structure.

  14. The Topography of Mars: Understanding the Surface of Mars Through the Mars Orbiter Laser Altimeter

    Derby, C. A.; Neumann, G. A.; Sakimoto, S. E.

    2001-12-01

    The Mars Orbiter Laser Altimeter has been orbiting Mars since 1997 and has measured the topography of Mars with a meter of vertical accuracy. This new information has improved our understanding of both the surface and the interior of Mars. The topographic globe and the labeled topographic map of Mars illustrate these new data in a format that can be used in a classroom setting. The map is color shaded to show differences in elevation on Mars, presenting Mars with a different perspective than traditional geological and geographic maps. Through the differences in color, students can see Mars as a three-dimensional surface and will be able to recognize features that are invisible in imagery. The accompanying lesson plans are designed for middle school science students and can be used both to teach information about Mars as a planet and Mars in comparison to Earth, fitting both the solar system unit and the Earth science unit in a middle school curriculum. The lessons are referenced to the National Benchmark standards for students in grades 6-8 and cover topics such as Mars exploration, the Mars Orbiter Laser Altimeter, resolution and powers of 10, gravity, craters, seismic waves and the interior structure of a planet, isostasy, and volcanoes. Each lesson is written in the 5 E format and includes a student content activity and an extension showing current applications of Mars and MOLA data. These activities can be found at http://ltpwww.gsfc.nasa.gov/education/resources.html. Funding for this project was provided by the Maryland Space Grant Consortium and the MOLA Science Team, Goddard Space Flight Center.

  15. Evidence of water vapor in excess of saturation in the atmosphere of Mars.

    Maltagliati, L; Montmessin, F; Fedorova, A; Korablev, O; Forget, F; Bertaux, J-L

    2011-09-30

    The vertical distribution of water vapor is key to the study of Mars' hydrological cycle. To date, it has been explored mainly through global climate models because of a lack of direct measurements. However, these models assume the absence of supersaturation in the atmosphere of Mars. Here, we report observations made using the SPICAM (Spectroscopy for the Investigation of the Characteristics of the Atmosphere of Mars) instrument onboard Mars Express that provide evidence of the frequent presence of water vapor in excess of saturation, by an amount far surpassing that encountered in Earth's atmosphere. This result contradicts the widespread assumption that atmospheric water on Mars cannot exist in a supersaturated state, directly affecting our long-term representation of water transport, accumulation, escape, and chemistry on a global scale.

  16. Mineralogical Results from the Mars Science Laboratory Rover Curiosity

    Blake, David Frederick.

    2017-01-01

    NASA's CheMin instrument, the first X-ray Diffractometer flown in space, has been operating on Mars for nearly five years. CheMin was first to establish the quantitative mineralogy of the Mars global soil (1). The instrument was next used to determine the mineralogy of a 3.7 billion year old lacustrine mudstone, a result that, together with findings from other instruments on the MSL Curiosity rover, documented the first habitable environment found on another planet (2). The mineralogy of this mudstone from an ancient playa lake was also used to derive the maximum concentration of CO2 in the early Mars atmosphere, a surprisingly low value that calls into question the current theory that CO2 greenhouse warming was responsible for the warm and wet environment of early Mars. CheMin later identified the mineral tridymite, indicative of silica-rich volcanism, in mudstones of the Murray formation on Mt. Sharp. This discovery challenges the paradigm of Mars as a basaltic planet and ushers in a new chapter of comparative terrestrial planetology (3). CheMin is now being used to systematically sample the sedimentary layers that comprise the lower strata of Mt. Sharp, a 5,000 meter sequence of sedimentary rock laid down in what was once a crater lake, characterizing isochemical sediments that through their changing mineralogy, document the oxidation and drying out of the Mars in early Hesperian time.

  17. A Method of Vector Map Multi-scale Representation Considering User Interest on Subdivision Gird

    YU Tong

    2016-12-01

    Full Text Available Compared with the traditional spatial data model and method, global subdivision grid show a great advantage in the organization and expression of massive spatial data. In view of this, a method of vector map multi-scale representation considering user interest on subdivision gird is proposed. First, the spatial interest field is built using a large number POI data to describe the spatial distribution of the user interest in geographic information. Second, spatial factor is classified and graded, and its representation scale range can be determined. Finally, different levels of subdivision surfaces are divided based on GeoSOT subdivision theory, and the corresponding relation of subdivision level and scale is established. According to the user interest of subdivision surfaces, the spatial feature can be expressed in different degree of detail. It can realize multi-scale representation of spatial data based on user interest. The experimental results show that this method can not only satisfy general-to-detail and important-to-secondary space cognitive demands of users, but also achieve better multi-scale representation effect.

  18. Improvement of Mars surface snow albedo modeling in LMD Mars GCM with SNICAR

    Singh, D.; Flanner, M.; Millour, E.

    2017-12-01

    The current version of Laboratoire de Météorologie Dynamique (LMD) Mars GCM (original-MGCM) uses annually repeating (prescribed) albedo values from the Thermal Emission Spectrometer observations. We integrate the Snow, Ice, and Aerosol Radiation (SNICAR) model with MGCM (SNICAR-MGCM) to prognostically determine H2O and CO2 ice cap albedos interactively in the model. Over snow-covered regions mean SNICAR-MGCM albedo is higher by about 0.034 than original-MGCM. Changes in albedo and surface dust content also impact the shortwave energy flux at the surface. SNICAR-MGCM model simulates a change of -1.26 W/m2 shortwave flux on a global scale. Globally, net CO2 ice deposition increases by about 4% over one Martian annual cycle as compared to original-MGCM simulations. SNICAR integration reduces the net mean global surface temperature, and the global surface pressure of Mars by about 0.87% and 2.5% respectively. Changes in albedo also show a similar distribution as dust deposition over the globe. The SNICAR-MGCM model generates albedos with higher sensitivity to surface dust content as compared to original-MGCM. For snow-covered regions, we improve the correlation between albedo and optical depth of dust from -0.91 to -0.97 with SNICAR-MGCM as compared to original-MGCM. Using new diagnostic capabilities with this model, we find that cryospheric surfaces (with dust) increase the global surface albedo of Mars by 0.022. The cryospheric effect is severely muted by dust in snow, however, which acts to decrease the planet-mean surface albedo by 0.06.

  19. Multiscale Persistent Functions for Biomolecular Structure Characterization

    Xia, Kelin [Nanyang Technological University (Singapore). Division of Mathematical Sciences, School of Physical, Mathematical Sciences and School of Biological Sciences; Li, Zhiming [Central China Normal University, Wuhan (China). Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics; Mu, Lin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Computer Science and Mathematics Division

    2017-11-02

    Here in this paper, we introduce multiscale persistent functions for biomolecular structure characterization. The essential idea is to combine our multiscale rigidity functions (MRFs) with persistent homology analysis, so as to construct a series of multiscale persistent functions, particularly multiscale persistent entropies, for structure characterization. To clarify the fundamental idea of our method, the multiscale persistent entropy (MPE) model is discussed in great detail. Mathematically, unlike the previous persistent entropy (Chintakunta et al. in Pattern Recognit 48(2):391–401, 2015; Merelli et al. in Entropy 17(10):6872–6892, 2015; Rucco et al. in: Proceedings of ECCS 2014, Springer, pp 117–128, 2016), a special resolution parameter is incorporated into our model. Various scales can be achieved by tuning its value. Physically, our MPE can be used in conformational entropy evaluation. More specifically, it is found that our method incorporates in it a natural classification scheme. This is achieved through a density filtration of an MRF built from angular distributions. To further validate our model, a systematical comparison with the traditional entropy evaluation model is done. Additionally, it is found that our model is able to preserve the intrinsic topological features of biomolecular data much better than traditional approaches, particularly for resolutions in the intermediate range. Moreover, by comparing with traditional entropies from various grid sizes, bond angle-based methods and a persistent homology-based support vector machine method (Cang et al. in Mol Based Math Biol 3:140–162, 2015), we find that our MPE method gives the best results in terms of average true positive rate in a classic protein structure classification test. More interestingly, all-alpha and all-beta protein classes can be clearly separated from each other with zero error only in our model. Finally, a special protein structure index (PSI) is proposed, for the first

  20. Numerical Study of Thermal Hydraulics for Secondary side of Steam Generator by CUPID/MARS Coupled Simulation

    Lee, Jae Ryong; Yoon, Han Young [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    As a thermal-hydraulic behavior in the secondary side of steam generator such as two-phase boiling flow, flow-induce vibration of U-tubes is quite complicated, the importance to numerically investigate the flow behavior has been arisen. Recently, multi-scale analyses have been developed to take into account the primary side as well. In this study, the coupled CUPID and MARS code was used for the simulation of boiler side of the PWR steam generator. Calculation results are compared with the existing code quantitatively. Coupled CUPID/MARS code was applied for the simulation of the steam generator. The primary side of the steam generator and other RCS was simulated by MARS and the secondary side was calculated by CUPID with porous media approach.

  1. SegAN: Adversarial Network with Multi-scale L1 Loss for Medical Image Segmentation.

    Xue, Yuan; Xu, Tao; Zhang, Han; Long, L Rodney; Huang, Xiaolei

    2018-05-03

    Inspired by classic Generative Adversarial Networks (GANs), we propose a novel end-to-end adversarial neural network, called SegAN, for the task of medical image segmentation. Since image segmentation requires dense, pixel-level labeling, the single scalar real/fake output of a classic GAN's discriminator may be ineffective in producing stable and sufficient gradient feedback to the networks. Instead, we use a fully convolutional neural network as the segmentor to generate segmentation label maps, and propose a novel adversarial critic network with a multi-scale L 1 loss function to force the critic and segmentor to learn both global and local features that capture long- and short-range spatial relationships between pixels. In our SegAN framework, the segmentor and critic networks are trained in an alternating fashion in a min-max game: The critic is trained by maximizing a multi-scale loss function, while the segmentor is trained with only gradients passed along by the critic, with the aim to minimize the multi-scale loss function. We show that such a SegAN framework is more effective and stable for the segmentation task, and it leads to better performance than the state-of-the-art U-net segmentation method. We tested our SegAN method using datasets from the MICCAI BRATS brain tumor segmentation challenge. Extensive experimental results demonstrate the effectiveness of the proposed SegAN with multi-scale loss: on BRATS 2013 SegAN gives performance comparable to the state-of-the-art for whole tumor and tumor core segmentation while achieves better precision and sensitivity for Gd-enhance tumor core segmentation; on BRATS 2015 SegAN achieves better performance than the state-of-the-art in both dice score and precision.

  2. Updating sea spray aerosol emissions in the Community Multiscale Air Quality (CMAQ) model version 5.0.2

    Gantt, B.; Kelly, J. T.; Bash, J. O.

    2015-01-01

    Sea spray aerosols (SSAs) impact the particle mass concentration and gas-particle partitioning in coastal environments, with implications for human and ecosystem health. Model evaluations of SSA emissions have mainly focused on the global scale, but regional-scale evaluations are also important due to the localized impact of SSAs on atmospheric chemistry near the coast. In this study, SSA emissions in the Community Multiscale Air Quality (CMAQ) model were updated to enhance the...

  3. Large-Scale Traveling Weather Systems in Mars Southern Extratropics

    Hollingsworth, Jeffery L.; Kahre, Melinda A.

    2017-01-01

    Between late fall and early spring, Mars' middle- and high-latitude atmosphere supports strong mean equator-to-pole temperature contrasts and an accompanying mean westerly polar vortex. Observations from both the MGS Thermal Emission Spectrometer (TES) and the MRO Mars Climate Sounder (MCS) indicate that a mean baroclinicity-barotropicity supports intense, large-scale eastward traveling weather systems (i.e., transient synoptic-period waves). Such extratropical weather disturbances are critical components of the global circulation as they serve as agents in the transport of heat and momentum, and generalized scalar/tracer quantities (e.g., atmospheric dust, water-vapor and ice clouds). The character of such traveling extratropical synoptic disturbances in Mars' southern hemisphere during late winter through early spring is investigated using a moderately high-resolution Mars global climate model (Mars GCM). This Mars GCM imposes interactively-lifted and radiatively-active dust based on a threshold value of the surface stress. The model exhibits a reasonable "dust cycle" (i.e., globally averaged, a dustier atmosphere during southern spring and summer occurs). Compared to the northern-hemisphere counterparts, the southern synoptic-period weather disturbances and accompanying frontal waves have smaller meridional and zonal scales, and are far less intense. Influences of the zonally asymmetric (i.e., east-west varying) topography on southern large-scale weather are investigated, in addition to large-scale up-slope/down-slope flows and the diurnal cycle. A southern storm zone in late winter and early spring presents in the western hemisphere via orographic influences from the Tharsis highlands, and the Argyre and Hellas impact basins. Geographically localized transient-wave activity diagnostics are constructed that illuminate dynamical differences amongst the simulations and these are presented.

  4. Multiscale methods in computational fluid and solid mechanics

    Borst, de R.; Hulshoff, S.J.; Lenz, S.; Munts, E.A.; Brummelen, van E.H.; Wall, W.; Wesseling, P.; Onate, E.; Periaux, J.

    2006-01-01

    First, an attempt is made towards gaining a more systematic understanding of recent progress in multiscale modelling in computational solid and fluid mechanics. Sub- sequently, the discussion is focused on variational multiscale methods for the compressible and incompressible Navier-Stokes

  5. Transitions of the Multi-Scale Singularity Trees

    Somchaipeng, Kerawit; Sporring, Jon; Kreiborg, Sven

    2005-01-01

    Multi-Scale Singularity Trees(MSSTs) [10] are multi-scale image descriptors aimed at representing the deep structures of images. Changes in images are directly translated to changes in the deep structures; therefore transitions in MSSTs. Because MSSTs can be used to represent the deep structure...

  6. Astrobiological aspects of Mars and human presence: pros and cons.

    Horneck, G

    2008-08-01

    After the realization of the International Space Station, human exploratory missions to Moon or Mars, i.e. beyond low Earth orbit, are widely considered as the next logical step of peaceful cooperation in space on a global scale. Besides the human desire to extend the window of habitability, human exploratory missions are driven by several aspects of science, technology, culture and economy. Mars is currently considered as a major target in the search for life beyond the Earth. Understanding the history of water on Mars appears to be one of the clues to the puzzle on the probability of life on Mars. On Earth microorganisms have flourished for more than 3.5 Ga and have developed strategies to cope with so-called extreme conditions (e.g., hot vents, permafrost, subsurface regions, rocks or salt crystals). Therefore, in search for life on Mars, microorganisms are the most likely candidates for a putative biota on Mars and the search for morphological or chemical signatures of life or its relics is one of the primary and most exciting goals of Mars exploration. The presence of humans on the surface of Mars will substantially increase this research potential, e.g., by supporting deep subsurface drilling and by allowing intellectual collection and sophisticated in situ analysis of samples of astrobiological interest. On the other hand, such long-duration missions beyond LEO will add a new dimension to human space flight, concerning the distance of travel, the radiation environment, the gravity levels, the duration of the mission, and the level of confinement and isolation the crew will be exposed to. This will raise the significance of several health issues, above all radiation protection, gravity related effects as well as psychological issues. Furthermore, the import of internal and external microorganisms inevitably accompanying any human mission to Mars, or brought purposely to Mars as part of a bioregenerative life support system needs careful consideration with

  7. Multi-Scale Validation of a Nanodiamond Drug Delivery System and Multi-Scale Engineering Education

    Schwalbe, Michelle Kristin

    2010-01-01

    This dissertation has two primary concerns: (i) evaluating the uncertainty and prediction capabilities of a nanodiamond drug delivery model using Bayesian calibration and bias correction, and (ii) determining conceptual difficulties of multi-scale analysis from an engineering education perspective. A Bayesian uncertainty quantification scheme…

  8. Thermophysical Properties of Mars' North Polar Layered Deposits and Related Materials from Mars Odyssey THEMIS

    Vasavada, A. R.; Richardson, M. I.; Byrne, S.; Ivanov, A. B.; Christensen, P. R.

    2003-01-01

    The presence of a thick sequence of horizontal layers of ice-rich material at Mars north pole, dissected by troughs and eroding at its margins, is undoubtedly telling us something about the evolution of Mars climate [1,2] we just don t know what yet. The North Polar Layered Deposits (NPLD) most likely formed as astronomically driven climate variations led to the deposition of conformable, areally extensive layers of ice and dust over the polar region. More recently, the balance seems to have fundamentally shifted to net erosion, as evidenced by the many troughs within the NPLD and the steep, arcuate scarps present near its margins, both of which expose layering. We defined a number of Regions of Interest ROI) for THEMIS to target as part of the Mars Odyssey Participating Scientist program. We use these THEMIS data in order to understand the morphology and color/thermal properties of the NPLD and related materials over relevant (i.e., m to km) spatial scales. We have assembled color mosaics of our ROIs in order to map the distribution of ices, the different layered units, dark material, and underlying basement. The color information from THEMIS is crucial for distinguishing these different units which are less distinct on Mars Orbiter Camera images. We wish to understand the nature of the marginal scarps and their relationship to the dark material. Our next, more ambitious goal is to derive the thermophysical properties of the different geologic materials using THEMIS and Mars Global Surveyor Thermal Emission Spectrometer TES) data.

  9. Reducing greenhouses and the temperature history of earth and Mars

    Sagan, C.

    1977-01-01

    It has been suggested that NH3 and other reducing gases were present in the earth's primitive atmosphere, enhancing the global greenhouse effect; data obtained through isotopic archeothermometry support this hypothesis. Computations have been applied to the evolution of surface temperatures on Mars, considering various bolometric albedos and compositions. The results are of interest in the study of Martian sinuous channels which may have been created by aqueous fluvial errosion, and imply that clement conditions may have previously occurred on Mars, and may occur in the future.

  10. Duration of liquid water habitats on early Mars

    Mckay, C.P.; Davis, W.L.

    1991-01-01

    The duration of ice-covered lakes after the initial freezing of the early Mars is presently estimated via a climate model whose critical parameter is the existence of peak seasonal temperatures above freezing, and in which the variability of insolation is included. Under conditions in which meltwater was supplied by an ice source, it is found that water habitats could have been maintained under relatively thin ice sheets for as many as 700 million years after the onset of below-freezing global temperatures. The duration of such habitats on the early Mars therefore exceeds the upper limit of the time envisioned for the emergence of aquatic life on earth. 45 refs

  11. Efficient algorithms for multiscale modeling in porous media

    Wheeler, Mary F.; Wildey, Tim; Xue, Guangri

    2010-01-01

    We describe multiscale mortar mixed finite element discretizations for second-order elliptic and nonlinear parabolic equations modeling Darcy flow in porous media. The continuity of flux is imposed via a mortar finite element space on a coarse grid scale, while the equations in the coarse elements (or subdomains) are discretized on a fine grid scale. We discuss the construction of multiscale mortar basis and extend this concept to nonlinear interface operators. We present a multiscale preconditioning strategy to minimize the computational cost associated with construction of the multiscale mortar basis. We also discuss the use of appropriate quadrature rules and approximation spaces to reduce the saddle point system to a cell-centered pressure scheme. In particular, we focus on multiscale mortar multipoint flux approximation method for general hexahedral grids and full tensor permeabilities. Numerical results are presented to verify the accuracy and efficiency of these approaches. © 2010 John Wiley & Sons, Ltd.

  12. A complete categorization of multiscale models of infectious disease systems.

    Garira, Winston

    2017-12-01

    Modelling of infectious disease systems has entered a new era in which disease modellers are increasingly turning to multiscale modelling to extend traditional modelling frameworks into new application areas and to achieve higher levels of detail and accuracy in characterizing infectious disease systems. In this paper we present a categorization framework for categorizing multiscale models of infectious disease systems. The categorization framework consists of five integration frameworks and five criteria. We use the categorization framework to give a complete categorization of host-level immuno-epidemiological models (HL-IEMs). This categorization framework is also shown to be applicable in categorizing other types of multiscale models of infectious diseases beyond HL-IEMs through modifying the initial categorization framework presented in this study. Categorization of multiscale models of infectious disease systems in this way is useful in bringing some order to the discussion on the structure of these multiscale models.

  13. Efficient algorithms for multiscale modeling in porous media

    Wheeler, Mary F.

    2010-09-26

    We describe multiscale mortar mixed finite element discretizations for second-order elliptic and nonlinear parabolic equations modeling Darcy flow in porous media. The continuity of flux is imposed via a mortar finite element space on a coarse grid scale, while the equations in the coarse elements (or subdomains) are discretized on a fine grid scale. We discuss the construction of multiscale mortar basis and extend this concept to nonlinear interface operators. We present a multiscale preconditioning strategy to minimize the computational cost associated with construction of the multiscale mortar basis. We also discuss the use of appropriate quadrature rules and approximation spaces to reduce the saddle point system to a cell-centered pressure scheme. In particular, we focus on multiscale mortar multipoint flux approximation method for general hexahedral grids and full tensor permeabilities. Numerical results are presented to verify the accuracy and efficiency of these approaches. © 2010 John Wiley & Sons, Ltd.

  14. 'Endurance' Courtesy of Mars Express

    2004-01-01

    NASA's Mars Exploration Rover Opportunity used its panoramic camera to capture this false-color image of the interior of 'Endurance Crater' on the rover's 188th martian day (Aug. 4, 2004). The image data were relayed to Earth by the European Space Agency's Mars Express orbiter. The image was generated from separate frames using the cameras 750-, 530- and 480-nanometer filters.

  15. Mars oxygen production system design

    Cotton, Charles E.; Pillow, Linda K.; Perkinson, Robert C.; Brownlie, R. P.; Chwalowski, P.; Carmona, M. F.; Coopersmith, J. P.; Goff, J. C.; Harvey, L. L.; Kovacs, L. A.

    1989-01-01

    The design and construction phase is summarized of the Mars oxygen demonstration project. The basic hardware required to produce oxygen from simulated Mars atmosphere was assembled and tested. Some design problems still remain with the sample collection and storage system. In addition, design and development of computer compatible data acquisition and control instrumentation is ongoing.

  16. Life sciences and Mars exploration

    Sulzman, Frank M.; Rummel, John D.; Leveton, Lauren B.; Teeter, Ron

    1990-01-01

    The major life science considerations for Mars exploration missions are discussed. Radiation protection and countermeasures for zero gravity are discussed. Considerations of crew psychological health considerations and life support systems are addressed. Scientific opportunities presented by manned Mars missions are examined.

  17. Water and Life on Mars

    McKay, Christopher P.; DeVincenzi, Donald (Technical Monitor)

    2000-01-01

    Mars appears to be cold dry and dead world. However there is good evidence that early in its history it had liquid water, more active volcanism, and a thicker atmosphere. Mars had this earth-like environment over three and a half billion years ago, during the same time that life appeared on Earth. The main question in the exploration of Mars then is the search for a independent origin of life on that planet. Ecosystems in cold, dry locations on Earth - such as the Antarctic - provide examples of how life on Mars might have survived and where to look for fossils. Although the Viking results may indicate that Mars has no life today, there is direct geomorphological evidence that, in the past, Mars had large amounts of liquid water on its surface - possibly due to a thicker atmosphere. From a biological perspective the existence of liquid water, by itself motivates the question of the origin of life on Mars. One of the martian meteorites dates back to this early period and may contain evidence consistent with life. From studies of the Earth's earliest biosphere we know that by 3.5 Gyr. ago, life had originated on Earth and reached a fair degree of biological sophistication. Surface activity and erosion on Earth make it difficult to trace the history of life before the 3.5 Gyr timeframe. Ecosystems in cold, dry locations on Earth - such as the Antarctic - provide examples of how life on Mars might have survived and where to look for fossils.

  18. Mars Sample Return Architecture Overview

    Edwards, C. D.; Vijendran, S.

    2018-04-01

    NASA and ESA are exploring potential concepts for a Sample Retrieval Lander and Earth Return Orbiter that could return samples planned to be collected and cached by the Mars 2020 rover mission. We provide an overview of the Mars Sample Return architecture.

  19. Life on Mars

    Venkatavaradan, V S [Tata Inst. of Fundamental Research, Bombay (India)

    1976-10-01

    The miniature biological laboratory of the Viking-1 lander had three experiments to determine, whether the micro-organisms of the Martian soil has: (1) photo-synthetic activity (2) metabolic process activity (utilisation of nutrients) and (3) respiration. The Martian soil was warmed in an incubator and exposed to carbon dioxide (containing C/sup 14/) in presence of xenon arc lamp to simulate the Sun. If the Martian organisms of the expected type are present in the soil, the gas released during the heating would be radio-active which can be detected by a radiation counter. The three experiments had given positive signals denoting the presence of micro-organisms on the surface of Mars. The presence of superoxide in the soil would be poisonous to life but it is likely that organisms may survive deeper below the soil, where the chemicals would not be formed. The Viking-2 results also offered similar results. However, the basic question whether there is life on Mars still remains unanswered.

  20. Life on Mars

    Venkatavaradan, V.S.

    1976-01-01

    The miniature biological laboratory of the Viking-1 lander had three experiments to determine, whether the micro-organisms of the Martian soil has: (1) photo-synthetic activity (2) metabolic process activity (utilisation of nutrients) and (3) respiration. The Martian soil was warmed in an incubator and exposed to carbon dioxide (containing C 14 ) in presence of xenon arc lamp to simulate the Sun. If the Martian organisms of the expected type are present in the soil, the gas released during the heating would be radio-active which can be detected by a radiation counter. The three experiments had given positive signals denoting the presence of micro-organisms on the surface of Mars. The presence of superoxide in the soil would be poisonous to life but it is likely that organisms may survive deeper below the soil, where the chemicals would not be formed. The Viking-2 results also offered similar results. However, the basic question whether there is life on Mars still remains unanswered. (K.M.)

  1. Safety during MARS exercise

    2015-01-01

    It is MARS(1) time again! All employed members of the CERN personnel are currently undergoing the annual MARS evaluations.   This is also a good occasion for supervisors and their supervisees to fill in or update the OHS-0-0-3 form(2) “Identification of occupational hazards”. Filling in the OHS-0-0-3 form is an opportunity to assess any safety issues related to the supervisee's activities.  Each of us should, together with our supervisor, regularly identify and assess the hazards we may be exposed to in the course of our professional activities and reflect on how to control and mitigate them. When filling in the OHS form for the first time, it is important to determine any potential hazards as well as the corresponding preventive measures, in particular training and protective equipment. When updating the form, please review the available information to ensure that it still corresponds to the current activities. The form should be updated w...

  2. Austere Human Missions to Mars

    Price, Hoppy; Hawkins, Alisa M.; Tadcliffe, Torrey O.

    2009-01-01

    The Design Reference Architecture 5 (DRA 5) is the most recent concept developed by NASA to send humans to Mars in the 2030 time frame using Constellation Program elements. DRA 5 is optimized to meet a specific set of requirements that would provide for a robust exploration program to deliver a new six-person crew at each biennial Mars opportunity and provide for power and infrastructure to maintain a highly capable continuing human presence on Mars. This paper examines an alternate architecture that is scaled back from DRA 5 and might offer lower development cost, lower flight cost, and lower development risk. It is recognized that a mission set using this approach would not meet all the current Constellation Mars mission requirements; however, this 'austere' architecture may represent a minimum mission set that would be acceptable from a science and exploration standpoint. The austere approach is driven by a philosophy of minimizing high risk or high cost technology development and maximizing development and production commonality in order to achieve a program that could be sustained in a flat-funded budget environment. Key features that would enable a lower technology implementation are as follows: using a blunt-body entry vehicle having no deployable decelerators, utilizing aerobraking rather than aerocapture for placing the crewed element into low Mars orbit, avoiding the use of liquid hydrogen with its low temperature and large volume issues, using standard bipropellant propulsion for the landers and ascent vehicle, and using radioisotope surface power systems rather than a nuclear reactor or large area deployable solar arrays. Flat funding within the expected NASA budget for a sustained program could be facilitated by alternating cargo and crew launches for the biennial Mars opportunities. This would result in two assembled vehicles leaving Earth orbit for Mars per Mars opportunity. The first opportunity would send two cargo landers to the Mars surface to

  3. Multiscale approaches to high efficiency photovoltaics

    Connolly James Patrick

    2016-01-01

    Full Text Available While renewable energies are achieving parity around the globe, efforts to reach higher solar cell efficiencies becomes ever more difficult as they approach the limiting efficiency. The so-called third generation concepts attempt to break this limit through a combination of novel physical processes and new materials and concepts in organic and inorganic systems. Some examples of semi-empirical modelling in the field are reviewed, in particular for multispectral solar cells on silicon (French ANR project MultiSolSi. Their achievements are outlined, and the limits of these approaches shown. This introduces the main topic of this contribution, which is the use of multiscale experimental and theoretical techniques to go beyond the semi-empirical understanding of these systems. This approach has already led to great advances at modelling which have led to modelling software, which is widely known. Yet, a survey of the topic reveals a fragmentation of efforts across disciplines, firstly, such as organic and inorganic fields, but also between the high efficiency concepts such as hot carrier cells and intermediate band concepts. We show how this obstacle to the resolution of practical research obstacles may be lifted by inter-disciplinary cooperation across length scales, and across experimental and theoretical fields, and finally across materials systems. We present a European COST Action “MultiscaleSolar” kicking off in early 2015, which brings together experimental and theoretical partners in order to develop multiscale research in organic and inorganic materials. The goal of this defragmentation and interdisciplinary collaboration is to develop understanding across length scales, which will enable the full potential of third generation concepts to be evaluated in practise, for societal and industrial applications.

  4. MEGAPOLI: concept of multi-scale modelling of megacity impact on air quality and climate

    Baklanov, A.; Lawrence, M.; Pandis, S.; Mahura, A.; Finardi, S.; Moussiopoulos, N.; Beekmann, M.; Laj, P.; Gomes, L.; Jaffrezo, J.-L.; Borbon, A.; Coll, I.; Gros, V.; Sciare, J.; Kukkonen, J.; Galmarini, S.; Giorgi, F.; Grimmond, S.; Esau, I.; Stohl, A.; Denby, B.; Wagner, T.; Butler, T.; Baltensperger, U.; Builtjes, P.; van den Hout, D.; van der Gon, H. D.; Collins, B.; Schluenzen, H.; Kulmala, M.; Zilitinkevich, S.; Sokhi, R.; Friedrich, R.; Theloke, J.; Kummer, U.; Jalkinen, L.; Halenka, T.; Wiedensholer, A.; Pyle, J.; Rossow, W. B.

    2010-11-01

    The EU FP7 Project MEGAPOLI: "Megacities: Emissions, urban, regional and Global Atmospheric POLlution and climate effects, and Integrated tools for assessment and mitigation" (http://megapoli.info) brings together leading European research groups, state-of-the-art scientific tools and key players from non-European countries to investigate the interactions among megacities, air quality and climate. MEGAPOLI bridges the spatial and temporal scales that connect local emissions, air quality and weather with global atmospheric chemistry and climate. The suggested concept of multi-scale integrated modelling of megacity impact on air quality and climate and vice versa is discussed in the paper. It requires considering different spatial and temporal dimensions: time scales from seconds and hours (to understand the interaction mechanisms) up to years and decades (to consider the climate effects); spatial resolutions: with model down- and up-scaling from street- to global-scale; and two-way interactions between meteorological and chemical processes.

  5. Structure and multiscale mechanics of carbon nanomaterials

    2016-01-01

    This book aims at providing a broad overview on the relationship between structure and mechanical properties of carbon nanomaterials from world-leading scientists in the field. The main aim is to get an in-depth understanding of the broad range of mechanical properties of carbon materials based on their unique nanostructure and on defects of several types and at different length scales. Besides experimental work mainly based on the use of (in-situ) Raman and X-ray scattering and on nanoindentation, the book also covers some aspects of multiscale modeling of the mechanics of carbon nanomaterials.

  6. Multiscale agent-based cancer modeling.

    Zhang, Le; Wang, Zhihui; Sagotsky, Jonathan A; Deisboeck, Thomas S

    2009-04-01

    Agent-based modeling (ABM) is an in silico technique that is being used in a variety of research areas such as in social sciences, economics and increasingly in biomedicine as an interdisciplinary tool to study the dynamics of complex systems. Here, we describe its applicability to integrative tumor biology research by introducing a multi-scale tumor modeling platform that understands brain cancer as a complex dynamic biosystem. We summarize significant findings of this work, and discuss both challenges and future directions for ABM in the field of cancer research.

  7. Multi-scale Modelling of Segmentation

    Hartmann, Martin; Lartillot, Olivier; Toiviainen, Petri

    2016-01-01

    pieces. In a second experiment on non-real-time segmentation, musicians indicated boundaries and their strength for six examples. Kernel density estimation was used to develop multi-scale segmentation models. Contrary to previous research, no relationship was found between boundary strength and boundary......While listening to music, people often unwittingly break down musical pieces into constituent chunks such as verses and choruses. Music segmentation studies have suggested that some consensus regarding boundary perception exists, despite individual differences. However, neither the effects...

  8. The Potential Impact of Mars' Atmospheric Dust on Future Human Exploration of the Red Planet

    Winterhalter, D.; Levine, J. S.; Kerschmann, R.; Beaty, D. W.; Carrier, B. L.; Ashley, J. W.

    2017-12-01

    With the increasing focus by NASA and other space agencies on a crewed mission to Mars in the 2039 time-frame, many Mars-specific environmental factors are now starting to be considered by NASA and other engineering teams. Learning from NASA's Apollo Missions to the Moon, where lunar dust turned out to be a significant challenge to mission and crew safety, attention is now turning to the dust in Mars' atmosphere and regolith. To start the process of identifying possible dust-caused challenges to the human presence on Mars, and thus aid early engineering and mission design efforts, the NASA Engineering and Safety Center (NESC) Robotic Spacecraft Technical Discipline Team organized and conducted a Workshop on the "Dust in Mars' Atmosphere and Its Impact on the Human Exploration of Mars", held at the Lunar and Planetary Institute (LPI), Houston, TX, June 13-15, 2017. The workshop addressed the following general areas: 1. What is known about Mars' dust in terms of its physical and chemical properties, its local and global abundance and composition, and its variability.2. What is the impact of Mars atmospheric dust on human health.3. What is the impact of Mars atmospheric dust on surface mechanical systems (e.g., spacesuits, habitats, mobility systems, etc.). We present the top priority issues identified in the workshop.

  9. Case for a wet, warm climate on early Mars

    Pollack, J.B.; Kasting, J.F.; Richardson, S.M.; Poliakoff, K.

    1987-01-01

    Arguments are presented in support of the idea that Mars possessed a dense CO 2 atmosphere and a wet, warm climate early in its history. The plausibility of a CO 2 greenhouse is tested by formulating a simple model of the CO 2 geochemical cycle on early Mars. By scaling the rate of silicate weathering on Earth, researchers estimated a weathering time constant of the order of several times 10 to the 7th power years for early Mars. Thus, a dense atmosphere could have existed for a geologically significant time period (approx. 10 to the 9th power years) only if atmospheric CO 2 was being continuously resupplied. The most likely mechanism by which this could have been accomplished is the thermal decomposition of carbonate rocks induced directly or indirectly by intense, global scale volcanism

  10. Mars: Stratigraphy of Western Highlands and Polar Regions

    Tanaka, K. L.; Scott, D. H.; Tuesink, M. F.

    1985-01-01

    Geologic mapping and stratigraphic studies of Mars based on Viking images improved knowledge of the relative age and occurrence of geologic units on a global scale. Densities of geologic units or features during the Noarchian, Hesperian, and Amazonian periods are indicated for the North and South polar regions as well as the equatorial region of Mars. Cumulative counts of crater size frequencies for craters larger than 2 km in diameter on plateau units mapped in the western region of Mars counts indicate that the plateau terrain as a whole was thinly resurfaced during the Hesperian Period, and a large proportion of pre-existing craters less than 10 to 15 km in diameter was buried. The formation of northern plains, subpolar highlands, and both polar regions is also described.

  11. Toward multiscale modelings of grain-fluid systems

    Chareyre, Bruno; Yuan, Chao; Montella, Eduard P.; Salager, Simon

    2017-06-01

    Computationally efficient methods have been developed for simulating partially saturated granular materials in the pendular regime. In contrast, one hardly avoid expensive direct resolutions of 2-phase fluid dynamics problem for mixed pendular-funicular situations or even saturated regimes. Following previous developments for single-phase flow, a pore-network approach of the coupling problems is described. The geometry and movements of phases and interfaces are described on the basis of a tetrahedrization of the pore space, introducing elementary objects such as bridge, meniscus, pore body and pore throat, together with local rules of evolution. As firmly established local rules are still missing on some aspects (entry capillary pressure and pore-scale pressure-saturation relations, forces on the grains, or kinetics of transfers in mixed situations) a multi-scale numerical framework is introduced, enhancing the pore-network approach with the help of direct simulations. Small subsets of a granular system are extracted, in which multiphase scenario are solved using the Lattice-Boltzman method (LBM). In turns, a global problem is assembled and solved at the network scale, as illustrated by a simulated primary drainage.

  12. ESCOMPTE 2001: multi-scale modelling and experimental validation

    Cousin, F.; Tulet, P.; Rosset, R.

    2003-04-01

    ESCOMPTE is a European pollution field experiment located in the Marseille / Fos-Berre area in the summer 2001.This Mediterranean area, with frequent pollution peaks, is characterized by a complex topography subject to sea breeze regimes, together with intense localized urban, industrial and biogenic sources. Four POI have been selected, the most significant being POI2a / b, a 6-day pollution episode extensively documented for dynamics, radiation, gas phase and aerosols, with surface measurements (including measurements at sea in the gulf of Genoa, on board instrumented ferries between Marseille and Corsica), 7 aircrafts, lidar, radar and constant-level flight balloon soundings. The two-way mesoscale model MESO-NH-C (MNH-C), with horizontal resolutions of 9 and 3 km and high vertical resolution (up to 40 levels in the first 2 km), embedded in the global CTM Mocage, has been run for all POIs, with a focus here on POI2b (June 24-27,2001), a typical high pollution episode. The multi-scale modelling system MNH-C+MOCAGE allows to simulate local and regional pollution issued from emission sources in the Marseille / Fos-Berre area as well as from remote sources (e.g. the Po Valley and / or western Mediterranean sources) and their associated transboundary pollution fluxes. Detailed dynamical, chemical and aerosol (both modal and sectional spectra with organics and inorganics) simulations generally favorably compare to surface(continental and on ships), lidar and along-flight aircraft measurements.

  13. Polygon on Mars

    2008-01-01

    This image shows a small-scale polygonal pattern in the ground near NASA's Phoenix Mars Lander. This pattern is similar in appearance to polygonal structures in icy ground in the arctic regions of Earth. Phoenix touched down on the Red Planet at 4:53 p.m. Pacific Time (7:53 p.m. Eastern Time), May 25, 2008, in an arctic region called Vastitas Borealis, at 68 degrees north latitude, 234 degrees east longitude. This image was acquired by the Surface Stereo Imager shortly after landing. On the Phoenix mission calendar, landing day is known as Sol 0, the first Martian day of the mission. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  14. The Mars water cycle

    Davies, D. W.

    1981-01-01

    A model has been developed to test the hypothesis that the observed seasonal and latitudinal distribution of water on Mars is controlled by the sublimation and condensation of surface ice deposits in the Arctic and Antarctic, and the meridional transport of water vapor. Besides reproducing the observed water vapor distribution, the model correctly reproduces the presence of a large permanent ice cap in the Arctic and not in the Antarctic. No permanent ice reservoirs are predicted in the temperate or equatorial zones. Wintertime ice deposits in the Arctic are shown to be the source of the large water vapor abundances observed in the Arctic summertime, and the moderate water vapor abundances in the northern temperate region. Model calculations suggest that a year without dust storms results in very little change in the water vapor distribution. The current water distribution appears to be the equilibrium distribution for present atmospheric conditions.

  15. Mechanistic site-based emulation of a global ocean biogeochemical model (MEDUSA 1.0 for parametric analysis and calibration: an application of the Marine Model Optimization Testbed (MarMOT 1.1

    J. C. P. Hemmings

    2015-03-01

    Full Text Available Biogeochemical ocean circulation models used to investigate the role of plankton ecosystems in global change rely on adjustable parameters to capture the dominant biogeochemical dynamics of a complex biological system. In principle, optimal parameter values can be estimated by fitting models to observational data, including satellite ocean colour products such as chlorophyll that achieve good spatial and temporal coverage of the surface ocean. However, comprehensive parametric analyses require large ensemble experiments that are computationally infeasible with global 3-D simulations. Site-based simulations provide an efficient alternative but can only be used to make reliable inferences about global model performance if robust quantitative descriptions of their relationships with the corresponding 3-D simulations can be established. The feasibility of establishing such a relationship is investigated for an intermediate complexity biogeochemistry model (MEDUSA coupled with a widely used global ocean model (NEMO. A site-based mechanistic emulator is constructed for surface chlorophyll output from this target model as a function of model parameters. The emulator comprises an array of 1-D simulators and a statistical quantification of the uncertainty in their predictions. The unknown parameter-dependent biogeochemical environment, in terms of initial tracer concentrations and lateral flux information required by the simulators, is a significant source of uncertainty. It is approximated by a mean environment derived from a small ensemble of 3-D simulations representing variability of the target model behaviour over the parameter space of interest. The performance of two alternative uncertainty quantification schemes is examined: a direct method based on comparisons between simulator output and a sample of known target model "truths" and an indirect method that is only partially reliant on knowledge of the target model output. In general, chlorophyll

  16. Using Multi-Scale Modeling Systems and Satellite Data to Study the Precipitation Processes

    Tao, Wei-Kuo; Chern, J.; Lamg, S.; Matsui, T.; Shen, B.; Zeng, X.; Shi, R.

    2011-01-01

    In recent years, exponentially increasing computer power has extended Cloud Resolving Model (CRM) integrations from hours to months, the number of computational grid points from less than a thousand to close to ten million. Three-dimensional models are now more prevalent. Much attention is devoted to precipitating cloud systems where the crucial 1-km scales are resolved in horizontal domains as large as 10,000 km in two-dimensions, and 1,000 x 1,000 km2 in three-dimensions. Cloud resolving models now provide statistical information useful for developing more realistic physically based parameterizations for climate models and numerical weather prediction models. It is also expected that NWP and mesoscale model can be run in grid size similar to cloud resolving model through nesting technique. Recently, a multi-scale modeling system with unified physics was developed at NASA Goddard. It consists of (l) a cloud-resolving model (Goddard Cumulus Ensemble model, GCE model), (2) a regional scale model (a NASA unified weather research and forecast, WRF), (3) a coupled CRM and global model (Goddard Multi-scale Modeling Framework, MMF), and (4) a land modeling system. The same microphysical processes, long and short wave radiative transfer and land processes and the explicit cloud-radiation, and cloud-land surface interactive processes are applied in this multi-scale modeling system. This modeling system has been coupled with a multi-satellite simulator to use NASA high-resolution satellite data to identify the strengths and weaknesses of cloud and precipitation processes simulated by the model. In this talk, the recent developments and applications of the multi-scale modeling system will be presented. In particular, the results from using multi-scale modeling system to study the precipitating systems and hurricanes/typhoons will be presented. The high-resolution spatial and temporal visualization will be utilized to show the evolution of precipitation processes. Also how to

  17. A multiscale model for virus capsid dynamics.

    Chen, Changjun; Saxena, Rishu; Wei, Guo-Wei

    2010-01-01

    Viruses are infectious agents that can cause epidemics and pandemics. The understanding of virus formation, evolution, stability, and interaction with host cells is of great importance to the scientific community and public health. Typically, a virus complex in association with its aquatic environment poses a fabulous challenge to theoretical description and prediction. In this work, we propose a differential geometry-based multiscale paradigm to model complex biomolecule systems. In our approach, the differential geometry theory of surfaces and geometric measure theory are employed as a natural means to couple the macroscopic continuum domain of the fluid mechanical description of the aquatic environment from the microscopic discrete domain of the atomistic description of the biomolecule. A multiscale action functional is constructed as a unified framework to derive the governing equations for the dynamics of different scales. We show that the classical Navier-Stokes equation for the fluid dynamics and Newton's equation for the molecular dynamics can be derived from the least action principle. These equations are coupled through the continuum-discrete interface whose dynamics is governed by potential driven geometric flows.

  18. Neural network based multiscale image restoration approach

    de Castro, Ana Paula A.; da Silva, José D. S.

    2007-02-01

    This paper describes a neural network based multiscale image restoration approach. Multilayer perceptrons are trained with artificial images of degraded gray level circles, in an attempt to make the neural network learn inherent space relations of the degraded pixels. The present approach simulates the degradation by a low pass Gaussian filter blurring operation and the addition of noise to the pixels at pre-established rates. The training process considers the degraded image as input and the non-degraded image as output for the supervised learning process. The neural network thus performs an inverse operation by recovering a quasi non-degraded image in terms of least squared. The main difference of the approach to existing ones relies on the fact that the space relations are taken from different scales, thus providing relational space data to the neural network. The approach is an attempt to come up with a simple method that leads to an optimum solution to the problem. Considering different window sizes around a pixel simulates the multiscale operation. In the generalization phase the neural network is exposed to indoor, outdoor, and satellite degraded images following the same steps use for the artificial circle image.

  19. Multiscale coherent structures in tokamak plasma turbulence

    Xu, G. S.; Wan, B. N.; Zhang, W.; Yang, Q. W.; Wang, L.; Wen, Y. Z.

    2006-01-01

    A 12-tip poloidal probe array is used on the HT-7 superconducting tokamak [Li, Wan, and Mao, Plasma Phys. Controlled Fusion 42, 135 (2000)] to measure plasma turbulence in the edge region. Some statistical analysis techniques are used to characterize the turbulence structures. It is found that the plasma turbulence is composed of multiscale coherent structures, i.e., turbulent eddies and there is self-similarity in a relative short scale range. The presence of the self-similarity is found due to the structural similarity of these eddies between different scales. These turbulent eddies constitute the basic convection cells, so the self-similar range is just the dominant scale range relevant to transport. The experimental results also indicate that the plasma turbulence is dominated by low-frequency and long-wavelength fluctuation components and its dispersion relation shows typical electron-drift-wave characteristics. Some large-scale coherent structures intermittently burst out and exhibit a very long poloidal extent, even longer than 6 cm. It is found that these large-scale coherent structures are mainly contributed by the low-frequency and long-wavelength fluctuating components and their presence is responsible for the observations of long-range correlations, i.e., the correlation in the scale range much longer than the turbulence decorrelation scale. These experimental observations suggest that the coexistence of multiscale coherent structures results in the self-similar turbulent state

  20. Multiscale structure in eco-evolutionary dynamics

    Stacey, Blake C.

    In a complex system, the individual components are neither so tightly coupled or correlated that they can all be treated as a single unit, nor so uncorrelated that they can be approximated as independent entities. Instead, patterns of interdependency lead to structure at multiple scales of organization. Evolution excels at producing such complex structures. In turn, the existence of these complex interrelationships within a biological system affects the evolutionary dynamics of that system. I present a mathematical formalism for multiscale structure, grounded in information theory, which makes these intuitions quantitative, and I show how dynamics defined in terms of population genetics or evolutionary game theory can lead to multiscale organization. For complex systems, "more is different," and I address this from several perspectives. Spatial host--consumer models demonstrate the importance of the structures which can arise due to dynamical pattern formation. Evolutionary game theory reveals the novel effects which can result from multiplayer games, nonlinear payoffs and ecological stochasticity. Replicator dynamics in an environment with mesoscale structure relates to generalized conditionalization rules in probability theory. The idea of natural selection "acting at multiple levels" has been mathematized in a variety of ways, not all of which are equivalent. We will face down the confusion, using the experience developed over the course of this thesis to clarify the situation.

  1. Institute for Multiscale Modeling of Biological Interactions

    Paulaitis, Michael E; Garcia-Moreno, Bertrand; Lenhoff, Abraham

    2009-12-26

    The Institute for Multiscale Modeling of Biological Interactions (IMMBI) has two primary goals: Foster interdisciplinary collaborations among faculty and their research laboratories that will lead to novel applications of multiscale simulation and modeling methods in the biological sciences and engineering; and Building on the unique biophysical/biology-based engineering foundations of the participating faculty, train scientists and engineers to apply computational methods that collectively span multiple time and length scales of biological organization. The success of IMMBI will be defined by the following: Size and quality of the applicant pool for pre-doctoral and post-doctoral fellows; Academic performance; Quality of the pre-doctoral and post-doctoral research; Impact of the research broadly and to the DOE (ASCR program) mission; Distinction of the next career step for pre-doctoral and post-doctoral fellows; and Faculty collaborations that result from IMMBI activities. Specific details about accomplishments during the three years of DOE support for IMMBI have been documented in Annual Progress Reports (April 2005, June 2006, and March 2007) and a Report for a National Academy of Sciences Review (October 2005) that were submitted to DOE on the dates indicated. An overview of these accomplishments is provided.

  2. Multi-scale biomedical systems: measurement challenges

    Summers, R

    2016-01-01

    Multi-scale biomedical systems are those that represent interactions in materials, sensors, and systems from a holistic perspective. It is possible to view such multi-scale activity using measurement of spatial scale or time scale, though in this paper only the former is considered. The biomedical application paradigm comprises interactions that range from quantum biological phenomena at scales of 10-12 for one individual to epidemiological studies of disease spread in populations that in a pandemic lead to measurement at a scale of 10+7. It is clear that there are measurement challenges at either end of this spatial scale, but those challenges that relate to the use of new technologies that deal with big data and health service delivery at the point of care are also considered. The measurement challenges lead to the use, in many cases, of model-based measurement and the adoption of virtual engineering. It is these measurement challenges that will be uncovered in this paper. (paper)

  3. Multiscale permutation entropy analysis of electrocardiogram

    Liu, Tiebing; Yao, Wenpo; Wu, Min; Shi, Zhaorong; Wang, Jun; Ning, Xinbao

    2017-04-01

    To make a comprehensive nonlinear analysis to ECG, multiscale permutation entropy (MPE) was applied to ECG characteristics extraction to make a comprehensive nonlinear analysis of ECG. Three kinds of ECG from PhysioNet database, congestive heart failure (CHF) patients, healthy young and elderly subjects, are applied in this paper. We set embedding dimension to 4 and adjust scale factor from 2 to 100 with a step size of 2, and compare MPE with multiscale entropy (MSE). As increase of scale factor, MPE complexity of the three ECG signals are showing first-decrease and last-increase trends. When scale factor is between 10 and 32, complexities of the three ECG had biggest difference, entropy of the elderly is 0.146 less than the CHF patients and 0.025 larger than the healthy young in average, in line with normal physiological characteristics. Test results showed that MPE can effectively apply in ECG nonlinear analysis, and can effectively distinguish different ECG signals.

  4. A Multiscale Model for Virus Capsid Dynamics

    Changjun Chen

    2010-01-01

    Full Text Available Viruses are infectious agents that can cause epidemics and pandemics. The understanding of virus formation, evolution, stability, and interaction with host cells is of great importance to the scientific community and public health. Typically, a virus complex in association with its aquatic environment poses a fabulous challenge to theoretical description and prediction. In this work, we propose a differential geometry-based multiscale paradigm to model complex biomolecule systems. In our approach, the differential geometry theory of surfaces and geometric measure theory are employed as a natural means to couple the macroscopic continuum domain of the fluid mechanical description of the aquatic environment from the microscopic discrete domain of the atomistic description of the biomolecule. A multiscale action functional is constructed as a unified framework to derive the governing equations for the dynamics of different scales. We show that the classical Navier-Stokes equation for the fluid dynamics and Newton's equation for the molecular dynamics can be derived from the least action principle. These equations are coupled through the continuum-discrete interface whose dynamics is governed by potential driven geometric flows.

  5. Multiscale Convolutional Neural Networks for Hand Detection

    Shiyang Yan

    2017-01-01

    Full Text Available Unconstrained hand detection in still images plays an important role in many hand-related vision problems, for example, hand tracking, gesture analysis, human action recognition and human-machine interaction, and sign language recognition. Although hand detection has been extensively studied for decades, it is still a challenging task with many problems to be tackled. The contributing factors for this complexity include heavy occlusion, low resolution, varying illumination conditions, different hand gestures, and the complex interactions between hands and objects or other hands. In this paper, we propose a multiscale deep learning model for unconstrained hand detection in still images. Deep learning models, and deep convolutional neural networks (CNNs in particular, have achieved state-of-the-art performances in many vision benchmarks. Developed from the region-based CNN (R-CNN model, we propose a hand detection scheme based on candidate regions generated by a generic region proposal algorithm, followed by multiscale information fusion from the popular VGG16 model. Two benchmark datasets were applied to validate the proposed method, namely, the Oxford Hand Detection Dataset and the VIVA Hand Detection Challenge. We achieved state-of-the-art results on the Oxford Hand Detection Dataset and had satisfactory performance in the VIVA Hand Detection Challenge.

  6. Residual-driven online generalized multiscale finite element methods

    Chung, Eric T.

    2015-09-08

    The construction of local reduced-order models via multiscale basis functions has been an area of active research. In this paper, we propose online multiscale basis functions which are constructed using the offline space and the current residual. Online multiscale basis functions are constructed adaptively in some selected regions based on our error indicators. We derive an error estimator which shows that one needs to have an offline space with certain properties to guarantee that additional online multiscale basis function will decrease the error. This error decrease is independent of physical parameters, such as the contrast and multiple scales in the problem. The offline spaces are constructed using Generalized Multiscale Finite Element Methods (GMsFEM). We show that if one chooses a sufficient number of offline basis functions, one can guarantee that additional online multiscale basis functions will reduce the error independent of contrast. We note that the construction of online basis functions is motivated by the fact that the offline space construction does not take into account distant effects. Using the residual information, we can incorporate the distant information provided the offline approximation satisfies certain properties. In the paper, theoretical and numerical results are presented. Our numerical results show that if the offline space is sufficiently large (in terms of the dimension) such that the coarse space contains all multiscale spectral basis functions that correspond to small eigenvalues, then the error reduction by adding online multiscale basis function is independent of the contrast. We discuss various ways computing online multiscale basis functions which include a use of small dimensional offline spaces.

  7. Micro-Pressure Sensors for Future Mars Missions

    Catling, David C.

    1996-01-01

    The joint research interchange effort was directed at the following principal areas: u further development of NASA-Ames' Mars Micro-meteorology mission concept as a viable NASA space mission especially with regard to the science and instrument specifications u interaction with the flight team from NASA's New Millennium 'Deep-Space 2' (DS-2) mission with regard to selection and design of micro-pressure sensors for Mars u further development of micro-pressure sensors suitable for Mars The research work undertaken in the course of the Joint Research Interchange should be placed in the context of an ongoing planetary exploration objective to characterize the climate system on Mars. In particular, a network of small probes globally-distributed on the surface of the planet has often been cited as the only way to address this particular science goal. A team from NASA Ames has proposed such a mission called the Micrometeorology mission, or 'Micro-met' for short. Surface pressure data are all that are required, in principle, to calculate the Martian atmospheric circulation, provided that simultaneous orbital measurements of the atmosphere are also obtained. Consequently, in the proposed Micro-met mission a large number of landers would measure barometric pressure at various locations around Mars, each equipped with a micro-pressure sensor. Much of the time on the JRI was therefore spent working with the engineers and scientists concerned with Micro-met to develop this particular mission concept into a more realistic proposition.

  8. The Physics, Biology, and Environmental Ethics of Making Mars Habitable

    McKay, Christopher P.; Marinova, Margarita M.

    2001-03-01

    The considerable evidence that Mars once had a wetter, more clement, environment motivates the search for past or present life on that planet. This evidence also suggests the possibility of restoring habitable conditions on Mars. While the total amounts of the key molecules - carbon dioxide, water, and nitrogen - needed for creating a biosphere on Mars are unknown, estimates suggest that there may be enough in the subsurface. Super greenhouse gases, in particular, perfluorocarbons, are currently the most effective and practical way to warm Mars and thicken its atmosphere so that liquid water is stable on the surface. This process could take ~100 years. If enough carbon dioxide is frozen in the South Polar Cap and absorbed in the regolith, the resulting thick and warm carbon dioxide atmosphere could support many types of microorganisms, plants, and invertebrates. If a planet-wide martian biosphere converted carbon dioxide into oxygen with an average efficiency equal to that for Earth's biosphere, it would take >100,000 years to create Earth-like oxygen levels. Ethical issues associated with bringing life to Mars center on the possibility of indigenous martian life and the relative value of a planet with or without a global biosphere.

  9. The physics, biology, and environmental ethics of making mars habitable

    McKay, C. P.; Marinova, M. M.

    2001-01-01

    The considerable evidence that Mars once had a wetter, more clement, environment motivates the search for past or present life on that planet. This evidence also suggests the possibility of restoring habitable conditions on Mars. While the total amounts of the key molecules--carbon dioxide, water, and nitrogen--needed for creating a biosphere on Mars are unknown, estimates suggest that there may be enough in the subsurface. Super greenhouse gases, in particular, perfluorocarbons, are currently the most effective and practical way to warm Mars and thicken its atmosphere so that liquid water is stable on the surface. This process could take approximately 100 years. If enough carbon dioxide is frozen in the South Polar Cap and absorbed in the regolith, the resulting thick and warm carbon dioxide atmosphere could support many types of microorganisms, plants, and invertebrates. If a planet-wide martian biosphere converted carbon dioxide into oxygen with an average efficiency equal to that for Earth's biosphere, it would take > 100,000 years to create Earth-like oxygen levels. Ethical issues associated with bringing life to Mars center on the possibility of indigenous martian life and the relative value of a planet with or without a global biosphere.

  10. Noachian and more recent phyllosilicates in impact craters on Mars.

    Fairén, Alberto G; Chevrier, Vincent; Abramov, Oleg; Marzo, Giuseppe A; Gavin, Patricia; Davila, Alfonso F; Tornabene, Livio L; Bishop, Janice L; Roush, Ted L; Gross, Christoph; Kneissl, Thomas; Uceda, Esther R; Dohm, James M; Schulze-Makuch, Dirk; Rodríguez, J Alexis P; Amils, Ricardo; McKay, Christopher P

    2010-07-06

    Hundreds of impact craters on Mars contain diverse phyllosilicates, interpreted as excavation products of preexisting subsurface deposits following impact and crater formation. This has been used to argue that the conditions conducive to phyllosilicate synthesis, which require the presence of abundant and long-lasting liquid water, were only met early in the history of the planet, during the Noachian period (> 3.6 Gy ago), and that aqueous environments were widespread then. Here we test this hypothesis by examining the excavation process of hydrated minerals by impact events on Mars and analyzing the stability of phyllosilicates against the impact-induced thermal shock. To do so, we first compare the infrared spectra of thermally altered phyllosilicates with those of hydrated minerals known to occur in craters on Mars and then analyze the postshock temperatures reached during impact crater excavation. Our results show that phyllosilicates can resist the postshock temperatures almost everywhere in the crater, except under particular conditions in a central area in and near the point of impact. We conclude that most phyllosilicates detected inside impact craters on Mars are consistent with excavated preexisting sediments, supporting the hypothesis of a primeval and long-lasting global aqueous environment. When our analyses are applied to specific impact craters on Mars, we are able to identify both pre- and postimpact phyllosilicates, therefore extending the time of local phyllosilicate synthesis to post-Noachian times.

  11. Ionospheric Irregularities at Mars Probed by MARSIS Topside Sounding

    Harada, Y.; Gurnett, D. A.; Kopf, A. J.; Halekas, J. S.; Ruhunusiri, S.

    2018-01-01

    The upper ionosphere of Mars contains a variety of perturbations driven by solar wind forcing from above and upward propagating atmospheric waves from below. Here we explore the global distribution and variability of ionospheric irregularities around the exobase at Mars by analyzing topside sounding data from the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) instrument on board Mars Express. As irregular structure gives rise to off-vertical echoes with excess propagation time, the diffuseness of ionospheric echo traces can be used as a diagnostic tool for perturbed reflection surfaces. The observed properties of diffuse echoes above unmagnetized regions suggest that ionospheric irregularities with horizontal wavelengths of tens to hundreds of kilometers are particularly enhanced in the winter hemisphere and at high solar zenith angles. Given the known inverse dependence of neutral gravity wave amplitudes on the background atmospheric temperature, the ionospheric irregularities probed by MARSIS are most likely associated with plasma perturbations driven by atmospheric gravity waves. Though extreme events with unusually diffuse echoes are more frequently observed for high solar wind dynamic pressures during some time intervals, the vast majority of the diffuse echo events are unaffected by varying solar wind conditions, implying limited influence of solar wind forcing on the generation of ionospheric irregularities. Combination of remote and in situ measurements of ionospheric irregularities would offer the opportunity for a better understanding of the ionospheric dynamics at Mars.

  12. Mars Science Laboratory Entry Guidance Improvements for Mars 2018 (DRAFT)

    Garcia-Llama, Eduardo; Winski, Richard G.; Shidner, Jeremy D.; Ivanov, Mark C.; Grover, Myron R.; Prakash, Ravi

    2011-01-01

    In 2011, the Mars Science Laboratory (MSL) will be launched in a mission to deliver the largest and most capable rover to date to the surface of Mars. A follow on MSL-derived mission, referred to as Mars 2018, is planned for 2018. Mars 2018 goals include performance enhancements of the Entry, Descent and Landing over that of its predecessor MSL mission of 2011. This paper will discuss the main elements of the modified 2018 EDL preliminary design that will increase performance on the entry phase of the mission. In particular, these elements will increase the parachute deploy altitude to allow for more time margin during the subsequent descent and landing phases and reduce the delivery ellipse size at parachute deploy through modifications in the entry reference trajectory design, guidance trigger logic design, and the effect of additional navigation hardware.

  13. 100 New Impact Crater Sites Found on Mars

    Kennedy, M. R.; Malin, M. C.

    2009-12-01

    Recent observations constrain the formation of 100 new impact sites on Mars over the past decade; 19 of these were found using the Mars Global Surveyor Mars Orbiter Camera (MOC), and the other 81 have been identified since 2006 using the Mars Reconnaissance Orbiter Context Camera (CTX). Every 6 meter/pixel CTX image is examined upon receipt and, where they overlap images of 0.3-240 m/pixel scale acquired by the same or other Mars-orbiting spacecraft, we look for features that may have changed. New impact sites are initially identified by the presence of a new dark spot or cluster of dark spots in a CTX image. Such spots may be new impact craters, or result from the effect of impact blasts on the dusty surface. In some (generally rare) cases, the crater is sufficiently large to be resolved in the CTX image. In most cases, however, the crater(s) cannot be seen. These are tentatively designated as “candidate” new impact sites, and the CTX team then creates an opportunity for the MRO spacecraft to point its cameras off-nadir and requests that the High Resolution Imaging Science Experiment (HiRISE) team obtain an image of ~0.3 m/pixel to confirm whether a crater or crater cluster is present. It is clear even from cursory examination that the CTX observations are areographically biased to dusty, higher albedo areas on Mars. All but 3 of the 100 new impact sites occur on surfaces with Lambert albedo values in excess of 23.5%. Our initial study of MOC images greatly benefited from the initial global observations made in one month in 1999, creating a baseline date from which we could start counting new craters. The global coverage by MRO Mars Color Imager is more than a factor of 4 poorer in resolution than the MOC Wide Angle camera and does not offer the opportunity for global analysis. Instead, we must rely on partial global coverage and global coverage that has taken years to accumulate; thus we can only treat impact rates statistically. We subdivide the total data

  14. Low Cost Mars Surface Exploration: The Mars Tumbleweed

    Antol, Jeffrey; Calhoun, Philip; Flick, John; Hajos, Gregory; Kolacinski, Richard; Minton, David; Owens, Rachel; Parker, Jennifer

    2003-01-01

    The "Mars Tumbleweed," a rover concept that would utilize surface winds for mobility, is being examined as a low cost complement to the current Mars exploration efforts. Tumbleweeds carrying microinstruments would be driven across the Martian landscape by wind, searching for areas of scientific interest. These rovers, relatively simple, inexpensive, and deployed in large numbers to maximize coverage of the Martian surface, would provide a broad scouting capability to identify specific sites for exploration by more complex rover and lander missions.

  15. Analysis of complex time series using refined composite multiscale entropy

    Wu, Shuen-De; Wu, Chiu-Wen; Lin, Shiou-Gwo; Lee, Kung-Yen; Peng, Chung-Kang

    2014-01-01

    Multiscale entropy (MSE) is an effective algorithm for measuring the complexity of a time series that has been applied in many fields successfully. However, MSE may yield an inaccurate estimation of entropy or induce undefined entropy because the coarse-graining procedure reduces the length of a time series considerably at large scales. Composite multiscale entropy (CMSE) was recently proposed to improve the accuracy of MSE, but it does not resolve undefined entropy. Here we propose a refined composite multiscale entropy (RCMSE) to improve CMSE. For short time series analyses, we demonstrate that RCMSE increases the accuracy of entropy estimation and reduces the probability of inducing undefined entropy.

  16. Multi-Scale Scattering Transform in Music Similarity Measuring

    Wang, Ruobai

    Scattering transform is a Mel-frequency spectrum based, time-deformation stable method, which can be used in evaluating music similarity. Compared with Dynamic time warping, it has better performance in detecting similar audio signals under local time-frequency deformation. Multi-scale scattering means to combine scattering transforms of different window lengths. This paper argues that, multi-scale scattering transform is a good alternative of dynamic time warping in music similarity measuring. We tested the performance of multi-scale scattering transform against other popular methods, with data designed to represent different conditions.

  17. Generalization Performance of Regularized Ranking With Multiscale Kernels.

    Zhou, Yicong; Chen, Hong; Lan, Rushi; Pan, Zhibin

    2016-05-01

    The regularized kernel method for the ranking problem has attracted increasing attentions in machine learning. The previous regularized ranking algorithms are usually based on reproducing kernel Hilbert spaces with a single kernel. In this paper, we go beyond this framework by investigating the generalization performance of the regularized ranking with multiscale kernels. A novel ranking algorithm with multiscale kernels is proposed and its representer theorem is proved. We establish the upper bound of the generalization error in terms of the complexity of hypothesis spaces. It shows that the multiscale ranking algorithm can achieve satisfactory learning rates under mild conditions. Experiments demonstrate the effectiveness of the proposed method for drug discovery and recommendation tasks.

  18. SUV Tracks On Mars? The 'Devil' is in the Details

    1998-01-01

    Sport Utility Vehicles (SUVs) on Mars? Imagine the MOC imaging team's surprise on the morning of April 27, 1998, as the latest images came in from the 'Red Planet.'A picture taken by the camera on Mars Global Surveyor just one day earlier showed several thin, dark lines that--at first glance--looked like pathways blazed by off-road sport utility vehicles. Who's been driving around on Mars?The MOC image in question (#26403), seen here at full resolution of 13.8 meters (45 feet) per pixel, was obtained around 10:22 a.m. PDT on April 26, 1998, during Mars Global Surveyor's 264th orbit. North is approximately up, illumination is from the lower right. Located in eastern Arabia Terra near 16.5o N latitude, 311.4o W longitude, the image showed a number of natural features--small craters formed by meteor impact, several buttes and mesas left by erosion of the surrounding terrain, small dunes and drifts, and a mantle of dust that varies in thickness from place to place. But the new picture also showed two dark lines--each varying in width up to about 15 meters (49 feet)--that extended several kilometers/miles across the image.Lines like these have been seen before on Mars. They are most likely the result of dust devils--columnar vortices of wind that move across the landscape, pick up dust, and look somewhat like miniature tornadoes. Dust devils are a common occurrence in dry and desert landscapes on Earth as well as Mars. They form when the ground heats up during the day, warming the air immediately above the surface. As pockets of warm air rise and interfere with one another, they create horizontal pressure variations that, combined with other meteorological winds, cause the upward moving air to spin (the direction of the spin is controlled by the same Coriolis forces that cause terrestrial hurricanes to spin in specific directions). As the spinning column of air moves across the surface, it occasionally encounters dust on the surface, which it can suck upward. This dust

  19. Effect of Mesoscale and Multiscale Modeling on the Performance of Kevlar Woven Fabric Subjected to Ballistic Impact: A Numerical Study

    Jia, Xin; Huang, Zhengxiang; Zu, Xudong; Gu, Xiaohui; Xiao, Qiangqiang

    2013-12-01

    In this study, an optimal finite element model of Kevlar woven fabric that is more computational efficient compared with existing models was developed to simulate ballistic impact onto fabric. Kevlar woven fabric was modeled to yarn level architecture by using the hybrid elements analysis (HEA), which uses solid elements in modeling the yarns at the impact region and uses shell elements in modeling the yarns away from the impact region. Three HEA configurations were constructed, in which the solid element region was set as about one, two, and three times that of the projectile's diameter with impact velocities of 30 m/s (non-perforation case) and 200 m/s (perforation case) to determine the optimal ratio between the solid element region and the shell element region. To further reduce computational time and to maintain the necessary accuracy, three multiscale models were presented also. These multiscale models combine the local region with the yarn level architecture by using the HEA approach and the global region with homogenous level architecture. The effect of the varying ratios of the local and global area on the ballistic performance of fabric was discussed. The deformation and damage mechanisms of fabric were analyzed and compared among numerical models. Simulation results indicate that the multiscale model based on HEA accurately reproduces the baseline results and obviously decreases computational time.

  20. Special section introduction on MicroMars to MegaMars

    Bridges, Nathan T.; Dundas, Colin M.; Edgar, Lauren

    2016-01-01

    The study of Earth's surface and atmosphere evolved from local investigations to the incorporation of remote sensing on a global scale. The study of Mars has followed the opposite progression, beginning with telescopic observations, followed by flyby and orbital missions, landers, and finally rover missions in the last ∼20 years. This varied fleet of spacecraft (seven of which are currently operating as of this writing) provides a rich variety of datasets at spatial scales ranging from microscopic images to synoptic orbital remote sensing.

  1. Small Spacecraft Constellation Concept for Mars Atmospheric Radio Occultations

    Asmar, S. W.; Mannucci, A. J.; Ao, C. O.; Kobayashi, M. M.; Lazio, J.; Marinan, A.; Massone, G.; McCandless, S. E.; Preston, R. A.; Seubert, J.; Williamson, W.

    2017-12-01

    First demonstrated in 1965 when Mariner IV flew by Mars and determined the salient features of its atmosphere, radio occultation experiments have been carried out on numerous planetary missions with great discoveries. These experiments utilize the now classic configuration of a signal from a single planetary spacecraft to Earth receiving stations, where the science data are acquired. The Earth science community advanced the technique to utilizing a constellation of spacecraft with the radio occultation links between the spacecraft, enabled by the infrastructure of the Global Positioning System. With the advent of small and less costly spacecraft, such as planetary CubeSats and other variations, such as the anticipated innovative Mars Cube One mission, crosslinks among small spacecraft can be used to study other planets in the near future. Advantages of this type of experiment include significantly greater geographical coverage, which could reach global coverage over a few weeks with a small number of spacecraft. Repeatability of the global coverage can lead to examining temperature-pressure profiles and ionospheric electron density profiles, on daily, seasonal, annual, or other time scales of interest. The higher signal-to-noise ratio for inter-satellite links, compared to a link to Earth, decreases the design demands on the instrumentation (smaller antennas and transmitters, etc.). After an actual Mars crosslink demonstration, this concept has been in development using Mars as a possible target. Scientific objectives, delivery methods, operational scenarios and end-to-end configuration have been documented. Science objectives include determining the state and variability of the lower Martian atmosphere, which has been an identified as a high priority objective by the Mars Exploration Program Analysis Group, particularly as it relates to entry, descent, and landing and ascent for future crewed and robotic missions. This paper will present the latest research on the

  2. A New Multiscale Technique for Time-Accurate Geophysics Simulations

    Omelchenko, Y. A.; Karimabadi, H.

    2006-12-01

    Large-scale geophysics systems are frequently described by multiscale reactive flow models (e.g., wildfire and climate models, multiphase flows in porous rocks, etc.). Accurate and robust simulations of such systems by traditional time-stepping techniques face a formidable computational challenge. Explicit time integration suffers from global (CFL and accuracy) timestep restrictions due to inhomogeneous convective and diffusion processes, as well as closely coupled physical and chemical reactions. Application of adaptive mesh refinement (AMR) to such systems may not be always sufficient since its success critically depends on a careful choice of domain refinement strategy. On the other hand, implicit and timestep-splitting integrations may result in a considerable loss of accuracy when fast transients in the solution become important. To address this issue, we developed an alternative explicit approach to time-accurate integration of such systems: Discrete-Event Simulation (DES). DES enables asynchronous computation by automatically adjusting the CPU resources in accordance with local timescales. This is done by encapsulating flux- conservative updates of numerical variables in the form of events, whose execution and synchronization is explicitly controlled by imposing accuracy and causality constraints. As a result, at each time step DES self- adaptively updates only a fraction of the global system state, which eliminates unnecessary computation of inactive elements. DES can be naturally combined with various mesh generation techniques. The event-driven paradigm results in robust and fast simulation codes, which can be efficiently parallelized via a new preemptive event processing (PEP) technique. We discuss applications of this novel technology to time-dependent diffusion-advection-reaction and CFD models representative of various geophysics applications.

  3. The magnetic field of Mars according to data of Mars-3 and Mars-5 space vehicles

    Dolginov, Sh.Sh.; Eroshenko, E.G.; Zhuzgov, L.N.

    1975-01-01

    Magnitograms obtained by the space probe ''Mars-5'' on the evening and day sides as well as those from the ''Mars-3'' obtained earlier suggest the following: In the vicinity of Mars there exists a shock front and its disposition is tracked at various angles to the direction to the sun. Magnetometers have registered a region in space where magnetic field features the properties of a magnetosphere field in its topology and action on plasma. The magnetic field in the region of the ''magnitosphere'' does not change its sign when the interplanetary field does shile in adjacent boundary regions the regular part of the field changes its sign when that of the interplanetary field does. The configuration and dimensions of the ''magnitosphere'' depend on thesolar wind intensity. On the day side (''Mars-3'') the magnitospheric field ceases to be registered at an altitude of 2200km, whereas on the night side (''Mars-5'') the regular field is traced up to 7500-9500km from the planet surface. All the above unambiguously suggests that the planet Mars has its own magnetic field. Under the influence of the solar wind the field takes the characteristic form: it is limited on the day side and elongated on the night one. The topology oif force lines is explicable if one assumes that the axis of the Mars magnetic dipole is inclined to the rotation axis at an abgle of 15-20deg. The northern magnetic pole of the dipole is licated in the northern hemisphere, i.e. the Mars fields in their regularity are opposite to the geomagnetic field. The magnetic moment of the Mars dipole is equal to M=2.5x10 22 Gauss.cm 3 . (author)

  4. Toward multi-scale simulation of reconnection phenomena in space plasma

    Den, M.; Horiuchi, R.; Usami, S.; Tanaka, T.; Ogawa, T.; Ohtani, H.

    2013-12-01

    Magnetic reconnection is considered to play an important role in space phenomena such as substorm in the Earth's magnetosphere. It is well known that magnetic reconnection is controlled by microscopic kinetic mechanism. Frozen-in condition is broken due to particle kinetic effects and collisionless reconnection is triggered when current sheet is compressed as thin as ion kinetic scales under the influence of external driving flow. On the other hand configuration of the magnetic field leading to formation of diffusion region is determined in macroscopic scale and topological change after reconnection is also expressed in macroscopic scale. Thus magnetic reconnection is typical multi-scale phenomenon and microscopic and macroscopic physics are strongly coupled. Recently Horiuchi et al. developed an effective resistivity model based on particle-in-cell (PIC) simulation results obtained in study of collisionless driven reconnection and applied to a global magnetohydrodynamics (MHD) simulation of substorm in the Earth's magnetosphere. They showed reproduction of global behavior in substrom such as dipolarization and flux rope formation by global three dimensional MHD simulation. Usami et al. developed multi-hierarchy simulation model, in which macroscopic and microscopic physics are solved self-consistently and simultaneously. Based on the domain decomposition method, this model consists of three parts: a MHD algorithm for macroscopic global dynamics, a PIC algorithm for microscopic kinetic physics, and an interface algorithm to interlock macro and micro hierarchies. They verified the interface algorithm by simulation of plasma injection flow. In their latest work, this model was applied to collisionless reconnection in an open system and magnetic reconnection was successfully found. In this paper, we describe our approach to clarify multi-scale phenomena and report the current status. Our recent study about extension of the MHD domain to global system is presented. We

  5. Diagnosing Disaster Resilience of Communities as Multi-scale Complex Socio-ecological Systems

    Liu, Wei; Mochizuki, Junko; Keating, Adriana; Mechler, Reinhard; Williges, Keith; Hochrainer, Stefan

    2014-05-01

    Global environmental change, growing anthropogenic influence, and increasing globalisation of society have made it clear that disaster vulnerability and resilience of communities cannot be understood without knowledge on the broader social-ecological system in which they are embedded. We propose a framework for diagnosing community resilience to disasters, as a form of disturbance to social-ecological systems, with feedbacks from the local to the global scale. Inspired by iterative multi-scale analysis employed by Resilience Alliance, the related socio-ecological systems framework of Ostrom, and the sustainable livelihood framework, we developed a multi-tier framework for thinking of communities as multi-scale social-ecological systems and analyzing communities' disaster resilience and also general resilience. We highlight the cross-scale influences and feedbacks on communities that exist from lower (e.g., household) to higher (e.g., regional, national) scales. The conceptual framework is then applied to a real-world resilience assessment situation, to illustrate how key components of socio-ecological systems, including natural hazards, natural and man-made environment, and community capacities can be delineated and analyzed.

  6. Multi-Scale Factor Analysis of High-Dimensional Brain Signals

    Ting, Chee-Ming

    2017-05-18

    In this paper, we develop an approach to modeling high-dimensional networks with a large number of nodes arranged in a hierarchical and modular structure. We propose a novel multi-scale factor analysis (MSFA) model which partitions the massive spatio-temporal data defined over the complex networks into a finite set of regional clusters. To achieve further dimension reduction, we represent the signals in each cluster by a small number of latent factors. The correlation matrix for all nodes in the network are approximated by lower-dimensional sub-structures derived from the cluster-specific factors. To estimate regional connectivity between numerous nodes (within each cluster), we apply principal components analysis (PCA) to produce factors which are derived as the optimal reconstruction of the observed signals under the squared loss. Then, we estimate global connectivity (between clusters or sub-networks) based on the factors across regions using the RV-coefficient as the cross-dependence measure. This gives a reliable and computationally efficient multi-scale analysis of both regional and global dependencies of the large networks. The proposed novel approach is applied to estimate brain connectivity networks using functional magnetic resonance imaging (fMRI) data. Results on resting-state fMRI reveal interesting modular and hierarchical organization of human brain networks during rest.

  7. Network science landers for Mars

    Harri, A.M.; Marsal, O.; Lognonne, P.

    1999-01-01

    by the Mars Express Orbiter that is expected to be functional during the NetLander Mission's operational phase. Communication between the landers and the Earth would take place via a data relay onboard the Mars Express Orbiter. (C) 1999 COSPAR. Published by Elsevier Science Ltd.......The NetLander Mission will deploy four landers to the Martian surface. Each lander includes a network science payload with instrumentation for studying the interior of Mars, the atmosphere and the subsurface, as well as the ionospheric structure and geodesy. The NetLander Mission is the first......, ionospheric, geodetic measurements and ground penetrating radar mapping supported by panoramic images. The payloads also include entry phase measurements of the atmospheric vertical structure. The scientific data could be combined with simultaneous observations of the atmosphere and surface of Mars...

  8. Internal Audit Charter, Mar2018

    Jessica Perkins

    2018-03-02

    Mar 2, 2018 ... authorizes the Finance and Audit Committee to oversee IDRC's Internal ... reassignment, or dismissal of the Chief Audit Executive. ... Audit Executive's duties as the Senior Officer for disclosure pursuant to the Public Servants.

  9. Subsurface microbial habitats on Mars

    Boston, P. J.; Mckay, C. P.

    1991-01-01

    We developed scenarios for shallow and deep subsurface cryptic niches for microbial life on Mars. Such habitats could have considerably prolonged the persistence of life on Mars as surface conditions became increasingly inhospitable. The scenarios rely on geothermal hot spots existing below the near or deep subsurface of Mars. Recent advances in the comparatively new field of deep subsurface microbiology have revealed previously unsuspected rich aerobic and anaerobic microbal communities far below the surface of the Earth. Such habitats, protected from the grim surface conditions on Mars, could receive warmth from below and maintain water in its liquid state. In addition, geothermally or volcanically reduced gases percolating from below through a microbiologically active zone could provide the reducing power needed for a closed or semi-closed microbial ecosystem to thrive.

  10. Evacuated Airship for Mars Missions

    National Aeronautics and Space Administration — We propose to overcome some of the limitations of current technologies for Mars exploration and even extend current operational capabilities by introducing the...

  11. Is There Life on Mars?

    Allen, Bruce C.; Herreid, Clyde Freeman

    1998-01-01

    Presents a conflict scenario for a case study on whether there is evidence of past life on Mars. Includes details about the use of this case study in developing an interdisciplinary approach to scientific ethics. (DDR)

  12. Properties of cryobrines on Mars

    Möhlmann, D.; Thomsen, Kaj

    2011-01-01

    Brines, i.e. aqueous salty solutions, increasingly play a role in a better understanding of physics and chemistry (and eventually also putative biology) of the upper surface of Mars. Results of physico-chemical modeling and experimentally determined data to characterize properties of cryobrines...... of potential interest with respect to Mars are described. Eutectic diagrams, the related numerical eutectic values of composition and temperature, the water activity of Mars-relevant brines of sulfates, chlorides, perchlorides and carbonates, including related deliquescence relative humidity, are parameters...... and properties, which are described here in some detail. The results characterize conditions for liquid low-temperature brines ("cryobrines") to evolve and to exist, at least temporarily, on present Mars. (C) 2010 Elsevier Inc. All rights reserved....

  13. Launching to the Moon, Mars, and Beyond

    Sumrall, John P.

    2007-01-01

    America is returning to the Moon in preparation for the first human footprint on Mars, guided by the U.S. Vision for Space Exploration. This presentation will discuss NASA's mission today, the reasons for returning to the Moon and going to Mars, and how NASA will accomplish that mission. The primary goals of the Vision for Space Exploration are to finish the International Space Station, retire the Space Shuttle, and build the new spacecraft needed to return people to the Moon and go to Mars. Unlike the Apollo program of the 1960s, this phase of exploration will be a journey, not a race. In 1966, the NASA's budget was 4 percent of federal spending. Today, with 6/10 of 1 percent of the budget, NASA must incrementally develop the vehicles, infrastructure, technology, and organization to accomplish this goal. Fortunately, our knowledge and experience are greater than they were 40 years ago. NASA's goal is a return to the Moon by 2020. The Moon is the first step to America's exploration of Mars. Many questions about the Moon's history and how its history is linked to that of Earth remain even after the brief Apollo explorations of the 1960s and 1970s. This new venture will carry more explorers to more diverse landing sites with more capable tools and equipment. The Moon also will serve as a training ground in several respects before embarking on the longer, more perilous trip to Mars. The journeys to the Moon and Mars will require a variety of vehicles, including the Ares I Crew Launch Vehicle, the Ares V Cargo Launch Vehicle, the Orion Crew Exploration Vehicle, and the Lunar Surface Access Module. The architecture for the lunar missions will use one launch to ferry the crew into orbit on the Ares I and a second launch to orbit the lunar lander and the Earth Departure Stage to send the lander and crew vehicle to the Moon. In order to reach the Moon and Mars within a lifetime and within budget, NASA is building on proven hardware and decades of experience derived from

  14. Interactive 3D Mars Visualization

    Powell, Mark W.

    2012-01-01

    The Interactive 3D Mars Visualization system provides high-performance, immersive visualization of satellite and surface vehicle imagery of Mars. The software can be used in mission operations to provide the most accurate position information for the Mars rovers to date. When integrated into the mission data pipeline, this system allows mission planners to view the location of the rover on Mars to 0.01-meter accuracy with respect to satellite imagery, with dynamic updates to incorporate the latest position information. Given this information so early in the planning process, rover drivers are able to plan more accurate drive activities for the rover than ever before, increasing the execution of science activities significantly. Scientifically, this 3D mapping information puts all of the science analyses to date into geologic context on a daily basis instead of weeks or months, as was the norm prior to this contribution. This allows the science planners to judge the efficacy of their previously executed science observations much more efficiently, and achieve greater science return as a result. The Interactive 3D Mars surface view is a Mars terrain browsing software interface that encompasses the entire region of exploration for a Mars surface exploration mission. The view is interactive, allowing the user to pan in any direction by clicking and dragging, or to zoom in or out by scrolling the mouse or touchpad. This set currently includes tools for selecting a point of interest, and a ruler tool for displaying the distance between and positions of two points of interest. The mapping information can be harvested and shared through ubiquitous online mapping tools like Google Mars, NASA WorldWind, and Worldwide Telescope.

  15. Mars and Men

    Muehlberger, W.

    2001-01-01

    Wherever mankind travels in space, people will always be preceded by unmanned probes that will provide the first bit of information. But there comes a time when we've learned all we can by unmanned vehicles. Man comes on the scene and makes the decisions about what is most valuable to us here, and that makes space into a new laboratory. Photography plays a vital role in all that John Glenn, in 'The View from Space'. Why do you take a photograph? We took a lot of documentation pictures because we were supposed to. But a lot of photographs were taken on instinct things you can't predict you're going to see or that are going to impress you. You say, 'Now I've got to take a picture of that" or "Look at the way that is positioned' or' Look at the way the sun is shining on that." Those 'stand-back' pictures were taken with aesthetics in mind, to capture and document the venture itself." Eugene Cernan in 'The View from Space'. The Apollo mode for a Science Support Room in Mission Control will not work for Mars. The time delay makes it nearly useless. Our team was available for instantaneous reaction and assistance to the crew on EVA. Therefore the Science Support Team has to be on Mars! The crew that went out the day before will do the supporting. They will hand off to each other for the next EVA. They will send a daily report back to Earth as to what was accomplished, problems that need resolution, supporting video, data, etc. etc. In Apollo, that was the role of my "Tiger Team," who sat in Gene Krantz' office watching and listening but having no role for directly helping the Back Room. They wrote a summary of the EVA, what was accomplished, what got omitted that was important to insert into the next EVA. It was distributed throughout Mission Control- especially to the Big Brass, Flight Director, and the CapCom.

  16. Variational multiscale models for charge transport.

    Wei, Guo-Wei; Zheng, Qiong; Chen, Zhan; Xia, Kelin

    2012-01-01

    This work presents a few variational multiscale models for charge transport in complex physical, chemical and biological systems and engineering devices, such as fuel cells, solar cells, battery cells, nanofluidics, transistors and ion channels. An essential ingredient of the present models, introduced in an earlier paper (Bulletin of Mathematical Biology, 72, 1562-1622, 2010), is the use of differential geometry theory of surfaces as a natural means to geometrically separate the macroscopic domain from the microscopic domain, meanwhile, dynamically couple discrete and continuum descriptions. Our main strategy is to construct the total energy functional of a charge transport system to encompass the polar and nonpolar free energies of solvation, and chemical potential related energy. By using the Euler-Lagrange variation, coupled Laplace-Beltrami and Poisson-Nernst-Planck (LB-PNP) equations are derived. The solution of the LB-PNP equations leads to the minimization of the total free energy, and explicit profiles of electrostatic potential and densities of charge species. To further reduce the computational complexity, the Boltzmann distribution obtained from the Poisson-Boltzmann (PB) equation is utilized to represent the densities of certain charge species so as to avoid the computationally expensive solution of some Nernst-Planck (NP) equations. Consequently, the coupled Laplace-Beltrami and Poisson-Boltzmann-Nernst-Planck (LB-PBNP) equations are proposed for charge transport in heterogeneous systems. A major emphasis of the present formulation is the consistency between equilibrium LB-PB theory and non-equilibrium LB-PNP theory at equilibrium. Another major emphasis is the capability of the reduced LB-PBNP model to fully recover the prediction of the LB-PNP model at non-equilibrium settings. To account for the fluid impact on the charge transport, we derive coupled Laplace-Beltrami, Poisson-Nernst-Planck and Navier-Stokes equations from the variational principle

  17. Variational multiscale models for charge transport

    Wei, Guo-Wei; Zheng, Qiong; Chen, Zhan; Xia, Kelin

    2012-01-01

    This work presents a few variational multiscale models for charge transport in complex physical, chemical and biological systems and engineering devices, such as fuel cells, solar cells, battery cells, nanofluidics, transistors and ion channels. An essential ingredient of the present models, introduced in an earlier paper (Bulletin of Mathematical Biology, 72, 1562-1622, 2010), is the use of differential geometry theory of surfaces as a natural means to geometrically separate the macroscopic domain from the microscopic domain, meanwhile, dynamically couple discrete and continuum descriptions. Our main strategy is to construct the total energy functional of a charge transport system to encompass the polar and nonpolar free energies of solvation, and chemical potential related energy. By using the Euler-Lagrange variation, coupled Laplace-Beltrami and Poisson-Nernst-Planck (LB-PNP) equations are derived. The solution of the LB-PNP equations leads to the minimization of the total free energy, and explicit profiles of electrostatic potential and densities of charge species. To further reduce the computational complexity, the Boltzmann distribution obtained from the Poisson-Boltzmann (PB) equation is utilized to represent the densities of certain charge species so as to avoid the computationally expensive solution of some Nernst-Planck (NP) equations. Consequently, the coupled Laplace-Beltrami and Poisson-Boltzmann-Nernst-Planck (LB-PBNP) equations are proposed for charge transport in heterogeneous systems. A major emphasis of the present formulation is the consistency between equilibrium LB-PB theory and non-equilibrium LB-PNP theory at equilibrium. Another major emphasis is the capability of the reduced LB-PBNP model to fully recover the prediction of the LB-PNP model at non-equilibrium settings. To account for the fluid impact on the charge transport, we derive coupled Laplace-Beltrami, Poisson-Nernst-Planck and Navier-Stokes equations from the variational principle

  18. Secular Climate Change on Mars: An Update Using MSL Pressure Data

    Haberle, R. M.; Gomez-Elvira, J.; Juarez, M. de la Torre; Harri, A.-M.; Hollingsworth, J. L.; Kahanpaa, H.; Kahre, M. A.; Lemmon, M.; Martin-Torres, F. J.; Mischna, M.; hide

    2013-01-01

    The South Polar Residual Cap (SPRC) on Mars is an icy reservoir of CO2. If all the CO2 trapped in the SPRC were released to the atmosphere the mean annual global surface pressure would rise by approx. 20 Pa. Repeated MOC and HiRISE imaging of scarp retreat rates within the SPRC have led to the suggestion that the SPRC is losing mass. Estimates for the loss rate vary between 0.5 Pa per Mars Deacde to 13 Pa per Mars Decade. Assuming 80% of this loss goes directly to the atmosphere, and that the loss is monotonic, the global annual mean surface pressure should have increased between approx. 1-20 Pa since the Viking mission (19 Mars years ago).

  19. Mars exploration study workshop 2

    Duke, Michael B.; Budden, Nancy Ann

    1993-11-01

    A year-long NASA-wide study effort has led to the development of an innovative strategy for the human exploration of Mars. The latest Mars Exploration Study Workshop 2 advanced a design reference mission (DRM) that significantly reduces the perceived high costs, complex infrastructure, and long schedules associated with previous Mars scenarios. This surface-oriented philosophy emphasizes the development of high-leveraging surface technologies in lieu of concentrating exclusively on space transportation technologies and development strategies. As a result of the DRM's balanced approach to mission and crew risk, element commonality, and technology development, human missions to Mars can be accomplished without the need for complex assembly operations in low-Earth orbit. This report, which summarizes the Mars Exploration Study Workshop held at the Ames Research Center on May 24-25, 1993, provides an overview of the status of the Mars Exploration Study, material presented at the workshop, and discussions of open items being addressed by the study team. The workshop assembled three teams of experts to discuss cost, dual-use technology, and international involvement, and to generate a working group white paper addressing these issues. The three position papers which were generated are included in section three of this publication.

  20. RBF Multiscale Collocation for Second Order Elliptic Boundary Value Problems

    Farrell, Patricio; Wendland, Holger

    2013-01-01

    In this paper, we discuss multiscale radial basis function collocation methods for solving elliptic partial differential equations on bounded domains. The approximate solution is constructed in a multilevel fashion, each level using compactly

  1. A multiscale mortar multipoint flux mixed finite element method

    Wheeler, Mary Fanett; Xue, Guangri; Yotov, Ivan

    2012-01-01

    In this paper, we develop a multiscale mortar multipoint flux mixed finite element method for second order elliptic problems. The equations in the coarse elements (or subdomains) are discretized on a fine grid scale by a multipoint flux mixed finite

  2. Fast Multiscale Reservoir Simulations using POD-DEIM Model Reduction

    Ghasemi, Mohammadreza; Yang, Yanfang; Gildin, Eduardo; Efendiev, Yalchin R.; Calo, Victor M.

    2015-01-01

    snapshots are inexpensively computed using local model reduction techniques based on Generalized Multiscale Finite Element Method (GMsFEM) which provides (1) a hierarchical approximation of snapshot vectors (2) adaptive computations by using coarse grids (3

  3. Multi-Scale Simulation of High Energy Density Ionic Liquids

    Voth, Gregory A

    2007-01-01

    The focus of this AFOSR project was the molecular dynamics (MD) simulation of ionic liquid structure, dynamics, and interfacial properties, as well as multi-scale descriptions of these novel liquids (e.g...

  4. Multi-scale modeling strategies in materials science—The ...

    Unknown

    Multi-scale models; quasicontinuum method; finite elements. 1. Introduction ... boundary with external stresses, and the interaction of a lattice dislocation with a grain ..... mum value of se over the elements that touch node α. The acceleration of ...

  5. Lifetime statistics of quantum chaos studied by a multiscale analysis

    Di Falco, A.; Krauss, T. F.; Fratalocchi, Andrea

    2012-01-01

    on a silicon-on-insulator substrate. We calculate resonances through a multiscale procedure that combines energy landscape analysis and wavelet transforms. Experimental data is found to follow the universal predictions arising from random matrix theory

  6. Randomized Oversampling for Generalized Multiscale Finite Element Methods

    Calo, Victor M.; Efendiev, Yalchin R.; Galvis, Juan; Li, Guanglian

    2016-01-01

    boundary conditions defined in a domain larger than the target region. Furthermore, we perform an eigenvalue decomposition in this small space. We study the application of randomized sampling for GMsFEM in conjunction with adaptivity, where local multiscale

  7. Toward the multiscale nature of stress corrosion cracking

    Xiaolong Liu

    2018-02-01

    Full Text Available This article reviews the multiscale nature of stress corrosion cracking (SCC observed by high-resolution characterizations in austenite stainless steels and Ni-base superalloys in light water reactors (including boiling water reactors, pressurized water reactors, and supercritical water reactors with related opinions. A new statistical summary and comparison of observed degradation phenomena at different length scales is included. The intrinsic causes of this multiscale nature of SCC are discussed based on existing evidence and related opinions, ranging from materials theory to practical processing technologies. Questions of interest are then discussed to improve bottom-up understanding of the intrinsic causes. Last, a multiscale modeling and simulation methodology is proposed as a promising interdisciplinary solution to understand the intrinsic causes of the multiscale nature of SCC in light water reactors, based on a review of related supporting application evidence.

  8. Multiscale model reduction for shale gas transport in fractured media

    Akkutlu, I. Y.; Efendiev, Yalchin R.; Vasilyeva, Maria

    2016-01-01

    fracture distributions on an unstructured grid; (2) develop GMsFEM for nonlinear flows; and (3) develop online basis function strategies to adaptively improve the convergence. The number of multiscale basis functions in each coarse region represents

  9. Distributed Multiscale Data Analysis and Processing for Sensor Networks

    Wagner, Raymond; Sarvotham, Shriram; Choi, Hyeokho; Baraniuk, Richard

    2005-01-01

    .... Second, the communication overhead of multiscale algorithms can become prohibitive. In this paper, we take a first step in addressing both shortcomings by introducing two new distributed multiresolution transforms...

  10. Examining Multiscale Movement Coordination in Collaborative Problem Solving

    Wiltshire, Travis; Steffensen, Sune Vork

    2017-01-01

    During collaborative problem solving (CPS), coordination occurs at different spatial and temporal scales. This multiscale coordination should, at least on some scales, play a functional role in facilitating effective collaboration outcomes. To evaluate this, we conducted a study of computer...

  11. Novel multiscale modeling tool applied to Pseudomonas aeruginosa biofilm formation.

    Matthew B Biggs

    Full Text Available Multiscale modeling is used to represent biological systems with increasing frequency and success. Multiscale models are often hybrids of different modeling frameworks and programming languages. We present the MATLAB-NetLogo extension (MatNet as a novel tool for multiscale modeling. We demonstrate the utility of the tool with a multiscale model of Pseudomonas aeruginosa biofilm formation that incorporates both an agent-based model (ABM and constraint-based metabolic modeling. The hybrid model correctly recapitulates oxygen-limited biofilm metabolic activity and predicts increased growth rate via anaerobic respiration with the addition of nitrate to the growth media. In addition, a genome-wide survey of metabolic mutants and biofilm formation exemplifies the powerful analyses that are enabled by this computational modeling tool.

  12. Novel multiscale modeling tool applied to Pseudomonas aeruginosa biofilm formation.

    Biggs, Matthew B; Papin, Jason A

    2013-01-01

    Multiscale modeling is used to represent biological systems with increasing frequency and success. Multiscale models are often hybrids of different modeling frameworks and programming languages. We present the MATLAB-NetLogo extension (MatNet) as a novel tool for multiscale modeling. We demonstrate the utility of the tool with a multiscale model of Pseudomonas aeruginosa biofilm formation that incorporates both an agent-based model (ABM) and constraint-based metabolic modeling. The hybrid model correctly recapitulates oxygen-limited biofilm metabolic activity and predicts increased growth rate via anaerobic respiration with the addition of nitrate to the growth media. In addition, a genome-wide survey of metabolic mutants and biofilm formation exemplifies the powerful analyses that are enabled by this computational modeling tool.

  13. Mars aqueous chemistry experiment

    Clark, Benton C.; Mason, Larry W.

    1994-06-01

    Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. The second year of the MACE project has shown significant progress in two major areas. MACE Instrument concept definition is a baseline design that has been generated for the complete MACE instrument, including definition of analysis modes, mass estimates and thermal model. The design includes multiple reagent reservoirs, 10 discrete analysis cells, sample manipulation capability, and thermal control. The MACE Measurement subsystems development progress is reported regarding measurement capabilities for aqueous ion sensing, evolved gas sensing, solution conductivity measurement, reagent addition (titration) capabilities, and optical sensing of suspended particles.

  14. Mars aqueous chemistry experiment

    Clark, Benton C.; Mason, Larry W.

    1994-01-01

    Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. The second year of the MACE project has shown significant progress in two major areas. MACE Instrument concept definition is a baseline design that has been generated for the complete MACE instrument, including definition of analysis modes, mass estimates and thermal model. The design includes multiple reagent reservoirs, 10 discrete analysis cells, sample manipulation capability, and thermal control. The MACE Measurement subsystems development progress is reported regarding measurement capabilities for aqueous ion sensing, evolved gas sensing, solution conductivity measurement, reagent addition (titration) capabilities, and optical sensing of suspended particles.

  15. Simple autonomous Mars walker

    Larimer, Stanley J.; Lisec, Thomas R.; Spiessbach, Andrew J.

    1989-01-01

    Under a contract with NASA's Jet Propulsion Laboratory, Martin Marietta has developed several alternative rover concepts for unmanned exploration of the planet Mars. One of those concepts, the 'Walking Beam', is the subject of this paper. This concept was developed with the goal of achieving many of the capabilities of more sophisticated articulated-leg walkers with a much simpler, more robust, less computationally demanding and more power efficient design. It consists of two large-base tripods nested one within the other which alternately translate with respect to each other along a 5-meter beam to propel the vehicle. The semiautonomous navigation system relies on terrain geometry sensors and tacticle feedback from each foot to autonomously select a path which avoids hazards along a route designated from earth. Both mobility and navigation features of this concept are discussed including a top-level description of the vehicle's physical characteristics, deployment strategy, mobility elements, sensor suite, theory of operation, navigation and control processes, and estimated performance.

  16. Mars manned fusion spaceship

    Hedrick, J.; Buchholtz, B.; Ward, P.; Freuh, J.; Jensen, E.

    1991-01-01

    Fusion Propulsion has an enormous potential for space exploration in the near future. In the twenty-first century, a usable and efficient fusion rocket will be developed and in use. Because of the great distance between other planets and Earth, efficient use of time, fuel, and payload is essential. A nuclear spaceship would provide greater fuel efficiency, less travel time, and a larger payload. Extended missions would give more time for research, experiments, and data acquisition. With the extended mission time, a need for an artificial environment exists. The topics of magnetic fusion propulsion, living modules, artificial gravity, mass distribution, space connection, and orbital transfer to Mars are discussed. The propulsion system is a magnetic fusion reactor based on a tandem mirror design. This allows a faster, shorter trip time and a large thrust to weight ratio. The fuel proposed is a mixture of deuterium and helium. Helium can be obtained from lunar mining. There will be minimal external radiation from the reactor resulting in a safe, efficient propulsion system

  17. Effects of Perchlorate on Organic Molecules under Simulated Mars Conditions

    Carrier, B. L.; Kounaves, S. P.

    2014-12-01

    Perchlorate (ClO4-) was discovered in the northern polar region of Mars by the Mars Phoenix Lander in 2008 and has also been recently detected by the Curiosity Rover in Gale Crater [1,2]. Perchlorate has also been shown to be formed under current Mars conditions via the oxidation of mineral chlorides, further supporting the theory that perchlorate is present globally on Mars [3]. The discovery of perchlorate on Mars has raised important questions about the effects of perchlorate on the survival and detection of organic molecules. Although it has been shown that pyrolysis in the presence of perchlorate results in the alteration or destruction of organic molecules [4], few studies have been conducted on the potential effects of perchlorate on organic molecules under martian surface conditions. Although perchlorate is typically inert under Mars-typical temperatures [5], perchlorate does absorb high energy UV radiation, and has been shown to decompose to form reactive oxychlorine species such as chlorite (ClO2-) when exposed to martian conditions including UV or ionizing radiation [6,7]. Here we investigate the effects of perchlorate on the organic molecules tryptophan, benzoic acid and mellitic acid in order to determine how perchlorate may alter these compounds under Mars conditions. Experiments are performed in a Mars Simulation Chamber (MSC) capable of reproducing the temperature, pressure, atmospheric composition and UV flux found on Mars. Soil simulants are prepared consisting of SiO2 and each organic, as well as varying concentrations of perchlorate salts, and exposed in the MSC. Subsequent to exposure in the MSC samples are leached and the leachate analyzed by HPLC and LC-MS to determine the degree of degradation of the original organic and the identity of any potential decomposition products formed by oxidation or chlorination. References: [1] Kounaves et al., J. Geophys. Res. Planets, Vol. 115, p. E00E10, 2010 [2] Glavin et al., J. Geophys. Res. Planets, Vol

  18. An approach to multiscale modelling with graph grammars.

    Ong, Yongzhi; Streit, Katarína; Henke, Michael; Kurth, Winfried

    2014-09-01

    Functional-structural plant models (FSPMs) simulate biological processes at different spatial scales. Methods exist for multiscale data representation and modification, but the advantages of using multiple scales in the dynamic aspects of FSPMs remain unclear. Results from multiscale models in various other areas of science that share fundamental modelling issues with FSPMs suggest that potential advantages do exist, and this study therefore aims to introduce an approach to multiscale modelling in FSPMs. A three-part graph data structure and grammar is revisited, and presented with a conceptual framework for multiscale modelling. The framework is used for identifying roles, categorizing and describing scale-to-scale interactions, thus allowing alternative approaches to model development as opposed to correlation-based modelling at a single scale. Reverse information flow (from macro- to micro-scale) is catered for in the framework. The methods are implemented within the programming language XL. Three example models are implemented using the proposed multiscale graph model and framework. The first illustrates the fundamental usage of the graph data structure and grammar, the second uses probabilistic modelling for organs at the fine scale in order to derive crown growth, and the third combines multiscale plant topology with ozone trends and metabolic network simulations in order to model juvenile beech stands under exposure to a toxic trace gas. The graph data structure supports data representation and grammar operations at multiple scales. The results demonstrate that multiscale modelling is a viable method in FSPM and an alternative to correlation-based modelling. Advantages and disadvantages of multiscale modelling are illustrated by comparisons with single-scale implementations, leading to motivations for further research in sensitivity analysis and run-time efficiency for these models.

  19. Long-term Stable Conservative Multiscale Methods for Vortex Flows

    2017-10-31

    Computing Department, Florida State (January 2016) - L. Rebholz, SIAM Southeast 2016, Special session on Recent advances in fluid flow and...Multiscale Methods for Vortex Flows (x) Material has been given an OPSEC review and it has been determined to be non sensitive and, except for...distribution is unlimited. UU UU UU UU 31-10-2017 1-Aug-2014 31-Jul-2017 Final Report: Long-term Stable Conservative Multiscale Methods for Vortex Flows

  20. RFP for the Auroral Multiscale Midex (AMM) Mission star tracker

    Riis, Troels; Betto, Maurizio; Jørgensen, John Leif

    1999-01-01

    This document is in response to the John Hopkins University - Applied Physics Laboratory RFP for the Auroral Multiscale Midex Mission star tracker.It describes the functionality, the requirements and the performance of the ASC Star Tracker.......This document is in response to the John Hopkins University - Applied Physics Laboratory RFP for the Auroral Multiscale Midex Mission star tracker.It describes the functionality, the requirements and the performance of the ASC Star Tracker....

  1. MUSIC: MUlti-Scale Initial Conditions

    Hahn, Oliver; Abel, Tom

    2013-11-01

    MUSIC generates multi-scale initial conditions with multiple levels of refinements for cosmological ‘zoom-in’ simulations. The code uses an adaptive convolution of Gaussian white noise with a real-space transfer function kernel together with an adaptive multi-grid Poisson solver to generate displacements and velocities following first- (1LPT) or second-order Lagrangian perturbation theory (2LPT). MUSIC achieves rms relative errors of the order of 10-4 for displacements and velocities in the refinement region and thus improves in terms of errors by about two orders of magnitude over previous approaches. In addition, errors are localized at coarse-fine boundaries and do not suffer from Fourier space-induced interference ringing.

  2. Multi-scale modeling of composites

    Azizi, Reza

    A general method to obtain the homogenized response of metal-matrix composites is developed. It is assumed that the microscopic scale is sufficiently small compared to the macroscopic scale such that the macro response does not affect the micromechanical model. Therefore, the microscopic scale......-Mandel’s energy principle is used to find macroscopic operators based on micro-mechanical analyses using the finite element method under generalized plane strain condition. A phenomenologically macroscopic model for metal matrix composites is developed based on constitutive operators describing the elastic...... to plastic deformation. The macroscopic operators found, can be used to model metal matrix composites on the macroscopic scale using a hierarchical multi-scale approach. Finally, decohesion under tension and shear loading is studied using a cohesive law for the interface between matrix and fiber....

  3. Quantifying multiscale inefficiency in electricity markets

    Uritskaya, Olga Y. [Department of Economics, University of Calgary, Calgary, Alberta T2N 1N4, and Department of Economics and Management, St. Petersburg Polytechnic University, St. Petersburg (Russian Federation); Serletis, Apostolos [Department of Economics, University of Calgary, Calgary, Alberta (Canada)

    2008-11-15

    One of the basic features of efficient markets is the absence of correlations between price increments over any time scale leading to random walk-type behavior of prices. In this paper, we propose a new approach for measuring deviations from the efficient market state based on an analysis of scale-dependent fractal exponent characterizing correlations at different time scales. The approach is applied to two electricity markets, Alberta and Mid Columbia (Mid-C), as well as to the AECO Alberta natural gas market (for purposes of providing a comparison between storable and non-storable commodities). We show that price fluctuations in all studied markets are not efficient, with electricity prices exhibiting complex multiscale correlated behavior not captured by monofractal methods used in previous studies. (author)

  4. On multiscale moving contact line theory.

    Li, Shaofan; Fan, Houfu

    2015-07-08

    In this paper, a multiscale moving contact line (MMCL) theory is presented and employed to simulate liquid droplet spreading and capillary motion. The proposed MMCL theory combines a coarse-grained adhesive contact model with a fluid interface membrane theory, so that it can couple molecular scale adhesive interaction and surface tension with hydrodynamics of microscale flow. By doing so, the intermolecular force, the van der Waals or double layer force, separates and levitates the liquid droplet from the supporting solid substrate, which avoids the shear stress singularity caused by the no-slip condition in conventional hydrodynamics theory of moving contact line. Thus, the MMCL allows the difference of the surface energies and surface stresses to drive droplet spreading naturally. To validate the proposed MMCL theory, we have employed it to simulate droplet spreading over various elastic substrates. The numerical simulation results obtained by using MMCL are in good agreement with the molecular dynamics results reported in the literature.

  5. Numerical methods and analysis of multiscale problems

    Madureira, Alexandre L

    2017-01-01

    This book is about numerical modeling of multiscale problems, and introduces several asymptotic analysis and numerical techniques which are necessary for a proper approximation of equations that depend on different physical scales. Aimed at advanced undergraduate and graduate students in mathematics, engineering and physics – or researchers seeking a no-nonsense approach –, it discusses examples in their simplest possible settings, removing mathematical hurdles that might hinder a clear understanding of the methods. The problems considered are given by singular perturbed reaction advection diffusion equations in one and two-dimensional domains, partial differential equations in domains with rough boundaries, and equations with oscillatory coefficients. This work shows how asymptotic analysis can be used to develop and analyze models and numerical methods that are robust and work well for a wide range of parameters.

  6. Quantifying multiscale inefficiency in electricity markets

    Uritskaya, Olga Y.; Serletis, Apostolos

    2008-01-01

    One of the basic features of efficient markets is the absence of correlations between price increments over any time scale leading to random walk-type behavior of prices. In this paper, we propose a new approach for measuring deviations from the efficient market state based on an analysis of scale-dependent fractal exponent characterizing correlations at different time scales. The approach is applied to two electricity markets, Alberta and Mid Columbia (Mid-C), as well as to the AECO Alberta natural gas market (for purposes of providing a comparison between storable and non-storable commodities). We show that price fluctuations in all studied markets are not efficient, with electricity prices exhibiting complex multiscale correlated behavior not captured by monofractal methods used in previous studies. (author)

  7. Multiscale modeling of three-dimensional genome

    Zhang, Bin; Wolynes, Peter

    The genome, the blueprint of life, contains nearly all the information needed to build and maintain an entire organism. A comprehensive understanding of the genome is of paramount interest to human health and will advance progress in many areas, including life sciences, medicine, and biotechnology. The overarching goal of my research is to understand the structure-dynamics-function relationships of the human genome. In this talk, I will be presenting our efforts in moving towards that goal, with a particular emphasis on studying the three-dimensional organization, the structure of the genome with multi-scale approaches. Specifically, I will discuss the reconstruction of genome structures at both interphase and metaphase by making use of data from chromosome conformation capture experiments. Computationally modeling of chromatin fiber at atomistic level from first principles will also be presented as our effort for studying the genome structure from bottom up.

  8. Multiscale simulation approach for battery production systems

    Schönemann, Malte

    2017-01-01

    Addressing the challenge of improving battery quality while reducing high costs and environmental impacts of the production, this book presents a multiscale simulation approach for battery production systems along with a software environment and an application procedure. Battery systems are among the most important technologies of the 21st century since they are enablers for the market success of electric vehicles and stationary energy storage solutions. However, the performance of batteries so far has limited possible applications. Addressing this challenge requires an interdisciplinary understanding of dynamic cause-effect relationships between processes, equipment, materials, and environmental conditions. The approach in this book supports the integrated evaluation of improvement measures and is usable for different planning horizons. It is applied to an exemplary battery cell production and module assembly in order to demonstrate the effectiveness and potential benefits of the simulation.

  9. Sequence stratigraphy on an early wet Mars

    Barker, Donald C.; Bhattacharya, Janok P.

    2018-02-01

    The evolution of Mars as a water-bearing body is of considerable interest for the understanding of its early history and evolution. The principles of terrestrial sequence stratigraphy provide a useful conceptual framework to hypothesize about the stratigraphic history of the planets northern plains. We present a model based on the hypothesized presence of an early ocean and the accumulation of lowland sediments eroded from highland terrain during the time of the valley networks and later outflow channels. Ancient, global environmental changes, induced by a progressively cooling climate would have led to a protracted loss of surface and near surface water from low-latitudes and eventual cold-trapping at higher latitudes - resulting in a unique and prolonged, perpetual forced regression within basins and lowland depositional environments. The Messinian Salinity Crisis (MSC) serves as a potential terrestrial analogue of the depositional and environmental consequences relating to the progressive removal of large standing bodies of water. We suggest that the evolution of similar conditions on Mars would have led to the emplacement of diagnostic sequences of deposits and regional scale unconformities, consistent with intermittent resurfacing of the northern plains and the progressive loss of an early ocean by the end of the Hesperian era.

  10. Results from Navigator GPS Flight Testing for the Magnetospheric MultiScale Mission

    Lulich, Tyler D.; Bamford, William A.; Wintermitz, Luke M. B.; Price, Samuel R.

    2012-01-01

    The recent delivery of the first Goddard Space Flight Center (GSFC) Navigator Global Positioning System (GPS) receivers to the Magnetospheric MultiScale (MMS) mission spacecraft is a high water mark crowning a decade of research and development in high-altitude space-based GPS. Preceding MMS delivery, the engineering team had developed receivers to support multiple missions and mission studies, such as Low Earth Orbit (LEO) navigation for the Global Precipitation Mission (GPM), above the constellation navigation for the Geostationary Operational Environmental Satellite (GOES) proof-of-concept studies, cis-Lunar navigation with rapid re-acquisition during re-entry for the Orion Project and an orbital demonstration on the Space Shuttle during the Hubble Servicing Mission (HSM-4).

  11. Hybrid Multiscale Finite Volume method for multiresolution simulations of flow and reactive transport in porous media

    Barajas-Solano, D. A.; Tartakovsky, A. M.

    2017-12-01

    We present a multiresolution method for the numerical simulation of flow and reactive transport in porous, heterogeneous media, based on the hybrid Multiscale Finite Volume (h-MsFV) algorithm. The h-MsFV algorithm allows us to couple high-resolution (fine scale) flow and transport models with lower resolution (coarse) models to locally refine both spatial resolution and transport models. The fine scale problem is decomposed into various "local'' problems solved independently in parallel and coordinated via a "global'' problem. This global problem is then coupled with the coarse model to strictly ensure domain-wide coarse-scale mass conservation. The proposed method provides an alternative to adaptive mesh refinement (AMR), due to its capacity to rapidly refine spatial resolution beyond what's possible with state-of-the-art AMR techniques, and the capability to locally swap transport models. We illustrate our method by applying it to groundwater flow and reactive transport of multiple species.

  12. Hybrid stochastic simplifications for multiscale gene networks

    Debussche Arnaud

    2009-09-01

    Full Text Available Abstract Background Stochastic simulation of gene networks by Markov processes has important applications in molecular biology. The complexity of exact simulation algorithms scales with the number of discrete jumps to be performed. Approximate schemes reduce the computational time by reducing the number of simulated discrete events. Also, answering important questions about the relation between network topology and intrinsic noise generation and propagation should be based on general mathematical results. These general results are difficult to obtain for exact models. Results We propose a unified framework for hybrid simplifications of Markov models of multiscale stochastic gene networks dynamics. We discuss several possible hybrid simplifications, and provide algorithms to obtain them from pure jump processes. In hybrid simplifications, some components are discrete and evolve by jumps, while other components are continuous. Hybrid simplifications are obtained by partial Kramers-Moyal expansion 123 which is equivalent to the application of the central limit theorem to a sub-model. By averaging and variable aggregation we drastically reduce simulation time and eliminate non-critical reactions. Hybrid and averaged simplifications can be used for more effective simulation algorithms and for obtaining general design principles relating noise to topology and time scales. The simplified models reproduce with good accuracy the stochastic properties of the gene networks, including waiting times in intermittence phenomena, fluctuation amplitudes and stationary distributions. The methods are illustrated on several gene network examples. Conclusion Hybrid simplifications can be used for onion-like (multi-layered approaches to multi-scale biochemical systems, in which various descriptions are used at various scales. Sets of discrete and continuous variables are treated with different methods and are coupled together in a physically justified approach.

  13. MULTISCALE DYNAMICS OF SOLAR MAGNETIC STRUCTURES

    Uritsky, Vadim M.; Davila, Joseph M.

    2012-01-01

    Multiscale topological complexity of the solar magnetic field is among the primary factors controlling energy release in the corona, including associated processes in the photospheric and chromospheric boundaries. We present a new approach for analyzing multiscale behavior of the photospheric magnetic flux underlying these dynamics as depicted by a sequence of high-resolution solar magnetograms. The approach involves two basic processing steps: (1) identification of timing and location of magnetic flux origin and demise events (as defined by DeForest et al.) by tracking spatiotemporal evolution of unipolar and bipolar photospheric regions, and (2) analysis of collective behavior of the detected magnetic events using a generalized version of the Grassberger-Procaccia correlation integral algorithm. The scale-free nature of the developed algorithms makes it possible to characterize the dynamics of the photospheric network across a wide range of distances and relaxation times. Three types of photospheric conditions are considered to test the method: a quiet photosphere, a solar active region (NOAA 10365) in a quiescent non-flaring state, and the same active region during a period of M-class flares. The results obtained show (1) the presence of a topologically complex asymmetrically fragmented magnetic network in the quiet photosphere driven by meso- and supergranulation, (2) the formation of non-potential magnetic structures with complex polarity separation lines inside the active region, and (3) statistical signatures of canceling bipolar magnetic structures coinciding with flaring activity in the active region. Each of these effects can represent an unstable magnetic configuration acting as an energy source for coronal dissipation and heating.

  14. Multiscale sampling model for motion integration.

    Sherbakov, Lena; Yazdanbakhsh, Arash

    2013-09-30

    Biologically plausible strategies for visual scene integration across spatial and temporal domains continues to be a challenging topic. The fundamental question we address is whether classical problems in motion integration, such as the aperture problem, can be solved in a model that samples the visual scene at multiple spatial and temporal scales in parallel. We hypothesize that fast interareal connections that allow feedback of information between cortical layers are the key processes that disambiguate motion direction. We developed a neural model showing how the aperture problem can be solved using different spatial sampling scales between LGN, V1 layer 4, V1 layer 6, and area MT. Our results suggest that multiscale sampling, rather than feedback explicitly, is the key process that gives rise to end-stopped cells in V1 and enables area MT to solve the aperture problem without the need for calculating intersecting constraints or crafting intricate patterns of spatiotemporal receptive fields. Furthermore, the model explains why end-stopped cells no longer emerge in the absence of V1 layer 6 activity (Bolz & Gilbert, 1986), why V1 layer 4 cells are significantly more end-stopped than V1 layer 6 cells (Pack, Livingstone, Duffy, & Born, 2003), and how it is possible to have a solution to the aperture problem in area MT with no solution in V1 in the presence of driving feedback. In summary, while much research in the field focuses on how a laminar architecture can give rise to complicated spatiotemporal receptive fields to solve problems in the motion domain, we show that one can reframe motion integration as an emergent property of multiscale sampling achieved concurrently within lamina and across multiple visual areas.

  15. Humans to Mars: The Greatest Adventure in Human History

    Levine, Joel S.; Schild,Rudy

    2011-01-01

    The reasons for a human mission to Mars are many and include (1) World technological leadership, (2) Enhanced national security, (3) Enhanced economic vitality, (4) The human urge to explore new and distant frontiers, (5) Scientific discovery (how did Mars evolve from an early Earth-like, hospitable planet to its present inhospitable state? Is there life on Mars?) (6) Inspiring the American public and the next generation of scientists and engineers (following the launch of Sputnik I by the USSR on October 4, 1957, the U. S. and the rest of the world witnessed a significant increase in the number of students going into science and engineering), (7) Develop new technologies for potential non-space spin-off applications, and, (8) Enhanced national prestige, etc. Other reasons for colonizing the Red Planet are more catastrophic in nature, including Mars as a safe haven for the survival of the human species in the event of an impact with a large asteroid (remember the demise of the dinosaurs 65-million years as a result of an asteroid impact!). Some have also suggested that the colonization of Mars may be a solution to the global exponential population explosion on our planet! A human mission to and the colonization of the Red Planet requires multi-disciplined expertise in many areas including engineering, technology, science, human health and medicine and the human psychological and behavior. To capture the relevant areas of needed expertise, we have invited a group of more than 70 U. S. and foreign experts in these areas, including astronauts, scientists, engineers, technologists, medical doctors, psychologists and economists to share their views and thoughts on a human mission to Mars.

  16. Mars Analytical Microimager

    Batory, Krzysztof J.; Govindjee; Andersen, Dale; Presley, John; Lucas, John M.; Sears, S. Kelly; Vali, Hojatollah

    Unambiguous detection of extraterrestrial nitrogenous hydrocarbon microbiology requires an instrument both to recognize potential biogenic specimens and to successfully discriminate them from geochemical settings. Such detection should ideally be in-situ and not jeopardize other experiments by altering samples. Taken individually most biomarkers are inconclusive. For example, since amino acids can be synthesized abiotically they are not always considered reliable biomarkers. An enantiomeric imbalance, which is characteristic of all terrestrial life, may be questioned because chirality can also be altered abiotically. However, current scientific understanding holds that aggregates of identical proteins or proteinaceous complexes, with their well-defined amino acid residue sequences, are indisputable biomarkers. Our paper describes the Mars Analytical Microimager, an instrument for the simultaneous imaging of generic autofluorescent biomarkers and overall morphology. Autofluorescence from ultraviolet to near-infrared is emitted by all known terrestrial biology, and often as consistent complex bands uncharacteristic of abiotic mineral luminescence. The MAM acquires morphology, and even sub-micron morphogenesis, at a 3-centimeter working distance with resolution approaching a laser scanning microscope. Luminescence is simultaneously collected via a 2.5-micron aperture, thereby permitting accurate correlation of multi-dimensional optical behavior with specimen morphology. A variable wavelength excitation source and photospectrometer serve to obtain steady-state and excitation spectra of biotic and luminescent abiotic sources. We believe this is the first time instrumentation for detecting hydrated or desiccated microbiology non-destructively in-situ has been demonstrated. We have obtained excellent preliminary detection of biota and inorganic matrix discrimination from terrestrial polar analogues, and perimetric morphology of individual magnetotactic bacteria. Proposed

  17. Application and assessment of multiscale bending energy for morphometric characterization of neural cells

    Cesar, Roberto Marcondes; Costa, Luciano da Fontoura

    1997-05-01

    The estimation of the curvature of experimentally obtained curves is an important issue in many applications of image analysis including biophysics, biology, particle physics, and high energy physics. However, the accurate calculation of the curvature of digital contours has proven to be a difficult endeavor, mainly because of the noise and distortions that are always present in sampled signals. Errors ranging from 1% to 1000% have been reported with respect to the application of standard techniques in the estimation of the curvature of circular contours [M. Worring and A. W. M. Smeulders, CVGIP: Im. Understanding, 58, 366 (1993)]. This article explains how diagrams of multiscale bending energy can be easily obtained from curvegrams and used as a robust general feature for morphometric characterization of neural cells. The bending energy is an interesting global feature for shape characterization that expresses the amount of energy needed to transform the specific shape under analysis into its lowest energy state (i.e., a circle). The curvegram, which can be accurately obtained by using digital signal processing techniques (more specifically through the Fourier transform and its inverse, as described in this work), provides multiscale representation of the curvature of digital contours. The estimation of the bending energy from the curvegram is introduced and exemplified with respect to a series of neural cells. The masked high curvature effect is reported and its implications to shape analysis are discussed. It is also discussed and illustrated that, by normalizing the multiscale bending energy with respect to a standard circle of unitary perimeter, this feature becomes an effective means for expressing shape complexity in a way that is invariant to rotation, translation, and scaling, and that is robust to noise and other artifacts implied by image acquisition.

  18. Wavelet-based multiscale adjoint waveform-difference tomography using body and surface waves

    Yuan, Y. O.; Simons, F. J.; Bozdag, E.

    2014-12-01

    We present a multi-scale scheme for full elastic waveform-difference inversion. Using a wavelet transform proves to be a key factor to mitigate cycle-skipping effects. We start with coarse representations of the seismogram to correct a large-scale background model, and subsequently explain the residuals in the fine scales of the seismogram to map the heterogeneities with great complexity. We have previously applied the multi-scale approach successfully to body waves generated in a standard model from the exploration industry: a modified two-dimensional elastic Marmousi model. With this model we explored the optimal choice of wavelet family, number of vanishing moments and decomposition depth. For this presentation we explore the sensitivity of surface waves in waveform-difference tomography. The incorporation of surface waves is rife with cycle-skipping problems compared to the inversions considering body waves only. We implemented an envelope-based objective function probed via a multi-scale wavelet analysis to measure the distance between predicted and target surface-wave waveforms in a synthetic model of heterogeneous near-surface structure. Our proposed method successfully purges the local minima present in the waveform-difference misfit surface. An elastic shallow model with 100~m in depth is used to test the surface-wave inversion scheme. We also analyzed the sensitivities of surface waves and body waves in full waveform inversions, as well as the effects of incorrect density information on elastic parameter inversions. Based on those numerical experiments, we ultimately formalized a flexible scheme to consider both body and surface waves in adjoint tomography. While our early examples are constructed from exploration-style settings, our procedure will be very valuable for the study of global network data.

  19. Mars Sample Return: Mars Ascent Vehicle Mission and Technology Requirements

    Bowles, Jeffrey V.; Huynh, Loc C.; Hawke, Veronica M.; Jiang, Xun J.

    2013-01-01

    A Mars Sample Return mission is the highest priority science mission for the next decade recommended by the recent Decadal Survey of Planetary Science, the key community input process that guides NASAs science missions. A feasibility study was conducted of a potentially simple and low cost approach to Mars Sample Return mission enabled by the use of developing commercial capabilities. Previous studies of MSR have shown that landing an all up sample return mission with a high mass capacity lander is a cost effective approach. The approach proposed is the use of an emerging commercially available capsule to land the launch vehicle system that would return samples to Earth. This paper describes the mission and technology requirements impact on the launch vehicle system design, referred to as the Mars Ascent Vehicle (MAV).

  20. Nitrogen on Mars: Insights from Curiosity

    Stern, J. C.; Sutter, B.; Jackson, W. A.; Navarro-Gonzalez, Rafael; McKay, Chrisopher P.; Ming, W.; Archer, P. Douglas; Glavin, D. P.; Fairen, A. G.; Mahaffy, Paul R.

    2017-01-01

    Recent detection of nitrate on Mars indicates that nitrogen fixation processes occurred in early martian history. Data collected by the Sample Analysis at Mars (SAM) instrument on the Curiosity Rover can be integrated with Mars analog work in order to better understand the fixation and mobility of nitrogen on Mars, and thus its availability to putative biology. In particular, the relationship between nitrate and other soluble salts may help reveal the timing of nitrogen fixation and post-depositional behavior of nitrate on Mars. In addition, in situ measurements of nitrogen abundance and isotopic composition may be used to model atmospheric conditions on early Mars.

  1. Guidelines for the 2011 MARS exercise

    HR Department

    2011-01-01

    Full details of the Merit Appraisal and Recognition Scheme (MARS) are available via the HR Department’s homepage or directly on the Department’s MARS web page: https://admin-eguide.web.cern.ch/admin-eguide/mars/mars.asp You will find on these pages: MARS procedures, including the MARS timetable for proposals and decisions; regulations with links to the scheme’s statutory basis; a list of frequently asked questions; useful documents with links to relevant documentation, e.g. mandate of the Senior Staff Advisory Committee (SSAC); and related links and contacts. Tel. 70674 / 72728  

  2. Mars Orbiter Camera Views the 'Face on Mars' - Comparison with Viking

    1998-01-01

    Shortly after midnight Sunday morning (5 April 1998 12:39 AM PST), the Mars Orbiter Camera (MOC) on the Mars Global Surveyor (MGS) spacecraft successfully acquired a high resolution image of the 'Face on Mars' feature in the Cydonia region. The image was transmitted to Earth on Sunday, and retrieved from the mission computer data base Monday morning (6 April 1998). The image was processed at the Malin Space Science Systems (MSSS) facility 9:15 AM and the raw image immediately transferred to the Jet Propulsion Laboratory (JPL) for release to the Internet. The images shown here were subsequently processed at MSSS.The picture was acquired 375 seconds after the spacecraft's 220th close approach to Mars. At that time, the 'Face', located at approximately 40.8o N, 9.6o W, was 275 miles (444 km) from the spacecraft. The 'morning' sun was 25o above the horizon. The picture has a resolution of 14.1 feet (4.3 meters) per pixel, making it ten times higher resolution than the best previous image of the feature, which was taken by the Viking Mission in the mid-1970's. The full image covers an area 2.7 miles (4.4 km) wide and 25.7 miles (41.5 km) long.In this comparison, the best Viking image has been enlarged to 3.3 times its original resolution, and the MOC image has been decreased by a similar 3.3 times, creating images of roughly the same size. In addition, the MOC images have been geometrically transformed to a more overhead projection (different from the mercator map projection of PIA01440 & 1441) for ease of comparison with the Viking image. The left image is a portion of Viking Orbiter 1 frame 070A13, the middle image is a portion of MOC frame shown normally, and the right image is the same MOC frame but with the brightness inverted to simulate the approximate lighting conditions of the Viking image.Processing Image processing has been applied to the images in order to improve the visibility of features. This processing included the following steps: The image was

  3. Europe is going to Mars

    1999-06-01

    The Agency's Science Programme Committee (SPC) approved Mars Express after ESA's Council, meeting at ministerial level in Brussels on 11 and 12 May, had agreed the level of the science budget for the next 4 years, just enough to make the mission affordable. "Mars Express is a mission of opportunity and we felt we just had to jump in and do it. We are convinced it will produce first-rate science", says Hans Balsiger, SPC chairman. As well as being a first for Europe in Mars exploration, Mars Express will pioneer new, cheaper ways of doing space science missions. "With a total cost of just 150 million euros, Mars Express will be the cheapest Mars mission ever undertaken", says Roger Bonnet, ESA's Director of Science. Mars Express will be launched in June 2003. When it arrives at the red planet six months later, it will begin to search for water and life. Seven instruments, provided by space research institutes throughout Europe, will make observations from the main spacecraft as it orbits the planet. Just before the spacecraft arrives, it will release a small lander, provided by research institutes in the UK, that will journey on to the surface to look for signs of life. The lander is called Beagle 2 after the ship in which Charles Darwin sailed round the world in search of evidence supporting his theory of evolution. But just as Darwin had to raise the money for his trip, so the search is on for public and private finance for Beagle 2. "Beagle 2 is an extremely important element of the mission", says Bonnet. Europe's space scientists have envisaged a mission to Mars for over fifteen years. But limited funding has prevented previous proposals from going ahead. The positioning of the planets in 2003, however, offers a particularly favourable passage to the red planet - an opportunity not to be missed. Mars Express will be joined by an international flotilla of spacecraft that will also be using this opportunity to work together on scientific questions and pave the way

  4. MARS Validation Plan and Status

    Ahn, Seung-hoon; Cho, Yong-jin

    2008-01-01

    The KINS Reactor Thermal-hydraulic Analysis System (KINS-RETAS) under development is directed toward a realistic analysis approach of best-estimate (BE) codes and realistic assumptions. In this system, MARS is pivoted to provide the BE Thermal-Hydraulic (T-H) response in core and reactor coolant system to various operational transients and accidental conditions. As required for other BE codes, the qualification is essential to ensure reliable and reasonable accuracy for a targeted MARS application. Validation is a key element of the code qualification, and determines the capability of a computer code in predicting the major phenomena expected to occur. The MARS validation was made by its developer KAERI, on basic premise that its backbone code RELAP5/MOD3.2 is well qualified against analytical solutions, test or operational data. A screening was made to select the test data for MARS validation; some models transplanted from RELAP5, if already validated and found to be acceptable, were screened out from assessment. It seems to be reasonable, but does not demonstrate whether code adequacy complies with the software QA guidelines. Especially there may be much difficulty in validating the life-cycle products such as code updates or modifications. This paper presents the plan for MARS validation, and the current implementation status

  5. Space radiation protection: Destination Mars.

    Durante, Marco

    2014-04-01

    National space agencies are planning a human mission to Mars in the XXI century. Space radiation is generally acknowledged as a potential showstopper for this mission for two reasons: a) high uncertainty on the risk of radiation-induced morbidity, and b) lack of simple countermeasures to reduce the exposure. The need for radiation exposure mitigation tools in a mission to Mars is supported by the recent measurements of the radiation field on the Mars Science Laboratory. Shielding is the simplest physical countermeasure, but the current materials provide poor reduction of the dose deposited by high-energy cosmic rays. Accelerator-based tests of new materials can be used to assess additional protection in the spacecraft. Active shielding is very promising, but as yet not applicable in practical cases. Several studies are developing technologies based on superconducting magnetic fields in space. Reducing the transit time to Mars is arguably the best solution but novel nuclear thermal-electric propulsion systems also seem to be far from practical realization. It is likely that the first mission to Mars will employ a combination of these options to reduce radiation exposure. Copyright © 2014 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

  6. Hints of Habitable Environments on Mars Challenge Our Studies of Mars-Analog Sites on Earth

    desMarais, David J

    2009-01-01

    Life as we know it requires water with a chemical activity (alpha) >or approx.0.6 and sources of nutrients and useful energy. Some biota can survive even if favorable conditions occur only intermittently, but the minimum required frequency of occurrences is poorly understood. Recent discoveries have vindicated the Mars exploration strategy to follow the water. Mars Global Surveyor s Thermal Emission Spectrometer (TES) found coarse-grained hematite at Meridiani Planum. Opportunity rover confirmed this and also found evidence of ancient sulfate-rich playa lakes and near-surface groundwater. Elsewhere, TES found evidence of evaporitic halides in topographic depressions. But alpha might not have approached 0.6 in these evaporitic sulfate- and halide-bearing waters. Mars Express (MEX) and Mars Reconnaissance Orbiter (MRO) found extensive sulfate evaporites in Meridiani and Valles Marineris. MEX found phyllosilicates at several sites, most notably Mawrth Valles and Nili Fossae. MRO's CRISM near-IR mapper extended the known diversity and geographic distribution of phyllosilicates to include numerous Noachian craters. Phyllosilicates typically occur at the base of exposed ancient rock sections or in sediments in early Hesperian craters. It is uncertain whether the phyllosilicates developed in surface or subsurface aqueous environments and how long aqueous conditions persisted. Spirit rover found remarkably pure ferric sulfate, indicating oxidation and transport of Fe and S, perhaps in fumaroles or hot springs. Spirit also found opaline silica, consistent with hydrothermal activity. CRISM mapped extensive silica deposits in the Valles Marineris region, consistent with aqueous weathering and deposition. CRISM also found ultramafic rocks and magnesite at Nili Fossae, consistent with serpentinization, a process that can sustain habitable environments on Earth. The report of atmospheric methane implies subsurface aqueous conditions. A working hypothesis is that aqueous

  7. Why send humans to Mars?

    Sagan, Carl

    1991-01-01

    The proposed Space Exploration Initiative (SDI) to launch a manned flight to Mars is examined in the current light of growing constraints in costs and other human requirements. Sharing the huge costs of such a program among a group of nations might become low enough for the project to be feasible. Robotic missions, equipped with enhanced artificial intelligence, appear to be capable of satisfying mission requirements at 10 percent or less, of the cost of a manned flight. Various additional pros and cons are discussed regarding both SDI generally and a Mars mission. It is suggested that R&D projects be pursued that can be better justified and can also contribute to human mission to Mars if eventually a decision to go is made.

  8. Cultivando el mar

    Ricardo Radulovich

    2006-01-01

    Full Text Available Las conocidas y crecientes limitaciones a la agricultura, pesca y disponibilidad de agua para riego tienen pocas soluciones viables y muy probablemente se acrecentarán con el cambio climático. Para contrarrestar estos y otros problemas, estamos desarrollando con y para pobladores costeros empobrecidos, unos sistemas productivos flotantes altamente innovativos, a mar abierto, en aguas protegidas de alto oleaje -comenzando en el Golfo de Nicoya, Costa Rica, que es un sitio representativo que cubre miles de km2-. Estos sistemas de propósito múltiple, y de multi-estratos, que hemos probado por 3 años y que describimos aquí, consisten de: hortalizas orgánicas u otros cultivos de alto valor, en macetas sobre isletas o jardineras flotantes, construidas con botellas plásticas recicladas y otros materiales de bajo costo; maricultura de poco insumo bajo el agua (peces, crustáceos, otros con cultivo de algas flotando en la superficie; producción de agua dulce para riego y otros usos por destilación solar pasiva y cosecha de agua de lluvia; pesca desde las estructuras flotantes; facilidades para recreación; y, todavía por explorar, producción alternativa de energía. Se considera aquí también una variedad de aspectos relacionados con el ambiente y la biodiversidad. Estos sistemas compuestos, únicos en el mundo a la fecha, tienen una productividad general alta al sumar la productividad de todo el año de cada uno de varios componentes eco-amigables y de bajo insumo, lo cual permite optimizar la rentabilidad en función ambiental. Esperamos que, una vez que estén validados, la implementación equitativa a escala de estos nuevos sistemas proveerá a los pobladores costeros, alrededor del mundo tropical y subtropical, oportunidades para derivar su ingreso a partir de esta generación de nueva riqueza, incrementándose así y ganando en seguridad la capacidad mundial de producción de alimentos y agua, practicándose a la vez un uso de los

  9. Expanded Mixed Multiscale Finite Element Methods and Their Applications for Flows in Porous Media

    Jiang, L.; Copeland, D.; Moulton, J. D.

    2012-01-01

    We develop a family of expanded mixed multiscale finite element methods (MsFEMs) and their hybridizations for second-order elliptic equations. This formulation expands the standard mixed multiscale finite element formulation in the sense that four

  10. The dynamics in the upper atmospheres of Mars and Titan

    Bell, Jared M.

    2008-06-01

    This thesis explores the dynamics of two terrestrial bodies: Mars and Titan. At Mars, the coupled Mars General Circulation Model - Mars Thermospheric General Circulation Model (MGCM-MTGCM) is employed to investigate the phenomenon known as Mars winter polar warming. At Titan, a new theoretical model, the Titan Global Ionosphere - Thermosphere Model (T-GITM), is developed, based upon previous work by Ridley et al. [2006]. Using this new model, three separate numerical studies quantify the impacts of solar cycle, seasons, and lower boundary zonal winds on the Titan thermosphere structure and dynamics. At Mars, this thesis investigates thermospheric winter polar warming through three major studies: (1) a systematic analysis of vertical dust mixing in the lower atmosphere and its impact upon the dynamics of the lower thermosphere (100-130 km), (2) an interannual investigation utilizing three years of lower atmosphere infrared (IR) dust optical depth data acquired by the Thermal Emission Spectrometer (TES) instrument on board Mars Global Surveyor (MGS), and finally (3) a brief study of the MTGCM's response to variations in upward propagating waves and tides from the lower atmosphere. Ultimately, this investigation suggests that an interhemispheric summer-to-winter Hadley circulation, originating in the lower atmosphere and extending into the upper atmosphere, is responsible for thermospheric winter polar warming [ Bell etal. , 2007]. A major branch of this thesis builds upon the previous work of Müller-Wodarg et al. [2000], Müller-Wodarg et al. [2003], M7uuml;ller-Wodarg et al. [2006], and Yelle et al. [2006] as it attempts to explain the structures in Titan's upper atmosphere, between 500-1500 km. Building also upon the recent development of GITM by Ridley et al. [2006], this thesis presents a new theoretical framework, T-GITM. This model is then employed to conduct a series of numerical experiments to quantify the impacts of the solar cycle, the season, and the

  11. Officine Galileo for Mars Exploration

    Battistelli, E.; Tacconi, M.

    1999-09-01

    The interest for Mars's exploration is continuously increasing. Officine Galileo is engaged in this endeavor with several programmes. The exobiology is, of course, a stimulating field; presently Officine Galileo is leading a team with Dasa and Tecnospazio, under ESA contract, for the definition of a facility for the search of extinct life on Mars through the detection of indicators of life. The system, to be embarked on a Mars lander, is based on a drill to take rock samples underneath the oxidised soil layer, on a sample preparation and distribution system devoted to condition and bring the sample to a set of analytical instruments to carry out in-situ chemical and mineralogical investigations. The facility benefits of the presence of optical microscope, gas chromatograph, several spectrometers (Raman, Mass, Mossbauer, APX-Ray), and further instruments. In the frame of planetology, Officine Galileo is collaborating with several Principal Investigators to the definition of a set of instruments to be integrated on the Mars 2003 Lander (a NASA-ASI cooperation). A drill (by Tecnospazio), with the main task to collect Mars soil samples for the subsequent storage and return to Earth, will have the capability to perform several soil analyses, e.g. temperature and near infrared reflectivity spectra down to 50 cm depth, surface thermal and electrical conductivity, sounding of electromagnetic properties down to a few hundreds meter, radioactivity. Moreover a kit of instruments for in-situ soil samples analyses if foreseen; it is based on a dust analyser, an IR spectrometer, a thermofluorescence sensor, and a radioactivity analyser. The attention to the Red Planet is growing, in parallel with the findings of present and planned missions. In the following years the technology of Officine Galileo will carry a strong contribution to the science of Mars.

  12. Wave phenomena comparison between Mars and Titan upper atmospheres

    Elrod, Meredith K.; Bell, J. M.

    2013-10-01

    We will examine the presence of waves in the neutral atmospheres of two terrestrial bodies: Mars and Titan. We will examine the aerobraking datasets from both the Mars Global Surveyor (MGS) and Mars Odyssey (ODY) missions, analyzing the neutral densities to characterize the planetary tides and/or smaller-scale internal gravity waves present in the data. While several studies have examined these features before at Mars (e.g., Forbes et al. [2002] and Fritts and Tolson [2006]), we will be focusing on examining whether or not the wave features observed in the thermosphere could be explained primarily with planetary tides, as posted recently in Klienbohl et al. [2013]. In addition to this, we will also examine the neutral densities obtained by the Cassini Ion-Neutral Mass Spectrometer (INMS) in order to determine if planetary tides can explain the numerous wave-like features that have been interpreted as gravity waves propagating vertically (cf., Mueller-Wodarg et al. [2008], Cui et al. [2013], and Snowden et al. [2013]).

  13. Advanced Mars Water Acquisition System, Phase I

    National Aeronautics and Space Administration — The Advanced Mars Water Acquisition System (AMWAS) recovers and purifies water from Mars soils for oxygen and fuel production, life support, food production, and...

  14. Mars Aqueous Processing System, Phase II

    National Aeronautics and Space Administration — The Mars Aqueous Processing System (MAPS) is a novel technology for recovering oxygen, iron, and other constituents from lunar and Mars soils. The closed-loop...

  15. Mirror Advanced Reactor Study (MARS)

    Logan, B.G.

    1983-01-01

    Progress in a two year study of a 1200 MWe commercial tandem mirror reactor (MARS - Mirror Advanced Reactor Study) has reached the point where major reactor system technologies are identified. New design features of the magnets, blankets, plug heating systems and direct converter are described. With the innovation of radial drift pumping to maintain low plug density, reactor recirculating power fraction is reduced to 20%. Dominance of radial ion and impurity losses into the halo permits gridless, circular direct converters to be dramatically reduced in size. Comparisons of MARS with the Starfire tokamak design are made

  16. Multi-scale approximation of Vlasov equation

    Mouton, A.

    2009-09-01

    One of the most important difficulties of numerical simulation of magnetized plasmas is the existence of multiple time and space scales, which can be very different. In order to produce good simulations of these multi-scale phenomena, it is recommended to develop some models and numerical methods which are adapted to these problems. Nowadays, the two-scale convergence theory introduced by G. Nguetseng and G. Allaire is one of the tools which can be used to rigorously derive multi-scale limits and to obtain new limit models which can be discretized with a usual numerical method: this procedure is so-called a two-scale numerical method. The purpose of this thesis is to develop a two-scale semi-Lagrangian method and to apply it on a gyrokinetic Vlasov-like model in order to simulate a plasma submitted to a large external magnetic field. However, the physical phenomena we have to simulate are quite complex and there are many questions without answers about the behaviour of a two-scale numerical method, especially when such a method is applied on a nonlinear model. In a first part, we develop a two-scale finite volume method and we apply it on the weakly compressible 1D isentropic Euler equations. Even if this mathematical context is far from a Vlasov-like model, it is a relatively simple framework in order to study the behaviour of a two-scale numerical method in front of a nonlinear model. In a second part, we develop a two-scale semi-Lagrangian method for the two-scale model developed by E. Frenod, F. Salvarani et E. Sonnendrucker in order to simulate axisymmetric charged particle beams. Even if the studied physical phenomena are quite different from magnetic fusion experiments, the mathematical context of the one-dimensional paraxial Vlasov-Poisson model is very simple for establishing the basis of a two-scale semi-Lagrangian method. In a third part, we use the two-scale convergence theory in order to improve M. Bostan's weak-* convergence results about the finite

  17. Multiscale Modeling of Mesoscale and Interfacial Phenomena

    Petsev, Nikolai Dimitrov

    we provide a novel and general framework for multiscale modeling of systems featuring one or more dissolved species. This makes it possible to retain molecular detail for parts of the problem that require it while using a simple, continuum description for parts where high detail is unnecessary, reducing the number of degrees of freedom (i.e. number of particles) dramatically. This opens the possibility for modeling ion transport in biological processes and biomolecule assembly in ionic solution, as well as electrokinetic phenomena at interfaces such as corrosion. The number of particles in the system is further reduced through an integrated boundary approach, which we apply to colloidal suspensions. In this thesis, we describe this general framework for multiscale modeling single- and multicomponent systems, provide several simple equilibrium and non-equilibrium case studies, and discuss future applications.

  18. A multi-scale network method for two-phase flow in porous media

    Khayrat, Karim, E-mail: khayratk@ifd.mavt.ethz.ch; Jenny, Patrick

    2017-08-01

    Pore-network models of porous media are useful in the study of pore-scale flow in porous media. In order to extract macroscopic properties from flow simulations in pore-networks, it is crucial the networks are large enough to be considered representative elementary volumes. However, existing two-phase network flow solvers are limited to relatively small domains. For this purpose, a multi-scale pore-network (MSPN) method, which takes into account flow-rate effects and can simulate larger domains compared to existing methods, was developed. In our solution algorithm, a large pore network is partitioned into several smaller sub-networks. The algorithm to advance the fluid interfaces within each subnetwork consists of three steps. First, a global pressure problem on the network is solved approximately using the multiscale finite volume (MSFV) method. Next, the fluxes across the subnetworks are computed. Lastly, using fluxes as boundary conditions, a dynamic two-phase flow solver is used to advance the solution in time. Simulation results of drainage scenarios at different capillary numbers and unfavourable viscosity ratios are presented and used to validate the MSPN method against solutions obtained by an existing dynamic network flow solver.

  19. Simulating multi-scale oceanic processes around Taiwan on unstructured grids

    Yu, Hao-Cheng; Zhang, Yinglong J.; Yu, Jason C. S.; Terng, C.; Sun, Weiling; Ye, Fei; Wang, Harry V.; Wang, Zhengui; Huang, Hai

    2017-11-01

    We validate a 3D unstructured-grid (UG) model for simulating multi-scale processes as occurred in Northwestern Pacific around Taiwan using recently developed new techniques (Zhang et al., Ocean Modeling, 102, 64-81, 2016) that require no bathymetry smoothing even for this region with prevalent steep bottom slopes and many islands. The focus is on short-term forecast for several months instead of long-term variability. Compared with satellite products, the errors for the simulated Sea-surface Height (SSH) and Sea-surface Temperature (SST) are similar to a reference data-assimilated global model. In the nearshore region, comparison with 34 tide gauges located around Taiwan indicates an average RMSE of 13 cm for the tidal elevation. The average RMSE for SST at 6 coastal buoys is 1.2 °C. The mean transport and eddy kinetic energy compare reasonably with previously published values and the reference model used to provide boundary and initial conditions. The model suggests ∼2-day interruption of Kuroshio east of Taiwan during a typhoon period. The effect of tidal mixing is shown to be significant nearshore. The multi-scale model is easily extendable to target regions of interest due to its UG framework and a flexible vertical gridding system, which is shown to be superior to terrain-following coordinates.

  20. A multi-scale network method for two-phase flow in porous media

    Khayrat, Karim; Jenny, Patrick

    2017-01-01

    Pore-network models of porous media are useful in the study of pore-scale flow in porous media. In order to extract macroscopic properties from flow simulations in pore-networks, it is crucial the networks are large enough to be considered representative elementary volumes. However, existing two-phase network flow solvers are limited to relatively small domains. For this purpose, a multi-scale pore-network (MSPN) method, which takes into account flow-rate effects and can simulate larger domains compared to existing methods, was developed. In our solution algorithm, a large pore network is partitioned into several smaller sub-networks. The algorithm to advance the fluid interfaces within each subnetwork consists of three steps. First, a global pressure problem on the network is solved approximately using the multiscale finite volume (MSFV) method. Next, the fluxes across the subnetworks are computed. Lastly, using fluxes as boundary conditions, a dynamic two-phase flow solver is used to advance the solution in time. Simulation results of drainage scenarios at different capillary numbers and unfavourable viscosity ratios are presented and used to validate the MSPN method against solutions obtained by an existing dynamic network flow solver.

  1. Structural health monitoring using DOG multi-scale space: an approach for analyzing damage characteristics

    Guo, Tian; Xu, Zili

    2018-03-01

    Measurement noise is inevitable in practice; thus, it is difficult to identify defects, cracks or damage in a structure while suppressing noise simultaneously. In this work, a novel method is introduced to detect multiple damage in noisy environments. Based on multi-scale space analysis for discrete signals, a method for extracting damage characteristics from the measured displacement mode shape is illustrated. Moreover, the proposed method incorporates a data fusion algorithm to further eliminate measurement noise-based interference. The effectiveness of the method is verified by numerical and experimental methods applied to different structural types. The results demonstrate that there are two advantages to the proposed method. First, damage features are extracted by the difference of the multi-scale representation; this step is taken such that the interference of noise amplification can be avoided. Second, a data fusion technique applied to the proposed method provides a global decision, which retains the damage features while maximally eliminating the uncertainty. Monte Carlo simulations are utilized to validate that the proposed method has a higher accuracy in damage detection.

  2. An improved gravity model for Mars: Goddard Mars Model 1

    Smith, D. E.; Lerch, F. J.; Nerem, R. S.; Zuber, M. T.; Patel, G. B.; Fricke, S. K.; Lemoine, F. G.

    1993-01-01

    Doppler tracking data of three orbiting spacecraft have been reanalyzed to develop a new gravitational field model for the planet Mars, Goddard Mars Model 1 (GMM-1). This model employs nearly all available data, consisting of approximately 1100 days of S band tracking data collected by NASA's Deep Space Network from the Mariner 9 and Viking 1 and Viking 2 spacecraft, in seven different orbits, between 1971 and 1979. GMM-1 is complete to spherical harmonic degree and order 50, which corresponds to a half-wavelength spatial resolution of 200-300 km where the data permit. GMM-1 represents satellite orbits with considerably better accuracy than previous Mars gravity models and shows greater resolution of identifiable geological structures. The notable improvement in GMM-1 over previous models is a consequence of several factors: improved computational capabilities, the use of otpimum weighting and least squares collocation solution techniques which stabilized the behavior of the solution at high degree and order, and the use of longer satellite arcs than employed in previous solutions that were made possible by improved force and measurement models. The inclusion of X band tracking data from the 379-km altitude, nnear-polar orbiting Mars Observer spacecraft should provide a significant improvement over GMM-1, particularly at high latitudes where current data poorly resolve the gravitational signature of the planet.

  3. Numerical analysis of APR1400 Steam Generator by CUPID/MARS heat structure coupling

    Lee, Jae Ryong Lee; Lee, Seung Jun; Pakr, Ik Kyu; Yoon, Han Young [KAERI, Daejeon (Korea, Republic of); Cho, Hyoung Kyu [Seoul National University, Seoul (Korea, Republic of)

    2015-05-15

    To design and analyze steam generators, many computer codes have been developed and used around the world. In this study, the coupled CUPID and MARS code was used for the simulation of boiler side of the PWR steam generator. This paper presents the description of the coupling method, validation for porous media approach against the rod bundle experiment and the preliminary simulation results of PWR steam generator using the coupled code. In the present study, the multi-scale thermal-hydraulic analysis method using the coupled CUPID/MARS code was applied for the simulation of the steam generator. The primary side of the steam generator and other RCS was simulated by MARS and the secondary side was calculated by CUPID with porous media approach. For coupled simulation, the porous medium was applied in order to take into account the effect of the U-tube bundle and other supporting structure which play a role to be a flow resistance. More realistic physical model such as moisture separator slug behavior should be developed for the near future. The application of the coupled simulation should be extended to the accident scenario.

  4. Multiscale virtual particle based elastic network model (MVP-ENM) for normal mode analysis of large-sized biomolecules.

    Xia, Kelin

    2017-12-20

    In this paper, a multiscale virtual particle based elastic network model (MVP-ENM) is proposed for the normal mode analysis of large-sized biomolecules. The multiscale virtual particle (MVP) model is proposed for the discretization of biomolecular density data. With this model, large-sized biomolecular structures can be coarse-grained into virtual particles such that a balance between model accuracy and computational cost can be achieved. An elastic network is constructed by assuming "connections" between virtual particles. The connection is described by a special harmonic potential function, which considers the influence from both the mass distributions and distance relations of the virtual particles. Two independent models, i.e., the multiscale virtual particle based Gaussian network model (MVP-GNM) and the multiscale virtual particle based anisotropic network model (MVP-ANM), are proposed. It has been found that in the Debye-Waller factor (B-factor) prediction, the results from our MVP-GNM with a high resolution are as good as the ones from GNM. Even with low resolutions, our MVP-GNM can still capture the global behavior of the B-factor very well with mismatches predominantly from the regions with large B-factor values. Further, it has been demonstrated that the low-frequency eigenmodes from our MVP-ANM are highly consistent with the ones from ANM even with very low resolutions and a coarse grid. Finally, the great advantage of MVP-ANM model for large-sized biomolecules has been demonstrated by using two poliovirus virus structures. The paper ends with a conclusion.

  5. Astrobiology through the ages of Mars: the study of terrestrial analogues to understand the habitability of Mars.

    Fairén, Alberto G; Davila, Alfonso F; Lim, Darlene; Bramall, Nathan; Bonaccorsi, Rosalba; Zavaleta, Jhony; Uceda, Esther R; Stoker, Carol; Wierzchos, Jacek; Dohm, James M; Amils, Ricardo; Andersen, Dale; McKay, Christopher P

    2010-10-01

    Mars has undergone three main climatic stages throughout its geological history, beginning with a water-rich epoch, followed by a cold and semi-arid era, and transitioning into present-day arid and very cold desert conditions. These global climatic eras also represent three different stages of planetary habitability: an early, potentially habitable stage when the basic requisites for life as we know it were present (liquid water and energy); an intermediate extreme stage, when liquid solutions became scarce or very challenging for life; and the most recent stage during which conditions on the surface have been largely uninhabitable, except perhaps in some isolated niches. Our understanding of the evolution of Mars is now sufficient to assign specific terrestrial environments to each of these periods. Through the study of Mars terrestrial analogues, we have assessed and constrained the habitability conditions for each of these stages, the geochemistry of the surface, and the likelihood for the preservation of organic and inorganic biosignatures. The study of these analog environments provides important information to better understand past and current mission results as well as to support the design and selection of instruments and the planning for future exploratory missions to Mars.

  6. Multiscale Mathematics for Biomass Conversion to Renewable Hydrogen

    Plechac, Petr [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Mathematics; Univ. of Delaware, Newark, DE (United States). Dept. of Mathematics; Vlachos, Dionisios [Univ. of Delaware, Newark, DE (United States). Dept. of Chemical and Biomolecular Engineering; Katsoulakis, Markos [Univ. of Massachusetts, Amherst, MA (United States). Dept. of Mathematics

    2013-09-05

    The overall objective of this project is to develop multiscale models for understanding and eventually designing complex processes for renewables. To the best of our knowledge, our work is the first attempt at modeling complex reacting systems, whose performance relies on underlying multiscale mathematics. Our specific application lies at the heart of biofuels initiatives of DOE and entails modeling of catalytic systems, to enable economic, environmentally benign, and efficient conversion of biomass into either hydrogen or valuable chemicals. Specific goals include: (i) Development of rigorous spatio-temporal coarse-grained kinetic Monte Carlo (KMC) mathematics and simulation for microscopic processes encountered in biomass transformation. (ii) Development of hybrid multiscale simulation that links stochastic simulation to a deterministic partial differential equation (PDE) model for an entire reactor. (iii) Development of hybrid multiscale simulation that links KMC simulation with quantum density functional theory (DFT) calculations. (iv) Development of parallelization of models of (i)-(iii) to take advantage of Petaflop computing and enable real world applications of complex, multiscale models. In this NCE period, we continued addressing these objectives and completed the proposed work. Main initiatives, key results, and activities are outlined.

  7. The Goddard multi-scale modeling system with unified physics

    W.-K. Tao

    2009-08-01

    Full Text Available Recently, a multi-scale modeling system with unified physics was developed at NASA Goddard. It consists of (1 a cloud-resolving model (CRM, (2 a regional-scale model, the NASA unified Weather Research and Forecasting Model (WRF, and (3 a coupled CRM-GCM (general circulation model, known as the Goddard Multi-scale Modeling Framework or MMF. The same cloud-microphysical processes, long- and short-wave radiative transfer and land-surface processes are applied in all of the models to study explicit cloud-radiation and cloud-surface interactive processes in this multi-scale modeling system. This modeling system has been coupled with a multi-satellite simulator for comparison and validation with NASA high-resolution satellite data.

    This paper reviews the development and presents some applications of the multi-scale modeling system, including results from using the multi-scale modeling system to study the interactions between clouds, precipitation, and aerosols. In addition, use of the multi-satellite simulator to identify the strengths and weaknesses of the model-simulated precipitation processes will be discussed as well as future model developments and applications.

  8. Multiscale Modeling in the Clinic: Drug Design and Development

    Clancy, Colleen E.; An, Gary; Cannon, William R.; Liu, Yaling; May, Elebeoba E.; Ortoleva, Peter; Popel, Aleksander S.; Sluka, James P.; Su, Jing; Vicini, Paolo; Zhou, Xiaobo; Eckmann, David M.

    2016-02-17

    A wide range of length and time scales are relevant to pharmacology, especially in drug development, drug design and drug delivery. Therefore, multi-scale computational modeling and simulation methods and paradigms that advance the linkage of phenomena occurring at these multiple scales have become increasingly important. Multi-scale approaches present in silico opportunities to advance laboratory research to bedside clinical applications in pharmaceuticals research. This is achievable through the capability of modeling to reveal phenomena occurring across multiple spatial and temporal scales, which are not otherwise readily accessible to experimentation. The resultant models, when validated, are capable of making testable predictions to guide drug design and delivery. In this review we describe the goals, methods, and opportunities of multi-scale modeling in drug design and development. We demonstrate the impact of multiple scales of modeling in this field. We indicate the common mathematical techniques employed for multi-scale modeling approaches used in pharmacology and present several examples illustrating the current state-of-the-art regarding drug development for: Excitable Systems (Heart); Cancer (Metastasis and Differentiation); Cancer (Angiogenesis and Drug Targeting); Metabolic Disorders; and Inflammation and Sepsis. We conclude with a focus on barriers to successful clinical translation of drug development, drug design and drug delivery multi-scale models.

  9. Multiscale image restoration in nulear medicine

    Jammal, G.

    2001-01-01

    This work develops, analyzes and validates a new multiscale restoration framework for denoising and deconvolution in photon limited imagery. Denoising means the estimation of the intensity of a Poisson process from a single observation of the counts, whereas deconvolution refers to the recovery of an object related through a linear system of equations to the intensity function of the Poisson data. The developed framework has been named DeQuant in analogy to Denoising when the noise is of Quantum nature. DeQuant works according to the following scheme. (1) It starts by testing the statistical significance of the wavelet coefficients of the Poisson process, based on the knowledge of their probability density function. (2) A regularization constraint assigns a new value to the non significant coefficients enabling therewith to reduce artifacts and incorporate realistic prior information into the estimation process. Finally, (3) the application of the inverse wavelet transform yields the restored object. The whole procedure is iterated before obtaining the final estimate. The validation of DeQuant on nuclear medicine images showed excellent results. The obtained estimates enable a greater diagnostic confidence in clinical nuclear medicine since they give the physician the access to the diagnosis relevant information with a measure of the significance of the detected structures [de

  10. Multiscale Reconstruction for Magnetic Resonance Fingerprinting

    Pierre, Eric Y.; Ma, Dan; Chen, Yong; Badve, Chaitra; Griswold, Mark A.

    2015-01-01

    Purpose To reduce acquisition time needed to obtain reliable parametric maps with Magnetic Resonance Fingerprinting. Methods An iterative-denoising algorithm is initialized by reconstructing the MRF image series at low image resolution. For subsequent iterations, the method enforces pixel-wise fidelity to the best-matching dictionary template then enforces fidelity to the acquired data at slightly higher spatial resolution. After convergence, parametric maps with desirable spatial resolution are obtained through template matching of the final image series. The proposed method was evaluated on phantom and in-vivo data using the highly-undersampled, variable-density spiral trajectory and compared with the original MRF method. The benefits of additional sparsity constraints were also evaluated. When available, gold standard parameter maps were used to quantify the performance of each method. Results The proposed approach allowed convergence to accurate parametric maps with as few as 300 time points of acquisition, as compared to 1000 in the original MRF work. Simultaneous quantification of T1, T2, proton density (PD) and B0 field variations in the brain was achieved in vivo for a 256×256 matrix for a total acquisition time of 10.2s, representing a 3-fold reduction in acquisition time. Conclusions The proposed iterative multiscale reconstruction reliably increases MRF acquisition speed and accuracy. PMID:26132462

  11. Predicting FLDs Using a Multiscale Modeling Scheme

    Wu, Z.; Loy, C.; Wang, E.; Hegadekatte, V.

    2017-09-01

    The measurement of a single forming limit diagram (FLD) requires significant resources and is time consuming. We have developed a multiscale modeling scheme to predict FLDs using a combination of limited laboratory testing, crystal plasticity (VPSC) modeling, and dual sequential-stage finite element (ABAQUS/Explicit) modeling with the Marciniak-Kuczynski (M-K) criterion to determine the limit strain. We have established a means to work around existing limitations in ABAQUS/Explicit by using an anisotropic yield locus (e.g., BBC2008) in combination with the M-K criterion. We further apply a VPSC model to reduce the number of laboratory tests required to characterize the anisotropic yield locus. In the present work, we show that the predicted FLD is in excellent agreement with the measured FLD for AA5182 in the O temper. Instead of 13 different tests as for a traditional FLD determination within Novelis, our technique uses just four measurements: tensile properties in three orientations; plane strain tension; biaxial bulge; and the sheet crystallographic texture. The turnaround time is consequently far less than for the traditional laboratory measurement of the FLD.

  12. Laser Writing of Multiscale Chiral Polymer Metamaterials

    E. P. Furlani

    2012-01-01

    Full Text Available A new approach to metamaterials is presented that involves laser-based patterning of novel chiral polymer media, wherein chirality is realized at two distinct length scales, intrinsically at the molecular level and geometrically at a length scale on the order of the wavelength of the incident field. In this approach, femtosecond-pulsed laser-induced two-photon lithography (TPL is used to pattern a photoresist-chiral polymer mixture into planar chiral shapes. Enhanced bulk chirality can be realized by tuning the wavelength-dependent chiral response at both the molecular and geometric level to ensure an overlap of their respective spectra. The approach is demonstrated via the fabrication of a metamaterial consisting of a two-dimensional array of chiral polymer-based L-structures. The fabrication process is described and modeling is performed to demonstrate the distinction between molecular and planar geometric-based chirality and the effects of the enhanced multiscale chirality on the optical response of such media. This new approach to metamaterials holds promise for the development of tunable, polymer-based optical metamaterials with low loss.

  13. A multiscale modeling approach for biomolecular systems

    Bowling, Alan, E-mail: bowling@uta.edu; Haghshenas-Jaryani, Mahdi, E-mail: mahdi.haghshenasjaryani@mavs.uta.edu [The University of Texas at Arlington, Department of Mechanical and Aerospace Engineering (United States)

    2015-04-15

    This paper presents a new multiscale molecular dynamic model for investigating the effects of external interactions, such as contact and impact, during stepping and docking of motor proteins and other biomolecular systems. The model retains the mass properties ensuring that the result satisfies Newton’s second law. This idea is presented using a simple particle model to facilitate discussion of the rigid body model; however, the particle model does provide insights into particle dynamics at the nanoscale. The resulting three-dimensional model predicts a significant decrease in the effect of the random forces associated with Brownian motion. This conclusion runs contrary to the widely accepted notion that the motor protein’s movements are primarily the result of thermal effects. This work focuses on the mechanical aspects of protein locomotion; the effect ATP hydrolysis is estimated as internal forces acting on the mechanical model. In addition, the proposed model can be numerically integrated in a reasonable amount of time. Herein, the differences between the motion predicted by the old and new modeling approaches are compared using a simplified model of myosin V.

  14. Multiscale wavelet representations for mammographic feature analysis

    Laine, Andrew F.; Song, Shuwu

    1992-12-01

    This paper introduces a novel approach for accomplishing mammographic feature analysis through multiresolution representations. We show that efficient (nonredundant) representations may be identified from digital mammography and used to enhance specific mammographic features within a continuum of scale space. The multiresolution decomposition of wavelet transforms provides a natural hierarchy in which to embed an interactive paradigm for accomplishing scale space feature analysis. Choosing wavelets (or analyzing functions) that are simultaneously localized in both space and frequency, results in a powerful methodology for image analysis. Multiresolution and orientation selectivity, known biological mechanisms in primate vision, are ingrained in wavelet representations and inspire the techniques presented in this paper. Our approach includes local analysis of complete multiscale representations. Mammograms are reconstructed from wavelet coefficients, enhanced by linear, exponential and constant weight functions localized in scale space. By improving the visualization of breast pathology we can improve the changes of early detection of breast cancers (improve quality) while requiring less time to evaluate mammograms for most patients (lower costs).

  15. Multiscale modeling of polyisoprene on graphite

    Pandey, Yogendra Narayan; Brayton, Alexander; Doxastakis, Manolis; Burkhart, Craig; Papakonstantopoulos, George J.

    2014-01-01

    The local dynamics and the conformational properties of polyisoprene next to a smooth graphite surface constructed by graphene layers are studied by a multiscale methodology. First, fully atomistic molecular dynamics simulations of oligomers next to the surface are performed. Subsequently, Monte Carlo simulations of a systematically derived coarse-grained model generate numerous uncorrelated structures for polymer systems. A new reverse backmapping strategy is presented that reintroduces atomistic detail. Finally, multiple extensive fully atomistic simulations with large systems of long macromolecules are employed to examine local dynamics in proximity to graphite. Polyisoprene repeat units arrange close to a parallel configuration with chains exhibiting a distribution of contact lengths. Efficient Monte Carlo algorithms with the coarse-grain model are capable of sampling these distributions for any molecular weight in quantitative agreement with predictions from atomistic models. Furthermore, molecular dynamics simulations with well-equilibrated systems at all length-scales support an increased dynamic heterogeneity that is emerging from both intermolecular interactions with the flat surface and intramolecular cooperativity. This study provides a detailed comprehensive picture of polyisoprene on a flat surface and consists of an effort to characterize such systems in atomistic detail

  16. Multiscale Modeling of UHTC: Thermal Conductivity

    Lawson, John W.; Murry, Daw; Squire, Thomas; Bauschlicher, Charles W.

    2012-01-01

    We are developing a multiscale framework in computational modeling for the ultra high temperature ceramics (UHTC) ZrB2 and HfB2. These materials are characterized by high melting point, good strength, and reasonable oxidation resistance. They are candidate materials for a number of applications in extreme environments including sharp leading edges of hypersonic aircraft. In particular, we used a combination of ab initio methods, atomistic simulations and continuum computations to obtain insights into fundamental properties of these materials. Ab initio methods were used to compute basic structural, mechanical and thermal properties. From these results, a database was constructed to fit a Tersoff style interatomic potential suitable for atomistic simulations. These potentials were used to evaluate the lattice thermal conductivity of single crystals and the thermal resistance of simple grain boundaries. Finite element method (FEM) computations using atomistic results as inputs were performed with meshes constructed on SEM images thereby modeling the realistic microstructure. These continuum computations showed the reduction in thermal conductivity due to the grain boundary network.

  17. Fast Plasma Investigation for Magnetospheric Multiscale

    Pollock, C.; Moore, T.; Coffey, V.; Dorelli J.; Giles, B.; Adrian, M.; Chandler, M.; Duncan, C.; Figueroa-Vinas, A.; Garcia, K.; hide

    2016-01-01

    The Fast Plasma Investigation (FPI) was developed for flight on the Magnetospheric Multiscale (MMS) mission to measure the differential directional flux of magnetospheric electrons and ions with unprecedented time resolution to resolve kinetic-scale plasma dynamics. This increased resolution has been accomplished by placing four dual 180-degree top hat spectrometers for electrons and four dual 180-degree top hat spectrometers for ions around the periphery of each of four MMS spacecraft. Using electrostatic field-of-view deflection, the eight spectrometers for each species together provide 4pi-sr-field-of-view with, at worst, 11.25-degree sample spacing. Energy/charge sampling is provided by swept electrostatic energy/charge selection over the range from 10 eVq to 30000 eVq. The eight dual spectrometers on each spacecraft are controlled and interrogated by a single block redundant Instrument Data Processing Unit, which in turn interfaces to the observatory's Instrument Suite Central Instrument Data processor. This paper described the design of FPI, its ground and in-flight calibration, its operational concept, and its data products.

  18. Multiscale Concrete Modeling of Aging Degradation

    Hammi, Yousseff [Mississippi State Univ., Mississippi State, MS (United States); Gullett, Philipp [Mississippi State Univ., Mississippi State, MS (United States); Horstemeyer, Mark F. [Mississippi State Univ., Mississippi State, MS (United States)

    2015-07-31

    In this work a numerical finite element framework is implemented to enable the integration of coupled multiscale and multiphysics transport processes. A User Element subroutine (UEL) in Abaqus is used to simultaneously solve stress equilibrium, heat conduction, and multiple diffusion equations for 2D and 3D linear and quadratic elements. Transport processes in concrete structures and their degradation mechanisms are presented along with the discretization of the governing equations. The multiphysics modeling framework is theoretically extended to the linear elastic fracture mechanics (LEFM) by introducing the eXtended Finite Element Method (XFEM) and based on the XFEM user element implementation of Giner et al. [2009]. A damage model that takes into account the damage contribution from the different degradation mechanisms is theoretically developed. The total contribution of damage is forwarded to a Multi-Stage Fatigue (MSF) model to enable the assessment of the fatigue life and the deterioration of reinforced concrete structures in a nuclear power plant. Finally, two examples are presented to illustrate the developed multiphysics user element implementation and the XFEM implementation of Giner et al. [2009].

  19. Magnetospheric MultiScale (MMS) System Manager

    Schiff, Conrad; Maher, Francis Alfred; Henely, Sean Philip; Rand, David

    2014-01-01

    The Magnetospheric MultiScale (MMS) mission is an ambitious NASA space science mission in which 4 spacecraft are flown in tight formation about a highly elliptical orbit. Each spacecraft has multiple instruments that measure particle and field compositions in the Earths magnetosphere. By controlling the members relative motion, MMS can distinguish temporal and spatial fluctuations in a way that a single spacecraft cannot.To achieve this control, 2 sets of four maneuvers, distributed evenly across the spacecraft must be performed approximately every 14 days. Performing a single maneuver on an individual spacecraft is usually labor intensive and the complexity becomes clearly increases with four. As a result, the MMS flight dynamics team turned to the System Manager to put the routine or error-prone under machine control freeing the analysts for activities that require human judgment.The System Manager is an expert system that is capable of handling operations activities associated with performing MMS maneuvers. As an expert system, it can work off a known schedule, launching jobs based on a one-time occurrence or on a set reoccurring schedule. It is also able to detect situational changes and use event-driven programming to change schedules, adapt activities, or call for help.

  20. Mars - The relationship of robotic and human elements in the IAA International Exploration of Mars study

    Marov, Mikhail YA.; Duke, Michael B.

    1993-01-01

    The roles of human and robotic missions in Mars exploration are defined in the context of the short- and long-term Mars programs. In particular, it is noted that the currently implemented and planned missions to Mars can be regarded as robotic precursor missions to human exploration. Attention is given to factors that must be considered in formulating the rationale for human flights to Mars and future human Mars settlements and justifying costly projects.

  1. GPS Navigation for the Magnetospheric Multi-Scale Mission

    Bamford, William; Mitchell, Jason; Southward, Michael; Baldwin, Philip; Winternitz, Luke; Heckler, Gregory; Kurichh, Rishi; Sirotzky, Steve

    2009-01-01

    In 2014. NASA is scheduled to launch the Magnetospheric Multiscale Mission (MMS), a four-satellite formation designed to monitor fluctuations in the Earth's magnetosphere. This mission has two planned phases with different orbits (1? x 12Re and 1.2 x 25Re) to allow for varying science regions of interest. To minimize ground resources and to mitigate the probability of collisions between formation members, an on-board orbit determination system consisting of a Global Positioning System (GPS) receiver and crosslink transceiver was desired. Candidate sensors would be required to acquire GPS signals both below and above the constellation while spinning at three revolutions-per-minute (RPM) and exchanging state and science information among the constellation. The Intersatellite Ranging and Alarm System (IRAS), developed by Goddard Space Flight Center (GSFC) was selected to meet this challenge. IRAS leverages the eight years of development GSFC has invested in the Navigator GPS receiver and its spacecraft communication expertise, culminating in a sensor capable of absolute and relative navigation as well as intersatellite communication. The Navigator is a state-of-the-art receiver designed to acquire and track weak GPS signals down to -147dBm. This innovation allows the receiver to track both the main lobe and the much weaker side lobe signals. The Navigator's four antenna inputs and 24 tracking channels, together with customized hardware and software, allow it to seamlessly maintain visibility while rotating. Additionally, an extended Kalman filter provides autonomous, near real-time, absolute state and time estimates. The Navigator made its maiden voyage on the Space Shuttle during the Hubble Servicing Mission, and is scheduled to fly on MMS as well as the Global Precipitation Measurement Mission (GPM). Additionally, Navigator's acquisition engine will be featured in the receiver being developed for the Orion vehicle. The crosslink transceiver is a 1/4 Watt transmitter

  2. MARS Code in Linux Environment

    Hwang, Moon Kyu; Bae, Sung Won; Jung, Jae Joon; Chung, Bub Dong [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2005-07-01

    The two-phase system analysis code MARS has been incorporated into Linux system. The MARS code was originally developed based on the RELAP5/MOD3.2 and COBRA-TF. The 1-D module which evolved from RELAP5 alone could be applied for the whole NSSS system analysis. The 3-D module developed based on the COBRA-TF, however, could be applied for the analysis of the reactor core region where 3-D phenomena would be better treated. The MARS code also has several other code units that could be incorporated for more detailed analysis. The separate code units include containment analysis modules and 3-D kinetics module. These code modules could be optionally invoked to be coupled with the main MARS code. The containment code modules (CONTAIN and CONTEMPT), for example, could be utilized for the analysis of the plant containment phenomena in a coupled manner with the nuclear reactor system. The mass and energy interaction during the hypothetical coolant leakage accident could, thereby, be analyzed in a more realistic manner. In a similar way, 3-D kinetics could be incorporated for simulating the three dimensional reactor kinetic behavior, instead of using the built-in point kinetics model. The MARS code system, developed initially for the MS Windows environment, however, would not be adequate enough for the PC cluster system where multiple CPUs are available. When parallelism is to be eventually incorporated into the MARS code, MS Windows environment is not considered as an optimum platform. Linux environment, on the other hand, is generally being adopted as a preferred platform for the multiple codes executions as well as for the parallel application. In this study, MARS code has been modified for the adaptation of Linux platform. For the initial code modification, the Windows system specific features have been removed from the code. Since the coupling code module CONTAIN is originally in a form of dynamic load library (DLL) in the Windows system, a similar adaptation method

  3. MARS Code in Linux Environment

    Hwang, Moon Kyu; Bae, Sung Won; Jung, Jae Joon; Chung, Bub Dong

    2005-01-01

    The two-phase system analysis code MARS has been incorporated into Linux system. The MARS code was originally developed based on the RELAP5/MOD3.2 and COBRA-TF. The 1-D module which evolved from RELAP5 alone could be applied for the whole NSSS system analysis. The 3-D module developed based on the COBRA-TF, however, could be applied for the analysis of the reactor core region where 3-D phenomena would be better treated. The MARS code also has several other code units that could be incorporated for more detailed analysis. The separate code units include containment analysis modules and 3-D kinetics module. These code modules could be optionally invoked to be coupled with the main MARS code. The containment code modules (CONTAIN and CONTEMPT), for example, could be utilized for the analysis of the plant containment phenomena in a coupled manner with the nuclear reactor system. The mass and energy interaction during the hypothetical coolant leakage accident could, thereby, be analyzed in a more realistic manner. In a similar way, 3-D kinetics could be incorporated for simulating the three dimensional reactor kinetic behavior, instead of using the built-in point kinetics model. The MARS code system, developed initially for the MS Windows environment, however, would not be adequate enough for the PC cluster system where multiple CPUs are available. When parallelism is to be eventually incorporated into the MARS code, MS Windows environment is not considered as an optimum platform. Linux environment, on the other hand, is generally being adopted as a preferred platform for the multiple codes executions as well as for the parallel application. In this study, MARS code has been modified for the adaptation of Linux platform. For the initial code modification, the Windows system specific features have been removed from the code. Since the coupling code module CONTAIN is originally in a form of dynamic load library (DLL) in the Windows system, a similar adaptation method

  4. Preparing for Mars: The Evolvable Mars Campaign 'Proving Ground' Approach

    Bobskill, Marianne R.; Lupisella, Mark L.; Mueller, Rob P.; Sibille, Laurent; Vangen, Scott; Williams-Byrd, Julie

    2015-01-01

    As the National Aeronautics and Space Administration (NASA) prepares to extend human presence beyond Low Earth Orbit, we are in the early stages of planning missions within the framework of an Evolvable Mars Campaign. Initial missions would be conducted in near-Earth cis-lunar space and would eventually culminate in extended duration crewed missions on the surface of Mars. To enable such exploration missions, critical technologies and capabilities must be identified, developed, and tested. NASA has followed a principled approach to identify critical capabilities and a "Proving Ground" approach is emerging to address testing needs. The Proving Ground is a period subsequent to current International Space Station activities wherein exploration-enabling capabilities and technologies are developed and the foundation is laid for sustained human presence in space. The Proving Ground domain essentially includes missions beyond Low Earth Orbit that will provide increasing mission capability while reducing technical risks. Proving Ground missions also provide valuable experience with deep space operations and support the transition from "Earth-dependence" to "Earth-independence" required for sustainable space exploration. A Technology Development Assessment Team identified a suite of critical technologies needed to support the cadence of exploration missions. Discussions among mission planners, vehicle developers, subject-matter-experts, and technologists were used to identify a minimum but sufficient set of required technologies and capabilities. Within System Maturation Teams, known challenges were identified and expressed as specific performance gaps in critical capabilities, which were then refined and activities required to close these critical gaps were identified. Analysis was performed to identify test and demonstration opportunities for critical technical capabilities across the Proving Ground spectrum of missions. This suite of critical capabilities is expected to

  5. Human Mars Landing Site and Impacts on Mars Surface Operations

    Hoffman, Stephen J.; Bussey, Ben

    2016-01-01

    This paper describes NASA's initial steps for identifying and evaluating candidate Exploration Zones (EZs) and Regions of Interests (ROIs) for the first human crews that will explore the surface of Mars. NASA's current effort to define the exploration of this planet by human crews, known as the Evolvable Mars Campaign (EMC), provides the context in which these EZs and ROIs are being considered. The EMC spans all aspects of a human Mars mission including launch from Earth, transit to and from Mars, and operations on the surface of Mars. An EZ is a collection of ROIs located within approximately 100 kilometers of a centralized landing site. ROIs are areas relevant for scientific investigation and/or development/maturation of capabilities and resources necessary for a sustainable human presence. The EZ also contains one or more landing sites and a habitation site that will be used by multiple human crews during missions to explore and utilize the ROIs within the EZ. With the EMC as a conceptual basis, the EZ model has been refined to a point where specific site selection criteria for scientific exploration and in situ resource utilization can be defined. In 2015 these criteria were distributed to the planetary sciences community and the in situ resource utilization and civil engineering communities as part of a call for EZ proposals. The resulting "First Landing Site/Exploration Zone Workshop for Human Missions to the Surface of Mars" was held in October 2015 during which 47 proposals for EZs and ROIs were presented and discussed. Proposed locations spanned all longitudes and all allowable latitudes (+/- 50 degrees). Proposed justification for selecting one of these EZs also spanned a significant portion of the scientific and resource criteria provided to the community. Several important findings resulted from this Workshop including: (a) a strong consensus that, at a scale of 100 km (radius), multiple places on Mars exist that have both sufficient scientific interest

  6. Digitally programmable microfluidic automaton for multiscale combinatorial mixing and sample processing†

    Jensen, Erik C.; Stockton, Amanda M.; Chiesl, Thomas N.; Kim, Jungkyu; Bera, Abhisek; Mathies, Richard A.

    2013-01-01

    A digitally programmable microfluidic Automaton consisting of a 2-dimensional array of pneumatically actuated microvalves is programmed to perform new multiscale mixing and sample processing operations. Large (µL-scale) volume processing operations are enabled by precise metering of multiple reagents within individual nL-scale valves followed by serial repetitive transfer to programmed locations in the array. A novel process exploiting new combining valve concepts is developed for continuous rapid and complete mixing of reagents in less than 800 ms. Mixing, transfer, storage, and rinsing operations are implemented combinatorially to achieve complex assay automation protocols. The practical utility of this technology is demonstrated by performing automated serial dilution for quantitative analysis as well as the first demonstration of on-chip fluorescent derivatization of biomarker targets (carboxylic acids) for microchip capillary electrophoresis on the Mars Organic Analyzer. A language is developed to describe how unit operations are combined to form a microfluidic program. Finally, this technology is used to develop a novel microfluidic 6-sample processor for combinatorial mixing of large sets (>26 unique combinations) of reagents. The digitally programmable microfluidic Automaton is a versatile programmable sample processor for a wide range of process volumes, for multiple samples, and for different types of analyses. PMID:23172232

  7. Constructing an Educational Mars Simulation

    Henke, Stephen A.

    2004-01-01

    January 14th 2004, President George Bush announces his plans to catalyst the space program into a new era of space exploration and discovery. His vision encompasses a robotics program to explore our solar system, a return to the moon, the human exploration of Mars, and to promote international prosperity towards our endeavors. We at NASA now have the task of constructing this vision in a very real timeframe. I have been chosen to begin phase 1 of making this vision a reality. I will be working on creating an Educational Mars Simulation of human exploration of Mars to stimulate interest and involvement with the project from investors and the community. GRC s Computer Services Division (CSD) in collaboration with the Office of Education Programs will be designing models, constructing terrain, and programming this simulation to create a realistic portrayal of human exploration on mars. With recent and past technological breakthroughs in computing, my primary goal can be accomplished with only the aid of 3-4 software packages. Lightwave 3D is the modeling package we have selected to use for the creation of our digital objects. This includes a Mars pressurized rover, rover cockpit, landscape/terrain, and habitat. Once we have the models completed they need textured so Photoshop and Macromedia Fireworks are handy for bringing these objects to life. Before directly importing all of this data into a simulation environment, it is necessary to first render a stunning animation of the desired final product. This animation with represent what we hope to capture out of the simulation and it will include all of the accessories like ray-tracing, fog effects, shadows, anti-aliasing, particle effects, volumetric lighting, and lens flares. Adobe Premier will more than likely be used for video editing and adding ambient noises and music. Lastly, V-Tree is the real-time 3D graphics engine which will facilitate our realistic simulation. Additional information is included in the

  8. NASA's strategy for Mars exploration in the 1990s and beyond

    Huntress, W. T.; Feeley, T. J.; Boyce, J. M.

    NASA's Office of Space Science is changing its approach to all its missions, both current and future. Budget realities are necessitating that we change the way we do business and the way we look at NASA's role in the U.S. Government. These challenges are being met by a new and innovative approach that focuses on achieving a balanced world-class space science program that requires less U.S. resources while providing an enhanced role for technology and education as integral components of our Research and Development (R&D) programs. Our Mars exploration plans, especially the Mars Surveyor program, are a key feature of this new NASA approach to space science. The Mars Surveyor program will be affordable, engaging to the public with global and close-up images of Mars, have high scientific value, employ a distributed risk strategy (two launches per opportunity), and will use significant advanced technologies.

  9. High performance multi-scale and multi-physics computation of nuclear power plant subjected to strong earthquake. An Overview

    Yoshimura, Shinobu; Kawai, Hiroshi; Sugimoto, Shin'ichiro; Hori, Muneo; Nakajima, Norihiro; Kobayashi, Kei

    2010-01-01

    Recently importance of nuclear energy has been recognized again due to serious concerns of global warming and energy security. In parallel, it is one of critical issues to verify safety capability of ageing nuclear power plants (NPPs) subjected to strong earthquake. Since 2007, we have been developing the multi-scale and multi-physics based numerical simulator for quantitatively predicting actual quake-proof capability of ageing NPPs under operation or just after plant trip subjected to strong earthquake. In this paper, we describe an overview of the simulator with some preliminary results. (author)

  10. Algorithmic foundation of multi-scale spatial representation

    Li, Zhilin

    2006-01-01

    With the widespread use of GIS, multi-scale representation has become an important issue in the realm of spatial data handling. However, no book to date has systematically tackled the different aspects of this discipline. Emphasizing map generalization, Algorithmic Foundation of Multi-Scale Spatial Representation addresses the mathematical basis of multi-scale representation, specifically, the algorithmic foundation.Using easy-to-understand language, the author focuses on geometric transformations, with each chapter surveying a particular spatial feature. After an introduction to the essential operations required for geometric transformations as well as some mathematical and theoretical background, the book describes algorithms for a class of point features/clusters. It then examines algorithms for individual line features, such as the reduction of data points, smoothing (filtering), and scale-driven generalization, followed by a discussion of algorithms for a class of line features including contours, hydrog...

  11. Generalized multiscale finite element method. Symmetric interior penalty coupling

    Efendiev, Yalchin R.; Galvis, Juan; Lazarov, Raytcho D.; Moon, M.; Sarkis, Marcus V.

    2013-01-01

    Motivated by applications to numerical simulations of flows in highly heterogeneous porous media, we develop multiscale finite element methods for second order elliptic equations. We discuss a multiscale model reduction technique in the framework of the discontinuous Galerkin finite element method. We propose two different finite element spaces on the coarse mesh. The first space is based on a local eigenvalue problem that uses an interior weighted L2-norm and a boundary weighted L2-norm for computing the "mass" matrix. The second choice is based on generation of a snapshot space and subsequent selection of a subspace of a reduced dimension. The approximation with these multiscale spaces is based on the discontinuous Galerkin finite element method framework. We investigate the stability and derive error estimates for the methods and further experimentally study their performance on a representative number of numerical examples. © 2013 Elsevier Inc.

  12. Generalized multiscale finite element method. Symmetric interior penalty coupling

    Efendiev, Yalchin R.

    2013-12-01

    Motivated by applications to numerical simulations of flows in highly heterogeneous porous media, we develop multiscale finite element methods for second order elliptic equations. We discuss a multiscale model reduction technique in the framework of the discontinuous Galerkin finite element method. We propose two different finite element spaces on the coarse mesh. The first space is based on a local eigenvalue problem that uses an interior weighted L2-norm and a boundary weighted L2-norm for computing the "mass" matrix. The second choice is based on generation of a snapshot space and subsequent selection of a subspace of a reduced dimension. The approximation with these multiscale spaces is based on the discontinuous Galerkin finite element method framework. We investigate the stability and derive error estimates for the methods and further experimentally study their performance on a representative number of numerical examples. © 2013 Elsevier Inc.

  13. Integrated multiscale biomaterials experiment and modelling: a perspective

    Buehler, Markus J.; Genin, Guy M.

    2016-01-01

    Advances in multiscale models and computational power have enabled a broad toolset to predict how molecules, cells, tissues and organs behave and develop. A key theme in biological systems is the emergence of macroscale behaviour from collective behaviours across a range of length and timescales, and a key element of these models is therefore hierarchical simulation. However, this predictive capacity has far outstripped our ability to validate predictions experimentally, particularly when multiple hierarchical levels are involved. The state of the art represents careful integration of multiscale experiment and modelling, and yields not only validation, but also insights into deformation and relaxation mechanisms across scales. We present here a sampling of key results that highlight both challenges and opportunities for integrated multiscale experiment and modelling in biological systems. PMID:28981126

  14. Complexity multiscale asynchrony measure and behavior for interacting financial dynamics

    Yang, Ge; Wang, Jun; Niu, Hongli

    2016-08-01

    A stochastic financial price process is proposed and investigated by the finite-range multitype contact dynamical system, in an attempt to study the nonlinear behaviors of real asset markets. The viruses spreading process in a finite-range multitype system is used to imitate the interacting behaviors of diverse investment attitudes in a financial market, and the empirical research on descriptive statistics and autocorrelation behaviors of return time series is performed for different values of propagation rates. Then the multiscale entropy analysis is adopted to study several different shuffled return series, including the original return series, the corresponding reversal series, the random shuffled series, the volatility shuffled series and the Zipf-type shuffled series. Furthermore, we propose and compare the multiscale cross-sample entropy and its modification algorithm called composite multiscale cross-sample entropy. We apply them to study the asynchrony of pairs of time series under different time scales.

  15. Study on high density multi-scale calculation technique

    Sekiguchi, S.; Tanaka, Y.; Nakada, H.; Nishikawa, T.; Yamamoto, N.; Yokokawa, M.

    2004-01-01

    To understand degradation of nuclear materials under irradiation, it is essential to know as much about each phenomenon observed from multi-scale points of view; they are micro-scale in atomic-level, macro-level in structural scale and intermediate level. In this study for application to meso-scale materials (100A ∼ 2μm), computer technology approaching from micro- and macro-scales was developed including modeling and computer application using computational science and technology method. And environmental condition of grid technology for multi-scale calculation was prepared. The software and MD (molecular dynamics) stencil for verifying the multi-scale calculation were improved and their movement was confirmed. (A. Hishinuma)

  16. Coherent multiscale image processing using dual-tree quaternion wavelets.

    Chan, Wai Lam; Choi, Hyeokho; Baraniuk, Richard G

    2008-07-01

    The dual-tree quaternion wavelet transform (QWT) is a new multiscale analysis tool for geometric image features. The QWT is a near shift-invariant tight frame representation whose coefficients sport a magnitude and three phases: two phases encode local image shifts while the third contains image texture information. The QWT is based on an alternative theory for the 2-D Hilbert transform and can be computed using a dual-tree filter bank with linear computational complexity. To demonstrate the properties of the QWT's coherent magnitude/phase representation, we develop an efficient and accurate procedure for estimating the local geometrical structure of an image. We also develop a new multiscale algorithm for estimating the disparity between a pair of images that is promising for image registration and flow estimation applications. The algorithm features multiscale phase unwrapping, linear complexity, and sub-pixel estimation accuracy.

  17. Technology needs for manned Mars missions

    Buden, D.; Bartine, D.

    1991-01-01

    As members of the Stafford Synthesis Group, we performed an investigation as to the most expeditious manner to explore Mars. To do this, rationale, objectives, requirements and systems definitions were developed. The objectives include the development of the necessary infrastructure and resources for Mars exploration and performing initial successful exploration of Mars. This will include a transportation system between Mars and Earth, habitats for living on Mars, utilization of Martian resources, and the ability to perform exploration over the entire Martian surface. Using the developed architecture, key technologies were identified. 6 figs., 1 tab

  18. Mars Recent Climate Change Workshop

    Haberle, Robert M.; Owen, Sandra J.

    2012-11-01

    Mars Recent Climate Change Workshop NASA/Ames Research Center May 15-17, 2012 Climate change on Mars has been a subject of great interest to planetary scientists since the 1970's when orbiting spacecraft first discovered fluvial landforms on its ancient surfaces and layered terrains in its polar regions. By far most of the attention has been directed toward understanding how "Early Mars" (i.e., Mars >~3.5 Gya) could have produced environmental conditions favorable for the flow of liquid water on its surface. Unfortunately, in spite of the considerable body of work performed on this subject, no clear consensus has emerged on the nature of the early Martian climate system because of the difficulty in distinguishing between competing ideas given the ambiguities in the available geological, mineralogical, and isotopic records. For several reasons, however, the situation is more tractable for "Recent Mars" (i.e., Mars during past 20 My or so). First, the geologic record is better preserved and evidence for climate change on this time scale has been building since the rejuvenation of the Mars Exploration Program in the late 1990's. The increasing coverage of the planet from orbit and the surface, coupled with accurate measurements of surface topography, increasing spatial resolution of imaging cameras, improved spectral resolution of infrared sensors, and the ability to probe the subsurface with radar, gamma rays, and neutron spectroscopy, has not only improved the characterization of previously known climate features such as polar layered terrains and glacier-related landforms, but has also revealed the existence of many new features related to recent climate change such as polygons, gullies, concentric crater fill, and a latitude dependent mantle. Second, the likely cause of climate change - spin axis/orbital variations - is more pronounced on Mars compared to Earth. Spin axis/orbital variations alter the seasonal and latitudinal distribution of sunlight, which can

  19. CO2 condensation and the climate of early Mars.

    Kasting, J F

    1991-01-01

    A one-dimensional, radiative-convective climate model was used to reexamine the question of whether early Mars could have been kept warm by the greenhouse effect of a dense, CO2 atmosphere. The new model differs from previous models by considering the influence of CO2 clouds on the convective lapse rate and on the the planetary radiation budget. Condensation of CO2 decreases the lapse rate and, hence, reduces the magnitude of the greenhouse effect. This phenomenon becomes increasingly important at low solar luminosities and may preclude warm (0 degree C), globally averaged surface temperatures prior to approximately 2 billion years ago unless other greenhouse gases were present in addition to CO2 and H2O. Alternative mechanisms for warming early Mars and explaining channel formation are discussed.

  20. Detection of Northern Hemisphere transient eddies at Gale Crater Mars

    Haberle, Robert M.; Juárez, Manuel de la Torre; Kahre, Melinda A.; Kass, David M.; Barnes, Jeffrey R.; Hollingsworth, Jeffery L.; Harri, Ari-Matti; Kahanpää, Henrik

    2018-06-01

    The Rover Environmental Monitoring Station (REMS) on the Curiosity Rover is operating in the Southern Hemisphere of Mars and is detecting synoptic period oscillations in the pressure data that we attribute to Northern Hemisphere transient eddies. We base this interpretation on the similarity in the periods of the eddies and their seasonal variations with those observed in northern midlatitudes by Viking Lander 2 (VL-2) 18 Mars years earlier. Further support for this interpretation comes from global circulation modeling which shows similar behavior in the transient eddies at the grid points closest to Curiosity and VL-2. These observations provide the first in situ evidence that the frontal systems often associated with "Flushing Dust Storms" do cross the equator and extend into the Southern Hemisphere.