WorldWideScience

Sample records for continuity mission simulated

  1. Data-driven simulations of the Landsat Data Continuity Mission (LDCM) platform

    Science.gov (United States)

    Gerace, Aaron; Gartley, Mike; Schott, John; Raqueño, Nina; Raqueño, Rolando

    2011-06-01

    The Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) are two new sensors being developed by the Landsat Data Continuity Mission (LDCM) that will extend over 35 years of archived Landsat data. In a departure from the whiskbroom design used by all previous generations of Landsat, the LDCM system will employ a pushbroom technology. Although the newly adopted modular array, pushbroom architecture has several advantages over the previous whiskbroom design, registration of the multi-spectral data products is a concern. In this paper, the Digital Imaging and Remote Sensing Image Generation (DIRSIG) tool was used to simulate an LDCM collection, which gives the team access to data that would not otherwise be available prior to launch. The DIRSIG model was used to simulate the two-instrument LDCM payload in order to study the geometric and radiometric impacts of the sensor design on the proposed processing chain. The Lake Tahoe area located in eastern California was chosen for this work because of its dramatic change in elevation, which was ideal for studying the geometric effects of the new Landsat sensor design. Multi-modal datasets were used to create the Lake Tahoe site model for use in DIRSIG. National Elevation Dataset (NED) data were used to create the digital elevation map (DEM) required by DIRSIG, QuickBird data were used to identify different material classes in the scene, and ASTER and Hyperion spectral data were used to assign radiometric properties to those classes. In order to model a realistic Landsat orbit in these simulations, orbital parameters were obtained from a Landsat 7 two-line element set and propagated with the SGP4 orbital position model. Line-of-sight vectors defining how the individual detector elements of the OLI and TIRS instruments project through the optics were measured and provided by NASA. Additionally, the relative spectral response functions for the 9 bands of OLI and the 2 bands of TIRS were measured and provided by NASA

  2. Landsat Data Continuity Mission

    Science.gov (United States)

    ,

    2012-01-01

    The Landsat Data Continuity Mission (LDCM) is a partnership formed between the National Aeronautics and Space Administration (NASA) and the U.S. Geological Survey (USGS) to place the next Landsat satellite in orbit in January 2013. The Landsat era that began in 1972 will become a nearly 41-year global land record with the successful launch and operation of the LDCM. The LDCM will continue the acquisition, archiving, and distribution of multispectral imagery affording global, synoptic, and repetitive coverage of the Earth's land surfaces at a scale where natural and human-induced changes can be detected, differentiated, characterized, and monitored over time. The mission objectives of the LDCM are to (1) collect and archive medium resolution (30-meter spatial resolution) multispectral image data affording seasonal coverage of the global landmasses for a period of no less than 5 years; (2) ensure that LDCM data are sufficiently consistent with data from the earlier Landsat missions in terms of acquisition geometry, calibration, coverage characteristics, spectral characteristics, output product quality, and data availability to permit studies of landcover and land-use change over time; and (3) distribute LDCM data products to the general public on a nondiscriminatory basis at no cost to the user.

  3. Simulation of Mission Phases

    Science.gov (United States)

    Carlstrom, Nicholas Mercury

    2016-01-01

    Training Materials version 2013.0 release was used to complete the Trick tutorial. Multiple network privilege and repository permission requests were required in order to access previous simulation models. The project was also an introduction to computer programming and the Linux operating system. Basic C++ and Python syntax was used during the completion of the Trick tutorial. Trick's engineering analysis and Monte Carlo simulation capabilities were observed and basic space mission planning procedures were applied in the conceptual design phase. Multiple professional development opportunities were completed in addition to project duties during this internship through the System for Administration, Training, and Education Resources for NASA (SATERN). Topics include: JSC Risk Management Workshop, CCP Risk Management, Basic Radiation Safety Training, X-Ray Radiation Safety, Basic Laser Safety, JSC Export Control, ISS RISE Ambassador, Basic SharePoint 2013, Space Nutrition and Biochemistry, and JSC Personal Protective Equipment. Additionally, this internship afforded the opportunity for formal project presentation and public speaking practice. This was my first experience at a NASA center. After completing this internship I have a much clearer understanding of certain aspects of the agency's processes and procedures, as well as a deeper appreciation from spaceflight simulation design and testing. I will continue to improve my technical skills so that I may have another opportunity to return to NASA and Johnson Space Center.

  4. OMV mission simulator

    Science.gov (United States)

    Cok, Keith E.

    1989-01-01

    The Orbital Maneuvering Vehicle (OMV) will be remotely piloted during rendezvous, docking, or proximity operations with target spacecraft from a ground control console (GCC). The real-time mission simulator and graphics being used to design a console pilot-machine interface are discussed. A real-time orbital dynamics simulator drives the visual displays. The dynamics simulator includes a J2 oblate earth gravity model and a generalized 1962 rotating atmospheric and drag model. The simulator also provides a variable-length communication delay to represent use of the Tracking and Data Relay Satellite System (TDRSS) and NASA Communications (NASCOM). Input parameter files determine the graphics display. This feature allows rapid prototyping since displays can be easily modified from pilot recommendations. A series of pilot reviews are being held to determine an effective pilot-machine interface. Pilots fly missions with nominal to 3-sigma dispersions in translational or rotational axes. Console dimensions, switch type and layout, hand controllers, and graphic interfaces are evaluated by the pilots and the GCC simulator is modified for subsequent runs. Initial results indicate a pilot preference for analog versus digital displays and for two 3-degree-of-freedom hand controllers.

  5. INTEGRITY -- Integrated Human Exploration Mission Simulation Facility

    Science.gov (United States)

    Henninger, D.; Tri, T.; Daues, K.

    It is proposed to develop a high -fidelity ground facil ity to carry out long-duration human exploration mission simulations. These would not be merely computer simulations - they would in fact comprise a series of actual missions that just happen to stay on earth. These missions would include all elements of an actual mission, using actual technologies that would be used for the real mission. These missions would also include such elements as extravehicular activities, robotic systems, telepresence and teleoperation, surface drilling technology--all using a simulated planetary landscape. A sequence of missions would be defined that get progressively longer and more robust, perhaps a series of five or six missions over a span of 10 to 15 years ranging in durat ion from 180 days up to 1000 days. This high-fidelity ground facility would operate hand-in-hand with a host of other terrestrial analog sites such as the Antarctic, Haughton Crater, and the Arizona desert. Of course, all of these analog mission simulations will be conducted here on earth in 1-g, and NASA will still need the Shuttle and ISS to carry out all the microgravity and hypogravity science experiments and technology validations. The proposed missions would have sufficient definition such that definitive requirements could be derived from them to serve as direction for all the program elements of the mission. Additionally, specific milestones would be established for the "launch" date of each mission so that R&D programs would have both good requirements and solid milestones from which to build their implementation plans. Mission aspects that could not be directly incorporated into the ground facility would be simulated via software. New management techniques would be developed for evaluation in this ground test facility program. These new techniques would have embedded metrics which would allow them to be continuously evaluated and adjusted so that by the time the sequence of missions is completed

  6. Landsat Data Continuity Mission - Launch Fever

    Science.gov (United States)

    Irons, James R.; Loveland, Thomas R.; Markham, Brian L.; Masek, Jeffrey G.; Cook, Bruce; Dwyer, John L.

    2012-01-01

    The year 2013 will be an exciting period for those that study the Earth land surface from space, particularly those that observe and characterize land cover, land use, and the change of cover and use over time. Two new satellite observatories will be launched next year that will enhance capabilities for observing the global land surface. The United States plans to launch the Landsat Data Continuity Mission (LDCM) in January. That event will be followed later in the year by the European Space Agency (ESA) launch of the first Sentinel 2 satellite. Considered together, the two satellites will increase the frequency of opportunities for viewing the land surface at a scale where human impact and influence can be differentiated from natural change. Data from the two satellites will provide images for similar spectral bands and for comparable spatial resolutions with rigorous attention to calibration that will facilitate cross comparisons. This presentation will provide an overview of the LDCM satellite system and report its readiness for the January launch.

  7. Ground Contact Model for Mars Science Laboratory Mission Simulations

    Science.gov (United States)

    Raiszadeh, Behzad; Way, David

    2012-01-01

    The Program to Optimize Simulated Trajectories II (POST 2) has been successful in simulating the flight of launch vehicles and entry bodies on earth and other planets. POST 2 has been the primary simulation tool for the Entry Descent, and Landing (EDL) phase of numerous Mars lander missions such as Mars Pathfinder in 1997, the twin Mars Exploration Rovers (MER-A and MER-B) in 2004, Mars Phoenix lander in 2007, and it is now the main trajectory simulation tool for Mars Science Laboratory (MSL) in 2012. In all previous missions, the POST 2 simulation ended before ground impact, and a tool other than POST 2 simulated landing dynamics. It would be ideal for one tool to simulate the entire EDL sequence, thus avoiding errors that could be introduced by handing off position, velocity, or other fight parameters from one simulation to the other. The desire to have one continuous end-to-end simulation was the motivation for developing the ground interaction model in POST 2. Rover landing, including the detection of the postlanding state, is a very critical part of the MSL mission, as the EDL landing sequence continues for a few seconds after landing. The method explained in this paper illustrates how a simple ground force interaction model has been added to POST 2, which allows simulation of the entire EDL from atmospheric entry through touchdown.

  8. Composable Mission Framework for Rapid End-to-End Mission Design and Simulation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation proposed here is the Composable Mission Framework (CMF) a model-based software framework that shall enable seamless continuity of mission design and...

  9. Landsat Data Continuity Mission (LDCM) - Optimizing X-Band Usage

    Science.gov (United States)

    Garon, H. M.; Gal-Edd, J. S.; Dearth, K. W.; Sank, V. I.

    2010-01-01

    The NASA version of the low-density parity check (LDPC) 7/8-rate code, shortened to the dimensions of (8160, 7136), has been implemented as the forward error correction (FEC) schema for the Landsat Data Continuity Mission (LDCM). This is the first flight application of this code. In order to place a 440 Msps link within the 375 MHz wide X band we found it necessary to heavily bandpass filter the satellite transmitter output . Despite the significant amplitude and phase distortions that accompanied the spectral truncation, the mission required BER is maintained at LDPC code and the amplitude and phase compensation provided in the receiver. Similar results were obtained with receivers from several vendors.

  10. Discrete and continuous simulation theory and practice

    CERN Document Server

    Bandyopadhyay, Susmita

    2014-01-01

    When it comes to discovering glitches inherent in complex systems-be it a railway or banking, chemical production, medical, manufacturing, or inventory control system-developing a simulation of a system can identify problems with less time, effort, and disruption than it would take to employ the original. Advantageous to both academic and industrial practitioners, Discrete and Continuous Simulation: Theory and Practice offers a detailed view of simulation that is useful in several fields of study.This text concentrates on the simulation of complex systems, covering the basics in detail and exploring the diverse aspects, including continuous event simulation and optimization with simulation. It explores the connections between discrete and continuous simulation, and applies a specific focus to simulation in the supply chain and manufacturing field. It discusses the Monte Carlo simulation, which is the basic and traditional form of simulation. It addresses future trends and technologies for simulation, with par...

  11. Centralized mission planning and scheduling system for the Landsat Data Continuity Mission

    Science.gov (United States)

    Kavelaars, Alicia; Barnoy, Assaf M.; Gregory, Shawna; Garcia, Gonzalo; Talon, Cesar; Greer, Gregory; Williams, Jason; Dulski, Vicki

    2014-01-01

    Satellites in Low Earth Orbit provide missions with closer range for studying aspects such as geography and topography, but often require efficient utilization of space and ground assets. Optimizing schedules for these satellites amounts to a complex planning puzzle since it requires operators to face issues such as discontinuous ground contacts, limited onboard memory storage, constrained downlink margin, and shared ground antenna resources. To solve this issue for the Landsat Data Continuity Mission (LDCM, Landsat 8), all the scheduling exchanges for science data request, ground/space station contact, and spacecraft maintenance and control will be coordinated through a centralized Mission Planning and Scheduling (MPS) engine, based upon GMV’s scheduling system flexplan9 . The synchronization between all operational functions must be strictly maintained to ensure efficient mission utilization of ground and spacecraft activities while working within the bounds of the space and ground resources, such as Solid State Recorder (SSR) and available antennas. This paper outlines the functionalities that the centralized planning and scheduling system has in its operational control and management of the Landsat 8 spacecraft.

  12. Landsat Data Continuity Mission (LDCM) space to ground mission data architecture

    Science.gov (United States)

    Nelson, Jack L.; Ames, J.A.; Williams, J.; Patschke, R.; Mott, C.; Joseph, J.; Garon, H.; Mah, G.

    2012-01-01

    The Landsat Data Continuity Mission (LDCM) is a scientific endeavor to extend the longest continuous multi-spectral imaging record of Earth's land surface. The observatory consists of a spacecraft bus integrated with two imaging instruments; the Operational Land Imager (OLI), built by Ball Aerospace & Technologies Corporation in Boulder, Colorado, and the Thermal Infrared Sensor (TIRS), an in-house instrument built at the Goddard Space Flight Center (GSFC). Both instruments are integrated aboard a fine-pointing, fully redundant, spacecraft bus built by Orbital Sciences Corporation, Gilbert, Arizona. The mission is scheduled for launch in January 2013. This paper will describe the innovative end-to-end approach for efficiently managing high volumes of simultaneous realtime and playback of image and ancillary data from the instruments to the reception at the United States Geological Survey's (USGS) Landsat Ground Network (LGN) and International Cooperator (IC) ground stations. The core enabling capability lies within the spacecraft Command and Data Handling (C&DH) system and Radio Frequency (RF) communications system implementation. Each of these systems uniquely contribute to the efficient processing of high speed image data (up to 265Mbps) from each instrument, and provide virtually error free data delivery to the ground. Onboard methods include a combination of lossless data compression, Consultative Committee for Space Data Systems (CCSDS) data formatting, a file-based/managed Solid State Recorder (SSR), and Low Density Parity Check (LDPC) forward error correction. The 440 Mbps wideband X-Band downlink uses Class 1 CCSDS File Delivery Protocol (CFDP), and an earth coverage antenna to deliver an average of 400 scenes per day to a combination of LGN and IC ground stations. This paper will also describe the integrated capabilities and processes at the LGN ground stations for data reception using adaptive filtering, and the mission operations approach fro- the LDCM

  13. Architecture oriented modeling and simulation method for combat mission profile

    Directory of Open Access Journals (Sweden)

    CHEN Xia

    2017-05-01

    Full Text Available In order to effectively analyze the system behavior and system performance of combat mission profile, an architecture-oriented modeling and simulation method is proposed. Starting from the architecture modeling,this paper describes the mission profile based on the definition from National Military Standard of China and the US Department of Defense Architecture Framework(DoDAFmodel, and constructs the architecture model of the mission profile. Then the transformation relationship between the architecture model and the agent simulation model is proposed to form the mission profile executable model. At last,taking the air-defense mission profile as an example,the agent simulation model is established based on the architecture model,and the input and output relations of the simulation model are analyzed. It provides method guidance for the combat mission profile design.

  14. Next Generation Simulation Framework for Robotic and Human Space Missions

    Science.gov (United States)

    Cameron, Jonathan M.; Balaram, J.; Jain, Abhinandan; Kuo, Calvin; Lim, Christopher; Myint, Steven

    2012-01-01

    The Dartslab team at NASA's Jet Propulsion Laboratory (JPL) has a long history of developing physics-based simulations based on the Darts/Dshell simulation framework that have been used to simulate many planetary robotic missions, such as the Cassini spacecraft and the rovers that are currently driving on Mars. Recent collaboration efforts between the Dartslab team at JPL and the Mission Operations Directorate (MOD) at NASA Johnson Space Center (JSC) have led to significant enhancements to the Dartslab DSENDS (Dynamics Simulator for Entry, Descent and Surface landing) software framework. The new version of DSENDS is now being used for new planetary mission simulations at JPL. JSC is using DSENDS as the foundation for a suite of software known as COMPASS (Core Operations, Mission Planning, and Analysis Spacecraft Simulation) that is the basis for their new human space mission simulations and analysis. In this paper, we will describe the collaborative process with the JPL Dartslab and the JSC MOD team that resulted in the redesign and enhancement of the DSENDS software. We will outline the improvements in DSENDS that simplify creation of new high-fidelity robotic/spacecraft simulations. We will illustrate how DSENDS simulations are assembled and show results from several mission simulations.

  15. Apollo 16 astronauts in Apollo Command Module Mission Simulator

    Science.gov (United States)

    1972-01-01

    Astronaut Thomas K. Mattingly II, command module pilot of the Apollo 16 lunar landing mission, participates in extravehicular activity (EVA) training in bldg 5 at the Manned Spacecraft Center (MSC). In the right background is Astronaut Charles M. Duke Jr., lunar module pilot. They are inside the Apollo Command Module Mission Simulator (31046); Mattingly (right foreground) and Duke (right backgroung) in the Apollo Command Module Mission Simulator for EVA simulation and training. Astronaut John W. Young, commander, can be seen in the left background (31047).

  16. Modeling and Simulation for Mission Operations Work System Design

    Science.gov (United States)

    Sierhuis, Maarten; Clancey, William J.; Seah, Chin; Trimble, Jay P.; Sims, Michael H.

    2003-01-01

    Work System analysis and design is complex and non-deterministic. In this paper we describe Brahms, a multiagent modeling and simulation environment for designing complex interactions in human-machine systems. Brahms was originally conceived as a business process design tool that simulates work practices, including social systems of work. We describe our modeling and simulation method for mission operations work systems design, based on a research case study in which we used Brahms to design mission operations for a proposed discovery mission to the Moon. We then describe the results of an actual method application project-the Brahms Mars Exploration Rover. Space mission operations are similar to operations of traditional organizations; we show that the application of Brahms for space mission operations design is relevant and transferable to other types of business processes in organizations.

  17. Simulation and debriefing in neonatology 2016: Mission incomplete.

    Science.gov (United States)

    Halamek, Louis P

    2016-11-01

    Simulation can be an effective tool to facilitate the acquisition and maintenance of the cognitive, technical and behavioral skills necessary to carry out our mission in neonatology: the delivery of safe, effective and efficient care to our patients. Prominent examples of successful implementation of simulation within neonatology include the Neonatal Resuscitation Program, the International Pediatric Simulation Society, and the International Network for Simulation-Based Pediatric Innovation, Research and Education. Despite these successes much remains to be accomplished. Expanding simulation beyond technical skill acquisition, using simulated environments to conduct research into human and system performance, incorporating simulation into high-stakes skill assessments, embracing the expertise of the more extensive modeling and simulation community and, in general, applying simulation to healthcare with the same degree of gravitas with which it is deployed in other high-risk industries are all tasks that must be completed in order to achieve our mission. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Guiding Simulations and Experiments using Continuation

    DEFF Research Database (Denmark)

    When applying continuation of periodic solutions to high-dimensional finite element models one might face a dilemma. The mesh resolution and thus the dimension N of the model are typically chosen such that a given computer system can store the information necessary to perform one integration step...... for dimension N, but not for larger dimensions. In other words, a model is usually implemented as a carefully derived implicit integration scheme tailored for numerically stable simulations with the highest spacial resolution admitted by the computational power available. On the other hand, stable numerical...... developed method of control based continuation allows the continuation of periodic solutions without a reduction of the model resolution, and even directly in physical experiments. Moreover, both a simulation as well as an experiment can run asynchronously from the actual continuation method, which...

  19. STS-49 crew in JSC's FB Shuttle Mission Simulator (SMS) during simulation

    Science.gov (United States)

    1992-01-01

    STS-49 Endeavour, Orbiter Vehicle (OV) 105, crewmembers participate in a simulation in JSC's Fixed Base (FB) Shuttle Mission Simulator (SMS) located in the Mission Simulation and Training Facility Bldg 5. Wearing launch and entry suits (LESs) and launch and entry helmets (LEH) and seated on the FB-SMS middeck are (left to right) Mission Specialist (MS) Thomas D. Akers, MS Kathryn C. Thornton, and MS Pierre J. Thuot.

  20. Modeling and Simulation for Multi-Missions Space Exploration Vehicle

    Science.gov (United States)

    Chang, Max

    2011-01-01

    Asteroids and Near-Earth Objects [NEOs] are of great interest for future space missions. The Multi-Mission Space Exploration Vehicle [MMSEV] is being considered for future Near Earth Object missions and requires detailed planning and study of its Guidance, Navigation, and Control [GNC]. A possible mission of the MMSEV to a NEO would be to navigate the spacecraft to a stationary orbit with respect to the rotating asteroid and proceed to anchor into the surface of the asteroid with robotic arms. The Dynamics and Real-Time Simulation [DARTS] laboratory develops reusable models and simulations for the design and analysis of missions. In this paper, the development of guidance and anchoring models are presented together with their role in achieving mission objectives and relationships to other parts of the simulation. One important aspect of guidance is in developing methods to represent the evolution of kinematic frames related to the tasks to be achieved by the spacecraft and its robot arms. In this paper, we compare various types of mathematical interpolation methods for position and quaternion frames. Subsequent work will be on analyzing the spacecraft guidance system with different movements of the arms. With the analyzed data, the guidance system can be adjusted to minimize the errors in performing precision maneuvers.

  1. Mars Exploration Rover Terminal Descent Mission Modeling and Simulation

    Science.gov (United States)

    Raiszadeh, Behzad; Queen, Eric M.

    2004-01-01

    Because of NASA's added reliance on simulation for successful interplanetary missions, the MER mission has developed a detailed EDL trajectory modeling and simulation. This paper summarizes how the MER EDL sequence of events are modeled, verification of the methods used, and the inputs. This simulation is built upon a multibody parachute trajectory simulation tool that has been developed in POST I1 that accurately simulates the trajectory of multiple vehicles in flight with interacting forces. In this model the parachute and the suspended bodies are treated as 6 Degree-of-Freedom (6 DOF) bodies. The terminal descent phase of the mission consists of several Entry, Descent, Landing (EDL) events, such as parachute deployment, heatshield separation, deployment of the lander from the backshell, deployment of the airbags, RAD firings, TIRS firings, etc. For an accurate, reliable simulation these events need to be modeled seamlessly and robustly so that the simulations will remain numerically stable during Monte-Carlo simulations. This paper also summarizes how the events have been modeled, the numerical issues, and modeling challenges.

  2. Mission Assurance Modeling and Simulation: A Cyber Security Roadmap

    Science.gov (United States)

    Gendron, Gerald; Roberts, David; Poole, Donold; Aquino, Anna

    2012-01-01

    This paper proposes a cyber security modeling and simulation roadmap to enhance mission assurance governance and establish risk reduction processes within constrained budgets. The term mission assurance stems from risk management work by Carnegie Mellon's Software Engineering Institute in the late 19905. By 2010, the Defense Information Systems Agency revised its cyber strategy and established the Program Executive Officer-Mission Assurance. This highlights a shift from simply protecting data to balancing risk and begins a necessary dialogue to establish a cyber security roadmap. The Military Operations Research Society has recommended a cyber community of practice, recognizing there are too few professionals having both cyber and analytic experience. The authors characterize the limited body of knowledge in this symbiotic relationship. This paper identifies operational and research requirements for mission assurance M&S supporting defense and homeland security. M&S techniques are needed for enterprise oversight of cyber investments, test and evaluation, policy, training, and analysis.

  3. STS-37 Mission Specialist (MS) Ross during simulation in JSC's FB-SMS

    Science.gov (United States)

    1991-01-01

    STS-37 Mission Specialist (MS) Jerry L. Ross 'borrows' the pilots station to rehearse some of his scheduled duties for his upcoming mission. He is on the flight deck of the fixed-based (FB) shuttle mission simulator (SMS) during this unsuited simulation. The SMS is part of JSC's Mission Simulation and Training Facility Bldg 5.

  4. Using Small UAS for Mission Simulation, Science Validation, and Definition

    Science.gov (United States)

    Abakians, H.; Donnellan, A.; Chapman, B. D.; Williford, K. H.; Francis, R.; Ehlmann, B. L.; Smith, A. T.

    2017-12-01

    Small Unmanned Aerial Systems (sUAS) are increasingly being used across JPL and NASA for science data collection, mission simulation, and mission validation. They can also be used as proof of concept for development of autonomous capabilities for Earth and planetary exploration. sUAS are useful for reconstruction of topography and imagery for a variety of applications ranging from fault zone morphology, Mars analog studies, geologic mapping, photometry, and estimation of vegetation structure. Imagery, particularly multispectral imagery can be used for identifying materials such as fault lithology or vegetation type. Reflectance maps can be produced for wetland or other studies. Topography and imagery observations are useful in radar studies such as from UAVSAR or the future NISAR mission to validate 3D motions and to provide imagery in areas of disruption where the radar measurements decorrelate. Small UAS are inexpensive to operate, reconfigurable, and agile, making them a powerful platform for validating mission science measurements, and also for providing surrogate data for existing or future missions.

  5. Landsat Data Continuity Mission (LDCM) Standard Product Generation and Characteristics

    Science.gov (United States)

    Micijevic, E.; Hayes, R.

    2012-12-01

    prefer uncorrected data a Level 0 Reformatted Product (L0Rp) product will be available. The standard L1T product for L8 will be a 16-bit, north up Universal Transverse Mercator (UTM) projection, Cubic Convolution (CC) resampled, GeoTIFF file. The delivered tar file contains eight 30-meter OlI multispectral bands, one 15-meter OLI Panchromatic band, two TIRS thermal bands, a Quality Band (QB), a metadata file, and an Angle Band. The QB is a file that contains quality statistics from the image data and cloud mask for the scene. The metadata file contains information about the product ordered and is essential for the end user to know how that product was processed. The Angle Band is a binary image file that contains the solar angle information for the scene data collected. The L1T reflectance product bands will be generated with no sun angle correction applied. The angle band will enable an optional TOA reflectance calculation using the sun angles specific to each image pixel. This method was chosen to maintain continuity with Landsat products while allowing the users that require a per pixel sun angle correction to have that capability. An example of a L8 product can be downloaded from the Landsat website located at: http://landsat.usgs.gov/LDCM_DataProduct.php. The sample L8 product was created using Landsat 7 data projected onto a L8 grid and processed to LDCM data product specifications.

  6. Numerical simulation support to the ESA/THOR mission

    Science.gov (United States)

    Valentini, F.; Servidio, S.; Perri, S.; Perrone, D.; De Marco, R.; Marcucci, M. F.; Daniele, B.; Bruno, R.; Camporeale, E.

    2016-12-01

    THOR is a spacecraft concept currently undergoing study phase as acandidate for the next ESA medium size mission M4. THOR has been designedto solve the longstanding physical problems of particle heating andenergization in turbulent plasmas. It will provide high resolutionmeasurements of electromagnetic fields and particle distribution functionswith unprecedented resolution, with the aim of exploring the so-calledkinetic scales. We present the numerical simulation framework which is supporting the THOR mission during the study phase. The THOR teamincludes many scientists developing and running different simulation codes(Eulerian-Vlasov, Particle-In-Cell, Gyrokinetics, Two-fluid, MHD, etc.),addressing the physics of plasma turbulence, shocks, magnetic reconnectionand so on.These numerical codes are being used during the study phase, mainly withthe aim of addressing the following points:(i) to simulate the response of real particle instruments on board THOR, byemploying an electrostatic analyser simulator which mimics the response ofthe CSW, IMS and TEA instruments to the particle velocity distributions ofprotons, alpha particle and electrons, as obtained from kinetic numericalsimulations of plasma turbulence.(ii) to compare multi-spacecraft with single-spacecraft configurations inmeasuring current density, by making use of both numerical models ofsynthetic turbulence and real data from MMS spacecraft.(iii) to investigate the validity of the Taylor hypothesis indifferent configurations of plasma turbulence

  7. STS-37 Mission Specialist (MS) Godwin during simulation in JSC's FB-SMS

    Science.gov (United States)

    1991-01-01

    STS-37 Mission Specialist (MS) Linda M. Godwin rehearses some phases of her scheduled duties on the middeck of the fixed-based (FB) shuttle mission simulator (SMS) located in JSC's Mission Simulation and Training Facility Bldg 5. Godwin is inspecting supplies stowed in the middeck lockers during this unsuited simulation.

  8. Private ground infrastructures for space exploration missions simulations

    Science.gov (United States)

    Souchier, Alain

    2010-06-01

    The Mars Society, a private non profit organisation devoted to promote the red planet exploration, decided to implement simulated Mars habitat in two locations on Earth: in northern Canada on the rim of a meteoritic crater (2000), in a US Utah desert, location of a past Jurassic sea (2001). These habitats have been built with large similarities to actual planned habitats for first Mars exploration missions. Participation is open to everybody either proposing experimentations or wishing only to participate as a crew member. Participants are from different organizations: Mars Society, Universities, experimenters working with NASA or ESA. The general philosophy of the work conducted is not to do an innovative scientific work on the field but to learn how the scientific work is affected or modified by the simulation conditions. Outside activities are conducted with simulated spacesuits limiting the experimenter abilities. Technology or procedures experimentations are also conducted as well as experimentations on the crew psychology and behaviour.

  9. Mission at Mubasi - A Simulation for Leadership Development

    Science.gov (United States)

    Cummings, Pau; Aude, Steven; Fallesen, Jon

    2012-01-01

    The United States Army is investing in simulations as a way of providing practice for leader decision making. Such simulations, grounded in lessons learned from deployment experienced leaders, place less experienced and more junior leaders in challenging situations they might soon be confronted with. And given increased demands on the Army to become more efficient, while maintaining acceptable levels of mission readiness, simulations offer a cost effective complement to live field training. So too, the design parameters of such a simulation can be made to reinforce specific behavior responses which teach leaders known theory and application of effective (and ineffective) decision making. With this in mind, the Center for Army Leadership (CAL) determined that decision-making was of critical importance. Specifically, the following aspects of decision-making were viewed as particularly important for today's Army leaders: 1) Decision dilemmas, in the form of equally appealing or equally unappealing choices, such that there is no clear "right" or "wrong" choice 2) Making decisions with incomplete or ambiguous information, and 3) Predicting and experiencing second- and third-order consequences of decisions. It is decision making in such a setting or environment that Army leaders are increasingly confronted with given the full spectrum of military operations they must be prepared for. This paper details the approach and development of this decision making simulation.

  10. STS-26 MS Hilmers on fixed based (FB) shuttle mission simulator (SMS) middeck

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) David C. Hilmers prepares to ascend a ladder representing the interdeck access hatch from the shuttle middeck to the flight deck. The STS-26 crew is training in the fixed base (FB) shuttle mission simulator (SMS) located in JSC Mission Simulation and Training Facility Bldg 5.

  11. STS-26 MS Lounge in fixed based (FB) shuttle mission simulator (SMS)

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) John M. Lounge, wearing comunications kit assembly headset and crouched on the aft flight deck, performs checklist inspection during training session. The STS-26 crew is training in the fixed base (FB) shuttle mission simulator (SMS) located in JSC Mission Simulation and Training Facility Bldg 5.

  12. Simulation of continuous cast steel product solidification

    Directory of Open Access Journals (Sweden)

    Ardelean, E.

    2007-06-01

    Full Text Available Primary cooling – inside the tundish – has a great impact over the thickness of the solidified steel crust. If on exiting the tundish the crust is too thin, it can punch and break, as a result of the ferrostatic pressure exerted from the inside by the liquid steel as well as because of the weight of the molten steel. The parameters that influence the amount of dissipated heat depend on the cooling water flow of the tundish, on the pressure and temperature of the cooling water but also on the overheating of the continuously cast steel. The secondary cooling takes place at the exit of the semi-finished product from the tundish, when the solidification is supposed to take place all along the cross section of the strand. In order to achieve it, in addition to a correctly managed primary cooling, it is necessary to obtain the proper correlation of the factors that influence the secondary cooling as well: the water flow rate long the three zones of the installation and its pressure in the secondary circuit. All these have in view a proper solidification length; an intense cooling can generate cracks due to the thermal stress, while a too slow cooling can generate a partial solidification of the strand up to the cropping machine area. The paper presents a mathematical simulation of the continuously cast steel solidification.

    El enfriamiento primario del cristalizador tiene una gran importancia sobre el espesor de la costra de acero solidificado. Si al salir del cristalizador, esta costra es demasiado sutil, bajo la acción de la presión ferro estática ejercitada por el acero líquido del interior y gracias el peso propio del hilo, ésta, puede perforar resultando su rompimiento. Los parámetros que influenyen sobre la cantidad de calor cedida dependen del agua de enfriamiento del catalizador, de la presión y de la temperatura de agua de enfriamiento, pero también del sobrecalentamiento del acero fundido continuamente. A la salida del

  13. Performance Simulations for a Spaceborne Methane Lidar Mission

    Science.gov (United States)

    Kiemle, C.; Kawa, Stephan Randolph; Quatrevalet, Mathieu; Browell, Edward V.

    2014-01-01

    Future spaceborne lidar measurements of key anthropogenic greenhouse gases are expected to close current observational gaps particularly over remote, polar, and aerosol-contaminated regions, where actual in situ and passive remote sensing observation techniques have difficulties. For methane, a "Methane Remote Lidar Mission" was proposed by Deutsches Zentrum fuer Luft- und Raumfahrt and Centre National d'Etudes Spatiales in the frame of a German-French climate monitoring initiative. Simulations assess the performance of this mission with the help of Moderate Resolution Imaging Spectroradiometer and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations of the earth's surface albedo and atmospheric optical depth. These are key environmental parameters for integrated path differential absorption lidar which uses the surface backscatter to measure the total atmospheric methane column. Results showthat a lidar with an average optical power of 0.45W at 1.6 µm wavelength and a telescope diameter of 0.55 m, installed on a low Earth orbit platform(506 km), will measure methane columns at precisions of 1.2%, 1.7%, and 2.1% over land, water, and snow or ice surfaces, respectively, for monthly aggregated measurement samples within areas of 50 × 50 km2. Globally, the mean precision for the simulated year 2007 is 1.6%, with a standard deviation of 0.7%. At high latitudes, a lower reflectance due to snow and ice is compensated by denser measurements, owing to the orbital pattern. Over key methane source regions such as densely populated areas, boreal and tropical wetlands, or permafrost, our simulations show that the measurement precision will be between 1 and 2%.

  14. STS-26 MS Nelson on fixed based (FB) shuttle mission simulator (SMS) middeck

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) George D. Nelson trains on the middeck of the fixed based (FB) shuttle mission simulator (SMS). Nelson, wearing communications assembly headset, adjusts camera mounting bracket.

  15. GOCE gravity field simulation based on actual mission scenario

    Science.gov (United States)

    Pail, R.; Goiginger, H.; Mayrhofer, R.; Höck, E.; Schuh, W.-D.; Brockmann, J. M.; Krasbutter, I.; Fecher, T.; Gruber, T.

    2009-04-01

    In the framework of the ESA-funded project "GOCE High-level Processing Facility", an operational hardware and software system for the scientific processing (Level 1B to Level 2) of GOCE data has been set up by the European GOCE Gravity Consortium EGG-C. One key component of this software system is the processing of a spherical harmonic Earth's gravity field model and the corresponding full variance-covariance matrix from the precise GOCE orbit and calibrated and corrected satellite gravity gradiometry (SGG) data. In the framework of the time-wise approach a combination of several processing strategies for the optimum exploitation of the information content of the GOCE data has been set up: The Quick-Look Gravity Field Analysis is applied to derive a fast diagnosis of the GOCE system performance and to monitor the quality of the input data. In the Core Solver processing a rigorous high-precision solution of the very large normal equation systems is derived by applying parallel processing techniques on a PC cluster. Before the availability of real GOCE data, by means of a realistic numerical case study, which is based on the actual GOCE orbit and mission scenario and simulation data stemming from the most recent ESA end-to-end simulation, the expected GOCE gravity field performance is evaluated. Results from this simulation as well as recently developed features of the software system are presented. Additionally some aspects on data combination with complementary data sources are addressed.

  16. Judicious Use of Simulation Technology in Continuing Medical Education

    Science.gov (United States)

    Curtis, Michael T.; DiazGranados, Deborah; Feldman, Moshe

    2012-01-01

    Use of simulation-based training is fast becoming a vital source of experiential learning in medical education. Although simulation is a common tool for undergraduate and graduate medical education curricula, the utilization of simulation in continuing medical education (CME) is still an area of growth. As more CME programs turn to simulation to…

  17. ''NEPTUNIX'': a continuous system simulation language

    International Nuclear Information System (INIS)

    Nakhle, Michel; Roux, Pierre.

    1982-07-01

    From the mathematical description of a physical system, NEPTUNIX builds the corresponding simulator. Algebraic and ordinary differential equations describing a physical system may be ''stiff'', nonlinear, implicit and even dynamically variable. The non procedural language describing the mathematical model is independent from the integration algorithm. The NEPTUNIX built simulator, transportable on many computers, may be controlled by a userfriendly operating language, independent from host computer and integration method. Last years results about numerical and non-numerical algorithms were used for the package implementation. NEPTUNIX appears as a powerful modeling tool, specially in the field of nuclear reactors design [fr

  18. STS-37 crewmembers train in JSC's FB shuttle mission simulator (SMS)

    Science.gov (United States)

    1991-01-01

    STS-37 Commander Steven R. Nagel (left) and Mission Specialist (MS) Jerry L. Ross rehearse some of their scheduled duties on the flight deck of JSC's fixed-based (FB) shuttle mission simulator (SMS) located in the Mission Simulation and Training Facility Bldg 5. During the unsuited simulation, Nagel reviews checklist while seated at the commanders station as Ross looks on from the pilots station.

  19. STS-26 crew trains in JSC fixed-based (FB) shuttle mission simulator (SMS)

    Science.gov (United States)

    1987-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, crewmembers (left to right) Commander Frederick H. Hauck, Pilot Richard O. Covey, Mission Specialist (MS) George D. Nelson, MS David C. Hilmers, and MS John M. Lounge pose on the middeck in fixed-based (FB) shuttle mission simulator (SMS) located in JSC Mission Simulation and Training Facility Bldg 5. A simulation for their anticipated June 1988 flight began 10-20-87.

  20. Airborne Instrument Simulator for the Lidar Surface Topography (LIST) Mission

    Science.gov (United States)

    Yu, Anthony W.; Krainak, Michael A.; Harding, David J.; Abshire, James B.; Sun, Xiaoli; Cavanaugh, John; Valett, Susan; Ramos-Izquierdo, Luis

    2010-01-01

    In 2007, the National Research Council (NRC) completed its first decadal survey for Earth science at the request of NASA, NOAA, and USGS. The Lidar Surface Topography (LIST) mission is one of fifteen missions recommended by NRC, whose primary objectives are to map global topography and vegetation structure at 5 m spatial resolution, and to acquire global coverage with a few years. NASA Goddard conducted an initial mission concept study for the LIST mission 2007, and developed the initial measurement requirements for the mission.

  1. Airborne Lidar Simulator for the Lidar Surface Topography (LIST) Mission

    Science.gov (United States)

    Yu, Anthony W.; Krainak, Michael A.; Abshire, James B.; Cavanaugh, John; Valett, Susan; Ramos-Izquierdo, Luis

    2010-01-01

    In 2007, the National Research Council (NRC) completed its first decadal survey for Earth science at the request of NASA, NOAA, and USGS. The Lidar Surface Topography (LIST) mission is one of fifteen missions recommended by NRC, whose primary objectives are to map global topography and vegetation structure at 5 m spatial resolution, and to acquire global surface height mapping within a few years. NASA Goddard conducted an initial mission concept study for the LIST mission in 2007, and developed the initial measurement requirements for the mission.

  2. STS-36 crewmembers train in JSC's FB shuttle mission simulator (SMS)

    Science.gov (United States)

    1989-01-01

    STS-36 Mission Specialist (MS) David C. Hilmers, seated on the aft flight deck, discusses procedures with Commander John O. Creighton (left) and Pilot John H. Casper during a simulation in JSC's Fixed Based (FB) Shuttle Mission Simulator (SMS). Casper reviews a checklist at the pilots station on the forward flight deck. The crewmembers are rehearsing crew cabin activities for their upcoming Department of Defense (DOD) mission aboard Atlantis, Orbiter Vehicle (OV) 104.

  3. STS-26 crew on fixed based (FB) shuttle mission simulator (SMS) flight deck

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Commander Frederick H. Hauck (left) and Pilot Richard O. Covey review checklists in their respective stations on the foward flight deck. The STS-26 crew is training in the fixed base (FB) shuttle mission simulator (SMS) located in JSC Mission Simulation and Training Facility Bldg 5.

  4. Sleep and cognitive function of crewmembers and mission controllers working 24-h shifts during a simulated 105-day spaceflight mission

    Science.gov (United States)

    Barger, Laura K.; Wright, Kenneth P.; Burke, Tina M.; Chinoy, Evan D.; Ronda, Joseph M.; Lockley, Steven W.; Czeisler, Charles A.

    2014-01-01

    The success of long-duration space missions depends on the ability of crewmembers and mission support specialists to be alert and maintain high levels of cognitive function while operating complex, technical equipment. We examined sleep, nocturnal melatonin levels and cognitive function of crewmembers and the sleep and cognitive function of mission controllers who participated in a high-fidelity 105-day simulated spaceflight mission at the Institute of Biomedical Problems (Moscow). Crewmembers were required to perform daily mission duties and work one 24-h extended duration work shift every sixth day. Mission controllers nominally worked 24-h extended duration shifts. Supplemental lighting was provided to crewmembers and mission controllers. Participants' sleep was estimated by wrist-actigraphy recordings. Overall, results show that crewmembers and mission controllers obtained inadequate sleep and exhibited impaired cognitive function, despite countermeasure use, while working extended duration shifts. Crewmembers averaged 7.04±0.92 h (mean±SD) and 6.94±1.08 h (mean±SD) in the two workdays prior to the extended duration shifts, 1.88±0.40 h (mean±SD) during the 24-h work shift, and then slept 10.18±0.96 h (mean±SD) the day after the night shift. Although supplemental light was provided, crewmembers' average nocturnal melatonin levels remained elevated during extended 24-h work shifts. Naps and caffeine use were reported by crewmembers during ˜86% and 45% of extended night work shifts, respectively. Even with reported use of wake-promoting countermeasures, significant impairments in cognitive function were observed. Mission controllers slept 5.63±0.95 h (mean±SD) the night prior to their extended duration work shift. On an average, 89% of night shifts included naps with mission controllers sleeping an average of 3.4±1.0 h (mean±SD) during the 24-h extended duration work shift. Mission controllers also showed impaired cognitive function during extended

  5. Testing VGT data continuity between SPOT and PROBA-V missions for operational yield forecasting in North African countries

    OpenAIRE

    MERONI MICHELE; FASBENDER DOMINIQUE; BALAGHI Raid; DALI Mustapha; HAFANI Miriam; HAYTHEM Ismael; HOOKER JOSEPH DOMINIC; LAHLOU Mouanis; LOPEZ LOZANO RAUL; MAHYOU Hamid; MONCEF Ben Moussa; SGHAIER Nabil; WAFA Talhaoui; LEO Olivier

    2015-01-01

    The SPOT-VEGETATION mission operationally provided 15 years of remote sensing indicators of vegetation status. The mission reached its end-of-life in May 2014 and was timely replaced by the PROBA-V mission, aiming to ensure, among other objectives, the seamless continuity of provision of VGT-like products, including Normalized Difference Vegetation Index (NDVI). Exploiting the period of overlap when both instruments were functioning (November 2013 –May 2014), this study compared NDVI data ...

  6. Noise Simulation of Continuous-Time ΣΔ Modulators

    International Nuclear Information System (INIS)

    Arias, J.; Quintanilla, L.; Bisbal, D.; San Pablo, J.; Enriquez, L.; Vicente, J.; Barbolla, J.

    2005-01-01

    In this work, an approach for the simulation of the effect of noise sources in the performance of continuous-time ΔΣ modulators is presented. Electrical noise including thermal noise, 1/f noise and clock jitter are included in a simulation program and their impact on the system performance is analyzed

  7. Judicious use of simulation technology in continuing medical education.

    Science.gov (United States)

    Curtis, Michael T; DiazGranados, Deborah; Feldman, Moshe

    2012-01-01

    Use of simulation-based training is fast becoming a vital source of experiential learning in medical education. Although simulation is a common tool for undergraduate and graduate medical education curricula, the utilization of simulation in continuing medical education (CME) is still an area of growth. As more CME programs turn to simulation to address their training needs, it is important to highlight concepts of simulation technology that can help to optimize learning outcomes. This article discusses the role of fidelity in medical simulation. It provides support from a cross section of simulation training domains for determining the appropriate levels of fidelity, and it offers guidelines for creating an optimal balance of skill practice and realism for efficient training outcomes. After defining fidelity, 3 dimensions of fidelity, drawn from the human factors literature, are discussed in terms of their relevance to medical simulation. From this, research-based guidelines are provided to inform CME providers regarding the use of simulation in CME training. Copyright © 2012 The Alliance for Continuing Education in the Health Professions, the Society for Academic Continuing Medical Education, and the Council on CME, Association for Hospital Medical Education.

  8. Phobos Environment Model and Regolith Simulant for MMX Mission

    Science.gov (United States)

    Miyamoto, H.; Niihara, T.; Wada, K.; Ogawa, K.; Baresi, N.; Abell, Paul A.; Asphaug, E.; Britt, D.; Dodbiba, G.; Fujita, T.; hide

    2018-01-01

    Phobos and Deimos, the two moons of Mars, are considered to be scientifically important and potential human mission's target. Martian Moons eXplorer (MMX) is the JAXA's mission to explore Phobos (and/or Deimos), which is scheduled to be launched in 2024. The main spacecraft of MMX will perform in-situ observations of both Phobos and Deimos, land on one of them (most likely, Phobos), and bring samples back to Earth. Small landing modules may be included in the mission as for the Hayabusa-2 mission. The designs of both the landing and sampling devices depend largely on the surface conditions of the target body and on how this surface reacts to an external action in the low gravity conditions of the target. Thus, the Landing Operation Working Team (LOWT) of MMX, which is composed of both scientists and engineers, is studying Phobos' surface based on previous observations and theoretical/experimental considerations. Though engineering motivation initiated this activity, the results will be extremely useful for scientific purposes.

  9. Enhancing a Simple MODIS Cloud Mask Algorithm for the Landsat Data Continuity Mission

    Science.gov (United States)

    Wilson, Michael J.; Oreopoulos, Lazarous

    2011-01-01

    The presence of clouds in images acquired by the Landsat series of satellites is usually an undesirable, but generally unavoidable fact. With the emphasis of the program being on land imaging, the suspended liquid/ice particles of which clouds are made of fully or partially obscure the desired observational target. Knowing the amount and location of clouds in a Landsat scene is therefore valuable information for scene selection, for making clear-sky composites from multiple scenes, and for scheduling future acquisitions. The two instruments in the upcoming Landsat Data Continuity Mission (LDCM) will include new channels that will enhance our ability to detect high clouds which are often also thin in the sense that a large fraction of solar radiation can pass through them. This work studies the potential impact of these new channels on enhancing LDCM's cloud detection capabilities compared to previous Landsat missions. We revisit a previously published scheme for cloud detection and add new tests to capture more of the thin clouds that are harder to detect with the more limited arsenal channels. Since there are no Landsat data yet that include the new LDCM channels, we resort to data from another instrument, MODIS, which has these bands, as well as the other bands of LDCM, to test the capabilities of our new algorithm. By comparing our revised scheme's performance against the performance of the official MODIS cloud detection scheme, we conclude that the new scheme performs better than the earlier scheme which was not very good at thin cloud detection.

  10. Continuing our organizational mission: A new name for a new time.

    Science.gov (United States)

    Walker, Deborah Klein; Kilmer, Ryan P; Armstrong, Mary I

    2017-01-01

    This editorial explains the need for a new name for the American Orthopsychiatric Association (ORTHO). As ORTHO continues their work into the 21st century, they want to better reflect their global membership and focus, increasing the number of partnerships with individuals and organizations, and commitment to a just society. Therefore, ORTHO is changing their name to the Global Alliance for Behavioral Health and Social Justice. It is crucial to underscore that, although the organizations name is changing, the values and principles that inform their work will remain the same. The mission statement of the Global Alliance for Behavioral Health and Social Justice is "to inform policy, practice, and research to prevent behavioral health disorders and to promote conditions to ensure that people with disorders can be full participants in society." (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  11. DYNAMIC SIMULATION AND FUZZY CONTROL OF A CONTINUOUS DISTILLATION COLUMN

    OpenAIRE

    Arbildo López, A.; Lombira Echevarría, J.; Osario López, l.

    2014-01-01

    The objective of this work is the study of the dinamic simulation and fuzzy control of a multicomponent continuous distillation column. In this work, the mathematical model of the distillation column and the computing program for the simulation are described. Also, the structure and implementation of the fuzzy controller are presentad. Finally, the results obtained using this programare compared with those reported in the scientific literature for different mixtures. El objetivo de nuestra...

  12. STS-29 Commander Coats in JSC fixed base (FB) shuttle mission simulator (SMS)

    Science.gov (United States)

    1986-01-01

    STS-29 Discovery, Orbiter Vehicle (OV) 103, Commander Michael L. Coats sits at commanders station forward flight deck controls in JSC fixed base (FB) shuttle mission simulator (SMS). Coats, wearing communications kit assembly headset and flight coveralls, looks away from forward control panels to aft flight deck. Pilots station seat back appears in foreground. FB-SMS is located in JSC Mission Simulation and Training Facility Bldg 5.

  13. STS-26 Commander Hauck in fixed based (FB) shuttle mission simulator (SMS)

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Commander Frederick H. Hauck, wearing comunications kit assembly headset and seated in the commanders seat on forward flight deck, looks over his shoulder toward the aft flight deck. A flight data file (FDF) notebook rests on his lap. The STS-26 crew is training in the fixed base (FB) shuttle mission simulator (SMS) located in JSC Mission Simulation and Training Facility Bldg 5.

  14. Discrete Event Simulation of a Suppression of Enemy Air Defenses (SEAD) Mission

    National Research Council Canada - National Science Library

    Candir, Ahmet A

    2008-01-01

    ...) operations have been a crucial element of military air power for 50 years. Several developments and evolution in both air defense and attack systems suggest that SEAD missions will continue to have growing importance to air forces...

  15. STS-57 crewmembers train in JSC's FB Shuttle Mission Simulator (SMS)

    Science.gov (United States)

    1993-01-01

    STS-57 Endeavour, Orbiter Vehicle (OV) 105, Mission Specialist 2 (MS2) Nancy J. Sherlock, holding computer diskettes and procedural checklist, discusses equipment operation with Commander Ronald J. Grabe on the middeck of JSC's fixed based (FB) shuttle mission simulator (SMS). Payload Commander (PLC) G. David Low points to a forward locker location as MS3 Peter J.K. Wisoff switches controls on overhead panels MO42F and MO58F, and MS4 Janice E. Voss looks on. The FB-SMS is located in the Mission Simulation and Training Facility Bldg 5.

  16. Model-Based GN and C Simulation and Flight Software Development for Orion Missions beyond LEO

    Science.gov (United States)

    Odegard, Ryan; Milenkovic, Zoran; Henry, Joel; Buttacoli, Michael

    2014-01-01

    For Orion missions beyond low Earth orbit (LEO), the Guidance, Navigation, and Control (GN&C) system is being developed using a model-based approach for simulation and flight software. Lessons learned from the development of GN&C algorithms and flight software for the Orion Exploration Flight Test One (EFT-1) vehicle have been applied to the development of further capabilities for Orion GN&C beyond EFT-1. Continuing the use of a Model-Based Development (MBD) approach with the Matlab®/Simulink® tool suite, the process for GN&C development and analysis has been largely improved. Furthermore, a model-based simulation environment in Simulink, rather than an external C-based simulation, greatly eases the process for development of flight algorithms. The benefits seen by employing lessons learned from EFT-1 are described, as well as the approach for implementing additional MBD techniques. Also detailed are the key enablers for improvements to the MBD process, including enhanced configuration management techniques for model-based software systems, automated code and artifact generation, and automated testing and integration.

  17. DYSIM - A Modular Simulation System for Continuous Dynamic Processes

    DEFF Research Database (Denmark)

    Christensen, P. la Cour; Kofoed, J. E.; Larsen, N.

    1986-01-01

    The report describes a revised version of a simulation system for continuous processes, DYSIM. In relation to the previous version, which was developed in 1981, the main changes are conversion to Fortran 77 and introduction of a modular structure. The latter feature gives the user a possibility...

  18. Simulations of nonlinear continuous wave pressure fields in FOCUS

    Science.gov (United States)

    Zhao, Xiaofeng; Hamilton, Mark F.; McGough, Robert J.

    2017-03-01

    The Khokhlov - Zabolotskaya - Kuznetsov (KZK) equation is a parabolic approximation to the Westervelt equation that models the effects of diffraction, attenuation, and nonlinearity. Although the KZK equation is only valid in the far field of the paraxial region for mildly focused or unfocused transducers, the KZK equation is widely applied in medical ultrasound simulations. For a continuous wave input, the KZK equation is effectively modeled by the Bergen Code [J. Berntsen, Numerical Calculations of Finite Amplitude Sound Beams, in M. F. Hamilton and D. T. Blackstock, editors, Frontiers of Nonlinear Acoustics: Proceedings of 12th ISNA, Elsevier, 1990], which is a finite difference model that utilizes operator splitting. Similar C++ routines have been developed for FOCUS, the `Fast Object-Oriented C++ Ultrasound Simulator' (http://www.egr.msu.edu/˜fultras-web) to calculate nonlinear pressure fields generated by axisymmetric flat circular and spherically focused ultrasound transducers. This new routine complements an existing FOCUS program that models nonlinear ultrasound propagation with the angular spectrum approach [P. T. Christopher and K. J. Parker, J. Acoust. Soc. Am. 90, 488-499 (1991)]. Results obtained from these two nonlinear ultrasound simulation approaches are evaluated and compared for continuous wave linear simulations. The simulation results match closely in the farfield of the paraxial region, but the results differ in the nearfield. The nonlinear pressure field generated by a spherically focused transducer with a peak surface pressure of 0.2MPa radiating in a lossy medium with β = 3.5 is simulated, and the computation times are also evaluated. The nonlinear simulation results demonstrate acceptable agreement in the focal zone. These two related nonlinear simulation approaches are now included with FOCUS to enable convenient simulations of nonlinear pressure fields on desktop and laptop computers.

  19. Simulation Approach to Mission Risk and Reliability Analysis, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — It is proposed to develop and demonstrate an integrated total-system risk and reliability analysis approach that is based on dynamic, probabilistic simulation. This...

  20. Mission simulation as an approach to develop requirements for automation in Advanced Life Support Systems

    Science.gov (United States)

    Erickson, J. D.; Eckelkamp, R. E.; Barta, D. J.; Dragg, J.; Henninger, D. L. (Principal Investigator)

    1996-01-01

    This paper examines mission simulation as an approach to develop requirements for automation and robotics for Advanced Life Support Systems (ALSS). The focus is on requirements and applications for command and control, control and monitoring, situation assessment and response, diagnosis and recovery, adaptive planning and scheduling, and other automation applications in addition to mechanized equipment and robotics applications to reduce the excessive human labor requirements to operate and maintain an ALSS. Based on principles of systems engineering, an approach is proposed to assess requirements for automation and robotics using mission simulation tools. First, the story of a simulated mission is defined in terms of processes with attendant types of resources needed, including options for use of automation and robotic systems. Next, systems dynamics models are used in simulation to reveal the implications for selected resource allocation schemes in terms of resources required to complete operational tasks. The simulations not only help establish ALSS design criteria, but also may offer guidance to ALSS research efforts by identifying gaps in knowledge about procedures and/or biophysical processes. Simulations of a planned one-year mission with 4 crewmembers in a Human Rated Test Facility are presented as an approach to evaluation of mission feasibility and definition of automation and robotics requirements.

  1. Battery Simulation Tool for Worst Case Analysis and Mission Evaluations

    Directory of Open Access Journals (Sweden)

    Lefeuvre Stéphane

    2017-01-01

    The first part of this paper presents the PSpice models including their respective variable parameters at SBS and cell level. Then the second part of the paper introduces to the reader the model parameters that were chosen and identified to perform Monte Carlo Analysis simulations. The third part reflects some MCA results for a VES16 battery module. Finally the reader will see some other simulations that were performed by re-using the battery model for an another Saft battery cell type (MP XTD for a specific space application, at high temperature.

  2. 3D Printed Surgical Instruments Evaluated by a Simulated Crew of a Mars Mission.

    Science.gov (United States)

    Wong, Julielynn Y; Pfahnl, Andreas C

    2016-09-01

    The first space-based fused deposition modeling (FDM) 3D printer became operational in 2014. This study evaluated whether Mars simulation crewmembers of the Hawai'i Space Exploration Analog and Simulation (HI-SEAS) II mission with no prior surgical experience could utilize acrylonitrile butadiene styrene (ABS) thermoplastic surgical instruments FDM 3D printed on Earth to complete simulated surgical tasks. This study sought to examine the feasibility of using 3D printed surgical tools when the primary crew medical officer is incapacitated and the back-up crew medical officer must conduct a surgical procedure during a simulated extended space mission. During a 4 mo duration ground-based analog mission, five simulation crewmembers with no prior surgical experience completed 16 timed sets of simulated prepping, draping, incising, and suturing tasks to evaluate the relative speed of using four ABS thermoplastic instruments printed on Earth compared to conventional instruments. All four simulated surgical tasks were successfully performed using 3D printed instruments by Mars simulation crewmembers with no prior surgical experience. There was no substantial difference in time to completion of simulated tasks with control vs. 3D printed sponge stick, towel clamp, scalpel handle, and toothed forceps. These limited findings support further investigation into the creation of an onboard digital catalog of validated 3D printable surgical instrument design files to support autonomous, crew-administered healthcare on Mars missions. Future work could include addressing sterility, biocompatibility, and having astronaut crew medical officers test a wider range of surgical instruments printed in microgravity during actual surgical procedures. Wong JY, Pfahnl AC. 3D printed surgical instruments evaluated by a simulated crew of a Mars mission. Aerosp Med Hum Perform. 2016; 87(9):806-810.

  3. Development of the Landsat Data Continuity Mission Cloud Cover Assessment Algorithms

    Science.gov (United States)

    Scaramuzza, Pat; Bouchard, M.A.; Dwyer, John L.

    2012-01-01

    The upcoming launch of the Operational Land Imager (OLI) will start the next era of the Landsat program. However, the Automated Cloud-Cover Assessment (CCA) (ACCA) algorithm used on Landsat 7 requires a thermal band and is thus not suited for OLI. There will be a thermal instrument on the Landsat Data Continuity Mission (LDCM)-the Thermal Infrared Sensor-which may not be available during all OLI collections. This illustrates a need for CCA for LDCM in the absence of thermal data. To research possibilities for full-resolution OLI cloud assessment, a global data set of 207 Landsat 7 scenes with manually generated cloud masks was created. It was used to evaluate the ACCA algorithm, showing that the algorithm correctly classified 79.9% of a standard test subset of 3.95 109 pixels. The data set was also used to develop and validate two successor algorithms for use with OLI data-one derived from an off-the-shelf machine learning package and one based on ACCA but enhanced by a simple neural network. These comprehensive CCA algorithms were shown to correctly classify pixels as cloudy or clear 88.5% and 89.7% of the time, respectively.

  4. Novel roaming and stationary tethered aerial robots for continuous mobile missions in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Beom W.; Choi, Su Y.; Rim, Chun T. [Dept. of Nuclear and Quantum Engineering, KAIST, Daejeon (Korea, Republic of); Choi, Young Soo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cai, Guowei; Seneviratne, Lakmal [Dept. of Aerospace Engineering, Khalifa University, Abu Dhabi (United Arab Emirates)

    2016-08-15

    In this paper, new tethered aerial robots including roaming tethered aerial robots (RTARs) for radioactive material sampling and stationary tethered aerial robots (STARs) for environment monitoring are proposed to meet extremely-long-endurance missions of nuclear power plants. The flight of the proposed tethered aerial robots may last for a few days or even a few months as long as the tethered cable provides continuous power. A high voltage AC or DC power system was newly adopted to reduce the mass of the tethered cable. The RTAR uses a tethered cable spooled from the aerial robot and an aerial tension control system. The aerial tension control system provides the appropriate tension to the tethered cable, which is accordingly laid down on the ground as the RTAR roams. The STAR includes a tethered cable spooled from the ground and a ground tension control system, which enables the STAR to reach high altitudes. Prototypes of the RTAR and STAR were designed and successfully demonstrated in outdoor environments, where the load power, power type, operating frequency, and flight attitude of the RTAR and STAR were: 180 W, AC 100 kHz, and 20 m; and 300 W, AC or DC 100 kHz, and 80 m, respectively.

  5. Novel Roaming and Stationary Tethered Aerial Robots for Continuous Mobile Missions in Nuclear Power Plants

    Directory of Open Access Journals (Sweden)

    Beom W. Gu

    2016-08-01

    Full Text Available In this paper, new tethered aerial robots including roaming tethered aerial robots (RTARs for radioactive material sampling and stationary tethered aerial robots (STARs for environment monitoring are proposed to meet extremely-long-endurance missions of nuclear power plants. The flight of the proposed tethered aerial robots may last for a few days or even a few months as long as the tethered cable provides continuous power. A high voltage AC or DC power system was newly adopted to reduce the mass of the tethered cable. The RTAR uses a tethered cable spooled from the aerial robot and an aerial tension control system. The aerial tension control system provides the appropriate tension to the tethered cable, which is accordingly laid down on the ground as the RTAR roams. The STAR includes a tethered cable spooled from the ground and a ground tension control system, which enables the STAR to reach high altitudes. Prototypes of the RTAR and STAR were designed and successfully demonstrated in outdoor environments, where the load power, power type, operating frequency, and flight attitude of the RTAR and STAR were: 180 W, AC 100 kHz, and 20 m; and 300 W, AC or DC 100 kHz, and 80 m, respectively.

  6. Parallel algorithms for simulating continuous time Markov chains

    Science.gov (United States)

    Nicol, David M.; Heidelberger, Philip

    1992-01-01

    We have previously shown that the mathematical technique of uniformization can serve as the basis of synchronization for the parallel simulation of continuous-time Markov chains. This paper reviews the basic method and compares five different methods based on uniformization, evaluating their strengths and weaknesses as a function of problem characteristics. The methods vary in their use of optimism, logical aggregation, communication management, and adaptivity. Performance evaluation is conducted on the Intel Touchstone Delta multiprocessor, using up to 256 processors.

  7. Psychological and behavioral changes during confinement in a 520-day simulated interplanetary mission to mars.

    Directory of Open Access Journals (Sweden)

    Mathias Basner

    Full Text Available Behavioral health risks are among the most serious and difficult to mitigate risks of confinement in space craft during long-duration space exploration missions. We report on behavioral and psychological reactions of a multinational crew of 6 healthy males confined in a 550 m(3 chamber for 520 days during the first Earth-based, high-fidelity simulated mission to Mars. Rest-activity of crewmembers was objectively measured throughout the mission with wrist-worn actigraphs. Once weekly throughout the mission crewmembers completed the Beck Depression Inventory-II (BDI-II, Profile of Moods State short form (POMS, conflict questionnaire, the Psychomotor Vigilance Test (PVT-B, and series of visual analogue scales on stress and fatigue. We observed substantial inter-individual differences in the behavioral responses of crewmembers to the prolonged mission confinement and isolation. The crewmember with the highest average POMS total mood disturbance score throughout the mission also reported symptoms of depression in 93% of mission weeks, which reached mild-to-moderate levels in >10% of mission weeks. Conflicts with mission control were reported five times more often than conflicts among crewmembers. Two crewmembers who had the highest ratings of stress and physical exhaustion accounted for 85% of the perceived conflicts. One of them developed a persistent sleep onset insomnia with ratings of poor sleep quality, which resulted in chronic partial sleep deprivation, elevated ratings of daytime tiredness, and frequent deficits in behavioral alertness. Sleep-wake timing was altered in two other crewmembers, beginning in the first few months of the mission and persisting throughout. Two crewmembers showed neither behavioral disturbances nor reports of psychological distress during the 17-month period of mission confinement. These results highlight the importance of identifying behavioral, psychological, and biological markers of characteristics that

  8. Simulation of dilated heart failure with continuous flow circulatory support.

    Directory of Open Access Journals (Sweden)

    Yajuan Wang

    Full Text Available Lumped parameter models have been employed for decades to simulate important hemodynamic couplings between a left ventricular assist device (LVAD and the native circulation. However, these studies seldom consider the pathological descending limb of the Frank-Starling response of the overloaded ventricle. This study introduces a dilated heart failure model featuring a unimodal end systolic pressure-volume relationship (ESPVR to address this critical shortcoming. The resulting hemodynamic response to mechanical circulatory support are illustrated through numerical simulations of a rotodynamic, continuous flow ventricular assist device (cfVAD coupled to systemic and pulmonary circulations with baroreflex control. The model further incorporated septal interaction to capture the influence of left ventricular (LV unloading on right ventricular function. Four heart failure conditions were simulated (LV and bi-ventricular failure with/without pulmonary hypertension in addition to normal baseline. Several metrics of LV function, including cardiac output and stroke work, exhibited a unimodal response whereby initial unloading improved function, and further unloading depleted preload reserve thereby reducing ventricular output. The concept of extremal loading was introduced to reflect the loading condition in which the intrinsic LV stroke work is maximized. Simulation of bi-ventricular failure with pulmonary hypertension revealed inadequacy of LV support alone. These simulations motivate the implementation of an extremum tracking feedback controller to potentially optimize ventricular recovery.

  9. The Ferris Educational Mission: A Continuing Study by the Ferris Educational Planning Committee, Part II: Continuing Education.

    Science.gov (United States)

    Ferris State Coll., Big Rapids, MI.

    This document, the second of a two-part study, focuses on the area of continuing and adult education at Ferris State College (FSC), Michigan. An overview of the status of adult and continuing education and recommendations are provided by the schools of allied health, business, general education, education, pharmacy, technical and applied arts, and…

  10. Six Years Into Its Mission, NASA's Chandra X-ray Observatory Continues to Achieve Scientific Firsts

    Science.gov (United States)

    2005-08-01

    In August 1999, NASA's Chandra X-ray Observatory opened for business. Six years later, it continues to achieve scientific firsts. "When Chandra opened its sunshade doors for the first time, it opened the possibility of studying the X-ray emission of the universe with unprecedented clarity," said Chandra project scientist Dr. Martin Weisskopf of NASA's Marshall Space Flight Center in Huntsville, Ala. "Already surpassing its goal of a five-year life, Chandra continues to rewrite textbooks with discoveries about our own solar system and images of celestial objects as far as billions of light years away." Based on the observatory's outstanding results, NASA Headquarters in Washington decided in 2001 to extend Chandra s mission from five years to ten. During the observatory s sixth year of operation, auroras from Jupiter, X-rays from Saturn, and the early days of our solar system were the focus of Chandra discoveries close to home -- discoveries with the potential to better understand the dynamics of life on Earth. Jupiter's auroras are the most spectacular and active auroras in the solar system. Extended Chandra observations revealed that Jupiter s auroral X-rays are caused by highly charged particles crashing into the atmosphere above Jupiter's poles. These results gave scientists information needed to compare Jupiter's auroras with those from Earth, and determine if they are triggered by different cosmic and planetary events. Mysterious X-rays from Saturn also received attention, as Chandra completed the first observation of a solar X-ray flare reflected from Saturn's low-latitudes, the region that correlates to Earth's equator and tropics. This observation led scientists to conclude the ringed planet may act as a mirror, reflecting explosive activity from the sun. Solar-storm watchers on Earth might see a surprising benefit. The results imply scientists could use giant planets like Saturn as remote-sensing tools to help monitor X-ray flaring on portions of the sun

  11. Phased mission modelling of systems with maintenance-free operating periods using simulated Petri nets

    Energy Technology Data Exchange (ETDEWEB)

    Chew, S.P.; Dunnett, S.J. [Department of Aeronautical and Automotive Engineering, Loughborough University, Loughborough, Leics (United Kingdom); Andrews, J.D. [Department of Aeronautical and Automotive Engineering, Loughborough University, Loughborough, Leics (United Kingdom)], E-mail: j.d.andrews@lboro.ac.uk

    2008-07-15

    A common scenario in engineering is that of a system which operates throughout several sequential and distinct periods of time, during which the modes and consequences of failure differ from one another. This type of operation is known as a phased mission, and for the mission to be a success the system must successfully operate throughout all of the phases. Examples include a rocket launch and an aeroplane flight. Component or sub-system failures may occur at any time during the mission, yet not affect the system performance until the phase in which their condition is critical. This may mean that the transition from one phase to the next is a critical event that leads to phase and mission failure, with the root cause being a component failure in a previous phase. A series of phased missions with no maintenance may be considered as a maintenance-free operating period (MFOP). This paper describes the use of a Petri net (PN) to model the reliability of the MFOP and phased missions scenario. The model uses Monte-Carlo simulation to obtain its results, and due to the modelling power of PNs, can consider complexities such as component failure rate interdependencies and mission abandonment. The model operates three different types of PN which interact to provide the overall system reliability modelling. The model is demonstrated and validated by considering two simple examples that can be solved analytically.

  12. Phased mission modelling of systems with maintenance-free operating periods using simulated Petri nets

    International Nuclear Information System (INIS)

    Chew, S.P.; Dunnett, S.J.; Andrews, J.D.

    2008-01-01

    A common scenario in engineering is that of a system which operates throughout several sequential and distinct periods of time, during which the modes and consequences of failure differ from one another. This type of operation is known as a phased mission, and for the mission to be a success the system must successfully operate throughout all of the phases. Examples include a rocket launch and an aeroplane flight. Component or sub-system failures may occur at any time during the mission, yet not affect the system performance until the phase in which their condition is critical. This may mean that the transition from one phase to the next is a critical event that leads to phase and mission failure, with the root cause being a component failure in a previous phase. A series of phased missions with no maintenance may be considered as a maintenance-free operating period (MFOP). This paper describes the use of a Petri net (PN) to model the reliability of the MFOP and phased missions scenario. The model uses Monte-Carlo simulation to obtain its results, and due to the modelling power of PNs, can consider complexities such as component failure rate interdependencies and mission abandonment. The model operates three different types of PN which interact to provide the overall system reliability modelling. The model is demonstrated and validated by considering two simple examples that can be solved analytically

  13. MCB. A continuous energy Monte Carlo burnup simulation code

    International Nuclear Information System (INIS)

    Cetnar, J.; Wallenius, J.; Gudowski, W.

    1999-01-01

    A code for integrated simulation of neutrinos and burnup based upon continuous energy Monte Carlo techniques and transmutation trajectory analysis has been developed. Being especially well suited for studies of nuclear waste transmutation systems, the code is an extension of the well validated MCNP transport program of Los Alamos National Laboratory. Among the advantages of the code (named MCB) is a fully integrated data treatment combined with a time-stepping routine that automatically corrects for burnup dependent changes in reaction rates, neutron multiplication, material composition and self-shielding. Fission product yields are treated as continuous functions of incident neutron energy, using a non-equilibrium thermodynamical model of the fission process. In the present paper a brief description of the code and applied methods are given. (author)

  14. Stochastic simulation of grain growth during continuous casting

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, A. [Department of Aerounatical Engineering, S.E.P.I., E.S.I.M.E., IPN, Instituto Politecnico Nacional (Unidad Profesional Ticoman), Av. Ticoman 600, Col. Ticoman, C.P.07340 (Mexico)]. E-mail: adalop123@mailbanamex.com; Carrillo, F. [Department of Processing Materials, CICATA-IPN Unidad Altamira Tamps (Mexico); Gonzalez, J.L. [Department of Metallurgy and Materials Engineering, E.S.I.Q.I.E.-IPN (Mexico); Lopez, S. [Department of Molecular Engineering of I.M.P., AP 14-805 (Mexico)

    2006-04-15

    The evolution of microstructure is a very important topic in material science engineering because the solidification conditions of steel billets during continuous casting process affect directly the properties of the final products. In this paper a mathematical model is described in order to simulate the dendritic growth using data of real casting operations; here a combination of deterministic and stochastic methods was used as a function of the solidification time of every node in order to create a reconstruction about the morphology of cast structures.

  15. Stochastic simulation of grain growth during continuous casting

    International Nuclear Information System (INIS)

    Ramirez, A.; Carrillo, F.; Gonzalez, J.L.; Lopez, S.

    2006-01-01

    The evolution of microstructure is a very important topic in material science engineering because the solidification conditions of steel billets during continuous casting process affect directly the properties of the final products. In this paper a mathematical model is described in order to simulate the dendritic growth using data of real casting operations; here a combination of deterministic and stochastic methods was used as a function of the solidification time of every node in order to create a reconstruction about the morphology of cast structures

  16. DYSIM - a modular simulation system for continuous dynamic processes

    International Nuclear Information System (INIS)

    la Cour Christensen, P.; Kofoed, J.E.; Larsen, N.

    1986-09-01

    The report describes a revised version of a simulation system for continuous processes, DYSIM. In relation to the previous version, which was developed in 1981, the main changes are conversion to Fortran 77 and introduction of modular structure. The latter feature gives the user a possibility for decomposing the model in modules corresponding to well delimited ph ysical units, a feature which gives a better survey of the model. Furthermore, two new integration routines are included in addition to the single one used before. (auth.)

  17. A causal reasoning for the simulation of continuous industrial processes

    International Nuclear Information System (INIS)

    Leyval, L.

    1991-01-01

    This report describes an on-line simulation tool to be integrated in a supervision support system for industrial continuous processes. The aim is to provide operators with the future behaviour of the process after significant modifications have been detected on some inputs or on measurable disturbances. A nuclear waste processing plant is used to illustrate the method: the process is modeled by a causal graph, whose nodes are the variables relevant for the operators, and the arcs the cause-effect relationships between them. Each of the arcs support a qualitative transfer function (QTF), parameterized by a delay, a static gain and a settling time. This model is the knowledge base used by the simulator. The evolution of a variable is represented by a piecewise linear function. The simulation algorithm aims to propagate the evolutions from a variable into another one in the graph thanks to the QTFs. It leads to the concept of event, a basic function constituted with a step and a ramp. 38 fig., 6 ref

  18. Constellations of Next Generation Gravity Missions: Simulations regarding optimal orbits and mitigation of aliasing errors

    Science.gov (United States)

    Hauk, M.; Pail, R.; Gruber, T.; Purkhauser, A.

    2017-12-01

    The CHAMP and GRACE missions have demonstrated the tremendous potential for observing mass changes in the Earth system from space. In order to fulfil future user needs a monitoring of mass distribution and mass transport with higher spatial and temporal resolution is required. This can be achieved by a Bender-type Next Generation Gravity Mission (NGGM) consisting of a constellation of satellite pairs flying in (near-)polar and inclined orbits, respectively. For these satellite pairs the observation concept of the GRACE Follow-on mission with a laser-based low-low satellite-to-satellite tracking (ll-SST) system and more precise accelerometers and state-of-the-art star trackers is adopted. By choosing optimal orbit constellations for these satellite pairs high frequency mass variations will be observable and temporal aliasing errors from under-sampling will not be the limiting factor anymore. As part of the European Space Agency (ESA) study "ADDCON" (ADDitional CONstellation and Scientific Analysis Studies of the Next Generation Gravity Mission) a variety of mission design parameters for such constellations are investigated by full numerical simulations. These simulations aim at investigating the impact of several orbit design choices and at the mitigation of aliasing errors in the gravity field retrieval by co-parametrization for various constellations of Bender-type NGGMs. Choices for orbit design parameters such as altitude profiles during mission lifetime, length of retrieval period, value of sub-cycles and choice of prograde versus retrograde orbits are investigated as well. Results of these simulations are presented and optimal constellations for NGGM's are identified. Finally, a short outlook towards new geophysical applications like a near real time service for hydrology is given.

  19. 20 K continuous cycle sorption coolers for the Planck flight mission

    Science.gov (United States)

    Bhandari, P.; Prina, M.; Bowman, R. C., Jr.; Paine, C.; Pearson, D.; Nash, A.

    2003-01-01

    In this paper we present the level of maturity of the hydrogen sorption cooler technology at JPL by describing the design and how it has been validated at the subsystem and system levels. In addition, we will describe how such systems could be advantageously used for other space missions with similar needs and cooler attributes.

  20. Behavioral and biological effects of autonomous versus scheduled mission management in simulated space-dwelling groups

    Science.gov (United States)

    Roma, Peter G.; Hursh, Steven R.; Hienz, Robert D.; Emurian, Henry H.; Gasior, Eric D.; Brinson, Zabecca S.; Brady, Joseph V.

    2011-05-01

    Logistical constraints during long-duration space expeditions will limit the ability of Earth-based mission control personnel to manage their astronaut crews and will thus increase the prevalence of autonomous operations. Despite this inevitability, little research exists regarding crew performance and psychosocial adaptation under such autonomous conditions. To this end, a newly-initiated study on crew management systems was conducted to assess crew performance effectiveness under rigid schedule-based management of crew activities by Mission Control versus more flexible, autonomous management of activities by the crews themselves. Nine volunteers formed three long-term crews and were extensively trained in a simulated planetary geological exploration task over the course of several months. Each crew then embarked on two separate 3-4 h missions in a counterbalanced sequence: Scheduled, in which the crews were directed by Mission Control according to a strict topographic and temporal region-searching sequence, and Autonomous, in which the well-trained crews received equivalent baseline support from Mission Control but were free to explore the planetary surface as they saw fit. Under the autonomous missions, performance in all three crews improved (more high-valued geologic samples were retrieved), subjective self-reports of negative emotional states decreased, unstructured debriefing logs contained fewer references to negative emotions and greater use of socially-referent language, and salivary cortisol output across the missions was attenuated. The present study provides evidence that crew autonomy may improve performance and help sustain if not enhance psychosocial adaptation and biobehavioral health. These controlled experimental data contribute to an emerging empirical database on crew autonomy which the international astronautics community may build upon for future research and ultimately draw upon when designing and managing missions.

  1. Multiagent Modeling and Simulation in Human-Robot Mission Operations Work System Design

    Science.gov (United States)

    Sierhuis, Maarten; Clancey, William J.; Sims, Michael H.; Shafto, Michael (Technical Monitor)

    2001-01-01

    This paper describes a collaborative multiagent modeling and simulation approach for designing work systems. The Brahms environment is used to model mission operations for a semi-autonomous robot mission to the Moon at the work practice level. It shows the impact of human-decision making on the activities and energy consumption of a robot. A collaborative work systems design methodology is described that allows informal models, created with users and stakeholders, to be used as input to the development of formal computational models.

  2. Grant Proposal for the Continuation of the Voyager Interstellar Mission: LECP Investigation

    Science.gov (United States)

    Krimigis, Stamatios M.; Armstrong, Thomas P.; Lanzerotti, Louis J.; Ip, Wing-H.; Decker, Robert B.; Keath, Edwin P.; Mauk, Barry H.; McNutt, Ralph L., Jr.; Gloeckler, George; Hamilton, Douglas C.

    1996-01-01

    This proposal documents the plans of the Low Energy Charged Particle (LECP) investigation team for participation in NASA's Voyager Interstellar Mission (VIM) as the Voyager 1 and 2 spacecraft explore the outer reaches of the heliosphere and search for the termination shock and the heliopause. The proposal covers the four year period from 1 January 1997 to 31 December 2000. The LECP instruments on Voyager 1 and 2 measure in situ intensities of charged particles with energies from about 30 keV to 100 MeV for ions, and about 20 keV to greater than 10 MeV for electrons. The instruments provide detailed spectral, angular, and compositional information about the particles. Composition is available for greater than 200 keV/nuc using multi-parameter measurements. Angular information is obtained by a mechanically scanned platform that rotates at various commanded rates. Measurements of low energy ion and electron intensities versus time and spatial location within the heliosphere contain an abundance of information regarding various transport and acceleration processes on both local (approx. 1 hr, approx. 0.01 AU) and global (approx. 11 yrs, approx. 100 AU) scales. The LECP instruments provide unique observations of such dynamical processes, and we anticipate that it will return critical information regarding the boundaries of the heliosphere. Several recent and exciting discoveries based on LECP measurements emphasize the important role that low energy charged particle distributions play in physical processes in the interplanetary medium. Yet, at the same time, these discoveries also underscore the fact that our understanding of processes in the outer heliosphere is, in most cases, incomplete, and in others, only rudimentary at best. Among the discoveries referred to above are the following: (1) Shocks: Examination of greater than 30 keV ion intensities have revealed: (a) a total absence of acceleration beyond only -100-200 keV at a strong transient shock in May 1991 at 35

  3. Scalable Integrated Multi-Mission Support System Simulator Release 3.0

    Science.gov (United States)

    Kim, John; Velamuri, Sarma; Casey, Taylor; Bemann, Travis

    2012-01-01

    The Scalable Integrated Multi-mission Support System (SIMSS) is a tool that performs a variety of test activities related to spacecraft simulations and ground segment checks. SIMSS is a distributed, component-based, plug-and-play client-server system useful for performing real-time monitoring and communications testing. SIMSS runs on one or more workstations and is designed to be user-configurable or to use predefined configurations for routine operations. SIMSS consists of more than 100 modules that can be configured to create, receive, process, and/or transmit data. The SIMSS/GMSEC innovation is intended to provide missions with a low-cost solution for implementing their ground systems, as well as significantly reducing a mission s integration time and risk.

  4. Effective teamwork and communication mitigate task saturation in simulated critical care air transport team missions.

    Science.gov (United States)

    Davis, Bradley; Welch, Katherine; Walsh-Hart, Sharon; Hanseman, Dennis; Petro, Michael; Gerlach, Travis; Dorlac, Warren; Collins, Jocelyn; Pritts, Timothy

    2014-08-01

    Critical Care Air Transport Teams (CCATTs) are a critical component of the United States Air Force evacuation paradigm. This study was conducted to assess the incidence of task saturation in simulated CCATT missions and to determine if there are predictable performance domains. Sixteen CCATTs were studied over a 6-month period. Performance was scored using a tool assessing eight domains of performance. Teams were also assessed during critical events to determine the presence or absence of task saturation and its impact on patient care. Sixteen simulated missions were reviewed and 45 crisis events identified. Task saturation was present in 22/45 (49%) of crisis events. Scoring demonstrated that task saturation was associated with poor performance in teamwork (odds ratio [OR] = 1.96), communication (OR = 2.08), and mutual performance monitoring (OR = 1.9), but not maintenance of guidelines, task management, procedural skill, and equipment management. We analyzed the effect of task saturation on adverse patient outcomes during crisis events. Adverse outcomes occurred more often when teams were task saturated as compared to non-task-saturated teams (91% vs. 23%; RR 4.1, p < 0.0001). Task saturation is observed in simulated CCATT missions. Nontechnical skills correlate with task saturation. Task saturation is associated with worsening physiologic derangements in simulated patients. Reprint & Copyright © 2014 Association of Military Surgeons of the U.S.

  5. Parallel continuous simulated tempering and its applications in large-scale molecular simulations

    Energy Technology Data Exchange (ETDEWEB)

    Zang, Tianwu; Yu, Linglin; Zhang, Chong [Applied Physics Program and Department of Bioengineering, Rice University, Houston, Texas 77005 (United States); Ma, Jianpeng, E-mail: jpma@bcm.tmc.edu [Applied Physics Program and Department of Bioengineering, Rice University, Houston, Texas 77005 (United States); Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, BCM-125, Houston, Texas 77030 (United States)

    2014-07-28

    In this paper, we introduce a parallel continuous simulated tempering (PCST) method for enhanced sampling in studying large complex systems. It mainly inherits the continuous simulated tempering (CST) method in our previous studies [C. Zhang and J. Ma, J. Chem. Phys. 130, 194112 (2009); C. Zhang and J. Ma, J. Chem. Phys. 132, 244101 (2010)], while adopts the spirit of parallel tempering (PT), or replica exchange method, by employing multiple copies with different temperature distributions. Differing from conventional PT methods, despite the large stride of total temperature range, the PCST method requires very few copies of simulations, typically 2–3 copies, yet it is still capable of maintaining a high rate of exchange between neighboring copies. Furthermore, in PCST method, the size of the system does not dramatically affect the number of copy needed because the exchange rate is independent of total potential energy, thus providing an enormous advantage over conventional PT methods in studying very large systems. The sampling efficiency of PCST was tested in two-dimensional Ising model, Lennard-Jones liquid and all-atom folding simulation of a small globular protein trp-cage in explicit solvent. The results demonstrate that the PCST method significantly improves sampling efficiency compared with other methods and it is particularly effective in simulating systems with long relaxation time or correlation time. We expect the PCST method to be a good alternative to parallel tempering methods in simulating large systems such as phase transition and dynamics of macromolecules in explicit solvent.

  6. Simulating continuous renal replacement therapy: usefulness of a new simulator device.

    Science.gov (United States)

    Mencía, Santiago; López, Manuel; López-Herce, Jesús; Ferrero, Luis; Rodríguez-Núñez, Antonio

    2014-03-01

    Simulation allows the training of life-support procedures without patient risk. We analyzed the performance and usefulness of a new device that makes feasible the external control of continuous renal replacement therapy (CRRT) machines in order to realistically generate clinical conditions and problems in simulated patients. A simple mechanical device was designed according to training needs and then hand made. This device permits the control of all monitorable pressures and therefore allows simulation of a range of clinical situations and eventual complications that might occur in real patients. We tested its performance in vitro and then during 16 high-fidelity patient-simulation scenarios included in the program of pediatric CRRT courses. Student and teacher satisfaction was assessed through an anonymous survey. Quick, accurate, real-time monitor of pressure changes, concordant with the usual clinical problems to be simulated (catheter complications, filter coagulation, inadequate CRRT device settings), were easily achieved with the new device. Instructors rated the device as user friendly and well adapted to the reality being simulated. During scenarios, students were not aware of the simulator and considered that simulated clinical conditions were realistic. Our device may be very useful for training healthcare professionals in CRRT management, thus avoiding risk to patients.

  7. Simulation of the Chang'E-5 mission contribution in lunar long wavelength gravity field improvement

    Science.gov (United States)

    Yan, Jianguo; Yang, Xuan; Ping, Jinsong; Ye, Mao; Liu, Shanhong; Jin, Weitong; Li, Fei; Barriot, Jean-Pierre

    2018-06-01

    The precision of lunar gravity field estimation has improved by means of three to five orders of magnitude since the successful GRAIL lunar mission. There are still discrepancies however, in the low degree coefficients and long wavelength components of the solutions developed by two space research centers (JPL and GSFC). These discrepancies hint at the possibilities for improving the accuracy in the long wavelength part of the lunar gravity field. In the near future, China will launch the Chang'E-5 lunar mission. In this sample-return mission, there will be a chance to do KBRR measurements between an ascending module and an orbiting module. These two modules will fly around lunar at an inclination of ˜49 degrees, with an orbital height of 100 km and an inter-satellite distance of 200 km. In our research, we simulated the contribution of the KBRR tracking mode for different GRAIL orbital geometries. This analysis indicated possible deficiencies in the low degree coefficient solutions for the polar satellite-to-satellite tracking mode at various orbital heights. We also investigated the potential contributions of the KBRR to the Chang'E-5 mission goal of lunar gravity field recovery, especially in the long wavelength component. Potential improvements were assessed using various power spectrums of the lunar gravity field models. In addition, we also investigated possible improvements in solving lunar tidal Love number K2. These results may assist the implementation of the Chang'E-5 mission.

  8. Desert Rats 2011 Mission Simulation: Effects of Microgravity Operational Modes on Fields Geology Capabilities

    Science.gov (United States)

    Bleacher, Jacob E.; Hurtado, J. M., Jr.; Meyer, J. A.

    2012-01-01

    Desert Research and Technology Studies (DRATS) is a multi-year series of NASA tests that deploy planetary surface hardware and exercise mission and science operations in difficult conditions to advance human and robotic exploration capabilities. DRATS 2011 (Aug. 30-Sept. 9, 2011) tested strategies for human exploration of microgravity targets such as near-Earth asteroids (NEAs). Here we report the crew perspective on the impact of simulated microgravity operations on our capability to conduct field geology.

  9. The Value of Biomedical Simulation Environments to Future Human Space Flight Missions

    Science.gov (United States)

    Mulugeta,Lealem; Myers, Jerry G.; Lewandowski, Beth; Platts, Steven H.

    2011-01-01

    Mars and NEO missions will expose astronaut to extended durations of reduced reduced gravity, isolation and higher radiation. These new operation conditions pose health risks that are not well understood and perhaps unanticipated. Advanced computational simulation environments can beneficially augment research to predict, assess and mitigate potential hazards to astronaut health. The NASA Digital Astronaut Project (DAP), within the NASA Human Research Program, strives to achieve this goal.

  10. Constraining continuous rainfall simulations for derived design flood estimation

    Science.gov (United States)

    Woldemeskel, F. M.; Sharma, A.; Mehrotra, R.; Westra, S.

    2016-11-01

    Stochastic rainfall generation is important for a range of hydrologic and water resources applications. Stochastic rainfall can be generated using a number of models; however, preserving relevant attributes of the observed rainfall-including rainfall occurrence, variability and the magnitude of extremes-continues to be difficult. This paper develops an approach to constrain stochastically generated rainfall with an aim of preserving the intensity-durationfrequency (IFD) relationships of the observed data. Two main steps are involved. First, the generated annual maximum rainfall is corrected recursively by matching the generated intensity-frequency relationships to the target (observed) relationships. Second, the remaining (non-annual maximum) rainfall is rescaled such that the mass balance of the generated rain before and after scaling is maintained. The recursive correction is performed at selected storm durations to minimise the dependence between annual maximum values of higher and lower durations for the same year. This ensures that the resulting sequences remain true to the observed rainfall as well as represent the design extremes that may have been developed separately and are needed for compliance reasons. The method is tested on simulated 6 min rainfall series across five Australian stations with different climatic characteristics. The results suggest that the annual maximum and the IFD relationships are well reproduced after constraining the simulated rainfall. While our presentation focusses on the representation of design rainfall attributes (IFDs), the proposed approach can also be easily extended to constrain other attributes of the generated rainfall, providing an effective platform for post-processing of stochastic rainfall generators.

  11. Mission control team structure and operational lessons learned from the 2009 and 2010 NASA desert RATS simulated lunar exploration field tests

    Science.gov (United States)

    Bell, Ernest R.; Badillo, Victor; Coan, David; Johnson, Kieth; Ney, Zane; Rosenbaum, Megan; Smart, Tifanie; Stone, Jeffry; Stueber, Ronald; Welsh, Daren; Guirgis, Peggy; Looper, Chris; McDaniel, Randall

    2013-10-01

    The NASA Desert Research and Technology Studies (Desert RATS) is an annual field test of advanced concepts, prototype hardware, and potential modes of operation to be used on human planetary surface space exploration missions. For the 2009 and 2010 NASA Desert RATS field tests, various engineering concepts and operational exercises were incorporated into mission timelines with the focus of the majority of daily operations being on simulated lunar geological field operations and executed in a manner similar to current Space Shuttle and International Space Station missions. The field test for 2009 involved a two week lunar exploration simulation utilizing a two-man rover. The 2010 Desert RATS field test took this two week simulation further by incorporating a second two-man rover working in tandem with the 2009 rover, as well as including docked operations with a Pressurized Excursion Module (PEM). Personnel for the field test included the crew, a mission management team, engineering teams, a science team, and the mission operations team. The mission operations team served as the core of the Desert RATS mission control team and included certified NASA Mission Operations Directorate (MOD) flight controllers, former flight controllers, and astronaut personnel. The backgrounds of the flight controllers were in the areas of Extravehicular Activity (EVA), onboard mechanical systems and maintenance, robotics, timeline planning (OpsPlan), and spacecraft communicator (Capcom). With the simulated EVA operations, mechanized operations (the rover), and expectations of replanning, these flight control disciplines were especially well suited for the execution of the 2009 and 2010 Desert RATS field tests. The inclusion of an operations team has provided the added benefit of giving NASA mission operations flight control personnel the opportunity to begin examining operational mission control techniques, team compositions, and mission scenarios. This also gave the mission operations

  12. Operation and evaluation of the Terminal Configured Vehicle Mission Simulator in an automated terminal area metering and spacing ATC environment

    Science.gov (United States)

    Houck, J. A.

    1980-01-01

    This paper describes the work being done at the National Aeronautics and Space Administration's Langley Research Center on the development of a mission simulator for use in the Terminal Configured Vehicle Program. A brief description of the goals and objectives of the Terminal Configured Vehicle Program is presented. A more detailed description of the Mission Simulator, in its present configuration, and its components is provided. Finally, a description of the first research study conducted in the Mission Simulator is presented along with a discussion of some preliminary results from this study.

  13. Development of a multi-media crew-training program for the terminal configured vehicle mission simulator

    Science.gov (United States)

    Rhouck, J. A.; Markos, A. T.

    1980-01-01

    This paper describes the work being done at the National Aeronautics and Space Administration's (NASA) Langley Research Center on the development of a multi-media crew-training program for the Terminal Configured Vehicle (TCV) Mission Simulator. Brief descriptions of the goals and objectives of the TCV Program and of the TCV Mission Simulator are presented. A detailed description of the training program is provided along with a description of the performance of the first group of four commercial pilots to be qualified in the TCV Mission Simulator.

  14. Quasi-continuous stochastic simulation framework for flood modelling

    Science.gov (United States)

    Moustakis, Yiannis; Kossieris, Panagiotis; Tsoukalas, Ioannis; Efstratiadis, Andreas

    2017-04-01

    Typically, flood modelling in the context of everyday engineering practices is addressed through event-based deterministic tools, e.g., the well-known SCS-CN method. A major shortcoming of such approaches is the ignorance of uncertainty, which is associated with the variability of soil moisture conditions and the variability of rainfall during the storm event.In event-based modeling, the sole expression of uncertainty is the return period of the design storm, which is assumed to represent the acceptable risk of all output quantities (flood volume, peak discharge, etc.). On the other hand, the varying antecedent soil moisture conditions across the basin are represented by means of scenarios (e.g., the three AMC types by SCS),while the temporal distribution of rainfall is represented through standard deterministic patterns (e.g., the alternative blocks method). In order to address these major inconsistencies,simultaneously preserving the simplicity and parsimony of the SCS-CN method, we have developed a quasi-continuous stochastic simulation approach, comprising the following steps: (1) generation of synthetic daily rainfall time series; (2) update of potential maximum soil moisture retention, on the basis of accumulated five-day rainfall; (3) estimation of daily runoff through the SCS-CN formula, using as inputs the daily rainfall and the updated value of soil moisture retention;(4) selection of extreme events and application of the standard SCS-CN procedure for each specific event, on the basis of synthetic rainfall.This scheme requires the use of two stochastic modelling components, namely the CastaliaR model, for the generation of synthetic daily data, and the HyetosMinute model, for the disaggregation of daily rainfall to finer temporal scales. Outcomes of this approach are a large number of synthetic flood events, allowing for expressing the design variables in statistical terms and thus properly evaluating the flood risk.

  15. Continuity and Change in Family's Role in Long-Duration Space Missions

    Science.gov (United States)

    Johnson, Phyllis

    As long-duration missions become commonplace, it will be important to consider the effect of the astronaut's career on his/her family, and the role of family in supporting that career. In the short history of the space program, archival information about three long-duration programs- Skylab, Shuttle-Mir, and the International Space Station—-provides valuable information about the astronauts' adjustment to increasingly longer times in space. These sources potentially include the astronaut's views about the role of family in that adjustment. The purpose of this paper is to present a qualitative analysis of the astronauts' views about the role family played in his/her career, as well as the effect of the astronaut career on his/her family. Specifically, what roles did family play, e.g., being there at important events, accepting the importance of the astronaut career? How did astronauts view the effects of separation, risks, and publicity on their family? How much did astronauts emphasize dealing with separation through communication with family? How consistent have astronauts' views remained over the three types of missions which have spanned from 1973 to today? The data base for this qualitative study is the Johnson Space Center oral histories for astronauts who participated in Skylab or Shuttle-Mir, and the Johnson Space Center archives of ISS mission journals and logs, and pre-flight interviews with ISS astronauts. Male astronauts are the main focus of the change-over-time information as only one woman participated in Shuttle- Mir and no women were in the Skylab program. However, qualitative data will be presented about female astronauts on ISS and on Shuttle-Mir for some comparative information by sex for those programs. Skylab preliminary findings: Having a wife and parents who were supportive made all of the difference in the astronaut career. It would not have been possible to maintain some semblance of family life without the wife's managing it. Private

  16. A simulated avalanche search and rescue mission induces temporary physiological and behavioural changes in military dogs.

    Science.gov (United States)

    Diverio, Silvana; Barbato, Olimpia; Cavallina, Roberta; Guelfi, Gabriella; Iaboni, Martina; Zasso, Renato; Di Mari, Walter; Santoro, Michele Matteo; Knowles, Toby G

    2016-09-01

    Saving human lives is of paramount importance in avalanche rescue missions. Avalanche military dogs represent an invaluable resource in these operations. However, their performance can be influenced by several environmental, social and transport challenges. If too severe, these are likely to activate a range of responses to stress, which might put at risk the dogs' welfare. The aim of this study was to assess the physiological and behavioural responses of a group of military dogs to a Simulated Avalanche Search and Rescue mission (SASR). Seventeen avalanche dogs from the Italian Military Force Guardia di Finanza (SAGF dogs) were monitored during a simulated search for a buried operator in an artificial avalanche area (SASR). Heart rate (HR), body temperature (RBT) and blood samples were collected at rest the day before the trial (T0), immediately after helicopter transport at the onset of the SASR (T1), after the discovery of the buried operator (T2) and 2h later (T3). Heart rate (HR), rectal body temperature (RBT), cortisol, aspartate aminotransferase (AST), creatine kinase (CK), non-esterified fatty acids (NEFA) and lactate dehydrogenase (LDH) were measured. During the search mission the behaviour of each SAGF dog was measured by focal animal sampling and qualitatively assessed by its handler and two observers. Inter-rater agreement was evaluated. Snow and environmental variables were also measured. All dogs successfully completed their search for the buried, simulated victim within 10min. The SASR was shown to exert significant increases on RBT, NEFA and cortisol (Pdog's search mission ability was found only for motivation, signalling behaviour, signs of stress and possessive reward playing. More time signalling was related to shorter search time. In conclusion, despite extreme environmental and training conditions only temporary physiological and behavioural changes were recorded in the avalanche dogs. Their excellent performance in successful simulated SASR

  17. A High Fidelity Approach to Data Simulation for Space Situational Awareness Missions

    Science.gov (United States)

    Hagerty, S.; Ellis, H., Jr.

    2016-09-01

    Space Situational Awareness (SSA) is vital to maintaining our Space Superiority. A high fidelity, time-based simulation tool, PROXOR™ (Proximity Operations and Rendering), supports SSA by generating realistic mission scenarios including sensor frame data with corresponding truth. This is a unique and critical tool for supporting mission architecture studies, new capability (algorithm) development, current/future capability performance analysis, and mission performance prediction. PROXOR™ provides a flexible architecture for sensor and resident space object (RSO) orbital motion and attitude control that simulates SSA, rendezvous and proximity operations scenarios. The major elements of interest are based on the ability to accurately simulate all aspects of the RSO model, viewing geometry, imaging optics, sensor detector, and environmental conditions. These capabilities enhance the realism of mission scenario models and generated mission image data. As an input, PROXOR™ uses a library of 3-D satellite models containing 10+ satellites, including low-earth orbit (e.g., DMSP) and geostationary (e.g., Intelsat) spacecraft, where the spacecraft surface properties are those of actual materials and include Phong and Maxwell-Beard bidirectional reflectance distribution function (BRDF) coefficients for accurate radiometric modeling. We calculate the inertial attitude, the changing solar and Earth illumination angles of the satellite, and the viewing angles from the sensor as we propagate the RSO in its orbit. The synthetic satellite image is rendered at high resolution and aggregated to the focal plane resolution resulting in accurate radiometry even when the RSO is a point source. The sensor model includes optical effects from the imaging system [point spread function (PSF) includes aberrations, obscurations, support structures, defocus], detector effects (CCD blooming, left/right bias, fixed pattern noise, image persistence, shot noise, read noise, and quantization

  18. Mission possible: Building an effective business continuity team in seven steps.

    Science.gov (United States)

    Porter, David

    2016-01-01

    Several books and studies exist on the creation, development and benefits of high-performing teams; many others offer insights into the business continuity management (BCM) discipline, crisis response and planning. Very rarely, however, do they cover both. This paper will explore the seven main development areas that helped build the foundation for a successful and high-performing BCM team in the Australian Taxation Office. Practical, actionable advice will be provided, recognising that the task for those starting out can be quite daunting and complex.

  19. Use of Web 2.0 Technologies for Public Outreach on a Simulated Mars Mission

    Science.gov (United States)

    Shiro, B.; Palaia, J.; Ferrone, K.

    2009-12-01

    Recent advances in social media and internet communications have revolutionized the ways people interact and disseminate information. Astronauts are already starting to take advantage of these tools by blogging and tweeting from space, and almost all NASA missions now have presences on the major social networking sites. One priority for future human explorers on Mars will be communicating their experiences to the people back on Earth. During July 2009, a six-member crew of volunteers carried out a simulated Mars mission at the Flashline Mars Arctic Research Station (FMARS) on Devon Island in the Canadian Arctic. Living in a habitat, conducting EVAs wearing spacesuits, and observing communication delays with “Earth,” the crew endured restrictions similar to those that will be faced by future human Mars explorers. Throughout the expedition, crewmembers posted regular blog entries, reports, photos, videos, and updates to their website and social media outlets Twitter, Facebook, YouTube, and Picasa Web Albums. During the sixteen EVAs of their field science research campaign, FMARS crewmembers collected GPS track information and took geotagged photos using GPS-enabled cameras. They combined their traverse GPS tracks with photo location information into KML/KMZ files that website visitors can view in Google Maps or Google Earth. Although the crew observed a strict 20-minute communication delay with “Earth” to simulate a real Mars mission, they broke this rule to conduct four very successful live webcasts with student groups using Skype since education and public outreach were important objectives of the endeavor. This presentation will highlight the use of Web 2.0 technologies for public outreach during the simulated Mars expedition and the implications for other remote scientific journeys. The author embarks on a "rover" to carry out an EVA near the FMARS Habitat. The satellite dish to the right of the structure was used for all communications with the remote

  20. Development of industry processes simulators. Part III (Continuous casting)

    International Nuclear Information System (INIS)

    Ramirez, A.; Morales, R.; Morales, A. J.; Ramos, A.; Solorio, G.

    2006-01-01

    This work written for illustrating the use of Monte Carlo methods and generating of random number in combination with the information of the simulation system of thermal behaviour described previously in order to reproduce in a computer the solidification process of the steel and simulate the formation of strictures of casting step by step. (Author). 12 refs

  1. Production of continuous glass fiber using lunar simulant

    Science.gov (United States)

    Tucker, Dennis S.; Ethridge, Edwin C.; Curreri, Peter A.

    1991-01-01

    The processing parameters and mechanical properties of glass fibers pulled from simulated lunar basalt are tested. The simulant was prepared using a plasma technique. The composition is representative of a low titanium mare basalt (Apollo sample 10084). Lunar gravity experiments are to be performed utilizing parabolic aircraft free-fall maneuvers which yield 30 seconds of 1/6-g per maneuver.

  2. Multiplatform Mission Planning and Operations Simulation Environment for Adaptive Remote Sensors

    Science.gov (United States)

    Smith, G.; Ball, C.; O'Brien, A.; Johnson, J. T.

    2017-12-01

    We report on the design and development of mission simulator libraries to support the emerging field of adaptive remote sensors. We will outline the current state of the art in adaptive sensing, provide analysis of how the current approach to performing observing system simulation experiments (OSSEs) must be changed to enable adaptive sensors for remote sensing, and present an architecture to enable their inclusion in future OSSEs.The growing potential of sensors capable of real-time adaptation of their operational parameters calls for a new class of mission planning and simulation tools. Existing simulation tools used in OSSEs assume a fixed set of sensor parameters in terms of observation geometry, frequencies used, resolution, or observation time, which allows simplifications to be made in the simulation and allows sensor observation errors to be characterized a priori. Adaptive sensors may vary these parameters depending on the details of the scene observed, so that sensor performance is not simple to model without conducting OSSE simulations that include sensor adaptation in response to varying observational environment. Adaptive sensors are of significance to resource-constrained, small satellite platforms because they enable the management of power and data volumes while providing methods for multiple sensors to collaborate.The new class of OSSEs required to utilize adaptive sensors located on multiple platforms must answer the question: If the physical act of sensing has a cost, how does the system determine if the science value of a measurement is worth the cost and how should that cost be shared among the collaborating sensors?Here we propose to answer this question using an architecture structured around three modules: ADAPT, MANAGE and COLLABORATE. The ADAPT module is a set of routines to facilitate modeling of adaptive sensors, the MANAGE module will implement a set of routines to facilitate simulations of sensor resource management when power and data

  3. The Value of Biomedical Simulation Environments to Future Human Space Flight Missions

    Science.gov (United States)

    Mulugeta, Lealem; Myers, Jerry G.; Skytland, Nicholas G.; Platts, Steven H.

    2010-01-01

    With the ambitious goals to send manned missions to asteroids and onto Mars, substantial work will be required to ensure the well being of the men and women who will undertake these difficult missions. Unlike current International Space Station or Shuttle missions, astronauts will be required to endure long-term exposure to higher levels of radiation, isolation and reduced gravity. These new operation conditions will pose health risks that are currently not well understood and perhaps unanticipated. Therefore, it is essential to develop and apply advanced tools to predict, assess and mitigate potential hazards to astronaut health. NASA s Digital Astronaut Project (DAP) is working to develop and apply computational models of physiologic response to space flight operation conditions over various time periods and environmental circumstances. The collective application and integration of well vetted models assessing the physiology, biomechanics and anatomy is referred to as the Digital Astronaut. The Digital Astronaut simulation environment will serve as a practical working tool for use by NASA in operational activities such as the prediction of biomedical risks and functional capabilities of astronauts. In additional to space flight operation conditions, DAP s work has direct applicability to terrestrial biomedical research by providing virtual environments for hypothesis testing, experiment design, and to reduce animal/human testing. A practical application of the DA to assess pre and post flight responses to exercise is illustrated and the difficulty in matching true physiological responses is discussed.

  4. Simulation of continuous variable quantum games without entanglement

    Science.gov (United States)

    Li, Shang-Bin

    2011-07-01

    A simulation scheme of quantum version of Cournot's duopoly is proposed, in which there is a new Nash equilibrium that may also be Pareto optimal without any entanglement involved. The unique property of this simulation scheme is decoherence-free against the symmetric photon loss. Furthermore, we analyze the effects of the asymmetric information on this simulation scheme and investigate the case of asymmetric game caused by asymmetric photon loss. A second-order phase transition-like behavior of the average profits of firms 1 and 2 in a Nash equilibrium can be observed with the change of the degree of asymmetry of the information or the degree of 'virtual cooperation'. It is also found that asymmetric photon loss in this simulation scheme plays a similar role as that with the asymmetric entangled states in the quantum game.

  5. Simulation of continuous variable quantum games without entanglement

    International Nuclear Information System (INIS)

    Li Shangbin

    2011-01-01

    A simulation scheme of quantum version of Cournot's duopoly is proposed, in which there is a new Nash equilibrium that may also be Pareto optimal without any entanglement involved. The unique property of this simulation scheme is decoherence-free against the symmetric photon loss. Furthermore, we analyze the effects of the asymmetric information on this simulation scheme and investigate the case of asymmetric game caused by asymmetric photon loss. A second-order phase transition-like behavior of the average profits of firms 1 and 2 in a Nash equilibrium can be observed with the change of the degree of asymmetry of the information or the degree of 'virtual cooperation'. It is also found that asymmetric photon loss in this simulation scheme plays a similar role as that with the asymmetric entangled states in the quantum game.

  6. Simulation of continuous variable quantum games without entanglement

    Energy Technology Data Exchange (ETDEWEB)

    Li Shangbin, E-mail: stephenli74@yahoo.com.cn [Research and Development Department of Amertron Optoelectronic (Kunshan) Ltd, Jingde Road 28, Kunshan, Suzhou (China)

    2011-07-22

    A simulation scheme of quantum version of Cournot's duopoly is proposed, in which there is a new Nash equilibrium that may also be Pareto optimal without any entanglement involved. The unique property of this simulation scheme is decoherence-free against the symmetric photon loss. Furthermore, we analyze the effects of the asymmetric information on this simulation scheme and investigate the case of asymmetric game caused by asymmetric photon loss. A second-order phase transition-like behavior of the average profits of firms 1 and 2 in a Nash equilibrium can be observed with the change of the degree of asymmetry of the information or the degree of 'virtual cooperation'. It is also found that asymmetric photon loss in this simulation scheme plays a similar role as that with the asymmetric entangled states in the quantum game.

  7. The Continued Need for Modeling and Scaled Testing to Advance the Hanford Tank Waste Mission

    Energy Technology Data Exchange (ETDEWEB)

    Peurrung, Loni M.; Fort, James A.; Rector, David R.

    2013-09-03

    Hanford tank wastes are chemically complex slurries of liquids and solids that can exhibit changes in rheological behavior during retrieval and processing. The Hanford Waste Treatment and Immobilization Plant (WTP) recently abandoned its planned approach to use computational fluid dynamics (CFD) supported by testing at less than full scale to verify the design of vessels that process these wastes within the plant. The commercial CFD tool selected was deemed too difficult to validate to the degree necessary for use in the design of a nuclear facility. Alternative, but somewhat immature, CFD tools are available that can simulate multiphase flow of non-Newtonian fluids. Yet both CFD and scaled testing can play an important role in advancing the Hanford tank waste mission—in supporting the new verification approach, which is to conduct testing in actual plant vessels; in supporting waste feed delivery, where scaled testing is ongoing; as a fallback approach to design verification if the Full Scale Vessel Testing Program is deemed too costly and time-consuming; to troubleshoot problems during commissioning and operation of the plant; and to evaluate the effects of any proposed changes in operating conditions in the future to optimize plant performance.

  8. Observing System Simulation Experiment (OSSE) for the HyspIRI Spectrometer Mission

    Science.gov (United States)

    Turmon, Michael J.; Block, Gary L.; Green, Robert O.; Hua, Hook; Jacob, Joseph C.; Sobel, Harold R.; Springer, Paul L.; Zhang, Qingyuan

    2010-01-01

    The OSSE software provides an integrated end-to-end environment to simulate an Earth observing system by iteratively running a distributed modeling workflow based on the HyspIRI Mission, including atmospheric radiative transfer, surface albedo effects, detection, and retrieval for agile exploration of the mission design space. The software enables an Observing System Simulation Experiment (OSSE) and can be used for design trade space exploration of science return for proposed instruments by modeling the whole ground truth, sensing, and retrieval chain and to assess retrieval accuracy for a particular instrument and algorithm design. The OSSE in fra struc ture is extensible to future National Research Council (NRC) Decadal Survey concept missions where integrated modeling can improve the fidelity of coupled science and engineering analyses for systematic analysis and science return studies. This software has a distributed architecture that gives it a distinct advantage over other similar efforts. The workflow modeling components are typically legacy computer programs implemented in a variety of programming languages, including MATLAB, Excel, and FORTRAN. Integration of these diverse components is difficult and time-consuming. In order to hide this complexity, each modeling component is wrapped as a Web Service, and each component is able to pass analysis parameterizations, such as reflectance or radiance spectra, on to the next component downstream in the service workflow chain. In this way, the interface to each modeling component becomes uniform and the entire end-to-end workflow can be run using any existing or custom workflow processing engine. The architecture lets users extend workflows as new modeling components become available, chain together the components using any existing or custom workflow processing engine, and distribute them across any Internet-accessible Web Service endpoints. The workflow components can be hosted on any Internet-accessible machine

  9. A simulation based optimization approach to model and design life support systems for manned space missions

    Science.gov (United States)

    Aydogan, Selen

    This dissertation considers the problem of process synthesis and design of life-support systems for manned space missions. A life-support system is a set of technologies to support human life for short and long-term spaceflights, via providing the basic life-support elements, such as oxygen, potable water, and food. The design of the system needs to meet the crewmember demand for the basic life-support elements (products of the system) and it must process the loads generated by the crewmembers. The system is subject to a myriad of uncertainties because most of the technologies involved are still under development. The result is high levels of uncertainties in the estimates of the model parameters, such as recovery rates or process efficiencies. Moreover, due to the high recycle rates within the system, the uncertainties are amplified and propagated within the system, resulting in a complex problem. In this dissertation, two algorithms have been successfully developed to help making design decisions for life-support systems. The algorithms utilize a simulation-based optimization approach that combines a stochastic discrete-event simulation and a deterministic mathematical programming approach to generate multiple, unique realizations of the controlled evolution of the system. The timelines are analyzed using time series data mining techniques and statistical tools to determine the necessary technologies, their deployment schedules and capacities, and the necessary basic life-support element amounts to support crew life and activities for the mission duration.

  10. Incidence, Etiology and Risk Factors for Travelers' Diarrhea during a Hospital Ship-Based Military Humanitarian Mission: Continuing Promise 2011.

    Directory of Open Access Journals (Sweden)

    Jessica M Hameed

    Full Text Available Travelers' diarrhea (TD is the most common ailment affecting travelers, including deployed U.S. military. Continuing Promise 2011 was a 5-month humanitarian assistance/disaster response (HA/DR military and non-governmental organization training mission aboard the hospital ship USNS Comfort, which deployed to Central and South America and the Caribbean between April and September 2011. Enhanced TD surveillance was undertaken during this mission for public health purposes. Passive surveillance (clinic visits, active surveillance (self-reported questionnaires, and stool samples were collected weekly from shipboard personnel. Descriptive statistics and multivariate-logistic regression methods were used to estimate disease burden and risk factor identification. Two polymerase chain reaction methods on frozen stool were used for microbiological identification. TD was the primary complaint for all clinic visits (20% and the leading cause of lost duties days due to bed rest confinement (62%, though underreported, as the active self-reported incidence was 3.5 times higher than the passive clinic-reported incidence. Vomiting (p = 0.002, feeling lightheaded or weak (p = 0.005, and being a food handler (p = 0.017 were associated with increased odds of lost duty days. Thirty-eight percent of self-reported cases reported some amount of performance impact. Based on the epidemiological curve, country of exercise and liberty appeared to be temporally associated with increased risk. From the weekly self-reported questionnaire risk factor analysis, eating off ship in the prior week was strongly associated (adjusted odds ratio [OR] 2.4, p<0.001. Consumption of seafood increased risk (aOR 1.7, p = 0.03, though consumption of ice appeared protective (aOR 0.3, p = 0.01. Etiology was bacterial (48%, with enterotoxigenic Escherichia coli as the predominant pathogen (35%. Norovirus was identified as a sole pathogen in 12%, though found as a copathogen in an additional 6

  11. Monte Carlo simulation of continuous-space crystal growth

    International Nuclear Information System (INIS)

    Dodson, B.W.; Taylor, P.A.

    1986-01-01

    We describe a method, based on Monte Carlo techniques, of simulating the atomic growth of crystals without the discrete lattice space assumed by conventional Monte Carlo growth simulations. Since no lattice space is assumed, problems involving epitaxial growth, heteroepitaxy, phonon-driven mechanisms, surface reconstruction, and many other phenomena incompatible with the lattice-space approximation can be studied. Also, use of the Monte Carlo method circumvents to some extent the extreme limitations on simulated timescale inherent in crystal-growth techniques which might be proposed using molecular dynamics. The implementation of the new method is illustrated by studying the growth of strained-layer superlattice (SLS) interfaces in two-dimensional Lennard-Jones atomic systems. Despite the extreme simplicity of such systems, the qualitative features of SLS growth seen here are similar to those observed experimentally in real semiconductor systems

  12. Numerical simulation of nonlinear continuity equations by evolving diffeomorphisms

    KAUST Repository

    Carrillo, José A.

    2016-09-22

    In this paper we present a numerical scheme for nonlinear continuity equations, which is based on the gradient flow formulation of an energy functional with respect to the quadratic transportation distance. It can be applied to a large class of nonlinear continuity equations, whose dynamics are driven by internal energies, given external potentials and/or interaction energies. The solver is based on its variational formulation as a gradient flow with respect to the Wasserstein distance. Positivity of solutions as well as energy decrease of the semi-discrete scheme are guaranteed by its construction. We illustrate this property with various examples in spatial dimension one and two.

  13. An IP-Based Software System for Real-time, Closed Loop, Multi-Spacecraft Mission Simulations

    Science.gov (United States)

    Cary, Everett; Davis, George; Higinbotham, John; Burns, Richard; Hogie, Keith; Hallahan, Francis

    2003-01-01

    This viewgraph presentation provides information on the architecture of a computerized testbest for simulating Distributed Space Systems (DSS) for controlling spacecraft flying in formation. The presentation also discusses and diagrams the Distributed Synthesis Environment (DSE) for simulating and planning DSS missions.

  14. Simulation-Based Prediction of Equivalent Continuous Noises during Construction Processes.

    Science.gov (United States)

    Zhang, Hong; Pei, Yun

    2016-08-12

    Quantitative prediction of construction noise is crucial to evaluate construction plans to help make decisions to address noise levels. Considering limitations of existing methods for measuring or predicting the construction noise and particularly the equivalent continuous noise level over a period of time, this paper presents a discrete-event simulation method for predicting the construction noise in terms of equivalent continuous level. The noise-calculating models regarding synchronization, propagation and equivalent continuous level are presented. The simulation framework for modeling the noise-affected factors and calculating the equivalent continuous noise by incorporating the noise-calculating models into simulation strategy is proposed. An application study is presented to demonstrate and justify the proposed simulation method in predicting the equivalent continuous noise during construction. The study contributes to provision of a simulation methodology to quantitatively predict the equivalent continuous noise of construction by considering the relevant uncertainties, dynamics and interactions.

  15. Intra-EVA Space-to-Ground Interactions when Conducting Scientific Fieldwork Under Simulated Mars Mission Constraints

    Science.gov (United States)

    Beaton, Kara H.; Chappell, Steven P.; Abercromby, Andrew F. J.; Lim, Darlene S. S.

    2018-01-01

    The Biologic Analog Science Associated with Lava Terrains (BASALT) project is a four-year program dedicated to iteratively designing, implementing, and evaluating concepts of operations (ConOps) and supporting capabilities to enable and enhance scientific exploration for future human Mars missions. The BASALT project has incorporated three field deployments during which real (non-simulated) biological and geochemical field science have been conducted at two high-fidelity Mars analog locations under simulated Mars mission conditions, including communication delays and data transmission limitations. BASALT's primary Science objective has been to extract basaltic samples for the purpose of investigating how microbial communities and habitability correlate with the physical and geochemical characteristics of chemically altered basalt environments. Field sites include the active East Rift Zone on the Big Island of Hawai'i, reminiscent of early Mars when basaltic volcanism and interaction with water were widespread, and the dormant eastern Snake River Plain in Idaho, similar to present-day Mars where basaltic volcanism is rare and most evidence for volcano-driven hydrothermal activity is relict. BASALT's primary Science Operations objective has been to investigate exploration ConOps and capabilities that facilitate scientific return during human-robotic exploration under Mars mission constraints. Each field deployment has consisted of ten extravehicular activities (EVAs) on the volcanic flows in which crews of two extravehicular and two intravehicular crewmembers conducted the field science while communicating across time delay and under bandwidth constraints with an Earth-based Mission Support Center (MSC) comprised of expert scientists and operators. Communication latencies of 5 and 15 min one-way light time and low (0.512 Mb/s uplink, 1.54 Mb/s downlink) and high (5.0 Mb/s uplink, 10.0 Mb/s downlink) bandwidth conditions were evaluated. EVA crewmembers communicated

  16. Construction and simulation of a novel continuous traffic flow model

    International Nuclear Information System (INIS)

    Hwang, Yao-Hsin; Yu, Jui-Ling

    2017-01-01

    In this paper, we aim to propose a novel mathematical model for traffic flow and apply a newly developed characteristic particle method to solve the associate governing equations. As compared with the existing non-equilibrium higher-order traffic flow models, the present one is put forward to satisfy the following three conditions: 1.Preserve the equilibrium state in the smooth region. 2.Yield an anisotropic propagation of traffic flow information. 3.Expressed with a conservation law form for traffic momentum. These conditions will ensure a more practical simulation in traffic flow physics: The current traffic will not be influenced by the condition in the behind and result in unambiguous condition across a traffic shock. Through analyses of characteristics, stability condition and steady-state solution adherent to the equation system, it is shown that the proposed model actually conform to these conditions. Furthermore, this model can be cast into its characteristic form which, incorporated with the Rankine-Hugoniot relation, is appropriate to be simulated by the characteristic particle method to obtain accurate computational results. - Highlights: • The traffic model expressed with the momentum conservation law. • Traffic flow information propagate anisotropically and preserve the equilibrium state in the smooth region. • Computational particles of two families are invented to mimic forward-running and backward-running characteristics. • Formation of shocks will be naturally detected by the intersection of computational particles of same family. • A newly developed characteristic particle method is used to simulate traffic flow model equations.

  17. Simulation and optimization of continuous extractive fermentation with recycle system

    Science.gov (United States)

    Widjaja, Tri; Altway, Ali; Rofiqah, Umi; Airlangga, Bramantyo

    2017-05-01

    Extractive fermentation is continuous fermentation method which is believed to be able to substitute conventional fermentation method (batch). The recovery system and ethanol refinery will be easier. Continuous process of fermentation will make the productivity increase although the unconverted sugar in continuous fermentation is still in high concentration. In order to make this process more efficient, the recycle process was used. Increasing recycle flow will enhance the probability of sugar to be re-fermented. However, this will make ethanol enter fermentation column. As a result, the accumulated ethanol will inhibit the growth of microorganism. This research aims to find optimum conditions of solvent to broth ratio (S:B) and recycle flow to fresh feed ratio in order to produce the best yield and productivity. This study employed optimization by Hooke Jeeves method using Matlab 7.8 software. The result indicated that optimum condition occured in S: B=2.615 and R: F=1.495 with yield = 50.2439 %.

  18. CH4 IPDA Lidar mission data simulator and processor for MERLIN: prototype development at LMD/CNRS/Ecole Polytechnique

    Science.gov (United States)

    Olivier, Chomette; Armante, Raymond; Crevoisier, Cyril; Delahaye, Thibault; Edouart, Dimitri; Gibert, Fabien; Nahan, Frédéric; Tellier, Yoann

    2018-04-01

    The MEthane Remote sensing Lidar missioN (MERLIN), currently in phase C, is a joint cooperation between France and Germany on the development of a spatial Integrated Path Differential Absorption (IPDA) LIDAR (LIght Detecting And Ranging) to conduct global observations of atmospheric methane. This presentation will focus on the status of a LIDAR mission data simulator and processor developed at LMD (Laboratoire de Météorologie Dynamique), Ecole Polytechnique, France, for MERLIN to assess the performances in realistic observational situations.

  19. Use of Web 2.0 Technologies for Public Outreach on a Simulated Mars Mission

    Science.gov (United States)

    Ferrone, Kristine; Shiro, Brian; Palaia, Joseph E., IV

    2009-01-01

    Recent advances in social media and internet communications have revolutionized the ways people interact and disseminate information. Astronauts are already taking advantage of these tools by blogging and tweeting from space, and almost all NASA missions now have presences on the major social networking sites. One priotity for future human explorers on Mars will be communicating their experiences to the people back on Earth. During July 2009, a 6-member crew of volunteers carried out a simulated Mars mission at the Flashline Mars Arctic Research Station (FMARS). The Mars Society built the mock Mars habitat in 2000-01 to help develop key knowledge and inspire the public for human Mars exploration. It is located on Devon island about 1600 km from the North Pole within the Arctic Circle. The structure is situated on the rim of Haughton Crater in an environment geologically and biologically analogous to Mars. Living in a habitat, conducting EVAs wearing spacesuits, and observing communication delays with "Earth,"the crew endured restrictions similar to those that will be faced by future human Mars explorers. Throughout the expedition, crewmembers posted daily blog entries, reports, photos, videos, and updates to their website and social media outlets Twitter, Facebook, YouTube, and Picasa Web Albums. During the sixteen EVAs of thier field science research campaign, FMARS crewmembers collected GPS track information and took geotagged photos using GPS-enabled cameras. They combined their traverse GPS tracks with photo location information into KML/KMZ files that website visitors can view in Google Earth.

  20. Wireless Monitoring of Changes in Crew Relations during Long-Duration Mission Simulation.

    Directory of Open Access Journals (Sweden)

    Bernd Johannes

    Full Text Available Group structure and cohesion along with their changes over time play an important role in the success of missions where crew members spend prolonged periods of time under conditions of isolation and confinement. Therefore, an objective system for unobtrusive monitoring of crew cohesion and possible individual stress reactions is of high interest. For this purpose, an experimental wireless group structure (WLGS monitoring system integrated into a mobile psychophysiological system was developed. In the presented study the WLGS module was evaluated separately in six male subjects (27-38 years old participating in a 520-day simulated mission to Mars. Two days per week, each crew member wore a small sensor that registered the presence and distance of the sensors either worn by the other subjects or strategically placed throughout the isolation facility. The registration between two sensors was on average 91.0% in accordance. A correspondence of 95.7% with the survey video on day 475 confirmed external reliability. An integrated score of the "crew relation time index" was calculated and analyzed over time. Correlation analyses of a sociometric questionnaire (r = .35-.55, p< .05 and an ethological group approach (r = .45-.66, p < 05 provided initial evidence of the method's validity as a measure of cohesion when taking behavioral and activity patterns into account (e.g. only including activity phases in the afternoon. This confirms our assumption that the registered amount of time spent together during free time is associated with the intensity of personal relationships.

  1. Simulation and Control Lab Development for Power and Energy Management for NASA Manned Deep Space Missions

    Science.gov (United States)

    McNelis, Anne M.; Beach, Raymond F.; Soeder, James F.; McNelis, Nancy B.; May, Ryan; Dever, Timothy P.; Trase, Larry

    2014-01-01

    The development of distributed hierarchical and agent-based control systems will allow for reliable autonomous energy management and power distribution for on-orbit missions. Power is one of the most critical systems on board a space vehicle, requiring quick response time when a fault or emergency is identified. As NASAs missions with human presence extend beyond low earth orbit autonomous control of vehicle power systems will be necessary and will need to reliably function for long periods of time. In the design of autonomous electrical power control systems there is a need to dynamically simulate and verify the EPS controller functionality prior to use on-orbit. This paper presents the work at NASA Glenn Research Center in Cleveland, Ohio where the development of a controls laboratory is being completed that will be utilized to demonstrate advanced prototype EPS controllers for space, aeronautical and terrestrial applications. The control laboratory hardware, software and application of an autonomous controller for demonstration with the ISS electrical power system is the subject of this paper.

  2. Space Geodetic Technique Co-location in Space: Simulation Results for the GRASP Mission

    Science.gov (United States)

    Kuzmicz-Cieslak, M.; Pavlis, E. C.

    2011-12-01

    The Global Geodetic Observing System-GGOS, places very stringent requirements in the accuracy and stability of future realizations of the International Terrestrial Reference Frame (ITRF): an origin definition at 1 mm or better at epoch and a temporal stability on the order of 0.1 mm/y, with similar numbers for the scale (0.1 ppb) and orientation components. These goals were derived from the requirements of Earth science problems that are currently the international community's highest priority. None of the geodetic positioning techniques can achieve this goal alone. This is due in part to the non-observability of certain attributes from a single technique. Another limitation is imposed from the extent and uniformity of the tracking network and the schedule of observational availability and number of suitable targets. The final limitation derives from the difficulty to "tie" the reference points of each technique at the same site, to an accuracy that will support the GGOS goals. The future GGOS network will address decisively the ground segment and to certain extent the space segment requirements. The JPL-proposed multi-technique mission GRASP (Geodetic Reference Antenna in Space) attempts to resolve the accurate tie between techniques, using their co-location in space, onboard a well-designed spacecraft equipped with GNSS receivers, a SLR retroreflector array, a VLBI beacon and a DORIS system. Using the anticipated system performance for all four techniques at the time the GGOS network is completed (ca 2020), we generated a number of simulated data sets for the development of a TRF. Our simulation studies examine the degree to which GRASP can improve the inter-technique "tie" issue compared to the classical approach, and the likely modus operandi for such a mission. The success of the examined scenarios is judged by the quality of the origin and scale definition of the resulting TRF.

  3. In-Vessel Composting of Simulated Long-Term Missions Space-Related Solid Wastes

    Science.gov (United States)

    Rodriguez-Carias, Abner A.; Sager, John; Krumins, Valdis; Strayer, Richard; Hummerick, Mary; Roberts, Michael S.

    2002-01-01

    Reduction and stabilization of solid wastes generated during space missions is a major concern for the Advanced Life Support - Resource Recovery program at the NASA, Kennedy Space Center. Solid wastes provide substrates for pathogen proliferation, produce strong odor, and increase storage requirements during space missions. A five periods experiment was conducted to evaluate the Space Operation Bioconverter (SOB), an in vessel composting system, as a biological processing technology to reduce and stabilize simulated long-term missions space related solid-wastes (SRSW). For all periods, SRSW were sorted into components with fast (FBD) and slow (SBD) biodegradability. Uneaten food and plastic were used as a major FBD and SBD components, respectively. Compost temperature (C), CO2 production (%), mass reduction (%), and final pH were utilized as criteria to determine compost quality. In period 1, SOB was loaded with a 55% FBD: 45% SBD mixture and was allowed to compost for 7 days. An eleven day second composting period was conducted loading the SOB with 45% pre-composted SRSW and 55% FBD. Period 3 and 4 evaluated the use of styrofoam as a bulking agent and the substitution of regular by degradable plastic on the composting characteristics of SRSW, respectively. The use of ceramic as a bulking agent and the relationship between initial FBD mass and heat production was investigated in period 5. Composting SRSW resulted in an acidic fermentation with a minor increase in compost temperature, low CO2 production, and slightly mass reduction. Addition of styrofoam as a bulking agent and substitution of regular by biodegradable plastic improved the composting characteristics of SRSW, as evidenced by higher pH, CO2 production, compost temperature and mass reduction. Ceramic as a bulking agent and increase the initial FBD mass (4.4 kg) did not improve the composting process. In summary, the SOB is a potential biological technology for reduction and stabilization of mission space

  4. Mercury Conditions for the MESSENGER Mission Simulated in High- Solar-Radiation Vacuum Tests

    Science.gov (United States)

    Wong, Wayne A.

    2003-01-01

    The MESSENGER (Mercury Surface, Space Environment, Geochemistry, and Ranging) spacecraft, planned for launch in March 2004, will perform two flybys of Mercury before entering a year-long orbit of the planet in September 2009. The mission will provide opportunities for detailed characterization of the surface, interior, atmosphere, and magnetosphere of the closest planet to the Sun. The NASA Glenn Research Center and the MESSENGER spacecraft integrator, the Johns Hopkins University Applied Physics Laboratory, have partnered under a Space Act Agreement to characterize a variety of critical components and materials under simulated conditions expected near Mercury. Glenn's Vacuum Facility 6, which is equipped with a solar simulator, can simulate the vacuum and high solar radiation anticipated in Mercury orbit. The MESSENGER test hardware includes a variety of materials and components that are being characterized during the Tank 6 vacuum tests, where the hardware will be exposed to up to 11 suns insolation, simulating conditions expected in Mercury orbit. In 2002, ten solar vacuum tests were conducted, including beginning of life, end of life, backside exposure, and solar panel thermal shock cycling tests. Components tested include candidate solar array panels, sensors, thermal shielding materials, and communication devices. As an example, for the solar panel thermal shock cycling test, two candidate solar array panels were suspended on a lift mechanism that lowered the panels into a liquid-nitrogen-cooled box. After reaching -140 C, the panels were then lifted out of the box and exposed to the equivalent of 6 suns (8.1 kilowatts per square meters). After five cold soak/heating cycles were completed successfully, there was no apparent degradation in panel performance. An anticipated 100-hr thermal shield life test is planned for autumn, followed by solar panel flight qualification tests in winter. Glenn's ongoing support to the MESSENGER program has been instrumental in

  5. Exploration Mission Particulate Matter Filtration Technology Performance Testing in a Simulated Spacecraft Cabin Ventilation System

    Science.gov (United States)

    Agui, Juan H.; Vijayakumar, R.; Perry, Jay L.; Frederick, Kenneth R.; Mccormick, Robert M.

    2017-01-01

    Human deep space exploration missions will require advances in long-life, low maintenance airborne particulate matter filtration technology. As one of the National Aeronautics and Space Administrations (NASA) developments in this area, a prototype of a new regenerable, multi-stage particulate matter filtration technology was tested in an International Space Station (ISS) module simulation facility. As previously reported, the key features of the filter system include inertial and media filtration with regeneration and in-place media replacement techniques. The testing facility can simulate aspects of the cabin environment aboard the ISS and contains flight-like cabin ventilation system components. The filtration technology test article was installed at the inlet of the central ventilation system duct and instrumented to provide performance data under nominal flow conditions. In-place regeneration operations were also evaluated. The real-time data included pressure drop across the filter stages, process air flow rate, ambient pressure, humidity and temperature. In addition, two video cameras positioned at the filtration technology test articles inlet and outlet were used to capture the mechanical performance of the filter media indexing operation under varying air flow rates. Recent test results are presented and future design recommendations are discussed.

  6. Operational calibration and validation of landsat data continuity mission (LDCM) sensors using the image assessment system (IAS)

    Science.gov (United States)

    Micijevic, Esad; Morfitt, Ron

    2010-01-01

    Systematic characterization and calibration of the Landsat sensors and the assessment of image data quality are performed using the Image Assessment System (IAS). The IAS was first introduced as an element of the Landsat 7 (L7) Enhanced Thematic Mapper Plus (ETM+) ground segment and recently extended to Landsat 4 (L4) and 5 (L5) Thematic Mappers (TM) and Multispectral Sensors (MSS) on-board the Landsat 1-5 satellites. In preparation for the Landsat Data Continuity Mission (LDCM), the IAS was developed for the Earth Observer 1 (EO-1) Advanced Land Imager (ALI) with a capability to assess pushbroom sensors. This paper describes the LDCM version of the IAS and how it relates to unique calibration and validation attributes of its on-board imaging sensors. The LDCM IAS system will have to handle a significantly larger number of detectors and the associated database than the previous IAS versions. An additional challenge is that the LDCM IAS must handle data from two sensors, as the LDCM products will combine the Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) spectral bands.

  7. Salt weathering in Egyptian limestone after laboratory simulations with continuous flow of salt solutions at different temperatures

    Science.gov (United States)

    Aly, Nevin; Gomez-Heras, Miguel; Hamed, Ayman; Alvarez de Buergo, Monica

    2013-04-01

    weathering in Egyptian limestone after laboratory simulations with continuous flow of salt solutions at different temperatures Nevin Aly Mohamed (1), Miguel Gomez - Heras(2), Ayman Hamed Ahmed (1), and Monica Alvarez de Buergo(2). (1) Faculty of Pet. & Min. Engineering- Suez Canal University, Suez, Egypt, (2) Instituto de Geociencias (CSIC-UCM) Madrid. Spain. Limestone is one of the most frequent building stones in Egypt and is used since the time of ancient Egyptians and salt weathering is one of the main threats to its conservation. Most of the limestone used in historical monuments in Cairo is a biomicrite extracted from the Mid-Eocene Mokattam Group. During this work, cylindrical samples (2.4 cm diameter and approx. 4.8 cm length) were subjected, in a purpose-made simulation chamber, to simulated laboratory weathering tests with fixed salt concentration (10% weight NaCl solution), at different temperatures, which were kept constant throughout each test (10, 20, 30, 40 oC). During each test, salt solutions flowed continuously imbibing samples by capilarity. Humidity within the simulation chamber was reduced using silica gel to keep it low and constant to increase evaporation rate. Temperature, humidity inside the simulation chamber and samples weight were digitally monitored during each test. Results show the advantages of the proposed experimental methodology using a continuous flow of salt solutions and shed light on the effect of temperature on the dynamics of salt crystallization on and within samples. Research funded by mission sector of high education ministry, Egypt and Geomateriales S2009/MAT-1629.

  8. A noise simulator for eLISA: Migrating LISA Pathfinder knowledge to the eLISA mission

    OpenAIRE

    Armano, M.; Audley, H.; Auger, G.; Baird, J.; Binetruy, P.; Born, Michael; Bortoluzzi, D.; Brandt, N.; Bursi, A.; Caleno, M.; Cavalleri, A.; Cesarini, A.; Cruise, M.; Danzmann, Karsten; Diepholz, I.

    2015-01-01

    We present a new technical simulator for the eLISA mission, based on state space modeling techniques and developed in MATLAB. This simulator computes the coordinate and velocity over time of each body involved in the constellation, i.e. the spacecraft and its test masses, taking into account the different disturbances and actuations. This allows studying the contribution of instrumental noises and system imperfections on the residual acceleration applied on the TMs, the latter reflecting the ...

  9. CDP a graphic system for the interactive simulation and the dynamic analysis of continuous systems

    International Nuclear Information System (INIS)

    Ricci, A.; Teolis, A.

    1973-01-01

    An IBM 2250 graphic system for the interactive simulation of continuous sytems is illustrated. Time dependent quantities can be plotted or an animated, real or schematic, representation of the system being studied can be given

  10. Construction simulation analysis of 120m continuous rigid frame bridge based on Midas Civil

    Science.gov (United States)

    Shi, Jing-xian; Ran, Zhi-hong

    2018-03-01

    In this paper, a three-dimensional finite element model of a continuous rigid frame bridge with a main span of 120m is established by the simulation and analysis of Midas Civil software. The deflection and stress of the main beam in each construction stage of continuous beam bridge are simulated and analyzed, which provides a reliable technical guarantee for the safe construction of the bridge.

  11. Continuing Professional Development: Pedagogical Practices of Interprofessional Simulation in Health Care

    Science.gov (United States)

    Nyström, Sofia; Dahlberg, Johanna; Edelbring, Samuel; Hult, Håkan; Abrandt Dahlgren, Madeleine

    2017-01-01

    The increasing complexity of health care practice makes continuing professional development (CPD) essential for health care professionals. Simulation-based training is a CPD activity that is often applied to improve interprofessional collaboration and the quality of care. The aim of this study is to explore simulation as a pedagogical practice for…

  12. Modelling and real-time simulation of continuous-discrete systems in mechatronics

    Energy Technology Data Exchange (ETDEWEB)

    Lindow, H. [Rostocker, Magdeburg (Germany)

    1996-12-31

    This work presents a methodology for simulation and modelling of systems with continuous - discrete dynamics. It derives hybrid discrete event models from Lagrange`s equations of motion. This method combines continuous mechanical, electrical and thermodynamical submodels on one hand with discrete event models an the other hand into a hybrid discrete event model. This straight forward software development avoids numeric overhead.

  13. CH4 IPDA Lidar mission data simulator and processor for MERLIN: prototype development at LMD/CNRS/Ecole Polytechnique

    Directory of Open Access Journals (Sweden)

    Olivier Chomette

    2018-01-01

    Full Text Available The MEthane Remote sensing Lidar missioN (MERLIN, currently in phase C, is a joint cooperation between France and Germany on the development of a spatial Integrated Path Differential Absorption (IPDA LIDAR (LIght Detecting And Ranging to conduct global observations of atmospheric methane. This presentation will focus on the status of a LIDAR mission data simulator and processor developed at LMD (Laboratoire de Météorologie Dynamique, Ecole Polytechnique, France, for MERLIN to assess the performances in realistic observational situations.

  14. Superior memory efficiency of quantum devices for the simulation of continuous-time stochastic processes

    Science.gov (United States)

    Elliott, Thomas J.; Gu, Mile

    2018-03-01

    Continuous-time stochastic processes pervade everyday experience, and the simulation of models of these processes is of great utility. Classical models of systems operating in continuous-time must typically track an unbounded amount of information about past behaviour, even for relatively simple models, enforcing limits on precision due to the finite memory of the machine. However, quantum machines can require less information about the past than even their optimal classical counterparts to simulate the future of discrete-time processes, and we demonstrate that this advantage extends to the continuous-time regime. Moreover, we show that this reduction in the memory requirement can be unboundedly large, allowing for arbitrary precision even with a finite quantum memory. We provide a systematic method for finding superior quantum constructions, and a protocol for analogue simulation of continuous-time renewal processes with a quantum machine.

  15. Changes in stress hormones and metabolism during a 105-day simulated Mars mission.

    Science.gov (United States)

    Strollo, Felice; Vassilieva, Galina; Ruscica, Massimiliano; Masini, Mariangela; Santucci, Daniela; Borgia, Luisa; Magni, Paolo; Celotti, Fabio; Nikiporuc, Igor

    2014-08-01

    The Mars-105 project was aimed at simulating crew's activities, workload, and communication during a mission to Mars, evaluating the homeostatic adaptations to prolonged confinement and cohabitation. Fasting plasma glucose (FPG) and insulin, C-peptide, leptin, cortisol, and NGF and BDNF plasma levels were monitored in six healthy nonsmoking male subjects taking part in a 105-d Mars mission simulation. Samples were collected from each subject before (0 wk), during (2.5 wk; 5 wk; 10 wk; 15 wk), and after confinement (+1 wk). Confinement resulted in impaired glucometabolic parameters, since FPG increased during the first 5 wk (baseline: 85.2 ± 10.8 mg · dl⁻¹; 2.5 wk: 98.4 ± 4.7 mg · dl⁻¹; 5 wk: 92.5 ± 6.0 mg · dl⁻¹) and insulin dropped at 2.5 wk (baseline: 14.4 ± 4.8 mU · L⁻¹; 2.5 wk: 7.7 ± 2.1 mU · L⁻¹), subsequently returning to baseline values. HOMA-IR paralleled plasma insulin, dropping to 1.8 ± 0.5 at 2.5 wk (baseline: 3.0 ± 1.2). At all time-points tested, plasma leptin levels were decreased (baseline: 4.4 ± 3.3 ng · dl⁻¹; 2.5 wk: 1.6 ± 1.2 ng · dl⁻¹; 5 wk: 1.3 ± 0.8 ng · dl⁻¹; 10 wk: 1.5 ± 1.1 ng · dl⁻¹; 15 wk:1.7 ± 0.8 ng · dl⁻¹), whereas cortisol levels were increased (baseline: 10.8 ± 4.9 ng · dl⁻¹; 2.5 wk: 16.8 ± 3.5 ng · dl⁻¹; 5 wk: 18.1 ± 7.6 ng · dl⁻¹; 10 wk: 18.1 ± 8.3 ng · dl⁻¹; 15 wk:14.2 ± 4.4 ng · dl⁻¹), resulting in a negative correlation between these hormones. BDNF levels increased only at 5 and 10 wk (baseline: 67.1 ± 36.0 pg · ml⁻¹; 5 wk: 164 ± 54 pg · ml⁻¹; and 10 wk: 110.2 ± 28.9 pg · ml⁻¹). The data obtained with the Mars-105 experiment suggest that environmental stress has a strong impact upon metabolic and stress response, indicating the need for further studies and the implementation of specific countermeasures.

  16. Damage assessment of mission essential buildings based on simulation studies of low yield explosives

    Science.gov (United States)

    Allen, Thomas G. L.

    2006-04-01

    There has been a lack of investigations related to low yield explosives instigated by terrorist on small but high occupancy buildings. Also, mitigating the threat of terrorist attacks against high occupancy buildings with network equipment essential to the mission of an organization is a challenging task. At the same time, it is difficult to predict how, why, and when terrorists may attack theses assets. Many factors must be considered in creating a safe building environment. Although it is possible that the dominant threat mode may change in the future, bombings have historically been a favorite tactic of terrorists. Ingredients for homemade bombs are easily obtained on the open market, as are the techniques for making bombs. Bombings are easy and quick to execute. This paper discusses the problems with and provides insights of experience gained in analyzing small scale explosions on older military base buildings. In this study, we examine the placement of various bombs on buildings using the shock wave simulation code CTH and examine the damage effects on the interior of the building, particularly the damage that is incurred on a computer center. These simulation experiments provide data on the effectiveness of a building's security and an understanding of the phenomenology of shocks as they propagate through rooms and corridors. It's purpose is to motivate researchers to take the seriousness of small yield explosives on moderately sized buildings. Visualizations from this analysis are used to understand the complex flow of the air blasts around corridors and hallways. Finally, we make suggestions for improving the mitigation of such terrorist attacks. The intent of this study is not to provide breakthrough technology, but to provide a tool and a means for analyzing the material hardness of a building and to eventually provide the incentive for more security. The information mentioned in this paper is public domain information and easily available via the

  17. An Optical Lightning Simulator in an Electrified Cloud-Resolving Model to Prepare the Future Space Lightning Missions

    Science.gov (United States)

    Bovalo, Christophe; Defer, Eric; Pinty, Jean-Pierre

    2016-04-01

    The future decade will see the launch of several space missions designed to monitor the total lightning activity. Among these missions, the American (Geostationary Lightning Mapper - GLM) and European (Lightning Imager - LI) optical detectors will be onboard geostationary satellites (GOES-R and MTG, respectively). For the first time, the total lightning activity will be monitored over the full Earth disk and at a very high temporal resolution (2 and 1 ms, respectively). Missions like the French Tool for the Analysis of Radiation from lightNIng and Sprites (TARANIS) and ISS-LIS will bring complementary information in order to better understand the lightning physics and to improve the weather prediction (nowcasting and forecasting). Such missions will generate a huge volume of new and original observations for the scientific community and weather prediction centers that have to be prepared. Moreover, before the launch of these missions, fundamental questions regarding the interpretation of the optical signal property and its relation to cloud optical thickness and lightning discharge processes need to be further investigated. An innovative approach proposed here is to use the synergy existing in the French MesoNH Cloud-Resolving Model (CRM). Indeed, MesoNH is one of the only CRM able to simulate the lifecycle of electrical charges generated within clouds through non-inductive charging process (dependent of the 1-moment microphysical scheme). The lightning flash geometry is based on a fractal law while the electrical field is diagnosed thanks to the Gauss' law. The lightning optical simulator is linked to the electrical scheme as the lightning radiance at 777.4 nm is a function of the lightning current, approximated by the charges neutralized along the lightning path. Another important part is the scattering of this signal by the hydrometeors (mainly ice particles) that is taken into account. Simulations at 1-km resolution are done over the Langmuir Laboratory (New

  18. Discrete event simulation and the resultant data storage system response in the operational mission environment of Jupiter-Saturn /Voyager/ spacecraft

    Science.gov (United States)

    Mukhopadhyay, A. K.

    1978-01-01

    The Data Storage Subsystem Simulator (DSSSIM) simulating (by ground software) occurrence of discrete events in the Voyager mission is described. Functional requirements for Data Storage Subsystems (DSS) simulation are discussed, and discrete event simulation/DSSSIM processing is covered. Four types of outputs associated with a typical DSSSIM run are presented, and DSSSIM limitations and constraints are outlined.

  19. The Epidemiology of Operation Stress during Continuing Promise 2011: A Humanitarian Response and Disaster Relief Mission aboard a US Navy Hospital Ship.

    Science.gov (United States)

    Scouten, William T; Mehalick, Melissa L; Yoder, Elizabeth; McCoy, Andrea; Brannock, Tracy; Riddle, Mark S

    2017-08-01

    Introduction Operational stress describes individual behavior in response to the occupational demands and tempo of a mission. The stress response of military personnel involved in combat and peace-keeping missions has been well-described. The spectrum of effect on medical professionals and support staff providing humanitarian assistance, however, is less well delineated. Research to date concentrates mainly on shore-based humanitarian missions. Problem The goal of the current study was to document the pattern of operational stress, describe factors responsible for it, and the extent to which these factors impact job performance in military and civilian participants of Continuing Promise 2011 (CP11), a ship-based humanitarian medical mission. This was a retrospective study of Disease Non-Battle Injury (DNBI) data from the medical sick-call clinic and from weekly self-report questionnaires for approximately 900 US military and civilian mission participants aboard the USNS COMFORT (T-AH 20). The incidence rates and job performance impact of reported Operational Stress/Mental Health (OS/MH) issues and predictors (age, rank, occupation, service branch) of OS/MH issues (depression, anxiety) were analyzed over a 22-week deployment period. Incidence rates of OS/MH complaints from the sick-call clinic were 3.7% (4.5/1,000 persons) and 12.0% (53/1,000 persons) from the self-report questionnaire. The rate of operational stress increased as the mission progressed and fluctuated during the mission according to ship movement. Approximately 57% of the responders reported no impact on job performance. Younger individuals (enlisted ranks E4-6, officer ranks O1-3), especially Air Force service members, those who had spent only one day off ship, and those who were members of specific directorates, reported the highest rates of operational stress. The overall incidence of OS/MH complaints was low in participants of CP11 but was under-estimated by clinic-based reporting. The OS

  20. The magnetic shield design and simulation of an X-ray spectrometer for Chang'E mission

    International Nuclear Information System (INIS)

    Zhang Jiayu; Wang Huanyu; Zhang Chengmo; Yang Jiawei; Liang Xiaohua; Wang Jinzhou; Cao Xuelei; Gao Min; Cui Xingzhu; Peng Wenxi

    2008-01-01

    Basic design methods about the magnetic shield of an X-ray spectrometer for Chang'E Mission were introduced in this paper. The real magnetic field distribution was obtained through the measure experiment, and according to the measure results, the simulation to evaluate the magnetic shield effect was carded on. The results showed that the collimator can play a good role in magnetic shield to the electron. (authors)

  1. Software Environment for Mission Design, Simulation, and Engineering Data Management, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — As NASA designs and develops the next generation of scientific and space exploration vehicles and missions, there is a growing need for a robust, flexible, and...

  2. An Interprofessional Approach to Continuing Education With Mass Casualty Simulation: Planning and Execution.

    Science.gov (United States)

    Saber, Deborah A; Strout, Kelley; Caruso, Lisa Swanson; Ingwell-Spolan, Charlene; Koplovsky, Aiden

    2017-10-01

    Many natural and man-made disasters require the assistance from teams of health care professionals. Knowing that continuing education about disaster simulation training is essential to nursing students, nurses, and emergency first responders (e.g., emergency medical technicians, firefighters, police officers), a university in the northeastern United States planned and implemented an interprofessional mass casualty incident (MCI) disaster simulation using the Project Management Body of Knowledge (PMBOK) management framework. The school of nursing and University Volunteer Ambulance Corps (UVAC) worked together to simulate a bus crash with disaster victim actors to provide continued education for community first responders and train nursing students on the MCI process. This article explains the simulation activity, planning process, and achieved outcomes. J Contin Educ Nurs. 2017;48(10):447-453. Copyright 2017, SLACK Incorporated.

  3. Extended object-oriented Petri net model for mission reliability simulation of repairable PMS with common cause failures

    International Nuclear Information System (INIS)

    Wu, Xin-yang; Wu, Xiao-Yue

    2015-01-01

    Phased Mission Systems (PMS) have several phases with different success criteria. Generally, traditional analytical methods need to make some assumptions when they are applied for reliability evaluation and analysis of complex PMS, for example, the components are non-repairable or components are not subjected to common cause failures (CCF). However, the evaluation and analysis results may be inapplicable when the assumptions do not agree with practical situation. In this article, we propose an extended object-oriented Petri net (EOOPN) model for mission reliability simulation of repairable PMS with CCFs. Based on object-oriented Petri net (OOPN), EOOPN defines four reusable sub-models to depict PMS at system, phase, or component levels respectively, logic transitions to depict complex components reliability logics in a more readable form, and broadcast place to transmit shared information among components synchronously. After extension, EOOPN could deal with repairable PMS with both external and internal CCFs conveniently. The mission reliability modelling, simulation and analysis using EOOPN are illustrated by a PMS example. The results demonstrate that the proposed EOOPN model is effective. - Highlights: • EOOPN model was effective in reliability simulation for repairable PMS with CCFs. • EOOPN had modular and hierarchical structure. • New elements of EOOPN made the modelling process more convenient and friendlier. • EOOPN had better model reusability and readability than other PNs

  4. Investigation of Bio-Regenerative Life Support and Trash-to-Gas Experiment on a 4-Month Mars Simulation Mission

    Science.gov (United States)

    Caraccio, Anne; Poulet, Lucie; Hintze, Paul E.; Miles, John D.

    2014-01-01

    Future crewed missions to other planets or deep space locations will require regenerative Life Support Systems (LSS) as well as recycling processes for mission waste. Constant resupply of many commodity materials will not be a sustainable option for deep space missions, nor will stowing trash on board a vehicle or at a lunar or Martian outpost. The habitable volume will decline as the volume of waste increases. A complete regenerative environmentally controlled life support system (ECLSS) on an extra-terrestrial outpost will likely include physico-chemical and biological technologies, such as bioreactors and greenhouse modules. Physico-chemical LSS do not enable food production and bio-regenerative LSS are not stable enough to be used alone in space. Mission waste that cannot be recycled into the bio-regenerative ECLSS can include excess food, food packaging, clothing, tape, urine and fecal waste. This waste will be sent to a system for converting the trash into high value products. Two crew members on a 120 day Mars analog simulation, in collaboration with Kennedy Space Centers (KSC) Trash to Gas (TtG) project investigated a semi-closed loop system that treated non-edible biomass and other logistical waste for volume reduction and conversion into useful commodities. The purpose of this study is to show how plant growth affects the amount of resources required by the habitat and how spent plant material can be recycled. Real-time data was sent to the reactor at KSC in Florida for replicating the analog mission waste for laboratory operation. This paper discusses the 120 day mission plant growth activity, logistical and plant waste management, power and water consumption effects of the plant and logistical waste, and potential energy conversion techniques using KSCs TtG technology.

  5. Investigation of Bio-Regenerative Life Support and Trash-To-Gas Experiment on a 4 Month Mars Simulation Mission

    Science.gov (United States)

    Caraccio, Anne; Poulet, Lucie; Hintze, Paul E.; Miles, John D.

    2014-01-01

    Future crewed missions to other planets or deep space locations will require regenerative Life Support Systems (LSS) as well as recycling processes for mission waste. Constant resupply of many commodity materials will not be a sustainable option for deep space missions, nor will storing trash on board a vehicle or at a lunar or Martian outpost. The habitable volume will decline as the volume of waste increases. A complete regenerative environmentally controlled life support system (ECLSS) on an extra-terrestrial outpost will likely include physico-chemical and biological technologies, such as bioreactors and greenhouse modules. Physico-chemical LSS do not enable food production and bio-regenerative LSS are not stable enough to be used alone in space. Mission waste that cannot be recycled into the bio-regenerative ECLSS can include excess food, food packaging, clothing, tape, urine and fecal waste. This waste will be sent to a system for converting the trash into the high value products. Two crew members on a 120 day Mars analog simulation, in collaboration with Kennedy Space Centers (KSC) Trash to Gas (TtG) project investigated a semi-closed loop system that treated non-edible biomass and other logistical waste for volume reduction and conversion into useful commodities. The purposes of this study are to show the how plant growth affects the amount of resources required by the habitat and how spent plant material can be recycled. Real-time data was sent to the reactor at KSC in Florida for replicating the analog mission waste for laboratory operation. This paper discusses the 120 day mission plant growth activity, logistical and plant waste management, power and water consumption effects of the plant and logistical waste, and potential energy conversion techniques using KSCs TtG reactor technology.

  6. Comparison between splines and fractional polynomials for multivariable model building with continuous covariates: a simulation study with continuous response.

    Science.gov (United States)

    Binder, Harald; Sauerbrei, Willi; Royston, Patrick

    2013-06-15

    In observational studies, many continuous or categorical covariates may be related to an outcome. Various spline-based procedures or the multivariable fractional polynomial (MFP) procedure can be used to identify important variables and functional forms for continuous covariates. This is the main aim of an explanatory model, as opposed to a model only for prediction. The type of analysis often guides the complexity of the final model. Spline-based procedures and MFP have tuning parameters for choosing the required complexity. To compare model selection approaches, we perform a simulation study in the linear regression context based on a data structure intended to reflect realistic biomedical data. We vary the sample size, variance explained and complexity parameters for model selection. We consider 15 variables. A sample size of 200 (1000) and R(2)  = 0.2 (0.8) is the scenario with the smallest (largest) amount of information. For assessing performance, we consider prediction error, correct and incorrect inclusion of covariates, qualitative measures for judging selected functional forms and further novel criteria. From limited information, a suitable explanatory model cannot be obtained. Prediction performance from all types of models is similar. With a medium amount of information, MFP performs better than splines on several criteria. MFP better recovers simpler functions, whereas splines better recover more complex functions. For a large amount of information and no local structure, MFP and the spline procedures often select similar explanatory models. Copyright © 2012 John Wiley & Sons, Ltd.

  7. Continuous analysis of parotid saliva during resting and short-duration simulated chewing

    NARCIS (Netherlands)

    Neyraud, E.; Bult, J.H.F.; Dransfield, E.

    2009-01-01

    Objective: Parotid saliva flow is increased by mastication and its composition is also modified. The aim of this work was to clarify the relationships between flow rate, pH and protein concentration, during resting and short-duration simulated chewing, using continuous and fractional saliva

  8. A continuous-discontinuous approach to simulate failure of quasi-brittle materials

    NARCIS (Netherlands)

    Moonen, P.; Sluys, L.J.; Carmeliet, J.

    2009-01-01

    A continuous-discontinuous approach to simulate failure is presented. The formulation covers both diffuse damage processes in the bulk material as well as the initiation and propagation of discrete cracks. Comparison with experimental data on layered sandstone shows that the modeling strategy

  9. Experiential learning and cognitive tools: The impact of simulations on conceptual change in continuing healthcare education

    NARCIS (Netherlands)

    Reeves, Thomas; Reeves, Patricia; McKenney, Susan

    2014-01-01

    Reeves, T. C., Reeves, P. M., & McKenney, S. (2013). Experiential learning and cognitive tools: The impact of simulations on conceptual change in continuing healthcare education. In J. M. Spector, B. B. Lockee, S. E. Smaldino, & M. Herring (eds.), Learning, problem solving, and mindtools: Essays in

  10. Alignment of Teacher and Student Perceptions on the Continued Use of Business Simulation Games

    Science.gov (United States)

    Tao, Yu-Hui; Cheng, Chieh-Jen; Sun, Szu-Yuan

    2012-01-01

    The higher education system in Taiwan has increasingly adopted business simulation games (BSGs) in recent years. Previous BSG benefit research has shifted focus from learning performance to motivation due to mixed results. One recent study empirically investigated student perceptions on the continued use of BSGs; however, the counterpart of higher…

  11. Numerical simulation of continuous cooling of a low alloy steel to predict microstructure and hardness

    International Nuclear Information System (INIS)

    Kakhki, M Eshraghi; Kermanpur, A; Golozar, M A

    2009-01-01

    In this work, a numerical model was developed to simulate the continuous cooling of a low alloy steel. In order to simulate the kinetics of diffusional phase transformations, the Johnson–Mehl–Avrami–Kolmogorov (JMAK) equation and additivity rule were employed, while a new model was applied for martensitic transformation. In addition, a novel approach was applied for computing the actual phase fractions in the multiphase steel. Effects of latent heat release during phase transformations, temperature and phase fractions on the variation of thermo-physical properties were considered. The developed numerical model was applied to simulate the cooling process during the Jominy end quench test as well as the quenching of a steel gear in water and oil. In this respect, precise models were used to simulate the complex boundary conditions in the Jominy test and a stainless steel probe was used for determining the heat transfer coefficients of quenching media by an inverse method. The present model was validated against cooling curve measurements, metallographic analysis and hardness tests. Good agreement was found between the experimental and simulation results. This model is able to simulate the continuous cooling and kinetics of phase transformation and to predict the final distribution of microstructures and hardness in low alloy steels

  12. MASADA: A MODELING AND SIMULATION AUTOMATED DATA ANALYSIS FRAMEWORK FOR CONTINUOUS DATA-INTENSIVE VALIDATION OF SIMULATION MODELS

    CERN Document Server

    Foguelman, Daniel Jacob; The ATLAS collaboration

    2016-01-01

    Complex networked computer systems are usually subjected to upgrades and enhancements on a continuous basis. Modeling and simulation of such systems helps with guiding their engineering processes, in particular when testing candi- date design alternatives directly on the real system is not an option. Models are built and simulation exercises are run guided by specific research and/or design questions. A vast amount of operational conditions for the real system need to be assumed in order to focus on the relevant questions at hand. A typical boundary condition for computer systems is the exogenously imposed workload. Meanwhile, in typical projects huge amounts of monitoring information are logged and stored with the purpose of studying the system’s performance in search for improvements. Also research questions change as systems’ operational conditions vary throughout its lifetime. This context poses many challenges to determine the validity of simulation models. As the behavioral empirical base of the sys...

  13. MASADA: A Modeling and Simulation Automated Data Analysis framework for continuous data-intensive validation of simulation models

    CERN Document Server

    Foguelman, Daniel Jacob; The ATLAS collaboration

    2016-01-01

    Complex networked computer systems are usually subjected to upgrades and enhancements on a continuous basis. Modeling and simulation of such systems helps with guiding their engineering processes, in particular when testing candi- date design alternatives directly on the real system is not an option. Models are built and simulation exercises are run guided by specific research and/or design questions. A vast amount of operational conditions for the real system need to be assumed in order to focus on the relevant questions at hand. A typical boundary condition for computer systems is the exogenously imposed workload. Meanwhile, in typical projects huge amounts of monitoring information are logged and stored with the purpose of studying the system’s performance in search for improvements. Also research questions change as systems’ operational conditions vary throughout its lifetime. This context poses many challenges to determine the validity of simulation models. As the behavioral empirical base of the sys...

  14. Integration of Continuous-Time Dynamics in a Spiking Neural Network Simulator

    Directory of Open Access Journals (Sweden)

    Jan Hahne

    2017-05-01

    Full Text Available Contemporary modeling approaches to the dynamics of neural networks include two important classes of models: biologically grounded spiking neuron models and functionally inspired rate-based units. We present a unified simulation framework that supports the combination of the two for multi-scale modeling, enables the quantitative validation of mean-field approaches by spiking network simulations, and provides an increase in reliability by usage of the same simulation code and the same network model specifications for both model classes. While most spiking simulations rely on the communication of discrete events, rate models require time-continuous interactions between neurons. Exploiting the conceptual similarity to the inclusion of gap junctions in spiking network simulations, we arrive at a reference implementation of instantaneous and delayed interactions between rate-based models in a spiking network simulator. The separation of rate dynamics from the general connection and communication infrastructure ensures flexibility of the framework. In addition to the standard implementation we present an iterative approach based on waveform-relaxation techniques to reduce communication and increase performance for large-scale simulations of rate-based models with instantaneous interactions. Finally we demonstrate the broad applicability of the framework by considering various examples from the literature, ranging from random networks to neural-field models. The study provides the prerequisite for interactions between rate-based and spiking models in a joint simulation.

  15. Integration of Continuous-Time Dynamics in a Spiking Neural Network Simulator.

    Science.gov (United States)

    Hahne, Jan; Dahmen, David; Schuecker, Jannis; Frommer, Andreas; Bolten, Matthias; Helias, Moritz; Diesmann, Markus

    2017-01-01

    Contemporary modeling approaches to the dynamics of neural networks include two important classes of models: biologically grounded spiking neuron models and functionally inspired rate-based units. We present a unified simulation framework that supports the combination of the two for multi-scale modeling, enables the quantitative validation of mean-field approaches by spiking network simulations, and provides an increase in reliability by usage of the same simulation code and the same network model specifications for both model classes. While most spiking simulations rely on the communication of discrete events, rate models require time-continuous interactions between neurons. Exploiting the conceptual similarity to the inclusion of gap junctions in spiking network simulations, we arrive at a reference implementation of instantaneous and delayed interactions between rate-based models in a spiking network simulator. The separation of rate dynamics from the general connection and communication infrastructure ensures flexibility of the framework. In addition to the standard implementation we present an iterative approach based on waveform-relaxation techniques to reduce communication and increase performance for large-scale simulations of rate-based models with instantaneous interactions. Finally we demonstrate the broad applicability of the framework by considering various examples from the literature, ranging from random networks to neural-field models. The study provides the prerequisite for interactions between rate-based and spiking models in a joint simulation.

  16. Jake Garn Mission Simulator and Training Facility, Building 5, Historical Documentation

    Science.gov (United States)

    Slovinac, Trish; Deming, Joan

    2010-01-01

    In response to President George W. Bush's announcement in January 2004 that the Space Shuttle Program (SSP) would end in 2010, the National Aeronautics and Space Administration (NASA) completed a nation-wide historical survey and evaluation of NASA-owned facilities and properties (real property assets) at all its Centers and component facilities. The buildings and structures which supported the SSP were inventoried and assessed as per the criteria of eligibility for listing in the National Register of Historic Places (NRHP) in the context of this program. This study was performed in compliance with Section 110 of the National Historic Preservation Act (NHPA) of 1966 (Public Law 89-665), as amended; the National Environmental Policy Act (NEPA) of 1969 (Public Law 91-190); Executive Order (EO) 11593: Protection and Enhancement of the Cultural Environment; EO 13287, Preserve America, and other relevant legislation. As part of this nation-wide study, in September 2006, historical survey and evaluation of NASA-owned and managed facilities at was conducted by NASA's Lyndon B. Johnson Space Center (JSC) in Houston, Texas. The results of this study are presented in a report entitled, "Survey and Evaluation of NASA-owned Historic Facilities and Properties in the Context of the U.S. Space Shuttle Program, Lyndon B. Johnson Space Center, Houston, Texas," prepared in November 2007 by NASA JSC's contractor, Archaeological Consultants, Inc. As a result of this survey, the Jake Gam Mission Simulator and Training Facility (Building 5) was determined eligible for listing in the NRHP, with concurrence by the Texas State Historic Preservation Officer (SHPO). The survey concluded that Building 5 is eligible for the NRHP under Criteria A and C in the context of the U.S. Space Shuttle program (1969-2010). Because it has achieved significance within the past 50 years, Criteria Consideration G applies. At the time of this documentation, Building 5 was still used to support the SSP as an

  17. Discrete event simulation tool for analysis of qualitative models of continuous processing systems

    Science.gov (United States)

    Malin, Jane T. (Inventor); Basham, Bryan D. (Inventor); Harris, Richard A. (Inventor)

    1990-01-01

    An artificial intelligence design and qualitative modeling tool is disclosed for creating computer models and simulating continuous activities, functions, and/or behavior using developed discrete event techniques. Conveniently, the tool is organized in four modules: library design module, model construction module, simulation module, and experimentation and analysis. The library design module supports the building of library knowledge including component classes and elements pertinent to a particular domain of continuous activities, functions, and behavior being modeled. The continuous behavior is defined discretely with respect to invocation statements, effect statements, and time delays. The functionality of the components is defined in terms of variable cluster instances, independent processes, and modes, further defined in terms of mode transition processes and mode dependent processes. Model construction utilizes the hierarchy of libraries and connects them with appropriate relations. The simulation executes a specialized initialization routine and executes events in a manner that includes selective inherency of characteristics through a time and event schema until the event queue in the simulator is emptied. The experimentation and analysis module supports analysis through the generation of appropriate log files and graphics developments and includes the ability of log file comparisons.

  18. Integrated simulation of continuous-scale and discrete-scale radiative transfer in metal foams

    Science.gov (United States)

    Xia, Xin-Lin; Li, Yang; Sun, Chuang; Ai, Qing; Tan, He-Ping

    2018-06-01

    A novel integrated simulation of radiative transfer in metal foams is presented. It integrates the continuous-scale simulation with the direct discrete-scale simulation in a single computational domain. It relies on the coupling of the real discrete-scale foam geometry with the equivalent continuous-scale medium through a specially defined scale-coupled zone. This zone holds continuous but nonhomogeneous volumetric radiative properties. The scale-coupled approach is compared to the traditional continuous-scale approach using volumetric radiative properties in the equivalent participating medium and to the direct discrete-scale approach employing the real 3D foam geometry obtained by computed tomography. All the analyses are based on geometrical optics. The Monte Carlo ray-tracing procedure is used for computations of the absorbed radiative fluxes and the apparent radiative behaviors of metal foams. The results obtained by the three approaches are in tenable agreement. The scale-coupled approach is fully validated in calculating the apparent radiative behaviors of metal foams composed of very absorbing to very reflective struts and that composed of very rough to very smooth struts. This new approach leads to a reduction in computational time by approximately one order of magnitude compared to the direct discrete-scale approach. Meanwhile, it can offer information on the local geometry-dependent feature and at the same time the equivalent feature in an integrated simulation. This new approach is promising to combine the advantages of the continuous-scale approach (rapid calculations) and direct discrete-scale approach (accurate prediction of local radiative quantities).

  19. Continuity and Innovation. 25 years of simulator training for nuclear power plants in Germany

    International Nuclear Information System (INIS)

    Lindauer, E.

    2002-01-01

    The first training simulator for nuclear power plant personnel in Germany was commissioned twenty-five years ago. This date was rather early, both when measured by the development of the German nuclear power program and when compared with the international situation. This farsighted decision demonstrates the importance nuclear power plant operators attach to the sound training of plant personnel. The consistent, and also costly, further development over the past twenty-five years shows that this attitude has not changed. A modern simulator center was built at a total cost of approx. 250 million Euro which can be characterized briefly as follows: - 13 full simulators cover most specific features of existing nuclear power plants. These simulators are backfitted continuously and represent the current state of simulation technology. - Their experience over many years has allowed the staff of approx. 140 to accumulate a high level of know-how in training and simulator operation. Learning from experience is greatly assisted by the fact that all activities are concentrated at one center. - The way in which the center is organized ensures close cooperation with the nuclear power plants responsible for the training of their personnel. - There is a systematic training concept which is being actively developed further. Some of the main developments in recent years include training for emergencies; intensified training in behavioral aspects, such as communication and leadership; the use of simulators for emergency drills; testing of modifications, etc. (orig.) [de

  20. Modelling of slaughterhouse solid waste anaerobic digestion: determination of parameters and continuous reactor simulation.

    Science.gov (United States)

    López, Iván; Borzacconi, Liliana

    2010-10-01

    A model based on the work of Angelidaki et al. (1993) was applied to simulate the anaerobic biodegradation of ruminal contents. In this study, two fractions of solids with different biodegradation rates were considered. A first-order kinetic was used for the easily biodegradable fraction and a kinetic expression that is function of the extracellular enzyme concentration was used for the slowly biodegradable fraction. Batch experiments were performed to obtain an accumulated methane curve that was then used to obtain the model parameters. For this determination, a methodology derived from the "multiple-shooting" method was successfully used. Monte Carlo simulations allowed a confidence range to be obtained for each parameter. Simulations of a continuous reactor were performed using the optimal set of model parameters. The final steady-states were determined as functions of the operational conditions (solids load and residence time). The simulations showed that methane flow peaked at a flow rate of 0.5-0.8 Nm(3)/d/m(reactor)(3) at a residence time of 10-20 days. Simulations allow the adequate selection of operating conditions of a continuous reactor. (c) 2010 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

  2. CFD simulation of transient stage of continuous countercurrent hydrolysis of canola oil

    KAUST Repository

    Wang, Weicheng

    2012-08-01

    Computational Fluid Dynamic (CFD) modeling of a continuous countercurrent hydrolysis process was performed using ANSYS-CFX. The liquid properties and flow behavior such as density, specific heats, dynamic viscosity, thermal conductivity, and thermal expansivity as well as water solubility of the hydrolysis components triglyceride, diglyceride, monoglyceride, free fatty acid, and glycerol were calculated. Chemical kinetics for the hydrolysis reactions were simulated in this model by applying Arrhenius parameters. The simulation was based on actual experimental reaction conditions including temperature and water-to-oil ratio. The results not only have good agreement with experimental data but also show instantaneous distributions of concentrations of every component in hydrolysis reaction. This model provided visible insight into the continuous countercurrent hydrolysis process. © 2012 Elsevier Ltd.

  3. CFD simulation of transient stage of continuous countercurrent hydrolysis of canola oil

    KAUST Repository

    Wang, Weicheng; Natelson, Robert H.; Stikeleather, Larry F.; Roberts, William L.

    2012-01-01

    Computational Fluid Dynamic (CFD) modeling of a continuous countercurrent hydrolysis process was performed using ANSYS-CFX. The liquid properties and flow behavior such as density, specific heats, dynamic viscosity, thermal conductivity, and thermal expansivity as well as water solubility of the hydrolysis components triglyceride, diglyceride, monoglyceride, free fatty acid, and glycerol were calculated. Chemical kinetics for the hydrolysis reactions were simulated in this model by applying Arrhenius parameters. The simulation was based on actual experimental reaction conditions including temperature and water-to-oil ratio. The results not only have good agreement with experimental data but also show instantaneous distributions of concentrations of every component in hydrolysis reaction. This model provided visible insight into the continuous countercurrent hydrolysis process. © 2012 Elsevier Ltd.

  4. Physical time scale in kinetic Monte Carlo simulations of continuous-time Markov chains.

    Science.gov (United States)

    Serebrinsky, Santiago A

    2011-03-01

    We rigorously establish a physical time scale for a general class of kinetic Monte Carlo algorithms for the simulation of continuous-time Markov chains. This class of algorithms encompasses rejection-free (or BKL) and rejection (or "standard") algorithms. For rejection algorithms, it was formerly considered that the availability of a physical time scale (instead of Monte Carlo steps) was empirical, at best. Use of Monte Carlo steps as a time unit now becomes completely unnecessary.

  5. Is Changing Teaching Practice the Mission Impossible? A Case Study of Continuing Professional Development for Primary School Teachers in Senegal

    Science.gov (United States)

    Miyazaki, Takeshi

    2016-01-01

    This paper reports on research into a continuing professional development (CPD) project, "Projet de Renforcement de l'Enseignement des Mathématiques, des Sciences et de la Technologie" (PREMST) [Strengthening Mathematics, Science, and Technologies in Education Project]. The literature review reveals few examples of CPD changing the…

  6. System Diagnostic Builder - A rule generation tool for expert systems that do intelligent data evaluation. [applied to Shuttle Mission Simulator

    Science.gov (United States)

    Nieten, Joseph; Burke, Roger

    1993-01-01

    Consideration is given to the System Diagnostic Builder (SDB), an automated knowledge acquisition tool using state-of-the-art AI technologies. The SDB employs an inductive machine learning technique to generate rules from data sets that are classified by a subject matter expert. Thus, data are captured from the subject system, classified, and used to drive the rule generation process. These rule bases are used to represent the observable behavior of the subject system, and to represent knowledge about this system. The knowledge bases captured from the Shuttle Mission Simulator can be used as black box simulations by the Intelligent Computer Aided Training devices. The SDB can also be used to construct knowledge bases for the process control industry, such as chemical production or oil and gas production.

  7. Radiation beamline testbeds for the simulation of planetary and spacecraft environments for human and robotic mission risk assessment

    Science.gov (United States)

    Wilkins, Richard

    The Center for Radiation Engineering and Science for Space Exploration (CRESSE) at Prairie View A&M University, Prairie View, Texas, USA, is establishing an integrated, multi-disciplinary research program on the scientific and engineering challenges faced by NASA and the inter-national space community caused by space radiation. CRESSE focuses on space radiation research directly applicable to astronaut health and safety during future long term, deep space missions, including Martian, lunar, and other planetary body missions beyond low earth orbit. The research approach will consist of experimental and theoretical radiation modeling studies utilizing particle accelerator facilities including: 1. NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory; 2. Proton Synchrotron at Loma Linda University Med-ical Center; and 3. Los Alamos Neutron Science Center (LANSCE) at Los Alamos National Laboratory. Specifically, CRESSE investigators are designing, developing, and building experimental test beds that simulate the lunar and Martian radiation environments for experiments focused on risk assessment for astronauts and instrumentation. The testbeds have been designated the Bioastronautics Experimental Research Testbeds for Environmental Radiation Nostrum Investigations and Education (BERT and ERNIE). The designs of BERT and ERNIE will allow for a high degree of flexibility and adaptability to modify experimental configurations to simulate planetary surface environments, planetary habitats, and spacecraft interiors. In the nominal configuration, BERT and ERIE will consist of a set of experimental zones that will simulate the planetary atmosphere (Solid CO2 in the case of the Martian surface.), the planetary surface, and sub-surface regions. These experimental zones can be used for dosimetry, shielding, biological, and electronic effects radiation studies in support of space exploration missions. BERT and ERNIE are designed to be compatible with the

  8. Feasibility of using continuous X-ray to simulate cable response under X-ray environment

    International Nuclear Information System (INIS)

    Ma Liang; Zhou Hui; Cheng Yinhui; Wu Wei; Li Jinxi; Zhao Mo; Guo Jinghai

    2014-01-01

    The mechanism and simulating method of cable response induced by X-ray were researched, and the relationship of cable response irradiated by continuous and pulsed X-ray was analyzed. A one-dimension model of strip line irradiation response of X-ray was given, which includes the gap between cable shield and dielectric, and induced conductivity in cable dielectric. The calculation result using the model indicates that the cable responses of continuous and rectangular-pulsed X-ray have the similar current waveform and the same gap voltages. Therefore, continuous X-ray can be used to research some cable responses of pulsed X-ray irradiation under the mechanism described in the one-dimension model. (authors)

  9. A simulation of the Four-way lunar Lander-Orbiter tracking mode for the Chang'E-5 mission

    Science.gov (United States)

    Li, Fei; Ye, Mao; Yan, Jianguo; Hao, Weifeng; Barriot, Jean-Pierre

    2016-06-01

    The Chang'E-5 mission is the third phase of the Chinese Lunar Exploration Program and will collect and return lunar samples. After sampling, the Orbiter and the ascent vehicle will rendezvous and dock, and both spacecraft will require high precision orbit navigation. In this paper, we present a novel tracking mode-Four-way lunar Lander-Orbiter tracking that possibly can be employed during the Chang'E-5 mission. The mathematical formulas for the Four-way lunar Lander-Orbiter tracking mode are given and implemented in our newly-designed lunar spacecraft orbit determination and gravity field recovery software, the LUnar Gravity REcovery and Analysis Software/System (LUGREAS). The simulated observables permit analysis of the potential contribution Four-way lunar Lander-Orbiter tracking could make to precision orbit determination for the Orbiter. Our results show that the Four-way lunar Lander-Orbiter Range Rate has better geometric constraint on the orbit, and is more sensitive than the traditional two-way range rate that only tracks data between the Earth station and lunar Orbiter. After combining the Four-way lunar Lander-Orbiter Range Rate data with the traditional two-way range rate data and considering the Lander position error and lunar gravity field error, the accuracy of precision orbit determination for the Orbiter in the simulation was improved significantly, with the biggest improvement being one order of magnitude, and the Lander position could be constrained to sub-meter level. This new tracking mode could provide a reference for the Chang'E-5 mission and have enormous potential for the positioning of future lunar farside Lander due to its relay characteristic.

  10. Why continuous simulation? The role of antecedent moisture in design flood estimation

    Science.gov (United States)

    Pathiraja, S.; Westra, S.; Sharma, A.

    2012-06-01

    Continuous simulation for design flood estimation is increasingly becoming a viable alternative to traditional event-based methods. The advantage of continuous simulation approaches is that the catchment moisture state prior to the flood-producing rainfall event is implicitly incorporated within the modeling framework, provided the model has been calibrated and validated to produce reasonable simulations. This contrasts with event-based models in which both information about the expected sequence of rainfall and evaporation preceding the flood-producing rainfall event, as well as catchment storage and infiltration properties, are commonly pooled together into a single set of "loss" parameters which require adjustment through the process of calibration. To identify the importance of accounting for antecedent moisture in flood modeling, this paper uses a continuous rainfall-runoff model calibrated to 45 catchments in the Murray-Darling Basin in Australia. Flood peaks derived using the historical daily rainfall record are compared with those derived using resampled daily rainfall, for which the sequencing of wet and dry days preceding the heavy rainfall event is removed. The analysis shows that there is a consistent underestimation of the design flood events when antecedent moisture is not properly simulated, which can be as much as 30% when only 1 or 2 days of antecedent rainfall are considered, compared to 5% when this is extended to 60 days of prior rainfall. These results show that, in general, it is necessary to consider both short-term memory in rainfall associated with synoptic scale dependence, as well as longer-term memory at seasonal or longer time scale variability in order to obtain accurate design flood estimates.

  11. A MATLAB based Distributed Real-time Simulation of Lander-Orbiter-Earth Communication for Lunar Missions

    Science.gov (United States)

    Choudhury, Diptyajit; Angeloski, Aleksandar; Ziah, Haseeb; Buchholz, Hilmar; Landsman, Andre; Gupta, Amitava; Mitra, Tiyasa

    Lunar explorations often involve use of a lunar lander , a rover [1],[2] and an orbiter which rotates around the moon with a fixed radius. The orbiters are usually lunar satellites orbiting along a polar orbit to ensure visibility with respect to the rover and the Earth Station although with varying latency. Communication in such deep space missions is usually done using a specialized protocol like Proximity-1[3]. MATLAB simulation of Proximity-1 have been attempted by some contemporary researchers[4] to simulate all features like transmission control, delay etc. In this paper it is attempted to simulate, in real time, the communication between a tracking station on earth (earth station), a lunar orbiter and a lunar rover using concepts of Distributed Real-time Simulation(DRTS).The objective of the simulation is to simulate, in real-time, the time varying communication delays associated with the communicating elements with a facility to integrate specific simulation modules to study different aspects e.g. response due to a specific control command from the earth station to be executed by the rover. The hardware platform comprises four single board computers operating as stand-alone real time systems (developed by MATLAB xPC target and inter-networked using UDP-IP protocol). A time triggered DRTS approach is adopted. The earth station, the orbiter and the rover are programmed as three standalone real-time processes representing the communicating elements in the system. Communication from one communicating element to another constitutes an event which passes a state message from one element to another, augmenting the state of the latter. These events are handled by an event scheduler which is the fourth real-time process. The event scheduler simulates the delay in space communication taking into consideration the distance between the communicating elements. A unique time synchronization algorithm is developed which takes into account the large latencies in space

  12. Prospects of the ICESat-2 Laser Altimetry Mission for Savanna Ecosystem Structural Studies Based on Airborne Simulation Data

    Science.gov (United States)

    Gwenzi, David; Lefsky, Michael A.; Suchdeo, Vijay P.; Harding, David J.

    2016-01-01

    The next planned spaceborne lidar mission is the Ice, Cloud and land Elevation Satellite 2 (ICESat-2), which will use the Advanced Topographic Laser Altimeter System (ATLAS) sensor, a photon counting technique. To pre-validate the capability of this mission for studying three dimensional vegetation structure in savannas, we assessed the potential of the measurement approach to estimate canopy height in an oak savanna landscape. We used data from the Multiple Altimeter Beam Experimental Lidar (MABEL), an airborne photon counting lidar sensor developed by NASA's Goddard Space Flight Center. ATLAS-like data was generated using the MATLAS simulator, which adjusts MABEL data's detected number of signal and noise photons to that expected from the ATLAS instrument. Transects flown over the Tejon ranch conservancy in Kern County, California, USA were used for this work. For each transect we chose to use data from the near infrared channel that had the highest number of photons. We segmented each transect into 50 m, 25 m and 14 m long blocks and aggregated the photons in each block into a histogram based on their elevation values. We then used an automated algorithm to identify cut off points where the cumulative density of photons from the highest elevation indicates the presence of the canopy top and likewise where such cumulative density from the lowest elevation indicates the mean terrain elevation. MABEL derived height metrics were moderately correlated to discrete return lidar (DRL) derived height metrics r(sub 2) and RMSE values ranging from 0.60 to 0.73 and 2.9 m to 4.4 m respectively) but MATLAS simulation resulted in more modest correlations with DRL indices r(sub 2) ranging from 0.5 to 0.64 and RMSE from 3.6 m to 4.6 m). Simulations also indicated that the expected number of signal photons from ATLAS will be substantially lower, a situation that reduces canopy height estimation precision especially in areas of low density vegetation cover. On the basis of the

  13. Integrating continuous stocks and flows into state-and-transition simulation models of landscape change

    Science.gov (United States)

    Daniel, Colin J.; Sleeter, Benjamin M.; Frid, Leonardo; Fortin, Marie-Josée

    2018-01-01

    State-and-transition simulation models (STSMs) provide a general framework for forecasting landscape dynamics, including projections of both vegetation and land-use/land-cover (LULC) change. The STSM method divides a landscape into spatially-referenced cells and then simulates the state of each cell forward in time, as a discrete-time stochastic process using a Monte Carlo approach, in response to any number of possible transitions. A current limitation of the STSM method, however, is that all of the state variables must be discrete.Here we present a new approach for extending a STSM, in order to account for continuous state variables, called a state-and-transition simulation model with stocks and flows (STSM-SF). The STSM-SF method allows for any number of continuous stocks to be defined for every spatial cell in the STSM, along with a suite of continuous flows specifying the rates at which stock levels change over time. The change in the level of each stock is then simulated forward in time, for each spatial cell, as a discrete-time stochastic process. The method differs from the traditional systems dynamics approach to stock-flow modelling in that the stocks and flows can be spatially-explicit, and the flows can be expressed as a function of the STSM states and transitions.We demonstrate the STSM-SF method by integrating a spatially-explicit carbon (C) budget model with a STSM of LULC change for the state of Hawai'i, USA. In this example, continuous stocks are pools of terrestrial C, while the flows are the possible fluxes of C between these pools. Importantly, several of these C fluxes are triggered by corresponding LULC transitions in the STSM. Model outputs include changes in the spatial and temporal distribution of C pools and fluxes across the landscape in response to projected future changes in LULC over the next 50 years.The new STSM-SF method allows both discrete and continuous state variables to be integrated into a STSM, including interactions between

  14. Thermal simulations of the STIX instrument for ESA Solar Orbiter mission

    Science.gov (United States)

    Białek, Agata; Severyn, Karol; Grassmann, Kamil; Orleańskii, Piotr; Skup, Konrad R.; Arnold, Nicolas; Gröbelbauer, Hans-Peter; Hurford, Gordon J.; Krucker, Samuel; Bauer, Svend-Marian; Mann, Gottfied; Önel, Hakan; Bernet, Adeline; Blecha, Luc; Grimm, Oliver; Limousin, Olivier; Martignac, Jerome; Meuris, Aline

    2013-07-01

    The ESA Solar Orbiter mission, planned to be launched in 2017, is going to study the Sun with ten different instruments including the Spectrometer/Telescope for Imaging X-rays - STIX. The thermal environment on the elliptical orbit around the Sun - 0.28 AU at perihelion and 0.952 AU at aphelion - is extreme, where at one point of the orbit is very hot, while on another very cold. That makes the requirements for the heat fluxes exchanged between each instrument and the spacecraft, as well as between the instrument - subsystems, very restrictive. Here the authors discuss the thermal design with respect to the defined requirements and present the results of the thermal analyses performed with ESATAN TMS software.

  15. Molecular dynamics simulation of continuous nanoflow transport through the uneven wettability channel

    Science.gov (United States)

    Zhang, Kai; Wang, Feng-hui; Lu, Yong-jun

    2018-01-01

    It is necessary to understand and predict the behavior of continuous nanoflow, especially inside the nanochannel with uneven wettability. Because the properties of fluid confined in the nanochannel are different from the macroscopic fluid, molecular level understanding is critical for future applications. In this work, a series of molecular dynamics simulations were executed to investigate the effect of the wettability gradient on the continuous nanofluid. In the simulations, different osmotic pressures were applied to make the water transport through different nanochannels. Simulation data was analyzed to obtain water flow rate, shear viscosity, capillary force, density distributions along the height directions of channel and apparent friction factor. Results show that the uneven wettability has a significant effect on the transportation of confined water only under the proper applied osmotic pressure and the height of channel. Under the appropriate conditions, the uneven wettability has a promotion on the transportation of water when it is at the exit of channel. When the uneven wettability locates in the entrance and middle of the channel, the uneven wettability will hinder the transportation of water. Especially, it is worth mentioning that there is a special phenomenon when the height of the nanochannel becomes 0.8 nm. Depending on the applied osmotic pressure, the uneven wettability has a double-sided effect on the confined fluid inside the channel with H = 0.8 nm. Our work may contribute to the design of nanochannels.

  16. Simulating continuous-time Hamiltonian dynamics by way of a discrete-time quantum walk

    International Nuclear Information System (INIS)

    Schmitz, A.T.; Schwalm, W.A.

    2016-01-01

    Much effort has been made to connect the continuous-time and discrete-time quantum walks. We present a method for making that connection for a general graph Hamiltonian on a bigraph. Furthermore, such a scheme may be adapted for simulating discretized quantum models on a quantum computer. A coin operator is found for the discrete-time quantum walk which exhibits the same dynamics as the continuous-time evolution. Given the spectral decomposition of the graph Hamiltonian and certain restrictions, the discrete-time evolution is solved for explicitly and understood at or near important values of the parameters. Finally, this scheme is connected to past results for the 1D chain. - Highlights: • A discrete-time quantum walk is purposed which approximates a continuous-time quantum walk. • The purposed quantum walk could be used to simulate Hamiltonian dynamics on a quantum computer. • Given the spectra decomposition of the Hamiltonian, the quantum walk is solved explicitly. • The method is demonstrated and connected to previous work done on the 1D chain.

  17. Adoption of Test Driven Development and Continuous Integration for the Development of the Trick Simulation Toolkit

    Science.gov (United States)

    Penn, John M.

    2013-01-01

    This paper describes the adoption of a Test Driven Development approach and a Continuous Integration System in the development of the Trick Simulation Toolkit, a generic simulation development environment for creating high fidelity training and engineering simulations at the NASA/Johnson Space Center and many other NASA facilities. It describes what was learned and the significant benefits seen, such as fast, thorough, and clear test feedback every time code is checked-in to the code repository. It also describes a system that encourages development of code that is much more flexible, maintainable, and reliable. The Trick Simulation Toolkit development environment provides a common architecture for user-defined simulations. Trick builds executable simulations using user-supplied simulation-definition files (S_define) and user supplied "model code". For each Trick-based simulation, Trick automatically provides job scheduling, checkpoint / restore, data-recording, interactive variable manipulation (variable server), and an input-processor. Also included are tools for plotting recorded data and various other supporting tools and libraries. Trick is written in C/C++ and Java and supports both Linux and MacOSX. Prior to adopting this new development approach, Trick testing consisted primarily of running a few large simulations, with the hope that their complexity and scale would exercise most of Trick's code and expose any recently introduced bugs. Unsurprising, this approach yielded inconsistent results. It was obvious that a more systematic, thorough approach was required. After seeing examples of some Java-based projects that used the JUnit test framework, similar test frameworks for C and C++ were sought. Several were found, all clearly inspired by JUnit. Googletest, a freely available Open source testing framework, was selected as the most appropriate and capable. The new approach was implemented while rewriting the Trick memory management component, to eliminate a

  18. Computational Fluid Dynamics simulation of hydrothermal liquefaction of microalgae in a continuous plug-flow reactor.

    Science.gov (United States)

    Ranganathan, Panneerselvam; Savithri, Sivaraman

    2018-06-01

    Computational Fluid Dynamics (CFD) technique is used in this work to simulate the hydrothermal liquefaction of Nannochloropsis sp. microalgae in a lab-scale continuous plug-flow reactor to understand the fluid dynamics, heat transfer, and reaction kinetics in a HTL reactor under hydrothermal condition. The temperature profile in the reactor and the yield of HTL products from the present simulation are obtained and they are validated with the experimental data available in the literature. Furthermore, the parametric study is carried out to study the effect of slurry flow rate, reactor temperature, and external heat transfer coefficient on the yield of products. Though the model predictions are satisfactory in comparison with the experimental results, it still needs to be improved for better prediction of the product yields. This improved model will be considered as a baseline for design and scale-up of large-scale HTL reactor. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Simulation of transient fluid flow in mold region during steel continuous casting

    International Nuclear Information System (INIS)

    Liu, R; Thomas, B G; Sengupta, J

    2012-01-01

    A system of models has been developed to study transient flow during continuous casting and applied to simulate an event of multiple stopper-rod movements. It includes four sub-models to incorporate different aspects in this transient event. A three-dimensional (3-D) porous-flow model of the nozzle wall calculates the rate argon gas flow into the liquid steel, and the initial mean bubble size is estimated. Transient CFD models simulate multiphase flow of steel and gas bubbles in the Submerged Entry Nozzle (SEN) and mold and have been validated with experimental data from both nail dipping and Sub-meniscus Velocity Control (SVC) measurements. To obtain the transient inlet boundary conditions for the simulation, two semi-empirical models, a stopper-rod-position based model and a metal-level-based model, predict the liquid steel flow rate through the SEN based on recorded plant data. Finally the model system was applied to study the effects of stopper rod movements on SEN/mold flow patterns. Meniscus level fluctuations were calculated using a simple pressure method and compared well with plant measurements. Insights were gained from the simulation results to explain the cause of meniscus level fluctuations and the formation of sliver defects during stopper rod movements.

  20. Computer simulations for intense continuous beam transport in electrostatic lens systems

    International Nuclear Information System (INIS)

    Zhao Xiaosong; Lv Jianqin

    2008-01-01

    A code LEADS based on the Lie algebraic analysis for the continuous beam dynamics with space charge effect in beam transport has been developed. The program is used for the simulations of axial-symmetric and unsymmetrical intense continuous beam in the channels including drift spaces, electrostatic lenses and DC electrostatic accelerating tubes. In order to get the accuracy required, all elements are divided into many small segments, and the electric field in the segments is regarded as uniform field, and the dividing points are treated as thin lenses. Iteration procedures are adopted in the program to obtain self-consistent solutions. The code can be used in the designs of low energy beam transport systems, electrostatic accelerators and ion implantation machines. (authors)

  1. Large-scale derived flood frequency analysis based on continuous simulation

    Science.gov (United States)

    Dung Nguyen, Viet; Hundecha, Yeshewatesfa; Guse, Björn; Vorogushyn, Sergiy; Merz, Bruno

    2016-04-01

    There is an increasing need for spatially consistent flood risk assessments at the regional scale (several 100.000 km2), in particular in the insurance industry and for national risk reduction strategies. However, most large-scale flood risk assessments are composed of smaller-scale assessments and show spatial inconsistencies. To overcome this deficit, a large-scale flood model composed of a weather generator and catchments models was developed reflecting the spatially inherent heterogeneity. The weather generator is a multisite and multivariate stochastic model capable of generating synthetic meteorological fields (precipitation, temperature, etc.) at daily resolution for the regional scale. These fields respect the observed autocorrelation, spatial correlation and co-variance between the variables. They are used as input into catchment models. A long-term simulation of this combined system enables to derive very long discharge series at many catchment locations serving as a basic for spatially consistent flood risk estimates at the regional scale. This combined model was set up and validated for major river catchments in Germany. The weather generator was trained by 53-year observation data at 528 stations covering not only the complete Germany but also parts of France, Switzerland, Czech Republic and Australia with the aggregated spatial scale of 443,931 km2. 10.000 years of daily meteorological fields for the study area were generated. Likewise, rainfall-runoff simulations with SWIM were performed for the entire Elbe, Rhine, Weser, Donau and Ems catchments. The validation results illustrate a good performance of the combined system, as the simulated flood magnitudes and frequencies agree well with the observed flood data. Based on continuous simulation this model chain is then used to estimate flood quantiles for the whole Germany including upstream headwater catchments in neighbouring countries. This continuous large scale approach overcomes the several

  2. A long-term, continuous simulation approach for large-scale flood risk assessments

    Science.gov (United States)

    Falter, Daniela; Schröter, Kai; Viet Dung, Nguyen; Vorogushyn, Sergiy; Hundecha, Yeshewatesfa; Kreibich, Heidi; Apel, Heiko; Merz, Bruno

    2014-05-01

    The Regional Flood Model (RFM) is a process based model cascade developed for flood risk assessments of large-scale basins. RFM consists of four model parts: the rainfall-runoff model SWIM, a 1D channel routing model, a 2D hinterland inundation model and the flood loss estimation model for residential buildings FLEMOps+r. The model cascade was recently undertaken a proof-of-concept study at the Elbe catchment (Germany) to demonstrate that flood risk assessments, based on a continuous simulation approach, including rainfall-runoff, hydrodynamic and damage estimation models, are feasible for large catchments. The results of this study indicated that uncertainties are significant, especially for hydrodynamic simulations. This was basically a consequence of low data quality and disregarding dike breaches. Therefore, RFM was applied with a refined hydraulic model setup for the Elbe tributary Mulde. The study area Mulde catchment comprises about 6,000 km2 and 380 river-km. The inclusion of more reliable information on overbank cross-sections and dikes considerably improved the results. For the application of RFM for flood risk assessments, long-term climate input data is needed to drive the model chain. This model input was provided by a multi-site, multi-variate weather generator that produces sets of synthetic meteorological data reproducing the current climate statistics. The data set comprises 100 realizations of 100 years of meteorological data. With the proposed continuous simulation approach of RFM, we simulated a virtual period of 10,000 years covering the entire flood risk chain including hydrological, 1D/2D hydrodynamic and flood damage estimation models. This provided a record of around 2.000 inundation events affecting the study area with spatially detailed information on inundation depths and damage to residential buildings on a resolution of 100 m. This serves as basis for a spatially consistent, flood risk assessment for the Mulde catchment presented in

  3. Development of simulation code for FBR spent fuel dissolution with rotary drum type continuous dissolver

    International Nuclear Information System (INIS)

    Sano, Yuichi; Katsurai, Kiyomichi; Washiya, Tadahiro; Koizumi, Tsutomu; Matsumoto, Satoshi

    2011-01-01

    Japan Atomic Energy Agency (JAEA) has been studying rotary drum type continuous dissolver for FBR spent fuel dissolution. For estimating the fuel dissolution behavior under several operational conditions in this dissolver, we have been developing the simulation code, PLUM, which mainly consists of 3 modules for calculating chemical reaction, mass transfer and thermal balance in the rotary drum type continuous dissolver. Under the various conditions where dissolution experiments were carried out with the batch-wise dissolver for FBR spent fuel and with the rotary drum type continuous dissolver for UO 2 fuel, it was confirmed that the fuel dissolution behaviors calculated by the PLUM code showed good agreement with the experimental ones. Based on this result, the condition for obtaining the dissolver solution with high HM (heavy metal : U and Pu) concentration (∼500g/L), which is required for the next step, i.e. crystallization process, was also analyzed by this code and appropriate operational conditions with the rotary drum type continuous dissolver, such as feedrate, concentration and temperature of nitric acid, could be clarified. (author)

  4. Results of the Simulation and Assimilation of Doppler Wind Lidar Observations in Preparation for European Space Agency's Aeolus Mission

    Science.gov (United States)

    McCarty, Will

    2011-01-01

    With the launch of the European Space Agency's Aeolus Mission in 2013, direct spaceborne measurements of vertical wind profiles are imminent via Doppler wind lidar technology. Part of the preparedness for such missions is the development of the proper data assimilation methodology for handling such observations. Since no heritage measurements exist in space, the Joint Observing System Simulation Experiment (Joint OSSE) framework has been utilized to generate a realistic proxy dataset as a precursor to flight. These data are being used for the development of the Gridpoint Statistical Interpolation (GSI) data assimilation system utilized at a number of centers through the United States including the Global Modeling and Assimilation Office (GMAO) at NASA/Goddard Space Flight Center and at the National Centers for Environmental Prediction (NOAA/NWS/NCEP) as an activity through the Joint Center for Satellite Data Assimilation. An update of this ongoing effort will be presented, including the methodology of proxy data generation, the limitations of the proxy data, the handling of line-of-sight wind measurements within the GSI, and the impact on both analyses and forecasts with the addition of the new data type.

  5. Application of Observing System Simulation Experiments (OSSEs) to determining science and user requirements for space-based missions

    Science.gov (United States)

    Atlas, R. M.

    2016-12-01

    Observing System Simulation Experiments (OSSEs) provide an effective method for evaluating the potential impact of proposed new observing systems, as well as for evaluating trade-offs in observing system design, and in developing and assessing improved methodology for assimilating new observations. As such, OSSEs can be an important tool for determining science and user requirements, and for incorporating these requirements into the planning for future missions. Detailed OSSEs have been conducted at NASA/ GSFC and NOAA/AOML in collaboration with Simpson Weather Associates and operational data assimilation centers over the last three decades. These OSSEs determined correctly the quantitative potential for several proposed satellite observing systems to improve weather analysis and prediction prior to their launch, evaluated trade-offs in orbits, coverage and accuracy for space-based wind lidars, and were used in the development of the methodology that led to the first beneficial impacts of satellite surface winds on numerical weather prediction. In this talk, the speaker will summarize the development of OSSE methodology, early and current applications of OSSEs and how OSSEs will evolve in order to enhance mission planning.

  6. Personality factors in flight operations. Volume 1: Leader characteristics and crew performance in a full-mission air transport simulation

    Science.gov (United States)

    Chidester, Thomas R.; Kanki, Barbara G.; Foushee, H. Clayton; Dickinson, Cortlandt L.; Bowles, Stephen V.

    1990-01-01

    Crew effectiveness is a joint product of the piloting skills, attitudes, and personality characteristics of team members. As obvious as this point might seem, both traditional approaches to optimizing crew performance and more recent training development highlighting crew coordination have emphasized only the skill and attitudinal dimensions. This volume is the first in a series of papers on this simulation. A subsequent volume will focus on patterns of communication within crews. The results of a full-mission simulation research study assessing the impact of individual personality on crew performance is reported. Using a selection algorithm described in previous research, captains were classified as fitting one of three profiles along a battery of personality assessment scales. The performances of 23 crews led by captains fitting each profile were contrasted over a one-and-one-half-day simulated trip. Crews led by captains fitting a positive Instrumental-Expressive profile (high achievement motivation and interpersonal skill) were consistently effective and made fewer errors. Crews led by captains fitting a Negative Expressive profile (below average achievement motivation, negative expressive style, such as complaining) were consistently less effective and made more errors. Crews led by captains fitting a Negative Instrumental profile (high levels of competitiveness, verbal aggressiveness, and impatience and irritability) were less effective on the first day but equal to the best on the second day. These results underscore the importance of stable personality variables as predictors of team coordination and performance.

  7. Body composition and metabolic changes during a 520-day mission simulation to Mars.

    Science.gov (United States)

    Strollo, F; Macchi, C; Eberini, I; Masini, M A; Botta, M; Vassilieva, G; Nichiporuk, I; Monici, M; Santucci, D; Celotti, F; Magni, P; Ruscica, M

    2018-03-12

    The "Mars-500 project" allowed to evaluate the changes in psychological/physiological adaptation over a prolonged confinement, in order to gather information for future missions. Here, we evaluated the impact of confinement and isolation on body composition, glucose metabolism/insulin resistance and adipokine levels. The "Mars-500 project" consisted of 520 consecutive days of confinement from June 3, 2010 to Nov 4, 2011. The crew was composed of six male subjects (three Russians, two Europeans, and one Chinese) with a median age of 31 years (range 27-38 years). During the 520-day confinement, total body mass and BMI progressively decreased, reaching a significant difference at the end (417 days) of the observation period (- 9.2 and - 5.5%, respectively). Fat mass remained unchanged. A progressive and significant increase of fasting plasma glucose was observed between 249 and 417 days (+ 10/+ 17% vs baseline), with a further increase at the end of confinement (up to + 30%). Median plasma insulin showed a non-significant early increment (60 days; + 86%). Total adiponectin halved (- 47%) 60 days after hatch closure, remaining at this nadir (- 51%) level for a further 60 days. High molecular weight adiponectin remained significantly lower from 60 to 168 days. Based on these data, countermeasures may be envisioned to balance the potentially harmful effects of prolonged confinement, including a better exercise program, with accurate monitoring of (1) the individual activity and (2) the relationship between body composition and metabolic derangement.

  8. Comparing a Dynamic Fed-Batch and a Continuous Steady-State Simulation of Ethanol Fermentation in a Distillery to a Stoichiometric Conversion Simulation

    OpenAIRE

    Fonseca, G.C.; Costa, C.B.B.; Cruz, A.J.G.

    2017-01-01

    Abstract An autonomous sugarcane bioethanol plant was simulated in EMSO software, an equation oriented process simulator. Three types of fermentation units were simulated: a six parallel fed-batch reactor system, a set of four CSTR in steady state and one consisting of a single stoichiometric reactor. Stoichiometric models are less accurate than kinetic-based fermentation models used for fed-batch and continuous fermenter simulations, since they do not account for inhibition effects and depen...

  9. Comparison of nasal continuous positive airway pressure delivered by seven ventilators using simulated neonatal breathing.

    Science.gov (United States)

    Drevhammar, Thomas; Nilsson, Kjell; Zetterström, Henrik; Jonsson, Baldvin

    2013-05-01

    Nasal continuous positive airway pressure (NCPAP) is an established treatment for respiratory distress in neonates. Most modern ventilators are able to provide NCPAP. There have been no large studies examining the properties of NCPAP delivered by ventilators. The aim of this study was to compare pressure stability and imposed work of breathing (iWOB) for NCPAP delivered by ventilators using simulated neonatal breathing. Experimental in vitro study. Research laboratory in Sweden. None. Neonatal breathing was simulated using a mechanical lung simulator. Seven ventilators were tested at different CPAP levels using two breath profiles. Pressure stability and iWOB were determined. Results from three ventilators revealed that they provided a slight pressure support. For these ventilators, iWOB could not be calculated. There were large differences in pressure stability and iWOB between the tested ventilators. For simulations using the 3.4-kg breath profile, the pressure swings around the mean pressure were more than five times greater, and iWOB more than four times higher, for the system with the highest measured values compared with the system with the lowest. Overall, the Fabian ventilator was the most pressure stable system. Evita XL and SERVO-i were found more pressure stable than Fabian in some simulations. The results for iWOB were in accordance with pressure stability for systems that allowed determination of this variable. Some of the tested ventilators unexpectedly provided a minor degree of pressure support. In terms of pressure stability, we have not found any advantages of ventilators as a group compared with Bubble CPAP, Neopuff, and variable flow generators that were tested in our previous study. The variation between individual systems is great within both categories. The clinical importance of these findings needs further investigation.

  10. Simulation models: a current indispensable tool in studies of the continuous water-soil-plant - atmosphere

    International Nuclear Information System (INIS)

    Lopez Seijas, Teresa; Gonzalez, Felicita; Cid, G.; Osorio, Maria de los A.; Ruiz, Maria Elena

    2008-01-01

    Full text: This work assesses the current use of simulation models as a tool useful and indispensable for the advancement in the research and study of the processes related to the continuous water-soil - plant-atmosphere. In recent years they have reported in the literature many jobs where these modeling tools are used as a support to the decision-making process of companies or organizations in the agricultural sphere and in Special for the design of optimal management of irrigation and fertilization strategies of the crops. Summarizes some of the latest applications reported with respect to the use of water transfers and solutes, such simulation models mainly to nitrate leaching and groundwater contamination problems. On the other hand also summarizes important applications of simulation models of growth of cultivation for the prediction of effects on the performance of different conditions of water stress, and finally some other applications on the management of the different irrigation technologies as kingpins, superfiail irrigation and drip irrigation. Refer also the main work carried out in Cuba. (author)

  11. Dynamical Downscaling of NASA/GISS ModelE: Continuous, Multi-Year WRF Simulations

    Science.gov (United States)

    Otte, T.; Bowden, J. H.; Nolte, C. G.; Otte, M. J.; Herwehe, J. A.; Faluvegi, G.; Shindell, D. T.

    2010-12-01

    The WRF Model is being used at the U.S. EPA for dynamical downscaling of the NASA/GISS ModelE fields to assess regional impacts of climate change in the United States. The WRF model has been successfully linked to the ModelE fields in their raw hybrid vertical coordinate, and continuous, multi-year WRF downscaling simulations have been performed. WRF will be used to downscale decadal time slices of ModelE for recent past, current, and future climate as the simulations being conducted for the IPCC Fifth Assessment Report become available. This presentation will focus on the sensitivity to interior nudging within the RCM. The use of interior nudging for downscaled regional climate simulations has been somewhat controversial over the past several years but has been recently attracting attention. Several recent studies that have used reanalysis (i.e., verifiable) fields as a proxy for GCM input have shown that interior nudging can be beneficial toward achieving the desired downscaled fields. In this study, the value of nudging will be shown using fields from ModelE that are downscaled using WRF. Several different methods of nudging are explored, and it will be shown that the method of nudging and the choices made with respect to how nudging is used in WRF are critical to balance the constraint of ModelE against the freedom of WRF to develop its own fields.

  12. Numerical methods for the simulation of continuous sedimentation in ideal clarifier-thickener units

    Energy Technology Data Exchange (ETDEWEB)

    Buerger, R.; Karlsen, K.H.; Risebro, N.H.; Towers, J.D.

    2001-10-01

    We consider a model of continuous sedimentation. Under idealizing assumptions, the settling of the solid particles under the influence of gravity can be described by the initial value problem for a nonlinear hyperbolic partial differential equation with a flux function that depends discontinuously on height. The purpose of this contribution is to present and demonstrate two numerical methods for simulating continuous sedimentation: a front tracking method and a finite finite difference method. The basic building blocks in the front tracking method are the solutions of a finite number of certain Riemann problems and a procedure for tracking local collisions of shocks. The solutions of the Riemann problems are recalled herein and the front tracking algorithm is described. As an alternative to the front tracking method, a simple scalar finite difference algorithm is proposed. This method is based on discretizing the spatially varying flux parameters on a mesh that is staggered with respect to that of the conserved variable, resulting in a straightforward generalization of the well-known Engquist-Osher upwind finite difference method. The result is an easily implemented upwind shock capturing method. Numerical examples demonstrate that the front tracking and finite difference methods can be used as efficient and accurate simulation tools for continuous sedimentation. The numerical results for the finite difference method indicate that discontinuities in the local solids concentration are resolved sharply and agree with those produced by the front tracking method. The latter is free of numerical dissipation, which leads to sharply resolved concentration discontinuities, but is more complicated to implement than the former. Available mathematical results for the proposed numerical methods are also briefly reviewed. (author)

  13. Training to Operate a Simulated Micro-Unmanned Aerial Vehicle With Continuous or Discrete Manual Control

    National Research Council Canada - National Science Library

    Durlach, Paula J; Neumann, John L; Billings, Deborah R

    2008-01-01

    .... They were then given training missions during which performance was measured. Eight conditions were investigated, formed by crossing three 2-level factors: input device (mouse vs. game controller...

  14. Brownian dynamics simulations of a flexible polymer chain which includes continuous resistance and multibody hydrodynamic interactions

    Science.gov (United States)

    Butler, Jason E.; Shaqfeh, Eric S. G.

    2005-01-01

    Using methods adapted from the simulation of suspension dynamics, we have developed a Brownian dynamics algorithm with multibody hydrodynamic interactions for simulating the dynamics of polymer molecules. The polymer molecule is modeled as a chain composed of a series of inextensible, rigid rods with constraints at each joint to ensure continuity of the chain. The linear and rotational velocities of each segment of the polymer chain are described by the slender-body theory of Batchelor [J. Fluid Mech. 44, 419 (1970)]. To include hydrodynamic interactions between the segments of the chain, the line distribution of forces on each segment is approximated by making a Legendre polynomial expansion of the disturbance velocity on the segment, where the first two terms of the expansion are retained in the calculation. Thus, the resulting linear force distribution is specified by a center of mass force, couple, and stresslet on each segment. This method for calculating the hydrodynamic interactions has been successfully used to simulate the dynamics of noncolloidal suspensions of rigid fibers [O. G. Harlen, R. R. Sundararajakumar, and D. L. Koch, J. Fluid Mech. 388, 355 (1999); J. E. Butler and E. S. G. Shaqfeh, J. Fluid Mech. 468, 204 (2002)]. The longest relaxation time and center of mass diffusivity are among the quantities calculated with the simulation technique. Comparisons are made for different levels of approximation of the hydrodynamic interactions, including multibody interactions, two-body interactions, and the "freely draining" case with no interactions. For the short polymer chains studied in this paper, the results indicate a difference in the apparent scaling of diffusivity with polymer length for the multibody versus two-body level of approximation for the hydrodynamic interactions.

  15. Evaluation of IEEE 802.11g and 802.16 for Lunar Surface Exploration Missions Using MACHETE Simulations

    Science.gov (United States)

    Segui, John; Jennings, Esther; Vyas, Hemali

    2009-01-01

    In this paper, we investigated the suitability of terrestrial wireless networking technologies for lunar surface exploration missions. Specifically, the scenario we considered consisted of two teams of collaborating astronauts, one base station and one rover, where the base station and the rover have the capability of acting as relays. We focused on the evaluation of IEEE 802.11g and IEEE 802.16 protocols, simulating homogeneous 802.11g network, homogeneous 802.16 network, and heterogeneous network using both 802.11g and 802.16. A mix of traffic flows were simulated, including telemetry, caution and warning, voice, command and file transfer. Each traffic type had its own distribution profile, data volume, and priority. We analyzed the loss and delay trade-offs of these wireless protocols with various link-layer options. We observed that 802.16 network managed the channel better than an 802.11g network due to controlled infrastructure and centralized scheduling. However, due to the centralized scheduling, 802.16 also had a longer delay. The heterogeneous (hybrid) of 802.11/802.16 achieved a better balance of performance in terms of data loss and delay compared to using 802.11 or 802.16 alone.

  16. Heavy vehicle simulator (HVS) evaluation of load transfer efficiency and continuously reinforced concrete inlays on the N3 near Pietermartizburg

    CSIR Research Space (South Africa)

    Du Plessis, L

    2006-07-01

    Full Text Available The paper addresses two different heavy Vehicle Simulator (HVS) studies conducted on concrete: Load transfer through aggregate interlock and the use of dowels and the evaluation of the performance of an in-service continuously reinforced concrete...

  17. Gradient simulation experiments for targeting population heterogeneity in continuous Saccharomyces cerevisiae fermentation

    DEFF Research Database (Denmark)

    Heins, Anna-Lena; Lencastre Fernandes, Rita; Lundin, L.

    Traditionally, a microbial population has been considered homogeneous in optimization studies of fermentation processes. However, research has shown that a typical microbial population in a fermenter is heterogeneous. There are indications that such heterogeneity may be both beneficial (facilitates...... quick adaptation to new conditions) and harmful (reduces yields and productivities) (Bylund et al. (1998); Enfors et al. (2001)). Significant gradients of e.g. dissolved oxygen, substrates, and pH are typically observed in many industrial scale fermentation processes. Consequently, the microbial cells...... reporter strain demonstrated a highly dynamic behaviour with regards to subpopulation distribution during the different growth stages. To simulate which effect glucose gradients, often seen in large scale cultivations, have on population heterogeneity, glucose perturbations during continuous cultivation...

  18. Calculation and simulation on mid-spatial frequency error in continuous polishing

    International Nuclear Information System (INIS)

    Xie Lei; Zhang Yunfan; You Yunfeng; Ma Ping; Liu Yibin; Yan Dingyao

    2013-01-01

    Based on theoretical model of continuous polishing, the influence of processing parameters on the polishing result was discussed. Possible causes of mid-spatial frequency error in the process were analyzed. The simulation results demonstrated that the low spatial frequency error was mainly caused by large rotating ratio. The mid-spatial frequency error would decrease as the low spatial frequency error became lower. The regular groove shape was the primary reason of the mid-spatial frequency error. When irregular and fitful grooves were adopted, the mid-spatial frequency error could be lessened. Moreover, the workpiece swing could make the polishing process more uniform and reduce the mid-spatial frequency error caused by the fix-eccentric plane polishing. (authors)

  19. Simulations of the response function of a plasma ion beam spectrometer for the Cassini mission to Saturn

    International Nuclear Information System (INIS)

    Vilppola, J.H.; Tanskanen, P.J.; Huomo, H.; Barraclough, B.L.

    1996-01-01

    To obtain very high (∼1%) energy resolution with spherical-section electrostatic analyzers requires high precision in both fabrication and in the alignment process. In order to aid in the calibration of the instrument and to help minimize fabrication costs, we have applied simulation models to the ion beam spectrometer for the NASA/ESA Cassini mission to Saturn. Previously we studied the effects of misalignment and simple irregularities of the hemispherical surfaces on the performance of an electrostatic analyzer. We have considered a hemispherical electrostatic analyzer equipped with an aperture plate to collimate the stray electric field at the entrance apertures. The influence of a curved entrance aperture has also been added to the simulation model, and its effects have been studied in detail. A cylindrical three-dimensional simultaneous overrelaxation algorithm has been introduced to solve for the stray electric field. The maximum loss of transmitted particles with respect to the transmission of an ideal instrument has been set at 10%. We demonstrate that the deviation in the distributions of the energies is less than 0.2% and that the deviation in the distributions of entrance angles of transmitted particles is less than 0.1 degree. It has been found that the energy resolution of an electrostatic analyzer can be improved from ΔE/E=(1.6±0.2)% to ΔE/E=(1.3±0.2)% by the introduction of front aperture plates. Through the introduction of curved entrance slits, the azimuthal angle resolution has changed from β=(1.4±0.1)degree for the simplified geometry simulation results of our previous article to β=(2.3±0.1)degree. We have confirmed that an accuracy of 25 μm in the alignment of the two hemispherical surfaces is sufficient to give the instrument the desired resolutions. copyright 1996 American Institute of Physics

  20. SIMULATION OF MICROALGAL GROWTH IN A CONTINUOUS PHOTOBIOREACTOR WITH SEDIMENTATION AND PARTIAL BIOMASS RECYCLING

    Directory of Open Access Journals (Sweden)

    C. E. de Farias Silva

    Full Text Available Abstract Microalgae are considered as promising feedstocks for the third generation of biofuels. They are autotrophic organisms with high growth rate and can stock an enormous quantity of lipids (about 20 - 40% of their dried cellular weight. This work was aimed at studying the cultivation of Scenedesmus obliquus in a two-stage system composed of a photobioreactor and a settler to concentrate and partially recycle the biomass as a way to enhance the microalgae cellular productivity. It was attempted to specify by simulation and experimental data a relationship between the recycling rate, kinetic parameters of microalgal growth and photobioreactor operating conditions. Scenedesmus obliquus cells were cultivated in a lab-scale flat-plate reactor, homogenized by aeration, and running in continuous flow with a residence time of 1.66 day. Experimental data for the microalgal growth were used in a semi-empirical simulation model. The best results were obtained for Fw=0.2FI, when R = 1 and kd = 0 and 0.05 day-1, with the biomass production in the reactor varying between 8 g L -1 and 14 g L-1, respectively. The mathematical model fitted to the microalgal growth experimental data was appropriate for predicting the efficiency of the reactor in producing Scenedesmus obliquus cells, establishing a relation between cellular productivity and the minimum recycling rate that must be used in the system.

  1. Pseudo-transient Continuation Based Variable Relaxation Solve in Nonlinear Magnetohydrodynamic Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Jin Chen

    2009-12-07

    Efficient and robust Variable Relaxation Solver, based on pseudo-transient continuation, is developed to solve nonlinear anisotropic thermal conduction arising from fusion plasma simulations. By adding first and/or second order artificial time derivatives to the system, this type of method advances the resulting time-dependent nonlinear PDEs to steady state, which is the solution to be sought. In this process, only the stiffness matrix itself is involved so that the numerical complexity and errors can be greatly reduced. In fact, this work is an extension of integrating efficient linear elliptic solvers for fusion simulation on Cray XIE. Two schemes are derived in this work, first and second order Variable Relaxations. Four factors are observed to be critical for efficiency and preservation of solution's symmetric structure arising from periodic boundary condition: refining meshes in different coordinate directions, initializing nonlinear process, varying time steps in both temporal and spatial directions, and accurately generating nonlinear stiffness matrix. First finer mesh scale should be taken in strong transport direction; Next the system is carefully initialized by the solution with linear conductivity; Third, time step and relaxation factor are vertex-based varied and optimized at each time step; Finally, the nonlinear stiffness matrix is updated by just scaling corresponding linear one with the vector generated from nonlinear thermal conductivity.

  2. Continuous surface force based lattice Boltzmann equation method for simulating thermocapillary flow

    International Nuclear Information System (INIS)

    Zheng, Lin; Zheng, Song; Zhai, Qinglan

    2016-01-01

    In this paper, we extend a lattice Boltzmann equation (LBE) with continuous surface force (CSF) to simulate thermocapillary flows. The model is designed on our previous CSF LBE for athermal two phase flow, in which the interfacial tension forces and the Marangoni stresses as the results of the interface interactions between different phases are described by a conception of CSF. In this model, the sharp interfaces between different phases are separated by a narrow transition layers, and the kinetics and morphology evolution of phase separation would be characterized by an order parameter via Cahn–Hilliard equation which is solved in the frame work of LBE. The scalar convection–diffusion equation for temperature field is resolved by thermal LBE. The models are validated by thermal two layered Poiseuille flow, and two superimposed planar fluids at negligibly small Reynolds and Marangoni numbers for the thermocapillary driven convection, which have analytical solutions for the velocity and temperature. Then thermocapillary migration of two/three dimensional deformable droplet are simulated. Numerical results show that the predictions of present LBE agreed with the analytical solution/other numerical results. - Highlights: • A CSF LBE to thermocapillary flows. • Thermal layered Poiseuille flows. • Thermocapillary migration.

  3. Large Eddy Simulation of Transient Flow, Solidification, and Particle Transport Processes in Continuous-Casting Mold

    Science.gov (United States)

    Liu, Zhongqiu; Li, Linmin; Li, Baokuan; Jiang, Maofa

    2014-07-01

    The current study developed a coupled computational model to simulate the transient fluid flow, solidification, and particle transport processes in a slab continuous-casting mold. Transient flow of molten steel in the mold is calculated using the large eddy simulation. An enthalpy-porosity approach is used for the analysis of solidification processes. The transport of bubble and non-metallic inclusion inside the liquid pool is calculated using the Lagrangian approach based on the transient flow field. A criterion of particle entrapment in the solidified shell is developed using the user-defined functions of FLUENT software (ANSYS, Inc., Canonsburg, PA). The predicted results of this model are compared with the measurements of the ultrasonic testing of the rolled steel plates and the water model experiments. The transient asymmetrical flow pattern inside the liquid pool exhibits quite satisfactory agreement with the corresponding measurements. The predicted complex instantaneous velocity field is composed of various small recirculation zones and multiple vortices. The transport of particles inside the liquid pool and the entrapment of particles in the solidified shell are not symmetric. The Magnus force can reduce the entrapment ratio of particles in the solidified shell, especially for smaller particles, but the effect is not obvious. The Marangoni force can play an important role in controlling the motion of particles, which increases the entrapment ratio of particles in the solidified shell obviously.

  4. Vertical drying of a suspension of sticks: Monte Carlo simulation for continuous two-dimensional problem

    Science.gov (United States)

    Lebovka, Nikolai I.; Tarasevich, Yuri Yu.; Vygornitskii, Nikolai V.

    2018-02-01

    The vertical drying of a two-dimensional colloidal film containing zero-thickness sticks (lines) was studied by means of kinetic Monte Carlo (MC) simulations. The continuous two-dimensional problem for both the positions and orientations was considered. The initial state before drying was produced using a model of random sequential adsorption with isotropic orientations of the sticks. During the evaporation, an upper interface falls with a linear velocity in the vertical direction, and the sticks undergo translational and rotational Brownian motions. The MC simulations were run at different initial number concentrations (the numbers of sticks per unit area), pi, and solvent evaporation rates, u . For completely dried films, the spatial distributions of the sticks, the order parameters, and the electrical conductivities of the films in both the horizontal, x , and vertical, y , directions were examined. Significant evaporation-driven self-assembly and stratification of the sticks in the vertical direction was observed. The extent of stratification increased with increasing values of u . The anisotropy of the electrical conductivity of the film can be finely regulated by changes in the values of pi and u .

  5. Continuous surface force based lattice Boltzmann equation method for simulating thermocapillary flow

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Lin, E-mail: lz@njust.edu.cn [School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Zheng, Song [School of Mathematics and Statistics, Zhejiang University of Finance and Economics, Hangzhou 310018 (China); Zhai, Qinglan [School of Economics Management and Law, Chaohu University, Chaohu 238000 (China)

    2016-02-05

    In this paper, we extend a lattice Boltzmann equation (LBE) with continuous surface force (CSF) to simulate thermocapillary flows. The model is designed on our previous CSF LBE for athermal two phase flow, in which the interfacial tension forces and the Marangoni stresses as the results of the interface interactions between different phases are described by a conception of CSF. In this model, the sharp interfaces between different phases are separated by a narrow transition layers, and the kinetics and morphology evolution of phase separation would be characterized by an order parameter via Cahn–Hilliard equation which is solved in the frame work of LBE. The scalar convection–diffusion equation for temperature field is resolved by thermal LBE. The models are validated by thermal two layered Poiseuille flow, and two superimposed planar fluids at negligibly small Reynolds and Marangoni numbers for the thermocapillary driven convection, which have analytical solutions for the velocity and temperature. Then thermocapillary migration of two/three dimensional deformable droplet are simulated. Numerical results show that the predictions of present LBE agreed with the analytical solution/other numerical results. - Highlights: • A CSF LBE to thermocapillary flows. • Thermal layered Poiseuille flows. • Thermocapillary migration.

  6. Reservoir Simulation on the Cerro Prieto Geothermal Field: A Continuing Study

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda, M.; Marquez, R.; Arellano, V.; Esquer, C.A.

    1983-12-15

    The Cerro Prieto geothermal field is a liquid-dominated geothermal reservoir of complex geological and hydrological structure. It is located at the southern end of the Salton-Mexicali trough which includes other geothermal anomalies as Heber and East Mesa. Although in 1973, the initial power plant installed capacity was 75 MW of electrical power, this amount increased to 180 MW in 1981 as field development continued. It is expected to have a generating capacity of 620 MW by the end of 1985, when two new plants will be completely in operation. Questions about field deliverability, reservoir life and ultimate recovery related to planned installations are being presently asked. Numerical modeling studies can give very valuable answers to these questions, even at the early stages in the development of a field. An effort to simulate the Cerro Prieto geothermal reservoir has been undergoing for almost two years. A joint project among Comision Federal de Electricidad (CFE), Instituto de Investigaciones Electricas (IIE) and Intercomp of Houstin, Texas, was created to perform reservoir engineering and simulation studies on this field. The final project objective is tosimulate the behavior of the old field region when production from additional wells located in the undeveloped field zones will be used for feeding the new power plants.

  7. Pseudo-transient Continuation Based Variable Relaxation Solve in Nonlinear Magnetohydrodynamic Simulations

    International Nuclear Information System (INIS)

    Chen, Jin

    2009-01-01

    Efficient and robust Variable Relaxation Solver, based on pseudo-transient continuation, is developed to solve nonlinear anisotropic thermal conduction arising from fusion plasma simulations. By adding first and/or second order artificial time derivatives to the system, this type of method advances the resulting time-dependent nonlinear PDEs to steady state, which is the solution to be sought. In this process, only the stiffness matrix itself is involved so that the numerical complexity and errors can be greatly reduced. In fact, this work is an extension of integrating efficient linear elliptic solvers for fusion simulation on Cray XIE. Two schemes are derived in this work, first and second order Variable Relaxations. Four factors are observed to be critical for efficiency and preservation of solution's symmetric structure arising from periodic boundary condition: refining meshes in different coordinate directions, initializing nonlinear process, varying time steps in both temporal and spatial directions, and accurately generating nonlinear stiffness matrix. First finer mesh scale should be taken in strong transport direction; Next the system is carefully initialized by the solution with linear conductivity; Third, time step and relaxation factor are vertex-based varied and optimized at each time step; Finally, the nonlinear stiffness matrix is updated by just scaling corresponding linear one with the vector generated from nonlinear thermal conductivity.

  8. Simulated driving in obstructive sleep apnoea-hypopnoea : effects of oral appliances and continuous positive airway pressure

    NARCIS (Netherlands)

    Hoekema, Aarnoud; Stegenga, Boudewijn; Bakker, Marije; Brouwer, Wiebo H.; de Bont, Lambert G. M.; Wijkstra, Peter J.; van der Hoeven, Johannes H.

    Impaired simulated driving performance has been demonstrated in obstructive sleep apnoea-hypopnoea syndrome (OSAHS) patients. Although continuous positive airway pressure (CPAP) generally improves simulated driving performance, the effects of oral-appliance (OA) therapy are unknown. The aims of this

  9. Simulation of the chemical stage in water radiolysis with the help of Continuous Petri nets

    International Nuclear Information System (INIS)

    Barilla, J.; Lokajíček, M.V.; Pisaková, H.; Simr, P.

    2014-01-01

    The final biological effect of ionizing particles may be influenced often strongly by some chemical substances present in cells during irradiation by low-LET radiation. It may occur during the chemical stage of the given process, due to chemical reactions of radicals running in the given process. However, the whole chemical process may be hardly described sufficiently with the help of the usual approach based on the deterministic diffusion-kinetic computations and the stochastic Monte-Carlo simulations. We have proposed already earlier a model describing the processes (i.e., the combined effect of cluster diffusion and chemical reactions) running in individual radical clusters that might be responsible for corresponding damages of DNA molecules (i.e., formation of DSBs). Now a further generalization of the given model (using Continuous Petri nets) will be presented that makes it possible to characterize more detailed behavior of individual radicals in corresponding clusters, which might be useful especially for low-LET radiation when individual radical clusters meet a DNA molecule at different time intervals after their formation; the decreasing presence of individual radicals in corresponding clusters being established. In this paper we shall focus on the design of the corresponding mathematical model and its application; the comparison of corresponding results with experimental data obtained in the case of deoxygenated system will be presented. - Highlights: • Creation of the mathematical model. • Realization of the model with the help of Continuous Petri nets. • Obtain the time dependence of changes in the concentration of radicals

  10. Continuously on-­going regional climate hindcast simulations for impact applications

    Science.gov (United States)

    Anders, Ivonne; Piringer, Martin; Kaufmann, Hildegard; Knauder, Werner; Resch, Gernot; Andre, Konrad

    2017-04-01

    Observational data for e.g. temperature, precipitation, radiation, or wind are often used as meteorological forcing for different impact models, like e.g. crop models, urban models, economic models and energy system models. To assess a climate signal, the time period covered by the observation is often too short, they have gaps in between, and are inhomogeneous over time, due to changes in the measurements itself or in the near surrounding. Thus output from global and regional climate models can close the gap and provide homogeneous and physically consistent time series of meteorological parameters. CORDEX evaluation runs performed for the IPCC-AR5 provide a good base for the regional scale. However, with respect to climate services, continuously on-going hindcast simulations are required for regularly updated applications. The Climate Research group at the national Austrian weather service, ZAMG, is focusing on high mountain regions and, especially on the Alps. The hindcast-simulation performed with the regional climate model COSMO-CLM is forced by ERAinterim and optimized for the Alpine Region. The simulation available for the period of 1979-2015 in a spatial resolution of about 10km is prolonged ongoing and fullfils the customer's needs with respect of output variables, levels, intervals and statistical measures. One of the main tasks is to capture strong precipitation events which often occur during summer when low pressure systems develop over the Golf of Genoa, moving to the Northeast. This leads to floods and landslide events in Austria, Czech Republic and Germany. Such events are not sufficiently represented in the CORDEX-evaluation runs. ZAMG use high quality gridded precipitation and temperature data for the Alpine Region (1-6km) to evaluate the model performance. Data is provided e.g. to hydrological modellers (high water, low water), but also to assess icing capability of infrastructure or the calculation the separation distances between livestock

  11. Investigation of bio-regenerative life support and Trash-to-gas experiment on a 4 month mars simulation mission

    OpenAIRE

    Caraccio, A.; Poulet, Lucie; Hintze, P.; Miles, J.D.

    2014-01-01

    Future crewed missions to other planets or deep space locations will require regenerative Life Support Systems (LSS) as well as recycling processes for mission waste. Constant resupply of many commodity materials will not be a sustainable option for deep space missions, nor will stowing trash on board a vehicle or at a lunar or Martian outpost. The habitable volume will decline as the volume of waste increases. A complete regenerative environmentally controlled life support system (ECLSS) on ...

  12. The Swarm End-to-End mission simulator study: A demonstration of separating the various contributions to Earth's magnetic field using synthetic data

    DEFF Research Database (Denmark)

    Olsen, Nils; Haagmans, R.; Sabaka, T.J.

    2006-01-01

    Swarm, a satellite constellation to measure Earth's magnetic field with unpreceded accuracy, has been selected by ESA for launch in 2009. The mission will provide the best ever survey of the geomagnetic field and its temporal evolution, in order to gain new insights into the Earth system...... to the science objectives of Swarm. In order to be able to use realistic parameters of the Earth's environment, the mission simulation starts at January 1, 1997 and lasts until re-entry of the lower satellites five years later. Synthetic magnetic field values were generated for all relevant contributions...

  13. Simulated HAZ continuous cooling transformation diagram of a bogie steel of high-speed railway

    Science.gov (United States)

    Liu, Yue; Chen, Hui; Liu, Yan; Hang, Zongqiu

    2017-07-01

    Simulated HAZ continuous cooling transformation (SH-CCT) diagram presents the start and end points of phase transformation and the relationships of the microstructures of HAZ, temperature and cooling rates. It is often used to assess the weldability of materials. In this paper, a weathering steel Q345C which is widely used in the bogies manufacturing was studied. The cooling times from 800∘C to 500∘C (t8/5) were from 3 s to 6000 s, aiming to study the microstructures under different cooling rates. Different methods such as color metallography were used to obtain the metallography images. The results show that ferrite nucleates preferentially at the prior austenite grain boundaries and grows along the grain boundaries with a lath-like distribution when t8/5 is 300 s. Austenite transforms into ferrite, pearlite and bainite with decreasing t8/5. Pearlite disappears completely when t8/5 = 150 s. Martensite gradually appears when t8/5 decreases to 30 s. The hardness increases with decreasing t8/5. The SH-CCT diagram indicates that the welding input and t8/5 should be taken into consideration when welding. This work provides the relationships of welding parameters and microstructures.

  14. Comparative simulations of microjetting using atomistic and continuous approaches in the presence of viscosity and surface tension

    Science.gov (United States)

    Durand, O.; Jaouen, S.; Soulard, L.; Heuzé, O.; Colombet, L.

    2017-10-01

    We compare, at similar scales, the processes of microjetting and ejecta production from shocked roughened metal surfaces by using atomistic and continuous approaches. The atomistic approach is based on very large scale molecular dynamics (MD) simulations with systems containing up to 700 × 106 atoms. The continuous approach is based on Eulerian hydrodynamics simulations with adaptive mesh refinement; the simulations take into account the effects of viscosity and surface tension, and the equation of state is calculated from the MD simulations. The microjetting is generated by shock-loading above its fusion point a three-dimensional tin crystal with an initial sinusoidal free surface perturbation, the crystal being set in contact with a vacuum. Several samples with homothetic wavelengths and amplitudes of defect are simulated in order to investigate the influence of viscosity and surface tension of the metal. The simulations show that the hydrodynamic code reproduces with very good agreement the profiles, calculated from the MD simulations, of the ejected mass and velocity along the jet. Both codes also exhibit a similar fragmentation phenomenology of the metallic liquid sheets ejected, although the fragmentation seed is different. We show in particular, that it depends on the mesh size in the continuous approach.

  15. Comparing a Dynamic Fed-Batch and a Continuous Steady-State Simulation of Ethanol Fermentation in a Distillery to a Stoichiometric Conversion Simulation

    Directory of Open Access Journals (Sweden)

    G.C. Fonseca

    Full Text Available Abstract An autonomous sugarcane bioethanol plant was simulated in EMSO software, an equation oriented process simulator. Three types of fermentation units were simulated: a six parallel fed-batch reactor system, a set of four CSTR in steady state and one consisting of a single stoichiometric reactor. Stoichiometric models are less accurate than kinetic-based fermentation models used for fed-batch and continuous fermenter simulations, since they do not account for inhibition effects and depend on a known conversion rate of reactant to be specified instead. On the other hand, stoichiometric models are faster and simpler to converge. In this study it was found that the conversion rates of sugar for the fermentation systems analyzedwere predictable from information on the composition of the juice stream. Those rates were used in the stoichiometric model, which accurately reproduced the results from both the fed-batch and the continuous fermenter system.

  16. A computer program for estimating the power-density spectrum of advanced continuous simulation language generated time histories

    Science.gov (United States)

    Dunn, H. J.

    1981-01-01

    A computer program for performing frequency analysis of time history data is presented. The program uses circular convolution and the fast Fourier transform to calculate power density spectrum (PDS) of time history data. The program interfaces with the advanced continuous simulation language (ACSL) so that a frequency analysis may be performed on ACSL generated simulation variables. An example of the calculation of the PDS of a Van de Pol oscillator is presented.

  17. Flood frequency estimation by national-scale continuous hydrological simulations: an application in Great Britain

    Science.gov (United States)

    Formetta, Giuseppe; Stewart, Elizabeth; Bell, Victoria; Reynard, Nick

    2017-04-01

    measured floods with a correlation coefficient that ranges from 0.8 for low return periods to 0.65 for the highest. It is shown that model performance is robust and independent of catchment features such as area and mean annual rainfall. The promising results for Great Britain support the aspiration that continuous simulation from large-scale hydrological models, supported by the increasing availability of global weather, climate and hydrological products, could be used to develop robust methods to help engineers estimate design floods in regions with limited gauge data or affected by environmental change.

  18. The subsurface geology of Río Tinto: material examined during a simulated Mars drilling mission for the Mars Astrobiology Research and Technology Experiment (MARTE).

    Science.gov (United States)

    Prieto-Ballesteros, Olga; Martínez-Frías, Jesús; Schutt, John; Sutter, Brad; Heldmann, Jennifer L; Bell, Mary Sue; Battler, Melissa; Cannon, Howard; Gómez-Elvira, Javier; Stoker, Carol R

    2008-10-01

    The 2005 Mars Astrobiology Research and Technology Experiment (MARTE) project conducted a simulated 1-month Mars drilling mission in the Río Tinto district, Spain. Dry robotic drilling, core sampling, and biological and geological analytical technologies were collectively tested for the first time for potential use on Mars. Drilling and subsurface sampling and analytical technologies are being explored for Mars because the subsurface is the most likely place to find life on Mars. The objectives of this work are to describe drilling, sampling, and analytical procedures; present the geological analysis of core and borehole material; and examine lessons learned from the drilling simulation. Drilling occurred at an undisclosed location, causing the science team to rely only on mission data for geological and biological interpretations. Core and borehole imaging was used for micromorphological analysis of rock, targeting rock for biological analysis, and making decisions regarding the next day's drilling operations. Drilling reached 606 cm depth into poorly consolidated gossan that allowed only 35% of core recovery and contributed to borehole wall failure during drilling. Core material containing any indication of biology was sampled and analyzed in more detail for its confirmation. Despite the poorly consolidated nature of the subsurface gossan, dry drilling was able to retrieve useful core material for geological and biological analysis. Lessons learned from this drilling simulation can guide the development of dry drilling and subsurface geological and biological analytical technologies for future Mars drilling missions.

  19. Simulation and Experimental Study on the Steady Conduction Solution for Continuous Rheo-Casting for A356 Alloy

    International Nuclear Information System (INIS)

    Duc, Do Minh; Hai, Nguyen Hong; Quang, Pham

    2017-01-01

    Computational fluid dynamic modeling of a continuous rheo-casting technology was conducted, consistent with the manufacturing of 3 "m"m"-"t"h"i"n plates made of aluminum alloy A356. The A numerical simulation on of the stabilizing time of the material crystallization was carried out using the ANSYS FLUENT code. Solidification and melting models were simulated with heat transfer and solid-liquid phase transformation involving the latent heat of crystallization were simulated. The calculated temperature distribution and the evolution of cooling rate through the material were examined and used to clarify their influence on microstructure, and further investigated with hardness testing. The thickness of the mushy zone was determined for the steady conduction solution of the continuous rheo-casting process.

  20. Simulation and Experimental Study on the Steady Conduction Solution for Continuous Rheo-Casting for A356 Alloy

    Energy Technology Data Exchange (ETDEWEB)

    Duc, Do Minh; Hai, Nguyen Hong; Quang, Pham [Hanoi University of Science and Technology (HUST), Hanoi (Viet Nam)

    2017-03-15

    Computational fluid dynamic modeling of a continuous rheo-casting technology was conducted, consistent with the manufacturing of 3 {sup mm-thin} plates made of aluminum alloy A356. The A numerical simulation on of the stabilizing time of the material crystallization was carried out using the ANSYS FLUENT code. Solidification and melting models were simulated with heat transfer and solid-liquid phase transformation involving the latent heat of crystallization were simulated. The calculated temperature distribution and the evolution of cooling rate through the material were examined and used to clarify their influence on microstructure, and further investigated with hardness testing. The thickness of the mushy zone was determined for the steady conduction solution of the continuous rheo-casting process.

  1. Integrating Continuous-Time and Discrete-Event Concepts in Process Modelling, Simulation and Control

    NARCIS (Netherlands)

    Beek, van D.A.; Gordijn, S.H.F.; Rooda, J.E.; Ertas, A.

    1995-01-01

    Currently, modelling of systems in the process industry requires the use of different specification languages for the specification of the discrete-event and continuous-time subsystems. In this way, models are restricted to individual subsystems of either a continuous-time or discrete-event nature.

  2. Mission reliability of semi-Markov systems under generalized operational time requirements

    International Nuclear Information System (INIS)

    Wu, Xiaoyue; Hillston, Jane

    2015-01-01

    Mission reliability of a system depends on specific criteria for mission success. To evaluate the mission reliability of some mission systems that do not need to work normally for the whole mission time, two types of mission reliability for such systems are studied. The first type corresponds to the mission requirement that the system must remain operational continuously for a minimum time within the given mission time interval, while the second corresponds to the mission requirement that the total operational time of the system within the mission time window must be greater than a given value. Based on Markov renewal properties, matrix integral equations are derived for semi-Markov systems. Numerical algorithms and a simulation procedure are provided for both types of mission reliability. Two examples are used for illustration purposes. One is a one-unit repairable Markov system, and the other is a cold standby semi-Markov system consisting of two components. By the proposed approaches, the mission reliability of systems with time redundancy can be more precisely estimated to avoid possible unnecessary redundancy of system resources. - Highlights: • Two types of mission reliability under generalized requirements are defined. • Equations for both types of reliability are derived for semi-Markov systems. • Numerical methods are given for solving both types of reliability. • Simulation procedure is given for estimating both types of reliability. • Verification of the numerical methods is given by the results of simulation

  3. Simulation study on the maximum continuous working condition of a power plant boiler

    Science.gov (United States)

    Wang, Ning; Han, Jiting; Sun, Haitian; Cheng, Jiwei; Jing, Ying'ai; Li, Wenbo

    2018-05-01

    First of all, the boiler is briefly introduced to determine the mathematical model and the boundary conditions, then the boiler under the BMCR condition numerical simulation study, and then the BMCR operating temperature field analysis. According to the boiler actual test results and the hot BMCR condition boiler output test results, the simulation results are verified. The main conclusions are as follows: the position and size of the inscribed circle in the furnace and the furnace temperature distribution and test results under different elevation are compared and verified; Accuracy of numerical simulation results.

  4. Simulation assessment of continuous simulating moving bed chromatography process with partial feed and new strategy with partial feed

    Directory of Open Access Journals (Sweden)

    H. Khan

    2009-09-01

    Full Text Available Partial Feed simulating moving bed (SMB has proved to be more efficient in binary separation performance (purity, recovery, productivity because of its two additional degrees of freedom, namely feed length and feed time, as compared to classical SMB process. The binary separation of dextran T6 and fructose with linear isotherm is modeled with Aspen Chromatography simulator in a four zone SMB with one column per zone for both normal-feed and Partial Feed. Increase in number of feed length and feed time in the cycle plays a very important role in the separation performance with Partial Feed. In addition, the effect of mode of operation (early or late introduction of increase in number of feed length in the cycle on product purity and recovery is also investigated. Furthermore, the binary separation system is designed with the safety margin method and the optimum operating parameters for simulation are calculated with triangle theory. Finally, a new strategy with Partial Feed is developed, showing improved separation performance relative to the basic four-zone SMB with regard to extract stream purity and recovery. The results of the proposed study can served as a useful summary of Partial Feed operation.

  5. Parameter identification using optimization techniques in the continuous simulation programs FORSIM and MACKSIM

    International Nuclear Information System (INIS)

    Carver, M.B.; Austin, C.F.; Ross, N.E.

    1980-02-01

    This report discusses the mechanics of automated parameter identification in simulation packages, and reviews available integration and optimization algorithms and their interaction within the recently developed optimization options in the FORSIM and MACKSIM simulation packages. In the MACKSIM mass-action chemical kinetics simulation package, the form and structure of the ordinary differential equations involved is known, so the implementation of an optimizing option is relatively straightforward. FORSIM, however, is designed to integrate ordinary and partial differential equations of abritrary definition. As the form of the equations is not known in advance, the design of the optimizing option is more intricate, but the philosophy could be applied to most simulation packages. In either case, however, the invocation of the optimizing interface is simple and user-oriented. Full details for the use of the optimizing mode for each program are given; specific applications are used as examples. (O.T.)

  6. SIMULATION AS A MEANS OF ACTIVITY STREAMLINING OF CONTINUOUSLY AND DISCRETE PRODUCTION IN SPECIFIC ENTERPRISE

    Directory of Open Access Journals (Sweden)

    Martin Straka

    2014-09-01

    Full Text Available The advantage of simulation is that it works with a model of real system, so it do not influence the system straight. The provision of quality simulation is also quality model, which has almost the same parameters as the real system. The goal of the project is to create a model and to try its different states, real or hypothetic. A system analysis is used for analysing and to reach of modelled system specifications. The base of synthesis is to create the simulation model. Described simulation model is the result of these steps. Description consists of the functional principle, importance and item setup. The section of variation calculations consists of several measured states of the system. At the output of every calculation, there lies summary of defined differences, their influence of gravure printing process in the technological and the economic aspects.

  7. [Applicability of agricultural production systems simulator (APSIM) in simulating the production and water use of wheat-maize continuous cropping system in North China Plain].

    Science.gov (United States)

    Wang, Lin; Zheng, You-fei; Yu, Qiang; Wang, En-li

    2007-11-01

    The Agricultural Production Systems Simulator (APSIM) was applied to simulate the 1999-2001 field experimental data and the 2002-2003 water use data at the Yucheng Experiment Station under Chinese Ecosystem Research Network, aimed to verify the applicability of the model to the wheat-summer maize continuous cropping system in North China Plain. The results showed that the average errors of the simulations of leaf area index (LAI), biomass, and soil moisture content in 1999-2000 and 2000-2001 field experiments were 27.61%, 24.59% and 7.68%, and 32.65%, 35.95% and 10.26%, respectively, and those of LAI and biomass on the soils with high and low moisture content in 2002-2003 were 26.65% and 14.52%, and 23.91% and 27.93%, respectively. The simulations of LAI and biomass accorded well with the measured values, with the coefficients of determination being > 0.85 in 1999-2000 and 2002-2003, and 0.78 in 2000-2001, indicating that APSIM had a good applicability in modeling the crop biomass and soil moisture content in the continuous cropping system, but the simulation error of LAI was a little larger.

  8. Feasibility of scenario-based simulation training versus traditional workshops in continuing medical education: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Brendan Kerr

    2013-07-01

    Full Text Available Introduction: Although simulation-based training is increasingly used for medical education, its benefits in continuing medical education (CME are less established. This study seeks to evaluate the feasibility of incorporating simulation-based training into a CME conference and compare its effectiveness with the traditional workshop in improving knowledge and self-reported confidence. Methods: Participants (N=27 were group randomized to either a simulation-based workshop or a traditional case-based workshop. Results: Post-training, knowledge assessment score neither did increase significantly in the traditional group (d=0.13; p=0.76 nor did significantly decrease in the simulation group (d= − 0.44; p=0.19. Self-reported comfort in patient assessment parameters increased in both groups (p<0.05 in all. However, only the simulation group reported an increase in comfort in patient management (d=1.1, p=0.051 for the traditional group and d=1.3; p= 0.0003 for the simulation group. At 1 month, comfort measures in the traditional group increased consistently over time while these measures in the simulation group increased post-workshop but decreased by 1 month, suggesting that some of the effects of training with simulation may be short lived. Discussion: The use of simulation-based training was not associated with benefits in knowledge acquisition, knowledge retention, or comfort in patient assessment. It was associated with superior outcomes in comfort in patient management, but this benefit may be short-lived. Further studies are required to better define the conditions under which simulation-based training is beneficial.

  9. SimLabel: a graphical user interface to simulate continuous wave EPR spectra from site-directed spin labeling experiments.

    Science.gov (United States)

    Etienne, E; Le Breton, N; Martinho, M; Mileo, E; Belle, V

    2017-08-01

    Site-directed spin labeling (SDSL) combined with continuous wave electron paramagnetic resonance (cw EPR) spectroscopy is a powerful technique to reveal, at the residue level, structural transitions in proteins. SDSL-EPR is based on the selective grafting of a paramagnetic label on the protein under study, followed by cw EPR analysis. To extract valuable quantitative information from SDSL-EPR spectra and thus give reliable interpretation on biological system dynamics, numerical simulations of the spectra are required. Such spectral simulations can be carried out by coding in MATLAB using functions from the EasySpin toolbox. For non-expert users of MATLAB, this could be a complex task or even impede the use of such simulation tool. We developed a graphical user interface called SimLabel dedicated to run cw EPR spectra simulations particularly coming from SDSL-EPR experiments. Simlabel provides an intuitive way to visualize, simulate, and fit such cw EPR spectra. An example of SDSL-EPR spectra simulation concerning the study of an intrinsically disordered region undergoing a local induced folding is described and discussed. We believe that this new tool will help the users to rapidly obtain reliable simulated spectra and hence facilitate the interpretation of their results. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  10. Development of industry processes simulators. Part II (continuous casting); Desarrollo de simuladores para procesos industriales. Parte II (Colada continua)

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, A.; Mosqueda, A.; Sauce, V.; Morales, R.; Ramos, A.; Solario, G.

    2006-07-01

    The understanding of steel thermal behavior is very important in order to take care the quality of the products like billets and slabs due to these; this work shows the joint of a subroutine to simulate the heat transfer conditions during the continuous casting process to the model for simulating the process described by the present authors in a previous work; the result is the temperature profiles and surface temperature graphics of the steel, then they are compared with data carried out or real operating conditions. (Author). 15 refs.

  11. Simulating Large Area, High Intensity AM0 Illumination on Earth- Representative Testing at Elevated Temperatures for the BepiColombo and SolO Missions

    Science.gov (United States)

    Oberhuttinger, C.; Quabis, D.; Zimmermann, C. G.

    2014-08-01

    During both the BepiColombo and the Solar Orbiter (SolO) mission, severe environmental conditions with sun intensities up to 10.6 solar constants (SCs) resp. 12.8 SCs will be encountered. Therefore, a special cell design was developed which can withstand these environmental loads. To verify the solar cells under representative conditions, a set of specific tests is conducted. The key qualification test for these high intensity, high temperature (HIHT) missions is a combined test, which exposes a large number of cells simultaneously to the complete AM0 spectrum at the required irradiance and temperature. Such a test was set up in the VTC1.5 chamber located at ESTEC. This paper provides an overview of the challenges in designing a setup capable of achieving this HIHT simulation. The solutions that were developed will be presented. Also the performance of the setup will be illustrated by actual test results.

  12. Broadband permittivity measurements on porous planetary regoliths simulants, in relation with the Rosetta mission to 67P/C-G

    Science.gov (United States)

    Brouet, Yann; Levasseur-Regourd, Anny-Chantal; Encrenaz, Pierre; Sabouroux, Pierre; Heggy, Essam; Kofman, Wlodek; Thomas, Nick

    2015-04-01

    The Rosetta mission has successfully rendezvous comet 67P/Churyumov-Gerasimenko (hereafter 67P) last year and landed Philae module on its nucleus on 12 November it 2014. Among instruments onboard Rosetta, MIRO [1], composed of two radiometers, with receivers at 190 GHz and 563 GHz (center-band), is dedicated to the measurements of the subsurface and surface brightness temperatures. These values depend on the complex relative permittivity (hereafter permittivity) with ɛ' and ɛ'' the real and imaginary parts. The permittivity of the material depends on frequency, bulk density/porosity, composition and temperature [2]. Considering the very low bulk density of 67P nucleus (about 450 kg.m-3 [3]) and the suspected presence of a dust mantle in many areas of the nucleus [4], investigations on the permittivity of porous granular samples are needed to support the interpretation of MIRO data, as well as of other microwave experiments onboard Rosetta, e.g. CONSERT [5], a bistatic penetrating radar working at 90 MHz. We have developed a programme of permittivity measurements on porous granular samples over a frequency range from 50 MHz to 190 GHz under laboratory conditions (e.g. [6] and [7]). We present new results obtained on JSC-1A lunar soil simulant and ashes from Etna. The samples were split into several sub-samples with different size ranges covering a few to 500 μm. Bulk densities of the sub-samples were carefully measured and found to be in the 800-1400 kg.m-3 range. Sub-samples were also dried and volumetric moisture content was found to be below 0.6%. From 50 MHz to 6 GHz and at 190 GHz, the permittivity has been determined, respectively with a coaxial cell and with a quasi-optical bench mounted in transmission, both connected to a vector network analyzer. The results demonstrate the dispersive behaviours of ɛ' between 50 MHz and 190 GHz. Values of ɛ' remain within the 3.9-2.6 range for all sub-samples. At CONSERT frequency, ɛ'' is within the 0.01-0.09 range

  13. A stochastic model for neutron simulation considering the spectrum and nuclear properties with continuous dependence of energy

    International Nuclear Information System (INIS)

    Camargo, Dayana Q. de; Bodmann, Bardo E.J.; Vilhena, Marco T. de; Froehlich, Herberth B.

    2011-01-01

    In this work we developed a stochastic model to simulate neutron transport in a heterogeneous environment, considering continuous neutron spectra and the nuclear properties with its continuous dependence on energy. This model was implemented using the Monte Carlo method for the propagation of neutrons in different environments. Due to restrictions with respect to the number of neutrons that can be simulated in reasonable computational time we introduced a variable control volume together with (pseudo-) periodic boundary conditions in order to overcome this problem. This study allowed a detailed analysis of the influence of energy on the neutron population and its impact on the life cycle of neutrons. From the results, even for a simple geometrical arrangement, we can conclude that there is need to consider the energy dependence and hence defined a spectral effective multiplication factor per Monte Carlo step. (author)

  14. Vacuum Simulations in High Energy Accelerators and Distribution Properties of Continuous and Discrete Particle Motions

    CERN Document Server

    Aichinger, Ida; Kersevan, Roberto

    The underlying thesis on mathematical simulation methods in application and theory is structured into three parts. The first part sets up a mathematical model capable of predicting the performance and operation of an accelerator’s vacuum system based on analytical methods. A coupled species-balance equation system describes the distribution of the gas dynamics in an ultra-high vacuum system considering impacts of conductance limitations, beam induced effects (ion-, electron-, and photon-induced de- sorption), thermal outgassing and sticking probabilities of the chamber materials. A new solving algorithm based on sparse matrix representations, is introduced and presents a closed form solution of the equation system. The model is implemented in a Python environment, named PyVasco, and is supported by a graphical user interface to make it easy available for everyone. A sensitivity analysis, a cross-check with the Test-Particle Monte Carlo simulation program Molflow+ and a comparison of the simulation results t...

  15. Design and simulation of an activated sludge unit associated to a continuous reactor to remove heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    D`Avila, J.S.; Nascimento, R.R. [Ambientec Consultoria Ltda., Aracaju, SE (Brazil)

    1993-12-31

    A software was developed to design and simulate an activated sludge unit associated to a new technology to remove heavy metals from wastewater. In this process, a continuous high efficiency biphasic reactor operates by using particles of activated peat in conjugation with the sludge unit. The results obtained may be useful to increase the efficiency or to reduce the design and operational costs involved in a activated sludge unit. (author). 5 refs., 2 tabs.

  16. Simulation for scale-up of a confined jet mixer for continuous hydrothermal flow synthesis of nanomaterials

    OpenAIRE

    Ma, CY; Liu, JJ; Zhang, Y; Wang, XZ

    2015-01-01

    Reactor performance of confined jet mixers for continuous hydrothermal flow synthesis of nanomaterials is investigated for the purpose of scale-up from laboratory scale to pilot-plant scale. Computational fluid dynamics (CFD) models were applied to simulate hydrothermal fluid flow, mixing and heat transfer behaviours in the reactors at different volumetric scale-up ratios (up to 26 times). The distributions of flow and heat transfer variables were obtained using ANSYS Fluent with the tracer c...

  17. Design and simulation of an activated sludge unit associated to a continuous reactor to remove heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    D` Avila, J S; Nascimento, R R [Ambientec Consultoria Ltda., Aracaju, SE (Brazil)

    1994-12-31

    A software was developed to design and simulate an activated sludge unit associated to a new technology to remove heavy metals from wastewater. In this process, a continuous high efficiency biphasic reactor operates by using particles of activated peat in conjugation with the sludge unit. The results obtained may be useful to increase the efficiency or to reduce the design and operational costs involved in a activated sludge unit. (author). 5 refs., 2 tabs.

  18. IMP - INTEGRATED MISSION PROGRAM

    Science.gov (United States)

    Dauro, V. A.

    1994-01-01

    IMP is a simulation language that is used to model missions around the Earth, Moon, Mars, or other planets. It has been used to model missions for the Saturn Program, Apollo Program, Space Transportation System, Space Exploration Initiative, and Space Station Freedom. IMP allows a user to control the mission being simulated through a large event/maneuver menu. Up to three spacecraft may be used: a main, a target and an observer. The simulation may begin at liftoff, suborbital, or orbital. IMP incorporates a Fehlberg seventh order, thirteen evaluation Runge-Kutta integrator with error and step-size control to numerically integrate the equations of motion. The user may choose oblate or spherical gravity for the central body (Earth, Mars, Moon or other) while a spherical model is used for the gravity of an additional perturbing body. Sun gravity and pressure and Moon gravity effects are user-selectable. Earth/Mars atmospheric effects can be included. The optimum thrust guidance parameters are calculated automatically. Events/maneuvers may involve many velocity changes, and these velocity changes may be impulsive or of finite duration. Aerobraking to orbit is also an option. Other simulation options include line-of-sight communication guidelines, a choice of propulsion systems, a soft landing on the Earth or Mars, and rendezvous with a target vehicle. The input/output is in metric units, with the exception of thrust and weight which are in English units. Input is read from the user's input file to minimize real-time keyboard input. Output includes vehicle state, orbital and guide parameters, event and total velocity changes, and propellant usage. The main output is to the user defined print file, but during execution, part of the input/output is also displayed on the screen. An included FORTRAN program, TEKPLOT, will display plots on the VDT as well as generating a graphic file suitable for output on most laser printers. The code is double precision. IMP is written in

  19. STATE ESTIMATION IN ALCOHOLIC CONTINUOUS FERMENTATION OF ZYMOMONAS MOBILIS USING RECURSIVE BAYESIAN FILTERING: A SIMULATION APPROACH

    Directory of Open Access Journals (Sweden)

    Olga Lucia Quintero

    2008-05-01

    Full Text Available This work presents a state estimator for a continuous bioprocess. To this aim, the Non Linear Filtering theory based on the recursive application of Bayes rule and Monte Carlo techniques is used. Recursive Bayesian Filters Sampling Importance Resampling (SIR is employed, including different kinds of resampling. Generally, bio-processes have strong non-linear and non-Gaussian characteristics, and this tool becomes attractive. The estimator behavior and performance are illustrated with the continuous process of alcoholic fermentation of Zymomonas mobilis. Not too many applications with this tool have been reported in the biotechnological area.

  20. An Application of a Stochastic Semi-Continuous Simulation Method for Flood Frequency Analysis: A Case Study in Slovakia

    Science.gov (United States)

    Valent, Peter; Paquet, Emmanuel

    2017-09-01

    A reliable estimate of extreme flood characteristics has always been an active topic in hydrological research. Over the decades a large number of approaches and their modifications have been proposed and used, with various methods utilizing continuous simulation of catchment runoff, being the subject of the most intensive research in the last decade. In this paper a new and promising stochastic semi-continuous method is used to estimate extreme discharges in two mountainous Slovak catchments of the rivers Váh and Hron, in which snow-melt processes need to be taken into account. The SCHADEX method used, couples a precipitation probabilistic model with a rainfall-runoff model used to both continuously simulate catchment hydrological conditions and to transform generated synthetic rainfall events into corresponding discharges. The stochastic nature of the method means that a wide range of synthetic rainfall events were simulated on various historical catchment conditions, taking into account not only the saturation of soil, but also the amount of snow accumulated in the catchment. The results showed that the SCHADEX extreme discharge estimates with return periods of up to 100 years were comparable to those estimated by statistical approaches. In addition, two reconstructed historical floods with corresponding return periods of 100 and 1000 years were compared to the SCHADEX estimates. The results confirmed the usability of the method for estimating design discharges with a recurrence interval of more than 100 years and its applicability in Slovak conditions.

  1. Study of individual and group affective processes in the crew of a simulated mission to Mars: Positive affectivity as a valuable indicator of changes in the crew affectivity

    Science.gov (United States)

    Poláčková Šolcová, Iva; Lačev, Alek; Šolcová, Iva

    2014-07-01

    The success of a long-duration space mission depends on various technical demands as well as on the psychological (cognitive, affective, and motivational) adaptation of crewmembers and the quality of interactions within the crew. We examined the ways crewmembers of a 520-day simulated spaceflight to Mars (held in the Institute for Biomedical Problems, in Moscow) experienced and regulated their moods and emotions. Results show that crewmembers experienced predominantly positive emotions throughout their 520-day isolation and the changes in mood of the crewmembers were asynchronous and balanced. The study suggests that during the simulation, crewmembers experienced and regulated their emotions differently than they usually do in their everyday life. In isolation, crewmembers preferred to suppress and neutralize their negative emotions and express overtly only emotions with positive valence. Although the affective processes were almost invariable throughout the simulation, two periods of time when the level of positive emotions declined were identified. Regarding the findings, the paper suggests that changes in positive affectivity could be a more valuable indicator of human experience in demanding but professional environments than changes in negative affectivity. Finally, the paper discusses the phenomenology of emotions during a real space mission.

  2. CFD-simulations of a 4π-continuous-mode dilution refrigerator for the CB-ELSA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bornstein, Marcel; Dutz, Hartmut; Goertz, Stefan; Reeve, Scott; Runkel, Stefan [Physikalisches Institut, Bonn Univ. (Germany); Collaboration: CBELSA/TAPS-Collaboration

    2016-07-01

    The polarized target group at Bonn operates a dilution refrigerator for double polarization experiments at the Crystal Barrel in Bonn. To get high target polarizations and long relaxation times low temperatures are indispensable. To reach temperatures below 30 mK and to allow for the use of an internal polarization magnet, the polarized target group is building a new continuous mode dilution refrigerator. As a optimizing tool for the construction of dilution refrigerators and for a better understanding of the different incoming and outgoing fluid streams several Computational Fluid Dynamic simulations are done. The heat exchange between the different streams of the refrigerator were simulated for the precooling stages within one simulation including a submesh for each fluid and solid. This leads to a better estimation of the flow characteristics and the operational parameter of the refrigerator. The last steps of construction and the preparation of the refrigerator for first test measurements are ongoing.

  3. Pseudo hard-sphere potential for use in continuous molecular-dynamics simulation of spherical and chain molecules.

    Science.gov (United States)

    Jover, J; Haslam, A J; Galindo, A; Jackson, G; Müller, E A

    2012-10-14

    We present a continuous pseudo-hard-sphere potential based on a cut-and-shifted Mie (generalized Lennard-Jones) potential with exponents (50, 49). Using this potential one can mimic the volumetric, structural, and dynamic properties of the discontinuous hard-sphere potential over the whole fluid range. The continuous pseudo potential has the advantage that it may be incorporated directly into off-the-shelf molecular-dynamics code, allowing the user to capitalise on existing hardware and software advances. Simulation results for the compressibility factor of the fluid and solid phases of our pseudo hard spheres are presented and compared both to the Carnahan-Starling equation of state of the fluid and published data, the differences being indistinguishable within simulation uncertainty. The specific form of the potential is employed to simulate flexible chains formed from these pseudo hard spheres at contact (pearl-necklace model) for m(c) = 4, 5, 7, 8, 16, 20, 100, 201, and 500 monomer segments. The compressibility factor of the chains per unit of monomer, m(c), approaches a limiting value at reasonably small values, m(c) theory. Simulation results are also presented for highly asymmetric mixtures of pseudo hard spheres, with diameter ratios of 3:1, 5:1, 20:1 over the whole composition range.

  4. Simulation model for the Boeing 720B aircraft-flight control system in continuous flight.

    Science.gov (United States)

    1971-08-01

    A mathematical model of the Boeing 720B aircraft and autopilot has been derived. The model is representative of the 720B aircraft for continuous flight within a flight envelope defined by a Mach number of .4 at 20,000 feet altitude in a cruise config...

  5. Continuous daily hydrograph simulation using duration curves of a precipitation index

    CSIR Research Space (South Africa)

    Smakhtin, VY

    2000-04-01

    Full Text Available precipitation index reflects the current catchment wetness and is defined as a continuous function of precipitation, which accumulates on rainy days and exponentially decays during the periods of no rainfall. The process of rainfall-to-runoff conversion is based...

  6. The CO_2 emission permits market simulation using Continuous Double Auction

    International Nuclear Information System (INIS)

    Bartoszczuk, Pawel; Stanczak, Jaroslaw

    2016-01-01

    In this paper we consider the buying and selling prices of carbon dioxide (CO_2) emission permits in trading models with uncertainty. Permission prices, although usually omitted from standard models, may significantly influence the trading market. We thus construct a more realistic trade model. To do this, we introduced several important changes to the standard model, mainly we added The Continuous Double Action.

  7. Development and evaluation of a simulation-based continuing medical education course: beyond lectures and credit hours.

    Science.gov (United States)

    Pugh, Carla M; Arafat, Fahd O; Kwan, Calvin; Cohen, Elaine R; Kurashima, Yo; Vassiliou, Melina C; Fried, Gerald M

    2015-10-01

    The aim of our study was to modify our previously developed laparoscopic ventral hernia (LVH) simulator to increase difficulty and then reassess validity and feasibility for using the simulator in a newly developed simulation-based continuing medical education course. Participants (N = 30) were practicing surgeons who signed up for a hands-on postgraduate laparoscopic hernia course. An LVH simulator, with prior validity evidence, was modified for the course to increase difficulty. Participants completed 1 of the 3 variations in hernia anatomy: incarcerated omentum, incarcerated bowel, and diffuse adhesions. During the procedure, course faculty and peer observers rated surgeon performance using Global Operative Assessment of Laparoscopic Skills-Incisional Hernia and Global Operative Assessment of Laparoscopic Skills rating scales with prior validity evidence. Rating scale reliability was reassessed for internal consistency. Peer and faculty raters' scores were compared. In addition, quality and completeness of the hernia repairs were rated. Internal consistency on the general skills performance (peer α = .96, faculty α = .94) and procedure-specific performance (peer α = .91, faculty α = .88) scores were high. Peers were more lenient than faculty raters on all LVH items in both the procedure-specific skills and general skills ratings. Overall, participants scored poorly on the quality and completeness of their hernia repairs (mean = 3.90/16, standard deviation = 2.72), suggesting a mismatch between course attendees and hernia difficulty and identifying a learning need. Simulation-based continuing medical education courses provide hands-on experiences that can positively affect clinical practice. Although our data appear to show a significant mismatch between clinical skill and simulator difficulty, these findings also underscore significant learning needs in the surgical community. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. A mathematical approach for evaluating Markov models in continuous time without discrete-event simulation.

    Science.gov (United States)

    van Rosmalen, Joost; Toy, Mehlika; O'Mahony, James F

    2013-08-01

    Markov models are a simple and powerful tool for analyzing the health and economic effects of health care interventions. These models are usually evaluated in discrete time using cohort analysis. The use of discrete time assumes that changes in health states occur only at the end of a cycle period. Discrete-time Markov models only approximate the process of disease progression, as clinical events typically occur in continuous time. The approximation can yield biased cost-effectiveness estimates for Markov models with long cycle periods and if no half-cycle correction is made. The purpose of this article is to present an overview of methods for evaluating Markov models in continuous time. These methods use mathematical results from stochastic process theory and control theory. The methods are illustrated using an applied example on the cost-effectiveness of antiviral therapy for chronic hepatitis B. The main result is a mathematical solution for the expected time spent in each state in a continuous-time Markov model. It is shown how this solution can account for age-dependent transition rates and discounting of costs and health effects, and how the concept of tunnel states can be used to account for transition rates that depend on the time spent in a state. The applied example shows that the continuous-time model yields more accurate results than the discrete-time model but does not require much computation time and is easily implemented. In conclusion, continuous-time Markov models are a feasible alternative to cohort analysis and can offer several theoretical and practical advantages.

  9. On-Line Optimizing Control of a Simulated Continuous Yeast Fermentation

    DEFF Research Database (Denmark)

    Andersen, Maria Y.; Asferg, L.; Brabrand, H.

    1989-01-01

    On-line optimizing control of a simulated fermentation is investigated using a non-segregated dynamic model of aerobic glucose limited growth of saccharomyces cerevisiae. The optimization procedure is carried out with an underlying adaptive regulator to stabilize the culture. This stabilization...... is especially important during the setpoint changes specified by the optimizing routine. A linear ARMAX model structure is used for the fermentation process with dilution rate as input and biomass as output variable. The parameters of the linear model structure are estimated using a pseudo linear regression...... method with bandpass filtering of in- and output variables in order to ensure low frequency validity of the estimated model. An LQ-regulator is used with iterative solution of the Riccati equation. Simulation results illustrate the tuning of the underlying regulator, and the effect of perturbing...

  10. Can we continue to ignore gender differences in performance on simulation trainers?

    Science.gov (United States)

    Thorson, Chad M; Kelly, Jason P; Forse, R Armour; Turaga, Kiran K

    2011-05-01

    There are differences between the genders in their innate performances on simulation trainers, which may impair accurate assessment of psychomotor skills. The performance of fourth-year students with no exposure to the Minimally Invasive Surgical Trainer compared based on gender, and other psychomotor skills. Our study included 16 male and 16 female students. After adjusting for choice of medical specialty (Pvideo game use (P=.6), and experience in the operating room (P=.4), female sex was an independent factor for worse performance (P=.04) in multivariate models. Women took more time than men (P<.01) and made more errors (29 versus 25 on 3 reps, P<.01). Among medical students with no previous exposure to laparoscopic trainers, female students perform worse than male students after adjusting for confounding factors. This difference must be recognized by training programs while using simulators for training and evaluation.

  11. Continuous limit of a crowd motion and herding model: Analysis and numerical simulations

    KAUST Repository

    Pietschmann, Jan-Frederik

    2011-11-01

    In this paper we study the continuum limit of a cellular automaton model used for simulating human crowds with herding behaviour. We derive a system of non-linear partial differential equations resembling the Keller-Segel model for chemotaxis, however with a non-monotone interaction. The latter has interesting consequences on the behaviour of the model\\'s solutions, which we highlight in its analysis. In particular we study the possibility of stationary states, the formation of clusters and explore their connection to congestion. We also introduce an efficient numerical simulation approach based on an appropriate hybrid discontinuous Galerkin method, which in particular allows flexible treatment of complicated geometries. Extensive numerical studies also provide a better understanding of the strengths and shortcomings of the herding model, in particular we examine trapping effects of crowds behind nonconvex obstacles. © American Institute of Mathematical Sciences.

  12. Continuous limit of a crowd motion and herding model: Analysis and numerical simulations

    KAUST Repository

    Pietschmann, Jan-Frederik; Markowich, Peter Alexander; Burger, Martin

    2011-01-01

    In this paper we study the continuum limit of a cellular automaton model used for simulating human crowds with herding behaviour. We derive a system of non-linear partial differential equations resembling the Keller-Segel model for chemotaxis, however with a non-monotone interaction. The latter has interesting consequences on the behaviour of the model's solutions, which we highlight in its analysis. In particular we study the possibility of stationary states, the formation of clusters and explore their connection to congestion. We also introduce an efficient numerical simulation approach based on an appropriate hybrid discontinuous Galerkin method, which in particular allows flexible treatment of complicated geometries. Extensive numerical studies also provide a better understanding of the strengths and shortcomings of the herding model, in particular we examine trapping effects of crowds behind nonconvex obstacles. © American Institute of Mathematical Sciences.

  13. Blue Energy and Desalination with Nanoporous Carbon Electrodes: Capacitance from Molecular Simulations to Continuous Models

    Directory of Open Access Journals (Sweden)

    Michele Simoncelli

    2018-04-01

    Full Text Available Capacitive mixing (CapMix and capacitive deionization (CDI are currently developed as alternatives to membrane-based processes to harvest blue energy—from salinity gradients between river and sea water—and to desalinate water—using charge-discharge cycles of capacitors. Nanoporous electrodes increase the contact area with the electrolyte and hence, in principle, also the performance of the process. However, models to design and optimize devices should be used with caution when the size of the pores becomes comparable to that of ions and water molecules. Here, we address this issue by simulating realistic capacitors based on aqueous electrolytes and nanoporous carbide-derived carbon (CDC electrodes, accounting for both their complex structure and their polarization by the electrolyte under applied voltage. We compute the capacitance for two salt concentrations and validate our simulations by comparison with cyclic voltammetry experiments. We discuss the predictions of Debye-Hückel and Poisson-Boltzmann theories, as well as modified Donnan models, and we show that the latter can be parametrized using the molecular simulation results at high concentration. This then allows us to extrapolate the capacitance and salt adsorption capacity at lower concentrations, which cannot be simulated, finding a reasonable agreement with the experimental capacitance. We analyze the solvation of ions and their confinement within the electrodes—microscopic properties that are much more difficult to obtain experimentally than the electrochemical response but very important to understand the mechanisms at play. We finally discuss the implications of our findings for CapMix and CDI, both from the modeling point of view and from the use of CDCs in these contexts.

  14. Blue Energy and Desalination with Nanoporous Carbon Electrodes: Capacitance from Molecular Simulations to Continuous Models

    Science.gov (United States)

    Simoncelli, Michele; Ganfoud, Nidhal; Sene, Assane; Haefele, Matthieu; Daffos, Barbara; Taberna, Pierre-Louis; Salanne, Mathieu; Simon, Patrice; Rotenberg, Benjamin

    2018-04-01

    Capacitive mixing (CapMix) and capacitive deionization (CDI) are currently developed as alternatives to membrane-based processes to harvest blue energy—from salinity gradients between river and sea water—and to desalinate water—using charge-discharge cycles of capacitors. Nanoporous electrodes increase the contact area with the electrolyte and hence, in principle, also the performance of the process. However, models to design and optimize devices should be used with caution when the size of the pores becomes comparable to that of ions and water molecules. Here, we address this issue by simulating realistic capacitors based on aqueous electrolytes and nanoporous carbide-derived carbon (CDC) electrodes, accounting for both their complex structure and their polarization by the electrolyte under applied voltage. We compute the capacitance for two salt concentrations and validate our simulations by comparison with cyclic voltammetry experiments. We discuss the predictions of Debye-Hückel and Poisson-Boltzmann theories, as well as modified Donnan models, and we show that the latter can be parametrized using the molecular simulation results at high concentration. This then allows us to extrapolate the capacitance and salt adsorption capacity at lower concentrations, which cannot be simulated, finding a reasonable agreement with the experimental capacitance. We analyze the solvation of ions and their confinement within the electrodes—microscopic properties that are much more difficult to obtain experimentally than the electrochemical response but very important to understand the mechanisms at play. We finally discuss the implications of our findings for CapMix and CDI, both from the modeling point of view and from the use of CDCs in these contexts.

  15. Vacuum Simulations in High Energy Accelerators and Distribution Properties of Continuous and Discrete Particle Motions

    OpenAIRE

    Aichinger, Ida; Larcher, Gerhard; Kersevan, Roberto

    2017-01-01

    The underlying thesis on mathematical simulation methods in application and theory is structured into three parts. The first part sets up a mathematical model capable of predicting the performance and operation of an accelerator’s vacuum system based on analytical methods. A coupled species-balance equation system describes the distribution of the gas dynamics in an ultra-high vacuum system considering impacts of conductance limitations, beam induced effects (ion-, electron-, and photon-induc...

  16. Improving Integrated Operation in the Joint Integrated Mission Model (JIMM) and the Simulated Warfare Environment Data Transfer (SWEDAT) Protocol

    National Research Council Canada - National Science Library

    Mutschler, David W

    2005-01-01

    ...). It allows integrated operation of resources whereby the JIMM threat environment, stimulators virtual cockpits, systems under test, and other agents are combined within the same simulation exercise...

  17. Fault-tolerant Control of Unmanned Underwater Vehicles with Continuous Faults: Simulations and Experiments

    Directory of Open Access Journals (Sweden)

    Qian Liu

    2010-02-01

    Full Text Available A novel thruster fault diagnosis and accommodation method for open-frame underwater vehicles is presented in the paper. The proposed system consists of two units: a fault diagnosis unit and a fault accommodation unit. In the fault diagnosis unit an ICMAC (Improved Credit Assignment Cerebellar Model Articulation Controllers neural network information fusion model is used to realize the fault identification of the thruster. The fault accommodation unit is based on direct calculations of moment and the result of fault identification is used to find the solution of the control allocation problem. The approach resolves the continuous faulty identification of the UV. Results from the experiment are provided to illustrate the performance of the proposed method in uncertain continuous faulty situation.

  18. Fault-tolerant Control of Unmanned Underwater Vehicles with Continuous Faults: Simulations and Experiments

    Directory of Open Access Journals (Sweden)

    Qian Liu

    2009-12-01

    Full Text Available A novel thruster fault diagnosis and accommodation method for open-frame underwater vehicles is presented in the paper. The proposed system consists of two units: a fault diagnosis unit and a fault accommodation unit. In the fault diagnosis unit an ICMAC (Improved Credit Assignment Cerebellar Model Articulation Controllers neural network information fusion model is used to realize the fault identification of the thruster. The fault accommodation unit is based on direct calculations of moment and the result of fault identification is used to find the solution of the control allocation problem. The approach resolves the continuous faulty identification of the UV. Results from the experiment are provided to illustrate the performance of the proposed method in uncertain continuous faulty situation.

  19. Thermo-mechanical simulation and parameters optimization for beam blank continuous casting

    International Nuclear Information System (INIS)

    Chen, W.; Zhang, Y.Z.; Zhang, C.J.; Zhu, L.G.; Lu, W.G.; Wang, B.X.; Ma, J.H.

    2009-01-01

    The objective of this work is to optimize the process parameters of beam blank continuous casting in order to ensure high quality and productivity. A transient thermo-mechanical finite element model is developed to compute the temperature and stress profile in beam blank continuous casting. By comparing the calculated data with the metallurgical constraints, the key factors causing defects of beam blank can be found out. Then based on the subproblem approximation method, an optimization program is developed to search out the optimum cooling parameters. Those optimum parameters can make it possible to run the caster at its maximum productivity, minimum cost and to reduce the defects. Now, online verifying of this optimization project has been put in practice, which can prove that it is very useful to control the actual production

  20. The CO{sub 2} emission permits market simulation using Continuous Double Auction

    Energy Technology Data Exchange (ETDEWEB)

    Bartoszczuk, Pawel [Warsaw School of Economics (Poland); Stanczak, Jaroslaw

    2016-07-01

    In this paper we consider the buying and selling prices of carbon dioxide (CO{sub 2}) emission permits in trading models with uncertainty. Permission prices, although usually omitted from standard models, may significantly influence the trading market. We thus construct a more realistic trade model. To do this, we introduced several important changes to the standard model, mainly we added The Continuous Double Action.

  1. Simulation of emulsion copolymerization reactions in a continuous pulsed sieve-plate column reactor

    OpenAIRE

    C. Sayer; R. Giudici

    2004-01-01

    This work addressed the viability of using a pulsed sieve-plate column reactor to carry out continuous vinyl acetate/butyl acrylate emulsion copolymerization reactions. A rigorous mathematical model of emulsion copolymerization reactions in a tubular reactor with axial dispersion was used for this purpose. Operational conditions were defined to attain high monomer conversions at the reactor outlet in a relatively short residence time and, at the same time, produce a copolymer with a more homo...

  2. Simulation of emulsion copolymerization reactions in a continuous pulsed sieve-plate column reactor

    Directory of Open Access Journals (Sweden)

    Sayer C.

    2004-01-01

    Full Text Available This work addressed the viability of using a pulsed sieve-plate column reactor to carry out continuous vinyl acetate/butyl acrylate emulsion copolymerization reactions. A rigorous mathematical model of emulsion copolymerization reactions in a tubular reactor with axial dispersion was used for this purpose. Operational conditions were defined to attain high monomer conversions at the reactor outlet in a relatively short residence time and, at the same time, produce a copolymer with a more homogeneous composition.

  3. The FEM simulation of continuous rotary extrusion (CRE) of aluminum alloy AA3003

    Science.gov (United States)

    Rajendran, Nijenthan; Valberg, Henry; Misiolek, Wojciech Z.

    2017-10-01

    Continuous Rotary Extrusion (CRE) process is also known in literature under Conform TM name and it is mainly used for the continuous extrusion of Aluminum and Copper alloys. CRE use a feedstock in the form of rod, powders and chips, which are fed into the groove of the rotating wheel. As the wheel rotates the feedstock moves along with it due to friction with the wheel. Once the feedstock reaches the abutment the material deforms plastically and it is extruded through the die. CRE has lot to offer when compared to other more conventional extrusion processes such as low energy input, no limit in billet length as it is a continuous process as well as improved material physical properties due to plastic deformation under constant parameters. In this work a FEM model has been developed using Deform TM 3D, to study the metal flow and state variables of AA3003 CRE extrusion. The effect of extrusion wheel velocity has been investigated. The results show that increase in wheel velocity will heat up the feedstock metal due to high shear deformation and higher friction, which significantly changes metal flow conditions at the die exit.

  4. Evaluation of Continuous Membrane Chromatography Concepts with an Enhanced Process Simulation Approach

    Directory of Open Access Journals (Sweden)

    Steffen Zobel-Roos

    2018-03-01

    Full Text Available Modern biopharmaceutical products strive for small-scale, low-cost production. Continuous chromatography has shown to be a promising technology because it assures high-capacity utilization, purity and yield increases, and lower facility footprint. Membrane chromatography is a fully disposable low-cost alternative to bead-based chromatography with minor drawbacks in terms of capacity. Hence, continuous membrane chromatography should have a high potential. The evaluation of continuous processes goes often along with process modeling. Only few experiments with small feed demand need to be conducted to estimate the model parameters. Afterwards, a variety of different process setups and working points can be analyzed in a very short time, making the approach very efficient. Since the available modeling approaches for membrane chromatography modules did not fit the used design, a new modeling approach is shown. This combines the general rate model with an advanced fluid dynamic distribution. Model parameter determination and model validation were done with industrial cell cultures containing Immunoglobulin G (IgG. The validated model was used to evaluate the feasibility of the integrated Counter Current Chromatography (iCCC concept and the sequential chromatography concept for membrane adsorber modules, starting with a laboratory-type module used for sample preparation. A case study representing a fed-batch reactor with a capacity from 20 to 2000 L was performed. Compared to batch runs, a 71% higher capacity, 48.5% higher productivity, and 38% lower eluent consumption could be achieved.

  5. Gas mission; Mission gaz

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This preliminary report analyses the desirable evolutions of gas transport tariffing and examines some questions relative to the opening of competition on the French gas market. The report is made of two documents: a synthesis of the previous report with some recommendations about the tariffing of gas transport, about the modalities of network access to third parties, and about the dissociation between transport and trade book-keeping activities. The second document is the progress report about the opening of the French gas market. The first part presents the European problem of competition in the gas supply and its consequences on the opening and operation of the French gas market. The second part presents some partial syntheses about each topic of the mission letter of the Ministry of Economics, Finances and Industry: future evolution of network access tariffs, critical analysis of contractual documents for gas transport and delivery, examination of auxiliary services linked with the access to the network (modulation, balancing, conversion), consideration about the processing of network congestions and denied accesses, analysis of the metering dissociation between the integrated activities of gas operators. Some documents are attached in appendixes: the mission letter from July 9, 2001, the detailed analysis of the new temporary tariffs of GdF and CFM, the offer of methane terminals access to third parties, the compatibility of a nodal tariffing with the presence of three transport operators (GdF, CFM and GSO), the contract-type for GdF supply, and the contract-type for GdF connection. (J.S.)

  6. Feasibility of scenario-based simulation training versus traditional workshops in continuing medical education: a randomized controlled trial

    Science.gov (United States)

    Kerr, Brendan; Hawkins, Trisha Lee-Ann; Herman, Robert; Barnes, Sue; Kaufmann, Stephanie; Fraser, Kristin; Ma, Irene W. Y.

    2013-01-01

    Introduction Although simulation-based training is increasingly used for medical education, its benefits in continuing medical education (CME) are less established. This study seeks to evaluate the feasibility of incorporating simulation-based training into a CME conference and compare its effectiveness with the traditional workshop in improving knowledge and self-reported confidence. Methods Participants (N=27) were group randomized to either a simulation-based workshop or a traditional case-based workshop. Results Post-training, knowledge assessment score neither did increase significantly in the traditional group (d=0.13; p=0.76) nor did significantly decrease in the simulation group (d= − 0.44; p=0.19). Self-reported comfort in patient assessment parameters increased in both groups (psimulation-based training was not associated with benefits in knowledge acquisition, knowledge retention, or comfort in patient assessment. It was associated with superior outcomes in comfort in patient management, but this benefit may be short-lived. Further studies are required to better define the conditions under which simulation-based training is beneficial. PMID:23870304

  7. Processing of high-temperature simulated waste glass in a continuous ceramic melter

    International Nuclear Information System (INIS)

    Barnes, S.M.; Brouns, R.A.; Hanson, M.S.

    1980-01-01

    Recent operations have demonstrated that high-melting-point glasses and glass-ceramics can be successfully processed in joule-heated, ceramic-lined melters with minor modifications to the existing technology. Over 500 kg of simulated waste glasses have been processed at temperatures up to 1410 0 C. The processability of the two high-temperature waste forms tested is similar to existing borosilicate waste glasses. High-temperature waste glass formulations produced in the bench-scale melter exhibit quality comparing favorably to standard waste glass formulations

  8. Simulation of an electrostatic soot-filter with continuous electrochemical conversion during the stages of development

    International Nuclear Information System (INIS)

    Muri, M.

    1996-04-01

    The dissertation describes the simulation of an electrostatic Diesel-Soot-Converter during its stages of development. This simulation is not only necessary for the interpretation of the experimental results, it also shows results for assumptions that cannot be received experimentally. The Diesel-Soot-Converter consists of a charging electrode, which charges the particles by a high-voltage and a ceramic monolith, where the particles are precipitated in the open channels because of an electric field created also by a high-voltage. Afterwards the particles are burned by a plasma. The filter-function of the Diesel-Soot-Converter was formulated and the efficiency for a vehicle was calculated. In the first part of the calculation the mass flow of a BMW 318tds and a BMW 325tds was determined for an US-FTP75-testcycle and for fuel load. In the second part the efficiency of different Diesel-Soot-Converter-types was calculated for the US-FTP75-testcycle and for full load. The use of the program with other testcycles is possible. The results of the calculations show the best configuration of the Diesel-Soot-Converter for the corresponding vehicle. Therefore with the help of this program time and money for the production of the ceramic can be saved. (author)

  9. Implementation of Dryden Continuous Turbulence Model into Simulink for LSA-02 Flight Test Simulation

    Science.gov (United States)

    Ichwanul Hakim, Teuku Mohd; Arifianto, Ony

    2018-04-01

    Turbulence is a movement of air on small scale in the atmosphere that caused by instabilities of pressure and temperature distribution. Turbulence model is integrated into flight mechanical model as an atmospheric disturbance. Common turbulence model used in flight mechanical model are Dryden and Von Karman model. In this minor research, only Dryden continuous turbulence model were made. Dryden continuous turbulence model has been implemented, it refers to the military specification MIL-HDBK-1797. The model was implemented into Matlab Simulink. The model will be integrated with flight mechanical model to observe response of the aircraft when it is flight through turbulence field. The turbulence model is characterized by multiplying the filter which are generated from power spectral density with band-limited Gaussian white noise input. In order to ensure that the model provide a good result, model verification has been done by comparing the implemented model with the similar model that is provided in aerospace blockset. The result shows that there are some difference for 2 linear velocities (vg and wg), and 3 angular rate (pg, qg and rg). The difference is instantly caused by different determination of turbulence scale length which is used in aerospace blockset. With the adjustment of turbulence length in the implemented model, both model result the similar output.

  10. Mathematics simulation and experiments of continuous casting with strip feeding in mold

    Directory of Open Access Journals (Sweden)

    M. G. Shen

    2017-01-01

    Full Text Available Steel strip feeding technology can reduce the degree of superheat of the molten steel, change the solidification order of the molten steel; raise the equiaxed crystal rate of the slab and improve the continuous casting quality. The paper establishes the mathematical model of heat transfer and temperature field of casting billet of steel strip feeding in continuous casting mold. Results show that if Plate Billet is 1 000 mm × 220 mm and the steel strip is 100 mm × 3 mm, feeding position of parallel is 250 mm from the narrow side. When the feeding speed is 3,6 m/min, the superheat degree can be reduced by 5 °C, and the solidification length can be reduced by 2,9 m. When the feeding speed is 6 m/min, the superheat degree can be reduced by about 9 °C, and the solidification length can be reduced by 3,7 m. The results of the test in a steel plant are in good agreement with the experimental results.

  11. Uncertainties of flood frequency estimation approaches based on continuous simulation using data resampling

    Science.gov (United States)

    Arnaud, Patrick; Cantet, Philippe; Odry, Jean

    2017-11-01

    Flood frequency analyses (FFAs) are needed for flood risk management. Many methods exist ranging from classical purely statistical approaches to more complex approaches based on process simulation. The results of these methods are associated with uncertainties that are sometimes difficult to estimate due to the complexity of the approaches or the number of parameters, especially for process simulation. This is the case of the simulation-based FFA approach called SHYREG presented in this paper, in which a rainfall generator is coupled with a simple rainfall-runoff model in an attempt to estimate the uncertainties due to the estimation of the seven parameters needed to estimate flood frequencies. The six parameters of the rainfall generator are mean values, so their theoretical distribution is known and can be used to estimate the generator uncertainties. In contrast, the theoretical distribution of the single hydrological model parameter is unknown; consequently, a bootstrap method is applied to estimate the calibration uncertainties. The propagation of uncertainty from the rainfall generator to the hydrological model is also taken into account. This method is applied to 1112 basins throughout France. Uncertainties coming from the SHYREG method and from purely statistical approaches are compared, and the results are discussed according to the length of the recorded observations, basin size and basin location. Uncertainties of the SHYREG method decrease as the basin size increases or as the length of the recorded flow increases. Moreover, the results show that the confidence intervals of the SHYREG method are relatively small despite the complexity of the method and the number of parameters (seven). This is due to the stability of the parameters and takes into account the dependence of uncertainties due to the rainfall model and the hydrological calibration. Indeed, the uncertainties on the flow quantiles are on the same order of magnitude as those associated with

  12. Computer Simulation of the Formation of Non-Metallic Precipitates During a Continuous Casting of Steel

    Directory of Open Access Journals (Sweden)

    Kalisz D.

    2016-03-01

    Full Text Available The authors own computer software, based on the Ueshima mathematical model with taking into account the back diffusion, determined from the Wołczyński equation, was developed for simulation calculations. The applied calculation procedure allowed to determine the chemical composition of the non-metallic phase in steel deoxidised by means of Mn, Si and Al, at the given cooling rate. The calculation results were confirmed by the analysis of samples taken from the determined areas of the cast ingot. This indicates that the developed computer software can be applied for designing the steel casting process of the strictly determined chemical composition and for obtaining the required non-metallic precipitates.

  13. A comparative analysis of 9 multi-model averaging approaches in hydrological continuous streamflow simulation

    Science.gov (United States)

    Arsenault, Richard; Gatien, Philippe; Renaud, Benoit; Brissette, François; Martel, Jean-Luc

    2015-10-01

    This study aims to test whether a weighted combination of several hydrological models can simulate flows more accurately than the models taken individually. In addition, the project attempts to identify the most efficient model averaging method and the optimal number of models to include in the weighting scheme. In order to address the first objective, streamflow was simulated using four lumped hydrological models (HSAMI, HMETS, MOHYSE and GR4J-6), each of which were calibrated with three different objective functions on 429 watersheds. The resulting 12 hydrographs (4 models × 3 metrics) were weighted and combined with the help of 9 averaging methods which are the simple arithmetic mean (SAM), Akaike information criterion (AICA), Bates-Granger (BGA), Bayes information criterion (BICA), Bayesian model averaging (BMA), Granger-Ramanathan average variant A, B and C (GRA, GRB and GRC) and the average by SCE-UA optimization (SCA). The same weights were then applied to the hydrographs in validation mode, and the Nash-Sutcliffe Efficiency metric was measured between the averaged and observed hydrographs. Statistical analyses were performed to compare the accuracy of weighted methods to that of individual models. A Kruskal-Wallis test and a multi-objective optimization algorithm were then used to identify the most efficient weighted method and the optimal number of models to integrate. Results suggest that the GRA, GRB, GRC and SCA weighted methods perform better than the individual members. Model averaging from these four methods were superior to the best of the individual members in 76% of the cases. Optimal combinations on all watersheds included at least one of each of the four hydrological models. None of the optimal combinations included all members of the ensemble of 12 hydrographs. The Granger-Ramanathan average variant C (GRC) is recommended as the best compromise between accuracy, speed of execution, and simplicity.

  14. Continued Development Of An Inexpensive Simulator Based CT Scanner For Radiation Therapy Treatment Planning

    Science.gov (United States)

    Peschmann, K. R.; Parker, D. L.; Smith, V.

    1982-11-01

    An abundant number of different CT scanner models has been developed in the past ten years, meeting increasing standards of performance. From the beginning they remained a comparatively expensive piece of equipment. This is due not only to their technical complexity but is also due to the difficulties involved in assessing "true" specifications (avoiding "overde-sign"). Our aim has been to provide, for Radiation Therapy Treatment Planning, a low cost CT scanner system featuring large freedom in patient positioning. We have taken advantage of the concurrent tremendously increased amount of knowledge and experience in the technical area of CT1 . By way of extensive computer simulations we gained confidence that an inexpensive C-arm simulator gantry and a simple one phase-two pulse generator in connection with a standard x-ray tube could be used, without sacrificing image quality. These components have been complemented by a commercial high precision shaft encoder, a simple and effective fan beam collimator, a high precision, high efficiency, luminescence crystal-silicon photodiode detector with 256 channels, low noise electronic preamplifier and sampling filter stages, a simplified data aquisition system furnished by Toshiba/ Analogic and an LSI 11/23 microcomputer plus data storage disk as well as various smaller interfaces linking the electrical components. The quality of CT scan pictures of phantoms,performed by the end of last year confirmed that this simple approach is working well. As a next step we intend to upgrade this system with an array processor in order to shorten recon-struction time to one minute per slice. We estimate that the system including this processor could be manufactured for a selling price of $210,000.

  15. Continuous energy Neutron Transport Monte Carlo Simulator Project: Decomposition of the neutron energy spectrum by target nuclei tagging

    Energy Technology Data Exchange (ETDEWEB)

    Barcellos, Luiz Felipe F.C.; Bodmann, Bardo E.J.; Vilhena, Marco T.M.B., E-mail: luizfelipe.fcb@gmail.com, E-mail: bardo.bodmann@ufrgs.br, E-mail: mtmbvilhena@gmail.com [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Grupo de Estudos Nucleares; Leite, Sergio Q. Bogado, E-mail: sbogado@ibest.com.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    In this work a Monte Carlo simulator with continuous energy is used. This simulator distinguishes itself by using the sum of three probability distributions to represent the neutron spectrum. Two distributions have known shape, but have varying population of neutrons in time, and these are the fission neutron spectrum (for high energy neutrons) and the Maxwell-Boltzmann distribution (for thermal neutrons). The third distribution has an a priori unknown and possibly variable shape with time and is determined from parametrizations of Monte Carlo simulation. It is common practice in neutron transport calculations, e.g. multi-group transport, to consider that the neutrons only lose energy with each scattering reaction and then to use a thermal group with a Maxwellian distribution. Such an approximation is valid due to the fact that for fast neutrons up-scattering occurrence is irrelevant, being only appreciable at low energies, i.e. in the thermal energy region, in which it can be regarded as a Maxwell-Boltzmann distribution for thermal equilibrium. In this work the possible neutron-matter interactions are simulated with exception of the up-scattering of neutrons. In order to preserve the thermal spectrum, neutrons are selected stochastically as being part of the thermal population and have an energy attributed to them taken from a Maxwellian distribution. It is then shown how this procedure can emulate the up-scattering effect by the increase in the neutron population kinetic energy. Since the simulator uses tags to identify the reactions it is possible not only to plot the distributions by neutron energy, but also by the type of interaction with matter and with the identification of the target nuclei involved in the process. This work contains some preliminary results obtained from a Monte Carlo simulator for neutron transport that is being developed at Federal University of Rio Grande do Sul. (author)

  16. Advanced Distributed Simulation Technology II (ADST-II) Distributed Interactive Fire Mission II Concept Evaluation Program Final Report

    National Research Council Canada - National Science Library

    1999-01-01

    ...), Fort Knox, KY sponsored the experiment. The experiment utilized a synthetic environment that employed virtual simulations to depict an Armor Platoon executing six basic platoon-level scenarios in realistic combat situations in various...

  17. Continuous microalgal cultivation in a laboratory-scale photobioreactor under seasonal day-night irradiation: experiments and simulation.

    Science.gov (United States)

    Bertucco, Alberto; Beraldi, Mariaelena; Sforza, Eleonora

    2014-08-01

    In this work, the production of Scenedesmus obliquus in a continuous flat-plate laboratory-scale photobioreactor (PBR) under alternated day-night cycles was tested both experimentally and theoretically. Variation of light intensity according to the four seasons of the year were simulated experimentally by a tunable LED lamp, and effects on microalgal growth and productivity were measured to evaluate the conversion efficiency of light energy into biomass during the different seasons. These results were used to validate a mathematical model for algae growth that can be applied to simulate a large-scale production unit, carried out in a flat-plate PBR of similar geometry. The cellular concentration in the PBR was calculated in both steady-state and transient conditions, and the value of the maintenance kinetic term was correlated to experimental profiles. The relevance of this parameter was finally outlined.

  18. Mathematical simulation and calculation of the continuous countercurrent process of ion-exchange extraction of strontium from strongly mineralized solutions

    International Nuclear Information System (INIS)

    Nikashina, V.A.; Guryanova, L.N.; Baturova, L.L.; Venetsianov, E.V.; Ivanov, V.A.; Nikolaev, N.P.

    1993-01-01

    The program open-quotes Countercurrentclose quotes is developed for the simulation of a continuous ion-exchange extraction of strontium from strongly mineralized NaCl and CaCl 2 solutions using a KB-4 carboxylic cation-exchanger in the countercurrent columns. The program allows one to Calculate the conditions of Ca and Sr separation depending on the mode of operation at the sorption and regeneration stages, the residual Sr content on the overloaded sorbent, and the Sr separation on incompletely regenerated KB-4. It also makes it possible to find the optimal separation conditions. The program open-quotes Countercurrentclose quotes can be also used to simulate other ion-exchange processes

  19. Mathematical simulation and calculation of continuous countercurrent process of ion-exchange extraction of strontium from strongly mineralized solutions

    International Nuclear Information System (INIS)

    Nikashina, V.A.; Venitsianov, E.V.; Ivanov, V.A.; Gur'yanova, L.N.; Nikolaev, N.P.; Baturova, L.L.; Moskovskij Gosudarstvennyj Univ., Moscow

    1993-01-01

    A program 'Countercurrent' is developed for the simulation of a continuous ion-exchange extraction of strontium from the strongly mineralized solutions containing NaCl and CaCl 2 using carboxylic cation exchanger KB-4 in countercurrent columns. The use of the program allows one to calculate the consitions of Ca and Sr separation depending on the modes of operation at the stage of sorption as well as regeneration, to calculate a residual Sr content on an overloaded sorbent and Sr separation on an incompletely regenerated KB-4, and to find the optimal separation conditions

  20. [The mission].

    Science.gov (United States)

    Ruiz Moreno, J; Blanch Mon, A

    2000-01-01

    After having made a historical review of the concept of mission statement, of evaluating its importance (See Part I), of describing the bases to create a mission statement from a strategic perspective and of analyzing the advantages of this concept, probably more important as a business policy (See Parts I and II), the authors proceed to analyze the mission statement in health organizations. Due to the fact that a mission statement is lacking in the majority of health organizations, the strategy of health organizations are not exactly favored; as a consequence, neither are its competitive advantage nor the development of its essential competencies. After presenting a series of mission statements corresponding to Anglo-Saxon health organizations, the authors highlight two mission statements corresponding to our social context. The article finishes by suggesting an adequate sequence for developing a mission statement in those health organizations having a strategic sense.

  1. Simulation of uranium aluminide dissolution in a continuous aluminum dissolver system

    International Nuclear Information System (INIS)

    Evans, D.R.; Farman, R.F.; Christian, J.D.

    1990-01-01

    This paper reports on the Idaho Chemical Processing Plant (ICPP) which recovers highly-enriched uranium (uranium that contains at least 20 atom percent 235 U) from spent nuclear reactor fuel by dissolution of the fuel elements and extraction of the uranium from the aqueous dissolver product. Because the uranium is highly-enriched, consideration must be given to whether a critical mass can form at any stage of the process. In particular, suspended 235 U-containing particles are of special concern, due to their high density (6.8 g/cm 3 ) and due to the fact that they can settle into geometrically unfavorable configurations when not adequately mixed. A portion of the spent fuel is aluminum-alloy-clad uranium aluminide (UAl 3 ) particles, which dissolve more slowly than the cladding. As the aluminum alloy cladding dissolves in mercury-catalyzed nitric acid, UAl 3 is released. Under standard operating conditions, the UAl 3 dissolves rapidly enough to preclude the possibility of forming a critical mass anywhere in the system. However, postulated worst-case abnormal operating conditions retard uranium aluminide dissolution, and thus require evaluation. To establish safety limits for operating parameters, a computerized simulation model of uranium aluminide dissolution in the aluminum fuel dissolver system was developed

  2. Continuous rainfall simulation for regional flood risk assessment - application in the Austrian Alps

    Science.gov (United States)

    Salinas, Jose Luis; Nester, Thomas; Komma, Jürgen; Blöschl, Günter

    2017-04-01

    Generation of realistic synthetic spatial rainfall is of pivotal importance for assessing regional hydroclimatic hazard as the input for long term rainfall-runoff simulations. The correct reproduction of the observed rainfall characteristics, such as regional intensity-duration-frequency curves, is necessary to adequately model the magnitude and frequency of the flood peaks. Furthermore, the replication of the observed rainfall spatial and temporal correlations allows to model important other hydrological features like antecedent soil moisture conditions before extreme rainfall events. In this work, we present an application in the Tirol region (Austrian alps) of a modification of the model presented by Bardossy and Platte (1992), where precipitation is modeled on a station basis as a mutivariate autoregressive model (mAr) in a Normal space, and then transformed to a Gamma-distributed space. For the sake of simplicity, the parameters of the Gamma distributions are assumed to vary monthly according to a sinusoidal function, and are calibrated trying to simultaneously reproduce i) mean annual rainfall, ii) mean daily rainfall amounts, iii) standard deviations of daily rainfall amounts, and iv) 24-hours intensity duration frequency curve. The calibration of the spatial and temporal correlation parameters is performed in a way that the intensity-duration-frequency curves aggregated at different spatial and temporal scales reproduce the measured ones. Bardossy, A., and E. J. Plate (1992), Space-time model for daily rainfall using atmospheric circulation patterns, Water Resour. Res., 28(5), 1247-1259, doi:10.1029/91WR02589.

  3. Computer simulations for the Mars Atmospheric and Volatile EvolutioN (MAVEN) mission through NASA's "Project Spectra!"

    Science.gov (United States)

    Christofferson, R.; Wood, E. L.; Euler, G.

    2012-12-01

    "Project Spectra!" is a standards-based light science and engineering program on solar system exploration that includes both hands-on paper and pencil activities as well as Flash-based computer games that help students solidify understanding of high-level planetary and solar physics. Using computer interactive games where students experience and manipulate the information makes abstract concepts accessible. Visualizing lessons with multi-media tools solidifies understanding and retention of knowledge. Since students can choose what to watch and explore, the interactives accommodate a broad range of learning styles. Students can go back and forth through the interactives if they've missed a concept or wish to view something again. In the end, students are asked critical thinking questions and conduct web-based research. As a part of the Mars Atmospheric and Volatile EvolutioN (MAVEN) mission education programming, we've developed two new "Project Spectra!" interactives that go hand-in-hand with a paper and pencil activity. The MAVEN mission will study volatiles in the upper atmosphere to help piece together Mars' climate history. In the first interactive, students explore black body radiation, albedo, and a simplified greenhouse effect to establish what factors contribute to overall planetary temperature and how they contribute. Students are asked to create a scenario in which a planet they build and design is able to maintain liquid water on the surface. In the second interactive, students are asked to consider Mars and the conditions needed for Mars to support water on the surface, keeping some variables fixed. Ideally, students will walk away with the very basic and critical elements required for climate studies, which has far-reaching implications beyond the study of Mars. These interactives are currently being pilot tested at Arvada High School in Colorado.

  4. Computer simulations for the Mars Atmospheric and Volatile EvolutioN (MAVEN) mission through NASA's 'Project Spectra!'

    Science.gov (United States)

    Wood, E. L.

    2013-12-01

    'Project Spectra!' is a standards-based light science and engineering program on solar system exploration that includes both hands-on paper and pencil activities as well as Flash-based computer games that help students solidify understanding of high-level planetary and solar physics. Using computer interactive games where students experience and manipulate the information makes abstract concepts accessible. Visualizing lessons with multi-media tools solidifies understanding and retention of knowledge. Since students can choose what to watch and explore, the interactives accommodate a broad range of learning styles. Students can go back and forth through the interactives if they've missed a concept or wish to view something again. In the end, students are asked critical thinking questions and conduct web-based research. As a part of the Mars Atmospheric and Volatile EvolutioN (MAVEN) mission education programming, we've developed two new 'Project Spectra!' interactives that go hand-in-hand with a paper and pencil activity. The MAVEN mission will study volatiles in the upper atmosphere to help piece together Mars' climate history. In the first interactive, students explore black body radiation, albedo, and a simplified greenhouse effect to establish what factors contribute to overall planetary temperature and how they contribute. Students are asked to create a scenario in which a planet they build and design is able to maintain liquid water on the surface. In the second interactive, students are asked to consider Mars and the conditions needed for Mars to support water on the surface, keeping some variables fixed. Ideally, students will walk away with the very basic and critical elements required for climate studies, which has far-reaching implications beyond the study of Mars. These interactives were pilot tested at Arvada High School in Colorado.

  5. A stochastic model for neutron simulation considering the spectrum and nuclear properties with continuous dependence of energy

    International Nuclear Information System (INIS)

    Camargo, Dayana Queiroz de

    2011-01-01

    This thesis has developed a stochastic model to simulate the neutrons transport in a heterogeneous environment, considering continuous neutron spectra and the nuclear properties with its continuous dependence on energy. This model was implemented using Monte Carlo method for the propagation of neutrons in different environment. Due to restrictions with respect to the number of neutrons that can be simulated in reasonable computational processing time introduced the variable control volume along the (pseudo-) periodic boundary conditions in order to overcome this problem. The choice of class physical Monte Carlo is due to the fact that it can decompose into simpler constituents the problem of solve a transport equation. The components may be treated separately, these are the propagation and interaction while respecting the laws of energy conservation and momentum, and the relationships that determine the probability of their interaction. We are aware of the fact that the problem approached in this thesis is far from being comparable to building a nuclear reactor, but this discussion the main target was to develop the Monte Carlo model, implement the code in a computer language that allows extensions of modular way. This study allowed a detailed analysis of the influence of energy on the neutron population and its impact on the life cycle of neutrons. From the results, even for a simple geometrical arrangement, we can conclude the need to consider the energy dependence, i.e. an spectral effective multiplication factor should be introduced each energy group separately. (author)

  6. PARTICLE-IN-CELL SIMULATIONS OF CONTINUOUSLY DRIVEN MIRROR AND ION CYCLOTRON INSTABILITIES IN HIGH BETA ASTROPHYSICAL AND HELIOSPHERIC PLASMAS

    International Nuclear Information System (INIS)

    Riquelme, Mario A.; Quataert, Eliot; Verscharen, Daniel

    2015-01-01

    We use particle-in-cell simulations to study the nonlinear evolution of ion velocity space instabilities in an idealized problem in which a background velocity shear continuously amplifies the magnetic field. We simulate the astrophysically relevant regime where the shear timescale is long compared to the ion cyclotron period, and the plasma beta is β ∼ 1-100. The background field amplification in our calculation is meant to mimic processes such as turbulent fluctuations or MHD-scale instabilities. The field amplification continuously drives a pressure anisotropy with p > p ∥ and the plasma becomes unstable to the mirror and ion cyclotron instabilities. In all cases, the nonlinear state is dominated by the mirror instability, not the ion cyclotron instability, and the plasma pressure anisotropy saturates near the threshold for the linear mirror instability. The magnetic field fluctuations initially undergo exponential growth but saturate in a secular phase in which the fluctuations grow on the same timescale as the background magnetic field (with δB ∼ 0.3 (B) in the secular phase). At early times, the ion magnetic moment is well-conserved but once the fluctuation amplitudes exceed δB ∼ 0.1 (B), the magnetic moment is no longer conserved but instead changes on a timescale comparable to that of the mean magnetic field. We discuss the implications of our results for low-collisionality astrophysical plasmas, including the near-Earth solar wind and low-luminosity accretion disks around black holes

  7. A Novel Idea for Optimizing Condition-Based Maintenance Using Genetic Algorithms and Continuous Event Simulation Techniques

    Directory of Open Access Journals (Sweden)

    Mansoor Ahmed Siddiqui

    2017-01-01

    Full Text Available Effective maintenance strategies are of utmost significance for system engineering due to their direct linkage with financial aspects and safety of the plants’ operation. At a point where the state of a system, for instance, level of its deterioration, can be constantly observed, a strategy based on condition-based maintenance (CBM may be affected; wherein upkeep of the system is done progressively on the premise of monitored state of the system. In this article, a multicomponent framework is considered that is continuously kept under observation. In order to decide an optimal deterioration stage for the said system, Genetic Algorithm (GA technique has been utilized that figures out when its preventive maintenance should be carried out. The system is configured into a multiobjective problem that is aimed at optimizing the two desired objectives, namely, profitability and accessibility. For the sake of reality, a prognostic model portraying the advancements of deteriorating system has been employed that will be based on utilization of continuous event simulation techniques. In this regard, Monte Carlo (MC simulation has been shortlisted as it can take into account a wide range of probable options that can help in reducing uncertainty. The inherent benefits proffered by the said simulation technique are fully utilized to display various elements of a deteriorating system working under stressed environment. The proposed synergic model (GA and MC is considered to be more effective due to the employment of “drop-by-drop approach” that permits successful drive of the related search process with regard to the best optimal solutions.

  8. Effect of Continuous Motion Parameter Feedback on Laparoscopic Simulation Training: A Prospective Randomized Controlled Trial on Skill Acquisition and Retention.

    Science.gov (United States)

    Buescher, Julian Frederik; Mehdorn, Anne-Sophie; Neumann, Philipp-Alexander; Becker, Felix; Eichelmann, Ann-Kathrin; Pankratius, Ulrich; Bahde, Ralf; Foell, Daniel; Senninger, Norbert; Rijcken, Emile

    To investigate the effect of motion parameter feedback on laparoscopic basic skill acquisition and retention during a standardized box training curriculum. A Lap-X Hybrid laparoscopic simulator was designed to provide individual and continuous motion parameter feedback in a dry box trainer setting. In a prospective controlled trial, surgical novices were randomized into 2 groups (regular box group, n = 18, and Hybrid group, n = 18) to undergo an identical 5-day training program. In each group, 7 standardized tasks on laparoscopic basic skills were completed twice a day on 4 consecutive days in fixed pairs. Additionally, each participant performed a simulated standard laparoscopic cholecystectomy before (day 1) and after training (day 5) on a LAP Mentor II virtual reality (VR) trainer, allowing an independent control of skill progress in both groups. A follow-up assessment of skill retention was performed after 6 weeks with repetition of both the box tasks and VR cholecystectomy. Muenster University Hospital Training Center, Muenster, Germany. Medical students without previous surgical experience. Laparoscopic skills in both groups improved significantly during the training period, measured by the overall task performance time. The 6 week follow-up showed comparable skill retention in both groups. Evaluation of the VR cholecystectomies demonstrated significant decrease of operation time (p Simulation training on both trainers enables reliable acquisition of laparoscopic basic skills. Furthermore, individual and continuous motion feedback improves laparoscopic skill enhancement significantly in several aspects. Thus, training systems with feedback of motion parameters should be considered to achieve long-term improvement of motion economy among surgical trainees. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  9. Simulations of Continuous Descent Operations with Arrival-management Automation and Mixed Flight-deck Interval Management Equipage

    Science.gov (United States)

    Callantine, Todd J.; Kupfer, Michael; Martin, Lynne Hazel; Prevot, Thomas

    2013-01-01

    Air traffic management simulations conducted in the Airspace Operations Laboratory at NASA Ames Research Center have addressed the integration of trajectory-based arrival-management automation, controller tools, and Flight-Deck Interval Management avionics to enable Continuous Descent Operations (CDOs) during periods of sustained high traffic demand. The simulations are devoted to maturing the integrated system for field demonstration, and refining the controller tools, clearance phraseology, and procedures specified in the associated concept of operations. The results indicate a variety of factors impact the concept's safety and viability from a controller's perspective, including en-route preconditioning of arrival flows, useable clearance phraseology, and the characteristics of airspace, routes, and traffic-management methods in use at a particular site. Clear understanding of automation behavior and required shifts in roles and responsibilities is important for controller acceptance and realizing potential benefits. This paper discusses the simulations, drawing parallels with results from related European efforts. The most recent study found en-route controllers can effectively precondition arrival flows, which significantly improved route conformance during CDOs. Controllers found the tools acceptable, in line with previous studies.

  10. [Myanmar mission].

    Science.gov (United States)

    Alfandari, B; Persichetti, P; Pelissier, P; Martin, D; Baudet, J

    2004-06-01

    The authors report the accomplishment of humanitarian missions in plastic surgery performed by a small team in town practice in Yangon, about their 3 years experience in Myanmar with 300 consultations and 120 surgery cases. They underline the interest of this type of mission and provide us their reflexion about team training, the type of relation with the country where the mission is conducted and the type of right team.

  11. Large Eddy Simulations of Electromagnetic Braking Effects on Argon Bubble Transport and Capture in a Steel Continuous Casting Mold

    Science.gov (United States)

    Jin, Kai; Vanka, Surya P.; Thomas, Brian G.

    2018-06-01

    In continuous casting of steel, argon gas is often injected to prevent clogging of the nozzle, but the bubbles affect the flow pattern, and may become entrapped to form defects in the final product. Further, an electromagnetic field is frequently applied to induce a braking effect on the flow field and modify the inclusion transport. In this study, a previously validated GPU-based in-house code CUFLOW is used to investigate the effect of electromagnetic braking on turbulent flow, bubble transport, and capture. Well-resolved large eddy simulations are combined with two-way coupled Lagrangian computations of the bubbles. The drag coefficient on the bubbles is modified to account for the effects of the magnetic field. The distribution of the argon bubbles, capture, and escape rates, are presented and compared with and without the magnetic field. The bubble capture patterns are also compared with results of a previous RANS model as well as with plant measurements.

  12. Studentized Continuous Wavelet Transform (t-CWT in the Analysis of Individual ERPs: Real and Simulated EEG Data

    Directory of Open Access Journals (Sweden)

    Ruben Gustav Leonhardt Real

    2014-09-01

    Full Text Available This study aimed at evaluating the performance of the Studentized Continuous Wavelet Transform (t-CWT as a method for the extraction and assessment of event-related brain potentials (ERP in data from a single subject. Sensitivity, specificity, positive (PPV and negative predictive values (NPV of the t-CWT were assessed and compared to a variety of competing procedures using simulated EEG data at six low signal-to-noise ratios. Results show that the t-CWT combines high sensitivity and specificity with favorable PPV and NPV. Applying the t-CWT to authentic EEG data obtained from 14 healthy participants confirmed its high sensitivity. The t-CWT may thus be well suited for the assessment of weak ERPs in single-subject settings.

  13. The Contribution of the Future SWOT Mission to Improve Simulations of River Stages and Stream-Aquifer Interactions at Regional Scale

    Science.gov (United States)

    Saleh, Firas; Filipo, Nicolas; Biancamaria, Sylvain; Habets, Florence; Rodriguez, Enersto; Mognard, Nelly

    2013-09-01

    The main objective of this study is to provide a realistic simulation of river stage in regional river networks in order to improve the quantification of stream-aquifer exchanges and better assess the associated aquifer responses that are often impacted by the magnitude and the frequency of the river stage fluctuations. This study extends the earlier work to improve the modeling of the Seine basin with a focus on simulating the hydrodynamics behavior of the Bassée alluvial wetland, a 120 km reach of the Seine River valley located south- east of Paris. The Bassée is of major importance for the drinking-water supply of Paris and surroundings, in addition to its particular hydrodynamic behavior due to the presence of a number of gravels. In this context, the understanding of stream-aquifer interactions is required for water quantity and quality preservation. A regional distributed process-based hydro(geo)logical model, Eau-Dyssée, is used. It aims at the integrated modeling of the hydrosystem to manage the various elements involved in the quantitative and qualitative aspects of water resources. Eau-Dyssée simulates pseudo 3D flow in aquifer systems solving the diffusivity equation with a finite difference numerical scheme. River flow is simulated with a Muskingum model. In addition to the in-stream discharge, a river stage estimate is needed to calculate the water exchange at the stream-aquifer interface using a conductance model. In this context, the future SWOT mission and its high-spatial resolution imagery can provide surface water level measurements at the regional scale that will permit to better characterize the Bassée complex hydro(geo)logical system and better assess soil water content. Moreover, the Bassée is considered as a potential target for the framework of the AirSWOT airborne campaign in France, 2013.

  14. Spatial updating grand canonical Monte Carlo algorithms for fluid simulation: generalization to continuous potentials and parallel implementation.

    Science.gov (United States)

    O'Keeffe, C J; Ren, Ruichao; Orkoulas, G

    2007-11-21

    Spatial updating grand canonical Monte Carlo algorithms are generalizations of random and sequential updating algorithms for lattice systems to continuum fluid models. The elementary steps, insertions or removals, are constructed by generating points in space either at random (random updating) or in a prescribed order (sequential updating). These algorithms have previously been developed only for systems of impenetrable spheres for which no particle overlap occurs. In this work, spatial updating grand canonical algorithms are generalized to continuous, soft-core potentials to account for overlapping configurations. Results on two- and three-dimensional Lennard-Jones fluids indicate that spatial updating grand canonical algorithms, both random and sequential, converge faster than standard grand canonical algorithms. Spatial algorithms based on sequential updating not only exhibit the fastest convergence but also are ideal for parallel implementation due to the absence of strict detailed balance and the nature of the updating that minimizes interprocessor communication. Parallel simulation results for three-dimensional Lennard-Jones fluids show a substantial reduction of simulation time for systems of moderate and large size. The efficiency improvement by parallel processing through domain decomposition is always in addition to the efficiency improvement by sequential updating.

  15. A Model Stitching Architecture for Continuous Full Flight-Envelope Simulation of Fixed-Wing Aircraft and Rotorcraft from Discrete Point Linear Models

    Science.gov (United States)

    2016-04-01

    AND ROTORCRAFT FROM DISCRETE -POINT LINEAR MODELS Eric L. Tobias and Mark B. Tischler Aviation Development Directorate Aviation and Missile...Stitching Architecture for Continuous Full Flight-Envelope Simulation of Fixed-Wing Aircraft and Rotorcraft from Discrete -Point Linear Models 5...of discrete -point linear models and trim data. The model stitching simulation architecture is applicable to any aircraft configuration readily

  16. Simulating the reactions of CO2 in aqueous monoethanolamine solution by reaction ensemble Monte Carlo using the continuous fractional component method

    NARCIS (Netherlands)

    Balaji, S.P.; Gangarapu, S.; Ramdin, M.; Torres-Knoop, A.; Zuilhof, H.; Goetheer, E.L.V.; Dubbeldam, D.; Vlugt, T.J.H.

    2015-01-01

    Molecular simulations were used to compute the equilibrium concentrations of the different species in CO2/monoethanolamine solutions for different CO2 loadings. Simulations were performed in the Reaction Ensemble using the continuous fractional component Monte Carlo method at temperatures of 293,

  17. SIMULATION FROM ENDPOINT-CONDITIONED, CONTINUOUS-TIME MARKOV CHAINS ON A FINITE STATE SPACE, WITH APPLICATIONS TO MOLECULAR EVOLUTION.

    Science.gov (United States)

    Hobolth, Asger; Stone, Eric A

    2009-09-01

    Analyses of serially-sampled data often begin with the assumption that the observations represent discrete samples from a latent continuous-time stochastic process. The continuous-time Markov chain (CTMC) is one such generative model whose popularity extends to a variety of disciplines ranging from computational finance to human genetics and genomics. A common theme among these diverse applications is the need to simulate sample paths of a CTMC conditional on realized data that is discretely observed. Here we present a general solution to this sampling problem when the CTMC is defined on a discrete and finite state space. Specifically, we consider the generation of sample paths, including intermediate states and times of transition, from a CTMC whose beginning and ending states are known across a time interval of length T. We first unify the literature through a discussion of the three predominant approaches: (1) modified rejection sampling, (2) direct sampling, and (3) uniformization. We then give analytical results for the complexity and efficiency of each method in terms of the instantaneous transition rate matrix Q of the CTMC, its beginning and ending states, and the length of sampling time T. In doing so, we show that no method dominates the others across all model specifications, and we give explicit proof of which method prevails for any given Q, T, and endpoints. Finally, we introduce and compare three applications of CTMCs to demonstrate the pitfalls of choosing an inefficient sampler.

  18. Simulating water and nitrogen loss from an irrigated paddy field under continuously flooded condition with Hydrus-1D model.

    Science.gov (United States)

    Yang, Rui; Tong, Juxiu; Hu, Bill X; Li, Jiayun; Wei, Wenshuo

    2017-06-01

    Agricultural non-point source pollution is a major factor in surface water and groundwater pollution, especially for nitrogen (N) pollution. In this paper, an experiment was conducted in a direct-seeded paddy field under traditional continuously flooded irrigation (CFI). The water movement and N transport and transformation were simulated via the Hydrus-1D model, and the model was calibrated using field measurements. The model had a total water balance error of 0.236 cm and a relative error (error/input total water) of 0.23%. For the solute transport model, the N balance error and relative error (error/input total N) were 0.36 kg ha -1 and 0.40%, respectively. The study results indicate that the plow pan plays a crucial role in vertical water movement in paddy fields. Water flow was mainly lost through surface runoff and underground drainage, with proportions to total input water of 32.33 and 42.58%, respectively. The water productivity in the study was 0.36 kg m -3 . The simulated N concentration results revealed that ammonia was the main form in rice uptake (95% of total N uptake), and its concentration was much larger than for nitrate under CFI. Denitrification and volatilization were the main losses, with proportions to total consumption of 23.18 and 14.49%, respectively. Leaching (10.28%) and surface runoff loss (2.05%) were the main losses of N pushed out of the system by water. Hydrus-1D simulation was an effective method to predict water flow and N concentrations in the three different forms. The study provides results that could be used to guide water and fertilization management and field results for numerical studies of water flow and N transport and transformation in the future.

  19. Design, Simulation, Software Development, and Testing of a Compact Aircraft Tracking Payload for the CanX-7 Nanosatellite Mission

    Science.gov (United States)

    Bennett, Ian Graham

    Automatic Dependent Surveillance-Broadcast (ADS-B) is quickly becoming the new standard for more efficient air traffic control, but as a satellite/ground-based hybrid system it faces limitations on its usefulness over oceans and remote areas. Tracking of aircraft from space presents many challenges that if overcome will greatly increase the safety and efficiency of commercial air travel in these areas. This thesis presents work performed to develop a flight-ready ADS-B receiver payload for the CanX-7 technology demonstration satellite. Work presented includes a simulation of payload performance and coverage area, the design and testing of a single-feed circularly polarized L-band antenna, the design of software to control the payload and manage its data, and verification of the performance of the hardware prior to integration with the satellite and launch. Also included is a short overview of results from the seven-month aircraft tracking campaign conducted with the spacecraft.

  20. Evaluation of regional-scale water level simulations using various river routing schemes within a hydrometeorological modelling framework for the preparation of the SWOT mission

    Science.gov (United States)

    Häfliger, V.; Martin, E.; Boone, A. A.; Habets, F.; David, C. H.; Garambois, P. A.; Roux, H.; Ricci, S. M.; Thévenin, A.; Berthon, L.; Biancamaria, S.

    2014-12-01

    The ability of a regional hydrometeorological model to simulate water depth is assessed in order to prepare for the SWOT (Surface Water and Ocean Topography) mission that will observe free surface water elevations for rivers having a width larger than 50/100 m. The Garonne river (56 000 km2, in south-western France) has been selected owing to the availability of operational gauges, and the fact that different modeling platforms, the hydrometeorological model SAFRAN-ISBA-MODCOU and several fine scale hydraulic models, have been extensively evaluated over two reaches of the river. Several routing schemes, ranging from the simple Muskingum method to time-variable parameter kinematic and diffusive waves schemes with time varying parameters, are tested using predetermined hydraulic parameters. The results show that the variable flow velocity scheme is advantageous for discharge computations when compared to the original Muskingum routing method. Additionally, comparisons between water level computations and in situ observations led to root mean square errors of 50-60 cm for the improved Muskingum method and 40-50 cm for the kinematic-diffusive wave method, in the downstream Garonne river. The error is larger than the anticipated SWOT resolution, showing the potential of the mission to improve knowledge of the continental water cycle. Discharge computations are also shown to be comparable to those obtained with high-resolution hydraulic models over two reaches. However, due to the high variability of river parameters (e.g. slope and river width), a robust averaging method is needed to compare the hydraulic model outputs and the regional model. Sensitivity tests are finally performed in order to have a better understanding of the mechanisms which control the key hydrological processes. The results give valuable information about the linearity, Gaussianity and symetry of the model, in order to prepare the assimilation of river heights in the model.

  1. Simulation of a long focal length Wolter-I telescope for hard X-ray astronomy. Application to the Simbol-X and PheniX space missions

    International Nuclear Information System (INIS)

    Chauvin, M.

    2011-01-01

    The future of hard X-ray astronomy relies on the development of new instruments able to focus photons of a hundred keV. Indeed, focalization allows an important improvement in sensitivity and angular resolution. Achieved by grazing incidence reflections on Wolter-I mirrors, its use currently limited to tens of keV can be extended to higher energies thanks to a specific coating and a large focal length. As X-ray observations are only possible above the atmosphere, the size of the observatories, and hence their focal length, was limited by the launcher capacity. Over the past few years, different technologies like extendible masts or formation flight have been studied to go beyond this limit. To gain a better understanding of these telescopes, I detail the Wolter-I mirror geometry, their coating reflectivity, the detection in semi-conductor as well as the dynamic related to extendible masts and formation flight. These telescopes are complex optical systems, subject to deformations during observation and need a fine metrology system to measure these deformations for image correction. To study their performance, I developed a code reproducing the real functioning of such a telescope. Each photon is considered individually, its path and interactions depend on the behavior of the telescope structure along with time. Each component of the telescope is modeled, as well as the metrology needed for the restitution of its dynamic. The path of the photon is computed in a three dimensional vector space, using Monte-Carlo methods to reproduce the mirror defaults, their reflectivity and the interactions in the detector. The simulation produces images and energy spectra, from which we can infer the angular resolution, the field of view, the effective area and the detection efficiency. In 2006, the Simbol-X mission was selected in the framework of the formation flight studies. This concept allows a large focal length, the telescope being distributed on two independent spacecrafts

  2. Reduced dimer production in solar-simulator-pumped continuous wave iodine lasers based on model simulations and scaling and pumping studies

    Science.gov (United States)

    Costen, Robert C.; Heinbockel, John H.; Miner, Gilda A.; Meador, Willard E., Jr.; Tabibi, Bagher M.; Lee, Ja H.; Williams, Michael D.

    1995-01-01

    A numerical rate equation model for a continuous wave iodine laser with longitudinally flowing gaseous lasant is validated by approximating two experiments that compare the perfluoroalkyl iodine lasants n-C3F7I and t-C4F9I. The salient feature of the simulations is that the production rate of the dimer (C4F9)2 is reduced by one order of magnitude relative to the dimer (C3F7)2. The model is then used to investigate the kinetic effects of this reduced dimer production, especially how it improves output power. Related parametric and scaling studies are also presented. When dimer production is reduced, more monomer radicals (t-C4F9) are available to combine with iodine ions, thus enhancing depletion of the laser lower level and reducing buildup of the principal quencher, molecular iodine. Fewer iodine molecules result in fewer downward transitions from quenching and more transitions from stimulated emission of lasing photons. Enhanced depletion of the lower level reduces the absorption of lasing photons. The combined result is more lasing photons and proportionally increased output power.

  3. Real-time SWMF-Geospace at CCMC: assessing the quality of output from continuous operational simulations

    Science.gov (United States)

    Liemohn, M. W.; Welling, D. T.; De Zeeuw, D.; Kuznetsova, M. M.; Rastaetter, L.; Ganushkina, N. Y.; Ilie, R.; Toth, G.; Gombosi, T. I.; van der Holst, B.

    2016-12-01

    The ground-based magnetometer index Dst is a decent measure of the near-Earth current systems, in particular those in the storm-time inner magnetosphere. The ability of a large-scale, physics-based model to reproduce, or even predict, this index is therefore a tangible measure of the overall validity of the code for space weather research and space weather operational usage. Experimental real-time simulations of the Space Weather Modeling Framework (SWMF) are conducted at the Community Coordinated Modeling Center (CCMC), with results available there (http://ccmc.gsfc.nasa.gov/realtime.php), through the CCMC Integrated Space Weather Analysis (iSWA) site (http://iswa.ccmc.gsfc.nasa.gov/IswaSystemWebApp/), and the Michigan SWMF site (http://csem.engin.umich.edu/realtime). Presently, two configurations of the SWMF are running in real time at CCMC, both focusing on the geospace modules, using the BATS-R-US magnetohydrodynamic model, the Ridley Ionosphere Model, and with and without the Rice Convection Model for inner magnetospheric drift physics. While both have been running for several years, nearly continuous results are available since July 2015. Dst from the model output is compared against the Kyoto real-time Dst. Various quantitative measures are presented to assess the goodness of fit between the models and observations. In particular, correlation coefficients, RMSE and prediction efficiency are calculated and discussed. In addition, contingency tables are presented, demonstrating the ability of the model to predict "disturbed times" as defined by Dst values below some critical threshold. It is shown that the SWMF run with the inner magnetosphere model is significantly better at reproducing storm-time values, with prediction efficiencies above 0.25 and Heidke skill scores above 0.5. This work was funded by NASA and NSF grants, and the European Union's Horizon 2020 research and innovation programme under grant agreement 637302 PROGRESS.

  4. Mission operations technology

    Science.gov (United States)

    Varsi, Giulio

    In the last decade, the operation of a spacecraft after launch has emerged as a major component of the total cost of the mission. This trend is sustained by the increasing complexity, flexibility, and data gathering capability of the space assets and by their greater reliability and consequent longevity. The trend can, however, be moderated by the progressive transfer of selected functions from the ground to the spacecraft and by application, on the ground, of new technology. Advances in ground operations derive from the introduction in the mission operations environment of advanced microprocessor-based workstations in the class of a few million instructions per second and from the selective application of artificial intelligence technology. In the last few years a number of these applications have been developed, tested in operational settings and successfully demonstrated to users. Some are now being integrated in mission operations facilities. An analysis of mission operations indicates that the key areas are: concurrent control of multiple missions; automated/interactive production of command sequences of high integrity at low cost; automated monitoring of spacecraft health and automated aides for fault diagnosis; automated allocation of resources; automated processing of science data; and high-fidelity, high-speed spacecraft simulation. Examples of major advances in selected areas are described.

  5. Educational Technology: Transitioning from Business Continuity to Mission Continuity

    Science.gov (United States)

    Mekdeci, Kelly Broyles

    2011-01-01

    United States schools and American Overseas (A/OS) schools depend upon educational technology (ET) to support business operations and student learning experiences. Schools rely upon administrative software, on-line course modules, information databases, digital communications systems, and many other ET processes. However, ET's fragility compared…

  6. An Investigation of the Mechanical Properties of Some Martian Regolith Simulants with Respect to the Surface Properties at the InSight Mission Landing Site

    Science.gov (United States)

    Delage, Pierre; Karakostas, Foivos; Dhemaied, Amine; Belmokhtar, Malik; Lognonné, Philippe; Golombek, Matt; De Laure, Emmanuel; Hurst, Ken; Dupla, Jean-Claude; Kedar, Sharon; Cui, Yu Jun; Banerdt, Bruce

    2017-10-01

    In support of the InSight mission in which two instruments (the SEIS seismometer and the HP3 heat flow probe) will interact directly with the regolith on the surface of Mars, a series of mechanical tests were conducted on three different regolith simulants to better understand the observations of the physical and mechanical parameters that will be derived from InSight. The mechanical data obtained were also compared to data on terrestrial sands. The density of the regolith strongly influences its mechanical properties, as determined from the data on terrestrial sands. The elastoplastic compression volume changes were investigated through oedometer tests that also provided estimates of possible changes in density with depth. The results of direct shear tests provided values of friction angles that were compared with that of a terrestrial sand, and an extrapolation to lower density provided a friction angle compatible with that estimated from previous observations on the surface of Mars. The importance of the contracting/dilating shear volume changes of sands on the dynamic penetration of the mole was determined, with penetration facilitated by the ˜1.3 Mg/m3 density estimated at the landing site. Seismic velocities, measured by means of piezoelectric bender elements in triaxial specimens submitted to various isotropic confining stresses, show the importance of the confining stress, with lesser influence of density changes under compression. A power law relation of velocity as a function of confining stress with an exponent of 0.3 was identified from the tests, allowing an estimate of the surface seismic velocity of 150 m/s. The effect on the seismic velocity of a 10% proportion of rock in the regolith was also studied. These data will be compared with in situ data measured by InSight after landing.

  7. Solutions Network Formulation Report. Landsat Data Continuity Mission Simulated Data Products for Bureau of Land Management and Environmental Protection Agency Abandoned Mine Lands Decision Support

    Science.gov (United States)

    Estep, Leland

    2007-01-01

    Presently, the BLM (Bureau of Land Management) has identified a multitude of abandoned mine sites in primarily Western states for cleanup. These sites are prioritized and appropriate cleanup has been called in to reclaim the sites. The task is great in needing considerable amounts of agency resources. For instance, in Colorado alone there exists an estimated 23,000 abandoned mines. The problem is not limited to Colorado or to the United States. Cooperation for reclamation is sought at local, state, and federal agency level to aid in identification, inventory, and cleanup efforts. Dangers posed by abandoned mines are recognized widely and will tend to increase with time because some of these areas are increasingly used for recreation and, in some cases, have been or are in the process of development. In some cases, mines are often vandalized once they are closed. The perpetrators leave them open, so others can then access the mines without realizing the danger posed. Abandoned mine workings often fill with water or oxygen-deficient air and dangerous gases following mining. If the workings are accidentally entered into, water or bad air can prove fatal to those underground. Moreover, mine residue drainage negatively impacts the local watershed ecology. Some of the major hazards that might be monitored by higher-resolution satellites include acid mine drainage, clogged streams, impoundments, slides, piles, embankments, hazardous equipment or facilities, surface burning, smoke from underground fires, and mine openings.

  8. Simulation of continuously logical base cells (CL BC) with advanced functions for analog-to-digital converters and image processors

    Science.gov (United States)

    Krasilenko, Vladimir G.; Lazarev, Alexander A.; Nikitovich, Diana V.

    2017-10-01

    The paper considers results of design and modeling of continuously logical base cells (CL BC) based on current mirrors (CM) with functions of preliminary analogue and subsequent analogue-digital processing for creating sensor multichannel analog-to-digital converters (SMC ADCs) and image processors (IP). For such with vector or matrix parallel inputs-outputs IP and SMC ADCs it is needed active basic photosensitive cells with an extended electronic circuit, which are considered in paper. Such basic cells and ADCs based on them have a number of advantages: high speed and reliability, simplicity, small power consumption, high integration level for linear and matrix structures. We show design of the CL BC and ADC of photocurrents and their various possible implementations and its simulations. We consider CL BC for methods of selection and rank preprocessing and linear array of ADCs with conversion to binary codes and Gray codes. In contrast to our previous works here we will dwell more on analogue preprocessing schemes for signals of neighboring cells. Let us show how the introduction of simple nodes based on current mirrors extends the range of functions performed by the image processor. Each channel of the structure consists of several digital-analog cells (DC) on 15-35 CMOS. The amount of DC does not exceed the number of digits of the formed code, and for an iteration type, only one cell of DC, complemented by the device of selection and holding (SHD), is required. One channel of ADC with iteration is based on one DC-(G) and SHD, and it has only 35 CMOS transistors. In such ADCs easily parallel code can be realized and also serial-parallel output code. The circuits and simulation results of their design with OrCAD are shown. The supply voltage of the DC is 1.8÷3.3V, the range of an input photocurrent is 0.1÷24μA, the transformation time is 20÷30nS at 6-8 bit binary or Gray codes. The general power consumption of the ADC with iteration is only 50÷100μW, if the

  9. Offshore code comparison collaboration continuation (OC4), phase I - Results of coupled simulations of an offshore wind turbine with jacket support structure

    DEFF Research Database (Denmark)

    Popko, Wojciech; Vorpahl, Fabian; Zuga, Adam

    2012-01-01

    In this paper, the exemplary results of the IEA Wind Task 30 "Offshore Code Comparison Collaboration Continuation" (OC4) Project - Phase I, focused on the coupled simulation of an offshore wind turbine (OWT) with a jacket support structure, are presented. The focus of this task has been the verif......In this paper, the exemplary results of the IEA Wind Task 30 "Offshore Code Comparison Collaboration Continuation" (OC4) Project - Phase I, focused on the coupled simulation of an offshore wind turbine (OWT) with a jacket support structure, are presented. The focus of this task has been...... the verification of OWT modeling codes through code-to-code comparisons. The discrepancies between the results are shown and the sources of the differences are discussed. The importance of the local dynamics of the structure is depicted in the simulation results. Furthermore, attention is given to aspects...

  10. Causal mediation analysis with a binary outcome and multiple continuous or ordinal mediators: Simulations and application to an alcohol intervention

    OpenAIRE

    Nguyen, Trang Quynh; Webb-Vargas, Yenny; Koning, Ina M.; Stuart, Elizabeth A.

    2016-01-01

    We investigate a method to estimate the combined effect of multiple continuous/ordinal mediators on a binary outcome: 1) fit a structural equation model with probit link for the outcome and identity/probit link for continuous/ordinal mediators, 2) predict potential outcome probabilities, and 3) compute natural direct and indirect effects. Step 2 involves rescaling the latent continuous variable underlying the outcome to address residual mediator variance/covariance. We evaluate the estimation...

  11. A Somalia mission experience.

    Science.gov (United States)

    Mahomed, Zeyn; Moolla, Muhammad; Motara, Feroza; Laher, Abdullah

    2012-06-28

    Reports about The Horn of Africa Famine Crisis in 2011 flooded our news bulletins and newspapers. Yet the nations of the world failed to respond and alleviate the unfolding disaster. In August 2011, the Gift of the Givers Foundation mobilised what was to become the largest humanitarian mission ever conducted by an African organisation. Almost a year later, the effort continues, changing the face of disaster medicine as we know it.

  12. Continuous processing of recombinant proteins: Integration of inclusion body solubilization and refolding using simulated moving bed size exclusion chromatography with buffer recycling.

    Science.gov (United States)

    Wellhoefer, Martin; Sprinzl, Wolfgang; Hahn, Rainer; Jungbauer, Alois

    2013-12-06

    An integrated process which combines continuous inclusion body dissolution with NaOH and continuous matrix-assisted refolding based on closed-loop simulated moving bed size exclusion chromatography was designed and experimentally evaluated at laboratory scale. Inclusion bodies from N(pro) fusion pep6His and N(pro) fusion MCP1 from high cell density fermentation were continuously dissolved with NaOH, filtered and mixed with concentrated refolding buffer prior to refolding by size exclusion chromatography (SEC). This process enabled an isocratic operation of the simulated moving bed (SMB) system with a closed-loop set-up with refolding buffer as the desorbent buffer and buffer recycling by concentrating the raffinate using tangential flow filtration. With this continuous refolding process, we increased the refolding and cleavage yield of both model proteins by 10% compared to batch dilution refolding. Furthermore, more than 99% of the refolding buffer of the raffinate could be recycled which reduced the buffer consumption significantly. Based on the actual refolding data, we compared throughput, productivity, and buffer consumption between two batch dilution refolding processes - one using urea for IB dissolution, the other one using NaOH for IB dissolution - and our continuous refolding process. The higher complexity of the continuous refolding process was rewarded with higher throughput and productivity as well as significantly lower buffer consumption compared to the batch dilution refolding processes. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Spacelab life sciences 2 post mission report

    Science.gov (United States)

    Buckey, Jay C.

    1994-01-01

    Jay C. Buckey, M.D., Assistant Professor of Medicine at The University of Texas Southwestern Medical Center at Dallas served as an alternate payload specialist astronaut for the Spacelab Life Sciences 2 Space Shuttle Mission from January 1992 through December 1993. This report summarizes his opinions on the mission and offers suggestions in the areas of selection, training, simulations, baseline data collection and mission operations. The report recognizes the contributions of the commander, payload commander and mission management team to the success of the mission. Dr. Buckey's main accomplishments during the mission are listed.

  14. A decision model for planetary missions

    Science.gov (United States)

    Hazelrigg, G. A., Jr.; Brigadier, W. L.

    1976-01-01

    Many techniques developed for the solution of problems in economics and operations research are directly applicable to problems involving engineering trade-offs. This paper investigates the use of utility theory for decision making in planetary exploration space missions. A decision model is derived that accounts for the objectives of the mission - science - the cost of flying the mission and the risk of mission failure. A simulation methodology for obtaining the probability distribution of science value and costs as a function spacecraft and mission design is presented and an example application of the decision methodology is given for various potential alternatives in a comet Encke mission.

  15. Liquid Effluents Program mission analysis

    International Nuclear Information System (INIS)

    Lowe, S.S.

    1994-01-01

    Systems engineering is being used to identify work to cleanup the Hanford Site. The systems engineering process transforms an identified mission need into a set of performance parameters and a preferred system configuration. Mission analysis is the first step in the process. Mission analysis supports early decision-making by clearly defining the program objectives, and evaluating the feasibility and risks associated with achieving those objectives. The results of the mission analysis provide a consistent basis for subsequent systems engineering work. A mission analysis was performed earlier for the overall Hanford Site. This work was continued by a ''capstone'' team which developed a top-level functional analysis. Continuing in a top-down manner, systems engineering is now being applied at the program and project levels. A mission analysis was conducted for the Liquid Effluents Program. The results are described herein. This report identifies the initial conditions and acceptable final conditions, defines the programmatic and physical interfaces and sources of constraints, estimates the resources to carry out the mission, and establishes measures of success. The mission analysis reflects current program planning for the Liquid Effluents Program as described in Liquid Effluents FY 1995 Multi-Year Program Plan

  16. The effect of long-term confinement and the efficacy of exercise countermeasures on muscle strength during a simulated mission to Mars: data from the Mars500 study.

    Science.gov (United States)

    Gaffney, Christopher J; Fomina, Elena; Babich, Dennis; Kitov, Vladimir; Uskov, Konstantin; Green, David A

    2017-11-13

    Isolation and long duration spaceflight are associated with musculoskeletal deconditioning. Mars500 was a unique, high-fidelity analogue of the psychological challenges of a 520-day manned mission to Mars. We aimed to explore the effect of musculoskeletal deconditioning on three outcome measures: (1) if lower limb muscle strength was reduced during the 520-day isolation; (2) if type I or II muscle fibres were differentially affected; and (3) whether any 70-day exercise interventions prevented any isolation-induced loss of strength. Six healthy male subjects (mean ± SEM) (34 ± 3 years; 1.76 ± 0.02 metres; 83.7 ± 4.8 kg) provided written, informed consent to participate. The subjects' maximal voluntary contraction (MVC) was assessed isometrically in the calf (predominantly type I fibres), and maximal voluntary isokinetic force (MVIF) was assessed in the quadriceps/hamstrings (predominantly type II fibres) at 0.2 and 0.4 ms -1 using the Multifunctional Dynamometer for Space (MDS) at 35-day intervals throughout Mars500. Exercise interventions were completed 3-7 days/week throughout the 520-day isolation in a counterbalanced design excluding 142-177 days (rest period) and 251-284 days (simulated Mars landing). Exercise interventions included motorized treadmill running, non-motorized treadmill running, cycle ergometry, elastomer-based resistance exercise, whole-body vibration (WBV), and resistance exercise using MDS. Calf MVC did not reduce across the 520-day isolation and MDS increased strength by 18% compared to before that of 70-day exercise intervention. In contrast, there was a significant bilateral loss of MVIF across the 520 days at both 0.2 ms -1 (R 2  = 0.53; P = 0.001) and 0.4 ms -1 (0.4 ms -1 ; R 2  = 0.42; P = 0.007). WBV (+ 3.7 and 8.8%) and MDS (+ 4.9 and 5.2%) afforded the best protection against isolation-induced loss of MVIF, although MDS was the only intervention to prevent bilateral loss of calf MVC and leg MVIF at 0

  17. Operational Decision Support for Material Management in Continuous Mining Systems: From Simulation Concept to Practical Full-Scale Implementations

    Directory of Open Access Journals (Sweden)

    Masoud Soleymani Shishvan

    2017-07-01

    Full Text Available Material management in opencast mines is concerned with planning, organizing, and control of the flow of materials from their extraction points to destinations. It can be strongly affected by operational decisions that have to be made during the production process. To date, little research has focused on the application of simulation modeling as a powerful supportive tool for decision making in such systems. Practical experiences from implementing a simulation model of a mine for the operational support on an industrial scale are not known to the authors. This paper presents the extension of a developed stochastic simulation model by the authors from a conceptual stage (TRL4 to a new Technology Readiness Level (TRL 6 by implementing it in an industrially relevant environment. A framework for modeling, simulation, and validation of the simulation model applied to two large opencast lignite mines is presented in detail. Operational implementation issues, experiences, and challenges in practical applications are discussed. Furthermore, the strength of applying the simulation modeling as an operational decision support for material management in coal mining is demonstrated. Results of the case studies are used to describe the details of the framework, and to illustrate the strength and limitations of its application.

  18. Multifractality, imperfect scaling and hydrological properties of rainfall time series simulated by continuous universal multifractal and discrete random cascade models

    Directory of Open Access Journals (Sweden)

    F. Serinaldi

    2010-12-01

    Full Text Available Discrete multiplicative random cascade (MRC models were extensively studied and applied to disaggregate rainfall data, thanks to their formal simplicity and the small number of involved parameters. Focusing on temporal disaggregation, the rationale of these models is based on multiplying the value assumed by a physical attribute (e.g., rainfall intensity at a given time scale L, by a suitable number b of random weights, to obtain b attribute values corresponding to statistically plausible observations at a smaller L/b time resolution. In the original formulation of the MRC models, the random weights were assumed to be independent and identically distributed. However, for several studies this hypothesis did not appear to be realistic for the observed rainfall series as the distribution of the weights was shown to depend on the space-time scale and rainfall intensity. Since these findings contrast with the scale invariance assumption behind the MRC models and impact on the applicability of these models, it is worth studying their nature. This study explores the possible presence of dependence of the parameters of two discrete MRC models on rainfall intensity and time scale, by analyzing point rainfall series with 5-min time resolution. Taking into account a discrete microcanonical (MC model based on beta distribution and a discrete canonical beta-logstable (BLS, the analysis points out that the relations between the parameters and rainfall intensity across the time scales are detectable and can be modeled by a set of simple functions accounting for the parameter-rainfall intensity relationship, and another set describing the link between the parameters and the time scale. Therefore, MC and BLS models were modified to explicitly account for these relationships and compared with the continuous in scale universal multifractal (CUM model, which is used as a physically based benchmark model. Monte Carlo simulations point out

  19. Sociometric and ethological approach to the assessment of individual and group behavior in extra long-term isolation during simulated interplanetary mission

    Science.gov (United States)

    Gushin, Vadim; Tafforin, Carole; Kuznetsova, Polina; Vinokhodova, Alla; Chekalina, Angelina

    Several factors, such as hazard to life, reduced social communications, isolation, high workload, monotony, etc., can cause deconditioning of individual status and group dynamics in long-term spaceflight. New approaches to the assessment of group behavior are being developed in order to create necessary counter-measures and to keep optimal psychological climate in the crew. Psychological methods combined with ethological approach to dynamic monitoring of the isolated crew had been tested and validated in Mars-500 experiment. The experiment (duration of 520 days) was designed to simulate the living and working conditions of a piloted mission to Mars. The Mars-500 crew was composed of three Russians, two Europeans and one Chinese. We used psychological tests: sociometric questionnaire to assess group status (popularity) of the crewmembers (monthly), color choice test to assess the level of frustration and anxiety (twice a month). We performed observations from video recordings of group discussions (monthly) and during breakfast time (twice a month). The video analysis was supplied with a software based-solution: The Observer XT®. The results showed that occurrence of collateral acts may indicate psychological stress and fatigue in crewmembers under isolation and that facial expressions may indicate less anxiety. The data of psychological tests allowed to define two subgroups in the crew. The first one consisted of the subjects with high group status and lower level of frustration (not anxious), the second one consisted of less popular subjects, having respectively higher anxiety level. The video analysis showed two times more manifestations of facial expressions and interpersonal communications for the first subgroup. We also identified the subgroups on the basis of their verbal expressions in Russian and in English. Video observation of individual and group behavior, combined with other psychological tests gives opportunity to emphasize more objectively the signs

  20. Startup and operation of a plant-scale continuous glass melter for vitrification of Savannah River Plant simulated waste

    International Nuclear Information System (INIS)

    Willis, T.A.

    1980-01-01

    The reference process for disposal of radioactive waste from the Savannah River Plant is vitrification of the waste in borosilicate glass in a continuous glass melter. Design, startup, and operation of a plant-scale developmental melter system are discussed

  1. The Effects of Modafinil on Aviator Performance During 40 Hours of Continuous Wakefulness: A UH-60 Helicopter Simulator Study

    National Research Council Canada - National Science Library

    Caidwell, John

    1999-01-01

    ...) activation in helicopter pilots who had been deprived of sleep. Six Army helicopter pilots were each exposed to two 40-hour periods of continuous wakefulness separated by one night of recovery sleep...

  2. Simulation, design and proof-of-concept of a two-stage continuous hydrothermal flow synthesis reactor for synthesis of functionalized nano-sized inorganic composite materials

    DEFF Research Database (Denmark)

    Zielke, Philipp; Xu, Yu; Simonsen, Søren Bredmose

    2016-01-01

    Computational fluid dynamics simulations were employed to evaluate several mixer geometries for a novel two-stage continuous hydrothermal flow synthesis reactor. The addition of a second stage holds the promise of allowing the synthesis of functionalized nano-materials as for example core-shell...... or decorated particles. Based on the simulation results, a reactor system employing a confined jet mixer in the first and a counter-flow mixer in the second stage was designed and built. The two-stage functionality and synthesis capacity is shown on the example of single- and two-stage syntheses of pure...... and mixed-phase NiO and YSZ particles....

  3. Simulations

    CERN Document Server

    Ngada, Narcisse

    2015-06-15

    The complexity and cost of building and running high-power electrical systems make the use of simulations unavoidable. The simulations available today provide great understanding about how systems really operate. This paper helps the reader to gain an insight into simulation in the field of power converters for particle accelerators. Starting with the definition and basic principles of simulation, two simulation types, as well as their leading tools, are presented: analog and numerical simulations. Some practical applications of each simulation type are also considered. The final conclusion then summarizes the main important items to keep in mind before opting for a simulation tool or before performing a simulation.

  4. The Ulysses mission: An introduction

    International Nuclear Information System (INIS)

    Marsden, R.G.

    1996-01-01

    On 30 September 1995, Ulysses completed its initial, highly successful, survey of the polar regions of the heliosphere in both southern and northern hemispheres, thereby fulfilling its prime mission. The results obtained to date are leading to a revision of many earlier ideas concerning the solar wind and the heliosphere. Now embarking on the second phase of the mission, Ulysses will continue along its out-of-ecliptic flight path for another complete orbit of the Sun. In contrast to the high-latitude phase of the prime mission, which occurred near solar minimum, the next polar passes (in 2000 and 2001) will take place when the Sun is at its most active

  5. Causal mediation analysis with a binary outcome and multiple continuous or ordinal mediators: Simulations and application to an alcohol intervention.

    Science.gov (United States)

    Nguyen, Trang Quynh; Webb-Vargas, Yenny; Koning, Ina M; Stuart, Elizabeth A

    We investigate a method to estimate the combined effect of multiple continuous/ordinal mediators on a binary outcome: 1) fit a structural equation model with probit link for the outcome and identity/probit link for continuous/ordinal mediators, 2) predict potential outcome probabilities, and 3) compute natural direct and indirect effects. Step 2 involves rescaling the latent continuous variable underlying the outcome to address residual mediator variance/covariance. We evaluate the estimation of risk-difference- and risk-ratio-based effects (RDs, RRs) using the ML, WLSMV and Bayes estimators in Mplus. Across most variations in path-coefficient and mediator-residual-correlation signs and strengths, and confounding situations investigated, the method performs well with all estimators, but favors ML/WLSMV for RDs with continuous mediators, and Bayes for RRs with ordinal mediators. Bayes outperforms WLSMV/ML regardless of mediator type when estimating RRs with small potential outcome probabilities and in two other special cases. An adolescent alcohol prevention study is used for illustration.

  6. In-line monitoring and optimization of powder flow in a simulated continuous process using transmission near infrared spectroscopy.

    Science.gov (United States)

    Alam, Md Anik; Shi, Zhenqi; Drennen, James K; Anderson, Carl A

    2017-06-30

    In-line monitoring of continuous powder flow is an integral part of the continuous manufacturing process of solid oral dosage forms in the pharmaceutical industry. Specifically, monitoring downstream from loss-in-weight (LIW) feeders and/or continuous mixers provides important data about the state of the process. Such measurements support control of the process and thereby enhance product quality. Near Infrared Spectroscopy (NIRS) is a potential PAT tool to monitor the homogeneity of a continuous powder flow stream in pharmaceutical manufacturing. However, the association of analytical results from NIR sampling of the powder stream and the homogeneity (content uniformity) of the resulting tablets provides several challenges; appropriate sampling strategies, adequately robust modeling techniques and poor sensitivities (for low dose APIs) are amongst them. Information from reflectance-based NIRS sampling is limited. The region of the powder bed that is interrogated is confined to the surface where the measurement is made. This potential bias in sampling may, in turn, limit the ability to predict the homogeneity of the finished dosage form. Further, changes to the processing parameters (e.g., rate of powder flow) often have a significant effect on the resulting data. Sample representation, interdependence between process parameters and their effects on powder flow behavior are critical factors for NIRS monitoring of continuous powder flow system. A transmission NIR method was developed as an alternative technique to monitor continuous powder flow and quantify API in the powder stream. Transmission NIRS was used to determine the thickness of the powder stream flowing from a loss-in-weight feeder. The thickness measurement of the powder stream provided an in-depth understanding about the effects of process parameters such as tube angles and powder flow rates on powder flow behaviors. This knowledge based approach helped to define an analytical design space that was

  7. Analysis of the Accuracy and Performance of a Continuous Glucose Monitoring Sensor Prototype: An In-Silico Study Using the UVA/PADOVA Type 1 Diabetes Simulator.

    Science.gov (United States)

    Breton, Marc D; Hinzmann, Rolf; Campos-Nañez, Enrique; Riddle, Susan; Schoemaker, Michael; Schmelzeisen-Redeker, Guenther

    2017-05-01

    Computer simulation has been shown over the past decade to be a powerful tool to study the impact of medical devices characteristics on clinical outcomes. Specifically, in type 1 diabetes (T1D), computer simulation platforms have all but replaced preclinical studies and are commonly used to study the impact of measurement errors on glycemia. We use complex mathematical models to represent the characteristics of 3 continuous glucose monitoring systems using previously acquired data. Leveraging these models within the framework of the UVa/Padova T1D simulator, we study the impact of CGM errors in 6 simulation scenarios designed to generate a wide variety of glycemic conditions. Assessment of the simulated accuracy of each different CGM systems is performed using mean absolute relative deviation (MARD) and precision absolute relative deviation (PARD). We also quantify the capacity of each system to detect hypoglycemic events. The simulated Roche CGM sensor prototype (RCGM) outperformed the 2 alternate systems (CGM-1 & CGM-2) in accuracy (MARD = 8% vs 11.4% vs 18%) and precision (PARD = 6.4% vs 9.4% vs 14.1%). These results held for all studied glucose and rate of change ranges. Moreover, it detected more than 90% of hypoglycemia, with a mean time lag less than 4 minutes (CGM-1: 86%/15 min, CGM-2: 57%/24 min). The RCGM system model led to strong performances in these simulation studies, with higher accuracy and precision than alternate systems. Its characteristics placed it firmly as a strong candidate for CGM based therapy, and should be confirmed in large clinical studies.

  8. Evaluation of a continuous indicator for syndromic surveillance through simulation. application to vector borne disease emergence detection in cattle using milk yield.

    Directory of Open Access Journals (Sweden)

    Aurélien Madouasse

    Full Text Available Two vector borne diseases, caused by the Bluetongue and Schmallenberg viruses respectively, have emerged in the European ruminant populations since 2006. Several diseases are transmitted by the same vectors and could emerge in the future. Syndromic surveillance, which consists in the routine monitoring of indicators for the detection of adverse health events, may allow an early detection. Milk yield is routinely measured in a large proportion of dairy herds and could be incorporated as an indicator in a surveillance system. However, few studies have evaluated continuous indicators for syndromic surveillance. The aim of this study was to develop a framework for the quantification of both disease characteristics and model predictive abilities that are important for a continuous indicator to be sensitive, timely and specific for the detection of a vector-borne disease emergence. Emergences with a range of spread characteristics and effects on milk production were simulated. Milk yields collected monthly in 48 713 French dairy herds were used to simulate 576 disease emergence scenarios. First, the effect of disease characteristics on the sensitivity and timeliness of detection were assessed: Spatio-temporal clusters of low milk production were detected with a scan statistic using the difference between observed and simulated milk yields as input. In a second step, the system specificity was evaluated by running the scan statistic on the difference between observed and predicted milk yields, in the absence of simulated emergence. The timeliness of detection depended mostly on how easily the disease spread between and within herds. The time and location of the emergence or adding random noise to the simulated effects had a limited impact on the timeliness of detection. The main limitation of the system was the low specificity i.e. the high number of clusters detected from the difference between observed and predicted productions, in the absence of

  9. Simulation from endpoint-conditioned, continuous-time Markov chains on a finite state space, with applications to molecular evolution

    DEFF Research Database (Denmark)

    Hobolth, Asger; Stone, Eric

    2009-01-01

    computational finance to human genetics and genomics. A common theme among these diverse applications is the need to simulate sample paths of a CTMC conditional on realized data that is discretely observed. Here we present a general solution to this sampling problem when the CTMC is defined on a discrete....... In doing so, we show that no method dominates the others across all model specifications, and we give explicit proof of which method prevails for any given Q, T, and endpoints. Finally, we introduce and compare three applications of CTMCs to demonstrate the pitfalls of choosing an inefficient sampler....

  10. GRACE Status at Mission End

    Science.gov (United States)

    Tapley, B. D.; Flechtner, F. M.; Watkins, M. M.; Bettadpur, S. V.

    2017-12-01

    The twin satellites of the Gravity Recovery and Climate Experiment (GRACE) were launched on March 17, 2002 and have operated for nearly 16 years. The mission objectives are to observe the spatial and temporal variations of the Earth's mass through its effects on the gravity field at the GRACE satellite altitude. The mass changes observed are related to both the changes within the solid earth and the change within and between the Erath system components. A significant cause of the time varying mass is water motion and the GRACE mission has provided a continuous decade long measurement sequence which characterizes the seasonal cycle of mass transport between the oceans, land, cryosphere and atmosphere; its inter-annual variability; and the climate driven secular, or long period, mass transport signals. The fifth reanalysis on the mission data set, the RL05 data, were released in mid-2013. With the planned launch of GRACE Follow-On in early 2018, plans are underway for a reanalysis that will be consistent with the GRACE FO processing standards. The mission is entering the final phases of its operation life with mission end expected to occur in early 2018. The current mission operations strategy emphasizes extending the mission lifetime to obtain an overlap with the GRACE FO. This presentation will review the mission status and the projections for mission lifetime, describe the current operations philosophy and its impact on the science data, discuss the issues related to achieving the GRACE and GRACE FO connection and discuss issues related to science data products during this phase of the mission period.

  11. Ratio of geometric means to analyze continuous outcomes in meta-analysis: comparison to mean differences and ratio of arithmetic means using empiric data and simulation.

    Science.gov (United States)

    Friedrich, Jan O; Adhikari, Neill K J; Beyene, Joseph

    2012-07-30

    Meta-analyses pooling continuous outcomes can use mean differences (MD), standardized MD (MD in pooled standard deviation units, SMD), or ratio of arithmetic means (RoM). Recently, ratio of geometric means using ad hoc (RoGM (ad hoc) ) or Taylor series (RoGM (Taylor) ) methods for estimating variances have been proposed as alternative effect measures for skewed continuous data. Skewed data are suggested for summary measures of clinical parameters restricted to positive values which have large coefficients of variation (CV). Our objective was to compare performance characteristics of RoGM (ad hoc) and RoGM (Taylor) to MD, SMD, and RoM. We used empiric data from systematic reviews reporting continuous outcomes and selected from each the meta-analysis with the most and at least 5 trials (Cochrane Database [2008, Issue 1]). We supplemented this with simulations conducted with representative parameters. Pooled results were calculated using each effect measure. Of the reviews, 232/5053 met the inclusion criteria. Empiric data and simulation showed that RoGM (ad hoc) exhibits more extreme treatment effects and greater heterogeneity than all other effect measures. Compared with MD, SMD, and RoM, RoGM (Taylor) exhibits similar treatment effects, more heterogeneity when CV ≤0.7, and less heterogeneity when CV > 0.7. In conclusion, RoGM (Taylor) may be considered for pooling continuous outcomes in meta-analysis when data are skewed, but RoGM (ad hoc) should not be used. However, clinicians' lack of familiarity with geometric means combined with acceptable performance characteristics of RoM in most situations suggests that RoM may be the preferable ratio method for pooling continuous outcomes in meta-analysis. Copyright © 2012 John Wiley & Sons, Ltd.

  12. Mars Analog Research and Technology Experiment (MARTE): A Simulated Mars Drilling Mission to Search for Subsurface Life at the Rio Tinto, Spain

    Science.gov (United States)

    Stoker, Carol; Lemke, Larry; Mandell, Humboldt; McKay, David; George, Jeffrey; Gomez-Alvera, Javier; Amils, Ricardo; Stevens, Todd; Miller, David

    2003-01-01

    The MARTE (Mars Astrobiology Research and Technology Experiment) project was selected by the new NASA ASTEP program, which supports field experiments having an equal emphasis on Astrobiology science and technology development relevant to future Astrobiology missions. MARTE will search for a hypothesized subsurface anaerobic chemoautotrophic biosphere in the region of the Tinto River in southwestern Spain while also demonstrating technology needed to search for a subsurface biosphere on Mars. The experiment is informed by the strategy for searching for life on Mars.

  13. Dynamic bioconversion mathematical modelling and simulation of urban organic waste co-digestion in continuously stirred tank reactor

    DEFF Research Database (Denmark)

    Fitamo, Temesgen Mathewos; Boldrin, Alessio; Dorini, G.

    of this study was to apply a dynamic mathematical model to simulate the co-digestion of different urban organic wastes (UOW). The modelling was based on experimental activities, during which two reactors (R1, R2) were operated at hydraulic retention times (HRT) of 30, 20, 15, 10 days, in thermophilic conditions......The application of anaerobic digestion (AD) as process technology is increasing worldwide: the production of biogas, a versatile form of renewable energy, from biomass and organic waste materials allows mitigating greenhouse gas emission from the energy and transportation sectors while treating...... waste. However, the successful operation of AD processes is challenged by economic and technological issues. To overcome these barriers, mathematical modelling of the bioconversion process can provide support to develop strategies for controlling and optimizing the AD process. The objective...

  14. Reaction-transport simulations of non-oxidative methane conversion with continuous hydrogen removal: Homogeneous-heterogeneous methane reaction pathways

    International Nuclear Information System (INIS)

    Li, Lin; Borry, Richard W.; Iglesia, Enrique

    2000-01-01

    Detailed kinetic-transport models were used to explore thermodynamic and kinetic barriers in the non-oxidative conversion of CH4 via homogeneous and homogeneous-heterogeneous pathways and the effects of continuous hydrogen removal and of catalytic sites on attainable yields of useful C2-C10 products. The homogeneous kinetic model combines separately developed models for low-conversion pyrolysis and for chain growth to form large aromatics and carbon. The H2 formed in the reaction decreases CH4 pyrolysis rates and equilibrium conversions and it favors the formation of lighter products. The removal of H2 along tubular reactors with permeable walls increases reaction rates and equilibrium CH4 conversions. C2-C10 yields reach values greater than 90 percent at intermediate values of dimensionless transport rates (delta=1-10), defined as the ratio hydrogen transport and methane conversion rates. Homogeneous reactions require impractical residence times, even with H2 removal, because of slow initiation and chain transfer rates. The introduction of heterogeneous chain initiation pathways using surface sites that form methyl radicals eliminates the induction period without influencing the homogeneous product distribution. Methane conversion, however, occurs predominately in the chain transfer regime, within which individual transfer steps and the formation of C2 intermediates become limited by thermodynamic constraints. Catalytic sites alone cannot overcome these constraints. Catalytic membrane reactors with continuous H2 removal remove these thermodynamic obstacles and decrease the required residence time. Reaction rates become limited by homogeneous reactions of C2 products to form C6+ aromatics. Higher delta values lead to subsequent conversion of the desired C2-C10 products to larger polynuclear aromatics. We conclude that catalytic methane pyrolysis at the low temperatures required for restricted chain growth and the elimination of thermodynamics constraints via

  15. A Mission Planning Approach for Precision Farming Systems Based on Multi-Objective Optimization

    Directory of Open Access Journals (Sweden)

    Zhaoyu Zhai

    2018-06-01

    Full Text Available As the demand for food grows continuously, intelligent agriculture has drawn much attention due to its capability of producing great quantities of food efficiently. The main purpose of intelligent agriculture is to plan agricultural missions properly and use limited resources reasonably with minor human intervention. This paper proposes a Precision Farming System (PFS as a Multi-Agent System (MAS. Components of PFS are treated as agents with different functionalities. These agents could form several coalitions to complete the complex agricultural missions cooperatively. In PFS, mission planning should consider several criteria, like expected benefit, energy consumption or equipment loss. Hence, mission planning could be treated as a Multi-objective Optimization Problem (MOP. In order to solve MOP, an improved algorithm, MP-PSOGA, is proposed, taking advantages of the Genetic Algorithms and Particle Swarm Optimization. A simulation, called precise pesticide spraying mission, is performed to verify the feasibility of the proposed approach. Simulation results illustrate that the proposed approach works properly. This approach enables the PFS to plan missions and allocate scarce resources efficiently. The theoretical analysis and simulation is a good foundation for the future study. Once the proposed approach is applied to a real scenario, it is expected to bring significant economic improvement.

  16. Development of a continuous motorcycle protection barrier system using computer simulation and full-scale crash testing.

    Science.gov (United States)

    Atahan, Ali O; Hiekmann, J Marten; Himpe, Jeffrey; Marra, Joseph

    2018-07-01

    Road restraint systems are designed to minimize the undesirable effects of roadside accidents and improve safety of road users. These systems are utilized at either side or median section of roads to contain and redirect errant vehicles. Although restraint systems are mainly designed against car, truck and bus impacts there is an increasing pressure by the motorcycle industry to incorporate motorcycle protection systems into these systems. In this paper development details of a new and versatile motorcycle barrier, CMPS, coupled with an existing vehicle barrier is presented. CMPS is intended to safely contain and redirect motorcyclists during a collision event. First, crash performance of CMPS design is evaluated by means of a three dimensional computer simulation program LS-DYNA. Then full-scale crash tests are used to verify the acceptability of CMPS design. Crash tests were performed at CSI proving ground facility using a motorcycle dummy in accordance with prEN 1317-8 specification. Full-scale crash test results show that CMPS is able to successfully contain and redirect dummy with minimal injury risk on the dummy. Damage on the barrier is also minimal proving the robustness of the CMPS design. Based on the test findings and further review by the authorities the implementation of CMPS was recommended at highway system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Designing and simulation smart multifunctional continuous logic device as a basic cell of advanced high-performance sensor systems with MIMO-structure

    Science.gov (United States)

    Krasilenko, Vladimir G.; Nikolskyy, Aleksandr I.; Lazarev, Alexander A.

    2015-01-01

    We have proposed a design and simulation of hardware realizations of smart multifunctional continuous logic devices (SMCLD) as advanced basic cells of the sensor systems with MIMO- structure for images processing and interconnection. The SMCLD realize function of two-valued, multi-valued and continuous logics with current inputs and current outputs. Such advanced basic cells realize function nonlinear time-pulse transformation, analog-to-digital converters and neural logic. We showed advantages of such elements. It's have a number of advantages: high speed and reliability, simplicity, small power consumption, high integration level. The conception of construction of SMCLD consists in the use of a current mirrors realized on 1.5μm technology CMOS transistors. Presence of 50÷70 transistors, 1 PD and 1 LED makes the offered circuits quite compact. The simulation results of NOT, MIN, MAX, equivalence (EQ), normalize summation, averaging and other functions, that implemented SMCLD, showed that the level of logical variables can change from 0.1μA to 10μA for low-power consumption variants. The SMCLD have low power consumption <1mW and processing time about 1÷11μS at supply voltage 2.4÷3.3V.

  18. Stormwater Tank Performance: Design and Management Criteria for Capture Tanks Using a Continuous Simulation and a Semi-Probabilistic Analytical Approach

    Directory of Open Access Journals (Sweden)

    Flavio De Martino

    2013-10-01

    Full Text Available Stormwater tank performance significantly depends on management practices. This paper proposes a procedure to assess tank efficiency in terms of volume and pollutant concentration using four different capture tank management protocols. The comparison of the efficiency results reveals that, as expected, a combined bypass—stormwater tank system achieves better results than a tank alone. The management practices tested for the tank-only systems provide notably different efficiency results. The practice of immediately emptying after the end of the event exhibits significant levels of efficiency and operational advantages. All other configurations exhibit either significant operational problems or very low performances. The continuous simulation and semi-probabilistic approach for the best tank management practice are compared. The semi-probabilistic approach is based on a Weibull probabilistic model of the main characteristics of the rainfall process. Following this approach, efficiency indexes were established. The comparison with continuous simulations shows the reliability of the probabilistic approach even if this last is certainly very site sensitive.

  19. The mechanical properties and microstructures of vanadium bearing high strength dual phase steels processed with continuous galvanizing line simulations

    Science.gov (United States)

    Gong, Yu

    For galvanized or galvannealed steels to be commercially successful, they must exhibit several attributes: (i) easy and inexpensive processing in the hot mill, cold mill and on the coating line, (ii) high strength with good formability and spot weldability, and (iii) good corrosion resistance. At the beginning of this thesis, compositions with a common base but containing various additions of V or Nb with or without high N were designed and subjected to Gleeble simulations of different galvanizing(GI), galvannealing(GA) and supercooling processing. The results revealed the phase balance was strongly influenced by the different microalloying additions, while the strengths of each phase were somewhat less affected. Our research revealed that the amount of austenite formed during intercritical annealing can be strongly influenced by the annealing temperature and the pre-annealing conditions of the hot band (coiling temperature) and cold band (% cold reduction). In the late part of this thesis, the base composition was a low carbon steel which would exhibit good spot weldability. To this steel were added two levels of Cr and Mo for strengthening the ferrite and increasing the hardenability of intercritically formed austenite. Also, these steels were produced with and without the addition of vanadium in an effort to further increase the strength. Since earlier studies revealed a relationship between the nature of the starting cold rolled microstructure and the response to CGL processing, the variables of hot band coiling temperature and level of cold reduction prior to annealing were also studied. Finally, in an effort to increase strength and ductility of both the final sheet (general formability) and the sheared edges of cold punched holes (local formability), a new thermal path was developed that replaced the conventional GI ferrite-martensite microstructure with a new ferrite-martensite-tempered martensite and retained austenite microstructure. The new

  20. Distributed Mission Operations Within-Simulator Training Effectiveness Baseline Study. Volume 5. Using the Pathfinder Methodology to Assess Pilot Knowledge Structure Changes

    National Research Council Canada - National Science Library

    Schreiber, Brian T; DiSalvo, Pam; Stock, William A; Bennett, Jr., Winston

    2006-01-01

    ...) Within Simulator Training Effectiveness Baseline Study as described in Volume I, Summary Report, of AFRL-HE-AZ-TR-2006-0015, the current work examined pilots who participated in a Pathfinder data...

  1. Evaluating the Impacts of Mission Training via Distributed Simulation on Live Exercise Performance: Results from the US/UK "Red Skies" Study

    National Research Council Canada - National Science Library

    Smith, Ebb; McIntyre, Heather; Gehr, Sara E; Schurig, Margaret; Symons, Steve; Schreiber, Brian; Bennett Jr., Winston

    2007-01-01

    .... The most recent collaborative study, named "Red Skies" involved extending our work to include field assessments of the training benefits derived from involvement in a simulation-based distributed...

  2. Continuous processing of recombinant proteins: integration of refolding and purification using simulated moving bed size-exclusion chromatography with buffer recycling.

    Science.gov (United States)

    Wellhoefer, Martin; Sprinzl, Wolfgang; Hahn, Rainer; Jungbauer, Alois

    2014-04-11

    Continuous processing of recombinant proteins was accomplished by combining continuous matrix-assisted refolding and purification by tandem simulated moving bed (SMB) size-exclusion chromatography (SEC). Recombinant proteins, N(pro) fusion proteins from inclusion bodies were dissolved with NaOH and refolded in the SMB system with a closed-loop set-up with refolding buffer as the desorbent buffer and buffer recycling of the refolding buffer of the raffinate by tangential flow filtration. For further purification of the refolded proteins, a second SMB operation also based on SEC was added. The whole system could be operated isocratically with refolding buffer as the desorbent buffer, and buffer recycling could also be applied in the purification step. Thus, a significant reduction in buffer consumption was achieved. The system was evaluated with two proteins, the N(pro) fusion pep6His and N(pro) fusion MCP-1. Refolding solution, which contained residual N(pro) fusion peptide, the cleaved autoprotease N(pro), and the cleaved target peptide was used as feed solution. Full separation of the cleaved target peptide from residual proteins was achieved at a purity and recovery in the raffinate and extract, respectively, of approximately 100%. In addition, more than 99% of the refolding buffer of the raffinate was recycled. A comparison of throughput, productivity, and buffer consumption of the integrated continuous process with two batch processes demonstrated that up to 60-fold higher throughput, up to 180-fold higher productivity, and at least 28-fold lower buffer consumption can be obtained by the integrated continuous process, which compensates for the higher complexity. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Continuity and Change.

    Science.gov (United States)

    Istance, David

    1985-01-01

    Examines issues related to continuity in education and educational change. Indicates that although schools must be responsive to changing social and economic conditions (and contribute to them), they must also be protected against fluctuating swings of educational fashion and safeguard their long-term mission, even when buffeted by short-term…

  4. STS payloads mission control study. Volume 2-A, Task 1: Joint products and functions for preflight planning of flight operations, training and simulations

    Science.gov (United States)

    1976-01-01

    Specific products and functions, and associated facility availability, applicable to preflight planning of flight operations were studied. Training and simulation activities involving joint participation of STS and payload operations organizations, are defined. The prelaunch activities required to prepare for the payload flight operations are emphasized.

  5. DEPSCOR: Research on ARL's Intelligent Control Architecture: Hierarchical Hybrid-Model Based Design, Verification, Simulation, and Synthesis of Mission Control for Autonomous Underwater Vehicles

    National Research Council Canada - National Science Library

    Kumar, Ratnesh; Holloway, Lawrence E

    2007-01-01

    ... modeling, verification, simulation and automated synthesis of coordinators has lead to research in this area. We have worked and are working on these issues with Applied Research Laboratory (ARL) at Pennsylvania State University (PSU) who have designed autonomous underwater vehicles for over 50 years primarily under the support of the U.S. Navy through the Office of Naval Research (ONR).

  6. Simulation

    DEFF Research Database (Denmark)

    Gould, Derek A; Chalmers, Nicholas; Johnson, Sheena J

    2012-01-01

    Recognition of the many limitations of traditional apprenticeship training is driving new approaches to learning medical procedural skills. Among simulation technologies and methods available today, computer-based systems are topical and bring the benefits of automated, repeatable, and reliable p...... performance assessments. Human factors research is central to simulator model development that is relevant to real-world imaging-guided interventional tasks and to the credentialing programs in which it would be used....

  7. Mathematical simulation of two-phase flow inside the physical model of continuous casting tundish: STUDY OF THE DAM SUBSTITUTION BY THE GAS CURT

    Directory of Open Access Journals (Sweden)

    Leonardo Neves

    2015-03-01

    Full Text Available Continuous casting is a solidification process, in which the knowledge about its variables is very important in order to produce steel with good quality. The tundish distributes the steel coming from the ladle to the metallurgical mold as the traditional function, besides, it also has some other important functions. Because of its importance in the process, this work aim to carry out studies on the steel flow in the tundish with two different configurations, with and without inert gas injection. A Computational Fluid Dynamic (CFD software were used to make the mathematical simulations making possible to note the difference in terms of the Residence Time Distribution curves (RTD curves, levels of turbulence and velocity profiles with or without inert gas injection

  8. A maintenance optimization model for mission-oriented systems based on Wiener degradation

    International Nuclear Information System (INIS)

    Guo, Chiming; Wang, Wenbin; Guo, Bo; Si, Xiaosheng

    2013-01-01

    Over the past few decades, condition-based maintenance (CBM) has attracted many researchers because of its effectiveness and practical significance. This paper deals with mission-oriented systems subject to gradual degradation modeled by a Wiener stochastic process within the context of CBM. For a mission-oriented system, the mission usually has constraints on availability/reliability, the opportunity for maintenance actions, and the monitoring type (continuous or discrete). Furthermore, in practice, a mission-oriented system may undertake some preventive maintenance (PM) and after such PM, the system may return to an intermediate state between an as-good-as new state and an as-bad-as old state, i.e., the PM is not perfect and only partially restores the system. However, very few CBM models integrated these mission constraints together with an imperfect nature of the PM into the course of optimizing the PM policy. This paper develops a model to optimize the PM policy in terms of the maintenance related cost jointly considering the mission constraints and the imperfect PM nature. A numerical example is presented to demonstrate the proposed model. The comparison with the simulated results and the sensitivity analysis show the usefulness of the optimization model for mission-oriented system maintenance presented in this paper.

  9. A 2D modeling approach for fluid propagation during FE-forming simulation of continuously reinforced composites in wet compression moulding

    Science.gov (United States)

    Poppe, Christian; Dörr, Dominik; Henning, Frank; Kärger, Luise

    2018-05-01

    Wet compression moulding (WCM) provides large-scale production potential for continuously fiber reinforced components as a promising alternative to resin transfer moulding (RTM). Lower cycle times are possible due to parallelization of the process steps draping, infiltration and curing during moulding (viscous draping). Experimental and theoretical investigations indicate a strong mutual dependency between the physical mechanisms, which occur during draping and mould filling (fluid-structure-interaction). Thus, key process parameters, like fiber orientation, fiber volume fraction, cavity pressure and the amount and viscosity of the resin are physically coupled. To enable time and cost efficient product and process development throughout all design stages, accurate process simulation tools are desirable. Separated draping and mould filling simulation models, as appropriate for the sequential RTM-process, cannot be applied for the WCM process due to the above outlined physical couplings. Within this study, a two-dimensional Darcy-Propagation-Element (DPE-2D) based on a finite element formulation with additional control volumes (FE/CV) is presented, verified and applied to forming simulation of a generic geometry, as a first step towards a fluid-structure-interaction model taking into account simultaneous resin infiltration and draping. The model is implemented in the commercial FE-Solver Abaqus by means of several user subroutines considering simultaneous draping and 2D-infiltration mechanisms. Darcy's equation is solved with respect to a local fiber orientation. Furthermore, the material model can access the local fluid domain properties to update the mechanical forming material parameter, which enables further investigations on the coupled physical mechanisms.

  10. Continuous Curvilinear Capsulorhexis Training and Non-Rhexis Related Vitreous Loss: The Specificity of Virtual Reality Simulator Surgical Training (An American Ophthalmological Society Thesis).

    Science.gov (United States)

    McCannel, Colin A

    2017-08-01

    To assess the specificity of simulation-based virtual reality ophthalmic cataract surgery training on the Eyesi ophthalmic virtual reality surgical simulator, and test the hypothesis that microsurgical motor learning is highly specific. Retrospective educational interventional case series. The rates of vitreous loss and retained lens material, and vitreous loss and retained lens material associated with an errant continuous curvilinear capsulorhexis (CCC) were assessed among 1037 consecutive cataract surgeries performed during four consecutive academic years at a teaching hospital. The data were grouped by Eyesi use and capsulorhexis intensive training curriculum (CITC) completion. The main intervention was the completion of the CITC on the Eyesi. In the Eyesi simulator experience-based stratification, the vitreous loss rate was similar in each group (chi square p=0.95) and was not preceded by an errant CCC in 86.2% for "CITC done at least once", 57.1% for "CITC not done, but some Eyesi use", and 48.9% for "none" training groups (p=4×10-5). Retained lens material overall and occurring among the errant CCC cases was similar among training groups (p=0.82 and p=0.71, respectively). Eyesi capsulorhexis training was not associated with lower vitreous loss rates overall. However, non-errant CCC associated vitreous loss was higher among those who underwent Eyesi capsulorhexis training. Training focused on the CCC portion of cataract surgery may not reduce vitreous loss unassociated with an errant CCC. It is likely that surgical training is highly specific to the task being trained. Residents may need to be trained for all surgical steps with adequate intensity to minimize overall complication rates.

  11. Simulation

    CERN Document Server

    Ross, Sheldon

    2006-01-01

    Ross's Simulation, Fourth Edition introduces aspiring and practicing actuaries, engineers, computer scientists and others to the practical aspects of constructing computerized simulation studies to analyze and interpret real phenomena. Readers learn to apply results of these analyses to problems in a wide variety of fields to obtain effective, accurate solutions and make predictions about future outcomes. This text explains how a computer can be used to generate random numbers, and how to use these random numbers to generate the behavior of a stochastic model over time. It presents the statist

  12. The ENVISAT Atmospheric Chemistry mission (GOMOS, MIPAS and SCIAMACHY) -Instrument status and mission evolution

    Science.gov (United States)

    Dehn, Angelika

    The ENVISAT ESA's satellite was launched on a polar orbit on March 2002. It carries on-board three atmospheric chemistry instruments: GOMOS, MIPAS and SCIAMACHY [1]. At the present time, although the mission expected lifetime of 5 years has been already exceeded, all the payload modules are in good to excellent status. The only limiting factor is the available fuel that is used for orbit control manoeuvre. A new strategy was proposed [2] that will allow to save fuel and to extend the mission up to 2013. Following this strategy, the altitude of the orbit will be lowered by 17 km starting from end of 2010 and the inclination will be allowed to drift. The new orbit scenario will result in a new repeating cycle with a variation of the Mean Local Solar Time (MLST). This will have an impact on both the in-flight operations, on the science data and on the mission. The simulations carried out for the atmospheric chemistry instruments show that the new orbit strategy will neither have a significant impact in the instrument operations nor on the quality of the science data. Therefore we expect that the atmospheric mission will continue nominally until the end of the platform life time, providing to the scientist a unique dataset of the most important geophysical parameters (e.g., trace gases, clouds, and aerosol) spanning a time interval of about 11 years. The aim of this paper is to review the overall ENVISAT atmospheric mission status for the past, present and future. The evolution of the instrument performances since launch will be analyzed with focus on the life-limited items monitoring. The tuning of the instrument in-flight operations decided to cope with instrument degradation or scientific needs will be described. The lessons learned on how to operate and monitor the instruments will be highlighted. Finally the expected evolution of the instrument performances until the ENVISAT end-of-life will be discussed. [1] H. Nett, J. Frerick, T. Paulsen, and G. Levrini, "The

  13. Use of a National Continuing Medical Education Meeting to Provide Simulation-Based Training in Temporary Hemodialysis Catheter Insertion Skills: A Pre-Test Post-Test Study

    Directory of Open Access Journals (Sweden)

    Edward G Clark

    2014-10-01

    Full Text Available Background: Simulation-based-mastery-learning (SBML is an effective method to train nephrology fellows to competently insert temporary, non-tunneled hemodialysis catheters (NTHCs. Previous studies of SBML for NTHC-insertion have been conducted at a local level. Objectives: Determine if SBML for NTHC-insertion can be effective when provided at a national continuing medical education (CME meeting. Describe the correlation of demographic factors, prior experience with NTHC-insertion and procedural self-confidence with simulated performance of the procedure. Design: Pre-test – post-test study. Setting: 2014 Canadian Society of Nephrology annual meeting. Participants: Nephrology fellows, internal medicine residents and medical students. Measurements: Participants were surveyed regarding demographics, prior NTHC-insertion experience, procedural self-confidence and attitudes regarding the training they received. NTHC-insertion skills were assessed using a 28-item checklist. Methods: Participants underwent a pre-test of their NTHC-insertion skills at the internal jugular site using a realistic patient simulator and ultrasound machine. Participants then had a training session that included a didactic presentation and 2 hours of deliberate practice using the simulator. On the following day, trainees completed a post-test of their NTHC-insertion skills. All participants were required to meet or exceed a minimum passing score (MPS previously set at 79%. Trainees who did not reach the MPS were required to perform more deliberate practice until the MPS was achieved. Results: Twenty-two individuals participated in SBML training. None met or exceeded the MPS at baseline with a median checklist score of 20 (IQR, 7.25 to 21. Seventeen of 22 participants (77% completed post-testing and improved their scores to a median of 27 (IQR, 26 to 28; p < 0.001. All met or exceeded the MPS on their first attempt. There were no significant correlations between demographics

  14. Climatic and basin factors affecting the flood frequency curve: PART I – A simple sensitivity analysis based on the continuous simulation approach

    Directory of Open Access Journals (Sweden)

    A. M. Hashemi

    2000-01-01

    Full Text Available Regionalized and at-site flood frequency curves exhibit considerable variability in their shapes, but the factors controlling the variability (other than sampling effects are not well understood. An application of the Monte Carlo simulation-based derived distribution approach is presented in this two-part paper to explore the influence of climate, described by simulated rainfall and evapotranspiration time series, and basin factors on the flood frequency curve (ffc. The sensitivity analysis conducted in the paper should not be interpreted as reflecting possible climate changes, but the results can provide an indication of the changes to which the flood frequency curve might be sensitive. A single site Neyman Scott point process model of rainfall, with convective and stratiform cells (Cowpertwait, 1994; 1995, has been employed to generate synthetic rainfall inputs to a rainfall runoff model. The time series of the potential evapotranspiration (ETp demand has been represented through an AR(n model with seasonal component, while a simplified version of the ARNO rainfall-runoff model (Todini, 1996 has been employed to simulate the continuous discharge time series. All these models have been parameterised in a realistic manner using observed data and results from previous applications, to obtain ‘reference’ parameter sets for a synthetic case study. Subsequently, perturbations to the model parameters have been made one-at-a-time and the sensitivities of the generated annual maximum rainfall and flood frequency curves (unstandardised, and standardised by the mean have been assessed. Overall, the sensitivity analysis described in this paper suggests that the soil moisture regime, and, in particular, the probability distribution of soil moisture content at the storm arrival time, can be considered as a unifying link between the perturbations to the several parameters and their effects on the standardised and unstandardised ffcs, thus revealing the

  15. Use of a national continuing medical education meeting to provide simulation-based training in temporary hemodialysis catheter insertion skills: a pre-test post-test study.

    Science.gov (United States)

    Clark, Edward G; Paparello, James J; Wayne, Diane B; Edwards, Cedric; Hoar, Stephanie; McQuillan, Rory; Schachter, Michael E; Barsuk, Jeffrey H

    2014-01-01

    Simulation-based-mastery-learning (SBML) is an effective method to train nephrology fellows to competently insert temporary, non-tunneled hemodialysis catheters (NTHCs). Previous studies of SBML for NTHC-insertion have been conducted at a local level. Determine if SBML for NTHC-insertion can be effective when provided at a national continuing medical education (CME) meeting. Describe the correlation of demographic factors, prior experience with NTHC-insertion and procedural self-confidence with simulated performance of the procedure. Pre-test - post-test study. 2014 Canadian Society of Nephrology annual meeting. Nephrology fellows, internal medicine residents and medical students. Participants were surveyed regarding demographics, prior NTHC-insertion experience, procedural self-confidence and attitudes regarding the training they received. NTHC-insertion skills were assessed using a 28-item checklist. Participants underwent a pre-test of their NTHC-insertion skills at the internal jugular site using a realistic patient simulator and ultrasound machine. Participants then had a training session that included a didactic presentation and 2 hours of deliberate practice using the simulator. On the following day, trainees completed a post-test of their NTHC-insertion skills. All participants were required to meet or exceed a minimum passing score (MPS) previously set at 79%. Trainees who did not reach the MPS were required to perform more deliberate practice until the MPS was achieved. Twenty-two individuals participated in SBML training. None met or exceeded the MPS at baseline with a median checklist score of 20 (IQR, 7.25 to 21). Seventeen of 22 participants (77%) completed post-testing and improved their scores to a median of 27 (IQR, 26 to 28; p < 0.001). All met or exceeded the MPS on their first attempt. There were no significant correlations between demographics, prior experience or procedural self-confidence with pre-test performance. Small sample-size and

  16. Intelligent Mission Controller Node

    National Research Council Canada - National Science Library

    Perme, David

    2002-01-01

    The goal of the Intelligent Mission Controller Node (IMCN) project was to improve the process of translating mission taskings between real-world Command, Control, Communications, Computers, and Intelligence (C41...

  17. Critical Robotic Lunar Missions

    Science.gov (United States)

    Plescia, J. B.

    2018-04-01

    Perhaps the most critical missions to understanding lunar history are in situ dating and network missions. These would constrain the volcanic and thermal history and interior structure. These data would better constrain lunar evolution models.

  18. Dukovany ASSET mission preparation

    Energy Technology Data Exchange (ETDEWEB)

    Kouklik, I [NPP Dukovany (Czech Republic)

    1997-12-31

    We are in the final stages of the Dukovany ASSET mission 1996 preparation. I would like to present some of our recent experiences. Maybe they would be helpful to other plants, that host ASSET missions in future.

  19. Dukovany ASSET mission preparation

    International Nuclear Information System (INIS)

    Kouklik, I.

    1996-01-01

    We are in the final stages of the Dukovany ASSET mission 1996 preparation. I would like to present some of our recent experiences. Maybe they would be helpful to other plants, that host ASSET missions in future

  20. Mission operations management

    Science.gov (United States)

    Rocco, David A.

    1994-01-01

    Redefining the approach and philosophy that operations management uses to define, develop, and implement space missions will be a central element in achieving high efficiency mission operations for the future. The goal of a cost effective space operations program cannot be realized if the attitudes and methodologies we currently employ to plan, develop, and manage space missions do not change. A management philosophy that is in synch with the environment in terms of budget, technology, and science objectives must be developed. Changing our basic perception of mission operations will require a shift in the way we view the mission. This requires a transition from current practices of viewing the mission as a unique end product, to a 'mission development concept' built on the visualization of the end-to-end mission. To achieve this change we must define realistic mission success criteria and develop pragmatic approaches to achieve our goals. Custom mission development for all but the largest and most unique programs is not practical in the current budget environment, and we simply do not have the resources to implement all of our planned science programs. We need to shift our management focus to allow us the opportunity make use of methodologies and approaches which are based on common building blocks that can be utilized in the space, ground, and mission unique segments of all missions.

  1. Inference of strata separation and gas emission paths in longwall overburden using continuous wavelet transform of well logs and geostatistical simulation

    Science.gov (United States)

    Karacan, C. Özgen; Olea, Ricardo A.

    2014-06-01

    Prediction of potential methane emission pathways from various sources into active mine workings or sealed gobs from longwall overburden is important for controlling methane and for improving mining safety. The aim of this paper is to infer strata separation intervals and thus gas emission pathways from standard well log data. The proposed technique was applied to well logs acquired through the Mary Lee/Blue Creek coal seam of the Upper Pottsville Formation in the Black Warrior Basin, Alabama, using well logs from a series of boreholes aligned along a nearly linear profile. For this purpose, continuous wavelet transform (CWT) of digitized gamma well logs was performed by using Mexican hat and Morlet, as the mother wavelets, to identify potential discontinuities in the signal. Pointwise Hölder exponents (PHE) of gamma logs were also computed using the generalized quadratic variations (GQV) method to identify the location and strength of singularities of well log signals as a complementary analysis. PHEs and wavelet coefficients were analyzed to find the locations of singularities along the logs. Using the well logs in this study, locations of predicted singularities were used as indicators in single normal equation simulation (SNESIM) to generate equi-probable realizations of potential strata separation intervals. Horizontal and vertical variograms of realizations were then analyzed and compared with those of indicator data and training image (TI) data using the Kruskal-Wallis test. A sum of squared differences was employed to select the most probable realization representing the locations of potential strata separations and methane flow paths. Results indicated that singularities located in well log signals reliably correlated with strata transitions or discontinuities within the strata. Geostatistical simulation of these discontinuities provided information about the location and extents of the continuous channels that may form during mining. If there is a gas

  2. Investigations on the effect of forage source, grinding, and urea supplementation on ruminal fermentation and microbial protein flow in a semi-continuous rumen simulation system.

    Science.gov (United States)

    Hildebrand, Bastian; Boguhn, Jeannette; Rodehutscord, Markus

    2011-10-01

    The objective of the present study was to compare the effect of maize silage and grass silage on microbial fermentation and protein flow in a semi-continuous rumen simulation system (Rusitec) when milling screen size (MSS) during grinding was varied. Oven-dried silages were milled through screens of 1, 4 or 9 mm pore size and incubated for 48 h in a Rusitec system. Furthermore, the effect of N supplementation to maize silage (MSS: 4 mm) was investigated and single dose vs. continuous infusion of urea-N were compared. Degradation of organic matter (OM), crude protein (CP), fibre fractions and non-structural carbohydrates (NSC) as well as short-chain fatty acid production differed significantly between forage sources. Urea-N supplementation improved the degradation of NSC, but not that of fibre fractions in maize silage. The way of urea supply had only marginal effects on fermentation characteristics. An increase in MSS, and consequently in mean feed particle size, led to an improvement in the degradation of OM, CP and NSC, but efficiency of microbial net protein synthesis (EMPS; mg microbial N flow/g degraded OM) and the microbial amino acid profile were less affected. EMPS was higher in grass silage than in maize silage and was improved by urea-N supplementation in maize silage. This study indicates that fermentation of NSC as well as EMPS during incubation of maize silage was limited by availability of NH3-N. Furthermore, an increase in MSS above 1 mm seems to improve fermentation of silages in the Rusitec system.

  3. Computer graphics aid mission operations. [NASA missions

    Science.gov (United States)

    Jeletic, James F.

    1990-01-01

    The application of computer graphics techniques in NASA space missions is reviewed. Telemetric monitoring of the Space Shuttle and its components is discussed, noting the use of computer graphics for real-time visualization problems in the retrieval and repair of the Solar Maximum Mission. The use of the world map display for determining a spacecraft's location above the earth and the problem of verifying the relative position and orientation of spacecraft to celestial bodies are examined. The Flight Dynamics/STS Three-dimensional Monitoring System and the Trajectroy Computations and Orbital Products System world map display are described, emphasizing Space Shuttle applications. Also, consideration is given to the development of monitoring systems such as the Shuttle Payloads Mission Monitoring System and the Attitude Heads-Up Display and the use of the NASA-Goddard Two-dimensional Graphics Monitoring System during Shuttle missions and to support the Hubble Space Telescope.

  4. The Asteroid Redirect Mission (ARM)

    Science.gov (United States)

    Abell, Paul; Gates, Michele; Johnson, Lindley; Chodas, Paul; Mazanek, Dan; Reeves, David; Ticker, Ronald

    2016-07-01

    ARM concept would leverage several key ongoing activities in human exploration, space technology, and planetary defense. The ARRM is planned to launch at the end of 2021 and the ARCM is scheduled for late 2026. Mission Objectives: The Asteroid Redirect Mission is designed to address the need for flight experience in cis-lunar space and provide opportunities for testing the systems, technologies, and capabilities that will be required for future human operations in deep space. A principle objective of the ARM is the development of a high-power Solar Electric Propulsion (SEP) vehicle, and the demonstration that it can operate for many years in interplanetary space, which is critical for deep-space exploration missions. A second prime objective of ARM is to conduct a human spaceflight mission involving in-space inter-action with a natural object, in order to provide the systems and operational experience that will be required for eventual human exploration of the Mars system, including the moons Phobos and Deimos. The ARCM provides a focus for the early flights of the Orion program. Astronauts will participate in the scientific in-space investigation of nearly pristine asteroid material, at most only minimally altered by the capture process. The ARCM will provide the opportunity for human explorers to work in space with asteroid material, testing the activities that would be performed and tools that would be needed for later exploration of primitive body surfaces in deep space. The operational experience would be gained close to our home planet, making it a significantly more affordable approach to obtaining this experience. Target Asteroid Candidates: NASA has identified the NEA (341843) 2008 EV5 as the reference target for the ARRM, but is also carrying three other NEAs as potential options [(25143) Itokawa, (162173) Ryugu, and (101955) Bennu]. NASA is continuing to search for additional candidate asteroid targets for ARM. The final target selection for the ARRM will

  5. Removal of furan and phenolic compounds from simulated biomass hydrolysates by batch adsorption and continuous fixed-bed column adsorption methods.

    Science.gov (United States)

    Lee, Sang Cheol; Park, Sunkyu

    2016-09-01

    It has been proposed to remove all potential inhibitors and sulfuric acid in biomass hydrolysates generated from dilute-acid pretreatment of biomass, based on three steps of sugar purification process. This study focused on its first step in which furan and phenolic compounds were selectively removed from the simulated hydrolysates using activated charcoal. Batch adsorption experiments demonstrated that the affinity of activated charcoal for each component was highest in the order of vanillic acid, 4-hydroxybenzoic acid, furfural, acetic acid, sulfuric acid, and xylose. The affinity of activated charcoal for furan and phenolic compounds proved to be significantly higher than that of the other three components. Four separation strategies were conducted with a combination of batch adsorption and continuous fixed-bed column adsorption methods. It was observed that xylose loss was negligible with near complete removal of furan and phenolic compounds, when at least one fixed-bed column adsorption was implemented in the strategy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Mission statement for the Engineering Test Facility

    International Nuclear Information System (INIS)

    1979-10-01

    This Mission Statement defines the ETF activity during its operating life. The results of those operations must provide the data, knowledge, experience, and confidence to continue to the next steps beyond ETF in making fusion power a viable energy option. The results from the ETF mission (operations are assumed to start early in the 1990's) are to bridge the gap between the base of magnetic fusion knowledge at the start of operations and that reqired to design the EPR/DEMO devices

  7. Reservoir simulation with imposed flux continuity conditions on heterogeneous and anisotropic media for general geometries, and the inclusion of hysteresis in forward modeling

    Energy Technology Data Exchange (ETDEWEB)

    Eigestad, Geir Terje

    2003-04-01

    The thesis is divided into two main parts. Part I gives an overview and summary of the theory that lies behind the flow equations and the discretization principles used in the work. Part II is a collection of research papers that have been written by the candidate (in collaboration with others). The main objective of this thesis is the discretization of an elliptic PDE which describes the pressure in a porous medium. The porous medium will in general be described by permeability tensors which are heterogeneous and anisotropic. In addition, the geometry is often complex for practical applications. This requires discretization approaches that are suited for the problems in mind. The discretization approaches used here are based on imposed flux and potential continuity, and will be discussed in detail in Chapter 3 of Part I. These methods are called Multi Point Flux Approximation Methods, and the acronym MPFA will be used for them. Issues related to these methods will be the main issue of this thesis. The rest of this thesis is organised as follows: Part I: Chapter 1 gives a brief overview of the physics and mathematics behind reservoir simulation. The standard mass balance equations are presented, and we try to explain what reservoir simulation is. Some standard discretization s methods are briefly discussed in Chapter 2. The main focus in Part I is on the MPFA discretization approach for various geometries, and is given in Chapter 3. Some details may have been left out in the papers of Part II, and the section serves both as a summary of the discretization method(s), as well as a more detailed description than what is found in the papers. In Chapter 4, extensions to handle time dependent and nonlinear problems are discussed. Some of the numerical examples presented in Part II deal with two phase flow, and are based on the extension given in this chapter. Chapter 5 discusses numerical results that have been obtained for the MPFA methods for elliptic problems, and

  8. Continuous hydrologic simulation and flood-frequency, hydraulic, and flood-hazard analysis of the Blackberry Creek watershed, Kane County, Illinois

    Science.gov (United States)

    Soong, David T.; Straub, Timothy D.; Murphy, Elizabeth A.

    2006-01-01

    Results of hydrologic model, flood-frequency, hydraulic model, and flood-hazard analysis of the Blackberry Creek watershed in Kane County, Illinois, indicate that the 100-year and 500-year flood plains range from approximately 25 acres in the tributary F watershed (a headwater subbasin at the northeastern corner of the watershed) to almost 1,800 acres in Blackberry Creek main stem. Based on 1996 land-cover data, most of the land in the 100-year and 500-year flood plains was cropland, forested and wooded land, and grassland. A relatively small percentage of urban land was in the flood plains. The Blackberry Creek watershed has undergone rapid urbanization in recent decades. The population and urbanized lands in the watershed are projected to double from the 1990 condition by 2020. Recently, flood-induced damage has occurred more frequently in urbanized areas of the watershed. There are concerns about the effect of urbanization on flood peaks and volumes, future flood-mitigation plans, and potential effects on the water quality and stream habitats. This report describes the procedures used in developing the hydrologic models, estimating the flood-peak discharge magnitudes and recurrence intervals for flood-hazard analysis, developing the hydraulic model, and the results of the analysis in graphical and tabular form. The hydrologic model, Hydrological Simulation Program-FORTRAN (HSPF), was used to perform the simulation of continuous water movements through various patterns of land uses in the watershed. Flood-frequency analysis was applied to an annual maximum series to determine flood quantiles in subbasins for flood-hazard analysis. The Hydrologic Engineering Center-River Analysis System (HEC-RAS) hydraulic model was used to determine the 100-year and 500-year flood elevations, and to determine the 100-year floodway. The hydraulic model was calibrated and verified using high water marks and observed inundation maps for the July 17-18, 1996, flood event. Digital

  9. Continuous auditing & continuous monitoring : Continuous value?

    NARCIS (Netherlands)

    van Hillo, Rutger; Weigand, Hans; Espana, S; Ralyte, J; Souveyet, C

    2016-01-01

    Advancements in information technology, new laws and regulations and rapidly changing business conditions have led to a need for more timely and ongoing assurance with effectively working controls. Continuous Auditing (CA) and Continuous Monitoring (CM) technologies have made this possible by

  10. How large are the consequences of covariate imbalance in cluster randomized trials: a simulation study with a continuous outcome and a binary covariate at the cluster level.

    Science.gov (United States)

    Moerbeek, Mirjam; van Schie, Sander

    2016-07-11

    The number of clusters in a cluster randomized trial is often low. It is therefore likely random assignment of clusters to treatment conditions results in covariate imbalance. There are no studies that quantify the consequences of covariate imbalance in cluster randomized trials on parameter and standard error bias and on power to detect treatment effects. The consequences of covariance imbalance in unadjusted and adjusted linear mixed models are investigated by means of a simulation study. The factors in this study are the degree of imbalance, the covariate effect size, the cluster size and the intraclass correlation coefficient. The covariate is binary and measured at the cluster level; the outcome is continuous and measured at the individual level. The results show covariate imbalance results in negligible parameter bias and small standard error bias in adjusted linear mixed models. Ignoring the possibility of covariate imbalance while calculating the sample size at the cluster level may result in a loss in power of at most 25 % in the adjusted linear mixed model. The results are more severe for the unadjusted linear mixed model: parameter biases up to 100 % and standard error biases up to 200 % may be observed. Power levels based on the unadjusted linear mixed model are often too low. The consequences are most severe for large clusters and/or small intraclass correlation coefficients since then the required number of clusters to achieve a desired power level is smallest. The possibility of covariate imbalance should be taken into account while calculating the sample size of a cluster randomized trial. Otherwise more sophisticated methods to randomize clusters to treatments should be used, such as stratification or balance algorithms. All relevant covariates should be carefully identified, be actually measured and included in the statistical model to avoid severe levels of parameter and standard error bias and insufficient power levels.

  11. The STEREO Mission

    CERN Document Server

    2008-01-01

    The STEREO mission uses twin heliospheric orbiters to track solar disturbances from their initiation to 1 AU. This book documents the mission, its objectives, the spacecraft that execute it and the instruments that provide the measurements, both remote sensing and in situ. This mission promises to unlock many of the mysteries of how the Sun produces what has become to be known as space weather.

  12. VEGA Space Mission

    Science.gov (United States)

    Moroz, V.; Murdin, P.

    2000-11-01

    VEGA (mission) is a combined spacecraft mission to VENUS and COMET HALLEY. It was launched in the USSR at the end of 1984. The mission consisted of two identical spacecraft VEGA 1 and VEGA 2. VEGA is an acronym built from the words `Venus' and `Halley' (`Galley' in Russian spelling). The basic design of the spacecraft was the same as has been used many times to deliver Soviet landers and orbiter...

  13. Exploration Supply Chain Simulation

    Science.gov (United States)

    2008-01-01

    The Exploration Supply Chain Simulation project was chartered by the NASA Exploration Systems Mission Directorate to develop a software tool, with proper data, to quantitatively analyze supply chains for future program planning. This tool is a discrete-event simulation that uses the basic supply chain concepts of planning, sourcing, making, delivering, and returning. This supply chain perspective is combined with other discrete or continuous simulation factors. Discrete resource events (such as launch or delivery reviews) are represented as organizational functional units. Continuous resources (such as civil service or contractor program functions) are defined as enabling functional units. Concepts of fixed and variable costs are included in the model to allow the discrete events to interact with cost calculations. The definition file is intrinsic to the model, but a blank start can be initiated at any time. The current definition file is an Orion Ares I crew launch vehicle. Parameters stretch from Kennedy Space Center across and into other program entities (Michaud Assembly Facility, Aliant Techsystems, Stennis Space Center, Johnson Space Center, etc.) though these will only gain detail as the file continues to evolve. The Orion Ares I file definition in the tool continues to evolve, and analysis from this tool is expected in 2008. This is the first application of such business-driven modeling to a NASA/government-- aerospace contractor endeavor.

  14. Continual improvement plan

    Science.gov (United States)

    1994-01-01

    NASA's approach to continual improvement (CI) is a systems-oriented, agency-wide approach that builds on the past accomplishments of NASA Headquarters and its field installations and helps achieve NASA's vision, mission, and values. The NASA of the future will fully use the principles of continual improvement in every aspect of its operations. This NASA CI plan defines a systematic approach and a model for continual improvement throughout NASA, stressing systems integration and optimization. It demonstrates NASA's constancy of purpose for improvement - a consistent vision of NASA as a worldwide leader in top-quality science, technology, and management practices. The CI plan provides the rationale, structures, methods, and steps, and it defines NASA's short term (1-year) objectives for improvement. The CI plan presents the deployment strategies necessary for cascading the goals and objectives throughout the agency. It also provides guidance on implementing continual improvement with participation from top leadership and all levels of employees.

  15. Application of a Detailed Emission Model for Heavy Duty Diesel Engine Simulations Application d'un modèle détaillé d'émissions pour la simulation de gros moteurs diesel

    Directory of Open Access Journals (Sweden)

    Magnusson I.

    2006-12-01

    Full Text Available A detailed chemical model describing the formation of soot and NO is applied to simulate emission formation in a heavy duty diesel engine. Cylinder flow and spray development is simulated using an engine CFD code - Speedstar. Combustion is described using a simple eddy break-up model. Modeling of the emission-chemistry/turbulent-flow interaction is based on a flamelet approach. Contrary to a typical flamelet concept, transport equations are solved for mass fractions of soot and NO. The reason being that these major emission constituencies are assumed to change slowly in comparison to typical time scales for chemical processes or transport processes important for combustion. Chemical reactions leading to production and destruction of soot and NO are, however, assumed to be fast. Soot and NO source terms are therefore evaluated from a flamelet library using a presumed probability density function and integrating over mixture fraction space. Results from simulations are compared to engine measurements inform of exhaust emission data and cylinder pressure. Un modèle avec chimie détaillée décrivant la formation des suies et du NO est appliqué à la simulation de la formation des polluants dans un gros moteur Diesel. L'écoulement et le spray sont modélisés avec le code de calcul Speedstar. La combustion est représentée par le modèle eddy break-up . La modélisation de l'interaction entre l'écoulement turbulent et la chimie des polluants est basée sur une approche de type flamelet . Cependant, à la différence d'autres travaux, des équations de transport pour les fractions massiques de suies et de NO sont résolues. Cela est justifié par la supposition que les temps caractéristiques de formation de ces composés sont longs comparés à ceux associés aux phénomènes de transport et aux réactions chimiques associées à la combustion. Cependant, les vitesses de réaction se rapportant aux suies et au NO sont supposées rapides. Cela

  16. Mission of Mercy.

    Science.gov (United States)

    Humenik, Mark

    2014-01-01

    Some dentists prefer solo charity work, but there is much to be said for collaboration within the profession in reaching out to those who are dentally underserved. Mission of Mercy (MOM) programs are regularly organized across the country for this purpose. This article describes the structure, reach, and personal satisfaction to be gained from such missions.

  17. GPS test range mission planning

    Science.gov (United States)

    Roberts, Iris P.; Hancock, Thomas P.

    The principal features of the Test Range User Mission Planner (TRUMP), a PC-resident tool designed to aid in deploying and utilizing GPS-based test range assets, are reviewed. TRUMP features time history plots of time-space-position information (TSPI); performance based on a dynamic GPS/inertial system simulation; time history plots of TSPI data link connectivity; digital terrain elevation data maps with user-defined cultural features; and two-dimensional coverage plots of ground-based test range assets. Some functions to be added during the next development phase are discussed.

  18. Hipparcos: mission accomplished

    Science.gov (United States)

    1993-08-01

    During the last few months of its life, as the high radiation environment to which the satellite was exposed took its toll on the on-board system, Hipparcos was operated with only two of the three gyroscopes normally required for such a satellite, following an ambitious redesign of the on-board and on-ground systems. Plans were in hand to operate the satellite without gyroscopes at all, and the first such "gyro- less" data had been acquired, when communication failure with the on-board computers on 24 June 1993 put an end to the relentless flow of 24000 bits of data that have been sent down from the satellite each second, since launch. Further attempts to continue operations proved unsuccessful, and after a short series of sub-systems tests, operations were terminated four years and a week after launch. An enormous wealth of scientific data was gathered by Hipparcos. Even though data analysis by the scientific teams involved in the programme is not yet completed, it is clear that the mission has been an overwhelming success. "The ESA advisory bodies took a calculated risk in selecting this complex but fundamental programme" said Dr. Roger Bonnet, ESA's Director of Science, "and we are delighted to have been able to bring it to a highly successful conclusion, and to have contributed unique information that will take a prominent place in the history and development of astrophysics". Extremely accurate positions of more than one hundred thousand stars, precise distance measurements (in most cases for the first time), and accurate determinations of the stars' velocity through space have been derived. The resulting HIPPARCOS Star Catalogue, expected to be completed in 1996, will be of unprecedented accuracy, achieving results some 10-100 times more accurate than those routinely determined from ground-based astronomical observatories. A further star catalogue, the Thyco Star Catalogue of more than a million stars, is being compiled from additional data accumulated by the

  19. Magnetic Satellite Missions and Data

    DEFF Research Database (Denmark)

    Olsen, Nils; Kotsiaros, Stavros

    2011-01-01

    Although the first satellite observations of the Earth’s magnetic field were already taken more than 50 years ago, continuous geomagnetic measurements from space are only available since 1999. The unprecedented time-space coverage of this recent data set opened revolutionary new possibilities...... for exploring the Earth’s magnetic field from space. In this chapter we discuss characteristics of satellites measuring the geomagnetic field and report on past, present and upcoming magnetic satellite missions. We conclude with some basics about space magnetic gradiometry as a possible path for future...... exploration of Earth’s magnetic field with satellites....

  20. Astronaut Neil Armstrong participates in simulation training

    Science.gov (United States)

    1969-01-01

    Astronaut Neil A. Armstrong, Apollo 11 commander, participates in simulation training in preparation for the scheduled lunar landing mission. He is in the Apollo Lunar Module Mission SImulator in the Kennedy Space Center's Flight Crew Training Building.

  1. Informal uncertainty analysis (GLUE) of continuous flow simulation in a hybrid sewer system with infiltration inflow - Consistency of containment ratios in calibration and validation?

    DEFF Research Database (Denmark)

    Breinholt, Anders; Grum, Morten; Madsen, Henrik

    2013-01-01

    to assess parameter and flow simulation uncertainty using a simplified lumped sewer model that accounts for three separate flow contributions: wastewater, fast runoff from paved areas, and slow infiltrating water from permeable areas. Recently GLUE methodology has been critisised for generating prediction...... rain inputs and more accurate flow observations to reduce parameter and model simulation uncertainty. © Author(s) 2013....

  2. ACADEMIC MISSION - FROM AUTOCRACY TO BUREAUCRACY

    Directory of Open Access Journals (Sweden)

    LIVIU NEAMŢU

    2015-12-01

    Full Text Available The mission is generic expression of reason for the existence of an organization. Organizational mission ensure continuity of existence beyond the objectives and targets of activities. It is the expression of an organization's responsibilities towards the environment in which it belongs. As the organization grows and its activities or environmental conditions change, managers adapt their strategies, but stated mission will remain valid for a period of time or unchanged throughout the life of the organization. All managerial elements of the organization are aligned with stated mission, starting from the organization structure, management behavior or specific business processes. The focus of the mission of an higher education institution on a need or several integrated needs, on customers who manifest this need and on how they can be met, that really means defining of its strategic domanin, as a sphere of influence of the organization in their environment. In this sphere of influence, three components integrate on three levels of the mission: to establish needs; identify the customer type to which an organization adress and key competencies that differentiate it from the rest competitors. To that context identifies four specific forms of academic institutions starting from their mission and strategic area: autocratic academic institutions, meritocrate academic institutions, democratic academic institutions, bureaucrats academic institutions.

  3. Continuous Problem of Function Continuity

    Science.gov (United States)

    Jayakody, Gaya; Zazkis, Rina

    2015-01-01

    We examine different definitions presented in textbooks and other mathematical sources for "continuity of a function at a point" and "continuous function" in the context of introductory level Calculus. We then identify problematic issues related to definitions of continuity and discontinuity: inconsistency and absence of…

  4. NASA CYGNSS Tropical Cyclone Mission

    Science.gov (United States)

    Ruf, Chris; Atlas, Robert; Majumdar, Sharan; Ettammal, Suhas; Waliser, Duane

    2017-04-01

    The NASA Cyclone Global Navigation Satellite System (CYGNSS) mission consists of a constellation of eight microsatellites that were launched into low-Earth orbit on 15 December 2016. Each observatory carries a four-channel bistatic scatterometer receiver to measure near surface wind speed over the ocean. The transmitter half of the scatterometer is the constellation of GPS satellites. CYGNSS is designed to address the inadequacy in observations of the inner core of tropical cyclones (TCs) that result from two causes: 1) much of the TC inner core is obscured from conventional remote sensing instruments by intense precipitation in the eye wall and inner rain bands; and 2) the rapidly evolving (genesis and intensification) stages of the TC life cycle are poorly sampled in time by conventional polar-orbiting, wide-swath surface wind imagers. The retrieval of wind speed by CYGNSS in the presence of heavy precipitation is possible due to the long operating wavelength used by GPS (19 cm), at which scattering and attenuation by rain are negligible. Improved temporal sampling by CYGNSS is possible due to the use of eight spacecraft with 4 scatterometer channels on each one. Median and mean revisit times everywhere in the tropics are 3 and 7 hours, respectively. Wind speed referenced to 10m height above the ocean surface is retrieved from CYGNSS measurements of bistatic radar cross section in a manner roughly analogous to that of conventional ocean wind scatterometers. The technique has been demonstrated previously from space by the UK-DMC and UK-TDS missions. Wind speed is retrieved with 25 km spatial resolution and an uncertainty of 2 m/s at low wind speeds and 10% at wind speeds above 20 m/s. Extensive simulation studies conducted prior to launch indicate that there will be a significant positive impact on TC forecast skill for both track and intensity with CYGNSS measurements assimilated into HWRF numerical forecasts. Simulations of CYGNSS spatial and temporal sampling

  5. EUCLID mission design

    Science.gov (United States)

    Wallner, Oswald; Ergenzinger, Klaus; Tuttle, Sean; Vaillon, L.; Johann, Ulrich

    2017-11-01

    EUCLID, a medium-class mission candidate of ESA's Cosmic Vision 2015-2025 Program, currently in Definition Phase (Phase A/B1), shall map the geometry of the Dark Universe by investigating dark matter distributions, the distance-redshift relationship, and the evolution of cosmic structures. EUCLID consists of a 1.2 m telescope and two scientific instruments for ellipticity and redshift measurements in the visible and nearinfrared wavelength regime. We present a design concept of the EUCLID mission which is fully compliant with the mission requirements. Preliminary concepts of the spacecraft and of the payload including the scientific instruments are discussed.

  6. Astronaut training for STS 41-G mission

    Science.gov (United States)

    1984-01-01

    Astronauts training for STS 41-G mission. Payload specialist Paul Scully-Power sits in an office near the space shuttle simulator reviewing a diagram. He is wearging a communications head set. At his elbow is an example of food packets to be used aboard the shuttle.

  7. PLA Missions Beyond Taiwan

    National Research Council Canada - National Science Library

    Miller, Marc

    2008-01-01

    KEY INSIGHTS: *The PLA is being assigned and training for an increasing variety of missions, including nontraditional battlefields such as outer space and cyber space, as well as nontraditional functions...

  8. Autonomous aerobraking for low-cost interplanetary missions

    Science.gov (United States)

    Carrelli, David; O'Shaughnessy, Daniel; Strikwerda, Thomas; Kaidy, James; Prince, Jill; Powell, Richard

    2014-01-01

    Aerobraking has previously been used to reduce the propellant required to deliver an orbiter to its desired final orbit. In principle, aerobraking should be possible around any target planet or moon having sufficient atmosphere to permit atmospheric drag to provide a portion of the mission ΔV, in lieu of supplying all of the required ΔV propulsively. The spacecraft is flown through the upper atmosphere of the target using multiple passes, ensuring that the dynamic pressure and thermal loads remain within the spacecraft's design parameters. NASA has successfully conducted aerobraking operations four times, once at Venus and three times at Mars. While aerobraking reduces the fuel required, it does so at the expense of time (typically 3-6 months), continuous Deep Space Network (DSN) coverage, and a large ground staff. These factors can result in aerobraking being a very expensive operational phase of the mission. However, aerobraking has matured to the point that much of the daily operation could potentially be performed autonomously onboard the spacecraft, thereby reducing the required ground support and attendant aerobraking related costs. To facilitate a lower-risk transition from ground processing to an autonomous capability, the NASA Engineering and Safety Center (NESC) has assembled a team of experts in aerobraking and interplanetary guidance and control to develop a high-fidelity, flight-like simulation. This simulation will be used to demonstrate the overall feasibility while exploring the potential for staff and DSN coverage reductions that autonomous aerobraking might provide. This paper reviews the various elements of autonomous aerobraking and presents an overview of the various models and algorithms that must be transformed from the current ground processing methodology to a flight-like environment. Additionally the high-fidelity flight software test bed, being developed from models used in a recent interplanetary mission, will be summarized.

  9. Human exploration mission studies

    Science.gov (United States)

    Cataldo, Robert L.

    1989-01-01

    The Office of Exploration has established a process whereby all NASA field centers and other NASA Headquarters offices participate in the formulation and analysis of a wide range of mission strategies. These strategies were manifested into specific scenarios or candidate case studies. The case studies provided a systematic approach into analyzing each mission element. First, each case study must address several major themes and rationale including: national pride and international prestige, advancement of scientific knowledge, a catalyst for technology, economic benefits, space enterprise, international cooperation, and education and excellence. Second, the set of candidate case studies are formulated to encompass the technology requirement limits in the life sciences, launch capabilities, space transfer, automation, and robotics in space operations, power, and propulsion. The first set of reference case studies identify three major strategies: human expeditions, science outposts, and evolutionary expansion. During the past year, four case studies were examined to explore these strategies. The expeditionary missions include the Human Expedition to Phobos and Human Expedition to Mars case studies. The Lunar Observatory and Lunar Outpost to Early Mars Evolution case studies examined the later two strategies. This set of case studies established the framework to perform detailed mission analysis and system engineering to define a host of concepts and requirements for various space systems and advanced technologies. The details of each mission are described and, specifically, the results affecting the advanced technologies required to accomplish each mission scenario are presented.

  10. Missions to Venus

    Science.gov (United States)

    Titov, D. V.; Baines, K. H.; Basilevsky, A. T.; Chassefiere, E.; Chin, G.; Crisp, D.; Esposito, L. W.; Lebreton, J.-P.; Lellouch, E.; Moroz, V. I.; Nagy, A. F.; Owen, T. C.; Oyama, K.-I.; Russell, C. T.; Taylor, F. W.; Young, R. E.

    2002-10-01

    Venus has always been a fascinating objective for planetary studies. At the beginning of the space era Venus became one of the first targets for spacecraft missions. Our neighbour in the solar system and, in size, the twin sister of Earth, Venus was expected to be very similar to our planet. However, the first phase of Venus spacecraft exploration in 1962-1992 by the family of Soviet Venera and Vega spacecraft and US Mariner, Pioneer Venus, and Magellan missions discovered an entirely different, exotic world hidden behind a curtain of dense clouds. These studies gave us a basic knowledge of the conditions on the planet, but generated many more questions concerning the atmospheric composition, chemistry, structure, dynamics, surface-atmosphere interactions, atmospheric and geological evolution, and the plasma environment. Despite all of this exploration by more than 20 spacecraft, the "morning star" still remains a mysterious world. But for more than a decade Venus has been a "forgotten" planet with no new missions featuring in the plans of the world space agencies. Now we are witnessing the revival of interest in this planet: the Venus Orbiter mission is approved in Japan, Venus Express - a European orbiter mission - has successfully passed the selection procedure in ESA, and several Venus Discovery proposals are knocking at the doors of NASA. The paper presents an exciting story of Venus spacecraft exploration, summarizes open scientific problems, and builds a bridge to the future missions.

  11. Mission-directed path planning for planetary rover exploration

    Science.gov (United States)

    Tompkins, Paul

    2005-07-01

    Robotic rovers uniquely benefit planetary exploration---they enable regional exploration with the precision of in-situ measurements, a combination impossible from an orbiting spacecraft or fixed lander. Mission planning for planetary rover exploration currently utilizes sophisticated software for activity planning and scheduling, but simplified path planning and execution approaches tailored for localized operations to individual targets. This approach is insufficient for the investigation of multiple, regionally distributed targets in a single command cycle. Path planning tailored for this task must consider the impact of large scale terrain on power, speed and regional access; the effect of route timing on resource availability; the limitations of finite resource capacity and other operational constraints on vehicle range and timing; and the mutual influence between traverses and upstream and downstream stationary activities. Encapsulating this reasoning in an efficient autonomous planner would allow a rover to continue operating rationally despite significant deviations from an initial plan. This research presents mission-directed path planning that enables an autonomous, strategic reasoning capability for robotic explorers. Planning operates in a space of position, time and energy. Unlike previous hierarchical approaches, it treats these dimensions simultaneously to enable globally-optimal solutions. The approach calls on a near incremental search algorithm designed for planning and re-planning under global constraints, in spaces of higher than two dimensions. Solutions under this method specify routes that avoid terrain obstacles, optimize the collection and use of rechargable energy, satisfy local and global mission constraints, and account for the time and energy of interleaved mission activities. Furthermore, the approach efficiently re-plans in response to updates in vehicle state and world models, and is well suited to online operation aboard a robot

  12. NASA's Planetary Science Missions and Participations

    Science.gov (United States)

    Daou, Doris; Green, James L.

    2017-04-01

    NASA's Planetary Science Division (PSD) and space agencies around the world are collaborating on an extensive array of missions exploring our solar system. Planetary science missions are conducted by some of the most sophisticated robots ever built. International collaboration is an essential part of what we do. NASA has always encouraged international participation on our missions both strategic (ie: Mars 2020) and competitive (ie: Discovery and New Frontiers) and other Space Agencies have reciprocated and invited NASA investigators to participate in their missions. NASA PSD has partnerships with virtually every major space agency. For example, NASA has had a long and very fruitful collaboration with ESA. ESA has been involved in the Cassini mission and, currently, NASA funded scientists are involved in the Rosetta mission (3 full instruments, part of another), BepiColombo mission (1 instrument in the Italian Space Agency's instrument suite), and the Jupiter Icy Moon Explorer mission (1 instrument and parts of two others). In concert with ESA's Mars missions NASA has an instrument on the Mars Express mission, the orbit-ground communications package on the Trace Gas Orbiter (launched in March 2016) and part of the DLR/Mars Organic Molecule Analyzer instruments going onboard the ExoMars Rover (to be launched in 2018). NASA's Planetary Science Division has continuously provided its U.S. planetary science community with opportunities to include international participation on NASA missions too. For example, NASA's Discovery and New Frontiers Programs provide U.S. scientists the opportunity to assemble international teams and design exciting, focused planetary science investigations that would deepen the knowledge of our Solar System. The PSD put out an international call for instruments on the Mars 2020 mission. This procurement led to the selection of Spain and Norway scientist leading two instruments and French scientists providing a significant portion of another

  13. Ocean Surface Topography Mission (OSTM) - Jason-2 and Jason-3: Data Documentation Records (NCEI Accession 0118276)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — OSTM/JASON-2 and Jason-3 (scheduled for launch in 2015) are follow-on missions continuing the TOPEX/Poseidon and Jason-1 missions, and are designed to ensure...

  14. Megapixel Longwave Infrared SLS FPAs for High Spatial Resolution Earth Observing Missions, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Earth observing missions like NASA's LANDSAT Data Continuity Mission - Thermal Infrared Sensor (LDCM-TIRS) require greater spatial resolution of the earth than the ~...

  15. Megapixel Longwave Infrared SLS FPAs for High Spatial Resolution Earth Observing Missions, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Earth observing missions like NASA's LANDSAT Data Continuity Mission - Thermal Infrared Sensor (LDCM-TIRS) require greater spatial resolution of the earth than the ~...

  16. Two new DOSXYZnrc sources for 4D Monte Carlo simulations of continuously variable beam configurations, with applications to RapidArc, VMAT, TomoTherapy and CyberKnife

    International Nuclear Information System (INIS)

    Lobo, Julio; Popescu, I Antoniu

    2010-01-01

    We present two new Monte Carlo sources for the DOSXYZnrc code, which can be used to compute dose distributions due to continuously variable beam configurations. These sources support a continuously rotating gantry and collimator, dynamic multileaf collimator (MLC) motion, variable monitor unit (MU) rate, couch rotation and translation in any direction, arbitrary isocentre motion with respect to the patient and variable source-to-axis distance (SAD). These features make them applicable to Monte Carlo simulations for RapidArc(TM), Elekta VMAT, TomoTherapy(TM) and CyberKnife(TM). Unique to these sources is the synchronization between the motion in the DOSXYZnrc geometry and the motion within the linac head, represented by a shared library (either a BEAMnrc accelerator with dynamic component modules, or an external library). The simulations are achieved in single runs, with no intermediate phase space files.

  17. Alertness, performance and off-duty sleep on 8-hour and 12-hour night shifts in a simulated continuous operations control room setting

    Energy Technology Data Exchange (ETDEWEB)

    Baker, T.L. [Institute for Circadian Physiology, Boston, MA (United States)

    1995-04-01

    A growing number of nuclear power plants in the United States have adopted routine 12-hr shift schedules. Because of the potential impact that extended work shifts could have on safe and efficient power plant operation, the U.S. Nuclear Regulatory Commission funded research on 8-hr and 12-hr shifts at the Human Alertness Research Center (HARC) in Boston, Massachusetts. This report describes the research undertaken: a study of simulated 8-hr and 12-hr work shifts that compares alertness, speed, and accuracy at responding to simulator alarms, and relative cognitive performance, self-rated mood and vigor, and sleep-wake patterns of 8-hr versus 12-hr shift workers.

  18. Alertness, performance and off-duty sleep on 8-hour and 12-hour night shifts in a simulated continuous operations control room setting

    International Nuclear Information System (INIS)

    Baker, T.L.

    1995-04-01

    A growing number of nuclear power plants in the United States have adopted routine 12-hr shift schedules. Because of the potential impact that extended work shifts could have on safe and efficient power plant operation, the U.S. Nuclear Regulatory Commission funded research on 8-hr and 12-hr shifts at the Human Alertness Research Center (HARC) in Boston, Massachusetts. This report describes the research undertaken: a study of simulated 8-hr and 12-hr work shifts that compares alertness, speed, and accuracy at responding to simulator alarms, and relative cognitive performance, self-rated mood and vigor, and sleep-wake patterns of 8-hr versus 12-hr shift workers

  19. OSART mission highlights 1991-1992. Operational safety practices in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    This report continues the practice of providing summaries of the OSART missions but the format is the first of its kind. Summaries of missions in the period 1983-1990 have covered missions to operational plants, missions to plants under construction or approaching commissioning and a compilation of good practices identified in OSART missions as separate publications. The format of this report includes all such aspects in one document.

  20. OSART mission highlights 1991-1992. Operational safety practices in nuclear power plants

    International Nuclear Information System (INIS)

    1995-05-01

    This report continues the practice of providing summaries of the OSART missions but the format is the first of its kind. Summaries of missions in the period 1983-1990 have covered missions to operational plants, missions to plants under construction or approaching commissioning and a compilation of good practices identified in OSART missions as separate publications. The format of this report includes all such aspects in one document

  1. Business continuity

    International Nuclear Information System (INIS)

    Breunhoelder, Gert

    2002-01-01

    This presentation deals with the following keypoints: Information Technology (IT) Business Continuity and Recovery essential for any business; lessons learned after Sept. 11 event; Detailed planning, redundancy and testing being the key elements for probability estimation of disasters

  2. Exploration Mission Benefits From Logistics Reduction Technologies

    Science.gov (United States)

    Broyan, James Lee, Jr.; Schlesinger, Thilini; Ewert, Michael K.

    2016-01-01

    Technologies that reduce logistical mass, volume, and the crew time dedicated to logistics management become more important as exploration missions extend further from the Earth. Even modest reductions in logical mass can have a significant impact because it also reduces the packing burden. NASA's Advanced Exploration Systems' Logistics Reduction Project is developing technologies that can directly reduce the mass and volume of crew clothing and metabolic waste collection. Also, cargo bags have been developed that can be reconfigured for crew outfitting and trash processing technologies to increase habitable volume and improve protection against solar storm events are under development. Additionally, Mars class missions are sufficiently distant that even logistics management without resupply can be problematic due to the communication time delay with Earth. Although exploration vehicles are launched with all consumables and logistics in a defined configuration, the configuration continually changes as the mission progresses. Traditionally significant ground and crew time has been required to understand the evolving configuration and locate misplaced items. For key mission events and unplanned contingencies, the crew will not be able to rely on the ground for logistics localization assistance. NASA has been developing a radio frequency identification autonomous logistics management system to reduce crew time for general inventory and enable greater crew self-response to unplanned events when a wide range of items may need to be located in a very short time period. This paper provides a status of the technologies being developed and there mission benefits for exploration missions.

  3. Mathematical modeling and Monte Carlo simulation of thermal inactivation of non-proteolytic Clostridium botulinum spores during continuous microwave-assisted pasteurization

    Science.gov (United States)

    The objective of this study is to develop a mathematical method to simulate the internal temperature history of products processed in a prototype microwave-assisted pasteurization system (MAPS) developed by Washington State University. Two products (10 oz. beef meatball trays and 16 oz. salmon fill...

  4. [The importance of simulation in team training on obstetric emergencies: results of the first phase of the national plan for continuous medical training].

    Science.gov (United States)

    Maio Matos, Francisco; Sousa Gomes, Andrea; Costa, Fernando Jorge; Santos Silva, Isabel; Carvalhas, Joana

    2012-01-01

    Obstetric emergencies are unexpected and random. The traditional model for medical training of these acute events has included lectures combined with sporadic clinical experiences, but this educational method has inherent limitations. Given the variety of manual skills that must be learned and high-risk environment, Obstetrics is uniquely suited for simulation. New technological educational tools provide an opportunity to learn and master technical skills needed in emergent situations as well as the opportunity to rehearse and learn from mistakes without risks to patients. The goals of this study are to assess which are the factors that trainees associate to human fallibility before and after clinical simulation based training; to compare the confidence level to solve emergent obstetric situations between interns and experts with up to 5 years of experience before and after training, and to determine the value that trainees give to simulation as a teaching tool on emergent events. 31 physicians participated at this course sessions. After the course, we verified changes in the factores that trainees associate to human fallibility, an increase in confidence level to solve emergent obstetric and an increase in the value that trainees give to simulation as a teaching tool.

  5. CHEOPS: A transit photometry mission for ESA's small mission programme

    Directory of Open Access Journals (Sweden)

    Queloz D.

    2013-04-01

    Full Text Available Ground based radial velocity (RV searches continue to discover exoplanets below Neptune mass down to Earth mass. Furthermore, ground based transit searches now reach milli-mag photometric precision and can discover Neptune size planets around bright stars. These searches will find exoplanets around bright stars anywhere on the sky, their discoveries representing prime science targets for further study due to the proximity and brightness of their host stars. A mission for transit follow-up measurements of these prime targets is currently lacking. The first ESA S-class mission CHEOPS (CHaracterizing ExoPlanet Satellite will fill this gap. It will perform ultra-high precision photometric monitoring of selected bright target stars almost anywhere on the sky with sufficient precision to detect Earth sized transits. It will be able to detect transits of RV-planets by photometric monitoring if the geometric configuration results in a transit. For Hot Neptunes discovered from the ground, CHEOPS will be able to improve the transit light curve so that the radius can be determined precisely. Because of the host stars' brightness, high precision RV measurements will be possible for all targets. All planets observed in transit by CHEOPS will be validated and their masses will be known. This will provide valuable data for constraining the mass-radius relation of exoplanets, especially in the Neptune-mass regime. During the planned 3.5 year mission, about 500 targets will be observed. There will be 20% of open time available for the community to develop new science programmes.

  6. Continuous tokamaks

    International Nuclear Information System (INIS)

    Peng, Y.K.M.

    1978-04-01

    A tokamak configuration is proposed that permits the rapid replacement of a plasma discharge in a ''burn'' chamber by another one in a time scale much shorter than the elementary thermal time constant of the chamber first wall. With respect to the chamber, the effective duty cycle factor can thus be made arbitrarily close to unity minimizing the cyclic thermal stress in the first wall. At least one plasma discharge always exists in the new tokamak configuration, hence, a continuous tokamak. By incorporating adiabatic toroidal compression, configurations of continuous tokamak compressors are introduced. To operate continuous tokamaks, it is necessary to introduce the concept of mixed poloidal field coils, which spatially groups all the poloidal field coils into three sets, all contributing simultaneously to inducing the plasma current and maintaining the proper plasma shape and position. Preliminary numerical calculations of axisymmetric MHD equilibria in continuous tokamaks indicate the feasibility of their continued plasma operation. Advanced concepts of continuous tokamaks to reduce the topological complexity and to allow the burn plasma aspect ratio to decrease for increased beta are then suggested

  7. Artificial Neural Network-Based Three-dimensional Continuous Response Relationship Construction of 3Cr20Ni10W2 Heat-Resisting Alloy and Its Application in Finite Element Simulation

    Science.gov (United States)

    Li, Le; Wang, Li-yong

    2018-04-01

    The application of accurate constitutive relationship in finite element simulation would significantly contribute to accurate simulation results, which plays a critical role in process design and optimization. In this investigation, the true stress-strain data of 3Cr20Ni10W2 heat-resisting alloy were obtained from a series of isothermal compression tests conducted in a wide temperature range of 1203-1403 K and strain rate range of 0.01-10 s-1 on a Gleeble 1500 testing machine. Then the constitutive relationship was modeled by an optimally constructed and well-trained back-propagation artificial neural network (BP-ANN). The evaluation of the BP-ANN model revealed that it has admirable performance in characterizing and predicting the flow behaviors of 3Cr20Ni10W2 heat-resisting alloy. Meanwhile, a comparison between improved Arrhenius-type constitutive equation and BP-ANN model shows that the latter has higher accuracy. Consequently, the developed BP-ANN model was used to predict abundant stress-strain data beyond the limited experimental conditions and construct the three-dimensional continuous response relationship for temperature, strain rate, strain, and stress. Finally, the three-dimensional continuous response relationship was applied to the numerical simulation of isothermal compression tests. The results show that such constitutive relationship can significantly promote the accuracy improvement of numerical simulation for hot forming processes.

  8. Flight Operations . [Zero Knowledge to Mission Complete

    Science.gov (United States)

    Forest, Greg; Apyan, Alex; Hillin, Andrew

    2016-01-01

    Outline the process that takes new hires with zero knowledge all the way to the point of completing missions in Flight Operations. Audience members should be able to outline the attributes of a flight controller and instructor, outline the training flow for flight controllers and instructors, and identify how the flight controller and instructor attributes are necessary to ensure operational excellence in mission prep and execution. Identify how the simulation environment is used to develop crisis management, communication, teamwork, and leadership skills for SGT employees beyond what can be provided by classroom training.

  9. Synergies Between the Kepler, K2 and TESS Missions with the PLATO Mission (Revised)

    Science.gov (United States)

    Jenkins, Jon M.

    2017-01-01

    Two transit survey missions will have been flown by NASA prior to the launch of ESA's PLATO Mission in 2026, laying the groundwork for exoplanet discovery via the transit method. The Kepler Mission, which launched in 2009, collected data on its 100+ square degree field of view for four years before failure of a reaction wheel ended its primary mission. The results from Kepler include 2300+ confirmed or validated exoplanets, 2200+ planetary candidates, 2100+ eclipsing binaries. Kepler also revolutionized the field of asteroseismology by measuring the pressure mode oscillations of over 15000 solar-like stars spanning the lifecycle of such stars from hydrogen-burning dwarfs to helium-burning red giants. The re-purposed Kepler Mission, dubbed K2, continues to observe fields of view in and near the ecliptic plane for 80 days each, significantly broadening the scope of the astrophysical investigations as well as discovering an additional 156 exoplanets to date. The TESS mission will launch in 2017 to conduct an all-sky survey for small exoplanets orbiting stars 10X closer and 100X brighter than Kepler exoplanet host stars, allowing for far greater follow-up and characterization of their masses as well as their sizes for at least 50 small planets. Future assets such as James Webb Space Telescope, and ground-based assets such as ESOs Very Large Telescope (VLT) array, the Exremely Large Telescope (ELT), and the Thirty Meter Telescope (TMT) will be able to characterize the atmospheric composition and properties of these small planets. TESS will observe each 24 X 96 field of view for 30 days and thereby cover first the southern and then the northern hemisphere over 13 pointings during each year of the primary mission. The pole-most camera will observe the James Webb continuous viewing zone for one year in each hemisphere, permitting much longer period planets to be detected in this region. The PLATO mission will seek to detect habitable Earth-like planets with an instrument

  10. Continuation of the Application of Parallel PIC Simulations to Laser and Electron Transport Through Plasmas Under Conditions Relevant to ICF and SBSS

    International Nuclear Information System (INIS)

    Warren B Mori

    2007-01-01

    In 2006/2007 we continued to study several issues related to underdense laser-plasma interactions. We have been studying the onset and saturation of Raman backscatter for NIF conditions, nonlinear plasma oscillations, and the two-plasmon decay instability

  11. Co-digestion and model simulations of source separated municipal organic waste with cattle manure under batch and continuously stirred tank reactors

    DEFF Research Database (Denmark)

    Tsapekos, Panagiotis; Kougias, Panagiotis; Kuthiala, Sidhant

    2018-01-01

    reactor was comparable with the results obtained from the batch assay (i.e. expected value). Finally, the outputs from an applied mathematical model were in good agreement with the experimental data obtained from the continuous reactor operation, demonstrating that the BioModel can...

  12. Mission to the comets

    International Nuclear Information System (INIS)

    Hughes, D.

    1980-01-01

    The plans of space agencies in the United States and Europe for an exploratory comet mission including a one year rendezvous with comet Temple-2 and a fast fly-by of comet Halley are discussed. The mission provides an opportunity to make comparative measurements on the two different types of comets and also satisfies the three major scientific objectives of cometary missions namely: (1) To determine the chemical nature and the physical structure of cometary nuclei, and the changes that occur with time and orbital position. (2) To study the chemical and physical nature of the atmospheres and ionospheres of comets, the processes that occur in them, and their development with time and orbital position. (3) To determine the nature of the tails of comets and the processes by which they are formed, and to characterise the interaction of comets with solar wind. (UK)

  13. Country programming mission. Namibia

    International Nuclear Information System (INIS)

    1991-01-01

    In response to a request from the Government of Namibia conveyed in a letter dated 29 November 1990 IAEA provided a multi-disciplinary Programming Mission which visited Namibia from 15 - 19 July 1991. The terms of reference of the Mission were: 1. To assess the possibilities and benefits of nuclear energy applications in Namibia's development; 2. To advise on the infrastructure required for nuclear energy projects; 3. To assist in the formulation of project proposals which could be submitted for Agency assistance. This report is based on the findings of the Mission and falls into 3 sections with 8 appendices. The first section is a country profile providing background information, the second section deals with sectorial needs and institutional review of the sectors of agriculture including animal production, life sciences (nuclear medicine and radiotherapy) and radiation protection. The third section includes possible future technical co-operation activities

  14. Retrieving Baseflow from SWOT Mission

    Science.gov (United States)

    Baratelli, F.; Flipo, N.; Biancamaria, S.; Rivière, A.

    2017-12-01

    The quantification of aquifer contribution to river discharge is of primary importance to evaluate the impact of climatic and anthropogenic stresses on the availability of water resources. Several baseflow estimation methods require river discharge measurements, which can be difficult to obtain at high spatio-temporal resolution for large scale basins. The SWOT satellite mission will provide discharge estimations for large rivers (50 - 100 m wide) even in remote basins. The frequency of these estimations depends on the position and ranges from zero to four values in the 21-days satellite cycle. This work aims at answering the following question: can baseflow be estimated from SWOT observations during the mission lifetime? An algorithm based on hydrograph separation by Chapman's filter was developed to automatically estimate the baseflow in a river network at regional or larger scale (> 10000 km2). The algorithm was first applied using the discharge time series simulated at daily time step by a coupled hydrological-hydrogeological model to obtain the reference baseflow estimations. The same algorithm is then forced with discharge time series sampled at SWOT observation frequency. The methodology was applied to the Seine River basin (65000 km2, France). The results show that the average baseflow is estimated with good accuracy for all the reaches which are observed at least once per cycle (relative bias less than 4%). The time evolution of baseflow is also rather well retrieved, with a Nash coefficient which is more than 0.7 for 94% of the network length. This work provides new potential for the SWOT mission in terms of global hydrological analysis.

  15. Coating optimization for the ATHENA+ mission

    DEFF Research Database (Denmark)

    Ferreira, Desiree Della Monica; Christensen, Finn Erland; Jakobsen, Anders Clemen

    2013-01-01

    The ATHENA mission concept, now called ATHENA+, continues to be refined to address important questions in modern astrophysics. Previous studies have established that the requirement for effective area can be achieved using a combination of bi-layer coatings and/or simple graded multilayers. We find...... that further coating developments can improve on the baseline specifications and present here preliminary results on the optimization of coating design based on the new specifications of the ATHENA+ mission. The performances of several material combinations are investigated with the goal of maximizing...

  16. Continuous Dropout.

    Science.gov (United States)

    Shen, Xu; Tian, Xinmei; Liu, Tongliang; Xu, Fang; Tao, Dacheng

    2017-10-03

    Dropout has been proven to be an effective algorithm for training robust deep networks because of its ability to prevent overfitting by avoiding the co-adaptation of feature detectors. Current explanations of dropout include bagging, naive Bayes, regularization, and sex in evolution. According to the activation patterns of neurons in the human brain, when faced with different situations, the firing rates of neurons are random and continuous, not binary as current dropout does. Inspired by this phenomenon, we extend the traditional binary dropout to continuous dropout. On the one hand, continuous dropout is considerably closer to the activation characteristics of neurons in the human brain than traditional binary dropout. On the other hand, we demonstrate that continuous dropout has the property of avoiding the co-adaptation of feature detectors, which suggests that we can extract more independent feature detectors for model averaging in the test stage. We introduce the proposed continuous dropout to a feedforward neural network and comprehensively compare it with binary dropout, adaptive dropout, and DropConnect on Modified National Institute of Standards and Technology, Canadian Institute for Advanced Research-10, Street View House Numbers, NORB, and ImageNet large scale visual recognition competition-12. Thorough experiments demonstrate that our method performs better in preventing the co-adaptation of feature detectors and improves test performance.

  17. MIV Project: Mission scenario

    DEFF Research Database (Denmark)

    Ravazzotti, Mariolina T.; Jørgensen, John Leif; Thuesen, Gøsta

    1997-01-01

    Under the ESA contract #11453/95/NL/JG(SC), aiming at assessing the feasibility of Rendez-vous and docking of unmanned spacecrafts, a msiision scenario was defined. This report describes the secquence of manouvres and task allocations for such missions.......Under the ESA contract #11453/95/NL/JG(SC), aiming at assessing the feasibility of Rendez-vous and docking of unmanned spacecrafts, a msiision scenario was defined. This report describes the secquence of manouvres and task allocations for such missions....

  18. Mars Stratigraphy Mission

    Science.gov (United States)

    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.

  19. The OICETS mission

    Science.gov (United States)

    Jono, Takashi; Arai, Katsuyoshi

    2017-11-01

    The Optical Inter-orbit Communications Engineering Test Satellite (OICETS) was successfully launched on 23th August 2005 and thrown into a circular orbit at the altitude of 610 km. The main mission is to demonstrate the free-space inter satellite laser communications with the cooperation of the Advanced Relay and Technology Mission (ARTEMIS) geostationary satellite developed by the European Space Agency. This paper presents the overview of the OICETS and laser terminal, a history of international cooperation between Japan Aerospace Exploration Agency (JAXA) and ESA and typical results of the inter-orbit laser communication experiment carried out with ARTEMIS.

  20. Continuity theory

    CERN Document Server

    Nel, Louis

    2016-01-01

    This book presents a detailed, self-contained theory of continuous mappings. It is mainly addressed to students who have already studied these mappings in the setting of metric spaces, as well as multidimensional differential calculus. The needed background facts about sets, metric spaces and linear algebra are developed in detail, so as to provide a seamless transition between students' previous studies and new material. In view of its many novel features, this book will be of interest also to mature readers who have studied continuous mappings from the subject's classical texts and wish to become acquainted with a new approach. The theory of continuous mappings serves as infrastructure for more specialized mathematical theories like differential equations, integral equations, operator theory, dynamical systems, global analysis, topological groups, topological rings and many more. In light of the centrality of the topic, a book of this kind fits a variety of applications, especially those that contribute to ...

  1. Plasma brake model for preliminary mission analysis

    Science.gov (United States)

    Orsini, Leonardo; Niccolai, Lorenzo; Mengali, Giovanni; Quarta, Alessandro A.

    2018-03-01

    Plasma brake is an innovative propellantless propulsion system concept that exploits the Coulomb collisions between a charged tether and the ions in the surrounding environment (typically, the ionosphere) to generate an electrostatic force orthogonal to the tether direction. Previous studies on the plasma brake effect have emphasized the existence of a number of different parameters necessary to obtain an accurate description of the propulsive acceleration from a physical viewpoint. The aim of this work is to discuss an analytical model capable of estimating, with the accuracy required by a preliminary mission analysis, the performance of a spacecraft equipped with a plasma brake in a (near-circular) low Earth orbit. The simplified mathematical model is first validated through numerical simulations, and is then used to evaluate the plasma brake performance in some typical mission scenarios, in order to quantify the influence of the system parameters on the mission performance index.

  2. Continuation calculus

    NARCIS (Netherlands)

    Geron, B.; Geuvers, J.H.; de'Liguoro, U.; Saurin, A.

    2013-01-01

    Programs with control are usually modeled using lambda calculus extended with control operators. Instead of modifying lambda calculus, we consider a different model of computation. We introduce continuation calculus, or CC, a deterministic model of computation that is evaluated using only head

  3. Robust UAV Mission Planning

    NARCIS (Netherlands)

    Evers, L.; Dollevoet, T.; Barros, A.I.; Monsuur, H.

    2014-01-01

    Unmanned Aerial Vehicles (UAVs) can provide significant contributions to information gathering in military missions. UAVs can be used to capture both full motion video and still imagery of specific target locations within the area of interest. In order to improve the effectiveness of a

  4. Robust UAV mission planning

    NARCIS (Netherlands)

    Evers, L.; Dollevoet, T.; Barros, A.I.; Monsuur, H.

    2011-01-01

    Unmanned Areal Vehicles (UAVs) can provide significant contributions to information gathering in military missions. UAVs can be used to capture both full motion video and still imagery of specific target locations within the area of interest. In order to improve the effectiveness of a reconnaissance

  5. Robust UAV Mission Planning

    NARCIS (Netherlands)

    Evers, L.; Dollevoet, T; Barros, A.I.; Monsuur, H.

    2011-01-01

    Unmanned Aerial Vehicles (UAVs) can provide significant contributions to information gathering in military missions. UAVs can be used to capture both full motion video and still imagery of specific target locations within the area of interest. In order to improve the effectiveness of a

  6. Robust UAV Mission Planning

    NARCIS (Netherlands)

    L. Evers (Lanah); T.A.B. Dollevoet (Twan); A.I. Barros (Ana); H. Monsuur (Herman)

    2011-01-01

    textabstractUnmanned Areal Vehicles (UAVs) can provide significant contributions to information gathering in military missions. UAVs can be used to capture both full motion video and still imagery of specific target locations within the area of interest. In order to improve the effectiveness of a

  7. The Lobster Mission

    Science.gov (United States)

    Barthelmy, Scott

    2011-01-01

    I will give an overview of the Goddard Lobster mission: the science goals, the two instruments, the overall instruments designs, with particular attention to the wide-field x-ray instrument (WFI) using the lobster-eye-like micro-channel optics.

  8. Towards A Shared Mission

    DEFF Research Database (Denmark)

    Staunstrup, Jørgen; Orth Gaarn-Larsen, Carsten

    A mission shared by stakeholders, management and employees is a prerequisite for an engaging dialog about the many and substantial changes and challenges currently facing universities. Too often this essen-tial dialog reveals mistrust and misunderstandings about the role and outcome of the univer......A mission shared by stakeholders, management and employees is a prerequisite for an engaging dialog about the many and substantial changes and challenges currently facing universities. Too often this essen-tial dialog reveals mistrust and misunderstandings about the role and outcome...... on a shared mission aiming at value creation (in the broadest interpretation). One important aspect of choosing value as the cornerstone of the mission of universities is to stress that the outcome is measured by external stakeholders and by their standards. Most of the paper is devoted to discussing value...... it possible to lead through processes that engage and excite while creating transparency and accountability. The paper will be illustrated with examples from Denmark and the Helios initiative taken by the Danish Academy of Technical Sciences (ATV) under the headline “The value creating university – courage...

  9. Titan Orbiter Aerorover Mission

    Science.gov (United States)

    Sittler Jr., E. C.; Acuna, M.; Burchell, M. J.; Coates, A.; Farrell, W.; Flasar, M.; Goldstein, B. E.; Gorevan, S.; Hartle, R. E.; Johnson, W. T. K.

    2001-01-01

    We propose a combined Titan orbiter and Titan Aerorover mission with an emphasis on both in situ and remote sensing measurements of Titan's surface, atmosphere, ionosphere, and magnetospheric interaction. The biological aspect of the Titan environment will be emphasized by the mission (i.e., search for organic materials which may include simple organics to 'amono' analogues of amino acids and possibly more complex, lightening detection and infrared, ultraviolet, and charged particle interactions with Titan's surface and atmosphere). An international mission is assumed to control costs. NASA will provide the orbiter, launch vehicle, DSN coverage and operations, while international partners will provide the Aerorover and up to 30% of the cost for the scientific instruments through collaborative efforts. To further reduce costs we propose a single PI for orbiter science instruments and a single PI for Aerorover science instruments. This approach will provide single command/data and power interface between spacecraft and orbiter instruments that will have redundant central DPU and power converter for their instruments. A similar approach could be used for the Aerorover. The mission profile will be constructed to minimize conflicts between Aerorover science, orbiter radar science, orbiter radio science, orbiter imaging science, and orbiter fields and particles (FP) science. Additional information is contained in the original extended abstract.

  10. The LISA Pathfinder Mission

    International Nuclear Information System (INIS)

    Armano, M; Audley, H; Born, M; Danzmann, K; Diepholz, I; Auger, G; Binetruy, P; Baird, J; Bortoluzzi, D; Brandt, N; Fitzsimons, E; Bursi, A; Caleno, M; Cavalleri, A; Cesarini, A; Dolesi, R; Ferroni, V; Cruise, M; Dunbar, N; Ferraioli, L

    2015-01-01

    LISA Pathfinder (LPF), the second of the European Space Agency's Small Missions for Advanced Research in Technology (SMART), is a dedicated technology validation mission for future spaceborne gravitational wave detectors, such as the proposed eLISA mission. LISA Pathfinder, and its scientific payload - the LISA Technology Package - will test, in flight, the critical technologies required for low frequency gravitational wave detection: it will put two test masses in a near-perfect gravitational free-fall and control and measure their motion with unprecedented accuracy. This is achieved through technology comprising inertial sensors, high precision laser metrology, drag-free control and an ultra-precise micro-Newton propulsion system. LISA Pathfinder is due to be launched in mid-2015, with first results on the performance of the system being available 6 months thereafter.The paper introduces the LISA Pathfinder mission, followed by an explanation of the physical principles of measurement concept and associated hardware. We then provide a detailed discussion of the LISA Technology Package, including both the inertial sensor and interferometric readout. As we approach the launch of the LISA Pathfinder, the focus of the development is shifting towards the science operations and data analysis - this is described in the final section of the paper (paper)

  11. The Gaia mission

    NARCIS (Netherlands)

    Collaboration, Gaia; Prusti, T.; de Bruijne, J. H. J.; Brown, A. G. A.; Vallenari, A.; Babusiaux, C.; Bailer-Jones, C. A. L.; Bastian, U.; Biermann, M.; Evans, D. W.; Eyer, L.; Jansen, F.; Jordi, C.; Klioner, S. A.; Lammers, U.; Lindegren, L.; Luri, X.; Mignard, F.; Milligan, D. J.; Panem, C.; Poinsignon, V.; Pourbaix, D.; Randich, S.; Sarri, G.; Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.; Valette, V.; van Leeuwen, F.; Walton, N. A.; Aerts, C.; Arenou, F.; Cropper, M.; Drimmel, R.; Høg, E.; Katz, D.; Lattanzi, M. G.; O'Mullane, W.; Grebel, E. K.; Holland, A. D.; Huc, C.; Passot, X.; Bramante, L.; Cacciari, C.; Castañeda, J.; Chaoul, L.; Cheek, N.; De Angeli, F.; Fabricius, C.; Guerra, R.; Hernández, J.; Jean-Antoine-Piccolo, A.; Masana, E.; Messineo, R.; Mowlavi, N.; Nienartowicz, K.; Ordóñez-Blanco, D.; Panuzzo, P.; Portell, J.; Richards, P. J.; Riello, M.; Seabroke, G. M.; Tanga, P.; Thévenin, F.; Torra, J.; Els, S. G.; Gracia-Abril, G.; Comoretto, G.; Garcia-Reinaldos, M.; Lock, T.; Mercier, E.; Altmann, M.; Andrae, R.; Astraatmadja, T. L.; Bellas-Velidis, I.; Benson, K.; Berthier, J.; Blomme, R.; Busso, G.; Carry, B.; Cellino, A.; Clementini, G.; Cowell, S.; Creevey, O.; Cuypers, J.; Davidson, M.; De Ridder, J.; de Torres, A.; Delchambre, L.; Dell'Oro, A.; Ducourant, C.; Frémat, Y.; García-Torres, M.; Gosset, E.; Halbwachs, J. -L; Hambly, N. C.; Harrison, D. L.; Hauser, M.; Hestroffer, D.; Hodgkin, S. T.; Huckle, H. E.; Hutton, A.; Jasniewicz, G.; Jordan, S.; Kontizas, M.; Korn, A. J.; Lanzafame, A. C.; Manteiga, M.; Moitinho, A.; Muinonen, K.; Osinde, J.; Pancino, E.; Pauwels, T.; Petit, J. -M; Recio-Blanco, A.; Robin, A. C.; Sarro, L. M.; Siopis, C.; Smith, M.; Smith, K. W.; Sozzetti, A.; Thuillot, W.; van Reeven, W.; Viala, Y.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aguado, J. J.; Allan, P. M.; Allasia, W.; Altavilla, G.; Álvarez, M. A.; Alves, J.; Anderson, R. I.; Andrei, A. H.; Anglada Varela, E.; Antiche, E.; Antoja, T.; Antón, S.; Arcay, B.; Atzei, A.; Ayache, L.; Bach, N.; Baker, S. G.; Balaguer-Núñez, L.; Barache, C.; Barata, C.; Barbier, A.; Barblan, F.; Baroni, M.; Barrado y Navascués, D.; Barros, M.; Barstow, M. A.; Becciani, U.; Bellazzini, M.; Bellei, G.; Bello García, A.; Belokurov, V.; Bendjoya, P.; Berihuete, A.; Bianchi, L.; Bienaymé, O.; Billebaud, F.; Blagorodnova, N.; Blanco-Cuaresma, S.; Boch, T.; Bombrun, A.; Borrachero, R.; Bouquillon, S.; Bourda, G.; Bouy, H.; Bragaglia, A.; Breddels, M. A.; Brouillet, N.; Brüsemeister, T.; Bucciarelli, B.; Budnik, F.; Burgess, P.; Burgon, R.; Burlacu, A.; Busonero, D.; Buzzi, R.; Caffau, E.; Cambras, J.; Campbell, H.; Cancelliere, R.; Cantat-Gaudin, T.; Carlucci, T.; Carrasco, J. M.; Castellani, M.; Charlot, P.; Charnas, J.; Charvet, P.; Chassat, F.; Chiavassa, A.; Clotet, M.; Cocozza, G.; Collins, R. S.; Collins, P.; Costigan, G.; Crifo, F.; Cross, N. J. G.; Crosta, M.; Crowley, C.; Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David, P.; David, M.; De Cat, P.; de Felice, F.; de Laverny, P.; De Luise, F.; De March, R.; de Martino, D.; de Souza, R.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.; Delgado, H. E.; di Marco, F.; Di Matteo, P.; Diakite, S.; Distefano, E.; Dolding, C.; Dos Anjos, S.; Drazinos, P.; Durán, J.; Dzigan, Y.; Ecale, E.; Edvardsson, B.; Enke, H.; Erdmann, M.; Escolar, D.; Espina, M.; Evans, N. W.; Eynard Bontemps, G.; Fabre, C.; Fabrizio, M.; Faigler, S.; Falcão, A. J.; Farràs Casas, M.; Faye, F.; Federici, L.; Fedorets, G.; Fernández-Hernández, J.; Fernique, P.; Fienga, A.; Figueras, F.; Filippi, F.; Findeisen, K.; Fonti, A.; Fouesneau, M.; Fraile, E.; Fraser, M.; Fuchs, J.; Furnell, R.; Gai, M.; Galleti, S.; Galluccio, L.; Garabato, D.; García-Sedano, F.; Garé, P.; Garofalo, A.; Garralda, N.; Gavras, P.; Gerssen, J.; Geyer, R.; Gilmore, G.; Girona, S.; Giuffrida, G.; Gomes, M.; González-Marcos, A.; González-Núñez, J.; González-Vidal, J. J.; Granvik, M.; Guerrier, A.; Guillout, P.; Guiraud, J.; Gúrpide, A.; Gutiérrez-Sánchez, R.; Guy, L. P.; Haigron, R.; Hatzidimitriou, D.; Haywood, M.; Heiter, U.; Helmi, A.; Hobbs, D.; Hofmann, W.; Holl, B.; Holland, G.; Hunt, J. A. S.; Hypki, A.; Icardi, V.; Irwin, M.; Jevardat de Fombelle, G.; Jofré, P.; Jonker, P. G.; Jorissen, A.; Julbe, F.; Karampelas, A.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, E.; Koposov, S. E.; Kordopatis, G.; Koubsky, P.; Kowalczyk, A.; Krone-Martins, A.; Kudryashova, M.; Kull, I.; Bachchan, R. K.; Lacoste-Seris, F.; Lanza, A. F.; Lavigne, J. -B; Le Poncin-Lafitte, C.; Lebreton, Y.; Lebzelter, T.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Lemaitre, V.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.; Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; Löffler, W.; López, M.; Lopez-Lozano, A.; Lorenz, D.; Loureiro, T.; MacDonald, I.; Magalhães Fernandes, T.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.; Marchant, J. M.; Marconi, M.; Marie, J.; Marinoni, S.; Marrese, P. M.; Marschalkó, G.; Marshall, D. J.; Martín-Fleitas, J. M.; Martino, M.; Mary, N.; Matijevič, G.; Mazeh, T.; McMillan, P. J.; Messina, S.; Mestre, A.; Michalik, D.; Millar, N. R.; Miranda, B. M. H.; Molina, D.; Molinaro, R.; Molinaro, M.; Molnár, L.; Moniez, M.; Montegriffo, P.; Monteiro, D.; Mor, R.; Mora, A.; Morbidelli, R.; Morel, T.; Morgenthaler, S.; Morley, T.; Morris, D.; Mulone, A. F.; Muraveva, T.; Musella, I.; Narbonne, J.; Nelemans, G.; Nicastro, L.; Noval, L.; Ordénovic, C.; Ordieres-Meré, J.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler, F.; Palacin, H.; Palaversa, L.; Parsons, P.; Paulsen, T.; Pecoraro, M.; Pedrosa, R.; Pentikäinen, H.; Pereira, J.; Pichon, B.; Piersimoni, A. M.; Pineau, F. -X; Plachy, E.; Plum, G.; Poujoulet, E.; Prša, A.; Pulone, L.; Ragaini, S.; Rago, S.; Rambaux, N.; Ramos-Lerate, M.; Ranalli, P.; Rauw, G.; Read, A.; Regibo, S.; Renk, F.; Reylé, C.; Ribeiro, R. A.; Rimoldini, L.; Ripepi, V.; Riva, A.; Rixon, G.; Roelens, M.; Romero-Gómez, M.; Rowell, N.; Royer, F.; Rudolph, A.; Ruiz-Dern, L.; Sadowski, G.; Sagristà Sellés, T.; Sahlmann, J.; Salgado, J.; Salguero, E.; Sarasso, M.; Savietto, H.; Schnorhk, A.; Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.; Segransan, D.; Serpell, E.; Shih, I. -C; Smareglia, R.; Smart, R. L.; Smith, C.; Solano, E.; Solitro, F.; Sordo, R.; Soria Nieto, S.; Souchay, J.; Spagna, A.; Spoto, F.; Stampa, U.; Steele, I. A.; Steidelmüller, H.; Stephenson, C. A.; Stoev, H.; Suess, F. F.; Süveges, M.; Surdej, J.; Szabados, L.; Szegedi-Elek, E.; Tapiador, D.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira, R.; Terrett, D.; Tingley, B.; Trager, S. C.; Turon, C.; Ulla, A.; Utrilla, E.; Valentini, G.; van Elteren, A.; Van Hemelryck, E.; van Leeuwen, M.; Varadi, M.; Vecchiato, A.; Veljanoski, J.; Via, T.; Vicente, D.; Vogt, S.; Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.; Weiler, M.; Weingrill, K.; Werner, D.; Wevers, T.; Whitehead, G.; Wyrzykowski, Ł.; Yoldas, A.; Žerjal, M.; Zucker, S.; Zurbach, C.; Zwitter, T.; Alecu, A.; Allen, M.; Allende Prieto, C.; Amorim, A.; Anglada-Escudé, G.; Arsenijevic, V.; Azaz, S.; Balm, P.; Beck, M.; Bernstein, H. -H; Bigot, L.; Bijaoui, A.; Blasco, C.; Bonfigli, M.; Bono, G.; Boudreault, S.; Bressan, A.; Brown, S.; Brunet, P. -M; Bunclark, P.; Buonanno, R.; Butkevich, A. G.; Carret, C.; Carrion, C.; Chemin, L.; Chéreau, F.; Corcione, L.; Darmigny, E.; de Boer, K. S.; de Teodoro, P.; de Zeeuw, P. T.; Delle Luche, C.; Domingues, C. D.; Dubath, P.; Fodor, F.; Frézouls, B.; Fries, A.; Fustes, D.; Fyfe, D.; Gallardo, E.; Gallegos, J.; Gardiol, D.; Gebran, M.; Gomboc, A.; Gómez, A.; Grux, E.; Gueguen, A.; Heyrovsky, A.; Hoar, J.; Iannicola, G.; Isasi Parache, Y.; Janotto, A. -M; Joliet, E.; Jonckheere, A.; Keil, R.; Kim, D. -W; Klagyivik, P.; Klar, J.; Knude, J.; Kochukhov, O.; Kolka, I.; Kos, J.; Kutka, A.; Lainey, V.; LeBouquin, D.; Liu, C.; Loreggia, D.; Makarov, V. V.; Marseille, M. G.; Martayan, C.; Martinez-Rubi, O.; Massart, B.; Meynadier, F.; Mignot, S.; Munari, U.; Nguyen, A. -T; Nordlander, T.; Ocvirk, P.; O'Flaherty, K. S.; Olias Sanz, A.; Ortiz, P.; Osorio, J.; Oszkiewicz, D.; Ouzounis, A.; Palmer, M.; Park, P.; Pasquato, E.; Peltzer, C.; Peralta, J.; Péturaud, F.; Pieniluoma, T.; Pigozzi, E.; Poels, J.; Prat, G.; Prod'homme, T.; Raison, F.; Rebordao, J. M.; Risquez, D.; Rocca-Volmerange, B.; Rosen, S.; Ruiz-Fuertes, M. I.; Russo, F.; Sembay, S.; Serraller Vizcaino, I.; Short, A.; Siebert, A.; Silva, H.; Sinachopoulos, D.; Slezak, E.; Soffel, M.; Sosnowska, D.; Straižys, V.; ter Linden, M.; Terrell, D.; Theil, S.; Tiede, C.; Troisi, L.; Tsalmantza, P.; Tur, D.; Vaccari, M.; Vachier, F.; Valles, P.; Van Hamme, W.; Veltz, L.; Virtanen, J.; Wallut, J. -M; Wichmann, R.; Wilkinson, M. I.; Ziaeepour, H.; Zschocke, S.

    2016-01-01

    Gaia is a cornerstone mission in the science programme of the EuropeanSpace Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept was changed to a direct-imaging approach. Both the spacecraft and the payload were built by

  12. The Mothership Mission Architecture

    Science.gov (United States)

    Ernst, S. M.; DiCorcia, J. D.; Bonin, G.; Gump, D.; Lewis, J. S.; Foulds, C.; Faber, D.

    2015-12-01

    The Mothership is considered to be a dedicated deep space carrier spacecraft. It is currently being developed by Deep Space Industries (DSI) as a mission concept that enables a broad participation in the scientific exploration of small bodies - the Mothership mission architecture. A Mothership shall deliver third-party nano-sats, experiments and instruments to Near Earth Asteroids (NEOs), comets or moons. The Mothership service includes delivery of nano-sats, communication to Earth and visuals of the asteroid surface and surrounding area. The Mothership is designed to carry about 10 nano-sats, based upon a variation of the Cubesat standard, with some flexibility on the specific geometry. The Deep Space Nano-Sat reference design is a 14.5 cm cube, which accommodates the same volume as a traditional 3U CubeSat. To reduce cost, Mothership is designed as a secondary payload aboard launches to GTO. DSI is offering slots for nano-sats to individual customers. This enables organizations with relatively low operating budgets to closely examine an asteroid with highly specialized sensors of their own choosing and carry out experiments in the proximity of or on the surface of an asteroid, while the nano-sats can be built or commissioned by a variety of smaller institutions, companies, or agencies. While the overall Mothership mission will have a financial volume somewhere between a European Space Agencies' (ESA) S- and M-class mission for instance, it can be funded through a number of small and individual funding sources and programs, hence avoiding the processes associated with traditional space exploration missions. DSI has been able to identify a significant interest in the planetary science and nano-satellite communities.

  13. The Double Star mission

    Directory of Open Access Journals (Sweden)

    Liu

    2005-11-01

    Full Text Available The Double Star Programme (DSP was first proposed by China in March, 1997 at the Fragrant Hill Workshop on Space Science, Beijing, organized by the Chinese Academy of Science. It is the first mission in collaboration between China and ESA. The mission is made of two spacecraft to investigate the magnetospheric global processes and their response to the interplanetary disturbances in conjunction with the Cluster mission. The first spacecraft, TC-1 (Tan Ce means "Explorer", was launched on 29 December 2003, and the second one, TC-2, on 25 July 2004 on board two Chinese Long March 2C rockets. TC-1 was injected in an equatorial orbit of 570x79000 km altitude with a 28° inclination and TC-2 in a polar orbit of 560x38000 km altitude. The orbits have been designed to complement the Cluster mission by maximizing the time when both Cluster and Double Star are in the same scientific regions. The two missions allow simultaneous observations of the Earth magnetosphere from six points in space. To facilitate the comparison of data, half of the Double Star payload is made of spare or duplicates of the Cluster instruments; the other half is made of Chinese instruments. The science operations are coordinated by the Chinese DSP Scientific Operations Centre (DSOC in Beijing and the European Payload Operations Service (EPOS at RAL, UK. The spacecraft and ground segment operations are performed by the DSP Operations and Management Centre (DOMC and DSOC in China, using three ground station, in Beijing, Shanghai and Villafranca.

  14. Fracture Behavior of High-Nitrogen Austenitic Stainless Steel Under Continuous Cooling: Physical Simulation of Free-Surface Cracking of Heavy Forgings

    Science.gov (United States)

    Wang, Zhenhua; Xue, Hongpeng; Fu, Wantang

    2018-03-01

    18Mn18Cr0.6N steel was tension tested at 0.001 s-1 to fracture from 1473 K to 1363 K (1200 °C to 1090 °C, fracture temperature) at a cooling rate of 0.4 Ks-1. For comparison, specimens were tension tested at temperatures of 1473 K and 1363 K (1200 °C and 1090 °C). The microstructure near the fracture surface was examined using electron backscatter diffraction analysis. The lowest hot ductility was observed under continuous cooling and was attributed to the suppression of dynamic recrystallization nucleation.

  15. Design and dynamic simulation of a fixed pitch 56 kW wind turbine drive train with a continuously variable transmission

    Science.gov (United States)

    Gallo, C.; Kasuba, R.; Pintz, A.; Spring, J.

    1986-01-01

    The dynamic analysis of a horizontal axis fixed pitch wind turbine generator (WTG) rated at 56 kW is discussed. A mechanical Continuously Variable Transmission (CVT) was incorporated in the drive train to provide variable speed operation capability. One goal of the dynamic analysis was to determine if variable speed operation, by means of a mechanical CVT, is capable of capturing the transient power in the WTG/wind environment. Another goal was to determine the extent of power regulation possible with CVT operation.

  16. TRISTAN - mission complete

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The high energy physics mission of the TRISTAN electron-positron collider at the Japanese KEK Laboratory ended in May. TRISTAN was the first accelerator in Japan at the high energy frontier, and its success owes a great deal to help and encouragement from the world high energy physics community. Its success also marks the first step toward the KEKB project now underway and the subsequent Linear Collider scheme. TRISTAN began operation in November 1986 with a collision energy of 50 GeV, the world's highest electron-positron collision energy at that time. With the addition of superconducting radiofrequency cavities, the energy was continuously increased, reaching a maximum of 64 GeV in 1989. In this exploratory era, the three large detectors - AMY,TOPAZ and VENUS - together with the smaller SHIP group made a rapid survey of particle phenomena in this new energy range. The sixth ('top') quark was first on the list of wanted particles, but the three large groups concluded that there were no new quarks below 32 GeV. The CDF and DO Collaborations at Fermilab's Tevatron recently reported the top quark as being six times as heavy as TRISTAN'S physics reach. Although initial experimental results suggested that the event-shape distributions of multi-hadron events were broadly consistent with the production of the five known quarks, the production rate of hadrons, compared to muons, was seen to rise with energy. The increased energy reach of TRISTAN increased the visibility of the subtle virtual effects of the Z (the electrically neutral carrier of the weak force) produced through the interference of weak and electromagnetic interactions. The rise was found to be slightly larger than expected from five quarks and a Z mass of 92 or 93 GeV, the accepted value at that time. This hinted that the Z mass had to be smaller, as later verified when the SLC and LEP electron-positron colliders at SLAC (Stanford) and CERN respectively came into operation in 1989

  17. Executive Summary - Our mission

    International Nuclear Information System (INIS)

    2007-01-01

    Full text: The Henryk Niewodniczanski Institute of Nuclear Physics (Instytut Fizyki Jadrowej im. Henryka Niewodniczanskiego, IFJ PAN) is currently the largest research institution of the Polish Academy of Sciences (Polska Akademia Nauk). The research activity of the Academy is financed mainly from the State budget via the Ministry of Science and Higher Education. The mission of IFJ PAN is stated in its Charter. According to Paragraphs 5, 6, and 7 of the 2004 Charter, the Institute's duty is to carry out research activities in the following areas: 1. High energy and elementary particle physics (including astrophysics), 2. Nuclear physics and strong interaction, 3. Condensed matter physics, 4. Interdisciplinary research, in particular: in radiation and environmental biology, environmental physics, medical physics, dosimetry, nuclear geophysics, radiochemistry and material engineering. The main tasks of the Institute are: 1. To perform research in the above disciplines, 2. To promote the development of scientists and of specialists qualified to carry out research in these disciplines, 3. To organize a Post-Graduate Study Course, 4. To permit, through agreements with national and foreign research institutions, external scholars to train and gain academic qualifications in the Institute's laboratories, 5. To collaborate with national and local authorities in providing them with expertise in the Institute's research topics, especially concerning radiation protection. These tasks are fulfilled by: 1. Performing individual and coordinated research through individual and collective research grant projects, 2. Initiating and maintaining cooperation with laboratories, organizations and institutions performing similar activities, in Poland and abroad, 3. Conferring scientific degrees and titles, 4. Distributing research results obtained, through peer-reviewed publications and other public media, 5. Organizing scientific meetings, conferences, symposia, training workshops, etc

  18. Continuation calculus

    Directory of Open Access Journals (Sweden)

    Bram Geron

    2013-09-01

    Full Text Available Programs with control are usually modeled using lambda calculus extended with control operators. Instead of modifying lambda calculus, we consider a different model of computation. We introduce continuation calculus, or CC, a deterministic model of computation that is evaluated using only head reduction, and argue that it is suitable for modeling programs with control. It is demonstrated how to define programs, specify them, and prove them correct. This is shown in detail by presenting in CC a list multiplication program that prematurely returns when it encounters a zero. The correctness proof includes termination of the program. In continuation calculus we can model both call-by-name and call-by-value. In addition, call-by-name functions can be applied to call-by-value results, and conversely.

  19. A new synthetic approach to the science of complexity: the MISSION project at NIFS

    International Nuclear Information System (INIS)

    Tetsuya Sato

    1999-01-01

    The present day stage of computer simulation has entered into the third phase. The age of computer simulation in plasma physics dawned in the late 1950's when Oscar Buneman and John Dawson developed the sheet particle model. In 1960's and the early part of 1970's, one devoted oneself to refine the particle model and to develop, more practically, fluid magnetic hydrodynamic models so that the feasibility of the computer simulation methodology could be tested. This age can be called 'dawning of computer simulation'. The so-called supercomputer appeared in the late 1970's and the computer simulation entered the second phase where individual nonlinear phenomena have become possible to be attacked. At present when a supercomputer with the ability of higher than 100 GFlops speed and lager than 10GBytes common memory is available, almost any individual nonlinear phenomenon, whatever it may look complex, can be solved. This age may well be called 'the age of nonlinear solver'. However, as far as the authors are satisfied with using a supercomputer for simply solving an individual nonlinear problem, the computer simulation plays only a passive role in science and would never cause a catastrophic transition to it. Then, the modern science of the 20th century based on reductionism would continue in the coming 21st century, thus the 21st century's science would stay boring and tedious. It must be the computer simulation that can refresh this boring state. At NIFS an extensive effort has been made to establish a new paradigm of science in the 21st century by developing a new synthetic methodology of computer simulation, which the authors call the MISSION Project. The authors present this MISSION Project and propose a working hypothesis of the science of complexity in this talk

  20. Informal uncertainty analysis (GLUE of continuous flow simulation in a hybrid sewer system with infiltration inflow – consistency of containment ratios in calibration and validation?

    Directory of Open Access Journals (Sweden)

    A. Breinholt

    2013-10-01

    Full Text Available Monitoring of flows in sewer systems is increasingly applied to calibrate urban drainage models used for long-term simulation. However, most often models are calibrated without considering the uncertainties. The generalized likelihood uncertainty estimation (GLUE methodology is here applied to assess parameter and flow simulation uncertainty using a simplified lumped sewer model that accounts for three separate flow contributions: wastewater, fast runoff from paved areas, and slow infiltrating water from permeable areas. Recently GLUE methodology has been critisised for generating prediction limits without statistical coherence and consistency and for the subjectivity in the choice of a threshold value to distinguish "behavioural" from "non-behavioural" parameter sets. In this paper we examine how well the GLUE methodology performs when the behavioural parameter sets deduced from a calibration period are applied to generate prediction bounds in validation periods. By retaining an increasing number of parameter sets we aim at obtaining consistency between the GLUE generated 90% prediction limits and the actual containment ratio (CR in calibration. Due to the large uncertainties related to spatio-temporal rain variability during heavy convective rain events, flow measurement errors, possible model deficiencies as well as epistemic uncertainties, it was not possible to obtain an overall CR of more than 80%. However, the GLUE generated prediction limits still proved rather consistent, since the overall CRs obtained in calibration corresponded well with the overall CRs obtained in validation periods for all proportions of retained parameter sets evaluated. When focusing on wet and dry weather periods separately, some inconsistencies were however found between calibration and validation and we address here some of the reasons why we should not expect the coverage of the prediction limits to be identical in calibration and validation periods in real

  1. Continuous Sub-daily Rainfall Simulation for Regional Flood Risk Assessment - Modelling of Spatio-temporal Correlation Structure of Extreme Precipitation in the Austrian Alps

    Science.gov (United States)

    Salinas, J. L.; Nester, T.; Komma, J.; Bloeschl, G.

    2017-12-01

    Generation of realistic synthetic spatial rainfall is of pivotal importance for assessing regional hydroclimatic hazard as the input for long term rainfall-runoff simulations. The correct reproduction of observed rainfall characteristics, such as regional intensity-duration-frequency curves, and spatial and temporal correlations is necessary to adequately model the magnitude and frequency of the flood peaks, by reproducing antecedent soil moisture conditions before extreme rainfall events, and joint probability of flood waves at confluences. In this work, a modification of the model presented by Bardossy and Platte (1992), where precipitation is first modeled on a station basis as a multivariate autoregressive model (mAr) in a Normal space. The spatial and temporal correlation structures are imposed in the Normal space, allowing for a different temporal autocorrelation parameter for each station, and simultaneously ensuring the positive-definiteness of the correlation matrix of the mAr errors. The Normal rainfall is then transformed to a Gamma-distributed space, with parameters varying monthly according to a sinusoidal function, in order to adapt to the observed rainfall seasonality. One of the main differences with the original model is the simulation time-step, reduced from 24h to 6h. Due to a larger availability of daily rainfall data, as opposite to sub-daily (e.g. hourly), the parameters of the Gamma distributions are calibrated to reproduce simultaneously a series of daily rainfall characteristics (mean daily rainfall, standard deviations of daily rainfall, and 24h intensity-duration-frequency [IDF] curves), as well as other aggregated rainfall measures (mean annual rainfall, and monthly rainfall). The calibration of the spatial and temporal correlation parameters is performed in a way that the catchment-averaged IDF curves aggregated at different temporal scales fit the measured ones. The rainfall model is used to generate 10.000 years of synthetic

  2. The SENTINEL-3 Mission: Overview and Status

    Science.gov (United States)

    Benveniste, J.; Mecklenburg, S.

    2015-12-01

    The Copernicus Programme, being Europe's Earth Observation and Monitoring Programme led by the European Union, aims to provide, on a sustainable basis, reliable and timely services related to environmental and security issues. The Sentinel-3 mission forms part of the Copernicus Space Component. Its main objectives, building on the heritage and experience of the European Space Agency's (ESA) ERS and ENVISAT missions, are to measure sea-surface topography, sea- and land-surface temperature and ocean- and land-surface colour in support of ocean forecasting systems, and for environmental and climate monitoring. The series of Sentinel-3 satellites will ensure global, frequent and near-real time ocean, ice and land monitoring, with the provision of observation data in routine, long term (up to 20 years of operations) and continuous fashion, with a consistent quality and a high level of reliability and availability. The Sentinel-3 missions will be jointly operated by ESA and EUMETSAT. ESA will be responsible for the operations, maintenance and evolution of the Sentinel-3 ground segment on land related products and EUMETSAT for the marine products. The Sentinel-3 ground segment systematically acquires, processes and distributes a set of pre-defined core data products. Sentinel-3A is foreseen to be launched at the beginning of November 2015. The paper will give an overview on the mission, its instruments and objectives, the data products provided, the mechanisms to access the mission's data, and if available first results.

  3. 2007 Lunar Regolith Simulant Workshop Overview

    Science.gov (United States)

    McLemore, Carole A.; Fikes, John C.; Howell, Joe T.

    2007-01-01

    The National Aeronautics and Space Administration (NASA) vision has as a cornerstone, the establishment of an Outpost on the Moon. This Lunar Outpost will eventually provide the necessary planning, technology development, and training for a manned mission to Mars in the future. As part of the overall activity, NASA is conducting Earth-based research and advancing technologies to a Technology Readiness Level (TRL) 6 maturity under the Exploration Technology Development Program that will be incorporated into the Constellation Project as well as other projects. All aspects of the Lunar environment, including the Lunar regolith and its properties, are important in understanding the long-term impacts to hardware, scientific instruments, and humans prior to returning to the Moon and living on the Moon. With the goal of reducing risk to humans and hardware and increasing mission success on the Lunar surface, it is vital that terrestrial investigations including both development and verification testing have access to Lunar-like environments. The Marshall Space Flight Center (MSFC) is supporting this endeavor by developing, characterizing, and producing Lunar simulants in addition to analyzing existing simulants for appropriate applications. A Lunar Regolith Simulant Workshop was conducted by MSFC in Huntsville, Alabama, in October 2007. The purpose of the Workshop was to bring together simulant developers, simulant users, and program and project managers from ETDP and Constellation with the goals of understanding users' simulant needs and their applications. A status of current simulant developments such as the JSC-1A (Mare Type Simulant) and the NASA/U.S. Geological Survey Lunar Highlands-Type Pilot Simulant (NU-LHT-1 M) was provided. The method for evaluating simulants, performed via Figures of Merit (FoMs) algorithms, was presented and a demonstration was provided. The four FoM properties currently being assessed are: size, shape, density, and composition. Some of the

  4. Distributed physically-based precipitation-runoff models for continuous simulation of daily runoff in the Columbia River Basin, British Columbia

    International Nuclear Information System (INIS)

    Chin, W.Q.; Salmon, G.M.; Luo, W.

    1997-01-01

    The need to accurately forecast precipitation and water runoff is essential to the operations of hydroelectric power plants. In 1993, BC Hydro established a program to develop, test and improve new and existing atmospheric and hydrologic models that would be suitable for application over the mountainous terrain of British Columbia. The objective was to improve the reliability and accuracy of hydrological models that simulate and forecast precipitation and runoff. Another objective was to develop a modelling system for hydrologic risk assessment in dam safety evaluation. This paper describes progress made in implementing timely measures to resolve problems of reservoir operation in balancing the need for generation of hydroelectric power with conflicting requirements for flood control, fisheries, recreation and other environmental concerns. 23 refs., 11 figs

  5. B plant mission analysis report

    International Nuclear Information System (INIS)

    Lund, D.P.

    1995-01-01

    This report further develops the mission for B Plant originally defined in WHC-EP-0722, ''System Engineering Functions and Requirements for the Hanford Cleanup Mission: First Issue.'' The B Plant mission analysis will be the basis for a functional analysis that breaks down the B Plant mission statement into the necessary activities to accomplish the mission. These activities are the product of the functional analysis and will then be used in subsequent steps of the systems engineering process, such as identifying requirements and allocating those requirements to B Plant functions. The information in this mission analysis and the functional and requirements analysis are a part of the B Plant technical baseline

  6. Straw export in continuous winter wheat and the ability of oil radish catch crops and early sowing of wheat to offset soil C and N losses: A simulation study

    DEFF Research Database (Denmark)

    Peltre, Clément; Nielsen, M; Christensen, Bent Tolstrup

    2016-01-01

    The export of winter wheat straw for bioenergy may reduce soil C stocks and affect N losses. Establishing fast-growing catch crops between successive wheat crops could potentially offset some of the C and N losses. Another option is to sow wheat earlier, increasing biomass production during...... the autumn. The effects of straw export, oil radish catch crop and early sowing of wheat on soil C storage, N leaching losses and N2O emissions were simulated by applying the Daisy model to winter wheat grown continuously for a period of 100 years on a sandy loam soil in a Danish climate. The simulations....... Inclusion of the oil radish catch crop could offset this loss by 2–3 percentage points. Earlier sowing of wheat increased straw production by 18% and reduced loss of soil C by 3–5 percentage points compared to normal sowing time with full straw export. Catch crops and early sowing also reduced N...

  7. Effects of Low- Versus High-Fidelity Simulations on the Cognitive Burden and Performance of Entry-Level Paramedicine Students: A Mixed-Methods Comparison Trial Using Eye-Tracking, Continuous Heart Rate, Difficulty Rating Scales, Video Observation and Interviews.

    Science.gov (United States)

    Mills, Brennen W; Carter, Owen B-J; Rudd, Cobie J; Claxton, Louise A; Ross, Nathan P; Strobel, Natalie A

    2016-02-01

    High-fidelity simulation-based training is often avoided for early-stage students because of the assumption that while practicing newly learned skills, they are ill suited to processing multiple demands, which can lead to "cognitive overload" and poorer learning outcomes. We tested this assumption using a mixed-methods experimental design manipulating psychological immersion. Thirty-nine randomly assigned first-year paramedicine students completed low- or high-environmental fidelity simulations [low-environmental fidelity simulations (LF(en)S) vs. high-environmental fidelity simulation (HF(en)S)] involving a manikin with obstructed airway (SimMan3G). Psychological immersion and cognitive burden were determined via continuous heart rate, eye tracking, self-report questionnaire (National Aeronautics and Space Administration Task Load Index), independent observation, and postsimulation interviews. Performance was assessed by successful location of obstruction and time-to-termination. Eye tracking confirmed that students attended to multiple, concurrent stimuli in HF(en)S and interviews consistently suggested that they experienced greater psychological immersion and cognitive burden than their LF(en)S counterparts. This was confirmed by significantly higher mean heart rate (P cognitive burden but this has considerable educational merit.

  8. Spacelab 3 mission

    Science.gov (United States)

    Dalton, Bonnie P.

    1990-01-01

    Spacelab-3 (SL-3) was the first microgravity mission of extended duration involving crew interaction with animal experiments. This interaction involved sharing the Spacelab environmental system, changing animal food, and changing animal waste trays by the crew. Extensive microbial testing was conducted on the animal specimens and crew and on their ground and flight facilities during all phases of the mission to determine the potential for cross contamination. Macroparticulate sampling was attempted but was unsuccessful due to the unforseen particulate contamination occurring during the flight. Particulate debris of varying size (250 micron to several inches) and composition was recovered post flight from the Spacelab floor, end cones, overhead areas, avionics fan filter, cabin fan filters, tunnel adaptor, and from the crew module. These data are discussed along with solutions, which were implemented, for particulate and microbial containment for future flight facilities.

  9. The THEMIS Mission

    CERN Document Server

    Burch, J. L

    2009-01-01

    The THEMIS mission aims to determine the trigger and large-scale evolution of substorms by employing five identical micro-satellites which line up along the Earth's magnetotail to track the motion of particles, plasma, and waves from one point to another and for the first time, resolve space-time ambiguities in key regions of the magnetosphere on a global scale. The primary goal of THEMIS is to elucidate which magnetotail process is responsible for substorm onset at the region where substorm auroras map: (i) local disruption of the plasma sheet current (current disruption) or (ii) the interaction of the current sheet with the rapid influx of plasma emanating from reconnection. The probes also traverse the radiation belts and the dayside magnetosphere, allowing THEMIS to address additional baseline objectives. This volume describes the mission, the instrumentation, and the data derived from them.

  10. Astronaut training for STS 41-D mission

    Science.gov (United States)

    1984-01-01

    Astronauts David C. Leestma and Kathryn D. Sullivan, two of three 41-D mission specialists, rehearse some of the duties they will be performing on their flight. Dr. Sullivan holds the Krimsky rule against her cheekbones as part of an ongoing Shuttle study on near vision acuity. Astronaut Leestma reviews a flight data file flipbook. They are seated on the floor of the Space Shuttle Simulator, in front of the forward middeck lockers.

  11. Cyber Network Mission Dependencies

    Science.gov (United States)

    2015-09-18

    leak paths”) and determine if firewalls and router access control lists are violating network policy. Visualization tools are provided to help analysts...with which a supply agent may not be familiar. In this environment, errors in requisition are easy to make, and they are costly : an incomplete cyber...establishing an email network and recommend a firewall and additional laptops. YMAL would also match mission details like the deployment location with

  12. The money mission matrix

    OpenAIRE

    Cuperus, Mirthe

    2017-01-01

    Social entrepreneurship is popular in current academics and other media. This thesis adds to this literature by discovering what the drivers are for sustainable social entrepreneurship. Several stakeholders were identified, creating profiles of the key players in social entrepreneurship. These stakeholders uncovered key factors that represent the drivers for sustainable social entrepreneurship. Key factors were then aligned along the two dimensions: Money and Mission. This crea...

  13. Asteroid Kinetic Impactor Missions

    Science.gov (United States)

    Chesley, Steven

    2015-08-01

    Asteroid impact missions can be carried out as a relatively low-cost add-ons to most asteroid rendezvous missions and such impact experiments have tremendous potential, both scientifically and in the arena of planetary defense.The science returns from an impactor demonstration begin with the documentation of the global effects of the impact, such as changes in orbit and rotation state, the creation and dissipation of an ejecta plume and debris disk, and morphological changes across the body due to the transmission of seismic waves, which might induce landslides and toppling of boulders, etc. At a local level, an inspection of the impact crater and ejecta blanket reveals critical material strength information, as well as spectral differences between the surface and subsurface material.From the planetary defense perspective, an impact demonstration will prove humankind’s capacity to alter the orbit of a potentially threatening asteroid. This technological leap comes in two parts. First, terminal guidance systems that can deliver an impactor with small errors relative to the ~100-200 meter size of a likely impactor have yet to be demonstrated in a deep space environment. Second, the response of an asteroid to such an impact is only understood theoretically due to the potentially significant dependence on the momentum carried by escaping ejecta, which would tend to enhance the deflection by tens of percent and perhaps as much as a factor of a few. A lack of validated understanding of momentum enhancement is a significant obstacle in properly sizing a real-world impactor deflection mission.This presentation will describe the drivers for asteroid impact demonstrations and cover the range of such concepts, starting with ESA’s pioneering Don Quijote mission concept and leading to a brief description of concepts under study at the present time, including the OSIRIS-REx/ISIS, BASiX/KIX and AIM/DART (AIDA) concepts.

  14. The Gaia mission

    OpenAIRE

    Prusti, T.; de Bruijne, J. H. J.; Brown, A. G. A.; Vallenari, A.; Babusiaux, C.; Bailer-Jones, C. A. L.; Bastian, U.; Biermann, M.; Evans, D. W.; Eyer, L.; Jansen, F.; Jordi, C.; Klioner, S. A.; Lammers, U.; Lindegren, L.

    2016-01-01

    Gaia is a cornerstone mission in the science programme of the European Space Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept was changed to direct-imaging approach. Both the spacecraft and the payload were built by European industry. The involvement of the scientific community focusses on data processing for which the international Gaia Data Processing and Analysis Consortium (DPAC) was selected in 2007. Gaia wa...

  15. Nanosatellite missions - the future

    Science.gov (United States)

    Koudelka, O.; Kuschnig, R.; Wenger, M.; Romano, P.

    2017-09-01

    In the beginning, nanosatellite projects were focused on educational aspects. In the meantime, the technology matured and now allows to test, demonstrate and validate new systems, operational procedures and services in space at low cost and within much shorter timescales than traditional space endeavors. The number of spacecraft developed and launched has been increasing exponentially in the last years. The constellation of BRITE nanosatellites is demonstrating impressively that demanding scientific requirements can be met with small, low-cost satellites. Industry and space agencies are now embracing small satellite technology. Particularly in the USA, companies have been established to provide commercial services based on CubeSats. The approach is in general different from traditional space projects with their strict product/quality assurance and documentation requirements. The paper gives an overview of nanosatellite missions in different areas of application. Based on lessons learnt from the BRITE mission and recent developments at TU Graz (in particular the implementation of the OPS-SAT nanosatellite for ESA), enhanced technical possibilities for a future astronomy mission after BRITE will be discussed. Powerful on-board computers will allow on-board data pre-processing. A state-of-the-art telemetry system with high data rates would facilitate interference-free operations and increase science data return.

  16. Dawn Mission Update

    Science.gov (United States)

    Sykes, M. V.; Russell, C. T.; Coradini, A.; Christensen, U.; de Sanctis, M. C.; Feldman, W. C.; Jaumann, R.; Keller, U.; Konopliv, A. S.; McCord, T. B.; McFadden, L. A.; McSween, H. Y.; Mottola, S.; Neukum, G.; Pieters, C. M.; Prettyman, T. H.; Raymond, C. A.; Smith, D. E.; Williams, B. G.; Wise, J.; Zuber, M. T.

    2004-11-01

    Dawn, the ninth Discovery mission, will be the first spacecraft to rendezvous with two solar system bodies, the main belt asteroids Vesta and Ceres. This is made possible by utilizing ion propulsion to reach its targets and to maneuver into (and depart) orbits about these bodies. Vesta and Ceres are two terrestrial protoplanets that have survived since the earliest epoch of the solar system and will provide important insights into planet building processes and their evolution under very different circumstances, with and without water. Dawn carries a double framing camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron detector. At Vesta our studies will include the volcanic emplacement of basalts, its differentiation, the possible exposure of its interior near the south pole. At Ceres our studies will include the role of water in its evolution, hydration processes on its surface, and the possible existence of a subsurface ocean. The mission has passed its critical design review and is scheduled to be launched in June 2006 with arrival at Vesta in 2011 and Ceres in 2015. Operation strategies will be presented. Groundbased observations of Vesta, Ceres, and Vesta family members over broad wavelengths, periods and phases will play an important role in detailed mission planning.

  17. The Spartan 1 mission

    Science.gov (United States)

    Cruddace, Raymond G.; Fritz, G. G.; Shrewsberry, D. J.; Brandenstein, D. J.; Creighton, D. C.; Gutschewski, G.; Lucid, S. W.; Nagel, J. M.; Fabian, J. M.; Zimmerman, D.

    1989-01-01

    The first Spartan mission is documented. The Spartan program, an outgrowth of a joint Naval Research Laboratory (NRL)/National Aeronautics and Space Administration (NASA)-Goddard Space Flight Center (GSFC) development effort, was instituted by NASA for launching autonomous, recoverable payloads from the space shuttle. These payloads have a precise pointing system and are intended to support a wide range of space-science observations and experiments. The first Spartan, carrying an NRL X-ray astronomy instrument, was launched by the orbiter Discovery (STS51G) on June 20, 1985 and recovered successfully 45 h later, on June 22. During this period, Spartan 1 conducted a preprogrammed series of observations of two X-ray sources: the Perseus cluster of galaxies and the center of our galaxy. The mission was successful from both on engineering and a scientific viewpoint. Only one problem was encountered, the attitude control system (ACS) shut down earlier than planned because of high attitude control system gas consumption. A preplanned emergency mode then placed Spartan 1 into a stable, safe condition and allowed a safe recovery. The events are described of the mission and presents X-ray maps of the two observed sources, which were produced from the flight data.

  18. Water Quality in the Upper Anacostia River, Maryland: Continuous and Discrete Monitoring with Simulations to Estimate Concentrations and Yields, 2003-05

    Science.gov (United States)

    Miller, Cherie V.; Gutierrez-Magness, Angelica L.; Feit Majedi, Brenda L.; Foster, Gregory D.

    2007-01-01

    From 2003 through 2005, continuous and discrete waterquality data were collected at two stations on the Anacostia River in Maryland: Northeast Branch at Riverdale, Maryland (U.S. Geological Survey Station 01649500) and Northwest Branch near Hyattsville, Maryland (Station 01651000). Both stations are above the heads of tide for the river, and measurements approximately represent contributions of chemicals from the nontidal watersheds in the Anacostia River. This study was a cooperative effort between the U.S. Geological Survey, the Prince George's County Department of Environmental Resources, the Maryland Department of the Environment, the U.S. Environmental Protection Agency, and George Mason University. Samples were collected for suspended sediment, nutrients, and trace metals; data were used to calculate loads of selected chemical parameters, and to evaluate the sources and transport processes of contaminants. Enrichment factors were calculated for some trace metals and used to interpret patterns of occurrence over different flow regimes. Some metals, such as cadmium, lead, and zinc, were slightly enriched as compared to global averages for shales; overall, median values of enrichment factors for all metals were approximately 15 to 35. Stepwise linear regression models were developed on log-transformed concentrations to estimate the concentrations of suspended sediment, total nitrogen, and total phosphorus from continuous data of discharge and turbidity. The use of multiple explanatory variables improved the predictions over traditional rating curves that use only streamflow as the explanatory variable, because other variables such as turbidity measure the hysteretic effects of fine-grained suspended sediment over storm hydrographs. Estimates of the concentrations of suspended sediment from continuous discharge and turbidity showed coefficients of determination for the predictions (multiple R2) of 0.95 and biases of less than 4 percent. Models to estimate the

  19. Nanopolaritonics with a continuum of molecules: simulations of molecular-induced selectivity in plasmonics transport through a continuous Y-shape.

    Science.gov (United States)

    Neuhauser, Daniel

    2011-11-28

    Using the recent NF (near-field) formulation for electrodynamics on the nanoscale, we simulate transport in a Y-shape gold nanostructure in the presence of 2-level molecules. NF is shown to be easily integrated with the Liouville equation, producing a simple and efficient nanopolaritons (plasmons-excitons) solver, with a large time step. Two cases are considered: coating of the gold structure with molecular layers thinner than the structure, and filling space with aligned molecules. In both cases significant effects on the radiation transport are obtained even for low molecular densities. At low densities the effects are primarily an overall reduction of the plasmonics peak, but at higher densities there is a significant selectivity control by the molecules. A redshift is predicted, especially for the space-filling case. The combined nanopolariton shows qualitative hybridization, and the spectral peaks separate with increasing coupling, i.e., with increasing molecular densities. The results open the way to "control of light by light," i.e., controlling plasmonic light transport by inducing a change in the direction of the guiding molecular dipoles through radiation or other means.

  20. [Continuous observation of canal aberrations in S-shaped simulated root canal prepared by hand-used ProTaper files].

    Science.gov (United States)

    Xia, Ling-yun; Leng, Wei-dong; Mao, Min; Yang, Guo-biao; Xiang, Yong-gang; Chen, Xin-mei

    2009-08-01

    To observe the formation of canal aberrations in S-shaped root canals prepared by every file of hand-used ProTaper. Fifteen S-shaped simulated resin root canals were selected. Each root canal was prepared by every file of hand-used ProTaper following the manufacturer instruction. The images of canals prepared by S1, S2, F1, F2 and F3 were taken and stored, which were divided into group S1, S2, F1, F2 and F3. One image of canal unprepared was superposed with the images of the same root canal in these five groups respectively to observe the types and number of canal aberrations, which included unprepared area, danger zone, ledge, elbow, zip and perforation. SPSS12.0 software pakage was used for Fisher's exact probabilities in 2x2 table. Unprepared area decreased following preparation by every file of ProTaper, but it still existed when the canal preparation was finished. The incidence of danger zone, elbow and zip in group F1 was 15/15, 11/15, 4/15, respectively, which was significantly higher than that in group S2(2/15,0,0) (PProTaper.The presence of unprepared area suggests that it is essential to rinse canal abundantly during complicated canal preparation and canal antisepsis after preparation.

  1. Simulation of ablation and plume dynamics under femtosecond double-pulse laser irradiation of aluminum: Comparison of atomistic and continual approaches

    Energy Technology Data Exchange (ETDEWEB)

    Fokin, Vladimir B.; Povarnitsyn, Mikhail E., E-mail: povar@ihed.ras; Levashov, Pavel R.

    2017-02-28

    Highlights: • We model double-pulse laser ablation of aluminum using microscopic and macroscopic approaches. • Both methods show decrease in depth of crater with increasing delay between pulses. • Both methods reveal the plume temperature growth with the increasing delay. • Good agreement between results is a step towards the development of combined model. - Abstract: We elaborated two numerical methods, two-temperature hydrodynamics and hybrid two-temperature molecular dynamics, which take into account basic mechanisms of a metal target response to ultrashort laser irradiation. The model used for the description of the electronic subsystem is identical for both approaches, while the ionic part is defined by an equation of state in hydrodynamics and by an interatomic potential in molecular dynamics. Since the phase diagram of the equation of state and corresponding potential match reasonably well, the dynamics of laser ablation obtained by both methods is quite similar. This correspondence can be considered as a first step towards the development of a self-consistent combined model. Two important processes are highlighted in simulations of double-pulse ablation: (1) the crater depth decrease as a result of recoil flux formation in the nascent plume when the delay between the pulses increases; (2) the plume reheating by the second pulse that gives rise to two- three-fold growth of the electron temperature with the delay varying from 0 to 200 ps.

  2. SPICE for ESA Planetary Missions

    Science.gov (United States)

    Costa, M.

    2018-04-01

    The ESA SPICE Service leads the SPICE operations for ESA missions and is responsible for the generation of the SPICE Kernel Dataset for ESA missions. This contribution will describe the status of these datasets and outline the future developments.

  3. Mission Critical Occupation (MCO) Charts

    Data.gov (United States)

    Office of Personnel Management — Agencies report resource data and targets for government-wide mission critical occupations and agency specific mission critical and/or high risk occupations. These...

  4. Apollo Missions to the Lunar Surface

    Science.gov (United States)

    Graff, Paige V.

    2018-01-01

    Six Apollo missions to the Moon, from 1969-1972, enabled astronauts to collect and bring lunar rocks and materials from the lunar surface to Earth. Apollo lunar samples are curated by NASA Astromaterials at the NASA Johnson Space Center in Houston, TX. Samples continue to be studied and provide clues about our early Solar System. Learn more and view collected samples at: https://curator.jsc.nasa.gov/lunar.

  5. Human Behaviour in Long-Term Missions

    Science.gov (United States)

    1997-01-01

    In this session, Session WP1, the discussion focuses on the following topics: Psychological Support for International Space Station Mission; Psycho-social Training for Man in Space; Study of the Physiological Adaptation of the Crew During A 135-Day Space Simulation; Interpersonal Relationships in Space Simulation, The Long-Term Bed Rest in Head-Down Tilt Position; Psychological Adaptation in Groups of Varying Sizes and Environments; Deviance Among Expeditioners, Defining the Off-Nominal Act in Space and Polar Field Analogs; Getting Effective Sleep in the Space-Station Environment; Human Sleep and Circadian Rhythms are Altered During Spaceflight; and Methodological Approach to Study of Cosmonauts Errors and Its Instrumental Support.

  6. Numerical simulation of the optimal two-mode attacks for two-way continuous-variable quantum cryptography in reverse reconciliation

    International Nuclear Information System (INIS)

    Zhang, Yichen; Zhao, Yijia; Yu, Song; Li, Zhengyu; Guo, Hong

    2017-01-01

    We analyze the security of the two-way continuous-variable quantum key distribution protocol in reverse reconciliation against general two-mode attacks, which represent all accessible attacks at fixed channel parameters. Rather than against one specific attack model, the expression of secret key rates of the two-way protocol are derived against all accessible attack models. It is found that there is an optimal two-mode attack to minimize the performance of the protocol in terms of both secret key rates and maximal transmission distances. We identify the optimal two-mode attack, give the specific attack model of the optimal two-mode attack and show the performance of the two-way protocol against the optimal two-mode attack. Even under the optimal two-mode attack, the performances of two-way protocol are still better than the corresponding one-way protocol, which shows the advantage of making double use of the quantum channel and the potential of long-distance secure communication using a two-way protocol. (paper)

  7. The effects of plant extracts on microbial community structure in a rumen-simulating continuous-culture system as revealed by molecular profiling.

    Science.gov (United States)

    Ferme, D; Banjac, M; Calsamiglia, S; Busquet, M; Kamel, C; Avgustin, G

    2004-01-01

    An in vitro study in dual-flow continuous-culture fermentors was conducted with two different concentrations of monensin, cinnamaldehyde or garlic extract added to 1:1 forage-to-concentrate diet in order to determine their effects on selected rumen bacterial populations. Samples were subjected to total DNA extraction, restriction analysis of PCR amplified parts of 16S rRNA genes (ARDRA) and subsequent analysis of the restriction profiles by lab-on-chip technology with the Agilent's Bioanalyser 2100. Eub338-BacPre primer pair was used to select for the bacteria from the genera Bacteroides, Porphyromonas and Prevotella, especially the latter representing the dominant Gram-negative bacterial population in the rumen. Preliminary results of HaeIII restriction analysis show that the effects of monensin, cinnamaldehyde and garlic extract on the BacPre targeted ruminal bacteria are somewhat different in regard to targeted populations and to the nature of the effect. Garlic extract was found to trigger the most intensive changes in the structure of the BacPre targeted population. Comparison of the in silico restriction analysis of BacPre sequences deposited in different DNA databanks and of the results of performed amplified ribosomal DNA restriction analysis showed differences between the predicted and obtained HaeIII restriction profiles, and suggested the presence of novel, still unknown Prevotella populations in studied samples.

  8. Middleware Evaluation and Benchmarking for Use in Mission Operations Centers

    Science.gov (United States)

    Antonucci, Rob; Waktola, Waka

    2005-01-01

    , and data characteristics, using several middleware products. All results were compared to systems using traditional point-to-point socket communication. By comparing performance results under Merent settings, inferences could be made about each middleware's ability to meet certain requirements of the GPM mission. The second phase simulated a middleware-based mission operations center. Actual mission support tools were either used or simulated to create real world demands on the middleware. Network and computer demands were watched closely to verify that no specific idiosyncrasies of mission operations activities would prove unsupportable by the middleware. In our presentation, we will address some commonly accepted misconceptions concerning middleware in mission support architectures. Specifically, we will focus on the perception that middleware solutions are too slow or impose too much overhead for real-time mission operations, and that middleware solutions are too expensive for small

  9. Simulation Development for Dynamic Situation Awareness and Prediction II

    National Research Council Canada - National Science Library

    Trott, Kevin C

    2006-01-01

    ... within the simulation environment. These simulations provide feedback to prototype C4ISR systems in the form of mission status reports, sensor tracks, and other ISR mission results reports, which can be used to maintain situation...

  10. Climatic and basin factors affecting the flood frequency curve: PART II – A full sensitivity analysis based on the continuous simulation approach combined with a factorial experimental design

    Directory of Open Access Journals (Sweden)

    M. Franchini

    2000-01-01

    Full Text Available The sensitivity analysis described in Hashemi et al. (2000 is based on one-at-a-time perturbations to the model parameters. This type of analysis cannot highlight the presence of parameter interactions which might indeed affect the characteristics of the flood frequency curve (ffc even more than the individual parameters. For this reason, the effects of the parameters of the rainfall, rainfall runoff models and of the potential evapotranspiration demand on the ffc are investigated here through an analysis of the results obtained from a factorial experimental design, where all the parameters are allowed to vary simultaneously. This latter, more complex, analysis confirms the results obtained in Hashemi et al. (2000 thus making the conclusions drawn there of wider validity and not related strictly to the reference set selected. However, it is shown that two-factor interactions are present not only between different pairs of parameters of an individual model, but also between pairs of parameters of different models, such as rainfall and rainfall-runoff models, thus demonstrating the complex interaction between climate and basin characteristics affecting the ffc and in particular its curvature. Furthermore, the wider range of climatic regime behaviour produced within the factorial experimental design shows that the probability distribution of soil moisture content at the storm arrival time is no longer sufficient to explain the link between the perturbations to the parameters and their effects on the ffc, as was suggested in Hashemi et al. (2000. Other factors have to be considered, such as the probability distribution of the soil moisture capacity, and the rainfall regime, expressed through the annual maximum rainfalls over different durations. Keywords: Monte Carlo simulation; factorial experimental design; analysis of variance (ANOVA

  11. A stochastic model for neutron simulation considering the spectrum and nuclear properties with continuous dependence of energy; Um modelo estocastico de simulacao neutronica considerando o espectro e propriedades nucleares com dependencia continua de energia

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, Dayana Queiroz de

    2011-01-15

    This thesis has developed a stochastic model to simulate the neutrons transport in a heterogeneous environment, considering continuous neutron spectra and the nuclear properties with its continuous dependence on energy. This model was implemented using Monte Carlo method for the propagation of neutrons in different environment. Due to restrictions with respect to the number of neutrons that can be simulated in reasonable computational processing time introduced the variable control volume along the (pseudo-) periodic boundary conditions in order to overcome this problem. The choice of class physical Monte Carlo is due to the fact that it can decompose into simpler constituents the problem of solve a transport equation. The components may be treated separately, these are the propagation and interaction while respecting the laws of energy conservation and momentum, and the relationships that determine the probability of their interaction. We are aware of the fact that the problem approached in this thesis is far from being comparable to building a nuclear reactor, but this discussion the main target was to develop the Monte Carlo model, implement the code in a computer language that allows extensions of modular way. This study allowed a detailed analysis of the influence of energy on the neutron population and its impact on the life cycle of neutrons. From the results, even for a simple geometrical arrangement, we can conclude the need to consider the energy dependence, i.e. an spectral effective multiplication factor should be introduced each energy group separately. (author)

  12. MDP: Reliable File Transfer for Space Missions

    Science.gov (United States)

    Rash, James; Criscuolo, Ed; Hogie, Keith; Parise, Ron; Hennessy, Joseph F. (Technical Monitor)

    2002-01-01

    This paper presents work being done at NASA/GSFC by the Operating Missions as Nodes on the Internet (OMNI) project to demonstrate the application of the Multicast Dissemination Protocol (MDP) to space missions to reliably transfer files. This work builds on previous work by the OMNI project to apply Internet communication technologies to space communication. The goal of this effort is to provide an inexpensive, reliable, standard, and interoperable mechanism for transferring files in the space communication environment. Limited bandwidth, noise, delay, intermittent connectivity, link asymmetry, and one-way links are all possible issues for space missions. Although these are link-layer issues, they can have a profound effect on the performance of transport and application level protocols. MDP, a UDP-based reliable file transfer protocol, was designed for multicast environments which have to address these same issues, and it has done so successfully. Developed by the Naval Research Lab in the mid 1990's, MDP is now in daily use by both the US Post Office and the DoD. This paper describes the use of MDP to provide automated end-to-end data flow for space missions. It examines the results of a parametric study of MDP in a simulated space link environment and discusses the results in terms of their implications for space missions. Lessons learned are addressed, which suggest minor enhancements to the MDP user interface to add specific features for space mission requirements, such as dynamic control of data rate, and a checkpoint/resume capability. These are features that are provided for in the protocol, but are not implemented in the sample MDP application that was provided. A brief look is also taken at the status of standardization. A version of MDP known as NORM (Neck Oriented Reliable Multicast) is in the process of becoming an IETF standard.

  13. Austere Human Missions to Mars

    Science.gov (United States)

    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

  14. Mission to Planet Earth

    Science.gov (United States)

    Tilford, Shelby G.; Asrar, Ghassem; Backlund, Peter W.

    1994-01-01

    Mission to Planet Earth (MTPE) is NASA's concept for an international science program to produce the understanding needed to predict changes in the Earth's environment. NASA and its interagency and international partners will place satellites carrying advanced sensors in strategic Earth orbits to gather multidisciplinary data. A sophisticated data system will process and archive an unprecedented amount of information about the Earth and how it works as a system. Increased understanding of the Earth system is a basic human responsibility, a prerequisite to informed management of the planet's resources and to the preservation of the global environment.

  15. The ARTEMIS mission

    CERN Document Server

    Angelopoulos, Vassilis

    2014-01-01

    The ARTEMIS mission was initiated by skillfully moving the two outermost Earth-orbiting THEMIS spacecraft into lunar orbit to conduct unprecedented dual spacecraft observations of the lunar environment. ARTEMIS stands for Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's Interaction with the Sun. Indeed, this volume discusses initial findings related to the Moon’s magnetic and plasma environments and the electrical conductivity of the lunar interior. This work is aimed at researchers and graduate students in both heliophysics and planetary physics. Originally published in Space Science Reviews, Vol. 165/1-4, 2011.

  16. The solar probe mission

    International Nuclear Information System (INIS)

    Feldman, W.C.; Anderson, J.; Bohlin, J.D.; Burlaga, L.F.; Farquhar, R.; Gloeckler, G.; Goldstein, B.E.; Harvey, J.W.; Holzer, T.E.; Jones, W.V.; Kellogg, P.J.; Krimigis, S.M.; Kundu, M.R.; Lazarus, A.J.; Mellott, M.M.; Parker, E.N.; Rosner, R.; Rottman, G.J.; Slavin, J.A.; Suess, S.T.; Tsurutani, B.T.; Woo, R.T.; Zwickl, R.D.

    1990-01-01

    The Solar Probe will deliver a 133.5 kg science payload into a 4 R s perihelion solar polar orbit (with the first perihelion passage in 2004) to explore in situ one of the last frontiers in the solar system---the solar corona. This mission is both affordable and technologically feasible. Using a payload of 12 (predominantly particles and fields) scientific experiments, it will be possible to answer many long-standing, fundamental problems concerning the structure and dynamics of the outer solar atmosphere, including the acceleration, storage, and transport of energetic particles near the Sun and in the inner ( s ) heliosphere

  17. Mission to Planet Earth

    International Nuclear Information System (INIS)

    Wilson, G.S.; Backlund, P.W.

    1992-01-01

    Mission to Planet Earth (MTPE) is NASA's concept for an international science program to produce the understanding needed to predict changes in the earth's environment. NASA and its interagency and international partners will place satellites carrying advanced sensors in strategic earth orbits to gather multidisciplinary data. A sophisticated data system will process and archive an unprecedented amount of information about the earth and how it works as a system. Increased understanding of the earth system is a basic human responsibility, a prerequisite to informed management of the planet's resources and to the preservation of the global environment. 8 refs

  18. STS-61 mission director's post-mission report

    Science.gov (United States)

    Newman, Ronald L.

    1995-01-01

    To ensure the success of the complex Hubble Space Telescope servicing mission, STS-61, NASA established a number of independent review groups to assess management, design, planning, and preparation for the mission. One of the resulting recommendations for mission success was that an overall Mission Director be appointed to coordinate management activities of the Space Shuttle and Hubble programs and to consolidate results of the team reviews and expedite responses to recommendations. This report presents pre-mission events important to the experience base of mission management, with related Mission Director's recommendations following the event(s) to which they apply. All Mission Director's recommendations are presented collectively in an appendix. Other appendixes contain recommendations from the various review groups, including Payload Officers, the JSC Extravehicular Activity (EVA) Section, JSC EVA Management Office, JSC Crew and Thermal Systems Division, and the STS-61 crew itself. This report also lists mission events in chronological order and includes as an appendix a post-mission summary by the lead Payload Deployment and Retrieval System Officer. Recommendations range from those pertaining to specific component use or operating techniques to those for improved management, review, planning, and safety procedures.

  19. Mission control of multiple unmanned aerial vehicles: a workload analysis.

    Science.gov (United States)

    Dixon, Stephen R; Wickens, Christopher D; Chang, Dervon

    2005-01-01

    With unmanned aerial vehicles (UAVs), 36 licensed pilots flew both single-UAV and dual-UAV simulated military missions. Pilots were required to navigate each UAV through a series of mission legs in one of the following three conditions: a baseline condition, an auditory autoalert condition, and an autopilot condition. Pilots were responsible for (a) mission completion, (b) target search, and (c) systems monitoring. Results revealed that both the autoalert and the autopilot automation improved overall performance by reducing task interference and alleviating workload. The autoalert system benefited performance both in the automated task and mission completion task, whereas the autopilot system benefited performance in the automated task, the mission completion task, and the target search task. Practical implications for the study include the suggestion that reliable automation can help alleviate task interference and reduce workload, thereby allowing pilots to better handle concurrent tasks during single- and multiple-UAV flight control.

  20. Solar maximum mission

    International Nuclear Information System (INIS)

    Ryan, J.

    1981-01-01

    By understanding the sun, astrophysicists hope to expand this knowledge to understanding other stars. To study the sun, NASA launched a satellite on February 14, 1980. The project is named the Solar Maximum Mission (SMM). The satellite conducted detailed observations of the sun in collaboration with other satellites and ground-based optical and radio observations until its failure 10 months into the mission. The main objective of the SMM was to investigate one aspect of solar activity: solar flares. A brief description of the flare mechanism is given. The SMM satellite was valuable in providing information on where and how a solar flare occurs. A sequence of photographs of a solar flare taken from SMM satellite shows how a solar flare develops in a particular layer of the solar atmosphere. Two flares especially suitable for detailed observations by a joint effort occurred on April 30 and May 21 of 1980. These flares and observations of the flares are discussed. Also discussed are significant discoveries made by individual experiments

  1. The Euclid mission design

    Science.gov (United States)

    Racca, Giuseppe D.; Laureijs, René; Stagnaro, Luca; Salvignol, Jean-Christophe; Lorenzo Alvarez, José; Saavedra Criado, Gonzalo; Gaspar Venancio, Luis; Short, Alex; Strada, Paolo; Bönke, Tobias; Colombo, Cyril; Calvi, Adriano; Maiorano, Elena; Piersanti, Osvaldo; Prezelus, Sylvain; Rosato, Pierluigi; Pinel, Jacques; Rozemeijer, Hans; Lesna, Valentina; Musi, Paolo; Sias, Marco; Anselmi, Alberto; Cazaubiel, Vincent; Vaillon, Ludovic; Mellier, Yannick; Amiaux, Jérôme; Berthé, Michel; Sauvage, Marc; Azzollini, Ruyman; Cropper, Mark; Pottinger, Sabrina; Jahnke, Knud; Ealet, Anne; Maciaszek, Thierry; Pasian, Fabio; Zacchei, Andrea; Scaramella, Roberto; Hoar, John; Kohley, Ralf; Vavrek, Roland; Rudolph, Andreas; Schmidt, Micha

    2016-07-01

    Euclid is a space-based optical/near-infrared survey mission of the European Space Agency (ESA) to investigate the nature of dark energy, dark matter and gravity by observing the geometry of the Universe and on the formation of structures over cosmological timescales. Euclid will use two probes of the signature of dark matter and energy: Weak gravitational Lensing, which requires the measurement of the shape and photometric redshifts of distant galaxies, and Galaxy Clustering, based on the measurement of the 3-dimensional distribution of galaxies through their spectroscopic redshifts. The mission is scheduled for launch in 2020 and is designed for 6 years of nominal survey operations. The Euclid Spacecraft is composed of a Service Module and a Payload Module. The Service Module comprises all the conventional spacecraft subsystems, the instruments warm electronics units, the sun shield and the solar arrays. In particular the Service Module provides the extremely challenging pointing accuracy required by the scientific objectives. The Payload Module consists of a 1.2 m three-mirror Korsch type telescope and of two instruments, the visible imager and the near-infrared spectro-photometer, both covering a large common field-of-view enabling to survey more than 35% of the entire sky. All sensor data are downlinked using K-band transmission and processed by a dedicated ground segment for science data processing. The Euclid data and catalogues will be made available to the public at the ESA Science Data Centre.

  2. EU Universities’ Mission Statements

    Directory of Open Access Journals (Sweden)

    Liudmila Arcimaviciene

    2015-04-01

    Full Text Available In the last 10 years, a highly productive space of metaphor analysis has been established in the discourse studies of media, politics, business, and education. In the theoretical framework of Conceptual Metaphor Theory and Critical Discourse Analysis, the restored metaphorical patterns are especially valued for their implied ideological value as realized both conceptually and linguistically. By using the analytical framework of Critical Metaphor Analysis and procedurally employing Pragglejaz Group’s Metaphor Identification Procedure, this study aims at analyzing the implied value of the evoked metaphors in the mission statements of the first 20 European Universities, according to the Webometrics ranking. In this article, it is proposed that Universities’ mission statements are based on the positive evaluation of the COMMERCE metaphor, which does not fully correlate with the ideological framework of sustainability education but is rather oriented toward consumerism in both education and society. Despite this overall trend, there are some traceable features of the conceptualization reflecting the sustainability approach to higher education, as related to freedom of speech, tolerance, and environmental concerns. Nonetheless, these are suppressed by the metaphoric usages evoking traditional dogmas of the conservative ideology grounded in the concepts of the transactional approach to relationship, competitiveness for superiority, the importance of self-interest and strength, and quantifiable quality.

  3. IAEA Remediation Mission Issues Final Report

    International Nuclear Information System (INIS)

    2011-01-01

    Full text: A team of international experts today completed their assessment of the strategy and plans being considered by the Japanese authorities to remediate the areas off-site TEPCO's Fukushima Daiichi Nuclear Power Plant (NPP). Their Final Report, delivered to the Japanese authorities, is available here. ''A lot of good work, done at all levels, is on-going in Japan in the area of environmental remediation,'' said Juan Carlos Lentijo, Team Leader and General Director for Radiation Protection at Spain's nuclear regulatory authority. In the report, Japan is encouraged to continue its remediation efforts, taking into account the advice provided by the Mission. ''In the early phases of the Fukushima Daiichi accident, a very cautious approach was adopted by the Japanese authorities in terms of dealing with the handling of residue materials. It is considered right to do so,'' Lentijo said. ''However, at this point in time, we see that there is room to take a more balanced approach, focussing on the real priority areas, classifying residue materials and adopting appropriate remediation measures on the basis of the results of safety assessments for each specific situation.'' The IAEA stands ready to support Japan as it continues its efforts to remediate the environment in the area off-site the Fukushima Daiichi NPP. The IAEA sent the mission to Japan from 7 to 15 October 2011 following a request from the country's government. The mission, comprising 12 international and IAEA experts from several countries, visited numerous locations in the Fukushima Prefecture and conducted meetings in Tokyo and Fukushima with Japanese officials from several ministries and institutions. A Preliminary Summary Report was issued on 14 October. Background The accident at the Fukushima Daiichi NPP has led to elevated levels of radiation over large areas. The Government of Japan has been formulating a strategy and plans to implement countermeasures to remediate these areas. The IAEA

  4. STS-78 Mission Insignia

    Science.gov (United States)

    1996-01-01

    The STS-78 patch links past with present to tell the story of its mission and science through a design imbued with the strength and vitality of the 2-dimensional art of North America's northwest coast Indians. Central to the design is the space Shuttle whose bold lines and curves evoke the Indian image for the eagle, a native American symbol of power and prestige as well as the national symbol of the United States. The wings of the Shuttle suggest the wings of the eagle whose feathers, indicative of peace and friendship in Indian tradition, are captured by the U forms, a characteristic feature of Northwest coast Indian art. The nose of the Shuttle is the strong downward curve of the eagle's beak, and the Shuttle's forward windows, the eagle's eyes, represented through the tapered S forms again typical of this Indian art form. The basic black and red atoms orbiting the mission number recall the original NASA emblem while beneath, utilizing Indian ovoid forms, the major mission scientific experiment package LMS (Life and Materials Sciences) housed in the Shuttle's cargo bay is depicted in a manner reminiscent of totem-pole art. This image of a bird poised for flight, so common to Indian art, is counterpointed by an equally familiar Tsimshian Indian symbol, a pulsating sun with long hyperbolic rays, the symbol of life. Within each of these rays are now encased crystals, the products of this mission's 3 major, high-temperature materials processing furnaces. And as the sky in Indian lore is a lovely open country, home of the Sun Chief and accessible to travelers through a hole in the western horizon, so too, space is a vast and beckoning landscape for explorers launched beyond the horizon. Beneath the Tsimshian sun, the colors of the earth limb are appropriately enclosed by a red border representing life to the Northwest coast Indians. The Indian colors of red, navy blue, white, and black pervade the STS-78 path. To the right of the Shuttle-eagle, the constellation

  5. Ocean Surface Topography Mission (OSTM) /Jason-2: Level-2 Geophysical Data Records (GDR) (NODC Accession 0043269)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — OSTM/JASON-2 is a follow-on mission continuing the TOPEX/Poseidon and Jason-1, and is designed to ensure continuity of high quality measurements for ocean science...

  6. Ocean Surface Topography Mission (OSTM) /Jason-2 Data Collection, 2008-present (NODC Accession 0118277)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — OSTM/JASON-2 is a follow-on mission continuing the TOPEX/Poseidon and Jason-1, and is designed to ensure continuity of high quality measurements for ocean science...

  7. The MARS2013 Mars analog mission.

    Science.gov (United States)

    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.

  8. Predictive Modeling for NASA Entry, Descent and Landing Missions

    Science.gov (United States)

    Wright, Michael

    2016-01-01

    Entry, Descent and Landing (EDL) Modeling and Simulation (MS) is an enabling capability for complex NASA entry missions such as MSL and Orion. MS is used in every mission phase to define mission concepts, select appropriate architectures, design EDL systems, quantify margin and risk, ensure correct system operation, and analyze data returned from the entry. In an environment where it is impossible to fully test EDL concepts on the ground prior to use, accurate MS capability is required to extrapolate ground test results to expected flight performance.

  9. A Dynamic Continuation-Passing Style for Dynamic Delimited Continuations

    DEFF Research Database (Denmark)

    Biernacki, Dariusz; Danvy, Olivier; Millikin, Kevin Scott

    2005-01-01

    We present a new abstract machine that accounts for dynamic delimited continuations. We prove the correctness of this new abstract machine with respect to a pre-existing, definitional abstract machine. Unlike this definitional abstract machine, the new abstract machine is in defunctionalized form......, which makes it possible to state the corresponding higher-order evaluator. This evaluator is in continuation+state passing style and threads a trail of delimited continuations and a meta-continuation. Since this style accounts for dynamic delimited continuations, we refer to it as `dynamic continuation......-passing style.' We show that the new machine operates more efficiently than the definitional one and that the notion of computation induced by the corresponding evaluator takes the form of a monad. We also present new examples and a new simulation of dynamic delimited continuations in terms of static ones....

  10. Future NASA mission applications of space nuclear power

    International Nuclear Information System (INIS)

    Bennett, G.L.; Mankins, J.; McConnell, D.G.; Reck, G.M.

    1990-01-01

    Recent studies sponsored by NASA show a continuing need for space nuclear power. A recently completed study considered missions such as a Jovian grand tour, a Uranus or Neptune orbiter and probe, and a Pluto flyby that can only be done with nuclear power. There are studies for missions beyond the outer boundaries of the solar system at distances of 100 to 1000 astronomical units. The NASA 90-day study on the space exploration initiative identified a need for nuclear reactors to power lunar surface bases and radioisotope power sources for use in lunar or Martian rovers, as well as considering options for advanced, nuclear propulsion systems for human missions to Mars

  11. The Waste Negotiator's mission

    International Nuclear Information System (INIS)

    Bataille, Christian

    1993-01-01

    The mission of the Waste Negotiator is to seek out sites for deep underground laboratories to study their potential for disposal of high level radioactive waste. Although appointed by the government, he acts independently. In 1990, faced by severe public criticism at the way that the waste disposal was being handled, and under increasing pressure to find an acceptable solution, the government stopped the work being carried out by ANDRA (Agence nationale pour la gestion des dechets radioactifs) and initiated a full review of the issues involved. At the same time, parliament also started its own extensive investigation to find a way forward. These efforts finally led to the provision of a detailed framework for the management of long lived radioactive waste, including the construction of two laboratories to investigate possible repository sites. The Waste Negotiator was appointed to carry out a full consultative process in the communities which are considering accepting an underground laboratory. (Author)

  12. Identification of Mission Sensitivities with Mission Modeling from the One System Organization at Hanford - 13292

    Energy Technology Data Exchange (ETDEWEB)

    Belsher, Jeremy D.; Pierson, Kayla L. [Washington River Protection Solutions, LLC, Richland, WA 99352 (United States); Gimpel, Rod F. [One System - Waste Treatment Project, Richland, WA 99352 (United States)

    2013-07-01

    The Hanford site in southeast Washington contains approximately 207 million liters of radioactive and hazardous waste stored in 177 underground tanks. The U.S. Department of Energy's Office of River Protection is currently managing the Hanford waste treatment mission, which includes the storage, retrieval, treatment and disposal of the tank waste. Two recent studies, employing the modeling tools managed by the One System organization, have highlighted waste cleanup mission sensitivities. The Hanford Tank Waste Operations Simulator Sensitivity Study evaluated the impact that varying 21 different parameters had on the Hanford Tank Waste Operations Simulator model. It concluded that inaccuracies in the predicted phase partitioning of a few key components can result in significant changes in the waste treatment duration and in the amount of immobilized high-level waste that is produced. In addition, reducing the efficiency with which tank waste is retrieved and staged can increase mission duration. The 2012 WTP Tank Utilization Assessment concluded that flowsheet models need to include the latest low-activity waste glass algorithms or the waste treatment mission duration and the amount of low activity waste that is produced could be significantly underestimated. (authors)

  13. STS-40 Mission Insignia

    Science.gov (United States)

    1990-01-01

    The STS-40 patch makes a contemporary statement focusing on human beings living and working in space. Against a background of the universe, seven silver stars, interspersed about the orbital path of Columbia, represent the seven crew members. The orbiter's flight path forms a double-helix, designed to represent the DNA molecule common to all living creatures. In the words of a crew spokesman, ...(the helix) affirms the ceaseless expansion of human life and American involvement in space while simultaneously emphasizing the medical and biological studies to which this flight is dedicated. Above Columbia, the phrase Spacelab Life Sciences 1 defines both the Shuttle mission and its payload. Leonardo Da Vinci's Vitruvian man, silhouetted against the blue darkness of the heavens, is in the upper center portion of the patch. With one foot on Earth and arms extended to touch Shuttle's orbit, the crew feels, he serves as a powerful embodiment of the extension of human inquiry from the boundaries of Earth to the limitless laboratory of space. Sturdily poised amid the stars, he serves to link scentists on Earth to the scientists in space asserting the harmony of efforts which produce meaningful scientific spaceflight missions. A brilliant red and yellow Earth limb (center) links Earth to space as it radiates from a native American symbol for the sun. At the frontier of space, the traditional symbol for the sun vividly links America's past to America's future, the crew states. Beneath the orbiting Shuttle, darkness of night rests peacefully over the United States. Drawn by artist Sean Collins, the STS 40 Space Shuttle patch was designed by the crewmembers for the flight.

  14. NASA CYGNSS Mission Overview

    Science.gov (United States)

    Ruf, C. S.; Balasubramaniam, R.; Gleason, S.; McKague, D. S.; O'Brien, A.

    2017-12-01

    The CYGNSS constellation of eight satellites was successfully launched on 15 December 2016 into a low inclination (tropical) Earth orbit. Each satellite carries a four-channel bi-static radar receiver that measures GPS signals scattered by the ocean, from which ocean surface roughness, near surface wind speed, and air-sea latent heat flux are estimated. The measurements are unique in several respects, most notably in their ability to penetrate through all levels of precipitation, made possible by the low frequency at which GPS operates, and in the frequent sampling of tropical cyclone intensification and of the diurnal cycle of winds, made possible by the large number of satellites. Engineering commissioning of the constellation was successfully completed in March 2017 and the mission is currently in the early phase of science operations. Level 2 science data products have been developed for near surface (10 m referenced) ocean wind speed, ocean surface roughness (mean square slope) and latent heat flux. Level 3 gridded versions of the L2 products have also been developed. A set of Level 4 products have also been developed specifically for direct tropical cyclone overpasses. These include the storm intensity (peak sustained winds) and size (radius of maximum winds), its extent (34, 50 and 64 knot wind radii), and its integrated kinetic energy. Assimilation of CYGNSS L2 wind speed data into the HWRF hurricane weather prediction model has also been developed. An overview and the current status of the mission will be presented, together with highlights of early on-orbit performance and scientific results.

  15. The Messenger Mission to Mercury

    CERN Document Server

    Domingue, D. L

    2007-01-01

    NASA’s MESSENGER mission, launched on 3 August, 2004 is the seventh mission in the Discovery series. MESSENGER encounters the planet Mercury four times, culminating with an insertion into orbit on 18 March 2011. It carries a comprehensive package of geophysical, geological, geochemical, and space environment experiments to complete the complex investigations of this solar-system end member, which begun with Mariner 10. The articles in this book, written by the experts in each area of the MESSENGER mission, describe the mission, spacecraft, scientific objectives, and payload. The book is of interest to all potential users of the data returned by the MESSENGER mission, to those studying the nature of the planet Mercury, and by all those interested in the design and implementation of planetary exploration missions.

  16. Open source IPSEC software in manned and unmanned space missions

    Science.gov (United States)

    Edwards, Jacob

    Network security is a major topic of research because cyber attackers pose a threat to national security. Securing ground-space communications for NASA missions is important because attackers could endanger mission success and human lives. This thesis describes how an open source IPsec software package was used to create a secure and reliable channel for ground-space communications. A cost efficient, reproducible hardware testbed was also created to simulate ground-space communications. The testbed enables simulation of low-bandwidth and high latency communications links to experiment how the open source IPsec software reacts to these network constraints. Test cases were built that allowed for validation of the testbed and the open source IPsec software. The test cases also simulate using an IPsec connection from mission control ground routers to points of interest in outer space. Tested open source IPsec software did not meet all the requirements. Software changes were suggested to meet requirements.

  17. Optimal design and experimental validation of a simulated moving bed chromatography for continuous recovery of formic acid in a model mixture of three organic acids from Actinobacillus bacteria fermentation.

    Science.gov (United States)

    Park, Chanhun; Nam, Hee-Geun; Lee, Ki Bong; Mun, Sungyong

    2014-10-24

    The economically-efficient separation of formic acid from acetic acid and succinic acid has been a key issue in the production of formic acid with the Actinobacillus bacteria fermentation. To address this issue, an optimal three-zone simulated moving bed (SMB) chromatography for continuous separation of formic acid from acetic acid and succinic acid was developed in this study. As a first step for this task, the adsorption isotherm and mass-transfer parameters of each organic acid on the qualified adsorbent (Amberchrom-CG300C) were determined through a series of multiple frontal experiments. The determined parameters were then used in optimizing the SMB process for the considered separation. During such optimization, the additional investigation for selecting a proper SMB port configuration, which could be more advantageous for attaining better process performances, was carried out between two possible configurations. It was found that if the properly selected port configuration was adopted in the SMB of interest, the throughout and the formic-acid product concentration could be increased by 82% and 181% respectively. Finally, the optimized SMB process based on the properly selected port configuration was tested experimentally using a self-assembled SMB unit with three zones. The SMB experimental results and the relevant computer simulation verified that the developed process in this study was successful in continuous recovery of formic acid from a ternary organic-acid mixture of interest with high throughput, high purity, high yield, and high product concentration. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Lunar Exploration Missions Since 2006

    Science.gov (United States)

    Lawrence, S. J. (Editor); Gaddis, L. R.; Joy, K. H.; Petro, N. E.

    2017-01-01

    The announcement of the Vision for Space Exploration in 2004 sparked a resurgence in lunar missions worldwide. Since the publication of the first "New Views of the Moon" volume, as of 2017 there have been 11 science-focused missions to the Moon. Each of these missions explored different aspects of the Moon's geology, environment, and resource potential. The results from this flotilla of missions have revolutionized lunar science, and resulted in a profoundly new emerging understanding of the Moon. The New Views of the Moon II initiative itself, which is designed to engage the large and vibrant lunar science community to integrate the results of these missions into new consensus viewpoints, is a direct outcome of this impressive array of missions. The "Lunar Exploration Missions Since 2006" chapter will "set the stage" for the rest of the volume, introducing the planetary community at large to the diverse array of missions that have explored the Moon in the last decade. Content: This chapter will encompass the following missions: Kaguya; ARTEMIS (Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon’s Interaction with the Sun); Chang’e-1; Chandrayaan-1; Moon Impact Probe; Lunar Reconnaissance Orbiter (LRO); Lunar Crater Observation Sensing Satellite (LCROSS); Chang’e-2; Gravity Recovery and Interior Laboratory (GRAIL); Lunar Atmosphere and Dust Environment Explorer (LADEE); Chang’e-3.

  19. IRIS Mission Operations Director's Colloquium

    Science.gov (United States)

    Carvalho, Robert; Mazmanian, Edward A.

    2014-01-01

    Pursuing the Mysteries of the Sun: The Interface Region Imaging Spectrograph (IRIS) Mission. Flight controllers from the IRIS mission will present their individual experiences on IRIS from development through the first year of flight. This will begin with a discussion of the unique nature of IRISs mission and science, and how it fits into NASA's fleet of solar observatories. Next will be a discussion of the critical roles Ames contributed in the mission including spacecraft and flight software development, ground system development, and training for launch. This will be followed by experiences from launch, early operations, ongoing operations, and unusual operations experiences. The presentation will close with IRIS science imagery and questions.

  20. Solar and Drag Sail Propulsion: From Theory to Mission Implementation

    Science.gov (United States)

    Johnson, Les; Alhorn, Dean; Boudreaux, Mark; Casas, Joe; Stetson, Doug; Young, Roy

    2014-01-01

    Solar and drag sail technology is entering the mainstream for space propulsion applications within NASA and around the world. Solar sails derive propulsion by reflecting sunlight from a large, mirror- like sail made of a lightweight, reflective material. The continuous sunlight pressure provides efficient primary propulsion, without the expenditure of propellant or any other consumable, allowing for very high V maneuvers and long-duration deep space exploration. Drag sails increase the aerodynamic drag on Low Earth Orbit (LEO) spacecraft, providing a lightweight and relatively inexpensive approach for end-of-life deorbit and reentry. Since NASA began investing in the technology in the late 1990's, significant progress has been made toward their demonstration and implementation in space. NASA's Marshall Space Flight Center (MSFC) managed the development and testing of two different 20-m solar sail systems and rigorously tested them under simulated space conditions in the Glenn Research Center's Space Power Facility at Plum Brook Station, Ohio. One of these systems, developed by L'Garde, Inc., is planned for flight in 2015. Called Sunjammer, the 38m sailcraft will unfurl in deep space and demonstrate solar sail propulsion and navigation as it flies to Earth-Sun L1. In the Flight Center (MSFC) managed the development and testing of two different 20-m solar sail systems and rigorously tested them under simulated space conditions in the Glenn Research Center's Space Power Facility at Plum Brook Station, Ohio. One of these systems, developed by L'Garde, Inc., is planned for flight in 2015. Called Sunjammer, the 38m sailcraft will unfurl in deep space and demonstrate solar sail propulsion and navigation as it flies to Earth-Sun L1. In the interim, NASA MSFC funded the NanoSail-D, a subscale drag sail system designed for small spacecraft applications. The NanoSail-D flew aboard the Fast Affordable Science and Technology SATellite (FASTSAT) in 2010, also developed by MSFC