WorldWideScience

Sample records for advanced waveform simulation

  1. Simulated lidar waveforms for understanding factors affecting waveform shape

    Science.gov (United States)

    Kim, Angela M.; Olsen, Richard C.

    2011-06-01

    Full-waveform LIDAR is a technology which enables the analysis of the 3-D structure and arrangement of objects. An in-depth understanding of the factors that affect the shape of the full-waveform signal is required in order to extract as much information as possible from the signal. A simple model of LIDAR propagation has been created which simulates the interaction of LIDAR energy with objects in a scene. A 2-dimensional model tree allows controlled manipulation of the geometric arrangement of branches and leaves with varying spectral properties. Results suggest complex interactions of the LIDAR energy with the tree canopy, including the occurrence of multiple bounces for energy reaching the ground under the canopy. Idealized sensor instrument response functions incorporated in the simulation illustrate a large impact on waveform shape. A waveform recording laser rangefinder has been built which will allow validation or model results; preliminary collection results are presented here.

  2. Simulating full-waveform LIDAR

    OpenAIRE

    Kim, Angela M.

    2009-01-01

    LIDAR (LIght Detection And Ranging) is used to remotely measure the threedimensional shapes and arrangements of objects with high efficiency and accuracy by making precise measurements of time-of-flight of pulses of light. Discrete return LIDAR systems provide a discrete series of elevation points corresponding to reflections from objects in the scene. Full-waveform LIDAR systems measure the intensity of light returned to the sensor continuously over a period of time. Relatively little r...

  3. Simulating full-waveform lidar

    Science.gov (United States)

    Kim, Angela M.; Olsen, Richard C.; Borges, Carlos F.

    2010-04-01

    A simple Monte Carlo model of laser propagation through a tree is presented which allows the simulation of fullwaveform LIDAR signatures. The model incorporates a LIDAR system and a 'natural' scene, including an atmosphere, tree and ground surface. The PROSPECT leaf reflectance model is incorporated to determine leaf radiometric properties. Changes in the scene such as varying material reflectance properties, sloped vs. flat ground, and comparisons of tree 'leaf-on' vs. 'leaf-off' conditions have been analyzed. Changes in the LIDAR system have also been studied, including the effects of changing laser wavelength, shape and length of transmitted pulses, and angle of transmission. Results of some of these simulations are presented.

  4. An Initialization Technique for the Waveform-Relaxation Circuit Simulation

    OpenAIRE

    1999-01-01

    This paper reports the development of the Cairo University Waveform Relaxation (CUWORX) simulator. In order to accelerate the convergence of the waveform relaxation (WR) in the presence of logic feedback, CUWORK is initialized via a logic simulator. This logic initialization scheme is shown to be highly effective for digital synchronous circuits. Additionally, this logic initialization scheme preserves fully the multi-rate properties of the WR algorithm.

  5. Waveform design and diversity for advanced radar systems

    CERN Document Server

    Gini, Fulvio

    2012-01-01

    In recent years, various algorithms for radar signal design, that rely heavily upon complicated processing and/or antenna architectures, have been suggested. These techniques owe their genesis to several factors, including revolutionary technological advances (new flexible waveform generators, high speed signal processing hardware, digital array radar technology, etc.) and the stressing performance requirements, often imposed by defence applications in areas such as airborne early warning and homeland security.Increasingly complex operating scenarios calls for sophisticated algorithms with the

  6. SIMULATION OF FULL-WAVEFORM LASER ALTIMETER ECHOWAVEFORM

    OpenAIRE

    Y. Lv; Tong, X. H.; Liu, S. J.; Xie, H; Luan, K. F.; Liu, J

    2016-01-01

    Change of globe surface height is an important factor to study human living environment. The Geoscience Laser Altimeter System (GLAS) on ICESat is the first laser-ranging instrument for continuous global observations of the Earth. In order to have a comprehensive understanding of full-waveform laser altimeter, this study simulated the operating mode of ICESat and modeled different terrains’ (platform terrain, slope terrain, and artificial terrain) echo waveforms based on the radar eq...

  7. Simulation of Full-Waveform Laser Altimeter Echowaveform

    Science.gov (United States)

    Lv, Y.; Tong, X. H.; Liu, S. J.; Xie, H.; Luan, K. F.; Liu, J.

    2016-06-01

    Change of globe surface height is an important factor to study human living environment. The Geoscience Laser Altimeter System (GLAS) on ICESat is the first laser-ranging instrument for continuous global observations of the Earth. In order to have a comprehensive understanding of full-waveform laser altimeter, this study simulated the operating mode of ICESat and modeled different terrains' (platform terrain, slope terrain, and artificial terrain) echo waveforms based on the radar equation. By changing the characteristics of the system and the targets, numerical echo waveforms can be achieved. Hereafter, we mainly discussed the factors affecting the amplitude and size (width) of the echoes. The experimental results implied that the slope of the terrain, backscattering coefficient and reflectivity, target height, target position in the footprint and area reacted with the pulse all can affect the energy distribution of the echo waveform and the receiving time. Finally, Gaussian decomposition is utilized to decompose the echo waveform. From the experiment, it can be noted that the factors which can affect the echo waveform and by this way we can know more about large footprint full-waveform satellite laser altimeter.

  8. Simulation of droplet transfer process and current waveform control of CO2 arc welding

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A simulation system used in the arc welding short-circuit transfer process and current waveform control process was developed in this paper. The simulation results are basically consistent with welding technical experiments. The simulation system can be used to simulate and test the current waveform control parameters with welding variables. By this simulation system, the influence regularities of the current waveform control parameters in the CO2 arc welding droplet short-circuit transfer process can be got. Moreover, the basic mode of real-time current waveform control can be also established by the simulation testing.

  9. Comparing Gravitational Waveform Extrapolation to Cauchy-Characteristic Extraction in Binary Black Hole Simulations

    CERN Document Server

    Taylor, Nicholas W; Reisswig, Christian; Scheel, Mark A; Chu, Tony; Kidder, Lawrence E; Szilagyi, Bela

    2013-01-01

    We extract gravitational waveforms from numerical simulations of black hole binaries computed using the Spectral Einstein Code. We compare two extraction methods: direct construction of the Newman-Penrose (NP) scalar $\\Psi_4$ at a finite distance from the source and Cauchy-characteristic extraction (CCE). The direct NP approach is simpler than CCE, but NP waveforms can be contaminated by near-zone effects---unless the waves are extracted at several distances from the source and extrapolated to infinity. Even then, the resulting waveforms can in principle be contaminated by gauge effects. In contrast, CCE directly provides, by construction, gauge-invariant waveforms at future null infinity. We verify the gauge invariance of CCE by running the same physical simulation using two different gauge conditions. We find that these two gauge conditions produce the same CCE waveforms but show differences in extrapolated-$\\Psi_4$ waveforms. We examine data from several different binary configurations and measure the domi...

  10. Comparing gravitational waveform extrapolation to Cauchy-characteristic extraction in binary black hole simulations

    Science.gov (United States)

    Taylor, Nicholas W.; Boyle, Michael; Reisswig, Christian; Scheel, Mark A.; Chu, Tony; Kidder, Lawrence E.; Szilágyi, Béla

    2013-12-01

    We extract gravitational waveforms from numerical simulations of black hole binaries computed using the Spectral Einstein Code. We compare two extraction methods: direct construction of the Newman-Penrose (NP) scalar Ψ4 at a finite distance from the source and Cauchy-characteristic extraction (CCE). The direct NP approach is simpler than CCE, but NP waveforms can be contaminated by near-zone effects—unless the waves are extracted at several distances from the source and extrapolated to infinity. Even then, the resulting waveforms can in principle be contaminated by gauge effects. In contrast, CCE directly provides, by construction, gauge-invariant waveforms at future null infinity. We verify the gauge invariance of CCE by running the same physical simulation using two different gauge conditions. We find that these two gauge conditions produce the same CCE waveforms but show differences in extrapolated-Ψ4 waveforms. We examine data from several different binary configurations and measure the dominant sources of error in the extrapolated-Ψ4 and CCE waveforms. In some cases, we find that NP waveforms extrapolated to infinity agree with the corresponding CCE waveforms to within the estimated error bars. However, we find that in other cases extrapolated and CCE waveforms disagree, most notably for m=0 “memory” modes.

  11. Microwave dynamic large signal waveform characterization of advanced InGaP HBT for power amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Lixin; Jin Zhi; Liu Xinyu, E-mail: zhaolixin@ime.ac.c [Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029 (China)

    2009-12-15

    In wireless mobile communications and wireless local area networks (WLAN), advanced InGaP HBT with power amplifiers are key components. In this paper, the microwave large signal dynamic waveform characteristics of an advanced InGaP HBT are investigated experimentally for 5.8 GHz power amplifier applications. The microwave large signal waveform distortions at various input power levels, especially at large signal level, are investigated and the reasons are analyzed. The output power saturation is also explained. These analyses will be useful for power amplifier designs. (semiconductor devices)

  12. Microwave dynamic large signal waveform characterization of advanced InGaP HBT for power amplifiers

    International Nuclear Information System (INIS)

    In wireless mobile communications and wireless local area networks (WLAN), advanced InGaP HBT with power amplifiers are key components. In this paper, the microwave large signal dynamic waveform characteristics of an advanced InGaP HBT are investigated experimentally for 5.8 GHz power amplifier applications. The microwave large signal waveform distortions at various input power levels, especially at large signal level, are investigated and the reasons are analyzed. The output power saturation is also explained. These analyses will be useful for power amplifier designs. (semiconductor devices)

  13. Computer simulation of short-circuiting transfer welding under waveform control on inverter power source

    Institute of Scientific and Technical Information of China (English)

    Yang Lijun; Feng Shengqiang; Dong Tianshun; Li Huan

    2007-01-01

    A simulation model is introduced about the non-linearity process of short-circuiting transfer in CO2 arc welding for displaying the interaction between the inverter power source and welding arc under waveform control. In the simulation model, the feedback signals of current and voltage are taken respectively at the different phase in a short circuit periodic time and applied to the PWM(pulse width modulation) module in a model of inverter power source to control the output of power source. The simulation operation about the dynamic process of CO2 short-circuiting transfer welding is implemented on the founded simulation model with a peak arc current of 400 A and a peak voltage of 35 V, producing the dynamic arc waveforms which can embody the effect of inverter harmonic wave. The simulating waveforms are close to that of welding experiments.

  14. Some advanced parametric methods for assessing waveform distortion in a smart grid with renewable generation

    Science.gov (United States)

    Alfieri, Luisa

    2015-12-01

    Power quality (PQ) disturbances are becoming an important issue in smart grids (SGs) due to the significant economic consequences that they can generate on sensible loads. However, SGs include several distributed energy resources (DERs) that can be interconnected to the grid with static converters, which lead to a reduction of the PQ levels. Among DERs, wind turbines and photovoltaic systems are expected to be used extensively due to the forecasted reduction in investment costs and other economic incentives. These systems can introduce significant time-varying voltage and current waveform distortions that require advanced spectral analysis methods to be used. This paper provides an application of advanced parametric methods for assessing waveform distortions in SGs with dispersed generation. In particular, the Standard International Electrotechnical Committee (IEC) method, some parametric methods (such as Prony and Estimation of Signal Parameters by Rotational Invariance Technique (ESPRIT)), and some hybrid methods are critically compared on the basis of their accuracy and the computational effort required.

  15. The NINJA-2 project: Detecting and characterizing gravitational waveforms modelled using numerical binary black hole simulations

    CERN Document Server

    :,; Abbott, B P; Abbott, R; Abbott, T; Abernathy, M R; Accadia, T; Acernese, F; Ackley, K; Adams, C; Adams, T; Addesso, P; Adhikari, R X; Affeldt, C; Agathos, M; Aggarwal, N; Aguiar, O D; Ain, A; Ajith, P; Alemic, A; Allen, B; Allocca, A; Amariutei, D; Andersen, M; Anderson, R; Anderson, S B; Anderson, W G; Arai, K; Araya, M C; Arceneaux, C; Areeda, J; Aston, S M; Astone, P; Aufmuth, P; Aulbert, C; Austin, L; Aylott, B E; Babak, S; Baker, P T; Ballardin, G; Ballmer, S W; Barayoga, J C; Barbet, M; Barish, B C; Barker, D; Barone, F; Barr, B; Barsotti, L; Barsuglia, M; Barton, M A; Bartos, I; Bassiri, R; Basti, A; Batch, J C; Bauchrowitz, J; Bauer, Th S; Behnke, B; Bejger, M; Beker, M G; Belczynski, C; Bell, A S; Bell, C; Bergmann, G; Bersanetti, D; Bertolini, A; Betzwieser, J; Beyersdorf, P T; Bilenko, I A; Billingsley, G; Birch, J; Biscans, S; Bitossi, M; Bizouard, M A; Black, E; Blackburn, J K; Blackburn, L; Blair, D; Bloemen, S; Blom, M; Bock, O; Bodiya, T P; Boer, M; Bogaert, G; Bogan, C; Bond, C; Bondu, F; Bonelli, L; Bonnand, R; Bork, R; Born, M; Boschi, V; Bose, Sukanta; Bosi, L; Bradaschia, C; Brady, P R; Braginsky, V B; Branchesi, M; Brau, J E; Briant, T; Bridges, D O; Brillet, A; Brinkmann, M; Brisson, V; Brooks, A F; Brown, D A; Brown, D D; Brückner, F; Buchman, S; Bulik, T; Bulten, H J; Buonanno, A; Burman, R; Buskulic, D; Buy, C; Cadonati, L; Cagnoli, G; Bustillo, J Calderón; Calloni, E; Camp, J B; Campsie, P; Cannon, K C; Canuel, B; Cao, J; Capano, C D; Carbognani, F; Carbone, L; Caride, S; Castiglia, A; Caudill, S; Cavaglià, M; Cavalier, F; Cavalieri, R; Celerier, C; Cella, G; Cepeda, C; Cesarini, E; Chakraborty, R; Chalermsongsak, T; Chamberlin, S J; Chao, S; Charlton, P; Chassande-Mottin, E; Chen, X; Chen, Y; Chincarini, A; Chiummo, A; Cho, H S; Chow, J; Christensen, N; Chu, Q; Chua, S S Y; Chung, S; Ciani, G; Clara, F; Clark, J A; Cleva, F; Coccia, E; Cohadon, P -F; Colla, A; Collette, C; Colombini, M; Cominsky, L; Constancio, M; Conte, A; Cook, D; Corbitt, T R; Cordier, M; Cornish, N; Corpuz, A; Corsi, A; Costa, C A; Coughlin, M W; Coughlin, S; Coulon, J -P; Countryman, S; Couvares, P; Coward, D M; Cowart, M; Coyne, D C; Coyne, R; Craig, K; Creighton, J D E; Crowder, S G; Cumming, A; Cunningham, L; Cuoco, E; Dahl, K; Canton, T Dal; Damjanic, M; Danilishin, S L; D'Antonio, S; Danzmann, K; Dattilo, V; Daveloza, H; Davier, M; Davies, G S; Daw, E J; Day, R; Dayanga, T; Debreczeni, G; Degallaix, J; Deléglise, S; Del Pozzo, W; Denker, T; Dent, T; Dereli, H; Dergachev, V; De Rosa, R; DeRosa, R T; DeSalvo, R; Dhurandhar, S; Díaz, M; Di Fiore, L; Di Lieto, A; Di Palma, I; Di Virgilio, A; Donath, A; Donovan, F; Dooley, K L; Doravari, S; Dossa, S; Douglas, R; Downes, T P; Drago, M; Drever, R W P; Driggers, J C; Du, Z; Dwyer, S; Eberle, T; Edo, T; Edwards, M; Effler, A; Eggenstein, H; Ehrens, P; Eichholz, J; Eikenberry, S S; Endrőczi, G; Essick, R; Etzel, T; Evans, M; Evans, T; Factourovich, M; Fafone, V; Fairhurst, S; Fang, Q; Farinon, S; Farr, B; Farr, W M; Favata, M; Fehrmann, H; Fejer, M M; Feldbaum, D; Feroz, F; Ferrante, I; Ferrini, F; Fidecaro, F; Finn, L S; Fiori, I; Fisher, R P; Flaminio, R; Fournier, J -D; Franco, S; Frasca, S; Frasconi, F; Frede, M; Frei, Z; Freise, A; Frey, R; Fricke, T T; Fritschel, P; Frolov, V V; Fulda, P; Fyffe, M; Gair, J; Gammaitoni, L; Gaonkar, S; Garufi, F; Gehrels, N; Gemme, G; Genin, E; Gennai, A; Ghosh, S; Giaime, J A; Giardina, K D; Giazotto, A; Gill, C; Gleason, J; Goetz, E; Goetz, R; Gondan, L; González, G; Gordon, N; Gorodetsky, M L; Gossan, S; Goßler, S; Gouaty, R; Gräf, C; Graff, P B; Granata, M; Grant, A; Gras, S; Gray, C; Greenhalgh, R J S; Gretarsson, A M; Groot, P; Grote, H; Grover, K; Grunewald, S; Guidi, G M; Guido, C; Gushwa, K; Gustafson, E K; Gustafson, R; Hammer, D; Hammond, G; Hanke, M; Hanks, J; Hanna, C; Hanson, J; Harms, J; Harry, G M; Harry, I W; Harstad, E D; Hart, M; Hartman, M T; Haster, C -J; Haughian, K; Heidmann, A; Heintze, M; Heitmann, H; Hello, P; Hemming, G; Hendry, M; Heng, I S; Heptonstall, A W; Heurs, M; Hewitson, M; Hild, S; Hoak, D; Hodge, K A; Holt, K; Hooper, S; Hopkins, P; Hosken, D J; Hough, J; Howell, E J; Hu, Y; Hughey, B; Husa, S; Huttner, S H; Huynh, M; Huynh-Dinh, T; Ingram, D R; Inta, R; Isogai, T; Ivanov, A; Iyer, B R; Izumi, K; Jacobson, M; James, E; Jang, H; Jaranowski, P; Ji, Y; Jiménez-Forteza, F; Johnson, W W; Jones, D I; Jones, R; Jonker, R J G; Ju, L; K, Haris; Kalmus, P; Kalogera, V; Kandhasamy, S; Kang, G; Kanner, J B; Karlen, J; Kasprzack, M; Katsavounidis, E; Katzman, W; Kaufer, H; Kawabe, K; Kawazoe, F; Kéfélian, F; Keiser, G M; Keitel, D; Kelley, D B; Kells, W; Khalaidovski, A; Khalili, F Y; Khazanov, E A; Kim, C; Kim, K; Kim, N; Kim, N G; Kim, Y -M; King, E J; King, P J; Kinzel, D L; Kissel, J S; Klimenko, S; Kline, J; Koehlenbeck, S; Kokeyama, K; Kondrashov, V; Koranda, S; Korth, W Z; Kowalska, I; Kozak, D B; Kremin, A; Kringel, V; Krishnan, B; Królak, A; Kuehn, G; Kumar, A; Kumar, P; Kumar, R; Kuo, L; Kutynia, A; Kwee, P; Landry, M; Lantz, B; Larson, S; Lasky, P D; Lawrie, C; Lazzarini, A; Lazzaro, C; Leaci, P; Leavey, S; Lebigot, E O; Lee, C -H; Lee, H K; Lee, H M; Lee, J; Leonardi, M; Leong, J R; Roux, A Le; Leroy, N; Letendre, N; Levin, Y; Levine, B; Lewis, J; Li, T G F; Libbrecht, K; Libson, A; Lin, A C; Littenberg, T B; Litvine, V; Lockerbie, N A; Lockett, V; Lodhia, D; Loew, K; Logue, J; Lombardi, A L; Lorenzini, M; Loriette, V; Lormand, M; Losurdo, G; Lough, J; Lubinski, M J; Lück, H; Luijten, E; Lundgren, A P; Lynch, R; Ma, Y; Macarthur, J; Macdonald, E P; MacDonald, T; Machenschalk, B; MacInnis, M; Macleod, D M; Magana-Sandoval, F; Mageswaran, M; Maglione, C; Mailand, K; Majorana, E; Maksimovic, I; Malvezzi, V; Man, N; Manca, G M; Mandel, I; Mandic, V; Mangano, V; Mangini, N; Mantovani, M; Marchesoni, F; Marion, F; Márka, S; Márka, Z; Markosyan, A; Maros, E; Marque, J; Martelli, F; Martin, I W; Martin, R M; Martinelli, L; Martynov, D; Marx, J N; Mason, K; Masserot, A; Massinger, T J; Matichard, F; Matone, L; Matzner, R A; Mavalvala, N; Mazumder, N; Mazzolo, G; McCarthy, R; McClelland, D E; McGuire, S C; McIntyre, G; McIver, J; McLin, K; Meacher, D; Meadors, G D; Mehmet, M; Meidam, J; Meinders, M; Melatos, A; Mendell, G; Mercer, R A; Meshkov, S; Messenger, C; Meyers, P; Miao, H; Michel, C; Mikhailov, E E; Milano, L; Milde, S; Miller, J; Minenkov, Y; Mingarelli, C M F; Mishra, C; Mitra, S; Mitrofanov, V P; Mitselmakher, G; Mittleman, R; Moe, B; Moesta, P; Mohan, M; Mohapatra, S R P; Moraru, D; Moreno, G; Morgado, N; Morriss, S R; Mossavi, K; Mours, B; Mow-Lowry, C M; Mueller, C L; Mueller, G; Mukherjee, S; Mullavey, A; Munch, J; Murphy, D; Murray, P G; Mytidis, A; Nagy, M F; Kumar, D Nanda; Nardecchia, I; Naticchioni, L; Nayak, R K; Necula, V; Nelemans, G; Neri, I; Neri, M; Newton, G; Nguyen, T; Nitz, A; Nocera, F; Nolting, D; Normandin, M E N; Nuttall, L K; Ochsner, E; O'Dell, J; Oelker, E; Oh, J J; Oh, S H; Ohme, F; Oppermann, P; O'Reilly, B; O'Shaughnessy, R; Osthelder, C; Ottaway, D J; Ottens, R S; Overmier, H; Owen, B J; Padilla, C; Pai, A; Palashov, O; Palomba, C; Pan, H; Pan, Y; Pankow, C; Paoletti, F; Paoletti, R; Papa, M A; Paris, H; Pasqualetti, A; Passaquieti, R; Passuello, D; Pedraza, M; Penn, S; Perreca, A; Phelps, M; Pichot, M; Pickenpack, M; Piergiovanni, F; Pierro, V; Pinard, L; Pinto, I M; Pitkin, M; Poeld, J; Poggiani, R; Poteomkin, A; Powell, J; Prasad, J; Premachandra, S; Prestegard, T; Price, L R; Prijatelj, M; Privitera, S; Prodi, G A; Prokhorov, L; Puncken, O; Punturo, M; Puppo, P; Qin, J; Quetschke, V; Quintero, E; Quiroga, G; Quitzow-James, R; Raab, F J; Rabeling, D S; Rácz, I; Radkins, H; Raffai, P; Raja, S; Rajalakshmi, G; Rakhmanov, M; Ramet, C; Ramirez, K; Rapagnani, P; Raymond, V; Re, V; Read, J; Reed, C M; Regimbau, T; Reid, S; Reitze, D H; Rhoades, E; Ricci, F; Riles, K; Robertson, N A; Robinet, F; Rocchi, A; Rodruck, M; Rolland, L; Rollins, J G; Romano, R; Romanov, G; Romie, J H; Rosińska, D; Rowan, S; Rüdiger, A; Ruggi, P; Ryan, K; Salemi, F; Sammut, L; Sandberg, V; Sanders, J R; Sannibale, V; Santiago-Prieto, I; Saracco, E; Sassolas, B; Sathyaprakash, B S; Saulson, P R; Savage, R; Scheuer, J; Schilling, R; Schnabel, R; Schofield, R M S; Schreiber, E; Schuette, D; Schutz, B F; Scott, J; Scott, S M; Sellers, D; Sengupta, A S; Sentenac, D; Sequino, V; Sergeev, A; Shaddock, D; Shah, S; Shahriar, M S; Shaltev, M; Shapiro, B; Shawhan, P; Shoemaker, D H; Sidery, T L; Siellez, K; Siemens, X; Sigg, D; Simakov, D; Singer, A; Singer, L; Singh, R; Sintes, A M; Slagmolen, B J J; Slutsky, J; Smith, J R; Smith, M; Smith, R J E; Smith-Lefebvre, N D; Son, E J; Sorazu, B; Souradeep, T; Sperandio, L; Staley, A; Stebbins, J; Steinlechner, J; Steinlechner, S; Stephens, B C; Steplewski, S; Stevenson, S; Stone, R; Stops, D; Strain, K A; Straniero, N; Strigin, S; Sturani, R; Stuver, A L; Summerscales, T Z; Susmithan, S; Sutton, P J; Swinkels, B; Tacca, M; Talukder, D; Tanner, D B; Tarabrin, S P; Taylor, R; ter Braack, A P M; Thirugnanasambandam, M P; Thomas, M; Thomas, P; Thorne, K A; Thorne, K S; Thrane, E; Tiwari, V; Tokmakov, K V; Tomlinson, C; Toncelli, A; Tonelli, M; Torre, O; Torres, C V; Torrie, C I; Travasso, F; Traylor, G; Tse, M; Ugolini, D; Unnikrishnan, C S; Urban, A L; Urbanek, K; Vahlbruch, H; Vajente, G; Valdes, G; Vallisneri, M; Brand, J F J van den; Broeck, C Van Den; van der Putten, S; van der Sluys, M V; van Heijningen, J; van Veggel, A A; Vass, S; Vasúth, M; Vaulin, R; Vecchio, A; Vedovato, G; Veitch, J; Veitch, P J; Venkateswara, K; Verkindt, D; Verma, S S; Vetrano, F; Viceré, A; Vincent-Finley, R; Vinet, J -Y; Vitale, S; Vo, T; Vocca, H; Vorvick, C; Vousden, W D; Vyachanin, S P; Wade, A; Wade, L; Wade, M; Walker, M; Wallace, L; Wang, M; Wang, X; Ward, R L; Was, M; Weaver, B; Wei, L -W; Weinert, M; Weinstein, A J; Weiss, R; Welborn, T; Wen, L; Wessels, P; West, M; Westphal, T; Wette, K; Whelan, J T; Whitcomb, S E; White, D J; Whiting, B F; Wiesner, K; Wilkinson, C; Williams, K; Williams, L; Williams, R; Williams, T; Williamson, A R; Willis, J L; Willke, B; Wimmer, M; Winkler, W; Wipf, C C; Wiseman, A G; Wittel, H; Woan, G; Worden, J; Yablon, J; Yakushin, I; Yamamoto, H; Yancey, C C; Yang, H; Yang, Z; Yoshida, S; Yvert, M; Zadrożny, A; Zanolin, M; Zendri, J -P; Zhang, Fan; Zhang, L; Zhao, C; Zhu, X J; Zucker, M E; Zuraw, S; Zweizig, J; Boyle, M; Brügmann, B; Buchman, L T; Campanelli, M; Chu, T; Etienne, Z B; Hannam, M; Healy, J; Hinder, I; Kidder, L E; Laguna, P; Liu, Y T; London, L; Lousto, C O; Lovelace, G; MacDonald, I; Marronetti, P; Mösta, P; Müller, D; Mundim, B C; Nakano, H; Paschalidis, V; Pekowsky, L; Pollney, D; Pfeiffer, H P; Ponce, M; Pürrer, M; Reifenberger, G; Reisswig, C; Santamaría, L; Scheel, M A; Shapiro, S L; Shoemaker, D; Sopuerta, C F; Sperhake, U; Szilágyi, B; Taylor, N W; Tichy, W; Tsatsin, P; Zlochower, Y

    2014-01-01

    The Numerical INJection Analysis (NINJA) project is a collaborative effort between members of the numerical relativity and gravitational-wave astrophysics communities. The purpose of NINJA is to study the ability to detect gravitational waves emitted from merging binary black holes and recover their parameters with next-generation gravitational-wave observatories. We report here on the results of the second NINJA project, NINJA-2, which employs 60 complete binary black hole hybrid waveforms consisting of a numerical portion modelling the late inspiral, merger, and ringdown stitched to a post-Newtonian portion modelling the early inspiral. In a "blind injection challenge" similar to that conducted in recent LIGO and Virgo science runs, we added 7 hybrid waveforms to two months of data recolored to predictions of Advanced LIGO and Advanced Virgo sensitivity curves during their first observing runs. The resulting data was analyzed by gravitational-wave detection algorithms and 6 of the waveforms were recovered w...

  16. Computational Intelligence and Wavelet Transform Based Metamodel for Efficient Generation of Not-Yet Simulated Waveforms

    Science.gov (United States)

    Oltean, Gabriel; Ivanciu, Laura-Nicoleta

    2016-01-01

    The design and verification of complex electronic systems, especially the analog and mixed-signal ones, prove to be extremely time consuming tasks, if only circuit-level simulations are involved. A significant amount of time can be saved if a cost effective solution is used for the extensive analysis of the system, under all conceivable conditions. This paper proposes a data-driven method to build fast to evaluate, but also accurate metamodels capable of generating not-yet simulated waveforms as a function of different combinations of the parameters of the system. The necessary data are obtained by early-stage simulation of an electronic control system from the automotive industry. The metamodel development is based on three key elements: a wavelet transform for waveform characterization, a genetic algorithm optimization to detect the optimal wavelet transform and to identify the most relevant decomposition coefficients, and an artificial neuronal network to derive the relevant coefficients of the wavelet transform for any new parameters combination. The resulted metamodels for three different waveform families are fully reliable. They satisfy the required key points: high accuracy (a maximum mean squared error of 7.1x10-5 for the unity-based normalized waveforms), efficiency (fully affordable computational effort for metamodel build-up: maximum 18 minutes on a general purpose computer), and simplicity (less than 1 second for running the metamodel, the user only provides the parameters combination). The metamodels can be used for very efficient generation of new waveforms, for any possible combination of dependent parameters, offering the possibility to explore the entire design space. A wide range of possibilities becomes achievable for the user, such as: all design corners can be analyzed, possible worst-case situations can be investigated, extreme values of waveforms can be discovered, sensitivity analyses can be performed (the influence of each parameter on the

  17. Recent Advances in Programmable Photonic-Assisted Ultrabroadband Radio-Frequency Arbitrary Waveform Generation

    CERN Document Server

    Rashidinejad, Amir; Weiner, Andrew M

    2015-01-01

    This paper reviews recent advances in photonic-assisted radio-frequency arbitrary waveform generation (RF-AWG), with emphasis on programmable ultrabroadband microwave and millimeter-wave waveforms. The key enabling components in these techniques are programmable optical pulse shaping, frequency-to-time mapping via dispersive propagation, and high-speed photodetection. The main advantages and challenges of several different photonic RF-AWG schemes are discussed. We further review some proof-of-concept demonstrations of ultrabroadband RF-AWG applications, including high-resolution ranging and ultrabroadband non-line-of-sight channel compensation. Finally, we present recent progress toward RF-AWG with increased time aperture and time-bandwidth product.

  18. Simulation of temporal waveform control of laser pulse by frequency chirping

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Yoshinori; Yoshida, Hidetsugu; Fujita, Hisanori; Nakai, Sadao [Osaka Univ., Suita (Japan). Inst. of Laser Engineering

    1998-09-01

    Arbitrary temporal waveform control can be achieved by means of amplifier gain control with a chirped laser pulse. In order to simulate precise waveforms of laser pulses, we developed a multilevel simulation code with transitions between each manifold. Using the developed code, we examined the generation of required temporal waveforms for laser fusion experiment. The maximum amount of chirping decreased considerably at low input intensity and large amplifier gain. In the case of the calculation for a specialized laser system (Gekko XII), a tailored pulse shape can be generated with less than 4 nm chirp, using the current modulation technique. Comparing the amplified pulses with chirping to those without chirping, peak intensity and energy up to peak were 2.34 and 1.41 times higher, while total energy was 0.528 times lower. It was indicated that frequency chirping is one of the most promising methods for generating the tailored pulses for future laser fusion experiments. (author)

  19. Simulation of temporal waveform control of laser pulse by frequency chirping

    International Nuclear Information System (INIS)

    Arbitrary temporal waveform control can be achieved by means of amplifier gain control with a chirped laser pulse. In order to simulate precise waveforms of laser pulses, we developed a multilevel simulation code with transitions between each manifold. Using the developed code, we examined the generation of required temporal waveforms for laser fusion experiment. The maximum amount of chirping decreased considerably at low input intensity and large amplifier gain. In the case of the calculation for a specialized laser system (Gekko XII), a tailored pulse shape can be generated with less than 4 nm chirp, using the current modulation technique. Comparing the amplified pulses with chirping to those without chirping, peak intensity and energy up to peak were 2.34 and 1.41 times higher, while total energy was 0.528 times lower. It was indicated that frequency chirping is one of the most promising methods for generating the tailored pulses for future laser fusion experiments. (author)

  20. Studies of waveform requirements for intermediate mass-ratio coalescence searches with advanced detectors

    OpenAIRE

    Smith, R. J. E.; Mandel, I; Vecchio, A.

    2013-01-01

    The coalescence of a stellar-mass compact object into an intermediate-mass black hole (intermediate mass-ratio coalescence; IMRAC) is an important astrophysical source for ground-based gravitational-wave interferometers in the so-called advanced configuration. However, the ability to carry out effective matched-filter based searches for these systems is limited by the lack of reliable waveforms. Here we consider binaries in which the intermediate-mass black hole has mass in the range 24 - 200...

  1. Estimation of dynamic friction of the Akatani landslide from seismic waveform inversion and numerical simulation

    Science.gov (United States)

    Yamada, Masumi; Mangeney, Anne; Matsushi, Yuki; Moretti, Laurent

    2016-06-01

    We performed numerical simulations of the 2011 deep-seated Akatani landslide in central Japan to understand the dynamic evolution of friction of the landslide. By comparing the forces obtained from numerical simulation to those resolved from seismic waveform inversion, the coefficient of the friction during sliding was investigated in the range of 0.1 to 0.4. The simulation assuming standard Coulomb friction shows that the forces obtained by the seismic waveform inversion are well explained using a constant friction of μ = 0.3. A small difference between the residuals of Coulomb simulation and a velocity-dependent simulation suggests that the coefficient of friction over the volume is well constrained as 0.3 most of time during sliding. It suggests the sudden loss of shearing resistance at the onset of sliding, i.e., sudden drop of the initial coefficient of friction in our model, which accelerates the deep-seated landslide. Our numerical simulation calibrated by seismic data provides the evolution of dynamic friction with a reasonable resolution in time, which is difficult to obtain from a conventional runout simulation, or seismic waveform inversion alone.

  2. A CO2 Waveform Simulator for Evaluating and Testing of Respiratory Gas Analyzers

    OpenAIRE

    Long, Christina; Orr, Joseph

    2011-01-01

    Introduction: This paper describes a carbon dioxide (CO2) waveform simulator designed to evaluate and test the performance of capnographs, which are clinically used respiratory gas analyzers that continuously measure CO2. Currently, capnographs are tested for minimum performance standards according to guidelines specified by the International Organization for Standardization (ISO) and the American Society for Testing and Materials (ASTM). However, capnographs that meet these guidelines are no...

  3. REAL AND SIMULATED WAVEFORM RECORDING LIDAR DATA IN BOREAL JUVENILE FOREST VEGETATION

    OpenAIRE

    Hovi, A.; Korpela, I.

    2013-01-01

    Airborne small-footprint LiDAR is replacing field measurements in regional-level forest inventories, but auxiliary field work is still required for the optimal management of young stands. Waveform (WF) recording sensors can provide a more detailed description of the vegetation compared to discrete return (DR) systems. Furthermore, knowing the shape of the signal facilitates comparisons between real data and those obtained with simulation tools. We performed a quantitative validation ...

  4. Simulation of Waveforms of a Ferrite Inductor with Saturation and Power Losses

    Directory of Open Access Journals (Sweden)

    Rosa Ana Salas

    2014-03-01

    Full Text Available We propose a model of an equivalent electrical circuit specifically designed for a ferrite inductor excited by a sinusoidal waveform. The purpose of this model is its use in a circuit simulator. We calculate the model parameters by means of Finite Elements in 2D which leads to significant computational advantages over the 3D model. We carry out the validation for a toroidal ferrite inductor by comparing the experimental results and computed ones. We consider the saturation and power losses in the core. In addition, we have tested the model for the case of square waveform in order to generalize the results. We find excellent agreement between the experimental data and the results obtained by numerical calculations.

  5. Towards advanced code simulators

    International Nuclear Information System (INIS)

    The Central Electricity Generating Board (CEGB) uses advanced thermohydraulic codes extensively to support PWR safety analyses. A system has been developed to allow fully interactive execution of any code with graphical simulation of the operator desk and mimic display. The system operates in a virtual machine environment, with the thermohydraulic code executing in one virtual machine, communicating via interrupts with any number of other virtual machines each running other programs and graphics drivers. The driver code itself does not have to be modified from its normal batch form. Shortly following the release of RELAP5 MOD1 in IBM compatible form in 1983, this code was used as the driver for this system. When RELAP5 MOD2 became available, it was adopted with no changes needed in the basic system. Overall the system has been used for some 5 years for the analysis of LOBI tests, full scale plant studies and for simple what-if studies. For gaining rapid understanding of system dependencies it has proved invaluable. The graphical mimic system, being independent of the driver code, has also been used with other codes to study core rewetting, to replay results obtained from batch jobs on a CRAY2 computer system and to display suitably processed experimental results from the LOBI facility to aid interpretation. For the above work real-time execution was not necessary. Current work now centers on implementing the RELAP 5 code on a true parallel architecture machine. Marconi Simulation have been contracted to investigate the feasibility of using upwards of 100 processors, each capable of a peak of 30 MIPS to run a highly detailed RELAP5 model in real time, complete with specially written 3D core neutronics and balance of plant models. This paper describes the experience of using RELAP5 as an analyzer/simulator, and outlines the proposed methods and problems associated with parallel execution of RELAP5

  6. Advanced full-waveform lidar data echo detection: assessing quality of derived terrain and tree height models in an alpine coniferous forest

    OpenAIRE

    Chauve, A; Véga, C.; Durrieu, S.; Bretar, F.; Allouis, T.; Pierrot Desilligny, M.; Puech, W.

    2009-01-01

    Small footprint full-waveform airborne lidar systems offer large opportunities for improved forest characterization. To take advantage of full-waveform information, this paper presents a new processing method based on the decomposition of waveforms into a sum of parametric functions. The method consists of an enhanced peak detection algorithm combined with advanced echo modelling including Gaussian and generalized Gaussian models. The study focuses on the qualification of the extracted geo...

  7. Optimizing spinning time-domain gravitational waveforms for advanced LIGO data analysis

    Science.gov (United States)

    Devine, Caleb; Etienne, Zachariah B.; McWilliams, Sean T.

    2016-06-01

    The spinning effective-one-body–numerical relativity (SEOBNR) series of gravitational wave approximants are among the best available for advanced LIGO data analysis. Unfortunately, SEOBNR codes as they currently exist within LALSuite are generally too slow to be directly useful for standard Markov-chain Monte Carlo-based parameter estimation (PE). Reduced-order models (ROMs) of SEOBNR have been developed for this purpose, but there is no known way to make ROMs of the full eight-dimensional intrinsic parameter space more efficient for PE than the SEOBNR codes directly. So as a proof of principle, we have sped up the original LALSuite SEOBNRv2 approximant code, which models waveforms from aligned-spin systems, by nearly 300x. Our optimized code shortens the timescale for conducting PE with this approximant to months, assuming a purely serial analysis, so that even modest parallelization combined with our optimized code will make running the full PE pipeline with SEOBNR codes directly a realistic possibility. A number of our SEOBNRv2 optimizations have already been applied to SEOBNRv3, a new approximant capable of modeling sources with all eight (precessing) intrinsic degrees of freedom. We anticipate that once all of our optimizations have been applied to SEOBNRv3, a similar speed-up may be achieved.

  8. Optimizing spinning time-domain gravitational waveforms for Advanced LIGO data analysis

    CERN Document Server

    Devine, Caleb; McWilliams, Sean T

    2016-01-01

    The Spinning Effective One Body-Numerical Relativity (SEOBNR) series of gravitational wave approximants are among the best available for Advanced LIGO data analysis. Unfortunately, SEOBNR codes as they currently exist within LALSuite are generally too slow to be directly useful for standard Markov-Chain Monte Carlo-based parameter estimation (PE). Reduced-Order Models (ROMs) of SEOBNR have been developed for this purpose, but there is no known way to make ROMs of the full eight-dimensional intrinsic parameter space more efficient for PE than the SEOBNR codes directly. So as a proof of principle, we have sped up the original LALSuite SEOBNRv2 approximant code, which models waveforms from aligned-spin systems, by about 280x. Our optimized code shortens the timescale for conducting PE with this approximant to months, assuming a purely serial analysis, so that even modest parallelization combined with our optimized code will make running the full PE pipeline with SEOBNR codes directly a realistic possibility. A n...

  9. Studies of waveform requirements for intermediate mass-ratio coalescence searches with advanced detectors

    CERN Document Server

    Smith, R J E; Vechhio, A

    2013-01-01

    The coalescence of a stellar-mass compact object into an intermediate-mass black hole (intermediate mass-ratio coalescence; IMRAC) is an important astrophysical source for ground-based gravitational-wave interferometers in the so-called advanced configuration. However, the ability to carry out effective matched-filter based searches for these systems is limited by the lack of reliable waveforms. Here we consider binaries in which the intermediate-mass black hole has mass in the range 24 - 200 solar masses with a stellar-mass companion having masses in the range 1.4 - 18.5 solar masses. In addition, we constrain the mass ratios, q, of the binaries to be in the range 1/140 < q < 1/10 and we restrict our study to the case of circular binaries with non-spinning components. We investigate the relative contribution to the signal-to-noise ratio (SNR) of the three different phases of the coalescence: inspiral, merger and ringdown. We show that merger and ringdown contribute to a substantial fraction of the tota...

  10. Searching for gravitational-waves from compact binary coalescences while dealing with challenges of real data and simulated waveforms

    Science.gov (United States)

    Dayanga, Waduthanthree Thilina

    Albert Einstein's general theory of relativity predicts the existence of gravitational waves (GWs). Direct detection of GWs will provide enormous amount of new information about physics, astronomy and cosmology. Scientists around the world are currently working towards the first direct detection of GWs. The global network of ground-based GW detectors are currently preparing for their first advanced detector Science runs. In this thesis we focus on detection of GWs from compact binary coalescence (CBC) systems. Ability to accurately model CBC GW waveforms makes them the most promising source for the first direct detection of GWs. In this thesis we try to address several challenges associated with detecting CBC signals buried in ground-based GW detector data for past and future searches. Data analysis techniques we employ to detect GW signals assume detector noise is Gaussian and stationary. However, in reality, detector data is neither Gaussian nor stationary. To estimate the performance loss due to these features, we compare the efficiencies of detecting CBC signals in simulated Gaussian and real data. Additionally, we also demonstrate the effectiveness of multi-detector signal based consistency tests such ad null-stream. Despite, non-Gaussian and non-stationary features of real detector data, with effective data quality studies and signal-based vetoes we can approach the performance of Gaussian and stationary data. As we are moving towards advanced detector era, it is important to be prepared for future CBC searches. In this thesis we investigate the performances of non-spinning binary black hole (BBH) searches in simulated Gaussian using advanced detector noise curves predicted for 2015--2016. In the same study, we analyze the GW detection probabilities of latest pN-NR hybrid waveforms submitted to second version of Numerical Injection Analysis (NINJA-2) project. The main motivation for this study is to understand the ability to detect realistic BBH signals of

  11. Crosshole Tomography, Waveform Inversion, and Anisotropy: A Combined Approach Using Simulated Annealing

    Science.gov (United States)

    Afanasiev, M.; Pratt, R. G.; Kamei, R.; McDowell, G.

    2012-12-01

    Crosshole seismic tomography has been used by Vale to provide geophysical images of mineralized massive sulfides in the Eastern Deeps deposit at Voisey's Bay, Labrador, Canada. To date, these data have been processed using traveltime tomography, and we seek to improve the resolution of these images by applying acoustic Waveform Tomography. Due to the computational cost of acoustic waveform modelling, local descent algorithms are employed in Waveform Tomography; due to non-linearity an initial model is required which predicts first-arrival traveltimes to within a half-cycle of the lowest frequency used. Because seismic velocity anisotropy can be significant in hardrock settings, the initial model must quantify the anisotropy in order to meet the half-cycle criterion. In our case study, significant velocity contrasts between the target massive sulfides and the surrounding country rock led to difficulties in generating an accurate anisotropy model through traveltime tomography, and our starting model for Waveform Tomography failed the half-cycle criterion at large offsets. We formulate a new, semi-global approach for finding the best-fit 1-D elliptical anisotropy model using simulated annealing. Through random perturbations to Thompson's ɛ parameter, we explore the L2 norm of the frequency-domain phase residuals in the space of potential anisotropy models: If a perturbation decreases the residuals, it is always accepted, but if a perturbation increases the residuals, it is accepted with the probability P = exp(-(Ei-E)/T). This is the Metropolis criterion, where Ei is the value of the residuals at the current iteration, E is the value of the residuals for the previously accepted model, and T is a probability control parameter, which is decreased over the course of the simulation via a preselected cooling schedule. Convergence to the global minimum of the residuals is guaranteed only for infinitely slow cooling, but in practice good results are obtained from a variety

  12. Simulation of Large Footprint Lidar Waveforms from Forests: Analysis of the Sensitivity of Height Estimates to Footprint Characteristics

    Science.gov (United States)

    Pang, Y.; Lefsky, M.; Sun, G.; Li, Z.

    2008-12-01

    A spaceborne lidar mission would serve multiple scientific purposes including remote sensing of ecosystem structure and carbon storage, terrestrial and sea ice topography and monitoring of ice sheets. Some spaceborne lidar mission designs include the possibility that a lidar sensor would share a platform with another sensor. To reconcile multiple mission goals and sensor requirements, detailed knowledge of the sensitivity of sensor performance to aspects of mission design is required. Two important aspects of sensor design are footprint size and off-nadir pointing angle. This research uses radiative transfer and waveform synthesis models to investigate the sensitivity of forest height estimates to footprint size and off-nadir pointing and their interaction, over a range of forest canopy properties. An individual-based forest model was used to simulate stands of mixed conifer forest in the Tahoe National Forest (Northern California, USA) and stands of deciduous forests in the Bartlett Experimental Forest (New Hampshire, USA); waveforms were simulated from the forest model's output. A waveform synthesis method was used to create waveforms using airborne lidar data collected at these sites and a site in Dayekou Experimental Forest (Gansu, China). Data in the Tahoe and Bartlett study areas were collected conventionally; at the Dayekou test site, airborne lidar data were collected from five overlapping flight lines with different observation angles. Off-nadir angles varied from 0 to 16 degrees with a 25 m diameter footprint size. Preliminary results show that as the off-nadir angle increases, the intensity of the waveform ground return decreases and the vegetation return intensity increases. Over flat terrain, good linear relationships between waveform shape indices and maximum and mean tree height were found with different off-nadir angles. As terrain slope increases, our ability to retrieve canopy height decreases, and each off-nadir angle must be considered

  13. Toward Improved Nuclear Explosion Monitoring With Complete Waveform Simulations Using Three-Dimensional Models and Parallel Computing

    Science.gov (United States)

    Vorobiev, O.; Antoun, T.; Rodgers, A.; Matzel, E.; Myers, S.; Walter, W.; Petersson, A.; Bono, C.; Sjogreen, B.

    2008-12-01

    Next generation methods for lowering seismic monitoring thresholds and reducing uncertainties will likely rely on complete waveform simulations using three-dimensional (3D) earth models. Recent advances in numerical methods for both non-linear (shock wave) and linear (anelastic, seismic wave) propagation, improved 3D models and the steady growth of parallel computing promise to improve the accuracy and efficiency of explosion simulations. These methods implemented in new computer codes can advance physics-based understanding of nuclear explosions as well as the propagation effects caused by path-dependent earth structure. This presentation will summarize new 3D modeling capabilities developed to improve understanding of the seismic waves emerging from an explosion. Specifically we are working in three thrust areas: 1) computation of regional distance intermediate-period (50-10 seconds) synthetic seismograms in 3D earth models to assess the ability of these models to predict observed seismograms from well-characterized events; 2) coupling of non-linear hydrodynamic simulations of explosion shock waves with an anelastic finite difference code for modeling the dependence of seismic wave observables on explosion emplacement conditions and near-source heterogeneity; and 3) implementation of surface topography in our anelastic finite difference code to include scattering and mode-conversion due to a non-planar free surface. Current 3D continental-to-global scale seismic models represent long-wavelength (greater than 100 km) heterogeneity. We are investigating the efficacy of current 3D models to predict complete intermediate (50- 10 seconds) waveforms for well-characterized events (mostly earthquakes) using the spectral element code, SPECFEM3D. Intermediate period seismograms for crustal events at regional distance are strongly impacted by path propagation effects due to laterally variable crustal and upper mantle structure. We are also modeling shock wave propagation

  14. SPIDYAN, a MATLAB library for simulating pulse EPR experiments with arbitrary waveform excitation.

    Science.gov (United States)

    Pribitzer, Stephan; Doll, Andrin; Jeschke, Gunnar

    2016-02-01

    Frequency-swept chirp pulses, created with arbitrary waveform generators (AWGs), can achieve inversion over a range of several hundreds of MHz. Such passage pulses provide defined flip angles and increase sensitivity. The fact that spectra are not excited at once, but single transitions are passed one after another, can cause new effects in established pulse EPR sequences. We developed a MATLAB library for simulation of pulse EPR, which is especially suited for modeling spin dynamics in ultra-wideband (UWB) EPR experiments, but can also be used for other experiments and NMR. At present the command line controlled SPin DYnamics ANalysis (SPIDYAN) package supports one-spin and two-spin systems with arbitrary spin quantum numbers. By providing the program with appropriate spin operators and Hamiltonian matrices any spin system is accessible, with limits set only by available memory and computation time. Any pulse sequence using rectangular and linearly or variable-rate frequency-swept chirp pulses, including phase cycling can be quickly created. To keep track of spin evolution the user can choose from a vast variety of detection operators, including transition selective operators. If relaxation effects can be neglected, the program solves the Liouville-von Neumann equation and propagates spin density matrices. In the other cases SPIDYAN uses the quantum mechanical master equation and Liouvillians for propagation. In order to consider the resonator response function, which on the scale of UWB excitation limits bandwidth, the program includes a simple RLC circuit model. Another subroutine can compute waveforms that, for a given resonator, maintain a constant critical adiabaticity factor over the excitation band. Computational efficiency is enhanced by precomputing propagator lookup tables for the whole set of AWG output levels. The features of the software library are discussed and demonstrated with spin-echo and population transfer simulations. PMID:26773526

  15. SPIDYAN, a MATLAB library for simulating pulse EPR experiments with arbitrary waveform excitation

    Science.gov (United States)

    Pribitzer, Stephan; Doll, Andrin; Jeschke, Gunnar

    2016-02-01

    Frequency-swept chirp pulses, created with arbitrary waveform generators (AWGs), can achieve inversion over a range of several hundreds of MHz. Such passage pulses provide defined flip angles and increase sensitivity. The fact that spectra are not excited at once, but single transitions are passed one after another, can cause new effects in established pulse EPR sequences. We developed a MATLAB library for simulation of pulse EPR, which is especially suited for modeling spin dynamics in ultra-wideband (UWB) EPR experiments, but can also be used for other experiments and NMR. At present the command line controlled SPin DYnamics ANalysis (SPIDYAN) package supports one-spin and two-spin systems with arbitrary spin quantum numbers. By providing the program with appropriate spin operators and Hamiltonian matrices any spin system is accessible, with limits set only by available memory and computation time. Any pulse sequence using rectangular and linearly or variable-rate frequency-swept chirp pulses, including phase cycling can be quickly created. To keep track of spin evolution the user can choose from a vast variety of detection operators, including transition selective operators. If relaxation effects can be neglected, the program solves the Liouville-von Neumann equation and propagates spin density matrices. In the other cases SPIDYAN uses the quantum mechanical master equation and Liouvillians for propagation. In order to consider the resonator response function, which on the scale of UWB excitation limits bandwidth, the program includes a simple RLC circuit model. Another subroutine can compute waveforms that, for a given resonator, maintain a constant critical adiabaticity factor over the excitation band. Computational efficiency is enhanced by precomputing propagator lookup tables for the whole set of AWG output levels. The features of the software library are discussed and demonstrated with spin-echo and population transfer simulations.

  16. Real and Simulated Waveform Recording LIDAR Data in Boreal Juvenile Forest Vegetation

    Science.gov (United States)

    Hovi, A.; Korpela, I.

    2013-05-01

    Airborne small-footprint LiDAR is replacing field measurements in regional-level forest inventories, but auxiliary field work is still required for the optimal management of young stands. Waveform (WF) recording sensors can provide a more detailed description of the vegetation compared to discrete return (DR) systems. Furthermore, knowing the shape of the signal facilitates comparisons between real data and those obtained with simulation tools. We performed a quantitative validation of a Monte Carlo ray tracing (MCRT) -based LiDAR simulator against real data and used simulations and empirical data to study the WF recording LiDAR for the classification of boreal juvenile forest vegetation. Geometric-optical models of three common species were used as input for the MCRT model. Simulated radiometric and geometric WF features were in good agreement with the real data, and interspecies differences were preserved. We used the simulator to study the effects of sensor parameters on species classification performance. An increase in footprint size improved the classification accuracy up to a certain footprint size, while the emitted pulse width and the WF sampling rate had minor effects. Analyses on empirical data showed small improvement in performance compared to existing studies, when classifying seedling stand vegetation to four operational classes. The results on simulator validation serve as a basis for the future use of simulation models e.g. in LiDAR survey planning or in the simulation of synthetic training data, while the empirical findings clarify the potential of WF LiDAR data in the inventory chain for the operational forest management planning in Finland.

  17. Factors influencing the renal arterial Doppler waveform: a simulation study using an electrical circuit model (secondary publication

    Directory of Open Access Journals (Sweden)

    Chang Kyu Sung

    2016-01-01

    Full Text Available Purpose: The goal of this study was to evaluate the effect of vascular compliance, resistance, and pulse rate on the resistive index (RI by using an electrical circuit model to simulate renal blood flow. Methods: In order to analyze the renal arterial Doppler waveform, we modeled the renal blood-flow circuit with an equivalent simple electrical circuit containing resistance, inductance, and capacitance. The relationships among the impedance, resistance, and compliance of the circuit were derived from well-known equations, including Kirchhoff’s current law for alternating current circuits. Simulated velocity-time profiles for pulsatile flow were generated using Mathematica (Wolfram Research and the influence of resistance, compliance, and pulse rate on waveforms and the RI was evaluated. Results: Resistance and compliance were found to alter the waveforms independently. The impedance of the circuit increased with increasing proximal compliance, proximal resistance, and distal resistance. The impedance decreased with increasing distal compliance. The RI of the circuit decreased with increasing proximal compliance and resistance. The RI increased with increasing distal compliance and resistance. No positive correlation between impedance and the RI was found. Pulse rate was found to be an extrinsic factor that also influenced the RI. Conclusion: This simulation study using an electrical circuit model led to a better understanding of the renal arterial Doppler waveform and the RI, which may be useful for interpreting Doppler findings in various clinical settings.

  18. Factors influencing the renal arterial Doppler waveform: a simulation study using an electrical circuit model (secondary publication)

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Chang Kyu [Dept. of Radiology, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul (Korea, Republic of); Han, Bong Soo [Dept. of Radiological Science, College of Health Science, Yonsei University, Wonju (Korea, Republic of); Kim, Seung Hyup [Dept. of Radiology, Institute of Radiation Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2016-01-15

    The goal of this study was to evaluate the effect of vascular compliance, resistance, and pulse rate on the resistive index (RI) by using an electrical circuit model to simulate renal blood flow. In order to analyze the renal arterial Doppler waveform, we modeled the renal blood-flow circuit with an equivalent simple electrical circuit containing resistance, inductance, and capacitance. The relationships among the impedance, resistance, and compliance of the circuit were derived from well-known equations, including Kirchhoff’s current law for alternating current circuits. Simulated velocity-time profiles for pulsatile flow were generated using Mathematica (Wolfram Research) and the influence of resistance, compliance, and pulse rate on waveforms and the RI was evaluated. Resistance and compliance were found to alter the waveforms independently. The impedance of the circuit increased with increasing proximal compliance, proximal resistance, and distal resistance. The impedance decreased with increasing distal compliance. The RI of the circuit decreased with increasing proximal compliance and resistance. The RI increased with increasing distal compliance and resistance. No positive correlation between impedance and the RI was found. Pulse rate was found to be an extrinsic factor that also influenced the RI. This simulation study using an electrical circuit model led to a better understanding of the renal arterial Doppler waveform and the RI, which may be useful for interpreting Doppler findings in various clinical settings.

  19. Advances in the Use of Waveform Inversion for Modeling Mantle Elastic Structure

    Science.gov (United States)

    Panning, M. P.; Romanowicz, B.

    2002-12-01

    Seismic tomography is a useful tool in determining structure and dynamics of the Earth's mantle. While early models depended primarily on short period travel times and surface wave phase velocities, using full seismic waveforms of both surface waves and body waves provides opportunities for improved resolution, especially in the lower mantle, when appropriate sensitivity kernels are used (e.g. Li and Romanowicz, 1996; Mégnin and Romanowicz, 2000). So far, our efforts in elastic waveform inversion have been limited primarily to shear velocity models. This is chiefly due to computational resources needed to produce the synthetic waveforms and sensitivity kernels for the higher frequency data required for P inversions. Recent tests, however, have suggested that even a dataset of body waveforms filtered to periods greater than 32 seconds had some P sensitivity, and could produce a reasonable 3D mantle velocity model. Based on these preliminary results, we have expanded our dataset to shorter periods, to include body waves with period greater than 16 seconds. Using this dataset, we will invert for a mantle P velocity model using nonlinear asymptotic coupling theory (NACT), (Li and Romanowicz, 1996), which allows us to divide the seismogram at a given station into several wavepackets which can be weighted individually to maximize the coverage in poorly sampled areas of the mantle. To invert for P structure, one of our approaches has been to fix the S structure to a previously developed tomographic model and invert for P velocity starting from the spherically symmetric model. Although care is taken to select wavepackets which maximize P sensitivity and minimize S sensitivity, much waveform data is still sensitive to SV velocity structure due to the coupling of P and SV energy. Most available S velocity models, however, are either based primarily on SH sensitive data or a mixed dataset, so accounting for anisotropy is also important. We present progress in developing

  20. Surrogate waveform models

    Science.gov (United States)

    Blackman, Jonathan; Field, Scott; Galley, Chad; Scheel, Mark; Szilagyi, Bela; Tiglio, Manuel

    2015-04-01

    With the advanced detector era just around the corner, there is a strong need for fast and accurate models of gravitational waveforms from compact binary coalescence. Fast surrogate models can be built out of an accurate but slow waveform model with minimal to no loss in accuracy, but may require a large number of evaluations of the underlying model. This may be prohibitively expensive if the underlying is extremely slow, for example if we wish to build a surrogate for numerical relativity. We examine alternate choices to building surrogate models which allow for a more sparse set of input waveforms. Research supported in part by NSERC.

  1. The NINJA-2 project: Detecting and characterizing gravitational waveforms modelled using numerical binary black hole simulations

    OpenAIRE

    Aasi, J.; Abbott, B.P.; Abbott, R.; Abbott, T.; Abernathy, M. R.; Accadia, T.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Lewis, J.; Barone, F; Li, T. G. F.; Libbrecht, K.

    2014-01-01

    The Numerical INJection Analysis (NINJA) project is a collaborative effort between members of the numerical relativity and gravitational-wave (GW) astrophysics communities. The purpose of NINJA is to study the ability to detect GWs emitted from merging binary black holes (BBH) and recover their parameters with next-generation GW observatories. We report here on the results of the second NINJA project, NINJA-2, which employs 60 complete BBH hybrid waveforms consisting of a numerical portion mo...

  2. Estimation of Dynamic Friction Process of the Akatani Landslide Based on the Waveform Inversion and Numerical Simulation

    Science.gov (United States)

    Yamada, M.; Mangeney, A.; Moretti, L.; Matsushi, Y.

    2014-12-01

    Understanding physical parameters, such as frictional coefficients, velocity change, and dynamic history, is important issue for assessing and managing the risks posed by deep-seated catastrophic landslides. Previously, landslide motion has been inferred qualitatively from topographic changes caused by the event, and occasionally from eyewitness reports. However, these conventional approaches are unable to evaluate source processes and dynamic parameters. In this study, we use broadband seismic recordings to trace the dynamic process of the deep-seated Akatani landslide that occurred on the Kii Peninsula, Japan, which is one of the best recorded large slope failures. Based on the previous results of waveform inversions and precise topographic surveys done before and after the event, we applied numerical simulations using the SHALTOP numerical model (Mangeney et al., 2007). This model describes homogeneous continuous granular flows on a 3D topography based on a depth averaged thin layer approximation. We assume a Coulomb's friction law with a constant friction coefficient, i. e. the friction is independent of the sliding velocity. We varied the friction coefficients in the simulation so that the resulting force acting on the surface agrees with the single force estimated from the seismic waveform inversion. Figure shows the force history of the east-west components after the band-pass filtering between 10-100 seconds. The force history of the simulation with frictional coefficient 0.27 (thin red line) the best agrees with the result of seismic waveform inversion (thick gray line). Although the amplitude is slightly different, phases are coherent for the main three pulses. This is an evidence that the point-source approximation works reasonably well for this particular event. The friction coefficient during the sliding was estimated to be 0.38 based on the seismic waveform inversion performed by the previous study and on the sliding block model (Yamada et al., 2013

  3. Holistic Investigation of Corona Discharge: Impulse Current Waveform and Phase-resolved Measurement, Analysis and Simulation%Holistic Investigation of Corona Discharge: Impulse Current Waveform and Phase-resolved Measurement, Analysis and Simulation

    Institute of Scientific and Technical Information of China (English)

    Suwarno

    2011-01-01

    Partial discharge(PD) is one of the most important phenomenon in high voltage insulations. In most cases, the appearance of partial discharges is related to insulation defects. Understanding partial discharges is important for diagnosis on insulation condition. Corona discharges appear when extremely high electric field appears on the conductor surface exceeding the electric field strength of the gas. The high electric field may occur at around protrusion with very sharp tip. This paper reported a holistic approach of corona discharge investigation. The needle--plane electrode system was used. The medium between the electrodes was air. The needle was made from steel with radius of curvature of 3 μm (Ogura needle). Sinusoidal as well as triangular applied voltages were used. The waveform of the corona discharges was measured using a digital oscilloscope. The corona discharge pulses were measured using a phase--re- solved PD measurement system. The system was able to measure the magnitude (q) and phase angle position (9) of each PD pulses, as well as the number of discharge pulses (n). The role of applied voltage was investigated using phase--resolved analysis of corona discharge pulses through pulse sequence, pulse magnitude and pulse number analy- sis. Experimental results indicated that corona discharge current waveform was an impulse with rise time of about several ns and the impulse width of about 100 ns. The Fast Fourier Transform analysis indicated that the corona discharge current waveform had several spectrum peaks at frequency of 7.8 MHz, 85.9 MHz, 109.4 MHz and 195.3 MHz. The experimental results also showed that discharge pulses were concentrated around the peak of applied voltage for both sinusoidal and triangular voltages. The discharge magnitude, as well as its probability of occurrence, was strongly dependent on the instantaneous applied voltage. The shape of φn, as well as φ-q-n PD patterns, were strongly reflected by the shape

  4. Complete adiabatic waveform templates for a test mass in the Schwarzschild spacetime: VIRGO and advanced LIGO studies

    International Nuclear Information System (INIS)

    Post-Newtonian expansions of the binding energy and gravitational wave flux truncated at the same relative post-Newtonian order form the basis of the standard adiabatic approximation to the phasing of gravitational waves from inspiralling compact binaries. Viewed in terms of the dynamics of the binary, the standard approximation is equivalent to neglecting certain conservative post-Newtonian terms in the acceleration. In an earlier work, we had proposed a new complete adiabatic approximant constructed from the energy and flux functions. At the leading order, it employs the 2PN energy function rather than the 0PN one in the standard approximation, so that, effectively, the approximation corresponds to the dynamics where there are no missing post-Newtonian terms in the acceleration. In this paper, we compare the overlaps of the standard and complete adiabatic templates with the exact waveform in the adiabatic approximation of a test-mass motion in the Schwarzschild spacetime, for the VIRGO and the advanced LIGO noise spectra. It is found that the complete adiabatic approximants lead to a remarkable improvement in the effectualness at lower PN (<3PN) orders, while standard approximants of order ≥3PN provide a good lower bound to the complete approximants for the construction of effectual templates. Faithfulness of complete approximants is better than that of standard approximants except for a few post-Newtonian orders. Standard and complete approximants beyond the adiabatic approximation are also studied using the Lagrangian templates of Buonanno, Chen and Vallisneri

  5. Interactive Simulations and advanced Visualization with Modelica

    OpenAIRE

    Bellmann, Tobias

    2009-01-01

    In this paper a Modelica library for interactive simulation and advanced visualization called ExternalDevices is introduced and presented. Providing support for standard input devices like keyboard and joystick as well as for communication via UDP and shared memory, this library allows the user to interact with a running simulation and process the output data of the simulation in other processes capable of UDP connections. An advanced visualization system replaces t...

  6. Advanced circuit simulation using Multisim workbench

    CERN Document Server

    Báez-López, David; Cervantes-Villagómez, Ofelia Delfina

    2012-01-01

    Multisim is now the de facto standard for circuit simulation. It is a SPICE-based circuit simulator which combines analog, discrete-time, and mixed-mode circuits. In addition, it is the only simulator which incorporates microcontroller simulation in the same environment. It also includes a tool for printed circuit board design.Advanced Circuit Simulation Using Multisim Workbench is a companion book to Circuit Analysis Using Multisim, published by Morgan & Claypool in 2011. This new book covers advanced analyses and the creation of models and subcircuits. It also includes coverage of transmissi

  7. IMPROVED GROUND TRUTH IN SOUTHERN ASIA USING IN-COUNTRY DATA, ANALYST WAVEFORM REVIEW, AND ADVANCED ALGORITHMS

    Energy Technology Data Exchange (ETDEWEB)

    Engdahl, Eric, R.; Bergman, Eric, A.; Myers, Stephen, C.; Ryall, Floriana

    2009-06-19

    A new catalog of seismicity at magnitudes above 2.5 for the period 1923-2008 in the Iran region is assembled from arrival times reported by global, regional, and local seismic networks. Using in-country data we have formed new events, mostly at lower magnitudes that were not previously included in standard global earthquake catalogs. The magnitude completeness of the catalog varies strongly through time, complete to about magnitude 4.2 prior to 1998 and reaching a minimum of about 3.6 during the period 1998-2005. Of the 25,722 events in the catalog, most of the larger events have been carefully reviewed for proper phase association, especially for depth phases and to eliminate outlier readings, and relocated. To better understand the quality of the data set of arrival times reported by Iranian networks that are central to this study, many waveforms for events in Iran have been re-picked by an experienced seismic analyst. Waveforms at regional distances in this region are often complex. For many events this makes arrival time picks difficult to make, especially for smaller magnitude events, resulting in reported times that can be substantially improved by an experienced analyst. Even when the signal/noise ratio is large, re-picking can lead to significant differences. Picks made by our analyst are compared with original picks made by the regional networks. In spite of the obvious outliers, the median (-0.06 s) and spread (0.51 s) are small, suggesting that reasonable confidence can be placed in the picks reported by regional networks in Iran. This new catalog has been used to assess focal depth distributions throughout Iran. A principal result of this study is that the geographic pattern of depth distributions revealed by the relatively small number of earthquakes (~167) with depths constrained by waveform modeling (+/- 4 km) are now in agreement with the much larger number of depths (~1229) determined using reanalysis of ISC arrival-times (+/-10 km), within their

  8. Georgia Tech Catalog of Gravitational Waveforms

    OpenAIRE

    Jani, Karan; Healy, James; Clark, James A.; London, Lionel; Laguna, Pablo; Shoemaker, Deirdre

    2016-01-01

    This paper introduces a catalog of gravitational waveforms from the bank of simulations by the numerical relativity effort at Georgia Tech. Currently, the catalog consists of 452 distinct waveforms from more than 600 binary black hole simulations: 128 of the waveforms are from binaries with black hole spins aligned with the orbital angular momentum, and 324 are from precessing binary black hole systems. The waveforms from binaries with non-spinning black holes have mass-ratios $q = m_1/m_2 \\l...

  9. Nonlinear waveform generation.

    Science.gov (United States)

    Goldstein, L J; Rypins, E B

    1990-01-01

    We developed three analog logic SPICE (Simulation Program with Integrated Circuit Emphasis, developed at the University of California, Berkeley, CA) subcircuits, a voltage comparator and a nonlinear waveform generator to compliment the previously derived functions (Goldstein and Rypins, Comput. Methods Programs Biomed. 29 (1989) 161-172) that simplify modeling of physiologic systems. The logic elements are the 'AND', 'OR' and 'NOT' Boolean functions. In addition, we derived a voltage comparator for use in our composite waveform generator. All the circuits are analog so they can be incorporated into existing analog circuits while performing digital functions. PMID:2364683

  10. Advanced Vadose Zone Simulations Using TOUGH

    Energy Technology Data Exchange (ETDEWEB)

    Finsterle, S.; Doughty, C.; Kowalsky, M.B.; Moridis, G.J.; Pan,L.; Xu, T.; Zhang, Y.; Pruess, K.

    2007-02-01

    The vadose zone can be characterized as a complex subsurfacesystem in which intricate physical and biogeochemical processes occur inresponse to a variety of natural forcings and human activities. Thismakes it difficult to describe, understand, and predict the behavior ofthis specific subsurface system. The TOUGH nonisothermal multiphase flowsimulators are well-suited to perform advanced vadose zone studies. Theconceptual models underlying the TOUGH simulators are capable ofrepresenting features specific to the vadose zone, and of addressing avariety of coupled phenomena. Moreover, the simulators are integratedinto software tools that enable advanced data analysis, optimization, andsystem-level modeling. We discuss fundamental and computationalchallenges in simulating vadose zone processes, review recent advances inmodeling such systems, and demonstrate some capabilities of the TOUGHsuite of codes using illustrative examples.

  11. Comparing numerical and analytic approximate gravitational waveforms

    Science.gov (United States)

    Afshari, Nousha; Lovelace, Geoffrey; SXS Collaboration

    2016-03-01

    A direct observation of gravitational waves will test Einstein's theory of general relativity under the most extreme conditions. The Laser Interferometer Gravitational-Wave Observatory, or LIGO, began searching for gravitational waves in September 2015 with three times the sensitivity of initial LIGO. To help Advanced LIGO detect as many gravitational waves as possible, a major research effort is underway to accurately predict the expected waves. In this poster, I will explore how the gravitational waveform produced by a long binary-black-hole inspiral, merger, and ringdown is affected by how fast the larger black hole spins. In particular, I will present results from simulations of merging black holes, completed using the Spectral Einstein Code (black-holes.org/SpEC.html), including some new, long simulations designed to mimic black hole-neutron star mergers. I will present comparisons of the numerical waveforms with analytic approximations.

  12. Advances in Intelligent Modelling and Simulation Simulation Tools and Applications

    CERN Document Server

    Oplatková, Zuzana; Carvalho, Marco; Kisiel-Dorohinicki, Marek

    2012-01-01

    The human capacity to abstract complex systems and phenomena into simplified models has played a critical role in the rapid evolution of our modern industrial processes and scientific research. As a science and an art, Modelling and Simulation have been one of the core enablers of this remarkable human trace, and have become a topic of great importance for researchers and practitioners. This book was created to compile some of the most recent concepts, advances, challenges and ideas associated with Intelligent Modelling and Simulation frameworks, tools and applications. The first chapter discusses the important aspects of a human interaction and the correct interpretation of results during simulations. The second chapter gets to the heart of the analysis of entrepreneurship by means of agent-based modelling and simulations. The following three chapters bring together the central theme of simulation frameworks, first describing an agent-based simulation framework, then a simulator for electrical machines, and...

  13. Towards a Better Understanding of Forest Biophysical Parameters - Combining High Fidelity Simulations, Airborne Waveform Lidar, and Terrestrial Lidar Sensing

    Science.gov (United States)

    van Aardt, J. A.; Kelbe, D.; Romanczyk, P.; van Leeuwen, M.; Cawse-Nicholson, K.; Krause, K.; Kampe, T. U.

    2015-12-01

    The science community has come a long way from traditional, 2D imaging approaches to the assessment of ecosystem structure, function and composition. For example, waveform- (wlidar) and terrestrial lidar systems (TLS) present us with exciting opportunities for detailed, accurate and precise, and scalable structural characterization of vegetation. wlidar and TLS generally can be regarded as complementary i.e., airborne wlidar typically digitizes the entire backscattered energy profile at high spatial and vertical resolutions, while TLS samples dense 3D point clouds of the bottom-up vegetation structure. Research teams at Rochester Institute of Technology (RIT) have been collaborating with the National Ecological Observation Network (NEON) to assess vegetation structure and variation in the Pacific-Southwest (San Joaquin Experimental Range and Soaproot Saddle sites, CA) and Northeast (Harvard Forest, MA) domains. The teams collected airborne small-footprint wlidar data and in-situ TLS data for these sites and is taking a two-tiered (top-down and bottom-up) approach to forest structural assessment. We will present our work where we (i) studied wlidar signal attenuation throughout the canopy in a simulation environment - the attenuation correction factor was linearly proportional to the sum of the area under the proceeding Gaussians - and (ii) used the fine-scale stem structure extracted via TLS to reconstruct complex, but realistic, 3D forest environments for refined simulation studies. These studies indicate that we can potentially assess vegetation canopies remotely using a vertically-stratified approach with wlidar and use rapid-scan TLS technology to calibrate models predicated upon synoptic airborne systems. Other outputs of our approaches can be used for typical forest inventory, ecological parameter extraction, and new algorithm validation.

  14. Dynamic Simulations of Advanced Fuel Cycles

    Energy Technology Data Exchange (ETDEWEB)

    Steven J. Piet; Brent W. Dixon; Jacob J. Jacobson; Gretchen E. Matthern; David E. Shropshire

    2011-03-01

    Years of performing dynamic simulations of advanced nuclear fuel cycle options provide insights into how they could work and how one might transition from the current once-through fuel cycle. This paper summarizes those insights from the context of the 2005 objectives and goals of the U.S. Advanced Fuel Cycle Initiative (AFCI). Our intent is not to compare options, assess options versus those objectives and goals, nor recommend changes to those objectives and goals. Rather, we organize what we have learned from dynamic simulations in the context of the AFCI objectives for waste management, proliferation resistance, uranium utilization, and economics. Thus, we do not merely describe “lessons learned” from dynamic simulations but attempt to answer the “so what” question by using this context. The analyses have been performed using the Verifiable Fuel Cycle Simulation of Nuclear Fuel Cycle Dynamics (VISION). We observe that the 2005 objectives and goals do not address many of the inherently dynamic discriminators among advanced fuel cycle options and transitions thereof.

  15. 14 CFR Appendix H to Part 121 - Advanced Simulation

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Advanced Simulation H Appendix H to Part... Simulation This appendix provides guidelines and a means for achieving flightcrew training in advanced... simulator, as appropriate. Advanced Simulation Training Program For an operator to conduct Level C or...

  16. LISA parameter estimation using numerical merger waveforms

    CERN Document Server

    Thorpe, J I; Kelly, B J; Fahey, R P; Arnaud, K; Baker, J G

    2008-01-01

    Recent advances in numerical relativity provide a detailed description of the waveforms of coalescing massive black hole binaries (MBHBs), expected to be the strongest detectable LISA sources. We present a preliminary study of LISA's sensitivity to MBHB parameters using a hybrid numerical/analytic waveform for equal-mass, non-spinning holes. The Synthetic LISA software package is used to simulate the instrument response and the Fisher information matrix method is used to estimate errors in the parameters. Initial results indicate that inclusion of the merger signal can significantly improve the precision of some parameter estimates. For example, the median parameter errors for an ensemble of systems with total redshifted mass of one million Solar masses at a redshift of one were found to decrease by a factor of slightly more than two for signals with merger as compared to signals truncated at the Schwarzchild ISCO.

  17. LISA parameter estimation using numerical merger waveforms

    Energy Technology Data Exchange (ETDEWEB)

    Thorpe, J I; McWilliams, S T; Kelly, B J; Fahey, R P; Arnaud, K; Baker, J G, E-mail: James.I.Thorpe@nasa.go [NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771 (United States)

    2009-05-07

    Recent advances in numerical relativity provide a detailed description of the waveforms of coalescing massive black hole binaries (MBHBs), expected to be the strongest detectable LISA sources. We present a preliminary study of LISA's sensitivity to MBHB parameters using a hybrid numerical/analytic waveform for equal-mass, non-spinning holes. The Synthetic LISA software package is used to simulate the instrument response, and the Fisher information matrix method is used to estimate errors in the parameters. Initial results indicate that inclusion of the merger signal can significantly improve the precision of some parameter estimates. For example, the median parameter errors for an ensemble of systems with total redshifted mass of 10{sup 6} M{sub o-dot} at a redshift of z approx 1 were found to decrease by a factor of slightly more than two for signals with merger as compared to signals truncated at the Schwarzchild ISCO.

  18. LISA parameter estimation using numerical merger waveforms

    International Nuclear Information System (INIS)

    Recent advances in numerical relativity provide a detailed description of the waveforms of coalescing massive black hole binaries (MBHBs), expected to be the strongest detectable LISA sources. We present a preliminary study of LISA's sensitivity to MBHB parameters using a hybrid numerical/analytic waveform for equal-mass, non-spinning holes. The Synthetic LISA software package is used to simulate the instrument response, and the Fisher information matrix method is used to estimate errors in the parameters. Initial results indicate that inclusion of the merger signal can significantly improve the precision of some parameter estimates. For example, the median parameter errors for an ensemble of systems with total redshifted mass of 106 Mo-dot at a redshift of z ∼ 1 were found to decrease by a factor of slightly more than two for signals with merger as compared to signals truncated at the Schwarzchild ISCO.

  19. Assessment of training simulators with advanced models

    International Nuclear Information System (INIS)

    Training quality received by the nuclear power plants operators is related to the reliability degree reached by the models which constitute the calculation basis. TECNATOM began, in the middle of the 80's, the PWR and BWR training simulators upgrading to reproduce all type of transients with long term operation and a very high reliability degree. As a result of this, the Simulation Advanced Models Project (MAS) has been developed for both PWR and BWR simulators. The simulators software is the TRAC code running in real time on the CRAY X-MP 14 vectorial computer. The validation methodology followed in the MAS Project is based on the EPRI's one. The main goal is the detailed analysis of the variables and physical phenomena to validate ('dynamic modes') included in the validation transients matrix. The reference results are supplied by plant data or best estimate codes: TRAC-PF1/MOD1 and TRACG for PWR and BWR training simulators, respectively. This paper shows the main results of validation transients and the main conclusions: improvement of simulation scope and reliability, EOP's scenarios simulation with long term recovery and physical phenomena analysis similar to best estimate codes. (orig.) (13 refs., 17 figs., 4 tabs.)

  20. Advanced simulation for fast reactor design

    International Nuclear Information System (INIS)

    Full text: This talk broadly reviews recent research aimed at applying advanced simulation techniques specifically to fast neutron reactors. By advanced simulation we generally refer to attempts to do more science-based simulation - that is, to numerically solve the three-dimensional governing physical equations on fine scales and observe and study the holistic phenomena that emerge. In this way simulation is treated more akin to a traditional physical experiment, and can can be used both separately and in conjunction with physical experiments to develop more accurate predictive theories on reactor behavior. Many existing fast reactor modeling tools were developed for last generation's computational resources. They were built by engineers and physicists with deep physical insight - insight that both shaped and was informed by existing theory, and was underpinned by a vast repository of experimental data. Their general approach was to develop models that were tailored to varying degrees to the details of the reactor design, using free model parameters that were subsequently calibrated to match existing experimental data. The resulting codes were thus extremely useful for their specific purpose but highly limited in their predictive capability (neutronics to a lesser degree). They tended to represent more the state-of-the-art in our understanding rather than tools of exploration and innovation. Recently, a number of researchers have attempted to study the feasibility of solving more fundamental governing equations on realistic, three-dimensional geometries for different fast reactor sub-domains. This includes solving the Navier-Stokes equations for single-phase sodium flow (Direct Numerical Simulation, Large Eddie Simulation, and Reynolds Averaged Navier Stokes Equations) in the core, upper plenum, primary and intermediate loop, etc.; the non-homogenized transport equations at very fine group, angle, and energy discretization, and thermo-mechanical feedback based on

  1. Advanced ST plasma scenario simulations for NSTX

    International Nuclear Information System (INIS)

    Integrated scenario simulations are done for NSTX that address four primary milestones for developing advanced ST configurations: high β and high βN inductive discharges to study all aspects of ST physics in the high beta regime; non-inductively sustained discharges for flattop times greater than the skin time to study the various current drive techniques; non-inductively sustained discharges at high βfor flattop times much greater than a skin time which provides the integrated advanced ST target for NSTX; and non-solenoidal startup and plasma current rampup. The simulations done here use the Tokamak Simulation Code (TSC) and are based on a discharge 109070. TRANSP analysis of the discharge provided the thermal diffusivities for electrons and ions, the neutral beam (NB) deposition profile and other characteristics. CURRAY is used to calculate the High Harmonic Fast Wave (HHFW) heating depositions and current drive. GENRAY/CQL3D is used to establish the heating and CD deposition profiles for electron Bernstein waves (EBW). Analysis of the ideal MHD stability is done with JSOLVER, BALMSC, and PEST2. The simulations indicate that the integrated advanced ST plasma is reachable, obtaining stable plasmas with β ∼ 40% at βN's of 7.7-9, IP = 1.0 MA and BT = 0.35 T. The plasma is 100% non-inductive and has a flattop of 4 skin times. The resulting global energy confinement corresponds to a multiplier of H98(y,2) = 1.5. The simulations have demonstrated the importance of HHFW heating and CD, EBW off-axis CD, strong plasma shaping, density control, and early heating/H-mode transition for producing and optimizing these plasma configurations (author)

  2. Computer-controlled High Resolution Arbitrary Waveform Generator (HRAWG) for Focusing Beamforming Applications

    Science.gov (United States)

    Assef, Amauri Amorin; Maia, Joaquim Miguel; Costa, Eduardo Tavares

    In advanced ultrasound imaging systems, expensive high-end integrated analog front-ends have been traditionally used to support generation of arbitrary transmit waveforms, in addition to transmit focusing and apodization control. In this paper, we present a cost-effective computer-controlled reconfigurable high-resolution arbitrary waveform generator (HRAWG) that has been designed for ultrasound research, development and teaching at the Federal University of Technology (UTFPR), Brazil. The 8-channel transmit beamformer is fully controlled by a host computer in which a Matlab GUI with the Field II simulation program, allows easy and accurate control over the transmission parameters such as waveform, amplitude apodization and timing.

  3. Advanced numerical simulations of selected metallurgical units

    Directory of Open Access Journals (Sweden)

    G. Kokot

    2012-12-01

    Full Text Available Purpose: of this paper is to present numerical simulations of large structures in metallurgical industry. Some examples of finite element analysis are presented. The calculations were performed for the determining the stress effort of the metallurgical units mainly blast furnace, throath’s gas pipelines, hot blast stoves, etc. during the working conditions and for the repairing purpose.Design/methodology/approach: The way of conducting simulations and analysis were the finite element method connected with the optimization process.Findings: Performing the numerical analysis the changes in the structures design were applied what extremely influenced on the state effort and the durability of considered structures.Research limitations/implications: Development of the presented approach solving the coupled field and CFD problems, the application of the parallel computing and domain decomposition methods in the large structure simulations.Practical implications: Presented results shows the possibility of application the advanced computational methods in the computer aided engineering processes of designing and analysing the large structure as the metallurgical units are. It can dramatically influence on the recognizing of the effort stets and helps in the monitoring, overhauls and redesigning process. Those methods gives the global very precise information which cannot be obtain in other ways (analytical solutions, experimental methods.Originality/value: The paper present the original research results comes from the complex numerical simulations of the main metallurgical units in the blast furnace train. The original value of the paper is the introduction of the advanced finite element simulation in the field of iron steel industry structures design and developing.

  4. Motion control in advanced driving simulators

    OpenAIRE

    Elloumi, Hatem

    2006-01-01

    Driving simulators are advanced devices composed of four components: a virtual scene projected on a wide screen to imitate the road and the traffic, an audio system to play the driving sounds (horn, squeal of brakes, etc.), a car cockpit (including a real dashboard, the pedals and the seat of the driver) to copy the body position and the interaction of the driver with a real vehicle and finally a robot carrying the car cockpit to provide its motion. While the first three components could be c...

  5. Software Framework for Advanced Power Plant Simulations

    Energy Technology Data Exchange (ETDEWEB)

    John Widmann; Sorin Munteanu; Aseem Jain; Pankaj Gupta; Mark Moales; Erik Ferguson; Lewis Collins; David Sloan; Woodrow Fiveland; Yi-dong Lang; Larry Biegler; Michael Locke; Simon Lingard; Jay Yun

    2010-08-01

    This report summarizes the work accomplished during the Phase II development effort of the Advanced Process Engineering Co-Simulator (APECS). The objective of the project is to develop the tools to efficiently combine high-fidelity computational fluid dynamics (CFD) models with process modeling software. During the course of the project, a robust integration controller was developed that can be used in any CAPE-OPEN compliant process modeling environment. The controller mediates the exchange of information between the process modeling software and the CFD software. Several approaches to reducing the time disparity between CFD simulations and process modeling have been investigated and implemented. These include enabling the CFD models to be run on a remote cluster and enabling multiple CFD models to be run simultaneously. Furthermore, computationally fast reduced-order models (ROMs) have been developed that can be 'trained' using the results from CFD simulations and then used directly within flowsheets. Unit operation models (both CFD and ROMs) can be uploaded to a model database and shared between multiple users.

  6. 8mm Dicke辐射计波形仿真研究%The Research on 8 Millimeter Dicke Radiometer Waveform Simulation

    Institute of Scientific and Technical Information of China (English)

    刘杰; 陈云梅; 程春悦

    2011-01-01

    采用System view软件对从输入到天线的噪声信号到A/D采样之前的各个模块和辐射计线性度进行了波形的仿真研究,仿真结果和实际相符合,对辐射计的硬件实现提供了很好的指导作用.%Computer simulation has an important meaning in system analysis, design, research and performance testing. This paper simulates the waveform from the antenna's input noise signal to integrator's output signal (before A/D converter) and radiometer linearity using the system view software. The simulation result is accordant with actual case, so it gives instructional effect in hardware implement.

  7. Template Banks for Binary black hole searches with Numerical Relativity waveforms

    CERN Document Server

    Kumar, Prayush; Brown, Duncan A; Pfeiffer, Harald P; Cannon, Kipp; Boyle, Michael; Kidder, Lawrence E; Mroue, Abdul H; Scheel, Mark A; Szilagyi, Bela; Zenginoglu, Anil

    2013-01-01

    Gravitational waves (GW) from coalescing stellar-mass black hole binaries (BBH) are expected to be detected by the Advanced Laser Interferometer Gravitational-wave Observatory and Advanced Virgo. Detection searches operate by matched-filtering the detector data using a bank of waveform templates. Traditionally, template banks for BBH are constructed from intermediary analytical waveform models which are calibrated against numerical relativity simulations and which can be aluated for any choice of BBH parameters. This paper explores an alternative to the traditional approach, namely the construction of template banks directly from numerical BBH simulations. Using non-spinning BBH systems as an example, we demonstrate which regions of the mass-parameter plane can be covered with existing numerical BBH waveforms. We estimate the required number and required length of BBH simulations to cover the entire non-spinning BBH parameter plane up to mass-ratio 10, thus illustrating that our approach can be used to guide ...

  8. Multiscale full waveform inversion

    Science.gov (United States)

    Fichtner, Andreas; Trampert, Jeannot; Cupillard, Paul; Saygin, Erdinc; Taymaz, Tuncay; Capdeville, Yann; Villaseñor, Antonio

    2013-07-01

    We develop and apply a full waveform inversion method that incorporates seismic data on a wide range of spatio-temporal scales, thereby constraining the details of both crustal and upper-mantle structure. This is intended to further our understanding of crust-mantle interactions that shape the nature of plate tectonics, and to be a step towards improved tomographic models of strongly scale-dependent earth properties, such as attenuation and anisotropy. The inversion for detailed regional earth structure consistently embedded within a large-scale model requires locally refined numerical meshes that allow us to (1) model regional wave propagation at high frequencies, and (2) capture the inferred fine-scale heterogeneities. The smallest local grid spacing sets the upper bound of the largest possible time step used to iteratively advance the seismic wave field. This limitation leads to extreme computational costs in the presence of fine-scale structure, and it inhibits the construction of full waveform tomographic models that describe earth structure on multiple scales. To reduce computational requirements to a feasible level, we design a multigrid approach based on the decomposition of a multiscale earth model with widely varying grid spacings into a family of single-scale models where the grid spacing is approximately uniform. Each of the single-scale models contains a tractable number of grid points, which ensures computational efficiency. The multi-to-single-scale decomposition is the foundation of iterative, gradient-based optimization schemes that simultaneously and consistently invert data on all scales for one multi-scale model. We demonstrate the applicability of our method in a full waveform inversion for Eurasia, with a special focus on Anatolia where coverage is particularly dense. Continental-scale structure is constrained by complete seismic waveforms in the 30-200 s period range. In addition to the well-known structural elements of the Eurasian mantle

  9. Toward global waveform tomography of the whole mantle using SEM: Efficient simulation of the global wavefield using a homogenized crust

    Science.gov (United States)

    French, S. W.; Lekic, V.; Romanowicz, B. A.

    2010-12-01

    As global waveform-modeling schemes rooted in perturbation theory are supplanted by fully numerical alternatives, such as the Spectral Element Method (e.g. SEM: Komatitsch and Tromp, 2002), the improved wavefield accuracy for complex 3D structures also carries increased computational cost. Lekic and Romanowicz (2010) inverted waveforms of fundamental and higher mode surface waves for a radially anisotropic upper-mantle Vs model using SEM (SEMum). The SEM computations were made feasible by an appropriate choice of cutoff period (T≥ 60 s.), as well as the implementation of a homogenized anisotropic crustal layer based on fitting of short period group velocity dispersion curves. These choices allowed for an efficient SEM mesh undeformed by true Moho topography. Further, instead of homogenization of a possibly biased a priori crustal model, Lekic and Romanowicz jointly inverted for the crustal layer, constrained by surface wave group velocity dispersion maps for T≥ 25 s. We are currently developing a radially anisotropic Vs model of the whole mantle using SEM, following an approach broadly similar to that employed in SEMum. Extension of this methodology to imaging of lower-mantle structure requires the inclusion of a body wave dataset, and thus shorter-period modeling of the global wavefield (T≥ 32 s.). While this period range dictates finer sampling of our SEM mesh, reduced computational cost is still possible through the crustal homogenization scheme. Here, we first discuss the development of an analogous homogenized crustal model and its validity for both the fundamental and higher mode surface wave and the body wave datasets. We focus on maintaining a simplified Moho topography, thus obviating expensive deformation of the SEM mesh, while accurately treating valuable surface-reflected body wave phases (ex: multiple ScS). Second, we discuss implications of treating the crust in this manner for the overall inversion methodology. In particular, we intend to

  10. Fast and Accurate Prediction of Numerical Relativity Waveforms from Binary Black Hole Coalescences Using Surrogate Models

    Science.gov (United States)

    Blackman, Jonathan; Field, Scott E.; Galley, Chad R.; Szilágyi, Béla; Scheel, Mark A.; Tiglio, Manuel; Hemberger, Daniel A.

    2015-09-01

    Simulating a binary black hole coalescence by solving Einstein's equations is computationally expensive, requiring days to months of supercomputing time. Using reduced order modeling techniques, we construct an accurate surrogate model, which is evaluated in a millisecond to a second, for numerical relativity (NR) waveforms from nonspinning binary black hole coalescences with mass ratios in [1, 10] and durations corresponding to about 15 orbits before merger. We assess the model's uncertainty and show that our modeling strategy predicts NR waveforms not used for the surrogate's training with errors nearly as small as the numerical error of the NR code. Our model includes all spherical-harmonic -2Yℓm waveform modes resolved by the NR code up to ℓ=8 . We compare our surrogate model to effective one body waveforms from 50 M⊙ to 300 M⊙ for advanced LIGO detectors and find that the surrogate is always more faithful (by at least an order of magnitude in most cases).

  11. TNO-ADVANCE: a modular powertrain simulation and design tool

    NARCIS (Netherlands)

    Venne, J.W.C. van de; Smokers, R.T.M.

    2000-01-01

    To support its activities in the field of conventional and hybrid vehicles, TNO has developed ADVANCE, a modular simulation tool for the design and evaluation of advanced powertrains. In this paper the various features and the potential of ADVANCE are described and illustrated by means of three case

  12. Advanced TCAD Simulations and Characterization of Semiconductor Devices

    OpenAIRE

    Ewert, Tony

    2006-01-01

    Today, micro- and nano-electronic devices are becoming more complex and advanced as the dimensions are shrinking. It is therefore a very challenging task to develop new device technologies with performance that can be predicted. This thesis focuses on advanced measurement techniques and TCAD simulations in order to characterize and understand the device physics of advanced semiconductor devices. TCAD simulations were made on a novel MOSFET device with asymmetric source and drain structures. ...

  13. Precision Casting via Advanced Simulation and Manufacturing

    Science.gov (United States)

    1997-01-01

    A two-year program was conducted to develop and commercially implement selected casting manufacturing technologies to enable significant reductions in the costs of castings, increase the complexity and dimensional accuracy of castings, and reduce the development times for delivery of high quality castings. The industry-led R&D project was cost shared with NASA's Aerospace Industry Technology Program (AITP). The Rocketdyne Division of Boeing North American, Inc. served as the team lead with participation from Lockheed Martin, Ford Motor Company, Howmet Corporation, PCC Airfoils, General Electric, UES, Inc., University of Alabama, Auburn University, Robinson, Inc., Aracor, and NASA-LeRC. The technical effort was organized into four distinct tasks. The accomplishments reported herein. Task 1.0 developed advanced simulation technology for core molding. Ford headed up this task. On this program, a specialized core machine was designed and built. Task 2.0 focused on intelligent process control for precision core molding. Howmet led this effort. The primary focus of these experimental efforts was to characterize the process parameters that have a strong impact on dimensional control issues of injection molded cores during their fabrication. Task 3.0 developed and applied rapid prototyping to produce near net shape castings. Rocketdyne was responsible for this task. CAD files were generated using reverse engineering, rapid prototype patterns were fabricated using SLS and SLA, and castings produced and evaluated. Task 4.0 was aimed at developing technology transfer. Rocketdyne coordinated this task. Casting related technology, explored and evaluated in the first three tasks of this program, was implemented into manufacturing processes.

  14. Simulation of advanced ultrasound systems using Field II

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    2004-01-01

    impulse responses is explained. A simulation example for a synthetic aperture spread spectrum flow systems is described. It is shown how the advanced coded excitation can be set up, and how the simulation can be parallelized to reduce the simulation time from 17 months to 391 hours using a 32 CPU Linux...

  15. Boolean Process Based Waveform Simulation for Combinational Circuit%基于布尔过程的组合电路波形模拟

    Institute of Scientific and Technical Information of China (English)

    李立健; 闵应骅

    2001-01-01

    High operation frequency and strict timing behavior arecharacteristics of modern high performance integrated circuit, which require that a digital system simulator can precisely simulate not only the logic function but also the timing behavior of a circuit. This paper presents an approach of waveform simulation for combinational circuit based on Boolean process, and introduces its theoretical bases, used techniques, major algorithms, verifications by SPICE and results of experiments.%工作频率高和定时严格是现代集成电路的特点,它们要求数字系统模拟器不但可以模拟电路的逻辑行为,而且可以精确地模拟电路的定时特性.文中提出了一个基于布尔过程的波形模拟途径,并介绍了它的理论基础、主要算法思想、所采用的技术、SPICE验证以及实验结果.

  16. Recent advances in nuclear power plant simulation

    International Nuclear Information System (INIS)

    The field of industrial simulation has experienced very significant progress in recent years, and power plant simulation in particular has been an extremely active area. Improvements may be recorded in practically all simulator subsystems. In Europe, the construction of new full- or optimized-scope nuclear power plant simulators during the middle 1990's has been remarkable intense. In fact, it is possible to identify a distinct simulator generation, which constitutes a new de facto simulation standard. Thomson Training and Simulation has taken part in these developments by designing, building, and validation several of these new simulators for Dutch, German and French nuclear power plants. Their characteristics are discussed in this paper. The following main trends may be identified: Process modeling is clearly evolving towards obtaining engineering-grade performance, even under the added constraints of real-time operation and a very wide range of operating conditions to be covered; Massive use of modern graphic user interfaces (GUI) ensures an unprecedented flexibility and user-friendliness for the Instructor Station; The massive use of GUIs also allows the development of Trainee Stations (TS), which significantly enhance the in-depth training value of the simulators; The development of powerful Software Development Environments (SDE) enables the simulator maintenance teams to keep abreast of modifications carried out in the reference plants; Finally, simulator maintenance and its compliance with simulator fidelity requirements are greatly enhanced by integrated Configuration Management Systems (CMS). In conclusion, the power plant simulation field has attained a strong level of maturity, which benefits its approximately forty years of service to the power generation industry. (author)

  17. Virtual Environments for Advanced Trainers and Simulators

    NARCIS (Netherlands)

    Jense, G.J.; Kuijper, F.

    1993-01-01

    Virtual environment technology is expected to make a big impact on future training and simulation systems. Direct stimulation of human senses (eyesight, auditory, tactile) and new paradigms for user input will improve the realism of simulations and thereby the effectiveness of training systems. Afte

  18. Hybrid and Electric Advanced Vehicle Systems Simulation

    Science.gov (United States)

    Beach, R. F.; Hammond, R. A.; Mcgehee, R. K.

    1985-01-01

    Predefined components connected to represent wide variety of propulsion systems. Hybrid and Electric Advanced Vehicle System (HEAVY) computer program is flexible tool for evaluating performance and cost of electric and hybrid vehicle propulsion systems. Allows designer to quickly, conveniently, and economically predict performance of proposed drive train.

  19. ADVANCE, a modular vehicle simulation environment in MATLAB/SIMULINK

    NARCIS (Netherlands)

    Eelkema, J.; Vink, W.; Tillaart, E. van den

    2002-01-01

    This paper presents the development of a hybrid electric powertrain test platform. In the development process use has been made of ADVANCE, a modular vehicle simulation environment in MATLAB/Simulink. The background, philosophy, and the concept of the ADVANCE tool are discussed and a brief introduct

  20. Advanced Simulation and Computing Business Plan

    Energy Technology Data Exchange (ETDEWEB)

    Rummel, E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-07-09

    To maintain a credible nuclear weapons program, the National Nuclear Security Administration’s (NNSA’s) Office of Defense Programs (DP) needs to make certain that the capabilities, tools, and expert staff are in place and are able to deliver validated assessments. This requires a complete and robust simulation environment backed by an experimental program to test ASC Program models. This ASC Business Plan document encapsulates a complex set of elements, each of which is essential to the success of the simulation component of the Nuclear Security Enterprise. The ASC Business Plan addresses the hiring, mentoring, and retaining of programmatic technical staff responsible for building the simulation tools of the nuclear security complex. The ASC Business Plan describes how the ASC Program engages with industry partners—partners upon whom the ASC Program relies on for today’s and tomorrow’s high performance architectures. Each piece in this chain is essential to assure policymakers, who must make decisions based on the results of simulations, that they are receiving all the actionable information they need.

  1. 2.5D real waveform and real noise simulation of receiver functions in 3D models

    DEFF Research Database (Denmark)

    Schiffer, Christian; Jacobsen, B. H.; Balling, N.

    seismometer is simulated individually through the following steps: A 2D section is extracted from the 3D model along the direction towards the hypocentre. A properly slanted plane or curved impulsive wavefront is propagated through this 2D section, resulting in noise free and spectrally complete synthetic...... seismometer data. The real vertical component signal is taken as a proxy of the real impingent wavefield, so by convolution and subsequent addition of real ambient noise recorded just before the P-arrival we get synthetic vertical and horizontal component data which very closely match the spectral signal...

  2. Microbial Enhanced Oil Recovery - Advanced Reservoir Simulation

    DEFF Research Database (Denmark)

    Nielsen, Sidsel Marie

    to formation of biofilm. The construction of a one-dimensional simulator enables us to investigate how the different mechanisms and the combination of these influence the displacement processes, the saturation profiles and thus the oil recovery curves. The reactive transport model describes...... of the relative permeabilities. Overall, these methods produce similar results. Separate investigations of the surfactant effect have been performed through exemplifying simulation cases, where no biofilm is formed. The water phase saturation profiles are found to contain a waterfront initially...... investigated. A super efficient surfactant produces an incremental recovery recovery around 40 % OOIP over that of waterflooding. Application of the less efficient -- and probably more realistic -- surfactant results in an incremental oil recovery of 9 % OOIP, but it is still considered a significant...

  3. Microbial Enhanced Oil Recovery - Advanced Reservoir Simulation

    OpenAIRE

    Nielsen, Sidsel Marie; Shapiro, Alexander; Stenby, Erling Halfdan; Michelsen, Michael Locht

    2010-01-01

    In this project, a generic model has been set up to include the two main mechanisms in the microbial enhanced oil recovery (MEOR) process; reduction of the interfacial tension (IFT) due to surfactant production, and microscopic fluid diversion as a part of the overall fluid diversion mechanism due to formation of biofilm. The construction of a one-dimensional simulator enables us to investigate how the different mechanisms and the combination of these influence the displacement processes, the...

  4. Advanced numerical techniques in core simulations

    International Nuclear Information System (INIS)

    The whole core simulations are one of the most CPU intensive calculations in reactor physics design and analyses. For a designer it is imperative to perform these calculations with good accuracy and in least time possible to try out various options. It is important for the code developers to use techniques involving minimum approximations and to use most recent numerical methods applied in tandem with huge computing power available today. In the presented paper, some of these methods are discussed. (author)

  5. Advances in NLTE Modeling for Integrated Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Scott, H A; Hansen, S B

    2009-07-08

    The last few years have seen significant progress in constructing the atomic models required for non-local thermodynamic equilibrium (NLTE) simulations. Along with this has come an increased understanding of the requirements for accurately modeling the ionization balance, energy content and radiative properties of different elements for a wide range of densities and temperatures. Much of this progress is the result of a series of workshops dedicated to comparing the results from different codes and computational approaches applied to a series of test problems. The results of these workshops emphasized the importance of atomic model completeness, especially in doubly excited states and autoionization transitions, to calculating ionization balance, and the importance of accurate, detailed atomic data to producing reliable spectra. We describe a simple screened-hydrogenic model that calculates NLTE ionization balance with surprising accuracy, at a low enough computational cost for routine use in radiation-hydrodynamics codes. The model incorporates term splitting, {Delta}n = 0 transitions, and approximate UTA widths for spectral calculations, with results comparable to those of much more detailed codes. Simulations done with this model have been increasingly successful at matching experimental data for laser-driven systems and hohlraums. Accurate and efficient atomic models are just one requirement for integrated NLTE simulations. Coupling the atomic kinetics to hydrodynamics and radiation transport constrains both discretizations and algorithms to retain energy conservation, accuracy and stability. In particular, the strong coupling between radiation and populations can require either very short timesteps or significantly modified radiation transport algorithms to account for NLTE material response. Considerations such as these continue to provide challenges for NLTE simulations.

  6. Georgia Tech Catalog of Gravitational Waveforms

    CERN Document Server

    Jani, Karan; Clark, James A; London, Lionel; Laguna, Pablo; Shoemaker, Deirdre

    2016-01-01

    This paper introduces a catalog of gravitational waveforms from the bank of simulations by the numerical relativity effort at Georgia Tech. Currently, the catalog consists of 452 distinct waveforms from more than 600 binary black hole simulations: 128 of the waveforms are from binaries with black hole spins aligned with the orbital angular momentum, and 324 are from precessing binary black hole systems. The waveforms from binaries with non-spinning black holes have mass-ratios $q = m_1/m_2 \\le 15$, and those with precessing, spinning black holes have $q \\le 8$. The waveforms expand a moderate number of orbits in the late inspiral, the burst during coalescence, and the ring-down of the final black hole. Examples of waveforms in the catalog matched against the widely used approximate models are presented. In addition, predictions of the mass and spin of the final black hole by phenomenological fits are tested against the results from the simulation bank. The role of the catalog in interpreting the GW150914 even...

  7. Process simulation for advanced composites production

    Energy Technology Data Exchange (ETDEWEB)

    Allendorf, M.D.; Ferko, S.M.; Griffiths, S. [Sandia National Labs., Livermore, CA (United States)] [and others

    1997-04-01

    The objective of this project is to improve the efficiency and lower the cost of chemical vapor deposition (CVD) processes used to manufacture advanced ceramics by providing the physical and chemical understanding necessary to optimize and control these processes. Project deliverables include: numerical process models; databases of thermodynamic and kinetic information related to the deposition process; and process sensors and software algorithms that can be used for process control. Target manufacturing techniques include CVD fiber coating technologies (used to deposit interfacial coatings on continuous fiber ceramic preforms), chemical vapor infiltration, thin-film deposition processes used in the glass industry, and coating techniques used to deposit wear-, abrasion-, and corrosion-resistant coatings for use in the pulp and paper, metals processing, and aluminum industries.

  8. Parameter estimation of neutron star-black hole binaries using an advanced gravitational-wave detector network: Effects of the full post-Newtonian waveform

    CERN Document Server

    Tagoshi, Hideyuki; Pai, Archana; Arun, K G

    2014-01-01

    We investigate the effects of using the {\\it full} waveform (FWF) over the conventional {\\it restricted} waveform (RWF) of the inspiral signal from a coalescing compact binary (CCB) system in extracting the parameters of the source, using a global network of second generation interferometric detectors. We study a hypothetical population of (1.4-10)$M_\\odot$ NS-BH binaries (uniformly distributed and oriented in the sky) by employing the full post-Newtonian waveforms, which not only include contributions from various harmonics other than the dominant one (quadrupolar mode) but also the post-Newtonian amplitude corrections associated with each harmonic, of the inspiral signal expected from this system. It is expected that the GW detector network consisting of the two LIGO detectors and a Virgo detector will be joined by KAGRA and by proposed LIGO-India. We study the problem of parameter estimation with all 16 possible detector configurations. Comparing medians of error distributions obtained using FWFs with thos...

  9. Arrival angle anomalies of Rayleigh waves observed at a broadband array: a systematic study based on earthquake data, full waveform simulations and noise correlations

    Science.gov (United States)

    Pedersen, H. A.; Boué, P.; Poli, P.; Colombi, A.

    2015-12-01

    Deviation of seismic surface waves from the great-circle between source and receiver is illustrated by the anomalies in the arrival angle, that is the difference between the observed backazimuth of the incident waves and the great-circle. Such arrival angle anomalies have been known for decades, but observations remain scattered. We present a systematic study of arrival angle anomalies of fundamental mode Rayleigh waves (20-100 s period interval) from 289 earthquakes and recorded by a broadband network LAPNET, located in northern Finland. These observations are compared with those of full waveform synthetic seismograms for the same events, calculated in a 3-D Earth and also compared with those of seismograms obtained by ambient noise correlation. The arrival angle anomalies for individual events are complex, and have significant variations with period. On average, the mean absolute deviation decreases from ˜9° at 20 s period to ˜3° at 100 s period. The synthetic seismograms show the same evolution, albeit with somewhat smaller deviations. While the arrival angle anomalies are fairly well simulated at long periods, the deviations at short periods are very poorly modelled, demonstrating the importance of the continuous improvement of global crustal models. At 20-30 s period, both event data and numerical simulations have strong multipathing, and relative amplitude changes between different waves will induced differences in deviations between very closely located events. The source mechanism has only limited influence on the deviations, demonstrating that they are directly linked to propagation effects, including near-field effects in the source area. This observation is confirmed by the comparison with seismic noise correlation records, that is where the surface waves correspond to those emitted by a point source at the surface, as the two types of observations are remarkably similar in the cases where earthquakes are located close to seismic stations. This

  10. Interoperable Technologies for Advanced Petascale Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiaolin [SUNY at Stony Brook

    2013-01-14

    Our final report on the accomplishments of ITAPS at Stony Brook during period covered by the research award includes component service, interface service and applications. On the component service, we have designed and implemented a robust functionality for the Lagrangian tracking of dynamic interface. We have migrated the hyperbolic, parabolic and elliptic solver from stage-wise second order toward global second order schemes. We have implemented high order coupling between interface propagation and interior PDE solvers. On the interface service, we have constructed the FronTier application programer's interface (API) and its manual page using doxygen. We installed the FronTier functional interface to conform with the ITAPS specifications, especially the iMesh and iMeshP interfaces. On applications, we have implemented deposition and dissolution models with flow and implemented the two-reactant model for a more realistic precipitation at the pore level and its coupling with Darcy level model. We have continued our support to the study of fluid mixing problem for problems in inertial comfinement fusion. We have continued our support to the MHD model and its application to plasma liner implosion in fusion confinement. We have simulated a step in the reprocessing and separation of spent fuels from nuclear power plant fuel rods. We have implemented the fluid-structure interaction for 3D windmill and parachute simulations. We have continued our collaboration with PNNL, BNL, LANL, ORNL, and other SciDAC institutions.

  11. Sparse Frequency Waveform Design for Radar-Embedded Communication

    Directory of Open Access Journals (Sweden)

    Chaoyun Mai

    2016-01-01

    Full Text Available According to the Tag application with function of covert communication, a method for sparse frequency waveform design based on radar-embedded communication is proposed. Firstly, sparse frequency waveforms are designed based on power spectral density fitting and quasi-Newton method. Secondly, the eigenvalue decomposition of the sparse frequency waveform sequence is used to get the dominant space. Finally the communication waveforms are designed through the projection of orthogonal pseudorandom vectors in the vertical subspace. Compared with the linear frequency modulation waveform, the sparse frequency waveform can further improve the bandwidth occupation of communication signals, thus achieving higher communication rate. A certain correlation exists between the reciprocally orthogonal communication signals samples and the sparse frequency waveform, which guarantees the low SER (signal error rate and LPI (low probability of intercept. The simulation results verify the effectiveness of this method.

  12. Altimeter waveform software design

    Science.gov (United States)

    Hayne, G. S.; Miller, L. S.; Brown, G. S.

    1977-01-01

    Techniques are described for preprocessing raw return waveform data from the GEOS-3 radar altimeter. Topics discussed include: (1) general altimeter data preprocessing to be done at the GEOS-3 Data Processing Center to correct altimeter waveform data for temperature calibrations, to convert between engineering and final data units and to convert telemetered parameter quantities to more appropriate final data distribution values: (2) time "tagging" of altimeter return waveform data quantities to compensate for various delays, misalignments and calculational intervals; (3) data processing procedures for use in estimating spacecraft attitude from altimeter waveform sampling gates; and (4) feasibility of use of a ground-based reflector or transponder to obtain in-flight calibration information on GEOS-3 altimeter performance.

  13. The use of advanced computer simulation in structural design

    Energy Technology Data Exchange (ETDEWEB)

    Field, C.J.; Mole, A. [Arup, San Fransisco, CA (United States); Arkinstall, M. [Arup, Sydney (Australia)

    2005-07-01

    The benefits that can be gained from the application of advanced numerical simulation in building design were discussed. A review of current practices in structural engineering was presented along with an illustration of a range of international project case studies. Structural engineers use analytical methods to evaluate both static and dynamic loads. Structural design is prescribed by a range of building codes, depending on location, building type and loading, but often, buildings do not fit well within the codes, particularly if one wants to take advantage of new technologies and developments in design that are not covered by the code. Advanced simulation refers to the use of mathematical modeling to complex problems to allow a wider consideration of building types and conditions that can be designed reliably using standard practices. Advanced simulation is used to address virtual testing and prototyping, verifying innovative design ideas, forensic engineering, and design optimization. The benefits of advanced simulation include enhanced creativity, improved performance, cost savings, risk management, sustainable design solutions, and better communication. The following 5 case studies illustrated the value gained by using advanced simulation as an integral part of the design process: the earthquake resistant Maison Hermes in Tokyo; the seismic resistant braces known as the Unbonded Brace for use in the United States; a simulation of the existing Disney Museum to evaluate its capacity to resist earthquakes; simulation of the MIT Brain and Cognitive Science Project to evaluate the effect of different foundation types on the vibration entering the building; and, the Beijing Aquatic Center whose design was streamlined by optimized structural analysis. It was suggested that industry should encourage the transfer of technology from other professions and should try to collaborate towards a global building model to construct buildings in a more efficient manner. 7 refs

  14. DSP Based Waveform Generator

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The DSP Based Waveform Generator is used for CSR Control system to control special controlled objects, such as the pulsed power supply for magnets, RF system, injection and extraction synchronization, global CSR synchronization etc. This intelligent controller based on 4800 MIPS DSP and 256M SDRAM technology will supply highly stable and highly accurate reference waveform used by the power supply of magnets. The specifications are as follows:

  15. Equipping simulators with an advanced thermal hydraulics model EDF's experience

    International Nuclear Information System (INIS)

    The development of an accelerated version of the advanced CATHARe-1 thermal hydraulics code designed for EDF training simulators (CATHARE-SIMU) was successfully completed as early as 1991. Its successful integration as the principal model of the SIPA Post-Accident Simulator meant that its use could be extended to full-scale simulators as part of the renovation of the stock of existing simulators. In order to further extend the field of application to accidents occurring in shutdown states requiring action and to catch up with developments in respect of the CATHARE code, EDF initiated the SCAR Project designed to adapt CATHARE-2 to simulator requirements (acceleration, parallelization of the computation and extension of the simulation range). In other respects, the installation of SIPA on workstations means that the authors can envisage the application of this remarkable training facility to the understanding of thermal hydraulics accident phenomena

  16. Safety Assessment of Advanced Imaging Sequences II: Simulations

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    2016-01-01

    . The simulation time is between 0.67 ms to 2.8 ms per emission and imaging point, making it possible to simulate even complex emission sequences in less than 1 s for a single spatial position. The linear simulations yield a relative accuracy on MI between -12.1% to 52.3% and for Ispta.3 between -38......An automatic approach for simulating the emitted pressure, intensity, and MI of advanced ultrasound imaging sequences is presented. It is based on a linear simulation of pressure fields using Field II, and it is hypothesized that linear simulation can attain the needed accuracy for predicting...... Mechanical Index (MI) and Ispta.3 as required by FDA. The method is performed on four different imaging schemes and compared to measurements conducted using the SARUS experimental scanner. The sequences include focused emissions with an F-number of 2 with 64 elements that generate highly non-linear fields...

  17. Seismic waveform modeling over cloud

    Science.gov (United States)

    Luo, Cong; Friederich, Wolfgang

    2016-04-01

    With the fast growing computational technologies, numerical simulation of seismic wave propagation achieved huge successes. Obtaining the synthetic waveforms through numerical simulation receives an increasing amount of attention from seismologists. However, computational seismology is a data-intensive research field, and the numerical packages usually come with a steep learning curve. Users are expected to master considerable amount of computer knowledge and data processing skills. Training users to use the numerical packages, correctly access and utilize the computational resources is a troubled task. In addition to that, accessing to HPC is also a common difficulty for many users. To solve these problems, a cloud based solution dedicated on shallow seismic waveform modeling has been developed with the state-of-the-art web technologies. It is a web platform integrating both software and hardware with multilayer architecture: a well designed SQL database serves as the data layer, HPC and dedicated pipeline for it is the business layer. Through this platform, users will no longer need to compile and manipulate various packages on the local machine within local network to perform a simulation. By providing users professional access to the computational code through its interfaces and delivering our computational resources to the users over cloud, users can customize the simulation at expert-level, submit and run the job through it.

  18. Free-boundary simulations of ITER advanced scenarios

    International Nuclear Information System (INIS)

    The successful operation of ITER advanced scenarios is likely to be a major step forward in the development of controlled fusion as a power production source. ITER advanced scenarios raise specific challenges that are not encountered in presently-operated tokamaks. In this thesis, it is argued that ITER advanced operation may benefit from optimal control techniques. Optimal control ensures high performance operation while guaranteeing tokamak integrity. The application of optimal control techniques for ITER operation is assessed and it is concluded that robust optimisation is appropriate for ITER operation of advanced scenarios. Real-time optimisation schemes are discussed and it is concluded that the necessary conditions of optimality tracking approach may potentially be appropriate for ITER operation, thus offering a viable closed-loop optimal control approach. Simulations of ITER advanced operation are necessary in order to assess the present ITER design and uncover the main difficulties that may be encountered during advanced operation. The DINA-CH and CRONOS full tokamak simulator is used to simulate the operation of the ITER hybrid and steady-state scenarios. It is concluded that the present ITER design is appropriate for performing a hybrid scenario pulse lasting more than 1000 sec, with a flat-top plasma current of 12 MA, and a fusion gain of Q ≅ 8. Similarly, a steady-state scenario without internal transport barrier, with a flat-top plasma current of 10 MA, and with a fusion gain of Q ≅ 5 can be realised using the present ITER design. The sensitivity of the advanced scenarios with respect to transport models and physical assumption is assessed using CRONOS. It is concluded that the hybrid scenario and the steady-state scenario are highly sensitive to the L-H transition timing, to the value of the confinement enhancement factor, to the heating and current drive scenario during ramp-up, and, to a lesser extent, to the density peaking and pedestal

  19. Simulating advanced life support systems to test integrated control approaches

    Science.gov (United States)

    Kortenkamp, D.; Bell, S.

    Simulations allow for testing of life support control approaches before hardware is designed and built. Simulations also allow for the safe exploration of alternative control strategies during life support operation. As such, they are an important component of any life support research program and testbed. This paper describes a specific advanced life support simulation being created at NASA Johnson Space Center. It is a discrete-event simulation that is dynamic and stochastic. It simulates all major components of an advanced life support system, including crew (with variable ages, weights and genders), biomass production (with scalable plantings of ten different crops), water recovery, air revitalization, food processing, solid waste recycling and energy production. Each component is modeled as a producer of certain resources and a consumer of certain resources. The control system must monitor (via sensors) and control (via actuators) the flow of resources throughout the system to provide life support functionality. The simulation is written in an object-oriented paradigm that makes it portable, extensible and reconfigurable.

  20. Patient Simulation Software to Augment an Advanced Pharmaceutics Course

    Science.gov (United States)

    Schonder, Kristine

    2011-01-01

    Objective To implement and assess the effectiveness of adding a pharmaceutical care simulation program to an advanced therapeutics course. Design PharmaCAL (University of Pittsburgh), a software program that uses a branched-outcome decision making model, was used to create patient simulations to augment lectures given in the course. In each simulation, students were presented with a challenge, given choices, and then provided with consequences specific to their choices. Assessments A survey was administered at the end of the course and students indicated the simulations were enjoyable (92%), easy to use (90%), stimulated interest in critically ill patients (82%), and allowed for application of lecture material (91%). A 5-item presimulation and postsimulation test on the anemia simulation was administered to assess learning. Students answered significantly more questions correctly on the postsimulation test than on the presimulation test (p < 0.001). Seventy-eight percent of students answered the same 5 questions correctly on the final examination. Conclusion Patient simulation software that used a branched-outcome decision model was an effective supplement to class lectures in an advanced pharmaceutics course and was well-received by pharmacy students. PMID:21519411

  1. Lessons Learned From Dynamic Simulations of Advanced Fuel Cycles

    Energy Technology Data Exchange (ETDEWEB)

    Steven J. Piet; Brent W. Dixon; Jacob J. Jacobson; Gretchen E. Matthern; David E. Shropshire

    2009-04-01

    Years of performing dynamic simulations of advanced nuclear fuel cycle options provide insights into how they could work and how one might transition from the current once-through fuel cycle. This paper summarizes those insights from the context of the 2005 objectives and goals of the Advanced Fuel Cycle Initiative (AFCI). Our intent is not to compare options, assess options versus those objectives and goals, nor recommend changes to those objectives and goals. Rather, we organize what we have learned from dynamic simulations in the context of the AFCI objectives for waste management, proliferation resistance, uranium utilization, and economics. Thus, we do not merely describe “lessons learned” from dynamic simulations but attempt to answer the “so what” question by using this context. The analyses have been performed using the Verifiable Fuel Cycle Simulation of Nuclear Fuel Cycle Dynamics (VISION). We observe that the 2005 objectives and goals do not address many of the inherently dynamic discriminators among advanced fuel cycle options and transitions thereof.

  2. Integration of Advanced Simulation and Visualization for Manufacturing Process Optimization

    Science.gov (United States)

    Zhou, Chenn; Wang, Jichao; Tang, Guangwu; Moreland, John; Fu, Dong; Wu, Bin

    2016-05-01

    The integration of simulation and visualization can provide a cost-effective tool for process optimization, design, scale-up and troubleshooting. The Center for Innovation through Visualization and Simulation (CIVS) at Purdue University Northwest has developed methodologies for such integration with applications in various manufacturing processes. The methodologies have proven to be useful for virtual design and virtual training to provide solutions addressing issues on energy, environment, productivity, safety, and quality in steel and other industries. In collaboration with its industrial partnerships, CIVS has provided solutions to companies, saving over US38 million. CIVS is currently working with the steel industry to establish an industry-led Steel Manufacturing Simulation and Visualization Consortium through the support of National Institute of Standards and Technology AMTech Planning Grant. The consortium focuses on supporting development and implementation of simulation and visualization technologies to advance steel manufacturing across the value chain.

  3. Advanced Simulation and Computing FY17 Implementation Plan, Version 0

    Energy Technology Data Exchange (ETDEWEB)

    McCoy, Michel [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Archer, Bill [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hendrickson, Bruce [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wade, Doug [National Nuclear Security Administration (NNSA), Washington, DC (United States). Office of Advanced Simulation and Computing and Institutional Research and Development; Hoang, Thuc [National Nuclear Security Administration (NNSA), Washington, DC (United States). Computational Systems and Software Environment

    2016-08-29

    The Stockpile Stewardship Program (SSP) is an integrated technical program for maintaining the safety, surety, and reliability of the U.S. nuclear stockpile. The SSP uses nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of experimental facilities and programs, and the computational capabilities to support these programs. The Advanced Simulation and Computing Program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources that support annual stockpile assessment and certification, study advanced nuclear weapons design and manufacturing processes, analyze accident scenarios and weapons aging, and provide the tools to enable stockpile Life Extension Programs (LEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balance of resource, including technical staff, hardware, simulation software, and computer science solutions. ASC is now focused on increasing predictive capabilities in a three-dimensional (3D) simulation environment while maintaining support to the SSP. The program continues to improve its unique tools for solving progressively more difficult stockpile problems (sufficient resolution, dimensionality, and scientific details), and quantifying critical margins and uncertainties. Resolving each issue requires increasingly difficult analyses because the aging process has progressively moved the stockpile further away from the original test base. Where possible, the program also enables the use of high performance computing (HPC) and simulation tools to address broader national security needs, such as foreign nuclear weapon assessments and counter nuclear terrorism.

  4. Requirements for advanced simulation of nuclear reactor and chemicalseparation plants.

    Energy Technology Data Exchange (ETDEWEB)

    Palmiotti, G.; Cahalan, J.; Pfeiffer, P.; Sofu, T.; Taiwo, T.; Wei,T.; Yacout, A.; Yang, W.; Siegel, A.; Insepov, Z.; Anitescu, M.; Hovland,P.; Pereira, C.; Regalbuto, M.; Copple, J.; Willamson, M.

    2006-12-11

    This report presents requirements for advanced simulation of nuclear reactor and chemical processing plants that are of interest to the Global Nuclear Energy Partnership (GNEP) initiative. Justification for advanced simulation and some examples of grand challenges that will benefit from it are provided. An integrated software tool that has its main components, whenever possible based on first principles, is proposed as possible future approach for dealing with the complex problems linked to the simulation of nuclear reactor and chemical processing plants. The main benefits that are associated with a better integrated simulation have been identified as: a reduction of design margins, a decrease of the number of experiments in support of the design process, a shortening of the developmental design cycle, and a better understanding of the physical phenomena and the related underlying fundamental processes. For each component of the proposed integrated software tool, background information, functional requirements, current tools and approach, and proposed future approaches have been provided. Whenever possible, current uncertainties have been quoted and existing limitations have been presented. Desired target accuracies with associated benefits to the different aspects of the nuclear reactor and chemical processing plants were also given. In many cases the possible gains associated with a better simulation have been identified, quantified, and translated into economical benefits.

  5. Hybrid and electric advanced vehicle systems (heavy) simulation

    Science.gov (United States)

    Hammond, R. A.; Mcgehee, R. K.

    1981-01-01

    A computer program to simulate hybrid and electric advanced vehicle systems (HEAVY) is described. It is intended for use early in the design process: concept evaluation, alternative comparison, preliminary design, control and management strategy development, component sizing, and sensitivity studies. It allows the designer to quickly, conveniently, and economically predict the performance of a proposed drive train. The user defines the system to be simulated using a library of predefined component models that may be connected to represent a wide variety of propulsion systems. The development of three models are discussed as examples.

  6. Advances in Simulation of Wave Interaction with Extended MHD Phenomena

    International Nuclear Information System (INIS)

    The Integrated Plasma Simulator (IPS) provides a framework within which some of the most advanced, massively-parallel fusion modeling codes can be interoperated to provide a detailed picture of the multi-physics processes involved in fusion experiments. The presentation will cover four topics: (1) recent improvements to the IPS, (2) application of the IPS for very high resolution simulations of ITER scenarios, (3) studies of resistive and ideal MHD stability in tokamk discharges using IPS facilities, and (4) the application of RF power in the electron cyclotron range of frequencies to control slowly growing MHD modes in tokamaks and initial evaluations of optimized location for RF power deposition.

  7. Advanced simulation of windmills in electric power supply

    DEFF Research Database (Denmark)

    Akhmatov, Vladislav; Knudsen, Hans; Nielsen, Arne Hejde

    2000-01-01

    An advanced model of a grid-connected windmill is set up where the windmill is a complex electro-mechanical system. The windmill model is implemented as a standardised component in the dynamic simulation tool, PSS/E, which makes it possible to investigate dynamic behaviour of grid-connected windm......An advanced model of a grid-connected windmill is set up where the windmill is a complex electro-mechanical system. The windmill model is implemented as a standardised component in the dynamic simulation tool, PSS/E, which makes it possible to investigate dynamic behaviour of grid......-connected windmills as a part of realistic electrical grid models. That means an arbitrary number of wind farms or single windmills within an arbitrary network configuration. The windmill model may be applied to study of electric power system stability and of power quality as well. It is found that a grid...

  8. Advanced 3D Photocathode Modeling and Simulations Final Report

    International Nuclear Information System (INIS)

    High brightness electron beams required by the proposed Next Linear Collider demand strong advances in photocathode electron gun performance. Significant improvement in the production of such beams with rf photocathode electron guns is hampered by the lack high-fidelity simulations. The critical missing piece in existing gun codes is a physics-based, detailed treatment of the very complex and highly nonlinear photoemission process

  9. Managing Full waveform LiDAR data: a challenging task for the forthcoming years

    OpenAIRE

    Bretar, Frederic; Chauve, Adrien; Mallet, Clément; Jutzi, B.

    2008-01-01

    This paper proposes to summarize researches and new advances in full waveform lidar data. After a description of full waveform lidar systems, we will review different methodologies developed to process the waveforms (modelling, correlation, stacking). Applications on urban and vegetated areas are then presented. The paper ends up with recommendations on future research themes.

  10. The Consortium for Advanced Simulation of Light Water Reactors

    International Nuclear Information System (INIS)

    The Consortium for Advanced Simulation of Light Water Reactors (CASL) is a DOE Energy Innovation Hub for modeling and simulation of nuclear reactors. It brings together an exceptionally capable team from national labs, industry and academia that will apply existing modeling and simulation capabilities and develop advanced capabilities to create a usable environment for predictive simulation of light water reactors (LWRs). This environment, designated as the Virtual Environment for Reactor Applications (VERA), will incorporate science-based models, state-of-the-art numerical methods, modern computational science and engineering practices, and uncertainty quantification (UQ) and validation against data from operating pressurized water reactors (PWRs). It will couple state-of-the-art fuel performance, neutronics, thermal-hydraulics (T-H), and structural models with existing tools for systems and safety analysis and will be designed for implementation on both today's leadership-class computers and the advanced architecture platforms now under development by the DOE. CASL focuses on a set of challenge problems such as CRUD induced power shift and localized corrosion, grid-to-rod fretting fuel failures, pellet clad interaction, fuel assembly distortion, etc. that encompass the key phenomena limiting the performance of PWRs. It is expected that much of the capability developed will be applicable to other types of reactors. CASL's mission is to develop and apply modeling and simulation capabilities to address three critical areas of performance for nuclear power plants: (1) reduce capital and operating costs per unit energy by enabling power uprates and plant lifetime extension, (2) reduce nuclear waste volume generated by enabling higher fuel burnup, and (3) enhance nuclear safety by enabling high-fidelity predictive capability for component performance.

  11. The Consortium for Advanced Simulation of Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ronaldo Szilard; Hongbin Zhang; Doug Kothe; Paul Turinsky

    2011-10-01

    The Consortium for Advanced Simulation of Light Water Reactors (CASL) is a DOE Energy Innovation Hub for modeling and simulation of nuclear reactors. It brings together an exceptionally capable team from national labs, industry and academia that will apply existing modeling and simulation capabilities and develop advanced capabilities to create a usable environment for predictive simulation of light water reactors (LWRs). This environment, designated as the Virtual Environment for Reactor Applications (VERA), will incorporate science-based models, state-of-the-art numerical methods, modern computational science and engineering practices, and uncertainty quantification (UQ) and validation against data from operating pressurized water reactors (PWRs). It will couple state-of-the-art fuel performance, neutronics, thermal-hydraulics (T-H), and structural models with existing tools for systems and safety analysis and will be designed for implementation on both today's leadership-class computers and the advanced architecture platforms now under development by the DOE. CASL focuses on a set of challenge problems such as CRUD induced power shift and localized corrosion, grid-to-rod fretting fuel failures, pellet clad interaction, fuel assembly distortion, etc. that encompass the key phenomena limiting the performance of PWRs. It is expected that much of the capability developed will be applicable to other types of reactors. CASL's mission is to develop and apply modeling and simulation capabilities to address three critical areas of performance for nuclear power plants: (1) reduce capital and operating costs per unit energy by enabling power uprates and plant lifetime extension, (2) reduce nuclear waste volume generated by enabling higher fuel burnup, and (3) enhance nuclear safety by enabling high-fidelity predictive capability for component performance.

  12. Advanced studies on Simulation Methodologies for very Complicated Fracture Phenomena

    International Nuclear Information System (INIS)

    Although nowadays, computational techniques are well developed, for Extremely Complicated Fracture Phenomena, they are still very difficult to simulate, for general engineers, researchers. To overcome many difficulties in those simulations, we have developed not only Simulation Methodologies but also theoretical basis and concepts. We sometimes observe extremely complicated fracture patterns, especially in dynamic fracture phenomena such as dynamic crack branching, kinking, curving, etc. For examples, although the humankind, from primitive men to modern scientists such as Albert Einstein had watched the post-mortem patterns of dynamic crack branching, the governing condition for the onset of the phenomena had been unsolved until our experimental study. From in these studies, we found the governing condition of dynamic crack bifurcation, as follows. When the total energy flux per unit time into a propagating crack tip reaches the material crack resistance, the crack braches into two cracks [total energy flux criterion]. The crack branches many times whenever the criterion is satisfied. Furthermore, the complexities also arise due to their time-dependence and/or their-deformation dependence. In order to make it possible to simulate such extremely complicated fracture phenomena, we developed many original advanced computational methods and technologies. These are (i) moving finite element method based on Delaunay automatic triangulation (MFEMBOAT), path independent, (ii) equivalent domain integral expression of the dynamic J integral associated with a continuous auxiliary function, (iii) Mixed phase path-prediction mode simulation, (iv) implicit path prediction criterion. In this paper, these advanced computational methods are thoroughly explained together with successful comparison with the experimental results. Since multiple dynamic crack branching phenomena may be most complicated fracture due to complicated fracture paths, and its time dependence (transient

  13. Advance simulation capability for environmental management (ASCEM) - 59065

    International Nuclear Information System (INIS)

    The United States Department Energy (DOE) Office of Environmental Management (EM) determined that uniform application of advanced modeling in the subsurface could help reduce the cost and risks associated with its environmental cleanup mission. In response to this determination, the EM Office of Technology Innovation and Development (OTID), Groundwater and Soil Remediation (GW and S) began the program Advanced Simulation Capability for Environmental Management (ASCEM). ASCEM is a state-of-the-art scientific tool and approach for integrating data and scientific understanding to enable prediction of contaminant fate and transport in natural and engineered systems. This initiative supports the reduction of uncertainties and risks associated with EM?s environmental cleanup and closure programs through better understanding and quantifying the subsurface flow and contaminant transport behavior in complex geological systems. This involves the long-term performance of engineered components, including cementitious materials in nuclear waste disposal facilities that may be sources for future contamination of the subsurface. This paper describes the ASCEM tools and approach and the ASCEM programmatic accomplishments completed in 2010 including recent advances and technology transfer. The US Department of Energy Office of Environmental Management has begun development of an Advanced Simulation Capability for Environmental Management, (ASCEM). This program will provide predictions of the end states of contaminated areas allowing for cost and risk reduction of EM remedial activities. ASCEM will provide the tools and approaches necessary to standardize risk and performance assessments across the DOE complex. Through its Phase One demonstration, the ASCEM team has shown value to the EM community in the areas of High Performance Computing, Data Management, Visualization, and Uncertainty Quantification. In 2012, ASCEM will provide an initial limited release of a community code for

  14. Simulated herbivory advances autumn phenology in Acer rubrum

    Science.gov (United States)

    Forkner, Rebecca E.

    2014-05-01

    To determine the degree to which herbivory contributes to phenotypic variation in autumn phenology for deciduous trees, red maple ( Acer rubrum) branches were subjected to low and high levels of simulated herbivory and surveyed at the end of the season to assess abscission and degree of autumn coloration. Overall, branches with simulated herbivory abscised ˜7 % more leaves at each autumn survey date than did control branches within trees. While branches subjected to high levels of damage showed advanced phenology, abscission rates did not differ from those of undamaged branches within trees because heavy damage induced earlier leaf loss on adjacent branch nodes in this treatment. Damaged branches had greater proportions of leaf area colored than undamaged branches within trees, having twice the amount of leaf area colored at the onset of autumn and having ˜16 % greater leaf area colored in late October when nearly all leaves were colored. When senescence was scored as the percent of all leaves abscised and/or colored, branches in both treatments reached peak senescence earlier than did control branches within trees: dates of 50 % senescence occurred 2.5 days earlier for low herbivory branches and 9.7 days earlier for branches with high levels of simulated damage. These advanced rates are of the same time length as reported delays in autumn senescence and advances in spring onset due to climate warming. Thus, results suggest that should insect damage increase as a consequence of climate change, it may offset a lengthening of leaf life spans in some tree species.

  15. Advances in numerical simulation of nonlinear water waves

    CERN Document Server

    Ma, Qingwei

    2014-01-01

    Most of the Earth's surface is covered by water. Our everyday lives and activities are affected by water waves in oceans, such as the tsunami that occurred in the Indian Ocean on 26 December 2004. This indicates how important it is for us to fully understand water waves, in particular the very large ones. One way to do so is to perform numerical simulation based on the nonlinear theory. Considerable research advances have been made in this area over the past decade by developing various numerical methods and applying them to emerging problems; however, until now there has been no comprehensive

  16. New Developments in the Simulation of Advanced Accelerator Concepts

    International Nuclear Information System (INIS)

    Improved computational methods are essential to the diverse and rapidly developing field of advanced accelerator concepts. We present an overview of some computational algorithms for laser-plasma concepts and high-brightness photocathode electron sources. In particular, we discuss algorithms for reduced laser-plasma models that can be orders of magnitude faster than their higher-fidelity counterparts, as well as important on-going efforts to include relevant additional physics that has been previously neglected. As an example of the former, we present 2D laser wakefield accelerator simulations in an optimal Lorentz frame, demonstrating and gt;10 GeV energy gain of externally injected electrons over a 2 m interaction length, showing good agreement with predictions from scaled simulations and theory, with a speedup factor of ∼2,000 as compared to standard particle-in-cell.

  17. Advanced Simulations of Optical Transition and Diffraction Radiation

    CERN Document Server

    AUTHOR|(CDS)2078350; Bobb, Lorraine Marie; Bolzon, B; Bravin, Enrico; Karataev, Pavel; Kruchinin, Konstantin; Lefevre, Thibaut; Mazzoni, Stefano

    2015-01-01

    Charged particle beam diagnostics is a key task in modern and future accelerator installations. The diagnostic tools are practically the “eyes” of the operators. The precision and resolution of the diagnostic equipment are crucial to define the performance of the accelerator. Transition and diffraction radiation (TR and DR) are widely used for electron beam parameter monitoring. However, the precision and resolution of those devices are determined by how well the production, transport and detection of these radiation types are understood. This paper reports on simulations of TR and DR spatial-spectral characteristics using the physical optics propagation (POP) mode of the Zemax advanced optics simulation software. A good consistency with theory is demonstrated. Also, realistic optical system alignment issues are discussed.

  18. Hybridizing Gravitationl Waveforms of Inspiralling Binary Neutron Star Systems

    Science.gov (United States)

    Cullen, Torrey; LIGO Collaboration

    2016-03-01

    Gravitational waves are ripples in space and time and were predicted to be produced by astrophysical systems such as binary neutron stars by Albert Einstein. These are key targets for Laser Interferometer and Gravitational Wave Observatory (LIGO), which uses template waveforms to find weak signals. The simplified template models are known to break down at high frequency, so I wrote code that constructs hybrid waveforms from numerical simulations to accurately cover a large range of frequencies. These hybrid waveforms use Post Newtonian template models at low frequencies and numerical data from simulations at high frequencies. They are constructed by reading in existing Post Newtonian models with the same masses as simulated stars, reading in the numerical data from simulations, and finding the ideal frequency and alignment to ``stitch'' these waveforms together.

  19. Advanced electrical simulation of thin film solar cells

    International Nuclear Information System (INIS)

    Advanced electrical simulation of copper indium gallium diselenide solar cells is illustrated by setting up a demonstration case in SCAPS (Solar Cell Capacitance Simulator), the solar cell simulation programme of the University of Gent. The model includes band gap grading, multivalent defects and metastable transitions between defects. This simplified demonstration model clearly and quantitatively illustrates some topics that were extensively discussed in recent literature: metastable defects exist in either an acceptor or in a donor configuration; the occupation of these configurations is set during initial conditions at higher temperature, and then frozen in during cell operation at lower temperature. These occupations can strongly influence the effective doping profile in the absorber, and hence possible energy barriers in the structure. The dependence of such barriers on the initial conditions and on the operating voltage can cause a considerable dependence of the current–voltage characteristics on the initial conditions, especially of the fill factor. At the same time, the demonstration model illustrates some of the recent extensions of SCAPS. - Highlights: ► SCAPS, the Solar Cell Capacitance Simulator of UGent is freely available. ► SCAPS is keeping up with the sophistication of state-of-the-art solar cells. ► It can now handle: multivalent and metastable defects; grading of all properties. ► It is shown how metastable defects can lead to metastable cell characteristics. ► A relation conduction band barrier-fill factor is numerically established

  20. Conjugate heat transfer simulations of advanced research reactor fuel

    International Nuclear Information System (INIS)

    Highlights: • Temperature predictions are enhanced by coupling heat transfer in solid and fluid zones. • Seven different cases are considered to observe trends in predicted temperature and pressure. • The seven cases consider high/medium/low power, flow, burnup, fuel material and geometry. • Simulations provide temperature predictions for performance/safety. Boiling is unlikely. • Simulations demonstrate that a candidate geometry can enhance performance/safety. - Abstract: The current work presents numerical simulations of coupled fluid flow and heat transfer of advanced U–Mo/Al and U–Mo/Mg research reactor fuels in support of performance and safety analyses. The objective of this study is to enhance predictions of the flow regime and fuel temperatures through high fidelity simulations that better capture various heat transfer pathways and with a more realistic geometric representation of the fuel assembly in comparison to previous efforts. Specifically, thermal conduction, convection and radiation mechanisms are conjugated between the solid and fluid regions. Also, a complete fuel element assembly is represented in three dimensional space, permitting fluid flow and heat transfer to be simulated across the entire domain. Seven case studies are examined that vary the coolant inlet conditions, specific power, and burnup to investigate the predicted changes in the pressure drop in the coolant and the fuel, clad and coolant temperatures. In addition, an alternate fuel geometry is considered with helical fins (replacing straight fins in the existing design) to investigate the relative changes in predicted fluid and solid temperatures. Numerical simulations predict that the clad temperature is sensitive to changes in the thermal boundary layer in the coolant, particularly in simultaneously developing flow regions, while the temperature in the fuel is anticipated to be unaffected. Finally, heat transfer between fluid and solid regions is enhanced with

  1. Investigation of the composition of arterial plaques based on arterial waveforms and material properties.

    Science.gov (United States)

    Feng, J; Rajeswaran, T; He, S; Wilkinson, F L; Serracino-Inglott, F; Azzawi, M; Parikh, V; Miraftab, M; Alexander, M Y

    2015-08-01

    Stroke is mainly caused by a narrowing of the carotid artery from a build-up of plaque. The risk of plaque rupture and subsequent stroke is dependent on plaque composition. Advances in imaging modalities offer a non-invasive means to assess the health of blood vessels and detect damage. However, the current diagnosis fails to identify patients with soft lipid plaque that are more susceptible to fissure, resulting in stroke. The aim of this study was to use waveform analysis to identify plaque composition and the risk of rupture. We have investigated pressure and flow by combining an artificial blood flow circuit with tubing containing different materials, to simulate plaques in a blood vessel. We used fat and bone to model lipid and calcification respectively to determine if the composition of plaques can be identified by arterial waveforms. We demonstrate that the arterial plaque models with different percentages of calcification and fat, results in significantly different arterial waveforms. These findings imply that arterial waveform analysis has the potential for further development to identify the vulnerable plaques prone to rupture. These findings could have implications for improved patient prognosis by speed of detection and a more appropriate treatment strategy. PMID:26736431

  2. Fast and Accurate Prediction of Numerical Relativity Waveforms from Binary Black Hole Coalescences Using Surrogate Models.

    Science.gov (United States)

    Blackman, Jonathan; Field, Scott E; Galley, Chad R; Szilágyi, Béla; Scheel, Mark A; Tiglio, Manuel; Hemberger, Daniel A

    2015-09-18

    Simulating a binary black hole coalescence by solving Einstein's equations is computationally expensive, requiring days to months of supercomputing time. Using reduced order modeling techniques, we construct an accurate surrogate model, which is evaluated in a millisecond to a second, for numerical relativity (NR) waveforms from nonspinning binary black hole coalescences with mass ratios in [1, 10] and durations corresponding to about 15 orbits before merger. We assess the model's uncertainty and show that our modeling strategy predicts NR waveforms not used for the surrogate's training with errors nearly as small as the numerical error of the NR code. Our model includes all spherical-harmonic _{-2}Y_{ℓm} waveform modes resolved by the NR code up to ℓ=8. We compare our surrogate model to effective one body waveforms from 50M_{⊙} to 300M_{⊙} for advanced LIGO detectors and find that the surrogate is always more faithful (by at least an order of magnitude in most cases). PMID:26430979

  3. A Virtual Engineering Framework for Simulating Advanced Power System

    Energy Technology Data Exchange (ETDEWEB)

    Mike Bockelie; Dave Swensen; Martin Denison; Stanislav Borodai

    2008-06-18

    In this report is described the work effort performed to provide NETL with VE-Suite based Virtual Engineering software and enhanced equipment models to support NETL's Advanced Process Engineering Co-simulation (APECS) framework for advanced power generation systems. Enhancements to the software framework facilitated an important link between APECS and the virtual engineering capabilities provided by VE-Suite (e.g., equipment and process visualization, information assimilation). Model enhancements focused on improving predictions for the performance of entrained flow coal gasifiers and important auxiliary equipment (e.g., Air Separation Units) used in coal gasification systems. In addition, a Reduced Order Model generation tool and software to provide a coupling between APECS/AspenPlus and the GE GateCycle simulation system were developed. CAPE-Open model interfaces were employed where needed. The improved simulation capability is demonstrated on selected test problems. As part of the project an Advisory Panel was formed to provide guidance on the issues on which to focus the work effort. The Advisory Panel included experts from industry and academics in gasification, CO2 capture issues, process simulation and representatives from technology developers and the electric utility industry. To optimize the benefit to NETL, REI coordinated its efforts with NETL and NETL funded projects at Iowa State University, Carnegie Mellon University and ANSYS/Fluent, Inc. The improved simulation capabilities incorporated into APECS will enable researchers and engineers to better understand the interactions of different equipment components, identify weaknesses and processes needing improvement and thereby allow more efficient, less expensive plants to be developed and brought on-line faster and in a more cost-effective manner. These enhancements to APECS represent an important step toward having a fully integrated environment for performing plant simulation and engineering

  4. Tools for advanced simulations to nuclear propulsion systems in rockets

    Energy Technology Data Exchange (ETDEWEB)

    Torres Sepulveda, A.; Perez Vara, R.

    2004-07-01

    While chemical propulsion rockets have dominated space exploration, other forms of rocket propulsion based on nuclear power, electrostatic and magnetic drive, and other principles besides chemical reactions, have been considered from the earliest days of the field. The goal of most of these advanced rocket propulsion schemes is improved efficiency through higher exhaust velocities, in order to reduce the amount of fuel the rocket vehicle needs to carry, though generally at the expense of high thrust. Nuclear propulsion seems to be the most promising short term technology to plan realistic interplanetary missions. The development of a nuclear electric propulsion spacecraft shall require the development of models to analyse the mission and to understand the interaction between the related subsystems (nuclear reactor, electrical converter, power management and distribution, and electric propulsion) during the different phases of the mission. This paper explores the modelling of a nuclear electric propulsion (NEP) spacecraft type using EcosimPro simulation software. This software is a multi-disciplinary simulation tool with a powerful object-oriented simulation language and state-of-the-art solvers. EcosimPro is the recommended ESA simulation tool for environmental Control and Life Support Systems (ECLSS) and has been used successfully within the framework of the European activities of the International Space Station programme. Furthermore, propulsion libraries for chemical and electrical propulsion are currently being developed under ESA contracts to set this tool as standard usage in the propulsion community. At present, there is not any workable NEP spacecraft, but a standardized-modular, multi-purpose interplanetary spacecraft for post-2000 missions, called ISC-2000, has been proposed in reference. The simulation model presented on this paper is based on the preliminary designs for this spacecraft. (Author)

  5. Investigations and advanced concepts on gyrotron interaction modeling and simulations

    Energy Technology Data Exchange (ETDEWEB)

    Avramidis, K. A., E-mail: konstantinos.avramidis@kit.edu [Institute for Pulsed Power and Microwave Technologies, Karlsruhe Institute of Technology, Karlsruhe 76131 (Germany)

    2015-12-15

    In gyrotron theory, the interaction between the electron beam and the high frequency electromagnetic field is commonly modeled using the slow variables approach. The slow variables are quantities that vary slowly in time in comparison to the electron cyclotron frequency. They represent the electron momentum and the high frequency field of the resonant TE modes in the gyrotron cavity. For their definition, some reference frequencies need to be introduced. These include the so-called averaging frequency, used to define the slow variable corresponding to the electron momentum, and the carrier frequencies, used to define the slow variables corresponding to the field envelopes of the modes. From the mathematical point of view, the choice of the reference frequencies is, to some extent, arbitrary. However, from the numerical point of view, there are arguments that point toward specific choices, in the sense that these choices are advantageous in terms of simulation speed and accuracy. In this paper, the typical monochromatic gyrotron operation is considered, and the numerical integration of the interaction equations is performed by the trajectory approach, since it is the fastest, and therefore it is the one that is most commonly used. The influence of the choice of the reference frequencies on the interaction simulations is studied using theoretical arguments, as well as numerical simulations. From these investigations, appropriate choices for the values of the reference frequencies are identified. In addition, novel, advanced concepts for the definitions of these frequencies are addressed, and their benefits are demonstrated numerically.

  6. Advanced modeling and simulation to design and manufacture high performance and reliable advanced microelectronics and microsystems.

    Energy Technology Data Exchange (ETDEWEB)

    Nettleship, Ian (University of Pittsburgh, Pittsburgh, PA); Hinklin, Thomas; Holcomb, David Joseph; Tandon, Rajan; Arguello, Jose Guadalupe, Jr. (,; .); Dempsey, James Franklin; Ewsuk, Kevin Gregory; Neilsen, Michael K.; Lanagan, Michael (Pennsylvania State University, University Park, PA)

    2007-07-01

    An interdisciplinary team of scientists and engineers having broad expertise in materials processing and properties, materials characterization, and computational mechanics was assembled to develop science-based modeling/simulation technology to design and reproducibly manufacture high performance and reliable, complex microelectronics and microsystems. The team's efforts focused on defining and developing a science-based infrastructure to enable predictive compaction, sintering, stress, and thermomechanical modeling in ''real systems'', including: (1) developing techniques to and determining materials properties and constitutive behavior required for modeling; (2) developing new, improved/updated models and modeling capabilities, (3) ensuring that models are representative of the physical phenomena being simulated; and (4) assessing existing modeling capabilities to identify advances necessary to facilitate the practical application of Sandia's predictive modeling technology.

  7. Electronics via waveform analysis

    CERN Document Server

    Craig, Edwin C

    1993-01-01

    The author believes that a good basic understanding of electronics can be achieved by detailed visual analyses of the actual voltage waveforms present in selected circuits. The voltage waveforms included in this text were photographed using a 35-rrun camera in an attempt to make the book more attractive. This book is intended for the use of students with a variety of backgrounds. For this reason considerable material has been placed in the Appendix for those students who find it useful. The Appendix includes many basic electricity and electronic concepts as well as mathematical derivations that are not vital to the understanding of the circuit being discussed in the text at that time. Also some derivations might be so long that, if included in the text, it could affect the concentration of the student on the circuit being studied. The author has tried to make the book comprehensive enough so that a student could use it as a self-study course, providing one has access to adequate laboratory equipment.

  8. Analysis of LFM-waveform Libraries for Cognitive Tracking Maneuvering Targets

    Directory of Open Access Journals (Sweden)

    Wang Hongyan

    2016-01-01

    Full Text Available Based on the idea of the waveform agility in cognitive radars,the waveform libraries for maneuvering target tracking are discussed. LFM-waveform libraries are designed according to different combinations of chirp parameters and FrFT rotation angles. By applying the interact multiple model (IMM algorithm in tracking maneuvering targets, transmitted waveform is called real time from the LFM-waveform libraries. The waveforms are selected from the library according to the criterion of maximum mutual information between the current state of knowledge of the model and the measurement. Simulation results show that waveform library containing certain amount LFM-waveforms can improve the performance of cognitive tracking radar.

  9. Study on advancement of in vivo counting using mathematical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kinase, Sakae [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-05-01

    To obtain an assessment of the committed effective dose, individual monitoring for the estimation of intakes of radionuclides is required. For individual monitoring of exposure to intakes of radionuclides, direct measurement of radionuclides in the body - in vivo counting- is very useful. To advance in a precision in vivo counting which fulfills the requirements of ICRP 1990 recommendations, some problems, such as the investigation of uncertainties in estimates of body burdens by in vivo counting, and the selection of the way to improve the precision, have been studied. In the present study, a calibration technique for in vivo counting application using Monte Carlo simulation was developed. The advantage of the technique is that counting efficiency can be obtained for various shapes and sizes that are very difficult to change for phantoms. To validate the calibration technique, the response functions and counting efficiencies of a whole-body counter installed in JAERI were evaluated using the simulation and measurements. Consequently, the calculations are in good agreement with the measurements. The method for the determination of counting efficiency curves as a function of energy was developed using the present technique and a physiques correction equation was derived from the relationship between parameters of correction factor and counting efficiencies of the JAERI whole-body counter. The uncertainties in body burdens of {sup 137}Cs estimated with the JAERI whole-body counter were also investigated using the Monte Carlo simulation and measurements. It was found that the uncertainties of body burdens estimated with the whole-body counter are strongly dependent on various sources of uncertainty such as radioactivity distribution within the body and counting statistics. Furthermore, the evaluation method of the peak efficiencies of a Ge semi-conductor detector was developed by Monte Carlo simulation for optimum arrangement of Ge semi-conductor detectors for

  10. Study on advancement of in vivo counting using mathematical simulation

    International Nuclear Information System (INIS)

    To obtain an assessment of the committed effective dose, individual monitoring for the estimation of intakes of radionuclides is required. For individual monitoring of exposure to intakes of radionuclides, direct measurement of radionuclides in the body - in vivo counting- is very useful. To advance in a precision in vivo counting which fulfills the requirements of ICRP 1990 recommendations, some problems, such as the investigation of uncertainties in estimates of body burdens by in vivo counting, and the selection of the way to improve the precision, have been studied. In the present study, a calibration technique for in vivo counting application using Monte Carlo simulation was developed. The advantage of the technique is that counting efficiency can be obtained for various shapes and sizes that are very difficult to change for phantoms. To validate the calibration technique, the response functions and counting efficiencies of a whole-body counter installed in JAERI were evaluated using the simulation and measurements. Consequently, the calculations are in good agreement with the measurements. The method for the determination of counting efficiency curves as a function of energy was developed using the present technique and a physiques correction equation was derived from the relationship between parameters of correction factor and counting efficiencies of the JAERI whole-body counter. The uncertainties in body burdens of 137Cs estimated with the JAERI whole-body counter were also investigated using the Monte Carlo simulation and measurements. It was found that the uncertainties of body burdens estimated with the whole-body counter are strongly dependent on various sources of uncertainty such as radioactivity distribution within the body and counting statistics. Furthermore, the evaluation method of the peak efficiencies of a Ge semi-conductor detector was developed by Monte Carlo simulation for optimum arrangement of Ge semi-conductor detectors for designing a

  11. TID Simulation of Advanced CMOS Devices for Space Applications

    Science.gov (United States)

    Sajid, Muhammad

    2016-07-01

    This paper focuses on Total Ionizing Dose (TID) effects caused by accumulation of charges at silicon dioxide, substrate/silicon dioxide interface, Shallow Trench Isolation (STI) for scaled CMOS bulk devices as well as at Buried Oxide (BOX) layer in devices based on Silicon-On-Insulator (SOI) technology to be operated in space radiation environment. The radiation induced leakage current and corresponding density/concentration electrons in leakage current path was presented/depicted for 180nm, 130nm and 65nm NMOS, PMOS transistors based on CMOS bulk as well as SOI process technologies on-board LEO and GEO satellites. On the basis of simulation results, the TID robustness analysis for advanced deep sub-micron technologies was accomplished up to 500 Krad. The correlation between the impact of technology scaling and magnitude of leakage current with corresponding total dose was established utilizing Visual TCAD Genius program.

  12. A study of reset mode in advanced alarm system simulator

    International Nuclear Information System (INIS)

    An automation function has been widely applied in main control room of nuclear power plants. That leads to a new issue of human-automation interaction, which considers human operational performance in automated systems. In this research is the automation alarm reset in the advanced alarm system (AAS) of Advanced Nuclear Power Plant in Taiwan. Since alarms are very crucial for the understanding of the status of the plant as well as the reset function of alarm system will be changed from fully manual to fully automatic, it is very important to test and evaluate the performance and the effect of reset modes in AAS. The purpose of this paper is to evaluate the impact of the auto-reset alarm system on the plant performance and on operators' preference and task load. To develop a dynamic simulator as an AAS was conducted to compare manual and automatic reset function of alarm system on task performance and subjective ratings of task workload, comprehension, and preference. The simulation includes PCTRAN model and alarm software processing. The final results revealed that, using the auto-reset mode, participants had lower task load index (TLX) on effort in the first test trial and was more satisfied in multiple tasks condition. In contrast, using manual reset mode, participants were more satisfied on alarm handling, monitoring, and decision making. In other words, either reset mode in the study has unique features to assist operator, but is insufficient. The reset function in AAS therefore should be very flexible. Additionally, the experimental results also pointed out that the user interfaces need to be improved. Those experiences will be helpful for human factors verification and validation in the near future. (authors)

  13. Simulated Interactive Research Experiments as Educational Tools for Advanced Science

    Science.gov (United States)

    Tomandl, Mathias; Mieling, Thomas; Losert-Valiente Kroon, Christiane M.; Hopf, Martin; Arndt, Markus

    2015-09-01

    Experimental research has become complex and thus a challenge to science education. Only very few students can typically be trained on advanced scientific equipment. It is therefore important to find new tools that allow all students to acquire laboratory skills individually and independent of where they are located. In a design-based research process we have investigated the feasibility of using a virtual laboratory as a photo-realistic and scientifically valid representation of advanced scientific infrastructure to teach modern experimental science, here, molecular quantum optics. We found a concept based on three educational principles that allows undergraduate students to become acquainted with procedures and concepts of a modern research field. We find a significant increase in student understanding using our Simulated Interactive Research Experiment (SiReX), by evaluating the learning outcomes with semi-structured interviews in a pre/post design. This suggests that this concept of an educational tool can be generalized to disseminate findings in other fields.

  14. Waveform sample method of excitable sensory neuron

    OpenAIRE

    Wang, Sheng-Jun; Xu, Xin-Jian; Wang, Ying-Hai

    2006-01-01

    We present a new interpretation for encoding information of the period of input signals into spike-trains in individual sensory neuronal systems. The spike-train could be described as the waveform sample of the input signal which locks sample points to wave crests with randomness. Based on simulations of the Hodgkin-Huxley (HH) neuron responding to periodic inputs, we demonstrate that the random sampling is a proper encoding method in medium frequency region since power spectra of the reconst...

  15. Advancements in Afterbody Radiative Heating Simulations for Earth Entry

    Science.gov (United States)

    Johnston, Christopher O.; Panesi, Marco; Brandis, Aaron M.

    2016-01-01

    Four advancements to the simulation of backshell radiative heating for Earth entry are presented. The first of these is the development of a flow field model that treats electronic levels of the dominant backshell radiator, N, as individual species. This is shown to allow improvements in the modeling of electron-ion recombination and two-temperature modeling, which are shown to increase backshell radiative heating by 10 to 40%. By computing the electronic state populations of N within the flow field solver, instead of through the quasi-steady state approximation in the radiation code, the coupling of radiative transition rates to the species continuity equations for the levels of N, including the impact of non-local absorption, becomes feasible. Implementation of this additional level of coupling between the flow field and radiation codes represents the second advancement presented in this work, which is shown to increase the backshell radiation by another 10 to 50%. The impact of radiative transition rates due to non-local absorption indicates the importance of accurate radiation transport in the relatively complex flow geometry of the backshell. This motivates the third advancement, which is the development of a ray-tracing radiation transport approach to compute the radiative transition rates and divergence of the radiative flux at every point for coupling to the flow field, therefore allowing the accuracy of the commonly applied tangent-slab approximation to be assessed for radiative source terms. For the sphere considered at lunar-return conditions, the tangent-slab approximation is shown to provide a sufficient level of accuracy for the radiative source terms, even for backshell cases. This is in contrast to the agreement between the two approaches for computing the radiative flux to the surface, which differ by up to 40%. The final advancement presented is the development of a nonequilibrium model for NO radiation, which provides significant backshell

  16. Waveform analysis of sound

    CERN Document Server

    Tohyama, Mikio

    2015-01-01

    What is this sound? What does that sound indicate? These are two questions frequently heard in daily conversation. Sound results from the vibrations of elastic media and in daily life provides informative signals of events happening in the surrounding environment. In interpreting auditory sensations, the human ear seems particularly good at extracting the signal signatures from sound waves. Although exploring auditory processing schemes may be beyond our capabilities, source signature analysis is a very attractive area in which signal-processing schemes can be developed using mathematical expressions. This book is inspired by such processing schemes and is oriented to signature analysis of waveforms. Most of the examples in the book are taken from data of sound and vibrations; however, the methods and theories are mostly formulated using mathematical expressions rather than by acoustical interpretation. This book might therefore be attractive and informative for scientists, engineers, researchers, and graduat...

  17. The advanced computational testing and simulation toolkit (ACTS)

    Energy Technology Data Exchange (ETDEWEB)

    Drummond, L.A.; Marques, O.

    2002-05-21

    During the past decades there has been a continuous growth in the number of physical and societal problems that have been successfully studied and solved by means of computational modeling and simulation. Distinctively, a number of these are important scientific problems ranging in scale from the atomic to the cosmic. For example, ionization is a phenomenon as ubiquitous in modern society as the glow of fluorescent lights and the etching on silicon computer chips; but it was not until 1999 that researchers finally achieved a complete numerical solution to the simplest example of ionization, the collision of a hydrogen atom with an electron. On the opposite scale, cosmologists have long wondered whether the expansion of the Universe, which began with the Big Bang, would ever reverse itself, ending the Universe in a Big Crunch. In 2000, analysis of new measurements of the cosmic microwave background radiation showed that the geometry of the Universe is flat, and thus the Universe will continue expanding forever. Both of these discoveries depended on high performance computer simulations that utilized computational tools included in the Advanced Computational Testing and Simulation (ACTS) Toolkit. The ACTS Toolkit is an umbrella project that brought together a number of general purpose computational tool development projects funded and supported by the U.S. Department of Energy (DOE). These tools, which have been developed independently, mainly at DOE laboratories, make it easier for scientific code developers to write high performance applications for parallel computers. They tackle a number of computational issues that are common to a large number of scientific applications, mainly implementation of numerical algorithms, and support for code development, execution and optimization. The ACTS Toolkit Project enables the use of these tools by a much wider community of computational scientists, and promotes code portability, reusability, reduction of duplicate efforts

  18. Enabling Advanced Modeling and Simulations for Fuel-Flexible Combustors

    Energy Technology Data Exchange (ETDEWEB)

    Heinz Pitsch

    2010-05-31

    The overall goal of the present project is to enable advanced modeling and simulations for the design and optimization of fuel-flexible turbine combustors. For this purpose we use a high-fidelity, extensively-tested large-eddy simulation (LES) code and state-of-the-art models for premixed/partially-premixed turbulent combustion developed in the PI's group. In the frame of the present project, these techniques are applied, assessed, and improved for hydrogen enriched premixed and partially premixed gas-turbine combustion. Our innovative approaches include a completely consistent description of flame propagation, a coupled progress variable/level set method to resolve the detailed flame structure, and incorporation of thermal-diffusion (non-unity Lewis number) effects. In addition, we have developed a general flamelet-type transformation holding in the limits of both non-premixed and premixed burning. As a result, a model for partially premixed combustion has been derived. The coupled progress variable/level method and the general flamelet tranformation were validated by LES of a lean-premixed low-swirl burner that has been studied experimentally at Lawrence Berkeley National Laboratory. The model is extended to include the non-unity Lewis number effects, which play a critical role in fuel-flexible combustor with high hydrogen content fuel. More specifically, a two-scalar model for lean hydrogen and hydrogen-enriched combustion is developed and validated against experimental and direct numerical simulation (DNS) data. Results are presented to emphasize the importance of non-unity Lewis number effects in the lean-premixed low-swirl burner of interest in this project. The proposed model gives improved results, which shows that the inclusion of the non-unity Lewis number effects is essential for accurate prediction of the lean-premixed low-swirl flame.

  19. Enabling Advanced Modeling and Simulations for Fuel-Flexible Combustors

    Energy Technology Data Exchange (ETDEWEB)

    Pitsch, Heinz

    2010-05-31

    The overall goal of the present project is to enable advanced modeling and simulations for the design and optimization of fuel-flexible turbine combustors. For this purpose we use a high fidelity, extensively-tested large-eddy simulation (LES) code and state-of-the-art models for premixed/partially-premixed turbulent combustion developed in the PI's group. In the frame of the present project, these techniques are applied, assessed, and improved for hydrogen enriched premixed and partially premixed gas-turbine combustion. Our innovative approaches include a completely consistent description of flame propagation; a coupled progress variable/level set method to resolve the detailed flame structure, and incorporation of thermal-diffusion (non-unity Lewis number) effects. In addition, we have developed a general flamelet-type transformation holding in the limits of both non-premixed and premixed burning. As a result, a model for partially premixed combustion has been derived. The coupled progress variable/level method and the general flamelet transformation were validated by LES of a lean-premixed low-swirl burner that has been studied experimentally at Lawrence Berkeley National Laboratory. The model is extended to include the non-unity Lewis number effects, which play a critical role in fuel-flexible combustor with high hydrogen content fuel. More specifically, a two-scalar model for lean hydrogen and hydrogen-enriched combustion is developed and validated against experimental and direct numerical simulation (DNS) data. Results are presented to emphasize the importance of non-unity Lewis number effects in the lean-premixed low-swirl burner of interest in this project. The proposed model gives improved results, which shows that the inclusion of the non-unity Lewis number effects is essential for accurate prediction of the lean-premixed low-swirl flame.

  20. The advanced computational testing and simulation toolkit (ACTS)

    International Nuclear Information System (INIS)

    During the past decades there has been a continuous growth in the number of physical and societal problems that have been successfully studied and solved by means of computational modeling and simulation. Distinctively, a number of these are important scientific problems ranging in scale from the atomic to the cosmic. For example, ionization is a phenomenon as ubiquitous in modern society as the glow of fluorescent lights and the etching on silicon computer chips; but it was not until 1999 that researchers finally achieved a complete numerical solution to the simplest example of ionization, the collision of a hydrogen atom with an electron. On the opposite scale, cosmologists have long wondered whether the expansion of the Universe, which began with the Big Bang, would ever reverse itself, ending the Universe in a Big Crunch. In 2000, analysis of new measurements of the cosmic microwave background radiation showed that the geometry of the Universe is flat, and thus the Universe will continue expanding forever. Both of these discoveries depended on high performance computer simulations that utilized computational tools included in the Advanced Computational Testing and Simulation (ACTS) Toolkit. The ACTS Toolkit is an umbrella project that brought together a number of general purpose computational tool development projects funded and supported by the U.S. Department of Energy (DOE). These tools, which have been developed independently, mainly at DOE laboratories, make it easier for scientific code developers to write high performance applications for parallel computers. They tackle a number of computational issues that are common to a large number of scientific applications, mainly implementation of numerical algorithms, and support for code development, execution and optimization. The ACTS Toolkit Project enables the use of these tools by a much wider community of computational scientists, and promotes code portability, reusability, reduction of duplicate efforts

  1. Waveform diversity for wireless sensing

    Science.gov (United States)

    Qureshi, Tariq; Zoltowski, Michael

    2008-04-01

    In active sensing systems such as radar and sensor networks, one is interested in transmitting waveforms that possess an ideal thumbtack shaped ambiguity function. However, the synthesis of waveforms with the desired ambiguity function is a difficult problem in applied mathematics and more often than not, one needs to rely on developing waveforms with an ambiguity function that is close to the desired ambiguity function in some sense. Designing waveforms with ambiguity functions that possess certain desirable properties has been a well researched problem in the field of signal analysis. In this paper, we present a methodology for designing multiantenna adaptive waveforms with autocorrelation functions that allow perfect separation at the receiver. We focus on the 4×4 case and derive the conditions that the four waveforms must satisfy in order to achieve perfect separation. Using these conditions, we show that waveforms constructed using Golay complementary sequences, barker codes and quarter-band signals through kronecker products satisfy these conditions and are therefore seperable at the receiver. We also give examples of more general wavefom families that are matched to the environment and also of waveforms that do not necessarily satisfy the conditions for perfect separation but still have good delay-Doppler ambiguity functions making them suitable for sensing environments.

  2. Simulation of 'pathologic' changes in ICG waveforms resulting from superposition of the 'preejection' and ejection waves induced by left ventricular contraction

    Science.gov (United States)

    Ermishkin, V. V.; Kolesnikov, V. A.; Lukoshkova, E. V.; Sonina, R. S.

    2013-04-01

    The impedance cardiography (ICG) is widely used for beat-to-beat noninvasive evaluation of the left ventricular stroke volume and contractility. It implies the correct determination of the ejection start and end points and the amplitudes of certain peaks in the differentiated impedance cardiogram. An accurate identification of ejection onset by ICG is often problematic, especially in the cardiologic patients, due to peculiar waveforms. Using a simple theoretical model, we tested the hypothesis that two major processes are responsible for the formation of impedance systolic wave: (1) the changes in the heart geometry and surrounding vessels produced by ventricular contraction, which occur during the isovolumic phase and precede ejection, and (2) expansion of aorta and adjacent arteries during the ejection phase. The former process initiates the preejection wave WpE and the latter triggers the ejection wave WEj. The model predicts a potential mechanism of generating the abnormal shapes of dZ/dt due to the presence of preejection waves and explains the related errors in ICG time and amplitude parameters. An appropriate decomposition method is a promising way to avoid the masking effects of these waves and a further step to correct determination of the onset of ejection and the corresponding peak amplitudes from 'pathologically shaped' ICG signals.

  3. Active-Learning Diabetes Simulation in an Advanced Pharmacy Practice Experience to Develop Patient Empathy

    OpenAIRE

    Whitley, Heather P.

    2012-01-01

    Objective. To develop and integrate an active-learning diabetes simulation into an advanced pharmacy practice experience to improve pharmacy students’ empathy toward patients with diabetes mellitus.

  4. ADVANCED TECHNIQUES FOR RESERVOIR SIMULATION AND MODELING OF NONCONVENTIONAL WELLS

    Energy Technology Data Exchange (ETDEWEB)

    Louis J. Durlofsky; Khalid Aziz

    2004-08-20

    Nonconventional wells, which include horizontal, deviated, multilateral and ''smart'' wells, offer great potential for the efficient management of oil and gas reservoirs. These wells are able to contact larger regions of the reservoir than conventional wells and can also be used to target isolated hydrocarbon accumulations. The use of nonconventional wells instrumented with downhole inflow control devices allows for even greater flexibility in production. Because nonconventional wells can be very expensive to drill, complete and instrument, it is important to be able to optimize their deployment, which requires the accurate prediction of their performance. However, predictions of nonconventional well performance are often inaccurate. This is likely due to inadequacies in some of the reservoir engineering and reservoir simulation tools used to model and optimize nonconventional well performance. A number of new issues arise in the modeling and optimization of nonconventional wells. For example, the optimal use of downhole inflow control devices has not been addressed for practical problems. In addition, the impact of geological and engineering uncertainty (e.g., valve reliability) has not been previously considered. In order to model and optimize nonconventional wells in different settings, it is essential that the tools be implemented into a general reservoir simulator. This simulator must be sufficiently general and robust and must in addition be linked to a sophisticated well model. Our research under this five year project addressed all of the key areas indicated above. The overall project was divided into three main categories: (1) advanced reservoir simulation techniques for modeling nonconventional wells; (2) improved techniques for computing well productivity (for use in reservoir engineering calculations) and for coupling the well to the simulator (which includes the accurate calculation of well index and the modeling of multiphase flow

  5. Recent Developments in Radar Waveforms (in English)

    OpenAIRE

    Cao Si-yang; Zheng Yuan-fang

    2014-01-01

    With the development of high speed digital processor and solid state power electronics, more flexible waveforms become feasible to achieve by modern radar systems. In fact, the choice of waveforms has a significant impact on the performance of radar systems. In this paper, we review the conventional radar waveform design as well as explore the new generation of waveforms via different theoretical methods, including the most recent wavelet based waveforms. It is shown that the waveform design ...

  6. Advanced Simulation Capability for Environmental Management: Development and Demonstrations - 12532

    International Nuclear Information System (INIS)

    The U.S. Department of Energy Office of Environmental Management (EM), Technology Innovation and Development is supporting development of the Advanced Simulation Capability for Environmental Management (ASCEM). ASCEM is a state-of-the-art scientific tool and approach for understanding and predicting contaminant fate and transport in natural and engineered systems. The modular and open source high-performance computing tool facilitates integrated approaches to modeling and site characterization that enable robust and standardized assessments of performance and risk for EM cleanup and closure activities. The ASCEM project continues to make significant progress in development of capabilities, which are organized into Platform and Integrated Tool-sets and a High-Performance Computing Multi-process Simulator. The Platform capabilities target a level of functionality to allow end-to-end model development, starting with definition of the conceptual model and management of data for model input. The High-Performance Computing capabilities target increased functionality of process model representations, tool-sets for interaction with Platform, and verification and model confidence testing. The new capabilities are demonstrated through working groups, including one focused on the Hanford Site Deep Vadose Zone. The ASCEM program focused on planning during the first year and executing a prototype tool-set for an early demonstration of individual components. Subsequently, ASCEM has focused on developing and demonstrating an integrated set of capabilities, making progress toward a version of the capabilities that can be used to engage end users. Demonstration of capabilities continues to be implemented through working groups. Three different working groups, one focused on EM problems in the deep vadose zone, another investigating attenuation mechanisms for metals and radionuclides, and a third focusing on waste tank performance assessment, continue to make progress. The project

  7. Design and simulation of advanced charge recovery piezoactuator drivers

    International Nuclear Information System (INIS)

    The German Artificial Sphincter System project aims at the development of an implantable sphincter prosthesis driven by a piezoelectrically actuated micropump. The system has been designed to be fully implantable, i.e. the power supply is provided by a rechargeable lithium polymer battery. In order to provide sufficient battery duration and to limit battery dimensions, special effort has to be made to minimize power consumption of the whole system and, in particular, of the piezoactuator driver circuitry. Inductive charge recovery can be used to recover part of the charge stored within the actuator. We are going to present a simplified inductor-based circuit capable of voltage inversion across the actuator without the need of an additional negative voltage source. The dimension of the inductors required for such a concept is nevertheless significant. We therefore present a novel alternative concept, called direct switching, where the equivalent capacitance of the actuator is charged directly by a step-up converter and discharged by a step-down converter. We achieved superior performance compared to a simple inductor-based driver with the advantage of using small-size chip inductors. As a term of comparison, the performance of the aforementioned drivers is compared to a conventional driver that does not implement any charge recovery technique. With our design we have been able to achieve more than 50% reduction in power consumption compared to the simplest conventional driver. The new direct switching driver performs 15% better than an inductor-based driver. A novel, whole-system SPICE simulation is presented, where both the driving circuit and the piezoactuator are modeled making use of advanced nonlinear models. Such a simulation is a precious tool to design and optimize piezoactuator drivers

  8. The effect of inlet waveforms on computational hemodynamics of patient-specific intracranial aneurysms.

    Science.gov (United States)

    Xiang, J; Siddiqui, A H; Meng, H

    2014-12-18

    Due to the lack of patient-specific inlet flow waveform measurements, most computational fluid dynamics (CFD) simulations of intracranial aneurysms usually employ waveforms that are not patient-specific as inlet boundary conditions for the computational model. The current study examined how this assumption affects the predicted hemodynamics in patient-specific aneurysm geometries. We examined wall shear stress (WSS) and oscillatory shear index (OSI), the two most widely studied hemodynamic quantities that have been shown to predict aneurysm rupture, as well as maximal WSS (MWSS), energy loss (EL) and pressure loss coefficient (PLc). Sixteen pulsatile CFD simulations were carried out on four typical saccular aneurysms using 4 different waveforms and an identical inflow rate as inlet boundary conditions. Our results demonstrated that under the same mean inflow rate, different waveforms produced almost identical WSS distributions and WSS magnitudes, similar OSI distributions but drastically different OSI magnitudes. The OSI magnitude is correlated with the pulsatility index of the waveform. Furthermore, there is a linear relationship between aneurysm-averaged OSI values calculated from one waveform and those calculated from another waveform. In addition, different waveforms produced similar MWSS, EL and PLc in each aneurysm. In conclusion, inlet waveform has minimal effects on WSS, OSI distribution, MWSS, EL and PLc and a strong effect on OSI magnitude, but aneurysm-averaged OSI from different waveforms has a strong linear correlation with each other across different aneurysms, indicating that for the same aneurysm cohort, different waveforms can consistently stratify (rank) OSI of aneurysms. PMID:25446264

  9. Waveform Catalog, Extreme Mass Ratio Binary (Capture)

    Data.gov (United States)

    National Aeronautics and Space Administration — Numerically-generated gravitational waveforms for circular inspiral into Kerr black holes. These waveforms were developed using Scott Hughes' black hole...

  10. Modeling and simulation challenges pursued by the Consortium for Advanced Simulation of Light Water Reactors (CASL)

    Science.gov (United States)

    Turinsky, Paul J.; Kothe, Douglas B.

    2016-05-01

    The Consortium for the Advanced Simulation of Light Water Reactors (CASL), the first Energy Innovation Hub of the Department of Energy, was established in 2010 with the goal of providing modeling and simulation (M&S) capabilities that support and accelerate the improvement of nuclear energy's economic competitiveness and the reduction of spent nuclear fuel volume per unit energy, and all while assuring nuclear safety. To accomplish this requires advances in M&S capabilities in radiation transport, thermal-hydraulics, fuel performance and corrosion chemistry. To focus CASL's R&D, industry challenge problems have been defined, which equate with long standing issues of the nuclear power industry that M&S can assist in addressing. To date CASL has developed a multi-physics "core simulator" based upon pin-resolved radiation transport and subchannel (within fuel assembly) thermal-hydraulics, capitalizing on the capabilities of high performance computing. CASL's fuel performance M&S capability can also be optionally integrated into the core simulator, yielding a coupled multi-physics capability with untapped predictive potential. Material models have been developed to enhance predictive capabilities of fuel clad creep and growth, along with deeper understanding of zirconium alloy clad oxidation and hydrogen pickup. Understanding of corrosion chemistry (e.g., CRUD formation) has evolved at all scales: micro, meso and macro. CFD R&D has focused on improvement in closure models for subcooled boiling and bubbly flow, and the formulation of robust numerical solution algorithms. For multiphysics integration, several iterative acceleration methods have been assessed, illuminating areas where further research is needed. Finally, uncertainty quantification and data assimilation techniques, based upon sampling approaches, have been made more feasible for practicing nuclear engineers via R&D on dimensional reduction and biased sampling. Industry adoption of CASL's evolving M

  11. Multiples waveform inversion

    KAUST Repository

    Zhang, D. L.

    2013-01-01

    To increase the illumination of the subsurface and to eliminate the dependency of FWI on the source wavelet, we propose multiples waveform inversion (MWI) that transforms each hydrophone into a virtual point source with a time history equal to that of the recorded data. These virtual sources are used to numerically generate downgoing wavefields that are correlated with the backprojected surface-related multiples to give the migration image. Since the recorded data are treated as the virtual sources, knowledge of the source wavelet is not required, and the subsurface illumination is greatly enhanced because the entire free surface acts as an extended source compared to the radiation pattern of a traditional point source. Numerical tests on the Marmousi2 model show that the convergence rate and the spatial resolution of MWI is, respectively, faster and more accurate then FWI. The potential pitfall with this method is that the multiples undergo more than one roundtrip to the surface, which increases attenuation and reduces spatial resolution. This can lead to less resolved tomograms compared to conventional FWI. The possible solution is to combine both FWI and MWI in inverting for the subsurface velocity distribution.

  12. The Vienna LTE-advanced simulators up and downlink, link and system level simulation

    CERN Document Server

    Rupp, Markus; Taranetz, Martin

    2016-01-01

    This book introduces the Vienna Simulator Suite for 3rd-Generation Partnership Project (3GPP)-compatible Long Term Evolution-Advanced (LTE-A) simulators and presents applications to demonstrate their uses for describing, designing, and optimizing wireless cellular LTE-A networks. Part One addresses LTE and LTE-A link level techniques. As there has been high demand for the downlink (DL) simulator, it constitutes the central focus of the majority of the chapters. This part of the book reports on relevant highlights, including single-user (SU), multi-user (MU) and single-input-single-output (SISO) as well as multiple-input-multiple-output (MIMO) transmissions. Furthermore, it summarizes the optimal pilot pattern for high-speed communications as well as different synchronization issues. One chapter is devoted to experiments that show how the link level simulator can provide input to a testbed. This section also uses measurements to present and validate fundamental results on orthogonal frequency division multiple...

  13. Advanced Simulation Capability for Environmental Management (ASCEM) Phase II Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Freshley, M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hubbard, S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Flach, G. [Savannah River National Lab. (SRNL), Aiken, SC (United States); Freedman, V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Agarwal, D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Andre, B. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Bott, Y. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chen, X. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Davis, J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Faybishenko, B. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gorton, I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Murray, C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Moulton, D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Meyer, J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rockhold, M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Shoshani, A. [LBNL; Steefel, C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wainwright, H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Waichler, S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2012-09-28

    In 2009, the National Academies of Science (NAS) reviewed and validated the U.S. Department of Energy Office of Environmental Management (EM) Technology Program in its publication, Advice on the Department of Energy’s Cleanup Technology Roadmap: Gaps and Bridges. The NAS report outlined prioritization needs for the Groundwater and Soil Remediation Roadmap, concluded that contaminant behavior in the subsurface is poorly understood, and recommended further research in this area as a high priority. To address this NAS concern, the EM Office of Site Restoration began supporting the development of the Advanced Simulation Capability for Environmental Management (ASCEM). ASCEM is a state-of-the-art scientific approach that uses an integration of toolsets for understanding and predicting contaminant fate and transport in natural and engineered systems. The ASCEM modeling toolset is modular and open source. It is divided into three thrust areas: Multi-Process High Performance Computing (HPC), Platform and Integrated Toolsets, and Site Applications. The ASCEM toolsets will facilitate integrated approaches to modeling and site characterization that enable robust and standardized assessments of performance and risk for EM cleanup and closure activities. During fiscal year 2012, the ASCEM project continued to make significant progress in capabilities development. Capability development occurred in both the Platform and Integrated Toolsets and Multi-Process HPC Simulator areas. The new Platform and Integrated Toolsets capabilities provide the user an interface and the tools necessary for end-to-end model development that includes conceptual model definition, data management for model input, model calibration and uncertainty analysis, and model output processing including visualization. The new HPC Simulator capabilities target increased functionality of process model representations, toolsets for interaction with the Platform, and model confidence testing and verification for

  14. Editorial: Advances in Health Education Applying E-Learning, Simulations and Distance Technologies

    OpenAIRE

    Andre W. Kushniruk (ACMI Fellow; CAHS Fellow)

    2011-01-01

    This special issue of the KM&EL international journal is dedicated to coverage of novel advances in health professional education applying e-Learning, simulations and distance education technologies. Modern healthcare is beginning to be transformed through the emergence of new information technologies and rapid advances in health informatics. Advances such as electronic health record systems (EHRs), clinical decision support systems and other advanced information systems such as public health...

  15. Overview of the Consortium for the Advanced Simulation of Light Water Reactors (CASL)

    OpenAIRE

    Kulesza Joel A.; Franceschini Fausto; Evans Thomas M.; Gehin Jess C.

    2016-01-01

    The Consortium for Advanced Simulation of Light Water Reactors (CASL) was established in July 2010 for the purpose of providing advanced modeling and simulation solutions for commercial nuclear reactors. The primary goal is to provide coupled, higher-fidelity, usable modeling and simulation capabilities than are currently available. These are needed to address light water reactor (LWR) operational and safety performance-defining phenomena that are not yet able to be fully modeled taking a fir...

  16. A prototype effective-one-body model for non-precessing spinning inspiral-merger-ringdown waveforms

    CERN Document Server

    Taracchini, Andrea; Buonanno, Alessandra; Barausse, Enrico; Boyle, Michael; Chu, Tony; Lovelace, Geoffrey; Pfeiffer, Harald P; Scheel, Mark A

    2012-01-01

    We first use five non-spinning and two mildly spinning (chi_i \\simeq -0.44, +0.44) numerical-relativity waveforms of black-hole binaries and calibrate an effective-one-body (EOB) model for non-precessing spinning binaries, notably its dynamics and the dominant (2,2) gravitational-wave mode. Then, we combine the above results with recent outcomes of small-mass-ratio simulations produced by the Teukolsky equation and build a prototype EOB model for detection purposes, which is capable of generating inspiral-merger-ringdown waveforms for non-precessing spinning black-hole binaries with any mass ratio and individual black-hole spins -1 \\leq chi_i \\lesssim 0.7. We compare the prototype EOB model to two equal-mass highly spinning numerical-relativity waveforms of black holes with spins chi_i = -0.95, +0.97, which were not available at the time the EOB model was calibrated. In the case of Advanced LIGO we find that the mismatch between prototype-EOB and numerical-relativity waveforms is always smaller than 0.003 for...

  17. Complex Crustal Structure Beneath Western Turkey Revealed by 3D Seismic Full Waveform Inversion (FWI)

    Science.gov (United States)

    Cubuk-Sabuncu, Yesim; Taymaz, Tuncay; Fichtner, Andreas

    2016-04-01

    We present a 3D radially anisotropic velocity model of the crust and uppermost mantle structure beneath the Sea of Marmara and surroundings based on the full waveform inversion method. The intense seismic activity and crustal deformation are observed in the Northwest Turkey due to transition tectonics between the strike-slip North Anatolian Fault (NAF) and the extensional Aegean region. We have selected and simulated complete waveforms of 62 earthquakes (Mw > 4.0) occurred during 2007-2015, and recorded at (Δ Unified Seismic Network (HUSN, Greece) and Earthquake Research Center of Turkey (AFAD-DAD). The spectral-element solver of the wave equation, SES3D algorithm, is used to simulate seismic wave propagation in 3D spherical coordinates (Fichtner, 2009). The Large Scale Seismic Inversion Framework (LASIF) workflow tool is also used to perform full seismic waveform inversion (Krischer et al., 2015). The initial 3D Earth model is implemented from the multi-scale seismic tomography study of Fichtner et al. (2013). Discrepancies between the observed and simulated synthetic waveforms are determined using the time-frequency misfits which allows a separation between phase and amplitude information (Fichtner et al., 2008). The conjugate gradient optimization method is used to iteratively update the initial Earth model when minimizing the misfit. The inversion is terminated after 19 iterations since no further advances are observed in updated models. Our analysis revealed shear wave velocity variations of the shallow and deeper crustal structure beneath western Turkey down to depths of ~35-40 km. Low shear wave velocity anomalies are observed in the upper and mid crustal depths beneath major fault zones located in the study region. Low velocity zones also tend to mark the outline of young volcanic areas. Our final 3D Earth model is tested using forward wave simulations of earthquakes (M ≥ 3.7) that were not used during the inversion process. The comparison of observed

  18. Waveform efficiency analysis of auditory nerve fiber stimulation for cochlear implants

    International Nuclear Information System (INIS)

    Evaluation of the electrical stimulation efficiency of various stimulating waveforms is an important issue for efficient neural stimulator design. Concerning the implantable micro devices design, it is also necessary to consider the feasibility of hardware implementation of the desired waveforms. In this paper, the charge, power and energy efficiency of four waveforms (i.e. square, rising ramp, triangular and rising ramp-decaying exponential) in various durations have been simulated and evaluated based on the computational model of the auditory nerve fibers. Moreover, for a fair comparison of their feasibility, a fully integrated current generator circuit has been developed so that the desired stimulating waveforms can be generated. The simulation results show that stimulation with the square waveforms is a proper choice in short and intermediate durations while the rising ramp-decaying exponential or triangular waveforms can be employed for long durations.

  19. Effects of Forest Disturbances on Forest Structural Parameters Retrieval from Lidar Waveform Data

    Science.gov (United States)

    Ranson, K, Lon; Sun, G.

    2011-01-01

    The effect of forest disturbance on the lidar waveform and the forest biomass estimation was demonstrated by model simulation. The results show that the correlation between stand biomass and the lidar waveform indices changes when the stand spatial structure changes due to disturbances rather than the natural succession. This has to be considered in developing algorithms for regional or global mapping of biomass from lidar waveform data.

  20. MIMO RADAR DETECTION IN COMPOUND GAUSSIAN CLUTTER USING ORTHOGONAL DISCRETE FREQUENCY CODING SPACE TIME WAVEFORM

    Directory of Open Access Journals (Sweden)

    B. Roja Reddy

    2014-08-01

    Full Text Available This paper proposes orthogonal Discrete Frequency Coding Space Time Waveforms (DFCSTW for Multiple Input and Multiple Output (MIMO radar detection in compound Gaussian clutter. The proposed orthogonal waveforms are designed considering the position and angle of the transmitting antenna when viewed from origin. These orthogonally optimized show good resolution in spikier clutter with Generalized Likelihood Ratio Test (GLRT detector. The simulation results show that this waveform provides better detection performance in spikier Clutter.

  1. Mimo Radar Detection in Compound Gaussian Clutter Using Orthogonal Discrete Frequency Coding Space Time Waveform

    Directory of Open Access Journals (Sweden)

    B. Roja Reddy

    2014-08-01

    Full Text Available This paper proposes orthogonal Discrete Frequency Coding Space Time Waveforms (DFCSTW for Multiple Input and Multiple Output (MIMO radar detection in compound Gaussian clutter. The proposed orthogonal waveforms are designed considering the position and angle of the transmitting antenna when viewed from origin. These orthogonally optimized show good resolution in spikier clutter with Generalized Likelihood Ratio Test (GLRT detector. The simulation results show that this waveform provides better detection performance in spikier Clutter

  2. ORTHOGONAL DISCRETE FREQUENCY CODING SPACE TIME WAVEFORM FOR MIMO RADAR DETECTION IN COMPOUND GAUSSIAN CLUTTER

    Directory of Open Access Journals (Sweden)

    B. Roja Reddy

    2016-01-01

    Full Text Available This paper proposes orthogonal Discrete Frequency Coding Space Time Waveforms (DFCSTW for Multiple Input and Multiple Output (MIMO radar detection in compound Gaussian clutter. The proposed orthogonal waveforms are designed considering the position and angle of the transmitting antenna when viewed from origin. These orthogonally optimized show good resolution in spikier clutter with Generalized Likelihood Ratio Test (GLRT detector. The simulation results show that this waveform provides better detection performance in spikier Clutter.

  3. Full waveform modelling and misfit calculation using the VERCE platform

    Science.gov (United States)

    Garth, Thomas; Spinuso, Alessandro; Casarotti, Emanuele; Magnoni, Federica; Krischner, Lion; Igel, Heiner; Schwichtenberg, Horst; Frank, Anton; Vilotte, Jean-Pierre; Rietbrock, Andreas

    2016-04-01

    In recent years the increasing resolution of seismic imagining by full waveform inversion has opened new research perspectives and practices. These methods rely on harnessing the computational power of large supercomputers and new storage capabilities, to run large parallel codes to simulate the seismic wave field in three-dimensional geological settings. The VERCE platform is designed to make these full waveform techniques accessible to a far wider spectrum of the seismological community. VERCE empowers a broad base of seismology researchers to harvest the new opportunities provided by well-established high-performance wave simulation codes such as SPECFEM3D. It meets a range of seismic research needs by eliminating the technical difficulties associated with using these codes, allowing users to focus on their research questions. VERCE delivers this power to seismologists through its science gateway, supporting wave simulation codes on each of the provided computing resources. Users can design their waveform simulation scenarios making use of a library of pre-loaded meshes and velocity models, and services for selecting earthquake focal mechanisms, seismic stations and recorded waveforms from existing catalogues, such as the GCMT catalogue, and FDSN data sources. They can also supply their own mesh, velocity model, earthquake catalogue and seismic observations. They can submit the simulations onto different computing resources, where VERCE provides codes that are tuned and supported for those resources. The simulations can currently be run on a range of European supercomputers in the PRACE network, including superMUC at LRZ, GALILEO at CINECA and on selected resources like Drachenfels at SCAI and within the EGI network. The gateway automates and looks after all these stages, but supplies seismologists with a provenance system that allows them to manage a large series of runs, review progress, and explore the results. The platform automates misfit analysis between

  4. Using Simulated Debates to Teach History of Engineering Advances

    Science.gov (United States)

    Reynolds, Terry S.

    1976-01-01

    Described is a technique for utilizing debates of past engineering controversies in the classroom as a means of teaching the history of engineering advances. Included is a bibliography for three debate topics relating to important controversies. (SL)

  5. Advances in Computational Social Science and Social Simulation

    OpenAIRE

    Miguel Quesada, Francisco J.; Amblard, Frédéric; Juan A. Barceló; Madella, Marco; Aguirre, Cristián; Ahrweiler, Petra; Aldred, Rachel; Ali Abbas, Syed Muhammad; Lopez Rojas, Edgar Alonso; Alonso Betanzos, Amparo; Alvarez Galvez, Javier; Andrighetto, Giulia; Antunes, Luis; Araghi, Yashar; Asatani, Kimitaka

    2014-01-01

    Aquesta conferència és la celebració conjunta de la "10th Artificial Economics Conference AE", la "10th Conference of the European Social Simulation Association ESSA" i la "1st Simulating the Past to Understand Human History SPUHH". Conferència organitzada pel Laboratory for Socio­-Historical Dynamics Simulation (LSDS-­UAB) de la Universitat Autònoma de Barcelona. Readers will find results of recent research on computational social science and social simulation economics, management, so...

  6. Vision and Displays for Military and Security Applications The Advanced Deployable Day/Night Simulation Project

    CERN Document Server

    Niall, Keith K

    2010-01-01

    Vision and Displays for Military and Security Applications presents recent advances in projection technologies and associated simulation technologies for military and security applications. Specifically, this book covers night vision simulation, semi-automated methods in photogrammetry, and the development and evaluation of high-resolution laser projection technologies for simulation. Topics covered include: advances in high-resolution projection, advances in image generation, geographic modeling, and LIDAR imaging, as well as human factors research for daylight simulation and for night vision devices. This title is ideal for optical engineers, simulator users and manufacturers, geomatics specialists, human factors researchers, and for engineers working with high-resolution display systems. It describes leading-edge methods for human factors research, and it describes the manufacture and evaluation of ultra-high resolution displays to provide unprecedented pixel density in visual simulation.

  7. Full Seismic Waveform Inversion for the Japanese Islands

    Science.gov (United States)

    Žukauskaitė, Saulė; Steptoe, Hamish; Fichtner, Andreas

    2015-04-01

    We present a seismic tomography model for the Japanese archipelago obtained using full waveform inversion and adjoint methods. A credible seismic velocity model is essential for the Japan region as a means to further our understanding of earthquake source mechanics by allowing for more accurate seismic source inversion, to benefit seismic hazard assessment as well as early warning systems, and to comprehend the complexity of the tectonic setting. The study area covers the Japanese islands, Taiwan, Korean peninsula, easternmost parts of China and Russia, Sakhalin and the majority of the Kuril Islands chain. The domain extends down into the mantle transition zone. We choose 58 earthquakes of magnitudes Mw5.0 - 6.9 distributed across the model domain as uniformly as possible. The data are obtained from several seismic networks in the area, namely F-net in Japan, BATS in Taiwan, South Korean National Earthquake Network and several stations from each China National Seismic Network, New China Digital Seismograph Network, Global Seismograph Network and Korean Seismic Network made available by IRIS Data Management Center. To facilitate full waveform inversion the forward problem is solved numerically using the spectral element method (SEM), which comes with the geometric flexibility of the finite-elements method and the accuracy of the spectral methods. Owing to the SEM and the advance in High Performance Computing we are able to perform numerical simulations of seismic waves in realistic 3D heterogeneous visco-elastic structures. Differences between the calculated and the real waveforms are quantified using the time-frequency misfits (Fichtner et al., 2008), which allow us to explore the temporal evolution of the frequency content of the data with no need to identify specific seismic phases. We use adjoint methods as an effective means to obtain sensitivity kernels and ultimately gradients, required for iterative gradient-based minimisation techniques. The obtained model

  8. Consistency of post-Newtonian waveforms with numerical relativity

    CERN Document Server

    Baker, J G; Kelly, B J; McWilliams, S T; Van Meter, J R; Baker, John G.; Centrella, Joan; Kelly, Bernard J.; Meter, James R. van; Williams, Sean T. Mc

    2006-01-01

    General relativity predicts the gravitational radiation signatures of mergers of compact binaries, such as coalescing binary black hole systems. Derivations of waveform predictions for such systems are required for optimal scientific analysis of observational gravitational wave data, and have so far been achieved primarily with the aid of the post-Newtonian (PN) approximation. The quality of this treatment is unclear, however, for the important late inspiral portion. We derive late-inspiral waveforms via a complementary approach, direct numerical simulation of Einstein's equations, which has recently matured sufficiently for such applications. We compare waveform phasing from simulations covering the last $\\sim 14$ cycles of gravitational radiation from an equal-mass binary system of non-spinning black holes with the corresponding 3PN and 3.5PN orbital phasing. We find agreement consistent with internal error estimates based on either approach at the level of one radian over $\\sim 10$ cycles. The result sugge...

  9. ALICES: advanced software engineering workshop for real-time simulators

    Energy Technology Data Exchange (ETDEWEB)

    Noel, A.; Rouault, G. [Tractebel, Brussels (Belgium)

    1997-12-01

    The ALICES software workshop is presently being applied for the development of a multifunctional simulator for Belgium`s Tihange-1 nuclear power unit. This will be the best validation for all the functions included in the tools. It is believed that ALICES will permit the development of quality realtime simulators at a significantly lower price.

  10. Waveform-dependent absorbing metasurfaces

    CERN Document Server

    Wakatsuchi, Hiroki; Rushton, Jeremiah J; Sievenpiper, Daniel F

    2014-01-01

    We present the first use of a waveform-dependent absorbing metasurface for high-power pulsed surface currents. The new type of nonlinear metasurface, composed of circuit elements including diodes, is capable of storing high power pulse energy to dissipate it between pulses, while allowing propagation of small signals. Interestingly, the absorbing performance varies for high power pulses but not for high power continuous waves (CWs), since the capacitors used are fully charged up. Thus, the waveform dependence enables us to distinguish various signal types (i.e. CW or pulse) even at the same frequency, which potentially creates new kinds of microwave technologies and applications.

  11. Development of Kinetic Mechanisms for Next-Generation Fuels and CFD Simulation of Advanced Combustion Engines

    Energy Technology Data Exchange (ETDEWEB)

    Pitz, William J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McNenly, Matt J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Whitesides, Russell [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mehl, Marco [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Killingsworth, Nick J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Westbrook, Charles K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-12-17

    Predictive chemical kinetic models are needed to represent next-generation fuel components and their mixtures with conventional gasoline and diesel fuels. These kinetic models will allow the prediction of the effect of alternative fuel blends in CFD simulations of advanced spark-ignition and compression-ignition engines. Enabled by kinetic models, CFD simulations can be used to optimize fuel formulations for advanced combustion engines so that maximum engine efficiency, fossil fuel displacement goals, and low pollutant emission goals can be achieved.

  12. Waveform-selective metasurfaces with normal waves at the same frequency

    CERN Document Server

    Wakatsuchi, Hiroki

    2015-01-01

    Waveform-selective metasurfaces, reported by Wakatsuchi et al. in 2014, have enabled us to distinguish different surface waves even at the same frequency in accordance with their waveforms or pulse widths. In this study we demonstrate that such new characteristics are applicable to controlling not only surface waves but also free-space waves normal to metasurfaces. Both simulation and measurement results show selective absorption or transmission for specific pulses at the same frequency. Thus the waveform selectivity is expected to create a wider range of new applications, for instance, waveform-selective antennas and wireless communications.

  13. Classification of Pulse Waveforms Using Edit Distance with Real Penalty

    Directory of Open Access Journals (Sweden)

    Zhang Dongyu

    2010-01-01

    Full Text Available Abstract Advances in sensor and signal processing techniques have provided effective tools for quantitative research in traditional Chinese pulse diagnosis (TCPD. Because of the inevitable intraclass variation of pulse patterns, the automatic classification of pulse waveforms has remained a difficult problem. In this paper, by referring to the edit distance with real penalty (ERP and the recent progress in -nearest neighbors (KNN classifiers, we propose two novel ERP-based KNN classifiers. Taking advantage of the metric property of ERP, we first develop an ERP-induced inner product and a Gaussian ERP kernel, then embed them into difference-weighted KNN classifiers, and finally develop two novel classifiers for pulse waveform classification. The experimental results show that the proposed classifiers are effective for accurate classification of pulse waveform.

  14. Advanced Algebraic Multigrid Solvers for Subsurface Flow Simulation

    KAUST Repository

    Chen, Meng-Huo

    2015-09-13

    In this research we are particularly interested in extending the robustness of multigrid solvers to encounter complex systems related to subsurface reservoir applications for flow problems in porous media. In many cases, the step for solving the pressure filed in subsurface flow simulation becomes a bottleneck for the performance of the simulator. For solving large sparse linear system arising from MPFA discretization, we choose multigrid methods as the linear solver. The possible difficulties and issues will be addressed and the corresponding remedies will be studied. As the multigrid methods are used as the linear solver, the simulator can be parallelized (although not trivial) and the high-resolution simulation become feasible, the ultimately goal which we desire to achieve.

  15. A Denoising Method for LiDAR Full-Waveform Data

    Directory of Open Access Journals (Sweden)

    Xudong Lai

    2015-01-01

    Full Text Available Decomposition of LiDAR full-waveform data can not only enhance the density and positioning accuracy of a point cloud, but also provide other useful parameters, such as pulse width, peak amplitude, and peak position which are important information for subsequent processing. Full-waveform data usually contain some random noises. Traditional filtering algorithms always cause distortion in the waveform. λ/μ filtering algorithm is based on Mean Shift method. It can smooth the signal iteratively and will not cause any distortion in the waveform. In this paper, an improved λ/μ filtering algorithm is proposed, and several experiments on both simulated waveform data and real waveform data are implemented to prove the effectiveness of the proposed algorithm.

  16. Development and implementation of advanced control methods for hybrid simulation

    OpenAIRE

    Kim, Hong

    2011-01-01

    Hybrid simulation is an effective way of testing structures that combines the benefits of a computational analysis and experimental testing techniques. Innovative structures consists of state-ofthe-art components and assemblages whose function as a system needs to be tested experimentally. Often times, these components and assemblages push the controller and other testing equipment to its limits. Performing hybrid simulation with the controller in displacement control mode does not always suf...

  17. Advance Reservation based DAG Application Scheduling Simulator for Grid Environment

    OpenAIRE

    Prajapati, Harshad B.; Shah, Vipul A.

    2012-01-01

    In the last decade, scheduling of Directed Acyclic Graph (DAG) application in the context of Grid environment has attracted attention of many researchers. However, deployment of Grid environment requires skills, efforts, budget, and time. Although various simulation toolkits or frameworks are available for simulating Grid environment, either they support different possible studies in Grid computing area or takes lot of efforts in molding them to make them suitable for scheduling of DAG applic...

  18. Advances in the Simulation-Based Analysis of Attitude Change

    OpenAIRE

    Voinea, Camelia Florela

    2012-01-01

    In this paper we provide an overview of the most relevant research work on the simulation of attitudes which evolved in the late 90’s and mainly after the year 2000. The general framework for the modeling, simulation and computational research on attitudes integrates research approaches (both fundamental and applicative) which combine theories from sociology, social psychology, social economics, political science, conflict theories, human-computer interaction areas with complexity theory, com...

  19. Phase Detector For Rectangular Waveforms

    Science.gov (United States)

    Dischert, Robert A.; Walter, James M.

    1993-01-01

    Phase detector for use with phase-locked-loops, servocontrol, and other electronic circuits designed to avoid disadvantages of other phase detectors. Used with both intermittent and continuous input signals. Circuit offers several advantages; reference signals continuous, burst of few pulses, or single pulse. Circuit "coasts" in absence of reference signal. Generates no steady-state output waveform at lock which makes filtering easier.

  20. Advanced visualization technology for terascale particle accelerator simulations

    OpenAIRE

    Ma, K-L; Schussman, G.; Wilson, B.; Ko, K.; Qiang, J.; Ryne, R.

    2002-01-01

    This paper presents two new hardware-assisted rendering techniques developed for interactive visualization of the terascale data generated from numerical modeling of nextgeneration accelerator designs. The first technique, based on a hybrid rendering approach, makes possible interactive exploration of large-scale particle data from particle beam dynamics modeling. The second technique, based on a compact texture-enhanced representation, exploits the advanced features of commodity graphic...

  1. Numerical Simulations and Optimisation in Forming of Advanced Materials

    Science.gov (United States)

    Huétink, J.

    2007-04-01

    With the introduction of new materials as high strength steels, metastable steels and fiber reinforce composites, the need for advanced physically valid constitutive models arises. A biaxial test equipment is developed and applied for the determination of material data as well as for validation of material models. An adaptive through- thickness integration scheme for plate elements is developed, which improves the accuracy of spring back prediction at minimal costs. An optimization strategy is proposed that assists an engineer to model an optimization problem.

  2. Designing waveforms for temporal encoding using a frequency sampling method

    DEFF Research Database (Denmark)

    Gran, Fredrik; Jensen, Jørgen Arendt

    2007-01-01

    for the linear frequency modulated signal) were tested for both waveforms in simulation with respect to the Doppler frequency shift occurring when probing moving objects. It was concluded that the Doppler effect of moving targets does not significantly degrade the filtered output. Finally, in vivo measurements...

  3. Advancements on the simulation of the micro injection moulding process

    DEFF Research Database (Denmark)

    Marhöfer, David Maximilian; Tosello, Guido; Hansen, Hans Nørgaard;

    2013-01-01

    Process simulations are applied in micro injection molding with the same purpose as in conventional injection molding: aiming at optimization and support of the design of mold, inserts, plastic products, and the process itself. Available software packages are however not well suited for micro...... injection molding, because they are developed for macro plastic parts and they are therefore limited in the capability of modeling the polymer flow in micro cavities properly. However, new opportunities for improved accuracy have opened up due to current developments of the simulation technology. Hence, new...... strategies and aspects for comprehensive simulation models which provide more precise results for micro injection molding are discussed. Modeling and meshing recommendations are presented, leading to a multi-scale mesh of all relevant units in the injection molding process. The implementation of the process...

  4. Advance in research on aerosol deposition simulation methods

    International Nuclear Information System (INIS)

    A comprehensive analysis of the health effects of inhaled toxic aerosols requires exact data on airway deposition. A knowledge of the effect of inhaled drugs is essential to the optimization of aerosol drug delivery. Sophisticated analytical deposition models can be used for the computation of total, regional and generation specific deposition efficiencies. The continuously enhancing computer seem to allow us to study the particle transport and deposition in more and more realistic airway geometries with the help of computational fluid dynamics (CFD) simulation method. In this article, the trends in aerosol deposition models and lung models, and the methods for achievement of deposition simulations are also reviewed. (authors)

  5. Advancing Simulation Reusability - Report on NATO MSG-042 Findings

    NARCIS (Netherlands)

    Reif, B.M.; Wharton, W.D.; Gonzalez-Godoy, S.; McGlynn, L.; San Jose, A.; Elliot, R.; Franzen, S.; Lecinq, X.; Huiskamp, W.; Edmondson, D.

    2006-01-01

    In many cases, the training and decision support needs of military users are urgent; operations can not wait and missions have to be accomplished. Simulators, wargames scenarios and experiments should be ready 'yesterday'. New kinds of operations, environments, tactics, equipment and force configura

  6. Advancing Simulation Reusability - Report on NATO MSG-042 Findings

    NARCIS (Netherlands)

    Reif, B.M.; Wharton, W.D.; Gonzalez-Godoy, S.; McGlynn, L.; San Jose, A.; Elliot, R.; Franzen, S.; Lecenq, X.; Huiskamp, W.; Edmondson, D.

    2007-01-01

    In many cases, the training and decision support needs of military users are urgent; operations cannot wait and missions have to be accomplished. Simulators, wargames scenarios and experiments should be ready 'yesterday'. New kinds of operations, environments, tactics, equipment and force configurat

  7. Recent Advances in Underwater Acoustic Modelling and Simulation

    Science.gov (United States)

    ETTER, P. C.

    2001-02-01

    A comprehensive review of international developments in underwater acoustic modelling is used to construct an updated technology baseline containing 107 propagation models, 16 noise models, 17 reverberation models and 25 sonar performance models. This updated technology baseline represents a 30% increase over a previous baseline published in 1996. When executed in higher-level simulations, these models can generate predictive and diagnostic outputs that are useful to acoustical oceanographers or sonar technologists in the analysis of complex systems operating in the undersea environment. Recent modelling developments described in the technical literature suggest two principal areas of application: low-frequency, inverse acoustics in deep water; and high-frequency, bottom-interacting acoustics in coastal regions. Rapid changes in global geopolitics have opened new avenues for collaboration, thereby facilitating the transfer of modelling and simulation technologies among members of the international community. This accelerated technology transfer has created new imperatives for international standards in modelling and simulation architectures. National and international activities to promote interoperability among modelling and simulation efforts in government, industry and academia are reviewed and discussed.

  8. Advanced Simulation and Computing Co-Design Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Ang, James A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hoang, Thuc T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kelly, Suzanne M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); McPherson, Allen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Neely, Rob [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    This ASC Co-design Strategy lays out the full continuum and components of the co-design process, based on what we have experienced thus far and what we wish to do more in the future to meet the program’s mission of providing high performance computing (HPC) and simulation capabilities for NNSA to carry out its stockpile stewardship responsibility.

  9. An MSK Waveform for Radar Applications

    Science.gov (United States)

    Quirk, Kevin J.; Srinivasan, Meera

    2009-01-01

    We introduce a minimum shift keying (MSK) waveform developed for use in radar applications. This waveform is characterized in terms of its spectrum, autocorrelation, and ambiguity function, and is compared with the conventionally used bi-phase coded (BPC) radar signal. It is shown that the MSK waveform has several advantages when compared with the BPC waveform, and is a better candidate for deep-space radar imaging systems such as NASA's Goldstone Solar System Radar.

  10. Generating nonlinear FM chirp waveforms for radar.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2006-09-01

    Nonlinear FM waveforms offer a radar matched filter output with inherently low range sidelobes. This yields a 1-2 dB advantage in Signal-to-Noise Ratio over the output of a Linear FM waveform with equivalent sidelobe filtering. This report presents design and implementation techniques for Nonlinear FM waveforms.

  11. Simulation for Supporting Scale-Up of a Fluidized Bed Reactor for Advanced Water Oxidation

    OpenAIRE

    Farhana Tisa; Abdul Aziz Abdul Raman; Wan Mohd Ashri Wan Daud

    2014-01-01

    Simulation of fluidized bed reactor (FBR) was accomplished for treating wastewater using Fenton reaction, which is an advanced oxidation process (AOP). The simulation was performed to determine characteristics of FBR performance, concentration profile of the contaminants, and various prominent hydrodynamic properties (e.g., Reynolds number, velocity, and pressure) in the reactor. Simulation was implemented for 2.8 L working volume using hydrodynamic correlations, continuous equation, and simp...

  12. Interim Service ISDN Satellite (ISIS) simulator development for advanced satellite designs and experiments

    Science.gov (United States)

    Pepin, Gerard R.

    1992-01-01

    The simulation development associated with the network models of both the Interim Service Integrated Services Digital Network (ISDN) Satellite (ISIS) and the Full Service ISDN Satellite (FSIS) architectures is documented. The ISIS Network Model design represents satellite systems like the Advanced Communications Technology Satellite (ACTS) orbiting switch. The FSIS architecture, the ultimate aim of this element of the Satellite Communications Applications Research (SCAR) Program, moves all control and switching functions on-board the next generation ISDN communications satellite. The technical and operational parameters for the advanced ISDN communications satellite design will be obtained from the simulation of ISIS and FSIS engineering software models for their major subsystems. Discrete event simulation experiments will be performed with these models using various traffic scenarios, design parameters, and operational procedures. The data from these simulations will be used to determine the engineering parameters for the advanced ISDN communications satellite.

  13. Reflection seismic waveform tomography of physical modelling data

    Science.gov (United States)

    Rao, Y.; Wang, Y.; Zhang, Z. D.; Ning, Y. C.; Chen, X. H.; Li, J. Y.

    2016-04-01

    Waveform tomography is commonly tested using numerically generated synthetic seismic data, before the method is applied to field seismic data. However, there are often noticeable differences between idealized synthetic data and real field data, and many factors in the field data, such as noise, irregular source/receiver geometry, affect the inversion solutions. For exploring the potential of reflection seismic waveform tomography, we presented a more realistic test than the synthetic data test, by applying it to physical modelling data, to reconstruct a laboratorial model with complex velocity variation. First, we provided a formulation of the perfectly matched layer absorbing boundary condition, associated with the second-order acoustic wave equation, in order to suppress artificial reflections from subsurface model boundaries in seismic waveform simulation and tomography. Then, we demonstrated the successful implementation of a layer-striping inversion scheme applicable to reflection seismic waveform tomography. Finally, we confirmed the effectiveness of frequency grouping, rather than a single frequency at each iteration, a strategy specifically for the frequency-domain waveform tomography.

  14. Use of simulators for validation of advanced plant monitoring systems

    International Nuclear Information System (INIS)

    This paper describes how the full-scope nuclear power plant simulator of Doel (Belgium) was used to assess Situation Awareness for the validation of a process monitoring and supervision system, named DIMOS. The method (derived from a method originally developed for the aerospace industry) has been adapted and applied to compare the efficiency of two versions of the monitoring system: Alarm-masking and non alarm-masking versions of DIMOS have been analysed in their ability to support Situation Awareness, to improve performance and to fulfil the satisfaction of operators. Both normal power plant operating conditions and abnormal operating conditions were simulated and a large number of power plant operators were involved in the evaluation. The paper focuses on the rationale behind the 'Situation Awareness' evaluation, the experiment environment and the results regarding the added value of the alarm masking version of the monitoring system. (author)

  15. Use of advanced simulations in fuel performance codes

    International Nuclear Information System (INIS)

    The simulation of the cylindrical fuel rod behaviour in a reactor or a storage pool for spent fuel requires a fuel performance code. Such tool solves the equations for the heat transfer, the stresses and strains in fuel and cladding, the evolution of several isotopes and the behaviour of various fission products in the fuel rod. The main equations along with their limitations are briefly described. The current approaches adopted for overcoming these limitations and the perspectives are also outlined. (author)

  16. Advanced vectorial simulation of VCSELs with nano structures invited paper

    DEFF Research Database (Denmark)

    Chung, Il-Sug; Mørk, Jesper

    2009-01-01

    The single-mode properties and design issues of three vertical-cavity surface-emitting laser (VCSEL) structures incorporating nano structures are rigorously investigated. Nano structuring enables to deliver selective pumping or loss to the fundamental mode as well as stabilizing the output...... polarization state. Comparison of three vectorial simulation methods reveals that the modal expansion method is suitable for treating the nano structured VCSEL designs....

  17. Advanced Dynamically Adaptive Algorithms for Stochastic Simulations on Extreme Scales

    Energy Technology Data Exchange (ETDEWEB)

    Xiu, Dongbin [Purdue Univ., West Lafayette, IN (United States)

    2016-06-21

    The focus of the project is the development of mathematical methods and high-performance com- putational tools for stochastic simulations, with a particular emphasis on computations on extreme scales. The core of the project revolves around the design of highly e cient and scalable numer- ical algorithms that can adaptively and accurately, in high dimensional spaces, resolve stochastic problems with limited smoothness, even containing discontinuities.

  18. Simulation of an advanced techniques of ion propulsion Rocket system

    Science.gov (United States)

    Bakkiyaraj, R.

    2016-07-01

    The ion propulsion rocket system is expected to become popular with the development of Deuterium,Argon gas and Hexagonal shape Magneto hydrodynamic(MHD) techniques because of the stimulation indirectly generated the power from ionization chamber,design of thrust range is 1.2 N with 40 KW of electric power and high efficiency.The proposed work is the study of MHD power generation through ionization level of Deuterium gas and combination of two gaseous ions(Deuterium gas ions + Argon gas ions) at acceleration stage.IPR consists of three parts 1.Hexagonal shape MHD based power generator through ionization chamber 2.ion accelerator 3.Exhaust of Nozzle.Initially the required energy around 1312 KJ/mol is carrying out the purpose of deuterium gas which is changed to ionization level.The ionized Deuterium gas comes out from RF ionization chamber to nozzle through MHD generator with enhanced velocity then after voltage is generated across the two pairs of electrode in MHD.it will produce thrust value with the help of mixing of Deuterium ion and Argon ion at acceleration position.The simulation of the IPR system has been carried out by MATLAB.By comparing the simulation results with the theoretical and previous results,if reaches that the proposed method is achieved of thrust value with 40KW power for simulating the IPR system.

  19. Fast and accurate prediction of numerical relativity waveforms from binary black hole mergers using surrogate models

    CERN Document Server

    Blackman, Jonathan; Galley, Chad R; Szilagyi, Bela; Scheel, Mark A; Tiglio, Manuel; Hemberger, Daniel A

    2015-01-01

    Simulating a binary black hole coalescence by solving Einstein's equations is computationally expensive, requiring days to months of supercomputing time. In this paper, we construct an accurate and fast-to-evaluate surrogate model for numerical relativity (NR) waveforms from non-spinning binary black hole coalescences with mass ratios from $1$ to $10$ and durations corresponding to about $15$ orbits before merger. Our surrogate, which is built using reduced order modeling techniques, is distinct from traditional modeling efforts. We find that the full multi-mode surrogate model agrees with waveforms generated by NR to within the numerical error of the NR code. In particular, we show that our modeling strategy produces surrogates which can correctly predict NR waveforms that were {\\em not} used for the surrogate's training. For all practical purposes, then, the surrogate waveform model is equivalent to the high-accuracy, large-scale simulation waveform but can be evaluated in a millisecond to a second dependin...

  20. Advanced visualization technology for terascale particle accelerator simulations

    International Nuclear Information System (INIS)

    This paper presents two new hardware-assisted rendering techniques developed for interactive visualization of the terascale data generated from numerical modeling of next generation accelerator designs. The first technique, based on a hybrid rendering approach, makes possible interactive exploration of large-scale particle data from particle beam dynamics modeling. The second technique, based on a compact texture-enhanced representation, exploits the advanced features of commodity graphics cards to achieve perceptually effective visualization of the very dense and complex electromagnetic fields produced from the modeling of reflection and transmission properties of open structures in an accelerator design. Because of the collaborative nature of the overall accelerator modeling project, the visualization technology developed is for both desktop and remote visualization settings. We have tested the techniques using both time varying particle data sets containing up to one billion particle s per time step and electromagnetic field data sets with millions of mesh elements

  1. An advanced leakage scheme for neutrino treatment in astrophysical simulations

    CERN Document Server

    Perego, Albino; Käppeli, Roger

    2015-01-01

    We present an Advanced Spectral Leakage (ASL) scheme to model neutrinos in the context of core-collapse supernovae and compact binary mergers. Based on previous gray leakage schemes, the ASL scheme computes the neutrino cooling rates by interpolating local production and diffusion rates (relevant in optically thin and thick regimes, respectively), separately for discretized values of the neutrino energy. Neutrino trapped components are also modeled, based on equilibrium and timescale arguments. The better accuracy achieved by the spectral treatment allows a more reliable computation of neutrino heating rates in optically thin conditions. The scheme has been calibrated and tested against Boltzmann transport in the context of Newtonian spherically symmetric models of core-collapse supernovae. ASL shows a very good qualitative and a partial quantitative agreement, for key quantities from collapse to a few hundreds of milliseconds after core bounce. We have proved the adaptability and flexibility of our ASL schem...

  2. Computational modeling, optimization and manufacturing simulation of advanced engineering materials

    CERN Document Server

    2016-01-01

    This volume presents recent research work focused in the development of adequate theoretical and numerical formulations to describe the behavior of advanced engineering materials.  Particular emphasis is devoted to applications in the fields of biological tissues, phase changing and porous materials, polymers and to micro/nano scale modeling. Sensitivity analysis, gradient and non-gradient based optimization procedures are involved in many of the chapters, aiming at the solution of constitutive inverse problems and parameter identification. All these relevant topics are exposed by experienced international and inter institutional research teams resulting in a high level compilation. The book is a valuable research reference for scientists, senior undergraduate and graduate students, as well as for engineers acting in the area of computational material modeling.

  3. Approaching the Post-Newtonian Regime with Numerical Relativity: A Compact-Object Binary Simulation Spanning 350 Gravitational-Wave Cycles.

    Science.gov (United States)

    Szilágyi, Béla; Blackman, Jonathan; Buonanno, Alessandra; Taracchini, Andrea; Pfeiffer, Harald P; Scheel, Mark A; Chu, Tony; Kidder, Lawrence E; Pan, Yi

    2015-07-17

    We present the first numerical-relativity simulation of a compact-object binary whose gravitational waveform is long enough to cover the entire frequency band of advanced gravitational-wave detectors, such as LIGO, Virgo, and KAGRA, for mass ratio 7 and total mass as low as 45.5M_{⊙}. We find that effective-one-body models, either uncalibrated or calibrated against substantially shorter numerical-relativity waveforms at smaller mass ratios, reproduce our new waveform remarkably well, with a negligible loss in detection rate due to modeling error. In contrast, post-Newtonian inspiral waveforms and existing calibrated phenomenological inspiral-merger-ringdown waveforms display greater disagreement with our new simulation. The disagreement varies substantially depending on the specific post-Newtonian approximant used. PMID:26230780

  4. Advanced Simulation Technology to Design Etching Process on CMOS Devices

    Science.gov (United States)

    Kuboi, Nobuyuki

    2015-09-01

    Prediction and control of plasma-induced damage is needed to mass-produce high performance CMOS devices. In particular, side-wall (SW) etching with low damage is a key process for the next generation of MOSFETs and FinFETs. To predict and control the damage, we have developed a SiN etching simulation technique for CHxFy/Ar/O2 plasma processes using a three-dimensional (3D) voxel model. This model includes new concepts for the gas transportation in the pattern, detailed surface reactions on the SiN reactive layer divided into several thin slabs and C-F polymer layer dependent on the H/N ratio, and use of ``smart voxels''. We successfully predicted the etching properties such as the etch rate, polymer layer thickness, and selectivity for Si, SiO2, and SiN films along with process variations and demonstrated the 3D damage distribution time-dependently during SW etching on MOSFETs and FinFETs. We confirmed that a large amount of Si damage was caused in the source/drain region with the passage of time in spite of the existing SiO2 layer of 15 nm in the over etch step and the Si fin having been directly damaged by a large amount of high energy H during the removal step of the parasitic fin spacer leading to Si fin damage to a depth of 14 to 18 nm. By analyzing the results of these simulations and our previous simulations, we found that it is important to carefully control the dose of high energy H, incident energy of H, polymer layer thickness, and over-etch time considering the effects of the pattern structure, chamber-wall condition, and wafer open area ratio. In collaboration with Masanaga Fukasawa and Tetsuya Tatsumi, Sony Corporation. We thank Mr. T. Shigetoshi and Mr. T. Kinoshita of Sony Corporation for their assistance with the experiments.

  5. Electric and plug-in hybrid vehicles advanced simulation methodologies

    CERN Document Server

    Varga, Bogdan Ovidiu; Moldovanu, Dan; Iclodean, Calin

    2015-01-01

    This book is designed as an interdisciplinary platform for specialists working in electric and plug-in hybrid electric vehicles powertrain design and development, and for scientists who want to get access to information related to electric and hybrid vehicle energy management, efficiency and control. The book presents the methodology of simulation that allows the specialist to evaluate electric and hybrid vehicle powertrain energy flow, efficiency, range and consumption. The mathematics behind each electric and hybrid vehicle component is explained and for each specific vehicle the powertrain

  6. Silicon and beyond advanced device models and circuit simulators

    CERN Document Server

    Shur, Michael S

    2000-01-01

    The steady downscaling of device-feature size combined with a rapid increase in circuit complexity as well as the introduction of new device concepts based on non-silicon-material systems poses great challenges for device and circuit designers. One of the major tasks is the development of new and improved device models needed for accurate device and circuit design. Another task is the development of new circuit-simulation tools to handle very large and complex circuits. This book addresses both these issues with up-to-date reviews written by leading experts in the field.The first three chapter

  7. Microwave Processing of Simulated Advanced Nuclear Fuel Pellets

    International Nuclear Information System (INIS)

    Throughout the three-year project funded by the Department of Energy (DOE) and lead by Virginia Tech (VT), project tasks were modified by consensus to fit the changing needs of the DOE with respect to developing new inert matrix fuel processing techniques. The focus throughout the project was on the use of microwave energy to sinter fully stabilized zirconia pellets using microwave energy and to evaluate the effectiveness of techniques that were developed. Additionally, the research team was to propose fundamental concepts as to processing radioactive fuels based on the effectiveness of the microwave process in sintering the simulated matrix material.

  8. Recent Advances in the Numerical Simulations of Binary Black Holes

    CERN Document Server

    Marronetti, Pedro

    2011-01-01

    Since the breakthrough papers from 2005/2006, the field of numerical relativity has experienced a growth spurt that took the two-body problem in general relativity from the category of "really-hard-problems" to the realm of "things-we-know-how-to-do". Simulations of binary black holes in circular orbits, the holy grail of numerical relativity, are now tractable problems that lead to some of the most spectacular results in general relativity in recent years. We cover here some of the latest achievements and highlight the field's next challenges.

  9. Waveform digitization utilizing switched-capacitor arrays

    International Nuclear Information System (INIS)

    Compared with traditional waveform digitization with flash-ADCs, waveform digitization with switched-capacitor arrays (SCAs) is able to achieve the sampling speed above 1 GS/s without degrading the analog to digital conversion precision significantly. In this paper, we present the implementation of a fast waveform digitization system with the use of SCAs, and evaluate its performance of waveform digitization and the waveform timing. At about 5 GS/s, the dynamic input range of the digitizer is about 66 dB, and its timing precision is about 20 ps (RMS). (authors)

  10. Why Waveform Correlation Sometimes Fails

    Science.gov (United States)

    Carmichael, J.

    2015-12-01

    Waveform correlation detectors used in explosion monitoring scan noisy geophysical data to test two competing hypotheses: either (1) an amplitude-scaled version of a template waveform is present, or, (2) no signal is present at all. In reality, geophysical wavefields that are monitored for explosion signatures include waveforms produced by non-target sources that are partially correlated with the waveform template. Such signals can falsely trigger correlation detectors, particularly at low thresholds required to monitor for smaller target explosions. This challenge is particularly formidable when monitoring known test sites for seismic disturbances, since uncatalogued natural seismicity is (generally) more prevalent at lower magnitudes, and could be mistaken for small explosions. To address these challenges, we identify real examples in which correlation detectors targeting explosions falsely trigger on both site-proximal earthquakes (Figure 1, below) and microseismic "noise". Motivated by these examples, we quantify performance loss when applying these detectors, and re-evaluate the correlation-detector's hypothesis test. We thereby derive new detectors from more general hypotheses that admit unknown background seismicity, and apply these to real data. From our treatment, we derive "rules of thumb'' for proper template and threshold selection in heavily cluttered signal environments. Last, we answer the question "what is the probability of falsely detecting an earthquake collocated at a test site?", using correlation detectors that include explosion-triggered templates. Figure Top: An eight-channel data stream (black) recorded from an earthquake near a mine. Red markers indicate a detection. Middle: The correlation statistic computed by scanning the template against the data stream at top. The red line indicates the threshold for event declaration, determined by a false-alarm on noise probability constraint, as computed from the signal-absent distribution using

  11. Advances in comprehensive gyrokinetic simulations of transport in tokamaks

    International Nuclear Information System (INIS)

    A continuum global gyrokinetic code GYRO has been developed to comprehensively simulate core turbulent transport in actual experimental profiles and enable direct quantitative comparisons to the experimental transport flows. GYRO not only treats the now standard ion temperature gradient (ITG) mode turbulence, but also treats trapped and passing electrons with collisions and finite β, equilibrium ExB shear stabilization, and all in real tokamak geometry. Most importantly the code operates at finite relative gyroradius (ρ*) so as to treat the profile shear stabilization and nonlocal effects which can break gyroBohm scaling. The code operates in either a cyclic flux-tube limit (which allows only gyroBohm scaling) or globally with physical profile variation. Bohm scaling of DIII-D L-mode has been simulated with power flows matching experiment within error bars on the ion temperature gradient. Mechanisms for broken gyroBohm scaling, neoclassical ion flows embedded in turbulence, turbulent dynamos and profile corrugations, are illustrated. (author)

  12. Simulation models and designs for advanced Fischer-Tropsch technology

    Energy Technology Data Exchange (ETDEWEB)

    Choi, G.N.; Kramer, S.J.; Tam, S.S. [Bechtel Corp., San Francisco, CA (United States)

    1995-12-31

    Process designs and economics were developed for three grass-roots indirect Fischer-Tropsch coal liquefaction facilities. A baseline and an alternate upgrading design were developed for a mine-mouth plant located in southern Illinois using Illinois No. 6 coal, and one for a mine-mouth plane located in Wyoming using Power River Basin coal. The alternate design used close-coupled ZSM-5 reactors to upgrade the vapor stream leaving the Fischer-Tropsch reactor. ASPEN process simulation models were developed for all three designs. These results have been reported previously. In this study, the ASPEN process simulation model was enhanced to improve the vapor/liquid equilibrium calculations for the products leaving the slurry bed Fischer-Tropsch reactors. This significantly improved the predictions for the alternate ZSM-5 upgrading design. Another model was developed for the Wyoming coal case using ZSM-5 upgrading of the Fischer-Tropsch reactor vapors. To date, this is the best indirect coal liquefaction case. Sensitivity studies showed that additional cost reductions are possible.

  13. NATO Advanced Study Institute on Advances in the Computer Simulations of Liquid Crystals

    CERN Document Server

    Zannoni, Claudio

    2000-01-01

    Computer simulations provide an essential set of tools for understanding the macroscopic properties of liquid crystals and of their phase transitions in terms of molecular models. While simulations of liquid crystals are based on the same general Monte Carlo and molecular dynamics techniques as are used for other fluids, they present a number of specific problems and peculiarities connected to the intrinsic properties of these mesophases. The field of computer simulations of anisotropic fluids is interdisciplinary and is evolving very rapidly. The present volume covers a variety of techniques and model systems, from lattices to hard particle and Gay-Berne to atomistic, for thermotropics, lyotropics, and some biologically interesting liquid crystals. Contributions are written by an excellent panel of international lecturers and provides a timely account of the techniques and problems in the field.

  14. Phenomenological gravitational waveforms from spinning coalescing binaries

    CERN Document Server

    Sturani, R; Cadonati, L; Guidi, G M; Healy, J; Shoemaker, D; Vicere', A

    2010-01-01

    An accurate knowledge of the coalescing binary gravitational waveform is crucial for match filtering techniques, which are currently used in the observational searches performed by the LIGO-Virgo collaboration. Following an earlier paper by the same authors we expose the construction of analytical phenomenological waveforms describing the signal sourced by generically spinning binary systems. The gap between the initial inspiral part of the waveform, described by spin-Taylor approximants, and its final ring-down part, described by damped exponentials, is bridged by a phenomenological phase calibrated by comparison with the dominant spherical harmonic mode of a set of waveforms including both numerical and phenomenological waveforms of a different type. All waveforms considered describe equal mass systems with dimension-less spin magnitudes equal to 0.6. The noise-weighted overlap integral between numerical and phenomenological waveforms ranges between 0.93 and 0.98 for a wide span of mass values.

  15. Automated Analysis, Classification, and Display of Waveforms

    Science.gov (United States)

    Kwan, Chiman; Xu, Roger; Mayhew, David; Zhang, Frank; Zide, Alan; Bonggren, Jeff

    2004-01-01

    A computer program partly automates the analysis, classification, and display of waveforms represented by digital samples. In the original application for which the program was developed, the raw waveform data to be analyzed by the program are acquired from space-shuttle auxiliary power units (APUs) at a sampling rate of 100 Hz. The program could also be modified for application to other waveforms -- for example, electrocardiograms. The program begins by performing principal-component analysis (PCA) of 50 normal-mode APU waveforms. Each waveform is segmented. A covariance matrix is formed by use of the segmented waveforms. Three eigenvectors corresponding to three principal components are calculated. To generate features, each waveform is then projected onto the eigenvectors. These features are displayed on a three-dimensional diagram, facilitating the visualization of the trend of APU operations.

  16. Advanced Simulation of Electron Heat Transport in Fusion Plasmas

    International Nuclear Information System (INIS)

    Electron transport in burning plasmas is more important since fusion products first heat electrons. First-principles simulations of electron turbulence are much more challenging due to the multi-scale dynamics of the electron turbulence, and have been made possible by close collaborations between plasma physicists and computational scientists. The GTC simulations of collisionless trapped electron mode (CTEM) turbulence show that the electron heat transport exhibits a gradual transition from Bohm to gyroBohm scaling when the device size is increased. The deviation from the gyroBohm scaling can be induced by large turbulence eddies, turbulence spreading, and non-diffusive transport processes. Analysis of radial correlation function shows that CTEM turbulence eddies are predominantly microscopic but with a significant tail in the mesoscale. A comprehensive analysis of kinetic and fluid time scales shows that zonal flow shearing is the dominant decorrelation mechanism. The mesoscale eddies result from a dynamical process of linear streamers breaking by zonal flows and merging of microscopic eddies. The radial profile of the electron heat conductivity only follows the profile of fluctuation intensity on a global scale, whereas the ion transport tracks more sensitively the local fluctuation intensity. This suggests the existence of a nondiffusive component in the electron heat flux, which arises from the ballistic radial E x B drift of trapped electrons due to a combination of the presence of mesoscale eddies and the weak de-tuning of the toroidal precessional resonance that drives the CTEM instability. On the other hand, the ion radial excursion is not affected by the mesoscale eddies due to a parallel decorrelation, which is not operational for the trapped electrons because of a bounce averaging process associated with the electron fast motion along magnetic field lines. The presence of the nondiffusive component raises question on the applicability of the usual

  17. Advanced simulation of electron heat transport in fusion plasmas

    International Nuclear Information System (INIS)

    Electron transport in burning plasmas is more important since fusion products first heat electrons. First-principles simulations of electron turbulence are much more challenging due to the multi-scale dynamics of the electron turbulence, and have been made possible by close collaborations between plasma physicists and computational scientists. The GTC simulations of collisionless trapped electron mode (CTEM) turbulence show that the electron heat transport exhibits a gradual transition from Bohm to gyroBohm scaling when the device size is increased. The deviation from the gyroBohm scaling can be induced by large turbulence eddies, turbulence spreading, and non-diffusive transport processes. Analysis of radial correlation function shows that CTEM turbulence eddies are predominantly microscopic but with a significant tail in the mesoscale. A comprehensive analysis of kinetic and fluid time scales shows that zonal flow shearing is the dominant decorrelation mechanism. The mesoscale eddies result from a dynamical process of linear streamers breaking by zonal flows and merging of microscopic eddies. The radial profile of the electron heat conductivity only follows the profile of fluctuation intensity on a global scale, whereas the ion transport tracks more sensitively the local fluctuation intensity. This suggests the existence of a nondiffusive component in the electron heat flux, which arises from the ballistic radial E X B drift of trapped electrons due to a combination of the presence of mesoscale eddies and the weak de-tuning of the toroidal precessional resonance that drives the CTEM instability. On the other hand, the ion radial excursion is not affected by the mesoscale eddies due to a parallel decorrelation, which is not operational for the trapped electrons because of a bounce averaging process associated with the electron fast motion along magnetic field lines. The presence of the nondiffusive component raises question on the applicability of the usual

  18. Advanced simulation of damage of reinforced concrete structures under impact

    International Nuclear Information System (INIS)

    The efficiency of the discrete element method for studying the fracture of heterogeneous media has been demonstrated, but it is limited by the size of the computational model. A coupling between the discrete element and the finite element methods is proposed to handle the simulation of impacts on large structures. The structure is split into sub-domains in each of which the method of analysis is adapted to optimise the modelling of the structure behaviour under impact. The DEM takes naturally into account the discontinuities and is used to model the media in the impact zone. The remaining structure is modelled by the FEM. Proposed combined DE/FE algorithm is implemented in the Europlexus fast dynamics software and parallelized with MPI formalism. The efficiency of the Europlexus multi-domain MPI parallel version is tested. (authors)

  19. Advanced wellbore thermal simulator GEOTEMP2 user manual

    Energy Technology Data Exchange (ETDEWEB)

    Mondy, L.A.; Duda, L.E.

    1984-11-01

    GEOTEMP2 is a wellbore thermal simulator computer code designed for geothermal drilling and production applications. The code treats natural and forced convection and conduction within the wellbore and heat conduction within the surrounding rock matrix. A variety of well operations can be modeled including injection, production, forward, and reverse circulation with gas or liquid, gas or liquid drilling, and two-phase steam injection and production. Well completion with several different casing sizes and cement intervals can be modeled. The code allows variables suchas flow rate to change with time enabling a realistic treatment of well operations. This user manual describes the input required to properly operate the code. Ten sample problems are included which illustrate all the code options. Complete listings of the code and the output of each sample problem are provided.

  20. Using CONFIG for Simulation of Operation of Water Recovery Subsystems for Advanced Control Software Evaluation

    Science.gov (United States)

    Malin, Jane T.; Flores, Luis; Fleming, Land; Throop, Daiv

    2002-01-01

    A hybrid discrete/continuous simulation tool, CONFIG, has been developed to support evaluation of the operability life support systems. CON FIG simulates operations scenarios in which flows and pressures change continuously while system reconfigurations occur as discrete events. In simulations, intelligent control software can interact dynamically with hardware system models. CONFIG simulations have been used to evaluate control software and intelligent agents for automating life support systems operations. A CON FIG model of an advanced biological water recovery system has been developed to interact with intelligent control software that is being used in a water system test at NASA Johnson Space Center

  1. The role of advanced calculation and simulation tools in the evolution of fuel

    International Nuclear Information System (INIS)

    This article is focused on the role of the advanced calculation/simulation tools on the development of the fuel designs as well as in the assessment of the effect of the changes in the operation. With this purpose, the article describes and shows some examples of the use by ENUSA of some of these tools in the fuel engineering. To conclude, the future on the evolution of the advanced tools is also presented. (Author)

  2. Gravitational waveforms from binary neutron star mergers with high-order WENO schemes in numerical relativity

    CERN Document Server

    Bernuzzi, Sebastiano

    2016-01-01

    The theoretical modeling of gravitational waveforms from binary neutron star mergers requires precise numerical relativity simulations. Assessing convergence of the numerical data and building the error budget is currently challenging due to the low accuracy of general-relativistic hydrodynamics schemes and to the grid resolutions that can be employed in (3+1)-dimensional simulations. In this work, we explore the use of high-order weighted-essentially-non-oscillatory (WENO) schemes in neutron star merger simulations and investigate the accuracy of the waveforms obtained with such methods. We find that high-order WENO schemes can be robustly employed for simulating the inspiral-merger phase and they significantly improve the assessment of the waveform's error budget with respect to finite-volume methods. High-order WENO schemes can be thus efficiently used for high-quality waveforms production, also in future large-scale investigations of the binary parameter space.

  3. Design and Test of Advanced Thermal Simulators for an Alkali Metal-Cooled Reactor Simulator

    Science.gov (United States)

    Garber, Anne E.; Dickens, Ricky E.

    2011-01-01

    The Early Flight Fission Test Facility (EFF-TF) at NASA Marshall Space Flight Center (MSFC) has as one of its primary missions the development and testing of fission reactor simulators for space applications. A key component in these simulated reactors is the thermal simulator, designed to closely mimic the form and function of a nuclear fuel pin using electric heating. Continuing effort has been made to design simple, robust, inexpensive thermal simulators that closely match the steady-state and transient performance of a nuclear fuel pin. A series of these simulators have been designed, developed, fabricated and tested individually and in a number of simulated reactor systems at the EFF-TF. The purpose of the thermal simulators developed under the Fission Surface Power (FSP) task is to ensure that non-nuclear testing can be performed at sufficiently high fidelity to allow a cost-effective qualification and acceptance strategy to be used. Prototype thermal simulator design is founded on the baseline Fission Surface Power reactor design. Recent efforts have been focused on the design, fabrication and test of a prototype thermal simulator appropriate for use in the Technology Demonstration Unit (TDU). While designing the thermal simulators described in this paper, effort were made to improve the axial power profile matching of the thermal simulators. Simultaneously, a search was conducted for graphite materials with higher resistivities than had been employed in the past. The combination of these two efforts resulted in the creation of thermal simulators with power capacities of 2300-3300 W per unit. Six of these elements were installed in a simulated core and tested in the alkali metal-cooled Fission Surface Power Primary Test Circuit (FSP-PTC) at a variety of liquid metal flow rates and temperatures. This paper documents the design of the thermal simulators, test program, and test results.

  4. Integrating Biosystem Models Using Waveform Relaxation

    Directory of Open Access Journals (Sweden)

    Seymour RobertM

    2008-01-01

    Full Text Available Modelling in systems biology often involves the integration of component models into larger composite models. How to do this systematically and efficiently is a significant challenge: coupling of components can be unidirectional or bidirectional, and of variable strengths. We adapt the waveform relaxation (WR method for parallel computation of ODEs as a general methodology for computing systems of linked submodels. Four test cases are presented: (i a cascade of unidirectionally and bidirectionally coupled harmonic oscillators, (ii deterministic and stochastic simulations of calcium oscillations, (iii single cell calcium oscillations showing complex behaviour such as periodic and chaotic bursting, and (iv a multicellular calcium model for a cell plate of hepatocytes. We conclude that WR provides a flexible means to deal with multitime-scale computation and model heterogeneity. Global solutions over time can be captured independently of the solution techniques for the individual components, which may be distributed in different computing environments.

  5. Integrating Biosystem Models Using Waveform Relaxation

    Directory of Open Access Journals (Sweden)

    Stephen Baigent

    2008-12-01

    Full Text Available Modelling in systems biology often involves the integration of component models into larger composite models. How to do this systematically and efficiently is a significant challenge: coupling of components can be unidirectional or bidirectional, and of variable strengths. We adapt the waveform relaxation (WR method for parallel computation of ODEs as a general methodology for computing systems of linked submodels. Four test cases are presented: (i a cascade of unidirectionally and bidirectionally coupled harmonic oscillators, (ii deterministic and stochastic simulations of calcium oscillations, (iii single cell calcium oscillations showing complex behaviour such as periodic and chaotic bursting, and (iv a multicellular calcium model for a cell plate of hepatocytes. We conclude that WR provides a flexible means to deal with multitime-scale computation and model heterogeneity. Global solutions over time can be captured independently of the solution techniques for the individual components, which may be distributed in different computing environments.

  6. Consistency of Post-Newtonian Waveforms with Numerical Relativity

    Science.gov (United States)

    Baker, John G.; vanMeter, James R.; McWilliams, Sean T.; Centrella, Joan; Kelly, Bernard J.

    2007-01-01

    General relativity predicts the gravitational radiation signatures of mergers of compact binaries,such as coalescing binary black hole systems. Derivations of waveform predictions for such systems are required for optimal scientific analysis of observational gravitational wave data, and have so far been achieved primarily with the aid of the post-Newtonian (PN) approximation. The quaIity of this treatment is unclear, however, for the important late inspiral portion. We derive late-inspiral wave forms via a complementary approach, direct numerical simulation of Einstein's equations, which has recently matured sufficiently for such applications. We compare waveform phasing from simulations covering the last approximately 14 cycles of gravitational radiation from an equal-mass binary system of nonspinning black holes with corresponding 3PN and 3.5PN waveforms. We find phasing agreement consistent with internal error estimates based in either approach, at the level of one radian over approximately 10 cycles. The result suggests that PN waveforms for this system are effective roughly until the system reaches its last stable orbit just prior to the final merger.

  7. Synchronous Generator Model Parameter Estimation Based on Noisy Dynamic Waveforms

    Science.gov (United States)

    Berhausen, Sebastian; Paszek, Stefan

    2016-01-01

    In recent years, there have occurred system failures in many power systems all over the world. They have resulted in a lack of power supply to a large number of recipients. To minimize the risk of occurrence of power failures, it is necessary to perform multivariate investigations, including simulations, of power system operating conditions. To conduct reliable simulations, the current base of parameters of the models of generating units, containing the models of synchronous generators, is necessary. In the paper, there is presented a method for parameter estimation of a synchronous generator nonlinear model based on the analysis of selected transient waveforms caused by introducing a disturbance (in the form of a pseudorandom signal) in the generator voltage regulation channel. The parameter estimation was performed by minimizing the objective function defined as a mean square error for deviations between the measurement waveforms and the waveforms calculated based on the generator mathematical model. A hybrid algorithm was used for the minimization of the objective function. In the paper, there is described a filter system used for filtering the noisy measurement waveforms. The calculation results of the model of a 44 kW synchronous generator installed on a laboratory stand of the Institute of Electrical Engineering and Computer Science of the Silesian University of Technology are also given. The presented estimation method can be successfully applied to parameter estimation of different models of high-power synchronous generators operating in a power system.

  8. State of the Art Assessment of Simulation in Advanced Materials Development

    Science.gov (United States)

    Wise, Kristopher E.

    2008-01-01

    Advances in both the underlying theory and in the practical implementation of molecular modeling techniques have increased their value in the advanced materials development process. The objective is to accelerate the maturation of emerging materials by tightly integrating modeling with the other critical processes: synthesis, processing, and characterization. The aims of this report are to summarize the state of the art of existing modeling tools and to highlight a number of areas in which additional development is required. In an effort to maintain focus and limit length, this survey is restricted to classical simulation techniques including molecular dynamics and Monte Carlo simulations.

  9. Numerical simulation of production from tight-gas reservoirs by advanced stimulation technologies

    OpenAIRE

    Friedel, Torsten

    2009-01-01

    The present thesis focusses on two main issues: (i) the development of a multi-phase simulation tool for the characteristics of tight-gas reservoirs, and (ii) the investigation of advanced stimulation techniques. The latter mainly implies the analysis of certain damaging mechanisms, as well as the derivation of general modelling guidelines for fractured wells and underbalanced drilling. A special simulation tool is developed, realised in a Fortran-MATLAB coupling. The numerical model is based...

  10. Iron Resources and Oceanic Nutrients: Advancement of Global Environment Simulations

    Science.gov (United States)

    Debaar, H. J.

    2002-12-01

    simulated. An existing plankton ecosystem model already well predicts limitation by four nutrients (N, P, Si, Fe) of two algal groups (diatoms and nanoplankton) including export and CO2 air/sea exchange. This is being expanded with 3 other groups of algae and DMS(P)pathways. Next this extended ecosystem model is being simplified while maintaining reliable output for export and CO2/DMS gas exchange. This unit will then be put into two existing OBCM's. Inputs of Fe from above and below into the oceans have been modeled. Moreover a simple global Fe cycling model has been verified versus field data and insights. Two different OBCM's with same upper ocean ecosystem/DMS unit and Fe cycling will be verified versus pre-industrial and present conditions. Next climate change scenario's, notably changes in Fe inputs, will be run, with special attention to climatic feedbacks (warming) on the oceanic cycles and fluxes.

  11. Advances in multi-physics and high performance computing in support of nuclear reactor power systems modeling and simulation

    International Nuclear Information System (INIS)

    Significant advances in computational performance have occurred over the past two decades, achieved not only by the introduction of more powerful processors but the incorporation of parallelism in computer hardware at all levels. Simultaneous with these hardware and associated system software advances have been advances in modeling physical phenomena and the numerical algorithms to allow their usage in simulation. This paper presents a review of the advances in computer performance, discusses the modeling and simulation capabilities required to address the multi-physics and multi-scale phenomena applicable to a nuclear reactor core simulator, and present examples of relevant physics simulation codes' performances on high performance computers.

  12. Lightning current waveform measuring system

    Science.gov (United States)

    Wojtasinski, R. J.; Fuchs, J. C.; Grove, C. H. (Inventor)

    1978-01-01

    An apparatus is described for monitoring current waveforms produced by lightning strikes which generate currents in an elongated cable. These currents are converted to voltages and to light waves for being transmitted over an optical cable to a remote location. At the remote location, the waves are reconstructed back into electrical waves for being stored into a memory. The information is stored within the memory with a timing signal so that only different signals need be stored in order to reconstruct the wave form.

  13. An infrasound waveform digitization system

    International Nuclear Information System (INIS)

    An Infrasound Waveform Digitization System (IWDS) was introduced in detail in this paper. There are some functions in this system, such as scanning, rotating, image clipping, cleaning horizontal and vertical lines, wave tracking, etc. based on some algorithms of image processing. The key techniques include wavelet analysis, image thinning, pixel tracing in this system. With this system, it is possible to analyze historical infrasound drawing recorded in paper by using computer. Application of IWDS will be of help to the progress in nuclear explosion monitoring in the atmosphere, locating sources, estimating explosion energies, earthquake prediction, and geophysical researches. (authors)

  14. The role of experience and advanced training on performance in a motorcycle simulator.

    Science.gov (United States)

    Crundall, David; Stedmon, Alex W; Crundall, Elizabeth; Saikayasit, Rossukorn

    2014-12-01

    Motorcyclists are over-represented in collision statistics. While many collisions may be the direct fault of another road user, a considerable number of fatalities and injuries are due to the actions of the rider. While increased riding experience may improve skills, advanced training courses may be required to evoke the safest riding behaviours. The current research assessed the impact of experience and advanced training on rider behaviour using a motorcycle simulator. Novice riders, experienced riders and riders with advanced training traversed a virtual world through varying speed limits and roadways of different curvature. Speed and lane position were monitored. In a comparison of 60 mph and 40 mph zones, advanced riders rode more slowly in the 40 mph zones, and had greater variation in lane position than the other two groups. In the 60 mph zones, both advanced and experienced riders had greater lane variation than novices. Across the whole ride, novices tended to position themselves closer to the kerb. In a second analysis across four classifications of curvature (straight, slight, medium, tight) advanced and experienced riders varied their lateral position more so than novices, though advanced riders had greater variation in lane position than even experienced riders in some conditions. The results suggest that experience and advanced training lead to changes in behaviour compared to novice riders which can be interpreted as having a potentially positive impact on road safety. PMID:25180786

  15. Fractal characteristics for binary noise radar waveform

    Science.gov (United States)

    Li, Bing C.

    2016-05-01

    Noise radars have many advantages over conventional radars and receive great attentions recently. The performance of a noise radar is determined by its waveforms. Investigating characteristics of noise radar waveforms has significant value for evaluating noise radar performance. In this paper, we use binomial distribution theory to analyze general characteristics of binary phase coded (BPC) noise waveforms. Focusing on aperiodic autocorrelation function, we demonstrate that the probability distributions of sidelobes for a BPC noise waveform depend on the distances of these sidelobes to the mainlobe. The closer a sidelobe to the mainlobe, the higher the probability for this sidelobe to be a maximum sidelobe. We also develop Monte Carlo framework to explore the characteristics that are difficult to investigate analytically. Through Monte Carlo experiments, we reveal the Fractal relationship between the code length and the maximum sidelobe value for BPC waveforms, and propose using fractal dimension to measure noise waveform performance.

  16. Global mantle waveform tomography using the Spectral Element Method

    Science.gov (United States)

    Romanowicz, B. A.; French, S.; Masson, Y.; Jiménez-Pérez, H.

    2015-12-01

    In the past 20 years, we developed several generations of global mantle shear velocity models based entirely on time domain waveform inversion. This implies computations of synthetics in 3D earth models. Initially, the method of choice relied on normal mode perturbation theory, within which we built the framework of our inversion methodology. The latter includes, among others, windowing of waveforms to bring out contribution of weak amplitude phases, (e,g, Sdiff), and a fast converging quasi-Newton inversion with an approximate Hessian calculated using non-linear asymptotic coupling theory (NACT, Li and Romanowicz, 1995). Recently, the Spectral Element Method (SEM) was introduced in global seismology as a powerful numerical method to compute the seismic wavefield accurately in arbitrary 3D models (Komatitsch and Vilotte, 1998; Komatitsch and Tromp, 2002). Implementing the numerical SEM synthetics was straightforward, albeit with significantly increased cost of computation. In order to advance mantle imaging at the global scale, we introduced computational efficiencies, such as (1) substituting a fine layered crustal model by an equivalent, smooth, "homogeneized" crust designed to fit a global surface wave dispersion dataset, (2) continuing quasi-Newton inversion using NACT rather than adjoints, which involved the development of an efficient matrix assembly method (French et al., 2015), and (3) stepping progressively from long to short periods. The resulting models (Lekic and Romanowicz, 2011; French et al., 2013; French and Romanowicz, 2014), in particular, confirm the presence of deep mantle plumes beneath many major hotspots (French and Romanowicz, 2015). We discuss the choice of inverse approach, and illustrate the stability of our global models, in view of the use of NACT kernels, with respect to the choice of the starting model. Global inversion remains a challenge as higher resolution implies reaching higher frequencies to capture more of the scattered

  17. Proposing "the burns suite" as a novel simulation tool for advancing the delivery of burns education.

    Science.gov (United States)

    Sadideen, Hazim; Wilson, David; Moiemen, Naiem; Kneebone, Roger

    2014-01-01

    Educational theory highlights the importance of contextualized simulation for effective learning. We explored this concept in a burns scenario in a novel, low-cost, high-fidelity, portable, immersive simulation environment (referred to as distributed simulation). This contextualized simulation/distributed simulation combination was named "The Burns Suite" (TBS). A pediatric burn resuscitation scenario was selected after high trainee demand. It was designed on Advanced Trauma and Life Support and Emergency Management of Severe Burns principles and refined using expert opinion through cognitive task analysis. TBS contained "realism" props, briefed nurses, and a simulated patient. Novices and experts were recruited. Five-point Likert-type questionnaires were developed for face and content validity. Cronbach's α was calculated for scale reliability. Semistructured interviews captured responses for qualitative thematic analysis allowing for data triangulation. Twelve participants completed TBS scenario. Mean face and content validity ratings were high (4.6 and 4.5, respectively; range, 4-5). The internal consistency of questions was high. Qualitative data analysis revealed that participants felt 1) the experience was "real" and they were "able to behave as if in a real resuscitation environment," and 2) TBS "addressed what Advanced Trauma and Life Support and Emergency Management of Severe Burns didn't" (including the efficacy of incorporating nontechnical skills). TBS provides a novel, effective simulation tool to significantly advance the delivery of burns education. Recreating clinical challenge is crucial to optimize simulation training. This low-cost approach also has major implications for surgical education, particularly during increasing financial austerity. Alternative scenarios and/or procedures can be recreated within TBS, providing a diverse educational immersive simulation experience. PMID:23877145

  18. Development of advanced driver assistance systems with vehicle hardware-in-the-loop simulations

    NARCIS (Netherlands)

    Gietelink, O.J.; Ploeg, J.; Schutter, B.de; Verhaegen, M.

    2006-01-01

    This paper presents a new method for the design and validation of advanced driver assistance systems (ADASs). With vehicle hardware-in-the-loop (VEHIL) simulations, the development process, and more specifically the validation phase, of intelligent vehicles is carried out safer, cheaper, and is more

  19. Wideband Waveform Design for Robust Target Detection

    OpenAIRE

    Panahi, Ashkan; Ström, Marie; Viberg, Mats

    2014-01-01

    Future radar systems are expected to use waveforms of a high bandwidth, where the main advantage is an improved range resolution. In this paper, a technique to design robust wideband waveforms for a Multiple-Input-Single-Output system is developed. The context is optimal detection of a single object with partially unknown parameters. The waveforms are robust in the sense that, for a single transmission, detection capability is maintained over an interval of time-delay and time-scaling (Dopple...

  20. Simulation research and optimal design for digital power regulating system of China advanced research reactor

    International Nuclear Information System (INIS)

    Based on SimPort simulation platform of nuclear power plant, a simulation model for Digital Power Regulating System (DPRS) of China Advanced Research Reactor (CARR) was established. By simulating the transient state of DPRS using this model, the adjusting parameters for the digital PID controller were determined. According to the features of the driving mechanism, the effects of the driving accuracy of the control rod and the displacement delay between electromagnetic coil and armature upon system stability and the regulating performance were analyzed, furthermore, their stability limit values were obtained respectively. The research results of this paper have some engineering practical value. (authors)

  1. A marked point process for modeling lidar waveforms.

    Science.gov (United States)

    Mallet, Clément; Lafarge, Florent; Roux, Michel; Soergel, Uwe; Bretar, Frédéric; Heipke, Christian

    2010-12-01

    Lidar waveforms are 1-D signals representing a train of echoes caused by reflections at different targets. Modeling these echoes with the appropriate parametric function is useful to retrieve information about the physical characteristics of the targets. This paper presents a new probabilistic model based upon a marked point process which reconstructs the echoes from recorded discrete waveforms as a sequence of parametric curves. Such an approach allows to fit each mode of a waveform with the most suitable function and to deal with both, symmetric and asymmetric, echoes. The model takes into account a data term, which measures the coherence between the models and the waveforms, and a regularization term, which introduces prior knowledge on the reconstructed signal. The exploration of the associated configuration space is performed by a reversible jump Markov chain Monte Carlo (RJMCMC) sampler coupled with simulated annealing. Experiments with different kinds of lidar signals, especially from urban scenes, show the high potential of the proposed approach. To further demonstrate the advantages of the suggested method, actual laser scans are classified and the results are reported. PMID:20550992

  2. Development of a VOR/DME model for an advanced concepts simulator

    Science.gov (United States)

    Steinmetz, G. G.; Bowles, R. L.

    1984-01-01

    The report presents a definition of a VOR/DME, airborne and ground systems simulation model. This description was drafted in response to a need in the creation of an advanced concepts simulation in which flight station design for the 1980 era can be postulated and examined. The simulation model described herein provides a reasonable representation of VOR/DME station in the continental United States including area coverage by type and noise errors. The detail in which the model has been cast provides the interested researcher with a moderate fidelity level simulator tool for conducting research and evaluation of navigator algorithms. Assumptions made within the development are listed and place certain responsibilities (data bases, communication with other simulation modules, uniform round earth, etc.) upon the researcher.

  3. Advanced manned space flight simulation and training: An investigation of simulation host computer system concepts

    Science.gov (United States)

    Montag, Bruce C.; Bishop, Alfred M.; Redfield, Joe B.

    1989-01-01

    The findings of a preliminary investigation by Southwest Research Institute (SwRI) in simulation host computer concepts is presented. It is designed to aid NASA in evaluating simulation technologies for use in spaceflight training. The focus of the investigation is on the next generation of space simulation systems that will be utilized in training personnel for Space Station Freedom operations. SwRI concludes that NASA should pursue a distributed simulation host computer system architecture for the Space Station Training Facility (SSTF) rather than a centralized mainframe based arrangement. A distributed system offers many advantages and is seen by SwRI as the only architecture that will allow NASA to achieve established functional goals and operational objectives over the life of the Space Station Freedom program. Several distributed, parallel computing systems are available today that offer real-time capabilities for time critical, man-in-the-loop simulation. These systems are flexible in terms of connectivity and configurability, and are easily scaled to meet increasing demands for more computing power.

  4. Advanced Simulation of Coupled Earthquake and Tsunami Events (ASCETE) - Simulation Techniques for Realistic Tsunami Process Studies

    Science.gov (United States)

    Behrens, Joern; Bader, Michael; Breuer, Alexander N.; van Dinther, Ylona; Gabriel, Alice-A.; Galvez Barron, Percy E.; Rahnema, Kaveh; Vater, Stefan; Wollherr, Stephanie

    2015-04-01

    At the End of phase 1 of the ASCETE project a simulation framework for coupled physics-based rupture generation with tsunami propagation and inundation is available. Adaptive mesh tsunami propagation and inundation by discontinuous Galerkin Runge-Kutta methods allows for accurate and conservative inundation schemes. Combined with a tree-based refinement strategy to highly optimize the code for high-performance computing architectures, a modeling tool for high fidelity tsunami simulations has been constructed. Validation results demonstrate the capacity of the software. Rupture simulation is performed by an unstructured tetrahedral discontinuous Galerking ADER discretization, which allows for accurate representation of complex geometries. The implemented code was nominated for and was selected as a finalist for the Gordon Bell award in high-performance computing. Highly realistic rupture events can be simulated with this modeling tool. The coupling of rupture induced wave activity and displacement with hydrodynamic equations still poses a major problem due to diverging time and spatial scales. Some insight from the ASCETE set-up could be gained and the presentation will focus on the coupled behavior of the simulation system. Finally, an outlook to phase 2 of the ASCETE project will be given in which further development of detailed physical processes as well as near-realistic scenario computations are planned. ASCETE is funded by the Volkswagen Foundation.

  5. Advances in the simulation and automated measurement of well-sorted granular material: 1. Simulation

    Science.gov (United States)

    Daniel Buscombe; Rubin, David M.

    2012-01-01

    1. In this, the first of a pair of papers which address the simulation and automated measurement of well-sorted natural granular material, a method is presented for simulation of two-phase (solid, void) assemblages of discrete non-cohesive particles. The purpose is to have a flexible, yet computationally and theoretically simple, suite of tools with well constrained and well known statistical properties, in order to simulate realistic granular material as a discrete element model with realistic size and shape distributions, for a variety of purposes. The stochastic modeling framework is based on three-dimensional tessellations with variable degrees of order in particle-packing arrangement. Examples of sediments with a variety of particle size distributions and spatial variability in grain size are presented. The relationship between particle shape and porosity conforms to published data. The immediate application is testing new algorithms for automated measurements of particle properties (mean and standard deviation of particle sizes, and apparent porosity) from images of natural sediment, as detailed in the second of this pair of papers. The model could also prove useful for simulating specific depositional structures found in natural sediments, the result of physical alterations to packing and grain fabric, using discrete particle flow models. While the principal focus here is on naturally occurring sediment and sedimentary rock, the methods presented might also be useful for simulations of similar granular or cellular material encountered in engineering, industrial and life sciences.

  6. PMT waveform modeling at the Daya Bay experiment

    Science.gov (United States)

    Sören, Jetter; Dan, Dwyer; Jiang, Wen-Qi; Liu, Da-Wei; Wang, Yi-Fang; Wang, Zhi-Min; Wen, Liang-Jian

    2012-08-01

    Detailed measurements of Hamamatsu R5912 photomultiplier signals are presented, including the single photoelectron charge response, waveform shape, nonlinearity, saturation, overshoot, oscillation, prepulsing, and afterpulsing. The results were used to build a detailed model of the PMT signal characteristics over a wide range of light intensities. Including the PMT model in simulated Daya Bay particle interactions shows no significant systematic effects that are detrimental to the experimental sensitivity.

  7. PMT waveform modeling at the Daya Bay experiment

    International Nuclear Information System (INIS)

    Detailed measurements of Hamamatsu R5912 photomultiplier signals are presented, including the single photoelectron charge response, waveform shape, nonlinearity, saturation, overshoot, oscillation, prepulsing, and afterpulsing. The results were used to build a detailed model of the PMT signal characteristics over a wide range of light intensities. Including the PMT model in simulated Daya Bay particle interactions shows no significant systematic effects that are detrimental to the experimental sensitivity. (authors)

  8. Editorial: Advances in Health Education Applying E-Learning, Simulations and Distance Technologies

    Directory of Open Access Journals (Sweden)

    Andre W. Kushniruk

    2011-03-01

    Full Text Available This special issue of the KM&EL international journal is dedicated to coverage of novel advances in health professional education applying e-Learning, simulations and distance education technologies. Modern healthcare is beginning to be transformed through the emergence of new information technologies and rapid advances in health informatics. Advances such as electronic health record systems (EHRs, clinical decision support systems and other advanced information systems such as public health surveillance systems are rapidly being deployed worldwide. The education of health professionals such as medical, nursing and allied health professionals will require an improved understanding of these technologies and how they will transform their healthcare practice. However, currently there is a lack of integration of knowledge and skills related to such technology in health professional education. In this issue of the journal we present articles that describe a set of novel approaches to integrating essential health information technology into the education of health professionals, as well as the use of advanced information technologies and e-Learning approaches for improving health professional education. The approaches range from use of simulations to development of novel Web-based platforms for allowing students to interact with the technologies and healthcare practices that are rapidly changing healthcare.

  9. The role of numerical simulation for the development of an advanced HIFU system

    Science.gov (United States)

    Okita, Kohei; Narumi, Ryuta; Azuma, Takashi; Takagi, Shu; Matumoto, Yoichiro

    2014-10-01

    High-intensity focused ultrasound (HIFU) has been used clinically and is under clinical trials to treat various diseases. An advanced HIFU system employs ultrasound techniques for guidance during HIFU treatment instead of magnetic resonance imaging in current HIFU systems. A HIFU beam imaging for monitoring the HIFU beam and a localized motion imaging for treatment validation of tissue are introduced briefly as the real-time ultrasound monitoring techniques. Numerical simulations have a great impact on the development of real-time ultrasound monitoring as well as the improvement of the safety and efficacy of treatment in advanced HIFU systems. A HIFU simulator was developed to reproduce ultrasound propagation through the body in consideration of the elasticity of tissue, and was validated by comparison with in vitro experiments in which the ultrasound emitted from the phased-array transducer propagates through the acrylic plate acting as a bone phantom. As the result, the defocus and distortion of the ultrasound propagating through the acrylic plate in the simulation quantitatively agree with that in the experimental results. Therefore, the HIFU simulator accurately reproduces the ultrasound propagation through the medium whose shape and physical properties are well known. In addition, it is experimentally confirmed that simulation-assisted focus control of the phased-array transducer enables efficient assignment of the focus to the target. Simulation-assisted focus control can contribute to design of transducers and treatment planning.

  10. The Osseus platform: a prototype for advanced web-based distributed simulation

    Science.gov (United States)

    Franceschini, Derrick; Riecken, Mark

    2016-05-01

    Recent technological advances in web-based distributed computing and database technology have made possible a deeper and more transparent integration of some modeling and simulation applications. Despite these advances towards true integration of capabilities, disparate systems, architectures, and protocols will remain in the inventory for some time to come. These disparities present interoperability challenges for distributed modeling and simulation whether the application is training, experimentation, or analysis. Traditional approaches call for building gateways to bridge between disparate protocols and retaining interoperability specialists. Challenges in reconciling data models also persist. These challenges and their traditional mitigation approaches directly contribute to higher costs, schedule delays, and frustration for the end users. Osseus is a prototype software platform originally funded as a research project by the Defense Modeling & Simulation Coordination Office (DMSCO) to examine interoperability alternatives using modern, web-based technology and taking inspiration from the commercial sector. Osseus provides tools and services for nonexpert users to connect simulations, targeting the time and skillset needed to successfully connect disparate systems. The Osseus platform presents a web services interface to allow simulation applications to exchange data using modern techniques efficiently over Local or Wide Area Networks. Further, it provides Service Oriented Architecture capabilities such that finer granularity components such as individual models can contribute to simulation with minimal effort.

  11. Leveraging waveform complexity for confident detection of gravitational waves

    CERN Document Server

    Kanner, Jonah B; Cornish, Neil; Millhouse, Meg; Xhakaj, Enia; Salemi, Francesco; Drago, Marco; Vedovato, Gabriele; Klimenko, Sergey

    2016-01-01

    The recent completion of Advanced LIGO suggests that gravitational waves (GWs) may soon be directly observed. Past searches for gravitational-wave transients have been impacted by transient noise artifacts, known as glitches, introduced into LIGO data due to instrumental and environmental effects. In this work, we explore how waveform complexity, instead of signal-to-noise ratio, can be used to rank event candidates and distinguish short duration astrophysical signals from glitches. We test this framework using a new hierarchical pipeline that directly compares the Bayesian evidence of explicit signal and glitch models. The hierarchical pipeline is shown to have strong performance, and in particular, allows high-confidence detections of a range of waveforms at realistic signal-to-noise ratio with a two detector network.

  12. Digital Waveform Generator Basedon FPGA

    Directory of Open Access Journals (Sweden)

    Shoucheng Ding

    2012-07-01

    Full Text Available Field Programmable Gate Array (FPGA of the Cyclone II series was as the core processor of frequency meter and the Quartus II was as the development plat form. This article had designed the fully digital signal generator. It use dall-digital frequency synthesizer technology and FPGA programming implemented the three waveforms: sin wave and square wave and triangle wave. The frequency was adjustable through10- bit phase accumulator and the analog multiplier achieved amplitude modulation. Using 51soft nuclear FPGA wrote a C program and realized the in put control word. The 4 × 4 matrix keyboard inputted frequency or amplitude value and the LCD1602displayedthem. The test results show that the system has high precision, distortion and low.

  13. FY05-FY06 Advanced Simulation and Computing Implementation Plan, Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Baron, A L

    2004-07-19

    The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the safety and reliability of the U.S. nuclear stockpile. The SSP uses past nuclear test data along with future non-nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program will require the continued use of current facilities and programs along with new experimental facilities and computational enhancements to support these programs. The Advanced Simulation and Computing program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources to support the annual stockpile assessment and certification, to study advanced nuclear weapon design and manufacturing processes, to analyze accident scenarios and weapons aging, and to provide the tools to enable stockpile life extension programs and the resolution of significant finding investigations (SFIs). This requires a balanced system of technical staff, hardware, simulation software, and computer science solutions.

  14. Advanced simulation technology for etching process design for CMOS device applications

    Science.gov (United States)

    Kuboi, Nobuyuki; Fukasawa, Masanaga; Tatsumi, Tetsuya

    2016-07-01

    Plasma etching is a critical process for the realization of high performance in the next generation of CMOS devices. To predict and control fluctuations in the etching properties accurately during mass production, it is essential that etching process simulation technology considers fluctuations in the plasma chamber wall conditions, the effects of by-products on the critical dimensions, the Si recess dependence on the wafer open area ratio and local pattern structure, and the time-dependent plasma-induced damage distribution associated with the three-dimensional feature scale profile at the 100 nm level. This consideration can overcome the issues with conventional simulations performed under the assumed ideal conditions, which are not accurate enough for practical process design. In this article, these advanced process simulation technologies are reviewed, and, from the results of suitable process simulations, a new etching system that automatically controls the etching properties is proposed to enable stable CMOS device fabrication with high yields.

  15. The Effect of Inlet Waveforms on Computational Hemodynamics of Patient-Specific Intracranial Aneurysms

    OpenAIRE

    J. Xiang; Siddiqui, A.H.; Meng, H.

    2014-01-01

    Due to the lack of patient-specific inlet flow waveform measurements, most computational fluid dynamics (CFD) simulations of intracranial aneurysms usually employ waveforms that are not patient-specific as inlet boundary conditions for the computational model. The current study examined how this assumption affects the predicted hemodynamics in patient-specific aneurysm geometries. We examined wall shear stress (WSS) and oscillatory shear index (OSI), the two most widely studied hemodynamic qu...

  16. Tailored voltage waveform capacitively coupled plasmas in electronegative gases:frequency dependence of asymmetry effects

    OpenAIRE

    Schüngel, E; Korolov, I.; Bruneau, Bastien; Derzsi, A.; Johnson, Erik V.; O'Connell, Deborah; Gans, Timo; Booth, Jean-Paul; Donko, Z.; Schulze, J.

    2016-01-01

    Capacitively coupled radio frequency plasmas operated in an electronegative gas (CF4) and driven by voltage waveforms composed of four consecutive harmonics are investigated for different fundamental driving frequencies using PIC/MCC simulations and an analytical model. As has been observed previously for electropositive gases, the application of peak-shaped waveforms (that are characterized by a strong amplitude asymmetry) results in the development of a DC self-bias due to the electrical as...

  17. CAPE-OPEN Integration for Advanced Process Engineering Co-Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Zitney, S.E.

    2006-11-01

    This paper highlights the use of the CAPE-OPEN (CO) standard interfaces in the Advanced Process Engineering Co-Simulator (APECS) developed at the National Energy Technology Laboratory (NETL). The APECS system uses the CO unit operation, thermodynamic, and reaction interfaces to provide its plug-and-play co-simulation capabilities, including the integration of process simulation with computational fluid dynamics (CFD) simulation. APECS also relies heavily on the use of a CO COM/CORBA bridge for running process/CFD co-simulations on multiple operating systems. For process optimization in the face of multiple and some time conflicting objectives, APECS offers stochastic modeling and multi-objective optimization capabilities developed to comply with the CO software standard. At NETL, system analysts are applying APECS to a wide variety of advanced power generation systems, ranging from small fuel cell systems to commercial-scale power plants including the coal-fired, gasification-based FutureGen power and hydrogen production plant.

  18. The advanced simulation of fatigue crack growth in complex 3D structures

    Energy Technology Data Exchange (ETDEWEB)

    Kolk, Karsten; Kuhn, Guenther [Institute of Applied Mechanics, Erlangen (Germany)

    2006-12-15

    An advanced incremental crack growth algorithm for the three-dimensional (3D) simulation of fatigue crack growth in complex 3D structures with linear elastic material behavior is presented. To perform the crack growth simulation as effectively as possible an accurate stress analysis is done by the boundary-element method (BEM) in terms of the 3D dual BEM. The question concerning a reliable 3D crack growth criterion is answered based on experimental observations. All criteria under consideration are numerically realized by a predictor-corrector procedure. The agreement between numerically determined and experimentally observed crack fronts will be shown on both fracture specimens and an industrial application. (orig.)

  19. Advanced Simulation and Computing FY10-11 Implementation Plan Volume 2, Rev. 0

    Energy Technology Data Exchange (ETDEWEB)

    Carnes, B

    2009-06-08

    The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the surety and reliability of the U.S. nuclear stockpile. The SSP uses past nuclear test data along with current and future non-nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of current facilities and programs along with new experimental facilities and computational enhancements to support these programs. The Advanced Simulation and Computing Program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources to support the annual stockpile assessment and certification, to study advanced nuclear weapons design and manufacturing processes, to analyze accident scenarios and weapons aging, and to provide the tools to enable stockpile Life Extension Programs (LEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balanced resource, including technical staff, hardware, simulation software, and computer science solutions. In its first decade, the ASC strategy focused on demonstrating simulation capabilities of unprecedented scale in three spatial dimensions. In its second decade, ASC is focused on increasing its predictive capabilities in a three-dimensional simulation environment while maintaining support to the SSP. The program continues to improve its unique tools for solving progressively more difficult stockpile problems (focused on sufficient resolution, dimensionality and scientific details); to quantify critical margins and uncertainties (QMU); and to resolve increasingly difficult analyses needed for the SSP. Moreover, ASC has restructured its business model from one that

  20. Advanced Simulation and Computing FY09-FY10 Implementation Plan, Volume 2, Revision 0.5

    Energy Technology Data Exchange (ETDEWEB)

    Meisner, R; Hopson, J; Peery, J; McCoy, M

    2008-10-07

    The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the surety and reliability of the U.S. nuclear stockpile. The SSP uses past nuclear test data along with current and future non-nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of current facilities and programs along with new experimental facilities and computational enhancements to support these programs. The Advanced Simulation and Computing Program (ASC)1 is a cornerstone of the SSP, providing simulation capabilities and computational resources to support the annual stockpile assessment and certification, to study advanced nuclear weapons design and manufacturing processes, to analyze accident scenarios and weapons aging, and to provide the tools to enable stockpile Life Extension Programs (LEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balanced resource, including technical staff, hardware, simulation software, and computer science solutions. In its first decade, the ASC strategy focused on demonstrating simulation capabilities of unprecedented scale in three spatial dimensions. In its second decade, ASC is focused on increasing its predictive capabilities in a three-dimensional simulation environment while maintaining support to the SSP. The program continues to improve its unique tools for solving progressively more difficult stockpile problems (focused on sufficient resolution, dimensionality and scientific details); to quantify critical margins and uncertainties (QMU); and to resolve increasingly difficult analyses needed for the SSP. Moreover, ASC has restructured its business model from one

  1. Advanced Simulation and Computing FY09-FY10 Implementation Plan Volume 2, Rev. 1

    Energy Technology Data Exchange (ETDEWEB)

    Kissel, L

    2009-04-01

    The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the surety and reliability of the U.S. nuclear stockpile. The SSP uses past nuclear test data along with current and future non-nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of current facilities and programs along with new experimental facilities and computational enhancements to support these programs. The Advanced Simulation and Computing Program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources to support the annual stockpile assessment and certification, to study advanced nuclear weapons design and manufacturing processes, to analyze accident scenarios and weapons aging, and to provide the tools to enable stockpile Life Extension Programs (LEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balanced resource, including technical staff, hardware, simulation software, and computer science solutions. In its first decade, the ASC strategy focused on demonstrating simulation capabilities of unprecedented scale in three spatial dimensions. In its second decade, ASC is focused on increasing its predictive capabilities in a three-dimensional simulation environment while maintaining support to the SSP. The program continues to improve its unique tools for solving progressively more difficult stockpile problems (focused on sufficient resolution, dimensionality and scientific details); to quantify critical margins and uncertainties (QMU); and to resolve increasingly difficult analyses needed for the SSP. Moreover, ASC has restructured its business model from one that

  2. Advanced Simulation and Computing FY10-FY11 Implementation Plan Volume 2, Rev. 0.5

    Energy Technology Data Exchange (ETDEWEB)

    Meisner, R; Peery, J; McCoy, M; Hopson, J

    2009-09-08

    The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the surety and reliability of the U.S. nuclear stockpile. The SSP uses past nuclear test data along with current and future non-nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering (D&E) programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of current facilities and programs along with new experimental facilities and computational enhancements to support these programs. The Advanced Simulation and Computing Program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources to support the annual stockpile assessment and certification, to study advanced nuclear weapons design and manufacturing processes, to analyze accident scenarios and weapons aging, and to provide the tools to enable stockpile Life Extension Programs (LEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balanced resource, including technical staff, hardware, simulation software, and computer science solutions. In its first decade, the ASC strategy focused on demonstrating simulation capabilities of unprecedented scale in three spatial dimensions. In its second decade, ASC is focused on increasing its predictive capabilities in a three-dimensional (3D) simulation environment while maintaining support to the SSP. The program continues to improve its unique tools for solving progressively more difficult stockpile problems (focused on sufficient resolution, dimensionality and scientific details); to quantify critical margins and uncertainties (QMU); and to resolve increasingly difficult analyses needed for the SSP. Moreover, ASC has restructured its business model

  3. Advanced Simulation and Computing FY08-09 Implementation Plan, Volume 2, Revision 0.5

    Energy Technology Data Exchange (ETDEWEB)

    Kusnezov, D; Bickel, T; McCoy, M; Hopson, J

    2007-09-13

    The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the surety and reliability of the U.S. nuclear stockpile. The SSP uses past nuclear test data along with current and future non-nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of current facilities and programs along with new experimental facilities and computational enhancements to support these programs. The Advanced Simulation and Computing Program (ASC)1 is a cornerstone of the SSP, providing simulation capabilities and computational resources to support the annual stockpile assessment and certification, to study advanced nuclear-weapons design and manufacturing processes, to analyze accident scenarios and weapons aging, and to provide the tools to enable Stockpile Life Extension Programs (SLEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balanced resource, including technical staff, hardware, simulation software, and computer science solutions. In its first decade, the ASC strategy focused on demonstrating simulation capabilities of unprecedented scale in three spatial dimensions. In its second decade, ASC is focused on increasing its predictive capabilities in a three-dimensional simulation environment while maintaining the support to the SSP. The program continues to improve its unique tools for solving progressively more difficult stockpile problems (focused on sufficient resolution, dimensionality and scientific details); to quantify critical margins and uncertainties (QMU); and to resolve increasingly difficult analyses needed for the SSP. Moreover, ASC has restructured its business model from

  4. Advanced Simulation and Computing FY08-09 Implementation Plan Volume 2 Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    McCoy, M; Kusnezov, D; Bikkel, T; Hopson, J

    2007-04-25

    The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the safety and reliability of the U.S. nuclear stockpile. The SSP uses past nuclear test data along with current and future nonnuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of current facilities and programs along with new experimental facilities and computational enhancements to support these programs. The Advanced Simulation and Computing Program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources to support the annual stockpile assessment and certification, to study advanced nuclear-weapons design and manufacturing processes, to analyze accident scenarios and weapons aging, and to provide the tools to enable Stockpile Life Extension Programs (SLEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balanced resource, including technical staff, hardware, simulation software, and computer science solutions. In its first decade, the ASC strategy focused on demonstrating simulation capabilities of unprecedented scale in three spatial dimensions. In its second decade, ASC is focused on increasing its predictive capabilities in a three-dimensional simulation environment while maintaining the support to the SSP. The program continues to improve its unique tools for solving progressively more difficult stockpile problems (focused on sufficient resolution, dimensionality and scientific details); to quantify critical margins and uncertainties (QMU); and to resolve increasingly difficult analyses needed for the SSP. Moreover, ASC has restructured its business model from one

  5. Advanced Simulation and Computing FY07-08 Implementation Plan Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Kusnezov, D; Hale, A; McCoy, M; Hopson, J

    2006-06-22

    The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the safety and reliability of the U.S. nuclear stockpile. The SSP uses past nuclear test data along with current and future nonnuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program will require the continued use of current facilities and programs along with new experimental facilities and computational enhancements to support these programs. The Advanced Simulation and Computing Program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources to support the annual stockpile assessment and certification, to study advanced nuclear-weapons design and manufacturing processes, to analyze accident scenarios and weapons aging, and to provide the tools to enable Stockpile Life Extension Programs (SLEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balanced resource, including technical staff, hardware, simulation software, and computer science solutions. In its first decade, the ASC strategy focused on demonstrating simulation capabilities of unprecedented scale in three spatial dimensions. In its second decade, ASC is focused on increasing its predictive capabilities in a three-dimensional simulation environment while maintaining the support to the SSP. The program continues to improve its unique tools for solving progressively more difficult stockpile problems (focused on sufficient resolution, dimensionality and scientific details); to quantify critical margins and uncertainties (QMU); and to resolve increasingly difficult analyses needed for the SSP. Moreover, ASC has restructured its business model from

  6. Numerical Simulation of Polarity Characteristics of Vector Elastic Wave of Advanced Detection in the Roadway

    OpenAIRE

    Deng Shuaiqi; Yue Jianhua; Cao Jing; Zhang Xin

    2013-01-01

    The high-order staggering grid Finite-Difference (FD) scheme based on first-order velocity-stress elastic wave equation has been deduced. The calculation method of PML boundary condition and stability condition established in this study can be used for numerical simulation of advanced detection of elastic wave in roadway, with the obtaining of high-precision seismogram. Then we systematically analyze the polarity of vector wave field in post-source observation system. The results indicate tha...

  7. Transition of Monju simulator training owing to Monju accident and upgrade of Monju advanced reactor simulator (MARS)

    International Nuclear Information System (INIS)

    The Monju advanced reactor simulator (MARS) has been operated for training of Monju operators and for verification of Monju operating manual's appropriateness since 1991 for over 11 years. This report covers transition of Monju training system and modified of MARS owing to Monju accident as operating experience of MARS on from 1994 to 2001. The principal points mentioned are as follows: (1) Improved Monju training system owing to Monju accident 1) Reinforcement of sodium handling and sodium fire-fighting exercise. 2) Improved of training system and revised of training frequency. 3) Introduced of evaluation and analysis system regarding training results. 4) Providing of training guide line. 5) Step up of fundamental education by introducing of CAI (Computer Assisted Instruction System). (2) Upgrade of MARS for Monju restarting. 1) Reflected of the real plant data obtained from Monju performance test. 2) Addition of malfunction items. 3) Development of simulation software and addition of simulation panel concerning reinforced sodium leakage corresponding training. 4) Improvement of simulation ability and remodeling of calculating model by renewal of computer system. 5) Up graded program in the future. (author)

  8. Overview of the Consortium for the Advanced Simulation of Light Water Reactors (CASL

    Directory of Open Access Journals (Sweden)

    Kulesza Joel A.

    2016-01-01

    Full Text Available The Consortium for Advanced Simulation of Light Water Reactors (CASL was established in July 2010 for the purpose of providing advanced modeling and simulation solutions for commercial nuclear reactors. The primary goal is to provide coupled, higher-fidelity, usable modeling and simulation capabilities than are currently available. These are needed to address light water reactor (LWR operational and safety performance-defining phenomena that are not yet able to be fully modeled taking a first-principles approach. In order to pursue these goals, CASL has participation from laboratory, academic, and industry partners. These partners are pursuing the solution of ten major “Challenge Problems” in order to advance the state-of-the-art in reactor design and analysis to permit power uprates, higher burnup, life extension, and increased safety. At present, the problems being addressed by CASL are primarily reactor physics-oriented; however, this paper is intended to introduce CASL to the reactor dosimetry community because of the importance of reactor physics modelling and nuclear data to define the source term for that community and the applicability and extensibility of the transport methods being developed.

  9. Overview of the Consortium for the Advanced Simulation of Light Water Reactors (CASL)

    Science.gov (United States)

    Kulesza, Joel A.; Franceschini, Fausto; Evans, Thomas M.; Gehin, Jess C.

    2016-02-01

    The Consortium for Advanced Simulation of Light Water Reactors (CASL) was established in July 2010 for the purpose of providing advanced modeling and simulation solutions for commercial nuclear reactors. The primary goal is to provide coupled, higher-fidelity, usable modeling and simulation capabilities than are currently available. These are needed to address light water reactor (LWR) operational and safety performance-defining phenomena that are not yet able to be fully modeled taking a first-principles approach. In order to pursue these goals, CASL has participation from laboratory, academic, and industry partners. These partners are pursuing the solution of ten major "Challenge Problems" in order to advance the state-of-the-art in reactor design and analysis to permit power uprates, higher burnup, life extension, and increased safety. At present, the problems being addressed by CASL are primarily reactor physics-oriented; however, this paper is intended to introduce CASL to the reactor dosimetry community because of the importance of reactor physics modelling and nuclear data to define the source term for that community and the applicability and extensibility of the transport methods being developed.

  10. Waveform inversion of acoustic waves for explosion yield estimation

    Science.gov (United States)

    Kim, K.; Rodgers, A.

    2016-07-01

    We present a new waveform inversion technique to estimate the energy of near-surface explosions using atmospheric acoustic waves. Conventional methods often employ air blast models based on a homogeneous atmosphere, where the acoustic wave propagation effects (e.g., refraction and diffraction) are not taken into account, and therefore, their accuracy decreases with increasing source-receiver distance. In this study, three-dimensional acoustic simulations are performed with a finite difference method in realistic atmospheres and topography, and the modeled acoustic Green's functions are incorporated into the waveform inversion for the acoustic source time functions. The strength of the acoustic source is related to explosion yield based on a standard air blast model. The technique was applied to local explosions (structure. The presented method can be extended to explosions recorded at far distance provided proper meteorological specifications.

  11. Planning of development strategy for establishment of advanced simulation of nuclear system

    International Nuclear Information System (INIS)

    In this product, the long term development plan in each technical area has been prosed with the plan of coupled code system. The consolidated code system for safety analysis has been proposing for future needs. The computing hardware needed for te advanced simulation is also proposing. The best approach for future safety analysis simulation capabilities may be a dual-path program. i. e. the development programs for an integrated analysis tool and multi-scale/multi-physic analysis tools, where the former aims at reducing uncertainty and the latter at enhancing accuracy. Integrated analysis tool with risk informed safety margin quantification It requires a significant extension of the phenomenological and geometric capabilities of existing reactor safety analysis software, capable of detailed simulations that reduce the uncertainties. Multi-scale, multi-physics analysis tools. Simplifications of complex phenomenological models and dependencies have been made in current safety analyses to accommodate computer hardware limitations. With the advent of modern computer hardware, these limitations may be removed to permit greater accuracy in representation of physical behavior of materials in design basis and beyond design basis conditions, and hence more accurate assessment of the true safety margins based on first principle methodology. The proposals can be utilized to develop the advanced simulation project and formulation of organization and establishment of high performance computing system in KAERI

  12. Attosecond control of optical waveforms

    International Nuclear Information System (INIS)

    A new, monolithic scheme for stabilizing the phase between the carrier wave and the envelope (CE phase) in a train of few-cycle laser pulses is demonstrated. Self-phase modulation and second-harmonic generation or difference-frequency generation in a single periodically poled lithium niobate crystal, that transmits the main laser beam, allows for the CE-phase locking directly in the usable output. The monolithic scheme obviates the need for splitting off a fraction of the laser output for CE-phase control, coupling into microstructured fibre, as well as separation and recombination of spectral components. As a result, the CE-phase error integrated over the spectral range of 0.2 mHz-35 MHz is as small as 0.016 x 2π rad. This implies that the phase of the field oscillations (λ ∼ 830 nm) with respect to the pulse peak is locked to within 44 attoseconds, resulting in optical waveform control with subhundred attosecond fidelity for the first time

  13. Parallel Algorithm in Surface Wave Waveform Inversion

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In Surface wave waveform inversion, we want to reconstruct 3Dshear wav e velocity structure, which calculation beyond the capability of the powerful pr esent day personal computer or even workstation. So we designed a high parallele d algorithm and carried out the inversion on Parallel computer based on the part itioned waveform inversion (PWI). It partitions the large scale optimization pro blem into a number of independent small scale problems and reduces the computati onal effort by several orders of magnitude. We adopted surface waveform inversio n with a equal block(2°×2°) discretization.

  14. Technical Basis for Physical Fidelity of NRC Control Room Training Simulators for Advanced Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Minsk, Brian S.; Branch, Kristi M.; Bates, Edward K.; Mitchell, Mark R.; Gore, Bryan F.; Faris, Drury K.

    2009-10-09

    The objective of this study is to determine how simulator physical fidelity influences the effectiveness of training the regulatory personnel responsible for examination and oversight of operating personnel and inspection of technical systems at nuclear power reactors. It seeks to contribute to the U.S. Nuclear Regulatory Commission’s (NRC’s) understanding of the physical fidelity requirements of training simulators. The goal of the study is to provide an analytic framework, data, and analyses that inform NRC decisions about the physical fidelity requirements of the simulators it will need to train its staff for assignment at advanced reactors. These staff are expected to come from increasingly diverse educational and experiential backgrounds.

  15. Simulation research and optimal design for digital power regulating system of China advanced research reactor

    International Nuclear Information System (INIS)

    Based on SimPort simulation platform of nuclear power plant, a simulation model for Digital Power Regulating System (DPRS) of China Advanced Research Reactor (CARR) was established. The transient state of DPRS was simulation studied using this model. According to the characteristics of the driving mechanism of the control rods, the effects of the driving precision of the control rod and its displacement delay upon the system stability were analyzed. Considering the process requirements of CARR and the function characteristic of DRPS, the adjusting parameters for the digital PID controller and the stability limits of the driving mechanism of the control rods were obtained. The sampling period of the digital PID controller is 100 ms and its proportion gain is 300. The stability limit of the driving precision of the control rod is 0.4 mm. The stability limit of displacement delay between electromagnetic coil and armature is 6.0 mm. (authors)

  16. Seismic full waveform inversion from compressive measurements

    Science.gov (United States)

    Ramirez, Ana; Arce, Gonzalo R.

    2015-05-01

    Traditional methods in seismic acquisition require sources and geophones that are uniformly located along a spatial line, using the Nyquist sampling rate. Depending on the area to be explored, it can be necessary to use seismic surveys with large offsets, or decrease the separation between adjacent geophones to improve the resolution, which generates very high volumes of data. It makes the exploration process more difficult and particularly expensive. This work presents the reconstruction of a compressive set of seismic traces acquired using the compressive sensing paradigm where the pair of sources and geophones are randomly located along the spatial line. The recovery of the wavefield from compressive measurements is feasible due to the capabilities of Curvelets on representing wave propagators with only a small set of coefficients. The method first uses the compressive samples to find a sparse vector representation of each pixel in a 2-D Curvelet dictionary. The sparse vector representation is estimated by solving a sparsity constrained optimization problem using the Gradient Projection for Sparse Reconstruction (GPSR) method. The estimated vector is then used to compute the seismic velocity profiles via acoustic Full Waveform Inversion (FWI). Simulations of the reconstructed image gathers and the resulting seismic velocity profiles illustrate the performance of the method. An improvement in the resulting images is obtained in comparison with traditional F-K filtering used in seismic data processing when traces are missing.

  17. Benchmarks for interface-tracking codes in the consortium for advanced simulation of LWRs (CASL)

    International Nuclear Information System (INIS)

    A major innovation pursued by the Consortium for Advanced Simulation of LWRs (CASL) is the use of Interface Tracking Methods (ITM) to generate high-fidelity closure relations for two-phase flow and heat transfer phenomena (e.g. nucleate boiling, bubble break-up and coalescence, vapor condensation, etc.), to be used in coarser CFD, subchannel and system codes. ITMs do not assume an idealized geometry of the interface between the liquid and vapor phases, but rather calculate it from ‘first principles’. Also, used within the context of high-fidelity turbulence simulations, such as Direct Numerical Simulation (DNS) or Large Eddy Simulation (LES), ITMs can resolve the velocity (including the fluctuating field) and temperature/scalar gradients near the liquid-vapor interface, so prediction of the exchange of momentum, mass and heat at the interface in principle requires no empirical correlations. The physical complexity of the two-phase flow and heat transfer phenomena encountered in LWRs naturally lends itself to an ITM analysis approach. Several codes featuring ITM capabilities are available within CASL. These are TransAT, STAR-CCM+, PHASTA, FTC3D and FELBM. They use a variety of ITMs ranging from Volume-Of- Fluid to Level-Set, from Front-Tracking to Lattice-Boltzmann. A series of benchmark simulations is being developed to test the key capabilities of these codes and their ITMs. In this paper, three such benchmark simulations, testing DNS, LES and interface tracking, respectively, are briefly described. (author)

  18. Advanced char burnout models for the simulation of pulverized coal fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    T. Severin; S. Wirtz; V. Scherer [Ruhr-University, Bochum (Germany). Institute of Energy Plant Technology (LEAT)

    2005-07-01

    The numerical simulation of coal combustion processes is widely used as an efficient means to predict burner or system behaviour. In this paper an approach to improve CFD simulations of pulverized coal fired boilers with advanced coal combustion models is presented. In simple coal combustion models, first order Arrhenius rate equations are used for devolatilization and char burnout. The accuracy of such simple models is sufficient for the basic aspects of heat release. The prediction of carbon-in-ash is one aspect of special interest in the simulation of pulverized coal fired boilers. To determine the carbon-in-ash levels in the fly ash of coal fired furnaces, the char burnout model has to be more detailed. It was tested, in how far changing operating conditions affect the carbon-in-ash prediction of the simulation. To run several test cases in a short time, a simplified cellnet model was applied. To use a cellnet model for simulations of pulverized coal fired boilers, it was coupled with a Lagrangian particle model, used in CFD simulations, too. 18 refs., 5 figs., 5 tabs.

  19. 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.

  20. Advanced graphic interface man machine for a simulator of nuclear processes for training in classroom

    International Nuclear Information System (INIS)

    This work describes a working prototype that will serve as experimental platform for the specification and development of a commercial classroom analysis simulator. The classroom analysis simulator will be used as analytical tool for an optimal and more efficient training of operation personnel of Laguna Verde Power Plant. The focus of this work is on the advanced graphical interface of the classroom analysis simulator and those issues involved with its design. This interface offers two distinctive features: 1) virtual representation of instrumentation and controls of different control panels; and 2) direct manipulation as main interaction method. These features provide an easy and intuitive way to manipulate and monitor virtual instrumentation as well as an effortless manner to control the interface. By using object menus with special control features, it is possible to perform visualization functions such as navigation among control panels, location of instrumentation, panning, zooming and reset. The system and its interface provide immediate feedback and reversible operation capabilities allowing an easy, fast and natural human-machine interaction within a graphical environment that the operator is familiar with. The system gives also access and displays a functional copy of the Laguna Verde Safety Parameters Display System. In addition, a special set of graphic displays representing the full animation of transients and severe accidents via output data files from specialized nuclear codes are being designed. The features of the system mentioned above, supported by advanced mathematical models, currently under development, will provide an exceptional simulation environment. It is expected that the simulator will be used not only as an alternative to reduce expensive load of the current hard wire simulator, but also as a powerful extension analytical tool. (Author)

  1. Efficient pulse compression for LPI waveforms based on a nonparametric iterative adaptive approach

    Science.gov (United States)

    Li, Zhengzheng; Nepal, Ramesh; Zhang, Yan; Blake, WIlliam

    2015-05-01

    In order to achieve low probability-of-intercept (LPI), radar waveforms are usually long and randomly generated. Due to the randomized nature, Matched filter responses (autocorrelation) of those waveforms can have high sidelobes which would mask weaker targets near a strong target, limiting radar's ability to distinguish close-by targets. To improve resolution and reduced sidelobe contaminations, a waveform independent pulse compression filter is desired. Furthermore, the pulse compression filter needs to be able to adapt to received signal to achieve optimized performance. As many existing pulse techniques require intensive computation, real-time implementation is infeasible. This paper introduces a new adaptive pulse compression technique for LPI waveforms that is based on a nonparametric iterative adaptive approach (IAA). Due to the nonparametric nature, no parameter tuning is required for different waveforms. IAA can achieve super-resolution and sidelobe suppression in both range and Doppler domains. Also it can be extended to directly handle the matched filter (MF) output (called MF-IAA), which further reduces the computational load. The practical impact of LPI waveform operations on IAA and MF-IAA has not been carefully studied in previous work. Herein the typical LPI waveforms such as random phase coding and other non- PI waveforms are tested with both single-pulse and multi-pulse IAA processing. A realistic airborne radar simulator as well as actual measured radar data are used for the validations. It is validated that in spite of noticeable difference with different test waveforms, the IAA algorithms and its improvement can effectively achieve range-Doppler super-resolution in realistic data.

  2. Waveform Inversion with Source Encoding for Breast Sound Speed Reconstruction in Ultrasound Computed Tomography

    CERN Document Server

    Wang, Kun; Anis, Fatima; Li, Cuiping; Duric, Neb; Anastasio, Mark A

    2015-01-01

    Ultrasound computed tomography (USCT) holds great promise for improving the detection and management of breast cancer. Because they are based on the acoustic wave equation, waveform inversion-based reconstruction methods can produce images that possess improved spatial resolution properties over those produced by ray-based methods. However, waveform inversion methods are computationally demanding and have not been applied widely in USCT breast imaging. In this work, source encoding concepts are employed to develop an accelerated USCT reconstruction method that circumvents the large computational burden of conventional waveform inversion methods. This method, referred to as the waveform inversion with source encoding (WISE) method, encodes the measurement data using a random encoding vector and determines an estimate of the sound speed distribution by solving a stochastic optimization problem by use of a stochastic gradient descent algorithm. Both computer-simulation and experimental phantom studies are conduc...

  3. Advanced virtual energy simulation training and research: IGCC with CO2 capture power plant

    Energy Technology Data Exchange (ETDEWEB)

    Zitney, S.; Liese, E.; Mahapatra, P.; Bhattacharyya, D.; Provost, G.

    2011-01-01

    In this presentation, we highlight the deployment of a real-time dynamic simulator of an integrated gasification combined cycle (IGCC) power plant with CO{sub 2} capture at the Department of Energy's (DOE) National Energy Technology Laboratory's (NETL) Advanced Virtual Energy Simulation Training and Research (AVESTARTM) Center. The Center was established as part of the DOE's accelerating initiative to advance new clean coal technology for power generation. IGCC systems are an attractive technology option, generating low-cost electricity by converting coal and/or other fuels into a clean synthesis gas mixture in a process that is efficient and environmentally superior to conventional power plants. The IGCC dynamic simulator builds on, and reaches beyond, conventional power plant simulators to merge, for the first time, a 'gasification with CO{sub 2} capture' process simulator with a 'combined-cycle' power simulator. Fueled with coal, petroleum coke, and/or biomass, the gasification island of the simulated IGCC plant consists of two oxygen-blown, downward-fired, entrained-flow, slagging gasifiers with radiant syngas coolers and two-stage sour shift reactors, followed by a dual-stage acid gas removal process for CO{sub 2} capture. The combined cycle island consists of two F-class gas turbines, steam turbine, and a heat recovery steam generator with three-pressure levels. The dynamic simulator can be used for normal base-load operation, as well as plant start-up and shut down. The real-time dynamic simulator also responds satisfactorily to process disturbances, feedstock blending and switchovers, fluctuations in ambient conditions, and power demand load shedding. In addition, the full-scope simulator handles a wide range of abnormal situations, including equipment malfunctions and failures, together with changes initiated through actions from plant field operators. By providing a comprehensive IGCC operator training system, the

  4. Simulation of fission products behavior in severe accidents for advanced passive PWR

    International Nuclear Information System (INIS)

    Highlights: • A fission product analysis model based on thermal hydraulic module is developed. • An assessment method for fission product release and transport is constructed. • Fission products behavior during three modes of containment response is investigated. • Source term results for the three modes of containment response are obtained. - Abstract: Fission product behavior for common Pressurized Water Reactor (PWR) has been studied for many years, and some analytical tools have developed. However, studies specifically on the behavior of fission products related to advanced passive PWR is scarce. In the current study, design characteristics of advanced passive PWR influencing fission product behavior are investigated. An integrated fission products analysis model based on a thermal hydraulic module is developed, and the assessment method for fission products release and transport for advanced passive PWR is constructed. Three modes of containment response are simulated, including intact containment, containment bypass and containment overpressure failure. Fission products release from the core and corium, fission products transport and deposition in the Reactor Coolant System (RCS), fission products transport and deposition in the containment considering fission products retention in the in-containment refueling water storage tank (IRWST) and in the secondary side of steam generators (SGs) are simulated. Source term results of intact containment, containment bypass and containment overpressure failure are obtained, which can be utilized to evaluate the radiological consequences

  5. The importance of simulation facilities for the development of review criteria for advanced human system interfaces

    International Nuclear Information System (INIS)

    Advanced control room (ACR) concepts are being developed in the commercial nuclear industry as part of future reactor designs. The ACRs will use advanced human-system interface (HSI) technologies that may have significant implications for plant safety in that they will affect the operator's overall role (function) in the system, the method of information presentation, the ways in which the operator interacts with the system, and the requirements on the operator to understand and supervise an increasingly complex system. The U.S. Nuclear Regulatory Commission (NRC) reviews the HSI aspects of control rooms to ensure that they are designed to good human factors engineering principles and that operator performance and reliability are appropriately supported to protect public health and safety. The NRC is developing guidelines to support their review of these advanced designs. As part of this effort, a methodology for guidance development was established, and topics in need of further research were identified. Simulators of various kinds are likely to play important roles in the development of review guidelines and in the evaluation of ACRs. This paper describes a general approach to review criteria development, and discusses the role of simulators in addressing research needs

  6. Analysis of PV Advanced Inverter Functions and Setpoints under Time Series Simulation.

    Energy Technology Data Exchange (ETDEWEB)

    Seuss, John [Georgia Inst. of Technology, Atlanta, GA (United States); Reno, Matthew J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Broderick, Robert Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Grijalva, Santiago [Georgia Inst. of Technology, Atlanta, GA (United States)

    2016-05-01

    Utilities are increasingly concerned about the potential negative impacts distributed PV may have on the operational integrity of their distribution feeders. Some have proposed novel methods for controlling a PV system's grid - tie inverter to mitigate poten tial PV - induced problems. This report investigates the effectiveness of several of these PV advanced inverter controls on improving distribution feeder operational metrics. The controls are simulated on a large PV system interconnected at several locations within two realistic distribution feeder models. Due to the time - domain nature of the advanced inverter controls, quasi - static time series simulations are performed under one week of representative variable irradiance and load data for each feeder. A para metric study is performed on each control type to determine how well certain measurable network metrics improve as a function of the control parameters. This methodology is used to determine appropriate advanced inverter settings for each location on the f eeder and overall for any interconnection location on the feeder.

  7. Selection of Carrier Waveforms for PWM Inverter

    Institute of Scientific and Technical Information of China (English)

    陈国呈; 屈克庆; 许春雨; 孙承波

    2003-01-01

    In this paper the influence of different carrier waveforms upon the output characteristics of PWM inverter is described in detail. When a triangular carrier waveform is used in hard-switching PWM inverters, harmonics exist in the neighborhood of the output frequency of the inverter output voltage and current due to the dead time. The triangular carrier waveform used in soft-switching PWM inverter will cause difficulties in controlling resonance-trigger time, higher loss in the resonant circuit, and less utilization of the DC bus voltage. If a sawtooth carrier is used in hard-switching PWM inverter, there will be severe distortion in the current waveform. When sawtooth carriers with alternate positive and negative slopes are used in soft-switching PWM inverters, the resonancetrigger time is easy to control, and distortion in the output voltage and current caused by the dead time will not appear.

  8. GRC GSFC TDRSS Waveform Metrics Report

    Science.gov (United States)

    Mortensen, Dale J.

    2013-01-01

    The report presents software metrics and porting metrics for the GGT Waveform. The porting was from a ground-based COTS SDR, the SDR-3000, to the CoNNeCT JPL SDR. The report does not address any of the Operating Environment (OE) software development, nor the original TDRSS waveform development at GSFC for the COTS SDR. With regard to STRS, the report presents compliance data and lessons learned.

  9. Measuring venous oxygenation using the photoplethysmograph waveform

    OpenAIRE

    Walton, Z. D.; Kyriacou, P. A.; Silverman, D. G.; Shelley, K. H.

    2010-01-01

    OBJECTIVE: We investigate the hypothesis that the photoplethysmograph (PPG) waveform can be analyzed to infer regional venous oxygen saturation. METHODS: Fundamental to the successful isolation of the venous saturation is the identification of PPG characteristics that are unique to the peripheral venous system. Two such characteristics have been identified. First, the peripheral venous waveform tends to reflect atrial contraction. Second, ventilation tends to move venous blood preferenti...

  10. Improving advanced cardiovascular life support skills in medical students: simulation-based education approach

    Directory of Open Access Journals (Sweden)

    Hamidreza Reihani

    2015-01-01

    Full Text Available Objective: In this trial, we intend to assess the effect of simulation-based education approach on advanced cardiovascular life support skills among medical students. Methods: Through convenient sampling method, 40 interns of Mashhad University of Medical Sciences in their emergency medicine rotation (from September to December 2012 participated in this study. Advanced Cardiovascular Life Support (ACLS workshops with pretest and post-test exams were performed. Workshops and checklists for pretest and post-test exams were designed according to the latest American Heart Association (AHA guidelines. Results: The total score of the students increased significantly after workshops (24.6 out of 100 to 78.6 out of 100. This demonstrates 53.9% improvement in the skills after the simulation-based education (P< 0.001. Also the mean score of each station had a significant improvement (P< 0.001. Conclusion: Pretests showed that interns had poor performance in practical clinical matters while their scientific knowledge, such as ECG interpretation was acceptable. The overall results of the study highlights that Simulation based-education approach is highly effective in Improving ACLS skills among medical students.

  11. Development of an advanced thermal hydraulics model for nuclear power plant simulation

    International Nuclear Information System (INIS)

    This paper summarizes the development of an advanced digital computer thermal hydraulics model for nuclear power plant simulation. A review of thermal hydraulics code design options is presented together with a review of existing engineering models. CAE has developed an unequal temperatures-unequal velocities five equation model based on the drift flux formalism. CAE has selected the model on the basis that phase separation and thermal non-equilibrium are required to simulate complex and important phenomena occurring in systems such as reactor cooling systems (RCS) and steam generators (SG). The drift flux approach to phase separation and countercurrent flow was selected because extensive testing and validation data supports full-range drift flux parameters correlations. The five equation model was also chosen because it conserves important quantities, i.e. mass and energy of each phase, and because of numerical advantages provided by the case of coupling phasic mass conservation equations with phasic energy conservation equations. The basis of CAE's model as well as supporting models for convection and conduction heat transfer, break flow, interphase mass and heat transfer are described. Comparison of code calculations with experimental measurements taken during a small break LOCA test with the OTIS facility are presented. The use of such advanced thermal hydraulics model as plant analyzer considerably improves simulation capabilities of severe transient as well as of normal operation of two phase systems in nuclear power plants. (orig./HP)

  12. Towards Higher Resolution Global Mantle Waveform Tomography

    Science.gov (United States)

    Shulgin, A. A.; Romanowicz, B.

    2005-12-01

    Over the last 10 years, we have developed several generations of three-dimensional elastic and anelastic models of the earth's mantle, based on the inversion of surface and body waveforms using an asymptotic normal mode coupling approach (NACT, Li and Romanowicz, 1996). Until now, the shortest period of analysis of the body waveforms was 32 sec, and we have assumed standard scaling relations between compressional and shear velocities to obtain isotropic and radially anisotropic models of the whole mantle. We have found, surprisingly, that our waveforms have some - albeit weak - ability to resolve the topography of major mantle discontinuities. In order to improve the resolution of our models, extract P velocity information, as well as obtain better constraints on discontinuity topography, it is necessary to extend the analysis to shorter periods. This presents some computational challenges, as the number of coupling terms that need to be included increases rapidly with frequency. It also leads us to rethink our data selection strategy, in particular to allow larger time shifts between observed waveforms and synthetic ones. The latter are computed for a reference earth model and used in an automatic pre-selection step. We present progress in the development of a 3D elastic mantle model based on three component body waveforms down to 16 sec and surface waveforms down to 60 sec.

  13. Simulation for Supporting Scale-Up of a Fluidized Bed Reactor for Advanced Water Oxidation

    Directory of Open Access Journals (Sweden)

    Farhana Tisa

    2014-01-01

    Full Text Available Simulation of fluidized bed reactor (FBR was accomplished for treating wastewater using Fenton reaction, which is an advanced oxidation process (AOP. The simulation was performed to determine characteristics of FBR performance, concentration profile of the contaminants, and various prominent hydrodynamic properties (e.g., Reynolds number, velocity, and pressure in the reactor. Simulation was implemented for 2.8 L working volume using hydrodynamic correlations, continuous equation, and simplified kinetic information for phenols degradation as a model. The simulation shows that, by using Fe3+ and Fe2+ mixtures as catalyst, TOC degradation up to 45% was achieved for contaminant range of 40–90 mg/L within 60 min. The concentration profiles and hydrodynamic characteristics were also generated. A subsequent scale-up study was also conducted using similitude method. The analysis shows that up to 10 L working volume, the models developed are applicable. The study proves that, using appropriate modeling and simulation, data can be predicted for designing and operating FBR for wastewater treatment.

  14. Simulation for supporting scale-up of a fluidized bed reactor for advanced water oxidation.

    Science.gov (United States)

    Tisa, Farhana; Raman, Abdul Aziz Abdul; Daud, Wan Mohd Ashri Wan

    2014-01-01

    Simulation of fluidized bed reactor (FBR) was accomplished for treating wastewater using Fenton reaction, which is an advanced oxidation process (AOP). The simulation was performed to determine characteristics of FBR performance, concentration profile of the contaminants, and various prominent hydrodynamic properties (e.g., Reynolds number, velocity, and pressure) in the reactor. Simulation was implemented for 2.8 L working volume using hydrodynamic correlations, continuous equation, and simplified kinetic information for phenols degradation as a model. The simulation shows that, by using Fe(3+) and Fe(2+) mixtures as catalyst, TOC degradation up to 45% was achieved for contaminant range of 40-90 mg/L within 60 min. The concentration profiles and hydrodynamic characteristics were also generated. A subsequent scale-up study was also conducted using similitude method. The analysis shows that up to 10 L working volume, the models developed are applicable. The study proves that, using appropriate modeling and simulation, data can be predicted for designing and operating FBR for wastewater treatment. PMID:25309949

  15. Experimental study and advanced CFD simulation of fire safety performance of building external wall insulation system

    Directory of Open Access Journals (Sweden)

    Yan Zhenghua

    2013-11-01

    Full Text Available Large scale fire tests of building external wall insulation system were conducted. In the experiment, thermal-couples were mounted to measure the insulation system surface temperature and the gas temperature inside rooms at the second and third floors. Photos were also taken during the fire tests. The measurement provides information of the ignition and fire spread of the external insulation system which consists of surface protection layer, glass fibre net, bonding thin layer, anchor and the load bearing wall. Comprehensive simulations of the fire tests were carried out using an advanced CFD fire simulation software Simtec (Simulation of Thermal Engineering Complex [1, 2], which is now released by Simtec Soft Sweden, with the turbulent flow, turbulent combustion, thermal radiation, soot formation, convective heat transfer, the fully coupled three dimensional heat transfer inside solid materials, the ‘burn-out' of the surface protection layer and the pyrolysis of the insulation layer, etc, all computed. The simulation is compared with experimental measurement for validation. The simulation well captured the burning and fire spread of the external insulation wall.

  16. Simulation study of detached plasmas by using advanced particle model and fluid model

    International Nuclear Information System (INIS)

    Fluid simulations and particle simulations are performed to understand the physics of detached plasmas in the tokamak divertor. Two dimensional fluid simulations show that detached divertor plasmas are formed for the high density operation in the W-shaped divertor configuration of JT-60U tokamak. Charge-exchange and recombination processes play important roles to cause the detachment. The asymmetry of inner-and-outer divertor plasmas is studied based on a fluid model, and the bifurcated nature of the asymmetry caused by the SOL current is found. Advanced particle simulations demonstrate that the ExB drift by the radial electric field in a SOL plasma causes the asymmetry of flow pattern and density profile. A detached plasma is formed in the divertor region from which the drift flows out, when the ratio of the ExB drift speed to the sound speed exceeds a threshold. Effects of the radial gradient including diamagnetic drift flow on SOL and divertor plasmas are also studied with the two-dimensional particle simulation. (author)

  17. The Nuclear Energy Advanced Modeling and Simulation Enabling Computational Technologies FY09 Report

    Energy Technology Data Exchange (ETDEWEB)

    Diachin, L F; Garaizar, F X; Henson, V E; Pope, G

    2009-10-12

    In this document we report on the status of the Nuclear Energy Advanced Modeling and Simulation (NEAMS) Enabling Computational Technologies (ECT) effort. In particular, we provide the context for ECT In the broader NEAMS program and describe the three pillars of the ECT effort, namely, (1) tools and libraries, (2) software quality assurance, and (3) computational facility (computers, storage, etc) needs. We report on our FY09 deliverables to determine the needs of the integrated performance and safety codes (IPSCs) in these three areas and lay out the general plan for software quality assurance to meet the requirements of DOE and the DOE Advanced Fuel Cycle Initiative (AFCI). We conclude with a brief description of our interactions with the Idaho National Laboratory computer center to determine what is needed to expand their role as a NEAMS user facility.

  18. Development of Computational Approaches for Simulation and Advanced Controls for Hybrid Combustion-Gasification Chemical Looping

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Abhinaya; Lou, Xinsheng; Neuschaefer, Carl; Chaudry, Majid; Quinn, Joseph

    2012-07-31

    This document provides the results of the project through September 2009. The Phase I project has recently been extended from September 2009 to March 2011. The project extension will begin work on Chemical Looping (CL) Prototype modeling and advanced control design exploration in preparation for a scale-up phase. The results to date include: successful development of dual loop chemical looping process models and dynamic simulation software tools, development and test of several advanced control concepts and applications for Chemical Looping transport control and investigation of several sensor concepts and establishment of two feasible sensor candidates recommended for further prototype development and controls integration. There are three sections in this summary and conclusions. Section 1 presents the project scope and objectives. Section 2 highlights the detailed accomplishments by project task area. Section 3 provides conclusions to date and recommendations for future work.

  19. Simulations of Failure via Three-Dimensional Cracking in Fuel Cladding for Advanced Nuclear Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Hongbing [Univ. of Texas, Austin, TX (United States); Bukkapatnam, Satish; Harimkar, Sandip; Singh, Raman; Bardenhagen, Scott

    2014-01-09

    Enhancing performance of fuel cladding and duct alloys is a key means of increasing fuel burnup. This project will address the failure of fuel cladding via three-dimensional cracking models. Researchers will develop a simulation code for the failure of the fuel cladding and validate the code through experiments. The objective is to develop an algorithm to determine the failure of fuel cladding in the form of three-dimensional cracking due to prolonged exposure under varying conditions of pressure, temperature, chemical environment, and irradiation. This project encompasses the following tasks: 1. Simulate 3D crack initiation and growth under instantaneous and/or fatigue loads using a new variant of the material point method (MPM); 2. Simulate debonding of the materials in the crack path using cohesive elements, considering normal and shear traction separation laws; 3. Determine the crack propagation path, considering damage of the materials incorporated in the cohesive elements to allow the energy release rate to be minimized; 4. Simulate the three-dimensional fatigue crack growth as a function of loading histories; 5. Verify the simulation code by comparing results to theoretical and numerical studies available in the literature; 6. Conduct experiments to observe the crack path and surface profile in unused fuel cladding and validate against simulation results; and 7. Expand the adaptive mesh refinement infrastructure parallel processing environment to allow adaptive mesh refinement at the 3D crack fronts and adaptive mesh merging in the wake of cracks. Fuel cladding is made of materials such as stainless steels and ferritic steels with added alloying elements, which increase stability and durability under irradiation. As fuel cladding is subjected to water, chemicals, fission gas, pressure, high temperatures, and irradiation while in service, understanding performance is essential. In the fast fuel used in advanced burner reactors, simulations of the nuclear

  20. Simulations of Failure via Three-Dimensional Cracking in Fuel Cladding for Advanced Nuclear Fuels

    International Nuclear Information System (INIS)

    Enhancing performance of fuel cladding and duct alloys is a key means of increasing fuel burnup. This project will address the failure of fuel cladding via three-dimensional cracking models. Researchers will develop a simulation code for the failure of the fuel cladding and validate the code through experiments. The objective is to develop an algorithm to determine the failure of fuel cladding in the form of three-dimensional cracking due to prolonged exposure under varying conditions of pressure, temperature, chemical environment, and irradiation. This project encompasses the following tasks: 1. Simulate 3D crack initiation and growth under instantaneous and/or fatigue loads using a new variant of the material point method (MPM); 2. Simulate debonding of the materials in the crack path using cohesive elements, considering normal and shear traction separation laws; 3. Determine the crack propagation path, considering damage of the materials incorporated in the cohesive elements to allow the energy release rate to be minimized; 4. Simulate the three-dimensional fatigue crack growth as a function of loading histories; 5. Verify the simulation code by comparing results to theoretical and numerical studies available in the literature; 6. Conduct experiments to observe the crack path and surface profile in unused fuel cladding and validate against simulation results; and 7. Expand the adaptive mesh refinement infrastructure parallel processing environment to allow adaptive mesh refinement at the 3D crack fronts and adaptive mesh merging in the wake of cracks. Fuel cladding is made of materials such as stainless steels and ferritic steels with added alloying elements, which increase stability and durability under irradiation. As fuel cladding is subjected to water, chemicals, fission gas, pressure, high temperatures, and irradiation while in service, understanding performance is essential. In the fast fuel used in advanced burner reactors, simulations of the nuclear

  1. Simulation Research on Neutron Guide System CNGC for China Advanced Research Reactor

    Institute of Scientific and Technical Information of China (English)

    WEI; Guo-hai; HAN; Song-bai; HE; Lin-feng; WANG; Yu; WANG; Hong-li; LIU; Yun-tao; CHEN; Dong-feng; ZHAO; Zhi-xiang

    2012-01-01

    <正>The out-pile section of the neutron guide CNGC at CARR (China Advanced Research Reactor) was designed by Monte Carlo simulation with VITESS. The out-pile section of CNGC will be spitted to CNGC-S and CNGC-N, the cold neutron imaging facility and small angle neutron scattering facility will be installed at the end of guides respectively. XRD patterns of Bi1-xLaxFe1-yScyO3 were shown in Fig. 1.

  2. Advanced modeling and simulation of integrated gasification combined cycle power plants with CO2-capture

    International Nuclear Information System (INIS)

    The objective of this thesis is to provide an extensive description of the correlations in some of the most crucial sub-processes for hard coal fired IGCC with carbon capture (CC-IGCC). For this purpose, process simulation models are developed for four industrial gasification processes, the CO-shift cycle, the acid gas removal unit, the sulfur recovery process, the gas turbine, the water-/steam cycle and the air separation unit (ASU). Process simulations clarify the influence of certain boundary conditions on plant operation, performance and economics. Based on that, a comparative benchmark of CC-IGCC concepts is conducted. Furthermore, the influence of integration between the gas turbine and the ASU is analyzed in detail. The generated findings are used to develop an advanced plant configuration with improved economics. Nevertheless, IGCC power plants with carbon capture are not found to be an economically efficient power generation technology at present day boundary conditions.

  3. 3rd International Workshop on Advances in Simulation-Driven Optimization and Modeling

    CERN Document Server

    Leifsson, Leifur; Yang, Xin-She

    2016-01-01

    This edited volume is devoted to the now-ubiquitous use of computational models across most disciplines of engineering and science, led by a trio of world-renowned researchers in the field. Focused on recent advances of modeling and optimization techniques aimed at handling computationally-expensive engineering problems involving simulation models, this book will be an invaluable resource for specialists (engineers, researchers, graduate students) working in areas as diverse as electrical engineering, mechanical and structural engineering, civil engineering, industrial engineering, hydrodynamics, aerospace engineering, microwave and antenna engineering, ocean science and climate modeling, and the automotive industry, where design processes are heavily based on CPU-heavy computer simulations. Various techniques, such as knowledge-based optimization, adjoint sensitivity techniques, and fast replacement models (to name just a few) are explored in-depth along with an array of the latest techniques to optimize the...

  4. Motion-base simulator results of advanced supersonic transport handling qualities with active controls

    Science.gov (United States)

    Feather, J. B.; Joshi, D. S.

    1981-01-01

    Handling qualities of the unaugmented advanced supersonic transport (AST) are deficient in the low-speed, landing approach regime. Consequently, improvement in handling with active control augmentation systems has been achieved using implicit model-following techniques. Extensive fixed-based simulator evaluations were used to validate these systems prior to tests with full motion and visual capabilities on a six-axis motion-base simulator (MBS). These tests compared the handling qualities of the unaugmented AST with several augmented configurations to ascertain the effectiveness of these systems. Cooper-Harper ratings, tracking errors, and control activity data from the MBS tests have been analyzed statistically. The results show the fully augmented AST handling qualities have been improved to an acceptable level.

  5. Neural network setpoint control of an advanced test reactor experiment loop simulation

    Energy Technology Data Exchange (ETDEWEB)

    Cordes, G.A.; Bryan, S.R.; Powell, R.H.; Chick, D.R.

    1990-09-01

    This report describes the design, implementation, and application of artificial neural networks to achieve temperature and flow rate control for a simulation of a typical experiment loop in the Advanced Test Reactor (ATR) located at the Idaho National Engineering Laboratory (INEL). The goal of the project was to research multivariate, nonlinear control using neural networks. A loop simulation code was adapted for the project and used to create a training set and test the neural network controller for comparison with the existing loop controllers. The results for three neural network designs are documented and compared with existing loop controller action. The neural network was shown to be as accurate at loop control as the classical controllers in the operating region represented by the training set. 9 refs., 28 figs., 2 tabs.

  6. An adaptive transfer function for deriving the aortic pressure waveform from a peripheral artery pressure waveform.

    Science.gov (United States)

    Swamy, Gokul; Xu, Da; Olivier, N Bari; Mukkamala, Ramakrishna

    2009-11-01

    We developed a new technique to mathematically transform a peripheral artery pressure (PAP) waveform distorted by wave reflections into the physiologically more relevant aortic pressure (AP) waveform. First, a transfer function relating PAP to AP is defined in terms of the unknown parameters of a parallel tube model of pressure and flow in the arterial tree. The parameters are then estimated from the measured PAP waveform along with a one-time measurement of the wave propagation delay time between the aorta and peripheral artery measurement site (which may be accomplished noninvasively) by exploiting preknowledge of aortic flow. Finally, the transfer function with its estimated parameters is applied to the measured waveform so as to derive the AP waveform. Thus, in contrast to the conventional generalized transfer function, the transfer function is able to adapt to the intersubject and temporal variability of the arterial tree. To demonstrate the feasibility of this adaptive transfer function technique, we performed experiments in 6 healthy dogs in which PAP and reference AP waveforms were simultaneously recorded during 12 different hemodynamic interventions. The AP waveforms derived by the technique showed agreement with the measured AP waveforms (overall total waveform, systolic pressure, and pulse pressure root mean square errors of 3.7, 4.3, and 3.4 mmHg, respectively) statistically superior to the unprocessed PAP waveforms (corresponding errors of 8.6, 17.1, and 20.3 mmHg) and the AP waveforms derived by two previously proposed transfer functions developed with a subset of the same canine data (corresponding errors of, on average, 5.0, 6.3, and 6.7 mmHg). PMID:19783780

  7. Strategic Plan for Nuclear Energy -- Knowledge Base for Advanced Modeling and Simulation (NE-KAMS)

    Energy Technology Data Exchange (ETDEWEB)

    Kimberlyn C. Mousseau

    2011-10-01

    The Nuclear Energy Computational Fluid Dynamics Advanced Modeling and Simulation (NE-CAMS) system is being developed at the Idaho National Laboratory (INL) in collaboration with Bettis Laboratory, Sandia National Laboratory (SNL), Argonne National Laboratory (ANL), Utah State University (USU), and other interested parties with the objective of developing and implementing a comprehensive and readily accessible data and information management system for computational fluid dynamics (CFD) verification and validation (V&V) in support of nuclear energy systems design and safety analysis. The two key objectives of the NE-CAMS effort are to identify, collect, assess, store and maintain high resolution and high quality experimental data and related expert knowledge (metadata) for use in CFD V&V assessments specific to the nuclear energy field and to establish a working relationship with the U.S. Nuclear Regulatory Commission (NRC) to develop a CFD V&V database, including benchmark cases, that addresses and supports the associated NRC regulations and policies on the use of CFD analysis. In particular, the NE-CAMS system will support the Department of Energy Office of Nuclear Energy Advanced Modeling and Simulation (NEAMS) Program, which aims to develop and deploy advanced modeling and simulation methods and computational tools for reliable numerical simulation of nuclear reactor systems for design and safety analysis. Primary NE-CAMS Elements There are four primary elements of the NE-CAMS knowledge base designed to support computer modeling and simulation in the nuclear energy arena as listed below. Element 1. The database will contain experimental data that can be used for CFD validation that is relevant to nuclear reactor and plant processes, particularly those important to the nuclear industry and the NRC. Element 2. Qualification standards for data evaluation and classification will be incorporated and applied such that validation data sets will result in well

  8. Simulation of photoconductive antennas for terahertz radiation

    Directory of Open Access Journals (Sweden)

    C. A. Criollo

    2015-04-01

    Full Text Available Simulation of terahertz (THz emission based on PC antennas imposes a challenge to couple the semiconductor carrier phenomena, optical transport and the THz energy transport. In this paper a Multi-physics simulation for coupling these phenomena using COMSOL Multi-physics 4.3b is introduced. The main parameters of THz photoconductive (PC antenna as THz emitter have been reviewed and discussed. The results indicate the role of each parameter in the resulting photocurrent waveform and THz frequency: The radiated THz photocurrent waveform is determined by the photoconductive gap (the separation between the metallic electrodes, the incident laser illumination and the DC excitation voltage; while the THz frequency depends on the dipole length. The optimization of these parameters could enhance the emission. The simulations extend the advance of compact and cost-effective THz emitters.

  9. Current Advances in the Computational Simulation of the Formation of Low-Mass Stars

    Energy Technology Data Exchange (ETDEWEB)

    Klein, R I; Inutsuka, S; Padoan, P; Tomisaka, K

    2005-10-24

    Developing a theory of low-mass star formation ({approx} 0.1 to 3 M{sub {circle_dot}}) remains one of the most elusive and important goals of theoretical astrophysics. The star-formation process is the outcome of the complex dynamics of interstellar gas involving non-linear interactions of turbulence, gravity, magnetic field and radiation. The evolution of protostellar condensations, from the moment they are assembled by turbulent flows to the time they reach stellar densities, spans an enormous range of scales, resulting in a major computational challenge for simulations. Since the previous Protostars and Planets conference, dramatic advances in the development of new numerical algorithmic techniques have been successfully implemented on large scale parallel supercomputers. Among such techniques, Adaptive Mesh Refinement and Smooth Particle Hydrodynamics have provided frameworks to simulate the process of low-mass star formation with a very large dynamic range. It is now feasible to explore the turbulent fragmentation of molecular clouds and the gravitational collapse of cores into stars self-consistently within the same calculation. The increased sophistication of these powerful methods comes with substantial caveats associated with the use of the techniques and the interpretation of the numerical results. In this review, we examine what has been accomplished in the field and present a critique of both numerical methods and scientific results. We stress that computational simulations should obey the available observational constraints and demonstrate numerical convergence. Failing this, results of large scale simulations do not advance our understanding of low-mass star formation.

  10. Core library for advanced scenario simulation, C. L. A. S. S.: Principle and application

    International Nuclear Information System (INIS)

    The global warming, the increase of world population and the depletion of fossil resources have lead us in a major energy crisis. Using electronuclear energy could be one of the means to solve a part of these issues. The way out of this crisis may be enlightened by the study of transitional scenarios, guiding the political decisions. The reliability of those studies passes through the wide variety of the simulation tools and the comparison between them. From this perspective and in order to perform complex electronuclear scenario simulation, the open source Core Library for Advance Scenario Simulation (CLASS) is being developed. CLASS main asset is its ability to include any kind of reactor, whether the system is innovative or standard. A reactor is fully described by its evolution database that must contain a set of different fuel compositions in order to simulate transitional scenarios. CLASS aims at being a useful tool to study scenarios involving Generation IV reactors as well as innovative fuel cycles, like the Thorium cycle. The following contribution will present in detail the CLASS software. Starting with the working principle of this tool, one will explain the working process of the different modules such as the evolution module. It will be followed by an exhaustive presentation of the UOX-MOX bases generation procedure. Finally a brief analysis of the error made by the CLASS evolution module will be presented. (author)

  11. Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC).

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, Peter Andrew

    2011-12-01

    The objective of the U.S. Department of Energy Office of Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC) is to provide an integrated suite of computational modeling and simulation (M&S) capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive-waste storage facility or disposal repository. Achieving the objective of modeling the performance of a disposal scenario requires describing processes involved in waste form degradation and radionuclide release at the subcontinuum scale, beginning with mechanistic descriptions of chemical reactions and chemical kinetics at the atomic scale, and upscaling into effective, validated constitutive models for input to high-fidelity continuum scale codes for coupled multiphysics simulations of release and transport. Verification and validation (V&V) is required throughout the system to establish evidence-based metrics for the level of confidence in M&S codes and capabilities, including at the subcontiunuum scale and the constitutive models they inform or generate. This Report outlines the nature of the V&V challenge at the subcontinuum scale, an approach to incorporate V&V concepts into subcontinuum scale modeling and simulation (M&S), and a plan to incrementally incorporate effective V&V into subcontinuum scale M&S destined for use in the NEAMS Waste IPSC work flow to meet requirements of quantitative confidence in the constitutive models informed by subcontinuum scale phenomena.

  12. Advanced optical system simulation in a coupled CAD/optical analysis package

    Science.gov (United States)

    Stevenson, Michael A.; Campillo, Chris J.; Jenkins, David G.

    1999-05-01

    Software packages capable of simulating complex optical systems have the power to shorten the design process for non-imaging illumination, projection display, and other imaging illumination systems, Breault Research Organization's Advanced Systems Analysis Program (ASAP) and Robert McNeel and Associates' Rhinoceros computer aided design software, together, allow complicated optical systems to be simulated and analyzed. Through the use of Rhinoceros, an optical system can be accurately modeled in a 3D design environment. ASAP is then used to assign optical properties to the Rhinoceros CAD model. After the optical system has been characterized, it can be analyzed and optimized, by way of features specific to the ASAP optical analysis engine. Using this simulation technique, an HID arc source manufactured by Ushio America, Inc. is accurately represented. 2D CCD images are gathered for the source's emitting-volume across its spectral bandwidth. The images are processed within ASAP, via the inverse Abel command, to produce a 3D emitting-volume. This emitting-volume is combined with an accurate model of the source geometry and its optical properties, to finalize a functioning virtual source model. The characterized source is then joined with a simulated optical system for detailed performance analysis: namely, a projection display system.

  13. Advanced Simulation of Fuel Behavior Under Irradiation in the Pleiades Software Environment

    International Nuclear Information System (INIS)

    A “multi design” new generation software environment called PLEIADES has been developed by the CEA in the framework of a research cooperative program with EDF and AREVA. In this general software environment, ALCYONE is the PWR fuel performance simulation code. It is a multi-dimensional simulation software (1D, 2D and 3D), with applications for normal, transient and accidental conditions. It also has several levels of modelling, from industrial models to mechanistic ones depending on the amount of multi-scale details expected in the results of the simulation. The different dimensional schemes share the same thermomechanical Finite Element Method code CAST3M. The 1D scheme describes the behaviour of the whole rod and gives access to integral values such as rod fission gas release, clad profilometry and elongation. The 3D scheme allows a local study of Pellet Clad Mechanical Interaction (PCMI) by modelling the thermo-mechanical behaviour of one or several pellet fragments and overlying cladding. The 2D scheme is a compromise between calculation time and the accuracy of the local fuel description. Recently the 3D approach has been extended to a short fuel rod model in order to simulate the ballooning phenomenon during accidental transients. In this paper, we will present the general description of the ALCYONE simulation code in the PLEIADES environment (general computation algorithm, advanced fission gas model for UO2 and MOX fuels, 3D computation scheme). A focus will be presented on specific developments which have already been done to simulate accidental conditions such as LOCA and fast transients for different dimensional models. (author)

  14. Waveform feature extraction algorithms for IceCube

    International Nuclear Information System (INIS)

    The IceCube Neutrino Observatory at South Pole consists of digital optical modules (DOMs) deep down in the ice equipped with photomultipliers to capture Cherenkov light induced by muons and other particles. These DOMs digitize the analogue pulse shapes of the photomultiplier signals. The large amount of information has to be condensed for later particle track and energy reconstructions. This talk presents a new framework (the NewFeatureExtractor) to extract the arrival times and the number of photons. Three algorithms have been implemented in this framework to analyze different types of waveforms. Their performance is tested by comparison between experimental and simulated data and by comparison with earlier algorithms.

  15. Current waveforms for pulse microdischarge inside dielectric cell

    International Nuclear Information System (INIS)

    Computer simulation for microplasma discharge inside coplanar dielectric cell was carried out via particles in cells (PiC) method. Discharge current waveforms have a shape of short pulses with length decreasing and maximum earlier appearance for larger voltages applied. Mostly ion current on the negative coplanar electrode has a smooth shape contrary to the mostly electron current on the positive one which has a sharp maximum at the end of electron avalanche. Address electrode current is significantly less than coplanar electrodes currents and has pulsations corresponding to the striation structures appearance.

  16. Effect of non-linearity in predicting doppler waveforms through a novel model

    Directory of Open Access Journals (Sweden)

    Sengupta Amit

    2003-09-01

    Full Text Available Abstract Background In pregnancy, the uteroplacental vascular system develops de novo locally in utero and a systemic haemodynamic & bio-rheological alteration accompany it. Any abnormality in the non-linear vascular system is believed to trigger the onset of serious morbid conditions like pre-eclampsia and/or intrauterine growth restriction (IUGR. Exact Aetiopathogenesis is unknown. Advancement in the field of non-invasive doppler image analysis and simulation incorporating non-linearities may unfold the complexities associated with the inaccessible uteroplacental vessels. Earlier modeling approaches approximate it as a linear system. Method We proposed a novel electrical model for the uteroplacental system that uses MOSFETs as non-linear elements in place of traditional linear transmission line (TL model. The model to simulate doppler FVW's was designed by including the inputs from our non-linear mathematical model. While using the MOSFETs as voltage-controlled switches, a fair degree of controlled-non-linearity has been introduced in the model. Comparative analysis was done between the simulated data and the actual doppler FVW's waveforms. Results & Discussion Normal pregnancy has been successfully modeled and the doppler output waveforms are simulated for different gestation time using the model. It is observed that the dicrotic notch disappears and the S/D ratio decreases as the pregnancy matures. Both these results are established clinical facts. Effects of blood density, viscosity and the arterial wall elasticity on the blood flow velocity profile were also studied. Spectral analysis on the output of the model (blood flow velocity indicated that the Total Harmonic Distortion (THD falls during the mid-gestation. Conclusion Total harmonic distortion (THD is found to be informative in determining the Feto-maternal health. Effects of the blood density, the viscosity and the elasticity changes on the blood FVW are simulated. Future works are

  17. Advanced CFD simulation for the assessment of nuclear safety issues at EDF. Some examples

    International Nuclear Information System (INIS)

    EDF R and D has computer power that puts it amongst the top industrial research centers in the world. Its supercomputers and in-house codes as well as its experts represent important capabilities to support EDF activities (safety analyses, support to the design of new reactors, analysis of accidental situations non reproducible by experiments, better understanding of physics or complex system response, effects of uncertainties and identification of prominent parameters, qualification and optimization of processes and materials...). Advanced numerical simulation is a powerful tool allowing EDF to increase its competitiveness, improve its performance and the safety of its plants. On this issue, EDF made the choice to develop its own in-house codes, instead of using commercial software, in order to be able to capitalize its expertise and methodologies. This choice allowed as well easier technological transfer to the concerned business units or engineering divisions, fast adaptation of our simulation tools to emerging needs and the development of specific physics or functionalities not addressed by the commercial offer. During the last ten years, EDF has decided to open its in-house codes, through the Open Source way. This is the case for Code–Aster (structure analysis), Code–Saturne (computational fluid dynamics, CFD), TELEMAC (flow calculations in aquatic environment), SALOME (generic platform for Pre and Post-Processing) and SYRTHES (heat transfer in complex geometries), among others. The 3 open source software: Code–Aster, Code–Saturne and TELEMAC, are certified by the French Nuclear Regulatory Authority for many «Important to Safety» studies. Advanced simulation, which treats complex, multi-field and multi-physics problems, is of great importance for the assessment of nuclear safety issues. This paper will present 2 examples of advanced simulation using Code–Saturne for safety issues of nuclear power plants in the fields of R and D and engineering: 1

  18. A Tool for Satellite Communications: Advanced DVB-RCS / DVB-S2 System and Protocol Simulator

    OpenAIRE

    Boussemart, Vincent; Brandt, Hartmut

    2008-01-01

    A tool has been designed to simulate broadband satellite communication systems and techniques: a system and protocol simulator based on advanced DVB-RCS and DVB-S2 standards. As a powerful and flexible tool, it can be used to investigate and optimize current and future satellite communication systems, mainly to develop resource management algorithms and assess system performances. It is capable of simulating a satellite system using Ka-Band with multi-beam European coverage. It integrates rai...

  19. Colocated MIMO Radar: Beamforming, Waveform design, and Target Parameter Estimation

    KAUST Repository

    Jardak, Seifallah

    2014-04-01

    and Doppler shift. To assess the performance of the proposed estimators, the Cramér-Rao Lower Bound (CRLB) is derived. Simulation results show that the mean square estimation error of the proposed estimators achieve the CRLB. Keywords: Collocate antennas, multiple-input multiple-output (MIMO) radar, Finite alphabet waveforms, Hermite polynomials, Reflection coefficient, Doppler, Spatial location, Cramér-Rao Lower Bound.

  20. Krylov subspace acceleration of waveform relaxation

    Energy Technology Data Exchange (ETDEWEB)

    Lumsdaine, A.; Wu, Deyun [Univ. of Notre Dame, IN (United States)

    1996-12-31

    Standard solution methods for numerically solving time-dependent problems typically begin by discretizing the problem on a uniform time grid and then sequentially solving for successive time points. The initial time discretization imposes a serialization to the solution process and limits parallel speedup to the speedup available from parallelizing the problem at any given time point. This bottleneck can be circumvented by the use of waveform methods in which multiple time-points of the different components of the solution are computed independently. With the waveform approach, a problem is first spatially decomposed and distributed among the processors of a parallel machine. Each processor then solves its own time-dependent subsystem over the entire interval of interest using previous iterates from other processors as inputs. Synchronization and communication between processors take place infrequently, and communication consists of large packets of information - discretized functions of time (i.e., waveforms).

  1. Wavelet analysis of the impedance cardiogram waveforms

    Science.gov (United States)

    Podtaev, S.; Stepanov, R.; Dumler, A.; Chugainov, S.; Tziberkin, K.

    2012-12-01

    Impedance cardiography has been used for diagnosing atrial and ventricular dysfunctions, valve disorders, aortic stenosis, and vascular diseases. Almost all the applications of impedance cardiography require determination of some of the characteristic points of the ICG waveform. The ICG waveform has a set of characteristic points known as A, B, E ((dZ/dt)max) X, Y, O and Z. These points are related to distinct physiological events in the cardiac cycle. Objective of this work is an approbation of a new method of processing and interpretation of the impedance cardiogram waveforms using wavelet analysis. A method of computer thoracic tetrapolar polyrheocardiography is used for hemodynamic registrations. Use of original wavelet differentiation algorithm allows combining filtration and calculation of the derivatives of rheocardiogram. The proposed approach can be used in clinical practice for early diagnostics of cardiovascular system remodelling in the course of different pathologies.

  2. Notes on the integration of numerical relativity waveforms

    CERN Document Server

    Reisswig, Christian

    2010-01-01

    A primary goal of numerical relativity is to provide estimates of the wave strain, $h$, from strong gravitational wave sources, to be used in detector templates. The simulations, however, typically measure waves in terms of gauge resilient quantities, such as the Weyl curvature component, $\\psi_4$. Transforming to the strain requires integration of the measured variable twice in time. There are a number of fundamental difficulties which can arise from integrating finite length, discretely sampled and noisy data streams. These issues are related to the post-processing of the data, and thus independent of the characteristics of the original simulation, such as gauge or numerical method used. In particular, secular drifts in integrated waveforms have been observed empirically, but can also be studied with simple analytic models. We demonstrate that regardless of the nature of the original simulation, a degree of uncertainty will always be present in a strain which is calculated by integration. We suggest, howeve...

  3. Aligned spin neutron star-black hole mergers: a gravitational waveform amplitude model

    CERN Document Server

    Pannarale, Francesco; Kyutoku, Koutarou; Lackey, Benjamin D; Shibata, Masaru

    2015-01-01

    The gravitational radiation emitted during the merger of a black hole with a neutron star is rather similar to the radiation from the merger of two black holes when the neutron star is not tidally disrupted. When tidal disruption occurs, gravitational waveforms can be broadly classified in two groups, depending on the spatial extent of the disrupted material. Extending previous work by some of us, here we present a phenomenological model for the gravitational waveform amplitude in the frequency domain encompassing the three possible outcomes of the merger: no tidal disruption, "mild" and "strong" tidal disruption. The model is calibrated to 134 general-relativistic numerical simulations of binaries where the black hole spin is either aligned or antialigned with the orbital angular momentum. All simulations were produced using the SACRA code and piecewise polytropic neutron star equations of state. The present model can be used to determine when black-hole binary waveforms are sufficient for gravitational-wave...

  4. Signal processing in noise waveform radar

    CERN Document Server

    Kulpa, Krzysztof

    2013-01-01

    This book is devoted to the emerging technology of noise waveform radar and its signal processing aspects. It is a new kind of radar, which use noise-like waveform to illuminate the target. The book includes an introduction to basic radar theory, starting from classical pulse radar, signal compression, and wave radar. The book then discusses the properties, difficulties and potential of noise radar systems, primarily for low-power and short-range civil applications. The contribution of modern signal processing techniques to making noise radar practical are emphasized, and application examples

  5. Fractal Dimension of Voice-Signal Waveforms

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The fractal dimension is one important parameter that characterizes waveforms. In this paper, we derive a new method to calculate fractal dimension of digital voice-signal waveforms. We show that fractal dimension is an efficient tool for speaker recognition or speech recognition. It can be used to identify different speakers or distinguish speech. We apply our results to Chinese speaker recognition and numerical experiment shows that fractal dimension is an efficient parameter to characterize individual Chinese speakers. We have developed a semiautomatic voiceprint analysis system based on the theory of this paper and former researches.

  6. Principles of waveform diversity and design

    CERN Document Server

    Wicks, Michael

    2011-01-01

    This is the first book to discuss current and future applications of waveform diversity and design in subjects such as radar and sonar, communications systems, passive sensing, and many other technologies. Waveform diversity allows researchers and system designers to optimize electromagnetic and acoustic systems for sensing, communications, electronic warfare or combinations thereof. This book enables solutions to problems, explaining how each system performs its own particular function, as well as how it is affected by other systems and how those other systems may likewise be affected. It is

  7. The Waveform Suite: A robust platform for accessing and manipulating seismic waveforms in MATLAB

    Science.gov (United States)

    Reyes, C. G.; West, M. E.; McNutt, S. R.

    2009-12-01

    The Waveform Suite, developed at the University of Alaska Geophysical Institute, is an open-source collection of MATLAB classes that provide a means to import, manipulate, display, and share waveform data while ensuring integrity of the data and stability for programs that incorporate them. Data may be imported from a variety of sources, such as Antelope, Winston databases, SAC files, SEISAN, .mat files, or other user-defined file formats. The waveforms being manipulated in MATLAB are isolated from their stored representations, relieving the overlying programs from the responsibility of understanding the specific format in which data is stored or retrieved. The waveform class provides an object oriented framework that simplifies manipulations to waveform data. Playing with data becomes easier because the tedious aspects of data manipulation have been automated. The user is able to change multiple waveforms simultaneously using standard mathematical operators and other syntactically familiar functions. Unlike MATLAB structs or workspace variables, the data stored within waveform class objects are protected from modification, and instead are accessed through standardized functions, such as get and set; these are already familiar to users of MATLAB’s graphical features. This prevents accidental or nonsensical modifications to the data, which in turn simplifies troubleshooting of complex programs. Upgrades to the internal structure of the waveform class are invisible to applications which use it, making maintenance easier. We demonstrate the Waveform Suite’s capabilities on seismic data from Okmok and Redoubt volcanoes. Years of data from Okmok were retrieved from Antelope and Winston databases. Using the Waveform Suite, we built a tremor-location program. Because the program was built on the Waveform Suite, modifying it to operate on real-time data from Redoubt involved only minimal code changes. The utility of the Waveform Suite as a foundation for large

  8. Advanced Maintenance Simulation by Means of Hand-Based Haptic Interfaces

    Science.gov (United States)

    Nappi, Michele; Paolino, Luca; Ricciardi, Stefano; Sebillo, Monica; Vitiello, Giuliana

    Aerospace industry has been involved in virtual simulation for design and testing since the birth of virtual reality. Today this industry is showing a growing interest in the development of haptic-based maintenance training applications, which represent the most advanced way to simulate maintenance and repair tasks within a virtual environment by means of a visual-haptic approach. The goal is to allow the trainee to experiment the service procedures not only as a workflow reproduced at a visual level but also in terms of the kinaesthetic feedback involved with the manipulation of tools and components. This study, conducted in collaboration with aerospace industry specialists, is aimed to the development of an immersive virtual capable of immerging the trainees into a virtual environment where mechanics and technicians can perform maintenance simulation or training tasks by directly manipulating 3D virtual models of aircraft parts while perceiving force feedback through the haptic interface. The proposed system is based on ViRstperson, a virtual reality engine under development at the Italian Center for Aerospace Research (CIRA) to support engineering and technical activities such as design-time maintenance procedure validation, and maintenance training. This engine has been extended to support haptic-based interaction, enabling a more complete level of interaction, also in terms of impedance control, and thus fostering the development of haptic knowledge in the user. The user’s “sense of touch” within the immersive virtual environment is simulated through an Immersion CyberForce® hand-based force-feedback device. Preliminary testing of the proposed system seems encouraging.

  9. Monte Carlo simulations of the vacuum performance of differential pumps at the Advanced Photon Source

    International Nuclear Information System (INIS)

    Monte Carlo computer simulations have been successfully applied in the design of vacuum systems. These simulations allow the user to check the vacuum performance without the need of making a prototype of the vacuum system. In this paper we demonstrate the effectiveness and aptitude of these simulations in the design of differential pumps for synchrotron radiation beamlines. Eventually a good number of the beamline front ends at the Advanced Photon Source (APS) will use differential pumps to protect the synchrotron storage ring vacuum. A Monte Carlo computer program is used to calculate the molecular flow transmission and pressure distribution across the differential pump. A differential pump system, which consists of two 170 l/s ion pumps with three conductance-limiting apertures, was previously tested on an APS insertion-device beamline front end. Pressure distribution measurements using controlled leaks demonstrated a pressure difference of over two decades across the differential pump. A new differential pump utilizes a fixed mask between two 170 l/s ion pumps. The fixed mask, which has a conical channel with a small cross section of 4.5x4.5 mm2 in the far end, is used in the beamline to confine the photon beam. Monte Carlo simulations indicate that this configuration with the fixed mask significantly improves the pressure reduction capability of the differential pump, to ∼3x10-5, within the operational range from ∼10-4 to 10-10 Torr. The lower end of pressure is limited by outgassing from front-end components and the higher end by the pumping ability of the ion pump. copyright 1996 American Institute of Physics

  10. Strategic Plan for Nuclear Energy -- Knowledge Base for Advanced Modeling and Simulation (NE-KAMS)

    International Nuclear Information System (INIS)

    NE-KAMS knowledge base will assist computational analysts, physics model developers, experimentalists, nuclear reactor designers, and federal regulators by: (1) Establishing accepted standards, requirements and best practices for V and V and UQ of computational models and simulations, (2) Establishing accepted standards and procedures for qualifying and classifying experimental and numerical benchmark data, (3) Providing readily accessible databases for nuclear energy related experimental and numerical benchmark data that can be used in V and V assessments and computational methods development, (4) Providing a searchable knowledge base of information, documents and data on V and V and UQ, and (5) Providing web-enabled applications, tools and utilities for V and V and UQ activities, data assessment and processing, and information and data searches. From its inception, NE-KAMS will directly support nuclear energy research, development and demonstration programs within the U.S. Department of Energy (DOE), including the Consortium for Advanced Simulation of Light Water Reactors (CASL), the Nuclear Energy Advanced Modeling and Simulation (NEAMS), the Light Water Reactor Sustainability (LWRS), the Small Modular Reactors (SMR), and the Next Generation Nuclear Power Plant (NGNP) programs. These programs all involve computational modeling and simulation (M and S) of nuclear reactor systems, components and processes, and it is envisioned that NE-KAMS will help to coordinate and facilitate collaboration and sharing of resources and expertise for V and V and UQ across these programs. In addition, from the outset, NE-KAMS will support the use of computational M and S in the nuclear industry by developing guidelines and recommended practices aimed at quantifying the uncertainty and assessing the applicability of existing analysis models and methods. The NE-KAMS effort will initially focus on supporting the use of computational fluid dynamics (CFD) and thermal hydraulics (T

  11. Strategic Plan for Nuclear Energy -- Knowledge Base for Advanced Modeling and Simulation (NE-KAMS)

    Energy Technology Data Exchange (ETDEWEB)

    Rich Johnson; Kimberlyn C. Mousseau; Hyung Lee

    2011-09-01

    NE-KAMS knowledge base will assist computational analysts, physics model developers, experimentalists, nuclear reactor designers, and federal regulators by: (1) Establishing accepted standards, requirements and best practices for V&V and UQ of computational models and simulations, (2) Establishing accepted standards and procedures for qualifying and classifying experimental and numerical benchmark data, (3) Providing readily accessible databases for nuclear energy related experimental and numerical benchmark data that can be used in V&V assessments and computational methods development, (4) Providing a searchable knowledge base of information, documents and data on V&V and UQ, and (5) Providing web-enabled applications, tools and utilities for V&V and UQ activities, data assessment and processing, and information and data searches. From its inception, NE-KAMS will directly support nuclear energy research, development and demonstration programs within the U.S. Department of Energy (DOE), including the Consortium for Advanced Simulation of Light Water Reactors (CASL), the Nuclear Energy Advanced Modeling and Simulation (NEAMS), the Light Water Reactor Sustainability (LWRS), the Small Modular Reactors (SMR), and the Next Generation Nuclear Power Plant (NGNP) programs. These programs all involve computational modeling and simulation (M&S) of nuclear reactor systems, components and processes, and it is envisioned that NE-KAMS will help to coordinate and facilitate collaboration and sharing of resources and expertise for V&V and UQ across these programs. In addition, from the outset, NE-KAMS will support the use of computational M&S in the nuclear industry by developing guidelines and recommended practices aimed at quantifying the uncertainty and assessing the applicability of existing analysis models and methods. The NE-KAMS effort will initially focus on supporting the use of computational fluid dynamics (CFD) and thermal hydraulics (T/H) analysis for M&S of nuclear

  12. A graphical simulator for teaching basic and advanced MR imaging techniques

    DEFF Research Database (Denmark)

    Hanson, Lars G

    2007-01-01

    for radiologists, radiographers, and technical staff alike, but it is notoriously challenging to explain spin dynamics by using traditional teaching tools. The author developed a freely available graphical simulator based on the Bloch equations to aid in the teaching of topics ranging from precession...... and relaxation to advanced concepts such as stimulated echoes, spin tagging, and k-space-methods. A graphical user interface provides the user with a three-dimensional view of spin isochromates that can be manipulated by selecting radiofrequency pulses and gradient events. Even complicated sequences can...... be visualized in an intuitive way. The cross-platform software is primarily designed for use in lectures, but is also useful for self studies and student assignments. Movies available at http://radiographics.rsnajnls.org/cgi/content/full/e27/DC1 ....

  13. Advanced Simulation and Computing Fiscal Year 2016 Implementation Plan, Version 0

    Energy Technology Data Exchange (ETDEWEB)

    McCoy, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Archer, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hendrickson, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-08-27

    The Stockpile Stewardship Program (SSP) is an integrated technical program for maintaining the safety, surety, and reliability of the U.S. nuclear stockpile. The SSP uses nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of experimental facilities and programs, and the computational capabilities to support these programs. The purpose of this IP is to outline key work requirements to be performed and to control individual work activities within the scope of work. Contractors may not deviate from this plan without a revised WA or subsequent IP.

  14. Advanced adaptive computational methods for Navier-Stokes simulations in rotorcraft aerodynamics

    Science.gov (United States)

    Stowers, S. T.; Bass, J. M.; Oden, J. T.

    1993-01-01

    A phase 2 research and development effort was conducted in area transonic, compressible, inviscid flows with an ultimate goal of numerically modeling complex flows inherent in advanced helicopter blade designs. The algorithms and methodologies therefore are classified as adaptive methods, which are error estimation techniques for approximating the local numerical error, and automatically refine or unrefine the mesh so as to deliver a given level of accuracy. The result is a scheme which attempts to produce the best possible results with the least number of grid points, degrees of freedom, and operations. These types of schemes automatically locate and resolve shocks, shear layers, and other flow details to an accuracy level specified by the user of the code. The phase 1 work involved a feasibility study of h-adaptive methods for steady viscous flows, with emphasis on accurate simulation of vortex initiation, migration, and interaction. Phase 2 effort focused on extending these algorithms and methodologies to a three-dimensional topology.

  15. Virtual charge state separator as an advanced tool coupling measurements and simulations

    Science.gov (United States)

    Yaramyshev, S.; Vormann, H.; Adonin, A.; Barth, W.; Dahl, L.; Gerhard, P.; Groening, L.; Hollinger, R.; Maier, M.; Mickat, S.; Orzhekhovskaya, A.

    2015-05-01

    A new low energy beam transport for a multicharge uranium beam will be built at the GSI High Current Injector (HSI). All uranium charge states coming from the new ion source will be injected into GSI heavy ion high current HSI Radio Frequency Quadrupole (RFQ), but only the design ions U4 + will be accelerated to the final RFQ energy. A detailed knowledge about injected beam current and emittance for pure design U4 + ions is necessary for a proper beam line design commissioning and operation, while measurements are possible only for a full beam including all charge states. Detailed measurements of the beam current and emittance are performed behind the first quadrupole triplet of the beam line. A dedicated algorithm, based on a combination of measurements and the results of advanced beam dynamics simulations, provides for an extraction of beam current and emittance values for only the U4 + component of the beam. The proposed methods and obtained results are presented.

  16. Photocatalytic Removal of Microcystin-LR by Advanced WO3-Based Nanoparticles under Simulated Solar Light

    Directory of Open Access Journals (Sweden)

    Chao Zhao

    2015-01-01

    Full Text Available A series of advanced WO3-based photocatalysts including CuO/WO3, Pd/WO3, and Pt/WO3 were synthesized for the photocatalytic removal of microcystin-LR (MC-LR under simulated solar light. In the present study, Pt/WO3 exhibited the best performance for the photocatalytic degradation of MC-LR. The MC-LR degradation can be described by pseudo-first-order kinetic model. Chloride ion (Cl− with proper concentration could enhance the MC-LR degradation. The presence of metal cations (Cu2+ and Fe3+ improved the photocatalytic degradation of MC-LR. This study suggests that Pt/WO3 photocatalytic oxidation under solar light is a promising option for the purification of water containing MC-LR.

  17. Investigation on the effect of beam divergence angle upon output waveform based on stimulated Brillouin scattering optical limiting

    Institute of Scientific and Technical Information of China (English)

    Hasi Wu-Li-Ji; Lu Huan-Huan; Gong Sheng; Fu Mei-Ling; Lin Zhi-Wei; Lin Dian-Yang; He Wei-Ming

    2009-01-01

    This paper investigates the effect of beam divergence angle on output waveform based on stimulated Brillouin scattering optical limiting. Output waveforms in the case of different pump divergence angles are numerically simulated,and validated in a Nd:YAG seed-injected laser system. The results indicate that a small pump divergence angle can lead to good interaction between pump and Stokes, and a platform can be easily realized in the transmitted waveform.In contrast, a peak followed by the platform appears when the divergence angle becomes large.

  18. Advanced Simulation and Computing: A Summary Report to the Director's Review

    Energy Technology Data Exchange (ETDEWEB)

    McCoy, M G; Peck, T

    2003-06-01

    It has now been three years since the Advanced Simulation and Computing Program (ASCI), as managed by Defense and Nuclear Technologies (DNT) Directorate, has been reviewed by this Director's Review Committee (DRC). Since that time, there has been considerable progress for all components of the ASCI Program, and these developments will be highlighted in this document and in the presentations planned for June 9 and 10, 2003. There have also been some name changes. Today, the Program is called ''Advanced Simulation and Computing,'' Although it retains the familiar acronym ASCI, the initiative nature of the effort has given way to sustained services as an integral part of the Stockpile Stewardship Program (SSP). All computing efforts at LLNL and the other two Defense Program (DP) laboratories are funded and managed under ASCI. This includes the so-called legacy codes, which remain essential tools in stockpile stewardship. The contract between the Department of Energy (DOE) and the University of California (UC) specifies an independent appraisal of Directorate technical work and programmatic management. Such represents the work of this DNT Review Committee. Beginning this year, the Laboratory is implementing a new review system. This process was negotiated between UC, the National Nuclear Security Administration (NNSA), and the Laboratory Directors. Central to this approach are eight performance objectives that focus on key programmatic and administrative goals. Associated with each of these objectives are a number of performance measures to more clearly characterize the attainment of the objectives. Each performance measure has a lead directorate and one or more contributing directorates. Each measure has an evaluation plan and has identified expected documentation to be included in the ''Assessment File''.

  19. Numerical Simulation of Polarity Characteristics of Vector Elastic Wave of Advanced Detection in the Roadway

    Directory of Open Access Journals (Sweden)

    Deng Shuaiqi

    2013-05-01

    Full Text Available The high-order staggering grid Finite-Difference (FD scheme based on first-order velocity-stress elastic wave equation has been deduced. The calculation method of PML boundary condition and stability condition established in this study can be used for numerical simulation of advanced detection of elastic wave in roadway, with the obtaining of high-precision seismogram. Then we systematically analyze the polarity of vector wave field in post-source observation system. The results indicate that the relationship between the vector wave field and the polarity of direct wave is related to reflection coefficient on the interface, while the polarity relationship between horizontal and vertical components of vector wave field is related to vertical position of the interface. During data processing for advanced detection of elastic waves, the sign of the reflection coefficient on the interface ahead can be determined based on the polarity relationship between reflected wave and direct wave from the seismograms; the soft and hard rock and other geological information on both sides of the interface is thus be determined. In addition, the direction of source wave depends on polarity relationship between horizontal and vertical components of reflected wave and is used to achieve the separation of up going and down going waves.

  20. Comprehensive support for nuclear decommissioning based on 3D simulation and advanced user interface technologies

    International Nuclear Information System (INIS)

    There is an increasing international focus on the need to optimise decommissioning strategies, driven by the anticipation of high costs and major effort for the decommissioning of nuclear facilities in the coming decades. The goals are to control and mitigate costs and negative impacts on workers, the general public, and the environment. The methods presently employed for many decommissioning tasks do not apply the latest advancements of science and technology. Therefore, there is growing interest in research and development into the adoption of novel techniques for improving safety, reducing costs, and increasing transparency. This paper provides a comprehensive overview of the authors' results from investigating how current and emerging technologies can be applied to enhance the international decommissioning strategy, focussing in particular on three-dimensional simulation, virtual reality, advanced user interfaces, mobile and wearable devices, and geographical information systems. Our results demonstrate that emerging technologies have great potential for supporting adoption of new instrumentation, improving data and knowledge management, optimising project plans, briefing and training field operators, and for communication, surveillance, and education in general. (author)

  1. Advances in direct numerical simulation for MHD modeling of free surface flows

    International Nuclear Information System (INIS)

    The utilization of FLiBe (LiF-BeF2) free-surface flow as a chamber protection scheme is considered in advanced nuclear fusion reactor. At the design of the nuclear fusion reactor from the viewpoint of thermofluid research, it would be very important to understand the influence of a magnetic field in turbulent free surface flow. On the other hand, turbulent free surface flow (called open channel flow) by direct numerical simulation (DNS) with non-deformable surface was first succeeded by imposing free-slip and non-slip conditions as velocity boundary conditions at the upper and lower, respectively. After that, the research by DNS has been advanced more, it has been clarified that turbulent structures generated from the lower wall travels to the free surface and affected the mechanism of heat and mass transfer at the free surface. The behavior of the structures is affected by the strong magnetic field in the nuclear fusion reactor. Therefore, a DNS of liquid film cooling in the nuclear fusion reactor is performed by authors, and the relations between a magnetic orientation and turbulent flow statistics are clearly observed. In this paper, the DNS result is introduced, and the trial turbulence modeling for MHD free-surface flow by using the DNS database is also discussed

  2. Gamma-gamma density and lithology tools simulation based on GEANT4 advanced low energy Compton scattering (GALECS) package

    International Nuclear Information System (INIS)

    Geophysical bore-hole data represent the physical properties of rocks, such as density and formation lithology, as a function of depth in a well. Properties of rocks are obtained from gamma ray transport logs. Transport of gamma rays, from a 137Cs point gamma source situated in a bore-hole tool, through rock media to detectors, has been simulated using a GEANT4 radiation transport code. The advanced Compton scattering concepts were used to gain better analyses about well formation. The simulation and understanding of advanced Compton scattering highly depends on how accurately the effects of Doppler broadening and Rayleigh scattering are taken into account. A Monte Carlo package that simulates the gamma-gamma well logging tools based on GEANT4 advanced low energy Compton scattering (GALECS).

  3. Analog circuit design designing waveform processing circuits

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    The fourth volume in the set Designing Waveform-Processing Circuits builds on the previous 3 volumes and presents a variety of analog non-amplifier circuits, including voltage references, current sources, filters, hysteresis switches and oscilloscope trigger and sweep circuitry, function generation, absolute-value circuits, and peak detectors.

  4. Cauchy-characteristic evolution and waveforms

    International Nuclear Information System (INIS)

    This paper investigates a new method for computing waveforms generated by independent sources. A global spacetime evolution algorithms based on the Cauchy initial-value approach is used for the bounded interior area and the same algorithm based on the characteristic hypersurfaces is used for the exterior region. Both methods are equated at the common interface

  5. Cauchy-characteristic evolution and waveforms

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, N.T. [Univ. of South Africa, Pretoria (South Africa); Holvorcem, P.R.; Matzner, R.A. [Univ. of Texas, Austin, TX (United States)]|[Pennsylvania State Univ., University Park, PA (United States)] [and others

    1997-09-01

    This paper investigates a new method for computing waveforms generated by independent sources. A global spacetime evolution algorithms based on the Cauchy initial-value approach is used for the bounded interior area and the same algorithm based on the characteristic hypersurfaces is used for the exterior region. Both methods are equated at the common interface.

  6. A transformer of closely spaced pulsed waveforms

    Science.gov (United States)

    Niedra, J.

    1970-01-01

    Passive circuit, using diodes, transistors, and magnetic cores, transforms the voltage of repetitive positive or negative pulses. It combines a pulse transformer with switching devices to effect a resonant flux reset and can transform various pulsed waveforms that have a nonzero average value and are relatively cosely spaced in time.

  7. Parameters Determination of Oscillatory Impulse Current Waveform

    Science.gov (United States)

    Sato, Shuji; Nishimura, Seisuke; Seki, Shingo

    This paper proposes numerical techniques to distil waveform parameters out of digitally measured data of oscillatory impulse current. The first method, to be used for liner circuit, based on a curve-fitting technique in which a smooth analytical curve is defined to fit the noise-superposed measured data. The waveform parameters are derived from the curve. The algorithm is examined its performance using a measured waveform data which is obtained from a circuit composed of linear elements only. It is not rare when impulse current is measured in a circuit with non-linear element, namely an arrester. After carefully observed behaviours of the circuit current when the non-linear element turns on and off, authors developed two algorithms capable to determine the parameters from the recorded data obtained from a circuit having a ZnO arrester. The developed algorithm processed the waveform data generated by TDG which is to be issued in 2009 as a part of IEC 61083-2. The details of the algorithm are to be demonstrated in the paper.

  8. Fast and Accurate Icepak-PSpice Co-Simulation of IGBTs under Short-Circuit with an Advanced PSpice Model

    DEFF Research Database (Denmark)

    Wu, Rui; Iannuzzo, Francesco; Wang, Huai;

    2014-01-01

    A basic problem in the IGBT short-circuit failure mechanism study is to obtain realistic temperature distribution inside the chip, which demands accurate electrical simulation to obtain power loss distribution as well as detailed IGBT geometry and material information. This paper describes an...... unprecedented fast and accurate approach to electro-thermal simulation of power IGBTs suitable to simulate normal as well as abnormal conditions based on an advanced physics-based PSpice model together with ANSYS/Icepak FEM thermal simulator in a closed loop. Through this approach, significantly faster...... simulation speed with respect to conventional double-physics simulations, together with very accurate results can be achieved. A case study is given which presents the detailed electrical and thermal simulation results of an IGBT module under short circuit conditions. Furthermore, thermal maps in the case of...

  9. Technology advancement for the ASCENDS mission using the ASCENDS CarbonHawk Experiment Simulator (ACES)

    Science.gov (United States)

    Obland, M. D.; Antill, C.; Browell, E. V.; Campbell, J. F.; CHEN, S.; Cleckner, C.; Dijoseph, M. S.; Harrison, F. W.; Ismail, S.; Lin, B.; Meadows, B. L.; Mills, C.; Nehrir, A. R.; Notari, A.; Prasad, N. S.; Kooi, S. A.; Vitullo, N.; Dobler, J. T.; Bender, J.; Blume, N.; Braun, M.; Horney, S.; McGregor, D.; Neal, M.; Shure, M.; Zaccheo, T.; Moore, B.; Crowell, S.; Rayner, P. J.; Welch, W.

    2013-12-01

    The ASCENDS CarbonHawk Experiment Simulator (ACES) is a NASA Langley Research Center project funded by NASA's Earth Science Technology Office that seeks to advance technologies critical to measuring atmospheric column carbon dioxide (CO2) mixing ratios in support of the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission. The technologies being advanced are: (1) multiple transmitter and telescope-aperture operations, (2) high-efficiency CO2 laser transmitters, (3) a high bandwidth detector and transimpedance amplifier (TIA), and (4) advanced algorithms for cloud and aerosol discrimination. The instrument architecture is being developed for ACES to operate on a high-altitude aircraft, and it will be directly scalable to meet the ASCENDS mission requirements. The above technologies are critical for developing an airborne simulator and spaceborne instrument with lower platform consumption of size, mass, and power, and with improved performance. This design employs several laser transmitters and telescope-apertures to demonstrate column CO2 retrievals with alignment of multiple laser beams in the far-field. ACES will transmit five laser beams: three from commercial lasers operating near 1.57-microns, and two from the Exelis atmospheric oxygen (O2) fiber laser amplifier system operating near 1.26-microns. The Master Oscillator Power Amplifier at 1.57-microns measures CO2 column concentrations using an Integrated-Path Differential Absorption (IPDA) lidar approach. O2 column amounts needed for calculating the CO2 mixing ratio will be retrieved using the Exelis laser system with a similar IPDA approach. The three aperture telescope design was built to meet the constraints of the Global Hawk high-altitude unmanned aerial vehicle (UAV). This assembly integrates fiber-coupled transmit collimators for all of the laser transmitters and fiber-coupled optical signals from the three telescopes to the aft optics and detector package. The detector

  10. Propulsion Simulations Using Advanced Turbulence Models with the Unstructured Grid CFD Tool, TetrUSS

    Science.gov (United States)

    Abdol-Hamid, Khaled S.; Frink, Neal T.; Deere, Karen A.; Pandya, Mohangna J.

    2004-01-01

    A computational investigation has been completed to assess the capability of TetrUSS for exhaust nozzle flows. Three configurations were chosen for this study (1) an axisymmetric supersonic jet, (2) a transonic axisymmetric boattail with solid sting operated at different Reynolds number and Mach number, and (3) an isolated non-axisymmetric nacelle with a supersonic cruise nozzle. These configurations were chosen because existing experimental data provided a means for measuring the ability of TetrUSS for simulating complex nozzle flows. The main objective of this paper is to validate the implementation of advanced two-equation turbulence models in the unstructured-grid CFD code USM3D for propulsion flow cases. USM3D is the flow solver of the TetrUSS system. Three different turbulence models, namely, Menter Shear Stress Transport (SST), basic k epsilon, and the Spalart-Allmaras (SA) are used in the present study. The results are generally in agreement with other implementations of these models in structured-grid CFD codes. Results indicate that USM3D provides accurate simulations for complex aerodynamic configurations with propulsion integration.

  11. The Synergy Between Total Scattering and Advanced Simulation Techniques: Quantifying Geopolymer Gel Evolution

    Energy Technology Data Exchange (ETDEWEB)

    White, Claire [Los Alamos National Laboratory; Bloomer, Breaunnah E. [Los Alamos National Laboratory; Provis, John L. [The University of Melbourne; Henson, Neil J. [Los Alamos National Laboratory; Page, Katharine L. [Los Alamos National Laboratory

    2012-05-16

    With the ever increasing demands for technologically advanced structural materials, together with emerging environmental consciousness due to climate change, geopolymer cement is fast becoming a viable alternative to traditional cements due to proven mechanical engineering characteristics and the reduction in CO2 emitted (approximately 80% less CO2 emitted compared to ordinary Portland cement). Nevertheless, much remains unknown regarding the kinetics of the molecular changes responsible for nanostructural evolution during the geopolymerization process. Here, in-situ total scattering measurements in the form of X-ray pair distribution function (PDF) analysis are used to quantify the extent of reaction of metakaolin/slag alkali-activated geopolymer binders, including the effects of various activators (alkali hydroxide/silicate) on the kinetics of the geopolymerization reaction. Restricting quantification of the kinetics to the initial ten hours of reaction does not enable elucidation of the true extent of the reaction, but using X-ray PDF data obtained after 128 days of reaction enables more accurate determination of the initial extent of reaction. The synergies between the in-situ X-ray PDF data and simulations conducted by multiscale density functional theory-based coarse-grained Monte Carlo analysis are outlined, particularly with regard to the potential for the X-ray data to provide a time scale for kinetic analysis of the extent of reaction obtained from the multiscale simulation methodology.

  12. A Modified Time Advancement Algorithm for Optimizing Channel Flow Analysis in Direct Numerical Simulation Method

    Directory of Open Access Journals (Sweden)

    E. Rajabi

    2014-01-01

    Full Text Available In this research a direct numerical simulation (DNS of turbulent flow is performed in a geometrically standard case like plane channel flow. Pseudo spectral (PS method is used due to geometry specifications and very high accuracy achieved despite relatively few grid points. A variable time-stepping algorithm is proposed which may reduce requirement of computational cost in simulation of such wall-bounded flow. Channel flow analysis is performed with both constant and varied time-step for 128 × 65×128 grid points. The time advancement is carried out by implicit third-order backward differentiation scheme for linear terms and explicit forward Euler for nonlinear convection term. PS method is used in Cartesian coordinates with Chebychev polynomial expansion in normal direction for one non-periodic boundary condition. Also Fourier series is employed in stream-wise and span-wise directions for two periodic boundary conditions. The friction Reynolds number is about Reτ=175 based on a friction velocity and channel half width. Standard common rotational form was chosen for discritization of nonlinear convective term of Navier-Stocks equation. The comparison is made between turbulent quantities such as the turbulent statistics, Reynolds stress, wall shear velocity, standard deviation of (u and total normalized energy of instantaneous velocities in both time-discretization methods. The results show that if final decision rests on economics, the proposed variable time-stepping algorithm will be proper choice which satisfies the accuracy and reduces the computational cost.

  13. Platform for Post-Processing Waveform-Based NDE

    Science.gov (United States)

    Roth, Don J.

    2010-01-01

    Signal- and image-processing methods are commonly needed to extract information from the waves, improve resolution of, and highlight defects in an image. Since some similarity exists for all waveform-based nondestructive evaluation (NDE) methods, it would seem that a common software platform containing multiple signal- and image-processing techniques to process the waveforms and images makes sense where multiple techniques, scientists, engineers, and organizations are involved. NDE Wave & Image Processor Version 2.0 software provides a single, integrated signal- and image-processing and analysis environment for total NDE data processing and analysis. It brings some of the most useful algorithms developed for NDE over the past 20 years into a commercial-grade product. The software can import signal/spectroscopic data, image data, and image series data. This software offers the user hundreds of basic and advanced signal- and image-processing capabilities including esoteric 1D and 2D wavelet-based de-noising, de-trending, and filtering. Batch processing is included for signal- and image-processing capability so that an optimized sequence of processing operations can be applied to entire folders of signals, spectra, and images. Additionally, an extensive interactive model-based curve-fitting facility has been included to allow fitting of spectroscopy data such as from Raman spectroscopy. An extensive joint-time frequency module is included for analysis of non-stationary or transient data such as that from acoustic emission, vibration, or earthquake data.

  14. Estimation of forest structure and canopy fuel parameters from small-footprint full-waveform LiDAR data

    OpenAIRE

    Hermosilla, T.; Ruiz Fernández, Luis Ángel

    2014-01-01

    Precise knowledge of fuel conditions is important for predicting fire hazards and simulating fire growth and intensity across the landscape. We present a methodology to retrieve and map forest canopy fuel and other forest structural parameters using small-footprint full-waveform airborne light detection and ranging (LiDAR) data. Full-waveform LiDAR sensors register the complete returned backscattered signal through time and can describe physical properties of the intercepted objects. This stu...

  15. An Analysis of the Accuracy of Electromechanical Eigenvalue Calculations Based on Instantaneous Power Waveforms Recorded in a Power Plant

    OpenAIRE

    Piotr Pruski; Stefan Paszek

    2013-01-01

    The paper presents the results of calculating the eigenvalues (associated with electromechanical phenomena) of the state matrix of the Polish Power System model on the basis of analysis of simulated and measured instantaneous power disturbance waveforms of generating units in Łaziska Power Plant. The method for electromechanical eigenvalue calculations used in investigations consists in approximation of the instantaneous power swing waveforms in particular generating units with the use of the...

  16. Full-waveform inversion on heterogeneous HPC systems

    Science.gov (United States)

    Gokhberg, Alexey; Fichtner, Andreas

    2016-04-01

    We present a spectral-element implementation of full seismic waveform inversion for large heterogeneous HPC systems. In this we address the optimal parallelisation configurations of individual simulations, the large I/O requirements of adjoint simulations, and the scheduling of large numbers of forward and adjoint solves, typical for realistic inversions. Using GPU accelerators allows us to achieve a 3.5-4 times performance improvement over the best known homogeneous implementation. We achieve GPU memory throughput varying from 60 to 80% of the peak bandwidth, thus providing good utilisation of hardware resources. We demonstrate the practical applicability of our developments in a real-data application in the western Mediterranean. With the help of GPU accelerators, we are able to model and invert seismic wave propagation in a frequency band that is broader than permitted by the use of CPUs alone, which helps bridging the traditional gap between crustal and mantle tomography.

  17. Seismic network detection probability assessment using waveforms and accounting to event association logic

    Science.gov (United States)

    Pinsky, Vladimir; Shapira, Avi

    2016-05-01

    The geographical area where a seismic event of magnitude M ≥ M t is detected by a seismic station network, for a defined probability is derived from a station probability of detection estimated as a function of epicentral distance. The latter is determined from both the bulletin data and the waveforms recorded by the station during the occurrence of the event with and without band-pass filtering. For simulating the real detection process, the waveforms are processed using the conventional Carl Johnson detection and association algorithm. The attempt is presented to account for the association time criterion in addition to the conventional approach adopted by the known PMC method.

  18. Performance Analysis of Mimo Radar Waveform Using Accelerated Particle Swarm Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    B. Roja Reddy

    2012-08-01

    Full Text Available The Accelerated Particle Swarm Optimization Algorithm is promoted to numerically design orthogonal Discrete Frequency Waveforms and Modified Discrete Frequency Waveforms (DFCWs with good correlation properties for MIMO radar. We employ Accelerated Particle Swarm Optimization algorithm (ACC_PSO, Particles of a swarm communicate good positions, velocity and accelerations to each other as well as dynamically adjust their own position, velocity and acceleration derived from the best of all particles. The simulation results show that the proposed algorithm is effective for the design of DFCWs signal used in MIMO radar.

  19. Imaging Algorithm for Rotor Synthetic Aperture Radar Using Stepped-frequency Waveform

    Directory of Open Access Journals (Sweden)

    Zeng Cao

    2014-08-01

    Full Text Available For ROtor Synthetic Aperture Radar (ROSAR using the stepped-frequency waveform, an imaging method based on Range Migration Correction (RMC for ROSAR is proposed. First, the signal model of ROSAR using stepped-frequency waveform is derived; Second, the range migration correction in frequency domain is proposed; Third, the high-resolution images are achieved by using the ω-k algorithm; Finally, the azimuth resolution performance is analyzed. Simulation results demonstrate the effectiveness and high resolution performance of the proposed method.

  20. SAR processing with non-linear FM chirp waveforms.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2006-12-01

    Nonlinear FM (NLFM) waveforms offer a radar matched filter output with inherently low range sidelobes. This yields a 1-2 dB advantage in Signal-to-Noise Ratio over the output of a Linear FM (LFM) waveform with equivalent sidelobe filtering. This report presents details of processing NLFM waveforms in both range and Doppler dimensions, with special emphasis on compensating intra-pulse Doppler, often cited as a weakness of NLFM waveforms.

  1. Accurate Waveforms for Non-spinning Binary Black Holes using the Effective-one-body Approach

    Science.gov (United States)

    Buonanno, Alessandra; Pan, Yi; Baker, John G.; Centrella, Joan; Kelly, Bernard J.; McWilliams, Sean T.; vanMeter, James R.

    2007-01-01

    Using numerical relativity as guidance and the natural flexibility of the effective-one-body (EOB) model, we extend the latter so that it can successfully match the numerical relativity waveforms of non-spinning binary black holes during the last stages of inspiral, merger and ringdown. Here, by successfully, we mean with phase differences black-hole masses. The final black-hole mass and spin predicted by the numerical simulations are used to determine the ringdown frequency and decay time of three quasi-normal-mode damped sinusoids that are attached to the EOB inspiral-(plunge) waveform at the light-ring. The accurate EOB waveforms may be employed for coherent searches of gravitational waves emitted by non-spinning coalescing binary black holes with ground-based laser-interferometer detectors.

  2. Error-analysis and comparison to analytical models of numerical waveforms produced by the NRAR Collaboration

    CERN Document Server

    Hinder, Ian; Boyle, Michael; Etienne, Zachariah B; Healy, James; Johnson-McDaniel, Nathan K; Nagar, Alessandro; Nakano, Hiroyuki; Pan, Yi; Pfeiffer, Harald P; Pürrer, Michael; Reisswig, Christian; Scheel, Mark A; Sperhake, Ulrich; Szilágyi, Bela; Tichy, Wolfgang; Wardell, Barry; Zenginoglu, Anıl; Alic, Daniela; Bernuzzi, Sebastiano; Bode, Tanja; Brügmann, Bernd; Buchman, Luisa T; Campanelli, Manuela; Chu, Tony; Damour, Thibault; Grigsby, Jason D; Hannam, Mark; Haas, Roland; Hemberger, Daniel A; Husa, Sascha; Kidder, Lawrence E; Laguna, Pablo; London, Lionel; Lovelace, Geoffrey; Lousto, Carlos O; Marronetti, Pedro; Matzner, Richard A; Mösta, Philipp; Mroué, Abdul; Müller, Doreen; Mundim, Bruno C; Nerozzi, Andrea; Paschalidis, Vasileios; Pollney, Denis; Reifenberger, George; Rezzolla, Luciano; Shapiro, Stuart L; Shoemaker, Deirdre; Taracchini, Andrea; Taylor, Nicholas W; Teukolsky, Saul A; Thierfelder, Marcus; Witek, Helvi; Zlochower, Yosef

    2014-01-01

    The Numerical-Relativity-Analytical-Relativity (NRAR) collaboration is a joint effort between members of the numerical relativity, analytical relativity and gravitational-wave data analysis communities. The goal of the NRAR collaboration is to produce numerical-relativity simulations of compact binaries and use them to develop accurate analytical templates for the LIGO/Virgo Collaboration to use in detecting gravitational-wave signals and extracting astrophysical information from them. We describe the results of the first stage of the NRAR project, which focused on producing an initial set of numerical waveforms from binary black holes with moderate mass ratios and spins, as well as one non-spinning binary configuration which has a mass ratio of 10. All of the numerical waveforms are analysed in a uniform and consistent manner, with numerical errors evaluated using an analysis code created by members of the NRAR collaboration. We compare previously-calibrated, non-precessing analytical waveforms, notably the ...

  3. MIMO-OFDM Chirp Waveform Diversity Design and Implementation Based on Sparse Matrix and Correlation Optimization

    Directory of Open Access Journals (Sweden)

    Wang Wen-qin

    2015-02-01

    Full Text Available The waveforms used in Multiple-Input Multiple-Output (MIMO Synthetic Aperture Radar (SAR should have a large time-bandwidth product and good ambiguity function performance. A scheme to design multiple orthogonal MIMO SAR Orthogonal Frequency Division Multiplexing (OFDM chirp waveforms by combinational sparse matrix and correlation optimization is proposed. First, the problem of MIMO SAR waveform design amounts to the associated design of hopping frequency and amplitudes. Then a iterative exhaustive search algorithm is adopted to optimally design the code matrix with the constraints minimizing the block correlation coefficient of sparse matrix and the sum of cross-correlation peaks. And the amplitudes matrix are adaptively designed by minimizing the cross-correlation peaks with the genetic algorithm. Additionally, the impacts of waveform number, hopping frequency interval and selectable frequency index are also analyzed. The simulation results verify the proposed scheme can design multiple orthogonal large time-bandwidth product OFDM chirp waveforms with low cross-correlation peak and sidelobes and it improves ambiguity performance.

  4. Discrete-event simulation of coordinated multi-point joint transmission in LTE-Advanced with constrained backhaul

    DEFF Research Database (Denmark)

    Artuso, Matteo; Christiansen, Henrik Lehrmann

    2014-01-01

    Inter-cell interference in LTE-Advanced can be mitigated using coordinated multi-point (CoMP) techniques with joint transmission of user data . However, this requires tight coordination of the eNodeBs, usin g the X2 interface. In this paper we use discrete-event simulation to evaluate the latency...

  5. Development of advanced spent fuel management process. The fabrication and oxidation behavior of simulated metallized spent fuel

    International Nuclear Information System (INIS)

    The simulated metallized spent fuel ingots were fabricated and evaluated the oxidation rates and the activation energies under several temperature conditions to develop an advanced spent fuel management process. It was also checked the alloying characteristics of the some elements with metal uranium. (Author). 3 refs., 1 tab., 36 figs

  6. ADVANCED SIMULATION CAPABILITY FOR ENVIRONMENTAL MANAGEMENT- CURRENT STATUS AND PHASE II DEMONSTRATION RESULTS

    Energy Technology Data Exchange (ETDEWEB)

    Seitz, R.

    2013-02-26

    The U.S. Department of Energy (USDOE) Office of Environmental Management (EM), Office of Soil and Groundwater, is supporting development of the Advanced Simulation Capability for Environmental Management (ASCEM). ASCEM is a state-of-the-art scientific tool and approach for understanding and predicting contaminant fate and transport in natural and engineered systems. The modular and open source high-performance computing tool facilitates integrated approaches to modeling and site characterization that enable robust and standardized assessments of performance and risk for EM cleanup and closure activities. The ASCEM project continues to make significant progress in development of computer software capabilities with an emphasis on integration of capabilities in FY12. Capability development is occurring for both the Platform and Integrated Toolsets and High-Performance Computing (HPC) Multiprocess Simulator. The Platform capabilities provide the user interface and tools for end-to-end model development, starting with definition of the conceptual model, management of data for model input, model calibration and uncertainty analysis, and processing of model output, including visualization. The HPC capabilities target increased functionality of process model representations, toolsets for interaction with Platform, and verification and model confidence testing. The Platform and HPC capabilities are being tested and evaluated for EM applications in a set of demonstrations as part of Site Applications Thrust Area activities. The Phase I demonstration focusing on individual capabilities of the initial toolsets was completed in 2010. The Phase II demonstration completed in 2012 focused on showcasing integrated ASCEM capabilities. For Phase II, the Hanford Site deep vadose zone (BC Cribs) served as an application site for an end-to-end demonstration of capabilities, with emphasis on integration and linkages between the Platform and HPC components. Other demonstrations

  7. Computer simulation of homogenization of boric acid in a pressurizer of the advanced nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, Jose E.P. da; Moreira, Maria de L., E-mail: jeduird@hotmail.com, E-mail: malu@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Oliveira, Andre F. de, E-mail: eafoliveira@ien.gov.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2013-07-01

    The reactivity of a water cooled reactor is controlled using control rods or boron dilution in water of the primary circuit. The boron-10 ({sup 10} B) is an efficient neutron absorber, especially when used in the absorption of thermal neutrons. Transient studies with disabilities in the homogenization of boron in PWR reactors become important as the boric acid solution is added to the primary circuit coolant in order to help control the fission rate in the reactor core. After reactor shutdown, the boron present in coolant has the function of maintaining reactor subcriticality. If low concentrated boron solution enters in the primary circuit, it becomes necessary to inject boron and to assure that the coolant will be well homogenized in order to increase the concentration and thus preventing water with small amounts of boron to reach the core. The aim of this study is to simulate the boron homogenization in the pressurizer of an advanced nuclear reactor. It is used a test section, which represents a quarter of a modular nuclear reactor pressurizer. By using the CFX code, a computer program that allows thermal hydraulic analysis of different types of flow, three examples were simulated using different operating conditions. With the results, it was analyzed the parameters that could influence this homogenization. Case studies such as variation of the dimensions of the water inlet and outlet tubes, flow variation and change in positioning of entrances and exits were made with the goal of finding parameters that could help the optimization of the homogenization of boron. The results confirm that the issues analyzed can be changed in the project in order to obtain the best operating condition. (author)

  8. SIROCCO project: 15 advanced instructor desk and 4 simulated control room for 900MW and 1300MW EDF power plant simulators

    International Nuclear Information System (INIS)

    This presentation describes the fifteen advanced instructors station and four simulated control delivered to EDF in the frame of the SIROCCO project by the Consortium formed by ATOS Origin, CORYS Tess, for the Electricite de France (EDF). These instructor stations are installed on fifteen replica training simulators located on different sites throughout France for the purposes of improving the job-related training of the EDF PWR nuclear power plant operating teams. This covers all 900 MW and 1300MW nuclear power plant of EDF. The simulated control rooms are installed on maintenance platform located at EDF and the consortium facilities. The consortium uses it to maintain and upgrade the simulators. EDF uses it to validate the upgrade delivered by the consortium before on site installation and to perform engineering analysis. This presentation sets out successively: - The major advantages of the generic and configurable connected module concept for flexible and quick adaptation to different simulators; - The innovative functionalities of the advanced Instructor Desk (IS) which make the instructor's tasks of preparation, monitoring and postanalysis of a training session easier and more homogeneous; - The use of the Simulated Control Room (SCR) for training purposes but also for those of maintenance and design studies for upgrades of existing control rooms

  9. Advanced Research and Education in Electrical Drives by Using Digital Real-Time Hardware-in-the-Loop Simulation

    DEFF Research Database (Denmark)

    Bojoi, R.; Profumo, F.; Griva, G.;

    2002-01-01

    The authors present in this paper a digital real-time hardware-in-the-loop simulation of a three-phase induction motor drive. The main real-time simulation tool is the dSPACE DS1103 PPC Controller Board which simulates the power and signal conditioning parts. The control algorithm of the virtual...... drive has been implemented on the Evaluation Board of TMS320F240 DSP. The experimental results validate this solution as a powerful tool to be used in research and advanced education. Thus, the students can put in practic the theory without spending too much time with details concerning the hardware...

  10. Programmable Clock Waveform Generation for CCD Readout

    Energy Technology Data Exchange (ETDEWEB)

    Vicente, J. de; Castilla, J.; Martinez, G.; Marin, J.

    2006-07-01

    Charge transfer efficiency in CCDs is closely related to the clock waveform. In this paper, an experimental framework to explore different FPGA based clock waveform generator designs is described. Two alternative design approaches for controlling the rise/fall edge times and pulse width of the CCD clock signal have been implemented: level-control and time-control. Both approaches provide similar characteristics regarding the edge linearity and noise. Nevertheless, dissimilarities have been found with respect to the area and frequency range of application. Thus, while the time-control approach consumes less area, the level control approach provides a wider range of clock frequencies since it does not suffer capacitor discharge effect. (Author) 8 refs.

  11. Clustering of Waveforms Based on FPCA Direction

    OpenAIRE

    Adelfio, Giada; Chiodi, Marcello; D'Alessandro, Antonino; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Luzio, Dario

    2010-01-01

    Abstract. Looking for curves similarity could be a complex issue characterized by subjective choices related to continuous transformations of observed discrete data (Chiodi, 1989). Waveforms correlation techniques have been introduced to charac- terize the degree of seismic event similarity (Menke, 1999) and in facilitating more accurate relative locations within similar event clusters by providing more precise timing of seismic wave (P and S) arrivals (Phillips, 1997). In t...

  12. Full-waveform inversion: Filling the gaps

    KAUST Repository

    Beydoun, Wafik B.

    2015-09-01

    After receiving an outstanding response to its inaugural workshop in 2013, SEG once again achieved great success with its 2015 SEG Middle East Workshop, “Full-waveform inversion: Filling the gaps,” which took place 30 March–1 April 2015 in Abu Dhabi, UAE. The workshop was organized by SEG, and its partner sponsors were Saudi Aramco (gold sponsor), ExxonMobil, and CGG. Read More: http://library.seg.org/doi/10.1190/tle34091106.1

  13. Best waveform score for diagnosing keratoconus

    OpenAIRE

    Allan Luz; Bruno Machado Fontes; Bernardo Lopes; Isaac Ramos; Fernando Faria Correia; Paulo Schor; Renato Ambrósio Jr.

    2013-01-01

    PURPOSE: To test whether corneal hysteresis (CH) and corneal resistance factor (CRF) can discriminate between keratoconus and normal eyes and to evaluate whether the averages of two consecutive measurements perform differently from the one with the best waveform score (WS) for diagnosing keratoconus. METHODS: ORA measurements for one eye per individual were selected randomly from 53 normal patients and from 27 patients with keratoconus. Two groups were considered the average (CH-Avg, CRF-Avg)...

  14. Performance experiments with alternative advanced teleoperator control modes for a simulated solar maximum satellite repair

    Science.gov (United States)

    Das, H.; Zak, H.; Kim, W. S.; Bejczy, A. K.; Schenker, P. S.

    1992-01-01

    Experiments are described which were conducted at the JPL Advanced Teleoperator Lab to demonstrate and evaluate the effectiveness of various teleoperator control modes in the performance of a simulated Solar Max Satellite Repair (SMSR) task. THe SMSR was selected as a test because it is very rich in performance capability requirements and it actually has been performed by two EVA astronauts in the Space Shuttle Bay in 1984. The main subtasks are: thermal blanket removal; installation of a hinge attachment for electrical panel opening; opening of electrical panel; removal of electrical connectors; relining of cable bundles; replacement of electrical panel; securing parts and cables; re-mate electrical connectors; closing of electrical panel; and reinstating thermal blanket. The current performance experiments are limited to thermal blanket cutting, electrical panel unbolting and handling electrical bundles and connectors. In one formal experiment even different control modes were applied to the unbolting and reinsertion of electrical panel screws subtasks. The seven control modes are alternative combinations of manual position and rate control with force feedback and remote compliance referenced to force-torque sensor information. Force-torque sensor and end effector position data and task completion times were recorded for analysis and quantification of operator performance.

  15. Numerical simulation and performance investigation of an advanced adsorption desalination cycle

    KAUST Repository

    Thu, Kyaw

    2013-01-01

    Low temperature waste heat-driven adsorption desalination (AD) cycles offer high potential as one of the most economically viable and environmental-friendly desalination methods. This article presents the development of an advanced adsorption desalination cycle that employs internal heat recovery between the evaporator and the condenser, utilizing an encapsulated evaporator-condenser unit for effective heat transfer. A simulation model has been developed based on the actual sorption characteristics of the adsorbent-adsorbate pair, energy and mass balances applied to the components of the AD cycle. With an integrated design, the temperature in the evaporator and the vapor pressurization of the adsorber are raised due to the direct heat recovery from the condenser, resulting in the higher water production rates, typically improved by as much as three folds of the conventional AD cycle. In addition, the integrated design eliminates two pumps, namely, the condenser cooling water and the chilled water pumps, lowering the overall electricity consumption. The performance of the cycle is analyzed at assorted heat source and cooling water temperatures, and different cycle times as well as the transient heat transfer coefficients of the evaporation and condensation. © 2012 Elsevier B.V.

  16. An expanded framework for the advanced computational testing and simulation toolkit

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Osni A.; Drummond, Leroy A.

    2003-11-09

    The Advanced Computational Testing and Simulation (ACTS) Toolkit is a set of computational tools developed primarily at DOE laboratories and is aimed at simplifying the solution of common and important computational problems. The use of the tools reduces the development time for new codes and the tools provide functionality that might not otherwise be available. This document outlines an agenda for expanding the scope of the ACTS Project based on lessons learned from current activities. Highlights of this agenda include peer-reviewed certification of new tools; finding tools to solve problems that are not currently addressed by the Toolkit; working in collaboration with other software initiatives and DOE computer facilities; expanding outreach efforts; promoting interoperability, further development of the tools; and improving functionality of the ACTS Information Center, among other tasks. The ultimate goal is to make the ACTS tools more widely used and more effective in solving DOE's and the nation's scientific problems through the creation of a reliable software infrastructure for scientific computing.

  17. Advisor 2.0: A Second-Generation Advanced Vehicle Simulator for Systems Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wipke, K.; Cuddy, M.; Bharathan, D.; Burch, S.; Johnson, V.; Markel, A.; Sprik, S.

    1999-03-23

    The National Renewable Energy Laboratory has recently publicly released its second-generation advanced vehicle simulator called ADVISOR 2.0. This software program was initially developed four years ago, and after several years of in-house usage and evolution, the tool is now available to the public through a new vehicle systems analysis World Wide Web page. ADVISOR has been applied to many different systems analysis problems, such as helping to develop the SAE J1711 test procedure for hybrid vehicles and helping to evaluate new technologies as part of the Partnership for a New Generation of Vehicles (PNGV) technology selection process. The model has been and will continue to be benchmarked and validated with other models and with real vehicle test data. After two months of being available on the Web, more than 100 users have downloaded ADVISOR. ADVISOR 2.0 has many new features, including an easy-to-use graphical user interface, a detailed exhaust aftertreatment thermal model, and complete browser-based documentation. Future work will include adding to the library of components available in ADVISOR, including optimization functionality, and linking with a more detailed fuel cell model.

  18. Coordinating Complementary Waveforms for Sidelobe Suppression

    CERN Document Server

    Dang, Wenbing; Howard, Stephen; Moran, William; Calderbank, Robert

    2012-01-01

    We present a general method for constructing radar transmit pulse trains and receive filters for which the radar point-spread function in delay and Doppler, given by the cross-ambiguity function of the transmit pulse train and the pulse train used in the receive filter, is essentially free of range sidelobes inside a Doppler interval around the zero-Doppler axis. The transmit pulse train is constructed by coordinating the transmission of a pair of Golay complementary waveforms across time according to zeros and ones in a binary sequence P. The pulse train used to filter the received signal is constructed in a similar way, in terms of sequencing the Golay waveforms, but each waveform in the pulse train is weighted by an element from another sequence Q. We show that a spectrum jointly determined by P and Q sequences controls the size of the range sidelobes of the cross-ambiguity function and by properly choosing P and Q we can clear out the range sidelobes inside a Doppler interval around the zero- Doppler axis...

  19. Satellite and Instrument Influences on ICESat Waveforms

    Science.gov (United States)

    Webb, C. E.; Urban, T. J.; Neuenschwander, A. L.; Gutierrez, R.; Schutz, B. E.

    2007-12-01

    The White Sands Space Harbor (WSSH) has served as the principal ground calibration site throughout the Ice, Cloud and land Elevation Satellite (ICESat) mission. The Center for Space Research (CSR) at the University of Texas at Austin continues to conduct various experiments designed to validate the timing, geolocation and geometric characteristics of individual laser footprints on the surface. In addition, two airborne lidar surveys of the calibration site and surrounding area were conducted during the mission, first in 2003 and again in 2007. Chosen for its limited surface roughness and topographic flatness, this area has been targeted 3-4 times in each of the 12 ICESat mapping campaigns to date, yielding a significant altimetry data set. The derived surface elevations are compared with those from the airborne lidar surveys, as well as those obtained by the Shuttle Radar Topography Mission (SRTM). Furthermore, the Geoscience Laser Altimetry System (GLAS) onboard ICESat records a digitized waveform for each laser pulse returned from the surface. The two methods currently used to fit such signals in ICESat data processing are examined and compared for the WSSH waveforms. The first fits up to two distinct Gaussians and provides a surface elevation at the location of the maximum peak. The second fits up to six overlapping Gaussians and provides a surface elevation at the centroid of the pulse. Observed differences in the reported elevations are discussed in terms of the satellite's off-nadir targeting geometry, the laser energy, and the skewness of the returned waveforms.

  20. Investigation of Alien Wavelength Quality in Live Multi-Domain, Multi-Vendor Link Using Advanced Simulation Tool

    DEFF Research Database (Denmark)

    Petersen, Martin Nordal; Nuijts, Roeland; Bjorn, Lars Lange

    2014-01-01

    This article presents an advanced optical model for simulation of alien wavelengths in multi-domain and multi-vendor dense wavelength-division multiplexing networks. The model aids optical network planners with a better understanding of the non-linear effects present in dense wavelength-division ......This article presents an advanced optical model for simulation of alien wavelengths in multi-domain and multi-vendor dense wavelength-division multiplexing networks. The model aids optical network planners with a better understanding of the non-linear effects present in dense wavelength......-division multiplexing systems and better utilization of alien wavelengths in future applications. The limiting physical effects for alien wavelengths are investigated in relation to power levels, channel spacing, and other factors. The simulation results are verified through experimental setup in live multi...

  1. Analysis of simulation tools for the study of advanced marine power systems

    OpenAIRE

    Brochard, Paul Eugene

    1992-01-01

    The United States Navy is at a crossroads in the design of ship's engineering plants. Advances in solid-state power electronics combined with a shift to gas turbine powered propulsion and electric plants has placed renewed emphasis on developing advanced power systems. These advanced power systems may combine the prime movers associated with propulsion and electric power generation into an integrated system. The development of advanced electric distribution systems and propulsion derived ship...

  2. The Waveform Server: A Web-based Interactive Seismic Waveform Interface

    Science.gov (United States)

    Newman, R. L.; Clemesha, A.; Lindquist, K. G.; Reyes, J.; Steidl, J. H.; Vernon, F. L.

    2009-12-01

    Seismic waveform data has traditionally been displayed on machines that are either local area networked to, or directly host, a seismic networks waveform database(s). Typical seismic data warehouses allow online users to query and download data collected from regional networks passively, without the scientist directly visually assessing data coverage and/or quality. Using a suite of web-based protocols, we have developed an online seismic waveform interface that directly queries and displays data from a relational database through a web-browser. Using the Python interface to Datascope and the Python-based Twisted network package on the server side, and the jQuery Javascript framework on the client side to send and receive asynchronous waveform queries, we display broadband seismic data using the HTML Canvas element that is globally accessible by anyone using a modern web-browser. The system is used to display data from the USArray experiment, a US continent-wide migratory transportable seismic array. We are currently creating additional interface tools to create a rich-client interface for accessing and displaying seismic data that can be deployed to any system running Boulder Real Time Technology's (BRTT) Antelope Real Time System (ARTS). The software is freely available from the Antelope contributed code Git repository. Screenshot of the web-based waveform server interface

  3. Advanced Unsteady Turbulent Combustion Simulation Capability for Space Propulsion Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation proposed here is a high performance, high fidelity simulation capability to enable accurate, fast and robust simulation of unsteady turbulent,...

  4. Update on ORNL TRANSFORM Tool: Simulating Multi-Module Advanced Reactor with End-to-End I&C

    Energy Technology Data Exchange (ETDEWEB)

    Hale, Richard Edward [ORNL; Fugate, David L [ORNL; Cetiner, Sacit M [ORNL; Qualls, A L [ORNL

    2015-05-01

    The Small Modular Reactor (SMR) Dynamic System Modeling Tool project is in the fourth year of development. The project is designed to support collaborative modeling and study of various advanced SMR (non-light water cooled reactor) concepts, including the use of multiple coupled reactors at a single site. The focus of this report is the development of a steam generator and drum system model that includes the complex dynamics of typical steam drum systems, the development of instrumentation and controls for the steam generator with drum system model, and the development of multi-reactor module models that reflect the full power reactor innovative small module design concept. The objective of the project is to provide a common simulation environment and baseline modeling resources to facilitate rapid development of dynamic advanced reactor models; ensure consistency among research products within the Instrumentation, Controls, and Human-Machine Interface technical area; and leverage cross-cutting capabilities while minimizing duplication of effort. The combined simulation environment and suite of models are identified as the TRANSFORM tool. The critical elements of this effort include (1) defining a standardized, common simulation environment that can be applied throughout the Advanced Reactors Technology program; (2) developing a library of baseline component modules that can be assembled into full plant models using available geometry, design, and thermal-hydraulic data; (3) defining modeling conventions for interconnecting component models; and (4) establishing user interfaces and support tools to facilitate simulation development (i.e., configuration and parameterization), execution, and results display and capture.

  5. Advanced Approach to Consider Aleatory and Epistemic Uncertainties for Integral Accident Simulations

    International Nuclear Information System (INIS)

    The use of best-estimate codes together with realistic input data generally requires that all potentially important epistemic uncertainties which may affect the code prediction are considered in order to get an adequate quantification of the epistemic uncertainty of the prediction as an expression of the existing imprecise knowledge. To facilitate the performance of the required epistemic uncertainty analyses, methods and corresponding software tools are available like, for instance, the GRS-tool SUSA (Software for Uncertainty and Sensitivity Analysis). However, for risk-informed decision-making, the restriction on epistemic uncertainties alone is not enough. Transients and accident scenarios are also affected by aleatory uncertainties which are due to the unpredictable nature of phenomena. It is essential that aleatory uncertainties are taken into account as well, not only in a simplified and supposedly conservative way but as realistic as possible. The additional consideration of aleatory uncertainties, for instance, on the behavior of the technical system, the performance of plant operators, or on the behavior of the physical process provides a quantification of probabilistically significant accident sequences. Only if a safety analysis is able to account for both epistemic and aleatory uncertainties in a realistic manner, it can provide a well-founded risk-informed answer for decision-making. At GRS, an advanced probabilistic dynamics method was developed to address this problem and to provide a more realistic modeling and assessment of transients and accident scenarios. This method allows for an integral simulation of complex dynamic processes particularly taking into account interactions between the plant dynamics as simulated by a best-estimate code, the dynamics of operator actions and the influence of epistemic and aleatory uncertainties. In this paper, the GRS method MCDET (Monte Carlo Dynamic Event Tree) for probabilistic dynamics analysis is explained

  6. Deriving pseudo-vertical waveforms from small-footprint full-waveform LiDAR data

    OpenAIRE

    Hermosilla, T.; Coops, Nicholas; Ruiz Fernández, Luis Ángel; Moskal, Monika

    2014-01-01

    This is an author's accepted manuscript of an article published in “Remote Sensing Letters", Volume 5, Issue 4, 2014; copyright Taylor & Francis; available online at: http://www.tandfonline.com/doi/abs/10.1080/2150704X.2014.903350 When processing scanning LiDAR data, it is commonly assumed that the extracted full-waveform LiDAR pulse registers truly vertical information of forest canopies. This assumption may lead to uncertain results for the spatiotemporal analysis of the waveforms due to...

  7. WRF4G project: Advances in running climate simulations on the EGI Infrastructure

    Science.gov (United States)

    Blanco, Carlos; Cofino, Antonio S.; Fernández Quiruelas, Valvanuz; García, Markel; Fernández, Jesús

    2014-05-01

    The Weather Research and Forecasting For Grid (WRF4G) project is a two-year Spanish National R&D project, which has started in 2011. It is now a well established project, involving scientists and technical staff from several institutions, which contribute results to international initiatives such as CORDEX and European FP7 projects such as SPECS and EUPORIAS. The aim of the WRF4G project is to homogenize access hybrid Distributed Computer Infrastructures (DCIs), such as HPC and Grid infrastructures, for climate researchers. Additionally, it provides a productive interface to accomplish ambitious climate experiments such as regional hind-cast/forecast and sensitivity studies. Although Grid infrastructures are very powerful, they have some drawbacks for executing climate applications such as the WRF model. This makes necessary to encapsulate the applications in a middleware in order to provide the appropriate services for monitoring and management. Therefore, the challenge of the WRF4G project is to develop a generic adaptation framework (WRF4G framework) to disseminate it to the scientific community. The framework aims at simplifying the model access by releasing climate scientists from technical and computational aspects. In this contribution, we present some new advances of the WRF4G framework, including new components for designing experiments, simulation monitoring and data management. Additionally, we will show how WRF4G makes possible to run complex experiments on EGI infrastructures concurrently over several VOs such as esr and earth.vo.ibergrid. http://www.meteo.unican.es/software/wrf4g This work has been partially funded by the European Regional Development Fund (ERDF) and the Spanish National R&D Plan 2008-2011 (CGL2011-28864, WRF4G)

  8. Noble gas and hydrocarbon tracers in multiphase unconventional hydrocarbon systems: Toward integrated advanced reservoir simulators

    Science.gov (United States)

    Darrah, T.; Moortgat, J.; Poreda, R. J.; Muehlenbachs, K.; Whyte, C. J.

    2015-12-01

    Although hydrocarbon production from unconventional energy resources has increased dramatically in the last decade, total unconventional oil and gas recovery from black shales is still less than 25% and 9% of the totals in place, respectively. Further, the majority of increased hydrocarbon production results from increasing the lengths of laterals, the number of hydraulic fracturing stages, and the volume of consumptive water usage. These strategies all reduce the economic efficiency of hydrocarbon extraction. The poor recovery statistics result from an insufficient understanding of some of the key physical processes in complex, organic-rich, low porosity formations (e.g., phase behavior, fluid-rock interactions, and flow mechanisms at nano-scale confinement and the role of natural fractures and faults as conduits for flow). Noble gases and other hydrocarbon tracers are capably of recording subsurface fluid-rock interactions on a variety of geological scales (micro-, meso-, to macro-scale) and provide analogs for the movement of hydrocarbons in the subsurface. As such geochemical data enrich the input for the numerical modeling of multi-phase (e.g., oil, gas, and brine) fluid flow in highly heterogeneous, low permeability formations Herein we will present a combination of noble gas (He, Ne, Ar, Kr, and Xe abundances and isotope ratios) and molecular and isotopic hydrocarbon data from a geographically and geologically diverse set of unconventional hydrocarbon reservoirs in North America. Specifically, we will include data from the Marcellus, Utica, Barnett, Eagle Ford, formations and the Illinois basin. Our presentation will include geochemical and geological interpretation and our perspective on the first steps toward building an advanced reservoir simulator for tracer transport in multicomponent multiphase compositional flow (presented separately, in Moortgat et al., 2015).

  9. Global inversion for anisotropy during full-waveform inversion

    Science.gov (United States)

    Debens, H. A.; Warner, M.; Umpleby, A.

    2015-12-01

    Full-waveform inversion (FWI) is a powerful tool for quantitative estimation of high-resolution high-fidelity models of subsurface seismic parameters, typically P-wave velocity. The solution to FWI's posed nonlinear inverse problem is obtained via an iterative series of linearized local updates to a start model, assuming this model lies within the basin of attraction to the global minimum. Thanks to many successful published applications to three-dimensional (3D) field datasets, its advance has been rapid and driven in large-part by the oil and gas industry. The consideration of seismic anisotropy during FWI is of vital importance, as it holds influence over both the kinematics and dynamics of seismic waveforms. If not appropriately taken into account then inadequacies in the anisotropy model are likely to manifest as significant error in the recovered velocity model. Conventionally, anisotropic FWI employs either an a priori anisotropy model, held fixed during FWI, or it uses a multi-parameter local inversion scheme to recover the anisotropy as part of the FWI; both of these methods can be problematic. Constructing an anisotropy model prior to FWI often involves intensive (and hence expensive) iterative procedures, such as travel-time tomography or moveout velocity analysis. On the other hand, introducing multiple parameters to FWI itself increases the complexity of what is already an underdetermined inverse problem. We propose that global rather than local FWI can be used to recover the long-wavelength acoustic anisotropy model, and that this can then be followed by more-conventional local FWI to recover the detailed model. We validate this approach using a full 3D field dataset, demonstrating that it avoids problems associated to crosstalk that can bedevil local inversion schemes, and reconciles well with in situ borehole measurements. Although our approach includes a global inversion for anisotropy, it is nonetheless affordable and practical for 3D field data.

  10. Best waveform score for diagnosing keratoconus

    Directory of Open Access Journals (Sweden)

    Allan Luz

    2013-12-01

    Full Text Available PURPOSE: To test whether corneal hysteresis (CH and corneal resistance factor (CRF can discriminate between keratoconus and normal eyes and to evaluate whether the averages of two consecutive measurements perform differently from the one with the best waveform score (WS for diagnosing keratoconus. METHODS: ORA measurements for one eye per individual were selected randomly from 53 normal patients and from 27 patients with keratoconus. Two groups were considered the average (CH-Avg, CRF-Avg and best waveform score (CH-WS, CRF-WS groups. The Mann-Whitney U-test was used to evaluate whether the variables had similar distributions in the Normal and Keratoconus groups. Receiver operating characteristics (ROC curves were calculated for each parameter to assess the efficacy for diagnosing keratoconus and the same obtained for each variable were compared pairwise using the Hanley-McNeil test. RESULTS: The CH-Avg, CRF-Avg, CH-WS and CRF-WS differed significantly between the normal and keratoconus groups (p<0.001. The areas under the ROC curve (AUROC for CH-Avg, CRF-Avg, CH-WS, and CRF-WS were 0.824, 0.873, 0.891, and 0.931, respectively. CH-WS and CRF-WS had significantly better AUROCs than CH-Avg and CRF-Avg, respectively (p=0.001 and 0.002. CONCLUSION: The analysis of the biomechanical properties of the cornea through the ORA method has proved to be an important aid in the diagnosis of keratoconus, regardless of the method used. The best waveform score (WS measurements were superior to the average of consecutive ORA measurements for diagnosing keratoconus.

  11. Insights Into GLAS Waveforms Using Google Earth

    Science.gov (United States)

    Fowler, D.; Khalsa, S. S.; Swick, R.; Haran, T.; Scambos, T.; Korn, D.

    2008-12-01

    The Geoscience Laser Altimeter System (GLAS) instrument aboard the Ice, Cloud, and land Elevation (ICESat) satellite was launched on 12 January 2003. The primary objective of the ICESat mission is to provide global measurements of polar ice sheet elevation to discern changes in ice volume and ice sheet mass balance over time. Secondary objectives of the mission are to measure sea ice thickness, cloud and atmospheric properties, land topography, vegetation canopy heights, ocean surface topography, and surface reflectivity. The GLAS instrument has three lasers, each of which has a 1064 nm laser channel for surface altimetry and dense cloud heights, and a 532 nm lidar channel for the vertical distribution of clouds and aerosols. The laser emits a pulse every 0.02 seconds, and receives a return signal. Laser footprints are roughly 70 meters in diameter and spaced 170 meters apart and are assigned terrestrial positions at the 10s of meters level of accuracy. As an aid to data selection we demonstrate how GLAS footprints, waveforms and quality information can be displayed in Google Earth. We represent the approximate spatial coverage of each laser shot on the Earth's surface, allowing users to assess the shot in the context of the surface characteristics gleaned from the underlying image and topography in Google Earth. Each footprint can be expanded to show the associated waveform, summarizing the detected return signal, along with numerical values for latitude and longitude, elevation, and date/time. Surface characteristics such as tree canopy, low- level dust or clouds, snow or ice cover, extreme surface roughness, have significant, easily-visible effects on the waveform. This application will provide extremely useful information, and will facilitate a detailed data preview before ordering or processing.

  12. Development of Advanced Wear and Corrosion Resistant Systems Through Laser Surface Alloying and Materials Simulations

    Energy Technology Data Exchange (ETDEWEB)

    R. P. Martukanitz and S. Babu

    2007-05-03

    Laser surfacing in the form of cladding, alloying, and modifications are gaining widespread use because of its ability to provide high deposition rates, low thermal distortion, and refined microstructure due to high solidification rates. Because of these advantages, laser surface alloying is considered a prime candidate for producing ultra-hard coatings through the establishment or in situ formation of composite structures. Therefore, a program was conducted by the Applied Research Laboratory, Pennsylvania State University and Oak Ridge National Laboratory to develop the scientific and engineering basis for performing laser-based surface modifications involving the addition of hard particles, such as carbides, borides, and nitrides, within a metallic matrix for improved wear, fatigue, creep, and corrosion resistance. This has involved the development of advanced laser processing and simulation techniques, along with the refinement and application of these techniques for predicting and selecting materials and processing parameters for the creation of new surfaces having improved properties over current coating technologies. This program has also resulted in the formulation of process and material simulation tools capable of examining the potential for the formation and retention of composite coatings and deposits produced using laser processing techniques, as well as positive laboratory demonstrations in producing these coatings. In conjunction with the process simulation techniques, the application of computational thermodynamic and kinetic models to design laser surface alloying materials was demonstrated and resulted in a vast improvement in the formulation of materials used for producing composite coatings. The methodology was used to identify materials and to selectively modify microstructures for increasing hardness of deposits produced by the laser surface alloying process. Computational thermodynamic calculations indicated that it was possible to induce the

  13. Development of Advanced Electrochemical Emission Spectroscopy for Monitoring Corrosion in Simulated DOE Liquid Waste

    Energy Technology Data Exchange (ETDEWEB)

    Digby Macdonald; Brian Marx; Balaji Soundararajan; Morgan Smith

    2005-07-28

    The different tasks that have been carried out under the current program are as follows: (1) Theoretical and experimental assessment of general corrosion of iron/steel in borate buffer solutions by using electrochemical impedance spectroscopy (EIS), ellipsometry and XPS techniques; (2) Development of a damage function analysis (DFA), which would help in predicting the accumulation of damage due to pitting corrosion in an environment prototypical of DOE liquid waste systems; (3) Experimental measurement of crack growth rate, acoustic emission signals, and coupling currents for fracture in carbon and low alloy steels as functions of mechanical (stress intensity), chemical (conductivity), electrochemical (corrosion potential, ECP), and microstructural (grain size, precipitate size, etc) variables in a systematic manner, with particular attention being focused on the structure of the noise in the current and its correlation with the acoustic emissions; (4) Development of fracture mechanisms for carbon and low alloy steels that are consistent with the crack growth rate, coupling current data and acoustic emissions; (5) Inserting advanced crack growth rate models for SCC into existing deterministic codes for predicting the evolution of corrosion damage in DOE liquid waste storage tanks; (6) Computer simulation of the anodic and cathodic activity on the surface of the steel samples in order to exactly predict the corrosion mechanisms; (7) Wavelet analysis of EC noise data from steel samples undergoing corrosion in an environment similar to that of the high level waste storage containers, to extract data pertaining to general, pitting and stress corrosion processes, from the overall data. The work has yielded a number of important findings, including an unequivocal demonstration of the role of chloride ion in passivity breakdown on nickel in terms of cation vacancy generation within the passive film, the first detection and characterization of individual micro fracture

  14. Nuclear energy advance modeling and simulation program-Fuels integrated performance and safety code program - A multi-scale approach to modeling and simulations

    International Nuclear Information System (INIS)

    The increased use of nuclear energy in the nations energy portfolio has been suggested recently by various social, economical and political organizations. Several options for the extension of nuclear energy being considered are; 1- Life Extension of Current Nuclear Reactors (operations at high burn ups), 2-Advanced New Generation Reactors (Gen III systems), 3- Generation IV Nuclear Energy Systems (particularly Next Generation Nuclear Plant (NGNP) concentrating on high temperature applications), and Advance Fuel Cycle Initiatives (AFCI) (fast reactor and advanced transmutation fuels). These new technology concepts will require new types of fuels (except the first option that may require more understanding of fuel behavior than development or minor modifications of fuels), and the new fuels have be developed and qualified. In the Nuclear Energy Advanced Modeling and Simulation (NEAMS) fuels Integrated Performance and Safety Code (IPSC) program we initially focus to the multi-scale modeling and simulation of new fuel types that AFCI Transmutation Fuel Campaign (TFC) program is developing. TFC is a natural customer of the NEMAS fuels IPSC project and a strong interaction and integration between the campaign and IPSC must be implemented. The program plan in terms of approach is general enough to be applicable to other fuel types of the future nuclear technology solutions. Requirements, however, may need to be updated for fuels not considered by TFC, depending upon the new physics findings. The advanced fuels of interest to AFCI programs are more complex than the traditional fuels previously and currently used in existing reactors. It is clear that using a traditional, heavily empirical approach to develop and qualify fuels over the entire range of variables pertinent to AFCI on a timely basis with available funds would be very challenging and costly, if not impossible. As a result, AFCI TFC has launched an advanced modeling and simulation campaign to revolutionize fuel

  15. Optimal Transport for Seismic Full Waveform Inversion

    CERN Document Server

    Engquist, Bjorn; Yang, Yunan

    2016-01-01

    Full waveform inversion is a successful procedure for determining properties of the earth from surface measurements in seismology. This inverse problem is solved by a PDE constrained optimization where unknown coefficients in a computed wavefield are adjusted to minimize the mismatch with the measured data. We propose using the Wasserstein metric, which is related to optimal transport, for measuring this mismatch. Several advantageous properties are proved with regards to convexity of the objective function and robustness with respect to noise. The Wasserstein metric is computed by solving a Monge-Ampere equation. We describe an algorithm for computing its Frechet gradient for use in the optimization. Numerical examples are given.

  16. CFD Simulations of a Regenerative Process for Carbon Dioxide Capture in Advanced Gasification Based Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Arastoopour, Hamid [Illinois Inst. of Technology, Chicago, IL (United States); Abbasian, Javad [Illinois Inst. of Technology, Chicago, IL (United States)

    2014-07-31

    This project describes the work carried out to prepare a highly reactive and mechanically strong MgO based sorbents and to develop a Population Balance Equations (PBE) approach to describe the evolution of the particle porosity distribution that is linked with Computational Fluid Dynamics (CFD) to perform simulations of the CO2 capture and sorbent regeneration. A large number of MgO-based regenerable sorbents were prepared using low cost and abundant dolomite as the base material. Among various preparation parameters investigated the potassium/magnesium (K/Mg) ratio was identified as the key variable affecting the reactivity and CO2 capacity of the sorbent. The optimum K/Mg ratio is about 0.15. The sorbent formulation HD52-P2 was identified as the “best” sorbent formulation and a large batch (one kg) of the sorbent was prepared for the detailed study. The results of parametric study indicate the optimum carbonation and regeneration temperatures are 360° and 500°C, respectively. The results also indicate that steam has a beneficial effect on the rate of carbonation and regeneration of the sorbent and that the reactivity and capacity of the sorbent decreases in the cycling process (sorbent deactivation). The results indicate that to achieve a high CO2 removal efficiency, the bed of sorbent should be operated at a temperature range of 370-410°C which also favors production of hydrogen through the WGS reaction. To describe the carbonation reaction kinetics of the MgO, the Variable Diffusivity shrinking core Model (VDM) was developed in this project, which was shown to accurately fit the experimental data. An important advantage of this model is that the changes in the sorbent conversion with time can be expressed in an explicit manner, which will significantly reduce the CFD computation time. A Computational Fluid Dynamic/Population Balance Equations (CFD/PBE) model was developed that accounts for the particle (sorbent) porosity distribution and a new version of

  17. Big data to smart data in Alzheimer's disease: Real-world examples of advanced modeling and simulation.

    Science.gov (United States)

    Haas, Magali; Stephenson, Diane; Romero, Klaus; Gordon, Mark Forrest; Zach, Neta; Geerts, Hugo

    2016-09-01

    Many disease-modifying clinical development programs in Alzheimer's disease (AD) have failed to date, and development of new and advanced preclinical models that generate actionable knowledge is desperately needed. This review reports on computer-based modeling and simulation approach as a powerful tool in AD research. Statistical data-analysis techniques can identify associations between certain data and phenotypes, such as diagnosis or disease progression. Other approaches integrate domain expertise in a formalized mathematical way to understand how specific components of pathology integrate into complex brain networks. Private-public partnerships focused on data sharing, causal inference and pathway-based analysis, crowdsourcing, and mechanism-based quantitative systems modeling represent successful real-world modeling examples with substantial impact on CNS diseases. Similar to other disease indications, successful real-world examples of advanced simulation can generate actionable support of drug discovery and development in AD, illustrating the value that can be generated for different stakeholders. PMID:27327540

  18. Large-scale simulations on thermal-hydraulics in fuel bundles of advanced nuclear reactors (Annual Report of the Earth Simulator Center, Dec 2008, 2007 issue)

    International Nuclear Information System (INIS)

    In order to predict the water-vapor two-phase flow dynamics in a fuel bundle of an advanced light-water reactor, large-scale numerical simulations were performed using a highly parallel-vector supercomputer, the earth simulator. Although conventional analysis methods such as subchannel codes and system analysis codes need composition equations based on the experimental data, it is difficult to obtain high prediction accuracy when experimental data to obtain the composition equations. Then, the present large-scale direct simulation method of water-vapor two-phase flow was proposed. The void fraction distribution in a fuel bundle under boiling heat transfer condition was analyzed and the bubble dynamics around the fuel rod surface were predicted quantitatively. (author)

  19. Recent advances on mesoscopic simulation of dislocation dynamics; Recientes avances en simulacion mesoscopica de la dinamica de dislocaciones

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Garcia, D.; Dominguez-Rodriguez, A.; Devincre, B.; Kubin, L. P.

    2001-07-01

    Recent advances in the description of dislocation dynamics are presented. Systems considered have realistic dislocation densities (i.e. densities close to those measured during the plastic deformation of single crystals {approx_equal}10''12 m''-2). The description is made through computer simulations in a bidimensional frame. Special emphasis will be made concerning the simplifications adopted, as well as the achievements. (Author) 3 refs.

  20. Complete phenomenological gravitational waveforms from spinning coalescing binaries

    CERN Document Server

    Sturani, R; Cadonati, L; Guidi, G M; Healy, J; Shoemaker, D; Viceré, A

    2010-01-01

    The quest for gravitational waves from coalescing binaries is customarily performed by the LIGO-Virgo collaboration via matched filtering, which requires a detailed knowledge of the signal. Complete analytical coalescence waveforms are currently available only for the non-precessing binary systems. In this paper we introduce complete phenomenological waveforms for the dominant quadrupolar mode of generically spinning systems. These waveforms are constructed by bridging the gap between the analytically known inspiral phase, described by spin Taylor (T4) approximants in the restricted waveform approximation, and the ring-down phase through a phenomenological intermediate phase, calibrated by comparison with specific, numerically generated waveforms, describing equal mass systems with dimension-less spin magnitudes equal to 0.6. The overlap integral between numerical and phenomenological waveforms ranges between 0.95 and 0.99.

  1. Complete phenomenological gravitational waveforms from spinning coalescing binaries

    Energy Technology Data Exchange (ETDEWEB)

    Sturani, R; Guidi, G M; Vicere, A [Dipartimento di Matematica, Fisica e Informatica, Universita degli Studi di Urbino ' Carlo Bo' , I-61029 Urbino (Italy); Fischetti, S; Cadonati, L [Physics Department, University of Massachusetts, Amherst, MA 01003 (United States); Healy, J; Shoemaker, D, E-mail: riccardo.sturani@uniurb.i [Center for Relativistic Astrophysics, Georgia Tech, Atlanta, GA 30332 (United States)

    2010-08-01

    The quest for gravitational waves from coalescing binaries is customarily performed by the LIGO-Virgo collaboration via matched filtering, which requires a detailed knowledge of the signal. Complete analytical coalescence waveforms are currently available only for the non-precessing binary systems. In this paper we introduce complete phenomenological waveforms for the dominant quadrupolar mode of generically spinning systems. These waveforms are constructed by bridging the gap between the analytically known inspiral phase, described by spin Taylor (T4) approximants in the restricted waveform approximation, and the ring-down phase through a phenomenological intermediate phase, calibrated by comparison with specific, numerically generated waveforms, describing equal mass systems with dimension-less spin magnitudes equal to 0.6. The overlap integral between numerical and phenomenological waveforms ranges between 0.95 and 0.99.

  2. Results from Binary Black Hole Simulations in Astrophysics Applications

    Science.gov (United States)

    Baker, John G.

    2007-01-01

    Present and planned gravitational wave observatories are opening a new astronomical window to the sky. A key source of gravitational waves is the merger of two black holes. The Laser Interferometer Space Antenna (LISA), in particular, is expected to observe these events with signal-to-noise ratio's in the thousands. To fully reap the scientific benefits of these observations requires a detailed understanding, based on numerical simulations, of the predictions of General Relativity for the waveform signals. New techniques for simulating binary black hole mergers, introduced two years ago, have led to dramatic advances in applied numerical simulation work. Over the last two years, numerical relativity researchers have made tremendous strides in understanding the late stages of binary black hole mergers. Simulations have been applied to test much of the basic physics of binary black hole interactions, showing robust results for merger waveform predictions, and illuminating such phenomena as spin-precession. Calculations have shown that merging systems can be kicked at up to 2500 km/s by the thrust from asymmetric emission. Recently, long lasting simulations of ten or more orbits allow tests of post-Newtonian (PN) approximation results for radiation from the last orbits of the binary's inspiral. Already, analytic waveform models based PN techniques with incorporated information from numerical simulations may be adequate for observations with current ground based observatories. As new advances in simulations continue to rapidly improve our theoretical understanding of the systems, it seems certain that high-precision predictions will be available in time for LISA and other advanced ground-based instruments. Future gravitational wave observatories are expected to make precision.

  3. Fetal electrocardiogram: ST waveform analysis in intrapartum surveillance

    OpenAIRE

    Amer-Wahlin, I; Arulkumaran, S; Hagberg, H.; Maršál, K; Visser, GHA

    2007-01-01

    ST waveform analysis of fetal electrocardiogram (ECG) for intrapartum surveillance (STAN) is a newly introduced method for fetal surveillance. The purpose of this commentary is to assist in the proper use of fetal ECG in combination with cardiotocography (CTG) during labour. Guidelines and recommendations concerning CTG and ST waveform interpretation and classification are stated that were agreed on by the European experts on ST waveform analysis for intrapartum surveillance during a meeting ...

  4. Direct Current Contamination of Kilohertz Frequency Alternating Current Waveforms

    OpenAIRE

    Franke, Manfred; Bhadra, Niloy; Bhadra, Narendra; Kilgore, Kevin

    2014-01-01

    Kilohertz Frequency Alternating Current (KHFAC) waveforms are being evaluated in a variety of physiological settings because of their potential to modulate neural activity uniquely when compared to frequencies in the sub-kilohertz range. However, the use of waveforms in this frequency range presents some unique challenges regarding the generator output. In this study we explored the possibility of undesirable contamination of the KHFAC waveforms by direct current (DC). We evaluated current- a...

  5. A high success rate full-waveform lidar echo decomposition method

    Science.gov (United States)

    Xu, Lijun; Li, Duan; Li, Xiaolu

    2016-01-01

    A full-waveform Light detection and ranging (LiDAR) echo decomposition method is proposed in this paper. In this method, the peak points are used to detect the separated echo components, while the inflection points are combined with corresponding peak points to detect the overlapping echo components. The detected echo components are then sorted according to their energies in a descending order. The sorted echo components are one by one added into the decomposition model according to their orders. For each addition, the parameters of all echo components already added into the decomposition model are iteratively renewed. After renewing, the amplitudes and full width at half maximums of the echo components are compared with pre-set thresholds to determine and remove the false echo components. Both simulation and experiment were carried out to evaluate the proposed method. In simulation, 4000 full-waveform echoes with different numbers and parameters of echo components were generated and decomposed using the proposed and three other commonly used methods. Results show that the proposed method is of the highest success rate, 91.43%. In experiment, 9549 Geoscience Laser Altimeter System (GLAS) echoes for Shennongjia forest district in south China were employed as test echoes. The test echoes were first decomposed using the four methods and the decomposition results were also compared with those provided by the National Snow and Ice Data Center. Comparison results show that the determination coefficient ({{R}2} ) of the proposed method is of the largest mean, 0.6838, and the smallest standard deviation, 0.3588, and the distribution of the number of the echo components decomposed from the GLAS echoes is the most satisfied with the situation of full-waveform echoes from the forest area, implying that the superposition of the echo components decomposed from a full-waveform echo by using the proposed method can best approximate the full-waveform echo.

  6. Target discrimination technique utilizing noise waveforms

    Science.gov (United States)

    Woodington, Gordon; DeLuca, Mark; Moro, Richard; Lemus, Daniel; Vela, Russell; Narayanan, Ram

    2011-06-01

    Noise waveforms generated using low cost diodes are a simple way for radars to transmit a wideband (> 4 GHz) multi-bit pseudorandom code for use in a cross correlation receiver. This type of waveform also has the advantage of being difficult to intercept and is less prone to interfere with adjacent systems. Radar designed to operate over this wide frequency range can take advantage of unique target Radar Cross Section (RCS) ripple versus frequency for objects of different materials and sizes. Specifically the periodicity and amplitude of the ripple is dependent on the shape and size of a target. Since background clutter does not display this variation, RCS variation determines whether a known target is present in a return. This paper will present the radar hardware and signal processing techniques used to maximize a target's unique spectral response against a cluttered background. The system operates CW over a 4-8 GHz bandwidth requiring the need to address issues regarding range resolution and far out undesired returns. Lessons learned from field observations and mitigation techniques incorporated in the system are included. This paper also deals with the signal processing technique used for detection, then discrimination. Detection thresholds are set and triggered by a simple correlation peak level. Discrimination involves inspection of the spectral return. A comparison performed in real time to a stored library value determines the presence of known objects. Measured data provided demonstrates the ability of the radar to discriminate multiple targets against multiple backgrounds.

  7. Advancement of DOE's EnergyPlus Building Energy Simulation Payment

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Lixing [Florida Solar Energy Center, Cocoa, FL (United States); Shirey, Don [Florida Solar Energy Center, Cocoa, FL (United States); Raustad, Richard [Florida Solar Energy Center, Cocoa, FL (United States); Nigusse, Bereket [Florida Solar Energy Center, Cocoa, FL (United States); Sharma, Chandan [Florida Solar Energy Center, Cocoa, FL (United States); Lawrie, Linda [DHL Consulting, Bonn (Germany); Strand, Rick [Univ. of Illinois, Champaign, IL (United States); Pedersen, Curt [COPA, Panama City (Panama); Fisher, Dan [Oklahoma State Univ., Stillwater, OK (United States); Lee, Edwin [Oklahoma State Univ., Stillwater, OK (United States); Witte, Mike [GARD Analytics, Arlington Heights, IL (United States); Glazer, Jason [GARD Analytics, Arlington Heights, IL (United States); Barnaby, Chip [Wrightsoft, Lexington, MA (United States)

    2011-09-30

    EnergyPlus{sup TM} is a new generation computer software analysis tool that has been developed, tested, and commercialized to support DOE's Building Technologies (BT) Program in terms of whole-building, component, and systems R&D (http://www.energyplus.gov). It is also being used to support evaluation and decision making of zero energy building (ZEB) energy efficiency and supply technologies during new building design and existing building retrofits. The 5-year project was managed by the National Energy Technology Laboratory and was divided into 5 budget period between 2006 and 2011. During the project period, 11 versions of EnergyPlus were released. This report summarizes work performed by an EnergyPlus development team led by the University of Central Florida's Florida Solar Energy Center (UCF/FSEC). The team members consist of DHL Consulting, C. O. Pedersen Associates, University of Illinois at Urbana-Champaign, Oklahoma State University, GARD Analytics, Inc., and WrightSoft Corporation. The project tasks involved new feature development, testing and validation, user support and training, and general EnergyPlus support. The team developed 146 new features during the 5-year period to advance the EnergyPlus capabilities. Annual contributions of new features are 7 in budget period 1, 19 in period 2, 36 in period 3, 41 in period 4, and 43 in period 5, respectively. The testing and validation task focused on running test suite and publishing report, developing new IEA test suite cases, testing and validating new source code, addressing change requests, and creating and testing installation package. The user support and training task provided support for users and interface developers, and organized and taught workshops. The general support task involved upgrading StarTeam (team sharing) software and updating existing utility software. The project met the DOE objectives and completed all tasks successfully. Although the EnergyPlus software was enhanced

  8. Adaptive Robust Waveform Selection for Unknown Target Detection in Clutter

    Institute of Scientific and Technical Information of China (English)

    Lu-Lu Wang; Hong-Qiang Wang; Yu-Liang Qin; Yong-Qiang Cheng

    2014-01-01

    @@@A basic assumption of most recently proposed waveform design algorithms is that the target impulse response is a known deterministic function or a stochastic process with a known power spectral density (PSD). However, it is well-known that a target impulse response is neither easily nor accurately obtained; besides it changes sharply with attitude angles. Both of the aforementioned cases complicate the waveform design process. In this paper, an adaptive robust waveform selection method for unknown target detection in clutter is proposed. The target impulse response is considered to be unknown but belongs to a known uncertainty set. An adaptive waveform library is devised by using a signal-to-clutter-plus-noise ratio (SCNR)- based optimal waveform design method. By applying the minimax robust waveform selection method, the optimal robust waveform is selected to ensure the lowest performance bound of the unknown target detection in clutter. Results show that the adaptive waveform library outperforms the predefined linear frequency modulation (LFM) waveform library on the SCNR bound.

  9. Laplace-domain waveform modeling and inversion for the 3D acoustic-elastic coupled media

    Science.gov (United States)

    Shin, Jungkyun; Shin, Changsoo; Calandra, Henri

    2016-06-01

    Laplace-domain waveform inversion reconstructs long-wavelength subsurface models by using the zero-frequency component of damped seismic signals. Despite the computational advantages of Laplace-domain waveform inversion over conventional frequency-domain waveform inversion, an acoustic assumption and an iterative matrix solver have been used to invert 3D marine datasets to mitigate the intensive computing cost. In this study, we develop a Laplace-domain waveform modeling and inversion algorithm for 3D acoustic-elastic coupled media by using a parallel sparse direct solver library (MUltifrontal Massively Parallel Solver, MUMPS). We precisely simulate a real marine environment by coupling the 3D acoustic and elastic wave equations with the proper boundary condition at the fluid-solid interface. In addition, we can extract the elastic properties of the Earth below the sea bottom from the recorded acoustic pressure datasets. As a matrix solver, the parallel sparse direct solver is used to factorize the non-symmetric impedance matrix in a distributed memory architecture and rapidly solve the wave field for a number of shots by using the lower and upper matrix factors. Using both synthetic datasets and real datasets obtained by a 3D wide azimuth survey, the long-wavelength component of the P-wave and S-wave velocity models is reconstructed and the proposed modeling and inversion algorithm are verified. A cluster of 80 CPU cores is used for this study.

  10. Importance of covariance components of waveform data with high sampling rate in seismic source inversion

    Science.gov (United States)

    Yagi, Y.; Fukahata, Y.

    2007-12-01

    As computer technology advanced, it has become possible to observe seismic wave with a higher sampling rate and perform inversion for a larger data set. In general, to obtain a finer image of seismic source processes, waveform data with a higher sampling rate are needed. Then we encounter a problem whether there is no limitation of sampling rate in waveform inversion. In traditional seismic source inversion, covariance components of sampled waveform data have commonly been neglected. In fact, however, observed waveform data are not completely independent of each other at least in time domain, because they are always affected by un-elastic attenuation in the propagation of seismic waves through the Earth. In this study, we have developed a method of seismic source inversion to take the data covariance into account, and applied it to teleseismic P-wave data of the 2003 Boumerdes-Zemmouri, Algeria earthquake. From a comparison of final slip distributions inverted by the new formulation and the traditional formulation, we found that the effect of covariance components is crucial for a data set of higher sampling rates (≥ 5 Hz). For higher sampling rates, the slip distributions by the new formulation look stable, whereas the slip distributions by the traditional formulation tend to concentrate into small patches due to overestimation of the information from observed data. Our result indicates that the un-elastic effect of the Earth gives a limitation to the resolution of inverted seismic source models. It has been pointed out that seismic source models obtained from waveform data analyses are quite different from one another. One possible reason for the discrepancy is the neglect of covariance components. The new formulation must be useful to obtain a standard seismic source model.

  11. Waveform Similarity Analysis: A Simple Template Comparing Approach for Detecting and Quantifying Noisy Evoked Compound Action Potentials.

    Directory of Open Access Journals (Sweden)

    Jason Robert Potas

    Full Text Available Experimental electrophysiological assessment of evoked responses from regenerating nerves is challenging due to the typical complex response of events dispersed over various latencies and poor signal-to-noise ratio. Our objective was to automate the detection of compound action potential events and derive their latencies and magnitudes using a simple cross-correlation template comparison approach. For this, we developed an algorithm called Waveform Similarity Analysis. To test the algorithm, challenging signals were generated in vivo by stimulating sural and sciatic nerves, whilst recording evoked potentials at the sciatic nerve and tibialis anterior muscle, respectively, in animals recovering from sciatic nerve transection. Our template for the algorithm was generated based on responses evoked from the intact side. We also simulated noisy signals and examined the output of the Waveform Similarity Analysis algorithm with imperfect templates. Signals were detected and quantified using Waveform Similarity Analysis, which was compared to event detection, latency and magnitude measurements of the same signals performed by a trained observer, a process we called Trained Eye Analysis. The Waveform Similarity Analysis algorithm could successfully detect and quantify simple or complex responses from nerve and muscle compound action potentials of intact or regenerated nerves. Incorrectly specifying the template outperformed Trained Eye Analysis for predicting signal amplitude, but produced consistent latency errors for the simulated signals examined. Compared to the trained eye, Waveform Similarity Analysis is automatic, objective, does not rely on the observer to identify and/or measure peaks, and can detect small clustered events even when signal-to-noise ratio is poor. Waveform Similarity Analysis provides a simple, reliable and convenient approach to quantify latencies and magnitudes of complex waveforms and therefore serves as a useful tool for

  12. Electron power absorption dynamics in capacitive radio frequency discharges driven by tailored voltage waveforms in CF4

    Science.gov (United States)

    Brandt, S.; Berger, B.; Schüngel, E.; Korolov, I.; Derzsi, A.; Bruneau, B.; Johnson, E.; Lafleur, T.; O’Connell, D.; Koepke, M.; Gans, T.; Booth, J.-P.; Donkó, Z.; Schulze, J.

    2016-08-01

    The power absorption dynamics of electrons and the electrical asymmetry effect in capacitive radio-frequency plasmas operated in CF4 and driven by tailored voltage waveforms are investigated experimentally in combination with kinetic simulations. The driving voltage waveforms are generated as a superposition of multiple consecutive harmonics of the fundamental frequency of 13.56 MHz. Peaks/valleys and sawtooth waveforms are used to study the effects of amplitude and slope asymmetries of the driving voltage waveform on the electron dynamics and the generation of a DC self-bias in an electronegative plasma at different pressures. Compared to electropositive discharges, we observe strongly different effects and unique power absorption dynamics. At high pressures and high electronegativities, the discharge is found to operate in the drift-ambipolar (DA) heating mode. A dominant excitation/ionization maximum is observed during sheath collapse at the edge of the sheath which collapses fastest. High negative-ion densities are observed inside this sheath region, while electrons are confined for part of the RF period in a potential well formed by the ambipolar electric field at this sheath edge and the collapsed (floating potential) sheath at the electrode. For specific driving voltage waveforms, the plasma becomes divided spatially into two different halves of strongly different electronegativity. This asymmetry can be reversed electrically by inverting the driving waveform. For sawtooth waveforms, the discharge asymmetry and the sign of the DC self-bias are found to reverse as the pressure is increased, due to a transition of the electron heating mode from the α-mode to the DA-mode. These effects are interpreted with the aid of the simulation results.

  13. Understanding the impact of recent advances in isoprene photooxidation on simulations of regional air quality

    OpenAIRE

    Xie, Y.; F. Paulot; W. P. L. Carter; C. G. Nolte; Luecken, D. J.; W. T. Hutzell; Wennberg, P. O.; Cohen, R. C.; Pinder, R. W.

    2013-01-01

    The CMAQ (Community Multiscale Air Quality) us model in combination with observations for INTEX-NA/ICARTT (Intercontinental Chemical Transport Experiment–North America/International Consortium for Atmospheric Research on Transport and Transformation) 2004 are used to evaluate recent advances in isoprene oxidation chemistry and provide constraints on isoprene nitrate yields, isoprene nitrate lifetimes, and NOx recycling rates. We incorporate recent advances in isoprene oxidation chemistry into...

  14. Understanding the impact of recent advances in isoprene photooxidation on simulations of regional air quality

    OpenAIRE

    Xie, Y.; W. P. L. Carter; C. G. Nolte; Luecken, D. J.; W. T. Hutzell; Wennberg, P. O.; Cohen, R. C.; Pinder, R. W.

    2013-01-01

    The CMAQ (Community Multiscale Air Quality) us model in combination with observations for INTEX-NA/ICARTT (Intercontinental Chemical Transport Experiment–North America/International Consortium for Atmospheric Research on Transport and Transformation) 2004 are used to evaluate recent advances in isoprene oxidation chemistry and provide constraints on isoprene nitrate yields, isoprene nitrate lifetimes, and NO_x recycling rates. We incorporate recent advances in isoprene oxidation chemistry int...

  15. Exploring the use of numerical relativity waveforms in burst analysis of precessing black hole mergers

    International Nuclear Information System (INIS)

    Recent years have witnessed tremendous progress in numerical relativity and an ever improving performance of ground-based interferometric gravitational wave detectors. In preparation for the Advanced Laser Interferometer Gravitational Wave Observatory (Advanced LIGO) and a new era in gravitational wave astronomy, the numerical relativity and gravitational wave data analysis communities are collaborating to ascertain the most useful role for numerical relativity waveforms in the detection and characterization of binary black hole coalescences. In this paper, we explore the detectability of equal mass, merging black hole binaries with precessing spins and total mass MT(set-membership sign)[80,350]M·, using numerical relativity waveforms and templateless search algorithms designed for gravitational wave bursts. In particular, we present a systematic study using waveforms produced by the MayaKranc code that are added to colored, Gaussian noise and analyzed with the Omega burst search algorithm. Detection efficiency is weighed against the orientation of one of the black-hole's spin axes. We find a strong correlation between the detection efficiency and the radiated energy and angular momentum, and that the inclusion of the l=2, m=±1, 0 modes, at a minimum, is necessary to account for the full dynamics of precessing systems.

  16. Advances in HYDRA and its applications to simulations of inertial confinement fusion targets

    OpenAIRE

    Marinak M.M.; Kerbel G.D.; Koning J.M.; Patel M.V.; Sepke S.M.; McKinley M.S.; O'Brien M.J.; Procassini R.J.; Munro D.

    2013-01-01

    A new set of capabilities has been implemented in the HYDRA 2D/3D multiphysics inertial confinement fusion simulation code. These include a Monte Carlo particle transport library. It models transport of neutrons, gamma rays and light ions, as well as products they generate from nuclear and coulomb collisions. It allows accurate simulations of nuclear diagnostic signatures from capsule implosions. We apply it to here in a 3D simulation of a National Ignition Facility (NIF) ignition capsule whi...

  17. Development of Advanced Electrochemical Emission Spectroscopy for Monitoring Corrosion in Simulated DOE Liquid Waste

    Energy Technology Data Exchange (ETDEWEB)

    Digby D. Macdonald; Brian M. Marx; Sejin Ahn; Julio de Ruiz; Balaji Soundararaja; Morgan Smith; and Wendy Coulson

    2008-01-15

    Various forms of general and localized corrosion represent principal threats to the integrity of DOE liquid waste storage tanks. These tanks, which are of a single wall or double wall design, depending upon their age, are fabricated from welded carbon steel and contain a complex waste-form comprised of NaOH and NaNO{sub 3}, along with trace amounts of phosphate, sulfate, carbonate, and chloride. Because waste leakage can have a profound environmental impact, considerable interest exists in predicting the accumulation of corrosion damage, so as to more effectively schedule maintenance and repair. The different tasks that are being carried out under the current program are as follows: (1) Theoretical and experimental assessment of general corrosion of iron/steel in borate buffer solutions by using electrochemical impedance spectroscopy (EIS), ellipsometry and XPS techniques; (2) Development of a damage function analysis (DFA) which would help in predicting the accumulation of damage due to pitting corrosion in an environment prototypical of DOE liquid waste systems; (3) Experimental measurement of crack growth rate, acoustic emission signals and coupling currents for fracture in carbon and low alloy steels as functions of mechanical (stress intensity), chemical (conductivity), electrochemical (corrosion potential, ECP), and microstructural (grain size, precipitate size, etc) variables in a systematic manner, with particular attention being focused on the structure of the noise in the current and its correlation with the acoustic emissions; (4) Development of fracture mechanisms for carbon and low alloy steels that are consistent with the crack growth rate, coupling current data and acoustic emissions; (5) Inserting advanced crack growth rate models for SCC into existing deterministic codes for predicting the evolution of corrosion damage in DOE liquid waste storage tanks; (6) Computer simulation of the anodic and cathodic activity on the surface of the steel samples

  18. Accurately fitting advanced training. Flexible simulator training by modular training course concepts

    International Nuclear Information System (INIS)

    Every employee of a power plant contributes with his individual expertise to the success of the enterprise. Certainly personal skills of employees differ from each other as well as power plants are different. With respect to effective simulator training this means that no two simulator training courses can be identical. To exactly meet the requirements of our customers KWS has developed modules for simulation training courses. Each module represents either a technical subject or addresses a topic in the field of soft skills. An accurately fitting combination of several of these modules to the needs of our customers allows for most efficient simulator training courses. (orig.)

  19. Advances in HYDRA and its applications to simulations of inertial confinement fusion targets

    Directory of Open Access Journals (Sweden)

    Marinak M.M.

    2013-11-01

    Full Text Available A new set of capabilities has been implemented in the HYDRA 2D/3D multiphysics inertial confinement fusion simulation code. These include a Monte Carlo particle transport library. It models transport of neutrons, gamma rays and light ions, as well as products they generate from nuclear and coulomb collisions. It allows accurate simulations of nuclear diagnostic signatures from capsule implosions. We apply it to here in a 3D simulation of a National Ignition Facility (NIF ignition capsule which models the full capsule solid angle. This simulation contains a severely rough ablator perturbation and provides diagnostics signatures of capsule failure due to excessive instability growth.

  20. Advances in HYDRA and its applications to simulations of inertial confinement fusion targets

    International Nuclear Information System (INIS)

    A new set of capabilities has been implemented in the HYDRA 2D/3D multiphysics inertial confinement fusion simulation code. These include a Monte Carlo particle transport library. It models transport of neutrons, gamma rays and light ions, as well as products they generate from nuclear and coulomb collisions. It allows accurate simulations of nuclear diagnostic signatures from capsule implosions. We apply it to here in a 3D simulation of a National Ignition Facility (NIF) ignition capsule which models the full capsule solid angle. This simulation contains a severely rough ablator perturbation and provides diagnostics signatures of capsule failure due to excessive instability growth. (authors)

  1. Waveform Selectivity at the Same Frequency

    CERN Document Server

    Wakatsuchi, Hiroki; Rushton, Jeremiah J; Gao, Fei; Kim, Sanghoon; Sievenpiper, Daniel F

    2014-01-01

    Electromagnetic properties depend on the composition of materials, i.e. either angstrom scales of molecules or, for metamaterials, subwavelength periodic structures. Each material behaves differently in accordance with the frequency of an incoming electromagnetic wave due to the frequency dispersion or the resonance of the periodic structures. This indicates that if the frequency is fixed, the material always responds in the same manner unless it has nonlinearity. However, such nonlinearity is controlled by the magnitude of the incoming wave or other bias. Therefore, it is difficult to distinguish different incoming waves at the same frequency. Here we present a new concept of circuit-based metasurfaces to selectively absorb or transmit specific types of waveforms even at the same frequency. The metasurfaces, integrated with schottky diodes as well as either capacitors or inductors, selectively absorb short or long pulses, respectively. The two types of the circuit elements are then combined to absorb or tran...

  2. Flagellar waveform analysis of swimming algal cells

    Science.gov (United States)

    Kurtuldu, Huseyin; Johnson, Karl; Gollub, Jerry

    2011-11-01

    The twin flagella of the green alga Chlamydomas reinhardtii are driven by dynein molecular motors to oscillate at about 50-60 Hz in a breaststroke motion. For decades, Chlamydomas has been used as a model organism for studies of flagellar motility, and of genetic disorders of ciliary motion. However, little is known experimentally about the flagellar waveforms, and the resulting time-dependent force distribution along the 250 nm diameter flagella. Here, we study flagellar dynamics experimentally by confining cells in quasi-2D liquid films. From simultaneous measurements of the cell body velocity and the time-dependent velocities along the center lines of the two flagella, we determine the drag coefficients, and estimate the power expended by the body and the flagella, comparing our findings with measurements based on the induced fluid flow field. We contrast the results for the quite different beating patterns of synchronous and asynchronous flagella, respectively. Supported by NSF Grant DMR-0803153.

  3. Advanced Techniques for Reservoir Simulation and Modeling of Non-Conventional Wells; FINAL

    International Nuclear Information System (INIS)

    Research results for the second year of this project on the development of improved modeling techniques for non-conventional (e.g., horizontal, deviated or multilateral) wells were presented. The overall program entails the development of enhanced well modeling and general simulation capabilities. A general formulation for black-oil and compositional reservoir simulation was presented

  4. Advanced Techniques for Reservoir Simulation and Modeling of Non-Conventional Wells

    Energy Technology Data Exchange (ETDEWEB)

    Durlofsky, Louis J.; Aziz, Khalid

    2001-08-23

    Research results for the second year of this project on the development of improved modeling techniques for non-conventional (e.g., horizontal, deviated or multilateral) wells were presented. The overall program entails the development of enhanced well modeling and general simulation capabilities. A general formulation for black-oil and compositional reservoir simulation was presented.

  5. Automated multimode inversion of surface and S waveforms

    NARCIS (Netherlands)

    Lebedev, Sergei; Nolet, Guust; Meier, Thomas; Hilst, R.D. van der

    2005-01-01

    Inversion of the surface, S, and multiple-S waveforms is an effective means of constraining the structure of the upper mantle, including the transition zone. Exploiting the resolving power of the enormous volume of presently available data requires efficiency of data processing and waveform modellin

  6. Flagellar waveform dynamics of freely swimming algal cells

    NARCIS (Netherlands)

    Kurtuldu, H.; Tam, D.; Hosoi, A.E.; Johnson, K.A.; Gollub, J.P.

    2013-01-01

    We present quantitative measurements of time-dependent flagellar waveforms for freely swimming biflagellated algal cells, for both synchronous and asynchronous beating. We use the waveforms in conjunction with resistive force theory as well as a singularity method to predict a cell's time-dependent

  7. Assessing waveform predictions of recent three-dimensional velocity models of the Tibetan Plateau

    Science.gov (United States)

    Bao, Xueyang; Shen, Yang

    2016-04-01

    Accurate velocity models are essential for both the determination of earthquake locations and source moments and the interpretation of Earth structures. With the increasing number of three-dimensional velocity models, it has become necessary to assess the models for accuracy in predicting seismic observations. Six models of the crustal and uppermost mantle structures in Tibet and surrounding regions are investigated in this study. Regional Rayleigh and Pn (or Pnl) waveforms from two ground truth events, including one nuclear explosion and one natural earthquake located in the study area, are simulated by using a three-dimensional finite-difference method. Synthetics are compared to observed waveforms in multiple period bands of 20-75 s for Rayleigh waves and 1-20 s for Pn/Pnl waves. The models are evaluated based on the phase delays and cross-correlation coefficients between synthetic and observed waveforms. A model generated from full-wave ambient noise tomography best predicts Rayleigh waves throughout the data set, as well as Pn/Pnl waves traveling from the Tarim Basin to the stations located in central Tibet. In general, the models constructed from P wave tomography are not well suited to predict Rayleigh waves, and vice versa. Possible causes of the differences between observed and synthetic waveforms, and frequency-dependent variations of the "best matching" models with the smallest prediction errors are discussed. This study suggests that simultaneous prediction for body and surface waves requires an integrated velocity model constructed with multiple seismic waveforms and consideration of other important properties, such as anisotropy.

  8. Brain-wave measures of workload in advanced cockpits: The transition of technology from laboratory to cockpit simulator, phase 2

    Science.gov (United States)

    Horst, Richard L.; Mahaffey, David L.; Munson, Robert C.

    1989-01-01

    The present Phase 2 small business innovation research study was designed to address issues related to scalp-recorded event-related potential (ERP) indices of mental workload and to transition this technology from the laboratory to cockpit simulator environments for use as a systems engineering tool. The project involved five main tasks: (1) Two laboratory studies confirmed the generality of the ERP indices of workload obtained in the Phase 1 study and revealed two additional ERP components related to workload. (2) A task analysis' of flight scenarios and pilot tasks in the Advanced Concepts Flight Simulator (ACFS) defined cockpit events (i.e., displays, messages, alarms) that would be expected to elicit ERPs related to workload. (3) Software was developed to support ERP data analysis. An existing ARD-proprietary package of ERP data analysis routines was upgraded, new graphics routines were developed to enhance interactive data analysis, and routines were developed to compare alternative single-trial analysis techniques using simulated ERP data. (4) Working in conjunction with NASA Langley research scientists and simulator engineers, preparations were made for an ACFS validation study of ERP measures of workload. (5) A design specification was developed for a general purpose, computerized, workload assessment system that can function in simulators such as the ACFS.

  9. A Visual Basic simulation software tool for performance analysis of a membrane-based advanced water treatment plant.

    Science.gov (United States)

    Pal, P; Kumar, R; Srivastava, N; Chowdhury, J

    2014-02-01

    A Visual Basic simulation software (WATTPPA) has been developed to analyse the performance of an advanced wastewater treatment plant. This user-friendly and menu-driven software is based on the dynamic mathematical model for an industrial wastewater treatment scheme that integrates chemical, biological and membrane-based unit operations. The software-predicted results corroborate very well with the experimental findings as indicated in the overall correlation coefficient of the order of 0.99. The software permits pre-analysis and manipulation of input data, helps in optimization and exhibits performance of an integrated plant visually on a graphical platform. It allows quick performance analysis of the whole system as well as the individual units. The software first of its kind in its domain and in the well-known Microsoft Excel environment is likely to be very useful in successful design, optimization and operation of an advanced hybrid treatment plant for hazardous wastewater. PMID:23982824

  10. Simulation Augmented Manoeuvring Design and Monitoring - a New Method for Advanced Ship Handling

    Directory of Open Access Journals (Sweden)

    Knud Benedict

    2014-03-01

    Full Text Available A fast time simulation tool box is under development to simulate the ships motion with complex dynamic models and to display the ships track immediately for the intended or actual rudder or engine manoeuvre. Based on this approach the innovative Simulation Augmented Manoeuvring Design and Monitoring - SAMMON tool box will allow for (a a new type of design of a manoeuvring plan as enhancement exceeding the common pure way point planning (b an unmatched monitoring of ship handling processes to follow the underlying manoeuvring plan. During the manoeuvring process the planned manoeuvres can be constantly displayed together with the actual ship motion and the predicted future track which is based on actual input data from the ship's sensors and manoeuvring handle positions. This SAMMON tool box is intended be used on board of real ships but it is in parallel an effective tool for training in ship handling simulators: (a in the briefing for preparing a manoeuvring plan for the whole exercise in some minutes, (b during the exercise run to see the consequences of the use of manoeuvring equipment even before the ship has changed her motion and (c in debriefing sessions to discuss potential alternatives of the students decisions by simulating fast variations of their choices during the exercises. Examples will be given for results from test trials on board and in the full mission ship handling simulator of the Maritime Simulation Centre Warnemuende.

  11. TNO ADVANCE: a modular simulation tool for combined chassis and powertrain analysis

    NARCIS (Netherlands)

    Tillaart, E. van den; Mourad, S.; Lupker, H.

    2001-01-01

    In this paper TNO-Advance is presented. It is built in a modular way, therefore allowing quick assembling of specific vehicle configurations and easy integration of new component models and future evolutions of existing models. Its entensive library is built in Matlab/Simulink, taking advantage of i

  12. Recent advances in gyrokinetic full-f particle simulation of medium sized Tokamaks with ELMFIRE

    International Nuclear Information System (INIS)

    Large-scale kinetic simulations of toroidal plasmas based on first principles are called for in studies of transition from low to high confinement mode and internal transport barrier formation in the core plasma. Such processes are best observed and diagnosed in detached plasma conditions in mid-sized tokamaks, so gyrokinetic simulations for these conditions are warranted. A first principles test-particle based kinetic model ELMFIRE[1] has been developed and used in interpretation[1,2] of FT-2 and DIII-D experiments. In this work we summarize progress in Cyclone (DIII-D core) and ASDEX Upgrade pedestal region simulations, and show that in simulations the choice of adiabatic electrons results in quenching of turbulence (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Recent advances in gyrokinetic full-f particle simulation of medium sized Tokamaks with ELMFIRE

    Energy Technology Data Exchange (ETDEWEB)

    Janhunen, S.J.; Kiviniemi, T.P.; Korpio, T.; Leerink, S.; Nora, M. [Helsinki University of Technology, Euratom-Tekes Association, Espoo (Finland); Heikkinen, J.A. [VTT, Euratom-Tekes Association, Espoo (Finland); Ogando, F. [Helsinki University of Technology, Euratom-Tekes Association, Espoo (Finland); Universidad Nacional de Educacion a Distancia, Madrid (Spain)

    2010-05-15

    Large-scale kinetic simulations of toroidal plasmas based on first principles are called for in studies of transition from low to high confinement mode and internal transport barrier formation in the core plasma. Such processes are best observed and diagnosed in detached plasma conditions in mid-sized tokamaks, so gyrokinetic simulations for these conditions are warranted. A first principles test-particle based kinetic model ELMFIRE[1] has been developed and used in interpretation[1,2] of FT-2 and DIII-D experiments. In this work we summarize progress in Cyclone (DIII-D core) and ASDEX Upgrade pedestal region simulations, and show that in simulations the choice of adiabatic electrons results in quenching of turbulence (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Advances in simulated modeling of vibration systems based on computational intelligence

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Computational intelligence is the computational simulation of the bio-intelligence, which includes artificial neural networks, fuzzy systems and evolutionary computations. This article summarizes the state of the art in the field of simulated modeling of vibration systems using methods of computational intelligence, based on some relevant subjects and the authors' own research work. First, contributions to the applications of computational intelligence to the identification of nonlinear characteristics of packaging are reviewed. Subsequently, applications of the newly developed training algorithms for feedforward neural networks to the identification of restoring forces in multi-degree-of-freedom nonlinear systems are discussed. Finally, the neural-network-based method of model reduction for the dynamic simulation of microelectromechanical systems (MEMS) using generalized Hebbian algorithm (GHA) and robust GHA is outlined. The prospects of the simulated modeling of vibration systems using techniques of computational intelligence are also indicated.

  15. Akuna - Integrated Toolsets Supporting Advanced Subsurface Flow and Transport Simulations for Environmental Management

    Energy Technology Data Exchange (ETDEWEB)

    Schuchardt, Karen L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Agarwal, Deborah A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Finsterle, Stefan A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gable, Carl W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gorton, Ian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gosink, Luke J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Keating, Elizabeth H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lansing, Carina S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Meyer, Joerg [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Moeglein, William A.M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pau, George S.H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Porter, Ellen A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Purohit, Sumit [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rockhold, Mark L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Shoshani, Arie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sivaramakrishnan, Chandrika [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2012-04-24

    A next generation open source subsurface simulator and user environment for environmental management is being developed through a collaborative effort across Department of Energy National Laboratories. The flow and transport simulator, Amanzi, will be capable of modeling complex subsurface environments and processes using both unstructured and adaptive meshes at very fine spatial resolutions that require supercomputing-scale resources. The user environment, Akuna, provides users with a range of tools to manage environmental and simulator data sets, create models, manage and share simulation data, and visualize results. Underlying the user interface are core toolsets that provide algorithms for sensitivity analysis, parameter estimation, and uncertainty quantification. Akuna is open-source, cross platform software that is initially being demonstrated on the Hanford BC Cribs remediation site. In this paper, we describe the emerging capabilities of Akuna and illustrate how these are being applied to the BC Cribs site.

  16. Advances in large-eddy simulation of a wind turbine wake

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, A; Crespo, A; Migoya, E; Garcia, J [Departamento de IngenierIa Energetica y Fluidomecanica, ETSII, Universidad iPolitecnica de Madrid. C/Jose Gutierrez Abascal, 2, CP., 28006, Madrid (Spain)

    2007-07-15

    A CFD code has been developed based on a Large-Eddy Simulation (LES) approach. The turbine is simulated by concentrated drag forces, and is placed in an environment with turbulence anisotropy properties similar to the ones of the real atmosphere. Comparisons with experimental data and with analytical correlations have been performed, and the results are found to be in good agreement with both, suggesting that LES is a potentially useful tool in the investigation of detailed wake flow.

  17. CORBA and MPI-based 'backbone' for coupling advanced simulation tools

    International Nuclear Information System (INIS)

    There is a growing international interest in using coupled, multidisciplinary computer simulations for a variety of purposes, including nuclear reactor safety analysis. Reactor behaviour can be modeled using a suite of computer programs simulating phenomena or predicting parameters that can be categorized into disciplines such as Thermalhydraulics, Neutronics, Fuel, Fuel Channels, Fission Product Release and Transport, Containment and Atmospheric Dispersion, and Severe Accident Analysis. Traditionally, simulations used for safety analysis individually addressed only the behaviour within a single discipline, based upon static input data from other simulation programs. The limitation of using a suite of stand-alone simulations is that phenomenological interdependencies or temporal feedback between the parameters calculated within individual simulations cannot be adequately captured. To remove this shortcoming, multiple computer simulations for different disciplines must exchange data during runtime to address these interdependencies. This article describes the concept of a new framework, which we refer to as the 'Backbone', to provide the necessary runtime exchange of data. The Backbone, currently under development at AECL for a preliminary feasibility study, is a hybrid design using features taken from the Common Object Request Broker Architecture (CORBA), a standard defined by the Object Management Group, and the Message Passing Interface (MPI), a standard developed by a group of researchers from academia and industry. Both have well-tested and efficient implementations, including some that are freely available under the GNU public licenses. The CORBA component enables individual programs written in different languages and running on different platforms within a network to exchange data with each other, thus behaving like a single application. MPI provides the process-to-process intercommunication between these programs. This paper outlines the different CORBA and

  18. A study on optimization of hybrid drive train using Advanced Vehicle Simulator (ADVISOR)

    Science.gov (United States)

    Same, Adam; Stipe, Alex; Grossman, David; Park, Jae Wan

    This study investigates the advantages and disadvantages of three hybrid drive train configurations: series, parallel, and "through-the-ground" parallel. Power flow simulations are conducted with the MATLAB/Simulink-based software ADVISOR. These simulations are then applied in an application for the UC Davis SAE Formula Hybrid vehicle. ADVISOR performs simulation calculations for vehicle position using a combined backward/forward method. These simulations are used to study how efficiency and agility are affected by the motor, fuel converter, and hybrid configuration. Three different vehicle models are developed to optimize the drive train of a vehicle for three stages of the SAE Formula Hybrid competition: autocross, endurance, and acceleration. Input cycles are created based on rough estimates of track geometry. The output from these ADVISOR simulations is a series of plots of velocity profile and energy storage State of Charge that provide a good estimate of how the Formula Hybrid vehicle will perform on the given course. The most noticeable discrepancy between the input cycle and the actual velocity profile of the vehicle occurs during deceleration. A weighted ranking system is developed to organize the simulation results and to determine the best drive train configuration for the Formula Hybrid vehicle. Results show that the through-the-ground parallel configuration with front-mounted motors achieves an optimal balance of efficiency, simplicity, and cost. ADVISOR is proven to be a useful tool for vehicle power train design for the SAE Formula Hybrid competition. This vehicle model based on ADVISOR simulation is applicable to various studies concerning performance and efficiency of hybrid drive trains.

  19. Aligned spin neutron star-black hole mergers: A gravitational waveform amplitude model

    Science.gov (United States)

    Pannarale, Francesco; Berti, Emanuele; Kyutoku, Koutarou; Lackey, Benjamin D.; Shibata, Masaru

    2015-10-01

    The gravitational radiation emitted during the merger of a black hole with a neutron star is rather similar to the radiation from the merger of two black holes when the neutron star is not tidally disrupted. When tidal disruption occurs, gravitational waveforms can be broadly classified in two groups, depending on the spatial extent of the disrupted material. Extending previous work by some of us, here we present a phenomenological model for the gravitational waveform amplitude in the frequency domain encompassing the three possible outcomes of the merger: no tidal disruption, and "mild" and "strong" tidal disruption. The model is calibrated to 134 general-relativistic numerical simulations of binaries where the black hole spin is either aligned or antialigned with the orbital angular momentum. All simulations were produced using the SACRA code and piecewise polytropic neutron star equations of state. The present model can be used to determine when black-hole binary waveforms are sufficient for gravitational-wave detection, to extract information on the equation of state from future gravitational-wave observations, to obtain more accurate estimates of black hole-neutron star merger event rates, and to determine the conditions under which these systems are plausible candidates as central engines of gamma-ray bursts and macronovae/kilonovae.

  20. Advanced Variance Reduction for Global k-Eigenvalue Simulations in MCNP

    International Nuclear Information System (INIS)

    between fission source estimates. In the new FMC method, the eigenvalue problem (expressed in terms of the Boltzmann equation) is integrated over the energy and direction variables. Then these equations are multiplied by J special 'tent' functions in space and integrated over the spatial variable. This yields J equations that are exactly satisfied by the eigenvalue k and J space-angle-energy moments of the eigenfunction. Multiplying and dividing by suitable integrals of the eigenfunction, one obtains J algebraic equations for k and the space-angle-energy moments of the eigenfunction, which contain nonlinear functionals that depend weakly on the eigenfunction. In the FMC method, information from the standard Monte Carlo solution for each active cycle is used to estimate the functionals, and at the end of each cycle the J equations for k and the space-angle-energy moments of the eigenfunction are solved. Finally, these results are averaged over N active cycles to obtain estimated means and standard deviations for k and the space-angle-energy moments of the eigenfunction. Our limited testing shows that for large single fissile systems such as a commercial reactor core, (i) the FMC estimate of the eigenvalue is at least one order of magnitude more accurate than estimates obtained from the standard Monte Carlo approach, (ii) the FMC estimate of the eigenfunction converges and is several orders of magnitude more accurate than the standard estimate, and (iii) the FMC estimate of the standard deviation in k is at least one order of magnitude closer to the correct standard deviation than the standard estimate. These advances occur because: (i) the Monte Carlo estimates of the nonlinear functionals are much more accurate than the direct Monte Carlo estimates of the eigenfunction, (ii) the system of discrete equations that determines the FMC estimates of k is robust, and (iii) the functionals are only very weakly correlated between different fission generations. The FMC method was

  1. Advanced CFD simulations of turbulent flows around appendages in CANDU fuel bundles

    International Nuclear Information System (INIS)

    Computational Fluid Dynamics (CFD) was used to simulate the coolant flow in a modified 37-element CANDU fuel bundle, in order to investigate the effects of the appendages on the flow field. First, a subchannel model was created to qualitatively analyze the capabilities of different turbulence models such as k.ε, Reynolds Normalization Group (RNG), Shear Stress Transport (SST) and Large Eddy Simulation (LES). Then, the turbulence model with the acceptable quality was used to investigate the effects of positioning appendages, normally used in CANDU 37-element Critical Heat Flux (CHF) experiments, on the flow field. It was concluded that the RNG and SST models both show improvements over the k.ε method by predicting cross flow rates closer to those predicted by the LES model. Also the turbulence effects in the k.ε model dissipate quickly downstream of the appendages, while in the RNG and SST models appear at longer distances similar to the LES model. The RNG method simulation time was relatively feasible and as a result was chosen for the bundle model simulations. In the bundle model simulations it was shown that the tunnel spacers and leaf springs, used to position the bundles inside the pressure tubes in the experiments, have no measureable dominant effects on the flow field. The flow disturbances are localized and disappear at relatively short streamwise distances. (author)

  2. SciDAC Advances in Beam Dynamics Simulation: From Light Sources to Colliders

    International Nuclear Information System (INIS)

    In this paper, we report on progress that has been made in beam dynamics simulation, from light sources to colliders, during the first year of the SciDAC-2 accelerator project 'Community Petascale Project for Accelerator Science and Simulation (ComPASS).' Several parallel computational tools for beam dynamics simulation are described. Also presented are number of applications in current and future accelerator facilities (e.g., LCLS, RHIC, Tevatron, LHC, and ELIC). Particle accelerators are some of most important tools of scientific discovery. They are widely used in high-energy physics, nuclear physics, and other basic and applied sciences to study the interaction of elementary particles, to probe the internal structure of matter, and to generate high-brightness radiation for research in materials science, chemistry, biology, and other fields. Modern accelerators are complex and expensive devices that may be several kilometers long and may consist of thousands of beamline elements. An accelerator may transport trillions of charged particles that interact electromagnetically among themselves, that interact with fields produced by the accelerator components, and that interact with beam-induced fields. Large-scale beam dynamics simulations on massively parallel computers can help provide understanding of these complex physical phenomena, help minimize design cost, and help optimize machine operation. In this paper, we report on beam dynamics simulations in a variety of accelerators ranging from next generation light sources to high-energy ring colliders that have been studied during the first year of the SciDAC-2 accelerator project.

  3. Numerical models for the simulation of the cyclic behaviour of RC structures incorporating new advanced materials

    OpenAIRE

    Varma, Rajendra Kumar

    2013-01-01

    Tese de doutoramento em Estrutural Engenharia This work deals with material modelling and numerical implementation for nonlinear finite element analysis of reinforced concrete (RC) structures. Since the behaviour of concrete and steel being crucial for any RC structure under loading, uniaxial cyclic constitutive models for both were implemented in FEMIX, finite element software. Various advanced materials have been developed with specific purposes, like fibre reinforced c...

  4. Investigation of advanced strain-path dependent material models for sheet metal forming simulations

    OpenAIRE

    Haddag, Badis; BALAN, Tudor; ABED-MERAIM, Farid

    2006-01-01

    Sheet metal forming processes often involve complex loading sequences. To improve the prediction of some undesirable phenomena, such as springback, physical behavior models should be considered. This paper investigates springback behavior predicted by advanced elastoplastic hardening models which combine isotropic and kinematic hardening and take strain-path changes into account. A dislocation-based microstructural hardening model formulated from physical observations and the more classical c...

  5. Discrete event simulation methods applied to advanced importance measures of repairable components in multistate network flow systems

    International Nuclear Information System (INIS)

    Discrete event models are frequently used in simulation studies to model and analyze pure jump processes. A discrete event model can be viewed as a system consisting of a collection of stochastic processes, where the states of the individual processes change as results of various kinds of events occurring at random points of time. We always assume that each event only affects one of the processes. Between these events the states of the processes are considered to be constant. In the present paper we use discrete event simulation in order to analyze a multistate network flow system of repairable components. In order to study how the different components contribute to the system, it is necessary to describe the often complicated interaction between component processes and processes at the system level. While analytical considerations may throw some light on this, a simulation study often allows the analyst to explore more details. By producing stable curve estimates for the development of the various processes, one gets a much better insight in how such systems develop over time. These methods are particulary useful in the study of advanced importancez measures of repairable components. Such measures can be very complicated, and thus impossible to calculate analytically. By using discrete event simulations, however, this can be done in a very natural and intuitive way. In particular significant differences between the Barlow–Proschan measure and the Natvig measure in multistate network flow systems can be explored

  6. Quantifying the Effect of Fast Charger Deployments on Electric Vehicle Utility and Travel Patterns via Advanced Simulation: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wood, E.; Neubauer, J.; Burton, E.

    2015-02-01

    The disparate characteristics between conventional (CVs) and battery electric vehicles (BEVs) in terms of driving range, refill/recharge time, and availability of refuel/recharge infrastructure inherently limit the relative utility of BEVs when benchmarked against traditional driver travel patterns. However, given a high penetration of high-power public charging combined with driver tolerance for rerouting travel to facilitate charging on long-distance trips, the difference in utility between CVs and BEVs could be marginalized. We quantify the relationships between BEV utility, the deployment of fast chargers, and driver tolerance for rerouting travel and extending travel durations by simulating BEVs operated over real-world travel patterns using the National Renewable Energy Laboratory's Battery Lifetime Analysis and Simulation Tool for Vehicles (BLAST-V). With support from the U.S. Department of Energy's Vehicle Technologies Office, BLAST-V has been developed to include algorithms for estimating the available range of BEVs prior to the start of trips, for rerouting baseline travel to utilize public charging infrastructure when necessary, and for making driver travel decisions for those trips in the presence of available public charging infrastructure, all while conducting advanced vehicle simulations that account for battery electrical, thermal, and degradation response. Results from BLAST-V simulations on vehicle utility, frequency of inserted stops, duration of charging events, and additional time and distance necessary for rerouting travel are presented to illustrate how BEV utility and travel patterns can be affected by various fast charge deployments.

  7. A waveform covariancematrix for high SINR and lowside-lobe levels

    KAUST Repository

    Ahmed, Sajid

    2013-05-01

    In this work to exploit the benefits of both multiple-input multiple-output (MIMO)-radar and phased-array a waveform covariance matrix is proposed. Our analytical results show that the proposed covariance matrix yields gain in signal-to-interference-plus-noise ratio (SINR) compared to MIMO-radar while the gain in SINR is close to phased-array and recently proposed phased-MIMO scheme. Transmitted waveforms with the proposed covariance matrix, at the receiver, significantly supress the side-lobe levels compared to phased-array, MIMO-radar, and phased-MIMO schemes. Moreover, in contrast to phased-MIMO our proposed scheme allows same power transmission from each antenna. Simulation results validate the analytical results. © 2013 IEEE.

  8. Sparse-promoting Full Waveform Inversion based on Online Orthonormal Dictionary Learning

    CERN Document Server

    Zhu, Lingchen; McClellan, James H

    2015-01-01

    Full waveform inversion (FWI) delivers high-resolution images of a subsurface medium model by minimizing iteratively the least-squares misfit between the observed and simulated seismic data. Due to the limited accuracy of the starting model and the inconsistency of the seismic waveform data, the FWI problem is inherently ill-posed, so that regularization techniques are typically applied to obtain better models. FWI is also a computationally expensive problem because modern seismic surveys cover very large areas of interest and collect massive volumes of data. The dimensionality of the problem and the heterogeneity of the medium both stress the need for faster algorithms and sparse regularization techniques to accelerate and improve imaging results. This paper reaches these goals by developing a compressive sensing approach for the FWI problem, where the sparsity of model perturbations is exploited within learned dictionaries. Based on stochastic approximations, the dictionaries are updated iteratively to adap...

  9. Variable density sampling based on physically plausible gradient waveform. Application to 3D MRI angiography

    CERN Document Server

    Chauffert, Nicolas; Boucher, Marianne; Mériaux, Sébastien; CIUCIU, Philippe

    2015-01-01

    Performing k-space variable density sampling is a popular way of reducing scanning time in Magnetic Resonance Imaging (MRI). Unfortunately, given a sampling trajectory, it is not clear how to traverse it using gradient waveforms. In this paper, we actually show that existing methods [1, 2] can yield large traversal time if the trajectory contains high curvature areas. Therefore, we consider here a new method for gradient waveform design which is based on the projection of unrealistic initial trajectory onto the set of hardware constraints. Next, we show on realistic simulations that this algorithm allows implementing variable density trajectories resulting from the piecewise linear solution of the Travelling Salesman Problem in a reasonable time. Finally, we demonstrate the application of this approach to 2D MRI reconstruction and 3D angiography in the mouse brain.

  10. Twisted X-rays: incoming waveforms yielding discrete diffraction patterns for helical structures

    CERN Document Server

    Friesecke, Gero; Jüstel, Dominik

    2015-01-01

    Conventional X-ray methods use incoming plane waves and result in discrete diffraction patterns when scattered at crystals. Here we find, by a systematic method, incoming waveforms which exhibit discrete diffraction patterns when scattered at helical structures. As examples we present simulated diffraction patterns of carbon nanotubes and tobacco mosaic virus. The new incoming waveforms, which we call twisted waves due to their geometric shape, are found theoretically as closed-form solutions to Maxwell's equations. The theory of the ensuing diffraction patterns is developed in detail. A twisted analogue of the Von Laue condition is seen to hold, with the peak locations encoding the symmetry and the helix parameters, and the peak intensities indicating the electronic structure in the unit cell. If suitable twisted X-ray sources can in the future be realized experimentally, it appears from our mathematical results that they will provide a powerful tool for directly determining the detailed atomic structure of ...

  11. Advanced methods in global gyrokinetic full f particle simulation of tokamak transport

    International Nuclear Information System (INIS)

    A new full f nonlinear gyrokinetic simulation code, named ELMFIRE, has been developed for simulating transport phenomena in tokamak plasmas. The code is based on a gyrokinetic particle-in-cell algorithm, which can consider electrons and ions jointly or separately, as well as arbitrary impurities. The implicit treatment of the ion polarization drift and the use of full f methods allow for simulations of strongly perturbed plasmas including wide orbit effects, steep gradients and rapid dynamic changes. This article presents in more detail the algorithms incorporated into ELMFIRE, as well as benchmarking comparisons to both neoclassical theory and other codes.Code ELMFIRE calculates plasma dynamics by following the evolution of a number of sample particles. Because of using an stochastic algorithm its results are influenced by statistical noise. The effect of noise on relevant magnitudes is analyzed.Turbulence spectra of FT-2 plasma has been calculated with ELMFIRE, obtaining results consistent with experimental data

  12. Validation of advanced NSSS simulator model for loss-of-coolant accidents

    Energy Technology Data Exchange (ETDEWEB)

    Kao, S.P.; Chang, S.K.; Huang, H.C. [Nuclear Training Branch, Northeast Utilities, Waterford, CT (United States)

    1995-09-01

    The replacement of the NSSS (Nuclear Steam Supply System) model on the Millstone 2 full-scope simulator has significantly increased its fidelity to simulate adverse conditions in the RCS. The new simulator NSSS model is a real-time derivative of the Nuclear Plant Analyzer by ABB. The thermal-hydraulic model is a five-equation, non-homogeneous model for water, steam, and non-condensible gases. The neutronic model is a three-dimensional nodal diffusion model. In order to certify the new NSSS model for operator training, an extensive validation effort has been performed by benchmarking the model performance against RELAP5/MOD2. This paper presents the validation results for the cases of small-and large-break loss-of-coolant accidents (LOCA). Detailed comparisons in the phenomena of reflux-condensation, phase separation, and two-phase natural circulation are discussed.

  13. Generation of correlated finite alphabet waveforms using gaussian random variables

    KAUST Repository

    Jardak, Seifallah

    2014-09-01

    Correlated waveforms have a number of applications in different fields, such as radar and communication. It is very easy to generate correlated waveforms using infinite alphabets, but for some of the applications, it is very challenging to use them in practice. Moreover, to generate infinite alphabet constant envelope correlated waveforms, the available research uses iterative algorithms, which are computationally very expensive. In this work, we propose simple novel methods to generate correlated waveforms using finite alphabet constant and non-constant-envelope symbols. To generate finite alphabet waveforms, the proposed method map the Gaussian random variables onto the phase-shift-keying, pulse-amplitude, and quadrature-amplitude modulation schemes. For such mapping, the probability-density-function of Gaussian random variables is divided into M regions, where M is the number of alphabets in the corresponding modulation scheme. By exploiting the mapping function, the relationship between the cross-correlation of Gaussian and finite alphabet symbols is derived. To generate equiprobable symbols, the area of each region is kept same. If the requirement is to have each symbol with its own unique probability, the proposed scheme allows us that as well. Although, the proposed scheme is general, the main focus of this paper is to generate finite alphabet waveforms for multiple-input multiple-output radar, where correlated waveforms are used to achieve desired beampatterns. © 2014 IEEE.

  14. Source-independent elastic waveform inversion using a logarithmic wavefield

    KAUST Repository

    Choi, Yun Seok

    2012-01-01

    The logarithmic waveform inversion has been widely developed and applied to some synthetic and real data. In most logarithmic waveform inversion algorithms, the subsurface velocities are updated along with the source estimation. To avoid estimating the source wavelet in the logarithmic waveform inversion, we developed a source-independent logarithmic waveform inversion algorithm. In this inversion algorithm, we first normalize the wavefields with the reference wavefield to remove the source wavelet, and then take the logarithm of the normalized wavefields. Based on the properties of the logarithm, we define three types of misfit functions using the following methods: combination of amplitude and phase, amplitude-only, and phase-only. In the inversion, the gradient is computed using the back-propagation formula without directly calculating the Jacobian matrix. We apply our algorithm to noise-free and noise-added synthetic data generated for the modified version of elastic Marmousi2 model, and compare the results with those of the source-estimation logarithmic waveform inversion. For the noise-free data, the source-independent algorithms yield velocity models close to true velocity models. For random-noise data, the source-estimation logarithmic waveform inversion yields better results than the source-independent method, whereas for coherent-noise data, the results are reversed. Numerical results show that the source-independent and source-estimation logarithmic waveform inversion methods have their own merits for random- and coherent-noise data. © 2011.

  15. Simulation of Electric Faults in Doubly-Fed Induction Generators Employing Advanced Mathematical Modelling

    DEFF Research Database (Denmark)

    Martens, Sebastian; Mijatovic, Nenad; Holbøll, Joachim;

    2015-01-01

    many areas of electrical machine analysis. However, for fault investigations, the phase-coordinate representation has been found more suitable. This paper presents a mathematical model in phase coordinates of the DFIG with two parallel windings per rotor phase. The model has been implemented in Matlab...... and its properties in context of fault simulations and investigations has been investigated. Some of the most common faults have been simulated, namely broken rotor bars or windings, dynamic eccentricities and stator phase winding short circuits. These fault conditions propagate to the stator current...

  16. A review of recent advances in numerical simulations of microscale fuel processor for hydrogen production

    Science.gov (United States)

    Holladay, J. D.; Wang, Y.

    2015-05-01

    Microscale (methanol as the fuel due to methanol's low reforming temperature and high conversion, although, there are several methane fueled systems. The increased computational power and more complex codes have led to improved accuracy of numerical simulations. Initial models focused on the reformer, while more recently, the simulations began including other unit operations such as vaporizers, inlet manifolds, and combustors. These codes are critical for developing the next generation systems. The systems reviewed included plate reactors, microchannel reactors, and annulus reactors for both wash-coated and packed bed systems.

  17. Material properties of low pressure chemical vapor deposited silicon nitride for modeling and calibrating the simulation of advanced isolation structures

    Science.gov (United States)

    Smeys, Peter I. L.; Griffin, Peter B.; Saraswat, Krishna C.

    1995-08-01

    The increasing cost and complexity of semiconductor process development has lead to the widespread use of multidimensional semiconductor process simulators. The success of a program like SUPREM-IV is primarily due to the fact that it is based on physical models, rather than empirical equations. This is in contrast to the first generation of process simulators, which calculated impurity profiles and oxide thickness in one dimension based on semiempirical approaches. SUPREM-IV incorporates two-dimensional coupled stress-dependent oxidation and impurity diffusion, which allows the accurate simulations of state-of-the-art integrated processes, provided that accurate model parameter sets are available. In this article we present an improved calibration methodology for simulation of advanced isolation technologies using SUPREM-IV, based on the experimental determination of the material properties of silicon nitride. The proposed strategy is applicable not only to SUPREM-IV but to any numerical simulator that uses the stress-dependent oxidation models to calculate oxide growth. In order to simulate experimental isolation boundary shapes, the oxidation models in SUPREM-IV must be calibrated. This requires a set of five fitting parameters, i.e., the material viscosities and activation volumes for stress-dependent diffusion, reaction rate, and critical stress. These parameters form a quintuplet but are not unique. Multiplying the viscosity values and dividing the activation volumes by a constant will yield exactly the same isolation structure boundary shape. The calculated stresses in the substrate however do not remain constant when different quintuplets are used. This has serious implications since isolation structures require the stress levels in the silicon substrate to remain well below the yield stress of silicon. If a nonoptimal parameter set is used, incorrect designs will result. Based on the experimental extraction of the silicon nitride viscosity by measuring the

  18. Development of Lightning Simulator

    CERN Document Server

    Uehara, Shigeki

    2014-01-01

    In this work we have developed a lightning simulator. Reproducing the light of lightning, we adopted seven waveforms that contains two light waveforms and five current waveforms of lightning. Furthermore, the lightning simulator can calibrate the color of the simulated light output based on a correlated color temperature (CCT). The CCT of the simulated light can range over from $4269$ K to $15042$ K. It is considered that the lightning simulator is useful for the test light source of the optical/image sensor of the lightning observation. Also for science education (e.g. physics education and earth science education etc.), the lightning simulator is available. Especially, the temporal change can be slowly seen by expanding the time scale from microsecond to second.

  19. CFD simulations of moderator flow inside Calandria of the Passive Moderator Cooling System of an advanced reactor

    Energy Technology Data Exchange (ETDEWEB)

    Pal, Eshita [Homi Bhabha National Institute, Anushaktinagar, Mumbai 400 094 (India); Kumar, Mukesh [Reactor Engineering Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India); Joshi, Jyeshtharaj B., E-mail: jbjoshi@gmail.com [Homi Bhabha National Institute, Anushaktinagar, Mumbai 400 094 (India); Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai 400019 India (India); Nayak, Arun K. [Reactor Engineering Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India); Vijayan, Pallippattu K., E-mail: vijayanp@barc.gov.in [Reactor Engineering Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India)

    2015-10-15

    Highlights: • CFD simulations in the Calandria of an advanced reactor under natural circulation. • Under natural convection, majority of the flow recirculates within the Calandria. • Maximum temperature is located at the top and center of the fuel channel matrix. • During SBO, temperature inside Calandria is stratified. - Abstract: Passive systems are being examined for the future Advanced Nuclear Reactor designs. One of such concepts is the Passive Moderator Cooling System (PMCS), which is designed to remove heat from the moderator in the Calandria vessel passively in case of an extended Station Black Out condition. The heated heavy-water moderator (due to heat transferred from the Main Heat Transport System (MHTS) and thermalization of neutrons and gamma from radioactive decay of fuel) rises upward due to buoyancy, gets cooled down in a heat exchanger and returns back to Calandria, completing a natural circulation loop. The natural circulation should provide sufficient cooling to prevent the increase of moderator temperature and pressure beyond safe limits. In an earlier study, a full-scale 1D transient simulation was performed for the reactor including the MHTS and the PMCS, in the event of a station blackout scenario (Kumar et al., 2013). The results indicate that the systems remain within the safe limits for 7 days. However, the flow inside a geometry like Calandria is quite complex due to its large size and inner complexities of dense fuel channel matrix, which was simplified as a 1D pipe flow in the aforesaid analysis. In the current work, CFD simulations are performed to study the temperature distributions and flow distribution of moderator inside the Calandria vessel using a three-dimensional CFD code, OpenFoam 2.2.0. First, a set of steady state simulation was carried out for a band of inlet mass flow rates, which gives the minimum mass flow rate required for removing the maximum heat load, by virtue of prediction of hot spots inside the Calandria

  20. CFD simulations of moderator flow inside Calandria of the Passive Moderator Cooling System of an advanced reactor

    International Nuclear Information System (INIS)

    Highlights: • CFD simulations in the Calandria of an advanced reactor under natural circulation. • Under natural convection, majority of the flow recirculates within the Calandria. • Maximum temperature is located at the top and center of the fuel channel matrix. • During SBO, temperature inside Calandria is stratified. - Abstract: Passive systems are being examined for the future Advanced Nuclear Reactor designs. One of such concepts is the Passive Moderator Cooling System (PMCS), which is designed to remove heat from the moderator in the Calandria vessel passively in case of an extended Station Black Out condition. The heated heavy-water moderator (due to heat transferred from the Main Heat Transport System (MHTS) and thermalization of neutrons and gamma from radioactive decay of fuel) rises upward due to buoyancy, gets cooled down in a heat exchanger and returns back to Calandria, completing a natural circulation loop. The natural circulation should provide sufficient cooling to prevent the increase of moderator temperature and pressure beyond safe limits. In an earlier study, a full-scale 1D transient simulation was performed for the reactor including the MHTS and the PMCS, in the event of a station blackout scenario (Kumar et al., 2013). The results indicate that the systems remain within the safe limits for 7 days. However, the flow inside a geometry like Calandria is quite complex due to its large size and inner complexities of dense fuel channel matrix, which was simplified as a 1D pipe flow in the aforesaid analysis. In the current work, CFD simulations are performed to study the temperature distributions and flow distribution of moderator inside the Calandria vessel using a three-dimensional CFD code, OpenFoam 2.2.0. First, a set of steady state simulation was carried out for a band of inlet mass flow rates, which gives the minimum mass flow rate required for removing the maximum heat load, by virtue of prediction of hot spots inside the Calandria

  1. High Level Requirements for the Nuclear Energy -- Knowledge Base for Advanced Modeling and Simulation (NE-KAMS)

    Energy Technology Data Exchange (ETDEWEB)

    Rich Johnson; Hyung Lee; Kimberlyn C. Mousseau

    2011-09-01

    The US Department of Energy, Office of Nuclear Energy (DOE-NE), has been tasked with the important mission of ensuring that nuclear energy remains a compelling and viable energy source in the U.S. The motivations behind this mission include cost-effectively meeting the expected increases in the power needs of the country, reducing carbon emissions and reducing dependence on foreign energy sources. In the near term, to ensure that nuclear power remains a key element of U.S. energy strategy and portfolio, the DOE-NE will be working with the nuclear industry to support safe and efficient operations of existing nuclear power plants. In the long term, to meet the increasing energy needs of the U.S., the DOE-NE will be investing in research and development (R&D) and working in concert with the nuclear industry to build and deploy new, safer and more efficient nuclear power plants. The safe and efficient operations of existing nuclear power plants and designing, licensing and deploying new reactor designs, however, will require focused R&D programs as well as the extensive use and leveraging of advanced modeling and simulation (M&S). M&S will play a key role in ensuring safe and efficient operations of existing and new nuclear reactors. The DOE-NE has been actively developing and promoting the use of advanced M&S in reactor design and analysis through its R&D programs, e.g., the Nuclear Energy Advanced Modeling and Simulation (NEAMS) and Consortium for Advanced Simulation of Light Water Reactors (CASL) programs. Also, nuclear reactor vendors are already using CFD and CSM, for design, analysis, and licensing. However, these M&S tools cannot be used with confidence for nuclear reactor applications unless accompanied and supported by verification and validation (V&V) and uncertainty quantification (UQ) processes and procedures which provide quantitative measures of uncertainty for specific applications. The Nuclear Energy Knowledge base for Advanced Modeling and Simulation

  2. Full Waveform Inversion of Solar Interior Flows

    CERN Document Server

    Hanasoge, Shravan M

    2014-01-01

    The inference of flows of material in the interior of the Sun is a subject of major interest in helioseismology. Here we apply techniques of Full Waveform Inversion (FWI) to synthetic data to test flow inversions. In this idealized setup, we do not model seismic realization noise, training the focus entirely on the problem of whether a chosen supergranulation flow model can be seismically recovered. We define the misfit functional as a sum of L_2 norm deviations in travel times between prediction and observation, as measured using short-distance f and p_1 filtered and large-distance unfiltered $p$ modes. FWI allows for the introduction of measurements of choice and iteratively improving the background model, while monitoring the evolution of the misfit in all desired categories. Although the misfit is seen to uniformly reduce in all categories, convergence to the true model is very slow, possibly because it is trapped in a local minimum. The primary source of error is inaccurate depth localization, which, owi...

  3. Comparison of simplified and advanced building simulation tool with measured data

    DEFF Research Database (Denmark)

    Christensen, Jørgen Erik; Schiønning, Peder; Dethlefsen, Espen

    2013-01-01

    In the future building design must progress to a format where CO 2 neutral societies are optimized as a whole and innovative technologies integrated. The purpose of this paper is to demonstrate the problems using a simplified design tool to simulate a complicated building and how this may not give...

  4. Advanced Signal Processing for Integrated LES-RANS Simulations: Anti-aliasing Filters

    Science.gov (United States)

    Schlueter, J. U.

    2003-01-01

    Currently, a wide variety of flow phenomena are addressed with numerical simulations. Many flow solvers are optimized to simulate a limited spectrum of flow effects effectively, such as single parts of a flow system, but are either inadequate or too expensive to be applied to a very complex problem. As an example, the flow through a gas turbine can be considered. In the compressor and the turbine section, the flow solver has to be able to handle the moving blades, model the wall turbulence, and predict the pressure and density distribution properly. This can be done by a flow solver based on the Reynolds-Averaged Navier-Stokes (RANS) approach. On the other hand, the flow in the combustion chamber is governed by large scale turbulence, chemical reactions, and the presence of fuel spray. Experience shows that these phenomena require an unsteady approach. Hence, for the combustor, the use of a Large Eddy Simulation (LES) flow solver is desirable. While many design problems of a single flow passage can be addressed by separate computations, only the simultaneous computation of all parts can guarantee the proper prediction of multi-component phenomena, such as compressor/combustor instability and combustor/turbine hot-streak migration. Therefore, a promising strategy to perform full aero-thermal simulations of gas-turbine engines is the use of a RANS flow solver for the compressor sections, an LES flow solver for the combustor, and again a RANS flow solver for the turbine section.

  5. RECENT ADVANCES OF UPSCALING METHODS FOR THE SIMULATION OF FLOW TRANSPORT THROUGH HETEROGENEOUS POROUS MEDIA

    Institute of Scientific and Technical Information of China (English)

    Zhiming Chen

    2006-01-01

    We review some of our recent efforts in developing upscaling methods for simulating the flow transport through heterogeneous porous media. In particular, the steady flow transport through highly heterogeneous porous media driven by extraction wells and the flow transport through unsaturated porous media will be considered.

  6. ANNUAL REPORT. DEVELOPMENT OF ADVANCED ELECTROCHEMICAL EMISSION SPECTROSCOPY FOR MONITORING CORROSION IN SIMULATED DOE LIQUID WASTE

    Science.gov (United States)

    The current report summarizes work performed on the project over the past calendar year (2001). The work concentrated on four areas: the fracture of AISI 4340 steel simulating weld heat affected zones in DOE liquid waste storage tanks, investigation of the passive state on nickel...

  7. Advances in Chimera Grid Tools for Multi-Body Dynamics Simulations and Script Creation

    Science.gov (United States)

    Chan, William M.

    2004-01-01

    This viewgraph presentation contains information about (1) Framework for multi-body dynamics - Geometry Manipulation Protocol (GMP), (2) Simulation procedure using Chimera Grid Tools (CGT) and OVERFLOW-2 (3) Further recent developments in Chimera Grid Tools OVERGRID, Grid modules, Script library and (4) Future work.

  8. Predicting Earthquake Occurrence at Subduction-Zone Plate Boundaries Through Advanced Computer Simulation

    Science.gov (United States)

    Matsu'Ura, M.; Hashimoto, C.; Fukuyama, E.

    2004-12-01

    In general, predicting the occurrence of earthquakes is very difficult, because of the complexity of actual faults and nonlinear interaction between them. From the standpoint of earthquake prediction, however, our target is limited to the large events that completely break down a seismogenic zone. To such large events we may apply the concept of the earthquake cycle. The entire process of earthquake generation cycles generally consists of tectonic loading due to relative plate motion, quasi-static rupture nucleation, dynamic rupture propagation and stop, and restoration of fault strength. This process can be completely described by a coupled nonlinear system, which consists of an elastic/viscoelastic slip-response function that relates fault slip to shear stress change and a fault constitutive law that prescribes change in shear strength with fault slip and contact time. The shear stress and the shear strength are related with each other through boundary conditions on the fault. The driving force of this system is observed relative plate motion. The system to describe the earthquake generation cycle is conceptually quite simple. The complexity in practical modeling mainly comes from complexity in structure of the real earth. Recently, we have developed a physics-based, predictive simulation system for earthquake generation at plate boundaries in and around Japan, where the four plates of Pacific, North American, Philippine Sea and Eurasian are interacting with each other. The simulation system consists of a crust-mantle structure model, a quasi-static tectonic loading model, and a dynamic rupture propagation model. First, we constructed a realistic 3D model of plate interfaces in and around Japan by applying an inversion technique to ISC hypocenter data, and computed viscoelastic slip-response functions for this structure model. Second, we introduced the slip- and time-dependent fault constitutive law with an inherent strength-restoration mechanism as a basic

  9. Data Collection Methods for Validation of Advanced Multi-Resolution Fast Reactor Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Tokuhiro, Akiro; Ruggles, Art; Pointer, David

    2015-01-22

    In pool-type Sodium Fast Reactors (SFR) the regions most susceptible to thermal striping are the upper instrumentation structure (UIS) and the intermediate heat exchanger (IHX). This project experimentally and computationally (CFD) investigated the thermal mixing in the region exiting the reactor core to the UIS. The thermal mixing phenomenon was simulated using two vertical jets at different velocities and temperatures as prototypic of two adjacent channels out of the core. Thermal jet mixing of anticipated flows at different temperatures and velocities were investigated. Velocity profiles are measured throughout the flow region using Ultrasonic Doppler Velocimetry (UDV), and temperatures along the geometric centerline between the jets were recorded using a thermocouple array. CFD simulations, using COMSOL, were used to initially understand the flow, then to design the experimental apparatus and finally to compare simulation results and measurements characterizing the flows. The experimental results and CFD simulations show that the flow field is characterized into three regions with respective transitions, namely, convective mixing, (flow direction) transitional, and post-mixing. Both experiments and CFD simulations support this observation. For the anticipated SFR conditions the flow is momentum dominated and thus thermal mixing is limited due to the short flow length associated from the exit of the core to the bottom of the UIS. This means that there will be thermal striping at any surface where poorly mixed streams impinge; rather unless lateral mixing is ‘actively promoted out of the core, thermal striping will prevail. Furthermore we note that CFD can be considered a ‘separate effects (computational) test’ and is recommended as part of any integral analysis. To this effect, poorly mixed streams then have potential impact on the rest of the SFR design and scaling, especially placement of internal components, such as the IHX that may see poorly mixed

  10. Data Collection Methods for Validation of Advanced Multi-Resolution Fast Reactor Simulations

    International Nuclear Information System (INIS)

    In pool-type Sodium Fast Reactors (SFR) the regions most susceptible to thermal striping are the upper instrumentation structure (UIS) and the intermediate heat exchanger (IHX). This project experimentally and computationally (CFD) investigated the thermal mixing in the region exiting the reactor core to the UIS. The thermal mixing phenomenon was simulated using two vertical jets at different velocities and temperatures as prototypic of two adjacent channels out of the core. Thermal jet mixing of anticipated flows at different temperatures and velocities were investigated. Velocity profiles are measured throughout the flow region using Ultrasonic Doppler Velocimetry (UDV), and temperatures along the geometric centerline between the jets were recorded using a thermocouple array. CFD simulations, using COMSOL, were used to initially understand the flow, then to design the experimental apparatus and finally to compare simulation results and measurements characterizing the flows. The experimental results and CFD simulations show that the flow field is characterized into three regions with respective transitions, namely, convective mixing, (flow direction) transitional, and post-mixing. Both experiments and CFD simulations support this observation. For the anticipated SFR conditions the flow is momentum dominated and thus thermal mixing is limited due to the short flow length associated from the exit of the core to the bottom of the UIS. This means that there will be thermal striping at any surface where poorly mixed streams impinge; rather unless lateral mixing is actively promoted out of the core, thermal striping will prevail. Furthermore we note that CFD can be considered a separate effects (computational) test and is recommended as part of any integral analysis. To this effect, poorly mixed streams then have potential impact on the rest of the SFR design and scaling, especially placement of internal components, such as the IHX that may see poorly mixed streams

  11. Recent advances in renal hypoxia: insights from bench experiments and computer simulations.

    Science.gov (United States)

    Layton, Anita T

    2016-07-01

    The availability of oxygen in renal tissue is determined by the complex interactions among a host of processes, including renal blood flow, glomerular filtration, arterial-to-venous oxygen shunting, medullary architecture, Na(+) transport, and oxygen consumption. When this delicate balance is disrupted, the kidney may become susceptible to hypoxic injury. Indeed, renal hypoxia has been implicated as one of the major causes of acute kidney injury and chronic kidney diseases. This review highlights recent advances in our understanding of renal hypoxia; some of these studies were published in response to a recent Call for Papers of this journal: Renal Hypoxia. PMID:27147670

  12. Assessing the performance of an advanced integrated facade by means of simulation: The ACTRESS facade case study

    Directory of Open Access Journals (Sweden)

    Fabio Favoino

    2015-11-01

    Full Text Available The growing demand for both building energy efficiency and indoor environmental comfort is leading to a substantial evolution of the traditional concept of the building envelope. The future building skin is required to be responsive and dynamic, actively regulating the flows of heat, light, air and water from outdoor to indoor and vice versa, in order to effectively respond to ever-changing climatic conditions, occupant comfort and energy efficiency requirements. In the framework of a decade-long research activity on Advanced Integrated Facade, AIF, a new Multifunctional Facade Module called ACTRESS has been conceived: the ACTive, RESponsive and Solar envelope is designedto play different roles through its ability to change its thermo-physical behaviour in order to suit the different environmental conditions. This paper briefly illustrates the ACTRESS MFM concept and its functional strategies, focusing on the simulation and the assessment of the performance of such a dynamic envelope. The numerical study was conducted in order to evaluate the potential energy savings achievable with such a facade and to evaluate different functional strategies and options. The evaluation of the performance in terms of energy savings was done at both component and whole-building level. Moreover this work presents an example of the applicability of Building Performance Simulation tools to the design of an innovative and dynamic facade system, discussing the capability of BPS software in simulating and evaluating the performance of such systems. The results show that the ACTRESS MFM can effectively reduce the total primary energy consumption of an office building up to 55% compared with a reference facade complying with national regulations. On the other hand modelling assumptions and simplifications are needed in order to evaluate the performance of such a system with BPS software, representing a barrier to the design and the adoption of advanced facade systems in

  13. Advanced fluid modelling and PIC/MCC simulations of low-pressure ccrf discharges

    CERN Document Server

    Becker, Markus M; Sun, Anbang; Bonitz, Michael; Loffhagen, Detlef

    2016-01-01

    Comparative studies of capacitively coupled radio-frequency discharges in helium and argon at pressures between 10 and 80 Pa are presented applying two different fluid modelling approaches as well as two independently developed particle-in-cell/Monte Carlo collision (PIC/MCC) codes. The focus is on the analysis of the range of applicability of a recently proposed fluid model including an improved drift-diffusion approximation for the electron component as well as its comparison with fluid modelling results using the classical drift-diffusion approximation and benchmark results obtained by PIC/MCC simulations. Main features of this time- and space-dependent fluid model are given. It is found that the novel approach shows generally quite good agreement with the macroscopic properties derived by the kinetic simulations and is largely able to characterize qualitatively and quantitatively the discharge behaviour even at conditions when the classical fluid modelling approach fails. Furthermore, the excellent agreem...

  14. Casting directly from a computer model by using advanced simulation software FLOW-3D Cast ®

    Directory of Open Access Journals (Sweden)

    M. Sirviö

    2009-01-01

    Full Text Available ConiferRob - A patternless casting technique, originally conceived at VTT Technical Research Centre of Finland and furtherdeveloped at its spin-off company, Simtech Systems, offers up to 40% savings in product development costs, and up to two months shorterdevelopment times compared to conventional techniques. Savings of this order can be very valuable on today's highly competitivemarkets. Casting simulation is commonly used for designing of casting systems. However, most of the software are today old fashioned and predicting just shrinkage porosity. Flow Science, VTT and Simtech have developed new software called FLOW-3D Cast ® , whichcan simulate surface defects, air entrainment, filters, core gas problems and even a cavitation.

  15. Springback Simulation: Impact of Some Advanced Constitutive Models and Numerical Parameters

    Science.gov (United States)

    Haddag, Badis; Balan, Tudor; Abed-Meraim, Farid

    2005-08-01

    The impact of material models on the numerical simulation of springback is investigated. The study is focused on the strain-path sensitivity of two hardening models. While both models predict the Bauschinger effect, their response in the transient zone after a strain-path change is fairly different. Their respective predictions are compared in terms of sequential test response and of strip-drawing springback. For this purpose, an accurate and general time integration algorithm has been developed and implemented in the Abaqus code. The impact of several numerical parameters is also studied in order to assess the overall accuracy of the finite element prediction. For some test geometries, both material and numerical parameters are shown to clearly influence the springback behavior at a large extent. Moreover, a general trend cannot always be extracted, thus justifying the need for the finite element simulation of the stamping process.

  16. Advanced time integration algorithms for dislocation dynamics simulations of work hardening

    Science.gov (United States)

    Sills, Ryan B.; Aghaei, Amin; Cai, Wei

    2016-05-01

    Efficient time integration is a necessity for dislocation dynamics simulations of work hardening to achieve experimentally relevant strains. In this work, an efficient time integration scheme using a high order explicit method with time step subcycling and a newly-developed collision detection algorithm are evaluated. First, time integrator performance is examined for an annihilating Frank–Read source, showing the effects of dislocation line collision. The integrator with subcycling is found to significantly out-perform other integration schemes. The performance of the time integration and collision detection algorithms is then tested in a work hardening simulation. The new algorithms show a 100-fold speed-up relative to traditional schemes. Subcycling is shown to improve efficiency significantly while maintaining an accurate solution, and the new collision algorithm allows an arbitrarily large time step size without missing collisions.

  17. A review of recent advances of numerical simulations of microscale fuel processors for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Holladay, Jamelyn D.; Wang, Yong

    2015-05-01

    Microscale (<5W) reformers for hydrogen production have been investigated for over a decade. These devices are intended to provide hydrogen for small fuel cells. Due to the reformer’s small size, numerical simulations are critical to understand heat and mass transfer phenomena occurring in the systems. This paper reviews the development of the numerical codes and details the reaction equations used. The majority of the devices utilized methanol as the fuel due to methanol’s low reforming temperature and high conversion, although, there are several methane fueled systems. As computational power has decreased in cost and increased in availability, the codes increased in complexity and accuracy. Initial models focused on the reformer, while more recently, the simulations began including other unit operations such as vaporizers, inlet manifolds, and combustors. These codes are critical for developing the next generation systems. The systems reviewed included, plate reactors, microchannel reactors, annulus reactors, wash-coated, packed bed systems.

  18. Casting directly from a computer model by using advanced simulation software FLOW-3D Cast ®

    OpenAIRE

    M. Sirviö; M. Woś

    2009-01-01

    ConiferRob - A patternless casting technique, originally conceived at VTT Technical Research Centre of Finland and furtherdeveloped at its spin-off company, Simtech Systems, offers up to 40% savings in product development costs, and up to two months shorterdevelopment times compared to conventional techniques. Savings of this order can be very valuable on today's highly competitivemarkets. Casting simulation is commonly used for designing of casting systems. However, most of the software are ...

  19. Advanced thermohydraulic simulation code for pool-type LMFBRs (SSC-P code)

    Energy Technology Data Exchange (ETDEWEB)

    Madni, I.K.; Cazzoli, E.G.

    1980-09-01

    Models for components and processes that are needed for simulation of thermohydraulic transient in a pool-type liquid metal fast breeder reactor (LMFBR) plant are described in this report. A computer code, SSC-P, has been developed as a part of the Super System Code (SSC) development project. A user's manual is being prepared as a separate document. 27 refs., 26 figs., 1 tab.

  20. Monte Carlo 2000 Conference : Advanced Monte Carlo for Radiation Physics, Particle Transport Simulation and Applications

    CERN Document Server

    Baräo, Fernando; Nakagawa, Masayuki; Távora, Luis; Vaz, Pedro

    2001-01-01

    This book focusses on the state of the art of Monte Carlo methods in radiation physics and particle transport simulation and applications, the latter involving in particular, the use and development of electron--gamma, neutron--gamma and hadronic codes. Besides the basic theory and the methods employed, special attention is paid to algorithm development for modeling, and the analysis of experiments and measurements in a variety of fields ranging from particle to medical physics.

  1. Simulation of emittance growth in the ALS [Advanced Light Source] pre-injector

    International Nuclear Information System (INIS)

    Transverse and longitudinal beam dynamics in the ALS preinjector were simulated with a 2 1/2 D code. Strong space charge-forces at low energy and nonlinearities caused emittances to grow. However, careful tuning of the bunching system and the linac reduced emittance growth to an acceptable label. About 1/3 of the gun output are within the required energy spread and the normalized rms emittance is significantly lower than the expected value. 3 refs., 7 figs., 1 tab

  2. Study of Plasma Liner Driven Magnetized Target Fusion Via Advanced Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Samulyak, Roman V. [State Univ. of New York (SUNY), Stony Brook, NY (United States); Brookhaven National Lab. (BNL), Upton, NY (United States); Parks, Paul [General Atomics, San Diego, CA (United States)

    2013-08-31

    The feasibility of the plasma liner driven Magnetized Target Fusion (MTF) via terascale numerical simulations will be assessed. In the MTF concept, a plasma liner, formed by merging of a number (60 or more) of radial, highly supersonic plasma jets, implodes on the target in the form of two compact plasma toroids, and compresses it to conditions of the fusion ignition. By avoiding major difficulties associated with both the traditional laser driven inertial confinement fusion and solid liner driven MTF, the plasma liner driven MTF potentially provides a low-cost and fast R&D path towards the demonstration of practical fusion energy. High fidelity numerical simulations of full nonlinear models associated with the plasma liner MTF using state-of-art numerical algorithms and terascale computing are necessary in order to resolve uncertainties and provide guidance for future experiments. At Stony Brook University, we have developed unique computational capabilities that ideally suite the MTF problem. The FronTier code, developed in collaboration with BNL and LANL under DOE funding including SciDAC for the simulation of 3D multi-material hydro and MHD flows, has beenbenchmarked and used for fundamental and engineering problems in energy science applications. We have performed 3D simulations of converging supersonic plasma jets, their merger and the formation of the plasma liner, and a study of the corresponding oblique shock problem. We have studied the implosion of the plasma liner on the magnetized plasma target by resolving Rayleigh-Taylor instabilities in 2D and 3D and other relevant physics and estimate thermodynamic conditions of the target at the moment of maximum compression and the hydrodynamic efficiency of the method.

  3. Simulating carbon exchange using a regional atmospheric model coupled to an advanced land-surface model

    Directory of Open Access Journals (Sweden)

    H. W. Ter Maat

    2010-08-01

    Full Text Available This paper is a case study to investigate what the main controlling factors are that determine atmospheric carbon dioxide content for a region in the centre of The Netherlands. We use the Regional Atmospheric Modelling System (RAMS, coupled with a land surface scheme simulating carbon, heat and momentum fluxes (SWAPS-C, and including also submodels for urban and marine fluxes, which in principle should include the dominant mechanisms and should be able to capture the relevant dynamics of the system. To validate the model, observations are used that were taken during an intensive observational campaign in central Netherlands in summer 2002. These include flux-tower observations and aircraft observations of vertical profiles and spatial fluxes of various variables.

    The simulations performed with the coupled regional model (RAMS-SWAPS-C are in good qualitative agreement with the observations. The station validation of the model demonstrates that the incoming shortwave radiation and surface fluxes of water and CO2 are well simulated. The comparison against aircraft data shows that the regional meteorology (i.e. wind, temperature is captured well by the model. Comparing spatially explicitly simulated fluxes with aircraft observed fluxes we conclude that in general latent heat fluxes are underestimated by the model compared to the observations but that the latter exhibit large variability within all flights. Sensitivity experiments demonstrate the relevance of the urban emissions of carbon dioxide for the carbon balance in this particular region. The same tests also show the relation between uncertainties in surface fluxes and those in atmospheric concentrations.

  4. Recent advances in computational methodology for simulation of mechanical circulatory assist devices

    OpenAIRE

    Marsden, Alison L.; Bazilevs, Yuri; Long, Christopher C.; Behr, Marek

    2014-01-01

    Ventricular assist devices (VADs) provide mechanical circulatory support to offload the work of one or both ventricles during heart failure. They are used in the clinical setting as destination therapy, as bridge to transplant, or more recently as bridge to recovery to allow for myocardial remodeling. Recent developments in computational simulation allow for detailed assessment of VAD hemodynamics for device design and optimization for both children and adults. Here, we provide a focused revi...

  5. Advances in Disaster Modeling, Simulation and Visualization for Sandstorm Risk Management in North China

    OpenAIRE

    Hang Lei; Zhaohui Lin; Jason K. Levy; Bell, Michelle L.

    2012-01-01

    Dust storms in North China result in high concentrations of airborne dust particles, which cause detrimental effects on human health as well as social and economic losses and environmental degradation. To investigate the impact of land surface processes on dust storms, we simulate two dust storm events in North China during spring 2002 using two versions of a dust storm prediction system developed by the Institute for Atmospheric Physics (IAP) in Beijing, China. The primary difference between...

  6. Numerical results for near surface time domain electromagnetic exploration: a full waveform approach

    Science.gov (United States)

    Sun, H.; Li, K.; Li, X., Sr.; Liu, Y., Sr.; Wen, J., Sr.

    2015-12-01

    Time domain or Transient electromagnetic (TEM) survey including types with airborne, semi-airborne and ground play important roles in applicants such as geological surveys, ground water/aquifer assess [Meju et al., 2000; Cox et al., 2010], metal ore exploration [Yang and Oldenburg, 2012], prediction of water bearing structures in tunnels [Xue et al., 2007; Sun et al., 2012], UXO exploration [Pasion et al., 2007; Gasperikova et al., 2009] etc. The common practice is introducing a current into a transmitting (Tx) loop and acquire the induced electromagnetic field after the current is cut off [Zhdanov and Keller, 1994]. The current waveforms are different depending on instruments. Rectangle is the most widely used excitation current source especially in ground TEM. Triangle and half sine are commonly used in airborne and semi-airborne TEM investigation. In most instruments, only the off time responses are acquired and used in later analysis and data inversion. Very few airborne instruments acquire the on time and off time responses together. Although these systems acquire the on time data, they usually do not use them in the interpretation.This abstract shows a novel full waveform time domain electromagnetic method and our recent modeling results. The benefits comes from our new algorithm in modeling full waveform time domain electromagnetic problems. We introduced the current density into the Maxwell's equation as the transmitting source. This approach allows arbitrary waveforms, such as triangle, half-sine, trapezoidal waves or scatter record from equipment, being used in modeling. Here, we simulate the establishing and induced diffusion process of the electromagnetic field in the earth. The traditional time domain electromagnetic with pure secondary fields can also be extracted from our modeling results. The real time responses excited by a loop source can be calculated using the algorithm. We analyze the full time gates responses of homogeneous half space and two

  7. Recent Advances in Computational Simulation of Macro-, Meso-, and Micro-Scale Biomimetics Related Fluid Flow Problems

    Institute of Scientific and Technical Information of China (English)

    Y. Y. Yan

    2007-01-01

    Over the last decade, computational methods have been intensively applied to a variety of scientific researches and engineering designs. Although the computational fluid dynamics (CFD) method has played a dominant role in studying and simulating transport phenomena involving fluid flow and heat and mass transfers, in recent years, other numerical methods for the simulations at meso- and micro-scales have also been actively applied to solve the physics of complex flow and fluid-interface interactions. This paper presents a review of recent advances in multi-scale computational simulation of biomimetics related fluid flow problems. The state-of-the-art numerical techniques, such as lattice Boltzmann method (LBM), molecular dynamics (MD), and conventional CFD, applied to different problems such as fish flow, electro-osmosis effect of earthworm motion, and self-cleaning hydrophobic surface, and the numerical approaches are introduced. The new challenging of modelling biomimetics problems in developing the physical conditions of self-clean hydrophobic surfaces is discussed.

  8. Simulation of nucleation and growth of atomic layer deposition phosphorus for doping of advanced FinFETs

    International Nuclear Information System (INIS)

    Simulations for the nucleation and growth of phosphorus films were carried out using density functional theory. The surface was represented by a Si9H12 truncated cluster surface model with 2 × 1-reconstructured (100) Si-OH terminations for the initial reaction sites. Chemistries included phosphorous halides (PF3, PCl3, and PBr3) and disilane (Si2H6). Atomic layer deposition (ALD) reaction sequences were illustrated with three-dimensional molecular models using sequential PF3 and Si2H6 reactions and featuring SiFH3 as a byproduct. Exothermic reaction pathways were developed for both nucleation and growth for a Si-OH surface. Energetically favorable reactions for the deposition of four phosphorus atoms including lateral P–P bonding were simulated. This paper suggests energetically favorable thermodynamic reactions for the growth of elemental phosphorus on (100) silicon. Phosphorus layers made by ALD are an option for doping advanced fin field-effect transistors (FinFETs). Phosphorus may be thermally diffused into the silicon or recoil knocked in; simulations of the recoil profile of phosphorus into a FinFET surface are illustrated

  9. Demonstration of structural performance of IP-2 packages by advanced analytical simulation and full-scale drop test

    International Nuclear Information System (INIS)

    Two new types of IP-2 (Industrial Package Type 2) to transport low and intermediate level radioactive waste (LILW) steel drums from nuclear power plants to a disposal facility have been developed in accordance with the IAEA and Korean regulations for radioactive materials. According to the regulations, both packages must preserve their structural performance after they are subjected to 0.9 m free drop tests, which are prescribed as normal conditions. In this study, an advanced analytical simulation and an evaluation process using the finite element (FE) method have been developed for the design assessment of the newly developed IP-2s. Then, analytical simulations for the various drop orientations were performed to evaluate the structural performance of the packages and demonstrate their compliance with the regulatory requirements. Also, full-scale drop tests were carried out to verify the numerical tools and modeling methodology used in the analyses and to confirm the performance of the IP-2s. In addition, parametric studies are carried out to investigate the sensitivity of the analytical variables, such as the material model and modeling methodology. In addition, this paper intends to provide basic guidance on the analytical simulation and evaluation process specifically for Korean types of transport packages, because numerous transport packages must now be developed for the various kinds of LILW that have accumulated in temporary storage facilities in Korea.

  10. Nuclear Energy Advanced Modeling and Simulation (NEAMS) Waste Integrated Performance and Safety Codes (IPSC) : FY10 development and integration.

    Energy Technology Data Exchange (ETDEWEB)

    Criscenti, Louise Jacqueline; Sassani, David Carl; Arguello, Jose Guadalupe, Jr.; Dewers, Thomas A.; Bouchard, Julie F.; Edwards, Harold Carter; Freeze, Geoffrey A.; Wang, Yifeng; Schultz, Peter Andrew

    2011-02-01

    This report describes the progress in fiscal year 2010 in developing the Waste Integrated Performance and Safety Codes (IPSC) in support of the U.S. Department of Energy (DOE) Office of Nuclear Energy Advanced Modeling and Simulation (NEAMS) Campaign. The goal of the Waste IPSC is to develop an integrated suite of computational modeling and simulation capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive waste storage or disposal system. The Waste IPSC will provide this simulation capability (1) for a range of disposal concepts, waste form types, engineered repository designs, and geologic settings, (2) for a range of time scales and distances, (3) with appropriate consideration of the inherent uncertainties, and (4) in accordance with robust verification, validation, and software quality requirements. Waste IPSC activities in fiscal year 2010 focused on specifying a challenge problem to demonstrate proof of concept, developing a verification and validation plan, and performing an initial gap analyses to identify candidate codes and tools to support the development and integration of the Waste IPSC. The current Waste IPSC strategy is to acquire and integrate the necessary Waste IPSC capabilities wherever feasible, and develop only those capabilities that cannot be acquired or suitably integrated, verified, or validated. This year-end progress report documents the FY10 status of acquisition, development, and integration of thermal-hydrologic-chemical-mechanical (THCM) code capabilities, frameworks, and enabling tools and infrastructure.

  11. Nuclear Energy Advanced Modeling and Simulation (NEAMS) Waste Integrated Performance and Safety Codes (IPSC): FY10 development and integration

    International Nuclear Information System (INIS)

    This report describes the progress in fiscal year 2010 in developing the Waste Integrated Performance and Safety Codes (IPSC) in support of the U.S. Department of Energy (DOE) Office of Nuclear Energy Advanced Modeling and Simulation (NEAMS) Campaign. The goal of the Waste IPSC is to develop an integrated suite of computational modeling and simulation capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive waste storage or disposal system. The Waste IPSC will provide this simulation capability (1) for a range of disposal concepts, waste form types, engineered repository designs, and geologic settings, (2) for a range of time scales and distances, (3) with appropriate consideration of the inherent uncertainties, and (4) in accordance with robust verification, validation, and software quality requirements. Waste IPSC activities in fiscal year 2010 focused on specifying a challenge problem to demonstrate proof of concept, developing a verification and validation plan, and performing an initial gap analyses to identify candidate codes and tools to support the development and integration of the Waste IPSC. The current Waste IPSC strategy is to acquire and integrate the necessary Waste IPSC capabilities wherever feasible, and develop only those capabilities that cannot be acquired or suitably integrated, verified, or validated. This year-end progress report documents the FY10 status of acquisition, development, and integration of thermal-hydrologic-chemical-mechanical (THCM) code capabilities, frameworks, and enabling tools and infrastructure.

  12. Simulation of nucleation and growth of atomic layer deposition phosphorus for doping of advanced FinFETs

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, Thomas E., E-mail: zoomtotom@gmail.com [Seitek50, Palm Coast, Florida 32135 (United States); Goldberg, Alexander; Halls, Mat D. [Schrödinger, Inc., San Diego, California 92122 (United States); Current, Michael I. [Current Scientific, San Jose, California 95124 (United States)

    2016-01-15

    Simulations for the nucleation and growth of phosphorus films were carried out using density functional theory. The surface was represented by a Si{sub 9}H{sub 12} truncated cluster surface model with 2 × 1-reconstructured (100) Si-OH terminations for the initial reaction sites. Chemistries included phosphorous halides (PF{sub 3}, PCl{sub 3}, and PBr{sub 3}) and disilane (Si{sub 2}H{sub 6}). Atomic layer deposition (ALD) reaction sequences were illustrated with three-dimensional molecular models using sequential PF{sub 3} and Si{sub 2}H{sub 6} reactions and featuring SiFH{sub 3} as a byproduct. Exothermic reaction pathways were developed for both nucleation and growth for a Si-OH surface. Energetically favorable reactions for the deposition of four phosphorus atoms including lateral P–P bonding were simulated. This paper suggests energetically favorable thermodynamic reactions for the growth of elemental phosphorus on (100) silicon. Phosphorus layers made by ALD are an option for doping advanced fin field-effect transistors (FinFETs). Phosphorus may be thermally diffused into the silicon or recoil knocked in; simulations of the recoil profile of phosphorus into a FinFET surface are illustrated.

  13. Generation of correlated finite alphabet waveforms using gaussian random variables

    KAUST Repository

    Ahmed, Sajid

    2016-01-13

    Various examples of methods and systems are provided for generation of correlated finite alphabet waveforms using Gaussian random variables in, e.g., radar and communication applications. In one example, a method includes mapping an input signal comprising Gaussian random variables (RVs) onto finite-alphabet non-constant-envelope (FANCE) symbols using a predetermined mapping function, and transmitting FANCE waveforms through a uniform linear array of antenna elements to obtain a corresponding beampattern. The FANCE waveforms can be based upon the mapping of the Gaussian RVs onto the FANCE symbols. In another example, a system includes a memory unit that can store a plurality of digital bit streams corresponding to FANCE symbols and a front end unit that can transmit FANCE waveforms through a uniform linear array of antenna elements to obtain a corresponding beampattern. The system can include a processing unit that can encode the input signal and/or determine the mapping function.

  14. Simulation of concomitant magnetic fields on fast switched gradient coils used in advanced application of MRI

    Science.gov (United States)

    Salinas-Muciño, G.; Torres-García, E.; Hidalgo-Tobon, S.

    2012-10-01

    The process to produce an MR image includes nuclear alignment, RF excitation, spatial encoding, and image formation. To form an image, it is necessary to perform spatial localization of the MR signals, which is achieved using gradient coils. MRI requires the use of gradient coils that generate magnetic fields, which vary linearly with position over the imaging volume. Safety issues have been a motivation to study deeply the relation between the interaction of gradient magnetic field and the peripheral nerve stimulation. In this work is presented a numerical modeling between the concomitant magnetic fields produced by the gradient coils and the electric field induced in a cube with σ conductivity by the gradient field switching in pulse sequences as Eco planar Imaging (EPI), due to this kind of sequence is the most used in advance applications of magnetic resonance imaging as functional MRI, cardiac imaging or diffusion.

  15. A Simulation Study Comparing Incineration and Composting in a Mars-Based Advanced Life Support System

    Science.gov (United States)

    Hogan, John; Kang, Sukwon; Cavazzoni, Jim; Levri, Julie; Finn, Cory; Luna, Bernadette (Technical Monitor)

    2000-01-01

    The objective of this study is to compare incineration and composting in a Mars-based advanced life support (ALS) system. The variables explored include waste pre-processing requirements, reactor sizing and buffer capacities. The study incorporates detailed mathematical models of biomass production and waste processing into an existing dynamic ALS system model. The ALS system and incineration models (written in MATLAB/SIMULINK(c)) were developed at the NASA Ames Research Center. The composting process is modeled using first order kinetics, with different degradation rates for individual waste components (carbohydrates, proteins, fats, cellulose and lignin). The biomass waste streams are generated using modified "Eneray Cascade" crop models, which use light- and dark-cycle temperatures, irradiance, photoperiod, [CO2], planting density, and relative humidity as model inputs. The study also includes an evaluation of equivalent system mass (ESM).

  16. Advances in Intelligent Modelling and Simulation Artificial Intelligence-Based Models and Techniques in Scalable Computing

    CERN Document Server

    Khan, Samee; Burczy´nski, Tadeusz

    2012-01-01

    One of the most challenging issues in today’s large-scale computational modeling and design is to effectively manage the complex distributed environments, such as computational clouds, grids, ad hoc, and P2P networks operating under  various  types of users with evolving relationships fraught with  uncertainties. In this context, the IT resources and services usually belong to different owners (institutions, enterprises, or individuals) and are managed by different administrators. Moreover, uncertainties are presented to the system at hand in various forms of information that are incomplete, imprecise, fragmentary, or overloading, which hinders in the full and precise resolve of the evaluation criteria, subsequencing and selection, and the assignment scores. Intelligent scalable systems enable the flexible routing and charging, advanced user interactions and the aggregation and sharing of geographically-distributed resources in modern large-scale systems.   This book presents new ideas, theories, models...

  17. NATO Advanced Study Institute on Microscopic Simulations of Complex Hydrodynamic Phenomena

    CERN Document Server

    Holian, Brad

    1992-01-01

    This volume contains the proceedings of a NATO Advanced Study Institute which was held in Alghero, Sardinia, in July 1991. The development of computers in the recent years has lead to the emergence of unconventional ideas aiming at solving old problems. Among these, the possibility of computing directly fluid flows from the trajectories of constituent particles has been much exploited in the last few years: lattice gases cellular automata and more generally Molecular Dynamics have been used to reproduce and study complex flows. Whether or not these methods may someday compete with more traditional approaches is a question which cannot be answered at the present time: it will depend on the new computer architectures as well as on the possibility to develop very simple models to reproduce the most complex phenomena taking place in the approach of fully developed turbulence or plastic flows. In any event, these molecular methods are already used, and sometimes in an applied engineering context, to study strong s...

  18. Full waveform inversion of solar interior flows

    International Nuclear Information System (INIS)

    The inference of flows of material in the interior of the Sun is a subject of major interest in helioseismology. Here, we apply techniques of full waveform inversion (FWI) to synthetic data to test flow inversions. In this idealized setup, we do not model seismic realization noise, training the focus entirely on the problem of whether a chosen supergranulation flow model can be seismically recovered. We define the misfit functional as a sum of L 2 norm deviations in travel times between prediction and observation, as measured using short-distance filtered f and p 1 and large-distance unfiltered p modes. FWI allows for the introduction of measurements of choice and iteratively improving the background model, while monitoring the evolution of the misfit in all desired categories. Although the misfit is seen to uniformly reduce in all categories, convergence to the true model is very slow, possibly because it is trapped in a local minimum. The primary source of error is inaccurate depth localization, which, due to density stratification, leads to wrong ratios of horizontal and vertical flow velocities (cross talk). In the present formulation, the lack of sufficient temporal frequency and spatial resolution makes it difficult to accurately localize flow profiles at depth. We therefore suggest that the most efficient way to discover the global minimum is to perform a probabilistic forward search, involving calculating the misfit associated with a broad range of models (generated, for instance, by a Monte Carlo algorithm) and locating the deepest minimum. Such techniques possess the added advantage of being able to quantify model uncertainty as well as realization noise (data uncertainty).

  19. Understanding the impact of recent advances in isoprene photooxidation on simulations of regional air quality

    Directory of Open Access Journals (Sweden)

    Y. Xie

    2013-08-01

    Full Text Available The CMAQ (Community Multiscale Air Quality us model in combination with observations for INTEX-NA/ICARTT (Intercontinental Chemical Transport Experiment–North America/International Consortium for Atmospheric Research on Transport and Transformation 2004 are used to evaluate recent advances in isoprene oxidation chemistry and provide constraints on isoprene nitrate yields, isoprene nitrate lifetimes, and NOx recycling rates. We incorporate recent advances in isoprene oxidation chemistry into the SAPRC-07 chemical mechanism within the US EPA (United States Environmental Protection Agency CMAQ model. The results show improved model performance for a range of species compared against aircraft observations from the INTEX-NA/ICARTT 2004 field campaign. We further investigate the key processes in isoprene nitrate chemistry and evaluate the impact of uncertainties in the isoprene nitrate yield, NOx (NOx = NO + NO2 recycling efficiency, dry deposition velocity, and RO2 + HO2 reaction rates. We focus our examination on the southeastern United States, which is impacted by both abundant isoprene emissions and high levels of anthropogenic pollutants. We find that NOx concentrations increase by 4–9% as a result of reduced removal by isoprene nitrate chemistry. O3 increases by 2 ppbv as a result of changes in NOx. OH concentrations increase by 30%, which can be primarily attributed to greater HOx production. We find that the model can capture observed total alkyl and multifunctional nitrates (∑ANs and their relationship with O3 by assuming either an isoprene nitrate yield of 6% and daytime lifetime of 6 hours or a yield of 12% and lifetime of 4 h. Uncertainties in the isoprene nitrates can impact ozone production by 10% and OH concentrations by 6%. The uncertainties in NOx recycling efficiency appear to have larger effects than uncertainties in isoprene nitrate yield and dry deposition velocity. Further progress depends on improved understanding of

  20. Binary Black Hole Waveform Extraction at Null Infinity

    CERN Document Server

    Babiuc, M C; Zlochower, Y

    2011-01-01

    In this work, we present a work in progress towards an efficient and economical computational module which interfaces between Cauchy and characteristic evolution codes. Our goal is to provide a standardized waveform extraction tool for the numerical relativity community which will allow CCE to be readily applied to a generic Cauchy code. The tool provides a means of unambiguous comparison between the waveforms generated by evolution codes based upon different formulations of the Einstein equations and different numerical approximation.