WorldWideScience

Sample records for learning trough structured

  1. Solar photovoltaic reflective trough collection structure

    Science.gov (United States)

    Anderson, Benjamin J.; Sweatt, William C.; Okandan, Murat; Nielson, Gregory N.

    2015-11-19

    A photovoltaic (PV) solar concentration structure having at least two troughs encapsulated in a rectangular parallelepiped optical plastic structure, with the troughs filled with an optical plastic material, the troughs each having a reflective internal surface and approximately parabolic geometry, and the troughs each including photovoltaic cells situated so that light impinging on the optical plastic material will be concentrated onto the photovoltaic cells. Multiple structures can be connected to provide a solar photovoltaic collection system that provides portable, efficient, low-cost electrical power.

  2. The crustal structure along the Mbere trough in South Adamawa ...

    African Journals Online (AJOL)

    The Mbere Cretaceous trough is located in the southern part of the Adamawa province. A gravity interpretation based on data obtained from three NW-SE profiles on the residual anomaly map has been carried out using a 2.5D modelling program. Spectral analysis has been used to estimate the depth of geological ...

  3. Structural control of the Gagua "Wedge" Zone east of Taiwan Island on the southern Okinawa Trough

    Institute of Scientific and Technical Information of China (English)

    ZHENG; Yanpeng; LIU; Baohua; WU; Jinlong; LIANG; Ruicai; L

    2005-01-01

    Based on compositive analysis and interpretation of the observed and historical data, the geophysical field characters and structural properties of the Gagua "Wedge" Zone of the sea area east of Taiwan Island and the primary tectonic stress direction and its variabilities of backarc spreading in the southern Okinawa Trough are studied. It is concluded from the study results that the Gagua "Wedge" Zone is structurally consistent with the Gagua ridge and two fault basins on both sides of the Gagua ridge, and adjusts the moving direction and distance of the western Philippine Sea plate to make the northwestward motion of the plate on its east side change to the northward subduction of the plate on its west side so that the primary tectonic stress direction of the Okinawa Trough changed from NW-SE to nearly N-S, which provided the stress source for the Okinawa Trough to enter the second spreading stage.

  4. Basinal Structure Of Yola Arm Of The Upper Benue Trough Nigeria ...

    African Journals Online (AJOL)

    Aeromagnetic data interpretation of the Yola arm of the Upper Benue Trough has previously been carried out. However, no detail modeling of the Crustal Structures has been undertaken. Two composite reduced Aeromagnetic maps on a scale of 1:250,000 were digitized and processed using computer techniques.

  5. Characterizing structures on borehole images and logging data of the Nankai trough accretionary prism: new insights

    Science.gov (United States)

    Jurado, Maria Jose

    2016-04-01

    IODP has extensively used the D/V Chikyu to drill the Kumano portion of the Nankai Trough, including two well sites within the Kumano Basin. IODP Expeditions 338 and 348 drilled deep into the inner accretionary prism south of the Kii Peninsula collecting a suite of LWD data, including natural gamma ray, electrical resistivity logs and borehole images, suitable to characterize structures (fractures and faults) inside the accretionary prism. Structural interpretation and analysis of logging-while-drilling data in the deep inner prism revealed intense deformation of a generally homogenous lithology characterized by bedding that dips steeply (60-90°) to the NW, intersected by faults and fractures. Multiple phases of deformation are characterized. IODP Expedition borehole images and LWD data acquired in the last decade in previous and results of NantroSEIZE IODP Expeditions (314, 319) were also analyzed to investigate the internal geometries and structures of the Nankai Trough accretionary prism. This study focused mainly on the characterization of the different types of structures and their specific position within the accretionary prism structures. New structural constraints and methodologies as well as a new approach to the characterization of study of active structures inside the prism will be presented.

  6. The Neo-Tectonic Structure of the South western Tip of the Okinawa Trough

    Directory of Open Access Journals (Sweden)

    Chia-Yen Ku

    2009-01-01

    Full Text Available The Ilan Plain is located at the south western tip of the Okinawa Trough backarc basin, which prop a gates west ward into the Taiwan orogen. From three moderate earthquakes which occurred near the coast line of the Ilan Plain, one of magnitude 6.2 on 15 May 2002 and the other two of magnitudes 5.51 and 5.49 on 5 March 2005, we at tempted to understand the relation ship between the earthquake mechanisms and the geological context. Seven seismic reflection pro files collected roughly parallel to the coast line of the Ilan Plain were used in this work. A structural fault, with a significant normal faulting component trending approximately ENE-WSW, is identified to the east of the doublet earth quakes of 5 March 2005. Be cause this fault follows the ENE-WSW trend of the after shock seismicity, we named it the Ilan Shelf Fault, which might ex tend to the east be yond the Ilan continental shelf spur. How ever, the centroid seismic moment ten sorsolutions for the doublet earth quakes of 5 March 2005 are of a left-lateral strike-slip faulting type which are consistent with onland GPS observations. Hence, the Ilan Shelf Fault may have a left-lateral strike-slip component. Based on GPS data, we suggest that the northern Central Range block, bounded in the west by the Lishan Fault and in the north by the Ilan Shelf Fault, rotates clock wise. This rotation is ascribed to the northwestward collision of the Luzon Arc against Tai wan. Thus, there is a left-lateral strike-slip and an extensional motion along the Ilan Shelf Fault. The northern Central Range block is tilting north ward which may also in duce the normal faulting component of the Ilan Shelf Fault. In short, the Ilan Shelf Fault could be a major tectonic and structural feature bounding the southern end of the Okinawa Trough backarc basin.

  7. Self regulated learning trough project base learning on the prospective math teacher

    Science.gov (United States)

    Laelasari

    2018-03-01

    Development of planning, strategy, and learning activities is strongly influenced by metacognition ability, knowledge of learning strategy, and understanding of context is the most important thing to be mastered by a prospective teacher. Self-regulation owned by the individual can control behavior, and manipulate a behavior by using the ability of his mind so that individuals can react to their environment. Self-regulation is the basis of the socialization process as it relates to the entire domain of physical, cognitive, social, and emotional development. This research is a qualitative research with research subject of the fourth-semester student of class A, at one of a university in Cirebon City, West Java. In this research, the lecture material discussed is The Development of Teaching Materials, which is the subject matter that must be mastered by prospective teachers, especially teachers of mathematics education. The instrument used is the questionnaire. The results showed that through project based learning, can grow student’s self-regulated learning especially the prospective math teacher, and can be used as an alternative to the delivery of lecture materials.

  8. Heat Flow Variation along the Nankai Trough Floor Correlated with the Structure of the Shikoku Basin Oceanic Crust

    Science.gov (United States)

    Yamano, M.; Kawada, Y.; Gao, X.

    2016-12-01

    Surface heat flow observed on the floor of the Nankai Trough, near the trench axis, is highly variable and does not well correspond to the seafloor age of the incoming Philippine Sea plate (Shikoku Basin). Recent detailed measurements between 133.5°E and 137°E revealed that heat flow on the trough floor significantly varies along the trough. The most conspicuous variation is found around 136°E. Heat flow is extremely high and variable between 135°E and 136°E, much higher than the value estimated from the age. On the east of 136°E, heat flow gradually decreases eastward over 50 km to the value nearly consistent with the age with no appreciable scatter. Elevated heat flow on the trough floor can be attributed to vigorous fluid circulation in a permeable layer (aquifer) in the subducted oceanic crust, which efficiently transports heat upward along the plate interface (Spinelli and Wang, 2008). The heat flow variation around 136°E may therefore arise from variation in the permeability structure of the crustal aquifer. A probable cause of the heterogeneity in the aquifer permeability is a structure boundary in the incoming Shikoku Basin, the boundary between the younger part on the west formed by spreading in NE-SW direction and the older part on the east formed by E-W spreading. It is located around 136°E, about the same place as the heat flow distribution boundary. A possible additional source of variation in the permeability structure is the geometry of the subducted Philippine Sea plate. A prominent bend in the subducted plate between 135°E and 136°E, which corresponds to the high heat flow area on the trough floor, may have fractured the oceanic crust and enhanced the aquifer permeability. We evaluated the influence of variations in the aquifer permeability on the thermal structure through 3D numerical modelling using a high thermal-conductivity proxy for heat transport by fluid flow. A sharp along-strike change in the permeability of the subducted

  9. Crustal and upper mantle velocity structure of the Salton Trough, southeast California

    Science.gov (United States)

    Parsons, T.; McCarthy, J.

    1996-01-01

    This paper presents data and modelling results from a crustal and upper mantle wide-angle seismic transect across the Salton Trough region in southeast California. The Salton Trough is a unique part of the Basin and Range province where mid-ocean ridge/transform spreading in the Gulf of California has evolved northward into the continent. In 1992, the U.S. Geological Survey (USGS) conducted the final leg of the Pacific to Arizona Crustal Experiment (PACE). Two perpendicular models of the crust and upper mantle were fit to wide-angle reflection and refraction travel times, seismic amplitudes, and Bouguer gravity anomalies. The first profile crossed the Salton Trough from the southwest to the northeast, and the second was a strike line that paralleled the Salton Sea along its western edge. We found thin crust (???21-22 km thick) beneath the axis of the Salton Trough (Imperial Valley) and locally thicker crust (???27 km) beneath the Chocolate Mountains to the northeast. We modelled a slight thinning of the crust further to the northeast beneath the Colorado River (???24 km) and subsequent thickening beneath the metamorphic core complex belt northeast of the Colorado River. There is a deep, apparently young basin (???5-6 km unmetamorphosed sediments) beneath the Imperial Valley and a shallower (???2-3 km) basin beneath the Colorado River. A regional 6.9-km/s layer (between ???15-km depth and the Moho) underlies the Salton Trough as well as the Chocolate Mountains where it pinches out at the Moho. This lower crustal layer is spatially associated with a low-velocity (7.6-7.7 km/s) upper mantle. We found that our crustal model is locally compatible with the previously suggested notion that the crust of the Salton Trough has formed almost entirely from magmatism in the lower crust and sedimentation in the upper crust. However, we observe an apparently magmatically emplaced lower crust to the northeast, outside of the Salton Trough, and propose that this layer in part

  10. Structural characteristics around the frontal thrust along the Nankai Trough revealed by bathymetric and seismic reflection survey

    Science.gov (United States)

    Yamashita, M.; Nakanishi, A.; Moore, G. F.; Kodaira, S.; Nakamura, Y.; Miura, S.; Kaneda, Y.

    2016-12-01

    Great earthquakes with tsunamis with recurrence intervals of 100-200 years have occurred along the Nankai Trough near central Japan where the Shikoku Basin is subducting with thick sediments on the Philippine Sea plate. To predict the exact height of the tsunami on the coast region generated by these large ruptures, it is important to estimate the vertical deformation that occurs on the seaward end of the rupture area. Recent drilling results have also yielded evidence not only of splay faults that generate tsunamigenic rupture, but also new evidence of tsunamigenic rupture along the frontal thrust at the trench axis in the Nankai Trough. In order to understand the deformation around the frontal thrust at the trench axis, we conducted a dense high-resolution seismic reflection survey with 10-20 km spacing over 1500 km of line length during 2013 and 2014. Clear seismic reflection images of frontal thrusts in the accretionary prism and subducting Shikoku Basin, image deformation along the trench axis between off Muroto Cape and off Ashizuri Cape. The cumulative displacement along the frontal thrust and second thrust are measured from picked distinct reflectors in depth-converted profiles. The average value of cumulative displacement of the frontal thrust is more than 100 m within 2 km depth beneath the seafloor. The location of highest displacement of 300 m displacement agree with the seaward end of slip distribution of the 1946 Nankai event calculated by numerical simulations. We also evaluate the seaward structure for understanding the future rupture distribution. The protothrust zone (PTZ) consisting of many incipient thrusts is identifiable in the portion of trough-fill sediments seaward of the frontal thrust. In order to emphasize the characteristics of frontal thrust and PTZ, we construct the detailed relief image for focusing on the lineated slope of the PTZ at the trough axis. Although our surveys covered a part of Nankai seismogenic zone, it is important to

  11. Shallow Crustal Structure in the Northern Salton Trough, California: Insights from a Detailed 3-D Velocity Model

    Science.gov (United States)

    Ajala, R.; Persaud, P.; Stock, J. M.; Fuis, G. S.; Hole, J. A.; Goldman, M.; Scheirer, D. S.

    2017-12-01

    The Coachella Valley is the northern extent of the Gulf of California-Salton Trough. It contains the southernmost segment of the San Andreas Fault (SAF) for which a magnitude 7.8 earthquake rupture was modeled to help produce earthquake planning scenarios. However, discrepancies in ground motion and travel-time estimates from the current Southern California Earthquake Center (SCEC) velocity model of the Salton Trough highlight inaccuracies in its shallow velocity structure. An improved 3-D velocity model that better defines the shallow basin structure and enables the more accurate location of earthquakes and identification of faults is therefore essential for seismic hazard studies in this area. We used recordings of 126 explosive shots from the 2011 Salton Seismic Imaging Project (SSIP) to SSIP receivers and Southern California Seismic Network (SCSN) stations. A set of 48,105 P-wave travel time picks constituted the highest-quality input to a 3-D tomographic velocity inversion. To improve the ray coverage, we added network-determined first arrivals at SCSN stations from 39,998 recently relocated local earthquakes, selected to a maximum focal depth of 10 km, to develop a detailed 3-D P-wave velocity model for the Coachella Valley with 1-km grid spacing. Our velocity model shows good resolution ( 50 rays/cubic km) down to a minimum depth of 7 km. Depth slices from the velocity model reveal several interesting features. At shallow depths ( 3 km), we observe an elongated trough of low velocity, attributed to sediments, located subparallel to and a few km SW of the SAF, and a general velocity structure that mimics the surface geology of the area. The persistence of the low-velocity sediments to 5-km depth just north of the Salton Sea suggests that the underlying basement surface, shallower to the NW, dips SE, consistent with interpretation from gravity studies (Langenheim et al., 2005). On the western side of the Coachella Valley, we detect depth-restricted regions of

  12. Interaction of Structure and Physical Properties in Accretionary Wedges: Examples from the Cascadia and Nankai Trough Subduction Zones

    Science.gov (United States)

    Webb, Susanna I.

    Subduction zones are capable of producing large, megathrust earthquakes that are sometimes tsunamigenic. Structure and physical properties in the accretionary wedge play a role in how far rupture can propagate and how the wedge deforms coseismically. In this dissertation, I use seismic reflection data and velocity models from the Cascadia subduction zone and logging data from the Nankai Trough, Japan, to interpret structure, link structure to the broader wedge deformation history, and investigate the material properties at depth. I present a full structural interpretation of newly acquired seismic reflection data in the central Cascadia margin, which is characterized by dominantly landward vergent faulting in the outer wedge, a very low wedge taper angle, and a broad, lightly deformed lower slope terrace. Two decollements are active: an upper decollement within the sedimentary section, and a basal decollement at the sediment-basement interface. These interpretations help delineate the spatial extent of decollements and suggest that supra-wedge sedimentation may influence the development of the wedge, including the formation of the lower slope terrace and out of sequence fault activity. I use velocity models from central Cascadia to estimate excess pore fluid pressure and overpressure ratio at depth, which do not exceed 5 MPa and 0.15, respectively. No excess pore pressure is documented in the underthrust sediment section, but modest overpressure is likely present in the incoming sediment section and the footwalls of thrust sheets. The analysis of pore pressure shows that (1) if the base of the wedge is weak, it is due to mechanical properties of the sediments or a relatively thin underthrust layer and (2) the Cascadia wedge is relatively well-drained, and thus potentially strong, which can lead to a low wedge taper angle. In the Nankai Trough, Japan, I reprocessed sonic log data to obtain P-wave and S-wave velocity values and estimate elastic moduli. The logs

  13. Trough for piglets

    DEFF Research Database (Denmark)

    2006-01-01

    A trough is disclosed for supplying piglets with mineral supplements in the suckling period. The trough is designed to awaken the piglets' curiosity and thus make them root in the bottom of the trough, where the mineral supplements are dispensed in form of a dry powder mixture, and thus reduce...

  14. A New Look at the Bathymetric and Potential-Field Structure of the Cayman Trough via CaySEIS

    Science.gov (United States)

    Hayman, N. W.; Harding, J.; Van Avendonk, H. J.; Peirce, C.; Grevemeyer, I.; Dannowski, A.; Papenberg, C. A.

    2015-12-01

    The Cayman Trough (CT) has one of the world's deepest axial valleys, thinnest crust, end-member basalt composition, and slowest spreading rate. Accommodating motion between the North American and Caribbean plates, and the Gonave microplate, marine magnetic anomalies show that the Mid-Cayman Spreading Center (MCSC) has been spreading at ~15 mm/yr (F.R.) since 20 Ma, if not 49 Ma. At a little over 100 km in length, the MCSC is now recognized to host oceanic core complexes (OCCs), hydrothermal vents, and a seafloor of variably distributed lower crustal gabbros, upper mantle peridotite/serpentinite, and basaltic lavas. Though spreading rate appears to be relatively symmetric over geologic time, the structure of the CT is quite asymmetric, with a broad region of low gravity and somewhat lineated magnetic anomalies to the east, and gravity highs and irregular magnetic anomalies to the west. Until now it has been difficult to further assess the nature of the CT because of the sparse and generally old data from the region; the CT's claim on thinnest crust, for example, stems primarily from pre-1960's seismic data and inferences from satellite gravity. The CaySEIS active-source OBS-experiment on the R/V Meteor thus set out in April of 2015 to provide a more complete, deeper view of the CT. A serendipitous discovery during the expedition is that the off-axis seafloor is characterized by curvilinear ridges preserving what appear to be dismembered OCCs. Thus, a previously proposed model based on the oblique volcanic ridge to the south of the axial OCC, Mt. Dent, could also apply to the geologic history of the CT. This model, which we call "the magmatic cleaver", envisions how intrusions cut the OCC surfaces and raft the hanging-wall-dominated portion of the OCC to the east, and the footwall-dominated portion to the west. The "cleaver" appears to have been operating over at least the last 20 Ma, illustrating how melt flow in ultraslow-spread crust can create distinctive

  15. Analysis of fine ELF wave structures observed poleward from the ionospheric trough by the low-altitude satellite DEMETER

    Czech Academy of Sciences Publication Activity Database

    Parrot, M.; Nĕmec, F.; Santolík, Ondřej

    2014-01-01

    Roč. 119, č. 3 (2014), s. 2052-2060 ISSN 2169-9380 R&D Projects: GA ČR GAP205/10/2279; GA MŠk LH12231 Institutional support: RVO:68378289 Keywords : trough * EMIC * substorm Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.426, year: 2014 http://onlinelibrary.wiley.com/doi/10.1002/2013JA019557/abstract

  16. 241-AZ-101 pump removal trough analysis

    International Nuclear Information System (INIS)

    Coverdell, B.L.

    1995-01-01

    As part of the current Hanford mission of environmental cleanup, various long length equipment must be removed from highly radioactive waste tanks. The removal of equipment will utilize portions of the Equipment Removal System for Project W320 (ERS-W320), specifically the 50 ton hydraulic trailer system. Because the ERS-W320 system was designed to accommodate much heavier equipment it is adequate to support the dead weight of the trough, carriage and related equipment for 241AZ101 pump removal project. However, the ERS-W320 components when combined with the trough and its' related components must also be analyzed for overturning due to wind loads. Two troughs were designed, one for the 20 in. diameter carriage and one for the 36 in. diameter carriage. A proposed 52 in. trough was not designed and, therefore is not included in this document. In order to fit in the ERS-W320 strongback the troughs were design with the same widths. Structurally, the only difference between the two troughs is that more material was removed from the stiffener plates on the 36 in trough. The reduction in stiffener plate material reduces the allowable load. Therefore, only the 36 in. trough was analyzed

  17. Three-dimensional model of plate geometry and velocity model for Nankai Trough seismogenic zone based on results from structural studies

    Science.gov (United States)

    Nakanishi, A.; Shimomura, N.; Kodaira, S.; Obana, K.; Takahashi, T.; Yamamoto, Y.; Yamashita, M.; Takahashi, N.; Kaneda, Y.

    2012-12-01

    In the Nankai Trough subduction seismogenic zone, the Nankai and Tonankai earthquakes had often occurred simultaneously, and caused a great event. In order to reduce a great deal of damage to coastal area from both strong ground motion and tsunami generation, it is necessary to understand rupture synchronization and segmentation of the Nankai megathrust earthquake. For a precise estimate of the rupture zone of the Nankai megathrust event based on the knowledge of realistic earthquake cycle and variation of magnitude, it is important to know the geometry and property of the plate boundary of the subduction seismogenic zone. To improve a physical model of the Nankai Trough seismogenic zone, the large-scale high-resolution wide-angle and reflection (MCS) seismic study, and long-term observation has been conducted since 2008. Marine active source seismic data have been acquired along grid two-dimensional profiles having the total length of ~800km every year. A three-dimensional seismic tomography using active and passive seismic data observed both land and ocean bottom stations have been also performed. From those data, we found that several strong lateral variations of the subducting Philippine Sea plate and overriding plate corresponding to margins of coseismic rupture zone of historical large event occurred along the Nankai Trough. Particularly a possible prominent reflector for the forearc Moho is recently imaged in the offshore side in the Kii channel at the depth of ~18km which is shallower than those of other area along the Nankai Trough. Such a drastic variation of the overriding plate might be related to the existence of the segmentation of the Nankai megathrust earthquake. Based on our results derived from seismic studies, we have tried to make a geometrical model of the Philippine Sea plate and a three-dimensional velocity structure model of the Nankai Trough seismogenic zone. In this presentation, we will summarize major results of out seismic studies, and

  18. Structure of the surface of the Paleozoic basement of the cis-Kopetdag trough in connection with the oil and gas content of the sedimentary cover

    Energy Technology Data Exchange (ETDEWEB)

    Odekov, O.A.; Mel' nik, N.M.; Tulaeva, S.V.

    1981-01-01

    Use of a complex of different methods permitted a new approach to the study of the nature of the surface of the Paleozoic basement. As a result of constructing models of the deep structure of the cis-Kopetdag trough and the Bakhardok monocline a new map of the major tectonic elements of the region has been developed and a map of the surface structure of the Paleozoic basement and a map of the Moho discontinuity have been compiled. The former gives a major new solution to many problems of the dep structure of the region: 1) in the zone of juncture of the cis-Kopetdag trough and the Bakhardok monocline a new positive structural element has been identified, called the Bakhardok-Kumbet buried superarch; 2) a completely new morphology of the western part of the Serakh connector has been given, within which two independent buried arches are identified, the Shatlyk and Tedzhenskii; 3) it has been established that the Izgantskii arch of the sedimentary cover corresponds to the Izgant uplifted block of the basement. These structural elements are described, methods for identifying them are outlined, and some principles of the variatin of the parameters of the geophysical fields are described. The prospects for the juncture zone are estimated as fairly high from the viewpoint of discovering different types of oil and gas deposits in the widest stratigraphic interval, from the Lower Jurassic to the Neokomian.

  19. First Comparative Analysis of the Community Structures and Carbon Metabolic Pathways of the Bacteria Associated with Alvinocaris longirostris in a Hydrothermal Vent of Okinawa Trough.

    Science.gov (United States)

    Sun, Qing-Lei; Zeng, Zhi-Gang; Chen, Shuai; Sun, Li

    2016-01-01

    Alvinocaris longirostris is a species of shrimp existing in the hydrothermal fields of Okinawa Trough. To date the structure and function of the microbial community associated with A. longirostris are essentially unknown. In this study, by employment of the techniques of high through-put sequencing and clone library construction and analysis, we compared for the first time the community structures and metabolic profiles of microbes associated with the gill and gut of A. longirostris in a hydrothermal field of Okinawa Trough. Fourteen phyla were detected in the gill and gut communities, of which 11 phyla were shared by both tissues. Proteobacteria made up a substantial proportion in both tissues, while Firmicutes was abundant only in gut. Although gill and gut communities were similar in bacterial diversities, the bacterial community structures in these two tissues were significantly different. Further, we discovered for the first time the existence in the gill and gut communities of A. longirostris the genes (cbbM and aclB) encoding the key enzymes of Calvin-Benson-Bassham (CBB) cycle and the reductive tricarboxylic acid (rTCA) cycle, and that both cbbM and aclB were significantly more abundant in gill than in gut. Taken together, these results provide the first evidence that at least two carbon fixation pathways are present in both the gill and the gut communities of A. longirostris, and that the communities in different tissues likely differ in autotrophic productivity.

  20. First Comparative Analysis of the Community Structures and Carbon Metabolic Pathways of the Bacteria Associated with Alvinocaris longirostris in a Hydrothermal Vent of Okinawa Trough.

    Directory of Open Access Journals (Sweden)

    Qing-Lei Sun

    Full Text Available Alvinocaris longirostris is a species of shrimp existing in the hydrothermal fields of Okinawa Trough. To date the structure and function of the microbial community associated with A. longirostris are essentially unknown. In this study, by employment of the techniques of high through-put sequencing and clone library construction and analysis, we compared for the first time the community structures and metabolic profiles of microbes associated with the gill and gut of A. longirostris in a hydrothermal field of Okinawa Trough. Fourteen phyla were detected in the gill and gut communities, of which 11 phyla were shared by both tissues. Proteobacteria made up a substantial proportion in both tissues, while Firmicutes was abundant only in gut. Although gill and gut communities were similar in bacterial diversities, the bacterial community structures in these two tissues were significantly different. Further, we discovered for the first time the existence in the gill and gut communities of A. longirostris the genes (cbbM and aclB encoding the key enzymes of Calvin-Benson-Bassham (CBB cycle and the reductive tricarboxylic acid (rTCA cycle, and that both cbbM and aclB were significantly more abundant in gill than in gut. Taken together, these results provide the first evidence that at least two carbon fixation pathways are present in both the gill and the gut communities of A. longirostris, and that the communities in different tissues likely differ in autotrophic productivity.

  1. Lithospheric Structure and Active Deformation in the Salton Trough from Coseismic and Postseismic Models of the 2010 Mw 7.2 El Mayor-Cucapah Earthquake

    Science.gov (United States)

    Fielding, E. J.; Huang, M. H.; Dickinson, H.; Freed, A. M.; Burgmann, R.; Gonzalez-Ortega, J. A.; Andronicos, C.

    2016-12-01

    The 4 April 2010 Mw 7.2 El Mayor-Cucapah (EMC) Earthquake ruptured about 120 km along several NW-striking faults to the west of the Cerro Prieto Fault in the Salton Trough of Baja California, Mexico. We analyzed interferometric synthetic aperture radar (SAR), SAR and optical pixel offsets, and continuous and campaign GPS data to optimize an EMC coseismic rupture model with 9 fault segments, which fits the complex structure of the faults. Coseismic slip inversion with a layered elastic model shows that largely right-lateral slip is confined to upper 10 km with strong variations along strike. Near-field GPS measures slip on a north-striking normal fault that ruptured at the beginning of the earthquake, previously inferred from seismic waveforms. EMC Earthquake postseismic deformation shows the Earth's response to the large coseismic stress changes. InSAR shows rapid shallow afterslip at the north and south ends of the main ruptures. Continuous GPS from the Plate Boundary Observatory operated by UNAVCO measures the first six years of postseismic deformation, extremely rapid near the rupture. Afterslip on faults beneath the coseismic rupture cannot explain far-field displacements that are best explained by viscoelastic relaxation of the lower crust and upper mantle. We built a viscoelastic 3D finite element model of the lithosphere and asthenosphere based on available data for the region with the EMC coseismic faults embedded inside. Coseismic slip was imposed on the model, allowed to relax for 5 years, and then compared to the observed surface deformation. Systematic exploration of the viscoelastic parameters shows that horizontal and vertical heterogeneity is required to fit the postseismic deformation. Our preferred viscoelastic model has weaker viscosity layers beneath the Salton Trough than adjacent blocks that are consistent with the inferred differences in the geotherms. Defining mechanical lithosphere as rocks that have viscosities greater than 10^19 Pa s (able

  2. Structuring mobile and contextual learning

    NARCIS (Netherlands)

    Glahn, Christian; Specht, Marcus

    2011-01-01

    Glahn, C., & Specht, M. (2011). Structuring mobile and contextual learning. In Proceedings of the 10th World Conference on Mobile and Contextual Learning (pp. 188-195). October, 18-21, 2011, Beijing, China.

  3. Social Structures for Learning

    NARCIS (Netherlands)

    I.M. Bogenrieder (Irma); B. Nooteboom (Bart)

    2001-01-01

    textabstractThis article investigates what learning groups there are in organizations, other than the familiar 'communities of practice'. It first develops an interdisciplinary theoretical framework for identifying, categorizing and understanding learning groups. For this, it employs a

  4. Social Structures for Learning

    OpenAIRE

    Bogenrieder, I.M.; Nooteboom, B.

    2001-01-01

    textabstractThis article investigates what learning groups there are in organizations, other than the familiar 'communities of practice'. It first develops an interdisciplinary theoretical framework for identifying, categorizing and understanding learning groups. For this, it employs a constructivist, interactionist theory of knowledge and learning. It employs elements of transaction cost theory and of social theory of trust. Transaction cost economics neglects learning and trust, but element...

  5. Structure Mapping for Social Learning.

    Science.gov (United States)

    Christie, Stella

    2017-07-01

    Analogical reasoning is a foundational tool for human learning, allowing learners to recognize relational structures in new events and domains. Here I sketch some grounds for understanding and applying analogical reasoning in social learning. The social world is fundamentally characterized by relations between people, with common relational structures-such as kinships and social hierarchies-forming social units that dictate social behaviors. Just as young learners use analogical reasoning for learning relational structures in other domains-spatial relations, verbs, relational categories-analogical reasoning ought to be a useful cognitive tool for acquiring social relations and structures. Copyright © 2017 Cognitive Science Society, Inc.

  6. Characterization of structures of the Nankai Trough accretionary prism from integrated analyses of LWD log response, resistivity images and clay mineralogy of cuttings: Expedition 338 Site C0002

    Science.gov (United States)

    Jurado, Maria Jose; Schleicher, Anja

    2014-05-01

    The objective of our research is a detailed characterization of structures on the basis of LWD oriented images and logs,and clay mineralogy of cuttings from Hole C0002F of the Nankai Trough accretionary prism. Our results show an integrated interpretation of structures derived from borehole images, petrophysical characterization on LWD logs and cuttings mineralogy. The geometry of the structure intersected at Hole C0002F has been characterized by the interpretation of oriented borehole resistivity images acquired during IODP Expedition 338. The characterization of structural features, faults and fracture zones is based on a detailed post-cruise interpretation of bedding and fractures on borehole images and also on the analysis of Logging While Drilling (LWD) log response (gamma radioactivity, resistivity and sonic logs). The interpretation and complete characterization of structures (fractures, fracture zones, fault zones, folds) was achieved after detailed shorebased reprocessing of resistivity images, which allowed to enhance bedding and fracture's imaging for geometry and orientation interpretation. In order to characterize distinctive petrophysical properties based on LWD log response, it could be compared with compositional changes derived from cuttings analyses. Cuttings analyses were used to calibrate and to characterize log response and to verify interpretations in terms of changes in composition and texture at fractures and fault zones defined on borehole images. Cuttings were taken routinely every 5 m during Expedition 338, indicating a clay-dominated lithology of silty claystone with interbeds of weakly consolidated, fine sandstones. The main mineralogical components are clay minerals, quartz, feldspar and calcite. Selected cuttings were taken from areas of interest as defined on LWD logs and images. The clay mineralogy was investigated on the LWD) data allowed us to characterize structural, petrophysical and mineralogical properties at fracture and

  7. Structural equations in language learning

    NARCIS (Netherlands)

    Moortgat, M.J.

    In categorial systems with a fixed structural component, the learning problem comes down to finding the solution for a set of typeassignment equations. A hard-wired structural component is problematic if one want to address issues of structural variation. Our starting point is a type-logical

  8. Structure of the San Andreas Fault Zone in the Salton Trough Region of Southern California: A Comparison with San Andreas Fault Structure in the Loma Prieta Area of Central California

    Science.gov (United States)

    Fuis, G. S.; Catchings, R.; Scheirer, D. S.; Goldman, M.; Zhang, E.; Bauer, K.

    2016-12-01

    The San Andreas fault (SAF) in the northern Salton Trough, or Coachella Valley, in southern California, appears non-vertical and non-planar. In cross section, it consists of a steeply dipping segment (75 deg dip NE) from the surface to 6- to 9-km depth, and a moderately dipping segment below 6- to 9-km depth (50-55 deg dip NE). It also appears to branch upward into a flower-like structure beginning below about 10-km depth. Images of the SAF zone in the Coachella Valley have been obtained from analysis of steep reflections, earthquakes, modeling of potential-field data, and P-wave tomography. Review of seismological and geodetic research on the 1989 M 6.9 Loma Prieta earthquake, in central California (e.g., U.S. Geological Survey Professional Paper 1550), shows several features of SAF zone structure similar to those seen in the northern Salton Trough. Aftershocks in the Loma Prieta epicentral area form two chief clusters, a tabular zone extending from 18- to 9-km depth and a complex cluster above 5-km depth. The deeper cluster has been interpreted to surround the chief rupture plane, which dips 65-70 deg SW. When double-difference earthquake locations are plotted, the shallower cluster contains tabular subclusters that appear to connect the main rupture with the surface traces of the Sargent and Berrocal faults. In addition, a diffuse cluster may surround a steep to vertical fault connecting the main rupture to the surface trace of the SAF. These interpreted fault connections from the main rupture to surface fault traces appear to define a flower-like structure, not unlike that seen above the moderately dipping segment of the SAF in the Coachella Valley. But importantly, the SAF, interpreted here to include the main rupture plane, appears segmented, as in the Coachella Valley, with a moderately dipping segment below 9-km depth and a steep to vertical segment above that depth. We hope to clarify fault-zone structure in the Loma Prieta area by reanalyzing active

  9. Movements of the mid-latitude ionospheric trough

    International Nuclear Information System (INIS)

    Rodger, A.S.; Pinnock, M.

    1982-01-01

    A new method for monitoring the position and movement of large ionospheric structures is described. The technique uses data from an ionosonde nominally operating at vertical incidence, but relies on there being present a significant gradient in electron concentration. The position and dynamics of the poleward edge of the mid-latitude trough over Halley Bay, Antarctica (L = 4.2) is investigated using this method. Analyses show that the trough moves rapidly equatorward over Halley Bay in the early evening hours, during geomagnetically active periods. For magnetically quiet periods, the trough is not observed till after midnight, when its equatorward motion is comparatively slow. These results showed marked differences from those predicted from published empirical relationships describing variations in trough position with time, particularly before midnight. Changes in the position of the plasma pause with time, determined from two theoretical models and from observations are compared with these results for the trough. Also, one case study is presented in which there is determination of the positions of both the trough and the plasmapause over a 7 h period. Similarities and differences in their relative positions and movements of the two features are identified and their possible causes are briefly discussed. (author)

  10. Distance Learning Plan Development: Initiating Organizational Structures

    National Research Council Canada - National Science Library

    Poole, Clifton

    1998-01-01

    .... Army distance learning plan managers to examine the DLPs they were directing. The analysis showed that neither army nor civilian distance learning plan managers used formalized requirements for organizational structure development (OSD...

  11. Improvement Design of Parabolic Trough

    Science.gov (United States)

    Ihsan, S. I.; Safian, M. A. I. M.; Taufek, M. A. M.; Mohiuddin, A. K. M.

    2017-03-01

    The performance of parabolic trough solar collector (PTSC) has been evaluated using different heat transfer working fluids; namely water and SAE20 W50 engine oil. New and slightly improved PTSC was developed to run the experimental study. Under the meteorological conditions of Malaysia, authors found that PTSC can operate at a higher temperature than water collector but the performance efficiency of collector using engine oil is much lower than the water collector.

  12. ON TECTONIC PROBLEMS OF THE OKINAWA TROUGH

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Okinawa Trough is a very active tectonic zone at the margin of the Northwest Pacific and is typical of back-arc rifting at the young stage of tectonic evolution. Many scientists from Japan, China, Germany, France, the U.S.A. and Russia have done a lot of geologic and geophysical investigations there. It is well known that the Okinawa Trough is an active back-arc rift with extremely high heat flow, very strong hydrothermal circulation, strong volcanic and magmatic activity, frequent earthquakes, rapid subsidence and rifting, well-developed fault and central graben. But up to now, there are still some important tectonic problems about the Okinawa Trough that require clarification on some aspects such as the type of its crust, its forming time, its tectonic evolution, the distribution of its central grabens, the relationship between its high heat flow and tectonic activity. Based on the data obtained from seismic survey, geomagnetic and gravity measurements, submarine sampling and heat flow measurements in the last 15 years, the author discusses the following tectonic problems about the Okinawa Trough: (1) If the Okinawa Trough develops oceanic crust or not. (2) Is the South Okinawa Trough tectonically more active than the North Okinawa Trough with shallower water and few investigation data on it. (3) The formation time of the Okinawa Trough and its tectonic evolution. The Okinawa Trough has a very thin continental crust. Up to now, there is no evidence of oceanic crust in the Okinawa Trough. The North, Middle and South Okinawa Trough are all very strongly active areas. From 6 Ma B.P., the Okinawa Trough began to form. Since 2 Ma, the Okinawa Trough has been very active.

  13. ON TECTONIC PROBLEMS OF THE OKINAWA TROUGH

    Institute of Scientific and Technical Information of China (English)

    李乃胜

    2001-01-01

    The Okinawa Trough is a very active tectonic zone at the margin of the Northwest Pacific and is typical of back-arc rifting at the young stage of tectonic evolution. Many scientists from Japan,China, Germany, France, the U. S.A. and Russia have done a lot of geologic and geophysical investigations there. It is well known that the Okinawa Trough is an active back-arc rift with extremely high heat flow, very strong hydrothermal circulation, strong volcanic and magmatic activity, frequent earthquakes,rapid subsidence and rifting, well-developed fault and central graben. But up to now, there are still some important tectonic problems about the Okinawa Trough that require clarification on some aspects such as the type of its crust, its forming time, its tectonic evolution, the distribution of its central grabens, the relationship between its high heat flow and tectonic activity. Based on the data obtained from seismic sur-vey, geomagnetic and gravity measurements, submarine sampling and heat flow measurements in the last 15 years, the author discusses the following tectonic problems about the Okinawa Trough: (1) If the Okinawa Trough develops oceanic crust or not. (2) Is the South Okinawa Trough tectonically more active than the North Okinawa Trough with shallower water and few investigation data on it. (3) The formation time of the Okinawa Trough and its tectonic evolution. The Okinawa Trough has a very thin continental crust. Up to now, there is no evidence of oceanic crust in the Okinawa Trough. The North, Middle and South Okinawa Trough are all very strongly active areas. From 6 Ma B.P. , the Okinawa Trough began to form. Since 2 Ma, the Okinawa Trough has been very active.

  14. Gravity Anomalies Over The Gongola Arm, Upper Benue Trough ...

    African Journals Online (AJOL)

    A regional gravity survey of the Gongola Arm of the Benue trough was carried out with the aim of determining structures of interest. The results of the gravity interpretation showed that the area of study is characterized by negative Bouguer anomalies that trend in the NE-SW direction and range in value from -75 to -15 mGal ...

  15. Advanced photovoltaic-trough development

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, R.; Yasuda, K.; Merson, B.

    1982-04-01

    The scope of the work on photvoltaic troughs includes analytical studies, hardware development, and component testing. Various aspects of the system have been optimized and improvements have been realized, particularly in the receiver and reflecting surface designs. An empirical system performance model has been developed that closely agrees with measured system performance. This in-depth study of single-axis reflecting linear focus photovoltaic concentrators will be very beneficial in the development of improved models for similar systems as well as other phtovoltaic concentrator designs.

  16. The structuration of organizational learning

    NARCIS (Netherlands)

    Berends, J.J.; Boersma, F.K.; Weggeman, M.C.D.P.

    2003-01-01

    Although it is currently common to speak of organizational learning, this notion is still surrounded by conceptual confusion. It is unclear how notions like learning, knowledge and cognitive activities can be applied to organizations. Some authors have tried to unravel the conceptual and ontological

  17. The structuration of organizational learning

    NARCIS (Netherlands)

    Berends, J.J.; Boersma, F.K.; Weggeman, M.C.D.P.

    2001-01-01

    Although it is currently common to speak of organizational learning, this notion is still surrounded by conceptual confusion. It is unclear how notions like learning, knowledge and cognitive activities can be applied to organizations. Some authors have tried to unravel the conceptual and ontological

  18. Fabrication of trough-shaped solar collectors

    Science.gov (United States)

    Schertz, William W.

    1978-01-01

    There is provided a radiant energy concentration and collection device formed of a one-piece thin-walled plastic substrate including a plurality of nonimaging troughs with certain metallized surfaces of the substrate serving as reflective side walls for each trough. The one-piece plastic substrate is provided with a seating surface at the bottom of each trough which conforms to the shape of an energy receiver to be seated therein.

  19. Petroleum resources assessment of the Okinawa Trough

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Jae Ho; Kwak, Young Hoon; Bong, Pil Yoon; Son, Jin Dam; Cheong, Tae Jin; Lee, Ho Young; Ryu, Byung Jae; Son, Byeong Kook; Hwang, In Gul; Kwon, Young Ihn; Lee, Yong Joo; Kim, Hag Ju; Yi, Sung Soog; Park, Kwan Soon; Park, Keun Pil; Shin, Chang Soo; Sunwoo, Don [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    The hydrocarbon potential has been evaluated for the Tertiary strata in the northwestern margin of the Okinawa Trough on the basis of the pale-ontological, petrological, geochemical data from two wells (Nikkan 8-9 and JDZ 7-3), and geophysical data. Abundant marine micro-fossils such as foraminifera, calcareous nannofossils and dinocysts were yielded in the sedimentary section of the above wells. Abundant palynomorphs originated from nearby onshore are also encountered. Based on nannofossils, the bio-stratigraphic zones from NN12 (Amaurolithus tricorniculatus Zone) to NN19 (Pseudoemiliania lacunosa Zone) are established. The sedimentary sequences are divided by local unconformity into Lower and Upper Groups, the ages of which are Late Miocene and Pliocene to Pleistocene, respectively. According to the geochemical analysis results, it is hard to expect a source rock that can generate enough hydrocarbons necessary for migration in the drilled intervals. Even though the thermal maturity reached the oil generation zone in the penetrated intervals, the calculation by the program GENEX of BEICIP shows that the amount of the generated hydrocarbons is not enough for the migration. A good source rock may be expected in the depth deeper than 4300 m horizon. Analysis of over 3300 Line-km of multichannel seismic data integrated with 2 well data serves to detail the structural and stratigraphic evolution of the western margin of the Okinawa Trough, offshore southern part of Korea peninsula. The overall tectonic style is characterized by a series of half-Graben and tilted fault blocks bounded by listric faults. Tectonics of the rift phase have been established on the basis of structural and stratigraphic analyses of depositional sequences and their seismic expressions. The potential hydrocarbon traps associated with titled fault block, fault and roll-over structure exist. (author). 44 refs.

  20. Structured Learning Teams: Reimagining Student Group Work

    Science.gov (United States)

    Lendvay, Gregory C.

    2014-01-01

    Even in a standards-based curriculum, teachers can apply constructivist practices such as structured learning teams. In this environment, students become invested in the learning aims, triggering the desire in students to awaken, get information, interpret, remix, share, and design scenarios.

  1. Tectonics of the southern Bleckenstedt trough in the mining area of the oolitic iron ore deposit (midle coral oolithe) of Konrad mine near Salzgitter, Lower Saxony

    International Nuclear Information System (INIS)

    Schloenbach, R.

    1985-01-01

    The regional tectonic development of the Bleckenstedt trough and the large-scale faults in Konrad mine (N-S, trough fault, NW-SE, Sauingen trough, E-W, Bleckenstedt fault), which date from a different period, were evaluated, and a tectogenetic analysis of the small-scale tectonic structure was related to halokinetic movements. (DG) [de

  2. New sidescan sonar and gravity evidence that the Nova-Canton Trough is a fracture zone

    Science.gov (United States)

    Joseph, Devorah; Taylor, Brian; Shor, Alexander N.

    1992-05-01

    A 1990 sidescan sonar survey in the eastern region of the Nova-Canton Trough mapped 138°-striking abyssal-hill fabric trending into 70°-striking trough structures. The location and angle of intersection of the abyssal hills with the eastern Nova-Canton Trough effectively disprove a spreading-center origin of this feature. Free-air gravity anomalies derived from satellite altimetry data show continuity, across the Line Islands, of the Nova-Canton Trough with the Clipperton Fracture Zone. The Canton-Clipperton trend is copolar, about a pole at 30°S, 152°W, with other coeval Pacific-Farallon fracture-zone segments, from the Pau to Marquesas fracture zones. This copolarity leads us to postulate a Pacific-Farallon spreading pattern for the magnetic quiet zone region north and east of the Manihiki Plateau, with the Nova-Canton Trough originating as a transform fault in this system.

  3. Wind Tunnel Tests of Parabolic Trough Solar Collectors: March 2001--August 2003

    Energy Technology Data Exchange (ETDEWEB)

    Hosoya, N.; Peterka, J. A.; Gee, R. C.; Kearney, D.

    2008-05-01

    Conducted extensive wind-tunnel tests on parabolic trough solar collectors to determine practical wind loads applicable to structural design for stress and deformation, and local component design for concentrator reflectors.

  4. Paleocene Pacific Plate reorganization mirrored in formation of the Suvarov Trough, Manihiki Plateau

    Science.gov (United States)

    Pietsch, Ricarda; Uenzelmann-Neben, Gabriele

    2016-10-01

    The Suvarov Trough is a graben structure that deviates from the Danger Islands Troughs within the Manihiki Plateau, a Large Igneous Province (LIP) located in the Central Pacific. New high-resolution seismic reflection data provide evidence that the graben formed in two phases during the Paleocene (65-45 Ma). In a first phase extension occurred in southwestward direction, pulling apart the northern part of the Suvarov Trough and a parallel trending unnamed trough. In a second phase a change of extensional force direction occurred from southwest to west-northwest, forming the southern part of the Suvarov Trough that extends onto the High Plateau. The formation of the Suvarov Trough is accompanied by a series of normal fault systems that apparently formed simultaneously. Comparing the seismic results to existing Pacific paleo strain reconstructions, the timing of increased strain and local deformation direction fits well to our findings. We thus suggest that the multiple strike directions of the Suvarov Trough represent an extensional structure that was caused by the major, stepwise Pacific Plate reorganization during the Paleocene.

  5. Rate-Agnostic (Causal) Structure Learning.

    Science.gov (United States)

    Plis, Sergey; Danks, David; Freeman, Cynthia; Calhoun, Vince

    2015-12-01

    Causal structure learning from time series data is a major scientific challenge. Extant algorithms assume that measurements occur sufficiently quickly; more precisely, they assume approximately equal system and measurement timescales. In many domains, however, measurements occur at a significantly slower rate than the underlying system changes, but the size of the timescale mismatch is often unknown. This paper develops three causal structure learning algorithms, each of which discovers all dynamic causal graphs that explain the observed measurement data, perhaps given undersampling. That is, these algorithms all learn causal structure in a "rate-agnostic" manner: they do not assume any particular relation between the measurement and system timescales. We apply these algorithms to data from simulations to gain insight into the challenge of undersampling.

  6. The sharp peak-flat trough pattern and critical speculation

    OpenAIRE

    Roehner, B. M.; Sornette, D.

    1998-01-01

    We find empirically a characteristic sharp peak-flat trough pattern in a large set of commodity prices. We argue that the sharp peak structure reflects an endogenous inter-market organization, and that peaks may be seen as local ``singularities'' resulting from imitation and herding. These findings impose a novel stringent constraint on the construction of models. Intermittent amplification is not sufficient and nonlinear effects seem necessary to account for the observations.

  7. Density structure of submarine slump and normal sediments of the first gas production test site at Daini-Atsumi Knoll near Nankai Trough, estimated by LWD logging data

    Science.gov (United States)

    Suzuki, K.; Takayama, T.; Fujii, T.; Yamamoto, K.

    2014-12-01

    Many geologists have discussed slope instability caused by gas-hydrate dissociation, which could make movable fluid in pore space of sediments. However, physical property changes caused by gas hydrate dissociation would not be so simple. Moreover, during the period of natural gas-production from gas-hydrate reservoir applying depressurization method would be completely different phenomena from dissociation processes in nature, because it could not be caused excess pore pressure, even though gas and water exist. Hence, in all cases, physical properties of gas-hydrate bearing sediments and that of their cover sediments are quite important to consider this phenomena, and to carry out simulation to solve focusing phenomena during gas hydrate dissociation periods. Daini-Atsumi knoll that was the first offshore gas-production test site from gas-hydrate is partially covered by slumps. Fortunately, one of them was penetrated by both Logging-While-Drilling (LWD) hole and pressure-coring hole. As a result of LWD data analyses and core analyses, we have understood density structure of sediments from seafloor to Bottom Simulating Reflector (BSR). The results are mentioned as following. ・Semi-confined slump showed high-density, relatively. It would be explained by over-consolidation that was result of layer-parallel compression caused by slumping. ・Bottom sequence of slump has relative high-density zones. It would be explained by shear-induced compaction along slide plane. ・Density below slump tends to increase in depth. It is reasonable that sediments below slump deposit have been compacting as normal consolidation. ・Several kinds of log-data for estimating physical properties of gas-hydrate reservoir sediments have been obtained. It will be useful for geological model construction from seafloor until BSR. We can use these results to consider geological model not only for slope instability at slumping, but also for slope stability during depressurized period of gas

  8. Ionospheric trough Model used for Telecommunication Purposes

    International Nuclear Information System (INIS)

    Rothkaehl, H.; Stanislawska, I.

    1999-01-01

    The mid-latitude trough is dynamical phenomena influenced the COST 251 area. Modelled parameters in COST 251 project are critically dependent on its location and magnitude. The particular importance to HF propagation assessments involving off-great-circle modes of incorporating a representation of the position of the trough is noted. ITU-R prediction maps (ITU-R, 1997) which are currently used in most international propagation assessments do not include this fact. (author)

  9. Learning Latent Structure in Complex Networks

    DEFF Research Database (Denmark)

    Mørup, Morten; Hansen, Lars Kai

    such as the Modularity, it has recently been shown that latent structure in complex networks is learnable by Bayesian generative link distribution models (Airoldi et al., 2008, Hofman and Wiggins, 2008). In this paper we propose a new generative model that allows representation of latent community structure......Latent structure in complex networks, e.g., in the form of community structure, can help understand network dynamics, identify heterogeneities in network properties, and predict ‘missing’ links. While most community detection algorithms are based on optimizing heuristic clustering objectives...... as in the previous Bayesian approaches and in addition allows learning of node specific link properties similar to that in the modularity objective. We employ a new relaxation method for efficient inference in these generative models that allows us to learn the behavior of very large networks. We compare the link...

  10. Analysis of Earthquake Source Spectra in Salton Trough

    Science.gov (United States)

    Chen, X.; Shearer, P. M.

    2009-12-01

    Previous studies of the source spectra of small earthquakes in southern California show that average Brune-type stress drops vary among different regions, with particularly low stress drops observed in the Salton Trough (Shearer et al., 2006). The Salton Trough marks the southern end of the San Andreas Fault and is prone to earthquake swarms, some of which are driven by aseismic creep events (Lohman and McGuire, 2007). In order to learn the stress state and understand the physical mechanisms of swarms and slow slip events, we analyze the source spectra of earthquakes in this region. We obtain Southern California Seismic Network (SCSN) waveforms for earthquakes from 1977 to 2009 archived at the Southern California Earthquake Center (SCEC) data center, which includes over 17,000 events. After resampling the data to a uniform 100 Hz sample rate, we compute spectra for both signal and noise windows for each seismogram, and select traces with a P-wave signal-to-noise ratio greater than 5 between 5 Hz and 15 Hz. Using selected displacement spectra, we isolate the source spectra from station terms and path effects using an empirical Green’s function approach. From the corrected source spectra, we compute corner frequencies and estimate moments and stress drops. Finally we analyze spatial and temporal variations in stress drop in the Salton Trough and compare them with studies of swarms and creep events to assess the evolution of faulting and stress in the region. References: Lohman, R. B., and J. J. McGuire (2007), Earthquake swarms driven by aseismic creep in the Salton Trough, California, J. Geophys. Res., 112, B04405, doi:10.1029/2006JB004596 Shearer, P. M., G. A. Prieto, and E. Hauksson (2006), Comprehensive analysis of earthquake source spectra in southern California, J. Geophys. Res., 111, B06303, doi:10.1029/2005JB003979.

  11. E-LEARNING TOOLS: STRUCTURE, CONTENT, CLASSIFICATION

    Directory of Open Access Journals (Sweden)

    Yuliya H. Loboda

    2012-05-01

    Full Text Available The article analyses the problems of organization of educational process with use of electronic means of education. Specifies the definition of "electronic learning", their structure and content. Didactic principles are considered, which are the basis of their creation and use. Given the detailed characteristics of e-learning tools for methodological purposes. On the basis of the allocated pedagogical problems of the use of electronic means of education presented and complemented by their classification, namely the means of theoretical and technological training, means of practical training, support tools, and comprehensive facilities.

  12. Characteristic imsets for learning Bayesian network structure

    Czech Academy of Sciences Publication Activity Database

    Hemmecke, R.; Lindner, S.; Studený, Milan

    2012-01-01

    Roč. 53, č. 9 (2012), s. 1336-1349 ISSN 0888-613X R&D Projects: GA MŠk(CZ) 1M0572; GA ČR GA201/08/0539 Institutional support: RVO:67985556 Keywords : learning Bayesian network structure * essential graph * standard imset * characteristic imset * LP relaxation of a polytope Subject RIV: BA - General Mathematics Impact factor: 1.729, year: 2012 http://library.utia.cas.cz/separaty/2012/MTR/studeny-0382596.pdf

  13. A Decomposition Algorithm for Learning Bayesian Network Structures from Data

    DEFF Research Database (Denmark)

    Zeng, Yifeng; Cordero Hernandez, Jorge

    2008-01-01

    It is a challenging task of learning a large Bayesian network from a small data set. Most conventional structural learning approaches run into the computational as well as the statistical problems. We propose a decomposition algorithm for the structure construction without having to learn...... the complete network. The new learning algorithm firstly finds local components from the data, and then recover the complete network by joining the learned components. We show the empirical performance of the decomposition algorithm in several benchmark networks....

  14. Using Cooperative Structures to Promote Deep Learning

    Science.gov (United States)

    Millis, Barbara J.

    2014-01-01

    The author explores concrete ways to help students learn more and have fun doing it while they support each other's learning. The article specifically shows the relationships between cooperative learning and deep learning. Readers will become familiar with the tenets of cooperative learning and its power to enhance learning--even more so when…

  15. OUT Success Stories: Solar Trough Power Plants

    Science.gov (United States)

    Jones, J.

    2000-08-01

    The Solar Electric Generating System (SEGS) plants use parabolic-trough solar collectors to capture the sun's energy and convert it to heat. The SEGS plants range in capacity from 13.8 to 80 MW, and they were constructed to meet Southern California Edison Company's periods of peak power demand.

  16. Structure Learning in Power Distribution Networks

    Energy Technology Data Exchange (ETDEWEB)

    Deka, Deepjyoti [Univ. of Texas, Austin, TX (United States); Chertkov, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Backhaus, Scott N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-01-13

    Traditionally power distribution networks are either not observable or only partially observable. This complicates development and implementation of new smart grid technologies, such as these related to demand response, outage detection and management, and improved load-monitoring. Here, inspired by proliferation of the metering technology, we discuss statistical estimation problems in structurally loopy but operationally radial distribution grids consisting in learning operational layout of the network from measurements, e.g. voltage data, which are either already available or can be made available with a relatively minor investment. Our newly suggested algorithms apply to a wide range of realistic scenarios. The algorithms are also computationally efficient – polynomial in time – which is proven theoretically and illustrated computationally on a number of test cases. The technique developed can be applied to detect line failures in real time as well as to understand the scope of possible adversarial attacks on the grid.

  17. Tracking influence between naive Bayes models using score-based structure learning

    CSIR Research Space (South Africa)

    Ajoodha, R

    2017-11-01

    Full Text Available Current structure learning practices in Bayesian networks have been developed to learn the structure between observable variables and learning latent parameters independently. One exception establishes a variant of EM for learning the structure...

  18. The Structural Underpinnings of Policy Learning: A Classroom Policy Simulation

    Science.gov (United States)

    Bird, Stephen

    This paper investigates the relationship between the centrality of individual actors in a social network structure and their policy learning performance. In a dynamic comparable to real-world policy networks, results from a classroom simulation demonstrate a strong relationship between centrality in social learning networks and grade performance. Previous research indicates that social network centrality should have a positive effect on learning in other contexts and this link is tested in a policy learning context. Second, the distinction between collaborative learning versus information diffusion processes in policy learning is examined. Third, frequency of interaction is analyzed to determine whether consistent, frequent tics have a greater impact on the learning process. Finally, the data arc analyzed to determine if the benefits of centrality have limitations or thresholds when benefits no longer accrue. These results demonstrate the importance of network structure, and support a collaborative conceptualization of the policy learning process.

  19. A trough for improved SFG spectroscopy of lipid monolayers

    Science.gov (United States)

    Franz, Johannes; van Zadel, Marc-Jan; Weidner, Tobias

    2017-05-01

    Lipid monolayers are indispensable model systems for biological membranes. The main advantage over bilayer model systems is that the surface pressure within the layer can be directly and reliably controlled. The sensitive interplay between surface pressure and temperature determines the molecular order within a model membrane and consequently determines the membrane phase behavior. The lipid phase is of crucial importance for a range of membrane functions such as protein interactions and membrane permeability. A very reliable method to probe the structure of lipid monolayers is sum frequency generation (SFG) vibrational spectroscopy. Not only is SFG extremely surface sensitive but it can also directly access critical parameters such as lipid order and orientation, and it can provide valuable information about protein interactions along with interfacial hydration. However, recent studies have shown that temperature gradients caused by high power laser beams perturb the lipid layers and potentially obscure the spectroscopic results. Here we demonstrate how the local heating problem can be effectively reduced by spatially distributing the laser pulses on the sample surface using a translating Langmuir trough for SFG experiments at lipid monolayers. The efficiency of the trough is illustrated by the detection of enhanced molecular order due to reduced heat load.

  20. Structural Learning Theory: Current Status and New Perspectives.

    Science.gov (United States)

    Scandura, Joseph M.

    2001-01-01

    Presents the current status and new perspectives on the Structured Learning Theory (SLT), with special consideration given to how SLT has been influenced by recent research in software engineering. Topics include theoretical constructs; content domains; structural analysis; cognition; assessing behavior potential; and teaching and learning issues,…

  1. Optical properties of V-trough concentrators

    Energy Technology Data Exchange (ETDEWEB)

    Fraidenraich, N. [Universidade Federal de Pernambuco, Recife, PE Brasil (Brazil); Almeida, G. J.

    1991-07-01

    A new approach to study the optical behavior of V-trough concentrators is developed, based on the use of three characteristic angles defining the appearance, disappearance and return to the outside space of the cavity of a reflection mode. The probability of occurrence of a given number of reflections for beam radiation is determined as a function of these angles and the optical efficiency calculated. It is shown that the optical efficiency can be approximated by a function of two parameters, the angular acceptance function, T, and the mean number of reflections, n, as T * p{sup n/T}. Deviations between exact and approximate optical efficiency increase as n increases or as p decreases. For troughs with C ≤ 2.5 the maximal error for beam radiation is 3.4% for p ≥ 0.8 (8.3% for p ≥ 0.7). For diffuse radiation the maximal error is less than 2% for configurations whose optical efficiency is above 0.6. A further simplification was introduced to obtain the optical efficiency for diffuse radiation, approximating T by an analytical expression and n by an empirical linear function of the inverse of the vertex angle. Results accurate up to 5% for p = 0.8, were obtained. Increasing the concentration ratio, C, from 1.5 to 2.5 for a vertex angle being one third of the acceptance angle, decreased the optical efficiency from 0.74 to 0.59, for p = 0.8. For a given C, the dependence of the optical efficiency on the vertex angle is rather weak, suggesting that large trough angles might be favoured by cost-benefit analysis. (author)

  2. Bringing Context and Structure Back into Situated Learning

    DEFF Research Database (Denmark)

    Hotho, Jasper J.; Saka-Helmhout, Ayse; Becker-Ritterspach, Florian

    2014-01-01

    Practice-based studies have progressed thinking in the knowledge, learning and innovation fields by emphasizing the continual negotiation of social structures and meaning through participation. Yet, only a few contributions discuss how participation and learning are affected by broader structures....... This is an inconsistency in the understanding of ‘situated’ learning where learning through participation is restricted to the immediate community involved in a social activity. We aim to address this inconsistency by investigating the effects of the interplay between institutional and organizational structures...... institutional systems.In contrast to older views, our case findings suggest that while the interplay between institutional context and organizational structure indeed matters, it does not determine collective participation and situated learning as actors can actively create solutions when structural conditions...

  3. Alignment method for parabolic trough solar concentrators

    Science.gov (United States)

    Diver, Richard B [Albuquerque, NM

    2010-02-23

    A Theoretical Overlay Photographic (TOP) alignment method uses the overlay of a theoretical projected image of a perfectly aligned concentrator on a photographic image of the concentrator to align the mirror facets of a parabolic trough solar concentrator. The alignment method is practical and straightforward, and inherently aligns the mirror facets to the receiver. When integrated with clinometer measurements for which gravity and mechanical drag effects have been accounted for and which are made in a manner and location consistent with the alignment method, all of the mirrors on a common drive can be aligned and optimized for any concentrator orientation.

  4. Causal imprinting in causal structure learning.

    Science.gov (United States)

    Taylor, Eric G; Ahn, Woo-Kyoung

    2012-11-01

    Suppose one observes a correlation between two events, B and C, and infers that B causes C. Later one discovers that event A explains away the correlation between B and C. Normatively, one should now dismiss or weaken the belief that B causes C. Nonetheless, participants in the current study who observed a positive contingency between B and C followed by evidence that B and C were independent given A, persisted in believing that B causes C. The authors term this difficulty in revising initially learned causal structures "causal imprinting." Throughout four experiments, causal imprinting was obtained using multiple dependent measures and control conditions. A Bayesian analysis showed that causal imprinting may be normative under some conditions, but causal imprinting also occurred in the current study when it was clearly non-normative. It is suggested that causal imprinting occurs due to the influence of prior knowledge on how reasoners interpret later evidence. Consistent with this view, when participants first viewed the evidence showing that B and C are independent given A, later evidence with only B and C did not lead to the belief that B causes C. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Deep learning and the electronic structure problem

    Science.gov (United States)

    Mills, Kyle; Spanner, Michael; Tamblyn, Isaac

    In the past decade, the fields of artificial intelligence and computer vision have progressed remarkably. Supported by the enthusiasm of large tech companies, as well as significant hardware advances and the utilization of graphical processing units to accelerate computations, deep neural networks (DNN) are gaining momentum as a robust choice for many diverse machine learning applications. We have demonstrated the ability of a DNN to solve a quantum mechanical eigenvalue equation directly, without the need to compute a wavefunction, and without knowledge of the underlying physics. We have trained a convolutional neural network to predict the total energy of an electron in a confining, 2-dimensional electrostatic potential. We numerically solved the one-electron Schrödinger equation for millions of electrostatic potentials, and used this as training data for our neural network. Four classes of potentials were assessed: the canonical cases of the harmonic oscillator and infinite well, and two types of randomly generated potentials for which no analytic solution is known. We compare the performance of the neural network and consider how these results could lead to future advances in electronic structure theory.

  6. The study of the focal trough in panoramic radiograph

    International Nuclear Information System (INIS)

    Park, C. S.; Kim, H. P.

    1982-01-01

    In the study of the focal trough of panoramic radiograph, using the Moritta company Panex EC a series of 48 exposures were taken with the 6-18 brass pins placed in the holes of the plastic model plate, then evaluated by 4 observers. The author analyzed the focal trough defined by the sharpness criteria and calculated the vertical and horizontal magnification range in the corrected focal trough. The results were as follows; 1. Continuous focal trough was not defined in the anterior region using a very high degree of sharpness. 2. As degree of sharpness used in the analysis became less, focal trough was continuous in the anterior and posterior regions, symmetrized bilaterally, and the widths of the focal trough increased more in the posterior region. 3. As sharpness criteria were reduced, the percentage range of image magnification increased in both vertical and horizontal magnification, and especially the percentage range of horizontal magnification was greater than that of vertical magnification.

  7. E-learning and the Educational Organizations Structure Reengineering (EOSR

    Directory of Open Access Journals (Sweden)

    Osama Alshara

    2007-06-01

    Full Text Available There are many calls for innovative learning methods that utilize advanced technologies. However, we will raise fundamental questions that look deep into the future of the educational organization. Can the educational institute survive without adapting learning technologies? Would the educational institute succeed in adapting new learning technologies without changing its organizational structure and processes? We claim that the answer to both questions is no. Our research will present the need for edu-cational institutes to incorporate learning technologies and focuses on the demand for the educational organization structure reengineering as a basic requirement for the suc-cess of incorporating learning technologies. Our study ex-plores the faculty requirements and policies and procedures of educational institutes in the UAE.The paper concludes with some discussions on findings from a case study of the need of educational organization struc-ture reengineering as a basic requirement for incorporating learning technologies.

  8. Motivated Learning with Digital Learning Tasks: What about Autonomy and Structure?

    Science.gov (United States)

    van Loon, Anne-Marieke; Ros, Anje; Martens, Rob

    2012-01-01

    In the present study, the ways in which digital learning tasks contribute to students' intrinsic motivation and learning outcomes were examined. In particular, this study explored the relative contributions of autonomy support and the provision of structure in digital learning tasks. Participants were 320 fifth- and sixth-grade students from eight…

  9. Structural Equation Modeling towards Online Learning Readiness, Academic Motivations, and Perceived Learning

    Science.gov (United States)

    Horzum, Mehmet Baris; Kaymak, Zeliha Demir; Gungoren, Ozlem Canan

    2015-01-01

    The relationship between online learning readiness, academic motivations, and perceived learning was investigated via structural equation modeling in the research. The population of the research consisted of 750 students who studied using the online learning programs of Sakarya University. 420 of the students who volunteered for the research and…

  10. Relationship between Online Learning Readiness and Structure and Interaction of Online Learning Students

    Science.gov (United States)

    Demir Kaymak, Zeliha; Horzum, Mehmet Baris

    2013-01-01

    Current study tried to determine whether a relationship exists between readiness levels of the online learning students for online learning and the perceived structure and interaction in online learning environments. In the study, cross sectional survey model was used. The study was conducted with 320 voluntary students studying online learning…

  11. Effects of External Learning Aids on Learning with Ill-Structured Hypertext.

    Science.gov (United States)

    Astleitner, Hermann

    1997-01-01

    Describes three experiments with high school and college students concerning learning with ill-structured hypertext; in each study, one different kind of external learning aid (memo pads, learning time, and teaching objectives) was manipulated and examined for its effect on intentional and incidental knowledge acquisition. Findings are discussed…

  12. Learning and structure of neuronal networks

    Indian Academy of Sciences (India)

    We study the effect of learning dynamics on network topology. Firstly, a network of discrete dynamical systems is considered for this purpose and the coupling strengths are made to evolve according to a temporal learning rule that is based on the paradigm of spike-time-dependent plasticity (STDP). This incorporates ...

  13. Influence of syllable structure on L2 auditory word learning.

    Science.gov (United States)

    Hamada, Megumi; Goya, Hideki

    2015-04-01

    This study investigated the role of syllable structure in L2 auditory word learning. Based on research on cross-linguistic variation of speech perception and lexical memory, it was hypothesized that Japanese L1 learners of English would learn English words with an open-syllable structure without consonant clusters better than words with a closed-syllable structure and consonant clusters. Two groups of college students (Japanese group, N = 22; and native speakers of English, N = 21) learned paired English pseudowords and pictures. The pseudoword types differed in terms of the syllable structure and consonant clusters (congruent vs. incongruent) and the position of consonant clusters (coda vs. onset). Recall accuracy was higher for the pseudowords in the congruent type and the pseudowords with the coda-consonant clusters. The syllable structure effect was obtained from both participant groups, disconfirming the hypothesized cross-linguistic influence on L2 auditory word learning.

  14. Robust Learning of Fixed-Structure Bayesian Networks

    OpenAIRE

    Diakonikolas, Ilias; Kane, Daniel; Stewart, Alistair

    2016-01-01

    We investigate the problem of learning Bayesian networks in an agnostic model where an $\\epsilon$-fraction of the samples are adversarially corrupted. Our agnostic learning model is similar to -- in fact, stronger than -- Huber's contamination model in robust statistics. In this work, we study the fully observable Bernoulli case where the structure of the network is given. Even in this basic setting, previous learning algorithms either run in exponential time or lose dimension-dependent facto...

  15. Learning Orthographic Structure with Sequential Generative Neural Networks

    Science.gov (United States)

    Testolin, Alberto; Stoianov, Ivilin; Sperduti, Alessandro; Zorzi, Marco

    2016-01-01

    Learning the structure of event sequences is a ubiquitous problem in cognition and particularly in language. One possible solution is to learn a probabilistic generative model of sequences that allows making predictions about upcoming events. Though appealing from a neurobiological standpoint, this approach is typically not pursued in…

  16. Structural Plasticity Denoises Responses and Improves Learning Speed

    Directory of Open Access Journals (Sweden)

    Robin Spiess

    2016-09-01

    Full Text Available Despite an abundance of computational models for learning of synaptic weights, there has been relatively little research on structural plasticity, i.e. the creation and elimination of synapses. Especially, it is not clear how structural plasticity works in concert with spike-timing-dependent plasticity (STDP and what advantages their combination offers.Here we present a fairly large-scale functional model that uses leaky integrate-and-fire neurons, STDP, homeostasis, recurrent connections, and structural plasticity to learn the input encoding, the relation between inputs, and to infer missing inputs. Using this model, we compare the error and the amount of noise in the network's responses with and without structural plasticity and the influence of structural plasticity on the learning speed of the network.Using structural plasticity during learning shows good results for learning the representation of input values, i.e. structural plasticity strongly reduces the noise of the response by preventing spikes with a high error.For inferring missing inputs we see similar results, with responses having less noise if the network was trained using structural plasticity.Additionally, using structural plasticity with pruning significantly decreased the time to learn weights suitable for inference.Presumably, this is due to the clearer signal containing less spikes that misrepresent the desired value. Therefore, this work shows that structural plasticity is not only able to improve upon the performance using STDP without structural plasticity but also speeds up learning.Additionally, it addresses the practical problem of limited resources for connectivity that is not only apparent in the mammalian neocortex but also in computer hardware or neuromorphic (brain-inspired hardware by efficiently pruning synapses without losing performance.

  17. Alleviate Cellular Congestion Through Opportunistic Trough Filling

    Directory of Open Access Journals (Sweden)

    Yichuan Wang

    2014-04-01

    Full Text Available The demand for cellular data service has been skyrocketing since the debut of data-intensive smart phones and touchpads. However, not all data are created equal. Many popular applications on mobile devices, such as email synchronization and social network updates, are delay tolerant. In addition, cellular load varies significantly in both large and small time scales. To alleviate network congestion and improve network performance, we present a set of opportunistic trough filling schemes that leverage the time-variation of network congestion and delay-tolerance of certain traffic in this paper. We consider average delay, deadline, and clearance time as the performance metrics. Simulation results show promising performance improvement over the standard schemes. The work shed lights on addressing the pressing issue of cellular overload.

  18. Learning Unknown Structure in CRFs via Adaptive Gradient Projection Method

    Directory of Open Access Journals (Sweden)

    Wei Xue

    2016-08-01

    Full Text Available We study the problem of fitting probabilistic graphical models to the given data when the structure is not known. More specifically, we focus on learning unknown structure in conditional random fields, especially learning both the structure and parameters of a conditional random field model simultaneously. To do this, we first formulate the learning problem as a convex minimization problem by adding an l_2-regularization to the node parameters and a group l_1-regularization to the edge parameters, and then a gradient-based projection method is proposed to solve it which combines an adaptive stepsize selection strategy with a nonmonotone line search. Extensive simulation experiments are presented to show the performance of our approach in solving unknown structure learning problems.

  19. Occlusion detection via structured sparse learning for robust object tracking

    KAUST Repository

    Zhang, Tianzhu; Ghanem, Bernard; Xu, Changsheng; Ahuja, Narendra

    2014-01-01

    occlusion through structured sparse learning. We test our tracker on challenging benchmark sequences, such as sports videos, which involve heavy occlusion, drastic illumination changes, and large pose variations. Extensive experimental results show that our

  20. Object tracking by occlusion detection via structured sparse learning

    KAUST Repository

    Zhang, Tianzhu; Ghanem, Bernard; Xu, Changsheng; Ahuja, Narendra

    2013-01-01

    occlusion through structured sparse learning. We test our tracker on challenging benchmark sequences, such as sports videos, which involve heavy occlusion, drastic illumination changes, and large pose variations. Experimental results show that our tracker

  1. The Nova-Canton Trough and the Late Cretaceous evolution of the central Pacific

    Science.gov (United States)

    Joseph, Devorah; Taylor, Brain; Shor, Alexander N.; Yamazaki, Toshitsugu

    Free-air gravity anomalies derived from satellite altimetry data show that the major Pacific fracture zones, from the Pau to Marquesas, are co-polar about an Euler pole located at 150.5°W, 34.6°S for the period preceding chron 33 and including a large portion of the Cretaceous Normal Superchron. They also show continuity of the Clipperton Fracture Zone through the Line Islands to the Nova-Canton ridge and trough; this Canton-Clipperton trend is co-polar to the same pole. Sidescan-sonar and bathymetry data in the Nova-Canton Trough region reveal N140°E-striking abyssal hill topography south of the N70°E-striking structures of the Nova-Canton Trough and crustal fabric striking normal to the trough (N160°E) to the north. We conclude that the Nova-Canton Trough is the Middle Cretaceous extension of the Clipperton Fracture Zone. We propose that the anomalous depths (7000-8400 m) of the trough between 167°30'-168°30'W are the result of a complex plate reorganization. Conjugate magnetic anomaly lineations M1-M3 in the Phoenix lineations between the Central Pacific Fracture Zone and the Phoenix Fracture Zone and the absence of lineations younger than anomaly M3 west of the Phoenix Fracture Zone suggest that spreading may have gradually ceased along the Pacific-Phoenix system from west to east. We infer that the remaining active segment of the Pacific-Phoenix spreading system after anomaly M1 time was the easternmost section of the Phoenix lineations. At ˜M0 time, the Pacific-Phoenix spreading axis stretched from lineated bathymetric depressions lying between 180°W and the Phoenix Islands to ˜168°W and included the western deep of the Nova-Canton Trough. We hypothesize that accretion terminated on the Pacific-Phoenix spreading axis shortly after M0 time and that the absence of an M0 isochron in the region between the eastern Phoenix lineations and the Nova-Canton Trough, or along the Nova-Canton Trough itself, may be due to a decrease in spreading rate prior to

  2. Early to middle Jurassic salt in Baltimore Canyon trough

    Science.gov (United States)

    McKinney, B. Ann; Lee, Myung W.; Agena, Warren F.; Poag, C. Wylie

    2005-01-01

    A pervasive, moderately deep (5-6 s two-way traveltime), high-amplitude reflection is traced on multichannel seismic sections over an approximately 7500 km² area of Baltimore Canyon Trough. The layer associated with the reflection is about 25 km wide, about 60 m thick in the center, and thins monotonically laterally, though asymmetrically, at the edges. Geophysical characteristics are compatible with an interpretation of this negative-polarity reflector as a salt lens deposited on the top of a synrift evaporite sequence. However, alternative interpretations of the layer as gas-saturated sediments, an overpressured shale, or a weathered igneous intrusion are also worthy of consideration.Geophysical analyses were made on three wavelet- and true-amplitude processed multichannel seismic dip lines. The lens-shaped layer demarked by the reflection has a velocity of 4.4 km/s; the lens lies within strata having velocities of 5.3 to 5.7 km/s. A trough marking the onset of the lens has an amplitude that is 10 to 20 db greater than reflections from the encasing layers and an apparent reflection coefficient of -0.24. Using amplitude versus offset analysis methods, we determined that observed reflection coefficients, though variable, decrease consistently with respect to increasing offset. Linear inversion yields a low density, about 2.2 g/cc. Integration of one of the true-amplitude-processed lines and one-dimensional modeling of the layer provide data on the impedance contrast and interference patterns that further reinforce the salt lens interpretation.The thin, horizontal salt lens was probably deposited or precipitated during the Jurassic in a shallow, narrow (peripheral) rift basin, as rifting progressed down the North Atlantic margin. Unlike thicker deposits in other areas that deformed and flowed, often into diapir structures, this thin lens has remained relatively undisturbed since deposition.

  3. Structural constraints on organisational and interorganisational learning

    DEFF Research Database (Denmark)

    Hjalager, Anne-Mette

    This paper examines the rates of mortality, survival and entrepreneurship in the Danish restaurant sector, and it demonstrates a considerable turbulence in the sector over the period 1980-1993. Opportunities for organizational learning is enhanced by size as well as age. However surprisingly......, survival is not clearly related to the managerial capacity. Neither is affiliation with other restaurants is an important factor for survival. The study indicates that learning in restaurants is decisively embedded in processes and technologies rather than in relation between human beings....

  4. Perceptual learning is specific to the trained structure of information.

    Science.gov (United States)

    Cohen, Yamit; Daikhin, Luba; Ahissar, Merav

    2013-12-01

    What do we learn when we practice a simple perceptual task? Many studies have suggested that we learn to refine or better select the sensory representations of the task-relevant dimension. Here we show that learning is specific to the trained structural regularities. Specifically, when this structure is modified after training with a fixed temporal structure, performance regresses to pretraining levels, even when the trained stimuli and task are retained. This specificity raises key questions as to the importance of low-level sensory modifications in the learning process. We trained two groups of participants on a two-tone frequency discrimination task for several days. In one group, a fixed reference tone was consistently presented in the first interval (the second tone was higher or lower), and in the other group the same reference tone was consistently presented in the second interval. When following training, these temporal protocols were switched between groups, performance of both groups regressed to pretraining levels, and further training was needed to attain postlearning performance. ERP measures, taken before and after training, indicated that participants implicitly learned the temporal regularity of the protocol and formed an attentional template that matched the trained structure of information. These results are consistent with Reverse Hierarchy Theory, which posits that even the learning of simple perceptual tasks progresses in a top-down manner, hence can benefit from temporal regularities at the trial level, albeit at the potential cost that learning may be specific to these regularities.

  5. Personalized search result diversification via structured learning

    NARCIS (Netherlands)

    Liang, S.; Ren, Z.; de Rijke, M.

    2014-01-01

    This paper is concerned with the problem of personalized diversification of search results, with the goal of enhancing the performance of both plain diversification and plain personalization algorithms. In previous work, the problem has mainly been tackled by means of unsupervised learning. To

  6. Acoustically damped metal oil trough for internal combustion engines. Schallgedaempfte Blech-Oelwanne fuer Brennkraftmaschinen

    Energy Technology Data Exchange (ETDEWEB)

    Kubis, H.

    1991-03-28

    The invention refers to an acoustically damped oil trough. As there are strict requirements for reducing the noise emission from internal combustion engines, according to the invention it is proposed that the oil trough should be surrounded by an outer trough, where the outer trough is made of plastic or sheet steel in one or more layers. To avoid noise bridges, the oil trough and outer trough are separated by elastomer elements. The outer trough achieves a reasonably priced increase in sound insulation. It is also possible to backfit an outer trough on engines.

  7. Radiometric evidence of Middle Devonian inversion of the Hill End Trough, northeast Lachlan Fold Belt

    International Nuclear Information System (INIS)

    Pakham, G.H.

    1999-01-01

    The publication of a new geological time-scale by the Australian Geological Survey Organisation and radiometric dates from the Hill End goldfield have prompted the re-examination of the timing of deformation of the Hill End Trough to determine whether it occurred in Middle Devonian or Early Carboniferous time. Palaeontological evidence from the western trough margin and the Capertee High dates the end of deposition in the trough as late Emsian or early Eifelian (385-382 Ma). After a mid-Devonian hiatus of at least 15 million years, paralic sedimentation commenced on the Molong and Capertee Highs in late Frasnian or early Famennian time (367-363 Ma). No Upper Devonian sedimentary formations occur in the Hill End Trough. Structural relationships indicate that the oldest mineral veins at Hill End preceded cleavage formation in the deformed trough sedimentary rocks. Early vein muscovites have Middle Devonian 40 Ar/ 39 Ar dates of 380-370 Ma. Regional metamorphic biotites from Hill End have well constrained 40 Ar/ 39 Ar closing ages of 360-358 Ma (mid-Famennian). The metamorphic (thermal) maximum which outlasted penetrative deformation. is estimated here by modelling to have been about 370 Ma (latest Givetian). This clearly places the earlier main deformation in the Middle Devonian. Deformation probably began by terminating trough deposition in latest Emsian to early Eifelian time and ended in early Givetian time at about 375 Ma ago. Published pressure and temperature data from the Hill End goldfield suggest that deformation thickened the 6 km sediment column to around 11 km. The thermal model suggests there was post-deformation erosion of about 4km and little if any further erosion occurred during Late Devonian to Early Carboniferous time. The shortening accompanying the inversion of the northern Hill End Trough may have been taken up in the region to the south, both east and west of the Copperhannia Thrust, and east of the southern termination of the Capertee High

  8. Influence of Learning Styles on Social Structures in Online Learning Environments

    Science.gov (United States)

    Cela, Karina; Sicilia, Miguel-Ángel; Sánchez-Alonso, Salvador

    2016-01-01

    In e-learning settings, the interactions of students with one another, with the course content and with the instructors generate a considerable amount of information that may be useful for understanding how people learn online. The objective of the present research was to use social network analysis to explore the social structure of an e-learning…

  9. Structure identification in fuzzy inference using reinforcement learning

    Science.gov (United States)

    Berenji, Hamid R.; Khedkar, Pratap

    1993-01-01

    In our previous work on the GARIC architecture, we have shown that the system can start with surface structure of the knowledge base (i.e., the linguistic expression of the rules) and learn the deep structure (i.e., the fuzzy membership functions of the labels used in the rules) by using reinforcement learning. Assuming the surface structure, GARIC refines the fuzzy membership functions used in the consequents of the rules using a gradient descent procedure. This hybrid fuzzy logic and reinforcement learning approach can learn to balance a cart-pole system and to backup a truck to its docking location after a few trials. In this paper, we discuss how to do structure identification using reinforcement learning in fuzzy inference systems. This involves identifying both surface as well as deep structure of the knowledge base. The term set of fuzzy linguistic labels used in describing the values of each control variable must be derived. In this process, splitting a label refers to creating new labels which are more granular than the original label and merging two labels creates a more general label. Splitting and merging of labels directly transform the structure of the action selection network used in GARIC by increasing or decreasing the number of hidden layer nodes.

  10. Using Learning Trajectories for Teacher Learning to Structure Professional Development

    Science.gov (United States)

    Bargagliotti, Anna E.; Anderson, Celia Rousseau

    2017-01-01

    As a result of the increased focus on data literacy and data science across the world, there has been a large demand for professional development in statistics. However, exactly how these professional development opportunities should be structured remains an open question. The purpose of this paper is to describe the first iteration of a design…

  11. Robust visual tracking via structured multi-task sparse learning

    KAUST Repository

    Zhang, Tianzhu; Ghanem, Bernard; Liu, Si; Ahuja, Narendra

    2012-01-01

    In this paper, we formulate object tracking in a particle filter framework as a structured multi-task sparse learning problem, which we denote as Structured Multi-Task Tracking (S-MTT). Since we model particles as linear combinations of dictionary

  12. Structural Identification and Comparison of Intelligent Mobile Learning Environment

    Science.gov (United States)

    Upadhyay, Nitin; Agarwal, Vishnu Prakash

    2007-01-01

    This paper proposes a methodology using graph theory, matrix algebra and permanent function to compare different architecture (structure) design of intelligent mobile learning environment. The current work deals with the development/selection of optimum architecture (structural) model of iMLE. This can be done using the criterion as discussed in…

  13. Non-Gaussian Methods for Causal Structure Learning.

    Science.gov (United States)

    Shimizu, Shohei

    2018-05-22

    Causal structure learning is one of the most exciting new topics in the fields of machine learning and statistics. In many empirical sciences including prevention science, the causal mechanisms underlying various phenomena need to be studied. Nevertheless, in many cases, classical methods for causal structure learning are not capable of estimating the causal structure of variables. This is because it explicitly or implicitly assumes Gaussianity of data and typically utilizes only the covariance structure. In many applications, however, non-Gaussian data are often obtained, which means that more information may be contained in the data distribution than the covariance matrix is capable of containing. Thus, many new methods have recently been proposed for using the non-Gaussian structure of data and inferring the causal structure of variables. This paper introduces prevention scientists to such causal structure learning methods, particularly those based on the linear, non-Gaussian, acyclic model known as LiNGAM. These non-Gaussian data analysis tools can fully estimate the underlying causal structures of variables under assumptions even in the presence of unobserved common causes. This feature is in contrast to other approaches. A simulated example is also provided.

  14. The Role of Structure in Learning Non-Euclidean Geometry

    Science.gov (United States)

    Asmuth, Jennifer A.

    2009-01-01

    How do people learn novel mathematical information that contradicts prior knowledge? The focus of this thesis is the role of structure in the acquisition of knowledge about hyperbolic geometry, a non-Euclidean geometry. In a series of three experiments, I contrast a more holistic structure--training based on closed figures--with a mathematically…

  15. Structure Learning and Statistical Estimation in Distribution Networks - Part II

    Energy Technology Data Exchange (ETDEWEB)

    Deka, Deepjyoti [Univ. of Texas, Austin, TX (United States); Backhaus, Scott N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chertkov, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-13

    Limited placement of real-time monitoring devices in the distribution grid, recent trends notwithstanding, has prevented the easy implementation of demand-response and other smart grid applications. Part I of this paper discusses the problem of learning the operational structure of the grid from nodal voltage measurements. In this work (Part II), the learning of the operational radial structure is coupled with the problem of estimating nodal consumption statistics and inferring the line parameters in the grid. Based on a Linear-Coupled(LC) approximation of AC power flows equations, polynomial time algorithms are designed to identify the structure and estimate nodal load characteristics and/or line parameters in the grid using the available nodal voltage measurements. Then the structure learning algorithm is extended to cases with missing data, where available observations are limited to a fraction of the grid nodes. The efficacy of the presented algorithms are demonstrated through simulations on several distribution test cases.

  16. A point focusing double parabolic trough concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Murphree, Quincy C. [Kentucky Mountain Bible College, Vancleve, KY (United States)

    2001-07-01

    This article shows that a point focusing solar concentrator can be made from two reflective parabolic troughs, a primary and a secondary, by orienting their longitudinal axes in perpendicular directions and separating them by the difference of their focal lengths along the optical axis. This offers a new alternative to the conventional 3-D paraboloidal concentrator permitting more flexibility in designs for applications requiring high concentrations. Both advantages and disadvantages are discussed. The intensity concentration ratio distribution is calculated in the focal plane and has elliptically shaped contours due to the inherent compensation of errant rays by the concave secondary. The ratio of the major to minor axes was 2.61 for the case considered, resulting in a concentration {approx}2.61 times that of a comparable concentrator without the compensation afforded by a concave secondary. Still, geometrical constraints limit the concentration to about 2000 suns for mirror quality errors of 5 mr. Optimisation of the compensation effect holds potential for improved performance for other concentrator designs. Finally, the functional dependence of the peak concentration and shading factor upon design parameters are presented. (Author)

  17. Parabolic Trough Solar Collector Initial Trials

    Directory of Open Access Journals (Sweden)

    Ghalya Pikra

    2012-03-01

    Full Text Available This paper discusses initial trials of parabolic trough solar collector (PTSC in Bandung. PTSC model consists of concentrator, absorber and tracking system. Concentrator designs are made with 2m aperture width, 6m length and 0.75m focal distance. The design is equipped with an automatic tracking system which is driven using 12V and 24Watt DC motor with 0.0125rpm rotational speed. Absorber/receiver is designed with evacuated tube type, with 1 inch core diameter and tube made of AISI304 and coated with black oxide, the outer tube is borosilicate glass with a 70 mm diameter and 1.5 m length. Working fluid stored in single type of thermal storage tank, a single phase with 37.7 liter volume. PTSC model testing carried out for 2 hours and 10 minutes produces heat output and input of 11.5 kW and 0.64 kW respectively. 

  18. Structure of Small World Innovation Network and Learning Performance

    Directory of Open Access Journals (Sweden)

    Shuang Song

    2014-01-01

    Full Text Available This paper examines the differences of learning performance of 5 MNCs (multinational corporations that filed the largest number of patents in China. We establish the innovation network with the patent coauthorship data by these 5 MNCs and classify the networks by the tail of distribution curve of connections. To make a comparison of the learning performance of these 5 MNCs with differing network structures, we develop an organization learning model by regarding the reality as having m dimensions, which denotes the heterogeneous knowledge about the reality. We further set n innovative individuals that are mutually interactive and own unique knowledge about the reality. A longer (shorter distance between the knowledge of the individual and the reality denotes a lower (higher knowledge level of that individual. Individuals interact with and learn from each other within the small-world network. By making 1,000 numerical simulations and averaging the simulated results, we find that the differing structure of the small-world network leads to the differences of learning performance between these 5 MNCs. The network monopolization negatively impacts and network connectivity positively impacts learning performance. Policy implications in the conclusion section suggest that to improve firm learning performance, it is necessary to establish a flat and connective network.

  19. Technical Manual for the SAM Physical Trough Model

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, M. J.; Gilman, P.

    2011-06-01

    NREL, in conjunction with Sandia National Lab and the U.S Department of Energy, developed the System Advisor Model (SAM) analysis tool for renewable energy system performance and economic analysis. This paper documents the technical background and engineering formulation for one of SAM's two parabolic trough system models in SAM. The Physical Trough model calculates performance relationships based on physical first principles where possible, allowing the modeler to predict electricity production for a wider range of component geometries than is possible in the Empirical Trough model. This document describes the major parabolic trough plant subsystems in detail including the solar field, power block, thermal storage, piping, auxiliary heating, and control systems. This model makes use of both existing subsystem performance modeling approaches, and new approaches developed specifically for SAM.

  20. Floor cooler for floor trough of a nuclear reactor

    International Nuclear Information System (INIS)

    Friedrich, H.J.

    1985-01-01

    Cooling pipes are situated below the floor trough of a BWR, which are connected to the annular distribution or collection pipes. The distribution and collection pipes are connected by parallel hairpin pipes with involute shape to the centre of the floor trough. These hairpin pipes are situated in a lower plane than the annular distribution pipe to the centre and in a higher plane from the centre to the outer annular collector pipe. (orig./HP) [de

  1. Learning and structure of neuronal networks

    Indian Academy of Sciences (India)

    structures, protein–protein interaction networks, social interactions, the Internet, and so on can be described by complex networks [1–5]. Recent developments in the understanding of complex networks has led to deeper insights about their origin and other properties [1–5]. One common realization that emerges from these ...

  2. Learning the Semantics of Structured Data Sources

    Science.gov (United States)

    Taheriyan, Mohsen

    2015-01-01

    Information sources such as relational databases, spreadsheets, XML, JSON, and Web APIs contain a tremendous amount of structured data, however, they rarely provide a semantic model to describe their contents. Semantic models of data sources capture the intended meaning of data sources by mapping them to the concepts and relationships defined by a…

  3. Bifurcation of learning and structure formation in neuronal maps

    DEFF Research Database (Denmark)

    Marschler, Christian; Faust-Ellsässer, Carmen; Starke, Jens

    2014-01-01

    to map formation in the laminar nucleus of the barn owl's auditory system. Using equation-free methods, we perform a bifurcation analysis of spatio-temporal structure formation in the associated synaptic-weight matrix. This enables us to analyze learning as a bifurcation process and follow the unstable...... states as well. A simple time translation of the learning window function shifts the bifurcation point of structure formation and goes along with traveling waves in the map, without changing the animal's sound localization performance....

  4. Climatology of the autumn Red Sea trough

    Science.gov (United States)

    Awad, Adel M.; Mashat, Abdul-Wahab S.

    2018-03-01

    In this study, the Sudan low and the associated Red Sea trough (RST) are objectively identified using the mean sea level pressure (SLP) data from the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis dataset covering the period 1955-2015. The Sudan low was detected in approximately 60.6% of the autumn periods, and approximately 83% of the detected low-pressure systems extended into RSTs, with most generated at night and during cold months. The distribution of the RSTs demonstrated that Sudan, South Sudan and Red Sea are the primary development areas of the RSTs, generating 97% of the RSTs in the study period. In addition, the outermost areas affected by RSTs, which include the southern, central and northern Red Sea areas, received approximately 91% of the RSTs originating from the primary generation areas. The synoptic features indicated that a Sudan low developed into an RST when the Sudan low deepened in the atmosphere, while the low pressures over the southern Arabian Peninsula are shallow and the anticyclonic systems are weakened over the northern Red Sea. Moreover, stabile areas over Africa and Arabian Peninsula form a high stability gradient around the Red Sea and the upper maximum winds weaken. The results of the case studies indicate that RSTs extend northward when the upper cyclonic and anticyclonic systems form a high geopotential gradient over Arabian Peninsula. Furthermore, the RST is oriented from the west to the east when the Azores high extends eastward and the Siberian high shrinks eastward or shifts northward.

  5. The De Long Trough: a newly discovered glacial trough on the East Siberian continental margin

    Directory of Open Access Journals (Sweden)

    M. O'Regan

    2017-09-01

    Full Text Available Ice sheets extending over parts of the East Siberian continental shelf have been proposed for the last glacial period and during the larger Pleistocene glaciations. The sparse data available over this sector of the Arctic Ocean have left the timing, extent and even existence of these ice sheets largely unresolved. Here we present new geophysical mapping and sediment coring data from the East Siberian shelf and slope collected during the 2014 SWERUS-C3 expedition (SWERUS-C3: Swedish – Russian – US Arctic Ocean Investigation of Climate-Cryosphere-Carbon Interactions. The multibeam bathymetry and chirp sub-bottom profiles reveal a set of glacial landforms that include grounding zone formations along the outer continental shelf, seaward of which lies a  >  65 m thick sequence of glacio-genic debris flows. The glacial landforms are interpreted to lie at the seaward end of a glacial trough – the first to be reported on the East Siberian margin, here referred to as the De Long Trough because of its location due north of the De Long Islands. Stratigraphy and dating of sediment cores show that a drape of acoustically laminated sediments covering the glacial deposits is older than ∼ 50 cal kyr BP. This provides direct evidence for extensive glacial activity on the Siberian shelf that predates the Last Glacial Maximum and most likely occurred during the Saalian (Marine Isotope Stage (MIS 6.

  6. Weak Lensing by Galaxy Troughs in DES Science Verification Data

    Energy Technology Data Exchange (ETDEWEB)

    Gruen, D. [Ludwig Maximilian Univ., Munich (Germany); Max Planck Inst. for Extraterrestrial Physics, Garching (Germany). et al.

    2015-09-29

    We measure the weak lensing shear around galaxy troughs, i.e. the radial alignment of background galaxies relative to underdensities in projections of the foreground galaxy field over a wide range of redshift in Science Verification data from the Dark Energy Survey. Our detection of the shear signal is highly significant (10σ–15σ for the smallest angular scales) for troughs with the redshift range z ϵ [0.2, 0.5] of the projected galaxy field and angular diameters of 10 arcmin…1°. These measurements probe the connection between the galaxy, matter density, and convergence fields. By assuming galaxies are biased tracers of the matter density with Poissonian noise, we find agreement of our measurements with predictions in a fiducial Λ cold dark matter model. Furthermore, the prediction for the lensing signal on large trough scales is virtually independent of the details of the underlying model for the connection of galaxies and matter. Our comparison of the shear around troughs with that around cylinders with large galaxy counts is consistent with a symmetry between galaxy and matter over- and underdensities. In addition, we measure the two-point angular correlation of troughs with galaxies which, in contrast to the lensing signal, is sensitive to galaxy bias on all scales. Finally, the lensing signal of troughs and their clustering with galaxies is therefore a promising probe of the statistical properties of matter underdensities and their connection to the galaxy field.

  7. Influence of Perceptual Saliency Hierarchy on Learning of Language Structures: An Artificial Language Learning Experiment.

    Science.gov (United States)

    Gong, Tao; Lam, Yau W; Shuai, Lan

    2016-01-01

    Psychological experiments have revealed that in normal visual perception of humans, color cues are more salient than shape cues, which are more salient than textural patterns. We carried out an artificial language learning experiment to study whether such perceptual saliency hierarchy (color > shape > texture) influences the learning of orders regulating adjectives of involved visual features in a manner either congruent (expressing a salient feature in a salient part of the form) or incongruent (expressing a salient feature in a less salient part of the form) with that hierarchy. Results showed that within a few rounds of learning participants could learn the compositional segments encoding the visual features and the order between them, generalize the learned knowledge to unseen instances with the same or different orders, and show learning biases for orders that are congruent with the perceptual saliency hierarchy. Although the learning performances for both the biased and unbiased orders became similar given more learning trials, our study confirms that this type of individual perceptual constraint could contribute to the structural configuration of language, and points out that such constraint, as well as other factors, could collectively affect the structural diversity in languages.

  8. The structure of observed learning outcome (SOLO) taxonomy: a model to promote dental students' learning.

    Science.gov (United States)

    Lucander, H; Bondemark, L; Brown, G; Knutsson, K

    2010-08-01

    Selective memorising of isolated facts or reproducing what is thought to be required - the surface approach to learning - is not the desired outcome for a dental student or a dentist in practice. The preferred outcome is a deep approach as defined by an intention to seek understanding, develop expertise and relate information and knowledge into a coherent whole. The aim of this study was to investigate whether the structure of observed learning outcome (SOLO) taxonomy could be used as a model to assist and promote the dental students to develop a deep approach to learning assessed as learning outcomes in a summative assessment. Thirty-two students, participating in course eight in 2007 at the Faculty of Odontology at Malmö University, were introduced to the SOLO taxonomy and constituted the test group. The control group consisted of 35 students participating in course eight in 2006. The effect of the introduction was measured by evaluating responses to a question in the summative assessment by using the SOLO taxonomy. The evaluators consisted of two teachers who performed the assessment of learning outcomes independently and separately on the coded material. The SOLO taxonomy as a model for learning was found to improve the quality of learning. Compared to the control group significantly more strings and structured relations between these strings were present in the test group after the SOLO taxonomy had been introduced (P SOLO taxonomy is recommended as a model for promoting and developing a deeper approach to learning in dentistry.

  9. Influence of Perceptual Saliency Hierarchy on Learning of Language Structures: An Artificial Language Learning Experiment

    Science.gov (United States)

    Gong, Tao; Lam, Yau W.; Shuai, Lan

    2016-01-01

    Psychological experiments have revealed that in normal visual perception of humans, color cues are more salient than shape cues, which are more salient than textural patterns. We carried out an artificial language learning experiment to study whether such perceptual saliency hierarchy (color > shape > texture) influences the learning of orders regulating adjectives of involved visual features in a manner either congruent (expressing a salient feature in a salient part of the form) or incongruent (expressing a salient feature in a less salient part of the form) with that hierarchy. Results showed that within a few rounds of learning participants could learn the compositional segments encoding the visual features and the order between them, generalize the learned knowledge to unseen instances with the same or different orders, and show learning biases for orders that are congruent with the perceptual saliency hierarchy. Although the learning performances for both the biased and unbiased orders became similar given more learning trials, our study confirms that this type of individual perceptual constraint could contribute to the structural configuration of language, and points out that such constraint, as well as other factors, could collectively affect the structural diversity in languages. PMID:28066281

  10. A Bayesian Approach for Structural Learning with Hidden Markov Models

    Directory of Open Access Journals (Sweden)

    Cen Li

    2002-01-01

    Full Text Available Hidden Markov Models(HMM have proved to be a successful modeling paradigm for dynamic and spatial processes in many domains, such as speech recognition, genomics, and general sequence alignment. Typically, in these applications, the model structures are predefined by domain experts. Therefore, the HMM learning problem focuses on the learning of the parameter values of the model to fit the given data sequences. However, when one considers other domains, such as, economics and physiology, model structure capturing the system dynamic behavior is not available. In order to successfully apply the HMM methodology in these domains, it is important that a mechanism is available for automatically deriving the model structure from the data. This paper presents a HMM learning procedure that simultaneously learns the model structure and the maximum likelihood parameter values of a HMM from data. The HMM model structures are derived based on the Bayesian model selection methodology. In addition, we introduce a new initialization procedure for HMM parameter value estimation based on the K-means clustering method. Experimental results with artificially generated data show the effectiveness of the approach.

  11. Developing an approach for teaching and learning about Lewis structures

    Science.gov (United States)

    Kaufmann, Ilana; Hamza, Karim M.; Rundgren, Carl-Johan; Eriksson, Lars

    2017-08-01

    This study explores first-year university students' reasoning as they learn to draw Lewis structures. We also present a theoretical account of the formal procedure commonly taught for drawing these structures. Students' discussions during problem-solving activities were video recorded and detailed analyses of the discussions were made through the use of practical epistemology analysis (PEA). Our results show that the formal procedure was central for drawing Lewis structures, but its use varied depending on situational aspects. Commonly, the use of individual steps of the formal procedure was contingent on experiences of chemical structures, and other information such as the characteristics of the problem given. The analysis revealed a number of patterns in how students constructed, checked and modified the structure in relation to the formal procedure and the situational aspects. We suggest that explicitly teaching the formal procedure as a process of constructing, checking and modifying might be helpful for students learning to draw Lewis structures. By doing so, the students may learn to check the accuracy of the generated structure not only in relation to the octet rule and formal charge, but also to other experiences that are not explicitly included in the formal procedure.

  12. Learning Orthographic Structure With Sequential Generative Neural Networks.

    Science.gov (United States)

    Testolin, Alberto; Stoianov, Ivilin; Sperduti, Alessandro; Zorzi, Marco

    2016-04-01

    Learning the structure of event sequences is a ubiquitous problem in cognition and particularly in language. One possible solution is to learn a probabilistic generative model of sequences that allows making predictions about upcoming events. Though appealing from a neurobiological standpoint, this approach is typically not pursued in connectionist modeling. Here, we investigated a sequential version of the restricted Boltzmann machine (RBM), a stochastic recurrent neural network that extracts high-order structure from sensory data through unsupervised generative learning and can encode contextual information in the form of internal, distributed representations. We assessed whether this type of network can extract the orthographic structure of English monosyllables by learning a generative model of the letter sequences forming a word training corpus. We show that the network learned an accurate probabilistic model of English graphotactics, which can be used to make predictions about the letter following a given context as well as to autonomously generate high-quality pseudowords. The model was compared to an extended version of simple recurrent networks, augmented with a stochastic process that allows autonomous generation of sequences, and to non-connectionist probabilistic models (n-grams and hidden Markov models). We conclude that sequential RBMs and stochastic simple recurrent networks are promising candidates for modeling cognition in the temporal domain. Copyright © 2015 Cognitive Science Society, Inc.

  13. Learning surface molecular structures via machine vision

    Science.gov (United States)

    Ziatdinov, Maxim; Maksov, Artem; Kalinin, Sergei V.

    2017-08-01

    Recent advances in high resolution scanning transmission electron and scanning probe microscopies have allowed researchers to perform measurements of materials structural parameters and functional properties in real space with a picometre precision. In many technologically relevant atomic and/or molecular systems, however, the information of interest is distributed spatially in a non-uniform manner and may have a complex multi-dimensional nature. One of the critical issues, therefore, lies in being able to accurately identify (`read out') all the individual building blocks in different atomic/molecular architectures, as well as more complex patterns that these blocks may form, on a scale of hundreds and thousands of individual atomic/molecular units. Here we employ machine vision to read and recognize complex molecular assemblies on surfaces. Specifically, we combine Markov random field model and convolutional neural networks to classify structural and rotational states of all individual building blocks in molecular assembly on the metallic surface visualized in high-resolution scanning tunneling microscopy measurements. We show how the obtained full decoding of the system allows us to directly construct a pair density function—a centerpiece in analysis of disorder-property relationship paradigm—as well as to analyze spatial correlations between multiple order parameters at the nanoscale, and elucidate reaction pathway involving molecular conformation changes. The method represents a significant shift in our way of analyzing atomic and/or molecular resolved microscopic images and can be applied to variety of other microscopic measurements of structural, electronic, and magnetic orders in different condensed matter systems.

  14. Structured brain computing and its learning

    International Nuclear Information System (INIS)

    Ae, Tadashi; Araki, Hiroyuki; Sakai, Keiichi

    1999-01-01

    We have proposed a two-level architecture for brain computing, where two levels are introduced for processing of meta-symbol. At level 1 a conventional pattern recognition is performed, where neural computation is included, and its output gives the meta-symbol which is a symbol enlarged from a symbol to a kind of pattern. At Level 2 an algorithm acquisition is made by using a machine for abstract states. We are also developing the VLSI chips at each level for SBC (Structured Brain Computer) Ver.1.0

  15. Use of deep seismic shooting to study graben-like troughs. [Urals

    Energy Technology Data Exchange (ETDEWEB)

    Makalovskiy, V.V.; Silayev, V.A.

    1983-01-01

    In the Southeast Perm Oblast, in the zone of articulation of the Russian platform and the Cisural trough, in order to study the structure of the graben-like troughs together with deep drilling, well seismic exploration is used by the method of deep seismic shooting (DSS). The DSS method developed by the Kamskiy department of the VNIGNI consists of blasting in the well shaft and recording of the elastic fluctuations on the Earth's surface. The use of the DSS made it possible to pinpoint structural details of the graben-like trough, and to clarify that this is in essence a zone of fracturing, where the lowered blocks alternated with elevated, and to establish the location and amplitude of the tectonic disorders. High geological information content, low labor intensity and rapidity of obtaining the results make it possible to recommend the DSS together with prospecting and exploratory drilling to study complexly constructed objects in order to reduce the number of unproductive wells.

  16. Structural learning in feedforward and feedback control.

    Science.gov (United States)

    Yousif, Nada; Diedrichsen, Jörn

    2012-11-01

    For smooth and efficient motor control, the brain needs to make fast corrections during the movement to resist possible perturbations. It also needs to adapt subsequent movements to improve future performance. It is important that both feedback corrections and feedforward adaptation need to be made based on noisy and often ambiguous sensory data. Therefore, the initial response of the motor system, both for online corrections and adaptive responses, is guided by prior assumptions about the likely structure of perturbations. In the context of correcting and adapting movements perturbed by a force field, we asked whether these priors are hard wired or whether they can be modified through repeated exposure to differently shaped force fields. We found that both feedback corrections to unexpected perturbations and feedforward adaptation to a new force field changed, such that they were appropriate to counteract the type of force field that participants had experienced previously. We then investigated whether these changes were driven by a common mechanism or by two separate mechanisms. Participants experienced force fields that were either temporally consistent, causing sustained adaptation, or temporally inconsistent, causing little overall adaptation. We found that the consistent force fields modified both feedback and feedforward responses. In contrast, the inconsistent force field modified the temporal shape of feedback corrections but not of the feedforward adaptive response. These results indicate that responses to force perturbations can be modified in a structural manner and that these modifications are at least partly dissociable for feedback and feedforward control.

  17. Main ionospheric trough in the daytime sector studied on the basis of vertical sounding data

    Energy Technology Data Exchange (ETDEWEB)

    Benkova, N.P.; Kozlov, E.F.; Mozhaev, A.M.; Osipov, N.K.; Samorokin, N.I.

    1980-09-01

    Data for 1969-1973 are used to study the displacement of the main ionospheric trough during daytime magnetic storms. The depth of the trough and electron density gradients on the sides of the trough are determined. The trough is found to move in a southeasterly direction during daytime storms. The results agree with theoretical conclusions that explain the formation of the trough by the collective transport of ionospheric plasma in a sunward direction.

  18. Structured Kernel Subspace Learning for Autonomous Robot Navigation.

    Science.gov (United States)

    Kim, Eunwoo; Choi, Sungjoon; Oh, Songhwai

    2018-02-14

    This paper considers two important problems for autonomous robot navigation in a dynamic environment, where the goal is to predict pedestrian motion and control a robot with the prediction for safe navigation. While there are several methods for predicting the motion of a pedestrian and controlling a robot to avoid incoming pedestrians, it is still difficult to safely navigate in a dynamic environment due to challenges, such as the varying quality and complexity of training data with unwanted noises. This paper addresses these challenges simultaneously by proposing a robust kernel subspace learning algorithm based on the recent advances in nuclear-norm and l 1 -norm minimization. We model the motion of a pedestrian and the robot controller using Gaussian processes. The proposed method efficiently approximates a kernel matrix used in Gaussian process regression by learning low-rank structured matrix (with symmetric positive semi-definiteness) to find an orthogonal basis, which eliminates the effects of erroneous and inconsistent data. Based on structured kernel subspace learning, we propose a robust motion model and motion controller for safe navigation in dynamic environments. We evaluate the proposed robust kernel learning in various tasks, including regression, motion prediction, and motion control problems, and demonstrate that the proposed learning-based systems are robust against outliers and outperform existing regression and navigation methods.

  19. Learning Spatiotemporally Encoded Pattern Transformations in Structured Spiking Neural Networks.

    Science.gov (United States)

    Gardner, Brian; Sporea, Ioana; Grüning, André

    2015-12-01

    Information encoding in the nervous system is supported through the precise spike timings of neurons; however, an understanding of the underlying processes by which such representations are formed in the first place remains an open question. Here we examine how multilayered networks of spiking neurons can learn to encode for input patterns using a fully temporal coding scheme. To this end, we introduce a new supervised learning rule, MultilayerSpiker, that can train spiking networks containing hidden layer neurons to perform transformations between spatiotemporal input and output spike patterns. The performance of the proposed learning rule is demonstrated in terms of the number of pattern mappings it can learn, the complexity of network structures it can be used on, and its classification accuracy when using multispike-based encodings. In particular, the learning rule displays robustness against input noise and can generalize well on an example data set. Our approach contributes to both a systematic understanding of how computations might take place in the nervous system and a learning rule that displays strong technical capability.

  20. Airport Flight Departure Delay Model on Improved BN Structure Learning

    Science.gov (United States)

    Cao, Weidong; Fang, Xiangnong

    An high score prior genetic simulated annealing Bayesian network structure learning algorithm (HSPGSA) by combining genetic algorithm(GA) with simulated annealing algorithm(SAA) is developed. The new algorithm provides not only with strong global search capability of GA, but also with strong local hill climb search capability of SAA. The structure with the highest score is prior selected. In the mean time, structures with lower score are also could be choice. It can avoid efficiently prematurity problem by higher score individual wrong direct growing population. Algorithm is applied to flight departure delays analysis in a large hub airport. Based on the flight data a BN model is created. Experiments show that parameters learning can reflect departure delay.

  1. Structural Relationships among Self-Regulated Learning, Learning Flow, Satisfaction, and Learning Persistence in Cyber Universities

    Science.gov (United States)

    Joo, Young Ju; Joung, Sunyoung; Kim, Jiyeon

    2014-01-01

    Learning persistence in a cyber-learning environment is not only an index determining the success or failure of individual learners but also a source of important information to establish the management direction of educational programs in an organization. Accordingly, learners need to be motivated to continue to grow in order to ensure both…

  2. Cascade system using both trough system and dish system for power generation

    International Nuclear Information System (INIS)

    Zhang, Cheng; Zhang, Yanping; Arauzo, Inmaculada; Gao, Wei; Zou, Chongzhe

    2017-01-01

    Highlights: • A novel solar cascade system using both trough and dish collectors is proposed. • Heat rejected by the Stirling engines is collected by the condensed water. • The directions to increase the efficiency improvement has been pointed out • Influence of flow type of heating/cooling fluids of Stirling engines is considered. - Abstract: This paper represents a novel solar thermal cascade system using both trough and dish systems for power generation. An effective structure using the condensed fluid of Rankine cycle to cool the Stirling engines to use the heat released by Stirling engines was proposed. The cascade system model with different fluid circuits was developed. The models of some important components of the system, such as dish collector, trough collector and Stirling engine array, are presented with detail explanation in this paper. Corresponding stand-alone systems were also developed for comparison. Simulations were conducted with the models to find out efficiency difference between cascade system and corresponding stand-alone systems. The directions to increase the efficiency difference were also considered. Results show that the cascade system can achieve a higher efficiency with a high solar irradiance (>550 W/m"2). The flow type of fluids between heating and cooling Stirling engine array is also required to concern on designing a cascade system with Stirling engine array.

  3. Implicit Structured Sequence Learning: An FMRI Study of the Structural Mere-Exposure Effect

    OpenAIRE

    Vasiliki eFolia; Vasiliki eFolia; Karl Magnus ePetersson; Karl Magnus ePetersson; Karl Magnus ePetersson

    2014-01-01

    In this event-related FMRI study we investigated the effect of five days of implicit acquisition on preference classification by means of an artificial grammar learning (AGL) paradigm based on the structural mere-exposure effect and preference classification using a simple right-linear unification grammar. This allowed us to investigate implicit AGL in a proper learning design by including baseline measurements prior to grammar exposure. After 5 days of implicit acquisition, the FMRI results ...

  4. Federal technology alert. Parabolic-trough solar water heating

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    Parabolic-trough solar water heating is a well-proven renewable energy technology with considerable potential for application at Federal facilities. For the US, parabolic-trough water-heating systems are most cost effective in the Southwest where direct solar radiation is high. Jails, hospitals, barracks, and other facilities that consistently use large volumes of hot water are particularly good candidates, as are facilities with central plants for district heating. As with any renewable energy or energy efficiency technology requiring significant initial capital investment, the primary condition that will make a parabolic-trough system economically viable is if it is replacing expensive conventional water heating. In combination with absorption cooling systems, parabolic-trough collectors can also be used for air-conditioning. Industrial Solar Technology (IST) of Golden, Colorado, is the sole current manufacturer of parabolic-trough solar water heating systems. IST has an Indefinite Delivery/Indefinite Quantity (IDIQ) contract with the Federal Energy Management Program (FEMP) of the US Department of Energy (DOE) to finance and install parabolic-trough solar water heating on an Energy Savings Performance Contract (ESPC) basis for any Federal facility that requests it and for which it proves viable. For an ESPC project, the facility does not pay for design, capital equipment, or installation. Instead, it pays only for guaranteed energy savings. Preparing and implementing delivery or task orders against the IDIQ is much simpler than the standard procurement process. This Federal Technology Alert (FTA) of the New Technology Demonstration Program is one of a series of guides to renewable energy and new energy-efficient technologies.

  5. Self-learning health monitoring algorithm in composite structures

    Science.gov (United States)

    Grassia, Luigi; Iannone, Michele; Califano, America; D'Amore, Alberto

    2018-02-01

    The paper describes a system that it is able of monitoring the health state of a composite structure in real time. The hardware of the system consists of a wire of strain sensors connected to a control unit. The software of the system elaborates the strain data and in real time is able to detect the presence of an eventual damage of the structures monitored with the strain sensors. The algorithm requires as input only the strains of the monitored structured measured on real time, i.e. those strains coming from the deformations of the composite structure due to the working loads. The health monitoring system does not require any additional device to interrogate the structure as often used in the literature, instead it is based on a self-learning procedure. The strain data acquired when the structure is healthy are used to set up the correlations between the strain in different positions of structure by means of neural network. Once the correlations between the strains in different position have been set up, these correlations act as a fingerprint of the healthy structure. In case of damage the correlation between the strains in the position of the structure near the damage will change due to the change of the stiffness of the structure caused by the damage. The developed software is able to recognize the change of the transfer function between the strains and consequently is able to detect the damage.

  6. Tracking local control of a parabolic trough collector

    International Nuclear Information System (INIS)

    Ajona, J.I.; Alberdi, J.; Gamero, E.; Blanco, J.

    1992-01-01

    In the local control, the sun position related to the trough collector is measured by two photo-resistors. The provided electronic signal is then compared with reference levels in order to get a set of B logical signals which form a byte. This byte and the commands issued by a programmable controller are connected to the inputs of o P.R.O.M. memory which is programmed with the logical equations of the control system. The memory output lines give the control command of the parabolic trough collector motor. (Author)

  7. Structure Learning of Linear Bayesian Networks in High-Dimensions

    OpenAIRE

    Aragam, Nikhyl Bryon

    2015-01-01

    Research into graphical models is a rapidly developing enterprise, garnering significant interest from both the statistics and machine learning communities. A parallel thread in both communities has been the study of low-dimensional structures in high-dimensional models where $p\\gg n$. Recently, there has been a surge of interest in connecting these threads in order to understand the behaviour of graphical models in high-dimensions. Due to their relative simplicity, undirected models such as ...

  8. Structured Kernel Dictionary Learning with Correlation Constraint for Object Recognition.

    Science.gov (United States)

    Wang, Zhengjue; Wang, Yinghua; Liu, Hongwei; Zhang, Hao

    2017-06-21

    In this paper, we propose a new discriminative non-linear dictionary learning approach, called correlation constrained structured kernel KSVD, for object recognition. The objective function for dictionary learning contains a reconstructive term and a discriminative term. In the reconstructive term, signals are implicitly non-linearly mapped into a space, where a structured kernel dictionary, each sub-dictionary of which lies in the span of the mapped signals from the corresponding class, is established. In the discriminative term, by analyzing the classification mechanism, the correlation constraint is proposed in kernel form, constraining the correlations between different discriminative codes, and restricting the coefficient vectors to be transformed into a feature space, where the features are highly correlated inner-class and nearly independent between-classes. The objective function is optimized by the proposed structured kernel KSVD. During the classification stage, the specific form of the discriminative feature is needless to be known, while the inner product of the discriminative feature with kernel matrix embedded is available, and is suitable for a linear SVM classifier. Experimental results demonstrate that the proposed approach outperforms many state-of-the-art dictionary learning approaches for face, scene and synthetic aperture radar (SAR) vehicle target recognition.

  9. Parabolic-trough technology roadmap: A pathway for sustained commercial development and deployment of parabolic-trough technology

    International Nuclear Information System (INIS)

    David Kearney; Hank Price

    1999-01-01

    Technology roadmapping is a needs-driven technology planning process to help identify, select, and develop technology alternatives to satisfy a set of market needs. The DOE's Office of Power Technologies' Concentrating Solar Power (CSP) Program recently sponsored a technology roadmapping workshop for parabolic trough technology. The workshop was attended by an impressive cross section of industry and research experts. The goals of the workshop were to evaluate the market potential for trough power projects, develop a better understanding of the current state of the technology, and to develop a conceptual plan for advancing the state of parabolic trough technology. This report documents and extends the roadmap that was conceptually developed during the workshop

  10. Seismic Reflectivity of the Crust in the Northern Salton Trough

    Science.gov (United States)

    Bauer, K.; Fuis, G. S.; Goldman, M.; Persaud, P.; Ryberg, T.; Langenheim, V. E.; Scheirer, D. S.; Rymer, M. J.; Hole, J. A.; Stock, J. M.; Catchings, R.

    2015-12-01

    The Salton Trough in southern California is a tectonically active pull-apart basin that was formed by migrating step-overs between strike-slip faults, of which the San Andreas Fault (SAF) and the Imperial Fault are the current, northernmost examples. The Salton Seismic Imaging Project (SSIP) was undertaken to improve our knowledge of fault geometry and seismic velocities within the sedimentary basins and underlying crystalline crust around the SAF. Such data are useful as input for modeling scenarios of strong ground shaking in the surrounding high-population areas. We used pre-stack depth migration of line segments from shot gathers in several seismic profiles that were acquired in the northern part of the SSIP study area (Lines 4 - 7). Our migration approach can be considered as an infinite-frequency approximation of the Fresnel volume pre-stack depth migration method. We use line segments instead of the original waveform data. We demonstrate the method using synthetic data and analyze real data from Lines 4 - 7 to illustrate the relationship between distinct phases in the time domain and their resulting image at depth. We show both normal-moveout reflections from sub-horizontal interfaces and reverse-moveout reflections from steep interfaces, such as faults. Migrated images of dipping faults, such as the SAF and the Pinto Mountain Fault, are presented in this way. The SAF is imaged along Line 4, through the Mecca Hills, as a number of steeply dipping fault segments that collectively form a flower structure, above 5 km depth, that sole into a moderately NE-dipping fault below that depth. The individual migrated reflection packages correlate with mapped surface fault traces in the Mecca Hills. A similar geometry is seen on Line 6, from Palm Springs through Yucca Valley, where fault splays sole or project into a moderately dipping SAF below 10-km depth. We also show and discuss the reflectivity pattern of the middle and lower crust for Lines 4 - 7.

  11. Older Australians: Structural barriers to learning in later life.

    Science.gov (United States)

    Boulton-Lewis, Gillian; Aird, Rosemary; Buys, Laurie

    2016-01-01

    Learning in older age is associated with benefits including increases in skills, social interactions, self-satisfaction, coping ability, enjoyment, and resilience to age-related changes in the brain. It is also a fundamental component of active ageing and if active ageing objectives are to be met for the growing ageing population, barriers to learning need to be understood and addressed. This study aimed at determining the degree that structural factors deter people aged 55 years and older from engaging in learning activities. The data were obtained from survey (n=421) with a purposive sample of Australian Seniors aged 55 to 75+, and open ended follow up interviews (n=40). The survey responses to the 22 barriers to learning questions were ranked and quantified. The issues identified in the interviews shed further light on the survey data. The analyses revealed that factors related to educational institutions as well as infrastructure were commonly cited as barriers to participation in learning. In particular expense of educational programmes (55.1%), long travelling time (45.6%) other transportation difficulties (38.9%), lack of interest in offered programmes ((36.4) and lack of information about courses (31.1%) were seen as barriers. The interviews revealed and confirmed five main barriers; money, offerings of interest/availability, travel/transport, information, computer skills and being employed. The findings should provide policy makers, institutions, organizations and government with a list of areas where changes might be made so as to improve older people's opportunities for learning as they proceed through older age.

  12. Exploring Unconventional Hydrocarbons in the Makó Trough, Pannonian basin, Hungary: Results and Challenges

    Science.gov (United States)

    Horvath, Anita; Bada, Gabor; Szafian, Peter; Sztano, Orsolya; Law, Ben; Wallis, Rod

    2010-05-01

    The latest phase exploration in the Makó Trough, which commenced a few years ago, has focused on the utilization of unconventional hydrocarbons. Accumulations are regarded as "unconventional" when they cannot be produced economically except by means of some sort of stimulation, usually hydraulic fracturing. The model we have developed for the evaluation of the hydrocarbon potential indicates a significant gas accumulation in the area of the Makó Trough. The tally of the distinctive attributes of the hydrocarbon system and the combined analysis of the available geological data led to the conclusion that the Makó Trough represents an area of active basin-centered gas accumulation (BCGA), with very significant perspective reserves. In a BCGA, hydrocarbons do not accumulate conventionally, in structural or stratigraphic traps, but rather in cells. Due to the geological setting of the Makó Trough, the hydrocarbon cell here forms a relatively continuous zone marked by considerable internal lithological and petrophysical variability. The most prolific parts, called sweet spots, possess a reservoir potential higher than the average. The identification of these sweet spots constitutes one of the most important, and quite possibly the most challenging task of the entire exploration project. The hemipelagic Endrőd Formation, which acts as the source rock, contains organic-rich marls in a depth delimited by the 170-230 °C isotherms. These marls constitute the still active hydrocarbon "kitchen" of the BCGA in the Makó Trough. The top and bottom boundaries of the cell essentially coincide with the turbidites of the Szolnok Formation and the top of the pre-Neogene basement, respectively. In light of the fact that pressure, temperature, and maturity tests have produced rather similar results in a number of wells in the area, we have reason to believe that the extension of the Makó Trough's BCGA is of regional dimensions (>1000 km2). The thickness and lateral extension of

  13. Robust visual tracking via structured multi-task sparse learning

    KAUST Repository

    Zhang, Tianzhu

    2012-11-09

    In this paper, we formulate object tracking in a particle filter framework as a structured multi-task sparse learning problem, which we denote as Structured Multi-Task Tracking (S-MTT). Since we model particles as linear combinations of dictionary templates that are updated dynamically, learning the representation of each particle is considered a single task in Multi-Task Tracking (MTT). By employing popular sparsity-inducing lp,q mixed norms (specifically p∈2,∞ and q=1), we regularize the representation problem to enforce joint sparsity and learn the particle representations together. As compared to previous methods that handle particles independently, our results demonstrate that mining the interdependencies between particles improves tracking performance and overall computational complexity. Interestingly, we show that the popular L1 tracker (Mei and Ling, IEEE Trans Pattern Anal Mach Intel 33(11):2259-2272, 2011) is a special case of our MTT formulation (denoted as the L11 tracker) when p=q=1. Under the MTT framework, some of the tasks (particle representations) are often more closely related and more likely to share common relevant covariates than other tasks. Therefore, we extend the MTT framework to take into account pairwise structural correlations between particles (e.g. spatial smoothness of representation) and denote the novel framework as S-MTT. The problem of learning the regularized sparse representation in MTT and S-MTT can be solved efficiently using an Accelerated Proximal Gradient (APG) method that yields a sequence of closed form updates. As such, S-MTT and MTT are computationally attractive. We test our proposed approach on challenging sequences involving heavy occlusion, drastic illumination changes, and large pose variations. Experimental results show that S-MTT is much better than MTT, and both methods consistently outperform state-of-the-art trackers. © 2012 Springer Science+Business Media New York.

  14. Large-Scale Unsupervised Hashing with Shared Structure Learning.

    Science.gov (United States)

    Liu, Xianglong; Mu, Yadong; Zhang, Danchen; Lang, Bo; Li, Xuelong

    2015-09-01

    Hashing methods are effective in generating compact binary signatures for images and videos. This paper addresses an important open issue in the literature, i.e., how to learn compact hash codes by enhancing the complementarity among different hash functions. Most of prior studies solve this problem either by adopting time-consuming sequential learning algorithms or by generating the hash functions which are subject to some deliberately-designed constraints (e.g., enforcing hash functions orthogonal to one another). We analyze the drawbacks of past works and propose a new solution to this problem. Our idea is to decompose the feature space into a subspace shared by all hash functions and its complementary subspace. On one hand, the shared subspace, corresponding to the common structure across different hash functions, conveys most relevant information for the hashing task. Similar to data de-noising, irrelevant information is explicitly suppressed during hash function generation. On the other hand, in case that the complementary subspace also contains useful information for specific hash functions, the final form of our proposed hashing scheme is a compromise between these two kinds of subspaces. To make hash functions not only preserve the local neighborhood structure but also capture the global cluster distribution of the whole data, an objective function incorporating spectral embedding loss, binary quantization loss, and shared subspace contribution is introduced to guide the hash function learning. We propose an efficient alternating optimization method to simultaneously learn both the shared structure and the hash functions. Experimental results on three well-known benchmarks CIFAR-10, NUS-WIDE, and a-TRECVID demonstrate that our approach significantly outperforms state-of-the-art hashing methods.

  15. Implicit Structured Sequence Learning: An FMRI Study of the Structural Mere-Exposure Effect

    Directory of Open Access Journals (Sweden)

    Vasiliki eFolia

    2014-02-01

    Full Text Available In this event-related FMRI study we investigated the effect of five days of implicit acquisition on preference classification by means of an artificial grammar learning (AGL paradigm based on the structural mere-exposure effect and preference classification using a simple right-linear unification grammar. This allowed us to investigate implicit AGL in a proper learning design by including baseline measurements prior to grammar exposure. After 5 days of implicit acquisition, the FMRI results showed activations in a network of brain regions including the inferior frontal (centered on BA 44/45 and the medial prefrontal regions (centered on BA 8/32. Importantly, and central to this study, the inclusion of a naive preference FMRI baseline measurement allowed us to conclude that these FMRI findings were the intrinsic outcomes of the learning process itself and not a reflection of a preexisting functionality recruited during classification, independent of acquisition. Support for the implicit nature of the knowledge utilized during preference classification on day 5 come from the fact that the basal ganglia, associated with implicit procedural learning, were activated during classification, while the medial temporal lobe system, associated with explicit declarative memory, was consistently deactivated. Thus, preference classification in combination with structural mere-exposure can be used to investigate structural sequence processing (syntax in unsupervised AGL paradigms with proper learning designs.

  16. Implicit structured sequence learning: an fMRI study of the structural mere-exposure effect.

    Science.gov (United States)

    Folia, Vasiliki; Petersson, Karl Magnus

    2014-01-01

    In this event-related fMRI study we investigated the effect of 5 days of implicit acquisition on preference classification by means of an artificial grammar learning (AGL) paradigm based on the structural mere-exposure effect and preference classification using a simple right-linear unification grammar. This allowed us to investigate implicit AGL in a proper learning design by including baseline measurements prior to grammar exposure. After 5 days of implicit acquisition, the fMRI results showed activations in a network of brain regions including the inferior frontal (centered on BA 44/45) and the medial prefrontal regions (centered on BA 8/32). Importantly, and central to this study, the inclusion of a naive preference fMRI baseline measurement allowed us to conclude that these fMRI findings were the intrinsic outcomes of the learning process itself and not a reflection of a preexisting functionality recruited during classification, independent of acquisition. Support for the implicit nature of the knowledge utilized during preference classification on day 5 come from the fact that the basal ganglia, associated with implicit procedural learning, were activated during classification, while the medial temporal lobe system, associated with explicit declarative memory, was consistently deactivated. Thus, preference classification in combination with structural mere-exposure can be used to investigate structural sequence processing (syntax) in unsupervised AGL paradigms with proper learning designs.

  17. Modeling, Simulation and Performance Evaluation of Parabolic Trough

    African Journals Online (AJOL)

    Mekuannint

    Mekuannint Mesfin and Abebayehu Assefa. Department of Mechanical Engineering. Addis Ababa University ... off design weather conditions as well. Keywords: Parabolic Trough Collector (PTC);. Heat Transfer ... of a conventional Rankine cycle power plant with solar fields that are used to increase the temperature of heat ...

  18. Modeling, Simulation and Performance Evaluation of Parabolic Trough

    African Journals Online (AJOL)

    Mekuannint

    Heat Transfer Fluid (HTF); TRNSYS power plant model; STEC library; Solar Advisor Model (SAM);. TRNSYS solar field model; Solar Electric. Generation System (SEGS). INTRODUCTION. Parabolic troughs are currently most used means of power generation option of solar sources. Solar electric generation systems (SEGs) ...

  19. Strawberry Production in Soilless Substrate Troughs – Plant Growth

    Science.gov (United States)

    Soilless substrates made of peat moss, coconut coir, perlite, rockwool or bark are pathogen free and they have been used in strawberry production in Europe in troughs or containers. Open field strawberry production in soilless substrate is new to California growers. The objective of this study was t...

  20. Optimized molten salt receivers for ultimate trough solar fields

    Science.gov (United States)

    Riffelmann, Klaus-J.; Richert, Timo; Kuckelkorn, Thomas

    2016-05-01

    Today parabolic trough collectors are the most successful concentrating solar power (CSP) technology. For the next development step new systems with increased operation temperature and new heat transfer fluids (HTF) are currently developed. Although the first power tower projects have successfully been realized, up to now there is no evidence of an all-dominant economic or technical advantage of power tower or parabolic trough. The development of parabolic trough technology towards higher performance and significant cost reduction have led to significant improvements in competitiveness. The use of molten salt instead of synthetic oil as heat transfer fluid will bring down the levelized costs of electricity (LCOE) even further while providing dispatchable energy with high capacity factors. FLABEG has developed the Ultimate TroughTM (UT) collector, jointly with sbp Sonne GmbH and supported by public funds. Due to its validated high optical accuracy, the collector is very suitable to operate efficiently at elevated temperatures up to 550 °C. SCHOTT will drive the key-innovations by introducing the 4th generation solar receiver that addresses the most significant performance and cost improvement measures. The new receivers have been completely redesigned to provide a product platform that is ready for high temperature operation up to 550 °C. Moreover distinct product features have been introduced to reduce costs and risks in solar field assembly and installation. The increased material and design challenges incurred with the high temperature operation have been reflected in sophisticated qualification and validation procedures.

  1. Parabolic Trough Solar Power for Competitive U.S. Markets

    International Nuclear Information System (INIS)

    Price, Henry W.

    1998-01-01

    Nine parabolic trough power plants located in the California Mojave Desert represent the only commercial development of large-scale solar power plants to date. Although all nine plants continue to operate today, no new solar power plants have been completed since 1990. Over the last several years, the parabolic trough industry has focused much of its efforts on international market opportunities. Although the power market in developing countries appears to offer a number of opportunities for parabolic trough technologies due to high growth and the availability of special financial incentives for renewables, these markets are also plagued with many difficulties for developers. In recent years, there has been some renewed interest in the U.S. domestic power market as a result of an emerging green market and green pricing incentives. Unfortunately, many of these market opportunities and incentives focus on smaller, more modular technologies (such as photovoltaics or wind power), and as a result they tend to exclude or are of minimum long-term benefit to large-scale concentrating solar power technologies. This paper looks at what is necessary for large-scale parabolic trough solar power plants to compete with state-of-the-art fossil power technology in a competitive U.S. power market

  2. Inversion tectonics of the benue trough | Mamah | Global Journal of ...

    African Journals Online (AJOL)

    Spreading was, however, arrested by the rotation of the hot spot plumes onto the shoulders of the trough such as unto the Cameroom volcanic line by a sequence of events including crustal thinning and doming, rifting and faulting, grabens and horst formation, volcanism and subsidence, imbricate sedimentation and ...

  3. Gas Turbine/Solar Parabolic Trough Hybrid Designs: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, C. S.; Ma, Z.; Erbes, M.

    2011-03-01

    A strength of parabolic trough concentrating solar power (CSP) plants is the ability to provide reliable power by incorporating either thermal energy storage or backup heat from fossil fuels. Yet these benefits have not been fully realized because thermal energy storage remains expensive at trough operating temperatures and gas usage in CSP plants is less efficient than in dedicated combined cycle plants. For example, while a modern combined cycle plant can achieve an overall efficiency in excess of 55%; auxiliary heaters in a parabolic trough plant convert gas to electricity at below 40%. Thus, one can argue the more effective use of natural gas is in a combined cycle plant, not as backup to a CSP plant. Integrated solar combined cycle (ISCC) systems avoid this pitfall by injecting solar steam into the fossil power cycle; however, these designs are limited to about 10% total solar enhancement. Without reliable, cost-effective energy storage or backup power, renewable sources will struggle to achieve a high penetration in the electric grid. This paper describes a novel gas turbine / parabolic trough hybrid design that combines solar contribution of 57% and higher with gas heat rates that rival that for combined cycle natural gas plants. The design integrates proven solar and fossil technologies, thereby offering high reliability and low financial risk while promoting deployment of solar thermal power.

  4. Tear trough – Anatomy and treatment by autologous fat grafting

    Directory of Open Access Journals (Sweden)

    Chang Yung Chia

    2016-07-01

    Full Text Available Tear trough is the main irregularity at midface, of which treatment is difficult. There is no agreement in literature about its anatomy and best treatment. The author presented an anatomical study and personal autologous fat grafting technique for tear trough treatment. Anatomical dissections were done on two fresh cadavers to examine the skin, subcutaneous, muscle and bone layers, spaces, and attachments. Safety and efficacy were evaluated via retrospective analysis of the last 200 consecutive procedures performed by the author. Tear trough is caused by the abrupt transition of the palpebral orbicular oculi muscle (OOM (i.e., thin skin without subcutaneous fat compartment to the orbital OOM (i.e., thicker skin with malar fat compartment. The tear trough region is located at the OOM bony origin at the medial canthus where no specific ligament was found. The grafted fat volume stabilized at two or three months after the procedure, instead of six months as stated in literature, with excellent results and no severe complications. Tear trough is a personal characteristic, a natural anatomical depression caused by subcutaneous irregularity and can worsen with age. The lack of volume is not effectively corrected by surgeries and thus it must be filled. Fat grafting has several advantages over alloplastic fillers, although it may be more difficult. Fat graft is autologous and abundant, and tissue transplantation could enhance skin quality. Fat grafting is a simple, safe, and effective solution for adding extra volume to correct the deflation phenomenon of the midface aging process. There is no specific anatomical plane for volume injection; the fat graft must be evenly distributed in the deep and superficial plane for uniformity.

  5. Structure prediction of boron-doped graphene by machine learning

    Science.gov (United States)

    M. Dieb, Thaer; Hou, Zhufeng; Tsuda, Koji

    2018-06-01

    Heteroatom doping has endowed graphene with manifold aspects of material properties and boosted its applications. The atomic structure determination of doped graphene is vital to understand its material properties. Motivated by the recently synthesized boron-doped graphene with relatively high concentration, here we employ machine learning methods to search the most stable structures of doped boron atoms in graphene, in conjunction with the atomistic simulations. From the determined stable structures, we find that in the free-standing pristine graphene, the doped boron atoms energetically prefer to substitute for the carbon atoms at different sublattice sites and that the para configuration of boron-boron pair is dominant in the cases of high boron concentrations. The boron doping can increase the work function of graphene by 0.7 eV for a boron content higher than 3.1%.

  6. Filopodia: A Rapid Structural Plasticity Substrate for Fast Learning

    Directory of Open Access Journals (Sweden)

    Ahmet S. Ozcan

    2017-06-01

    Full Text Available Formation of new synapses between neurons is an essential mechanism for learning and encoding memories. The vast majority of excitatory synapses occur on dendritic spines, therefore, the growth dynamics of spines is strongly related to the plasticity timescales. Especially in the early stages of the developing brain, there is an abundant number of long, thin and motile protrusions (i.e., filopodia, which develop in timescales of seconds and minutes. Because of their unique morphology and motility, it has been suggested that filopodia can have a dual role in both spinogenesis and environmental sampling of potential axonal partners. I propose that filopodia can lower the threshold and reduce the time to form new dendritic spines and synapses, providing a substrate for fast learning. Based on this proposition, the functional role of filopodia during brain development is discussed in relation to learning and memory. Specifically, it is hypothesized that the postnatal brain starts with a single-stage memory system with filopodia playing a significant role in rapid structural plasticity along with the stability provided by the mushroom-shaped spines. Following the maturation of the hippocampus, this highly-plastic unitary system transitions to a two-stage memory system, which consists of a plastic temporary store and a long-term stable store. In alignment with these architectural changes, it is posited that after brain maturation, filopodia-based structural plasticity will be preserved in specific areas, which are involved in fast learning (e.g., hippocampus in relation to episodic memory. These propositions aim to introduce a unifying framework for a diversity of phenomena in the brain such as synaptogenesis, pruning and memory consolidation.

  7. White matter structure changes as adults learn a second language.

    Science.gov (United States)

    Schlegel, Alexander A; Rudelson, Justin J; Tse, Peter U

    2012-08-01

    Traditional models hold that the plastic reorganization of brain structures occurs mainly during childhood and adolescence, leaving adults with limited means to learn new knowledge and skills. Research within the last decade has begun to overturn this belief, documenting changes in the brain's gray and white matter as healthy adults learn simple motor and cognitive skills [Lövdén, M., Bodammer, N. C., Kühn, S., Kaufmann, J., Schütze, H., Tempelmann, C., et al. Experience-dependent plasticity of white-matter microstructure extends into old age. Neuropsychologia, 48, 3878-3883, 2010; Taubert, M., Draganski, B., Anwander, A., Müller, K., Horstmann, A., Villringer, A., et al. Dynamic properties of human brain structure: Learning-related changes in cortical areas and associated fiber connections. The Journal of Neuroscience, 30, 11670-11677, 2010; Scholz, J., Klein, M. C., Behrens, T. E. J., & Johansen-Berg, H. Training induces changes in white-matter architecture. Nature Neuroscience, 12, 1370-1371, 2009; Draganski, B., Gaser, C., Busch, V., Schuirer, G., Bogdahn, U., & May, A. Changes in grey matter induced by training. Nature, 427, 311-312, 2004]. Although the significance of these changes is not fully understood, they reveal a brain that remains plastic well beyond early developmental periods. Here we investigate the role of adult structural plasticity in the complex, long-term learning process of foreign language acquisition. We collected monthly diffusion tensor imaging scans of 11 English speakers who took a 9-month intensive course in written and spoken Modern Standard Chinese as well as from 16 control participants who did not study a language. We show that white matter reorganizes progressively across multiple sites as adults study a new language. Language learners exhibited progressive changes in white matter tracts associated with traditional left hemisphere language areas and their right hemisphere analogs. Surprisingly, the most significant changes

  8. Structure Learning and Statistical Estimation in Distribution Networks - Part I

    Energy Technology Data Exchange (ETDEWEB)

    Deka, Deepjyoti [Univ. of Texas, Austin, TX (United States); Backhaus, Scott N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chertkov, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-13

    Traditionally power distribution networks are either not observable or only partially observable. This complicates development and implementation of new smart grid technologies, such as those related to demand response, outage detection and management, and improved load-monitoring. In this two part paper, inspired by proliferation of the metering technology, we discuss estimation problems in structurally loopy but operationally radial distribution grids from measurements, e.g. voltage data, which are either already available or can be made available with a relatively minor investment. In Part I, the objective is to learn the operational layout of the grid. Part II of this paper presents algorithms that estimate load statistics or line parameters in addition to learning the grid structure. Further, Part II discusses the problem of structure estimation for systems with incomplete measurement sets. Our newly suggested algorithms apply to a wide range of realistic scenarios. The algorithms are also computationally efficient – polynomial in time– which is proven theoretically and illustrated computationally on a number of test cases. The technique developed can be applied to detect line failures in real time as well as to understand the scope of possible adversarial attacks on the grid.

  9. The F-region trough: seasonal morphology and relation to interplanetary magnetic field

    Directory of Open Access Journals (Sweden)

    M. Voiculescu

    2006-03-01

    Full Text Available We present here the results of a statistical study of the ionospheric trough observed in 2003 by means of satellite tomography. We focus on the seasonal morphology of the trough occurrence and investigate the trough latitude, width and the horizontal gradients at the edges, at different magnetic local times, as well as their relations to geomagnetic activity and the interplanetary magnetic field. A seasonal effect is noticed in the diurnal variation of the trough latitude, indicating that summer clearly differs from the other seasons. In winter the troughs seem to follow the solar terminator. The width of the trough has a diurnal variation and it depends on the season, as well. The broadest troughs are observed in winter and the narrowest ones in summer. A discontinuity in the diurnal variation of the trough latitude is observed before noon. It is suggested that this is an indication of a difference between the generation mechanisms of morningside and eveningside troughs. The density gradients at the edges have a complex dependence on the latitude of the trough and on geomagnetic activity. The photoionization and the auroral precipitation are competing in the formation of the trough walls at different magnetic local times. An important finding is that the interplanetary magnetic field plays a role in the occurrence of the trough at different levels of geomagnetic activity. This is probably associated with the topology of the polar cap convection pattern, which depends on the directions of the IMF components By and Bz.

  10. Applying Adaptive Swarm Intelligence Technology with Structuration in Web-Based Collaborative Learning

    Science.gov (United States)

    Huang, Yueh-Min; Liu, Chien-Hung

    2009-01-01

    One of the key challenges in the promotion of web-based learning is the development of effective collaborative learning environments. We posit that the structuration process strongly influences the effectiveness of technology used in web-based collaborative learning activities. In this paper, we propose an ant swarm collaborative learning (ASCL)…

  11. Prospecting for a Blind Geothermal System Utilizing Geologic and Geophysical Data, Seven Troughs Range, Northwestern Nevada

    Science.gov (United States)

    Forson, Corina

    To aid in the discovery and evaluation of blind resources, it is important to utilize geologic, geophysical, and geochemical techniques to find the required elements (e.g., heat source, fluid to transport the heat, and permeability in a reservoir) for geothermal energy production. Based on a regional low resistivity anomaly discovered through a reconnaissance magnetotelluric (MT) survey, detailed geologic mapping, structural analysis, and a 2 m temperature survey were conducted to delineate the most likely areas for blind geothermal activity in the Seven Troughs Range, Nevada. The Seven Troughs Range resides in the northwestern Basin and Range province 190 km northeast of Reno and 50 km northwest of Lovelock in western Nevada. There is no known geothermal system in the area. Mesozoic metasedimentary strata and intrusions dominate the northern and southern parts of the range but are nonconformably overlain by a thick sequence (~ 1.5 km) of Oligocene to Miocene volcanic and volcaniclastic rocks and Quaternary sediments in the central part of the range. The southern part of the range consists of a basement horst block bounded by two major range-front faults, with Holocene fault scarps marking the more prominent fault on the east side of the range. In contrast, several gently to moderately west-tilted fault blocks, with good exposures of the Tertiary volcanic strata and bounded by a series of steeply east-dipping normal faults, characterize the central part of the range. Kinematic analysis of faults in the range and regional relations indicate a west-northwest-trending extension direction. Accordingly, slip and dilation tendency analyses suggest that north-northeast striking faults are the most favorably oriented for reactivation and fluid flow under the current stress field. Two areas in the Seven Troughs Range have a favorable structural setting for generating permeability and channeling geothermal fluids to the near surface: 1) A major right step in the range

  12. Morphotectonics of the central Muertos thrust belt and Muertos Trough (northeastern Caribbean)

    Science.gov (United States)

    Granja, Bruna J.L.; ten Brink, Uri S.; Carbó-Gorosabel, Andrés; Muñoz-Martín, A.; Gomez, Ballesteros M.

    2009-01-01

    Multibeam bathymetry data acquired during the 2005 Spanish R/V Hesp??rides cruise and reprocessed multichannel seismic profiles provide the basis for the analysis of the morphology and deformation in the central Muertos Trough and Muertos thrust belt. The Muertos Trough is an elongated basin developed where the Venezuelan Basin crust is thrusted under the Muertos fold-and-thrust belt. Structural variations along the Muertos Trough are suggested to be a consequence of the overburden of the asymmetrical thrust belt and by the variable nature of the Venezuelan Basin crust along the margin. The insular slope can be divided into three east-west trending slope provinces with high lateral variability which correspond to different accretion stages: 1) The lower slope is composed of an active sequence of imbricate thrust slices and closed fold axes, which form short and narrow accretionary ridges and elongated slope basins; 2) The middle slope shows a less active imbricate structure resulting in lower superficial deformation and bigger slope basins; 3) The upper slope comprises the talus region and extended terraces burying an island arc basement and an inactive imbricate structure. The talus region is characterized by a dense drainage network that transports turbidite flows from the islands and their surrounding carbonate platform areas to the slope basins and sometimes to the trough. In the survey area the accommodation of the ongoing east-west differential motion between the Hispaniola and the Puerto Rico-Virgin Islands blocks takes place by means of diffuse deformation. The asymmetrical development of the thrust belt is not related to the geological conditions in the foreland, but rather may be caused by variations in the geometry and movement of the backstop. The map-view curves of the thrust belt and the symmetry of the recesses suggest a main north-south convergence along the Muertos margin. The western end of the Investigator Fault Zone comprises a broad band of

  13. Paradoxes of Social Networking in a Structured Web 2.0 Language Learning Community

    Science.gov (United States)

    Loiseau, Mathieu; Zourou, Katerina

    2012-01-01

    This paper critically inquires into social networking as a set of mechanisms and associated practices developed in a structured Web 2.0 language learning community. This type of community can be roughly described as learning spaces featuring (more or less) structured language learning resources displaying at least some notions of language learning…

  14. The role of meltwater in high-latitude trough-mouth fan development : the Disko Trough-Mouth Fan, West Greenland.

    OpenAIRE

    Cofaigh, Colm Ó.; Hogan, Kelly A.; Jennings, Anne E.; Callard, S. Louise; Dowdeswell, Julian A.; Noormets, Riko; Evans, Jeff

    2018-01-01

    The Disko Trough-Mouth Fan (TMF) is a major submarine sediment fan located along the central west Greenland continental margin offshore of Disko Trough. The location of the TMF at the mouth of a prominent cross-shelf trough indicates that it is a product of repeated glacigenic sediment delivery from former fast-flowing outlets of the Greenland Ice Sheet, including an ancestral Jakobshavn Isbrae, which expanded to the shelf edge during successive glacial cycles. This study focuses on the upper...

  15. Structural damage detection using deep learning of ultrasonic guided waves

    Science.gov (United States)

    Melville, Joseph; Alguri, K. Supreet; Deemer, Chris; Harley, Joel B.

    2018-04-01

    Structural health monitoring using ultrasonic guided waves relies on accurate interpretation of guided wave propagation to distinguish damage state indicators. However, traditional physics based models do not provide an accurate representation, and classic data driven techniques, such as a support vector machine, are too simplistic to capture the complex nature of ultrasonic guide waves. To address this challenge, this paper uses a deep learning interpretation of ultrasonic guided waves to achieve fast, accurate, and automated structural damaged detection. To achieve this, full wavefield scans of thin metal plates are used, half from the undamaged state and half from the damaged state. This data is used to train our deep network to predict the damage state of a plate with 99.98% accuracy given signals from just 10 spatial locations on the plate, as compared to that of a support vector machine (SVM), which achieved a 62% accuracy.

  16. Classifying Structures in the ISM with Machine Learning Techniques

    Science.gov (United States)

    Beaumont, Christopher; Goodman, A. A.; Williams, J. P.

    2011-01-01

    The processes which govern molecular cloud evolution and star formation often sculpt structures in the ISM: filaments, pillars, shells, outflows, etc. Because of their morphological complexity, these objects are often identified manually. Manual classification has several disadvantages; the process is subjective, not easily reproducible, and does not scale well to handle increasingly large datasets. We have explored to what extent machine learning algorithms can be trained to autonomously identify specific morphological features in molecular cloud datasets. We show that the Support Vector Machine algorithm can successfully locate filaments and outflows blended with other emission structures. When the objects of interest are morphologically distinct from the surrounding emission, this autonomous classification achieves >90% accuracy. We have developed a set of IDL-based tools to apply this technique to other datasets.

  17. Managerial instrument for didactic staff structure optimization for Distance Learning

    Directory of Open Access Journals (Sweden)

    Gavrus Cristina

    2017-01-01

    Full Text Available Distance learning is a modern system for providing educational services and is relatively new in Romania, if related to the date of its emergence in Europe. More and more active working people are interested in this form of education, paying of course a special attention to its quality. It is quite difficult to appraise the quality of educational programs but several instruments and criteria have been developed over time. The present paper proposes an original mathematical instrument that is aiming at human resources, this type of resources being considered extremely important in case of providing educational service. The number of teachers is crucial for a distance learning program study, because the didactic staff must cover a number of didactic classes that take place on weekends. Concretely, this paper is focused on finding an algorithm that allows the didactic staff structure optimization. For accomplishing this objective, two managerial instruments were use. One of them is mathematical linear programing technique, that develops a mathematical model for didactic staff structure and the other one is WinQSB software package that tests the mathematical model.

  18. Teaching and Learning Structural Geology Using SketchUp

    Science.gov (United States)

    Rey, Patrice

    2017-04-01

    The books and maps we read, the posters we pin on our walls, the TV sets and computer monitors we spend hours watching, the white (or black) boards we use to teach, all reduce our world into planar images. As a result, and through years of oblivious practice, our brain is conditioned to understand the world in two dimensions (2D) only. As structural geologists, we know that the most challenging aspect of teaching and learning structural geology is that we need to be able to mentally manipulate 2D and three-dimensional (3D) objects. Although anyone can learn through practice the art of spatial visualisation, the fact remains that the initial stages of learning structural geology are for many students very challenging, as we naively use 2D images to teach 3D concepts. While interactive 3D holography is not far away, some inexpensive tools already exist allowing us to generate interactive computer images, the free rotation, scaling and manipulation of which can help students to quickly grasp the geometry and internal architecture of 3D objects. Recently, I have experimented with SketchUp (works on Mac and Windows). SketchUp was initially released in 2000 by @Last Software, as a 3D modelling tool for architects, designers and filmmakers. It was acquired by Google in 2006 to further the development of GoogleEarth. Google released SketchUp for free, and provided a portal named 3D Warehouse for users to share their models. Google sold SketchUp to Trimble Navigation in 2012, which added Extension Warehouse for users to distribute add-ons. SketchUp models can be exported in a number of formats including .dae (digital asset exchange) useful to embed interactive 3D models into iBooks and html5 documents, and .kmz (keyhole markup language zipped) to embed interactive 3D models and cross-sections into GoogleEarth. SketchUp models can be exported into 3D pdf through the add-on SimLab, and .stl for 3D printing through the add-on SketchUp STL. A free licence is available for

  19. General asymmetric neutral networks and structure design by genetic algorithms: A learning rule for temporal patterns

    Energy Technology Data Exchange (ETDEWEB)

    Bornholdt, S. [Heidelberg Univ., (Germany). Inst., fuer Theoretische Physik; Graudenz, D. [Lawrence Berkeley Lab., CA (United States)

    1993-07-01

    A learning algorithm based on genetic algorithms for asymmetric neural networks with an arbitrary structure is presented. It is suited for the learning of temporal patterns and leads to stable neural networks with feedback.

  20. General asymmetric neutral networks and structure design by genetic algorithms: A learning rule for temporal patterns

    International Nuclear Information System (INIS)

    Bornholdt, S.

    1993-07-01

    A learning algorithm based on genetic algorithms for asymmetric neural networks with an arbitrary structure is presented. It is suited for the learning of temporal patterns and leads to stable neural networks with feedback

  1. Absorber Alignment Measurement Tool for Solar Parabolic Trough Collectors: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Stynes, J. K.; Ihas, B.

    2012-04-01

    As we pursue efforts to lower the capital and installation costs of parabolic trough solar collectors, it is essential to maintain high optical performance. While there are many optical tools available to measure the reflector slope errors of parabolic trough solar collectors, there are few tools to measure the absorber alignment. A new method is presented here to measure the absorber alignment in two dimensions to within 0.5 cm. The absorber alignment is measured using a digital camera and four photogrammetric targets. Physical contact with the receiver absorber or glass is not necessary. The alignment of the absorber is measured along its full length so that sagging of the absorber can be quantified with this technique. The resulting absorber alignment measurement provides critical information required to accurately determine the intercept factor of a collector.

  2. Theoretical Study of the Compound Parabolic Trough Solar Collector

    OpenAIRE

    Dr. Subhi S. Mahammed; Dr. Hameed J. Khalaf; Tadahmun A. Yassen

    2012-01-01

    Theoretical design of compound parabolic trough solar collector (CPC) without tracking is presented in this work. The thermal efficiency is obtained by using FORTRAN 90 program. The thermal efficiency is between (60-67)% at mass flow rate between (0.02-0.03) kg/s at concentration ratio of (3.8) without need to tracking system.The total and diffused radiation is calculated for Tikrit city by using theoretical equations. Good agreement between present work and the previous work.

  3. Modular Trough Power Plant Cycle and Systems Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Price, H.; Hassani, V.

    2002-01-01

    This report summarizes an analysis to reduce the cost of power production from modular concentrating solar power plants through a relatively new and exciting concept that merges two mature technologies to produce distributed modular electric power in the range of 500 to 1,500 kWe. These are the organic Rankine cycle (ORC) power plant and the concentrating solar parabolic (CSP) trough technologies that have been developed independent of each other over many years.

  4. Holocene tephra deposits in the northern Okinawa Trough

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The mineralogical and geochemical characteristics of sediments of Core CSH1, which was collected from the northern Okinawa Trough, indicate that large amounts of volcanic materials have deposited in the northern Okinawa Trough during the Holocene. On the basis of down-core variations in mineral and element contents of sediments, two layers in the uppermost section of Core CSH1 characterized by high quartz, Na2O, MnO, K2O, uranium contents and low contents of clay minerals, volatiles, Fe2O3, MgO, CaO and strontium, have been identified as the tephra deposits. Systematic grain-size measurements also suggest that sediments from the northern Okinawa Trough are made up of terrigenous materials and volcanic ashes with different proportion during the Holocene. The sediments of tephra layers in Core CSH1 show bi-modal patterns in grain-size distribution with modal grain-sizes of 74.3 and 7.81 μm,respectively. According to the radiocarbon dating on shells of zooplankton foraminifera, two tephra layers in Core CSH1, formed at 7 250 and 10 870 a BP (cal), approximately correspond to the K-Ah tephra [7 300 a BP (cal)] and the eruption of Kuju Volcano (12~10 ka BP), respectively.

  5. Chronostratigraphy and deposition rates in the Okinawa Trough region

    Institute of Scientific and Technical Information of China (English)

    李培英; 王永吉; 刘振夏

    1999-01-01

    Six representative cores from Okinawa Trough have been dated using AMS 14C, Standard 14C and ESR methods, and comparatively analysed. Systematic measurements of the oriented samples taken from the cores were conducted for obtaining their remnant magnetic polarity. With the aid of the dates obtained, particularly the AMS 14C ages of planktonic foraminiferal tests, two polarity events and two polar wanderings of the earth magnetic field have been defined. Calculations of the deposition rates for all the six core sites indicate rather high values in the trough plain, at least equivalent to those rates reported for the region of the East China Sea. They commonly range from 10 to 30 cm/ka, and even greater than 40 cm/ka in some localities. The deposition rate varied widely with topography and periods of time. In general, it is greater during the postglacial period than during the last glaciation. The chronostratigraphy in the Okinawa Trough region established through this study argues against the pr

  6. Full parabolic trough qualification from prototype to demonstration loop

    Science.gov (United States)

    Janotte, Nicole; Lüpfert, Eckhard; Pottler, Klaus; Schmitz, Mark

    2017-06-01

    On the example of the HelioTrough® collector development the full accompanying and supporting qualification program for large-scale parabolic trough collectors for solar thermal power plants is described from prototype to demonstration loop scale. In the evaluation process the actual state and the optimization potential are assessed. This includes the optical and geometrical performance determined by concentrator shape, deformation, assembly quality and local intercept factor values. Furthermore, its mechanical performance in terms of tracking accuracy and torsional stiffness and its thermal system performance on the basis of the overall thermal output and heat loss are evaluated. Demonstration loop tests deliver results of collector modules statistical slope deviation of 1.9 to 2.6 mrad, intercept factor above 98%, peak optical performance of 81.6% and heat loss coefficients from field tests. The benefit of such a closely monitored development lies in prompt feedback on strengths, weaknesses and potential improvements on the new product at any development stage from first module tests until demonstration loop evaluation. The product developer takes advantage of the achieved technical maturity, already before the implementation in a commercial power plant. The well-understood performance characteristics allow the reduction of safety margins making the new HelioTrough collector competitive from the start.

  7. Humidification dehumidification desalination system using parabolic trough solar air collector

    International Nuclear Information System (INIS)

    Al-Sulaiman, Fahad A.; Zubair, M. Ifras; Atif, Maimoon; Gandhidasan, Palanichamy; Al-Dini, Salem A.; Antar, Mohamed A.

    2015-01-01

    This paper deals with a detailed thermodynamic analysis to assess the performance of an HDH system with an integrated parabolic trough solar collector (PTSC). The HDH system considered is an open air, open water, air heated system that uses a PTSC as an air heater. Two different configurations were considered of the HDH system. In the first configuration, the solar air heater was placed before the humidifier whereas in the second configuration the solar air heater was placed between the humidifier and the dehumidifier. The current study revealed that PTSCs are well suited for air heated HDH systems for high radiation location, such as Dhahran, Saudi Arabia. The comparison between the two HDH configurations demonstrates that the gained output ratio (GOR) of the first configuration is, on average, about 1.5 whereas for the second configuration the GOR increases up to an average value of 4.7. The study demonstrates that the HDH configuration with the air heater placed between the humidifier and the dehumidifier has a better performance and a higher productivity. - Highlights: • Thermodynamic analysis of an HDH system driven by a parabolic trough solar collector was conducted. • The first configuration reveals a GOR of 1.5 while the second configuration reveals a GOR of 4.7. • Effective heating of the HDH system was obtained through parabolic trough solar collector

  8. Noble gas and carbon isotopes in Mariana Trough basalt glasses

    International Nuclear Information System (INIS)

    Bernard, M.; Jambon, A.; Gamo, T.; Nishio, Y.; Sano, Y.

    1998-01-01

    Noble gas elemental and isotopic compositions have been measured as well as the abundance of C and its isotopic ratios in 11 glasses from submarine pillow basalts collected from the Mariana Trough. The 3 He/ 4 He ratios of 8.22 and 8.51 R atm of samples dredged from the central Mariana Trough (similar18N) agree well with that of the Mid-Ocean Ridge Basalt (MORB) glasses (8.4±0.3 R atm ), whereas a mean ratio of 8.06±0.35 R atm in samples from the northern Mariana Trough (similar20N) is slightly lower than those of MORB. One sample shows apparent excess of 20 Ne and 21 Ne relative to atmospheric Ne, suggesting incorporation of solar-type Ne in the magma source. There is a positive correlation between 3 He/ 4 He and 40 Ar/ 36 Ar ratios, which may be explained by mixing between MORB-type and atmospheric noble gases. Excess 129 Xe is observed in the sample which also shows 20 Ne and 21 Ne excesses. Observed δ 13 C values of similar20N samples vary from -3.76 per thousand to -2.80 per thousand, and appear higher than those of MORB, and the corresponding CO 2 / 3 He ratios are higher than those of MARA samples at similar18N, suggesting C contribution from the subducted slab. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  9. The sedimentation rates in the Okinawa Trough during the Late Quaternary

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    On the basis of accelerator mass spectrometer radiocarbon (AMS 14C) dating, sedimentation rates of 11 cores collected from the northern to southern Okinawa Trough are discussed. The sedimentation rates in the Okinawa Trough roughly range from 11 to 39 cm/ka, and the average is 23.0 cm/ka. China's continental matter is the main sediment source of the middle Okinawa Trough and has important contribution to the northern and southern Okinawa Trough. The sedimentation rates during the marine oxygen isotope (MIS)2 are uniformly higher than those during MIS 1 in the northern and middle Okinawa Trough while they are on the contrary in the southern Okinawa Trough. Sedimentation rates in the Okinawa Trough can be one of the proxies of sediment source and an indicator of cooling events.

  10. Linear magnetic anomalies and tectonic development of the middle Okinawa Trough

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    -By analyzing the magnetic anomalies, the linear magnetic anomalies in the middle Okinawa Trough are identified. It means that the crust along the spreading axis is broken, and new oceanic crust is formed. Geophysical data have revealed that a model of three extensive episodes occurs in the Okinawa Trough, which can be named as "doming episode" from the Middle to Late Miocene (Phase I), the episode from the Pliocence to Early Pleistocene (Phase Ⅱ ), and the recent "spreading episode" (Phase Ⅲ ). The magnetic anomalies in the middle Okinawa Trough are very similar to those found in the middle Red Sea, indicating that the Okinawa Trough is developing towards the "Red Sea stage". Similar to the Red Sea, there are a "main trough" and a "axial trough" in the Okinawa Trough.

  11. Isotopic feature and uranium dating of the volcanic rocks in the Okinawa Trough

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Volcanic rocks from the northern and middle Okinawa Trough were dated by uranium-series dating method. Differential fractions using magnetic procedure were designed to separate samples. New report on the ages and isotopic data of rocks in the northern trough (especially black pumice) was discussed. Based on the uranium dates and Sr-Nd isotopic ratio, magmatic evolution process of the Okinawa Trough was noted. Firstly, there have been wide silicic volcanic activities in the Okinawa Trough from late Pleistocene to present, and the volcanic rocks can be divided into three subgroups. Secondly, magma generally came from PREMA source area under the Okinawa Trough. Magmatic evolution in the northern trough was similar to the middle, but different to the south. Finally, volcanic activities indicated that opening of the southern Okinawa Trough did not happen due to the collision between Luson Arc and Eurasian Plate until the early Pleistocene.

  12. Deep drivers of mesoscale circulation in the central Rockall Trough

    Science.gov (United States)

    Sherwin, T. J.; Alyenik, D.; Dumont, E.; Inall, M.

    2014-11-01

    Mesoscale variability in the central Rockall Trough between about 56 and 58° N has been investigated using a combination of ship-borne, underwater glider and gridded satellite altimeter measurements. Altimeter observations show that mesoscale features such as eddies and large scale circulation cells are ubiquitous phenomena. They have horizontal length scales of order 100 km with vertical scales of over 1000 m and are associated with mean current speeds (over the upper 1000 m) of 15 ± 7 cm s-1. Monthly area averaged surface Eddy Kinetic Energy (EKE) has substantial inter-annual variability, which at times can dominate a mean seasonal signal that varies from a maximum in May (74 cm2 s-2) to a minimum in October (52 cm2 s-2) and has increased gradually since 1992 at about 1.1 cm2 s-2 per year. A five month glider mission in the Trough showed that much of this energy comes from features that are located over 1000 m below the surface in the deep cold waters of the Trough (possibly from eddies associated the North Atlantic Current). The surface currents from altimeters had similar magnitude to the drift currents averaged over 1000 m from the glider in the stratified autumn, but were half the deep water speed during late winter. Although the mesoscale features move in an apparent random manner they may also be quasi-trapped by submarine topography such as seamounts. Occasionally anti-cyclonic and cyclonic cells combine to cause a coherent westward deflection of the European slope current that warms the Rockall side of the Trough. Such deflections contribute to the inter-annual variability in the observed temperature and salinity that are monitored in the upper 800 m of the Trough. By combining glider and altimeter measurements it is shown that altimeter measurements fail to observe a 15 cm s-1 northward flowing slope current on the eastern side and a small persistent southward current on the western side. There is much to be gained from the synergy between satellite

  13. Wave and plasma measurements and GPS diagnostics of the main ionospheric trough as a hybrid method used for Space Weather purposes

    Directory of Open Access Journals (Sweden)

    H. Rothkaehl

    2008-02-01

    Full Text Available The region of the main ionospheric trough is a unique region of the ionosphere, where different types of waves and instabilities can be generated. This region of the ionosphere acts like a lens, focusing a variety of indicators from the equator of plasmapause and local ionospheric plasma. This paper reports the results of monitoring the mid-latitude trough structure, dynamics and wave activity. For these purposes, the data gathered by the currently-operating DEMETER satellite and past diagnostics located on IK-19, Apex, and MAGION-3 spacecraft, as well as TEC measurements were used. A global-time varying picture of the ionospheric trough was reconstructed using the sequence of wave spectra registered and plasma measurements in the top-side ionosphere. The authors present the wave activity from ULF frequency band to the HF frequency detected inside the trough region and discuss its properties during geomagnetic disturbances. It is thought that broadband emissions are correlated with low frequency radiation, which is excited by the wave-particle interaction in the equatorial plasmapause and moves to the ionosphere along the geomagnetic field line. In the ionosphere, the suprathermal electrons can interact with these electrostatic waves and excite electron acoustic waves or HF longitudinal plasma waves.

    Furthermore, the electron density trough can provide useful data on the magnetosphere ionosphere dynamics and morphology and, in consequence, can be used for Space Weather purposes.

  14. Wave and plasma measurements and GPS diagnostics of the main ionospheric trough as a hybrid method used for Space Weather purposes

    Directory of Open Access Journals (Sweden)

    H. Rothkaehl

    2008-02-01

    Full Text Available The region of the main ionospheric trough is a unique region of the ionosphere, where different types of waves and instabilities can be generated. This region of the ionosphere acts like a lens, focusing a variety of indicators from the equator of plasmapause and local ionospheric plasma. This paper reports the results of monitoring the mid-latitude trough structure, dynamics and wave activity. For these purposes, the data gathered by the currently-operating DEMETER satellite and past diagnostics located on IK-19, Apex, and MAGION-3 spacecraft, as well as TEC measurements were used. A global-time varying picture of the ionospheric trough was reconstructed using the sequence of wave spectra registered and plasma measurements in the top-side ionosphere. The authors present the wave activity from ULF frequency band to the HF frequency detected inside the trough region and discuss its properties during geomagnetic disturbances. It is thought that broadband emissions are correlated with low frequency radiation, which is excited by the wave-particle interaction in the equatorial plasmapause and moves to the ionosphere along the geomagnetic field line. In the ionosphere, the suprathermal electrons can interact with these electrostatic waves and excite electron acoustic waves or HF longitudinal plasma waves. Furthermore, the electron density trough can provide useful data on the magnetosphere ionosphere dynamics and morphology and, in consequence, can be used for Space Weather purposes.

  15. Crystal structure representations for machine learning models of formation energies

    Energy Technology Data Exchange (ETDEWEB)

    Faber, Felix [Department of Chemistry, Institute of Physical Chemistry and National Center for Computational Design and Discovery of Novel Materials, University of Basel Switzerland; Lindmaa, Alexander [Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping Sweden; von Lilienfeld, O. Anatole [Department of Chemistry, Institute of Physical Chemistry and National Center for Computational Design and Discovery of Novel Materials, University of Basel Switzerland; Argonne Leadership Computing Facility, Argonne National Laboratory, 9700 S. Cass Avenue Lemont Illinois 60439; Armiento, Rickard [Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping Sweden

    2015-04-20

    We introduce and evaluate a set of feature vector representations of crystal structures for machine learning (ML) models of formation energies of solids. ML models of atomization energies of organic molecules have been successful using a Coulomb matrix representation of the molecule. We consider three ways to generalize such representations to periodic systems: (i) a matrix where each element is related to the Ewald sum of the electrostatic interaction between two different atoms in the unit cell repeated over the lattice; (ii) an extended Coulomb-like matrix that takes into account a number of neighboring unit cells; and (iii) an ansatz that mimics the periodicity and the basic features of the elements in the Ewald sum matrix using a sine function of the crystal coordinates of the atoms. The representations are compared for a Laplacian kernel with Manhattan norm, trained to reproduce formation energies using a dataset of 3938 crystal structures obtained from the Materials Project. For training sets consisting of 3000 crystals, the generalization error in predicting formation energies of new structures corresponds to (i) 0.49, (ii) 0.64, and (iii) 0.37eV/atom for the respective representations.

  16. Second Generation Novel High Temperature Commercial Receiver & Low Cost High Performance Mirror Collector for Parabolic Solar Trough

    Energy Technology Data Exchange (ETDEWEB)

    Stettenheim, Joel [Norwich Technologies, White River Junction, VT (United States)

    2016-02-29

    Norwich Technologies (NT) is developing a disruptively superior solar field for trough concentrating solar power (CSP). Troughs are the leading CSP technology (85% of installed capacity), being highly deployable and similar to photovoltaic (PV) systems for siting. NT has developed the SunTrap receiver, a disruptive alternative to vacuum-tube concentrating solar power (CSP) receivers, a market currently dominated by the Schott PTR-70. The SunTrap receiver will (1) operate at higher temperature (T) by using an insulated, recessed radiation-collection system to overcome the energy losses that plague vacuum-tube receivers at high T, (2) decrease acquisition costs via simpler structure, and (3) dramatically increase reliability by eliminating vacuum. It offers comparable optical efficiency with thermal loss reduction from ≥ 26% (at presently standard T) to ≥ 55% (at high T), lower acquisition costs, and near-zero O&M costs.

  17. Post-early cretaceous landform evolution along the western margin of the banca~nnia trough, western nsw

    Science.gov (United States)

    Gibson, D.L.

    2000-01-01

    Previously undated post-Devonian sediments outcropping north of Fowlers Gap station near the western margin of the Bancannia Trough are shown by plant macro- and microfossil determinations to be of Early Cretaceous (most likely Neocomian and/or Aptian) age, and thus part of the Eromanga Basin. They are assigned to the previously defined Telephone Creek Formation. Study of the structural configuration of this unit and the unconformably underlying Devonian rocks suggests that the gross landscape architecture of the area results from post-Early Cretaceous monoclinal folding along blind faults at the western margin of the trough, combined with the effects of differential erosion. This study shows that, while landscape evolution in the area has been dynamic, the major changes that have occurred are on a geological rather than human timescale.

  18. Organic geochemical characterization of potential hydrocarbon source rocks in the upper Benue Trough

    International Nuclear Information System (INIS)

    Obaje, N. G.; Pearson, M. J.; Suh, C. E.; Dada, S. S.

    1999-01-01

    The Upper Benue Trough of Nigeria is the northeastern most portion of the Benue rift structure that extends from the northern limit of the Niger Delta in the south to the southern limit of the Chad basin int he northeast. this portion of the trough is made up of two arms: the Gongola Arm and the Yola Arm. Stratigraphic sequence in the Gongola Arm comprises the continental Albian Bima Sandstone, the transitional Cenomanian Yolde Formation and the marine Turonian - Santonian Gongila, Pindiga, and Fika Formations. Overlying these are the continental Campane - Maastrichtian Gombe Sandstone and the Tertiary Kerri - Kerri Formation. In the Yola Arm, the Turonian - Santonian sequence is replaced by the equally marine Dukul, Jessu, Sekuliye Formations, Numanha Shale, and the Lamja Sandstone. Organic geochemical studies have been carried on outcrop sample form the Gongila, Pindiga, Dukul Formations, the Fika shale and the shaly units of the Gombe Sandstone, with the aim of assessing their source rock potential. Gas Chromatography (GC), Gas Chromatography - Mass Spectrometry (C - MS), and Rock Eval Pyrolysis were the major organic geochemical tools employed. Biomaker hydrocarbon signatures obtained from the GC - MS and the Rock Eval Pyrolysis results indicate that all he formations studied, except the Dukul formation, are immature and are all lean in organic matter

  19. Object tracking by occlusion detection via structured sparse learning

    KAUST Repository

    Zhang, Tianzhu

    2013-06-01

    Sparse representation based methods have recently drawn much attention in visual tracking due to good performance against illumination variation and occlusion. They assume the errors caused by image variations can be modeled as pixel-wise sparse. However, in many practical scenarios these errors are not truly pixel-wise sparse but rather sparsely distributed in a structured way. In fact, pixels in error constitute contiguous regions within the object\\'s track. This is the case when significant occlusion occurs. To accommodate for non-sparse occlusion in a given frame, we assume that occlusion detected in previous frames can be propagated to the current one. This propagated information determines which pixels will contribute to the sparse representation of the current track. In other words, pixels that were detected as part of an occlusion in the previous frame will be removed from the target representation process. As such, this paper proposes a novel tracking algorithm that models and detects occlusion through structured sparse learning. We test our tracker on challenging benchmark sequences, such as sports videos, which involve heavy occlusion, drastic illumination changes, and large pose variations. Experimental results show that our tracker consistently outperforms the state-of-the-art. © 2013 IEEE.

  20. Occlusion detection via structured sparse learning for robust object tracking

    KAUST Repository

    Zhang, Tianzhu

    2014-01-01

    Sparse representation based methods have recently drawn much attention in visual tracking due to good performance against illumination variation and occlusion. They assume the errors caused by image variations can be modeled as pixel-wise sparse. However, in many practical scenarios, these errors are not truly pixel-wise sparse but rather sparsely distributed in a structured way. In fact, pixels in error constitute contiguous regions within the object’s track. This is the case when significant occlusion occurs. To accommodate for nonsparse occlusion in a given frame, we assume that occlusion detected in previous frames can be propagated to the current one. This propagated information determines which pixels will contribute to the sparse representation of the current track. In other words, pixels that were detected as part of an occlusion in the previous frame will be removed from the target representation process. As such, this paper proposes a novel tracking algorithm that models and detects occlusion through structured sparse learning. We test our tracker on challenging benchmark sequences, such as sports videos, which involve heavy occlusion, drastic illumination changes, and large pose variations. Extensive experimental results show that our proposed tracker consistently outperforms the state-of-the-art trackers.

  1. The Learning of Biology: A Structural Basis for Future Research

    Science.gov (United States)

    Murray, Darrel L.

    1977-01-01

    This article reviews recent research studies and experiences relating the learning theories of Ausubel to biology instruction. Also some suggestions are made for future research on the learning of biology. (MR)

  2. Differently Structured Advance Organizers Lead to Different Initial Schemata and Learning Outcomes

    Science.gov (United States)

    Gurlitt, Johannes; Dummel, Sebastian; Schuster, Silvia; Nuckles, Matthias

    2012-01-01

    Does the specific structure of advance organizers influence learning outcomes? In the first experiment, 48 psychology students were randomly assigned to three differently structured advance organizers: a well-structured, a well-structured and key-concept emphasizing, and a less structured advance organizer. These were followed by a sorting task, a…

  3. On purpose simulation model for molten salt CSP parabolic trough

    Science.gov (United States)

    Caranese, Carlo; Matino, Francesca; Maccari, Augusto

    2017-06-01

    The utilization of computer codes and simulation software is one of the fundamental aspects for the development of any kind of technology and, in particular, in CSP sector for researchers, energy institutions, EPC and others stakeholders. In that extent, several models for the simulation of CSP plant have been developed with different main objectives (dynamic simulation, productivity analysis, techno economic optimization, etc.), each of which has shown its own validity and suitability. Some of those models have been designed to study several plant configurations taking into account different CSP plant technologies (Parabolic trough, Linear Fresnel, Solar Tower or Dish) and different settings for the heat transfer fluid, the thermal storage systems and for the overall plant operating logic. Due to a lack of direct experience of Molten Salt Parabolic Trough (MSPT) commercial plant operation, most of the simulation tools do not foresee a suitable management of the thermal energy storage logic and of the solar field freeze protection system, but follow standard schemes. ASSALT, Ase Software for SALT csp plants, has been developed to improve MSPT plant's simulations, by exploiting the most correct operational strategies in order to provide more accurate technical and economical results. In particular, ASSALT applies MSPT specific control logics for the electric energy production and delivery strategy as well as the operation modes of the Solar Field in off-normal sunshine condition. With this approach, the estimated plant efficiency is increased and the electricity consumptions required for the plant operation and management is drastically reduced. Here we present a first comparative study on a real case 55 MWe Molten Salt Parabolic Trough CSP plant placed in the Tibetan highlands, using ASSALT and SAM (System Advisor Model), which is a commercially available simulation tool.

  4. Theoretical Study of the Compound Parabolic Trough Solar Collector

    Directory of Open Access Journals (Sweden)

    Dr. Subhi S. Mahammed

    2012-06-01

    Full Text Available Theoretical design of compound parabolic trough solar collector (CPC without tracking is presented in this work. The thermal efficiency is obtained by using FORTRAN 90 program. The thermal efficiency is between (60-67% at mass flow rate between (0.02-0.03 kg/s at concentration ratio of (3.8 without need to tracking system.The total and diffused radiation is calculated for Tikrit city by using theoretical equations. Good agreement between present work and the previous work.

  5. Social learning of vocal structure in a nonhuman primate?

    Directory of Open Access Journals (Sweden)

    Lemasson Alban

    2011-12-01

    Full Text Available Abstract Background Non-human primate communication is thought to be fundamentally different from human speech, mainly due to vast differences in vocal control. The lack of these abilities in non-human primates is especially striking if compared to some marine mammals and bird species, which has generated somewhat of an evolutionary conundrum. What are the biological roots and underlying evolutionary pressures of the human ability to voluntarily control sound production and learn the vocal utterances of others? One hypothesis is that this capacity has evolved gradually in humans from an ancestral stage that resembled the vocal behavior of modern primates. Support for this has come from studies that have documented limited vocal flexibility and convergence in different primate species, typically in calls used during social interactions. The mechanisms underlying these patterns, however, are currently unknown. Specifically, it has been difficult to rule out explanations based on genetic relatedness, suggesting that such vocal flexibility may not be the result of social learning. Results To address this point, we compared the degree of acoustic similarity of contact calls in free-ranging Campbell's monkeys as a function of their social bonds and genetic relatedness. We calculated three different indices to compare the similarities between the calls' frequency contours, the duration of grooming interactions and the microsatellite-based genetic relatedness between partners. We found a significantly positive relation between bond strength and acoustic similarity that was independent of genetic relatedness. Conclusion Genetic factors determine the general species-specific call repertoire of a primate species, while social factors can influence the fine structure of some the call types. The finding is in line with the more general hypothesis that human speech has evolved gradually from earlier primate-like vocal communication.

  6. Putting Structure to Flipped Classrooms Using Team-Based Learning

    Science.gov (United States)

    Jakobsen, Krisztina V.; Knetemann, Megan

    2017-01-01

    Current educational practices and cognitive-developmental theories emphasize the importance of active participation in the learning environment, and they suggest that the first, and arguably most important, step to creating a better learning environment is to make learning an active and reciprocal process. Flipped classrooms, in which students…

  7. A framework for adaptive e-learning for continuum mechanics and structural analysis

    OpenAIRE

    Mosquera Feijoo, Juan Carlos; Plaza Beltrán, Luis Francisco; González Rodrigo, Beatriz

    2015-01-01

    This paper presents a project for providing the students of Structural Engineering with the flexibility to learn outside classroom schedules. The goal is a framework for adaptive E-learning based on a repository of open educational courseware with a set of basic Structural Engineering concepts and fundamentals. These are paramount for students to expand their technical knowledge and skills in structural analysis and design of tall buildings, arch-type structures as well as bridges. Thus, conc...

  8. Organizational structure and continuous improvement and learning: Moderating effects of cultural endorsement of participative leadership

    OpenAIRE

    Xiaowen Huang; Joseph C Rode; Roger G Schroeder

    2011-01-01

    Building upon the culturally endorsed implicit theory of leadership, we investigated the moderating effects of national culture on the relationship between organizational structure and continuous improvement and learning. We propose that the relationship between organic organizations (characterized by flat, decentralized structures with a wide use of multifunctional employees) and continuous improvement and learning will be stronger when national cultural endorsement for participative leaders...

  9. The F-region trough: seasonal morphology and relation to interplanetary magnetic field

    Directory of Open Access Journals (Sweden)

    M. Voiculescu

    2006-03-01

    Full Text Available We present here the results of a statistical study of the ionospheric trough observed in 2003 by means of satellite tomography. We focus on the seasonal morphology of the trough occurrence and investigate the trough latitude, width and the horizontal gradients at the edges, at different magnetic local times, as well as their relations to geomagnetic activity and the interplanetary magnetic field. A seasonal effect is noticed in the diurnal variation of the trough latitude, indicating that summer clearly differs from the other seasons. In winter the troughs seem to follow the solar terminator. The width of the trough has a diurnal variation and it depends on the season, as well. The broadest troughs are observed in winter and the narrowest ones in summer. A discontinuity in the diurnal variation of the trough latitude is observed before noon. It is suggested that this is an indication of a difference between the generation mechanisms of morningside and eveningside troughs. The density gradients at the edges have a complex dependence on the latitude of the trough and on geomagnetic activity. The photoionization and the auroral precipitation are competing in the formation of the trough walls at different magnetic local times. An important finding is that the interplanetary magnetic field plays a role in the occurrence of the trough at different levels of geomagnetic activity. This is probably associated with the topology of the polar cap convection pattern, which depends on the directions of the IMF components By and Bz.

  10. Effects of structured versus non-structured learning on achievement and attitudes of fifth graders in a public aquarium

    Science.gov (United States)

    Kafka, Merryl Audrey

    The investigator analyzed the main effect of a structured-learning experience in an informal setting, as well as interactions between the students' learning-style variations toward the element of structure and the imposed instructional conditions. The subjects consisted of 170 students enrolled in two public schools located in Brooklyn, New York. The students were predominantly a White multi-ethnic population consisting of 118 Caucasians, 25 Hispanics, 24 Asians, and 3 African-Americans. Three randomly assigned classes (n = 81) were provided trip sheets, which directed students on how to learn new information with written questions and directives. Three randomly assigned non-structured classes (n = 89) experienced the same exhibit in a free-form manner. Science-based criterion-referenced pre- and posttests were administered, in addition to Learning Style Inventories (Dunn, Dunn, & Price, 1996) and a modified Semantic Differential Scale (Pizzo, 1981), which was used to measure attitudinal levels. The non-structured group had access to similar content information in the form of exhibit graphics, but apparently they chose not to read it as carefully or engage in the information-seeking process as intensely as the students equipped with trip sheets. Analysis of covariance (ANCOVA) indicated that a structured-learning experience produced significantly higher science-achievement test scores than in a non-structured-learning experience (p = .0001). In addition, there was no single learning-style variation (preference, aversion, or no preference) to structure that produced significantly higher gains than another. Furthermore, attitudinal scores were not significantly different between structured and non-structured groups, as well as among homogeneous subsets of students with learning-style variations that matched, mismatched, or indicated no-preferenced positions on the element of structure. Hence, a moderate amount of structure resulted in academic gains without

  11. Probabilistic tsunami hazard assessment considering time-lag of seismic event on Nankai trough

    International Nuclear Information System (INIS)

    Sugino, Hideharu; Sakagami, Masaharu; Ebisawa, Katsumi; Korenaga, Mariko

    2011-01-01

    In the area in front of Nankai trough, tsunami wave height may increase if tsunamis attacking from some wave sources overlap because of time-lag of seismic event on Nankai trough. To evaluation tsunami risk of the important facilities located in front of Nankai trough, we proposed the probabilistic tsunami hazard assessment considering uncertainty on time-lag of seismic event on Nankai trough and we evaluated the influence that the time-lag gave to tsunami hazard at the some representative points. (author)

  12. Multi-parameter optimization design of parabolic trough solar receiver

    International Nuclear Information System (INIS)

    Guo, Jiangfeng; Huai, Xiulan

    2016-01-01

    Highlights: • The optimal condition can be obtained by multi-parameter optimization. • Exergy and thermal efficiencies are employed as objective function. • Exergy efficiency increases at the expense of heat losses. • The heat obtained by working fluid increases as thermal efficiency grows. - Abstract: The design parameters of parabolic trough solar receiver are interrelated and interact with one another, so the optimal performance of solar receiver cannot be obtained by the convectional single-parameter optimization. To overcome the shortcoming of single-parameter optimization, a multi-parameter optimization of parabolic trough solar receiver is employed based on genetic algorithm in the present work. When the thermal efficiency is taken as the objective function, the heat obtained by working fluid increases while the average temperature of working fluid and wall temperatures of solar receiver decrease. The average temperature of working fluid and the wall temperatures of solar receiver increase while the heat obtained by working fluid decreases generally by taking the exergy efficiency as an objective function. Assuming that the solar radiation intensity remains constant, the exergy obtained by working fluid increases by taking exergy efficiency as the objective function, which comes at the expense of heat losses of solar receiver.

  13. EFFECTIVENESS OF MULTIMEDIA IN LEARNING & TEACHING DATA STRUCTURES ONLINE

    Directory of Open Access Journals (Sweden)

    Sahalu JUNAIDU

    2008-10-01

    Full Text Available Online electronic education is now being widely accepted as a major viable component of higher education. This is fuelled by the emergence of worldwide information and computer communications technologies. However, online education is not being adopted in science and engineering subjects as widely as in other fields because of the idiosyncrasies of some science and engineering-based courses. For online engineering education to be broadly accepted and utilized, the quality of online courses must, amongst other things, be comparable to or better than those of traditional face-to-face classroom education. This paper explores and reports on the importance of creating multimedia-rich course content and the important role that animations can play in creating a successful online learning experience. Results of our study on an online data structures course over five years offerings show that students consistently perform much better in questions requiring application of material taught in carefully animated algorithms. These results should carry over to other educational environments.

  14. Balancing Structure and Learning in an Open Prison

    Directory of Open Access Journals (Sweden)

    Per Johansen

    2013-01-01

    Full Text Available Leira Prison is a branch of Trondheim Prison, functioning as a relatively small,open prison with a maximum capacity of only 29 inmates. Leira Prison appliesthe method ‘consequence pedagogy.’ This article aims to pinpoint howconsequence pedagogy is executed at Leira. 50% of the Leira inmates arereleased back into society, while new ones enter the prison. It is thereforeinteresting to see how they balance structure and at the same time adjust tochanges, enabling Leira Prison to continue as a learning organization. This articleidentifies three items, consequence pedagogy and the view of humans,maintenance of the philosophy and coherence in the community, and selfregulationof justice through interaction. The use of consequence pedagogyis deeply aligned to their positive view of humans and has generated a constructiveorganization based on empowerment and involvement of both staffand inmates. Consequently, management, staff and inmates maintain thephilosophy of consequence pedagogy through interaction and self-regulation.However, questions regarding the fundamentals of the consequence pedagogyare not raised.

  15. Learning of pitch and time structures in an artificial grammar setting.

    Science.gov (United States)

    Prince, Jon B; Stevens, Catherine J; Jones, Mari Riess; Tillmann, Barbara

    2018-04-12

    Despite the empirical evidence for the power of the cognitive capacity of implicit learning of structures and regularities in several modalities and materials, it remains controversial whether implicit learning extends to the learning of temporal structures and regularities. We investigated whether (a) an artificial grammar can be learned equally well when expressed in duration sequences as when expressed in pitch sequences, (b) learning of the artificial grammar in either duration or pitch (as the primary dimension) sequences can be influenced by the properties of the secondary dimension (invariant vs. randomized), and (c) learning can be boosted when the artificial grammar is expressed in both pitch and duration. After an exposure phase with grammatical sequences, learning in a subsequent test phase was assessed in a grammaticality judgment task. Participants in both the pitch and duration conditions showed incidental (not fully implicit) learning of the artificial grammar when the secondary dimension was invariant, but randomizing the pitch sequence prevented learning of the artificial grammar in duration sequences. Expressing the artificial grammar in both pitch and duration resulted in disproportionately better performance, suggesting an interaction between the learning of pitch and temporal structure. The findings are relevant to research investigating the learning of temporal structures and the learning of structures presented simultaneously in 2 dimensions (e.g., space and time, space and objects). By investigating learning, the findings provide further insight into the potential specificity of pitch and time processing, and their integrated versus independent processing, as previously debated in music cognition research. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  16. Monitoring of Students' Interaction in Online Learning Settings by Structural Network Analysis and Indicators.

    Science.gov (United States)

    Ammenwerth, Elske; Hackl, Werner O

    2017-01-01

    Learning as a constructive process works best in interaction with other learners. Support of social interaction processes is a particular challenge within online learning settings due to the spatial and temporal distribution of participants. It should thus be carefully monitored. We present structural network analysis and related indicators to analyse and visualize interaction patterns of participants in online learning settings. We validate this approach in two online courses and show how the visualization helps to monitor interaction and to identify activity profiles of learners. Structural network analysis is a feasible approach for an analysis of the intensity and direction of interaction in online learning settings.

  17. CREB Selectively Controls Learning-Induced Structural Remodeling of Neurons

    Science.gov (United States)

    Middei, Silvia; Spalloni, Alida; Longone, Patrizia; Pittenger, Christopher; O'Mara, Shane M.; Marie, Helene; Ammassari-Teule, Martine

    2012-01-01

    The modulation of synaptic strength associated with learning is post-synaptically regulated by changes in density and shape of dendritic spines. The transcription factor CREB (cAMP response element binding protein) is required for memory formation and in vitro dendritic spine rearrangements, but its role in learning-induced remodeling of neurons…

  18. The Space for Social Media in Structured Online Learning

    Science.gov (United States)

    Salmon, Gilly; Ross, Bella; Pechenkina, Ekaterina; Chase, Anne-Marie

    2015-01-01

    In this paper, we explore the benefits of using social media in an online educational setting, with a particular focus on the use of Facebook and Twitter by participants in a Massive Open Online Course (MOOC) developed to enable educators to learn about the Carpe Diem learning design process. We define social media as digital social tools and…

  19. Modeling Meaningful Learning in Chemistry Using Structural Equation Modeling

    Science.gov (United States)

    Brandriet, Alexandra R.; Ward, Rose Marie; Bretz, Stacey Lowery

    2013-01-01

    Ausubel and Novak's construct of "meaningful learning" stipulates that substantive connections between new knowledge and what is already known requires the integration of thinking, feeling, and performance (Novak J. D., (2010), "Learning, creating, and using knowledge: concept maps as facilitative tools in schools and…

  20. Trough Concentrations of Vancomycin in Patients Undergoing Extracorporeal Membrane Oxygenation.

    Directory of Open Access Journals (Sweden)

    So Jin Park

    Full Text Available To investigate the appropriateness of the current vancomycin dosing strategy in adult patients with extracorporeal membrane oxygenation (ECMO, between March 2013 and November 2013, patients who were treated with vancomycin while on ECMO were enrolled. Control group consisted of 60 patients on vancomycin without ECMO, stayed in medical intensive care unit during the same study period and with the same exclusion criteria. Early trough levels were obtained within the fourth dosing, and maintenance levels were measured at steady state. A total of 20 patients were included in the analysis in ECMO group. Sixteen patients received an initial intravenous dose of 1.0 g vancomycin followed by 1.0 g every 12 hours. The non-steady state trough level of vancomycin after starting administration was subtherapeutic in 19 patients (95.00% in ECMO group as compared with 40 patients (66.67% in the control group (p = 0.013. Vancomycin clearance was 1.27±0.51 mL/min/kg, vancomycin clearance/creatinine clearance ratio was 0.90 ± 0.37, and elimination rate constant was 0.12 ± 0.04 h-1. Vancomycin dosingfrequency and total daily dose were significantly increased after clinical pharmacokinetic services of the pharmacist based on calculated pharmacokinetic parameters (from 2.10 ± 0.72 to 2.90 ± 0.97 times/day, p = 0.002 and from 32.54 ± 8.43 to 42.24 ± 14.62mg/kg, p = 0.014 in ECMO group in contrast with those (from 2.11 ± 0.69 to 2.37 ± 0.86 times/day, p = 0.071 and from 33.91 ± 11.85 to 31.61 ± 17.50 mg/kg, p = 0.350 in the control group.Although the elimination rate for vancomycin was similar with population parameter of non ECMO patients, the current dosing strategy of our institution for vancomycinin our ICU was not sufficient to achieve the target trough in the initial period in most patients receiving ECMO.

  1. Depositional evolution of the Melville Bay trough-mouth fan, NW Greenland

    Science.gov (United States)

    Knutz, Paul; Gregersen, Ulrik

    2015-04-01

    The continental margin of NW Greenland bordering northern Baffin Bay is characterized by major sediment accumulations, known as Trough-Mouth Fans (TMF). The fan depocentres represent intense sediment dispersal at the terminus of ice streams that during cold climate periods provided major drainage routes of the northern Greenland Ice Sheet into Baffin Bay. The imprint of paleo-icestreams is seen by erosional troughs crossing a >250 km broad shelf region, which caps a series of sedimentary basins containing thick Mesozoic-Tertiary strata packages. This presentation provides an overview of the seismic stratigraphic division, depositional architecture and examples of seismic facies of the Melville Bay TMF using a 5-10 km grid of industry-quality 2D seismic data (TGS). The focus will primarily be on the inception and early stage of glacial fan development. Comparing the present-day topography with the regional geology shows that the paleo-icestreams exploited the Cenozoic infill of former rift basins that are more conducive to erosion than the adjoining ridges and structural highs. The TMF sequence is constructed by a series of progradational seismic units that represent successive steps in location of ice stream terminus and associated depocenters. The slope fronts of the prograding units show abundant signatures of sediment instability and mass-wasting but evidence of along-slope current-driven processes is also recognized presumably linked to interglacial sea level high-stands. The topset of each unit is characterized by planar erosion that merges landward into hummocky positive geometries with low internal reflectivity. These features are generally interpreted as subglacial landforms, e.g. terminal moraines and ice-contact deposits, associated with grounding zone wedges. Unlike the most recent TMF units deposited in front of the present trough, the oldest glacigenic units have built out from a Neogene sediment prism that forms the core of modern shallow-water banks

  2. Three-dimensional distribution of random velocity inhomogeneities at the Nankai trough seismogenic zone

    Science.gov (United States)

    Takahashi, T.; Obana, K.; Yamamoto, Y.; Nakanishi, A.; Kaiho, Y.; Kodaira, S.; Kaneda, Y.

    2012-12-01

    The Nankai trough in southwestern Japan is a convergent margin where the Philippine sea plate is subducted beneath the Eurasian plate. There are major faults segments of huge earthquakes that are called Tokai, Tonankai and Nankai earthquakes. According to the earthquake occurrence history over the past hundreds years, we must expect various rupture patters such as simultaneous or nearly continuous ruptures of plural fault segments. Japan Agency for Marine-Earth Science and Technology (JAMSTEC) conducted seismic surveys at Nankai trough in order to clarify mutual relations between seismic structures and fault segments, as a part of "Research concerning Interaction Between the Tokai, Tonankai and Nankai Earthquakes" funded by Ministry of Education, Culture, Sports, Science and Technology, Japan. This study evaluated the spatial distribution of random velocity inhomogeneities from Hyuga-nada to Kii-channel by using velocity seismograms of small and moderate sized earthquakes. Random velocity inhomogeneities are estimated by the peak delay time analysis of S-wave envelopes (e.g., Takahashi et al. 2009). Peak delay time is defined as the time lag from the S-wave onset to its maximal amplitude arrival. This quantity mainly reflects the accumulated multiple forward scattering effect due to random inhomogeneities, and is quite insensitive to the inelastic attenuation. Peak delay times are measured from the rms envelopes of horizontal components at 4-8Hz, 8-16Hz and 16-32Hz. This study used the velocity seismograms that are recorded by 495 ocean bottom seismographs and 378 onshore seismic stations. Onshore stations are composed of the F-net and Hi-net stations that are maintained by National Research Institute for Earth Science and Disaster Prevention (NIED) of Japan. It is assumed that the random inhomogeneities are represented by the von Karman type PSDF. Preliminary result of inversion analysis shows that spectral gradient of PSDF (i.e., scale dependence of

  3. Architectural frameworks: defining the structures for implementing learning health systems.

    Science.gov (United States)

    Lessard, Lysanne; Michalowski, Wojtek; Fung-Kee-Fung, Michael; Jones, Lori; Grudniewicz, Agnes

    2017-06-23

    The vision of transforming health systems into learning health systems (LHSs) that rapidly and continuously transform knowledge into improved health outcomes at lower cost is generating increased interest in government agencies, health organizations, and health research communities. While existing initiatives demonstrate that different approaches can succeed in making the LHS vision a reality, they are too varied in their goals, focus, and scale to be reproduced without undue effort. Indeed, the structures necessary to effectively design and implement LHSs on a larger scale are lacking. In this paper, we propose the use of architectural frameworks to develop LHSs that adhere to a recognized vision while being adapted to their specific organizational context. Architectural frameworks are high-level descriptions of an organization as a system; they capture the structure of its main components at varied levels, the interrelationships among these components, and the principles that guide their evolution. Because these frameworks support the analysis of LHSs and allow their outcomes to be simulated, they act as pre-implementation decision-support tools that identify potential barriers and enablers of system development. They thus increase the chances of successful LHS deployment. We present an architectural framework for LHSs that incorporates five dimensions-goals, scientific, social, technical, and ethical-commonly found in the LHS literature. The proposed architectural framework is comprised of six decision layers that model these dimensions. The performance layer models goals, the scientific layer models the scientific dimension, the organizational layer models the social dimension, the data layer and information technology layer model the technical dimension, and the ethics and security layer models the ethical dimension. We describe the types of decisions that must be made within each layer and identify methods to support decision-making. In this paper, we outline

  4. Air-borne shape measurement of parabolic trough collector fields

    Science.gov (United States)

    Prahl, Christoph; Röger, Marc; Hilgert, Christoph

    2017-06-01

    The optical and thermal efficiency of parabolic trough collector solar fields is dependent on the performance and assembly accuracy of its components such as the concentrator and absorber. For the purpose of optical inspection/approval, yield analysis, localization of low performing areas, and optimization of the solar field, it is essential to create a complete view of the optical properties of the field. Existing optical measurement tools are based on ground based cameras, facing restriction concerning speed, volume and automation. QFly is an airborne qualification system which provides holistic and accurate information on geometrical, optical, and thermal properties of the entire solar field. It consists of an unmanned aerial vehicle, cameras and related software for flight path planning, data acquisition and evaluation. This article presents recent advances of the QFly measurement system and proposes a methodology on holistic qualification of the complete solar field with minimum impact on plant operation.

  5. Test results, Industrial Solar Technology parabolic trough solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Dudley, V.E. [EG and G MSI, Albuquerque, NM (United States); Evans, L.R.; Matthews, C.W. [Sandia National Labs., Albuquerque, NM (United States)

    1995-11-01

    Sandia National Laboratories and Industrial Solar Technology are cost-sharing development of advanced parabolic trough technology. As part of this effort, several configurations of an IST solar collector were tested to determine the collector efficiency and thermal losses with black chrome and black nickel receiver selective coatings, combined with aluminized film and silver film reflectors, using standard Pyrex{reg_sign} and anti-reflective coated Pyrex{reg_sign} glass receiver envelopes. The development effort has been successful, producing an advanced collector with 77% optical efficiency, using silver-film reflectors, a black nickel receiver coating, and a solgel anti-reflective glass receiver envelope. For each receiver configuration, performance equations were empirically derived relating collector efficiency and thermal losses to the operating temperature. Finally, equations were derived showing collector performance as a function of input insolation value, incident angle, and operating temperature.

  6. The trochlear cleft: the ''black line'' of the trochlear trough

    International Nuclear Information System (INIS)

    Wissman, Robert D.; Nepute, Joshua; Fischer, Nathaniel von; Radhakrishnan, Rupa; Hendry, Daniel; Ingalls, Jerrell; Kenter, Keith

    2012-01-01

    The ''cartilage black line sign'' is a recently described T2 dark cartilage lesion that we have identified appearing as a cleft in the trochlear trough. The purpose of our study was to define the MR imaging characteristics of a trochlear cleft, determine its incidence, and correlate the MR findings with arthroscopy. A total of 1,300 consecutive MR examinations of the knee were retrospectively reviewed by consensus of two fellowship-trained musculoskeletal radiologists. The MR imaging characteristics and location of a trochlear cleft were determined. Imaging results were compared to arthroscopy when available. Patient age and gender were compared to 25 randomly selected control patients without trochlear clefts. A total of 25 (1.9%) individuals (11 females and 14 males; age range 19-45 years; mean age 28 years) were diagnosed with a trochlear cleft. The control group consisted of 11 females and 14 males; age range 19-83 years; mean age 46 years. Mean cleft length was 7 mm (range 6-12 mm); cleft location was consistently in the lower trochlear trough. No full-thickness cartilage defects were identified in the eight individuals in whom arthroscopic correlation was available. A grade 2 cartilage lesion was identified in a single individual; another progressed from grade 0 to a full-thickness trochlear lesion over an 8-month interval. Eight individuals were athletes. No significant difference in gender was noted between the two groups, however, the study group was significantly younger p < 0.0001. A trochlear cleft is a rare finding in young active individuals. It most likely indicates an incomplete cartilage fissure which may rarely progress to a full-thickness defect. (orig.)

  7. An experimental study of thermal characterization of parabolic trough receivers

    International Nuclear Information System (INIS)

    Lei, Dongqiang; Li, Qiang; Wang, Zhifeng; Li, Jian; Li, Jianbin

    2013-01-01

    Highlights: ► A new test stand of heat loss has been developed at IEECAS. ► A correlation between heat loss and absorber temperature is presented, 270 W/m 400 °C. ► The ratio of end loss in total heat loss increases with decreasing the temperature. ► The emittance test stand using a high vacuum system and vacuum gauge is built. ► Emittance first decreases, then rapidly increases with increasing the temperature. - Abstract: The receiver is a key component of the parabolic trough solar station. The receiver requires the most challenging technology and has a decisive influence on the thermal and economic performance of a power plant. The Institute of Electrical Engineering Chinese Academy Sciences (IEECAS) and Himin Solar Co., Ltd. (HSC) cooperated to develop solar receivers for the first 50 MW parabolic trough project in Inner Mongolia, China. This paper examines overall heat loss, end loss and thermal emittance of the coating of a newly designed receiver in order to evaluate its thermal characterization. A series of heat loss tests are conducted in a newly developed test stand following the steady state equilibrium method. The tests provide a correlation between heat loss and the absorber temperature. This paper presents a new testing method to accurately test the coating emittance. The method uses a receiver with a high vacuum system and a vacuum gauge to maintain continuous exhaust and high vacuum throughout the heat loss testing. A heat loss comparison between the receiver and other existing receivers provides a reference that enabled further optimization. Theoretical and experimental analysis examines the effects of end loss both with and without a heat insulator and a coil heater. The emittance curves of different coatings are acquired and the reasons for initial emittance decrease and then remarkable increase versus temperature are analyzed

  8. Probabilistic models and machine learning in structural bioinformatics

    DEFF Research Database (Denmark)

    Hamelryck, Thomas

    2009-01-01

    . Recently, probabilistic models and machine learning methods based on Bayesian principles are providing efficient and rigorous solutions to challenging problems that were long regarded as intractable. In this review, I will highlight some important recent developments in the prediction, analysis...

  9. Concurrent immunomodulator therapy is associated with higher adalimumab trough levels during scheduled maintenance therapy.

    Science.gov (United States)

    Bond, Ashley; Dodd, Susanna; Fisher, Gareth; Skouras, Thomas; Subramanian, Sreedhar

    2017-02-01

    Combination therapy with infliximab and immunomodulators is superior to monotherapy, resulting in better outcomes and higher trough levels of infliximab. The role of concurrent immunomodulatory therapy on adalimumab trough levels has not been adequately investigated. We evaluated the impact of concomitant immunomodulation on adalimumab trough levels in patients on scheduled maintenance therapy. We conducted a prospective observational, cross-sectional study of all inflammatory bowel disease patients on maintenance therapy who had adalimumab trough levels measured between January 2013 and January 2016. Drug level and anti-drug antibody measurements were performed on sera using a solid phase assay. Pairwise comparison of means was used to compare trough levels in patients with and without concomitant immune modulator therapy. In total, 79 patients were included. Twenty-three patients (29.1%) were on weekly dosing whereas 56 (70.9%) were on alternate weeks. Median adalimumab trough levels were comparable in patients with and without clinical remission (6.8 μg/ml (IQR 5.6-8.1) versus 6.7 μg/ml (IQR 3.9-8.1), respectively. Patients with an elevated faecal calprotectin >250 μg/g had lower adalimumab trough levels (median 6.7, IQR 3.9-8) compared to patients with faecal calprotectin <250 μg/g (median 7.7, IQR 6.1-8.1) though this did not achieve statistical significance (p = .062). Median adalimumab trough levels among patients on concurrent immunomodulators was 7.2 μg/ml (IQR 5.7-8.1) compared to those not on concurrent immunomodulator, 6.1 μg/ml (IQR 2.7-7.7, p = .0297). Adalimumab trough levels were significantly higher in patients on concurrent immunomodulators during maintenance therapy. There was a trend towards a lower adalimumab trough level in patients with elevated calprotectin.

  10. Aeolian sand transport over complex intertidal bar-trough beach topography

    Science.gov (United States)

    Anthony, Edward J.; Ruz, Marie-Hélène; Vanhée, Stéphane

    2009-04-01

    Aeolian sand transport on macrotidal beaches with complex intertidal bar-trough topography (ridge-and-runnel beaches) was assessed from experiments in northern France that involved measurements of wind speed, saltation, surface moisture contents, and rates of sand trapping across surveyed portions of the upper beach profile. Beaches exhibiting intertidal bars and troughs are much more complex, topographically, than simple reflective or dissipative beaches. Furthermore, the intertidal bar-trough morphology commonly exhibits strong cross-shore variations in the moisture contents of the beach surface and in patterns of bedform development. The results of four 30-minute experiments, conducted along topographically surveyed portions of the upper beach-dune toe profile, show that troughs act as extremely efficient sand interceptors, because of their permanently saturated state, which also inhibits sand mobilisation. Troughs, thus, limit or segment the dry fetch during conditions of intermittent saltation. Flow lines, inferred from the wind profiles, suggest that complex interactions at the boundary layer are generated by the bar-trough topography. Troughs systematically appear to be characterised by air expansion, while bar faces generate ramp wind acceleration for onshore winds, and sometimes immediate downwind deceleration for offshore winds. These effects may also contribute to cross-shore variations in the rates of sand trapping. Finally, a simple conceptual model of effective fetch development, integrating the effects of the spring-neap tidal range and of gross bar-trough morphological variability over time, is proposed for bar-trough beaches. The model highlights the key theme of fetch segmentation induced by cross-shore differentiation in the moisture contents of the beach surface hinged on the complex topography of multiple bars and troughs.

  11. Gravimetric model of the Gastre trough, province of Chubut, Argentina; Modelo gravimetrico en la fosa de Gastre, provincia de Chubut, Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Lince Klinger, F.; Nacif, S.; Martinez, M. P.; Gimenez, M. E.; Ruiz, F.; Alvarez, O.

    2011-07-01

    A gravimetric study of the Gastre trough in the Province of Chubut, to the southwest of the Canadon Asfalto basin, has allowed us to determine the geometry of its crystalline basement. Using filtering techniques we were able to map residual Bouguer anomalies, which show the heterogeneities situated within the upper crust, some of which are linked to recognised geological structures. The gravimetric minima in the residual Bouguer anomaly map are associated with graben-type basins, flanked by positive gravity values associated with alignments identified on the surface and with the overall topographic relief of the Gastre trough. After suitable treatment of the density values of the outcrops and seismic data we were able to construct a 2D density model, perpendicular to the trough, which indicated a depth of 3600 m. The importance of this study lies in the fact that it has been possible to arrive at a gravimetric characterization of the Gastre trough in the Canadon Asfalto basin sector, a potentially hydrocarbon-bearing area hitherto lacking in reliable data concerning its subsoil. (Author)

  12. Integrating Model-Based Learning and Animations for Enhancing Students' Understanding of Proteins Structure and Function

    Science.gov (United States)

    Barak, Miri; Hussein-Farraj, Rania

    2013-01-01

    This paper describes a study conducted in the context of chemistry education reforms in Israel. The study examined a new biochemistry learning unit that was developed to promote in-depth understanding of 3D structures and functions of proteins and nucleic acids. Our goal was to examine whether, and to what extent teaching and learning via…

  13. Modularization and Structured Markup for Learning Content in an Academic Environment

    Science.gov (United States)

    Schluep, Samuel; Bettoni, Marco; Schar, Sissel Guttormsen

    2006-01-01

    This article aims to present a flexible component model for modular, web-based learning content, and a simple structured markup schema for the separation of content and presentation. The article will also contain an overview of the dynamic Learning Content Management System (dLCMS) project, which implements these concepts. Content authors are a…

  14. Structuring Cooperative Learning for Motivation and Conceptual Change in the Concepts of Mixtures

    Science.gov (United States)

    Belge Can, Hatice; Boz, Yezdan

    2016-01-01

    This study investigates the effect of structuring cooperative learning based on conceptual change approach on grade 9 students' understanding the concepts of mixtures and their motivation, compared with traditional instruction. Among six classes of a high school, two of them were randomly assigned to cooperative learning group where students were…

  15. BDgraph: An R Package for Bayesian Structure Learning in Graphical Models

    NARCIS (Netherlands)

    Mohammadi, A.; Wit, E.C.

    2017-01-01

    Graphical models provide powerful tools to uncover complicated patterns in multivariate data and are commonly used in Bayesian statistics and machine learning. In this paper, we introduce an R package BDgraph which performs Bayesian structure learning for general undirected graphical models with

  16. Learning Practice and Technology: Extending the Structurational Practice Lens to Educational Technology Research

    Science.gov (United States)

    Halperin, Ruth

    2017-01-01

    Scholars in the field of educational technology have been calling for robust use of social theory within learning technology research. In view of that, interest has been noted in applying Giddens' structuration theory to the understanding of human interaction with technology in learning settings. However, only few such attempts have been published…

  17. Perceptual Learning in Early Mathematics: Interacting with Problem Structure Improves Mapping, Solving and Fluency

    Science.gov (United States)

    Thai, Khanh-Phuong; Son, Ji Y.; Hoffman, Jessica; Devers, Christopher; Kellman, Philip J.

    2014-01-01

    Mathematics is the study of structure but students think of math as solving problems according to rules. Students can learn procedures, but they often have trouble knowing when to apply learned procedures, especially to problems unlike those they trained with. In this study, the authors rely on the psychological mechanism of perceptual learning…

  18. Real-Time Probabilistic Structural Health Management Using Machine Learning and GPU Computing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project seeks to deliver an ultra-efficient, high-fidelity structural health management (SHM) framework using machine learning and graphics processing...

  19. Learning about the internal structure of categories through classification and feature inference.

    Science.gov (United States)

    Jee, Benjamin D; Wiley, Jennifer

    2014-01-01

    Previous research on category learning has found that classification tasks produce representations that are skewed toward diagnostic feature dimensions, whereas feature inference tasks lead to richer representations of within-category structure. Yet, prior studies often measure category knowledge through tasks that involve identifying only the typical features of a category. This neglects an important aspect of a category's internal structure: how typical and atypical features are distributed within a category. The present experiments tested the hypothesis that inference learning results in richer knowledge of internal category structure than classification learning. We introduced several new measures to probe learners' representations of within-category structure. Experiment 1 found that participants in the inference condition learned and used a wider range of feature dimensions than classification learners. Classification learners, however, were more sensitive to the presence of atypical features within categories. Experiment 2 provided converging evidence that classification learners were more likely to incorporate atypical features into their representations. Inference learners were less likely to encode atypical category features, even in a "partial inference" condition that focused learners' attention on the feature dimensions relevant to classification. Overall, these results are contrary to the hypothesis that inference learning produces superior knowledge of within-category structure. Although inference learning promoted representations that included a broad range of category-typical features, classification learning promoted greater sensitivity to the distribution of typical and atypical features within categories.

  20. The space for social media in structured online learning

    Directory of Open Access Journals (Sweden)

    Gilly Salmon

    2015-12-01

    Full Text Available In this paper, we explore the benefits of using social media in an online educational setting, with a particular focus on the use of Facebook and Twitter by participants in a Massive Open Online Course (MOOC developed to enable educators to learn about the Carpe Diem learning design process. We define social media as digital social tools and environments located outside of the provision of a formal university-provided Learning Management System. We use data collected via interviews and surveys with the MOOC participants as well as social media postings made by the participants throughout the MOOC to offer insights into how participants’ usage and perception of social media in their online learning experiences differed and why. We identified that, although some participants benefitted from social media by crediting it, for example, with networking and knowledge-sharing opportunities, others objected or refused to engage with social media, perceiving it as a waste of their time. We make recommendations for the usage of social media for educational purposes within MOOCs and formal digital learning environments.

  1. Incidental Learning of Melodic Structure of North Indian Music.

    Science.gov (United States)

    Rohrmeier, Martin; Widdess, Richard

    2017-07-01

    Musical knowledge is largely implicit. It is acquired without awareness of its complex rules, through interaction with a large number of samples during musical enculturation. Whereas several studies explored implicit learning of mostly abstract and less ecologically valid features of Western music, very little work has been done with respect to ecologically valid stimuli as well as non-Western music. The present study investigated implicit learning of modal melodic features in North Indian classical music in a realistic and ecologically valid way. It employed a cross-grammar design, using melodic materials from two modes (rāgas) that use the same scale. Findings indicated that Western participants unfamiliar with Indian music incidentally learned to identify distinctive features of each mode. Confidence ratings suggest that participants' performance was consistently correlated with confidence, indicating that they became aware of whether they were right in their responses; that is, they possessed explicit judgment knowledge. Altogether our findings show incidental learning in a realistic ecologically valid context during only a very short exposure, they provide evidence that incidental learning constitutes a powerful mechanism that plays a fundamental role in musical acquisition. Copyright © 2016 Cognitive Science Society, Inc.

  2. Developing Structured-Learning Exercises for a Community Advanced Pharmacy Practice Experience

    OpenAIRE

    Thomas, Renee Ahrens

    2006-01-01

    The recent growth in the number of pharmacy schools across the nation has resulted in the need for high-quality community advanced pharmacy practice experience (APPE) sites. A vital part of a student's education, these APPEs should be structured and formalized to provide an environment conducive to student learning. This paper discusses how to use a calendar, structured-learning activities, and scheduled evaluations to develop students' knowledge, skills, and abilities in a community pharmacy...

  3. Developing structured-learning exercises for a community advanced pharmacy practice experience.

    Science.gov (United States)

    Thomas, Renee Ahrens

    2006-02-15

    The recent growth in the number of pharmacy schools across the nation has resulted in the need for high-quality community advanced pharmacy practice experience (APPE) sites. A vital part of a student's education, these APPEs should be structured and formalized to provide an environment conducive to student learning. This paper discusses how to use a calendar, structured-learning activities, and scheduled evaluations to develop students' knowledge, skills, and abilities in a community pharmacy setting.

  4. Doing Dissections Differently: A Structured, Peer-Assisted Learning Approach to Maximizing Learning in Dissections

    Science.gov (United States)

    Hall, Emma R.; Davis, Rachel C.; Weller, Renate; Powney, Sonya; Williams, Sarah B.

    2013-01-01

    Areas of difficulty faced by our veterinary medicine students, with respect to their learning in dissection classes, were identified. These challenges were both general adult-learning related and specific to the discipline of anatomy. Our aim was to design, implement, and evaluate a modified reciprocal peer-assisted/team-based learning…

  5. Human capital and human resource management to achieve ambidextrous learning: A structural perspective

    Directory of Open Access Journals (Sweden)

    Mirta Diaz-Fernandez

    2017-01-01

    Full Text Available Organisational learning has become increasingly important for strategic renewal. Ambidextrous organisations are especially successful in the current environment, where firms are required to be efficient and adapt to change. Using a structural approach, this study discusses arguments about the nature of ambidexterity and identifies the kinds of human capital that better support specific learning types and HRM practices suited to these components of human capital. Results highlight learning differences between marketing and production units, as well as different HRM practices and human capital orientations. This study points out that human capital mediates between HRM practices and learning.

  6. Adaptive structured dictionary learning for image fusion based on group-sparse-representation

    Science.gov (United States)

    Yang, Jiajie; Sun, Bin; Luo, Chengwei; Wu, Yuzhong; Xu, Limei

    2018-04-01

    Dictionary learning is the key process of sparse representation which is one of the most widely used image representation theories in image fusion. The existing dictionary learning method does not use the group structure information and the sparse coefficients well. In this paper, we propose a new adaptive structured dictionary learning algorithm and a l1-norm maximum fusion rule that innovatively utilizes grouped sparse coefficients to merge the images. In the dictionary learning algorithm, we do not need prior knowledge about any group structure of the dictionary. By using the characteristics of the dictionary in expressing the signal, our algorithm can automatically find the desired potential structure information that hidden in the dictionary. The fusion rule takes the physical meaning of the group structure dictionary, and makes activity-level judgement on the structure information when the images are being merged. Therefore, the fused image can retain more significant information. Comparisons have been made with several state-of-the-art dictionary learning methods and fusion rules. The experimental results demonstrate that, the dictionary learning algorithm and the fusion rule both outperform others in terms of several objective evaluation metrics.

  7. Felder-Soloman's Index of Learning Styles: internal consistency, temporal stability, and factor structure.

    Science.gov (United States)

    Hosford, Charles C; Siders, William A

    2010-10-01

    Strategies to facilitate learning include using knowledge of students' learning style preferences to inform students and their teachers. Aims of this study were to evaluate the factor structure, internal consistency, and temporal stability of medical student responses to the Index of Learning Styles (ILS) and determine its appropriateness as an instrument for medical education. The ILS assesses preferences on four dimensions: sensing/intuitive information perceiving, visual/verbal information receiving, active/reflective information processing, and sequential/global information understanding. Students entering the 2002-2007 classes completed the ILS; some completed the ILS again after 2 and 4 years. Analyses of responses supported the ILS's intended structure and moderate reliability. Students had moderate preferences for sensing and visual learning. This study provides evidence supporting the appropriateness of the ILS for assessing learning style preferences in medical students.

  8. Seasonal variation and solar activity dependence of the quiet-time ionospheric trough

    Science.gov (United States)

    Ishida, T.; Ogawa, Y.; Kadokura, A.; Hiraki, Y.; Häggström, I.

    2014-08-01

    We have conducted a statistical analysis of the ionospheric F region trough, focusing on its seasonal variation and solar activity dependence under geomagnetically quiet and moderate conditions, using plasma parameter data obtained via Common Program 3 observations performed by the European Incoherent Scatter (EISCAT) radar between 1982 and 2011. We have confirmed that there is a major difference in frictional heating between the high- and low-latitude sides of the EISCAT field of view (FOV) at ~73°0'N-60°5'N (geomagnetic latitude) at an altitude of 325 km, which is associated with trough formation. Our statistical results show that the high-latitude and midlatitude troughs occur on the high- and low-latitude sides of the FOV, respectively. Seasonal variations indicate that dissociative recombination accompanied by frictional heating is a main cause of trough formation in sunlit regions. During summer, therefore, the occurrence rate is maintained at 80-90% in the postmidnight high-latitude region owing to frictional heating by eastward return flow. Solar activity dependence on trough formation indicates that field-aligned currents modulate the occurrence rate of the trough during the winter and equinox seasons. In addition, the trough becomes deeper via dissociative recombination caused by an increased ion temperature with F10.7, at least in the equinox and summer seasons but not in winter.

  9. Perceptual Organization of Visual Structure Requires a Flexible Learning Mechanism

    Science.gov (United States)

    Aslin, Richard N.

    2011-01-01

    Bhatt and Quinn (2011) provide a compelling and comprehensive review of empirical evidence that supports the operation of principles of perceptual organization in young infants. They also have provided a comprehensive list of experiences that could serve to trigger the learning of at least some of these principles of perceptual organization, and…

  10. Learning the Structure of English by Means of Esperanto.

    Science.gov (United States)

    Jones, R. Kent

    The Esperanto language was consciously designed as a coherent system, in contrast to the 3000 conventional languages originated by people's cave-dwelling ancestors. The systematic nature of Esperanto makes it ideal as an instructional tool. The amorphous nature of English makes its serious use very difficult for students. Even though they learn to…

  11. Learning within Incoherent Structures: The Space of Online Discussion Forums.

    Science.gov (United States)

    Thomas, Matthew J. W.

    2002-01-01

    Presents results from a study of undergraduate students' learning outcomes and patterns of interaction within an online discussion forum. Topics include social dynamics of computer-mediated communication versus face-to-face communication; cognitive engagement; critical and reflective thinking; and student interaction. (Author/LRW)

  12. The Web-Driven Learning Ecosystem: Its Structure and Benefits

    Science.gov (United States)

    Raska, David; Shaw, Doris; Keller, Eileen Weisenbach

    2012-01-01

    We have devised a Web-based learning ecosystem (LECOS) that aligns marketing curriculum, course design, technology, instructors, students, as well as external stakeholders--a system that integrates traditional teaching methods with technological advancements in an attempt to enhance marketing students' motivation, engagement, and performance. A…

  13. Calprotectin and TNF trough serum levels identify power Doppler ultrasound synovitis in rheumatoid arthritis and psoriatic arthritis patients in remission or with low disease activity.

    Science.gov (United States)

    Inciarte-Mundo, José; Ramirez, Julio; Hernández, Maria Victoria; Ruiz-Esquide, Virginia; Cuervo, Andrea; Cabrera-Villalba, Sonia Raquel; Pascal, Mariona; Yagüe, Jordi; Cañete, Juan D; Sanmarti, Raimon

    2016-07-08

    Serum levels of calprotectin, a major S100 leucocyte protein, are associated with disease activity in rheumatoid arthritis (RA) and psoriatic arthritis (PsA) patients. Higher drug trough serum levels are associated with good response in patients treated with tumour necrosis factor inhibitors (TNFi). Power Doppler ultrasound (PDUS) synovitis is predictive of flare and progression of structural damage in patients in clinical remission. The purpose of this study was to analyse the accuracy of calprotectin and TNFi trough serum levels in detecting PDUS synovitis in RA and PsA patients in clinical remission or with low disease activity who were receiving TNFi. We conducted a cross-sectional study of 92 patients (42 with RA, 50 with PsA) receiving adalimumab (ADA), etanercept (ETN) or infliximab who were in remission or had low disease activity (28-joint Disease Activity Score based on erythrocyte sedimentation rate ultrasound scores (all r coefficients >0.50 in RA). Calprotectin correlated with the PDUS synovitis score in patients treated with ADA and ETN. Using PDUS synovitis (yes or no) as the reference variable, calprotectin had an AUC of 0.826. The best cut-off was ≥1.66 μg/ml, with a likelihood ratio of 2.77. C-reactive protein (AUC 0.673) and erythrocyte sedimentation rate (AUC 0.731) had a lower discriminatory capacity. TNFi trough serum levels were significantly associated with PDUS synovitis (OR 0.67, 95 % CI 0.52-0.85, p < 0.001) but their accuracy (AUC <0.5) was less than that of calprotectin. TNFi trough serum levels were inversely correlated with calprotectin and PDUS synovitis in RA and PsA patients receiving ADA and ETN. Calprotectin and TNFi trough serum levels may help identify PDUS synovitis in RA and PsA patients in clinical remission or with low disease activity.

  14. Vancomycin AUC/MIC and Corresponding Troughs in a Pediatric Population.

    Science.gov (United States)

    Kishk, Omayma A; Lardieri, Allison B; Heil, Emily L; Morgan, Jill A

    2017-01-01

    Adult guidelines suggest an area under the curve/minimum inhibitory concentration (AUC/MIC) > 400 corresponds to a vancomycin trough serum concentration of 15 to 20 mg/L for methicillin-resistant Staphylococcus aureus infections, but obtaining these troughs in children are difficult. The primary objective of this study was to assess the likelihood that 15 mg/kg of vancomycin every 6 hours in a child achieves an AUC/MIC > 400. This retrospective chart review included pediatric patients >2 months to AUCs were calculated four times using three pharmacokinetic methods. A total of 36 patients with 99 vancomycin trough serum concentrations were assessed. Baseline characteristics were similar between groups. For troughs in group 1 (n = 55), the probability of achieving an AUC/MIC > 400 ranged from 16.4% to 90.9% with a median trough concentration of 11.4 mg/L, while in group 2 (n = 44) the probability of achieving AUC/MIC > 400 ranged from 15.9% to 54.5% with mean trough concentration of 9.2 mg/L. The AUC/MICs were not similar between the different pharmacokinetic methods used; however, a trapezoidal equation (Method A) yielded the highest correlation coefficient (r 2 = 0.59). When dosing every 6 hours, an AUC/MIC of 400 correlated to a trough serum concentration of 11 mg/L. The probability of achieving an AUC/MIC > 400 using only a trough serum concentration and an MIC with patients receiving 15 mg/kg every 6 hours is variable based on the method used to calculate the AUC. An AUC/MIC of 400 in children correlated to a trough concentration of 11 mg/L using a trapezoidal Method to calculate AUC.

  15. Parabolic Trough Collector Cost Update for the System Advisor Model (SAM)

    Energy Technology Data Exchange (ETDEWEB)

    Kurup, Parthiv [National Renewable Energy Lab. (NREL), Golden, CO (United States); Turchi, Craig S. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-11-01

    This report updates the baseline cost for parabolic trough solar fields in the United States within NREL's System Advisor Model (SAM). SAM, available at no cost at https://sam.nrel.gov/, is a performance and financial model designed to facilitate decision making for people involved in the renewable energy industry. SAM is the primary tool used by NREL and the U.S. Department of Energy (DOE) for estimating the performance and cost of concentrating solar power (CSP) technologies and projects. The study performed a bottom-up build and cost estimate for two state-of-the-art parabolic trough designs -- the SkyTrough and the Ultimate Trough. The SkyTrough analysis estimated the potential installed cost for a solar field of 1500 SCAs as $170/m2 +/- $6/m2. The investigation found that SkyTrough installed costs were sensitive to factors such as raw aluminum alloy cost and production volume. For example, in the case of the SkyTrough, the installed cost would rise to nearly $210/m2 if the aluminum alloy cost was $1.70/lb instead of $1.03/lb. Accordingly, one must be aware of fluctuations in the relevant commodities markets to track system cost over time. The estimated installed cost for the Ultimate Trough was only slightly higher at $178/m2, which includes an assembly facility of $11.6 million amortized over the required production volume. Considering the size and overall cost of a 700 SCA Ultimate Trough solar field, two parallel production lines in a fully covered assembly facility, each with the specific torque box, module and mirror jigs, would be justified for a full CSP plant.

  16. Weak lensing by galaxy troughs with modified gravity

    Energy Technology Data Exchange (ETDEWEB)

    Barreira, Alexandre [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching (Germany); Bose, Sownak; Li, Baojiu; Llinares, Claudio, E-mail: barreira@mpa-garching.mpg.de, E-mail: sownak.bose@durham.ac.uk, E-mail: baojiu.li@durham.ac.uk, E-mail: claudio.llinares@durham.ac.uk [Institute for Computational Cosmology, Durham University, South Road DH1 3LE, Durham (United Kingdom)

    2017-02-01

    We study the imprints that theories of gravity beyond GR can leave on the lensing signal around line of sight directions that are predominantly halo-underdense (called troughs) and halo-overdense. To carry out our investigations, we consider the normal branch of DGP gravity, as well as a phenomenological variant thereof that directly modifies the lensing potential. The predictions of these models are obtained with N-body simulation and ray-tracing methods using the ECOSMOG and Ray-Ramses codes. We analyse the stacked lensing convergence profiles around the underdense and overdense lines of sight, which exhibit, respectively, a suppression and a boost w.r.t. the mean in the field of view. The modifications to gravity in these models strengthen the signal w.r.t. ΛCDM in a scale-independent way. We find that the size of this effect is the same for both underdense and overdense lines of sight, which implies that the density field along the overdense directions on the sky is not sufficiently evolved to trigger the suppression effects of the screening mechanism. These results are robust to variations in the minimum halo mass and redshift ranges used to identify the lines of sight, as well as to different line of sight aperture sizes and criteria for their underdensity and overdensity thresholds.

  17. Risk factors associated with high linezolid trough plasma concentrations.

    Science.gov (United States)

    Morata, L; De la Calle, C; Gómez-Cerquera, J M; Manzanedo, L; Casals, G; Brunet, M; Cobos-Trigueros, N; Martínez, J A; Mensa, J; Soriano, A

    2016-06-01

    The major concern of linezolid is the adverse events. High linezolid trough serum concentration (Cmin) has been associated with toxicity. The aim of this study was to analyze factors associated with high Cmin. Main clinical characteristics of 104 patients treated with 600 mg/12 hours of linezolid were retrospectively reviewed. Samples were obtained just before the next dose after at least three doses and within the first 8 days of treatment. High Cmin was considered when it was >8 mg/L. Univariate and multivariate analysis were performed. 34.6% patients had a Cmin >8 mg/L, and they were older and had more frequently an estimated glomerular filtration by MDRD 8 was the renal function. Patients with an eGF 80 mL/min (OR: 4.273) and there was a trend towards a high Cmin in patients with eGF between 40-80 mL/min (OR: 2.109). High Cmin were frequent, especially in patients with MDRD <40 mL/min. Therapeutic drug monitoring could be useful to avoid toxicity in patients with renal dysfunction.

  18. PROMOTING GENDER EQUALITY TROUGH EQUAL LIFE STANDARD IN EU COUNTRIES

    Directory of Open Access Journals (Sweden)

    Aleksandar Dashtevski

    2018-06-01

    Full Text Available After the World War II, especially in the early fifties there is an expansion of gender rights. Women are massively employed all over the world in all sectors of social life, contributing to an increase in both their own standard of living and the standard in their own countries. As the importance and role of women grows, this is achieved with increasing respect for its rights. Gender means elimination of inequality and promote equality between women and men in all areas of social life. If we want to achieve gender equality as a whole, it is inevitable to achieve an economic consolidation of the two sexes. Economic strengthening is possible trough equal pay. Experience shows that payments are not equal when it comes to wages for men and women. Therefore, the EU is constantly working to regulate this area, with special regulations, which are mandatory for the member states, but should also be respected by countries that would like to join the union. This led to the promotion of gender equality through an equal life.

  19. Control concepts for direct steam generation in parabolic troughs

    Energy Technology Data Exchange (ETDEWEB)

    Valenzuela, Loreto; Zarza, Eduardo [CIEMAT, Plataforma Solar de Almeria, Tabernas (Almeria) (Spain); Berenguel, Manuel [Universidad de Almeria, Dept. de Lenguajes y Computacion, Almeria (Spain); Camacho, Eduardo F. [Universidad de Sevilla, Dept. de Ingenieria de Sistemas y Automatica, Sevilla (Spain)

    2005-02-01

    A new prototype parabolic-trough collector system was erected at the Plataforma Solar de Almeria (PSA) (1996-1998) to investigate direct steam generation (DSG) in a solar thermal power plant under real solar conditions. The system has been under evaluation for efficiency, cost, control and other parameters since 1999. The main objective of the control system is to obtain steam at constant temperature and pressure at the solar field outlet, so that changes in inlet water conditions and/or in solar radiation affect the amount of steam, but not its quality or the nominal plant efficiency. This paper presents control schemes designed and tested for two operating modes, 'Recirculation', for which a proportional-integral-derivative (PI/PID) control functions scheme has been implemented, and 'Once-through', requiring more complex control strategies, for which the scheme is based on proportional-integral (PI), feedforward and cascade control. Experimental results of both operation modes are discussed. (Author)

  20. Human reinforcement learning subdivides structured action spaces by learning effector-specific values

    OpenAIRE

    Gershman, Samuel J.; Pesaran, Bijan; Daw, Nathaniel D.

    2009-01-01

    Humans and animals are endowed with a large number of effectors. Although this enables great behavioral flexibility, it presents an equally formidable reinforcement learning problem of discovering which actions are most valuable, due to the high dimensionality of the action space. An unresolved question is how neural systems for reinforcement learning – such as prediction error signals for action valuation associated with dopamine and the striatum – can cope with this “curse of dimensionality...

  1. Human reinforcement learning subdivides structured action spaces by learning effector-specific values.

    Science.gov (United States)

    Gershman, Samuel J; Pesaran, Bijan; Daw, Nathaniel D

    2009-10-28

    Humans and animals are endowed with a large number of effectors. Although this enables great behavioral flexibility, it presents an equally formidable reinforcement learning problem of discovering which actions are most valuable because of the high dimensionality of the action space. An unresolved question is how neural systems for reinforcement learning-such as prediction error signals for action valuation associated with dopamine and the striatum-can cope with this "curse of dimensionality." We propose a reinforcement learning framework that allows for learned action valuations to be decomposed into effector-specific components when appropriate to a task, and test it by studying to what extent human behavior and blood oxygen level-dependent (BOLD) activity can exploit such a decomposition in a multieffector choice task. Subjects made simultaneous decisions with their left and right hands and received separate reward feedback for each hand movement. We found that choice behavior was better described by a learning model that decomposed the values of bimanual movements into separate values for each effector, rather than a traditional model that treated the bimanual actions as unitary with a single value. A decomposition of value into effector-specific components was also observed in value-related BOLD signaling, in the form of lateralized biases in striatal correlates of prediction error and anticipatory value correlates in the intraparietal sulcus. These results suggest that the human brain can use decomposed value representations to "divide and conquer" reinforcement learning over high-dimensional action spaces.

  2. High School Students' Epistemological Beliefs, Conceptions of Learning, and Self-Efficacy for Learning Biology: A Study of Their Structural Models

    Science.gov (United States)

    Sadi, Özlem; Dagyar, Miray

    2015-01-01

    The current work reveals the data of the study which examines the relationships among epistemological beliefs, conceptions of learning, and self-efficacy for biology learning with the help of the Structural Equation Modeling. Three questionnaires, the Epistemological Beliefs, the Conceptions of Learning Biology and the Self-efficacy for Learning…

  3. Human infants' learning of social structures: the case of dominance hierarchy.

    Science.gov (United States)

    Mascaro, Olivier; Csibra, Gergely

    2014-01-01

    We tested 15-month-olds' capacity to represent social-dominance hierarchies with more than two agents. Our results showed that infants found it harder to memorize dominance relations that were presented in an order that hindered the incremental formation of a single structure (Study 1). These results suggest that infants attempt to build structures incrementally, relation by relation, thereby simplifying the complex problem of recognizing a social structure. Infants also found circular dominance structures harder to process than linear dominance structures (Study 2). These expectations about the shape of structures may facilitate learning. Our results suggest that infants attempt to represent social structures composed of social relations. They indicate that human infants go beyond learning about individual social partners and their respective relations and form hypotheses about how social groups are organized.

  4. An Analysis of the Relationship between the Learning Process and Learning Motivation Profiles of Japanese Pharmacy Students Using Structural Equation Modeling

    Directory of Open Access Journals (Sweden)

    Shigeo Yamamura

    2018-04-01

    Full Text Available Pharmacy students in Japan have to maintain strong motivation to learn for six years during their education. The authors explored the students’ learning structure. All pharmacy students in their 4th through to 6th year at Josai International University participated in the survey. The revised two factor study process questionnaire and science motivation questionnaire II were used to assess their learning process and learning motivation profiles, respectively. Structural equation modeling (SEM was used to examine a causal relationship between the latent variables in the learning process and those in the learning motivation profile. The learning structure was modeled on the idea that the learning process affects the learning motivation profile of respondents. In the multi-group SEM, the estimated mean of the deep learning to learning motivation profile increased just after their clinical clerkship for 6th year students. This indicated that the clinical experience benefited students’ deep learning, which is probably because the experience of meeting with real patients encourages meaningful learning in pharmacy studies.

  5. An Analysis of the Relationship between the Learning Process and Learning Motivation Profiles of Japanese Pharmacy Students Using Structural Equation Modeling.

    Science.gov (United States)

    Yamamura, Shigeo; Takehira, Rieko

    2018-04-23

    Pharmacy students in Japan have to maintain strong motivation to learn for six years during their education. The authors explored the students’ learning structure. All pharmacy students in their 4th through to 6th year at Josai International University participated in the survey. The revised two factor study process questionnaire and science motivation questionnaire II were used to assess their learning process and learning motivation profiles, respectively. Structural equation modeling (SEM) was used to examine a causal relationship between the latent variables in the learning process and those in the learning motivation profile. The learning structure was modeled on the idea that the learning process affects the learning motivation profile of respondents. In the multi-group SEM, the estimated mean of the deep learning to learning motivation profile increased just after their clinical clerkship for 6th year students. This indicated that the clinical experience benefited students’ deep learning, which is probably because the experience of meeting with real patients encourages meaningful learning in pharmacy studies.

  6. The Relative Effects of Alternative Learning Structures on Attitudes and Achievements.

    Science.gov (United States)

    Carifio, James

    This study compared two learning structures for an introductory course in tests and measurements in terms of their relative effects on attitudes and achievement. The first structure represented a functionally arranged instructional sequence (FAIS). The second represented a psychologically arranged instructional sequence (PAIS). The instructional…

  7. The Influence of the Organizational Structures of Colleges and Universities on College Student Learning.

    Science.gov (United States)

    Berger, Joseph B.

    2002-01-01

    Reports the findings of a study conducted to determine the influence of various dimensions of organizational structure (bureaucratic, collegial, political, symbolic, and systemic) on college student learning. Findings indicate that dimensions of the structure of the colleges and universities as organizations exert both positive and negative…

  8. The factor structure of the self-directed learning readiness scale | de ...

    African Journals Online (AJOL)

    The factor structure of the Self-Directed Learning Readiness Scale (SDLRS) was investigated for Afrikaans and English-speaking first-year university students. Five factors were extracted and rotated to oblique simple structure for both groups. Four of the five factors were satisfactorily replicated. The fifth factor appeared to ...

  9. Patient-reported non-adherence and immunosuppressant trough levels are associated with rejection after renal transplantation.

    Science.gov (United States)

    Scheel, Jennifer; Reber, Sandra; Stoessel, Lisa; Waldmann, Elisabeth; Jank, Sabine; Eckardt, Kai-Uwe; Grundmann, Franziska; Vitinius, Frank; de Zwaan, Martina; Bertram, Anna; Erim, Yesim

    2017-03-29

    Different measures of non-adherence to immunosuppressant (IS) medication have been found to be associated with rejection episodes after successful transplantation. The aim of the current study was to investigate whether graft rejection after renal transplantation is associated with patient-reported IS medication non-adherence and IS trough level variables (IS trough level variability and percentage of sub-therapeutic IS trough levels). Patient-reported non-adherence, IS trough level variability, percentage of sub-therapeutic IS trough levels, and acute biopsy-proven late allograft rejections were assessed in 267 adult renal transplant recipients who were ≥12 months post-transplantation. The rate of rejection was 13.5%. IS trough level variability, percentage of sub-therapeutic IS trough levels as well as patient-reported non-adherence were all significantly and positively associated with rejection, but not with each other. Logistic regression analyses revealed that only the percentage of sub-therapeutic IS trough levels and age at transplantation remained significantly associated with rejection. Particularly, the percentage of sub-therapeutic IS trough levels is associated with acute rejections after kidney transplantation whereas IS trough level variability and patient-reported non-adherence seem to be of subordinate importance. Patient-reported non-adherence and IS trough level variables were not correlated; thus, non-adherence should always be measured in a multi-methodological approach. Further research concerning the best combination of non-adherence measures is needed.

  10. Digital Learning Characteristics and Principles of Information Resources Knowledge Structuring

    Science.gov (United States)

    Belichenko, Margarita; Davidovitch, Nitza; Kravchenko, Yuri

    2017-01-01

    Analysis of principles knowledge representation in information systems led to the necessity of improving the structuring knowledge. It is caused by the development of software component and new possibilities of information technologies. The article combines methodological aspects of structuring knowledge and effective usage of information…

  11. Temporal and Statistical Information in Causal Structure Learning

    Science.gov (United States)

    McCormack, Teresa; Frosch, Caren; Patrick, Fiona; Lagnado, David

    2015-01-01

    Three experiments examined children's and adults' abilities to use statistical and temporal information to distinguish between common cause and causal chain structures. In Experiment 1, participants were provided with conditional probability information and/or temporal information and asked to infer the causal structure of a 3-variable mechanical…

  12. Report on Radiocarbon Analysis of Surface Sediments from the Fore-Arc Basin of Nankai Trough

    National Research Council Canada - National Science Library

    Pohlman, John

    2004-01-01

    .... Radiocarbon analysis of the total organic carbon (TOC) and total inorganic carbon (TIC) on 30 sediment samples from two multicores and six piston cores was performed to investigate the fate of methane carbon in sediment of the Nankal Trough...

  13. Gas Turbine/Solar Parabolic Trough Hybrid Design Using Molten Salt Heat Transfer Fluid: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, C. S.; Ma, Z.

    2011-08-01

    Parabolic trough power plants can provide reliable power by incorporating either thermal energy storage (TES) or backup heat from fossil fuels. This paper describes a gas turbine / parabolic trough hybrid design that combines a solar contribution greater than 50% with gas heat rates that rival those of natural gas combined-cycle plants. Previous work illustrated benefits of integrating gas turbines with conventional oil heat-transfer-fluid (HTF) troughs running at 390?C. This work extends that analysis to examine the integration of gas turbines with salt-HTF troughs running at 450 degrees C and including TES. Using gas turbine waste heat to supplement the TES system provides greater operating flexibility while enhancing the efficiency of gas utilization. The analysis indicates that the hybrid plant design produces solar-derived electricity and gas-derived electricity at lower cost than either system operating alone.

  14. A geometric view on learning Bayesian network structures

    Czech Academy of Sciences Publication Activity Database

    Studený, Milan; Vomlel, Jiří; Hemmecke, R.

    2010-01-01

    Roč. 51, č. 5 (2010), s. 578-586 ISSN 0888-613X. [PGM 2008] R&D Projects: GA AV ČR(CZ) IAA100750603; GA MŠk(CZ) 1M0572; GA ČR GA201/08/0539 Grant - others:GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : learning Bayesian networks * standard imset * inclusion neighborhood * geometric neighborhood * GES algorithm Subject RIV: BA - General Mathematics Impact factor: 1.679, year: 2010 http://library.utia.cas.cz/separaty/2010/MTR/studeny-0342804. pdf

  15. A hierarchical model for structure learning based on the physiological characteristics of neurons

    Institute of Scientific and Technical Information of China (English)

    WEI Hui

    2007-01-01

    Almost all applications of Artificial Neural Networks (ANNs) depend mainly on their memory ability.The characteristics of typical ANN models are fixed connections,with evolved weights,globalized representations,and globalized optimizations,all based on a mathematical approach.This makes those models to be deficient in robustness,efficiency of learning,capacity,anti-jamming between training sets,and correlativity of samples,etc.In this paper,we attempt to address these problems by adopting the characteristics of biological neurons in morphology and signal processing.A hierarchical neural network was designed and realized to implement structure learning and representations based on connected structures.The basic characteristics of this model are localized and random connections,field limitations of neuron fan-in and fan-out,dynamic behavior of neurons,and samples represented through different sub-circuits of neurons specialized into different response patterns.At the end of this paper,some important aspects of error correction,capacity,learning efficiency,and soundness of structural representation are analyzed theoretically.This paper has demonstrated the feasibility and advantages of structure learning and representation.This model can serve as a fundamental element of cognitive systems such as perception and associative memory.Key-words structure learning,representation,associative memory,computational neuroscience

  16. Impact of convection over the equatorial trough on the summer monsoon activity over India

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.; Shenoi, S.S.C.; Schulz, J.

    . There have been studies (Cadet and Olory Togbe, 1981; Sadhuram and Sastry, 1987) on the role of Equatorial Trough (ET) as well as Southern Hemispheric Equatorial Trough (SHET) on the rainfall over central India. Most of these studies are related... the ET, WET and EET behave in a similar fashion during different monsoon and El Nino conditions ? c) What role do the synoptic systems play during the BM over the Indian subcontinent? 2. Data and Methodology The pentad precipitation data used...

  17. Performance comparison of solar parabolic trough system with glass and film reflector

    International Nuclear Information System (INIS)

    Xu, Qian; Li, Longlong; Li, Huairui; Huang, Weidong; Li, Yongping

    2014-01-01

    Highlights: • Solar trough model should consider refractive surface error with glass reflector. • Solar trough system with glass mirror has less efficiency than that with film mirror. • Solar trough system has very low efficiency in a winter day at high latitude. - Abstract: This paper considers the refractive surface error transfer process to present an optical performance model of solar trough system as well as the reflective surface error. We validate the optical model through comparing the calculation results with the experimental data. The optimized design parameters are presented based on the maximization of the annual average net heat efficiency. The results show that maximum relative error of 20% for the optical efficiency may produce if the refractive surface error transfer process is ignored. It indicates that the refractive surface error should be considered in predicting the performance of the solar trough system especially for the glass reflector as well as the reflective surface error. We apply the model to compare the performance of solar parabolic trough system with vacuum tube receiver under two kinds of reflectors, which are glass mirror and film mirror. The results indicate that both parabolic trough systems with a vacuum tube receiver and a north–south axis tracking system are relatively inefficient in winter days, and the net energy output in the winter solstice is less than one sixth of the summer. The net heat efficiency of solar trough system with film mirror is 50% less than that of the system with the glass mirror at noon of the winter solstice and latitude 40 if the design and parameter of the two systems are the same. The results indicate that film reflector is more preferable than glass reflector especially in high latitude if they have the same optical property

  18. Processes influencing differences in Arctic and Antarctic Trough Mouth Fan sedimentology

    OpenAIRE

    Gales, J; Hillenbrand, C-D; Larter, R; Laberg, J-S; Melles, M; Benetti, S; Passchier, S

    2018-01-01

    Trough Mouth Fans (TMFs) are sediment depocentres that form along high-latitude continental margins at the mouths of some cross-shelf troughs. They reflect the dynamics of past ice sheets over multiple glacial cycles and processes operating on (formerly) glaciated continental shelves and slopes, such as erosion, reworking, transport and deposition. The similarities and differences in TMF morphology and formation processes of the Arctic and Antarctic regions remain poorly constrained. Here, we...

  19. Learning the Structure of Bayesian Network from Small Amount of Data

    Directory of Open Access Journals (Sweden)

    Bogdan COCU

    2009-12-01

    Full Text Available Many areas of artificial intelligence must handling with imperfection ofinformation. One of the ways to do this is using representation and reasoning withBayesian networks. Creation of a Bayesian network consists in two stages. First stage isto design the node structure and directed links between them. Choosing of a structurefor network can be done either through empirical developing by human experts orthrough machine learning algorithm. The second stage is completion of probabilitytables for each node. Using a machine learning method is useful, especially when wehave a big amount of leaning data. But in many fields the amount of data is small,incomplete and inconsistent. In this paper, we make a case study for choosing the bestlearning method for small amount of learning data. Means more experiments we dropconclusion of using existent methods for learning a network structure.

  20. The effects of thick sediment upon continental breakup: seismic imaging and thermal modeling of the Salton Trough, southern California

    Science.gov (United States)

    Han, L.; Hole, J. A.; Lowell, R. P.; Stock, J. M.; Fuis, G. S.; Driscoll, N. W.; Kell, A. M.; Kent, G. M.; Harding, A. J.; Gonzalez-Fernandez, A.; Lázaro-Mancilla, O.

    2015-12-01

    Continental rifting ultimately creates a deep accommodation space for sediment. When a major river flows into a late-stage rift, thick deltaic sediment can change the thermal regime and alter the mechanisms of extension and continental breakup. The Salton Trough, the northernmost rift segment of the Gulf of California plate boundary, has experienced the same extension as the rest of the Gulf, but is filled to sea level by sediment from the Colorado River. Unlike the southern Gulf, seafloor spreading has not initiated. Instead, seismicity, high heat flow, and minor volcanoes attest to ongoing rifting of thin, transitional crust. Recently acquired controlled-source seismic refraction and wide-angle reflection data in the Salton Trough provide constraints upon crustal architecture and active rift processes. The crust in the central Salton Trough is only 17-18 km thick, with a strongly layered but relatively one-dimensional structure for ~100 km in the direction of plate motion. The upper crust includes 2-4 km of Colorado River sediment. Crystalline rock below the sediment is interpreted to be similar sediment metamorphosed by the high heat flow and geothermal activity. Meta-sediment extends to at least 9 km depth. A 4-5 km thick layer in the middle crust is either additional meta-sediment or stretched pre-existing continental crust. The lowermost 4-5 km of the crust is rift-related mafic magmatic intrusion or underplating from partial melting in the hot upper mantle. North American lithosphere in the Salton Trough has been almost or completely rifted apart. The gap has been filled by ~100 km of new transitional crust created by magmatism from below and sedimentation from above. These processes create strong lithologic, thermal, and rheologic layering. While heat flow in the rift is very high, rapid sedimentation cools the upper crust as compared to a linear geotherm. Brittle extension occurs within new meta-sedimentary rock. The lower crust, in comparison, is

  1. Efficient Exact Inference With Loss Augmented Objective in Structured Learning.

    Science.gov (United States)

    Bauer, Alexander; Nakajima, Shinichi; Muller, Klaus-Robert

    2016-08-19

    Structural support vector machine (SVM) is an elegant approach for building complex and accurate models with structured outputs. However, its applicability relies on the availability of efficient inference algorithms--the state-of-the-art training algorithms repeatedly perform inference to compute a subgradient or to find the most violating configuration. In this paper, we propose an exact inference algorithm for maximizing nondecomposable objectives due to special type of a high-order potential having a decomposable internal structure. As an important application, our method covers the loss augmented inference, which enables the slack and margin scaling formulations of structural SVM with a variety of dissimilarity measures, e.g., Hamming loss, precision and recall, Fβ-loss, intersection over union, and many other functions that can be efficiently computed from the contingency table. We demonstrate the advantages of our approach in natural language parsing and sequence segmentation applications.

  2. Optimising position control of a solar parabolic trough

    Directory of Open Access Journals (Sweden)

    Puramanathan Naidoo

    2011-03-01

    Full Text Available In today’s climate of growing energy needs and increasing environmental concerns, alternatives to the use of non-renewable and polluting fossil fuels have to be investigated. One such alternative is solar energy. This study is based on the implementation of a mathematical computation – the PSA (Plataforma Solar de Almeria computation developed at PSA (the European Test Centre for solar energy applications – embedded in a control algorithm to locate the position of the sun. Tests were conducted on a solar parabolic trough (SPT constructed at the Solar Thermal Applications Research Laboratory of the Mangosuthu University of Technology (Durban, South Africa for optimal position control using the PSA value. The designed control algorithm embedded in an industrial Siemens S7-314 C-2PtP programmable logic controller compared the PSA computation to a measured position of the SPT to optimally rotate the SPT to a desired position with the constant movement of the sun. The two main angles of the sun relative to the position of the SPT on earth, the zenith angle and the azimuth angle, both calculated in the PSA from the vertical and horizontal planes, respectively, were applied to the control algorithm to generate an appropriate final tracking angle within a 0.007 radian (0° 24′ 3.6″ tolerance, in accordance to the construction specifications and solar collector testing standards of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE, 1991. These values, together with the longitude and latitude applicable to the geographical location of the SPT, were processed in the control software to rotate the SPT to an optimal position with respect to the position of the sun in its daily path, for solar-to-thermal conversion.

  3. Heat transfer analysis of parabolic trough solar receiver

    International Nuclear Information System (INIS)

    Padilla, Ricardo Vasquez; Demirkaya, Gokmen; Goswami, D. Yogi; Stefanakos, Elias; Rahman, Muhammad M.

    2011-01-01

    Highlights: → In this paper a detailed one dimensional numerical heat transfer analysis of a PTC is performed. → The receiver and envelope were divided into several segments and mass and energy balance were applied in each segment. → Improvements either in the heat transfer correlations or radiative heat transfer analysis are presented. → The proposed heat transfer model was validated with experimental data obtained from Sandia National Laboratory. → Our results showed a better agreement with experimental data compared to other models. -- Abstract: Solar Parabolic Trough Collectors (PTCs) are currently used for the production of electricity and applications with relatively higher temperatures. A heat transfer fluid circulates through a metal tube (receiver) with an external selective surface that absorbs solar radiation reflected from the mirror surfaces of the PTC. In order to reduce the heat losses, the receiver is covered by an envelope and the enclosure is usually kept under vacuum pressure. The heat transfer and optical analysis of the PTC is essential to optimize and understand its performance under different operating conditions. In this paper a detailed one dimensional numerical heat transfer analysis of a PTC is performed. The receiver and envelope were divided into several segments and mass and energy balance were applied in each segment. Improvements either in the heat transfer correlations or radiative heat transfer analysis are presented as well. The partial differential equations were discretized and the nonlinear algebraic equations were solved simultaneously. Finally, to validate the numerical results, the model was compared with experimental data obtained from Sandia National Laboratory (SNL) and other one dimensional heat transfer models. Our results showed a better agreement with experimental data compared to other models.

  4. Performance and durability testing of parabolic trough receivers

    Science.gov (United States)

    Lei, Dongqiang; Fu, Xuqiang; Zhao, Dongming; Yuan, Guofeng; Wang, Zhifeng; Guo, Minghuan

    2017-06-01

    The paper describes the key performance and durability testing facilities of the parabolic trough receiver developed by Institute of Electrical Engineering, Chinese Academy of Sciences. The indoor heat loss test can be applied at 4-7 different temperature levels within 200-550 on receivers. The optical efficiency test bench consists of 12 metal halide lamps as the solar simulator and a 5 m length half-elliptical cylinder reflector with flat end reflectors. 3 ultra-precision temperature sensors are used in receiver each end to get the temperature difference. The residual gas analysis test bench is applied to analyze and predict the vacuum lifetime of the receiver. It can test the variations of composition and partial pressure of residual gases with temperature and time in the receiver annulus space by a high sensitivity quadrupole mass spectrometer gas analyzer. A coating accelerated ageing test bench, which is also used to test the thermal cycle, has been developed. This test bench uses the absorber tube of the recevier as the resistance heater to heat up the whole receiver. The coating lifetime can be predicted by the Arrhenius parameters. For the cycling test, the compressed air is used to directly cool the inner surface of the absorber tube. The thermal cycling test is performed with temperature cycles from 150 °C to 450 °C for 160 cycles. The maximum thermal cycling frequency is 8 cycles per day. The mechanical fatigue test bench is used to test the bellows and the glass-to-metal seals durability at the same time. Both bellows are expanded and compressed to 6.5 mm in turn with 10,000 cycles. A new rotating test bench was also developed to test the thermal efficiency of the receiver.

  5. Marginal space learning for medical image analysis efficient detection and segmentation of anatomical structures

    CERN Document Server

    Zheng, Yefeng

    2014-01-01

    Presents an award winning image analysis technology (Thomas Edison Patent Award, MICCAI Young Investigator Award) that achieves object detection and segmentation with state-of-the-art accuracy and efficiency Flexible, machine learning-based framework, applicable across multiple anatomical structures and imaging modalities Thirty five clinical applications on detecting and segmenting anatomical structures such as heart chambers and valves, blood vessels, liver, kidney, prostate, lymph nodes, and sub-cortical brain structures, in CT, MRI, X-Ray and Ultrasound.

  6. The role of training structure in perceptual learning of accented speech.

    Science.gov (United States)

    Tzeng, Christina Y; Alexander, Jessica E D; Sidaras, Sabrina K; Nygaard, Lynne C

    2016-11-01

    Foreign-accented speech contains multiple sources of variation that listeners learn to accommodate. Extending previous findings showing that exposure to high-variation training facilitates perceptual learning of accented speech, the current study examines to what extent the structure of training materials affects learning. During training, native adult speakers of American English transcribed sentences spoken in English by native Spanish-speaking adults. In Experiment 1, training stimuli were blocked by speaker, sentence, or randomized with respect to speaker and sentence (Variable training). At test, listeners transcribed novel English sentences produced by unfamiliar Spanish-accented speakers. Listeners' transcription accuracy was highest in the Variable condition, suggesting that varying both speaker identity and sentence across training trials enabled listeners to generalize their learning to novel speakers and linguistic content. Experiment 2 assessed the extent to which ordering of training tokens by a single factor, speaker intelligibility, would facilitate speaker-independent accent learning, finding that listeners' test performance did not reliably differ from that in the no-training control condition. Overall, these results suggest that the structure of training exposure, specifically trial-to-trial variation on both speaker's voice and linguistic content, facilitates learning of the systematic properties of accented speech. The current findings suggest a crucial role of training structure in optimizing perceptual learning. Beyond characterizing the types of variation listeners encode in their representations of spoken utterances, theories of spoken language processing should incorporate the role of training structure in learning lawful variation in speech. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  7. Collaborative Education Practice in a Data Structure E-Learning Course

    OpenAIRE

    Gang Chen; Ruimin Shen

    2009-01-01

    This paper presented a collaborative education model, which consists four parts: collaborative teaching, collaborative working, collaborative training and interaction. Supported by an e-learning platform, collaborative education was practiced in a data structure e-learning course. Data collected shows that most of students accept collaborative education. This paper goes one step attempting to determine which aspects appear to be most important or helpful in collaborative ...

  8. A semi-supervised learning approach for RNA secondary structure prediction.

    Science.gov (United States)

    Yonemoto, Haruka; Asai, Kiyoshi; Hamada, Michiaki

    2015-08-01

    RNA secondary structure prediction is a key technology in RNA bioinformatics. Most algorithms for RNA secondary structure prediction use probabilistic models, in which the model parameters are trained with reliable RNA secondary structures. Because of the difficulty of determining RNA secondary structures by experimental procedures, such as NMR or X-ray crystal structural analyses, there are still many RNA sequences that could be useful for training whose secondary structures have not been experimentally determined. In this paper, we introduce a novel semi-supervised learning approach for training parameters in a probabilistic model of RNA secondary structures in which we employ not only RNA sequences with annotated secondary structures but also ones with unknown secondary structures. Our model is based on a hybrid of generative (stochastic context-free grammars) and discriminative models (conditional random fields) that has been successfully applied to natural language processing. Computational experiments indicate that the accuracy of secondary structure prediction is improved by incorporating RNA sequences with unknown secondary structures into training. To our knowledge, this is the first study of a semi-supervised learning approach for RNA secondary structure prediction. This technique will be useful when the number of reliable structures is limited. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. COGNITIVE LEARNING STRATEGIES OF NON-ENGLISH DEPARTMENT STUDENTS ON NOUN STRUCTURE

    Directory of Open Access Journals (Sweden)

    Shierly Novalita Yappy

    2006-01-01

    Full Text Available Learning English for non-English department students is not as easy as it seems. Besides, as much as it is necessary to know how successful learners learn, not less important is to know how less successful learners learn. Using think aloud method, this study aims at finding out the cognitive strategies used by the engineering department students in answering incorrectly problems on TOEFL noun structure-the grammar point in which students made the most errors. Findings uncover the students' strategies and reasoning upon which pedagogical implications can be put forth so that more effective and fruitful instruction can be tailored.

  10. Using enterprise architecture to analyse how organisational structure impact motivation and learning

    Science.gov (United States)

    Närman, Pia; Johnson, Pontus; Gingnell, Liv

    2016-06-01

    When technology, environment, or strategies change, organisations need to adjust their structures accordingly. These structural changes do not always enhance the organisational performance as intended partly because organisational developers do not understand the consequences of structural changes in performance. This article presents a model-based analysis framework for quantitative analysis of the effect of organisational structure on organisation performance in terms of employee motivation and learning. The model is based on Mintzberg's work on organisational structure. The quantitative analysis is formalised using the Object Constraint Language (OCL) and the Unified Modelling Language (UML) and implemented in an enterprise architecture tool.

  11. All together now: concurrent learning of multiple structures in an artificial language.

    Science.gov (United States)

    Romberg, Alexa R; Saffran, Jenny R

    2013-01-01

    Natural languages contain many layers of sequential structure, from the distribution of phonemes within words to the distribution of phrases within utterances. However, most research modeling language acquisition using artificial languages has focused on only one type of distributional structure at a time. In two experiments, we investigated adult learning of an artificial language that contains dependencies between both adjacent and non-adjacent words. We found that learners rapidly acquired both types of regularities and that the strength of the adjacent statistics influenced learning of both adjacent and non-adjacent dependencies. Additionally, though accuracy was similar for both types of structure, participants' knowledge of the deterministic non-adjacent dependencies was more explicit than their knowledge of the probabilistic adjacent dependencies. The results are discussed in the context of current theories of statistical learning and language acquisition. © 2013 Cognitive Science Society, Inc.

  12. Upper-Lower Bounds Candidate Sets Searching Algorithm for Bayesian Network Structure Learning

    Directory of Open Access Journals (Sweden)

    Guangyi Liu

    2014-01-01

    Full Text Available Bayesian network is an important theoretical model in artificial intelligence field and also a powerful tool for processing uncertainty issues. Considering the slow convergence speed of current Bayesian network structure learning algorithms, a fast hybrid learning method is proposed in this paper. We start with further analysis of information provided by low-order conditional independence testing, and then two methods are given for constructing graph model of network, which is theoretically proved to be upper and lower bounds of the structure space of target network, so that candidate sets are given as a result; after that a search and scoring algorithm is operated based on the candidate sets to find the final structure of the network. Simulation results show that the algorithm proposed in this paper is more efficient than similar algorithms with the same learning precision.

  13. STRUCTURAL AND FUNCTIONAL MODEL OF CLOUD ORIENTED LEARNING ENVIRONMENT FOR BACHELORS OF INFORMATICS TRAINING

    Directory of Open Access Journals (Sweden)

    Tetiana A. Vakaliuk

    2017-06-01

    Full Text Available The article summarizes the essence of the category "model". There are presented the main types of models used in educational research: structural, functional, structural and functional model as well as basic requirements for building these types of models. The national experience in building models and designing cloud-based learning environment of educational institutions (both higher and secondary is analyzed. It is presented structural and functional model of cloud-based learning environment for Bachelor of Informatics. Also we describe each component of cloud-based learning environment model for bachelors of informatics training: target, managerial, organizational, content and methodical, communication, technological and productive. It is summarized, that COLE should solve all major tasks that relate to higher education institutions.

  14. The impact of category structure and training methodology on learning and generalizing within-category representations.

    Science.gov (United States)

    Ell, Shawn W; Smith, David B; Peralta, Gabriela; Hélie, Sébastien

    2017-08-01

    When interacting with categories, representations focused on within-category relationships are often learned, but the conditions promoting within-category representations and their generalizability are unclear. We report the results of three experiments investigating the impact of category structure and training methodology on the learning and generalization of within-category representations (i.e., correlational structure). Participants were trained on either rule-based or information-integration structures using classification (Is the stimulus a member of Category A or Category B?), concept (e.g., Is the stimulus a member of Category A, Yes or No?), or inference (infer the missing component of the stimulus from a given category) and then tested on either an inference task (Experiments 1 and 2) or a classification task (Experiment 3). For the information-integration structure, within-category representations were consistently learned, could be generalized to novel stimuli, and could be generalized to support inference at test. For the rule-based structure, extended inference training resulted in generalization to novel stimuli (Experiment 2) and inference training resulted in generalization to classification (Experiment 3). These data help to clarify the conditions under which within-category representations can be learned. Moreover, these results make an important contribution in highlighting the impact of category structure and training methodology on the generalization of categorical knowledge.

  15. Structure Learning in Stochastic Non-linear Dynamical Systems

    Science.gov (United States)

    Morris, R. D.; Smelyanskiy, V. N.; Luchinsky, D. G.

    2005-12-01

    A great many systems can be modeled in the non-linear dynamical systems framework, as x˙ = f(x) + ξ(t), where f(x) is the potential function for the system, and ξ(t) is the driving noise. Modeling the potential using a set of basis functions, we derive the posterior for the basis coefficients. A more challenging problem is to determine the set of basis functions that are required to model a particular system. We show that using the Bayesian Information Criteria (BIC) to rank models, and the beam search technique, that we can accurately determine the structure of simple non-linear dynamical system models, and the structure of the coupling between non-linear dynamical systems where the individual systems are known. This last case has important ecological applications, for example in predator-prey systems, where the very structure of the coupling between predator-prey pairs can have great ecological significance.

  16. Investigating the Structural Relationships among Organisational Support, Learning Flow, Learners' Satisfaction and Learning Transfer in Corporate E-Learning

    Science.gov (United States)

    Joo, Young Ju; Lim, Kyu Yon; Park, Su Yeong

    2011-01-01

    E-learning in corporate training has been growing rapidly because of the pursuit of time and budget efficiency in course development and delivery. However, according to previous studies, efficiency does not always guarantee training effectiveness, which is the major concern of human resource development. It is therefore necessary to identify the…

  17. What can we learn from polarized structure function data?

    CERN Document Server

    Ball, Richard D.; Altarelli, Guido; Forte, Stefano; Ball, Richard D.; Ridolfi, Giovanni; Altarelli, Guido; Forte, Stefano

    1997-04-20

    We summarise the perturbative QCD analysis of the structure function data for g_1 from longitudinally polarized deep inelastic scattering from proton, deuteron and neutron targets, with particular emphasis on testing sum rules, determining helicity fractions, and extracting the strong coupling from both scaling violations and the Bjorken sum rule.

  18. Learning Molecular Structures in a Tangible Augmented Reality Environment

    Science.gov (United States)

    Asai, Kikuo; Takase, Norio

    2011-01-01

    This article presents the characteristics of using a tangible table top environment produced by augmented reality (AR), aimed at improving the environment in which learners observe three-dimensional molecular structures. The authors perform two evaluation experiments. A performance test for a user interface demonstrates that learners with a…

  19. What Can We Learn from the Crystal Structures of Metallacarboranes?

    Directory of Open Access Journals (Sweden)

    Alan J. Welch

    2017-07-01

    Full Text Available The determination of the molecular structures of metallacarboranes by X-ray diffraction remains critical to the development of the field, in some cases being the only viable way in which the overall architecture and the isomeric form of the molecule can be established. In such studies one problem frequently met is how to distinguish correctly {BH} and {CH} vertices, and this review begins by describing two relatively new methods, the Vertex-Centroid Distance (VCD and Boron-Hydrogen Distance (BHD methods, that have been developed to overcome the problem. Once the cage C atoms are located correctly, the resulting metallacarborane structure can frequently be analysed on the basis that cage B has a greater Structural Trans Effect (STE than does cage C. In the absence of significant competing effects this gives rise to unequal M–L distances for a homogeneous ligand set and to a preferred Exopolyhedral Ligand Orientation (ELO for a heterogeneous ligand set. ELO considerations can be used, amongst other things, to rank order the STEs of ligands and to identify suspect (in terms of cage C atom positions metallacarborane structures.

  20. Discussion Tool Effects on Collaborative Learning and Social Network Structure

    Science.gov (United States)

    Tomsic, Astrid; Suthers, Daniel D.

    2006-01-01

    This study investigated the social network structure of booking officers at the Honolulu Police Department and how the introduction of an online discussion tool affected knowledge about operation of a booking module. Baseline data provided evidence for collaboration among officers in the same district using e-mail, telephone and face-to-face media…

  1. [Perceptions of classroom goal structures, personal achievement goal orientations, and learning strategies].

    Science.gov (United States)

    Miki, Kaori; Yamauchi, Hirotsugu

    2005-08-01

    We examined the relations among students' perceptions of classroom goal structures (mastery and performance goal structures), students' achievement goal orientations (mastery, performance, and work-avoidance goals), and learning strategies (deep processing, surface processing and self-handicapping strategies). Participants were 323 5th and 6th grade students in elementary schools. The results from structural equation modeling indicated that perceptions of classroom mastery goal structures were associated with students' mastery goal orientations, which were in turn related positively to the deep processing strategies and academic achievement. Perceptions of classroom performance goal stractures proved associated with work avoidance-goal orientations, which were positively related to the surface processing and self-handicapping strategies. Two types of goal structures had a positive relation with students' performance goal orientations, which had significant positive effects on academic achievement. The results of this study suggest that elementary school students' perceptions of mastery goal structures are related to adaptive patterns of learning more than perceptions of performance goal structures are. The role of perceptions of classroom goal structure in promoting students' goal orientations and learning strategies is discussed.

  2. Structural Graphical Lasso for Learning Mouse Brain Connectivity

    KAUST Repository

    Yang, Sen

    2015-08-07

    Investigations into brain connectivity aim to recover networks of brain regions connected by anatomical tracts or by functional associations. The inference of brain networks has recently attracted much interest due to the increasing availability of high-resolution brain imaging data. Sparse inverse covariance estimation with lasso and group lasso penalty has been demonstrated to be a powerful approach to discover brain networks. Motivated by the hierarchical structure of the brain networks, we consider the problem of estimating a graphical model with tree-structural regularization in this paper. The regularization encourages the graphical model to exhibit a brain-like structure. Specifically, in this hierarchical structure, hundreds of thousands of voxels serve as the leaf nodes of the tree. A node in the intermediate layer represents a region formed by voxels in the subtree rooted at that node. The whole brain is considered as the root of the tree. We propose to apply the tree-structural regularized graphical model to estimate the mouse brain network. However, the dimensionality of whole-brain data, usually on the order of hundreds of thousands, poses significant computational challenges. Efficient algorithms that are capable of estimating networks from high-dimensional data are highly desired. To address the computational challenge, we develop a screening rule which can quickly identify many zero blocks in the estimated graphical model, thereby dramatically reducing the computational cost of solving the proposed model. It is based on a novel insight on the relationship between screening and the so-called proximal operator that we first establish in this paper. We perform experiments on both synthetic data and real data from the Allen Developing Mouse Brain Atlas; results demonstrate the effectiveness and efficiency of the proposed approach.

  3. Do sophisticated epistemic beliefs predict meaningful learning? Findings from a structural equation model of undergraduate biology learning

    Science.gov (United States)

    Lee, Silvia Wen-Yu; Liang, Jyh-Chong; Tsai, Chin-Chung

    2016-10-01

    This study investigated the relationships among college students' epistemic beliefs in biology (EBB), conceptions of learning biology (COLB), and strategies of learning biology (SLB). EBB includes four dimensions, namely 'multiple-source,' 'uncertainty,' 'development,' and 'justification.' COLB is further divided into 'constructivist' and 'reproductive' conceptions, while SLB represents deep strategies and surface learning strategies. Questionnaire responses were gathered from 303 college students. The results of the confirmatory factor analysis and structural equation modelling showed acceptable model fits. Mediation testing further revealed two paths with complete mediation. In sum, students' epistemic beliefs of 'uncertainty' and 'justification' in biology were statistically significant in explaining the constructivist and reproductive COLB, respectively; and 'uncertainty' was statistically significant in explaining the deep SLB as well. The results of mediation testing further revealed that 'uncertainty' predicted surface strategies through the mediation of 'reproductive' conceptions; and the relationship between 'justification' and deep strategies was mediated by 'constructivist' COLB. This study provides evidence for the essential roles some epistemic beliefs play in predicting students' learning.

  4. Unsupervised Learning and Pattern Recognition of Biological Data Structures with Density Functional Theory and Machine Learning.

    Science.gov (United States)

    Chen, Chien-Chang; Juan, Hung-Hui; Tsai, Meng-Yuan; Lu, Henry Horng-Shing

    2018-01-11

    By introducing the methods of machine learning into the density functional theory, we made a detour for the construction of the most probable density function, which can be estimated by learning relevant features from the system of interest. Using the properties of universal functional, the vital core of density functional theory, the most probable cluster numbers and the corresponding cluster boundaries in a studying system can be simultaneously and automatically determined and the plausibility is erected on the Hohenberg-Kohn theorems. For the method validation and pragmatic applications, interdisciplinary problems from physical to biological systems were enumerated. The amalgamation of uncharged atomic clusters validated the unsupervised searching process of the cluster numbers and the corresponding cluster boundaries were exhibited likewise. High accurate clustering results of the Fisher's iris dataset showed the feasibility and the flexibility of the proposed scheme. Brain tumor detections from low-dimensional magnetic resonance imaging datasets and segmentations of high-dimensional neural network imageries in the Brainbow system were also used to inspect the method practicality. The experimental results exhibit the successful connection between the physical theory and the machine learning methods and will benefit the clinical diagnoses.

  5. Learning structural bioinformatics and evolution with a snake puzzle

    Directory of Open Access Journals (Sweden)

    Gonzalo S. Nido

    2016-12-01

    Full Text Available We propose here a working unit for teaching basic concepts of structural bioinformatics and evolution through the example of a wooden snake puzzle, strikingly similar to toy models widely used in the literature of protein folding. In our experience, developed at a Master’s course at the Universidad Autónoma de Madrid (Spain, the concreteness of this example helps to overcome difficulties caused by the interdisciplinary nature of this field and its high level of abstraction, in particular for students coming from traditional disciplines. The puzzle will allow us discussing a simple algorithm for finding folded solutions, through which we will introduce the concept of the configuration space and the contact matrix representation. This is a central tool for comparing protein structures, for studying simple models of protein energetics, and even for a qualitative discussion of folding kinetics, through the concept of the Contact Order. It also allows a simple representation of misfolded conformations and their free energy. These concepts will motivate evolutionary questions, which we will address by simulating a structurally constrained model of protein evolution, again modelled on the snake puzzle. In this way, we can discuss the analogy between evolutionary concepts and statistical mechanics that facilitates the understanding of both concepts. The proposed examples and literature are accessible, and we provide supplementary material (see ‘Data Availability’ to reproduce the numerical experiments. We also suggest possible directions to expand the unit. We hope that this work will further stimulate the adoption of games in teaching practice.

  6. Gas Hydrate Petroleum System Modeling in western Nankai Trough Area

    Science.gov (United States)

    Tanaka, M.; Aung, T. T.; Fujii, T.; Wada, N.; Komatsu, Y.

    2017-12-01

    Since 2003, we have been conducting Gas Hydrate (GH) petroleum system models covering the eastern Nankai Trough, Japan, and results of resource potential from regional model shows good match with the value depicted from seismic and log data. In this year, we have applied this method to explore GH potential in study area. In our study area, GH prospects have been identified with aid of bottom simulating reflector (BSR) and presence of high velocity anomalies above the BSR interpreted based on 3D migration seismic and high density velocity cubes. In order to understand the pathway of biogenic methane from source to GH prospects 1D-2D-3D GH petroleum system models are built and investigated. This study comprises lower Miocene to Pleistocene, deep to shallow marine sedimentary successions of Pliocene and Pleistocene layers overlain the basement. The BSR were interpreted in Pliocene and Pleistocene layers. Based on 6 interpreted sequence boundaries from 3D migration seismic and velocity data, construction of a depth 3D framework model is made and distributed by a conceptual submarine fan depositional facies model derived from seismic facies analysis and referring existing geological report. 1D models are created to analyze lithology sensitivity to temperature and vitrinite data from an exploratory well drilled in the vicinity of study area. The PSM parameters are applied in 2D and 3D modeling and simulation. Existing report of the explanatory well reveals that thermogenic origin are considered to exist. For this reason, simulation scenarios including source formations for both biogenic and thermogenic reaction models are also investigated. Simulation results reveal lower boundary of GH saturation zone at pseudo wells has been simulated with sensitivity of a few tens of meters in comparing with interpreted BSR. From sensitivity analysis, simulated temperature was controlled by different peak generation temperature models and geochemical parameters. Progressive folding

  7. Frictional Behavior of Altered Basement Approaching the Nankai Trough

    Science.gov (United States)

    Saffer, D. M.; Ikari, M.; Rooney, T. O.; Marone, C.

    2017-12-01

    The frictional behavior of basement rocks plays an important role in subduction zone faulting and seismicity. This includes earthquakes seaward of the trench, large megathrust earthquakes where seamounts are subducting, or where the plate interface steps down to basement. In exhumed subduction zone rocks such as the Shimanto complex in Japan, slivers of basalt are entrained in mélange which is evidence of basement involvement in the fault system. Scientific drilling during the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) recovered basement rock from two reference sites (C0011 and C0012) located seaward of the trench offshore the Kii Peninsula during Integrated Ocean Discovery Program (IODP) Expeditions 322 and 333. The basement rocks are pillow basalts that appear to be heterogeneously altered, resulting in contrasting dense blue material and more vesicular gray material. Major element geochemistry shows differences in silica, calcium oxides and loss-on-ignition between the two types of samples. Minor element geochemistry reveals significant differences in vanadium, chromium, and barium. X-ray diffraction on a bulk sample powder representing an average composition shows a phyllosilicate content of 20%, most of which is expandable clays. We performed laboratory friction experiments in a biaxial testing apparatus as either intact sample blocks, or as gouge powders. We combine these experiments with measurements of Pennsylvania slate for comparison, including a mixed-lithology intact block experiment. Intact Nankai basement blocks exhibit a coefficient of sliding friction of 0.73; for Nankai basement powder, slate powder, slate blocks and slate-on-basement blocks the coefficient of sliding friction ranges from 0.44 to 0.57. At slip rates ranging from 3x10-8 to 3x10-4 m/s we observe predominantly velocity-strengthening frictional behavior, indicating a tendency for stable slip. At rates of < 1x10-6 m/s some velocity-weakening was observed, specifically in

  8. Morphological evolution of Jinshan Trough in Hangzhou Bay (China) from 1960 to 2011

    Science.gov (United States)

    Liu, Yifei; Xia, Xiaoming; Chen, Shenliang; Jia, Jianjun; Cai, Tinglu

    2017-11-01

    An extensive system of tidal channels, starting with Jinshan Trough in the east, is located along the north shore of Hangzhou Bay, China. This contribution investigates the morphological evolution of Jinshan Trough by using 17 bathymetric charts from a series covering a period of 51 years from 1960 to 2011. Three stages of evolution during this period are distinguishable based on the morphology and annual mean volume data. The first stage (1960-1987) is characterized by extension of the trough; the second stage (1987-1996) is a relatively stable period with some adjustments in the trough morphology; the third stage (1996-2011) is marked by the processes of erosion and deposition in the beginning of the period and a subsequent slow erosion process. Spatio-temporal variability of the trough was evaluated by using empirical orthogonal function (EOF) analysis. The first eigenfunction indicates that erosion is the main evolution process and there exists three stages similar to those distinguished from volume variations. The second eigenfunction mainly reflects erosion and deposition in the northwest part of the trough located in the flood tidal current shadow area of the artificial headland in Jinshan. The third eigenfunction mainly reflects annual fluctuations of erosion and deposition in the side slope at the artificial headland in Jinshan. A particularly intense erosion process occurred between 1996 and 1998. The major effects on morphological evolution in Jinshan Trough from 1960 to 2011 were investigated and tentative conclusions were presented. Continuous coastal reclamations in Jinshan had the most pronounced effect on the morphological evolution during the first and the second stages. The storm surge had a pronounced effect on the evolution at the beginning of the third stage.

  9. Structure, Content, Delivery, Service, and Outcomes: Quality e-Learning in higher education

    Directory of Open Access Journals (Sweden)

    Colla J. MacDonald

    2005-07-01

    Full Text Available This paper addresses the need for quality e-Learning experiences. We used the Demand-Driven Learning Model (MacDonald, Stodel, Farres, Breithaupt, and Gabriel, 2001 to evaluate an online Masters in Education course. Multiple data collection methods were used to understand the experiences of stakeholders in this case study: the learners, design team, and facilitators. We found that all five dimensions of the model (structure, content, delivery, service, and outcomes must work in concert to implement a quality e-Learning course. Key themes include evolving learner needs, the search for connection, becoming an able e-participant, valued interactions, social construction of content, integration of delivery partners, and mindful weighing of benefits and trade-offs. By sharing insights into what is needed to design and deliver an e-Learning experience, our findings add to the growing knowledge of online learning. Using this model to evaluate perceptions of quality by key stakeholders has led to insights and recommendations on the Demand Driven Learning Model itself which may be useful for researchers in this area and strengthen the model. Quality has been defined in terms of the design of the e-Learning experience, the contextualized experience of learners, and evidence of learning outcomes (Carr and Carr, 2000; Jung 2000; Salmon, 2000. Quality and design of e-Learning courses, however, are sometimes compromised in an “ . . . effort to simply get something up and running��� in response to pressing consumer demands (Dick, 1996, p. 59. Educators and researchers have voiced concern over the lack of rigorous evaluation studies of e-Learning programs (e.g., Arbaugh, 2000; Howell, Saba, Lindsay, and Williams, 2004; Lockyer, Patterson, and Harper, 1999; Robinson, 2001. McGorry (2003 adds, “although the number of courses being delivered via the Internet is increasing rapidly, our knowledge of what makes these courses effective learning experiences

  10. Chronological age and its impact on associative learning proficiency and brain structure in middle adulthood.

    Science.gov (United States)

    Diwadkar, Vaibhav A; Bellani, Marcella; Ahmed, Rizwan; Dusi, Nicola; Rambaldelli, Gianluca; Perlini, Cinzia; Marinelli, Veronica; Ramaseshan, Karthik; Ruggeri, Mirella; Bambilla, Paolo

    2016-01-15

    The rate of biological change in middle-adulthood is relatively under-studied. Here, we used behavioral testing in conjunction with structural magnetic resonance imaging to examine the effects of chronological age on associative learning proficiency and on brain regions that previous functional MRI studies have closely related to the domain of associative learning. Participants (n=66) completed a previously established associative learning paradigm, and consented to be scanned using structural magnetic resonance imaging. Age-related effects were investigated both across sub-groups in the sample (younger vs. older) and across the entire sample (using regression approaches). Chronological age had substantial effects on learning proficiency (independent of IQ and Education Level), with older adults showing a decrement compared to younger adults. In addition, decreases in estimated gray matter volume were observed in multiple brain regions including the hippocampus and the dorsal prefrontal cortex, both of which are strongly implicated in associative learning. The results suggest that middle adulthood may be a more dynamic period of life-span change than previously believed. The conjunctive application of narrowly focused tasks, with conjointly acquired structural MRI data may allow us to enrich the search for, and the interpretation of, age-related changes in cross-sectional samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Empirical investigation of e-learning acceptance and assimilation: A structural equation model

    Directory of Open Access Journals (Sweden)

    Said S. Al-Gahtani

    2016-01-01

    Full Text Available E-learning has become progressively more vital for academia and corporate training and has potentially become one of the most significant developments and applications in Information Technologies (ITs. This study used a quantitative approach seeking a causative explanation of the decision behavior of individuals toward the acceptance and assimilation of e-learning in academic settings. A survey of 286 participants (students was conducted to collect the research data. Our study framework was based on the third version of the Technology Acceptance Model (i.e., TAM3 and the data were analyzed using structural equation modeling in order to determine the factors that influence the learners’ intention to use e-learning. Results show the predicting (promoting/inhibiting factors of e-learning technology acceptance, while also examining some related post-implementation interventions expected to contribute to the acceptance and assimilation of e-learning systems. Our results also indicate that TAM3 holds well in the Arabian culture and also outline valuable outcomes such as: managerial interventions and controls for better organizational e-learning management that can lead to greater acceptance and effective utilization. Hopefully, this study provides a roadmap to more understanding of the success factors and post-implementation interventions contributing to the acceptance and assimilation of e-learning systems in developing countries.

  12. A Cultural Psychological Approach to Analyze Intercultural Learning: Potential and Limits of the Structure Formation Technique

    Directory of Open Access Journals (Sweden)

    Doris Weidemann

    2009-01-01

    Full Text Available Despite the huge interest in sojourner adjustment, there is still a lack of qualitative as well as of longitudinal research that would offer more detailed insights into intercultural learning processes during overseas stays. The present study aims to partly fill that gap by documenting changes in knowledge structures and general living experiences of fifteen German sojourners in Taiwan in a longitudinal, cultural-psychological study. As part of a multimethod design a structure formation technique was used to document subjective theories on giving/losing face and their changes over time. In a second step results from this study are compared to knowledge-structures of seven long-term German residents in Taiwan, and implications for the conceptualization of intercultural learning will be proposed. Finally, results from both studies serve to discuss the potential and limits of structure formation techniques in the field of intercultural communication research. URN: urn:nbn:de:0114-fqs0901435

  13. Physical cognition: birds learn the structural efficacy of nest material.

    Science.gov (United States)

    Bailey, Ida E; Morgan, Kate V; Bertin, Marion; Meddle, Simone L; Healy, Susan D

    2014-06-07

    It is generally assumed that birds' choice of structurally suitable materials for nest building is genetically predetermined. Here, we tested that assumption by investigating whether experience affected male zebra finches' (Taeniopygia guttata) choice of nest material. After a short period of building with relatively flexible string, birds preferred to build with stiffer string while those that had experienced a stiffer string were indifferent to string type. After building a complete nest with either string type, however, all birds increased their preference for stiff string. The stiffer string appeared to be the more effective building material as birds required fewer pieces of stiffer than flexible string to build a roofed nest. For birds that raised chicks successfully, there was no association between the material they used to build their nest and the type they subsequently preferred. Birds' material preference reflected neither the preference of their father nor of their siblings but juvenile experience of either string type increased their preference for stiffer string. Our results represent two important advances: (i) birds choose nest material based on the structural properties of the material; (ii) nest material preference is not entirely genetically predetermined as both the type and amount of experience influences birds' choices.

  14. Social Learning Theory, Gender, and Intimate Partner Violent Victimization: A Structural Equations Approach.

    Science.gov (United States)

    Powers, Ráchael A; Cochran, John K; Maskaly, Jon; Sellers, Christine S

    2017-05-01

    The purpose of this study is to examine the applicability of Akers's Social Learning Theory (SLT) to explain intimate partner violence (IPV) victimization. In doing so, we draw on the Intergenerational Transmission of Violence Theory (IGT) to extend the scope of SLT to the explanation of victimization and for a consideration of uniquely gendered pathways in its causal structure. Using a structural equation modeling approach with self-report data from a sample of college students, the present study tests the extent to which SLT can effectively explain and predict IPV victimization and the degree, if any, to which the social learning model is gender invariant. Although our findings are largely supportive of SLT and, thus, affirm its extension to victimization as well as perpetration, the findings are also somewhat mixed. More significantly, in line with IGT literature, we find that the social learning process is not gender invariant. The implications of the latter are discussed.

  15. Training and learning robotic surgery, time for a more structured approach: a systematic review

    NARCIS (Netherlands)

    Schreuder, H. W. R.; Wolswijk, R.; Zweemer, R. P.; Schijven, M. P.; Verheijen, R. H. M.

    2012-01-01

    Background Robotic assisted laparoscopic surgery is growing rapidly and there is an increasing need for a structured approach to train future robotic surgeons. Objectives To review the literature on training and learning strategies for robotic assisted laparoscopic surgery. Search strategy A

  16. Enabling School Structures, Collegial Trust and Academic Emphasis: Antecedents of professional learning communities

    Science.gov (United States)

    Gray, Julie; Kruse, Sharon; Tarter, C. John

    2016-01-01

    This study tested the role of enabling school structures, collegial trust and academic emphasis in the development of professional learning communities (PLCs) in a low-income school district. The empirical study was based upon the perceptions of teachers and principals as provided by survey responses (N = 67 schools). While enabling school…

  17. Using Jigsaw-Style Spectroscopy Problem-Solving to Elucidate Molecular Structure through Online Cooperative Learning

    Science.gov (United States)

    Winschel, Grace A.; Everett, Renata K.; Coppola, Brian P.; Shultz, Ginger V.

    2015-01-01

    Cooperative learning was employed as an instructional approach to facilitate student development of spectroscopy problem solving skills. An interactive online environment was used as a framework to structure weekly discussions around spectroscopy problems outside of class. Weekly discussions consisted of modified jigsaw-style problem solving…

  18. Structural adoption of web lectures in higher educational programmes: impact on quality of teaching and learning

    NARCIS (Netherlands)

    M.W. (Martijn) Hartog; A.W. (Bert) Mulder

    2014-01-01

    In this paper we reflect on research projects examining the broad and structural adaption of web lectures and e-learning within Universities and Universities of Applied Sciences. In particular the ‘University 2.0’ research programme (2012-2013) of The Hague University of Applied Sciences in which we

  19. Relationship between Professional Learning Community, Bureaucratic Structure and Organisational Trust in Primary Education Schools

    Science.gov (United States)

    Kalkan, Fatma

    2016-01-01

    This research uses relational survey method to determine the relationship between professional learning community, bureaucratic structure and organisational trust according to the perceptions of teachers who work in primary education schools. Data were collected from 805 teachers who work in primary education schools in the districts (Altindag,…

  20. Bayesian structure learning for Markov Random Fields with a spike and slab prior

    NARCIS (Netherlands)

    Chen, Y.; Welling, M.; de Freitas, N.; Murphy, K.

    2012-01-01

    In recent years a number of methods have been developed for automatically learning the (sparse) connectivity structure of Markov Random Fields. These methods are mostly based on L1-regularized optimization which has a number of disadvantages such as the inability to assess model uncertainty and

  1. Social Structure and Individual Agency in Second Language Learning: Evidence from Three Life Histories

    Science.gov (United States)

    Flowerdew, John; Miller, Lindsay

    2008-01-01

    This paper examines the issue of social structure and individual agency in language learning through the life histories of three young engineering graduates in Hong Kong. English is identified as an important form of cultural capital, which to a considerable extent determines the development of the three individuals, each of whom comes from a…

  2. System Characteristics, Satisfaction and E-Learning Usage: A Structural Equation Model (SEM)

    Science.gov (United States)

    Ramayah, T.; Lee, Jason Wai Chow

    2012-01-01

    With the advent of the Internet, more and more public universities in Malaysia are putting in effort to introduce e-learning in their respective universities. Using a structured questionnaire derived from the literature, data was collected from 250 undergraduate students from a public university in Penang, Malaysia. Data was analyzed using AMOS…

  3. The Factor Structure of Preschool Learning Behaviors Scale Scores in Peruvian Children

    Science.gov (United States)

    Hahn, Kathryn R.; Schaefer, Barbara A.; Merino, Cesar; Worrell, Frank C.

    2009-01-01

    The factor structure of the Escala de Conductas de Aprendizaje Preescolar (ECAP), a Spanish translation of the Preschool Learning Behaviors Scale (PLBS), was examined in this study. Children aged 2 to 6 years (N = 328) enrolled in public and private preschools in the Republic of Peru were rated by classroom teachers on the frequency of observable,…

  4. "Information in Context": Co-Designing Workplace Structures and Systems for Organizational Learning

    Science.gov (United States)

    Somerville, Mary M.; Howard, Zaana

    2010-01-01

    Introduction: This paper discusses an "information in context" design project at Auraria Library in Denver, Colorado which aims to collaboratively create organizational structures and communication systems with and for library employees. Method: This action research project is founded within shared leadership, informed learning and…

  5. Structural Validity of the WISC-IV for Students with Learning Disabilities

    Science.gov (United States)

    Styck, Kara M.; Watkins, Marley W.

    2016-01-01

    The structural validity of the "Wechsler Intelligence Scale for Children-Fourth Edition" (WISC-IV) was evaluated using confirmatory factor analysis for a clinical sample of 1,537 students diagnosed with specific learning disabilities (SLD) by school psychologists in two large southwestern school districts. Results indicated that a…

  6. WISC-R Factor Structures for Diagnosed Learning Disabled Navajo and Papago Children.

    Science.gov (United States)

    Zarske, John A.; And Others

    1981-01-01

    Wechsler Intelligence Scale for Children (Revised) (WISC-R) factor structures were compared for learning disabled Navajo and Papago children. Results support the validity of the WISC-R as a measure of general intellectual functioning, and verbal and performance aspects for both groups, indicating its appropriateness for diverse groups of children.…

  7. Neural-Fitted TD-Leaf Learning for Playing Othello With Structured Neural Networks

    NARCIS (Netherlands)

    van den Dries, Sjoerd; Wiering, Marco A.

    This paper describes a methodology for quickly learning to play games at a strong level. The methodology consists of a novel combination of three techniques, and a variety of experiments on the game of Othello demonstrates their usefulness. First, structures or topologies in neural network

  8. Addressing special structure in the relevance feedback learning problem through aspect-based image search

    NARCIS (Netherlands)

    M.J. Huiskes (Mark)

    2004-01-01

    textabstractIn this paper we focus on a number of issues regarding special structure in the relevance feedback learning problem, most notably the effects of image selection based on partial relevance on the clustering behavior of examples. We propose a simple scheme, aspect-based image search, which

  9. High-resolution records of thermocline in the Okinawa Trough since about 10000 aBP

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The present paper uses planktonic foraminifera and their stableisotopes to study the changes in the depth of thermocline (DOT) in the Okinawa Trough since the last 10000 a based on the analysis of Core B-3GC in the northern Okinawa Trough, together with that of the core in the southern Okinawa Trough. As results show, the thermocline was shallow before 6400 aBP, and deepened afterward, then became shallow again from 4000 to 2000 aBP. The DOT fluctuations display a positive correlation with those of sea surface temperature (SST). In addition, the changes in the northern Okinawa Trough are similar to those in the southern trough, implying a possible connection with the variation of the Kuroshio Current. The changes of SST and DOT suggest that the Kuroshio Current changed its intensity or main axis from 4000 to 2000 aBP and around about 6400 aBP respectively. Moreover, the changes of DOT from 8200 to 6400 aBP may indicate a gradual intensification of the Kuroshio Current.

  10. Comparative analyses of the bacterial community of hydrothermal deposits and seafloor sediments across Okinawa Trough

    Science.gov (United States)

    Wang, Long; Yu, Min; Liu, Yan; Liu, Jiwen; Wu, Yonghua; Li, Li; Liu, Jihua; Wang, Min; Zhang, Xiao-Hua

    2018-04-01

    As an ideal place to study back-arc basins and hydrothermal eco-system, Okinawa Trough has attracted the interests of scientists for decades. However, there are still no in-depth studies targeting the bacterial community of the seafloor sediments and hydrothermal deposits in Okinawa Trough. In the present study, we reported the bacterial community of the surface deposits of a newly found hydrothermal field in the southern Okinawa Trough, and the horizontal and vertical variation of bacterial communities in the sediments of the northern Okinawa Trough. The hydrothermal deposits had a relatively high 16S rRNA gene abundance but low bacterial richness and diversity. Epsilonproteobacteria and Bacteroidetes were predominant in hydrothermal deposits whereas Deltaproteobacteria, Gammaproteobacteria and Chloroflexi were abundant across all samples. The bacterial distribution in the seafloor of Okinawa Trough was significantly correlated to the content of total nitrogen, and had consistent relationship with total carbon. Gradual changes of sulfur-oxidizing bacteria were found with the distance away from hydrothermal fields, while the hydrothermal activity did not influence the distribution of the major clades of sulfate-reducing bacteria. Higher abundance of the sulfur cycle related genes (aprA and dsrB), and lower abundance of the bacterial ammonia-oxidizing related gene (amoA) were quantified in hydrothermal deposits. In addition, the present study also compared the inter-field variation of Epsilonproteobacteria among multi-types of hydrothermal vents, revealing that the proportion and diversity of this clade were quite various.

  11. Operationalising Public Space Activity and Structuring Redevelopment Trough Public Facilities Planning in a Configurational Urban Structure

    NARCIS (Netherlands)

    Read, S.A.; Wang, J.

    2012-01-01

    Forms in planning often do not match the forms of cities. This is important because the experience and functionings of cities are given by certain forms and not by others. In particular we are concerned here with the fact planning and design thinking often assumes a nested hierarchy of communities

  12. An Analysis of Density and Degree-Centrality According to the Social Networking Structure Formed in an Online Learning Environment

    Science.gov (United States)

    Ergün, Esin; Usluel, Yasemin Koçak

    2016-01-01

    In this study, we assessed the communication structure in an educational online learning environment using social network analysis (SNA). The communication structure was examined with respect to time, and instructor's participation. The course was implemented using ELGG, a network learning environment, blended with face-to-face sessions over a…

  13. The Domains of Organizational Learning Practices: An Agency-Structure Perspective

    Directory of Open Access Journals (Sweden)

    Nancy Beauregard

    2015-10-01

    Full Text Available Background: Organizational learning theory has retained considerable attention in the past decades from a wide array of academic disciplines in social sciences. Yet few integrative efforts have satisfactorily offered a comprehensive and systematic articulation of the concept of organizational learning with regards to: (a its core constitutive dimensions and associated mechanisms; (b the analytical levels from such mechanisms operate (e.g., workers, teams, organizations; as well as (c their interplay. Methods: This article builds on a critical synthesis of predominant approaches in organizational learning theory (i.e., structural functionalist, social constructivist and middle range approaches, highlighting the contributions of each approach on the key analytical elements guiding our inquiry (i.e., core dimensions and associated mechanisms, analytical levels, interplay. Drawing from the work of sociologists Anthony Giddens and Margaret Archer on agency-structure theory, we develop a series of theoretical propositions supporting the Organizational Learning Practices (OLP concept as a unifying heuristic tool. Results: OLP are defined as a set of collectively shared practices held by members of a given organization embedded in normative, political, and semantic dynamics. At the heart of such dynamics lies organizational knowledge as a power resource pivotal to the sustainable development of organizations, as well as that of their members. Conclusion: OLP offer promising answers to on-going debates in organizational learning theory, and we conclude by discussing concrete guidelines to advance research and practice on OLP.

  14. THE MEDIATING ROLE OF SCIENCE MUSEUM IN STRUCTURING AND SYNTHESIS OF LEARNING

    Directory of Open Access Journals (Sweden)

    Fanny Angulo Delgado

    2016-10-01

    Full Text Available Understanding the mediating role of science museum in learning scientific content in school, it involves reflecting on the contributions of research to the question of what and how people learn in non-conventional educational settings. It has been shown that most people spend less than 3% of their lives learning in school, which emphasizes the importance of conceptualizing what they are and how much of their learning take place. While that question is resolved, it speaks at this bioassay on the complementary relationship between the museum and the school, as both institutions share the same educational purpose, but differ in the ways of achieving it. The science museum joins the class as a mediator that facilitates student learning as part of an education that promotes understanding of the phenomena of the world through models, which means that school learning goes in stages, one of which is that students have opportunity to structure new knowledge and synthesize on its own model. For this it is necessary that students speak, read, listen and write in science class, while the thought is expressed in language to attest to the facts. These communication skills arise in science class as indicators of mediation exercised by the museum and allow us to understand that it takes place in at least two dimensions: museographic and didactics.

  15. Team Leader Structuring for Team Effectiveness and Team Learning in Command-and-Control Teams

    Science.gov (United States)

    van der Haar, Selma; Koeslag-Kreunen, Mieke; Euwe, Eline; Segers, Mien

    2017-01-01

    Due to their crucial and highly consequential task, it is of utmost importance to understand the levers leading to effectiveness of multidisciplinary emergency management command-and-control (EMCC) teams. We argue that the formal EMCC team leader needs to initiate structure in the team meetings to support organizing the work as well as facilitate team learning, especially the team learning process of constructive conflict. In a sample of 17 EMCC teams performing a realistic EMCC exercise, including one or two team meetings (28 in sum), we coded the team leader’s verbal structuring behaviors (1,704 events), rated constructive conflict by external experts, and rated team effectiveness by field experts. Results show that leaders of effective teams use structuring behaviors more often (except asking procedural questions) but decreasingly over time. They support constructive conflict by clarifying and by making summaries that conclude in a command or decision in a decreasing frequency over time. PMID:28490856

  16. Team Leader Structuring for Team Effectiveness and Team Learning in Command-and-Control Teams.

    Science.gov (United States)

    van der Haar, Selma; Koeslag-Kreunen, Mieke; Euwe, Eline; Segers, Mien

    2017-04-01

    Due to their crucial and highly consequential task, it is of utmost importance to understand the levers leading to effectiveness of multidisciplinary emergency management command-and-control (EMCC) teams. We argue that the formal EMCC team leader needs to initiate structure in the team meetings to support organizing the work as well as facilitate team learning, especially the team learning process of constructive conflict. In a sample of 17 EMCC teams performing a realistic EMCC exercise, including one or two team meetings (28 in sum), we coded the team leader's verbal structuring behaviors (1,704 events), rated constructive conflict by external experts, and rated team effectiveness by field experts. Results show that leaders of effective teams use structuring behaviors more often (except asking procedural questions) but decreasingly over time. They support constructive conflict by clarifying and by making summaries that conclude in a command or decision in a decreasing frequency over time.

  17. Balanced Cross Section for Restoration of Tectonic Evolution in the Southwest Okinawa Trough

    Institute of Scientific and Technical Information of China (English)

    Wu Shiguo; Ni Xianglong; Guo Junhua

    2007-01-01

    On the basis of the multi-channel seismic data and the other data, using 2DMove software,the tectonic evolution in three seismic profiles was restored since Pliocene. The tectonic restoration results show that: (1) the initial active center lay in the west slope and then was transferred to east and south via trough center during the evolution process; (2) several main normal faults controlled the evolution of the southern Okinawa Trough; (3) since Late Pliocene, the southern Okinawa Trough has experienced two spreading stages. The early is depression in Early-Middle Pleistocene and the late is back-arc spreading in Late Pleistocene and Holocene, which is in primary oceanic crust spreading stage.

  18. Evidence and mechanism of Hurricane Fran-Induced ocean cooling in the Charleston Trough

    Science.gov (United States)

    Xie, Lian; Pietrafesa, L. J.; Bohm, E.; Zhang, C.; Li, X.

    Evidence of enhanced sea surface cooling during and following the passage of Hurricane Fran in September 1996 over an oceanic depression located on the ocean margin offshore of Charleston, South Carolina (referred to as the Charleston Trough), [Pietrafesa, 1983] is documented. Approximately 4C° of sea surface temperature (SST) reduction within the Charleston Trough following the passage of Hurricane Fran was estimated based on SST imagery from Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-14 polar orbiting satellite. Simulations using a three-dimensional coastal ocean model indicate that the largest SST reduction occurred within the Charleston Trough. This SST reduction can be explained by oceanic mixing due to storm-induced internal inertia-gravity waves.

  19. Balancing vancomycin efficacy and nephrotoxicity: should we be aiming for trough or AUC/MIC?

    Science.gov (United States)

    Patel, Karisma; Crumby, Ashley S; Maples, Holly D

    2015-04-01

    Sixty years later, the question that still remains is how to appropriately utilize vancomycin in the pediatric population. The Infectious Diseases Society of America published guidelines in 2011 that provide guidance for dosing and monitoring of vancomycin in adults and pediatrics. However, goal vancomycin trough concentrations of 15-20 μg/mL for invasive infections caused by methicillin-resistant Staphylococcus aureus were based primarily on adult pharmacokinetic and pharmacodynamic data that achieved an area under the curve to minimum inhibitory concentration ratio (AUC/MIC) of ≥400. Recent pediatric literature shows that vancomycin trough concentrations needed to achieve the target AUC/MIC are different than the adult goal troughs cited in the guidelines. This paper addresses several thoughts, including the role of vancomycin AUC/MIC in dosing strategies and safety monitoring, consistency in laboratory reporting, and future directions for calculating AUC/MIC in pediatrics.

  20. Machine-learning approach for local classification of crystalline structures in multiphase systems

    Science.gov (United States)

    Dietz, C.; Kretz, T.; Thoma, M. H.

    2017-07-01

    Machine learning is one of the most popular fields in computer science and has a vast number of applications. In this work we will propose a method that will use a neural network to locally identify crystal structures in a mixed phase Yukawa system consisting of fcc, hcp, and bcc clusters and disordered particles similar to plasma crystals. We compare our approach to already used methods and show that the quality of identification increases significantly. The technique works very well for highly disturbed lattices and shows a flexible and robust way to classify crystalline structures that can be used by only providing particle positions. This leads to insights into highly disturbed crystalline structures.

  1. Analysis of factors affecting satisfaction level on problem based learning approach using structural equation modeling

    Science.gov (United States)

    Hussain, Nur Farahin Mee; Zahid, Zalina

    2014-12-01

    Nowadays, in the job market demand, graduates are expected not only to have higher performance in academic but they must also be excellent in soft skill. Problem-Based Learning (PBL) has a number of distinct advantages as a learning method as it can deliver graduates that will be highly prized by industry. This study attempts to determine the satisfaction level of engineering students on the PBL Approach and to evaluate their determinant factors. The Structural Equation Modeling (SEM) was used to investigate how the factors of Good Teaching Scale, Clear Goals, Student Assessment and Levels of Workload affected the student satisfaction towards PBL approach.

  2. Mineralogy and geological significance of hydrothermal deposits from the Okinawa Trough

    Science.gov (United States)

    Zhang, Xia; Zhai, Shikui; Yu, Zenghui; Wang, Shujie; Cai, Zongwei

    2018-04-01

    The study of hydrothermal deposits in the Okinawa Trough can help us to uncover the hydrothermal mineralization characteristics in the back-arc basin during the early expanding stage. Mineralogy and geological significance of hydrothermal deposits from both the middle and southern trough are studied in this paper. First of all, using optical microscope to confirm the mineral compositions, characteristics of crystal shape, paragenetic relationship and minerals crystallization order. Then the minerals chemical composition were analyzed in virtue of electron microprobe. On these basis, the paragenetic sequence and the mineralization characteristics of the hydrothermal deposits were discussed. The results show that the hydrothermal deposit from the mid-Okinawa Trough belongs to Zn-Cu-rich type, consisting dominantly of sulfide minerals such as sphalerite, chalcopyrite, pyrite, etc. The minerals crystallization order is first generation pyrite(PyI)-sphalerite-chalcopyrite-galena-second generation pyrite(PyII)-amorphous silica. While the deposit from the southern Okinawa Trough is Ba-Zn-Pb-rich type mainly composing of barite, sphalerite, galena, etc. The minerals crystallization order is barite-pyrite-sphalerite-tetrahedrite-galena-chalcopyrite-amorphous silica. Hydrothermal fluid temperature in the mid-Okinawa Trough undergoes a process from high to low, which is high up to 350 °C in the early stage, but decreasing gradually with the evolution of hydrothermal fluid. On the contrary, the hydrothermal activity in the southern Okinawa Trough is low temperature dominated, but the mineralization environment is unstable and the fluid temperature changes drastically during the period of hydrothermal activity.

  3. Tracking local control of a parabolic trough collector; Control local de seguimiento cilindro parabolico ACE20

    Energy Technology Data Exchange (ETDEWEB)

    Ajona, J I; Alberdi, J; Gamero, E; Blanco, J

    1992-07-01

    In the local control, the sun position related to the trough collector is measured by two photo-resistors. The provided electronic signal is then compared with reference levels in order to get a set of B logical signals which form a byte. This byte and the commands issued by a programmable controller are connected to the inputs of o P.R.O.M. memory which is programmed with the logical equations of the control system. The memory output lines give the control command of the parabolic trough collector motor. (Author)

  4. Tracking local control of a parabolic trough collector. Control local de Seguimiento cilindro parabolico ACE 20

    Energy Technology Data Exchange (ETDEWEB)

    Ajona Maeztu, J.I.; Alberdi Primicia, J.; Gamero Aranda, E.; Blanco, J.

    1991-01-01

    In the local control, the sun position related to the trough collector is measured by two photo-resistors. the provided electronic signal is then compared with reference levels in order to get a set of 8 logical signals which form a byte. This byte and the commands issued by a programmable controller are connected to the inputs of a P.R.O.M. memory which is programmed with the logical ecuations of the control system. the memory output lines give the control commands of the parabolic trough collector motor. (author)

  5. Tracking local control of a parabolic trough collector; Control local de Seguimiento cilindro parabolico ACE 20

    Energy Technology Data Exchange (ETDEWEB)

    Ajona Maeztu, J.I.; Alberdi Primicia, J.; Gamero Aranda, E.; Blanco, J.

    1991-12-31

    In the local control, the sun position related to the trough collector is measured by two photo-resistors. the provided electronic signal is then compared with reference levels in order to get a set of 8 logical signals which form a byte. This byte and the commands issued by a programmable controller are connected to the inputs of a P.R.O.M. memory which is programmed with the logical ecuations of the control system. the memory output lines give the control commands of the parabolic trough collector motor. (author)

  6. Optical and mechanical tolerances in hybrid concentrated thermal-PV solar trough.

    Science.gov (United States)

    Diaz, Liliana Ruiz; Cocilovo, Byron; Miles, Alexander; Pan, Wei; Blanche, Pierre-Alexandre; Norwood, Robert A

    2018-05-14

    Hybrid thermal-PV solar trough collectors combine concentrated photovoltaics and concentrated solar power technology to harvest and store solar energy. In this work, the optical and mechanical requirements for optimal efficiency are analyzed using non-sequential ray tracing techniques. The results are used to generate opto-mechanical tolerances that can be compared to those of traditional solar collectors. We also explore ideas on how to relieve tracking tolerances for single-axis solar collectors. The objective is to establish a basis for tolerances required for the fabrication and manufacturing of hybrid solar trough collectors.

  7. Many play concepts seen over wide area in Erris, Slyne troughs off Ireland

    International Nuclear Information System (INIS)

    Murphy, N.J.; Croker, P.F.

    1992-01-01

    This paper reports that the Erris and Slyne troughs are underexplored Mesozoic sedimentary basins off Ireland's northwest coast. The Irish Minister for Energy announced on Apr. 19, 1991, a frontier acreage licensing round of 128 blocks covering 29,000 sq km in these basins and the adjacent Rockall trough. Closing date for the round is June 30, 1993, set to allow two seasons for the acquisition of new geophysical and geological data over the area. Ireland has recently announced a new petroleum taxation regime. Revised licensing terms, which will acknowledge the specific circumstances of frontier acreage, will be announced

  8. Structured feedback on students' concept maps: the proverbial path to learning?

    Science.gov (United States)

    Joseph, Conran; Conradsson, David; Nilsson Wikmar, Lena; Rowe, Michael

    2017-05-25

    Good conceptual knowledge is an essential requirement for health professions students, in that they are required to apply concepts learned in the classroom to a variety of different contexts. However, the use of traditional methods of assessment limits the educator's ability to correct students' conceptual knowledge prior to altering the educational context. Concept mapping (CM) is an educational tool for evaluating conceptual knowledge, but little is known about its use in facilitating the development of richer knowledge frameworks. In addition, structured feedback has the potential to develop good conceptual knowledge. The purpose of this study was to use Kinchin's criteria to assess the impact of structured feedback on the graphical complexity of CM's by observing the development of richer knowledge frameworks. Fifty-eight physiotherapy students created CM's targeting the integration of two knowledge domains within a case-based teaching paradigm. Each student received one round of structured feedback that addressed correction, reinforcement, forensic diagnosis, benchmarking, and longitudinal development on their CM's prior to the final submission. The concept maps were categorized according to Kinchin's criteria as either Spoke, Chain or Net representations, and then evaluated against defined traits of meaningful learning. The inter-rater reliability of categorizing CM's was good. Pre-feedback CM's were predominantly Chain structures (57%), with Net structures appearing least often. There was a significant reduction of the basic Spoke- structured CMs (P = 0.002) and a significant increase of Net-structured maps (P student development.

  9. Investigating the potential of e-Learning in healthcare postgraduate curricula: a structural equation model.

    Science.gov (United States)

    Katharaki, Maria; Daskalakis, Stelios; Mantas, John

    2010-01-01

    The objective of this paper is to assess the future adaptability of e-Learning platforms within postgraduate modules. An ongoing empirical assessment was conducted amongst postgraduate students, based on the Technology Acceptance Model (TAM). The current paper presents the outcomes from the second phase of a survey, involving fifty six participants. Data analysis was performed using a structural equation model, based on partial least squares. Results highlighted the very strong effect of perceived usefulness and perceived ease of use to attitude towards using e-Learning platforms. Consequently, attitude towards use proved to be a very strong predictor of behavioral intention. Perceived usefulness, on the contrary, did not prove to have an effect to behavioral intention. Implications on the potential of using e-Learning platforms are discussed along with limitations and future directions of the study.

  10. Plate boundary deformation at the latitude of the Salton Trough - northern Gulf of California (Invited)

    Science.gov (United States)

    Stock, J. M.

    2013-12-01

    Along the Pacific-North America plate boundary zone, the segment including the southern San Andreas fault to Salton Trough and northern Gulf of California basins has been transtensional throughout its evolution, based on Pacific-North America displacement vectors calculated from the global plate circuit (900 × 20 km at N54°W since 20 Ma; 460 × 20 km at N48°W since 11 Ma). Nevertheless, active seismicity and focal mechanisms show a broad zone of plate boundary deformation within which the inferred stress regime varies locally (Yang & Hauksson 2013 GJI), and fault patterns in some regions suggest ongoing tectonic rotation. Similar behavior is inferred to have occurred in this zone over most of its history. Crustal structure in this region is constrained by surface geology, geophysical experiments (e.g., the 2011 Salton Seismic Imaging Project (SSIP), USGS Imperial Valley 1979, PACE), and interdisciplinary marine and onland studies in Mexico (e.g., NARS-Baja, Cortes, and surveys by PEMEX). Magnetic data (e.g., EMAG-2) aids in the recognition of large-scale crustal provinces and fault boundaries in regions lacking detailed geophysical surveys. Consideration of existing constraints on crustal thickness and architecture, and fault and basin evolution suggests that to reconcile geological deformation with plate motion history, the following additional factors need to be taken into account. 1) Plate boundary displacement via interacting systems of rotating blocks, coeval with slip on steep strike slip faults, and possibly related to slip on low angle extensional faults (e.g, Axen & Fletcher 1998 IGR) may be typical prior to the onset of seafloor spreading. This fault style may have accommodated up to 150 km of plate motion in the Mexican Continental Borderland and north of the Vizcaino Peninsula, likely between 12 and 15 Ma, as well as explaining younger rotations adjacent to the Gulf of California and current deformation southwest of the Salton Sea. 2) Geophysical

  11. Building Knowledge Structures by Testing Helps Children With Mathematical Learning Difficulty.

    Science.gov (United States)

    Zhang, Yiyun; Zhou, Xinlin

    2016-01-01

    Mathematical learning difficulty (MLD) is prevalent in the development of mathematical abilities. Previous interventions for children with MLD have focused on number sense or basic mathematical skills. This study investigated whether mathematical performance of fifth grade children with MLD could be improved by developing knowledge structures by testing using a web-based curriculum learning system. A total of 142 children with MLD were recruited; half of the children were in the experimental group (using the system), and the other half were in the control group (not using the system). The children were encouraged to use the web-based learning system at home for at least a 15-min session, at least once a week, for one and a half months. The mean accumulated time of testing on the system for children in the experimental group was 56.2 min. Children in the experimental group had significantly higher scores on their final mathematical examination compared to the control group. The results suggest that web-based curriculum learning through testing that promotes the building of knowledge structures for a mathematical course was helpful for children with MLD. © Hammill Institute on Disabilities 2014.

  12. A Deep Learning Network Approach to ab initio Protein Secondary Structure Prediction.

    Science.gov (United States)

    Spencer, Matt; Eickholt, Jesse; Jianlin Cheng

    2015-01-01

    Ab initio protein secondary structure (SS) predictions are utilized to generate tertiary structure predictions, which are increasingly demanded due to the rapid discovery of proteins. Although recent developments have slightly exceeded previous methods of SS prediction, accuracy has stagnated around 80 percent and many wonder if prediction cannot be advanced beyond this ceiling. Disciplines that have traditionally employed neural networks are experimenting with novel deep learning techniques in attempts to stimulate progress. Since neural networks have historically played an important role in SS prediction, we wanted to determine whether deep learning could contribute to the advancement of this field as well. We developed an SS predictor that makes use of the position-specific scoring matrix generated by PSI-BLAST and deep learning network architectures, which we call DNSS. Graphical processing units and CUDA software optimize the deep network architecture and efficiently train the deep networks. Optimal parameters for the training process were determined, and a workflow comprising three separately trained deep networks was constructed in order to make refined predictions. This deep learning network approach was used to predict SS for a fully independent test dataset of 198 proteins, achieving a Q3 accuracy of 80.7 percent and a Sov accuracy of 74.2 percent.

  13. Oceanic Sub-Moho Reflectors in and Around the Segmentation Boundary Between the Tonankai-Nankai Earthquake Area, the Central Nankai Trough

    Science.gov (United States)

    Nakanishi, A.; Kodaira, S.; Miura, S.; Ito, A.; Sato, T.; Park, J.; Obana, K.; Kaneda, Y.

    2006-12-01

    The Nankai Trough is a unique subduction zone because the recurrence intervals of M8 class earthquakes and the segmentation of rupture zones are well documented on the basis of geophysical, geological and historic data. In 2004, large intraslab earthquake (Mw7.5) occurred southeast off the Kii Peninsula, the central Nankai Trough. Recent ocean bottom seismograph observation off the Kii Peninsula shows seismicity concentrated in the oceanic crust and the uppermost mantle. To understand the genesis of such intraslab earthquakes and its relation to large interplate earthquakes as well as to obtain an entire structural image of Nankai Trough subduction seismogenic zone, a wide-angle reflection/refraction survey across the coseismic rupture zone of the Tonankai earthquake was conducted in 2004. This research is part of "Structure research on plate dynamics of the presumed rupture zone of the Tonankai-Nankai Earthquakes" funded by Ministry of Education, Culture, Sports, Science and Technology. The result of structural image shows a bit thicker oceanic crust (>8km) subducting landward, and the existence of oceanic sub-Moho reflectors in the uppermost mantle. The aftershocks of the 2004 off Kii Peninsula earthquake are distributed within the oceanic crust and the uppermantle, which is not consistent with the estimated fault plane of main shock. Comparing the structural image with this aftershock distribution and usual seismicity in the uppermost mantle, the depth of the oceanic sub-Moho reflectors and the intraslab events within the uppermantle are both distributed around 20km. We consider that such sub-Moho reflectors may become a seismic fault of intraslab earthquakes.

  14. Troughs in Ice Sheets and Other Icy Deposits on Mars: Analysis of Their Radiative Balance

    Science.gov (United States)

    Fountain, A.; Kargel, J.; Lewis, K.; MacAyeal, D.; Pfeffer, T.; Zwally, H. J.

    2000-01-01

    It has long been known that groove-like structures in glaciers and ice sheets can trap more incoming solar radiation than is the case for a 'normal' flat, smooth surface. In this presentation, we shall describe the radiative regimes of typical scarps and troughs on icy surfaces of Mars, and suggest how these features originate and evolve through time. The basis of our analysis is the radiation balance model presented by Pfeffer and Bretherton. Their model considers the visible band radiation regime of a V-shaped groove on a terrestrial ice surface, and shows that absorbed energy can be enhanced by up to 50 percent for grooves with small opening angles and with typical polar values of the solar zenith angle. Our work extends this model by considering: (a) departures from V-shaped geometry, (b) both englacial and surficial dust and debris, and (c) the infrared spectrum. We apply the extended model to various features on the Martian surface, including the spiral-like scarps on the Northern and Southern ice sheets, the large-scale chasms (e.g., Chasm Borealis), and groove-like lineations on valley floors thought to be filled with mixtures of dust and icy substances. In conjunction with study of valley-closure experiments, we suggest that spiral-like scarps and chasms are stable features of the Martian climate regime. We also suggest that further study of scarps and chasms may shed light on the composition (i.e., relative proportions of water ice, carbon-dioxide ice and dust) of the Martian ice sheets and valley fills.

  15. 9 CFR 82.21 - Vehicles, cages, coops, containers, troughs, and other equipment used for infected poultry.

    Science.gov (United States)

    2010-01-01

    ..., troughs, and other equipment used for infected poultry. 82.21 Section 82.21 Animals and Animal Products... ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS EXOTIC NEWCASTLE DIS- EASE (END) AND CHLAMYDIOSIS Chlamydiosis in Poultry § 82.21 Vehicles, cages, coops, containers, troughs, and other equipment used for...

  16. A comparison of the relative locations of the mid-latitude electron density trough and the scintillation boundary

    International Nuclear Information System (INIS)

    Tulunay, Y.K.; Demir, O.; Tauriainen, A.

    1976-01-01

    The mid-latitude electron density trough position and the scintillation boundary have been compared for magnetically quiet periods by using the data returned by Ariel 3 and Explorer 22 satellites. The scintillation boundary is found southward of the trough during daytime, but at night the positions are reversed. (author)

  17. In Silico Prediction of Chemical Toxicity for Drug Design Using Machine Learning Methods and Structural Alerts

    Science.gov (United States)

    Yang, Hongbin; Sun, Lixia; Li, Weihua; Liu, Guixia; Tang, Yun

    2018-02-01

    For a drug, safety is always the most important issue, including a variety of toxicities and adverse drug effects, which should be evaluated in preclinical and clinical trial phases. This review article at first simply introduced the computational methods used in prediction of chemical toxicity for drug design, including machine learning methods and structural alerts. Machine learning methods have been widely applied in qualitative classification and quantitative regression studies, while structural alerts can be regarded as a complementary tool for lead optimization. The emphasis of this article was put on the recent progress of predictive models built for various toxicities. Available databases and web servers were also provided. Though the methods and models are very helpful for drug design, there are still some challenges and limitations to be improved for drug safety assessment in the future.

  18. In Silico Prediction of Chemical Toxicity for Drug Design Using Machine Learning Methods and Structural Alerts

    Directory of Open Access Journals (Sweden)

    Hongbin Yang

    2018-02-01

    Full Text Available During drug development, safety is always the most important issue, including a variety of toxicities and adverse drug effects, which should be evaluated in preclinical and clinical trial phases. This review article at first simply introduced the computational methods used in prediction of chemical toxicity for drug design, including machine learning methods and structural alerts. Machine learning methods have been widely applied in qualitative classification and quantitative regression studies, while structural alerts can be regarded as a complementary tool for lead optimization. The emphasis of this article was put on the recent progress of predictive models built for various toxicities. Available databases and web servers were also provided. Though the methods and models are very helpful for drug design, there are still some challenges and limitations to be improved for drug safety assessment in the future.

  19. In Silico Prediction of Chemical Toxicity for Drug Design Using Machine Learning Methods and Structural Alerts.

    Science.gov (United States)

    Yang, Hongbin; Sun, Lixia; Li, Weihua; Liu, Guixia; Tang, Yun

    2018-01-01

    During drug development, safety is always the most important issue, including a variety of toxicities and adverse drug effects, which should be evaluated in preclinical and clinical trial phases. This review article at first simply introduced the computational methods used in prediction of chemical toxicity for drug design, including machine learning methods and structural alerts. Machine learning methods have been widely applied in qualitative classification and quantitative regression studies, while structural alerts can be regarded as a complementary tool for lead optimization. The emphasis of this article was put on the recent progress of predictive models built for various toxicities. Available databases and web servers were also provided. Though the methods and models are very helpful for drug design, there are still some challenges and limitations to be improved for drug safety assessment in the future.

  20. Sizing optimization of skeletal structures using teaching-learning based optimization

    Directory of Open Access Journals (Sweden)

    Vedat Toğan

    2017-03-01

    Full Text Available Teaching Learning Based Optimization (TLBO is one of the non-traditional techniques to simulate natural phenomena into a numerical algorithm. TLBO mimics teaching learning process occurring between a teacher and students in a classroom. A parameter named as teaching factor, TF, seems to be the only tuning parameter in TLBO. Although the value of the teaching factor, TF, is determined by an equation, the value of 1 or 2 has been used by the researchers for TF. This study intends to explore the effect of the variation of teaching factor TF on the performances of TLBO. This effect is demonstrated in solving structural optimization problems including truss and frame structures under the stress and displacement constraints. The results indicate that the variation of TF in the TLBO process does not change the results obtained at the end of the optimization procedure when the computational cost of TLBO is ignored.

  1. Structural analysis of factors that influence professional learning communities in Korean elementary schools

    Directory of Open Access Journals (Sweden)

    Kyoung-Oh Song

    2017-09-01

    Full Text Available Professional Learning Communities(PLCs arean important strategy for innovation in schools, and they arereceiving considerable attention from scholars and educators alike. The present study aimed to examine the effect of PLCson schools’ effectiveness and to investigate the social, organizational, and structural factors that can promote these learning communities. The survey for this study was completed by 375 teachers from 40 elementary schools in the Seoul Metropolitan Area of South Korea, and their responses were analyzed to test the hypothesized model. The results of the structural equationmodeling indicated that PLCswere strongly and directly related to elementary schools’ effectivenessand that principals’ leadership and supportive relationshipsamong teachers were the important factors that influenced PLCs. Based on the results of this study, several implications are discussed.

  2. Learning Bayesian network structure: towards the essential graph by integer linear programming tools

    Czech Academy of Sciences Publication Activity Database

    Studený, Milan; Haws, D.

    2014-01-01

    Roč. 55, č. 4 (2014), s. 1043-1071 ISSN 0888-613X R&D Projects: GA ČR GA13-20012S Institutional support: RVO:67985556 Keywords : learning Bayesian network structure * integer linear programming * characteristic imset * essential graph Subject RIV: BA - General Mathematics Impact factor: 2.451, year: 2014 http://library.utia.cas.cz/separaty/2014/MTR/studeny-0427002.pdf

  3. Geochemistry of trace elements and Sr- Nd isotopes of foraminifera shell from the Okinawa Trough

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Trace elemental associations and Sr - Nd isotopic compositions are of important to recognition of biogenic material from mixed marine sediments. The foraminifera shell from the Okinawa Trough strongly enrichesSr, P, Mn andBa, enriches Li, U, Th, Sc, Co, Cu, Pb, Zn, Cr, Rb, Y, Sb and light rare earth elements, slightly enriches V, Ga, Zr, Nb, Cd and middle rare earth elements,is short of Mo, In, Sn, Cs, Hf, Ta, W, Ti, Bi and heavy rare earth elements. The mechanism of elemental enrichment in forminifera is the concentrations of trace elements in sea water and selective absorption of trace elements during foraminifera living, as well as the geochemical affinity between major elements and trace elements. The REE (rare earth elements) partition pattern of foraminifera shell of the Okinawa Trough shows enrichment of middle rare earth elements with slightly negative Ce anomaly,which are different from those of foraminifera of the Pacific Ocean. The Sr, Nd isotopic ratios of the Okinawa Trough foraminifera are 0.709 769 and 0.512 162, respectively, which are different not only from those of oceanic water, but also from those of river water of China's Mainland, the former is slightly higher than those of oceanic water, but much lower than those of river water; the latter is slightly lower than those of oceanic water, but higher than those of river water, demonstrating that the Okinawa Trough sea water has been influenced by river water of China's Mainland.

  4. Upstream sediment input effects on experimental dune trough scour in sediment mixtures

    NARCIS (Netherlands)

    Kleinhans, M.G.

    2005-01-01

    Understanding causes of dune irregularity, especially dune trough scour, is important for the modeling of vertical sorting of sediment mixtures in morphological models of rivers with sediment mixtures. Sediment in dunes is generally sorted in a fining-upward manner, which affects the sediment

  5. Overland conveyors. Cable or trough belt for 100 km transport haulage

    Energy Technology Data Exchange (ETDEWEB)

    Maton, A.E. [Maton Engineering Pty. Ltd., Orange Grove, WA (Australia)

    2009-07-01

    With the advances in belt conveyor technology today systems of 100 kilometres length are increasingly being considered. This article provides a comparison of two concepts for a 100 kilometre system of five 20 kilometre flights based on trough belt and cable belt technology. (orig.)

  6. Influence of pen area and trough space on feedlot performance of ...

    African Journals Online (AJOL)

    performance. There was no advantage in allowing more than 170 mm trough space or more than 5,5 m2 floor area per animal with the conditions and climate under which these trials were conducted ... pen area on feed intake and feedlot performance. A total of 196 dehorned ... Standard deviation (kg). 0,19. 0,18. 0,19. 0,15.

  7. Altitude variation of the plasmapause signature in the main ionospheric trough

    Czech Academy of Sciences Publication Activity Database

    Grebowsky, J. M.; Benson, R. F.; Webb, P. A.; Truhlík, Vladimír; Bilitza, D.

    2009-01-01

    Roč. 71, č. 16 (2009), s. 1669-1676 ISSN 1364-6826 R&D Projects: GA AV ČR IAA300420603 Institutional research plan: CEZ:AV0Z30420517 Keywords : Plasmapause * Ionosphere * Midlatitude Trough Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.643, year: 2009

  8. Numerical simulation of tropical-temperate troughs over Southern Africa using the CSU RAMS model

    CSIR Research Space (South Africa)

    Van den Heever, SC

    1997-08-01

    Full Text Available ) and the wet (1981) late summer case studies has been examined. Model simulations reveal that the tropical-temperate troughs form when an upper westerly wave coincides with an easterly, wave or depression in lower levels. These systems occur preferentially over...

  9. Investigation on the dynamic behaviour of a parabolic trough power plant during strongly cloudy days

    International Nuclear Information System (INIS)

    Al-Maliki, Wisam Abed Kattea; Alobaid, Falah; Starkloff, Ralf; Kez, Vitali; Epple, Bernd

    2016-01-01

    Highlights: • A detailed dynamic model of a parabolic trough solar thermal power plant is done. • Simulated results are compared to the experimental data from the real power plant. • Discrepancy between model result and real data is caused by operation strategy. • The model strategy increased the operating hours of power plant by around 2.5–3 h. - Abstract: The objective of this study is the development of a full scale dynamic model of a parabolic trough power plant with a thermal storage system, operated by the Actividades de Construcción y Servicios Group in Spain. The model includes solar field, thermal storage system and the power block and describes the heat transfer fluid and steam/water paths in detail. The parabolic trough power plant is modelled using Advanced Process Simulation Software (APROS). To validate the model, the numerical results are compared to the measured data, obtained from “Andasol II” during strongly cloudy periods in the summer days. The comparisons show a qualitative agreement between the dynamic simulation model and the measurements. The results confirm that the thermal storage enables the parabolic trough power plant to provide a constant power rate when the storage energy discharge is available, despite significant oscillations in the solar radiation.

  10. A numerical analysis of the energy behavior of a parabolic trough ...

    African Journals Online (AJOL)

    The solar power is a clean and a durable energy; there are several techniques for using them. When necessary to elevated temperatures of heat transfer fluid, this energy must concentration. This paper presents the efficiencies study of a linear solar concentrator of a parabolic trough type. This study was conducted on the ...

  11. A twin study of the trough plasma steady-state concentration of metformin

    DEFF Research Database (Denmark)

    Stage, Tore B; Damkier, Per; Pedersen, Rasmus S

    2015-01-01

    OBJECTIVE: The aim of this study was to determine the intrapair similarity in trough steady-state plasma concentrations of metformin in monozygotic and dizygotic twin pairs. METHODS: We included 16 twin pairs (eight monozygotic and eight dizygotic twin pairs) for this study after contacting 524 t...

  12. O+ trough zones in the polar cap ionosphere-magnetosphere coupling region

    Science.gov (United States)

    Horwitz, James; Zeng, Wen; Jaafari, Fajer

    Regions of low-density troughs in O+ have been observed at 1 RE altitude in the polar cap ionosphere-magnetosphere region by the Thermal Ion Dynamics Experiment(TIDE) on the POLAR spacecraft. In this presentation, the UT Arlington Dynamic Fluid-Kinetic (DyFK) code is employed to investigate the formation of such O+ density troughs. We utilize convection paths of flux tubes in the high-latitude region as prescribed by an empirical convection model with solar wind inputs to track the evolution of ionospheric plasma transport and in particular O+ densities along these tubes with time/space. The flux tubes are subjected to auroral processes of precipitation and wave-driven ion heating when they pass through the auroral oval, which tends to elevate the plasma densities in these tubes. When the F-regions of such tubes traverse locations where the F-region is in darkness, recombination there causes the higher-altitude regions to drain and the densities to decline throughout. Owing to the varying effects of these processes, significant and low trough-like densities at higher altitudes developed along these flux tubes. The modeled densities near 6000 km altitudes will be compared with multiple POLAR passes featuring POLAR/TIDE-measured O+ densities for inside and outside of such trough regions.

  13. Optimized Structure of the Traffic Flow Forecasting Model With a Deep Learning Approach.

    Science.gov (United States)

    Yang, Hao-Fan; Dillon, Tharam S; Chen, Yi-Ping Phoebe

    2017-10-01

    Forecasting accuracy is an important issue for successful intelligent traffic management, especially in the domain of traffic efficiency and congestion reduction. The dawning of the big data era brings opportunities to greatly improve prediction accuracy. In this paper, we propose a novel model, stacked autoencoder Levenberg-Marquardt model, which is a type of deep architecture of neural network approach aiming to improve forecasting accuracy. The proposed model is designed using the Taguchi method to develop an optimized structure and to learn traffic flow features through layer-by-layer feature granulation with a greedy layerwise unsupervised learning algorithm. It is applied to real-world data collected from the M6 freeway in the U.K. and is compared with three existing traffic predictors. To the best of our knowledge, this is the first time that an optimized structure of the traffic flow forecasting model with a deep learning approach is presented. The evaluation results demonstrate that the proposed model with an optimized structure has superior performance in traffic flow forecasting.

  14. Identifying Structural Flow Defects in Disordered Solids Using Machine-Learning Methods

    Science.gov (United States)

    Cubuk, E. D.; Schoenholz, S. S.; Rieser, J. M.; Malone, B. D.; Rottler, J.; Durian, D. J.; Kaxiras, E.; Liu, A. J.

    2015-03-01

    We use machine-learning methods on local structure to identify flow defects—or particles susceptible to rearrangement—in jammed and glassy systems. We apply this method successfully to two very different systems: a two-dimensional experimental realization of a granular pillar under compression and a Lennard-Jones glass in both two and three dimensions above and below its glass transition temperature. We also identify characteristics of flow defects that differentiate them from the rest of the sample. Our results show it is possible to discern subtle structural features responsible for heterogeneous dynamics observed across a broad range of disordered materials.

  15. What we learned from Darvin

    Science.gov (United States)

    Poklopova, L.; Frouz, J.

    2009-04-01

    Charles Darwin published 1881 his famous book Creation of vegetable mould trough action of worms. Books was published in 3,500 copies, which were sold almost instantly but how much we learn from the book, how much of the ideas were used by other researches and how much forgotten and re discovered again.

  16. Understanding the Compositional Variability of the Major Components of Hydrothermal Plumes in the Okinawa Trough

    Directory of Open Access Journals (Sweden)

    Zhigang Zeng

    2018-01-01

    Full Text Available Studies of the major components of hydrothermal plumes in seafloor hydrothermal fields are critical for an improved understanding of biogeochemical cycles and the large-scale distribution of elements in the submarine environment. The composition of major components in hydrothermal plume water column samples from 25 stations has been investigated in the middle and southern Okinawa Trough. The physical and chemical properties of hydrothermal plume water in the Okinawa Trough have been affected by input of the Kuroshio current, and its influence on hydrothermal plume water from the southern Okinawa Trough to the middle Okinawa Trough is reduced. The anomalous layers of seawater in the hydrothermal plume water columns have higher K+, Ca2+, Mn2+, B3+, Ca2+/SO42-, and Mn2+/Mg2+ ratios and higher optical anomalies than other layers. The Mg2+, SO42-, Mg2+/Ca2+, and SO42-/Mn2+ ratios of the anomalous layers are lower than other layers in the hydrothermal plume water columns and are consistent with concentrations in hydrothermal vent fluids in the Okinawa Trough. This suggests that the chemical variations of hydrothermal plumes in the Tangyin hydrothermal field, like other hydrothermal fields, result in the discharge of high K+, Ca2+, and B3+ and low Mg2+ and SO42- fluid. Furthermore, element ratios (e.g., Sr2+/Ca2+, Ca2+/Cl− in hydrothermal plume water columns were found to be similar to those in average seawater, indicating that Sr2+/Ca2+ and Ca2+/Cl− ratios of hydrothermal plumes might be useful proxies for chemical properties of seawater. The hydrothermal K+, Ca2+, Mn2+, and B3+ flux to seawater in the Okinawa Trough is about 2.62–873, 1.04–326, 1.30–76.4, and 0.293–34.7 × 106 kg per year, respectively. The heat flux is about 0.159–1,973 × 105 W, which means that roughly 0.0006% of ocean heat is supplied by seafloor hydrothermal plumes in the Okinawa Trough.

  17. A ∼180,000 years sedimentation history of a perialpine overdeepened glacial trough (Wehntal, N-Switzerland)

    International Nuclear Information System (INIS)

    Anselmetti, F. S.; Drescher-Schneider, R.; Furrer, H.; Graf, H. R.; Lowick, S. E.; Preusser, F.; Riedi, M. A.

    2010-01-01

    A 30 m-deep drill core from a glacially overdeepened trough in Northern Switzerland recovered a ∼ 180 ka old sedimentary succession that provides new insights into the timing and nature of erosion-sedimentation processes in the Swiss lowlands. The luminescence-dated stratigraphic succession starts at the bottom of the core with laminated carbonate-rich lake sediments reflecting deposition in a proglacial lake between ∼ 180 and 130 ka ago (Marine Isotope Stage MIS 6). Anomalies in geotechnical properties and the occurrence of deformation structures suggest temporary ice contact around 140 ka. Up-core, organic content increases in the lake deposits indicating a warming of climate. These sediments are overlain by a peat deposit characterised by pollen assemblages typical of the late Eemian (MIS 5e). An abrupt transition following this interglacial encompasses a likely hiatus and probably marks a sudden lowering of the water level. The peat unit is overlain by deposits of a cold unproductive lake dated to late MIS 5 and MIS 4, which do not show any direct influence from glaciers. An upper peat unit, the so-called M ammoth peat , previously encountered in construction pits, interrupts this cold lacustrine phase and marks more temperate climatic conditions between 60 and 45 ka (MIS 3). In the upper part of the core, a succession of fluvial and alluvial deposits documents the Late Glacial and Holocene sedimentation in the basin. The sedimentary succession at Wehntal confirms that the glaciation during MIS 6 did not apparently cause the overdeepening of the valley, as the lacustrine basin fill covering most of MIS 6 is still preserved. Consequently, erosion of the basin is most likely linked to an older glaciation. This study shows that new dating techniques combined with paleoenvironmental interpretations of sediments from such overdeepened troughs provide valuable insights into the past glacial history. (authors)

  18. A {approx}180,000 years sedimentation history of a perialpine overdeepened glacial trough (Wehntal, N-Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Anselmetti, F. S. [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Duebendorf (Switzerland); Drescher-Schneider, R. [Institut fuer Pflanzenwissenschaften, Karl-Fanzen-Universitaet Graz, Graz (Austria); Furrer, H. [Palaeontologisches Institut und Museum, Universitaet Zuerich, Zuerich (Switzerland); Graf, H. R. [Matousek, Baumann und Niggli AG, Baden (Switzerland); Lowick, S. E.; Preusser, F. [Institut fuer Geologie, Universitaet Bern, Bern (Switzerland); Riedi, M. A. [Marc A. Riedi, Susenbuehlstrasse 41, Chur (Switzerland)

    2010-11-15

    A 30 m-deep drill core from a glacially overdeepened trough in Northern Switzerland recovered a {approx} 180 ka old sedimentary succession that provides new insights into the timing and nature of erosion-sedimentation processes in the Swiss lowlands. The luminescence-dated stratigraphic succession starts at the bottom of the core with laminated carbonate-rich lake sediments reflecting deposition in a proglacial lake between {approx} 180 and 130 ka ago (Marine Isotope Stage MIS 6). Anomalies in geotechnical properties and the occurrence of deformation structures suggest temporary ice contact around 140 ka. Up-core, organic content increases in the lake deposits indicating a warming of climate. These sediments are overlain by a peat deposit characterised by pollen assemblages typical of the late Eemian (MIS 5e). An abrupt transition following this interglacial encompasses a likely hiatus and probably marks a sudden lowering of the water level. The peat unit is overlain by deposits of a cold unproductive lake dated to late MIS 5 and MIS 4, which do not show any direct influence from glaciers. An upper peat unit, the so-called {sup M}ammoth peat{sup ,} previously encountered in construction pits, interrupts this cold lacustrine phase and marks more temperate climatic conditions between 60 and 45 ka (MIS 3). In the upper part of the core, a succession of fluvial and alluvial deposits documents the Late Glacial and Holocene sedimentation in the basin. The sedimentary succession at Wehntal confirms that the glaciation during MIS 6 did not apparently cause the overdeepening of the valley, as the lacustrine basin fill covering most of MIS 6 is still preserved. Consequently, erosion of the basin is most likely linked to an older glaciation. This study shows that new dating techniques combined with paleoenvironmental interpretations of sediments from such overdeepened troughs provide valuable insights into the past glacial history. (authors)

  19. Estimating the complexity of 3D structural models using machine learning methods

    Science.gov (United States)

    Mejía-Herrera, Pablo; Kakurina, Maria; Royer, Jean-Jacques

    2016-04-01

    Quantifying the complexity of 3D geological structural models can play a major role in natural resources exploration surveys, for predicting environmental hazards or for forecasting fossil resources. This paper proposes a structural complexity index which can be used to help in defining the degree of effort necessary to build a 3D model for a given degree of confidence, and also to identify locations where addition efforts are required to meet a given acceptable risk of uncertainty. In this work, it is considered that the structural complexity index can be estimated using machine learning methods on raw geo-data. More precisely, the metrics for measuring the complexity can be approximated as the difficulty degree associated to the prediction of the geological objects distribution calculated based on partial information on the actual structural distribution of materials. The proposed methodology is tested on a set of 3D synthetic structural models for which the degree of effort during their building is assessed using various parameters (such as number of faults, number of part in a surface object, number of borders, ...), the rank of geological elements contained in each model, and, finally, their level of deformation (folding and faulting). The results show how the estimated complexity in a 3D model can be approximated by the quantity of partial data necessaries to simulated at a given precision the actual 3D model without error using machine learning algorithms.

  20. The impact of the structural features of the rock mass on seismicity in Polish coal mines

    Science.gov (United States)

    Patyńska, Renata

    2017-11-01

    The article presents seismic activity induced in the coal mines of the Upper Silesian Coal Basin (GZW) in relation to the locations of the occurrence of rockbursts. The comparison of these measurements with the structural features of the rock mass of coal mines indicates the possibility of estimating the so-called Unitary Energy Expenditure (UEE) in a specific time. The obtained values of UEE were compared with the distribution of seismic activity in GZW mines. The level of seismic activity in the analysed period changed and depended on the intensity of mining works and diverse mining and geological conditions. Five regions, where tremors occurred (Bytom Trough, Main Saddle, Main Trough, Kazimierz Trough, and Jejkowice and Chwałowice Trough) which belong to various structural units of the Upper Silesia were analyzed. It was found out that rock bursts were recorded only in three regions: Main Saddle, Bytom Trough, and Jejkowice and Chwałowice Trough.

  1. Paleoceanographic records in the sedimentary cores from the middle Okinawa Trough

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Two gravity piston cores (Cores 155 and 180) involved in this study were collected from the middle Okinawa Trough. Stratigraphy of the two cores was divided and classified based on the features of planktonic foraminifera oxygen isotope changes together with depositional sequence, millennium-scale climatic event comparison, carbonate cycles and AMS14C dating. Some paleoclimatic information contained in sediments of these cores was extracted to discuss the paleoclimatic change rules and the short-time scale events presented in interglacial period. Analysis on the variation of oxygen isotope values in stage two shows that the middle part of the Okinawa Trough may have been affected by fresh water from the Yellow River and the Yangtze River during the Last Glacial Maximum (LGM). The oxygen isotope value oscillating ranges of the cores have verified that the marginal sea has an amplifying effect on climate changes. The Δ13c of benthic foraminifera Uvigerina was lighter in the glacial period than that in the interglacial period, which indicates that the Paleo-Kuroshio's main stream moved eastward and its influence area decreased. According to the temperature difference during the "YD" period existing in Core 180 and other data, we can reach the conclusion that the climatic changes in the middle Okinawa Trough area were controlled by global climatic changes, but some regional factors had also considerable influence on the climate changes. Some results in this paper support Fairbanks's point that the "YD" event was a brief stagnation of sea level rising during the global warming up procession. Moreover, the falling of sea level in the glacial period weakened the exchange between the bottom water of the Okinawa Trough and the deep water of the northwestern Pacific Ocean and resulted in low oxygen state of bottom water in this area. These procedures are the reasons for carbonate cycle in the Okinawa Trough area being consistent with the "Atlantic type " carbonate cycle.

  2. Paleoceanographic records in the sedimentary cores from the middle Okinawa Trough

    Institute of Scientific and Technical Information of China (English)

    LIUYanguang; FUYunxia; DUDewen; MENGXianwei; LIANGRuicai; LITiegang; WUShiying

    2003-01-01

    Two gravity piston cores (Cores 155 and 180) involved in this study were collected from the middle Okinawa Trough. Stratigraphy of the two cores was divided and classified based on the features of planktonic foraminifera oxygen isotope changes together with depositional sequence,millennium-scale climatic event comparison, carbonate cycles and AMS14C dating. Some paleoclimatic information contained in sediments of these cores was extracted to discuss the paleoclimatic change rules and the short-time scale events presented in interglacial period. Analysis on the variation of oxygen isotope values in stage two shows that the middle part of the Okinawa Trough may have been affected by fresh water from the Yellow River and the Yangtze River during the Last Glacial Maximum (LGM). The oxygen isotope value oscillating ranges of the cores have verified that the marginal sea has an amplifying effect on climate changes.The δ13C of benthic foraminifera Uvigerina was lighter in the glacial period than that in the interglacial period, which indicates that the Paleo-Kuroshio's main stream moved eastward and its influence area decreased. According to the temperature difference during the “YD” period existing in Core 180 and other data, we can reach the conclusion that the climatic changes in the middle Okinawa Trough area were controlled by global climatic changes, but some regional factors had also considerable influence on the climatechanges. Some results in this paper support Fairbanks's point that the “YD” event was a brief stagnation of sea level rising during the global warming up procession. Moreover,the falling of sea level in the glacial period weakened the exchange between the bottom water of the Okinawa Trough and the deep water of the northwestern Pacific Ocean and resulted in low oxygen state of bottom water in this area.These procedures are the reasons for carbonate cycle in the Okinawa Trough area being consistent with the “Atlantic type”carbonate cycle.

  3. Model and control scheme for recirculation mode direct steam generation parabolic trough solar power plants

    International Nuclear Information System (INIS)

    Guo, Su; Liu, Deyou; Chen, Xingying; Chu, Yinghao; Xu, Chang; Liu, Qunming; Zhou, Ling

    2017-01-01

    Highlights: •A nonlinear dynamic model of recirculation DSG parabolic trough is developed. •Collector row, water separator and spray attemperator are modeled, respectively. •The dynamic behaviors of the collector field are simulated and analyzed. •Transfer functions of water level and outlet fluid temperature are derived. •Multi-model switching generalized predictive control strategy is developed. -- Abstract: This work describes and evaluates a new nonlinear dynamic model, and a new generalized predictive control scheme for a collector field of direct steam generation parabolic troughs in recirculation mode. Modeling the dynamic behaviors of collector fields is essential to design, testing and validation of automatic control systems for direct steam generation parabolic troughs. However, the behaviors of two-phase heat transfer fluids impose challenges to simulating and developing process control schemes. In this work, a new nonlinear dynamic model is proposed, based on the nonlinear distributed parameter and the nonlinear lumped parameter methods. The proposed model is used to simulate and analyze the dynamic behaviors of the entire collector field for recirculation mode direct steam generation parabolic troughs under different weather conditions, without excessive computational costs. Based on the proposed model, transfer functions for both the water level of the separator and outlet steam temperatures are derived, and a new multi-model switching generalized predictive control scheme is developed for simulated control of the plant behaviors for a wide region of operational conditions. The proposed control scheme achieves excellent control performance and robustness for systems with long delay, large inertia and time-varying parameters, and efficiently solves the model mismatching problem in direct steam generation parabolic troughs. The performances of the model and control scheme are validated with design data from the project of Integration of Direct

  4. Optical analysis of a photovoltaic V-trough system installed in western India.

    Science.gov (United States)

    Maiti, Subarna; Sarmah, Nabin; Bapat, Pratap; Mallick, Tapas K

    2012-12-20

    The low concentrating photovoltaic (PV) system such as a 2× V-trough system can be a promising choice for enhancing the power output from conventional PV panels with the inclusion of thermal management. This system is more attractive when the reflectors are retrofitted to the stationary PV panels installed in a high aspect ratio in the north-south direction and are tracked 12 times a year manually according to preset angles, thus eliminating the need of diurnal expensive tracking. In the present analysis, a V-trough system facing exactly the south direction is considered, where the tilt angle of the PV panels' row is kept constant at 18.34°. The system is installed on the terrace of CSIR-Central Salt and Marine Chemicals Research Institute in Bhavnagar, Gujarat, India (21.47 N, 71.15 E). The dimension of the entire PV system is 9.64 m×0.55 m. The V-troughs made of anodized aluminum reflectors (70% specular reflectivity) had the same dimensions. An in-house developed; experimentally validated Monte Carlo ray-trace model was used to study the effect of the angular variation of the reflectors throughout a year for the present assembly. Results of the ray trace for the optimized angles showed the maximum simulated optical efficiency to be 85.9%. The spatial distribution of solar intensity over the 0.55 m dimension of the PV panel due to the V-trough reflectors was also studied for the optimized days in periods that included solstices and equinoxes. The measured solar intensity profiles with and without the V-trough system were used to calculate the actual optical efficiencies for several sunny days in the year, and results were validated with the simulated efficiencies within an average error limit of 10%.

  5. Motivation, strategy, and English as a foreign language vocabulary learning: A structural equation modelling study.

    Science.gov (United States)

    Zhang, Yining; Lin, Chin-Hsi; Zhang, Dongbo; Choi, Yunjeong

    2017-03-01

    In spite of considerable advancements in our understanding of the different factors involved in achieving vocabulary-learning success, the overall pattern and interrelationships of critical factors involved in L2 vocabulary learning - particularly, the mechanisms through which learners regulate their motivation and learning strategies - remain unclear. This study examined L2 vocabulary learning, focusing on the joint influence of different motivational factors and learning strategies on the vocabulary breadth of adolescent learners of English as a foreign language (EFL) in China. The participants were 107 tenth graders (68 females, 39 males) in China. The data were collected via two questionnaires, one assessing students' motivation towards English-vocabulary learning and the other their English vocabulary-learning strategies, along with a test measuring vocabulary breadth. Structural equation modelling (SEM) indicated that learning strategy partially mediated the relationship between motivation (i.e., a composite score of intrinsic and extrinsic motivation) and vocabulary learning. Separate SEM analyses for intrinsic (IM) and extrinsic motivation (EM) revealed that there were significant and positive direct and indirect effects of IM on vocabulary knowledge; and while EM's direct effect over and above that of learning strategies did not achieve significance, its indirect effect was significant and positive. The findings suggest that vocabulary-learning strategies mediate the relationship between motivation and vocabulary knowledge. In addition, IM may have a greater influence on vocabulary learning in foreign-language contexts. © 2016 The British Psychological Society.

  6. WWC Quick Review of the Article "Culture and the Interaction of Student Ethnicity with Reward Structure in Group Learning" Revised

    Science.gov (United States)

    What Works Clearinghouse, 2010

    2010-01-01

    This paper presents an updated WWC (What Works Clearinghouse) Review of the Article "Culture and the Interaction of Student Ethnicity with Reward Structure in Group Learning". The study examined the effects of different reward systems used in group learning situations on the math skills of African-American and White students. The…

  7. WWC Review of the Article "Culture and the Interaction of Student Ethnicity with Reward Structure in Group Learning"

    Science.gov (United States)

    What Works Clearinghouse, 2010

    2010-01-01

    "Culture and the Interaction of Student Ethnicity with Reward Structure in Group Learning" examined the effects of different reward systems used in group learning situations on the math skills of African-American and white students. The study analyzed data on 75 African-American and 57 white fourth- and fifth-grade students from urban…

  8. A structured multi-stakeholder learning process for Sustainable Land Management.

    Science.gov (United States)

    Schwilch, Gudrun; Bachmann, Felicitas; Valente, Sandra; Coelho, Celeste; Moreira, Jorge; Laouina, Abdellah; Chaker, Miloud; Aderghal, Mohamed; Santos, Patricia; Reed, Mark S

    2012-09-30

    There are many, often competing, options for Sustainable Land Management (SLM). Each must be assessed - and sometimes negotiated - prior to implementation. Participatory, multi-stakeholder approaches to identification and selection of SLM options are increasingly popular, often motivated by social learning and empowerment goals. Yet there are few practical tools for facilitating processes in which land managers may share, select, and decide on the most appropriate SLM options. The research presented here aims to close the gap between the theory and the practice of stakeholder participation/learning in SLM decision-making processes. The paper describes a three-part participatory methodology for selecting SLM options that was tested in 14 desertification-prone study sites within the EU-DESIRE project. Cross-site analysis and in-depth evaluation of the Moroccan and Portuguese sites were used to evaluate how well the proposed process facilitated stakeholder learning and selection of appropriate SLM options for local implementation. The structured nature of the process - starting with SLM goal setting - was found to facilitate mutual understanding and collaboration between stakeholders. The deliberation process led to a high degree of consensus over the outcome and, though not an initial aim, it fostered social learning in many cases. This solution-oriented methodology is applicable in a wide range of contexts and may be implemented with limited time and resources. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Testing students' e-learning via Facebook through Bayesian structural equation modeling.

    Science.gov (United States)

    Salarzadeh Jenatabadi, Hashem; Moghavvemi, Sedigheh; Wan Mohamed Radzi, Che Wan Jasimah Bt; Babashamsi, Parastoo; Arashi, Mohammad

    2017-01-01

    Learning is an intentional activity, with several factors affecting students' intention to use new learning technology. Researchers have investigated technology acceptance in different contexts by developing various theories/models and testing them by a number of means. Although most theories/models developed have been examined through regression or structural equation modeling, Bayesian analysis offers more accurate data analysis results. To address this gap, the unified theory of acceptance and technology use in the context of e-learning via Facebook are re-examined in this study using Bayesian analysis. The data (S1 Data) were collected from 170 students enrolled in a business statistics course at University of Malaya, Malaysia, and tested with the maximum likelihood and Bayesian approaches. The difference between the two methods' results indicates that performance expectancy and hedonic motivation are the strongest factors influencing the intention to use e-learning via Facebook. The Bayesian estimation model exhibited better data fit than the maximum likelihood estimator model. The results of the Bayesian and maximum likelihood estimator approaches are compared and the reasons for the result discrepancy are deliberated.

  10. Cooperation-Controlled Learning for Explicit Class Structure in Self-Organizing Maps

    Science.gov (United States)

    Kamimura, Ryotaro

    2014-01-01

    We attempt to demonstrate the effectiveness of multiple points of view toward neural networks. By restricting ourselves to two points of view of a neuron, we propose a new type of information-theoretic method called “cooperation-controlled learning.” In this method, individual and collective neurons are distinguished from one another, and we suppose that the characteristics of individual and collective neurons are different. To implement individual and collective neurons, we prepare two networks, namely, cooperative and uncooperative networks. The roles of these networks and the roles of individual and collective neurons are controlled by the cooperation parameter. As the parameter is increased, the role of cooperative networks becomes more important in learning, and the characteristics of collective neurons become more dominant. On the other hand, when the parameter is small, individual neurons play a more important role. We applied the method to the automobile and housing data from the machine learning database and examined whether explicit class boundaries could be obtained. Experimental results showed that cooperation-controlled learning, in particular taking into account information on input units, could be used to produce clearer class structure than conventional self-organizing maps. PMID:25309950

  11. Cooperation-Controlled Learning for Explicit Class Structure in Self-Organizing Maps

    Directory of Open Access Journals (Sweden)

    Ryotaro Kamimura

    2014-01-01

    Full Text Available We attempt to demonstrate the effectiveness of multiple points of view toward neural networks. By restricting ourselves to two points of view of a neuron, we propose a new type of information-theoretic method called “cooperation-controlled learning.” In this method, individual and collective neurons are distinguished from one another, and we suppose that the characteristics of individual and collective neurons are different. To implement individual and collective neurons, we prepare two networks, namely, cooperative and uncooperative networks. The roles of these networks and the roles of individual and collective neurons are controlled by the cooperation parameter. As the parameter is increased, the role of cooperative networks becomes more important in learning, and the characteristics of collective neurons become more dominant. On the other hand, when the parameter is small, individual neurons play a more important role. We applied the method to the automobile and housing data from the machine learning database and examined whether explicit class boundaries could be obtained. Experimental results showed that cooperation-controlled learning, in particular taking into account information on input units, could be used to produce clearer class structure than conventional self-organizing maps.

  12. Testing students' e-learning via Facebook through Bayesian structural equation modeling.

    Directory of Open Access Journals (Sweden)

    Hashem Salarzadeh Jenatabadi

    Full Text Available Learning is an intentional activity, with several factors affecting students' intention to use new learning technology. Researchers have investigated technology acceptance in different contexts by developing various theories/models and testing them by a number of means. Although most theories/models developed have been examined through regression or structural equation modeling, Bayesian analysis offers more accurate data analysis results. To address this gap, the unified theory of acceptance and technology use in the context of e-learning via Facebook are re-examined in this study using Bayesian analysis. The data (S1 Data were collected from 170 students enrolled in a business statistics course at University of Malaya, Malaysia, and tested with the maximum likelihood and Bayesian approaches. The difference between the two methods' results indicates that performance expectancy and hedonic motivation are the strongest factors influencing the intention to use e-learning via Facebook. The Bayesian estimation model exhibited better data fit than the maximum likelihood estimator model. The results of the Bayesian and maximum likelihood estimator approaches are compared and the reasons for the result discrepancy are deliberated.

  13. Spatiotemporal Fusion of Remote Sensing Images with Structural Sparsity and Semi-Coupled Dictionary Learning

    Directory of Open Access Journals (Sweden)

    Jingbo Wei

    2016-12-01

    Full Text Available Fusion of remote sensing images with different spatial and temporal resolutions is highly needed by diverse earth observation applications. A small number of spatiotemporal fusion methods using sparse representation appear to be more promising than traditional linear mixture methods in reflecting abruptly changing terrestrial content. However, one of the main difficulties is that the results of sparse representation have reduced expressional accuracy; this is due in part to insufficient prior knowledge. For remote sensing images, the cluster and joint structural sparsity of the sparse coefficients could be employed as a priori knowledge. In this paper, a new optimization model is constructed with the semi-coupled dictionary learning and structural sparsity to predict the unknown high-resolution image from known images. Specifically, the intra-block correlation and cluster-structured sparsity are considered for single-channel reconstruction, and the inter-band similarity of joint-structured sparsity is considered for multichannel reconstruction, and both are implemented with block sparse Bayesian learning. The detailed optimization steps are given iteratively. In the experimental procedure, the red, green, and near-infrared bands of Landsat-7 and Moderate Resolution Imaging Spectrometer (MODIS satellites are put to fusion with root mean square errors to check the prediction accuracy. It can be concluded from the experiment that the proposed methods can produce higher quality than state-of-the-art methods.

  14. LIF: A new Kriging based learning function and its application to structural reliability analysis

    International Nuclear Information System (INIS)

    Sun, Zhili; Wang, Jian; Li, Rui; Tong, Cao

    2017-01-01

    The main task of structural reliability analysis is to estimate failure probability of a studied structure taking randomness of input variables into account. To consider structural behavior practically, numerical models become more and more complicated and time-consuming, which increases the difficulty of reliability analysis. Therefore, sequential strategies of design of experiment (DoE) are raised. In this research, a new learning function, named least improvement function (LIF), is proposed to update DoE of Kriging based reliability analysis method. LIF values how much the accuracy of estimated failure probability will be improved if adding a given point into DoE. It takes both statistical information provided by the Kriging model and the joint probability density function of input variables into account, which is the most important difference from the existing learning functions. Maximum point of LIF is approximately determined with Markov Chain Monte Carlo(MCMC) simulation. A new reliability analysis method is developed based on the Kriging model, in which LIF, MCMC and Monte Carlo(MC) simulation are employed. Three examples are analyzed. Results show that LIF and the new method proposed in this research are very efficient when dealing with nonlinear performance function, small probability, complicated limit state and engineering problems with high dimension. - Highlights: • Least improvement function (LIF) is proposed for structural reliability analysis. • LIF takes both Kriging based statistical information and joint PDF into account. • A reliability analysis method is constructed based on Kriging, MCS and LIF.

  15. Anomaly-sensitive dictionary learning for structural diagnostics from ultrasonic wavefields.

    Science.gov (United States)

    Druce, Jeffrey M; Haupt, Jarvis D; Gonella, Stefano

    2015-07-01

    This paper proposes a strategy for the detection and triangulation of localized anomalies, such as defects, inclusions, or damage zones, in solid and structural media. The method revolves around the construction of sparse representations of the structure's ultrasonic wavefield response, which are obtained by learning instructive dictionaries that form a suitable basis for the response data. The resulting sparse coding problem is cast as a modified dictionary learning task with additional spatial sparsity constraints enforced on the atoms of the learned dictionaries, which provide them with the ability to unveil anomalous regions in the physical domain. The proposed methodology is model-agnostic, i.e., it forsakes the need for a physical model and requires virtually no a priori knowledge of the material properties. This characteristic makes the approach especially powerful for anomaly identification in systems with unknown or highly heterogeneous property distribution, for which a material model is unsuitable or unreliable. The method is tested against synthetically generated data as well as experimental data acquired using a scanning laser Doppler vibrometer.

  16. Alchemical and structural distribution based representation for universal quantum machine learning

    Science.gov (United States)

    Faber, Felix A.; Christensen, Anders S.; Huang, Bing; von Lilienfeld, O. Anatole

    2018-06-01

    We introduce a representation of any atom in any chemical environment for the automatized generation of universal kernel ridge regression-based quantum machine learning (QML) models of electronic properties, trained throughout chemical compound space. The representation is based on Gaussian distribution functions, scaled by power laws and explicitly accounting for structural as well as elemental degrees of freedom. The elemental components help us to lower the QML model's learning curve, and, through interpolation across the periodic table, even enable "alchemical extrapolation" to covalent bonding between elements not part of training. This point is demonstrated for the prediction of covalent binding in single, double, and triple bonds among main-group elements as well as for atomization energies in organic molecules. We present numerical evidence that resulting QML energy models, after training on a few thousand random training instances, reach chemical accuracy for out-of-sample compounds. Compound datasets studied include thousands of structurally and compositionally diverse organic molecules, non-covalently bonded protein side-chains, (H2O)40-clusters, and crystalline solids. Learning curves for QML models also indicate competitive predictive power for various other electronic ground state properties of organic molecules, calculated with hybrid density functional theory, including polarizability, heat-capacity, HOMO-LUMO eigenvalues and gap, zero point vibrational energy, dipole moment, and highest vibrational fundamental frequency.

  17. Robust Online Multi-Task Learning with Correlative and Personalized Structures

    KAUST Repository

    Yang, Peng

    2017-06-29

    Multi-Task Learning (MTL) can enhance a classifier\\'s generalization performance by learning multiple related tasks simultaneously. Conventional MTL works under the offline setting and suffers from expensive training cost and poor scalability. To address such issues, online learning techniques have been applied to solve MTL problems. However, most existing algorithms of online MTL constrain task relatedness into a presumed structure via a single weight matrix, which is a strict restriction that does not always hold in practice. In this paper, we propose a robust online MTL framework that overcomes this restriction by decomposing the weight matrix into two components: the first one captures the low-rank common structure among tasks via a nuclear norm; the second one identifies the personalized patterns of outlier tasks via a group lasso. Theoretical analysis shows the proposed algorithm can achieve a sub-linear regret with respect to the best linear model in hindsight. However, the nuclear norm that simply adds all nonzero singular values together may not be a good low-rank approximation. To improve the results, we use a log-determinant function as a non-convex rank approximation. Experimental results on a number of real-world applications also verify the efficacy of our approaches.

  18. Robust Online Multi-Task Learning with Correlative and Personalized Structures

    KAUST Repository

    Yang, Peng; Zhao, Peilin; Gao, Xin

    2017-01-01

    Multi-Task Learning (MTL) can enhance a classifier's generalization performance by learning multiple related tasks simultaneously. Conventional MTL works under the offline setting and suffers from expensive training cost and poor scalability. To address such issues, online learning techniques have been applied to solve MTL problems. However, most existing algorithms of online MTL constrain task relatedness into a presumed structure via a single weight matrix, which is a strict restriction that does not always hold in practice. In this paper, we propose a robust online MTL framework that overcomes this restriction by decomposing the weight matrix into two components: the first one captures the low-rank common structure among tasks via a nuclear norm; the second one identifies the personalized patterns of outlier tasks via a group lasso. Theoretical analysis shows the proposed algorithm can achieve a sub-linear regret with respect to the best linear model in hindsight. However, the nuclear norm that simply adds all nonzero singular values together may not be a good low-rank approximation. To improve the results, we use a log-determinant function as a non-convex rank approximation. Experimental results on a number of real-world applications also verify the efficacy of our approaches.

  19. Structural Conditions for Collaboration and Learning in Innovation Networks: Using an Innovation System Performance Lens to Analyse Agricultural Knowledge Systems

    NARCIS (Netherlands)

    Hermans, F.; Klerkx, L.W.A.; Roep, D.

    2015-01-01

    Purpose: We investigate how the structural conditions of eight different European agricultural innovation systems can facilitate or hinder collaboration and social learning in multidisciplinary innovation networks. Methodology: We have adapted the Innovation System Failure Matrix to investigate the

  20. LOG: Analyzing navigation trough a tutorial of Radiation Protection

    International Nuclear Information System (INIS)

    Vega, J. M.; Pena, J. J.; Rossell, M. A.; Calvo, J. L.

    2003-01-01

    Every day, the number of didactic materials presented through Internet, is greater. However, we have not effective tools to obtain the potential academic yield of such a media. The complexity of the Internet protocols, in spite of the easy handling, makes it almost impossible. In this work, a didactic tool to analyse graphically the navigation through a tutorial on radiation protection is presented. For its visualisation, some subjects related with the biogical effects of radiation and with radiological quantities and units have been selected. The graphical representation shows the tour travelled by the user, in our case students of Medicine, and the time employed in eyeing each one of the nodes. The answers to problems about the contents of each node and its graphical representation in the navigation map allow us to follow the learning progress of the students as well as their standard of navigation. The graphical representation analysis of multiple users permits to detect some of the mistakes in the design of the tutorial and to suggest to the author a method for amending these mistakes. The system is developed on LINEX, but it is easily adaptable to other operating systems. (Author) 7 refs

  1. Do Sophisticated Epistemic Beliefs Predict Meaningful Learning? Findings from a Structural Equation Model of Undergraduate Biology Learning

    Science.gov (United States)

    Lee, Silvia Wen-Yu; Liang, Jyh-Chong; Tsai, Chin-Chung

    2016-01-01

    This study investigated the relationships among college students' epistemic beliefs in biology (EBB), conceptions of learning biology (COLB), and strategies of learning biology (SLB). EBB includes four dimensions, namely "multiple-source," "uncertainty," "development," and "justification." COLB is further…

  2. Understanding ill-structured engineering ethics problems through a collaborative learning and argument visualization approach.

    Science.gov (United States)

    Hoffmann, Michael; Borenstein, Jason

    2014-03-01

    As a committee of the National Academy of Engineering recognized, ethics education should foster the ability of students to analyze complex decision situations and ill-structured problems. Building on the NAE's insights, we report about an innovative teaching approach that has two main features: first, it places the emphasis on deliberation and on self-directed, problem-based learning in small groups of students; and second, it focuses on understanding ill-structured problems. The first innovation is motivated by an abundance of scholarly research that supports the value of deliberative learning practices. The second results from a critique of the traditional case-study approach in engineering ethics. A key problem with standard cases is that they are usually described in such a fashion that renders the ethical problem as being too obvious and simplistic. The practitioner, by contrast, may face problems that are ill-structured. In the collaborative learning environment described here, groups of students use interactive and web-based argument visualization software called "AGORA-net: Participate - Deliberate!". The function of the software is to structure communication and problem solving in small groups. Students are confronted with the task of identifying possible stakeholder positions and reconstructing their legitimacy by constructing justifications for these positions in the form of graphically represented argument maps. The argument maps are then presented in class so that these stakeholder positions and their respective justifications become visible and can be brought into a reasoned dialogue. Argument mapping provides an opportunity for students to collaborate in teams and to develop critical thinking and argumentation skills.

  3. Overview of the Kinematics of the Salton Trough and Northern Gulf of California

    Science.gov (United States)

    Stock, J. M.

    2016-12-01

    In the Salton Trough and Northern Gulf of California, transtensional rifting is leading to full continental plate breakup, as a major continental block is being transferred to an oceanic plate. Since at least 6 Ma this region has taken up most of the plate boundary slip between the Pacific and North America plates at this latitude. We review the structural history of plate separation, as constrained by many recent studies of present and past fault configurations, seismicity, and basin development as seen from geology and geophysics. Modern activity in the USA is dominated by NW-striking strike-slip faults (San Andreas, San Jacinto, Elsinore), and subsidiary NE-striking faults. There is an equally broad zone in Mexico (faults from the Mexicali Valley to the Colorado River Delta and bounding the Laguna Salada basin), including active low-angle detachment faults. In both areas, shifts in fault activity are indicated by buried faults and exhumed or buried earlier basin strata. Seismicity defines 3 basin segments in the N Gulf: Consag-Wagner, Upper Delfin, and Lower Delfin, but localization is incomplete. These basins occupy a broad zone of modern deformation, lacking single transform faults, although major strike-slip faults formed in the surrounding continental area. The off-boundary deformation on the western side of the plate boundary has changed with time, as seen by Holocene and Quaternary faults controlling modern basins in the Gulf Extensional Province of NE Baja California, and stranded Pliocene continental and marine basin strata in subaerial fault blocks. The eastern side of the plate boundary, in the shallow northeastern Gulf, contains major NW-striking faults that may have dominated the earlier (latest Miocene-early Pliocene) kinematics. The Sonoran coastal plain likely buries additional older faults and basin sequences; further studies here are needed to refine models of the earlier structural development of this sector. Despite > 250 km of plate

  4. Structural Validity of the WISC-IV for Students With Learning Disabilities.

    Science.gov (United States)

    Styck, Kara M; Watkins, Marley W

    2016-01-01

    The structural validity of the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) was evaluated using confirmatory factor analysis for a clinical sample of 1,537 students diagnosed with specific learning disabilities (SLD) by school psychologists in two large southwestern school districts. Results indicated that a bifactor model consisting of four first-order domain specific factors and a general intelligence breadth factor fit the data best. Consequently, the structural validity of the WISC-IV for students with SLD was supported by the results of the present study. The general intelligence factor contributed the most information, accounting for 48% of the common variance. Given this structure, it was recommended that score interpretation should emphasize the Full-Scale IQ score because of the marginal contributions of the first-order domain-specific factors and their low precision of measurement independent of the general factor. © Hammill Institute on Disabilities 2014.

  5. Effectiveness of creative and productive instructional method towards students' learning achievement in steel structure course

    Science.gov (United States)

    Sugiyanto, Pribadi, Supriyanto, Bambang

    2017-09-01

    The purpose of this study was to investigate the effectiveness of Creative & Productive instructional method compared with conventional method. This research was a quasi-experimental study involving all Civil Engineering students at Universitas Negeri Malang who were taking a course of Steel Structure. The students were randomly assigned to two different treatment groups, 30 students in experimental group and 37 students in the control group. It was assumed that these groups were equal in all relevant aspects; they differed only in the treatment administered. We used the t-test to test the hypothesis. The results of this research suggest that: (l) the use of Creative & Productive instructional method can significantly improve students' learning achievement, (2) the use of Creative & Productive instructional method can significantly improve students' retention, (3) students' motivation has a significant effect on their learning achievement, and (4) students' motivation has a significant effect on their retention.

  6. Incremental Structured Dictionary Learning for Video Sensor-Based Object Tracking

    Science.gov (United States)

    Xue, Ming; Yang, Hua; Zheng, Shibao; Zhou, Yi; Yu, Zhenghua

    2014-01-01

    To tackle robust object tracking for video sensor-based applications, an online discriminative algorithm based on incremental discriminative structured dictionary learning (IDSDL-VT) is presented. In our framework, a discriminative dictionary combining both positive, negative and trivial patches is designed to sparsely represent the overlapped target patches. Then, a local update (LU) strategy is proposed for sparse coefficient learning. To formulate the training and classification process, a multiple linear classifier group based on a K-combined voting (KCV) function is proposed. As the dictionary evolves, the models are also trained to timely adapt the target appearance variation. Qualitative and quantitative evaluations on challenging image sequences compared with state-of-the-art algorithms demonstrate that the proposed tracking algorithm achieves a more favorable performance. We also illustrate its relay application in visual sensor networks. PMID:24549252

  7. Incremental Structured Dictionary Learning for Video Sensor-Based Object Tracking

    Directory of Open Access Journals (Sweden)

    Ming Xue

    2014-02-01

    Full Text Available To tackle robust object tracking for video sensor-based applications, an online discriminative algorithm based on incremental discriminative structured dictionary learning (IDSDL-VT is presented. In our framework, a discriminative dictionary combining both positive, negative and trivial patches is designed to sparsely represent the overlapped target patches. Then, a local update (LU strategy is proposed for sparse coefficient learning. To formulate the training and classification process, a multiple linear classifier group based on a K-combined voting (KCV function is proposed. As the dictionary evolves, the models are also trained to timely adapt the target appearance variation. Qualitative and quantitative evaluations on challenging image sequences compared with state-of-the-art algorithms demonstrate that the proposed tracking algorithm achieves a more favorable performance. We also illustrate its relay application in visual sensor networks.

  8. The helpfulness of category labels in semi-supervised learning depends on category structure.

    Science.gov (United States)

    Vong, Wai Keen; Navarro, Daniel J; Perfors, Amy

    2016-02-01

    The study of semi-supervised category learning has generally focused on how additional unlabeled information with given labeled information might benefit category learning. The literature is also somewhat contradictory, sometimes appearing to show a benefit to unlabeled information and sometimes not. In this paper, we frame the problem differently, focusing on when labels might be helpful to a learner who has access to lots of unlabeled information. Using an unconstrained free-sorting categorization experiment, we show that labels are useful to participants only when the category structure is ambiguous and that people's responses are driven by the specific set of labels they see. We present an extension of Anderson's Rational Model of Categorization that captures this effect.

  9. Action Learning: A New Method to Increase Tractor Rollover Protective Structure (ROPS) Adoption

    Science.gov (United States)

    Biddle, Elyce Anne; Keane, Paul R.

    2016-01-01

    Action Learning is a problem-solving process that is used in various industries to address difficult problems. This project applied Action Learning to a leading problem in agricultural safety. Tractor overturns are the leading cause of fatal injury to farmworkers. This cause of injury is preventable using rollover protective structures (ROPS), protective equipment that functions as a roll bar structure to protect the operator in the event of an overturn. For agricultural tractors manufactured after 1976 and employee operated, Occupational Safety and Health Administration (OSHA) regulation requires employers to equip them with ROPS and seat belts. By the mid-1980s, US tractor manufacturers began adding ROPS on all farm tractors over 20 horsepower sold in the United States (http://www.nasdonline.org/document/113/d001656/rollover-protection-for-farm-tractor-operators.html). However, many older tractors remain in use without ROPS, putting tractor operators at continued risk for traumatic injury and fatality. For many older tractor models ROPS are available for retrofit, but for a variety of reasons, tractor owners have not chosen to retrofit those ROPS. The National Institute for Occupational Safety and Health (NIOSH) attempted various means to ameliorate this occupational safety risk, including the manufacture of a low-cost ROPS for self-assembly. Other approaches address barriers to adoption. An Action Learning approach to increasing adoption of ROPS was followed in Virginia and New York, with mixed results. Virginia took action to increase the manufacturing and adoption of ROPS, but New York saw problems that would be insurmountable. Increased focus on team composition might be needed to establish effective Action Learning teams to address this problem. PMID:22994641

  10. Structured learning and self-reflection: strategies to decrease anxiety in the psychiatric mental health clinical nursing experience.

    Science.gov (United States)

    Ganzer, Christine Anne; Zauderer, Cheryl

    2013-01-01

    The purpose of this qualitative study was to test a teaching-learning strategy to help nursing students decrease stress and anxiety that may be brought about by the psychiatric mental health clinical experience. Undergraduate nursing students are known to experience affective stress prior to their first psychiatric mental health clinical practicum. A stressful learning environment can affect the success of the student's clinical performance. Thirty nursing students participated in this study. A structured preclinical workshop combined with self-reflection provided insight into students' perceptions of the psychiatric mental health clinical experience. Overall, students reported that participating in the teaching-learning strategy and self-reflection helped mitigate Combining structured learning with self-reflection is a useful tool for helping nursing students increase self-awareness and ease anxiety that may interfere with learning.

  11. Hippocampal Structure Predicts Statistical Learning and Associative Inference Abilities during Development.

    Science.gov (United States)

    Schlichting, Margaret L; Guarino, Katharine F; Schapiro, Anna C; Turk-Browne, Nicholas B; Preston, Alison R

    2017-01-01

    Despite the importance of learning and remembering across the lifespan, little is known about how the episodic memory system develops to support the extraction of associative structure from the environment. Here, we relate individual differences in volumes along the hippocampal long axis to performance on statistical learning and associative inference tasks-both of which require encoding associations that span multiple episodes-in a developmental sample ranging from ages 6 to 30 years. Relating age to volume, we found dissociable patterns across the hippocampal long axis, with opposite nonlinear volume changes in the head and body. These structural differences were paralleled by performance gains across the age range on both tasks, suggesting improvements in the cross-episode binding ability from childhood to adulthood. Controlling for age, we also found that smaller hippocampal heads were associated with superior behavioral performance on both tasks, consistent with this region's hypothesized role in forming generalized codes spanning events. Collectively, these results highlight the importance of examining hippocampal development as a function of position along the hippocampal axis and suggest that the hippocampal head is particularly important in encoding associative structure across development.

  12. Aero Engine Component Fault Diagnosis Using Multi-Hidden-Layer Extreme Learning Machine with Optimized Structure

    Directory of Open Access Journals (Sweden)

    Shan Pang

    2016-01-01

    Full Text Available A new aero gas turbine engine gas path component fault diagnosis method based on multi-hidden-layer extreme learning machine with optimized structure (OM-ELM was proposed. OM-ELM employs quantum-behaved particle swarm optimization to automatically obtain the optimal network structure according to both the root mean square error on training data set and the norm of output weights. The proposed method is applied to handwritten recognition data set and a gas turbine engine diagnostic application and is compared with basic ELM, multi-hidden-layer ELM, and two state-of-the-art deep learning algorithms: deep belief network and the stacked denoising autoencoder. Results show that, with optimized network structure, OM-ELM obtains better test accuracy in both applications and is more robust to sensor noise. Meanwhile it controls the model complexity and needs far less hidden nodes than multi-hidden-layer ELM, thus saving computer memory and making it more efficient to implement. All these advantages make our method an effective and reliable tool for engine component fault diagnosis tool.

  13. Machine-learning scoring functions to improve structure-based binding affinity prediction and virtual screening.

    Science.gov (United States)

    Ain, Qurrat Ul; Aleksandrova, Antoniya; Roessler, Florian D; Ballester, Pedro J

    2015-01-01

    Docking tools to predict whether and how a small molecule binds to a target can be applied if a structural model of such target is available. The reliability of docking depends, however, on the accuracy of the adopted scoring function (SF). Despite intense research over the years, improving the accuracy of SFs for structure-based binding affinity prediction or virtual screening has proven to be a challenging task for any class of method. New SFs based on modern machine-learning regression models, which do not impose a predetermined functional form and thus are able to exploit effectively much larger amounts of experimental data, have recently been introduced. These machine-learning SFs have been shown to outperform a wide range of classical SFs at both binding affinity prediction and virtual screening. The emerging picture from these studies is that the classical approach of using linear regression with a small number of expert-selected structural features can be strongly improved by a machine-learning approach based on nonlinear regression allied with comprehensive data-driven feature selection. Furthermore, the performance of classical SFs does not grow with larger training datasets and hence this performance gap is expected to widen as more training data becomes available in the future. Other topics covered in this review include predicting the reliability of a SF on a particular target class, generating synthetic data to improve predictive performance and modeling guidelines for SF development. WIREs Comput Mol Sci 2015, 5:405-424. doi: 10.1002/wcms.1225 For further resources related to this article, please visit the WIREs website.

  14. Face-name association learning and brain structural substrates in alcoholism.

    Science.gov (United States)

    Pitel, Anne-Lise; Chanraud, Sandra; Rohlfing, Torsten; Pfefferbaum, Adolf; Sullivan, Edith V

    2012-07-01

    Associative learning is required for face-name association and is impaired in alcoholism, but the cognitive processes and brain structural components underlying this deficit remain unclear. It is also unknown whether prompting alcoholics to implement a deep level of processing during face-name encoding would enhance performance. Abstinent alcoholics and controls performed a levels-of-processing face-name learning task. Participants indicated whether the face was that of an honest person (deep encoding) or that of a man (shallow encoding). Retrieval was examined using an associative (face-name) recognition task and a single-item (face or name only) recognition task. Participants also underwent 3T structural MRI. Compared with controls, alcoholics had poorer associative and single-item learning and performed at similar levels. Level of processing at encoding had little effect on recognition performance but affected reaction time (RT). Correlations with brain volumes were generally modest and based primarily on RT in alcoholics, where the deeper the processing at encoding, the more restricted the correlations with brain volumes. In alcoholics, longer control task RTs correlated modestly with smaller tissue volumes across several anterior to posterior brain regions; shallow encoding correlated with calcarine and striatal volumes; deep encoding correlated with precuneus and parietal volumes; and associative recognition RT correlated with cerebellar volumes. In controls, poorer associative recognition with deep encoding correlated significantly with smaller volumes of frontal and striatal structures. Despite prompting, alcoholics did not take advantage of encoding memoranda at a deep level to enhance face-name recognition accuracy. Nonetheless, conditions of deeper encoding resulted in faster RTs and more specific relations with regional brain volumes than did shallow encoding. The normal relation between associative recognition and corticostriatal volumes was not

  15. Education, premise for a workforce reconversion trough a Professional Reinvention

    Directory of Open Access Journals (Sweden)

    Jornea Eugenia

    2017-01-01

    Full Text Available The diversity of resources, made in the 1980-1990 years from Hunedoara County the most industrialized county of Romania. Hunedoara is today one of the most affected by unemployment, poverty and crime. Today Hunedoara is a county that decreased with 140,000 inhabitants in the last 20 years and 75,000 jobs lost, all of these bearing the seal of deindustrialization. An accurate professional framework, could allow the attracting of investors. A first step should be a study of the age and socio professional structure of the population of Hunedoara County, could permit in the next years on focusing to the education of undergraduate and graduate level workforce in the area.

  16. Structural reliability analysis under evidence theory using the active learning kriging model

    Science.gov (United States)

    Yang, Xufeng; Liu, Yongshou; Ma, Panke

    2017-11-01

    Structural reliability analysis under evidence theory is investigated. It is rigorously proved that a surrogate model providing only correct sign prediction of the performance function can meet the accuracy requirement of evidence-theory-based reliability analysis. Accordingly, a method based on the active learning kriging model which only correctly predicts the sign of the performance function is proposed. Interval Monte Carlo simulation and a modified optimization method based on Karush-Kuhn-Tucker conditions are introduced to make the method more efficient in estimating the bounds of failure probability based on the kriging model. Four examples are investigated to demonstrate the efficiency and accuracy of the proposed method.

  17. Curriculum structure, content, learning and assessment in European undergraduate dental education - update 2010.

    LENUS (Irish Health Repository)

    Manogue, M

    2011-08-01

    This paper presents an updated statement on behalf of the Association for Dental Education in Europe (ADEE) in relation to proposals for undergraduate Curriculum Structure, Content, Learning, Assessment and Student \\/ Staff Exchange for dental education in Europe. A task force was constituted to consider these issues and the two previous, related publications produced by the Association (Plasschaert et al 2006 and 2007) were revised. The broad European dental community was circulated and contributed to the revisions. The paper was approved at the General Assembly of ADEE, held in Amsterdam in August 2010 and will be updated again in 2015.

  18. Secondary Structure Prediction of Protein using Resilient Back Propagation Learning Algorithm

    Directory of Open Access Journals (Sweden)

    Jyotshna Dongardive

    2015-12-01

    Full Text Available The paper proposes a neural network based approach to predict secondary structure of protein. It uses Multilayer Feed Forward Network (MLFN with resilient back propagation as the learning algorithm. Point Accepted Mutation (PAM is adopted as the encoding scheme and CB396 data set is used for the training and testing of the network. Overall accuracy of the network has been experimentally calculated with different window sizes for the sliding window scheme and by varying the number of units in the hidden layer. The best results were obtained with eleven as the window size and seven as the number of units in the hidden layer.

  19. On-the-Fly Machine Learning of Atomic Potential in Density Functional Theory Structure Optimization

    Science.gov (United States)

    Jacobsen, T. L.; Jørgensen, M. S.; Hammer, B.

    2018-01-01

    Machine learning (ML) is used to derive local stability information for density functional theory calculations of systems in relation to the recently discovered SnO2 (110 )-(4 ×1 ) reconstruction. The ML model is trained on (structure, total energy) relations collected during global minimum energy search runs with an evolutionary algorithm (EA). While being built, the ML model is used to guide the EA, thereby speeding up the overall rate by which the EA succeeds. Inspection of the local atomic potentials emerging from the model further shows chemically intuitive patterns.

  20. An empirical comparison of popular structure learning algorithms with a view to gene network inference

    Czech Academy of Sciences Publication Activity Database

    Djordjilović, V.; Chiogna, M.; Vomlel, Jiří

    2017-01-01

    Roč. 88, č. 1 (2017), s. 602-613 ISSN 0888-613X R&D Projects: GA ČR(CZ) GA16-12010S Institutional support: RVO:67985556 Keywords : Bayesian networks * Structure learning * Reverse engineering * Gene networks Subject RIV: JD - Computer Applications, Robotics OBOR OECD: Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8) Impact factor: 2.845, year: 2016 http://library.utia.cas.cz/separaty/2017/MTR/vomlel-0477168.pdf

  1. Using machine learning to identify structural breaks in single-group interrupted time series designs.

    Science.gov (United States)

    Linden, Ariel; Yarnold, Paul R

    2016-12-01

    Single-group interrupted time series analysis (ITSA) is a popular evaluation methodology in which a single unit of observation is being studied, the outcome variable is serially ordered as a time series and the intervention is expected to 'interrupt' the level and/or trend of the time series, subsequent to its introduction. Given that the internal validity of the design rests on the premise that the interruption in the time series is associated with the introduction of the treatment, treatment effects may seem less plausible if a parallel trend already exists in the time series prior to the actual intervention. Thus, sensitivity analyses should focus on detecting structural breaks in the time series before the intervention. In this paper, we introduce a machine-learning algorithm called optimal discriminant analysis (ODA) as an approach to determine if structural breaks can be identified in years prior to the initiation of the intervention, using data from California's 1988 voter-initiated Proposition 99 to reduce smoking rates. The ODA analysis indicates that numerous structural breaks occurred prior to the actual initiation of Proposition 99 in 1989, including perfect structural breaks in 1983 and 1985, thereby casting doubt on the validity of treatment effects estimated for the actual intervention when using a single-group ITSA design. Given the widespread use of ITSA for evaluating observational data and the increasing use of machine-learning techniques in traditional research, we recommend that structural break sensitivity analysis is routinely incorporated in all research using the single-group ITSA design. © 2016 John Wiley & Sons, Ltd.

  2. DEVELOPMENT AND PRELIMINARY TESTING OF A PARABOLIC TROUGH SOLAR WATER HEATER

    Directory of Open Access Journals (Sweden)

    O. A. Lasode

    2011-06-01

    Full Text Available Solar energy is a high-temperature, high-energy radiant energy source, with tremendous advantages over other alternative energy sources. It is a reliable, robust renewable resource which is largely undeveloped. The design and fabrication of parabolic trough solar water heater for water heating was executed. The procedure employed includes the design, construction and testing stages. The equipment which is made up of the reflector surface (curved mirror, reflector support, absorber pipe and a stand was fabricated using locally sourced materials. The results obtained. compared favourably with other research works in the literature. It depicts that employing a suitable design, selection of time of heating and proper focusing of the reflected rays to the focal spot region, solar radiation can efficiently be utilized for water heating in a tropical environment. This work presents a parabolic trough solar water heater as a suitable renewable energy technology for reducing water-heating costs.

  3. Interseismic Coupling-Based Earthquake and Tsunami Scenarios for the Nankai Trough

    Science.gov (United States)

    Baranes, H.; Woodruff, J. D.; Loveless, J. P.; Hyodo, M.

    2018-04-01

    Theoretical modeling and investigations of recent subduction zone earthquakes show that geodetic estimates of interseismic coupling and the spatial distribution of coseismic rupture are correlated. However, the utility of contemporary coupling in guiding construction of rupture scenarios has not been evaluated on the world's most hazardous faults. Here we demonstrate methods for scaling coupling to slip to create rupture models for southwestern Japan's Nankai Trough. Results show that coupling-based models produce distributions of ground surface deformation and tsunami inundation that are similar to historical and geologic records of the largest known Nankai earthquake in CE 1707 and to an independent, quasi-dynamic rupture model. Notably, these models and records all support focused subsidence around western Shikoku that makes the region particularly vulnerable to flooding. Results imply that contemporary coupling mirrors the slip distribution of a full-margin, 1707-type rupture, and Global Positioning System measurements of surface motion are connected with the trough's physical characteristics.

  4. Heat Loss Testing of Schott's 2008 PTR70 Parabolic Trough Receiver

    Energy Technology Data Exchange (ETDEWEB)

    Burkholder, Frank [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kutscher, Chuck [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2009-05-01

    Two Schott 2008 model year PTR70 HCEs were tested on NREL's heat loss test stand from 100 - 500 deg C in 50 deg C increments. Absorber emittance was determined from the laboratory testing so that the performance of the HCEs could be modeled in a parabolic trough collector. Collector/HCE simulation results for many different field operation conditions were used to create heat loss correlationcoefficients for Excelergy and SAM. SAM estimates that the decreased emittance of the 2008 PTR70 will decrease the LCOE for parabolic trough power plants by 0.5 cents/kWh and increase the electricity generated by 5% relative to previous PTR70s. These conclusions assume that the 2008 PTR70 is supplied at the same cost and with the same optical performance as earlier PTR70 models.

  5. Seismic stratigraphic architecture of the Disko Bay trough-mouth fan system, West Greenland

    Science.gov (United States)

    Hofmann, Julia C.; Knutz, Paul C.

    2015-04-01

    Spatial and temporal changes of the Greenland Ice Sheet on the continental shelf bordering Baffin Bay remain poorly constrained. Then as now, fast-flowing ice streams and outlet glaciers have played a key role for the mass balance and stability of polar ice sheets. Despite their significance for Greenland Ice Sheet dynamics and evolution, our understanding of their long-term behaviour is limited. The central West Greenland margin is characterized by a broad continental shelf where a series of troughs extend from fjords to the shelf margin, acting as focal points for trough-mouth fan (TMF) accummulations. The sea-ward bulging morphology and abrupt shelf-break of these major depositional systems is generated by prograding depocentres that formed during glacial maxima when ice streams reached the shelf edge, delivering large amounts of subglacial sediment onto the continental slope (Ó Cofaigh et al., 2013). The aim of this study is to unravel the seismic stratigraphic architecture and depositional processes of the Disko Bay TMF, aerially the largest single sedimentary system in West Greenland, using 2D and 3D seismic reflection data, seabed bathymetry and stratigraphic information from exploration well Hellefisk-1. The south-west Disko Bay is intersected by a deep, narrow trough, Egedesminde Dyb, which extends towards the southwest and links to the shallower and broader cross-shelf Disko Trough (maximum water depths of > 1000 m and a trough length of c. 370 km). Another trough-like depression (trough length of c. 120 km) in the northern part of the TMF, indicating a previous position of the ice stream, can be distinguished on the seabed topographic map and the seismic images. The Disko Bay TMF itself extends from the shelf edge down to the abyssal plain (abyssal floor depths of 2000 m) of the southern Baffin Bay. Based on seismic stratigraphic configurations relating to reflection terminations, erosive patterns and seismic facies (Mitchum et al., 1977), the TMF

  6. Sensitivity analysis on the effect of key parameters on the performance of parabolic trough solar collectors

    Science.gov (United States)

    Muhlen, Luis S. W.; Najafi, Behzad; Rinaldi, Fabio; Marchesi, Renzo

    2014-04-01

    Solar troughs are amongst the most commonly used technologies for collecting solar thermal energy and any attempt to increase the performance of these systems is welcomed. In the present study a parabolic solar trough is simulated using a one dimensional finite element model in which the energy balances for the fluid, the absorber and the envelope in each element are performed. The developed model is then validated using the available experimental data . A sensitivity analysis is performed in the next step in order to study the effect of changing the type of the working fluid and the corresponding Reynolds number on the overall performance of the system. The potential improvement due to the addition of a shield on the upper half of the annulus and enhancing the convection coefficient of the heat transfer fluid is also studied.

  7. Sensitivity analysis on the effect of key parameters on the performance of parabolic trough solar collectors

    International Nuclear Information System (INIS)

    Muhlen, Luis S W; Najafi, Behzad; Rinaldi, Fabio; Marchesi, Renzo

    2014-01-01

    Solar troughs are amongst the most commonly used technologies for collecting solar thermal energy and any attempt to increase the performance of these systems is welcomed. In the present study a parabolic solar trough is simulated using a one dimensional finite element model in which the energy balances for the fluid, the absorber and the envelope in each element are performed. The developed model is then validated using the available experimental data . A sensitivity analysis is performed in the next step in order to study the effect of changing the type of the working fluid and the corresponding Reynolds number on the overall performance of the system. The potential improvement due to the addition of a shield on the upper half of the annulus and enhancing the convection coefficient of the heat transfer fluid is also studied.

  8. Study on a Mid-Temperature Trough Solar Collector with Multisurface Concentration

    Directory of Open Access Journals (Sweden)

    Zhengliang Li

    2015-01-01

    Full Text Available A new trough solar concentrator which is composed of multiple reflection surfaces is developed in this paper. The concentrator was analyzed firstly by using optical software. The variation curves of the collecting efficiency affected by tracking error and the deviation angle were given out. It is found that the deviation tolerance for the collector tracking system is about 8 degrees when the receiver is a 90 mm flat. The trough solar concentrators were tested under real weather conditions. The experiment results indicate that, the new solar concentrator was validated to have relative good collecting efficiency, which can be more than 45 percent when it operated in more 145°C. It also has the characteristics of rdust, wind, and snow resistance and low tracking precision requirements.

  9. Studies of sporadic E (Es) associated with the main ionospheric trough

    International Nuclear Information System (INIS)

    Rodger, A.S.; Morrell, C.; Dudeney, J.R.

    1983-01-01

    Sporadic E, or E(s) events under the main F region trough have been confirmed on the basis of ionograms from a vertical incidence ionosonde at Halley Bay, Antarctica. Analyses indicate that E(s) is frequently observable under both the equatorward and the poleward edges of the trough, as well as poleward of it. Before magnetic midnight, E(s) layers whose semithickness resembles those of the normal E layer are common, in contrast to layers seen after magnetic midnight which show the characteristics of thin E(s) layers. A possible explanation of the observed change in the E(s) layer characteristics at magnetic midnight is related to differences in the type and spectra of the precipitating particles. It is shown that the redistribution of ionization by the convection electric field may be important. 40 references

  10. Biogeochemical processes controlling authigenic carbonate formation within the sediment column from the Okinawa Trough

    Science.gov (United States)

    Li, Jiwei; Peng, Xiaotong; Bai, Shijie; Chen, Zhiyan; Van Nostrand, Joy D.

    2018-02-01

    Authigenic carbonates are one type of conspicuous manifestation in seep environments that can provide long-term archives of past seepage activity and methane cycling in the oceans. Comprehensive investigations of the microbial community functional structure and their roles in the process of carbonate formation are, however, lacking. In this study, the mineralogical, geochemical, and microbial functional composition were examined in seep carbonate deposits collected from the west slope of the northern section of the Okinawa Trough (OT). The aim of this work was to explore the correspondence between the mineralogical phases and microbial metabolism during carbonate deposit formation. The mineralogical analyses indicated that authigenic carbonate minerals (aragonite, magnesium-rich calcite, dolomite, ankerite and siderite) and iron-bearing minerals (limonite, chlorite, and biotite) were present in these carbonate samples. The carbon and oxygen isotopic values of the carbonate samples varied between -51.1‰ to -4.7‰ and -4.8‰ to 3.7‰, respectively. A negative linear correlation between carbon and oxygen isotopic compositions was found, indicating a mixture of methane-derived diagenetic (low δ13C/high 18O) carbonates and detrital origin (high δ13C/low 18O) carbonates at the OT. GeoChip analyses suggested that various metabolic activities of microorganisms, including methanogenesis, methane oxidation, sulfite oxidation, sulfate reduction, and metal biotransformations, all occurred during the formation process. On the basis of these findings, the following model for the methane cycle and seep carbonate deposit formation in the sediment column at the OT is proposed: (1) in the upper oxidizing zone, aerobic methane oxidation was the main way of methane consumption; (2) in the sulfate methane transition zone, sulfate-dependent AOM (anaerobic oxidation of methane) consumes methane, and authigenic minerals such as aragonite, magnesium-calcite, and sulfide minerals

  11. Triggered surface slips in the Salton Trough associated with the 1999 Hector Mine, California, earthquake

    Science.gov (United States)

    Rymer, M.J.; Boatwright, J.; Seekins, L.C.; Yule, J.D.; Liu, J.

    2002-01-01

    Surface fracturing occurred along the southern San Andreas, Superstition Hills, and Imperial faults in association with the 16 October 1999 (Mw 7.1) Hector Mine earthquake, making this at least the eighth time in the past 31 years that a regional earthquake has triggered slip along faults in the Salton Trough. Fractures associated with the event formed discontinuous breaks over a 39-km-long stretch of the San Andreas fault, from the Mecca Hills southeastward to Salt Creek and Durmid Hill, a distance from the epicenter of 107 to 139 km. Sense of slip was right lateral; only locally was there a minor (~1 mm) vertical component of slip. Dextral slip ranged from 1 to 13 mm. Maximum slip values in 1999 and earlier triggered slips are most common in the central Mecca Hills. Field evidence indicates a transient opening as the Hector Mine seismic waves passed the southern San Andreas fault. Comparison of nearby strong-motion records indicates several periods of relative opening with passage of the Hector Mine seismic wave-a similar process may have contributed to the field evidence of a transient opening. Slip on the Superstition Hills fault extended at least 9 km, at a distance from the Hector Mine epicenter of about 188 to 196 km. This length of slip is a minimum value, because we saw fresh surface breakage extending farther northwest than our measurement sites. Sense of slip was right lateral; locally there was a minor (~1 mm) vertical component of slip. Dextral slip ranged from 1 to 18 mm, with the largest amounts found distributed (or skewed) away from the Hector Mine earthquake source. Slip triggered on the Superstition Hills fault commonly is skewed away from the earthquake source, most notably in 1968, 1979, and 1999. Surface slip on the Imperial fault and within the Imperial Valley extended about 22 km, representing a distance from the Hector Mine epicenter of about 204 to 226 km. Sense of slip dominantly was right lateral; the right-lateral component of slip

  12. Sedimentary response to volcanic activity in the Okinawa Trough since the last deglaciation

    Institute of Scientific and Technical Information of China (English)

    蒋富清; 李安春; 李铁刚

    2010-01-01

    To investigate the relationship between volcanic activity and sediment record on regional and temporal scales,158 surface sediment samples were collected from the East China Sea Shelf to the northern Okinawa Trough (OT),and two cores recovered in the northern and southern OT,respectively.Mineralogy,grain-size,and geochemical analyses of those samples show that:1) volcanic glass,volcanic-type pyroxene,hypersthenes,and magnetite increase in sediment influenced by volcanic activity;2) sediment grain sizes (and...

  13. Simulation of the parabolic trough solar energy generation system with Organic Rankine Cycle

    International Nuclear Information System (INIS)

    He, Ya-Ling; Mei, Dan-Hua; Tao, Wen-Quan; Yang, Wei-Wei; Liu, Huai-Liang

    2012-01-01

    Highlights: ► A parabolic trough solar power generation system with ORC is numerically simulated. ► The effects of key parameters on collector field and system performance are studied. ► Collector heat loss increases with small absorber and glass tube interlayer pressure. ► Heat collecting efficiency increases with initial increase of absorber HTO flow rate. ► Recommended thermal storage system volumes are different in year four typical days. -- Abstract: A model for a typical parabolic trough solar thermal power generation system with Organic Rankine Cycle (PT-SEGS–ORC) was built within the transient energy simulation package TRNSYS, which is formed by integrating several submodels for the trough collector system, the single-tank thermal storage system, the auxiliary power system and the heat-electricity conversion system. With this model, the effects of several key parameters, including the interlayer pressure between the absorber tube and the glass tube (p inter ), the flow rate of high temperature oil in the absorber tube (v), solar radiation intensity (I dn ) and incidence angle (θ), on the performance of the parabolic trough collector field based on the meteorological data of Xi’an city were examined. The study shows that the heat loss of the solar collector (q loss ) increases sharply with the increase in p inter at beginning and then reaches to an approximately constant value. The variation of heat collecting efficiency (η hc ) with v is quite similar to the variation of q loss with p inter . However, I dn and θ exhibit opposite effect on η hc . In addition, it is found that the optimal volume of the thermal storage system is sensitively dependent on the solar radiation intensity. The optimal volumes are 100, 150, 50, and 0 m 3 for spring equinox, summer solstice, autumnal equinox and winter solstice, respectively.

  14. Main Ionospheric Trough and Equatorial Ionization Anomaly During Substorms With the Different UT Onset Moments

    Science.gov (United States)

    Klimenko, M. V.; Klimenko, V. V.; Bryukhanov, V. V.

    2007-05-01

    In the given work the numerical calculation results of ionospheric effects of four modeling substorms which have begun in 00, 06, 12 and 18 UT are presented. Calculations are executed on the basis of Global Self-consistent Model of the Thermosphere, Ionosphere and Protonosphere (GSM TIP), developed in WD IZMIRAN, added by the new block of calculation of electric fields in the ionosphere of the Earth for vernal equinox conditions in the minimum of solar activity. In calculations we considered superposition of magnetospheric convection electric field (at set potential differences through polar caps and field aligned currents of the second zone with taking into account of particle precipitation) and dynamo field generated by thermospheric winds without taking into account the tides. It is shown, that in the given statement of problem the substorms cause strong positive disturbances in F-region of ionosphere in night sector. Negative disturbances are much less and arise, mainly, at night in the middle and low latitudes. During substorms longitudinal extent of main ionospheric trough increases. The substorm beginning in 18 UT, causes negative disturbances in high latitudes except for a southern polar cap. Besides there is "stratification" of the main ionospheric trough. As a result in southern hemisphere the additional high-latitude trough which is absent in quiet conditions is formed. "Stratification" of the main ionospheric trough occurs in northern hemisphere at 6 hours after the beginning of the substorm. These "stratifications" are consequence non-stationary magnetospheric convection. Distinction between these events consists that "stratification" in a southern hemisphere occurs in active phase of substorm, and in northern hemisphere in recovery phase. During a substorm beginning in 00 UT, foF2 increases in all northern polar cap. Positive disturbances of foF2 in the equatorial anomaly region cause all presented substorms, except for a substorm beginning in 18 UT

  15. Modeling of a Parabolic Trough Solar Field for Acceptance Testing: A Case Study

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, M. J.; Mehos, M. S.; Kearney, D. W.; McMahan, A. C.

    2011-01-01

    As deployment of parabolic trough concentrating solar power (CSP) systems ramps up, the need for reliable and robust performance acceptance test guidelines for the solar field is also amplified. Project owners and/or EPC contractors often require extensive solar field performance testing as part of the plant commissioning process in order to ensure that actual solar field performance satisfies both technical specifications and performance guaranties between the involved parties. Performance test code work is currently underway at the National Renewable Energy Laboratory (NREL) in collaboration with the SolarPACES Task-I activity, and within the ASME PTC-52 committee. One important aspect of acceptance testing is the selection of a robust technology performance model. NREL1 has developed a detailed parabolic trough performance model within the SAM software tool. This model is capable of predicting solar field, sub-system, and component performance. It has further been modified for this work to support calculation at subhourly time steps. This paper presents the methodology and results of a case study comparing actual performance data for a parabolic trough solar field to the predicted results using the modified SAM trough model. Due to data limitations, the methodology is applied to a single collector loop, though it applies to larger subfields and entire solar fields. Special consideration is provided for the model formulation, improvements to the model formulation based on comparison with the collected data, and uncertainty associated with the measured data. Additionally, this paper identifies modeling considerations that are of particular importance in the solar field acceptance testing process and uses the model to provide preliminary recommendations regarding acceptable steady-state testing conditions at the single-loop level.

  16. Structural limitations of learning in a crowd: communication vulnerability and information diffusion in MOOCs

    Science.gov (United States)

    Gillani, Nabeel; Yasseri, Taha; Eynon, Rebecca; Hjorth, Isis

    2014-09-01

    Massive Open Online Courses (MOOCs) bring together a global crowd of thousands of learners for several weeks or months. In theory, the openness and scale of MOOCs can promote iterative dialogue that facilitates group cognition and knowledge construction. Using data from two successive instances of a popular business strategy MOOC, we filter observed communication patterns to arrive at the ``significant'' interaction networks between learners and use complex network analysis to explore the vulnerability and information diffusion potential of the discussion forums. We find that different discussion topics and pedagogical practices promote varying levels of 1) ``significant'' peer-to-peer engagement, 2) participant inclusiveness in dialogue, and ultimately, 3) modularity, which impacts information diffusion to prevent a truly ``global'' exchange of knowledge and learning. These results indicate the structural limitations of large-scale crowd-based learning and highlight the different ways that learners in MOOCs leverage, and learn within, social contexts. We conclude by exploring how these insights may inspire new developments in online education.

  17. Predicting protein complexes using a supervised learning method combined with local structural information.

    Science.gov (United States)

    Dong, Yadong; Sun, Yongqi; Qin, Chao

    2018-01-01

    The existing protein complex detection methods can be broadly divided into two categories: unsupervised and supervised learning methods. Most of the unsupervised learning methods assume that protein complexes are in dense regions of protein-protein interaction (PPI) networks even though many true complexes are not dense subgraphs. Supervised learning methods utilize the informative properties of known complexes; they often extract features from existing complexes and then use the features to train a classification model. The trained model is used to guide the search process for new complexes. However, insufficient extracted features, noise in the PPI data and the incompleteness of complex data make the classification model imprecise. Consequently, the classification model is not sufficient for guiding the detection of complexes. Therefore, we propose a new robust score function that combines the classification model with local structural information. Based on the score function, we provide a search method that works both forwards and backwards. The results from experiments on six benchmark PPI datasets and three protein complex datasets show that our approach can achieve better performance compared with the state-of-the-art supervised, semi-supervised and unsupervised methods for protein complex detection, occasionally significantly outperforming such methods.

  18. Deep learning-based subdivision approach for large scale macromolecules structure recovery from electron cryo tomograms.

    Science.gov (United States)

    Xu, Min; Chai, Xiaoqi; Muthakana, Hariank; Liang, Xiaodan; Yang, Ge; Zeev-Ben-Mordehai, Tzviya; Xing, Eric P

    2017-07-15

    Cellular Electron CryoTomography (CECT) enables 3D visualization of cellular organization at near-native state and in sub-molecular resolution, making it a powerful tool for analyzing structures of macromolecular complexes and their spatial organizations inside single cells. However, high degree of structural complexity together with practical imaging limitations makes the systematic de novo discovery of structures within cells challenging. It would likely require averaging and classifying millions of subtomograms potentially containing hundreds of highly heterogeneous structural classes. Although it is no longer difficult to acquire CECT data containing such amount of subtomograms due to advances in data acquisition automation, existing computational approaches have very limited scalability or discrimination ability, making them incapable of processing such amount of data. To complement existing approaches, in this article we propose a new approach for subdividing subtomograms into smaller but relatively homogeneous subsets. The structures in these subsets can then be separately recovered using existing computation intensive methods. Our approach is based on supervised structural feature extraction using deep learning, in combination with unsupervised clustering and reference-free classification. Our experiments show that, compared with existing unsupervised rotation invariant feature and pose-normalization based approaches, our new approach achieves significant improvements in both discrimination ability and scalability. More importantly, our new approach is able to discover new structural classes and recover structures that do not exist in training data. Source code freely available at http://www.cs.cmu.edu/∼mxu1/software . mxu1@cs.cmu.edu. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

  19. A new desalination system using a combination of heat pipe, evacuated tube and parabolic trough collector

    International Nuclear Information System (INIS)

    Jafari Mosleh, H.; Jahangiri Mamouri, S.; Shafii, M.B.; Hakim Sima, A.

    2015-01-01

    Highlights: • A new desalination uses a combination of heat pipe and parabolic trough collector. • A twin-glass evacuated tube is used to decrease the thermal losses from heat pipe. • Adding oil into the space between heat pipe and tube collector enhances the yield. • The yield and efficiency reach up to 0.933 kg/(m 2 h) and 65.2%, respectively. - Abstract: The solar collectors have been commonly used in desalination systems. Recent investigations show that the use of a linear parabolic trough collector in solar stills can improve the efficiency of a desalination system. In this work, a combination of a heat pipe and a twin-glass evacuated tube collector is utilized with a parabolic trough collector. Results show that the rate of production and efficiency can reach to 0.27 kg/(m 2 h) and 22.1% when aluminum conducting foils are used in the space between the heat pipe and the twin-glass evacuated tube collector to transfer heat from the tube collector to the heat pipe. When oil is used as a medium for the transfer of heat, filling the space between heat pipe and twin-glass evacuated tube collector, the production and efficiency can increase to 0.933 kg/(m 2 h) and 65.2%, respectively

  20. Geological records of marine environmental changes in the southern Okinawa Trough

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Indexes of sediment grain size, sedimentation rates, geochemical composition, heavy minerals, benthic foraminiferal fauna, indicator species of the Kuroshio Current, paleo-SST and carbonate dissolution of core E017 conformably suggest a great marine environmental change occurring at about 10.1-9.2 cal. kaBP in the southern Okinawa Trough, which may correspond to the strengthening of the Kuroshio Warm Current and re-entering the Okinawa Trough through the sea area off northeast Taiwan. The invasion of Kuroshio current has experienced a process of gradual strengthening and then weakening, and its intensity became more fluctuation during the last 5000 years. Compared to the transition of sediment grain size, geochemical composition and heavy minerals, the foraminiferal faunas show a 900-year lag, which may indicate that the invasion of Kuroshio Current and the consequent sea surface and deep-water environmental changes is a gradual process, and fauna has an obvious lag compared to environment altering. The carbonate dissolution of the Okinawa Trough has had an apparent strengthening since 9.2 cal. kaBP, and reached a maximum in the late 3000 years, which may be caused by the deep-water environmental changes due to the invasion of Kuroshio Current.

  1. Elemental geochemical records of seafloor hydrothermal activities in the sediments from the Okinawa Trough

    Institute of Scientific and Technical Information of China (English)

    ZHAI Shikui; YU Zenghui; DU Tongjun

    2007-01-01

    The major and minor element contents in the sediment core H9 from the hydrothermal fields of the Okinawa Trough show a sharp change at the depth of 80 cm. The elements enriched in the upper 80 cm core are those enriched in the hydrothermal deposits and in the surface sediments recovered from the hydrothermal fields in the trough, which indicates the input of hydrothermal materials. Comparing with other hydrothermal sediments from Mid-ocean Ridges or the Lau Basin, the degree of the enrichment of elements iron, copper, cobalt, and nickel is relatively low. However, the enrichment of elements manganese, lead, arsenic, antimony and mercury is remarkable. The average contents of these elements in the upper 80 cm core sediments are three to six times those in the lower section, and 3 ~ 12 times those in the surface sediments which are not influenced by hydrothermal activities. Hydrothermal activities have contributed significant manganese, lead, arsenic, antimony and mercury to the sediments, and these elements are distinct indicators for the hydrothermal activity in the Okinawa Trough. The significant enrichment of these elements in Core H9 upward from the depth 80 cm indicates the start or the significant enhancing of the hydrothermal activity in this area at about 5 740 aB. P. The average accumulation rate of manganese during this period is about 40 461 μg/( cm2 · ka), which is similar to the hydrothermal sediments in the Lau Basin or the East Pacific Rise.

  2. Mercury Anomaly in the Okinawa Trough Sediments—An Indicator of Modern Seafloor Hydrothermal Activity

    Institute of Scientific and Technical Information of China (English)

    赵一阳; 鄢明才

    1995-01-01

    The Okinawa Trough is located between the shelf-sea area of the East China Sea and the deep-sea area of western Pacific Ocean.More than 60 chemical elements in the sediments from the shelf area of the East China Sea,the Okinawa Trough and western Pacific Ocean were determined by advanced techniques including neutron acti-vation analysis,X-ray fluorescence spectrometry,atomic fluorescence spectrometry and atomic absorption spectrometry.Quantitative comparisons of the element abundances of the sediments were made in terms of the enrichment coefficients(K) of the elements.K>1.5 indicates enrichment (K=1.5-2, weak enrichment;K=2-4,strong enrichment) and K>4,anomalous enrichment.The results show that the Okinawa Trough sediments are characterized by Hg anomaly and the enrichment of such elements as Au,Ag,Se,Te,Sb,Cd,Mn,Mo,etc.Detailed studies show that the excess Hg comes from hydrothermal solutions rather than from the continent,sea water ,marine organisms,cosmic dust or vol-canic rocks.Attributed to modern hydrothermal activities on the sea floor ,Hg anomaly can be used as a geochemical indicator of modern seafloor hydrothermal activity.

  3. Parabolic trough solar concentrators: a technology which can contribute towards pakistan's energy future

    International Nuclear Information System (INIS)

    Masood, R.

    2013-01-01

    The utilization of solar thermal energy has got prime importance in Pakistan due to the current energy scarcity and escalating cost scenario in the country. Parabolic Trough Solar Concentrator is one of the most reliable technologies for utilization of solar thermal energy. In solar thermal power generation, Parabolic Trough Solar Concentrators are most successful as almost 96 percent of total solar thermal power is generated across the world by utilizing this technology. Its high reliability, operational compatibility, comparative low cost and high efficiency adds to its high value among other resources. Fortunately, Pakistan lies in the high Solar Insolation Zone; thus, a huge potential exists to benefit from this technology. This technology may cater to the Pakistan's seasonal increased electricity demand. Apart from electric power generation, this technology may also have cost-effective solutions for Pakistan's other industries, like steam generation, preheating of boiler make-up water, air-conditioning, and hot water production for food, textile, dairy and leather industries. However, economic justification of such projects would be possible only on accomplishing an indigenous technology base. Globally, this is a proven technology, but in Pakistan there is hardly any development in this field. In this study, an effort has been made by designing and fabricating an experimental Parabolic Trough Solar Water Heater by utilizing locally available materials and manufacturing capabilities. On achieving encouraging results, a solar boiler (steam generator) is proposed to be manufactured locally. (author)

  4. Numerical simulation of solar parabolic trough collector performance in the Algeria Saharan region

    International Nuclear Information System (INIS)

    Marif, Yacine; Benmoussa, Hocine; Bouguettaia, Hamza; Belhadj, Mohamed M.; Zerrouki, Moussa

    2014-01-01

    Highlights: • The parabolic trough collector performance is examined. • The finite difference method is proposed and validated. • Two fluids are considered water and TherminolVP-1™. - Abstract: In order to determine the optical and thermal performance of a solar parabolic trough collector under the climate conditions of Algerian Sahara, a computer program based on one dimensional implicit finite difference method with energy balance approach has been developed. The absorber pipe, glass envelope and fluid were divided into several segments and the partial derivation in the differential equations was replaced by the backward finite difference terms in each segment. Two fluids were considered, liquid water and TherminolVP-1™ synthetic oil. Furthermore, the intensity of the direct solar radiation was estimated by monthly average values of the atmospheric Linke turbidity factor for different tracking systems. According to the simulation findings, the one axis polar East–West and horizontal East–West tracking systems were most desirable for a parabolic trough collector throughout the whole year. In addition, it is found that the thermal efficiency was about 69.73–72.24%, which decreases with the high synthetic oil fluid temperatures and increases in the lower water temperature by 2%

  5. Detailed Physical Trough Model for NREL's Solar Advisor Model: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, M. J.; Blair, N.; Dobos, A.

    2010-10-01

    Solar Advisor Model (SAM) is a free software package made available by the National Renewable Energy Laboratory (NREL), Sandia National Laboratory, and the US Department of Energy. SAM contains hourly system performance and economic models for concentrating solar power (CSP) systems, photovoltaic, solar hot-water, and generic fuel-use technologies. Versions of SAM prior to 2010 included only the parabolic trough model based on Excelergy. This model uses top-level empirical performance curves to characterize plant behavior, and thus is limited in predictive capability for new technologies or component configurations. To address this and other functionality challenges, a new trough model; derived from physical first principles was commissioned to supplement the Excelergy-based empirical model. This new 'physical model' approaches the task of characterizing the performance of the whole parabolic trough plant by replacing empirical curve-fit relationships with more detailed calculations where practical. The resulting model matches the annual performance of the SAM empirical model (which has been previously verified with plant data) while maintaining run-times compatible with parametric analysis, adding additional flexibility in modeled system configurations, and providing more detailed performance calculations in the solar field, power block, piping, and storage subsystems.

  6. MONTI as continent catheterized stoma using serosal-lined trough "Ghoneim Abolenin" technique in ileocystoplasty

    Directory of Open Access Journals (Sweden)

    Mohammed T Sammour

    2011-01-01

    Full Text Available It is a great challenge to select and perform continent mechanism in a stoma for urinary reservoir. A new technique by combining MONTI ileal conduit with the serosal lined trough in order to achieve continent catheterizable stoma to the umbilicus as a part of augmentation ileocystoplasty. We applied serosal-lined trough as a continent mechanism with MONTI ileal tube in 12 years smart girl underwent ileocystoplasty for neuropathic bladder due to meylomeningocele in whom continence failed to be achieved by using Mitrofanoff with submucosal tunnel of the bladder as continent mechanism before, also the previous operation included left to right transuretero-ureterostomy, ureterocystoplasty and reimplantation of the right ureter. The patient became completely continent; she was able to do self-catheterization easily through the umbilical stoma using 16-French catheter and was able to wash the mucous easily. The capacity of the augmented bladder was 300ccs. She became independent from her mother and stopped using diapers, anticholinergic and antibiotics. Combining MONTI conduit with serosal-lined extramural valve trough (The Ghoneim technique is an effective continent technique and gives wider channel for catheterization and washing out the mucous.

  7. Practicality and Performance of Daylight Trough in The Tropics: A Case Study

    Directory of Open Access Journals (Sweden)

    Gene-Harn Lim

    2016-01-01

    Full Text Available The field of office daylighting is vital for both energy efficiency practice and occupants’ visual comfort. With the emergence of green building in Malaysia, building designers are exploring avenues for energy efficiency design; one common strategy is daylighting. The majority literature reviews on daylighting are skewed towards temperate or developed countries, where sky luminous condition is different from that of the Tropics. Conventional daylighting system designs redirect daylight from the envelope or atrium openings, such as light shelves. Presumed to be the pioneer daylight trough in the Tropics, this paper presents the simulated and in-situ lighting level measurements prior to occupancy. This case study presents an as-built daylight trough design which is able to daylight the office space as deep as 6 meters sufficiently. It achieves a lighting power density 1.90W/m2 and saves 39.2% of lighting energy over conventional office lighting energy. Discussed further is the practicality of working with such a system, including cost implication, return on investment and contractual challenges in reaching a consensus on the design. The results reinforce that the effectiveness of daylighting design is very dependable on the sun path and obstacles surrounding the office tower. The RADIANCE simulation correlates well to field measurement results. Further investigation into the light trough, its lighting energy savings, users’ interaction, visual comfort, and glare is still ongoing.

  8. The Effect of Changing Focal Trough in a Panoramic Device on the Accuracy of Distance Measurements

    Directory of Open Access Journals (Sweden)

    Mehrdad Abdinian

    2018-01-01

    Full Text Available >Introduction: Magnification and distortion are the most important limitations of panoramic radiography. The aim of this study was to determine the effects of changing focal trough option of Planmeca SCARA 3 on the accuracy of linear distance measurements.Materials and Methods: In this in-vitro study, 28 pieces of gutta-percha were attached to the assumptive place of each lost root of an adult dry skull with average size and normal shape. The actual measurements were obtained by a digital caliper. The panoramic images of the skull were taken in six different sizes and shapes of focal trough. This procedure was repeated ten times with new gutta-percha. Paired t-test was used to compare the values of different actual and radiographic images of gutta-percha dimensions.Results: The mean difference [standard deviation (SD] between actual measurement and panoramic radiography in the different groups was from 0.37 (1.1 to 0.58 (2.87 mm. The mean (SD difference of linear measurements between real and radiographic images was 0.52 (0.43 mm in average size, V-shaped group, which was statistically and clinically significant (P = 0.00.Conclusion: Changing the focal trough option of Planmeca SCARA 3 has minimal effects on the accuracy of linear measurements in panoramic radiographs.

  9. The cost of integration of parabolic trough CSP plants in isolated Mediterranean power systems

    International Nuclear Information System (INIS)

    Poullikkas, Andreas; Hadjipaschalis, Ioannis; Kourtis, George

    2010-01-01

    In this work, a technical and economic analysis concerning the integration of parabolic trough concentrated solar power (CSP) technologies, with or without thermal storage capability, in an existing typical small isolated Mediterranean power generation system, in the absence of a feed-in tariff scheme, is carried out. In addition to the business as usual (BAU) scenario, five more scenarios are examined in the analysis in order to assess the electricity unit cost with the penetration of parabolic trough CSP plants of 50 MWe or 100 MWe, with or without thermal storage capability. Based on the input data and assumptions made, the simulations indicated that the scenario with the utilization of a single parabolic trough CSP plant (either 50 MWe or 100 MWe and with or without thermal storage capability) in combination with BAU will effect an insignificant change in the electricity unit cost of the generation system compared to the BAU scenario. In addition, a sensitivity analysis on natural gas price, showed that increasing fuel prices and the existence of thermal storage capability in the CSP plant make this scenario marginally more economically attractive compared to the BAU scenario. (author)

  10. Discriminative Structured Dictionary Learning on Grassmann Manifolds and Its Application on Image Restoration.

    Science.gov (United States)

    Pan, Han; Jing, Zhongliang; Qiao, Lingfeng; Li, Minzhe

    2017-09-25

    Image restoration is a difficult and challenging problem in various imaging applications. However, despite of the benefits of a single overcomplete dictionary, there are still several challenges for capturing the geometric structure of image of interest. To more accurately represent the local structures of the underlying signals, we propose a new problem formulation for sparse representation with block-orthogonal constraint. There are three contributions. First, a framework for discriminative structured dictionary learning is proposed, which leads to a smooth manifold structure and quotient search spaces. Second, an alternating minimization scheme is proposed after taking both the cost function and the constraints into account. This is achieved by iteratively alternating between updating the block structure of the dictionary defined on Grassmann manifold and sparsifying the dictionary atoms automatically. Third, Riemannian conjugate gradient is considered to track local subspaces efficiently with a convergence guarantee. Extensive experiments on various datasets demonstrate that the proposed method outperforms the state-of-the-art methods on the removal of mixed Gaussian-impulse noise.

  11. DEEP LEARNING AND IMAGE PROCESSING FOR AUTOMATED CRACK DETECTION AND DEFECT MEASUREMENT IN UNDERGROUND STRUCTURES

    Directory of Open Access Journals (Sweden)

    F. Panella

    2018-05-01

    Full Text Available This work presents the combination of Deep-Learning (DL and image processing to produce an automated cracks recognition and defect measurement tool for civil structures. The authors focus on tunnel civil structures and survey and have developed an end to end tool for asset management of underground structures. In order to maintain the serviceability of tunnels, regular inspection is needed to assess their structural status. The traditional method of carrying out the survey is the visual inspection: simple, but slow and relatively expensive and the quality of the output depends on the ability and experience of the engineer as well as on the total workload (stress and tiredness may influence the ability to observe and record information. As a result of these issues, in the last decade there is the desire to automate the monitoring using new methods of inspection. The present paper has the goal of combining DL with traditional image processing to create a tool able to detect, locate and measure the structural defect.

  12. Recognizing molecular patterns by machine learning: An agnostic structural definition of the hydrogen bond

    International Nuclear Information System (INIS)

    Gasparotto, Piero; Ceriotti, Michele

    2014-01-01

    The concept of chemical bonding can ultimately be seen as a rationalization of the recurring structural patterns observed in molecules and solids. Chemical intuition is nothing but the ability to recognize and predict such patterns, and how they transform into one another. Here, we discuss how to use a computer to identify atomic patterns automatically, so as to provide an algorithmic definition of a bond based solely on structural information. We concentrate in particular on hydrogen bonding – a central concept to our understanding of the physical chemistry of water, biological systems, and many technologically important materials. Since the hydrogen bond is a somewhat fuzzy entity that covers a broad range of energies and distances, many different criteria have been proposed and used over the years, based either on sophisticate electronic structure calculations followed by an energy decomposition analysis, or on somewhat arbitrary choices of a range of structural parameters that is deemed to correspond to a hydrogen-bonded configuration. We introduce here a definition that is univocal, unbiased, and adaptive, based on our machine-learning analysis of an atomistic simulation. The strategy we propose could be easily adapted to similar scenarios, where one has to recognize or classify structural patterns in a material or chemical compound

  13. Recognizing molecular patterns by machine learning: An agnostic structural definition of the hydrogen bond

    Energy Technology Data Exchange (ETDEWEB)

    Gasparotto, Piero; Ceriotti, Michele, E-mail: michele.ceriotti@epfl.ch [Laboratory of Computational Science and Modeling, and National Center for Computational Design and Discovery of Novel Materials MARVEL, IMX, École Polytechnique Fédérale de Lausanne, 1015 Lausanne (Switzerland)

    2014-11-07

    The concept of chemical bonding can ultimately be seen as a rationalization of the recurring structural patterns observed in molecules and solids. Chemical intuition is nothing but the ability to recognize and predict such patterns, and how they transform into one another. Here, we discuss how to use a computer to identify atomic patterns automatically, so as to provide an algorithmic definition of a bond based solely on structural information. We concentrate in particular on hydrogen bonding – a central concept to our understanding of the physical chemistry of water, biological systems, and many technologically important materials. Since the hydrogen bond is a somewhat fuzzy entity that covers a broad range of energies and distances, many different criteria have been proposed and used over the years, based either on sophisticate electronic structure calculations followed by an energy decomposition analysis, or on somewhat arbitrary choices of a range of structural parameters that is deemed to correspond to a hydrogen-bonded configuration. We introduce here a definition that is univocal, unbiased, and adaptive, based on our machine-learning analysis of an atomistic simulation. The strategy we propose could be easily adapted to similar scenarios, where one has to recognize or classify structural patterns in a material or chemical compound.

  14. Recognizing molecular patterns by machine learning: An agnostic structural definition of the hydrogen bond

    Science.gov (United States)

    Gasparotto, Piero; Ceriotti, Michele

    2014-11-01

    The concept of chemical bonding can ultimately be seen as a rationalization of the recurring structural patterns observed in molecules and solids. Chemical intuition is nothing but the ability to recognize and predict such patterns, and how they transform into one another. Here, we discuss how to use a computer to identify atomic patterns automatically, so as to provide an algorithmic definition of a bond based solely on structural information. We concentrate in particular on hydrogen bonding - a central concept to our understanding of the physical chemistry of water, biological systems, and many technologically important materials. Since the hydrogen bond is a somewhat fuzzy entity that covers a broad range of energies and distances, many different criteria have been proposed and used over the years, based either on sophisticate electronic structure calculations followed by an energy decomposition analysis, or on somewhat arbitrary choices of a range of structural parameters that is deemed to correspond to a hydrogen-bonded configuration. We introduce here a definition that is univocal, unbiased, and adaptive, based on our machine-learning analysis of an atomistic simulation. The strategy we propose could be easily adapted to similar scenarios, where one has to recognize or classify structural patterns in a material or chemical compound.

  15. Document page structure learning for fixed-layout e-books using conditional random fields

    Science.gov (United States)

    Tao, Xin; Tang, Zhi; Xu, Canhui

    2013-12-01

    In this paper, a model is proposed to learn logical structure of fixed-layout document pages by combining support vector machine (SVM) and conditional random fields (CRF). Features related to each logical label and their dependencies are extracted from various original Portable Document Format (PDF) attributes. Both local evidence and contextual dependencies are integrated in the proposed model so as to achieve better logical labeling performance. With the merits of SVM as local discriminative classifier and CRF modeling contextual correlations of adjacent fragments, it is capable of resolving the ambiguities of semantic labels. The experimental results show that CRF based models with both tree and chain graph structures outperform the SVM model with an increase of macro-averaged F1 by about 10%.

  16. Fast Gaussian kernel learning for classification tasks based on specially structured global optimization.

    Science.gov (United States)

    Zhong, Shangping; Chen, Tianshun; He, Fengying; Niu, Yuzhen

    2014-09-01

    For a practical pattern classification task solved by kernel methods, the computing time is mainly spent on kernel learning (or training). However, the current kernel learning approaches are based on local optimization techniques, and hard to have good time performances, especially for large datasets. Thus the existing algorithms cannot be easily extended to large-scale tasks. In this paper, we present a fast Gaussian kernel learning method by solving a specially structured global optimization (SSGO) problem. We optimize the Gaussian kernel function by using the formulated kernel target alignment criterion, which is a difference of increasing (d.i.) functions. Through using a power-transformation based convexification method, the objective criterion can be represented as a difference of convex (d.c.) functions with a fixed power-transformation parameter. And the objective programming problem can then be converted to a SSGO problem: globally minimizing a concave function over a convex set. The SSGO problem is classical and has good solvability. Thus, to find the global optimal solution efficiently, we can adopt the improved Hoffman's outer approximation method, which need not repeat the searching procedure with different starting points to locate the best local minimum. Also, the proposed method can be proven to converge to the global solution for any classification task. We evaluate the proposed method on twenty benchmark datasets, and compare it with four other Gaussian kernel learning methods. Experimental results show that the proposed method stably achieves both good time-efficiency performance and good classification performance. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. A possible structural correlate of learning performance on a colour discrimination task in the brain of the bumblebee

    Science.gov (United States)

    Li, Li; MaBouDi, HaDi; Egertová, Michaela; Elphick, Maurice R.

    2017-01-01

    Synaptic plasticity is considered to be a basis for learning and memory. However, the relationship between synaptic arrangements and individual differences in learning and memory is poorly understood. Here, we explored how the density of microglomeruli (synaptic complexes) within specific regions of the bumblebee (Bombus terrestris) brain relates to both visual learning and inter-individual differences in learning and memory performance on a visual discrimination task. Using whole-brain immunolabelling, we measured the density of microglomeruli in the collar region (visual association areas) of the mushroom bodies of the bumblebee brain. We found that bumblebees which made fewer errors during training in a visual discrimination task had higher microglomerular density. Similarly, bumblebees that had better retention of the learned colour-reward associations two days after training had higher microglomerular density. Further experiments indicated experience-dependent changes in neural circuitry: learning a colour-reward contingency with 10 colours (but not two colours) does result, and exposure to many different colours may result, in changes to microglomerular density in the collar region of the mushroom bodies. These results reveal the varying roles that visual experience, visual learning and foraging activity have on neural structure. Although our study does not provide a causal link between microglomerular density and performance, the observed positive correlations provide new insights for future studies into how neural structure may relate to inter-individual differences in learning and memory. PMID:28978727

  18. A possible structural correlate of learning performance on a colour discrimination task in the brain of the bumblebee.

    Science.gov (United States)

    Li, Li; MaBouDi, HaDi; Egertová, Michaela; Elphick, Maurice R; Chittka, Lars; Perry, Clint J

    2017-10-11

    Synaptic plasticity is considered to be a basis for learning and memory. However, the relationship between synaptic arrangements and individual differences in learning and memory is poorly understood. Here, we explored how the density of microglomeruli (synaptic complexes) within specific regions of the bumblebee ( Bombus terrestris ) brain relates to both visual learning and inter-individual differences in learning and memory performance on a visual discrimination task. Using whole-brain immunolabelling, we measured the density of microglomeruli in the collar region (visual association areas) of the mushroom bodies of the bumblebee brain. We found that bumblebees which made fewer errors during training in a visual discrimination task had higher microglomerular density. Similarly, bumblebees that had better retention of the learned colour-reward associations two days after training had higher microglomerular density. Further experiments indicated experience-dependent changes in neural circuitry: learning a colour-reward contingency with 10 colours (but not two colours) does result, and exposure to many different colours may result, in changes to microglomerular density in the collar region of the mushroom bodies. These results reveal the varying roles that visual experience, visual learning and foraging activity have on neural structure. Although our study does not provide a causal link between microglomerular density and performance, the observed positive correlations provide new insights for future studies into how neural structure may relate to inter-individual differences in learning and memory. © 2017 The Authors.

  19. Learning Motivation and Retention Effects of Pair Programming in Data Structures Courses

    Science.gov (United States)

    Yang, Ya-Fei; Lee, Chien-I; Chang, Chih-Kai

    2016-01-01

    Collaborative learning is an activity in which two or more students learn something together. Many studies have found that collaborative learning improve students' memory retention and motivation to learn. Peer Instruction (PI) is one of the most successful evidence-based collaborative learning methods. This article investigates issues of student…

  20. Does Structured Quizzing with Process Specific Feedback Lead to Learning Gains in an Active Learning Geoscience Classroom?

    Science.gov (United States)

    Palsole, S.; Serpa, L. F.

    2013-12-01

    There is a great realization that efficient teaching in the geosciences has the potential to have far reaching effects in outreach to decision and policy makers (Herbert, 2006; Manduca & Mogk, 2006). This research in turn informs educators that the geosciences by the virtue of their highly integrative nature play an important role in serving as an entry point into STEM disciplines and helping developing a new cadre of geoscientists, scientists and a general population with an understanding of science. Keeping these goals in mind we set to design introductory geoscience courses for non-majors and majors that move away from the traditional lecture models which don't necessarily contribute well to knowledge building and retention ((Handelsman et al., 2007; Hake, 1997) to a blended active learning classroom where basic concepts and didactic information is acquired online via webquests, lecturettes and virtual field trips and the face to face portions of the class are focused on problem solving exercises. The traditional way to ensure that students are prepared for the in-class activity is to have the students take a quiz online to demonstrate basic competency. In the process of redesign, we decided to leverage the technology to build quizzes that are highly structured and map to a process (formation of divergent boundaries for example) or sets of earth processes that we needed the students to know before in-class activities. The quizzes can be taken multiple times and provide process specific feedback, thus serving as a heuristic to the students to ensure they have acquired the necessary competency. The heuristic quizzes were developed and deployed over a year with the student data driving the redesign process to ensure synchronicity. Preliminary data analysis indicates a positive correlation between higher student scores on in-class application exercises and time spent on the process quizzes. An assessment of learning gains also indicate a higher degree of self

  1. Automatic feature learning using multichannel ROI based on deep structured algorithms for computerized lung cancer diagnosis.

    Science.gov (United States)

    Sun, Wenqing; Zheng, Bin; Qian, Wei

    2017-10-01

    This study aimed to analyze the ability of extracting automatically generated features using deep structured algorithms in lung nodule CT image diagnosis, and compare its performance with traditional computer aided diagnosis (CADx) systems using hand-crafted features. All of the 1018 cases were acquired from Lung Image Database Consortium (LIDC) public lung cancer database. The nodules were segmented according to four radiologists' markings, and 13,668 samples were generated by rotating every slice of nodule images. Three multichannel ROI based deep structured algorithms were designed and implemented in this study: convolutional neural network (CNN), deep belief network (DBN), and stacked denoising autoencoder (SDAE). For the comparison purpose, we also implemented a CADx system using hand-crafted features including density features, texture features and morphological features. The performance of every scheme was evaluated by using a 10-fold cross-validation method and an assessment index of the area under the receiver operating characteristic curve (AUC). The observed highest area under the curve (AUC) was 0.899±0.018 achieved by CNN, which was significantly higher than traditional CADx with the AUC=0.848±0.026. The results from DBN was also slightly higher than CADx, while SDAE was slightly lower. By visualizing the automatic generated features, we found some meaningful detectors like curvy stroke detectors from deep structured schemes. The study results showed the deep structured algorithms with automatically generated features can achieve desirable performance in lung nodule diagnosis. With well-tuned parameters and large enough dataset, the deep learning algorithms can have better performance than current popular CADx. We believe the deep learning algorithms with similar data preprocessing procedure can be used in other medical image analysis areas as well. Copyright © 2017. Published by Elsevier Ltd.

  2. Building Collaborative Structures for Teachers' Autonomy and Self-Efficacy: The Mediating Role of Participative Management and Learning Culture

    Science.gov (United States)

    Lu, Jiafang; Jiang, Xinhui; Yu, Huen; Li, Dongyu

    2015-01-01

    This study focused on the collaborative structure-building behavior of school principals and examined how such behavior affects teacher empowerment. More important, it tested the mediating effects of participative management and learning culture. By collecting nested data from 104 schools in Hong Kong and adopting multilevel structural equation…

  3. OBJECTIVE STRUCTURED PRACTICAL EXAMINATION AS A LEARNING AND EVALUATION TOOL FOR BIOCHEMISTRY- FIRST EXPERIENCE

    Directory of Open Access Journals (Sweden)

    Vidyabati Devi Rajkumari

    2017-06-01

    Full Text Available BACKGROUND Assessment plays an important role in helping learners identify their own learning needs. The objective structured practical examination assesses practical skills in an objective and structured manner with direct observation of the students’ performance during planned clinical test. The aim of the study is to evaluate OSPE as a method of learning and formative assessment to the practical skill and to explore faculty perception of OSPE as a learning and assessment tool. MATERIALS AND METHODS A total of 98 students of first year MBBS student admitted for 2015-16 batch of Jawaharlal Nehru Institute of Medical Sciences, Imphal, were the subjects for the study. Day one- Group A (1-50 students were evaluated by OSPE method of assessment. Day two- Group B (51-98 were evaluated by standard practical examination. To avoid examiners Bias on Day 3- Group C (51- 98 who were evaluated by SPE were evaluated by OSPE with minor variations. Group A underwent OSPE. Questionnaire was given to students after the assessment on the fourth day to get the feedback. RESULTS Independent sample t-test comparing mean percent scores of OSPE and SPE between the groups. There is no statistically significant difference in the mean percent scores for OSPE and SPE among the two groups. Paired sample t-test comparing mean percent scores of OSPE and SPE of group B students. The mean percentage score for OSPE is higher than the percentage scores obtained in SPE among the group B students, but the difference was not found to be statistically significant. The feedback from the students showed that more than 80% agreed that OSPE was less stressful to perform that it was a more objective assessment. CONCLUSION In conclusion, OSPE has several distinct advantages. From our first experience, we found that OSPE was more objective, measured practical skills better and eliminated examiner bias.

  4. Petrologic perspectives on tectonic evolution of a nascent basin (Okinawa Trough) behind Ryukyu Arc:A review

    Institute of Scientific and Technical Information of China (English)

    YAN Quanshu; SHI Xuefa

    2014-01-01

    Okinawa Trough is a back-arc, initial marginal sea basin, located behind the Ryukyu Arc-Trench System. The formation and evolution of the Okinawa Trough is intimately related to the subduction process of the Philippine Sea Plate beneath the Eurasian Plate since the late Miocene. The tectonic evolution of the trough is similar to other active back-arcs, such as the Mariana Trough and southern Lau Basin, all of which are experiencing the initial rifting and subsequent spreading process. This study reviews all petrologic and geochemical data of mafic volcanic lavas from the Okinawa Trough, Ryukyu Arc, and Philippine Sea Plate, combined with geophysical data to indicate the relationship between the subduction sources (input) and arc or back-arc magmas (output) in the Philippine Sea Plate-Ryukyu Arc-Okinawa Trough system (PROS). The results obtained showed that several components were variably involved in the petrogenesis of the Oki-nawa Trough lavas:sub-continental lithospheric mantle underlying the Eurasian Plate, Indian mid-oceanic ridge basalt (MORB)-type mantle, and Pacific MORB-type mantle. The addition of shallow aqueous fluids and deep hydrous melts from subducted components with the characteristics of Indian MORB-type mantle into the mantle source of lavas variably modifies the primitive mantle wedge beneath the Ryukyu and sub-continental lithospheric mantle (SCLM) beneath the Okinawa Trough. In the northeastern end of the trough and arc, instead of Indian MORB-type mantle, Pacific MORB-type mantle dominates the magma source. Along the strike of the Ryukyu Arc and Okinawa Trough, the systematic variations in trace element ratios and isotopic compositions reflect the first-order effect of variable subduction input on the magma source. In general, petrologic data, combined with geophysical data, imply that the Okinawa Trough is experiencing the“seafloor spreading”process in the southwest segment,“rift propagation”process in the middle seg-ment, and

  5. The Relationship Between Vancomycin Trough Concentrations and AUC/MIC Ratios in Pediatric Patients: A Qualitative Systematic Review.

    Science.gov (United States)

    Tkachuk, Stacey; Collins, Kyle; Ensom, Mary H H

    2018-04-01

    In adults, the area under the concentration-time curve (AUC) divided by the minimum inhibitory concentration (MIC) is associated with better clinical and bacteriological response to vancomycin in patients with methicillin-resistant Staphylococcus aureus who achieve target AUC/MIC ≥ 400. This target is often extrapolated to pediatric patients despite the lack of similar evidence. The impracticalities of calculating the AUC in practice means vancomycin trough concentrations are used to predict the AUC/MIC. This review aimed to determine the relationship between vancomycin trough concentrations and AUC/MIC in pediatric patients. We searched the MEDLINE and Embase databases, the Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials using the medical subject heading (MeSH) terms vancomycin and AUC and pediatric* or paediatric*. Articles were included if they were published in English and reported a relationship between vancomycin trough concentrations and AUC/MIC. Of 122 articles retrieved, 11 met the inclusion criteria. One trial reported a relationship between vancomycin trough concentrations, AUC/MIC, and clinical outcomes but was likely underpowered. Five studies found troughs 6-10 mg/l were sufficient to attain an AUC/MIC > 400 in most general hospitalized pediatric patients. One study in patients undergoing cardiothoracic surgery found a trough of 18.4 mg/l achieved an AUC/MIC > 400. Two oncology studies reported troughs ≥ 15 mg/l likely attained an AUC/MIC ≥ 400. In critical care patients: one study found a trough of 9 mg/l did not attain the AUC/MIC target; another found 7 mg/l corresponded to an AUC/MIC of 400. Potential vancomycin targets varied based on the population studied but, for general hospitalized pediatric patients, troughs of 6-10 mg/l are likely sufficient to achieve AUC/MIC ≥ 400. For MIC ≥ 2 mg/l, higher troughs are likely necessary to achieve an AUC/MIC ≥ 400. More

  6. Lipid Composition of methane-derived Carbonate Crusts and Sediments from Mud Volcanoes in the Sorokin Trough, NE Black Sea

    Science.gov (United States)

    Stadnitskaia, A.; Baas, M.; Hopmans, E.; van Weering, T.; Sinninghe Damsté, J.

    2003-04-01

    We investigated the distributions and d13C values of bacterial and archaeal lipids in four carbonate crusts and hosting sediments collected from three mud volcanoes in the Sorokin Trough during the 11th Training Through Research expedition in 2001. The lipid extract from carbonate crusts contains abundant archaeal and bacterial biomarkers such as pentamethylicosane (PMI), unsaturated PMIs, archaeol, hydroxyarchaeols (sn-2 and sn-3 isomers), diphytanyl glycerol diethers (DGDs). Hosting sediments also contain a diversity of bacterial and archaeal lipids, but their concentrations are significantly lower then those observed in the crusts. The stable isotopic signature of these compounds have established their biosynthesis by consortia of microorganisms performing anaerobic methanotrophy. Quantitatively, the most predominant group of archaeal core membrane lipids in the crusts and in the sediments is the glycerol dialkyl glycerol tetraethers (GDGTs). Besides, two carbonate crusts contained two archaeal core membrane macrocyclic diether lipids which have not been reported previously. These macrocyclic diethers are structurally related to GDGTs with one and two cyclopentane rings. Cyclopentane-bearing GDGTs are well known for different archaeal species thriving in different environments, while a macrocyclic diether was found only in the thermophilic methanogen Methanococcus jannaschi. Therefore, the molecular structure of novel macrocyclic DGDs unites ecologically contrasting archaeal groups. Strongly depleted carbon isotopic values of these diethers indicate that these diethers derived from archaea acting within anaerobic methane-oxidizing consortia in cold-water environments.

  7. Learning Structure of Sensory Inputs with Synaptic Plasticity Leads to Interference

    Directory of Open Access Journals (Sweden)

    Joseph eChrol-Cannon

    2015-08-01

    Full Text Available Synaptic plasticity is often explored as a form of unsupervised adaptationin cortical microcircuits to learn the structure of complex sensoryinputs and thereby improve performance of classification and prediction. The question of whether the specific structure of the input patterns is encoded in the structure of neural networks has been largely neglected. Existing studies that have analyzed input-specific structural adaptation have used simplified, synthetic inputs in contrast to complex and noisy patterns found in real-world sensory data.In this work, input-specific structural changes are analyzed forthree empirically derived models of plasticity applied to three temporal sensory classification tasks that include complex, real-world visual and auditory data. Two forms of spike-timing dependent plasticity (STDP and the Bienenstock-Cooper-Munro (BCM plasticity rule are used to adapt the recurrent network structure during the training process before performance is tested on the pattern recognition tasks.It is shown that synaptic adaptation is highly sensitive to specific classes of input pattern. However, plasticity does not improve the performance on sensory pattern recognition tasks, partly due to synaptic interference between consecutively presented input samples. The changes in synaptic strength produced by one stimulus are reversed by thepresentation of another, thus largely preventing input-specific synaptic changes from being retained in the structure of the network.To solve the problem of interference, we suggest that models of plasticitybe extended to restrict neural activity and synaptic modification to a subset of the neural circuit, which is increasingly found to be the casein experimental neuroscience.

  8. Real-time dynamic analysis for complete loop of direct steam generation solar trough collector

    International Nuclear Information System (INIS)

    Guo, Su; Liu, Deyou; Chu, Yinghao; Chen, Xingying; Shen, Bingbing; Xu, Chang; Zhou, Ling; Wang, Pei

    2016-01-01

    Highlights: • A nonlinear distribution parameter dynamic model has been developed. • Real-time local heat transfer coefficient and friction coefficient are adopted. • The dynamic behavior of the solar trough collector loop are simulated. • High-frequency chattering of outlet fluid flow are analyzed and modeled. • Irradiance disturbance at subcooled water region generates larger influence. - Abstract: Direct steam generation is a potential approach to further reduce the levelized electricity cost of solar trough. Dynamic modeling of the collector loop is essential for operation and control of direct steam generation solar trough. However, the dynamic behavior of fluid based on direct steam generation is complex because of the two-phase flow in the pipeline. In this work, a nonlinear distribution parameter model has been developed to model the dynamic behaviors of direct steam generation parabolic trough collector loops under either full or partial solar irradiance disturbance. Compared with available dynamic model, the proposed model possesses two advantages: (1) real-time local values of heat transfer coefficient and friction resistance coefficient, and (2) considering of the complete loop of collectors, including subcooled water region, two-phase flow region and superheated steam region. The proposed model has shown superior performance, particularly in case of sensitivity study of fluid parameters when the pipe is partially shaded. The proposed model has been validated using experimental data from Solar Thermal Energy Laboratory of University of New South Wales, with an outlet fluid temperature relative error of only 1.91%. The validation results show that: (1) The proposed model successfully outperforms two reference models in predicting the behavior of direct steam generation solar trough. (2) The model theoretically predicts that, during solar irradiance disturbance, the discontinuities of fluid physical property parameters and the moving back and

  9. The Effect of Universal Design for Learning (UDL) Application on E-Learning Acceptance: A Structural Equation Model

    Science.gov (United States)

    Al-Azawei, Ahmed; Parslow, Patrick; Lundqvist, Karsten

    2017-01-01

    Standardising learning content and teaching approaches is not considered to be the best practice in contemporary education. This approach does not differentiate learners based on their individual abilities and preferences. The present research integrates a pedagogical theory "Universal Design for Learning" ("UDL") with an…

  10. A modelling study of the post-sunset formation of plasma temperature troughs in the equatorial topside ionosphere

    International Nuclear Information System (INIS)

    Bailey, G.J.; Moffett, R.J.; Simmons, P.A.; Footitt, R.J.

    1986-01-01

    Results of model calculations are used to study the post-sunset development of plasma temperature troughs along tubes of plasma at equatorial latitudes. The calculations show that for about 90 minutes after sunset the ion field-aligned velocities are directed poleward in both hemispheres even though the meridional neutral air wind blows from the summer hemisphere to the winter hemisphere. After about 90 minutes the ion field-aligned velocities become directed from the summer hemisphere to the winter hemisphere in both hemispheres. As time advances plasma temperature troughs are formed along the tubes of plasma. Initially the plasma temperature troughs increase in depth, but because in the calculations the tubes of plasma are taken to be moving towards the Earth, the plasma temperature troughs then decrease in depth. At sunspot maximum the plasma temperature troughs are deep and narrow in dip latitude; at sunspot minimum they are shallow and wide. It is shown that the ion field-aligned velocities and the depth of the plasma temperature troughs are extremely sensitive to the neutral atomic hydrogen concentration, especially when the topside ionosphere is dominated by O + . Indications are that the MSIS-83 sunspot maximum concentrations of neutral atomic hydrogen in the topside ionosphere at equatorial latitudes are too low by a factor of about 2. The neutral atomic hydrogen concentration determines whether the transequatorial O + flow is a subsonic ''breeze'' or a supersonic ''wind''

  11. Structural geology practice and learning, from the perspective of cognitive science

    Science.gov (United States)

    Shipley, Thomas F.; Tikoff, Basil; Ormand, Carol; Manduca, Cathy

    2013-09-01

    Spatial ability is required by practitioners and students of structural geology and so, considering spatial skills in the context of cognitive science has the potential to improve structural geology teaching and practice. Spatial thinking skills may be organized using three dichotomies, which can be linked to structural geology practice. First, a distinction is made between separating (attending to part of a whole) and combining (linking together aspects of the whole). While everyone has a basic ability to separate and combine, experts attend to differences guided by experiences of rock properties in context. Second, a distinction is made between seeing the relations among multiple objects as separate items or the relations within a single object with multiple parts. Experts can flexibly consider relations among or between objects to optimally reason about different types of spatial problems. Third, a distinction is made between reasoning about stationary and moving objects. Experts recognize static configurations that encode a movement history, and create mental models of the processes that led to the static state. The observations and inferences made by a geologist leading a field trip are compared with the corresponding observations and inferences made by a cognitive psychologist interested in spatial learning. The presented framework provides a vocabulary for discussing spatial skills both within and between the fields of structural geology and cognitive psychology.

  12. Recent developments in learning control and system identification for robots and structures

    Science.gov (United States)

    Phan, M.; Juang, J.-N.; Longman, R. W.

    1990-01-01

    This paper reviews recent results in learning control and learning system identification, with particular emphasis on discrete-time formulation, and their relation to adaptive theory. Related continuous-time results are also discussed. Among the topics presented are proportional, derivative, and integral learning controllers, time-domain formulation of discrete learning algorithms. Newly developed techniques are described including the concept of the repetition domain, and the repetition domain formulation of learning control by linear feedback, model reference learning control, indirect learning control with parameter estimation, as well as related basic concepts, recursive and non-recursive methods for learning identification.

  13. DuSK: A Dual Structure-preserving Kernel for Supervised Tensor Learning with Applications to Neuroimages

    Science.gov (United States)

    He, Lifang; Kong, Xiangnan; Yu, Philip S.; Ragin, Ann B.; Hao, Zhifeng; Yang, Xiaowei

    2015-01-01

    With advances in data collection technologies, tensor data is assuming increasing prominence in many applications and the problem of supervised tensor learning has emerged as a topic of critical significance in the data mining and machine learning community. Conventional methods for supervised tensor learning mainly focus on learning kernels by flattening the tensor into vectors or matrices, however structural information within the tensors will be lost. In this paper, we introduce a new scheme to design structure-preserving kernels for supervised tensor learning. Specifically, we demonstrate how to leverage the naturally available structure within the tensorial representation to encode prior knowledge in the kernel. We proposed a tensor kernel that can preserve tensor structures based upon dual-tensorial mapping. The dual-tensorial mapping function can map each tensor instance in the input space to another tensor in the feature space while preserving the tensorial structure. Theoretically, our approach is an extension of the conventional kernels in the vector space to tensor space. We applied our novel kernel in conjunction with SVM to real-world tensor classification problems including brain fMRI classification for three different diseases (i.e., Alzheimer's disease, ADHD and brain damage by HIV). Extensive empirical studies demonstrate that our proposed approach can effectively boost tensor classification performances, particularly with small sample sizes. PMID:25927014

  14. DuSK: A Dual Structure-preserving Kernel for Supervised Tensor Learning with Applications to Neuroimages.

    Science.gov (United States)

    He, Lifang; Kong, Xiangnan; Yu, Philip S; Ragin, Ann B; Hao, Zhifeng; Yang, Xiaowei

    With advances in data collection technologies, tensor data is assuming increasing prominence in many applications and the problem of supervised tensor learning has emerged as a topic of critical significance in the data mining and machine learning community. Conventional methods for supervised tensor learning mainly focus on learning kernels by flattening the tensor into vectors or matrices, however structural information within the tensors will be lost. In this paper, we introduce a new scheme to design structure-preserving kernels for supervised tensor learning. Specifically, we demonstrate how to leverage the naturally available structure within the tensorial representation to encode prior knowledge in the kernel. We proposed a tensor kernel that can preserve tensor structures based upon dual-tensorial mapping. The dual-tensorial mapping function can map each tensor instance in the input space to another tensor in the feature space while preserving the tensorial structure. Theoretically, our approach is an extension of the conventional kernels in the vector space to tensor space. We applied our novel kernel in conjunction with SVM to real-world tensor classification problems including brain fMRI classification for three different diseases ( i.e ., Alzheimer's disease, ADHD and brain damage by HIV). Extensive empirical studies demonstrate that our proposed approach can effectively boost tensor classification performances, particularly with small sample sizes.

  15. Evaluation of the role of incentive structure on student participation and performance in active learning strategies: A comparison of case-based and team-based learning.

    Science.gov (United States)

    Carrasco, Gonzalo A; Behling, Kathryn C; Lopez, Osvaldo J

    2018-04-01

    Student participation is important for the success of active learning strategies, but participation is often linked to the level of preparation. At our institution, we use two types of active learning activities, a modified case-based learning exercise called active learning groups (ALG) and team-based learning (TBL). These strategies have different assessment and incentive structures for participation. Non-cognitive skills are assessed in ALG using a subjective five-point Likert scale. In TBL, assessment of individual student preparation is based on a multiple choice quiz conducted at the beginning of each session. We studied first-year medical student participation and performance in ALG and TBL as well as performance on course final examinations. Student performance in TBL, but not in ALG, was strongly correlated with final examination scores. Additionally, in students who performed in the upper 33rd percentile on the final examination, there was a positive correlation between final examination performance and participation in TBL and ALG. This correlation was not seen in students who performed in the lower 33rd percentile on the final examinations. Our results suggest that assessments of medical knowledge during active learning exercises could supplement non-cognitive assessments and could be good predictors of performance on summative examinations.

  16. Design e-learning with flipped learning model to improve layout understanding the concepts basic of the loop control structure

    Science.gov (United States)

    Handayani, D. P.; Sutarno, H.; Wihardi, Y.

    2018-05-01

    This study aimed in design and build e-learning with classroom flipped model to improve the concept of understanding of SMK students on the basic programming subject. Research and development obtained research data from survey questionnaire given to students of SMK class X RPL in SMK Negeri 2 Bandung and interviews to RPL productive teacher. Data also obtained from questionnaire of expert validation and students' assessment from e-learning with flipped classroom models. Data also obtained from multiple-choice test to measure improvements in conceptual understanding. The results of this research are: 1) Developed e- learning with flipped classroom model considered good and worthy of use by the average value of the percentage of 86,3% by media experts, and 85,5% by subjects matter experts, then students gave judgment is very good on e-learning either flipped classroom model with a percentage of 79,15% votes. 2) e-learning with classroom flipped models show an increase in the average value of pre-test before using e-learning 26.67 compared to the average value post-test after using e- learning at 63.37 and strengthened by the calculation of the index gains seen Increased understanding of students 'concepts by 50% with moderate criteria indicating that students' understanding is improving.

  17. Detailed magnetic and gravity surveys around the hydrothermal area off Kumejima Island in the Mid-Okinawa Trough, southwestern Japan

    Science.gov (United States)

    Kitada, K.; Kasaya, T.; Iwamoto, H.; Nogi, Y.

    2017-12-01

    The Okinawa Trough is an active back-arc basin formed by the rifting associated with extension of the continental margin behind the Ryukyu trench. New hydrothermal sites were recently discovered off Kumejima Island in the Mid-Okinawa Trough and the hydrothermal mineral deposits were identified by seafloor surveys and rock samplings by ROV (e.g., JOGMEC, 2015). In order to characterize the sub-seafloor structures and the spatial distribution of the magmatic activity around the sites, we conducted the dense magnetic, gravity and bathymetric surveys with a line spacing of 0.5 nmi aboard the R/Vs Yokosuka and Kairei, operated by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) in 2016. The geophysical data collected during the previous cruises in the area by JAMSTEC were additionally used for this study. Magnetic anomaly was calculated by subtracting the IGRF model and the magnetization intensity was estimated by the method of Parker and Huestis (1974). Free-air gravity anomaly was calculated with subtracting the normal gravity field and with corrections of the drift and of the Eötvös effect. Bouguer gravity anomaly was calculated based on the method of Parker (1972). The magnetization intensity and the Bouguer gravity anomaly reveal three characteristics of the hydrothermal area off Kumejima Island: 1) The distribution of magnetization around the hydrothermal sites shows two different types of sub-seafloor magnetic features. One is corresponded to the submarine knolls with a relatively high magnetization of 4 A/M. The other is an ENE-WSW trending magnetization distribution with relatively high and low intensities, which is consistent with the trend of the bathymetric lineament. These features are considered to be formed by magmatism associated with submarine volcanoes and back-arc rifting. 2) The reduced magnetization zone corresponding to the hydrothermal area probably attributes to hydrothermal alteration of the host rock. 3) The hydrothermal

  18. Are Vancomycin Trough Concentrations of 15 to 20 mg/L Associated With Increased Attainment of an AUC/MIC ≥ 400 in Patients With Presumed MRSA Infection?

    Science.gov (United States)

    Hale, Cory M; Seabury, Robert W; Steele, Jeffrey M; Darko, William; Miller, Christopher D

    2017-06-01

    To determine whether there is an association between higher vancomycin trough concentrations and attainment of a calculated area under the concentration-time curve (AUC)/minimum inhibitory concentration (MIC) ≥400. A retrospective analysis was conducted among vancomycin-treated adult patients with a positive methicillin-resistant Staphylococcus aureus (MRSA) culture. Attainment of a calculated AUC/MIC ≥400 was compared between patients with troughs in the reference range of 15 to 20 mg/L and those with troughs in the following ranges: 20 mg/L. Nephrotoxicity was assessed as a secondary outcome based on corrected average vancomycin troughs over 10 days of treatment. Overall, 226 patients were reviewed and 100 included. Relative to troughs ≥10, patients with vancomycin troughs AUC/MIC ≥400 (odds ratio [OR] 0.27, 95% confidence interval [CI]: 0.01-0.75). No difference was found in the attainment of an AUC/MIC ≥400 in patients with troughs of 10 to 14.9 mg/L and >20 mg/L when compared to patients with troughs of 15 to 20 mg/L. The mean corrected average vancomycin trough was higher in patients developing nephrotoxicity compared to those who did not (19.5 vs 14.5 mg/L, P AUC/MIC target relative to troughs of 10 to 14.9 mg/L but may increase nephrotoxicity risk.

  19. Shielded serpentine traveling wave tube deflection structure

    Science.gov (United States)

    Hudson, C.L.; Spector, J.

    1994-12-27

    A shielded serpentine slow wave deflection structure is disclosed having a serpentine signal conductor within a channel groove. The channel groove is formed by a serpentine channel in a trough plate and a ground plane. The serpentine signal conductor is supported at its ends by coaxial feed through connectors. A beam interaction trough intersects the channel groove to form a plurality of beam interaction regions wherein an electron beam may be deflected relative to the serpentine signal conductor. 4 figures.

  20. Does Grammatical Structure Accelerate Number Word Learning? Evidence from Learners of Dual and Non-Dual Dialects of Slovenian.

    Directory of Open Access Journals (Sweden)

    Franc Marušič

    Full Text Available How does linguistic structure affect children's acquisition of early number word meanings? Previous studies have tested this question by comparing how children learning languages with different grammatical representations of number learn the meanings of labels for small numbers, like 1, 2, and 3. For example, children who acquire a language with singular-plural marking, like English, are faster to learn the word for 1 than children learning a language that lacks the singular-plural distinction, perhaps because the word for 1 is always used in singular contexts, highlighting its meaning. These studies are problematic, however, because reported differences in number word learning may be due to unmeasured cross-cultural differences rather than specific linguistic differences. To address this problem, we investigated number word learning in four groups of children from a single culture who spoke different dialects of the same language that differed chiefly with respect to how they grammatically mark number. We found that learning a dialect which features "dual" morphology (marking of pairs accelerated children's acquisition of the number word two relative to learning a "non-dual" dialect of the same language.

  1. Does Grammatical Structure Accelerate Number Word Learning? Evidence from Learners of Dual and Non-Dual Dialects of Slovenian

    Science.gov (United States)

    Plesničar, Vesna; Razboršek, Tina; Sullivan, Jessica; Barner, David

    2016-01-01

    How does linguistic structure affect children’s acquisition of early number word meanings? Previous studies have tested this question by comparing how children learning languages with different grammatical representations of number learn the meanings of labels for small numbers, like 1, 2, and 3. For example, children who acquire a language with singular-plural marking, like English, are faster to learn the word for 1 than children learning a language that lacks the singular-plural distinction, perhaps because the word for 1 is always used in singular contexts, highlighting its meaning. These studies are problematic, however, because reported differences in number word learning may be due to unmeasured cross-cultural differences rather than specific linguistic differences. To address this problem, we investigated number word learning in four groups of children from a single culture who spoke different dialects of the same language that differed chiefly with respect to how they grammatically mark number. We found that learning a dialect which features “dual” morphology (marking of pairs) accelerated children’s acquisition of the number word two relative to learning a “non-dual” dialect of the same language. PMID:27486802

  2. Identification of the properties of rust trough the behavior of damageable structures

    International Nuclear Information System (INIS)

    Thanh, N.Q.; Berthaud, Y.; Care, S.; L' Hostis, V.; Millard, A.

    2005-01-01

    This contribution is related to the general problem of the durability of reinforced concrete. Due to corrosion enhanced by the combined effects of chlorides and sometimes by the carbonation of concrete that renders the pH low, rebars corrode. The products of corrosion various in composition are responsible for (i) the cracking of concrete (ii) the loss of section of the bars and (iii) the modification of the interface properties. This corrosion process has been widely studied but some difficulties arise. The mechanical properties of rust are still unknown although their physical properties are well identified i.e. conductivity, density... We have decided to perform corrosion test on small plates (reinforced) submitted to electrical field (to accelerate both the corrosion and the diffusion) in order to follow the evolution of concrete cracking. Small cylinders have been used to study the kinetic of corrosion. (authors)

  3. Assessing E-Learning System in Higher Education Institutes: Evidence from Structural Equation Modelling

    Science.gov (United States)

    Ali, Muhammad; Raza, Syed Ali; Qazi, Wasim; Puah, Chin-Hong

    2018-01-01

    Purpose: This study aims to examine university students' acceptance of e-learning systems in Pakistan. A Web-based learning system is a new form of utilizing technological features. Although, developed countries have initiated and established the concept for e-learning, developing countries require empirical support to implement e-learning.…

  4. A qualitative inquiry into the effects of visualization on high school chemistry students' learning process of molecular structure

    Science.gov (United States)

    Deratzou, Susan

    This research studies the process of high school chemistry students visualizing chemical structures and its role in learning chemical bonding and molecular structure. Minimal research exists with high school chemistry students and more research is necessary (Gabel & Sherwood, 1980; Seddon & Moore, 1986; Seddon, Tariq, & Dos Santos Veiga, 1984). Using visualization tests (Ekstrom, French, Harman, & Dermen, 1990a), a learning style inventory (Brown & Cooper, 1999), and observations through a case study design, this study found visual learners performed better, but needed more practice and training. Statistically, all five pre- and post-test visualization test comparisons were highly significant in the two-tailed t-test (p > .01). The research findings are: (1) Students who tested high in the Visual (Language and/or Numerical) and Tactile Learning Styles (and Social Learning) had an advantage. Students who learned the chemistry concepts more effectively were better at visualizing structures and using molecular models to enhance their knowledge. (2) Students showed improvement in learning after visualization practice. Training in visualization would improve students' visualization abilities and provide them with a way to think about these concepts. (3) Conceptualization of concepts indicated that visualizing ability was critical and that it could be acquired. Support for this finding was provided by pre- and post-Visualization Test data with a highly significant t-test. (4) Various molecular animation programs and websites were found to be effective. (5) Visualization and modeling of structures encompassed both two- and three-dimensional space. The Visualization Test findings suggested that the students performed better with basic rotation of structures as compared to two- and three-dimensional objects. (6) Data from observations suggest that teaching style was an important factor in student learning of molecular structure. (7) Students did learn the chemistry concepts

  5. Evaluation of machine learning tools for inspection of steam generator tube structures using pulsed eddy current

    Science.gov (United States)

    Buck, J. A.; Underhill, P. R.; Morelli, J.; Krause, T. W.

    2017-02-01

    Degradation of nuclear steam generator (SG) tubes and support structures can result in a loss of reactor efficiency. Regular in-service inspection, by conventional eddy current testing (ECT), permits detection of cracks, measurement of wall loss, and identification of other SG tube degradation modes. However, ECT is challenged by overlapping degradation modes such as might occur for SG tube fretting accompanied by tube off-set within a corroding ferromagnetic support structure. Pulsed eddy current (PEC) is an emerging technology examined here for inspection of Alloy-800 SG tubes and associated carbon steel drilled support structures. Support structure hole size was varied to simulate uniform corrosion, while SG tube was off-set relative to hole axis. PEC measurements were performed using a single driver with an 8 pick-up coil configuration in the presence of flat-bottom rectangular frets as an overlapping degradation mode. A modified principal component analysis (MPCA) was performed on the time-voltage data in order to reduce data dimensionality. The MPCA scores were then used to train a support vector machine (SVM) that simultaneously targeted four independent parameters associated with; support structure hole size, tube off-centering in two dimensions and fret depth. The support vector machine was trained, tested, and validated on experimental data. Results were compared with a previously developed artificial neural network (ANN) trained on the same data. Estimates of tube position showed comparable results between the two machine learning tools. However, the ANN produced better estimates of hole inner diameter and fret depth. The better results from ANN analysis was attributed to challenges associated with the SVM when non-constant variance is present in the data.

  6. Bayesian Network Constraint-Based Structure Learning Algorithms: Parallel and Optimized Implementations in the bnlearn R Package

    Directory of Open Access Journals (Sweden)

    Marco Scutari

    2017-03-01

    Full Text Available It is well known in the literature that the problem of learning the structure of Bayesian networks is very hard to tackle: Its computational complexity is super-exponential in the number of nodes in the worst case and polynomial in most real-world scenarios. Efficient implementations of score-based structure learning benefit from past and current research in optimization theory, which can be adapted to the task by using the network score as the objective function to maximize. This is not true for approaches based on conditional independence tests, called constraint-based learning algorithms. The only optimization in widespread use, backtracking, leverages the symmetries implied by the definitions of neighborhood and Markov blanket. In this paper we illustrate how backtracking is implemented in recent versions of the bnlearn R package, and how it degrades the stability of Bayesian network structure learning for little gain in terms of speed. As an alternative, we describe a software architecture and framework that can be used to parallelize constraint-based structure learning algorithms (also implemented in bnlearn and we demonstrate its performance using four reference networks and two real-world data sets from genetics and systems biology. We show that on modern multi-core or multiprocessor hardware parallel implementations are preferable over backtracking, which was developed when single-processor machines were the norm.

  7. Synthetic seismograms in laterrally heterogeneous anelastic media: Modal summation for the case of offshore seismic sources (deep-sea trough)

    International Nuclear Information System (INIS)

    Alvarez, Leonardo; Romanelli, Fabio; Panza, Giuliano F.

    2001-12-01

    While waiting for the increment of strong motion data, especially for earthquake prone areas outside the United States and Japan, a very useful approach to perform immediate site specific seismic hazard assessment is the development and use of modelling tools. They are based, on one hand, on the theoretical knowledge of the physics of the seismic source and of wave propagation and, on the other hand, on the exploitation of the relatively rich database, already available, that can be used for the definition of the source and structural models. With these input data we model the ground motion using the mode-coupling approach for sharply varying laterally heterogeneous anelastic media, i.e. computing the coupling coefficients for the modes transmitted and reflected at the vertical interface, between two quarter spaces in welded contact. The formalism can be readily applied to any laterally heterogeneous structure by using a custom series of layered anelastic structures in welded contact at vertical interfaces. The case of seismic wave propagation in smooth varying laterally heterogeneous layered media, is solved with an approximation, equivalent to WKBJ method. The theoretical formulation that combines both WKBJ and the coupling coefficients approaches, is implemented in a computer program package. The computer code we have developed allows us to calculate synthetic seismograms for a wide range of laterally inhomogeneous layered anelastic media. As a case study we use an earthquake which occurred on December 16, 1999 (m b =4.8) beneath the Bartlett sea trough, south of Santiago de Cuba city, that was recorded by an accelerometer (SMA-100) placed in Rio Carpintero (RCC) station, at an epicentral distance of about 30 Km. The path travelled by the waves corresponds to a complex structure from undersea source to inland seismic station. A good fit between the observed transverse component (SH-waves) of acceleration and the corresponding synthetic signal is obtained for a

  8. A machine learning approach to automated structural network analysis: application to neonatal encephalopathy.

    Directory of Open Access Journals (Sweden)

    Etay Ziv

    Full Text Available Neonatal encephalopathy represents a heterogeneous group of conditions associated with life-long developmental disabilities and neurological deficits. Clinical measures and current anatomic brain imaging remain inadequate predictors of outcome in children with neonatal encephalopathy. Some studies have suggested that brain development and, therefore, brain connectivity may be altered in the subgroup of patients who subsequently go on to develop clinically significant neurological abnormalities. Large-scale structural brain connectivity networks constructed using diffusion tractography have been posited to reflect organizational differences in white matter architecture at the mesoscale, and thus offer a unique tool for characterizing brain development in patients with neonatal encephalopathy. In this manuscript we use diffusion tractography to construct structural networks for a cohort of patients with neonatal encephalopathy. We systematically map these networks to a high-dimensional space and then apply standard machine learning algorithms to predict neurological outcome in the cohort. Using nested cross-validation we demonstrate high prediction accuracy that is both statistically significant and robust over a broad range of thresholds. Our algorithm offers a novel tool to evaluate neonates at risk for developing neurological deficit. The described approach can be applied to any brain pathology that affects structural connectivity.

  9. Super learning to hedge against incorrect inference from arbitrary parametric assumptions in marginal structural modeling.

    Science.gov (United States)

    Neugebauer, Romain; Fireman, Bruce; Roy, Jason A; Raebel, Marsha A; Nichols, Gregory A; O'Connor, Patrick J

    2013-08-01

    Clinical trials are unlikely to ever be launched for many comparative effectiveness research (CER) questions. Inferences from hypothetical randomized trials may however be emulated with marginal structural modeling (MSM) using observational data, but success in adjusting for time-dependent confounding and selection bias typically relies on parametric modeling assumptions. If these assumptions are violated, inferences from MSM may be inaccurate. In this article, we motivate the application of a data-adaptive estimation approach called super learning (SL) to avoid reliance on arbitrary parametric assumptions in CER. Using the electronic health records data from adults with new-onset type 2 diabetes, we implemented MSM with inverse probability weighting (IPW) estimation to evaluate the effect of three oral antidiabetic therapies on the worsening of glomerular filtration rate. Inferences from IPW estimation were noticeably sensitive to the parametric assumptions about the associations between both the exposure and censoring processes and the main suspected source of confounding, that is, time-dependent measurements of hemoglobin A1c. SL was successfully implemented to harness flexible confounding and selection bias adjustment from existing machine learning algorithms. Erroneous IPW inference about clinical effectiveness because of arbitrary and incorrect modeling decisions may be avoided with SL. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Automated Quality Assessment of Structural Magnetic Resonance Brain Images Based on a Supervised Machine Learning Algorithm

    Directory of Open Access Journals (Sweden)

    Ricardo Andres Pizarro

    2016-12-01

    Full Text Available High-resolution three-dimensional magnetic resonance imaging (3D-MRI is being increasingly used to delineate morphological changes underlying neuropsychiatric disorders. Unfortunately, artifacts frequently compromise the utility of 3D-MRI yielding irreproducible results, from both type I and type II errors. It is therefore critical to screen 3D-MRIs for artifacts before use. Currently, quality assessment involves slice-wise visual inspection of 3D-MRI volumes, a procedure that is both subjective and time consuming. Automating the quality rating of 3D-MRI could improve the efficiency and reproducibility of the procedure. The present study is one of the first efforts to apply a support vector machine (SVM algorithm in the quality assessment of structural brain images, using global and region of interest (ROI automated image quality features developed in-house. SVM is a supervised machine-learning algorithm that can predict the category of test datasets based on the knowledge acquired from a learning dataset. The performance (accuracy of the automated SVM approach was assessed, by comparing the SVM-predicted quality labels to investigator-determined quality labels. The accuracy for classifying 1457 3D-MRI volumes from our database using the SVM approach is around 80%. These results are promising and illustrate the possibility of using SVM as an automated quality assessment tool for 3D-MRI.

  11. Automated Quality Assessment of Structural Magnetic Resonance Brain Images Based on a Supervised Machine Learning Algorithm.

    Science.gov (United States)

    Pizarro, Ricardo A; Cheng, Xi; Barnett, Alan; Lemaitre, Herve; Verchinski, Beth A; Goldman, Aaron L; Xiao, Ena; Luo, Qian; Berman, Karen F; Callicott, Joseph H; Weinberger, Daniel R; Mattay, Venkata S

    2016-01-01

    High-resolution three-dimensional magnetic resonance imaging (3D-MRI) is being increasingly used to delineate morphological changes underlying neuropsychiatric disorders. Unfortunately, artifacts frequently compromise the utility of 3D-MRI yielding irreproducible results, from both type I and type II errors. It is therefore critical to screen 3D-MRIs for artifacts before use. Currently, quality assessment involves slice-wise visual inspection of 3D-MRI volumes, a procedure that is both subjective and time consuming. Automating the quality rating of 3D-MRI could improve the efficiency and reproducibility of the procedure. The present study is one of the first efforts to apply a support vector machine (SVM) algorithm in the quality assessment of structural brain images, using global and region of interest (ROI) automated image quality features developed in-house. SVM is a supervised machine-learning algorithm that can predict the category of test datasets based on the knowledge acquired from a learning dataset. The performance (accuracy) of the automated SVM approach was assessed, by comparing the SVM-predicted quality labels to investigator-determined quality labels. The accuracy for classifying 1457 3D-MRI volumes from our database using the SVM approach is around 80%. These results are promising and illustrate the possibility of using SVM as an automated quality assessment tool for 3D-MRI.

  12. Acquiring and processing verb argument structure: distributional learning in a miniature language.

    Science.gov (United States)

    Wonnacott, Elizabeth; Newport, Elissa L; Tanenhaus, Michael K

    2008-05-01

    Adult knowledge of a language involves correctly balancing lexically-based and more language-general patterns. For example, verb argument structures may sometimes readily generalize to new verbs, yet with particular verbs may resist generalization. From the perspective of acquisition, this creates significant learnability problems, with some researchers claiming a crucial role for verb semantics in the determination of when generalization may and may not occur. Similarly, there has been debate regarding how verb-specific and more generalized constraints interact in sentence processing and on the role of semantics in this process. The current work explores these issues using artificial language learning. In three experiments using languages without semantic cues to verb distribution, we demonstrate that learners can acquire both verb-specific and verb-general patterns, based on distributional information in the linguistic input regarding each of the verbs as well as across the language as a whole. As with natural languages, these factors are shown to affect production, judgments and real-time processing. We demonstrate that learners apply a rational procedure in determining their usage of these different input statistics and conclude by suggesting that a Bayesian perspective on statistical learning may be an appropriate framework for capturing our findings.

  13. Incentive structure in team-based learning: graded versus ungraded Group Application exercises.

    Science.gov (United States)

    Deardorff, Adam S; Moore, Jeremy A; McCormick, Colleen; Koles, Paul G; Borges, Nicole J

    2014-04-21

    Previous studies on team-based learning (TBL) in medical education demonstrated improved learner engagement, learner satisfaction, and academic performance; however, a paucity of information exists on modifications of the incentive structure of "traditional" TBL practices. The current study investigates the impact of modification to conventional Group Application exercises by examining student preference and student perceptions of TBL outcomes when Group Application exercises are excluded from TBL grades. During the 2009-2010 and 2010-2011 academic years, 175 students (95.6% response rate) completed a 22-item multiple choice survey followed by 3 open response questions at the end of their second year of medical school. These students had participated in a TBL supplemented preclinical curriculum with graded Group Application exercises during year one and ungraded Group Application exercises during year two of medical school. Chi-square analyses showed significant differences between grading categories for general assessment of TBL, participation and communication, intra-team discussion, inter-team discussion, student perceptions of their own effort and development of teamwork skills. Furthermore, 83.8% of students polled prefer ungraded Group Application exercises with only 7.2% preferring graded and 9.0% indicating no preference. The use of ungraded Group Application exercises appears to be a successful modification of TBL, making it more "student-friendly" while maintaining the goals of active learning and development of teamwork skills.

  14. A uranium-based UO_2"+-Mn"2"+ single-chain magnet assembled trough cation-cation interactions

    International Nuclear Information System (INIS)

    Mougel, Victor; Chatelain, Lucile; Hermle, Johannes; Pecaut, Jacques; Mazzanti, Marinella; Caciuffo, Roberto; Colineau, Eric; Tuna, Floriana; Magnani, Nicola; Geyer, Arnaud de

    2014-01-01

    Single-chain magnets (SCMs) are materials composed of magnetically isolated one-dimensional (1D) units exhibiting slow relaxation of magnetization. The occurrence of SCM behavior requires the fulfillment of stringent conditions for exchange and anisotropy interactions. Herein, we report the synthesis, the structure, and the magnetic characterization of the first actinide-containing SCM. The 5f-3d heterometallic 1D chains [{[UO_2(salen)(py)][M(py)_4](NO_3)}]_n, (M=Cd (1) and M=Mn (2); py=pyridine) are assembled trough cation-cation interaction from the reaction of the uranyl(V) complex [UO_2(salen)py][Cp"*_2Co] (Cp"*=pentamethylcyclopentadienyl) with Cd(NO_3)_2 or Mn(NO_3)_2 in pyridine. The infinite UMn chain displays a high relaxation barrier of 134±0.8 K (93±0.5 cm"-"1), probably as a result of strong intra-chain magnetic interactions combined with the high Ising anisotropy of the uranyl(V) dioxo group. It also exhibits an open magnetic hysteresis loop at T<6 K, with an impressive coercive field of 3.4 T at 2 K.

  15. A uranium-based UO_2"+-Mn"2"+ single-chain magnet assembled trough cation-cation interactions

    International Nuclear Information System (INIS)

    Mougel, Victor; Chatelain, Lucile; Hermle, Johannes; Pecaut, Jacques; Mazzanti, Marinella; Caciuffo, Roberto; Colineau, Eric; Tuna, Floriana; Magnani, Nicola; Geyer, Arnaud de

    2014-01-01

    Single-chain magnets (SCMs) are materials composed of magnetically isolated one-dimensional (1D) units exhibiting slow relaxation of magnetization. The occurrence of SCM behavior requires the fulfillment of stringent conditions for exchange and anisotropy interactions. Herein, we report the synthesis, the structure, and the magnetic characterization of the first actinide-containing SCM. The 5f-3d heterometallic 1D chains [{[UO_2(salen)(py)][M(py)_4](NO_3)}]_n, (M=Cd (1) and M=Mn (2); py=pyridine) are assembled trough cation-cation interaction from the reaction of the uranyl(V) complex [UO_2(salen)py][Cp*_2Co] (Cp*=pentamethylcyclopentadienyl) with Cd(NO_3)_2 or Mn(NO_3)_2 in pyridine. The infinite UMn chain displays a high relaxation barrier of 134 ±0.8 K (93 ±0.5 cm"-"1), probably as a result of strong intra-chain magnetic interactions combined with the high Ising anisotropy of the uranyl(V) dioxo group. It also exhibits an open magnetic hysteresis loop at T <6 K, with an impressive coercive field of 3.4 T at 2 K. (Copyright copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Study on the Instability of Two-Phase Flow in the Heat-Absorbing Tube of Trough Solar Collector

    Directory of Open Access Journals (Sweden)

    Ying Zhang

    2017-01-01

    Full Text Available The Marangoni effect and Rayleigh-Benard effect in the two-phase region of solar trough heat-absorbing tube are simulated by FTM (front tracking method. Considering the Marangoni effect alone, although surface tension gradient and surface tension affect the interface wave, the two effects have different characteristics. The surface tension gradient caused by the temperature gradient is one of the factors that swing the interface. The amplitude attenuation of the interface wave decreases with the increase of the Marangoni number (Ma. In general, the surface tension gradient enhances the convection opposite to the temperature gradient. Under the gravity field, the Rayleigh-Benard effect influences the development of the vortex structure in the flow field, which in turn affects the velocity gradient near the interface to influence the evolution of the interface fluctuation. In a small Rayleigh number (Ra, the buoyancy convection reduces the velocity gradient, thus suppressing the evolution of the interfacial wave. In the range of Ra  4.0E4, the situation is just the opposite. The larger the Ra is, the stronger the promoting effect is.

  17. The glacially overdeepened trough of the Salzach Valley, Austria: Bedrock geometry and sedimentary fill of a major Alpine subglacial basin

    Science.gov (United States)

    Pomper, Johannes; Salcher, Bernhard C.; Eichkitz, Christoph; Prasicek, Günther; Lang, Andreas; Lindner, Martin; Götz, Joachim

    2017-10-01

    Overdeepened valleys are unambiguous features of glacially sculpted landscapes. They result from erosion at the bed of the glacier and their size and shape is determined by ice dynamics and the characteristics of the underlying bedrock. Major overdeepened valleys representing vertical bedrock erosion of several hundreds of meters are characteristic features of many trunk valleys in the formerly glaciated parts of the Alpine mountain belt. The thick sedimentary fill usually hinders attempts to unravel bedrock geometry, formation history and fill characteristics. Based on reflection seismic data and core-logs from multiple deep drillings we construct a detailed bedrock model of the Lower Salzach Valley trough, one of the largest overdeepened valleys in the European Alps. The analysed overdeepened structure characterized by a strongly undulating topography. Two reaches of enhanced erosion can be identified and are suggested to be related to variations in bedrock erodibility and a triple glacier confluence. The sedimentary fill shows clear characteristics of rapid infilling and subaqueous fan delta deposits indicate a strong influence of tributary streams. Associated surface lowering of the valley floor had a major impact on tributary stream incision but also on the available ice accumulation area at subsequent glaciations. The extent to which fills of earlier glaciations have been preserved from erosion during the last glacial maximum remains ambiguous and demands further exploration. To our knowledge the presented bedrock model is one of the best defined of any major overdeepened trunk valley.

  18. On open questions in the geometric approach to structural learning Bayesian nets

    Czech Academy of Sciences Publication Activity Database

    Studený, Milan; Vomlel, Jiří

    2011-01-01

    Roč. 52, č. 5 (2011), s. 627-640 ISSN 0888-613X. [Workshop on Uncertainty Processing WUPES'09 /8./. Liblice, 19.09.2009-23.09.2009] R&D Projects: GA MŠk(CZ) 1M0572; GA ČR GA201/08/0539; GA ČR GEICC/08/E010 Grant - others:GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : structural learning Bayesian nets * standard imset * polytope * geometric neighborhood * differential imset Subject RIV: BA - General Mathematics Impact factor: 1.948, year: 2011 http://library.utia.cas.cz/separaty/2011/MTR/studeny-0358907. pdf

  19. The relationship between strategic control and conscious structural knowledge in artificial grammar learning.

    Science.gov (United States)

    Norman, Elisabeth; Scott, Ryan B; Price, Mark C; Dienes, Zoltan

    2016-05-01

    We address Jacoby's (1991) proposal that strategic control over knowledge requires conscious awareness of that knowledge. In a two-grammar artificial grammar learning experiment all participants were trained on two grammars, consisting of a regularity in letter sequences, while two other dimensions (colours and fonts) varied randomly. Strategic control was measured as the ability to selectively apply the grammars during classification. For each classification, participants also made a combined judgement of (a) decision strategy and (b) relevant stimulus dimension. Strategic control was found for all types of decision strategy, including trials where participants claimed to lack conscious structural knowledge. However, strong evidence of strategic control only occurred when participants knew or guessed that the letter dimension was relevant, suggesting that strategic control might be associated with - or even causally requires - global awareness of the nature of the rules even though it does not require detailed knowledge of their content. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  20. What can we learn from structure functions measured in neutrino interactions

    International Nuclear Information System (INIS)

    Eisele, F.

    1981-01-01

    The new measurements of structure functions by the CDHS-collaboration are substantially improved compared to published results. It is discussed how much we can learn from these data about QCD and the gluon distribution by the analysis of moments and of the full x-dependence. It is shown that these new data combined with SLAC ed-data are able to separate QCD-effects from higher twist and other possible non perturbative effects within ''reasonable'' assumptions. The presence of non perturbative contributions is required at large x (x larger or equal 5) and low Q 2 only. Their shape and magnitude agree well with popular models of diquark contributions. The analysis results in a value of Λsub(MS-bar) = .2+-.1. (author)

  1. NDT with the structural weld overlay program. Recent field experience and lessons learned

    International Nuclear Information System (INIS)

    Rishel, R.; Lenz, H.; Turley, G.; Newton, B.

    2007-01-01

    Structural weld overlay (SWOL) has become a predominant mitigation technique within the Alloy 600 program. For the pressurizer nozzles, MRP-139 requires volumetric examination by year end 2007. Many nozzles are un-inspectable due to geometry and material limitations that preclude interrogation of the required examination volume. SWOL therefore is the mitigation technique which overcomes these limitations. SWOL of the pressurizer nozzles has been a challenge for all the vendors. Alloy 52 has proven to be difficult to weld under field conditions. The NDT technique chosen to demonstrate the integrity of the overlay needs to be adapted to the specific repair process and nozzle geometry. The purpose of this paper will be to present Westinghouse's integrated approach for SWOL with the focus on the NDT aspects. Topics will include main repair process steps, NDT qualification, recent field experience and lessons learned. (author)

  2. Harnessing user generated multimedia content in the creation of collaborative classification structures and retrieval learning games

    Science.gov (United States)

    Borchert, Otto Jerome

    This paper describes a software tool to assist groups of people in the classification and identification of real world objects called the Classification, Identification, and Retrieval-based Collaborative Learning Environment (CIRCLE). A thorough literature review identified current pedagogical theories that were synthesized into a series of five tasks: gathering, elaboration, classification, identification, and reinforcement through game play. This approach is detailed as part of an included peer reviewed paper. Motivation is increased through the use of formative and summative gamification; getting points completing important portions of the tasks and playing retrieval learning based games, respectively, which is also included as a peer-reviewed conference proceedings paper. Collaboration is integrated into the experience through specific tasks and communication mediums. Implementation focused on a REST-based client-server architecture. The client is a series of web-based interfaces to complete each of the tasks, support formal classroom interaction through faculty accounts and student tracking, and a module for peers to help each other. The server, developed using an in-house JavaMOO platform, stores relevant project data and serves data through a series of messages implemented as a JavaScript Object Notation Application Programming Interface (JSON API). Through a series of two beta tests and two experiments, it was discovered the second, elaboration, task requires considerable support. While students were able to properly suggest experiments and make observations, the subtask involving cleaning the data for use in CIRCLE required extra support. When supplied with more structured data, students were enthusiastic about the classification and identification tasks, showing marked improvement in usability scores and in open ended survey responses. CIRCLE tracks a variety of educationally relevant variables, facilitating support for instructors and researchers. Future

  3. A New Model of Lithosphere Deformation Beneath the Okinawa Trough Based on Gravity Data

    Institute of Scientific and Technical Information of China (English)

    ZHAO Lihong; JIANG Xiaodian; ZHANG Weigang

    2002-01-01

    The Ryukyu trench-arc system can be divided into two types according to its subduction model. The normal sub-duction in the northern part of the Philippine Sea plate creates a hinge sedimentary wedge with large deformation at the col-lision front, while the oblique subduction in the southern part gives rise to a smaller accretion with small deformation thanthat in the northern part. The mechanisms that cause the distinction between these two types have been analysed and calcu-lated by using gravity data based on the lithosphere rheology and the stress state of the lithosphere in the subduction bound-ary. The two types of subduction model are associated with the internal extension in the southern Okinawa Trough and thesmall extension in the northern part. The difference of the stress state between the two types of subduction model is alsomanifested in other tectonic features, such as topography, volcanic activity and crust movement. Modeling bathymetric andgravity data from this area suggests that the oblique subduction of low angle, together with smooth geometry of the overlyingplate crust, results in small stress released on the south of the trench by the subduction plate. The intraplate faults in thesouthern Okinawa Trough behind the trench stand in surplus intensive stress. On the other hand, the normal subduction ofhigh angle, together with strong undulation geometry of the overlying crust, results in more intensive stress released in thenorthern Ryukyu Trench than that in the south. The intraplate faults in the northern Okinawa Trough behind the northernRyukyu Trench stand in small stress.

  4. LCOE reduction potential of parabolic trough and solar tower CSP technology until 2025

    Science.gov (United States)

    Dieckmann, Simon; Dersch, Jürgen; Giuliano, Stefano; Puppe, Michael; Lüpfert, Eckhard; Hennecke, Klaus; Pitz-Paal, Robert; Taylor, Michael; Ralon, Pablo

    2017-06-01

    Concentrating Solar Power (CSP), with an installed capacity of 4.9 GW by 2015, is a young technology compared to other renewable power generation technologies. A limited number of plants and installed capacity in a small challenging market environment make reliable and transparent cost data for CSP difficult to obtain. The International Renewable Energy Agency (IRENA) and the DLR German Aerospace Center gathered and evaluated available cost data from various sources for this publication in order to yield transparent, reliable and up-to-date cost data for a set of reference parabolic trough and solar tower plants in the year 2015 [1]. Each component of the power plant is analyzed for future technical innovations and cost reduction potential based on current R&D activities, ongoing commercial developments and growth in market scale. The derived levelized cost of electricity (LCOE) for 2015 and 2025 are finally contrasted with published power purchase agreements (PPA) of the NOOR II+III power plants in Morocco. At 7.5% weighted average cost of capital (WACC) and 25 years economic life time, the levelized costs of electricity for plants with 7.5 (trough) respectively 9 (tower) full-load hours thermal storage capacity decrease from 14-15 -ct/kWh today to 9-10 -ct/kWh by 2025 for both technologies at direct normal irradiation of 2500 kWh/(m².a). The capacity factor increases from 41.1% to 44.6% for troughs and from 45.5% to 49.0% for towers. Financing conditions are a major cost driver and offer potential for further cost reduction with the maturity of the technology and low interest rates (6-7 - ct/kWh for 2% WACC at 2500 kWh/(m2.a) in 2025).

  5. Accurate relocation of seismicity along the North Aegean Trough and its relation to active tectonics

    Science.gov (United States)

    Konstantinou, K. I.

    2017-10-01

    The tectonics of northern Aegean are affected by the westward push of Anatolia and the gravitational spreading of the Aegean lithosphere that promote transtensional deformation in the area. This regime is also responsible for the creation of a series of pull-apart basins, collectively known as the North Aegean Trough. This work accurately relocates a total of 2300 earthquakes that were recorded along the North Aegean Trough during 2011-2016 by stations of the Hellenic Unified Seismic Network (HUSN) and strong-motion sensors. Absolute locations for these events were obtained using a nonlinear probabilistic algorithm and utilizing a minimum 1D velocity model with station corrections. The hypocentral depth distribution of these events shows a peak at 8 km diminishing gradually down to 20 km. A systematic overestimation of hypocentral depths is observed in the routine locations provided by the National Observatory of Athens where the majority of events appear to be deeper than 15 km. In order to obtain more accurate relative locations these events were relocated using the double-difference method. A total of 1693 events were finally relocated with horizontal and vertical uncertainties that do not exceed 0.11 km and 0.22 km respectively. Well-defined clusters of seismicity can be observed along the Saros and Sporades basins as well as the Kassandra and Sithonia peninsulas. These clusters either occur along the well-known NE-SW strike-slip faults bounding the basins, or along normal faults whose strike is perpendicular to the regional minimum stress axis. Locking depth along the North Aegean Trough is found to be remarkably stable between 13 and 17 km. This is likely a consequence of simultaneous reduction along the SW direction of heat flow (from 89 to 51 mW/m2) and strain rate (from 600 to 50 nstrain/yr) whose opposite effects are canceled out, precluding any sharp changes in locking depth.

  6. Thermal and chemical variations of the Nigerian Benue trough lead-zinc-barite-fluorite deposits

    Science.gov (United States)

    Ogundipe, Ibukun Emmanuel

    2017-08-01

    The Benue trough is an intra-continental rift initiated in the Cretaceous during the opening of the South Atlantic Ocean. Lead-zinc-barite-fluorite mineralization occurs along the 600 km axis of the trough in three discrete sub-basins which coincide with the lower, middle and upper mineral districts of the Benue Valley. Lithologically these sub-basins are dominated by black carbonaceous shale in the Lower Benue, platform carbonates in the Middle Benue and sandstones in the Upper Benue. Micro-thermometric analysis of fluid inclusions in sphalerite, fluorite, barite and quartz have shown that each mineral district has its own unique thermal and chemical imprint. For example, the temperature can be bracketed between 109 °C and 160 °C for lower Benue, 89 °C-144 °C for the Middle Benue and 176 °C-254 °C for the Upper Benue. Chemical differentiation also exists between each mineral district with the Lower Benue having 22 wt % equivalent NaCl while the Middle and Upper Benue have 18 and 16 wt % equivalent NaCl respectively. This study shows that inter-district thermal and chemical variations exist between the ore-stage sulfide and post-sulfide gangue minerals of the entire Benue Valley. Similarly, intra-district thermal and chemical variations have also been observed among all the paragenetic minerals of each district. The thermal variations may be as a result of variations in the geothermal gradient accompanying continental rifting from one district to the other. The variations in the chemistry between the Lower Benue and the Upper Benue paragenic minerals may be as a result of the distinct lithological differences across the Benue Trough.

  7. Towards to Resilience Science -Research on the Nankai trough seismogenic zone-

    Science.gov (United States)

    Kaneda, Yoshiyuki; Shiraki, Wataru; Fujisawa, Kazuhito; Tokozakura, Eiji

    2017-04-01

    For the last few decades, many destructive earthquakes and tsunamis occurred in the world. Based on lessons learnt from 2004 Sumatra Earthquake/Tsunamis, 2010 Chilean Earthquake/Tsunami and 2011 East Japan Earthquake/Tsunami, we recognized the importance of real time monitoring on Earthquakes and Tsunamis for disaster mitigation. Recently, Kumamoto Earthquake occurred in 2006. This destructive Earthquake indicated that multi strong motions including pre shock and main shock generated severe earthquake damages buildings. Furthermore, we recognize recovers/ revivals are very important and difficult. In Tohoku area damaged by large tsunamis, recovers/revivals have been under progressing after over 5 years passed after the 2011 Tohoku Earthquake. Therefore, we have to prepare the pre plan before next destructive disasters such as the Nankai trough mega thrust earthquake. As one of disaster countermeasures, we would like to propose that Disaster Mitigation Science. This disaster mitigation science is including engineering, science, medicine and social science such as sociology, informatics, law, literature, art, psychology etc. For Urgent evacuations, there are some kinds of real time monitoring system such as Dart buoy and ocean floor network. Especially, the real time monitoring system using multi kinds of sensors such as the accelerometer, broadband seismometer, pressure gauge, difference pressure gauge, hydrophone and thermometer is indispensable for Earthquakes/ Tsunamis monitoring. Furthermore, using multi kind of sensors, we can analyze and estimate broadband crustal activities around mega thrust earthquake seismogenic zones. Therefore, we deployed DONET1 and DONET2 which are dense ocean floor networks around the Nankai trough Southwestern Japan. We will explain about Resilience Science and real time monitoring systems around the Nankai trough seismogenic zone.

  8. Experimental test of a novel multi-surface trough solar concentrator for air heating

    International Nuclear Information System (INIS)

    Zheng Hongfei; Tao Tao; Ma Ming; Kang Huifang; Su Yuehong

    2012-01-01

    Highlights: ► We made a prototype novel multi-surface trough solar concentrator for air heating. ► Circular and rectangular types of receiver were chosen for air heating in the test. ► The changes of instantaneous system efficiency with different air flow were obtained. ► The system has the advantage of high collection temperature, which can be over 140 °C. ► The average efficiency can exceed 45% at the outlet temperature of above 60 °C. - Abstract: This study presents the experimental test of a novel multi-surface trough solar concentrator for air heating. Three receivers of different air flow channels are individually combined with the solar concentrator. The air outlet temperature and solar irradiance were recorded for different air flow rates under the real weather condition and used to determine the collection efficiency and time constant of the air heater system. The characteristics of the solar air heater with different airflow channels are compared, and the variation of the daily efficiency with the normalized temperature change is also presented. The testing results indicates that the highest temperature of the air heater with a circular glass receiver can be over 140 °C. When the collection temperature is around 60 °C, the collection efficiency can be over 45%. For the rectangular receivers, the system also has a considerable daily efficiency at a larger air flow rate. The air heater based on the novel trough solar concentrator would be suitable for space heating and drying applications.

  9. Multi-Scale Peak and Trough Detection Optimised for Periodic and Quasi-Periodic Neuroscience Data.

    Science.gov (United States)

    Bishop, Steven M; Ercole, Ari

    2018-01-01

    The reliable detection of peaks and troughs in physiological signals is essential to many investigative techniques in medicine and computational biology. Analysis of the intracranial pressure (ICP) waveform is a particular challenge due to multi-scale features, a changing morphology over time and signal-to-noise limitations. Here we present an efficient peak and trough detection algorithm that extends the scalogram approach of Scholkmann et al., and results in greatly improved algorithm runtime performance. Our improved algorithm (modified Scholkmann) was developed and analysed in MATLAB R2015b. Synthesised waveforms (periodic, quasi-periodic and chirp sinusoids) were degraded with white Gaussian noise to achieve signal-to-noise ratios down to 5 dB and were used to compare the performance of the original Scholkmann and modified Scholkmann algorithms. The modified Scholkmann algorithm has false-positive (0%) and false-negative (0%) detection rates identical to the original Scholkmann when applied to our test suite. Actual compute time for a 200-run Monte Carlo simulation over a multicomponent noisy test signal was 40.96 ± 0.020 s (mean ± 95%CI) for the original Scholkmann and 1.81 ± 0.003 s (mean ± 95%CI) for the modified Scholkmann, demonstrating the expected improvement in runtime complexity from [Formula: see text] to [Formula: see text]. The accurate interpretation of waveform data to identify peaks and troughs is crucial in signal parameterisation, feature extraction and waveform identification tasks. Modification of a standard scalogram technique has produced a robust algorithm with linear computational complexity that is particularly suited to the challenges presented by large, noisy physiological datasets. The algorithm is optimised through a single parameter and can identify sub-waveform features with minimal additional overhead, and is easily adapted to run in real time on commodity hardware.

  10. Nonimaging secondary concentrators for large rim angle parabolic troughs with tubular absorbers.

    Science.gov (United States)

    Ries, H; Spirkl, W

    1996-05-01

    For parabolic trough solar collectors with tubular absorbers, we design new tailored secondary concentrators. The design is applicable for any rim angle of a parabolic reflector. With the secondary, the concentration can be increased by a factor of more than 2 with a compact secondary reflector consisting of a single piece, even for the important case of a rim angle of 90 deg. The parabolic reflector can be used without changes; the reduced absorber is still tubular but smaller than the original absorber and slightly displaced toward the primary.

  11. Object-oriented simulation model of a parabolic trough solar collector: Static and dynamic validation

    Science.gov (United States)

    Ubieta, Eduardo; Hoyo, Itzal del; Valenzuela, Loreto; Lopez-Martín, Rafael; Peña, Víctor de la; López, Susana

    2017-06-01

    A simulation model of a parabolic-trough solar collector developed in Modelica® language is calibrated and validated. The calibration is performed in order to approximate the behavior of the solar collector model to a real one due to the uncertainty in some of the system parameters, i.e. measured data is used during the calibration process. Afterwards, the validation of this calibrated model is done. During the validation, the results obtained from the model are compared to the ones obtained during real operation in a collector from the Plataforma Solar de Almeria (PSA).

  12. Manic-Like Psychosis Associated with Elevated Trough Tacrolimus Blood Concentrations 17 Years after Kidney Transplant

    Directory of Open Access Journals (Sweden)

    Giuseppe Bersani

    2013-01-01

    Full Text Available Several neurological side effects induced by tacrolimus are described in the scientific literature, ranging from mild neurological symptoms to delirium and psychosis. We report the case of a 46-year-old man with no prior psychiatric history who suddenly manifested manic-like psychosis associated with elevated trough tacrolimus blood concentrations 17 years after kidney transplant. The use of antipsychotics may improve the severity of symptoms; but in order to obtain a complete remission, the reduction in the dose of tacrolimus, or its replacement with alternative immunosuppressant therapies, is recommended.

  13. Machine learning for the structure-energy-property landscapes of molecular crystals.

    Science.gov (United States)

    Musil, Félix; De, Sandip; Yang, Jack; Campbell, Joshua E; Day, Graeme M; Ceriotti, Michele

    2018-02-07

    Molecular crystals play an important role in several fields of science and technology. They frequently crystallize in different polymorphs with substantially different physical properties. To help guide the synthesis of candidate materials, atomic-scale modelling can be used to enumerate the stable polymorphs and to predict their properties, as well as to propose heuristic rules to rationalize the correlations between crystal structure and materials properties. Here we show how a recently-developed machine-learning (ML) framework can be used to achieve inexpensive and accurate predictions of the stability and properties of polymorphs, and a data-driven classification that is less biased and more flexible than typical heuristic rules. We discuss, as examples, the lattice energy and property landscapes of pentacene and two azapentacene isomers that are of interest as organic semiconductor materials. We show that we can estimate force field or DFT lattice energies with sub-kJ mol -1 accuracy, using only a few hundred reference configurations, and reduce by a factor of ten the computational effort needed to predict charge mobility in the crystal structures. The automatic structural classification of the polymorphs reveals a more detailed picture of molecular packing than that provided by conventional heuristics, and helps disentangle the role of hydrogen bonded and π-stacking interactions in determining molecular self-assembly. This observation demonstrates that ML is not just a black-box scheme to interpolate between reference calculations, but can also be used as a tool to gain intuitive insights into structure-property relations in molecular crystal engineering.

  14. Transcriptome-guided amyloid imaging genetic analysis via a novel structured sparse learning algorithm.

    Science.gov (United States)

    Yan, Jingwen; Du, Lei; Kim, Sungeun; Risacher, Shannon L; Huang, Heng; Moore, Jason H; Saykin, Andrew J; Shen, Li

    2014-09-01

    Imaging genetics is an emerging field that studies the influence of genetic variation on brain structure and function. The major task is to examine the association between genetic markers such as single-nucleotide polymorphisms (SNPs) and quantitative traits (QTs) extracted from neuroimaging data. The complexity of these datasets has presented critical bioinformatics challenges that require new enabling tools. Sparse canonical correlation analysis (SCCA) is a bi-multivariate technique used in imaging genetics to identify complex multi-SNP-multi-QT associations. However, most of the existing SCCA algorithms are designed using the soft thresholding method, which assumes that the input features are independent from one another. This assumption clearly does not hold for the imaging genetic data. In this article, we propose a new knowledge-guided SCCA algorithm (KG-SCCA) to overcome this limitation as well as improve learning results by incorporating valuable prior knowledge. The proposed KG-SCCA method is able to model two types of prior knowledge: one as a group structure (e.g. linkage disequilibrium blocks among SNPs) and the other as a network structure (e.g. gene co-expression network among brain regions). The new model incorporates these prior structures by introducing new regularization terms to encourage weight similarity between grouped or connected features. A new algorithm is designed to solve the KG-SCCA model without imposing the independence constraint on the input features. We demonstrate the effectiveness of our algorithm with both synthetic and real data. For real data, using an Alzheimer's disease (AD) cohort, we examine the imaging genetic associations between all SNPs in the APOE gene (i.e. top AD gene) and amyloid deposition measures among cortical regions (i.e. a major AD hallmark). In comparison with a widely used SCCA implementation, our KG-SCCA algorithm produces not only improved cross-validation performances but also biologically meaningful

  15. Cross-cultural comparisons of university students' science learning self-efficacy: structural relationships among factors within science learning self-efficacy

    Science.gov (United States)

    Wang, Ya-Ling; Liang, Jyh-Chong; Tsai, Chin-Chung

    2018-04-01

    Science learning self-efficacy could be regarded as a multi-factor belief which comprises different aspects such as cognitive skills, practical work, and everyday application. However, few studies have investigated the relationships among these factors that compose science learning self-efficacy. Also, culture may play an important role in explaining the relationships among these factors. Accordingly, this study aimed to investigate cultural differences in science learning self-efficacy and examine the relationships within factors constituting science learning self-efficacy by adopting a survey instrument for administration to students in the U.S. and Taiwan. A total of 218 university students (62.40% females) were surveyed in the U.S.A, and 224 university students (49.10% females) in Taiwan were also invited to take part in the study. The results of the structural equation modelling revealed cultural differences in the relationships among the factors of science learning self-efficacy. It was found that U.S. students' confidence in their ability to employ higher-order cognitive skills tended to promote their confidence in their ability to accomplish practical work, strengthening their academic self-efficacy. However, the aforementioned mediation was not found for the Taiwanese participants.

  16. Field occurrence and geochemical characteristics of the baryte mineralization in Lessel and Ihugh areas, Lower Benue Trough, Nigeria

    Science.gov (United States)

    Labe, Ngukposu A.; Ogunleye, Paul O.; Ibrahim, Aliyu A.

    2018-06-01

    The Lessel and Ihugh areas are underlain by Precambrian rocks comprising of banded gneiss, medium-grained muscovite granite, coarse-grained biotite muscovite granite, and Turonian arenaceous Lessel Sandstone in the Lower Benue Trough, southeastern Nigeria. Baryte mineralization occurs at Lessel-Mbagwa, Ihugh and Bunde commonly as vein and cavity type deposits within NE-SW and NW-SE trending fracture zones. Major oxides and trace element analysis of baryte and the host rocks was undertaken using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), in order to establish the geochemical characteristics and to constrain the origin of the baryte mineralization. The data revealed enrichment in Ba and Sr and depletion in SiO2, TiO2, Al2O3, Fe2O3, MgO, CaO, Na2O, K2O, LILEs, HFSEs relative to background values obtained from sandstones and granitic rocks in the area. Baryte mineralization from Lessel-Mbagwa, Bunde and Ihugh is marked by positive Gd (17.1-21.4) and negative Eu (0.02-0.05) anomalies. Negative Ce anomaly (0.06) is evident in barytes from Lessel-Mbagwa and Bunde whereas baryte from Ihugh is characterized by positive Ce anomaly (1.3). The structurally controlled nature of the mineralization, depleted major and trace elements concentration in the barytes in addition to REE anomalies indicate that mixing of a strongly differentiated residual Ba-bearing fluid and sulphur-rich seawater occurred under low temperature and oxidizing-reducing conditions. The tectonic event which occurred during the Santonian to Early Campanian reactivated the NE-SW, NW-SE structural pathways in the basement gneiss and also created similar structures in the Turonian Lessel Sandstone.

  17. Evaluation of creative problem-solving abilities in undergraduate structural engineers through interdisciplinary problem-based learning

    Science.gov (United States)

    McCrum, Daniel Patrick

    2017-11-01

    For a structural engineer, effective communication and interaction with architects cannot be underestimated as a key skill to success throughout their professional career. Structural engineers and architects have to share a common language and understanding of each other in order to achieve the most desirable architectural and structural designs. This interaction and engagement develops during their professional career but needs to be nurtured during their undergraduate studies. The objective of this paper is to present the strategies employed to engage higher order thinking in structural engineering students in order to help them solve complex problem-based learning (PBL) design scenarios presented by architecture students. The strategies employed were applied in the experimental setting of an undergraduate module in structural engineering at Queen's University Belfast in the UK. The strategies employed were active learning to engage with content knowledge, the use of physical conceptual structural models to reinforce key concepts and finally, reinforcing the need for hand sketching of ideas to promote higher order problem-solving. The strategies employed were evaluated through student survey, student feedback and module facilitator (this author) reflection. The strategies were qualitatively perceived by the tutor and quantitatively evaluated by students in a cross-sectional study to help interaction with the architecture students, aid interdisciplinary learning and help students creatively solve problems (through higher order thinking). The students clearly enjoyed this module and in particular interacting with structural engineering tutors and students from another discipline.

  18. Structure and strategies in children's educational television: the roles of program type and learning strategies in children's learning.

    Science.gov (United States)

    Linebarger, Deborah L; Piotrowski, Jessica Taylor

    2010-01-01

    Educational TV has been consistently linked to children's learning. In this research, educational TV characteristics were identified, coded, and tested for their influence on children's program-specific comprehension and vocabulary outcomes. Study 1 details a content analysis of TV features including a program's macrostructure (i.e., narrative or expository) and learning strategies embedded in the macrostructure that support learning in print-based contexts. In Study 2, regression analyses were used to predict outcomes involving 71 second and third graders (average age=7.63 years). Strategies were categorized as organizing, rehearsing, elaborating, or affective in function. Outcomes were uniformly higher for narrative macrostructures. Strategies used in narratives predicted relatively homogenous relations across outcomes, whereas strategies in expositories predicted quite heterogeneous relations across outcomes. © 2010 The Authors. Child Development © 2010 Society for Research in Child Development, Inc.

  19. Effect of practical training on the learning motivation profile of Japanese pharmacy students using structural equation modeling

    Directory of Open Access Journals (Sweden)

    Shigeo Yamamura

    2017-02-01

    Full Text Available Purpose To establish a model of Japanese pharmacy students’ learning motivation profile and investigate the effects of pharmaceutical practical training programs on their learning motivation. Methods The Science Motivation Questionnaire II was administered to pharmacy students in their 4th (before practical training, 5th (before practical training at clinical sites, and 6th (after all practical training years of study at Josai International University in April, 2016. Factor analysis and multiple-group structural equation modeling were conducted for data analysis. Results A total of 165 students participated. The learning motivation profile was modeled with 4 factors (intrinsic, career, self-determination, and grade motivation, and the most effective learning motivation was grade motivation. In the multiple-group analysis, the fit of the model with the data was acceptable, and the estimated mean value of the factor of ‘self-determination’ in the learning motivation profile increased after the practical training programs (P= 0.048, Cohen’s d= 0.43. Conclusion Practical training programs in a 6-year course were effective for increasing learning motivation, based on ‘self-determination’ among Japanese pharmacy students. The results suggest that practical training programs are meaningful not only for providing clinical experience but also for raising learning motivation.

  20. Effect of practical training on the learning motivation profile of Japanese pharmacy students using structural equation modeling.

    Science.gov (United States)

    Yamamura, Shigeo; Takehira, Rieko

    2017-01-01

    To establish a model of Japanese pharmacy students' learning motivation profile and investigate the effects of pharmaceutical practical training programs on their learning motivation. The Science Motivation Questionnaire II was administered to pharmacy students in their 4th (before practical training), 5th (before practical training at clinical sites), and 6th (after all practical training) years of study at Josai International University in April, 2016. Factor analysis and multiple-group structural equation modeling were conducted for data analysis. A total of 165 students participated. The learning motivation profile was modeled with 4 factors (intrinsic, career, self-determination, and grade motivation), and the most effective learning motivation was grade motivation. In the multiple-group analysis, the fit of the model with the data was acceptable, and the estimated mean value of the factor of 'self-determination' in the learning motivation profile increased after the practical training programs (P= 0.048, Cohen's d = 0.43). Practical training programs in a 6-year course were effective for increasing learning motivation, based on 'self-determination' among Japanese pharmacy students. The results suggest that practical training programs are meaningful not only for providing clinical experience but also for raising learning motivation.